bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Quorum Sensing Activity in East Antarctic Soil Bacteria
Authors: Wong Sin Yin , Charlesworth James C. , Benaud Nicole , Burns Brendan P. , Ferrari Belinda C. 
Published: August 2019

ABSTRACTAntarctica, being the coldest, driest and windiest continent on Earth, represents the most extreme environment a living organism can thrive in. Under constant exposure to harsh environmental threats, terrestrial Antarctica remains home to a great diversity of microorganisms, indicating that the soil bacteria must have adapted a range of survival strategies that require cell-to-cell communication. Survival strategies include secondary metabolite production, biofilm formation, bioluminescence, symbiosis, conjugation, sporulation and motility, all of which are often regulated by quorum sensing (QS), a type of bacterial communication. Up to now, such mechanisms have not been explored in terrestrial Antarctica. Here, for the first time, LuxI/LuxR-based quorum sensing (QS) activity was delineated in soil bacterial isolates recovered from Adams Flat, in the Vestfold Hills region of East Antarctica. Interestingly, we identified the production of potential homoserine lactones (HSLs) ranging from medium to long chain length in 19 bacterial species using three biosensors, namelyAgrobacterium tumefaciensNTL4,Chromobacterium violaceumCV026 andEscherichia coliMT102, in conjunction with thin layer chromatography (TLC). The majority of detectable HSLs were from gram-positive microorganisms not previously known to produce HSLs. This discovery further expands our understand of the microbial community capable of this type of communication, as well as providing insights into physiological adaptations of microorganisms that allow them to survive in the harsh Antarctic environment.IMPORTANCEQuorum sensing, a type of bacterial communication, is widely known to regulate many processes including those that confer survival advantage. However, little is known about communication by bacteria thriving within Antarctic soils. Employing a combination of bacteria biosensors, analytical techniques, and genome mining, we found a variety of Antarctic soil bacteria speaking a common language, via the LuxI/LuxR-based quorum sensing, thus potentially supporting survival in a mixed microbial community. This is the first report of quorum sensing activity in Antarctic soils and has provided a platform for studying physiological adaptations of microorganisms that allow them to not just survive but thrive in the harsh Antarctic environment.
A morphological analysis of activity-dependent myelination and myelin injury in transitional oligodendrocytes
Authors: Toth Eszter , Rassul Sayed Muhammed , Berry Martin , Fulton Daniel 
Published: August 2019

ABSTRACTNeuronal activity is established as a driver of oligodendrocyte (OL) differentiation and myelination. The concept of activity-dependent myelin plasticity, and its role in cognition and disease, is gaining support. Methods capable of resolving changes in the morphology of individual myelinating OL would advance our understanding of myelin plasticity and injury, thus we adapted a labelling approach involving Semliki Forest Virus (SFV) vectors to resolve and quantify the 3-D structure of OL processes and internodes in cerebellar slice cultures. We first demonstrate the utility of the approach by studying changes in OL morphology after complement-mediated injury. SFV vectors injected into cerebellar white matter labelled transitional OL (TOL), whose characteristic mixture of myelinating and non-myelinating processes exhibited significant degeneration after complement injury. The method was also capable of resolving finer changes in morphology related to neuronal activity. Prolonged suppression of neuronal activity, which reduced myelination, increased the number of TOL processes, while decreasing both the length of putative internodes, and the proportion of myelinating terminal branches. Overall this approach provides novel information on the morphology of TOL, and new opportunities to study the response of OL to conditions that alter circuit function or induce demyelination.
Rac1 is a downstream effector of PKCα in structural synaptic plasticity
Authors: Tu Xun , Yasuda Ryohei , Colgan Lesley A 
Published: August 2019

AbstractStructural and functional plasticity of dendritic spines is the basis of animal learning. The calcium-dependent protein kinase C isoform, PKCα, has been suggested to be critical for this actin-dependent plasticity. However, mechanisms linking PKCα and structural plasticity of spines are unknown. Here, we examine the spatiotemporal activation of actin regulators, including small GTPases Rac1, Cdc42 and Ras, in the presence or absence of PKCα during single-spine structural plasticity. Removal of PKCα expression in the postsynapse attenuated Rac1 activation during structural plasticity without affecting Ras or Cdc42 activity. Moreover, disruption of a PDZ binding domain within PKCα led to impaired Rac1 activation and deficits in structural spine remodeling. These results demonstrate that PKCα positively regulates the activation of Rac1 during structural plasticity.
Cyclin N-Terminal Domain-Containing 1 (CNTD1) coordinates meiotic crossover formation with cell cycle progression in a cyclin-independent manner
Authors: Gray Stephen , Santiago Emerson R. , Chappie Joshua S. , Cohen Paula E. 
Published: August 2019

AbstractDuring meiotic prophase I, programmed DNA double-strand breaks repair as non-crossover or crossover events, the latter predominantly occurring via the Class I crossover pathway and requiring the cyclin family member CNTD1. Using an epitope-taggedCntd1allele, we show that mouse CNTD1 existsin vivoas a short isoform that lacks the predicted N-terminal cyclin domain and does not bind cyclin-dependent kinases. Instead, we find that CNTD1 associates with Replication Factor C to drive crossover formation and the Skp1-Cullin1-F-Box complex to regulate ubiquitination and subsequent degradation of the WEE1 kinase, thereby indirectly modulating cell cycle progression. We propose that these interactions enable CNTD1 to orchestrate the steps of prophase I and coordinate crossover formation with cellular division.
Sex differences in the ability of corticostriatal oscillations to predict rodent alcohol consumption
Authors: Henricks Angela M. , Sullivan Emily D.K. , Dwiel Lucas L. , Keus Karina M. , Adner Ethan D. , Green Alan I. , Doucette Wilder T. 
Published: August 2019

AbstractBackgroundAlthough male and female rats differ in their patterns of alcohol use, little is known regarding the neural circuit activity that underlies these differences in behavior. The current study used a machine learning approach to characterize sex differences in local field potential (LFP) oscillations that may relate to sex differences in alcohol drinking behavior.MethodsLFP oscillations were recorded from the nucleus accumbens shell and the rodent medial prefrontal cortex of adult male and female Sprague-Dawley rats. Recordings occurred before rats were exposed to alcohol (n=10/sex X 2 recordings/rat) and during sessions of limited access to alcohol (n=5/sex X 5 recordings/rat). Oscillations were also recorded from each female rat in each phase of estrous prior to alcohol exposure. Using machine-learning, we built predictive models to classify rats based on: 1) biological sex; 2) phase of estrous; and 3) alcohol intake levels. We evaluated model performance from real data by comparing it to the performance of models built and tested on permutations of the data.ResultsOur data demonstrate that corticostriatal oscillations were able to predict alcohol intake levels in males (p<0.01), but not in females (p=0.45). The accuracies of models predicting biological sex and phase of estrous were related to fluctuations observed in alcohol drinking levels; females in diestrus drank more alcohol than males (p=0.052), and the male vs. diestrus female model had the highest accuracy (71.01%) compared to chance estimates.Conversely, females in estrus drank similar amounts of alcohol to males (p=0.702), and the male vs. estrus female model had the lowest accuracy (56.14%) compared to chance estimates.ConclusionsThe current data demonstrate that oscillations recorded from corticostriatal circuits contain significant information regarding alcohol drinking in males, but not alcohol drinking in females. Future work will focus on identifying where to record LFP oscillations in order to predict alcohol drinking in females, which may help elucidate sex-specific neural targets for future therapeutic development.
HOPS recognizes each SNARE, assembling ternary trans-complexes for sudden fusion upon engagement with the 4th SNARE
Authors: Song Hongki , Orr Amy , Harner Max , Wickner William 
Published: August 2019

ABSTRACTVacuole fusion requires SNAREs, Sec17/18, a Rab, and HOPS. We find that co-incubation of HOPS, proteoliposomes bearing the Rab and R-SNARE, and proteoliposomes with the Rab and any two Q-SNAREs yields a trans complex which includes these 3 SNAREs. The missing Q-SNARE then triggers a burst of fusion, indicating that each HOPS, R-, and QxQy-SNARE trans-complex is an activated intermediate for functional Qz-SNARE incorporation. HOPS can assemble activated fusion intermediates because it recognizes each of the four SNAREs, binding them independently. HOPS-dependent fusion is saturable for each Q-SNARE, indicating saturable functional sites on HOPS. Though a nonspecific tether allows fusion with pre-assembled Q-SNAREs, only HOPS catalyzes fusion when the Q-SNAREs are not pre-assembled by ushering each Q-SNARE into a functional complex. In contrast, there is little spontaneous functional assembly of the 3 Q-SNAREs. HOPS thus recognizes each of the 4 SNAREs to assemble a versatile set of activated fusion intermediates.
Investigations on strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental forming
Authors: Yoganjaneyulu G. , Ravikumar V.V. , Sathiya Narayanan C. 
Published: August 2019

Purpose
The purpose of this paper is to investigate the strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental forming (SPIF) process, with various computerized numerical control (CNC) spindle rotational speeds and step depths. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during the SPIF process.

Design/methodology/approach
A potentiodynamic polarization (PDP) study was performed to investigate the corrosion behaviour of titanium Grade 2 deformed samples, with various spindle rotational speeds in 3.5 (%) NaCl solution. The scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was carried out to study the fracture behaviour, dislocation densities and corrosion morphology of deformed samples.

Findings
The titanium Grade 2 sheets exhibited better strain distribution, fracture limit and corrosion resistance by increasing the CNC spindle rotational speeds, tool diameters and vertical step depths (VSD). It was recorded that varying the spindle speed affected plastic deformation which in turn affected corrosion rate.

Research limitations/implications
In this study, poor corrosion rate was observed for the as-received condition, and better corrosion rate was achieved at maximum speed of 600 rpm and 0.6 mm of VSD in the deformed sheet. This indicates that corrosion rate improved with increase in the plastic deformation. The EDS analysis report of corroded surface revealed the composition to be mainly of titanium and oxides.

Practical implications
This study discusses the strain distribution, stress-based fracture limit and corrosion behaviour by using titanium Grade 2 sheets during SPIF process.

Social implications
This study is useful in the field of automobile and industrial applications.

Originality/value
With an increase in the spindle rotational speeds and VSD, the titanium Grade 2 sheets showed better strain distribution, fracture limit and corrosion behaviour; the same is evidenced in fracture limit curve and PDP curves.
The rise of social networking sites
Authors: Naqvi Mishal , Li Shan , Jiang Yushi , Naqvi Muhammad Hasnain Abbas 
Published: August 2019

PurposeThe purpose of this paper is to investigate the impact of the technology acceptance model, privacy concerns and demographic factors on intention to use (ITU) social networking sites (SNSs).Design/methodology/approachA questionnaire survey was developed and administered to a convenience sample of 838 university students.FindingsThe findings indicate that perceived privacy, demographic factors and perceived usefulness (PU) have a significant effect on the ITU SNSs, and that age does not moderate the relationship between perceived ease-of-use and PU.Originality/valueThis study confirms the growing importance of SNSs. It also provides social networking service providers with insights into user intentions towards such networks.
Women directors and performance: evidence from Malaysia
Authors: Lim Kwee Pheng , Lye Chun-Teck , Yuen Yee Yen , Teoh Wendy Ming Yen 
Published: August 2019

PurposeThe purpose of this paper is to examine the relationship between women on board and the financial performance of Malaysian listed companies.Design/methodology/approachPanel generalised method of moments (GMM) analysis was used over 928 public-listed companies listed on the Malaysian Stock Exchange from 2010 to 2016. GMM overcomes the problem of endogeneity and simultaneity bias. The dependent variable was firm performance, measured by Tobin’sQ. The explanatory variable was gender diversity, proxied by the percentage of women on board, the presence of women and gender heterogeneity indices, Blau and Shannon indices.FindingsMore gender diversification leads to declining firm performance possibly due to issues of tokenism and gender stereotypes.Research limitations/implicationsFurther studies should look into the impact of various types of ownership structures on firm value and also by sectors.Practical implicationsAs women represent half the population in Malaysia, more positive affirmative policies must be introduced to enhance their contributions to society.Social implicationsAs women progress in society, their contributions towards nation building will be significant. Women not only play a nurturing role, but also can shape the destiny of a country.Originality/valueStudies on the relationship between board gender diversity and financial performance have been conducted in the context of a few developed economies. This study contributes to the literature by examining such an issue in a developing economy that has a different environment from that of developed economies.
Microaggression experiences of different marginalized identities
Authors: Nair Nisha , Good Deborah Cain , Murrell Audrey J. 
Published: August 2019

Purpose
Given the nascent stage of research on microaggressions, the study is an attempt to better understand the experience of microaggressions and examine it from the point of view of different marginalized minority identities. The purpose of this paper is to report on the subjective experience of microaggressions from the lenses of gender, race, religion and sexual orientation.

Design/methodology/approach
To explore how microaggressions are experienced by different identities, the authors conducted four focus group studies with university students at a prominent Midwestern university. Each focus group focused on the experience of microaggressions for a particular identity group.

Findings
The authors discuss the nature and forms of exclusion that occur through microaggressions, and offer six microaggression themes that emerged as common across the marginalized identities studied. The authors add to the microaggression taxonomy and highlight the role of repetition in how microaggressions are perceived. The authors also discuss intersectional microaggressions.

Originality/value
While various studies have focused on reporting microaggression themes with regard to singular identities, this study is potentially the first that explores microaggression themes across different marginalized identities. The findings highlight novel forms of microaggressions such as the revealing or making visible of marginalized identities, and microaggressions emanating from within a minority group directed at other members within the same identity group, what the authors call as in-group microaggressions. The authors highlight and point to the need for more work on intersectional microaggressions.
Enhanced heat transfer in a labyrinth channels with ribs of different shape
Authors: Du Wei , Luo Lei , Wang Songtao , Liu Jian , Sunden Bengt Ake 
Published: August 2019

Purpose
The purpose of this study is to enhance the thermal performance in the labyrinth channel by different ribs shape. The labyrinth channel is a relatively new cooling structure to decrease the temperature near the trailing region of gas turbine.

Design/methodology/approach
Based on the geometric similarity, a simplified geometric model is used. The k − ω turbulence model is used to close the Navier–Stokes equations. Five rib shapes (one rectangular rib, two arched ribs and two trapezoid ribs) and five Reynolds numbers (10,000 to 50,000) are considered. The Nusselt number, flow structure and friction factor are analyzed.

Findings
Nusselt number is tightly related to the rib shape in the labyrinth channel. The different shapes of the ribs result in different horseshoe vortex and wake region. In general, the arched rib brings the highest Nusselt number and friction factor. The Nusselt number is increased by 15.8 per cent compared to that of trapezoidal ribs. High Nusselt number is accompanied by the high friction factor in a labyrinth channels. The friction factor is increased by 64.6 per cent compared to rectangular ribs. However, the rib shape has a minor effect on the overall thermal performance.

Practical implications
This study is useful to protect the trailing region of advanced gas turbine.

Originality/value
This paper presents the flow structure and heat transfer characteristics in a labyrinth channel with different rib shapes.
Effects of magnetic field on the liquid gallium thermosyphon fluid flow; a numerical study
Authors: Teimouri Hamid , Behzadmehr Amin 
Published: August 2019

Purpose
This paper aims to numerically study the laminar natural convection in a thermosyphon filled with liquid gallium exposed to a constant magnetic field. The left wall of the thermosyphon is at an uniformed hot temperature, whereas the right wall is at a uniform cold temperature. The top and bottom walls are considered to be adiabatic. All walls are electrically insulated. The effects of Hartmann number, in a wide range of Rayleigh number and aspect ratio combinations, on the natural convection throughout the thermosyphon, are investigated and discussed. Furthermore, different forces that influence the natural flow structure are studied.

Design/methodology/approach
A Fortran code is developed based on the finite volume method to solve the two-dimensional unsteady governing equations.

Findings
Imposing a magnetic field improves the stability of the fluid flow and thus reduces the Nusselt number. For a given Hartmann and Rayleigh number, there is an optimum aspect ratio for which the average velocity becomes maximum.

Research limitations/implications
This paper is a two-dimensional investigation.

Originality/value
To the best of the authors’ knowledge, the effect of the magnetic field on natural convection of liquid gallium in the considered thermosyphon has not been studied numerically in detail. The results of this paper would be helpful in considering the application of the low Prandtl number’s liquid metals in thermosyphon MHD generators and certain cooling devices.
Enhanced understanding of leakage in mechanical seals with elliptical dimples based on CFD simulation
Authors: Jiang Sen , Ji Hua , Wang Tianhao , Feng Donglin , Li Qian 
Published: August 2019

Purpose
The shapes of surface textures have been designed to control the leakage of mechanical seals in recent years. The purpose of this paper is to demonstrate the influence of geometric properties of elliptical dimples on the leakage rate.

Design/methodology/approach
A new geometric feature point is expressed using an analytical solution to locate the high-pressure zones. Furthermore, a numerical model of the three-dimensional flow field for the mechanical seal with elliptical dimples is developed using ANSYS Fluent to demonstrate the influencing mechanism.

Findings
The location of the proposed geometric converging point coincides with the maximum pressure point under different orientation angles. An inward flow on the leakage section observed from the simulation results is responsible for decreasing the leakage rate.

Originality/value
The influencing mechanism of the elliptical dimple on the leakage rate is demonstrated, which can facilitate the design of surface textures.
Tribological properties of carbonized polydopamine/rGO composite coatings
Authors: Yang Ming , Jia Zhengfeng , Wei Denghu , Wang Yunxia , Pang Xianjuan , Zhen Jinming , Zhang Ran , Yu Bo 
Published: August 2019

Purpose
The purpose of this paper is to investigate the tribological properties of carbonized polydopamine/reduced graphene oxide (CPDA/rGO) composite coatings.

Design/methodology/approach
CPDA/rGO composite coatings were prepared using the spray technique and subsequent pyrolysis under argon. The transmission electron microscopy, field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy revealed the conversion of PDA and GO into CPDA and rGO, respectively.

Findings
The results of tribological investigations show that the CPDA/rGO composite coatings with heat treatment at 300°C possess much better friction-reduction and anti-wear properties.

Originality/value
The worn surfaces of the PDA/GO composite films after heat treatment at 300°C were much smoother than that of the copper substrate. The tribofilms containing C, N, O and Cu played an important role on reducing friction and increasing wear resistance.
Bundling cloud software to fight piracy: an economic analysis
Authors: Zhang Xiong , Yue Wei T. , Hui Wendy 
Published: August 2019

Purpose
The emergence of internet-enabled technology has led to the software service model in which the software firm, instead of the consumer, maintains software ownership. This model can curtail software piracy more effectively than the traditional on-premises software model. However, software firms are not abandoning traditional on-premises software but embracing both models simultaneously. In this study, the authors consider a firm’s software bundling decision in combination with its piracy deterrence strategy. The paper aims to discuss these issues.

Design/methodology/approach
The authors build three stylized models to analytically compare the bundling strategies under three scenarios: no piracy, piracy is present and piracy is present while the firm applies digital rights management (DRM).

Findings
The authors find pure bundling (PB) to be the optimal strategy due to the combination of competition and cannibalization effects in mixed bundling (MB). Simultaneously, consumers may enjoy greater surplus in PB than in MB, making PB the preferred strategy for both the firm and consumers. Interestingly, the win-win outcome coexists with some degree of piracy in the market.

Originality/value
The results provide important insights for firms and policy-makers and contribute to the literature on piracy and product bundling. First, the authors show piracy could be another driver for product bundling, which has never been discussed in prior literature. Second, the authors suggest an alternative perspective; that PB may be a desirable outcome for both firms and consumers when considering piracy and DRM. More surprisingly, this desirable outcome occurs with some level of piracy in the market. The presence of piracy leads to competition and cannibalization effects in MB, which eventually results in the win-win outcome in the software market for both the firm and the consumers.