420 research outputs found
3D FEM simulation of the flow forming process using Lagrangian and ALE methods
Reprinted with permission from AIP Conf. Proc.May 17, 2007 -- Volume 908, pp. 257-262 MATERIALS PROCESSING AND DESIGN; Modeling, Simulation and Applications; NUMIFORM '07; Proceedings of the 9th International Conference on Numerical Methods in Industrial Forming Processes; doi:10.1063/1.2740821 Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of PhysicsInternational audienceThe process of flow forming is numerically modeled using finite element codes based on the Forge2005® software. Two numerical approaches are considered. The first one uses an updated Lagrangian formulation. The problem is solved with help of a self-contact management algorithm. The second approach consists in using an ALE formulation that permits to optimize meshing with an adaptive method based on the Zienkiewicz-Zhu error estimation. The ALE method is well adapted to incremental forming processes such as flow forming and allows dealing with difficulties generated by the contact between the work piece and tools. Both formulations are coupled with complex tool kinematics. The Lagrangian formulation gives realistic results. The ALE formulation is promising with regard to computational time, and simulations on simple configurations show fairly good agreements with Lagrangian results
Characterisation of mixed virus infections in Ribes species in Switzerland
Various virus disease-like symptoms are frequently observed in Ribes sp. in Switzerland but the aetiology remains poorly documented, although a number of viruses infecting Ribes sp. were described elsewhere. Therefore, symptomatic and apparently healthy plants from diverse origins were analysed by electron microscopy (EM), immunoprecipitation electron microscopy (IPEM), Western blot and (RT-)PCR. By EM, at least four different particle types, often in combination, were observed. (1) Bacilliform particles were typical for the Badnavirus genus with dimensions of 145 x 28 nm. This virus was identified by PCR as the Gooseberry vein banding associated virus (GVBaV). (2) Filamentous particles were mainly observed on black currants with downward rolling of leaves with interveinal reddening during summer and fall. We tentatively named this unknown virus Blackcurrant leafroll-associated virus 1 (BCLRaV-1). In phylogenetic analysis of HSP70h nucleotide sequences, BCLRaV-1 felt in the Closterovirus genus. In Western blot analysis, one dominant protein with an estimated molecular weight of about 28 kDa was detectable. The virus was shown to be different from the Raspberry mottle closterovirus (RMoV) by IPEM and RT-PCR. (3) RTPCR and sequencing of products also clearly demonstrated the presence in our Ribes samples of Rubus chlorotic mottle virus (RuCMV), a Sobemovirus recently described in Scotland. This finding correlates with the presence of the 30 nm diameter particles observed by EM. (4) A further structure with isometrical particles of 60 nm could not yet be attributed to a particular genus. Altogether, our data suggest the presence of multiple virus infections i
A cross-sectional study on nutrient intake and -status in inflammatory bowel disease patients.
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This article is open access.Inflammatory bowel disease (IBD) can be associated with nutritional problems. The aim of this study was to investigate diet and nutritional status of IBD patients.A total of 78 participants (35 men and 43 women aged 18-74 years) were included in this cross-sectional study. The majority (80 %) of the participant received infliximab treatment. Participants filled out disease related questionnaires and 31 participants also a 3-day food record. Body composition was measured and blood samples analysed in order to estimate nutritional status.The majority (87 %) claimed that diet affects digestive tract symptoms and 72 % had changed diet accordingly. The most common foods restricted were dairy products (60 %), processed meat (55 %), soft drinks (46 %), alcohol (45 %) and fast food (44 %). Body mass index was mostly in the overweight range but 46 % of the participants had been diagnosed with some nutritional deficiency since IBD diagnosis (most common was iron deficiency: 39 %). Patients who restricted meat products had lower ferritin values (48 ± 39 vs. 95 ± 74 μg/L, P = 0.011). Intake of vitamin D and calcium were not adequate (65 % below recommeded intake for both) and 60 % had poor vitamin D status.IBD patients often change their dietary intake in order to affect digestive tract symptoms. Many patients have a history of nutrient deficiency. Restriction of dairy and meat consumption is common and is negatively associated with intake or status of micronutrients like calcium and iron. Dietary advice by a dietitian and use of potentially helpful dietary supplements is indicated.Science funds of the Landspitali- The National University Hospital of Icelan
The sarcopenia and physical frailty in older people : multi-component treatment strategies (SPRINTT) project: description and feasibility of a nutrition intervention in community-dwelling older Europeans
Background The "Sarcopenia and Physical Frailty in Older People: Multicomponent Treatment Strategies" (SPRINTT) project sponsored a multi-center randomized controlled trial (RCT) with the objective to determine the effect of physical activity and nutrition intervention for prevention of mobility disability in community-dwelling frail older Europeans. We describe here the design and feasibility of the SPRINTT nutrition intervention, including techniques used by nutrition interventionists to identify those at risk of malnutrition and to carry out the nutrition intervention. Methods SPRINTT RCT recruited older adults (>= 70 years) from 11 European countries. Eligible participants (n = 1517) had functional limitations measured with Short Physical Performance Battery (SPPB score 3-9) and low muscle mass as determined by DXA scans, but were able to walk 400 m without assistance within 15 min. Participants were followed up for up to 3 years. The nutrition intervention was carried out mainly by individual nutrition counseling. Nutrition goals included achieving a daily protein intake of 1.0-1.2 g/kg body weight, energy intake of 25-30 kcal/kg of body weight/day, and serum vitamin D concentration >= 75 mmol/L. Survey on the method strategies and feasibility of the nutrition intervention was sent to all nutrition interventionists of the 16 SPRINTT study sites. Results Nutrition interventionists from all study sites responded to the survey. All responders found that the SPRINTT nutrition intervention was feasible for the target population, and it was well received by the majority. The identification of participants at nutritional risk was accomplished by combining information from interviews, questionnaires, clinical and laboratory data. Although the nutrition intervention was mainly carried out using individual nutritional counselling, other assisting methods were used as appropriate. Conclusion The SPRINTT nutrition intervention was feasible and able to adapt flexibly to varying needs of this heterogeneous population. The procedures adopted to identify older adults at risk of malnutrition and to design the appropriate intervention may serve as a model to deliver nutrition intervention for community-dwelling older people with mobility limitations. Aim To describe the methods and feasibility of the nutritional intervention carried out within the SPRINTT Randomized cotrolled trial. We also illustrate how nutrition interventionists identified participants at risk of malnutrition and the lessons learnt from the nutrition intervention. Findings SPRINTT nutrition intervention was well-received by the majority of the participants. It was mainly carried out using tailored nutrition counselling, but also other means of delivering the intervention were successfully used. Compared with a standard nutrition prescription, an individualized protocol to diagnose malnutrition and follow-up by tailored nutrition counselling helped achieve nutritional targets more effectively in spite of diversity of population in nutritional habits and in some cases reluctance to accept changes. Message The SPRINTT nutrition intervention was feasible and allowed flexibility to the varying needs and cultural differences of this heterogeneous population of frail, older Europeans. It may serve as a model to educate and improve nutrition among community-dwelling older people at risk of mobility limitations.Peer reviewe
A New Class of Small Molecule Inhibitor of BMP Signaling
Growth factor signaling pathways are tightly regulated by phosphorylation and include many important kinase targets of interest for drug discovery. Small molecule inhibitors of the bone morphogenetic protein (BMP) receptor kinase ALK2 (ACVR1) are needed urgently to treat the progressively debilitating musculoskeletal disease fibrodysplasia ossificans progressiva (FOP). Dorsomorphin analogues, first identified in zebrafish, remain the only BMP inhibitor chemotype reported to date. By screening an assay panel of 250 recombinant human kinases we identified a highly selective 2-aminopyridine-based inhibitor K02288 with in vitro activity against ALK2 at low nanomolar concentrations similar to the current lead compound LDN-193189. K02288 specifically inhibited the BMP-induced Smad pathway without affecting TGF-β signaling and induced dorsalization of zebrafish embryos. Comparison of the crystal structures of ALK2 with K02288 and LDN-193189 revealed additional contacts in the K02288 complex affording improved shape complementarity and identified the exposed phenol group for further optimization of pharmacokinetics. The discovery of a new chemical series provides an independent pharmacological tool to investigate BMP signaling and offers multiple opportunities for pre-clinical development
Borderline personality traits, rumination and self-injurious behavior: An empirical test of the emotional cascades model in adult male offenders
The aim of the study was to examine whether the emotional cascade model, which suggests that the relationship between emotional and behavioural dysregulation in Borderline Personality Disorder (BPD) is mediated by rumination, applies to a sample of adult male offenders. The study focused on individuals with “BPD traits” and two dysregulated behaviors that are particularly relevant to the prison population: non-suicidal self-injury (NSSI) and suicidality. Participants were 179 adult male offenders detained in a medium-secure prison, all of whom completed a battery of measures and self-reported their actual prison behaviour. The results support the application of the emotional cascade model to adult male offenders, suggesting that emotional cascades may play an important role in NSSI and suicidality in this population, although this relationship needs further exploration. These findings highlight the benefits of targeting rumination to manage risk of NSSI and suicidality within custodial settings
A randomized controlled clinical trial comparing small buccal dehiscence defects around dental implants treated with guided bone regeneration or left for spontaneous healing
PURPOSE The aim of the present randomized controlled clinical study was to test whether small bony dehiscence defects (≤5 mm) left to heal spontaneously result in the same clinical and radiological outcome as defects treated with guided bone regeneration (GBR). MATERIALS AND METHODS Twenty-two patients who received at least one implant with a small bony dehiscence defect were enrolled in the study. If the defect height was ≤5 mm, the site was randomly assigned to either the spontaneous healing (SH) group or the GBR group. In the SH group, the defect was left without any treatment. In the GBR group, the defects around the implants were grafted with deproteinized bovine bone mineral (DBBM) and covered with a native collagen membrane. Clinical and radiographic measurements were performed 6 months after implant placement with a reentry surgery and at the time of crown insertion and the subsequent follow-up appointments at 3, 6, 12 and 18 months after loading. For statistical analyses, the mixed linear model was applied for the clinical and radiographic measurements observed around the implants. Simple comparisons of the location of the measurements in the two independent groups are performed with the Mann-Whitney U-test. In addition, the mixed model assumptions were checked. RESULTS The implant and crown survival rate 18 months after loading was 100%, revealing no serious biologic or prosthetic complication. The mean changes of the buccal vertical bone height between implant placement and reentry surgery after 6 months revealed a small bone loss of -0.17 ± 1.79 mm (minimum -4 mm and maximum 2.5 mm) for the SH group and a bone gain of 1.79 ± 2.24 mm (minimum of -2.5 mm and maximum of 5 mm) for the GBR group, respectively (P = 0.017). Radiographic measurements demonstrated a slight bone loss of -0.39 ± 0.49 mm for the SH group and a stable bone level of 0.02 ± 0.48 mm for GBR group after 18 months. All peri-implant soft tissue parameters revealed healthy tissues with no difference between the two groups. CONCLUSION Small bony dehiscence defects left for spontaneous healing demonstrated high implant survival rates with healthy and stable soft tissues. However, they revealed more vertical bone loss at the buccal aspect 6 months after implant insertion and also more marginal bone loss between crown insertion and 18 months after loading compared to sites treated with GBR
Carbon Dynamics, Development and Stress Responses in Arabidopsis: Involvement of the APL4 Subunit of ADP-Glucose Pyrophosphorylase (Starch Synthesis)
An Arabidopsis thaliana T-DNA insertional mutant was identified and characterized for enhanced tolerance to the singlet-oxygen-generating herbicide atrazine in comparison to wild-type. This enhanced atrazine tolerance mutant was shown to be affected in the promoter structure and in the regulation of expression of the APL4 isoform of ADP-glucose pyrophosphorylase, a key enzyme of the starch biosynthesis pathway, thus resulting in decrease of APL4 mRNA levels. The impact of this regulatory mutation was confirmed by the analysis of an independent T-DNA insertional mutant also affected in the promoter of the APL4 gene. The resulting tissue-specific modifications of carbon partitioning in plantlets and the effects on plantlet growth and stress tolerance point out to specific and non-redundant roles of APL4 in root carbon dynamics, shoot-root relationships and sink regulations of photosynthesis. Given the effects of exogenous sugar treatments and of endogenous sugar levels on atrazine tolerance in wild-type Arabidopsis plantlets, atrazine tolerance of this apl4 mutant is discussed in terms of perception of carbon status and of investment of sugar allocation in xenobiotic and oxidative stress responses
Prior exercise and antioxidant supplementation: effect on oxidative stress and muscle injury
<p>Abstract</p> <p>Background</p> <p>Both acute bouts of prior exercise (preconditioning) and antioxidant nutrients have been used in an attempt to attenuate muscle injury or oxidative stress in response to resistance exercise. However, most studies have focused on untrained participants rather than on athletes. The purpose of this work was to determine the independent and combined effects of antioxidant supplementation (vitamin C + mixed tocopherols/tocotrienols) and prior eccentric exercise in attenuating markers of skeletal muscle injury and oxidative stress in resistance trained men.</p> <p>Methods</p> <p>Thirty-six men were randomly assigned to: no prior exercise + placebo; no prior exercise + antioxidant; prior exercise + placebo; prior exercise + antioxidant. Markers of muscle/cell injury (muscle performance, muscle soreness, C-reactive protein, and creatine kinase activity), as well as oxidative stress (blood protein carbonyls and peroxides), were measured before and through 48 hours of exercise recovery.</p> <p>Results</p> <p>No group by time interactions were noted for any variable (P > 0.05). Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P < 0.0001). Protein carbonyls and peroxides were relatively unaffected by exercise.</p> <p>Conclusion</p> <p>There appears to be no independent or combined effect of a prior bout of eccentric exercise or antioxidant supplementation as used here on markers of muscle injury in resistance trained men. Moreover, eccentric exercise as used in the present study results in minimal blood oxidative stress in resistance trained men. Hence, antioxidant supplementation for the purpose of minimizing blood oxidative stress in relation to eccentric exercise appears unnecessary in this population.</p
Bird-spiders (Arachnida, Mygalomorphae) as perceived by the inhabitants of the village of Pedra Branca, Bahia State, Brazil
This paper deals with the conceptions, knowledge and attitudes of the inhabitants of the county of Pedra Branca, Bahia State, on mygalomorph spiders locally known as 'caranguejeiras' (bird-spiders). It is launched here a new filed within ethnozoology: ethnoarachnology, which is defined as the transdisciplinary study of the relationships between human beings and bird-spiders. Data were collected from February to June 2005 by means of open-ended interviews carried out with 30 individuals, which ages ranged from 13 to 86 years old. It was recorded some traditional knowledge regarding the following items: taxonomy, biology, habitat, ecology, seasonality, and behavior. Results show that bird-spiders are classified as "insects". The most commented aspect of the interaction between bird-spiders and inhabitants of Pedra Branca is related to their dangerousness, since they said these spiders are very venomous and can cause health problems. In general, the traditional zoological knowledge of Pedra Branca's inhabitants concerning these spiders is coherent with the academic knowledge
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