5,280 research outputs found

    Downlink Steered Space-Time Spreading Assisted Generalised Multicarrier DS-CDMA Using Sphere-Packing-Aided Multilevel Coding

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    This paper presents a novel generalised Multi-Carrier Direct Sequence Code Division Multiple Access (MC DS-CDMA) system invoking smart antennas for improving the achievable performance in the downlink, as well as employing multi-dimensional Sphere Packing (SP) modulation for increasing the achievable diversity product. In this contribution, the MC DS-CDMA transmitter considered employs multiple Antenna Arrays (AA) and each of the AAs consists of several antenna elements. Furthermore, the proposed system employs both time- and frequency- (TF) domain spreading for extending the achievable capacity, when combined with a novel user-grouping technique for reducing the effects of Multiuser Interference (MUI). Moreover, in order to further enhance the system’s performance, we invoke a MultiLevel Coding (MLC) scheme, whose component codes are determined using the so-called equivalent capacity based constituent-code rate-calculation procedure invoking a 4-dimensional bit-to-SP-symbol mapping scheme. Our results demonstrate an approximately 3.8 dB Eb/N0 gain over an identical throughput scheme dispensing with SP modulation at a BER of 10?5

    Knowledge of HIV/AIDS and attitudes towards people living with HIV among the general staff of a public university in Malaysia

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    Stigma and discrimination towards people living with HIV have been widely documented, and have extended their impact into the workplace. Stigmatising attitudes towards people living with HIV (PLHIV) in the workplace significantly hinder HIV prevention efforts and indirectly affect national development. This cross-sectional study was designed to determine the level of knowledge about HIV and AIDS and assess attitudes towards PLHIV among the general staff of Universiti Putra Malaysia (UPM), as well as to identify factors that are associated with it. Self-administered questionnaires were posted to a total of 344 general staff from six randomly selected faculties, and they were a given a week to return the questionnaires. The response rate was 38%. Data were analysed using Pearson’s correlation, independent t-test and multiple linear  regression. The respondents showed a considerably high level of knowledge about HIV/AIDS (mean knowledge score of 15.57±1.93 out of 18 points) although there were some misconceptions (N=129). Likert scale responses to 20 attitude statements revealed that respondents generally had moderately positive attitudes toward PLHIV (average score of 69.65±10.08 out of 100 points). Attitudes were inconsistent when it involved direct contact and interaction with PLHIV. Factors significantly associated with level of knowledge and attitudes included age, education and income. There was no difference in mean score for knowledge and attitudes by gender. Further efforts are necessary to improve attitudes of the general staff towards PLHIV, particularly in areas of direct contact with PLHIV.Keywords: Knowledge, attitudes, stigma, HIV/AIDS, Malaysia

    An overview of the methane emission from ruminant in Jambi Province, Indonesia.

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    Metan adalah salah satu gas rumah kaca (GRK) utama di samping uap air, karbondioksidJl dan nitrogen oksida. Dibandingkan dengan CO'b metan adalah suatu GRK penting dimana· konsentrasinya di atmosfir lebih dua kIl1i Upat semenjak era pre-industri. Kajian ini memberi gambaran sebuah studi kasus mengenai penilnian emisi gas dan kTedit karbon dJlri ternak ruminansia di Prouinsi Jambi Indonesia. Data merupakan dJlta sekunder meliputi luas daerah, jumlah ternak ruminansia dan kebijakan tentang Tencana ke depan Prouinsi Jambi. Jumlah emisi metan dJlri sapi, kerbau dan kambing adalah 47.83 dan 34,54 ton perhari palla tahun 2002 dan 2006 dJln total emisi C02 dJlri sapi, kerbau dan kambing 131,5 dan 94,96 ton perhari pada tahun 2002 dJln 2006. DiperkiTakan bahwa pQda tahun 2015 PrC1C7insi Jambi dapat menghasilkan dJlri ternak kim-kiTa untuk 69.118 rumah dengan asumsi keperluan listrik 900 watt per-rumah

    Penetration depth study of LaOs4_4Sb12_{12}: Multiband s-wave superconductivity

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    We measured the magnetic penetration depth λ(T)\lambda(T) in single crystals of LaOs4_{4}Sb12_{12} (TcT_c=0.74 K) down to 85 mK using a tunnel diode oscillator technique. The observed low-temperature exponential dependence indicates a s-wave gap. Fitting the low temperature data to BCS s-wave expression gives the zero temperature gap value Δ(0)=(1.34±0.07)kBTc\Delta (0)= (1.34 \pm 0.07) k_B T_c which is significantly smaller than the BCS value of 1.76kBTck_B T_c. In addition, the normalized superfluid density ρ(T)\rho(T) shows an unusually long suppression near TcT_c, and are best fit by a two-band s-wave model.Comment: 5 pages, 2 figure

    Anisotropic Universe in f(Q,T)f(Q,T) gravity, a novel study

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    f(Q,T)f(Q,T) theory of gravity is very recently proposed to incorporate within the action Lagrangian, the trace TT of the energy-momentum tensor along with the non-metricity scalar QQ. The cosmological application of this theory in a spatially flat isotropic and homogeneous Universe is well-studied. However, our Universe is not isotropic since the Planck era and therefore to study a complete evolution of the Universe we must investigate the f(Q,T)f(Q,T) theory in a model with a small anisotropy. This motivated us to presume a locally rotationally symmetric (LRS) Bianchi-I spacetime and derive the motion equations. We analyse the model candidate f(Q,T)=αQn+1+βTf(Q,T)=\alpha Q^{n+1}+\beta T, and to constrain the parameter nn, we employ the statistical Markov chain Monte Carlo (MCMC) method with the Bayesian approach using two independent observational datasets, namely, the Hubble datasets, and Type Ia supernovae (SNe Ia) datasets.Comment: AOP accepted versio

    Dietary dairy product intake and incident type 2 diabetes: a prospective study using dietary data from a 7-day food diary

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    The consumption of specific dairy types may be beneficial for the prevention of diabetes. Abstract: The aim of this study was to investigate the association between total and types of dairy product intake and risk of developing incident type 2 diabetes, using a food diary. Methods: A nested case-cohort within the EPIC-Norfolk Study was examined, including a random subcohort (n=4,000) and cases of incident diabetes (n=892, including 143 cases in the subcohort) followed-up for 11 years. Diet was assessed using a prospective 7-day food diary. Total dairy intake (g/day) was estimated and categorised into high-fat (≥3.9%) and low-fat (<3.9% fat) dairy, and by subtype into yoghurt, cheese and milk. Combined fermented dairy product intake (yoghurt, cheese, sour cream) was estimated and categorised into high- and low-fat. Prentice-weighted Cox regression HRs were calculated. Results: Total dairy, high-fat dairy, milk, cheese and high-fat fermented dairy product intakes were not associated with the development of incident diabetes. Low-fat dairy intake was inversely associated with diabetes in age- and sex-adjusted analyses (tertile [T] 3 vs T1, HR 0.81 [95% CI 0.66, 0.98]), but further adjustment for anthropometric, dietary and diabetes risk factors attenuated this association. In addition, an inverse association was found between diabetes and low-fat fermented dairy product intake (T3 vs T1, HR 0.76 [95% CI 0.60, 0.99]; ptrend=0.049) and specifically with yoghurt intake (HR 0.72 [95% CI 0.55, 0.95]; ptrend=0.017) in multivariable adjusted analyses. Conclusions/interpretation: Greater low-fat fermented dairy product intake, largely driven by yoghurt intake, was associated with a decreased risk of type 2 diabetes development in prospective analyses. These findings suggest that the consumption of specific dairy types may be beneficial for the prevention of diabetes, highlighting the importance of food group subtypes for public health messages

    RPGR-associated retinopathy: clinical features, molecular genetics, animal models and therapeutic options

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    Retinitis pigmentosa GTPase regulator (RPGR) gene sequence variants account for the vast majority of X linked retinitis pigmentosa (RP), which is one of the most severe forms of RP. Symptoms of nyctalopia typically begin in childhood, with increasing loss of peripheral visual field during teenage years, and progressive central visual loss during the second to fourth decade of life. There is however marked intrafamilial and interfamilial phenotypic heterogeneity in affected males and carrier females. There is now a far greater understanding of the range of phenotypes associated with variants in this gene; including rod-cone dystrophy, cone-rod dystrophy, cone dystrophy, macular dystrophy and non-ocular phenotypes. There are also increasingly established genotype-phenotype associations and structure-function correlations. RPGR is involved in ciliary function, with ciliary dysfunction now recognised as the mechanism underlying a large proportion of inherited retinal disease. There has been significant progress in identifying naturally occurring animal models and developing novel models to define the underlying disease mechanisms and to test gene replacement therapy, in addition to advances in human retinal imaging, culminating in completed and planned clinical trials. These significant developments will be discussed

    Quantitative Analysis of Retinal Structure Using Spectral-Domain Optical Coherence Tomography in RPGR-Associated Retinopathy

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    PURPOSE: To quantify retinal structure and progression using spectral-domain optical coherence tomography (SDOCT) in patients with retinitis pigmentosa (RP) associated with retinitis pigmentosa GTPase regulator gene (RPGR) mutations. DESIGN: Retrospective observational case series. METHODS: Setting: Moorfields Eye Hospital, London, United Kingdom. Subjects: Both eyes of 32 patients. SDOCT follow-up period of >1 year (3.1 ± 1.4 years). Main Outcome Measures: Ellipsoid zone (EZ) width (EZW) and outer nuclear layer (ONL) and inner retinal layer (IRL) thickness measurements. Progression rates, interocular symmetry, and association with age and genotype were investigated. RESULTS: Significant differences were observed between baseline and final measurements of EZW and ONL thickness, but not for IRL thickness. Baseline and final EZWs were 2438 ± 1646 μm and 1901 ± 1423 μm for right eyes (P < .0001); 2420 ± 1758 μm and 1922 ± 1482 μm for left eyes (P < .0001). EZW constriction rates were 176.6 ± 130.1 μm/year and 173.1 ± 146.8 μm/year for right and left eyes. ONL thinning rates were 2.58 ± 2.85 μm/year and 2.52 ± 3.54 μm/year for right and left eyes. Interocular differences in EZW and ONL progression were not significant (P = .8609 and P = .6735, respectively). Strong correlations were found between EZW constriction rates of right and left eyes (rs = 0.627, P = .0002) and between EZW constriction and baseline EZW (rs = 0.714, P < .0001). There was moderate negative correlation between EZW constriction and age (rs = −0.532, P < .0001). Correlation between ONL thinning and age was not significant, as were differences between EZW and ONL progression rates with respect to genotype. CONCLUSIONS: This study provides SDOCT progression rates for RPGR-associated RP. There is overall interocular symmetry with implications for future treatment trials where 1 eye could serve as a control

    Managing the mutations: Academic misconduct Australia, New Zealand and the UK

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    Academic misconduct is a problem of growing concern across the tertiary education sector. While plagiarism has been the most common form of academic misconduct, the advent of software programs to detect plagiarism has seen the problem of misconduct simply mutate. As universities attempt to function in an increasingly complex environment, the factors that contribute to academic misconduct are unlikely to be easily mitigated. A multiple case study approach examined how academic misconduct is perceived in universities in in Australia, New Zealand and the United Kingdom via interviews with academics and administrators. The findings show that academic misconduct is a systemic problem that manifests in various ways and requires similarly diverse approaches to management. Greater consistency in policies and procedures, including a focus on preventative education for both staff and students, is key, to managing the mutations of academic misconduct that continue to plague the higher education sector globally

    Emerging treatment options for short bowel syndrome: potential role of teduglutide

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    INTRODUCTION: Current medical management of short bowel syndrome (SBS) involves the use of lifelong parenteral nutrition (PN). Glucagon-like peptide-2 (GLP-2), an important intestinotrophic growth factor has been shown to increase intestinal absorption in SBS through augmentation of post-resection intestinal adaptation. This may lead to the reduction of PN dependence in patients with SBS. AREAS COVERED IN REVIEW: Advancing research of GLP-2 physiology has spurred the growing understanding of the diverse effects of GLP-2. The development of the degradation resistant GLP-2 analog, teduglutide (Gattex(TM), NPS Pharmaceuticals, Bedminster, NJ), has allowed its exploration as a therapeutic agent in a variety of clinical settings. Recent multicenter, placebo-controlled studies of GLP-2 in SBS patients demonstrate meaningful reductions in PN requirements with good safety profiles. The reparative and immunomodulatory effects of teduglutide may also be beneficial in patients with inflammatory bowel disease (IBD). Safety concerns about possible carcinogenic properties during long-term use require ongoing evaluation. SUMMARY: GLP-2 appears to offer a novel adjuvant treatment modality for SBS. Promise for its use in other clinical settings like IBD has been shown in small pilot studies
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