A Study of the Spotted Alfalfa Aphid and the Potato leafhopper and Their Abundance in Relation to Certain Climatic Condition in Five Specific Areas in South Dakota

The purpose of the portion of this paper pertaining to the spotted alfalfa aphid is to present the results of an ecological study dealing with the distribution and seasonal abundance of the insect. This study was established in four specific areas of four southeastern counties of South Dakota. Observations included the varying weather conditions and their effect on the aphid. Potato leafhoppers were also investigated. Actual proof of the potato leafhopper migratory theory was not forthcoming until 1951 when entomologists of the North Central States, with the aid of entomologists in certain Southern States, voluntarily collected the needed data in a cooperative survey. One of the steps outlined by the North Central States was the need for quantitative collections of the potato leafhopper along with notes on temperature, wind, and other weather conditions present at the time of collections. With these thoughts in mind, a study of this type was begun by this author on May 1, 1957, in these areas already discussed. Activities, periods of abundance, and population curves were developed and analyzed for both species

The Influence of Various Stress Conditions on Cholinesterase Levels of Cattle Treated with an Organophosphorus Insecticide

Six-to 8-months-old Hereford heifers categorized as grubby or grub-free calves were used for this research. Forty calves were purchased in 1968 and also in 1969. The grubby calves were obtained from Highmore, South Dakota, an area where calves have a history of heavy grub infestations of both Hypoderma bovis (L.) and Hypoderma lineatum (de Villers). The grub-free calves were purchased in Fargo, North Dakota. Calves raised in this area seldom are infested with cattle grubs. Specified groups of calves were subjected to 30 minutes of continuous exercise or the withholding of feed and water for 24 hours prior to treatment with a pour-on formulation of fenthion. The exercise and ration abstinence simulated stress conditions common to many livestock regions. Pretreatment and posttreatment jugular vein blood samples were evaluated to determine the effects of stress and fenthion on blood cholinesterase (ChE). According to statistical analysis, exercise and feed and water abstinence had little influence on ChE levels. Insecticide treatment produced the most consistent and significant variation in ChE. Fluctuations in ChE levels suggest that fenthion absorption occurs within 24 to 48 hours following treatment. Generally, insecticide influence was apparent throughout each of the 4 research phases in 1968 and 1969. Cattle origin and year also contributed to major ChE depression. Animal toxicosis was minimal throughout this study. One calf did display typical subacute organophosphate side effects. Animal reaction to the insecticide climaxed at 26 hours posttreatment and recovery was uneventful

A genome-wide linkage scan for iron phenotype quantitative trait loci: The HEIRS family study

Iron overload phenotypes in persons with and without hemochromatosis are variable. To investigate this further, probands with hemochromatosis or evidence of elevated iron stores and their family members were recruited for a genome-wide linkage scan to identify potential quantitative trait loci (QTL) that contribute to variation in transferrin saturation (TS), unsaturated iron-binding capacity (UIBC), and serum ferritin (SF). Genotyping utilized 402 microsatellite markers with average spacing of 9 cM. A total of 943 individuals, 64% Caucasian, were evaluated from 174 families. After adjusting for age, gender, and race/ethnicity, there was evidence for linkage of UIBC to chromosome 4q logarithm of the odds (LOD) =2.08, p =0.001) and of UIBC (LOD =9.52), TS (LOD =4.78), and SF (LOD =2.75) to the chromosome 6p region containing HFE (each p \u3c 0.0001). After adjustments for HFE genotype and other covariates, there was evidence of linkage of SF to chromosome 16p (LOD =2.63, p =0.0007) and of UIBC to chromosome 5q (LOD =2.12, p =0.002) and to chromosome 17q (LOD =2.19, p =0.002). We conclude that these regions should be considered for fine mapping studies to identify QTL that contribute to variation in SF and UIBC. © 2007 The Authors Journal compilation © 2007 Blackwell Munksgaard