2,554 research outputs found
Comprehensive rotorcraft analysis methods
The development and application of comprehensive rotorcraft analysis methods in the field of rotorcraft technology are described. These large scale analyses and the resulting computer programs are intended to treat the complex aeromechanical phenomena that describe the behavior of rotorcraft. They may be used to predict rotor aerodynamics, acoustic, performance, stability and control, handling qualities, loads and vibrations, structures, dynamics, and aeroelastic stability characteristics for a variety of applications including research, preliminary and detail design, and evaluation and treatment of field problems. The principal comprehensive methods developed or under development in recent years and generally available to the rotorcraft community because of US Army Aviation Research and Technology Activity (ARTA) sponsorship of all or part of the software systems are the Rotorcraft Flight Simulation (C81), Dynamic System Coupler (DYSCO), Coupled Rotor/Airframe Vibration Analysis Program (SIMVIB), Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD), General Rotorcraft Aeromechanical Stability Program (GRASP), and Second Generation Comprehensive Helicopter Analysis System (2GCHAS)
Licensed control does not reduce local Cormorant Phalacrocorax carbo population size in winter
Cormorants Phalacrocorax carbo have increased on European freshwaters, creating conflicts with fishing interests. As a result, control measures have been implemented in several countries, although their effect on the English population has yet to be determined. Wetland Bird Survey data was used to derive population growth rates (PGR) of non-coastal Cormorant populations in England. PGR was analysed in relation to control intensity at different scales (5- to 30-km radius) from 2001 to 2009 in order to determine (1) the extent to which control intensity (proportion of the local population shot per winter) was associated with site-level population change, and (2) whether potential effects of control intensity were evident on Special Protection Areas (SPAs). There were no clear differences in PGR when comparing sites which had experienced control versus sites where control had never been carried out. The few significant relationships between control intensity and Cormorant PGR detected were mostly positive, i.e. population growth was associated with higher control intensity. Control intensity was not related to Cormorant numbers in SPAs. Positive associations with control may arise because control is reactive, or because non-lethal effects cause greater dispersal of Cormorants. These results provide no evidence that Cormorant removal at local scales is having an effect on longer term (i.e. year-to-year) population size at a site level. They also suggest that control measures have not affected national population trends, although a better understanding of site use and movements of individual Cormorants needs to be developed at smaller scales (including those due to disturbance caused by control measures) to more fully understand processes at larger scales. Further research is also needed into the extent to which lethal and non-lethal effects of control on Cormorants are having the desired impact on predation rates of fish, and so help resolve the conflict between Cormorants and fisheries.</p
Improved population trends of Great Cormorants Phalacrocorax carbo in England and Wales for effective management of a protected species at the centre of a human-wildlife conflict.
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Seshat: The Global History Databank
The vast amount of knowledge about past human societies has not been systematically organized and, therefore, remains inaccessible for empirically testing theories about cultural evolution and historical dynamics. For example, what evolutionary mechanisms were involved in the transition from the small-scale, uncentralized societies, in which humans lived 10,000 years ago, to the large-scale societies with an extensive division of labor, great differentials in wealth and power, and elaborate governance structures of today? Why do modern states sometimes fail to meet the basic needs of their populations? Why do economies decline, or fail to grow? In this article, we describe the structure and uses of a massive databank of historical and archaeological information, Seshat: The Global History Databank. The data that we are currently entering in Seshat will allow us and others to test theories explaining how modern societies evolved from ancestral ones, and why modern societies vary so much in their capacity to satisfy their members’ basic human needsPeer reviewedFinal Published versio
Distributed Subnetworks of Depression Defined by Direct Intracranial Neurophysiology
Major depressive disorder is a common and disabling disorder with high rates of treatment resistance. Evidence suggests it is characterized by distributed network dysfunction that may be variable across patients, challenging the identification of quantitative biological substrates. We carried out this study to determine whether application of a novel computational approach to a large sample of high spatiotemporal resolution direct neural recordings in humans could unlock the functional organization and coordinated activity patterns of depression networks. This group level analysis of depression networks from heterogenous intracranial recordings was possible due to application of a correlational model-based method for inferring whole-brain neural activity. We then applied a network framework to discover brain dynamics across this model that could classify depression. We found a highly distributed pattern of neural activity and connectivity across cortical and subcortical structures that was present in the majority of depressed subjects. Furthermore, we found that this depression signature consisted of two subnetworks across individuals. The first was characterized by left temporal lobe hypoconnectivity and pathological beta activity. The second was characterized by a hypoactive, but hyperconnected left frontal cortex. These findings have applications toward personalization of therapy
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High Prevalence of Multidrug-Tolerant Bacteria and Associated Antimicrobial Resistance Genes Isolated from Ornamental Fish and Their Carriage Water
Background: Antimicrobials are used to directly control bacterial infections in pet (ornamental) fish and are routinely added to the water these fish are shipped in to suppress the growth of potential pathogens during transport. Methodology/Principal Findings: To assess the potential effects of this sustained selection pressure, 127 Aeromonas spp. isolated from warm and cold water ornamental fish species were screened for tolerance to 34 antimicrobials. Representative isolates were also examined for the presence of 54 resistance genes by a combination of miniaturized microarray and conventional PCR. Forty-seven of 94 Aeromonas spp. isolates recovered from tropical ornamental fish and their carriage water were tolerant to >= 15 antibiotics, representing seven or more different classes of antimicrobial. The quinolone and fluoroquinolone resistance gene, qnrS2, was detected at high frequency (37% tested recent isolates were positive by PCR). Class 1 integrons, IncA/C broad host range plasmids and a range of other antibiotic resistance genes, including floR, blaTEM21, tet(A), tet(D), tet(E), qacE2, sul1, and a number of different dihydrofolate reductase and aminoglycoside transferase coding genes were also detected in carriage water samples and bacterial isolates. Conclusions: These data suggest that ornamental fish and their carriage water act as a reservoir for both multi-resistant bacteria and resistance genes
Determinants and effects of sexual exploitation among female students of tertiary institutions in Rivers State
Background: Labor induction methods are continuously evolving to ensure safer and more effective outcomes for both mother and neonate. The present study aimed to assess the effectiveness and safety of combined use of misoprostol with intracervical catheter for labor induction.
Methods: This single-blinded, parallel-group randomized control trial conducted at Shaheed Suhrawardy Medical College, Dhaka, Bangladesh, included 200 women with term gestation and Bishop score ≤6. Participants were divided into two groups: the intervention group (group B) received misoprostol juice and Foley’s catheter, while the control group (group A) received misoprostol in the posterior fornix.
Results: In Group A, 58% had vaginal deliveries, while in Group B, 65% had vaginal deliveries. Group B experienced a longer mean length of labor in the 1st stage (13.25±1.095) compared to Group A (12.98±1.982, p=0.008). The 3rd stage was shorter for Group B (10.00±0.000) than Group A (12.02±2.469, p<0.001). The most common induction reason was labor pain with an unfavorable cervix (31 in Group A and 33 in Group B). Group B had a higher percentage of inductions at less than 12 hours and a lower percentage at more than 24 hours. Neonatal outcomes were generally better for Group B. The Cox regression hazard model showed a lower likelihood of positive outcomes in Group B (hazard ratio 0.337, 95% CI 0.243-0.469, p=0.000), indicating a statistically significant difference between the groups.
Conclusions: The combined use of misoprostol with Foley’s catheter for labor induction is safe and effective, resulting in shorter labor duration and higher rates of vaginal delivery compared to misoprostol alone
Population genomics of domestic and wild yeasts
The natural genetics of an organism is determined by the distribution of sequences of its genome. Here we present one- to four-fold, with some deeper, coverage of the genome sequences of over seventy isolates of the domesticated baker's yeast, _Saccharomyces cerevisiae_, and its closest relative, the wild _S. paradoxus_, which has never been associated with human activity. These were collected from numerous geographic locations and sources (including wild, clinical, baking, wine, laboratory and food spoilage). These sequences provide an unprecedented view of the population structure, natural (and artificial) selection and genome evolution in these species. Variation in gene content, SNPs, indels, copy numbers and transposable elements provide insights into the evolution of different lineages. Phenotypic variation broadly correlates with global genome-wide phylogenetic relationships however there is no correlation with source. _S. paradoxus_ populations are well delineated along geographic boundaries while the variation among worldwide _S. cerevisiae_ isolates show less differentiation and is comparable to a single _S. paradoxus_ population. Rather than one or two domestication events leading to the extant baker's yeasts, the population structure of _S. cerevisiae_ shows a few well defined geographically isolated lineages and many different mosaics of these lineages, supporting the notion that human influence provided the opportunity for outbreeding and production of new combinations of pre-existing variation
An Analysis of Public Attitudes Toward the Insanity Defense
Results from a public opinion survey of knowledge, attitudes, and support for the insanity defense indicate that people dislike the insanity defense for both retributive and utilitarian reasons: they want insane law-breakers punished, and they believe that insanity defense procedures fail to protect the public. However, people vastly overestimate the use and success of the insanity plea. Several attitudinal and demographic variables that other researchers have found to be associated with people\u27s support for the death penalty and perceptions of criminal sentencing are also related to support for the insanity defense. Implications for public policy are discussed
Biochemical adaptations of the retina and retinal pigment epithelium support a metabolic ecosystem in the vertebrate eye
Here we report multiple lines of evidence for a comprehensive model of energy metabolism in the vertebrate eye. Metabolic flux, locations of key enzymes, and our finding that glucose enters mouse and zebrafish retinas mostly through photoreceptors support a conceptually new model for retinal metabolism. In this model, glucose from the choroidal blood passes through the retinal pigment epithelium to the retina where photoreceptors convert it to lactate. Photoreceptors then export the lactate as fuel for the retinal pigment epithelium and for neighboring Mu ̈ ller glial cells. We used human retinal epithelial cells to show that lactate can suppress consumption of glucose by the retinal pigment epithelium. Suppression of glucose consumption in the retinal pigment epithelium can increase the amount of glucose that reaches the retina. This framework for understanding metabolic relationships in the vertebrate retina provides new insights into the underlying causes of retinal disease and age-related vision loss
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