bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodiversity along temperate forest succession
Authors: Hilmers Torben , Friess Nicolas , Bässler Claus , Heurich Marco , Brandl Roland , Pretzsch Hans , Seidl Rupert , Müller Jörg 
Published: July 2018

Abstract

The successional dynamics of forests—from canopy openings to regeneration, maturation, and decay—influence the amount and heterogeneity of resources available for forest‐dwelling organisms. Conservation has largely focused only on selected stages of forest succession (e.g., late‐seral stages). However, to develop comprehensive conservation strategies and to understand the impact of forest management on biodiversity, a quantitative understanding of how different trophic groups vary over the course of succession is needed.

We classified mixed mountain forests in Central Europe into nine successional stages using airborne LiDAR. We analysed α‐ and β‐diversity of six trophic groups encompassing approximately 3,000 species from three kingdoms. We quantified the effect of successional stage on the number of species with and without controlling for species abundances and tested whether the data fit the more‐individuals hypothesis or the habitat heterogeneity hypothesis. Furthermore, we analysed the similarity of assemblages along successional development.

The abundance of producers, first‐order consumers, and saprotrophic species showed a U‐shaped response to forest succession. The number of species of producer and consumer groups generally followed this U‐shaped pattern. In contrast to our expectation, the number of saprotrophic species did not change along succession. When we controlled for the effect of abundance, the number of producer and saproxylic beetle species increased linearly with forest succession, whereas the U‐shaped response of the number of consumer species persisted. The analysis of assemblages indicated a large contribution of succession‐mediated β‐diversity to regional γ‐diversity.

Synthesis and applications. Depending on the species group, our data supported both the more‐individuals hypothesis and the habitat heterogeneity hypothesis. Our results highlight the strong influence of forest succession on biodiversity and underline the importance of controlling for successional dynamics when assessing biodiversity change in response to external drivers such as climate change. The successional stages with highest diversity (early and late successional stages) are currently strongly underrepresented in the forests of Central Europe. We thus recommend that conservation strategies aim at a more balanced representation of all successional stages.
Livestock in diverse cropping systems improve weed management and sustain yields whilst reducing inputs
Authors: MacLaren Chloe , Storkey Jonathan , Strauss Johann , Swanepoel Pieter , Dehnen‐Schmutz Katharina 
Published: July 2018

Abstract

Intensive cropping systems select for a low diversity of weeds tolerant of chemical control, leading to persistent weed‐crop competition and declining biodiversity. Crop rotation can mitigate this by introducing variable filters on the weed community through increasing management diversity. In this study, we investigate the effect of integrating livestock into no‐till crop rotations to complement chemical weed control.

We analysed 12 years of weed seedbank data from a trial of eight rotation systems with different crop sequence diversities, of which four included grazed forage phases. Linear mixed models and ordination were used to assess how weed abundance, diversity, and community composition responded to management filters, defined in terms of levels of disturbance strength and diversity (grazing and herbicides), and resource availability and diversity (inorganic fertilizers, legumes, and manure).

Grazed rotation systems had less herbicide applied than ungrazed rotation systems, and had the lowest weed abundance and highest weed diversity. Herbicides and grazing apply contrasting selection pressures on weeds, and this combination was more effective in reducing weed pressure than increasing herbicide quantity or mode‐of‐action diversity. Lower resource availability and higher nitrogen source diversity in grazed systems may have further reduced weed abundance and promoted diversity.

Crop sequence diversity also reduced weed abundance and promoted weed diversity, indicating that variable crop‐weed interactions can enhance weed management. In addition, yields in the main cash crop (wheat) were highest where crop diversity was highest, regardless of whether the system contained grazed phases.

Synthesis and applications. Diverse rotation systems produced high yields, and the inclusion of grazed forage phases maintained these yields at lower applications of herbicides and fertilizers: integrated livestock can therefore improve the sustainability of no‐till systems. The role of grazing as a filter imposing a contrasting selection pressure to other weed control options could be further explored to improve weed management in different farming systems.
Climate change policy discontinuity and its effects on Australia's national electricity market
Authors: Simshauser Paul , Tiernan Anne 
Published: July 2018

AbstractAustralia's National Electricity Market (NEM) became unstable in 2016/2017 after 20 years of consistent performance. The South Australian grid collapsed on 28 September 2016 – Australia's first black system event since 1964. Wholesale prices in the region trebled to $120+/MWh; soon after Hazelwood power station announced its exit with just 5 months’ notice. The problem spread as prices elsewhere doubled to $89/MWh from a long‐run average of $42.50. The NEM is experiencing a supply‐side crisis. Consistent with the requirement to decarbonise the system, aged coal‐fired generators are exiting but decades of climate change policy discontinuity has frustrated the entry of new plant. Long‐dated capital‐intensive asset industries like electricity supply anticipate a conventional policy cycle. What they have experienced instead is consistent with garbage can theory. Policy clarity may be emerging for only the second time in two decades. As with the NEM, its durability will depend on cooperative federalism.
Vaginal prevalence of human papillomavirus infections in women with uterovaginal aplasia before and after laparoscopically assisted creation of a neovagina: a prospective epidemiological observational study
Authors: Rall KK , Schoenfisch B , Schoeller D , Stefanescu D , Koelle A , Henes M , Huebner M , Taran FA , Seeger H , Iftner A , Iftner T , Brucker SY 
Published: July 2018

ObjectiveTo study vaginal as opposed to cervical human papillomavirus (HPV) acquisition with regard to true prevalence, HPV types, and the role of co‐factors in virgins and after their sexual debut.DesignProspective epidemiological observational study.SettingUniversity hospital specialised in genital malformations.PopulationWomen diagnosed with Mayer–Rokitansky–Küster–Hauser syndrome (MRKHS) and undergoing neovaginoplasty between November 2011 and July 2017.MethodsThis is a prospective study including 186 women with MRKHS before and after sexual debut.Main outcome measuresConventional vaginal cytology and different HPV tests were performed at surgery and during routine gynaecological follow‐up 1, 3, 6 and ≥ 11 months after surgery and risk factors were documented.ResultsThe mean age of all women at surgery was 20.1 years (SD 5.4), mean body mass index (BMI) was 22.1 kg/m2 (SD 4.6). In 83 vaginal samples from 41 different women at least one of the HPV tests was positive. Thirty‐three different HPV types were detected. The prevalence of 41/186 = 22.0% as well as type distribution are comparable with those found in a young German female population. The overall rate of acquisition was clearly associated with sexual activity and smoking habits. Out of 367 Papanicolaou smears only six were abnormal with Pap IIID (MN II) and no obvious vaginal lesion was detected.ConclusionsVaginal HPV prevalence and HPV types in previously virgin women after creation of a neovagina are not different from the acquisition of cervical infections in the general population and is clearly associated with sexual activity and with smoking habits. However, abnormal Papanicolaou smears are rarely seen.Tweetable abstractVaginal HPV prevalence after creation of a neovagina is similar to that on the cervix in the general population.
VCAM‐1 upregulation accompanies muscle remodeling following resistance‐type exercise in Snell dwarf (Pit1dw/dw) mice
Authors: Rader Erik P. , Naimo Marshall A. , Ensey James , Baker Brent A. 
Published: July 2018

AbstractSnell dwarf mice (Pit1dw/dw) exhibit deficiencies in growth hormone, prolactin, and thyroid stimulating hormone. Besides being an experimental model of hypopituitarism, these mice are long‐lived (>40% lifespan extension) and utilized as a model of slowed/delayed aging. Whether this longevity is accompanied by a compromised quality of life in terms of muscular performance has not yet been characterized. In this study, we investigated nontrained and trained muscles 1 month following a general validated resistance‐type exercise protocol in 3‐month‐old Snell dwarf mice and control littermates. Nontrained Snell dwarf gastrocnemius muscles exhibited a 1.3‐fold greater muscle mass to body weight ratio than control values although muscle quality, maximum isometric torque normalized to muscle mass, and fatigue recovery were compromised. For control mice, training increased isometric torque (17%) without altering muscle mass. For Snell dwarf mice, isometric torque was unaltered by training despite decreased muscle mass that rendered muscle mass to body weight ratio comparable to control values. Muscle quality and fatigue recovery improved twofold and threefold, respectively, for Snell dwarf mice. This accompanied a fourfold increase in levels of vascular cell adhesion molecule‐1 (VCAM‐1), a mediator of progenitor cell recruitment, and muscle remodeling in the form of increased number of central nuclei, additional muscle fibers per unit area, and altered fiber type distribution. These results reveal a trade‐off between muscle quality and longevity in the context of anterior pituitary hormone deficiency and that resistance‐type training can diminish this trade‐off by improving muscle quality concomitant with VCAM‐1 upregulation and muscle remodeling.
Lost in virtual gaming worlds: Grit and its prognostic value for online game addiction
Authors: Borzikowsky Christoph , Bernhardt Fabian 
Published: July 2018

Background and ObjectivesThe personality construct grit is defined as the ability to be persistent in pursuit of long‐term goals in spite of challenges or obstacles. Grit is an emerging concept in positive psychology and has gained much attention because of its relevance for success and well‐being across different domains. The aim of the present study was to examine the prognostic value of grit for online game addiction.MethodsWe surveyed German speaking online gamers (N = 305: 193 males and 112 females, Mage = 28.44 years, SDage = 8.88) in an online cross‐sectional self‐report study. We measured grit with the German version of the Short Grit Scale (BISS‐8), online game addiction with the short version of the Game Addiction Scale (GAS), and participants’ age and gender.ResultsStructural equation modeling supported the higher‐order factor structure of grit in our sample (χ2[18] = 29.31, p < .05; CFI = .980; TLI = .969; RMSEA = .045; SRMR = .038). A logistic regression revealed that both grit (OR = 0.62, 95%CI [.42; .89], p < .05) as well as age (OR = .92, 95%CI [.88; .97], p < .01) significantly reduced the likelihood of being addicted to online games.Discussion and ConclusionsIn line with previous research on grit in patients with substance use disorders, we found grit to be a protective factor against online game addiction. We concluded that higher grit scores and older ages decrease the likelihood of being addicted to online games.Scientific SignificanceThis study provides initial support for the clinical relevance of grit for online game addiction. (Am J Addict 2018;27:433–438)
Donor sclera versus bovine pericardium as patch graft material in glaucoma implant surgery and the impact of a drainage suture
Authors: van Hoefen Wijsard Milo , Haan Michiel , Rietveld Eelco , van Rijn Laurentius J. 
Published: July 2018

AbstractPurposeTo compare the use of human donor sclera with bovine pericardium as patch graft material for a glaucoma drainage device (GDD), with respect to the incidence of tube exposure, and to study the role of a drainage suture.MethodsAll GDD surgeries between 2010 and 2014 performed at the VU Medical Center were examined in this comparative, retrospective cohort study. A total of 244 cases were included; 163 in the human donor sclera cohort and 81 in the bovine pericardium cohort with a median follow‐up of 31 and 36 months, respectively. The primary outcome measure was occurrence of tube exposure. Survival analysis for tube exposure was carried out and Kaplan–Meier curves compared. Secondary outcomes were postoperative intraocular pressure (IOP), number of glaucoma medications and the effect of a drainage suture.ResultsIn the bovine pericardium cohort, eleven (13.6%) eyes developed tube exposure compared to none in the human donor sclera cohort. Their Kaplan–Meier survival curves differed significantly from each other (χ² = 21.1, p < 0.001, log‐rank test). Mean IOP and number of glaucoma medications did not differ significantly between patch graft materials at three months of follow‐up. The use of a drainage suture directly lowered IOP after surgery in both cohorts. Within the bovine pericardium cohort, eyes with a drainage suture experienced more tube exposure, although this difference was not statistically significant (p = 0.09).ConclusionHuman donor sclera leads to less tube exposure than bovine pericardium. A drainage suture directly lowers IOP after surgery. With bovine pericardium, but not with donor sclera, exposure tends to be enhanced by a drainage suture.
Behavioural dysfunctions of 10‐year‐old children born extremely preterm associated with corticotropin‐releasing hormone expression in the placenta
Authors: Leviton Alan , Allred Elizabeth N. , Joseph Robert M. , O'Shea Thomas Michael , Majzoub Joseph , Kuban Karl C. K. ,   the ELGAN Study Investigators
Published: July 2018

AbstractAimTo evaluate the relationship between corticotropin‐releasing hormone (CRH) expression in the placenta and the risk of school‐related dysfunctions at the age of 10 years among children born extremely preterm (EP).MethodsCorticotropin‐releasing hormone expression was measured in the placenta of 761 EP children, who had the following assessments at the age of 10 years: Differential Ability Scales, Oral and Written Language Scales, the Wechsler Individual Achievement Test‐III, NEPSY‐II and the Child Symptom Inventory‐4. We evaluated whether lowest and highest quartiles of CRH mRNA were associated with undesirable scores on these assessments. With 272 evaluations, we would expect 14 to be significant at p < 0.05.ResultsOnly 16 associations were statistically significant. On the other hand, seven of these were social limitations among girls whose placenta CRH mRNA was in the top quartile. Adjusting for delivery indication or restricting the sample to one delivery indication group resulted in few differences.ConclusionOverall, placenta CRH mRNA concentrations in the top or bottom quartiles were not associated with increased risks of dysfunctions 10 years later. Girls whose placenta CRH expression was in the top quartile, however, were at increased risk of seven indicators/correlates of social limitations.
Clarifying the Associations between Mindfulness Meditation and Emotion: Daily High‐ and Low‐arousal Emotions and Emotional Variability
Authors: Jones Dusti R. , Graham‐Engeland Jennifer E. , Smyth Joshua M. , Lehman Barbara J. 
Published: July 2018

BackgroundResearch examining the effects of mindfulness meditation (MM) on emotion seldom considers differences by arousal level or emotion variability.MethodsIn the present study, 115 participants (64% Female, 72% White, Mage = 19.03) were randomly assigned to a brief MM intervention condition (n = 60) or a wait‐list control condition (n = 51). Participants in the MM condition were trained in MM and instructed to practice MM daily for one week. All participants provided daily diary reports of both higher‐ and lower‐arousal positive (PE) and negative (NE) emotions. Emotions were weighted by valence and arousal. Multilevel modeling was used to examine valence, arousal, and their interaction; multivariate regression was used to examine emotional variability.ResultsMore time spent meditating (but not the MM condition itself) was associated with increased lower arousal emotions, and exhibited a significant effect on the interaction between valence and arousal. Examination of individual emotion items suggested that more time meditating significantly predicted increased feelings of quiet and calm and marginally increased relaxation and sleepiness among participants, but did not predict any other emotions assessed in daily life. MM was not associated with emotional variability.ConclusionThese results may suggest that PE should be separated by arousal when examining the effects of MM interventions.
Absorbable barbed suture device for laparoscopic peritoneal closure after hernia repair via the transabdominal preperitoneal approach: A single‐center experience with 257 cases
Authors: Chihara Naoto , Suzuki Hideyuki , Sukegawa Makoto , Watanabe Masanori , Oyama Rina , Shimizu Takao , Uchida Eiji 
Published: July 2018

AbstractIntroductionThe laparoscopic transabdominal preperitoneal approach requires peritoneal closure and technically skilled knotting. We have started to use a barbed running suturing device (V‐Loc 180) without knotting for transabdominal preperitoneal repair of hernias. This study aimed to determine whether using V‐Loc 180 was safe and shortened the time for laparoscopic peritoneal closure.MethodsBetween December 2010 and February 2017, 3‐0 V‐Loc 180 and a multifilament absorbable running suture (3‐0 Vicryl) were used for three‐port transabdominal preperitoneal repair of inguinal hernia in 363 cases. Data including peritoneal closure time and the complications were retrospectively recorded.ResultsFactors identified as significantly prolonging the peritoneal closure time were the hernia side (P = 0.0269), the type of hernia (P = 0.001), the suture device used (P < 0.0001), and the surgeon's experience (P < 0.0001). Use of the barbed suture was associated with a significantly shorter peritoneal closure time than the multifilament suture (mean closure time: 10.2 and 12.7 min, respectively). While there were no postoperative complications in the barbed suture group, there were two cases (1.9%) of postoperative complications in the multifilament suture group (P = 0.0272).ConclusionWe demonstrated that the use of the barbed suturing device for laparoscopic peritoneal closure was safe and feasible.
A Robust Approach to Sample Size Calculation in Cancer Immunotherapy Trials with Delayed Treatment Effect
Authors: Ye Ting , Yu Menggang 
Published: July 2018

Summary
Immunotherapies are taking the center stage for cancer drug development and research. Many of these therapies, for example, immune checkpoint inhibitors, are known to have possible lag periods to achieve their full effects. Therefore, the proportional hazard assumption is violated when comparing survival curves in randomized clinical trials evaluating such therapies. Limited work exists in determining sample size to account for the lag period which is usually unknown. Assuming that the lag period is within some reasonable range, this article presents an approach to calculate sample size based on a maximin efficiency robust test. Both theoretical derivations and simulation results show the proposed approach can guarantee the desired power in worst case scenarios and often much more efficient than existing approaches. Application to a real trial design is also illustrated.
Model Assisted Sensitivity Analyses for Hidden Bias with Binary Outcomes
Authors: Nattino Giovanni , Lu Bo 
Published: July 2018

Summary
In medical and health sciences, observational studies are a major data source for inferring causal relationships. Unlike randomized experiments, observational studies are vulnerable to the hidden bias introduced by unmeasured confounders. The impact of unmeasured covariates on the causal effect can be assessed by conducting a sensitivity analysis. A comprehensive framework of sensitivity analyses has been developed for matching designs. Sensitivity parameters are introduced to capture the association between the missing covariates and the exposure or the outcome. Fixing sensitivity parameter values, it is possible to compute the bounds of the p-value of a randomization test on causal effects. We propose a model assisted sensitivity analysis with binary outcomes for the general 1:k matching design, which provides results equivalent to the conventional nonparametric approach in large sample. By introducing a conditional logistic outcome model, we substantially simplify the implementation and interpretation of the sensitivity analysis. More importantly, we are able to provide a closed form representation for the set of sensitivity parameters for which the maximum p-values are non-significant. This methodology can be easily extended to matching designs with multilevel treatments. We illustrate our method using a U.S. trauma care database to examine mortality difference between trauma care levels.
Estimating the Causal Effect of Treatment Regimes for Organ Transplantation
Authors: Boatman Jeffrey A. , Vock David M. 
Published: July 2018

Summary
Patients awaiting cadaveric organ transplantation face a difficult decision if offered a low-quality organ: accept the organ or remain on the waiting list and hope a better organ is offered in the future. A dynamic treatment regime (DTR) for transplantation is a rule that determines whether a patient should decline an offered organ. Existing methods can estimate the effect of DTRs on survival outcomes, but these were developed for applications where treatment is abundantly available. For transplantation, organ availability is limited, and existing methods can only estimate the effect of a DTR assuming a single patient follows the DTR. We show for transplantation that the effect of a DTR depends on whether other patients follow the DTR. To estimate the anticipated survival if the entire population awaiting transplantation were to adopt a DTR, we develop a novel inverse probability weighted estimator (IPCW) which re-weights patients based on the probability of following their transplant history in the counterfactual world in which all patients follow the DTR of interest. We estimate this counterfactual probability using hot deck imputation to fill in data that is not observed for patients who are artificially censored by IPCW once they no longer follow the DTR of interest. We show via simulation that our proposed method has good finite-sample properties, and we apply our method to a lung transplantation observational registry.
Biological Sensitivity to the Effects of Maternal Postpartum Depressive Symptoms on Children's Behavior Problems
Authors: Somers Jennifer A. , Luecken Linda J. , Spinrad Tracy L. , Crnic Keith A. 
Published: July 2018

Resting respiratory sinus arrhythmia (RSA) may confer infant susceptibility to the postpartum environment. Among infants with higher RSA, there may be a positive relation between depressive symptoms across the first 6 months postpartum (PPD) and later behavior problems, and toddlers’ dysregulation during mother–child interactions may partially explain the effects. Among a sample of low‐income Mexican‐American families, infant RSA (N = 322; 46% male) was assessed at 6 weeks of age; mothers (Mage = 27.8, SD = 6.5) reported PPD symptoms every 3 weeks from 6 to 24 weeks and infant behavior problems at 36 months. Dysregulation was observed at 24 months. PPD was positively associated with behavior problems only among infants with lower RSA; however, this relation was not mediated by dysregulation.