46,418 research outputs found
Seven Species of Michigan Butterflies Attracted to Fluorescent Light
Excerpt: Many lepidopterists agree that if mechanically disturbed, butterflies may be attracted to fluorescent light. Yet the entire problem of the attraction of day-flying Lepidoptera to light i s still in the data-collecting stage, and records indicate that mechanical disturbance may not always be a determining factor. Numerous papers on the problem have appeared in recent years, especially in the J.Lepid. Soc., which may be consulted for bibliographical details not attempted in this collection note
Behavioural and insecticidal effects of organophosphate-, carbamate- and pyrethroid-treated mosquito nets against African malaria vectors.
Three insecticides - the pyrethroid deltamethrin, the carbamate carbosulfan and the organophosphate chlorpyrifos-methyl - were tested on mosquito nets in experimental huts to determine their potential for introduction as malaria control measures. Their behavioural effects and efficacy were examined in Anopheles gambiae Giles s.s. (Diptera: Culicidae) and Anopheles funestus Giles s.s. in Muheza, Tanzania, and in Anopheles arabiensis Patton and Culex quinquefasciatus Say in Moshi, Tanzania. A standardized dosage of 25 mg/m(2) plus high dosages of carbosulfan (50 mg/m(2), 100 mg/m(2) and 200 mg/m(2)) and chlorpyrifos-methyl (100 mg/m(2)) were used to compare the three types of insecticide. At 25 mg/m(2), the rank order of the insecticides for insecticide-induced mortality in wild An. gambiae and An. funestus was, respectively, carbosulfan (88%, 86%) > deltamethrin (79%, 78%) > chlorpyrifos-methyl (35%, 53%). The rank order of the insecticides for blood-feeding inhibition (reduction in the number of blood-fed mosquitoes compared with control) in wild An. gambiae and An. funestus was deltamethrin > chlorpyrifos-methyl > carbosulfan. Carbosulfan was particularly toxic to endophilic anophelines at 200 mg/m(2), killing 100% of An. gambiae and 98% of An. funestus that entered the huts. It was less effective against the more exophilic An. arabiensis (67% mortality) and carbamate-resistant Cx quinquefasciatus (36% mortality). Carbosulfan deterred anophelines from entering huts, but did not deter carbamate-resistant Cx quinquefasciatus. Deltamethrin reduced the proportion of insects engaged in blood-feeding, probably as a consequence of contact irritancy, whereas carbosulfan seemed to provide personal protection through deterred entry or perhaps a spatial repellent action. Any deployment of carbosulfan as an individual treatment on nets should be carried out on a large scale to reduce the risk of diverting mosquitoes to unprotected individuals. Chlorpyrifos-methyl was inferior to deltamethrin in terms of mortality and blood-feeding inhibition and would be better deployed on a net in combination with a pyrethroid to control insecticide-resistant mosquitoes
Some Notes on Heteropteran Trichobothria
Excerpt: There has been much recent interest in the comparative morphology of the Heteroptera. This work has emphasized the land bugs, or Geocorisae, and has been concerned with working out the relationships and taxonomic placement of the higher categories (categories above the genus), and with the phylogenetic lines and sequences of these higher categories. The geocorisine groups with which I have been most concerned are in the closely related superfamilies Lygaeoidea, Pyrrho- coroidea, and Coreoidea (see Schaefer, 1964, for a discussion of the relationships among these groups). Another superfamily, the Pentatomoidea, is less closely related. All four of these superfamilies have arolia and pseudarolia, and all four have trichobothria. Because they possess this last character in common, the four are grouped together under the name Heteroptera Trichophora (Tullgren, 1918), aname of no nomenclatorial standing but nevertheless convenient.
Trichobothria are long hairs arising from often darkened sockets on the relatively bald abdominal venter. They are usually easy to distinguish from other hairs, because they are longer, have a darkened base, and are arranged symmetrically in a distinctive pattern on each segment.
These patterns and the number of trichobothria in them are characteristic of the higher categories of the Trichophora. Since the trichophoran families are closely related, and since this close relation- ship has been established on evidence from other morphological features than trichobothria, one might look for phylogenetic significance in the variety of patterns. However, very little is known about the function and phylogenetic origin of trichobothria. I shall speculate here on their function and their phylogenetic significance, but more must be learned about trichobothria before speculation becomes knowledge
LISA For Cosmologists: Calculating The Signal-To-Noise Ratio For Stochastic And Deterministic Sources
We present the steps to forecast the sensitivity of the Laser Interferometer Space Antenna (LISA) to both a stochastic gravitational wave background and deterministic wave sources. We show how to use these expressions to estimate the precision with which LISA can determine parameters associated with these sources. Tools are included to enable easy calculation of the signal-to-noise ratio and draw sensitivity curves. Benchmark values are given for easy comparison and checking of methods in the case of three worked examples. The first benchmark is the threshold stochastic gravitational wave background ΩGWh2 that LISA can observe. The second is the signal-to-noise ratio that LISA would observe for a binary black hole system identical to GW150914, radiating four years before merger. The third is the case of a monotone source, such as a binary that is far from merger
Mutations in dhfr in Plasmodium falciparum infections selected by chlorproguanil-dapsone treatment.
Treatment with the novel antifolate drug combination chlorproguanil-dapsone effectively cleared asymptomatic Plasmodium falciparum infections in 246 (93.5%) of 263 children in the Usambara Mountains of Tanzania during the course of a 2-week follow-up. Samples from 71 recurrent infections, collected over a 9-week follow-up, showed selection for parasites with the triple mutant Ile(51)-Arg(59)-Asn(108) in dihydrofolate reductase. There was no selection for mutations in dihydropteroate synthetase, the target enzyme of dapsone. Search for complete identity in the highly polymorphic genes coding for merozoite surface proteins 1 and 2 in parasite samples collected before and after treatment indicated that the majority of recurrent parasitemias were new infections. These observations on selection in Tanzania and the lack of selection reported from a less endemic area suggest that the active metabolite of chlorproguanil, which has a short half-life in the blood, may persist in the liver, where it exerts selective pressure on growing preerythrocytic stages
A catalogue of West Indies Anthribidae (Coleoptera)
This is a catalogue of 23 described and 6 undescribed genera, and 48 described and 157 undescribed species of West Indian Anthribidae distributed from the Bahamas to Grenada. Each described genus has author, date, page, type species and how designated, World distribution, number of World species, and synonyms. Each described species has author, date, page, original generic name if a transfer has occurred, type locality, sex and location of type(s) if known, synonyms, and island-by-island distribution. New taxa are numbered, with data on museum location and island distribution. There are brief comments on New World distributions as they relate to the Antilles, and on missing Suffrian and Wolfrum types
Recommended from our members
State-Level and County-Level Estimates of Health Care Costs Associated with Food Insecurity.
IntroductionFood insecurity, or uncertain access to food because of limited financial resources, is associated with higher health care expenditures. However, both food insecurity prevalence and health care spending vary widely in the United States. To inform public policy, we estimated state-level and county-level health care expenditures associated with food insecurity.MethodsWe used linked 2011-2013 National Health Interview Survey/Medical Expenditure Panel Survey data (NHIS/MEPS) data to estimate average health care costs associated with food insecurity, Map the Meal Gap data to estimate state-level and county-level food insecurity prevalence (current though 2016), and Dartmouth Atlas of Health Care data to account for local variation in health care prices and intensity of use. We used targeted maximum likelihood estimation to estimate health care costs associated with food insecurity, separately for adults and children, adjusting for sociodemographic characteristics.ResultsAmong NHIS/MEPS participants, 10,054 adults and 3,871 children met inclusion criteria. Model estimates indicated that food insecure adults had annual health care expenditures that were 1,073-2,595, P < .001) higher than food secure adults. For children, estimates were 80 higher, but this finding was not significant (95% CI, -329, P = .53). The median annual health care cost associated with food insecurity was 239,675,000; 75th percentile, 4,433,000 (25th percentile, 11,267,000). Cost variability was related primarily to food insecurity prevalence.ConclusionsHealth care expenditures associated with food insecurity vary substantially across states and counties. Food insecurity policies may be important mechanisms to contain health care expenditures
- …
