bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kidney allograft failure in the steroid‐free immunosuppression era: A matched case‐control study
Authors: Alkadi Mohamad M. , Kim Jim , Aull Meredith J. , Schwartz Joseph E. , Lee John R. , Watkins Anthony , Lee Jun B. , Dadhania Darshana M. , Seshan Surya V. , Serur David , Kapur Sandip , Suthanthiran Manikkam , Hartono Choli , Muthukumar Thangamani 
Published: September 2017

AbstractWe studied the causes and predictors of death‐censored kidney allograft failure among 1670 kidney recipients transplanted at our center in the corticosteroid‐free maintenance immunosuppression era. As of January 1, 2012, we identified 137 recipients with allograft failure; 130 of them (cases) were matched 1‐1 for recipient age, calendar year of transplant, and donor type with 130 recipients with functioning grafts (controls). Median time to allograft failure was 29 months (interquartile range: 18‐51). Physician‐validated and biopsy‐confirmed categories of allograft failure were as follows: acute rejection (21%), glomerular disease (19%), transplant glomerulopathy (13%), interstitial fibrosis tubular atrophy (10%), and polyomavirus‐associated nephropathy (7%). Graft failures were attributed to medical conditions in 21% and remained unresolved in 9%. Donor race, donor age, human leukocyte antigen mismatches, serum creatinine, urinary protein, acute cellular rejection, acute antibody‐mediated rejection, BK viremia, and CMV viremia were associated with allograft failure. Independent predictors of allograft failure were acute cellular rejection (odds ratio: 18.31, 95% confidence interval: 5.28‐63.45) and urine protein ≥1 g/d within the first year post‐transplantation (5.85, 2.37‐14.45). Serum creatinine ≤1.5 mg/dL within the first year post‐transplantation reduced the odds (0.29, 0.13‐0.64) of allograft failure. Our study has identified modifiable risk factors to reduce the burden of allograft failure.
Using a novel model approach to assess the distribution and conservation status of the endangered Baird's tapir
Authors: Schank Cody J. , Cove Michael V. , Kelly Marcella J. , Mendoza Eduardo , O'Farrill Georgina , Reyna‐Hurtado Rafael , Meyer Ninon , Jordan Christopher A. , González‐Maya Jose F. , Lizcano Diego J. , Moreno Ricardo , Dobbins Michael T. , Montalvo Victor , Sáenz‐Bolaños Carolina , Jimenez Eduardo Carillo , Estrada Nereyda , Cruz Díaz Juan Carlos , Saenz Joel , Spínola Manuel , Carver Andrew , Fort Jessica , Nielsen Clayton K. , Botello Francisco , Pozo Montuy Gilberto , Rivero Marina , de la Torre Jesús Antonio , Brenes‐Mora Esteban , Godínez‐Gómez Oscar , Wood Margot A. , Gilbert Jessica , Miller Jennifer A. 
Published: September 2017

AbstractAimWe test a new species distribution modelling (SDM) framework, while comparing results to more common distribution modelling techniques. This framework allows for the combination of presence‐only (PO) and presence‐absence (PA) data and accounts for imperfect detection and spatial bias in presence data. The new framework tested here is based on a Poisson point process model, which allows for predictions of population size. We compared these estimates to those provided by experts on the species.Species and LocationPresence data on Baird's tapir (Tapirus bairdii) throughout its range from southern México to northern Colombia were used in this research, primarily from the years 2000 to 2016.MethodsFour SDM frameworks are compared as follows: (1) Maxent, (2) a presence‐only (PO) SDM based on a Poisson point process model (PPM), (3) a presence‐absence (PA) SDM also based on a PPM and (4) an Integrated framework which combines the previous two models. Model averaging was used to produce a single set of coefficient estimates and predictive maps for each model framework. A hotspot analysis (Gi*) was used to identify habitat cores from the predicted intensity of the Integrated model framework.ResultsImportant variables to model the distribution of Baird's tapir included land cover, human pressure and topography. Accounting for spatial bias in the presence data affected which variables were important in the model. Maxent and the Integrated model produced predictive maps with similar patterns and were considered to be more in agreement with expert knowledge compared to the PO and PA models.Main conclusionsTotal abundance as predicted by the model was higher than expert opinion on the species, but local density estimates from our model were similar to available independent assessments. We suggest that these results warrant further validation and testing through collection of independent test data, development of more precise predictor layers and improvements to the model framework.
The need for large‐scale distribution data to estimate regional changes in species richness under future climate change
Authors: Titeux Nicolas , Maes Dirk , Van Daele Toon , Onkelinx Thierry , Heikkinen Risto K. , Romo Helena , García‐Barros Enrique , Munguira Miguel L. , Thuiller Wilfried , van Swaay Chris A. M. , Schweiger Oliver , Settele Josef , Harpke Alexander , Wiemers Martin , Brotons Lluís , Luoto Miska 
Published: September 2017

AbstractAimSpecies distribution models built with geographically restricted data often fail to capture the full range of conditions experienced by species across their entire distribution area. Using such models to predict distribution shifts under future environmental change may, therefore, produce biased projections. However, restricted‐scale models have the potential to include a larger sample of taxa for which distribution data are available and to provide finer‐resolution projections that are better applied to conservation planning than the forecasts of broad‐scale models. We examine the circumstances under which the projected shifts in species richness patterns derived from restricted‐scale and broad‐scale models are most likely to be similar.LocationEurope.MethodsThe distribution of butterflies in Finland, Belgium/Netherlands and Spain was modelled based on restricted‐scale (local) and broad‐scale (continental) distribution and climate data. Both types of models were projected under future climate change scenarios to assess potential changes in species richness.ResultsIn Finland, species richness was projected to increase strongly based on restricted‐scale models and to decrease slightly with broad‐scale models. In Belgium/Netherlands, restricted‐scale models projected a larger decrease in richness than broad‐scale models. In Spain, both models projected a slight decrease in richness. We obtained similar projections based on restricted‐scale and broad‐scale models only in Spain because the climatic conditions available here covered the warm part of the distributions of butterflies better than in Finland and Belgium/Netherlands.Main conclusionsRestricted‐scale models that fail to capture the warm part of species distributions produce biased estimates of future changes in species richness when projected under climatic conditions with no modern analogue in the study area. We recommend the use of distribution data beyond the boundaries of the study area to capture the part of the species response curves reflecting the climatic conditions that will prevail within that area in the future.
Encoding seasonal information in a two‐oscillator model of the multi‐oscillator circadian clock
Authors: Myung Jihwan , Pauls Scott D. 
Published: September 2017

AbstractThe suprachiasmatic nucleus (SCN) is a collection of about 10 000 neurons, each of which functions as a circadian clock with slightly different periods and phases, that work in concert with form and maintain the master circadian clock for the organism. The diversity among neurons confers on the SCN the ability to robustly encode both the 24‐h light pattern as well as the seasonal time. Cluster synchronization brings the different neurons into line and reduces the large population to essentially two oscillators, coordinated by a macroscopic network motif of asymmetric repulsive‐attractive coupling. We recount the steps leading to this simplification and rigorously examine the two‐oscillator case by seeking an analytical solution. Through these steps, we identify physiologically relevant parameters that shape the behaviour of the SCN network and delineate its ability to store past details of seasonal variation in photoperiod.
Temporal alignment of anticipatory motor cortical beta lateralisation in hidden visual‐motor sequences
Authors: Heideman Simone G. , van Ede Freek , Nobre Anna C. 
Published: September 2017

AbstractPerformance improves when participants respond to events that are structured in repeating sequences, suggesting that learning can lead to proactive anticipatory preparation. Whereas most sequence‐learning studies have emphasised spatial structure, most sequences also contain a prominent temporal structure. We used MEG to investigate spatial and temporal anticipatory neural dynamics in a modified serial reaction time (SRT) task. Performance and brain activity were compared between blocks with learned spatial‐temporal sequences and blocks with new sequences. After confirming a strong behavioural benefit of spatial‐temporal predictability, we show lateralisation of beta oscillations in anticipation of the response associated with the upcoming target location and show that this also aligns to the expected timing of these forthcoming events. This effect was found both when comparing between repeated (learned) and new (unlearned) sequences, as well as when comparing targets that were expected after short vs. long intervals within the repeated (learned) sequence. Our findings suggest that learning of spatial‐temporal structure leads to proactive and dynamic modulation of motor cortical excitability in anticipation of both the location and timing of events that are relevant to guide action.
Processing of temporally patterned sounds in the auditory cortex of Seba's short‐tailed bat,Carollia perspicillata
Authors: Martin Lisa M. , García‐Rosales Francisco , Beetz M. Jerome , Hechavarría Julio C. 
Published: September 2017

AbstractThis article presents a characterization of cortical responses to artificial and natural temporally patterned sounds in the bat species Carollia perspicillata, a species that produces vocalizations at rates above 50 Hz. Multi‐unit activity was recorded in three different experiments. In the first experiment, amplitude‐modulated (AM) pure tones were used as stimuli to drive auditory cortex (AC) units. AC units of both ketamine‐anesthetized and awake bats could lock their spikes to every cycle of the stimulus modulation envelope, but only if the modulation frequency was below 22 Hz. In the second experiment, two identical communication syllables were presented at variable intervals. Suppressed responses to the lagging syllable were observed, unless the second syllable followed the first one with a delay of at least 80 ms (i.e., 12.5 Hz repetition rate). In the third experiment, natural distress vocalization sequences were used as stimuli to drive AC units. Distress sequences produced by C. perspicillata contain bouts of syllables repeated at intervals of ~60 ms (16 Hz). Within each bout, syllables are repeated at intervals as short as 14 ms (~71 Hz). Cortical units could follow the slow temporal modulation flow produced by the occurrence of multisyllabic bouts, but not the fast acoustic flow created by rapid syllable repetition within the bouts. Taken together, our results indicate that even in fast vocalizing animals, such as bats, cortical neurons can only track the temporal structure of acoustic streams modulated at frequencies lower than 22 Hz.
Effects of the availability of accurate proprioceptive information on older adults' postural sway and muscle co‐contraction
Authors: Craig Chesney E. , Calvert Glenn H. M. , Doumas Michail 
Published: September 2017

AbstractDuring conditions of increased postural instability, older adults exhibit greater lower limb muscle co‐contraction. This response has been interpreted as a compensatory postural strategy, which may be used to increase proprioceptive information from muscle spindles or to stiffen the lower limb as a general response to minimise postural sway. The current study aimed to test these two hypotheses by investigating use of muscle co‐contraction during sensory transitions that manipulated proprioceptive input. Surface EMG was recorded from the bilateral tibialis anterior and gastrocnemius medialis muscles, in young (aged 18–30) and older adults (aged 68–80) during blind‐folded postural assessment. This commenced on a fixed platform (baseline: 2 min), followed by 3 min on a sway‐referenced platform (adaptation) and a final 3 min on a fixed platform again (reintegration). Sensory reweighting was slower in older adults, as shown by a significantly larger and longer postural sway after‐effect once a stable platform was restored. Muscle co‐contraction showed similar after‐effects, whereby older adults showed a larger increase in co‐contraction once the stable platform had been restored, compared to young adults. This co‐contraction after‐effect did not return to baseline until after 1 min. Our evidence for high muscle co‐contraction during the reintroduction of veridical proprioceptive input suggests that increased co‐contraction in older adults is not dependent on contemporaneous proprioceptive input. Rather, it is more likely that co‐contraction is a general postural strategy used to minimise postural sway, which is increased during this sensory transition. Future research should examine whether muscle co‐contraction is typically a reactive or anticipatory response.
Altered Cav1.2 function in the Timothy syndrome mouse model produces ascending serotonergic abnormalities
Authors: Ehlinger Daniel G. , Commons Kathryn G. 
Published: September 2017

AbstractPolymorphism in the geneCACNA1C, encoding the pore‐forming subunit of Cav1.2 L‐type calcium channels, has one of the strongest genetic linkages to schizophrenia, bipolar disorder and major depressive disorder: psychopathologies in which serotonin signaling has been implicated. Additionally, a gain‐of‐function mutation inCACNA1Cis responsible for the neurodevelopmental disorder Timothy syndrome that presents with prominent behavioral features on the autism spectrum. Given an emerging role for serotonin in the etiology of autism spectrum disorders (ASD), we investigate the relationship between Cav1.2 and the ascending serotonin system in the Timothy syndrome type 2 (TS2‐neo) mouse, which displays behavioral features consistent with the core triad ofASD. We find thatTS2‐neo mice exhibit enhanced serotonin tissue content and axon innervation of the dorsal striatum, as well as decreased serotonin turnover in the amygdala. These regionally specific alterations are accompanied by an enhanced active coping response during acute stress (forced swim), serotonin neuron Fos activity in the caudal dorsal raphe, and serotonin type 1A receptor‐dependent feedback inhibition of the rostral dorsal raphe nuclei. Collectively, these results suggest that the global gain‐of‐function Cav1.2 mutation associated with Timothy syndrome has pleiotropic effects on the ascending serotonin system including neuroanatomical changes, regional differences in forebrain serotonin metabolism and feedback regulatory control mechanisms within the dorsal raphe. Altered activity of the ascending serotonin system continues to emerge as a common neural signature across severalASDmouse models, and the capacity for Cav1.2 L‐type calcium channels to impact both serotonin structure and function has important implications for several neuropsychiatric conditions.
Corticospinal responses following strength training: a systematic review and meta‐analysis
Authors: Kidgell Dawson J. , Bonanno Daniel R. , Frazer Ashlyn K. , Howatson Glyn , Pearce Alan J. 
Published: September 2017

AbstractStrength training results in changes in skeletal muscle; however, changes in the central nervous system also occur. Over the last 15 years, non‐invasive brain stimulation techniques, such as transcranial magnetic stimulation, have been used to study the neural adaptations to strength training. This review explored the hypothesis that the neural adaptations to strength training may be due to changes in corticospinal excitability and inhibition and, such changes, contribute to the gain in strength following strength training. A systematic review, according to PRISMA guidelines, identified studies by database searching, hand‐searching and citation tracking between January 1990 and the first week of February 2017. Methodological quality of included studies was determined using the Downs and Black quality index. Data were synthesised and interpreted from meta‐analysis. Nineteen studies investigating the corticospinal responses following strength training were included. Meta‐analysis found that strength training increased strength [standardised mean difference (SMD) 0.84, 95% CI 0.55 to 1.13], decreased short‐interval intracortical inhibition (SMD −1.00, 95% CI −1.84 to −0.17) and decreased the cortical silent period (SMD −0.66, 95% CI −1.00 to −0.32). Strength training had no effect on motor threshold (SMD −0.12, 95% CI −0.49 to 0.25), but a borderline effect for increased corticospinal excitability (SMD 0.27, 95% CI 0.00 to 0.54). In untrained healthy participants, the corticospinal response to strength training is characterised by reduced intracortical inhibition and cortical silent period duration, rather than changes in corticospinal excitability. These data demonstrate that strength training targets intracortical inhibitory networks within the primary motor cortex (M1) and corticospinal pathway, characterising an important neural adaptation to strength training.
Inflammation alters AMPA‐stimulated calcium responses in dorsal striatal D2 but not D1 spiny projection neurons
Authors: Winland Carissa D. , Welsh Nora , Sepulveda‐Rodriguez Alberto , Vicini Stefano , Maguire‐Zeiss Kathleen A. 
Published: September 2017

AbstractNeuroinflammation precedes neuronal loss in striatal neurodegenerative diseases and can be exacerbated by the release of proinflammatory molecules by microglia. These molecules can affect trafficking of AMPARs. The preferential trafficking of calcium‐permeable versus impermeable AMPARs can result in disruptions of [Ca2+]i and alter cellular functions. In striatal neurodegenerative diseases, changes in [Ca2+]i and L‐type voltage‐gated calcium channels (VGCCs) have been reported. Therefore, this study sought to determine whether a proinflammatory environment alters AMPA‐stimulated [Ca2+]i through calcium‐permeable AMPARs and/or L‐type VGCCs in dopamine‐2‐ and dopamine‐1‐expressing striatal spiny projection neurons (D2 and D1 SPNs) in the dorsal striatum. Mice expressing the calcium indicator protein, GCaMP in D2 or D1 SPNs, were utilized for calcium imaging. Microglial activation was assessed by morphology analyses. To induce inflammation, acute mouse striatal slices were incubated with lipopolysaccharide (LPS). Here we report that LPS treatment potentiated AMPA responses only in D2 SPNs. When a nonspecific VGCC blocker was included, we observed a decrease of AMPA‐stimulated calcium fluorescence in D2 but not D1 SPNs. The remaining agonist‐induced [Ca2+]i was mediated by calcium‐permeable AMPARs because the responses were completely blocked by a selective calcium‐permeable AMPAR antagonist. We used isradipine, the highly selective L‐type VGCC antagonist to determine the role of L‐type VGCCs in SPNs treated with LPS. Isradipine decreased AMPA‐stimulated responses selectively in D2 SPNs after LPS treatment. Our findings suggest that dorsal striatal D2 SPNs are specifically targeted in proinflammatory conditions and that L‐type VGCCs and calcium‐permeable AMPARs are important mediators of this effect.
The effects of dynamical synapses on firing rate activity: a spiking neural network model
Authors: Khalil Radwa , Moftah Marie Z. , Moustafa Ahmed A. 
Published: September 2017

AbstractAccumulating evidence relates the fine‐tuning of synaptic maturation and regulation of neural network activity to several key factors, including GABAA signaling and a lateral spread length between neighboring neurons (i.e., local connectivity). Furthermore, a number of studies consider short‐term synaptic plasticity (STP) as an essential element in the instant modification of synaptic efficacy in the neuronal network and in modulating responses to sustained ranges of external Poisson input frequency (IF). Nevertheless, evaluating the firing activity in response to the dynamical interaction between STP (triggered by ranges of IF) and these key parameters in vitro remains elusive. Therefore, we designed a spiking neural network (SNN) model in which we incorporated the following parameters: local density of arbor essences and a lateral spread length between neighboring neurons. We also created several network scenarios based on these key parameters. Then, we implemented two classes of STP: (1) short‐term synaptic depression (STD) and (2) short‐term synaptic facilitation (STF). Each class has two differential forms based on the parametric value of its synaptic time constant (either for depressing or facilitating synapses). Lastly, we compared the neural firing responses before and after the treatment with STP. We found that dynamical synapses (STP) have a critical differential role on evaluating and modulating the firing rate activity in each network scenario. Moreover, we investigated the impact of changing the balance between excitation (E) and inhibition (I) on stabilizing this firing activity.
FoxP expression identifies a Kenyon cell subtype in the honeybee mushroom bodies linking them to fruit fly αβc neurons
Authors: Schatton Adriana , Scharff Constance 
Published: September 2017

AbstractThe arthropod mushroom bodies (MB) are a higher order sensory integration centre. In insects, they play a central role in associative olfactory learning and memory. In Drosophila melanogaster (Dm), the highly ordered connectivity of heterogeneous MB neuron populations has been mapped using sophisticated molecular genetic and anatomical techniques. The MB‐core subpopulation was recently shown to express the transcription factor FoxP with relevance for decision‐making. Here, we report the development and adult distribution of a FoxP‐expressing neuron population in the MB of honeybees (Apis mellifera, Am) using in situ hybridisation and a custom‐made antiserum. We found the same expression pattern in adult bumblebees (Bombus terrestris, Bt). We also designed a new Dm transgenic line that reports FoxP transcriptional activity in the MB‐core region, clarifying previously conflicting data of two other reporter lines. Considering developmental, anatomical and molecular similarities, our data are consistent with the concept of deep homology of FoxP expression in neuron populations coding reinforcement‐based learning and habit formation.