Hygiene-Eliciting Brood Semiochemicals as a Tool for Assaying Honey Bee (Hymenoptera: Apidae) Colony Resistance to Varroa (Mesostigmata: Varroidae).

Despite numerous interventions, the ectoparasitic mite Varroa (Varroa destructor Anderson and Trueman [Mesostigmata: Varroidae]) and the pathogens it vectors remain a primary threat to honey bee (Apis mellifera Linnaeus [Hymenoptera: Apidae]) health. Hygienic behavior, the ability to detect, uncap, and remove unhealthy brood from the colony, has been bred for selectively for over two decades and continues to be a promising avenue for improved Varroa management. Although hygienic behavior is expressed more in Varroa-resistant colonies, hygiene does not always confer resistance to Varroa. Additionally, existing Varroa resistance selection methods trade efficacy for efficiency, because those achieving the highest levels of Varroa resistance can be time-consuming, and thus expensive and impractical for apicultural use. Here, we tested the hypothesis that hygienic response to a mixture of semiochemicals associated with Varroa-infested honey bee brood can serve as an improved tool for predicting colony-level Varroa resistance. In support of our hypothesis, we demonstrated that a mixture of the compounds (Z)-10-tritriacontene, (Z)-8-hentriacontene, (Z)-8-heptadecene, and (Z)-6-pentadecene triggers hygienic behavior in a two-hour assay, and that high-performing colonies (hygienic response to ≥60% of treated cells) have significantly lower Varroa infestations, remove significantly more introduced Varroa, and are significantly more likely to survive the winter compared to low-performing colonies (hygienic response to <60% of treated cells). We discuss the relative efficacy and efficiency of this assay for facilitating apiary management decisions and selection of Varroa-resistant honey bees, as well as the relevance of these findings to honey bee health, pollination services, and social insect communication.

Stock-specific chemical brood signals are induced by Varroa and Deformed Wing Virus, and elicit hygienic response in the honey bee.

The health of the honey bee Apis mellifera is challenged by the ectoparasitic mite Varroa destructor, and the numerous harmful pathogens it vectors. Existing pesticide-based Varroa controls are not sustainable. In contrast, one promising approach for improved honey bee health is the breeding of hygienic bees, capable of detecting and removing brood that is parasitized or diseased. In three experiments we find evidence to support the hypothesis that stock-specific chemical brood signals are induced by Varroa and Deformed Wing Virus, and elicit hygienic response in the honey bee. By collecting, analyzing, and running bioassays involving mite-infested and control brood extracts from three honey bee breeding stocks we: 1) found evidence that a transferrable chemical signal for hygienic behavior is present in Varroa-infested brood extracts, 2) identified ten stock-specific hydrocarbons as candidates of hygienic signaling, and 3) found that two of these hydrocarbons linked to Varroa and DWV were also elevated in brood targeted for hygienic behavior. These findings expand our understanding of honey bee chemical communication, and facilitate the development of improved hygienic selection tools to breed honey bees with greater resistance to Varroa and associated pathogens.

Evaluation of SV40-transformed synovial fibroblasts in the study of rheumatoid arthritis pathogenesis.

The SV40 T antigen has been used to generate immortalized cells from rheumatoid arthritis (RA) synovial fibroblasts (RASFs) that are commonly used in lieu of primary RASFs. In the current study, we investigated the effect of stimulation by tissue necrosis factor alpha (TNF-α) and interleukin 17 (IL-17) on primary and immortalized RASFs in order to gauge the appropriateness of the use of immortalized RASFs, the MH7A cell line, in the study of RA pathogenesis. Changes in the levels of secretion and expression of 8 proteins associated with RA upon stimulation were assessed by multiplex immunoassay. IL-17 stimulation had a minimal impact on protein secretion and expression for primary and immortalized cells. Basic fibroblast growth factor (FGF-2) was not detectable for the primary cells but was detectable for the immortalized cells. In contrast, monocyte chemoattractant protein 1 (MCP-1) was detectable for primary cells but was undetectable for immortalized cells. In general, protein expression and secretion by cells stimulated with TNF-α were significantly increased. For primary cells, several proteins were below the limit of detection for unstimulated cells and cells stimulated with IL-17, while levels for TNF-α-stimulated cells were within the detectable range. For the same proteins, expression was observed for immortalized cells, regardless of stimulation, suggestive of constitutive activation of the NF-κB signaling pathway. The current study therefore provides strong evidence that immortalized and primary RASFs differ in regard to protein expression and secretion and therefore may not be appropriate for use in the study of RA pathogenesis.

Modulation of the response of rheumatoid arthritis synovial fibroblasts to proinflammatory stimulants with cyclic tensile strain.

Although physical therapy has been shown to be an effective method for treatment of rheumatoid arthritis, a thorough investigation on the impact of mechanical signals upon the complex cytokine network associated with pathogenesis has not yet been conducted. In the current study, our research group investigated the effect of mechanical stimulation on primary and immortalized rheumatoid arthritis synovial fibroblasts (RASFs) through analysis of secreted proteins using multiplex immunoassay. Equibiaxial tensile strain was applied to 2D cultures grown on collagen-coated, flexible silicone membranes at a magnitude of 10% and a frequency of 0.5Hz using the Flexcell System. After 24h, supernatant was removed and assayed for the following cytokines: IL-1beta, IL-6, IL-8, VEGF, FGF-2, GM-CSF, MCP-1, RANTES, TNF-alpha. The results were compared to unstimulated control groups. Mechanical stimulation alone only impacted secretion of IL-8 by primary RASFs. However, in the presence of proinflammatory mediators (TNF-alpha or IL-17), application of cyclic tensile strain increased secretion of a number of proteins by both primary and immortalized RASFs, although the responses were not analogous. In contrast, MCP-1 secretion was decreased when mechanical stimulation was applied in combination with IL-17 to primary cultures. In general, the study suggests that cyclic tensile strain can be used to modulate the effects of proinflammatory stimulants on RASFs; however, given the highly variable results, more research will be necessary to identify the pathways that are implicated in mechanotransduction.

Risk factors for Nipah virus encephalitis in Bangladesh.

Nipah virus (NiV) is a paramyxovirus that causes severe encephalitis in humans. During January 2004, twelve patients with NiV encephalitis (NiVE) were identified in west-central Bangladesh. A case-control study was conducted to identify factors associated with NiV infection. NiVE patients from the outbreak were enrolled in a matched case-control study. Exact odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by using a matched analysis. Climbing trees (83% of cases vs. 51% of controls, OR 8.2, 95% CI 1.25-infinity) and contact with another NiVE patient (67% of cases vs. 9% of controls, OR 21.4, 95% CI 2.78-966.1) were associated with infection. We did not identify an increased risk for NiV infection among persons who had contact with a potential intermediate host. Although we cannot rule out person-to-person transmission, case-patients were likely infected from contact with fruit bats or their secretions.

Design and performance of a sub-nanoradian resolution autocollimating optical lever.

Precision goniometry using optics has the advantage that it does not impose much stress on the object of investigation and, as such, is adopted extensively in gravitational wave detection, in torsion balances investigating fundamental forces, in specialized studies of biological samples, and it has potential applications in condensed matter physics. In this article we present the considerations that go into designing optical levers and discuss the performance of the instrument we have constructed. We motivate the design by considering an idealized setup and the limitations to the angular resolution induced by statistical fluctuations of the photon count rate and diffraction at the apertures. The effects of digitization of the count rate and of the spatial location of the photons on the image plane motivating the actual design are discussed next. Based on these considerations, we have developed an autocollimating optical lever which has a very high resolution and dynamic range. An array of 110 slits, of 90 microm width and a pitch of 182 microm, is located in the focal plane of a field lens, of focal length 1000 mm, and is illuminated by a CCFL tube. This array is imaged back onto the focal plane after retroreflection from a mirror placed just beyond the lens. The image is recorded on a linear charge-coupled device array at the rate of 1000 images/s and is processed through a special algorithm to obtain the centroid. The instrument has a centroid stability of approximately 3 x 10(-10) rad Hz(-1/2) and a dynamic range of approximately 10(7).

Different expression and activity of the alpha1 and alpha4 isoforms of the Na,K-ATPase during rat male germ cell ontogeny.

Two catalytic isoforms of the Na,K-ATPase, alpha1 and alpha4, are present in testis. While alpha1 is ubiquitously expressed in tissues, alpha4 predominates in male germ cells. Each isoform has distinct enzymatic properties and appears to play specific roles. To gain insight into the relevance of the Na,K-ATPase alpha isoforms in male germ cell biology, we have studied the expression and activity of alpha1 and alpha4 during spermatogenesis and epididymal maturation. This was explored in rat testes at different ages, in isolated spermatogenic cells and in spermatozoa from the caput and caudal regions of the epididymis. Our results show that alpha1 and alpha4 undergo differential regulation during development. Whereas alpha1 exhibits only modest changes, alpha4 increases with gamete differentiation. The most drastic changes for alpha4 take place in spermatocytes at the mRNA level, and with the transition of round spermatids into spermatozoa for expression and activity of the protein. No further changes are detected during transit of spermatozoa through the epididymis. In addition, the cellular distribution of alpha4 is modified with development, being diffusely expressed at the plasma membrane and intracellular compartments of immature cells, finally to localize to the midregion of the spermatozoon flagellum. In contrast, the alpha1 isoform is evenly present along the plasma membrane of the developing and mature gametes. In conclusion, the Na,K-ATPase alpha1 and alpha4 isoforms are functional in diploid, meiotic and haploid male germ cells, alpha4 being significantly upregulated during spermatogenesis. These results support the importance of alpha4 in male gamete differentiation and function.

Field evaluation of a method for estimating gaseous fluxes from area sources using open-path Fourier transform infrared.

This paper describes results from the first field experiment designed to evaluate a new approach for quantifying gaseous fugitive emissions of area air pollution sources. The approach combines path-integrated concentration data acquired with any path-integrated optical remote sensing (PI-ORS) technique and computed tomography (CT) technique. In this study, an open-path Fourier transform infrared (OP-FTIR) instrument sampled path-integrated concentrations along five radial beam paths in a vertical plane downwind from the source. A meteorological station collected measurements of wind direction and wind speed. Nitrous oxide (N2O) was released from a controlled area source simulator. The innovative CT technique, which applies the smooth basis function minimization method to the beam data in conjunction with measured wind data, was used to estimate the total flux from the simulated area source. The new approach estimates consistently underestimated the true emission rates in unstable atmospheric conditions and agreed with the true emission rate in neutral atmospheric conditions. This approach is applicable to many types of industrial areas or volume sources, given the use of an adequate PI-ORS system.

Effectiveness of glycerol as a rehydrating agent.

On two occasions, 8 male subjects completed a dehydration protocol, immediately followed by a 180-min rehydration protocol, then a subsequent exercise bout. During each dehydration session, subjects lost 3.1 +/- 0.4% body weight (BW) following discontinuous exercise in the heat (40 degreesC, 33% rh). During the first 30 min of rehydration, subjects ingested either 1.0-g glycerol x kg body weight(-1) + 30% of the total rehydration water volume (GLY), or 30% of the total rehydration water volume without glycerol (CON). The five remaining ingestions (every 30 min) were equal to 14% of the remaining fluid volume and were identical in nature. Fluid volume ingested equaled fluid volume lost during dehydration. Following the 180 min rehydration period, subjects cycled (appoximately 50% VO2 peak) in the heat (40 degrees C, 33% rh) until volitional exhaustion. Three observations were made: (a) Following glycerol-induced rehydration, time to volitional exhaustion was greater during the subsequent exercise bout in the heat (CON: 38.0 +/- 2.0, GLY 42.8 +/- 1.0 min, p <.05); (b) glycerol-induced rehydration significantly increased plasma volume restoration within 60 min and at the end of the 180-min rehydration period; and (c) total urine volume was lower and percent rehydration was greater following GLY, but neither was significantly different.

Lassa fever in Guinea: I. Epidemiology of human disease and clinical observations.

The arenavirus Lassa is found in West Africa, where it sometimes causes a severe illness called Lassa fever. Lassa fever has been seldom investigated outside of a few hyperendemic regions, where the described epidemiology may differ from that in areas of low or moderate incidence of disease. Through a prospective cohort study, we investigated the epidemiology and clinical presentation of Lassa fever in Guinea, where the disease has been infrequently recognized. A surveillance system was established, and suspected cases were enrolled at five Guinean hospitals. Clinical observations were made, and blood was taken for enzyme-linked immunosorbent assay testing and isolation of Lassa virus. Lassa fever was confirmed in 22 (7%) of 311 suspected cases. Another 43 (14%) had Lassa IgG antibodies, indicating past exposure. Both sexes and a wide variety of age and ethnic groups were affected. The disease was more frequently found, and the IgG seroprevalence generally higher, in the southeastern forest region. In some areas, there were significant discrepancies between the incidence of Lassa fever and the prevalence of antibody. Clinical presentations between those with Lassa fever and other febrile illnesses were essentially indistinguishable. Clinical predictors of a poor outcome were noted, but again were not specific for Lassa fever. Case-fatality rates for those with Lassa fever and non-Lassa febrile illnesses were 18% and 15%, respectively. Seasonal fluctuation in the incidence of Lassa fever was noted, but occurred similarly with non-Lassa febrile illnesses. Our results, perhaps typical of the scenario throughout much of West Africa, indicate Lassa virus infection to be widespread in certain areas of Guinea, but difficult to distinguish clinically.

Lassa fever in Guinea: II. Distribution and prevalence of Lassa virus infection in small mammals.

Rodents of the genus Mastomys form the reservoir for Lassa virus (LV), an arenavirus that causes a potentially severe hemorrhagic illness, Lassa fever (LF). Although Mastomys rodents exist throughout sub-Saharan Africa, areas of human LF appear to be quite focal. The distribution of small mammals and LV-infected Mastomys has been assessed in only a few countries. We conducted a survey of small mammals in selected regions of Guinea to assess the degree to which LV poses a public health risk in that country. A total of 1,616 small mammals, including 956 (59%) Mastomys, were captured from 444 households and seven bush sites. Mastomys made up > 90% of the captured animals in the savannah, savannah-forest transition, and forest regions of Guinea, while Mus musculus dominated in coastal and urban sites. Animals were analyzed via enzyme-linked immunosorbent assay (ELISA) for LV-specific antigen (blood and spleen homogenate) and IgG antibody (blood only). Virus isolation from spleen homogenates was also performed on a subset of animals. Lassa antibody and antigen were found in 96 (11%) and 46 (5%), respectively, of 884 tested Mastomys. Antibody and antigen were essentially mutually exclusive and showed profiles consistent with vertical transmission of both LV and antibody. LV was isolated only from Mastomys. ELISA antigen constituted an acceptable surrogate for virus isolation, with a sensitivity and specificity when performed on blood of 78% (95% confidence interval: 68-83%) and 98% (95-99%), respectively. The proportion of LV-infected Mastomys per region ranged from 0 to 9% and was highest in the savannah and forest zones. The proportion of infected animals per village varied considerably, even between villages in close proximity. Infected animals tended to cluster in relatively few houses, suggesting the existence of focal "hot spots" of LV-infected Mastomys that may account for the observed heterogeneous distribution of LF.

Diagnosis and clinical virology of Lassa fever as evaluated by enzyme-linked immunosorbent assay, indirect fluorescent-antibody test, and virus isolation.

The Lassa virus (an arenavirus) is found in West Africa, where it sometimes causes a severe hemorrhagic illness called Lassa fever. Laboratory diagnosis has traditionally been by the indirect fluorescent-antibody (IFA) test. However, enzyme-linked immunosorbent assays (ELISAs) for Lassa virus antigen and immunoglobulin M (IgM) and G (IgG) antibodies have been developed that are thought to be more sensitive and specific. We compared ELISA and IFA testing on sera from 305 suspected cases of Lassa fever by using virus isolation with a positive reverse transcription-PCR (RT-PCR) test as the "gold standard." Virus isolation and RT-PCR were positive on 50 (16%) of the 305 suspected cases. Taken together, Lassa virus antigen and IgM ELISAs were 88% (95% confidence interval [CI], 77 to 95%) sensitive and 90% (95% CI, 88 to 91%) specific for acute infection. Due to the stringent gold standard used, these likely represent underestimates. Diagnosis could often be made on a single serum specimen. Antigen detection was particularly useful in providing early diagnosis as well as prognostic information. Level of antigenemia varied inversely with survival. Detection by ELISA of IgG antibody early in the course of illness helped rule out acute Lassa virus infection. The presence of IFA during both acute and convalescent stages of infection, as well as significant interobserver variation in reading the slides, made interpretation difficult. However, the assay provided useful prognostic information, the presence of IFA early in the course of illness correlating with death. The high sensitivity and specificity, capability for early diagnosis, and prognostic value of the ELISAs make them the diagnostic tests of choice for the detection of Lassa fever.

Crimean-congo haemorrhagic fever: a seroepidemiological and tick survey in the Sultanate of Oman.

In 1995 and 1996, 4 persons from the Sultanate of Oman were confirmed with clinical Crimean-Congo haemorrhagic fever (CCHF). To assess the prevalence of CCHF virus infection in Oman, a convenience sample of imported and domestic animals from farms, abattoirs and livestock markets was examined by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to CCHF virus. Ticks were collected from selected animals, identified, pooled by species, host and location and tested for evidence of infection with CCHF virus by antigen-capture ELISA. Serum samples from individuals working in animal and nonanimal contact-related jobs were also tested for CCHF antibodies. Serological evidence of infection was noted in 108 (22%) of 489 animals. Most of the ticks collected (618 of 912) from all species of sampled livestock were Hyalomma anatolicum anatolicum, a competent vector and reservoir of CCHF virus. 243 tick pools were tested for CCHF antigen, and 19 pools were positive. Of the individuals working in animal contact-related jobs, 73 (30.3%) of 241 non-Omani citizens and only 1 (2.4%) of 41 Omani citizens were CCHF antibody-positive. Butchers were more likely to have CCHF antibody than persons in other job categories. The presence of clinical disease and the serological results for animals and humans and infected Hyalomma ticks provide ample evidence of the presence of CCHF virus in yet another country in the Arabian Peninsula.

A comparison of two criterion-referenced standard setting procedures for sports skills testing.

The application of criterion-referenced (CR) standard setting procedures in physical education has been limited to the examinee-centered model known as criterion groups. Alternative examinee-centered approaches are available but have not been applied in sport skills testing. The purpose of this study was to compare two examinee-centered models for setting performance standards for a sport skills test battery. CR performance standards were determined for the tennis skills test battery published in Tennis skills test manual (Hensley, 1989) using the borderline group (BG) (Livingston & Zieky, 1982) and criterion groups (CG) (Berk, 1976) models. The comparison of these two methods demonstrated that the CG method consistently produced performance standards that were lower than the BG method. In one instance the BG method produced a standard that was clearly unreasonable. Estimates of CR reliability for the CG standards (.76 less than or equal to P less than or equal to .93; .52 less than or equal to Kq less than or equal to .86) were higher than BG estimates (.55 less than or equal to P less than or equal to .84; .11 less than or equal to Kq less than or equal to .68). Although each method has strengths, neither is without problems. Results from this study suggest these two methods might be combined to minimize the problems associated with each. This combined method should produce standards with improved accuracy, validity, and reliability.