The effect of neutering on the risk of urinary incontinence in bitches - a systematic review

An increased risk of urinary incontinence in bitches has often been associated with previous ovariohysterectomy but remains controversial. The objective of this study was to evaluate the strength of evidence for an association between neutering or age at neutering and urinary incontinence in bitches and to estimate the magnitude of any effect found. A systematic review of peer-reviewed original English analytic journal articles was conducted, based on Cochrane guidelines (Higgins and Green 2009) Of 1,853 records screened, seven studies were identified that examined the effect of neutering or age at neutering on the risk of urinary incontinence but four were judged to be at high risk of bias. Of the remaining three studies, which were at moderate risk of bias, there was some weak evidence that neutering, particularly before the age of three months, increases the risk of urinary incontinence. However, overall the evidence is not consistent nor strong enough to make firm recommendations on the effect of neutering or age at neutering on the risk of urinary incontinence.     

The effect of neutering on the risk of mammary tumours in dogs--a systematic review

A commonly-stated advantage of neutering bitches is a significant reduction in the risk of mammary tumours, however the evidence for this has not previously been assessed by systematic review. The objectives of this study were to estimate the magnitude and strength of evidence for any effect of neutering, or age of neutering, on the risk of mammary tumours in bitches. A systematic review was conducted based on Cochrane guidelines. Peer-reviewed analytic journal articles in English were eligible and were assessed for risk of bias by two reviewers independently. Of 11,149 search results, 13 reports in English-language peer-reviewed journals addressed the association between neutering/age at neutering and mammary tumours. Nine were judged to have a high risk of bias. The remaining four were classified as having a moderate risk of bias. One study found an association between neutering and a reduced risk of mammary tumours. Two studies found no evidence of an association. One reported "some protective effect" of neutering on the risk of mammary tumours, but no numbers were presented. Due to the limited evidence available and the risk of bias in the published results, the evidence that neutering reduces the risk of mammary neoplasia, and the evidence that age at neutering has an effect, are judged to be weak and are not a sound basis for firm recommendations.     

The risk of rinderpest re-introduction in post-eradication era

In 2011, ten years after the last reported outbreak, the eradication of rinderpest was declared. However, as rinderpest virus stocks still exist, there remains a risk of rinderpest re-introduction.     

Factors Affecting Brain Cholinesterase Activity in Bluegill (Lepomis Macrochirus)

Organophosphorus insecticides (OPs) are widely used to control crop pests, and can enter aquatic systems draining agriculturalwatersheds. Because OPs are highly toxic to aquatic organisms,monitoring is important, yet difficult due to the low persistenceof many OPs. Cholinesterase (ChE) inhibition can be used to monitor organisms' exposure to OPs and carbamates; however, highvariability in ChE activity may interfere with the ability of theassay to detect OP exposure. Several potential sources of variation in ChE activity, including water temperature, storage of samples, euthanasia method, and fish sex and size, were investigated in bluegill (Lepomis macrochirus). ChE activity did not vary significantly with water temperature in the range 20–31 °C, or following short-term storage ofeuthanized bluegill up to 8 h at 4 and 19 °C or long-term storage of brain homogenates up to 389 d at –198 °C. There was no difference in ChE activity by euthanasia method (spinal cord severing or anesthesia with Finquel®), nor by sex of fish. Mean ChE activity variedinversely with fish total length. Of the variables investigated in this study, only size needs to be restricted in fish collectedfor monitoring of OPs.     

Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest

Remotely sensed data and a Geographic Information System were used to compare the effects of clearcutting and road-building on the landscape pattern of the Bighorn National Forest, in north-central Wyoming. Landscape patterns were quantified for each of 12 watersheds on a series of four maps that differed only in the degree of clearcutting and road density. We analyzed several landscape pattern metrics for the landscape as a whole and for the lodgepole pine and spruce/fir cover classes across these maps, and determined the relative effects of clearcutting and road building on the pattern of each watershed. At both the landscape- and cover class-scales, clearcutting and road building resulted in increased fragmentation as represented by a distinct suite of landscape structural changes. Patch core area and mean patch size decreased, and edge density and patch density increased as a result of clearcuts and roads. Clearcuts and roads simplified patch shapes at the landscape scale, but increased the complexity of lodgepole pine patches. Roads appeared to be a more significant agent of change than clearcuts, and roads which were more evenly distributed across a watershed had a greater effect on landscape pattern than did those which were densely clustered. Examining individual watersheds allows for the comparison of fragmentation among watersheds, as well as across the landscape as a whole. Similar studies of landscape structure in other National Forests and on other public lands may help to identify and prevent further fragmentation of these areas.     

Rinsing of Saline Water from Road Salt in a Sandy Soil by Infiltrating Rainfall: Experiments,Simulations, and Implications

Saline melt water from road salt applications that has percolated into a fine sandy soil in winter is rinsed out of the soil by infiltrating rainwater in the following warmer seasons. This sequence of saturated and unsaturated flow processes associated with saline water transport in a fine sandy soil was studied by simulation and exploratory laboratory experiments. Experiments in soil columns of 300-μm sand revealed that two rinses of pure water, each of one pore volume, were sufficient to reduce the salt concentration by 99% of its original value in the soil column. Simulated time variations of salt concentration in the effluent from the column agreed with experimental results. Based on simulated and experimental results, a sandy soil must become saturated to experience pore water flow in order to efficiently rinse saline snowmelt water. Depending on the saturated hydraulic conductivity and the soil depth, days, weeks, or months of freshwater infiltration in summer are needed to rinse saline melt water from an unsaturated sandy soil after road salt applications in winter. This explains findings of significant salt concentrations in surface and shallow groundwater during summer months, long after road salt application and infiltration has ceased.