South Indian zebu dwarf cattle show higher natural resistance to tick infestation compared to crossbreds: preliminary observations

The present study aimed to evaluate the influence of various factors on the host resistance of cattle against tick infestation in Kerala State, South India. The number of naturally infested semi-engorged female ticks present on the cattle was counted on a sample cattle population across the four regions of Kerala. Then, the animals were grouped based on the tick count. The chi-square test and Fisher exact test were used to identify the effects of genetic and non-genetic factors on tick burden in cattle. It was found that the Holstein Friesian crossbred and Jersey crossbred cattle had a significantly higher level of tick infestation than the indigenous Vechur breed (Bos indicus). No tick infestation was observed in indigenous Kasaragod Dwarf cattle (B. indicus). Tick infestation was more in heifers and dry animals than lactating animals. However, the sex of the animal and the stage of lactation did not influence the tick load. Tick infestation was also influenced by parity, grazing, and region.

Histoarchitecture of ovary of Haemaphysalis bispinosa during engorgement period

The ovary of Haemaphysalis bispinosa was of panoistic type with asynchronous development of oocytes. The wall of the ovary was composed of a layer of epithelial cells to which the oocytes were attached by means of pedicel cells with elongated nucleus. The oocytes were classified into stages I to V based on morphologic characteristics like size and shape, presence / absence of germ vesicle, cytoplasmic appearance, presence or absence of yolk granules and presence of chorion. Day wise changes were in the form of occurrence of oogonia from partially fed upto day zero of engorgement, presence of all stages of oocytes on day one and two after engorgement and onset of degenerative changes in oocytes from day three onwards. Degeneration was complete on day eight with the appearance of polymorphism, vacuolation, cytoplasmic blebbing and autophagic activity in oocytes.

Acaricidal activity of alkaloid fractions of Leucas indica Spreng against Rhipicephalus (Boophilus) annulatus tick

The acaricidal activity from alkaloid and non-alkaloid fractions of Leucas indica were studied against Rhipicephalus (Boophilus) annulatus tick using adult immersion test under laboratory conditions. For this purpose, the engorged female R.(B.) annulatus tick were exposed to two fold serial dilutions of alkaloid extract (50 mg/ml, 25 mg/ml, 12.5 mg/ml, 6 mg/ml and 3 mg/ml) using 'dipping method' in vitro. The efficacy was assessed by measuring the percentage of adult mortality, inhibition of fecundity and hatching rate. The alkaloid fraction of the extract produced concentration dependent delayed adult tick mortality. The extract at a concentration of 50 mg/ml demonstrated 66.67 per cent mortality and 55.16 per cent inhibition of fecundity. Nicotine was identified as one of the compounds of alkaloid fraction. However, it did not reveal any acaricidal activity when tested in vitro at concentrations ranging from 62.5-1000 μg/mL. Hence, the acaricidal action of L. indica is not due to nicotine. Non alkaloid fraction also did not reveal any acaricidal effects against R. (B.) annulatus tick.

Acaricidal effect of Cassia fistula Linn. leaf ethanolic extract against Rhipicephlaus (Boophilus) annulatus

The present study evaluates the acaricidal properties of crude ethanolic extract of Cassia fistula leaves for controlling Rhipicephalus (Boophilus) annulatus based on adult immersion test (AIT). The percentage of adult mortality, inhibition of fecundity and hatching of ova laid were studied at different concentrations of the extract ranging from 50 to 100 mg / ml. The results were compared using one-way ANOVA. The extract produced complete inhibition of hatching of eggs at concentrations above 80 mg / ml of the extract. Mortality of adult engorged female ticks and inhibition of fecundity were concentration dependent. The LC50 value of extract against R. (B.) annulatus was 97.1 mg / ml.

In vitro evaluation of acaricidal activity of fipronil against Haemaphysalis bispinosa based on adult immersion test

Fipronil is a phenylpyrazole family insecticide which mainly affects the nervous system of insects. In the present study, the in vitro acaricidal effects of the compound against the widely prevalent multihost tick, Haemaphysalis bispinosa was assessed. The lowest concentration at which complete adult tick mortality was observed was at 25 ppm while complete absence of egg mass observed at 10 ppm. Hundred per cent inhibition of fecundity was observed at 1 ppm while complete blocking of hatching of the laid ova was observed even at 500 ppb.

Effects of solvents and surfactants against Haemaphysalis bispinosa

As per the report published by FAO (2004), the tick population in India has developed resistance against all the available acaricides. Hence, newer methods of control including potential herbal agents are required to reduce the problems caused by the ticks. Most of the herbal extracts or their fractions are dissolved in polar or non-polar solvents or detergents before tested for acaricidal activity and these diluents should be of little acaricidal activity. In the present study, adult immersion test (AIT) was carried out on adult engorged female Haemaphysalis bispinosa ticks to detect the acaricidal activity of different solvents viz., nbutanol, glycerol, acetone, ethanol, methanol and surfactants (at 1 per cent dilution) like dimethyl sulphoxide (DMSO), tween 20 and triton X- 100. The study revealed that methanol was the least toxic solvent while tween 20 (1 per cent) was the least toxic detergent against H. bispinosa.

The role of working memory, field dependence, visual search, and reaction time in the left turn performance of older female drivers

Older drivers have difficulties at intersections, especially in their performance of left turns. Older females are especially at risk in intersection maneuvers. Information processing abilities have been most promising in explaining the crash involvement of elderly drivers. This study examines the relationship of field dependence, visual search skills, and working memory to the decision to make a left turn at an intersection as well as to gap choice. Participants included thirty-three women ranging in age from 61 to 84 years. The results show that working memory plays a very important role in left-turn performance. Implications for appropriate interventions are discussed.

Cerebral uric acid increases following experimental traumatic brain injury in rat

Following traumatic brain injury (TBI), cortical and thalamic areas were analyzed histologically and by high-performance liquid chromatography with electrochemical detection for uric acid at various survival times. Following TBI, cortical uric acid was elevated by ten-fold at 24 and 48 h, but not at 1 h post-TBI. Histological evidence of neurodegeneration was found not only in cortex but also in the anteroventral thalamus. These data suggest that as in stroke, uric acid measurements may be a convenient and sensitive method for measuring peroxidative status in TBI.

Determinants of birth intervals in Kerala: an application of Cox's hazard model

"The present study is an attempt to delineate the differences in the patterns and determinants of birth intervals which appear highly relevant in a transitional population such as Kerala [India]. In this country two comparable surveys, with a period difference of 20 years, were conducted. The study tries to estimate the effects of socio-economic, demographic and proximate variables using Cox's proportional hazard model. For the former data-set, socio-economic variables have [a] significant effect on birth intervals, while for the latter data proximate variables are the significant determinants of birth intervals." (SUMMARY IN ITA AND FRE)

A novel microdialysis probe designed for clinical use: potential analytical and therapeutic applications

Significant obstacles to the use of microdialysis in the clinic for diagnostic or therapeutic purposes include the production of dedicated entry port through the skull and the formation of a tract by the insertion of a probe into the parenchyma. We have developed a microdialysis probe that is minimally invasive and can be combined with an intracranial pressure probe, recording electrode, or other intracranial probe, that is minimally invasive. Yet the surface area of this probe is very high, permitting high recovery efficiencies even at relatively high flow rates. This probe design makes possible minimally invasive measurement of the peroxidation product, uric acid, and excitatory amino acids, two analytes that increase in experimental traumatic brain injury in animals. Moreover, its large surface area makes therapeutic applications of microdialysis probes in the brain potentially feasible. A pilot evaluation of the ability of microdialysis to have therapeutic benefit in limiting experimental excitotoxin lesions induced in rat striatum by N-methyl-D-aspartate (NMDA) is reported.

A human factors analysis of ADL activities: a capability-demand approach

Older adults frequently encounter difficulties performing daily living activities. Often times these difficulties arise because environmental demands create barriers which hinder task performance. Currently, there is little empirical data that relate environmental demands to functional capabilities of older adults. The concepts and methods of Human Factors Engineering can be used to accomplish this goal. Human Factors views task performance within a systems context and maintains that successful task performance is dependent on a match between task demands and human capabilities. This article will discuss how Human Factors methodologies can be used to analyze problems encountered by older adults performing routine activities. Data from a study concerned with identifying physiological demands associated with personal and instrumental activities of daily living will be used to demonstrate the utility of using this approach.