Situation of unpaid work and gender in the Caribbean: The measurement of unpaid work through time-use studies

Includes bibliography.

The employment situation in Latin America and the Caribbean: Advances and challenges in measuring decent work

At 6.4%, the unemployment rate for the Latin American and Caribbean region overall was the lowest for the past few decades, down from 6.7% in 2011. This is significant, in view of the difficult employment situation prevailing in other world regions. Labour market indicators improved despite modest growth of just 3.0% in the region’s economy. Even with sharply rising labour market participation, the number of urban unemployed fell by around 400,000, on the back of relatively strong job creation. Nevertheless, around 15 million are still jobless in the region. Other highlights of 2012 labour market performance were that the gender gaps in labour market participation, unemployment and employment narrowed, albeit slightly; formal employment increased; the hourly underemployment rate declined; and average wages rose. This rendering was obviously not homogenous across the region. Labour market indicators worsened again in the Caribbean countries, for example, reflecting the sluggish performance of their economies. The sustainability of recent labour market progress is also a cause for concern. Most of the new jobs in the region were created as part of a self-perpetuating cycle in which new jobs and higher real wages (and greater access to credit) have boosted household purchasing power and so pushed up domestic demand. Much of this demand is for non-tradable goods and services (and imports), which has stimulated expansion of the tertiary sector and hence its demand for labour, and many of the new jobs have therefore arisen in these sectors of the economy. This dynamic certainly has positive implications in terms of labour and distribution, but the concern is whether it is sustainable in a context of still relatively low investment (even after some recent gains) which is, moreover, not structured in a manner conducive to diversifying production. Doubt hangs over the future growth of production capacity in the region, given the enormous challenges facing the region in terms of innovation, education quality, infrastructure and productivity. As vigorous job creation has driven progress in reducing unemployment, attention has turned once again to the characteristics of that employment. Awareness exists in the region that economic growth is essential, but not in itself sufficient to generate more and better jobs. For some time, ILO has been drawing attention to the fact that it is not enough to create any sort of employment. The concept of decent work, as proposed by ILO, emphasized the need for quality jobs which enshrine respect for fundamental rights at work. The United Nations General Assembly endorsed this notion and incorporated it into the targets set in the framework of the Millennium Development Goals. This eighth issue of the ECLAC/ILO publication “The employment situation in Latin America and the Caribbean” examines how the concept of decent work has evolved in the region, progress in measuring it and the challenges involved in building a system of decent work indicators, 14 years after the concept was first proposed. Although the concept of decent work has been accompanied since the outset by the challenge of measurement, its first objective was to generate a discussion on the best achievable labour practices in each country. Accordingly, rather than defining a universal threshold of what could be considered decent work —regarding which developed countries might have almost reached the target before starting, while poor countries could be left hopelessly behind— ILO called upon the countries to define their own criteria and measurements for promoting decent work policies. As a result, there is no shared set of variables for measuring decent work applicable to all countries. The suggestion is, instead, that countries move forward with measuring decent work on the basis of their own priorities, using the information they have available now and in the future. However, this strategy of progressing according to the data available in each country tends to complicate statistical comparison between them. So, once the countries have developed their respective systems of decent work indicators, it will be also be important to work towards harmonizing them. ECLAC and ILO are available to provide technical support to this end. With respect to 2013, there is cautious optimism regarding the performance of the region’s labour markets. If projections of a slight uptick —to 3.5%— in the region’s economic growth in 2013 are borne out, labour indicators should continue to gradually improve. This will bring new increases in real wages and a slight drop of up to 0.2 percentage points in the region’s unemployment rate, reflecting a fresh rise in the regional employment rate and slower growth in labour market participation.

Diastolic blood pressure associated with accumulated work time among drivers and collectors

The relationship between diastolic blood pressure and the variables total cumulative working time and age was examined by regression analysis. The study was carried out among 839 bus drivers and conductors, users of an occupational health center in Campinas, S. Paulo State, Brazil. The main results were a positive association between diastolic blood pressure and cumulative working time, as well as an interaction between this variable and the bus worker's age.

On Fermat's principle for causal curves in time oriented Finsler spacetimes

In this work, a version of Fermat's principle for causal curves with the same energy in time orientable Finsler spacetimes is proved. We calculate the second variation of the time arrival functional along a geodesic in terms of the index form associated with the Finsler spacetime Lagrangian. Then the character of the critical points of the time arrival functional is investigated and a Morse index theorem in the context of Finsler spacetime is presented. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4765066]

Residence Time Distribution Models Derived from Non-Ideal Laminar Velocity Profiles in Tubes

The theoretical E-curve for the laminar flow of non-Newtonian fluids in circular tubes may not be accurate for real tubular systems with diffusion, mechanical vibration, wall roughness, pipe fittings, curves, coils, or corrugated walls. Deviations from the idealized laminar flow reactor (LFR) cannot be well represented using the axial dispersion or the tanks-in-series models of residence time distribution (RTD). In this work, four RTD models derived from non-ideal velocity profiles in segregated tube flow are proposed. They were used to represent the RTD of three tubular systems working with Newtonian and pseudoplastic fluids. Other RTD models were considered for comparison. The proposed models provided good adjustments, and it was possible to determine the active volumes. It is expected that these models can be useful for the analysis of LFR or for the evaluation of continuous thermal processing of viscous foods.

Fuzzy Connectedness Image Segmentation in Graph Cut Formulation: A Linear-Time Algorithm and a Comparative Analysis

A deep theoretical analysis of the graph cut image segmentation framework presented in this paper simultaneously translates into important contributions in several directions. The most important practical contribution of this work is a full theoretical description, and implementation, of a novel powerful segmentation algorithm, GC(max). The output of GC(max) coincides with a version of a segmentation algorithm known as Iterative Relative Fuzzy Connectedness, IRFC. However, GC(max) is considerably faster than the classic IRFC algorithm, which we prove theoretically and show experimentally. Specifically, we prove that, in the worst case scenario, the GC(max) algorithm runs in linear time with respect to the variable M=|C|+|Z|, where |C| is the image scene size and |Z| is the size of the allowable range, Z, of the associated weight/affinity function. For most implementations, Z is identical to the set of allowable image intensity values, and its size can be treated as small with respect to |C|, meaning that O(M)=O(|C|). In such a situation, GC(max) runs in linear time with respect to the image size |C|. We show that the output of GC(max) constitutes a solution of a graph cut energy minimization problem, in which the energy is defined as the a"" (a) norm ayenF (P) ayen(a) of the map F (P) that associates, with every element e from the boundary of an object P, its weight w(e). This formulation brings IRFC algorithms to the realm of the graph cut energy minimizers, with energy functions ayenF (P) ayen (q) for qa[1,a]. Of these, the best known minimization problem is for the energy ayenF (P) ayen(1), which is solved by the classic min-cut/max-flow algorithm, referred to often as the Graph Cut algorithm. We notice that a minimization problem for ayenF (P) ayen (q) , qa[1,a), is identical to that for ayenF (P) ayen(1), when the original weight function w is replaced by w (q) . Thus, any algorithm GC(sum) solving the ayenF (P) ayen(1) minimization problem, solves also one for ayenF (P) ayen (q) with qa[1,a), so just two algorithms, GC(sum) and GC(max), are enough to solve all ayenF (P) ayen (q) -minimization problems. We also show that, for any fixed weight assignment, the solutions of the ayenF (P) ayen (q) -minimization problems converge to a solution of the ayenF (P) ayen(a)-minimization problem (ayenF (P) ayen(a)=lim (q -> a)ayenF (P) ayen (q) is not enough to deduce that). An experimental comparison of the performance of GC(max) and GC(sum) algorithms is included. This concentrates on comparing the actual (as opposed to provable worst scenario) algorithms' running time, as well as the influence of the choice of the seeds on the output.

Application of the log-conformation tensor to three-dimensional time-dependent free surface flows

The numerical simulation of flows of highly elastic fluids has been the subject of intense research over the past decades with important industrial applications. Therefore, many efforts have been made to improve the convergence capabilities of the numerical methods employed to simulate viscoelastic fluid flows. An important contribution for the solution of the High-Weissenberg Number Problem has been presented by Fattal and Kupferman [J. Non-Newton. Fluid. Mech. 123 (2004) 281-285] who developed the matrix-logarithm of the conformation tensor technique, henceforth called log-conformation tensor. Its advantage is a better approximation of the large growth of the stress tensor that occur in some regions of the flow and it is doubly beneficial in that it ensures physically correct stress fields, allowing converged computations at high Weissenberg number flows. In this work we investigate the application of the log-conformation tensor to three-dimensional unsteady free surface flows. The log-conformation tensor formulation was applied to solve the Upper-Convected Maxwell (UCM) constitutive equation while the momentum equation was solved using a finite difference Marker-and-Cell type method. The resulting developed code is validated by comparing the log-conformation results with the analytic solution for fully developed pipe flows. To illustrate the stability of the log-conformation tensor approach in solving three-dimensional free surface flows, results from the simulation of the extrudate swell and jet buckling phenomena of UCM fluids at high Weissenberg numbers are presented. (C) 2012 Elsevier B.V. All rights reserved.

Closed-loop stable model predictive control of integrating systems with dead time

Model predictive control (MPC) applications in the process industry usually deal with process systems that show time delays (dead times) between the system inputs and outputs. Also, in many industrial applications of MPC, integrating outputs resulting from liquid level control or recycle streams need to be considered as controlled outputs. Conventional MPC packages can be applied to time-delay systems but stability of the closed loop system will depend on the tuning parameters of the controller and cannot be guaranteed even in the nominal case. In this work, a state space model based on the analytical step response model is extended to the case of integrating time systems with time delays. This model is applied to the development of two versions of a nominally stable MPC, which is designed to the practical scenario in which one has targets for some of the inputs and/or outputs that may be unreachable and zone control (or interval tracking) for the remaining outputs. The controller is tested through simulation of a multivariable industrial reactor system. (C) 2012 Elsevier Ltd. All rights reserved.

Nonlinear estimation of neural processing time from BOLD signal with application to decision-making

The extraction of information about neural activity timing from BOLD signal is a challenging task as the shape of the BOLD curve does not directly reflect the temporal characteristics of electrical activity of neurons. In this work, we introduce the concept of neural processing time (NPT) as a parameter of the biophysical model of the hemodynamic response function (HRF). Through this new concept we aim to infer more accurately the duration of neuronal response from the highly nonlinear BOLD effect. The face validity and applicability of the concept of NPT are evaluated through simulations and analysis of experimental time series. The results of both simulation and application were compared with summary measures of HRF shape. The experiment that was analyzed consisted of a decision-making paradigm with simultaneous emotional distracters. We hypothesize that the NPT in primary sensory areas, like the fusiform gyrus, is approximately the stimulus presentation duration. On the other hand, in areas related to processing of an emotional distracter, the NPT should depend on the experimental condition. As predicted, the NPT in fusiform gyrus is close to the stimulus duration and the NPT in dorsal anterior cingulate gyrus depends on the presence of an emotional distracter. Interestingly, the NPT in right but not left dorsal lateral prefrontal cortex depends on the stimulus emotional content. The summary measures of HRF obtained by a standard approach did not detect the variations observed in the NPT. Hum Brain Mapp, 2012. (C) 2010 Wiley Periodicals, Inc.

Need for recovery from work and sleep-related complaints among nursing professionals

The concept of need for recovery from work (NFR) was deduced from the effort recuperation model. In this model work produces costs in terms of effort during the working day. When there is enough time and possibilities to recuperate, a worker will arrive at the next working day with no residual symptoms of previous effort. NFR evaluates work characteristics such as psychosocial demands, professional work hours or schedules. However, sleep may be an important part of the recovery process. The aim of the study was to test the association between sleep-related complaints and NFR. A cross-sectional study was carried out at three hospitals. All females nursing professionals engaged in assistance to patients were invited to participate (N=1,307). Participants answered a questionnaire that included four sleep-related complaints (insomnia, unsatisfactory sleep, sleepiness during work hours and insufficient sleep), work characteristics and NRF scale. Binomial logistic regression analysis showed that all sleep-related complaints are associated with a high need for recovery from work. Those who reported insufficient sleep showed a greater chance of high need for recovery; OR=2.730 (CI 95% 2.074-3.593). These results corroborate the hypothesis that sleep is an important aspect of the recovery process and, therefore, should be thoroughly investigated.

Effects of Working Full-Time and Studying in the Evening Hours Among Young Apprentices and Trainees

Objective: This research aims to assess apprentices' and trainees' work conditions, psychosocial factors at work, as well as health symptoms after joining the labor force. Background: Despite the fact that there are over 3.5 million young working students in Brazil, this increasing rate brings with it difficult working conditions such as work pressure, heavy workloads, and lack of safety training. Method: This study was carried out in a nongovernmental organization (NGO) with 40 young members of a first job program in the city of Sao Paulo, Brazil. They filled out a comprehensive questionnaire focused on sociodemographic variables, working conditions, and health symptoms. Individual and collective semi-structured interviews were conducted. Empirical data analysis was performed using analysis of content. Results: The majority of participants mentioned difficulties in dealing with the pressure and their share of responsibilities at work. Body pains, headaches, sleep deprivation during the workweek, and frequent colds were mentioned. Lack of appropriate task and safety training contributed to the occurrence of work injuries. Conclusion: Having a full-time job during the day coupled with evening high school attendance may jeopardize these people's health and future. Application: This study can make a contribution to the revision and implementation of work training programs for adolescents. It can also help in the creation of more sensible policies regarding youth employment.

Solar-Terrestrial Signal Record in Tree Ring Width Time Series from Brazil

This work investigates the behavior of the sunspot number and Southern Oscillation Index (SOI) signal recorded in the tree ring time series for three different locations in Brazil: Humaita in Amaznia State, Porto Ferreira in So Paulo State, and Passo Fundo in Rio Grande do Sul State, using wavelet and cross-wavelet analysis techniques. The wavelet spectra of tree ring time series showed signs of 11 and 22 years, possibly related to the solar activity, and periods of 2-8 years, possibly related to El Nio events. The cross-wavelet spectra for all tree ring time series from Brazil present a significant response to the 11-year solar cycle in the time interval between 1921 to after 1981. These tree ring time series still have a response to the second harmonic of the solar cycle (5.5 years), but in different time intervals. The cross-wavelet maps also showed that the relationship between the SOI x tree ring time series is more intense, for oscillation in the range of 4-8 years.

Sleep length, working hours and socio-demographic variables are associated with time attending evening classes among working college students

It is the aim of the present study to assess factors associated with time spent in class among working college students. Eighty-two working students from 21 to 26 years old participated in this study. They were enrolled in an evening course of the University of Sao Paulo, Brazil. Participants answered a questionnaire on living and working conditions. During seven consecutive days, they wore an actigraph, filled out daily activity diaries (including time spent in classes) and the Karolinska Sleepiness Scale every three hours from waking until bedtime. Linear regression analyses were performed in order to assess the variables associated with time spent in classes. The results showed that gender, sleep length, excessive sleepiness, alcoholic beverage consumption (during workdays) and working hours were associated factors with time spent in class. Thus, those who spent less time in class were males, slept longer hours, reported excessive sleepiness on Saturdays, worked longer hours, and reported alcohol consumption. The combined effects of long work hours (>40 h/week) and reduced sleep length may affect lifestyles and academic performance. Future studies should aim to look at adverse health effects induced by reduced sleep duration, even among working students who spent more time attending evening classes.

Constraint-based analysis of gene interactions using restricted boolean networks and time-series data

Abstract Background A popular model for gene regulatory networks is the Boolean network model. In this paper, we propose an algorithm to perform an analysis of gene regulatory interactions using the Boolean network model and time-series data. Actually, the Boolean network is restricted in the sense that only a subset of all possible Boolean functions are considered. We explore some mathematical properties of the restricted Boolean networks in order to avoid the full search approach. The problem is modeled as a Constraint Satisfaction Problem (CSP) and CSP techniques are used to solve it. Results We applied the proposed algorithm in two data sets. First, we used an artificial dataset obtained from a model for the budding yeast cell cycle. The second data set is derived from experiments performed using HeLa cells. The results show that some interactions can be fully or, at least, partially determined under the Boolean model considered. Conclusions The algorithm proposed can be used as a first step for detection of gene/protein interactions. It is able to infer gene relationships from time-series data of gene expression, and this inference process can be aided by a priori knowledge available.