bluuebunny/crossref_metadata_2025 huggingface dataset:
Top Management Team Demographic Diversities, Generic Strategy and Firm Performance in Marketing Social Research Association (MSRA) in Kenya
Authors: Yohannes Tecle H. , Ayako Aloys B.
Published: May 2016

This study investigated the relationship between Top Management Team (TMT) demographic diversities and firm performance using generic strategies as intervening variable in the Marketing and Social Research Association (MSRA) firms in Kenya. First, the relationship between TMT characteristics diversities and generic strategy was analyzed. Second, the link between generic strategy and firm performance was estimated. Mixed methods research design was used to critically investigate the relationship between the latent exogenous and endogenous variables of this study. The mixed research design used in this study was triangulation design, which was mainly transformation design model. The data were analyzed using structural equation modeling analysis, using IBM SPSS AMOS version 21. The study found out that the homogenous demographic diversities among the top management team members had statistically significant effect on cost leadership strategy (p = 0.012). Besides, cost leadership strategy showed a statistically significant positive relationship on firm performance (p = 0.005). The findings of this study implied that organizations need to know and develop the best composition of top management team based on their demographic diversities in relation to the environment. Besides, the organizations need to empower the TMT members using monetary and nonmonetary incentives to further improve performance. Last but not least, the compositions of TMT in marketing research firms need to embrace gender diversity.
A Characteristic-Based Constitutive Law for Dispersed Fibers
Authors: Ge Liang
Published: May 2016

Biological tissues are typically constituted of dispersed fibers. Modeling the constitutive laws of such tissues remains a challenge. Direct integration over all fibers is considered to be accurate but requires very expensive numerical integration. A general structure tensor (GST) model was previously developed to bypass this costly numerical integration step, but there are concerns about the model's accuracy. Here we estimate the approximation error of the GST model. We further reveal that the GST model ignores strain energy induced by shearing motions. Subsequently, we propose a new characteristic-based constitutive law to better approximate the direct integration model. The new model is very cost-effective and closely approximates the “true” strain energy as calculated by the direct integration when stress–strain nonlinearity or fiber dispersion angle is small.
Effect of Deep Cold Rolling on Residual Stress Distributions Between the Treated and Untreated Regions on Ti–6Al–4V Alloy
Authors: Lim Andre , Castagne Sylvie , Cher Wong Chow
Published: May 2016

The residual stress distributions caused by the deep cold rolling (DCR) process, with a focus on the distributions at the boundary of the treatment zone, are examined in this study. A three-dimensional finite-element (FE) model, validated with experimental residual stress data, is used to study the effect of the process. The residual stress distribution in the crosswise direction (perpendicular to rolling direction) shows a region of tensile residual stress at the start and end of the track that may be a cause for concern. The reason for this region of tensile stress is likely to be due to the reduced treatment of the start and end zones due to the step over and the tool path taken. Other factors that cause a difference between the steady state and the transient zone of the burnished area are also investigated. It is shown that the net material movement causes larger plastic deformation in the boundary zone between the burnished and unburnished region of DCR.
Local Hydrostatic Pressure Test for Cylindrical Vessels
Authors: Al-Gahtani H. , Khathlan A. , Sunar M. , Naffa'a M.
Published: May 2016

The juncture of a small cylindrical nozzle to a large cylindrical vessel is very common in the pressure vessel industry. Upon fabrication, it is required that the whole structure is subjected to pressure testing. The test can be expensive as it necessitates pressurizing the whole structure typically having a large volume. Hence, it is proposed to make a “local test,” which is considerably simpler as it involves capping the small nozzle and testing only a relatively small portion of the structure. This paper investigates the accuracy and reliability of such an alternative test, using the finite-element method. Two different finite-element types are used in the study, specifically a shell-based element and a solid-based element. The verification of the finite-element results for two different cases shows that the models used in the study are valid. It also proves that the two element types yield very similar stress results. In addition, the study includes a numerical investigation of more than 40 different nozzle-to-vessel junctures with a wide range of parameters for the nozzle and vessel. The results indicate that the use of cylindrical caps that are slightly larger than the nozzle is not recommended as it produces stresses that are significantly different from those for the original required pressure test. As such, the study provides an estimate of the smallest size of the cap that may be used in the local test to generate stresses that agree with the full test. For most practical geometries, it is shown that the size of the cap needs to be at least 2–30 times larger than that of the nozzle, depending on the geometrical parameters of the juncture.
Analytical Solution for Three-Dimensional, Unsteady Heat Conduction in a Multilayer Sphere
Authors: Singh Suneet , Jain Prashant K. , Rizwan-uddin
Published: May 2016

An analytical solution has been obtained for the transient problem of three-dimensional multilayer heat conduction in a sphere with layers in the radial direction. The solution procedure can be applied to a hollow sphere or a solid sphere composed of several layers of various materials. In general, the separation of variables applied to 3D spherical coordinates has unique characteristics due to the presence of associated Legendre functions as the eigenfunctions. Moreover, an eigenvalue problem in the azimuthal direction also requires solution; again, its properties are unique owing to periodicity in the azimuthal direction. Therefore, extending existing solutions in 2D spherical coordinates to 3D spherical coordinates is not straightforward. In a spherical coordinate system, one can solve a 3D transient multilayer heat conduction problem without the presence of imaginary eigenvalues. A 2D cylindrical polar coordinate system is the only other case in which such multidimensional problems can be solved without the use of imaginary eigenvalues. The absence of imaginary eigenvalues renders the solution methodology significantly more useful for practical applications. The methodology described can be used for all the three types of boundary conditions in the outer and inner surfaces of the sphere. The solution procedure is demonstrated on an illustrative problem for which results are obtained.
Influence of laminate sequence and fabric type on the inherent acoustic nonlinearity in carbon fiber reinforced composites
Authors: Chakrapani Sunil Kishore , Barnard Daniel J. , Dayal Vinay
Published: May 2016

This paper presents the study of influence of laminate sequence and fabric type on the baseline acoustic nonlinearity of fiber-reinforced composites. Nonlinear elastic wave techniques are increasingly becoming popular in detecting damage in composite materials. It was earlier observed by the authors that the non-classical nonlinear response of fiber-reinforced composite is influenced by the fiber orientation [Chakrapani, Barnard, and Dayal, J. Acoust. Soc. Am. 137(2), 617–624 (2015)]. The current study expands this effort to investigate the effect of laminate sequence and fabric type on the non-classical nonlinear response. Two hypotheses were developed using the previous results, and the theory of interlaminar stresses to investigate the influence of laminate sequence and fabric type. Each hypothesis was tested by capturing the nonlinear response by performing nonlinear resonance spectroscopy and measuring frequency shifts, loss factors, and higher harmonics. It was observed that the laminate sequence can either increase or decrease the nonlinear response based on the stacking sequence. Similarly, tests were performed to compare unidirectional fabric and woven fabric and it was observed that woven fabric exhibited a lower nonlinear response compared to the unidirectional fabric. Conjectures based on the matrix properties and interlaminar stresses were used in an attempt to explain the observed nonlinear responses for different configurations.
Gaps-in-noise detection and gender identification from noise-vocoded vowel segments: Comparing performance of active musicians to non-musicians
Authors: Donai Jeremy J. , Jennings Mariah B.
Published: May 2016

This study evaluated performance on a gender identification and temporal resolution task among active musicians and age-matched non-musicians. Brief duration (i.e., 50 and 100 ms) vowel segments produced by four adult male and four adult female speakers were spectro-temporally degraded using various parameters and presented to both groups for gender identification. Gap detection thresholds were measured using the gaps-in-noise (GIN) test. Contrary to the stated hypothesis, a significant difference in gender identification was not observed between the musician and non-musician listeners. A significant difference, however, was observed on the temporal resolution task, with the musician group achieving approximately 2 ms shorter gap detection thresholds on the GIN test compared to the non-musician counterparts. These results provide evidence supporting the potential benefits of musical training on temporal processing abilities, which have implications for the processing of speech in degraded listening environments and the enhanced processing of the fine-grained temporal aspects of the speech signal. The results also support the GIN test as an instrument sensitive to temporal processing differences among active musicians and non-musicians.
Mid-bandwidth loudness depression in hearing-impaired listeners
Authors: Hots Jan , Jarzombek Katrin , Verhey Jesko L.
Published: May 2016

The loudness of a bandpass-filtered noise depends on its bandwidth. For bandwidths larger than a critical bandwidth, loudness increases as the bandwidth increases, an effect commonly referred to as spectral loudness summation. For bandwidths smaller than the critical bandwidth, it was shown recently for normal-hearing listeners that loudness decreases as the bandwidth increases. This study investigated if listeners with a hearing impairment of primarily cochlear origin also showed this effect. Levels at equal loudness between a 1500-Hz pure-tone reference and noise-band targets centered at 1500 Hz were measured for bandwidths in the range from 15 to 1620 Hz. The reference level was adjusted individually on the basis of the audiogram. The average level difference at equal loudness increased from 0 dB at 15 Hz up to a maximum of about 4 dB at 810 Hz. Thus, the mid-bandwidth loudness depression is also observed for hearing-impaired listeners.
Differences in Oxygenation Kinetics Between the Dominant and Nondominant Flexor Digitorum Profundus in Rock Climbers
Authors: Giles David , Romero Vanesa España , Garrido Inmaculada , de la O Puerta Alejandro , Stone Keeron , Fryer Simon
Published: May 2016

Purpose:

To examine differences in oxygenation kinetics in the nondominant and dominant flexor digitorum profundus (FDP) of rock climbers.

Methods:

Participants were 28 sport climbers with a range of on-site abilities (6a+ to 8a French Sport). Using near-infrared spectroscopy, oxygenation kinetics of the FDP was assessed by calculating the time to half recovery (t1/2 recovery) of the tissue-saturation index (TSI) after 3–5 min of ischemia.

Results:

A 2-way mixed-model ANOVA found a nonsignificant interaction (P = .112) for TSI by sex. However, there was a significant main effect (P = .027) of handedness (dominant vs nondominant FDP). The dominant forearm recovered 13.6% faster (t1/2 recovery mean difference = 1.12 s, 95% CI 0.13–2.10 s) than the nondominant FDP. This was not affected by 6-mo on-site climbing ability or sex (P = .839, P = .683).

Conclusions:

Significant intraindividual differences in oxygenation kinetics of the FDP were found. Improvements in oxygenation kinetics in the FDP are likely due to the abilities of the muscle to deliver, perfuse, and consume oxygen. These enhancements may be due to structural adaptations in the microvasculature, such as an increase in capillary density and enhanced improvement in capillary filtration.
Experiencing Flow in a Workplace Physical Activity Intervention for Female Health Care Workers: A Longitudinal Comparison between Football and Zumba
Authors: Elbe Anne-Marie , Barene Svein , Strahler Katharina , Krustrup Peter , Holtermann Andreas
Published: May 2016

Flow is a rewarding psychological state that motivates individuals to repeat activities. This study explored healthcare workers’ flow experiences during a workplace exercise intervention. Seventy-nine females were assigned to either a 12-week football or Zumba exercise intervention and their flow experiences were assessed at the beginning, midway and at the end of the intervention. The results showed that both intervention groups experienced medium levels of flow and an increase in flow values over time. A significant positive correlation between experiencing flow midway through the intervention and adherence to regular physical activity 18 weeks after the end of the intervention was found. Furthermore, repeated measures throughout the intervention period showed a significantly different development of flow values over time for the adherers and nonadherers. Flow therefore may be of importance for adherence to regular workplace physical activity. Future research needs to investigate the importance of flow in other physical activity settings, especially also for male participants.
Notch signaling in group 3 innate lymphoid cells modulates their plasticity
Authors: Chea Sylvestre , Perchet Thibaut , Petit Maxime , Verrier Thomas , Guy-Grand Delphine , Banchi Elena-Gaia , Vosshenrich Christian A. J. , Di Santo James P. , Cumano Ana , Golub Rachel
Published: May 2016

The balance in the proportions of innate lymphoid cell subsets depends on signaling by the receptor Notch2.
IP
6
in chromosome dynamics
Authors: Gough Nancy R.
Published: May 2016

Structural analysis of the cohesin-regulating protein PDS5 reveals inositol hexakisphosphate as a binding partner.
New connections: Regulating innate lymphoid cells
Authors: Foley John F.
Published: May 2016

Studies reveal mechanisms underlying the differentiation and regulation of innate lymphoid cell subsets.
New neural measures signal autism
Authors: Fung Lawrence K.
Published: May 2016

Function of a social perception circuit was successfully quantified and replicated in males with autism.
Detection of Carbapenemase Genes in Aquatic Environments in Rio de Janeiro, Brazil
Authors: de Araujo Carlos Felipe Machado , Silva Dalton Marcondes , Carneiro Marcos Tavares , Ribeiro Sthefanie , Fontana-Maurell Marcela , Alvarez Patricia , Asensi Marise Dutra , Zahner Viviane , Carvalho-Assef Ana Paula D'Alincourt
Published: May 2016

This study reveals the presence of different carbapenemase genes (
bla
KPC
,
bla
NDM
,
bla
GES
, and
bla
OXA48-like
genes) detected directly from water samples and clonal dispersion (by pulsed-field gel electrophoresis [PFGE] and multilocus sequence typing [MLST]) of KPC-2-producing
Enterobacteriaceae
in two important urban aquatic matrixes from Rio de Janeiro, Brazil, highlighting the role of aquatic environments as gene pools and the possibility of community spreading.
Anti-infective Activity of 2-Cyano-3-Acrylamide Inhibitors with Improved Drug-Like Properties against Two Intracellular Pathogens
Authors: Passalacqua Karla D. , Charbonneau Marie-Eve , Donato Nicholas J. , Showalter Hollis D. , Sun Duxin , Wen Bo , He Miao , Sun Hanshi , O'Riordan Mary X. D. , Wobus Christiane E.
Published: May 2016

Due to the rise of antibiotic resistance and the small number of effective antiviral drugs, new approaches for treating infectious diseases are urgently needed. Identifying targets for host-based therapies represents an emerging strategy for drug discovery. The ubiquitin-proteasome system is a central mode of signaling in the eukaryotic cell and may be a promising target for therapies that bolster the host's ability to control infection. Deubiquitinase (DUB) enzymes are key regulators of the host inflammatory response, and we previously demonstrated that a selective DUB inhibitor and its derivative promote anti-infective activities in host cells. To find compounds with anti-infective efficacy but improved toxicity profiles, we tested a library of predominantly 2-cyano-3-acrylamide small-molecule DUB inhibitors for anti-infective activity in macrophages against two intracellular pathogens: murine norovirus (MNV) and
Listeria monocytogenes
. We identified compound C6, which inhibited DUB activity in human and murine cells and reduced intracellular replication of both pathogens with minimal toxicity in cell culture. Treatment with C6 did not significantly affect the ability of macrophages to internalize virus, suggesting that the anti-infective activity interferes with postentry stages of the MNV life cycle. Metabolic stability and pharmacokinetic assays showed that C6 has a half-life in mouse liver microsomes of ∼20 min and has a half-life of approximately 4 h in mice when administered intravenously. Our results provide a framework for targeting the host ubiquitin system in the development of host-based therapies for infectious disease. Compound C6 represents a promising tool with which to elucidate the role of DUBs in the macrophage response to infection.
Real-Time PCR Reveals Rapid Dissemination of Leptospira interrogans after Intraperitoneal and Conjunctival Inoculation of Hamsters
Authors: Wunder Elsio A. , Figueira Claudio P. , Santos Gisele R. , Lourdault Kristel , Matthias Michael A. , Vinetz Joseph M. , Ramos Eduardo , Haake David A. , Picardeau Mathieu , dos Reis Mitermayer G. , Ko Albert I.
Published: May 2016

The pathogen
Leptospira interrogans
is a highly motile spirochete that causes acute and fulminant infections in humans and other accidental hosts. Hematogenous dissemination is important for infection by the pathogen but remains poorly understood because few animal model studies have used sensitive tools to quantify the bacteria. We evaluated the kinetics of leptospiral infection in Golden Syrian hamsters by a sensitive quantitative real-time PCR (TaqMan) with
lipl32
as the target gene. The dissemination and bacterial burden were measured after intraperitoneal infection with a high dose (10
8
) or low dose (2.5 × 10
2
) of leptospires. We also examined the conjunctival challenge route to mimic the natural history of infection. Quantification of leptospires in perfused animals revealed that pathogens were detected in all organs of intraperitoneally infected hamsters, including the eye and brain, within 1 h after inoculation of 10
8
virulent
L. interrogans
bacteria. Peaks of 10
5
to 10
8
leptospires per gram or per milliliter were achieved in blood and all tissues between day 4 and day 8 after intraperitoneal inoculation of high- and low-dose challenges, respectively, coinciding with macroscopic and histological changes. The conjunctival route resulted in a delay in the time to peak organ burden in comparison to intraperitoneal infection, indicating that although infection could be established, penetration efficiency was low across this epithelial barrier. Surprisingly, infection with a large inoculum of high-passage-number attenuated
L. interrogans
strains resulted in dissemination to all organs in the first 4 days postinfection, albeit with a lower burden, followed by clearance from the blood and organs 7 days postinfection and survival of all animals. These results demonstrate that leptospiral dissemination and tissue invasion occur. In contrast, development of a critical level of tissue burden and pathology are dependent on the virulence of the infecting strain.
Rapid Curtailing of the Stringent Response by Toxin-Antitoxin Module-Encoded mRNases
Authors: Tian Chengzhe , Roghanian Mohammad , Jørgensen Mikkel Girke , Sneppen Kim , Sørensen Michael Askvad , Gerdes Kenn , Mitarai Namiko
Published: May 2016

Escherichia coli
regulates its metabolism to adapt to changes in the environment, in particular to stressful downshifts in nutrient quality. Such shifts elicit the so-called stringent response, coordinated by the alarmone guanosine tetra- and pentaphosphate [(p)ppGpp]. On sudden amino acid (aa) starvation, RelA [(p)ppGpp synthetase I] activity is stimulated by binding of uncharged tRNAs to a vacant ribosomal site; the (p)ppGpp level increases dramatically and peaks within the time scale of a few minutes. The decrease of the (p)ppGpp level after the peak is mediated by the decreased production of mRNA by (p)ppGpp-associated transcriptional regulation, which reduces the vacant ribosomal A site and thus constitutes negative feedback to the RelA-dependent (p)ppGpp synthesis. Here we showed that on sudden isoleucine starvation, this peak was higher in an
E. coli
strain that lacks the 10 known mRNase-encoding toxin-antitoxin (TA) modules present in the wild-type (wt) strain. This observation suggested that toxins are part of the negative-feedback mechanism to control the (p)ppGpp level during the early stringent response. We built a ribosome trafficking model to evaluate the fold increase in RelA activity just after the onset of aa starvation. Combining this with a feedback model between the (p)ppGpp level and the mRNA level, we obtained reasonable fits to the experimental data for both strains. The analysis revealed that toxins are activated rapidly, within a minute after the onset of starvation, reducing the mRNA half-life by ∼30%.

IMPORTANCE
The early stringent response elicited by amino acid starvation is controlled by a sharp increase of the cellular (p)ppGpp level. Toxin-antitoxin module-encoded mRNases are activated by (p)ppGpp through enhanced degradation of antitoxins. The present work shows that this activation happens over a very short time scale and that the activated mRNases negatively affect the (p)ppGpp level. The proposed mathematical model of (p)ppGpp regulation through the mRNA level highlights the importance of several feedback loops in early (p)ppGpp regulation.
Promoter Recognition by Extracytoplasmic Function σ Factors: Analyzing DNA and Protein Interaction Motifs
Authors: Guzina Jelena , Djordjevic Marko
Published: May 2016

E
xtra
c
ytoplasmic
f
unction (ECF) σ factors are the largest and the most diverse group of alternative σ factors, but their mechanisms of transcription are poorly studied. This subfamily is considered to exhibit a rigid promoter structure and an absence of mixing and matching; both −35 and −10 elements are considered necessary for initiating transcription. This paradigm, however, is based on very limited data, which bias the analysis of diverse ECF σ subgroups. Here we investigate DNA and protein recognition motifs involved in ECF σ factor transcription by a computational analysis of canonical ECF subfamily members, much less studied ECF σ subgroups, and the group outliers, obtained from recently sequenced bacteriophages. The analysis identifies an extended −10 element in promoters for phage ECF σ factors; a comparison with bacterial σ factors points to a putative 6-amino-acid motif just C-terminal of domain σ
2
, which is responsible for the interaction with the identified extension of the −10 element. Interestingly, a similar protein motif is found C-terminal of domain σ
2
in canonical ECF σ factors, at a position where it is expected to interact with a conserved motif further upstream of the −10 element. Moreover, the phiEco32 ECF σ factor lacks a recognizable −35 element and σ
4
domain, which we identify in a homologous phage, 7-11, indicating that the extended −10 element can compensate for the lack of −35 element interactions. Overall, the results reveal greater flexibility in promoter recognition by ECF σ factors than previously recognized and raise the possibility that mixing and matching also apply to this group, a notion that remains to be biochemically tested.

IMPORTANCE
ECF σ factors are the most numerous group of alternative σ factors but have been little studied. Their promoter recognition mechanisms are obscured by the large diversity within the ECF σ factor group and the limited similarity with the well-studied housekeeping σ factors. Here we extensively compare bacterial and bacteriophage ECF σ factors and their promoters in order to infer DNA and protein recognition motifs involved in transcription initiation. We predict a more flexible promoter structure than is recognized by the current paradigm, which assumes rigidness, and propose that ECF σ promoter elements may complement (mix and match with) each other's strengths. These results warrant the refocusing of research efforts from the well-studied housekeeping σ factors toward the physiologically highly important, but insufficiently understood, alternative σ factors.
Diurnal Regulation of Cellular Processes in the Cyanobacterium
Synechocystis
sp. Strain PCC 6803: Insights from Transcriptomic, Fluxomic, and Physiological Analyses
Authors: Saha Rajib , Liu Deng , Hoynes-O’Connor Allison , Liberton Michelle , Yu Jingjie , Bhattacharyya-Pakrasi Maitrayee , Balassy Andrea , Zhang Fuzhong , Moon Tae Seok , Maranas Costas D. , Pakrasi Himadri B.
Published: May 2016

Synechocystis
sp. strain PCC 6803 is the most widely studied model cyanobacterium, with a well-developed omics level knowledgebase. Like the lifestyles of other cyanobacteria, that of
Synechocystis
PCC 6803 is tuned to diurnal changes in light intensity. In this study, we analyzed the expression patterns of all of the genes of this cyanobacterium over two consecutive diurnal periods. Using stringent criteria, we determined that the transcript levels of nearly 40% of the genes in
Synechocystis
PCC 6803 show robust diurnal oscillating behavior, with a majority of the transcripts being upregulated during the early light period. Such transcripts corresponded to a wide array of cellular processes, such as light harvesting, photosynthetic light and dark reactions, and central carbon metabolism. In contrast, transcripts of membrane transporters for transition metals involved in the photosynthetic electron transport chain (e.g., iron, manganese, and copper) were significantly upregulated during the late dark period. Thus, the pattern of global gene expression led to the development of two distinct transcriptional networks of coregulated oscillatory genes. These networks help describe how
Synechocystis
PCC 6803 regulates its metabolism toward the end of the dark period in anticipation of efficient photosynthesis during the early light period. Furthermore,
in silico
flux prediction of important cellular processes and experimental measurements of cellular ATP, NADP(H), and glycogen levels showed how this diurnal behavior influences its metabolic characteristics. In particular, NADPH/NADP
+
showed a strong correlation with the majority of the genes whose expression peaks in the light. We conclude that this ratio is a key endogenous determinant of the diurnal behavior of this cyanobacterium.

IMPORTANCE
Cyanobacteria are photosynthetic microbes that use energy from sunlight and CO
2
as feedstock. Certain cyanobacterial strains are amenable to facile genetic manipulation, thus enabling synthetic biology and metabolic engineering applications. Such strains are being developed as a chassis for the sustainable production of food, feed, and fuel. To this end, a holistic knowledge of cyanobacterial physiology and its correlation with gene expression patterns under the diurnal cycle is warranted. In this report, a genomewide transcriptional analysis of
Synechocystis
PCC 6803, the most widely studied model cyanobacterium, sheds light on the global coordination of cellular processes during diurnal periods. Furthermore, we found that, in addition to light, the redox level of NADP(H) is an important endogenous regulator of diurnal entrainment of
Synechocystis
PCC 6803.
Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country
Authors: Boucher Yan
Published: May 2016

Although the current cholera pandemic can trace its origin to a specific time and place, many variants of
Vibrio cholerae
have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in
mBio
presents the results of more than 3 decades of
V. cholerae
monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016,
http://dx.doi.org/10.1128/mBio.02160-15
). It reveals that multiple
V. cholerae
variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of
V. cholerae
.
Risk Factors for Osteoporosis in a Subgroup of Elderly Men in a Veterans Administration Nursing Home
Authors: Yeh Shing-Shing , Phanumas Donna , Hafner Alice , Schuster Michael W.
Published: May 2016

Background

General risk factors for osteoporosis in men include cigarette smoking, alcohol consumption, and diseases known to affect calcium or bone turnover. The aim of this study was to determine the specific incidence and major risk factors for osteoporosis in those at high risk for falling in a Veterans Administration nursing home that included a high proportion of psychiatric patients.

Methods

We performed a cross-sectional analysis of Veterans Administration Medical Center nursing home residents with high fall risk. Thirty-nine men with a previous episode of falling or who were considered to be at high fall risk were enrolled. A review of the medical histories and pertinent hormonal and biochemical laboratory values was performed. Bone mineral density was measured by performing dual energy x-ray absorptiometry for all participants.

Results

We reviewed the medical records of 39 male nursing home residents with high fall risk. The patients’ mean age was 74.7±6.8 years. A significant (p=0.00045) association was found between chronic obstructive pulmonary disease and osteoporosis independent of oral corticosteroid use. Additional risk factors found to be associated with osteoporosis included hypogonadism, lower body weight, antipsychotic medication use, and smoking.

Conclusion

In a Veterans Administration nursing home population at high risk for falls, including psychiatric patients, chronic obstructive pulmonary disease independent of the use of corticosteroids, lower body weight, hypogonadism, use of antipsychotic medications, and smoking was found to be associated with osteoporosis.
Malignancy incidence in 5294 patients with juvenile arthritis
Authors: Zahedi Niaki Omid , Clarke Ann E , Ramsey-Goldman Rosalind , Yeung Rae , Hayward Kristen , Oen Kiem , Duffy Ciarán M , Rosenberg Alan , O'Neil Kathleen M , von Scheven Emily , Schanberg Laura , Labrecque Jeremy , Tse Shirley M L , Hasija Rachana , Lee Jennifer L F , Bernatsky Sasha
Published: May 2016

Objective

To determine cancer incidence in a large clinical juvenile-onset arthritis population.

Methods

We combined data from 6 existing North American juvenile-onset arthritis cohorts. Patients with juvenile-onset arthritis were linked to regional cancer registries to detect incident cancers after cohort entry, defined as first date seen in the paediatric rheumatology clinic. The expected number of malignancies was obtained by multiplying the person-years observed (defined from cohort entry to end of follow-up) by the geographically matched age, sex and calendar year-specific cancer rates. The standardised incidence ratios (SIR; ratio of cancers observed to expected) were generated, with 95% CIs.

Results

The 6 juvenile arthritis registries provided a total of 5294 patients. The mean age at cohort entry was 8.9 (SD 5.0) years and 68% of participants were female. The mean duration of follow-up was 6.8 years with a total of 36 063 person-years spanning 1978–2012. During follow-up, 9 invasive cancers occurred, compared with 10.9 expected (SIR 0.82, 95% CI 0.38 to 1.5). 3 of these were haematological (Hodgkin's, non-Hodgkin's lymphoma and leukaemia). 6 of the patients with cancer were exposed to disease-modifying drugs; 5 of these had also been exposed to biological agents.

Conclusions

We did not clearly demonstrate an increase in overall malignancy risk in patients with juvenile-onset arthritis followed for an average of almost 7 years. 3 of the 9 observed cancers were haematological. 5 of the cancers arose in children exposed to biological agents. Longer follow-up of this population is warranted, with further study of drug effects.
Light-intensity and high-intensity interval training improve cardiometabolic health in rats
Authors: Batacan Romeo B. , Duncan Mitch J. , Dalbo Vincent J. , Connolly Kylie J. , Fenning Andrew S.
Published: May 2016

Physical activity has the potential to reduce cardiometabolic risk factors but evaluation of different intensities of physical activity and the mechanisms behind their health effects still need to be fully established. This study examined the effects of sedentary behaviour, light-intensity training, and high-intensity interval training on biometric indices, glucose and lipid metabolism, inflammatory and oxidative stress markers, and vascular and cardiac function in adult rats. Rats (12 weeks old) were randomly assigned to 1 of 4 groups: control (CTL; no exercise), sedentary (SED; no exercise and housed in small cages to reduce activity), light-intensity trained (LIT; four 30-min exercise bouts/day at 8 m/min separated by 2-h rest period, 5 days/week), and high-intensity interval trained (HIIT, four 2.5-min work bouts/day at 50 m/min separated by 3-min rest periods, 5 days/week). After 12 weeks of intervention, SED had greater visceral fat accumulation (p < 0.01) and slower cardiac conduction (p = 0.04) compared with the CTL group. LIT and HIIT demonstrated beneficial changes in body weight, visceral and epididymal fat weight, glucose regulation, low-density lipoprotein cholesterol, total cholesterol, and mesenteric vessel contractile response compared with the CTL group (p < 0.05). LIT had significant improvements in insulin sensitivity and cardiac conduction compared with the CTL and SED groups whilst HIIT had significant improvements in systolic blood pressure and endothelium-independent vasodilation to aorta and mesenteric artery compared with the CTL group (p < 0.05). LIT and HIIT induce health benefits by improving traditional cardiometabolic risk factors. LIT improves cardiac health while HIIT promotes improvements in vascular health.
RecQL4 regulates autophagy and apoptosis in U2OS cells
Authors: Duan Yangmiao , Fang Hongbo
Published: May 2016

RecQL4, one of the 5 human RecQ helicases, is a key mediator of genomic stability and its deficiency can cause premature aging phenotypes. Here, by using CRISPR/Cas and RNAi technology, we demonstrated that autophagy level was elevated in both RecQL4 knockdown and knockout cells compared with those of the control cells. Surprisingly, mitochondrial content was increased and LC3 co-localization with mitochondria was partially lost in RecQL4 knockout cells compared with the control cells, suggesting that RecQL4 deficiency impaired mitophagic processes in U2OS cells. Furthermore, we found that knockout of RecQL4 destabilized PINK1. In addition, RecQL4 knockout cells were more susceptible to apoptosis under mitochondrial stress than the control cells. In conclusion, our findings indicated a novel role of RecQL4 in the regulation of autophagy/mitophagy in U2OS cells.
Single dose and repeated administrations of liraglutide alter energy metabolism in the brains of young and adult rats
Authors: Prá Morgana , Ferreira Gabriela Kozuchovski , de Mello Aline Haas , Schraiber Rosiane de Bona , Cardoso Larissa Colonetti , Souza Luana da Rosa , da Rosa Naiana , Fortunato Jucélia Jeremias , Rezin Gislaine Tezza
Published: May 2016

Liraglutide is a human glucagon-like peptide-1 (GLP-1) analogue that was recently approved to treat obesity in some countries. Considering that liraglutide effects on brain energy metabolism are little known, we evaluated the effects of liraglutide on the energy metabolism. Animals received a single or daily injection of saline or liraglutide during 7 days (25, 50, 100, or 300 μg/kg i.p.). Twenty-four hours after the single or last injection, the rats were euthanized and the hypothalamus, prefrontal cortex, cerebellum, hippocampus, striatum, and posterior cortex were isolated. Our results demonstrated that a single dose of liraglutide in young rats increased the activity of complexes and inhibited creatine kinase activity. Repeated administrations of liraglutide in young rats reduced the activity of complexes and activated creatine kinase activity. In adult rats, a single dose of liraglutide reduced the activity of complex I and creatine kinase and increased the activity of complexes II and IV. Repeated administrations of liraglutide in adult rats increased the activity of complexes I and IV and reduced the activity of complex II and creatine kinase. We concluded that liraglutide may interfere in energy metabolism, because analysis of different times of administrations, concentrations, and level of brain development leads to divergent results.
Methane and nitrous oxide emissions from Canadian dairy farms and mitigation options: An updated review
Authors: Jayasundara Susantha , Ranga Niroshan Appuhamy J.A.D. , Kebreab Ermias , Wagner-Riddle Claudia
Published: May 2016

This review examined methane (CH4) and nitrous oxide (N2O) mitigation strategies for Canadian dairy farms. The primary focus was research conducted in Canada and cold climatic regions with similar dairy systems. Meta-analyses were conducted to assess the impact of a given strategy when sufficient data were available. Results indicated that options to reduce enteric CH4from dairy cows were increasing the dietary starch content and dietary lipid supplementation. Replacing barley or alfalfa silage with corn silage with higher starch content decreased enteric CH4per unit of milk by 6%. Increasing dietary lipids from 3% to 6% of dry matter (DM) reduced enteric CH4yield by 9%. Strategies such as nitrate supplementation and 3-nitrooxypropanol additive indicated potential for reducing enteric CH4by about 30% but require extensive research on toxicology and consumer acceptance. Strategies to reduce emissions from manure are anaerobic digestion, composting, solid–liquid separation, covering slurry storage and flaring CH4, and reducing methanogen inoculum by complete emptying of slurry storage at spring application. These strategies have potential to reduce emissions from manure by up to 50%. An integrated approach of combining strategies through diet and manure management is necessary for significant GHG mitigation and lowering carbon footprint of milk produced in Canada.
Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins
Authors: Karson Jeffrey A.
Published: May 2016

Rifting near hotspots results in mantle melting to create thick mafic igneous crust at volcanic rifted margins (VRMs). This mafic crust is transitional between rifted continental crust with mafic intrusions landward and oceanic crust into which it grades seaward. Seismic velocities, crustal drilling, and exhumed margins show that the upper crust in these areas is composed of basaltic lava erupted in subaerial to submarine conditions intruded by downward increasing proportions of dikes and sparse gabbroic intrusions. The lower crust of these regions is not exposed but is inferred from seismic velocities (Vp > 6.5 km/sec) and petrological constraints to be gabbroic to ultramafic in composition. Limited access to crustal sections generated along VRMs have raised questions regarding the composition and structure of this transitional crust and how it evolves during the early stages of rifting and subsequent seafloor spreading. Active processes in Iceland provide a glimpse of subaerial spreading with the creation of a thick (40–25 km) mafic igneous crust that may be analogous to the transitional crust of VRMs. Segmented rift zones that propagate away from the Iceland hotspot, migrating transform fault zones, and rift-parallel strike-slip faults create a complex plate boundary zone in the upper, brittle crust. These structures may be decoupled from underlying lower crustal gabbroic rocks that are capable of along-axis flow that smooths-out crustal thickness variations. Similar processes may be characteristic of the early history of VRMs and volcanic hotspot ridges related to rifting and seafloor spreading proximal to hotspots.
On the arc index of cable links and Whitehead doubles
Authors: Lee Hwa Jeong , Takioka Hideo
Published: May 2016

In this paper, we construct an algorithm to produce canonical grid diagrams of cable links and Whitehead doubles, which give sharper upper bounds of the arc index of them. Moreover, we determine the arc index of [Formula: see text]-cable links and Whitehead doubles of all prime knots with up to eight crossings.
Classifying links under fused isotopy
Authors: Fish Andrew , Keyman Ebru
Published: May 2016

All knots have been shown to be isotopic to the unknot using a process known as virtualization. We extend and adapt this process to show that, up to fused isotopy, classical links are classified by their linking numbers. We provide an algebraic proof, utilizing Alexander’s Theorem and some simple results about the pure braid group.
Is classical flat Kasner spacetime flat in quantum gravity?
Authors: Singh Parampreet
Published: May 2016

Quantum nature of classical flat Kasner spacetime is studied using effective spacetime description in loop quantum cosmology (LQC). We find that even though the spacetime curvature vanishes at the classical level, nontrivial quantum gravitational effects can arise. For the standard loop quantization of Bianchi-I spacetime, which uniquely yields universal bounds on expansion and shear scalars and results in a generic resolution of strong singularities, we find that a flat Kasner metric is not a physical solution of the effective spacetime description, except in a limit. The lack of a flat Kasner metric at the quantum level results from a novel feature of the loop quantum Bianchi-I spacetime: quantum geometry induces nonvanishing spacetime curvature components, making it not Ricci flat even when no matter is present. The noncurvature singularity of the classical flat Kasner spacetime is avoided, and the effective spacetime transits from a flat Kasner spacetime in asymptotic future, to a Minkowski spacetime in asymptotic past. Interestingly, for an alternate loop quantization which does not share some of the fine features of the standard quantization, flat Kasner spacetime with expected classical features exists. In this case, even with nontrivial quantum geometric effects, the spacetime curvature vanishes. These examples show that the character of even a flat classical vacuum spacetime can alter in a fundamental way in quantum gravity and is sensitive to the quantization procedure.
Light bending in f(T) gravity
Authors: Ruggiero Matteo Luca
Published: May 2016

In the framework of [Formula: see text] gravity, we focus on a weak-field and spherically symmetric solution for the Lagrangian [Formula: see text], where [Formula: see text] is a small constant which parametrizes the departure from general relativity (GR). In particular, we study the propagation of light and obtain the correction to the general relativistic bending angle. Moreover, we discuss the impact of this correction on some gravitational lensing observables, and evaluate the possibility of constraining the theory parameter [Formula: see text] by means of observations. In particular, on taking into account the astrometric accuracy in the Solar System, we obtain that [Formula: see text]; this bound is looser than those deriving from the analysis of Solar System dynamics, e.g. [Formula: see text] [L. Iorio, N. Radicella and M. L. Ruggiero, J. Cosmol. Astropart. Phys. 1508 (2015) 021, arXiv:1505.06996 [gr-qc].], [Formula: see text] [L. Iorio and E. N. Saridakis, Mon. Not. R. Astron. Soc. 427 (2012) 1555, arXiv:1203.5781 [gr-qc].] or [Formula: see text] [Y. Xie and X. M. Deng, Mon. Not. R. Astron. Soc. 433 (2013) 3584, arXiv:1312.4103 [gr-qc].]. However, we suggest that, since the effect only depends on the impact parameter, better constraints could be obtained by studying light bending from planetary objects.
IONIC LIQUID ASSISTED ACETYLENE PARTIAL HYDROGENATION OVER SURFACE OF PALLADIUM NANOPARTICLES
Authors: FARSHIDFAR FARSHAD , KAZEMZAD MAHMOOD , KHANLARKHANI ALI , REZAEI MEHRAN
Published: May 2016

The loss of acetylene partial hydrogenation selectivity over bare palladium catalyst is observed by aging. In this study, 1-butyl-3-methyl imidazolinium hydroxide ionic liquid (BMIm[OH]) is loaded on Pd/[Formula: see text]–Al2O3 solid catalyst for enhancing the selectivity and different experimental techniques such as surface area measurements and catalytic performance have been performed to characterize the modified catalyst. Results revealed that the addition of ionic liquid maintains higher selectivity of partial hydrogenation over Pd/[Formula: see text]–Al2O3 catalyst for more than 30[Formula: see text]h especially at the temperature of acetylene complete removal ([Formula: see text]C). The activation energies of partial and complete acetylene hydrogenation on bare and ionic liquid loaded Pd/[Formula: see text]–Al2O3 are also calculated and utilized to clarify the obtained results.
The group of automorphisms of the Lie algebra of derivations of a polynomial algebra
Authors: Bavula V. V.
Published: May 2016

A short proof is given of Rudakov’s result (announced in [A. N. Rudakov, Subalgebras and automorphisms of Lie algebras of Cartan type, Funktsional. Anal. i Prilozhen. 20(1) (1986) 83–84]), that the group of automorphisms of the Lie algebra [Formula: see text] of derivations of a polynomial algebra [Formula: see text], over a field of characteristic zero is canonically isomorphic to the group of automorphisms of the polynomial algebra [Formula: see text].
Functions of the infinitesimal generator of a strongly continuous quaternionic group
Authors: Alpay Daniel , Colombo Fabrizio , Gantner Jonathan , Kimsey David P.
Published: May 2016

The quaternionic analogue of the Riesz–Dunford functional calculus and the theory of semigroups and groups of linear quaternionic operators have recently been introduced and studied. In this paper, we suppose that [Formula: see text] is the quaternionic infinitesimal generator of a strongly continuous group of operators [Formula: see text] and we show how we can define bounded operators [Formula: see text], where [Formula: see text] belongs to a class of functions that is larger than the one to which the quaternionic functional calculus applies, using the quaternionic Laplace–Stieltjes transform. This class includes functions that are slice regular on the [Formula: see text]-spectrum of [Formula: see text] but not necessarily at infinity. Moreover, we establish the relation between [Formula: see text] and the quaternionic functional calculus and we study the problem of finding the inverse of [Formula: see text].