38 research outputs found
Potential risks of dietary exposure to chlorpyrifos and cypermethrin from their use in fruit/vegetable crops and beef cattle productions
The active ingredients (a.i.) used as pesticides vary across regions. Diet represents the main source of chronic exposure to these chemicals. The aim of this study was to look at the pesticides applied in fruit, vegetable, and beef cattle productions in Mendoza (Argentina), to identify those that were simultaneously used by the three production systems. Local individuals (n = 160), involved in these productions, were interviewed. Glyphosate was the a.i. most often used by fruit-vegetable producers, and ivermectin by beef cattle producers. Chlorpyrifos (CPF) and cypermethrin (CYP) were the only a.i. used by the three production systems. The survey revealed that CPF, CYP, alpha CYP, and CPF+CYP were used by 22, 16, 4, and 20% of the fruit and vegetable producers, respectively. Regarding beef cattle, CYP was used by 90% of producers, CYP + CPF formulation by 8%, and alpha CYP by 2%. The second approach of this study was to search the occurrence of CYP and CPF residues in food commodities analyzed under the National Plan for Residue Control (2012–2015). CYP residues found above the LOD were reported in 4.0% and CPF in 13.4% of the vegetable samples tested, as well as in 1.2 and 28.8%, respectively, of the fruit samples tested. Regarding beef cattle, CYP residues were reported in 2.3% and organophosphates (as a general pesticide class) in 13.5% of samples tested. In conclusion, consumers may be exposed simultaneously to CPF and CYP, from fruits, vegetables, and beef intake. Accordingly, the policy for pesticide residues in food and human risk assessment should account for the combined exposure to CPF and CYP. Moreover, appropriate toxicological studies of this mixture (including genotoxicity) are warrante
LGBTQ parenting post heterosexual relationship dissolution
The chapter examines parenting among sexual and gender minorities post heterosexual relationship dissolution (PHRD). Reviewing the literature around intersecting identities of LGBTQ parents, we consider how religion, race, and socioeconomic status are associated with routes into and out of heterosexual relationships and variation in the lived experience of sexual and gender identity minorities, in particular how LGBTQ parents PHRD feel about being out. Further consideration is given to examining how family relationships change and develop as parental sexual and/or gender identity changes. We also explore the impact of PHRD identity and parenthood on new partnerships and stepfamily experiences. The chapter addresses the reciprocal relationship between research on LGBTQ parenting and policy and legal influences that impact upon the experience of LGBTQ parenting PHRD when custody and access are disputed. Finally, the chapter includes future research directions and implications for practice in an area that has been revitalized in recent years
Technical-tactical analysis of youth Olympic taekwondo combat
The purpose of this study was to define the technical and tactical profiles of official youth taekwondo competitions played under the most recent rules of the International Taekwondo Federation. Tactical actions (i.e., attack, defense, and block), technical executions (from 1- to 4-point scores), kicking legs (i.e., front/rear and right/left), and overall technical effectiveness were investigated in relation to match outcome of semifinal and final competitions (n = 50) of youth (aged 13-14 years) black belt athletes during the Italian Taekwondo Cadet Championship. Differences (p < 0.001) were found among all action typologies (Attack: 50.9 ± 2.2%; Defense: 27.7 ± 1.5%; Block: 21.3 ± 1.6%), with winners showing fewer (p = 0.005) offensive actions and more (p = 0.001) defensive actions with respect to non-winners. Independently from match outcome, technical exchanges showed differences (p < 0.001) for technical executions. Winners resulted more efficient (p < 0.001) for both technical and tactical variables. In general, these findings showed that Cadets tend to adopt an offensive strategy. In considering that the adoption of the new electronic system requires athletes to execute correct technical actions to have a score assigned, coaches should emphasize the effectiveness of scoring techniques and help athletes to effectively improve their defense and counterattack capabilities
A new method to select rotor position sensor resolution in variable speed drives
The aim of this research is to present a new method for the selection of position sensor resolution in variable speed drives. The proposed approach links the minimum sensor resolution Nds to the required drive performances, expressed in terms of desired quantization speed harmonics attenuation and speed control loop bandwidth, both defined at the minimum requested operating speed. Although the selection of rotor position sensor resolution is presented for a vector tracking observer, this approach is general and can be used in conjunction with the operating point model of any speed estimation algorithm. Simulations and experimental results validate the effectiveness of the proposed method
Selection of rotor position sensor resolution for variable frequency drives utilizing fixed-position-based speed estimation
The aim of this paper is to provide a simple and effective tool to determine the minimum resolution required from a rotor position sensor for variable frequency drives using fixed-position-based speed estimation. It is shown that it is possible to determine the minimum resolution based on the required bandwidth and phase margin of the speed control at the lowest operating speed. The effectiveness of the proposed method is then verified by means of dynamic stiffness analysis, performed in simulations and experimentally on a 3.6kW permanent magnet motor drive
Indoor and outdoor education: The role of body representations on sport practice
Background: Body representation is a complex process determined by the interaction of information coming from many different stimuli inside and outside the body and is a fundamental construct that reflects our knowledge of self. However, the way in which we perceive our bodies and how the body is represented in the brain during development, particularly during outdoor or indoor physical activity, is not yet fully understood. The aim of this study was to examine the development of different body representations (i.e., body semantics, body structural representation, and body schema) in school-aged children who practice indoor or outdoor sports. The role of motor coordination was considered as well. Methods:One hundred twelve school aged-children (age range: 8-10 years) completed a computerized battery that included three tasks, the Hand Laterality Task (HLT), Object-Body-Part Association (OBP), and Frontal Body Evocation task(FBE)involving body representation processing as well as control tasks. These control tasks included the Object Laterality Task (OLT), the Christmas Tree Task (CTT), and the Object-Room Association Task (ORT).Theparticipants also performed a foot-tapping performance test (FTap). Results: The effect of indoor or outdoor physical activity on body representations and the associations between age,performance on body representation tasks, and performance on the FTap were all analyzed.When we compared the performance of the two groups on the different body representation and control tasks, we found significant differences only on the FBE, whereas the outdoor physical activity group showed a better performance than the indoor physical activity group. Among the outdoor athletes, significant correlations were foundbetween age and errors made in the FTap, but there were no significant associations between the FTap and the body representation measures. Instead, in the indoor physical activity group, we found significant correlations between the FTap measures and body representation tasks. Discussion: Participants engaging in outdoor physical activities (i.e., soccer, baseball, tennis, cross-country) had better performance on the task assessing the body structural representation (FBE), suggesting that in addition to a significant improvement of physical and mental wellbeing, outdoor physical activity significantly improves the visuo-spatial body map during development.Conclusion:In conclusion,for the first time, we have demonstrated that in school-aged children outdoor physical activity as compared toindoor physical activity improves the structural body representation. These findings are discussed for a better understanding of body representation development and physical activity in indoor and outdoor environments.Also, considering the possible impact of body processing on cognition, this data is discussed in the light of the role of the practice of sportin the educational context
Salivary Alpha-Amylase, Salivary Cortisol, and Anxiety during a Youth Taekwondo Championship
The aim of this study was to assess the stress-related responses and the coach's capability to match perceived efforts of youth athletes during a taekwondo championship.Using a cross-sectional study design, salivary cortisol (sC) and alpha-amylase (sAA) were measured in 6 males and 3 females young (11.0 ± 0.9 years) athletes at awakening, 5 minutes before, and 1 minute and 30 minutes after official combats. State anxiety was recorded 60 minutes before the first competition, whereas coach's and athletes' ratings of perceived exertion (RPE) were obtained at the end of the combats. Time-matched (awakening and pre-competition) salivary samples and trait anxiety were collected 7-day postcompetition during a resting day.No effect for match outcome emerged. No difference emerged between athletes and coach RPEs. Higher (P = .03) state anxiety (41.6 ± 10.9 points) was shown than trait anxiety (34.8 ± 7.1 points). Time-matched sAA were similar. Peak sAA observed at the end of the combat (114.2 ± 108.1 U/mL) was higher (P < .01) than the other samples (range: 20.6-48.1 U/mL), whereas sC increased (P < .05) from awakening (8.0 ± 1.5 nmol/L), with peak levels observed at 30 minutes into the recovery phase (19.3 ± 4.3 nmol/L). Furthermore, pre-competition sC (16.5 ± 4.5 nmol/L) values were higher (P < .01) with respect to time-matched samples during the resting day (4.6 ± 1.0 nmol/L). The 3 athletes engaged in consecutive matches showed a tendency toward increasing sAA and sC.Taekwondo combats pose a high stress on young athletes, eliciting a fast reactivity of the sympathetic-adreno-medullary system relative to the hypothalamic-pituitary-adrenocortical system. Understanding the athlete's efforts during combats, coaches are recommended to apply effective recovery strategies between matches
Identification and recovery of local Vitis vinifera L. cultivars collected in ancient vineyards in different locations of Argentina
International audienceBackground and Aims These last years, minor cultivars have gained attention as they provide an opportunity to offer original products in a global market and to combat global warming. Recent evidence brought to light the existing diversity within the group of autochthonous cultivars from Argentina and other South American countries, commonly known as criollas. The objective was to prospect, rescue and identify grapevine phenotypes recovered in ancient vineyards as putative criollas, in the western provinces of Argentina. Methods and Results We collected 60 samples in 11 locations. Their identity and pedigree were analysed through nuclear simple sequence repeat (nSSR) markers. The 60 samples were grouped in 45 different genotypes, 19 of them corresponding to previously registered cultivars, while 26 were new genotypes, with no correspondence in international databases. The majority (18) of the 26 new genotypes were related with the criollas group while other genotypes presented a totally different genetic profile and its origin remains to be elucidated. Conclusions The diversity within the South American cultivars is higher than previously thought. Ancient vineyards, located in isolated valleys, are reservoirs of minor cultivars, and growers have played a key role in maintaining and conserving them. Significance of the Study This genetic diversity constitutes a valuable tool to explore alternatives for diversification and adaptation to climate change