A survey of needle handling practices and needlestick injuries in veterinary technicians

A survey of veterinary technicians identified that needlestick injuries are very common, with 210/226 (93%) technicians reporting at least one needlestick injury over the course of their career. One hundred sixty-seven (74%) had experienced a needlestick injury during the preceding year. Exposure to animal blood and various drugs was common. It was particularly concerning that needlestick injuries involving chemotherapeutic agents and prostaglandin were reported. Eight (3.5%) technicians had required medical care for a needlestick injury and 2 (0.8%) had lost time at work. The approach to sharps handling and needlestick injury avoidance was poor and most needlestick injuries had not been reported to employers. Measures need to be undertaken to improve sharps handling practices to reduce the number of needlestick injuries among veterinary technicians.     

Simulating restoration strategies for a southern boreal forest landscape with complex land ownership patterns

Restoring altered forest landscapes toward their ranges of natural variability (RNV) may enhance ecosystem sustainability and resiliency, but such efforts can be hampered by complex land ownership and management patterns. We evaluated restoration potential for southern-boreal forests in the ∼2.1 million ha Border Lakes Region of northern Minnesota (U.S.A.) and Ontario (Canada), where spatially distinct timber harvest and fire suppression histories have differentially altered forest conditions (composition, age–class distribution, and landscape structure) among major management areas, effectively resulting in forest landscape “bifurcation.” We used a forest landscape simulation model to evaluate potential for four hypothetical management and two natural disturbance scenarios to restore forest conditions and reduce bifurcation, including: (1) a current management scenario that simulated timber harvest and fire suppression practices among major landowners; (2) three restoration scenarios that simulated combinations of wildland fire use and cross-boundary timber harvest designed to emulate natural disturbance patterns; (3) a historical natural disturbance scenario that simulated pre-EuroAmerican settlement fire regimes and windthrow; and (4) a contemporary fire regime that simulated fire suppression, but no timber harvest. Forest composition and landscape structure for a 200-year model period were compared among scenarios, among major land management regions within scenarios, and to six RNV benchmarks. The current management scenario met only one RNV benchmark and did not move forest composition, age–class distribution, or landscape structures toward the RNV, and it increased forest landscape bifurcation between primarily timber-managed and wilderness areas. The historical natural disturbance scenario met five RNV benchmarks and the restoration scenarios as many as five, by generally restoring forest composition, age–class distributions, and landscape structures, and reducing bifurcation of forest conditions. The contemporary natural disturbance scenario met only one benchmark and generally created a forest landscape dominated by large patches of late-successional, fire-prone forests. Some forest types (e.g., white and red pine) declined in all scenarios, despite simulated restoration strategies. It may not be possible to achieve all objectives under a single management scenario, and complications, such as fire-risk, may limit strategies. However, our model suggests that timber harvest and fire regimes that emulate natural disturbance patterns can move forest landscapes toward the RNV.     

Genetic determinants of pathogenesis by feline infectious peritonitis virus

Feline infectious peritonitis (FIP) is a fatal, immune-augmented, and progressive viral disease of cats associated with feline coronavirus (FCoV). Viral genetic determinants specifically associated with FIPV pathogenesis have not yet been discovered. Viral gene signatures in the spike, non-structural protein 3c, and membrane of the coronavirus genome have been shown to often correlate with disease manifestation. An "in vivo mutation transition hypothesis" is widely accepted and postulates that de novo virus mutation occurs in vivo giving rise to virulence. The existence of "distinct circulating avirulent and virulent strains" is an alternative hypothesis of viral pathogenesis. It may be possible that viral dynamics from both hypotheses are at play in the occurrence of FIP. Epidemiologic data suggests that the genetic background of the cat contributes to the manifestation of FIP. Further studies exploring both viral and host genetic determinants of disease in FIP offer specific opportunities for the management of this disease.     

Leaf area index response of four obsolete and four modern cotton cultivars to two nitrogen levels

The optimal nitrogen (N) rate for cotton (Gossypium hirsutum L.) production in the late 20th century is greater than it was in the middle of the century (112 versus 27 kg ha^‐1). Part of the reason for this difference is that modern cultivars exhibit a greater harvest index than obsolete cultivars. This greater harvest index helps to allow modern cultivars to utilize greater N rates. However, factors other than harvest index, such as the development of leaf area in response to N, may also play an important role. Therefore, the objective of this study was to characterize leaf area index (LAI) of four obsolete and four modern cultivars at a low and high fertilizer N level. Cotton was grown in the field for two years (1992 and 1993) with two locations each year. The locations were a Beulah fine sandy loam and a Dubbs silt loam. Two preplant fertilizer‐N rates were used, a low (22 kg N ha^‐1) and a high(112 kg N ha^‐1). Leaf area index was determined at three stages in each year (early, mid, and late season). Yield was determined at maturity. Averaged across years, locations, and cultivars, late‐season LAI increased from 2.32 at 22 kg N ha^‐1 to 3.15 at 112 kg N ha^‐1 by late season. In 1992, modern and obsolete cultivars had similar LAI responses to N at early and mid season but by late season, LAI of modern cultivars was greater under high N than the obsolete cultivars (3.53 versus 2.95). Lint yield of the four modern cultivars was 372 kg ha^‐1 greater than the four obsolete cultivars at 112 kg N ha^‐1 and 289 kg lint ha^‐1 greater at 22 kg N ha^‐1 in 1992. The LAI response to N level of the modern cultivars was similar to that of obsolete cultivars in 1993 at all three sampling dates. In 1993, the lint yield of modern cultivars was 238 kg ha^‐1 greater than obsolete cultivars under 112 kg N ha^‐1 and 182 kg lint ha^‐1 at 22 kg N ha^‐1. In summary, our results best support the hypothesis that the higher yield of modern cultivars at high fertilizer N is unrelated to their LAI.     

Starter fertilizer effects on grain sorghum hybrids grown on a soil high in residual phosphorus in a no‐tillage environment

Conservation tillage crop production systems have become common in the central Great Plains because they reduce soil erosion and increase water‐use efficiency. The high residue levels associated with no‐tillage systems can cause soils to be cool and wet which can reduce nutrient uptake and growth of crops. Starter fertilizer applications have been effective in improving nutrient uptake even on soils high in available nutrient elements. Resent research indicates that corn (Zea mays L.) hybrids differ in their responses to starter fertilizer. No information is currently available concerning grain sorghum [Sorghum bicolor (L.) Moench] hybrid response to starter fertilizer. The objective of this study was to evaluate grain sorghum hybrid responses to starter fertilizer in a no‐tillage environment on a soil high in available phosphorus (P). This field experiment was conducted from 1995 to 1997 at the North Central Kansas Experiment Field, located near Belleville, on a Crete silt loam soil (fine, montmorillonitic, mesic, Pachic Arguistoll). Treatments consisted of 12 grain sorghum hybrids and two starter fertilizer treatments. Fertilizer treatments were starter fertilizer [34 kg nitrogen (N) and 34 kg P₂O₅ ha^‐1] or no starter fertilizer. Starter fertilizer was applied 5 cm to the side and 5 cm below the seed at planting. Immediately after planting, N was balanced on all plots to give a total of 168 kg N ha^‐1. In all three years of the experiment, grain yield, total P uptake (grain plus stover), grain moisture content at harvest, and days to mid‐bloom were affected by a hybrid x starter fertilizer interaction. Starter fertilizer consistently increased yields, reduced harvest grain moisture, improved total P uptake, and reduced the number of days needed from emergence to mid‐bloom of Pioneer 8505, Pioneer 8522Y, Pioneer 8310, Dekalb 40Y, Dekalb 48, Dekalb 51, Dekalb 55, and Northrup King 524, buthadno effect on Pioneer 8699, Dekalb 39Y, Northrup King 383Y, and Northrup King 735. When averaged over the three years, starter fertilizer increased grain yield of responding hybrids (hybrids in which the 3‐year average grain yield was significantly increased by the application of starter fertilizer) by 920 kg ha^‐1. In responding hybrids, starter fertilizer reduced grain moisture at harvest by 54 g kg¹ and also shortened the period from emergence to mid‐bloom by five days. Starter fertilizer increased V6 stage aboveground dry matter production and N and P uptake of all hybrids tested. Results of this work show that in high residue production systems even on soils high in available P, starter fertilizer can consistently increase yield of some hybrids, whereas other hybrids are not affected.     

Polydipsia in the dog--symposium. 2. Polydipsia and its relationship to pyometra

Abstract— —A generalised hormonal imbalance in adult bitches produces a hyperplasia of the endo-metrium and would seem to lower its resistance to secondary bacterial invaders. A variety of organisms, including E. coli, invade the endometrium and set up an inflammatory reaction with the formation of pus, i.e. pyometra. The clinical signs of pyometra include a polydipsia which is secondary to excessive fluid loss through the kidney. The histological examination of the kidneys from these cases of pyometra show extensive lesions. The capillary tuft and basement membrane of the glomerulus are thickened by a PAS-positive material. Similar, though less severe changes are seen in the renal tubules. All these lesions are said to be reversible following ovaro-hysterectomy. Some doubts are raised as to the specificity of these kidney changes. Résumé— —Un déséquilibre hormonal généralisé provoque chez la chienne adulte une hyperplasie de l'endomètre et semble réduire la résistance de celui-ci aux agressions bactériennes secondaires. Divers microbes, dont le colibacille, envahissent l'endomètre, pour y provoquer une réaction inflam-rnatoire pyogène, c'est-à-dire la pyométrie. Les manifestations cliniques de la pyométrie comprennent notamment la polydipsie, effet d'une déperdition hydrique excessive par la voie rénale. L'examen histologique du rein permet de constater, dans ces cas de pyométrie, d'importantes lésions rénales. Le floculus capillaire et las basale du glomérule sont épaissis par une substance positive à la coloration hématoxyline-acide périodique-Schiff. Les tubes urinaires présentent des altérations comparables, quoique moins marquées. L'ensemble de ces lésions serait réversibie à la suite de l'hystéro-ovariectomie. La spécificité de ces altérations rénales est douteuse à certains égards. Suivant une certaine hypothèse, la polyurie serait imputable à l'absorption de toxines d'origine utérine. Zusammenfassung— —Eine generalisierte hormonale Unausgeglichenheit bei erwachsenen Hün-dinnen erzeugt eine Hyperplasie des Endometriums und scheint dessen Widerstandsfähigkeit gegen sekundären Bakterienbefall herabzusetzen. Verschiedene Organismen einschliesslich E. coli können das Endometrium befallen und eine Entzündung mit Eiterbildung, d.h. Pyometra, hervorrufen. Zu den klinischen Zeichen von Pyometra gehört eine sekundäre Polydipsie nach übermässigem Flüssigkeitsverlust durch die Nieren. Die histologische Untersuchung der Nieren in diesen Fällen von Pyometra zeigt ausgedehnte Läsionen. Die Kapillarschicht und die Basalmembrane des Glomerulus sind durch ein PAS-positives Material verdickt. Ähnliche, doch weniger schwere Veränderungen sind an den Nierenkanälchen zu beobachten. Nach Ovariohysterectomie sollen alle diese Läsionen reversibel sein. Hinsichtlich der Spezifischkeit dieser Nierenveränderungen sind einiga Zweifel angemeldet worden. Es wurde auf die Möglichkeit hingewiesen, dass die Polyurie auf die Absorption von Toxinen aus dem Uterus zurückzuführen sein kann. It has been suggested that the polyuria is due to the absorption of toxins from the uterus.     

Use of spectral radiance for correcting nitrogen deficiencies and estimating soil test variability in an established bermudagrass pasture

The use of variable rate technology has become increasingly popular for applying plant nutrient elements. The most widely used method for determining variable fertilizer rates is presently based on soil testing and yield mapping. Three field studies (Bumeyville 1995, Burneyville 1996, and Ardmore 1996) were initiated in established Midland bermudagrass [Cynodon dacrylon (L) Pers.] pastures to determine the relationship between spectral radiance at specific wavelengths with forage nitrogen (N) removal and biomass, and to determine field variability of soil test parameters. Variable N (applied to 1.5 × 2.4 m subplots within 2.4 × 45.7 m main plots), fixed N and check treatments were evaluated at each location. Spectral radiance readings were taken in the red (671±6 nm), green (570±6 nm), and near infrared (NIR) (780±6 nm) wavelengths. The normalized difference vegetation index (NDVI) was calculated as NIR‐red/NIR+red. Variable N rates were applied based on NDVI. The highest fixed variable N rate was set at 224, 336, and 672 kg N ha^‐1 for Burneyville, 1995, 1996, and Ardmore, 1996, respectively. At Bumeyville, soil samples were collected in all variable rate plots (1.5 × 2.4 m) and analyzed for various soil test characteristics. NDVI, red, green, and NIR spectral radiance readings were correlated with bermudagrass forage N removal and yield. Correlation of forage yield and N removal with red, NIR, and NDVI were best with maximum forage production, however, when forage production levels were low correlation decreased dramatically for the red wavelength compared with NIR and NDVI. Forage yield and forage N removal in variable rate treatments increased when compared to the check while being equal to the half‐fixed and fixed rates where higher N rates were applied. Also, variability about the mean in variable rate plots was significantly lower than half‐fixed and fixed rates which supports adjusting N rates based on indirect NDVI measurements. Variable N rate plots reduced fertilizer inputs by 60% and produced the same yield as fixed rate plots, while fixed and half‐fixed rates did not increase N content in the forage over that of the variable rate treatment. Soil sample data collected from small consecutive plots (<4 m²) was extremely variable indicating that intense sampling would be needed if variable fertilizer application were to be based on soil test results.