•The current study compared the effectiveness of three reading interventions.•Hybrid and QT promoted high-level comprehension and critical-analytic thinking.•Hybrid fifth graders had higher reading ...comprehension than TWA.•Hybrid and QT conditions boosted students’ oral reading fluency.
Comprehending and critically analyzing complex, content-rich text is an essential requirement of academic excellence as well as a life-long skill for students. Unfortunately, students often struggle to comprehend print and digital media, and subsequently, they are unable to complete essential tasks, such as identifying information, making inferences, examining arguments, or vetting sources. In the present study, we compared the effectiveness of three reading interventions (i.e., Quality Talk (QT), Think before reading, think While reading, think After reading (TWA), and TWA/QT Hybrid) in promoting fourth- and fifth-grade students’ reading comprehension and critical–analytic thinking. Specifically, teachers in each intervention delivered the respective instructional mini-lessons in their language arts classes and conducted weekly text-based discussions. The results suggested that the Hybrid and QT interventions were effective at promoting high-level comprehension among fourth- and fifth-grade students. Evidence supported that students participating in the Hybrid and QT interventions engaged in more critical–analytic thinking during text-based discussions than those who received the TWA intervention, as evidenced by statistically significantly greater numbers of student-generated authentic questions and elaborated explanations. The Hybrid and QT interventions were also found to effectively boost students’ oral reading fluency in both grades across two phases. Moreover, fifth-grade students who participated in the Hybrid intervention outperformed their peers from the TWA group on the post-discussion reading comprehension assessments.
2S-Hesperidin is the main flavonoid of orange (Citrus sinensis). Previous researches have pointed its effects in muscle development and fat accumulation reduction, although most of these results have ...not been assessed in humans. The objective of this study is to evaluate the effect of chronic (8-weeks) intake of 2S-hesperidin on amateur cyclists’ body composition. A double-blind, parallel and randomized trial, was carried out with 40 amateur cyclists that were divided in two groups, one taking 2S-hesperidin (500 mg d−1, n = 20) and another taking placebo (500 mg d−1 microcellulose, n = 20) for 8 weeks. Dual-energy X-ray absorptiometry (DXA) and anthropometric measurements were used to assess the effect of both treatments on body composition. In addition, the resting metabolic rate was measured. In comparison to placebo, DXA analysis showed a decrease in percentage body fat (%BF) (−10.4%; p = 0.035) and lower limb fat mass (−10.5%; p = 0.029) in favour of 2S-hesperidin. After evaluation of anthropometric data, a decrease in %BF (−3.7%; p = 0.006), total body fat (−3.0%; p = 0.047), ∑ of 8 skinfolds (−6.1%; p = 0.008) was observed in 2S-hesperidin group, but not in placebo. Additionally, there was an increase in muscle mass percentage (1.0%; p = <0.001) and total muscle mass (1.7%; p = 0.011) after ingestion of 2S-hesperidin, with no changes in placebo. Chronic intake of 2S-hesperidin decreased fat mass in amateur cyclists, evaluated through different body composition measurement methodologies (DXA and anthropometry). In addition, 2S-hesperidin supplementation showed a promoting effect on muscle development.
Steroid use has prolonged ambulation in Duchenne muscular dystrophy (DMD) and combined with advances in respiratory care overall management has improved such that cardiac manifestations have become ...the major cause of death. Unfortunately, there is no consensus for DMD-associated cardiac disease management. Our purpose was to assess effects of steroid use alone or in combination with angiotensin converting enzyme inhibitors (ACEI) or angiotension receptor blocker (ARB) on cardiovascular magnetic resonance (CMR) derived circumferential strain (εcc).
We used CMR to assess effects of corticosteroids alone (Group A) or in combination with ACEI or ARB (Group B) on heart rate (HR), left ventricular ejection fraction (LVEF), mass (LVM), end diastolic volume (LVEDV) and circumferential strain (εcc) in a cohort of 171 DMD patients >5 years of age. Treatment decisions were made independently by physicians at both our institution and referral centers and not based on CMR results.
Patients in Group A (114 studies) were younger than those in Group B (92 studies)(10 ± 2.4 vs. 12.4 ± 3.2 years, p < 0.0001), but HR, LVEF, LVEDV and LVM were not different. Although εcc magnitude was lower in Group B than Group A (-13.8 ± 1.9 vs. -12.8 ± 2.0, p = 0.0004), age correction using covariance analysis eliminated this effect. In a subset of patients who underwent serial CMR exams with an inter-study time of ~15 months, εcc worsened regardless of treatment group.
These results support the need for prospective clinical trials to identify more effective treatment regimens for DMD associated cardiac disease.
Purpose
:
To compare the effects of 2 different intensity distribution training programs (threshold THR and polarized POL) on fat metabolism and neuromuscular variables.
Methods
:
Twenty ultrarunners ...were allocated to POL (n = 11; age 40.6 9.7 y, weight 73.5 10.8 kg, VO
2
max 55.8 4.9 mL·kg
−1
·min
−1
) or THR group (n = 9; age 36.8 9.2 y, weight 75.5 10.4 kg, VO
2
max 57.1 5.2 mL·kg
−1
·min
−1
) and performed a 12-week training program that consisted of 5 running sessions, 2 strength sessions, and 1 day of full rest per week. Both groups performed similar total training duration and load but with different intensity distribution during running sessions. Resting metabolic rate, fat metabolism, isometric rate of force development (RFD; N·s
−1
) and maximal voluntary contraction in the knee extensor, and electromyographic amplitude were measured before and after each program.
Results
:
A significant decrease in RFD
0–100 ms
(Δ −13.4%;
P
≤ .001; effect size ES = 1.00), RFD
0–200 ms
(Δ −11.7%;
P
≤ .001; ES = 1.4), and RFD
peak
(Δ −18%;
P
≤ .001; ES = 1.4) were observed in the POL group. In THR group, a significant increase in mean electromyographic amplitude (Δ 24.4%;
P
= .02; ES = 1.4) was observed. There were no significant differences between groups in any of the variables.
Conclusions
:
Similar adaptations in fat metabolism and neuromuscular performance can be achieved after 12 weeks of POL or THR intensity distribution. However, THR distribution appears to better maintain strength (RFD) and improve mean electromyographic amplitude. Nevertheless, the combination of both running and maximum strength training could influence on results because of the residual fatigue thus inducing suboptimal adaptations in the POL group.
Hypoxic training methods are increasingly being used by researchers in an attempt to improve performance in normoxic ambients. Moreover, previous research suggests that resistance training in hypoxia ...can cause physiological and muscle adaptations. The primary aim of this study was to compare the effects of 8 weeks of high-intensity resistance circuit-based (HRC) training in hypoxia on body composition and strength performance. The secondary aim was to examine the effects of HRC on metabolic parameters. Twenty-eight male participants were randomly assigned to either hypoxia (Fraction of inspired oxygen F
I
O
2
= 15%; HRC
hyp
: n = 15; age: 24.6 ± 6.8 years; height: 177.4 ± 5.9 cm; weight: 74.9 ± 11.5 kg) or normoxia F
I
O
2
= 20.9%; HRC
norm
: n = 13; age: 23.2 ± 5.2 years; height: 173.4 ± 6.2 cm; weight: 69.4 ± 7.4 kg) groups. Training sessions consisted of two blocks of three exercises (Block 1: bench press, leg extension and front pull down; Block 2: deadlift, elbow flexion and ankle extension). Each exercise was performed at six repetition maximum. Rest periods lasted for 35-s between exercises, 3-min between sets and 5-min between blocks. Participants exercised twice weekly for 8 weeks, and body composition, strength and blood tests were performed before and after the training program. Lean body mass and bone mineral density significantly increased over time in the HRC
hyp
(p < .005; ES = 0.14 and p < .014; ES = 0.19, respectively) but not in the HRC
norm
after training. Both groups improved their strength performance over time (p < .001), but without group effect differences. These results indicate that simulated hypoxia during HRC exercise produced trivial effects on lean body mass and bone mineral density compared to normoxia.
COH29 N-(4-(3,4-dihydroxyphenyl)-5-phenylthiazol-2-yl)-3,4-dihydroxybenzamide, a novel antimetabolite drug developed at City of Hope Cancer Center, has anticancer activity that stems primarily from ...the inhibition of human ribonucleotide reductase (RNR). This key enzyme in deoxyribonucleotide biosynthesis is the target of established clinical agents such as hydroxyurea and gemcitabine because of its critical role in DNA replication and repair. Herein we report that BRCA-1-defective human breast cancer cells are more sensitive than wild-type BRCA-1 counterparts to COH29 in vitro and in vivo. Microarray gene expression profiling showed that COH29 reduces the expression of DNA repair pathway genes, suggesting that COH29 interferes with these pathways. It is well established that BRCA1 plays a role in DNA damage repair, especially homologous recombination (HR) repair, to maintain genome integrity. In BRCA1-defective HCC1937 breast cancer cells, COH29 induced more double-strand breaks (DSBs) and DNA-damage response than in HCC1937 + BRCA1 cells. By EJ5- and DR-green fluorescent protein (GFP) reporter assay, we found that COH29 could inhibit nonhomologous end joining (NHEJ) efficiency and that no HR activity was detected in HCC1937 cells, suggesting that repression of the NHEJ repair pathway may be involved in COH29-induced DSBs in BRCA1-deficient HCC1937 cells. Furthermore, we observed an accumulation of nuclear Rad51 foci in COH29-treated HCC1937 + BRCA1 cells, suggesting that BRCA1 plays a crucial role in repairing and recovering drug-induced DNA damage by recruiting Rad51 to damage sites. In summary, we describe here additional biologic effects of the RNR inhibitor COH29 that potentially strengthen its use as an anticancer agent.
Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts
Submitted 21 March 2007
; accepted in final form 7 August 2007
During voluntary contractions, the skeletal muscle of ...healthy older adults often fatigues less than that of young adults, a result that has been explained by relatively greater reliance on muscle oxidative metabolism in the elderly. Our aim was to investigate whether this age-related fatigue resistance was eliminated when oxidative metabolism was minimized via ischemia induced by cuff (220 mmHg). We hypothesized that 1 ) older men ( n = 12) would fatigue less than young men ( n = 12) during free-flow (FF) contractions; 2 ) both groups would fatigue similarly during ischemia; and 3 ) reperfusion would reestablish the fatigue resistance of the old. Subjects performed 6 min of intermittent, maximal voluntary isometric contractions of the ankle dorsiflexors under FF and ischemia-reperfusion (IR) conditions. Ischemia was maintained for the first 3 min of contractions, followed by rapid cuff deflation and reperfusion for 3 additional minutes of contractions. Central activation, peripheral activation, and muscle contractile properties were measured at 3 and 6 min of contractions. Older men fatigued less than young men during FF ( P 0.02), ischemia ( P < 0.001), and reperfusion ( P < 0.001). During FF, activation and contractile properties changed similarly across age groups. At the end of ischemia, central ( P = 0.02) and peripheral ( P 0.03) activation declined more in the young, with no effect of age on the changes in contractile properties. Thus age-related fatigue resistance was evident during FF and IR, indicating that differences in blood flow and oxidative metabolism do not explain the fatigue resistance of old age.
central activation; peripheral activation; contractile properties; muscle strength; reperfusion; isometric
Address for reprint requests and other correspondence: J. Kent-Braun, Dept. of Kinesiology, Univ. of Massachusetts, 108 Totman Bldg., 30 Eastman Lane, Amherst, MA 01003 (e-mail: janekb{at}kin.umass.edu )
The purpose of the present systematic review and meta-analysis was to evaluate published, randomized controlled trials that investigated the effects of whole-body vibration training (WBVT) on lean ...mass in postmenopausal women.
The following electronic databases were searched from September to October 2015: PubMed, Web of Science, and Cochrane. Two different authors tabulated, independently, the selected indices in identical predetermined forms. The methodological quality of all randomized trial studies was evaluated according to the modified PEDro scale. In each trial, the effect size of the intervention was calculated by the difference between pre- and postintervention lean mass in WBVT postmenopausal women. For controlled trials, the effect size of the WBVT was also calculated by the difference in lean mass after the WBVT and in control participants.
Of the 189 articles found from the database search and all duplicates removed, 5 articles were analyzed. The lean mass of 112 postmenopausal women who performed either WBVT or a control protocol was evaluated. The methodological quality of the trials was high, where the mean score was 8 out of a possible 10 points. No significant improvements in lean mass with WBVT were found in postmenopausal women. In addition, there was no significant difference in lean mass between WBVT and control postmenopausal women.
This meta-analysis demonstrated that WBVT alone may not be a sufficient stimulus to increase lean mass in postmenopausal women. Thus, additional complimentary training methods with WBVT are needed to increase muscle size in women with lower hormonal responses.
•There are no differences on neuromuscular variables, except EMG, after a WBVT session in both conditions.•A WBVT session does not acutely worsen functional variables.•EMG decreases after WBV session ...in hypoxia, which could show a greater stimulus in this condition.
Whole-body vibration training (WBVT) has been used in people with relapsing-remitting multiple sclerosis (pwMS), showing improvements in different neuromuscular and mobility variables. However, the acute effects of this training are still unknown. The acute effects of WBVT on neuromuscular performance, mobility and rating of perceived exertion (RPE) were evaluated in 10 pwMS.
Maximal voluntary isometric contraction (MVIC), central activation ratio (CAR), electromyography (EMG) of the vastus lateralis during isometric knee extension, Timed Up and Go Test (TUG), walking speed and RPE were assessed before and immediately after a session of WBVT (twelve 60-s bout of vibration; frequency 35 Hz; amplitude 4 mm; 1-min rest intervals) in both hypoxic and normoxic conditions.
EMG 0–100, 0–200 ms and peak EMG resulted in significant differences (p < 0.05) between normoxic and hypoxic sessions. The EMG activity tended to decrease in all phases after the hypoxic session, indicating possible influence of hypoxia on neuromuscular performance. No changes were found in CAR, MVIC, TUG and walking speed in both conditions.
Based on our results, as well as those obtained by other studies that have used WBVT with other populations, more studies with a higher sample and lower dose of vibration exposure should be conducted in pwMS.
1 Department of Human Physiology and 2 Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403
Submitted 6 April 2004
; accepted in final form 19 May 2004
Vasoactive intestinal peptide ...(VIP) is known to induce histamine release in human skin and to include a nitric oxide (NO)-dependent dilation in several other vascular beds. However, the relative contribution of histamine and NO to VIP-mediated vasodilation in human skin is unknown. Forty-three subjects volunteered to participate in two studies designed to examine the mechanism of VIP-mediated vasodilation in human skin. Study 1 examined the contribution of NO in the skin blood flow response to eight doses of VIP ranging from 25 to 800 pmol. In addition, study 1 examined a specific role for NO in VIP-mediated dilation. Study 2 examined the relative contribution of NO and histamine to VIP-mediated dilation via H 1 and H 2 histamine receptors. Infusions were administered to skin sites via intradermal microdialysis. Red blood cell flux was measured by using laser-Doppler flowmetry (LDF), and cutaneous vascular conductance (CVC; LDF/mean arterial pressure) was calculated and normalized to maximal vasodilation. VIP-mediated vasodilation includes a NO-dependent component at doses above 100 pmol, where NO synthase inhibition significantly attenuates CVC ( P < 0.05). Inhibition of H 1 receptors attenuates the rise in CVC to exogenous VIP ( P < 0.05); however, combined H 1 -receptor inhibition and NO synthase inhibition further reduced VIP-mediated vasodilation compared with either H 1 inhibition or NO synthase inhibition alone ( P < 0.05). In contrast to H 1 -receptor inhibition, H 2 -receptor inhibition did not affect vasodilation to exogenous VIP. Thus, in human skin, VIP-mediated vasodilation includes a NO-dependent component that could not be explained by H 1 - and H 2 -receptor activation.
cutaneous circulation; nitric oxide; neuropeptides; histamine receptors
Address for reprint requests and other correspondence: C. T. Minson, Dept. of Exercise and Movement Science, 1240 University of Oregon, Eugene, OR 97403-1240 (E-mail: minson{at}oregon.uoregon.edu ).
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