Role of modified CDC miniature light-traps as an alternative method for sampling adult anophelines (Diptera: Culicidae) in the National Mosquito Surveillance Programme in India

The efficiency of modified CDC miniature light-traps for sampling adult mosquitoes was evaluated in comparison with indoor resting, outdoor resting, indoor man-landing and outdoor man-landing collections in the hilly district of Koraput, Orissa, India. Overall, light-traps captured 78% of adult mosquitoes collected by all methods. Of the 16 anopheline species recorded in the study area, light-traps effectively sampled 13, contributing about 72% of the total anophelines collected by all methods. Light-traps also caught a large number of female Culex vishnui Theobald (96%). As fully-fed mosquitoes were predominant (82%) and caught alive, light-traps can be used to catch large numbers of vector mosquitoes for studies on vector prevalence, distribution, vector incrimination and also for laboratory bioassays. Light-trap and indoor resting collections revealed similar seasonal trends in numbers of Anopheles culicifacies Giles, A. fluviatilis James, A. jeyporiensis James, A. vagus Doenitz, and A. splendidus Koidzumi. Age-structure of the samples did not vary significantly between the two methods. Light-traps could be used as an alternative to daytime indoor resting collections to monitor the seasonal fluctuations in the abundance and parity rates of these species. The light-trap collections correlated with indoor and outdoor man-landing collections of A. jeyporiensis and the outdoor man-landing collections of A. maculatusTheobald in measuring seasonal trends. Light-trap collections can thus be used as a substitute for man-landing collections of A. jeyporiensis and A. maculatus.     

Comparison of sampling anopheline mosquitoes by light-trap and human-bait collections indoors at Bagamoyo, Tanzania

Abstract. The mosquito sampling efficiency of CDC miniature light-traps, relative to night-biting collections, was evaluated indoors at two sites in coastal Tanzania. We found that the total number of anophelines captured overnight by light-traps (hung beside a bednet in use) was 1.23 times the number of anophelines captured by human-bait collections. This relationship was not affected significantly by changes in the mosquito density, order of trapping method, date of sampling, or number of household occupants. Malaria sporozoite rates were twice as high among mosquitoes captured by light-trap as compared to those captured by night-biting collection. This was attributed to the tendency of light-traps to capture a larger proportion of gravid mosquitoes, which also had high sporozoite rates. The differences in sporozoites rates according to abdominal stage indicates that unfed mosquitoes captured by light-traps may define more precisely the human-biting activity and sporozoite rates as seen by night-biting collections. Our study shows that light-traps, when used in combination with night-biting collections, can be an effective and sensitive means for measuring human-biting activity and the sporozoite rate.     

Blood-feeding behaviour of the malarial mosquito Anopheles arabiensis: implications for vector control

Feeding behaviour of the malaria vector Anopheles arabiensis Patton (Diptera: Culicidae) was monitored for 12 months (March 2003-February 2004) in the Konso District of southern Ethiopia (5 degrees 15'N, 37 degrees 28'E). More than 45 000 An. arabiensis females were collected by host-baited sampling methods (light-traps, human landing catches, cattle-baited traps) and from resting sites (huts and pit shelters). In the village of Fuchucha, where the ratio of cattle : humans was 0.6 : 1, 51% of outdoor-resting mosquitoes and 66% of those collected indoors had fed on humans, human baits outdoors caught > 2.5 times more mosquitoes than those indoors and the mean catch of mosquitoes from pit shelters was about five times that from huts. Overall, the vast majority of feeding and resting occurred outdoors. In the cattle camps of Konso, where humans slept outdoors close to their cattle, approximately 46% of resting mosquitoes collected outdoors had fed on humans despite the high cattle : human ratio (17 : 1). In both places, relatively high proportions of bloodmeals were mixed cow + human: 22-25% at Fuchucha and 37% in the cattle camps. Anthropophily was also gauged experimentally by comparing the numbers of mosquitoes caught in odour-baited entry traps baited with either human or cattle odour. The human-baited trap caught about five times as many mosquitoes as the cattle-baited one. Notwithstanding the potential pitfalls of using standard sampling devices to analyse mosquito behaviour, the results suggest that the An. arabiensis population is inherently anthropophagic, but this is counterbalanced by exophagic and postprandial exophilic tendencies. Consequently, the population feeds sufficiently on humans to transmit malaria (sporozoite rates: 0.3% for Plasmodium falciparum and 0.5% for P. vivax, by detection of circumsporozoite antigen) but also takes a high proportion of meals from non-human hosts, with 59-91% of resting mosquitoes containing blood from cattle. Hence, classical zooprophylaxis is unlikely to have a significant impact on the malaria vectorial capacity of An. arabiensis in Konso, whereas treating cattle with insecticide might do.     

Does moonlight influence the biting behaviour of Anopheles funestus?

The possible effect of moonlight on the biting behaviour of mosquitoes in southern Mozambique, in particular that of Anopheles funestus (Diptera: Culicidae), a primary vector of malaria, was investigated by comparing catches indoors and outdoors using CDC light traps and 'Furvela' tent traps, respectively, for 35 consecutive nights, from 9 September to 15 October 2008. Collections were separated into three 4-hourly samples each night. A total of 17 591 mosquitoes belonging to nine species were collected, 6747 in light traps and 10 844 in tent traps. Anopheles funestus (n = 7634) and Mansonia africana (n = 4859) were the most abundant species. Fluctuations in temperature and humidity were the two environmental variables associated with changes in relative abundance of mosquitoes. Most An. funestus were collected indoors, with the majority collected in the first 4 h of the night. This was most evident on nights when moonlight was present in the early part of the night. A total of 3488 An. funestus were dissected for gonotrophic age determination. Parous rates did not change with lunar phase, but estimated oviposition cycle length was significantly shorter on nights when moonlight was present at the time of oviposition. Moonlight at dusk did not, however, affect the proportion of newly emerged insects with mating plugs collected. Outdoor transmission of malaria, especially on moonlit nights, remains a problem for control programmes.     

Developmental changes in the modulation of respiratory rhythm generation by extracellular K+ in the isolated bullfrog brainstem

This study tested the hypothesis that voltage-dependent, respiratory-related activity in vitro, inferred from changes in [K(+)](o), changes during development in the amphibian brainstem. Respiratory-related neural activity was recorded from cranial nerve roots in isolated brainstem-spinal cord preparations from 7 premetamorphic tadpoles and 10 adults. Changes in fictive gill/lung activity in tadpoles and buccal/lung activity in adults were examined during superfusion with artificial CSF (aCSF) with [K(+)](o) ranging from 1 to 12 mM (4 mM control). In tadpoles, both fictive gill burst frequency (f(gill)) and lung burst frequency (f(lung)) were significantly dependent upon [K(+)](o) (r(2) > 0.75; p < 0.001) from 1 to 10 mM K(+), and there was a strong correlation between f(gill) and f(lung) (r(2) = 0.65; p < 0.001). When [K(+)](o) was raised to 12 mM, there was a reversible abolition of fictive breathing. In adults, fictive buccal frequency (f(buccal)), was significantly dependent on [K(+)](o) (r(2) = 0.47; p < 0.001), but [K(+)](o) had no effect on f(lung) (p > 0.2), and there was no significant correlation between f(buccal) and f(lung). These data suggest that the neural networks driving gill and lung burst activity in tadpoles may be strongly voltage modulated. In adults, buccal activity, the proposed remnant of gill ventilation in adults, also appears to be voltage dependent, but is not correlated with lung burst activity. These results suggest that lung burst activity in amphibians may shift from a "voltage-dependent" state to a "voltage-independent" state during development. This is consistent with the hypothesis that the fundamental mechanisms generating respiratory rhythm in the amphibian brainstem change during development. We hypothesize that lung respiratory rhythm generation in amphibians undergoes a developmental change from a pacemaker to network-driven process.     

养分供应对3种舞花姜属植物繁殖方式的影响

该研究选用的3种舞花姜属植物中,毛舞花姜(Globba barthei)和双翅舞花姜(G. schomburgkii)自然条件下开花不结实,以珠芽进行繁殖;异果舞花姜(G. racemosa)则同时以种子和珠芽进行繁殖。在人工栽培条件下,高养分处理显著增加毛舞花姜的珠芽干重((1.11±0.10) g vs. (3.08±0.69) g,p=0.010 7)、珠芽数量((30.58±2.92) vs. (74.74±9.73),p=0.000 4)、珠芽大小((10.5±1.48) mg vs. (53.50±11.42) mg,p=0.001 5)、植株营养体重((3.99±0.23) g vs. (9.67±1.17) g,p=0.000 2)和双翅舞花姜的珠芽数量((51.74±3.64) vs. (108.71±21.52),p=0.018 1)。不同养分条件下两种舞花姜的开花数量无显著差异。人工去除珠芽、花对两种舞花姜植株当年生花和珠芽的数量无显著影响(p<0.05)。自然条件下异果舞花姜不同居群间珠芽大小、珠芽数、珠芽重、果实重、种子数和营养体重等均存在极显著差异(p<0.001)。异果舞花姜各居群植株珠芽数和营养体重(r=0.901,p<0.05)、珠芽重和珠芽大小 (r=0.849,p<0.05) 呈显著正相关;果实重和种子数(r=0.998,p<0.05) 呈显著正相关。土壤因子主成分分析表明前3个主成分提供的信息量分别为50.575%、18.204% 和11.883%,其中第一主成分中的全氮(0.959)、速效氮(0.885)和有机质(0.821)负荷量最大,第二主成分中土壤速效磷(0.824)负荷量最大。植株营养体重和土壤速效磷极显著正相关(r=0.906,p<0.01),珠芽大小与全氮(r=0.798)、速效氮(r=0.780)和有机质(r=0.821)均呈显著正相关(p<0.05)。果实重和种子数与土壤因子相关性不显著(p<0.05)。3种舞花姜的无性繁殖器官更易受到养分供应的影响,有性繁殖器官对养分供应变化响应不显著,有性和无性繁殖之间似不存在补偿关系。     

The impact of CO2 on collection of Aedes aegypti (Linnaeus) and Culex quinquefasciatus Say by BG-Sentinel(r) traps in Manaus,Brazil

Carbon dioxide (CO₂) is an important component for activating and attracting host-seeking mosquitoes. The BG-Sentinel^(r) trap is a well-established monitoring tool for capturing Culicidae, but CO₂ role for the trap effectiveness has not been evaluated in highly urbanised areas. The objective was to evaluate the effectiveness of BG-Sentinel traps baited with and without CO₂ for capturing urban mosquitoes. Fifteen areas were selected within the city of Manaus, Brazil, where four BG-Sentinels were operated for 24 h, two of them with CO₂ and two without CO₂. Captured Aedes aegypti females were dissected for the determination of their parity status. A significantly higher proportion of traps (from 32-79%) were positive for female Ae. aegypti when using the BG-Sentinel with CO₂ (χ² = 11.0271, p ≤ 0.001). Catches of female Culex spp were six times higher in CO₂ traps (Mann-Whitney U test = 190.5; p = 0.001). Parity rates were similar for both traps. This study showed that CO₂ has primarily an enhancing effect on the efficacy of BG-Sentinel for capturing Culex spp in Manaus. For Ae. aegypti, the positivity rate of the trap was increased, when CO₂ was added.     

Pteridine concentrations differ between insectary-reared and field-collected Anopheles albimanus mosquitoes of the same physiological age

Biopterin, isoxanthopterin and 6-pterincarboxylic acid were identified in the head of the malaria vector mosquito Anopheles albimanus Weidemann (Diptera: Culicidae) by HPLC. Total pteridine concentrations (TPC) were estimated in heads, body parts (BP: abdomen, legs and wings) and whole bodies of insectary-reared and field-collected females, by spectrofluorometry, to investigate whether they could be used for age determination. Pteridine concentrations diminished with age in both mosquito groups. TPC correlated with chronological age in insectary-reared sugar-fed females (heads: r2 = 0.35, BP: r2 = 0.34, P < 0.001), but lower correlation occurred in blood-fed females (heads: r2 = 0.22, BP: r2 = 0.27). TPC differed among females of the same age fed with blood at different times (P < 0.05), indicating that bloodmeals modify the diminution rate of pteridines with age. Nevertheless, a polynomial significant correlation was documented for TPC and the number of ovipositions (heads: r2 = 0.24, BP: r2 = 0.27, whole body: r2 = 0.52, P < 0.001) in insectary-reared mosquitoes. This correlation was lower in field-collected mosquitoes (heads: r2 = 0.14, BP: r2 = 0.10, P < 0.05), which showed a remarkable pteridine increase in one-parous females. The correlation of TPC in whole body with physiological age was much less (r2 = 0.03). These observations indicate that TPC determination by spectrofluorometry is not a reliable method to estimate the age of An. albimanus females from the feral population.     

Analysis of the cytochrome P450 1A1 (CYP1A1) gene polymorphism in the ethnic groups of the republic of Bashkortostan

In three ethnic groups from the Republic of Bashkortostan, Russians (N = 451), Tatars (N= 333), and Bashkirs (N = 171), allele, genotype, and haplotype frequency distribution patterns of the CYP1A1 gene single nucleotide polymorphisms, A2455G and T33801C, were investigated. Substantial interethnic differences in the allele frequency distribution patterns of the CYP1A1 polymorphisms A2455G and T3801C (χ ² = 15.61, d.f. = 2, P = 0.0001; and χ ² = 22.10, d.f. = 2, P = 0.0001, respectively) were observed. Pairwise comparison showed that ethnic groups of Tatars and Russians were similar in the A2455G allele frequencies (χ ² = 1.10, d.f. = 1, P = 0.30). However, in case of the T3801C marker, statistically significant differences were revealed (χ ² = 4.56, d.f. = 1, P = 0.032). At the same time, Bashkir ethnic group was found to be statistically significantly different from Russians and Tatars in the CYP1A1 polymorphic allele frequency distribution patterns (χ ² = 15.74, d.f. = 2, P = 0.0001; and χ ² = 7.47, d.f. = 1, P = 0.024, for A2455G, and χ ² = 6.46, d.f. = 1, P = 0.011; and χ ² = 21.36, d.f. = 1, P = 0.0001, for T3801C). Analysis of the CYP1A1 haplotype diversity showed that in terms of the CYP1A1 haplotype frequency distribution patterns, Bashkir ethnic group was statistically significantly different from both Russians (χ ² = 30.07, d.f. = 3, P = 0.0001) and Tatars (χ ² = 11.28, d.f. = 3, P = 0.013). The differences observed were caused by the high frequency of haplotype CYP1A1*2B, which was represented by a combination of rare alleles of the CYP1A1 polymorphisms A2455G and T3801C in Bashkirs (5.81%). On the other hand, the ethnic groups of Russians and Tatars residing in the Republic of Bashkortostan were characterized by similar frequencies of the CYP1A1 haplotypes (χ ² = 6.322, d.f. = 3, P = 0.127). The data obtained could be used in further investigations of the genetic bases of ecology dependant diseases and in the risk groups in the Republic of Bashkortostan.     

Hemolymph of Anopheles stephensi from noninfected and Plasmodium berghei-infected mosquitoes. 1. Collection procedure and physical characteristics.

Hemolymph was collected from adult female Anopheles stephensi by centrifugation of incised mosquitoes. Approximately 0.1 muliter was collected from each recently emerged mosquito, although smaller amounts were recovered with increasing age of the mosquito. Determinations were made of the pH, osmotic pressure, and specific gravity of this hemolymph at various times during the life of the adult mosquito. The values obtained were within the ranges found for other insects. Hemolymph collected from mosquitoes fed on hamsters infected with Plasmodium berghei had different values than hemolymph from mosquitoes fed on noninfected hamsters. This probably was due to differences between the quality of these 2 types of blood meals, rather than to the direct effects of the malaria parasite on the infected mosquito itself.     

Multiplex-PCR for detection of natural Leishmania infection in Lutzomyia spp. captured in an endemic region for cutaneous leishmaniasis in state of Sucre, Venezuela

We studied the natural infection of Lutzomyia (Lutzomyia) sp. with Leishmania in endemic foci of cutaneous leishmaniasis in the Paria peninsula, state of Sucre, Venezuela. Sand flies were collected between March 2001 and June 2003, using Shannon light-traps and human bait. Of the 1291 insects captured, only two species of phlebotomines were identified: L. ovallesi (82.75%) and L. gomezi (17.42%). A sample of the collected sand flies (51 pools of 2-12 individuals) were analyzed by using a multiplex-PCR assay for simultaneous detection of New Word Leishmaniaand Viannia subgenera. The results showed a total of 8 pools (15.68%) infected; of these, 7 were L. ovallesi naturally infected with L. braziliensis (2 pools) and L. mexicana (5 pools) and 1 pool of L. gomezi infected by L. braziliensis.     

A correlation between the cellular composition of the spleen and the change in splenocyte chemiluminescence after laser irradiation]

Chemiluminescence (CL) of splenocytes of A/Sn mice (1.5-9-month old) was recorded after irradiation of the cells with lambda semiconductor laser at 820 nm (dose 1.1 x 10(3) J/m2, pulse repetition rate 292 Hz). Laser radiation was found to stimulate or suppress the spontaneous CL (SCL) of splenocytes, the amplitude and its sign depending on cellular composition of the spleen. Direct correlations between effect of laser radiation (per cent in changes in SCL) and per cent of plasmatic cells (r = 0.743, p < 0.001), neutrophils (r = 0.650, p < 0.001) and myelocytes and metamyelocytes (r = 0.507, p < 0.01) were established. The correlation with per cent of lymphocytes (r = -0.590, p < 0.001) was found to be a reverse one.     

Fluxes of terrestrial and aquatic carbon by emergent mosquitoes: a test of controls and implications for cross-ecosystem linkages

Adult aquatic insects are a common resource for many terrestrial predators, often considered to subsidize terrestrial food webs. However, larval aquatic insects themselves consume both aquatic primary producers and allochthonous terrestrial detritus, suggesting that adults could provide aquatic subsidy and/or recycled terrestrial energy to terrestrial consumers. Understanding the source of carbon (aquatic vs. terrestrial) driving aquatic insect emergence is important for predicting magnitude of emergence and effects on recipient food web dynamics; yet direct experimental tests of factors determining source are lacking. Here, we use Culex mosquitoes in experimental pools as an exemplar to test how variation in general factors common to aquatic systems (terrestrial plant inputs and light) may alter the source and amount of energy exported to terrestrial ecosystems in adult aquatic insects that rely on terrestrial resources as larvae. We found strong sequential effects of terrestrial plant inputs and light on aquatic insect oviposition, diet, and emergence of Culex mosquitoes. Ovipositing mosquitoes laid ~3 times more egg masses in high terrestrial input pools under low light conditions. This behavior increased adult emergence from pools under low light conditions; however, high input pools (which had the highest mosquito densities) showed low emergence rates due to density-dependent mortality. Mosquito diets consisted mainly of terrestrial resources (~70–90 %). As a result, the amount of aquatic carbon exported from pools by mosquitoes during the experiment was ~18 times higher from low versus high light pools, while exports of terrestrial carbon peaked from pools receiving intermediate levels of inputs (3–6 times higher) and low light (~6 times higher). Our results suggest that understanding the interplay among terrestrial plant inputs, light availability and biotic responses of aquatic insects may be key in predicting source and magnitude of emergence, and thus the strength and effects of aquatic–terrestrial linkages in freshwater systems.     

Effect of thinning on flying insect communities using window traps in young douglas-fir (<Emphasis Type="Italic">Pseudotsuga menziesii</Emphasis> (Mirb.) Franco) forests in the Pacific Northwestern America

The response of insects to four thinning intensities (control, light-thin, heavy-thin, or light-thin with gaps) was examined in 40-to 60-year-old Douglas-fir stands on the Willamette National Forest in Oregon, USA. In both 2000 and 2001, flying insect assemblages were collected from window traps placed over the forest floor in the center of each treatment block during two annual intervals: 1 ) June through August (early-season) and 2) August through October (late-season). The seasonal responses by these insects showed statistically significant differences in species richness (F= 22.21,P <0.001) and mean abundance (F=34.87,P <0.001). The greatest numbers of taxa generated via indicator species analysis were in the early season and within the treatment of light-thin with gap (L./ G). In particular, the woodborer beetle,Buprestis (Burprestidae), was strongly associated with L/G (Indicator Value = 52.4, P ≤0.001 ). Two beetle taxa,Ampedus (Elateridae, IV=84.7, P ≤0.001 ) and members of Cermabycidae (IV=58.4, P ≤0.001 ), were correlated significantly with early-season, whereasMelanoplus (Acrididae) was associated with late-season (IV=21.3, P >0.05) and L/G (IV=29.2, P ≤0.05). For all thinning treatments, the numbers of species and individuals were higher in the early season than the late season. Non-metric multidimensional scaling showed that Axis 1 (65%) and Axis 2 (27%) explained 92% of the variance. The former was strongly associated with thinning intensity, having higher coefficients of species richness (r=0.645) and species diversity (r=0.583). The multi-response permutation procedures showed a statistically significant difference for thinning intensity (T-statistics=-4.6322,A-statistics=0.0479,P <0.0001 ). These results suggest that heavier thinning can result in more diverse populations of flying insects, including herbivores and predators.     

Adverse ffects of covert iridovirus infection on life history and demographic parameters of Aedes aegypti

Abstract Sublethal viral infections can cause changes in the body size and demography of insect vectors, with important consequences for population dynamics and the probability that individual mosquitoes will transmit disease. This study examined the effects of covert (sublethal) infection by Invertebrate iridescent virus 6 (IIV‐6) on the demography of female Aedes aegypti and the relationship between key life history parameters in covertly infected female insects compared with healthy (control) insects or non‐infected mosquitoes that had survived exposure to virus inoculum without becoming infected. Of the female mosquitoes that emerged following exposure to virus inoculum and were offered blood meals, 29% (43/150) proved positive for covert IIV‐6 infection. The net reproductive rate (R₀) of covertly infected females was 50% lower for infected females compared to control mosquitoes, whereas non‐infected exposed females had an R₀ approximately 15% lower than that of controls. Reproduction caused a significant decrease of about 13 days in mosquito longevity compared to females that did not reproduce (P < 0.001). Infected females lived 5–8 days less than non‐infected exposed females or controls, respectively (P = 0.028). Infected females and non‐infected exposed females both had significantly shorter wings than control insects (P < 0.001). There was a significant positive correlation between wing length and longevity in covertly infected female mosquitoes but not in control or non‐infected exposed mosquitoes. Longer lived females produced more eggs in all treatments. There were no significant correlations between body size and fecundity or the production of offspring. There was also no correlation between fecundity and fertility, suggesting that sperm inactivation was a more likely cause of decreased fertility in older mosquitoes than sperm depletion. We conclude that covert infection by iridescent virus is likely to reduce the vectorial capacity of this mosquito.     

Colonisation by native species of abandoned farmland adjacent to a remnant patch of Mediterranean steppe

We studied plant distribution at the margins (0–10 m) of three formerly cultivated plots adjacent to a remnant patch of the only Mediterranean steppe of France: La Crau. We sampled above-ground vegetation, seed bank, seed rain and seed dispersal by ants in order to assess the colonisation of steppe species at margins. Our results showed that (1) present day above-ground vegetation of formerly cultivated plots is influenced more by former agricultural practices (duration of melon cultivation, fertilisation) and time since abandonment than their position in relation to the steppe. (2) An edge effect was identified as the vegetation of the steppe (e.g. Thymus vulgaris, Salvia verbenaca, Linaria arvensis) colonises the formerly cultivated plots (coefficients of similarity between vegetation on margins and steppe vegetation decreased with distance from boundaries (r = -0.65, p < 0.001)). (3) Permanent deep seed bank (10-20 cm) did not contribute to either site or edge effects and was characterised by weed species from previous melon cultivation (e.g. Chenopodium album, Kicksia elatine, Portulaca oleracea, Solanum nigrum). (4) Seed rain density decreased with distance from edges (r = -0.39, p < 0.001) and seemed positively correlated to T. vulgaris cover. (5) The number of seeds in ant-traps seemed correlated to T. vulgaris cover. We concluded that after 19 years of abandonment, only about half of the steppe species have colonised just the few meters of the margins of the formerly cultivated plots and that restoration from seed bank, seed rain or seed dispersal by ants is unlikely. Our results are thus discussed within the context of restoring the steppe plant community on formerly cultivated plots.

     

Mini-review of the concentration variations found inthe alfresco atmospheric bacterial populations

Variations in the atmospheric surface layer's culturable, and to a lesser extent, total bacteria-associated atmospheric particlecharacteristics will be discussed in terms of (a)their temporal variation from 2 min resolutionthrough diurnal to annual periods, (b) the effect ofmeteorological conditions on their abundance andsize, (c) total to culturable bacterial ratio, and(d) the total number of bacteria per culturableparticle (e) bacterial survival in droplet/particles, and (f) the general particle size distribution including aerodynamic Count MedianDiameter (CMD).Meteorological and topographic conditions thatcontrol total and culturable bacteria-associatedatmospheric particle concentration will be presentedin terms of (a) precipitation, (b) wind direction,(c) time of day, (d) sky conditions (i.e., cloudy,sunny, rain, etc.), (e) season, and (f) atmosphericinversion conditions.Simulation models will be described that supporthypotheses of diurnal and annual concentrationcycles in the Earth's (and perhaps other planetaryatmospheres) atmospheric surface layer.     

Some ambient environmental conditions, food and reproductive habits of the banded lampeye killifish Aplocheilichthys spilauchen in the Kakum estuary wetland, Ghana

The use of killifish in biological control of mosquitoes to complement other mosquito control programs is gaining interest due to the increasing development of chemically resistant substrains of mosquitoes. This study investigates the ambient salinity, temperature and dissolved oxygen as well as food habits, sex ratio, fecundity and spawning frequency of Aplocheilichthys spilauchen in Ghana in an effort to broaden knowledge of the suitability of this killifish for mosquito control. Sampling was undertaken from July 2009 to January 2010 to monitor the levels and variations in the environmental parameters and fish abundance, and also to determine the feeding ecology, fecundity and possible spawning frequency. Results suggested that lower levels of salinity favoured the population while levels beyond 4‰ were detrimental. The species preyed highly on insects and insect larvae, which constituted 80% of food consumed. Females significantly outnumbered males by almost 2:1 (χ²?=?28.57, P?<?0.05), and had low fecundity (2–44 eggs). Ova diameter analysis suggested that the species spawns continuously. The better survivability of the species in freshwater pools with continuous spawning of drought tolerant eggs, and the high preference for insects and insect larvae suggest that it could be a useful candidate for biocontrol of mosquitoes.     

Generalist bees (Meliponina) and the reproductive success of the mass flowering tree Stryphnodendron pulcherrimum (Fabales: Mimosaceae) in the Atlantic Rainforest, Bahia

It is controversial the role played by Meliponina bees in the pollination of mass flowering trees with small generalized flowers (FMPG), very common group of trees in the tropical forest canopy. The species richness and relative abundance of flower visiting insects of the mass flowering tree Stryphnodendron pulcherrimum were measured to test the hypothesis of tight ecological association between these generalist bees and FMPG and to evaluate the effect of this relationship upon the reproductive success variation among tree crowns. The flower visiting insects were sampled on 10 flowering tree crowns at the Atlantic Rainforest in southern Bahia. Altogether, 553 visiting insects were collected during the flowering period of S. pulcherrimum: 293 (52%) Meliponina bees out of 438 bees (79.4%). All tree crowns were visited by Meliponina, with the proportion of these bees ranging from 27% to 87%. The tight ecological association between FMPG trees and Meliponina bees is supported by the observed pattern of spatial relationship. Both the relationship between variation of fruit set among tree crowns and species richness (r = 0.3579; P = 0.3098) or relative abundance (r = 0.3070; P = 0.3881) of Meliponina were not statistically significant. Likely a threshold of minimum relative abundance combined with the absolute abundance of these bees explain the fruit set variation among tree crowns of S. pulcherrimum, even by self-pollination. We tested this assumption with a preliminary analysis of Melipona bee genera distribution among the tree crowns.     

Age-related decline in handgrip strength differs according to gender

It is well-established that at old age there is a significant decline in muscle strength. Reference values for muscle strength might be useful for assessment of muscle impairment and of physiological adaptations. However, it is still unclear whether gender affects the rate of decline. Therefore, the aim of this study is to investigate the effect of gender and age on handgrip strength and to establish reference values for this variable. Reviewing medical charts collected from 1994 to 2005, a convenience sample of 2,648 subjects (1,787 men and 861 women), aged between 18 and 90 years, was obtained. Our results show higher handgrip strength for men compared with women (36.8 +/- 0.20 vs. 21.0 +/- 0.18 kg; p < 0.001). The regression analysis with a quadratic model shows that aging accounts for 30% of the variance in handgrip strength (r(2) = 0.30; p < 0.001) in men and 28% (r(2) = 0.28; p < 0.001) in women. In addition, the bent linear regression with multiple regressors show that a faster decline in handgrip strength occurs at the age of 30 years for men and 50 years for women. We conclude that handgrip strength decline with age differs between genders, making useful the existence of distinct male and female normative age group data.