5,341 research outputs found
Effects of Continued Selfing on Hymenolepis nano (Cestoda)
The effects of selfing on Hymenolepis nana were investigated by establishing single infections in mice, thus ensuring self-fertilization. Selfing appears to increase the frequency of cysticercoid abnormalities. The proportion of eggs developing into cysticercoids in Tribolium confusum appears to decrease with continued selfing. Similarly, the proportion of cysticercoids developing into adults in mice decreases with continued selfing. Selfing causes no observable variation in the size of either adults or cysticercoids, nor does it cause changes in the frequency of appearance of certain morphological variants of the adult worm. The variant of reversal of genital pore appears to cause sterility of those proglottids demonstrating this modification. No selfed strain could be maintained beyond the fifth selfed generation. A population of twenty adult worms, the number employed in control mice, does not appear sufficient to prevent the decrease in viability caused by selfing. Cercomer damage is of little importance in the infectivity of the cysticercoid
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Antecedents of support for social media content moderation and platform regulation: the role of presumed effects on self and others
This study examines support for regulation of and by platforms and provides insights into public perceptions of platform governance. While much of the public discourse surrounding platforms evolves at a policy level between think tanks, journalists, academics and political actors, little attention is paid to how people think about regulation of and by platforms. Through a representative survey study of US internet users (N = 1,022), we explore antecedents of support for social media content moderation by platforms, as well as for regulation of social media platforms by the government. We connect these findings to presumed effects on self (PME1) and others (PME3), concepts that lie at the core of third-person effect (TPE) and influence of presumed influence (IPI) scholarship. We identify third-person perceptions for social media content: Perceived negative effects are stronger for others than for oneself. A first-person perception operates on the platform level: The beneficial effects of social media platforms are perceived to be stronger for the self than for society. At the behavioral level, we identify age, education, opposition to censorship, and perceived negative effects of social media content on others (PME3) as significant predictors of support for content moderation. Concerning support for regulation of platforms by the government, we find significant effects of opposition to censorship, perceived intentional censorship, frequency of social media use, and trust in platforms. We argue that stakeholders involved in platform governance must take more seriously the attitudes of their constituents
A first direct measurement of the intergalactic medium temperature around a quasar at z=6
The thermal state of the intergalactic medium (IGM) provides an indirect
probe of both the HI and HeII reionisation epochs. Current constraints on the
IGM temperature from the Lya forest are restricted to the redshift range
2<z<4.5, limiting the ability to probe the thermal memory of HI reionisation
toward higher redshift. In this work, we present the first direct measurement
of the IGM temperature around a z=6 quasar by analysing the Doppler widths of
Lya absorption lines in the proximity zone of SDSS J0818+1722. We use a high
resolution (R= 40000) Keck/HIRES spectrum in combination with detailed
numerical modelling to obtain the temperature at mean density,
T_0=23600\pm^5000_6900K (\pm^9200_9300K) at 68 (95) per cent confidence
assuming a prior probability 13500K<T_0<38500 K following HI and HeII
reionisation. This enables us to place an upper limit on the redshift of HI
reionisation, z_H, within 33 comoving Mpc of SDSS J0818+1722. If the quasar
reionises the HeII in its vicinity, then in the limit of instantaneous
reionisation we infer z_H<9.0 (11.0) at 68 (95) per cent confidence assuming
photoheating is the dominant heat source and that HI reionisation is driven by
ionising sources with soft spectra, typical of population II stars. If the HI
and HeII in the IGM around SDSS J0818+1722 are instead reionised simultaneously
by a population of massive metal-free stars, characterised by very hard
ionising spectra, we obtain a tighter upper limit of z_H<8.4 (9.4). Initiating
reionisation at higher redshifts produces temperatures which are too low with
respect to our constraint unless the HI ionising sources or the quasar itself
have spectra significantly harder than typically assumed.Comment: 15 pages, 9 figures, accepted to MNRA
The adaptations of a quality of life questionnaire for routine use in clinical practice: the Chronic Respiratory Disease Questionnaire in Cystic Fibrosis.
Night optimised care technology for users needing assisted lifestyles
There is growing interest in the development of ambient assisted living services to increase the quality of life of the increasing proportion of the older population. We report on the Night Optimised Care Technology for UseRs Needing Assisted Lifestyles project, which provides specialised night time support to people at early stages of dementia. This article explains the technical infrastructure, the intelligent software behind the decision-making driving the system, the software development process followed, the interfaces used to interact with the user, and the findings and lessons of our user-centred approach
Participatory research to design a novel system to support the night-time needs of people with dementia; NOCTURNAL
Strategies to support people living with dementia are broad in scope, proposing both pharmacological and non-pharmacological interventions as part of the care pathway. Assistive technologies form part of this offering as both stand-alone devices to support particular tasks and the more complex offering of the “smart home” to underpin ambient assisted living. This paper presents a technology-based system, which expands on the smart home architecture, orientated to support people with daily living. The system, NOCTURNAL, was developed by working directly with people who had dementia, and their carers using qualitative research methods. The research focused primarily on the nighttime needs of people living with dementia in real home settings. Eight people with dementia had the final prototype system installed for a three month evaluation at home. Disturbed sleep patterns, night-time wandering were a focus of this research not only in terms of detection by commercially available technology but also exploring if automated music, light and visual personalized photographs would be soothing to participants during the hours of darkness. The NOCTURNAL platform and associated services was informed by strong user engagement of people with dementia and the service providers who care for them. NOCTURNAL emerged as a holistic service offering a personalised therapeutic aspect with interactive capabilities
Commercial Driver’s License (CDL) Workflow Study
Kentucky uses federally funded, time-limited (FFTL) employees to handle some of the administrative work necessary to meet federal compliance standards for commercial driver’s licenses (CDLs). The Federal Motor Carrier Safety Administration (FMCSA) has decided not to continue funding FFTLs for these purposes, meaning that states will have to find other ways to meet CDL program requirements and maintain compliance. Given the potential ramifications of losing federal transportation and enforcement funding due to lack of compliance with federal standards, it is imperative that state lawmakers act to ensure KYTC has the resources to carry out its mandated functions. The study delineates federal and state CDL requirements, current workflow processes, surveys practices in other states, reports on the status of CDL workflow automation and develops three alternative funding mechanisms to stabilize program workflow while developers gather requirements for web-based applications to increase workflow efficiency. It also recommends other changes that would benefit KYTC, particularly the staff responsible for CDL program administration and compliance
States’ Support of Non-Highway Modes of Transportation: Investigation and Synthesis
The objective of this study was to determine how Kentucky and other selected states support and assist non-highway transportation modes and to identify leading and innovative initiatives. For the purposes of this study, the non-highway modes are aviation, public transportation, rail, and waterways. This summary will briefly discuss the rationale, objectives, and methodology for this study. It also provides an overview of the outcomes of the study and the modal matrices
Insistence on sameness relates to increased covariance of gray matter structure in autism spectrum disorder.
BACKGROUND: Autism spectrum disorder (ASD) is characterized by atypical development of cortical and subcortical gray matter volume. Subcortical structural changes have been associated with restricted and repetitive behavior (RRB), a core component of ASD. Behavioral studies have identified insistence on sameness (IS) as a separable RRB dimension prominent in high-functioning ASD, though no simple brain-behavior relationship has emerged. Structural covariance, a measure of morphological coupling among brain regions using magnetic resonance imaging (MRI), has proven an informative measure of anatomical relationships in typical development and neurodevelopmental disorders. In this study, we use this measure to characterize the relationship between brain structure and IS.
METHODS: We quantified the structural covariance of cortical and subcortical gray matter volume in 55 individuals with high-functioning ASD using 3T MRI. We then related these structural metrics to individual IS scores, as assessed by the Repetitive Behavior Scale-Revised (RBS-R).
RESULTS: We found that increased coupling among subcortical regions and between subcortical and cortical regions related to greater IS symptom severity. Most pronounced, the striatum and amygdala participated in a plurality of identified relationships, indicating a central role for these structures in IS symptomatology. These structural associations were specific to IS and did not relate to any of the other RRB subcomponents measured by the RBS-R.
CONCLUSIONS: This study indicates that behavioral dimensions in ASD can relate to the coordination of development across multiple brain regions, which might be otherwise obscured using typical brain-behavior correlations. It also expands the structures traditionally related to RRB in ASD and provides neuroanatomical evidence supportive of IS as a separate RRB dimension.
TRIAL REGISTRATION: ClinicalTrials.gov NCT01031407
Quantitative BOLD imaging at 3T: Temporal changes in hepatocellular carcinoma and fibrosis following oxygen challenge.
PURPOSE: To evaluate the utility of oxygen challenge and report on temporal changes in blood oxygenation level-dependent (BOLD) contrast in normal liver, hepatocellular carcinoma (HCC) and background fibrosis. MATERIALS AND METHODS: Eleven volunteers (nine male and two female, mean age 33.5, range 27-41 years) and 10 patients (nine male and one female, mean age 68.9, range 56-87 years) with hepatocellular carcinoma on a background of diffuse liver disease were recruited. Imaging was performed on a 3T system using a multiphase, multiecho, fast gradient echo sequence. Oxygen was administered via a Hudson mask after 2 minutes of free-breathing. Paired t-tests were performed to determine if the mean pre- and post-O2 differences were statistically significant. RESULTS: In patients with liver fibrosis (n = 8) the change in T2* following O2 administration was elevated (0.88 ± 0.582 msec, range 0.03-1.69 msec) and the difference was significant (P = 0.004). The magnitude of the BOLD response in patients with HCC (n = 10) was larger, however the response was more variable (1.07 ± 1.458 msec, range -0.93-3.26 msec), and the difference was borderline significant (P = 0.046). The BOLD response in the volunteer cohort was not significant (P = 0.121, 0.59 ± 1.162 msec, range -0.81-2.44 msec). CONCLUSION: This work demonstrates that the BOLD response following oxygen challenge within cirrhotic liver is consistent with a breakdown in vascular autoregulatory mechanisms. Similarly, the elevated BOLD response within HCC is consistent with the abnormal capillary vasculature within tumors and the arterialization of the blood supply. Our results suggest that oxygen challenge may prove a viable BOLD contrast mechanism in the liver. J. Magn. Reson. Imaging 2016;44:739-744.This study was supported by the Addenbrooke’s Charitable Trust, Cambridge’s Experimental Cancer Medicine Centre and a NIHR comprehensive Biomedical Research Centre award to Cambridge University Hospitals NHS Foundation Trust in partnership with the University of Cambridge.This is the final version of the article. It first appeared from Wiley via https://doi.org/10.1002/jmri.2518
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