A longitudinal study of enterobiasis in three day care centers of Havana City

Pinworm infection was prospectively studied during one year in 469 children attending three day care centers. Each child was examined at six months intervals using up to three perianal swabs with adhesive tape. Those found infected were treated with mebendazole. At the beginning of the study we found a prevalence of 28% that dropped to 13% and 12% in the following study periods. The reinfection rate was twice the incidence rate in both study periods. We also found a small percentage (10%) of the children reinfected in most or all study periods. There was a high correlation between reinfection and perianal itching. Our results add further knowledge to the epidemiology of intestinal parasites in day care centers.

Cytomegalovirus infection in a day-care center in the municipality of São Paulo

The prevalence of antibodies against cytomegalovirus (CMV) and the incidence of CMV infection were tested in 98 children aged 5 to 36 months who attended the day-care center of a University hospital in São Paulo. At the beginning of the study the overall prevalence of anti-CMV IgG antibodies was 44% (43/98). Saliva and/or urine samples were obtained from 38 of the 43 children that were seropositive at the beginning of the study for isolation of the virus, and 52.6% of these children were found to excrete CMV in one of the two materials. Among the 37 children that were initially seronegative from whom it was possible to obtain a new blood sample 6 to 12 months later, 22 (59.5%) presented seroconversion. The rate of viral excretion through urine or saliva from the children that seroconverted was 50%. These results indicate that CMV infection is frequent and occurs early among the children who attend this day-care center. However, controlled studies using molecular epidemiology techniques are needed to define more precisely the role of day-care centers in CMV dissemination.

Multi-objective Parallel Particle Swarm Optimization for Day-ahead Vehicle-To-Grid Scheduling

This paper presents a methodology for multi-objective day-ahead energy resource scheduling for smart grids considering intensive use of distributed generation and Vehicle- To-Grid (V2G). The main focus is the application of weighted Pareto to a multi-objective parallel particle swarm approach aiming to solve the dual-objective V2G scheduling: minimizing total operation costs and maximizing V2G income. A realistic mathematical formulation, considering the network constraints and V2G charging and discharging efficiencies is presented and parallel computing is applied to the Pareto weights. AC power flow calculation is included in the metaheuristics approach to allow taking into account the network constraints. A case study with a 33-bus distribution network and 1800 V2G resources is used to illustrate the performance of the proposed method.

Stochastic Framework for Strategic Decision-making of Load-serving Entities for Day-ahead Market

The deregulation of electricity markets has diversified the range of financial transaction modes between independent system operator (ISO), generation companies (GENCO) and load-serving entities (LSE) as the main interacting players of a day-ahead market (DAM). LSEs sell electricity to end-users and retail customers. The LSE that owns distributed generation (DG) or energy storage units can supply part of its serving loads when the nodal price of electricity rises. This opportunity stimulates them to have storage or generation facilities at the buses with higher locational marginal prices (LMP). The short-term advantage of this model is reducing the risk of financial losses for LSEs in DAMs and its long-term benefit for the LSEs and the whole system is market power mitigation by virtually increasing the price elasticity of demand. This model also enables the LSEs to manage the financial risks with a stochastic programming framework.

Decision support tool for Virtual Power Players: Hybrid Particle Swarm Optimization applied to Day-ahead Vehicle-To-Grid Scheduling

This paper presents a decision support tool methodology to help virtual power players (VPPs) in the Smart Grid (SGs) context to solve the day-ahead energy resource scheduling considering the intensive use of Distributed Generation (DG) and Vehicle-To-Grid (V2G). The main focus is the application of a new hybrid method combing a particle swarm approach and a deterministic technique based on mixedinteger linear programming (MILP) to solve the day-ahead scheduling minimizing total operation costs from the aggregator point of view. A realistic mathematical formulation, considering the electric network constraints and V2G charging and discharging efficiencies is presented. Full AC power flow calculation is included in the hybrid method to allow taking into account the network constraints. A case study with a 33-bus distribution network and 1800 V2G resources is used to illustrate the performance of the proposed method.

Incentive-based demand response programs designed by asset-light retailers for day-ahead market

Following the deregulation experience of retail electricity markets in most countries, the majority of the new entrants of the liberalized retail market were pure REP (retail electricity providers). These entities were subject to financial risks because of the unexpected price variations, price spikes, volatile loads and the potential for market power exertion by GENCO (generation companies). A REP can manage the market risks by employing the DR (demand response) programs and using its' generation and storage assets at the distribution network to serve the customers. The proposed model suggests how a REP with light physical assets, such as DG (distributed generation) units and ESS (energy storage systems), can survive in a competitive retail market. The paper discusses the effective risk management strategies for the REPs to deal with the uncertainties of the DAM (day-ahead market) and how to hedge the financial losses in the market. A two-stage stochastic programming problem is formulated. It aims to establish the financial incentive-based DR programs and the optimal dispatch of the DG units and ESSs. The uncertainty of the forecasted day-ahead load demand and electricity price is also taken into account with a scenario-based approach. The principal advantage of this model for REPs is reducing the risk of financial losses in DAMs, and the main benefit for the whole system is market power mitigation by virtually increasing the price elasticity of demand and reducing the peak demand.

Sustentabilidade na construção metálica

O desenvolvimento sustentável é um dos grandes desafios dos nossos tempos com inúmeras consequências em várias áreas da nossa sociedade. É uma questão abrangente e essencial para a sobrevivência do modo de vida tal como o conhecemos actualmente. A construção sustentável tem um papel muito importante no desenvolvimento, não só ao nível económico mas também social e cultural. Embora não contemple a energia incorporada, a avaliação do ciclo de vida (ACV), no sector da construção, é um dos métodos mais comuns para avaliar o nível de sustentabilidade. Este trabalho visa os metais como uma das mais promissoras e actuais respostas do sector da construção às crescentes preocupações em relação ao desenvolvimento sustentável. O ferro e derivados são normalmente a base das construções metálicas, residindo no seu potencial de reutilização e reciclagem um dos seus principais factores de sustentabilidade. As estruturas metálicas apresentam características especificas que se coadunam com os requisitos da construção sustentável e que tornam este tipo de construção extremamente versátil e interessante. Neste trabalho, é efectuada uma abordagem sobre a construção metálica ao longo de três partes. A primeira parte é constituída por uma introdução histórica ao ferro e seus derivados enunciando exemplos de construções até aos nossos dias, e pela classificação dos vários tipos de metais e ligas metálicas. Na segunda parte, é abordado o conceito de sustentável e o seu enquadramento no sector da construção, e é feita uma introdução à metodologia de avaliação de ciclo de vida. Na terceira parte, é abordado um exemplo prático de uma estrutura metálica em que são elaboradas e comparadas três soluções. Na origem da diversidade dos elementos comparativos estão o tipo de aço, a origem da energia utilizada no seu fabrico e o tipo de solução técnica adoptada. O objectivo deste trabalho é compreender as repercussões do conceito de sustentabilidade no sector da construção, e desenvolver um método simplificado de avaliação dos impactos ambientais e económicos de soluções metálicas.

Cytomegalovirus infection in children with Down syndrome in a day-care center in Brazil

This study evaluates the transmission of CMV infection in 120 children aged 1 to 15 years with Down syndrome who attended a day-care center for handicapped children in São Paulo, Brazil. A blood sample was obtained from each children at the beginning of the study for detection of IgG and IgM cytomegalovirus (CMV) antibodies by an immunofluorescence assay. Samples of saliva and urine were obtained every 3 months from the children with CMV antibodies to detect shedding of the virus by culture in human foreskin fibroblasts, by detection of pp65 CMV-antigen and by a nested PCR assay. The prevalence of anti CMV-IgG antibodies was 76.6% (92/120), and IgM anti-CMV antibodies were detected in 13% (12/92) of the seropositive children. During the first viral evaluation, CMV was detected in the urine and/or saliva in 39/90 (43.3%) of the seropositive children. In the second and third evaluations, CMV was detected in 41/89 (46%) and in 35/89 (39.3%) children, respectively. Detection of CMV was shown both in urine and saliva in 28/39 (71.8%), 19/41(46.3%) and 20/35 (57.1%) of the children excreting the virus, respectively. Additionally, in 33/49 (67.4%) of the excreters CMV could be demonstrated in urine or saliva in at least two out of the three virological evaluations carried out sequentially in a six month period. Of the 28 initially seronegative children, 26 were re-examined for anti-CMV IgG antibodies about 18 months after the negative sample; seroconversion was found in 10/26 (38.5%). Taking all 536 samples of urine or saliva examined by virus culture and pp65 antigen detection during the study into account, 159 (29.6%) were positive by virus culture and 59 (11%) gave a positive result with the pp65 assay. These data demonstrate the high prevalence of CMV shedding and the high risk of CMV infection in children with Down syndrome attending a day-care center for mentally handicapped patients. The virus culture was more sensitive than the pp65 CMV antigen assay for CMV detection in both urine and saliva samples.

Outbreaks of human-herpes virus 6 (HHV-6) infection in day-care centers in Belém, Pará, Brazil

A total of 730 children aged less than 7 years, attending 8 day-care centers (DCCs) in Belém, Brazil were followed-up from January to December 1997 to investigate the occurrence of human-herpes virus 6 (HHV-6) infection in these institutional settings. Between October and December 1997 there have been outbreaks of a febrile- and -exanthematous disease, affecting at least 15-20% of children in each of the DCCs. Both serum- and- plasma samples were obtained from 401 (55%) of the 730 participating children for the detection of HHV-6 antibodies by enzyme-linked immunosorbent assay (ELISA), and viral DNA amplification through the nested-PCR. Recent HHV-6 infection was diagnosed in 63.8% (256/401) of them, as defined by the presence of both IgM and IgG-specific antibodies (IgM+/IgG+); of these, 114 (44.5%) were symptomatic and 142 (55.5%) had no symptoms (p = 0.03). A subgroup of 123 (30.7%) children were found to be IgM-/IgG+, whereas the remaining 22 (5.5%) children had neither IgM nor IgG HHV-6- antibodies (IgM-/IgG-). Of the 118 children reacting strongly IgM-positive ( > or = 30 PANBIO units), 26 (22.0%) were found to harbour the HHV-6 DNA, as demonstrated by nested-PCR. Taken the ELISA-IgM- and- nested PCR-positive results together, HHV-6 infection was shown to have occurred in 5 of the 8 DCCs under follow-up. Serological evidence of recent infections by Epstein-Barr virus (EBV) and parvovirus B19 were identified in 2.0% (8/401) and 1.5% (6/401) of the children, respectively. Our data provide strong evidence that HHV-6 is a common cause of outbreaks of febrile/exanthematous diseases among children attending DCCs in the Belém area.

Detection of Cryptosporidium sp. in non diarrheal faeces from children, in a day care center in the city of São Paulo, Brazil

The protozoan Cryptosporidium sp. has been frequently detected in faeces from children with persistent diarrhoea. This work achieved to investigate an outbreak of cryptosporidiosis, in a day care center, attending children of high socio-economic level, between 0 and six years old. The outbreak was detected through the network of public health, when stool samples, not diarrhoeic, were examined at the Parasitology Service of the Adolfo Lutz Institute. Among the 64 examined children, 13 (20.3%) showed oocysts of Cryptosporidium sp. in the faeces examined by Kinyoun technique: seven children one year old, three, two years old and three, three years old. Among the 23 examined adults, only a 22 years old woman, possibly having an immunocomprometiment, was positive. Clinical and epidemiological aspects were investigated by questionnaires, highlighting the occurrence of the outbreak in a very dry period.

Occurrence of enteroparasites in day care centers in Botucatu (São Paulo State, Brazil) with emphasis on Cryptosporidium sp., Giardia duodenalis and Enterobius vermicularis

The occurrence of the enteroparasites was verified in 279 children (0 to 6 years) of four municipal day cares of Botucatu/SP. Three samples of each child's feces were collected and processed by the methods of Hoffman-Pons-Janner, Faust and Ritchie and subsequent coloration of the fecal smear by the methods of Auramina-O and Ziehl-Neelsen modified for diagnosis of Cryptosporidium sp. and Graham method for diagnosis of Enterobius vermicularis. Of the analyzed children we verified a prevalence of intestinal parasitism in 53.40%, and the most frequent parasite was Giardia duodenalis (26.88%). Significant association was verified among enteroparasitosis, family income, maternal education and age; the lowest enteroparasite frequency occurred in children of families with larger income and higher education. It was observed that G. duodenalis is more prevalent in children from 0 to 4 years and E. vermicularis is more frequent in children between three and four years old. The high enteroparasite prevalence in day cares suggests complex structure in its epidemiology, where factors beyond sanitation should be considered.

An outbreak of scalp white piedra in a Brazilian children day care

White piedra is a superficial mycosis caused by Trichosporon spp. that affects the hair shaft of any part of the body. It is presented an outbreak of scalp white piedra seen in 5.8% of the children frequenting a day care in Northeastern of São Paulo State, Brazil. Mycological exam and culture identified T. cutaneum in all five cases, and scanning electron microscopy of nodules around hair shaft infected by Trichosporon spp. is demonstrated comparing them with those of black piedra and with nits of Pediculous capitis.

Electromagnetism based approach to Sector design in Waste Collection

For efficient planning of waste collection routing, large municipalities may be partitioned into convenient sectors. The real case under consideration is the municipality of Monção, in Portugal. Waste collection involves more than 1600 containers over an area of 220 km2 and a population of around 20,000 inhabitants. This is mostly a rural area where the population is distributed in small villages around the 33 boroughs centres (freguesia) that constitute the municipality. In most freguesias, waste collection is usually conducted 3 times a week. However, there are situations in which the same collection is done every day. The case reveals some general and specific characteristics which are not rare, but are not widely addressed in the literature. Furthermore, new methods and models to deal with sectorization and routing are introduced, which can be extended to other applications. Sectorization and routing are tackled following a three-phase approach. The first phase, which is the main concern of the presentation, introduces a new method for sectorization inspired by Electromagnetism and Coulomb’s Law. The matter is not only about territorial division, but also the frequency of waste collection, which is a critical issue in these types of applications. Special characteristics related to the number and type of deposition points were also a motivation for this work. The second phase addresses the routing problems in each sector: new Mixed Capacitated Arc Routing with Limited Multi-Landfills models will be presented. The last phase integrates Sectoring and Routing. Computational results confirm the effectiveness of the entire novel approach.

Heuristics and policies for online pickup and delivery problems

Master Thesis