Understanding how youth perceive household economic hardship and how it relates to their behavior is vital given associations between hardship and behavioral development. Yet, most studies ignore youth’s own perceptions of economic hardship, instead relying solely on caregiver reports. Moreover, the literature has tended to treat economic hardship as a stable force over time, rather than a volatile one that varies month-to-month. This study addressed extant limitations by collecting monthly measures of economic hardship, specifically caregiver- and youth-reported material deprivation and youth-reported financial stress, and youth internalizing and externalizing problems from 104 youth–caregiver dyads (youth: 14–16 years, 55% female, 37% Black, 43% White) over nine months. We examined month-to-month variability of these constructs and how youth-reports of material deprivation and financial stress predicted their behavior problems, controlling for caregiver-reports of material deprivation. We found that hardship measures varied month-to-month (ICCs = 0.69–0.73), and youth-reported material deprivation positively predicted internalizing when examining both within- and between-individual variability (β = .19–.47). Youth-reported financial stress positively predicted within-individual variation in externalizing (β = .18), while youth reports of material deprivation predicted externalizing when looking between families (β = .41). Caregiver-reported material deprivation was unrelated to youth behavior when accounting for youth perceptions of economic hardship.

One of the most important aspects of genetic evaluation (GE) is the definition of contemporary groups (CG), commonly defined as animals of the same sex born in the same herd, year and season. The objective of this study was to use an aridity index (AI) to classify season and evaluate the implications on the GE of Braunvieh cattle. A data set with 32 777 and 22 448 birth weight (BW) and weaning weight adjusted to 240 days (WW) records, respectively, was used to compare two methods of classification of climatic seasons to be used in the definition of CG for GE models. The first method considered rain season criterion (RC), and the second method is a proposed classification using an AI. Both methods were compared using two approaches. The first approach examined differences in mixed models using the RC and AI season to select the best model for BW and WW, evaluated by different goodness of fit measures. The second approach considered fitting a GE model including the season classifications into the CG structure. Lower probability values for season effect and better goodness of fit measures were obtained when the season was classified according to the AI. Results showed that although differences are small, the AI allows a better model fitting for live-weight traits than RC and revealed a re-ranking effect on expected progeny differences data. Further analysis with other traits would demonstrate the extended utility of AI indicators to be considered for fitting models under a climatic change environment.

We study the dynamics of atomization of a liquid column by a coaxial gas flow with varying gas pressures. Specifically, we analyse how the gas density increase associated with elevated gas pressures in the ambient and co-flowing gas jet influences the liquid destabilization and breakup process, as well as the resulting droplet formation and dispersion. We present new experimental results for a coaxial liquid–gas atomizer operating in a high-pressure environment, with gas–liquid momentum ratio in the range $M = 5\unicode{x2013}56$ and pressurized gas densities $\rho _g/\rho _0 = 1\unicode{x2013}5$, where $\rho _0$ is the ambient gas density at standard conditions. High-speed shadowgraphy images are used to quantify the spatially and temporally varying liquid–gas interface in the spray near-field. Liquid core lengths, spreading angles and other spray metrics are presented, and the influence of gas density is identified from the comparison with atomization at atmospheric conditions. In the spray mid-field, phase Doppler interferometry is used in conjunction with laser Doppler velocimetry to quantify the droplet size and velocities, as well as their radial variations across the spray. Results show an increase in droplet size at elevated ambient pressures, when keeping the gas–liquid momentum ratio constant. Finally, we show that these observations are in line with predictions from the Kelvin–Helmholtz and Rayleigh–Taylor instabilities, both of which are relevant to the gas–liquid atomization process.

The aim of the present study was to develop and validate a test to evaluate dietitian's clinical competence (CC) about nutritional care in patients with early chronic kidney disease (CKD). The study was conducted through five steps: (1) CC and its dimensions were defined; (2) test items were elaborated, and choice of response format and scoring system was selected; (3) content and face validity were established; (4) test was subjected to a pilot test and those items with inadequate performance were removed; (5) criterion validity and internal consistency for final validation were established. A 120-items test was developed and applied to 207 dietitians for validation. Dietitians with previous CKD training obtained higher scores than those with no training, confirming the test validity criterion. According to item analysis, Cronbach's α was 0⋅85, difficulty index 0⋅61 ± 0⋅22, discrimination index 0⋅26 ± 0⋅15 and inter-item correlation 0⋅19 ± 0⋅11, displaying adequate internal consistency.

A canonical co-axial round-jet two-fluid atomizer where atomization occurs over a wide range of momentum ratios: $M=1.9 - 376.4$ is studied. The near field of the spray, where the droplet formation process takes place, is characterized and linked to droplet dispersion in the far field of the jet. Counterintuitively, our results indicate that in the low-momentum regime, increasing the momentum in the gas phase leads to less droplet dispersion. A critical momentum ratio of the order of $M_c=50$, that separates this regime from a high-momentum one with less dispersion, is found in both the near and far fields. A phenomenological model is proposed that determines the susceptibility of droplets to disperse beyond the nominal extent of the gas phase based on a critical Stokes number, $St=\tau _p/T_E=1.9$, formulated based on the local Eulerian large scale eddy turnover time, $T_E$, and the droplets’ response time, $\tau _p$. A two-dimensional phase space summarizes the extent of these different regimes in the context of spray characteristics found in the literature.

Despite the well-known relevance of twin studies in the medical and social sciences and the growing number of twin registries throughout the world, Latin America has not fully incorporated into the twin research community. We describe the first steps taken toward developing a twin registry in Mexico: its aim, organization, recruiting potential and main short-term objectives.