707 research outputs found
What do we know about rail suicide incidents?: analysis of 257 fatalities on the rail network in Great Britain
There are over two hundred and fifty suicides on the railway in Great Britain (GB) each year. Descriptive statistics are compiled, producing national and international data. The industry know how many and, to a limited extent, where these fatalities occur. There is little in-depth analysis of events. Therefore, there are gaps in knowledge of these fatalities and this is a weakness when considering the best approaches to prevention. This paper reports on the analysis of data on 257 suicide events at or near to 51 stations on three rail routes in Great Britain over a 20 year period. The analysis uses data from the industry Safety Management System (SMIS) database and produces simple descriptive statistics on a range of variables, including comparisons across the three rail routes. Additional data from staff and route based documentation have been used to verify, supplement and interpret information in the database. Examples of patterns of immediate and precursor behaviours during incidents have been presented, illustrating the potential to explore both common and anomalous behaviours during events. The findings demonstrate the type of content that can be explored within the industry data and through use of other data that are available within the industry. Commentary is provided on the strengths and weaknesses of the data and how findings from the analysis can be used to improve future data collection and prevention of incidents
How to bring a technical artifact into use: A micro-developmental perspective
In order to understand how technical artifacts are attuned to, interacted with, and
shaped in various and varied classrooms, it is necessary to construct detailed accounts of the
use of particular artifacts in particular classrooms. This paper presents a descriptive account of
how a shared workspace was brought into use by a student pair in a face-to-face planning task.
A micro-developmental perspective was adopted to describe how the pair established a
purposeful connection with this unfamiliar artifact over a relatively short time frame. This
appropriation was examined against the background of their regular planning practice. We
describe how situational resources present in the classroom—norms, practices and artifacts—
frame possible action, and how these possibilities are enacted by the pair. Analysis shows that
the association of norms and practices with the technical artifact lead to a contradiction that
surfaced as resistance experienced from the artifact. This resistance played an important part in
the appropriation process of the pair. It signaled tension in the activity, triggered reflection on
the interaction with the artifact, and had a coordinative function. The absence of resistance was
equally important. It allowed the pair to transpose or depart from regular procedure without
reflection
Методика проектирования и технологическая схема повторной ликвидации наклонных стволов закрытых угольных шахт
На основе аналитических и технологических исследований разработаны методика
проектирования и технологическая схема повторной ликвидации наклонных выработок
закрытых шахт способом тампонажа ресурсосберегающими безусадочными смесями.
Технология позволяет обеспечить геомеханическую устойчивость породного массива
Development and evaluation of a novel contamination device that targets multiple life-stages of Aedes aegypti.
BACKGROUND: The increasing global threat of Dengue demands new and easily applicable vector control methods. Ovitraps provide a low-tech and inexpensive means to combat Dengue vectors. Here we describe the development and optimization process of a novel contamination device that targets multiple life-stages of the Aedes aegypti mosquito. Special focus is directed to the diverse array of control agents deployed in this trap, covering adulticidal, larvicidal and autodissemination impacts. METHODS: Different trap prototypes and their parts are described, including a floater to contaminate alighting gravid mosquitoes. The attractiveness of the trap, different odor lures and floater design were studied using fluorescent powder adhering to mosquito legs and via choice tests. We demonstrate the mosquitocidal impacts of the control agents: a combination of the larvicide pyriproxyfen and the adulticidal fungus Beauveria bassiana. The impact of pyriproxyfen was determined in free-flight dissemination experiments. The effect on larval development inside the trap and in surrounding breeding sites was measured, as well as survival impacts on recaptured adults. RESULTS: The developmental process resulted in a design that consists of a black 3 Liter water-filled container with a ring-shaped floater supporting vertically placed gauze dusted with the control agents. On average, 90% of the mosquitoes in the fluorescence experiments made contact with the gauze on the floater. Studies on attractants indicated that a yeast-containing tablet was the most attractive odor lure. Furthermore, the fungus Beauveria bassiana was able to significantly increase mortality of the free-flying adults compared to controls. Dissemination of pyriproxyfen led to >90% larval mortality in alternative breeding sites and 100% larval mortality in the trap itself, against a control mortality of around 5%. CONCLUSION: This ovitrap is a promising new tool in the battle against Dengue. It has proven to be attractive to Aedes aegypti mosquitoes and effective in contaminating these with Beauveria bassiana. Furthermore, we show that the larvicide pyriproxyfen is successfully disseminated to breeding sites close to the trap. Its low production and operating costs enable large scale deployment in Dengue-affected locations
Constraining the long-term evolution of the slip rate for a major extensional fault system in the central Aegean, Greece, using thermochronology
The brittle/ductile transition is a major rheologic boundary in the crust yet little is known about how or if rates of tectonic processes are influenced by this boundary. In this study we examine the slip history of the large-scale Naxos/Paros extensional fault system (NPEFS), Cyclades, Greece, by comparing published slip rates for the ductile crust with new thermochronological constraints on slip rates in the brittle regime. Based on apatite and zircon fission-track (AFT and ZFT) and (U–Th)/He dating we observe variable slip rates across the brittle/ductile transition on Naxos. ZFT and AFT ages range from 11.8 ± 0.8 to 9.7 ± 0.8 Ma and 11.2 ± 1.6 to 8.2 ± 1.2 Ma and (U–Th)/He zircon and apatite ages are between 10.4 ± 0.4 to 9.2 ± 0.3 Ma and 10.7 ± 1.0 to 8.9 ± 0.6 Ma, respectively. On Paros, ZFT and AFT ages range from 13.1 ± 1.4 Ma to 11.1 ± 1.0 Ma and 12.7 ± 2.8 Ma to 10.5 ± 2.0 Ma while the (U–Th)/He zircon ages are slightly younger between 8.3 ± 0.4 Ma and 9.8 ± 0.3 Ma. All ages consistently decrease northwards in the direction of hanging wall transport. Most of our new thermochronological results and associated thermal modeling more strongly support the scenario of an identical fault dip and a constant or slightly accelerating slip rate of 6–8 km Myr− 1 on the NPEFS across the brittle/ductile transition. Even the intrusion of a large granodiorite body into the narrowing fault zone at 12 Ma on Naxos does not seem to have affected the thermal structure of the area in a way that would significantly disturb the slip rate. The data also show that the NPEFS accomplished a minimum total offset of 50 km between 16 and 8 Ma
Ga+, In+ and Tl+ Impurities in Alkali Halide Crystals: Distortion Trends
A computational study of the doping of alkali halide crystals (AX: A = Na, K;
X = Cl, Br) by ns2 cations (Ga+, In+ and Tl+) is presented. Active clusters of
increasing size (from 33 to 177 ions) are considered in order to deal with the
large scale distortions induced by the substitutional impurities. Those
clusters are embedded in accurate quantum environments representing the
surrounding crystalline lattice. The convergence of the distortion results with
the size of the active cluster is analyced for some selected impurity systems.
The most important conclusion from this study is that distortions along the
(100) and (110) crystallographic directions are not independent. Once a
reliable cluster model is found, distortion trends as a function of impurity,
alkali cation and halide anion are identified and discussed. These trends may
be useful when analycing other cation impurities in similar host lattices.Comment: LaTeX file. 7 pages and 2 pictures. Accepted for publication in J.
Chem. Phy
Hard-to-heal venous-lymphatic leg ulcers: a special case
In the treatment of this 56-year-old male, the aim was to attend to his multiple pathologies, reducing his venous-lymphatic oedema on both legs, closing the extended ulcers and improving his quality of life. The patient received treatment in a community-based wound healing clinic. After various local therapies were not successful, the wounds were cleansed with saline and covered with a biocellulose dressing (BWD) and polyhexanide (PHMB), after which a short-stretch bandage system was applied. Compression was then switched to a tubular compression system. At day 0, both lower legs had significant oedema and circumferential venous-lymphatic ulcers, and the left leg showed signs of inflammation. However, at day 8, inflammation, oedema and ulcer area had reduced. After 2 months, the ulcers were almost closed and the oedema had reduced to a level where the tubular compression system could be applied. Treatment using BWD and compression and good adherence to this regimen led to ulcer closure. This improved the patients' quality of life significantly
Landscape evolution of the Apurimac river drainage basin, southern Peru
The northernmost part of the Altiplano in Southern Peru is drained by the river Apurimac and its tributaries. The Altiplano is a region that covers most of the eastern part of the Cordillera Occidental and is bounded in the East by the Cordillera Oriental. The Apurirnac River Drainage Basin (ARDB) extends roughly between 13 °S and l5°S over 50000 km 2. It mainly occupies the northeastern flank of the Cordillera Occidental and a negligible part of the southwestern flank of the Cordillera Oriental. At the latitude of the Abancay deflection, i.e. 13.5 S; 72.7 W, the Apurirnac River abandons the Cordillera Occidental. On its way to the Amazon Basin in the North the Apurimac River drains the Cordillera Oriental and the Sub-Andean Zone (SAZ). The incision by the rivers of the ARDB has created differences in relief of more than 2000 m that contributed to the denudation and exhumation, hence the evolution ofthe landscape. The Altiplano sedimentary basin contains an 8 kilometers thick succession of Cenozoic sediments, which it received from the surrounding highs in the West and the Easl Its structural framework has been formed by the various tectonic events that struck the Andes and the various pulses of magmatic activity that took place during the Cenozoic. In the western part of the Altiplano Miocene volcanics domínate, whereas in the northeastern part, in the Cusco region, clastic deposits do so. In the region of Abancay, a batholite got emplaced during the mid Tertiary, that extends over few 1000 km2
Pre-ataxic loss of intrinsic plasticity and motor learning in a mouse model of SCA1
Spinocerebellar ataxias are neurodegenerative diseases, the hallmark symptom of which is the development of ataxia due to cerebellar dysfunction. Purkinje cells, the principal neurons of the cerebellar cortex, are the main cells affected in these disorders, but the sequence of pathological events leading to their dysfunction is poorly understood. Understanding the origins of Purkinje cells dysfunction before it manifests is imperative to interpret the functional and behavioural consequences of cerebellar-related disorders, providing an optimal timeline for therapeutic interventions. Here, we report the cascade of events leading to Purkinje cells dysfunction before the onset of ataxia in a mouse model of spinocerebellar ataxia 1 (SCA1). Spatiotemporal characterization of the ATXN1[82Q] SCA1 mouse model revealed high levels of the mutant ATXN1[82Q] weeks before the onset of ataxia. The expression of the toxic protein first caused a reduction of Purkinje cells intrinsic excitability, which was followed by atrophy of Purkinje cells dendrite arborization and aberrant glutamatergic signalling, finally leading to disruption of Purkinje cells innervation of climbing fibres and loss of intrinsic plasticity of Purkinje cells. Functionally, we found that deficits in eyeblink conditioning, a form of cerebellum-dependent motor learning, precede the onset of ataxia, matching the timeline of climbing fibre degeneration and reduced intrinsic plasticity. Together, our results suggest that abnormal synaptic signalling and intrinsic plasticity during the pre-ataxia stage of spinocerebellar ataxias underlie an aberrant cerebellar circuitry that anticipates the full extent of the disease severity. Furthermore, our work indicates the potential for eyeblink conditioning to be used as a sensitive tool to detect early cerebellar dysfunction as a sign of future disease.</p
Theory of hyperfine interactions in positive ions isoelectronic with the noble-metal atoms
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