48,254 research outputs found
The actors that shape the knowledge, attitudes and behaviour of Maltese youth
Not much is known about the environmental knowledge, attitudes and actions of young people in the
Maltese islands. The main actors that are responsible for the acquisition and development of
environmental perspectives in young people in Malta are also not well known. There is as yet, little
understanding of the extent to which these actors are fostering a sense of environmental responsibility
and a greater commitment towards sustainable development.
A mixed method research methodology was employed to address this knowledge gap that included an
extended questionnaire distributed to students in the post secondary age range and a number of focus
groups to provide a more in-depth study of some of the issues arising from the questionnaire
analyses. The focus groups allowed young people to frame their responses in their own words. This
paper focuses on the results of the quantitative study.
The data from the quantitative analyses indicates that students are more knowledgeable about the
Global Environment than about the Local Environment, and that students receive most information
from School, Television and the Internet. The sources of environmental information which were
perceived by young people as being the most reliable included School, Books and the Internet. The
overall attitude of students towards the environment appears to be strongly positive, however students
seem to perform little positive actions towards the environment. Year group, Age and Gender were
found to have a statistically significant effect on knowledge; Father’s work was found to have a
statistically significant effect on attitude and Age was found to have a significant effect on behavior.peer-reviewe
Determining Ratios of WIMP-Nucleon Cross Sections from Direct Dark Matter Detection Data
Weakly Interacting Massive Particles (WIMPs) are one of the leading
candidates for Dark Matter. So far the usual procedure for constraining the
WIMP-nucleon cross sections in direct Dark Matter detection experiments have
been to fit the predicted event rate based on some model(s) of the Galactic
halo and of WIMPs to experimental data. One has to assume whether the
spin-independent (SI) or the spin-dependent (SD) WIMP-nucleus interaction
dominates, and results of such data analyses are also expressed as functions of
the as yet unknown WIMP mass. In this article, I introduce methods for
extracting information on the WIMP-nucleon cross sections by considering a
general combination of the SI and SD interactions. Neither prior knowledge
about the local density and the velocity distribution of halo WIMPs nor about
their mass is needed. Assuming that an exponential-like shape of the recoil
spectrum is confirmed from experimental data, the required information are only
the measured recoil energies (in low energy ranges) and the number of events in
the first energy bin from two or more experiments.Comment: 33 pages, 20 eps figures; v2: typos fixed, references added and
updated, revised version for publicatio
On Approximating the Number of -cliques in Sublinear Time
We study the problem of approximating the number of -cliques in a graph
when given query access to the graph.
We consider the standard query model for general graphs via (1) degree
queries, (2) neighbor queries and (3) pair queries. Let denote the number
of vertices in the graph, the number of edges, and the number of
-cliques. We design an algorithm that outputs a
-approximation (with high probability) for , whose
expected query complexity and running time are
O\left(\frac{n}{C_k^{1/k}}+\frac{m^{k/2}}{C_k}\right)\poly(\log
n,1/\varepsilon,k).
Hence, the complexity of the algorithm is sublinear in the size of the graph
for . Furthermore, we prove a lower bound showing that
the query complexity of our algorithm is essentially optimal (up to the
dependence on , and ).
The previous results in this vein are by Feige (SICOMP 06) and by Goldreich
and Ron (RSA 08) for edge counting () and by Eden et al. (FOCS 2015) for
triangle counting (). Our result matches the complexities of these
results.
The previous result by Eden et al. hinges on a certain amortization technique
that works only for triangle counting, and does not generalize for larger
cliques. We obtain a general algorithm that works for any by
designing a procedure that samples each -clique incident to a given set
of vertices with approximately equal probability. The primary difficulty is in
finding cliques incident to purely high-degree vertices, since random sampling
within neighbors has a low success probability. This is achieved by an
algorithm that samples uniform random high degree vertices and a careful
tradeoff between estimating cliques incident purely to high-degree vertices and
those that include a low-degree vertex
Deriving a systematic approach to changeable manufacturing system design
It has long been argued that Factories are long life and complex products. The complexity of designing factories, and their underlying manufacturing systems, is further amplified when dealing with continuously changing customer demands. At the same time, due to research fragmentation, little if any scientific explanations are available supporting and exploiting the paradigm that "factories are products". In order to address this weakness, this paper presents research results arising from a comparative analysis of systematic "product design" and "manufacturing system design" approaches. The contribution emerging from this research is an integrated systematic design approach to changeable manufacturing systems, based on scientific concepts founded upon product design theories, and is explained through a case study in the paper. This research is part of collaboration between the CERU University of Malta and IAO Fraunhofer aimed at developing a digital decision support tool for planning changeable manufacturing systems.peer-reviewe
Deaths certified as asthma and use of medical services: A national case-control study
This is an open access publication. The official published version can be accessed from the link below.Background: Studies have linked asthma death to either increased or decreased use of medical services.
Methods: A population based case-control study of asthma deaths in 1994–8 was performed in 22 English, six Scottish, and five Welsh health authorities/boards. All 681 subjects who died were under the age of 65 years with asthma in Part I on the death certificates. After exclusions, 532 hospital controls were matched to 532 cases for age, district, and date of asthma admission/death. Data were extracted blind from primary care records.
Results: The median age of the subjects who died was 53 years; 60% of cases and 64% of controls were female. There was little difference in outpatient attendance (55% and 55%), hospital admission for asthma (51% and 54%), and median inpatient days (20 days and 15 days) in the previous 5 years. After mutual adjustment and adjustment for sex, using conditional logistic regression, three variables were independently associated with asthma death: fewer general practice contacts (odds ratio 0.82 (95% confidence interval (CI) 0.74 to 0.91) per 5 contacts) in the previous year, more home visits (1.14 (95% CI 1.08 to 1.21) per visit) in the previous year, and fewer peak expiratory flow recordings (0.83 (95% CI 0.74 to 0.92) per occasion) in the previous 3 months. These associations were similar after adjustment for markers of severity, psychosocial factors, systemic steroids, short acting bronchodilators and antibiotics, although the association with peak flow was weakened and just lost significance.
Conclusion: Asthma death is associated with less use of primary care services. Both practice and patient factors may be involved and a better understanding of these may offer possibilities for reducing asthma death.This study was funded jointly between the National Research and Development Asthma Management Programme (contract number AM1/
05/002) and the National Asthma Campaign through a grant from Glaxo Wellcome (now GlaxoSmithKline)
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Rereading the Universal Declaration of Human Rights: plurality and contestation, not consensus
In this paper I examine the drafting of the Universal Declaration of Human Rights. My analysis counters conventional narratives of consensus and imposition that characterize the development of the UN human rights regime. The central argument is that within the founding text of the contemporary human rights movement there is an ambiguous account of rights, which exceeds easy categorization of international rights as universal moral principles or merely an ideological imposition by liberal powers. Acknowledging this ambiguous history, I argue, opens the way to an understanding of human rights as an ongoing politics, a contestation over the terms of legitimate political authority and the meaning of “humanity” as a political identity
Constriction size distributions of granular filters: a numerical study
The retention capability of granular filters is controlled by the narrow constrictions connecting the voids within the filter. The theoretical justification for empirical filter rules used in practice includes consideration of an idealised soil fabric in which constrictions form between co-planar combinations of spherical filter particles. This idealised fabric has not been confirmed by experimental or numerical observations of real constrictions. This paper reports the results of direct, particle-scale measurement of the constriction size distribution (CSD) within virtual samples of granular filters created using the discrete-element method (DEM). A previously proposed analytical method that predicts the full CSD using inscribed circles to estimate constriction sizes is found to poorly predict the CSD for widely graded filters due to an over-idealisation of the soil fabric. The DEM data generated are used to explore quantitatively the influence of the coefficient of uniformity, particle size distribution and relative density of the filter on the CSD. For a given relative density CSDs form a narrow band of similarly shaped curves when normalised by characteristic filter diameters. This lends support to the practical use of characteristic diameters to assess filter retention capability
Logic programming in the context of multiparadigm programming: the Oz experience
Oz is a multiparadigm language that supports logic programming as one of its
major paradigms. A multiparadigm language is designed to support different
programming paradigms (logic, functional, constraint, object-oriented,
sequential, concurrent, etc.) with equal ease. This article has two goals: to
give a tutorial of logic programming in Oz and to show how logic programming
fits naturally into the wider context of multiparadigm programming. Our
experience shows that there are two classes of problems, which we call
algorithmic and search problems, for which logic programming can help formulate
practical solutions. Algorithmic problems have known efficient algorithms.
Search problems do not have known efficient algorithms but can be solved with
search. The Oz support for logic programming targets these two problem classes
specifically, using the concepts needed for each. This is in contrast to the
Prolog approach, which targets both classes with one set of concepts, which
results in less than optimal support for each class. To explain the essential
difference between algorithmic and search programs, we define the Oz execution
model. This model subsumes both concurrent logic programming
(committed-choice-style) and search-based logic programming (Prolog-style).
Instead of Horn clause syntax, Oz has a simple, fully compositional,
higher-order syntax that accommodates the abilities of the language. We
conclude with lessons learned from this work, a brief history of Oz, and many
entry points into the Oz literature.Comment: 48 pages, to appear in the journal "Theory and Practice of Logic
Programming
Exploring the phase space of multiple states in highly turbulent Taylor-Couette flow
We investigate the existence of multiple turbulent states in highly turbulent
Taylor-Couette flow in the range of to ,
by measuring the global torques and the local velocities while probing the
phase space spanned by the rotation rates of the inner and outer cylinder. The
multiple states are found to be very robust and are expected to persist beyond
. The rotation ratio is the parameter that most strongly
controls the transitions between the flow states; the transitional values only
weakly depend on the Taylor number. However, complex paths in the phase space
are necessary to unlock the full region of multiple states. Lastly, by mapping
the flow structures for various rotation ratios in a Taylor-Couette setup with
an equal radius ratio but a larger aspect ratio than before, multiple states
were again observed. Here, they are characterized by even richer roll structure
phenomena, including, for the first time observed in highly turbulent TC flow,
an antisymmetrical roll state.Comment: 9 pages, 7 figure
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