Abiotic persistence of atrazine and simazine in water

Hydrolysis and photolysis experiments have been undertaken to investigate the abiotic persistence of atrazine and simazine in a variety of waters. Hydrolysis only occurs to a significant extent at pH values at the lower limit of those found in the natural aquatic environment (pH 4.0 or less). Photolysis was initiated by a wide range of wavelengths in waters at pH 4.0, but only by more energetic wavelengths of less than 300 nm at higher pH values (pH 6 to 8). Based on these data, the aquatic half-life of atrazine and simazine in well-lit acidic upland waters will be typically six days. In lowland rivers with higher pH (7 to 8.5), these triazines are likely to exhibit half-lives of months rather than days. In groundwaters, atrazine and simazine will have half-lives in the order of years, due to the exceedingly slow rate of hydrolysis. © 1999 Society of Chemical Industry     

Source analysis of the Crandall Canyon, Utah, mine collapse

Analysis of seismograms from a magnitude 3.9 seismic event on 6 August 2007 in central Utah reveals an anomalous radiation pattern that is contrary to that expected for a tectonic earthquake and which is dominated by an implosive component. The results show that the seismic event is best modeled as a shallow underground collapse. Interestingly, large transverse surface waves require a smaller additional noncollapse source component that might represent either faulting in the rocks above the mine workings or deformation of the medium surrounding the mine. Seismic moment tensor results for nuclear explosions, explosion and other mining cavity collapses, and tectonic earthquakes are compared, and the separation of the different populations indicates that the seismic moment tensor may be used for source-type discrimination.     

Serum protein electrophoresis values for free-ranging and zoo-based koalas (Phascolarctos cinereus)

In a clinical setting, especially with species of special interest, it is important to use all clinical pathology testing options for general health monitoring and diagnosis. Protein electrophoresis (EPH) has previously been shown to be an important adjunct tool in veterinary medicine. Serum samples from 18 free-ranging and 12 zoo-based koalas (Phascolarctos cinereus) were subject to EPH analysis. Significant differences were found between the two groups for the following values: total protein, albumin, beta globulins, and albumin-globulin ratio (P < 0.05). By using the combined data, the minimum-maximum values for the EPH fractions were as follows: total protein 5.0-7.8 g/dl, albumin 2.8-4.7 g/dl, alpha-1 globulins 0.5-1.1 g/dl, alpha-2 globulins 0.3-0.7 g/dl, beta globulins 0.4-1.0 g/dl, gamma globulins 0.2-1.0 g/dl, and albumin-globulin ratio 1.0-2.1.     

Development of a minimum-anesthetic-concentration depression model to study the effects of various analgesics in goldfish (Carassius auratus)

Teleost fish demonstrate the neurophysiologic capacity to experience pain and analgesia. A common model for assessing analgesic effect is the reduction of minimum anesthetic concentration (MAC). The present study adapted the model of MAC depression to evaluate the analgesic effects of morphine, butorphanol, medetomidine, and ketoprofen in goldfish (Carassius auratus). MAC was determined by an up-down method of sequential population sampling, anesthetizing fish with tricaine methanesulfonate (MS-222) in concentration increments of 10 parts per million (ppm), and using intramuscular needle insertion as a supramaximal noxious stimulus. Baseline MAC was determined in triplicate at the beginning (MACi) and conclusion (MACe) of the experiment (approximately 60 days). For drug trials, MAC was redetermined 1 hr after administration of morphine (10, 20, 40 mg/kg i.m.), butorphanol (0.1, 0.2, 0.4 mg/kg i.m.), medetomidine (0.01, 0.015, 0.025 mg/kg i.m.), ketoprofen (0.5, 1.0, 2.0 mg/kg i.m.), or saline control. Each drug/dose was tested in random order with a > 6-day washout period. MACi and MACf were 163 and 182 ppm, respectively, and were significantly different from each other (P = 0.02). All doses of morphine and ketoprofen decreased MAC below MACi. The highest dose of medetomidine decreased MAC below MACi. The lowest dose of butorphanol decreased MAC below MACi, but higher doses increased MAC above MACf. The authors conclude that MAC determination in fish using MS-222 was feasible and reproducible in the short term. The fact that MAC increased over time and/or exposure may limit the usefulness of MS-222 in MAC depression studies. Morphine and ketoprofen decrease anesthetic needs in goldfish and may provide analgesia.     

New challenges for vaccination to prevent chlamydial abortion in sheep

Ovine enzootic abortion (OEA) is caused by the obligate intracellular Gram-negative bacterium Chlamydia abortus. OEA remains a common cause of infectious abortion in many sheep-rearing countries despite the existence of commercially available vaccines that protect against the disease. There are a number of confounding factors that influence the uptake and use of these vaccines, which includes an inability to discriminate between infected and vaccinated animals (DIVA) using conventional serological diagnostic techniques. This suggests that the immunity elicited by current vaccines is similar to that observed in convalescent, immune sheep that have experienced OEA. The existence of these vaccines provides an opportunity to understand how protection against OEA is elicited and also to understand why vaccines can occasionally appear to fail, as has been reported recently for OEA. Interferon-gamma (IFN-γ), the cytokine that classically defines Th1-type adaptive immunity, is a strong correlate of protection against OEA in sheep and has been shown to inhibit the growth of C. abortus in vitro. Humoral immunity to C. abortus is observed in both vaccinated and naturally infected sheep, but antibody responses tend to be used more as diagnostic markers than targets for strategic vaccine design. A future successful DIVA vaccine against OEA should aim to elicit the immunological correlate of protection (IFN-γ) concomitantly with an antibody profile that is distinct from that of the natural infection. Such an approach requires careful selection of protective components of C. abortus combined with an effective delivery system that elicits IFN-γ-producing CD4+ve memory T cells.     

Abiogenic hydrocarbon production at lost city hydrothermal field

Low-molecular-weight hydrocarbons in natural hydrothermal fluids have been attributed to abiogenic production by Fischer-Tropsch type (FTT) reactions, although clear evidence for such a process has been elusive. Here, we present concentration, and stable and radiocarbon isotope, data from hydrocarbons dissolved in hydrogen-rich fluids venting at the ultramafic-hosted Lost City Hydrothermal Field. A distinct "inverse" trend in the stable carbon and hydrogen isotopic composition of C1 to C4 hydrocarbons is compatible with FTT genesis. Radiocarbon evidence rules out seawater bicarbonate as the carbon source for FTT reactions, suggesting that a mantle-derived inorganic carbon source is leached from the host rocks. Our findings illustrate that the abiotic synthesis of hydrocarbons in nature may occur in the presence of ultramafic rocks, water, and moderate amounts of heat.