93 research outputs found
Effects of competition level on the centre forward role of men’s water polo.
This study aimed to compare specific technical and tactical indicators of the team and centre forward role of Euro League, and Italian Serie A1, Serie A2, and Serie B men's water polo club competitions. A notational analysis was performed on 21 water polo matches to evaluate the occurrence of technical and tactical team and centre forward indicators, highlighting differences among championships according to chi-square analyses. Differences emerged for Counterattack (P < 0.001) and Power-Play (P < 0.001) possessions, Even (P < 0.001; Euro League: 3 ± 1, Serie A1: 3 ± 2, Serie A2: 3 ± 2, Serie B: 6 ± 4) and Power-Play (P = 0.001) goals, and exclusions and penalties (P = 0.008) of the team during Even possessions. Relatively to the role analyses, effects emerged for perimeter players playing events (P = 0.049), as well as for centre forwards' goals (P = 0.007) and exclusions and penalties (P < 0.001; Euro League: 8 ± 1, Serie A1: 6 ± 2, Serie A2: 6 ± 2, Serie B: 3 ± 2) occurring at the end of Even possessions. Therefore, in Euro League, and Italian Serie A1 and Serie A2, teams perform a high occurrence of Power-Play possessions following up an exclusion, especially achieved by the centre forward during Even possessions, while, in Italian Serie B, goals were mostly scored during Even possessions, with a relevant contribution from the centre forward rol
Sequential NMR assignments of labile protons in DNA using two-dimensional nuclear-Overhauser-enhancement spectroscopy with three jump-and-return pulse sequences
Two-dimensional nuclear Overhauser enhancement (NOESY) spectra of labile protons were recorded in H2O solutions of a protein and of a DNA duplex, using a modification of the standard NOESY experiment with all three 90 degree pulses replaced by jump-and-return sequences. For the protein as well as the DNA fragment the strategically important spectral regions could be recorded with good sensitivity and free of artifacts. Using this procedure, sequence-specific assignments were obtained for the imino protons, C2H of adenine, and C4NH2 of cytosine in a 23-base-pair DNA duplex which includes the 17-base-pair OR3 repressor binding site of bacteriophage lambda. Based on comparison with previously published results on the isolated OR3 binding site, these data were used for a study of chain termination effects on the chemical shifts of imino proton resonances of DNA duplexes
Improved FTIR retrieval strategy for HCFC-22 (CHClFâ‚‚), comparisons with in situ and satellite datasets with the support of models, and determination of its long-term trend above Jungfraujoch
Hydrochlorofluorocarbons (HCFCs) are the first, but temporary, substitution products for the strong ozone-depleting chlorofluorocarbons (CFCs). HCFC consumption and production are currently regulated under the Montreal Protocol on Substances that Deplete the Ozone Layer and their emissions have started to stabilize or even decrease. As HCFC-22 (CHClF2) is by far the most abundant HCFC in today\u27s atmosphere, it is crucial to continue to monitor the evolution of its atmospheric concentration. In this study, we describe an improved HCFC-22 retrieval strategy from ground-based high-resolution Fourier transform infrared (FTIR) solar spectra recorded at the high-altitude scientific station of Jungfraujoch, the Swiss Alps, 3580 m a.m.s.l. (above mean sea level). This new strategy distinguishes tropospheric and lower-stratospheric partial columns. Comparisons with independent datasets, such as the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), supported by models, such as the Belgian Assimilation System for Chemical ObErvation (BASCOE) and the Whole Atmosphere Community Climate Model (WACCM), demonstrate the validity of our tropospheric and lower-stratospheric long-term time series. A trend analysis on the datasets used here, now spanning 30 years, confirms the last decade\u27s decline in the HCFC-22 growth rate. This updated retrieval strategy can be adapted for other ozone-depleting substances (ODSs), such as CFC-12. Measuring or retrieving ODS atmospheric concentrations is essential for scrutinizing the fulfilment of the globally ratified Montreal Protocol
Sperm Chemotaxis: The First Authentication Events Between Conspecific Gametes Before Fertilization
Phenylthiourea Specifically Reduces Zebrafish Eye Size
Phenylthiourea (PTU) is commonly used for inhibiting melanization of zebrafish embryos. In this study, the standard treatment with 0.2 mM PTU was demonstrated to specifically reduce eye size in larval fish starting at three days post-fertilization. This effect is likely the result of a reduction in retinal and lens size of PTU-treated eyes and is not related to melanization inhibition. This is because the eye size of tyr, a genetic mutant of tyrosinase whose activity is inhibited in PTU treatment, was not reduced. As PTU contains a thiocarbamide group which is presented in many goitrogens, suppressing thyroid hormone production is a possible mechanism by which PTU treatment may reduce eye size. Despite the fact that thyroxine level was found to be reduced in PTU-treated larvae, thyroid hormone supplements did not rescue the eye size reduction. Instead, treating embryos with six goitrogens, including inhibitors of thyroid peroxidase (TPO) and sodium-iodide symporter (NIS), suggested an alternative possibility. Specifically, three TPO inhibitors, including those that do not possess thiocarbamide, specifically reduced eye size; whereas none of the NIS inhibitors could elicit this effect. These observations indicate that TPO inhibition rather than a general suppression of thyroid hormone synthesis is likely the underlying cause of PTU-induced eye size reduction. Furthermore, the tissue-specific effect of PTU treatment might be mediated by an eye-specific TPO expression. Compared with treatment with other tyrosinase inhibitors or bleaching to remove melanization, PTU treatment remains the most effective approach. Thus, one should use caution when interpreting results that are obtained from PTU-treated embryos
Pets as Sentinels of Human Exposure to Neurotoxic Metals
The idea that animals may be used as sentinels of environmental hazards
pending over humans and the associated public health implications is not a new one.
Nowadays pets are being used as bioindicators for the effects of environmental contaminants
in human populations. This is of paramount importance due to the large
increase in the worldwide distribution of synthetic chemicals, particularly in the
built environment. Companion animals share the habitat with humans being simultaneously
exposed to and suffering the same disease spectrum as their masters.
Moreover, their shorter latency periods (due to briefer lifespans) enable them to act
as early warning systems, allowing timely public health interventions. The rise on
ethical constraints on the use of animals and, consequently, on the sampling they
can be subjected to has led to the preferential use of noninvasive matrices, and in
this case we are looking into hair. This chapter focuses in three non-essential metals:
mercury, lead, and cadmium, due to their ubiquitous presence in the built environment
and their ability of affecting the mammal nervous system. There is a fairly
short amount of studies reporting the concentrations of these metals in pets’ hair,
particularly for cats. These studies are characterized, and the metal concentrations
corresponding to different parameters (e.g., age, sex, diet, rearing) are described in
order to provide the reader with a general vision on the use of this noninvasive
matrix on the studies conducted since the last two decades of the twentieth
century.publishe
An epithelial localization of acetylcholinesterase in the ascidian Ciona intestinalis embryos and larvae.
Acetylcholinesterase activity was found associated to neuromusculara structures in the head and tail, as expected. An unexpected localization was also found at the membrane of the epithelial cells, before and during shrinkage occurring at metamorphosis. A role is hypothesized in non-neuromuscular cell-to-cell communication
Electrothermal atomisation atomic-absorption spectro\uacphotometric determination of chromium(VI) in urine by solvent extraction separation with liquid anion exchangers
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