Heterogonic development of the head, thorax and abdomen in Gryllus domesticus (Orthoptera:Gryllidae)

The heterogonic development of the three basic divisions of the body (head, thorax and abdomen) of Gryllus domesticus , was studied. The relationships in the linear dimensions of each of these parts with the standard parameter (absolute body length) were established through regression equations and the cephalosomatic, thoraco-somatic and abdomeno-somatic ratios. Of the body parts investigated the head was found to be the most heterogonic component followed by the abdomen and the thorax. The heterogonic development in the insect body seemed to be the result of varying intensities of the growth potential of different anatomical locations.     

An entomological investigation of the likely impact of cattle ownership on malaria in an Afghan refugee camp in the North West Frontier Province of Pakistan

Abstract. Field trials were undertaken to determine the effect of close proximity of humans to livestock on the human biting rates exhibited by various anophelines. The results indicate that proximity to cattle and to goats increases the subject's chances of being bitten by anophelines. Man-biting by Anopheles stephensi rose by 38% (8–68% CI) in the presence of a cow, and by 50% (16–84% CI) in the presence of two goats. Other species exhibited similar trends. These findings explain the results of an earlier trial which revealed that malaria prevalence was higher amongst families that kept cattle than those that did not.
The findings are discussed in relation to existing information regarding the host preferences of local anophelines and classic theories regarding zooprophylaxis. Our findings suggest that animals are only likely to have a worthwhile prophylactic affect when the vector is zoophilic, and then only when the animals are deployed to form a barrier between that vector and man. In situations where deployment of livestock to form a zoobarrier is impractical, the livestock should be located as far from man as possible.     

SIMPLIFIED CAPACITANCE MONITORING FOR THE DETERMINATION OF CAMPYLOBACTER SPP. GROWTH RATES

Capacitance monitoring is commonly used as an efficient means to generate growth curves of bacterial pathogens. However, the use of capacitance monitoring with Campylobacter spp. was previously determined to be difficult due to the complexity of the required media. We investigated capacitance monitoring using a simplified medium for the efficient and reproducible construction of growth curves for Campylobacter spp . It was determined that Campylobacter spp. should initially be propagated on Mueller Hinton plates in a microaerobic atmosphere (5% O₂, 10% CO₂, 85% N₂) at 37C for 24 h, followed by transfer to Mueller Hinton biphasic cultures for 6 h at 37C in a microaerobic atmosphere. Serial dilutions of the Campylobacter spp. cultures should be used for inoculation of Bactometer wells that contain 1 mL Mueller Hinton broth supplemented with 0.1 M sodium pyruvate for the completion of Campylobacter spp. growth curves with the Bactometer.

PRACTICAL APPLICATIONS

Growth rates can vary greatly among Campylobacter isolates; therefore, the rapid and reproducible methods described will prove useful in studies where the generation of growth curves is critical for subsequent experimental analyses.     

FIRST REPORT OF THE FERTILE PLANT GENUS UMKOMASIA FROM LATE PERMIAN BEDS IN INDIA AND ITS BIOSTRATIGRAPHIC SIGNIFICANCE

Abstract:  The genus Umkomasia Thomas, a female fructification of Dicroidium , is reported from Late Permian beds exposed in the Behra Rivulet near the village of Karaonda in the Tatapani-Ramkola Coalfield, Chhattisgarh, India. This is the first record of this genus from the Late Permian, and from Indian Gondwana. Two species have been recognized: Umkomasia polycarpa Holmes and U. uniramia Axsmith, Taylor, Taylor and Cuneo. The find suggests that the genus Dicroidium appeared in the Late Permian before reaching its acme in the Middle–Upper Triassic.     

Molecular Identification and Prevalence of Entamoeba histolytica,Entamoeba dispar and Entamoeba moshkovskii in Erbil City,Northern Iraq

The present study was conducted to evaluate the infection rates of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii among asymptomatic individuals in Erbil City, northern Iraq. The research intent was to discover whether pathogenic or nonpathogenic species cause a high rate of symptomless Entamoeba infections. Stool samples were microscopically examined, and the 18S-rRNA gene was targeted utilizing the nested PCR technique in the positive specimens. Initial results based on morphological features showed that the Entamoeba prevalence rate was 7.4%. Significantly higher rates of infections were seen in females than in males and in low-income people than in moderate-income people. The incidence rates among the asymptomatic individuals, as determined by molecular analysis, were as follows: E. histolytica – 6%, E. dispar – 4.3%, and E. moshkovskii – 0.3%. Of all the Entamoeba positive samples, a single infection with E. histolytica was identified in 41.4% samples; the single infection with E. dispar in 18.6% samples, 35.7% samples had mixed infections with two Entamoeba species, and 4.3% had mixed infections with three species. The current study concluded that 7.4% of healthy people, who live in the endemic area under investigation, carry Entamoeba species asymptomatically. Additionally, the majority of asymptomatic Entamoeba infections were caused by the pathogenic E. histolytica (81.4%) compared to E. dispar (58.6%), and E. moshkovskii with the lowest rate of infection. Single and co-infections with E. histolytica and E. dispar were noted. E. moshkovskii, which was identified for the first time in the region, was only seen in mixed infections.Key words: Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, epidemiology, asymptomatic infections     

Laboratory experiments on the schooling and feeding behaviour of Trichogaster fasciatus (Pisces: Perciformes)

Laboratory experiments were performed on the schooling and feeding behaviour of Trichogaster fasciatus . There was a tendency on the part of individuals of similar size to school together; the instinct being stronger in younger specimens. Unavailability of similar-sized individuals led to schooling by members of different size-groups. Column feeding was exhibited by the fish. While feeding at the bottom, the fishes formed angles varying from 30°90°. Larger individuals formed a right angle more often than younger members of the species. Optimum degree of crowding seemed necessary for active feeding as confinement of single individual, or overcrowded condition, both resulted in a decline of feeding activity.