Transcriptional response to alcohol exposure in Drosophila melanogaster

Background  

Alcoholism presents widespread social and human health problems. Alcohol sensitivity, the development of tolerance to alcohol and susceptibility to addiction vary in the population. Genetic factors that predispose to alcoholism remain largely unknown due to extensive genetic and environmental variation in human populations. Drosophila, however, allows studies on genetically identical individuals in controlled environments. Although addiction to alcohol has not been demonstrated in Drosophila, flies show responses to alcohol exposure that resemble human intoxication, including hyperactivity, loss of postural control, sedation, and exposure-dependent development of tolerance.     

The influence of microhabitat on availability of drifting invertebrate prey to a net-spinning caddisfly

SUMMARY. 1. Invertebrate drift was sampled at both a rockface and a deep pebble riffle site in streams draining both a clearcut and a forested catchment.
2. A sampler was designed to separate the bottom 2 cm of flow, encompassing the effective range of caddisfly (Hydropsychidae: Trichoptera) catchnets. from upper flow.
3. No significant difference in drift density (numbers per cubie metre) was seen between sites within each stream. However, numbers per square centimetre intake area per day at the rockface sites were 4 times higher in the clearcut and 10 times higher in the forested stream than at the pebble-riffle site.
4. Rockface habitat which had highest drift availability was also the site of maximum secondary production of the predaceous collector- filterer Parapsyche cardis in both streams studied.
5. Increased sediment load in the clearcut stream may influence the efficiency of utilization of invertebrate drift by collector-filterers.     

Bacterial swimming strategies and turbulence

Most bacteria in the ocean can be motile. Chemotaxis allows bacteria to detect nutrient gradients, and hence motility is believed to serve as a method of approaching sources of food. This picture is well established in a stagnant environment. In the ocean a shear microenvironment is associated with turbulence. This shear flow prevents clustering of bacteria around local nutrient sources if they swim in the commonly assumed "run-and-tumble" strategy. Recent observations, however, indicate a "back-and-forth" swimming behavior for marine bacteria. In a theoretical study we compare the two bacterial swimming strategies in a realistic ocean environment. The "back-and-forth" strategy is found to enable the bacteria to stay close to a nutrient source even under high shear. Furthermore, rotational diffusion driven by thermal noise can significantly enhance the efficiency of this strategy. The superiority of the "back-and-forth" strategy suggests that bacterial motility has a control function rather than an approach function under turbulent conditions.     

The question of uniqueness of ancient bacteria

Microorganisms are associated with a variety of ancient geological materials. However, conclusive proof that these organisms are as old as the geological material and not more recent introductions has generally been lacking. Over the years, numerous reports of the isolation of ancient bacteria from geological materials have appeared. Most of these have suffered from the fact that the protocol for the surface sterilization of the sample was either poorly defined, inadequate or rarely included data to validate the overall effectiveness of the sterilization protocol. With proper sterility validation and isolation protocol, a legitimate claim for the isolation of an ancient microbe can be made. Biochemical, physiological, or morphological data indicate that these ancient microbes are not significantly different from modern isolates. As the role (decomposition) of modern and ancient microbes has not changed over time, it is probably unreasonable to expect these organisms to be vastly different. A discussion on the reasons for the homogeneity of ancient and modern microbes is presented. Journal of Industrial Microbiology & Biotechnology (2002) 28, 32–41 DOI: 10.1038/sj/jim/7000174 Received 20 May 2001/ Accepted in revised form 16 June 2001     

Revision of the coral genus Acropora (Scleractinia: Astrocoeniina: Acroporidae) in Indonesia

The coral genus Acropora is reviewed from Indonesia for the first time, following detailed collections made at 131 sites and additional material collected from approximately 40 sites throughout the archipelago during the period 1993–6. Eighty-three species are recorded, four of these ( Acropora halmaherae, A. awi, A. plumosa and A. simplex ) new to science, six first described in 1994 and six in 1997. Records are compared with specimen-based records from localities worldwide. The species of Acrokora occurring in Indonesian waters include five recorded only from the Indian Ocean and Indonesia, seven recorded only from the Pacific Ocean, South China Sea and Indonesia, and a further 10 species apparently endemic to Indonesia, as well as widespread Indo-Pacific species. Two species ( A. jacquelineae Wallace, 1994 and A. batunai Wallace, 1996) are recorded only from north central Indonesia and Papua New Guinea, and two species ( A. russelli Wallace, 1994 and A. turaki Wallace, 1994) only from north central Indonesia and north western Australia. The findings contribute to a new view of the corals of the Indo-Pacific 'centre of diversity' as a composite fauna with origins in a number of events in space and time.     

Physiological and Anatomical Effects of Growth Temperature on Phaseolus vulgaris L. Cultivars

Two Phaseolus vulgaris L. cultivars were grown at 20/15, 25/20,and 30/25 °C day/night temperatures in growth chambers witha 16 h thermoperiod corresponding to the photoperiod. When thefirst trifoliolate leaf was fully expanded rates of CO₂ exchange(CER) were measured at 27 °C and saturating light usinginfrared gas analysis. Stomatal (r_s) and mesophyll resistances,CO₂ compensation points, activities of the enzymes ribulosebisphosphate carboxylase (RuBPCase), glycolate oxidase (GAO),malate dehydrogenase (MDH), and fructose-1, 6 diphosphate (FDP),chlorophyll content, Hill activities, and leaf anatomy at boththe light and electron microscope level were also investigatedin these leaves. Rates of CO₂ exchange in the light, transpiration rate, andchlorophyll content increased with increasing growth temperaturewhile leaf thickness, specific leaf weight, RuBPCase activity,compensation point, and stomatal resistance decreased. Mesophyllresistance also decreased when calculated assuming zero chloroplastCO₂ concentration (rm, o), but not when calculated assuminga chloroplast CO₂ concentration equal to the CO₂ compensationconcentration (rm, g). Average leaf size was maximal in 25/20°C plants while dark respiration, MDH activity, stomataldensity, and starch were minimal. The activities of GAO andFDP and Hill activity were not affected by temperature pretreatment.     

A Newly Revised Classification of the Protozoa*

SYNOPSIS The subkingdom Protozoa now includes over 65,000 named species, of which over half are fossil and ～ 10,000 are parasitic. Among living species, this includes ～ 250 parasitic and 11,300 free-living sarcodines (of which ～ 4,600 are foraminiferids); 1.800 parasitic and 5,100 free-living flagellates: ～ 5,600 parasitic “Sporozoa” (including Apicomplexa, Microspora, Myxospora, and Aseetospora); and ～ 2,500 parasitic and 4,700 free-living ciliates. There are undoubtedly thousands more still unmamed. Seven phyla of PROTOZOA are accepted in this classification—SARCOMASTIGOPHORA. LABYRINTHOMORPHA, APICOMPLEXA, MICROSPORA, ASCETOSPORA, MYXOSPORA, and CILIOPHORA. Diagnoses are given for these and for all higher taxa through suborders, and representative genera of each are named. the present scheme is a considerable revision of the Society's 1964 classification, which was prepared at a time when perhaps 48,000 species had been named. It has been necessitated by the acquisition of a great deal of new taxonomic information, much of it through electron microscopy. It is hoped that the present classification incorporates most of the major changes that will be made for some time. and that it will be used for many years by both protozoologists and non-protozoologists.