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Siniatchkin, M., W.-D. Gerber, P. Kropp, and A. Vein. "Contingent Negative Variation in Patients with Chronic Daily Headache." Cephalalgia 18, no. 8 (October 1998): 565–69. http://dx.doi.org/10.1046/j.1468-2982.1998.1808565.x.
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The aim of this study was the investigation of amplitude and habituation of contingent negative variation (CNV) in migraine and chronic daily headache (CDH) patients in order to describe possible neurophysiological features responsible for the clinical transformation and worsening of the headache. Fifteen females suffering from migraine without aura and 15 females diagnosed with CDH evolved from migraine without aura with interparoxysmal chronic tension-type headache (transformed migraine), underwent CNV recording. Fifteen healthy females matched for age served as controls. CNV was obtained from C3 and C4 using the standard reaction time paradigm and 3 sec ISI. The amplitudes and habituation of total CNV, early and late components, and of post-imperative negative variation (PINV) were calculated. The migraine patients were characterized by significantly more pronounced negativity of the early component and total CNV, compared to CDH sufferers and controls. CDH patients demonstrated significantly reduced negativity of the late component and pronounced PINV compared to the other groups. The early component of CNV did not habituate in migraine or CDH patients. However, the impaired habituation in CDH was related to significantly lower amplitudes. These results support the diagnostic and scientific value of habituation in migraine research and therapy. Late components of CNV and PINV can be considered as predictive variables for transformation of migraine. The results are discussed in terms of the relationship between late CNV, PINV, environment control abilities and susceptibility for development of depression.
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Hultin, L., P. Rossini, G. L. Romani, P. Högstedt, F. Tecchio, and V. Pizzella. "Neuromagnetic localization of the late component of the contingent negative variation." Electroencephalography and Clinical Neurophysiology 98, no. 6 (June 1996): 435–48. http://dx.doi.org/10.1016/0013-4694(96)95507-8.
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Blom, Jorian H. G., Caro H. Wiering, and Rob H. J. Van der Lubbe. "Distraction Reduces Both Early and Late Electrocutaneous Stimulus Evoked Potentials." Journal of Psychophysiology 26, no. 4 (January 1, 2012): 168–77. http://dx.doi.org/10.1027/0269-8803/a000079.
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Previous electroencephalography studies revealed mixed effects of sustained distraction on early negative and later positive event-related potential components evoked by electrocutaneous stimuli. In our study we further examined the influence of sustained distraction to clarify these discrepancies. Electrocutaneous stimuli of three intensities were delivered in pulse trains to the forearm either while participants attended the stimuli or while they performed a mental-arithmetic or a word-association distraction task. The amplitudes of the N1 and the late P2/P3a components were attenuated during both distraction tasks. These results seem to resolve the debate concerning the attentional modulation of the N1 component. Furthermore, we observed that the amplitude of the late P2/P3a component was strongly affected by stimulus change, in line with the opinion that this component is actually a P3a orienting response. Our study additionally revealed that habituation effects were reflected in lower intensity ratings and reduced amplitudes of the N1 and P3a components. The latter effects were independent of the type of task, which suggests that habituation is unaffected by attention.
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Karaman, Taha, Sibel Özkaynak, Korkut Yaltkaya, and Çetin Büyükberker. "Bereitschaftpotential in schizophrenia." British Journal of Psychiatry 171, no. 1 (July 1997): 31–34. http://dx.doi.org/10.1192/bjp.171.1.31.
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BackgroundSeveral reports have documented the presence of motor abnormalities in schizophrenic patients.MethodThirty schizophrenics and 28 healthy controls were included in the study. Scalp-recorded bereitschaftpotentials (BPs) generated prior to voluntary movements were recorded in all subjects.ResultsThe early (NSI) and late components of BP and peak negativity were reduced in all schizophrenic patients. In particular, the NSI was reduced in patients with positive symptoms, and the late component in patients with negative symptoms.ConclusionsThese findings provide further support for the involvement of frontal cortex, subcortical structures and their connections in schizophrenia, and highlight some differences between positive and negative symptom clusters.
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NOTARI, ALESSIO. "LATE TIME FAILURE OF FRIEDMANN EQUATION." Modern Physics Letters A 21, no. 40 (December 28, 2006): 2997–3007. http://dx.doi.org/10.1142/s0217732306021852.
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It is widely believed that the assumption of homogeneity is a good zeroth order approximation for the expansion of our Universe. We analyze the correction due to subhorizon inhomogeneous gravitational fields. While at early times this contribution (which may act as a negative pressure component) is perturbatively subdominant, we show that the perturbative series is likely to diverge at redshift of order 1, due to the growth of perturbations. So, the homogeneous Friedmann equation cannot be trusted at late times. We suggest that the puzzling observations of a present acceleration of the Universe, may just be due to the unjustified use of the Friedmann equation and not to the presence of a Dark Energy component. This would completely solve the coincidence problem.
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Melehin, A. I., and E. A. Sergienko. "Features of Social Cognition in Late Adulthood." Social Psychology and Society 6, no. 4 (2015): 60–77. http://dx.doi.org/10.17759/sps.2015060405.
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The paper presents outcomes of researches on the central component of social cognition — theory of mind in late adulthood. The outcomes show that, in normal aging, in advanced adulthood (55—74 years) as well as in old age (75—90 years) there are several qualitative changes in the affective (understanding and differentiation of emotions) and cognitive (understanding irony and deceit) components of theory of mind. Also, at these ages individuals may develop various forms of theory of mind deficits. They may encounter difficulties with reading facial expressions and recognizing other people’s emotions. It becomes harder for them to recognize negative emotions (such as sorrow, fear, anger) than positive ones (joy). The paper describes features of pragmatic interpretation of events and understanding of deceit and irony in late adulthood.
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Miller, B. A., and C. J. Woolf. "Glutamate-mediated slow synaptic currents in neonatal rat deep dorsal horn neurons in vitro." Journal of Neurophysiology 76, no. 3 (September 1, 1996): 1465–76. http://dx.doi.org/10.1152/jn.1996.76.3.1465.
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1. The role of glutamate in slow excitatory synaptic transmission between small-diameter primary afferents and deep dorsal horn neurons was examined in neonatal rat spinal cord in vitro with the use of the whole cell voltage-clamp technique. 2. Single-shock electrical stimulation of large-diameter A beta-fibers evoked a short-latency (< 10 ms) fast (< 500 ms) excitatory postsynaptic current (EPSC). Stimulation of small-diameter A delta- and C fibers resulted, in addition, in a slowly rising and decaying EPSC (lasting up to 14 s) following the fast EPSC. The slow EPSC was never observed with stimulation of A beta-fibers. 3. Two patterns of EPSCs were observed, "type 1" and "type 2," which differed in their time course (lasting up to 1 and 14 s, respectively). The type 1 response was biphasic, with a fast monosynaptic component followed by an invariant, presumably monosynaptic, late slow component. The type 2 response was multiphasic, with a fast monosynaptic component followed by a slow component composed of fast polysynaptic currents superimposed on a slow current. 4. The fast monosynaptic component had a linear conductance, whereas the late slower component of the A beta-fiber-evoked response had a negative slope conductance at holding potentials more negative than -23 mV. Both currents reversed at a membrane potential of -1.2 +/- 2.8 (SE) mV. 5. With the use of selective non-N-methyl-D-aspartate (non-NMDA) and NMDA receptor antagonists [6-cyano-7-nitroquinox-aline-2,3-dione (CNQX) or 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo (F) quinoxaline and D(-)-2-amino-5-phosphonopentanoic acid (D-AP5), respectively] we showed that both the early fast (A beta-fiber evoked) and the late slow (A delta- and C fiber evoked) components were mediated by non-NMDA and NMDA receptors. CNQX suppressed both the early fast and late slow components of the compound EPSC, whereas D-AP5 suppressed the polysynaptic currents of the early fast component and the late slow component without significantly affecting the early fast monosynaptic component. 6. Slow EPSCs summated on low-frequency (1 or 10 Hz), repetitive stimulation and produced long-duration "tail" currents on cessation of the stimulus. The amount of temporal summation was proportional to the duration of the slow EPSC and the frequency of stimulation. 7. Our results suggest that slow ionotropic-glutamate-receptor-mediated EPSCs produced by the stimulation of small-diameter primary afferents play an important role in activity-dependent synaptic plasticity in the dorsal horn.
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Sweden, B. Van, M. G. Van Erp, F. Mesotten, and M. Maes. "Frontal cortex reactivity differentiates between schizophrenic subtypes: auditory ERP-evidence." Acta Neuropsychiatrica 13, no. 3 (September 2001): 61–67. http://dx.doi.org/10.1017/s0924270800035249.
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SUMMARYObjectives: To extend the hypothesis that late auditory EP shifts represent pathophysiologcial markers in schizophrenia. Methods: Early negative (±100 μs) and late positive (>300 ms) auditory oddball and CNV responses are topographically compared in 3 medicated schizophrenic subtypes.Results: Only late cortical responses differentiate between paranoid, residual and disorganised schizophrenia. Core features of the deficit residual state encompass low-voltage N2P3 responses and missing central initial CNV components. Both paranoid and disorganised schizophrenics show a distinctive reactivity of the frontal cortex. Paranoid schizophrenia is characterized by an extensive frontal spread of the task-related P3 response. Disorganised schizophrenia shows a specifically increased frontal CNV component indicating a nonspecific arousal reaction.Conclusion: Combinations of late auditory EP-patterns fairly fit with the cognitive/behavioral status observed in schizophrenia spectrum disorders.
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Strobel, R. J., and J. A. Daubenspeck. "Early and late respiratory-related cortical potentials evoked by pressure pulse stimuli in humans." Journal of Applied Physiology 74, no. 4 (April 1, 1993): 1484–91. http://dx.doi.org/10.1152/jappl.1993.74.4.1484.
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Although respiratory-related cortical evoked potentials (CEPs) have been obtained in humans, early-latency responses have been obtained only with direct electrical stimulation of respiratory afferents. We have recorded both early and late cortical activity in response to a relatively novel stimulus consisting of a 300-ms negative pressure pulse applied to the mouth near the start of selected inspirations, when mouth pressure attained a predetermined threshold. This stimulus caused highly reproducible and rapid changes in mouth pressure and was effective in eliciting CEPs to a wide range of applied pressures. Using pulses of approximately -2 to -25 cmH2O, we obtained an early positive component with a mean latency of approximately 20 ms and a subsequent negative component at approximately 30 ms in normal subjects. Peak-to-peak amplitude varied directly, and component latencies inversely, as a function of pulse magnitude. Using -5- to -10-cmH2O stimuli, we also measured a later positive-negative-positive response with mean component latencies of 96.7 +/- 15.1, 147 +/- 14.8, and 237.6 +/- 23.5 ms, respectively. The early-latency activity was resistant to manipulations of stimulus predictability, whereas the later waves were attenuated or disappeared when load presentation was made completely predictable. We validated our method by eliminating the possibility of tactile stimulation of the lips and teeth as the origin of the evoked responses. We propose that early-latency activity derives from precortical structures and may provide a window on the functioning of respiratory afferents in normal subjects and in patients with respiratory disease.
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Hiraku, Shiho, and Haruo Sakuma. "Effects on Contingent Negative Variation of Set Created by Anticipating Variable Foreperiods." Perceptual and Motor Skills 83, no. 3_suppl (December 1996): 1163–69. http://dx.doi.org/10.2466/pms.1996.83.3f.1163.
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The influence of set on a simple reaction time task was examined by comparing the differences of psychological factors between a group of subjects who expected and experienced a fixed foreperiod (Control condition: 12 subjects) and another group of subjects who were instructed to expect variable foreperiods but experienced the same fixed foreperiod (Instruction condition: 11 subjects), using the index of contingent negative variation (CNV). The foreperiod of simple reaction time cask in each condition was fixed at 3 sec. Subjects were required to respond to 2 blocks of 24 trials, and each instruction was presented between blocks. On the second block CNV amplitudes were higher in the instruction condition as was every CNV component (early, late, and whole components). The set created by anticipating variable foreperiods seems to increase cerebral activity, arousal, and attention during simple reaction time tasks.
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Pilarczyk-Zurek, Magdalena, Grzegorz Majka, Beata Skowron, Agnieszka Baranowska, Monika Piwowar, and Magdalena Strus. "The Multi-Component Causes of Late Neonatal Sepsis—Can We Regulate Them?" Nutrients 14, no. 2 (January 7, 2022): 243. http://dx.doi.org/10.3390/nu14020243.
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Elucidating the mechanisms of bacterial translocation is crucial for the prevention and treatment of neonatal sepsis. In the present study, we aimed to evaluate the potential of lactoferrin to inhibit the development of late-onset blood infection in neonates. Our investigation evaluates the role of key stress factors leading to the translocation of intestinal bacteria into the bloodstream and, consequently, the development of life-threatening sepsis. Three stress factors, namely weaning, intraperitoneal administration of Gram-positive cocci and oral intake of Gram-negative rods, were found to act synergistically. We developed a novel model of rat pups sepsis induced by bacterial translocation and observed the inhibition of this process by supplementation of various forms of lactoferrin: iron-depleted (apolactoferrin), iron-saturated (hololactoferrin) and manganese-saturated lactoferrin. Additionally, lactoferrin saturated with manganese significantly increases the Lactobacillus bacterial population, which contributes to the fortification of the intestinal barrier and inhibits the translocation phenomenon. The acquired knowledge can be used to limit the development of sepsis in newborns in hospital neonatal intensive care units.
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Hiraku, Shiho, and Haeuo Sakuma. "The Psychological Factors of a Premature Response Based on Contingent Negative Variation." Perceptual and Motor Skills 83, no. 3 (December 1996): 1083–90. http://dx.doi.org/10.2466/pms.1996.83.3.1083.
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The psychological factors of a premature response on simple reaction-time tasks were examined by comparing the difference between control responses (33 samples) and premature responses (33 samples) using the index of Contingent Negative Variation (CNV). The first (warning) stimulus was a click, the second (imperative) stimulus was a colored circular figure presented on a CRT, and the interstimulus interval was set at 3 sec. 72 trials were administered to the 24 subjects, then 33 artifact-free CNV data in a premature response were shown. Analyses indicated that CNV amplitudes in the premature response were lower than those in the control response at frontal position. Especially in the premature response, CNV waveforms stayed around baseline toward S2 at F3 and F4. In the analyses of variance, every CNV component (early, late, and whole components) at F4 or Fz was significantly lower for the premature response. These results suggested that the optimal prediction, arousal, and attention do not seem to be maintained in a premature response.
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Mutisya, J. M., J. A. Sullivan, S. Couling, J. C. Sutton, and J. Zheng. "Leaf Scorch Epidemics Reduce Vegetative Growth and Fruit Yield of `Kent' Strawberry." HortScience 40, no. 1 (February 2005): 76–79. http://dx.doi.org/10.21273/hortsci.40.1.76.
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The relationship between severity of leaf scorch epidemics, caused by Diplocarpon earlianum, and components of vegetative growth and fruit yield was examined in `Kent' strawberry (Fragaria ×ananassa Duch.). Plants were treated in July with six densities of initial inoculum of the pathogen, and severity of leaf scorch was assessed at 2-week intervals from late July to late October. After an analysis of vegetative growth in late October, plants were overwintered in the field or grown in a greenhouse, and later assessed for yield components. Relationships between area under the disease progress curve (AUDPC) and plant growth and yield components were examined by regression analysis. Significant negative linear relationships were found between AUDPC values and number of green leaves, leaf area, leaf dry weight, crown number, crown dry mass, and root dry weight. Significant negative relationships were also found between AUDPC values and number of flowers and inflorescences, and total and marketable berries in the subsequent season, in plants maintained in the field or in the greenhouse. Mean berry weight was not significantly affected. Reduction in the number of crowns in plants affected by leaf scorch was a major factor limiting the yield of diseased plants. In an analysis of regrowth at seven weeks after fruit harvest, a significant negative linear relationships was found between AUDPC values and each growth component except crown dry weight. Collectively, the data provide a rationale to optimize timing of treatments, such as chemical fungicides or microbial agents, to control leaf scorch in August, September and October and thereby promote berry yield in the subsequent season.
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Knippenberg, J. M. J., E. L. J. M. van Luijtelaar, and J. H. R. Maes. "Slow Late Component in Conditioned Stimulus-Evoked Potentials From the Amygdala After Fear Conditioning in the Rat." Neural Plasticity 9, no. 4 (2002): 261–72. http://dx.doi.org/10.1155/np.2002.261.
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Male Wistar rats were subjected to a differential Pavlovian fear conditioning procedure in which one of two tones (6 or 10 kHz) was followed by an electric shock (CS+) and the other was not (CS-). Before and after fear conditioning, we recorded the evoked potentials elicited byCS+andCS-from electrodes aimed at the lateral nucleus of the amygdala. Before conditioning, a slow, negative component with peak amplitude around 150 ms was present in the evoked potentials. This component was sensitive to habituation. After fear conditioning, bothCS+andCS-elicited the same late component, albeit with a larger amplitude. This enhancement was temporary: decreasing amplitude was observed in the course of CS test presentations under extinction. Prior research revealed a comparable slow component in the amygdala of the cat under similar experimental conditions. The collective results indicate that the large late component in the amygdala is enhanced by fear conditioning, suggesting that such enhancement reflects the anticipation of a biologically significant event.
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Solada, Katharine E., Brendan T. Reilly, Joseph S. Stoner, Shanaka L. de Silva, Adonara E. Mucek, Robert G. Hatfield, Indyo Pratomo, Rendi Jamil, and Baskoro Setianto. "Paleomagnetic observations from lake sediments on Samosir Island, Toba caldera, Indonesia, and its late Pleistocene resurgence." Quaternary Research 95 (April 7, 2020): 97–112. http://dx.doi.org/10.1017/qua.2020.13.
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AbstractApproximately 74 ka, Toba caldera in Sumatra, Indonesia, erupted in one of the most catastrophic supereruptions in Earth's history. Resurgent uplift of the caldera floor raised Samosir Island 700 m above Lake Toba, exposing valuable lake sediments. To constrain sediment chronology, we collected 173 discrete paleomagnetic 8 cm3 cubes and 15 radiocarbon samples from six sections across the island. Bulk organic 14C ages provide an initial chronostratigraphic framework ranging from ~12 to 46 ka. Natural and laboratory magnetizations were studied using alternating field demagnetization. A generally well-defined primary magnetization is isolated using principal component analysis. Comparison of inclination, and to a lesser degree declination, across independently dated sections suggests paleomagnetic secular variation (PSV) is recorded. Average inclination of −6° is more negative than a geocentric axial dipole would predict, but consistent with an eastward extension of the negative inclination anomaly observed in the western equatorial Pacific. The 14C- and PSV-derived age model constrains resurgent uplift, confirming faster uplift rates to the east and slower rates to the west, while suggesting that fault blocks moved differentially from each other within a generally trapdoor-type configuration.
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Ruchsow, Martin, Georg Grön, Kathleen Reuter, Manfred Spitzer, Leopold Hermle, and Markus Kiefer. "Error-Related Brain Activity in Patients with Obsessive- Compulsive Disorder and in Healthy Controls." Journal of Psychophysiology 19, no. 4 (January 2005): 298–304. http://dx.doi.org/10.1027/0269-8803.19.4.298.
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Abstract: Obsessive-compulsive disorder (OCD) has been related to a hyperactive frontal-striatal-thalamic circuit and associated with altered mechanisms of action and error monitoring. In the present study, we examined whether these results only hold for errors in choice reaction time experiments and Stroop tasks or extend to errors of commission in a Go/NoGo task, as well. We investigated the electrophysiological correlates of error monitoring in 11 patients with OCD and 11 age-, sex-, and education-matched healthy controls using event-related potentials (ERPs). Participants performed a Go/NoGo task while a 64-channel EEG was recorded. Our study focused on three ERP components: the error-related negativity (ERN)/error negativity (Ne), the “early” error positivity (“early” Pe) reflecting automatic error processing, and the “late” error positivity (“late” Pe), which is thought to mirror the awareness of erroneous responses. Artifact-free EEG-segments were used to compute ERPs on correct Go trials and incorrect NoGo trials (i.e., errors of commission), separately. Patients with OCD showed enhanced (more negative) ERN/Ne amplitudes compared to control subjects. Groups did not differ with regard to the early Pe component and the late Pe component. Our results support the view that compulsivity in OCD patients is related to hyper-functioning error monitoring processes.
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Kropp, Peter, and Wolf-Dieter Gerber. "Is Increased Amplitude of Contingent Negative Variation in Migraine Due to Cortical Hyperactivity or to Reduced Habituation?" Cephalalgia 13, no. 1 (February 1993): 37–41. http://dx.doi.org/10.1046/j.1468-2982.1993.1301037.x.
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The aim of this study was to compare the habituation kinetics of contingent negative variation (CNV) between 12 migraineurs without aura and matched healthy controls. CNV was studied with a 3 sec interval between the warning stimulus (WS) and the imperative stimulus (IS). The data from (a) the total interval (WS-IS), (b) early component, and (c) late component were analyzed. During successive trials the habituation kinetics were determined using regression analysis. On CNV averaged over 32 trials, migraine patients had a significantly higher negativity in the total interval compared to controls. When sequential blocks of four trials were analyzed, the most significant finding in migraineurs was lack of habituation of the early CNV component. The present study indicates that a delayed habituation, rather than a general increased cortical activity, is responsible for the CNV abnormalities in migraine without aura. We suggest that migraineurs between attacks not only have a cortical hyperexcitability, but also a lack of cortical inhibition causing delayed habituation.
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Maury, René C., Henriette Lapierre, Delphine Bosch, Jean Marcoux, Leopold Krystyn, Joseph Cotten, François Bussy, Pierre Brunet, and François Senebier. "The alkaline intraplate volcanism of the Antalya nappes (Turkey): a Late Triassic remnant of the Neotethys." Bulletin de la Société Géologique de France 179, no. 4 (July 1, 2008): 397–410. http://dx.doi.org/10.2113/gssgfbull.179.4.397.
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AbstractLate Triassic submarine alkali basalts and hawaiites were collected from two superimposed tectonic slices belonging to the Kara Dere – Sayrun unit of the Middle Antalya nappes, southwestern Turkey. New determinations on conodont faunas allow to date this sequence to the Lower Carnian (Julian). The volcanic rocks show rather homogeneous compositions, with high TiO2 and relatively low MgO and Ni contents which suggest olivine fractionation. Their primitive mantle-normalised multi-elements plots show Nb and Ta enrichments relative to La, Pb negative anomalies and heavy rare earth element and Y depletions typical of intraplate ocean island basalts. These characteristics are consistent with the major and trace element compositions of their primary clinopyroxene phenocrysts, which do not show any feature ascribable to crustal contamination. The studied lavas display a restricted range of εNd (+4.6 to +5.2) which falls within the range of ocean island basalts. Their initial (143Nd/144Nd)i ratios are too low to be explained by a simple mixing line between depleted MORB mantle (DMM) and HIMU components. Their Pb and Nd isotopic compositions plot along a mixing line between HIMU component and an enriched mantle, the composition of which could be the result of the addition of about 5 to 8% of an EM2 component (recycled marine sediments) to DMM. The lack of evidence for any continental crustal component in their genesis could be consistent with their emplacement in an intra-oceanic setting.
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Ashton, H., J. F. Golding, V. R. Marsh, J. W. Thompson, F. Hassanyeh, and S. P. Tyrer. "Cortical evoked potentials and clinical rating scales as measures of depressive illness." Psychological Medicine 18, no. 2 (May 1988): 305–17. http://dx.doi.org/10.1017/s0033291700007856.
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SynopsisRelationships between clinical ratings and cortical evoked potentials were examined before and during antidepressant drug treatment in 32 patients with major depressive disorder (DSM-III). Clinical rating scales included Hamilton Rating Scale for Depression, Beck Depression Inventory, Present State Examination (PSE) and Newcastle Scale. Evoked potentials included contingent negative variation (CNV), post-imperative negative variation (PINV) and auditory evoked potential (AEP) There were close correlations between all rating scales, and factor analysis produced only one component, suggesting that the common variance between them related to severity of depression. CNV magnitude before treatment correlated negatively with severity of depression regardless of diagnostic category. Depressed patients had a prominent PINV which persisted during antidepressant treatment. The amplitude of late components (N1P2) of the AEP was reduced strikingly in patients with a history of suicide attempts.
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McLendon, Molly K., Birgit Schilling, Jason R. Hunt, Michael A. Apicella, and Bradford W. Gibson. "Identification of LpxL, a Late Acyltransferase of Francisella tularensis." Infection and Immunity 75, no. 11 (August 27, 2007): 5518–31. http://dx.doi.org/10.1128/iai.01288-06.
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ABSTRACT Lipopolysaccharide (LPS) is a major component of the outer membrane of gram-negative bacteria, and the lipid A region of LPS mediates stimulation of the immune system in a structure-dependent manner. Unlike the LPS of many other gram-negative bacteria, the LPS of Francisella tularensis isolated from in vitro cultures is not proinflammatory. This observed lack of proinflammatory prowess may reflect structural features of the lipid A, such as the number and length of the acyl chains and the single-phosphate group. To better understand this phenotype, we have begun to elucidate LPS biosynthesis in F. tularensis. We present complementation, mutational, and chemical data demonstrating that F. tularensis FTT0232c encodes a functional late acyltransferase enzyme with specificity similar to that of the Escherichia coli LpxL ortholog. Expression of this late acyltransferase complemented the temperature-sensitive and hypoacylated lipid A phenotypes of an E. coli lpxL mutant, expression of FTT0232c is increased during intracellular growth relative to that during in vitro growth, and finally, LPS obtained from a mutant of F. tularensis lacking FTT0232c showed an abundant triacyl lipid A species after mass spectrometric analysis, consistent with the loss of an LpxL late acyltransferase.
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Kropp, P., and W.-D. Gerber. "Contingent Negative Variation During Migraine Attack and Interval: Evidence for Normalization of Slow Cortical Potentials During the Attack." Cephalalgia 15, no. 2 (April 1995): 123–28. http://dx.doi.org/10.1046/j.1468-2982.1995.015002123.x.
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The contingent negative variation (CNV) amplitudes of 16 subjects with migraine without aura were studied during pain-free intervals and during attacks and the results were compared with those of 22 healthy subjects. In 32 trials the CNV amplitudes were calculated for (a) “total interval”, (b) “early CNV component”, (c) “late CNV component”, and (d) habituation. There was a significantly higher total CNV amplitude in migraine subjects during pain-free intervals compared to that of the healthy subjects and migraine patients during an attack. Healthy subjects as well as subjects studied during the attack showed a significant habituation whereas migraine subjects studied during pain-free intervals did not. This suggests that the higher CNV amplitude in migraine patients studied between pain-free attacks may be due in part to impaired habituation.
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Sartory, G., V. Gillessen, K. H. Grotemeyer, and T. Elbert. "The Contingent Magnetic Variation in Migraine." Journal of Psychophysiology 13, no. 4 (October 1999): 215–23. http://dx.doi.org/10.1027//0269-8803.13.4.215.
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Abstract Migraine is characterized by an increased contingent negative variation. Separate comparisons of the early and late component showed that it was the former rather than the latter that was elevated. The function and localization of the early component are as yet poorly understood. The magneto-encephalogram was recorded in 16 patients with migraine and 17 healthy control subjects during a forewarned reaction time task. Neuromagnetic data were recorded with a 37-channel neuromagnetometer with the sensors being placed above the left hemisphere contralaterally to the side of the acoustic stimulation and the motor reaction. Subjects responded to the second of two low intensity sound stimuli that were administered with an interval of 4.5 s. Migraine patients exhibited a significantly higher amplitude of the early component of the contingent magnetic variation (CMV) than controls. Groups did not differ with regard to the amplitude of the late component. Modeling the sources with a single moving equivalent current dipole (ECD) provided a high goodness of fit for the M100 (magnetic N1) in both groups and for the early component of the CMV in migraineurs but not controls. The activity of the early component was centered medially with respect to the M100-ECDs and more laterally so in migraine patients than in controls.
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Honoré, E., M. M. Adamantidis, B. A. Dupuis, C. E. Challice, and P. Guilbault. "Calcium channels and excitation–contraction coupling in cardiac cells. II. A pharmacological study of the biphasic contraction in guinea-pig papillary muscle." Canadian Journal of Physiology and Pharmacology 65, no. 9 (September 1, 1987): 1832–39. http://dx.doi.org/10.1139/y87-285.
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Biphasic contractions were obtained in guinea-pig papillary muscle by inducing partial depolarization in K+-rich solution (17 mM) in the presence of 0.3 μM isoproterenol. Mn2+ ions inhibited the two components of contraction in a similar way. Nifedipine and particularly Cd2+ ions specifically inhibited the second component of contraction. Isoproterenol and BAY K 8644 markedly increased the amplitude of the second component (P2) of contraction. Nevertheless, a moderate positive inotropic effect of isoproterenol was found on the first component (P1) of contraction when excitability was restored by 0.2 mM Ba instead of isoproterenol. Acetylcholine and hypoxia decreased the amplitude of the second component of contraction to a greater extent. In the presence of digoxin or Na+-free solution, P1was strongly increased. When sarcoplasmic reticular function was hindered by 1 mM caffeine or in the presence of Ca2+-free Sr2+ solution, digoxin always induced a negative inotropic effect on P2. Inversely in these conditions the transient positive inotropic effect of Na+-free solution was strongly reduced. These results are consistent with the hypothesis that the late component of contraction is triggered by the slow inward Ca2+ current and that the early component is due to Ca2+ release from the sarcoplasmic reticulum.
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Jiang, Yue. "Neural correlates of pride and joy recognition in early childhood." Social Behavior and Personality: an international journal 49, no. 9 (September 1, 2021): 1–13. http://dx.doi.org/10.2224/sbp.10329.
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I investigated neural processing during the recognition of pride and joy in early childhood using the event-related potential (ERP) technique. Electroencephalography recording was taken of 21 children aged between 4 and 6 years. They were shown photographs of familiar peers and strangers whose facial expressions displayed the emotion of either pride or joy. ERPs were recorded for the children's judgment of the expression of these two emotions when an image was presented. The results demonstrate that the neural dynamics during children's recognition of pride and joy involve three stages: The early negative component is spontaneously responsive to familiar faces, the midlatency negative central component is responsive to expression of familiar faces, and the late positive component marks greater extended processing of an expression of pride. These findings provide new insight into the neural mechanism of pride and joy recognition in children aged 4 to 6 years.
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Pavlova, Nadezhda S., and Yelena A. Sergiyenko. "LIFE QUALITY AND TIME PERSPECTIVE AT THE LATE ONTOGENESIS STAGE." Vestnik Kostroma State University. Series: Pedagogy. Psychology. Sociokinetics, no. 2 (2020): 47–55. http://dx.doi.org/10.34216/2073-1426-2020-26-2-47-55.
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The article deals with the peculiarities of psychological and physical health components as the life quality indicators in correlation with the time perspective at the late ontogenesis stage (aged 58–93) in groups of people leading different lifestyles: elderly non-working people who are at home-based social services; elderly non-working people, leading an active lifestyle. It has been established that subjective indicators of life quality is at the rather low level and decreases with age. An active lifestyle, as well as cohabitation living, contributes to keep higher life quality. The prevailing temporal orientations in the general sample are «Future» and «Positive Past». A balanced time perspective is observed in one third of respondents. The Past and the Present are correlated, while the mode of the future is isolated. Active pensioners are more future-oriented then the older people at social services. The age of 64–75 years is the most balanced, when all three aspects of time are actualised and integrated in the personality time perspective. Single or cohabiting living does not affect the personality time perspective. The life quality is correlated with the time perspective: the factors «Hedonistic present», «Fatalistic present» and «Negative past» are mainly related to the psychological component of health and its parameters.
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Vélez-Uribe, Idaly, and Mónica Rosselli. "Electrophysiological correlates of emotion word processing in Spanish–English bilinguals." Bilingualism: Language and Cognition 24, no. 1 (July 21, 2020): 31–55. http://dx.doi.org/10.1017/s136672892000036x.
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AbstractWe examined how proficiency influences the processing of emotion words in Spanish–English bilinguals (22 balanced and 20 unbalanced). All unbalanced bilinguals were more proficient in English than Spanish. Participants rated the valence of negative, neutral, and positive words in both languages while EEG was being recorded. ERP latencies and amplitudes were analyzed for two components. The language effect was significant on the late positive component (LPC) amplitude, which was larger for emotion than for neutral words for both groups in English. The unbalanced group presented larger LPC amplitudes for positive than for neutral and for neutral than for negative words in Spanish, suggesting emotion processing differences in these participants’ less proficient language. Valence effects were consistent across languages for the balanced group, but not for the unbalanced group, perhaps reflecting differences in reactivity to emotion words in the less proficient language.
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Herzog, W. R., N. R. Ferreri, W. Ptak, and P. W. Askenase. "The DTH-initiating Thy-1+ cell is double-negative (CD4-, CD8-) and CD3-, and expresses IL-3 receptors, but no IL-2 receptors." Journal of Immunology 143, no. 10 (November 15, 1989): 3125–33. http://dx.doi.org/10.4049/jimmunol.143.10.3125.
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Abstract The elicitation of delayed-type hypersensitivity (DTH) requires an early-acting Thy-1+ cell that produces an Ag-specific, non-MHC-restricted factor that initiates DTH by sensitizing the local tissue for release of the vasoactive amine serotonin. We characterized the phenotype of this DTH-initiating cell by treating cells from sensitized mice with different antibodies and then either with rabbit C or anti-Ig panning or bead separation to deplete various subpopulations. We then transferred these cells i.v. into naive recipients that were challenged to elicit DTH. Our findings indicate that the early DTH-initiating cell is Thy-1+, Lyt-1+, CD4-, CD8- and CD3-, whereas the classical, late DTH effector T cell is Thy-1+, Lyt-1+, CD4+, CD8-, and CD3+. We hypothesize that DTH-initiating cells are primitive T cells with Ag receptors that can bind Ag without MHC-restriction. This hypothesis was supported by the finding that two different antibodies, that both bind T cell-derived Ag-binding molecules, eliminated the DTH-initiating, cell but did not affect the late component, MHC-restricted CD4+, CD3+ T cell. Additional experiments with antibodies against restricted determinants of the T-200 glycoprotein family (CD45R) showed that the early but not the late cell is positive for B220, which is usually present on B cells, and on some activated T cells. Also, the DTH-initiating cell is Il-2R-, but Il-3R+; whereas the late component DTH T cell is IL-2R+ and IL-3-. Our findings suggest that DTH-initiating cells may be Ag-specific lymphoid precursor cells that arise before final differentiation along the pathway leading to mature T or B cells. Our results indicate that antigen-specific Thy-1+, CD3-, CD4-, CD8- cells function in vivo to initiate DTH reactions.
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Guaragnella, Cataldo, Maria Rizzi, and Agostino Giorgio. "Marginal Component Analysis of ECG Signals for Beat-to-Beat Detection of Ventricular Late Potentials." Electronics 8, no. 9 (September 6, 2019): 1000. http://dx.doi.org/10.3390/electronics8091000.
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Heart condition diagnosis based on electrocardiogram signal analysis is the basic method used in prevention of cardiovascular diseases, which are recognized as the leading cause of death globally. To anticipate the occurrence of ventricular arrhythmia, the detection of Ventricular Late Potentials (VLPs) is clinically worthwhile. VLPs are low-amplitude and high-frequency signals appearing at the end part of QRS complexes in the electrocardiogram, which can be considered as a robust feature for arrhythmia risk stratification in patients with cardiac diseases. This paper proposes a beat-to-beat VLP detection method based on the the marginal component analysis and investigates its performance taking into account different ratios between QRS and VLP power. After a denoising phase, performed adopting the singular vector decomposition technique, heartbeats characterized by VLP onsets are identified and extracted taking into account the vector magnitude of each high resolution ECG (HR-ECG) record. To evaluate the proposed method performance, a 15-lead HR-ECG database consisting of real VLP-negative and simulated VLP-positive patterns was used. The achieved results highlight the method validity for VLP detection.
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La Fortune, Kristin, Dahua Zhang, Gordana Raca, and Erik A. Ranheim. "A Unique “Composite” PTLD with Diffuse Large B-Cell and T/Anaplastic Large Cell Lymphoma Components Occurring 17 Years after Transplant." Case Reports in Hematology 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/386147.
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Posttransplant lymphoproliferative disorder (PTLD) comprises a spectrum ranging from polyclonal hyperplasia to aggressive monoclonal lymphomas. The majority of PTLDs are of B-cell origin while T-cell PTLDs and Hodgkin lymphoma-like PTLDs are uncommon. Here, we report a unique case of a 56-year-old man in whom a lymphoma with two distinct components developed as a duodenal mass seventeen years following a combined kidney-pancreas transplant. This PTLD, which has features not previously reported in the literature, consisted of one component of CD20 positive and EBV negative monomorphic diffuse large B-cell lymphoma. The other component showed anaplastic morphology, expressed some but not all T-cell markers, failed to express most B-cell markers except for PAX5, and was diffusely EBV positive. Possible etiologies for this peculiar constellation of findings are discussed and the literature reviewed for “composite-like” lymphomas late in the posttransplant setting.
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Oddy, Bruce W., Robert J. Barry, Stuart J. Johnstone, and Adam R. Clarke. "Removal of CNV Effects from the N2 and P3 ERP Components in a Visual Go/NoGo Task." Journal of Psychophysiology 19, no. 1 (January 2005): 24–34. http://dx.doi.org/10.1027/0269-8803.19.1.24.
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Abstract. In an S1-S2 Go/NoGo task the impact of slow potentials following S1, particularly the late component of the contingent negative variation (CNV), on the following cognitive-processing waveforms to S2 (e.g., N2 and P3) remains unclear. A common method to correct for these confounding slow waves has used a forced baseline shortly before S2. The impact of this on ERP measures relating to S2 is unclear. An earlier method of CNV correction, devised to remove its effect on P3 measures by using different baselines for each condition, appears questionable. This study explored the removal of the CNV from both Go and NoGo waveforms to clarify the sensory and cognitive components elicited by S2. Principal Component Analysis (PCA) was performed on the ERP means, and a component relating to the CNV was subtracted from each subject's raw data for each site and condition. Results showed that this effectively removed the CNV without distortion of the S2 ERP morphology. This technique may prove useful in the analysis of the N2 and P3 as indicators of processes involved in response inhibition.
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Schindler, Sebastian, Maximilian Bruchmann, Claudia Krasowski, Robert Moeck, and Thomas Straube. "Charged With a Crime: The Neuronal Signature of Processing Negatively Evaluated Faces Under Different Attentional Conditions." Psychological Science 32, no. 8 (July 23, 2021): 1311–24. http://dx.doi.org/10.1177/0956797621996667.
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Our brains rapidly respond to human faces and can differentiate between many identities, retrieving rich semantic emotional-knowledge information. Studies provide a mixed picture of how such information affects event-related potentials (ERPs). We systematically examined the effect of feature-based attention on ERP modulations to briefly presented faces of individuals associated with a crime. The tasks required participants ( N = 40 adults) to discriminate the orientation of lines overlaid onto the face, the age of the face, or emotional information associated with the face. Negative faces amplified the N170 ERP component during all tasks, whereas the early posterior negativity (EPN) and late positive potential (LPP) components were increased only when the emotional information was attended to. These findings suggest that during early configural analyses (N170), evaluative information potentiates face processing regardless of feature-based attention. During intermediate, only partially resource-dependent, processing stages (EPN) and late stages of elaborate stimulus processing (LPP), attention to the acquired emotional information is necessary for amplified processing of negatively evaluated faces.
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Zhou, Yangen, Jiamei Lu, Xiaochen Tang, Chaoyi Hu, and Haibin Wang. "Modulation of forgiveness on processing hurt situations: A study of event-related potentials." Social Behavior and Personality: an international journal 46, no. 4 (April 5, 2018): 607–16. http://dx.doi.org/10.2224/sbp.6635.
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To explore the neuro-mechanism of the time course of processing a hurt situation, we analyzed event-related potentials (ERPs) generated in the brain in response to stimuli in individuals with different degrees of forgiveness. Participants were 216 university students. Of the early ERP components, the negative-deflecting N1 was modulated neither by degree of forgiveness nor by the hurt situation, and the positive-deflecting P2 was larger for low-forgiveness than for high-forgiveness participants, and for low-hurt than for high-hurt situations. The N2, which identifies and encodes stimulus, was enhanced in the high-forgiveness group and for high-hurt situations. Importantly, the late positive component (LPC) stage of stimulus evaluation was larger in the high-forgiveness group for high-hurt situations, but in the low-forgiveness group was evident for low-hurt situations. These data indicate that the modulation of forgiveness on processing hurt situations occurs at the late stage of information processing.
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Andreasen, M., and J. J. Hablitz. "Kinetic properties of a transient outward current in rat neocortical neurons." Journal of Neurophysiology 68, no. 4 (October 1, 1992): 1133–42. http://dx.doi.org/10.1152/jn.1992.68.4.1133.
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1. Whole-cell patch-clamp techniques were used to record outward currents in embryonic rat neocortical neurons maintained in culture. In the presence of tetrodotoxin and cadmium, depolarization evoked an outward current with a complex waveform. This outward current consisted of an initial fast transient component and a late, slowly inactivating component. 2. The two outward current components could be separated pharmacologically with the use of tetraethylammonium (TEA) and 4-aminopyridine (4-AP). TEA (20 mM) applied extracellularly completely blocked the late component, unmasking a fast transient outward current (TOC). 4-AP (5 mM) applied extracellularly blocked the early component while reducing the late component by 27.8 +/- 9.7% (mean +/- SE). 3. The TOC activated after a short delay and rose rapidly to a peak. The time to peak was voltage dependent and decreased with depolarization. In the presence of 200 microM extracellular cadmium, activation threshold was around -25 mV, and current amplitude increased with depolarization. The voltage-conductance relationship was well fitted by the use of the Boltzmann equation with a Vm of +19 mV for half activation and a slope factor of +6 mV. 4. On sustained depolarization the TOC rapidly inactivated and decayed to baseline within 500-600 ms. The decay phase followed a single exponential time course with a time constant of 55-65 ms. The decay time was most rapid at potentials from +5 to +20 mV and increased slightly with further depolarization. 5. Steady-state inactivation of the TOC, in the presence of cadmium, was complete near -10 mV and was totally relieved at potentials more negative than -75 mV. With the use of the Boltzmann equation, a Vm of -34 mV for half inactivation and a slope factor of -8.6 mV were found. 6. Recovery of the TOC from steady-state inactivation followed a single exponential time course and was voltage dependent. When the membrane potential was held at -84 mV during the conditioning pulse, the time constant of recovery was 17 ms, increasing to 45.2 and 58.1 ms at holding potentials of -64 and -44 mV, respectively. Holding at potentials more negative than -84 mV produced no further change in the recovery time course. 7. The presence of 200 microM external cadmium altered the TOC activation and inactivation curves. Removal of cadmium produced a -16-mV shift in the Vm for half activation and a -25-mV shift in the inactivation curve. This sensitivity to cadmium is higher than that reported in other systems.(ABSTRACT TRUNCATED AT 400 WORDS)
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Krasowski, Claudia, Sebastian Schindler, Maximilian Bruchmann, Robert Moeck, and Thomas Straube. "Electrophysiological responses to negative evaluative person-knowledge: Effects of individual differences." Cognitive, Affective, & Behavioral Neuroscience 21, no. 4 (April 13, 2021): 822–36. http://dx.doi.org/10.3758/s13415-021-00894-w.
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AbstractFaces transmit rich information about a unique personal identity. Recent studies examined how negative evaluative information affects event-related potentials (ERPs), the relevance of individual differences, such as trait anxiety, neuroticism, or agreeableness, for these effects is unclear. In this preregistered study, participants (N = 80) were presented with neutral faces, either associated with highly negative or neutral biographical information. Faces were shown under three different task conditions that varied the attentional focus on face-unrelated features, perceptual face information, or emotional information. Results showed a task-independent increase of the N170 component for faces associated with negative information, while interactions occurred for the Early Posterior Negativity (EPN) and the Late Positive Potential (LPP), showing ERP differences only when paying attention to the evaluative information. Trait anxiety and neuroticism did not influence ERP differences. Low agreeableness increased EPN differences during perceptual distraction. Thus, we observed that low agreeableness leads to early increased processing of potentially hostile faces, although participants were required to attend to a face-unrelated feature.
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Chang, Yu-Ling, Yi-Yuan Zhuo, and Di-Hua Luo. "Education Moderates the Negative Effect of Apolipoprotein E ɛ4 on Response Inhibition in Older Adults." Journal of Alzheimer's Disease 82, no. 3 (August 3, 2021): 1147–57. http://dx.doi.org/10.3233/jad-210183.
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Background: Studies have reported that apolipoprotein E epsilon 4 (APOE ɛ4) has adverse effects on executive functions (EFs) in late adulthood. However, the results have been inconsistent. Insufficient measurements of executive functioning, uncontrolled clinical and demographic confounders, and moderation effects from other environmental factors are suspected to account for the inconsistency. Objective: This study used aggregate measures to examine the effects of APOE ɛ4 on four components of EFs, namely switching, working memory, inhibition, and reasoning. We further investigated whether high educational attainment, a proxy measure for cognitive reserve, moderates the adverse effects of ɛ4 on EFs. Methods: Cognitively unimpaired older participants were divided into groups based on APOE genotype and into subgroups based on educational attainment level. The demographic and clinical variables were matched between the groups. Four core components of the EFs were measured using a relatively comprehensive battery. Results: The results revealed that although no main effect of the APOE genotype was observed across the four EF components, the potentially adverse effects of ɛ4 on inhibition were alleviated by high educational attainment. A main effect of education on the reasoning component was also observed. The moderation analysis revealed that for older adults with 12 years of education or fewer, the relationship between the APOE ɛ4 genotype and inhibition performance became increasingly negative. Conclusion: This study highlights the distinctive role of response inhibition in the gene–environment interaction and underlines the importance of considering factors of both nature and nurture to understand the complex process of cognitive aging.
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Fallah, Mehdi, Mousa Rasouli, Darab Hassani, Shaneka S. Lawson, Saadat Sarikhani, and Kourosh Vahdati. "Tracing Superior Late-Leafing Genotypes of Persian Walnut for Managing Late-Spring Frost in Walnut Orchards." Horticulturae 8, no. 11 (October 28, 2022): 1003. http://dx.doi.org/10.3390/horticulturae8111003.
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Evaluating genetic diversity in walnut (Juglans regia L.) populations is a rapid approach used by walnut breeding programs to distinguish superior genotypes. The present study was conducted on the walnut population of Hamedan Province, one of the richest and most genetically diverse regions in Iran, during 2018–2019. After the initial screening, 47 genotypes were selected for further evaluation of pomological and phenological traits based on International Plant Genetic Resources Institute (IPGRI) descriptors. Nut and kernel weights among the selected genotypes ranged from 7.15 to 21.05 g and 3.0 to 10.8 g, respectively. Principal component analysis (PCA) categorized the genotypes into three distinct groups. Whereas the cluster analysis (CA) revealed the similarities and dissimilarities among the genotypes by identifying four major clusters. Spearman correlation analysis showed a positive correlation (p < 0.01) between nut weight (NWT), nut size, and kernel weight (KW), while a negative correlation (p < 0.01) between shell thickness (STH) and packing tissue thickness (PTT) with kernel percentage (KP) was observed. Lastly, 10 of 47 genotypes (TAL8, TAL9, TAL10, TAL14, TAL19, TAL22, TB2, TB4, TB6, and RDGH5) were considered superior. Superior genotypes were late-leafing (25–40 days after the standard) and displayed a lateral bearing (LB) habit with heavy nuts (12.52–16.82 g) and kernels (6.53–8.15 g), thin shells (1.06–1.25 mm), and lightly colored kernels.
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Gong, Xianmin, Helene H. Fung, Ginger Qinghong Zeng, and Chun-Yu Tse. "Cultural Relevance Reduces the Enhanced Neural Processing of Positively Valenced Information in Older Adults." Journals of Gerontology: Series B 75, no. 10 (May 20, 2019): 2075–85. http://dx.doi.org/10.1093/geronb/gbz049.
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Abstract Objectives This study investigated (a) whether the age-related enhancement in processing positive relative to negative emotional information happened at the early and/or late processing stages and (b) if the age-related positivity effect was modulated by cultural relevance using event-related brain potential (ERP). Methods Seventeen younger and 19 older Chinese adults judged the emotional valence of Chinese and Western pictures while electroencephalogram (EEG) was recorded and analyzed by temporospatial principal component analysis to dissociate the processing stages. Results (a) Larger N100 for negative than positive pictures was observed in younger, but not older adults, while older but not younger adults showed larger late anterior P300 for positive than negative pictures. (b) Older adults showed larger early posterior P300 for positive than negative Western pictures, but not culturally relevant Chinese pictures; such modulation effect by cultural relevance was absent in younger adults. Discussion These findings suggest an age-related decrease in sensitivity to negative information in the earlier stage and an age-related increase in sensitivity to positive information in the later stage of cognitive processing. This supports a dual-route model of the age-related positivity effect. Moreover, the age-related positivity effect is more evident for stimuli with less cultural relevance.
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Jagla, K., M. Frasch, T. Jagla, G. Dretzen, F. Bellard, and M. Bellard. "ladybird, a new component of the cardiogenic pathway in Drosophila required for diversification of heart precursors." Development 124, no. 18 (September 15, 1997): 3471–79. http://dx.doi.org/10.1242/dev.124.18.3471.
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The embryonic heart precursors of Drosophila are arranged in a repeated pattern of segmental units. There is growing evidence that the development of individual elements of this pattern depends on both mesoderm intrinsic patterning information and inductive signals from the ectoderm. In this study, we demonstrate that two homeobox genes, ladybird early and ladybird late, are involved in the cardiogenic pathway in Drosophila. Their expression is specific to a subset of cardioblast and pericardial cell precursors and is critically dependent on mesodermal tinman function, epidermal Wingless signaling and the coordinate action of neurogenic genes. Negative regulation by hedgehog is required to restrict ladybird expression to two out of six cardioblasts in each hemisegment. Overexpression of ladybird causes a hyperplasia of heart precursors and alters the identity of even-skipped-positive pericardial cells. Loss of ladybird function leads to the opposite transformation, suggesting that ladybird participates in the determination of heart lineages and is required to specify the identities of subpopulations of heart cells. We find that both early Wingless signaling and ladybird-dependent late Wingless signaling are required for proper heart formation. Thus, we propose that ladybird plays a dual role in cardiogenesis: (i) during the early phase, it is involved in specification of a segmental subset of heart precursors as a component of the cardiogenic tinman-cascade and (ii) during the late phase, it is needed for maintaining wingless activity and thereby sustaining the heart pattern process. These events result in a diversification of heart cell identities within each segment.
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Siniatchkin, M., W.-D. Gerber, P. Kropp, T. Voznesenskaya, and AM Vein. "Are the Periodic Changes of Neurophysiological Parameters During the Pain-Free Interval in Migraine Related to Abnormal Orienting Activity?" Cephalalgia 20, no. 1 (February 2000): 20–29. http://dx.doi.org/10.1046/j.1468-2982.2000.00002.x.
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Objective and methods Migraine patients are characterized by increased amplitude and reduced habituation of contingent negative variation (CNV). Furthermore, the CNV underlies periodic changes during the pain-free interval, being maximal before attack. The periodicity of CNV is related to periodic changes in habituation, probably due to variation of orienting activity during the pain-free interval. CNV and orienting response (OR) were studied in 20 females suffering from migraine without aura and in 12 matched healthy females. The neurophysiological recordings in the group of patients were performed 1–4 days before and 4 days after a migraine attack. The amplitudes and habituation of early and late components and total CNV were calculated. The OR was assessed using the habituation of the skin conductance response (SCR) and alpha blocking (AB). The non-parametric tests were employed for statistical analysis. Results There were no differences between the two groups for habituation of all CNV components and of SCR following an attack. However, the habituation of AB was significantly reduced in migraine. Before attack we observed a significantly reduced habituation of the early and total CNV and of the AB compared to controls and recordings performed after an attack. The habituation of the late component and of SCR remained unchanged. Conclusions The abnormal habituation could be explained by the periodic changes of physiological parameters during the pain-free interval. The impaired habituation of early CNV in migraine is associated with increased orienting activity seen only in the central component (AB) of OR.
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Richards, David R., Robert F. Butler, and Tekla A. Harms. "Paleomagnetism of the late Paleozoic Slide Mountain terrane, northern and central British Columbia." Canadian Journal of Earth Sciences 30, no. 9 (September 1, 1993): 1898–913. http://dx.doi.org/10.1139/e93-168.
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Paleomagnetic samples were collected from Mid-Pennsylvanian to Lower Permian red argillaceous cherts at two localities of the Slide Mountain terrane: 18 sites from the Sylvester allochthon in northern British Columbia and 11 sites from Sliding Mountain in central British Columbia. A secondary component of natural remanent magnetization in the Sylvester samples yields a paleomagnetic pole that can be brought into coincidence with the Jurassic portion of the North American apparent polar wander path by inferring vertical-axis rotation during obduction of the allochthon. Both localities yield a characteristic component (ChRM) with unblocking temperatures from 650 to 680 °C. After structural correction for bedding tilt, all inclinations of ChRM are negative, consistent with magnetization during a reversed-polarity interval in the northern hemisphere. Site-mean ChRM directions show consistent inclinations but distinct stratigraphic groupings of declinations. Inclination-only statistics indicate that the ChRM passes a tilt test within the Sylvester allochthon and regionally between the two localities. The ChRM was apparently acquired prior to structural imbrication within the Sylvester section and regional differential tilting. We interpret the ChRM to be a primary magnetization acquired at or soon after deposition during the Permo-Carboniferous reversed-polarity superchron. The mean ChRM inclination of −16.7° ± 6.0° from the Sylvester allochthon indicates a paleo-latitude of 8.8° ± 3.4°N, which is corroborated by a paleolatitude of 1.9° ± 1.5°N from the Sliding Mountain locality. When compared with expected Pennsylvanian–Permian paleolatitudes, a net poleward translation of 20.3 ± 3.7° is implied for at least the sampled lithotectonic component of the Sylvester allochthon.
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Smith, Kelsey M., Jeffrey W. Britton, and Gregory D. Cascino. "Late-onset Lennox-Gastaut syndrome." Neurology: Clinical Practice 8, no. 5 (September 28, 2018): 397–402. http://dx.doi.org/10.1212/cpj.0000000000000527.
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BackgroundWe describe the clinical features and outcome in patients with late-onset Lennox-Gastaut syndrome (LGS).MethodsAdult patients evaluated between January 1, 2000, and March 1, 2017, who presented with onset of LGS ≥10 years were identified. Data abstracted included age at seizure onset, seizure types, etiology, treatments, EEG and neuroimaging results, cerebrospinal fluid (CSF) findings, and autoimmune evaluation.ResultsTen patients (8 females) were identified. The mean age at onset of seizures consistent with LGS was 16.5 years (range, 10–32 years). Seizure types included tonic, atonic, and tonic-clonic seizures (all), myoclonic seizures (n = 3), and atypical absence seizures (n = 7). Five patients had normal intellectual function at onset. Prolonged video-EEG monitoring recorded seizures and generalized interictal epileptiform discharges in all. All patients had drug-resistant epilepsy (range of antiseizure drugs tried, 7–16). Two patients had a history of intrathecal methotrexate to treat acute lymphoblastic leukemia. Two patients had malformations of cortical development. CSF analysis (n = 5) showed a mild elevation in the protein level without other abnormalities. Autoantibody determinations in the serum (n = 4) or the CSF (n = 5) and genetic testing (n = 5) were negative. At final follow-up, all but 1 patient was disabled and required a caregiver, and none were driving. One patient died of probable sudden unexpected death in epilepsy (SUDEP).ConclusionsLate-onset LGS represents a rare, treatment-resistant generalized epilepsy that is disabling and may be associated with progressive cognitive impairment. The elevated CSF protein level in our cohort could have been due to high seizure burden but increases the possibility of an inflammatory component to the pathophysiology of this disorder.
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Seymour, Dave J., Michelle Carson, Jean-Baptiste Daniel, Victoria Sanz, Javier Martín-Tereso, and John Doelman. "231 Effect of fat-embedded calcium gluconate on lactation performance in high-yielding multiparous dairy cows in a commercial dairy setting." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 146–47. http://dx.doi.org/10.1093/jas/skaa278.267.
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Abstract Fat-embedded calcium gluconate fed as a dietary supplement has previously been shown to increase milk and component yields in lactating dairy cattle in controlled experimental settings. These responses are thought to be due to improvements in gut barrier function and health driven by increased butyrate supply from the fermentation of calcium gluconate in the hindgut. The objectives of the current study were to validate the effects of a fat-embedded calcium gluconate supplement offered during late gestation and early lactation on milk production and milk component yields in a commercial setting. From April to December 2019, 151 multiparous Holstein-Friesian dairy cows were assigned to one of four treatment sequences in a randomized complete block design within a 2 x 2 factorial design (negative control or supplement prepartum, and negative control or supplement postpartum). Outcomes pertaining to milk production, component yields and health parameters were recorded for the first 100 days of lactation. Yields of milk and all components increased (P ≤ 0.045) in response to postpartum supplementation, in agreement with previous studies. Milk protein content was 0.03% lower (P = 0.003) in animals receiving the supplement prepartum. Additionally, prepartum supplementation diminished the lactation performance response relative to animals receiving supplementation in the postpartum period only; lactation performance was partially ameliorated by subsequent postpartum supplementation. Overall, these results support previous work examining the lactation performance response to fat-embedded calcium gluconate supplementation in dairy cattle. Future controlled studies examining the effects of prepartum supplementation on subsequent lactation performance are warranted.
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Chapman, C. Andrew, and Ronald J. Racine. "Converging Inputs to the Entorhinal Cortex From the Piriform Cortex and Medial Septum: Facilitation and Current Source Density Analysis." Journal of Neurophysiology 78, no. 5 (November 1, 1997): 2602–15. http://dx.doi.org/10.1152/jn.1997.78.5.2602.
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Chapman, C. Andrew and Ronald J. Racine. Converging inputs to the entorhinal cortex from the piriform cortex and medial septum: facilitation and current source density analysis. J. Neurophysiol. 78: 2602–2615, 1997. The entorhinal cortex receives sensory inputs from the piriform cortex and modulatory inputs from the medial septum. To examine short-term synaptic facilitation effects in these pathways, current source density (CSD) analysis was used first to localize the entorhinal cortex membrane currents, which generate field potentials evoked by stimulation of these afferents. Field potentials were recorded at 50-μm intervals through the medial entorhinal cortex in urethan-anesthetized rats and the one-dimensional CSD was calculated. Piriform cortex stimulation evoked a surface-negative, deep-positive field potential component in the entorhinal cortex with mean onset and peak latencies of 10.4 and 18.4 ms. The component followed brief 100-Hz stimulation, consistent with a monosynaptic response. CSD analysis linked the component to a current sink, which often began in layer I before peaking in layer II. A later, surface-positive field potential component peaked at latencies near 45 ms and was associated with a current source in layer II. Medial septal stimulation evoked positive and negative field potential components which peaked at latencies near 7 and 16 ms, respectively. A weaker and more prolonged surface-negative, deep-positive component peaked at latencies near 25 ms. The early components were generated by currents in the hippocampal formation, and the late surface-negative component was generated by currents in layers II to IV of the entorhinal cortex. Short-term facilitation effects in conscious animals were examined using electrodes chronically implanted near layer II of the entorhinal cortex. Paired-pulse stimulation of the piriform cortex at interpulse intervals of 30 and 40 ms caused the largest facilitation (248%) of responses evoked by the second pulse. Responses evoked by medial septal stimulation also were facilitated maximally (59%) by a piriform cortex conditioning pulse delivered 30–40 ms earlier. Paired pulse stimulation of the medial septum caused the largest facilitation (149%) at intervals of 70 ms, but piriform cortex evoked responses were facilitated maximally (46%) by a septal conditioning pulse 100–200 ms earlier. Frequency potentiation effects were maximal during 12- to 18-Hz stimulation of either the piriform cortex or medial septum. Occlusion tests suggested that piriform cortex and medial septal efferents activate the same neurons. The CSD analysis results show that evoked field potential methods can be used effectively in chronically prepared animals to examine synaptic responses in the converging inputs from the piriform cortex and medial septum to the entorhinal cortex. The short-term potentiation phenomena observed here suggest that low-frequency activity in these pathways during endogenous oscillatory states may enhance entorhinal cortex responsivity to olfactory inputs.
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Masaki, Hiroaki, Noriyoshi Takasawa, and Katuo Yamazaki. "Human Movement-Related Brain Potentials Preceding Voluntary Movements in Different Arousal States Monitored with Skin Potential Level." Perceptual and Motor Skills 90, no. 1 (February 2000): 299–306. http://dx.doi.org/10.2466/pms.2000.90.1.299.
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The present study investigated the readiness potential (RP) preceding a brisk extension of the right middle finger during different arousal states as monitored by skin potential level (SPL). The late component of the readiness potential in the medium arousal state was significantly larger than those in the low and high arousal states. This finding indicates that the RP waveform may vary as a function of arousal stares suggesting the inverse U-shaped relationship proposed in studies of the contingent negative variation.
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Vallet, William, Antoine Hone-Blanchet, and Jerome Brunelin. "Abnormalities of the late positive potential during emotional processing in individuals with psychopathic traits: a meta-analysis." Psychological Medicine 50, no. 12 (September 3, 2019): 2085–95. http://dx.doi.org/10.1017/s0033291719002216.
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AbstractBackgroundIndividuals with psychopathic traits display deficits in emotional processing. A key event-related potential component involved in emotional processing is the late positive potential (LPP). In healthy controls, LPP amplitude is greater in response to negative stimuli than to positive or neutral stimuli. In the current study, we aimed to compare LPP amplitudes between individuals with psychopathic traits and control subjects when presented with negative, positive or neutral stimuli. We hypothesized that LPP amplitude evoked by emotional stimuli would be reduced in individuals with psychopathic traits compared to healthy controls.MethodsAfter a systematic review of the literature, we conducted a meta-analysis to compare LPP amplitude elicited by emotional stimuli in individuals with psychopathic traits and healthy controls.ResultsIndividuals with psychopathic traits showed significantly reduced LPP amplitude evoked by negative stimuli (mean effect size = −0.47; 95% CI −0.60 to −0.33; p < 0.005) compared to healthy controls. No significant differences between groups were observed for the processing of positive (mean effect size = −0.15; 95% CI −0.42 to 0.12; p = 0.28) and neutral stimuli (mean effect size = −0.12; 95% CI 0.31 to 0.07; p = 0.21).ConclusionsMeasured by LPP amplitude, individuals with psychopathic traits displayed abnormalities in the processing of emotional stimuli with negative valence whereas processing of stimuli with positive and neutral valence was unchanged as compared with healthy controls.
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Ramos Buarque, Silvana, and David Salas y Melia. "Link between the North Atlantic Oscillation and the surface mass balance components of the Greenland Ice Sheet under preindustrial and last interglacial climates: a study with a coupled global circulation model." Climate of the Past 14, no. 11 (November 12, 2018): 1707–25. http://dx.doi.org/10.5194/cp-14-1707-2018.
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Abstract. The relationship between the surface mass balance (SMB) components (accumulation and melting) of the Greenland Ice Sheet (GrIS) and the North Atlantic Oscillation (NAO) is examined from numerical simulations performed with a new atmospheric stretched grid configuration of the Centre National de Recherches Météorologiques Coupled Model (CNRM-CM) version 5.2 under three periods: preindustrial climate, a warm phase (early Eemian, 130 ka BP) and a cool phase (late Eemian, 115 ka BP) of the last interglacial. The horizontal grid of the atmospheric component of CNRM-CM5.2 is stretched from the tilted pole on Baffin Bay (72∘ N, 65∘ W) in order to obtain a higher spatial resolution on Greenland. The correlation between simulated SMB anomalies averaged over Greenland and the NAO index is weak in winter and significant in summer (about 0.6 for the three periods). In summer, spatial correlations between the NAO index and SMB components display different patterns from one period to another. These differences are analyzed in terms of the respective influence of the positive and negative phases of the NAO on accumulation and melting. Accumulation in south Greenland is significantly correlated with the positive (negative) phase of the NAO in a warm (cold) climate. Under preindustrial and 115 ka BP climates, melting along the margins is more correlated with the positive phase of the NAO than with its negative phase, whereas at 130 ka BP it is more correlated with the negative phase of the NAO in north and northeast Greenland.
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Tobimatsu, Shozo. "Visual Gnosis and Face Perception." International Journal of Computational Models and Algorithms in Medicine 3, no. 4 (October 2012): 11–20. http://dx.doi.org/10.4018/ijcmam.2012100102.
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There are two major parallel pathways in humans: the parvocellular (P) and magnocellular (M) pathways. The former has excellent spatial resolution with color selectivity, while the latter shows excellent temporal resolution with high contrast sensitivity. Visual stimuli should be tailored to answer specific clinical and/or research questions. This chapter examines the neural mechanisms of face perception using event-related potentials (ERPs). Face stimuli of different spatial frequencies were used to investigate how low-spatial-frequency (LSF) and high-spatial-frequency (HSF) components of the face contribute to the identification and recognition of the face and facial expressions. The P100 component in the occipital area (Oz), the N170 in the posterior temporal region (T5/T6) and late components peaking at 270-390 ms (T5/T6) were analyzed. LSF enhanced P100, while N170 was augmented by HSF irrespective of facial expressions. This suggested that LSF is important for global processing of facial expressions, whereas HSF handles featural processing. There were significant amplitude differences between positive and negative LSF facial expressions in the early time windows of 270-310 ms. Subsequently, the amplitudes among negative HSF facial expressions differed significantly in the later time windows of 330–390 ms. Discrimination between positive and negative facial expressions precedes discrimination among different negative expressions in a sequential manner based on parallel visual channels. Interestingly, patients with schizophrenia showed decreased spatial frequency sensitivities for face processing. Taken together, the spatially filtered face images are useful for exploring face perception and recognition.
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Cacioppo, John T., Stephen L. Crites, Gary G. Berntson, and Michael G. H. Coles. "If Attitudes Affect How Stimuli Are Processed, Should They Not Affect the Event-Related Brain Potential?" Psychological Science 4, no. 2 (March 1993): 108–12. http://dx.doi.org/10.1111/j.1467-9280.1993.tb00470.x.
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In Experiment 1, subjects completed an attitude survey to identify items toward which they held positive and negative attitudes. Subsequently, subjects were instructed to count the number of positive (or negative) stimuli in a series. Each series contained six attitude stimuli from a given semantic category (e.g., fruits), and the structure of the series was varied so that positive and negative stimuli, as indexed by subjects' idiosyncratic attitudes, were evaluatively consistent or inconsistent within the series. In Experiment 2, subjects were exposed to personality traits that were positive or negative in series of six. Again, the structure of the series was varied so that positive and negative traits were evaluatively consistent or inconsistent within the series. Results of Experiments 1 and 2 indicated that although the event-related brain potential did not differ as a function of stimulus valence per se, evaluatively inconsistent, in contrast to consistent, stimuli evoked a larger amplitude late P300-like positive component that was maximal over the centroparietal region.
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Petten, Cyma Van, Marta Kutas, Robert Kluender, Mark Mitchiner, and Heather McIsaac. "Fractionating the Word Repetition Effect with Event-Related Potentials." Journal of Cognitive Neuroscience 3, no. 2 (April 1991): 131–50. http://dx.doi.org/10.1162/jocn.1991.3.2.131.
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Word repetition has been a staple paradigm for both psycholinguistic and memory research; several possible loci for changes in behavioral performance have been proposed. These proposals are discussed in light of the event-related brain potential (ERP) data reported here. ERPs were recorded as subjects read nonfiction articles drawn from a popular magazine. The effects of word repetition were examined in this relatively natural context wherein words were repeated as a consequence of normal discourse structure. Three distinct components of the ERP were found to be sensitive to repetition: a positive component peaking at 200 msec poststimulus, a negative one at 400 msec (N400), and a later positivity. The components were differentially sensitive to the temporal lag between repetitions, the number of repetitions, and the normative frequency of the eliciting word. The N400 responded similarly to repetition in text as it has in experimental lists of words, but the late positivity showed a different pattern of results than in list studies.
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Li, Dengao, Junmin Zhao, Hongyan Liu, and Defeng Hao. "The Application of FastICA Combined with Related Function in Blind Signal Separation." Mathematical Problems in Engineering 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/953745.
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Blind source separation (BSS) has applications in the fields of data compression, feature recognition, speech, audio, and biosignal processing. Identification of ECG signal is one of the challenges in the biosignal processing. Proposed in this paper is a new method, which is the combination of related function relevance to estimated signal and negative entropy in fast independent component analysis (FastICA) as objective function, and the iterative formula is derived without any assumptions; then the independent components are found by maximizing the objective function. The improved algorithm shorthand for R-FastICA is applied to extract random mixed signals and ventricular late potential (VLP) signal from normal ECG signal; simultaneously the performance of R-FastICA algorithm is compared with traditional FastICA through simulation. Experimental results show that R-FastICA algorithm outperforms traditional FastICA with higher similarity coefficient and separation precision.