Landfill leachate from Municipal Solid Waste: Multi-technique approach for its fine characterization and determination of the thermodynamic and sequestering properties towards some toxic metals.

Landfill leachate is a multicomponent aqueous matrix generated by the percolation of rainwater into the body of a landfill. Considering its content of natural and xenobiotic components, it must be considered as a waste, whose composition depends on type of waste, biodegradation processes, rainwater, composition and compaction of waste and their age; these factors influence the transport, absorption, toxicity, bioaccumulation of the contaminants. Leachates sampled from landfill and downhill piezometers, in periods characterized by different rainfall, were studied by ATR-FTIR and SEM-EDX techniques; analyses were carried out on dried and calcinated residues obtained at T = 383 and 923 K, respectively. The chemical-physical characterization of all the leachates was carried out by using the official methods of analysis, obtaining for many metals and some organic contaminants exceedance of the concentrations with respect to the limits established by the Italian Legislative Decree 152/2006. From potentiometric titrations carried out at T = 298.15 K in NaCl(aq) and applying the Polyprotic Like model, each leachate resulted to have a different composition in terms of COOH and OH groups and various acid-base properties. The interacting ability of leachates with metal cations (Cd2+, Zn2+, Cu2+) was studied by potentiometric and voltammetric (only for Pb2+) techniques in NaCl (NaNO3 for Pb2+) aqueous solutions, at I = 0.15 mol dm-3 and T = 298.15 K, obtaining diverse speciation models and complexes of very different stability. The leachates sequestering ability towards the metal cations was quantified at various pH values using the pL0.5 parameter, proving that each leachate has a different strength of interaction towards the metals, that tends to increase with the pH and confirming that they behave as carriers of contaminants through the soil and towards groundwater, with the consequent problems of contamination and/or environmental disaster and risks for the human health.

Psychosocial condition after liver transplantation in children: review of the literature from 2006 to 2008.

Pediatric liver transplantation is the treatment of choice for end-stage liver disease of various causes. With most patients surviving long term after surgery, questions and concerns nowadays focus on morbidity and quality of life. Characterizing health-related quality of life (HRQOL) after liver transplantation provides a more complete estimate of the overall health of liver transplant candidates and recipients. HRQOL remains, however, a wide concept, with various interpretations in the literature, varying from medical assessment of physical status to considering various nonmedical aspects. Among the former aspects, concerns are commonly addressed about physical health and the psychological and/or social functioning of both transplanted children and their families. This detailed review of the most relevant papers analyzing of HRQOL after pediatric liver transplantation published between January 2006 and September 2008 includes the psychosocial aspects in children/adolescents, parents, and/or family members after liver transplantation, emphasizing limitations inherent to "measuring" and analyzing HRQOL aspects.

Quantum simulations of classical annealing processes.

We describe a quantum algorithm that solves combinatorial optimization problems by quantum simulation of a classical simulated annealing process. Our algorithm exploits quantum walks and the quantum Zeno effect induced by evolution randomization. It requires order 1/sqrt delta steps to find an optimal solution with bounded error probability, where delta is the minimum spectral gap of the stochastic matrices used in the classical annealing process. This is a quadratic improvement over the order 1/delta steps required by the latter.

Quantum approach to classical statistical mechanics.

We present a new approach to study the thermodynamic properties of d-dimensional classical systems by reducing the problem to the computation of ground state properties of a d-dimensional quantum model. This classical-to-quantum mapping allows us to extend the scope of standard optimization methods by unifying them under a general framework. The quantum annealing method is naturally extended to simulate classical systems at finite temperatures. We derive the rates to assure convergence to the optimal thermodynamic state using the adiabatic theorem of quantum mechanics. For simulated and quantum annealing, we obtain the asymptotic rates of T(t) approximately (pN)/(k(B)logt) and gamma(t) approximately (Nt)(-c/N), for the temperature and magnetic field, respectively. Other annealing strategies are also discussed.

PEGS in children: nursing considerations.

The nursing care of children with a percutaneous endoscopic gastrostomy (PEG) means caring for the whole of the child with a PEG. Even in the highly technical and specialized field of PEG, the main themes that characterize pediatric nursing are used as a reference guide (Dall'Oglio, 1996).

Organization of human homeobox genes.

The chromosomal localization of 17 human homeoboxes and the predicted primary sequence of the encoded homeodomains is reported. These homeoboxes are clustered in four complex HOX loci on chromosomes 2, 7, 12 and 17. Although the identification of human homeoboxes has not been completed, existing data permit preliminary conclusions on the origin and evolution of these complex loci to be drawn. The homeo-domains of one HOX locus can be unambiguously aligned to the homeodomains of the other HOX loci, so that corresponding homeodomains in all loci can share the maximal peptide sequence identity. This one-to-one correspondence of individual homeodomains in different chromosomal loci suggests the hypothesis of large-scale duplications of a single complex locus and subsequent spreading in different chromosomes. The existence of an ancestral complex locus might have predated the divergence of the arthropod/annelid and vertebrate evolutive lineages.

[Seroprevalence of antibodies against Trypanosoma cruzi in 13 departments of Uruguay]. / Seroprevalencia de anticuerpos contra Trypanosoma cruzi en 13 departamentos del Uruguay.

In 1985 a study was undertaken of the prevalence of Trypanosoma cruzi antibodies in 13 departments of Uruguay where transmission of the parasite by the vector Triatoma infestans persists. A total of 5,924 serum samples were selected using a probabilistic method--3,840 from individuals over the age of 12 (sample I) and 2,084 from subjects who were 12 years old (sample II). The population was classified according to place of residence (capital city, non-capital city, suburban area, and rural area). The percentage of positive sera detected by indirect immunofluorescence in the different departments ranged from 1 to 11%, and overall seroprevalence for the area was 3.4%. Based on the results obtained, it was possible to distinguish three areas: A, with seroprevalence from 6 to 11%; B, 2 to 3.2%, and C, 1 to 1.4%. In sample II from the Departments of Paysandú, Soriano, Flores, Florida, and Durazno, no cases of Chagas' disease were detected, which suggests that there is no active transmission of T. cruzi in this age group in the area studied. The number of persons estimated to have the disease was 36,952, or 1.3% of the total population of Uruguay and 4% of the population in the area surveyed. These seroprevalence figures are similar to those recorded in the province of Entre Ríos, Argentina, and in the neighboring municipalities of Rio Grande do Sul, Brazil.

Organization of human class I homeobox genes.

We report the genomic organization of 20 human class I homeoboxes and the predicted primary sequence of the encoded homeodomains. These homeoboxes are clustered in four complex HOX loci on chromosomes 2, 7, 12, and 17. The homeoboxes of one HOX locus can be aligned to the homeoboxes of the other HOX loci so that corresponding homeodomains in all loci can share the maximal peptide sequence identity. This correspondence of individual homeoboxes in different chromosomal loci suggests the hypothesis of large-scale duplications of a single complex locus. The existence of an ancestral complex locus might have predated the divergence of vertebrates and invertebrates.

Seroprevalencia de anticuerpos contra trypanosoma cruzi en 13 departamentos del Uruguay / Seroprevalence of trypanosoma cruzi in 13 deparments of Uruguay

In 1985 a study was undertaken of the prevalence of Trypanosoma cruzi antibodies in 13 departments of Uruguay where transmission of the parasite by the vector Triatoma infestans persists. A total of 5 924 serum samples were selected using a probabilistic method- 3 840 from individuals over the age of 12 (sample I) and 2 084 from subjects who where 12 years old (sample II). The population was classified acording to place of residence (capital city, non-capital city, suburban área, and rural área). The percentage of positive sera detected by indirect immunofluorescence in the different departments ranged from 1 to 11 percent, and overall seroprevalence for the área was 3.4 percent. Based on the results obtained, it was possible to distinguish three áreas: A, which seroprevalence from 6 to 11 percent; B, 2 to 3.2 percent, and C, 1 to 4 percent. In sample II from the Departments of Paysandu, Soriano, Flores, Florida, and Durazno, no cases of Chagas' disease were detected which suggests that there is no active transmission of T. cruzi in this age group in the área studied. The number of persons estimated to have the disease was 36 952, or 1.3 percent of the total population of Uruguay and 4 percent of the population in the área surveyed. These seroprevalence figures are similar to those recorded in the povince of Entre Rios, Argentina, and in the neighboring municipalities of Rio Grande do Sul, Brazil