276 research outputs found

    Dependence of ombrotrophic peat nitrogen on phosphorus and climate

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    Nitrogen (N) is a key, possibly limiting, nutrient in ombrotrophic peat ecosystems, and enrichment by pollutant N in atmospheric deposition (Ndep, g m-2 a-1) is of concern with regard to peatland damage. We collated data on the N content of surface (depth ≤ 25 cm, mean 15 cm) ombrotrophic peat (Nsp) for 215 sites in the UK and 62 other sites around the world, including boreal, temperate and tropical locations (wider global data), and found Nsp to range from 0.5 % to 4%. We examined the dependences of Nsp on surface peat phosphorus (P) content (Psp), mean annual precipitation (MAP), mean annual temperature (MAT) and Ndep. Linear regression on individual independent variables showed highly significant (p < 0.001) correlations of Nsp with Psp (r2 = 0.23) and MAP (r2 = 0.14), and significant (p < 0.01) but weaker correlations with MAT (r2 = 0.03) and Ndep (r2 = 0.03). A multiple regression model using log-transformed values explained 36% of the variance of the UK data, 84% of the variance of the wider global data, and 47% of the variance of the combined data, all with high significance (p < 0.001). In all three cases, most of the variance was explained by Psp and MAP, but in view of a positive correlation between MAP and MAT for many of the sites, a role for MAT in controlling Nsp cannot be ruled out. There is little evidence for an effect of Ndep on Nsp. The results point to a key role of P in N fixation, and thereby C fixation, in ombrotrophic peats

    Third sector internships Scotland: final report

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    Third Sector Internships Scotland helped students gain paid work experience in the Third Sector. This five-year programme, part of the Scottish Funding Council’s Learning to Work 2 initiative, was open to students from all Scottish universities

    Third sector internships Scotland: final report

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    Third Sector Internships Scotland helped students gain paid work experience in the Third Sector. This five-year programme, part of the Scottish Funding Council’s Learning to Work 2 initiative, was open to students from all Scottish universities

    Vaccine intention and hesitancy among Australian women who are currently pregnant or have recently given birth : the Birth in the Time of COVID-19 (BITTOC) national online survey

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    Objective To examine the prevalence of COVID-19 vaccination, and factors associated with vaccination intention and hesitancy in pregnant and postnatal women in Australia. Design and setting A national online survey was conducted over 6 months between 31 August 2021 and 1 March 2022 and responses to vaccination status were categorised as: 'vaccinated', 'vaccine intended' and 'vaccine hesitant'. The data were weighted to reflect the proportion of women of reproductive age. Potential confounding variables were examined using multinomial logistic regression analyses, and all comparisons were made against vaccinated pregnant and postnatal women. Participants 2140 women responded to the survey (838 pregnant; 1302 recently post partum). Results Amongst pregnant women, 586 (69.9%) were vaccinated, 166 (19.8%) indicated intention and 86 (10.3%) were hesitant. In postnatal women, this was 1060 (81.4%), 143 (11.0%) and 99 (7.6%), respectively. Only 52 (6.2%) of pregnant women stated never wanting a COVID-19 vaccine. Vaccine hesitancy increased over time, and for pregnant women was associated with: living in a state other than New South Wales (NSW) (Adjusted Relative Risk (ARR) 2.77, 95%CI: 1.68-4.56 for vaccine intention and ARR=3.31, 95%CI: 1.52-7.20 for vaccine hesitancy), younger age <30 years, not having a university education, income <80K AUD, gestation <28 weeks, having no pregnancy risk factors, and being less satisfied with life (ARR=2.20, 95%CI: 1.04-4.65 for vaccine intention and ARR=2.53, 95%CI: 1.02-6.25 for vaccine hesitancy). For postnatal women: living in a state other than NSW or Victoria, income <80K AUD and having private obstetric care (ARR=2.06, 95%CI: 1.23-3.46) were significantly associated with vaccine hesitancy. Conclusions Around 1 in 10 pregnant women and just over 1 in 13 postnatal women reported vaccine hesitancy in this Australian survey, and hesitancy was higher in the latter 3-month period. Tailored messages to younger mothers and those from lower-middle socioeconomic groups, alongside advice from midwives and obstetricians, could help to reduce hesitancy among pregnant and postnatal women. Financial incentives may help to facilitate COVID-19 vaccine uptake. A real-time surveillance system and additional pregnancy fields added to the Australian immunisation register would support the safety monitoring of multiple vaccines in pregnancy and may build confidence

    Out of sight but not out of harm’s way: human disturbance reduces reproductive success of a cavity-nesting seabird

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    While negative effects of human disturbance on animals living above the ground have been widely reported, few studies have considered effects on animals occupying cavities or burrows underground. It is generally assumed that, in the absence of direct visual contact, such species are less vulnerable to disturbance. Seabird colonies can support large populations of burrow- and cavity-nesting species and attract increasing numbers of tourists. We investigated the potential effects of recreational disturbance on the reproductive behaviour of the European storm petrel &lt;i&gt;Hydrobates pelagicus&lt;/i&gt;, a nocturnally-active cavity-nesting seabird. Reproductive phenology and outcome of nests subject to high and low levels of visitor pressure were recorded in two consecutive years. Hatching success did not differ between disturbance levels, but overall nestling mortality was significantly higher in areas exposed to high visitor pressure. Although visitor numbers were consistent throughout the season, the magnitude and rate of a seasonal decline in productivity were significantly greater in nests subject to high disturbance. This study presents good evidence that, even when humans do not pose a direct mortality risk, animals may perceive them as a predation risk. This has implications for the conservation and management of a diverse range of burrow- and cavity-dwelling animals. Despite this reduction in individual fitness, overall colony productivity was reduced by ≤1.6% compared with that expected in the absence of visitors. While the colony-level consequences at the site in question may be considered minor, conservation managers must evaluate the trade-off between potential costs and benefits of public access on a site- and species-specific basis

    Perinatal depression in Australian women during the COVID-19 pandemic : the birth in the time of COVID-19 (BITTOC) study

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    The COVID-19 pandemic has impacted perinatal mental health globally. We determined the maternal factors and pandemic-related experiences associated with clinically significant perinatal (pregnant and post-partum) depressive symptoms in Australian women. Participants (n = 2638; pregnant n = 1219, postnatal n = 1419) completed an online survey (August 2020 through February 2021) and self-reported on depression, social support, and COVID-19 related experiences. We found elevated depressive symptoms amongst 26.5% (pregnant) and 19% (postnatal) women. Multiple logistic regression analyses showed higher likelihood of elevated depression associated with residence in Victoria, lower education, past/current mental health problems, greater non-pandemic prenatal stress, age ≥ 35 years (pregnant women) and existing physical health issues or disability in self or others (postnatal women). Greater family stress/discord and lower social support (friends) was associated with higher odds of elevated perinatal depression, while lower social support (family) was significantly associated with elevated depressive symptoms in pregnant women. Greater depression was associated with social distancing, pandemic-related news exposure and changes to prenatal care (pregnant women). Single postnatal women showed lower odds of elevated depression than partnered women. Our findings underscore the importance of universal screening for depression and targeted support during a pandemic for perinatal women displaying vulnerability factors

    A key role for peroxynitrite-mediated inhibition of cardiac ERG (Kv11.1) K+ channels in carbon monoxide–induced proarrhythmic early afterdepolarizations

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    Exposure to carbon monoxide (CO) causes early afterdepolarization arrhythmias. Previous studies in rats indicated arrhythmias arose due to augmentation of the late Na+ current. The purpose of the present study was to examine the basis of CO-induced arrhythmias in guinea pig myocytes in which action potentials more closely resemble those of human myocytes. Whole-cell current- and voltage-clamp recordings were made from isolated guinea pig myocytes and also from HEK293 cells expressing wild-type or a C723S mutant form of Kv11.1 (ERG). We also monitored formation of peroxynitrite (ONOO-) in HEK293 cells fluorimetrically. CO, applied as the CO releasing molecule, CORM-2, prolonged action potentials and induced early after-depolarizations (EADs) in guinea pig myocytes. In HEK293 cells CO inhibited wild-type but not C723S mutant Kv11.1 K+ currents. Inhibition was prevented by an antioxidant, mitochondrial inhibitors or inhibition of nitric oxide formation. CO also raised ONOO- levels, an effect reversed by the ONOO- scavenger, FeTPPS which also prevented CO inhibition of Kv11.1 currents, and abolished the effects of CO on Kv11.1 tail currents and action potentials in guinea pig myocytes. Our data suggest that CO induces arrhythmias in guinea pig cardiac myocytes via ONOO--mediated inhibition of Kv11.1 K+ channel

    STAT5 activation promotes progression and chemotherapy-resistance in early T-cell precursor acute lymphoblastic leukemia

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    IL-7 supports the growth and chemoresistance of T-cell acute lymphoblastic leukemia (T-ALL), particularly the early T-cell precursor subtype (ETP-ALL), which frequently has activating mutations of IL-7 signaling. STAT5 is an attractive therapeutic target because it is almost universally activated in ETP-ALL, even in the absence of mutations of upstream activators such as the IL-7R, JAK and FLT3. To examine the role of activated STAT5 in ETP-ALL, we have used a Lmo2-transgenic (Lmo2Tg) mouse model in which we can monitor chemoresistant pre-leukemia (pre-LSCs) and leukemia stem cells (LSCs) that drive T-ALL development and relapse following chemotherapy. Using IL-7R-deficient Lmo2Tg mice, we show that IL-7 signaling was not required for the formation of pre-LSCs but essential for their expansion and clonal evolution into LSCs to generate T-ALL. Activated STAT5B was sufficient for the development of T-ALL in IL-7R; Lmo2Tg mice, indicating that inhibition of STAT5 is required to block the supportive signals provided by IL-7. To further understand the role of activated STAT5 in LSCs of ETP-ALL, we developed a new transgenic mouse that enables T-cell specific and doxycycline-inducible expression of the constitutively activated STAT5B1∗6 mutant. Expression of STAT5B1∗6 in T-cells had no effect alone but promoted expansion and chemoresistance of LSCs in Lmo2Tg mice. Pharmacologic inhibition of STAT5 with Pimozide induced differentiation and loss of LSCs, whilst enhancing response to chemotherapy. Furthermore, Pimozide significantly reduced leukemia burden in vivo and overcame chemoresistance of patient-derived ETP-ALL xenografts. Overall, our results demonstrate that STAT5 is an attractive therapeutic target for eradicating LSCs in ETP-ALL

    Imaging of Borrelia turicatae Producing the Green Fluorescent Protein Reveals Persistent Colonization of the Ornithodoros turicata Midgut and Salivary Glands from Nymphal Acquisition through Transmission

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    Relapsing fever (RF) spirochetes colonize and are transmitted to mammals primarily by Ornithodoros ticks, and little is known regarding the pathogen's life cycle in the vector. To further understand vector colonization and transmission of RF spirochetes, Borrelia turicatae expressing a green fluorescent protein (GFP) marker (B. turicatae-gfp) was generated. The transformants were evaluated during the tick-mammal infectious cycle, from the third nymphal instar to adult stage. B. turicatae-gfp remained viable for at least 18 months in starved fourth-stage nymphal ticks, and the studies indicated that spirochete populations persistently colonized the tick midgut and salivary glands. Our generation of B. turicatae-gfp also revealed that within the salivary glands, spirochetes are localized in the ducts and lumen of acini, and after tick feeding, the tissues remained populated with spirochetes. The B. turicatae-gfp generated in this study is an important tool to further understand and define the mechanisms of vector colonization and transmission. IMPORTANCE In order to interrupt the infectious cycle of tick-borne relapsing fever spirochetes, it is important to enhance our understanding of vector colonization and transmission. Toward this, we generated a strain of Borrelia turicatae that constitutively produced the green fluorescent protein, and we evaluated fluorescing spirochetes during the entire infectious cycle. We determined that the midgut and salivary glands of Ornithodoros turicata ticks maintain the pathogens throughout the vector's life cycle and remain colonized with the spirochetes for at least 18 months. We also determined that the tick's salivary glands were not depleted after a transmission blood feeding. These findings set the framework to further understand the mechanisms of midgut and salivary gland colonization

    30% land conservation and climate action reduces tropical extinction risk by more than 50%

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    Limiting climate change to less than 2°C is the focus of international policy under the climate convention (UNFCCC), and is essential to preventing extinctions, a focus of the Convention on Biological Diversity (CBD). The post‐2020 biodiversity framework drafted by the CBD proposes conserving 30% of both land and oceans by 2030. However, the combined impact on extinction risk of species from limiting climate change and increasing the extent of protected and conserved areas has not been assessed. Here we create conservation spatial plans to minimize extinction risk in the tropics using data on 289 219 species and modeling two future greenhouse gas concentration pathways (RCP2.6 and 8.5) while varying the extent of terrestrial protected land and conserved areas from <17% to 50%. We find that limiting climate change to 2°C and conserving 30% of terrestrial area could more than halve aggregate extinction risk compared with uncontrolled climate change and no increase in conserved area
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