5,662 research outputs found
Developing sexual competence? Exploring strategies for the provision of effective sexualities and relationships education
School-based sexualities and relationships education (SRE) offers one of the most promising means of improving young people's sexual health through developing 'sexual competence'. In the absence of evidence on whether the term holds the same meanings for young people and adults (e.g. teachers, researchers, policy-makers), the paper explores 'adult' notions of sexual competence as construed in research data and alluded to in UK Government guidance on SRE, then draws on empirical research with young people on factors that affect the contexts, motivations and outcomes of sexual encounters, and therefore have implications for sexual competence. These data from young people also challenge more traditional approaches to sexualities education in highlighting disjunctions between the content of school-based input and their reported sexual experience. The paper concludes by considering the implications of these insights for developing a shared notion of what SRE is trying to achieve and suggestions for recognition in the content and approaches to SRE.</p
Exchange Narrowing Effects in the EPR Linewidth of Gd Diluted in Ce Compounds
Anomalous thermal behavior on the EPR linewidths of Gd impurities diluted in
Ce compounds has been observed. In metals, the local magnetic moment EPR
linewidth, \Delta H, is expected to increase linearly with the temperature. In
contrast, in Ce_{x}La_{1-x}Os_{2} the Gd EPR spectra show a nonlinear increase.
In this work, the mechanisms that are responsible for the thermal behavior of
the EPR lines in Ce_{x}La_{1-x}Os_{2} are examined. We show that the exchange
interaction between the local magnetic moments and the conduction electrons are
responsible for the narrowing of the spectra at low temperatures. At high
temperatures, the contribution to the linewidth of the exchange interaction
between the local magnetic moments and the ions has an exponential
dependence on the excitation energy of the intermediate valent ions. A complete
fitting of the EPR spectra for powdered samples is obtained.Comment: 11 pages, 1 figur
Influence of Rice Husk Ash Density on the Workability and Strength of Structural Concrete
Supplementary cementitious materials (SCMs) have been known to improve the properties of fresh and hardened concrete, and at the same time enhance the sustainability of concrete. Rice husk Ash (RHA), is one such material, but has neither been widely studied nor applied in practice. This work investigated the effect of the density of RHA on the workability and compressive strength of fresh and hardened RHA-replaced concrete respectively. Cement was replaced with RHA in concrete by weight (RHA-W) and by volume (RHA-V) at steps of 0%, 5%, 7.5%, 10%, 15%, 20%, 25% and 30%. The 0% replacement was used as the reference point from which performances were measured. Results showed that unlike the characteristic of other established pozzolans, RHA significantly reduced the workability of wet concrete and the rate of compressive strength gain over curing time due to a high water demand that is caused by the increased volume of replaced concrete, which results from its low density. Workability reduced with increased replacement for both RHA-W and RHA-V. Replacements of above 15% were not possible for the RHA-W due to the high water demand. However, replacements of up to 30% were achieved for the RHA-V. RHA-W specimens achieved lower compressive strengths and were observed to gain strength at a lower rate over the 28 to 91-days period of curing compared to RHA-V specimens. This behavior was attributed to the shortage of water that is necessary for the hydration of cement and subsequent pozzolanic reaction, which is the basis of the contribution that is made to the strength and performance of concrete by SCMs. However, the compressive strengths achieved were above the study’s target concrete strength of class C32/40 at 91 days, which is among those classes that are listed as being durable and suitable for structural applications. A conclusion that RHA should supplement cements by volumetric replacement rather than simple substitution by weight was drawn
Digital Asset Marketing: Traceability as a competitive advantage in a low carbon economy
The digital world and big data technologies have seen exponential growth in recent years (Ashwin Kumar, 2017). According to International Data Corporation (IDC) corporate spending on Blockchain solutions expected to reach $19 Billion in 2024. Blockchain eliminates the need for a trusted third party where suppliers could transact and trade directly with customers, ensure the data integrity and trace and track assets efficiently (Lacity 2018). Iansiti and Lakhani (2017) demonstrate other characteristics of block chain technology that could stimulate new business models or opportunities. Maroun and Daniel (2019) and Daniel (2021) confirm that there are significant opportunities to adopt blockchain technology in the supply chain. Nascent marketing research, such as Dwivedi et al (2021), suggest a plethora of opportunities for marketing researchers to explore. This research however focuses on the potential of blockchain tokens to trace products through the supply chain and deliver a competitive advantage to companies that seek to promote their carbon and environmental credentials
'Selling it as a holistic health provision and not just about condoms ?' Sexual health services in school settings: current models and their relationship with sex and relationships education policy and provision
In this article we discuss the findings from a recent study of UK policy and practice in relation to sexual health services for young people, based in - or closely linked with - schools. This study formed part of a larger project, completed in 2009, which also included a systematic review of international research. The findings discussed in this paper are based on analyses of interviews with 51 service managers and questionnaire returns from 205 school nurses. Four themes are discussed. First, we found three main service permutations, in a context of very diverse and uneven implementation. Second, we identified factors within the school context that shaped and often constrained service provision; some of these also have implications for sex and relationships education (SRE). Third, we found contrasting approaches to the relationship between SRE input and sexual health provision. Fourth, we identified some specific barriers that need to be addressed in order to develop 'young people friendly' services in the school context. The relative autonomy available to school head teachers and governors can represent an obstacle to service provision - and inter-professional collaboration - in a climate where, in many schools, there is still considerable ambivalence about discussing 'sex' openly. In conclusion, we identify areas worthy of further research and development, in order to address some obstacles to sexual health service and SRE provision in schools
Crystal Distortion and the Two-Channel Kondo Effect
We study a simple model of the two-channel Kondo effect in a distorted
crystal. This model is then used to investigate the interplay of the Kondo and
Jahn-Teller effects, and also the Kondo effect in an impure crystal. We find
that the Jahn-Teller interaction modifies the characteristic energy scale of
the system below which non-Fermi-liquid properties of the model become
apparent. The modified energy scale tends to zero as the limit of a purely
static Jahn-Teller effect is approached. We find also that the non-Fermi-liquid
properties of the quadrupolar Kondo effect are not stable against crystal
distortion caused by impurities.Comment: 11 page
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The majority of re-activatable latent HIV proviruses are genetically distinct with no evidence of ongoing evolution
Background
Two mechanisms have been proposed to contribute in to the maintenance of the HIV latent reservoir: homeostatic proliferation of latently infected cells and low level viral replication in the lymphoid tissue. Here we studied the sequences of reactivatable latent viruses obtained from a stably treated patient to assess the importance of these mechanisms.
Methods
Resting CD4+ T cells were isolated at regular intervals from the patient, underwent limiting dilution, were activated and then co-cultured with SupT1-CCR5 cells for 21 days. The supernatant was harvested for viral RNA. Regions in gag and env were analysed by Sanger sequencing. To control for artefacts from culture and sequencing, SupT1-CCR5 cells were infected with NL4-3 and underwent the same limiting dilution, culture, and sequencing processes. Pairwise comparisons were performed to obtain p-distances. Each pair of patient derived viral sequences was considered distinct if the p-distance was higher than that of the corresponding region of the sequences from NL4-3 infected SupT1-CCR5 cells. To seek evidence of viral evolution, a consensus was created from the viral sequences obtained from the first sample and sequences from samples obtained subsequently were compared against this baseline consensus.
Results
We obtained 32 sequences of reactivated latent viruses from a single patient. 18 distinct sequences could be distinguished from the gag region. The remaining 14 sequences segregated into five groups. However, when the env regions of these 14 sequences were analysed, only one ‘clonal’ group of two sequences remained. 30/32 reactivated latent viruses were distinct. If the threshold p-distance for two sequences to be considered distinct was set at the maximal (rather than average) p-distance observed in the reference set, 26/32 of reactivated latent viruses would still be considered distinct. We have not observed any increase in p-distances over 28 weeks of sampling compared to the baseline samples to suggest of accumulation of mutations.
Conclusion
Our results show that the majority of reactivatable latent viruses are genetically distinct. Persistent viral evolution was not observed in the latent reservoir harboured in peripheral blood resting CD4+ T cells in this stably treated patient
Performance of Anthill Soil Replaced Concrete in Sulfate Solutions
Durability of concrete is defined as its ability to resist any form of deterioration, allowing it to retain its original form and quality after it has been exposed to the environment of its intended use. Sulfate attack causes concrete to lose its compressive strength through the decomposition of the products of hydration of cement. Pozzolanic reactions from Supplementary Cementitious Materials (SCMs) help in resisting the sodium sulfate (Na2SO4) attack. This work investigated the potential use of Anthill Soil (AHS) to improve the performance of concrete in sulfate aggressive environments. An AHS replacement of 30% (per cent) by the weight of cement was used to make concrete test bars and cubes. The 0% replacement also referred to as the control was used as the point of reference from which all performances were measured. The specimens were immersed in 5% Na2SO4, 5% magnesium sulfate (MgSO4), and 5% mixed solution of Na2SO4 and MgSO4. Elongation measurements were taken over a period of 9 months, whereas compressive strength tests, which were used to work out the Strength Deterioration Factors (SDFs) and visual observations for surface deterioration were carried out at 9 months. From the results, AHS specimens that were immersed in the Na2SO4, MgSO4 and mixed Na2SO4 and MgSO4 solutions performed poorly in elongation compared with the control specimens, but had lower SDFs in the Na2SO4 and mixed solutions of Na2SO4 and MgSO4. The surface deterioration of AHS specimens in the MgSO4 solution was worse than that of the control specimens but was similar to that of the control in the mixed sulfate solution of Na2SO4 and MgSO4. The SDF results highlight the potential of using AHS with an advantage in Na2SO4 and mixed Na2SO4 and MgSO4 environments
Number counts and clustering properties of bright Distant Red Galaxies in the UKIDSS Ultra Deep Survey Early Data Release
We describe the number counts and spatial distribution of 239 Distant Red
Galaxies (DRGs), selected from the Early Data Release of the UKIDSS Ultra Deep
Survey. The DRGs are identified by their very red infrared colours with
(J-K)AB>1.3, selected over 0.62 sq degree to a 90% completeness limit of
KAB~20.7. This is the first time a large sample of bright DRGs has been studied
within a contiguous area, and we provide the first measurements of their number
counts and clustering. The population shows strong angular clustering,
intermediate between those of K-selected field galaxies and
optical/infrared-selected Extremely Red Galaxies. Adopting the redshift
distributions determined from other recent studies, we infer a high correlation
length of r0~11 h-1 Mpc. Such strong clustering could imply that our galaxies
are hosted by very massive dark matter halos, consistent with the progenitors
of present-day L>L* elliptical galaxies.Comment: 5 pages, 4 figures, revised version accepted to MNRAS.
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