Ecotoxicological characterisation of sedimentation in the Kis-Balaton Water Protection System

The main function of the Kis-Balaton Water Protection System is to retain nutrients and total suspended solids, thus protecting the water quality of Lake Balaton. In this paper, the toxic nature of the sediment in the 2nd reservoir of the KBWPS has been characterised, using a battery of tests: Vibrio fischeri acute bioassay on whole sediment samples, and V. fischeri bioassay on pore water and elutriate samples. The latest version of the V. fischeri bioluminescence inhibition was applied, the Flash assay which uses a kinetic mode and is able to detect the toxicity of solid, turbid/coloured samples. Whole sediment toxicity showed a clear spatial distribution of toxicity, in parallel with elutriate toxicity. However, no pore water toxicity was detected, leading to the conclusion that contaminants are not water soluble.

Spectroscopic and Molecular Weight Studies of Polytoluidines

Poly(o-toluidine) and poly(m-toluidine) in base form have been characterized by infrared and lH NMR spectroscopy. Assignments of the proton NMR signals have been facilitated by the use of model compounds. The distinction between benzenoid and quinoid methyl resonances in the NMR permits a semi-quantitative estimation of the oxidation states of the polytoluidines. Infrared studies are consistent with a polyaniline-type backbone having pendant methyl groups. Field desorption mass spectrometry (FD-MS) was employed for estimation of the molecular weight of poly(o-toluidine). Gel-permeation chromatography of the same sample showed a bimodal elution pattern, suggesting that the FD-MS technique detects only the lower molecular weight fraction of the polymer. Despite this inherent limitation, FD-MS yields the interesting information that the polymer contains chains of both odd and even numbers of repeat units, necessitating the coexistence of different oxidation states in the base form of the polymer.

Macrocephaly in bull spermatozoa is associated with nuclear vacuoles, diploidy and alteration of chromatin condensation

Spermatozoa from 2 dairy AI (artificial insemination) bulls (A and B), identified by their abnormal spermiogram with cells depicting frequent macrocephaly, double tails and nuclear vacuoles, were case-investigated and compared to normal spermatozoa from a control AI sire (C). Head sizes were measured and morphological abnormalities scored using brightfield and differential interference contrast microscopy. The degree of sperm maturation and of resistance to acid-induced DNA denaturation in situ were determined after uploading of acridine orange using flow cytometry of 5,000 cells/sample. Nuclear fragmentation, i.e. the ratio of red to total (red + green) fluorescence, reached 7.1% and 31% in bulls A and B, compared to 2% in bull C. The proportion of immature spermatozoa, i.e. those with incomplete histone-protamine exchange and depicting higher green fluorescence compared to the main population of the control bull, reached 9.54% in A and 7.75% in B, compared to only 0.47% in the control. In the second part of this study the previously unknown chromosomal constitution of large-headed spermatozoa of bull A was investigated by fluorescence in situ hybridization using an X-Y painting probe set. The 7.5% XY-bearing cells and the presence of diploid spermatozoa detected by flow cytometry indicate a meiotic arrest in the first division in bull A, becoming the first proven case of association of macrocephaly and M1 diploidy. The diverse approaches used for the investigation of spermatozoal DNA provide insights into the etiology of macrocephaly.

Diploid spermatozoa caused by failure of the second meiotic division in a bull

An artificial insemination bull (Bos taurus) exhibiting 23% macrocephalic spermatozoa in the ejaculate was investigated. Spermatozoa with a projected head area of > or = 52 microm(2) were considered macrocephalic. Diploidy was assumed from the measurement of sperm head area and proved by flow cytometry, which was used to sort the sperm into haploid and diploid fractions. Fluorescence in situ hybridization was used to detect the sex chromosomes with an X-Y probe set. Diploid spermatozoa most likely originate from a defective second meiotic division (M2 diploids), as only 0.7% XY-bearing spermatozoa (M1 diploids) were detected in the spermatozoa of the flow cytometric diploid sort. The painting probes generated a single X or Y spot for both unsorted semen and diploid sorted spermatozoa. This indicates a close proximity of the nonpartitioned sister chromatids in the spermatozoa. The BC1.2 probe, which labels BTAYp13-12, was used to clarify the presence of the two chromatids in the singular signal of the simultaneously hybridized Y-painting probe. In scoring more than 1000 randomly sampled spermatozoa hybridized with the BC1.2 probe, 32% showed the YY diploid signal and 18% the Y signal. The sperm diploidy in this bull was caused by an incomplete partitioning of sister chromatids during the second meiotic division (M2) associated with a failure in nuclear cleavage.

Functional renormalization group approach to the sine-Gordon model

The renormalization group flow is presented for the two-dimensional sine-Gordon model within the framework of the functional renormalization group method by including the wave-function renormalization constant. The Kosterlitz-Thouless-Berezinski type phase structure is recovered as the interpolating scaling law between two competing IR attractive area of the global renormalization group flow.

Searching for DNA markers for milk production and composition on chromosome 6 in sheep

Several milk protein polymorphisms are potential tools for selection in dairy ruminants. However, research results for dairy sheep are not as conclusive as those for goats or cattle and are often controversial. The main objective of this study was to find and later use molecular genetic markers in selection to improve milk production and milk composition in Awassi ewes. Chromosome 6 was chosen because several studies have reported the presence of significant quantitative trait loci (QTL) affecting milk production traits on ovine and bovine chromosome 6. Altogether, genotypes for 13 microsatellite loci were determined for 258 ewes, which were purebred Awassi or Awassi-Merino crosses. Phenotypic data were lactation yield of milk, milk fat, protein and lactose (kg), average milk protein and fat percentage and average somatic cell count. Five out of the 13 microsatellites showed significant association with at least one of the examined traits.

Modulation of cardiac contractility through endothelin-1 release and myocardial mast cell degranulation

The aim of this study was to outline the consequences of a hypertonic saline-dextran-40 (HSD) infusion-induced peripheral flow stimulus on the ventricular function in closed-chest, pentobarbital-anesthetized dogs. We hypothesized that HSD-induced elevation in endothelin-1 (ET-1) and nitric oxide (NO) release can have a role in myocardial contractile responses; and that cardiac mast cells (MC) degranulation may be involved in this process. The consequences of disodium cromoglycate (a MC stabilizer) or ETR-p1/fl peptide (an endothelin-A receptor antagonist) treatment were evaluated. A 4 ml/kg iv HSD40 infusion significantly increased cardiac index and myocardial contractility, and resulted in a decreased peripheral resistance. The postinfusion period was characterized by significant plasma NO and ET-1 elevations, these hemodynamic and biochemical changes being accompanied by a decreased myocardial ET-1 content, NO synthase activity and enhanced myocardial MC degranulation. Disodium cromoglycate treatment inhibited the HSD40-induced elevations in myocardial contractility and MC degranulation, and similar hemodynamic changes were noted after treatment with ETR-p1/fl peptide, together with a normalized myocardial myocardial ET-1 content, NO synthesis and a significant reduction in MC degranulation. These results indicate that peripheral NO and ET-1 release modulates the cardiac contractility through myocardial ET-A receptor activation and MC degranulation.

Critical ruptures in a bundle of slowly relaxing fibers

We study the damage enhanced creep rupture of disordered materials by means of a fiber bundle model. Broken fibers undergo a slow stress relaxation modeled by a Maxwell element whose stress exponent m can vary in a broad range. Under global load sharing we show that due to the strength disorder of fibers, the lifetime t(f) of the bundle has sample-to-sample fluctuations characterized by a log-normal distribution independent of the type of disorder. We determine the Monkman-Grant relation of the model and establish a relation between the rupture life t(f) and the characteristic time t(m) of the intermediate creep regime of the bundle where the minimum strain rate is reached, making possible reliable estimates of t(f) from short term measurements. Approaching macroscopic failure, the deformation rate has a finite time power law singularity whose exponent is a decreasing function of m. On the microlevel the distribution of waiting times is found to have a power law behavior with m-dependent exponents different below and above the critical load of the bundle. Approaching the critical load from above, the cutoff value of the distributions has a power law divergence whose exponent coincides with the stress exponent of Maxwell elements.

New mass value for 7Li

A high-accuracy mass measurement of 7Li was performed with the SMILETRAP Penning-trap mass spectrometer via a cyclotron frequency comparison of 7Li3+ and H2+. A new atomic-mass value of 7Li has been determined to be 7.016 003 425 6(45) u with a relative uncertainty of 0.63 ppb. It has uncovered a discrepancy as large as 14sigma (1.1 microu) deviation relative to the literature value given in the Atomic-Mass Evaluation AME 2003. The importance of the improved and revised 7Li mass value, for calibration purposes in nuclear-charge radii and atomic-mass measurements of the neutron halos 9Li and 11Li, is discussed.

Optimal timing for intravenous administration set replacement

BACKGROUND

Administration of intravenous therapy is a common occurrence within the hospital setting. Routine replacement of administration sets has been advocated to reduce intravenous infusion contamination. If decreasing the frequency of changing intravenous administration sets does not increase infection rates, a change in practice could result in considerable cost savings.

OBJECTIVES

The objective of this review was to identify the optimal interval for the routine replacement of intravenous administration sets when infusate or parenteral nutrition (lipid and non-lipid) solutions are administered to people in hospital via central or peripheral venous catheters.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, EMBASE: all from inception to February 2004; reference lists of identified trials, and bibliographies of published reviews. We also contacted researchers in the field. We did not have a language restriction.

SELECTION CRITERIA

We included all randomized or quasi-randomized controlled trials addressing the frequency of replacing intravenous administration sets when parenteral nutrition (lipid and non-lipid containing solutions) or infusions (excluding blood) were administered to people in hospital via a central or peripheral catheter.

DATA COLLECTION AND ANALYSIS

Two authors assessed all potentially relevant studies. We resolved disagreements between the two authors by discussion with a third author. We collected data for the outcomes; infusate contamination; infusate-related bloodstream infection; catheter contamination; catheter-related bloodstream infection; all-cause bloodstream infection and all-cause mortality.

MAIN RESULTS

We identified 23 references for review. We excluded eight of these studies; five because they did not fit the inclusion criteria and three because of inadequate data. We extracted data from the remaining 15 references (13 studies) with 4783 participants. We conclude that there is no evidence that changing intravenous administration sets more often than every 96 hours reduces the incidence of bloodstream infection. We do not know whether changing administration sets less often than every 96 hours affects the incidence of infection. In addition, we found that there were no differences between participants with central versus peripheral catheters; nor between participants who did and did not receive parenteral nutrition, or between children and adults.

AUTHORS' CONCLUSIONS

It appears that administration sets that do not contain lipids, blood or blood products may be left in place for intervals of up to 96 hours without increasing the incidence of infection. There was no evidence to suggest that administration sets which contain lipids should not be changed every 24 hours as currently recommended.

Unambiguous identification of three beta-decaying isomers in 70Cu

Using resonant laser ionization, beta-decay studies, and for the first time mass measurements, three beta-decaying states have been unambiguously identified in 70Cu. A mass excess of -62 976.1(1.6) keV and a half-life of 44.5(2) s for the (6-) ground state have been determined. The level energies of the (3-) isomer at 101.1(3) keV with T(1/2)=33(2) s and the 1+ isomer at 242.4(3) keV with T(1/2)=6.6(2) s are confirmed by high-precision mass measurements. The low-lying levels of 70Cu populated in the decay of 70Ni and in transfer reactions compare well with large-scale shell-model calculations, and the wave functions appear to be dominated by one proton-one neutron configurations outside the closed Z=28 shell and N=40 subshell. This does not apply to the 1+ state at 1980 keV which exhibits a particular feeding and deexcitation pattern not reproduced by the shell-model calculations.

Head area measurements of dead, live, X- and Y-bearing bovine spermatozoa

The head area of bull spermatozoa was measured after viability and acrosome staining using trypan blue and Giemsa stains, followed by X- and Y-chromosome-specific fluorescence in situ hybridisation (FISH). The former staining made possible the categorisation of cells according to morphology and membrane integrity, whereas the latter allowed distinction of spermatozoa bearing X- and Y-chromosomes. Individual spermatozoa could be followed during the consecutive steps of staining, measurement and FISH. Using a high-resolution digital imaging system and measurement software, the head area of more than 3000 cells of five bulls was determined precisely. In all bulls, morphologically normal, viable cells with intact acrosomes were significantly smaller than dead cells with damaged acrosomes. No significant difference in the head area between X- and Y-chromosome-bearing viable, acrosome-intact spermatozoa was found in individual bulls. However, significant between-bull differences were detected in all cell categories.