bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of short‐duration resistance training on insulin sensitivity and muscle adaptations in overweight men
Authors: Ismail Ahmad D. , Alkhayl Faris F. Aba , Wilson John , Johnston Lynsey , Gill Jason M. R. , Gray Stuart R. 
Published: January 2019

New Findings
What is the central question of this study?
What is the time course of muscular adaptations to short‐duration resistance exercise training?

What is the main finding and its importance?
Short‐duration resistance training results in early and progressive increases in muscle mass and function and an increase in insulin sensitivity.

AbstractThe aim of the study was to investigate the effects of 6 weeks of resistance exercise training, composed of one set of each exercise to voluntary failure, on insulin sensitivity and the time course of adaptations in muscle strength/mass. Ten overweight men (age 36 ± 8 years; height 175 ± 9 cm; weight 89 ± 14 kg; body mass index 29 ± 3 kg m−2) were recruited to the study. Resistance exercise training involved three sessions per week for 6 weeks. Each session involved one set of nine exercises, performed at 80% of one‐repetition maximum to volitional failure. Sessions lasted 15–20 min. Oral glucose tolerance tests were performed at baseline and post‐intervention. Vastus lateralis muscle thickness, knee‐extensor maximal isometric torque and rate of torque development (measured between 0 and 50, 0 and 100, 0 and 200, and 0 and 300 ms) were measured at baseline, each week of the intervention, and after the intervention. Resistance training resulted in a 16.3 ± 18.7% (P < 0.05) increase in insulin sensitivity (Cederholm index). Muscle thickness, maximal isometric torque and one‐repetition maximum increased with training, and at the end of the intervention were 10.3 ± 2.5, 26.9 ± 8.3, 18.3 ± 4.5% higher (P < 0.05 for both) than baseline, respectively. The rate of torque development at 50 and 100 ms, but not at 200 and 300 ms, increased (P < 0.05) over the intervention period. Six weeks of single‐set resistance exercise to failure results in improvements in insulin sensitivity and increases in muscle size and strength in young overweight men.
BlockQuicksort
Authors: Edelkamp Stefan , Weiß Armin 
Published: January 2019

It is well known that Quicksort -- which is commonly considered as one of the fastest in-place sorting algorithms -- suffers in an essential way from branch mispredictions. We present a novel approach to addressing this problem by partially decoupling control from dataflow: in order to perform the partitioning, we split the input into blocks of constant size. Then, all elements in one block are compared with the pivot and the outcomes of the comparisons are stored in a buffer. In a second pass, the respective elements are rearranged. By doing so, we avoid conditional branches based on outcomes of comparisons (except for the final Insertionsort). Moreover, we prove that when sorting
n
elements, the average total number of branch mispredictions is at most ϵ
n
log
n
+
O
(
n
) for some small ϵ depending on the block size.

Our experimental results are promising: when sorting random-integer data, we achieve an increase in speed (number of elements sorted per second) of more than 80% over the GCC implementation of Quicksort (C++ std::sort). Also, for many other types of data and non-random inputs, there is still a significant speedup over std::sort. Only in a few special cases, such as sorted or almost sorted inputs, can std::sort beat our implementation. Moreover, on random-input permutations, our implementation is even slightly faster than an implementation of the highly tuned Super Scalar Sample Sort, which uses a linear amount of additional space.
Finally, we also apply our approach to Quickselect and obtain a speed-up of more than 100% over the GCC implementation (C++ std::nth_element).
Doxapram stimulates respiratory activity through distinct activation of neurons in the nucleus hypoglossus and the pre-Bötzinger complex
Authors: Kruszynski Sandra , Stanaitis Kornelijus , Brandes Janine , Poets Christian F. , Koch Henner 
Published: January 2019

Doxapram is a respiratory stimulant used for decades as a treatment option in apnea of prematurity refractory to methylxanthine treatment. Its mode of action, however, is still poorly understood. We investigated direct effects of doxapram on the pre-Bötzinger complex (PreBötC) and on a downstream motor output system, the hypoglossal nucleus (XII), in the transverse brainstem slice preparation. While doxapram has only a modest stimulatory effect on frequency of activity generated within the PreBötC, a much more robust increase in the amplitude of population activity in the subsequent motor output generated in the XII was observed. In whole cell patch-clamp recordings of PreBötC and XII neurons, we confirmed significantly increased firing of evoked action potentials in XII neurons in the presence of doxapram, while PreBötC neurons showed no significant alteration in firing properties. Interestingly, the amplitude of activity in the motor output was not increased in the presence of doxapram compared with control conditions during hypoxia. We conclude that part of the stimulatory effects of doxapram is caused by direct input on brainstem centers with differential effects on the rhythm generating kernel (PreBötC) and the downstream motor output (XII).NEW & NOTEWORTHY The clinically used respiratory stimulant doxapram has distinct effects on the rhythm generating kernel (pre-Bötzinger complex) and motor output centers (nucleus hypoglossus). These effects are obliterated during hypoxia and are mediated by distinct changes in the intrinsic properties of neurons of the nucleus hypoglossus and synaptic transmission received by pre-Bötzinger complex neurons.
Age-related reweighting of visual and vestibular cues for vertical perception
Authors: Alberts Bart B. G. T. , Selen Luc P. J. , Medendorp W. Pieter 
Published: January 2019

As we age, the acuity of our sensory organs declines, which may affect our lifestyle. Sensory deterioration in the vestibular system is typically bilateral and gradual, and could lead to problems with balance and spatial orientation. To compensate for the sensory deterioration, it has been suggested that the brain reweights the sensory information sources according to their relative noise characteristics. For rehabilitation and training programs, it is important to understand the consequences of this reweighting, preferably at the individual subject level. We psychometrically examined the age-dependent reweighting of visual and vestibular cues used in spatial orientation in a group of 32 subjects (age range: 19–76 yr). We asked subjects to indicate the orientation of a line (clockwise or counterclockwise relative to the gravitational vertical) presented within an oriented square visual frame when seated upright or with their head tilted 30° relative to the body. Results show that subjects’ vertical perception is biased by the orientation of the visual frame. Both the magnitude of this bias and response variability become larger with increasing age. Deducing the underlying sensory noise characteristics, using Bayesian inference, suggests an age-dependent reweighting of sensory information, with an increasing weight of the visual contextual information. Further scrutiny of the model suggests that this shift in sensory weights is the result of an increase in the noise of the vestibular signal. Our approach quantifies how noise properties of visual and vestibular systems change over the life span, which helps to understand the aging process at the neurocomputational level.NEW & NOTEWORTHY Perception of visual vertical involves a weighted fusion of visual and vestibular tilt cues. Using a Bayesian approach and experimental psychophysics, we quantify how this fusion process changes with age. We show that, with age, the vestibular information is down-weighted whereas the visual weight is increased. This shift in sensory reweighting is primarily due to an age-related increase of the noise of vestibular signals.
Temporal cueing enhances neuronal and behavioral discrimination performance in rat whisker system
Authors: Lee Conrad C. Y. , Clifford Colin W. G. , Arabzadeh Ehsan 
Published: January 2019

Since sensory systems operate with a finite quantity of processing resources, an animal would benefit from prioritizing processing of sensory stimuli within a time window that is expected to provide key information. This behavioral manifestation of such prioritization is known as attention. Here, we investigate attention with temporal cueing and its neuronal correlates in the rat primary vibrissal somatosensory (vS1) cortex. Rats were trained in a simple whisker vibration detection task. A vibration was presented at one of two spatial locations (left or right), sometimes after an unknown time interval and sometimes after receiving an auditory cue. The auditory cue provided temporal but not spatial information about the vibration. We found that for all rats ( n = 6), the auditory cue consistently enhanced detection of the vibration stimulus. Neuronal activity in vS1 cortex reflected the observed behavioral enhancement from temporal cueing with single units responded differentially to the whisker vibration stimulus when it was temporally predicted by the auditory cue, exhibiting an enhanced signal-to-noise ratio. Our findings indicate that rats are capable of prioritizing processing within a specified time window and provide evidence that the primary sensory cortex may participate in the temporal allocation of resources. NEW & NOTEWORTHY We demonstrate a novel paradigm of temporal cueing in rats. In a two-alternative whisker detection task, an auditory cue provided information about the timing of the stimulus but not the correct choice. In the presence of cue, detection was faster and more accurate, and neuronal activity from the primary somatosensory cortex revealed enhanced representation of vibrations. These results thus establish the rat as an alternative model organism to primates for studying temporal attention.
Theta/delta coupling across cortical laminae contributes to semantic cognition
Authors: Adams Natalie E. , Teige Catarina , Mollo Giovanna , Karapanagiotidis Theodoros , Cornelissen Piers L. , Smallwood Jonathan , Traub Roger D. , Jefferies Elizabeth , Whittington Miles A. 
Published: January 2019

Rhythmic activity in populations of neurons is associated with cognitive and motor function. Our understanding of the neuronal mechanisms underlying these core brain functions has benefitted from demonstrations of cellular, synaptic, and network phenomena, leading to the generation of discrete rhythms at the local network level. However, discrete frequencies of rhythmic activity rarely occur alone. Despite this, little is known about why multiple rhythms are generated together or what mechanisms underlie their interaction to promote brain function. One overarching theory is that different temporal scales of rhythmic activity correspond to communication between brain regions separated by different spatial scales. To test this, we quantified the cross-frequency interactions between two dominant rhythms—theta and delta activity—manifested during magnetoencephalography recordings of subjects performing a word-pair semantic decision task. Semantic processing has been suggested to involve the formation of functional links between anatomically disparate neuronal populations over a range of spatial scales, and a distributed network was manifest in the profile of theta-delta coupling seen. Furthermore, differences in the pattern of theta-delta coupling significantly correlated with semantic outcome. Using an established experimental model of concurrent delta and theta rhythms in neocortex, we show that these outcome-dependent dynamics could be reproduced in a manner determined by the strength of cholinergic neuromodulation. Theta-delta coupling correlated with discrete neuronal activity motifs segregated by the cortical layer, neuronal intrinsic properties, and long-range axonal targets. Thus, the model suggested that local, interlaminar neocortical theta-delta coupling may serve to coordinate both cortico-cortical and cortico-subcortical computations during distributed network activity. NEW & NOTEWORTHY Here, we show, for the first time, that a network of spatially distributed brain regions can be revealed by cross-frequency coupling between delta and theta frequencies in subjects using magnetoencephalography recording during a semantic decision task. A biological model of this cross-frequency coupling suggested an interlaminar, cell-specific division of labor within the neocortex may serve to route the flow of cortico-cortical and cortico-subcortical information to promote such spatially distributed, functional networks.
Effects of tonic muscle pain on fusimotor control of human muscle spindles during isometric ankle dorsiflexion
Authors: Smith Lyndon J. , Macefield Vaughan G. , Birznieks Ingvars , Burton Alexander R. 
Published: January 2019

Studies on anesthetized animals have revealed that nociceptors can excite fusimotor neurons and thereby change the sensitivity of muscle spindles to stretch; such nociceptive reflexes have been suggested to underlie the mechanisms that lead to chronic musculoskeletal pain syndromes. However, the validity of the “vicious cycle” hypothesis in humans has yielded results contrasting with those found in animals. Given that spindle firing rates are much lower in humans than in animals, it is possible that some of the discrepancies between human experimental data and those obtained in animals could be explained by differences in background fusimotor drive when the leg muscles are relaxed. We examined the effects of tonic muscle pain during voluntary contractions of the ankle dorsiflexors. Unitary recordings were obtained from 10 fusimotor-driven muscle spindle afferents (6 primary, 4 secondary) supplying the ankle dorsiflexors via a microelectrode inserted percutaneously into the common peroneal nerve. A series of 1-min weak contractions was performed at rest and during 1 h of muscle pain induced by intramuscular infusion of 5% hypertonic saline into the tibialis anterior muscle. We did not observe any statistically significant increases in muscle spindle firing rates of six afferents followed during tonic muscle pain, although discharge variability increased slightly. Furthermore, a participant’s capacity to maintain a constant level of force, while relying on proprioceptive feedback in the absence of visual feedback, was not compromised during pain. We conclude that nociceptive inputs from contracting muscle do not excite fusimotor neurons during voluntary isometric contractions in humans. NEW & NOTEWORTHY Data obtained in the cat have shown that muscle pain causes a marked increase in the firing of muscle spindles, attributed to a nociceptor-driven fusimotor reflex. However, our studies of muscle spindles in relaxed leg muscles failed to find any effect on spindle discharge. Here we showed that experimental muscle pain failed to increase the firing of muscle spindle afferents during weak voluntary contractions, when fusimotor drive sufficient to increase their firing is present.
Clearance of Magnesium in Peritoneal Dialysis Patients: A Single-Center Study
Authors: Li Guiyan , Zhang Li , Ren Haibin , Huang Baodi , Mao Chunxia , Zhou Annan 
Published: January 2019

<b><i>Objective:</i></b> This retrospective study aimed to investigate the clearance of magnesium (Mg) in peritoneal dialysis (PD) patients and its influencing factors. <b><i>Methods:</i></b> The demographic information, clinical characteristics and laboratory data of the patients were collected. According to the corrected serum Mg (cS-Mg) concentration, patients were divided into 3 groups including hypomagnesemia (Mg<sup>2+</sup> &#x3c; 0.77 mmol/L, group A), normal serum Mg concentration (0.77 mmol/L ≤ Mg<sup>2+</sup> ≤1.03 mmol/L, group B), and hypermagnesemia (Mg<sup>2+</sup> &#x3e; 1.03 mmo/L, group C). <b><i>Results:</i></b> One hundred and fifteen patients were enrolled, and their mean 24 h-peritoneal Mg clearance was 39.75 ± 17.42 mg. The mean normalized peritoneal Mg clearance rate was 1.82 ± 0.82 L/day/1.73 m<sup>2</sup>. Twenty-four-hour peritoneal Mg clearance of group A was significantly lower than that of group C (<i>p</i> &#x3c; 0.05). Bivariate correlation analysis showed that cS-Mg was positively correlated with peritoneal dialysate Mg concentration (<i>p</i> &#x3c; 0.01). cS-Mg was negatively correlated with the normalized peritoneal Mg clearance rate (<i>p</i> &#x3c; 0.05). The normalized peritoneal Mg clearance rate was positively correlated with prealbumin (<i>p</i> &#x3c; 0.05), daily peritoneal protein loss (<i>p</i> &#x3c; 0.01) and the normalized PD-creatinine clearance rate (<i>p</i> &#x3c; 0.01). The normalized peritoneal Mg clearance rate was also negatively correlated with the normalized renal-creatinine clearance rate (<i>p</i> &#x3c; 0.01). Furthermore, cS-Mg of patients with continuous ambulatory PD (CAPD) was significantly lower than that of patients with daytime ambulatory PD (DAPD, <i>p</i> &#x3c; 0.01). The normalized peritoneal Mg clearance rate of patients with CAPD was significantly higher than that of patients with DAPD (<i>p</i> &#x3c; 0.01). Moreover, among the patients with different peritoneal transport characteristics of peritoneal equilibration test, the normalized peritoneal Mg clearance rate of high average transport patients was significantly higher than that in those with low transport, low average transport and high transport (<i>p</i> &#x3c; 0.05). <b><i>Conclusions:</i></b> Serum Mg could be partly cleared by PD. The peritoneal Mg clearance was positively related with serum Mg concentration, which was concentration-dependent. Peritoneal Mg clearance was negatively correlated with the residual renal function, while being positively correlated with the nutritional status and daily peritoneal protein loss. Peritoneal Mg clearance was higher in patients with high transport characteristics or CAPD.
Sclerostin/Receptor Related Protein 4 and Ginkgo Biloba Extract Alleviates β-Glycerophosphate-Induced Vascular Smooth Muscle Cell Calcification By Inhibiting Wnt/β-Catenin Pathway
Authors: Wang Jian , Qiu Xiaobo , Xu Tianhua , Sheng Zitong , Yao Li 
Published: January 2019

<b><i>Background:</i></b> Abnormal mineral metabolism in patients with chronic kidney disease (CKD) may lead to vascular calcification, which is markedly associated with adverse events, including ischemic cardiac diseases and all-cause cardiovascular mortality. Thus, preventing and treating vascular calcification play an important role in improving the prognosis of CKD patients. <b><i>Objectives:</i></b> To investigate the potential functions of sclerostin and low-density lipoprotein receptor-related protein 4 (Lrp4) in alleviating the β-glycerophosphate (β-GP)-induced vascular smooth muscle cell (VSMC) calcification, and the protective effect of Ginkgo biloba extract (GBE). <b><i>Methods:</i></b> VSMC were extracted from Sprague-Dawley rat aorta and cultured in medium. The VSMCs were divided into 3 groups: (1) Negative control group, (2) β-GP group, in which the VSMCs were treated with β-GP, and (3) GBE and β-GP group, where the VSMCs were treated with both β-GP and GBE. The calcium nodules within the cells were examined by using Alizarin red S staining. The mRNA expression levels of β-catenin and bone gamma-carboxyglutamic-acid-containing proteins (BGP) were detected by real-time PCR. The protein levels of sclerostin and Lrp4 were determined by Western blot. <b><i>Results:</i></b> Alizarin red S staining showed that the VSMCs in β-GP group had a distinct orange-red precipitate when compared with VSMCs in the negative control group, while the orange-red precipitate of the GBE and β-GP group was significantly reduced compared to the β-GP group. Real-time PCR showed that the mRNA levels of β-catenin and BGP in VSMCs of β-GP group were significantly higher than those of the negative control group (<i>p</i> &#x3c; 0.05); while they were significantly reduced in VSMCs of the GBE and β-GP group (<i>p</i> &#x3c; 0.05). Western blot results showed that the expression of sclerostin in the β-GP group was significantly higher than that in the control group (<i>p</i> &#x3c; 0.05), whereas Lrp4 was significantly lower than in control group (<i>p</i> &#x3c; 0.05). Sclerostin in GBE and β-GP group was significantly reduced (<i>p</i> &#x3c; 0.05), but Lrp4 was significantly elevated when compared with that of the β-GP group (<i>p</i> &#x3c; 0.05). <b><i>Conclusion:</i></b> β-GP induced VSMC calcification by activating the Wnt/β-catenin signaling pathway. Sclerostin and Lrp4 were involved in β-GP-induced VSMC calcification and play an important role. GBE could alleviate VSMC calcification induced by β-GP through inhibiting the Wnt/β-catenin signaling pathway.
C-X-C Motif Chemokine Receptor 4 Blockade Promotes Tissue Repair After Myocardial Infarction by Enhancing Regulatory T Cell Mobilization and Immune-Regulatory Function
Authors: Wang Yong , Dembowsky Klaus , Chevalier Eric , Stüve Philipp , Korf-Klingebiel Mortimer , Lochner Matthias , Napp L. Christian , Frank Heike , Brinkmann Eva , Kanwischer Anna , Bauersachs Johann , Gyöngyösi Mariann , Sparwasser Tim , Wollert Kai C. 
Published: January 2019

Background:
Acute myocardial infarction (MI) elicits an inflammatory response that drives tissue repair and adverse cardiac remodeling. Inflammatory cell trafficking after MI is controlled by C-X-C motif chemokine ligand 12 (CXCL12) and its receptor, C-X-C motif chemokine receptor 4 (CXCR4). CXCR4 antagonists mobilize inflammatory cells and promote infarct repair, but the cellular mechanisms are unclear.

Methods:

We investigated the therapeutic potential and mode of action of the peptidic macrocycle CXCR4 antagonist POL5551 in mice with reperfused MI. We applied cell depletion and adoptive transfer strategies using lymphocyte-deficient
Rag1
knockout mice; DEREG mice, which express a diphtheria toxin receptor–enhanced green fluorescent protein fusion protein under the control of the promoter/enhancer region of the regulatory T (T
reg
) cell–restricted Foxp3 transcription factor; and dendritic cell-depleted CD11c-Cre iDTR mice. Translational potential was explored in a porcine model of reperfused MI using serial contrast-enhanced magnetic resonance imaging.

Results:

Intraperitoneal POL5551 injections in wild-type mice (8 mg/kg at 2, 4, 6, and 8 days) enhanced angiogenesis in the infarct border zone, reduced scar size, and attenuated left ventricular remodeling and contractile dysfunction at 28 days. Treatment effects were absent in splenectomized wild-type mice,
Rag1
knockout mice, and T
reg
cell–depleted DEREG mice. Conversely, treatment effects could be transferred into infarcted splenectomized wild-type mice by transplanting splenic T
reg
cells from POL5551-treated infarcted DEREG mice. Instructive cues provided by infarct-primed dendritic cells were required for POL5551 treatment effects. POL5551 injections mobilized T
reg
cells into the peripheral blood, followed by enhanced T
reg
cell accumulation in the infarcted region. Neutrophils, monocytes, and lymphocytes displayed similar mobilization kinetics, but their cardiac recruitment was not affected. POL5551, however, attenuated inflammatory gene expression in monocytes and macrophages in the infarcted region via T
reg
cells. Intravenous infusion of the clinical-stage POL5551 analogue POL6326 (3 mg/kg at 4, 6, 8, and 10 days) decreased infarct volume and improved left ventricular ejection fraction in pigs.

Conclusions:

These data confirm CXCR4 blockade as a promising treatment strategy after MI. We identify dendritic cell–primed splenic T
reg
cells as the central arbiters of these therapeutic effects and thereby delineate a pharmacological strategy to promote infarct repair by augmenting T
reg
cell function in vivo.