Self-diagnostic composites have become increasingly popular for structural health monitoring due to their ability to develop load-bearing strain sensors. Piezoelectric cement composites, in ...particular, represent an emerging area of research with vast potential for developing innovative self-powered or ultra-low power consumption sensors. In this context, this paper presents Pypiezo-GO, a software tool designed for the electromechanical characterization of reduced graphene oxide (rGO)-cement composites. The software tool, developed as an online cloud computing platform, accesses a database organized into DataFrame structures. The database contains the measurements from a set of experiments conducted on rGO-cement samples, including open circuit potential, cyclic voltammetry, and compressive testing. On this basis, Pypiezo-GO allows extracting the electrical properties of the samples, including their capacitance and piezoelectric factors. Furthermore, the platform enables the comparison of experimental time series with numerical predictions from a lumped circuit model implemented in MATLAB/Simulink, which is also included in this contribution. The presented software code is intended to represent a valuable tool for the development of new piezoelectric cement composites for strain self-sensing applications.
We study the Hall response of topologically trivial mobile impurities (Fermi polarons) interacting weakly with majority fermions forming a Chern-insulator background. This setting involves a rich ...interplay between the genuine many-body character of the polaron problem and the topological nature of the surrounding cloud. When the majority fermions are accelerated by an external field, a transverse impurity current can be induced. To quantify this polaronic Hall effect, we compute the drag transconductivity, employing controlled diagrammatic perturbation theory in the impurity-fermion interaction. We show that the impurity Hall drag is not simply proportional to the Chern number characterizing the topological transport of the insulator on its own-it also depends continuously on particle-hole breaking terms, to which the Chern number is insensitive. However, when the insulator is tuned across a topological phase transition, a sharp jump of the impurity Hall drag results, for which we derive an analytical expression. We describe how to experimentally detect the polaronic Hall drag and its characteristic jump, setting the emphasis on the circular dichroism displayed by the impurity's absorption rate.
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Use of polluting cooking fuels generates household air pollution (HAP) containing health-damaging levels of fine particulate matter (PM2.5). Many global epidemiological studies rely ...on categorical HAP exposure indicators, which are poor surrogates of measured PM2.5 levels. To quantitatively characterize HAP levels on a large scale, a multinational measurement campaign was leveraged to develop household and personal PM2.5 exposure models.
The Prospective Urban and Rural Epidemiology (PURE)-AIR study included 48-hour monitoring of PM2.5 kitchen concentrations (n = 2,365) and male and/or female PM2.5 exposure monitoring (n = 910) in a subset of households in Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania and Zimbabwe. PURE-AIR measurements were combined with survey data on cooking environment characteristics in hierarchical Bayesian log-linear regression models. Model performance was evaluated using leave-one-out cross validation. Predictive models were applied to survey data from the larger PURE cohort (22,480 households; 33,554 individuals) to quantitatively estimate PM2.5 exposures.
The final models explained half (R2 = 54%) of the variation in kitchen PM2.5 measurements (root mean square error (RMSE) (log scale):2.22) and personal measurements (R2 = 48%; RMSE (log scale):2.08). Primary cooking fuel type, heating fuel type, country and season were highly predictive of PM2.5 kitchen concentrations. Average national PM2.5 kitchen concentrations varied nearly 3-fold among households primarily cooking with gas (20 μg/m3 (Chile); 55 μg/m3 (China)) and 12-fold among households primarily cooking with wood (36 μg/m3 (Chile)); 427 μg/m3 (Pakistan)). Average PM2.5 kitchen concentration, heating fuel type, season and secondhand smoke exposure were significant predictors of personal exposures. Modeled average PM2.5 female exposures were lower than male exposures in upper-middle/high-income countries (India, China, Colombia, Chile).
Using survey data to estimate PM2.5 exposures on a multinational scale can cost-effectively scale up quantitative HAP measurements for disease burden assessments. The modeled PM2.5 exposures can be used in future epidemiological studies and inform policies targeting HAP reduction.
The majority of the research on school suspension practices has focused on individual student-level factors and their relationship to school suspension practices. A substantial number of studies have ...examined race and/or disability status as predictors of suspension (Camacho & Krezmien,
2018
; Krezmien, Travers, & Camacho,
2017
; Sullivan, Klingbeil, & Van Norman,
2013
; Vincent, Sprague, & Tobin, 2012; Wright, Morgan, Coyne, Beaver, & Barnes,
2014
). They have consistently found that African American students and students with disabilities are more likely to be suspended from school compared to White students and students without disabilities. Fewer studies have focused on school-level factors that are associated with disproportionate suspension practices. These studies have found that secondary schools suspend more students than elementary schools (Butler, Lewis, Moore, & Scott,
2012
; Camacho & Krezmien,
2018
). Schools with lower academic achievement (Camacho & Krezmien,
2018
; Skiba et al.,
2014
), higher retention rates (Christle, Nelson, & Jolivette,
2004
), and more highly qualified teachers (Camacho & Krezmien,
2018
; Losen, Simmons, Staudinger-Poloni, Rausch, & Skiba,
2003
) had lower suspension rates. Schools with higher percentages of Black students (Skiba et al.,
2014
), higher dropout rates (Christle et al.,
2004
), and higher mobility rates (Camacho & Krezmien,
2018
; Hemphill, Plenty, Herrenkohl, Toumbourou, & Catalano,
2014
) placed students at higher risk for suspension. Despite these consistent findings, there has been relatively little research examining school discipline policies (Fenning et al.,
2008
) and the relationship between school discipline policies and discipline outcomes.
In this paper, twelve substituted
O
-geranylchalcones were synthesized and evaluated for their leishmanicidal and trypanocidal activity. All the synthesized compounds showed selective activity ...against
L. mexicana
strain in comparison to
T. cruzi
strain.
O
-geranyl chalcone
5j
substituted with a
meta
-NO
2
group in B ring, showed the highest selectivity (IS = 21.46). Cytotoxicity studies using murine macrophages J774.A1 showed that F and Cl substituents on the
para
position on the B ring, displayed the less toxicity as in compounds
5f
and
5i
. Calculated ADME properties indicated that the obtained chalcones presented a good skin permeability, making them adequate candidates for local treatment of cutaneous leishmaniasis.
This research focused on the nanosecond (Nd: YAG-1064nm) laser pulse effect on the optical and morphological properties of chemically modified multi-walled carbon nanotubes (MWCNT). Two suspensions ...of MWCNT in tetrahydrofuran (THF) were prepared, one was submitted to laser pulses for 10min while the other (blank) was only mechanically homogenized during the same time. Following the laser irradiation, the suspension acquired a yellow-amber color, in contrast to the black translucent appearance of the blank. UV-vis spectroscopy confirmed this observation, showing the blank a higher absorption. Additionally, photoluminescence measurements exhibited a broad blue-green emission band both in the blank and irradiated suspension when excited at 369nm, showing the blank a lower intensity. However, a modification in the excitation wavelength produced a violet to green tuning in the irradiated suspension, which did not occur in the blank. Lastly, the electron microscopy analysis of the treated nanotubes showed the abundant formation of amorphous carbon, nanocages, and nanotube unzipping, exhibiting the intense surface modification produced by the laser pulse. Nanotube surface modification and the coexistence with the new carbon nanostructures were considered as the conductive conditions for optical properties modification.
•Nanotube surface modification is achieved by laser irradiation.•Laser irradiated nanotube suspension exhibits photoluminescence.•Carbon nanostructures are generated by laser irradiation on carbon nanotubes.
INTRODUCTIONHuntington disease (HD) is a hereditary neurodegenerative disorder. Thanks to predictive diagnosis, incipient clinical characteristics have been described in the prodromal phase. ...OBJECTIVETo compare performance in cognitive tasks of carriers (HDC) and non-carriers (non-HDC) of the huntingtin gene and to analyse the variability in performance as a function of disease burden and proximity to the manifest stage (age of symptom onset). METHODA sample of 146 participants in a predictive diagnosis of HD programme were divided into the HDC (41.1%) and non-HDC groups (58.9%). Mathematical formulae were used to calculate disease burden and proximity to the manifest stage in the HDC group; these parameters were correlated with neuropsychological performance. RESULTSSignificant differences were observed between groups in performance on the Mini-Mental State Examination (MMSE), Stroop-B, Symbol-Digit Modalities Test (SDMT), and phonological fluency. In the HDC group, correlations were observed between disease burden and performance on the MMSE, Stroop-B, and SDMT. The group of patients close to the manifest stage scored lowest on the MMSE, Stroop-B, Stroop-C, SDMT, and semantic verbal fluency. According to the multivariate analysis of covariance, the MMSE effect shows statistically significant differences in disease burden and proximity to onset of symptoms. CONCLUSIONSMembers of the HDC group close to the manifest phase performed more poorly on tests assessing information processing speed and attention. Prefrontal cognitive dysfunction appears early, several years before the motor diagnosis of HD.
Household air pollution (HAP) from cooking with solid fuels has been associated with adverse respiratory effects, but most studies use surveys of fuel use to define HAP exposure, rather than on ...actual air pollution exposure measurements.
To examine associations between household and personal fine particulate matter (PM2.5) and black carbon (BC) measures and respiratory symptoms.
As part of the Prospective Urban and Rural Epidemiology Air Pollution study, we analyzed 48-h household and personal PM2.5 and BC measurements for 870 individuals using different cooking fuels from 62 communities in 8 countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Self-reported respiratory symptoms were collected after monitoring. Associations between PM2.5 and BC exposures and respiratory symptoms were examined using logistic regression models, controlling for individual, household, and community covariates.
The median (interquartile range) of household and personal PM2.5 was 73.5 (119.1) and 65.3 (91.5) μg/m3, and for household and personal BC was 3.4 (8.3) and 2.5 (4.9) x10−5 m−1, respectively. We observed associations between household PM2.5 and wheeze (OR: 1.25; 95%CI: 1.07, 1.46), cough (OR: 1.22; 95%CI: 1.06, 1.39), and sputum (OR: 1.26; 95%CI: 1.10, 1.44), as well as exposure to household BC and wheeze (OR: 1.20; 95%CI: 1.03, 1.39) and sputum (OR: 1.20; 95%CI: 1.05, 1.36), per IQR increase. We observed associations between personal PM2.5 and wheeze (OR: 1.23; 95%CI: 1.00, 1.50) and sputum (OR: 1.19; 95%CI: 1.00, 1.41). For household PM2.5 and BC, associations were generally stronger for females compared to males. Models using an indicator variable of solid versus clean fuels resulted in larger OR estimates with less precision.
We used measurements of household and personal air pollution for individuals using different cooking fuels and documented strong associations with respiratory symptoms.
•Multi-country study of measured personal and household air pollution.•Measured air pollution exposure associated with respiratory symptoms.•Household measures more strongly associated than personal measures.•PM2.5 measures more strongly associated than black carbon measures.•Larger associations for female compared to male individuals.
A methodological proposal for estimating environmental flows in large projects approved by Agencia Nacional de Licencias Ambientales (ANLA) in Colombian rivers was developed. The project is the ...result of an agreement between the MADS and the Universidad Nacional de Colombia, Bogotá (UNC). The proposed method begins with an evaluation of hydrological criteria,continues with a hydraulic and water quality validation, and follows with the determination of habitat integrity. This is an iterative process that compares conditions before and after the project construction and allows to obtain the magnitude of a monthly flow that, besides preserving the ecological functions of the river, guarantees the water uses downstream. Regarding to the biotic component, the proposal includes the establishment and monitoring of biotic integrity indices for four aquatic communities (periphyton, macroinvertebrates, riparian vegetation, and fish). The effects that flow reduction may produce in the medium and long term can be assessed by these indices. We present the results of applying the methodology to several projects licensed by the MADS.
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