Satellite measurements reveal persistent small-scale features in ocean winds

Four-year averages of 25-kilometer-resolution measurements of near-surface wind speed and direction over the global ocean from the QuikSCAT satellite radar scatterometer reveal the existence of surprisingly persistent small-scale features in the dynamically and thermodynamically important curl and divergence of the wind stress. Air-sea interaction over sea surface temperature fronts throughout the world ocean is evident in both the curl and divergence fields, as are the influences of islands and coastal mountains. Ocean currents such as the Gulf Stream generate distinctive patterns in the curl field. These previously unresolved features have important implications for oceanographic and air-sea interaction research.     

Cerebrospinal fluid analysis and magnetic resonance imaging in the diagnosis of neurologic disease in dogs: a retrospective study

BACKGROUND: Diagnosis of central nervous system (CNS) abnormalities in dogs can be challenging antemortem. Historically, cerebrospinal fluid (CSF) analysis has been used for routine diagnostic evaluation of animals with suspected neurologic disease; however, with increasing availability of magnetic resonance (MR) imaging, the need for concurrent CSF analysis may be questioned. OBJECTIVE: The purpose of this study was to retrospectively assess and compare the diagnostic information contributed from MR imaging and CSF analysis in a population of dogs presenting with neurologic disease. METHODS: Results of concurrent MR imaging and CSF analysis were evaluated in dogs presented for neurologic diseases. Based on clinical diagnosis, the sensitivity of CSF analysis and MR imaging for detecting a nervous system abnormality was calculated. Dogs with diagnoses confirmed by other diagnostic modalities were also evaluated separately. RESULTS: A total of 256 dogs were included in the study. For clinical diagnoses in which abnormalities were expected, MR imaging abnormalities were found in 89% and CSF abnormalities in 75% of dogs; CSF abnormalities were more common than MR imaging abnormalities only in inflammatory CNS disease. The majority of CSF abnormalities were nonspecific; an etiologic diagnosis was determined in only 2% of CSF samples. MR imaging excelled in detecting structural disorders, revealing 98% of vertebral abnormalities. In confirmed cases (n = 55), 76% of MR images and 9% of CSF samples were diagnostic. When intervertebral disk disease (IVDD) and vertebral malformation were excluded from analysis (n = 16 remaining), 25% of MR images and 6% of CSF cytology results were highly indicative of the confirmed diagnoses; CSF titer results provided the diagnosis in 25% of these cases. CONCLUSION: CSF analysis may not be necessary when MR findings of IVDD or vertebral malformation/instability are obvious; however, when the cause of neurologic disorder is uncertain, concurrent MR imaging and CSF analysis provides the greatest assistance in establishing a clinical diagnosis.     

Effects of salinomycin on ruminal characteristics and performance of grazing beef steers

Grazing trials were conducted for 2 yr using weanling Brahman crossbred beef steers to evaluate graded levels of salinomycin (0, 50, 100 or 150 mg. head-1.d-1) for 161 d and to evaluate salinomycin in a free-choice mineral supplement (99 d). The 40 and 48 steers in trials 1 and 2 had average initial weights of 198 and 285 kg, respectively. In trial 1, steers were group-fed to consume either 0, 50, 100 or 150 mg of salinomycin.head-1.d-1 in .9 kg ground corn while grazing bermudagrass pastures. Both linear (P less than .01) and quadratic (P less than .05) effects were observed for steer performance as salinomycin level increased from 0 to 150 mg.head-1.d-1. Linear increases (P less than .01) in ruminal NH3-N (mg/100 ml) and in the molar proportion of propionate and decreases (P less than .01) in butyrate and acetate/propionate were detected. In trial 2, mineral supplements with and without salinomycin were fed free-choice to steers on bermudagrass pasture. The mean salinomycin intake of 38 mg.head-1.d-1 was lower than anticipated as a result of the instability of salinomycin in the mineral supplement and the slightly lower intake (65 g/d) than anticipated (75 g/d). Performance of steers was not influenced by salinomycin supplementation in trial 2. The ionophore salinomycin at intakes over 50 mg.head-1.d-1 appears to increase the performance of steers grazing bermudagrass pasture.     

Tasco-Forage: III. Influence of a seaweed extract on performance, monocyte immune cell response, and carcass characteristics in feedlot-finished steers

Tall fescue (Festuca arundinacea Schreb.) infected with the endophyte Neotyphodium coenophialum ([Morgan-Jones and Gams] Glenn, Bacon, and Hanlin) causes fescue toxicosis in cattle grazing the forage, but effects of the endophyte were considered to be abated soon after removal of the animals from pastures. Tasco-Forage, a proprietary extract from the brown seaweed Ascophyllum nodosum, is a known source of cytokinins and has increased antioxidant activity in both plants and the animals that graze the forage. Tasco was applied at 0 and 3.4 kg/ha to infected and uninfected tall fescue pastures in Virginia and Mississippi. Forty-eight steers grazed the pastures at each location during each of 2 yr (n = 192) before being transported to Texas for feedlot finishing. On arrival at the feedlot, steers from Tasco-treated pastures had higher (P < 0.01) monocyte phagocytic activity and tended (P < 0.07) to have higher major histocompatibility complex class II expression than steers that grazed the untreated pastures. A depression (P < 0.05) in monocyte immune cell function due to grazing infected fescue was detected throughout the feedlot finishing period but was reversed by Tasco. Rectal temperatures were elevated (P < 0.07) in steers that had grazed the infected tall fescue when they arrived in Texas, but by d 14 no difference was detected. However, by d 28 the temperature effects of infected tall fescue were reversed. Steers that had grazed infected fescue had lower (P < 0.01) rectal temperatures on d 112 of the feedlot period, demonstrating a much longer-lasting effect of the endophyte on thermoregulatory mechanisms than previously thought. Steers that had grazed Tasco-treated pastures had higher (P < 0.01) rectal temperatures on d 56 than steers that had grazed untreated fescue. Steers that had grazed the Tasco-treated pastures had higher marbling scores (P < 0.05) regardless of the endophyte, but no effect of Tasco or endophyte on gain was measured. Our data suggest that Tasco application to tall fescue pastures alleviated some of the negative effects of tall fescue toxicity.     

Nest-site selection by cavity-nesting birds in relation to postfire salvage logging

Large wildfire events in coniferous forests of the western United States are often followed by postfire timber harvest. The long-term impacts of postfire timber harvest on fire-associated cavity-nesting bird species are not well documented. We studied nest-site selection by cavity-nesting birds over a 10-year period (1994–2003), representing 1–11 years after fire, on two burns created by mixed severity wildfires in western Idaho, USA. One burn was partially salvaged logged (the Foothills burn), the other was primarily unlogged (the Star Gulch burn). We monitored 1367 nests of six species (Lewis’s Woodpecker Melanerpes lewis, Hairy Woodpecker Picoides villosus, Black-backed Woodpecker P. arcticus, Northern Flicker Colaptes auratus, Western Bluebird Sialia mexicana, and Mountain Bluebird S. currucoides). Habitat data at nest and non-nest random locations were characterized at fine (field collected) and coarse (remotely sensed) spatial scales. Nest-site selection for most species was consistently associated with higher snag densities and larger snag diameters, whereas wildfire location (Foothills versus Star Gulch) was secondarily important. All woodpecker species used nest sites with larger diameter snags that were surrounded by higher densities of snags than at non-nest locations. Nests of Hairy Woodpecker and Mountain Bluebird were primarily associated with the unlogged wildfire, whereas nests of Lewis’s Woodpecker and Western Bluebird were associated with the partially logged burn in the early years after fire. Nests of wood-probing species (Hairy and Black-backed Woodpeckers) were also located in larger forest patch areas than patches measured at non-nest locations. Our results confirm previous findings that maintaining clumps of large snags in postfire landscapes is necessary for maintaining breeding habitat of cavity-nesting birds. Additionally, appropriately managed salvage logging can create habitat for some species of cavity-nesting birds that prefer more open environments. Our findings can be used by land mangers to develop design criteria for postfire salvage logging that will reserve breeding habitat for cavity-nesting birds.     

Prevalence and causes of ram epididymitis in Utah

Palpation of the testicles and epididymides was used to determine the prevalence of ram epididymitis (RE) in Utah range flocks over a 5-year period. Of 62 range flocks examined, 58 had rams with palpable lesions. A comparison was made of prevalence by right vs left testicle involvement, but no significant difference was found. Culling all rams with palpable lesions from the flock progressively reduced the annual incidence, but did not eliminate RE from any flock. Semen and specimens of reproductive tract tissue were obtained from representative flocks for bacterial culture. Brucella ovis was found commonly in range flocks, but was not isolated from RE-affected rams in virgin, ram-producing flocks. In the ram-producing flocks, a gram-negative, pleomorphic rod-type organism was found. It was concluded that RE should be considered as 2 disease entities, based on the finding of 2 causative organisms and the management systems under which those organisms are found. Brucella ovis was the major cause in persistently infected range flocks, whereas the gram-negative pleomorphic rod-type organism is the apparent cause of RE in virgin, ram-producing flocks.     

Suspected primary hematomyelia in 3 dogs

Primary hematomyelia refers to hemorrhage occurring within the spinal cord without an identifiable etiology. Clinical signs, magnetic resonance imaging characteristics, and histopathological findings are described. Diagnosis was made through histological analysis and rule-outs for underlying factors. Following removal of the hematoma, neurologic deficits improved, although some residual deficits persisted.     

Relationships between soluble sugar concentrations in roots and ecosystem stress for first year sugar maple seedlings

Accumulation of reducing sugars (i.e., glucose and fructose) in plant roots has been consistently correlated with forest dieback and decline and, therefore, has potential as a biological indicator of ecosystem stress. In this study, the relationships between acidic deposition and “natural” (temperature, mycorrhizae, and nutrition) factors with first-year sugar maple seedling root sugar concentrations and growth were assessed in two sugar maple dominated forests in Michigan. Seedlings at the southern site (Wellston) had greater root growth, phosphorus, total sugar, and sucrose concentrations in roots, but lower reducing sugar concentration in roots. In addition, percent root length colonized by vesicular-arbuscular mycorrhizal fungi was less than that found for seedlings growing at the northern site (Alberta). Throughfall deposition of nitrate, sulfate, and hydrogen ions was not significantly correlated with seedling total or reducing sugar concentration. Total sugar concentration in seedling roots was positively correlated with air and soil temperatures at the southern site, but not at the northern site. Seedling tissue phosphorus concentration was correlated with total sugars at both sites, with sucrose at the southern site, and reducing sugars at the northern site. Mycorrhizal colonization rates at the Alberta site were positively correlated with reducing sugar concentration in seedling roots and negatively correlated with sucrose concentration. The results suggest that differences in seedling root sugar concentrations in these two forests are related to seedling root growth and are most likely due to ecological variables, such as available soil phosphorus, temperature, and growing season length through some complex interaction with mycorrhizae rather than acidic deposition stress.