206 research outputs found
Comparison of horse mackerel length frequencies obtained from research vessels and commercial midwater trawlers: implications for biomass estimation
The validity of abundance estimates from hydroacoustic surveys relies, inter alia, on the ability of the fishing gear on the research vessel to sample non-selectively. This study compares the length frequencies of Cape horse mackerel Trachurus trachurus capensis taken in Namibian waters by the R.V. Welwitchia and commercial midwater trawlers. Results indicate that the length distributions of catches taken by the Welwitchia were significantly different from those from commercial trawlers, with a greater proportion of fish >25 cm being sampled by the latter. Also, the biomass estimated per length-class from hydroacoustic surveys over the period 1994â2000 was compared with those from annual landings of the commercial fishery. The length distribution of horse mackerel in purseseine catches compares favourably with those from the research vessel. However, comparisons with the midwater trawl catches indicated that the length frequencies obtained from research vessels during the years 1994â1997 underestimated the number of large fish in the population and biased the biomass in those years. From 1998 to 2000 the bias was negligible. The magnitude of the error varied between years, but it remained fairly low. To compensate for this bias, length distribution data from midwater trawlers should be integrated into the acoustic biomass calculation procedure. Keywords: acoustic estimates, avoidance, horse mackerel, length frequencies, trawl catchesAfrican Journal of Marine Science 2001, 23: 265â27
Effects of the reaction cavity on metastable optical excitation in ruthenium-sulfur dioxide complexes
We report photoexcited-state crystal structures for two new members of the
[Ru(SO_2)(NH_3)_4X]Y family: 1:X=H2O, Y=(+/-)-camphorsulfonate_2;
2:X=isonicotinamide, Y=tosylate_2. The excited states are metastable at 100 K,
with a photoconversion fraction of 11.1(7)% achieved in 1, and 22.1(10)% and
26.9(10)% at the two distinct sites in 2.We further show using solid-state
density-functional-theory calculations that the excited-state geometries
achieved are strongly influenced by the local crystal environment. This result
is relevant to attempts to rationally design related photoexcitation systems
for optical data-storage applications.Comment: 6 pages, 5 figure
Deformation of canonical morphisms and the moduli of surfaces of general type
In this article we study the deformation of finite maps and show how to use
this deformation theory to construct varieties with given invariants in a
projective space. Among other things, we prove a criterion that determines when
a finite map can be deformed to a one--to--one map. We use this criterion to
construct new simple canonical surfaces with different and . Our
general results enable us to describe some new components of the moduli of
surfaces of general type. We also find infinitely many moduli spaces having one component whose general point corresponds to a
canonically embedded surface and another component whose general point
corresponds to a surface whose canonical map is a degree 2 morphism.Comment: 32 pages. Final version with some simplifications and clarifications
in the exposition. To appear in Invent. Math. (the final publication is
available at springerlink.com
Evaluation of the Effects of Fluids Upon the Flexural and Parallel-plate Loading Behavior of Glass Fiber Reinforced-vinyl Ester Resin Matrix Composite Pipes
A putative role for homocysteine in the pathophysiology of acute bacterial meningitis in children
Sleep deprivation increases oleoylethanolamide in human cerebrospinal fluid
This study investigated the role of two fatty acid ethanolamides, the endogenous cannabinoid anandamide and its structural analog oleoylethanolamide in sleep deprivation of human volunteers. Serum and cerebrospinal fluid (CSF) samples were obtained from 20 healthy volunteers before and after a night of sleep deprivation with an interval of about 12 months. We found increased levels of oleoylethanolamide in CSF (P = 0.011) but not in serum (P = 0.068) after 24 h of sleep deprivation. Oleoylethanolamide is an endogenous lipid messenger that is released after neural injury and activates peroxisome proliferator-activated receptor-α (PPAR-α) with nanomolar potency. Exogenous PPAR-α agonists, such as hypolipidemic fibrates and oleoylethanolamide, exert both neuroprotective and neurotrophic effects. Thus, our results suggest that oleoylethanolamide release may represent an endogenous neuroprotective signal during sleep deprivation
Effect of the hardener to epoxy monomer ratio on the water absorption behavior of the DGEBA/TETA epoxy system
Impacto da irrigação sobre os solos de perĂmetros irrigados na Bacia do AcaraĂș, CearĂĄ, Brasil
To whom does the law speak? Canvassing a neglected picture of lawâs interpretive field
Among the most common strategies underlying the so-called indeterminacy thesis is the following two-step argument: (1) that law is an interpretive practice, and that evidently legal actors more generally hold different (and competing) theories of meaning, which lead to disagreements as to what the law says (that is, as to what the law is); (2) and that, as there is no way to establish the prevalence of one particular theory of meaning over the other, indeterminacy is pervasive in law. In this paper I offer some reflections to resist this trend. In particular I claim that a proper understanding of law as an authoritative communicative enterprise sheds new light on the relation between the functioning of the law and our theories of interpretation, leading to what can be considered a neglected conclusion: the centrality of the linguistic criterion of meaning in our juridical interpretive practices. In the first part of the chapter I discuss speech-act theory in the study of law, assessing its relevance between alternative options. Then I tackle the âto whom does the law speak?â question, highlighting the centrality of lay-people for our juridical practices. Lastly, I examine the consequences of this neglected fact for our interpretive theories
Which parameters to use for sleep quality monitoring in team sport athletes? A systematic review and metaanalysis
Background: Sleep quality is an essential component of athlete's recovery. However, a better understanding of the parameters to adequately quantify sleep quality in team sport athletes is clearly warranted. Objective: To identify which parameters to use for sleep quality monitoring in team sport athletes. Methods: Systematic searches for articles reporting the qualitative markers related to sleep in team sport athletes were conducted in PubMed, Scopus, SPORTDiscus and Web of Science online databases. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. For the meta-analysis, effect sizes with 95% CI were calculated and heterogeneity was assessed using a random-effects model. The coefficient of variation (CV) with 95% CI was also calculated to assess the level of instability of each parameter. Results: In general, 30 measuring instruments were used for monitoring sleep quality. A meta-analysis was undertaken on 15 of these parameters. Four objective parameters inferred by actigraphy had significant results (sleep efficiency with small CV and sleep latency, wake episodes and total wake episode duration with large CV). Six subjective parameters obtained from questionnaires and scales also had meaningful results (Pittsburgh Sleep Quality Index (sleep efficiency), Likert scale (Hooper), Likert scale (no reference), Liverpool Jet-Lag Questionnaire, Liverpool Jet-Lag Questionnaire (sleep rating) and RESTQ (sleep quality)). Conclusions: These data suggest that sleep efficiency using actigraphy, Pittsburgh Sleep Quality Index, Likert scale, Liverpool Jet-Lag Questionnaire and RESTQ are indicated to monitor sleep quality in team sport athletes
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