bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is salvage logging effectively dampening bark beetle outbreaks and preserving forest carbon stocks?
Authors: Dobor Laura , Hlásny Tomáš , Rammer Werner , Zimová Soňa , Barka Ivan , Seidl Rupert 
Published: September 2019

Abstract

Salvage logging is one of most frequently applied management responses to forest disturbances world‐wide. As forest disturbances are increasing, so too is the application of salvage logging, yet its effects on ecosystems remains incompletely understood. In the Norway spruce (Picea abies (L.) Karst.) forests of Europe, salvaging of windfelled trees is inter alia applied to reduce the risk of bark beetle outbreaks (mainly Ips typographus L.). By preventing further disturbances, salvage logging can conserve live tree carbon (C) in forest landscapes. At the same time salvage logging reduces C stocks in detrital pools via the extraction of disturbed trees, its net effect thus remains unclear.

We used the forest landscape model iLand to explore the effect of a wide range of salvaging intensities on (a) subsequent bark beetle outbreaks, and (b) landscape‐scale forest C stocks in a Norway spruce‐dominated production forest in Slovakia under past and future climatic conditions.

Climate change resulted in a two‐ to three‐fold increase in bark beetle disturbances throughout the 21st century in our simulations. We found that removing >95% of disturbed trees can effectively buffer the effect of increasing disturbances, dampening bark beetle infestations and increasing live tree C. Total ecosystem C followed a U‐shaped pattern over salvaging intensity, with highest values in no salvage and 100% salvage scenarios.

However, realistic rates of salvaging (<95% of disturbed trees detected and removed) had no significant effect on bark beetle dynamics and live tree C, and reduced the total ecosystem C stored in the landscape. Furthermore, the effect of reduced bark beetle disturbance under intensive salvaging was partly offset by increased wind disturbance.

Synthesis and applications. Clearing disturbed areas to prevent future disturbances from bark beetles and conserve live tree carbon should only be applied where very high salvaging rates are feasible (i.e. small and concentrated disturbances). Considering that changing disturbance regimes make high‐intensity salvaging increasingly challenging, alternative disturbance management approaches need to be developed.
Testing urban drivers of riparian woody vegetation composition in a precipitation‐limited system
Authors: Solins Joanna P. , Cadenasso Mary L. 
Published: September 2019

Abstract

In precipitation‐limited regions, where water availability is a key driver of vegetation patterns, altered hydrology in urban areas may have a particularly strong effect on riparian plant communities. Urban water inputs can create perennial flows in formerly intermittent streams, potentially providing a water subsidy to riparian plants during dry seasons. However, during rainy seasons, increased storm flow magnitudes in urban areas can cause stream channel incision and associated lowered water tables. Channel incision may reduce riparian soil moisture throughout the year and limit the effect of dry‐season stream flow.

We investigated whether channel incision and dry‐season stream flow were related to the composition of riparian vegetation communities along small streams in Sacramento, California, United States, and whether these two factors interacted. Sacramento has a Mediterranean climate with a long summer dry season. We sampled the riparian woody plant community along 66 stream reaches that created a gradient of channel incision severity across sites with and without dry‐season flow.

The riparian vegetation community was more strongly related to channel incision than dry‐season flow. The two factors did interact in relation to the overall community composition based on multivariate analyses, but we did not detect interactions in univariate generalized linear mixed models predicting specific components of the woody vegetation community, with the exception of large native oak trees. We found that wetland‐associated species and non‐native species both became less prevalent with increasing channel incision. Conversely, native upland oak trees became more prevalent with increasing incision, although large oak trees only showed this pattern along flowing streams. Wetland‐associated seedlings were almost exclusively found along flowing streams.

Synthesis. Our findings suggest that channel incision is a key driver of riparian woody vegetation composition. Although the effects of dry‐season flow were less pronounced, urban water subsidies may be essential for the establishment of wetland‐associated trees along historically intermittent streams. Varied hydrological conditions in precipitation‐limited cities are associated with divergent assemblages of woody species in riparian zones.
Genome‐resolved metagenomics and metatranscriptomics reveal niche differentiation in functionally redundant microbial communities at deep‐sea hydrothermal vents
Authors: Galambos David , Anderson Rika E. , Reveillaud Julie , Huber Julie A. 
Published: October 2019

SummaryThe structure and function of microbial communities inhabiting the subseafloor near hydrothermal systems are influenced by fluid geochemistry, geologic setting and fluid flux between vent sites, as well as biological interactions. Here, we used genome‐resolved metagenomics and metatranscriptomics to examine patterns of gene abundance and expression and assess potential niche differentiation in microbial communities in venting fluids from hydrothermal vent sites at the Mid‐Cayman Rise. We observed similar patterns in gene and transcript abundance between two geochemically distinct vent fields at the community level but found that each vent site harbours a distinct microbial community with differing transcript abundances for individual microbial populations. Through an analysis of metabolic pathways in 64 metagenome‐assembled genomes (MAGs), we show that MAG transcript abundance can be tied to differences in metabolic pathways and to potential metabolic interactions between microbial populations, allowing for niche‐partitioning and divergence in both population distribution and activity. Our results illustrate that most microbial populations have a restricted distribution within the seafloor, and that the activity of those microbial populations is tied to both genome content and abiotic factors.
Where next for understanding race/ethnic inequalities in severe mental illness? Structural, interpersonal and institutional racism
Authors: Nazroo James Y. , Bhui Kamaldeep S. , Rhodes James 
Published: September 2019

AbstractIn this article we use the example of race/ethnic inequalities in severe mental illness to demonstrate the utility of a novel integrative approach to theorising the role of racism in generating inequality. Ethnic minority people in the UK are at much greater risk than White British people of being diagnosed with a severe – psychosis related – mental illness, and this is particularly the case for those with Black Caribbean or Black African origins. There is entrenched dispute about how we might understand the drivers of this inequality. To address this dispute we build on, and to a certain extent refine, established approaches to theorising structural and institutional racism, and integrate this within a theoretical framework that also incorporates racist/discriminatory interactions (interpersonal racism). We argue that this provides a conceptually robust and thorough analysis of the role of inter‐related dimensions of racism in shaping risks of severe mental illness, access to care, and policy and practice responses. This analysis carries implications for a broader, but integrated, understanding of the fundamental drives of race/ethnic inequalities in health and for an anti‐racism public health agenda.
Increased Sensitivity of Focused Cardiac Ultrasound for Pulmonary Embolism in Emergency Department Patients With Abnormal Vital Signs
Authors: Daley James I. , Dwyer Kristin H. , Grunwald Zachary , Shaw Daniel L. , Stone Michael B. , Schick Alexandra , Vrablik Michael , Kennedy Hall M. , Hall Jane , Liteplo Andrew S. , Haney Rachel M. , Hun Nancy , Liu Rachel , Moore Chris L. 
Published: September 2019

AbstractBackgroundFocused cardiac ultrasound (FOCUS) is insensitive for pulmonary embolism (PE). Theoretically, when a clot is large enough to cause vital sign abnormalities, it is more likely to show signs of right ventricular dysfunction on FOCUS, although this has not been well quantified. A rapid bedside test that could quickly and reliably exclude PE in patients with abnormal vital signs could be of high utility in emergency department (ED) patients. We hypothesized that in patients with tachycardia or hypotension, the sensitivity of FOCUS for PE would increase substantially.MethodsWe performed a prospective observational multicenter cohort study involving a convenience sample of patients from six urban academic EDs. Patients suspected to have PE with tachycardia (heart rate [HR] ≥ 100 beats/min) or hypotension (systolic blood pressure [sBP] < 90 mm Hg) underwent FOCUS before computed tomography angiography (CTA). FOCUS included assessment for right ventricular dilation, McConnell's sign, septal flattening, tricuspid regurgitation, and tricuspid annular plane systolic excursion. If any of these were abnormal, FOCUS was considered positive, while if all were normal, FOCUS was considered negative. We a priori planned a subgroup analysis of all patients with a HR ≥ 110 beats/min (regardless of their sBP). We then determined the diagnostic test characteristics of FOCUS for PE in the entire patient population and in the predefined subgroup, based on CTA as the criterion standard. Inter‐rater reliability of FOCUS was determined by blinded review of images by an emergency physician with fellowship training in ultrasound.ResultsA total of 143 subjects were assessed for enrollment and 136 were enrolled; four were excluded because they were non–English‐speaking and three because of inability to obtain any FOCUS windows. The mean (±SD) age of enrolled subjects was 56 (±7) years, mean (±SD) HR was 114 (±12) beats/min, and 37 (27.2%) subjects were diagnosed with PE on CTA. In all subjects, FOCUS was 92% (95% confidence interval [CI] = 78% to 98%) sensitive and 64% specific (95% CI = 53% to 73%) for PE. In the subgroup of 98 subjects with a HR ≥ 110 beats/min, FOCUS was 100% sensitive (95% CI = 88% to 100%) and 63% specific (95% CI = 51% to 74%) for PE. There was substantial interobserver agreement for FOCUS (κ = 1.0, 95% CI = 0.31 to 1.0).ConclusionsA negative FOCUS examination may significantly lower the likelihood of the diagnosis of PE in most patients who are suspected of PE and have abnormal vital signs. This was especially true in those patients with a HR ≥ 110 beats/min. Our results suggest that FOCUS can be an important tool in the initial evaluation of ED patients with suspected PE and abnormal vital signs.
Mortality of seabirds migrating across the tropical Atlantic in relation to oceanographic processes
Authors: Tavares D. C. , Moura J. F. , Merico A. , Siciliano S. 
Published: September 2019

AbstractLarge‐scale climatic processes such as the El Niño‐Southern Oscillation (ENSO) can have severe effects on the survival of seabirds in their breeding regions. However, there is a fundamental lack of understanding about how environmental factors are related to the mortality of these organisms in non‐breeding areas of the tropics. We investigate here the direct and indirect effects of ENSO and oceanographic variables on the mortality of three migratory seabird species targeted by conservation programmes focused on human impacts: the Atlantic yellow‐nosed albatross Thalassarche chlororhynchos, the Magellanic penguin Spheniscus magellanicus and the Manx shearwater Puffinus puffinus in a non‐breeding area in Brazil, tropical Atlantic. We find that the intensification of ENSO increases the mortality of Manx shearwaters by enhancing the local storm activity. The mortality of Atlantic yellow‐nosed albatrosses and Magellanic penguins is also related to a local increase in storm activity but regardless of the ENSO signature. Increased mortality of Magellanic penguins is observed when biological productivity falls below the annual average (1.7 mg m−3). Adverse climatic conditions are highly deleterious for migratory seabirds and single storm episodes can cause massive deaths, thus exacerbating population declines. We argue that conservation and management strategies for migratory seabirds studied here should not only focus on direct human impacts but should also consider mitigating the effects of climate variability.
Adult neurogenesis in the mammalian dentate gyrus
Authors: Abbott Louise C. , Nigussie Fikru 
Published: October 2019

AbstractEarlier observations in neuroscience suggested that no new neurons form in the mature central nervous system. Evidence now indicates that new neurons do form in the adult mammalian brain. Two regions of the mature mammalian brain generate new neurons: (a) the border of the lateral ventricles of the brain (subventricular zone) and (b) the subgranular zone (SGZ) of the dentate gyrus of the hippocampus. This review focuses only on new neuron formation in the dentate gyrus of the hippocampus. During normal prenatal and early postnatal development, neural stem cells (NSCs) give rise to differentiated neurons. NSCs persist in the dentate gyrus SGZ, undergoing cell division, with some daughter cells differentiating into functional neurons that participate in learning and memory and general cognition through integration into pre‐existing neural networks. Axons, which emanate from neurons in the entorhinal cortex, synapse with dendrites of the granule cells (small neurons) of the dentate gyrus. Axons from granule cells synapse with pyramidal cells in the hippocampal CA3 region, which send axons to synapse with CA1 hippocampal pyramidal cells that send their axons out of the hippocampus proper. Adult neurogenesis includes proliferation, differentiation, migration, the death of some newly formed cells and final integration of surviving cells into neural networks. We summarise these processes in adult mammalian hippocampal neurogenesis and discuss the roles of major signalling molecules that influence neurogenesis, including neurotransmitters and some hormones. The recent controversy raised concerning whether or not adult neurogenesis occurs in humans also is discussed.
Potential use of stem cells for fertility preservation
Authors: Gauthier‐Fisher A. , Kauffman A. , Librach C. L. 
Published: September 2019

AbstractBackgroundInfertility and gonadal dysfunction can result from gonadotoxic therapies, environmental exposures, aging, or genetic conditions. In men, non‐obstructive azoospermia (NOA) results from defects in the spermatogenic process that can be attributed to spermatogonial stem cells (SSC) or their niche, or both. While assisted reproductive technologies and sperm banking can enable fertility preservation (FP) in men of reproductive age who are at risk for infertility, FP for pre‐pubertal patients remains experimental. Therapeutic options for NOA are limited. The rapid advance of stem cell research and of gene editing technologies could enable new FP options for these patients. Induced pluripotent stem cells (iPSC), SSC, and testicular niche cells, as well as mesenchymal stromal cells (aka medicinal signaling cells, MSCs), have been investigated for their potential use in male FP strategies.ObjectiveHere, we review the benefits and challenges for three types of stem cell‐based approaches under investigation for male FP, focusing on the role that promising sources of MSC derived from human umbilical cord, specifically human umbilical cord perivascular cells (HUCPVC), could fulfill. These approaches are as follows: 1. isolation and ex vivo expansion of autologous SSC for in vivo transplantation or in vitro spermatogenesis; 2. in vitro differentiation toward germ cell and testicular somatic cell lineages using autologous SSC, or stem cells such iPSC or MSC; and 3. protection or regeneration of the spermatogenic niche after gonadotoxic insults in vivo.ConclusionOur studies suggest that HUCPVC are promising sources of cells that could be utilized in multiple aspects of male FP strategies.
Triage of low‐grade squamous intraepithelial lesions using human papillomavirus messenger ribonucleic acid tests—A prospective population‐based register study
Authors: Reinholdt Kristian , Juul Kirsten E. , Dehlendorff Christian , Munk Christian , Kjær Susanne K. , Thomsen Louise T. 
Published: September 2019

AbstractIntroductionThe optimal clinical management of women diagnosed with low‐grade squamous intraepithelial lesions (LSIL) during cervical cancer screening remains unclear. In this prospective cohort study, we compared the clinical performance of two human papillomavirus (HPV) mRNA tests for triage of women with LSIL in Denmark.Material and methodsIn a nationwide pathology register, we identified women aged 23‐65 years with LSIL during 2008‐2012. We included women tested for HPV mRNA with the PreTect HPV Proofer test for five high‐risk HPV types (n = 2176) or the Aptima assay for 14 high‐risk HPV types (n = 426). Subsequent histological diagnoses of cervical intraepithelial neoplasia grades 2, 3 or cancer (CIN2+) were identified in the register. We calculated the sensitivity and specificity for CIN2+ at 18 and 36 months of follow up, and the cumulative incidence of CIN2+ among women testing positive and negative, overall and by age (23‐29, 30‐39, 40‐65 years).ResultsThe proportion of women with a positive mRNA test at baseline was higher in women tested with Aptima (66.7%) than in women tested with Proofer (42.8%). After 18 months, Aptima had higher sensitivity for CIN2+ than Proofer (98% [95% CI 94% to 100%] vs 85% [95% CI 82% to 88%]), whereas Proofer showed higher specificity than Aptima (67% [95% CI 64% to 70%]) vs (40% [95% CI 33% to 46%]). Aptima had particularly low specificity in women aged <40 years (23‐29: 19% [95% CI 5% to 36%]; 30‐39: 10% [95% CI 0% to 33%]). The 36‐month cumulative incidence of CIN2+ was higher in Proofer positive (54.3% [95% CI 50.9% to 57.8%]) than in Aptima positive women (37.6% [95% CI 31.2% to 44.8%]). In women with a negative mRNA test, the 36‐month cumulative incidences of CIN2+ were 13.1% (95% CI 10.8% to 15.8%) and 5.9% (95% CI 1.7% to 19.0%) for Proofer and Aptima, respectively.ConclusionsIn women with LSIL, Aptima had high sensitivity for CIN2+, but low specificity, especially in women aged <40 years. The Proofer test may be useful to limit immediate colposcopy referrals in younger women with LSIL, but given its low sensitivity and negative predictive value, Proofer negative women must be followed with repeat cytology.
Review on long‐term non‐renal complications of childhood nephrotic syndrome
Authors: Lee Jiwon M. , Kronbichler Andreas , Shin Jae Il , Oh Jun 
Published: September 2019

AbstractBackgroundNephrotic syndrome (NS) is the most common glomerular childhood disease. A body of literature has described the long‐term renal prognosis of childhood‐onset idiopathic NS. However, the nonrenal outcomes have not been studied as much.AimWe aimed to discuss the long‐term non‐renal outcomes of childhood NS, highlighting studies with a follow‐up period of more than 10 years.ResultsWe reviewed the literature and found that a number of immunosuppressive agents have stopped inflammation, stabilised the podocyte cytoskeleton and reduce proteinuria. However, prolonged treatment has frequently been associated with a high risk of renal and non‐renal complications in patients with a complicated disease course, defined as frequent relapses or steroid dependency. Non‐renal complications may include impaired longitudinal growth and pubertal development, undesirable fertility outcomes, ocular complications, bone mineral diseases and potential malignancies.ConclusionThis review discusses and summarises the non‐renal outcomes of idiopathic childhood NS.
Adjusting for time‐varying confounders in survival analysis using structural nested cumulative survival time models
Authors: Seaman Shaun , Dukes Oliver , Keogh Ruth , Vansteelandt Stijn 
Published: September 2019

AbstractAccounting for time‐varying confounding when assessing the causal effects of time‐varying exposures on survival time is challenging. Standard survival methods that incorporate time‐varying confounders as covariates generally yield biased effect estimates. Estimators using weighting by inverse probability of exposure can be unstable when confounders are highly predictive of exposure or the exposure is continuous. Structural nested accelerated failure time models (AFTMs) require artificial recensoring, which can cause estimation difficulties. Here, we introduce the structural nested cumulative survival time model (SNCSTM). This model assumes that intervening to set exposure at time to zero has an additive effect on the subsequent conditional hazard given exposure and confounder histories when all subsequent exposures have already been set to zero. We show how to fit it using standard software for generalized linear models and describe two more efficient, double robust, closed‐form estimators. All three estimators avoid the artificial recensoring of AFTMs and the instability of estimators that use weighting by the inverse probability of exposure. We examine the performance of our estimators using a simulation study and illustrate their use on data from the UK Cystic Fibrosis Registry. The SNCSTM is compared with a recently proposed structural nested cumulative failure time model, and several advantages of the former are identified.
Perceived quality of instruction: The relationship among indicators of students’ basic needs, mastery goals, and academic achievement
Authors: Theis Désirée , Sauerwein Markus , Fischer Natalie 
Published: September 2019

BackgroundStudents’ mastery goals are positively related to adaptive learning behaviour. Moreover, these goals often mediate the relation between perceived classroom characteristics and academic achievement. Research generally shows a decline of academic achievement and mastery goals after transition to middle school. Creating a learning environment at middle school according to students’ basic needs for autonomy, competence, and social relatedness might help to reduce these declines. However, little is known about the relationship between perceived fulfilment of needs, mastery goals, and academic achievement.AimsWe investigate the relationship between indicators of students’ perceived fulfilment of needs and their graded performance to determine whether the connection is indirect via mastery goals.SampleWe surveyed 2,105 students during the first year in middle school.MethodsWe assessed the amount of the students’ perceived autonomy, recognition of competence and support from the teacher (as indicators of competence and social relatedness) in class, their mastery goals, and their grades. Multilevel models were calculated.ResultsPerceived fulfilment of needs correlated significantly with mastery goals and graded performance. Mastery goals predicted graded performance; however, when perceived fulfilment of needs and mastery goals were analysed simultaneously, the correlation between mastery goals and graded performance was no longer significant. There was no indirect relation between perceived fulfilment of needs and graded performance via mastery goals.ConclusionsResults indicate that creating the learning environment according to the students’ basic needs is positively related to their mastery goals and graded performance during the first year at middle school.