bluuebunny/crossref_metadata_2025_split huggingface dataset:
Motor adaptations to unilateral quadriceps fatigue during a bilateral pedaling task
Authors: Brøchner Nielsen N.‐P. , Hug F. , Guével A. , Fohanno V. , Lardy J. , Dorel S. 
Published: December 2016

This study was designed to investigate how motor coordination adapts to unilateral fatigue of the quadriceps during a constant‐load bilateral pedaling task. We first hypothesized that this local fatigue would not be compensated within the fatigued muscles leading to a decreased knee extension power. Then, we aimed to determine whether this decrease would be compensated by between‐joints compensations within the ipsilateral leg and/or an increased contribution of the contralateral leg. Fifteen healthy volunteers were tested during pedaling at 350 W before and after a fatigue protocol consisting of 15 minutes of electromyostimulation on the quadriceps muscle. Motor coordination was assessed from myoelectrical activity (22 muscles) and joint powers calculated through inverse dynamics. Maximal knee extension torque decreased by 28.3%±6.8% (P<.0005) immediately after electromyostimulation. A decreased knee extension power produced by the ipsilateral leg was observed during pedaling (−22.8±12.3 W, −17.0%±9.4%; P<.0005). To maintain the task goal, participants primarily increased the power produced by the non‐fatigued contralateral leg during the flexion phase. This was achieved by an increase in hip flexion power confirmed by a higher activation of the tensor fascia latae. These results suggest no adjustment of neural drive to the fatigued muscles and demonstrate no concurrent ipsilateral compensation by the non‐fatigued muscles involved in the extension pedaling phase. Although interindividual variability was observed, findings provide evidence that participants predominantly adapted by compensating with the contralateral leg during its flexion phase. Both neural (between legs) and mechanical (between pedals) couplings and the minimization of cost functions might explain these results.
Discriminating the hemolytic risk of blood type A plasmas using the complement hemolysis using human erythrocytes (CHUHE) assay
Authors: Cunnion Kenji M. , Hair Pamela S. , Krishna Neel K. , Sass Megan A. , Enos Clinton W. , Whitley Pamela H. , Maes Lanne Y. , Goldberg Corinne L. 
Published: December 2016

BACKGROUNDThe agglutination‐based cross‐matching method is sensitive for antibody binding to red blood cells but is only partially predictive of complement‐mediated hemolysis, which is important in many acute hemolytic transfusion reactions. Here, we describe complement hemolysis using human erythrocytes (CHUHE) assays that directly evaluate complement‐mediated hemolysis between individual serum‐plasma and red blood cell combinations. The CHUHE assay is used to evaluate correlations between agglutination titers and complement‐mediated hemolysis as well as the hemolytic potential of plasma from type A blood donors.STUDY DESIGN AND METHODSPlasma or serum from each type A blood donor was incubated with AB or B red blood cells in the CHUHE assay and measured for free hemoglobin release.RESULTSCHUHE assays for serum or plasma demonstrate a wide, dynamic range and high sensitivity for complement‐mediated hemolysis for individual serum/plasma and red blood cell combinations. CHUHE results suggest that agglutination assays alone are only moderately predictive of complement‐mediated hemolysis. CHUHE results also suggest that plasma from particular type A blood donors produce minimal complement‐mediated hemolysis, whereas plasma from other type A blood donors produce moderate to high‐level complement‐mediated hemolysis, depending on the red blood cell donor.CONCLUSIONThe current results indicate that the CHUHE assay can be used to assess complement‐mediated hemolysis for plasma or serum from a type A blood donor, providing additional risk discrimination over agglutination titers alone.
Impact of platelet pathogen inactivation on blood component utilization and patient safety in a large Austrian Regional Medical Centre
Authors: Amato M. , Schennach H. , Astl M. , Chen C. Y. , Lin J.‐S. , Benjamin R. J. , Nussbaumer W. 
Published: December 2016

BackgroundIn clinical studies, pathogen inactivation (PI) of platelet concentrates (PC) with amotosalen and UVA light did not impact patient risk for haemorrhage but may affect transfusion frequency and component utilization. We evaluated the influence of platelet PI on PC, red cell concentrate (RCC) and plasma use and safety in routine practice in a large regional hospital.Study Design and MethodsComparative effectiveness of conventional vs. PI‐treated PC was analysed during two 21‐month periods, before and after PI implementation.ResultsSimilar numbers of patients were transfused in the pre‐PI (control, 1797) and post‐PI (test, 1694) periods with comparable numbers of PC (8611 and 7705, respectively). The mean numbers of PC per patient transfused (4·8 vs. 4·5, P = 0·43) were not different but days of PC support (5·9 vs. 5·0, P < 0·01) decreased. Most patients received RCC (86·8% control vs. 84·8% test, P = 0·90) with similar mean numbers transfused (10·8 vs. 10·2 RCC, P = 0·22), and fewer patients (55·4% control vs. 44·7% test, P < 0·01) received less plasma units (mean 9·9 vs. 7·8, respectively, P < 0·01) in the test period. The frequencies of transfusion‐related adverse events (AE) were comparable (1·3% vs. 1·4%, P = 0·95). Analysis of haematology–oncology (522 control, 452 test), cardiac surgery (739 control, 711 test), paediatric (157 control, 130 test) and neonate (23 control, 20 test) patients revealed no increase in PC, plasma and RCC utilization, or AE.ConclusionComponent utilization and patient safety were not impacted by adoption of PI for PC. RCC use per patient was comparable, suggestive of no increase in significant bleeding.
Experiences with semi‐routine production of riboflavin and UV‐B pathogen‐inactivated platelet concentrates in three blood centres
Authors: van der Meer P. F. , Couture C. , Hervig T. , Kruit G. , Devine D. V. , de Korte D. , Kerkhoffs J.‐L. 
Published: December 2016

BackgroundFor a clinical platelet (PLT) transfusion trial conducted in three countries, the production of PLT concentrates (PCs) that were pathogen inactivated with the Mirasol technology was set up and validated. While the Mirasol procedure is applied to an established PLT product, the PLT processing procedure still had to be modified to ensure a treated PC was of sufficient quality. Further, the effect of simulated transport conditions and the effect of ambient light on Mirasol‐treated PCs was determined.Study Design and MethodsPlatelet concentrates in plasma were made from pooled buffy coats followed by Mirasol treatment. To mimic transport conditions, units were left unagitated for 6 h at room temperature. To mimic ambient light exposure, units were held unagitated for 4 h in direct fluorescent tube light.ResultsMeasures had to be taken to allow 7‐day storage of treated concentrates. In one site, PCs made from five buffy coats with >450 × 109 PLTs were removed from inventory. Another site went from five to four buffy coats per pool. Interruption of agitation for 6 h on day 3 did not induce meaningful changes in in vitro measures, even when stored up to 7 days. Exposure to ambient light for 4 h, either on day 3 or 6, had no effect on in vitro measures.ConclusionThe Mirasol pathogen inactivation process can be implemented in routine, but changes to current PLT processing methods might be needed. Transport conditions and 4‐h‐long ambient light exposure have no negative effect on the in vitro quality of Mirasol‐treated PCs.
Storage of red blood cells in a novel polyolefin blood container: a pilot in vitro study
Authors: Gulliksson H. , Meinke S. , Ravizza A. , Larsson L. , Höglund P. 
Published: December 2016

Background and ObjectivesThe present general plasticizer di‐2‐ethylhexyl‐phthalate in polyvinylchloride (PVC) blood bags is only physically dispersed in PVC and will therefore leach into blood components. The objective of this study was to perform a first preliminary red blood cell (RBC) storage evaluation in a new blood bag manufactured of polyolefin without any inclusion of potentially migrating substances.Study Design and MethodsThis is a RBC storage study for 42 days. Blood collection was performed in a polyolefin‐based PVC‐free blood bag. RBCs were prepared within 8 h. Two different RBC additive solutions were used, either PAGGS‐M or PAGGG‐M. We weekly measured pH, K+, glucose, lactate, haemolysis, red cell ATP and 2,3‐DPG.ResultsRBC storage in PAGGS‐M resulted in high haemolysis levels already after 21 days, exceeding the European maximum limit of 0·8%, and low ATP levels by the end of the storage period. With PAGGG‐M, haemolysis exceeded 0·8% after 28 days of storage. For additional parameters, the results were comparable to those of previous studies in conventional blood bags.ConclusionThis is a first preliminary study of RBC storage in a new type of blood bags. PAGGG‐M gave encouraging results except for its inability to prevent increased haemolysis. There will be room for further development of RBC additive solutions to address the haemolysis problems. Plasma should also be tested regarding the stability of coagulation and activation pathway variables. There may also be a potential for future use of the bag for preparation of pooled buffy‐coat‐derived platelets.
Critical re‐appraisal of blood component quality after overnight hold of whole blood outside current room temperature limits
Authors: Bontekoe I. J. , van der Meer P. F. , de Korte D. 
Published: December 2016

Background and ObjectivesAccording to European guidelines, the temperature of whole blood (WB) has to be maintained at 20–24°C until processing within 24 h, but in blood bank practice, WB is frequently held at temperatures between 18–25°C. We aimed to assess the impact of these small temperature deviations on the quality of the blood components.Materials and MethodsAfter rapid cooling, 7 WB units were held overnight at 18°C and 8 units at 25°C, reflecting worst case holding conditions, and separated into a red cell concentrate (RCC), plasma and buffy coat (BC). RCCs were filtered at test temperature and stored for 42 days at 2–6°C. BCs were processed to single‐BC platelet concentrates (sPC) and stored up to Day 8 at 20–24°C.ResultsAfter overnight hold at 18°C, 2,3‐DPG in WB decreased by 34 ± 9%, while at 25°C the decrease was 82 ± 6%. Accordingly, the 2,3‐DPG levels in the RCCs in the 25°C group were significantly lower than in the 18°C group (2·2 ± 1·4 vs. 10·4 ± 2·9 μmol/g Hb). RCCs and sPCs in the 25°C group showed higher initial lactate levels and lower pH compared to the 18°C group, but these differences levelled off at the end of storage. RCCs showed small differences in ATP levels and haemolysis. Plasma in both groups showed comparable Factor VIII:C levels.ConclusionThe temperature of WB during overnight hold strongly affects initial 2,3‐DPG levels of RCCs and supports the maintenance of temperature limits between 20 and 24°C. Other in vitro effects of the temperature deviations were small and of no practical relevance.
Firedrake
Authors: Rathgeber Florian , Ham David A. , Mitchell Lawrence , Lange Michael , Luporini Fabio , Mcrae Andrew T. T. , Bercea Gheorghe-Teodor , Markall Graham R. , Kelly Paul H. J. 
Published: December 2016

Firedrake is a new tool for automating the numerical solution of partial differential equations. Firedrake adopts the domain-specific language for the finite element method of the FEniCS project, but with a pure Python runtime-only implementation centered on the composition of several existing and new abstractions for particular aspects of scientific computing. The result is a more complete separation of concerns that eases the incorporation of separate contributions from computer scientists, numerical analysts, and application specialists. These contributions may add functionality or improve performance.
Firedrake benefits from automatically applying new optimizations. This includes factorizing mixed function spaces, transforming and vectorizing inner loops, and intrinsically supporting block matrix operations. Importantly, Firedrake presents a simple public API for escaping the UFL abstraction. This allows users to implement common operations that fall outside of pure variational formulations, such as flux limiters.
Muscarinic acetylcholine receptors control baseline activity and Hebbian stimulus timing-dependent plasticity in fusiform cells of the dorsal cochlear nucleus
Authors: Stefanescu Roxana A. , Shore Susan E. 
Published: December 2016

Cholinergic modulation contributes to adaptive sensory processing by controlling spontaneous and stimulus-evoked neural activity and long-term synaptic plasticity. In the dorsal cochlear nucleus (DCN), in vitro activation of muscarinic acetylcholine receptors (mAChRs) alters the spontaneous activity of DCN neurons and interacts with N-methyl-d-aspartate (NMDA) and endocannabinoid receptors to modulate the plasticity of parallel fiber synapses onto fusiform cells by converting Hebbian long-term potentiation to anti-Hebbian long-term depression. Because noise exposure and tinnitus are known to increase spontaneous activity in fusiform cells as well as alter stimulus timing-dependent plasticity (StTDP), it is important to understand the contribution of mAChRs to in vivo spontaneous activity and plasticity in fusiform cells. In the present study, we blocked mAChRs actions by infusing atropine, a mAChR antagonist, into the DCN fusiform cell layer in normal hearing guinea pigs. Atropine delivery leads to decreased spontaneous firing rates and increased synchronization of fusiform cell spiking activity. Consistent with StTDP alterations observed in tinnitus animals, atropine infusion induced a dominant pattern of inversion of StTDP mean population learning rule from a Hebbian to an anti-Hebbian profile. Units preserving their initial Hebbian learning rules shifted toward more excitatory changes in StTDP, whereas units with initial suppressive learning rules transitioned toward a Hebbian profile. Together, these results implicate muscarinic cholinergic modulation as a factor in controlling in vivo fusiform cell baseline activity and plasticity, suggesting a central role in the maladaptive plasticity associated with tinnitus pathology. NEW & NOTEWORTHY This study is the first to use a novel method of atropine infusion directly into the fusiform cell layer of the dorsal cochlear nucleus coupled with simultaneous recordings of neural activity to clarify the contribution of muscarinic acetylcholine receptors (mAChRs) to in vivo fusiform cell baseline activity and auditory-somatosensory plasticity. We have determined that blocking the mAChRs increases the synchronization of spiking activity across the fusiform cell population and induces a dominant pattern of inversion in their stimulus timing-dependent plasticity. These modifications are consistent with similar changes established in previous tinnitus studies, suggesting that mAChRs might have a critical contribution in mediating the maladaptive alterations associated with tinnitus pathology. Blocking mAChRs also resulted in decreased fusiform cell spontaneous firing rates, which is in contrast with their tinnitus hyperactivity, suggesting that changes in the interactions between the cholinergic and GABAergic systems might also be an underlying factor in tinnitus pathology.
Intrinsic functional architecture of the macaque dorsal and ventral lateral frontal cortex
Authors: Goulas Alexandros , Stiers Peter , Hutchison R. Matthew , Everling Stefan , Petrides Michael , Margulies Daniel S. 
Published: December 2016

Investigations of the cellular and connectional organization of the lateral frontal cortex (LFC) of the macaque monkey provide indispensable knowledge for generating hypotheses about the human LFC. However, despite numerous investigations, there are still debates on the organization of this brain region. In vivo neuroimaging techniques such as resting-state functional magnetic resonance imaging (fMRI) can be used to define the functional circuitry of brain areas, producing results largely consistent with gold-standard invasive tract-tracing techniques and offering the opportunity for cross-species comparisons within the same modality. Our results using resting-state fMRI from macaque monkeys to uncover the intrinsic functional architecture of the LFC corroborate previous findings and inform current debates. Specifically, within the dorsal LFC, we show that 1) the region along the midline and anterior to the superior arcuate sulcus is divided in two areas separated by the posterior supraprincipal dimple, 2) the cytoarchitectonically defined area 6DC/F2 contains two connectional divisions, and 3) a distinct area occupies the cortex around the spur of the arcuate sulcus, updating what was previously proposed to be the border between dorsal and ventral motor/premotor areas. Within the ventral LFC, the derived parcellation clearly suggests the presence of distinct areas: 1) an area with a somatomotor/orofacial connectional signature (putative area 44), 2) an area with an oculomotor connectional signature (putative frontal eye fields), and 3) premotor areas possibly hosting laryngeal and arm representations. Our results illustrate in detail the intrinsic functional architecture of the macaque LFC, thus providing valuable evidence for debates on its organization. NEW & NOTEWORTHY Resting-state functional MRI is used as a complementary method to invasive techniques to inform current debates on the organization of the macaque lateral frontal cortex. Given that the macaque cortex serves as a model for the human cortex, our results help generate more fine-tuned hypothesis for the organization of the human lateral frontal cortex.
High-velocity stimulation evokes “dense” population response in layer 2/3 vibrissal cortex
Authors: Ranjbar-Slamloo Yadollah , Arabzadeh Ehsan 
Published: December 2016

Supragranular layers of sensory cortex are known to exhibit sparse firing. In rodent vibrissal cortex, a small fraction of neurons in layer 2 and 3 (L2/3) respond to whisker stimulation. In this study, we combined whole cell recording and two-photon imaging in anesthetized mice and quantified the synaptic response and spiking profile of L2/3 neurons. Previous literature has shown that neurons across layers of vibrissal cortex are tuned to the velocity of whisker movement. We therefore used a broad range of stimuli that included the standard range of velocities (0–1.2 deg/ms) and extended to a “sharp” high-velocity deflection (3.8 deg/ms). Consistent with previous literature, whole cell recording revealed a sparse response to the standard range of velocities: although all recorded cells showed tuning to velocity in their postsynaptic potentials, only a small fraction produced stimulus-evoked spikes. In contrast, the sharp stimulus evoked reliable spiking in the majority of neurons. The action potential threshold of spikes evoked by the sharp stimulus was significantly lower than that of the spontaneous spikes. Juxtacellular recordings confirmed that application of sharp stimulus to single or multiple whiskers produced temporally precise spiking with minimal trial-to-trial spike count variability (Fano factors equal or close to the theoretical minimum). Two-photon imaging further confirmed that most neurons that were not responsive to the standard deflections responded to the sharp stimulus. Altogether, our results indicate that sparseness in L2/3 cortex depends on the choice of stimulus: strong single- or multiwhisker stimulation can induce the transition from sparse to “dense” population response. NEW & NOTEWORTHY In superficial layers of sensory cortex, only a small fraction of neurons fire most of the spontaneous and sensory evoked spikes. However, the functional relevance of such “sparse” activity remains unknown. We found that a “dense” population response is evoked by high-velocity micromotions applied to whiskers. Our results suggest that flashes of precisely timed population response on an almost silent background can provide a high capacity for coding of ecologically salient stimuli.
Rapid and flexible whole body postural responses are evoked from perturbations to the upper limb during goal-directed reaching
Authors: Lowrey Catherine R. , Nashed Joseph Y. , Scott Stephen H. 
Published: December 2016

An important aspect of motor control is the ability to perform tasks with the upper limbs while maintaining whole body balance. However, little is known about the coordination of upper limb voluntary and whole body postural control after mechanical disturbances that require both upper limb motor corrections to attain a behavioral goal and lower limb motor responses to maintain whole body balance. The present study identified the temporal organization of muscle responses and center of pressure (COP) changes following mechanical perturbations during reaching. Our results demonstrate that muscle responses in the upper limb are evoked first (∼50 ms), with lower limb muscle activity occurring immediately after, in as little as ∼60 ms after perturbation. Hand motion was immediately altered by the load, while COP changes occurred after ∼100 ms, when lower limb muscle activity was already present. Our secondary findings showed that both muscle activity and COP changes were influenced by behavioral context (by altering target shape, circle vs. rectangle). Voluntary and postural actions initially directed the hand toward the center of both target types, but after the perturbation upper limb and postural responses redirected the hand toward different spatial locations along the rectangle. Muscle activity was increased for both upper and lower limbs when correcting to the circle vs. the rectangle, and these differences emerged as early as the long-latency epoch (∼75–120 ms). Our results demonstrate that postural responses are rapidly and flexibly altered to consider the behavioral goal of the upper limb. NEW & NOTEWORTHY The present work establishes that, when reaching to a target while standing, perturbations applied to the upper limb elicit a rapid response in lower limb muscles. Unlike voluntary movements, postural responses do not occur before corrections of the upper limb. We show the first evidence that corrective postural adjustments are modulated by upper limb behavioral context (target shape). Importantly, this indicates that postural responses take into account upper limb feedback for online control.