Increasing extreme climatic events threaten the functioning of terrestrial ecosystems. Because soil microbes govern key biogeochemical processes, understanding their response to climate extremes is crucial in predicting the consequences for ecosystem functioning. Here we subjected soils from 30 grasslands across Europe to four contrasting extreme climatic events under common controlled conditions (drought, flood, freezing and heat), and compared the response of soil microbial communities and their functioning with those of undisturbed soils.
View Article and Find Full Text PDFBackground: Both legal and extra-legal factors influence judicial and non-judicial opinions about persons who use drugs. Yet, how the locational setting of drug transactions influences public perceptions of drug control policies remains understudied. In particular, the public's view of drug exchanges on the dark web could directly and indirectly influence drug policy, legal decision making, and spending decisions.
View Article and Find Full Text PDFGram-negative bacteria are intrinsically resistant to a plethora of antibiotics that effectively inhibit the growth of Gram-positive bacteria. The intrinsic resistance of Gram-negative bacteria to classes of antibiotics, including rifamycins, aminocoumarins, macrolides, glycopeptides, and oxazolidinones, has largely been attributed to their lack of accumulation within cells due to poor permeability across the outer membrane, susceptibility to efflux pumps, or a combination of these factors. Due to the difficulty in discovering antibiotics that can bypass these barriers, finding targets and compounds that increase the activity of these ineffective antibiotics against Gram-negative bacteria has the potential to expand the antibiotic spectrum.
View Article and Find Full Text PDFSpecies distributions are closely associated with moisture availability, but the underlying mechanisms remain unresolved. Drought relations are especially important for plants such as C grasses that dominate seasonally dry ecosystems. Here, we test the hypothesis that C grass species sampled across global precipitation gradients show variation in survival under drought that can be explained by their traits.
View Article and Find Full Text PDFThis article develops a dynamic extension of the classic model of cybersecurity investment formulated by Gordon and Loeb. In this dynamic model, results are influenced by the rate at which cybersecurity assets depreciate and the rate of return on investment. Depreciation costs are lower in the dynamic model than is implicitly assumed in the classic model, while the rate-of-return threshold is higher.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2020
The Tor anonymity network allows users to protect their privacy and circumvent censorship restrictions but also shields those distributing child abuse content, selling or buying illicit drugs, or sharing malware online. Using data collected from Tor entry nodes, we provide an estimation of the proportion of Tor network users that likely employ the network in putatively good or bad ways. Overall, on an average country/day, ∼6.
View Article and Find Full Text PDFPlant populations persist under recurrent fire via resprouting from surviving tissues (resprouters) or seedling recruitment (seeders). Woody species are inherently slow maturing, meaning that seeders are confined to infrequent fire regimes. However, for grasses, which mature faster, the relationships between persistence strategy and fire regime remain unknown.
View Article and Find Full Text PDFNew cybersecurity technologies, such as commercial antivirus software (AV), sometimes fail to deliver on their promised benefits. This article develops and tests a revised version of risk homeostasis theory, which suggests that new cybersecurity technologies can sometimes have ill effects on security outcomes in the short run and little-to-no effect over the long run. It tests the preliminary plausibility of four predictions from the revised risk homeostasis theory using new survey data from 1,072 respondents.
View Article and Find Full Text PDFInt J Drug Policy
February 2020
Background: Cannabis is one of the most commonly sold drugs on cryptomarkets. Because of the anonymity-granting functions of Tor, no study has traced the within-country effect of the Dark Web on cannabis consumption patterns. This article uses a big data research design to examine the association between revealed interest in the Dark Web and self-reported cannabis use within US states from 2011 when Silk Road launched to 2015 when Operation Onymous shuttered nine markets.
View Article and Find Full Text PDFIntroduction And Aims: A growing body of evidence suggests e-cigarette use increases the risk of conventional cigarette use. Assessing the factors associated with intentions to use e-cigarettes can inform programs designed to minimise uptake, potentially assisting in preventing a new population of smokers. This study developed and tested a model assessing the importance of various factors that may be associated with intentions to use e-cigarettes among young adults who have never used e-cigarettes or tobacco cigarettes.
View Article and Find Full Text PDFBackground: Calls have been made to relax current Australian regulations related to e-cigarettes to increase the accessibility of the devices for smoking cessation purposes. However, e-cigarettes have been found to increase risk of initiation of conventional cigarette smoking, especially among young adults. To assist in guiding the development of policy in Australia, the present study examined whether e-cigarette use among Australian young adults who have never smoked a tobacco cigarette is associated with susceptibility to future tobacco cigarette use.
View Article and Find Full Text PDFDNA replication and repair enzyme Flap Endonuclease 1 (FEN1) is vital for genome integrity, and FEN1 mutations arise in multiple cancers. FEN1 precisely cleaves single-stranded (ss) 5'-flaps one nucleotide into duplex (ds) DNA. Yet, how FEN1 selects for but does not incise the ss 5'-flap was enigmatic.
View Article and Find Full Text PDFBackground: In the UK, initiating then discontinuing breastfeeding before two weeks post-partum is common. The aim of this longitudinal qualitative study was to explore which psychosocial factors may influence discontinuation.
Methods: A sample of 10 pregnant women intending to breastfeed were recruited.
Cancer cell 'invasiveness' is one of the main driving forces in cancer metastasis, and assays that quantify this key attribute of cancer cells are crucial in cancer metastasis research. The research goal of many laboratories is to elucidate the signaling pathways and effectors that are responsible for cancer cell invasion, but many of these experiments rely on in vitro methods that do not specifically simulate individual steps of the metastatic cascade. Cancer cell extravasation is arguably the most important example of invasion in the metastatic cascade, whereby a single cancer cell undergoes transendothelial migration, forming invasive processes known as invadopodia to mediate translocation of the tumor cell from the vessel lumen into tissue in vivo.
View Article and Find Full Text PDFThe prototypical 5'-nuclease, flap endonuclease-1 (FEN1), catalyzes the essential removal of single-stranded flaps during DNA replication and repair. FEN1 hydrolyzes a specific phosphodiester bond one nucleotide into double-stranded DNA. This specificity arises from double nucleotide unpairing that places the scissile phosphate diester on active site divalent metal ions.
View Article and Find Full Text PDFNucleic Acids Res
November 2013
The structure- and strand-specific phosphodiesterase flap endonuclease-1 (FEN1), the prototypical 5'-nuclease, catalyzes the essential removal of 5'-single-stranded flaps during replication and repair. FEN1 achieves this by selectively catalyzing hydrolysis one nucleotide into the duplex region of substrates, always targeting the 5'-strand. This specificity is proposed to arise by unpairing the 5'-end of duplex to permit the scissile phosphate diester to contact catalytic divalent metal ions.
View Article and Find Full Text PDFObjectives: To identify the number and current location of all children receiving long-term ventilation (LTV) in the UK, and to establish their underlying diagnoses and ventilatory requirements.
Design: Single time-point census completed by members of the UK LTV working party using an electronic-based questionnaire
Subjects: All children in the UK at home or in hospital who, when medically stable, continue to need a mechanical aid for breathing following a failure to wean beyond a 3-month period.
Results: 933 children under the age of 17 years in 30 regional centres were identified as receiving LTV.
Background And Aims: Clinical adrenal insufficiency has been reported with doses of inhaled fluticasone proprionate (FP) > 400 microg/day, the maximum dose licensed for use in children with asthma. Following two cases of serious adrenal insufficiency (one fatal) attributed to FP, adrenal function was evaluated in children receiving FP outwith the licensed dose.
Methods: Children recorded as prescribed FP > or = 500 microg/day were invited to attend for assessment.
A recent paper has highlighted the differences in the respiratory management offered to infants with type 1 spinal muscular atrophy (SMA-1). Current views appear polarised between those who would offer nothing, to those who would proceed as far even as tracheostomy and long term invasive ventilation for these infants. Here we offer a personal view, as a possible template for managing a vexed and emotional problem.
View Article and Find Full Text PDFObjective: Insulin-like growth factor-I (IGF-I) and insulin are important vasoactive peptides but little is known about their effects in hypertension.
Design: We compared the responses of stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rat aortae to IGF-I and insulin.
Methods: Aortae were removed from WKY and SHRSP, cut into 2-3 mm rings, and contractile responses to phenylephrine and endothelin-1 studied in organ chambers in the presence of vehicle, IGF-I (0.