Time between death and discovery of remains, or postmortem interval (PMI), can be assessed using blow fly maggot age. Forensic entomologists rely on published, often nonlocal, species-specific developmental tables to determine maggot age. In a series of common garden experiments, we investigated the developmental rate variation between populations of Lucilia sericata collected from Sacramento, CA, San Diego, CA, and Easton, MA at 16 degrees C, 26 degrees C, and 36 degrees C. For the 16 degrees C trial the time measurement started at egg hatch, while for the higher temperatures the experiment began at oviposition; the wandering stage signified the endpoint for all experiments. The distribution of developmental times differed significantly (ANOVA, p < 0.001) between the three populations within each temperature treatment. We discovered that regional variation of developmental times within a blow fly species exists. This study demonstrates the importance of assembling local population-specific developmental tables when estimating larval age to determine PMI.

Most of the schedules suggested by researchers for irrigating wheat (Triticum aestivum L. em Thell) are not sufficiently simple to be adopted by farmers in general. Recently a more practicable approach based on the ratio of a fixed amount of irrigation water (IW) to pan evaporation, PAN‐E, (cumulative evaporation from US Weather Bureau class A pan less rain since previous irrigation) has been suggested. Several workers have advocated irrigation of wheat at definite growth stages. One possibility of further improving the water use efficiency could be a combination of these two approaches. We compared, in a two year field study, IW/PAN‐E ratios of 0.75 and 0.9 for scheduling irrigation to winter wheat irrespective of growth stage with (i) a combination of these ratios with growth and (ii) irrigation at five growth stages. IW/PAN‐E of 0.75 irrespective of growth stage produced as much grain yield as irrigation at five growth stages. But the former, as an average, received 12 cm less irrigation. There was no gain in the yield by combining the IW/PAN‐E with growth stages. These results indicate that irrigating wheat, sown after a presowing irrigation, on the basis of IW/PAN‐E, irrespective of growth stage, offers a practical means to economize irrigation water without reduction in yield.

Day-old broiler chicks found negative for maternal antibodies against inclusion body hepatitis (IBH) virus by agar gel precipitation test and viral antigen in cloacal swabs by dot enzyme immunoassay were divided into 6 groups of 20 chicks each. Group A was fed aflatoxin B1 at 1.25 ppm from 3 to 38 days of age; group O was fed ochratoxin A at 0.5 ppm from 3 to 38 days of age; group V was inoculated with 1 ml of IBH virus of titre log10 6.5 EID50 per 0.2 ml. Groups AV and OV were given aflatoxin B1 and ochratoxin A, respectively, and also infected with the virus. Group C served as control. There was mild enlargement and paleness of the liver up to 18 days post inoculation in group V; there were no lesions in group A; and there was gradual enlargement of the kidneys from 10 days post feeding of mycotoxin onwards in group O. In the combined groups AV and OV the gross lesions were slightly more severe. In group V, varying degrees of degenerative histopathological changes, congestion and haemorrhages were seen particularly in the liver, followed by the kidneys, bursa, spleen, myocardium and lungs, along with intranuclear inclusion bodies in the hepatocytes, mostly in the early stages of infection. Similar microscopic changes, but without inclusion bodies, were seen in groups A and O and the changes were pronounced in the later stages. In group O, the kidney lesions were more pronounced than the liver lesions. In the concurrently infected groups, AV and OV, the changes were similar but slightly more marked than in the corresponding individual groups. Inclusion bodies in hepatocytes were more frequent, more prominent and appeared earlier in the concurrent groups.

No abstract

Although an insufficient supply of water is commonly associated with reduced crop yields, the manner in which water deficits affect the functioning of many common field crops is not well established. The purpose of this study was to quantify the effects of a water deficit on some physiological processes of spring oats (Avena sativa L. ‘Jaycee’). The plants were subjected to water deficits under a field environment for 9 to 11 days at the boot stage, at anthesis through early grain formation stage, and at both stages in combination. Relative leaf water content (RLWC) as determined by the relative turgidity method was used as a measure of water deficit. Leaf diffusion resistance (LDR) was monitored using a diffusion porometer. The net photosynthetic rate (NPR) of the oat plants was determined using an infrared gas analyzer. Severe water stress at all stages of development studied caused about an 80% decline in NPR. LDR increased with a decrease in RLWC. Stress during boot stage reduced the photosynthetic sensivity of the plants to subsequent stress at the anthesis through early grain formation stage. On rewatering, LDR and RLWC recovered completely within 1 to 6 days; however, the net photosynthetic rate of plants stressed at the anthesis through grain formation stage showed a more gradual and incomplete recovery than plants stressed at other stages. The plants stressed during boot stage alone, but adequately watered thereafter, exhibited significantly higher NPR than the control plants. The results indicate that leaf diffusion resistance and net photosynthetic rate of oats show acute sensitivity to plant water deficits. Hence, these parameters hold promise as aids in determining permissible water deficit limits and in irrigation scheduling.