Cicada acoustic communication: potential sound partitioning in a multispecies community from Mexico (Hemiptera: Cicadomorpha: Cicadidae)

Multispecies cicada communities in neotropical rainforests produce a complex and intense acoustic environment. In a fragment of a Mexican rainforest (Veracruz, Mexico), a cicada community at the end of the dry season consisted of nine species ( Daza montezuma; Pacarina schumanni; Miranha imbellis; Dorisiana sutori; Fidicinoides picea; Fidicinoides pronoe; Quesada gigas; one species of the genus Neocicada and one uncaught canopy species). Seven of the nine species formed dense choruses at dawn and at dusk. Each species showed preferences in the height of calling sites. Males of the species were solitary or gregarious, and followed a 'call-fly' or a 'call-stay' calling strategy. Acoustic signals of each species had particular time and frequency patterns. All these specific features appear to separate the nine species acoustically and lead to a partitioning of the acoustic environment. The acoustic partitioning might decrease the risk of heterospecific courting and mating.© 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 75 , 379–394.     

Two-dimensional 1H NMR study of human ubiquitin: a main chain directed assignment and structure analysis

The 1H resonances of human ubiquitin were studied by two-dimensional nuclear magnetic resonance techniques. A recently introduced assignment algorithm termed the main chain directed (MCD) assignment [Englander, S. W., & Wand, A. J. (1987) Biochemistry 26, 5953-5958] was applied. This approach relies on an ordered series of searches for prescribed patterns of connectivities in two-dimensional J-correlated and nuclear Overhauser effect spectra and centers on the dipolar interactions involving main-chain amide NH, alpha-CH, and beta-CH. Unlike the sequential assignment procedure, the MCD approach does not rest upon definition of side-chain J-coupled networks and is generally not sequential with the primary sequence of the protein. The various MCD patterns and the general algorithm are reiterated and applied to the analysis of human ubiquitin. With this algorithm, the vast majority of amino acid residue amide NH-C alpha H-C beta H J-coupled subspin systems could be associated with and aligned within units of secondary structure without any knowledge of the identity of the side chains. This greatly simplified recognition of side-chain spin systems by restricting their identity. Essentially complete resonance assignments are presented. The MCD method is compared with the sequential assignment method in some detail. The MCD method is highly amenable to automation. Human ubiquitin is found, at pH 5.8 and 30 degrees C, to be composed of an extensive beta-sheet structure involving five strands. Three of these strands form an antiparallel set sharing a common strand and have a parallel orientation to two antiparallel strands. Two helical segments were also observed. The largest, spanning 13 residues, shows dipolar interactions consistent with an alpha-helix while the smaller 4-residue helical segment appears, on the basis of observed nuclear Overhauser effects, to be a 3(10) helix. Five classical tight turns could be demonstrated.     

Scabies and Impetigo Prevalence and Risk Factors in Fiji: A National Survey

BackgroundScabies is recognised as a major public health problem in many countries, and is responsible for significant morbidity due to secondary bacterial infection of the skin causing impetigo, abscesses and cellulitis, that can in turn lead to serious systemic complications such as septicaemia, kidney disease and, potentially, rheumatic heart disease. Despite the apparent burden of disease in many countries, there have been few large-scale surveys of scabies prevalence or risk factors. We undertook a population-based survey in Fiji of scabies and impetigo to evaluate the magnitude of the problem and inform public health strategies.ConclusionsAs far as we are aware, this is the first national survey of scabies and impetigo ever conducted. We found that scabies occurs at high levels across all age groups, ethnicities, and geographical locations. Improved strategies are urgently needed to achieve control of scabies and its complications in endemic communities.     

Comparative studies of glutathione reductase and lipoamide dehydrogenase

1. Glutathione reductase and lipoamide dehydrogenase are structurally and mechanistically related flavoenzymes catalyzing various one and two electron transfer reactions between NAD(P)H and substrates with different structures. 2. The two enzymes differ in their coenzyme and functional specificities. Lipoamide dehydrogenase shows higher coenzyme preference while glutathione reductase displays greater functional specificity. 3. Binding preference of the two flavoenzymes for nicotinamide coenzymes is demonstrated by 31P-NMR spectroscopy. 4. The presence of arginines in glutathione reductase which is inactivated by phenyl glyoxal, is likely to be responsible for the NADPH-activity of glutathione reductase. 5. The substrate binding sites of the two enzymes are similar, though their functional details differ. 6. The active-site histidine of glutathione reductase functions primarily as the proton donor during catalysis. While the active-site histidine of lipoamide dehydrogenase stabilizes the thiolate anion intermediate and relays a proton in the catalytic process.     

Food provision to nestlings in the Hoopoe Upupa epops: implications for the conservation of a small endangered population in the Swiss Alps

In an attempt to recognize the possible ecological causes of the decline of a population of Hoopoes Upupa epops in the Swiss Alps, we collected data on resource exploitation. The prey provisioned to nestlings by parents was investigated at four breeding sites using photographs (n = 4353, 80% of which enabled prey identification). Molecrickets Gryllotalpa gryllotalpa and Lepidoptera (larvae and pupae) were dominant in nestling diet (93% frequency; 97% biomass). Although Molecrickets were provisioned less frequently (26%) than Lepidoptera (67%), they represented 68% of the total biomass (vs 29% for Lepidoptera). There was an overall negative relationship between the proportion of Molecricket biomass in the diet and the parents' feeding rate, whereas a comparison between broods showed that a higher provisioning activity did not lead to an increase in the biomass supplied to the chicks. A diet based on Molecrickets therefore appears to be energetically advantageous. As Molecrickets are a traditional prey of Hoopoes in central Europe, this might be relevant to other populations. In the study area, Molecrickets occur only on the intensively cultivated plain, whereas the majority of Hoopoe pairs nest at various altitudes on the foothills adjacent to the plain as the latter provides at present almost no suitable nesting sites. Hoopoes breeding higher up on the foothills seem to experience greater provisioning costs and have, on average, lower breeding success. Providing nest sites on the plain is the main conservation measure proposed for the local Hoopoe population. Further attention should also be paid to Molecrickets as these may be crucial for Hoopoes.     

Cyclic Expression of A Nuclear Protein In A Dinoflagellate

Nuclei of the dinoflagellate Crypthecodinium cohnii strain Whd were isolated and nuclear proteins were extracted in three fractions, corresponding to the increasing affinity of these proteins to genomic DNA. One fraction contained two major bands (48- and 46-kDa) and antibodies specific to this fraction revealed two major bands by Western blot on nuclear extracts, corresponding to the 46- and 48-kDa bands. The 48-kDa protein was detected in G1 phase but not in M phase cells. An expression cDNA library of C. cohnii was screened with these antibodies, and two different open reading frames were isolated. Dinoflagellate nuclear associated protein (Dinap1), one of these coding sequences, was produced in E. coli and appeared to correspond to the 48-kDa nuclear protein. No homologue of this sequence was found in the data bases, but two regions were identified, one including two putative zinc finger repeats, and one coding for two potential W/W domains. The second coding sequence showed a low similarity to non-specific sterol carrier proteins. Immunocytolocalization with specific polyclonal antibodies to recombinant Dinap1 showed that the nucleus was immunoreactive only during the G1 phase: the nucleoplasm was immunostained, while chromosome cores and nuclear envelopes were negative.     

Large-scale identification of polymorphic microsatellites using an <Emphasis Type="Italic">in silico</Emphasis> approach

Background  

Simple Sequence Repeat (SSR) or microsatellite markers are valuable for genetic research. Experimental methods to develop SSR markers are laborious, time consuming and expensive. In silico approaches have become a practicable and relatively inexpensive alternative during the last decade, although testing putative SSR markers still is time consuming and expensive. In many species only a relatively small percentage of SSR markers turn out to be polymorphic. This is particularly true for markers derived from expressed sequence tags (ESTs). In EST databases a large redundancy of sequences is present, which may contain information on length-polymorphisms in the SSR they contain, and whether they have been derived from heterozygotes or from different genotypes. Up to now, although a number of programs have been developed to identify SSRs in EST sequences, no software can detect putatively polymorphic SSRs.