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.     

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.     

Physiological changes in platelet aggregation and nitric oxide levels during menstrual cycle in healthy women.

Hormonal levels, mainly those of estrogens, protect women from the appearance of cardiovascular diseases by an increasing nitric oxide (NO) activity. NO is an endogenous vasodilator and antiaggregating substance. We decided to investigate platelet function and plasma levels of nitric oxide during preovulatory and midluteal phases in young and healthy women with normal menstrual cycles (MCs). Nine young, healthy female subjects had recorded three consecutive MCs before entering this program. Platelet-rich plasma (PRP) was used for the determination of platelet aggregation and NO measurements. Moreover, platelet sensitivity to the inhibitory effect of exogenous NO was tested. The EC(50) of collagen showed no differences between the preovulatory (1.36+/-0.16 microg/mL) and the midluteal (1.31+/-0.08 microg/mL; P, NS) phases. However, the EC(90) during the preovulatory phase was higher (2.05+/-0.2 microg/mL) than during the midluteal phase (1.8+/-0.6 microg/mL). Plasma levels of NO were lower during the preovulatory phase (19.1+/-2 microM) in comparison to the midluteal phase (20.9+/-2.3 microM). Interestingly, the exogenous amount of NO to produce at least half of the inhibition of an EC(90) collagen-induced aggregation was higher at the preovulatory phase (323.3+/-60.9 nM) than during the midluteal phase (240.0+/-37.5 nM; P, NS). We propose that during the follicular phase platelets rather use NO produced by the endothelium; therefore, it is necessary to add more agonist to activate those, but it results in higher consumption of circulating NO, whereas during luteal-phase platelets are not able to use NO, requiring lower amounts of agonist and thus resulting in higher plasma levels of NO. This is an interesting fact in research on cardiovascular diseases of women.     

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.