1,075 research outputs found
Seabird Bycatch in Pelagic Longline Fisheries Is Grossly Underestimated when Using Only Haul Data
Hundreds of thousands of seabirds are killed each year as bycatch in longline fisheries. Seabirds are predominantly caught during line setting but bycatch is generally recorded during line hauling, many hours after birds are caught. Bird loss during this interval may lead to inaccurate bycatch information. In this 15 year study, seabird bycatch was recorded during both line setting and line hauling from four fishing regions: Indian Ocean, Southern Ocean, Coral Sea and central Pacific Ocean. Over 43,000 albatrosses, petrels and skuas representing over 25 species were counted during line setting of which almost 6,000 seabirds attempted to take the bait. Bait-taking interactions were placed into one of four categories. (i) The majority (57%) of bait-taking attempts were “unsuccessful” involving seabirds that did not take the bait nor get caught or hooked. (ii) One-third of attempts were “successful” with seabirds removing the bait while not getting caught. (iii) One-hundred and seventy-six seabirds (3% of attempts) were observed being “caught” during line setting, with three albatross species – Laysan (Phoebastria immutabilis), black-footed (P. nigripes) and black-browed (Thalassarche melanophrys)– dominating this category. However, of these, only 85 (48%) seabird carcasses were retrieved during line hauling. Most caught seabirds were hooked through the bill. (iv) The remainder of seabird-bait interactions (7%) was not clearly observed, but likely involved more “caught” seabirds. Bait taking attempts and percentage outcome (e.g. successful, caught) varied between seabird species and was not always related to species abundance around fishing vessels. Using only haul data to calculate seabird bycatch grossly underestimates actual bycatch levels, with the level of seabird bycatch from pelagic longline fishing possibly double what was previously thought
Transition-Metal-Free Homopolymerization of Pyrrolo[2,3-d:5,4-d′]bisthiazoles via Nucleophilic Aromatic Substitution
Novel methods to synthesize electron-deficient π-conjugated polymers utilizing transition-metal-free coupling reactions for the use of nonfunctionalized monomers are attractive due to their improved atom economy and environmental prospective. Herein we describe the use of iPrMgCl·LiCl complex to afford thiazole-based conjugated polymers in the absence of any transition metal catalyst, that enables access to well-defined polymers with good molecular weights. The mechanistically distinct polymerizations proceeded via nucleophilic aromatic substitution (SNAr) reaction supported by density functional theory (DFT) calculations. This work demonstrates the first example of fully conjugated thiazole-based aromatic homopolymers without the need of any transition metal catalyst
Determining the Role of IL-4 Induced Neuroinflammation in Microglial Activity and Amyloid-ß Using BV2 Microglial Cells and APP/PS1 Transgenic Mice
Background
Microglia are considered the resident immune cells of the central nervous system (CNS). In response to harmful stimuli, an inflammatory reaction ensues in which microglia are activated in a sequenced spectrum of pro- and antiinflammatory phenotypes that are akin to the well-characterized polarization states of peripheral macrophages. A “classically” activated M1 phenotype is known to eradicate toxicity. The transition to an “alternatively” activated M2 phenotype encompasses neuroprotection and repair. In recent years, inflammation has been considered an accompanying pathology in response to the accumulation of extracellular amyloid-β (Aβ) in Alzheimer’s disease (AD). This study aimed to drive an M2a-biased immune phenotype with IL-4 in vitro and in vivo and to determine the subsequent effects on microglial activation and Aβ pathology. Methods
In vitro, exogenous IL-4 was applied to BV2 microglial cell cultures to evaluate the temporal progression of microglial responses. In vivo, intracranial injections of an adeno-associate-virus (AAV) viral vector were performed to assess long-term expression of IL-4 in the frontal cortex and hippocampus of Aβ-depositing, APP/PS1 transgenic mice. Quantitative real-time PCR was used to assess the fold change in expression of biomarkers representing each of the microglial phenotypes in both the animal tissue and the BV2 cells. ELISAs quantified IL-4 expression and Aβ levels. Histological staining permitted quantification of microglial and astrocytic activity. Results
Both in vitro and in vivo models showed an enhanced M2a phenotype, and the in vivo model revealed a trend toward a decreased trend in Aβ deposition. Conclusions
In summary, this study offers insight into the therapeutic potential of microglial immune response in AD
Defining and assessing spiritual health : a comparative study among 13- to 15-year-old pupils attending secular schools, Anglican schools, and private Christian schools in England and Wales
This article argues that the nation's commitment to young people involves proper concern for their physical health, their psychological health, and their spiritual health. In this context the notion of spiritual health is clarified by a critique of John Fisher's model of spiritual health. Fisher developed a relational model of spiritual health, which defines good spiritual health in terms of an individual's relationship to four domains: the personal, the communal, the environmental, and the transcendental. In the present analysis, we make comparisons between pupils educated in three types of schools: publicly funded schools without religious foundation, publicly funded schools with an Anglican foundation, and new independent Christian schools (not publicly funded). Our findings draw attention to significant differences in the levels of spiritual health experienced by pupils within these three types of schools
Measuring Future Time Perspective across Adulthood: Development and Evaluation of a Brief Multidimensional Questionnaire.
PURPOSE OF THE STUDY:
Despite calls for the consideration of future time perspective (FTP) as a multidimensional construct, mostly unidimensional measurement instruments have been used. This study had two objectives: (a) to develop a brief multidimensional questionnaire for assessing FTP in adulthood and evaluate its psychometric properties; and (b) to examine age associations and age-group differences of the dimensions of FTP.
DESIGN AND METHODS:
Data were collected from 625 community-residing adults between the ages of 18 and 93, representing young, middle-aged, and older adults. The psychometric evaluation involved exploratory factor analyses (EFA) and confirmatory FA (CFA), reliability and validity analyses, and measurement invariance testing. Zero-order and partial correlations were used to examine the association of the dimensions of FTP with age, and multivariate analysis of variance was used to examine age-group differences.
RESULTS:
EFA and CFA supported a three-factor solution: Future as Open, Future as Limited, and Future as Ambiguous. Metric measurement invariance for this factor structure was confirmed across the three age groups. Reliability and validity analyses provided evidence of sound psychometric properties of the brief questionnaire. Age was negatively associated with Future as Open and positively associated with Future as Limited. Young adults exhibited significantly greater ambiguity toward the future than middle-aged or older adults.
IMPLICATIONS:
This study provides evidence in support of the psychometric properties of a new brief multidimensional FTP scale. It also provides evidence for a pattern of age associations and age-group differences consistent with life-span developmental theory
A common neural system mediating two different forms of social judgement
Background: A wide range of neuropsychiatric conditions, including schizophrenia and autistic spectrum disorder (ASD), are associated with impairments in social function. Previous studies have shown that individuals with schizophrenia and ASD have deficits in making a wide range of social judgements from faces, including decisions related to threat (such as judgements of approachability) and decisions not related to physical threat (such as judgements of intelligence). We have investigated healthy control participants to see whether there is a common neural system activated during such social decisions, on the basis that deficits in this system may contribute to the impairments seen in these disorders. Method: We investigated the neural basis of social decision making during judgements of approachability and intelligence from faces in 24 healthy participants using functional magnetic resonance imaging (fMRI). We used conjunction analysis to identify common brain regions activated during both tasks. Results: Activation of the amygdala, medial prefrontal cortex, inferior prefrontal cortex and cerebellum was seen during performance of both social tasks, compared to simple gender judgements from the same stimuli. Task-specific activations were present in the dorsolateral prefrontal cortex in the intelligence task and in the inferior and middle temporal cortex in the approachability task. Conclusions: The present study identified a common network of brain regions activated during the performance of two different forms of social judgement from faces. Dysfunction of this network is likely to contribute to the broad-ranging deficits in social function seen in psychiatric disorders such as schizophrenia and ASD
Recommended from our members
The valuation of guaranteed lifelong withdrawal benefit options in variable annuity contracts and the impact of mortality risk
n light of the growing importance of the variable annuities market, in this paper we introduce a theoretical model for the pricing and valuation of guaranteed lifelong withdrawal benefit (GLWB) options embedded in variable annuity products. As the name suggests, this option offers a lifelong withdrawal guarantee; therefore, there is no limit on the total amount that is withdrawn over the term of the policy because if the account value becomes zero while the insured is still alive, he or she continues to receive the guaranteed amount annually until death. Any remaining account value at the time of death is paid to the beneficiary as a death benefit. We offer a specific framework to value the GLWB option in a market-consistent manner under the hypothesis of a static withdrawal strategy, according to which the withdrawal amount is always equal to the guaranteed amount. The valuation approach is based on the decomposition of the product into living and death benefits. The model makes use of the standard no-arbitrage models of mathematical finance, which extend the Black-Scholes framework to insurance contracts, assuming the fund follows a geometric Brownian motion and the insurance fee is paid, on an ongoing basis, as a proportion of the assets. We develop a sensitivity analysis, which shows how the value of the product varies with the key parameters, including the age of the policyholder at the inception of the contract, the guaranteed rate, the risk-free rate, and the fund volatility. We calculate the fair fee, using Monte Carlo simulations under different scenarios. We give special attention to the impact of mortality risk on the value of the option, using a flexible model of mortality dynamics, which allows for the possible perturbations by mortality shock of the standard mortality tables used by practitioners. Moreover, we evaluate the introduction of roll-up and step-up options and the effect of the decision to delay withdrawing. Empirical analyses are performed, and numerical results are provided
Albatrosses Following Fishing Vessels: How Badly Hooked Are They on an Easy Meal?
Fisheries have major impacts on seabirds, both by changing food availability and by causing direct mortality of birds during trawling and longline setting. However, little is known about the nature and the spatial-temporal extent of the interactions between individual birds and vessels. By studying a system in which we had fine-scale data on bird movements and activity, and near real-time information on vessel distribution, we provide new insights on the association of a threatened albatross with fisheries. During early chick-rearing, black-browed albatrosses Thalassarche melanophris from two different colonies (separated by only 75 km) showed significant differences in the degree of association with fisheries, despite being nearly equidistant to the Falklands fishing fleet. Most foraging trips from either colony did not bring tracked individuals close to vessels, and proportionally little time and foraging effort was spent near ships. Nevertheless, a few individuals repeatedly visited fishing vessels, which may indicate they specialise on fisheries-linked food sources and so are potentially more vulnerable to bycatch. The evidence suggests that this population has little reliance on fisheries discards at a critical stage of its nesting cycle, and hence measures to limit fisheries waste on the Patagonian shelf that also reduce vessel attractiveness and the risk of incidental mortality, would be of high overall conservation benefit
- …