Investigation of shock waves in explosive blasts using fibre optic pressure sensors

The published version of this article may be accessed at the link below. Copyright @ IOP Publishing, 2006.We describe miniature all-optical pressure sensors, fabricated by wafer etching techniques, less than 1 mm(2) in overall cross-section with rise times in the mu s regime and pressure ranges typically 900 kPa (9 bar). Their performance is suitable for experimental studies of the pressure-time history for test models exposed to shocks initiated by an explosive charge. The small size and fast response of the sensors promises higher quality data than has been previously available from conventional electrical sensors, with potential improvements to numerical models of blast effects. Results from blast tests are presented in which up to six sensors were multiplexed, embedded within test models in a range of orientations relative to the shock front.Support from the UK Engineering&Physical Sciences Research Council and Dstl Fort Halstead through the MoD Joint Grants Scheme are acknowledged. WN MacPherson is supported by an EPSRC Advanced Research Fellowship

Truss geometry and topology optimization with global stability constraints

In this paper, we introduce geometry optimization into an existing topology optimization workflow for truss structures with global stability constraints, assuming a linear buckling analysis. The design variables are the cross-sectional areas of the bars and the coordinates of the joints. This makes the optimization problem formulations highly nonlinear and yields nonconvex semidefinite programming problems, for which there are limited available numerical solvers compared with other classes of optimization problems. We present problem instances of truss geometry and topology optimization with global stability constraints solved using a standard primal-dual interior point implementation. During the solution process, both the cross-sectional areas of the bars and the coordinates of the joints are concurrently optimized. Additionally, we apply adaptive optimization techniques to allow the joints to navigate larger move limits and to improve the quality of the optimal designs

Three-year survival of single- and two-surface ART restorations in a high-caries child population

The aim of this study was to evaluate the survival of single- and two-surface atraumatic restorative treatment (ART) restorations in the primary and permanent dentitions of children from a high-caries population, in a field setting. The study was conducted in the rainforest of Suriname, South America. ART restorations, made by four Dutch dentists, were evaluated after 6 months, 1, 2, and 3 years. Four hundred seventy-five ART restorations were placed in the primary dentition and 54 in first permanent molars of 194 children (mean age 6.09 ± 0.48 years). Three-year cumulative survivals of single- and two-surface ART restorations in the primary dentition were 43.4 and 12.2%, respectively. Main failure characteristics were gross marginal defects and total or partial losses. Three-year cumulative survival for single-surface ART restorations in the permanent dentition was 29.6%. Main failure characteristics were secondary caries and gross marginal defects. An operator effect was found only for two-surface restorations. The results show extremely low survival rates for single- and two-surface ART restorations in the primary and permanent dentitions. The variable success for ART may initiate further discussion about alternative treatment strategies, especially in those situations where choices have to be made with respect to a well-balanced, cost-effective package of basic oral health care

Prevalence of dementia and Alzheimer's disease in elders of nursing homes and a senior center of Durango City, Mexico

BACKGROUND: Epidemiological reports about dementia and Alzheimer's disease (AD) in elderly people from developing countries are scarce. Therefore, we sought to determine the prevalences of dementia and AD in a population of nursing home residents and senior center attendees of Durango City, Mexico, and to determine whether any socio-demographic characteristics from the subjects associated with dementia or AD exist. METHODS: One hundred and fifty-five residents of two nursing homes and 125 attendees of a senior center were examined for dementia and Alzheimer's disease. All subjects were tested by the mini-mental state examination, and those who scored twenty-four or less underwent psychiatric and neurological evaluations. Diagnosis of dementia, AD and vascular dementia (VaD) was based on the DSM-IV criteria. Socio-demographic characteristics from each participant were also obtained. RESULTS: Residents of nursing homes found to suffer from dementia were 25 out of 155 (16.1%). Eighteen of them (11.6%) had AD, and seven (4.5%) had VaD. None of the attendees of the senior center suffered from dementia. Dementia (pooled AD and VaD cases) correlated with white ethnicity (OR = 3.2; 95%CI = 1.28–8.31), and a history of unemployment (OR = 6.46; 95%CI = 1.42–25.97), while AD correlated with journeymen occupations (OR = 4.55; 95%CI = 1.00–19.29). CONCLUSION: Prevalence of dementia in residents of nursing homes found in this study is much lower than reported from more industrialized countries. AD was more frequent than VaD. Ethnicity and occupation showed effects on the prevalence figures. The prevalence of dementia found has implications for the optimum kind of health care that nursing homes should provide to their residents

Computational Insights on the Competing Effects of Nitric Oxide in Regulating Apoptosis

Despite the establishment of the important role of nitric oxide (NO) on apoptosis, a molecular- level understanding of the origin of its dichotomous pro- and anti-apoptotic effects has been elusive. We propose a new mathematical model for simulating the effects of nitric oxide (NO) on apoptosis. The new model integrates mitochondria-dependent apoptotic pathways with NO-related reactions, to gain insights into the regulatory effect of the reactive NO species N2O3, non-heme iron nitrosyl species (FeLnNO), and peroxynitrite (ONOO−). The biochemical pathways of apoptosis coupled with NO-related reactions are described by ordinary differential equations using mass-action kinetics. In the absence of NO, the model predicts either cell survival or apoptosis (a bistable behavior) with shifts in the onset time of apoptotic response depending on the strength of extracellular stimuli. Computations demonstrate that the relative concentrations of anti- and pro-apoptotic reactive NO species, and their interplay with glutathione, determine the net anti- or pro-apoptotic effects at long time points. Interestingly, transient effects on apoptosis are also observed in these simulations, the duration of which may reach up to hours, despite the eventual convergence to an anti-apoptotic state. Our computations point to the importance of precise timing of NO production and external stimulation in determining the eventual pro- or anti-apoptotic role of NO

Comparison of two related lines of tauGFP transgenic mice designed for lineage tracing

Abstract Background The tauGFP reporter fusion protein is produced nearly ubiquitously by the TgTP6.3 transgene in TP6.3 mice and its localisation to microtubules offers some advantages over soluble GFP as a lineage marker. However, TgTP6.3 Tg/Tg homozygotes are not viable and TgTP6.3 Tg/− hemizygotes are smaller than wild-type. TP6.4 mice carry the TgTP6.4 transgene, which was produced with the same construct used to generate TgTP6.3, so we investigated whether TgTP6.4 had any advantages over TgTP6.3. Results Although TgTP6.4 Tg/Tg homozygotes died before weaning, TgTP6.4 Tg/− hemizygotes were viable and fertile and only males were significantly lighter than wild-type. The TgTP6.4 transgene produced the tauGFP fusion protein by the 2-cell stage and it was widely expressed in adults but tauGFP fluorescence was weak or absent in several tissues, including some neural tissues. The TgTP6.4 transgene expression pattern changed over several years of breeding and mosaic transgene expression became increasingly common in all expressing tissues. This mosaicism was used to visualise clonal lineages in the adrenal cortex of TgTP6.4 Tg/− hemizygotes and these were qualitatively and quantitatively comparable to lineages reported previously for other mosaic transgenic mice, X-inactivation mosaics and chimaeras. Mosaicism occurred less frequently in TP6.3 than TP6.4 mice and was only observed in the corneal epithelium and adrenal cortex. Conclusions Mosaic expression makes the TgTP6.4 transgene unsuitable for use as a conventional cell lineage marker but such mosaicism provides a useful system for visualising clonal lineages that arise during development or maintenance of adult tissues. Differences in the occurrence of mosaicism between related transgenic lines, such as that described for lines TP6.3 and TP6.4, might provide a useful system for investigating the mechanism of transgene silencing

Angkringan Kopi Joss sebagai Daya Tarik Wisata Gastronomi Kota YOGYAKARTA dan Kondisinya Akibat Pandemi Covid-19

Salah satu budaya kuliner yang lekat dengan mahasiswa dan Yogyakarta adalah warung angkringan. Angkringan berasal dari bahasa jawa "angkring" yang berarti duduk santai dengan kaki di angkat di kursi (nangkring). Salah satu minuman yang khas di angkringan Kota Yogyakarta ini adalah Kopi Joss. Penyajian kopi hitam dengan memasukkan bara arang ke dalamnya dan menimbulkan bunyi “jooosss”, sehingga kopi ini terkenal dengan nama kopi joss. Munculnya wabah Covid-19 telah memberikan dampak buruk bagi usaha angkringan di Yogyakarta. Penelitian ini bertujuan untuk mengetahui faktor-faktor apa saja yang mempengaruhi daya tarik wisata gastronomi angkringan kopi joss di Kota Yogyakarta dan untuk mengetahui mitos terkait manfaat kopi joss. Survey lapangan dilakukan selama masa new normal. Penelitian ini bersifat deskriptif kuantitatif dengan pengolahan data primer dan sekunder. Data diperoleh melalui survey, wawancara, dan observasi. Alat analisis statistik yang digunakan untuk menjawab rumusan masalah adalah analisis regresi yang didukung dengan uji validitas dan reliabilitas. Hasil temuan dari penelitian ini terdapat lima faktor yang mempengaruhi minat wisata gastronomi angkringan kopi joss yaitu daya tarik, minuman, saran, julukan, dan Covid-19. Temuan kedua membuktikan bahwa mitos khasiat penambahan arang tidak hanya bermanfaat bagi tubuh tetapi wisatawan juga menyadari akan bahaya serta adanya kandungan senyawa karsinogenik pada arang yang dimasukkan dalam kopi joss. Hal itu tidak mengurangi minat wisatawan untuk menikmati kopi joss