7,371 research outputs found

    Supervisors Without Supervision: \u3cem\u3eColon\u3c/em\u3e, \u3cem\u3eMcKenna\u3c/em\u3e, and the Confusing State of Supervisory Liability in the Second Circuit

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    This Note received the 2019 Washington and Lee Law Council Law Review Award. This Note analyzes two intra-Second Circuit splits that make it nearly impossible for prisoners to recover against supervisors under § 1983. First, district courts in the Second Circuit are divided as to whether the five categories of personal involvement defined in Colon v. Coughlin survive the Supreme Court’s decision in Ashcroft v. Iqbal. Personal involvement by the supervisory defendant is a necessary element to impose supervisory liability. Some district courts hold that only the first and third Colon factors survive Iqbal, while others hold that all five factors still apply. Second, district courts in the Second Circuit are divided as to whether a supervisor is personally involved in a constitutional tort when he or she rejects a prisoner’s grievance complaining of the misconduct. Some district courts always find personal involvement when a supervisor denies a grievance without considering any other factors. Other district courts only find personal involvement when a supervisor investigates the alleged misconduct or answers the grievance with a detailed response. The Second Circuit must resolve both intra-circuit splits to give full effect to § 1983 because the disagreement allows district courts to dismiss claims on qualified immunity grounds. Government officials are immune from suit and “entitled to qualified immunity” if their actions “did not violate clearly established law.” District courts point to both of the intra-circuit splits as evidence that the law surrounding supervisory liability is not clearly established and therefore grant supervisory defendants qualified immunity. The confusion surrounding supervisory liability in the Second Circuit perfectly encapsulates how legislatures and courts have quietly dismantled § 1983 as a viable cause of action for prisoners in recent years. Congress passed § 1983 with bold aspirations to punish oppressive government actors who abuse their power by infringing on individuals’ constitutional rights. Given how vulnerable prisoners are by virtue of their incarceration, § 1983 serves as one of the only practical tools they have to put them on equal footing with their government custodians. As the law currently stands in the Second Circuit, this tool is broken

    Variable Hard X-ray Emission from the Candidate Accreting Black Hole in Dwarf Galaxy Henize 2-10

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    We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2-10. Recent observations suggest that this galaxy hosts an actively accreting black hole with mass ~10^6 M_sun. The presence of an AGN in a low-mass starburst galaxy marks a new environment for active galactic nuclei (AGNs), with implications for the processes by which "seed" black holes may form in the early Universe. In this paper, we analyze four epochs of X-ray observations of Henize 2-10, to characterize the long-term behavior of its hard nuclear emission. We analyze observations with Chandra from 2001 and XMM-Newton from 2004 and 2011, as well as an earlier, less sensitive observation with ASCA from 1997. Based on detailed analysis of the source and background, we find that the hard (2-10 keV) flux of the putative AGN has decreased by approximately an order of magnitude between the 2001 Chandra observation and exposures with XMM-Newton in 2004 and 2011. The observed variability confirms that the emission is due to a single source. It is unlikely that the variable flux is due to a supernova or ultraluminous X-ray source, based on the observed long-term behavior of the X-ray and radio emission, while the observed X-ray variability is consistent with the behavior of well-studied AGNs.Comment: 7 pages, 4 figures, 2 tables; accepted for publication in Ap

    Photoreceptor Inner Segment Morphology in Best Vitelliform Macular Dystrophy

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    PURPOSE To characterize outer retina structure in best vitelliform macular dystrophy (BVMD) and to determine the effect of macular lesions on overlying and adjacent photoreceptors. METHODS Five individuals with BVMD were followed prospectively with spectral domain optical coherence tomography and confocal and nonconfocal split-detector adaptive optics scanning light ophthalmoscopy (AOSLO). The AOSLO cone photoreceptor mosaic images were obtained within and around retinal lesions. Cone density was measured inside and outside lesions. In 2 subjects, densities were compared with published measurements acquired ∌2.5 years before. One subject was imaged 3 times over a 5-month period. RESULTS The AOSLO imaging demonstrated that photoreceptor morphology within BVMD retinal lesions was highly variable depending on the disease stage, with photoreceptor structure present even in advanced disease. The AOSLO imaging was repeatable even in severe disease over short-time and long-time intervals. Photoreceptor density was normal in retinal areas immediately adjacent to lesions and stable over ∌2.5 years. Mobile disk-like structures possibly representing subretinal macrophages were also observed. CONCLUSION Combined confocal and nonconfocal split-detector AOSLO imaging reveals substantial variability within clinical lesions in all stages of BVMD. Longitudinal cellular photoreceptor imaging could prove a powerful tool for understanding disease progression and monitoring emerging therapeutic treatment response in inherited degenerations such as BVMD

    An In Vitro Study of the Role of Implant Positioning on Ulnohumeral Articular Contact in Distal Humeral Hemiarthroplasty

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    © 2017 American Society for Surgery of the Hand Purpose To investigate the effect of implant positioning on ulnohumeral contact using patient-specific distal humeral (DH) implants. Methods Seven reverse-engineered DH implants were manufactured based on computed tomography scans of their osseous geometry. Native ulnae were paired with corresponding native humeri and custom DH implants in a loading apparatus. The ulna was set at 90° of flexion and the humeral component (either native bone or reverse-engineered implant) was positioned from 5° varus to 5° valgus in 2.5° increments under a 100-N compressive load. Contact with the ulna was measured with both the native distal humerus and the reverse-engineered DH implant at all varus-valgus (VV) angles, using a joint casting method. Contact patches were digitized and analyzed in 4 ulnar quadrants. Output variables were contact area and contact pattern. Results Mean contact area of the native articulation was significantly greater than with the distal humeral hemiarthroplasty (DHH) implants across all VV positions. Within the native condition, contact area did not significantly change owing to VV angulation. Within the DHH condition, contact area also did not significantly change owing to VV angulation. Conversely, in the DHH condition, contact pattern did significantly change. Medial ulnar contact pattern was significantly affected by VV angulation. Lateral ulnar contact was variably affected, but generally decreased as well. Conclusions Ulnar contact patterns were changed as a result of VV implant positioning using reverse-engineered DH implants, most notably on the medial aspect of the joint. Implant positioning plays a crucial role in producing contact patterns more like those observed in the native joint. Clinical relevance Recent clinical evidence reports nonsymmetrical ulnar wear after DHH. This work suggests that implant positioning is likely a contributing factor and that more exact implant positioning may lead to better clinical outcomes

    Structural and Financial Characteristics of U.S. Farms: 2001 Family Farm Report

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    Family farms vary widely in size and other characteristics, ranging from very small retirement and residential farms to establishments with sales in the millions of dollars. The farm typology developed by the Economic Research Service (ERS) categorizes farms into groups based primarily on occupation of the operator and sales class of the farm. The typology groups reflect operators' expectations from farming, position in the life cycle, and dependence on agriculture. The groups differ in their importance to the farm sector, product specialization, program participation, and dependence on farm income. These (and other) differences are discussed in this report.Agricultural Resource Management Study (ARMS), family farms, farm businesses, farm financial situation, farm operator household income, farm operators, farm structure, farm typology, female farm operators, government payments, spouses of farm operators, taxes, Agricultural Finance, Farm Management,

    Multimodal Imaging of Photoreceptor Structure in Choroideremia

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    Purpose Choroideremia is a progressive X-linked recessive dystrophy, characterized by degeneration of the retinal pigment epithelium (RPE), choroid, choriocapillaris, and photoreceptors. We examined photoreceptor structure in a series of subjects with choroideremia with particular attention to areas bordering atrophic lesions. Methods Twelve males with clinically-diagnosed choroideremia and confirmed hemizygous mutations in the CHM gene were examined. High-resolution images of the retina were obtained using spectral domain optical coherence tomography (SD-OCT) and both confocal and non-confocal split-detector adaptive optics scanning light ophthalmoscope (AOSLO) techniques. Results Eleven CHM gene mutations (3 novel) were identified; three subjects had the same mutation and one subject had two mutations. SD-OCT findings included interdigitation zone (IZ) attenuation or loss in 10/12 subjects, often in areas with intact ellipsoid zones; RPE thinning in all subjects; interlaminar bridges in the imaged areas of 10/12 subjects; and outer retinal tubulations (ORTs) in 10/12 subjects. Only split-detector AOSLO could reliably resolve cones near lesion borders, and such cones were abnormally heterogeneous in morphology, diameter and density. On split-detector imaging, the cone mosaic terminated sharply at lesion borders in 5/5 cases examined. Split-detector imaging detected remnant cone inner segments within ORTs, which were generally contiguous with a central patch of preserved retina. Conclusions Early IZ dropout and RPE thinning on SD-OCT are consistent with previously published results. Evidence of remnant cone inner segments within ORTs and the continuity of the ORTs with preserved retina suggests that these may represent an intermediate state of retinal degeneration prior to complete atrophy. Taken together, these results supports a model of choroideremia in which the RPE degenerates before photoreceptors

    Histopathological Analysis of Quails in the Trans-Pecos Ecoregion of Texas

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    Quail populations in Texas, USA, have declined over the past few decades due primarily to habitat loss. The role that parasites may play in such declines has been a recent topic of concern. To help address this question, we collected 12 scaled quail (Callipepla squamata), 8 Gambel’s quail (Callipepla gambelii), and 3 Montezuma quail (Cyrtonyx montezumae) from across the Trans-Pecos ecoregion of Texas via hunter harvest, funnel traps, and night netting. Quail samples were necropsied to determine the abundance of eyeworms (Oxyspirura petrowi). Histopathological analyses were conducted on quail eyeballs and periocular tissues to gain information on parasite-related tissue damage and document other pathogenic factors. We calculated mean abundances of Oxyspirura petrowi for sampled scaled (x̄ = 5.5, standard deviation [SD] = 2.5, x̃ = 3, n = 12), Gambel’s (x̄ = 6.4, SD = 4.2, x̃ = 1.5, n = 8), and Montezuma quail (x̄ = 13, SD = 1.5, x̃ = 13, n = 3). Host tissues exhibited immune responses (i.e., lymphocytic conjunctivitis and plasmacytic adenitis) to O. petrowi. The observed immune responses indicated relatively mild irritation within the ocular tissues. It has been speculated that such irritation to ocular tissues could negatively impact quail vision. This potential impact is worth noting because quails rely on keen vision to detect predators. Future research should focus on measuring the effects of O. petrowi infections on quail survival

    Whole genome sequencing-based mapping and candidate identification of mutations from fixed zebrafish tissue

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    As forward genetic screens in zebrafish become more common, the number of mutants that cannot be identified by gross morphology or through transgenic approaches, such as many nervous system defects, has also increased. Screening for these difficult-to-visualize phenotypes demands techniques such as whole-mount in situ hybridization (WISH) or antibody staining, which require tissue fixation. To date, fixed tissue has not been amenable for generating libraries for whole genome sequencing (WGS). Here, we describe a method for using genomic DNA from fixed tissue and a bioinformatics suite for WGS-based mapping of zebrafish mutants. We tested our protocol using two known zebrafish mutant alleles, gpr126st49 and egr2bfh227, both of which cause myelin defects. As further proof of concept we mapped a novel mutation, stl64, identified in a zebrafish WISH screen for myelination defects. We linked stl64 to chromosome 1 and identified a candidate nonsense mutation in the F-box and WD repeat domain containing 7 (fbxw7) gene. Importantly, stl64 mutants phenocopy previously described fbxw7vu56 mutants, and knockdown of fbxw7 in wild-type animals produced similar defects, demonstrating that stl64 disrupts fbxw7. Together, these data show that our mapping protocol can map and identify causative lesions in mutant screens that require tissue fixation for phenotypic analysis

    Grey matter volume differences in the left caudate nucleus of people who stutter.

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    The cause of stuttering has many theoretical explanations. A number of research groups have suggested changes in the volume and/or function of the striatum as a causal agent. Two recent studies in children and one in adults who stutter (AWS) report differences in striatal volume compared that seen in controls; however, the laterality and nature of this anatomical volume difference is not consistent across studies. The current study investigated whether a reduction in striatal grey matter volume, comparable to that seen in children who stutter (CWS), would be found in AWS. Such a finding would support claims that an anatomical striatal anomaly plays a causal role in stuttering. We used voxel-based morphometry to examine the structure of the striatum in a group of AWS and compared it to that in a group of matched adult control subjects. Results showed a statistically significant group difference for the left caudate nucleus, with smaller mean volume in the group of AWS. The caudate nucleus, one of three main structures within the striatum, is thought to be critical for the planning and modulation of movement sequencing. The difference in striatal volume found here aligns with theoretical accounts of stuttering, which suggest it is a motor control disorder that arises from deficient articulatory movement selection and sequencing. Whilst the current study provides further evidence of a striatal volume difference in stuttering at the group level compared to controls, the significant overlap between AWS and controls suggests this difference is unlikely to be diagnostic of stuttering
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