Frequency Reduction and Attenuation of the Tire Air Cavity Mode due to a Porous Lining

The tire air cavity mode is known to be a significant source of vehicle structure-borne road noise near 200 Hz. A porous lining placed on the inner surface of a tire is an effective countermeasure to attenuate that resonance. The two noticeable effects of such a lining are the reduction in the cavity resonance frequency and the attenuation of the air cavity mode. In this paper, through both theoretical and numerical analysis, the mechanisms underlyiing the effects of a porous lining were studied. A two-dimensional duct-shaped theoretical model and a torus-shaped numerical model were created to investigate the lined tire in conjunction with the Johnson-Champoux-Allard model describing the viscous and thermal dissipative effects of the porous material. Design parameters of the porous lining were varied to study their impact and optimal ranges of the design parameters were identified. Finally, in an experimental analysis, the sound attenuation and the frequency drop were observed in measurements of force, acceleration, and sound pressure. In conclusion, it was demonstrated that the suggested theoretical and numerical models successfully predict the effects of porous linings and that the frequency reduction results from the decreased sound speed within the tire owing to the presence of the liner

Effects of heated water-based versus land-based exercise training on vascular function in individuals with peripheral artery disease

Peripheral artery disease (PAD) is an atherosclerotic disease that is associated with poor vascular function, walking impairment, and reduced quality of life. Land-based exercise therapy (LBET) is frequently recommended to improve walking and reduce symptoms. Recently, evidence has suggested that heated-water exercise therapy (HWET) is an effective intervention for PAD. However, the efficacy of LBET versus HWET in PAD patients had not been elucidated. Therefore, we sought to compare effects of LBET with HWET on cardiovascular function, exercise tolerance, physical function, and body composition in PAD patients. PAD patients (n = 53) were recruited and randomly assigned to a LBET group (n = 25) or HWET group (n = 28). The LBET group performed treadmill walking, whereas the HWET group performed walking in heated water for 12 wk. Leg (legPWV) and brachial-to-ankle arterial stiffness (baPWV), blood pressure (BP), ankle-brachial index (ABI), 6-min walking distance (6MWD), claudication onset time (COT), physical function, and body composition were assessed before and after 12 wk. There were significant group-by-time interactions (P \u3c 0.05) for legPWV, BP, 6MWD, COT, body composition, and resting metabolic rate (RMR). Both groups significantly reduced (P \u3c 0.05) legPWV, BP, and body fat percentage, and HWET measures were significantly lower than LBET measures. Both groups significantly increased 6MWD, COT, and RMR, and HWET group measures were significantly greater than LBET measures. A time effect was noted for baPWV reduction in both groups (P \u3c 0.05). These results suggest that both LBET and HWET improve cardiovascular function, exercise tolerance, and body composition, and HWET showed considerably greater improvements compared with LBET in patients with PAD

Arabidopsis ABCG14 is essential for the root-to-shoot translocation of cytokinin.

Cytokinins are phytohormones that induce cytokinesis and are essential for diverse developmental and physiological processes in plants. Cytokinins of the trans-zeatin type are mainly synthesized in root vasculature and transported to the shoot, where they regulate shoot growth. However, the mechanism of long-distance transport of cytokinin was hitherto unknown. Here, we report that the Arabidopsis ATP-binding cassette (ABC) transporter subfamily G14 (AtABCG14) is mainly expressed in roots and plays a major role in delivering cytokinins to the shoot. Loss of AtABCG14 expression resulted in severe shoot growth retardation, which was rescued by exogenous trans-zeatin application. Cytokinin content was decreased in the shoots of atabcg14 plants and increased in the roots, with consistent changes in the expression of cytokinin-responsive genes. Grafting of atabcg14 scions onto wild-type rootstocks restored shoot growth, whereas wild-type scions grafted onto atabcg14 rootstocks exhibited shoot growth retardation similar to that of atabcg14. Cytokinin concentrations in the xylem are reduced by similar to 90% in the atabcg14 mutant. These results indicate that AtABCG14 is crucial for the translocation of cytokinin to the shoot. Our results provide molecular evidence for the long-distance transport of cytokinin and show that this transport is necessary for normal shoot development.open118380Ysciescopu

Habitual Combined Exercise Protects against Age-Associated Decline in Vascular Function and Lipid Profiles in Elderly Postmenopausal Women

Postmenopausal status is associated with increased risks for cardiovascular diseases (CVD). This study investigated differences in vascular function, lipids, body composition, and physical fitness in elderly postmenopausal women active in combined resistance and aerobic exercise (CRAE) training for 1 year versus a sedentary cohort of similar-in-age counterparts. Elderly postmenopausal women performing habitual CRAE training for 1 year (age ~75 year; CRAE, n = 57) and elderly sedentary postmenopausal women (age ~78 year; SED, n = 44) were recruited. Arterial stiffness (brachial-to-ankle pulse-wave velocity, baPWV), blood pressure, blood lipids, anthropometrics, 2-min walking distance, and muscular strength were assessed for both groups. There were significant differences for baPWV, systolic blood pressure, low-density lipoprotein, and body fat percentage, which were significantly lower (p \u3c 0.05) in CRAE vs. SED, and both 2 min walking distance and muscular strength were significantly greater (p \u3c 0.05) in CRAE vs. SED. These results indicate that elderly postmenopausal women participating in habitual CRAE training may have better protection against risks for CVD and have better physical fitness compared to SED counterparts

Mitochondrial targeted antioxidant intake improves vascular function and exercise tolerance in peripheral artery disease patients

Peripheral artery disease (PAD) is a manifestation of atherosclerosis in the leg arteries, which causes reduced blood flow and leg pain. This may be in part due to excessive mitochondria-produced reactive oxygen species (ROS) and attenuated mitochondrial respiratory function. Mitoquinol mesylate, a mitochondrial-targeted antioxidant, has been shown to scavenge ROS and improve vascular function in older adults and animal models. However, the impacts of mitoquinol on vascular function in PAD patients are unknown. We sought to examine the impacts of mitoquinol intake (80mg) on endothelial function (flow mediated dilation, FMD), resting heart rate (RHR), blood pressure (BP), arterial stiffness (pulse wave velocity, PWV), and exercise tolerance in PAD patients. 10 PAD patients (stage II-III) received either mitoquinol or placebo in a randomized crossover design. At each visit, measurements of RHR, BP, brachial and popliteal artery FMD, PWV, augmentation index (AIx), maximal walking capacity, and time to claudication (COT) were measured before and after mitoquinol and placebo. There were significant group by time interactions (ppp=0.10), carotid-to-ankle PWV (p=0.08), and increases in maximal walking time (p=0.06), and maximal walking distance (p=0.06). There were no changes in RHR, systolic BP, central BP, deceleration time, max dP/dt, carotid-to-radial PWV, carotid-to-femoral PWV, or AIx (p\u3e0.05). Mitoquinol intake may be an effective strategy for targeting mitochondrial ROS, which may be useful for treating endothelial dysfunction, leg pain, and improving walking time in PAD patients

The effects of a 12-week jump rope exercise program on abdominal adiposity, vasoactive substances, inflammation, and vascular function in adolescent girls with prehypertension

Introduction Childhood obesity is strongly associated with cardiovascular disease (CVD) development. It is necessary to combat unfavorable outcomes of obesity at a young age by utilizing effective interventions, such as exercise. Purpose We sought to examine the effects of a jump rope exercise program on CVD risk factors, including body composition, vasoactive substances, inflammation, and vascular function in prehypertensive adolescent girls. Methods Forty girls (age 14–16) were recruited and randomly assigned to a jump rope exercise group (EX, n = 20) or control group (CON, n = 20). Body composition, nitrate and nitrite levels, endothelin-1 (ET-1), C-reactive protein (CRP), systolic blood pressure and diastolic blood pressure (SBP, DBP), and arterial stiffness were measured before and after 12 weeks. Results There were significant group by time interactions following the 12-week program for body composition (from 33.8 ± 3.6 to 30.2 ± 3.1%), central adiposity (from 86.4 ± 4 to 83.3 ± 5 cm), SBP (from 126 ± 3.3 to 120 ± 2.1 mmHg), and brachial-to-ankle pulse wave velocity (from 8.2 ± 1.0 to 7.4 ± 0.2 m/s). Nitrate/nitrite levels increased (from 54.5 ± 5.1 to 57.2 ± 5.2 µmol) along a reduction in CRP levels (from 0.5 ± 0.4 to 0.2 ± 0.1 mg/L). There were no significant changes in ET-1 (P = 0.22). Conclusions These findings indicate that jump rope exercise may be an effective intervention to improve these CVD risk factors in prehypertensive adolescent girls. Jumping rope is an easily accessible exercise modality that may have important health implications for CVD prevention in younger populations

A microRNA cluster in the Fragile-X region expressed during spermatogenesis targets FMR1.

Testis-expressed X-linked genes typically evolve rapidly. Here, we report on a testis-expressed X-linked microRNA (miRNA) cluster that despite rapid alterations in sequence has retained its position in the Fragile-X region of the X chromosome in placental mammals. Surprisingly, the miRNAs encoded by this cluster (Fx-mir) have a predilection for targeting the immediately adjacent gene, Fmr1, an unexpected finding given that miRNAs usually act in trans, not in cis Robust repression of Fmr1 is conferred by combinations of Fx-mir miRNAs induced in Sertoli cells (SCs) during postnatal development when they terminate proliferation. Physiological significance is suggested by the finding that FMRP, the protein product of Fmr1, is downregulated when Fx-mir miRNAs are induced, and that FMRP loss causes SC hyperproliferation and spermatogenic defects. Fx-mir miRNAs not only regulate the expression of FMRP, but also regulate the expression of eIF4E and CYFIP1, which together with FMRP form a translational regulatory complex. Our results support a model in which Fx-mir family members act cooperatively to regulate the translation of batteries of mRNAs in a developmentally regulated manner in SCs

Annual Wormwood Leaf Inhibits the Adipogenesis of 3T3-L1 and Obesity in High-Fat Diet-Induced Obese Rats

Annual wormwood (AW) (Artemisia annua L.) has anti-malarial, anti-bacterial, anti-oxidant, anti-tumour, and anti-inflammatory activities. In the present study, we evaluated the effects of annual wormwood leaves (AWL) on adipocyte differentiation in 3T3-L1 cells and high-fat diet (HFD)-induced obese rats. 3T3-L1 adipocytes and HFD-induced obese rats were treated with AWL, and its effect on gene expression was analyzed using RT-PCR and Western blotting experiments. Treatment with AWL effectively prevented triglyceride accumulation during adipogenesis in a dose-dependent manner. Consistently, AWL suppressed the differentiation of 3T3-L1 preadipocytes into adipocytes through the downregulation of dexamethasone, 3-isobutyl-1- methylxanthine, and insulin (DMI)-induced serine/threonine kinase protein kinase B (PKB/Akt) activation and the expression of adipogenic genes, including the CCAAT/enhancer binding protein-alpha (C/EBPalpha) and peroximal proliferator-activated receptor-gamma (PPARgamma). Moreover, the expression of adipocyte fatty acid-binding protein 4 (aP2), which is a known PPARgamma-target gene, was downregulated by AWL treatment. Oral administration of AWL extracts significantly decreased the body weight gain, adipose tissue mass, adipocyte cell size, serum triglyceride (TG), and total cholesterol (TC) levels in HFD-induced obese rats. These results provide novel insight into the molecular mechanisms underlying the anti-obesity effects of AWL that are mediated by the downregulation of the expression of major adipogenic transcription factors, C/EBPalpha and PPARgamma and Akt signalling