Cross-sectional and longitudinal relationships between psychological violence and teacher burnout.

OBJECTIVE: This study aimed to identify cross-sectional and longitudinal relationships between psychological violence (PV) and burnout after two years of follow-up. METHODS: This is a longitudinal study involving 430 public school teachers from a city in southern Brazil. PV was defined as insults by students, humiliation or embarrassment by colleagues or superiors or threats by any member of the school. Burnout was measured using the emotional exhaustion (EE) and depersonalization (DP) subscales of the Maslach Burnout Inventory-Human Services Survey. Analyses were performed using structural equation models in R. RESULTS: Younger age (ß = - .167) and poor/fair relationship with students (ß = .275) had a direct effect on PV. Temporary employment (ß = - .111) and poor/fair perception of the number of students in the classroom (ß = .124) had a direct effect on EE. Cross-sectionally, PV showed a direct effect at both T0 and T1 on EE (T0: ß = .435; T1: ß = .334) and on DP (T0: ß = .332; T1: ß = .325). Longitudinally, PV at T0 did not have a significant direct effect on burnout at T1. However, indirect effects of PV on EE (ß = .459) and DP (ß = .428) at T1 were observed. CONCLUSIONS: The effect of PV on burnout occurs in a short period of time. However, the long-term effect should be considered because there is a cumulative burden of exposure to violence over time.

Adulteration identification in raw milk using Fourier transform infrared spectroscopy.

Adulteration of milk is a common practice that concerns regulatory agencies, industry, and the population. Despite the growing need for checking adulteration, the current methods employed generally have low performance and are highly dependent on manual labor. This study aims to calibrate and validate a compact equipment (MilkoScan FT1) that adopts a Fourier transform infrared spectroscopy methodology to monitor adulteration in raw milk. Almost 2500 milk samples were used for reference spectrum construction and 1650 samples were used to validate the identification of the following five most commonly used adulterants (at three different concentrations each): (1) cornstarch, (2) sodium bicarbonate, (3) sodium citrate, (4) formaldehyde, and (5) saccharose, plus the additions of two levels of water or whey. To define the calibration with the best performance in milk adulteration identification, 12 calibrations involving 8, 10, 12, 14, 16, or 18 factors, with one or two outlier eliminations, were developed. The results of sensitivity and specificity analyses, as well as Kruskal-Wallis and Dunn multiple comparison tests, revealed that the calibration that best identified the adulterants was the one involving 14 factors, with a single elimination of outliers, exhibiting for all adulterants simultaneously, 84% sensitivity and 100% specificity. The calibration showed excellent sensitivity to cornstarch (>98%), sodium bicarbonate (100%), sodium citrate (99%), and formaldehyde (>84%), indicating that this calibration has good capacity for adulteration detection. Thus, this methodology is a viable option for the dairy industry to identify adulteration of raw milk.