Objective: The purpose of this study was to identify the influence of readiness of change for physical activity (PA), sociodemographic factors, lifestyle and physical activity status (PAS) on perceived barriers among ...Objective: The purpose of this study was to identify the influence of readiness of change for physical activity (PA), sociodemographic factors, lifestyle and physical activity status (PAS) on perceived barriers among Spanish university students. Participants: Seven hundred and seventy two (n = 772) men and women ages 17-39 at a north-west regional university in Spain participated in the study. Methods: The International Physical Activity Questionnaire, the States of Change for Physical Activity Behaviour Questionnaire and the Self-perceived Barriers for Physical Activity Questionnaire were used. Description, correlation and multiple regression analyses were completed. Results: Participants self-perceived low average-score barriers (2.6 ± 1.4 over 10.0). The 3-higher scores barriers corresponded to “too much work”;“lack of time for exercise” and “laziness”. Gender, PAS and self-perceived health were shown to be associated with perceived barriers. Conclusions: University institutions should consider those factors that predict barriers to PA to develop effective intervention programs.展开更多
Classical chaotic behavior in diatomic molecules is studied when chaos is driven by a circularly polarized resonant electric field and expanding up to fourth order of approximation the Morse’s potential and angular m...Classical chaotic behavior in diatomic molecules is studied when chaos is driven by a circularly polarized resonant electric field and expanding up to fourth order of approximation the Morse’s potential and angular momentum of the system. On this double resonant system, we find a weak and a strong stationary (or critical) points where the chaotic characteristics are different with respect to the initial conditions of the system. Chaotic behavior around the weak critical point appears at much weaker intensity on the electric field than the electric field needed for the chaotic behavior around the strong critical point. This classical chaotic behavior is determined through Lyapunov exponent, separation of two nearby trajectories, and Fourier transformation of the time evolution of the system. The threshold of the amplitude of the electric field for appearing the chaotic behavior near each critical point is different and is found for several molecules.展开更多
A classical action which describes the motion of a system of small-point massive charged particles including the existence of the electromagnetic and gravitational self-forces, Maxwell equations and Einstein field equ...A classical action which describes the motion of a system of small-point massive charged particles including the existence of the electromagnetic and gravitational self-forces, Maxwell equations and Einstein field equations is presented. The action possesses the particularity of being a functional of the variables zi (τi), the trajectory of the i-particle, Aα (x), the electromagnetic 4-potential, and gαβ(x), the metric tensor. It is also considered that the metric tensor gαβ (x) and the potential Aα (x) are not functions of the trajectory of each particle when the variations with respect to the trajectories of the particles are done. That is, the action is complete. The electromagnetic and the gravitational self-forces are analyzed.展开更多
Background:There is a growing body of experimental evidence examining the effects of plyometric jump training(PJT)on physical fitness attributes in basketball players;however,this evidence has not yet been comprehensi...Background:There is a growing body of experimental evidence examining the effects of plyometric jump training(PJT)on physical fitness attributes in basketball players;however,this evidence has not yet been comprehensively and systematically aggregated.Therefore,our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players,in comparison to a control condition.Methods:A systematic literature search was conducted in the databases PubMed,Web of Science,and Scopus,up to July 2020.Peer-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes(muscle power,i.e.,jumping performance,linear sprint speed,change-of-direction speed,balance,and muscle strength)in basketball players,with no restrictions on their playing level,sex,or age.Hedge’s g effect sizes(ES)were calculated for physical fitness variables.Using a random-effects model,potential sources of heterogeneity were selected,including subgroup analyses(age,sex,body mass,and height)and single training factor analysis(program duration,training frequency,and total number of training sessions).Computation of metaregression was also performed.Results:Thirty-two studies were included,involving 818 total basketball players.Significant(p<0.05)small-to-large effects of PJT were evident on vertical jump power(ES=0.45),countermovement jump height with(ES=1.24)and without arm swing(ES=0.88),squat jump height(ES=0.80),drop jump height(ES=0.53),horizontal jump distance(ES=0.65),linear sprint time across distances≤10 m(ES=1.67)and>10 m(ES=0.92),change-of-direction performance time across distances≤40 m(ES=1.15)and>40 m(ES=1.02),dynamic(ES=1.16)and static balance(ES=1.48),and maximal strength(ES=0.57).The meta-regression revealed that training duration,training frequency,and total number of sessions completed did not predict the effects of PJT on physical fitness attributes.Subgroup analysis indicated greater improvements in older compared to younger players in horizontal jump distance(>17.15 years,ES=2.11;≤17.15 years,ES=0.10;p<0.001),linear sprint time>10 m(>16.3 years,ES=1.83;≤16.3 years,ES=0.36;p=0.010),and change-of-direction performance time≤40 m(>16.3 years,ES=1.65;≤16.3 years,ES=0.75;p=0.005).Greater increases in horizontal jump distance were apparent with>2 compared with≤2 weekly PJT sessions(ES=2.12 and ES=0.39,respectively;p<0.001).Conclusion:Data from 32 studies(28 of which demonstrate moderate-to-high methodological quality)indicate PJT improves muscle power,linear sprint speed,change-of-direction speed,balance,and muscle strength in basketball players independent of sex,age,or PJT program variables.However,the beneficial effects of PJT as measured by horizontal jump distance,linear sprint time>10 m,and change-of-direction performance time≤40 m,appear to be more evident among older basketball players.展开更多
We review the semiclassical method proposed in [1], a generalization of this method for n-dimensional system is presented. Using the cited method, we present an analytical method of obtain the semiclassical Husimi Fun...We review the semiclassical method proposed in [1], a generalization of this method for n-dimensional system is presented. Using the cited method, we present an analytical method of obtain the semiclassical Husimi Function. The validity of the method is tested using Harmonic Oscillator, Morse Potential and Dikie’s Model as example, we found a good accuracy in the classical limit.展开更多
The classical limit of the quantum mechanical Kepler problem is derived by using a simple mathematical procedure recently proposed. The method is based both on Bohr’s correspondence principle and the local averages o...The classical limit of the quantum mechanical Kepler problem is derived by using a simple mathematical procedure recently proposed. The method is based both on Bohr’s correspondence principle and the local averages of the quantum probability distribution. We illustrate in a clear fashion the difference between Planck’s limit and Bohr’s correspondence principle. We discuss the confinement effect in macroscopic systems.展开更多
Purpose: This study aims to compare adolescents' cardiometabolic risk score through an integrative classification of physical activity(PA),which involves the combination of moderate-to-vigorous physical activity(M...Purpose: This study aims to compare adolescents' cardiometabolic risk score through an integrative classification of physical activity(PA),which involves the combination of moderate-to-vigorous physical activity(MVPA) and sedentary behavior(SB).Methods: A cross-sectional study derived from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study database(2006-2008) was conducted in adolescents(n = 548; boys, 47.3%; 14.7 ± 1.2 years) from 10 European cities. MVPA and SB were objectively measured using accelerometry. Adolescents were divided into 4 categories according to MVPA(meeting or not meeting the international recommendations) and the median of SB time(above or below sex-and age-specific median) as follows: High-SB & Inactive, Low-SB & Inactive,High-SB & Active, and Low-SB & Active. A clustered cardiometabolic risk score was computed using the homeostatic model assessment, systolic blood pressure, triglycerides, total cholesterol/high-density lipoprotein cholesterol, sum 4 skinfolds, and cardiorespiratory fitness(CRF).Analyses of covariance were performed to discern differences on cardiometabolic risk scores among PA categories and each health component.Results: The cardiometabolic risk score was lower in adolescents meeting the MVPA recommendation and with less time spent in SB in comparison to the high-SB & Inactive group(p < 0.05). However, no difference in cardiometabolic risk score was established between High-SB or Low-SB groups in inactive adolescents. It is important to note that CRF was the only variable that showed a significant modification(higher)when children were compared from the category of physically inactive with "active" but not from high-to low-SB.Conclusion: Being physically active is the most significant and protective outcome in adolescents to reduce cardiometabolic risk. Lower SB does not exhibit a significant and extra beneficial difference.展开更多
In this paper, the Ground Penetrating Radar (GPR) method was used to characterize concrete tubes and steel/plastic tanks buried in IAG/USP test site. The microwave tomography was used to improve the GPR images, aiming...In this paper, the Ground Penetrating Radar (GPR) method was used to characterize concrete tubes and steel/plastic tanks buried in IAG/USP test site. The microwave tomography was used to improve the GPR images, aiming to retrieve the geometry of the targets. The numerical modeling studies also were done in order to predict the GPR results of the buried targets and to give more reliability to the results interpretation. The targets were installed in the first shallow geophysical test site of the Brazil located at Institute of Astronomy, Geophysics, and Atmospheric Science (IAG) of the University of S?o Paulo (USP). GPR profiles of 200 MHz (shielded bistatic antennas) were acquired along three lines containing concrete tubes and steel/plastic tanks buried in subsoil. The concrete tubes show a hyperbolic reflector for the top, and the vertical tube also presented a reflection on its bottom. The horizontal steel tanks were characterized by a strong GPR reflection on their top. The empty plastic tank shows a strong reflector for the top with normal polarity. On the other hand, the plastic tank filled with water shows a weaker reflector for its top characterized by the inverted polarity of GPR signal when compared with empty plastic tank. The plastic tank filled with water also went characterized by the strong reflection to its bottom, being a good indicative to interpret GPR data on target in subsoil with some types of fluid inside of tank. The results of polarity difference for the top of tank can be used as guide pattern to identify buried tank empty or filled with water. The application of microwave tomography to the GPR data permitted to determine the position and get a good identification of the edges of the targets studied. The numeric modeling presented a good accordance with real data reducing the ambiguities in interpretation of results. These results can be used as a reference, and they can be extrapolated for areas where there is no subsurface information.展开更多
The model profession uses the appearance for the representation of products and brands via events. For some individuals that are included in this medium, plus a laboral activity, modeling becomes a lifestyle, the sear...The model profession uses the appearance for the representation of products and brands via events. For some individuals that are included in this medium, plus a laboral activity, modeling becomes a lifestyle, the search for the status and work opportunities turn a dream for a thousands of children and teenagers because the profession has particulars experiences. To win this, many girls change physical and eating behaviors which are harmful to health. The objective of this study was to analyze the health-related physical fitness in female models comparing them with non-models. The study was conducted at the Caxias do Sul, Rio Grande do Sul, Brazil. Participated of the study female runway and commercial models bokered in Cast One Models, with age between 15 - 25 years old. The non-models were students from public and private schools or university students. The health-related physical fitness, the physical activity levels and dietary intake were assessed of all participants. The data were described as mean and standard deviation. For comparison between models and non-models was used t independent test for variables normally distributed and U Mann-Whitney test for not normally distributed variables, adopting a level of significance (α) of 0.05. It was found difference in total energy between model group and non-model (GM: 1509.78 kcal, NM: 2292.51 Kcal;p = 0.014). There were no differences between groups in the others variables analyzed (p > 0.05). In conclusion, the profession model seems not interfere in variables that make up the health-related physical fitness.展开更多
This study aimed to characterize the physical-chemical and biological properties of pectin(PC)/chia seed mucilage(CM)membranes.PC/CM[100/0(control),80/20%,60/40%,and 40/60%w/w]membranes were prepared using the casting...This study aimed to characterize the physical-chemical and biological properties of pectin(PC)/chia seed mucilage(CM)membranes.PC/CM[100/0(control),80/20%,60/40%,and 40/60%w/w]membranes were prepared using the casting method.The membranes(PC/CM)were thin,yellow,lightly opaque(≈10%)and capable of blocking light UVB(between 66 at 52%).SEM analysis showed the presence of aggregates in the shape of a sphere(≈13μm)and ovoid(≈25μm).The proportion of 80/20 showed an increase in tensile strength(29%)and elastic modulus(19%)when compared to the control.FTIR analysis exhibited intermolecular interactions between PCPC,PC-CM,and CM-CM in the membranes.The thermal analysis(600°C)showed a slight improvement in the percentage of residual mass-loss of 3.31%(80/20)that control.The 40/60 membrane showed the lowest percentage of hemolysis(2.94%)but limited human albumin adsorption capacity.These results suggested that the blend PC/CM may be considered as a biomaterial for medical applications.展开更多
Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transform...Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.展开更多
This work presents the climatology of the microphysics and the dynamics of weather systems in two coastal areas of São Paulo and the Espírito States at high spatial-temporal resolution as measured by two...This work presents the climatology of the microphysics and the dynamics of weather systems in two coastal areas of São Paulo and the Espírito States at high spatial-temporal resolution as measured by two dual Doppler weather radars during the summer and early fall of 2015. Averages and respective standard deviations of polarimetric variables, namely, reflectivity (Z), differential reflectivity (Z<sub>DR</sub>), differential phase (ϕ<sub>DP</sub>), specific differential phase (K<sub>DP</sub>), copolar correlation coefficient (ρ<sub>oHV</sub>), radial velocity (V<sub>r</sub>), and the spectral width (W) were obtained within a 240-km range on plan position indicator (PPI), constant altitude plan position indicator (CAPPI) and vertical cross-sections to analyze overall horizontal and vertical precipitation microphysics and mesoscale circulation of prevailing weather systems, and their peculiarities over coastal and oceanic, and urban and rural areas. Overall, raindrops tend to be larger over the Metropolitan area of São Paulo from the surface to up to 6 km altitude indicating more vigorous updrafts caused by the heat island effect and the local sea breeze. The vertical microphysical structure is remarkably distinct over the Metropolitan Area of São Paulo (MASP) where thunderstorms can reach 20-km altitude in summertime under sea breeze and heat island effects. On the other hand, there is a dominancy of smaller drop sizes though larger ones observed close to the surface by the coast of Espírito Santo and at the land-ocean interface influenced by the local low-level jet and oceanic-type CCN. Convective cells tend to be smaller associated with Easterlies and more organized with Westerlies. The results indicate distinct features on hydrometeor types and circulation characteristics under these different surface and boundary-layer conditions in close agreement with previous results in the literature.展开更多
文摘Objective: The purpose of this study was to identify the influence of readiness of change for physical activity (PA), sociodemographic factors, lifestyle and physical activity status (PAS) on perceived barriers among Spanish university students. Participants: Seven hundred and seventy two (n = 772) men and women ages 17-39 at a north-west regional university in Spain participated in the study. Methods: The International Physical Activity Questionnaire, the States of Change for Physical Activity Behaviour Questionnaire and the Self-perceived Barriers for Physical Activity Questionnaire were used. Description, correlation and multiple regression analyses were completed. Results: Participants self-perceived low average-score barriers (2.6 ± 1.4 over 10.0). The 3-higher scores barriers corresponded to “too much work”;“lack of time for exercise” and “laziness”. Gender, PAS and self-perceived health were shown to be associated with perceived barriers. Conclusions: University institutions should consider those factors that predict barriers to PA to develop effective intervention programs.
文摘Classical chaotic behavior in diatomic molecules is studied when chaos is driven by a circularly polarized resonant electric field and expanding up to fourth order of approximation the Morse’s potential and angular momentum of the system. On this double resonant system, we find a weak and a strong stationary (or critical) points where the chaotic characteristics are different with respect to the initial conditions of the system. Chaotic behavior around the weak critical point appears at much weaker intensity on the electric field than the electric field needed for the chaotic behavior around the strong critical point. This classical chaotic behavior is determined through Lyapunov exponent, separation of two nearby trajectories, and Fourier transformation of the time evolution of the system. The threshold of the amplitude of the electric field for appearing the chaotic behavior near each critical point is different and is found for several molecules.
文摘A classical action which describes the motion of a system of small-point massive charged particles including the existence of the electromagnetic and gravitational self-forces, Maxwell equations and Einstein field equations is presented. The action possesses the particularity of being a functional of the variables zi (τi), the trajectory of the i-particle, Aα (x), the electromagnetic 4-potential, and gαβ(x), the metric tensor. It is also considered that the metric tensor gαβ (x) and the potential Aα (x) are not functions of the trajectory of each particle when the variations with respect to the trajectories of the particles are done. That is, the action is complete. The electromagnetic and the gravitational self-forces are analyzed.
文摘Background:There is a growing body of experimental evidence examining the effects of plyometric jump training(PJT)on physical fitness attributes in basketball players;however,this evidence has not yet been comprehensively and systematically aggregated.Therefore,our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players,in comparison to a control condition.Methods:A systematic literature search was conducted in the databases PubMed,Web of Science,and Scopus,up to July 2020.Peer-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes(muscle power,i.e.,jumping performance,linear sprint speed,change-of-direction speed,balance,and muscle strength)in basketball players,with no restrictions on their playing level,sex,or age.Hedge’s g effect sizes(ES)were calculated for physical fitness variables.Using a random-effects model,potential sources of heterogeneity were selected,including subgroup analyses(age,sex,body mass,and height)and single training factor analysis(program duration,training frequency,and total number of training sessions).Computation of metaregression was also performed.Results:Thirty-two studies were included,involving 818 total basketball players.Significant(p<0.05)small-to-large effects of PJT were evident on vertical jump power(ES=0.45),countermovement jump height with(ES=1.24)and without arm swing(ES=0.88),squat jump height(ES=0.80),drop jump height(ES=0.53),horizontal jump distance(ES=0.65),linear sprint time across distances≤10 m(ES=1.67)and>10 m(ES=0.92),change-of-direction performance time across distances≤40 m(ES=1.15)and>40 m(ES=1.02),dynamic(ES=1.16)and static balance(ES=1.48),and maximal strength(ES=0.57).The meta-regression revealed that training duration,training frequency,and total number of sessions completed did not predict the effects of PJT on physical fitness attributes.Subgroup analysis indicated greater improvements in older compared to younger players in horizontal jump distance(>17.15 years,ES=2.11;≤17.15 years,ES=0.10;p<0.001),linear sprint time>10 m(>16.3 years,ES=1.83;≤16.3 years,ES=0.36;p=0.010),and change-of-direction performance time≤40 m(>16.3 years,ES=1.65;≤16.3 years,ES=0.75;p=0.005).Greater increases in horizontal jump distance were apparent with>2 compared with≤2 weekly PJT sessions(ES=2.12 and ES=0.39,respectively;p<0.001).Conclusion:Data from 32 studies(28 of which demonstrate moderate-to-high methodological quality)indicate PJT improves muscle power,linear sprint speed,change-of-direction speed,balance,and muscle strength in basketball players independent of sex,age,or PJT program variables.However,the beneficial effects of PJT as measured by horizontal jump distance,linear sprint time>10 m,and change-of-direction performance time≤40 m,appear to be more evident among older basketball players.
文摘We review the semiclassical method proposed in [1], a generalization of this method for n-dimensional system is presented. Using the cited method, we present an analytical method of obtain the semiclassical Husimi Function. The validity of the method is tested using Harmonic Oscillator, Morse Potential and Dikie’s Model as example, we found a good accuracy in the classical limit.
文摘The classical limit of the quantum mechanical Kepler problem is derived by using a simple mathematical procedure recently proposed. The method is based both on Bohr’s correspondence principle and the local averages of the quantum probability distribution. We illustrate in a clear fashion the difference between Planck’s limit and Bohr’s correspondence principle. We discuss the confinement effect in macroscopic systems.
基金supported by the European Community Sixth RTD Framework Programme (contract FOOD-CT-2005-007034)supported by the Spanish Ministry of Economy and Competitiveness (Grants RYC-2010-05957 and RYC-2011-09011)+3 种基金the Spanish Ministry of Health: Maternal, Child Health and Development Network (Grants RD08/0072 and RD16/0022)the Fondo Europeo de Desarrollo Regional (MICINN-FEDER)the University of Granada, Plan Propio de Investigacion 2016, Excellence actions:Units of ExcellenceUnit of Excellence on Exercise and Health (UCEES)
文摘Purpose: This study aims to compare adolescents' cardiometabolic risk score through an integrative classification of physical activity(PA),which involves the combination of moderate-to-vigorous physical activity(MVPA) and sedentary behavior(SB).Methods: A cross-sectional study derived from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study database(2006-2008) was conducted in adolescents(n = 548; boys, 47.3%; 14.7 ± 1.2 years) from 10 European cities. MVPA and SB were objectively measured using accelerometry. Adolescents were divided into 4 categories according to MVPA(meeting or not meeting the international recommendations) and the median of SB time(above or below sex-and age-specific median) as follows: High-SB & Inactive, Low-SB & Inactive,High-SB & Active, and Low-SB & Active. A clustered cardiometabolic risk score was computed using the homeostatic model assessment, systolic blood pressure, triglycerides, total cholesterol/high-density lipoprotein cholesterol, sum 4 skinfolds, and cardiorespiratory fitness(CRF).Analyses of covariance were performed to discern differences on cardiometabolic risk scores among PA categories and each health component.Results: The cardiometabolic risk score was lower in adolescents meeting the MVPA recommendation and with less time spent in SB in comparison to the high-SB & Inactive group(p < 0.05). However, no difference in cardiometabolic risk score was established between High-SB or Low-SB groups in inactive adolescents. It is important to note that CRF was the only variable that showed a significant modification(higher)when children were compared from the category of physically inactive with "active" but not from high-to low-SB.Conclusion: Being physically active is the most significant and protective outcome in adolescents to reduce cardiometabolic risk. Lower SB does not exhibit a significant and extra beneficial difference.
文摘In this paper, the Ground Penetrating Radar (GPR) method was used to characterize concrete tubes and steel/plastic tanks buried in IAG/USP test site. The microwave tomography was used to improve the GPR images, aiming to retrieve the geometry of the targets. The numerical modeling studies also were done in order to predict the GPR results of the buried targets and to give more reliability to the results interpretation. The targets were installed in the first shallow geophysical test site of the Brazil located at Institute of Astronomy, Geophysics, and Atmospheric Science (IAG) of the University of S?o Paulo (USP). GPR profiles of 200 MHz (shielded bistatic antennas) were acquired along three lines containing concrete tubes and steel/plastic tanks buried in subsoil. The concrete tubes show a hyperbolic reflector for the top, and the vertical tube also presented a reflection on its bottom. The horizontal steel tanks were characterized by a strong GPR reflection on their top. The empty plastic tank shows a strong reflector for the top with normal polarity. On the other hand, the plastic tank filled with water shows a weaker reflector for its top characterized by the inverted polarity of GPR signal when compared with empty plastic tank. The plastic tank filled with water also went characterized by the strong reflection to its bottom, being a good indicative to interpret GPR data on target in subsoil with some types of fluid inside of tank. The results of polarity difference for the top of tank can be used as guide pattern to identify buried tank empty or filled with water. The application of microwave tomography to the GPR data permitted to determine the position and get a good identification of the edges of the targets studied. The numeric modeling presented a good accordance with real data reducing the ambiguities in interpretation of results. These results can be used as a reference, and they can be extrapolated for areas where there is no subsurface information.
文摘The model profession uses the appearance for the representation of products and brands via events. For some individuals that are included in this medium, plus a laboral activity, modeling becomes a lifestyle, the search for the status and work opportunities turn a dream for a thousands of children and teenagers because the profession has particulars experiences. To win this, many girls change physical and eating behaviors which are harmful to health. The objective of this study was to analyze the health-related physical fitness in female models comparing them with non-models. The study was conducted at the Caxias do Sul, Rio Grande do Sul, Brazil. Participated of the study female runway and commercial models bokered in Cast One Models, with age between 15 - 25 years old. The non-models were students from public and private schools or university students. The health-related physical fitness, the physical activity levels and dietary intake were assessed of all participants. The data were described as mean and standard deviation. For comparison between models and non-models was used t independent test for variables normally distributed and U Mann-Whitney test for not normally distributed variables, adopting a level of significance (α) of 0.05. It was found difference in total energy between model group and non-model (GM: 1509.78 kcal, NM: 2292.51 Kcal;p = 0.014). There were no differences between groups in the others variables analyzed (p > 0.05). In conclusion, the profession model seems not interfere in variables that make up the health-related physical fitness.
基金The authors acknowledge the support of the Division of Biological Science and Health of the University of Sonora for the Project USO313006744。
文摘This study aimed to characterize the physical-chemical and biological properties of pectin(PC)/chia seed mucilage(CM)membranes.PC/CM[100/0(control),80/20%,60/40%,and 40/60%w/w]membranes were prepared using the casting method.The membranes(PC/CM)were thin,yellow,lightly opaque(≈10%)and capable of blocking light UVB(between 66 at 52%).SEM analysis showed the presence of aggregates in the shape of a sphere(≈13μm)and ovoid(≈25μm).The proportion of 80/20 showed an increase in tensile strength(29%)and elastic modulus(19%)when compared to the control.FTIR analysis exhibited intermolecular interactions between PCPC,PC-CM,and CM-CM in the membranes.The thermal analysis(600°C)showed a slight improvement in the percentage of residual mass-loss of 3.31%(80/20)that control.The 40/60 membrane showed the lowest percentage of hemolysis(2.94%)but limited human albumin adsorption capacity.These results suggested that the blend PC/CM may be considered as a biomaterial for medical applications.
文摘Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.
文摘This work presents the climatology of the microphysics and the dynamics of weather systems in two coastal areas of São Paulo and the Espírito States at high spatial-temporal resolution as measured by two dual Doppler weather radars during the summer and early fall of 2015. Averages and respective standard deviations of polarimetric variables, namely, reflectivity (Z), differential reflectivity (Z<sub>DR</sub>), differential phase (ϕ<sub>DP</sub>), specific differential phase (K<sub>DP</sub>), copolar correlation coefficient (ρ<sub>oHV</sub>), radial velocity (V<sub>r</sub>), and the spectral width (W) were obtained within a 240-km range on plan position indicator (PPI), constant altitude plan position indicator (CAPPI) and vertical cross-sections to analyze overall horizontal and vertical precipitation microphysics and mesoscale circulation of prevailing weather systems, and their peculiarities over coastal and oceanic, and urban and rural areas. Overall, raindrops tend to be larger over the Metropolitan area of São Paulo from the surface to up to 6 km altitude indicating more vigorous updrafts caused by the heat island effect and the local sea breeze. The vertical microphysical structure is remarkably distinct over the Metropolitan Area of São Paulo (MASP) where thunderstorms can reach 20-km altitude in summertime under sea breeze and heat island effects. On the other hand, there is a dominancy of smaller drop sizes though larger ones observed close to the surface by the coast of Espírito Santo and at the land-ocean interface influenced by the local low-level jet and oceanic-type CCN. Convective cells tend to be smaller associated with Easterlies and more organized with Westerlies. The results indicate distinct features on hydrometeor types and circulation characteristics under these different surface and boundary-layer conditions in close agreement with previous results in the literature.
