bluuebunny/crossref_metadata_2025_split huggingface dataset:
Survival of the weakest: increased frond mechanical strength in a wave‐swept kelp inhibits self‐pruning and increases whole‐plant mortality
Authors: Demes Kyle W. , Pruitt Jonathan N. , Harley Christopher D.G. , Carrington Emily 
Published: February 2013

Summary

Organisms' ability to withstand the physical forces of their environment is a key determinant of their success. Mechanical performance of organisms is often associated with the properties of the tissues that compose them. In mechanically stressful habitats, intraspecific variation in tissue properties may result in differential survivorship and enable natural selection to act on material performance.

We tested the hypothesis that tissue mechanical properties affect survivorship (a fitness component) of the perennial kelp, Egregia menziesii, in a mechanically stressful, wave‐swept intertidal habitat.

We measured intraspecific variation in strength and flexibility in 38 E. menziesii and tracked their survivorship in the field over the winter storm season to determine whether variation in mechanical properties led to differential survivorship.

Significant interindividual variation was found in most mechanical properties, including strength and flexibility. Individuals with increased flexibility and decreased strength were more likely to survive the duration of our study, although this effect was more pronounced in individuals with smaller holdfasts. Increased frond strength was also associated with a reduction in self‐thinning, potentially explaining the observed increase in whole‐plant mortality with increasing frond strength.

Results from this study demonstrate that variation in tissue mechanical properties among conspecifics can influence survivorship and this may have important evolutionary implications.
Caught in the middle: Tensions around the emergency department care of people with advanced cancer
Authors: Jelinek George A , Marck Claudia H , Weiland Tracey J , Philip Jennifer , Boughey Mark , Weil Jennifer , Lane Heather 
Published: February 2013

AbstractBackground:People with advanced cancer frequently present to hospital EDs. International studies report conflicting attitudes towards providing such care and difficulties with communication. The experience of Australian clinicians, however, is not described.Objective:The present study aims to identify issues important to emergency, palliative care (PC) and oncology clinical staff in managing people with advanced cancer presenting to EDs.Methods:We qualitatively explored views of Australian clinicians working in emergency medicine, PC and oncology, via focus groups at two major hospitals and two community PC services in Melbourne, Victoria, and emergency clinicians from all other Australian states and territories via semi‐structured telephone interviews. Purposive sampling for both groups ensured representation of experience, discipline and region of work. The focus groups and interviews were audio‐recorded, transcribed and a thematic analysis identified issues important to participants.Results:The overarching theme was EDs being ‘caught in the middle’ when providing care to patients with advanced cancer in the physical environment (privacy, noise, lack of information and delay and lack of defined pathways), the available resources (access block and overcrowding, time pressures, competition with other emergencies, lack of alternatives) and the roles and expectations of the staff providing care (seniority and comfort with dying, views of dying in the ED, expertise and comfort in caring for those with advanced illness).Conclusion:Despite limitations in the ED environment and resources, clinicians in oncology, PC and emergency medicine support the important role the ED plays in providing the necessary access and expertise for people with advanced cancer.
Exploring the Personal Histories of the Top Executives ofUSFirms Using a Quantitative Approach: Is There a Geographical Relationship with Corporate Headquarters, and Does It Influence Firm Performance?
Authors: O'HAGAN SEAN B. , RICE MURRAY 
Published: February 2013

AbstractThis paper analyses where top executives were born and where they attended university to uncover regional groupings of the most influential executives that shape corporate culture and strategy in theUnitedStates. Within the context of this paper, it is argued that the personal histories of top executives influence their decision‐making abilities, and thus corporate culture. It was found that intra‐regional, intra‐state, and intra‐city links were noteworthy factors in executive selection. Distances were higher, and percentages of intra‐regional links were lower for more profitable and higher growth firms. This indicates that more competitive firms acquire executives that have experienced different institutions during their lives and university educations. On the other hand, less profitable and lower growth firms are more likely to obtain executives embedded in similar institutions that already exist within the firm. The results suggest that key choices made by corporate America are influenced in part by geography far more complex than its own operations.
Assessing functional connectivity: a landscape approach for handling multiple ecological requirements
Authors: Mimet Anne , Houet Thomas , Julliard Romain , Simon Laurent 
Published: February 2013

Summary

The improvement of tools for protecting biodiversity requires integrating habitat connectivity to build efficient ecological networks that facilitate the movement of species under pressure from global change. Several methodological and scientific challenges are faced in constructing such networks. First, ecological networks need to incorporate habitat connectivity for species with different ecological requirements. Secondly, the networks should be based on functional connectivity rather than on structural connectivity alone. Thirdly, connectivity needs to be treated as a continuous variable.
We propose a non‐oriented approach of landscape description to identify favourable areas and measure functional connectivity for multi‐specific applications, using three groups of common bird species (farmland specialists, forest specialists and generalists) as indicators of biodiversity.

In the highly anthropized region of Seine‐et‐Marne, we defined 20 landscape types based on composition and configuration. We used statistical modelling to obtain a value of favourability for each landscape type for each bird group. We then mapped landscape favourability, for the three groups in 1982 and 2003 to identify favourable entities (adjacent favourable landscape units) and determine connectivity. We then examined temporal changes in the favourable areas and their connectivity and determined the sensitivity of the favourable landscape types to land cover change.

Composition and configuration both influenced landscape favourability. Some landscape types were favourable for several groups of species and could potentially serve as junction landscapes in ecological networks that accommodate a variety of ecological requirements. Increasing urbanization and fragmentation between 1982 and 2003 resulted in a decrease in favourable landscape units, as well as consequent decreases in favourable areas and connectivity, for the three species groups. Connectivity loss was greatest for farmland and generalist species, as it was already high for forest species in 1982.

Such a non‐oriented landscape description could be used to delineate multi‐specific ecological networks at regional and national scales and could be further developed to study the connectivity of communities. The maps of favourability produced here could also be used in combination with other methods, such as graphs or circuits, to detect ecological corridors and stepping stones to habitat connectivity.
The Innervation of Canine Hip Joint Capsule: An Anatomic Study
Authors: Huang C. H. , Hou S. M. , Yeh L. S. 
Published: February 2013

SummaryTo clarify the contributions of the nerves supplying the canine hip joint capsule for clinical application, cadaver study of six healthy mongrel dogs was performed. The pelvises and hindlimbs of cadavers were dissected and fixed in formaldehyde. Innervation of the joint capsule was investigated with the aid of an operative microscope. As a result, the canine hip joint capsule receives multiple innervations from articular branches of four nerves. They are articular nerve fibres of femoral, obturator, cranial gluteal and sciatic nerves from the cranioventral, caudoventral, craniolateral and dorsolateral directions of the joint, respectively. No branch originating from the caudal gluteal nerve was observed innervating the hip joint capsule. Our data provides useful information for research on the canine hip joint, including pain analysis with hip disorders and surgical nerve blockade to relieve pain.
GP obstetricians' views of the model of maternity care in New Zealand
Authors: Miller Dawn L. , Mason Zara , Jaye Chrystal 
Published: February 2013

BackgroundThe Lead Maternity Carer (LMC) model of maternity care, and independent midwifery practice, was introduced to New Zealand in the 1990s. The LMC midwife or general practitioner obstetrician (GPO) has clinical and budgetary responsibility for women's primary maternity care.AimsTo determine views of practising GPOs and former GPOs about the LMC model of care, its impact on maternity care in general practice, and future of maternity care in general practice.Methods10 GPOs and 13 former GPOs were interviewed: one focus group (n = 3), 20 semi‐structured interviews. The qualitative data analysis program ATLAS.ti assisted thematic analysis.ResultsParticipants thought the LMC model isolates the LMC – particularly concerning during intrapartum care, in rural practice, and covering 24‐hour call; Is not compatible with or adequately funded for GP participation; Excludes the GP from caring for their pregnant patients. Participants would like a flexible, locally adaptable, adequately funded maternity model, supporting shared care. Some thought work‐life balance and low GPO numbers could deter future GPs from maternity practice. Others felt with political will, support of universities, and Royal New Zealand College of General Practice and Royal Australian and New Zealand College of Obstetrics and Gynaecology, GPs could become more involved in maternity care again.ConclusionsParticipants thought the LMC model isolates maternity practitioners, is incompatible with general practice and causes loss of continuity of general practice care. They support provision of maternity care in general practice; however, for more GPs to become involved, the LMC model needs review.
Long‐term treatment outcomes of transvaginal mesh surgery versus anterior–posterior colporrhaphy for pelvic organ prolapse
Authors: Cao Qi , Chen Yi‐Song , Ding Jing‐Xin , Hu Chang‐Dong , Feng Wei‐Wei , Hu Wei‐Guo , Hua Ke‐Qin 
Published: February 2013

BackgroundIn spite of rapid growth in the use of vaginally placed mesh in pelvic reconstructive surgery, there are few reports on the long‐term efficacy and safety of mesh‐augmented repairs.AimsTo compare the long‐term outcomes of modified pelvic floor reconstructive surgery with mesh (MPFR) versus traditional anterior–posterior colporrhaphy (APC) for the treatment of pelvic organ prolapse (POP).MethodsThis retrospective cohort study involved 158 women who underwent surgical management of prolapse with MPFR (n = 84) or APC (n = 74) in the period between January 2007 and June 2008. Main outcome measures included pelvic organ prolapse quantification measurement, Short Form‐20 Pelvic Floor Distress Inventory (PFDI‐20), Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire (PISQ) questionnaires, perioperative outcomes, complications and a personal interview about urinary and sexual symptoms. Statistical analysis included comparison of means (Wilcoxon test or Student's t‐test) and proportions (χ2 test).ResultsAnatomical success rate for MPFR and APC was 88.1 versus 64.9% (P = 0.001), with a median follow‐up of 55 versus 56 months (range 49–66 months, P = 0.341). Both operations significantly improved quality of life, and a greater improvement was seen in MPFR group than in APC group (P = 0.013). Complication rates did not differ significantly between the two groups. The mesh erosion rate was 3.6%.ConclusionModified pelvic floor reconstructive surgery with mesh had better anatomical and functional outcomes than APC at 4–5 years postoperation, as an alternative, cheap and effective treatment option to mesh kits for the management of POP.
A novel technique for modified B‐Lynch suture for the control of atonic postpartum haemorrhage
Authors: Ali Mohammed K. , Badee Ahmed Y. A. , Abbas Ahmed M. , Shazly Sherif A.‐E. M. 
Published: February 2013

The B‐Lynch brace suture technique is a life‐saving procedure. It is a simple and safe alternative to hysterectomy. Thus, it preserves fertility with less surgical morbidity. In this case series, we evaluated the use of a novel modification of the B‐Lynch brace suture to minimise its potential reported complications. Five women with intractable primary atonic postpartum haemorrhage were reported. They were initially managed with bilateral uterine artery ligation. The procedure was resorted to women who did not respond to ligation. The procedure is efficient. Women were followed up for up to 24 months to report any complications.
Intraocular pressure reduction with topical medications and progression of normal‐tension glaucoma: a 12‐year mean follow‐up study
Authors: Kim Martha , Kim Dong Myung , Park Ki Ho , Kim Tae‐Woo , Jeoung Jin Wook , Kim Seok Hwan 
Published: February 2013

Abstract.Purpose:  To investigate whether the amount of intraocular pressure (IOP) reduction with topical medications is associated with the progression of normal‐tension glaucoma (NTG) and to identify risk factors for NTG progression.Methods:  The medical records of 121 eyes of 121 NTG patients, who were treated with topical medications for more than 7 years, were reviewed. NTG progression was defined by either structural (optic disc or retinal nerve fibre layer) or functional (visual field) deterioration. Patients were divided into tertile groups according to the percentage IOP reduction from baseline, and the cumulative probability of NTG progression between upper and lower tertile group was compared using Kaplan–Meier survival analysis. Multivariate analysis with Cox’s proportional hazard model was performed to identify the hazard ratio (HR) of clinical factors for NTG progression.Results:  The average follow‐up period was 12.2 years, and 56 of 121 eyes (46.3%) showed the NTG progression. Kaplan–Meier analysis revealed that upper tertile group (percentage IOP reduction >22.1%) showed a greater cumulative probability of non‐progression than lower tertile group (percentage IOP reduction < 13.3%; p = 0.012). Multivariate Cox’s proportional hazard model indicated that percentage reduction of IOP (HR = 0.964; p = 0.007) and the occurrence of disc haemorrhage (HR = 2.410; p = 0.008) were significantly associated with NTG progression.Conclusions:  The amount of IOP reduction using topical medications was related to NTG progression, and lower percentage reduction in IOP was a consistent risk factor for progression.
Covariate Adjustment in Estimating the Area Under ROC Curve with Partially Missing Gold Standard
Authors: Liu Danping , Zhou Xiao‐Hua 
Published: February 2013

SummaryIn ROC analysis, covariate adjustment is advocated when the covariates impact the magnitude or accuracy of the test under study. Meanwhile, for many large scale screening tests, the true condition status may be subject to missingness because it is expensive and/or invasive to ascertain the disease status. The complete‐case analysis may end up with a biased inference, also known as “verification bias.” To address the issue of covariate adjustment with verification bias in ROC analysis, we propose several estimators for the area under the covariate‐specific and covariate‐adjusted ROC curves (AUCx and AAUC). The AUCx is directly modeled in the form of binary regression, and the estimating equations are based on the U statistics. The AAUC is estimated from the weighted average of AUCx over the covariate distribution of the diseased subjects. We employ reweighting and imputation techniques to overcome the verification bias problem. Our proposed estimators are initially derived assuming that the true disease status is missing at random (MAR), and then with some modification, the estimators can be extended to the not missing at random (NMAR) situation. The asymptotic distributions are derived for the proposed estimators. The finite sample performance is evaluated by a series of simulation studies. Our method is applied to a data set in Alzheimer's disease research.
Estimating Time to Disease Progression Comparing Transition Models and Survival Methods—An Analysis of Multiple Sclerosis Data
Authors: Mandel Micha , Mercier Francois , Eckert Benjamin , Chin Peter , Betensky Rebecca A. 
Published: February 2013

SummaryThis article reports an analysis that aims to quantify the effect of fingolimod, an oral treatment for relapsing remitting multiple sclerosis (MS), on disability progression. The standard approach utilizes survival analysis methods, which may be problematic for MS studies that assess disability at only a few time points and include as a cardinal feature both relapses and remissions. Instead, a Markov transition model, originally developed in the framework of longitudinal data, is fit, and its special probabilistic properties are used to estimate survival curves for time to disability progression. The transition approach models the whole disability process and uses all available transition data for inference, while survival methods concentrate on a single event of interest and use only time to event data. This article compares the transition model approach to survival analysis methods, and discusses the differences in the interpretations of the estimated parameters. It applies both models to data obtained from two phase 3 clinical trials and finds that both yield positive effects for the new treatment compared to placebo, and provide similar estimates for the probability of disability progression over time. The transition model enables calculation of covariate‐specific transition matrices that describe the short‐term effect of treatment and other covariates on the disability process.
Gaussian Process‐Based Bayesian Nonparametric Inference of Population Size Trajectories from Gene Genealogies
Authors: Palacios Julia A. , Minin Vladimir N. 
Published: February 2013

SummaryChanges in population size influence genetic diversity of the population and, as a result, leave a signature of these changes in individual genomes in the population. We are interested in the inverse problem of reconstructing past population dynamics from genomic data. We start with a standard framework based on the coalescent, a stochastic process that generates genealogies connecting randomly sampled individuals from the population of interest. These genealogies serve as a glue between the population demographic history and genomic sequences. It turns out that only the times of genealogical lineage coalescences contain information about population size dynamics. Viewing these coalescent times as a point process, estimating population size trajectories is equivalent to estimating a conditional intensity of this point process. Therefore, our inverse problem is similar to estimating an inhomogeneous Poisson process intensity function. We demonstrate how recent advances in Gaussian process‐based nonparametric inference for Poisson processes can be extended to Bayesian nonparametric estimation of population size dynamics under the coalescent. We compare our Gaussian process (GP) approach to one of the state‐of‐the‐art Gaussian Markov random field (GMRF) methods for estimating population trajectories. Using simulated data, we demonstrate that our method has better accuracy and precision. Next, we analyze two genealogies reconstructed from real sequences of hepatitis C and human Influenza A viruses. In both cases, we recover more believed aspects of the viral demographic histories than the GMRF approach. We also find that our GP method produces more reasonable uncertainty estimates than the GMRF method.
Recovering Gradients from Sparsely Observed Functional Data
Authors: López‐Pintado Sara , McKeague Ian W. 
Published: February 2013

AbstractSummaryThe recovery of gradients of sparsely observed functional data is a challenging ill‐posed inverse problem. Given observations of smooth curves (e.g., growth curves) at isolated time points, the aim is to provide estimates of the underlying gradients (or growth velocities). To address this problem, we develop a Bayesian inversion approach that models the gradient in the gaps between the observation times by a tied‐down Brownian motion, conditionally on its values at the observation times. The posterior mean and covariance kernel of the growth velocities are then found to have explicit and computationally tractable representations in terms of quadratic splines. The hyperparameters in the prior are specified via nonparametric empirical Bayes, with the prior precision matrix at the observation times estimated by constrained ℓ1 minimization. The infinitessimal variance of the Brownian motion prior is selected by cross‐validation. The approach is illustrated using both simulated and real data examples.
Outcome Vector Dependent Sampling with Longitudinal Continuous Response Data: Stratified Sampling Based on Summary Statistics
Authors: Schildcrout Jonathan S. , Garbett Shawn P. , Heagerty Patrick J. 
Published: February 2013

AbstractSummaryThe analysis of longitudinal trajectories usually focuses on evaluation of explanatory factors that are either associated with rates of change, or with overall mean levels of a continuous outcome variable. In this article, we introduce valid design and analysis methods that permit outcome dependent sampling of longitudinal data for scenarios where all outcome data currently exist, but a targeted substudy is being planned in order to collect additional key exposure information on a limited number of subjects. We propose a stratified sampling based on specific summaries of individual longitudinal trajectories, and we detail an ascertainment corrected maximum likelihood approach for estimation using the resulting biased sample of subjects. In addition, we demonstrate that the efficiency of an outcome‐based sampling design relative to use of a simple random sample depends highly on the choice of outcome summary statistic used to direct sampling, and we show a natural link between the goals of the longitudinal regression model and corresponding desirable designs. Using data from the Childhood Asthma Management Program, where genetic information required retrospective ascertainment, we study a range of designs that examine lung function profiles over 4 years of follow‐up for children classified according to their genotype for the IL 13 cytokine.