1,320 research outputs found
On certain equations of arbitrary length over torsion-free groups
Let be a non-trivial torsion free group and be an unknown. In this
paper we consider three equations (over ) of arbitrary length and show that
they have a solution (over ) provided two relations among their coefficients
hold. Such equations appear for all lengths greater than or equal to eight and
the results presented in this article can substantially simplify their
solution.Comment: arXiv admin note: substantial text overlap with arXiv:1903.0650
Analysis and Modeling Experiment Performance Parameters of Routing Protocols in MANETs and VANETs
In this paper, a framework for experimental parameters in which Packet
Delivery Ratio (PDR), effect of link duration over End-to-End Delay (E2ED) and
Normalized Routing Overhead (NRO) in terms of control packets is analyzed and
modeled for Mobile Ad-Hoc NETworks (MANETs) and Vehicular Ad-Hoc NETworks
(VANETs) with the assumption that nodes (vehicles) are sparsely moving in two
different road. Moreover, this paper contributes the performance comparison of
one Proactive Routing Protocol; Destination Sequenced Distance vector (DSDV)
and two reactive protocols; DYnamic Source Routing (DSR) and DYnamic MANET
On-Demand (DYMO). A novel contribution of this work is enhancements in default
versions of selected routing protocols. Three performance parameters; PDR, E2ED
and NRO with varying scalabilities are measured to analyze the performance of
selected routing protocols with their original and enhanced versions. From
extensive simulations, it is observed that DSR outperforms among all three
protocols at the cost of delay. NS-2 simulator is used for simulation with
TwoRayGround propagation model to evaluate analytical results
DSDV, DYMO, OLSR: Link Duration and Path Stability
In this paper, we evaluate and compare the impact of link duration and path
stability of routing protocols; Destination Sequence Distance vector (DSDV),
Dynamic MANET On- Demand (DYMO) and Optimized Link State Routing (OLSR) at
different number of connections and node density. In order to improve the
efficiency of selected protocols; we enhance DYMO and OLSR. Simulation and
comparison of both default and enhanced routing protocols is carried out under
the performance parameters; Packet Delivery Ratio (PDR), Average End-to End
Delay (AE2ED) and Normalized Routing Overhead (NRO). From the results, we
observe that DYMO performs better than DSDV, MOD-OLSR and OLSR in terms of PDR,
AE2ED, link duration and path stability at the cost of high value of NRO
Oral health care for patients undergoing therapy for head and neck cancer in KwaZulu-Natal, South Africa - A qualitative study
BACKGROUND: There is limited published evidence in KwaZulu-Natal on access to oral health care for patients undergoing cancer therapy in the head and neck region. OBJECTIVES: This study aimed to assess patients' oral health-related perceptions, practices and needs during cancer therapy. METHODS: This was a descriptive case study. A semi-structured face-to-face interview was conducted with volunteers (n=12) undergoing cancer therapy in head and neck region. Purposive sampling was used to select study participants who were recruited from a public tertiary central referral hospital in KwaZulu-Natal. A semi-structured interview was also conducted with the eThekwini district coordinator for oral health services to gain better insight into oral health service delivery for patients with special needs. RESULTS: The results indicated that oral health care in the sample population was not prioritised. Some of the emergent themes included: participants' knowledge and oral health self-care practices, support for participants to cope with head and neck cancer, barriers in accessing facility-based oral health care (poor access to dental services, failure of the local clinic to provide appropriate care), lack of referral by oncology care practitioners for patients to access dental care, and existing gaps in oral health service delivery The reported non-existence of a specific oral health policy to address cancer and the absence of a risk factor intervention program highlighted some of the shortcomings for quality oral health service delivery in this population group. CONCLUSION: The results indicated that oral health care is important for patients undergoing cancer therapy. There is an urgent need for oral health planning in the province to take into account the specific oral health needs of this vulnerable population
Self-reported oral health status: Perspectives of patients undergoing therapy for cancer of the head and neck region, in the eThekwini District, KZN
There is a dearth of published evidence related to understanding oral health needs for patients undergoing therapy for cancer of the head and neck region in South Africa. This study aimed to assess perceived oral health status of patients undergoing therapy for cancer of the head and neck region, in eTthekwini district, KwaZulu-Natal. This was a cross-sectional case study using quantitative data to determine patients’ perspectives of oral health status and need. The study population comprised 235 voluntary patients (aged between 20-70 years old), undergoing treatment or follow up for cancer therapy of the head and neck region, in a public tertiary referral hospital in the eThekwini district, KwaZulu-Natal. Purposive sampling technique was used for participant selection. The research instrument comprised a combination of two previously validated questionnaires: a core questionnaire (EORTC QLQ-C30, Version 3.0) and the head and neck cancer specific module (EORTC H&N-35). Data was analysed using the statistical package for software sciences (SPSS), version 24. More than half of the study population were male (60%;n= 141). The mean age was 54.38 (SD= 12.30). The results indicate that 14.5% (n=34) were employed, 46.4% (n=109) were unemployed because of cancer and 39.1% (n=92) were unemployed due to other reasons (old age, housewife). Oral cavity cancer was the most common (n=91; 38.7%), followed by laryngeal cancer (n= 53; 22.6%) among all the other head and neck cancers. Males(n=50; 21.3%) were more affected by oral cavity cancer as compared to females (n=41; 17.4%). With reference to treatment, 20.4% (n=48) were on radiotherapy, 28.5% (n=67) were on chemotherapy and 9.8% (n=23) were on CCRT, 17.4% (n=41) had surgery, 8.5% (n=20) were recently diagnosed with cancer of the head and neck and 23.4% (n=55) were on follow up. Oral health-related symptoms were experienced to varying degree by the participants. The majority of participants (n=125; 53.2%) did not report any pain and discomfort. More female participants (n=7; 7.4%) in the age group of 41-60 reported of severedifficulty in swallowing liquids than males of the same age group. Most participants (n=148; 63.0%) had difficulty in swallowing solid foods. Similarly, the majority of participants experienced problems with their teeth (n=162; 69.0%), reported xerostomia (n=159; 67.7%). With reference to trismus, a higher proportion of females (n=27; 28.7%) reported severe trismus compared to male participants (n=33; 23.4%). With reference to increased viscosity of saliva, 34.0% (n=32) of females reported extremely sticky saliva as compared to 29.8% males (n=42)
Effects of Economic and Population Factors on Health Expenditures: Special Case of Pakistan
This paper aims to explore the factors affecting the health care expenditures of Pakistan by employing the Multivariate techniques for the annual data series from 1960 to 2010 .The variables we considered are Gross Domestic Product (GDP) as an economic indicator, Population of age 65 and above (P≥65), Population of age 0 to 14 (P(0-14)), Life expectancy at Birth (LE), Crude Birth rate (CBR) and population growth rate (GR) as population indicator and Total Health Expenditure (THE) as an influencing factor. Multiple regression considering Total Health Expenditure (THE) is applied as dependent on the variables mentioned above. Since Variance Inflation Factor (VIF) for all independent variables are very high, the smallest VIF is around 11 goes up to 65. The results obtained by Principal components reveal the effect of population structure and the age factor effect oppositely on Total Health Expenditures (THE). Factor Analysis suggests that the behavior of Health Expenditures is common with Gross Domestic Product (GDP), population of age 65 and above (P≥65) and life expectancy at Birth (LE) in Pakistan while population of age 0 to 14 (P (0-14)), population growth rate (GR) and Crude Birth rate (CBR) are moving in opposite direction i.e. as GDP, P≥65 and LE of Pakistan increases P (0-14), GR and CBR will decreases
21-Hydroxypregna-1,4-diene-3,20-dione
The title compound, C21H28O3, is a fungal transformed metabolite of decoxycorticosterone acetate, consisting of four fused rings A, B, C and D. Ring A is nearly planar, with a maximum deviation of 0.010 (3) Å from the least-squares plane, while the trans-fused rings B and C adopt chair conformations. The five-membered ring D is in an envelope conformation. The orientation of the side chain is stabilized by an intramolecular O—H⋯O hydrogen bond. In the crystal, adjecent molecules are linked by C—H⋯O hydrogen bonds into extended zigzag chains along the a axis
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Separating snow, clean and debris covered ice in the Upper Indus Basin, Hindukush-Karakoram-Himalayas, using Landsat images between 1998 and 2002
NOTICE: this is the author’s version of a work that was accepted for publication in the Journal of Hydrology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in the Journal of Hydrology
Volume 521, February 2015, Pages 46–64. http://dx.doi.org/10.1016/j.jhydrol.2014.11.048The full text of this version of the article is embargoed for 24 months from the date of publication to meet the publisher's requirementsThe Hindukush Karakoram Himalayan mountains contain some of the largest glaciers of the world, and supply melt water from perennial snow and glaciers to the Upper Indus Basin (UIB) upstream of Tarbela dam, which constitutes greater than 80% of the annual flows, and caters to the needs of millions of people in the Indus Basin. It is therefore important to study the response of perennial snow and glaciers in the UIB under changing climatic conditions, using improved hydrological modeling, glacier mass balance, and observations of glacier responses. However, the available glacier inventories and datasets only provide total perennial-snow and glacier cover areas, despite the fact that snow, clean ice and debris covered ice have different melt rates and densities. This distinction is vital for improved hydrological modeling and mass balance studies. This study, therefore, presents a separated perennial snow and glacier inventory (perennial snow-cover on steep slopes, perennial snow-covered ice, clean and debris covered ice) based on a semi-automated method that combines Landsat images and surface slope information in a supervised maximum likelihood classification to map distinct glacier zones, followed by manual post processing. The accuracy of the presented inventory falls well within the accuracy limits of available snow and glacier inventory products. For the entire UIB, estimates of perennial and/or seasonal snow on steep slopes, snow-covered ice, clean and debris covered ice zones are 7238 ± 724, 5226 ± 522, 4695 ± 469 and 2126 ± 212 km^2 respectively. Thus total snow and glacier cover is 19,285 ± 1928 km^2, out of which 12,075 ± 1207 km^2 is glacier cover (excluding steep slope snow-cover). Equilibrium Line Altitude (ELA) estimates based on the Snow Line Elevation (SLE) in various watersheds range between 4800 and 5500 m, while the Accumulation Area Ratio (AAR) ranges between 7% and 80%. 0 °C isotherms during peak ablation months (July and August) range between ~ 5500 and 6200 m in various watersheds. These outputs can be used as input to hydrological models, to estimate spatially-variable degree day factors for hydrological modeling, to separate glacier and snow-melt contributions in river flows, and to study glacier mass balance, and glacier responses to changing climate
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