55 research outputs found
Investigation into the Genetic Provenance of Three Rare Plants with East-West Disjunction Patterns in Pennsylvania.
Rare plant conservation relies on an understanding of the natural history, biology and ecology, and real and potential threats to their populations to inform state regulations that serve to protect the species from extirpation. This work often involves extensive field surveys over several years to determine population sizes and whether those populations are seeing reductions in number of individuals necessary to maintain the genetic diversity within and between those populations. Species and populations with high genetic diversity are better equipped to withstand sudden changes to their habitats that derive from land use changes and changing climate. There are a variety of methods used to investigate population genetic diversity and next generation sequencing (NGS) methods allow for complete genomic coverage by analyzing single nucleotide polymorphisms (SNPs) and allowing for an estimation of population genetic parameters such as genetic variation (FST), the inbreeding coefficient (FIS), and heterozygosity (HO) (HE). Population genomic investigations of Baptisia australis, Chasmanthium latifolium, and Erigenia bulbosa, plant species at the edge of their ranges in Pennsylvania and disjunct distributions within the state were performed for this study. All three species exhibited lower than expected heterozygosity and, with the exception of Chasmanthium, high levels of inbreeding. This information was incorporated into conservation rank status assessments and climate change vulnerability indices using the NatureServe Conservation Status Rank Calculator and the Climate Change Vulnerability Index tools. As a result, state ranks for Chasmanthium and Erigenia require formally proposed changes to the Department of Conservation of Natural Resources. Likewise, management recommendations are given as guidance on the steps likely necessary to preserve and potentially increase the genetic diversity for all species. Through these investigations, a long-term partnership between the Pennsylvania Natural Heritage Program at Western Pennsylvania Conservancy and Bucknell University was developed through which a pipeline of undergraduate and graduate students were, and will be, trained in both field-based natural heritage methods and new, innovative ways address the conservation of rare plants in Pennsylvania and beyond
Lepidopteran Granivory Reduces Seed Counts in a Rare Species of Riparian Scour Prairies
In Pennsylvania Baptisia australis var. australis is found along only four waterways: the Allegheny River, Youghiogheny River, Clarion River, and Red Bank Creek. Because of its limited distribution and small number of extant populations, the species is considered state-threatened in Pennsylvania. In addition, the riparian prairie habitat that Pennsylvania Baptisia australis var. australis is restricted to is also in decline and considered vulnerable. Because of these conservation concerns, insights into the natural history of the taxon in the state is valuable and will inform conservation efforts. Field surveys and fruit collections along the Allegheny River and herbarium collections were used to investigate and document granivory in Pennsylvania Baptisia australis var. australis, a phenomenon recorded in other parts of the species\u27 range, but not previously reported on in Pennsylvania. Using a model of best fit, the number of seeds found in fruit was found to be significantly impacted by the presence of granivores. We also report that visual surveys of fruits in the field are found to be accurate assessments of the presence and potential impact of granivores. In turn, our results will inform the conservation and management of Baptisia australis var. australis populations in Pennsylvania and highlight the importance of field surveys in protecting threatened taxa
Time-to-effect guided pulmonary vein isolation utilizing the third-generation versus second generation cryoballoon: One year clinical success
Background: The second-generation cryoballoon (CB2) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging and reproducible clinical outcome data. The latest- -generation cryoballoon (CB3) incorporates a 40% shorter distal tip, thus allowing for an increased rate of PVI real-time signal recording and facilitating individualized ablation strategies taking the time-to- -effect (TTE) into account. However, whether this characteristic translates into favorable clinical success has not been evaluated yet. Herein was investigated 1-year clinical success after CB3 in comparison to CB2 based-PVI.
Methods: One hundred and ten consecutive patients with paroxysmal or short-standing persistent atrial fibrillation (AF) underwent CB2 (n = 55 patients) -or CB3 (n = 55 patients) -based PVI. The freeze-cycle duration was set to TTE + 120 s if TTE could be recorded, otherwise a fixed freeze-cycle duration of 180 s was applied.
Results: A total of 217/218 (99%, CB3) and 217/217 (100%, CB2) pulmonary veins (PV) were successfully isolated. The real-time PVI visualization rate was 69.2% (CB3) and 54.8% (CB2; p = 0.0392). The mean freeze-cycle duration was 194 ± 77 s (CB3) and 206 ± 85 s (CB2; p = 0.132), respectively. During a median follow-up of 409 days (interquartile range [IQR] 378–421, CB3) and 432 days (IQR 394–455, CB2) 73.6% (CB3) and 73.1% of patients (CB2) remained in stable sinus rhythm after a single procedure (p = 0.806).
Conclusions: A higher rate of real-time electrical PV recordings was seen using the CB3 as compared to CB2. There was no difference in 1-year clinical follow-up
Merkel cell carcinoma: Critical review with guidelines for multidisciplinary management
Merkel cell carcinoma (MCC) is a relatively rare cutaneous malignancy that occurs predominantly in the older white population. The incidence of MCC appears to have tripled during the past 20 years; an increase that is likely to continue because of the growing number of older Americans. The pathogenesis of MCC remains largely unknown. However, ultraviolet radiation and immunosuppression are likely to play a significant pathogenetic role. Many questions currently remain unanswered regarding the biologic behavior and optimal treatment of MCC. Large, prospective, randomized studies are not available and are unlikely to be performed because of the rarity of the disease. The objective of this review was to provide a comprehensive reference for MCC based on a critical evaluation of the current data. The authors investigated the importance of sentinel lymph node biopsy as a staging tool for MCC to assess the status of the regional lymph node basin and to determine the need for additional therapy to the lymph node basin. In an attempt to standardize prospective data collection with the intention to define prognostic indicators, the authors also present histopathologic profiles for primary MCC and sentinel lymph nodes. The controversies regarding the appropriate surgical approach to primary MCC, the use of adjuvant radiation therapy, and the effectiveness of adjuvant chemotherapy were examined critically. Finally, the authors have provided treatment guidelines based on the available evidence and their multidisciplinary experience. Cancer 2007. © 2007 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56047/1/22765_ftp.pd
High activity redox catalysts synthesized by chemical vapor impregnation
The use of precious metals in heterogeneous catalysis relies on the preparation of small nanoparticles that are stable under reaction conditions. To date, most conventional routes used to prepare noble metal nanoparticles have drawbacks related to surface contamination, particle agglomeration, and reproducibility restraints. We have prepared titania-supported palladium (Pd) and platinum (Pt) catalysts using a simplified vapor deposition technique termed chemical vapor impregnation (CVI) that can be performed in any standard chemical laboratory. These materials, composed of nanoparticles typically below 3 nm in size, show remarkable activity under mild conditions for oxidation and hydrogenation reactions of industrial importance. We demonstrate the preparation of bimetallic Pd–Pt homogeneous alloy nanoparticles by this new CVI method, which show synergistic effects in toluene oxidation. The versatility of our CVI methodology to be able to tailor the composition and morphology of supported nanoparticles in an easily accessible and scalable manner is further demonstrated by the synthesis of Pdshell–Aucore nanoparticles using CVI deposition of Pd onto preformed Au nanoparticles supported on titania (prepared by sol immobilization) in addition to the presence of monometallic Au and Pd nanoparticles
Severe Asthma Standard-of-Care Background Medication Reduction With Benralizumab: ANDHI in Practice Substudy
Background: The phase IIIb, randomized, parallel-group, placebo-controlled ANDHI double-blind (DB) study extended understanding of the efficacy of benralizumab for patients with severe eosinophilic asthma. Patients from ANDHI DB could join the 56-week ANDHI in Practice (IP) single-arm, open-label extension substudy. Objective: Assess potential for standard-of-care background medication reductions while maintaining asthma control with benralizumab. Methods: Following ANDHI DB completion, eligible adults were enrolled in ANDHI IP. After an 8-week run-in with benralizumab, there were 5 visits to potentially reduce background asthma medications for patients achieving and maintaining protocol-defined asthma control with benralizumab. Main outcome measures for non-oral corticosteroid (OCS)-dependent patients were the proportions with at least 1 background medication reduction (ie, lower inhaled corticosteroid dose, background medication discontinuation) and the number of adapted Global Initiative for Asthma (GINA) step reductions at end of treatment (EOT). Main outcomes for OCS-dependent patients were reductions in daily OCS dosage and proportion achieving OCS dosage of 5 mg or lower at EOT. Results: For non-OCS-dependent patients, 53.3% (n = 208 of 390) achieved at least 1 background medication reduction, increasing to 72.6% (n = 130 of 179) for patients who maintained protocol-defined asthma control at EOT. A total of 41.9% (n = 163 of 389) achieved at least 1 adapted GINA step reduction, increasing to 61.8% (n = 110 of 178) for patients with protocol-defined EOT asthma control. At ANDHI IP baseline, OCS dosages were 5 mg or lower for 40.4% (n = 40 of 99) of OCS-dependent patients. Of OCS-dependent patients, 50.5% (n = 50 of 99) eliminated OCS and 74.7% (n = 74 of 99) achieved dosages of 5 mg or lower at EOT. Conclusions: These findings demonstrate benralizumab's ability to improve asthma control, thereby allowing background medication reduction
Search of the Orion spur for continuous gravitational waves using a loosely coherent algorithm on data from LIGO interferometers
We report results of a wideband search for periodic gravitational waves from isolated neutron stars within the Orion spur towards both the inner and outer regions of our Galaxy. As gravitational waves interact very weakly with matter, the search is unimpeded by dust and concentrations of stars. One search disk (A) is 6.87° in diameter and centered on 20h10m54.71s+33°33′25.29′′, and the other (B) is 7.45° in diameter and centered on 8h35m20.61s-46°49′25.151′′. We explored the frequency range of 50-1500 Hz and frequency derivative from 0 to -5×10-9 Hz/s. A multistage, loosely coherent search program allowed probing more deeply than before in these two regions, while increasing coherence length with every stage. Rigorous follow-up parameters have winnowed the initial coincidence set to only 70 candidates, to be examined manually. None of those 70 candidates proved to be consistent with an isolated gravitational-wave emitter, and 95% confidence level upper limits were placed on continuous-wave strain amplitudes. Near 169 Hz we achieve our lowest 95% C.L. upper limit on the worst-case linearly polarized strain amplitude h0 of 6.3×10-25, while at the high end of our frequency range we achieve a worst-case upper limit of 3.4×10-24 for all polarizations and sky locations. © 2016 American Physical Society
Spatial patterns of large African cats : a large-scale study on density, home range size, and home range overlap of lions Panthera leo and leopards Panthera pardus
SUPPORTING INFORMATION : APPENDIX S1. Site information. APPENDIX S2. Intuitive explanation of the autocorrelated kernel density estimator. APPENDIX S3. Sources of density data. APPENDIX S4. Mathematical modifications of Jetz et al.’s (2014) overlap equation. APPENDIX S5. Lion pride size data.1. Spatial patterns of and competition for resources by territorial carnivores are
typically explained by two hypotheses: 1) the territorial defence hypothesis
and 2) the searching efficiency hypothesis.
2. According to the territorial defence hypothesis, when food resources are abundant,
carnivore densities will be high and home ranges small. In addition,
carnivores can maximise their necessary energy intake with minimal territorial
defence. At medium resource levels, larger ranges will be needed, and it will
become more economically beneficial to defend resources against a lower
density of competitors. At low resource levels, carnivore densities will be low
and home ranges large, but resources will be too scarce to make it beneficial
to defend such large territories. Thus, home range overlap will be minimal
at intermediate carnivore densities.
3. According to the searching efficiency hypothesis, there is a cost to knowing
a home range. Larger areas are harder to learn and easier to forget, so carnivores
constantly need to keep their cognitive map updated by regularly
revisiting parts of their home ranges. Consequently, when resources are scarce,
carnivores require larger home ranges to acquire sufficient food. These larger
home ranges lead to more overlap among individuals’ ranges, so that overlap in home ranges is largest when food availability is the lowest. Since conspecific
density is low when food availability is low, this hypothesis predicts that
overlap is largest when densities are the lowest.
4. We measured home range overlap and used a novel method to compare
intraspecific home range overlaps for lions Panthera leo (n = 149) and leopards
Panthera pardus (n = 111) in Africa. We estimated home range sizes
from telemetry location data and gathered carnivore density data from the
literature.
5. Our results did not support the territorial defence hypothesis for either species.
Lion prides increased their home range overlap at conspecific lower
densities whereas leopards did not. Lion pride changes in overlap were primarily
due to increases in group size at lower densities. By contrast, the
unique dispersal strategies of leopards led to reduced overlap at lower densities.
However, when human-caused
mortality was higher, leopards increased
their home range overlap. Although lions and leopards are territorial, their
territorial behaviour was less important than the acquisition of food in determining
their space use. Such information is crucial for the future conservation
of these two iconic African carnivores.The Natural Sciences and Engineering Research Council of Canada and a Hugh Kelly Fellowship from Rhodes University, Grahamstown, SA.https://onlinelibrary.wiley.com/journal/13652907am2024Centre for Wildlife ManagementMammal Research InstituteZoology and EntomologySDG-15:Life on lan
Search of the Orion spur for continuous gravitational waves using a loosely coherent algorithm on data from LIGO interferometers
We report results of a wideband search for periodic gravitational waves from isolated neutron stars within the Orion spur towards both the inner and outer regions of our Galaxy. As gravitational waves interact very weakly with matter, the search is unimpeded by dust and concentrations of stars. One search disk (A) is 6.87° in diameter and centered on 20[superscript h]10[superscript m]54.71[superscript s] + 33°33[superscript ′]25.29[superscript ′′], and the other (B) is 7.45° in diameter and centered on 8[superscript h]35[superscript m]20.61[superscript s] - 46°49[superscript ′]25.151[superscript ′′]. We explored the frequency range of 50–1500 Hz and frequency derivative from 0 to -5 × 10[superscript -9] Hz/s. A multistage, loosely coherent search program allowed probing more deeply than before in these two regions, while increasing coherence length with every stage. Rigorous follow-up parameters have winnowed the initial coincidence set to only 70 candidates, to be examined manually. None of those 70 candidates proved to be consistent with an isolated gravitational-wave emitter, and 95% confidence level upper limits were placed on continuous-wave strain amplitudes. Near 169 Hz we achieve our lowest 95% C.L. upper limit on the worst-case linearly polarized strain amplitude h[subscript 0] of 6.3 × 10[superscript -25], while at the high end of our frequency range we achieve a worst-case upper limit of 3.4 × 10[superscript -24] for all polarizations and sky locations.National Science Foundation (U.S.)United States. National Aeronautics and Space AdministrationCarnegie TrustDavid & Lucile Packard FoundationAlfred P. Sloan Foundatio
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10–500 s in a frequency band of 40–1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10[superscript -5] and 9.4×10[superscript -4] Mpc[superscript -3] yr[superscript -1] at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves.Carnegie TrustDavid & Lucile Packard FoundationAlfred P. Sloan FoundationNational Science Foundation (U.S.
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