bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conserved Genetic Architecture Underlying Individual Recombination Rate Variation in a Wild Population of Soay Sheep (Ovis aries)
Authors: Johnston Susan E , Bérénos Camillo , Slate Jon , Pemberton Josephine M 
Published: March 2016

Abstract
Meiotic recombination breaks down linkage disequilibrium (LD) and forms new haplotypes, meaning that it is an important driver of diversity in eukaryotic genomes. Understanding the causes of variation in recombination rate is important in interpreting and predicting evolutionary phenomena and in understanding the potential of a population to respond to selection. However, despite attention in model systems, there remains little data on how recombination rate varies at the individual level in natural populations. Here we used extensive pedigree and high-density SNP information in a wild population of Soay sheep (Ovis aries) to investigate the genetic architecture of individual autosomal recombination rates. Individual rates were high relative to other mammal systems and were higher in males than in females (autosomal map lengths of 3748 and 2860 cM, respectively). The heritability of autosomal recombination rate was low but significant in both sexes (h2 = 0.16 and 0.12 in females and males, respectively). In females, 46.7% of the heritable variation was explained by a subtelomeric region on chromosome 6; a genome-wide association study showed the strongest associations at locus RNF212, with further associations observed at a nearby ∼374-kb region of complete LD containing three additional candidate loci, CPLX1, GAK, and PCGF3. A second region on chromosome 7 containing REC8 and RNF212B explained 26.2% of the heritable variation in recombination rate in both sexes. Comparative analyses with 40 other sheep breeds showed that haplotypes associated with recombination rates are both old and globally distributed. Both regions have been implicated in rate variation in mice, cattle, and humans, suggesting a common genetic architecture of recombination rate variation in mammals.
Penetrance of Congenital Heart Disease in a Mouse Model of Down Syndrome Depends on a Trisomic Potentiator of a Disomic Modifier
Authors: Li Huiqing , Edie Sarah , Klinedinst Donna , Jeong Jun Seop , Blackshaw Seth , Maslen Cheryl L , Reeves Roger H 
Published: March 2016

Abstract
Down syndrome (DS) is a significant risk factor for congenital heart disease (CHD), increasing the incidence 50 times over the general population. However, half of people with DS have a normal heart and thus trisomy 21 is not sufficient to cause CHD by itself. Ts65Dn mice are trisomic for orthologs of &gt;100 Hsa21 genes, and their heart defect frequency is significantly higher than their euploid littermates. Introduction of a null allele of Creld1 into Ts65Dn increases the penetrance of heart defects significantly. However, this increase was not seen when the Creld1 null allele was introduced into Ts1Cje, a mouse that is trisomic for about two thirds of the Hsa21 orthologs that are triplicated in Ts65Dn. Among the 23 genes present in three copies in Ts65Dn but not Ts1Cje, we identified Jam2 as necessary for the increased penetrance of Creld1-mediated septal defects in Ts65Dn. Thus, overexpression of the trisomic gene, Jam2, is a necessary potentiator of the disomic genetic modifier, Creld1. No direct physical interaction between Jam2 and Creld1 was identified by several methods. Regions of Hsa21 containing genes that are risk factors of CHD have been identified, but Jam2 (and its environs) has not been linked to heart formation previously. The complexity of this interaction may be more representative of the clinical situation in people than consideration of simple single-gene models.
An efficient numerical procedure for calculating periodic vibrations of elastic mechanisms
Authors: Van Khang Nguyen , Phong Dien Nguyen , Sy Nam Nguyen 
Published: March 2016

This paper proposes a numerical procedure based on the well-known Newmark integration method to determine initial conditions for the periodic solution of a system of linear differential equations with time-periodic coefficients. Based on this, steady-state periodic vibrations of mechanisms with elastic elements governed by linearized differential equations with time-periodic coefficients can be conveniently calculated. The proposed procedure is demonstrated by a dynamic model of a planar four-bar mechanism with the flexible coupler.
Vibration analysis of beams subjected to random excitation by the dual criterion of equivalent linearizationVibration analysis of beams subjected to random excitation by the dual criterion of equivalent linearization
Authors: Hieu Nguyen Nhu , Anh Nguyen Dong , Hai Ninh Quang 
Published: March 2016

In this paper responses of beams subjected to random loading are analyzed by the dual approach of the equivalent linearization method. The external random loading is assumed to be a space-wise and time-wise white noise in which the exact solutions of the modal equations can be found. A system of nonlinear algebraic equations for linearization coefficients of the modal linearized system is obtained in a closed form and is solved by the fixed-point iteration method. Results obtained from the proposed dual criterion are compared with the exact solution and those obtained from other approaches including energy method, and conventional linearization method. It is observed that the solution obtained by the dual criterion is in good agreement with the exact solution, especially, in the case of strong nonlinearity of beam.
África: ¿el continente olvidado?
Authors: Acuña Barrantes Henry 
Published: March 2016

<p>Décadas atrás, África había estado relegada a un segundo plano, pero desde que China empezó a invertir y a asentarse en territorio africano hace varios años, numerosos países comenzaron también a mostrar interés por el continente. Y en esa perspectiva, a medida que mejora la reputación de África como territorio viable para la inversión, aumenta su importancia comercial. A diferencia del momento del cambio de milenio, cuando se consideraba el continente un caso perdido, ahora existe un renovado optimismo gracias a las mejoras de los indicadores sociales y económicos. Al respecto, autores como Serge y Beuret dicen lo siguiente:</p><p>[…] China ha conseguido un objetivo esencial: volver a dar a África verdadero valor, tanto a los ojos de sus habitantes como en el extranjero. Nunca Occidente se había interesado tanto por África como desde que China partió a su conquista. Estadounidenses, europeos, japoneses o australianos, todos han captado el mensaje. Han comprendido que si los chinos se desplazan e invierten hasta ese punto en el continente, prestan, compran y venden, es que debe haber un interés que ellos habían subestimado. </p>
Многолетняя динамика загрязнения органическими веществами донных осадков бухты Круглая (Севастополь, Чёрное море)
Authors: Тихонова Е. А. 
Published: March 2016

Актуальность исследования загрязнения бухты Круглая обусловлена неблагоприятной обстановкой в её акватории в сезоны с усиленным антропогенным прессом и условиями среды, благоприятными для активизации процессов роста биологических объектов. Особенно это касается загрязнения органическими веществами, как от аварийных источников, так и при естественных процессах жизнедеятельности населяющих биотопы организмов. Конечным пунктом миграции и осаждения этих веществ являются донные осадки, анализ которых даёт возможность представить устойчивую картину загрязнения. Поэтому целью работы стала оценка многолетних изменений состояния донных осадков в бухте Круглая. Материалом для исследования послужили пробы донных осадков, отобранные в бухте Круглая дночерпателем Петерсена. В подготовленных соответствующим образом воздушно-сухих пробах находили общее количество хлороформ-экстрагируемых веществ ― весовым методом, нефтяных углеводородов ― методом инфракрасной спектрометрии. В результате анализа многолетней динамики загрязнения органическими веществами донных осадков бухты Круглая (Севастополь, Чёрное море) в период 2006–2015 гг. выявлены его неравномерное распределение по акватории бухты и явная приуроченность к источникам загрязнения. Наиболее чистой является центральная часть акватории, а наиболее загрязнённой ― вершина бухты, где на отдельных точках степень загрязнения достигает IV уровня. Об интенсивном накоплении загрязняющих веществ на станции 01 свидетельствую высокие концентрации хлороформ-экстрагируемых веществ (на самой станции ― 900, в прибрежных наносах вблизи станции ― 620 мг·100 г−1 воздушно-сухого донного осадка). Таким образом, отмечено общее снижение концентрации хлороформ-экстрагируемых веществ за весь период исследований, за исключением станции 02, но доля нефтяных углеводородов выше по всей акватории вершины б. Круглой.
Technology Focus: Multilateral/ Extended-Reach Wells (May 2015)
Authors: Aadnoy Bernt 
Published: March 2016

Technology Focus
The development of multilateral wells and long-reach wells has become important to maximizing recovery for many oil fields. These technologies are often applied in offshore environments, where large reservoir areas are drained from one or more platforms.
In the late 1980s, long-reach wells started to use existing infrastructure better by drilling beyond the design limits at that time. Several major operators were extending their limits, and, in the late 1990s, BP’s Wytch Farm showed that a horizontal departure exceeding 10 km was feasible. This had a significant effect on the industry because offshore platforms now could be designed for up to 10-km reach as opposed to the early 1980s, where 3-km reach was common. A field could now be developed with one platform instead of three, resulting in enormous savings.
Multilateral-well technology also matured during the past 2 decades. There were many drivers for this development. One of the most important was the desire to increase production in tight reservoirs. Another advantage is directional control. Well stimulation with fracturing has the drawback that the fracture direction is controlled by the in-situ stresses in the rock. Multilateral branches, on the other hand, can be drilled in any direction.
There is a considerable technology development around these technologies. Those that help clear the challenges such as those related to wellbore stability, wellbore friction, equipment limitations, and operational aspects can be considered mature technologies today.
The main benefit from directional drilling is the maximizing of reservoir recovery. From this perspective, multilateral/extended-reach wells may be considered one of the most important means of improved oil recovery.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE/IADC 163525 Setting Free the Bear: The Challenges and Lessons of the Ursa A-10 Deepwater ERD Well by John Gradishar, Shell, et al.
SPE/IADC 163487 Case History of a Challenging Thin-Oil-Column Extended- Reach-Drilling Development at Sakhalin by Vishwas P. Gupta, ExxonMobil, et al.
SPE 170831 Going Long—Overcoming Challenges in Completing 3600-m Laterals by R. Liston, Step Energy Services, et al.
The Association between Executive Pay Structure and the Transparency of Restatement Disclosures
Authors: Hogan Brian , Jonas Gregory A. 
Published: March 2016

SYNOPSIS
Restatement disclosures have evolved into two basic categories: reissuances (Big “R”) and revisions (little “r”). A reissuance restatement requires an 8-K filing, whereas a revision restatement can be disclosed in less transparent ways. The high-transparency of a reissuance restatement disclosure (8-K) results in a greater likelihood of negative effects on companies, executives, and auditors (e.g., Plumlee and Yohn 2008; Burks 2010). Determining whether an 8-K filing is required involves judgment regarding materiality of the restatement, thus creating ambiguity as to the correct disclosure method. Such judgment also introduces the potential to opportunistically choose the method of disclosure. We study the restatement disclosure choices of companies to examine whether executive pay structure is associated with disclosure transparency. Using a sample of 1,178 restatements from the years 2004 through 2013, our results show that as the equity proportion of executive pay increases, the likelihood of a high-transparency disclosure decreases. However, as the difference in pay structure between the CEO and CFO increases, the likelihood of a high-transparency disclosure increases. Overall, our results suggest that executive pay structure influences disclosure choice and that pay structure differences between the CEO and CFO may mitigate such influence.
Data Availability: All data are available from public sources identified in the paper.
Propensity Score Matching in Accounting Research
Authors: Shipman Jonathan E. , Swanquist Quinn T. , Whited Robert L. 
Published: March 2016

ABSTRACT
Propensity score matching (PSM) has become a popular technique for estimating average treatment effects (ATEs) in accounting research. In this study, we discuss the usefulness and limitations of PSM relative to more traditional multiple regression (MR) analysis. We discuss several PSM design choices and review the use of PSM in 86 articles in leading accounting journals from 2008–2014. We document a significant increase in the use of PSM from zero studies in 2008 to 26 studies in 2014. However, studies often oversell the capabilities of PSM, fail to disclose important design choices, and/or implement PSM in a theoretically inconsistent manner. We then empirically illustrate complications associated with PSM in three accounting research settings. We first demonstrate that when the treatment is not binary, PSM tends to confine analyses to a subsample of observations where the effect size is likely to be smallest. We also show that seemingly innocuous design choices greatly influence sample composition and estimates of the ATE. We conclude with suggestions for future research considering the use of matching methods.
Data Availability: All data used are available from sources cited in the text.
Factors influencing sexual behaviour between tourists and tourism employees: A systematic review
Authors: Simkhada Padam P , Sharma Aditi , Van Teijlingen Edwin R , Beanland Rachel L 
Published: March 2016

<p><strong><em>Background:</em></strong> Increased travel abroad has a significant impact on the incidence and prevalence of Sexually Transmitted Infections (STIs). Previous reviews have focused on the knowledge, attitudes and behaviour of tourists and acquisition of STIs. Less is known about the impact on tourism operators in countries visited by tourists. The aim of this review is to ascertain factors influencing sexual behaviour between workers in the tourism industry and tourists; exploring the prevalence of sexual behaviour between the two populations, their perceptions of sexual risk while engaging in sexual activities and the knowledge of tourism operators regarding STIs.</p><p><strong><em>Methods:</em></strong> A systematic review was conducted. Database searches were performed in Medline/Ovid, EMBASE, Cochrane library and CINAHL for studies published between 2000 and March 2016. Grey literature searches were completed in the NHS database and Google Scholar between 2000 and December 2013. Papers were independently selected by two researchers. Data were extracted and critically appraised using a pre-designed extraction form and adapted CASP checklist.</p><p><strong><em>Results: </em></strong>The search identified 1,602 studies and 16 were included after review of the full text. Studies were conducted in nine countries. Findings suggest that STI knowledge, attitude and practice were fairly good among tourists and tourism workers, but there is a need for pre-travel advice for travellers, especially those travelling to low and middle-income countries. Greater importance was given to tourists than to tourism operators and locals interacting with tourists. Studies suggest that as a group both tourist and tourist workers were likely to engage in sexual activities. Overall, both condom use and STI screening were low, among tourists as well as tourism operators. Furthermore, studies reported links between drug and alcohol use and sexual behaviour and risk taking.</p><p><strong><em>Conclusion:</em></strong><strong> </strong>Although less research appeared to have been conducted among tourism workers than tourists, it does demonstrate the need for education, training and promotion of travel medicine. STI screening, pre-travel advice, travel history in terms of contracting STIs and safe-sex awareness-raising are needed. More and better sexual health education and relevant tourism policies are needed globally. </p>
Five-year clinical results of cervical total disc replacement compared with anterior discectomy and fusion for treatment of 2-level symptomatic degenerative disc disease: a prospective, randomized, controlled, multicenter investigational device exemption clinical trial
Authors: Radcliff Kris , Coric Domagoj , Albert Todd 
Published: March 2016

OBJECTIVE
The purpose of this study was to report the outcome of a study of 2-level cervical total disc replacement (Mobi-C) versus anterior cervical discectomy and fusion (ACDF). Although the long-term outcome of single-level disc replacement has been extensively described, there have not been previous reports of the 5-year outcome of 2-level cervical disc replacement.

METHODS
This study reports the 5-year results of a prospective, randomized US FDA investigational device exemption (IDE) study conducted at 24 centers in patients with 2-level, contiguous, cervical spondylosis. Clinical outcomes at up to 60 months were evaluated, including validated outcome measures, incidence of reoperation, and adverse events. The complete study data and methodology were critically reviewed by 3 independent surgeon authors without affiliation with the IDE study or financial or institutional bias toward the study sponsor.

RESULTS
A total of 225 patients received the Mobi-C cervical total disc replacement device and 105 patients received ACDF. The Mobi-C and ACDF follow-up rates were 90.7% and 86.7%, respectively (p = 0.39), at 60 months. There was significant improvement in all outcome scores relative to baseline at all time points. The Mobi-C patients had significantly more improvement than ACDF patients in terms of Neck Disability Index score, SF-12 Physical Component Summary, and overall satisfaction with treatment at 60 months. The reoperation rate was significantly lower with Mobi-C (4%) versus ACDF (16%). There were no significant differences in the adverse event rate between groups.

CONCLUSIONS
Both cervical total disc replacement and ACDF significantly improved general and disease-specific measures compared with baseline. However, there was significantly greater improvement in general and disease-specific outcome measures and a lower rate of reoperation in the 2-level disc replacement patients versus ACDF control patients.
Clinical trial registration no. NCT00389597 (clinicaltrials.gov)
Deep brain stimulator implantation in a diagnostic MRI suite: infection history over a 10-year period
Authors: Martin Alastair J. , Larson Paul S. , Ziman Nathan , Levesque Nadja , Volz Monica , Ostrem Jill L. , Starr Philip A. 
Published: March 2016

OBJECTIVE
The objective of this study was to assess the incidence of postoperative hardware infection following interventional (i)MRI–guided implantation of deep brain stimulation (DBS) electrodes in a diagnostic MRI scanner.

METHODS
A diagnostic 1.5-T MRI scanner was used over a 10-year period to implant DBS electrodes for movement disorders. The MRI suite did not meet operating room standards with respect to airflow and air filtration but was prepared and used with conventional sterile procedures by an experienced surgical team. Deep brain stimulation leads were implanted while the patient was in the magnet, and patients returned 1–3 weeks later to undergo placement of the implantable pulse generator (IPG) and extender wire in a conventional operating room. Surgical site infections requiring the removal of part or all of the DBS system within 6 months of implantation were scored as postoperative hardware infections in a prospective database.

RESULTS
During the 10-year study period, the authors performed 164 iMRI-guided surgical procedures in which 272 electrodes were implanted. Patients ranged in age from 7 to 78 years, and an overall infection rate of 3.6% was found. Bacterial cultures indicated Staphylococcus epidermis (3 cases), methicillin-susceptible Staphylococcus aureus (2 cases), or Propionibacterium sp. (1 case). A change in sterile practice occurred after the first 10 patients, leading to a reduction in the infection rate to 2.6% (4 cases in 154 procedures) over the remainder of the procedures. Of the 4 infections in this patient subset, all occurred at the IPG site.

CONCLUSIONS
Interventional MRI–guided DBS implantation can be performed in a diagnostic MRI suite with an infection risk comparable to that reported for traditional surgical placement techniques provided that sterile procedures, similar to those used in a regular operating room, are practiced.
Incorrect umbilical vein catheterization is associated with severe periventricular hemorrhages and mortality in extremely premature newborns
Authors: Kurtom Waleed , Quast Deborah , Worley Leslie , Oelberg David G. 
Published: March 2016

OBJECTIVE: To investigate the relationship between umbilical vein catheter (UVC) placement and death in extremely premature newborns (<29 weeks gestation). STUDY DESIGN: Utilizing a retrospective, case-control study design, results for newborns that received UVC placements and died were compared with those who received UVC placements and survived ( n = 719) by univariate and multiple logistic regression analyses. RESULT: Death rate was 30% in infants with low lines versus 16% in those without ( p = 0.012). High UVC tip placement significantly and independently increased severe periventricular hemorrhages ( p = 0.014). Severe periventricular hemorrhage increased death rates by 3-fold independent of gestational age ( p <  0.001). Proper line placement significantly reduced severe periventricular hemorrhage by 2.5-fold independent of gestational age ( p = 0.019). CONCLUSION: In extremely premature newborns, incorrect UVC placement is significantly associated with death through its relation to severe periventricular hemorrhage.
Characterization of new cardioprotective principle isolated from methanolic extract of <i>Allium humile</i> leaves from Himalayan region
Authors: Dobhal Yogita , Parcha Versha , Dhasmana D. C. 
Published: March 2016

<p class="Abstract">In modern era scientists have been trying to validate many properties of <em>Allium</em> species, especially in terms of the identity of the active components, their mechanism of action and exploring the potential benefits as food supplements. Thus, the present study has been designed to characterize the isolated cardioprotective compound from <em>Allium humile</em> leaves. Chromatographic purification of the methanolic extract of<em> A. humile</em> leaves isolated ajoene (enol form) (AH-1)- a new potent cardioprotective principle, along with three known compounds allicin (AH-2) and alliin (AH-3) and a flavonoid quercetin (AH-4). The structures of all the isolates (AH-1, AH-2) were characterized by using modern spectroscopic analysis UV, IR, <sup>1</sup>H and <sup>13</sup>C NMR and mass spectrometry. Furthermore, the new isolated compound pharmacologically conformed for cardioprotective effect. The data of known compounds (AH-2, AH-4) were further compared with the reported data for these compounds.</p><p> </p>