Heat treatments for improved quality binder jetted molds for casting aluminum alloys

The objective of this paper was to investigate the most suitable heat treatment for casting molds manufactured by binder jetting. For this purpose, the printed molds were subjected to different heat treatments and the properties of the molds were analyzed. Tests were performed at different temperatures and times to investigate their effect on the water and volatile substances content; the joining among particles; and the porosity, roughness, and compression strength of the printed molds. Moreover, to relate the properties of the mold with the quality of the castings, aluminum alloy specimens were cast and the dimensional accuracy, surface roughness, mechanical strength, and porosity were evaluated. This research leads to the conclusion that the binder jetting process, using calcium sulfate powder, is useful for manufacturing molds for casting aluminum alloy. To improve the mold quality and, consequently, the casting quality, heat-treatment is necessary. The best mold properties were obtained at 250 °C for 1.5 h.S

Las cuevas de la Sierra de Atapuerca y el uso humano del paisaje kárstico durante el Pleistoceno (Burgos, España)

El karst de la Sierra de Atapuerca representa un interesante sistema multinivel, inactivo y heredado de antiguos niveles de base plio-pleistocenos, que alberga los enclaves prehistóricos más importantes para el conocimiento del poblamiento antiguo en Eurasia, y que fue declarado Patrimonio de la Humanidad en 2000 por la UNESCO. Estas cuevas se originan a partir de conductos subhorizontales con paleodrenajes en sentido SN, localizándose la zona de descarga en la cabecera del río Pico. Los conductos están organizados en tres niveles principales que aparecen colgados entre 90 y 60 m sobre el actual cauce del río Arlanzón, coincidiendo con los niveles de base generados por sus terrazas fluviales T2, T3 y T5. La incisión fluvial liberó de las aguas los conductos superiores mientras se excavaban los niveles inferiores del karst. Las cuevas que iban quedando accesibles fueron utilizadas por la fauna y los homininos, conservando un registro arqueo-paleontológico de más de 1,2 Ma

Obesity and asthma: an association modified by age

[Abstract] Background. Some studies indicate some causal relationship between obesity and asthma, while others show inconsistent results. Our objective was to evaluate the prevalence of asthma according to obesity in children. Methods. A cross-sectional study, following the ISAAC study methodology, was conducted on two randomly selected groups consisting of 6–7 year-old children (n = 7485) and 13–14 year-old adolescents (n = 8496). The asthma symptoms and potential risk factors were determined from the questionnaire. Overweight and obesity were defined based on the body mass index. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals. Results. Obesity was associated with an increase in wheezing ever (OR: 1.35) and exercise-induced asthma (OR: 1.62) in the 6–7 year-old group. No significant relationship was observed in the adolescent population. Conclusion. Obesity was associated with a higher prevalence of asthma in young children, but not in adolescents

Cross‐sectional study about impact of parental smoking on rhinitis symptoms in children

[Abstract] Objective. Assess the prevalence of rhinitis and exposure to environmental tobacco smoke (ETS) of children in our community and its relationship with symptoms of rhinitis Methods (design, setting, participants, main outcome measures). Cross‐sectional study using questionnaire on rhinitis of the International Study of Asthma and Allergies in Childhood, in children (6‐7 years) and adolescents (13‐14 years). Categories: “rhinitis ever”, “recent rhinitis”, “recent rhinoconjunctivitis”, “severe rhinoconjunctivitis”. Parental smoking: (i) neither parent smokes; (ii) only the mother smokes; (iii) only the father smokes; and (iv) both parents smoke. Odds ratio of the prevalence of symptoms of rhinitis according to ETS exposure was calculated using logistic regression. Results. 10 690 children and 10 730 adolescents. The prevalence of “rhinitis ever” in children: 29.4%, “recent rhinitis” 24%, “recent rhinoconjunctivitis” 11.5% and “severe rhinoconjunctivitis” 0.1%. In adolescents: 46.2%, 34.5%, 16.2% and 0.2%, respectively. Environmental tobacco smoke exposure in the home occurred in 51% of cases. Parental smoking was associated with a higher prevalence of forms of rhinitis in adolescents when only the mother was a smoker. In children when both parents were smokers. Conclusion. Rhinitis is highly prevalent in our community. Environmental tobacco smoke exposure is still very common. The relationship between ETS and rhinitis symptoms in children of this community is not as robust as that found for asthma

Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours : results from the COPPADIS cohort

The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose

Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

The inclusive transverse momentum ($p_{\rm T}$) distributions of primary charged particles are measured in the pseudo-rapidity range $|\eta|<0.8$ as a function of event centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV with ALICE at the LHC. The data are presented in the $p_{\rm T}$ range $0.15<p_{\rm T}<50$ GeV/$c$ for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor $R_{\rm{AA}}$ using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-$p_{\rm T}$ particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with $R_{\rm{AA}}\approx0.13$ at $p_{\rm T}=6$-7 GeV/$c$. Above $p_{\rm T}=7$ GeV/$c$, there is a significant rise in the nuclear modification factor, which reaches $R_{\rm{AA}} \approx0.4$ for $p_{\rm T}>30$ GeV/$c$. In peripheral collisions (70-80%), the suppression is weaker with $R_{\rm{AA}} \approx 0.7$ almost independently of $p_{\rm T}$. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

Shrinking a large dataset to identify variables associated with increased risk of Plasmodium falciparum infection in Western Kenya

Large datasets are often not amenable to analysis using traditional single-step approaches. Here, our general objective was to apply imputation techniques, principal component analysis (PCA), elastic net and generalized linear models to a large dataset in a systematic approach to extract the most meaningful predictors for a health outcome. We extracted predictors for Plasmodium falciparum infection, from a large covariate dataset while facing limited numbers of observations, using data from the People, Animals, and their Zoonoses (PAZ) project to demonstrate these techniques: data collected from 415 homesteads in western Kenya, contained over 1500 variables that describe the health, environment, and social factors of the humans, livestock, and the homesteads in which they reside. The wide, sparse dataset was simplified to 42 predictors of P. falciparum malaria infection and wealth rankings were produced for all homesteads. The 42 predictors make biological sense and are supported by previous studies. This systematic data-mining approach we used would make many large datasets more manageable and informative for decision-making processes and health policy prioritization