The methodology and results of the thermal and hydraulic design for a solar heating field of an elementary school's semi-olympic pool is presented. Improved flat solar collectors with copper tube and aluminum fins were used. From own experiences, many Mexican solar fields do not operate correctly because of their poor flow balance (irrigation) , may be due to lack of attention given to this aspect. That's why the research of this work focuses on studying the behavior of the pressure drop in a hydraulic arrangement, particularly of this facility, in which all collector batteries are connected in parallel. Previously two solar collectors were sent to a specialized laboratory for certification tests, obtaining the optimum water flow value for maximum thermal efficiency. The results show an optimum range between 4 and 11 L/min. On the other hand, the development of a thermal model based on a temporal energy balance, allowed us to determine that the optimum solar heating area is around 338 m 2 , using 195 flat-coated solar collectors, with copper tube and aluminum fin. For this heating system a water volume/solar collection area relation, called REVA, of 1.45m 3 /m 2 was obtained. Referred to the hydraulic design and using the program EPANET 2.0 it was found that in the proposed arrangement, 192 solar collectors were irrigated with the optimal range and only 2 solar collectors were below the lower range at 3 L/min. NomenclatureA C solar surface collection (m 2 )

Toxocarosis is entheroparasitosis frequently present in dogs and cats which is maintained in the environment by the infestation and reinfestation of the hosts, by the ingestion of food and soil contaminated with larvated eggs, ingestion of larvae in tissue of paratenic larvae (rats and birds), by transplacentary migration of a female dog to their fetus, transmammary passage in milk, or ingestion of larvae or faeces from puppets infested (1) . Human subjects, mainly children, are infested by the accidental ingestion of embryonated eggs from the soil contaminated by the dogs, and even when most of the seropositive patients may be asymptomatic, the parasite may cause fever, hepatomegaly, esplenomegaly, hypergammaglobulinaemia, eosinophilia, adenopathies and disorders of central nervous system, myocardium, eyes, skin, respiratory symptoms and even as a fatal disease (2,3) . The aim of the present study was to analyse the relationship of nutritional status in Toxocara canis infested children and adolescents in the State of Mexico. A study comprising 108 patients between 2 and 16 years of age, both male and female (56 men and 52 women) from the State of Mexico was carried out. Their T. canis antibodies' levels were measured by means of an ELISA test. The BMI was evaluated in order to assess nutritional status. We used a chi-square and risk test (OR) in order to compare the difference between groups and the relationship between nutritional status and parasitosis. A regression analysis was also conducted between antibody presence and BMI. According to standards established by the World Health Organization (2004), 49 % of the participants had a normal BMI; 30 % showed low weight, first-and second-degree malnutrition; and the remaining 21 % showed overweight and first-degree obesity. Twenty-five individuals (fourteen males and eleven females) between 2 and 14 years of age presented antibodies for T. canis larva migrans. From these parasitised children and teenagers 48 % showed a normal BMI; 36 % showed underweight and first-and second-degree malnutrition; and 16 % showed overweight and first-degree obesity. Nutritional status was not associated with toxocariasis serology; risk factors (RF) are low, indicating that other factors may be more important in the presence of the disease. The lack of a relation between BMI and parasitosis was confirmed by the null correlation between seropositivity and BMI (r = 0.08). It can be concluded that nutritional status is not associated with seropositivity for Toxocara. Parasitic infections are highly prevalent in populations of developing countries, affecting mostly those groups with higher nutritional deficit; therefore it is intended to extend the current study with the purpose of relating toxocariasis pathophysiology with the nutritional status of patients.