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Williams, Sandy IV. "Nigga Is Historical: This Is Not An Invitation For White People To Say Nigga." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/5926.
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Over the past several years I have been on a quest to locate a world beyond the one I’ve been presented. I am interested in the history of atomic particles - like everything that radiates off of a monument (both literally and those things that are metaphorically reified) - invisible things, and the ways in which these things insect beyond our knowledge systems. This inquiry takes many forms. Mine is a conceptually based practice linked to record keeping and time, and the ways in which these concepts find plurality within our culture; or more pointedly, the importance that we attach to “time” and “the record”, as they relate to our “legacies”, “cultures”, or “the canon”; our histories and the ahistorical, the prehistorical, fantasies, the things that never happened but could’ve, imagined futures and parallel universes.
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Nichols, Jason Anthony. "The realest nigga constructions of Black masculinity within rap music /." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3921.
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Thesis (M.A.) -- University of Maryland, College Park, 2006.Thesis research directed by: Dept. of American Studies. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Bell, Adrian Shane. "The “Nigger Trinity”: Engaging the Discourse in Post Civil Rights/Post 1960s America." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc103290/.
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The cultural and popular media landscape of the United States of America changed after the Civil-Rights movement of the 1960s. The word “Nigger” was changed during that same period of American history. There are several authors and a comic that helped change this word during the 1960s. The post Civil-Rights American has a different experience and understanding with this word than those born before 1970. This work triangulates the current cultural location of the word “Nigger,” “nigga,” and “the n-word” using linguistics, law, and two media case studies. The “Nigger” trinity is a model that adds value to the discourse that surrounds this one word in post civil-rights/post 1960s America.
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Logan, Nneka. "Uncovering the Range of Intentions and Interpretations Associated with N-Word Usage in American Film." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/communication_theses/12.
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Uncovering the Range of Intentions and Interpretations Associated with N-Word Usage in American Film by Nneka Logan Under the Direction of Michael Bruner ABSTRACT This thesis is an analysis of contemporary N-word usage. Key points are that there is more than one N-word in circulation, and that “nigger,” the racial slur, is only one conception of the N-word. A second point is that “nigga” is a separate word with a separate scope of meaning. I also argue that usage of “nigga” is a complex communicative phenomenon that cannot be essentialized in terms of race, socioeconomic status and other social factors. I argue that contemporary N-word usage is not an exclusively black cultural endeavor, but in fact a multiracial phenomenon. To support my assertions I employ communication, race and N-word scholarship, and I apply the scholarship to the text of American film. A study of this kind is significant because increasing numbers of people are being exposed to the N-words in a variety of contexts, but many are unaware of their important semantic differences. INDEX WORDS: Nigger, Nigga, N-word, Race, Interracial Communication, Hip Hop, Pop Culture
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OTTAVIANI, CECILIA. "Pinus nigra subsp. nigra in Appennino centrale: rimboschimenti e rinaturalizzazione." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245260.
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Pinus nigra subsp. nigra è stato ampiamente e diffusamente utilizzato per le opere di rimboschimento in tutta Europa, principalmente per frenare il dissesto idrogeologico di zone degradate e soggette ad intensa erosione per cause naturali ed antropiche. E’ stato spesso utilizzato per tali opere anche al di fuori del suo areale di distribuzione, come in Appennino centrale, dove non è presente come specie autoctona ma dove i rimboschimenti di Pinus nigra subsp. nigra sono realtà molto diffuse, per lo più non gestite e soggette ai naturali processi dinamici di recupero da parte della vegetazione autoctona. Tali comunità forestali ospitano spesso specie vegetali rare o di interesse biogeografico e a partire da queste si sta osservando la diffusione e colonizzazione per via gamica di Pinus nigra subsp. nigra, che si spinge fin sopra il limite attuale del bosco. Tale fenomeno testimonia come si stia assistendo ad un processo di rinaturalizzazione di questa specie a partire da centri di diffusione dei semi costituiti principalmente dai rimboschimenti artificiali. Scopo della presente ricerca era lo studio floristico-vegetazionale, sinecologico, sindinamico, biogeografico e sintassonomico delle comunità vegetali di Pinus nigra subsp. nigra presenti lungo l’Appennino centrale di origine antropica (rimboschimenti vecchi di epoca d’impianto precedente il 1950) e di quelle naturali dove Pinus nigra subsp. nigra si inserisce e che ne rappresentano l’aspetto di rinaturalizzazione. Per i rimboschimenti inoltre gli obbiettivi erano: i) l’analisi delle dinamiche in atto e dello stato di rinaturalizzazione; ii) valutare l’autonomia floristico-vegetazionale legata agli effetti della prolungata presenza di Pinus nigra subsp. nigra sulla diversità floristica attraverso il confronto con i boschi autoctoni limitrofi; iii) verificare eventuali analogie e differenze floristico vegetazionali e biogeografiche tra le pinete di origine antropica individuate e le pinete naturali di Pinus nigra subsp. nigra descritte in letteratura per la penisola italiana e territori limitrofi.
Lo studio è stato condotto in Italia lungo la porzione centrale della dorsale appenninica e preappenninica dal Mt. Carpegna (PU) a nord a Villetta Barrea (AQ) a sud a quote comprese tra circa 600 m s.l.m. e 1700 m s.l.m. I risultati della presente ricerca hanno consentito di determinare che lo stato di rinaturalizzazione dei rimboschimenti è in funzione del bosco autoctono e quindi del sito di riferimento. Si sottolinea l’importanza dell’utilizzo dei boschi limitrofi come controllo per la valutazione dello stato di rinaturalizzazione dei rimboschimenti che in base ai risultati ottenuti risulta essere sito-specifica. Per i rimboschimenti di Pinus nigra subsp. nigra presenti in Appennino centrale dal termotipo mesotemperato superiore al supratemperato superiore il presente studio ha permesso di individuare l’autonomia floristica significativa di queste cenosi rispetto ai boschi autoctoni che si sviluppano nelle medesime condizioni ecologiche e costituisce un primo contributo per la loro caratterizzazione sintassonomica, per le quali vengono proposte due associazioni nell’ambito della classe Querco- Fagetea. L’autonomia riscontrata può essere interpretata come la risultante degli effetti legati alla prolungata presenza del pino sulla diversità specifica. Il confronto di queste cenosi con i dati di letteratura relativi alle pinete naturali a Pinus nigra subp. nigra descritte per l’Italia e i territori limitrofi ha evidenziato la separazione delle cenosi considerate appartenenti alle diverse classi sintassonomiche e il legame biogeografico tra le cenosi forestali appenniniche e quelle balcaniche espresse dall’alleanza Carpinion orientalis. I rimboschimenti di Pinus nigra subsp. nigra indagati con il presente studio possono essere considerati stadi durevoli di una successione dinamica che devia dalla naturale successione vegetazionale e ciò deve essere tenuto fortemente in considerazione anche per la programmazione degli interventi gestionali nell’ambito della Restoration ecology. Infine lo studio fitosociologico condotto sulle comunità caratterizzate dalla presenza di Pinus nigra subsp. nigra di origine gamica in Appennino centrale, ha permesso di evidenziare l’ambito vegetazionale più favorevole alla colonizzazione di Pinus nigra subsp. nigra, rappresentato dalle comunità edafoxerofile pioniere e durevoli della classe Junipero-Pinetea. Per le cenosi di Juniperus communis subsp. nana, J. communis subsp. hemisphaerica e Pinus nigra subsp. nigra si propone la nuova alleanza Sorbo ariae-Juniperion nanae che concorre a completare il quadro sintassonomico della classe Junipero-Pinetea per l’Appennino centro-meridionale.Pinus nigra subsp. nigra was used widely and extensively for reforestation activities in Europe, mainly to curb the hydrogeological instability of degraded areas that had been subjected to intense erosion because of natural and human causes. It often was used even outside its distribution area, as in the central Apennines, where it is not a native species, but where the Pinus nigra subsp. nigra reforestation areas are widespread. They are most unmanaged and subjected to the natural dynamic processes of the native vegetation. These forest communities often host rare plants or species of biogeographical interest and from these we are observing the Pinus nigra subsp. nigra gamic colonization, that goes far above the current treeline. This phenomenon shows how we are attending a re-naturalization process of this species starting from the seeds distribution centers of artificial reforestation areas. The purpose of this research was the floristic-vegetational, sinecologic, sindinamic, biogeographic and syntaxonomic study of the Pinus nigra subsp. nigra anthropic communities belonging to the central Apennines (old reforestation areas implanted before 1950) and of natural communities where gamic Pinus nigra subsp. nigra is present and which represent its re-naturalization. For the reforestation areas the objectives were also: i) to analyse the dynamics involved and the restoration state; ii) to evaluate the floristic-vegetation autonomy linked to the effects of the prolonged Pinus nigra subsp. nigra presence on floristic diversity through comparison with adjacent native woods; iii) to examine floristic-vegetational and biogeographical similarities and differences between the anthropic Pinus nigra subsp. nigra forests identified and the natural pine forests described in the literature for the Italian Peninsula and adjacent territories. The study was carried out in Italy along the central portion of the Apennines from the Mt. Carpegna (PU) to Villetta Barrea (AQ) at altitude between 600 m a.s.l. and 1700 m a.s.l. The results of this research determined that the status of the restoration is a function of the native woods, and thus is a function of the reference site. We emphasize the importance of using the adjacent woods as a control for the restoration evaluation that appears to be site-specific. For Pinus nigra subsp. nigra reforestation areas found in the central Apennines, from the mesotemperate to upper supratemperate thermotype, this study identified the significant floristic autonomy of these plant communities compared to the native woods that grows under the same ecological conditions. These represents an initial contribution for their syntaxonomic characterization. We proposed two new associations included in the Querco-Fagetea class. The autonomy observed can be interpreted as the result of the effects of the prolonged pine presence on species diversity. The comparison between these plant communities with the natural Pinus nigra subsp. nigra forests described for Italy and the adjacent territories highlighted the separation of plant communities considered which belong to different syntaxonomic classes and it highlighted the biogeographic link between Apennine forest ecosystems and the Balkan ones expressed by the Carpinion orientalis alliance. The investigated Pinus nigra subsp. nigra reforestation areas can be considered durable stages of a dynamic that deviates from the natural vegetation succession, and this concept must be strongly consider for the planning of future silvicultural actions within the Restoration ecology. Finally, the phytosociological study on communities characterized by the presence of gamic Pinus nigra subsp. nigra in central Apennines highlighted the more favorable vegetation habitat for the Pinus nigra subsp. nigra colonization, that are represented by the edaphoxerophilous pioneer and durable communities of Junipero-Pinetea class. For the Juniperus communis subsp. nana, J. communis subsp. hemisphaerica and Pinus nigra subsp. nigra plant communities is proposed the new alliance Sorbo ariae-Juniperion nanae that contributes to complete the syntaxonomic Junipero-Pinetea class context for the central-southern Apennines.
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Guarenti, Isabelle Maffei. "Microscopia eletrônica da Tinea Nigra." Universidade Catolica de Pelotas, 2013. http://tede.ucpel.edu.br:8080/jspui/handle/tede/288.
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Previous issue date: 2013-07-22Tinea nigra is a rare superficial mycosis caused by Hortaea werneckii. This infection presents as asymptomatic brown to black macule mostly in palmo-plantar regions. This study presents dermatoscopy examination of a lesion, which demonstrated a homogeneous nonmelanocytic pigmented pattern with spicules in the macula; scanning electron microscopy (SEM) examination of the fungal culture, showing sympodial conidiogenesis; and SEM examination of a sample of the lesion, that revealed the epidermis with keratinocytes, elimination of fungal filaments and important aggregation of hyphae. SEM s findings correlated with those of dermatoscopic examination and allowed also documenting the mode of dissemination of tinea nigra, showing how hyphae are eliminated on lesion s surface
Tinea nigra é uma rara micose superficial causada pelo fungo Hortaea werneckii. Esta infecção apresenta-se como mancha assintomática acastanhada ou enegrecida, mais frequentemente na região palmo-plantar. Foram realizados neste estudo: dermatoscopia de uma lesão, a qual demonstrou um padrão homogêneo de pigmentação nãomelanocítica com espículas na mácula; microscopia eletrônica de varredura (MEV) da cultura fúngica, mostrando conidiogênese simpodial; e MEV de uma amostra da lesão, a qual revelou epiderme com queratinócitos, eliminação de filamentos fúngicos e importante agregação de hifas. Os achados de MEV se correlacionaram com aqueles do exame dermatoscópico e ainda permitiram documentar o modo de disseminação da tinea nigra, demonstrando como as hifas são eliminadas na superfície da lesão
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Boyes, Justin. "The microcircuitry of the substantia nigra." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408818.
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Bossy, Brigitte. "Ballota nigra : revue bibliographique et perspectives." Montpellier 1, 1993. http://www.theses.fr/1993MON11090.
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Micheletta, Jerome. "Social communication in crested macaques (Macaca nigra)." Thesis, University of Portsmouth, 2012. https://researchportal.port.ac.uk/portal/en/theses/social-communication-in-crested-macaques-macaca-nigra(e4908e72-7425-464f-bfec-9af968d81f97).html.
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Comparative research into animal communication has been and continues to be highly informative regarding the general principles underlying the evolution of communication (including human communication). However, our tendency to focus on specific modes of production of these signals (i.e. facial expressions, gestures or vocalisations) in isolation of each other, and in a limited number of species, may be obstructing our progress. Therefore, in this thesis, I adopted a novel and more comprehensive approach to a highly understudied primate, the crested macaques (Macaca nigra). First, I consider the effects of the strength of social bonds and dominance relationships between individuals (and, when possible, their kin relationships) when investigating the function of communicative signals. The findings show that communication can be flexible depending on social factors, possibly reflecting functional relevance to the context. Social bonds in particular, influenced communication between individuals facing immediate socio-ecological challenges (finding food and deterring predators). Second, I address the significance of multimodal communication in this species. I test the influence of the composition of communicative signals on the outcome of social interactions. The results show that subtle changes in the composition of communicative signals (multicomponent and multimodal) can have a profound effect on the outcome of social interactions. The findings resulting from this work constitute one of the first quantitative accounts of the communication system of crested macaques, thereby adding to the pool of data available to study communication from a comparative perspective. The comprehensive approach adopted in this thesis provides much needed insight into the importance of considering communication as multimodal and highly intertwined with species’ social style. Such an approach seems highly productive and provides insight into aspects of social and communicative complexity that have been overlooked so far.
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Al, Kafri Yaser. "Metals uptake in pine needles (Pinus nigra)." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-84446.
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Fan, Xiu-Di. "Substantia nigra dopamine infusion, behavioral and biochemical correlates." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ32783.pdf.
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This, Patrice. "Caractérisation et développement de marqueurs moléculaires en vue de l'analyse de lignées d'addition : Brassica napus-Brassica nigra et Diplotaxis erucoides-Brassica Nigra." Perpignan, 1992. http://www.theses.fr/1992PERP0166.
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Brassica nigra (2n=16) ou moutarde noire est une espece apparentee au colza (brassica napus). B. Nigra presente des caracteres agronomiques interessants qui pourront etre transferes au colza par croisements interspecifiques ou genie genetique. Dans le but d'analyser le genome de b. Nigra, des lignees d'addition ont ete construites. Il s'agit de plantes de b. Napus ou d. Erucoides qui portent en addition un chromosome ou une paire de chromosomes de b. Nigra. Les techniques cytologiques ne permettent pas de distinguer les chromosomes de b. Nigra les uns des autres. L'analyse moleculaire des lignees d'addition a ete effectuee en vue de l'identification des 8 lignees d'addition possibles. Pour ce faire, nous avons utilise les techniques d'analyse du polymorphisme enzymatique et de type rflp. Nous avons egalement mis au point et applique une nouvelle technique d'analyse du polymorphisme appelee rapd. Cent cinquante six marqueurs ont ete identifiees sur sept lignees b. Napus-b. Nigra et 31 sur sept lignees d. Erucoides-b. Nigra. Les marqueurs nous ont egalement permis d'identifier des lignees portant des chromosomes deletes et d'identifier des fragments du genome de b. Nigra introgresses dans le genome de b. Napus
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Peleckytė, Urtė. "Homeopatiškai paruošti preparatai iš Juglans nigra L. kevalo: biologiškai aktyvių junginių analizė ir antioksidacinio aktyvumo tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140701_144628-19868.
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Homeopatiniais vadinami preparatai, kurie yra pagaminti iš homeopatinių žaliavų, naudojant homeopatinės gamybos procedūras. Biologiniam homeopatinių preparatų aktyvumui tirti mokslininkai naudoja tuos pačius tyrimų metodus, kaip ir kitų rūšių cheminiams preparatams [32]. Šiam tyrimui pasirinkta homeopatinė juodojo riešuto (Juglans nigra L.) kevalo tinktūra ir jos D1 bei C1 praskiedimai – tai nedidelio laipsnio skiediniai, kuriuose veikliąsias medžiagas dar galima įdentifikuoti ir koncentracijas bei biologinį aktyvumą vertinti turimais tyrimo metodais.
Mokslinės literatūros šaltiniuose skelbiama, jog juodojo riešuto kevale yra devynios pagrindinės cheminės medžiagos [29]. Nustatyta, jog riešuto viena iš pagrindinių veikliųjų medžagų yra juglonas, kuris turi citotoksinių savybių prieš melonomos, kepenų, plaučių, širdies, kraujo ląsteles [25,28,38,39]. Kadangi mokslinių tyrimų su preparatais, pagamintais iš juodojo riešuto, atlikta nedaug, todėl buvo pasirinkta ištirti polifenolinių junginių, juglono kiekį pagamintuose tirpaluose bei nustatyti jų antioksidacines savybes.
Darbo tikslas:
Homeopatiškai paruošti iš juodojo riešuto kevalo pradinę tinktūrą ir jos D1 bei C1 praskiedimus, ištirti polifenolinių junginių, juglono kiekį ir įvertinti antioksidantinį aktyvumą.
Metodai:
Pagaminta pradinė homeopatinė tinktūra (urtinktūra) ir jos skiediniai pagal Homeopatijos farmakopėjos reikalavimus (HAB 2000, 3a taisyklė).
Spektrofotometriškai nustatytas polifenolinių junginių... [toliau žr. visą tekstą]Preparations referred to as homoeopathic are those made of homoeopathic raw materials using homoeopathic manufacturing procedures. In order to measure biological activity of homoeopathic preparations scientists use the same investigation methods as with other kinds of chemical products [30]. For this study homoeopathic tincture of black walnut (Juglans nigra L.) shell and its D1and C1 dilutions have been selected as these produce low-grade solutions in which active substances still can be identified and concentrations as well as bioactivity can be assessed by available methods of testing. The scientific literature sources state that the black walnut shell contains nine basic chemical substances [29]. It is found that one of the basic active ingredients is juglone which possesses cytotoxic properties effective against melanoma, the liver, lung, heart and blood cells. [25,28,38,39]. As the studies of black walnut preparations are not so common, we have chosen to investigate the juglone amount and polyphenolic compounds in solutions and to measure their antioxidant properties. The aim of the research: To produce homoeopathically original tincture of the black walnut shell and its D1 and C1 dilutions, to explore polyphenolic compounds, the level of juglone and evaluate their antioxidant activity. The methodology: Original homoeopathic tincture (urtincture) and its solutions were produced following the specification of Homoeopathy Pharmacopoeia (HAB 2000, rule 3a)... [to full text]
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Häusser, Michael. "Intrinsic properties and synaptic inhibition of substantia nigra neurones." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306691.
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Richards, Christopher David. "Electrophysiology and electrochemistry of substantia nigra neurones in vitro." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259895.
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Claro, Kleber del. "Polimorfismo mimetico de Scaphura nigra thunberg 1824 (tettigoniidal: phaneropterinae)." [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315993.
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Orientador : João Vasconcellos NetoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: De 1987 a 1990 foi estudado na floresta da Serra do Japi Jundiaí ¿ SP e no laboratório, a biologia e ecologia do ortóptero Scaphura nigra Thunberg 1824 (Tettigoniidae:Phaneropterinae). O estudo da biologia, comportamento, estridulação e história natural, revelou que S. nigra é polimórfico e mímico batesiano de vespas, havendo três padrões de coloração distintos para os adultos e que cada padrão do mímico tem um único gênero de vespa como modelo. Cada padrão recebeu aqui o nome genérico de sua vespa modelo, o padrão ¿Pepsis¿ mimetiza vespas do gênero Pepsis (Pompilidae), o ¿Entypus¿ mimetiza vespas do gênero Entypus (Pompilidae) e o ¿Polistes¿ mimetiza vespas do gênero Polistes (Vespidae). O padrão de coloração, morfologia, horário de atividade, substrato utilizado e comportamento, foram as principais semelhanças observadas entre mímicos e modelos. A dinâmica das populações mostrou que os mímicos podem ser mais abundantes que seus modelos em algumas épocas do ano, entretanto há uma probabilidade maior do encontro de um predador jovem ou inexperiente com um modelo antes que este se encontre com um mímico, pois mímicos só ocorreram no verão ao passo que modelos o ano todo. Seleção dependente de freqüência é aqui apontada como responsável pela evolução deste polimorfismo mimético batesiano. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: The biology and ecology of orthoptera Scaphura nigra Thunberg 1824 (Tettigoiidae: Phaneropterinae) was studied in the forest of Serra do Japi on southeastern Brazil and in laboratory. The study of behaviour, natural history and stridulation showed that S. Nigra is a polimorphic and batesian mimic of wasps, existing Three different colour patterns to the adults and each pattern of mimic has only one wasp genera like model. The study of populations showed that mimcs can be sometimes most abundant than models, however there is a major probability of encontering between a young predator with a model before it enconters a mimic, becuse mimic occur only in the summer and models during all year. Frequence dependent of selection is indicated here as responsible for evolution of this batesian polimorphic mimicry. ...Note: The complete abstract is available with the full electronic digital thesis or dissertations
Mestrado
Ecologia
Mestre em Ciências Biológicas
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Barstow, Karen L. "Subthalamic control of dopamine release in the substantia nigra." Thesis, Boston University, 2001. https://hdl.handle.net/2144/36754.
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Thesis (Ph.D.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
The overall goal of this dissertation was to determine the role of the subthalamic nucleus (STN) in regulating the release of dopamine in the substantia nigra (SN). Experiments first established the existence of a direct connection between subthalamic neurons and SN dopaminergic cells. Further experiments showed that this connection triggers the dopamine release in the SN, and the mechanisms involved in this release were determined. Whole-cell current clamp recordings were performed in parasagittal brain slices obtained from 10 to 16 day-old rat pups. Electrical stimulations of the STN reliably triggered excitatory post-synaptic potentials (EPSPs) in dopaminergic neurons of the SN pars compacta (SNc). Pharmacological experiments with specific receptor antagonists indicated that this EPSP was mediated by NMDA, non-NMDA and metabotropic glutamate receptors. Stimulations of the subthalamic input triggered the release of dopamine. In a subset of neurons in the SN pars reticulata (SNr), repetitive stimulations of the STN produced a summating EPSP that was followed by an inhibitory postsynaptic potential (IPSP). A D2 receptor antagonist blocked this IPSP suggesting that it represents the D2 receptor-mediated response of the recorded cell to dopamine released upon stimulation of the STN. Pharmacological experiments using this assay indicated that NMDA, non-NMDA or metabotropic glutamate receptors were individually not required for dendritic release of dopamine; however, each contributed to this release. In dopaminergic neurons located in the SN pars compacta, the inhibitory effect of dopamine was revealed following block of L-type Ca channels, NMDA and non-NMDA glutamate receptors. These results indicated that dopaminergic neurons located both in the SNc and SNr respond to the dendritic release of dopamine triggered upon stimulations of the STN. Finally, a specific blocker of the dopamine transporter (GBR12935) blocked the IPSP reversibly in both SNr and SNc dopaminergic neurons. If release occurred by exocytosis, block of the transporter should increase extracellular levels of dopamine and produce an increase in the size of the recorded IPSP. Therefore, these results suggest that dopamine dendritic release triggered by activation of the subthalamic input was mediated by reversed transport of dopamine rather than by exocytosis.
2031-01-01
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McCormack, Alison. "The non-human primate as a model of human parkinsonism /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-624-7/.
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Last, A. T. J. "An electrophysiological study of neurochemical interactions in the substantia nigra." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382628.
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Threlfell, Sarah. "The histaminergic regulation of serotonin release in the substantia nigra." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432289.
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Hallett, James Matthew. "Evidence for GluN3-containing receptors in rat substantia nigra neurones." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607886.
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Fearnley, Julian Michael. "Regional substantia nigra selectivity in the pathology of movement disorders." Thesis, University College London (University of London), 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319957.
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Silva, Selma do Nascimento. "ATIVIDADE FITOESTROGÊNICA DE Morus nigra L., MORACEAE, EM RATAS OVARIECTOMIZADAS." Universidade Federal do Maranhão, 2012. http://tedebc.ufma.br:8080/jspui/handle/tede/68.
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Previous issue date: 2012-10-02The hypoestrogenism in climacteric is associated with vasomotor symptoms, cardiovascular disease, osteoporosis and urogenital changes. At this stage of life of women, hormone replacement HRT can alleviate some consequences of decreased estrogen caused by ovarian failure. However, estrogen therapy may cause adverse effects such as breast tenderness, uterine bleeding and increase the relative risk for cancers of the breast and endometrium. Morus nigra L. (mulberry) is a plant species most used in Brazil for the treatment of menopausal symptoms. Thus, this study aims to assess the likely effects phytoestrogenics the hydroalcoholic extract (HE) from the leaves of M. nigra in ovariectomized female rats. Therefore, the dried leaves were pulverized and soaked in 70% ethanol in the proportion 1:3 (v/v) to obtain the HE (yield=21.90%). The HE was subjected to evaluation of the antioxidant activity by capturing free radical 2,2-diphenyl-1-picryl-hidrazil, analyzed by liquid chromatography coupled to mass spectrum (LC-MS/MS) for identification of compound and then partitioned with hexane, chloroform, ethyl acetate and methanol/water. The safety of extract was determined by the test of acute toxicity in mice at doses of 0.1 to 10.0 g/kg orally (p.o.). To evaluate the estrogenic activity of the extract from M. nigra leaves, the rats were divided into two control groups: sham-operated (SHAM) and ovariectomized (OVX), which received 0.1 mL/100 g saline, and two test groups: ovariectomized and treated with a solution estroprogestative (OVX-EP-50g/kg) and ovariectomized and treated with HE M. nigra 500mg/kg (OVX-HE500), n = 8-10, daily, p.o., for 14 weeks. Throughout the treatment period were analyzed the frequency stage of the estrous cycle, food intake and body weight. At the end of treatment were evaluated biochemical parameters and hormone, histomorphometry of the uterus, vagina and breast. Furthermore, the influence of M. nigra on the proliferation of breast tumor cell line MCF-7 was determined by MTT method. HE showed high antioxidant activity when compared to standard quercetin. The analysis by LC-MS/MS EH compared with literature data allowed the identification of flavonoids (kaempferol and quercetin) and quinic acid derivatives (caffeoylquinic acid and isomers dicaffeoylquinic acid). In the analysis of the estrous cycle, the group OVX-HE500 showed an increase in proestrous and estrous phases at 15.25% and 26.6%, respectively, when compared to OVX group. Ovariectomy caused an increase in body mass, which was prevented by treatment with HE and EP solution. The weight of abdominal adipose tissue was also significantly lower in groups OVX-HE and OVX-EP compared to the OVX group. Ovariectomy also induced atrophy of uterine tissue (OVX group) compared to SHAM group, indicating the efficiency of the surgical procedure, and the administration of EP significantly increased uterine weight compared with OVX group. Average uterine weight of the OVX-HE group was also higher than the OVX group, but smaller than the OVX-EP group. In the histological analysis, it was observed that the characteristics of the squamous epithelium of the vagina of OVX-EP group (57.79 ± 1.49m), relative to thickness, were similar to that of SHAM group (50 66 ± 1.60m). After 14 weeks of administration of HE was a partial reversal of vaginal atrophy (37.34 ± 1.77m), when compared to the OVX group (12.92 ± 0.53m), showing maturation of this tissue with the treatment, however, the HE did not alter breast tissue, unlike the stimulus EP-induced. Regarding biochemistry was observed that the treatments (HE and EP) reduced concentrations of triglycerides in 27.5% and 23.8% respectively, when compared to OVX. In in vitro tests, the data indicate that the HE M. nigra acts as a weak phytoestrogen and protects against cell proliferation of human breast carcinoma (MCF-7). In acute toxicity study, the treatment of mice with HE did not produce behavioral changes or deaths. Together, the data demonstrate that the HE M. nigra L. has beneficial effects in models of induced menopause in rats, decreased uterine and vaginal atrophy, without changing the mammary structure, improving triglyceride levels and shows up secure and potent oxidant activity. These effects may be related to their flavonoid constituents, and thus the plant species may be useful in controlling symptoms of menopause as an alternative to Hormone Replacement Therapy.
O hipoestrogenismo no climatério associa-se com sintomas vasomotores, doenças cardiovasculares, osteoporose e alterações urogenitais. Nesta fase da vida da mulher, a reposição hormonal pode amenizar algumas consequências da diminuição estrogênica ocasionada pela falência ovariana. Porém, a terapia estrogênica pode ocasionar efeitos adversos como mastalgia, sangramentos uterinos, além de aumentar o risco relativo para neoplasias de mama e endométrio. Morus nigra L. (amora) é uma das espécies vegetais mais utilizadas no Brasil para o tratamento dos sintomas do climatério. Assim, o presente estudo objetiva avaliar os prováveis efeitos fitoestrogênicos do extrato hidroalcoólico (EH) das folhas de M. nigra em ratas Wistar ovariectomizadas. Para tanto, as folhas secas foram pulverizadas e maceradas em etanol a 70% na proporção 1:3 (v/v), para obtenção do EH (rendimento=21,90%). O EH foi submetido à avaliação da atividade antioxidante pela captura do radical livre 2,2-difenil-1-picril-hidrazila, analisado por cromatografia líquida acoplada ao espectro de massa (LC-MS/MS) para identificação de composto e, em seguida, particionado com hexano, clorofórmio, acetato de etila e metanol/água. A segurança do extrato foi determinada pelo teste de toxidade aguda em camundongos, nas doses de 0,1 10,0g/kg, por via oral (v.o.). Para avaliar a atividade estrogênica do extrato das folhas de M. nigra, as ratas foram divididas em dois grupos controle: falso-operados (SHAM) e ratas ovariectomizadas (OVX), que receberam 0,1mL/100g de solução salina; e dois grupos teste: ovariectomizadas e tratadas com solução estroprogestativa (OVX-EP-50g/Kg) e ovariectomizadas e tratadas com EH de M. nigra 500mg/kg (OVX-EH500), n=8-10, diariamente, por v.o., durante 14 semanas. Durante todo o período de tratamento foram analisadas a frequência das fases do ciclo estral, a ingestão de alimentos e o peso corporal. Ao final do tratamento foram avaliados os parâmetros bioquímicos e hormonais, histomorfometria do útero, vagina e mama. Além disso, a influência de M. nigra sobre a proliferação de células tumorais de mama da linhagem MCF-7 foi determinada pelo método MTT. O EH apresentou alta atividade antioxidante quando comparada ao padrão quercetina. Na análise do EH por LC-MS/MS em comparação com dados da literatura permitiu a identificação de flavonoides (caempferol e quercetina) e derivados do ácido quínico (ácido cafeoilquínico e isômeros de ácido dicafeoilquínico). Na análise do ciclo estral, o grupo OVX-EH500 apresentou um aumento nas fases estro e proestro em 15,25% e 26,6%, respectivamente, quando comparado ao grupo OVX. A ovariectomia promoveu um aumento no peso corporal, que foi inibido pelo tratamento com o EH e solução EP. O peso do tecido adiposo abdominal também foi significativamente menor nos grupos OVX-EP e OVX-EH, quando comparados ao grupo OVX. A ovariectomia também induziu atrofia do tecido uterino (Grupo OVX) em comparação ao grupo SHAM, indicando a eficiência do procedimento cirúrgico; e a administração de EP aumentou significativamente o peso do útero em comparação com grupo OVX. A média do peso uterino do grupo OVX-EH também foi maior do que o grupo OVX, porém menor que o grupo OVX-EP. Quanto à análise histológica, observou-se que as características do epitélio escamoso da vagina do grupo OVX-EP (57,79 ± 1,49m), em relação à espessura, se assemelharam à das ratas do grupo SHAM (50,66 ± 1,60m). Após 14 semanas de administração de EH houve uma reversão parcial da atrofia vaginal (37,34 ± 1,77m), quando comparado ao grupo OVX (12,92 ± 0,53 m), mostrando maturação deste tecido com o tratamento; entretanto, o EH não alterou o tecido mamário, diferente do estímulo induzido pelo EP. Em relação à bioquímica foi observado que os tratamentos (EH e EP) reduziram as concentrações de triglicérides em 27,5% e 23,8% respectivamente, quando comparado ao grupo OVX. Nos testes in vitro, os dados indicam que o EH de M. nigra atua como um fraco fitoestrógeno e protege contra a proliferação de células de carcinoma de mama humano (MCF-7). No estudo toxicológico agudo, o tratamento de camundongos com o EH não produziu alterações comportamentais nem mortes. Em conjunto, os dados demonstram que o EH de M.nigra apresenta efeitos benéficos em modelos de hipoestrogenismo induzida em ratas, diminuindo a atrofia uterina e vaginal, sem alterar a estrutura mamária, melhorando os níveis de triglicérides, tendo potencial antioxidante, além de mostrar-se seguro. Esses efeitos podem estar relacionados com seus constituintes flavonoídicos, e dessa forma, a espécie vegetal pode ser útil no controle de sintomas da menopausa como uma alternativa para Terapia de Reposição Hormonal.
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Guilloux, Mariannick. "Les deux sureaux officinaux : "Sambucus nigra L., Sambucus ebulus L."." Paris 5, 1990. http://www.theses.fr/1990PA05P045.
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Bojovic, Srdjan R. "Biodiversité du pin noir (Pinus nigra Arn. ) en région méditerranéenne." Aix-Marseille 3, 1995. http://www.theses.fr/1995AIX30032.
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Pinus nigra arn. Est une espece collective presentant une distribution vaste et morcelee. Les diverses sous-especes sont interfertiles. Les evenements geologiques, climatiques et l'impact humain ont conduit les differents peuplements vers des derives genetiques. La systematique de cette espece a plusieurs fois ete mise en question. Dans cette etude nous testons cette systematique a l'aide des analyses terpeniques peu employe sur des pins noirs provenant de l'aire naturelle. Les analyses terpeniques ont prouvees l'existence d'unites infra-specifiques coincidant avec la repartition geographique. Les resultats corroborent la position taxinomique adoptee par plusieurs botanistes qui considerent pinus nigra comme espece et ses unites taxinomiques inferieures comme sous-especes. La subsp. Salzmanii est representee par les populations des cevennes et des pyrenees. La teneur elevee en caryophyllene et en limonene permet de la distinguer des 3 autres sous-especes. La subsp. Laricio est composee de 3 groupes bien distincts: corse, calabre et sicile. L'isolement du pin noir de corse est confirme par la plus forte teneur en b-phellandrene et t-ocimene et forte teneur en limonene. La subsp. Nigra, qui regroupe les populations de slovenie, italie du nord et autriche, et la subsp. Pallasiana, qui represente les populations de grece semble assez proche l'une de l'autre. La teneur elevee en germacrene-d et la faible teneur en myrcene rapproche ces deux sous-especes. Cependant les teneurs en -pinene, terpinolene et -humulene les distinguent
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Batista, Carla Isabel Soares. "Regulação dos níveis de GDNF na substantia nigra pelo estradiol." Master's thesis, Universidade de Aveiro, 2007. http://hdl.handle.net/10773/731.
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Mestrado em ToxicologiaO stress oxidativo ao nível da via nigroestriatal é reconhecido como uma das causas da degeneração dos neurónios dopaminérgicos da substantia nigra na doença de Parkinson (DP), sendo o efeito protector do estradiol recorrentemente associado à protecção contra o stress oxidativo. A acção protectora do estradiol na via nigroestriatal pode ainda envolver outros efeitos, tais como modulação da expressão de factores neurotróficos cuja capacidade de promover a sobrevivência neuronal é sobejamente conhecida. Neste trabalho analisámos a regulação dos níveis do factor neurotrófico derivado de uma linha de células da glia (GDNF) pelo 17β-estradiol na substantia nigra e determinámos qual a contribuição específica deste efeito para a acção neuroprotectora da hormona. Adicionalmente, estudámos a modulação do efeito do 17β-estradiol na expressão de GDNF por agentes oxidantes, levodopa (L-DOPA) e H2O2. Para determinar os níveis de GDNF procedemos a análise de Western-Blot em extractos de células pós-natais de substantia nigra em cultura após incubação com 17ß-estradiol. Realizámos estudos in vivo para determinar de que forma o 17ß-estradiol afecta a acção da toxina dopaminérgica 6-hidroxidopamina (6-OHDA), quer ao nível da viabilidade das células dopaminérgicas, como ao nível da expressão dos níveis de GDNF. Os resultados obtidos permitiram concluir que, em células pós-natais de substantia nigra em cultura, o 17ß-estradiol promoveu o incremento da expressão do GDNF pelos astrócitos, provavelmente via ligação a receptores membranares. Verificámos ainda que os efeitos do estradiol parecem ser potenciados pela a exposição a L-DOPA e H2O2. In vivo, o estradiol protegeu as células dopaminérgicas da substantia nigra da lesão causada por 6-OHDA, possivelmente através da estimulação da síntese de GDNF observada nestas condições. ABSTRACT: Estradiol is currently considered a neuroprotector agent of nigral dopaminergic neurons. Oxidative stress in the nigrostriatal pathway has been associated with the development of Parkinson disease and the protective effect of estradiol is thought to be associated with a defence against oxidative stress. The protection promoted by estradiol in nigrostriatal pathway may also be coupled to the expression of neurotrophic factors, molecules recognized by its capability to promote neuron survival. In this study we analysed how 17ß-estradiol regulates nigral glial cell line deriv GDNF levels and evaluated the contribution of this effect to the neuroprotective action of this hormone. We also assessed how levodopa (L-DOPA) and H2O2 modulated the effect of estradiol on GDNF expression. Western-Blot analysis was used to determine GDNF levels in cultured substantia nigra cells after incubation with 17ß-estradiol. Using in vivo studies we evaluated how 17ß-estradiol affects the action of the dopaminergic toxin - 6- hidroxydopamine (6-OHDA) on the dopaminergic cell viability and the expression of GDNF. Taken together the results showed that, in cultured postnatal substantia nigra cells, 17ß-estradiol promoted the increase of GDNF expression by astrocytes through activation of putative membrane receptors. Exposure to the oxidative agents L-DOPA and H2O2 augmented the effect of estradiol. In vivo, estradiol protected nigral dopaminergic cells from 6-OHDA induced injury, possibly through stimulation of GDNF synthesis.
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Riso, Sara Pedro Mendes. "Ecologia trófica da população de Ciconia nigra do Douro internacional." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/876.
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Mestrado em Ecologia, Biodiversidade e Gestão de EcossistemasNo presente trabalho estudaram-se algumas áreas húmidas no Parque Natural do Douro Internacional e zonas limítrofes, na tentativa de identificar que parâmetros físicos e biológicos são mais favoráveis à presença da Cegonhapreta (Ciconia nigra). A caracterização física das zonas húmidas foi assegurada por métodos de estimativa visual e recorrendo ao programa ArcView GIS 3.2.. Foram realizados transectos e amostragens com redes das comunidades faunísticas destes meios para a caracterização biológica. Após a análise estatística, os habitats de alimentação da espécie apresentaram-se significativamente diferentes dos locais onde esta não se alimenta, apresentando valores de profundidade média entre os 10 a 20 cm, cobertura fraca da área envolvente por zonas de pastoreio (0 a 20 %), vegetação aquática interior (0-20%) e elevados índices de qualidade da água e de abundância de anfíbios adultos. Foi ainda registado o comportamento alimentar da espécie nestes locais e as proporções dos vários itens-presa na dieta das crias de um dos casais mediante um sistema de vigilância implantado na imediação de um dos ninhos. Estas consumiram maioritariamente répteis pertencentes à Família Colubridae.
In the present study some wetlands in the Natural Park of the Douro Internacional, as much as its surrounding areas, have been studied, in an attempt to identify which physical and biological parameters can be considered to be more favorable to the presence of the Black stork (Ciconia nigra). The physical characterization of the wetlands was assured by methods of visual estimation and through ArcView GIS 3.2. Programe. Transects and net samplings were conduced to perform the biological characterization. Further statistical analysis, the species feeding habitats presented values of medium deep between the 10 and 20 cm, less coverage in terms of grazing areas (0 to 20 %), interior aquatic vegetation (0-20%) and high indexes of water quality and abundance of adult amphibians. The feeding behavior of the species and the proportions of the preys in the diet of one of the breeding pairs nestlings´ were studied trough the implementation of a monitoring system near the nest. They mainly consumed reptiles belonging to the Family Colubridae.
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Kerhoas, Daphne. "Male-infant interactions in wild crested black macaques, Macaca nigra." Doctoral thesis, Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-222030.
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Direct fitness is measured as the number of surviving offspring. Thus adult males may try to produce as many offspring as possible or to increase the survival of their offspring. Recent findings have shown the many potential benefits of fathers’ presence and support on infants’ development and survival. However, little is known about the influence of socio-ecological factors on male-infant interactions. The main aim of this thesis was therefore to investigate male-infant interactions in wild crested macaques (Macaca nigra). In particular, we aimed to examine the affiliative and agonistic interactions taking place in this species, along with the factors influencing these interactions and offspring survival. Data collection for this thesis took place in the Tangkoko-Duasudara Reserve in Sulawesi, Indonesia, on 3 wild groups of crested macaques. For the first study, data were collected on migrations, births, disappearances, and encounters between groups over 5 years. We analyzed the influence of socio-ecological factors (e.g. rainfall, alpha-male position takeover, and male hierarchy stability) on pre- and post-natal loss. The results showed that high infant mortality was mainly associated to male alpha-position takeover, which suggests that infanticide may indeed occur in this species. In addition, we found that female within-group competition for food sources and between-group resource defense influenced fetal and infant loss. Based on these findings, we were interested to see whether fathers protected their own offspring against male attacks. Thus, in the second study, we investigated the social determinants and characteristics of male-infant affiliations. Our results indicate that adult males and infants form preferential association, and that infants initiate the majority of male-infant affiliations. Infants initiated affiliations mainly towards a high ranking male or a male in a close relationship with their mother. In addition, infants affiliated mainly with adult males in the absence of their mother, while males affiliated mostly with infants when the infants‘ mother was present in proximity. Furthermore, males initiated affiliations towards an infant when they held a high rank or when they had a strong bond with the infant‘s mother. Interestingly, paternity did not affect male-infant affiliations. In conclusion, these studies provide insights in the specifics of both infant survival strategies and male reproductive strategies. In addition, we show that infants are active agents in establishing and maintaining preferential relationships with males. This thesis, thus, confirm that male-infant interactions, although rare, have a strong influence both on males’ and infants’ direct fitness.
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Feng, Lu. "Connexion entre modèles dynamiques de communautés végétales et modèles architecture-fonction – cas du modèle GreenLab." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20190/document.
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L'architecture des plantes est le résultat combiné des développements des structures topologique et géométrique qui interviennent dans l'acquisition de la biomasse et sa répartition sous l'influence des processus physiologiques. Pourtant cet aspect a été longtemps négligé dans la communauté des modèles dynamiques. Récemment les modèles structures fonction se sont montrés pertinents pour prendre en compte des questions comme les interactions plantes environnement (l'interception de la lumière), les interactions entre croissance et développement (répartition de la biomasse) en se plaçant au niveau de l'organe. Cependant les couts en calcul de la simulation numérique de ces processus rendent les applications impraticables en agriculture. Cette thèse vise a combiner le modèle structure fonction Greenlab avec d'une part un modèle de culture et d'autre part un modèle forestier basés sur le peuplement afin d'y introduire le concept d'architecture des plantes. Le modèle de culture Pilote fournit des prédictions de récoltes basés sur les paramètres de l'environnement (radiation, précipitations) et l'indice foliaire et l'indice de récolte. Une étude sur Maïs conjointe entre Pilote et GreenLab a permis d'expliciter en détail les paramètres de la production. Les indices foliaires et de récolte dépendent directement des paramètres sources puits, et la variabilité individuelle entre plantes est explicitée directement par les variations des retards a la germination et celles des surfaces disponibles par plantes (compétition spatiale). Tous ces paramétrés peuvent être calibré par méthodes inverses. Ainsi la jonction des deux types de modèles est réalisée au niveau du passage de la plante au peuplement.Une autre étude conjointe a été effectuée avec le modèle forestier empirique PNN qui modélise la croissance des peuplements forestiers de Pins noirs. A partir des données statistiques classiques sur les mesures de troncs et de houppiers, combinées avec les connaissances architecturales du Pin issues d'AMAP, GreenLab peut restituer l'architecture de l'arbre et visualiser des scenarios de sylviculture incorporant des élagages. Le procédé va jusqu'à l'obtention d'images de synthèse réalistes des peuplements. En conséquence il semble efficace de coupler les modèles de cultures et les modèles forestiers qui intègrent les connaissances écophysiologiques au niveau peuplement avec les modèles structures fonctions qui intègrent ces connaissances au niveau de l'architecture de la plante. Le modèle GreenLab par ses affinités avec ces deux types de modèles et ses performances en calcul, permet d'apporter un complément d'information essentiel sur la description du fonctionnement d'un peuplement tant du point de vue développement, que du point de vue des relations sources puits dans la plante. Enfin le modèle couplé a une plateforme comme Xplo (AMAP) permet en plus une simulation réaliste 3D du peuplement végétal aux divers stades de la croissancePlant architecture implies the development of both topological and geometrical structure over time, which determines resource acquisition, in the meantime interacts with physiological processes. However it has long been overlooked in traditional community dynamics models. Based on plant architecture, functional-structural plant models (FSPM) have showed their particular capability in addressing questions like interactions between plant and environment (e.g. light interception), between structure development and growth (e.g. carbon allocation), as they take into account morphogenesis with organ-level explicit descriptions. Anyway, high demand of time and memory for simulation and inverse calculation prevents FSPM from further agricultural or sylvicultural practice. This thesis attempts the combination of a mathematic FSPM GreenLab and a crop model or an empirical forest model (EFM) to introduce individual-based architectural support for community growth study. In the case of maize, disagreement from stand level (by crop model PILOTE) and individual level (by GreenLab) growth simulations implies different emergence time of individuals, which is used to quantify the distribution. By supposing that theoretical projective area (Sp) is determined by the growth situation and the final size of individual architecture, the variance of Sp is reversely computed with the variance of organ compartment measurements to characterize individual variability. In the case of Black pine, architecture dynamics built in GreenLab according to Rauh's model (architecture model for pine tree) are adapted to the simulation of an EFM PNN. As a consequence, thinning scenarios are well incorporated in the final stand visualization. From these preliminary applications, following conclusions can be drawn: (i) FSPM is able to provide individual performances (i.e. organ development and expansion) inside an area of crop field for crop models. (ii) The crop model may regulate the combined form of individuals from integral level. Both aspects are significant to deepen understanding of stand growth. (iii) Architecture conceptions integrated in FSPM may be adapted to EFM simulations for a data-driven visualization. (iv) EFM can guarantee ecological/sylvicultural function for 3D stand visualization. To take into consideration biomass processes, additional observations are needed. As models are independent in combinations, the same methods can be extended to linkage with other stand models
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Flowers, Jennifer Lee. "Localization of Diplodia pinea in diseased and latently-infected Pinus nigra." Lexington, Ky. : [University of Kentucky Libraries], 2005. http://lib.uky.edu/ETD/ukyplpa2006d00382/.
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Thesis (Ph. D.)--University of Kentucky, 2005.Title from document title page (viewed on March 2, 2006). Document formatted into pages; contains ix, 177 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 159-172).
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Neumann, Christof. "Achievement and maintenance of dominance in male crested macaques (Macaca nigra)." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-127628.
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Dominance rank often determines the share of reproduction an individual male can secure in group-living animals (i.e. dominance rank-based reproductive skew). However, our knowledge of the interplay between individual and social factors in determining rank trajectories of males is still limited. The overall aim of this thesis was therefore to investigate mechanisms that underlie individual dominance rank trajectories in male crested macaques (Macaca nigra) and to highlight potential individual and social determinants of how males can achieve and maintain the highest rank possible. Data for this thesis were collected on 37 males during a field study on a natural population of crested macaques living in the Tangkoko-Batuangus Nature Reserve in Indonesia. In study 1, I validate Elo-rating as a particularly well suited method to quantify dominance hierarchies in animal species with dynamic dominance relationships. In studies 2 and 3, I suggest a personality structure for crested macaque males consisting of five distinct factors and further demonstrate that two personality factors determine whether males will rise or fall in rank. Finally, in study 4, I present results on how males utilize coalitions to increase their future rank. Together, these results shed light on how individual attributes and social environment both can impact male careers. Ultimately, in order to understand what determines rank-based reproductive skew, we need to consider the complexity and likely diversity of the mechanisms underlying rank trajectories of individual males which are likely to differ across different species.
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Hicks, Gareth A. "Adenosine 5'-triphosphate-sensitive potassium channels in the rat substantia nigra." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321402.
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O'Callaghan, John Francis Xavier. "Mechanisms in neurochemical modulation in the substantia nigra : an electrophysiological study." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260149.
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Johnson, Otto Luke Ross. "Physiological and anatomical control of burst firing in the substantia nigra." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268205.
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Kapoor, Raju. "Studies of in vitro preparations of the cerebellum and substantia nigra." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.480555.
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Yung, Wing Ho. "Physiology and morphology of substantia nigra pars compacta neurones in vitro." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280920.
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Wild, Angela. "Regulation of NMDA receptors in substantia nigra pars compacta dopaminergic neurones." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608146.
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Brothwell, Shona Lindsay Crawford. "Properties of NMDA receptors in Substantia nigra pars compacta dopaminergic neurones." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612352.
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Zhao, Q. "Activation properties and pharmacology of NMDA receptors in rat substantia nigra." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1386599/.
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In this thesis i have used patch-clamp single channel and whole-cell recordings to quantify the properties of NMDA receptors in pars compacta of the substania nigra (SNc) dopaminergic neurons. NMDA receptors are ubiquitously expressed in the central nervous system and are generally composed of two glycine-binding GIuN1 subunits and two glutamate binding GIuN2 subunits. While many receptors are diheteromers of GluN1 and a single type of GiuN2 subunit, there is evidence for triheteromeric GIuN1/GIuN2B/GIuN2D receptors in the midbrain and cerebellum. Results suggest NMDA receptor activation in SNc dopaminergic neurons produces bursts of channel openings, which combined with the first latencies to activation, generate the familiar slowly rising and decaying macroscopic NMDA response. A modification to a standard kinetic model of NMDA receptor activation (the Banke & Traynelis model) was found to adequately fit the low NMDA concentration single channel data and the rate constants from this fitting predicted a macroscopic response to a brief pulse of 1 mM NMDA that was similar to that observed in concentration jump experiments. The co-localization of kinetically distinct GIuN2B and GIuN2D subunits in a single triheteromeric GluN1/GluN2B/GiuN2D receptor may account for the combination of pharmacological and kinetic properties observed in these experiments for NMDA receptors from the rat substantia nigra.
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Chevallier, Damien. "Ecologie de la cigogne noire (ciconia nigra) en Afrique de l'ouest." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. http://www.theses.fr/2007STR13108.
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Wright, Kristina M. "Revising the Role of the Ventrolateral Periaqueductal Gray in the Fear Circuit:." Thesis, Boston College, 2021. http://hdl.handle.net/2345/bc-ir:109159.
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Thesis advisor: Michael A. McDannaldThesis advisor: John P. Christianson
The ability to accurately evaluate and respond to threats is vital to survival. Disruptions in neural circuits of fear give rise to maladaptive threat responding, and have clinical implications in fear and anxiety disorders. To better inform therapeutic interventions, it is imperative that roles for regions classically associated with fear continue to be refined, and that novel nodes are incorporated into what is most certainly a larger fear circuit. In the canonical view, threat estimates are generated at the level of the amygdala and sent to the ventrolateral periaqueductal gray (vlPAG), which organizes an appropriate behavioral response, most notably freezing. Despite a multitude of studies successfully linking the vlPAG and Pavlovian fear behavior, evidence of a direct neural correlate for fear expression in the vlPAG is lacking. By contrast, a role for the caudal substantia nigra (cSN) in fear, stands apart from its canonical associations with movement and reward processes. Although there is new interest in examining a role for the nigra in fear modulation, this is essentially an uncharted area of discovery. The goals of this dissertation are three-fold. First, to propose a role for vlPAG activity in threat estimation, a function previously restricted to the upstream amygdala. Second, to scrutinize vlPAG neural activity using a novel multi-cue Pavlovian procedure and identify the long-anticipated, direct neural correlate for fear expression. Third, to present causal evidence supporting the cSN as a potential node in a circuit that most certainly extends beyond regions canonically associated with fear
Thesis (PhD) — Boston College, 2021
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Psychology
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Deutsch, Frank. "Erzeugung und Transformation haploider regenerativer Kallusse bei Populus nigra (L.) x hybrida." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971047634.
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Senarath, W. T. P. S. K. "In vitro propagation of Pinus nigra var. maritima (Ait.) Melville - Corsican pine." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307241.
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葉天恒 and Tin-hang James Yip. "Emotion recognition in patients with Parkinson's disease: contribution of the substantia nigra." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227016.
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Kingsbury, Ann Elizabeth. "In situ hybridization studies of human substantia nigra : pathophysiology of Parkinson's disease." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398427.
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Supriyanto. "Micropropagation de pinus nigra et pinus sylvestriS : Application à leurs hybrides interspécifiques." Nancy 1, 1989. http://www.theses.fr/1989NAN10253.
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(. . . ) La production massive de bourgeons axillaires et adventifs a été obtenue avec des apex de semis de 40 à 110 jours par P. Nigra et P. Sylvestris. Pour le développement de bourgeons axillaires et l'induction des bourgeons adventifs, le milieu minéral de Murashige et Skoog (MS) et le milieu organique de Bourgin et Nitsch (BN), tous les deux dilués deux fois (MSBN/2), ont été employés avec des rapports cytokinine : auxine variés. Le bourgeonnement total (axillaire et adventif) chez P. Nigra est plus élevé que chez P. Sylvestris, quelles que soient les conditions de culture. (. . . )
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Yip, Tin-hang James. "Emotion recognition in patients with Parkinson's disease : contribution of the substantia nigra /." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B24873007.
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GIUSTIZIERI, MICHELA. "Meccanismi di modulazione presinaptica nei neuroni dopaminergici della substantia nigra pars compacta." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2008. http://hdl.handle.net/2108/561.
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L’inibizione presinaptica è un meccanismo di modulazione sinaptica comunemente osservato nelle sinapsi del sistema nervoso centrale e periferico. Questo processo inizia in risposta all’attivazione di un’ampia varietà di recettori presinaptici e porta ad una riduzione della probabilità di fusione delle vescicole con la membrana del terminale sinaptico. Uno dei più comuni meccanismi d’azione consiste nell’inibizione dei canali del calcio voltaggio dipendenti (VDCCs) localizzati nei bottoni presinaptici. Tuttavia, esistono altre forme di inibizione presinaptica con meccanismi che coinvolgono direttamente la machinery di rilascio vescicolare. In questa tesi ho studiato il meccanismo di inibizione presinaptica mediata dal recettore metabotropico del glutammato del tipo III (mGluRs) e dal recettore GABAB nella trasmissione GABAergica dei neuroni dopaminergici della substantia nigra pars compacta (SNc) di ratto. L’AP-4 (100 μM), agonista selettivo del recettore metabotropico del glutammato del tipo III, e il baclofen (10 μM), agonista selettivo del recettore GABAB, riducono reversibilmente la frequenza delle correnti spontanee inibitorie post-sinaptiche (sIPSCs) rispettivamente del 48.5 ± 3.7 % e del 83.6 ± 2.3 % rispetto al controllo, senza avere alcun effetto sull’ampiezza della corrente. L’AP-4, non deprime la frequenza delle correnti inibitorie miniature post-sinaptiche (mIPSCs), registrate in tetrodotossina (TTX, 1 μM) e cadmio (100 μM), mentre è in grado di ridurre la frequenza delle mIPSCs del 75.3 ± 2.8 % rispetto al controllo, in presenza di TTX (1 μM) e bario (1 mM). Al contrario, il baclofen riduce la frequenza delle mIPSCs sia in cadmio (70.0 ± 6.7 % del controllo) sia in bario (52.3 ± 2.9 % del controllo). In TTX e ionomicina (2 μM), il baclofen riduce significativamente la frequenza delle mIPSCs del 71.8 ± 6.9 % del controllo, mentre l’AP-4 non ha effetto. In maniera simile, in presenza di TTX e α-latrotossina (α-LTX, 0.3 nM), la frequenza delle mIPSCs è diminuita del 64.5 ± 4.8 % del controllo dal baclofen, mentre mantiene gli stessi valori in presenza di AP-4. Infine, in continua presenza di baclofen, l’AP-4 non causa un ulteriore riduzione della frequenza delle sIPSCs. La conclusione di questi studi è che i recettori metabotropici del glutammato del tipo III deprimono il rilascio di GABA dai neuroni dopaminergici della SNc , attraverso l’inibizione dei VDCC, mentre i recettori presinaptici GABAB coinvolgono direttamente il rilascio vescicolare del neurotrasmettitore. Inoltre questi due diversi meccanismi di inibizione pre-sinaptica coesistono nello stesso terminale sinaptico. Questa caratterizzazione fornisce nuove conoscenze sul ruolo di questi recettori presinaptici nello studio della fisiologia della substantia nigra e nel loro potenziale uso come target nel trattamento farmacologico di malattie neurodegenerative come il morbo di Parkinson.Presynaptic inhibition is a mechanism of synaptic modulation normally observed in the synapses of the nervous system. This process starts upon activation of a large number of presynaptic receptors and leads to the decreased probability of vesicles to fuse to the cell membrane. One of the most common mechanism consists in the inhibition of the voltage dependent calcium channels (VDCC) located on the active zone of the presynaptic neuron. However, there is evidence for another form of presynaptic inhibition with a direct impairment of the vescicular release machinery. In my thesis I have investigated the mechanisms of presynaptic inhibition by group III metabotropic glutamate receptors (mGluRs) and GABAB receptors of the GABAergic neurotransmission to dopamine (DA) neurones of the rat substantia nigra pars compacta (SNc). The group III mGluRs agonist L-(+)-2-amino-4-phosphonobutyric acid (AP4, 100 μM) and the GABAB receptor agonist baclofen (10 μM) reversibly depressed the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) to 48.5 ± 3.7 % and 83.6 ± 2.3 % of control, respectively, with no effect in their amplitude. AP4 did not affect miniature inhibitory postsynaptic currents (mIPSCs) recorded in tetrodotoxin (TTX, 1 μM) and cadmium (100 μM), while in TTX (1 μM) and barium (1 mM), mIPSCs frequency was reduced to 75.3 ± 2.8 % of control. In contrast, baclofen reduced mIPSCs frequency either in cadmium (70.0 ± 6.7 % of control) or barium (52.3 ± 2.9 % of control). In TTX and ionomycin (2 μM), baclofen significantly reduced mIPSCs frequency to 71.8 ± 6.9 % of control, while AP4 had no effect. Similarly, in TTX and α-latrotoxin (α-LTX, 0.3 nM), the frequency of mIPSCs was reduced by baclofen to 64.5 ± 4.8 % of control, but was insensitive to AP4. Finally, in the continuous presence of baclofen, AP4 failed to produce any further reduction of sIPSCs frequency. The conclusion of this study is that group III mGluRs depress GABA release to DA neurons of the SNc through inhibition of presynaptic voltage-dependent calcium channels, while presynaptic GABAB receptors also impair transmitter exocytosis, and both mechanisms coexist on the same synapses. This characterization provides new insights about the role of these presynaptic receptors in the physiology of the substantia nigra and their potential involvement in the treatment of neurodegenerative diseases such as Parkinson’s Disease.
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Tommasi, Alessio <1989>. "La biologia della riproduzione: test di germinazione su semi di Populus nigra." Master's Degree Thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/6057.
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ABSTRACT
La diversità in specie animali, vegetali, funghi, batteri e virus del nostro pianeta rappresenta la biodiversità. La salvaguardia di tali specie può avvenire in due modalità distinte: “in situ” o “ex situ”. La conservazione “ex situ” viene definita dalla Convenzione sulla Diversità Biologica del 1992 come “la conservazione di elementi costitutivi della diversità biologica fuori dal loro ambiente naturale”. La conservazione in situ (aree di origine) e quella on farm (nelle aree di coltivazione) sono prioritarie, ma quella ex situ (banche genetiche, collezioni, orti botanici, ecc.) si rende indispensabile in quei casi in cui le prime due, per motivi diversi, sono difficili da realizzare. Nel caso delle specie vegetali, consiste nel mantenimento del germoplasma, cioè di quel materiale ereditario contenuto in parti vive, soprattutto semi e piante, ma anche spore, pollini e tessuti meristematici. La conservazione avviene a basse temperature, anche mediante il congelamento di semi o di altro materiale vivente. L’obbiettivo è quello di contrastare la perdita di biodiversità e del patrimonio genetico vegetale attraverso una politica di sicurezza e prevenzione.
La conservazione avviene in centri denominati “banche del germoplasma” come il famoso Svalbard Global Seed Vault. Il Centro Nazionale per la Biodiversità Forestale di Peri (Vr) si occupa della raccolta, dell’analisi e del successivo deposito in celle frigorifere di semi delle specie iscritte al Libro Nazionale dei Boschi da Seme (L.N.B.S.). Per stabilire quali lotti di semi possiedono caratteristiche adeguate alla conservazione, è necessario eseguire vari test su di essi (germinazione, tetrazolo, umidità, purezza specifica, peso di mille semi). Tali test qualitativi, di tipo fisico e fisiologico, forniscono indicazioni sulle caratteristiche dei semi che compongono il lotto permettendo in definitiva di fare le opportune valutazioni per un loro possibile utilizzo in ottica di conservazione o per effettuare reintroduzioni in natura.
I laboratori che effettuano questi test vengono valutati attraverso metodologie standardizzate e sistemi di qualità, Il presente lavoro si basa sull’applicazione del “Proficiency Test”, strumento utilizzato per valutare l’operato dei laboratori analisi sementi e dei tecnici che vi lavorano, ad un lotto di semi della specie Fagus sylvatica. La parte pratica del lavoro ha riguardato la preparazione dei campioni, rappresentativi di un lotto iniziale, per lo svolgimento di questo test. Le indicazioni e le procedure vengono fornite dall’International Seed Testing Association (ISTA) che ha il compito di coordinare tale lavoro. Per valutare l’omogeneità dei campioni di Fagus sylvatica preparati, è stato svolto un “Heterogeneity Test”. Con lo stesso scopo di valutare le capacità tecniche di un laboratorio è stato preparato ed eseguito, un “Comparative Test” su semi di Populus nigra, che ha visto coinvolti sei laboratori sementi italiani.
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GAMBARDELLA, Cristina. "Caratterizzazione della corrente h in neuroni dopaminergici della substantia nigra pars compacta." Doctoral thesis, Università degli studi di Ferrara, 2011. http://hdl.handle.net/11392/2388763.
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1. Introduzione
I neuroni dopaminergici (DA) della substantia nigra pars compacta (SNc) sono tra i più studiati nel sistema nervoso centrale per la loro implicazione nella malattia del Parkinson. Essi presentano un ampio corredo di correnti voltaggio-dipendenti, tra le quali emerge una tipica corrente attivata da iperpolarizzazione, la Ih. Diversamente dalla maggior parte delle cellule nervose, i neuroni dopaminergici della SNc presentano una attività spontanea regolare dopo isolamento o riduzione degli input sinaptici, e non è, quindi, sorprendente che numerosi lavori abbiano indagato il ruolo della Ih nell'attività spontanea. Tuttavia il ruolo della Ih non è stato ancora ben compreso, dal momento che il blocco di questa corrente non sembra comportare nessuna alterazione significativa della frequenza di scarica.
Abbiamo, allora, riesaminato il problema studiando la corrente h, in fette sottili di cervello, in condizioni sperimentali che si differenziano dalla maggior parte degli studi precedenti per tre aspetti fondamentali:
i) abbiamo utilizzato topi transgenici che esprimono una proteina reporter (GFP) sotto il promotore tirosina idrossilasi (TH), per identificare i neuroni DA della SNc;
ii) abbiamo effettuato le registrazioni elettrofisiologiche a 37°C;
iii) abbiamo eseguito la maggior parte degli esperimenti in condizioni di patch perforato al fine di lasciare inalterato l’ambiente fisiologico intracellulare.
2. Risultati
Il nostro primo obiettivo è stato quello di effettuare un'analisi dettagliata della dipendenza della cinetica e dell’ampiezza della Ih dalla temperatura. Il protocollo di attivazione della corrente h prevedeva una serie di comandi iperpolarizzanti della durata di 4s e le registrazioni erano effettuate a 27°C e 37°C. Abbiamo calcolato che il coefficiente di temperatura (Q10) per la variazione di ampiezza della corrente h è pari 3,73, mentre i valori di Q10 relativi alle velocità di attivazione e deattivazione sono rispettivamente pari a 10,8 e 3,17. Il V50 è di -94,9 ± 1,07 mV a 27°C (n = 13) e -84,2 ± 1,31 mV a 37°C (n = 18).
Abbiamo, successivamente, esaminato la modulazione da parte dei nucleotidi ciclici in condizioni di patch perforato a 37°C, in presenza di forskolina (10 μM), un attivatore della adenilato ciclasi, e IBMX (0.1 mM), un inibitore delle fosfodiesterasi, i quali, insieme, inducono un aumento della concentrazione intracellulare di adenosina monofosfato ciclico (cAMP). In queste
condizioni abbiamo registrato un aumento dell'ampiezza Ih (da -178,53 ± 23,48 pA in condizioni di controllo a -227,01 ± 34,17 pA con forskolina a -130 mV, n = 8), uno spostamento del V50 di + 4,80 ± 0,68 mV (n = 8) e una riduzione delle costanti di tempo di attivazione di circa il 25%.
Dato che questa modulazione è il risultato di un’interazione diretta del cAMP con il canale, abbiamo studiato gli effetti sulla Ih di diversi neurotrasmettitori accoppiati a proteine Gi o Gs, in particolare abbiamo testato la dopamina, la serotonina (5-HT) e la noradrenalina (NA). Il quinpirolo, un agonista dei recettori dopaminergici D2 (30 μM, dopo 3 minuti di applicazione nel bagno), ha indotto una diminuzione dell'ampiezza della Ih del 15% a -130 mV (n = 6), mentre il sulpiride, un antagonista dei recettori dopaminergici D2 (20 μM), ne ha determinato un aumento (n = 5). L'effetto sulla Ih della 5HT (100 μM), dopo 3 minuti di applicazione nel bagno, è stato una riduzione dell’ampiezza del 20% (n = 5); al contrario, l'applicazione nel bagno della NA (100 μM), ne ha indotto un aumento di circa il 12% (n = 8).
Infine, abbiamo analizzato il ruolo della corrente h sull’autoritmicità. L'ivabradina (10 μM), bloccante del Ih, ha determinato una marcata iperpolarizzazione (circa -10 mV), che di fatto ha silenziato le cellule; tuttavia, questo effetto sull’attività spontanea era indiretto, poiché se la membrana era ripolarizzata, l’autoritmicità si ripristinava.
3. Conclusioni
Gli studi eseguiti a temperatura ambiente sul ruolo e le proprietà della corrente h nei neuroni dopaminergici della SNc sono scarsamente informativi perché, in queste condizioni sperimentali, la corrente è sottovalutato in ampiezza, velocità e, in ultima analisi, nella sua capacità di svolgere alcun ruolo a potenziali fisiologici. Le registrazioni elettrofisiologiche a 37°C, invece, restituiscono un profilo più accurato e veritiero della Ih.
La modulazione della corrente h ad opera di sistemi a secondo messaggero, un processo scarsamente esplorato nei neuroni dopaminergici della SNc, sembra essere rilevante, e suggerisce l'esistenza di diversi pathways importanti per il controllo dell’eccitabilità neuronale.
La corrente h è, in ultima analisi, molto importante nell’autorimicità perché stabilizza il potenziale di membrana di riposo dei neuroni dopaminergici della SNc in uno stato depolarizzato, ma non ricopre un ruolo di principale nell’attività pacemaker.
Questi risultati sono interessanti perché aprono nuove prospettive sul ruolo del canale HCN nei neuroni dopaminergici della substantia nigra pars compacta.