711 research outputs found

    Social structure and underwater behavior of harbor seals in southern Monterey Bay, California

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    To understand harbor seal social and mating strategies, I examined site fidelity, seasonal abundance and distribution, herd integrity, and underwater behavior of individual harbor seals in southern Monterey Bay. Individual harbor seals (n = 444) were identified by natural markings and represented greater than 80% of an estimated 520 seals within this community. Year to year fidelity of individual harbor seals to southern Monterey Bay coastline was 84% (n = 388), and long-term associations (>2 yrs) among individuals were common (>40%). Consistent with these long-term associations, harbor seals were highly social underwater throughout the year. Underwater social behavior included three primary types: (1) visual and acoustic displays, such as vocalizing, surface splashing, and bubble-blowing; (2) playful or agonistic social behavior such as rolling, mounting, attending, and biting; and (3) signal gestures such as head-thrusting, fore-flipper scratch~ng, and growling. Frequency of these types of behavior was related to seal age, gender, season, and resource availability. Underwater behavior had a variety of functions, including promotion of learning and social development, reduction of aggression and preservation of social bonds by maintaining social hierarchy, and facilitation of mate selection during breeding season. Social behavior among adult males was significantly correlated with vocalization characteristics (r = 0.99, X2 = 37.7, p = 0.00087), indicating that seals may assess their competition based on underwater vocalization displays and adopt individual strategies for attracting females during breeding season based on social status. Individual mating strategies may include defending underwater territories, using scramble tactics, and developing social alliances. (PDF contains 105 pages

    “It's the one thing that makes my life tick”:security perspectives of the smartphone era

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    As smartphones overtake personal computers as the device of choice for internet access and everyday digital tasks, cybersecurity becomes a pressing issue for the platform. Research has found that smartphone users appear to act less securely than they would on a PC, but the reasons for this are unclear. The technology, the threats, and the role of smartphones have all developed in recent years, and this paper examines what smartphone security looks like to users in the 2020s. We interviewed 27 smartphone users about their security attitudes and behaviours. We find that users place great emphasis on, and take responsibility for, the physical security of their device, but minimise their responsibility for dealing with digital threats. We observe key contextual factors that influence how users protect their smartphones. The increasing monetary cost of smartphones and users’ functional reliance on them, causes participants to be highly concerned with protecting the physical safety and integrity of their devices. However, users appear to have a high level of trust in apps, based on the vetting processes of official app stores, yet they are still vulnerable to abuse from malicious/unnecessary permissions, and exhibit poor security habits when accessing illegitimate, pirated media outside of their smartphone's app store

    Better the devil you know:using lost-smartphone scenarios to explore user perceptions of unauthorised access

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    Smartphones are a central part of modern life and contain vast amounts of personal and professional data as well as access to sensitive features such as banking and financial apps. As such protecting our smartphones from unauthorised access is of great importance, and users prioritise this over protecting their devices against digital security threats. Previous research has explored user experiences of unauthorised access to their smartphone - though the vast majority of these cases involve an attacker who is known to the user and knows an unlock code for the device. We presented 374 participants with a scenario concerning the loss of their smartphone in a public place. Participants were allocated to one of 3 scenario groups where a different unknown individual with malicious intentions finds the device and attempts to gain access to its contents. After exposure, we ask participants to envision a case where someone they know has a similar opportunity to attempt to gain access to their smartphone. We compare these instances with respect to differences in the motivations of the attacker, their skills and their knowledge of the user. We find that participants underestimate how commonly people who know them may be able to guess their PIN and overestimate the extent to which smartphones can be g'hacked into'. We discuss how concerns over the severity of an attack may cloud perceptions of its likelihood of success, potentially leading users to underestimate the likelihood of unauthorised access occurring from known attackers who can utilize personal knowledge to guess unlock codes.</p

    Gravitational geomicrobiology: biofilms and their mineral interactions under terrestrial and altered gravity

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    Experiments with microbial biofilms in microgravity and simulated microgravity have revealed altered growth kinetics, but geomicrobial biofilms have not yet been studied in low gravity environments. No characterisation of biofilms, geomicrobial or otherwise, have been conducted at hypergravity. This thesis explores factors affecting microbe-mineral interactions under terrestrial conditions, lays the groundwork for a scheduled microgravity experiment, and provides the first data on biofilms grown at hypergravity. As a first step in understanding microbe-mineral interactions in altered gravity environments, experiments were undertaken to identify factors that constrain attachment in a terrestrial environment. The model organism Sphingomonas desiccabilis and basaltic rock from Iceland were selected, and the minerals that make up the basalt were identified and procured in their pure form. The relative significance of physical factors such as hydrophobicity, surface charge, porosity and nutritional value were examined in relationship to the success with which biofilms colonised the mineral surfaces. Growth was measured by the quantity of biofilm biomass after a ifxed time period, using Crystal Violet stain, in order to draw conclusions about the most influential physical conditions on biofilm attachment to a substrate. It was found that mineral attachment is influenced more by porosity and nutritional value than by hydrophobicity or surface charge. To explore how reduced gravity affects biofilm formation and weathering rates, a European Space Agency experiment, BioRock, is underway. Samples of basalt, with monocultures of three different organisms, will be sent to the International Space Station in 2019 for long-term exposure to Martian and micro-gravity. Research testing proof of concepts, material compatibility, and experimental procedure and equipment is described. Confocal laser scanning microscopy (CLSM) was used to image the biofilms, and inductively coupled plasma mass spectroscopy (ICP-MS) experiments were conducted to compare biotic and abiotic elemental release rates from basalt. Both of these methods will be employed for post-flight analysis of BioRock. Preliminary terrestrial ICP-MS experiments indicated that rare Earth elements (REEs) showed the most reliable reflection of leaching patterns overall, as a consequence of their high molecular weight and low volatility during the ashing procedure. To fully understand gravity's effect on microbiological processes it is important to investigate what occurs when its influences are removed, but also to establish what occurs when extra gravitational force is applied. Using simulated hypergravity, achieved through hyper-acceleration on a geotechnical centrifuge, the effects of 10 x g on biofilm development and the leaching of basalt were investigated. As this was the first time that biofilms had been studied under hypergravity, additional substrates were included with the basalt, to enable characterisation of the more general response of biofilms to hypergravity. In contrast to previous experiments conducted on planktonic bacteria, which found decreased population sizes, the biofilms grown at 10 x g showed greater biomass than the 1 x g samples. ICP-MS showed no difference in the average weathering rates, but greater variability in the higher gravity samples. The data collected here advances our understanding of microbial interactions with geologically important substrates, with implications for an ISS microgravity experiment and future human space exploration. It also presents new intelligence on the previously unstudied effects of hypergravity on biofilms and rock weathering

    Methods of Association for Genome Data with Rare Variants and a Multinomial Response

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    A rare variant is a Single Nucleotide Polymorphism (SNP) with a minor allele frequency (MAF) of 5% or less. Approximately 60% of human SNPs are rare variants. New rapid genotyping technologies now make it possible to efficiently survey these rare variants. Many new statistical methods are being developed to analyze the associations between rare variants and phenotypes. Current methods have focused on dichotomous phenotypes such as case/control status or quantitative phenotypes such as weight or cholesterol level. Rare variant association methods for multinomial phenotypes, or categorical outcomes with more than two possibilities, have not been adequately addressed. The purpose of this study is to develop new methods of rare variant association analysis for a multinomial phenotype. Several new methods are proposed and evaluated using simulations. Simulations showed that two of the proposed methods are viable for rare variant association analysis with multinomial phenotypes. These methods have the correct or conservative Type I error rate and reasonable power for large samples with a moderate heritability. The viable methods are applied to resequencing data from the Dallas Heart Study. One of the methods detected an association between a categorized plasma triglyceride level and the ANGPTL3 and ANGPTL4 genes.Statistic

    Data resource profile : the Scottish national prescribing information system (PIS)

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    Data Resource Basics: The Prescribing Information System (PIS) covers the prescribed,dispensed and reimbursed prescriptions in community pharmacies from the 5.3 million residents in Scotland. Summary information is available from 1993 and at an individual level from 2009 to the present. Data Collected: The raw data are generated by three data sources: ePrescribed -generated by GPs messages, eDispensed –generated by messages from community pharmacies and Reimbursed messages from scanned paper prescriptions dispensed in the community pharmacies. The four main categories of data collected are: (1) Patient-specific, (2) Prescriber, (3) Dispenser and (4) Drug-specific. PIS data can be linked via a unique identifier to other national databases, including hospital records, maternal and neonatal, the Scottish Cancer Registry and mortality records. The catalogue of databases is available in www.ndc.scot.nhs.uk . Subject to approval of the data controllers other external datasets can also be linked. Data Resource Use: PIS has been used to describe the utilisation of several groups of drugs;factors influencing prescribing and evaluation of interventions to improve it; generation of polypharmacy guidelines; risk of side effects; monitoring of antibiotic use and generation of policy recommendations; associations between community prescription of antimicrobials and deprivation or infection; evaluation of prescription fee abolition; clinical effectiveness, safety and health technology assessment of drugs approved in the last decade. Reasons to be cautious: PIS does not capture information about diagnosis or indication for treatment, over the counter medicines, medicines administered during inpatient hospital stays, upon discharge for short term use, outpatient supplies or some specialist drugs for chronic use. Drug data is currently coded according to the British National Formulary. For longitudinal studies, patient level data is available from 2009 and the frequency of data collection from the three sources is different. Collaboration and data access: PIS data are available upon request to the electronic Data Research and Innovation Service ([email protected]) and project approval by the Public Benefit and Privacy Panel. Funding and competing interests: This dataset is funded from the public monies available to the NHS. Current work to develop an improved PIS research ready analysis platform and this study is supported by the Farr Institute @ Scotland and its 10-funder consortium. The authors declare no conflict of interest

    Synaptotagmin 1 oligomers clamp and regulate different modes of neurotransmitter release

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    Release of neurotransmitters relies on submillisecond coupling of synaptic vesicle fusion to the triggering signal: AP-evoked presynaptic Ca2+ influx. The key player that controls exocytosis of the synaptic vesicle is the Ca2+ sensor synaptotagmin 1 (Syt1). While the Ca2+ activation of Syt1 has been extensively characterized, how Syt1 reversibly clamps vesicular fusion remains enigmatic. Here, using a targeted mutation combined with fluorescence imaging and electrophysiology, we show that the structural feature of Syt1 to self-oligomerize provides the molecular basis for clamping of spontaneous and asynchronous release but is not required for triggering of synchronous release. Our findings propose a mechanistic model that explains how Syt1 oligomers regulate different modes of transmitter release in neuronal synapses

    Writing Activity Objectives for Caring for and Educating Infants and Toddlers

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