WHEEL GYMNASTICS· SOMERSAULT DISMOUNTS AND NO LANDING MAT

The aim of this study was to investigate which biomechanical principles act during salto dismounts from the gymwheel and in wllich way the load dUring landing can be reduced. For this purpose a forward and a backward somersault dismount from straight-line voluntary routines were studied. The movement of the gymnast and the wheel were analyzed with a 3D photogrammetric procedure. Flight height and salto angular momentum can be increased if the take-off is improved. For example, the wheel velocity has to decelerated during the take-off to zero in order to transmit a bigger amount of energy back to the gymnast. The maximum loads while landing from approx. 2.50 m height on the hard ground can be reduced by suitable movements of the body segments. But we recommend to the I.R.V., though, to introduce landing mats in the straight-line discipline too

The haematopoietic GTPase RhoH modulates IL3 signalling through regulation of STAT activity and IL3 receptor expression

<p>Abstract</p> <p>Background</p> <p>RhoH is a constitutively active member of the family of Rho GTPases. Its expression is restricted to the haematopoietic lineage, where it serves as a positive regulator for T cell selection and mast cell function and as a negative regulator for growth-related functions in other lineages. Here, we examined the activation of signal transducer and activator of transcription (STAT) proteins in response to stimulation with interleukin 3 (IL3).</p> <p>Results</p> <p>Using the murine IL3-dependent cell line BaF3 we investigated the influence of RhoH protein expression levels on IL3-mediated cellular responses. RhoH overexpressing cells showed lower sensitivity to IL3 and decreased STAT5 activation. SiRNA-mediated repression of <it>RhoH </it>gene expression led to an increase in proliferation and STAT5 activity which correlated with an increased number of IL3 receptor α chain molecules, also known as CD123, expressed at the cell surface. Interestingly, these findings could be reproduced using human THP-1 cells as a model system for acute myeloid leukaemia, where low RhoH levels are known to be an unfavourable prognostic marker. Overexpression of RhoH on the other hand caused an induction of STAT1 activity and western blot analysis revealed that activated STAT1 is phosphorylated on Tyr701. STAT1 is known to induce apoptosis or cell cycle arrest and we detected an upregulation of cyclin-dependent kinase inhibitors (CDKI) <it>p21^Cip1</it>and <it>p27^Kip1</it>in RhoH overexpressing BaF3 cells.</p> <p>Conclusions</p> <p>We propose that RhoH functions as a negative regulator for IL3-induced signals through modulation of the JAK-STAT pathway. High levels of RhoH allow the IL3-dependent activation of STAT1 causing decreased proliferation through upregulation of <it>p21^Cip1</it>and <it>p27^Kip1</it>. Low RhoH levels on the other hand led to an upregulation of IL3-dependent cell growth, STAT5 activity and an increase of CD123 surface expression, linking RhoH to a CD123/STAT5 phenotype that has been described in AML patients.</p

SK 1: A Possible Case of Triggered Star Formation in Perseus

According to a triggered star formation scenario (e.g. Martin-Pintado & Cernicharo 1987) outflows powered by young stellar objects shape the molecular clouds, can dig cavities, and trigger new star formation. NGC 1333 is an active site of low- and intermediate star formation in Perseus and is a suggested site of self-regulated star formation Norman & Silk 1980. Therefore it is a suitable target for a study of triggered star formation (e.g. Sandell & Knee 2001, SK 1). On the other hand, continuum sub-mm observations of star forming regions can detect dust thermal emission of embedded sources (which drive outflows), and further detailed structures. Within the framework of our wide-field mapping of star formation regions in the Perseus and Orion molecular clouds using SCUBA at 850 and 450 micrometers, we map NCG 1333 with an area of around 14' x 21'. The maps show more structure than the previous maps of the region observed in sub-mm. We have unveiled the known embedded SK 1 source (in the dust shell of the SSV 13 ridge) and detailed structure of the region, among some other young protostars. In agreement with the SK 1 observations, our map of the region shows lumpy filaments and shells/cavities that seem to be created by outflows. The measured mass of SK 1 (~0.07 Msun) is much less than its virial mass (~0.2-1 Msun). Our observations support the idea of SK 1 as an event triggered by outflow-driven shells in NGC 1333 (induced by an increase in gas pressure and density due to radiation pressure from the stellar winds, that have presumably created the dust shell). This kind of evidences provides a more thorough understanding of the star formation regulation processes.Comment: 5 pages, 1 Postscript figure. Contributed paper delivered at IAU Symposium 237 "Triggered Star Formation in a Turbulent ISM", Bruce Elmegreen and Jan Palous (eds.

Helicobacter pylori Infection in the Young in Bangladesh: Prevalence, Socioeconomic and Nutritional Aspects

Background The gastric acid barrier, an important host defence against small bowel infection, may be compromised by infection with Helicobacter pylori. In developing countries, H.pylori infection occurs early in life and prevelance of hypochlorhydria is high particularly in the malnourished, which may predispose a child to repeated gastrointestinal Infection and diarrhoea. Diarrhpea being a leading cause a childhood mortality and morbidity in developing countries, we investigated the prevelance of H. pylori infection in children in poor Bangladeshi community and explored its association with socioeconomic and nutritional status. Methods The study was conducted in a poor periurban community among 469 children aged -99months. Parents were interviewed ising a questionnaire. To detect active infection with H. pyloria13 C-urea broath test was performed and weight was recorded on a beam balance with a sensitivity of 20g. Results In all, 61% of 36 infants aged 1-3 months were positive for H. pylori, this rate dropped steadily with increasing age and was 33% in 10-15 month old children and then rose to 84% in 6-9 year olds. Overall H. pylori infection had no association with nutritional state of the child or family income but the infection rate was 2.5 times higher in children of mothers with no schooling. Conclusions The H. pylori infection rate is very high in early infancy in a poor periurban community of Bangladesh. The reason for a drop in the infection rate infancy is unclear but could be due to initial clearance of the infection by the body's defence mechanisms but with possible alteration of the gastric mucosa which sustains infection. Maternal education may be protective and may operate through some underlined proximate behavioural determinants. The rate of H. pylori infection and young children may predispose them to reapeated gastrointestinal infection and diahorrea

Open Posterior Reduction and Stabilization of AO Spine C3 Sacral Fractures.

AO Spine C3 sacral fractures are defined by separation of the spine including S1 from the pelvic ring and are usually result of a high-energy injury. Besides their high biomechanical instability and high rate of associated neurological impairment, these fractures are often extremely difficult to reduce due to severe bony impaction and dislocation. Additional difficulties in management of these fractures arise from only a thin-layer of soft-tissue coverage overlying the injured area

Helicobacter pylori Colonization in Infants and Young Children is Not Necessarily Associated with Diarrhoea

A cohort of 151 infants and young children aged 1-23 months from a poor peri-urban community of Bangladesh was studied to determine the relationship between Helicobacter pylori colonization and morbidity due to diarrhoea. A 13C urea breath test was performed to detect the presence of H. pylori.Children were followed up at home every alternate day for 6 months and diarrhoeal morbidity datawere collected. Diarrhoeal morbidity was compared between H. pylori-positive and H. pylori-negative children. Sixty-eight (45 per cent) children were H. pylori positive and 83 (55 per cent) were H. pylori negative. During the first 1-month period following the breath test, three (4.4 per cent) H. pylori-positive and four (4.8 per cent) H. pylori-negative children had diarrhoea. Thirty-two (47 per cent) of the children in the positive group and 43 (52 per cent) in the negative group had one or more episodesof diarrhoea during the 6-month follow-up period. Median number of diarrhoeal episodes was 1.0(range 1.0-4.0) in the H. pylori-positive children and 2.0 (range 1.0-5.0) in the H. pylori-negativechildren (p = 0.19). No significant difference was observed in the cumulative days with diarrhoea.The results of this study suggest that H. pylori colonization is not associated with diarrhoealmorbidity in infants and young childre

In vitro degradation and mechanical properties of PLA-PCL copolymer unit cell scaffolds generated by two-photon polymerization

The manufacture of 3D scaffolds with specific controlled porous architecture, defined microstructure and an adjustable degradation profile was achieved using two-photon polymerization (TPP) with a size of 2  ×  4  ×  2 mm3. Scaffolds made from poly(D,L-lactide-co-ɛ-caprolactone) copolymer with varying lactic acid (LA) and ɛ -caprolactone (CL) ratios (LC16:4, 18:2 and 9:1) were generated via ring-opening-polymerization and photoactivation. The reactivity was quantified using photo-DSC, yielding a double bond conversion ranging from 70% to 90%. The pore sizes for all LC scaffolds were see 300 μm and throat sizes varied from 152 to 177 μm. In vitro degradation was conducted at different temperatures; 37, 50 and 65 °C. Change in compressive properties immersed at 37 °C over time was also measured. Variations in thermal, degradation and mechanical properties of the LC scaffolds were related to the LA/CL ratio. Scaffold LC16:4 showed significantly lower glass transition temperature (T g) (4.8 °C) in comparison with the LC 18:2 and 9:1 (see 32 °C). Rates of mass loss for the LC16:4 scaffolds at all temperatures were significantly lower than that for LC18:2 and 9:1. The degradation activation energies for scaffold materials ranged from 82.7 to 94.9 kJ mol−1. A prediction for degradation time was applied through a correlation between long-term degradation studies at 37 °C and short-term studies at elevated temperatures (50 and 65 °C) using the half-life of mass loss (Time (M1/2)) parameter. However, the initial compressive moduli for LC18:2 and 9:1 scaffolds were 7 to 14 times higher than LC16:4 (see 0.27) which was suggested to be due to its higher CL content (20%). All scaffolds showed a gradual loss in their compressive strength and modulus over time as a result of progressive mass loss over time. The manufacturing process utilized and the scaffolds produced have potential for use in tissue engineering and regenerative medicine applications

Project incomat connectiong biomaterial experts. What about Croatia?

Život milijuna ljudi diljem svijeta poboljšan je ugradnjom neke vrste implanta. Potražnja za novim vrstama implant materijala, kao i starim, poboljšanih svojstava, svakodnevno raste. Stoga ne iznenađuje i stalni porast broja istraživačkih skupina koje se bave istraživanjem, izradom i primjenom biomaterijala. Unatoč tome prisutan je veliki jaz između SAD-a, zemalja EU i zemalja trećega svijeta koje do sada nisu bile uključene u istraživački prostor EU. Cilj je specifične potporne akcije u sklopu FP6 projekta INCOMAT savladavanje toga jaza, na području biomaterijala za regeneraciju čvrstoga tkiva, osnivanjem timova izvrsnosti sastavljenih od stručnjaka iz zemalja EU, trećega svijeta i SAD-a.Lives of millions of people worldwide have been improved by application of some kind of implant. The need for new implant materials, as well as old ones with improved properties has been growing constantly. The number of groups dealing with biomaterials has also been growing constantly. Nevertheless, there is a huge gap between developed and third world countries (including Western Balkan countries, newly independent states), which up to now have not been involved in the European Research Area. The goal of FP6 specific support action - project INCOMAT is to bridge this gap in the field of hard tissue implant materials by forming teams of excellence, which will include experts from USA, EU countries and third world countries