bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Uncertainty-Seeking Behavior Mediated by Cholinergic Influence on Dopamine
Authors: Belkaid Marwen , Krichmar Jeffrey L. 
Published: July 2019

AbstractRecent findings suggest that acetylcholine mediates uncertainty-seeking behaviors through its projection to dopamine neurons – another neuromodulatory system known for its major implication in reinforcement learning and decision-making. In this paper, we propose a leaky-integrate-and-fire model of this mechanism. It implements a softmax-like selection with an uncertainty bonus by a cholinergic drive to dopaminergic neurons, which in turn influence synaptic currents of downstream neurons. The model is able to reproduce experimental data in two decision-making tasks. It also predicts that i) in the absence of cholinergic input, dopaminergic activity would not correlate with uncertainty, and that ii) the adaptive advantage brought by the implemented uncertainty-seeking mechanism is most useful when sources of reward are not highly uncertain. Moreover, this modeling work allows us to propose novel experiments which might shed new light on the role of acetylcholine in both random and directed exploration. Overall, this study thus contributes to a more comprehensive understanding of the roles of the cholinergic system and its involvement in decision-making in particular.
Contributions of spatial and temporal control of step length symmetry in the transfer of locomotor adaptation from a motorized to a non-motorized split-belt treadmill
Authors: Gregory Daniel L. , Sup Frank C. , Choi Julia T. 
Published: July 2019

AbstractBackgroundLocomotor adaptation during motorized split-belt walking depends on independent processes for spatial and temporal control of step length symmetry. The unique mechanics of motorized split-belt walking that constrains two limbs to move at different speeds during double support may limit transfer of step length adaptations to new walking contexts.Research questionHow do spatial and temporal locomotor outputs contribute to transfer of step length adaptation from constrained motorized split-belt walking to unconstrained non-motorized split-belt walking?MethodsWe built a non-motorized split-belt treadmill that allows the user to walk at their own pace while simultaneously allowing the two belts to be self-propelled at different speeds. 10 healthy young participants walked on the non-motorized split-belt treadmill after an initial 10-minute adaptation on the motorized split-belt with a 2:1 speed ratio. Foot placement relative to the body and timing between heel strikes were calculated to determine spatial and temporal motor outputs, respectively. Separate repeated measures ANOVAs were used for step length difference and its spatial and temporal components to assess for transfer to the non-motorized treadmill.ResultsWe found robust after-effects in step length difference during transfer to non-motorized split-belt treadmill walking that were primarily driven by changes in temporal motor outputs. Conversely, residual after-effects observed during motorized tied-belt treadmill walking (post-transfer) were driven by changes in spatial motor outputs.SignificanceOur data showed decoupling of adapted spatial and temporal locomotor outputs during the transfer to non-motorized split-belt walking, raising the new possibility of using a non-motorized split-belt treadmill to target specific spatial or temporal gait deficits.
Field relevant variation in ambient temperature modifies the density-dependent establishment of Plasmodium falciparum in mosquitoes: implications for the infectious reservoir and beyond?
Authors: Pathak Ashutosh K. , Shiau Justine C. , Thomas Matthew B. , Murdock Courtney 
Published: July 2019

AbstractThe relationship between Plasmodium falciparum gametocyte density and infections in mosquitoes is central to understanding the rates of transmission with important implications for control. Here, we determined whether field relevant variation in environmental temperature could also modulate this relationship. Anopheles stephensi were challenged with three densities of P. falciparum gametocytes spanning a ∼10-fold gradient, and housed under diurnal/daily temperature range (“DTR”) of 9°C around means of 20°C, 24°C and 28°C. At the peak stages of infection for each temperature, the proportion of mosquitoes infected with oocysts in the midguts or infectious with sporozoites in the salivary glands were measured (referred to collectively as vector competence hereon), in addition to oocyst intensities from infected midguts. While vector competence was similar at 20 DTR 9°C and 24 DTR 9°C, the proportion of mosquitoes infected and subsequently infectious were also comparable, with evidence, surprisingly, for higher vector competence in mosquitoes challenged with intermediate gametocyte densities. For the same gametocyte densities however, severe reduction in the proportion of infectious mosquitoes was accompanied by a significant decline in vector competence at 28 DTR 9°C, although density per se showed a positive and linear effect at this temperature. Unlike vector competence, oocyst intensities decreased with increasing temperatures with a predominantly positive and linear association with gametocyte density, especially at 28 DTR 9°C. Oocyst intensities across individual infected midguts suggested temperature-specific differences in mosquito susceptibility/resistance: at 20 DTR 9°C and 24 DTR 9°C, dispersion (aggregation) increased in a density-dependent manner but not at 28 DTR 9°C where the distributions were consistently random. Limitations notwithstanding, our results have manifold implications in, for instance, how variation in temperature could modify seasonal dynamics of infectious reservoirs and transmission and the contribution of high-/patent- and low-density/sub-patent carriers, to suggestions for design and deployment of transmission-blocking vaccines/drugs, but with a cautionary note suggesting how low efficacy could lead to transmission enhancement in certain environments.
The Tuberous Sclerosis gene, Tsc1, represses parvalbumin+/fast-spiking properties in somatostatin-lineage cortical interneurons
Authors: Malik Ruchi , Pai Emily Ling-Lin , Rubin Anna N , Stafford April M , Angara Kartik , Minasi Petros , Rubenstein John L , Sohal Vikaas S , Vogt Daniel 
Published: July 2019

AbstractMedial ganglionic eminence (MGE)-derived somatostatin (SST)+ and parvalbumin (PV)+ cortical interneurons (CINs), have characteristic molecular, anatomical and physiological properties. However, mechanisms regulating their diversity remain poorly understood. Here, we show that conditional loss of the Tuberous Sclerosis (TS) gene, Tsc1, which inhibits mammalian target of rapamycin (MTOR), causes a subset of SST+ CINs, to express PV and adopt fast-spiking (FS) properties, characteristic of PV+ CINs. These changes also occur when only one allele of Tsc1 is deleted, making these findings relevant to individuals with TS. Notably, treatment with rapamycin, which inhibits MTOR, reverses these changes in adult mice. These data reveal novel functions of MTOR signaling in regulating PV expression and FS properties, which may contribute to some neuropsychiatric symptoms observed in TS. Moreover, they suggest that CINs can exhibit properties intermediate between those classically associated with PV+ or SST+ CINs, which may be dynamically regulated by the MTOR signaling.
In vitro reconstitution of branched microtubule nucleation
Authors: Tariq Ammarah , Green Lucy , Jeynes J Charles G. , Soeller Christian , Wakefield James G. 
Published: July 2019

AbstractEukaryotic cell division requires the mitotic spindle, a microtubule (MT)-based structure which accurately aligns and segregates duplicated chromosomes. The dynamics of spindle formation are determined primarily by correctly localising the MT nucleator, γ-Tubulin Ring Complex (γ-TuRC)1-4, within the cell. A conserved MT-associated protein complex, Augmin, recruits γ-TuRC to pre-existing spindle MTs, amplifying their number, in an essential cellular phenomenon termed “branched” MT nucleation5-9. Here, we purify endogenous, GFP-tagged Augmin and γ-TuRC from Drosophila embryos to near homogeneity using a novel one-step affinity technique. We demonstrate that, in vitro, while Augmin alone does not affect Tubulin polymerisation dynamics, it stimulates γ-TuRC-dependent MT nucleation in a cell cycle-dependent manner. We also assemble and visualise the MT-Augmin-γ-TuRC-MT junction using light microscopy. Our work therefore conclusively reconstitutes branched MT nucleation. It also provides a powerful synthetic approach with which to investigate the emergence of cellular phenomena, such as mitotic spindle formation, from component parts.
Blue sky’s the limit? Somatic embryogenesis as a means of propagating recalcitrant blue spruce (Picea pungens) cultivar Hoopsii
Authors: Demone Jordan , Mao Jingqin , Wan Shen , Nourimand Maryam , Hansen Äsbjörn Erik , Flinn Barry , Facchin Olivia , Prost Alar , Altosaar Illimar 
Published: July 2019

AbstractThe ‘triple-blue’ cultivar of blue spruce (Picea pungens Hoopsii) is notably recalcitrant towards the realm of traditional vegetative propagation methods. Its ability to naturally proliferate is limited by ovule and embryo abortion during the growing season, leading to low viable seed yield. In this study, we established a protocol using somatic embryogenesis (SE) as a means of propagating this popular ornamental cultivar. We collected cones from Hoopsii trees at seven different timepoints throughout the growing season (mid-June to late July in Ottawa (Plant Hardiness Zone 5A)). Female megagametophytes were harvested following each collection and immature zygotic embryos were plated onto induction media. Early somatic embryos began developing from the embryonic tissue (ET) three to five weeks following induction. The highest ET initiation frequency occurred from embryos collected June 20–July 10, suggesting that developmental stage of the embryo was a significant factor in SE induction. The conversion of mature somatic embryos into plantlets (emblings) was completed in eight–ten weeks at a rate of 92.8%. In this study, we demonstrate that in vitro somatic embryogenesis using our optimized protocol is a fast and prolific method for the mass propagation of Hoopsii blue spruce. This is the first report on the production of somatic Hoopsii emblings.
Changes in endolysosomal organization define a pre-degenerative state in thecrumbsmutantDrosophilaretina
Authors: Kraut Rachel S. , Knust Elisabeth 
Published: July 2019

AbstractMutations in the epithelial polarity genecrumbs(crb) lead to retinal degeneration inDrosophilaand in humans. The overall morphology of the retina and its deterioration inDrosophila crbmutants has been well-characterized, but the cell biological origin of the degeneration is not well understood. Degenerative conditions in the retina and elsewhere in the nervous system often involve defects in degradative intracellular trafficking pathways. So far, however, effects ofcrbon the endolysosomal system, or on the spatial organization of these compartments in photoreceptor cells have not been described. We therefore asked whether photoreceptors incrbmutants exhibit alterations in endolysosomal compartments under pre-degenerative conditions, where the retina is still morphologically intact. Data presented here show that, already well before the onset of degeneration, Arl8, Rab7, and Atg8-carrying endolysosomal and autophagosomal compartments undergo changes in morphology and positioning with respect to each other incrbmutant retinas. We propose that these changes may be early signs of the degeneration-prone condition incrbretinas.
Prenatal heat stress effects on gestation and postnatal behavior in kid goats
Authors: Coloma-García Wellington , Mehaba Nabil , Llonch Pol , Caja Gerardo , Such Xavier , Salama Ahmed A. K. 
Published: July 2019

AbstractConsequences of heat stress during pregnancy can affect the normal development of the offspring. In the present experiment, 30 Murciano-Granadina dairy goats (41.8 ± 5.7 kg) were exposed to 2 thermal environments varying in temperature-humidity index (THI) from 12 days before mating to 45 days of gestation. The environmental conditions were: gestation thermal-neutral (GTN; THI = 71 ± 3); and gestation heat stress (GHS; THI = 85 ± 3). At 27 ± 4 days old, GTN-born female kids (n = 16) and GHS-born ones (n = 10) were subjected to 2 tests: arena test (AT) and novel object test (NOT), the latter was repeated at 3 months of age. Additionally, 8 months after birth, a subset of growing goats (n = 8) coming from GTN and GHS (16.8 ± 3.4 kg BW) were exposed consecutively to 2 environmental conditions: a basal thermal-neutral period (THI = 72 ± 3) for 7 days, and a heat-stress period (THI = 87 ± 2) for 21 days. In both periods, feeding behavior, resting behavior, other active behaviors (exploring, grooming), thermally-associated behaviors and posture were recorded. The gestation length was shortened by 3 days in GHS goats. In the AT, GHS kids showed a lower number of sniffs (P < 0.01) compared to GTN. In the NOT, GHS kids also tended to show a lower number of sniffs (P = 0.09). During heat exposure, GTN and GHS growing goats spent more time resting as well as exhibited more heat-stress related behaviors such as panting and drinking (P < 0.001); however, no differences were observed between both groups. In conclusion, heat stress during the first third of pregnancy shortened gestation length and influenced the exploratory behavior of the kids in the early life without impact on the behavior during the adulthood when exposed to heat stress.
Employee involvement in decision-making: the more the better?
Authors: Tian Xiaowen , Zhai Xiaoxuan 
Published: July 2019

PurposeThe purpose of this paper is to relate participative decision-making (PDM) to organizational learning, and examine the impact of PDM on organizational performance.Design/methodology/approachThe paper integrates the resource-based theory with organizational learning theory to develop a framework, and distinguishes PDM in which decisions are jointly made by employees and managers from employee decision-making (EDM) in which decisions are completely in the hands of employees. The paper incorporates an augmented Cobb–Douglass production function into a structural equation model to estimate the performance impact of PDM and EDM.FindingsThe paper tests the framework against firm-level data form China, and finds that PDM provides an opportunity for collective learning, and has a positive relationship with productivity-based profit gains; the positive relationship is stronger in firms whose management has greater accumulated knowledge and experience; EDM fails to provide an opportunity for collective learning, and has a negative relationship with productivity-based profit gains.Originality/valuePrior research focused on the role of PDM in enhancing the motivation and performance of individual employees, considered the degree of employee involvement as a continuum with the highest being decision-making “completely in the hands of employees,” and concluded that the more involved are employees in decision-making the better. This paper relates PDM to organizational performance, and challenges this conventional view from an organizational learning perspective.
The joint effects of IT resources and CEO support in IT assimilation
Authors: Gao Peiran , Gong Yeming , Zhang Jinlong , Mao Hongyi , Liu Shan 
Published: July 2019

PurposeThe purpose of this paper is to explore the joint effects of different types of IT resources and top management support. Especially, the authors attempt to mainly examine a negative synergy or substitution relationship between IT infrastructure resources and CEO support, and a positive synergy or complementary relationship between IT human resources and CEO support among the large-sized enterprises.Design/methodology/approachA research model that integrates IT infrastructure resources, IT human resources, CEO support and the degree of usage of IT for business objectives (i.e. IT business spanning capability) is developed. Based on a sample of 112 large-sized enterprises, partial least squares is used to analyze the research model.FindingsWhereas the positive moderating role of CEO support in the effectiveness of IT human resources is insignificant, CEO support and IT infrastructure resources have a substitution relationship in predicting IT business spanning capability. Furthermore, the results can explain under which conditions IT infrastructure resources insignificantly or significantly affect IT business spanning capability in large-sized enterprises. Specially, IT infrastructure resources significantly affect IT business spanning capability only when CEO support is low. Thus, in the presence of high CEO support, IT executives in large-sized enterprises should prioritize developing highly effective IT resources, such as IT human resources.Originality/valueThis paper highlights the joint effects of two critical IT resource types (i.e. IT infrastructure and IT human resources) and CEO support in the IT assimilation process among the large-sized enterprises, ultimately contributing to information systems theories and practices.
Leveraging previously reported research to create a decision support tool for institutional facility maintenance
Authors: Beauregard Michael A. , Ayer Steven K. 
Published: July 2019

PurposeThe discretionary expense budget required to maintain public infrastructure has declined in recent years, even as public expectations and accountability for performance have increased. The purpose of this paper is to leverage previously reported research to create a decision support tool (DST) for prioritizing institutional facility maintenance.Design/methodology/approachA structured literature review was developed to identify critical aspects of facility maintenance shown to have a positive relationship with academic performance in K-12 schools within the USA. Analytical hierarchy process (AHP) serves as a framework for a multi-criteria DST based on the findings of the literature review. Finally, a targeted focus group of industry professionals was used to validate the usability of the resulting DST.FindingsThe framework for the DST developed for this study effectively represents the scale and scope of an institutional facility. Results of the study suggest that when evaluating multi-criteria work orders, the proposed visual AHP methodology can be used to generate usable DSTs to assist with the prioritization of work.Practical implicationsThis study provides a methodology for building a multi-criterion DST leveraging precedent research, using a visual AHP to assist facility management (FM) decision-makers in the prioritization of routine work orders.Originality/valueThe developed process indicates a practical approach to incorporating disparate research findings into a concise and useable manner to guide FM decision-makers, who have traditionally not been able to explicitly leverage this information to make evidence-based spending decisions.
Can energy commodities affect energy blockchain-based cryptos?
Authors: Gurrib Ikhlaas 
Published: July 2019

Purpose
The purpose of this paper is to shed fresh light into whether an energy commodity price index (ENFX) and energy blockchain-based crypto price index (ENCX) can be used to predict movements in the energy commodity and energy crypto market.

Design/methodology/approach
Using principal component analysis over daily data of crude oil, heating oil, natural gas and energy based cryptos, the ENFX and ENCX indices are constructed, where ENFX (ENCX) represents 94% (88%) of variability in energy commodity (energy crypto) prices.

Findings
Natural gas price movements were better explained by ENCX, and shared positive (negative) correlations with cryptos (crude oil and heating oil). Using a vector autoregressive model (VAR), while the 1-day lagged ENCX (ENFX) was significant in estimating current ENCX (ENFX) values, only lagged ENCX was significant in estimating current ENFX. Granger causality tests confirmed the two markets do not granger cause each other. One standard deviation shock in ENFX had a negative effect on ENCX. Weak forecasting results of the VAR model, support the two markets are not robust forecasters of each other. Robustness wise, the VAR model ranked lower than an autoregressive model, but higher than a random walk model.

Research limitations/implications
Significant structural breaks at distinct dates in the two markets reinforce that the two markets do not help to predict each other. The findings are limited by the existence of bubbles (December 2017-January 2018) which were witnessed in energy blockchain-based crypto markets and natural gas, but not in crude oil and heating oil.

Originality/value
As per the authors’ knowledge, this is the first paper to analyze the relationship between leading energy commodities and energy blockchain-based crypto markets.
In situ abundance and carbon fixation activity of distinct anoxygenic phototrophs in the stratified seawater lake Rogoznica
Authors: Pjevac Petra , Dyksma Stefan , Goldhammer Tobias , Mujakić Izabela , Koblížek Michal , Mußmann Marc , Amann Rudolf , Orlić Sandi 
Published: July 2019

SummarySulphide‐driven anoxygenic photosynthesis is an ancient microbial metabolism that contributes significantly to inorganic carbon fixation in stratified, sulphidic water bodies. Methods commonly applied to quantify inorganic carbon fixation by anoxygenic phototrophs, however, cannot resolve the contributions of distinct microbial populations to the overall process. We implemented a straightforward workflow, consisting of radioisotope labelling and flow cytometric cell sorting based on the distinct autofluorescence of bacterial photopigments, to discriminate and quantify contributions of co‐occurring anoxygenic phototrophic populations to in situ inorganic carbon fixation in environmental samples. This allowed us to assign 89.3% ± 7.6% of daytime inorganic carbon fixation by anoxygenic phototrophs in Lake Rogoznica (Croatia) to an abundant chemocline‐dwelling population of green sulphur bacteria (dominated by Chlorobium phaeobacteroides), whereas the co‐occurring purple sulphur bacteria (Halochromatium sp.) contributed only 1.8% ± 1.4%. Furthermore, we obtained two metagenome assembled genomes of green sulphur bacteria and one of a purple sulphur bacterium which provides the first genomic insights into the genus Halochromatium, confirming its high metabolic flexibility and physiological potential for mixo‐ and heterotrophic growth.