4,457 research outputs found
A catch-free stock assessment model with application to goliath grouper (Epinephelus itajara) off southern Florida
Many modern stock assessment methods provide the machinery for determining the status of a stock in relation to certain reference points and for estimating how quickly a stock can be rebuilt. However, these methods typically require catch data, which are not always available. We introduce a model-based framework for estimating reference points, stock status, and recovery times in situations where catch data and other measures of absolute abundance are unavailable. The specif ic estimator developed is essentially an age-structured production model recast in terms relative to pre-exploitation levels. A Bayesian estimation scheme is adopted to allow the incorporation of pertinent auxiliary information such as might be obtained from meta-analyses of similar stocks or anecdotal observations. The approach is applied to the population of goliath grouper (Epinephelus itajara) off southern Florida, for which there are three indices of relative abundance but no reliable catch data. The results confirm anecdotal accounts of a marked decline in abundance during the 1980s followed by a substantial increase after the harvest of goliath grouper was banned in 1990. The ban appears to have reduced fishing pressure to between 10% and 50% of the levels observed during the 1980s. Nevertheless, the predicted fishing mortality rate under the ban appears to remain substantial, perhaps owing to illegal harvest and depth-related release mortality. As a result, the base model predicts that there is less than a 40% chance that the spawning biomass will recover to a level that would produce a 50% spawning potential ratio
Evidence on the determinants and economic consequences of delegated monitoring
We investigate delegated monitoring by examining the determinants and effects of including cross-acceleration provisions in public debt contracts. We find that cross-acceleration provision use depends on borrowers' going concern relative to liquidation values, debt repayment structures, credit quality, and financial reporting quality. This suggests that the use of cross-acceleration provisions increases when the costs of cascading defaults are lower, the conflicts between creditor classes are higher, and the benefits of delegating monitoring to banks are higher. We also find a lower interest rate on public debt contracts with cross-acceleration provisions, but the rate reduction depends on borrowers' financial reporting quality
An indirect method to assess the energy expenditure of manual labourers in situ
The aim of ergonomics is to identify any incompatibility between worker capabilities and the demands of their job. It is therefore desirable that in a developing country such as South Africa we have some basic, yet valid and usable means of measuring worker responses to physically demanding manual tasks. Extensive ergonomic research has been conducted in the controlled environment of laboratories around the globe, but only a limited number of investigations have been conducted in the workplace. This is due to the impossibility of controlling the extraneous factors such as the environment and changing workloads while assessing worker responses, plus the impracticality of using hi-tech equipment under difficult conditions on unsophisticated workers. The likelihood of obtaining ‘natural’ responses thereby is low. The focus of this study was to establish a less invasive means of assessing the physiological responses (specifically energy expenditure) of manual labourers working in the field. Twenty-three forestry stackers were assessed. Heart-rate responses were recorded during a full shift, after which the workers participated in a submaximal incremental step test. Subjects were fitted with a gas analyser, and heart rate and oxygen consumption responses were measured throughout the 12-min test. These data were used to establish a regression equation based on the relationship between heart rate and oxygen consumption (r² = 0.49; r = 0.69). Using this equation (y=0.26x – 6.42), one can measure heart rate in the field and predict the energy cost of manual tasks
Cardiac responses under diverse combinations of marching speed and backpack load
Thirty seasoned foot-soldiers were exposed to a total of 16 combinations of marching speed and backpack load, each soldier experiencing 8 of the combinations between 3.5km.h-1 with a 20kg load and 6.5km.h-1 with a 65kg load. Detailed physiological analyses were conducted, of which the heart rate responses are reported here. Steady state was achieved with all combinations under 5.5km.h-1 speed and 35kg load. Excessively elevated heart rates were elicited by all loads over 20kg at 6.5km.h-1 marching speed; by loads over 35kg at 5.5km.h-1 marching speed and by the 65kg load even at 4.5km.h-1 marching speed
Damage of TWIP steels for automotive application
International audienceUltra high strength Fe-Mn-C austenitic steels with low Stacking Fault Energy (SFE) have been studied for more than fifty years [1]. They offer a great potential for reducing automotive body weight through their formability and their high mechanical properties. Tensile strength levels higher than 1000 MPa in combination with a high ductility (>50%) are reached by the optimization of the Twinning Induced Plasticity (TWIP) effect and the control of the microstructure
The widely used antimicrobial triclosan induces high levels of antibiotic tolerance in vitro and reduces antibiotic efficacy up to 100-fold in vivo
Moral injury in healthcare professionals: A scoping review and discussion
Moral injury emerged in the healthcare discussion quite recently because of the difficulties and challenges healthcare workers and healthcare systems face in the context of the COVID-19 pandemic. Moral injury involves a deep emotional wound and is unique to those who bear witness to intense human suffering and cruelty. This article aims to synthesise the very limited evidence from empirical studies on moral injury and to discuss a better understanding of the concept of moral injury, its importance in the healthcare context and its relation to the well-known concept of moral distress. A scoping literature review design was used to support the discussion. Systematic literature searches conducted in April 2020 in two electronic databases, PubMed/Medline and PsychInfo, produced 2044 hits but only a handful of empirical papers, from which seven well-focused articles were identified. The concept of moral injury was considered under other concepts as well such as stress of conscience, regrets for ethical situation, moral distress and ethical suffering, guilt without fault, and existential suffering with inflicting pain. Nurses had witnessed these difficult ethical situations when faced with unnecessary patient suffering and a feeling of not doing enough. Some cases of moral distress may turn into moral residue and end in moral injury with time, and in certain circumstances and contexts. The association between these concepts needs further investigation and confirmation through empirical studies; in particular, where to draw the line as to when moral distress turns into moral injury, leading to severe consequences. Given the very limited research on moral injury, discussion of moral injury in the context of the duty to care, for example, in this pandemic settings and similar situations warrants some consideration
The person-based development and realist evaluation of a summary report for GP consultations
Background: Use of telephone, video and e-consultations is increasing. These can make consultations more transactional. This study aimed to develop a complex intervention to address patients’ concerns more comprehensively in general practice and test the feasibility of this in a cluster-randomised framework.
The complex intervention used two technologies: a patient-completed pre-consultation form used at consultation opening and a doctor-provided summary report provided at consultation closure. This paper reports on the development and realist evaluation of the summary report.
Methods: A person-based approach was used to develop the summary report. An electronic protocol was designed to automatically generate the report after GPs complete a clinical template in the patient record. This was tested with 45 patients in 3 rounds each, with iterative adjustments made based on feedback after each round.
Subsequently, an intervention incorporating the pre-consultation form with the summary report was then tested in a cluster-randomised framework with 30 patients per practice in six practices: four randomised to intervention, and two to control. An embedded realist evaluation was carried out. The main feasibility study results are reported elsewhere.
Results: Intervention Development: 15 patients were recruited per practice. Eight patients and six GPs were interviewed and 18 changes made. The summary report improved substantially; GPs and patients in the final practice were more satisfied with the report than the first practice.
Realist evaluation: The summary was most useful for consultations when safety-netting advice was important or with multiple complex follow-up steps in patients who have difficulty remembering or communicating. It generated greater clarity on the follow-up and greater patient empowerment and reassurance.
Conclusions: The person-based approach was successful. The summary report creates clarity, empowerment and reassurance in certain consultations and patients. As it takes a few minutes per patient, GPs prefer to select patients who will benefit most
Hedgehog signal transduction proteins: contacts of the Fused kinase and Ci transcription factor with the Kinesin-related protein Costal2
BACKGROUND: Hedgehog signaling proteins play important roles in development by controlling growth and patterning in various animals including Drosophila and mammals. Hedgehog signaling triggers changes in responsive cells through a novel transduction mechanism that ultimately controls the transcription of specific target genes via the activity of zinc finger transcription factors of the Cubitus interruptus /GLI family. In flies, key Hedgehog signal transduction components have been identified including the kinesin-related protein Costal2, the serinethreonine kinase Fused, and the PEST-containing protein Suppressor of Fused. These proteins control Cubitus interruptus cleavage, nucleo-cytoplasmic localization and activation. In fly embryos, Costal2, Fused, Suppressor of Fused and Cubitus interruptus are associated in at least one cytoplasmic complex, which interacts with the microtubules in a Hedgehog-dependent manner. RESULTS: Here we identified and mapped direct interactions between Cos2, Fu, and Ci using an in vitro affinity assay and the yeast two-hybrid system. CONCLUSIONS: Our results provide new insights into the possible mechanism of the cytosolic steps of Hedgehog transduction
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