6,807 research outputs found
A review of the population structure of yellowfin tuna, Thunnus albacares, in the Eastern Pacific Ocean
ENGLISH: Since its inception in 1950 by agreement between the Republic of Costa Rica and the United States of America, the Inter-American Tropical Tuna Commission has been engaged in studies of the biology, ecology and population dynamics of yellowfin tuna in the eastern Pacific Ocean. Prime consideration has been given to the evaluation of the effects of fishing pressure on the yellowfin tuna in this area in order to estimate the maximum sustainable yield. A portion of the eastern Pacific has been defined by the Inter-American Tropical Tuna Commission (1963) as a regulatory area for yellowfin tuna (Figure 1). SPANISH: Desde su incepción en 1950, por un acuerdo entre la República de Costa Rica y los Estados Unidos de América, la Comisión Interamericana del Atún Tropical ha estado ocupada en los estudios de la biología, ecología y dinámica de las poblaciones del atún aleta amarilla en el Océano Pacífico Oriental. Se consideró primariamente la evaluación de los efectos de la
presión de la pesquería sobre el atún aleta amarilla en esta área, para poder estimar el rendimiento máximo sostenible. Una parte del Pacífico Oriental ha sido definida por la Comisión Interamericana del Atún Tropical (1963), como área de reglamentación del atún aleta amarilla (Figura 1).
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Development of an inexpensive tire softening agent from readily available materials to improve traction in race car tires
Developing inexpensive tire softeners can prolong the life of tires and save people money that would be spent on new replacement tires. We have conducted two tests on the treated and untreated tires: the hardness test and the grip test. First, tire hardness was measured with a durometer on a tire that was treated with hot lap and a tire that was not. The tire that was treated with hot lap was slightly softer than the untreated tire substantiating the tire softener\u27s claim. Next, we will be cutting pieces out of the tire (also called omegas) and running them through an instron machine. This machine stretches the omegas at a certain frequency and reports back the hysteresis. The higher the hysteresis, the better the grip. Testing is ongoing, but initial results show that the tire softners did make the tires softer
Extensive loss of translational genes in the structurally dynamic mitochondrial genome of the angiosperm Silene latifolia
<p>Abstract</p> <p>Background</p> <p>Mitochondrial gene loss and functional transfer to the nucleus is an ongoing process in many lineages of plants, resulting in substantial variation across species in mitochondrial gene content. The Caryophyllaceae represents one lineage that has experienced a particularly high rate of mitochondrial gene loss relative to other angiosperms.</p> <p>Results</p> <p>In this study, we report the first complete mitochondrial genome sequence from a member of this family, <it>Silene latifolia</it>. The genome can be mapped as a 253,413 bp circle, but its structure is complicated by a large repeated region that is present in 6 copies. Active recombination among these copies produces a suite of alternative genome configurations that appear to be at or near "recombinational equilibrium". The genome contains the fewest genes of any angiosperm mitochondrial genome sequenced to date, with intact copies of only 25 of the 41 protein genes inferred to be present in the common ancestor of angiosperms. As observed more broadly in angiosperms, ribosomal proteins have been especially prone to gene loss in the <it>S. latifolia </it>lineage. The genome has also experienced a major reduction in tRNA gene content, including loss of functional tRNAs of both native and chloroplast origin. Even assuming expanded wobble-pairing rules, the mitochondrial genome can support translation of only 17 of the 61 sense codons, which code for only 9 of the 20 amino acids. In addition, genes encoding 18S and, especially, 5S rRNA exhibit exceptional sequence divergence relative to other plants. Divergence in one region of 18S rRNA appears to be the result of a gene conversion event, in which recombination with a homologous gene of chloroplast origin led to the complete replacement of a helix in this ribosomal RNA.</p> <p>Conclusions</p> <p>These findings suggest a markedly expanded role for nuclear gene products in the translation of mitochondrial genes in <it>S. latifolia </it>and raise the possibility of altered selective constraints operating on the mitochondrial translational apparatus in this lineage.</p
信息不对称与会计管制
本文从信息经济学的角度来解释和分析一些会计理论和现象由于一些集团比其他集团可 能有一些信息优势造成了信息不对称由于信息不对称而产生的不利选择和道德风险损 害了信息劣势方的利益本文从保护投资者的角度出发提出了减少不利选择的决策有用 性从维护股东和债仅人的利益出发提出了合同可以降低道德风险而上述目标的实现 最终都是通过对会计信息实行管制提高会计信息的质量特征来完成的对会计信息而 言主要的管制是通过会计准则来规范会计信息系统的运行 论文共分五个部分 第一部分是总论对论文进行全面概述 第二部分在论述信息不对称之前讨论了理想状态下的会计尽管理想状态不存在但对理 想状态下会计的描绘为现实...学位:管理学硕士院系专业:管理学院会计系_会计学学号:19951101
Search for associated Higgs boson production using like charge dilepton events in p(p)over-bar collisions at root s=1.96 TeV
We present a search for associated Higgs boson production in the process p (p) over bar -> W/ZH -> l(+/-)l'(+/-) + X in ee, e mu, and mu mu final states. The search is based on data collected by the D0 experiment at the Fermilab Tevatron Collider at root s = 1.96 TeV corresponding to 5.3 fb(-1) of integrated luminosity. We require two isolated leptons (electrons or muons) with the same electric charge and additional kinematic requirements. No significant excess above background is observed, and we set 95% C. L. observed (expected) upper limits on ratio of the production cross section to the standard model prediction of 6.4 (7.3) for a Higgs boson mass of 165 GeV and 13.5 (19.8) for a mass of 115 GeV
Black Stork Down: Military Discourses in Bird Conservation in Malta
Tensions between Maltese hunters and bird conservation NGOs have intensified over the past decade. Conservation NGOs have become frustrated with the Maltese State for conceding to the hunter lobby and negotiating derogations from the European Union’s Bird Directive. Some NGOs have recently started to organize complex field-operations where volunteers are trained to patrol the landscape, operate drones and other surveillance technologies, detect illegalities, and lead police teams to arrest poachers. We describe the sophisticated military metaphors which conservation NGOs have developed to describe, guide and legitimize their efforts to the Maltese public and their fee-paying members. We also discuss why such groups might be inclined to adopt these metaphors. Finally, we suggest that anthropological studies of discourse could help understand delicate contexts such as this where conservation NGOs, hunting associations and the State have ended in political deadlock
Forward-backward asymmetry in top quark-antiquark production
This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.84.112005
Measurement of the Semileptonic Charge Asymmetry using B(0)(s)→D(s)μX Decays
This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.110.011801
Improved determination of the width of the top quark
This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.85.091104
Combined search for the standard model Higgs boson decaying to bb-bar using the D0 Run II data set
This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.109.121802
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