An investigation of nodal structures and the construction of trial wave functions

The factors influencing the quality of the nodal surfaces, namely, the atomic basis set, the single-particle orbitals, and the configurations included in the wave-function expansion, are examined for a few atomic and molecular systems. The following empirical rules are found: the atomic basis set must be fairly large, complete active space and natural orbitals are usually better than Hartree-Fock orbitals, multiconfiguration expansions perform better than single-determinant wave functions, but only few configurations are effective and their choice is suggested by symmetry considerations, while too long determinantal expansions spoil the nodal surfaces. These rules allow us to reduce the nodal error and to compute the best fixed node-diffusion Monte Carlo energies for a series of dimers of first-row atoms

Quantitative ultrasound applied to metacarpal bone in infants.

Aim. To provide bone status assessment in infancy using quantitative ultrasound (QUS) applied to second metacarpus.Methods. 103 healthy term infants and 3 patients with rickets, aged ≤ 12 months, underwent metacarpal QUS evaluation using QUS DBM Sonic Aurora IGEA (MO, Italy), which measures speed of sound (mcSOS) and bone transmission time (mcBTT).Results. In the total sample, median (interquartile range) of mcSOS was 1640.00 (26.0) m/s and mcBTT 0.82 (0.21) µs. Moreover, reference values for age were obtained based on estimation of the lower and upper percentiles. We observed a statistical significant difference between groups of age for mcSOS (p = 0.016). In a multiple linear regression model, we found a relation between age at enrolment and mcSOS (β = −0.608; p = 0.000) and mcBTT (β = −0.819; p = 0.001). A positive correlation between mcSOS and mcBTT has been observed (r = 0.631; p = 0.000). All the patients with rickets showed values of mcSOS and mcBTT lower than the 10th percentile.Conclusion. Our findings show that this new simple technique appears to be a promising tool for monitoring bone mineral status in pediatric clinical practice and in early life. Furthermore, it could be considered a useful method to investigate and to monitor the role of different factors on programming of bone health and it should be tested as a new method for monitoring subjects with rickets during therapy

Unsilencing of native leptin receptors (LepR) in hypothalamic SF1 neurons does not rescue obese phenotype in LepR-deficient mice

Leptin receptor (LepR) signaling in neurons of the ventromedial nucleus of the hypothalamus (VMH), specifically those expressing steroidogenic factor-1 (SF1), have been proposed to play a key role in controlling energy balance. By crossing LepR-silenced (LepR) mice to those expressing SF1-Cre, we unsilenced native LepR specifically in the VMH and tested whether SF1 neurons in the VMH are critical mediators of leptin's effect on energy homeostasis. LepR x SF1-Cre (KO/Tg+) mice were metabolically phenotyped and compared to littermate controls that either expressed or were deficient in LepR. Leptin-induced pSTAT3 was present in the VMH of KO/Tg+ mice and absent in other hypothalamic nuclei. VMH leptin signaling did not ameliorate obesity resulting from LepR-deficiency in chow-fed mice. There was no change in food intake or energy expenditure when comparing complete LepR-null mice to KO/Tg+ mice, nor did KO/Tg+ show improved glucose tolerance. The presence of functional LepR in the VMH mildly enhanced sensitivity to the pancreatic hormone amylin. When maintained on high fat diet (HFD), there was no reduction in diet-induced obesity in KO/Tg+ mice, but KO/Tg+ mice had improved glucose tolerance after 7 weeks on HFD compared to LepR-null mice. We conclude that LepR signaling in the VMH alone is not sufficient to correct metabolic dysfunction observed in LepR-null mice

An overview on the natural enemies of Rhynchophorus palm weevils, with focus on R. ferrugineus.

Rhynchophorus palm weevils are large insects belonging to the family Dryophthoridae. All Rhynchophorus species are polyphagous and have a similar life history but some are major pests because of the serious economic damage they cause, in particular to several species of the family Arecaceae. Here we review the natural enemies of Rhynchophorus species in both their native and introduced regions of the world, to assess the possibility of biological control of this taxon. Moreover, particular attention is paid to the well-studied and harmful species Rhynchophorus ferrugineus, about which more information is available, and to its natural enemies in the Mediterranean region, because the impact of this pest in this recently colonized area is particularly remarkable and also the recent trend in species management is looking for indigenous natural enemies. More than 50 natural enemies have been reported to attack Rhynchophorus species, even if most of them are associated to R. ferrugineus (Olivier), highlighting the lack of information on the other species of the genus. Pros and cons of all the biological control agents are then discussed: among the considered organisms, fungi are noteworthy to be considered for inclusion in integrated pest management programs. Overall, our overview underlines the need to increase knowledge on natural enemies of all the species of the genus Rhynchophorus, to isolate more virulent strains and to determine the optimum conditions for the actions of the biocontrol agents

U.V.A.C. MONITORING OF HEAVY METALS IN CONTROLLED MILK AND ITS PRODUCTS IN TURIN DURING 2007

The contamination of food by chemical is a worldwide public health concern and is a leading cause of trade problems internationally. Contamination may occur through environmental pollution of air, water and soil, such as heavy metals (As, Cd, Cr, Fe, Hg, Pb), PCB and dioxins, or through the intentional use of various pesticides and other agrochemicals. The AA controlled, during 2007, 26 samples of milk, 2 samples of dessert and 32 samples of cheese coming from UE to the area of the City of Turin. The collected demonstrate that the environmental situation is under control and the milk, dessert and cheese fully satisfy this health requisite

Evaluation of indigenous entomopathogenic nematodes as potential biocontrol agents against popillia japonica (Coleoptera: Scarabaeidae) in Northern Italy

The natural presence of entomopathogenic nematodes (EPNs) has been investigated in the Piedmont region (Northern Italy) in areas infested by the Japanese beetle Popillia japonica. Thirty-nine out of 155 soil samples (25.2%) were positive for EPNs. Most of the samples contained only steinermatids (92.3%), 5.1% contained heterorhabditids, and one sample (2.6%) contained both genera. All the recovered isolates were identified at species level both morphologically and molecularly. Steinernema carpocapsae was the most abundant and it was mainly distributed in open habitats, such as perennial meadows, uncultivated soils, and cropland, characterized by sandy loam soil texture and acidic pH. Steinernema feltiae has been found associated mainly with closed habitats such as coniferous and deciduous woodland, characterized by sandy loam-texture and extremely acidic soil. The three isolates of Heterorhabditis bacteriophora were collected only in open habitats (perennial meadows and uncultivated fields) characterized by strongly acidic soils with sandy loam texture. The virulence of all EPN natural strains was evaluated by laboratory assays against P. japonica third-instar larvae collected during two different periods of the year (spring, autumn). The results showed that larval mortality was higher for pre-wintering larvae than post-wintering ones. The five more promising EPN isolates were tested in the semi-field assay in which H. bacteriophora natural strains have been shown to be more efficient in controlling P. japonica grubs. All of these results are finally discussed considering the use of these natural EPNs as biological control agents against P. japonica, within an eco-friendly perspective of management

HEAVY METALS CONTAMINATION IN FISH OF THE LIGURIAN SEA

Aim of this investigation was to evaluate heavy metals contamination (mercury, cadmium and lead) in fish and shellfish from Ligurian Sea. 58 muscle samples (45 fish and 13 shellfish) were collected and analyzed. 20 samples exceeded the maximum residue limits (MRLs) set by regulation for mercury (16 fish and 4 shellfish samples), while only one fish sample was not consistent with the MRL for lead. Therefore, 35,8% of Ligurian fishing turned out to be not adequate and potentially harmful for consumers. In order to estimate the real risk for human health it is necessary to enforce this study, correlating the results with fish species and with the effective fish consumption

Influence of parent-adolescent relationship on early sexual debut and number of partners among Mexican youth

Objective: To evaluate whether parents-adolescents relationship was associated with early sexual debut and having multiple partners in a low socioeconomic suburb in Mexico City. Methods: An anonymous questionnaire about sexual activity and relationships with parents during adolescence was responded by 936 participants, aged 20-30. Logistic regression was conducted. Results: The majority of participants reported being sexually active (78.3%). Among them, 70% of males and 55% of females had first sex before age 18. Good communication with parents during adolescence was inversely associated with sexual debut 2 sexual partners (OR=0.47; IC95% 0.33-0.68). Sexual debut <18 was associated with having had multiple partners (OR=3.86; IC95% 2.60-5.73). Conclusion: Good parental communication during adolescence may help prevent adolescents from choosing early sexual debut and having multiple partners and, consequently, from acquiring sexually transmitted diseases. Efforts are necessary to support parents in their relationship with their adolescent children

Mosquitoes LTR Retrotransposons: A Deeper View into the Genomic Sequence of Culex quinquefasciatus

A set of 67 novel LTR-retrotransposon has been identified by in silico analyses of the Culex quinquefasciatus genome using the LTR_STRUC program. The phylogenetic analysis shows that 29 novel and putatively functional LTR-retrotransposons detected belong to the Ty3/gypsy group. Our results demonstrate that, by considering only families containing potentially autonomous LTR-retrotransposons, they account for about 1% of the genome of C. quinquefasciatus. In previous studies it has been estimated that 29% of the genome of C. quinquefasciatus is occupied by mobile genetic elements