The invariant subspace method is used to construct the explicit solution of a nonlinear evolution equation. The second-order nonlinear differential operators that possess invariant subspaces of submaximal dimension ar...The invariant subspace method is used to construct the explicit solution of a nonlinear evolution equation. The second-order nonlinear differential operators that possess invariant subspaces of submaximal dimension are described. There are second-order nonlinear differential operators, including cubic operators and quadratic operators, which preserve an invariant subspace of submaximal dimension. A full. description, of the second-order cubic operators with constant coefficients admitting a four-dimensional invariant subspace is given. It is shown that the maximal dimension of invaxiant subspaces preserved by a second-order cubic operator is four. Several examples are given for the construction of the exact solutions to nonlinear evolution equations with cubic nonlinearities. These solutions blow up in a finite展开更多
According to Hall,a subgroup H of a group G is said to be pronormal if H and H^(g) are conjugate in<H,H^(g)>for every g∈G.In this survey,we discuss the role of pronormality for some subgroups of finite groups:H...According to Hall,a subgroup H of a group G is said to be pronormal if H and H^(g) are conjugate in<H,H^(g)>for every g∈G.In this survey,we discuss the role of pronormality for some subgroups of finite groups:Hall subgroups,subgroups of odd index,submaximal X-subgroup,etc.展开更多
Mobile power meters allow for cyclists to monitor power output （PO） during training and competition. The Garrnin Vector power meter （VPM） measures PO at the pedal compared to the crank and has been tested in only ...Mobile power meters allow for cyclists to monitor power output （PO） during training and competition. The Garrnin Vector power meter （VPM） measures PO at the pedal compared to the crank and has been tested in only a few limited studies. The purpose of this study was to determine the validity and reproducibility of the VPM by comparing it to the SRM. The VPM validity was tested by （1） a submaximal incremental test, （2） submaximal constant power test, （3） sprint test, and （4） a field test. The reliability of the VPM was tested by repeating the laboratory tests 10 times over a 6 week span. Significant differences （P = 0.046） were found between the mean POSRM （178 ± 1.8 W） and POVPM （163.5 ± 14.7 W） for the submaximal constant-power test. No significant differences were found between the POMAX SRM and the POMAx VPM. The reproducibility of the VPM was lower than the SRM （CV = 8.52 ±4.0 vs 3.48 ± 1.9, 10.66% vs 5.50%, and 67.7% vs 55.3% for the submaximal incremental test, submaximal constant-power test, and field test respectively）. The POVPM appears to underestimate the POSRM and is less valid and reliable across various cycling efforts.展开更多
The aim of the study was to assess the effects of androgen receptor antagonists on the physical working capacity and activity of some of the key muscle enzymes for the energy supply in rats. Young adult male Wistar ra...The aim of the study was to assess the effects of androgen receptor antagonists on the physical working capacity and activity of some of the key muscle enzymes for the energy supply in rats. Young adult male Wistar rats were divided into two groups. One group received 15 mg kg-1 of flutamide daily for 6 days a week and the other group served as control for 8 weeks. At the beginning and at the end of the experiment, all rats were subjected to submaximal running endurance （SRE）, maximum time to exhaustion （MTE）, and maximal sprinting speed （MSS） tests. At the end of the trial, maximum oxygen consumption （VO2max） test was performed and the levels of testosterone, erythrocytes, hemoglobin as well as enzyme activity of succinate dehydrogenase （SDH）, lactate dehydrogenase （LDH）, and NAD.H2-cytochrome-c reductase （NAD.H2） of the gastrocnemius muscle were measured. Serum testosterone of the flutamide-treated rats was higher than that of the controls, which verifies the effectiveness of the dose chosen. MTE and SRE of the anti-androgen-treated group were lower compared with the initial values. Flutamide treatment decreased the activity of SDH and NAD.H2 compared with the controls. We found no effect of the anti-androgen treatment on MSS, VO2max, running economy, LDH activity, and hematological variables. Our findings indicate that the maintenance of the submaximal and maximal running endurance as well as the activity of some of the key enzymes associated with muscle oxidative capacity is connected with androgen effects mediated by androgen receptors.展开更多
We compared the effects of low intensity concentric(CON)and eccentric(ECC)exercise on the force and neural responses of the dominant(exercised)elbow flexors(EFs),and studied if these conditions could induce cross-over...We compared the effects of low intensity concentric(CON)and eccentric(ECC)exercise on the force and neural responses of the dominant(exercised)elbow flexors(EFs),and studied if these conditions could induce cross-over effects to the contralateral(non-exercised)EFs.Fifteen subjects(8 males)completed all conditions(CON and ECC:6 sets of low intensity exercise to failure;control:rest)in separate visits with a randomized order.Maximal isometric force and electromyography(EMG)of the dominant and contralateral EFs were assessed at pre,immediate-,24-,and 48-h-post.Two-factor(condition and time)linear mixed-model analyses were performed to examine the force and EMG responses.Immediately post CON,contralateral EFs force was significantly(p=0.026)higher(12.41%)than control,but no cross-over effects regarding the neural responses were observed.Immediately post ECC,dominant EFs force was significantly lower in ECC,compared to CON(p=0.003)and control(p<0.001).This force remained depressed at 24-and 48-h post ECC,when compared to CON(p<0.001)and control(p<0.001).Our data suggests that submaximal unilateral exercises are not likely to impair contralateral muscle strength performance.Instead,concentric exercises may acutely improve muscle strength for the contralateral limb.However,this effect is not explained by changes in muscle excitation.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.10926082)the Natural Science Foundation of Anhui Province of China(Grant No.KJ2010A128)the Fund for Youth of Anhui Normal University,China(Grant No.2009xqn55)
文摘The invariant subspace method is used to construct the explicit solution of a nonlinear evolution equation. The second-order nonlinear differential operators that possess invariant subspaces of submaximal dimension are described. There are second-order nonlinear differential operators, including cubic operators and quadratic operators, which preserve an invariant subspace of submaximal dimension. A full. description, of the second-order cubic operators with constant coefficients admitting a four-dimensional invariant subspace is given. It is shown that the maximal dimension of invaxiant subspaces preserved by a second-order cubic operator is four. Several examples are given for the construction of the exact solutions to nonlinear evolution equations with cubic nonlinearities. These solutions blow up in a finite
基金supported by a NNSF Grant of China(Grant#11771409)Wu Wen-Tsun Key Laboratory of Mathematics of Chinese Academy of Sciencesby SB RAS Fundamental Research Program I.1.1(project#0314-2016-0001).
文摘According to Hall,a subgroup H of a group G is said to be pronormal if H and H^(g) are conjugate in<H,H^(g)>for every g∈G.In this survey,we discuss the role of pronormality for some subgroups of finite groups:Hall subgroups,subgroups of odd index,submaximal X-subgroup,etc.
文摘Mobile power meters allow for cyclists to monitor power output （PO） during training and competition. The Garrnin Vector power meter （VPM） measures PO at the pedal compared to the crank and has been tested in only a few limited studies. The purpose of this study was to determine the validity and reproducibility of the VPM by comparing it to the SRM. The VPM validity was tested by （1） a submaximal incremental test, （2） submaximal constant power test, （3） sprint test, and （4） a field test. The reliability of the VPM was tested by repeating the laboratory tests 10 times over a 6 week span. Significant differences （P = 0.046） were found between the mean POSRM （178 ± 1.8 W） and POVPM （163.5 ± 14.7 W） for the submaximal constant-power test. No significant differences were found between the POMAX SRM and the POMAx VPM. The reproducibility of the VPM was lower than the SRM （CV = 8.52 ±4.0 vs 3.48 ± 1.9, 10.66% vs 5.50%, and 67.7% vs 55.3% for the submaximal incremental test, submaximal constant-power test, and field test respectively）. The POVPM appears to underestimate the POSRM and is less valid and reliable across various cycling efforts.
文摘The aim of the study was to assess the effects of androgen receptor antagonists on the physical working capacity and activity of some of the key muscle enzymes for the energy supply in rats. Young adult male Wistar rats were divided into two groups. One group received 15 mg kg-1 of flutamide daily for 6 days a week and the other group served as control for 8 weeks. At the beginning and at the end of the experiment, all rats were subjected to submaximal running endurance （SRE）, maximum time to exhaustion （MTE）, and maximal sprinting speed （MSS） tests. At the end of the trial, maximum oxygen consumption （VO2max） test was performed and the levels of testosterone, erythrocytes, hemoglobin as well as enzyme activity of succinate dehydrogenase （SDH）, lactate dehydrogenase （LDH）, and NAD.H2-cytochrome-c reductase （NAD.H2） of the gastrocnemius muscle were measured. Serum testosterone of the flutamide-treated rats was higher than that of the controls, which verifies the effectiveness of the dose chosen. MTE and SRE of the anti-androgen-treated group were lower compared with the initial values. Flutamide treatment decreased the activity of SDH and NAD.H2 compared with the controls. We found no effect of the anti-androgen treatment on MSS, VO2max, running economy, LDH activity, and hematological variables. Our findings indicate that the maintenance of the submaximal and maximal running endurance as well as the activity of some of the key enzymes associated with muscle oxidative capacity is connected with androgen effects mediated by androgen receptors.
文摘We compared the effects of low intensity concentric(CON)and eccentric(ECC)exercise on the force and neural responses of the dominant(exercised)elbow flexors(EFs),and studied if these conditions could induce cross-over effects to the contralateral(non-exercised)EFs.Fifteen subjects(8 males)completed all conditions(CON and ECC:6 sets of low intensity exercise to failure;control:rest)in separate visits with a randomized order.Maximal isometric force and electromyography(EMG)of the dominant and contralateral EFs were assessed at pre,immediate-,24-,and 48-h-post.Two-factor(condition and time)linear mixed-model analyses were performed to examine the force and EMG responses.Immediately post CON,contralateral EFs force was significantly(p=0.026)higher(12.41%)than control,but no cross-over effects regarding the neural responses were observed.Immediately post ECC,dominant EFs force was significantly lower in ECC,compared to CON(p=0.003)and control(p<0.001).This force remained depressed at 24-and 48-h post ECC,when compared to CON(p<0.001)and control(p<0.001).Our data suggests that submaximal unilateral exercises are not likely to impair contralateral muscle strength performance.Instead,concentric exercises may acutely improve muscle strength for the contralateral limb.However,this effect is not explained by changes in muscle excitation.
