Agricultural spider decline: long-term trends under constant management conditions.

There is widespread evidence for a worldwide trend of insect decline, but we have much fewer data about recent temporal trends in other arthropod groups, including spiders. Spiders can be hypothesised to similarly decline because of trophic dependence on insects and being equally sensitive to local and global environmental changes. Background trends in arthropod populations can be verified if we decouple large-scale environmental transitions, such as climate change, from local factors. To provide a case study on baseline spider community trends, we observed changes in the spider community of an unsprayed alfalfa field and its margin 23 years apart under largely unchanged local conditions. We aimed to determine whether there are changes in spider abundance, species richness and mean species characteristics. Spider abundance per unit effort decreased dramatically, by 45% in alfalfa and by 59% in the margin, but species richness and most characteristics remained unchanged. Community composition in both habitats shifted and became more similar by the current study period. The population decline was especially marked in certain farmland species. We propose that in the absence of local causative factors, spider abundance decline in our study indicates a reduction of spider populations at landscape and regional scales.

The genome sequence of Drosophila melanogaster.

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

Comparative genomics of the eukaryotes.

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.

[Pharmacological prophylaxis of vestibulo-autonomous syndrome (motion sickness) in model investigations]. / Farmakologicheskaia profilaktika vestibulovegetativnogo sindroma (bolezni dvizheniia) v model'nykh issledovaniiakh.

The authors summarize results of multiyear investigations at the Institute of Biomedical Problems of induced motion sickness and development of prophylactic medicaments representing various classes of biologically active substances (choline blocking agents, sympathomimetics, antihistamines etc.) prescribed singularly or in an combination based on the knowledge of MS-provoking inter-receptor interactions and therapeutic effects of drugs.

An exploration of the sequence of a 2.9-Mb region of the genome of Drosophila melanogaster: the Adh region.

A contiguous sequence of nearly 3 Mb from the genome of Drosophila melanogaster has been sequenced from a series of overlapping P1 and BAC clones. This region covers 69 chromosome polytene bands on chromosome arm 2L, including the genetically well-characterized "Adh region." A computational analysis of the sequence predicts 218 protein-coding genes, 11 tRNAs, and 17 transposable element sequences. At least 38 of the protein-coding genes are arranged in clusters of from 2 to 6 closely related genes, suggesting extensive tandem duplication. The gene density is one protein-coding gene every 13 kb; the transposable element density is one element every 171 kb. Of 73 genes in this region identified by genetic analysis, 49 have been located on the sequence; P-element insertions have been mapped to 43 genes. Ninety-five (44%) of the known and predicted genes match a Drosophila EST, and 144 (66%) have clear similarities to proteins in other organisms. Genes known to have mutant phenotypes are more likely to be represented in cDNA libraries, and far more likely to have products similar to proteins of other organisms, than are genes with no known mutant phenotype. Over 650 chromosome aberration breakpoints map to this chromosome region, and their nonrandom distribution on the genetic map reflects variation in gene spacing on the DNA. This is the first large-scale analysis of the genome of D. melanogaster at the sequence level. In addition to the direct results obtained, this analysis has allowed us to develop and test methods that will be needed to interpret the complete sequence of the genome of this species. Before beginning a Hunt, it is wise to ask someone what you are looking for before you begin looking for it. Milne 1926

[The Jupiter-2 slow-rotation system]. / Medlennovrashchaiushchaiasia sistema "Iupiter-2".

The experience of space missions shows that functional disorders in crewmembers on the type of space motion sickness (SMS) may develop on the initial stage of flight. Longer exposure in micro-g causes a wide range of debilitative changes in the vital body systems. Artificial gravity produced by spacecraft rotation might be a universal tool to counteract the impacts of prolonged microgravity on the human body. However, the significance of SMS does not become less high because of a new factor, i.e. the rotating environment. Research system Jupiter 2 is a stand-alone slow-rotating ground facility for simulating motion sickness equivalent to its space form. The merits of this facility are the possibilities to control the intensity of exposure, perform long-term investigations of two active subjects simultaneously, and study the stages of body adaptation to this agent, and assess physical and operator's performance. The facility carries large expectations to occupational selection.

Interactions between megakaryocytes and sinus wall. An ultrastructural study on bone marrow tissue in primary (essential) thrombocythemia.

An ultrastructural study was performed on bone marrow tissue in primary (essential) thrombocythemia to evaluate possible interactions between megakaryocytes and sinusoids. In addition to a preferential localization of megakaryocytes in the subendothelial space, two different kinds of cytoplasmic processes could be discriminated penetrating the sinus wall. Serial sections disclosed that megakaryocytes developed multiple pseudopod-like plump projections derived from their peripheral zone and devoid of organelles. It is tempting to speculate that these ameboid features could serve as anchors to keep the cell in a subendothelial position and to monitor changes occurring in circulation. The second type of cytoplasmic processes reaching into the vascular lumen consisted of tentacle-like elongated protrusions rich in organelles, apparently originating from the intermediate zone. These projections were thought to present either the beginning of megakaryocytes egress into circulation or putative platelets. Frequently, there was an intrasinusoidal localization of megakaryocytes which revealed numerous so-called platelet territories and apparently an enforced platelet shedding. Generally, these features are comparable with aspects obtained from animal studies, following excessively stimulated megakaryo- and thrombocytopoiesis by application of anti-platelet serum.

[Human equilibrium under conditions of rotation with different levels of increased weightiness]. / Funktsiia ravnovesiia cheloveka v usloviiakh vrashcheniia pri razlichnykh urovniakh povyshennoi vesomosti.

This paper discusses the gravity (of up to 2 g) effect on the upright stability of 16 test subjects exposed either to centrifugation or to artificially increased body weight (with uniformly distributed loading). During centrifugation the stabilographic parameters increased significantly at every gravity level. In the experiments with artificially increased body weight the area of the vector stabilograms also increased significantly. The comparison of the two experimental runs suggests that disorders in the upright stability are caused by the rotation factor rather than by the artificially increased body weight.

[Effectiveness of the preparation Gavinton in preventing motion sickness]. / Effektivnost' preparata kavinton v profilaktike bolezni dvizheniia.

The effectiveness of the Hungarian drug kavinton used to prevent motion sickness was assessed. During the study 8 motion sickness susceptible test subjects were kept in a chamber rotating at a rate of 6 rpm for 5 hours. The effectiveness of the drug taken regularly during the exposure was compared with that of scopolamine and placebo taken as a single dose. The results obtained are suggestive of a positive effect of kavinton as an antimotion drug.

[Human tolerance to rotation at different levels of increased gravitation]. / Perenosimost' chelovekom vrashcheniia pri razlichnykh urovniakh povyshennoí vesomosti.

The effects of acceleration of different value (up to 2 g) on the level of motion sickness, vestibular and postural reactions to rotation were studied. The experiments were carried out in a centrifuge equipped with a cabin that could be mounted at a different distance from the axis of rotation. Three experimental runs were conducted with a rate of rotation of 15.3 and accelerations values of 1.09, 1.6 and 2.0 g. Vestibular stimulation was produced by head movements of a predetermined number. It was found that with increase in the acceleration value the level of motion sickness decreased and the nystagmic reaction and balance dysfunction enhanced.

Biomedical aspects of artificial gravity.

Artificial gravitv generated by spacecraft rotation may prove a universal countermeasure against adverse effects of weightlessness in the future. The paper summarizes the results of ground-based biomedical investigations of artificial gravity and flight experiments aboard Soviet biosatellites Cosmos-782 and Cosmos-936. It is believed that at the present stage the major goal of such investigations is to determine the minimum efficient value of artificial gravity in long-term flights which may eliminate adverse effects of prolonged weightlessness. In ground-bound studies the highest priority should be given to the development of methods on increasing human tolerance to the rotating environment.

[Effect of head-down tilt hypokinesia on human equilibrium function]. / Vliianie antiortostaticheskoi gipokinezii na funktsiiu ravnovesiia cheloveka.

Six test subjects who participated in 182-day head-down study at -4 degrees were examined stabilographically before and during the test. During the first 30 days they showed impaired equilibrium which later was relatively stabilized. Continuation of the bed rest study did not impair drastically stability of upright standing. It was shown that the contribution of optic sensors into the recovery of the equilibrium function increased during the second half of the bed rest study. Provocative tests suggest that bed rest related impairment of equilibrium occurs due to vestibular changes and deconditioning.

[Soviet research on artificial gravitational force]. / Otechestvennye issledovaniia po probleme iskusstvennoi sily tiazhesti.

The paper reviews biomedical investigations concerning artificial gravity performed so far in the USSR. It is believed that at the present stage the major task is to identify the minimum value of artificial gravity which may eliminate adverse effects of weightlessness on the human body. In ground-based investigations high priority should be given to the development of methods of increasing human tolerance to a rotating environment.

[Quantitative evaluation of the clinical manifestations of motion sickness]. / Kolichestvennaia otsenka klimicheskikh proiavlenii bolezni dvizheniia.

An original scheme of quantitative evaluation of clinical manifestations of motion sickness has been developed. According to the scheme, eight major symptoms of motion sickness: vertigo, nausea, vomiting, sweating, paleness, headache, sleepiness, flaccidity are scored in relation to their manifestations. The scheme has been used in vestibular tests of 57 test subjects. The vestibular test used is tolerance to cross-coupled acceleration. On the basis of the scores quantitative criteria of human tolerance to vestibular exposures have been suggested. It is emphasized that the scheme can be widely used allowing statistical treatment, comparative individual and group analysis of the data obtained.