Experimental establishment of persistent infection in swine with a zoonotic strain of Salmonella newport

An experiment was conducted to determine whether a persistent Salmonella newport infection could be established in swine, to determine duration of shedding and distribution of the organism in internal organs, and to determine whether changes occurred in antimicrobial susceptibility or plasmid profile of the organism during the course of long-term infection. Naturally farrowed Salmonella-free pigs (n = 22) were orally exposed to a multiply antimicrobial-resistant zoonotic strain of S newport when they were 7 weeks old. Tonsillar and rectal swab specimens were examined bacteriologically for S newport during the first week after exposure, then weekly for 7 weeks. Fecal samples were likewise examined weekly or every 2 weeks for 28 weeks after exposure. Necropsies of 2 or 3 randomly selected pigs were conducted at 2, 4, 8, 12, 16, 20, 24, and 28 weeks after exposure. A total of 45 specimens/pig representing the following internal organs or tissues were examined bacteriologically for S newport: liver, spleen, kidney, gallbladder, heart, heart blood, lung, stomach, and tonsils; segments of the intestinal tract with corresponding lymph nodes; and lymph nodes from lymphocenters of the head and neck, thoracic cavity, thoracic limbs, abdominal viscera, and abdominal wall. Exposure to S newport induced a mild and transient clinical response. The organism was recovered from 97% of tonsillar swab specimens and 89% of rectal swab specimens collected during 7 weeks after exposure and from 98% of fecal samples collected during 28 weeks after exposure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Feedbacks between deforestation,climate, and hydrology in the Southwestern Amazon: implications for the provision of ecosystem services

Forests, through the regulation of regional water balances, provide a number of ecosystem services, including water for agriculture, hydroelectric power generation, navigation, industry, fisheries, and human consumption. Large-scale deforestation triggers complex non-linear interactions between the atmosphere and biosphere, which may impair such important ecosystem services. This is the case for the Southwestern Amazon, where three important river basins (Juruá, Purus, and Madeira) are undergoing significant land-use changes. Here, we investigate the potential impacts of deforestation throughout the Amazon on the seasonal and annual water balances of these river basins using coupled climatic and hydrologic models under several deforestation scenarios. Simulations without climate response to deforestation show an increase in river discharge proportional to the area deforested in each basin, whereas those with climate response produce progressive reductions in mean annual precipitation over all three basins. In this case, deforestation decreases the mean annual discharge of the Juruá and Purus rivers, but increases that of the Madeira, because the deforestation-induced reduction in evapotranspiration is large enough to increase runoff and thus offset the reduction in precipitation. The effects of Amazon deforestation on river discharge are scale-dependent and vary across and within river basins. Reduction in precipitation due to deforestation is most severe at the end of the dry season. As a result, deforestation increases the dry-season length and the seasonal amplitude of water flow. These effects may aggravate the economic losses from large droughts and floods, such as those experienced in recent years (2005, 2010 and 2009, 2012, respectively).     

Prostatopexy as a treatment for urethral sphincter mechanism incompetence in male dogs

OBJECTIVES: The incidence of urinary incontinence due to urethral sphincter mechanism incompetence (USMI) in male dogs is relatively rare compared with the incidence in bitches, but the medical management of USMI in male dogs is less rewarding than in bitches. Attempts have been made to manage this condition surgically using either urethral bulking agents such as Teflon or by relocating the intrapelvic bladder neck to an intra-abdominal position by vas deferentopexy. This paper reports the response to prostatopexy in male dogs with USMI. METHODS: The response to prostatopexy was determined in nine severely incontinent male dogs with USMI that were followed up for periods ranging from 10 months to five years (mean 2.3 years). RESULTS: One dog was cured, four were improved, and no improvement in the frequency or degree of urinary incontinence occurred in the remaining four animals. No complications were seen in any of the dogs. CLINICAL SIGNIFICANCE: Prostatopexy may provide a further method of treating male dogs with USMI that do not respond to medical therapy.     

Associations among age, scrotal circumference, and proportion of morphologically normal spermatozoa in young beef bulls during an initial breeding soundness examination.

OBJECTIVE: To evaluate age and scrotal circumference as predictors of semen quality in young beef bulls. DESIGN: Cohort study. ANIMALS: 1,173 beef bulls < 15 months old. PROCEDURE: During initial breeding soundness examination, variables for bulls producing > or = 70% morphologically normal spermatozoa were compared with those for bulls producing < 70% morphologically normal spermatozoa. Mean and 95% confidence interval for age and scrotal circumference were constructed to detect differences between groups of bulls over all observations and within the 5 most common breeds. For these 5 breeds, chi 2 analysis was used to evaluate differences in the proportion of bulls that had values less than the population mean for scrotal circumference, age, and percentage of morphologically normal spermatozoa. Multivariate regression was used to quantify variation in the proportion of morphologically normal spermatozoa that could be explained by age and scrotal circumference. RESULTS: Mean (+/- SD) age and scrotal circumference differed significantly for bulls that produced > or = 70% morphologically normal spermatozoa (12.7 +/- 1.1 months and 35.6 +/- 2.7 cm) and bulls that produced < 70% morphologically normal spermatozoa (12.1 +/- 1.2 months and 34.8 +/- 3.3 cm). The proportion of bulls younger than mean age at first examination and the proportion producing > or = 70% morphologically normal spermatozoa differed among breeds. Age and scrotal circumference explained only 11% of the variation in semen quality. CLINICAL IMPLICATIONS: Among young beef bulls, those that were older and had larger testes were more likely to produce > or = 70% morphologically normal spermatozoa. Age and scrotal circumference were not sufficient predictors of semen quality.     

Crystallographic orientation of clinoenstatite produced by deformation of orthoenstatite

Uniaxial compression at 800 degrees C and 5 kilobars confining pressure of a specimen cored from a single crystal of orthoenstatite [(Mg,Fe)SiO(3)] produced fine lamellae 100 to 1000 angstroms thick of untwinned clinoenstatite. The two phases are joined along (100) planes and have b and c axes in common. The orientation of the clinoenstatite a axis contradicts several previously suggested transformation mechanisms and reduces the set of possible mechanisms by a factor of 2.     

Forest fragmentation, climate change and understory fire regimes on the Amazonian landscapes of the Xingu headwaters

Understory fire modeling is a key tool to investigate the cornerstone concept of landscape ecology, i.e. how ecological processes relate to landscape structure and dynamics. Within this context, we developed FISC??a model that simulates fire ignition and spread and its effects on the forest carbon balance. FISC is dynamically coupled to a land-use change model to simulate fire regimes on the Amazonian landscapes of the Xingu Headwaters under deforestation, climate change, and land-use management scenarios. FISC incorporates a stochastic cellular automata approach to simulate fire spread across agricultural and forested lands. CARLUC, nested in FISC, simulates fuel dynamics, forest regrowth, and carbon emissions. Simulations of fire regimes under modeled scenarios revealed that the major current and future driver of understory fires is forest fragmentation rather than climate change. Fire intensity proved closely related to the landscape structure of the remaining forest. While climate change may increase the percentage of forest burned outside protected areas by 30% over the next four decades, deforestation alone may double it. Nevertheless, a scenario of forest recovery and better land-use management would abate fire intensity by 18% even in the face of climate change. Over this time period, the total carbon balance of the Xingu??s forests varies from an average net sink of 1.6?ton?ha^?1?year^?1 in the absence of climate change, fire and deforestation to a source of ?0.1?ton?ha^?1?year^?1 in a scenario that incorporates these three processes.