EFFECT OF AGE ON HIGH JUMP TAKEOFF BIOMECHANICS

The aim of the study was to analyse the differences in critical features of high jump take-off in different ages. 3D photogrammetry was used to analyse the best jump of the participants of 3 Spanish Indoor Championships (2009) (13-15 y, 17-18 y, and 18-34 y). The variables measured were horizontal velocity of the centre of mass (CM) at touchdown (VH0), knee angle at touchdown (K0), leg angle at touchdown (L0); height of the CM at touchdown (H0); and take-off angle (TOA). The three groups were compared with ANOVA and each variable was correlated with the maximum CM height. Statistical differences were found in VH0 and H0, but not in the variables directly related to the take-off technique. It is concluded that younger athletes use similar techniques than older ones. This might be a wrong strategy, as they should adapt it to their maturity limitations

A HEV-restricted sulfotransferase is expressed in rheumatoid arthritis synovium and is induced by lymphotoxin-alpha/beta and TNF-alpha in cultured endothelial cells.

BackgroundThe recruitment of lymphocytes to secondary lymphoid organs relies on interactions of circulating cells with high endothelial venules (HEV). HEV are exclusive to these organs under physiological conditions, but they can develop in chronically-inflamed tissues. The interaction of L-selectin on lymphocytes with sulfated glycoprotein ligands on HEV results in lymphocyte rolling, which represents the initial step in lymphocyte homing. HEV expression of GlcNAc6ST-2 (also known as HEC-GlcNAc6ST, GST-3, LSST or CHST4), an HEV-restricted sulfotransferase, is essential for the elaboration of L-selectin functional ligands as well as a critical epitope recognized by MECA-79 mAb.ResultsWe examined the expression of GlcNAc6ST-2 in relationship to the MECA-79 epitope in rheumatoid arthritis (RA) synovial vessels. Expression of GlcNAc6ST-2 was specific to RA synovial tissues as compared to osteoarthritis synovial tissues and localized to endothelial cells of HEV-like vessels and small flat-walled vessels. Double MECA-79 and GlcNAc6ST-2 staining showed colocalization of the MECA-79 epitope and GlcNAc6ST-2. We further found that both TNF-alpha and lymphotoxin-alphabeta induced GlcNAc6ST-2 mRNA and protein in cultured human umbilical vein endothelial cells.ConclusionThese observations demonstrate that GlcNAc6ST-2 is induced in RA vessels and provide potential cytokine pathways for its induction. GlcNAc6ST-2 is a novel marker of activated vessels within RA ectopic lymphoid aggregates. This enzyme represents a potential therapeutic target for RA

EFFECTS OF DIFFERENT RESISTED SPRINT RUNNING METHODS ON STRIDE LENGTH, STRIDE FREQUENCY, AND CG VERTICAL OSCILLATION

Sprint velocity can be increased thanks to specific strength improvements (Korchemny, 1985). The training principle of specificity states that for a training session to be effective, it must maintain similar characteristics to the sport requirements (Sale, 2003). With the use of resisted sprint running methods, possible benefits are specific strength improvements and an increase in stride length (Faccioni, 1994). However, these methods have not been scientifically proven yet (Sheppard, 2004)

Kinematic, strength, and stiffness adaptations after a short-term sled towing training in athletes

One of the most frequently used methods for training the sprint‐specific strength is the sled towing. To date, no studies have been conducted to explore the effects of this method after a training period in well‐trained athletes. The purpose of this study was to determine the effects of 4 weeks of resisted sprint training with sled towing. Twenty‐two trained athletes experienced in the use of weighted sled (WS) participated in the study. They conducted the same 3‐week training to level their initial condition. After that they were distributed in two groups, unresisted (UR) and WS training. They carried out the same 4‐week, 2 days/week sprint‐specific training, only differing in that the experimental group performed sprints with a (WS) which caused a reduction of 7.5% of their maximum velocity. Pre‐ and posttest were conducted which included the measurement of sprint kinematics, muscular strength (including isoinertial, isokinetic, and jump measurements), and sprinting stiffness (leg and vertical). Results show different adaptations in the groups although no interaction effect was found. The WS group improved the velocity in the transition phase, while the UR group improved the velocity in the maximum velocity phase. No improvements in the height of the jump tests were found.Actividad Física y Deport

A determination of the average up-down, strange and charm quark masses from Nf=2+1+1N_f=2+1+1

We present a lattice QCD determination of the average up-down, strange and charm quark masses based on simulations performed by the European Twisted Mass Collaboration with $N_f = 2 + 1 + 1$ dynamical fermions. We simulated at three different values of the lattice spacing, the smallest being approximately $0.06fm$, and with pion masses as small as $210 \text{MeV}$. Our results are: $m_{ud}(2\text{GeV})=3.70(17)\text{MeV}$, $m_s(2\text{GeV})=99.2(3.9)\text{MeV}$, $m_c(m_c)=1.350(49)\text{GeV}$, $m_s/m_{ud}=26.64(30)$ and $m_c/m_s=11.65(12)$

Analysis of both the envelope sequence and the complete genome of a HIV-1 subtype f cluster of rapid expansion in Galicia: coreceptor use prediction and phylogeny

La epidemia por VIH-1 en España, al igual que en el resto de Europa occidental, está dominada por el subtipo B. Sin embargo, recientemente se ha descrito la rápida expansión de un cluster de subsubtipo F1 entre hombres que tienen relaciones sexuales con hombres en Galicia. Los objetivos de este trabajo son analizar la secuencia de la envoltura de los virus del mencionado cluster para predicción de utilización de correceptores y presencia de aminoácidos característicos, así como caracterizar secuencias de genomas completos, determinando las relaciones filogenéticas con virus de subtipo F de otros países. Los análisis filogenéticos permitieron determinar relaciones del cluster F con virus de Brasil, Suiza, Bélgica, Francia y Gran Bretaña. Por otra parte, se han encontrado posiciones características del cluster en la región V3, diferentes de otras cepas F1, así como en otras regiones de la envoltura. Aparte, se han identificado mutaciones características asociadas a tropismo X4. El cluster de VIH-1 de subtipo F recientemente expandido en Galicia procede de una variante ampliamente diseminada en Europa occidental. Los virus de dicho cluster presentan aminoácidos característicos en la envoltura, identificándose en algunos de ellos mutaciones asociadas a tropismo X4, de potencial relevancia biológicaThe HIV-1 epidemic in Spain, as in the rest of Western Europe, is dominated by subtype B. However, it has recently been reported that a subsubtype F1 cluster has rapidly expanded among men who have sex with men in Galicia. The objectives of this work are to analyze the virus envelope sequence of the aforementioned cluster to predict the use of coreceptors and to examine the presence of characteristic amino acids, as well as to characterize full-length genome sequences, determining the phylogenetic relations with subtype F viruses from other countries. The phylogenetic analyses allowed to determine the relation of the Galician F cluster with viruses from Brazil, Switzerland, Belgium, France and Great Britain. On the other hand, characteristic amino acid residues were found in the V3 loop of viruses of the cluster, differing from other F1 strains, as well as in other regions of the envelope. Additionally, characteristic mutations associated with X4 tropism were identified. The HIV-1 subtype F cluster recently expanded in Galicia derives from a variant widely disseminated in Western Europe. The viruses of the mentioned cluster show characteristic amino acids in the envelope, with mutations associated with X4 tropism having been identified in some of them, which are of potential biological relevance

A HEV-restricted sulfotransferase is expressed in rheumatoid arthritis synovium and is induced by lymphotoxin-α/β and TNF-α in cultured endothelial cells

BACKGROUND: The recruitment of lymphocytes to secondary lymphoid organs relies on interactions of circulating cells with high endothelial venules (HEV). HEV are exclusive to these organs under physiological conditions, but they can develop in chronically-inflamed tissues. The interaction of L-selectin on lymphocytes with sulfated glycoprotein ligands on HEV results in lymphocyte rolling, which represents the initial step in lymphocyte homing. HEV expression of GlcNAc6ST-2 (also known as HEC-GlcNAc6ST, GST-3, LSST or CHST4), an HEV-restricted sulfotransferase, is essential for the elaboration of L-selectin functional ligands as well as a critical epitope recognized by MECA-79 mAb. RESULTS: We examined the expression of GlcNAc6ST-2 in relationship to the MECA-79 epitope in rheumatoid arthritis (RA) synovial vessels. Expression of GlcNAc6ST-2 was specific to RA synovial tissues as compared to osteoarthritis synovial tissues and localized to endothelial cells of HEV-like vessels and small flat-walled vessels. Double MECA-79 and GlcNAc6ST-2 staining showed colocalization of the MECA-79 epitope and GlcNAc6ST-2. We further found that both TNF-α and lymphotoxin-αβ induced GlcNAc6ST-2 mRNA and protein in cultured human umbilical vein endothelial cells. CONCLUSION: These observations demonstrate that GlcNAc6ST-2 is induced in RA vessels and provide potential cytokine pathways for its induction. GlcNAc6ST-2 is a novel marker of activated vessels within RA ectopic lymphoid aggregates. This enzyme represents a potential therapeutic target for RA

Optimal control theory for unitary transformations

The dynamics of a quantum system driven by an external field is well described by a unitary transformation generated by a time dependent Hamiltonian. The inverse problem of finding the field that generates a specific unitary transformation is the subject of study. The unitary transformation which can represent an algorithm in a quantum computation is imposed on a subset of quantum states embedded in a larger Hilbert space. Optimal control theory (OCT) is used to solve the inversion problem irrespective of the initial input state. A unified formalism, based on the Krotov method is developed leading to a new scheme. The schemes are compared for the inversion of a two-qubit Fourier transform using as registers the vibrational levels of the $X^1\Sigma^+_g$ electronic state of Na$_2$. Raman-like transitions through the $A^1\Sigma^+_u$ electronic state induce the transitions. Light fields are found that are able to implement the Fourier transform within a picosecond time scale. Such fields can be obtained by pulse-shaping techniques of a femtosecond pulse. Out of the schemes studied the square modulus scheme converges fastest. A study of the implementation of the $Q$ qubit Fourier transform in the Na$_2$ molecule was carried out for up to 5 qubits. The classical computation effort required to obtain the algorithm with a given fidelity is estimated to scale exponentially with the number of levels. The observed moderate scaling of the pulse intensity with the number of qubits in the transformation is rationalized.Comment: 32 pages, 6 figure

Is Vietnam in need of supportive policies for promoting roots and tubers development? Insights from Quang Binh province

Despite their relative importance to the Vietnamese agri-food system, root and tuber crops are under-represented in terms of supportive policies at national level. The case of Quang Binh province shows the existence of potentially more conducive frameworks at provincial level, recognizing cassava as one the three provincial strategic crops and highlighting the roles of root and tuber crops in general in replacing other crops vulnerable to climate change

CXCL12 is displayed by rheumatoid endothelial cells through its basic amino-terminal motif on heparan sulfate proteoglycans

The chemokine CXCL12 (also known as stromal cell-derived factor, SDF-1) is constitutively expressed by stromal resident cells and is involved in the homeostatic and inflammatory traffic of leukocytes. Binding of CXCL12 to glycosaminoglycans on endothelial cells (ECs) is supposed to be relevant to the regulation of leukocyte diapedesis and neoangiogenesis during inflammatory responses. To improve our understanding of the relevance of this process to rheumatoid arthritis (RA), we have studied the mechanisms of presentation of exogenous CXCL12 by cultured RA ECs. RA synovial tissues had higher levels of CXCL12 on the endothelium than osteoarthritis (OA) tissues; in both, CXCL12 colocalized to heparan sulfate proteoglycans (HSPGs) and high endothelial venules. In cultured RA ECs, exogenous CXCL12α was able to bind in a CXCR4-independent manner to surface HSPGs. Desulfation of RA EC HSPGs by pretreatment with sodium chlorate, or by replacing in a synthetic CXCL12α the residues Lys24 and Lys27 by Ser (CXCL12α-K2427S), decreased or abrogated the ability of the chemokine to bind to RA ECs. Ex vivo, synovial ECs from patients with either OA or RA displayed a higher CXCL12-binding capacity than human umbilical vein ECs (HUVECs), and in HUVECs the binding of CXCL12 was increased on exposure to tumor necrosis factor-α or lymphotoxin-α(1)β(2). Our findings indicate that CXCL12 binds to HSPGs on ECs of RA synovium. The phenomenon relates to the interaction of HSPGs with a CXCL12 domain with net positive surface charge located in the first β strand, which encompasses a canonical BXBB HSPG-binding motif. Furthermore, we show that the attachment of CXCL12 to HSPGs is upregulated by inflammatory cytokines. Both the upregulation of a constitutive chemokine during chronic inflammation and the HSPG-dependent immobilization of CXCL12 in EC surfaces are potential sites for therapeutic intervention