bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue in the Superficial and Deep Digital Flexor Muscles During Exercise in Thoroughbred Horses
Authors: Takahashi T , Ohmura H , Mukai K , Matsui A , Aida H 
Published: June 2014

IntroductionOne of the causes of injury to the superficial digital flexor tendon (SDFT) is assumed to be repeated high intensity loading of the tendon. Earlier fatigue of the deep digital flexor muscle (DDFM) in comparison to the time of fatigue of the superficial digital flexor muscle (SDFM) is also assumed to increase load on the SDFT during long distance running. This study evaluated the fatigue of SDFM and DDFM with maximal exercise.MethodsTwo wire electrodes were inserted into the SDFM and DDFM of 6 Thoroughbred horses (461–557 kg). Electromyogram (EMG) and hoof strain gauge signals were recorded at 2,500 Hz with horses on an inclined treadmill (6%), and filter processing was applied (high‐pass 10 Hz for EMG and low‐pass 200 Hz for strain gauge). Integrated EMG (iEMG), the median frequency (MF) of EMG, and the stride frequency (SF) were compared using paired t‐test during 100–105% heart rate max exercise and trotting before and after maximal exercise.ResultsThe SF significantly decreased and iEMG of SDFM tended to decrease during maximal exercise (P = 0.055), while MF of EMG in SDFM and DDFM did not change. The iEMG of SDFM and DDFM significantly decreased and MF of EMG in DDFM tended to decrease at a trot after maximal exercise (P = 0.063).ConclusionsThe DDFM may fatigue earlier than SDFM during long distance running. Further study is needed to evaluate the relationship between the decrease in iEMG of SDFM and DDFM during maximal exercise and the injury to SDFT.Ethical Animal ResearchThe study was approved by the Animal Welfare and Ethics Committee of the Japan Racing Association Equine Research Institute. Sources of funding: Japan Racing Association. Competing interests: none.
The alteration of the C‐terminal region of human frataxin distorts its structural dynamics and function
Authors: Faraj Santiago E. , Roman Ernesto A. , Aran Martin , Gallo Mariana , Santos Javier 
Published: June 2014

Friedreich's ataxia (FRDA) is linked to a deficiency of frataxin (FXN), a mitochondrial protein involved in iron‐sulfur cluster synthesis. FXN is a small protein with an α/β fold followed by the C‐terminal region (CTR) with a nonperiodic structure that packs against the protein core. In the present study, we explored the impact of the alteration of the CTR on the stability and dynamics of FXN. We analyzed several pathological and rationally designed CTR mutants using complementary spectroscopic and biophysical approaches. The pathological mutation L198R yields a global destabilization of the structure correlating with a significant and highly localized alteration of dynamics, mainly involving residues that are in contact with L198 in wild‐type FXN. Variant FXN 90–195, which is closely related to the FRDA‐associated mutant FXN 81–193, conserves a globular shape with a native‐like structure. However, the truncation of the CTR results in an extreme alteration of global stability and protein dynamics over a vast range of timescales and encompassing regions far from the CTR, as shown by proton–water exchange rates and 15N‐relaxation measurements. Increased sensitivity to proteolysis, observed in vitro for both mutants, suggests a faster degradation rate in vivo, whereas the enhanced tendency to aggregate exhibited by the truncated variant may account for the loss of functional FXN, with both phenomena providing an explanation as to why the alteration of the CTR causes FRDA. These results contribute to understanding how stability and activity are linked to protein motions and they might be useful for the design of target‐specific ligands to control local protein motions for stability enhancement.
Structure‐based studies on the metal binding of two‐metal‐dependent sugar isomerases
Authors: Prabhu Ponnandy , Doan Thi‐Ngoc‐Thanh , Tiwari Manish , Singh Raushan , Kim Sun Chang , Hong Myoung‐Ki , Kang Yun Chan , Kang Lin‐Woo , Lee Jung‐Kul 
Published: June 2014

Two‐metal‐dependent sugar isomerases are important in the synthesis of rare sugars. Many of their properties, specifically their metal dependency, have not been sufficiently explored. Here we used X‐ray crystallography, site‐directed mutagenesis, isothermal titration calorimetry and electron paramagnetic resonance spectroscopy to investigate the molecular determinants of the metal‐binding affinity of l‐rhamnose isomerase, a two‐Mn2+‐dependent isomerase from Bacillus halodurans (BHRI). The crystal structure of BHRI confirmed the presence of two metal ion‐binding sites: a structural metal ion‐binding site for substrate binding, and a catalytic metal ion‐binding site that catalyzes a hydride shift. One conserved amino acid, W38, in wild‐type BHRI was identified as a critical residue for structural Mn2+ binding and thus the catalytic efficiency of BHRI. This function of W38 was explored by replacing it with other amino acids. Substitution by Phe, His, Lys, Ile or Ala caused complete loss of catalytic activity. The role of W38 was further examined by analyzing the crystal structure of wild‐type BHRI and two inactive mutants of BHRI (W38F and W38A) in complex with Mn2+. A structural comparison of the mutants and the wild‐type revealed differences in their coordination of Mn2+, including changes in metal–ligand bond length and affinity for Mn2+. The role of W38 was further confirmed in another two‐metal‐dependent enzyme: xylose isomerase from Bacillus licheniformis. These data suggest that W38 stabilizes protein–metal complexes and in turn assists ligand binding during catalysis in two‐metal‐dependent isomerases.Structured digital abstractBHRI and BHRI bind by x-ray crystallography (View interaction)
Elucidating the impact of temperature variability and extremes on cereal croplands through remote sensing
Authors: Duncan John M. A. , Dash Jadunandan , Atkinson Peter M. 
Published: June 2014

AbstractRemote sensing‐derived wheat crop yield‐climate models were developed to highlight the impact of temperature variation during thermo‐sensitive periods (anthesis and grain‐filling; TSP) of wheat crop development. Specific questions addressed are: can the impact of temperature variation occurring during the TSP on wheat crop yield be detected using remote sensing data and what is the impact? Do crop critical temperature thresholds during TSP exist in real world cropping landscapes? These questions are tested in one of the world's major wheat breadbaskets of Punjab and Haryana, north‐west India. Warming average minimum temperatures during the TSP had a greater negative impact on wheat crop yield than warming maximum temperatures. Warming minimum and maximum temperatures during the TSP explain a greater amount of variation in wheat crop yield than average growing season temperature. In complex real world cereal croplands there was a variable yield response to critical temperature threshold exceedance, specifically a more pronounced negative impact on wheat yield with increased warming events above 35 °C. The negative impact of warming increases with a later start‐of‐season suggesting earlier sowing can reduce wheat crop exposure harmful temperatures. However, even earlier sown wheat experienced temperature‐induced yield losses, which, when viewed in the context of projected warming up to 2100 indicates adaptive responses should focus on increasing wheat tolerance to heat. This study shows it is possible to capture the impacts of temperature variation during the TSP on wheat crop yield in real world cropping landscapes using remote sensing data; this has important implications for monitoring the impact of climate change, variation and heat extremes on wheat croplands.
Exogenous connective tissue growth factor preserves the hair‐inductive ability of human dermal papilla cells
Authors: Zhang P. , Ravuri S. K. , Wang J. , Marra K. G. , Kling R. E. , Chai J. 
Published: June 2014

SynopsisObjectiveDermal papilla cells are required for inducing epithelial stem cells during hair morphogenesis and regeneration. Adult human dermal papilla cells lose their hair‐inductive capacity after several in vitro culture passages. Maintaining the hair‐inductive capacity of adult human dermal papilla cells is an obstacle that needs to be overcome to realize tissue‐engineered hair follicles. We hypothesized that connective tissue growth factor (CTGF), a fibrogenic factor known to influence Wnt, BMP and TGF‐β, could influence key signalling pathways in human dermal papilla cells. The purpose of this study was to determine the effect of exogenous connective tissue growth factor on cultured human dermal papilla cells.MethodsAdult human dermal papilla cells were isolated and cultured in the presence of CTGF (20 or 40 ng mL−1). Human dermal papilla cells positivity was determined using the alkaline phosphatase immunofluorescence. After treatment with CTGF, the proliferation of human dermal papilla cells was assessed. The presence of connective tissue growth factor in human dermal papilla cells was identified by immunofluorescence. The α‐smooth muscle actin protein expression was evaluated by Western blot. Gene expression profile of Wnt, BMP and TGF‐β signalling pathways as well as alkaline phosphatase and versican activity, were determined using real‐time RT‐PCR.ResultsConnective tissue growth factor reduced proliferation rate of cultured human dermal papilla cells in a dose‐dependent manner. Exogenous connective tissue growth factor increased the expression of cytoplasmic connective tissue growth factor, and increased mRNA expression of alkaline phosphatase and β‐catenin, BMP2 and TGF‐β2 in human dermal papilla cells. Versican mRNA level was suppressed and a small increase in α‐smooth muscle actin protein expression was observed.ConclusionExogenous connective tissue growth factor can preserve the innate hair‐inductive ability of adult human dermal papilla cells in vitro cultures, which is controlled through the Wnt, BMP and TGF‐β signalling pathways.
Determination of melanin types and relative concentrations: an observational study using a non‐invasive inverse skin reflectance analysis
Authors: Hani A. F. M. , Baba R. , Shamsuddin N. , Nugroho H. 
Published: June 2014

SynopsisObjectiveMelanin is a major skin colour pigment that made up of eumelanin (the dark brown–black colour) and pheomelanin (the light red–yellow colour) pigments. Skin‐whitening products typically contain depigmentation agents that reduce the level of pigmentation by changing the pheomelanin–eumelanin production. Similarly, in skin pigment treatment of skin disorders, the melanin production is managed accordingly. To assess and improve treatment efficacy, it is important to have a measurement tool that is capable of determining the melanin types objectively. So far, the efficacy assessment is subjective. In this study, an inverse skin reflectance pigmentation analysis system that determines eumelanin and pheomelanin content is developed and evaluated in an observational study involving 36 participants with skin photo type IV.MethodsThe reflectance spectra of the left forearms of participants were analysed by the pigmentation analysis system to determine their skin parameters – pheomelanin and eumelanin concentrations, melanosome volume fraction, and epidermal thickness. The determined skin parameters are then inputted into the realistic skin model (RSM) of the Advanced Systems Analyses Program (asap®) to generate the ground truth reflectance spectra for the given skin parameters to validate the system.ResultsThe developed pigmentation analysis system is found to be accurate with a spectral error of 0.0163 ± 0.009 between measured reflectance and the reflectance output of the analysis system and RSM. The regression analysis shows a strong linear relationship (R2 = 0.994) indicating good precision. The relative concentrations of pheomelanin (38.23 ± 15.04) and eumelanin (1.68 ± 0.91) analysed by the system gives a ratio of pheomelanin to eumelanin of 0.048 ± 0.029; this value is consistent with previously reported figure of 0.049.ConclusionThe proposed pigmentation analysis system is able to determine melanin types and their relative concentrations. It has the potential to assess the efficacy of the skin‐whitening and pigmentation treatments objectively in a non‐invasive manner.
Photoperiodic effects on diapause‐associated gene expression trajectories in European Leptinotarsa decemlineata populations
Authors: Lehmann P. , Piiroinen S. , Kankare M. , Lyytinen A. , Paljakka M. , Lindström L. 
Published: June 2014

AbstractBehavioural and physiological changes during diapause, an important strategy of insects for surviving harsh seasonal conditions, have been intensively studied. The genetic and molecular mechanisms underpinning diapause development are less well known. We took a candidate gene approach to study prediapause gene expression patterns in the Colorado potato beetle (Leptinotarsa decemlineata), an invasive insect that has rapidly spread northwards to high seasonality environments. Newly eclosed beetles originating from southern (Italy) and northern (Russia) Europe were reared under short‐ [12 h light (L):12 h dark (D)] and long‐day (18L:6D) photoperiods for 10 days. This time period includes the sensitive period for the photoperiodic induction and initiation of diapause. Gene expression trajectories of 12 diapause‐related genes (regulatory, metabolic and stress‐resistance) were analysed from 0‐, 5‐ and 10‐day‐old beetles. Gene expression differences increased with age, deviating significantly between populations and photoperiods in 10‐day‐old beetles. The gene expression profiles, particularly those related to energy metabolism and stress‐resistance, indicate that beetles originating from Russia also prepare for diapause under the long‐day photoperiod and show qualitative differences in the diapausing phenotype. Our study shows that population‐dependent differences seen in behavioural and physiological traits connected with diapause in L. decemlineata are also evident in the expression trajectories of diapause‐related genes.
Methuselah‐likegenes affect development, stress resistance, lifespan and reproduction inTribolium castaneum
Authors: Li Chengjun , Zhang Yi , Yun Xiaopei , Wang Yanyun , Sang Ming , Liu Xing , Hu Xingxing , Li Bin 
Published: June 2014

AbstractMethuselah (Mth) is associated with lifespan, stress resistance and reproduction inDrosophila melanogaster, but Mth is not present in nondrosophiline insects. A number ofmethuselah‐likes(mthls) have been identified in nondrosophiline insects, but it is unknown whether the functions ofmthare shared bymthlsor are divergent from them. Fivemthlshave been identified inTribolium castaneum. Although they have different developmental expression patterns, they all enhance resistance to starvation. Onlymthl1andmthl2enhance resistance to high temperature, whereasmthl4andmthl5negatively regulate oxidative stress inT. castaneum. Unlike in the fly withmthmutation, knockdown ofmthls, exceptmthl3, shortens the lifespan ofT. castaneum. Moreover,mthl1andmthl2are critical forTriboliumdevelopment.mthl1plays important roles in larval and pupal development and adult eclosion, whilemthl2is required for eclosion. Moreover,mthl1andmthl2silencing reduces the fertility ofT. castaneum, andmthl1andmthl4are also essential for embryo development. In conclusion,mthlshave a significant effect on insect development, lifespan, stress resistance and reproduction. These results provide experimental evidence for functional divergence amongmthls/mthand clues for the signal transduction ofMthls.
Violence, Networks, and International Migration from Colombia
Authors: Silva Adriana Carolina , Massey Douglas S. 
Published: June 2014

AbstractAlthough Colombia is a major country of emigration, little is known about its citizens' motivations for migration. Social and economic conditions have been studied as determinants of migration, but violence has received less attention. We examine how social networks and violence function to promote emigration from Colombia by linking event‐history data from the Latin American Migration Project to external data on violence and economic conditions. We show that emigration is more likely to be initiated by those with higher education, those with network connections to migrants, and during periods of greater violence and increased police presence. Although violence acts powerfully to determine when people migrate, the geographic distribution of social capital determines where they go. Not surprisingly, migrants go to locations where people in their social networks are currently living or have been earlier.
Exploring the impact of employment policy measures in the context of crisis: The case of Greece
Authors: Dimoulas Constantine 
Published: June 2014

AbstractThe article addresses the economic, social and political dimensions of the Greek work‐welfare nexus in the context of the recent financial crisis. Explaining the main social protection and activation measures before and during the crisis (a reduction in salaries and in the purchasing power of employees partnered with unemployment benefits, contribution subsidies for employers, training and work‐practice vouchers, and fixed‐term quasi‐employment in community services), analysis is offered of the impacts of these. The article concludes that employment measures in Greece are not only residual and inadequate to meet the needs of the unemployed but have not curbed rising unemployment rates.
Networking the unemployed: Can policy interventions facilitate access to employment through informal channels?
Authors: Bonoli Giuliano 
Published: June 2014

AbstractIt is widely known that informal contacts and networks constitute a major advantage when searching for a job. Unemployed people are likely to benefit from such informal contacts, but building and sustaining a network can be particularly difficult when out of employment. Interventions that allow unemployed people to effectively strengthen their networking capability could as a result be promising. Against this background, this article provides some hints in relation to the direction that such interventions could take. First, on the basis of data collected on a sample of 4,600 newly‐unemployed people in the Swiss Canton of Vaud, it looks at the factors that influence jobseekers' decisions to turn to informal contacts for their job search. The article shows that many unemployed people are not making use of their network because they are unaware of the importance of this method. Second, it presents an impact analysis of an innovative intervention designed to raise awareness of the importance of networks which is tested in a randomized controlled trial setting.
Impact of adrenalectomy and dexamethasone treatment on testicular morphology and sperm parameters in rats: insights into the adrenal control of male reproduction
Authors: Silva E. J. R. , Vendramini V. , Restelli A. , Bertolla R. P. , Kempinas W. G. , Avellar M. C. W. 
Published: June 2014

SummaryHere we investigated the hypothesis that normal levels of glucocorticoids, a class of adrenal steroid hormones, are required for normal testicular and epididymal functions. We examined the effects of the manipulation of glucocorticoid plasma levels by bilateral adrenalectomy (1, 2, 7 and 15 days) alone or in combination with daily treatment with the synthetic glucocorticoid dexamethasone (DEX; 5 μg/kg, i.p., 6 days) on the morphology of the testis and sperm parameters in rats. We showed that adrenalectomy led to a reduction in testicular sperm count and daily sperm production starting 2 days after surgery and a differential decrease in sperm count in the epididymis, according to the region and time post‐adrenalectomy analysed. In parallel, testes from 7‐day adrenalectomized (ADX) rats displayed a higher frequency of damaged seminiferous tubules and the presence of elongated spermatids retained in the basal epithelial compartment in stages IX–XVII, which is indicative of defective spermiation. The alkaline comet assay revealed a late effect of adrenalectomy on epididymal sperm DNA fragmentation, which was increased only 15 days after surgery. DEX treatment prevented the changes in testicular and epididymal sperm count observed in 7‐day ADX rats, but failed to protect the testis from ADX‐induced morphological abnormalities. Thus, our results indicated that glucocorticoids may be involved in events related to the maintenance of spermatogenesis and sperm maturation during adulthood. These findings provide new insights into the importance of adrenal steroids to male fertility.
Testicular histomorphologic and stereological alterations following short‐term treatment with highly active antiretroviral drugs (HAART) in an experimental animal model
Authors: Azu O. O. , Naidu E. C. S. , Naidu J. S. , Masia T. , Nzemande N. F. , Chuturgoon A. , Singh S. 
Published: June 2014

SummaryThe increased accessibility of antiretroviral therapy continues to positively drive the reduction in viral load and survival of patients despite the attendant reproductive toxicities. We propose that testicular damage caused by highly active antiretroviral therapy (HAART) can be attenuated by antioxidant treatment by investigating the testicular histomorphologic and stereological effects of antiretroviral drugs and its interaction with antioxidants using an experimental animal model. Sprague–Dawley rats were divided into seven groups of six rats per group (A, B… G) using simple random sampling and treated orally with 0.9% normal saline as placebo, a HAART cocktail of stavudine, lamivudine and nevirapine using the adjusted human therapeutic doses of 200, 600 and 350–400 mg/day, respectively, and antioxidants ascorbic acid (vitamin C) and I.M α‐tocopherol (vitamin E). Animals were killed after 4 weeks and testicular tissue harvested and processed for light microscopy and stereological evaluations. The results were interpreted by a Veterinary pathologist blinded to the study. No animal died during the experimental period. The histopathological assessment of the testis of animals treated with placebo, ascorbic acid alone and α‐tocopherol alone as well as vitamin E + HAART displayed normal testicular microanatomy. Groups treated with HAART alone, HAART + vitamin C + vitamin E and vitamins C + HAART showed extensive seminiferous tubular atrophy, necrosis and hypocellularity in the histoarchitectural patterns. While testicular cross‐sectional area of seminiferous tubules remained unaffected by HAART, epithelial heights significantly decreased (p < 0.05) when compared with controls. There was marked (p < 0.05) increased in testicular‐body weight ratio in HAART group. The results show that vitamin E could be useful in protecting testicular tissue from toxicities of HAART regimes as these results mirrors stereological data for the groups. HAART presents with deleterious histopathological changes in the testes causing tubular atrophy with altered morphometric indices. Supplementation with vitamin E appears to be a better adjuvant antioxidant that ameliorates these deleterious effects.