bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of density‐dependent growth at two spatial scales in marble trout (Salmo marmoratus) populations
Authors: Vincenzi S. , Crivelli A. J. , Jesensek D. , De Leo G. A.
Published: May 2010

Vincenzi S, Crivelli AJ, Jesensek D, De Leo GA. Detection of density‐dependent growth at two spatial scales in marble trout (Salmo marmoratus) populations. Ecology of Freshwater Fish 2010: 19: 338–347. © 2010 John Wiley & Sons A/S

Abstract – Density‐dependent body growth has often been observed in freshwater salmonid populations. Several studies suggest this compensatory pattern as a potential mechanism of population regulation. The choice of the spatial scale is important for the detection of density‐dependent growth, as study areas need to be of the appropriate size to capture the density of conspecifics actually experienced by individuals over the preceding growth period. Here, we used four marble trout (Salmo marmoratus) populations (Gatsnik, Gorska, Huda and Zakojska) living in Slovenian stream to study the relationships between early density of marble trout and subsequent body growth. As streams are divided in sectors delimited by natural barriers that prevent or strongly limit movement of individuals, we tested the relationship between early density and body size through the lifetime at two spatial scales, that is,sectorlevel (for Gatsnik and Zakojska) andwhole streamlevel (the four populations were pooled). Sector length in Gatsnik and Zakojska ranged from 113 to 516 m. At bothsectorandwhole streamlevel, temporal data were pooled. Growth declined significantly with increasing density both at thesectorandwhole streamlevels, and the density‐dependent relationship was described by negative power curves. However, at thesectorlevel the density‐dependent pattern was stronger in Gatsnik, a stream in which fish could move across sectors, than in Zakojska, where upstream movement across sectors is prevented by waterfalls.
Ontogenetic and spatial variations in brown trout habitat selection
Authors: Ayllón D. , Almodóvar A. , Nicola G. G. , Elvira B.
Published: May 2010

Ayllón D, Almodóvar A, Nicola GG, Elvira B. Ontogenetic and spatial variations in brown trout habitat selection. Ecology of Freshwater Fish 2010: 19: 420–432. © 2010 John Wiley & Sons A/S

Abstract –  Habitat quality and quantity determine many biological processes and traits that directly affect the population dynamics of stream fishes. Understanding how habitat selection is adjusted to different ecological conditions is essential to improve predictive modelling of population dynamics. We describe brown trout Salmo trutta summer habitat selection patterns through univariate and multivariate habitat selection functions across defined river reach typologies. We sampled 44 sites and performed a principal component analysis that defined eight reach types differing in both local site and catchment‐scale physical features. We observed ontogenetic changes in habitat selection, as trout preferred deeper and slower flowing water as they increased in size. Likewise, selectivity for different types of structural habitat elements changed through ontogeny. Both patterns were consistent across reach types. Moreover, we detected spatial variations in habitat selection patterns within age‐classes among different reach types. Our results indicate that brown trout is a habitat generalist and suggest that spatial variations in habitat selection patterns are driven by physical and environmental factors operating at multiple spatial scales.
Thermoregulatory demands of Elite Professional America's Cup Yacht Racing
Authors: Neville V. , Gant N. , Folland J. P.
Published: May 2010

America's Cup yacht racing predominantly occurs during the summer months under hot and humid conditions, with athletes exposed to the environment for prolonged periods, and yet the thermoregulatory responses to competitive sailing are largely unappreciated. This study aimed to assess the thermoregulatory responses to elite professional big‐boat yacht racing, according to crew position and upwind and downwind sailing. Intestinal (Tcore) and skin temperature, fluid balance and regional sweat compositions were measured in two America's Cup crews (n=32) during 100 min of racing. The environmental conditions were as follows: 32 °C, 52% RH and 5 m/s wind speed. Subjective race intensity was moderate. Bowmen recorded the greatest elevation in the heart rate (184 ± 10 beats/min) and Tcore (39.2 °C, P<0.01). Both heart rate and Tcore were higher during downwind sailing (P<0.001). Regional skin temperatures were significantly different according to site (P=0.05), with tibia being the lowest (33.3 ± 1.2 °C). The mean sweat loss during racing was 1.34 ± 0.58 L/h (range: 0.44–2.40 L/h), with bowmen experiencing the greatest loss of sweat (3.7 ± 0.9% of body mass). The mean fluid intake was highly correlated to sweat loss (r=0.74, P<0.001), with 72 ± 41% of sweat losses replaced. The mean sodium concentration of sweat was 27.2 ± 9.2 mmol/L (range: 12.0–43.5 mmol/L) and the total NaCl loss during sailing was 3.8 ± 2.4 g (range 0.7–10.0 g). America's Cup sailing is a demanding sport that presents considerable challenges to thermoregulation, fluid and electrolyte balance. Certain crew roles (bowmen) present an increased risk of developing exertional heat illness, and for the majority of crew downwind sailing results in greater thermal strain than upwind sailing – which may have implications for clothing selection and boat design.
Prolonged immobilization compromises up‐regulation of repair genes after tendon rupture in a rat model
Authors: Bring D. , Reno C. , Renstrom P. , Salo P. , Hart D. , Ackermann P.
Published: May 2010

It was hypothesized that mobilization vs immobilization after injury would promote tissue healing by regulating gene expression for molecules associated with repair. Cast immobilization vs free mobilization was studied after rat Achilles tendon rupture. Reverse transcriptase‐polymerase chain reaction was performed at 8 and 17 days post‐rupture to assess different growth factors [brain‐derived neurotrophic factor (BDNF), basic fibroblast growth factor (bFGF), nerve growth factor (NGF) and insulin‐like growth factor‐1 (IGF‐1)] and inflammatory mediators [cyclooxygenase 1 and 2 (COX 1 and COX 2), inducible nitric oxide synthase and hypoxia‐inducible factor‐1α (HIF‐1α)] in the healing region. At 8 days post‐injury, tendon mRNA levels were comparable in both groups. However, by day 17, the mRNA levels for BDNF, bFGF, COX 1 and HIF‐1α in the mobilized group had increased significantly. Corresponding mRNA levels in the immobilized group decreased during the same period. There were no significant differences in the expression of NGF, IGF‐1 or COX 2 between the different groups, indicating that injury‐associated expression of these molecules is not overtly influenced by loading. This study supports the notion that prolonged immobilization post‐rupture hampers the healing process by compromising the up‐regulation of repair gene expression in the healing tendon. It might be speculated that a shorter period of immobilization, i.e. 1 week, would not impair the healing process significantly. The findings support the current development of earlier and more active rehabilitation programs after tendon injuries.
Type of sport is related to injury profile: A study on cross country skiers, swimmers, long‐distance runners and soccer players. A retrospective 12‐month study
Authors: Ristolainen L. , Heinonen A. , Turunen H. , Mannström H. , Waller B. , Kettunen J. A. , Kujala U. M.
Published: May 2010

This 12‐month retrospective questionnaire compared the occurrence of sports injuries in 149 cross country skiers, 154 swimmers, 143 long‐distance runners and 128 soccer players aged 15–35 years. Soccer had significantly more injuries (5.1 injuries/1000 exposure hour) than other sports (2.1–2.8, P<0.001). More runners than soccer players reported overuse injuries (59% vs 42%, P=0.005), locating typically in the foot in runners, soccer players and skiers. Swimmers reported overuse injuries in the shoulder more commonly than skiers (40% vs 1%, P<0.001), who also intensively load shoulders. Acute injuries in skiers (80%) and in swimmers (58%), and overuse injuries in skiers (61%), occurred during exercise other than own event. In soccer and running the absence time from sport because of injuries was significantly longer than in skiing and swimming. No severe permanent disabilities occurred due to injury but seven women quit sports because of injury. In conclusion, type of loading is strictly associated with the anatomical location of an overuse injury as shown by the difference in shoulder injury incidence between swimmers and cross country skiers. In some sports, a significant proportion of acute injuries occur in other than the main event.
Calculation of the contact pressure between ski and snow during a carved turn in Alpine skiing
Authors: Heinrich D. , Mössner M. , Kaps P. , Nachbauer W.
Published: May 2010

The macroscopic contact area between ski and snow and the contact pressure are crucial influencing factors for carved turns in Alpine skiing. In the present paper, a simulation model is developed to quantify these factors. The ski is modelled as an Euler–Bernoulli beam with variable cross section, camber, bending and torsional stiffness using measured data from skis. The reaction forces of the snow are decomposed in penetration and shear forces. For the penetration forces a hypoplastic constitutive law is applied incorporating elastic and plastic deformation of the snow at the contact area. For the shear forces metal cutting theory is used. Ski deformation, contact area and contact pressure are computed based on quasi‐static equilibrium between forces exerted by the skier and snow reaction forces. Parameter studies are performed to investigate the influence of edging and distributing the load between the inner and outer ski. Higher edging angles as well as loading both skis affected the contact pressure positively by increasing the resistance against shearing. The results of our study agree well with measurement data taken from literature. Based on the results, the importance of actions of the skier during carved turns is concluded.
Clinical assessment of hip strength using a hand‐held dynamometer is reliable
Authors: Thorborg K. , Petersen J. , Magnusson S. P. , Hölmich P.
Published: May 2010

Hip strength assessment plays an important role in the clinical examination of the hip and groin region. The primary aim of this study was to examine the absolute test–retest measurement variation concerning standardized strength assessments of hip abduction (ABD), adduction (ADD), external rotation (ER), internal rotation (IR), flexion (FLEX) and extension (EXT) using a hand‐held dynamometer. Nine subjects (five males, four females), physically active for at least 2.5 h a week, were included. Twelve standardized isometric strength tests were performed twice with a 1‐week interval in between by the same examiner. The test order was randomized to avoid systematic bias. Measurement variation between sessions was 3–12%. When the maximum value of four measurements was used, test–retest measurement variation was below 10% in 11 of the 12 individual hip strength tests and below 5% in five of the 12 tests. No systematic differences were present. Standardized strength assessment procedures of hip ABD, ER, IR, FLEX, with test–retest measurement variation below 5%, hip ADD below 6% and hip EXT below 8%, make it possible to determine even small changes in hip strength at the individual level.
Regulation of extracellular matrix compounds involved in angiogenic processes in short‐ and long‐track elite runners
Authors: Suhr F. , Rosenwick C. , Vassiliadis A. , Bloch W. , Brixius K.
Published: May 2010

Exercise induces alterations of the extracellular matrix (ECM), e.g. by an increased release of endostatin or by regulation of matrix metalloproteases (MMP)‐2/‐9, and cathepsin L. To investigate the influence of training status on exercise‐induced ECM‐processing of angiogenic molecules, alterations of endostatin‐, MMP‐2, and MMP‐9 plasma concentrations during incremental running step tests in male elite short‐track (n=6) and male elite long‐track runners (n=7) were studied. Three blood samples (pre‐exercise, 0, and 1 h post‐exercise) were taken from each subject at each running test. In both groups, the basal endostatin plasma concentration was significantly decreased at the second running test, i.e. after the training season. Exercise‐related acute alterations of the parameters were also observed only during the second test. In the long‐track group, there was a significant increase in endostatin at 0 h and of MMP‐2 at 1 h post‐exercise. In the short‐track group, only MMP‐9 was significantly increased at 0 h post‐exercise. Cathepsin L was increased at 0 h post‐exercise. In conclusion, regular exercise performance decreases the basal endostatin plasma concentration, facilitates ECM‐processing of angiogenic molecules by regular performance, and seems to be dependent on the kind of training.
Does a drop landing represent a whole skill landing and is this moderated by fatigue?
Authors: Edwards S. , Steele J. R. , McGhee D. E.
Published: May 2010

This study aimed to determine whether the landing phase of a drop landing (DL) differed with respect to a complete jumping and landing task, a spike jump (SJ), and whether fatigue altered the landing of these movements. Fourteen male volleyball players performed five DL and SJ in a counterbalanced order under two experimental conditions: non‐fatigued and fatigued. Fatigue, induced by repetitive jumping sets, was confirmed by decrements in vertical jump height >25% and increased blood lactate >6 mmol/L. Each landing task was characterized by the resultant ground reaction forces (GRF), sagittal plane kinematics and muscle recruitment patterns of six lower extremity muscles. Two‐way repeated analysis of variance results indicated a main effect of movement on many of the GRF, kinematic and electromyographic variables characterizing landing, indicating that the two tasks required substantially different lower limb biomechanics during landing. Although fatigue did not alter the GRF in either task, there were significant movement × fatigue condition interactions. The significant between‐task differences in the biomechanical variables characterizing landing and the differential effects of fatigue on each landing task, question the validity of using a DL as an experimental task to investigate lower limb landing mechanics of whole jumping and landing movements.
Acute effects of whole‐body vibration on peak isometric torque, muscle twitch torque and voluntary muscle activation of the knee extensors
Authors: Jordan M. , Norris S. , Smith D. , Herzog W.
Published: May 2010

The purpose of this investigation was to compare the acute effects of whole‐body vibration (WBV) with a static squat on resting muscle twitch torque, peak isometric torque and voluntary muscle activation of the knee extensors during an isometric maximal voluntary contraction (MVC). Twenty‐four healthy, strength‐trained males were recruited for this randomized, cross‐over design investigation. The WBV treatment consisted of three sets of 60 s of vibration (30 Hz, ±4 mm) while standing in a semi‐squat position. Voluntary muscle activation, peak isometric torque during MVC and resting muscle twitch torque (RTT) through percutaneous femoral nerve stimulation were obtained before and following the treatment. Change in peak isometric torque, voluntary muscle activation and the RTT were calculated as the difference between pre‐ and post‐treamtent values. There was no observable post‐activation potentiation of muscle twitch torque or enhancement in voluntary muscle activation or peak isometric torque. However, decreases in the peak isometric torque (P=0.0094) and voluntary muscle activation (P=0.0252) were significantly smaller post WBV interventions compared with the control treatment. Based on the current data, it is unclear whether or not this was attributable to the effects of WBV but further research into this possibility is warranted.
Heart rate recovery as a guide to monitor fatigue and predict changes in performance parameters
Authors: Lamberts R. P. , Swart J. , Capostagno B. , Noakes T. D. , Lambert M. I.
Published: May 2010

Determining the optimal balance between training load and recovery contributes to peak performance in well‐trained athletes. The measurement of heart rate recovery (HRR) to monitor this balance has become popular. However, it is not known whether the impairment in performance, which is associated with training‐induced fatigue, is accompanied by a change in HRR. Therefore, the aim of this study was to retrospectively analyze the relationship between changes in HRR and cycling performance in a group of well‐trained cyclists (n=14) who participated in a 4‐week high‐intensity training (HIT) program. Subjects were assigned to either a group that continuous had a increase in HRR (GIncr) or a group that showed a decrease in HRR (GDecr) during the HIT period. Both groups, GIncr and GDecr, showed improvements in the relative peak power output (P=0.001 and 0.016, respectively) and endurance performance parameters (P=0.001 and <0.048, respectively). The average power during the 40‐km time trial (40‐km TT), however, improved more in GIncr (P=0.010), resulting in a tendency for a faster 40‐km TT time (P=0.059). These findings suggest that HRR has the potential to monitor changes in endurance performance and contribute to a more accurate prescription of training load in well‐trained and elite cyclists.
Relative age effect in female sport: a diachronic examination of soccer players
Authors: Delorme N. , Boiché J. , Raspaud M.
Published: May 2010

The relative age effect (RAE) is a biased distribution of elite athletes' birthdates, with an overrepresentation of those born at the beginning of the competitive year and an underrepresentation of those born at the end. Despite an abundant literature, the impact of sex on this phenomenon remains neglected by most researchers. This study investigated the whole sample of female soccer players affiliated to the French Soccer Federation for the 2006–2007 season (n=57 892). It first aimed at testing the presence of RAE depending on age. Next, we looked at the birthdates of dropout players during the next season (n=15 285), to test whether relative age accounts for dropout from the activity. The analyses revealed significant differences between the expected and the observed distributions for all age categories. Furthermore, a significantly biased distribution of dropout players' birthdates was found for the <10, <14, and <17 categories. On the whole, dropout players are underrepresented in Q1 and Q2, but overrepresented in Q3 and Q4. This study completes the literature on RAE among females, but the inconsistency of the results calls for more research on this population.
Association of Neuregulin 1 rs3924999 genotype with antisaccades and smooth pursuit eye movements
Authors: Schmechtig A. , Vassos E. , Kumari V. , Hutton S. B. , Collier D. A. , Morris R. G. , Williams S. C. R. , Ettinger U.
Published: May 2010

Neuregulin 1 (NRG1) has been identified as one of the leading candidate genes for schizophrenia. However, its functional mechanisms and its effects on neurocognition remain unclear. In this study, we used two well‐established oculomotor endophenotypes, the antisaccade (AS) and smooth pursuit eye movement (SPEM) tasks, to investigate the functional mechanisms of a single nucleotide polymorphism (SNP) in NRG1 (rs3924999) at the neurocognitive level in a healthy volunteer sample. A total of 114 healthy Caucasian volunteers completed genotyping for NRG1 rs3924999 and infrared oculographic assessment of AS and SPEM (at target velocities of 12°, 24° and 36° per second). Additionally, self‐report questionnaires of schizotypy, neuroticism, attention deficit hyperactivity and obsessive‐compulsive traits were included. A significant effect of rs3924999 genotype, with gender as a covariate, was found for AS amplitude gain (P < 0.01), with an increasing number of A alleles being associated with increasingly hypermetric performance. No statistically significant associations were found for other AS and SPEM variables or questionnaire scores. These findings indicate that NRG1 rs3924999 affects spatial accuracy on the AS task, suggesting an influence of the gene on the neural mechanisms underlying visuospatial sensorimotor transformations, a mechanism that has been previously found to be impaired in patients with schizophrenia and their relatives.
Disability days in Canada associated with dental problems: a pilot study
Authors: Quiñonez C , Figueiredo R , Locker D
Published: May 2010

To cite this article:
 
Int J Dent Hygiene
9, 2011; 132–135 DOI: 10.1111/j.1601‐5037.2010.00463.x Quiñonez C, Figueiredo R, Locker D. Disability days in Canada associated with dental problems: a pilot study.

Abstract:  Objective:  The aim of this study was to explore disability days, or bed days and cut‐down days, associated with dental problems in Canada. Methods:  Data were collected through a national telephone interview survey of 1005 Canadians aged 18 years and over using random digit dialling. Participants were asked to enumerate the number of disability days associated with dental problems in the previous 2‐week period. Descriptive and bivariate logistic regression analyses were undertaken. Results:  In the previous 2‐week period, 33 people, or 3.3% of the sample, reported spending a day in bed because of a dental problem. Of these, 22 people also reported having to cut down on their normal activity because of the dental problem. It appears that younger age groups, those with the lowest incomes, college educations, no dental insurance, oral pain and a history of visiting a hospital emergency room for a dental problem, were all more likely to report a dental disability day. Conclusions:  These data demonstrate the potential economic impacts of dental problems in Canada, yet they must be interpreted with caution because of the very low prevalence of the main outcome measure, the potential for selection bias and the relative inconsistency with existing historical estimates.
Creativity, Innovation, and Entrepreneurship in China
Authors: Phan Phillip , Zhou Jing , Abrahamson Eric
Published: May 2010

As the largest and fastest growing transition economy in the world, China's entrance onto the global stage has been swift and dramatic. As such, almost every facet of entrepreneurship, from the identification of nascent opportunities to the challenges of managing triple-digit growth to the transformation of firms from dying to emerging industries, can be studied as natural experiments. The four papers in this issue are dedicated to exploring entrepreneurial innovation in the Chinese private economy. They include two clinical studies, one on the impact of the Beijing Olympics on entrepreneurship, and the other on the co-evolution ofguanxinetworks and entrepreneurial growth. Two studies test theories explaining the organizational drivers of innovation and entrepreneurship. In the best traditions, these four studies offer theoretical insights on the broader implications of entrepreneurship research in the Chinese context. We locate the findings offered by these four papers in the systems, organizational and social contexts of creativity, innovation, and entrepreneurship research. Finally, we offer some suggestions for future research and ways in which advances in the theoretical conversation should proceed.
Are DNA Profiles as Rare as we Think? Or Can we Trust DNA Statistics?
Authors: Curran James
Published: May 2010

DNA evidence is now widely used to link suspects to the scenes of crime. It has determined both guilt and innocence and has transformed forensic science. But there is unease. DNA identifications have been challenged in the courts. Are there too many DNA “coincidences”? Are DNA-based verdicts invalid?James Curran looks at the evidence.
Privacy or Public Good? Why not Obtaining Consent may be Best Practice
Authors: Stanley Fiona
Published: May 2010

Using medical and other data from private citizens without obtaining the consent of those citizens has been a taboo of statisticians and of society. The right to privacy is infringed; the right to confidentiality is abused. Here Fiona Stanley argues that, far from being unethical, using data without consent may be morally justified, and not using it may be a failure of duty.
A Statistician on a NICE Committee
Authors: Campbell Mike
Published: May 2010

The National Institute for Health and Clinical Excellence decides which new therapies should be allowed in the NHS. In Britain it is known as NICE. Some Americans call it a death panel. Mike Campbell works on a NICE appraisal committee. He explains what he does.
Introduction to Markov Chains – The Finite Case
Authors: Haigh John
Published: May 2010

A game of snakes and ladders, a drunkard wandering along a pavement, your car insurance no claims bonus – all of these are Markov chains. John Haigh explains what Markov meant.
Pawprints in Clay: Romano-British Dogs in a Maths Class
Authors: Musto Garrod , Cram Leslie
Published: May 2010

Two thousand years ago a dog walked across a piece of wet clay. What sort of dog?Garrod Musto, Leslie Cram and pupils of a school in Bath used statistics to find out.
Linking environmental carcinogen exposure to TP53 mutations in human tumours using the human TP53 knock‐in (Hupki) mouse model
Authors: Kucab Jill E. , Phillips David H. , Arlt Volker M.
Published: May 2010

TP53 is one of the most commonly mutated genes in human tumours. Variations in the types and frequencies of mutations at different tumour sites suggest that they may provide clues to the identity of the causative mutagenic agent. A useful model for studying human TP53 mutagenesis is the partial human TP53 knock‐in (Hupki) mouse containing exons 4–9 of human TP53 in place of the corresponding mouse exons. For an in vitro assay, embryo fibroblasts from the Hupki mouse can be examined for the generation and selection of TP53 mutations because mouse cells can be immortalized by mutation of Tp53 alone. Thus far, four environmental carcinogens have been examined using the Hupki embryo fibroblast immortalization assay: (a) UV light, which is linked to human skin cancer; (b) benzo[a]pyrene, which is associated with tobacco smoke‐induced lung cancer; (c) 3‐nitrobenzanthrone, a suspected human lung carcinogen linked to diesel exposure; and (d) aristolochic acid, which is linked to Balkan endemic nephropathy‐associated urothelial cancer. In each case, a unique TP53 mutation pattern was generated that corresponded to the pattern found in human tumours where exposure to these agents has been documented. Therefore, the Hupki embryo fibroblast immortalization assay has sufficient specificity to make it applicable to other environmental mutagens that putatively play a role in cancer aetiology. Despite the utility of the current Hupki embryo fibroblast immortalization assay, it has several limitations that could be addressed by future developments, in order to improve its sensitivity and selectivity.
In vivoproduction of catalase containing haem analogues
Authors: Brugna Myriam , Tasse Lena , Hederstedt Lars
Published: May 2010

Haem (protohaem IX) analogues are toxic compounds and have been considered for use as antibacterial agents, but the primary mechanism behind their toxicity has not been demonstrated. Using the haem protein catalase in the Gram‐positive bacteriumEnterococcus faecalisas an experimental system, we show that a variety of haem analogues can be taken up by bacterial cells and incorporated into haem‐dependent enzymes. The resulting cofactor‐substituted proteins are dysfunctional, generally resulting in arrested cell growth or death. This largely explains the cell toxicity of haem analogues. In contrast to many other organisms,E. faecalisdoes not depend on haem for growth, and therefore resists the toxicity of many haem analogues. We have exploited this feature to establish a bacterialin vivosystem for the production of cofactor‐substituted haem protein variants. As a pilot study, we produced, isolated and analysed novel catalase variants in which the iron atom of the haem prosthetic group is replaced by other metals, i.e. cobalt, gallium, tin, and zinc, and also variants containing meso‐protoheme IX, ruthenium meso‐protoporphyrin IX and (metal‐free) protoporphyrin IX. Engineered haem proteins of this type are of potential use within basic research and the biotechnical industry.

Structured digital abstract

MINT‐7722358, MINT‐7722368:katA (uniprotkb:Q834P5) and katA (uniprotkb:Q834P5) physically interact (MI:0915) by copurification (MI:0025)
Protein tandem repeats – the more perfect, the less structured
Authors: Jorda Julien , Xue Bin , Uversky Vladimir N. , Kajava Andrey V.
Published: May 2010

We analysed the structural properties of protein regions containing arrays of perfect and nearly perfect tandem repeats. Naturally occurring proteins with perfect repeats are practically absent among the proteins with known 3D structures. The great majority of such regions in the Protein Data Bank are found in the proteins designed de novo. The abundance of natural structured proteins with tandem repeats is inversely correlated with the repeat perfection: the chance of finding natural structured proteins in the Protein Data Bank increases with a decrease in the level of repeat perfection. Prediction of intrinsic disorder within the tandem repeats in the SwissProt proteins supports the conclusion that the level of repeat perfection correlates with their tendency to be unstructured. This correlation is valid across the various species and subcellular localizations, although the level of disordered tandem repeats varies significantly between these datasets. On average, in prokaryotes, tandem repeats of cytoplasmic proteins were predicted to be the most structured, whereas in eukaryotes, the most structured portion of the repeats was found in the membrane proteins. Our study supports the hypothesis that, in general, the repeat perfection is a sign of recent evolutionary events rather than of exceptional structural and (or) functional importance of the repeat residues.
Kinetic and crystallographic analyses of the catalytic domain of chitinase from Pyrococcus furiosus– the role of conserved residues in the active site
Authors: Tsuji Hiroaki , Nishimura Shigenori , Inui Takashi , Kado Yuji , Ishikawa Kazuhiko , Nakamura Tsutomu , Uegaki Koichi
Published: May 2010

The hyperthermostable chitinase from the hyperthermophilic archaeon Pyrococcus furiosus has a unique multidomain structure containing two chitin‐binding domains and two catalytic domains, and exhibits strong crystalline chitin hydrolyzing activity at high temperature. In order to investigate the structure–function relationship of this chitinase, we analyzed one of the catalytic domains (AD2) using mutational and kinetic approaches, and determined the crystal structure of AD2 complexed with chito‐oligosaccharide substrate. Kinetic studies showed that, among the acidic residues in the signature sequence of family 18 chitinases (DXDXE motif), the second Asp (D2) and Glu (E) residues play critical roles in the catalysis of archaeal chitinase. Crystallographic analyses showed that the side‐chain of the catalytic proton‐donating E residue is restrained into the favorable conformer for proton donation by a hydrogen bond interaction with the adjacent D2 residue. The comparison of active site conformations of family 18 chitinases provides a new criterion for the subclassification of family 18 chitinase based on the conformational change of the D2 residue.
Fragile X‐related protein FXR1 controls post‐transcriptional suppression of lipopolysaccharide‐induced tumour necrosis factor‐α production by transforming growth factor‐β1
Authors: Khera Tarnjit K. , Dick Andrew D. , Nicholson Lindsay B.
Published: May 2010

Tumour necrosis factor‐α (TNF‐α) is a key mediator of inflammation in host defence against infection and in autoimmune disease. Its production is controlled post‐transcriptionally by multiple RNA‐binding proteins that interact with the TNF‐α AU‐rich element and regulate its expression; one of these is Fragile X mental retardation‐related protein 1 (FXR1). The anti‐inflammatory cytokine transforming growth factor‐β1 (TGF‐β1), which is involved in the homeostatic regulation of TNF‐α, causes post‐transcriptional suppression of lipopolysaccharide (LPS)‐induced TNF‐α production. We report here that this depends on FXR1. Using RAW 264.7 cells and bone marrow‐derived macrophages (BMDMϕ) stimulated with LPS and TGF‐β1, we show that TGF‐β1 inhibits TNF‐α protein secretion, whereas TNF‐α mRNA expression remains unchanged. This response is recapitulated by the 3′‐UTR of TNF‐α, which is known to bind FXR1. TGF‐β1 induces FXR1 with a pattern of expression distinct from that of tristetraprolin, T‐cell intracellular antigen 1, or human antigen R. When FXR1 is knocked down, TGF‐β1 is no longer able to inhibit LPS‐induced TNF‐α protein production, and overexpression of FXR1 suppresses LPS‐induced TNF‐α protein production. Targeting the p38 mitogen‐activated protein kinase pathway of LPS‐treated cells with small molecule inhibitors can induce FXR1 protein and mRNA expression. In summary, TGF‐β1 opposes LPS‐induced stabilization of TNF‐α mRNA and reduces the amount of TNF‐α protein, through induction of expression of the mRNA‐binding protein FXR1.
Hydrogen peroxide efflux from muscle mitochondria underestimates matrix superoxide production – a correction using glutathione depletion
Authors: Treberg Jason R. , Quinlan Casey L. , Brand Martin D.
Published: May 2010

The production of H2O2 by isolated mitochondria is frequently used as a measure of mitochondrial superoxide formation. Matrix superoxide dismutase quantitatively converts matrix superoxide to H2O2. However, matrix enzymes such as the glutathione peroxidases can consume H2O2 and compete with efflux of H2O2, causing an underestimation of superoxide production. To assess this underestimate, we depleted matrix glutathione in rat skeletal muscle mitochondria by more than 90% as a consequence of pretreatment with 1‐chloro‐2,4‐dintrobenzene (CDNB). The pretreatment protocol strongly diminished the mitochondrial capacity to consume exogenous H2O2, consistent with decreased peroxidase capacity, but avoided direct stimulation of superoxide production from complex I. It elevated the observed rates of H2O2 formation from matrix‐directed superoxide by up to two‐fold from several sites of production, as defined by substrates and electron transport inhibitors, over a wide range of control rates, from 0.2–2.5 nmol H2O2·min−1·mg protein−1. Similar results were obtained when glutathione was depleted using monochlorobimane or when soluble matrix peroxidase activity was removed by preparation of submitochondrial particles. The data indicate that the increased H2O2 efflux observed with CDNB pretreatment was a result of glutathione depletion and compromised peroxidase activity. A hyperbolic correction curve was constructed, making H2O2 efflux a more quantitative measure of matrix superoxide production. For rat muscle mitochondria, the correction equation was: CDNB‐pretreated rate = control rate + [1.43 × (control rate)]/(0.55 + control rate). These results have significant ramifications for the rates and topology of superoxide production by isolated mitochondria.
Analysis of pressure ulcer wound fluid using two‐dimensional electrophoresis
Authors: Wyffels Jennifer T , Fries Kristin M , Randall Jason S , Ha Daniel S , Lodwig Christa A , Brogan Michael S , Shero Marlene , Edsberg Laura E
Published: May 2010

The incidence rate of pressure ulcers in the USA ranges from 0·4% to 38% in acute care settings and from 2·2% to 23·9% in long‐term care settings, and their treatment costs are in the billions of dollars yearly. The proteome of wound fluid may contain early indicators or biomarkers associated with healing in pressure ulcers that would enable treatment regimes to be optimised for each individual. Wound fluid was collected from the interior and periphery of 19 chronic pressure ulcers at 15 time points during 42 days for an analysis of protein expression. Proteins were fractionated using two‐dimensional polyacrylamide gel electrophoresis. A comparison of the spot distributions indicates a biochemical difference between the interior and the periphery of wounds. Pressure ulcers that healed show a greater number of spots for interior and peripheral locations combined over time when compared with wounds that did not heal. Using this technique, protein S100A9 was identified as a potential biomarker of wound healing. The identification of differences within the proteome of healing versus non healing pressure ulcers could have great significance in the use of current treatments, as well as the development of new therapeutic interventions.
Evolving practice of the Helsinki Skin Bank
Authors: Lindford Andrew J , Frey Ira , Vuola Jyrki , Koljonen Virve
Published: May 2010

The purpose of this study is to review the management and running of the Helsinki Skin Bank between the years 2001 and 2008. Further aims were to assess the microbiological safety of the glycerol‐preserved allograft skin and analyse its clinical use. The files of the Helsinki Skin Bank were reviewed for allograft skin harvested from organ donors between 2001 and 2008. Data on harvested skin area and microbiological culture results were collected. The patients receiving allograft were also identified and operation indications analysed. Allograft skin was collected from 115 donors, with a mean of 44 335 cm2 per year. No skin batches were discarded. Microbiological cultures of the allograft skin batches were negative in 86 (75%) cases. Thirty‐five donor skin batches were used in 69 operations. The most common indication was ‘Biological dressing on partial‐thickness burns', comprising 52% of cases. The cost per cm2 was 0.81€. The use of allograft skin in the Helsinki Skin Bank is microbiologically safe and continues to provide a versatile and useful treatment modality in many major burn cases with few observed complications. As compared with synthetically produced temporary dressings currently available, our allograft skin is also more economical.
Limiting angiotensin II signaling with a cell‐penetrating peptide mimicking the second intracellular loop of the angiotensin II type‐I receptor
Authors: Yu Jun , Taylor Linda , Mierke Dale , Berg Eric , Shia Michael , Fishman Jordan , Sallum Christine , Polgar Peter
Published: May 2010

A cell‐penetrating peptide consisting of the second intracellular loop (IC2) of the angiotensin II (AngII) type‐I receptor (AT1) linked to the HIV‐transactivating regulatory protein (TAT) domain was used to identify the role of this motif In intracellular signal transduction. HEK‐293 cells stably transfected with AT1R cDNA and primary cultures of human pulmonary artery smooth muscle cells expressing endogenous AT1 receptor were exposed to the cell‐penetrating peptide construct, and the effect on angiotensin II signaling was determined. The AT1 IC2 peptide effectively inhibited AngII‐stimulated phosphatidylinositol turnover and calcium influx. It also limited the activation of Akt/PKB as determined by an inhibition of phosphorylation of Akt at Ser473, and completely abolished the AngII‐dependent activation of the transcriptional factor NFκB. In contrast, the AT1 IC2 peptide had no effect on AngII/AT1 receptor activation of ERK. These results illustrate the potential of using cell‐penetrating peptides to both delineate receptor‐mediated signal transduction and to selectively regulate G protein‐coupled receptor signaling.
Effect of Indian mustard on feeding, larval survival and development of Plutella xylostella at constant temperatures
Authors: ANSARI M. Shafiq , AHMAD Tufail , ALI Haidar
Published: May 2010

Feeding behavior of Plutella xylostella under optional to non‐optional conditions was studied at 10°C, 15°C, 20°C, and 25°C on Indian mustard, Brassica juncea. The study reveals that the variety Pusa Bahar was significantly less preferred by the larvae as compared with Pusa Bold and Varuna under optional to non‐optional conditions. Larvae of P. xylostella consumed more food at 25°C than 20°C, 15°C and 10°C. Larval survival was found to be highest on cabbage (control) as compared with Indian mustard and was found to vary with host plants and temperature. The larval survival decreased to 11.29% on Pusa Bahar at 10°C. Increasing the temperature from 10°C to 20°C, larval mortality resulted more on Varuna than Pusa Bahar and Pusa Bold. Developmental period was prolonged on Pusa Bold at 10°C while it was shortest on cabbage at 25°C. A total of 536.47 degree days were required to complete the development by immature stages on Varuna at 25°C and 421.64 degree days on cabbage.
Genetics of resistance to Cry1C toxin from Bacillus thuringiensis in Spodoptera litura (Fab.)
Authors: THAKARE Atul S. , BARKHADE Umesh P. , PAWADE Vrushali N. , THAKARE Shivcharan M.
Published: May 2010

The present study was undertaken to determine the genetics of Cry1C resistance in Spodoptera litura. Selection of S. litura (Fab.) with Cry1C was done for eight generations to develop resistance. Reciprocal crosses between resistant and susceptible populations were made to understand the population genetics of Cry1C resistance in S. litura. Generation wise selection with Cry1C was evaluated for resistance development in S. litura. The LC50 of Cry1C was 0.14 µg/cm2 for the first selected generation and it increased to 23.98 µg/cm2 after eight selected generations, which is a 285.47‐fold increase in resistance compared with the susceptible strain. The estimated realized heritability (h2) after eight generations of selection with Cry1C insecticidal protein was 0.44. The number of generations required for the tenfold increase in LC50 (1/R) was estimated to be 3.33. Response to Cry1C selection in S. litura was 0.30, the estimated selection differential was 0.69 and the pheonotypic standard deviation (dP) was 0.24. Reciprocal crosses between Cry1C resistant and susceptible strain of S. litura showed autosomal resistance.
Two‐dimensional gel analysis of stress proteins identified inChironomus flaviplumus(Diptera: Chironomidae) exposed to 4‐nonylphenol
Authors: KIM Myoung Chul , HAN Sung Sik
Published: May 2010

Toxicity of 4‐nonylphenol (4‐NP) in the ChironomidaeChironomus flaviplumuswas analyzed using a proteomics approach that involved identifying proteins by two‐dimensional polyacrylamide gel electrophoresis (2‐D PAGE). Proteome analysis of 4‐NP‐treated samples on silver stained gels found alterations in the expression levels of three proteins compared with control samples. Hsp70 proteins, so‐called stress proteins, were studied inChironomus flaviplumusexposed to different concentrations of 4‐nonylphenol (0, 30, 100, 150, 300 and 600 mg/L) in the laboratory and in the field in captured animals from site 1 (1 km from a chemical factory) and site 3 (16 km from a chemical factory). Hsp70 proteins were found in all samples tested, including controls, but differed in their expression levels. At more polluted sites (site 1), the samples treated with higher concentrations of 4‐NP more strongly expressed Hsp70. 2‐D spots were induced or enhanced in gels following injection of 4‐NP. Therefore, the induction of stress protein expression inChironomus flaviplumus,in particular Hsp70, can be used as a biomarker for the evaluation of environmental conditions.
New species and two new records of the spider family Theridiidae (Araneae) from Korea
Authors: SEO Bo Keun
Published: May 2010

Three theridiid spiders, which are a new species, Neospintharus baekamensis n. sp., and two species new to Korea, Cryptachaea riparia (Blackwall, 1834) and Lasaeola yoshidai (Ono et al., 1991), are described. The illustrations and diagnoses for all of the species are also provided.
Inflation Uncertainty and Monetary Policy in China
Authors: Zhang Chengsi
Published: May 2010

This paper uses a stochastic volatility model, structural break tests with unknown point, and a counterfactual simulation method to discuss the significant decline in inflation uncertainty in China over 1978–2009. We attempt to quantify the contributions of better monetary policy and smaller structural shocks (including demand, supply and policy impacts) on the reduced inflation uncertainty. Empirical results in the present paper suggest that improved monetary policy accounts for only a small fraction of the reduction in inflation uncertainty from the pre‐1997 period to the post‐1997 period in China. The bulk of the significant moderation in inflation uncertainty arises from smaller shocks. This finding indicates that the quiescence of inflation in China over the past decade could well be followed by a return to a more turbulent inflation era. Therefore, the use of preemptive monetary policy to anchor inflationary expectations and keep moderate inflation uncertainty is warranted.
China and the Global Financial Crisis: Assessing the Impacts and Policy Responses
Authors: Liang Yan
Published: May 2010

The present paper explores the role of China in the creation of the current global financial crisis and the impacts of the crisis on its economy. It argues against the view that the “saving glut” in China (along with other Asian emerging economies) played a significant causal role in the crisis. The global financial crisis did not engender much damage in China's financial structure, thanks to the relatively closed, bank‐centered financial system. However, the impacts on the “real” side of the Chinese economy were hard felt. Growth and employment have fallen, largely due to the decline in exports and foreign direct investment. The crisis reveals the vulnerability of the export‐dependent growth pattern. Policy responses of the Chinese Government, including monetary, fiscal and social policies, have helped to stem the downfall of the economy in the immediate term, but some of the policies have not addressed the structural problems of the Chinese economy and might well aggravate such problems over time. The present paper proposes a tentative reform blueprint to rebalance the economy and to sustain long‐term growth.
Regional Environmental Performance and Its Determinants in China
Authors: Wu Yanrui
Published: May 2010

A growing awareness of environmental quality has placed increased pressure on China to improve environmental protection and regulations in the country. How have the regional economies in the country performed in terms of environmental efficiency? The answer to this question is yet to be explored in the case of China. The objective of this paper is to present a quantitative analysis of environmental performance in China's regional economies and to examine the determinants of regional variation in performance. The findings are used to draw policy implications for environmental protection and are helpful in the discussion of China's future sustainable development.
Restructuring in China's State‐owned Enterprises: Evidence from the Coal Industry
Authors: Shi Xunpeng
Published: May 2010

Using firm‐level data for China's state‐owned coal mines, this paper examines the impact of privatization, corporatization and debt restructuring of state‐owned enterprises on technical efficiency. A stochastic frontier production method is applied to a panel dataset from 2000 to 2007. The simultaneous study of these three measures makes it possible to study individual effects more precisely than otherwise. The study shows that the three reform initiatives are all able to improve technical efficiency in state‐owned coal mines. The finding of a significant efficiency improvement from relinquishing state ownership provides an alternative to privatization. The study of debt restructuring and technical efficiency has not been documented in the published literature.