436 research outputs found
KINEMATIC ANALYSIS OF LOWER LIMB IN FUTSAL BALL KICKING
The diameter of the futsal ball (200 mm) is smaller than that of the soccer ball by 20 mm, and the futsal ball also has lower resilience than the soccer ball. Because of these differences in the balls, it is thought that the kicking motions of futsal players are distinct from those of soccer players. No study has yet been conducted on the motion involved in kicking a futsal ball. The aim of this study was to clarify the difference between the motion involved in kicking the futsal ball with that involved in kicking the soccer ball
Magnetic excitations in an ionic spin-chain system with a non-magnetic ferroelectric instability
Cross-correlation between magnetism and dielectric is expected to offer novel
emergent phenomena. Here, magnetic excitations in the organic donor-acceptor
spin-chain system, TTF-BA, with a ferroelectric ground state is investigated by
H-NMR spectroscopy. A nonmagnetic transition with a ferroelectric order is
marked by sharp drops in NMR shift and nuclear spin relaxation rate
at 53 K. Remarkably, the analyses of the NMR shift and dictate that
the paramagnetic spin susceptibility in TTF-BA is substantially suppressed from
that expected for the 1D Heisenberg spins. We propose that the spin-lattice
coupling and the ferroelectric instability cooperate to promote precursory
polar singlet formation in the ionic spin system with a nonmagnetic
ferroelectric instability.Comment: 6 pages, 4 figure
Modelling state-dependent interference in common cranes
1. Interference is a key component of food competition, but is difficult to measure in
natural animal populations. Using data from a long-term study, we show that interference
between common cranes Grus grus L., feeding on patches of cereal seeds, reduces intake
rates at high competitor densities, and that the strength of interference is unrelated to
food abundance.
2. An alternative to measuring interference directly is to predict its strength using
behaviour-based models. We test an interference model, originally developed for
shorebirds feeding on invertebrate prey, for cranes. We compare the predictions of a
rate-maximizing model, in which animals steal food if this increases intake rate, and
a state-dependent model, in which they only rate-maximize if their intake rate is below
a target value, otherwise they minimize injury risk by not stealing food. State-dependent aggression occurs in cranes.
3. The state-dependent model predicts more accurately the relative aggression rates of
cranes of different dominance. However, both models predict accurately the observed strength of interference, that the strength of interference is unrelated to food abundance, at least within the observed range of crane and seed densities, and that cranes of a higher dominance have a higher intake rate than those of lower dominance.
4. This paper shows how state-dependent behaviour can be incorporated into an
interference model, and that the model can produce accurate predictions for a system
quite different to that for which it was developed.RAS was funded by the Natural Environment Research Council.
LMB was partially funded by Ministerio de Ciencia y TecnologÃa (MCyT) and research grant PB97-1252 of MCyT. Field work was funded by DGICYT project PB87-0389 of the MCyT.Peer reviewe
Realising a species-selective double well with multiple-radiofrequency-dressed potentials
Techniques to manipulate the individual constituents of an ultracold mixture
are key to investigating impurity physics. In this work, we confine a mixture
of the hyperfine ground states of Rb-87 in a double-well potential. The
potential is produced by dressing the atoms with multiple radiofrequencies. The
amplitude and phase of each frequency component of the dressing field are
individually controlled to independently manipulate each species. Furthermore,
we verify that our mixture of hyperfine states is collisionally stable, with no
observable inelastic loss.Comment: 11 pages, 4 figure
Cyclooxygenase-2 overexpression correlates with tumour recurrence, especially haematogenous metastasis, of colorectal cancer
Epidemiological studies have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs), known to inhibit cyclooxygenase (COX), reduce the risk of colorectal cancer. COX is a key enzyme in prostaglandin biosynthesis, and two isoforms of COX, COX-1 and COX-2, have been identified. Recently COX-2 has been reported to frequently overexpress in colorectal neoplasms and to play a role in colorectal tumorigenesis and tumour progression. In this study, using immunohistochemistry, we examined COX-2 expression in advanced human colorectal cancer and its correlation with clinicopathological features. COX-2 expression was observed mainly in the cytoplasm of cancer cells in all the specimens examined, but some stromal cells and endothelial cells were also stained. According to the grade of COX-2 expression of the cancer cells, patients were divided into high- and low-COX-2 expression groups. High-COX-2 expression significantly correlated with tumour recurrence, especially haematogenous metastasis. These results suggest that a selective COX-2 inhibitor can be a novel class of therapeutic agents not only for tumorigenesis but also for haematogenous metastasis of cololectal cancer. To our knowledge, this is the first report on the correlation between COX-2 overexpression and recurrence of colorectal cancer. © 2000 Cancer Research Campaig
Streamlined vessels for speedboats: Macro modifications of shark skin design applications
Functional properties of shark denticles have caught the attention of engineers and scientist today due to the hydrodynamic effects of its skin surface roughness. The skin of a fast swimming shark reveals riblet structures that help to reduce skin friction drag, shear stresses, making its movement to be more efficient and faster. Inspired by the structure of the shark skin denticles, our team has conducted a study on alternative on improving the hydrodynamic design of marine vessels by applying the simplified version of shark skin skin denticles on the surface hull of the vessels. Models used for this study are constructed and computational fluid dynamic (CFD) simulations are then carried out to predict the effectiveness of the hydrodynamic effects of the biomimetic shark skins on those models. Interestingly, the numerical calculated results obtained shows that the presence of biomimetic shark skin implemented on the vessels give improvements in the maximum speed as well as reducing the drag force experience by the vessels. The pattern of the wave generated post cruising area behind the vessels can also be observed to reduce the wakes and eddies. Theoretically, reduction of drag force provides a more efficient vessel with a better cruising speed. To further improve on this study, the authors are now actively arranging an experimental procedure in order to verify the numerical results obtained by CFD. The experimental test will be carried out using an 8 metre flow channel provided by University Malaysia Sarawak, Malaysia. © 2018 Author(s)
Loss of the mammal-specific tectorial membrane component CEA cell adhesion molecule 16 (CEACAM16) leads to hearing impairment at low and high frequencies
The vertebrate-restricted carcinoembryonic antigen gene family evolves extremely rapidly. Among their widely expressed members, the mammal-specific, secreted CEACAM16 is exceptionally well conserved and specifically expressed in the inner ear. To elucidate a potential auditory function we inactivated murine Ceacam16 by homologous recombination. In young Ceacam16-/- mice the hearing threshold for frequencies below 10 kHz and above 22 kHz was raised. This hearing impairment progressed with age. A similar phenotype is observed in hearing-impaired members of Family 1070 with non-syndromic autosomal dominant hearing loss (DFNA4) who carry a missense mutation in CEACAM16. CEACAM16 was found in interdental and Deiters cells and was deposited in the tectorial membrane of the cochlea between postnatal day 12 and 15, when hearing starts in mice. In cochlear sections of Ceacam16-/- mice tectorial membranes were significantly more often stretched out as compared to wild-type mice where they were mostly contracted and detached from the outer hair cells. Homotypic cell sorting observed after ectopic cell surface expression of the carboxy-terminal immunoglobulin variable-like N2 domain of CEACAM16 indicated that CEACAM16 can interact in trans. Furthermore, Western blot analyses of membrane-bound CEACAM16 under reducing and non-reducing conditions demonstrated oligomerization via unpaired cysteines. Taken together, CEACAM16 probably can form higher order structures with other tectorial membrane proteins such as α-tectorin and β-tectorin and influences the physical properties of the tectorial membrane. Evolution of CEACAM16 might have been an important step for the specialization of the mammalian cochlea allowing hearing over an extended frequency range
LINE-1 hypomethylation status of circulating cell-free DNA in plasma as a biomarker for colorectal cancer.
Colorectal cancer (CRC) is a serious public health problem and non-invasive biomarkers improving diagnosis or therapy are strongly required. Circulating cell-free DNA (cfDNA) has been a promising target for this purpose. In this study, we evaluated the potential of long interspersed nuclear element-1 (LINE-1) hypomethylation as a blood biomarker for CRC. LINE-1 hypomethylation level in plasma cfDNA in 114 CRC patients was retrospectively examined by absolute quantitative analysis of methylated alleles real-time PCR, and was expressed using LINE-1 hypomethylation index (LHI) [unmethylated copy number/ (methylated copy number + unmethylated copy number)]. Greater LHI values indicated enhanced hypomethylation. In our clinicopathological analysis, CRC patients with large tumors (≥6.0 cm), advanced N stage (≥2), and distant metastasis (M1) had statistically significantly higher cfDNA LHI than other CRC patients, suggesting cfDNA LHI as a disease progression biomarker for CRC. Furthermore, early stage I/II (n = 57) as well as advanced stage III/IV (n =57) CRC patients had significantly higher cfDNA LHI than healthy donors (n=53) [stage I/II: median 0.369 (95% confidence interval, 0.360-0.380) vs. 0.332 (0.325-0.339), P \u3c 0.0001; stage III/IV: 0.372 (0.365-0.388) vs. 0.332 (0.325-0.339), P \u3c 0.0001]. The receiver operating characteristic analysis showed that cfDNA LHI had the detection capacity of CRC with area under the curve(AUC) of 0.79 and 0.83 in stage I/II and stage III/IV CRC patients, respectively. The present study demonstrated for the first time the potential of plasma cfDNA LHI as a novel biomarker for CRC, particularly for early stage detection
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