Finite driving rate and anisotropy effects in landslide modeling

In order to characterize landslide frequency-size distributions and individuate hazard scenarios and their possible precursors, we investigate a cellular automaton where the effects of a finite driving rate and the anisotropy are taken into account. The model is able to reproduce observed features of landslide events, such as power-law distributions, as experimentally reported. We analyze the key role of the driving rate and show that, as it is increased, a crossover from power-law to non power-law behaviors occurs. Finally, a systematic investigation of the model on varying its anisotropy factors is performed and the full diagram of its dynamical behaviors is presented.Comment: 8 pages, 9 figure

A new test procedure to measure the soil-water characteristic curves using a small-scale centrifuge

ABSTRACT: The soil-water characteristic curve is conventionally measured using a pressure plate apparatus or a Tempe cell. Considerably long periods of time are required to measure the soil-water characteristic curves using the conventional equipment. A new test procedure is proposed, using a small-scale medical centrifuge to measure the soil-water characteristic curves for compacted, fine-grained soil specimens. Soil specimen holders were designed for the small-scale centrifuge. The soil-water characteristic curves of statically compacted specimens for three different fine-grained soils with varying percentages of clay were measured using the centrifuge for a suction range between 0 to 500 kPa. There is good comparison between the soil-water characteristic curves measured using the small-scale centrifuge and the conventional laboratory equipment. The results of this study are encouraging as soil-water characteristic curves can be measured in a shorter period of time, resulting in considerable savings

Evaluating the Ability of Swell Prediction Models to Predict the Swell Behavior of Excessively High Plastic Soils

Lightly loaded structures underneath expansive soils encounter severe damage due to the swell/shrink nature of expansive soils resulting from moisture variations. Billions of dollars are spent every year to repair the damages caused by these soils in the U.S. and worldwide. Designing structures to accommodate the swelling strains is a major challenge as predicting the swelling potential of these soils accurately is not easy. A wide variety of swell prediction models have been introduced by various researchers to predict the behavior of these often-problematic expansive soils. These models include various properties of soils such as, plasticity characteristics, compaction conditions, consolidation characteristics, moisture content variations, matric suction, and clay mineralogical characteristics. However, these models are generally developed with typical moderate to high plastic soils in mind whose plasticity indices range from 25 to 45. Their applicability to soils that have liquid limits in the order of 200% is not well understood. In this paper, the ability of these models to predict the behavior of excessively high plastic soils with plasticity indices ranging from 45 to 85 were evaluated. For this purpose, four existing analytical prediction models that use combinations of above-mentioned properties were selected and used to predict the one-dimensional and three-dimensional swelling strains on three high swelling soils. These predictions were verified by conducting one-dimensional and three-dimensional swell tests on the three soil types. The swell tests were conducted at three different initial moisture contents to observe how well the models could predict different levels of moisture absorption. The ability of each of the four selected methods in predicting both 1D and 3D swell strains was discussed and their relative merits and demerits are highlighted. In addition, finite element modeling was performed to simulate one-dimensional and three-dimensional swell tests by using material models that use volumetric and suction changes with moisture contents to simulate expansive soil behavior within the finite element model. The results indicated that while the analytical prediction models gave reasonable results the finite element analysis predicted results were closest to the laboratory measure soils in case both 1D and 3D analyses. Among other analytical models the ones that incorporated mineralogical and suction data exhibited better results

Task shifting and integration of HIV care into primary care in South Africa: The development and content of the streamlining tasks and roles to expand treatment and care for HIV (STRETCH) intervention

Background: Task shifting and the integration of human immunodeficiency virus (HIV) care into primary care services have been identified as possible strategies for improving access to antiretroviral treatment (ART). This paper describes the development and content of an intervention involving these two strategies, as part of the Streamlining Tasks and Roles to Expand Treatment and Care for HIV (STRETCH) pragmatic randomised controlled trial. Methods: Developing the intervention: The intervention was developed following discussions with senior management, clinicians, and clinic staff. These discussions revealed that the establishment of separate antiretroviral treatment services for HIV had resulted in problems in accessing care due to the large number of patients at ART clinics. The intervention developed therefore combined the shifting from doctors to nurses of prescriptions of antiretrovirals (ARVs) for uncomplicated patients and the stepwise integration of HIV care into primary care services. Results: Components of the intervention: The intervention consisted of regulatory changes, training, and guidelines to support nurse ART prescription, local management teams, an implementation toolkit, and a flexible, phased introduction. Nurse supervisors were equipped to train intervention clinic nurses in ART prescription using outreach education and an integrated primary care guideline. Management teams were set up and a STRETCH coordinator was appointed to oversee the implementation process. Discussion: Three important processes were used in developing and implementing this intervention: active participation of clinic staff and local and provincial management, educational outreach to train nurses in intervention sites, and an external facilitator to support all stages of the intervention rollout

Healthy Parent Carers programme: mixed methods process evaluation and refinement of a health promotion intervention

This is the final version. Available on open access from the BMJ Publishing Group via the DOI in this recordData availability statement; Data are available upon reasonable request.OBJECTIVES: Parent carers of children with special educational needs or disability are at risk of poorer mental and physical health. In response to these needs, we codeveloped the 'Healthy Parent Carers' (HPC) programme. This study examined the views and experiences of participants in the HPC feasibility trial to inform programme refinement. INTERVENTION, SETTING AND PARTICIPANTS: HPC is a peer-led group-based intervention (supported by online materials) for primary carers of disabled children, encouraging behaviours linked with health and well-being. It was delivered by two lead and six assistant peer facilitators in six community sites (one lead and one assistant per group) in South West England over six or 12 sessions. Control participants had online materials only. The trial involved 47 intervention and 45 control parent carers (97% female and 97% white) and eight facilitators (one male). DESIGN: A preplanned mixed methods process evaluation using questionnaires and checklists (during and after the intervention), qualitative interviews with participants after intervention (n=18) and a focus group with facilitators after trial. RESULTS: HPC was highly acceptable to participants and facilitators and experiences were very positive. Participants reported that the programme increased awareness of what parent carers could and could not change and their self-efficacy to engage in health-promoting behaviours. The intended mechanisms of action (social identification and peer support) matched participants' expectations and experiences. Control participants found the online-only programme flexible but isolating, as there were no opportunities to share ideas and problem solve with peers, the key function of the programme. Areas for improvement were identified for programme content, facilitator training and delivery. CONCLUSION: HPC was acceptable, well received and offers considerable potential to improve the health of parent carers. Under the pandemic, the challenge going forward is how best to maintain reach and fidelity to function while delivering a more virtual programme. TRIAL REGISTRATION NUMBER: ISRCTN151144652.National Institute for Health Research (NIHR

Cancer cell differentiation heterogeneity and aggressive behavior in solid tumors

The differentiation stage of tumors is a central aspect in the histopathological classification of solid malignancies. The differentiation stage is strongly associated with tumor behavior, and generally an immature tumor is more aggressive than the more differentiated counterpart. While this is common knowledge in surgical pathology, the contribution of differentiation-related gene expression and functions to tumor behavior is often overlooked in the experimental, tumor biological setting. The mechanisms by which tumor cell differentiation stages are perturbed or affected are poorly explored but have recently come into focus with the introduction.of the tumor stem cell concept. While developmental biologists view the differentiation as a unidirectional event, pathologists and tumor biologists have introduced the concept of dedifferentiation to explain phenotypic changes occurring in solid tumors. In this review we discuss the impact of the tumor cell differentiation stage as used in surgical pathology. We further discuss knowledge gained from exploring the molecular basis of the differentiation and dedifferentiation processes in neuroblastoma and breast cancer, two tumor forms where the tumor cell differentiation concept is used in the clinical diagnostic work and where the tumor stem cell theory has been applied

Healthy Parent Carers: feasibility randomised controlled trial of a peer-led group-based health promotion intervention for parent carers of disabled children

This is the final version. Available on open access from BMC via the DOI in this record.Availability of data and materials: The datasets analysed during the current study are available from the corresponding author on reasonable request via Open Research Exeter: https://doi.org/10.24378/exe.3423.Background Parent carers of children with special educational needs or disability are at higher risk of poor mental and physical health. The need for a tailored, peer-led group programme was raised by parent carers, who co-developed the Healthy Parent Carers programme with researchers. This study aimed to test the feasibility of programme delivery in community settings, and the feasibility and acceptability of a randomised controlled trial design. Methods Participants were individually randomised with concealed allocation to a structured group programme and access to online resources (intervention), or access to the online resources only (control). Measures of wellbeing and secondary and economic outcomes were collected before randomisation, immediately post-intervention, and 6 months post-intervention. Descriptive statistics on recruitment and attrition, demographics, attendance, and fidelity of intervention delivery were analysed with feedback on the acceptability of the trial design. Results One hundred and ninety-three parent carers expressed an interest in taking part. Ninety-two participants recruited from across six sites were randomised (47 intervention, 45 control). Lead and assistant facilitators were trained and delivered the group sessions. Sixteen (34%) participants in the intervention arm did not attend any sessions, and attendance varied across sites and sessions. One participant withdrew post-randomisation, and 83 (90%) participants completed outcome measures at the six-month follow-up. Conclusions The study demonstrated that it was feasible to deliver the programme in community settings. The number of parent carers who expressed interest signifies the need for such a programme and the feasibility of recruiting to a definitive trial. Loss to follow-up was low. Further research is needed to explore ways to reduce barriers to participation in person and assess the feasibility and acceptability of programme content and delivery for more ethnically diverse groups, and potentially using interpreters. Given the Covid-19 pandemic and delivery format feedback, there is also a need to investigate remote or blended delivery strategies. Although the results indicate that a definitive trial is feasible, programme impact would be strengthened through exploration of these uncertainties.National Institute for Health Research (NIHR

Yeast diversity in relation to the production of fuels and chemicals

In addition to ethanol, yeasts have the potential to produce many other industrially-relevant chemicals from numerous different carbon sources. However there remains a paucity of information about overall capability across the yeast family tree. Here, 11 diverse species of yeasts with genetic backgrounds representative of different branches of the family tree were investigated. They were compared for their abilities to grow on a range of sugar carbon sources, to produce potential platform chemicals from such substrates and to ferment hydrothermally pretreated rice straw under simultaneous saccharification and fermentation conditions. The yeasts differed considerably in their metabolic capabilities and production of ethanol. A number could produce significant amounts of ethyl acetate, arabinitol, glycerol and acetate in addition to ethanol, including from hitherto unreported carbon sources. They also demonstrated widely differing efficiencies in the fermentation of sugars derived from pre-treated rice straw biomass and differential sensitivities to fermentation inhibitors. A new catabolic property of Rhodotorula mucilaginosa (NCYC 65) was discovered in which sugar substrate is cleaved but the products are not metabolised. We propose that engineering this and some of the other properties discovered in this study and transferring such properties to conventional industrial yeast strains could greatly expand their biotechnological utility