bluuebunny/crossref_metadata_2025 huggingface dataset:
When Birds of a Feather Don't Flock Together: A Macrostructural Approach to Interracial Crime
Authors: Kim Sangmoon , Willis Cecil L. , Latterner Keely , LaGrange Randy
Published: February 2016

The greater prevalence of intraracial crime to interracial crime is a common finding in criminology. This issue is best understood when specific crimes are studied from a proper theoretical basis. We argue that variation in rates of cross‐racial crime is explained by homophily bias, reflected in residential segregation, in conjunction with the motivational mindset of an offender, specifically whether a crime is instrumental or expressive in nature. We hypothesize that homophily bias is stronger in expressive crimes than it is in instrumental crimes. Using the National Incident‐Based Reporting System (NIBRS) for 2009 and 2010, we analyze robbery and aggravated assault as instrumental and expressive crimes, respectively. The analyses show that racial residential segregation increases, as expected, the relative frequency of black intraracial assault to black interracial assault, whereas it does not affect the relative frequency in robbery. Contrary to our hypothesis, however, the same variable shows little effect on the relative frequency of white intraracial to interracial assault. We give possible explanations as to why white crimes are insensitive to residential segregation.
Entrepreneurship of Women in the Rural Space in Israel: Catalysts and Obstacles to Enterprise Development
Authors: Sofer Michael , Saada M.A. Tzipi
Published: February 2016

This article examines 100 women and their enterprises in moshav‐type co‐operative rural settlements in the rural‐urban fringe of Tel‐Aviv metropolitan area, Israel, and analyses the catalysts and obstacles to development and expansion of such enterprises. Most of the businesses are small, in the personal and service sector, and based on experience in past employment. The majority are located in homes or unused farming structures and constitute the major source of household income. Major catalysts of development include the search for alternatives to waning farming income, self‐fulfilment, and professional development; main obstacles are shortage of capital and lack of self‐confidence in the ability to manage a business. The location is advantageous for fulfilling family obligations and saving costs, but problematic because of distance from central markets and intense local competition. The businesses play a crucial role in the survival strategy of rural households and help improve the quality of life and wellbeing in the region.
Evolution of human cytomegalovirus‐seronegative donor/‐seropositive recipient high‐risk combination frequency in allogeneic hematopoietic stem cell transplantations at Institute of Hematology and Blood Transfusion during 1995–2014
Authors: Nemeckova S. , Sroller V. , Stastna‐Markova M.
Published: February 2016

Background

Human cytomegalovirus (HCMV) establishes lifelong latent infection that can result in severe life‐threatening disease in immunosuppressed patients after hematopoietic stem cell transplantation (HSCT). An HCMV‐seropositive transplant recipient who receives a graft from a seronegative donor (R+/D−) is at high risk of recurrent HCMV reactivation.

Methods

To assess the incidence of R+/D− combination, we retrospectively evaluated HCMV‐seronegative donors for 746 allogeneic HSCT treatments carried out at our center during 1995–2014. In our cohort, 20% HCMV‐seronegative HSCT recipients, 21% HCMV‐seronegative related graft donors, and 52% HCMV‐seronegative unrelated graft donors were included.

Results

Analyses of the HCMV serostatus of hematopoietic stem cell donors during 2 consecutive calendar periods (1995–2005 and 2006–2014) showed a significant increase in the proportion of seronegative donors (odds ratio [OR] = 1.947). In addition, the number of HSCT treatments using an unrelated donor increased (OR = 2.376). Finally, the use of grafts from countries with a very low HCMV prevalence increased.

Conclusion

This increase in HCMV seronegativity in unrelated donors and the increased proportion of unrelated donors were responsible for the increased occurrence of the high‐risk combination R+/D− (OR = 1.680). If the reduction in the rate of HCMV‐seropositive graft donors continues, an increased frequency of HCMV reactivation events in our transplant recipients can be expected, because of the increasing occurrence of the high‐risk R+/D− combination.
Mitochondrial ORF79 levels determine pollen abortion in cytoplasmic male sterile rice
Authors: Kazama Tomohiko , Itabashi Etsuko , Fujii Shinya , Nakamura Takahiro , Toriyama Kinya
Published: February 2016

Cytoplasmic male sterility (CMS) is an important agricultural trait characterized by lack of functional pollen, and caused by ectopic and defective mitochondrial gene expression. The pollen function in CMS plants is restored by the presence of nuclear‐encoded restorer of fertility (Rf) genes. Previously, we cloned Rf2, which restores the fertility of Lead Rice (LD)‐type CMS rice. However, neither the function of Rf2 nor the identity of the mitochondrial gene causing CMS has been determined in LD–CMS rice. Here, we show that the mitochondrial gene orf79 acts as a CMS‐associated gene in LD–CMS rice, similar to its role in BT–CMS rice originating from Chinsurah Boro II, and Rf2 weakly restores fertility in BT–CMS rice. We also show that RF2 promotes degradation of atp6–orf79 RNA in a different manner from that of RF1, which is the Rf gene product in BT–CMS rice. The amount of ORF79 protein in LD–CMS rice was one‐twentieth of the amount in BT–CMS rice. The difference in ORF79 protein levels probably accounts for the mild and severe pollen defects in LD–CMS and BT–CMS rice, respectively. In the presence of Rf2, accumulation of ORF79 was reduced to almost zero and 25% in LD–CMS and BT–CMS rice, respectively, which probably accounts for the complete and weak fertility restoration abilities of Rf2 in LD–CMS and BT–CMS rice, respectively. These observations indicate that the amount of ORF79 influences the pollen fertility in two strains of rice in which CMS is induced by orf79.
Transfusion of recently donated (fresh) red blood cells (RBCs) does not improve survival in comparison with current practice, while safety of the oldest stored units is yet to be established: a meta‐analysis
Authors: Remy K. E. , Sun J. , Wang D. , Welsh J. , Solomon S. B. , Klein H. G. , Natanson C. , Cortés‐Puch I.
Published: February 2016

Background and Objectives

Preclinical studies generated the hypothesis that older stored red blood cells (RBCs) can increase transfusion risks. To examine the most updated and complete clinical evidence and compare results between two trial designs, we assessed both observational studies and randomized controlled trials (RCTs) studying the effect of RBC storage age on mortality.

Materials and Methods

Five databases were searched through December 2014 for studies comparing mortality using transfused RBCs having longer and shorter storage times.

Results

Analysis of six RCTs found no significant differences in survival comparing current practice (average storage age of 2 to 3 weeks) to transfusion of 1‐ to 10‐day‐old RBCs (OR 0·91, 95% CI 0·77‐1·07). RBC storage age was lower in RCTs vs. observational studies (P = 0·01). The 31 observational studies found an increased risk of death (OR 1·13, 95% CI 1·03–1·24) (P = 0·01) with increasing age of RBCs, a different mortality effect than RCTs (P = 0·02).

Conclusion

RCTs established that transfusion of 1‐ to 10‐day‐old stored RBCs is not superior to current practice. The apparent discrepancy in mortality between analyses of RCTs and observational studies may in part relate to differences in hypotheses tested and ages of stored RBCs studied. Further trials investigating 1‐ to 10‐day‐old stored RBC benefits would seem of lower priority than studies to determine whether 4‐ to 6‐week stored units have safety and efficacy equivalent to the 2‐ to 3‐week‐old stored RBCs commonly transfused today.
Structural studies of the C‐terminal tail of polycystin‐2 (PC2) reveal insights into the mechanisms used for the functional regulation of PC2
Authors: Yang Yifei , Ehrlich Barbara E.
Published: February 2016

Mutations in polycystin‐2 (PC2) lead to autosomal dominant polycystic kidney disease (ADPKD). The molecular mechanism linking mutations in PC2 and the pathogenesis of ADPKD is not well understood. Therefore, understanding the functional regulation of PC2 and its interaction with other proteins under both physiological and pathogenic conditions is important for elucidating the disease mechanism and identifying potential molecular targets for treatment. Normally, PC2 functions as a calcium‐permeable channel whose activity is regulated by calcium binding to the C‐terminal domain of PC2 (PC2 Cterm). The PC2 Cterm is also involved in the PC2 channel assembly and hetero‐oligomerization with other binding partners in cells. Different functional domains of the PC2 Cterm have been studied using structural approaches. Within the PC2 Cterm, there is a calcium‐binding EF‐hand domain, crucial for the calcium‐dependent activity of the PC2 channel. Downstream of the EF‐hand domain lies a coiled‐coil region, which is involved in the assembly and hetero‐interaction of the PC2 protein. The PC2 Cterm can form an oligomer, mediated by the coiled‐coil region. Although PC2 Cterm has been extensively studied for its relationship with ADPKD and its importance in PC2 regulation, there are misunderstandings with respect to the definition of the domain topology within the PC2 Cterm and the functional role of each domain. Here, we review previous studies that connect the molecular properties of the domains of PC2 Cterm to distinct aspects of PC2 functions and regulation.

image
Turbine Platform Cooling and Blade Suction Surface Phantom Cooling From Simulated Swirl Purge Flow
Authors: Li Shiou-Jiuan , Lee Jiyeon , Han Je-Chin , Zhang Luzeng , Moon Hee-Koo
Published: February 2016

This paper presents the swirl purge flow on a platform and a modeled land-based turbine rotor blade suction surface. Pressure-sensitive paint (PSP) mass transfer technique provides detailed film-cooling effectiveness distribution on the platform and phantom cooling effectiveness on the blade suction surface. Experiments were conducted in a low-speed wind tunnel facility with a five-blade linear cascade. The inlet Reynolds number based on the chord length is 250,000. Swirl purge flow is simulated by coolant injection through 50 inclined cylindrical holes ahead of the blade leading edge row. Coolant injections from cylindrical holes pass through nozzle endwall and a dolphin nose axisymmetric contour before reaching the platform and blade suction surface. Different “coolant injection angles” and “coolant injection velocity to cascade inlet velocity” result in various swirl ratios to simulate real engine conditions. Simulated swirl purge flow uses coolant injection angles of 30 deg, 45 deg, and 60 deg to produce swirl ratios of 0.4, 0.6, and 0.8, respectively. Traditional purge flow has a coolant injection angle of 90 deg to generate swirl ratio of 1. Coolant to mainstream mass flow rate (MFR) ratio is 0.5%, 1.0%, and 1.5% for all the swirl ratios. Coolant to mainstream density ratio maintains at 1.5 to match engine conditions. Most of the swirl purge and purge coolant approach the platform; however, a small amount of the coolant migrates to the blade suction surface. Swirl ratio of 0.4 has the highest relative motion between rotor and coolant and severely decreases film cooling and phantom cooling effectiveness. Higher MFR of 1% and 1.5% cases suffers from apparent decrement of the effectiveness while increasing relative motion.
The benefit of head orientation to speech intelligibility in noise
Authors: Grange Jacques A. , Culling John F.
Published: February 2016

Spatial release from masking is traditionally measured with speech in front. The effect of head-orientation with respect to the speech direction has rarely been studied. Speech-reception thresholds (SRTs) were measured for eight head orientations and four spatial configurations. Benefits of head orientation away from the speech source of up to 8 dB were measured. These correlated with predictions of a model based on better-ear listening and binaural unmasking (r = 0.96). Use of spontaneous head orientations was measured when listeners attended to long speech clips of gradually diminishing speech-to-noise ratio in a sound-deadened room. Speech was presented from the loudspeaker that initially faced the listener and noise from one of four other locations. In an undirected paradigm, listeners spontaneously turned their heads away from the speech in 56% of trials. When instructed to rotate their heads in the diminishing speech-to-noise ratio, all listeners turned away from the speech and reached head orientations associated with lower SRTs. Head orientation may prove valuable for hearing-impaired listeners.
Relevance of Damped Harmonic Oscillation for Modeling the Training Effects on Daily Physical Performance Capacity in Team Sport
Authors: Morin Stéphane , Ahmaïdi Saïd , Leprêtre Pierre-Marie
Published: February 2016

Context:

Positive and negative effects of training induce apparent oscillations of performance, suggesting that the delayed cumulative effects of training on daily performance capacity (DPC) are best fitted by sine waves damped over time.

Purpose:

To compare the criterion validity of the impulse-response (IR) model of Banister et al and the damped harmonic oscillation (DHO) model for quantifying the training load (TL)–DPC relationship.

Methods:

Six female professional volleyball players (20.8 ± 2.4 y) were monitored using the session rating of perceived exertion (sRPE) for 9 mo to quantify TL. Countermovement-jump (CMJ) and 4-step-approach-CMJ (4sCMJ) performances were recorded once a month. Parameters of models were determined by minimizing residual-sum squares between predicted and real performances with a nonlinear regression.

Results:

DPC was best fitted by the DHO model rather than the IR model (CMJ, R2 = .80 ±.08 and.69 ±.20, respectively; 4sCMJ, R2 = .86 ± .09 and .67 ± .29, respectively). The damping parameter θ and the period T were positively correlated with age (ρ = 0.81, P < .05, and ρ = 0.86, P < .02, respectively).

Conclusions:

The DHO model is a useful tool for modeling DPC as the sum of the delayed DPCs from the consecutive training and recovery days. DPC could be considered the expression of the individual process of accumulation and dissipation of fatigue induced by training. DHO-model parameters were correlated with age, which prompts one to postulate that expertise has a major influence on DPC. The DHO model will help coaches develop a greater understanding of training effects and make monitoring of the training process more effective.
Two Weeks of Repeated-Sprint Training in Soccer: To Turn or Not to Turn?
Authors: Taylor Jonathan M. , Macpherson Tom W. , McLaren Shaun J. , Spears Iain , Weston Matthew
Published: February 2016

Purpose:

To compare the effects of 2 repeated-sprint training programs on fitness in soccer.

Methods:

Fifteen semiprofessional soccer players (age: 24 ± 4 y; body mass: 77 ± 8 kg) completed 6 repeated-sprint training sessions over a 2-week period. Players were assigned to a straight-line (STR) (n = 8; 3–4 sets of 7 × 30 m) or change of direction (CoD) (n = 7; 3–4 sets of 7 × 20-m) repeated-sprint training group. Performance measures included 5-, 10-, and 20-m sprints, countermovement jump, Illinois agility, and Yo-Yo Intermittent Recovery Test level 1 (YYIRTL1) performance. Internal (heart rate) and external (global positioning system-derived measures) training loads were monitored throughout. Data were analyzed using magnitude-based inferences.

Results:

Internal and external loads were higher in the STR group than in the CoD group with large differences in maximum velocity (28.7%; ±90% confidence limits, 3.3%), moderate differences in mean heart rates (7.0%; ±1.4%) and PlayerLoad (17.6%; ±8.6%), and small differences in peak heart rates (3.0%; ±1.6%). Large improvements in 5-m (STR: 9.6%; ±7.0% and CoD: 9.4%; ±3.3%), 10-m (STR: 6.6%; ±4.6% and CoD: 6.7%; ±2.2%), and 20-m (STR: 3.6; ±4.0% and CoD: 4.0; ±1.7%) sprints were observed. Large and moderate improvements in YYIRTL1 performance were observed in the STR (24.0%; ±9.3%) and CoD (31.0%; ±7.5%), respectively. Between-groups differences in outcome measures were unclear.

Conclusions:

Two weeks of repeated-sprint training stimulates improvements in acceleration, speed, and high-intensity running performance in soccer players. Despite STR inducing higher internal and external training loads, training adaptations were unclear between training modes, indicating a need for further research.
Energetics of Table Tennis and Table Tennis–Specific Exercise Testing
Authors: Zagatto Alessandro Moura , Leite Jorge Vieira de Mello , Papoti Marcelo , Beneke Ralph
Published: February 2016

Purpose:

To test the hypotheses that the metabolic profile of table tennis is dominantly aerobic, anaerobic energy is related to the accumulated duration and intensity of rallies, and activity and metabolic profile are interrelated with the individual fitness profile determined via table tennis–specific tests.

Methods:

Eleven male experienced table tennis players (22 ± 3 y, 77.6 ± 18.9 kg, 177.1 ± 8.1 cm) underwent 2 simulated table tennis matches to analyze aerobic (WOXID) energy, anaerobic glycolytic (WBLC) energy, and phosphocreatine breakdown (WPCr); a table tennis–specific graded exercise test to measure ventilatory threshold and peak oxygen uptake; and an exhaustive supramaximal table tennis effort to determine maximal accumulated deficit of oxygen.

Results:

WOXID, WBLC, and WPCr corresponded to 96.5% ± 1.7%, 1.0% ± 0.7%, and 2.5% ± 1.4%, respectively. WOXID was interrelated with rally duration (r = .81) and number of shots per rally (r = .77), whereas match intensity was correlated with WPCr (r = .62) and maximal accumulated oxygen deficit (r = .58).

Conclusions:

The metabolic profile of table tennis is predominantly aerobic and interrelated with the individual fitness profile determined via table tennis–specific tests. Table tennis–specific ventilatory threshold determines the average oxygen uptake and overall WOXID, whereas table tennis–specific maximal accumulated oxygen deficit indicates the ability to use and sustain slightly higher blood lactate concentration and WBLC during the match.
Plasma membrane localization of the μ-opioid receptor controls spatiotemporal signaling
Authors: Halls Michelle L. , Yeatman Holly R. , Nowell Cameron J. , Thompson Georgina L. , Gondin Arisbel Batista , Civciristov Srgjan , Bunnett Nigel W. , Lambert Nevin A. , Poole Daniel P. , Canals Meritxell
Published: February 2016

Differences in plasma membrane mobility or clustering of an opioid receptor may underlie the different effects of its agonists.
Papers of note in
Science
Authors: Gough Nancy R.
Published: February 2016

This week’s articles feature insights into mechanisms that lead to hair loss, a mechanism by which inhibitors work on a mutant enzyme, and a remembrance for Alfred Gilman.
Kinetic Study of Laboratory Mutants of NDM-1 Metallo-β-Lactamase and the Importance of an Isoleucine at Position 35
Authors: Marcoccia Francesca , Bottoni Carlo , Sabatini Alessia , Colapietro Martina , Mercuri Paola Sandra , Galleni Moreno , Kerff Frédéric , Matagne André , Celenza Giuseppe , Amicosante Gianfranco , Perilli Mariagrazia
Published: February 2016

Two laboratory mutants of NDM-1 were generated by replacing the isoleucine at position 35 with threonine and serine residues: the NDM-1
I35T
and NDM-1
I35S
enzymes. These mutants were well characterized, and their kinetic parameters were compared with those of the NDM-1 wild type. The
k
cat
,

K
m

, and
k
cat
/

K
m

values calculated for the two mutants were slightly different from those of the wild-type enzyme. Interestingly, the
k
cat
/

K
m

of NDM-1
I35S
for loracarbef was about 14-fold higher than that of NDM-1. Far-UV circular dichroism (CD) spectra of NDM-1 and NDM-1
I35T
and NDM-1
I35S
enzymes suggest local structural rearrangements in the secondary structure with a marked reduction of α-helix content in the mutants.
VraH Is the Third Component of the Staphylococcus aureus VraDEH System Involved in Gallidermin and Daptomycin Resistance and Pathogenicity
Authors: Popella Peter , Krauss Sophia , Ebner Patrick , Nega Mulugeta , Deibert Julia , Götz Friedrich
Published: February 2016

In bacteria, extracellular signals are transduced into the cell predominantly by two-component systems (TCSs) comprising a regulatory unit triggered by a specific signal. Some of the TCSs control executing units such as ABC transporters involved in antibiotic resistance. For instance, inStaphylococcus aureus, activation of BraSR leads to the upregulation ofvraDEexpression that encodes an ABC transporter playing a role in bacitracin and nisin resistance. In this study, we show that the small staphylococcal transmembrane protein VraH forms, together with VraDE, a three-component system. Although the expression ofvraHin the absence ofvraDEwas sufficient to mediate low-level resistance, only this VraDEH entity conferred high-level resistance against daptomycin and gallidermin. In most staphylococcal genomes,vraHis located immediately downstream ofvraDE, forming an operon, whereas in some species it is localized differently. In an invertebrate infection model, VraDEH significantly enhancedS. aureuspathogenicity. In analogy to the TCS connectors, VraH can be regarded as an ABC connector that modulates the activity of ABC transporters involved in antibiotic resistance.
Lead Selection of a New Aminomethylphenol, JPC-3210, for Malaria Treatment and Prevention
Authors: Chavchich Marina , Birrell Geoffrey W. , Ager Arba L. , MacKenzie Donna O. , Heffernan Gavin D. , Schiehser Guy A. , Jacobus Laura R. , Shanks G. Dennis , Jacobus David P. , Edstein Michael D.
Published: February 2016

Structure-activity relationship studies of trifluoromethyl-substituted pyridine and pyrimidine analogues of 2-aminomethylphenols (JPC-2997, JPC-3186, and JPC-3210) were conducted for preclinical development for malaria treatment and/or prevention. Of these compounds, JPC-3210 [4-(
tert
-butyl)-2-((
tert
-butylamino)methyl)-6-(5-fluoro-6-(trifluoromethyl)pyridin-3-yl)phenol] was selected as the lead compound due to superior
in vitro
antimalarial activity against multidrug-resistant
Plasmodium falciparum
lines, lower
in vitro
cytotoxicity in mammalian cell lines, longer plasma elimination half-life, and greater
in vivo
efficacy against murine malaria.
Enhancing the α-Cyclodextrin Specificity of Cyclodextrin Glycosyltransferase from Paenibacillus macerans by Mutagenesis Masking Subsite −7
Authors: Wang Lei , Duan Xuguo , Wu Jing
Published: February 2016

Cyclodextrin glycosyltransferases (CGTases) (EC 2.4.1.19) catalyze the conversion of starch or starch derivates into mixtures of α-, β-, and γ-cyclodextrins. Because time-consuming and expensive purification procedures hinder the widespread application of single-ingredient cyclodextrins, enzymes with enhanced specificity are needed. In this study, we tested the hypothesis that the α-cyclodextrin selectivity of
Paenibacillus macerans
α-CGTase could be augmented by masking subsite −7 of the active site, blocking the formation of larger cyclodextrins, particularly β-cyclodextrin. Five single mutants and three double mutants designed to remove hydrogen-bonding interactions between the enzyme and substrate at subsite −7 were constructed and characterized in detail. Although the rates of α-cyclodextrin formation varied only modestly, the rate of β-cyclodextrin formation decreased dramatically in these mutants. The increase in α-cyclodextrin selectivity was directly proportional to the increase in the ratio of their
k
cat
values for α- and β-cyclodextrin formation. The R146A/D147P and R146P/D147A double mutants exhibited ratios of α-cyclodextrin to total cyclodextrin production of 75.1% and 76.1%, approximately one-fifth greater than that of the wild-type enzyme (63.2%), without loss of thermostability. Thus, these double mutants may be more suitable for the industrial production of α-cyclodextrin than the wild-type enzyme. The production of β-cyclodextrin by these mutants was almost identical to their production of γ-cyclodextrin, which was unaffected by the mutations in subsite −7, suggesting that subsite −7 was effectively blocked by these mutations. Further increases in α-cyclodextrin selectivity will require identification of the mechanism or mechanisms by which these small quantities of larger cyclodextrins are formed.
Global Transcriptional Regulation of Backbone Genes in Broad-Host-Range Plasmid RA3 from the IncU Group Involves Segregation Protein KorB (ParB Family)
Authors: Kulinska Anna , Godziszewska Jolanta , Wojciechowska Anna , Ludwiczak Marta , Jagura-Burdzy Grazyna
Published: February 2016

The KorB protein of the broad-host-range conjugative plasmid RA3 from the IncU group belongs to the ParB family of plasmid and chromosomal segregation proteins. As a partitioning DNA-binding factor, KorB specifically recognizes a 16-bp palindrome which is an essential motif in the centromere-like sequence
parS
RA3
, forms a segrosome, and together with its partner IncC (ParA family) participates in active DNA segregation ensuring stable plasmid maintenance. Here we show that by binding to this palindromic sequence, KorB also acts as a repressor for the adjacent
mobC
promoter driving expression of the
mobC-nic
operon, which is involved in DNA processing during conjugation. Three other promoters, one buried in the conjugative transfer module and two divergent promoters located at the border between the replication and stability regions, are regulated by KorB binding to additional KorB operators (O
B
s). KorB acts as a repressor at a distance, binding to O
B
s separated from their cognate promoters by between 46 and 1,317 nucleotides. This repressor activity is facilitated by KorB spreading along DNA, since a polymerization-deficient KorB variant with its dimerization and DNA-binding abilities intact is inactive in transcriptional repression. KorB may act as a global regulator of RA3 plasmid functions in
Escherichia coli
, since its overexpression in
trans
negatively interferes with mini-RA3 replication and stable maintenance of RA3.
High-Throughput Single-Cell Cultivation on Microfluidic Streak Plates
Authors: Jiang Cheng-Ying , Dong Libing , Zhao Jian-Kang , Hu Xiaofang , Shen Chaohua , Qiao Yuxin , Zhang Xinyue , Wang Yapei , Ismagilov Rustem F. , Liu Shuang-Jiang , Du Wenbin
Published: February 2016

This paper describes the microfluidic streak plate (MSP), a facile method for high-throughput microbial cell separation and cultivation in nanoliter sessile droplets. The MSP method builds upon the conventional streak plate technique by using microfluidic devices to generate nanoliter droplets that can be streaked manually or robotically onto petri dishes prefilled with carrier oil for cultivation of single cells. In addition, chemical gradients could be encoded in the droplet array for comprehensive dose-response analysis. The MSP method was validated by using single-cell isolation of
Escherichia coli
and antimicrobial susceptibility testing of
Pseudomonas aeruginosa
PAO1. The robustness of the MSP work flow was demonstrated by cultivating a soil community that degrades polycyclic aromatic hydrocarbons. Cultivation in droplets enabled detection of the richest species diversity with better coverage of rare species. Moreover, isolation and cultivation of bacterial strains by MSP led to the discovery of several species with high degradation efficiency, including four
Mycobacterium
isolates and a previously unknown fluoranthene-degrading
Blastococcus
species.
Biofilm and Planktonic Bacterial and Fungal Communities Transforming High-Molecular-Weight Polycyclic Aromatic Hydrocarbons
Authors: Folwell Benjamin D. , McGenity Terry J. , Whitby Corinne
Published: February 2016

High-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs) are natural components of fossil fuels that are carcinogenic and persistent in the environment, particularly in oil sands process-affected water (OSPW). Their hydrophobicity and tendency to adsorb to organic matter result in low bioavailability and high recalcitrance to degradation. Despite the importance of microbes for environmental remediation, little is known about those involved in HMW-PAH transformations. Here, we investigated the transformation of HMW-PAHs using samples of OSPW and compared the bacterial and fungal community compositions attached to hydrophobic filters and in suspension. It was anticipated that the hydrophobic filters with sorbed HMW-PAHs would select for microbes that specialize in adhesion. Over 33 days, more pyrene was removed (75% ± 11.7%) than the five-ring PAHs benzo[
a
]pyrene (44% ± 13.6%) and benzo[
b
]fluoranthene (41% ± 12.6%). For both bacteria and fungi, the addition of PAHs led to a shift in community composition, but thereafter the major factor determining the fungal community composition was whether it was in the planktonic phase or attached to filters. In contrast, the major determinant of the bacterial community composition was the nature of the PAH serving as the carbon source. The main bacteria enriched by HMW-PAHs were
Pseudomonas
,
Bacillus
, and
Microbacterium
species. This report demonstrates that OSPW harbors microbial communities with the capacity to transform HMW-PAHs. Furthermore, the provision of suitable surfaces that encourage PAH sorption and microbial adhesion select for different fungal and bacterial species with the potential for HMW-PAH degradation.
Host Plant Determines the Population Size of an Obligate Symbiont (Buchnera aphidicola) in Aphids
Authors: Zhang Yuan-Chen , Cao Wen-Jie , Zhong Le-Rong , Godfray H. Charles J. , Liu Xiang-Dong
Published: February 2016

Buchnera aphidicola
is an obligate endosymbiont that provides aphids with several essential nutrients. Though much is known about aphid-
Buchnera
interactions, the effect of the host plant on
Buchnera
population size remains unclear. Here we used quantitative PCR (qPCR) techniques to explore the effects of the host plant on
Buchnera
densities in the cotton-melon aphid,
Aphis gossypii
.
Buchnera
titers were significantly higher in populations that had been reared on cucumber for over 10 years than in populations maintained on cotton for a similar length of time. Aphids collected in the wild from hibiscus and zucchini harbored more
Buchnera
symbionts than those collected from cucumber and cotton. The effect of aphid genotype on the population size of
Buchnera
depended on the host plant upon which they fed. When aphids from populations maintained on cucumber or cotton were transferred to novel host plants, host survival and
Buchnera
population size fluctuated markedly for the first two generations before becoming relatively stable in the third and later generations. Host plant extracts from cucumber, pumpkin, zucchini, and cowpea added to artificial diets led to a significant increase in
Buchnera
titers in the aphids from the population reared on cotton, while plant extracts from cotton and zucchini led to a decrease in
Buchnera
titers in the aphids reared on cucumber. Gossypol, a secondary metabolite from cotton, suppressed
Buchnera
populations in populations from both cotton and cucumber, while cucurbitacin from cucurbit plants led to higher densities. Together, the results suggest that host plants influence
Buchnera
population processes and that this may provide phenotypic plasticity in host plant use for clonal aphids.
XoxF Acts as the Predominant Methanol Dehydrogenase in the Type I Methanotroph Methylomicrobium buryatense
Authors: Chu Frances , Lidstrom Mary E.
Published: February 2016

Many methylotrophic taxa harbor two distinct methanol dehydrogenase (MDH) systems for oxidizing methanol to formaldehyde: the well-studied calcium-dependent MxaFI type and the more recently discovered lanthanide-containing XoxF type. MxaFI has traditionally been accepted as the major functional MDH in bacteria that contain both enzymes. However, in this study, we present evidence that, in a type I methanotroph,
Methylomicrobium buryatense
, XoxF is likely the primary functional MDH in the environment. The addition of lanthanides increases
xoxF
expression and greatly reduces
mxa
expression, even under conditions in which calcium concentrations are almost 100-fold higher than lanthanide concentrations. Mutations in genes encoding the MDH enzymes validate our finding that XoxF is the major functional MDH, as XoxF mutants grow more poorly than MxaFI mutants under unfavorable culturing conditions. In addition, mutant and transcriptional analyses demonstrate that the lanthanide-dependent MDH switch operating in methanotrophs is mediated in part by the orphan response regulator MxaB, whose gene transcription is itself lanthanide responsive.

IMPORTANCE
Aerobic methanotrophs, bacteria that oxidize methane for carbon and energy, require a methanol dehydrogenase enzyme to convert methanol into formaldehyde. The calcium-dependent enzyme MxaFI has been thought to primarily carry out methanol oxidation in methanotrophs. Recently, it was discovered that XoxF, a lanthanide-containing enzyme present in most methanotrophs, can also oxidize methanol. In a methanotroph with both MxaFI and XoxF, we demonstrate that lanthanides transcriptionally control genes encoding the two methanol dehydrogenases, in part by controlling expression of the response regulator MxaB. Lanthanides are abundant in the Earth's crust, and we demonstrate that micromolar amounts of lanthanides are sufficient to suppress MxaFI expression. Thus, we present evidence that XoxF acts as the predominant methanol dehydrogenase in a methanotroph.
Cenozoic paleogeographic evolution of the Elko Basin and surrounding region, northeast Nevada
Authors: Lundstern J.-E. , Miller E.L. , Grove M. , Hourigan J.K. , Konstantinou A.
Published: February 2016

Geologic mapping, supported by 40Ar/39Ar and U-Pb geochronology and geochemistry of sedimentary and volcanic rocks, reveals the details of the Cenozoic depositional and tectonic history of the eastern Piñon Range and central Huntington Valley in the north-central Basin and Range Province, Nevada (USA). Cretaceous to Miocene supracrustal successions were studied in detail in order to compare the geologic evolution of the upper crust near the Ruby Mountains–East Humboldt Range (RMEH) metamorphic core complex (MCC) with the magmatic, metamorphic, and deformational history of the deep crust in the developing MCC. During the well-documented Late Cretaceous–Oligocene history of partial melting and infrastructure development within the RMEH, surface deposits in Huntington Valley reflect general tectonic quiescence, with evidence for the development of the shallow Elko Basin, minor extension, and eruption of southward-younging ignimbrite flare-up volcanism. Thin, discontinuous successions of Cretaceous–early Cenozoic sedimentary strata were locally blanketed by rhyodacite ignimbrites, domes, and subvolcanic intrusions of the Robinson Mountain volcanic field between 38.5 and 36.8 Ma. This magmatic event represents the first local expression of Cenozoic volcanism linked to the ignimbrite flare-up, and its onset occurred slightly after a renewal of partial melting in the RMEH beginning ca. 42 Ma. The volcanic section was subsequently tilted ∼10°–15° west before ca. 33.9 ± 0.4 Ma. Although melting continued at depth in the RMEH until after 30 Ma, there was no eruption of volcanic rocks after Robinson Mountain volcanism. An additional ≥10°–15° of westward tilting occurred between 31.1 ± 0.3 Ma and ca. 24.4 Ma, as bracketed by the 31 Ma tuff of Hackwood Ranch (which was probably erupted from a distant caldera) and an angular unconformity beneath the overlying Miocene Humboldt Formation. Neither of these tilting events and unconformities appears to represent significant (>∼1 km each) extension, but they could be surface expressions of magmatism, metamorphism, and crustal flow at depth. The Humboldt Formation includes >2000 m of sediment deposited mostly between ca. 16 and 12 Ma, with deposition lasting until at least ca. 8.2 Ma. Humboldt Formation sediments thicken eastward, toward the west-dipping fault that bounds the RMEH, and are interpreted as a basin that developed in the hanging wall of this fault system. Motion on this normal fault system led to the exhumation of metamorphic and igneous rocks of the core complex ∼10 m.y. after the documented cessation of partial melting, high-temperature metamorphism, and intrusion of granitoids into the deep crust ca. 29 Ma. Metamorphic clasts and a detrital zircon signature thought to represent RMEH provenance are first detected in 14.2 Ma or younger sediments.
Low chronic workload and the acute:chronic workload ratio are more predictive of injury than between-match recovery time: a two-season prospective cohort study in elite rugby league players
Authors: Hulin Billy T , Gabbett Tim J , Caputi Peter , Lawson Daniel W , Sampson John A
Published: February 2016

Background

Between-match recovery time, and acute and chronic workloads likely affect subsequent match-injury risk in elite rugby league players.

Methods

Workloads of 28 players throughout two seasons were calculated during short (<7 days), and long (≥7 days) between-match recovery times. ‘Acute’ workloads (1 week) greater than ‘chronic’ workloads (4-week rolling average acute workload) resulted in acute:chronic workload ratios above 1.

Results

No difference was found between the match-injury risk of short and long between-match recovery periods (7.5±2.5% vs 6.8±2.5%). When players had a short recovery between matches, high chronic workloads (18.9–22.0 km) were associated with a smaller risk of match injury than chronic workloads <18.9 km (relative risk (RR) range 0.27–0.32 (CI 0.08 to 0.92); likelihood range 90–95%, likely). Players who had shorter recovery and acute:chronic workload ratios ≥1.6, were 3.4–5.8 times likely to sustain a match injury than players with lower acute:chronic workload ratios (RR range 3.41–5.80 (CI 1.17 to 19.2); likelihood range 96–99%, very likely). Acute:chronic workload ratios between 1.2 and 1.6 during short between-match recovery times demonstrated a greater risk of match injury than ratios between 1.0 and 1.2 (RR=2.88 (CI 0.97 to 8.55); likelihood=92%, likely).

Conclusions

Contrary to the philosophy that high workloads and shorter recovery equate to increased injury risk, our data suggest that high and very-high chronic workloads mayprotectagainst match injury following shorter between-match recovery periods. Acute:chronic workload ratios ∼1.5 are associated with a greater risk of match injury than lower acute:chonic workload ratios. Importantly, workloads can be manipulated to decrease the match-injury risk associated with shorter recovery time between matches.
Effects and dose–response relationships of resistance training on physical performance in youth athletes: a systematic review and meta-analysis
Authors: Lesinski Melanie , Prieske Olaf , Granacher Urs
Published: February 2016

Objectives

To quantify age, sex, sport and training type-specific effects of resistance training on physical performance, and to characterise dose–response relationships of resistance training parameters that could maximise gains in physical performance in youth athletes.

Design

Systematic review and meta-analysis of intervention studies.

Data sources

Studies were identified by systematic literature search in the databases PubMed and Web of Science (1985–2015). Weighted mean standardised mean differences (SMDwm) were calculated using random-effects models.

Eligibility criteria for selecting studies

Only studies with an active control group were included if these investigated the effects of resistance training in youth athletes (6–18 years) and tested at least one physical performance measure.

Results

43 studies met the inclusion criteria. Our analyses revealed moderate effects of resistance training on muscle strength and vertical jump performance (SMDwm0.8–1.09), and small effects on linear sprint, agility and sport-specific performance (SMDwm0.58–0.75). Effects were moderated by sex and resistance training type. Independently computed dose–response relationships for resistance training parameters revealed that a training period of >23 weeks, 5 sets/exercise, 6–8 repetitions/set, a training intensity of 80–89% of 1 repetition maximum (RM), and 3–4 min rest between sets were most effective to improve muscle strength (SMDwm2.09–3.40).

Summary/conclusions

Resistance training is an effective method to enhance muscle strength and jump performance in youth athletes, moderated by sex and resistance training type. Dose–response relationships for key training parameters indicate that youth coaches should primarily implement resistance training programmes with fewer repetitions and higher intensities to improve physical performance measures of youth athletes.
Improving Documentation and Communication Using Operative Note Proformas
Authors: Mahapatra Piyush , ieong edmund
Published: February 2016

Accurate and detailed documentation of surgical procedures is part of good clinical practice, set out by the General Medical Council (GMC). Knee arthroscopy often involves large data sets which require accurate documentation for future assessment and management. This study assesses the quality of documentation of knee arthroscopy, followed by an evaluation of the implementation of a novel operative proforma.

A review of 30 consecutive knee arthroscopy operation notes were analysed for missing information, set against a standardised 30 point criteria. An operation proforma was then introduced, and a further 30 consecutive knee arthroscopy operation notes were analysed. We evaluated allied health professional satisfaction with a Likert point scale survey of 21 allied healthcare professionals (recovery and ward nurses, and physiotherapists) following introduction of the proforma. The mean number of missing items on a 30 point scale was 8.8 (range 0 to 23). Examination under anaesthesia was missed in 43% of cases, tourniquet time in 37% of cases, and wear results in 17% of cases. Following introduction of the proforma, the mean number of missing items was 1.1 (range 0 to 24; p <0.001). This rose to 3.8 after one year (p <0.001) before improvement to 0.7 (p <0.01) with a new and improved proforma. Eighty percent strongly agreed the operation note was clearer, 90% strongly agreed it was more legible, 90% strongly agreed it was more understandable, 50% strongly agreed there was more information recorded, and 100% strongly agreed on the proforma having been improved.

Knee arthroscopy is a common procedure with large data sets, which can often be missed or incomplete. A standardised proforma results in a statistically significant improvement in documentation and reduces the incidence of missing information. They are subjectively clearer, more legible, and generally better compared with handwritten notes. This study demonstrates the improvements in healthcare documentation, both clinically and legally, following introduction of a simple proforma. This concept should be applicable to different specialities and procedures in healthcare.
‘A Friend in the Corner’: supporting people at home in the last year of life via telephone and video consultation—an evaluation
Authors: Middleton-Green L , Gadoud A , Norris B , Sargeant A , Nair S , Wilson L , Livingstone H , Small N
Published: February 2016

Objective

To evaluate ‘Gold Line’, a 24/7, nurse-led telephone and video-consultation support service for patients thought to be in the last year of life in Bradford, Airedale, Wharfedale and Craven.

Method

Data on the time and nature of all calls between 1 April 2014 and 30 March 2015 were obtained from the patient Electronic Records. Interviews with 13 participants captured patients and carers perspectives.

Results

To date, 3291 patients have been referred to the Gold Line. During the study period, 42% of registered patients had a non-cancer diagnosis and 45.2% of service users were not known to Specialist Palliative Care services. The median time on the caseload was 49 days (range 1–504 days). 4533 telephone calls and 573 video consultations were made involving 1813 individuals. 39% of the 5106 contacts were resolved by the Gold Line team without referral to other services. 69% of calls were made outside normal working hours. Interviews with patients and carers reported experiences of support and reassurance from the Gold Line and the importance of practical advice was emphasised. Current data (year to October 2015) show that 98.5% of calls (4500/4568) resulted in patients remaining in their place of residence.

Conclusions

A nurse led, 24/7 telephone and video consultation service can provide valuable support for patients identified to be in the last year of life and for their carers. The line enabled them to feel supported and remain in their place of residence, hence reducing the pressure for avoidable hospital admissions and use of other services. Providing this service may encourage healthcare professionals to identify more patients approaching the last year of life, widening support offered to this group of patients beyond those known to specialist palliative care services.
Prospective, randomised and blinded comparison of proficiency-based progression full-physics virtual reality simulator training versus invasive vascular experience for learning carotid artery angiography by very experienced operators
Authors: Cates Christopher U , Lönn Lars , Gallagher Anthony G
Published: February 2016

Introduction

We assessed the transfer of training (ToT) of virtual reality simulation training compared to invasive vascular experience training for carotid artery angiography (CA) for highly experienced interventionists but new to carotid procedures.

Methods

Prospective, randomised and blinded.

Setting

Catheterisation and skills laboratories in the USA.

Participants

Experienced (mean volume=15 000 cases) interventional cardiologists (n=12) were randomised to train on virtual reality (VR) simulation to a quantitatively defined level of proficiency or to a traditional supervised in vivo patient case training.

Outcome measures

The observed performance differences in performing a CA between two matched groups were then blindly assessed using predefined metrics of performance.

Results

Experienced interventional cardiologists trained on the VR simulator performed significantly better than their equally experienced controls showing a significantly lower rate of objectively assessed intraoperative errors in CA. Performance showed 17–49% ToT from the VR to the in vivo index case.

Discussion

This is the first prospective, randomised and blinded clinical study to report that VR simulation training transfers improved procedural skills to clinical performance on live patients for experienced interventionists. This study, for the first time, demonstrates that VR simulation offers a powerful, safe and effective platform for training interventional skills for highly experienced interventionists with the greatest impact on procedural error reduction.