107 research outputs found
Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds
Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period
A Novel Structural Assessment Technique to Prevent Damaged FRP-Wrapped Concrete Bridge Piers from Collapse
Repairing deteriorated concrete bridge piers using externally wrapped fiber reinforced polymer (FRP) composites have been proven as an effective approach. This technique has also been applied to low-rise building structures. Failures in FRP-wrapped concrete structures may occur by flexural failures of critical sections or by debonding of FRP plate from the concrete substrate. Debonding in the FRP/adhesive/concrete interface region may cause a significant decrease in member capacity leading to a premature failure of the system. In this chapter, a novel structural assessment technique aiming at inspecting the near-surface FRP debonding and concrete cracking of damaged FRP-wrapped concrete bridge piers to prevent the structures from collapse is presented. In the first part of this chapter, failure mechanisms of FRP-wrapped concrete systems are briefly discussed. The second part of this chapter introduces a novel structural assessment technique in which far-field airborne radar is applied. In this development, emphasis is placed on inspection of debonding in glass FRP (GFRP)-wrapped concrete cylinders, while the technique is also applicable to beams and slabs with bonded GFRP composites. Physical radar measurements on laboratory specimens with structural damages were conducted and used for validating the technique. Processed experimental measurements have shown promising results for the future application of the technique. Finally, research findings and issues are summarized.National Science Foundation (U.S.) (Grant CMS-0324607)Lincoln Laborator
The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds
Most non-avian theropod dinosaurs are characterized by fearsome serrated teeth and sharp recurved claws. Interpretation of theropod predatory ecology is typically based on functional morphological analysis of these and other physical features. The notorious hypertrophied ‘killing claw’ on pedal digit (D) II of the maniraptoran theropod Deinonychus (Paraves: Dromaeosauridae) is hypothesized to have been a predatory adaptation for slashing or climbing, leading to the suggestion that Deinonychus and other dromaeosaurids were cursorial predators specialized for actively attacking and killing prey several times larger than themselves. However, this hypothesis is problematic as extant animals that possess similarly hypertrophied claws do not use them to slash or climb up prey. Here we offer an alternative interpretation: that the hypertrophied D-II claw of dromaeosaurids was functionally analogous to the enlarged talon also found on D-II of extant Accipitridae (hawks and eagles; one family of the birds commonly known as “raptors”). Here, the talon is used to maintain grip on prey of subequal body size to the predator, while the victim is pinned down by the body weight of the raptor and dismembered by the beak. The foot of Deinonychus exhibits morphology consistent with a grasping function, supportive of the prey immobilisation behavior model. Opposite morphological trends within Deinonychosauria (Dromaeosauridae + Troodontidae) are indicative of ecological separation. Placed in context of avian evolution, the grasping foot of Deinonychus and other terrestrial predatory paravians is hypothesized to have been an exaptation for the grasping foot of arboreal perching birds. Here we also describe “stability flapping”, a novel behaviour executed for positioning and stability during the initial stages of prey immobilisation, which may have been pivotal to the evolution of the flapping stroke. These findings overhaul our perception of predatory dinosaurs and highlight the role of exaptation in the evolution of novel structures and behaviours
Statistical strategies for avoiding false discoveries in metabolomics and related experiments
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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Neutron Radiography and Computed Tomography at Oak Ridge National Laboratory
The capability to perform neutron radiography and computed tomography is being developed at Oak Ridge National Laboratory. The facility will be located at the High Flux Isotope Reactor (HFIR), which has the highest steady state neutron flux of any reactor in the world. The Monte Carlo N-Particle transport code (MCNP), versions 4A and 4B, has been used extensively in the design phase of the facility to predict and optimize the operating characteristics, and to ensure the safety of personnel working in and around the blockhouse. Neutrons are quite penetrating in most engineering materials and can be useful to detect internal flaws and features. Hydrogen atoms, such as in a hydrocarbon fuel, lubricant or a metal hydride, are relatively opaque to neutron transmission. Thus, neutron based tomography or radiography is ideal to image their presence. The source flux also provides unparalleled flexibility for future upgrades, including real time radiography where dynamic processes can be observed. A novel tomography detector has been designed using optical fibers and digital technology to provide a large dynamic range for reconstructions. Film radiography is also available for high resolution imaging applications. This paper summarizes the results of the design phase of this facility and the potential benefits to science and industry
Tempest: Crew Exploration Vehicle Concept
41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
July 10-13, 2005, Tucson, AZ.Tempest is a reusable crew exploration vehicle (CEV) for transferring crew from the
Earth to the lunar surface and back. Tempest serves as a crew transfer module that supports
a 4-person crew for a mission duration of 18 days, which consists of 8 days total transit
duration and 10-day surface duration. Primary electrical power generation and on-orbit
maneuvering for Tempest is provided by an attached Power and Propulsion Module (PPM).
Hydrogen (H2)/oxygen (O2) fuel cells and a high energy-density matter (HEDM)/liquid
oxygen (LOX) propellant reaction control system (RCS) provide power and reaction control
respectively during Tempest’s separation from the PPM. Tempest is designed for a lifting
entry and is equipped with parachutes for a soft landing.
Tempest is part of an overall lunar transportation architecture. The 60,731 lbs
combination of Tempest and the PPM are launched atop the notional Centurion C-1 heavylift
launch vehicle (HLLV) and delivered to a 162 nmi, 28.5º circular orbit. After separating
from the C-1 upper stage, the Tempest/PPM autonomously rendezvous with Manticore, an
expendable trans-lunar injection (TLI) stage pre-positioned in the current orbit, and
transfer to a lunar trajectory. After entering a 54 nmi polar circular lunar orbit, the
Tempest/PPM separate from Manticore. Tempest separates from the PPM and is ferried
to/from the lunar surface by Artemis, a reusable lunar lander. Upon return from the lunar
surface, Tempest reconnects with the PPM, and the PPM provides the trans-earth injection
(TEI) burn required to return to low earth orbit (LEO). Prior to atmospheric entry,
Tempest separates from the PPM and subsequently executes a lifting entry trajectory.
Crushable thermal foam attached to the lower surface of Tempest serves as an ablative
thermal protection system (TPS) and the impact absorber of the parachute landing.
Details of the conceptual design process used for Tempest are included in this paper. The
disciplines used in the design include: configuration, aerodynamics, propulsion, trajectory,
mass properties, environmental control life support system (ECLSS), entry aeroheating and
TPS, terminal landing system (TLS), cost, operations, and reliability & safety. Each of these
disciplines was computed using a conceptual design tool similar to that used in industry.
These disciplines were then combined and optimized for the minimum gross weight of the
Tempest CEV. The total development cost including the design, development, testing and
evaluation (DDT&E) cost was determined to be 479 M FY’04. A summary of design disciplines as well
as the economic results are included
Cross-cultural adaptation of the work role functioning questionnaire to Spanish spoken in Spain
PURPOSE: The Work Role Functioning Questionnaire (WRFQ) is a tool developed in the United States to measure work disability and assess the perceived impact of health problems on worker ability to perform jobs. We translated and adapted the WRFQ to Spanish spoken in Spain and assessed preservation of its psychometric properties. METHODS: Cross-cultural adaptation of the WRFQ was performed following a systematic 5-step procedure: (1) direct translation, (2) synthesis, (3) back-translation, (4) consolidation by an expert committee and (5) pre-test. Psychometric properties were evaluated by administering the questionnaire to 40 patients with different cultural levels and health problems. Applicability, usability, readability and integrity of the WRFQ were assessed, together with its validity and reliability. RESULTS: Questionnaire translation, back translation and consolidation were carried out without relevant difficulties. Idiomatic issues requiring reformulation were found in the instructions, response options and in 2 items. Participants appreciated the applicability, usability, readability and integrity of the questionnaire. The results indicated good face and content validity. Internal consistency was satisfactory for all subscales (Cronbach's alpha between 0.88 and 0.96), except for social demands (Cronbach's alpha = 0.56). Test-retest reliability showed good stability, with intraclass correlation coefficients between 0.77 and 0.93 for all subscales. Construct validity was considered preserved based on the comparison of median scores for each patient group and subscale. CONCLUSIONS: Our results indicate the cross-cultural adaptation of the WRFQ to Spanish was satisfactory and preserved its psychometric properties, except for the subscale of social demands, whose internal consistency should be interpreted with caution.This project has been partially supported by a grant from the Fondo de Investigaciones Sanitarias (FIS: PI12/02556), Instituto de Salud Carlos III, Subdirección General de Evaluación y Fomento de la Investigación, Ministerio de Ciencia e Innovació
THE ROLE OF METAL-ION BINDING IN MODIFYING THE TOXIC EFFECTS OF SULPHUR DIOXIDE ON THE LICHEN UMBILICARIA MUHLENBERGII. II. 14C-FIXATION STUDIES
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