Efficacy of famotidine for the prevention of exercise-induced gastritis in racing Alaskan sled dogs

BACKGROUND: Omeprazole reduces the severity of exercise-induced gastritis but not the prevalence of gastric lesions in sled dogs. The frequent feeding of sled dogs during competition likely results in decreased absorption of omeprazole and, thereby, decreased efficacy. HYPOTHESIS: Famotidine, a histamine-2 blocker with good bioavailability in the presence of food, would reduce the incidence and severity of exercise-induced gastric disease in sled dogs. ANIMALS: Sixteen fit Alaskan sled dogs (4 female, 12 male, all intact, age 2-6 years). METHODS: Dogs were randomly assigned to treatment (22 mg famotidine PO q24h) or control groups (n = 8 per group). Famotidine was administered with a meal to the treatment group once daily for 7 days before a challenge and once during exercise. Control dogs were fed an identical diet as the principal group. The 16 dog team completed a 100-mile exercise challenge in 18 hours. A gastroscopy was performed 24 hours after the challenge. The appearance of the mucosa was scored by an individual by using a scoring system. RESULTS: Treatment with famotidine significantly reduced the severity score compared with control (P = .0004). No adverse effects of treatment were reported. CONCLUSIONS AND CLINICAL RELEVANCE: Famotidine is effective in reducing the severity of exercise-induced gastric disease in racing Alaskan sled dogs, with minimal to no adverse effects, and may be recommended for prophylactic use in short distance races.     

Direct measurement of the reaction front in chemically amplified photoresists

The continuing drive by the semiconductor industry to fabricate smaller structures using photolithography will soon require dimensional control at length scales comparable to the size of the polymeric molecules in the materials used to pattern them. The current technology, chemically amplified photoresists, uses a complex reaction-diffusion process to delineate patterned areas with high spatial resolution. However, nanometer-level control of this critical process is limited by the lack of direct measurements of the reaction front. We demonstrate the use of x-ray and neutron reflectometry as a general method to measure the spatial evolution of the reaction-diffusion process with nanometer resolution. Measuring compositional profiles, provided by deuterium-labeled reactant groups for neutron scattering contrast, we show that the reaction front within the material is broad rather than sharply defined and the compositional profile is altered during development. Measuring the density profile, we directly correlate the developed film structure with that of the reaction front.     

Radiative absorption enhancements due to the mixing state of atmospheric black carbon

Atmospheric black carbon (BC) warms Earth's climate, and its reduction has been targeted for near-term climate change mitigation. Models that include forcing by BC assume internal mixing with non-BC aerosol components that enhance BC absorption, often by a factor of ~2; such model estimates have yet to be clearly validated through atmospheric observations. Here, direct in situ measurements of BC absorption enhancements (E(abs)) and mixing state are reported for two California regions. The observed E(abs) is small-6% on average at 532 nm-and increases weakly with photochemical aging. The E(abs) is less than predicted from observationally constrained theoretical calculations, suggesting that many climate models may overestimate warming by BC. These ambient observations stand in contrast to laboratory measurements that show substantial E(abs) for BC are possible.     

Eubacterial communities in different soil macroaggregate environments and cropping systems

Different positions within soil macroaggregates, and macroaggregates of different sizes, have different chemical and physical properties which could affect microbial growth and interactions among taxa. The hypothesis that these soil aggregate fractions contain different eubacterial communities was tested using terminal restriction fragment length polymorphism (T-RFLP) of the 16S ribosomal gene. Communities were characterized from two field experiments, located at the Kellogg Biological Station (KBS), MI, USA and the Ohio Agricultural Research and Development Center (OARDC), Wooster, OH, USA. Three soil management regimes at each site were sampled and management was found to significantly affect T-RFLP profiles. The soil aggregate erosion (SAE) method was used to isolate aggregate regions (external and internal regions). Differences between eubacterial T-RFLP profiles of aggregate exteriors and interiors were marginally significant at KBS (accounting for 12.5% of total profile variance), and not significant at OARDC. There were no significant differences among macroaggregate size classes at either site. These results are in general agreement with previous studies using molecular methods to examine microbial communities among different soil macroaggregate size fractions, although further study of communities within different aggregate regions is warranted. Analysis of individual macroaggregates revealed large inter-aggregate variability in community structure. Hence the tertiary components of soil structure, e.g. arrangement of aggregates in relation to shoot residue, roots, macropores, etc., may be more important than aggregate size or intra-aggregate regions in the determination of the types of microbial communities present in aggregates. Direct microscopic counts were also used to examine the bacterial population size in aggregate regions at KBS. The proportion of bacterial cells with biovolumes >0.18 μm³ was higher in aggregate interiors than in exteriors, indicating potentially higher activity in that environment. This proportion was significantly related to percent C of the samples, while total bacterial cell counts were not.     

Evaluating the risk of tick‐borne relapsing fever among occupational cavers—Austin,TX, 2017

Tick‐borne relapsing fever (TBRF) is a potentially serious spirochetal infection caused by certain species of Borrelia and acquired through the bite of Ornithodoros ticks. In 2017, Austin Public Health, Austin, TX, identified five cases of febrile illness among employees who worked in caves. A cross‐sectional serosurvey and interview were conducted for 44 employees at eight organizations that conduct cave‐related work. Antibodies against TBRF‐causing Borrelia were detected in the serum of five participants, four of whom reported recent illness. Seropositive employees entered significantly more caves (Median 25 [SD: 15] versus Median 4 [SD: 16], p = 0.04) than seronegative employees. Six caves were entered more frequently by seropositive employees posing a potentially high risk. Several of these caves were in public use areas and were opened for tours. Education of area healthcare providers about TBRF and prevention recommendations for cavers and the public are advised.     

日光温室保温被卷放位置对温度环境的影响

温室保温被卷放位置影响着室内的太阳能得热及通过前屋面的散热,从而影响着温室温度。该研究以室外气象因子为模拟输入条件,分别模拟晴天、阴天不同保温被卷放位置对12 m跨度日光温室温度环境的影响。保温被卷放位置分别为保温被卷至前屋面一半与至顶2种方案。模拟结果显示：白天保温被卷至前屋面一半的室内空气温度高于保温被卷至屋顶的温度,而夜间2种方案室内空气温度差异不明显;晴天保温被卷至屋顶与卷至前屋面一半相比,可明显提高夜间墙体表面温度,但对后坡的夜间表面温度影响较小。该研究结果对温室生产中晴天、阴天保温被卷的合理放     

Physiological and biochemical characterization of quinclorac resistance in a false cleavers (Galium spurium L.) biotype

The physiological and biochemical basis for quinclorac resistance in a false cleavers (Galium spurium L.) biotype was investigated. There was no difference between herbicide resistant (R) and susceptible (S) false cleavers biotypes in response to 2,4-D, clopyralid, glyphosate, glufosinate-ammonium, or bentazon. On the basis of GR(50) (growth reduction of 50%) or LD(50) (lethal dose to 50% of tested plants) values, the R biotype was highly resistant to the acetolactate synthase (ALS) inhibitor, thifensulfuron-methyl (GR(50) resistance ratio R/S = 57), and quinolinecarboxylic acids (quinclorac R/S = 46), resistant to MCPA (R/S = 12), and moderately resistant to the auxinic herbicides picloram (R/S = 3), dicamba (R/S = 3), fluroxypyr (R/S = 3), and triclopyr (R/S = 2). The mechanism of quinclorac resistance was not due to differences in [(14)C]quinclorac absorption, translocation, root exudation, or metabolism. Seventy-two hours after root application of quinclorac, ethylene increased ca. 3-fold in S but not R plants when compared to controls, while ABA increased ca. 14-fold in S as opposed to ca. 3-fold in R plants suggesting an alteration in the auxin signal transduction pathway, or altered target site causes resistance in false cleavers. The R false cleavers biotype may be an excellent model system to further examine the auxin signal transduction pathway and the mechanism of quinclorac and auxinic herbicide action.