Rank Regressions, Wage Distributions and the Gender Gap.

In this paper, we model the interactions between the distribution of male and female wages under the assumption that any change in the wage distribution of women must be offset by an opposite change in the wage distribution of men.

La eficiencia administrativa frente a los derechos laborales adquiridos, en la escisión del instituto de seguros sociales

Antes de la expedición de la Ley 100 de 1993, el ISS prestaba los servicios de salud a los asalariados del sector privado en un monopolio que no le exigía ningún esfuerzo. El déficit acumulado por la falta de los aportes de la nación previstos en la Ley 90 de 1946 y los cambios en su naturaleza jurídica no le permitieron asumir el reto de la libre competencia de los actores dentro del sistema, por lo que su gestión fue cuestionada por los organismos de control y por varios fallos judiciales adversos que profundizaron su crisis financiera, sumado a los altos costos laborales por los beneficios de la convención colectiva de trabajo, cuyos mayores beneficiarios eran los servidores de las clínicas y CAA, llevando a la formulación del Documento Conpes 3219 del 31 de 2003 denominado “PLAN DE MODERNIZACIÓN DEL INSTITUTO DE SEGUROS SOCIALES - SALUD”, cuyo resultado fue la expedición del Decreto 1750 de junio 26 de 2003, que ordenó la escisión de la vicepresidencia prestadora de servicios de salud, clínicas y centros de atención ambulatoria (CAA) y la creación de siete empresas sociales del Estado. La escisión produjo cambios significativos en materia laboral para los servidores que hasta esa fecha laboraban en calidad de trabajadores oficiales del Instituto ya que fueron incorporados automáticamente a las plantas de personal de las nuevas empresas en calidad de empleados públicos, con excepción de los que desempeñaban cargos directivos o funciones de mantenimiento de la planta física hospitalaria y servicios generales, considerados trabajadores oficiales; cuyo régimen salarial y prestacional es el estipulado para los empleados públicos de la rama ejecutiva del orden nacional (artículos 16 y 18), lo que condujo al aparente desconocimiento de los derechos adquiridos por estos servidores en materia de negociación colectiva. El Decreto 1750 de 2003 fue demandado por vulnerar el ordenamiento superior y, en sentencias de control de constitucionalidad y desde la teoría de los derechos adquiridos, la Corte Constitucional estimó que el artículo 18 era restrictivo por hacer referencia solo a los derechos adquiridos en materia prestacional sin contemplar los relativos a materia salarial y los contenidos en convenciones colectivas de trabajo. Al existir entre el Instituto de Seguros Sociales y sus trabajadores una convención colectiva de trabajo vigente, de conformidad con las Sentencias C-314 de 2004 y C 349 de 2004, la Corte Constitucional indicó que dicha convención debía aplicarse a los servidores de las nuevas entidades por el tiempo de su vigencia.

Strategic use of private standards to enhance international competitiveness: Vegetable exports from Kenya and elsewhere

The paper examines how European retailers are using private standards for food safety and,quality as risk management and competitive tools and the strategic responses of leading Kenyan and other developing country supplier/exporters to such standards. Despite measures to harmonize a 'single market', the European fresh produce market is very diverse in terms of consumer preferences, structural dynamics and attention to and enforcement of food safety and other standards. Leading Kenyan fresh produce suppliers have re-positioned themselves at the high end, including 'high care', segments of the market - precisely those that are most demanding in terms of quality assurance and food safety systems. An array of factors have influenced this strategic positioning, including relatively high international freight costs, the emergence of more effective competition in mainstream product lines, relatively low labor costs for produce preparation, and strong market relationships with selected retail chains. To succeed in this demanding market segment, the industry has had to invest substantially in improved production and procurement systems, upgraded pack house facilities, and quality assurance/food safety management systems. (C) 2005 Elsevier Ltd. All rights reserved.

Task assignment optimization in SAP Extended WarehouseManagement

Nowadays in the world of mass consumption there is big demand for distributioncenters of bigger size. Managing such a center is a very complex and difficult taskregarding to the different processes and factors in a usual warehouse when we want tominimize the labor costs. Most of the workers’ working time is spent with travelingbetween source and destination points which cause deadheading. Even if a worker knowsthe structure of a warehouse well and because of that he or she can find the shortest pathbetween two points, it is still not guaranteed that there won’t be long traveling timebetween the locations of two consecutive tasks. We need optimal assignments betweentasks and workers.In the scientific literature Generalized Assignment Problem (GAP) is a wellknownproblem which deals with the assignment of m workers to n tasks consideringseveral constraints. The primary purpose of my thesis project was to choose a heuristics(genetic algorithm, tabu search or ant colony optimization) to be implemented into SAPExtended Warehouse Management (SAP EWM) by with task assignment will be moreeffective between tasks and resources.After system analysis I had to realize that due different constraints and businessdemands only 1:1 assingments are allowed in SAP EWM. Because of that I had to use adifferent and simpler approach – instead of the introduced heuristics – which could gainbetter assignments during the test phase in several cases. In the thesis I described indetails what ware the most important questions and problems which emerged during theplanning of my optimized assignment method.

Purchasing power parity: the choice of price index

Looking closely at the PPP argument, it states that the currencies purchasing power should not change when comparing the same basket goods across countries, and these goods should all be tradable. Hence, if PPP is valid at all, it should be captured by the relative price indices that best Öts these two features. We ran a horse race among six di§erent price indices available from the IMF database to see which one would yield higher PPP evidence, and, therefore, better Öt the two features. We used RER proxies measured as the ratio of export unit values, wholesale prices, value added deáators, unit labor costs, normalized unit labor costs and consumer prices, for a sample of 16 industrial countries, with quarterly data from 1975 to 2002. PPP was tested using both the ADF and the DFGLS unit root test of the RER series. The RER measured as WPI ratios was the one for which PPP evidence was found for the larger number of countries: six out of sixteen when we use DF-GLS test with demeaned series. The worst measure of all was the RER based on the ratio of foreign CPIs and domestic WPI. No evidence of PPP at all was found for this measure.

Desempenho de bovinos de corte mantidos em pastagem de capim-marandu submetidos a diferentes estratégias de suplementação no período das águas e da seca

Este trabalho foi realizado com o objetivo de avaliar o ganho de peso de bovinos mantidos em pastagens de Brachiaria brizantha cv. Marandu submetidos a três estratégias de suplementação no período das águas e da seca de 2003 e águas de 2004. Os tratamentos consistiram da suplementação diária (SD), em dias alternados (DA) e de segunda à sexta-feira (SF). Foram utilizados 24 bovinos mestiços com peso inicial de 230 kg. Os animais foram pesados individualmente sem jejum, em intervalos de 28 dias. O delineamento adotado foi o inteiramente casualizado, com três tratamentos e oito repetições. Não houve diferença no ganho de peso dos animais, sendo obtidos valores médios de 0,76; 0,71 e 0,74 kg/dia no período das águas de 2003, de 0,57; 0,51 e 0,54 kg/dia na seca do mesmo ano e de 0,61; 0,62 e 0,57 kg/dia no período das águas de 2004 nos tratamentos SD, da e SF, respectivamente. A redução na freqüência de suplementação pode representar uma opção para o produtor visando à redução dos custos do fornecimento da alimentação, pois permite maior racionalização da mão-de-obra na propriedade e não afeta o desempenho animal.

Comportamento do camarão de água doce macrobrachium rosenbergii (De Man, 1879) em cultivos misto e monossexo

Understanding the behavioral activities of freshwater shrimp in captivity is of paramount importance for the appropriate management of the species. In Brazil, the shrimp Macrobrachium rosenbergii is currently the most widely used species in the freshwater shrimp culture due to its high potential for cultivation and good market acceptance. Thus, the present study aimed to describe and characterize the behavioral activities of M. rosenbergii in monosex and in mixed (male and female) (manuscript 1, 2 and 3) populations and the growth performance of this species in restrictive feeding conditions and in different feeding management (manuscript 4 and 5, respectively) . Juvenile and adult shrimps were collected from ponds of the Aquaculture Station - Unidade Especializada em Ciências Agrárias - Universidade Federal do Rio Grande do Norte (UFRN), Macaíba/RN and then transferred to the Laboratório de Estudos do Comportamento do Camarão LECC (Laboratory for Shrimp Behavioral Studies) of the Universidade Federal do Rio Grande do Norte (UFRN). For each treatment , eight aquaria of 250 L (50 cm x 50 cm x 100 cm) were used in a closed recirculating water system with artificial lighting, constant aeration , continuous filtration through a biochemical and biological filter (canister filter), and fine sand as substrate . The water quality was monitored daily. The lab consisted of two rooms with artificial lighting system , controlled by a timer with dark / light cycle of 12:12 h . In manuscript 1, the behavioral categories of the species were presented through an ethogram, which described 31 behaviors, subdivided into general and agonistic behaviors. Manuscript 2 compared the behavioral profile of shrimps in male and in female monosex and mixed populations over 24 hours in laboratory. In three types (mixed, male monosex and female monosex) of populations during the light and dark phases of the 24 hour cycle, the shrimps showed higher occurrence of cleaning behavior. Manuscript 3 examined the influence of the color of the shelter on the frequency of its use and behavioral activities of shrimp in mixed, in male monosex and in female monosex populations over 24 hours. We observed that the shrimp M. rosenbergii burrow more frequently during the light phase in male monosex and mixed populations; they also tend to choose the black shelters. Female monosex populations tend to use red and orange shelters. In manuscript 4, we evaluated in laboratory the behavioral activities and growth performance of juvenile shrimps under food restriction. We observed that a mild food restriction may be used since there is no loss concerning the growth of the animals; feeding management on alternate days , compared to daily management can be financially productive both reducing labor costs and reducing the amount of feed used . Manuscript 5 evaluated the behavior of shrimps in monosex and in mixed populations, as well as the latency of reach the food according to feed offer (tray or food dispersal) . Our results indicate that animals adjust to both types of feed offer food dispersal as much as tray, but they spend more time to reach the feed when it is offered in trays (feeders). Comparing culture types (mixed, male monosex and female monosex), the latency to reach the food was lower for female monosex population. The data obtained in this study demonstrate the importance of identifying different pressures and environmental stimuli on the behavioral responses of this species. This knowledge would support management improvement to optimize the levels of animals‟ welfare, resulting in a better zootecnical performance

Optimal moment to change pressure regulator and sprayer kit on center pivot irrigation machines: a theoretical proposal

A theoretical model was developed in order to determine the optimal moment for substituting the sprayer and pressure regulator kit on a center pivot irrigation machine. The model is based on the hypothesis that pressure regulator and sprayer deterioration decrease irrigation uniformity. To compensate the deficit that happens at under irrigated areas, an increase on irrigation depth is required. The model considers: additional water consumption and energy costs, maintenance and labor costs, as well as yield losses associated with under or over irrigated areas. The sum of all these components is compared to buying and installing a new spray kit cost, allowing the farmer to decide the best moment to renovate the sprayer and pressure regulator kits on a center pivot irrigation machine based on economic criteria.

Custos e viabilidade econômica da produção de casulos do bicho-da-seda

Sericiculture is characterized by the possibility of income generation in areas smaller than 10.0 ha and by the rationalization of family labor. Even considering this favorable scenario for the development of this activity, there is still a gap in the management of its economic factors in most of the rural properties within this chain, contributing negatively to their expansion. This study aimed at assessing the production cost and economic viability for producing silkworm cocoons, by using a case study conducted in a property located in Quatá, São Paulo State, Brazil. The main results for a production of 1,904 kg-1 of silkworm cocoons, with labor costs reaching 51.5% of the Effective Operating Cost and 35.5% of the Total Operating Cost, were a profitability index higher than 50% and an Internal Rate of Return of 9.68%, for the second production year, providing a good profitability rate for this agricultural segment, when we consider that the improved profitability of the producer is proportional to the best production indicators, particularly due to the fast return that this activity provides.

Análise técnica e econômica da resinagem de Pinus elliottii Engelm. var. elliottii na região de Manduri, SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reducing supplementation frequency for Nellore beef steers grazing tropical pastures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise técnica e econômica das etapas de produção de mudas de eucalipto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of supplementation frequency on the ruminal fermentation and enteric methane production of beef cattle grazing in tropical pastures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

HAWAIIAN SUGAR CANE RAT CONTROL METHODS AND PROBLEMS

The problem of rats in our Hawaiian sugar cane fields has been with us for a long time. Early records tell of heavy damage at various times on all the islands where sugar cane is grown. Many methods were tried to control these rats. Trapping was once used as a control measure, a bounty was used for a time, gangs of dogs were trained to catch the rats as the cane was harvested. Many kinds of baits and poisons were used. All of these methods were of some value as long as labor was cheap. Our present day problem started when the labor costs started up and the sugar industry shifted to long cropping. Until World War II cane was an annual crop. After the war it was shifted to a two year crop, three years in some places. Depending on variety, location, and soil we raise 90 to 130 tons of sugar cane per acre, which produces 7 to 15 tons of sugar per acre for a two year crop. This sugar brings about $135 dollars per ton. This tonnage of cane is a thick tangle of vegetation. The cane grows erect for almost a year, as it continues to grow it bends over at the base. This allows the stalk to rest on the ground or on other stalks of cane as it continues to grow. These stalks form a tangled mat of stalks and dead leaves that may be two feet thick at the time of harvest. At the same time the leafy growing portion of the stalk will be sticking up out of the mat of cane ten feet in the air. Some of these individual stalks may be 30 feet long and still growing at the time of harvest. All this makes it very hard to get through a cane field as it is one long, prolonged stumble over and through the cane. It is in this mat of cane that our three species of rats live. Two species are familiar to most people in the pest control field. Rattus norvegicus and Rattus rattus. In the latter species we include both the black rat and the alexandrine rats, their habits seem to be the same in Hawaii. Our third rat is the Polynesian rat, Rattus exlans, locally called the Hawaiian rat. This is a small rat, the average length head to tip of tail is nine inches and the average body weight is 65 grams. It has dark brownish fur like the alexandrine rats, and a grey belly. It is found in Indonesia, on most of the islands of Oceania and in New Zealand. All three rats live in our cane fields and the brushy and forested portions of our islands. The norway and alexandrine rats are found in and around the villages and farms, the Polynesian rat is only found in the fields and waste areas. The actual amount of damage done by rats is small, but destruction they cause is large. The rats gnaw through the rind of the cane stalk and eat the soft juicy and sweet tissues inside. They will hollow out one to several nodes per stalk attacked. The effect to the cane stalk is like ringing a tree. After this attack the stalk above the chewed portion usually dies, and sometimes the lower portion too. If the rat does not eat through the stalk the cane stalk could go on living and producing sugar at a reduced rate. Generally an injured stalk does not last long. Disease and souring organisms get in the injury and kill the stalk. And if this isn't enough, some insects are attracted to the injured stalk and will sometimes bore in and kill it. An injured stalk of cane doesn't have much of a chance. A rat may only gnaw out six inches of a 30 foot stalk and the whole stalk will die. If the rat only destroyed what he ate we could ignore them but they cause the death of too much cane. This dead, dying, and souring cane cause several direct and indirect tosses. First we lose the sugar that the cane would have produced. We harvest all of our cane mechanically so we haul the dead and souring cane to the mill where we have to grind it with our good cane and the bad cane reduces the purity of the sugar juices we squeeze from the cane. Rats reduce our income and run up our overhead.