bluuebunny/crossref_metadata_2025 huggingface dataset:
Stent Design Affects Femoropopliteal Artery Deformation
Authors: MacTaggart Jason , Poulson William , Seas Andreas , Deegan Paul , Lomneth Carol , Desyatova Anastasia , Maleckis Kaspars , Kamenskiy Alexey
Published: March 2018

Background:

Poor durability of femoropopliteal artery (FPA) stenting is multifactorial, and severe FPA deformations occurring with limb flexion are likely involved. Different stent designs result in dissimilar stent–artery interactions, but the degree of these effects in the FPA is insufficiently understood.

Objectives:

To determine how different stent designs affect limb flexion-induced FPA deformations.

Methods:

Retrievable markers were deployed into n = 28 FPAs of lightly embalmed human cadavers. Bodies were perfused and CT images were acquired with limbs in the standing, walking, sitting, and gardening postures. Image analysis allowed measurement of baseline FPA foreshortening, bending, and twisting associated with each posture. Markers were retrieved and 7 different stents were deployed across the adductor hiatus in the same limbs. Markers were then redeployed in the stented FPAs, and limbs were reimaged. Baseline and stented FPA deformations were compared to determine the influence of each stent design.

Results:

Proximal to the stent, Innova, Supera, and SmartFlex exacerbated foreshortening, SmartFlex exacerbated twisting, and SmartControl restricted bending of the FPA. Within the stent, all devices except Viabahn restricted foreshortening; Supera, SmartControl, and AbsolutePro restricted twisting; SmartFlex and Innova exacerbated twisting; and Supera and Viabahn restricted bending. Distal to the stents, all devices except AbsolutePro and Innova exacerbated foreshortening, and Viabahn, Supera, Zilver, and SmartControl exacerbated twisting. All stents except Supera were pinched in flexed limb postures.

Conclusions:

Peripheral self-expanding stents significantly affect limb flexion-induced FPA deformations, but in different ways. Although certain designs seem to accommodate some deformation modes, no device was able to match all FPA deformations.
Adrenal Metastasectomy in the Presence and Absence of Extraadrenal Metastatic Disease
Authors: Russo Ashley E. , Untch Brian R. , Kris Mark G. , Chou Joanne F. , Capanu Marinela , Coit Daniel G. , Chaft Jamie E. , D’Angelica Michael I. , Brennan Murray F. , Strong Vivian E.
Published: March 2018

Objective:

To determine if there are differences in overall survival (OS) or event-free survival (EFS) in patients with and without concomitant extra-adrenal metastases undergoing adrenal metastasectomy.

Background:

There is growing interest in the use of local therapies in patients with oligometastatic disease. Previously published series have indicated that long-term survival is possible with resection. Adrenalectomy has been used to treat adrenal metastases in select patients.

Methods:

Patients who underwent adrenal metastasectomy from 1994 to 2015 were identified from a prospectively maintained institutional database of adrenalectomy patients, excluding adrenalectomies due to tumor extension or for palliation. Sites of disease, treatment history, and survival data were extracted from chart review.

Results:

One hundred seventy-four patients were included. Tumor histology included 68 nonsmall cell lung cancer, 34 renal cancer, 18 colorectal cancer, 11 melanoma cancer, 10 hepatocellular cancer, 8 sarcoma cancer, and 25 other cancers. The median follow-up among survivors was 5.2 (1–21) years. OS at 3 and 5 years was 50% and 40%, respectively. Patients with (n = 83) and without (n = 91) extra-adrenal metastases did not differ with respect to age, adrenal tumor size, or margin status. Median OS (3.3 years for patients with concomitant extra-adrenal metastases and 3.0 years for patients with isolated adrenal metastases; P = 0.816) and EFS (9.39 vs 9.59 months; P = 0.87) were similar. Factors negatively associated with OS included adrenal tumor size (P < 0.01), renal primary versus other (P < 0.01), and adrenal margin status (P < 0.01).

Conclusions:

In selected patients undergoing adrenal metastasectomy, there were no significant differences in OS or EFS between patients with and without concomitant extra-adrenal metastases.
Positional information encoded in the dynamic differences between neighbouring oscillators during vertebrate segmentation
Authors: Boareto Marcelo , Tomka Tomas , Iber Dagmar
Published: March 2018

How cells track their position during the segmentation of the vertebrate body remains elusive. For decades, this process has been interpreted according to the clock-and-wavefront model, where molecular oscillators set the frequency of somite formation while the positional information is encoded in signaling gradients. Recent experiments usingex vivoexplants challenge this interpretation, suggesting that positional information is encoded in the properties of the oscillators. Here, we propose that positional information is encoded in the differential levels of neighboring oscillators. The differences gradually increase because both the oscillator amplitude and the period increase with time. When this difference exceeds a certain threshold, the segmentation program starts. Using this framework, we quantitatively fit experimental data fromin vivoandex vivomouse segmentation, and propose mechanisms of somite scaling. Our results suggest a novel mechanism of spatial pattern formation based on the local interactions between dynamic molecular oscillators.
Genome-wide survey and expression analysis of the SLAC/SLAH gene family in pear (Pyrus bretschneideri) and other members of the Rosaceae
Authors: Chen Guodong , Li Xiaolong , qiao Xin , Li Jiaming , Wang Li , Kou Xiaobing , Wu Xiao , Wang Guoming , Yin Hao , Wang Peng , Zhang Shaoling , Wu Juyou
Published: March 2018

S-type anion channels (SLAC/SLAHs), which play important roles in plant anion (such as nitrate and chloride) transport, growth and development, abiotic stress responses and hormone signaling. However, there is far less information about this family in Rosaceae species. We performed a genome-wide analysis and identified SLAC/SLAH gene family members in pear (Pyrus bretschneideri) and four other species of Rosaceae (Malus domestica, Prunus persica, Fragaria vesca and Prunus mume). A total of 21 SLAC/SLAH genes were identified from the five Rosaceae species. Based on the structural characteristics and a phylogenetic analysis of these genes, the SLAC/SLAH gene family could be classified into three main groups (I, II and III). The evolutionary analysis showed that the SLAC/SLAH gene family was comparatively conserved during the evolution of Rosaceae species. Transcriptome data demonstrated that PbrSLAC/SLAH genes were detected in all parts of the pear. However, PbrSLAC1 showed a higher expression level in leaf, while PbrSLAH2/3 was mainly expressed in roots. In addition, PbrSLAC/SLAH genes were only located on the plasma membrane in transient expression experiments in Arabidopsis protoplasts cells. These results provide valuable information that increases our understanding of the evolution, expression and functions of the SLAC/SLAH gene family in higher plants.
Intraspecific genetic and phenotypic diversity: parallel processes and correlated patterns?
Authors: Lisa Fourtune , Jérôme G. Prunier , Églantine Mathieu-Bégné , Nicolas Canto , Charlotte Veyssière , Géraldine Loot , Simon Blanchet
Published: March 2018

Intraspecific diversity plays a key role for evolutionary and ecological dynamics. It is the raw material on which acts selection, it improves species and communities resilience to disturbance and it affects the way species modulate their biotic and abiotic environment. Understanding patterns and underlying determinants of genetic and phenotypic intraspecific diversity is therefore of critical importance for ecological, evolutionary and conservation sciences. Here, focusing on two freshwater fish species (Gobio occitaniae and Phoxinus phoxinus) sampled across a large river basin (the Garonne-Dordogne river basin, France), we used causal analyses to test for genetic-phenotypic intraspecific diversity correlations (GPIDCs) and unravel the processes underlying intraspecific diversity patterns. Genetic diversity was assessed using microsatellite markers and phenotypic diversity was assessed through geometric morphometrics. We found disparities in the distribution of genetic and phenotypic diversity in the two species, suggesting higher level of local adaptation in G. occitaniae, and our results revealed common and contrasted processes shaping diversity at the α- and β-level. At the α-level, we found no GPIDC in both species despite common relations between isolation and genetic and phenotypic α-diversity in G. occitaniae. At the β-level, we found no GPIDC in P. phoxinus but we found a positive GPIDC in G. occitaniae. This correlation appeared to be caused by a direct impact of one facet of intraspecific diversity on the other, and we speculated that it could originate from positive assortative mating. Studying neutral genetic diversity and phenotypic diversity within an integrative framework appears as a valuable way of deciphering the complex and diverse impacts of neutral and adaptive processes on intraspecific diversity patterns.
Inhibition of mitochondrial ferredoxin 1 (FDX1) prevents adaptation to proteotoxic stress
Authors: Tsvetkov Peter , Detappe Alexandre , Cai Kai , Keys Heather R. , Brune Zarina , Ying Weiwen , Thiru Prathapan , Reidy Mairead , Kugener Guillaume , Tsherniak Aviad , Santagata Sandro , Whitesell Luke , Markley John L. , Ghobrial Irene M. , Lindquist Susan
Published: March 2018

The mechanisms used by cancer cells to resist the severe disruption in protein homeostasis caused by proteasome inhibitors remain obscure. Here, we show this resistance correlates with a metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS). Employing small molecule screens, we identified a striking overlap between compounds that preferentially impede the growth of proteasome inhibitor-resistant cancer cells and those that block the growth of high OXPHOS cells. Elesclomol potently exhibits both characteristics. Using genome-wide CRISPR/Cas9-based screening, in vitro validation and NMR spectroscopy we identify mitochondrial protein ferredoxin 1 (FDX1), a critical component of mitochondrial iron-sulfur (Fe-S) cluster biosynthesis, as the primary target of elesclomol. In a mouse model of multiple myeloma, inhibition of FDX1 with elesclomol significantly attenuated the emergence of proteasome inhibitor-resistance and markedly prolonged survival. Our work reveals that the mitochondrial Fe-S cluster pathway is a targetable vulnerability in cancers that are resistant to increased proteotoxic burden.
Evolutionary rate coevolution between mitochondria and mitochondria-associated nuclear-encoded proteins in insects
Authors: Yan Zhichao , Ye Gongyin , Werren John H.
Published: March 2018

The mitochondrion is a pivotal organelle for energy production, and includes components encoded by both the mitochondrial and nuclear genomes. How these two genomes coevolve is a long-standing question in evolutionary biology. Here we initially investigate the evolutionary rates of mitochondrial components (oxidative phosphorylation (OXPHOS) proteins and ribosomal RNAs) and nuclear-encoded proteins associated with mitochondria, across the major orders of holometabolous insects. There are significant evolutionary rate correlations (ERCs) between mitochondria and mitochondria-associated nuclear-encoded proteins, which is likely driven by different rates of mitochondrial sequence evolution and compensatory changes in the interacting nuclear-encoded proteins. The pattern holds after correction for phylogenetic relationships and considering protein conservation levels. Correlations are stronger for nuclear-encoded OXPHOS proteins in contact with mitochondrial-encoded OXPHOS proteins and nuclear-encoded mitochondrial ribosomal amino acids directly contacting the mitochondrial rRNA. Mitochondrial-associated proteins show apparent rate acceleration over evolutionary time, but we suspect this pattern to be due to artifacts (e.g. rate estimation or calibration bias). We find that ERC between mitochondrial and nuclear proteins is a strong predictor of nuclear proteins known to interact with mitochondria, and therefore ERCs can be used to predict new candidate nuclear proteins with mitochondrial function. Using this approach, we detect proteins with high ERCs but not with known mitochondrial function based on gene ontology (GO). Manual screening of the literature revealed potential mitochondrial function for some of these proteins in humans or yeast. Their holometabolous ERCs therefore indicate these proteins may have phylogenetically conserved mitochondrial function. Twenty three additional candidates warrant further study for mitochondrial function based on this approach, including ERC evidence that proteins in the minichromosome maintenance helicase (MCM) complex interact with mitochondria. We conclude that the ERC method shows promise for identifying new candidate proteins with mitochondrial function.
Molecular and electrophysiological features of spinocerebellar ataxia type seven in induced pluripotent stem cells
Authors: Burman RJ , Watson LM , Smith DC , Raimondo JV , Ballo R , Scholefield J , Cowley SA , Wood MJA , Kidson SH , Greenberg LJ
Published: March 2018

Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the ATXN7 gene. Patients with this disease suffer from a degeneration of their cerebellar Purkinje neurons and retinal photoreceptors that result in a progressive ataxia and loss of vision. As with many neurodegenerative diseases, studies of pathogenesis have been hindered by a lack of disease-relevant models. To this end, we have generated induced pluripotent stem cells (iPSCs) from a cohort of SCA7 patients in South Africa. First, we differentiated the SCA7 affected iPSCs into neurons which showed evidence of a transcriptional phenotype affecting components of STAGA (ATXN7 and KAT2A) and the heat shock protein pathway (DNAJA1 and HSP70). We then performed electrophysiology on the SCA7 iPSC-derived neurons and found that these cells show features of functional aberrations. Lastly, we were able to differentiate the SCA7 iPSCs into retinal photoreceptors that also showed similar transcriptional aberrations to the SCA7 neurons. Our findings demonstrate that iPSC-derived neurons and photoreceptors from SCA7 patients express molecular and electrophysiological differences that are indicative of impaired neuronal health. We hope that these findings will contribute towards the ongoing efforts to establish the cell-derived models of neurodegenerative diseases that are needed to develop patient-specific treatments.
Checkpoint signaling abrogation after cell cycle reentry reveals that differentiated neurons are mitotic cells
Authors: Walton Chaska C , Zhang Wei , Patiño-Parrado Iris , Barrio-Alonso Estíbaliz , Garrido Juan-José , Frade José M
Published: March 2018

Mitotic activity associated to neuron cell-death instead of cell-division is reported in neurodegenerative diseases. However, why mitotic activity can take place in supposedly postmitotic neurons and how it is associated to cell-death remains largely unexplained. To address these questions, we have studied the response of primary neurons to oncogenic deregulation using a fusion protein based on truncated Cyclin E and Cdk2. Oncogenic Cyclin E/Cdk2 elicits mitotic checkpoint signaling, resulting in cell-cycle arrest and cell-death. However, as in mitotic cells, checkpoint suppression enables oncogenic cell-cycle progression and neuronal division. Further, neurons actively adapt to the cell-cycle by losing and reforming the axon initial segment, which integrates synaptic inputs to sustain action potentials. We conclude that neurons are mitotic cells in a reversible quiescent-like state, which is falsely portrayed as irreversible by mitotic checkpoints. In extension, neuronal death in lieu of cell-division reflects oncosuppressive checkpoint signaling.
Modeling semantic encoding in a common neural representational space
Authors: Van Uden Cara E. , Nastase Samuel A. , Connolly Andrew C. , Feilong Ma , Hansen Isabella , Gobbini M. Ida , Haxby James V.
Published: March 2018

Encoding models for mapping voxelwise semantic tuning are typically estimated separately for each individual, limiting their generalizability. In the current report, we develop a method for estimating semantic encoding models that generalize across individuals. Functional MRI was used to measure brain responses while participants freely viewed a naturalistic audiovisual movie. Word embeddings capturing agent-, action-, object-, and scene-related semantic content were assigned to each imaging volume based on an annotation of the film. We constructed both conventional within-subject semantic encoding models and between-subject models where the model was trained on a subset of participants and validated on a left-out participant. Between-subject models were trained using cortical surface-based anatomical normalization or surface-based whole-cortex hyperalignment. We used hyperalignment to project group data into an individual's unique anatomical space via a common representational space, thus leveraging a larger volume of data for out-of-sample prediction while preserving the individual's fine-grained functional–anatomical idiosyncrasies. Our findings demonstrate that anatomical normalization degrades the spatial specificity of between-subject encoding models relative to within-subject models. Hyperalignment, on the other hand, recovers the spatial specificity of semantic tuning lost during anatomical normalization, and yields model performance exceeding that of within-subject models.
Benfotiamine reduces pathology and improves muscle function in mdx mice
Authors: Woodman Keryn G. , Coles Chantal A. , Toulson Su L , Gibbs Elizabeth M. , Knight Matthew , McDonagh Matthew , Crosbie-Watson Rachelle H. , Lamandé Shireen R. , White Jason D.
Published: March 2018

Duchenne Muscular Dystrophy (DMD) is a progressive and fatal neuromuscular disease which arises from mutations in the dystrophin gene (DMD) that result in the absence or severe reduction of the cytoskeletal protein dystrophin. In addition to the primary dystrophin defect, secondary processes such as inflammation, calcium influx, dysregulated autophagy and fibrosis exacerbate dystrophic pathology and thus increase disease progression. While therapies to restore dystrophin deficiency are being developed, strategies which target these secondary processes could be of benefit to patients. Benfotiamine is a lipid soluble precursor to thiamine that can reduce secondary processes such as inflammation and oxidative stress in diabetic patients. As such we tested it in the mdx mouse model of DMD and found that benfotiamine reduced multiple markers of dystrophic pathology and improved grip strength. In addition, members of the utrophin and dystrophin glycoprotein complexes were significantly increased at the sarcolemma which could improve cell adhesion. We also demonstrated that benfotiamine treatment lowered the expression of macrophage markers and pro-inflammatory cytokines suggesting that benfotiamine is reducing dystrophic pathology by acting on inflammatory processes.
Past selection impacts the strength of an aquatic trophic cascade
Authors: Ousterhout Brittany H. , Graham Savannah R. , Hasik Adam Z. , Serrano Mabel , Siepielski Adam M.
Published: March 2018

In complex food webs, interactions among species in different trophic levels can generate cascading indirect effects that couple top predators with primary producers, thereby affecting ecosystem functioning. Natural selection imposed by top predators on intermediate predators may play a role in shaping the strength of these trophic cascades, but this conjecture remains largely untested.

To determine the effects of natural selection on the strength of trophic cascades, we conducted a two‐part experiment in a four‐level aquatic trophic system involving a top predator (fish), an intermediate predator (damselflies), herbivores (zooplankton) and primary producers (algae). We first quantified how predation by fish generated selection on damselfly activity levels after controlling for phenotypic plasticity. We then measured the indirect effects of this selection on primary production (phytoplankton biomass). In both experiments, we varied the density of predators, allowing us to elucidate both trait‐mediated and density‐mediated indirect effects.

We found that as fish density increased, damselfly survivorship declined, which generated natural selection favouring less active damselflies. These results are robust after taking into account latent effects of plasticity in response to fish predator cues. The surviving damselflies likely foraged less, freeing herbivores from predation, which in turn reduced primary production. This selection‐driven trait‐mediated indirect effect was only apparent at low damselfly densities, because the consumptive effect of damselflies at high densities overwhelmed the effects of past selection.

These results demonstrate how the past action of natural selection imposed by predators affects the phenotypes of prey that consume herbivores, which ultimately influences primary productivity—a selective trophic cascade. Natural selection can therefore act as a mechanism coupling ecological dynamics across trophic levels, which ultimately influences ecosystem functioning.

A plain language summary is available for this article.
Metabolic scaling across succession: Do individual rates predict community‐level energy use?
Authors: Ghedini Giulia , White Craig R. , Marshall Dustin J.
Published: March 2018

A major goal of metabolic ecology is to make predictions across scales such that individual metabolic rates might be used to predict the metabolic rates of populations and communities, but the success of these predictions is unclear given the rarity of tests.

Given that older communities tend to have species with slower life histories and larger body sizes, we hypothesized that the metabolism of whole communities should scale allometrically with their mass across successional stages.

We created experimental chronosequences of sessile marine invertebrate communities in the field. We then (1) determined the metabolic scaling of these whole communities across successional stages of different mass and (2) tested whether the sum of individual metabolic rates for the dominant species could predict overall community metabolism.

Contrary to what we expected based on metabolic theory and succession theory, community metabolism scaled isometrically with mass across succession, despite the mean body size of dominant individuals within the communities increasing over time. We resolved this paradox by estimating community metabolism based on individual metabolic rates for the dominant species in the community. We show that non‐random changes in the membership of the species maintain mass‐specific metabolic rates of the whole community invariant across succession despite changes in size structure.

These results suggest that simple assumptions about how community‐level processes scale up from species are unlikely to be correct, because community turnover is non‐random with respect to metabolic rate. Nevertheless, with the appropriate parametrization, the sum of individual species rates can predict the function of the community as a whole.

A plain language summary is available for this article.
Drivers of power line use by white storks: A case study of birds nesting on anthropogenic structures
Authors: Moreira Francisco , Martins Ricardo C. , Catry Inês , D'Amico Marcello
Published: March 2018

Anthropogenic structures are mainly known to have negative impacts on wildlife populations but they can be beneficial. Power lines are a main driver of bird mortality through collision or electrocution, but electricity pylons are also commonly used for nest building by some species. Birds and nests cause power outages that need to be tackled by electricity companies. However, the use of pylons by threatened species provides an opportunity for conservation purposes.

In this study, we describe an empirical modelling approach to predict the circumstances under which nesting birds use electricity pylons. We focused on white storks Ciconia ciconia, a species that has been increasingly using electricity pylons for nesting across Europe.

In a country‐level census in Portugal, we found a total of 1,348 white stork nests in 668 of the 8,680 very high‐tension power line pylons occurring in the distribution range of this colonial species, with spatial clustering in pylon occupation up to a distance of 30 km. The number of nests in each used pylon ranged from 1 to 21 (M ± SD = 2.2 ± 2.06).

The main drivers of pylon use by nesting storks were distance to major feeding areas (rice fields, landfills and large wetlands), with more intensive use closer to these features, followed by land cover type surrounding each pylon. Pylon type and age, and stork population density in the region, had comparatively less importance.

Synthesis and applications. We developed an approach to predict the use of anthropogenic structures by nesting birds that can be used both for species conservation and minimising damage to infrastructures. For power lines, applications include: (1) planning power line routes to take account of the probability of pylon use; (2) applying nesting deterrent devices (to reduce bird mortality and power outage risk) and providing nesting platforms (to promote bird use) on suitable pylons and (3) selecting adequate pylon types to promote or inhibit nesting.
Spatial, temporal and experimental: Three study design cornerstones for establishing defensible numeric criteria in freshwater ecosystems
Authors: Taylor Jason M. , Back Jeffrey A. , Brooks Bryan W. , King Ryan S.
Published: March 2018

Nutrient over‐enrichment increasingly threatens global water resources. Stressor‐response studies specifically designed to identify levels of nutrients strongly associated with undesirable ecological conditions are needed to inform numeric nutrient criteria that protect inland waters.

Diatoms are important components of aquatic life, which support higher trophic levels and are sensitive to nutrient enrichment. We tested a framework that relies on stressor‐response modelling of phosphorus (P) enrichment and stream diatom assemblages across many field locations, multiple years and seasons within years, and under controlled experimental conditions to inform nutrient criteria development.

Diatom species composition was nonlinearly correlated with total phosphorus (TP) throughout the 2‐year field study. This occurred despite temporal shifts in species composition between two hydrologically distinct years and over eight seasons.

Species assemblages on rocks transplanted from a low P stream to mesocosms representing a P enrichment gradient (8, 20 and 100 μg/L) shifted into two groups over time. Species composition on rocks in low (20 μg/L) and high (100 μg/L) P mesocosms was consistent with assemblages at P‐enriched field sites, whereas rocks in control (8 μg/L) mesocosms had significantly different species composition, consistent with low P field sites. Species composition on rocks transplanted from high P streams did not shift as dramatically and were not significantly different after exposure to different P treatments in mesocosms.

Threshold Indicator Taxa Analysis identified synchronous declines in several diatom species that culminated in assemblage thresholds associated with TP concentrations >20 and 25 μg/L for 2006 and 2007 respectively.

Synthesis and applications. Diatom assemblages show consistent responses to nutrient enrichment despite temporal shifts associated with confounding factors common in stream ecosystems. Regulators should include diatom assemblage responses when developing numeric nutrient criteria. We present a framework that includes spatial, temporal and experimental components, and has broad applicability for use in different ecological settings to evaluate ecological endpoints and set limits for a variety of contaminants threatening freshwater ecosystems throughout the world.
The cover uncovered: Bark control over wood decomposition
Authors: Dossa Gbadamassi G. O. , Schaefer Douglas , Zhang Jiao‐Lin , Tao Jian‐Ping , Cao Kun‐Fang , Corlett Richard T. , Cunningham Anthony B. , Xu Jian‐Chu , Cornelissen Johannes H. C. , Harrison Rhett D.
Published: March 2018

Woody debris (WD) represents a globally significant carbon stock and its decomposition returns nutrients to the soil while providing habitat to microbes, plants and animals. Understanding what drives WD decomposition is therefore important.

WD decomposition rates differ greatly among species. However, the role of bark in the process remains poorly known.

We ask how, and how much, interspecific variation in bark functional traits related to growth and protection have afterlife effects on the decomposition of wood, partly mediated by animals. We examine the roles of bark cover and bark traits throughout the wood decomposition process.

Synthesis. We find that: (1) bark effects on WD decomposition are species‐ and wood size‐specific, (2) bark can enhance coarser WD decomposition but slows twig decomposition in some species, and (3) bark acts as an environmental filter to faunal assemblages in the early stage of wood decomposition.

We highlight the need to account for bark effects on WD decomposition and offer an important complementary contribution to including woody species identity effects in biogeochemical and climate‐change models via species bark traits.
Multi‐dimensional patterns of variation in root traits among coexisting herbaceous species in temperate steppes
Authors: Zhou Meng , Bai Wenming , Zhang Yushi , Zhang Wen‐Hao
Published: March 2018

Characterizing patterns of variation in plant traits across species and environmental gradients is critical for understanding performance of species in ecosystems. One‐dimensional pattern of variation has been demonstrated in leaf traits, which is known as the leaf economic spectrum. However, it is unclear whether such a spectrum exists for root traits.

For roots of 15 species from temperate grasslands, we determined respiration rate, relative growth rate, life span and 10 morphological, chemical and anatomical root traits. We further evaluated pairwise and multiple‐trait relationships by Pearson's correlation and principle component analysis including phylogenetic contrasts.

We found that root functions were related to three clusters of variation. Root respiration rate and relative growth rate were positively correlated with average root diameter (AD), but they were negatively correlated with specific root length (SRL). In contrast, root life span was not correlated with AD, but it was positively correlated with SRL. These results are inconsistent with the presumption of the root economic spectrum.

The principle components analysis revealed a multi‐dimensional pattern of variation in root traits among the 15 coexisting herbaceous species. Moreover, species within the same phylogenetic clades tended to have similar root trait syndromes. Most of the root traits exhibited a significant phylogenetic signal.

Synthesis. Our results do not support a one‐dimensional root economic spectrum in the coexisting herbaceous species of temperate grasslands. In contrast, the pattern of variation in root traits was multi‐dimensional. We further demonstrated that species in different phylogenetic clades possess diverse root trait syndromes for efficient resource acquisition. Our findings provide a next step in understanding root functions and plant strategies in temperate grasslands.
Temporal variation in plant–pollinator networks from seasonal tropical environments: Higher specialization when resources are scarce
Authors: Souza Camila S. , Maruyama Pietro K. , Aoki Camila , Sigrist Maria R. , Raizer Josué , Gross Caroline L. , de Araujo Andréa C.
Published: March 2018

The temporal dynamics of plant phenology and pollinator abundance across seasons should influence the structure of plant–pollinator interaction networks. Nevertheless, such dynamics are seldom considered, especially for diverse tropical networks.

Here, we evaluated the temporal variation of four plant–pollinator networks in two seasonal ecosystems in Central Brazil (Cerrado and Pantanal). Data were gathered on a monthly basis over 1 year for each network. We characterized seasonal and temporal shifts in plant–pollinator interactions, using temporally discrete networks. We predicted that the greater floral availability in the rainy season would allow for finer partitioning of the floral niche by the pollinators, i.e. higher specialization patterns as previously described across large spatial gradients. Finally, we also evaluated how sampling restricted to peak flowering period may affect the characterization of the networks.

Contrary to our expectations, we found that dry season networks, although characterized by lower floral resource richness and abundance, showed higher levels of network‐wide interaction partitioning (complementary specialization and modularity). For nestedness, though, this between‐seasons difference was not consistent. Reduced resource availability in the dry season may promote higher interspecific competition among pollinators leading to reduced niche overlap, thus explaining the increase in specialization.

There were no consistent differences between seasons in species‐level indices, indicating that higher network level specialization is an emergent property only seen when considering the entire network. However, bees presented higher values of specialization and species strength in relation to other groups such as flies and wasps, suggesting that some plant species frequently associated with bees are used only by this group.

Our study also indicates that targeted data collection during peak flowering generates higher estimates of network specialization, possibly because species activity spans longer periods than the targeted time frame. Hence, depending on the period of data collection, different structural values for the networks of interactions may be found.

Synthesis. Plant–pollinator networks from tropical environments have structural properties that vary according to seasons, which should be taken into account in the description of the complex systems of interactions between plants and their pollinators in these areas.
Nitrogen fixer abundance has no effect on biomass recovery during tropical secondary forest succession
Authors: Lai Hao Ran , Hall Jefferson S. , Batterman Sarah A. , Turner Benjamin L. , van Breugel Michiel
Published: March 2018

Nitrogen‐fixing trees (N2 fixers) provide new nitrogen critical for rapid biomass accumulation of tropical forests during early secondary succession, but it remains unclear how the abundance of N2 fixers in the forest community affects the growth of non‐fixers or the primary productivity of the whole forest.

On the one hand, N2 fixers may enhance forest productivity by providing a facilitative effect through the provision of plant‐available nitrogen to non‐fixing trees. On the other hand, N2 fixers may suppress the growth of non‐fixers by growing faster and competing more vigorously for light and other resources. A third alternative is that the growth of N2 fixers themselves accumulate biomass rapidly, while having a neutral effect on non‐fixers, leading to an overall increase in forest biomass.

We examine these alternative hypotheses using 5‐year tree census data from 88 plots in 44 seasonal tropical moist secondary forests (3–32 years old) across a human‐modified landscape in central Panama. We examined whether N2 fixers accumulated biomass more rapidly than non‐fixers, and how relative biomass of N2 fixers as a functional group and as individual species influenced the growth of non‐fixer and whole stand primary productivity.

Surprisingly, we found no evidence for either a net competitive or a facilitative effect of N2 fixers as a functional group or individual species on the biomass recovery in these young forests. N2 fixers did not grow faster than non‐fixers. Individual mortality rates were lower among N2 fixers, but biomass losses due to mortality were similar between the two groups. Overall, we found no relationship between the relative abundance of N2 fixers and stand primary productivity during succession.

Synthesis. Nitrogen‐fixing trees may be critical for reducing nitrogen limitation and accelerating biomass growth during tropical secondary forest succession, thereby impacting the global carbon cycle. However, our findings indicate that, in early successional seasonal tropical moist forests, nitrogen fixers provide neither a net competitive nor a facilitative effect on non‐fixing trees or the whole forest stand, likely because tropical nitrogen fixers utilize facultative fixation and hence abundance poorly approximates the ecosystem function of fixation. Our results indicate that models should not simply scale symbiotic fixation and its effects from nitrogen‐fixing tree abundance.
Effects of natural forest dynamics on vascular plant, bryophyte, and lichen diversity in primevalFagus sylvaticaforests and comparison with production forests
Authors: Kaufmann Stefan , Hauck Markus , Leuschner Christoph
Published: March 2018

Stand structure, mean tree age, deadwood amount and microclimate all change markedly in the course of natural forest dynamics. The last remaining primeval forests of the temperate forest biome are valuable study objects to investigate the effects of forest dynamics and management on forest structure and function as well as phytodiversity, which is not sufficiently understood.

Three pairs ofFagus sylvaticaprimeval and production forests in eastern Slovakia were selected for studying the effects of natural forest development stages on vascular plant, bryophyte, and lichen species richness and composition. We further compared the diversity patterns in the initial, optimal and terminal stages of forest development with those of nearby production forests.

The plot‐level species richness of epiphytic bryophytes and lichens increased from the initial to the terminal stage, but only lichens exhibited a significantly higher cumulative species richness (γ diversity) in the later (optimal and terminal) stages. No increase in species richness from the initial to the terminal stage was found for deadwood‐inhabiting epiphytes and the ground‐layer vascular plants. Canonical correspondence analyses identified characteristic bryophyte and lichen species for the different development stages, while the bulk of vascular ground layer species occurred across all stages with no stage preference.

Stem diameter was an even more important driver of epiphyte diversity and species composition than the development stage. All stages of the primeval forests (including the initial) were more species‐rich in epiphytes and, when investigating larger plot numbers, also in vascular plants than the production forests.

Synthesis. In primeval forests of European beech, plant species richness did not differ significantly between the consecutive forest development stages, while species composition did. This is attributable to the small‐scale mosaic structure of the forest, rapid gap closure by beech, and the continuity of deadwood across the stages, which reduces spatio‐temporal differences in microhabitat availability in the forest. Bryophytes and lichens are species‐richer, and vascular plants at least similarly rich, in the primeval as compared to the production forests, if the study area is sufficiently large.
The contribution of occupation to children’s experience of resilience: A qualitative descriptive study
Authors: Bowden Linda , Reed Kirk , Nicholson Ellen
Published: March 2018

Background

This qualitative descriptive study explored what occupations children aged 10–13 years participate in and how participation in occupation contributes to resilience from their perspective. Little is known about how occupations contribute to resilience, and less is known from children's perspectives. Exploring how participation in occupation contributes to resilience is important as children continue to face adverse situations; resilience may help protect their development against uncertainty.

Methods

Following ethics approval eight participants were recruited through schools in a large New Zealand city. Data were collected through semi‐structured interviews and one focus group, these were audio recorded and transcribed. The six‐phase process of thematic analysis, developed by Braun and Clarke (), was utilised to analyse the data.

Findings

Three main themes emerged from the data: what resilience is, occupations children do and how those occupations contribute to resilience and thirdly; building participation and resilience. The study revealed sophisticated descriptions of what resilience meant to the participants from their experience, which included the ideas of bouncing back and staying strong. The participants described what occupations they participate in and how these occupations connect to resilience. The participants also described their experience of how participation in their occupations helped build resilience by fostering support, letting go, experiencing distraction, and experiencing fun and happiness.

Conclusion

The findings suggest that health professionals, policy makers and educators have much to learn from children. Specifically, the need for children to participate in occupations as a way to build resilience. This indicates that a child‐focussed approach is needed to incorporate children's perspectives in practice and policy development. The findings suggest that practitioners working with children should incorporate participation in occupation in social, health and education intervention plans with children, as well as use occupation based coping strategies when teaching children skills to manage challenges in life.
Long non‐coding RNA NEAT1 mediates the toxic of Parkinson's disease induced by MPTP/MPP+ via regulation of gene expression
Authors: Liu Ying , Lu Zuneng
Published: March 2018

Parkinson's disease (PD) is a result of the loss of dopaminergic neurons in the substantia nigra and is expected to increase the economic burden on patients’ families and societies. NEAT1, a long non‐coding RNA, is known as a cancer‐related gene, however, the role of it in PD remains unclear. The aims of this study are to detect the NEAT1‐mediated effects in PD and explore the mechanism of NEAT1 in PD. One group (n = 6) of C57BL/6 model mice were intraperitoneal injected with 1‐Methyl‐4‐phenyl‐2, 3, 6‐tetrahydropyridine (MPTP), while another group (n = 6) was treated with saline and served as control. Human neuroblastoma cell line SH‐SY5Y was pretreated with 1‐Methyl‐4‐phenylpyridinium (MPP+). Cell viability and apoptosis, as well as gene expression with different treatments were examined. Up‐regulated NEAT1 was found in MPTP‐induced PD mice. Moreover, the NEAT1 expression was positively correlated with the concentration of MPP+. In SH‐SY5Y cells stimulated by MPP+, NEAT1 knockdown dramatically promoted cell viability and suppressed cell apoptosis. Additionally, down‐regulation of NEAT1 also decreased the ratio of Bax/Bcl‐2, the activity of caspase‐3, as well as the expression of α‐synuclein. Moreover, α‐synuclein overexpression could significantly reverse the increase in cell viability and the decrease in cell apoptosis induced by NEAT1 knockdown. The results suggested that the knockdown of NEAT1 will have a protective effect on MPTP‐induced PD mice. The mechanism may be related to the dysregulation of α‐synuclein.
Patient characteristics associated with peglyated interferon alfa‐2a induced neutropenia in chronic hepatitis C patients
Authors: Hindi Nagham N , Saleh Mohammad I
Published: March 2018

Neutropenia is a haematologic disorder commonly reported in patients with chronic hepatitis C virus (HCV) infection treated with pegylated interferon alfa‐2a (PEG‐IFN α‐2a). The objective of the present project is to identify patient characteristics associated with neutropenia in hepatitis C patients. Demographic, clinical, and genetic data from 715 patients with chronic HCV infection treated with PEG‐IFN α‐2a and ribavirin. The outcome variable was the development of grade 3 or 4 neutropenia, defined as the decrease in neutrophil counts below 1 109/L anytime during study. Predictors of neutropenia were identified using a 2‐stage approach. First, univariate analysis was performed to identify possible predictors of neutropenia. T test was used for continuous variables and Fisher's exact test was used for categorical variables. Second, multiple logistic regression with stepwise addition was then performed using predictors identified in the univariate analysis step to produce final model containing independent predictors at P < .05. Logistic regression identified female gender, absolute neutrophils counts, and cholesterol level as the main predictors of neutropenia. Female gender increases the odds of experiencing neutropenia by 86% compared to male gender. A 1 unit (mmol/L) increase in cholesterol level decreases the odds of developing neutropenia by 13%. A 55% reduction in the likelihood of developing neutropenia for a 1 unit (109/L) increase in the absolute neutrophils counts. Patients with high risk of developing neutropenia can be identified. Identification of this cohort allows early intervention to prevent neutropenia. Possible intervention is to administer drugs that raise neutrophil count such as filgrastim before neutropenia occurs.
Essential role of Rpd3‐dependent lysine modification in the growth, development and virulence of Beauveria bassiana
Authors: Cai Qing , Wang Zhi‐Kang , Shao Wei , Ying Sheng‐Hua , Feng Ming‐Guang
Published: March 2018

Rpd3 is a class I histone deacetylase that reverses lysine acetylation thus influencing cellular processes and functions. However, its role in fungal insect pathogens has not been explored yet. Here we show that Rpd3‐dependent lysine modification and gene expression orchestrate growth, conidiation and virulence in Beauveria bassiana. Deletion of Rpd3 resulted in severe growth defects on various carbon/nitrogen sources, 97% reduction in conidiation capacity and drastic attenuation in virulence. These phenotypes concurred with differential expression of 1479 proteins and hyperacetylation or hypoacetylation of 2227 lysine residues on 1134 proteins. Many of these proteins fell into carbon/nitrogen metabolism and cell rescue/defence/virulence, indicating vital roles of Rpd3‐dependent protein expression and lysine modification in the fungal growth and virulence. Intriguingly, lysine residues of four core histones (H2A, H2B, H3 and H4) and many histone acetyltransferases were also hyper‐ or hypoacetylated in Δrpd3, suggesting direct and indirect roles for Rpd3 in genome‐wide lysine modification. However, crucial development activators were transcriptionally repressed and not found in either proteome or acetylome. Single/double‐site‐directed H3K9/K14 mutations for hyper/hypoacetylation exerted significant impacts on conidiation and dimorphic transition crucial for fungal virulence. Altogether, Rpd3 mediates growth, asexual development and virulence through transcriptional/translational regulation and posttranslational lysine modification in B. bassiana.