Academic literature on the topic 'Broadsides, et'

Traditional bearing estimation systems exploit relative time delays across an array of sensors to localize a target. While highly effective, such systems are costly and cumbersome. Yovel et al. (Science, 2010) found that bats steer their echolocation beams off axis to maximize the Fisher information, implying that spectral magnitude cues improve target localization. This presentation shares experiments demonstrating a man-made system estimating a target's bearing from echo spectrum magnitude-information using a single directional sensor with frequency dependence over the bandwidth of the signal. The output of a 31-element microphone array steered to broadside serves as the frequency dependent directional sensor. Moving a source transmitting a linear FM chirp across a range of angles estimates the beampattern of the receiver. Maximum likelihood estimation using these recorded replicas gives the mean-squared error (MSE) as a function of angle. The MSE is compared with the Cramer-Rao lower bound. Moving away from broadside reduces the received SNR, but paradoxically the MSE exhibits local minima. These MSE local minima are consistent with the optimal angles observed in previous research simulating the impact of magnitude cues (Kloepper et al., JASA-EL, 2018; Tidwell et al., IEEE SSPD, 2019). [Work supported by ONR MURI Program.]

Abstract A model was recently proposed to predict the target strengths (TS) of Antarctic krill, Euphausia superba, versus incidence angle (θ) (Deep Sea Res. II 45(7) (1998) 1273). Based on the distorted-wave Born approximation (DWBA), the model depends on the coherent summation of scattering from elements of a discretized-bent cylinder. It was empirically validated at 120 kHz near-broadside incidence (θ≈90°), but large discrepancies were observed at other angles away from the main lobe. As the side-lobe measurements were both higher than the model predictions and above the noise floor, the authors noted that the differences were not entirely due to noise. In this study, the accuracy of the DWBA model is further explored. Results indicate that phase variability in the scatter from elements of a discretized-bent cylinder (krill model) causes a dramatic flattening in the side-lobe regions of TS(θ), while negligibly affecting the main scattering lobe. These results are consistent with the krill TS measurements reported by McGehee et al. Thus, by accounting for phase variability in the solution of the DWBA model, a more accurate and thus practical tool is developed for predicting krill TS.

Purpose: To describe the successful management of a rare non-obstetric vulvar hematoma. Background: While vulvar hematomas are common in obstetric cases, vulvar hematomas due to non-obstetric trauma are rare, representing only 0.8% of all gynecological emergencies. The vulva is made primarily of loose connective tissue richly supplied by branches of the pudendal artery, so it is susceptible to injury by multiple different types of trauma. Because non-obstetric vulvar hematomas are so rare, there is no established consensus for management. In this article, we shall present a patient who, after sustaining multiple injuries from a motor vehicle collision, developed a large vulvar hematoma that was successfully treated with surgical evacuation. Case Description: A healthy 26-year-old female presented to the emergency department following a broadside motor vehicle collision. CT with contrast described multiple pelvic fractures as well as a small volume retroperitoneal hemorrhage anterior to the bladder. There was no evidence of bladder injury or other areas of extravasation. On hospital day 1, she underwent uncomplicated open reduction and internal fixation of pelvic and sacral ring fractures. On hospital day 3, the patient began noticing a painful, rapidly expanding labial hematoma, and OBGYN services were consulted. Despite conservative management with ice and analgesics, the patient described the pain as 10 out of 10. On physical exam the right vulva was found to have a 14 cm hematoma expanding down to the perineum and extending to include the labia majora and labia minora. The area was extremely edematous and tender to light palpation. Swelling distorted the anatomy, occluding the vaginal introitus and obscuring the left labia. A Foley catheter was draining clear urine from the bladder. The following morning, the hematoma had continued to expand and Hgb significantly decreased, so the decision was made to proceed with surgical management. Pre-operative antibiotics were given, and the patient was prepped and draped according to hospital protocol. Hart’s line was injected with a marcaine/lidocaine/epinephrine premixed solution for hemostasis. A 3 cm vertical incision was created along Hart’s line, and the space was bluntly entered using a hemostat. Clotted blood was evacuated from the labial space, and active bleeding was ligated with using Vicryl. Once hemostasis was noted, the incision was loosely closed with interrupted stitches placed widely apart to allow for drainage. The vagina and left labia were examined and found to be normal. The right labial space was packed using kerlix, and the patient was prescribed a 7-day course of oral antibiotics. The patient tolerated the procedure well and reported no vulvar pain on post-op day 1. The vulvar packing was removed without incident, and no bleeding was noted from the incision site. The patient was reevaluated by the OBGYN team on post-op day 8 and was healing very well. She reported very little pain and had no issues with spontaneous urination. On physical exam, the hematoma was nontender to palpation and measured approximately 10 x 5 x 2.5 cm with decreased bruising and areas of discoloration. The patient was discharged with no further issues. Despite multiple attempts to schedule an outpatient appointment, the patient was unfortunately lost to follow-up. Discussion: Non-obstetric vulvar hematomas due to non-obstetric trauma are rare, and with improper management, may lead to significant morbidity. However, there is no established consensus for management, and little literature is available for guidance. Some small studies have reported success with conservative management. Benrubi et al, however, observed that conservative management of vulvar hematomas may be associated with longer hospital stays and increased need for antibiotics and blood transfusions10. A recent retrospective analysis also suggests a preference for surgical management, as a significantly reduced mortality rate was observed in patients who underwent surgical intervention for non-obstetric vulvar trauma. The same study found that while the surgical cohort tended to require a slightly longer hospital stay, there were no differences in ICU days, ventilator days, or rates of UTI between cohorts who had undergone surgical management and those who had undergone conservative management1. Arterial embolization has also been described as an alternative to surgical intervention in select patients, but this approach requires equipment and specialized personnel that may not be readily available to all institutions. Some case studies suggest using rate of expansion or hemodynamic instability as indications for surgical management. Size of the hematoma may also be considered as evidence suggests vulvar hematomas with a diameter greater than 4 cm have a higher potential for skin necrosis. Even when surgical management is clearly indicated there is little data regarding an optimal surgical approach. Conclusion: In this article, we discuss the successful surgical management and short-term follow up of a very large non-obstetric vulvar hematoma. We hope that our surgical approach can add to the small pool of literature available on these rare gynecological cases and help guide future research into developing standardized management guidelines.

Purpose: To describe the successful management of a rare non-obstetric vulvar hematoma. Background: While vulvar hematomas are common in obstetric cases, vulvar hematomas due to non-obstetric trauma are rare, representing only 0.8% of all gynecological emergencies. The vulva is made primarily of loose connective tissue richly supplied by branches of the pudendal artery, so it is susceptible to injury by multiple different types of trauma. Because non-obstetric vulvar hematomas are so rare, there is no established consensus for management. In this article, we shall present a patient who, after sustaining multiple injuries from a motor vehicle collision, developed a large vulvar hematoma that was successfully treated with surgical evacuation. Case Description: A healthy 26-year-old female presented to the emergency department following a broadside motor vehicle collision. CT with contrast described multiple pelvic fractures as well as a small volume retroperitoneal hemorrhage anterior to the bladder. There was no evidence of bladder injury or other areas of extravasation. On hospital day 1, she underwent uncomplicated open reduction and internal fixation of pelvic and sacral ring fractures. On hospital day 3, the patient began noticing a painful, rapidly expanding labial hematoma, and OBGYN services were consulted. Despite conservative management with ice and analgesics, the patient described the pain as 10 out of 10. On physical exam the right vulva was found to have a 14 cm hematoma expanding down to the perineum and extending to include the labia majora and labia minora. The area was extremely edematous and tender to light palpation. Swelling distorted the anatomy, occluding the vaginal introitus and obscuring the left labia. A Foley catheter was draining clear urine from the bladder. The following morning, the hematoma had continued to expand and Hgb significantly decreased, so the decision was made to proceed with surgical management. Pre-operative antibiotics were given, and the patient was prepped and draped according to hospital protocol. Hart’s line was injected with a marcaine/lidocaine/epinephrine premixed solution for hemostasis. A 3 cm vertical incision was created along Hart’s line, and the space was bluntly entered using a hemostat. Clotted blood was evacuated from the labial space, and active bleeding was ligated with using Vicryl. Once hemostasis was noted, the incision was loosely closed with interrupted stitches placed widely apart to allow for drainage. The vagina and left labia were examined and found to be normal. The right labial space was packed using kerlix, and the patient was prescribed a 7-day course of oral antibiotics. The patient tolerated the procedure well and reported no vulvar pain on post-op day 1. The vulvar packing was removed without incident, and no bleeding was noted from the incision site. The patient was reevaluated by the OBGYN team on post-op day 8 and was healing very well. She reported very little pain and had no issues with spontaneous urination. On physical exam, the hematoma was nontender to palpation and measured approximately 10 x 5 x 2.5 cm with decreased bruising and areas of discoloration. The patient was discharged with no further issues. Despite multiple attempts to schedule an outpatient appointment, the patient was unfortunately lost to follow-up. Discussion: Non-obstetric vulvar hematomas due to non-obstetric trauma are rare, and with improper management, may lead to significant morbidity. However, there is no established consensus for management, and little literature is available for guidance. Some small studies have reported success with conservative management. Benrubi et al, however, observed that conservative management of vulvar hematomas may be associated with longer hospital stays and increased need for antibiotics and blood transfusions10. A recent retrospective analysis also suggests a preference for surgical management, as a significantly reduced mortality rate was observed in patients who underwent surgical intervention for non-obstetric vulvar trauma. The same study found that while the surgical cohort tended to require a slightly longer hospital stay, there were no differences in ICU days, ventilator days, or rates of UTI between cohorts who had undergone surgical management and those who had undergone conservative management1. Arterial embolization has also been described as an alternative to surgical intervention in select patients, but this approach requires equipment and specialized personnel that may not be readily available to all institutions. Some case studies suggest using rate of expansion or hemodynamic instability as indications for surgical management. Size of the hematoma may also be considered as evidence suggests vulvar hematomas with a diameter greater than 4 cm have a higher potential for skin necrosis. Even when surgical management is clearly indicated there is little data regarding an optimal surgical approach. Conclusion: In this article, we discuss the successful surgical management and short-term follow up of a very large non-obstetric vulvar hematoma. We hope that our surgical approach can add to the small pool of literature available on these rare gynecological cases and help guide future research into developing standardized management guidelines.

Les travaux menés dans le cadre de cette thèse proposent de tirer profit des nouvelles technologies disponibles pour répondre aux besoins de la montée en fréquence et de la miniaturisation des systèmes de communication tout en améliorant le niveau des performances. Les études se sont axées vers la conception d'une structure à mélangeur de réjection de fréquence image permettant de relâcher les contraintes sur les structures critiques de filtrage amont. L'intégration des parties actives et passives de ce système, a ainsi été menée avec comme objectifs de tirer au maximum partie des potentialités de chaque technologie, de proposer des solutions techniques pour palier aux inconvénients de chaque technologie, et d'optimiser l'architecture globale en partitionnant le système suivant les contraintes technologiques et/ou techniques. La première partie des travaux a ainsi porté sur le développement en bande K d'une nouvelle topologie de mélangeur à base de transistors à hétérojonction Si-SiGe à linéarité améliorée. Se basant sur une compréhension des phénomènes intrinsèques du circuit, des topologies modifiées ont de plus été proposés afin de repousser l'ensemble des performances atteignables sur cette technologie. La seconde partie des travaux concerne la conception de coupleurs passifs, toujours en bande K, avec pour objectif la miniaturisation maximale de ces fonctions. Une méthodologie de conception a, dans ce cadre, été développée et validée par une intégration sur une technologie spécifiquement développée au LAAS-CNRS et compatible avec une future intégration avec les circuits actifs. Nous avons ainsi obtenu des performances optimales (à l'état de l'art) avec un gain d'intégration d'un facteur 2. Enfin, en amont et en aval de ces travaux, une étude sur l'architecture globale du système de mélangeur à réjection de fréquence image a été conduite, et sans cesse raffinée, afin de partitionner les contraintes de performances entre les différents blocs et de vérifier l'obte ntion des performances.