bluuebunny/crossref_metadata_2025 huggingface dataset:
Artificial intelligence for software engineering
Authors: Dam Hoa Khanh
Published: April 2019

Artificial intelligence is predicted to impact many industries (including the software industry), changing how we produce, manufacture, and deliver. The rise of artificial intelligence may significantly transform the practice of software engineering, helping us build better software faster.
That's not fair!
Authors: Raji Deborah
Published: April 2019

Why we need to study machine learning fairness, even in an increasingly unfair world.
Robot, all too human
Authors: Bryson Joanna J.
Published: April 2019

Advanced robotics and artificial intelligence systems present a new challenge to human identity.
A Usability Study of Four Secure Email Tools Using Paired Participants
Authors: Ruoti Scott , Andersen Jeff , Dickinson Luke , Heidbrink Scott , Monson Tyler , O'neill Mark , Reese Ken , Spendlove Brad , Vaziripour Elham , Wu Justin , Zappala Daniel , Seamons Kent
Published: April 2019

Secure email is increasingly being touted as usable by novice users, with a push for adoption based on recent concerns about government surveillance. To determine whether secure email is ready for grassroots adoption, we employ a laboratory user study that recruits pairs of novice users to install and use several of the latest systems to exchange secure messages. We present both quantitative and qualitative results from 28 pairs of novices as they use Private WebMail (Pwm), Tutanota, and Virtru and 10 pairs of novices as they use Mailvelope. Participants report being more at ease with this type of study and better able to cope with mistakes since both participants are “on the same page.” We find that users prefer integrated solutions over depot-based solutions and that tutorials are important in helping first-time users. Finally, our results demonstrate that Pretty Good Privacy using manual key management is still unusable for novice users, with 9 of 10 participant pairs failing to complete the study.
On the Entropy Loss and Gap of Condensers
Authors: Aviv Nir , Ta-Shma Amnon
Published: April 2019

Many algorithms are proven to work under the assumption that they have access to a source of random, uniformly distributed bits. However, in practice, sources of randomness are often imperfect, giving
n
random bits that have only
k
<
n
min-entropy. The value
n
−
k
is called the
entropy gap
of the source.
Randomness condensers
are hash functions that hash any such source to a shorter source with reduced entropy gap
g
. The goal is to lose as little entropy as possible in this process. Condensers also have an error parameter ε and use a small
seed
of uniformly distributed bits whose length we desire to minimize as well.

In this work, we study the exact dependencies between the different parameters of seeded randomness condensers. We obtain a non-explicit upper bound, showing the existence of condensers with entropy loss log (1+log 1/ε /
g
) +
O
(1) and seed length log (
n
−
k
/ ε
g
) +
O
(1). In particular, this implies the existence of condensers with
O
(log 1 / ε) entropy gap and constant entropy loss. This extends (with slightly improved parameters) the non-explicit upper bound for condensers presented in the work of Dodis et al. (2014), which gives condensers with entropy loss at least log log 1 / ε. We also give a non-explicit upper bound for
lossless
condensers, which have entropy gap
g
≥ log 1 / ε / ε +
O
(1) and seed length log (
n
−
k
/ ε
2
g
) +
O
(1).

Furthermore, we address an open question raised in (Dodis et al. 2014), where Dodis et al. showed an
explicit
construction of condensers with constant gap and
O
(log log 1/ ε) loss, using seed length
O
(
n
log 1 / ε). In the same article they improve the seed length to
O
(
k
log
k
) and ask whether it can be further improved. In this work, we reduce the seed length of their construction to
O
(log (
n
/ ε)log (
k
/ &epsiv)) by a simple concatenation.

In the analysis, we use and prove a tight equivalence between condensers and extractors with multiplicative error. We note that a similar, but non-tight, equivalence was already proven by Dodis et al. (Dodis et al. 2014) using a weaker variant of extractors called
unpredictability extractors
. We also remark that this equivalence underlies the work of Ben-Aroya et al. (Ben-Aroya et al. 2016) and later work on explicit two-source extractors, and we believe it is interesting in its own right.
A Self-aware Resource Management Framework for Heterogeneous Multicore SoCs with Diverse QoS Targets
Authors: Song Yang , Alavoine Olivier , Lin Bill
Published: April 2019

In modern heterogeneous MPSoCs, the management of shared memory resources is crucial in delivering end-to-end QoS. Previous frameworks have either focused on singular QoS targets or the allocation of partitionable resources among CPU applications at relatively slow timescales. However, heterogeneous MPSoCs typically require instant response from the memory system where most resources cannot be partitioned. Moreover, the health of different cores in a heterogeneous MPSoC is often measured by diverse performance objectives. In this work, we propose the Self-Aware Resource Allocation framework for heterogeneous MPSoCs. Priority-based adaptation allows cores to use different target performance and self-monitor their own intrinsic health. In response, the system allocates non-partitionable resources based on priorities. The proposed framework meets a diverse range of QoS demands from heterogeneous cores. Moreover, we present a runtime scheme to configure priority-based adaptation so that distinct sensitivities of heterogeneous QoS targets with respect to memory allocation can be accommodated. In addition, the priority of best-effort cores can also be regulated.
The Meniscus in Normal and Osteoarthritic Tissues: Facing the Structure Property Challenges and Current Treatment Trends
Authors: Murphy Caroline A. , Garg Atul K. , Silva-Correia Joana , Reis Rui L. , Oliveira Joaquim M. , Collins Maurice N.
Published: April 2019

The treatment of meniscus injuries has recently been facing a paradigm shift toward the field of tissue engineering, with the aim of regenerating damaged and diseased menisci as opposed to current treatment techniques. This review focuses on the structure and mechanics associated with the meniscus. The meniscus is defined in terms of its biological structure and composition. Biomechanics of the meniscus are discussed in detail, as an understanding of the mechanics is fundamental for the development of new meniscal treatment strategies. Key meniscal characteristics such as biological function, damage (tears), and disease are critically analyzed. The latest technologies behind meniscal repair and regeneration are assessed.
Transport of Topological Semimetals
Authors: Hu Jin , Xu Su-Yang , Ni Ni , Mao Zhiqiang
Published: April 2019

Three-dimensional (3D) topological semimetals represent a new class of topological matters. The study of this family of materials has been at the frontiers of condensed matter physics, and many breakthroughs have been made. Several topological semimetal phases, including Dirac semimetals (DSMs), Weyl semimetals (WSMs), nodal-line semimetals (NLSMs), and triple-point semimetals, have been theoretically predicted and experimentally demonstrated. The low-energy excitation around the Dirac/Weyl nodal points, nodal line, or triply degenerated nodal point can be viewed as emergent relativistic fermions. Experimental studies have shown that relativistic fermions can result in a rich variety of exotic transport properties, e.g., extremely large magnetoresistance, the chiral anomaly, and the intrinsic anomalous Hall effect. In this review, we first briefly introduce band structural characteristics of each topological semimetal phase, then review the current studies on quantum oscillations and exotic transport properties of various topological semimetals, and finally provide a perspective of this area.
Indoor PM2.5from coal combustion aggravates ovalbumin-induced asthma-like airway inflammation in BALB/c mice
Authors: Yu Jie , Li Kebin , Xu Jie
Published: April 2019

We hypothesized that indoor PM2.5exposure from coal combustion exaggerates airway inflammation in the lung tissue of asthmatic mice induced with ovalbumin (OVA). Forty BALB/c mice, randomly divided into four groups ( n = 10 per group), were intratracheally instilled with normal saline alone, PM2.5(2.5 mg/ml PM2.5alone), OVA (15 μg/ml OVA alone), and PM2.5+OVA (2.5 mg/ml PM2.5and 15 μg/ml OVA), respectively, four times at 2-wk intervals. Daily mean concentration of PM2.5from indoor coal combustion was 156.95 μg/m3. The highest metal composition in PM2.5was Zn (34.81 ± 1.8 μg/m3). Exposure to PM2.5+OVA significantly elevated IL-4 and decreased IFN-γ production in mice compared with the control ( P < 0.05). Exposure to PM2.5+OVA showed a significant increase in the protein levels of granulocyte-macrophage colony-stimulating factor and IL-8 and a decrease in the protein level of transforming growth factor-β1 in bronchoalveolar lavage fluid of mice compared with the control ( P < 0.05). The expression of IL-4 mRNA was significantly increased, whereas the expression of IFN-γ mRNA was decreased in lung tissue of the PM2.5+OVA group ( P < 0.05). The expression level of Foxp3 mRNA in the PM2.5+OVA group was significantly lower than that in the control group in lung tissue ( P < 0.05). Treatment with PM2.5+OVA promoted a prominent neutrophil sequestration into the lung parenchyma, goblet cell proliferation, and severe inflammatory cell infiltration in the airways. Exposure to PM2.5from indoor coal combustion might induce airway inflammatory immune responses and exacerbate peribronchiolar inflammation due to infiltration of inflammatory cells into the airway submucosa and airway structural pathological changes.
Changes in adipose tissue physiology during the first two weeks posthatch in chicks from lines selected for low or high body weight
Authors: Xiao Yang , Wang Guoqing , Gerrard Miranda E. , Wieland Sarah , Davis Mary , Cline Mark A. , Siegel Paul B. , Gilbert Elizabeth R.
Published: April 2019

Chickens from lines selected for low (LWS) or high (HWS) body weight (BW) differ in appetite and adiposity. Mechanisms associated with the predisposition to becoming obese are unclear. The objective of the experiment was to evaluate developmental changes in depot-specific adipose tissue during the first 2 wk posthatch. Subcutaneous (SQ), clavicular (CL), and abdominal (AB) depots were collected at hatch (DOH) and days 4 (D4) and 14 (D14) posthatch for histological and mRNA measurements. LWS chicks had decreased SQ fat mass on a BW basis with reduced adipocyte size from DOH to D4 and increased BW and fat mass with unchanged adipocyte size from D4 to D14. HWS chicks increased in BW from DOH to D14 and increased in fat mass in all three depots with enlarged adipocytes in the AB depot from D4 to D14. Meanwhile, CCAAT/enhancer-binding protein-α, neuropeptide Y, peroxisome proliferator-activated receptor-γ, and acyl-CoA dehydrogenase mRNAs differed among depots between lines at different ages. Plasma nonesterified fatty acids were greater in LWS than HWS at D4 and D14. From DOH to D4, LWS chicks mobilized SQ fat and replenished the reservoir through hyperplasia, whereas HWS chicks were dependent on hyperplasia and hypertrophy to maintain adipocyte size and depot mass. From D4 to D14, adipose tissue catabolism and adipogenesis slowed. Whereas LWS fat depots and adipocyte sizes remained stable, HWS chicks rapidly accumulated fat in CL and AB depots. Chicks predisposed to be anorexic or obese have different fat development patterns during the first 2 wk posthatch.
Skeletal muscle signaling responses to resistance exercise of the elbow extensors are not compromised by a preceding bout of aerobic exercise
Authors: Hansson Björn , Olsen Luke A. , Nicoll Justin X. , von Walden Ferdinand , Melin Michael , Strömberg Anna , Rullman Eric , Gustafsson Thomas , Fry Andrew C. , Fernandez-Gonzalo Rodrigo , Lundberg Tommy R.
Published: April 2019

The current study examined the effects of a preceding bout of aerobic exercise (AE) on subsequent molecular signaling to resistance exercise (RE) of the elbow extensors. Eleven men performed unilateral elbow-extensor AE (~45 min at 70% peak workload) followed by unilateral RE (4 × 7 maximal repetitions) for both arms. Thus, one arm performed AE+RE interspersed with 15 min recovery, whereas the other arm conducted RE alone. Muscle biopsies were taken from the triceps brachii of each arm immediately before (PRE) and 15 min (POST1) and 3 h (POST2) after RE. Molecular markers involved in translation initiation, protein breakdown, mechanosignaling, and ribosome biogenesis were analyzed. Peak power during RE was reduced by 24% (±19%) when preceded by AE ( P < 0.05). Increases in PGC1a and MuRF1 expression were greater from PRE to POST2 in AE+RE compared with RE (18- vs. 3.5- and 4- vs. 2-fold, respectively, interaction, P < 0.05). Myostatin mRNA decreased in both arms ( P < 0.05). Phosphorylation of AMPK (Thr172) increased (2.5-fold), and 4E-BP1 (Thr37/46) decreased (2.0-fold), after AE (interactions, P < 0.05). p70 S6K, yes-associated protein, and c-Jun NH2-terminal kinase phosphorylation were unaltered, whereas focal adhesion kinase decreased ~1.5-fold, and β1-integrin increased ~1.3- to 1.5-fold, (time effect, P < 0.05). Abundance of 45S pre-ribosomal (r)RNA (internally transcribed spacer, ITS) decreased (~30%) after AE (interaction, P < 0.05), whereas CMYC mRNA was greater in AE+RE compared with RE (12-fold, P < 0.05). POLR1B abundance increased after both AE+RE and RE. All together, our results suggest that a single bout of AE leads to an immediate decrease in signaling for translation initiation and ribosome biogenesis. Yet, this did not translate into altered RE-induced signaling during the 3-h postexercise recovery period.
Pure tones modulate the representation of orientation and direction in the primary visual cortex
Authors: McClure John P. , Polack Pierre-Olivier
Published: April 2019

Multimodal sensory integration facilitates the generation of a unified and coherent perception of the environment. It is now well established that unimodal sensory perceptions, such as vision, are improved in multisensory contexts. Whereas multimodal integration is primarily performed by dedicated multisensory brain regions such as the association cortices or the superior colliculus, recent studies have shown that multisensory interactions also occur in primary sensory cortices. In particular, sounds were shown to modulate the responses of neurons located in layers 2/3 (L2/3) of the mouse primary visual cortex (V1). Yet, the net effect of sound modulation at the V1 population level remained unclear. In the present study, we performed two-photon calcium imaging in awake mice to compare the representation of the orientation and the direction of drifting gratings by V1 L2/3 neurons in unimodal (visual only) or multimodal (audiovisual) conditions. We found that sound modulation depended on the tuning properties (orientation and direction selectivity) and response amplitudes of V1 L2/3 neurons. Sounds potentiated the responses of neurons that were highly tuned to the cue’s orientation and direction but weakly active in the unimodal context, following the principle of inverse effectiveness of multimodal integration. Moreover, sound suppressed the responses of neurons untuned for the orientation and/or the direction of the visual cue. Altogether, sound modulation improved the representation of the orientation and direction of the visual stimulus in V1 L2/3. Namely, visual stimuli presented with auditory stimuli recruited a neuronal population better tuned to the visual stimulus orientation and direction than when presented alone.

NEW & NOTEWORTHY The primary visual cortex (V1) receives direct inputs from the primary auditory cortex. Yet, the impact of sounds on visual processing in V1 remains controverted. We show that the modulation by pure tones of V1 visual responses depends on the orientation selectivity, direction selectivity, and response amplitudes of V1 neurons. Hence, audiovisual stimuli recruit a population of V1 neurons better tuned to the orientation and direction of the visual stimulus than unimodal visual stimuli.
Thalamocortical dysrhythmia in intraoperative recordings of focal epilepsy
Authors: Martire Daniel J. , Wong Simeon , Mikhail Mirriam , Ochi Ayako , Otsubo Hiroshi , Snead O. Carter , Donner Elizabeth , Ibrahim George M.
Published: April 2019

Resonant interactions between the thalamus and cortex subserve a critical role for maintenance of consciousness as well as cognitive functions. In states of abnormal thalamic inhibition, thalamocortical dysrhythmia (TCD) has been described. The characteristics of TCD include a slowing of resting oscillations, ectopic high-frequency activity, and increased cross-frequency coupling. Here, we demonstrate the presence of TCD in four patients who underwent resective epilepsy surgery with chronically implanted electrodes under anesthesia, continuously recording activity from brain regions at the periphery of the epileptogenic zone before and after resection. Following resection, we report an acceleration of the large-scale network resting frequency coincident with decreases in cross-frequency phase-amplitude coupling. Interregional functional connectivity in the surrounding cortex was also increased following resection of the epileptogenic focus. These findings provide evidence for the presence of TCD in focal epilepsy and highlight the importance of reciprocal thalamocortical oscillatory interactions in defining novel biomarkers for resective surgeries.

NEW & NOTEWORTHY Thalamocortical dysrhythmia (TCD) occurs in the context of thalamic dysfacilitation and is characterized by slowing of resting oscillations, ectopic high-frequency activity, and cross-frequency coupling. We provide evidence for TCD in focal epilepsy by studying electrophysiological changes occurring at the periphery of the resection margin. We report acceleration of resting activity coincident with decreased cross-frequency coupling and increased functional connectivity. The study of TCD in epilepsy has implications as a biomarker and therapeutic target.
Dry eye sensitizes cool cells to capsaicin-induced changes in activity via TRPV1
Authors: Hatta Azusa , Kurose Masayuki , Sullivan Cara , Okamoto Keiichiro , Fujii Noritaka , Yamamura Kensuke , Meng Ian D.
Published: April 2019

Corneal cool cells are sensitive to the ocular fluid status of the corneal surface and may be responsible for the regulation of basal tear production. Previously, we have shown that dry eye, induced by lacrimal gland excision (LGE) in rats, sensitized corneal cool cells to the transient receptor potential melastatin 8 (TRPM8) agonist menthol and to cool stimulation. In the present study, we examined the effect of dry eye on the sensitivity of cool cells to the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin. Single-unit recordings in the trigeminal ganglion were performed 7–10 days after LGE. At a concentration of 0.3 μM, capsaicin did not affect ongoing or cool-evoked activity in control animals yet facilitated ongoing activity and suppressed cool-evoked activity in LGE animals. At higher concentrations (3 μM), capsaicin continued to facilitate ongoing activity in LGE animals but suppressed ongoing activity in control animals. Higher concentrations of capsaicin also suppressed cool-evoked activity in both groups of animals, with an overall greater effect in LGE animals. In addition to altering cool-evoked activity, capsaicin enhanced the sensitivity of cool cells to heat in LGE animals. Capsaicin-induced changes were prevented by the application of the TRPV1 antagonist capsazepine. With the use of fluorescent in situ hybridization, TRPV1 and TRPM8 expression was examined in retrograde tracer-identified corneal neurons. The coexpression of TRPV1 and TRPM8 in corneal neurons was significantly greater in LGE-treated animals when compared with sham controls. These results indicate that LGE-induced dry eye increases TRPV1-mediated responses in corneal cool cells at least in part through the increased expression of TRPV1.

NEW & NOTEWORTHY Corneal cool cells are known to detect drying of the ocular surface. Our study is the first to report that dry eye induced alterations in cool cell response properties, including the increased responsiveness to noxious heat and activation by capsaicin. Along with the changes in cell response properties, it is possible these neurons also function differently in dry eye, relaying information related to the perception of ocular irritation in addition to regulating tearing and blinking.
The contradictory influence of velocity: representational momentum in the tactile modality
Authors: Merz Simon , Deller Julia , Meyerhoff Hauke S. , Spence Charles , Frings Christian
Published: April 2019

Representational momentum (RM) is the term used to describe a systematic mislocalization of dynamic stimuli, a forward shift; that is, an overestimation of the location of a stimulus along its anticipated trajectory. In the present study, we investigate the effect of velocity on tactile RM, because two distinct and contrasting predictions can be made, based on different theoretical accounts. According to classical accounts of RM, based on numerous visual and auditory RM studies, an increase of the forward shift with increasing target velocity is predicted. In contrast, theoretical accounts explaining spatiotemporal tactile illusions such as the tau or cutaneous rabbit effect predict a decrease of the forward shift with increasing target velocity. In three experiments reported here, a tactile experimental setup modeled on existing RM setups was implemented. Participants indicated the last location of a sequence of three tactile stimuli, which either did or did not imply motion in a consistent direction toward the elbow/wrist. Velocity was manipulated by changing the interstimulus interval as well as the duration of the stimuli. The results reveal that increasing target velocity led to a decrease and even a reversal of the forward shift, resulting in a backward shift. This result is consistent with predictions based on the evidence from tactile spatiotemporal illusions. The theoretical implications of these results for RM are discussed.

NEW & NOTEWORTHY This study tests two distinct predictions concerning the influence of velocity on the localization of dynamic tactile stimuli. We demonstrate for tactile stimuli that with increasing velocity, a misperception in the direction of anticipated motion (termed “representational momentum”) turns into a misperception against the direction of motion. This result is in line with predictions based on tactile spatiotemporal illusions but challenges classical theoretical accounts of representational momentum based on evidence from vision and audition.
Case Studies in Neuroscience: The central and somatosensory contributions to finger interdependence and coordination: lessons from a study of a “deafferented person”
Authors: Cuadra Cristian , Falaki Ali , Sainburg Robert , Sarlegna Fabrice R. , Latash Mark L.
Published: April 2019

We tested finger force interdependence and multifinger force-stabilizing synergies in a patient with large-fiber peripheral neuropathy (“deafferented person”). The subject performed a range of tasks involving accurate force production with one finger and with four fingers. In one-finger tasks, nontask fingers showed unintentional force production (enslaving) with an atypical pattern: very large indices for the lateral (index and little) fingers and relatively small indices for the central (middle and ring) fingers. Indices of multifinger synergies stabilizing total force and of anticipatory synergy adjustments in preparation to quick force pulses were similar to those in age-matched control females. During constant force production, removing visual feedback led to a slow force drift to lower values (by ~25% over 15 s). The results support the idea of a neural origin of enslaving and suggest that the patterns observed in the deafferented person were reorganized based on everyday manipulation tasks. The lack of significant changes in the synergy index shows that synergic control can be organized in the absence of somatosensory feedback. We discuss the control of the hand in deafferented persons within the α-model of the equilibrium-point hypothesis and suggest that force drift results from an unintentional drift of the control variables to muscles toward zero values.

NEW & NOTEWORTHY We demonstrate atypical patterns of finger enslaving and unchanged force-stabilizing synergies in a person with large-fiber peripheral neuropathy. The results speak strongly in favor of central origin of enslaving and its reorganization based on everyday manipulation tasks. The data show that synergic control can be implemented in the absence of somatosensory feedback. We discuss the control of the hand in deafferented persons within the α-model of the equilibrium-point hypothesis.
Somatosensory interactions reveal feature-dependent computations
Authors: Rahman M. Shoaibur , Yau Jeffrey M.
Published: April 2019

Our ability to perceive and discriminate textures is based on the processing of high-frequency vibrations generated on the fingertip as it scans across a surface. Although much is known about the processing of vibration amplitude and frequency information when cutaneous stimulation is experienced at a single location on the body, how these stimulus features are processed when touch occurs at multiple locations is poorly understood. We evaluated participants’ ability to discriminate tactile cues (100–300 Hz) on one hand while they ignored distractor cues experienced on their other hand. We manipulated the relative positions of the hands to characterize how limb position influenced cutaneous touch interactions. In separate experiments, participants judged either the frequency or intensity of mechanical vibrations. We found that vibrations experienced on one hand always systematically modulated the perception of vibrations on the other hand. Notably, bimanual interaction patterns and their sensitivity to hand locations differed according to stimulus feature. Somatosensory interactions in intensity perception were only marked by attenuation that was invariant to hand position manipulations. In contrast, interactions in frequency perception consisted of both bias and sensitivity changes that were more pronounced when the hands were held in close proximity. We implemented models to infer the neural computations that mediate somatosensory interactions in the intensity and frequency dimensions. Our findings reveal obligatory and feature-dependent somatosensory interactions that may be supported by both feature-specific and feature-general operations.

NEW & NOTEWORTHY Little is known about the neural computations mediating feature-specific sensory interactions between the hands. We show that vibrations experienced on one hand systematically modulate the perception of vibrations felt on the other hand. Critically, interaction patterns and their dependence on the relative positions of the hands differed depending on whether participants judged vibration intensity or frequency. These results, which we recapitulate with models, imply that somatosensory interactions are mediated by feature-dependent neural computations.
The effects of vibration-induced altered stretch reflex sensitivity on maximal motor unit firing properties
Authors: Barrera-Curiel Alejandra , Colquhoun Ryan J. , Hernandez-Sarabia Jesus A. , DeFreitas Jason M.
Published: April 2019

It is well known that muscle spindles have a monosynaptic, excitatory connection with α-motoneurons. However, the influence of muscle spindles on human motor unit behavior during maximal efforts remains untested. It has also been shown that muscle spindle function, as assessed by peripheral reflexes, can be systematically manipulated with muscle vibration. Therefore, the purpose of this study was to analyze the effects of brief and prolonged vibration on maximal motor unit firing properties. A crossover design was used, in which each of the 24 participants performed one to three maximal knee extensions under three separate conditions: 1) control, 2) brief vibration that was applied during the contraction, and 3) after prolonged vibration that was applied for ~20 min before the contraction. Multichannel EMG was recorded from the vastus lateralis during each contraction and was decomposed into its constituent motor unit action potential trains. Surprisingly, an approximate 9% reduction in maximal voluntary strength was observed not only after prolonged vibration but also during brief vibration. In addition, both vibration conditions had a large, significant effect on firing rates (a decrease in the rates) and a small to moderate, nonsignificant effect on recruitment thresholds (a small increase in the thresholds). Therefore, vibration had a detrimental influence on both maximal voluntary strength and motor unit firing properties, which we propose is due to altered function of the stretch reflex pathway.

NEW & NOTEWORTHY We used vibration to alter muscle spindle function and examined the vibration’s influence on maximal motor unit properties. We discovered that vibration had a detrimental influence on motor unit behavior and motor output by decreasing motor unit firing rates, increasing recruitment thresholds, which led to decreased maximal strength. We believe that understanding the role of muscle spindles during maximal contractions provides a deeper insight into motor control and sensorimotor integration.
Stable memory and computation in randomly rewiring neural networks
Authors: Acker Daniel , Paradis Suzanne , Miller Paul
Published: April 2019

Our brains must maintain a representation of the world over a period of time much longer than the typical lifetime of the biological components producing that representation. For example, recent research suggests that dendritic spines in the adult mouse hippocampus are transient with an average lifetime of ~10 days. If this is true, and if turnover is equally likely for all spines, ~95% of excitatory synapses onto a particular neuron will turn over within 30 days; however, a neuron’s receptive field can be relatively stable over this period. Here, we use computational modeling to ask how memories can persist in neural circuits such as the hippocampus and visual cortex in the face of synapse turnover. We demonstrate that Hebbian plasticity during replay of presynaptic activity patterns can integrate newly formed synapses into pre-existing memories. Furthermore, we find that Hebbian plasticity during replay is sufficient to stabilize the receptive fields of hippocampal place cells in a model of the grid-cell-to-place-cell transformation in CA1 and of orientation-selective cells in a model of the center-surround-to-simple-cell transformation in V1. Together, these data suggest that a simple plasticity rule, correlative Hebbian plasticity of synaptic strengths, is sufficient to preserve neural representations in the face of synapse turnover, even in the absence of activity-dependent structural plasticity.

NEW & NOTEWORTHY Recent research suggests that synapses turn over rapidly in some brain structures; however, memories seem to persist for much longer. We show that Hebbian plasticity of synaptic strengths during reactivation events can preserve memory in computational models of hippocampal and cortical networks despite turnover of all synapses. Our results suggest that memory can be stored in the correlation structure of a network undergoing rapid synaptic remodeling.
Autonomous patch-clamp robot for functional characterization of neurons in vivo: development and application to mouse visual cortex
Authors: Holst Gregory L. , Stoy William , Yang Bo , Kolb Ilya , Kodandaramaiah Suhasa B. , Li Lu , Knoblich Ulf , Zeng Hongkui , Haider Bilal , Boyden Edward S. , Forest Craig R.
Published: April 2019

Patch clamping is the gold standard measurement technique for cell-type characterization in vivo, but it has low throughput, is difficult to scale, and requires highly skilled operation. We developed an autonomous robot that can acquire multiple consecutive patch-clamp recordings in vivo. In practice, 40 pipettes loaded into a carousel are sequentially filled and inserted into the brain, localized to a cell, used for patch clamping, and disposed. Automated visual stimulation and electrophysiology software enables functional cell-type classification of whole cell-patched cells, as we show for 37 cells in the anesthetized mouse in visual cortex (V1) layer 5. We achieved 9% yield, with 5.3 min per attempt over hundreds of trials. The highly variable and low-yield nature of in vivo patch-clamp recordings will benefit from such a standardized, automated, quantitative approach, allowing development of optimal algorithms and enabling scaling required for large-scale studies and integration with complementary techniques.

NEW & NOTEWORTHY In vivo patch-clamp is the gold standard for intracellular recordings, but it is a very manual and highly skilled technique. The robot in this work demonstrates the most automated in vivo patch-clamp experiment to date, by enabling production of multiple, serial intracellular recordings without human intervention. The robot automates pipette filling, wire threading, pipette positioning, neuron hunting, break-in, delivering sensory stimulus, and recording quality control, enabling in vivo cell-type characterization.
Angular vestibuloocular reflex responses in Otop1 mice. I. Otolith sensor input is essential for gravity context-specific adaptation
Authors: Khan Serajul I. , Della Santina Charles C. , Migliaccio Americo A.
Published: April 2019

The role of the otoliths in mammals in the angular vestibuloocular reflex (VOR) has been difficult to determine because there is no surgical technique that can reliably ablate them without damaging the semicircular canals. The Otopetrin1 (Otop1) mouse lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. By using these animals we sought to determine the role of the otoliths in angular VOR baseline function and adaptation. In six Otop1 mice and six control littermates we measured baseline ocular countertilt about the three primary axes in head coordinates; baseline horizontal (rotation about an Earth-vertical axis parallel to the dorsal-ventral axis) and vertical (rotation about an Earth-vertical axis parallel to the interaural axis) sinusoidal (0.2–10 Hz, 20–100°/s) VOR gain (= eye/head velocity); and the horizontal and vertical VOR after gain-increase (1.5×) and gain-decrease (0.5×) adaptation training. Countertilt responses were significantly reduced in Otop1 mice. Baseline horizontal and vertical VOR gains were similar between mouse types, and so was horizontal VOR adaptation. For control mice, vertical VOR adaptation was evident when the testing context, left ear down (LED) or right ear down (RED), was the same as the training context (LED or RED). For Otop1 mice, VOR adaptation was evident regardless of context. Our results suggest that the otolith translational signal does not contribute to the baseline angular VOR, probably because the mouse VOR is highly compensatory, and does not alter the magnitude of adaptation. However, we show that the otoliths are important for gravity context-specific angular VOR adaptation.

NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) in adaptation of the angular vestibuloocular reflex (VOR) in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. We show that they do not contribute to adaptation of the normal angular VOR. However, the otoliths provide the main cue for gravity context-specific VOR adaptation.
Angular vestibuloocular reflex responses in Otop1 mice. II. Otolith sensor input improves compensation after unilateral labyrinthectomy
Authors: Khan Serajul I. , Della Santina Charles C. , Migliaccio Americo A.
Published: April 2019

The role of the otoliths in mammals in the normal angular vestibuloocular reflex (VOR) was characterized in an accompanying study based on the Otopetrin1 (Otop1) mouse, which lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. That study showed that otoliths do not contribute to the normal horizontal (rotation about Earth-vertical axis parallel to dorso-ventral axis) and vertical (rotation about Earth-vertical axis parallel to interaural axis) angular VOR but do affect gravity context-specific VOR adaptation. By using these animals, we sought to determine whether the otoliths play a role in the angular VOR after unilateral labyrinthectomy when the total canal signal is reduced. In five Otop1 mice and five control littermates we measured horizontal and vertical left-ear-down and right-ear-down sinusoidal VOR (0.2–10 Hz, 20–100°/s) during the early (3–5 days) and plateau (28–32 days) phases of compensation after unilateral labyrinthectomy and compared these measurements with baseline preoperative responses from the accompanying study. From similar baselines, acute gain loss was ~25% less in control mice, and chronic gain recovery was ~40% more in control mice. The acute data suggest that the otoliths contribute to the angular VOR when there is a loss of canal function. The chronic data suggest that a unilateral otolith signal can significantly improve angular VOR compensation. These data have implications for vestibular rehabilitation of patients with both canal and otolith loss and the development of vestibular implants, which currently only mimic the canals on one side.

NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) on the acute and chronic angular vestibuloocular reflex (VOR) after unilateral labyrinthectomy in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. This study shows that the otolith signal is used to augment the acute angular VOR and help boost VOR compensation after peripheral injury.
A decade of magnetic vestibular stimulation: from serendipity to physics to the clinic
Authors: Ward Bryan K. , Roberts Dale C. , Otero-Millan Jorge , Zee David S.
Published: April 2019

For many years, people working near strong static magnetic fields of magnetic resonance imaging (MRI) machines have reported dizziness and sensations of vertigo. The discovery a decade ago that a sustained nystagmus can be observed in all humans with an intact labyrinth inside MRI machines led to a possible mechanism: a Lorentz force occurring in the labyrinth from the interactions of normal inner ear ionic currents and the strong static magnetic fields of the MRI machine. Inside an MRI, the Lorentz force acts to induce a constant deflection of the semicircular canal cupula of the superior and lateral semicircular canals. This inner ear stimulation creates a sensation of rotation, and a constant horizontal/torsional nystagmus that can only be observed when visual fixation is removed. Over time, the brain adapts to both the perception of rotation and the nystagmus, with the perception usually diminishing over a few minutes, and the nystagmus persisting at a reduced level for hours. This observation has led to discoveries about how the central vestibular mechanisms adapt to a constant vestibular asymmetry and is a useful model of set-point adaptation or how homeostasis is maintained in response to changes in the internal milieu or the external environment. We review what is known about the effects of stimulation of the vestibular system with high-strength magnetic fields and how the understanding of the mechanism has been refined since it was first proposed. We suggest future ways that magnetic vestibular stimulation might be used to understand vestibular disease and how it might be treated.
Sex, Oxidative Stress, and Hypertension: Insights From Animal Models
Authors: Reckelhoff Jane F. , Romero Damian G. , Yanes Cardozo Licy L.
Published: April 2019

One of the mechanisms responsible for blood pressure (BP) regulation is thought to be oxidative stress. In this review, we highlight preclinical studies that strongly support a role for oxidative stress in development and maintenance of hypertension in male animals, based on depressor responses to antioxidants, particularly tempol and apocynin. In females, oxidative stress seems to be important in the initial development of hypertension. However, whether maintenance of hypertension in females is mediated by oxidative stress is not clear. In clinical studies, pharmacological intervention to reduce BP with antioxidants has conflicting results, mostly negative. This review will discuss the uncertainties regarding blood pressure control and oxidative stress and potential reasons for these outcomes.
Magnitude of Neonatal Jaundice and Its Associated Factor in Neonatal Intensive Care Units of Mekelle City Public Hospitals, Northern Ethiopia
Authors: Lake Eyasu A. , Abera Gerezgiher B. , Azeze Gedion A. , Gebeyew Natnaeal A. , Demissie Birhanu W.
Published: April 2019

Background. Jaundice in the neonate is one of the most common clinical problems. Globally, every year about 1.1 million babies develop it and the vast majority reside in sub-Saharan Africa and South Asia. Study on magnitude and local factors associated with neonatal jaundice is limited in Ethiopia. So this study was aimed at assessing magnitude and predictors of neonatal jaundice among neonates admitted to neonatal intensive care unit of public hospitals in Mekelle city, Northern Ethiopia. Methods. Institution based cross-sectional study was conducted from February to April 2016 in neonatal intensive care unit of Mekelle city public hospitals. Systematic random sampling technique was used to select study participants. Data was collected by interviewing mothers through structured questionnaire and reviewing neonates’ medical records using checklist. Multivariable binary logistic regression analyses were employed to identify factors associated with neonatal jaundice. Results. A total of 209 neonates with their mothers were included. The proportion of neonatal jaundice was found to be 37.3%. Prolonged labor [AOR = 4.39; 95% CI (1.8-10.69)], being male [AOR = 3.7; 95% CI (1.54-8.87)], maternal “O” blood group [AOR = 5.05; 95% CI (1.53-16.72)], sepsis [AOR = 2.64; 95% CI (1.15-6.05)], and blood type incompatibility [AOR = 18.21; 95% CI (6.36-52.13)] were positively associated with neonatal jaundice while night time delivery [AOR 0.42; 95% CI (0.18-0.96)] showed negative association. Conclusion. The magnitude of neonatal jaundice among neonates was found to be high. Duration of labor, time of delivery, sexes of neonate, sepsis, maternal blood group, and blood type incompatibility were significantly associated with neonatal jaundice. Therefore, improving newborn care and timely intervention for neonates with ABO/Rh incompatibility are recommended.
Progressive Scoliosis in a Child with Cystic Fibrosis
Authors: Castner Lauren M. , Nasr Samya Z. , Arteta Manuel
Published: April 2019

We discuss an adolescent female with cystic fibrosis, asthma, and scoliosis who had a rapid decline in her pulmonary function despite typical treatment for a cystic fibrosis exacerbation. Ultimately, she had a fixed airway obstruction likely due to her progressive scoliosis, which improved following surgical intervention.
Vancomycin-Induced Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome Masquerading as Elusive Sepsis
Authors: Roy Sumon , Goswamy Vinay P. , Barssoum Kirolos N. , Rai Devesh
Published: April 2019

We present a unique case of vancomycin-induced drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome masquerading as elusive endocarditis. A 37-year-old female actively using intravenous drugs presented with worsening right upper extremity pain, fever, and chills. Workup revealed methicillin-resistant staphylococcus aureus (MRSA) bacteremia and multiple right-sided septic pulmonary emboli. Echocardiogram was negative for vegetation. Vancomycin was initiated for bacteremia management suspected secondary to right upper extremity abscesses. However, despite resolution of abscesses, fevers persisted, raising suspicion for endocarditis not detected by echocardiogram. On hospital day 25, the patient began showing signs of DRESS syndrome, ultimately manifesting as transaminitis, eosinophilia, and a diffuse, maculopapular rash. Vancomycin was switched to Linezolid and she improved on high dose steroids. The persistent fevers throughout this hospital course were thought to be an elusive endocarditis before DRESS syndrome fully manifested. Although Vancomycin-induced DRESS is uncommon, this case highlights the importance of identifying early signs of significant adverse effects.
HSV-Encephalitis Reactivation after Cervical Spine Surgery
Authors: Heller Joshua E. , Stricsek Geoffrey , Thaete Lauren
Published: April 2019

Background. Herpes simplex virus encephalitis (HSVE) is a viral neurological disorder that occurs when the herpes simplex virus (HSV) enters the brain. The disorder is characterized by the inflammation of the brain and a significant decline in mental status. HSVE reactivation after neurosurgery, although rare, can cause severe neurological deterioration. The high morbidity rate among untreated patients necessitates prompt diagnosis and management. Case Description. We report a case of a 78-year-old woman with no known prior history of HSVE and declining mental status eleven days after a posterior C3-T1 decompression and instrumented fusion following resection of an intradural extramedullary tumor, confirmed to be meningioma on final pathology. Reactivation of HSV-1 encephalitis was suspected to be the underlying cause of her symptoms, though MRI scans of the brain for HSVE were negative. The patient reacted positively to a 21-day treatment of acyclovir and was discharged with a neurological status comparable to her preoperative baseline. This case contributes to the literature in that it is the first reported instance of HSVE reactivation after intradural cervical spinal surgery with negative MRI findings. Conclusion. We recommend utilizing multiple tests, including PCR, EEG, and MRI, for postoperative neurosurgery patients that have decreased mental status in order to quickly and correctly diagnose/treat patients who are HSVE positive. Clinicians should consider the possibility of receiving false-negative results from PCR, CSF, EEG, or MRI tests before terminating treatment for HSVE reactivation.