Subset sum problems with digraph constraints

We introduce and study optimization problems which are related to the well-known Subset Sum problem. In each new problem, a node-weighted digraph is given and one has to select a subset of vertices whose total weight does not exceed a given budget. Some additional constraints called digraph constraints and maximality need to be satisfied. The digraph constraint imposes that a node must belong to the solution if at least one of its predecessors is in the solution. An alternative of this constraint says that a node must belong to the solution if all its predecessors are in the solution. The maximality constraint ensures that no superset of a feasible solution is also feasible. The combination of these constraints provides four problems. We study their complexity and present some approximation results according to the type of input digraph, such as directed acyclic graphs and oriented trees.     

Thermal comfort and personal protective equipment (PPE)

Personal Protective Equipment (PPE) is considered the last preferred solution to an Occupational Safety Health (OSH) system. Brazilian OSH legislation assumes and requires PPE usage to neutralize the possibility of pesticide contamination. This study examines the inadequacy of the PPE used in a tomato crop, particularly from the standpoint of thermal comfort. This study made observations regarding heart rate and body temperature in a controlled environment using a treadmill (with and without PPE) of 12 volunteers; and during the process of rural labor (at rest and in normal work routine) of 2 actual rural workers. Comparing the results of the treadmill test (with and without PPE) which tried to reproduce the same level of effort and environmental conditions of the actual rural work, this study demonstrated that PPE makes thermoregulation harder and tympanic temperature reaches higher values with the same level of effort. Moreover, body temperature increases quickly: with PPE it took 15 minutes to raise 1°C in body temperature, compared to 40 minutes without PPE. The results of this study indicated that the use inadequate PPE might pose thermoregulation risk to rural workers.     

Ergonomic factors and production target evaluation in eucalyptus timber harvesting operations in mountainous terrains

There are several forest operations involved in Eucalyptus timber harvesting. This study was carried out during brush-cutting; tree felling, bucking, delimbing, piling and manual extraction operations, with the following objectives: a) analyzing, ergonomically, two systems of brush-cutting: one manual and the other semi-mechanized, using two different machines; b) ergonomically evaluating three different brands of pruner machines used in delimbing felled trees. c) determining the feasible target of productivity as a function of ergonomic factors relevant to establish the time of resting pauses for workers in manual and semi-mechanized timber harvesting systems in mountainous terrain. Brush-cutting, either manual or semimechanized, is an activity carried out prior to timber harvesting. It is usually a hard work, with low productivity when compared with mechanized systems. Pruner machines have been used by forest companies, due to the great possibilities to improve productivity, quality and the health of workers. Ergonomics is a discipline that promotes the adequacy of work to the physical and mental characteristics of human beings, seeking to design production systems and products considering relevant aspects, including social, organizational and environmental factors. Companies should consider the ergonomic factor in the determination of daily worker production targets.     

Nurses' working tasks and MSDs back symptoms: results from a national survey

Healthcare workers, namely registered nurses (RN), are frequently exposed to work-related musculoskeletal disorders (WRMSDs) risk factors. Identifying the symptoms of these disorders is one of the first epidemiological steps to managing them. This study aims to identify WRMSDs prevalence symptoms in Portuguese RN. During 8 months (2010-2011) the National Public Health School and the Portuguese Registered Nurses Board made a call to all RN to answer an online WRMSDs questionnaire. Respondents (n=2140) are mostly females (77.4%) and work mainly in hospitals (n=1396) and in primary healthcare centers (n=421). Results show high symptoms prevalence (last 12 months) in the lower back (60.6%), the upper back (44.5%), and the neck (48.6%). Nurses' activity, especially patient hygiene in bed, is a strong contributor (p>0.05) to pain in the upper back (OR=1.39 [1.09-1.80]) and lower back (OR=1.4 [1.08-1.84]). Patient holdup without mechanical support has the highest relationship (p>0.05) between work tasks and symptoms in the last 12 months in the upper back (OR=1.50 [1.19-1.90]). Prevalence rates of WRMSDs symptoms in Portuguese nurses are no different from other studies with Swedish, Italian and Greek nurses. Maybe changes in healthcare systems didn't change the way care is delivered and we must rethink how to prevent nurses WRMSDs.     

Irregular working times and metabolic disorders among truck drivers: a review

A number of studies to better understand the complex physiological mechanism involved in regulating body weight have been conducted. More specifically, the hormones related to appetite, leptin and ghrelin, and their association to obesity have been a focus of investigation. Circadian patterns of these hormones are a new target of research. The behaviour of these hormones in individuals subject to atypical working times such as shiftwork remains unclear. Shiftwork is characterized by changes in biological rhythms and cumulative circadian phase changes, being associated with high rates of obesity and metabolic syndrome. Truck drivers, who work irregular shifts, frequently present a high prevalence of obesity, which might be associated with work-related factors and/or lifestyle. In this context, the aim of this paper was to discuss the relationship of body mass index, appetite-related hormones and sleep characteristics in truck drivers who work irregular shifts compared with day workers.     

<Emphasis Type="BoldItalic">MAD-STEC</Emphasis>: a method for multiple automatic detection of space-time emerging clusters

Crime or disease surveillance commonly rely in space-time clustering methods to identify emerging patterns. The goal is to detect spatial-temporal clusters as soon as possible after its occurrence and to control the rate of false alarms. With this in mind, a spatio-temporal multiple cluster detection method was developed as an extension of a previous proposal based on a spatial version of the Shiryaev–Roberts statistic. Besides the capability of multiple cluster detection, the method have less input parameter than the previous proposal making its use more intuitive to practitioners. To evaluate the new methodology a simulation study is performed in several scenarios and enlighten many advantages of the proposed method. Finally, we present a case study to a crime data-set in Belo Horizonte, Brazil.     

Longitudinal Factor Analysis of Public Expenditure Composition and Human Development in Brazil After the 1988 Constitution

The way public policies are managed in Brazil has changed since the 1988 Federal Constitution. This study aimed to identify how changes in the structure of public expenditure composition at Brazilian federal states influenced local human development in these states. The states’ public expenditures were categorized according to their nature as spending indices whereas human development was measured through a human development index (HD). To verify the relationships between these variables, an accounting-social theoretical model was created and estimated through latent growth modeling (LGM). The LGM measurement period comprised five administration cycles of the Brazilian states (1988–2011). Variables were measured on data of the second year of state government term; their mean initial values and growth rates were recorded. Results show that, influenced by policies of centralized regulation promoted by the federal government, only the social spending growth rates had statistically significant effect on the human development growth rate, although not considered of great magnitude. Among mean initial values, the most significant was that of minimum spending (SIm), which denotes the direct impact of the Fiscal Accountability Law [Lei de Responsabilidade Fiscal, in Portuguese] on human development improvements. The mean initial value of economic spending also showed a positive and significant effect on HD growth rate.     

When ERM Met Alma: The Intricacies of Content Management in a Shared Consortia Landscape

ABSTRACT

In 2013, after nearly two decades of operating in a distributed legacy Integrated Library System (ILS) environment on local servers, the Orbis Cascade Alliance, a consortium of public and private academic libraries in Washington, Oregon, and Idaho, began a two-year-long process to migrate its 37 members to a shared implementation of Ex Libris's cloud-based Alma library management system (LMS) and Primo discovery interface. Although much has been written on electronic resource management (ERM) functionality at an institution level, little has been written on serials and ERM functionality and workflows within a shared consortial environment. This article discusses the challenges and opportunities of implementing a consortial-based LMS, with particular emphasis on serials and ERM functionality. Key migration issues related to serials control, acquisitions, licensing, administration, cataloging, statistics, and interoperability are examined at the institutional and large-scale networked levels. Benefits and limitations of using a shared consortial cloud-based LMS are explored, and the overall capabilities of the Alma LMS for electronic resource management are reviewed.     

Asymptotic inference in poverty indices: an empirical processes approach

We derive an empirical poverty index containing most of those proposed in the literature. Then, we study its asymptotic behavior by using empirical processes theory. From the results obtained, we derive a Wald-type test for comparing a vector of theoretical poverty indices to a vector of reference indices. We study the test statistic under the null hypothesis of equality, fixed alternatives, and a sequence of local alternatives. A simulation experiment conducted shows that our test performs well for exponential and Pareto data.