bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptions of Adverse Work Conditions and Innovative Behavior: The Buffering Roles of Relational Resources
Authors: De Clercq Dirk , Dimov Dimo , Belausteguigoitia Imanol
Published: August 2014

This study investigates how employees’ perceptions of adverse work conditions might discourage innovative behavior and the possible buffering roles of relational resources. Data from a Mexican–based organization reveal that perceptions of work overload negatively affect innovative behavior, but this effect gets attenuated with greater knowledge sharing and interpersonal harmony. Further, although perceived organizational politics lead to lower innovative behavior when relational resources are low, they increase this behavior when resources are high. Organizations which seek to adopt innovative ideas in the presence of adverse work conditions thus should create relational conduits that can mitigate the associated stress.
The Impact of the Oral Proficiency Interview on One Foreign Language Teacher Education Program
Authors: Kissau Scott
Published: August 2014

The Oral Proficiency Interview (OPI) has been increasingly used in academia. However, while multiple studies have documented the growth in OPI implementation across the United States and the proficiency rates of its completers, few have focused specifically on foreign language teacher candidates, and even fewer have investigated the impact that this proficiency assessment may have on language teacher training programs. To better understand the impact of the OPI on foreign language teacher education programs and help guide programmatic decision making, a case study was conducted of one such program that recently implemented the OPI as part of its licensure requirements. The results confirmed earlier research with respect to expected proficiency outcomes of foreign language teacher candidates. The results also suggested that the OPI requirement did not negatively affect program enrollment, nor did teacher trainees negatively perceive the OPI requirement. Finally, the study provided evidence of the positive impact the OPI may have on a foreign language teacher education program. Recommended practices for implementing the OPI in teacher training programs and ways to support foreign language teacher candidates who must complete the assessment are discussed.
Evaluation of a fine sediment biomonitoring tool across a wide range of temperate rivers and streams
Authors: Turley Matt D. , Bilotta Gary S. , Extence Chris A. , Brazier Richard E.
Published: August 2014

Elevated levels of fine sediment (suspended and deposited) are a common cause of ecological degradation in freshwater ecosystems. However, it is time‐consuming and expensive to monitor these parameters to support national and international water resource legislation.

The Proportion of Sediment‐sensitive Invertebrates (PSI) index is a biomonitoring tool that is designed to identify the degree of sedimentation in rivers and streams. Despite having a sound biological basis, until now, the PSI index has only been tested against observed fine sediment data in two catchments; other published applications of the PSI index have relied on inferred fine sediment values.

In this study, we report the results of a comprehensive analysis of the performance of the PSI index across a wide range of reference condition temperate stream and river ecosystems, including 835 sites with data on deposited sediment and 451 sites with data on suspended solids (>12 500 data points measured between 1978 and 2002).

The effect of taxonomic level and taxonomic resolution on the performance of the PSI index was also examined, as was the performance of the PSI index against other non‐sediment‐specific indices, including Average Score Per Taxon (ASPT), Lotic‐invertebrate Index for Flow Evaluation (LIFE), Ephemeroptera, Plecoptera and Trichoptera (EPT) abundance, % EPT abundance, EPT richness and % EPT richness.

The results of this study show that the PSI index was more correlated with fine sediment metrics than the other biological indices tested: rs = −0.64, (P < 0.01, n = 2502) for deposited sediment and rs = −0.50 (P < 0.01, n = 1353) for suspended solids.

We highlight the optimal conditions for applying the PSI index, in its current form. Given the variability in the relationship between PSI and fine sediment metrics, we propose that the use of data from more objective, quantitative methods of measuring deposited fine sediment may help to enhance the performance of the model for future applications and advance understanding of fine sediment dynamics and the pressure–response relationship.
Grazing management and tussock distribution in elephant grass
Authors: Pereira L. E. T. , Paiva A. J. , Geremia E. V. , da Silva S. C.
Published: August 2014

Soil occupation capacity via lateral expansion of tussocks in elephant grass (Pennisetum purpureum Schum.) may be associated with basal tillering. As grazing management alters the proportion of basal and aerial tillers in a tiller population, the hypothesis of this work was that grazing management affects tussock size and distribution with implications for plant population stability. The objective of this study was to evaluate the tiller population stability index, the proportion of basal and aerial tillers, tussock size, and the frequency of tussocks and bare ground in rotationally managed elephant grass cv. Napier. Treatments resulted from the combination of two post‐grazing heights (35 and 45 cm) and two pre‐grazing conditions (95% and maximum canopy light interception during regrowth – LI0·95 and LIMax) and were allocated to experimental units (850 m2 paddocks) according to a 2 × 2 factorial arrangement in a randomized complete block design, with four replications. Measurements were taken from January 2011 to April 2012. The post‐grazing height treatments affected the tiller population stability index, but did not influence the pattern of tussock distribution. On the other hand, the different grazing frequencies (targets of LI pre‐grazing) altered the pattern of tussock distribution and the proportion of bare ground. In general, the tiller population stability index and frequency of tussocks were higher and the frequency of bare ground lower on swards managed with the LI0·95 target relative to those managed with the LIMax target, regardless of the post‐grazing height used, indicating a larger soil occupation capacity of plants under the more frequent defoliation regime. Such responses were associated with larger population of basal tillers and highlight the importance of tiller category and perennation pathway in defining patterns of plant growth and tussock distribution.
Race‐ing, Classing and Gendering Racialized Women's Participation in Entrepreneurship
Authors: Knight Melanie
Published: August 2014

The number of racialized women entrepreneurs has grown exponentially in recent years. Despite this growing trend, these businesswomen are more likely to operate on a small scale; their labour‐intensive businesses are characterized by low profits and limited mobility. Two fields of research attempt to illuminate — albeit problematically — the complexity of this phenomenon. Research on ethnic/immigrant entrepreneurs underestimates the experiences of racialized women who are entrepreneurs in their own right. Meanwhile the literature on women's entrepreneurship essentializes and homogenizes women's entrepreneurship. Research approaching women's entrepreneurship using an intersectional approach is scanty. In this paper, I draw on empirical evidence from a qualitative study with women entrepreneurs of Afro‐Caribbean descent. To provide a more nuanced understanding of racialized women entrepreneurs' experiences as entrepreneurs, I use Dill and Zambrana's intersectional/interlocking systems of oppression framework, examining processes of gendering, classing and racialization within four domains: structural, disciplinary, hegemonic and interpersonal. Despite processes of differentiation, participants found creative and subversive ways to resist these processes.
Role of turmeric in oxidative modulation in end‐stage renal disease patients
Authors: Pakfetrat Maryam , Akmali Masoumeh , Malekmakan Leila , Dabaghimanesh Mojtaba , Khorsand Marjan
Published: August 2014

Oxidative stress is considered as a major player in uremia‐associated morbidity and mortality in hemodialysis (HD) patients. The aim of this study was to evaluate the effects of turmeric on oxidative stress markers in HD patients. This study was a prospective and double‐blind randomized clinical trial. Fifty HD patients aged 18–60 years were recruited after fulfilling the inclusion criteria. Patients were randomly categorized into 2 groups: trial group received turmeric and control group received placebo for 8 weeks. Each patient in the trial group received turmeric, whereas the control group received starch for the same 8 weeks. Plasma malondialdehyde (MDA), red blood cell (RBC) antioxidant enzyme activities as glutathione peroxidase (GPX), glutathione reductase (GR), and catalase (CAT), cholesterol, high‐density lipoprotein‐cholesterol, low‐density lipoprotein‐cholesterol, triglyceride, albumin, and hemoglobin were also measured before and after study. Although MDA level was reduced in both groups, the ratio of decrease was significantly higher in the turmeric group (0.2 vs. 0.1, P = 0.040). Three enzymes of GPX, GR, and CAT levels were increased in both groups; the ratio of increased was significantly higher in the turmeric group for the CAT enzyme (0.73 vs. 0.54; P = 0.02). Also, significant elevation of albumin level in the turmeric group compared with the control group was observed (P = 0.001). Regular ingestion of turmeric reduces plasma MDA and increases RBC CAT activity and plasma albumin levels in HD patients. Turmeric showed no adverse effects.
The effect of infrared stabilisation on B vitamins, phenolics and antioxidants in rice bran
Authors: Yilmaz Neşe , Tuncel Necati Barış
Published: August 2014

The effects of ten successful infrared stabilisation conditions on the content of proximate composition, dietary fibre, phytate, B vitamins, phenolics and antioxidants of rice bran were investigated. The moisture and phytate content significantly decreased in stabilised rice brans while no significant change was observed in crude fat, protein, ash and soluble and insoluble dietary fibre. Among the evaluated B vitamins, solely the content of thiamine was decreased up to 42% while the level of riboflavin, niacin, and total B6 vitamin was not affected from infrared stabilisation (P > 0.05). The insoluble extracts contained more phenolics and antioxidants that did the soluble fractions. The effect of infrared stabilisation on the content of the phenolics and antioxidants in bound extracts was insignificant (P > 0.05). In conclusion, the authors suggest that infrared radiation can be used as a rice bran stabilisation method without causing a significant loss in the nutrients with the exception of thiamine.
Comparing the Trends of Elevated Blood Pressure in Appalachian and Non‐Appalachian Regions
Authors: Shandera‐Ochsner Anne L. , Han Dong Y. , Rose Danny , Aroor Sushanth R. , Schmitt Frederick , Bellamy Lisa M. , Dobbs Michael R.
Published: August 2014

As an established risk factor for cardiovascular disease and stroke, hypertension risks are often thought to be more prevalent in Appalachian mountain ranges when compared with other neighboring counterpart regions. This study evaluated blood pressure (BP) readings among 2358 Kentucky residents attending community stroke risk screening events held in 15 counties, including nine Appalachian counties (n=1134) and six non‐Appalachian counties (n=1224). With high BP being operationally defined as ≥140/90 mm Hg, 41.5% of Appalachian county residents had elevated BP compared with 42.6% among those from non‐Appalachian counties. Although the counties with the highest rates of elevated BP did tend to reside in the Appalachian region, there was no significant difference between rates of elevated BP in Appalachia vs non‐Appalachian counties. This dataset is proposed as a pilot project to encourage further pursuit of a larger controlled project.
Development and application of molecular methods (PCR) for detection of Tasmanian Atlantic salmon reovirus
Authors: Zainathan S C , Carlile G , Carson J , McColl K A , Crane M St. J , Williams L M , Hoad J , Moody N J G , Aiken H M , Browning G F , Nowak B F
Published: August 2014

Molecular (PCR) diagnostic tests for the detection and identification of aquareovirus in general, and Tasmanian Atlantic salmon reovirus (TSRV) specifically, were developed, and their diagnostic sensitivity and specificity were determined and compared with virus isolation in cell culture. Intralaboratory and interlaboratory comparison of PCR (conventional hemi‐nested RT‐PCR & RT‐qPCR) and virus isolation in cell culture using finfish cell lines, CHSE‐214 and EPC, was carried out for the detection and identification of TSRV using field samples of farmed Atlantic salmon Salmo salar, L. from various aquaculture sites around Tasmania. The interlaboratory comparison of diagnostic methods was carried out between two laboratories, AAHL‐CSIRO and DPIPWE‐Tasmania. A total of 144 fish from nine sites (12–33 fish per site) were sampled from two regions of Tasmania (Tamar River estuary in the north and Huon River estuary in the south‐east) during late spring to early summer of 2009, and the data were analysed using different statistical approaches. The prevalence of TSRV ranged from 6% to 22% in both regions. All the diagnostic methods (data from both laboratories) had high specificity, while the estimated sensitivity varied between tests with RT‐qPCR being the most sensitive (95.2%) method followed by virus isolation and then conventional hemi‐nested RT‐PCR.
Equity, Connection, and Engagement in the School Context to Promote Positive Youth Development
Authors: Debnam Katrina J. , Johnson Sarah Lindstrom , Waasdorp Tracy E. , Bradshaw Catherine P.
Published: August 2014

Connection to school and school engagement are important in promoting positive youth development, but little is known about their relationship to school characteristics, particularly school equity. School equity, the extent to which there is fair treatment for all students, is critical for ensuring the success for all students. Hierarchical linear models conducted on data from 19,833 adolescents at 52 high schools indicated that greater school equity was associated with improved student connection to school and school engagement. Cross‐level interactions were observed between equity and the concentration of minority students in the school, as well as for equity and student mobility. Results suggest that improving school equity may be an important contextual target for promoting positive youth development in schools.
Fostering Youth Entrepreneurship: Preliminary Findings From the Young Entrepreneurs Study
Authors: Geldhof G. John , Porter Tenelle , Weiner Michelle B. , Malin Heather , Bronk Kendall C. , Agans Jennifer P. , Mueller Megan , Damon William , Lerner Richard M.
Published: August 2014

Entrepreneurship offers a viable and proven pathway to economic growth and personal fulfillment. However, the number of individuals engaged in entrepreneurial behaviors remains low. This discrepancy between entrepreneurial attitudes and action underscores the need for programs that foster the development of entrepreneurship in today's youth. We argue that a relational developmental systems approach can help researchers understand and facilitate the development of entrepreneurship. In this study, we triangulate across quantitative and qualitative data from the Young Entrepreneurs Study, showing that self‐regulation skills, financial risk tolerance, innovation orientation, and the presence of entrepreneurial adults may be especially important for promoting entrepreneurial intent in older adolescents and young adults. We discuss limitations of the present data set and future directions for research.
The Role of Sociopolitical Attitudes and Civic Education in the Civic Engagement of Black Youth
Authors: Hope Elan C. , Jagers Robert J.
Published: August 2014

Civic engagement is important for individual and community well‐being. In the current study, we use survey data from a nationally representative sample to examine how sociopolitical attitudes, such as political cynicism, perceptions of institutional discrimination, and political efficacy, along with civic education relate to civic engagement among 593 Black youth, ages 15–25. We found perceived institutional discrimination, political efficacy, and civic education were associated with civic engagement, while political cynicism was not. There is evidence to suggest civic education may strengthen the association between perceived institutional discrimination and civic engagement. The present findings contribute to our understanding of how acknowledging systemic inequity promotes civic engagement among Black youth. Findings are discussed in terms of study limitations and future research directions.
How Adolescents Develop Responsibility: What Can Be Learned From Youth Programs
Authors: Salusky Ida , Larson Reed W. , Griffith Aisha , Wu Joanna , Raffaelli Marcela , Sugimura Niwako , Guzman Maria
Published: August 2014

This theory‐building qualitative study examined how youth develop responsibility within the context of organized youth programs. Interviews were conducted with ethnically diverse youth, parents, and adult leaders from four programs for high school–aged teens. Analysis suggested that youth develop responsibility through a four‐step cycle: (1) voluntarily taking on roles and obligations, (2) experiencing challenge and strain, (3) being motivated to fulfill their obligations, and (4) internalizing a self‐concept that leads to responsible behavior in other contexts. Leaders support this learning cycle by creating program structures and providing ongoing support that helps youth experience ownership of demanding roles. Peers contribute by providing a sense of solidarity while also imposing mutual accountability.
Family Capital: Conceptual Model to Unpack the Intergenerational Transfer of Advantage in Transitions to Adulthood
Authors: Waithaka Eric N.
Published: August 2014

The achievement of the traditional milestones associated with adulthood within the current cohort of young adults appears to differ by social class backgrounds, and these differences may be growing due to the differential support of natal families. However, existing research and theory that looks at intergenerational social mobility does not fully examine the multidimensional aspect of family capital and how this capital is deployed during transitions to adulthood. Therefore, building on the work of Pierre Bourdieu on the forms of family capital in the parental investment framework, this article proposes a conceptual model that examines three kinds of resources that natal families marshal and the mechanisms through which these resources are deployed during transitions to adulthood.
A Twelve‐Year Longitudinal Analysis of Positive Youth Development Among Rural African American Males
Authors: Murry Velma M. , Berkel Cady , Simons Ronald L. , Simons Leslie G. , Gibbons Frederick X.
Published: August 2014

The positive youth development model was explored on a sample of 378 rural African American males to determine its usefulness in predicting HIV‐related risk behaviors. Confidence in ability to self‐regulate and sense of competence to be successful in the future were associated with having caring, involved, vigilant parents. Confident, competent males were more likely to connect with prosocial peers, which in turn provided opportunities to reinforce norms and values to dissuade and avoid engaging in risky behaviors. Growth mixture modeling results identified two subgroups with distinct developmental trajectories of risky behaviors. Group differences were associated with several components of positive youth development. Implications for future research and preventive interventions are discussed.
Forward Thinking: Preparing Our Youth for the Coming World
Authors: Tolan Patrick
Published: August 2014

A central task of adolescence is to help children transform into adult roles and responsibilities. Presently, we are in a time of rapid change in multiple areas of roles and systems that influence the development of adolescents. This article identifies some examples of these important shifts, and suggests that a positive development emphasis can provide important advances in useful research and action related to helping prepare youth for the coming world. In introducing this special issue, the intent is to highlight the many areas of needed research, provide some promising and innovative approaches to such research, and note how these are examples of positive development approaches that have much to offer adolescent research.
Trajectories of Life Satisfaction During Middle School: Relations to Developmental‐Ecological Microsystems and Student Functioning
Authors: Tolan Patrick H. , Larsen Ross
Published: August 2014

The middle‐school years have been associated with declines in functioning and family, peer, and teacher relationships. Yet, trajectory analyses indicate variation in this pattern. Prior focus of trajectory studies has been primarily about problematic functioning. This study brings a positive youth development perspective to how life satisfaction trajectories relate to family, peer, and teacher relationships and functioning. Students in 25 middle schools were tracked to end of eighth grade to identify three life satisfaction trajectories: high maintainers (78%), decliners (12%), and improvers (10%). High maintainers evidence better relationships, more positive functioning, and fewer problems, with specific differences distinguishing improvers from decliners. Findings suggest the value in focusing on positive development as well as trajectories in understanding middle‐school development.
Association of daunorubicin to a lipid nanoemulsion that binds to low-density lipoprotein receptors enhances the antitumour action and decreases the toxicity of the drug in melanoma-bearing mice
Authors: Contente Thaís C , Kretzer Iara F , Filippin-Monteiro Fabiola B , Maria Durvanei A , Maranhão Raul C
Published: August 2014

Objectives

To test the toxicity and antitumoral activity of the compound N-oleyl-daunorubicin (oDNR) with a cholesterol-rich nanoemulsion (LDE) formulation.

Methods

LDE-oDNR was prepared by high-pressure homogenisation of lipid mixtures. B16F10 melanoma cells and NIH/3T3 fibroblasts were used for cytotoxicity tests. The maximum tolerated dose (MTD) of both commercial and LDE-oDNR was determined in mice, and melanoma-bearing mice were used for the antitumoral activity tests.

Key findings

CC50 for LDE-oDNR and DNR in melanoma cells were 200 μm and 15 μm, respectively, but LDE-oDNR was less toxic against fibroblasts than DNR. MTD for LDE-oDNR was 65-fold higher than commercial DNR. In tumour-bearing mice, LDE-oDNR (7.5 μmol/kg) reduced tumour growth by 59 ± 2%, whereas the reduction by DNR was only 23 ± 2%. LDE-oDNR increased survival rates (P < 0.05), which was not achieved by DNR treatment. The number of mice with metastasis was only 30% in LDE-oDNR-treated mice, compared with 82% under DNR treatment. By flow cytometry, there were 9% viable cells in tumours of animals treated with LDE-oDNR compared with 27% in DNR-treated animals. Less haematological toxicity was observed in LDE-oDNR-treated mice.

Conclusions

Compared with DNR, LDE-oDNR improved tumour growth inhibition and survival rates with pronouncedly less toxicity, and thus may become a new tool for cancer treatment.
Design of a Gd‐DOTA‐Phthalocyanine Conjugate Combining MRI Contrast Imaging and Photosensitization Properties as a Potential Molecular Theranostic
Authors: Aydın Tekdaş Duygu , Garifullin Ruslan , Şentürk Berna , Zorlu Yunus , Gundogdu Umut , Atalar Ergin , Tekinay Ayse B. , Chernonosov Alexander A. , Yerli Yusuf , Dumoulin Fabienne , Guler Mustafa O. , Ahsen Vefa , Gürek Ayşe Gül
Published: August 2014

The design and synthesis of a phthalocyanine – Gd‐DOTA conjugate is presented to open the way to novel molecular theranostics, combining the properties of MRI contrast imaging with photodynamic therapy. The rational design of the conjugate integrates isomeric purity of the phthalocyanine core substitution, suitable biocompatibility with the use of polyoxo water‐solubilizing substituents, and a convergent synthetic strategy ended by the use of click chemistry to graft the Gd‐DOTA moiety to the phthalocyanine. Photophysical and photochemical properties, contrast imaging experiments and preliminary in vitro investigations proved that such a combination is relevant and lead to a new type of potential theranostic agent.
First Description of Scrotal Testicles in a Dog Affected by 78, XX Testicular Disorder of Sex Development
Authors: Del Carro AP , Rosset E , Josson‐Schramme A , Lambert V , Buff S
Published: August 2014

Contents

An eight‐month‐old female dog presented with ambiguous external genitalia. A thorough clinical examination together with various imaging techniques and a histology examination showed the presence of two testicles linked to both the Mullerian and Wolffian ducts. The discovery of the 78,XX SRY‐negative karyotype led to the diagnosis of incoherence between the chromosomal and gonadal sex, which is typical for a 78,XX testicular disorder of sex development. Our case was unique because the testicles were still located in their normal scrotal position, whereas the literature contains reports of the presence of cryptorchid testicles in this karyotype setting. To our knowledge, this is the first case that describes an SRY‐negative 78,XX testicular disorder of sex development with bilateral scrotal testicles.
Inhibition of Angiotensin‐Converting Enzyme Increases Oestradiol Production in Ewes Submitted to Oestrous Synchronization Protocol
Authors: Costa AS , Junior AS , Viana GEN , Muratori MCS , Reis AM , Costa APR
Published: August 2014

Contents

This study aimed at evaluating the effects of angiotensin‐converting enzyme inhibitor (enalapril) and angiotensin II antagonist (valsartan) on the oestradiol and progesterone production in ewes submitted to oestrous synchronization protocol. The animals were weighed and randomly divided into three groups (n = 7). A pre‐experiment conducted to verify the effectiveness and toxicity of enalapril (0.5 mg/kg LW) and valsartan (2.2 mg/kg LW) showed that, in the doses used, these drugs were effective in reducing blood pressure without producing toxic effects. In the experiment, all animals were subjected to oestrous synchronization protocol during 12 days. On D10, D11 and D12, animals received saline, enalapril or valsartan (same doses of the pre‐experiment), according to the group randomly divided. The hormonal analysis showed an increase in oestradiol on the last day of the protocol (D12) in animals that received enalapril (p < 0.05), but not in other groups, without changing the concentration of progesterone in any of the treatments. It is concluded that valsartan and enalapril are safe and effective subcutaneously for use in sheep and that the angiotensin‐converting enzyme (ACE) inhibition with enalapril leads to an increase in oestradiol production near ovulation without changing the concentration of progesterone. This shows that ACE inhibition may be a useful tool in reproductive biotechnologies involving induction and synchronization of oestrus and ovulation in sheep.
The Importance of Having Zinc During In Vitro Maturation of Cattle Cumulus–Oocyte Complex: Role of Cumulus Cells
Authors: Anchordoquy JM , Anchordoquy JP , Sirini MA , Picco SJ , Peral‐García P , Furnus CC
Published: August 2014

Contents

The aim of this study was to investigate the influence of zinc (Zn) on the health of cumulus–oocyte complex (COC) during in vitro maturation (IVM). Experiments were designed to evaluate the effect of Zn added to IVM medium on: DNA integrity, apoptosis, cumulus expansion and superoxide dismutase (SOD) activity of cumulus cells (CC). Also, role of CC on Zn transport during IVM was evaluated on oocyte developmental capacity. DNA damage and early apoptosis were higher in CC matured with 0 μg/ml Zn compared with 0.7, 1.1 and 1.5 μg/ml Zn (p < 0.05). Cumulus expansion did not show differences in COC matured with or without Zn supplementation (p > 0.05). Superoxide dismutase activity was higher in COC matured with 1.5 μg/ml Zn than with 0 μg/ml Zn (p < 0.05). Cleavage and blastocyst rates were recorded after IVM in three maturation systems: intact COCs, denuded oocytes with cumulus cells monolayer (DO + CC) and denuded oocytes (DO). Cleavage rates were similar when COC, DO + CC or DO were matured with 1.5 μg/ml Zn compared with control group (p > 0.05). Blastocyst rates were significantly higher in COC than in DO + CC and DO with the addition of 1.5 μg/ml Zn during IVM (p < 0.01). Blastocyst quality was enhanced in COC and DO + CC compared with DO when Zn was added to IVM medium (p < 0.001). The results of this study indicate that Zn supplementation to IVM medium (i) decreased DNA damage and apoptosis in CC; (ii) increased SOD activity in CC; (iii) did not modify cumulus expansion and cleavage rates after in vitro fertilization; (iv) improved subsequent embryo development up to blastocyst stage; and (v) enhanced blastocyst quality when CC were present either in intact COC or in coculture during IVM.
Expression of Perilipin 2 (PLIN2) in Porcine Oocytes During Maturation
Authors: Zhang RN , Fu XW , Jia BY , Liu C , Cheng KR , Zhu SE
Published: August 2014

Contents

Perilipins have been reported to limit the interaction of lipases with neutral lipids within the droplets, thereby regulating neutral lipid accumulation and utilization. This study aimed to identify the location and expression of PLIN1 and PLIN2 in porcine oocytes during maturation. Quantitative real‐time polymerase chain reaction (qRT‐PCR), immunostaining and Western blot methods were used to characterize the expression and distribution patterns of PLIN1 and PLIN2 in porcine oocytes. The results showed that PLIN1 was not detectable in porcine oocytes. PLIN2 and BODIPY 493/503‐detected neutral lipid droplets appeared identical distribution patterns and extensive colocalization in both GV and MII porcine oocytes. PLIN2 protein expression was higher in GV oocytes than that in MII oocytes (p < 0.05), although PLIN2 mRNA expression was similar in both groups. These findings suggested that PLIN2 was a major lipid droplet‐associated protein in porcine oocytes.
Increase in skin surface elasticity in normal volunteer subjects following the use of copper oxide impregnated socks
Authors: Dykes P.
Published: August 2014

Background

Copper is an essential mineral involved in the formation and stabilisation of extracellular skin proteins. As copper can be absorbed through intact skin, we reasoned that using socks containing copper‐impregnated fibres may have an effect on skin elasticity.

Methods

A double blind, placebo controlled study was conducted in which one group of healthy volunteers (n = 32) wore socks with fibres containing microscopic copper oxide particles and the other group wore identical socks without copper oxide (n = 28). The socks were worn for at least 10 h a day for 4 weeks. Skin elasticity measurements were taken from three separate test sites on the side of the ankle using a Cutometer at baseline and after 2 and 4 weeks of product use.

Results

There was an increase in the mean net skin elasticity (R5) of 6.4% (P = 0.6) and 31.4% (P = 0.004) after 2 and 4 weeks respectively, in the group of individuals that used the copper oxide containing socks, but no increase in the group of individuals that used the control socks. Similarly, there was an increase in the mean biological elasticity (R7 values) of 3% (P = 0.55) and 20.7% (0.014) after 2 and 4 weeks, respectively, only in the group of individuals that used the copper oxide containing socks. The differences between treatments (i.e. socks used) were statistically significant at 4 weeks (P = 0.0058 and P = 0.0327 for R5 and R7, respectively).

Conclusion

Using copper oxide containing socks results in an increase in skin elasticity of the feet.
The economic burden of pneumonia and meningitis among children less than five years old in Hanoi, Vietnam
Authors: Le Phuc , Griffiths Ulla K. , Anh Dang D. , Franzini Luisa , Chan Wenyaw , Pham Ha , Swint John M.
Published: August 2014

Objective

To estimate the average treatment costs of pneumonia and meningitis among children under five years of age in a tertiary hospital in Hanoi, Vietnam from societal, health sector and household perspectives.

Methods

We used a cost‐of‐illness approach to identify cost categories to be included for different perspectives. A prospective survey was conducted among eligible patients to get detailed personal costing items.

Results

From the perspective of the health sector, the mean costs for treating a case of pneumonia and meningitis were USD 180 and USD 300, respectively. From the household's perspective, the average treatment costs were USD 272 for pneumonia and USD 534 for meningitis. When also including indirect costs, the average total treatment costs from the societal perspective were USD 318 for pneumonia and USD 727 for meningitis.

Conclusion

The study contributed to limited evidence on the high treatment costs of pneumonia and meningitis to the Vietnamese society, which is useful for a cost‐effectiveness analysis of Haemophilus influenzae type b vaccine or other relevant disease preventions. It also indicated a need to re‐evaluate the health insurance policy for children under 6 years old, so that the unnecessarily high out‐of‐pocket costs of these diseases are reduced.
Co‐producing Caribbean geographies of in/security
Authors: Noxolo Patricia , Featherstone David
Published: August 2014

This commentary is a friendly response to Chris Philo's Boundary Crossing article on the relevance of security as a theme for that year'sRGSAnnual Conference (Philo C 2012 Security of geography⁄geography of securityTransactions of the Institute of British Geographers37 1–7). The article did the important preliminary work of unfixing the meanings of security, and in particular introduced a fertile heuristic distinction between big‐S and small‐s security. This article seeks to bring this useful distinction into relationship with this year's (2014)RGSconference theme, the co‐production of knowledge, through a located focus on the co‐production of Caribbean big‐S and small‐s securities. It argues ultimately that co‐production is a concept that needs to be used critically, and that engagement with Caribbean and other postcolonial theorists would be an excellent starting point.
Calcium in the heart: from physiology to disease
Authors: Eisner David
Published: August 2014

New Findings

What is the topic of this review?

This review considers the factors that regulate the systolic Ca transient in cardiac muscle and how disturbed Ca signalling can result in heart failure and arrhythmias.

What advances does it highlight?

Sarcoplasmic Reticulum (SR) Ca content is controlled by a mechanism in which it is regulated by alterations in Ca fluxes across the surface membrane. This has important consequences for the regulation of the size of the systolic Ca transient.

Contraction of the heart results from an increase of cytoplasmic Ca2+ concentration ([Ca2+]i), the so‐called systolic Ca2+ transient. Most of this results from the release of Ca2+ from the sarcoplasmic reticulum (SR) through the ryanodine receptor (RyR). In turn, the amplitude of this Ca2+ transient determines the contractility of the heart. In this lecture, I consider the factors which govern the size and stability of this Ca2+ release. The amplitude of the Ca2+ transient is a steep function of SR Ca, resulting in a requirement for very precise beat‐to‐beat regulation of SR Ca content. This is achieved by a simple negative feedback mechanism, in which an increase of SR Ca content increases the size of the Ca2+ transient, resulting in a decrease of Ca2+ influx on the L‐type Ca2+ current and an increase of efflux through Na+–Ca2+ exchange. Changing the activity of any of the Ca2+‐cycling proteins will change the steady‐state SR Ca content. This feedback mechanism has many consequences, including the fact that a change of RyR open probability has a only a temporary effect on the amplitude of the Ca2+ transient due to a compensating change of SR Ca content. The remainder of the article considers the link between intracellular Ca2+ waves and arrhythmias. This is done in the context of catecholaminergic polymorphic ventricular tachycardia, which is an inherited arrhythmia syndrome, in many cases due to a RyR mutation, where arrhythmias occur during exercise as a result of β‐adrenergic stimulation. Calcium waves occur only when the SR Ca content exceeds a threshold level. Our data show that the threshold is reduced by the RyR mutation and that the adrenergic stimulation increases SR Ca content.
Erythropoietin administration alone or in combination with endurance training affects neither skeletal muscle morphology nor angiogenesis in healthy young men
Authors: Larsen Mads S. , Vissing Kristian , Thams Line , Sieljacks Peter , Dalgas Ulrik , Nellemann Birgitte , Christensen Britt
Published: August 2014

New Findings

What is the central question of this study?

Is an erythropoiesis‐stimulating agent (ESA), alone or in combination with endurance training, able to induce changes in human skeletal muscle fibre and vascular morphology?

What is the main finding and its importance?

Human skeletal muscle morphology and angiogenetic effects did not exhibit sensitivity to ESA treatment alone. Endurance training stimulates angiogenesis and fibre type transition in the direction of a more oxidative fibre phenotype; however, addition of ESA had no further effect.

The aim was to investigate the ability of an erythropoiesis‐stimulating agent (ESA), alone or in combination with endurance training, to induce changes in human skeletal muscle fibre and vascular morphology. In a comparative study, 36 healthy untrained men were randomly dispersed into the following four groups: sedentary–placebo (SP, n = 9); sedentary–ESA (SE, n = 9); training–placebo (TP, n = 10); or training–ESA (TE, n = 8). The ESA or placebo was injected once weekly. Training consisted of progressive bicycling three times per week for 10 weeks. Before and after the intervention period, muscle biopsies and magnetic resonance images were collected from the thigh muscles, blood was collected, body composition measured and endurance exercise performance evaluated. The ESA treatment (SE and TE) led to elevated haematocrit, and both ESA treatment and training (SE, TP and TE) increased maximal O2 uptake. With regard to skeletal muscle morphology, TP alone exhibited increases in whole‐muscle cross‐sectional area and fibre diameter of all fibre types. Also exclusively for TP was an increase in type IIa fibres and a corresponding decrease in type IIx fibres. Furthermore, an overall training effect (TP and TE) was statistically demonstrated in whole‐muscle cross‐sectional area, muscle fibre diameter and type IIa and type IIx fibre distribution. With regard to muscle vascular morphology, TP and TE both promoted a rise in capillary to muscle fibre ratio, with no differences between the two groups. There were no effects of ESA treatment on any of the muscle morphological parameters. Despite the haematopoietic effects of ESA, we provide novel evidence that endurance training rather than ESA treatment induces adaptational changes in angiogenesis and muscle morphology.
Activation of TRPC channels contributes to OA‐NO2‐induced responses in guinea‐pig dorsal root ganglion neurons
Authors: Zhang Xiulin , Beckel Jonathan M. , Daugherty Stephanie L. , Wang Ting , Woodcock Stephen R. , Freeman Bruce A. , de Groat William C.
Published: August 2014

Key points

Nitro‐oleic acid (OA‐NO2) and related nitroalkenes are electrophilic fatty acid derivatives that function as metabolic and anti‐inflammatory signalling mediators and contribute to resolution of inflammation.

OA‐NO2 is known to activate transient receptor potential (TRP) A1 and V1 channels in rat and mouse primary sensory neurons.

However, in guinea‐pig dorsal root ganglion neurons OA‐NO2 activated TRPC channels and elicited a transient excitatory effect followed by a long‐lasting inhibitory effect.

Our data challenge the prevailing view that electrophilic compounds act specifically on TRPA1 and suggest that OA‐NO2 can exert a modulatory effect on sensory mechanisms via activation of TRPC channels.

Effects of nitro‐oleic acid (OA‐NO2) on TRP channels were examined in guinea‐pig dissociated dorsal root ganglia (DRG) neurons using calcium imaging and patch clamp techniques. OA‐NO2 increased intracellular Ca2+ in 60–80% DRG neurons. 1‐Oleoyl‐2acetyl‐sn‐glycerol (OAG), a TRPC agonist, elicited responses in 36% of OA‐NO2‐sensitive neurons while capsaicin (TRPV1 agonist) or allyl‐isothiocyanate (AITC, TRPA1 agonist) elicited responses in only 16% and 10%, respectively, of these neurons. A TRPV1 antagonist (diarylpiperazine, 5 μm) in combination with a TRPA1 antagonist (HC‐030031, 30 μm) did not change the amplitude of the Ca2+ transients or percentage of neurons responding to OA‐NO2; however, a reducing agent DTT (50 mm) or La3+ (50 μm) completely abolished OA‐NO2 responses. OA‐NO2 also induced a transient inward current associated with a membrane depolarization followed by a prolonged outward current and hyperpolarization in 80% of neurons. The reversal potentials of inward and outward currents were approximately −20 mV and −60 mV, respectively. Inward current was reduced when extracellular Na+ was absent, but unchanged by niflumic acid (100 μm), a Cl− channel blocker. Outward current was abolished in the absence of extracellular Ca2+ or a combination of two Ca2+‐activated K+ channel blockers (iberiotoxin, 100 nm and apamin, 1 μm). BTP2 (1 or 10 μm), a broad spectrum TRPC antagonist, or La3+ (50 μm) completely abolished OA‐NO2 currents. RT‐PCR performed on mRNA extracted from DRGs revealed the expression of all seven subtypes of TRPC channels. These results support the hypothesis that OA‐NO2 activates TRPC channels other than the TRPV1 and TRPA1 channels already known to be targets in rat and mouse sensory neurons and challenge the prevailing view that electrophilic compounds act specifically on TRPA1 or TRPV1 channels. The modulation of sensory neuron excitability via actions on multiple TRP channels can contribute to the anti‐inflammatory effect of OA‐NO2.
PGC1‐α over‐expression prevents metabolic alterations and soleus muscle atrophy in hindlimb unloaded mice
Authors: Cannavino Jessica , Brocca Lorenza , Sandri Marco , Bottinelli Roberto , Pellegrino Maria Antonietta
Published: August 2014

Key points

Oxidative stress is widely considered a major cause of muscle loss not only in disuse but also in most chronic diseases, triggering carbonylation of proteins and activation of catabolic pathways involved in their degradation.

Here we show that administration of an antioxidant prevents redox imbalance, but does not prevent activation of catabolic pathways and muscle atrophy.

We indicate that alterations of oxidative metabolism, occurring in slow soleus muscle, are not just a consequence of disuse, but a major cause of activation of catabolic pathways and loss of mass.

This conclusion is confirmed by the observation that muscle‐specific overexpression of PGC‐1α, a master regulator of mitochondrial biogenesis, prevents activation of catabolic systems and disuse muscle atrophy.

These findings contribute to a better mechanistic understanding of disuse muscle loss.

Prolonged skeletal muscle inactivity causes muscle fibre atrophy. Redox imbalance has been considered one of the major triggers of skeletal muscle disuse atrophy, but whether redox imbalance is actually the major cause or simply a consequence of muscle disuse remains of debate. Here we hypothesized that a metabolic stress mediated by PGC‐1α down‐regulation plays a major role in disuse atrophy. First we studied the adaptations of soleus to mice hindlimb unloading (HU) in the early phase of disuse (3 and 7 days of HU) with and without antioxidant treatment (trolox). HU caused a reduction in cross‐sectional area, redox status alteration (NRF2, SOD1 and catalase up‐regulation), and induction of the ubiquitin proteasome system (MuRF‐1 and atrogin‐1 mRNA up‐regulation) and autophagy (Beclin1 and p62 mRNA up‐regulation). Trolox completely prevented the induction of NRF2, SOD1 and catalase mRNAs, but not atrophy or induction of catabolic systems in unloaded muscles, suggesting that oxidative stress is not a major cause of disuse atrophy. HU mice showed a marked alteration of oxidative metabolism. PGC‐1α and mitochondrial complexes were down‐regulated and DRP1 was up‐regulated. To define the link between mitochondrial dysfunction and disuse muscle atrophy we unloaded mice overexpressing PGC‐1α. Transgenic PGC‐1α animals did not show metabolic alteration during unloading, preserving muscle size through the reduction of autophagy and proteasome degradation. Our results indicate that mitochondrial dysfunction plays a major role in disuse atrophy and that compounds inducing PGC‐1α expression could be useful to treat/prevent muscle atrophy.
Catecholamine exocytosis during low frequency stimulation in mouse adrenal chromaffin cells is primarily asynchronous and controlled by the novel mechanism of Ca2+ syntilla suppression
Authors: Lefkowitz Jason J. , DeCrescenzo Valerie , Duan Kailai , Bellve Karl D. , Fogarty Kevin E. , Walsh John V. , ZhuGe Ronghua
Published: August 2014

Key points

Although the importance of asynchronous exocytosis is becoming clearer, not enough is known about its roles and mechanisms.

Here we describe the nature of exocytosis in mouse adrenal chromaffin cells during low frequency physiological stimulation, i.e. 0.5 Hz, providing new views.

We report that less than 10% of all catecholaminergic exocytosis during low frequency stimulation is synchronized to a simulated action potential (sAP), i.e. the dominant phase is asynchronous.

This asynchronous phase of exocytosis does not require Ca2+ influx, requires the ryanodine receptor, RyR2, and comprises exocytic events with characteristics similar to those of spontaneous events.

We propose a novel mechanism of disinhibition wherein APs inhibit Ca2+ syntillas, relieving their inhibition of spontaneous exocytosis, which leads to an increase in the asynchronous phase of elicited exocytosis.

The work has the specific physiological implication that basal sympathetic tone associated with the ‘rest and digest’ state is set in part by Ca2+ syntillas. Furthermore, there is evidence that this regulation of exocytosis by Ca2+ syntillas may be a general mechanism that extends to neurons.

Adrenal chromaffin cells (ACCs), stimulated by the splanchnic nerve, generate action potentials (APs) at a frequency near 0.5 Hz in the resting physiological state, at times described as ‘rest and digest’. How such low frequency stimulation in turn elicits sufficient catecholamine exocytosis to set basal sympathetic tone is not readily explained by the classical mechanism of stimulus–secretion coupling, where exocytosis is synchronized to AP‐induced Ca2+ influx. By using simulated action potentials (sAPs) at 0.5 Hz in isolated patch‐clamped mouse ACCs, we show here that less than 10% of all catecholaminergic exocytosis, measured by carbon fibre amperometry, is synchronized to an AP. The asynchronous phase, the dominant phase, of exocytosis does not require Ca2+ influx. Furthermore, increased asynchronous exocytosis is accompanied by an AP‐dependent decrease in frequency of Ca2+ syntillas (i.e. transient, focal Ca2+ release from internal stores) and is ryanodine sensitive. We propose a mechanism of disinhibition, wherein APs suppress Ca2+ syntillas, which themselves inhibit exocytosis as they do in the case of spontaneous catecholaminergic exocytosis.