16 research outputs found
The canopy, bark, soil and litter invertebrate fauna of the Darling Plateau and adjacent woodland near Perth, Western Australia, with reference to the diversity of forest and woodland invertebrates
This paper tables and reports on pooled taxonomic data from three separate research projects involving aspects of eucalypt invertebrate ecology; canopy invertebrates in jarrah and marri forest; bark invertebrates on four eucalypt species in forest and woodland; and soil and litter fauna in jarrah and marri forest. The data support the concept of a high invertebrate biodiversity on and under southwestern eucalypts, with 1,234 adult morphospecies of invertebrates being collected from the bark alone. Despite different trapping methods used in each of the three studies, we were able to find a high degree of overlap at the family level between bark and canopy fauna (126 families were found on both bark and in the canopy representing 79.2% of 159 canopy families). Eighty identified genera were also found on both bark and canopy, which represents 46.2% of the 173 identified canopy genera. The soil and litter fauna data are not complete (a taxonomic inventory of Acarina and Formicidae is not available) but appears to be more distinctive, sharing 24 families (=60% of the 40 identified soil-litter families) with bark, and 17 families (=42.5% of the soil-litter families) with the canopy. At the generic level, only seven identified genera (=8.6% of 22 soil-litter genera) were shared between soil-litter and bark, and five genera (=6.2% of soil-litter genera) were shared between soil-litter and the canopy.An examination of the trophic guilds reveals that fungivores-decomposers were very diverse in soil and litter (accounting for approximately 50% of the biodivesity in these substrates). This guild was much less diverse on the canopy (21.6% of the canopy diversity) and the bark (16.9% of bark diversity). Sap-sucking organisms were more diverse in soil (13.9%) and litter (12.8%) than on the canopy (5.3%) or on the bark (5.9%). The canopy result is surprising, and suggests that not many invertebrates species are able to feed on the sap of southwestern eucalypts, the sap of which may contain a high proportion of toxic compounds. Predators were more diverse on the canopy and on bark (=19-23% of total taxa) than in soil and litter (=9-9.5%), as were parasitoids (18.7% and 22.5% compared with 10.5% and 14.8%). Epiphyte grazers and phytophages were not very diverse (plus/minus 11%) on any of the substrates, and representatives of other guilds or organisms whose diet was unknown accounted for less than 2.5% of the total diversity. Tourist species were not recognised among the soil and litter fauna, though they were found in the canopy and on bark, and ants were not quantified for soil and litter
A checklist of canopy, bark, soil and litter fauna of the Darling Plateau and adjacent woodland near Perth, Western Australia, with reference to the conservation of forest and woodland fauna
This paper tables and reports on pooled taxonomic data from three separate research projects involving aspects of eucalypt invertebrate ecology: canopy invertebrates in jarrah and marri forest; bark invertebrates on four eucalypt species in forest and woodland; and soil and litter fauna in jarrah and marri forest. The data support the notion of a high invertebrate biodiversity on and under southwestern eucalypts, with 1234 adult morphospecies of invertebrates being collected fiom the bark alone. Despite different trapping methods used in each of the three studies, we were able to find a high degree of overlap at the family level between bark and canopy fauna. (126 families were found on both bark and in the canopy representing 79.2% of 159 canopy families). Eighty identified genera were also found on both bark and canopy, which represents 46.2% of the 173 identified canopy genera. The soil and litter fauna data are not complete (a taxonomic inventory of Acarina and Forrnicidae is not available) but appear to be more distinctive, sharing only 24 families (=60% of the 40 identified soil-litter families) with bark, and 17 families (=42.5% of the soil-litter families) with the canopy. At the generic level, only seven identified genera (=8.6% of 22 soil-litter genera) were shared between soil-litter and bark, and five genera (=6.2% of soil-litter genera) were shared between soil-litter and the canopy.An examination of the trophic guilds reveals that fungivores-decomposers were very diverse in soil and litter, accounting for approximately 50% of the biodiversity in these substrates. This guild was much less diverse on the canopy (21.6% of the canopy diversity) and the bark (16.9% of bark diversity). Sap-sucking organisms were more diverse in soil (13.9%) and litter (12.8%) than on the canopy (5.3%) or on bark (5.9%). The canopy result is surprising and suggests that not many invertebrate species are able to feed on the sap of southwestern eucalypts, whose sap may contain a high proportion of toxic compounds. Predators were more diverse on the canopy and on bark (19-23% of total taxa) than in soil and litter (9-9.5%), as were parasitoids (18.7% and 22.5% compared with 10.5% and 14.8%). Epiphyte grazers and phytophageh were not very common (plus or minus 11%) on any of the substrates, while representatives of other guilds or organisms whose diet was unknown accounted for less than 2.5% of the total diversity. Tourist species were not recognised among the soil and litter fauna, though they were found in the canopy and on bark and ants were not quantified for soil and litter.A typical southwestern Australian eucalypt is thus an important host for very many invertebrates which occupy a wide range of trophic guilds. Should the system be altered, the result could be a catastrophic simplification of the invertebrate fauna presently found in eucalypt communities. Ultimately, many vertebrates and plants dependent on that invertebrate fauna for food, pollination and other processes would also disappear
The development of the pulmonary surfactant system in California sea lions
Natalie J. Miller, Anthony D. Postle, Samuel Schürch, W. Michael Schoel, Christopher B. Daniels, Sandra Orgei
Preexposure Prophylaxis for HIV Infection Integrated With Municipal- and Community-Based Sexual Health Services
ImportanceSeveral randomized clinical trials have demonstrated the efficacy of preexposure prophylaxis (PrEP) in preventing human immunodeficiency virus (HIV) acquisition. Little is known about adherence to the regimen, sexual practices, and overall effectiveness when PrEP is implemented in clinics that treat sexually transmitted infections (STIs) and community-based clinics serving men who have sex with men (MSM).ObjectiveTo assess PrEP adherence, sexual behaviors, and the incidence of STIs and HIV infection in a cohort of MSM and transgender women initiating PrEP in the United States.Design, setting, and participantsDemonstration project conducted from October 1, 2012, through February 10, 2015 (last date of follow-up), among 557 MSM and transgender women in 2 STI clinics in San Francisco, California, and Miami, Florida, and a community health center in Washington, DC. Data were analyzed from December 18, 2014, through August 8, 2015.InterventionsA combination of daily, oral tenofovir disoproxil fumarate and emtricitabine was provided free of charge for 48 weeks. All participants received HIV testing, brief client-centered counseling, and clinical monitoring.Main outcomes and measuresConcentrations of tenofovir diphosphate in dried blood spot samples, self-reported numbers of anal sex partners and episodes of condomless receptive anal sex, and incidence of STI and HIV acquisition.ResultsOverall, 557 participants initiated PrEP, and 437 of these (78.5%) were retained through 48 weeks. Based on the findings from the 294 participants who underwent measurement of tenofovir diphosphate levels, 80.0% to 85.6% had protective levels (consistent with ≥4 doses/wk) at follow-up visits. African American participants (56.8% of visits; P = .003) and those from the Miami site (65.1% of visits; P < .001) were less likely to have protective levels, whereas those with stable housing (86.8%; P = .02) and those reporting at least 2 condomless anal sex partners in the past 3 months (88.6%; P = .01) were more likely to have protective levels. The mean number of anal sex partners declined during follow-up from 10.9 to 9.3, whereas the proportion engaging in condomless receptive anal sex remained stable at 65.5% to 65.6%. Overall STI incidence was high (90 per 100 person-years) but did not increase over time. Two individuals became HIV infected during follow-up (HIV incidence, 0.43 [95% CI, 0.05-1.54] infections per 100 person-years); both had tenofovir diphosphate levels consistent with fewer than 2 doses/wk at seroconversion.Conclusions and relevanceThe incidence of HIV acquisition was extremely low despite a high incidence of STIs in a large US PrEP demonstration project. Adherence was higher among those participants who reported more risk behaviors. Interventions that address racial and geographic disparities and housing instability may increase the impact of PrEP
Regional brain differences in the effect of distraction during the delay interval of a working memory task
Working memory (WM) comprises operations whose coordinated action contributes to our ability to maintain focus on goal-relevant information in the presence of distraction. The present study investigated the nature of distraction upon the neural correlates of WM maintenance operations by presenting task-irrelevant distracters during the interval between the memoranda and probes of a delayed-response WM task. The study used a region of interest (ROIs) approach to investigate the role of anterior (e.g., lateral and medial prefrontal cortex - PFC) and posterior (e.g., parietal and fusiform cortices) brain regions that have been previously associated with WM operations. Behavioral results showed that distracters that were confusable with the memorandum impaired WM performance, compared to either the presence of non-confusable distracters or to the absence of distracters. These different levels of distraction led to differences in the regional patterns of delay interval activity measured with event-related functional magnetic resonance imaging (fMRI). In the anterior ROIs, dorsolateral PFC activation was associated with WM encoding and maintenance, and in maintaining a preparatory state, and ventrolateral PFC activation was associated with the inhibition of distraction. In the posterior ROIs, activation of the posterior parietal and fusiform cortices was associated with WM and perceptual processing, respectively. These findings provide novel evidence concerning the neural systems mediating the cognitive and behavioral responses during distraction, and places frontal cortex at the top of the hierarchy of the neural systems responsible for cognitive control
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Preexposure Prophylaxis for HIV Infection Integrated With Municipal- and Community-Based Sexual Health Services
ImportanceSeveral randomized clinical trials have demonstrated the efficacy of preexposure prophylaxis (PrEP) in preventing human immunodeficiency virus (HIV) acquisition. Little is known about adherence to the regimen, sexual practices, and overall effectiveness when PrEP is implemented in clinics that treat sexually transmitted infections (STIs) and community-based clinics serving men who have sex with men (MSM).ObjectiveTo assess PrEP adherence, sexual behaviors, and the incidence of STIs and HIV infection in a cohort of MSM and transgender women initiating PrEP in the United States.Design, setting, and participantsDemonstration project conducted from October 1, 2012, through February 10, 2015 (last date of follow-up), among 557 MSM and transgender women in 2 STI clinics in San Francisco, California, and Miami, Florida, and a community health center in Washington, DC. Data were analyzed from December 18, 2014, through August 8, 2015.InterventionsA combination of daily, oral tenofovir disoproxil fumarate and emtricitabine was provided free of charge for 48 weeks. All participants received HIV testing, brief client-centered counseling, and clinical monitoring.Main outcomes and measuresConcentrations of tenofovir diphosphate in dried blood spot samples, self-reported numbers of anal sex partners and episodes of condomless receptive anal sex, and incidence of STI and HIV acquisition.ResultsOverall, 557 participants initiated PrEP, and 437 of these (78.5%) were retained through 48 weeks. Based on the findings from the 294 participants who underwent measurement of tenofovir diphosphate levels, 80.0% to 85.6% had protective levels (consistent with ≥4 doses/wk) at follow-up visits. African American participants (56.8% of visits; P = .003) and those from the Miami site (65.1% of visits; P < .001) were less likely to have protective levels, whereas those with stable housing (86.8%; P = .02) and those reporting at least 2 condomless anal sex partners in the past 3 months (88.6%; P = .01) were more likely to have protective levels. The mean number of anal sex partners declined during follow-up from 10.9 to 9.3, whereas the proportion engaging in condomless receptive anal sex remained stable at 65.5% to 65.6%. Overall STI incidence was high (90 per 100 person-years) but did not increase over time. Two individuals became HIV infected during follow-up (HIV incidence, 0.43 [95% CI, 0.05-1.54] infections per 100 person-years); both had tenofovir diphosphate levels consistent with fewer than 2 doses/wk at seroconversion.Conclusions and relevanceThe incidence of HIV acquisition was extremely low despite a high incidence of STIs in a large US PrEP demonstration project. Adherence was higher among those participants who reported more risk behaviors. Interventions that address racial and geographic disparities and housing instability may increase the impact of PrEP
Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men.
Background: Antiretroviral chemoprophylaxis before exposure is a promising approach for the prevention of human immunodeficiency virus (HIV) acquisition. Methods: We randomly assigned 2499 HIV-seronegative men or transgender women who have sex with men to receive a combination of two oral antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (FTC-TDF), or placebo once daily. All subjects received HIV testing, risk-reduction counseling, condoms, and management of sexually transmitted infections. Results: The study subjects were followed for 3324 person-years (median, 1.2 years; maximum, 2.8 years). Of these subjects, 10 were found to have been infected with HIV at enrollment, and 100 became infected during follow-up (36 in the FTC-TDF group and 64 in the placebo group), indicating a 44% reduction in the incidence of HIV (95% confidence interval, 15 to 63; P=0.005). In the FTC-TDF group, the study drug was detected in 22 of 43 of seronegative subjects (51%) and in 3 of 34 HIV-infected subjects (9%) (P<0.001). Nausea was reported more frequently during the first 4 weeks in the FTC-TDF group than in the placebo group (P<0.001). The two groups had similar rates of serious adverse events (P=0.57). Conclusions: Oral FTC-TDF provided protection against the acquisition of HIV infection among the subjects. Detectable blood levels strongly correlated with the prophylactic effect. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT00458393.) N Engl J Med 2010;363:2587-99.Division of Acquired Immunodeficiency Syndrome (DAIDS), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH)[UO1 AI64002]Bill and Melinda Gates FoundationDAIDS[UO1 AI84735]DAIDS[AI062333]National Institutes of Health (NIH)[UL1 RR024131]GileadMerckBristol-Myers Squib