6,815 research outputs found
GOVERNMENT REVENUES AND EXPENDITURES IN GUINEA-BISSAU: CAUSALITY AND COINTEGRATION
The paper establishes empirically the temporal causality and long run relationship between government expenditures and government revenues for the case of Guinea-Bissau - a low income country under stress (LICUS) in Africa. A macroeconomic model is developed to lay out the hypothesis of a spend-tax behavior in the country¡¯s public finances management system. Empirical validation is carried out by means of a traditional Granger-causality test and the estimation of an error correction model between expenditures and revenues.Public Finances, Causality Tests, Cointegration Analysis
Categorical Groups, Knots and Knotted Surfaces
We define a knot invariant and a 2-knot invariant from any finite categorical
group. We calculate an explicit example for the Spun Trefoil.Comment: 40 pages, lots of figures. Second version: Added example and
discussion, clarification of the fact that the maps associated with
Reidemeister Moves are well define
Genetic diversity of Lusitano horse in Brazil using pedigree information
This study aimed to evaluate population parameters and to describe the genetic diversity of the Lusitano
breed in Brazil using pedigree data. Two populations were evaluated: total population (TP) containing
18,922 animals, and reference population (RP) composed of a part of TP containing 8,329 animals, representing
the last generation. The generation interval (10.1 ± 5.1 years) was in the range for horse populations.
Pedigree completeness in RP shows almost 100% filling in the three most recent generations,
indicating improvement in the pedigree data and accuracy of the results, and the inbreeding coefficient
(4.46%) and average relatedness (5.97%) for RP, indicating control on the part of breeders. The effective
population size was 89 (TP) and 90 (RP). The effective number of founders (fe) were 33 and 29, effective
number of ancestors (fa) were 30 and 26, and effective number of founder genomes (fg) were 19 and 15 for
TP and RP, respectively, indicating a reduction of genetic variability in the last generations. The total
number of ancestors that explains 100% of the genetic diversity in the Lusitano breed in Brazil was 427 (TP)
and 341 (RP). The reproductive parameters, probabilities of gene origin showing loss of variability in the
last generations, and the genetic contributions of ancestors suggest the need to monitor genetic diversity
over time in breeding programs to allow control of the next generations and to increase their variability.info:eu-repo/semantics/publishedVersio
Working conditions and health complaints in urban refuse collection: the role of experience
The growing attention given to Occupational Health and Safety (OHS) has contributed to the general decline of work accidents in the most part of European countries in last century (Hofmann, Burke, & Zohar, 2017). Despite that, according to Portuguese official data (MTSSS, 2016; Eurostat, 2016), accompanying the economic recovery, we witnessed a slight increase of accidents incidence rate (4.415 in 2013, 4.523 in 2014 and 4.582 in 2015). This corresponds to a total of 5.459.744 (in 2015) lost working days, not considering the lost working days due to work-related diseases. For that reason, OHS is a huge concern for organizations, with strong impacts on costs, productivity or turnover (Malek, El-Safty, El-Safety, & Sorce, 2010); and for workers, in their quality of life (Keogh, Nuwayhid, Gordon, & Gucer, 2000), in their social interaction (Strunin & Boden, 2004), and also in their financial stability (Lawrence, Paustian-Underdahl, & Halbesleben, 2013) and work ability. This proposal describes an action-research, based on a demand from a specific organization (a public company of urban refuse collection and other municipality services) with a high rate of work-related accidents and health complaints, which aims to understand the factors that can explain this situation. Following the theoretical background of work psychology and ergonomics, we designed a mixed method approach centred on workers’ activity (Béguin, 2006; Schwartz, 2005), to investigate the demands, constraints and risk factors that characterize this work situation. The methodology includes documental analysis, observation, individual interviews and a questionnaire, giving special emphasis to the diversity of “ways of doing” the activity among different workers, teams and waste collection modes. Data analysis is currently being conducted, through qualitative (content analysis) and quantitative techniques. Preliminary findings indicate some interesting differences associated with the specific activity of workers – drivers and collectors – showing that it has implications on the type of risk exposure, nature of accidents, and health complaints. Also, results show that workers’ experience seems to influence the way of performing the activity, highlighting the development of health protection strategies over time.info:eu-repo/semantics/acceptedVersio
Non-universal behavior for aperiodic interactions within a mean-field approximation
We study the spin-1/2 Ising model on a Bethe lattice in the mean-field limit,
with the interaction constants following two deterministic aperiodic sequences:
Fibonacci or period-doubling ones. New algorithms of sequence generation were
implemented, which were fundamental in obtaining long sequences and, therefore,
precise results. We calculate the exact critical temperature for both
sequences, as well as the critical exponent , and . For
the Fibonacci sequence, the exponents are classical, while for the
period-doubling one they depend on the ratio between the two exchange
constants. The usual relations between critical exponents are satisfied, within
error bars, for the period-doubling sequence. Therefore, we show that
mean-field-like procedures may lead to nonclassical critical exponents.Comment: 6 pages, 7 figures, to be published in Phys. Rev.
A model for shock wave chaos
We propose the following model equation:
that predicts chaotic shock waves.
It is given on the half-line and the shock is located at for any
. Here is the shock state and the source term is assumed
to satisfy certain integrability constraints as explained in the main text. We
demonstrate that this simple equation reproduces many of the properties of
detonations in gaseous mixtures, which one finds by solving the reactive Euler
equations: existence of steady traveling-wave solutions and their instability,
a cascade of period-doubling bifurcations, onset of chaos, and shock formation
in the reaction zone.Comment: 4 pages, 4 figure
USING EXERGY LOSS PROFILES AND ENTHALPY-TEMPERATURE PROFILES FOR THE EVALUATION OF THERMODYNAMIC EFFICIENCY IN DISTILLATION COLUMNS
In this work the temperature-enthalpy profile and the exergy loss profile are used together
to improve thermodynamic efficiency of distillation columns, by identifying possible
benefits of using side exchangers. The method proposed is to compute the exergy loss
profile and to analyse the distribution of the losses across the column stages. The present
work aims at applying the stage-by-stage exergy analysis to the distillation of non-ideal
mixtures, e.g. methanol/water. For these systems the use of thermodynamic excess
properties is required: Gibbs free energy for phase equilibrium and enthalpy of solution
for energy balance. Initial studies showed that the enthalpy of solution has a small effect
on the overall energy balance of the distillation column, but a significant impact on the
exergy loss profiles. Some profiles even showed a violation of the second law of
thermodynamics, with entropy being destroyed on some stages, clearly indicating that a
wrong approach to exergy calculation was being used.A model for exergy calculations of
non-ideal solutions is presented. The exergy values so computed are then checked by a
consistency test, using the reversible column profile. Finally, the exergy procedures are
used to study a typical methanol/water distillation columns, where the exergy profiles are
used to identify scope for intermediate heat exchange
Finding Out The Neurological Consequences Of Covid-19
t- Introduction: Since the first official case of COVID-19 in China in December 2019, researchers have been trying to uncover the mechanism of action of the severe acute respiratory syndrome Coronavirus 2 (Sars-CoV-2), which attacks several organs in addition to the lungs and causes circulatory changes that can lead to death not only from lung failure but also due to commitment of other organs. Objective: The aim of this study is to find out the neurological consequences of COVID-19. Material and methods: A systematic review of the literature was concretised by mobilizing the descriptors:
"Sars-Cov-2", "coronavirus infections" and "Neurological Consequences". Databases were selected and seven articles were included for analysis. Results and discussion: Although the effects of Sars-CoV-2 on the lung are exemplary and frightening, the long-term effects on the nervous system may be greater and even more overwhelming, as the regeneration of nerve tissue is difficult and can lead to general disability, as the nervous system coordinates the functions of the entire body. All studies show the presence of any kind of injury (mild or severe) to Central Nervous System, but some of them highlight the need for further studies to have great certainty. Conclusion: It can be said that the studies all agree on the possibility of existing neurological sequelae and a majority agree on the need for other studies.info:eu-repo/semantics/publishedVersio
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