271 research outputs found

    AGE Survey: a tool to support the study and intervention on health and age at work

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    The complex relationship between age and work goes beyond the association between the exposure to risk factors and early ageing. Only few studies attempt to encompass this complexity and try to put this discussion in a temporal dimension, considering the developments of health and work over lifetime. This proposal presents some results of a study conducted in Portugal about working conditions, occupational risks and health problems. European studies, as ESTEV and VISAT, both in France, used a longitudinal design with repeated measures in order to monitor health issues taking into account job modifications and age evolution. From these experiences, other studies were performed in this field, with less extensive instruments, for example the SVP50 and EVREST. In Portugal we developed the first survey on health and age – AGE– based on the previous experiences and supported by the strong network between researchers from these groups. The first AGE data collection was conducted in 2016, in collaboration with the National Authority for Working Conditions. The survey was administrated by labour inspectors in their regular visits to companies, with 3106 surveyed workers. AGE dimensions focus on: working conditions (working time, schedules, demands/resources, perceived risks); health complaints and the perceived (by workers) relationship between these problems and their work, in order to analyse the relationship between age, health and work; and questions about retirement expectations, in order to identify retirement predictors. The results show interesting relations between working conditions and the health problems identified by workers and, with strong evidences that age plays a key role in the capacity to recognise the connexion between work constraints and health problems. Results also show different tendencies related to both perceived expositions and perceived health problems for different age groups, emphasising the need to consider the specificity of diverse situations in the moment of intervention. Findings also show that these health problems are frequently reported by workers, as related to their work, mostly in work situations of co-exposition (when workers are exposed to several constrains at the same time). The association of different constraints seem to be particularly hard for workers, due to the high proportion of reported health problems.info:eu-repo/semantics/acceptedVersio

    Population dynamics and life history of the rare arctic- alpine plant Sagina nivalis (Caryophyllaceae) on the Ben Lawers range, Scotland, UK

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    The flora of Scotland's mountains is of international significance as it contains arctic-alpine species at the edge of their global range. Such rear edge populations deserve high priority investigation due to their unique local adaptations, important conservation value and because montane plants may be particularly sensitive to environmental change. Sagina nivalis is one of the rarest and least known arctic-alpines in Britain and the vast majority of plants occur within the Ben Lawers SSSI. Ten permanent plots were surveyed here from 1982-1994 by counting the number of plants and tagging and measuring individuals throughout the duration of their lives. The total number of plants present at each colony across the whole site was also recorded in 1996 and 2014. Extreme fluctuations in numbers occurred within periods of very few years and were associated with the fragile and dynamic nature of the montane habitat. Seedling mortality was very high, but age had no effect on survival rates once plants were one year old. Most were small, only lived two years and produced none or few flowers, although those that survived long enough generally reached their maximum size and flowering potential when they were five years old. The number of plants present across the whole of Ben Lawers halved between 1996 and 2014, with half of all colonies extinct and a further third in significant decline. The greatest threats to S. nivalis in Scotland were identified as habitat damage due to natural processes, sheep activity and climate change. A reduction in snow cover may cause an interaction between these factors and compromise the long-term survival of rear edge populations of this species, other rare arctic-alpines in Scotland and their associated contribution to biodiversity

    A Brief Review on Dark Matter Annihilation Explanation for e±e^\pm Excesses in Cosmic Ray

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    Recently data from PAMELA, ATIC, FERMI-LAT and HESS show that there are e±e^{\pm} excesses in the cosmic ray energy spectrum. PAMELA observed excesses only in e+e^+, but not in anti-proton spectrum. ATIC, FERMI-LAT and HESS observed excesses in e++ee^++e^- spectrum, but the detailed shapes are different which requires future experimental observations to pin down the correct data set. Nevertheless a lot of efforts have been made to explain the observed e±e^\pm excesses, and also why PAMELA only observed excesses in e+e^+ but not in anti-proton. In this brief review we discuss one of the most popular mechanisms to explain the data, the dark matter annihilation. It has long been known that about 23% of our universe is made of relic dark matter. If the relic dark matter was thermally produced, the annihilation rate is constrained resulting in the need of a large boost factor to explain the data. We will discuss in detail how a large boost factor can be obtained by the Sommerfeld and Briet-Wigner enhancement mechanisms. Some implications for particle physics model buildings will also be discussed.Comment: 22 pages, 6 figures. Several typoes corrected and some references added. Published in Mod. Phys. Lett. A, Vol. 24, No. 27 (2009) pp. 2139-216

    Parenting interventions for male young offenders: a review of the evidence on what works

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    Approximately one in four incarcerated male young offenders in the UK is an actual or expectant father. This paper reviews evidence on the effectiveness of parenting interventions for male young offenders. We conducted systematic searches across 20 databases and consulted experts. Twelve relevant evaluations were identified: 10 from the UK, of programmes for incarcerated young offenders, and two from the US, of programmes for young parolees. None used experimental methods or included a comparison group. They suggest that participants like the courses, find them useful, and the interventions may improve knowledge about, and attitudes to, parenting. Future interventions should incorporate elements of promising parenting interventions with young fathers in the community, for example, and/or with older incarcerated parents. Young offender fathers have specific developmental, rehabilitative, and contextual needs. Future evaluations should collect longer-term behavioural parent and child outcome data and should use comparison groups and, ideally, randomization

    Two component dark matter

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    We explain the PAMELA positron excess and the PPB-BETS/ATIC e+ + e- data using a simple two component dark matter model (2DM). The two particle species in the dark matter sector are assumed to be in thermal equilibrium in the early universe. While one particle is stable and is the present day dark matter, the second one is metastable and decays after the universe is 10^-8 s old. In this model it is simple to accommodate the large boost factors required to explain the PAMELA positron excess without the need for large spikes in the local dark matter density. We provide the constraints on the parameters of the model and comment on possible signals at future colliders.Comment: 6 pages, 2 figures, discussion clarified and extende

    Absolute electron and positron fluxes from PAMELA/Fermi and Dark Matter

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    We extract the positron and electron fluxes in the energy range 10 - 100 GeV by combining the recent data from PAMELA and Fermi LAT. The {\it absolute positron and electron} fluxes thus obtained are found to obey the power laws: E2.65E^{-2.65} and E3.06E^{-3.06} respectively, which can be confirmed by the upcoming data from PAMELA. The positron flux appears to indicate an excess at energies E\gsim 50 GeV even if the uncertainty in the secondary positron flux is added to the Galactic positron background. This leaves enough motivation for considering new physics, such as annihilation or decay of dark matter, as the origin of positron excess in the cosmic rays.Comment: Accepted by JCA

    Snowmass CF1 Summary: WIMP Dark Matter Direct Detection

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    As part of the Snowmass process, the Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The charge to CF1 was (a) to summarize the current status and projected sensitivity of WIMP direct detection experiments worldwide, (b) motivate WIMP dark matter searches over a broad parameter space by examining a spectrum of WIMP models, (c) establish a community consensus on the type of experimental program required to explore that parameter space, and (d) identify the common infrastructure required to practically meet those goals.Comment: Snowmass CF1 Final Summary Report: 47 pages and 28 figures with a 5 page appendix on instrumentation R&

    Decaying into the Hidden Sector

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    The existence of light hidden sectors is an exciting possibility that may be tested in the near future. If DM is allowed to decay into such a hidden sector through GUT suppressed operators, it can accommodate the recent cosmic ray observations without over-producing antiprotons or interfering with the attractive features of the thermal WIMP. Models of this kind are simple to construct, generic and evade all astrophysical bounds. We provide tools for constructing such models and present several distinct examples. The light hidden spectrum and DM couplings can be probed in the near future, by measuring astrophysical photon and neutrino fluxes. These indirect signatures are complimentary to the direct production signals, such as lepton jets, predicted by these models.Comment: 40 pages, 5 figure

    Transformation kinetics of alloys under non-isothermal conditions

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    The overall solid-to-solid phase transformation kinetics under non-isothermal conditions has been modeled by means of a differential equation method. The method requires provisions for expressions of the fraction of the transformed phase in equilibrium condition and the relaxation time for transition as functions of temperature. The thermal history is an input to the model. We have used the method to calculate the time/temperature variation of the volume fraction of the favored phase in the alpha-to-beta transition in a zirconium alloy under heating and cooling, in agreement with experimental results. We also present a formulation that accounts for both additive and non-additive phase transformation processes. Moreover, a method based on the concept of path integral, which considers all the possible paths in thermal histories to reach the final state, is suggested.Comment: 16 pages, 7 figures. To appear in Modelling Simul. Mater. Sci. En

    Pseudomoduli Dark Matter and Quiver Gauge Theories

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    We investigate supersymmetric models for dark matter which is represented by pseudomoduli in weakly coupled hidden sectors. We propose a scheme to add a dark matter sector to quiver gauge theories with metastable supersymmetry breaking. We discuss the embedding of such scheme in string theory and we describe the dark matter sector in terms of D7 flavour branes. We explore the phenomenology in various regions of the parameters.Comment: 24 pages, 12 figures, JHEP3.cl
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