Harmonic radar: efficacy at detecting and recovering insects on agricultural host plants

BACKGROUND: In pest management research, harmonic radar systems have been largely used to study insect movement across open or vegetation‐poor areas because the microwave signal is attenuated by the high water content of vegetation. This study evaluated whether the efficacy of this technology is sufficient to track insects in vegetative landscapes. RESULTS: Field efficacy data were collected using portable harmonic microwave radar and electronic dipole tags mounted on adults of three economically important pests: Leptinotarsa decemlineata (Say), Diabrotica virginifera virginifera (LeComte) and Conotrachelus nenuphar Herbst. Detection and recovery of tagged Colorado potato beetles, plum curculios and western corn rootworms was high within and among potato plants, moderate within apple trees and high within, but not between, corn plants respectively. The efficacy of the radar depends on the ability of the operator to move around the host, scanning for a signal ‘sightline’ with the tagged insect among plant structures. CONCLUSION: The detection rate of tagged insects by harmonic radar systems is high enough to track the walking path of pests through low row crops such as potato, tall row crops such as corn or tall but well‐separated trees of orchard‐type crops by adapting the scanning procedure to the vegetative architecture. Copyright © 2010 Crown in the right of Canada. Published by JohnWiley & Sons, Ltd     

Effects of treadmill exercise on the transfer of plasma triglyceride into the ovary of the laying fowl

1. The effects of 90 min continuous treadmill exercise on the plasma-to-ovary transfer of 14C-labelled triglycerides in laying hens were examined. 2. Exercised birds showed a 4-fold increase in plasma free fatty acid concentration, a 15% decrease in plasma glucose concentration and unchanged plasma triglyceride concentration compared with resting controls. The mean plasma-to-ovary triglyceride transfer rate was approximately halved by exercise. 3. The surface area-specific triglyceride transfer rate was greatest for oocytes weighing 0.25-1.5 g and decreased with increasing oocyte size. The lowest rates were in the small (less than 0.25 g) white oocytes. This pattern was largely unaffected by exercise. 4. Factors that might be responsible for the reduction in triglyceride transfer into the oocytes during exercise include hormonal effects on the permeability of the oocyte envelope, increased competition for plasma lipids by the working muscles and reduced blood flow to the ovary, as a result of the release of vasoconstrictors.     

Comparison of three serologic techniques for detection of antibody to Mycoplasma pulmonis

A comparison of three micro-assay detection systems for naturally occurring and experimentally induced rat antibody to Mycoplasma pulmonis was performed. The micro-enzyme linked immunoabsorbent assay was found superior to counter immunoelectrophoresis or complement fixation techniques when comparing sensitivity, duration of antibody response, or technical requirements. The primary immune response was routinely detected at 3 weeks after antigen exposure when using the enzyme linked or complement fixation assays.     

Real-time non-invasive measurement of heart rate in working dogs: a technique with potential applications in the objective assessment of welfare problems

The Polar Sport Tester (Polar Electro OY) is a telemetric heart rate monitor designed for use in humans. Its usefulness as a monitor during training of guide dogs is assessed in this paper. Heart rates from six representative dogs at a similar stage of early training were recorded at 5-s intervals during a 15-20 min work session. The dogs were F1 Labrador Retriever x Golden Retrievers. They were chosen if their behaviour could be clearly categorized by their experienced trainers as either 'calm/non-stress prone' (Type A) or 'excitable/stress prone' (Type B) during work. Verbal recordings were made of environmental cues and behavioural responses in each dog. Variability in heart rate was significantly related to a subject's described temperament.     

The influence of the tracer injection–acquisition interval on the distribution of 99mTc-ECD in the brain of laboratory cats

Single-photon emission computed tomography (SPECT) can be used to study the regional distribution of the cerebral blood flow in the feline brain without interference of anesthetics. When the tracer, ^99mtechnetium-ethyl cysteinate dimer (^99mTc-ECD), is injected in the awake animal, the acquisition can be performed afterward under general anesthesia, whereas the tracer distribution still represents the regional cerebral blood flow (rCBF) in the awake animal. The aim of this study was to look at the in vivo stability of ^99mTc-ECD in the feline brain. For this purpose, 6 cats (n = 6) were used, and 3 serial acquisitions were performed starting at 40 (T40), 60 (T60), and 85 (T85) minutes after tracer injection. Total counts and perfusion indices (PIs), normalized to the total brain and to the cerebellum, were calculated. When T85 was compared with T40, total counts decreased, depending on the brain region, with 29% (left thalamus) to 51% (bulbus olfactorius). These regional differences in tracer clearance resulted in significantly altered PIs at T85 as compared with T40. This study shows that ^99mTc-ECD SPECT can be used in cats for studying the rCBF and that the clearance of ^99mTc-ECD in the feline brain is region dependent. As a result, the acquisition should be started between 40 and 60 minutes after tracer injection.     

Electroporation improves the immune response induced by a DNA vaccine against pseudorabies virus glycoprotein B in pigs

This study was performed to determine whether electroporation can be used to enhance the efficacy of a DNA vaccine against pseudorabies virus (PrV) in pigs. Immune responses to PrV were measured in pigs following a single intramuscular injection of plasmids encoding PrV glycoprotein B, with or without electroporation. Plasmid injection coupled with electroporation increased production of specific antibodies against PrV and peripheral blood mononuclear cells proliferated in response to stimulation with PrV glycoproteins. These results show that electroporation can improve the performance of a DNA vaccine against PrV in pigs. However, additional work is required to maximise the effectiveness of the vaccination protocol.     

Cardiopulmonary bypass in the cat

OBJECTIVE: To assess the physiologic response to, and acute survival of, cats undergoing cardiopulmonary bypass (CPB) and to evaluate the efficacy of a commercial human pediatric oxygenator system on cats weighing less than 6 kg. STUDY DESIGN: Experimental study. ANIMALS: Six intact male cats METHODS: Cats were placed on cardiopulmonary bypass by cannulating the cranial and caudal vena cavae and the carotid artery. The pediatric CPB circuit was primed with 150 mL of a balanced crystalloid solution. Venous drainage was enhanced by a controlled, vacuum-assist system. A cross-clamp was placed on the ascending aorta and cardiac arrest was induced by antegrade infusion of a cold cardioplegia solution. After 45 minutes of arrest time, the cross-clamp was removed and the cats were weaned off bypass and decannulated. No blood products were administered. Heart rate, mean arterial pressure (MAP), central venous pressure, arterial blood gas, hematocrit (HCT), total plasma protein concentration (TP), serum electrolyte concentrations, and activated clotting time (ACT) were measured at baseline period (BL), during CPB, 60 minutes after CPB (CPB 60) and 90 minutes after CPB (CPB 90). A complete blood count (CBC), blood chemistry profile, and urinalysis were performed at BL, during CPB, and CPB 90. Cats were euthanatized after CPB 90. RESULTS: Cardiopulmonary bypass resulted in a significant (P <.05) decrease in mean HCT (18.0%) and TP (2.3 gm/dL) at CPB 90 when compared to BL (30.5% and 6.0 gm/dL, respectively). The MAP at CPB 90 (54 mm Hg) was decreased from BL (94 mm Hg). The ACT increased from a mean of 124 seconds to > 400 seconds with heparinization and was reversed to 300 seconds with protamine. Mean platelet counts decreased from BL (369,000 /microL) to CPB 90 (94,500 /microL). Mean white blood cell counts decreased from 13,200 /microL at BL to 2,200 /microL at CPB 90. Upon reperfusion, 1 cat fibrillated but was successfully defibrillated. CONCLUSIONS: Cardiopulmonary bypass was performed successfully in 6 cats weighing less than 6 kg. Acute survival to 90 minutes after CPB was achieved in all 6 cats CLINICAL RELEVANCE: The ability to perform CPB in the cat may allow intracardiac repair of various heart defects in this species.     

Tuberculosis and brucellosis prevalence survey on dairy cattle in Mbarara milk basin (Uganda)

We determined the prevalence of tuberculosis and brucellosis reactors in the dairy herds in the Mbarara district of Uganda in 2002. This is one of the most important dairy-production areas of the country and includes both pastoral and agro-pastoral zones. A total of 340 (of 11,995) randomly selected herds were tested for tuberculosis, using the intradermal tuberculosis-skin test and 315 (of 10,562) herds tested for brucellosis using the serum Rose Bengal test.

The herd prevalence for tuberculosis reactors was 74.1% (95% confidence intervals 69, 78), the individual-animal prevalence was of 6.0% (5.6, 6.5) and within-herd range was 1–50% (up to 100% if suspicious reactors were included).

The herd prevalence for brucellosis was 55.6% (50, 61.2) individual-animal prevalence 15.8% (14.8, 16.7) and within-herd range 1–90%.

The reactor prevalence increased with the age of the animals for both tuberculosis and brucellosis.

Tuberculosis reactor prevalences were higher in animals from the agro-pastoral zone. However, the individual-animal and herd prevalences of brucellosis seroprevalences were higher in the pastoral zone.     

Good quality chicks from disinfected eggs

目前,良好的清洗和消毒被广泛地认为是孵化场优化1日龄苗鸡(Day Old Chick,DOC)生产的一种措施.良好的种蛋卫生已证明可提高DOC的存活率和质量.事实上,细菌通过蛋壳侵入种蛋的强穿透能力会影响孵化质量的诸多方面,如早期胚胎死亡率、蛋黄感染、出壳前的DOC死亡率,除此之外还有第1周中苗鸡极高的死亡率和不均匀性.