Evaluating the quality of citizen-scientist data on pollinator communities.

Concerns about pollinator declines have grown in recent years, yet the ability to detect changes in abundance, taxonomic richness, and composition of pollinator communities is hampered severely by the lack of data over space and time. Citizen scientists may be able to extend the spatial and temporal extent of pollinator monitoring programs. We developed a citizen-science monitoring protocol in which we trained 13 citizen scientists to observe and classify floral visitors at the resolution of orders or super families (e.g., bee, wasp, fly) and at finer resolution within bees (superfamily Apoidea) only. We evaluated the protocol by comparing data collected simultaneously at 17 sites by citizen scientists (observational data set) and by professionals (specimen-based data set). The sites differed with respect to the presence and age of hedgerows planted to improve habitat quality for pollinators. We found significant, positive correlations among the two data sets for higher level taxonomic composition, honey bee (Apis mellifera) abundance, non-Apis bee abundance, bee richness, and bee community similarity. Results for both data sets also showed similar trends (or lack thereof) in these metrics among sites differing in the presence and age of hedgerows. Nevertheless, citizen scientists did not observe approximately half of the bee groups collected by professional scientists at the same sites. Thus, the utility of citizen-science observational data may be restricted to detection of community-level changes in abundance, richness, or similarity over space and time, and citizen-science observations may not reliably reflect the abundance or frequency of occurrence of specific pollinator species or groups.

Venous occlusion plethysmography versus Doppler ultrasound in the assessment of leg blood flow during calf exercise.

This study explored the accuracy with which venous occlusion plethysmography (VOP) assesses the hyperaemic response during calf exercise. Using Doppler ultrasound (DU) as a criterion standard technique, we tested the hypotheses that leg blood flow during contraction is not greater than at rest and that VOP provides similar estimates of the hyperaemic response between contractions as DU. Eleven subjects performed several bouts of calf exercise across a wide range of forces (50-400 N â‰… 6-45%MVC). Each bout consisted of 2 min of intermittent contractions preceded and immediately followed by sustained (40 s) contractions. DU estimates of leg blood flow during the sustained contractions were never significantly greater (P > 0.05) than those measured at rest. Paired (DU and VOP) estimates of leg blood flow (n = 488) were obtained between intermittent contractions and ranged between ~50-900 ml min(-1). There was a strong correlation between these DU and VOP estimates (Pearson r = 0.91; P < 0.05). Ordinary least products regression analysis, with VOP as the y variable, showed a relatively small proportional bias (slope = 0.942; CI = 0.938-0.946) and fixed bias (y intercept = -13.3 ml min(-1); CI = -14.4 to -12.2 ml min(-1)) between the two measurement techniques. Since these small biases can be explained by the slight differences in vascular regions which the two techniques assess, these data suggest that VOP can accurately assess the hyperaemic response to exercise.

Vibration therapy reduces plasma IL6 and muscle soreness after downhill running.

OBJECTIVE: In this study, the effects of vibration therapy (VT) on delayed-onset muscle soreness (DOMS) and associated inflammatory markers after downhill running were determined. METHODS: 29 male recreational runners (33 (8) years; V(O2)peak 57 (6) ml kg(-1) min(-1)) completed a 40-min downhill run and were randomly allocated to a VT group or Control group. For 5 days post-run, the VT group underwent once-daily sessions of VT on the upper and lower legs. DOMS was assessed pre-run and for 5 days post-run by visual analogue scale. Immune cell subsets and plasma inflammatory markers were assessed pre-run, post-run, 24 and 120 h post-run by full differential cell count, and by ELISA and enzyme immunoassay, respectively. Data were analysed as per cent change from pre-run (ANOVA) and the magnitude of the treatment effect (Cohen's effect size statistics). RESULTS: VT significantly reduced calf pain 96 h post-run (-50% (40%), 90% confidence limits) and gluteal pain 96 h (-50% (40%)) and 120 h post-run (-30% (30%)); decreased interleukin 6 (IL6) 24 h (-46% (31%)) and 120 h post-run (-65% (30%)); substantially decreased histamine 24 h (-40% (50%)) and 120 h post-run (-37% (48%)); substantially increased neutrophils (8.6% (8.1%)) and significantly decreased lymphocytes (-17% (12%)) 24 h post-run. There were no clear substantial effects of VT on other leukocyte subsets and inflammatory markers. CONCLUSION: VT reduces muscle soreness and IL6. It may stimulate lymphocyte and neutrophil responses and may be a useful modality in treating muscle inflammation.

Leg heating and cooling influences running stride parameters but not running economy.

To evaluate the effect of temperature on running economy (RE) and stride parameters in 10 trained male runners (VO2peak 60.8 +/- 6.8 ml . kg (-1) . min (-1)), we used water immersion as a passive temperature manipulation to contrast localised pre-heating, pre-cooling, and thermoneutral interventions prior to running. Runners completed three 10-min treadmill runs at 70 % VO2peak following 40 min of randomised leg immersion in water at 21.0 degrees C (cold), 34.6 degrees C (thermoneutral), or 41.8 degrees C (hot). Treadmill runs were separated by 7 days. External respiratory gas exchange was measured for 30 s before and throughout the exercise and stride parameters were determined from video analysis in the sagittal plane. RE was not affected by prior heating or cooling with no difference in oxygen cost or energy expenditure between the temperature interventions (average VO2 3rd-10th min of exercise: C, 41.6 +/- 3.4 ml . kg (-1) . min (-1); TN, 41.6 +/- 3.0; H, 41.8 +/- 3.5; p = 0.94). Exercise heart rate was affected by temperature (H > TN > C; p < 0.001). During minutes 3 - 5 of running the respiratory-exchange and minute ventilation/oxygen consumption ratios were greater in cold compared with thermoneutral (p < 0.05). Averaged over the full 10 min of exercise, stride length was shorter and stride frequency higher for the C trial compared to TN and H (p < 0.01). Leg temperature manipulation did not influence running economy despite changes in stride parameters that might indicate restricted muscle-tendon elasticity after pre-cooling. Larger changes in stride mechanics than those produced by the current temperature intervention are required to influence running economy.

Is the IEMA combined incubator/shaker device preferable to a waterbath for incubating enzyme immunoassays?

An incubator/shaker device proved to be a convenient alternative to a waterbath for the incubation of enzyme immunoassays (EIA). The device achieved effective and even heat transfer. In two of five EIAs it increased reactivity and in three of five EIAs it slightly increased the discrimination between seronegative and seropositive specimens though, for the samples investigated, extra sensitivity was not thereby achieved. At a high shaking frequency (1400 rpm) there was cross-contamination between wells, but this did not occur at 900 rpm. The relative contributions of heating and of shaking to the incubation of EIAs deserve further investigation.

Dendritic cells are present in the alveolar region of lungs from specific pathogen-free rats.

The purpose of the present study was to establish the presence of dendritic cells in the alveolar region of rat lungs and determine whether they express the antigenic markers suggested in previous studies. We used pathogen-free rats to minimize changes in the cell populations due to subclinical infection and disease as inflammatory products can increase the number of dendritic cells in lungs. As an assay for accessory cells, proliferation of periodate-treated T cells was used. This is an accessory cell dependent response, and most importantly, dendritic cells, not macrophages, can act as accessory cells in this assay. Using this approach, lung cell suspensions, derived primarily from parenchymal tissue, were found to contain accessory cells. The accessory cell population was low density, radiation resistant, Fc receptor negative, nonadherent, and contained cells with similar morphology to dendritic cells from other tissues. About 90% of the accessory cell activity was lost upon depletion of MRC OX-6 (Ia) or MRC OX-1 (leukocyte common antigen, LCA) positive cells. The expression of LCA indicates that the accessory cells were bone marrow derived and not endothelial or epithelial cells. In contrast to suggestions from earlier studies, no loss in activity was seen when cell depletion was performed using CD-4 (W3/25) and macrophage specific (ED-2) antibodies. Thus, these cells appear to be functionally and phenotypically similar to dendritic cells isolated from other rat lymphoid tissues. However, they lack antigenic markers (CD-4 and ED-2) suggested to be expressed by alveolar dendritic cells as described in previous immunocytochemistry studies.

Mycoplasma pulmonis V-1 surface protein variation: occurrence in vivo and association with lung lesions.

The V-1 antigen of Mycoplasma pulmonis is exposed to the surface of the mycoplasma and has an immunoblot banding pattern that varies in vitro between and within strains. To determine if V-1 variation occurs in vivo, we infected C3H/HeNCr mice intranasally with 5 X 10(8) colony-forming units of M. pulmonis strain 5782C. We isolated M. pulmonis clones from the respiratory tracts of mice up to 28 days post-infection, then used anti-V-1 monoclonal antibody P39 to visualize their V-1 immunoblot banding patterns. By the 28th day following infection, 92% of the recovered clones had variant V-1 banding patterns. Additionally, there was a significant correlation between the severity of lung lesions and the percentage of V-1 variant clones recovered from the respiratory tracts of individual mice. These studies prove that V-1 variation does occur in vivo, and suggest that mice with more severe pulmonary lesions tend to have more V-1 variant clones as a percentage of the M. pulmonis population. Thus, variation in the V-1 protein may be a mechanism by which M. pulmonis persists in the in vivo environment, possibly by evasion of host immune surveillance or by alteration of its surface membrane to take better advantage of its environmental niche in the host.

Short-term exposure to nitrogen dioxide enhances susceptibility to murine respiratory mycoplasmosis and decreases intrapulmonary killing of Mycoplasma pulmonis.

In C57BL/6N and C3H/HeN mice known to be free of all murine pathogens and matched for age, sex, microbiologic, and environmental factors, exposure to NO2 for 4 h prior to exposure to infectious aerosols of Mycoplasma pulmonis resulted in potentiation of murine respiratory mycoplasmosis (MRM). In the C57BL/6N mice, NO2 increased the incidence of death, incidence of gross lung lesions, and incidence of microscopic lung lesions, but did not increase the incidence of infection in the lungs. Nitrogen dioxide affected the C3H/HeN mice (a strain known to be more susceptible than the C57BL/6N strain to MRM) similarly, with the exception that the incidence of death and microscopic lesions were not affected in this strain at the concentrations of M. pulmonis used. Exposure to the oxidant also increased the severity of microscopic lesions and the numbers of Mycoplasma organisms in the lungs of both mouse strains. Thus, NO2 appeared to affect host lung defense mechanisms responsible for limiting the extent of infection. The NO2 exposure level required to produce potentiation varied with the genetic background of the host, the number of Mycoplasma organisms administered, and the end point measured. In further experiments in C57BL/6N mice, exposure to 5 or 10 ppm of NO2 for 4 h prior to infection with aerosolized, radiolabeled M. pulmonis reduced clearance of these organisms from the lungs over a 72-h time period. Nitrogen dioxide exposure did not change the rate of physical removal of Mycoplasma organisms from the lung. Reduced clearance was due to impaired intrapulmonary killing of Mycoplasma organisms in NO2-exposed mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in sexual behaviour and risk factors for HIV infection among homosexual men, 1984-7.

To assess whether the spread of infection with HIV can be reduced by changes in behaviour among groups most at risk because of their sexual practices sexual behaviour was monitored among 1050 homosexual men tested for HIV infection at a genitourinary medicine clinic in west London from November 1984 to September 1987. Four cohorts, defined by date of presentation, were studied by questionnaire at their presentation, and blood samples were analysed. Between the first and last cohorts there was a considerable fall in the proportion reporting casual relationships (291/329 (88%) v 107/213 (50%] and high risk activities, such as anoreceptive intercourse with casual partners (262/291 (90%) v 74/106 (70%], with the greatest changes occurring before the government information campaign began in 1986. Nevertheless, half of the men in the last cohort studied reported having casual partners. Multiple logistic regression showed that behavioural risk factors for HIV infection most closely resembled those for hepatitis B and that previous sexually transmitted diseases (syphilis, hepatitis B, and anogenital herpes) were themselves independent risk factors. A history of syphilis ranked above anoreceptive intercourse as the strongest predictor of HIV infection. Actively bisexual men showed a much lower prevalence of HIV infection (3/57, 5%) than exclusively homosexual men (113/375, 30%). Sexual behaviour among homosexual men changed during the period studied, and the incidence of HIV infection fell, although more education programmes directed at homosexual men are needed to re-emphasise the dangers of infection.

Human immunodeficiency virus infection, hepatitis B virus infection, and sexual behaviour of women attending a genitourinary medicine clinic.

During the six months immediately after a public information campaign about the acquired immune deficiency syndrome 1115 women who attended a genitourinary medicine clinic in west London were tested for antibodies to the human immunodeficiency virus (HIV). Three women (0.27%) were positive, and all three were regular sexual partners of men with high risk lifestyles--two intravenous drug users and one bisexual. A consecutive series of 647 women from the cohort was tested for antibodies for hepatitis B core antigen: 27 were positive, of whom six had been born in the United Kingdom and were not known to have been at risk. The two women who were seropositive for HIV who completed a questionnaire on their sexual behaviour before they were tested reported both anal and oral receipt of semen and were in the upper fifth percentile for lifetime sexual partners. More than half (53%) of 424 women who reported that they had non-regular sexual partners never used a condom. It is concluded that heterosexual women in London are at a low risk of becoming infected with HIV.

PIP: A cohort of women were screened for sexual behavior and for antibodies to HIV and hepatitis B. These women attended a clinic for sexually transmitted diseases in an area of London where homosexual men have a high prevalence of both infections. The spread of AIDS among heterosexuals is likely to appear 1st in women who are partners of bisexual men and in localities where the prevalence of HIV infection in homosexual men is the highest. Of 115 women who were tested, 3 women (0.27%) were positive, and all 3 were regular sexual partners of men with high risk lifestyles--2 intravenous drug users and 1 bisexual. A consecutive series of 647 women from the cohort was tested for antibodies for hepatitis B core antigen: 27 were positive, of whom 6 had been born in the U.K. and were not known to have been at risk. The 2 who were seropositive for HIV and who had completed a questionaire on their sexual behavior before testing reported both anal and oral receipt of semen and were in the upper 5th percentile for lifetime sexual partners. More than 1/2 (53%) of 424 women who reported that they had nonregular sexual partners never used a condom. Patients at risk for HIV infection are also at greater risk of hepatitis B infection. Prevalence of hepatitis B infection among patients in genito-urinary medicine clinics has been reported at 4% to 8% for women compared with 4% to 18% for heterosexual men and 19% to 76% for homosexual men. Women in west London showed a low prevalence of hepatitis B, and most of those women were born outside the U.K. and may have been infected since childhood. The advice of a recent national campaign to use condoms seems to have had little effect. However, it appears from this group of women that there is no evidence of HIV infection being spread from casual vaginal intercourse. The risk of becoming infected with HIV for heterosexual women in London is very low and is likely to remain so if the epidemiological parallel with hepatitis B is valid.

Pulmonary clearance of Mycoplasma pulmonis in C57BL/6N and C3H/HeN mice.

In C57BL/6N and C3H/HeN mice known to be free of all murine pathogens and matched for age, sex, and environmental factors, pulmonary clearance was measured over a 72-h time period after exposure to infectious aerosols of 35S-labeled Mycoplasma pulmonis. Reduced clearance of M. pulmonis in C3H/HeN mice relative to C57BL/6N mice was primarily due to impaired mycoplasmacidal activity in the lungs of the C3H/HeN mice. The C3H/HeN mice also had a slightly slower rate of mechanical transport of radiolabel from the lungs in the first 4 h after infection relative to the C57BL/6N mice but not at any later times. By 72 h after infection (relative to 0 h, C3H/HeN mice had an over 4,000% (1.75 X 10(7) versus 4.30 X 10(5] increase in neutrophils and an over 18,000% (more than 2 orders of magnitude) increase in numbers of M. pulmonis recovered from mechanically disaggregated lungs. In contrast, C57BL/6N mice reduced the number of M. pulmonis present by over 83% (nearly 2 orders of magnitude) before any increase in inflammatory cells, which was only a slight increase in lymphocytes and macrophages at 24 h after infection. These results directly link decreased mycoplasmal pulmonary clearance in C3H/HeN mice with the increased susceptibility to, and severity of, murine respiratory mycoplasmosis observed in this strain. The resistance of C57BL/6N mice appears to be related to nonspecific host defense mechanisms responsible for limiting the extent of infection.

Development of an aerosol model of murine respiratory mycoplasmosis in mice.

Animal models of murine respiratory mycoplasmosis due to Mycoplasma pulmonis provide excellent opportunities to study respiratory disease due to an infectious agent. The purpose of the present study was to develop and characterize an aerosol model for the production of murine respiratory mycoplasmosis in mice. The exposure of mice for 30 min to aerosols generated with a DeVilbiss 45 nebulizer in a nose-only inhalation chamber consistently reproduced typical lesions. The chamber was operated with a nebulizer air flow of 5.3 liters/min at 5.0 lb/in and a diluting air flow of 20 liters/min, with the nebulizer containing 5 ml of a suspension of viable M. pulmonis organisms (a concentration between 6 X 10(5) to 6 X 10(10) CFU/ml). Infective aerosol particles of less than a 4.0-micron median aerodynamic diameter with a geometric standard deviation of approximately 2.0 reached the lungs and were evenly distributed among the different lung lobes. A minimum 1.5-log loss of viability in the M. pulmonis suspension was demonstrated. With the exception of the 50% lethal dose, all of the parameters previously established by intranasal inoculation could be examined with the aerosol model. The major advantages of the aerosol model were excellent reproducibility of exposure (both between different experiments and between animals in a given experiment), the avoidance of anesthetization, and the ability to immediately deposit the majority of the organisms in the lung. The only disadvantage was the requirement for large volumes of mycoplasmal cultures.

Nonspecific lymphocyte responses in F344 and LEW rats: susceptibility to murine respiratory mycoplasmosis and examination of cellular basis for strain differences.

Mycoplasma pulmonis produces a mitogen which may play a role in the pathogenesis of murine respiratory mycoplasmosis in rats. Since LEW rats are more susceptible to this disease than F344 rats are, these two strains were used to examine a possible association between disease severity and the level of nonspecific lymphocyte stimulation by mitogens, including M. pulmonis membrane preparations. F344 and LEW spleen, lung, blood, and lymph node lymphocytes were exposed to various mitogens. LEW lymphocytes gave a significantly higher response to mitogenic stimulation, regardless of their anatomical source. These differences in lymphocyte responsiveness were primarily due to differences within the nonadherent cell population. Significantly higher numbers of W3/25+ (T helper) cells were found in LEW lymphoid populations, whereas no difference was found in MRC OX-8+ (T suppressor/cytotoxic) cells. These data suggest an association between disease severity and host responsiveness to nonspecific stimuli.

Clinical evaluation of a monoclonal assay for hepatitis B surface antigen: identification of "HBsAg-like" polypeptides non-reactive in conventional radioimmunoassays.

An immunoradiometric assay for hepatitis B surface antigen (HBsAg) that employs monoclonal antibodies directed against the common epitope(s) of HBsAg was used to analyse 3,694 samples of human serum. Further analysis of those sera identified as HBsAg-positive in this assay demonstrated that the findings with the monoclonal-antibody-based assay correlated with the presence of HBsAg as determined by Austria II. A small proportion of apparently false-positive reactions were observed, in that some sera, although reactive with the monoclonal antibodies, were not positive in conventional immunoassays using polyclonal antisera, nor were they neutralisable with polyclonal anti-HBs. The material purified by monoclonal immunoabsorbants from representative "true" and "false-positive" sera was run on polyacrylamide gels and examined under the electron microscope. The antigen in the apparently false-positive sera contained some polypeptides of similar size to those found in HBsAg, but no virus particles were seen by electron microscopy. The majority of patients with this monoclonal-antibody-reactive antigen gave either a history of hepatitis B virus (HBV) contact or had signs of liver disease.

Murine respiratory mycoplasmosis in F344 and LEW rats: evolution of lesions and lung lymphoid cell populations.

By comparison of two strains, LEW and F344, which are known to differ in susceptibility to Mycoplasma pulmonis respiratory disease, it was shown that differences in lesion severity and progression were associated with changes in lung lymphocyte populations. Lung lesions in LEW rats developed earlier after infection, became more severe, and were characterized by continued proliferation of all classes of lymphoid cells, T lymphocytes, B lymphocytes, and plasma cells, throughout the 120-day observation period. In contrast, lymphoid proliferation in F344 rats reached a plateau at 28 days and was restricted to an increase in T lymphocytes, immunoglobulin A (IgA)-bearing B lymphocytes, and IgA and IgG plasma cells. Although approximately 10 times as many IgG B cells and 4 times as many IgG plasma cells were found in infected LEW rats as compared with F344 rats, the specific anti-M. pulmonis IgG response in the two strains was roughly parallel. The same relationships held true, although to a lesser extent, for specific IgA antibody responses and cellular responses. Whereas lung lesions showed a tendency to resolve in F344 rats by 120 days, severe lesions persisted in LEW rats. The disparity between the cellular response and specific antibody response, the seemingly uncontrolled lymphocyte proliferation in LEW rats, and the mitogenic potential of M. pulmonis suggest that differences between LEW and F344 rats in lung lesion severity and progression are related to differences in the degree of nonspecific lymphocyte activation in the two strains, an imbalance in regulation of lymphocyte proliferation in LEW rats, or both.

Air embolism in association with LeVeen shunt.

Although the LeVeen shunt has been used in the treatment of abdominal ascites, it has not been without complications. Pulmonary air embolism secondary to colonic perforation occurred in a patient with ascites and a LeVeen shunt. This resulted in cardiovascular collapse and eventual death. Because of this complication, the LeVeen shunt should be occluded before entering the peritoneal cavity.

Immunofluorescent characterization of lymphocytes in lungs of rats infected with Mycoplasma pulmonis.

Immunofluorescence was used to determine the relative percentages of T and B lymphocytes found in the lungs of normal and Mycoplasma pulmonis-infected F344 rats. Lymphocytes recovered from controls were approximately 25% T, 25% B, and 50% unclassified mononuclear cells. Infected animals had a 2.6-fold greater number of T cells and IgA-bearing cells, and a 1.6-fold greater number of unclassified mononuclear cells. These studies show that M. pulmonis infection significantly alters lung lymphocyte populations both quantitatively and in subpopulation distribution. Therefore, future studies of rat lung lymphocytes should utilize animals known to be free of this ubiquitous respiratory pathogen.