146 research outputs found
Investigation of the role of chemical composition on the weathering and emulsification behaviour of North Sea crude oil
The exploration, production, transportation and refining of petroleum often pose
great technical and environmental challenges to the oil and gas industry. It is
therefore extremely important to reliably predict and control fluid behaviour, in
order to optimize production cost and for purposes of potential environmental
pollution in the oil and gas operational activities. The investigations in this work
focuses upon North Sea crude oils. In view of the fact that the North Sea crude oils
are derived from the same source rock (Kimmeridge), they would be expected to
have the same chemistry, but however, they tend to behave differently. The
objectives of the research were to develop a better understanding of the effect of
temperature and time on evaporation rate and its role in modifying the rate of
weathering of North Sea crude oils on seawater. In this research, the chemistry of
the oils was investigated to see the relationship to their emulsification behaviour. In
the first part of this thesis, the weathering behaviour of four North Sea crude oils
were investigated, in particular the evaporation, using a novel evaporation method.
It was observed that the rate of evaporation varied between the North Sea oils.
Evaporation of emulsified oil differed to unemulsified oil. North Sea crude oils of
different states of weathering were emulsified and their viscosities and water
contents measured. The four oils produced emulsion types of different viscosities
and states of stability. The effects of degree of weathering of oils on emulsion states
were assessed. The chemistry of the four North Sea crudes was investigated using a
range of analytical techniques. The oils were fractionated by SARA analysis to
produce saturates, aliphatic, resins and asphaltene fractions, prior to chemical
analyses, using a range of analytical techniques (The crude oils were fractionated
and the fractions analyzed for their chemical compositions). The compositions of
the four crude oils differed to one another. From these analyses, a number of
parameters were selected to characterize the oils. These were polarity, aromaticity
and alkyl side chain. These data were used in a modeling study. The asphaltenes
from the North Sea crudes investigated were substituted into both synthetic and
model oils to study the effect on emulsification. It was observed that the asphaltenes
had an effect on the emulsification behaviour. The behavior of modeled asphaltene
structures based on the chemical characterization data was found to correlate with
the emulsification behavior of the North Sea crudes investigatedAkwa Ibom State University of Technology (AKUTECH
Evidence of Rift Valley Fever Virus circulation in livestock and herders in southern Ghana
DATA AVAILABILITY:The data presented in this study are available on request from the
corresponding authors. The data are not publicly available due to ethical reasons.Rift Valley fever (RVF) is a re-emerging zoonotic disease of domestic ruminants and humans.
While neighbouring countries have reported outbreaks of RVF, Ghana has not yet identified any cases.
The aim of this study was to determine whether RVF virus (RVFV) was circulating in livestock and
herders in the southern part of Ghana, to estimate its seroprevalence, and to identify associated risk
factors. The study surveyed 165 livestock farms randomly selected from two districts in southern
Ghana. Serum samples of 253 goats, 246 sheep, 220 cattle, and 157 herdsmen were tested to detect
IgG and IgM antibodies against RVFV. The overall seroprevalence of anti-RVF antibodies in livestock
was 13.1% and 30.9% of farms had RVFV seropositive animals. The species-specific prevalence was
24.1% in cattle, 8.5% in sheep, and 7.9% in goats. A RVFV IgG seroprevalence of 17.8% was found
among the ruminant herders, with 8.3% of all herders being IgM positive. RVFV was shown, for
the first time, to have been circulating in southern Ghana, with evidence of a recent outbreak in
Kwahu East; however, it was clinically undetected despite significant recent human exposure. A
One Health approach is recommended to better understand RVF epidemiology and socio-economic
impact in Ghana.Future Africa Institute, University of Pretoria with funding
from Carnegie Corporation of New York and BANGA Africa Project of University of Ghana. The
APC was funded by Future Africa, University of Pretoria.https://www.mdpi.com/journal/virusesMedical VirologyProduction Animal Studie
RIG-I, MDA5 and TLR3 Synergistically Play an Important Role in Restriction of Dengue Virus Infection
Dengue virus (DV) infection is one of the most common mosquito-borne viral diseases in the world. The innate immune system is important for the early detection of virus and for mounting a cascade of defense measures which include the production of type 1 interferon (IFN). Hence, a thorough understanding of the innate immune response during DV infection would be essential for our understanding of the DV pathogenesis. A recent application of the microarray to dengue virus type 1 (DV1) infected lung carcinoma cells revealed the increased expression of both extracellular and cytoplasmic pattern recognition receptors; retinoic acid inducible gene-I (RIG-I), melanoma differentiation associated gene-5 (MDA-5) and Toll-like receptor-3 (TLR3). These intracellular RNA sensors were previously reported to sense DV infection in different cells. In this study, we show that they are collectively involved in initiating an effective IFN production against DV. Cells silenced for these genes were highly susceptible to DV infection. RIG-I and MDA5 knockdown HUH-7 cells and TLR3 knockout macrophages were highly susceptible to DV infection. When cells were silenced for only RIG-I and MDA5 (but not TLR3), substantial production of IFN-β was observed upon virus infection and vice versa. High susceptibility to virus infection led to ER-stress induced apoptosis in HUH-7 cells. Collectively, our studies demonstrate that the intracellular RNA virus sensors (RIG-I, MDA5 and TLR3) are activated upon DV infection and are essential for host defense against the virus
Kinematic analysis of the daily activity of drinking from a glass in a population with cervical spinal cord injury
Background
Three-dimensional kinematic analysis equipment is a valuable instrument for studying the execution of movement during functional activities of the upper limbs. The aim of this study was to analyze the kinematic differences in the execution of a daily activity such as drinking from a glass between two groups of patients with tetraplegia and a control group.
Methods
A total of 24 people were separated into three groups for analysis: 8 subjects with metameric level C6 tetraplegia, 8 subjects with metameric level C7 tetraplegia and 8 control subjects (CG). A set of active markers that emit infrared light were positioned on the upper limb. Two scanning units were used to record the sessions. The activity of drinking from a glass was broken down into a series of clearly identifiable phases to facilitate analysis. Movement times, velocities, and the joint angles of the shoulder, elbow and wrist in the three spatial planes were the variables analyzed.
Results
The most relevant differences between the three groups were in the wrist. Wrist palmar flexion during the back transport phase was greater in the patients with C6 and C7 tetraplegia than in the CG, whereas the highest wrist dorsal flexion values were in forward transport in the subjects with C6 or C7 tetraplegia, who required complete activation of the tenodesis effect to complete grasping.
Conclusions
A detailed description was made of the three-dimensional kinematic analysis of the task of drinking from a glass in healthy subjects and in two groups of patients with tetraplegia. This was a useful application of kinematic analysis of upper limb movement in a clinical setting. Better knowledge of the execution of this movement in each of these groups allows therapeutic recommendations to be specifically adapted to the functional deficit present. This information can be useful in designing wearable robots to compensate the performance of AVD, such as drinking, in people with cervical SCI
The effectiveness and cost-effectiveness of strength and balance Exergames to reduce falls risk for people aged 55 years and older in UK assisted living facilities: A multi-centre, cluster randomised controlled trial
Background:
Falls are the leading cause of fatal and non-fatal unintentional injuries in older people. The use of Exergames (active, gamified video-based exercises) is a possible innovative, community-based approach. This study aimed to determine the effectiveness of a tailored OTAGO/FaME based strength and balance Exergame programme for improving balance, maintaining function and reducing falls risk in older people.
Methods:
A two-arm cluster randomised controlled trial recruiting adults aged 55 years and older living in 18 assisted-living (sheltered housing) facilities (clusters) in the UK. Standard care (physiotherapy advice and leaflet) was compared to a tailored 12-week strength and balance Exergame programme, supported by physiotherapists or trained assistants. Complete-case analysis (intention to treat) was used to compare Berg Balance Scale (BBS) at baseline and at 12 weeks. Secondary outcomes included: fear of falling, mobility, falls risk, pain, mood, fatigue, cognition, healthcare utilisation and health-related quality of life; self-reported physical activity and falls.
Results:
Eighteen clusters were randomised (9 to each arm) with 56 participants allocated to the intervention and 50 to the control (78% female, mean age 78 years). Fourteen participants withdrew over the 12 weeks (both arms), mainly for ill health. There was an adjusted mean improvement in balance (BBS) of 6.2 (95% CI 2.4 to 10.0), reduced fear of falling (p=0.007) and pain (p=0.02) in Exergame group. Mean attendance at sessions was 69% (mean exercising time of 33 minutes/week). 24% of control group and 20% of Exergame group fell over trial period. The change in falls rates significantly favoured the intervention (incident rate ratio 0.31 (95% CI 0.16 to 0.62, p=0.001)). The point estimate of the incremental cost effectiveness ratio (ICER) was £15,209.80 per QALY. Using 10,000 bootstrap replications, at the lower bound of the NICE threshold of £20,000 per QALY, there was a 61% probability of Exergames being cost-effective, rising to 73% at the upper bound of £30,000 per QALY.
Conclusions:
Exergames, as delivered in this trial, improve balance, pain and fear of falling and are a cost-effective fall prevention strategy in assisted living facilities for people aged 55 years or older
Identification of women at risk for developing postmenopausal osteoporosis with vertebral fractures: role of history and single photon absorptiometry
Putative risk factors for the development of postmenopausal osteoporosis (PMO) with vertebral fractures were examined in a retrospective study of 663 postmenopausal white females aged 45-75 years (266 women with non-traumatic vertebral compression fractures (VF+), 134 non-fractured women from a general medicine clinic (controls) and 263 non-fractured women who were evaluated when they presented specifically for osteoporosis screening (VF-)). The VF+ women differed from control women in several respects. The VF+ group reported a higher prevalence of a positive family history of osteoporosis, and a higher prevalence of a history of medical or surgical conditions known to be independently associated with metabolic bone disease, had fewer children, were smaller (weight, height) and were slightly older. The two groups, VF+ and controls, did not differ with respect to cigarette smoking, alcohol consumption, exercise habits, menstrual or menopausal history, dietary intake of milk and cheese or in amount taking calcium supplements during pregnancy.The VF+ group also differed in certain respects from the VF- group. The VF+ group were smaller (weight, height) and were older. The VF+ group had lower cortical bone mass (measured by single photon absorptiometry of the non-dominant forearm) than either the control or VF- groups. The latter two groups did not differ from each other with respect to this measurement.These markers demonstrated limited sensitivity and specificity as estimated from a confirmatory data set, particularly for the historical and anthropometric variables. We conclude that an assessment of the risk of developing PMO with vertebral fractures cannot be based on the putative risk factors as measured in our study, but must be based on measurement of bone mass.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27770/1/0000164.pd
Ground seed density patterns under conditions of strongly overlapping seed shadows in Abies alba Mill. stands
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Global burden of peripheral artery disease and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
Background
Peripheral artery disease is a growing public health problem. We aimed to estimate the global disease burden of peripheral artery disease, its risk factors, and temporospatial trends to inform policy and public measures.
Methods
Data on peripheral artery disease were modelled using the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2019 database. Prevalence, disability-adjusted life years (DALYs), and mortality estimates of peripheral artery disease were extracted from GBD 2019. Total DALYs and age-standardised DALY rate of peripheral artery disease attributed to modifiable risk factors were also assessed.
Findings
In 2019, the number of people aged 40 years and older with peripheral artery disease was 113 million (95% uncertainty interval [UI] 99·2–128·4), with a global prevalence of 1·52% (95% UI 1·33–1·72), of which 42·6% was in countries with low to middle Socio-demographic Index (SDI). The global prevalence of peripheral artery disease was higher in older people, (14·91% [12·41–17·87] in those aged 80–84 years), and was generally higher in females than in males. Globally, the total number of DALYs attributable to modifiable risk factors in 2019 accounted for 69·4% (64·2–74·3) of total peripheral artery disease DALYs. The prevalence of peripheral artery disease was highest in countries with high SDI and lowest in countries with low SDI, whereas DALY and mortality rates showed U-shaped curves, with the highest burden in the high and low SDI quintiles.
Interpretation
The total number of people with peripheral artery disease has increased globally from 1990 to 2019. Despite the lower prevalence of peripheral artery disease in males and low-income countries, these groups showed similar DALY rates to females and higher-income countries, highlighting disproportionate burden in these groups. Modifiable risk factors were responsible for around 70% of the global peripheral artery disease burden. Public measures could mitigate the burden of peripheral artery disease by modifying risk factors.
Funding
Bill & Melinda Gates Foundation
Comprehensive molecular characterization of the hippo signaling pathway in cancer
Hippo signaling has been recognized as a key tumor suppressor pathway. Here, we perform a comprehensive molecular characterization of 19 Hippo core genes in 9,125 tumor samples across 33 cancer types using multidimensional “omic” data from The Cancer Genome Atlas. We identify somatic drivers among Hippo genes and the related microRNA (miRNA) regulators, and using functional genomic approaches, we experimentally characterize YAP and TAZ mutation effects and miR-590 and miR-200a regulation for TAZ. Hippo pathway activity is best characterized by a YAP/TAZ transcriptional target signature of 22 genes, which shows robust prognostic power across cancer types. Our elastic-net integrated modeling further reveals cancer-type-specific pathway regulators and associated cancer drivers. Our results highlight the importance of Hippo signaling in squamous cell cancers, characterized by frequent amplification of YAP/TAZ, high expression heterogeneity, and significant prognostic patterns. This study represents a systems-biology approach to characterizing key cancer signaling pathways in the post-genomic era
The quality factor in consumers’ preference of textile fabrics: a comparative evaluation of consumer preference for domestic and imported textile fabrics (wrappers) in Abakaliki, Ebonyi state, Nigeria
The objective of the study was to determine if there is any significant difference between domestic and imported textile fabrics (wrappers) with respect to design, colourfastness and durability attributes and in terms of overall quality. Exploratory and descriptive research designs were adopted in the study. Primary data were collected from 312 female respondents in nine zones within Abakaliki Urban, with the use of questionnaire. Data collected were analyzed using frequencies, percentages and means, while Kruskal-Wallis rank test and Z-test were used to test the hypotheses. From data analysis, these findings became evident: Imported wrappers possess higher quality than domestic wrappers; domestic wrappers have attribute weakness in durability, colourfastness, texture, fabric strength and weight. There were brands of domestic wrappers (Nichem Wax and Nigerian Wax) identified as possessing high quality, while other brands (Super Print, Top Wax, Ankara, Veritable Real Wax) were indicated as washing off colour. The implication of the findings is that domestic textile firms must re-engineer their marketing strategies and programmes. Based on the findings the researchers recommended that domestic textile firms should embark on product modification; entrench product innovation in their strategic plans; collect vital customer information through monitoring research and be abreast with current developments in the textile market and industry under study.Keywords: Quality, Preference, Textile fabrics, Textile fabric attributes
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