1,934 research outputs found
Study of Cyclization of Diphenylacetals Derived from L-rhamnose and L-fucose: A Theoretical Approach
This work aimed to study the configuration of two mono-tosyl-diphenylacetals, highly flexible molecules derived from L-ramnose and L-fucose, by means of the Monte Carlo conformational search method. The energy of the conformers established by this method and calculated by using the molecular mechanics force field (MMFF) permitted to establish a first conformational space. The geometry of the conformers was optimized by using the semi-empirical AM1 and the density functional B3LYP/DGDZVP methods. We were able to explain the different final products recovered from the reaction of the diphenylacetals derived from L-rhamnose and L-fucose with tosyl chloride, in a pyridine solution. On the other hand, obtaining cyclical compounds by intramolecular cyclization could be an attractive pathway for the synthesis of furanosides.Keywords: Molecular modelling, conformational analysis, Monte Carlo conformational search method, L-rhamnose, L-fucose, B3LYP, DGDZVP, diphenylthioaceta
Editorial: Eliciting plant defense responses: From basic to applied science for sustainable agriculture
Plants constantly face a diversity of pathogens and insects that affect food production. Synthetic agrochemicals are often use to overcome these challenges. However, current demands for stringent worldwide regulatory policies led to the development of sustainable agriculture strategies, including naturally-derived molecules that elicit plant defense responses (Scariotto et al., 2021). The commercial use of these molecules is still limited, mostly due to poor knowledge on the molecular mechanisms producing their effects on plant metabolism. In recent decades, efforts have been directed toward understanding how individual molecules, such as immune receptors or microbial effectors, enable plants to perceive and respond to pathogens, insects, and other stresses. Furthermore, recent research on plant immunity has revealed high levels of complexity, including regulation mediated by micro-peptides and miRNA. Such knowledge opens the opportunity to link basic and applied science to facilitate using natural elicitors as a sustainable option for crop protection
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Influence of Wheat Straw Pelletizing and Inclusion Rate in Dry Rolled or Steam-flaked Corn-based Finishing Diets on Characteristics of Digestion for Feedlot Cattle.
Eight Holstein steers (216±48 kg body weight) fitted with ruminal and duodenal cannulas were used to evaluate effects of wheat straw processing (ground vs pelleted) at two straw inclusion rates (7% and 14%; dry matter basis) in dry rolled or steam-flaked corn-based finishing diets on characteristics of digestion. The experimental design was a split plot consisting of two simultaneous 4×4 Latin squares. Increasing straw level reduced ruminal (p<0.01) and total tract (p = 0.03) organic matter (OM) digestion. As expected, increasing wheat straw level from 7% to 14% decreased (p<0.05) ruminal and total tract digestion of OM. Digestion of neutral detergent fiber (NDF) and starch, per se, were not affected (p>0.10) by wheat straw level. Likewise, straw level did not influence ruminal acetate and propionate molar proportions or estimated methane production (p>0.10). Pelleting straw did not affect (p≥0.48) ruminal digestion of OM, NDF, and starch, or microbial efficiency. Ruminal feed N digestion was greater (7.4%; p = 0.02) for ground than for pelleted wheat straw diets. Although ruminal starch digestion was not affected by straw processing, post-ruminal (p<0.01), and total-tract starch (p = 0.05) digestion were greater for ground than for pelleted wheat straw diets, resulting in a tendency for increased post-ruminal (p = 0.06) and total tract (p = 0.07) OM digestion. Pelleting wheat straw decreased (p<0.01) ruminal pH, although ruminal volatile fatty acids (VFA) concentration and estimated methane were not affected (p≥0.27). Ruminal digestion of OM and starch, and post-ruminal and total tract digestion of OM, starch and N were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal NDF digestion was greater (p = 0.02) for dry rolled than for steam-flaked corn, although total tract NDF digestion was unaffected (p = 0.94). Ruminal microbial efficiency and ruminal degradation of feed N were not affected (p>0.14) by corn processing. However, microbial N flow to the small intestine and ruminal N efficiency (non-ammonia N flow to the small intestine/N intake) were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal pH and total VFA concentration were not affected (p≥ 0.16) by corn processing method. Compared with dry rolled corn, steam-flaked corn-based diets resulted in decreased acetate:propionate molar ratio (p = 0.02). It is concluded that at 7% or 14% straw inclusion rate, changes in physical characteristics of wheat straw brought about by pelleting negatively impact OM digestion of both steam-flaked and dry-rolled corn-based finishing diets. This effect is due to decreased post-ruminal starch digestion. Replacement of ground straw with pelleted straw also may decrease ruminal pH
Bibliometric Analysis of Psychomotricity Research Trends: The Current Role of Childhood
Psychomotricity is a wide broad term, which encompasses different bodily action approaches to support children and adolescents to achieve their highest potential. A search on the Web of Science (WoS) Core Collection database was performed on this topic, using traditional bibliometric laws. Finally, 118 publications (112 articles and 6 reviews) documents were found. Annual publications presented an exponentially growing trend (R2 = 84.7%). Spain was the most productive country/region worldwide. Paola Magioncalda, Matteo Martino y Víctor Arufe Giraldez were highlighted as the most prolific co-authors. “Retos Nuevas Tendencias en Educación Física, Deporte y Recreación” was the most productive journal and the “International Journal of Environmental Research and Public Health”, was the second most productive; the third in the list was the most productive in the JCR ranking. Thus, research on psychomotricity is experiencing exponential growth, causing this topic to generate great interest among researchers, publishers and journals. The most cited paper was “Neurocognitive Effects of Alcohol Hangover”. The author keywords that were first raised together with psychomotricity were related to rehabilitation and psychomotor development, while the current trend was focused on physical activity and early childhood education
The white dwarf in dwarf nova SDSS J080434.20+510349.2: Entering the instability strip?
SDSS J080434.20+510349.2 is the WZ type binary that displayed rare outburst
in 2006 (Pavlenko et al., 2007). During the long-lasting tail of the late stage
of the outburst binary shown the two-humped or four-humped profile of the
orbital light modulation. The amplitude of orbital light curve decreased while
the mean brightness decreased, more over that occurred 10 times faster
during the fast outburst decline in respect to the late quiet state of slow
outburst fading. There were no white dwarf pulsations detected neither 1 - 1.5
months prior to the outburst nor in 1.5 - 2 months after the 2006 outburst in
this system. However the strong non-radial pulsations with period 12.6 minutes
and mean amplitude of 0.05^m were first detected in V band with 2.6-m Shajn
mirror telescope of the Crimean astrophysical observatory in ~ 8 months after
the outburst. The evolution of pulsations over two years in 2006 - 2008 is
considered. It is supposed that pulsations first appeared when the cooling
white dwarf (after the outburst) entered the instability strip although the
possibility of temporary lack of pulsations at some occasions also could not be
excluded.Comment: Submitted to Proceedings of 16th European White Dwarf Workshop
(EUROWD08
Evaluación de los niveles de actividad física y salud mental en universitarios durante la pandemia SARS-COV2
The main aim of this research is to evaluate the levels of physical activity (PA) and mental health in university students during the COVID-19 coronavirus (SARS-COV2) pandemic. The DASS-21 scale, the Global Physical Activity Questionnaire (GPAQ) and the SF-36 Health Questionnaire were applied to 63 university students from the State of Veracruz, Mexico, aged 18 to 24 years. in the statistical software SPSS v.25, a result that 76.2% of the population was found to be physically active, the correlation coefficients between physical activity and anxiety (r=-.41) physical activity and stress (r=-.42) showed correlations moderate to intense respectively. Concluding that physical activity during the pandemic was shown to significantly reduce problems related to mental health.El objetivo principal de esta investigación, es evaluar los niveles de actividad física (AF) y salud mental en universitarios durante la pandemia del coronavirus COVID-19 (SARS-COV2). Se aplicó la escala DASS-21, el Cuestionario Mundial sobre Actividad Física (GPAQ) y el Cuestionario de Salud SF-36 a de 63 jóvenes universitarios originarios del Estado de Veracruz, México, de 18 a 24 años, el tratamiento de datos se realizó en el software estadístico SPSS v.25, resultado que 76.2% de la población se encontró físicamente activa, los coeficientes de correlación entre actividad física y ansiedad (r=-.41) actividad física y estrés (r=-.42) mostraron correlaciones moderadas a intensas respectivamente. Concluyendo que la actividad física durante la pandemia, demostró reducir significativamente los problemas relacionados a la salud mental
Association of parenting practices to encourage or discourage physical activity with Hispanic preschool children's objectively measured physical activity
Oral Session - Determinants of physical activity in children and adolescents: no. O.002Conference Theme: Promoting Healthy Eating and Activity WorldwidePURPOSE: Assess the association of parenting practices (PP) to encourage or discourage physical activity (PA) with Hispanic 3-5 year old children’s objectively measured PA METHOD: Cross-sectional study of Hispanic parent-child dyads (n= 84) who reported their demographics and frequency of using PP that encourage (structure/encouragement) or discourage (promote inactive transport, promote screen time, psychological control, and safety concerns) child PA using verified scales. Children wore Actigraph GT3X accelerometers recording 15 second epochs for 7 days. Allowing for re-wears …postprin
Psychometrics of new scales of parenting practices to encourage or discourage Hispanic preschool children's physical activity
Conference Theme: Promoting Healthy Eating and activity worldwidePoster - Personal and environmental determinants of physical activity in children and adolescents: abstract P077PURPOSE: Develop and assess the psychometrics of a new instrument for parenting practices (PP) that encourage or discourage physical activity (PA) in Hispanic preschool children. METHOD: Cross--‐sectional study of 240 Hispanic parents who reported their demographics and frequency of using PP that encourage (structure and encouragement) or discourage (promoting inactivity, psychological control, safety …postprin
Effects of a school-based intervention on active commuting to school and health-related fitness
Background: Active commuting to school has declined over time, and interventions are needed to reverse this
trend. The main objective was to investigate the effects of a school-based intervention on active commuting to
school and health-related fitness in school-age children of Southern Spain.
Methods: A total of 494 children aged 8 to 11 years were invited to participate in the study. The schools were
non-randomly allocated (i.e., school level allocation) into the experimental group (EG) or the control group (CG).
The EG received an intervention program for 6 months (a monthly activity) focused on increasing the level of active
commuting to school and mainly targeting children’s perceptions and attitudes. Active commuting to school and
health-related fitness (i.e., cardiorespiratory fitness, muscular fitness and speed-agility), were measured at baseline
and at the end of the intervention. Children with valid data on commuting to school at baseline and follow-up, sex,
age and distance from home to school were included in the final analysis (n = 251). Data was analyzed through a
factorial ANOVA and the Bonferroni post-hoc test.
Results: At follow up, the EG had higher rates of cycling to school than CG for boys only (p = 0.04), but not for
walking to school for boys or girls. The EG avoided increases in the rates of passive commuting at follow up, which
increased in the CG among girls for car (MD = 1.77; SE = 0.714; p = 0.010) and bus (MD = 1.77; SE = 0.714; p = 0.010)
modes. Moreover, we observed significant interactions and main effects between independent variables (study group,
sex and assessment time point) on health-related fitness (p < 0.05) over the 6-month period between groups, with
higher values in the control group (mainly in boys).
Conclusion: A school-based intervention focused on increasing active commuting to school was associated with
increases in rates of cycling to school among boys, but not for walking to school or health-related fitness. However, the
school-based intervention avoided increases in rates of passive commuting in the experimental group, which were
significantly increased in girls of the control group
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