bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ants, fire, and bark traits affect how African savanna trees recover following damage
Authors: Wigley Benjamin J. , Coetsee Corli , Kruger Laurence M. , Ratnam Jayashree , Sankaran Mahesh 
Published: July 2019

AbstractBark damage resulting from elephant feeding is common in African savanna trees with subsequent interactions with fire, insects, and other pathogens often resulting in tree mortality. Yet, surprisingly little is known about how savanna trees respond to bark damage. We addressed this by investigating how the inner bark of marula (Sclerocarya birrea), a widespread tree species favoured by elephants, recovers after bark damage. We used a long‐term fire experiment in the Kruger National Park to measure bark recovery with and without fire. At 24 months post‐damage, mean wound closure was 98, 92, and 72%, respectively, in annual and biennial burns and fire‐exclusion treatments. Fire exclusion resulted in higher rates of ant colonization of bark wounds, and such ant colonization resulted in significantly lower bark recovery. We also investigated how ten common savanna tree species respond to bark damage and tested for relationships between bark damage, bark recovery, and bark traits while accounting for phylogeny. We found phylogenetic signal in bark dry matter content, bark N and bark P, but not in bark thickness. Bark recovery and damage was highest in species which had thick moist inner bark and low wood densities (Anacardiaceae), intermediate in species which had moderate inner bark thickness and wood densities (Fabaceae) and lowest in species which had thin inner bark and high wood densities (Combretaceae). Elephants prefer species with thick, moist inner bark, traits that also appear to result in faster recovery rates.
Evaluation of the antitumor mechanism of antibody‐drug conjugates against tissue factor in stroma‐rich allograft models
Authors: Tsumura Ryo , Manabe Shino , Takashima Hiroki , Koga Yoshikatsu , Yasunaga Masahiro , Matsumura Yasuhiro 
Published: July 2019

AbstractTissue factor (TF) is known to be overexpressed in various cancers including pancreatic cancer. The upregulation of TF expression has been observed not only in tumor cells, but also in tumor stromal cells. Because of the potential of TF as a delivery target, several studies investigated the effectiveness of Ab‐drug conjugates (ADCs) against TF for cancer therapy. However, it is still unclear whether anti‐TF ADC can exert toxicity against both tumor cells and tumor stromal cells. Here, we prepared ADC using a rat anti‐mouse TF mAb (clone.1157) and 2 types of in vivo murine pancreatic cancer models, one s.c. and other orthotopic with an abundant tumor stroma. We also compared the feasibility of bis‐alkylating conjugation (bisAlk) with that of conventional maleimide‐based conjugation (MC). In the s.c. models, anti‐TF ADC showed greater antitumor effects than control ADC. The results also indicated that the bisAlk linker might be more suitable than the MC linker for cancer treatments. In the orthotopic model, anti‐TF ADC showed greater in vivo efficacy and more extended survival time control ADC. Treatment with anti‐TF ADC (20 mg/kg, three times a week) did not affect mouse body weight changes in any in vivo experiment. Furthermore, immunofluorescence staining indicated that anti‐TF ADC delivered agents not only to TF‐positive tumor cells, but also to TF‐positive tumor vascular endothelial cells and other tumor stromal cells. We conclude that anti‐TF ADC should be a selective and potent drug for pancreatic cancer therapy.
Does phenotypic plasticity initiate developmental bias?
Authors: Parsons Kevin J. , McWhinnie Kirsty , Pilakouta Natalie , Walker Lynsey 
Published: July 2019

AbstractThe generation of variation is paramount for the action of natural selection. Although biologists are now moving beyond the idea that random mutation provides the sole source of variation for adaptive evolution, we still assume that variation occurs randomly. In this review, we discuss an alternative view for how phenotypic plasticity, which has become well accepted as a source of phenotypic variation within evolutionary biology, can generate nonrandom variation. Although phenotypic plasticity is often defined as a property of a genotype, we argue that it needs to be considered more explicitly as a property of developmental systems involving more than the genotype. We provide examples of where plasticity could be initiating developmental bias, either through direct active responses to similar stimuli across populations or as the result of programmed variation within developmental systems. Such biased variation can echo past adaptations that reflect the evolutionary history of a lineage but can also serve to initiate evolution when environments change. Such adaptive programs can remain latent for millions of years and allow development to harbor an array of complex adaptations that can initiate new bouts of evolution. Specifically, we address how ideas such as the flexible stem hypothesis and cryptic genetic variation overlap, how modularity among traits can direct the outcomes of plasticity, and how the structure of developmental signaling pathways is limited to a few outcomes. We highlight key questions throughout and conclude by providing suggestions for future research that can address how plasticity initiates and harbors developmental bias.
Contrasting forms of competition set elevational range limits of species
Authors: Chan Shih‐Fan , Shih Wei‐Kai , Chang An‐Yu , Shen Sheng‐Feng , Chen I‐Ching 
Published: July 2019

AbstractHow abiotic and biotic factors constrain distribution limits at the harsh and benign edges of species ranges is hotly debated, partly because macroecological experiments testing the proximate causes of distribution limits are scarce. It has long been recognized – at least since Darwin’sOn the Origin of Species– that a harsh climate strengthens competition and thus sets species range limits. Using thorough field manipulations along a large elevation gradient, we show the mechanisms by which temperature determines competition type, resulting in a transition from interference to exploitative competition from the lower to the upper elevation limits in burying beetles (Nicrophorus nepalensis). This transition is an example of Darwin’s classic hypothesis that benign climates favor direct competition for highly accessible resources while harsh climates result in competition through resources of high rivalry. We propose that identifying the properties of these key resources will provide a more predictive framework to understand the interplay between biotic and abiotic factors in determining geographic range limits.
Keystone mutualism influences forest tree growth at a landscape scale
Authors: Clark Robert Emerson , Gutierrez Illan Javier , Comerford Mattheau S. , Singer Michael S. 
Published: July 2019

AbstractInteractions between ants and phloem‐feeding herbivores are characterised as a keystone mutualism because they restructure arthropod communities and generate trophic cascades. Keystone interactions in terrestrial food webs are hypothesised to depend on herbivore community structure and bottom‐up effects on plant growth. Here, we tested this prediction at a landscape scale with a long‐term ant‐exclusion experiment on hickory saplings in the context of spatial variation in herbivore community structure and habitat quality. We quantified top‐down effects of ants, herbivore communities as well as abiotic factors impacting hickory shoot growth. We found that ants influenced shoot growth via strong, context‐dependent, compensatory effects, with clear cascading benefits only when phloem‐feeders were present and chewing herbivore abundance was high. By contrast, while several landscape variables predicted hickory growth, they did not mediate the strength of cascading effects of ants. These results suggest that ant/sap‐feeder mutualisms may regulate forest productivity by mediating effects of multiple herbivore guilds.
Addressing a real‐life problem: treatment with intravenous thrombolysis and mechanical thrombectomy in acute stroke patients with an extended time window beyond 4.5 h based on computed tomography perfusion imaging
Authors: Feil K. , Reidler P. , Kunz W. G. , Küpper C. , Heinrich J. , Laub C. , Müller K. , Vöglein J. , Liebig T. , Dieterich M. , Kellert L. 
Published: July 2019

Background and purposeAcute ischemic stroke treatment with intravenous thrombolysis (IVT) is restricted to a time window of 4.5 h after known or presumed onset. Recently, magnetic resonance imaging‐guided treatment decision‐making in wake‐up stroke (WUS) was shown to be effective. The aim of this study was to determine the safety and outcome of IVT in patients with a time window beyond 4.5 h selected by computed tomography perfusion (CTP) imaging.MethodsWe analyzed all consecutive patients last seen well beyond 4.5 h after stroke onset treated with IVT based on CTP between January 2015 and October 2018. CTP was visually assessed to estimate the mismatch between cerebral blood flow and cerebral blood volume maps. Early infarct signs were documented according to Alberta Stroke Program Early CT Score (ASPECTS). Safety data were obtained for mortality and symptomatic intracerebral hemorrhage (sICH). Follow‐up was assessed with the modified Rankin Scale (mRS).ResultsA total of 70 patients fulfilled the inclusion criteria (mean age ± SD 77.6 ± 11.5 years, 50.0% female). Median National Institutes of Health Stroke Scale score on admission was 8.0 [interquartile range (IQR), 4–14]. The most frequent reasons for an extended time window were WUS (60.0%) and delayed hospital admission (27.1%). Median time from last seen well to IVT was 11.4 h. Median ASPECTS was 10 (IQR, 9–10) and CTP mismatch 90% (IQR, 80%–100%). A total of 24 patients (34.3%) underwent additional mechanical thrombectomy. sICH occurred in four patients (5.7%). At follow‐up, 49.3% had an mRS score of 0–2 and 22.4% had an mRS score of 0–1.ConclusionsIn patients presenting in an extended time window beyond 4.5 h, IVT treatment with decision‐making based on CTP might be a safe procedure. Further evaluation in clinical trials is needed.
Adaptive limitations of white spruce populations to drought imply vulnerability to climate change in its western range
Authors: Sang Zihaohan , Sebastian‐Azcona Jaime , Hamann Andreas , Menzel Annette , Hacke Uwe 
Published: July 2019

AbstractA cost‐effective climate change adaptation strategy for the forestry sector is to move seed sources to more northern and higher elevation planting sites as part of ongoing reforestation programs. This is meant to match locally adapted populations with anticipated environments, but adaptive traits do not always show population differences suitable to mitigate climate change impacts. For white spruce, drought tolerance is a critical adaptive trait to prevent mortality and productivity losses. Here, we use a 40‐year‐old provenance experiment that has been exposed to severe drought periods in 1999 and 2002 to retrospectively investigate drought response and the adaptive capacity of white spruce populations across their boreal range. Relying on dendrochronological analysis under experimentally controlled environments, we evaluate population differences in resistance, resilience, and recovery to these extreme events. Results showed evidence for population differentiation in resistance and recovery parameters, but provenances conformed to approximately the same growth rates under drought conditions and had similar resilience metrics. The lack of populations with better growth rates under drought conditions is contrary to expectations for a wide‐ranging species with distinct regional climates. Populations from the wettest environments in the northeastern boreal were surprisingly drought‐tolerant, suggesting that these populations would readily resist water deficits projected for the 2080s, and supporting the view that northeastern Canada will provide a refugium for boreal species under climate change. The findings also suggest that white spruce is sensitive to growth reductions under climate change in the western boreal. The study highlights that population differentiation in adaptive capacity is species‐ and trait‐specific, and we provide a counterexample for drought tolerance traits, where assisted migration prescriptions may be ineffective to mitigate climate change impacts. For resource managers and policy makers, we provide maps where planning for widespread declines of boreal white spruce forests may be unavoidable.
Temporal changes in fish diversity in lotic and lentic environments along a reservoir cascade
Authors: Loures Raquel Coelho , Pompeu Paulo Santos 
Published: July 2019

Abstract

Long‐term modifications in hydrological conditions due to river damming result in varied effects on fish diversity, which can be stronger in a reservoir cascade. Therefore, we assessed changes in fish diversity over a 28‐year period, in a series of reservoirs along the Araguari River Basin, a Neotropical drainage in Brazil, in both lentic environments (reservoirs) and the lotic stretches between them.

We used linear mixed models to assess long‐term changes in fish diversity. Diversity was measured as α diversity (fish species richness) and β diversity (Jaccard's and Raup–Crick's dissimilarity index). Beta diversity was then partitioned into turnover (species replacement) and nestedness (species loss). To understand fish species replacement along the cascade, we modelled turnover with four covariates: age, richness of native and non‐native fish species, and longitudinal position of sampling site along the cascade.

The reduction of total richness and the increase in non‐native richness were related to reservoir age. These effects were similar in both lotic and lentic environments, with no significant difference between them. We also observed a decrease in native fish richness over time, with a slight tendency for lentic environments to lose more species than lotic environments.

Dissimilarity in fish assemblage increased over time and β Raup–Crick results corroborated those derived from β Jaccard, yielding similar significant temporal trends. Changes in fish species composition occurred predominantly due to turnover, compared to nestedness. We observed a greater species loss in reservoirs, suggesting that the transformation from a lotic environment into a lentic had greater impact on fish assemblages than the flow regulation of the lotic stretches downstream of the dams. Our results suggest that species replacement can be explained mainly by the increase of non‐native fish richness, followed by the longitudinal position along the cascade in an upstream–downstream direction, and reservoir age.

This study reveals that, even after 2 decades of monitoring, we still observe important changes in fish assemblages, demonstrating the importance of long‐term monitoring to assess biodiversity. Our findings reinforce the importance of long‐term fish monitoring schemes for the investigation of the effects of non‐native fish species on native fish assemblages.
Happy Jack Uraninite: A New Reference Material for High Spatial Resolution Analysis of U‐Rich Matrices
Authors: Dorais Corinne , Simonetti Antonio , Corcoran Loretta , Spano Tyler L. , Burns Peter C. 
Published: July 2019

There is currently a lack of well‐characterised matrix‐matched reference materials (RMs) for forensic analysis of U‐rich materials at high spatial resolution. This study reports a detailed characterisation of uraninite (nominally UO2+x) from the Happy Jack Mine (UT, USA). The Happy Jack uraninite can be used as a RM for the determination of rare earth element (REE) mass fractions in nuclear materials, which provide critical information for source attribution purposes. This investigation includes powder X‐ray diffraction (pXRD) data, as well as major, minor and trace element abundances determined using a variety of micro‐analytical techniques. The chemical signature of the uraninite was investigated at the macro (cm)‐scale with micro‐X‐ray fluorescence (µXRF) mapping and at high spatial resolution (tens of micrometre scale) using electron probe microanalysis (EPMA) and laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) analyses. Based on EPMA results, the uraninite is characterised by homogeneous UO2 and CaO contents of 91.57 ± 1.49% m/m (2s uncertainty) and 2.70 ± 0.38% m/m (2s), respectively. Therefore, CaO abundances were used as the internal standard when conducting LA‐ICP‐MS analyses. Overall, the major element and REE compositions are homogeneous at both the centimetre and micrometre scales, allowing this material to be used as a RM for high spatial resolution analysis of U‐rich samples.
Assessing dinner meals offered at home among preschoolers from low‐income families with the Remote Food Photography Method
Authors: Bekelman Traci A. , Bellows Laura L. , McCloskey Morgan L. , Martin Corby K. , Johnson Susan L. 
Published: July 2019

SummaryBackgroundThe high prevalence of obesity among preschoolers may be partially explained by the type and quantity of foods offered by parents and left unconsumed by preschoolers.Objectives(a) To compare foods offered and consumed at dinner to the Dietary Guidelines for Americans (DGAs) and the Child and Adult Care Food Program (CACFP) standards and (b) to examine the types, quantities, and nutrient composition of foods offered to and consumed by preschoolers and their plate waste.MethodsParticipants were recruited from six Head Start/preschool centres. The Remote Food Photography Method was used to document dinner meals over 1 week (n = 153 meals). Energy and nutrients for foods offered, consumed, and plate waste were calculated. Foods offered and consumed were compared with the DGAs and CACFP standards.ResultsFoods and beverages offered at dinner equaled 506 kcal, which is 36% of the DGA‐recommended total daily energy intake. Meals offered and consumed were high in fat and sodium and low in fibre. Adherence to CACFP standards was low for fruits (25%) and milk (2%) and moderate for vegetables (63%). Mean plate waste (29%) was similar across food types.ConclusionsOpportunities exist to improve preschoolers' adherence to the DGAs and CACFP standards by enhancing the quality of dinner meals offered to them.
The behaviour of some antihypertension drugs on human serum paraoxonase-1: an important protector enzyme against atherosclerosis
Authors: Demir Yeliz 
Published: July 2019

Abstract

Objectives
Paraoxonase-1 (PON1) enzyme is related to high-density lipoprotein (HDL), which is calcium dependent. It has essential roles such as protecting LDL against oxidation and detoxification of highly toxic substances. It is a significant risk to reduce the levels of this enzyme in patients with diabetes mellitus, cardiovascular diseases, hyperthyroidism and chronic renal failure.

Methods
Here, it was reported that the purification of human serum PON1 using straightforward methods and determination of the interactions between some antihypertension drugs and the enzyme.

Key finding
It was found that these drugs exhibit potential inhibitor properties for human serum PON1 with IC50 values in the range of 131.40–369.40 μm and Ki values in the range of 56.24 ± 6.75–286.74 ± 28.28 μm. These drugs showed different inhibition mechanisms. It was determined that midodrine and nadolol were exhibited competitive inhibition, but atenolol and pindolol were exhibited non-competitive inhibition.

Conclusion
Usage of these drugs would be hazardous in some cases.
Unique sleep‐stage transitions determined by obstructive sleep apnea severity, age and gender
Authors: Wächter Marcel , Kantelhardt Jan W. , Bonsignore Maria R. , Bouloukaki Izolde , Escourrou Pierre , Fietze Ingo , Grote Ludger , Korzybski Damian , Lombardi Carolina , Marrone Oreste , Paranicova Ivana , Pataka Athanasia , Ryan Silke , Schiza Sophia E. , Sliwinski Pawel , Steiropoulos Paschalis , Verbraecken Johan , Penzel Thomas ,   ESADA Study Group
Published: July 2019

SummaryIn obstructive sleep apnea, patients’ sleep is fragmented leading to excessive daytime sleepiness and co‐morbidities like arterial hypertension. However, traditional metrics are not always directly correlated with daytime sleepiness, and the association between traditional sleep quality metrics like sleep duration and arterial hypertension is still ambiguous. In a development cohort, we analysed hypnograms from mild (n = 209), moderate (n = 222) and severe (n = 272) obstructive sleep apnea patients as well as healthy controls (n = 105) from the European Sleep Apnea Database. We assessed sleep by the analysis of two‐step transitions depending on obstructive sleep apnea severity and anthropometric factors. Two‐step transition patterns were examined for an association to arterial hypertension or daytime sleepiness. We also tested cumulative distributions of wake as well as sleep‐states for power‐laws (exponent α) and exponential distributions (decay time τ) in dependency on obstructive sleep apnea severity and potential confounders. Independent of obstructive sleep apnea severity and potential confounders, wake‐state durations followed a power‐law distribution, while sleep‐state durations were characterized by an exponential distribution. Sleep‐stage transitions are influenced by obstructive sleep apnea severity, age and gender. N2 → N3 → wake transitions were associated with high diastolic blood pressure. We observed higher frequencies of alternating (symmetric) patterns (e.g. N2 → N1 → N2, N2 → wake → N2) in sleepy patients both in the development cohort and in a validation cohort (n = 425). In conclusion, effects of obstructive sleep apnea severity and potential confounders on sleep architecture are small, but transition patterns still link sleep fragmentation directly to obstructive sleep apnea‐related clinical outcomes like arterial hypertension and daytime sleepiness.
Analysis of the technical efficiency of Nile perch (Lates niloticus) fishers in the Tanzanian portion of Lake Victoria: A stochastic frontier analysis
Authors: Mkuna Eliaza , Baiyegunhi Lloyd J. S. 
Published: July 2019

AbstractThe Nile perch fishery sector in Tanzania is important for enhancing the livelihoods and food security for the majority of people living near the Tanzanian portion of Lake Victoria. Despite continued government efforts and other institutions, including the Food and Agriculture Organization (FAO), Lake Victoria Fisheries Organization (LVFO), European Union and World Bank regarding the management of Lake Victoria, the Nile perch fishers have remained relative inefficient in regard to improving their fish catches. The Nile perch small‐scale fisheries sector in particular faces a challenge regarding how to improve production performance while, at the same time, ensuring a sustainable level of fisheries resources. This reality necessitates the measurement and analysis of artisan fishers’ technical efficiency. Accordingly, the present study analyses Nile perch fishers technical efficiency, using a stochastic production frontier (SPF) model based on the sample of 268 Nile perch fishers in the Tanzanian portion of Lake Victoria. The translog stochastic frontier model results indicate the technical efficiency of Nile perch fishers range between 61% and 80%, with an overall average technical efficiency of 75%. This finding implies that, based on existing fishery resources, the current quantity of Nile perch catch can be improved efficiently by 25%, a reality highlighting mismanagement of the lake's fishery resources. The quantity of bait and petrol and the number of hooks used per trip are the most important fishing inputs, indicating a positive Nile perch fishing output–input elasticity. To address the Nile perch fisher inefficiency, it is important to provide subsidized inputs such as outboard engines and mesh gillnets. Provision of access to affordable credits will enable fishers to purchase less destructive fishing inputs and improve the current structure of fishery organizations.