Pyrethroid resistant and susceptible populations of horn flies were exposed to several insecticides including 3 pyrethroids, 2 organophosphates, 1 carbamate, DDT, and 3 synergist combinations. Horn ...flies were exposed to log-dose concentrations ranging from 5 X 10(-6) to 5 X 10 degrees mg/cm2 in both contact (irritancy) and noncontact (repellency) environments. This is the 1st clarification of the mechanisms of stimulus-dependent behavioral resistance in horn flies; the data demonstrate the existence of both irritancy and repellency. Significant differences in flight responses were observed between populations, indicating hypersensitivity of resistant flies in both contact and noncontact environments for several compounds. Resistant horn flies had lower sensitivity thresholds for permethrin, fenvalerate, pirimiphos-methyl, DDT, and fenvalerate with piperonyl butoxide (PBO) when compared with susceptible flies in the contact environment. Lower sensitivity thresholds for resistant horn flies were also observed for permethrin, diazinon, and diazinon-PBO in the noncontact environment. In addition, the flight response curve for the pyrethroid resistant population increased for all compounds in the contact environment and most compounds in the noncontact environment, whereas the response curve remained constant or decreased in the pyrethroid susceptible population. The increased irritability and repellency seen with the addition of the synergist in a resistant population exhibiting knockdown (physiological) resistance suggests that nongeneralized intoxication may be the sensory mechanism by which behavioral resistance occurs
ALICE (A Large Ion Collider Experiment) is a detector dedicated to the studies with heavy ion collisions exploring the physics of strongly interacting nuclear matter and the quark-gluon plasma at the ...CERN LHC (Large Hadron Collider). After the second long shutdown of the LHC, the ALICE Experiment will be upgraded to make high precision measurements of rare probes at low pT, which cannot be selected with a trigger, and therefore require a very large sample of events recorded on tape. The online computing system will be completely redesigned to address the major challenge of sampling the full 50 kHz Pb-Pb interaction rate increasing the present limit by a factor of 100. This upgrade will also include the continuous un-triggered read-out of two detectors: ITS (Inner Tracking System) and TPC (Time Projection Chamber)) producing a sustained throughput of 1 TB/s. This unprecedented data rate will be reduced by adopting an entirely new strategy where calibration and reconstruction are performed online, and only the reconstruction results are stored while the raw data are discarded. This system, already demonstrated in production on the TPC data since 2011, will be optimized for the online usage of reconstruction algorithms. This implies much tighter coupling between online and offline computing systems. An R&D program has been set up to meet this huge challenge. The object of this paper is to present this program and its first results.
Malaria has reemerged as a significant public health disease threat in Peru, especially within the Amazon Basin region. This resurgence of human cases caused by infection with Plasmodium falciparum ...and Plasmodium vivax is thought to be associated with the spread of Anopheles darlingi, the principal South American malaria vector, into new areas of the Amazon Basin. However, comprehensive studies of the distribution for this species have not been conducted in Peru for several years, nor are historical accounts accurate enough to determine if An. darlingi was actually present and not collected or misidentified. Therefore, the objective of this study is to define the distribution of An. darlingi as well as obtain data on distribution and abundance of other Anopheles species in this region. Mosquitoes were collected during 2001 in the Departments of Loreto and Ucayali, the two largest Amazonian Departments of Peru. A total of 60,585 specimens representing 12 species of the subgenera Nyssorhynchus and Anopheles were collected at 82 (88.2%) of 93 collecting sites. The majority of mosquitoes obtained were identified as An. benarrochi, comprising 70.7% of mosquitoes collected, followed by An. darlingi (24.0%), Anopheles mattogrosensis (2.4%), and Anopheles triannulatus (1.5%). Anopheles darlingi was collected from 48.8% of sites, indicating that this species is established throughout central Loreto, including further west in the Amazon Basin than previously reported. These data suggest that this species is now found in areas of the Amazon Basin region where it has not been previously reported.
Hantavirus activity in 39 National Parks in the eastern and central United States was surveyed by testing 1,815 small mammals of 38 species for antibody reactive to Sin Nombre virus. ...Antibody-positive rodents were found throughout the area sampled, and in most biotic communities. Antibody was detected in 7% of 647 deer mice (Peromyscus maniculatus), 2% of 590 white-footed mice (P. leucopus), 17% of 12 rice rats (Oryzomys palustris), 3% of 31 cotton rats (Sigmodon hispidus), and 33% of 18 western harvest mice (Reithrodontomys megalotis). Antibody was also found in three of six species of voles, and in one of 33 chipmunks (Tamias minimus). Prevalence among Peromyscus was highest in the northeast. Although few cases of hantavirus pulmonary syndrome have been identified from the eastern and central regions, widespread infection in reservoir populations indicates that potential exists for human infection throughout much of the United States.
North Florida is a transition zone between widespread Culex nigripalpus populations to the south and focal Culex salinarius populations to the north. Culex nigripalpus is a vector of St. Louis ...encephalitis (SLE) and eastern equine encephalitis (EEE) viruses in south Florida, while Cx. salinarius is a suspected New World vector of West Nile (WN) virus. Abundant vector populations are often a prerequisite for epidemic and epizootic transmission of arboviruses. Extensive SLE transmission has never been reported from north Florida, but sporadic WN transmission was reported there during the summer of 2001. The disparate flavivirus transmission patterns observed in north and south Florida may be due, in part, to the local geographical and seasonal distribution of Culex vectors. Here we report that from May 1991 to April 1994, Cx. salinarius was most commonly observed during the winter and spring in northeast Florida (Duval County), whereas Cx. nigripalpus was most abundant during the summer and autumn. An unusually mild spring in 1991 allowed Cx. nigripalpus to reproduce early in the year, resulting in a summer population that emerged more than 8 wks earlier than in 1992 and 1993. The 1991 Cx. nigripalpus population persisted through October, when SLE transmission was detected by sentinel chickens. Transmission of SLE was not detected in Duval County during 1992 or 1993. These data indicate that mild winter and spring conditions in north Florida may favor increased abundance and survival of Cx. nigripalpus in a region where this species is normally not abundant. A seasonal shift in population structure may increase the transmission risk of arboviruses for which Cx. nigripalpus is a competent vector, including SLE, WN, and EEE.
A checklist of the mosquito fauna encountered during arboviral studies in Iquitos, Peru, is presented. A total of 16 genera, 30 subgenera, and 96 species were identified, including 24 species ...reported from Peru for the 1st time. Notations on the taxonomy and biology for 28 species are also provided.
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