The Diversity of Flower Flies (Diptera: Syrphidae) in Colombia and Their Neotropical Distribution

In Colombia, like most Neotropical countries, faunistic studies on flower flies have been occasional and most of them have been primarily focused on taxonomy. Colombia is the second-most species-rich country in flower fly diversity in the Neotropics after Brazil, and has one of the highest numbers of species per unit area (2.49 per 10,000?km²), based on a review of literature and national collections. Including new data presented here, a total of 47 genera and 300 species are recorded in Colombia. The genera Scaeva Fabricius and Lycastrirhyncha Bigot, as well as 101 species are recorded here for the first time. The altitudinal range and the distribution of the flower fly genera in Colombia are presented. A preliminary comparison of the fauna of Colombia with that of other Neotropical countries is given. A historical perspective is also provided in order to illustrate how Colombian Syrphidae knowledge has progressed over the last 168?years. Information presented here will be useful for ongoing and future biodiversity research as well as conservation projects on Syrphidae in the Neotropical region.     

Hunting and Gathering in Tropical Rain Forest: Is It Possible?

Hunters and gatherers living in tropical forests represent an important part of the total range of variation among contemporary hunting and gathering societies. Studies of tropical forest hunting and gathering peoples have contributed to our perceptions of the foraging way of life. Yet no peoples have ever been directly observed living independently of agriculture in tropical rain forest. This article tests the hypothesis that humans do not exist nor have ever existed independently of agriculture in tropical rain forest. We find no convincing ethnographic evidence and, with the possible exception of Malaysia, no archeological evidence for pure foragers in undisturbed tropical rain forests. Negative evidence cannot be conclusive, but it suggests that we need to carefully reexamine common assumptions concerning the recent history of tropical forest dwellers, the adaptability of preagricultural humans, the geographic and environmental range of hominids, and the form and consequences of selection pressures acting on humans in warm, humid environments. The overriding purpose of this article is to stimulate further ecological and archeological research in the neglected tropical forest areas of the world.     

Behavioral and Physiological Analyses of Ultrasound Production by Female Hamsters (Mesocricetus auratus)

The results of behavioral studies suggest specific roles forhigh-frequency vocalizations (ultrasounds) in courtship andcopulatory interactions among golden hamsters. In addition,these results, and functional interpretations based on them,can help to guide studies of physiological mechanisms controllingultrasonic communication. For example, interpretations of rodentultrasounds as sexual or agonistic signals suggest that ultrasoundrates depend on gonadal hormones. This prediction has been verifiedfor several rodent species, including hamsters. Similar reasoningshould apply to the analysis of brain mechanisms for ultrasoundproduction. In particular, the consideration of hamster ultrasoundsas sexual behaviors and vocalizations, as well as hormone-dependentresponses, suggests several brain areas as especially likelyparticipants in neural circuits mediating hormonal effects onultrasonic communication. The preliminary results of a studyin which we lesioned one of these areas, the mesencephalic centralgrey, confirm this structure's involvement in the control ofhamster ultrasounds, and, more generally, support the utilityof behavioral data in physiological studies.     

Using temperature‐dependent changes in leaf scaling relationships to quantitatively account for thermal acclimation of respiration in a coupled global climate–vegetation model

The response of plant respiration (R) to temperature is an important component of the biosphere's response to climate change. At present, most global models assume that R increases exponentially with temperature and does not thermally acclimate. Although we now know that acclimation does occur, quantitative incorporation of acclimation into models has been lacking. Using a dataset for 19 species grown at four temperatures (7, 14, 21, and 28 °C), we have assessed whether sustained differences in growth temperature systematically alter the slope and/or intercepts of the generalized log–log plots of leaf R vs. leaf mass per unit leaf area (LMA) and vs. leaf nitrogen (N) concentration. The extent to which variations in growth temperature account for the scatter observed in log–log R–LMA–N scaling relationships was also assessed. We show that thermal history accounts for up to 20% of the scatter in scaling relationships used to predict R, with the impact of thermal history on R–LMA–N generalized scaling relationships being highly predictable. This finding enabled us to quantitatively incorporate acclimation of R into a coupled global climate–vegetation model. We show that accounting for acclimation of R has negligible impact on predicted annual rates of global R, net primary productivity (NPP) or future atmospheric CO₂ concentrations. However, our analysis suggests that accounting for acclimation is important when considering carbon fluxes among thermally contrasting biomes (e.g. accounting for acclimation decreases predicted rates of R by up to 20% in high‐temperature biomes). We conclude that acclimation of R needs to be accounted for when predicting potential responses of terrestrial carbon exchange to climatic change at a regional level.     

Impact of transgenic Bt-cotton on the diversity of pink-pigmented facultative methylotrophs

Pink-pigmented facultative methylotrophs (PPFMs) are one of the beneficial proteobacteria commonly found in phyllosphere, rhizosphere and as endophytes in cotton. To assess the impact of transgenic Bt-cotton on changes in the diversity and community profile of PPFMs by comparing with its non-transgenic cotton, a polyphasic approach including differential carbon-substrate utilization profiling and DNA fingerprinting techniques like ARDRA, RISA, BOX-PCR and ERIC-PCR were studied. PPFMs from phyllosphere, rhizoplane and internal tissues of the stem of both Bt-cotton and non-Bt-cotton were isolated and analysed in this study. All the results suggested that the diversity richness of PPFMs present in the phyllosphere, rhizoplane and internal tissues did not differ between Bt- and non-Bt-cotton. In this study, there was no evidence to indicate any adverse effects of Bt-cotton on the diversity of plant-associated methylobacteria.     

SPICULES IN SILURIAN TABULATE CORALS FROM CANADA, AND IMPLICATIONS FOR THEIR AFFINITIES

Abstract:  Specimens of Favosites from upper Llandovery strata of Anticosti Island show three types of calcite structures, herein interpreted as spicules, preserved within their calices and on top of the last tabula. This is stratigraphically younger material, some 50 m higher than fossils described two decades earlier, in which calcified polyps, each with 12 retracted tentacles, were noted. These more recently found structures show striking similarities in form and position to point, collaret and capstan spicules found in the soft tissues of modern pipe corals, i.e. the Octocorallia (Alcyonacea). Where preserved in a distinct pattern on top of the calcite tabulae, the spicular sclerites in Favosites occur in a particular sequence. Twelve individual, or sometimes six pairs of, triradiate point spicules have shrunk to a circlet near the middle of the calice (resting on the last, outermost, tabula). Surrounding the point spicules are 3–6 circlets of curved, usually perforated, lenticular collaret spicules; and surrounding these are scattered, much smaller, capstan spicules. The spicules display variability, probably ontogenetic, in their form and relative sizes; and they are more similar in form to calcareous spicules of alcyonacean corals than to those known from calcareous sponges. Structures with 12-fold radial symmetry in Heliolites, originally described by one of us as 'septal florets', consist of elements that are considered comparable with the point spicules found in Favosites . They have been recognized in ten species of Heliolites from Silurian (Wenlock–Ludlow) strata in the Canadian Arctic islands.     

Effects of US 1 Project on Florida Key Deer Mortality

ABSTRACT Approximately 26% of annual mortality for the endangered Florida Key deer (Odocoileus virginianus clavium) occurs as deer-vehicle collisions (DVCs) on the 5.6-km section of United States Highway 1 (US 1) on Big Pine Key (BPK), but extensive urban development adjacent to sections of US 1 complicates efforts to reduce DVCs. Our objective was to evaluate the effectiveness of the US 1 Project (continuous 2.6-km system of 2.4-m fencing, 2 underpasses, and 4 experimental deer guards constructed on US 1 on BPK) in reducing DVCs along US 1. Deer used the underpasses all 3 postproject years (2003–2005); however, we observed higher underpass use in 2004 and 2005 compared to 2003. Exclusion fencing reduced deer intrusions onto the fenced section of US 1 during the 3-year period (2003, n = 7 deer; 2004, n = 4; 2005, n = 12). With a reduction of deer intrusions onto this section of US 1, DVCs decreased in the fenced area by 73–100%; however, US 1 DVCs within the unfenced sections of US 1 also increased (40%) as expected. In controlling for effects of increasing deer density and traffic volume, study results suggest that highway improvements have decreased the net risk of DVCs along US 1, which indicates that use of deer fencing, deer guards, and underpasses is applicable in other urban communities experiencing unacceptable levels of DVCs.     

Tolerability and efficacy of single dose albendazole,diethylcarbamazine citrate (DEC) or co-administration of albendazole with DEC in the clearance of <Emphasis Type="Italic">Wuchereria bancrofti</Emphasis>in asymptomatic microfilaraemic volunteers in Pondicherry,South India: a hospital-based study

Background  

The tolerability and efficacy of single dose albendazole (400 mg), diethylcarbamazine citrate (DEC) (6 mg/kg bodyweight) or co-administration of albendazole (400 mg) + DEC (6 mg/kg bodyweight) was studied in 54 asymptomatic Wuchereria bancrofti microfilaraemic volunteers in a double blind hospital-based clinical study.