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Sample records for early age strength

  1. Early-age concrete strength estimation based on piezoelectric sensor using artificial neural network

    NASA Astrophysics Data System (ADS)

    Kim, Junkyeong; Kim, Ju-Won; Park, Seunghee

    2014-04-01

    Recently, novel methods to estimate the strength of concrete have been reported based on numerous NDT methods. Especially, electro-mechanical impedance technique using piezoelectric sensors are studied to estimate the strength of concrete. However, the previous research works could not provide the general information about the early-age strength important to manage the quality of concrete and/or the construction process. In order to estimate the early-age strength of concrete, the electro-mechanical impedance method and the artificial neural network(ANN) is utilized in this study. The electro-mechanical impedance varies with the mechanical properties of host structures. Because the strength development is most influential factor among the change of mechanical properties at early-age of curing, it is possible to estimate the strength of concrete by analyzing the change of E/M impedance. The strength of concrete is a complex function of several factors like mix proportion, temperature, elasticity, etc. Because of this, it is hard to mathematically derive equations about strength of concrete. The ANN can provide the solution about early-age strength of concrete without mathematical equations. To verify the proposed approach, a series of experimental studies are conducted. The impedance signals are measured using embedded piezoelectric sensors during curing process and the resonant frequency of impedance is extracted as a strength feature. The strength of concrete is calculated by regression of strength development curve obtained by destructive test. Then ANN model is established by trained using experimental results. Finally the ANN model is verified using impedance data of other sensors.

  2. Early-Age Strength of Ultra-High Performance Concrete in Various Curing Conditions.

    PubMed

    Park, Jong-Sup; Kim, Young Jin; Cho, Jeong-Rae; Jeon, Se-Jin

    2015-08-24

    The strength of Ultra-High Performance Concrete (UHPC) can be sensitively affected by the curing method used. However, in contrast to the precast plant production of UHPC where a standard high-temperature steam curing is available, an optimum curing condition is rarely realized with cast-in-place UHPC. Therefore, the trend of the compressive strength development of UHPC was experimentally investigated in this study, with a focus on early-age strength by assuming the various curing conditions anticipated on site. Concrete specimens were cured under different conditions with variables including curing temperature, delay time before the initiation of curing, duration of curing, and moisture condition. Several conditions for curing are proposed that are required when the cast-in-place UHPC should gain a specified strength at an early age. It is expected that the practical use of UHPC on construction sites can be expedited through this study.

  3. Early-Age Strength of Ultra-High Performance Concrete in Various Curing Conditions

    PubMed Central

    Park, Jong-Sup; Kim, Young Jin; Cho, Jeong-Rae; Jeon, Se-Jin

    2015-01-01

    The strength of Ultra-High Performance Concrete (UHPC) can be sensitively affected by the curing method used. However, in contrast to the precast plant production of UHPC where a standard high-temperature steam curing is available, an optimum curing condition is rarely realized with cast-in-place UHPC. Therefore, the trend of the compressive strength development of UHPC was experimentally investigated in this study, with a focus on early-age strength by assuming the various curing conditions anticipated on site. Concrete specimens were cured under different conditions with variables including curing temperature, delay time before the initiation of curing, duration of curing, and moisture condition. Several conditions for curing are proposed that are required when the cast-in-place UHPC should gain a specified strength at an early age. It is expected that the practical use of UHPC on construction sites can be expedited through this study. PMID:28793522

  4. Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors.

    PubMed

    Yoon, Hyejin; Kim, Young Jin; Kim, Hee Seok; Kang, Jun Won; Koh, Hyun-Moo

    2017-08-07

    Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal time and reducing construction time and costs. In this paper, the feasibility of using surface wave velocities to predict the strength of in situ concrete inside the form at a very early stage was evaluated. Ultrasonic sensors were used to measure a series of surface waves for concrete inside a form in the first 24 h after placement. A continuous wavelet transform was used to compute the travel time of the propagating surface waves. The cylindrical compressive strength and penetration resistance tests were also performed during the test period. Four mixtures and five curing temperatures were used for the specimens. The surface wave velocity was confirmed to be applicable to estimating the concrete strength at a very early age in wall-like elements. An empirical formula is proposed for evaluating the early-age compressive strength of concrete considering the 95% prediction intervals.

  5. Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors

    PubMed Central

    Yoon, Hyejin; Kim, Young Jin; Kim, Hee Seok; Kang, Jun Won; Koh, Hyun-Moo

    2017-01-01

    Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal time and reducing construction time and costs. In this paper, the feasibility of using surface wave velocities to predict the strength of in situ concrete inside the form at a very early stage was evaluated. Ultrasonic sensors were used to measure a series of surface waves for concrete inside a form in the first 24 h after placement. A continuous wavelet transform was used to compute the travel time of the propagating surface waves. The cylindrical compressive strength and penetration resistance tests were also performed during the test period. Four mixtures and five curing temperatures were used for the specimens. The surface wave velocity was confirmed to be applicable to estimating the concrete strength at a very early age in wall-like elements. An empirical formula is proposed for evaluating the early-age compressive strength of concrete considering the 95% prediction intervals. PMID:28783128

  6. Artificial Neural Network-Based Early-Age Concrete Strength Monitoring Using Dynamic Response Signals

    PubMed Central

    Kim, Junkyeong; Lee, Chaggil; Park, Seunghee

    2017-01-01

    Concrete is one of the most common materials used to construct a variety of civil infrastructures. However, since concrete might be susceptible to brittle fracture, it is essential to confirm the strength of concrete at the early-age stage of the curing process to prevent unexpected collapse. To address this issue, this study proposes a novel method to estimate the early-age strength of concrete, by integrating an artificial neural network algorithm with a dynamic response measurement of the concrete material. The dynamic response signals of the concrete, including both electromechanical impedances and guided ultrasonic waves, are obtained from an embedded piezoelectric sensor module. The cross-correlation coefficient of the electromechanical impedance signals and the amplitude of the guided ultrasonic wave signals are selected to quantify the variation in dynamic responses according to the strength of the concrete. Furthermore, an artificial neural network algorithm is used to verify a relationship between the variation in dynamic response signals and concrete strength. The results of an experimental study confirm that the proposed approach can be effectively applied to estimate the strength of concrete material from the early-age stage of the curing process. PMID:28590456

  7. Artificial Neural Network-Based Early-Age Concrete Strength Monitoring Using Dynamic Response Signals.

    PubMed

    Kim, Junkyeong; Lee, Chaggil; Park, Seunghee

    2017-06-07

    Concrete is one of the most common materials used to construct a variety of civil infrastructures. However, since concrete might be susceptible to brittle fracture, it is essential to confirm the strength of concrete at the early-age stage of the curing process to prevent unexpected collapse. To address this issue, this study proposes a novel method to estimate the early-age strength of concrete, by integrating an artificial neural network algorithm with a dynamic response measurement of the concrete material. The dynamic response signals of the concrete, including both electromechanical impedances and guided ultrasonic waves, are obtained from an embedded piezoelectric sensor module. The cross-correlation coefficient of the electromechanical impedance signals and the amplitude of the guided ultrasonic wave signals are selected to quantify the variation in dynamic responses according to the strength of the concrete. Furthermore, an artificial neural network algorithm is used to verify a relationship between the variation in dynamic response signals and concrete strength. The results of an experimental study confirm that the proposed approach can be effectively applied to estimate the strength of concrete material from the early-age stage of the curing process.

  8. Association of postural balance and isometric muscle strength in early- and middle-school-age boys.

    PubMed

    Ibrahim, Alaa I; Muaidi, Qassim I; Abdelsalam, Mohammed S; Hawamdeh, Ziad M; Alhusaini, Adel A

    2013-01-01

    The purpose of this study was to evaluate the isometric muscle strength (IMS) and dynamic balance in early- and middle-school-age boys and to assess the strength of association between the dynamic balance scores and 6 different IMS indexes. This is a cross-sectional study of a convenience sample of 94 boys who were 6 to 10 years of age and classified into an early school age (6-8 years) group (n = 50) and a middle school age (8-10 years) group (n = 44). Balance was tested using a Biodex Balance System. Anteroposterior Stability Index, Mediolateral Stability Index, and Overall Stability Index were recorded. IMS of 11 muscle groups was measured with a handheld dynamometer and categorized into 6 different muscle strength indices. The mean (SD) values of anteroposterior, mediolateral, and overall stability indexes observed for all study boys were 1.9 ± 1.0, 1.2 ± 0.7, and 2.5 ± 1.2 respectively. In the middle school age group, strong positive relationships were detected between the overall stability index and trunk, lower limb, anti-gravity, pro-gravity, and total strength indexes (r = -0.86/P < .001, r = -0.91/P < .001, r = -0.88/P < .001, r = -0.83/P < .001, and r = -0.84/P < .001 respectively), while no significant relationship was detected with the upper limb strength index (r = 0.159/P = .303). In the early school age group, moderate positive relationships were detected between the overall stability index and anti-gravity, lower limb, and total strength indexes (r = -0.404/P = .004, r = -0.356/P = .011, and r = -0.350/P = .013 respectively). Dynamic balance did not appear to be mature by the age of 10 years. Better balance skills were recorded in the mediolateral direction than in the anteroposterior direction. In the middle school age group, the overall stability index had positive relationships with almost all examined muscle strength indexes excepting the upper limb strength index. © 2013. Published by National University of Health Sciences All rights

  9. On the Relation of Setting and Early-Age Strength Development to Porosity and Hydration in Cement-Based Materials.

    PubMed

    Lootens, Didier; Bentz, Dale P

    2016-04-01

    Previous research has demonstrated a linear relationship between compressive strength (mortar cubes and concrete cylinders) and cumulative heat release normalized per unit volume of (mixing) water for a wide variety of cement-based mixtures at ages of 1 d and beyond. This paper utilizes concurrent ultrasonic reflection and calorimetry measurements to further explore this relationship from the time of specimen casting to 3 d. The ultrasonic measurements permit a continuous evaluation of thickening, setting, and strength development during this time period for comparison with the ongoing chemical reactions, as characterized by isothermal calorimetry measurements. Initially, the ultrasonic strength-heat release relation depends strongly on water-to-cement ratio, as well as admixture additions, with no universal behavior. Still, each individual strength-heat release curve is consistent with a percolation-based view of the cement setting process. However, beyond about 8 h for the systems investigated in the present study, the various strength-heat release curves merge towards a single relationship that broadly characterizes the development of strength as a function of heat released (fractional space filled), demonstrating that mortar and/or concrete strength at early ages can be effectively monitored using either ultrasonic or calorimetry measurements on small paste or mortar specimens.

  10. On the Relation of Setting and Early-Age Strength Development to Porosity and Hydration in Cement-Based Materials

    PubMed Central

    Lootens, Didier; Bentz, Dale P.

    2016-01-01

    Previous research has demonstrated a linear relationship between compressive strength (mortar cubes and concrete cylinders) and cumulative heat release normalized per unit volume of (mixing) water for a wide variety of cement-based mixtures at ages of 1 d and beyond. This paper utilizes concurrent ultrasonic reflection and calorimetry measurements to further explore this relationship from the time of specimen casting to 3 d. The ultrasonic measurements permit a continuous evaluation of thickening, setting, and strength development during this time period for comparison with the ongoing chemical reactions, as characterized by isothermal calorimetry measurements. Initially, the ultrasonic strength-heat release relation depends strongly on water-to-cement ratio, as well as admixture additions, with no universal behavior. Still, each individual strength-heat release curve is consistent with a percolation-based view of the cement setting process. However, beyond about 8 h for the systems investigated in the present study, the various strength-heat release curves merge towards a single relationship that broadly characterizes the development of strength as a function of heat released (fractional space filled), demonstrating that mortar and/or concrete strength at early ages can be effectively monitored using either ultrasonic or calorimetry measurements on small paste or mortar specimens. PMID:27046956

  11. Early age strength enhancement of blended cement systems by CaCl{sub 2} and diethanol-isopropanolamine

    SciTech Connect

    Riding, Kyle; Silva, Denise A.; Scrivener, Karen

    2010-06-15

    The enhancement of the 1 day strength of cementitious systems by a combination of calcium chloride (CaCl{sub 2}) and diethanol-isopropanolamine (DEIPA) was studied, particularly in blended cement systems. A combination of quantitative X-ray diffraction with Rietveld refinement (QXRD), scanning electron microscopy (SEM)/backscattered electron image analysis, thermogravimetric analysis (TGA), and isothermal calorimetry were used to investigate the mechanism of strength enhancement by the additives. The additives were found to increase the early age mortar strength by enhancing the cement hydration, with the DEIPA enhancing primarily the aluminate hydration. DEIPA also affected the morphology of portlandite which was formed as thin plates. In parallel, the calcium-to-silica ratio of the C-S-H was found to increase with the use of DEIPA, possibly because of the inclusion of microcrystalline portlandite. After 48 h DEIPA was found to directly enhance the rate of reaction of granulated blast-furnace slag and fly ash.

  12. Effects of 4 weeks of traditional resistance training vs. superslow strength training on early phase adaptations in strength, flexibility, and aerobic capacity in college-aged women.

    PubMed

    Kim, Eonho; Dear, Alexis; Ferguson, Steven L; Seo, Dongil; Bemben, Michael G

    2011-11-01

    This study compared SuperSlow resistance training (SRT) to traditional resistance training (TRT) during early phase adaptations in strength, aerobic capacity, and flexibility in college-aged women. Subjects were randomly assigned to SRT (n = 14); TRT (n = 13); or control (CON; n = 8) groups. To equalize training times, TRT trained 3 times per week for 25 minutes each session, whereas SRT trained twice a week for 35 minutes each session. Both groups trained for 4 weeks, whereas the CON group maintained normal daily activities. Workouts consisted of 5 exercises: shoulder press, chest press, leg press, low row, and lat pull down. The SRT group completed 1 set of each exercise at 50% 1RM until momentary failure with a 10-second concentric and a 10-second eccentric phase. The TRT group completed 3 sets of 8 repetitions at 80% 1RM for each exercise, with 4 seconds of contraction time for each repetition. Groups were statistically similar at baseline. There was a significant (p ≤ 0.01) time main effect for flexibility with the greatest improvements occurring for the training groups (SRT 14.7% and TRT 11%). All strength tests had significant (p ≤ 0.01) time main effects but no group or group by time interactions. Both training groups had large percent improvements in strength compared to CON, but the large variability associated with the SRT group resulted in only the TRT group being significantly different from the CON group. In conclusion, percent improvements were similar for the TRT and SRT groups, but only the TRT group reached statistical significance for the strength improvements, and both groups were equally effective for improving flexibility.

  13. Precipitation, strength and work hardening of age hardened aluminium alloys

    NASA Astrophysics Data System (ADS)

    Ryen, Ø.; Holmedal, B.; Marthinsen, K.; Furu, T.

    2015-08-01

    The strength and work hardening of age hardened AA6063 and AA6082 alloys have been investigated in terms of a detailed characterization of precipitate and dislocation structures obtained by TEM and SEM. Tensile and compression tests were performed at as quenched, peak aged and severely aged conditions. A strong work hardening in the as quenched condition was found, similar to AlMg alloys with twice as much alloying elements in solid solution. It was found that the initial work hardening rate and the critical failure strain are both smallest at the peak aged condition. During large deformations the needle-shaped precipitates are sheared uniformly by dislocations altering their <001> orientations, which indicates extensive cross slip. In the overaged condition the early initial work hardening is larger than at the peak aged condition, but followed by a weak linear work hardening, apparently directly entering stage IV at a low strain. Cracked, needle-shaped precipitates were seen at larger strains.

  14. High Strength, Weldable Precipitation Aged Steels

    NASA Astrophysics Data System (ADS)

    Wilson, Alexander D.

    1987-03-01

    The family of plate steels represented by ASTM Specification A7101 is finding increasing applications. These low carbon, Cu-Ni-Cr-Mo-Cb, copper precipitation hardened steels have been identified by a number of designations over the years. During early development in the late 1960's and first commercial production in 1970, the steels were known as IN-787 (trademark of International Nickel Company).2 ASTM specifications were subsequently developed for structural (A710) and pressure vessel (A736) applications over ten years ago. More recent interest and application of this family of steels by the U.S. Navy has lead to development of a military specification MIL-S-24645 (SH),3 also initially known as "HSLA-80." Significant tonnage is being produced for the U.S. Navy as a replacement for HY80 (MIL-S-16216) in cruiser deck, bulkhead and hull applications.4 In these applications, the enhanced weldability and requirement of no preheat at this high strength and toughness level has been the main motivation for its use. Over the past 15 years, A710 type steels have also been used in a variety of applications, including off-shore platforms, pressure vessels, arctic linepipe valves and off-highway mining truck frames.

  15. Leg Strength Comparison between Younger and Middle-age Adults

    PubMed Central

    Kim, Sukwon; Lockhart, Thurmon; Nam, Chang S.

    2009-01-01

    Although a risk of occupational musculoskeletal diseases has been identified with age-related strength degradation, strength measures from working group are somewhat sparse. This is especially true for the lower extremity strength measures in dynamic conditions (i.e., isokinetic). The objective of this study was to quantify the lower extremity muscle strength characteristics of three age groups (young, middle, and the elderly). Total of 42 subjects participated in the study: 14 subjects for each age group. A commercial dynamometer was used to evaluate isokinetic and isometric strength at ankle and knee joints. 2 × 2 (Age group (younger, middle-age, and older adult groups) × Gender (male and female)) between-subject design and Post-hoc analysis were performed to evaluate strength differences among three age groups. Post-hoc analysis indicated that, overall, middle-age workers’ leg strengths (i.e. ankle and knee muscles) were significantly different from younger adults while middle-age workers’ leg strengths were virtually identical to older adults’ leg strengths. These results suggested that, overall, 14 middle-age workers in the present study could be at a higher risk of musculoskeletal injuries. Future studies looking at the likelihood of musculoskeletal injuries at different work places and from different working postures at various age levels should be required to validate the current findings. The future study would be a valuable asset in finding intervention strategies such that middle-age workers could stay healthier longer. PMID:20436934

  16. Leg Strength Comparison between Younger and Middle-age Adults.

    PubMed

    Kim, Sukwon; Lockhart, Thurmon; Nam, Chang S

    2010-05-01

    Although a risk of occupational musculoskeletal diseases has been identified with age-related strength degradation, strength measures from working group are somewhat sparse. This is especially true for the lower extremity strength measures in dynamic conditions (i.e., isokinetic). The objective of this study was to quantify the lower extremity muscle strength characteristics of three age groups (young, middle, and the elderly). Total of 42 subjects participated in the study: 14 subjects for each age group. A commercial dynamometer was used to evaluate isokinetic and isometric strength at ankle and knee joints. 2 × 2 (Age group (younger, middle-age, and older adult groups) × Gender (male and female)) between-subject design and Post-hoc analysis were performed to evaluate strength differences among three age groups. Post-hoc analysis indicated that, overall, middle-age workers' leg strengths (i.e. ankle and knee muscles) were significantly different from younger adults while middle-age workers' leg strengths were virtually identical to older adults' leg strengths. These results suggested that, overall, 14 middle-age workers in the present study could be at a higher risk of musculoskeletal injuries. Future studies looking at the likelihood of musculoskeletal injuries at different work places and from different working postures at various age levels should be required to validate the current findings. The future study would be a valuable asset in finding intervention strategies such that middle-age workers could stay healthier longer.

  17. Early Children's Literature and Aging

    ERIC Educational Resources Information Center

    McGuire, Sandra L.

    2016-01-01

    Increased longevity is a worldwide phenomenon placing emphasis on the need for preparation for life's later years. Today's children will be the older adults of tomorrow. A resource that can help to educate them about aging and prepare them for the long life ahead is early children's literature (Preschool-Primary). This literature can provide…

  18. Uniaxial Tension Test of Slender Reinforced Early Age Concrete Members

    PubMed Central

    Mimura, Yoichi; Yoshitake, Isamu; Zhang, Wenbo

    2011-01-01

    The present study aims to obtain the tensile properties of early age concrete based on a uniaxial tension test employing RC slender members. First, the paper shows that concrete strain is equal to the strain of rebar at the mid-span of the RC member. The tensile Young’s modulus and the strain capacity of early age concrete are estimated using strain measurements. The experiment indicated that the tensile Young’s modulus at an early age is higher than the compressive modulus. This observation was similar to one found in a previous investigation which used a direct tension test of early age concrete. Moreover, the paper describes how an empirical equation for mature concrete can be applied to the relation between uniaxial tensile strength and splitting tensile strength even in early age concrete. Based on a uniaxial tension test, the paper proposes an empirical equation for the relationship between standard bond stresses and relative slip. PMID:28824146

  19. Shoulder Strength Requirements for Upper Limb Functional Tasks: Do age and Rotator Cuff Tear Status Matter?

    PubMed

    Santago, Anthony C; Vidt, Meghan E; Li, Xiaotong; Tuohy, Christopher J; Poehling, Gary G; Freehill, Michael T; Saul, Katherine R

    2017-07-17

    Understanding upper limb strength requirements for daily tasks is imperative for early detection of strength loss that may progress to disability due to age or rotator cuff tear. We quantified shoulder strength requirements for five upper limb tasks performed by three groups: uninjured young adults and older adults, and older adults with a degenerative supraspinatus tear prior to repair. Musculoskeletal models were developed for each group representing age, sex, and tear-related strength losses. Percentage of available strength used was quantified for the subset of tasks requiring the largest amount of shoulder strength. Significant differences in strength requirements existed across tasks: upward reach 105° required the largest average strength; axilla wash required the largest peak strength. However, there were limited differences across participant groups. Older adults with and without a tear used a larger percentage of their shoulder elevation (p<.001, p<.001) and external rotation (p<.001, p=.017) strength than the young adults respectively. Presence of a tear signficantly increased percentage of internal rotation strength compared to young (p<.001) and uninjured older adults (p=.008). Marked differences in strength demand across tasks indicate the need for evaluating a diversity of functional tasks to effectively detect early strength loss which may lead to disability.

  20. Improvement of Early Strength of Cement Mortar Containing Granulated Blast Furnace Slag Using Industrial Byproducts

    PubMed Central

    Kim, Jin-Hyoung; Lee, Han-Seung

    2017-01-01

    In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6–104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO3 was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite. PMID:28880256

  1. Improvement of Early Strength of Cement Mortar Containing Granulated Blast Furnace Slag Using Industrial Byproducts.

    PubMed

    Kim, Jin-Hyoung; Lee, Han-Seung

    2017-09-07

    In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6-104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO₃ was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite.

  2. Personality strengths in adolescence and decreased risk of developing mental health problems in early adulthood.

    PubMed

    Bromley, Elizabeth; Johnson, Jeffrey G; Cohen, Patricia

    2006-01-01

    The aim of this study was to investigate whether personality strengths during adolescence are associated with decreased risk of developing psychiatric disorders, educational or occupational problems, violent or criminal behaviors, and interpersonal difficulties during early adulthood. A representative community sample of 688 mothers from upstate New York and their offspring was interviewed in the period of 1985-1986 (mean offspring age = 16 years) and in that of 1991-1993 (mean offspring age = 22 years). Results showed that youths with numerous personality strengths at the mean age of 16 years were at a decreased risk of developing psychiatric disorders, educational and occupational problems, interpersonal difficulties, and criminal behaviors at the mean age of 22 years. These associations remained significant after controlling for age, sex, socioeconomic status, verbal intelligence, preexisting psychiatric disorders, and corresponding problems at the mean age of 16 years. Although youths with fewer personality strengths who experienced numerous stressful events were at elevated risk of developing psychiatric disorders during early adulthood, those with a higher number of personality strengths at the mean age of 16 years did not share this vulnerability. We conclude that personality strengths during adolescence may contribute to a decreased risk of developing a wide range of adverse outcomes during early adulthood. Systematic evaluation of character strengths may improve the clinical assessment of adolescents.

  3. Sex differences in soleus strength may predispose middle age women to falls.

    PubMed

    Chimera, Nicole J; Manal, Kurt T

    2013-09-01

    This study investigated middle age healthy adults to elucidate if plantar flexion (PF) strength differences exist because of the triceps surae or the soleus when comparing between sexes. A random population sample was stratified by sex and included 25 healthy (12 women and 13 men) subjects who volunteered for participation. Dorsiflexion range of motion was measured using a biplane goniometer. Self-reported function was assessed using the Foot and Ankle Ability Measure. Ankle PF strength was assessed using the Biodex System 3. To determine triceps surae vs. soleus strength, testing positions included (1) full ankle dorsiflexion with the knee in full extension and (2) full ankle dorsiflexion with 90° of knee flexion. Results indicated that women were significantly weaker than men in absolute PF strength for both triceps surae and soleus testing positions. Furthermore, even with normalizing PF strength to body mass PF strength deficits persisted. Additionally, when the contribution of the soleus was accounted for in the full knee extended position (triceps surae), normalized strength differences no longer existed between sexes. Therefore, these results indicate that what appeared as triceps surae complex strength deficits in middle age women compared with men was actually soleus weakness. This may suggest that middle age women are predisposed to increased falls at an early age than previously reported. Additionally, this may indicate that the soleus muscle should be a focus of strength training for women during middle age.

  4. A new test method for young age strength of shotcrete

    SciTech Connect

    Teramoto, Shozo

    1995-12-31

    As a method for testing the young-age strength of shotcrete used as tunnel supports, use of the Parotester, which is designed to measure the hardness of paper rolls at printing factories, has been considered. This paper reports the results of laboratory tests conducted to establish this method as a means of strength testing.

  5. Women's Strength Training. Lifting the Limits of Aging?

    ERIC Educational Resources Information Center

    Cinque, Chris

    1990-01-01

    Strength training is considered a male activity, but physicians are recommending it to women who want to keep their musculoskeletal systems strong and flexible as they age. This article discusses goals and problems of strength training for women and suggests it as an adjunct to cardiovascular fitness exercises. (SM)

  6. Early reduction in toe flexor strength is associated with physical activity in elderly men

    PubMed Central

    Suwa, Masataka; Imoto, Takayuki; Kida, Akira; Yokochi, Takashi

    2016-01-01

    [Purpose] To compare the toe flexor, hand grip and knee extensor strengths of young and elderly men, and to examine the association between toe flexor strength and physical activity or inactivity levels. [Subjects and Methods] Young (n=155, 18–23 years) and elderly (n=60, 65–88 years) men participated in this study. Toe flexor, hand grip, and knee extensor strength were measured. Physical activity (time spent standing/walking per day) and inactivity (time spent sitting per day) were assessed using a self-administered questionnaire. [Results] Toe flexor, hand grip, and knee extensor strength of the elderly men were significantly lower than those of the young men. Standing/walking and sitting times of the elderly men were lower than those of the young men. Toe flexor strength correlated with hand grip and knee extensor strength in both groups. In elderly men, toe flexor strength correlated with standing/walking time. In comparison to the young men’s mean values, toe flexor strength was significantly lower than knee extensor and hand grip strength in the elderly group. [Conclusion] The results suggest that age-related reduction in toe flexor strength is greater than those of hand grip and knee extensor strengths. An early loss of toe flexor strength is likely associated with reduced physical activity in elderly men. PMID:27313353

  7. Implementing Paraprofessional Strength-Based Early Intervention Home Visitations

    ERIC Educational Resources Information Center

    Mykota, David B.

    2008-01-01

    The purpose of the present study is to evaluate the implementation process for Parenting Plus, an early intervention program in a rural, western Canadian health district. Parenting Plus, as modeled after Hawaii Healthy Start, provides strength-based paraprofessional home visitations to overburdened parents of newborns. The general inductive…

  8. Implementing Paraprofessional Strength-Based Early Intervention Home Visitations

    ERIC Educational Resources Information Center

    Mykota, David B.

    2008-01-01

    The purpose of the present study is to evaluate the implementation process for Parenting Plus, an early intervention program in a rural, western Canadian health district. Parenting Plus, as modeled after Hawaii Healthy Start, provides strength-based paraprofessional home visitations to overburdened parents of newborns. The general inductive…

  9. Age-related reduction and independent predictors of toe flexor strength in middle-aged men.

    PubMed

    Suwa, Masataka; Imoto, Takayuki; Kida, Akira; Iwase, Mitsunori; Yokochi, Takashi

    2017-01-01

    Toe flexor muscles play an important role in posture and locomotion, and poor toe flexor strength is a risk factor for falls. In this cross-sectional study, we estimated the age-related change in toe flexor strength and compared it with that of handgrip strength. Independent factors predicting toe flexor and handgrip strength were also determined. A total of 1401 male (aged 35-59 years) study participants were divided into five groups according to their chronological age; 35-39, 40-44, 45-49, 50-54, and 55-59 years. Toe flexor and handgrip strength, anthropometry, and resting blood pressure were measured. Fasting blood samples were collected to measure blood glucose, triglycerides, high- and low-density lipoprotein-cholesterols, and albumin. A self-administered lifestyle questionnaire was conducted. Decline in absolute toe flexor and handgrip strength began in the age groups 50-55 and 55-59 years, respectively. In comparison to the mean values of the youngest group, relative toe flexor strength (87.0 ± 26.6%) was significantly lower than handgrip strength (94.4 ± 13.1%) for the oldest group. Multiple regression analyses showed that independent factors predicting both toe flexor and handgrip strength were lean body mass, age, serum albumin, drinking habit, and fat mass. Additionally, fasting blood glucose, diastolic blood pressure, sleeping time and exercise habit were predicting factors of toe flexor strength but not of handgrip strength. Age-related reduction in toe flexor strength was earlier and greater than handgrip strength, and toe flexor strength reflects body composition and metabolic status.

  10. Standardized grip strength as an outcome measure in early rheumatoid arthritis.

    PubMed

    Sheehy, C; Gaffney, K; Mukhtyar, C

    2013-01-01

    Patients with rheumatoid arthritis (RA) suffer progressive loss of hand function and have weaker hand grip than the healthy population. In this study we aimed to validate hand grip strength standardized by age and gender (z score) against currently accepted clinical measures of disease activity. Electronic records of patients with a diagnosis of RA seen between April 2007 and December 2011 were screened for the documentation of tender and swollen joint counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), along with patient global activity score and grip strength. Bilateral grip strengths were converted to z scores on the basis of previously published age- and gender-corrected normative data for grip strength. The z scores were then correlated against components of disease activity scores. Ninety patients diagnosed with RA had been seen 602 times within 2 years of diagnosis. Hand grip data were available for 204 visits. There was a statistically significant inverse correlation between grip strength z scores and the tested variables. The sensitivity and specificity of a hand grip z score of -1.5 for predicting remission were, respectively, 70% and 76% for the right hand and 82% and 69% for the left hand. Hand grip testing and subsequent conversion to z scores corrected for age and gender correlate with disease activity in early RA. We have shown that the grip strength z scores can discriminate between various disease states, and the strength seems to return to near normative data when the disease is in remission.

  11. Effects of strength training on osteogenic differentiation and bone strength in aging female Wistar rats

    PubMed Central

    Singulani, Monique Patricio; Stringhetta-Garcia, Camila Tami; Santos, Leandro Figueiredo; Morais, Samuel Rodrigues Lourenço; Louzada, Mário Jefferson Quirino; Oliveira, Sandra Helena Penha; Chaves Neto, Antonio Hernandes; Dornelles, Rita Cássia Menegati

    2017-01-01

    The effects of strength training (ST) on the mechanical bone strength and osteogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs) from adult, aged and exercised aged rats were determined. The exercised aged animals displayed higher values of areal bone mineral density, compression test, alkaline phosphatase activity (ALP) and biological mineralization, while oil red O staining for adipocytes was lower. ST increased gene expression of runt-related transcription factor 2 (Runx2), osterix (Osx) as well as bone matrix protein expression, and reduced expression of peroxisome proliferator-activated receptor gamma (Pparγ). The production of pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) was lower in BMSCs of the aged exercised group. The ST practice was able to improve the bone mechanical properties in aged female rats, increasing the potential for osteogenic differentiation of BMSCs, reducing the adipogenic differentiation and pro-inflammatory cytokine level. In summary, the data achieved in this study showed that strength training triggers physiological responses that result in changes in the bone microenvironment and bring benefits to biomechanical parameters of bone tissue, which could reduce the risk of fractures during senescent. PMID:28211481

  12. Effects of strength training on osteogenic differentiation and bone strength in aging female Wistar rats.

    PubMed

    Singulani, Monique Patricio; Stringhetta-Garcia, Camila Tami; Santos, Leandro Figueiredo; Morais, Samuel Rodrigues Lourenço; Louzada, Mário Jefferson Quirino; Oliveira, Sandra Helena Penha; Chaves Neto, Antonio Hernandes; Dornelles, Rita Cássia Menegati

    2017-02-17

    The effects of strength training (ST) on the mechanical bone strength and osteogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs) from adult, aged and exercised aged rats were determined. The exercised aged animals displayed higher values of areal bone mineral density, compression test, alkaline phosphatase activity (ALP) and biological mineralization, while oil red O staining for adipocytes was lower. ST increased gene expression of runt-related transcription factor 2 (Runx2), osterix (Osx) as well as bone matrix protein expression, and reduced expression of peroxisome proliferator-activated receptor gamma (Pparγ). The production of pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) was lower in BMSCs of the aged exercised group. The ST practice was able to improve the bone mechanical properties in aged female rats, increasing the potential for osteogenic differentiation of BMSCs, reducing the adipogenic differentiation and pro-inflammatory cytokine level. In summary, the data achieved in this study showed that strength training triggers physiological responses that result in changes in the bone microenvironment and bring benefits to biomechanical parameters of bone tissue, which could reduce the risk of fractures during senescent.

  13. [Association of muscle strength with early markers of cardiovascular risk in sedentary adults].

    PubMed

    Triana-Reina, Héctor Reynaldo; Ramírez-Vélez, Robinson

    2013-10-01

    To assess the association between muscle strength and early cardiovascular risk (CVR) markers in sedentary adults. A total of 176 sedentary subjects aged 18-30 years were enrolled. Body mass index and fat percentage were calculated, and waist circumference, grip strength by dynamometry, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and maximal oxygen uptake by VO2max were measured as CVR markers. A multivariate logistic regression analysis was used to assess associations between muscle strength and CVR markers. Inverse correlations were found between muscle strength and adiposity (r=-.317; P=.001), waist circumference (r=-.309; P=.001), systolic blood pressure (r=-.401; P=.001), and mean arterial pressure (r=-.256; P=.001). Subjects with lower levels of muscle strength had a 5.79-fold (95% CI 1.57 to 9.34; P=.008) risk of having higher adiposity levels (≥25%) and a 9.67-fold (95% CI=3.86 to 19.22; P<.001) risk of having lower physical capacity values for VO2max (≤31.5mL/kg/min(-1)). In sedentary adults, muscle strength is associated to early manifestations of CVR. It is suggested that muscle strength testing is added to routine measurement of VO2max and traditional risk factors for prevention and treatment of cardiovascular risk. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

  14. Time since onset of walking predicts tibial bone strength in early childhood.

    PubMed

    Ireland, Alex; Rittweger, Jörn; Schönau, Eckhard; Lamberg-Allardt, Christel; Viljakainen, Heli

    2014-11-01

    Bone strength in adulthood is known to be affected by health at birth and early childhood. Habitual bone loading is a primary determinant of bone strength in later childhood and adulthood. However, the effects of physical activity in early childhood (e.g. crawling, standing and walking) on bone strength are unknown. Fifty-three children (twenty-seven males) were included in a longitudinal study in their early infancy. Shortly after birth (0.3±0.3months), details of mass and height were obtained along with a pQCT scan at 20% distal-proximal tibia length. At 14.8±0.5months of age the same data were collected, along with details of age at onset of standing, crawling, supported and unsupported walking. Time since onset of walking unsupported was associated with greater bone mass, cortical bone area, pericortical circumference and polar moment of inertia of both total and cortical bone (all P<0.05). There were no significant associations between other physical activity timepoints and bone measures. Age at onset of walking was not significantly related to mass, length or bone measures at birth. The results suggest that time since attainment of independent walking - representing exposure of the tibia to the large reaction and muscular forces associated with locomotion - is a primary determinant of bone strength in early childhood. This finding raises the possible opportunity of physical activity interventions at young age in paediatric populations associated with low childhood bone strength and late walking (e.g. low birth weight, cerebral palsy and Down's Syndrome, etc.).

  15. Lattice Modeling of Early-Age Behavior of Structural Concrete

    PubMed Central

    Pan, Yaming; Prado, Armando; Porras, Rocío; Hafez, Omar M.; Bolander, John E.

    2017-01-01

    The susceptibility of structural concrete to early-age cracking depends on material composition, methods of processing, structural boundary conditions, and a variety of environmental factors. Computational modeling offers a means for identifying primary factors and strategies for reducing cracking potential. Herein, lattice models are shown to be adept at simulating the thermal-hygral-mechanical phenomena that influence early-age cracking. In particular, this paper presents a lattice-based approach that utilizes a model of cementitious materials hydration to control the development of concrete properties, including stiffness, strength, and creep resistance. The approach is validated and used to simulate early-age cracking in concrete bridge decks. Structural configuration plays a key role in determining the magnitude and distribution of stresses caused by volume instabilities of the concrete material. Under restrained conditions, both thermal and hygral effects are found to be primary contributors to cracking potential. PMID:28772590

  16. Early age renal synovial sarcoma.

    PubMed

    Romero-Rojas, Alfredo Ernesto; Díaz-Pérez, Julio Alexander; Messa-Botero, Oscar Alberto; Neira-Mejia, Fabían Enrique

    2010-01-01

    We report a primary renal Synovial Sarcoma (SS) case and analyze its features. A 15 year old male presented with left abdominal mass and weight loss. CT scan images showed a 13 cm mass located in the lower pole of the left kidney. Renal biopsy recognized an undifferentiated neoplasm, the immunohistochemistry suggesting the probability of neuroectodermic primitive tumor versus SS. Chemotherapy and radical nephrectomy were carried out. Pathological study showed a big multilobulated necrotic tumor 22 x 13 x 12.5 cm. Histopathological study demonstrated a neoplasm composed by immature cells. Currently, patient has survived 1,8 years. A structured bibliographical search was performed in the Medline, Imbiomed and Scielo databases. The final immunohistochemistry studies gave the diagnosis of poorly differentiated renal SS small cell variety. The renal SS is extremely infrequent, with less than 40 cases reported, of which this case reports the earlier age. These tumors, when located in the kidney, represent a great diagnostic challenge that requires adequate clinical, radiological, surgical, and pathological correlation for appropriate diagnosis and treatment.

  17. Age at spinal cord injury determines muscle strength

    PubMed Central

    Thomas, Christine K.; Grumbles, Robert M.

    2014-01-01

    As individuals with spinal cord injury (SCI) age they report noticeable deficits in muscle strength, endurance and functional capacity when performing everyday tasks. These changes begin at ~45 years. Here we present a cross-sectional analysis of paralyzed thenar muscle and motor unit contractile properties in two datasets obtained from different subjects who sustained a cervical SCI at different ages (≤46 years) in relation to data from uninjured age-matched individuals. First, completely paralyzed thenar muscles were weaker when C6 SCI occurred at an older age. Muscles were also significantly weaker if the injury was closer to the thenar motor pools (C6 vs. C4). More muscles were strong (>50% uninjured) in those injured at a younger (≤25 years) vs. young age (>25 years), irrespective of SCI level. There was a reduction in motor unit numbers in all muscles tested. In each C6 SCI, only ~30 units survived vs. 144 units in uninjured subjects. Since intact axons only sprout 4–6 fold, the limits for muscle reinnervation have largely been met in these young individuals. Thus, any further reduction in motor unit numbers with time after these injuries will likely result in chronic denervation, and may explain the late-onset muscle weakness routinely described by people with SCI. In a second dataset, paralyzed thenar motor units were more fatigable than uninjured units. This gap widened with age and will reduce functional reserve. Force declines were not due to electromyographic decrements in either group so the site of failure was beyond excitation of the muscle membrane. Together, these results suggest that age at SCI is an important determinant of long-term muscle strength, and fatigability, both of which influence functional capacity. PMID:24478643

  18. Successful Aging: Early Influences and Contemporary Characteristics

    ERIC Educational Resources Information Center

    Pruchno, Rachel A.; Wilson-Genderson, Maureen; Rose, Miriam; Cartwright, Francine

    2010-01-01

    Purpose: Positing that successful aging has independent, yet related, dimensions that are both objective and subjective, we examine how early influences and contemporary characteristics define 4 groups of people. Design and Methods: Data were gathered from 5,688 persons aged 50-74 years living in New Jersey who participated in telephone…

  19. Successful Aging: Early Influences and Contemporary Characteristics

    ERIC Educational Resources Information Center

    Pruchno, Rachel A.; Wilson-Genderson, Maureen; Rose, Miriam; Cartwright, Francine

    2010-01-01

    Purpose: Positing that successful aging has independent, yet related, dimensions that are both objective and subjective, we examine how early influences and contemporary characteristics define 4 groups of people. Design and Methods: Data were gathered from 5,688 persons aged 50-74 years living in New Jersey who participated in telephone…

  20. Age and muscle strength mediate the age-related biomechanical plasticity of gait.

    PubMed

    Hortobágyi, Tibor; Rider, Patrick; Gruber, Allison H; DeVita, Paul

    2016-04-01

    Old compared with young adults walk with reduced ankle and increased hip mechanical output. We examined the idea that age, leg strength, or both are related to the age-related changes in mechanical output during gait. Healthy young (n = 32, age 21.5 years) and old adults (n = 32, age 76.8 years) participated in biomechanical gait analyses at 1.5 m/s and were also measured for maximal leg strength. Analysis 1 confirmed previous data as old compared with young adults walked with 50 % more hip positive work and 18 % less ankle positive work. Analysis 2 showed that leg strength did not affect gait kinetics in groups of subjects with similar ages. In a weak young and a strong old group, Analysis 3 showed that old adults still walked with 23 % greater hip positive work. The group by joint interaction in Analysis 4 was suggestive of an even greater reliance on hip and less reliance on ankle work in weak compared with strong old adults. Age and leg strength both contribute to the age-related changes in mechanical output during gait. Exercise prescription, normally targeting the knee extensors, should also involve ankle and hip muscles.

  1. Correlation of flexural strength of coupons versus strength of crowns fabricated with different zirconia materials with and without aging.

    PubMed

    Alghazzawi, Tariq F; Janowski, Gregg M

    2015-12-01

    The purpose of this study was to determine the presence of a correlation between flexural strength and simulated crown strength; a correlation between crown strength and mode of fracture; an effect of aging on the flexural strength; and an effect of aging on the crown strength. Two hundred forty zirconia specimens were fabricated with 2 different designs, fully contoured crown shape specimens (n = 120) and rectangular coupons (n = 120), to provide 10 specimens each of 6 brands of zirconia (Lava Plus High Translucency [3M ESPE], Argen HT [Argen Corp], Zirlux [Ardent], BruxZir [Glidewell Laboratories], ZenoStar [Wieland Dental], and DDBioZX(2) [Dental Direkt]). One-half of each sample type was given a severe, simulated low-temperature aging treatment. The coupons were tested by 3-point flexural strength, and crowns were tested after luting to metallic abutments using resin cement. Statistical significance was evaluated by 2-factor analysis of variance (P = .05). Aging increased the mean (standard deviation [SD]) flexural strength for the following groups: Argen HT (995 [140] megapascals versus 677 [121] MPa before aging), Zirlux (939 [101] MPa versus 826 [169] MPa before aging), and ZenoStar (954 [81] MPa versus 764 [77] MPa before aging). There were statistical differences for the mean (SD) crown strengths for the following aged crowns: DDBioZX(2) had higher magnitudes (9,755 [1,095] MPa) than ZenoStar (8,864 [976] MPa), whereas Lava Plus High Translucency crowns had higher magnitudes (9,871 [942] MPa) than ZenoStar (8,864 [976] MPa). There was no effect of aging on the crown strength. There were statistical differences in the mode of fracture for the zirconia crowns between the following groups: nonaged and aged BruxZir (P = .014), nonaged and aged ZenoStar (P = .0226), and nonaged and aged Lava Plus High Translucency (P < .0001). There was no correlation between flexural strength and crown strength. There was no direct correlation between ranking of flexural

  2. Early nutrition and ageing: can we intervene?

    PubMed

    Duque-Guimarães, Daniella; Ozanne, Susan

    2017-03-29

    Ageing, a complex process that results in progressive decline in intrinsic physiological function leading to an increase in mortality rate, has been shown to be affected by early life nutrition. Accumulating data from animal and epidemiological studies indicate that exposure to a suboptimal nutritional environment during fetal life can have long-term effects on adult health. In this paper, we discuss the impact of early life nutrition on the development of age-associated diseases and life span. Special emphasis is given to studies that have investigated the molecular mechanisms underlying these effects. These include permanent structural and cellular changes including epigenetics modifications, oxidative stress, DNA damage and telomere shortening. Potential strategies targeting these mechanisms, in order to prevent or alleviate the detrimental effects of suboptimal early nutrition on lifespan and age-related diseases, are also discussed. Although recent reports have already identified effective therapeutic interventions, such as antioxidant supplementation, further understanding of the extent and nature of how early nutrition influences the ageing process will enable the development of novel and more effective approaches to improve health and extend human lifespan in the future.

  3. Mobile Learning and Early Age Mathematics

    ERIC Educational Resources Information Center

    Peled, Shir; Schocken, Shimon

    2014-01-01

    The ability to develop engaging simulations and constructive learning experiences using mobile devices is unprecedented, presenting a disruption in educational practices of historical proportions. In this paper we describe some of the unique virtues that mobile learning hold for early age mathematics education. In particular, we describe how…

  4. Age-Related Differences in Muscular Strength and Muscular Endurance among Female Masters Swimmers.

    ERIC Educational Resources Information Center

    Dummer, Gail M.; And Others

    1985-01-01

    This study investigated age-related differences in muscular strength and muscular endurance among 73 female masters swimmers aged 24 to 71 years. While an age-related decline in muscular strength was apparent, the results failed to reveal a similar trend for endurance, suggesting that swimming influences endurance more than strength among women.…

  5. Age-Related Differences in Muscular Strength and Muscular Endurance among Female Masters Swimmers.

    ERIC Educational Resources Information Center

    Dummer, Gail M.; And Others

    1985-01-01

    This study investigated age-related differences in muscular strength and muscular endurance among 73 female masters swimmers aged 24 to 71 years. While an age-related decline in muscular strength was apparent, the results failed to reveal a similar trend for endurance, suggesting that swimming influences endurance more than strength among women.…

  6. Normative data for hand grip strength and key pinch strength, stratified by age and gender for a multiethnic Asian population.

    PubMed

    Lam, Ngee Wei; Goh, Hui Ting; Kamaruzzaman, Shahrul Bahyah; Chin, Ai-Vyrn; Poi, Philip Jun Hua; Tan, Maw Pin

    2016-10-01

    Hand strength is a good indicator of physical fitness and frailty among the elderly. However, there are no published hand strength references for Malaysians aged > 65 years. This study aimed to establish normative data for hand grip strength (HGS) and key pinch strength (KPS) for Malaysians aged ≥ 60 years, and explore the relationship between hand strength and physical ability. Healthy participants aged ≥ 60 years with no neurological conditions were recruited from rural and urban locations in Malaysia. HGS and KPS were measured using hand grip and key pinch dynamometers. Basic demographic data, anthropometric measures, modified Barthel Index scores and results of the Functional Reach Test (FRT), Timed Up and Go (TUG) test and Jebsen-Taylor Hand Function Test (JTHFT) were recorded. 362 subjects aged 60-93 years were recruited. The men were significantly stronger than the women in both HGS and KPS (p < 0.001). The hand strength of the study cohort was lower than that of elderly Western populations. Significant correlations were observed between hand strength, and residential area (p < 0.001), FRT (r = 0.236, p = 0.028), TUG (r = -0.227, p = 0.009) and JTHFT (r = -0.927, p < 0.001). This study established reference ranges for the HGS and KPS of rural and urban elderly Malaysian subpopulations. These will aid the use of hand strength as a screening tool for frailty among elderly persons in Malaysia. Future studies are required to determine the modifiable factors for poor hand strength.

  7. Martensitic transformations in high-strength steels at aging

    NASA Astrophysics Data System (ADS)

    Berezovskaya, V. V.; Bannykh, O. A.

    2011-04-01

    The effect of heat treatment and elastic stresses on the texture of maraging NiTi-steels is studied. The interruption of the decomposition of martensite at the early stages is shown to be accompanied by the γ → α transformation, which proceeds upon cooling from the aging temperature and under elastic (σ < σ0.2) tensile stresses. The martensite has a crystallographic texture, which is caused by the evolution of hot-deformation texture as a result of quenching and decomposition of a supersaturated α solid solution.

  8. Magnetic field strength, water and life on the early Earth

    NASA Astrophysics Data System (ADS)

    Tarduno, J. A.; Cottrell, R. D.; Van Kranendonk, M. J.

    2011-12-01

    The early geomagnetic field shielded Earth from intense solar winds from the rapidly rotating young Sun. Therefore, the onset and strength of the earliest field are of prime interest for understanding evolution of the planet. Recent paleomagnetic investigations of Archean single silicate crystals hosting minute magnetic inclusions from the Kaapvaal craton, using highly sensitive SQUID magnetometers and CO2 laser demagnetization, have allowed definition of geomagnetic field intensities at 3.2, 3.4 and 3.45 Ga. Here we extend this time line to 3.47 Ga through the study of single silicate crystals from granitic rocks that are subvolcanic feeders to the Duffer Formation of the Pilbara craton. Preliminary paleointensity data are consistent with the presence of a geomagnetic field, supporting prior paleointensity results from the Kaapvaal craton that indicate a protective magnetic field was present when some of the first physical evidence for life has been reported. However, the new measured field intensities are only 25% of the modern value. These magnetic paleofield results suggest that the magnetopause was much closer to Earth during Paleoarchean times. The decreased standoff of the solar wind, together with the higher frequency of coronal mass ejections, would have promoted loss of volatiles and water from the atmosphere. Efforts to further extend observations through the paleomagnetic study of Hadean minerals will be discussed.

  9. Cognitive aging and early neurophychological diagnostics.

    PubMed

    Jolies, J

    1999-03-01

    With aging, most cognitive functions decline, especially processes concerning memorizing, attention, concentration, organizing, planning and problem solving. Neuropsychology can make an important contribution in early and differential diagnostics. The borderline between normal and pathological cognitive aging is especially important in this respect. The neuropsychologist gains insight in medical, biological, psychological and social factors of the aging person. Has the profile of complaints and deficits a normal background or is a pathological process taking place? It is important to people who are unnecessarily worried about possible dementia. Neuropsychological assessment also provides information about a patient's disturbed and undisturbed cognitive functions, their personality and their way of coping with problems in every day's life. This is of major importance, because it provides information and possibilities for biological or psychological interventions. Because of the complexity of problems that may occur, it is necessary that the neuropsychologist is experienced and works in a multidisciplinary team in which neurological and psychiatric expertise is present.

  10. Micromechanical Modeling of Concrete at Early Age

    NASA Astrophysics Data System (ADS)

    Tuleubekov, Kairat

    The focus of this research is a micromechanical characterization of Portland cement concrete at early age (less than 28 days). Concrete's viscoelastic properties change significantly at early age due to solidification of its matrix component. Bazant's solidification theory models concrete as a material solidifying in time. This approach is generalized to a three-dimensional characterization of a composite material with a solidifying matrix and elastic inclusions. An integral constitutive relationship was obtained using a generalized correspondence principle and homogenization techniques for elastic composite materials. In light of this approach, effective creep properties of composite spherical assemblage with an aging matrix are obtained. In addition, the elastic Hashin-Monteiro model is generalized to account for the effect of the interfacial transition zone properties on concrete creep. An effective computational platform was developed to evaluate operator expressions in order to obtain relaxation and creep functions numerically. Through numerical examples, it is shown that triaxial generalization of Bazant's solidification model enables robust and computationally efficient prediction of creep deformations in Portland cement concrete.

  11. Normative data for hand grip strength and key pinch strength, stratified by age and gender for a multiethnic Asian population

    PubMed Central

    Lam, Ngee Wei; Goh, Hui Ting; Kamaruzzaman, Shahrul Bahyah; Chin, Ai-Vyrn; Poi, Philip Jun Hua; Tan, Maw Pin

    2016-01-01

    INTRODUCTION Hand strength is a good indicator of physical fitness and frailty among the elderly. However, there are no published hand strength references for Malaysians aged > 65 years. This study aimed to establish normative data for hand grip strength (HGS) and key pinch strength (KPS) for Malaysians aged ≥ 60 years, and explore the relationship between hand strength and physical ability. METHODS Healthy participants aged ≥ 60 years with no neurological conditions were recruited from rural and urban locations in Malaysia. HGS and KPS were measured using hand grip and key pinch dynamometers. Basic demographic data, anthropometric measures, modified Barthel Index scores and results of the Functional Reach Test (FRT), Timed Up and Go (TUG) test and Jebsen-Taylor Hand Function Test (JTHFT) were recorded. RESULTS 362 subjects aged 60–93 years were recruited. The men were significantly stronger than the women in both HGS and KPS (p < 0.001). The hand strength of the study cohort was lower than that of elderly Western populations. Significant correlations were observed between hand strength, and residential area (p < 0.001), FRT (r = 0.236, p = 0.028), TUG (r = −0.227, p = 0.009) and JTHFT (r = −0.927, p < 0.001). CONCLUSION This study established reference ranges for the HGS and KPS of rural and urban elderly Malaysian subpopulations. These will aid the use of hand strength as a screening tool for frailty among elderly persons in Malaysia. Future studies are required to determine the modifiable factors for poor hand strength. PMID:26768064

  12. Lithospheric strength of Ganymede: Clues to early thermal profiles from extensional tectonic features

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Banerdt, W. B.

    1985-01-01

    While it is generally agreed that the strength of a planet's lithosphere is controlled by a combination of brittle sliding and ductile flow laws, predicting the geometry and initial characteristics of faults due to failure from stresses imposed on the lithospheric strength envelope has not been thoroughly explored. Researchers used lithospheric strength envelopes to analyze the extensional features found on Ganymede. This application provides a quantitative means of estimating early thermal profiles on Ganymede, thereby constraining its early thermal evolution.

  13. Age-Related and Sex-Related Differences in Hand and Pinch Grip Strength in Adults

    ERIC Educational Resources Information Center

    Puh, Urska

    2010-01-01

    The purpose of the study was to quantify age-related changes in hand grip strength and three types of pinch grip strength (key pinch, tip pinch, and palmar pinch) among male and female participants. The study included 199 healthy participants (100 females, 99 males) aged 20-79 years, who were divided into four age groups. The Baseline Hydraulic…

  14. Flexural strength and microhardness of anterior composites after accelerated aging

    PubMed Central

    Pala, Kanşad; Tuncer, Safa; Demirci, Mustafa; Öznurhan, Fatih; Serim, Merve

    2017-01-01

    Background This study aimed to evaluate the flexural strength and microhardness of three different anterior composites after 10 000 thermocycles. Material and Methods The mechanical properties of a nano-fill composite (Filtek Ultimate Universal Restorative (FUR) (Enamel)), a nano-hybrid composite (Clearfil Majesty ES2 (ES2) (Enamel)), and a micro-hybrid composite (G Aenial Anterior (GAA)) were investigated in this study. For the microhardness test, 8-mm diameter and 2-mm thickness composite discs were used (n = 10), and for the flexural strength test, 25x2x2 mm bar-shaped specimens were prepared (n = 13). The specimens were tested at 24 h and after 10 000 thermocycles. Data were analyzed using two-way analysis of variance and the post-hoc Tukey test (p < .05). Correlations between hardness and flexural strength were calculated using Pearson’s correlation analysis. Results There was a significant difference in the microhardness values of the materials (p < .05). FUR exhibited significantly higher microhardness than ES2 and GAA. However, the flexural strength of three composites was statistically similar at 24 h (p > .05). Pearson correlation analysis revealed that there was a negative relationship between the mean hardness and flexural strength values (correlation coefficient = -0.367, p = .043). After 10 000 thermocycles, microhardness values of each material and flexural strength of ES2 and GAA decreased significantly according to 24 h. Conclusions The nano-fill composite FUR displayed significantly higher microhardness values. However, each resin composite was statistically similar for flexural strength values. Ten thousand thermocycles significantly affected microhardness and flexural strength. Key words:Flexural strength, microhardness, anterior composites. PMID:28298986

  15. The SAURON project - XVIII. The integrated UV-line-strength relations of early-type galaxies

    NASA Astrophysics Data System (ADS)

    Bureau, Martin; Jeong, Hyunjin; Yi, Sukyoung K.; Schawinski, Kevin; Houghton, Ryan C. W.; Davies, Roger L.; Bacon, Roland; Cappellari, Michele; de Zeeuw, P. Tim; Emsellem, Eric; Falcón-Barroso, Jesús; Krajnović, Davor; Kuntschner, Harald; McDermid, Richard M.; Peletier, Reynier F.; Sarzi, Marc; Sohn, Young-Jong; Thomas, Daniel; van den Bosch, Remco C. E.; van de Ven, Glenn

    2011-07-01

    Using far-ultraviolet (FUV) and near-ultraviolet (NUV) photometry from guest investigator programmes on the Galaxy Evolution Explorer (GALEX) satellite, optical photometry from the MDM Observatory and optical integral-field spectroscopy from SAURON, we explore the UV-line-strength relations of the 48 nearby early-type galaxies in the SAURON sample. Identical apertures are used for all quantities, avoiding aperture mismatch. We show that galaxies with purely old stellar populations show well-defined correlations of the integrated FUV -V and FUV - NUV colours with the integrated Mg b and Hβ absorption line-strength indices, strongest for FUV - NUV. Correlations with the NUV -V colour, Fe5015 index and stellar velocity dispersion σ are much weaker. These correlations put stringent constraints on the origin of the UV-upturn phenomenon in early-type galaxies and highlight its dependence on age and metallicity. In particular, despite recent debate, we recover the negative correlation between FUV -V colour and Mg line strength originally publicized by Burstein et al., which we refer to as the 'Burstein relation', suggesting a positive dependence of the UV upturn on metallicity. We argue that the scatter in the correlations is real and present mild evidence that a strong UV excess is preferentially present in slow-rotating galaxies. We also demonstrate that most outliers in the correlations are galaxies with current or recent star formation, some at very low levels. We believe that this sensitivity to weak star formation, afforded by the deep and varied data available for the SAURON sample, explains why our results are occasionally at odds with other recent but shallower surveys. This is supported by the analysis of a large, carefully crafted sample of more distant early-type galaxies from the Sloan Digital Sky Survey (SDSS), more easily comparable with current and future large surveys.

  16. Early-phase adaptations to intrahospital training in strength and functional mobility of children with leukemia.

    PubMed

    San Juan, Alejandro F; Fleck, Steven J; Chamorro-Viña, Carolina; Maté-Muñoz, José L; Moral, Susana; García-Castro, Javier; Ramírez, Manuel; Madero, Luis; Lucia, Alejandro

    2007-02-01

    Improvements in chemotherapy and radiotherapy have contributed to the high survival rate (approximately 70%) of childhood acute lymphoblastic leukemia (ALL). However, during treatment, lack of physical activity and treatment cause various short- to long-term side effects, such as muscle atrophy and physical deconditioning. The purpose of this study was to determine the effects of an intrahospital, short-duration (8 weeks) exercise training program on muscle strength and endurance and functional mobility of children with ALL. Seven children (4 boys and 3 girls; 4-7 years of age) who were in the maintenance phase of treatment for ALL were selected as subjects. Three training sessions of 90- to 120-minute duration were performed each week. Each session included 11 different strength exercises engaging the major muscle groups and aerobic training. Gains in strength and endurance were assessed with a 6 repetition maximum test for upper (seated bench press and seated lateral row) and lower extremities (leg press). Gains in functional mobility were assessed with the time up and go test (TUG) and the timed up and down stairs test (TUDS). Performance was significantly improved after the training program in all strength tests (p < 0.01 for seated bench press and p < 0.05 for both seated lateral row and seated leg press) and in the TUG test (p < 0.05). In summary, a period of time as short as 8 weeks is enough to produce clinically relevant early-phase adaptations in children receiving treatment against ALL (i.e., improved functional mobility and muscle strength). Although more research is needed in the area of exercise training and pediatric cancer, exercise sciences can play a beneficial role in assisting both oncologists in treating cancer and improving children's quality of life during and after treatment.

  17. Effects of strength training on muscle strength characteristics, functional capabilities, and balance in middle-aged and older women.

    PubMed

    Holviala, Jarkko H S; Sallinen, Janne M; Kraemer, William J; Alen, Markku J; Häkkinen, Keijo K T

    2006-05-01

    Progressive strength training can lead to substantial increases in maximal strength and mass of trained muscles, even in older women and men, but little information is available about the effects of strength training on functional capabilities and balance. Thus, the effects of 21 weeks of heavy resistance training--including lower loads performed with high movement velocities--twice a week on isometric maximal force (ISOmax) and force-time curve (force produced in 500 milliseconds, F0-500) and dynamic 1 repetition maximum (1RM) strength of the leg extensors, 10-m walking time (10WALK) and dynamic balance test (DYN.D) were investigated in 26 middle-aged (MI; 52.8 +/- 2.4 years) and 22 older women (O; 63.8 +/- 3.8 years). 1RM, ISOmax, and F0-500 increased significantly in MI by 28 +/- 10%, 20 +/- 19%, 31 +/- 34%, and in O by 27 +/- 8%, 20 +/- 16%, 18 +/- 45%, respectively. 10WALK (MI and O, p < 0.001) shortened and DYN.D improved (MI and O, p < 0.001). The present strength-training protocol led to large increases in maximal and explosive strength characteristics of leg extensors and in walking speed, as well to an improvement in the present dynamic balance test performance in both age groups. Although training-induced increase in explosive strength is an important factor for aging women, there are other factors that contribute to improvements in dynamic balance capacity. This study indicates that total body heavy resistance training, including explosive dynamic training, may be applied in rehabilitation or preventive exercise protocols in aging women to improve dynamic balance capabilities.

  18. Age-associated changes in hand grip and quadriceps muscle strength ratios in healthy adults.

    PubMed

    Samuel, Dinesh; Wilson, Keely; Martin, Helen J; Allen, Robert; Sayer, Avan Aihie; Stokes, Maria

    2012-06-01

    Muscle strength may decline with age differentially in the upper and lower limbs. This information is difficult to capture through a single measure. The present study therefore aimed to characterize the relative changes in handgrip and lower limb muscle strength with aging by expressing them as a ratio. Thirty-eight healthy volunteers aged 20-82 years performed maximal voluntary contractions (MVC) of quadriceps and handgrip using a custom-built transducer and a Jamar dynamometer respectively. The grip-quadriceps ratios for young adults was similar in males and females (0.75); indicating knee extensor force exceeded grip force by approximately 25%. Ratios were increased in older adults (p=0.05), and strength of the two muscle groups was approximately equal (1.1). Pearson's correlation coefficients for grip against quadriceps strength were r=0.63 (young males), r=0.83 (young females), r=0.35 (older males) and r=0.05 (older females). The ratio used demonstrated clear differences between the age groups. The reduced muscle strength with increasing age was expected, but the higher grip/quadriceps strength ratios quantify a greater loss of quadriceps than grip strength with aging. It remains to be investigated whether the relatively greater rate of decline in quadriceps strength seen in healthy older people is more exaggerated in those who are frail, which would have implications for using grip strength as a physical marker of lower limb strength and function in those at risk of immobility and falls.

  19. Subjective age in early adolescence: relationships with chronological age, pubertal timing, desired age, and problem behaviors.

    PubMed

    Hubley, Anita M; Arım, Rübab G

    2012-04-01

    Subjective age generally refers to the age that one feels. In a cross-sectional questionnaire study of 245 adolescents ages 10-14 years, we examined (a) whether, and when, a cross-over in subjective age occurs, (b) differences in subjective age among pubertal timing groups, (c) correlations between subjective age and each of desired age and five problem behaviors, and (d) the relative contributions of chronological age, pubertal timing, desired age, and problem behaviors to subjective age in boys and girls. Adolescents generally reported subjective and desired ages that were slightly older than their chronological ages. A cross-over in subjective age occurred at 10.4 years. Late maturing adolescents reported relatively younger subjective ages than their early and on-time maturing peers. For boys, only desired age significantly predicted subjective age. For girls, an older desired age, late maturation, and higher scores on anxious/depressed feelings, rule-breaking behavior, and aggressive behavior significantly predicted older subjective ages. Copyright © 2011 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  20. Age and sex differences in estimated tibia strength: influence of measurement site.

    PubMed

    Sherk, Vanessa D; Bemben, Debra A

    2013-01-01

    Variability in peripheral quantitative computed tomography (pQCT) measurement sites and outcome variables limit direct comparisons of results between studies. Furthermore, it is unclear what estimates of bone strength are most indicative of changes due to aging, disease, or interventions. The purpose of this study was to examine age and sex differences in estimates of tibia strength. An additional purpose of this study was to determine which tibia site or sites are most sensitive for detecting age and sex differences in tibia strength. Self-identifying Caucasian men (n=55) and women (n=59) aged 20-59yr had their tibias measured with pQCT from 5% to 85% of limb length in 10% increments distal to proximal. Bone strength index, strength strain index (SSI), moments of inertia (Ip, Imax, and Imin), and strength-to-mass ratios (polar moment of inertia to total bone mineral content [BMC] ratio [Ip:Tot.BMC] and strength strain index to total BMC ratio [SSI:Tot.BMC]) were quantified. There were significant (p<0.01) site effects for all strength variables and strength-to-mass ratios. Site×sex interaction effects were significant (p<0.05) for all strength variables. Men had greater (p<0.01) values than women for all strength variables. Sex differences in Ip, Imax, Ip:Tot.BMC, SSI, and SSI:Tot.BMC ratios were the smallest at the 15% site and peaked at various sites, depending on variable. Site×age interactions existed for Imax, Ip:Tot.BMC, and SSI:Tot.BMC. There were significant age effects, Imax, Ip:Tot.BMC, and SSI:Tot.BMC, as values were the lowest in the 20-29 age group. Age and sex differences varied by measurement site and variable, and larger sex differences existed for moments of inertia than SSI. Strength-to-mass ratios may reflect efficiency of the whole bone architecture.

  1. Effect of rapid set binder on early strength and permeability of HES latex modified road repair pre-packed concrete

    NASA Astrophysics Data System (ADS)

    Han, J. W.; Lee, S. K.; Yu, C.; Park, C. G.

    2015-12-01

    The early strength development characteristics and permeability resistance of high early strength (HES) pre-packed road repair concrete incorporating a rapid-set binder material were evaluated for emergency repairs to road pavement. The rapid-set binder is a mixture of rapid-set cement and silica sands whose fluidity improves with the addition of styrene butadiene latex (latex). The resulting mixture has a compressive strength of 21 MPa or higher and a flexural strength of greater than 3.5 MPa after 4 hours, the maximum curing age allowed for emergency repair materials. This study examines the strength development properties and permeability resistance of HES latex-modified pre-packed road repair concrete using a rapid- set binder as a function of the latex-to-binder mixing ratio at values of 0.40, 0.33, 0.29 and 0.25. Both early strength development properties and permeability resistance increased as the ratio of latex to rapid-set binder decreased. The mixture showed a compressive strength of 21 MPa or higher after 4 hours, which is the design standard of emergency repair concrete, only when this ratio was 0.29 or lower. A flexural strength of 3.5 MPa or greater was observed after hours only when this ratio was 0.33 or lower. The standard for permeability resistance, less than 2,000 C of chloride after 7 days of curing, was satisfied by all ratios. The ratio of latex to rapid-set binder satisfying all of the conditions for an emergency road repair material was 0.29 or less.

  2. Using Strengths-Based Approaches in Early Years Practice and Research

    ERIC Educational Resources Information Center

    Fenton, Angela; Walsh, Kerryann; Wong, Sandie; Cumming, Tamara

    2015-01-01

    Strengths-based approaches draw upon frameworks and perspectives from social work and psychology but have not necessarily been consistently defined or well articulated across disciplines. Internationally, there are increasing calls for professionals in early years settings to work in strengths-based ways to support the access and participation of…

  3. Using Strengths-Based Approaches in Early Years Practice and Research

    ERIC Educational Resources Information Center

    Fenton, Angela; Walsh, Kerryann; Wong, Sandie; Cumming, Tamara

    2015-01-01

    Strengths-based approaches draw upon frameworks and perspectives from social work and psychology but have not necessarily been consistently defined or well articulated across disciplines. Internationally, there are increasing calls for professionals in early years settings to work in strengths-based ways to support the access and participation of…

  4. Age and gender, two key factors in the associations between physical activity and strength during the ageing process.

    PubMed

    Gómez-Cabello, Alba; Carnicero, Jose A; Alonso-Bouzón, Cristina; Tresguerres, Jesús Ángel; Alfaro-Acha, Ana; Ara, Ignacio; Rodriguez-Mañas, Leocadio; García-García, Francisco-José

    2014-06-01

    The aims of this study were to identify if the associations of physical activity (PA) and muscle strength may vary throughout the ageing process; to study the differences among genders in the relationships between PA and strength in elderly people and to test whether these differences are explained by the hormonal, nutritional and inflammatory status. A total of 1741 people ≥65 years of age participated in this cross-sectional study. Upper- and lower-limbs maximal voluntary isometric strength was obtained using standardized techniques and equipment. PA was recorded by a validated questionnaire. The associations of PA with strength were assessed using generalized linear regression models with a Gamma-distributed dependent variable. A significant gender by PA interaction was found for all strength-related variables (all P<0.01). Moreover, when sexual hormones, albumin or C-Reactive protein were taken into account in the model, the results did not significantly change. In women, PA was positively associated with upper and lower-body strength; however in men, PA was only associated with grip and knee strength (both P<0.01). Higher strength values were associated with higher levels of PA, especially in women. However, this tendency had a different pattern across the age range, showing a stronger association in the 'young' elderly compared with the 'old' elderly. Higher levels of PA are related to greater muscle strength, especially in women and those who were younger. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Strength Training to Enhance Early Recovery after Hematopoietic Stem Cell Transplantation.

    PubMed

    Hacker, Eileen Danaher; Collins, Eileen; Park, Chang; Peters, Tara; Patel, Pritesh; Rondelli, Damiano

    2017-04-01

    Intensive cancer treatment followed by hematopoietic stem cell transplantation (HCT) results in moderate to severe fatigue and physical inactivity, leading to diminished functional ability. The purpose of this study was to determine the efficacy of an exercise intervention, strength training to enhance early recovery (STEER), on physical activity, fatigue, muscle strength, functional ability, and quality of life after HCT. This single-blind, randomized clinical trial compared strength training (n = 33) to usual care plus attention control with health education (UC + AC with HE) (n = 34). Subjects were stratified by type of transplantation and age. STEER consisted of a comprehensive program of progressive resistance introduced during hospitalization and continued for 6 weeks after hospital discharge. Fatigue, physical activity, muscle strength, functional ability, and quality of life were assessed before HCT hospital admission and after intervention completion. Data were analyzed using split-plot analysis of variance. Significant time × group interactions effects were noted for fatigue (P = .04). The STEER group reported improvement in fatigue from baseline to after intervention whereas the UC + AC with HE group reported worsened fatigue from baseline to after intervention. Time (P < .001) and group effects (P = .05) were observed for physical activity. Physical activity declined from baseline to 6 weeks after hospitalization. The STEER group was more physically active. Functional ability tests (timed stair climb and timed up and go) resulted in a significant interaction effect (P = .03 and P = .05, respectively). Subjects in the UC + AC with HE group were significantly slower on both tests baseline to after intervention, whereas the STEER group's time remained stable. The STEER group completed both tests faster than the UC + AC with HE group after intervention. Study findings support the use of STEER after intensive cancer treatment and HCT

  6. The effects of changes of ankle strength and range of motion according to aging on balance.

    PubMed

    Bok, Soo-Kyung; Lee, Tae Heon; Lee, Sang Sook

    2013-02-01

    To investigate the changes of ankle strength and range of motion with aging and which of the ankle strength and range of motion are contributed to balance. Sixty healthy people (24 men and 36 women) have undergone tests for ankle strength and range of motion, using Biodex System 4 Pro; a one-leg balance, including postural sway and stability index using a Balance System; in which data were collected in a self-reported Desmond fall risk questionnaire. Participants are classified into 3 groups by age (group 1, 20-40 years; group 2, 40-65 years; group 3, over 65 years). Stability index and postural sway is significantly increased with aging. Ankle plantarflexor strength and ankle eversion range of motion is significantly decreased with aging. Pearson's correlation revealed that ankle plantarflexor strength is significantly correlated with anterior/posterior sway, and ankle eversion range of motion is significantly correlated with medial/lateral sway in the aged group (over 65 years). Stability, ankle plantarflexor strength, and eversion range of motion is declined with aging. In addition, strength of ankle plantarflexor and eversion range of motion is significantly correlated with balance stability. Further studies are needed for programs to improve the strength of plantarflexor, and range of motion of eversion of the ankle are beneficial in improving balance, stability, and prevention of falling in the elderly.

  7. Is Hip Abduction Strength Asymmetry Present in Female Runners in the Early Stages of Patellofemoral Pain Syndrome?

    PubMed

    Plastaras, Christopher; McCormick, Zack; Nguyen, Cayli; Rho, Monica; Nack, Susan Hillary; Roth, Dan; Casey, Ellen; Carneiro, Kevin; Cucchiara, Andrew; Press, Joel; McLean, Jim; Caldera, Franklin

    2016-01-01

    The current literature indicates that hip abduction weakness in female patients is associated with ipsilateral patellofemoral pain syndrome (PFPS) as part of the weaker hip abductor complex. Thus, it has been suggested that clinicians should consider screening female athletes for hip strength asymmetry to identify those at risk of developing PFPS to prevent the condition. However, no study to date has demonstrated that hip strength asymmetry exists in the early stages of PFPS. To determine whether hip abduction strength asymmetry exists in female runners with early unilateral PFPS, defined as symptoms of PFPS not significant enough to cause patients to seek medical attention or prevent them from running at least 10 miles per week. Controlled laboratory study. This study consisted of 21 female runners (mean age, 30.5 years; range, 18-45 years) with early unilateral PFPS, who had not yet sought medical care and who were able to run at least 10 miles per week, and 36 healthy controls comparably balanced for age, height, weight, and weekly running mileage (mean, 18.5 mi/wk). Study volunteers were recruited using flyers and from various local running events in the metropolitan area. Bilateral hip abduction strength in both a neutral and extended hip position was measured using a handheld dynamometer in each participant by an examiner blinded to group assignment. Patients with early unilateral PFPS demonstrated no significant side-to-side difference in hip abduction strength, according to the Hip Strength Asymmetry Index, in both a neutral (mean, 83.5 ± 10.2; P = .2272) and extended hip position (mean, 96.3 ± 21.9; P = .6671) compared with controls (mean, 87.0 ± 8.3 [P = .2272] and 96.6 ± 16.2 [P = .6671], respectively). Hip abduction strength of the affected limb in patients with early unilateral PFPS (mean, 9.9 ± 2.2; P = .0305) was significantly stronger than that of the weaker limb of control participants (mean, 8.9 ± 1.4; P = .0305) when testing strength in a

  8. Age-related decline in handgrip strength differs according to gender.

    PubMed

    Vianna, Lauro C; Oliveira, Ricardo B; Araújo, Claudio Gil S

    2007-11-01

    It is well-established that at old age there is a significant decline in muscle strength. Reference values for muscle strength might be useful for assessment of muscle impairment and of physiological adaptations. However, it is still unclear whether gender affects the rate of decline. Therefore, the aim of this study is to investigate the effect of gender and age on handgrip strength and to establish reference values for this variable. Reviewing medical charts collected from 1994 to 2005, a convenience sample of 2,648 subjects (1,787 men and 861 women), aged between 18 and 90 years, was obtained. Our results show higher handgrip strength for men compared with women (36.8 +/- 0.20 vs. 21.0 +/- 0.18 kg; p < 0.001). The regression analysis with a quadratic model shows that aging accounts for 30% of the variance in handgrip strength (r(2) = 0.30; p < 0.001) in men and 28% (r(2) = 0.28; p < 0.001) in women. In addition, the bent linear regression with multiple regressors show that a faster decline in handgrip strength occurs at the age of 30 years for men and 50 years for women. We conclude that handgrip strength decline with age differs between genders, making useful the existence of distinct male and female normative age group data.

  9. Strength-Based Factors for Successful Adaptation to an Early College High School Environment

    ERIC Educational Resources Information Center

    Abernethy, Catherine

    2010-01-01

    In an early college high school setting, students are subject to varying academic, social and contextual demands of a higher educational environment. In a strength-based study of 136 diverse early college high school students, this research explored the relationship of internal and external developmental assets to adaptive functioning of…

  10. Evaluation of the bond strength between aged composite cores and luting agent

    PubMed Central

    2015-01-01

    PURPOSE The aim of this study was to evaluate effect of different surface treatment methods on the bond strength between aged composite-resin core and luting agent. MATERIALS AND METHODS Seventy-five resin composites and also seventy-five zirconia ceramic discs were prepared. 60 composite samples were exposed to thermal aging (10,000 cycles, 5 to 55℃) and different surface treatment. All specimens were separated into 5 groups (n=15): 1) Intact specimens 2) Thermal aging-air polishing 3) Thermal aging- Er:YAG laser irradiation 4) Thermal aging- acid etching 5) Thermal-aging. All specimens were bonded to the zirconia discs with resin cement and fixed to universal testing machine and bond strength testing loaded to failure with a crosshead speed of 0.5 mm/min. The fractured surface was classified as adhesive failure, cohesive failure and adhesive-cohesive failure. The bond strength data was statistically compared by the Kruskal-Wallis method complemented by the Bonferroni correction Mann-Whitney U test. The probability level for statistical significance was set at α=.05. RESULTS Thermal aging and different surface treatment methods have significant effect on the bond strength between composite-resin cores and luting-agent (P<.05). The mean baseline bond strength values ranged between 7.07 ± 2.11 and 26.05 ± 6.53 N. The highest bond strength of 26.05 ± 6.53 N was obtained with Group 3. Group 5 showed the lowest value of bond strength. CONCLUSION Appropriate surface treatment method should be applied to aged composite resin cores or aged-composites restorations should be replaced for the optimal bond strength and the clinical success. PMID:25932308

  11. Experiential Aging Activities and the Early Adolescent.

    ERIC Educational Resources Information Center

    Glover, Elbert D.; And Others

    1981-01-01

    Negative views about the elderly held by adolescents can result in a negative outlook on aging. Physical, mental, and social aging experiential activities are given which can be done at home or at school. (JN)

  12. Gender difference in handgrip strength of Italian children aged 9 to 10 years.

    PubMed

    Montalcini, Tiziana; Ferro, Yvelise; Salvati, Maria Antonietta; Romeo, Stefano; Miniero, Roberto; Pujia, Arturo

    2016-02-19

    Handgrip strength is an index of nutritional status which correlates to morbidity and mortality in young. It differs in adults and adolescents between gender. However, it is no clear whether a difference exists also in children aged 9 to 10 years, and which are the factors influencing it. Furthermore, data of Handgrip strength of Italian schoolchildren are lacking. Aim of this study was to provide Handgrip strength value from a sample of healthy Italian schoolchildren aged 9 to 10 years and to determine which factors affect grip strength at this age. We enrolled 137 children (boys n =66; girls n = 71) who underwent a body mass index and Handgrip strength measurement. Handgrip strength was assessed by an hydraulic hand dynamometer. The mean handgrip strength value was 13.8 ± 4.0 for girls and 15.2 ± 3.0 kg for boys (p = 0.04) thus, we found a significant difference between gender. We have not found a significant differences in anthropometric parameters between gender. In the univariate analysis Handgrip strength was associated with age, BMI, height, weight and gender (p < 0.001 for age, p < 0.001 for BMI, p < 0.001 for height, p < 0.001 for weight and p < 0.04 for gender). The Multivariate linear regression analysis showed that age, BMI and gender were all correlated to grip force. We found a significant difference in grip strength between healthy Italian schoolchildren aged 9 to 10 years. This parameter seems to be primarily influenced by gender. Our investigation is important since currently data regarding the reference values of HGS for Italian children are lacking.

  13. Early high calcium and phosphorus intake by parenteral nutrition prevents short-term bone strength decline in preterm infants.

    PubMed

    Pereira-da-Silva, L; Costa, Ab; Pereira, L; Filipe, Af; Virella, D; Leal, E; Moreira, Ac; Rosa, Ml; Mendes, L; Serelha, M

    2011-02-01

    Very premature newborns have an increased risk of low bone mass and metabolic bone disease. Most longitudinal studies report a significant decline in bone strength in the first weeks after birth. The aim of the study was to evaluate whether higher early calcium (Ca) and phosphorus (P) intake delivered by parenteral nutrition (PN) can prevent bone strength decline in preterm infants, within the first weeks after birth. This was a randomized controlled trial of consecutively admitted neonates born with ≤ 33 weeks of gestational age, assigned to receive either Ca 45 mg · kg⁻¹ · day⁻¹ (low dose [LD]) or Ca 75 mg · kg⁻¹ · day⁻¹ (high dose [HD]) by PN. P was added to the PN solutions at a fixed Ca:P ratio (mg) of 1.7:1. Bone strength was assessed by the speed of sound (SOS) using the quantitative ultrasound method. Measurements were performed weekly from birth until discharge. Low bone strength (SOS < 10th centile of reference values) was the main outcome. Eighty-six infants were enrolled, 40 assigned to LD group and 46 to HD group. Mean (standard error) gestational age was 29.6 weeks (2.1) and birth weight was 1262 g (0.356). In the HD group, the SOS values never fell below those recorded at birth and, up to the sixth week of life, low bone strength was significantly less frequent as compared with that in the LD group, in spite of progressive reduction in parenteral mineral intake and/or establishment of full enteral feeding. Early assigned parenteral intake of Ca 75 mg · kg⁻¹ · day⁻¹ and P 44 mg · kg⁻¹ · day⁻¹ significantly contributed to preventing short-term bone strength decline in preterm infants.

  14. YIELD STRENGTH PREDICTION FOR RAPID AGE-HARDENING HEAT TREATMENT OF ALUMINUM ALLOYS

    SciTech Connect

    Yin, Hebi; Sabau, Adrian S; Ludtka, Gerard Michael; Skszek, Timothy; Niu, X

    2013-01-01

    A constitutive model has been developed to predict the yield strength aging curves for aluminum casting alloys during non-isothermal age-hardening processes. The model provides the specific relationship between the process variables and yield strength. Several aging heat treatment scenarios have been investigated using the proposed model, including two-step aging recipes. Two-step aging heat treatments involve a low temperature regime to promote nucleation of secondary phases and a second step at higher temperature for the growth of the secondary phases. The predicted results show that yield strength of approximately 300MPa might be obtained in shorter aging time, of approximately 30 minutes. Thus, better mechanical properties can be obtained by optimizing the time-temperature schedules for the precipitation hardening process of heat treatable aluminum alloys.

  15. Physics and Chemistry of Aging - Early Developments

    SciTech Connect

    Va'vra, Jaroslav

    2002-02-22

    The aging phenomena are very complex physical and chemical processes. The author attempts to qualitatively discuss various physical processes contributing to aging. The satisfactory quantitative explanation is not presently available. In this sense, there is little progress made since the 1986 LBL Aging Workshop. However, what was accomplished during the past decade is a heighten awareness from the research and management sides to pay more attention to this problem, and as a result a number of aging tests have increased in quantity and quality. These efforts will undoubtedly yield some new results in the future. Examples in this paper are mainly from a ''pre-LHC and pre-HERA-B era of aging,'' where the total charge doses is limited to much less than one C/cm.

  16. Horizontal abduction and adduction strength at the shoulder of high school wrestlers across age.

    PubMed

    Weir, J P; Wagner, L L; Housh, T J; Johnson, G O

    1992-01-01

    Previous studies have indicated an age effect in the strength of high school wrestlers. The purpose of this investigation was to quantify horizontal abduction and adduction strengths at the shoulder in high school wrestlers and to examine the age effect for these movements. Seventy-nine high school wrestlers (age = 16.28 +/- 1.26 yrs) were stratified into four groups corresponding to the ages of the wrestlers during their freshman, sophomore, junior, and senior years. The subjects were tested for horizontal abduction and adduction strength at the shoulder at 30, 180, and 300 degrees /sec. Body composition was determined from underwater weighing. The results of this study indicated that absolute peak torque and peak torque divided by body weight or fat-free weight increased across age at 30 degrees /sec for abduction and adduction as well as at 180 degrees /sec for adduction. No significant differences in absolute or relative strength across age were noted at 180 degrees /sec for abduction or at 300 degrees /sec for abduction and adduction. These results suggest an age effect for muscular strength development in high school wrestlers that is independent of increases in body weight and fat-free weight. In addition, these results provide normative data for comparisons with other athletes and nonathletes and may be used for assessing readiness to return to activity after in jury. J Orthop Sports Phys Ther 1992;15(4):183-186.

  17. Effects of surface conditioning on repair bond strengths of non-aged and aged microhybrid, nanohybrid, and nanofilled composite resins.

    PubMed

    Rinastiti, Margareta; Özcan, Mutlu; Siswomihardjo, Widowati; Busscher, Henk J

    2011-10-01

    This study evaluates effects of aging on repair bond strengths of microhybrid, nanohybrid, and nanofilled composite resins and characterizes the interacting surfaces after aging. Disk-shaped composite specimens were assigned to one of three aging conditions: (1) thermocycling (5,000 ×, 5-55 °C), (2) storage in water at 37 °C for 6 months, or (3) immersion in citric acid at 37 °C, pH 3 for 1 week; a non-aged group acted as the control. Two surface conditionings were selected: intermediate adhesive resin application (IAR-application) and chairside silica coating followed by silanization and its specific IAR-application (SC-application). Composite resins, of the same kind as their substrate, were adhered onto the substrates, and repair shear bond strengths were determined, followed by failure type evaluation. Filler particle exposure was determined by X-ray photoelectron spectroscopy and surface roughness analyzed using scanning electron and atomic force microscopy. Surface roughness increased in all composite resins after aging, but filler particle exposure at the surface only increased after thermocycling and citric acid immersion. Composite resin type, surface conditioning, and aging method significantly influenced the repair bond strengths (p < 0.05, three-way analysis of variance) with the least severe effects of water storage. Repair bond strengths in aged composite resins after IAR-application were always lower in non-aged ones, while SC-application led to higher bond strengths than IAR-application after thermocycling and water storage. In addition, SC-application led to more cohesive failures than after IAR-application, regardless the aging method.

  18. The Relationship Between Greater Prepubertal Adiposity, Subsequent Age of Maturation, and Bone Strength During Adolescence.

    PubMed

    Glass, Natalie A; Torner, James C; Letuchy, Elena M; Burns, Trudy L; Janz, Kathleen F; Eichenberger Gilmore, Julie M; Schlechte, Janet A; Levy, Steven M

    2016-07-01

    This longitudinal study investigated whether greater prepubertal adiposity was associated with subsequent timing of maturation and bone strength during adolescence in 135 girls and 123 boys participating in the Iowa Bone Development Study. Greater adiposity was defined using body mass index (BMI) data at age 8 years to classify participants as overweight (OW, ≥85th percentile for age and sex) or healthy weight (HW). Maturation was defined as the estimated age of peak height velocity (PHV) based on a series of cross-sectional estimates. Measurements were taken at ages 11, 13, 15, and 17 years for estimates of body composition by dual-energy X-ray absorptiometry (DXA), bone compression (bone strength index), and torsion strength (polar strength-strain index) at the radius and tibia by pQCT, and femoral neck bending strength (section modulus) by hip structural analysis. Bone strength in OW versus HW were evaluated by fitting sex-specific linear mixed models that included centered age (visit age - grand mean age of cohort) as the time variable and adjusted for change in fat mass, and limb length in model 1. Analyses were repeated using biological age (visit age - age PHV) as the time variable for model 1 with additional adjustment for lean mass in model 2. BMI was negatively associated with age of maturation (p < 0.05). OW versus HW girls had significantly greater bone strength (p < 0.001) in model 1, whereas OW versus HW boys had significantly greater bone strength (p < 0.001) at the tibia and femoral neck but not radius (p > 0.05). Analyses were repeated using biological age, which yielded reduced parameter estimates for girls but similar results for boys (model 1.) Differences were no longer present after adjustment for lean mass (model 2) in girls (p > 0.05) whereas differences at the tibia were sustained in boys (p < 0.05). These findings demonstrate sex- and site-specific differences in the associations between adiposity, maturation, and

  19. Early Literacy Promotion in the Digital Age.

    PubMed

    Navsaria, Dipesh; Sanders, Lee M

    2015-10-01

    School readiness and educational success is strongly mediated by early literacy skills. In both exam-room and community-based settings, child-health providers can affect the trajectory of early literacy by implementing evidence-based, culturally appropriate interventions that support child development, parenting skills, and child-caregiver interaction. Despite limited research on the subject, these interventions should also attend to the evolving role of digital-media exposure (both positive and negative) on the developmental health of children. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Age-related changes in muscle strength and spinal kyphosis angles in an elderly Japanese population

    PubMed Central

    Kasukawa, Yuji; Miyakoshi, Naohisa; Hongo, Michio; Ishikawa, Yoshinori; Kudo, Daisuke; Suzuki, Masazumi; Mizutani, Takashi; Kimura, Ryouta; Ono, Yuichi; Shimada, Yoichi

    2017-01-01

    Lumbar kyphosis and the decreased mobility of the lumbar spine increase the risk of falls and impair both the quality of life and the ability to perform activities of daily living. However, in the elderly Japanese population, little is known about the age-related changes and sex-related differences in muscle strength, including of the upper and lower extremities and back extensors. An adequate kyphotic or lordotic angle has also not been determined. In this study, we evaluated the age-related changes in muscle strength and spinal kyphosis in 252 males and 320 females ≥50 years of age. Grip, back extensor, hip flexor, and knee extensor strength; thoracic and lumbar kyphosis; and spinal inclination in the neutral standing position were assessed, together with the range of motion of the thoracic and lumbar spine and spinal inclination. Grip strength, back extensor strength, and the strength of the hip flexors and knee extensors decreased significantly with aging, both in males (P<0.0001) and in females (P=0.0015 to P<0.0001). The lumbar but not the thoracic kyphosis angle decreased significantly with aging, only in females (P<0.0001). Spinal inclination increased significantly with aging in both males (P=0.002) and females (P<0.0001). Back extensor strength and the thoracic kyphosis angle were significant variables influencing the lumbar kyphosis angle in both sexes. Spinal inclination correlated significantly with both the lumbar kyphosis angle and hip flexor strength in males, as well as with the lumbar kyphosis angle in females. PMID:28260870

  1. Age-related changes in muscle strength and spinal kyphosis angles in an elderly Japanese population.

    PubMed

    Kasukawa, Yuji; Miyakoshi, Naohisa; Hongo, Michio; Ishikawa, Yoshinori; Kudo, Daisuke; Suzuki, Masazumi; Mizutani, Takashi; Kimura, Ryouta; Ono, Yuichi; Shimada, Yoichi

    2017-01-01

    Lumbar kyphosis and the decreased mobility of the lumbar spine increase the risk of falls and impair both the quality of life and the ability to perform activities of daily living. However, in the elderly Japanese population, little is known about the age-related changes and sex-related differences in muscle strength, including of the upper and lower extremities and back extensors. An adequate kyphotic or lordotic angle has also not been determined. In this study, we evaluated the age-related changes in muscle strength and spinal kyphosis in 252 males and 320 females ≥50 years of age. Grip, back extensor, hip flexor, and knee extensor strength; thoracic and lumbar kyphosis; and spinal inclination in the neutral standing position were assessed, together with the range of motion of the thoracic and lumbar spine and spinal inclination. Grip strength, back extensor strength, and the strength of the hip flexors and knee extensors decreased significantly with aging, both in males (P<0.0001) and in females (P=0.0015 to P<0.0001). The lumbar but not the thoracic kyphosis angle decreased significantly with aging, only in females (P<0.0001). Spinal inclination increased significantly with aging in both males (P=0.002) and females (P<0.0001). Back extensor strength and the thoracic kyphosis angle were significant variables influencing the lumbar kyphosis angle in both sexes. Spinal inclination correlated significantly with both the lumbar kyphosis angle and hip flexor strength in males, as well as with the lumbar kyphosis angle in females.

  2. Internationally Adopted Children in the Early School Years: Relative Strengths and Weaknesses in Language Abilities

    ERIC Educational Resources Information Center

    Glennen, Sharon

    2015-01-01

    Purpose: This study aimed to determine the relative strengths and weaknesses in language and verbal short-term memory abilities of school-age children who were adopted from Eastern Europe. Method: Children adopted between 1;0 and 4;11 (years;months) of age were assessed with the Clinical Evaluation of Language Fundamentals-Preschool, Second…

  3. Internationally Adopted Children in the Early School Years: Relative Strengths and Weaknesses in Language Abilities

    ERIC Educational Resources Information Center

    Glennen, Sharon

    2015-01-01

    Purpose: This study aimed to determine the relative strengths and weaknesses in language and verbal short-term memory abilities of school-age children who were adopted from Eastern Europe. Method: Children adopted between 1;0 and 4;11 (years;months) of age were assessed with the Clinical Evaluation of Language Fundamentals-Preschool, Second…

  4. Children of Two to Three Years of Age in France: Early Childhood Settings and Age Divisions

    ERIC Educational Resources Information Center

    Garnier, Pascale; Rayna, Sylvie; Brougère, Gilles; Rupin, Pablo

    2017-01-01

    In a French early childhood care and education system that is strongly divided by age and institution, the current research studies the collective life of children at the pivotal age of two to three years of age in four different early childhood settings: (1) a group of "grands" (nursery) in a "crèche" (daycare centre), (2) a…

  5. Age at Menarche Is Associated with Divergent Alcohol Use Patterns in Early Adolescence and Early Adulthood

    ERIC Educational Resources Information Center

    Richards, Meghan A.; Oinonen, Kirsten A.

    2011-01-01

    A cross-sectional retrospective design was employed to examine the relationship between age at menarche (AAM) and alcohol use patterns from middle childhood (age 7) to early adulthood in 265 University-aged women. Earlier menarche was associated with: (a) earlier ages at first drink and first intoxication, (b) greater use between ages 9 and 14…

  6. Age at Menarche Is Associated with Divergent Alcohol Use Patterns in Early Adolescence and Early Adulthood

    ERIC Educational Resources Information Center

    Richards, Meghan A.; Oinonen, Kirsten A.

    2011-01-01

    A cross-sectional retrospective design was employed to examine the relationship between age at menarche (AAM) and alcohol use patterns from middle childhood (age 7) to early adulthood in 265 University-aged women. Earlier menarche was associated with: (a) earlier ages at first drink and first intoxication, (b) greater use between ages 9 and 14…

  7. Strength and Aerobic Exercises Improve Spatial Memory in Aging Rats Through Stimulating Distinct Neuroplasticity Mechanisms.

    PubMed

    Vilela, Thais Ceresér; Muller, Alexandre Pastoris; Damiani, Adriani Paganini; Macan, Tamires Pavei; da Silva, Sabrina; Canteiro, Paula Bortoluzzi; de Sena Casagrande, Alisson; Pedroso, Giulia Dos Santos; Nesi, Renata Tiscoski; de Andrade, Vanessa Moraes; de Pinho, Ricardo Aurino

    2016-11-22

    Aging is associated with impaired cognition and memory and increased susceptibility to neurodegenerative disorders. Physical exercise is neuroprotective; however, the major evidence of this effect involves studies of only aerobic training in young animals. The benefits of other exercise protocols such as strength training in aged animals remains unknown. Here, we investigated the effect of aerobic and strength training on spatial memory and hippocampal plasticity in aging rats. Aging Wistar rats performed aerobic or strength training for 50 min 3 to 4 days/week for 8 weeks. Spatial memory and neurotrophic and glutamatergic signaling in the hippocampus of aged rats were evaluated after aerobic or strength training. Both aerobic and strength training improved cognition during the performance of a spatial memory task. Remarkably, the improvement in spatial memory was accompanied by an increase in synaptic plasticity proteins within the hippocampus after exercise training, with some differences in the intracellular functions of those proteins between the two exercise protocols. Moreover, neurotrophic signaling (CREB, BDNF, and the P75(NTR) receptor) increased after training for both exercise protocols, and aerobic exercise specifically increased glutamatergic proteins (NMDA receptor and PSD-95). We also observed a decrease in DNA damage after aerobic training. In contrast, strength training increased levels of PKCα and the proinflammatory factors TNF-α and IL-1β. Overall, our results show that both aerobic and strength training improved spatial memory in aging rats through inducing distinct molecular mechanisms of neuroplasticity. Our findings extend the idea that exercise protocols can be used to improve cognition during aging.

  8. Association between obesity and femoral neck strength according to age, sex, and fat distribution.

    PubMed

    Kim, H; Lee, S H; Kim, B J; Koh, J M

    2017-03-29

    Indicators of total and abdominal obesity were negatively associated with femoral neck strength indices. There are age-, sex-, and fat distribution-specific differences in the magnitude of these associations. These suggested that indicators of obesity with different magnitude according to age, sex, and fat distribution associated with poor bone health.

  9. Motor Competence in Early Childhood Is Positively Associated With Bone Strength in Late Adolescence

    PubMed Central

    Sayers, Adrian; Deere, Kevin C; Emond, Alan; Tobias, Jon H

    2016-01-01

    ABSTRACT The onset of walking in early childhood results in exposure of the lower limb to substantial forces from weight bearing activity that ultimately contribute to adult bone strength. Relationships between gross motor score (GMS), at 18 months and bone outcomes measured at age 17 years were examined in 2327 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Higher GMS indicated greater motor competence in weight‐bearing activities. Total hip bone mineral density (BMD) and hip cross‐sectional moment of inertia (CSMI) were assessed from dual‐energy X‐ray absorptiometry (DXA). Bone measures including cortical bone mineral content (BMC), periosteal circumference (PC), cortical thickness (CT), cortical bone area (CBA), cortical BMD (BMDC) and cross‐sectional moment of inertia (CSMI) were assessed by peripheral quantitative computed tomography (pQCT) at 50% distal‐proximal length. Before adjustment, GMS was associated with hip BMD, CSMI, and tibia BMC, PC, CT, CBA and CSMI (all p < 0.001) but not BMDC (p > 0.25). Strongest associations (standardized regression coefficients with 95% CI) were between GMS and hip BMD (0.086; 95% CI, 0.067 to 0.105) and tibia BMC (0.105; 95% CI, 0.089 to 0.121). With the exception of hip BMD, larger regression coefficients were observed in males (gender interactions all p < 0.05). Adjustment for lean mass resulted in substantial attenuation of regression coefficients, suggesting associations between impaired motor competence and subsequent bone development are partly mediated by alterations in body composition. In conclusion, impaired motor competence in childhood is associated with lower adolescent bone strength, and may represent a risk factor for subsequent osteoporosis. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR). PMID:26713753

  10. Evolution of the early Antarctic ice ages

    NASA Astrophysics Data System (ADS)

    Liebrand, Diederik; de Bakker, Anouk T. M.; Beddow, Helen M.; Wilson, Paul A.; Bohaty, Steven M.; Ruessink, Gerben; Pälike, Heiko; Batenburg, Sietske J.; Hilgen, Frederik J.; Hodell, David A.; Huck, Claire E.; Kroon, Dick; Raffi, Isabella; Saes, Mischa J. M.; van Dijk, Arnold E.; Lourens, Lucas J.

    2017-04-01

    Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-sea oxygen isotope (δ18O) record from the South Atlantic Ocean spanning an interval between 30.1 My and 17.1 My ago. The record displays major oscillations in deep-sea temperature and Antarctic ice volume in response to the ˜110-ky eccentricity modulation of precession. Conservative minimum ice volume estimates show that waxing and waning of at least ˜85 to 110% of the volume of the present East Antarctic Ice Sheet is required to explain many of the ˜110-ky cycles. Antarctic ice sheets were typically largest during repeated glacial cycles of the mid-Oligocene (˜28.0 My to ˜26.3 My ago) and across the Oligocene-Miocene Transition (˜23.0 My ago). However, the high-amplitude glacial-interglacial cycles of the mid-Oligocene are highly symmetrical, indicating a more direct response to eccentricity modulation of precession than their Early Miocene counterparts, which are distinctly asymmetrical—indicative of prolonged ice buildup and delayed, but rapid, glacial terminations. We hypothesize that the long-term transition to a warmer climate state with sawtooth-shaped glacial cycles in the Early Miocene was brought about by subsidence and glacial erosion in West Antarctica during the Late Oligocene and/or a change in the variability of atmospheric CO2 levels on astronomical time scales that is not yet captured in existing proxy reconstructions.

  11. Evolution of the early Antarctic ice ages

    PubMed Central

    de Bakker, Anouk T. M.; Beddow, Helen M.; Wilson, Paul A.; Bohaty, Steven M.; Pälike, Heiko; Batenburg, Sietske J.; Hilgen, Frederik J.; Hodell, David A.; Huck, Claire E.; Kroon, Dick; Raffi, Isabella; Saes, Mischa J. M.; van Dijk, Arnold E.; Lourens, Lucas J.

    2017-01-01

    Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-sea oxygen isotope (δ18O) record from the South Atlantic Ocean spanning an interval between 30.1 My and 17.1 My ago. The record displays major oscillations in deep-sea temperature and Antarctic ice volume in response to the ∼110-ky eccentricity modulation of precession. Conservative minimum ice volume estimates show that waxing and waning of at least ∼85 to 110% of the volume of the present East Antarctic Ice Sheet is required to explain many of the ∼110-ky cycles. Antarctic ice sheets were typically largest during repeated glacial cycles of the mid-Oligocene (∼28.0 My to ∼26.3 My ago) and across the Oligocene−Miocene Transition (∼23.0 My ago). However, the high-amplitude glacial−interglacial cycles of the mid-Oligocene are highly symmetrical, indicating a more direct response to eccentricity modulation of precession than their Early Miocene counterparts, which are distinctly asymmetrical—indicative of prolonged ice buildup and delayed, but rapid, glacial terminations. We hypothesize that the long-term transition to a warmer climate state with sawtooth-shaped glacial cycles in the Early Miocene was brought about by subsidence and glacial erosion in West Antarctica during the Late Oligocene and/or a change in the variability of atmospheric CO2 levels on astronomical time scales that is not yet captured in existing proxy reconstructions. PMID:28348211

  12. Evolution of the early Antarctic ice ages.

    PubMed

    Liebrand, Diederik; de Bakker, Anouk T M; Beddow, Helen M; Wilson, Paul A; Bohaty, Steven M; Ruessink, Gerben; Pälike, Heiko; Batenburg, Sietske J; Hilgen, Frederik J; Hodell, David A; Huck, Claire E; Kroon, Dick; Raffi, Isabella; Saes, Mischa J M; van Dijk, Arnold E; Lourens, Lucas J

    2017-04-11

    Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-sea oxygen isotope (δ(18)O) record from the South Atlantic Ocean spanning an interval between 30.1 My and 17.1 My ago. The record displays major oscillations in deep-sea temperature and Antarctic ice volume in response to the ∼110-ky eccentricity modulation of precession. Conservative minimum ice volume estimates show that waxing and waning of at least ∼85 to 110% of the volume of the present East Antarctic Ice Sheet is required to explain many of the ∼110-ky cycles. Antarctic ice sheets were typically largest during repeated glacial cycles of the mid-Oligocene (∼28.0 My to ∼26.3 My ago) and across the Oligocene-Miocene Transition (∼23.0 My ago). However, the high-amplitude glacial-interglacial cycles of the mid-Oligocene are highly symmetrical, indicating a more direct response to eccentricity modulation of precession than their Early Miocene counterparts, which are distinctly asymmetrical-indicative of prolonged ice buildup and delayed, but rapid, glacial terminations. We hypothesize that the long-term transition to a warmer climate state with sawtooth-shaped glacial cycles in the Early Miocene was brought about by subsidence and glacial erosion in West Antarctica during the Late Oligocene and/or a change in the variability of atmospheric CO2 levels on astronomical time scales that is not yet captured in existing proxy reconstructions.

  13. Growth curve analyses of the relationship between early maternal age and children's mathematics and reading performance.

    PubMed

    Torres, D Diego

    2015-03-01

    Regarding the methods used to examine the early maternal age-child academic outcomes relationship, the extant literature has tended to examine change using statistical analyses that fail to appreciate that individuals vary in their rates of growth. Of the one study I have been able to find that employs a true growth model to estimate this relationship, the authors only controlled for characteristics of the maternal household after family formation; confounding background factors of mothers that might select them into early childbearing, a possible source of bias, were ignored. The authors' findings nonetheless suggested an inverse relationship between early maternal age, i.e., a first birth between the ages of 13 and 17, and Canadian adolescents' mean math performance at age 10. Early maternal age was not related to the linear slope of age. To elucidate whether the early maternal age-child academic outcomes association, treated in a growth context, is consistent with this finding, the present study built on it using US data and explored children's mathematics and reading trajectories from age 5 on. Its unique contribution is that it further explicitly controlled for maternal background factors and employed a three-level growth model with repeated measures of children nested within their mothers. Though the strength of the relationship varied between mean initial academic performance and mean academic growth, results confirmed that early maternal age was negatively related to children's mathematics and reading achievement, net of post-teen first birth child-specific and maternal household factors. Once maternal background factors were included, there was no statistically significant relationship between early maternal age and either children's mean initial mathematics and reading scores or their mean mathematics and reading growth.

  14. Activated mesenchymal stem cells increase wound tensile strength in aged mouse model via macrophages.

    PubMed

    Lee, Simon; Szilagyi, Erzsebet; Chen, Lin; Premanand, Kavitha; DiPietro, Luisa A; Ennis, William; Bartholomew, Amelia M

    2013-05-01

    Wound healing is impaired in the aged. Mesenchymal stem cells (MSCs) can exert beneficial effects in wounds; however, promoting healing in the challenging setting of aged skin may require additional potency. MSCs can enhance the production of pro-regenerative cytokines and growth factors when activated with interferon gamma. We hypothesized that the increased potency of activated MSC could be used to facilitate wound healing in the aged mice. Young and old C57BL6 mice underwent incisional wounds and were treated with naive MSCs, activated MSCs, or vehicle to examine MSC effects on tensile strength in the aged skin. To test whether the benefits of MSC treatment could be attributed to the participation of host macrophages, liposomal clodronate was used to deplete host macrophages. In older mice, tensile strength of healing wounds was significantly lower than that in younger mice. Older mice treated with activated MSCs showed significant increases in tensile strength restoring the strength to that observed in younger mice. Macrophage depletion abrogated the beneficial effect of MSC. Activated MSCs restored wound tensile strength in the aged mice, and this effect was dependent on host macrophage activity. These data provide encouraging support for the development of activated MSC therapies for enhanced tissue regeneration, especially for older population groups. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Early thermal profiles and lithospheric strength of Ganymede from extensional tectonic features

    SciTech Connect

    Golombek, M.P.; Banerdt, W.B.

    1986-11-01

    The early thermal profiles and the lithospheric stability and strength of Ganymede are quantitatively determined on the basis of brittle lithosphere thickness estimates derived from the width and spacing of extensional tectonic features, together with lithospheric strength envelopes for ice. Plots of the brittle and ductile yield stress vs. depth for the icy lithosphere of Ganymede exhibit a linear increase in brittle strength with depth to a maximum at the brittle-ductile transition that is followed by an exponential decrease in ductile yield stress with depth. The results obtained imply that the thermal gradient and lithospheric strength have varied laterally by factor as great as 5, and that Ganymede underwent cooling in a highly inhomogeneous fashion with lateral thermal anomalies. The present analysis furnishes reasons for the stability of large cratered terrain remnants. 47 references.

  16. Early thermal profiles and lithospheric strength of Ganymede from extensional tectonic features

    NASA Technical Reports Server (NTRS)

    Golombek, Matthew P.; Banerdt, W. Bruce

    1986-01-01

    The early thermal profiles and the lithospheric stability and strength of Ganymede are quantitatively determined on the basis of brittle lithosphere thickness estimates derived from the width and spacing of extensional tectonic features, together with lithospheric strength envelopes for ice. Plots of the brittle and ductile yield stress vs. depth for the icy lithosphere of Ganymede exhibit a linear increase in brittle strength with depth to a maximum at the brittle-ductile transition that is followed by an exponential decrease in ductile yield stress with depth. The results obtained imply that the thermal gradient and lithospheric strength have varied laterally by factor as great as 5, and that Ganymede underwent cooling in a highly inhomogeneous fashion with lateral thermal anomalies. The present analysis furnishes reasons for the stability of large cratered terrain remnants.

  17. Early Microbial Evolution: The Age of Anaerobes.

    PubMed

    Martin, William F; Sousa, Filipa L

    2015-12-18

    In this article, the term "early microbial evolution" refers to the phase of biological history from the emergence of life to the diversification of the first microbial lineages. In the modern era (since we knew about archaea), three debates have emerged on the subject that deserve discussion: (1) thermophilic origins versus mesophilic origins, (2) autotrophic origins versus heterotrophic origins, and (3) how do eukaryotes figure into early evolution. Here, we revisit those debates from the standpoint of newer data. We also consider the perhaps more pressing issue that molecular phylogenies need to recover anaerobic lineages at the base of prokaryotic trees, because O2 is a product of biological evolution; hence, the first microbes had to be anaerobes. If molecular phylogenies do not recover anaerobes basal, something is wrong. Among the anaerobes, hydrogen-dependent autotrophs--acetogens and methanogens--look like good candidates for the ancestral state of physiology in the bacteria and archaea, respectively. New trees tend to indicate that eukaryote cytosolic ribosomes branch within their archaeal homologs, not as sisters to them and, furthermore tend to root archaea within the methanogens. These are major changes in the tree of life, and open up new avenues of thought. Geochemical methane synthesis occurs as a spontaneous, abiotic exergonic reaction at hydrothermal vents. The overall similarity between that reaction and biological methanogenesis fits well with the concept of a methanogenic root for archaea and an autotrophic origin of microbial physiology. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

  18. Aging process, cognitive decline and Alzheimer`s disease: can strength training modulate these responses?

    PubMed

    Portugal, Eduardo Matta Mello; Vasconcelos, Poliane Gomes Torres; Souza, Renata; Lattari, Eduardo; Monteiro-Junior, Renato Sobral; Machado, Sergio; Deslandes, Andrea Camaz

    2015-01-01

    Some evidence shows that aerobic training can attenuate the aging effects on the brain structures and functions. However, the strength exercise effects are poorly discussed. Thus, in the present study, the effects of strength training on the brain in elderly people and Alzheimer`s disease (AD) patients were revised. Furthermore, it a biological explanation relating to strength training effects on the brain is proposed. Brain atrophy can be related to neurotransmission dysfunction, like oxidative stress, that generates mitochondrial damage and reduced brain metabolism. Another mechanism is related to amyloid deposition and amyloid tangles, that can be related to reductions on insulin-like growth factor I concentrations. The brain-derived neurotrophic factor also presents reduction during aging process and AD. These neuronal dysfunctions are also related to cerebral blood flow decline that influence brain metabolism. All of these alterations contribute to cognitive impairment and AD. After a long period of strength training, the oxidative stress can be reduced, the brain-derived neurotrophic factor and insulin-like growth factor I serum concentrations enhance, and the cognitive performance improves. Considering these results, we can infer that strength training can be related to increased neurogenesis, neuroplasticity and, consequently, counteracts aging effects on the brain. The effect of strength training as an additional treatment of AD needs further investigation.

  19. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns.

    PubMed

    Lameira, Deborah Pacheco; Buarque e Silva, Wilkens Aurélio; Andrade e Silva, Frederico; De Souza, Grace M

    2015-01-01

    The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37 °C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength.

  20. Age-related skeletal dynamics and decrease in bone strength in DNA repair deficient male trichothiodystrophy mice.

    PubMed

    Nicolaije, Claudia; Diderich, Karin E M; Botter, S M; Priemel, Matthias; Waarsing, Jan H; Day, Judd S; Brandt, Renata M C; Schilling, Arndt F; Weinans, Harrie; Van der Eerden, Bram C; van der Horst, Gijsbertus T J; Hoeijmakers, Jan H J; van Leeuwen, Johannes P T M

    2012-01-01

    Accumulation of DNA damage caused by oxidative stress is thought to be one of the main contributors of human tissue aging. Trichothiodystrophy (TTD) mice have a mutation in the Ercc2 DNA repair gene, resulting in accumulation of DNA damage and several features of segmental accelerated aging. We used male TTD mice to study the impact of DNA repair on bone metabolism with age. Analysis of bone parameters, measured by micro-computed tomography, displayed an earlier decrease in trabecular and cortical bone as well as a loss of periosteal apposition and a reduction in bone strength in TTD mice with age compared to wild type mice. Ex vivo analysis of bone marrow differentiation potential showed an accelerated reduction in the number of osteogenic and osteoprogenitor cells with unaltered differentiation capacity. Adipocyte differentiation was normal. Early in life, osteoclast number tended to be increased while at 78 weeks it was significantly lower in TTD mice. Our findings reveal the importance of genome stability and proper DNA repair for skeletal homeostasis with age and support the idea that accumulation of damage interferes with normal skeletal maintenance, causing reduction in the number of osteoblast precursors that are required for normal bone remodeling leading to a loss of bone structure and strength.

  1. Effect of rotation age on lumber grade, yield, and strength of unthinned loblolly pine

    SciTech Connect

    Clark, A.; McAlister, R.H.; Saucier, J.R.; Reitter, K.

    1996-01-01

    This study examines the effect of rotation age on the grade, yield, and strength of lumber produced from unthinned loblolly pine stands in the coastal plain of Georgia. Six stands representing 22-, 28-, and 40-year rotations were sampled. A stratified random sample of trees with diameters at breast height ranging from 8 to 16 inches was selected from each stand and processed into limber. The strength, yield, and grade of lumber produced increased with increasing rotation age. Based on study data, equations were developed to predict total lumber volume, lumber volume by lumber grade, sawlog stem weight, and cubic volume. Because the yeild of higher grade lumber increased in older trees, the value of lumber produced per cubic foot increased significantly with increasing age. A financial analysis of a simulated plantation harvested at ages ranging from 20 to 40 years illustrates the effects of increasing lumber value and rotation age on net present value of an unthinned loblolly pine stand.

  2. Lower Limb Strength in Professional Soccer Players: Profile, Asymmetry, and Training Age

    PubMed Central

    Fousekis, Konstantinos; Tsepis, Elias; Vagenas, George

    2010-01-01

    Kicking and cutting skills in soccer are clearly unilateral, require asymmetrical motor patterns and lead to the development of asymmetrical adaptations in the musculoskeletal function of the lower limbs. Assuming that these adaptations constitute a chronicity-dependent process, this study examined the effects of professional training age (PTA) on the composite strength profile of the knee and ankle joint in soccer players. One hundred soccer players (n=100) with short (5-7 years), intermediate (8-10 years) and long (>11 years) PTA were tested bilaterally for isokinetic concentric and eccentric strength of the knee and ankle muscles. Knee flexion-extension was tested concentrically at 60°, 180° and 300 °/sec and eccentrically at 60° and 180 °/sec. Ankle dorsal and plantar flexions were tested at 60 °/sec for both the concentric and eccentric mode of action. Bilaterally averaged muscle strength [(R+L)/2] increased significantly from short training age to intermediate and stabilized afterwards. These strength adaptations were mainly observed at the concentric function of knee extensors at 60°/sec (p = 0. 023), knee flexors at 60°/sec (p = 0.042) and 180°/sec (p = 0.036), and ankle plantar flexors at 60o/sec (p = 0.044). A linear trend of increase in isokinetic strength with PTA level was observed for the eccentric strength of knee flexors at 60°/sec (p = 0.02) and 180°/sec (p = 0.03). Directional (R/L) asymmetries decreased with PTA, with this being mainly expressed in the concentric function of knee flexors at 180°/sec (p = 0.04) and at 300 °/sec (p = 0.03). These findings confirm the hypothesis of asymmetry in the strength adaptations that take place at the knee and ankle joint of soccer players mainly along with short and intermediate PTA. Players with a longer PTA seem to adopt a more balanced use of their lower extremities to cope with previously developed musculoskeletal asymmetries and possibly reduce injury risk. This has certain implications

  3. Early-age volume changes of extrudable reactive powder concrete

    NASA Astrophysics Data System (ADS)

    Cherkaoui, K.; Courtial, M.; Dunstetter, F.; Khelidj, A.; Mounanga, P.; de Noirfontaine, M. N.

    2010-06-01

    This article presents a study on the early-age autogenous deformations of Extrudable Reactive Powder Concretes (ERPCs), especially designed for the making of concrete pipes by extrusion. Different ERPC mixtures, with variable amounts of polycarboxylate superplasticizer (SP), have been investigated. Results on 28-day mechanical properties, early-age hydration rate, autogenous shrinkage and premature cracking risk are analyzed and discussed in relation with the ERPC mix parameters.

  4. Effects of Age on Strength and Morphology of Toe Flexor Muscles.

    PubMed

    Mickle, Karen J; Angin, Salih; Crofts, Gillian; Nester, Christopher J

    2016-12-01

    Study Design Descriptive, cross-sectional. Background Age-related muscle atrophy is common in lower-limb muscles. We therefore speculated that foot muscles may also diminish with age. However, there is a paucity of literature characterizing foot muscle strength and morphology, and any relationship between these 2, in older people. Objective To compare the strength and size of the toe flexor muscles of older adults relative to their younger counterparts. Methods Seventeen young adults with a normal foot type were matched by sex and body mass index to 17 older adults with a normal foot type, from an available sample of 41 younger (18 to 50 years of age) and 44 older (60 or more years of age) adults. Among the matched groups (n = 34), muscle thickness and cross-sectional area for 5 intrinsic and 2 extrinsic toe flexor muscles were obtained using ultrasound. Toe strength was assessed using a pressure platform. Differences in toe flexor strength and muscle size between the young and older matched groups were determined using analysis of covariance (controlling for height). Correlations between strength and size of the toe flexor muscles of the pooled group (n = 34) were also calculated. Results Toe strength and the thickness and cross-sectional area of most foot muscles were significantly reduced in the older adults (P<.05). Hallux and toe flexor strength values were strongly correlated with the size of the intrinsic toe flexor muscles. Conclusion The smaller foot muscles appear to be affected by sarcopenia in older adults. This could contribute to reduced toe flexion force production and may affect the ability of older people to walk safely. Interventions aimed at reversing foot muscle atrophy in older people require further investigation. J Orthop Sports Phys Ther 2016;46(12):1065-1070. Epub 29 Oct 2016. doi:10.2519/jospt.2016.6597.

  5. Early Parenthood and Coming of Age in the 1990s.

    ERIC Educational Resources Information Center

    Rosenheim, Margaret K., Ed.; Testa, Mark F., Ed.

    This book examines how early parenthood differs historically, cross-nationally (in Korea and Sweden), and by class, race, and age in the United States. Contributors discuss how consequential is early parenthood for the future social and economic well-being of parents and children, whether postponing childbearing beyond the teenage years would…

  6. Dexterous manipulation is poorer at older ages and is dissociated from decline of hand strength.

    PubMed

    Dayanidhi, Sudarshan; Valero-Cuevas, Francisco J

    2014-09-01

    The ability to dynamically control fingertip force vector magnitude and direction is critical for dexterous manipulation. We quantified the dynamic control of fingertip forces to examine how dexterous manipulation declines with age. The strength-dexterity (SD) test measures fingertip forces during compression of a slender spring prone to instability and buckling. The greatest sustained compression (designed to be under 3 N), and force dynamics therein, have been shown to be simple and quick measures of dynamic dexterous manipulation ability. We measured pinch strength and strength-dexterity test in a cross-sectional population of 98 people from 18 to 89 years of age. Dexterous manipulation ability is poorer at older ages, beginning in middle age (p < .001), with greater decline past 65 years of age. Fingertip force dynamics during spring compression and stabilization show a deterioration of neuromuscular control with age. Importantly, this novel detection of decline in dynamic manipulation ability is not correlated with, and thus cannot be entirely explained by, the known decline in pinch strength. We also measured standardized tests of dexterity in participants older than 45, and discuss how the strength-dexterity test uniquely captures features of sensorimotor capabilities for dexterous manipulation in this adult population. Starting in middle age, changes in the functional interactions among sensory, motor, and neural capabilities result in measurably poorer dynamic dexterous manipulation. This deterioration of neuromuscular control motivates and enables future studies to understand the physiological bases for this functional decline so critical to activities of daily living and quality of life. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. The impact of obesity on skeletal muscle strength and structure through adolescence to old age.

    PubMed

    Tomlinson, D J; Erskine, R M; Morse, C I; Winwood, K; Onambélé-Pearson, Gladys

    2016-06-01

    Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

  8. Laterality of handgrip strength: age- and physical training-related changes in Lithuanian schoolchildren and conscripts.

    PubMed

    Tutkuviene, Janina; Schiefenhövel, Wulf

    2013-06-01

    Laterality in handgrip strength was assessed by analyzing dynamometric data of the right and left hand in three samples of Lithuanian boys and girls aged 7-20 years. In addition, the influence of general physical training on the laterality of handgrip strength was explored in a sample of conscripts. A negative secular trend in handgrip strength of schoolchildren has been detected since 1965, and with increasing age, right-handedness has become more pronounced. Children that were ambidextrous (by grip strength) showed negative deviations in physical status more often than their right- or left-handed peers. During one year of physical training, the conscripts had a larger increase in grip strength of the left than in the right hand, and a marked shift in handgrip laterality toward left-handed and ambidextrous individuals was observed. The different impact of schooling and physical training on handgrip strength laterality might partly explain variations in the prevalence of handedness in different societies with divergent cultures and lifestyles (e.g., more or less sedentary). © 2013 New York Academy of Sciences.

  9. High early strength calcium phosphate bone cement: effects of dicalcium phosphate dihydrate and absorbable fibers.

    PubMed

    Burguera, Elena F; Xu, Hockin H K; Takagi, Shozo; Chow, Laurence C

    2005-12-15

    Calcium phosphate cement (CPC) sets in situ to form resorbable hydroxyapatite with chemical and crystallographic similarity to the apatite in human bones, hence it is highly promising for clinical applications. The objective of the present study was to develop a CPC that is fast setting and has high strength in the early stages of implantation. Two approaches were combined to impart high early strength to the cement: the use of dicalcium phosphate dihydrate with a high solubility (which formed the cement CPC(D)) instead of anhydrous dicalcium phosphate (which formed the conventional cement CPC(A)), and the incorporation of absorbable fibers. A 2 x 8 design was tested with two materials (CPC(A) and CPC(D)) and eight levels of cement reaction time: 15 min, 30 min, 1 h, 1.5 h, 2 h, 4 h, 8 h, and 24 h. An absorbable suture fiber was incorporated into cements at 25% volume fraction. The Gilmore needle method measured a hardening time of 15.8 min for CPC(D), five-fold faster than 81.5 min for CPC(A), at a powder:liquid ratio of 3:1. Scanning electron microscopy revealed the formation of nanosized rod-like hydroxyapatite crystals and platelet crystals in the cements. At 30 min, the flexural strength (mean +/- standard deviation; n = 5) was 0 MPa for CPC(A) (the paste did not set), (4.2 +/- 0.3) MPa for CPC(D), and (10.7 +/- 2.4) MPa for CPC(D)-fiber specimens, significantly different from each other (Tukey's at 0.95). The work of fracture (toughness) was increased by two orders of magnitude for the CPC(D)-fiber cement. The high early strength matched the reported strength for cancellous bone and sintered porous hydroxyapatite implants. The composite strength S(c) was correlated to the matrix strength S(m): S(c) = 2.16S(m). In summary, substantial early strength was imparted to a moldable, self-hardening and resorbable hydroxyapatite via two synergistic approaches: dicalcium phosphate dihydrate, and absorbable fibers. The new fast-setting and strong cement may help prevent

  10. Methadone metabolism by early gestational age placentas.

    PubMed

    Hieronymus, Todd Lewis; Nanovskaya, Tatiana N; Deshmukh, Sujal V; Vargas, Ricardo; Hankins, Gary D V; Ahmed, Mahmoud S

    2006-07-01

    The objective of this study was to identify the enzyme that metabolizes methadone in preterm placentas. Microsomal fractions were obtained from preterm (17 to 34 weeks) placentas (36 total; 12 per each gestational age group) and their activity in metabolizing methadone to 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) was determined. The enzyme catalyzing the reaction was identified by using chemical inhibitors selective for various cytochrome P450 isozymes and monoclonal antibodies raised against them. The metabolism of methadone by microsomes revealed saturation kinetics. Methadone was N-demethylated to EDDP by aromatase. The affinity of methadone to aromatase (apparent Km) did not change with gestation, but the activity of the enzyme (Vmax) increased and varied widely between individual placentas. Aromatase/CYP19 is the placental enzyme metabolizing methadone during pregnancy. The variability in enzyme activity among individuals should be reflected by the concentration of methadone in the fetal circulation and might be one of the factors affecting the incidence and intensity of neonatal abstinence syndrome.

  11. Physical Activity, Sedentary Time, and Bone Strength From Childhood to Early Adulthood: A Mixed Longitudinal HR-pQCT study.

    PubMed

    Gabel, Leigh; Macdonald, Heather M; Nettlefold, Lindsay; McKay, Heather A

    2017-03-22

    Bone strength is influenced by bone geometry, density, and bone microarchitecture, which adapt to increased mechanical loads during growth. Physical activity (PA) is essential for optimal bone strength accrual; however, less is known about how sedentary time influences bone strength and its determinants. Thus, our aim was to investigate the prospective associations between PA, sedentary time, and bone strength and its determinants during adolescence. We used HR-pQCT at distal tibia (8% site) and radius (7% site) in 173 girls and 136 boys (aged 9 to 20 years at baseline). We conducted a maximum of four annual measurements at the tibia (n = 785 observations) and radius (n = 582 observations). We assessed moderate-to-vigorous PA (MVPA) and sedentary time with accelerometers (ActiGraph GT1M). We aligned participants on maturity (years from age at peak height velocity) and fit a mixed-effects model adjusting for maturity, sex, ethnicity, leg muscle power, lean mass, limb length, dietary calcium, and MVPA in sedentary time models. MVPA was a positive independent predictor of bone strength (failure load [F.Load]) and bone volume fraction (BV/TV) at the tibia and radius, total area (Tt.Ar) and cortical porosity (Ct.Po) at the tibia, and negative predictor of load-to-strength ratio at the radius. Sedentary time was a negative independent predictor of Tt.Ar at both sites and Ct.Po at the tibia and a positive predictor of cortical thickness (Ct.Th), trabecular thickness (Tb.Th), and cortical bone mineral density (Ct.BMD) at the tibia. Bone parameters demonstrated maturity-specific associations with MVPA and sedentary time, whereby associations were strongest during early and mid-puberty. Our findings support the importance of PA for bone strength accrual and its determinants across adolescent growth and provide new evidence of a detrimental association of sedentary time with bone geometry but positive associations with microarchitecture. This study highlights maturity

  12. Using a Strengths Approach to Early Childhood Teacher Preparation in Child Protection Using Work-Integrated Education

    ERIC Educational Resources Information Center

    Fenton, Angela

    2013-01-01

    This paper explores a collaborative strengths-based approach to investing in pre-service early childhood teacher education in the area of child protection. The doctoral research of the author, which evaluated a Strengths Approach as a cross-sector tool for implementing change in early-childhood education and in doing so researched a potential…

  13. Motor effort training with low exercise intensity improves muscle strength and descending command in aging

    PubMed Central

    Jiang, Changhao; Ranganathan, Vinoth K.; Zhang, Junmei; Siemionow, Vlodek; Yue, Guang H.

    2016-01-01

    Abstract This study explored the effect of high mental effort training (MET) and conventional strength training (CST) on increasing voluntary muscle strength and brain signal associated with producing maximal muscle force in healthy aging. Twenty-seven older adults (age: 75 ± 7.9 yr, 8 women) were assigned into 1 of 3 groups: MET group—trained with low-intensity (30% maximal voluntary contraction [MVC]) physical exercise combined with MET, CST group—trained with high-intensity muscle contractions, or control (CTRL) group—no training of any kind. MET and CST lasted for 12 weeks (5 sessions/week). The participants’ elbow flexion strength of the right arm, electromyography (EMG), and motor activity-related cortical potential (MRCP) directly related to the strength production were measured before and after training. The CST group had the highest strength gain (17.6%, P <0.001), the MET group also had significant strength gain (13.8%, P <0.001), which was not statistically different from that of the CST group even though the exercise intensity for the MET group was only at 30% MVC level. The CTRL group did not have significant strength changes. Surprisingly, only the MET group demonstrated a significant augmentation in the MRCP (29.3%, P <0.001); the MRCP increase in CST group was at boarder-line significance level (12.11%, P = 0.061) and that for CTRL group was only 4.9% (P = 0.539). These results suggest that high mental effort training combined with low-intensity physical exercise is an effective method for voluntary muscle strengthening and this approach is especially beneficial for those who are physically weak and have difficulty undergoing conventional strength training. PMID:27310942

  14. Motor effort training with low exercise intensity improves muscle strength and descending command in aging.

    PubMed

    Jiang, Changhao; Ranganathan, Vinoth K; Zhang, Junmei; Siemionow, Vlodek; Yue, Guang H

    2016-06-01

    This study explored the effect of high mental effort training (MET) and conventional strength training (CST) on increasing voluntary muscle strength and brain signal associated with producing maximal muscle force in healthy aging. Twenty-seven older adults (age: 75 ± 7.9 yr, 8 women) were assigned into 1 of 3 groups: MET group-trained with low-intensity (30% maximal voluntary contraction [MVC]) physical exercise combined with MET, CST group-trained with high-intensity muscle contractions, or control (CTRL) group-no training of any kind. MET and CST lasted for 12 weeks (5 sessions/week). The participants' elbow flexion strength of the right arm, electromyography (EMG), and motor activity-related cortical potential (MRCP) directly related to the strength production were measured before and after training. The CST group had the highest strength gain (17.6%, P <0.001), the MET group also had significant strength gain (13.8%, P <0.001), which was not statistically different from that of the CST group even though the exercise intensity for the MET group was only at 30% MVC level. The CTRL group did not have significant strength changes. Surprisingly, only the MET group demonstrated a significant augmentation in the MRCP (29.3%, P <0.001); the MRCP increase in CST group was at boarder-line significance level (12.11%, P = 0.061) and that for CTRL group was only 4.9% (P = 0.539). These results suggest that high mental effort training combined with low-intensity physical exercise is an effective method for voluntary muscle strengthening and this approach is especially beneficial for those who are physically weak and have difficulty undergoing conventional strength training.

  15. The Association of Kindergarten Entry Age with Early Literacy Outcomes

    ERIC Educational Resources Information Center

    Huang, Francis L.; Invernizzi, Marcia A.

    2012-01-01

    The authors investigated whether age at kindergarten entry was associated with early literacy achievement gaps and if these gaps persisted over time. Using the kindergarten age eligibility cutoff date, they created 2 groups of students who represented the oldest and youngest children in a cohort of students in high-poverty, low-performing schools.…

  16. Early Middle Ear Effusion and Language at Age Seven

    ERIC Educational Resources Information Center

    Johnson, Dale L.; McCormick, David P.; Baldwin, Constance D.

    2008-01-01

    This study examined the relation of middle ear effusion (MEE) in the first 3 years of life to language outcomes at age seven. It was hypothesized, on the basis of a literature review, that (1) a low, but positive relation between early MEE and language measures in general will be observed at age seven, and (2) major effects will be demonstrated…

  17. Early Middle Ear Effusion and Language at Age Seven

    ERIC Educational Resources Information Center

    Johnson, Dale L.; McCormick, David P.; Baldwin, Constance D.

    2008-01-01

    This study examined the relation of middle ear effusion (MEE) in the first 3 years of life to language outcomes at age seven. It was hypothesized, on the basis of a literature review, that (1) a low, but positive relation between early MEE and language measures in general will be observed at age seven, and (2) major effects will be demonstrated…

  18. Early-Life Intelligence Predicts Midlife Biological Age.

    PubMed

    Schaefer, Jonathan D; Caspi, Avshalom; Belsky, Daniel W; Harrington, Honalee; Houts, Renate; Israel, Salomon; Levine, Morgan E; Sugden, Karen; Williams, Benjamin; Poulton, Richie; Moffitt, Terrie E

    2016-11-01

    Early-life intelligence has been shown to predict multiple causes of death in populations around the world. This finding suggests that intelligence might influence mortality through its effects on a general process of physiological deterioration (i.e., individual variation in "biological age"). We examined whether intelligence could predict measures of aging at midlife before the onset of most age-related disease. We tested whether intelligence assessed in early childhood, middle childhood, and midlife predicted midlife biological age in members of the Dunedin Study, a population-representative birth cohort. Lower intelligence predicted more advanced biological age at midlife as captured by perceived facial age, a 10-biomarker algorithm based on data from the National Health and Nutrition Examination Survey (NHANES), and Framingham heart age (r = 0.1-0.2). Correlations between intelligence and telomere length were less consistent. The associations between intelligence and biological age were not explained by differences in childhood health or parental socioeconomic status, and intelligence remained a significant predictor of biological age even when intelligence was assessed before Study members began their formal schooling. These results suggest that accelerated aging may serve as one of the factors linking low early-life intelligence to increased rates of morbidity and mortality. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Effects of Age, Gender and Educational Background on Strength of Motivation for Medical School

    ERIC Educational Resources Information Center

    Kusurkar, Rashmi; Kruitwagen, Cas; ten Cate, Olle; Croiset, Gerda

    2010-01-01

    The aim of this study was to determine the effects of selection, educational background, age and gender on strength of motivation to attend and pursue medical school. Graduate entry (GE) medical students (having Bachelor's degree in Life Sciences or related field) and Non-Graduate Entry (NGE) medical students (having only completed high school),…

  20. Effects of Age, Gender and Educational Background on Strength of Motivation for Medical School

    ERIC Educational Resources Information Center

    Kusurkar, Rashmi; Kruitwagen, Cas; ten Cate, Olle; Croiset, Gerda

    2010-01-01

    The aim of this study was to determine the effects of selection, educational background, age and gender on strength of motivation to attend and pursue medical school. Graduate entry (GE) medical students (having Bachelor's degree in Life Sciences or related field) and Non-Graduate Entry (NGE) medical students (having only completed high school),…

  1. Adhesion strategy and early bond strengths of glass-fiber posts luted into root canals.

    PubMed

    Faria-e-Silva, André Luis; Mendonça, Adriano Augusto Melo; Garcez, Rosa Maria Viana de Bragança; Oliveira, Aline da Silva de; Moreira, Andressa Goicochea; Moraes, Rafael Ratto de

    2012-01-01

    This study investigated the effect of coinitiator solutions and self-adhesive resin cement on the early retention of glass-fiber posts. Cylindrical glass-fiber posts were luted into 40 incisor roots with different adhesion strategies (n = 10): SB2, Single Bond 2 + conventional resin cement (RelyX ARC); AP, Scotchbond Multipurpose Plus (SBMP) activator + primer + ARC; APC, SBMP activator + primer + catalyst + ARC; and UNI, self-adhesive cement (RelyX Unicem). Pull-out bond strength results at 10 min after cementation showed APC > UNI > SB2 = AP (P < 0.05). The adhesion strategy significantly affected early bonding to root canals.

  2. Language development of internationally adopted children: Adverse early experiences outweigh the age of acquisition effect.

    PubMed

    Rakhlin, Natalia; Hein, Sascha; Doyle, Niamh; Hart, Lesley; Macomber, Donna; Ruchkin, Vladislav; Tan, Mei; Grigorenko, Elena L

    2015-01-01

    We compared English language and cognitive skills between internationally adopted children (IA; mean age at adoption=2.24, SD=1.8) and their non-adopted peers from the US reared in biological families (BF) at two time points. We also examined the relationships between outcome measures and age at initial institutionalization, length of institutionalization, and age at adoption. On measures of general language, early literacy, and non-verbal IQ, the IA group performed significantly below their age-peers reared in biological families at both time points, but the group differences disappeared on receptive vocabulary and kindergarten concept knowledge at the second time point. Furthermore, the majority of children reached normative age expectations between 1 and 2 years post-adoption on all standardized measures. Although the age at adoption, age of institutionalization, length of institutionalization, and time in the adoptive family all demonstrated significant correlations with one or more outcome measures, the negative relationship between length of institutionalization and child outcomes remained most robust after controlling for the other variables. Results point to much flexibility and resilience in children's capacity for language acquisition as well as the potential primacy of length of institutionalization in explaining individual variation in IA children's outcomes. (1) Readers will be able to understand the importance of pre-adoption environment on language and early literacy development in internationally adopted children. (2) Readers will be able to compare the strength of the association between the length of institutionalization and language outcomes with the strength of the association between the latter and the age at adoption. (3) Readers will be able to understand that internationally adopted children are able to reach age expectations on expressive and receptive language measures despite adverse early experiences and a replacement of their first

  3. Comparison of skeletal muscle strength between cardiac patients and age-matched healthy controls

    PubMed Central

    Baum, K.; Hildebrandt, U.; Edel, K.; Bertram, R.; Hahmann, H.; Bremer, F.J.; Böhmen, S.; Kammerlander, C.; Serafin, M.; Rüther, Th.; Miche, E.

    2009-01-01

    The purpose of the present study was to compare muscular strength of knee extensors and arm flexor muscles of cardiac patients (n = 638) and healthy controls (n = 961) in different age groups. Isometric torques were measured in a sitting position with the elbow, hip, and knee flexed to 900. For statistical analysis, age groups were pooled in decades from the age of 30 to 90 years. Additionally, the influence of physical lifestyle prior to disease on muscular strength was obtained in the patients. For statistical analysis three-way ANOVA (factors age, gender, and physical activity level) was used. Both in patients and in controls a significant age-dependent decline in maximal torque could be observed for arm flexors and knee extensors. Maximal leg extensor muscle showed statistically significant differences between healthy controls and cardiac patients as well as between subgroups of patients: Physically inactive patients showed lowest torques (male: 148 ± 18 Nm; female: 82 ± 25 Nm) while highest values were measured in control subjects (male: 167 ± 16 Nm; female: 93 ± 17 Nm). In contrast, arm flexor muscles did not show any significant influence of health status or sports history. This qualitative difference between weight-bearing leg muscles and the muscle group of the upper extremity suggest that lower skeletal muscle strength in heart patients is mainly a consequence of selective disuse of leg muscles rather than any pathological skeletal muscle metabolism. Since a certain level of skeletal muscle strength is a prerequisite to cope with everyday activities, strength training is recommended as an important part of cardiac rehabilitation. PMID:19584952

  4. Comparison of skeletal muscle strength between cardiac patients and age-matched healthy controls.

    PubMed

    Baum, K; Hildebrandt, U; Edel, K; Bertram, R; Hahmann, H; Bremer, F J; Böhmen, S; Kammerlander, C; Serafin, M; Rüther, Th; Miche, E

    2009-07-06

    The purpose of the present study was to compare muscular strength of knee extensors and arm flexor muscles of cardiac patients (n = 638) and healthy controls (n = 961) in different age groups. Isometric torques were measured in a sitting position with the elbow, hip, and knee flexed to 90(0). For statistical analysis, age groups were pooled in decades from the age of 30 to 90 years. Additionally, the influence of physical lifestyle prior to disease on muscular strength was obtained in the patients. For statistical analysis three-way ANOVA (factors age, gender, and physical activity level) was used.Both in patients and in controls a significant age-dependent decline in maximal torque could be observed for arm flexors and knee extensors. Maximal leg extensor muscle showed statistically significant differences between healthy controls and cardiac patients as well as between subgroups of patients: Physically inactive patients showed lowest torques (male: 148 +/- 18 Nm; female: 82 +/- 25 Nm) while highest values were measured in control subjects (male: 167 +/- 16 Nm; female: 93 +/- 17 Nm). In contrast, arm flexor muscles did not show any significant influence of health status or sports history.This qualitative difference between weight-bearing leg muscles and the muscle group of the upper extremity suggest that lower skeletal muscle strength in heart patients is mainly a consequence of selective disuse of leg muscles rather than any pathological skeletal muscle metabolism. Since a certain level of skeletal muscle strength is a prerequisite to cope with everyday activities, strength training is recommended as an important part of cardiac rehabilitation.

  5. Rejuvenation of the aged muscle stem cell population restores strength to injured aged muscles

    PubMed Central

    Cosgrove, Benjamin D.; Gilbert, Penney M.; Porpiglia, Ermelinda; Mourkioti, Foteini; Lee, Steven P.; Corbel, Stephane Y.; Llewellyn, Michael E.; Delp, Scott L.; Blau, Helen M.

    2014-01-01

    The aged suffer from progressive muscle weakness and regenerative failure. We demonstrate that muscle regeneration is impaired with aging due in part to a cell-autonomous functional decline in skeletal muscle stem cells (MuSCs). Two-thirds of aged MuSCs are intrinsically defective relative to young MuSCs, with reduced capacity to repair myofibers and repopulate the stem cell reservoir in vivo following transplantation due to a higher incidence of cells that express senescence markers and that have elevated p38α/β MAPK activity. We show that these limitations cannot be overcome by transplantation into the microenvironment of young recipient muscles. In contrast, subjecting the aged MuSC population to transient inhibition of p38α/β in conjunction with culture on soft hydrogel substrates rapidly expands the residual functional aged MuSC population, rejuvenating its potential for regeneration, serial transplantation, and strengthening damaged muscles of aged mice. These findings reveal a synergy between biophysical and biochemical cues that provides a paradigm for a localized autologous muscle stem cell therapy in aged individuals. PMID:24531378

  6. Test-Retest Reliability of Isokinetic Knee Strength Measurements in Children Aged 8 to 10 Years.

    PubMed

    Fagher, Kristina; Fritzson, Annelie; Drake, Anna Maria

    Isokinetic dynamometry is a useful tool to objectively assess muscle strength of children and adults in athletic and rehabilitative settings. This study examined test-retest reliability of isokinetic knee strength measurements in children aged 8 to 10 years and defined limits for the minimum difference (MD) in strength that indicates a clinically important change. Isokinetic knee strength measurements (using the Biodex System 4) in children will provide reliable results. Descriptive laboratory study. In 22 healthy children, 5 maximal concentric (CON) knee extensor (KE) and knee flexor (KF) contractions at 2 angular velocities (60 deg/s and 180 deg/s) and 5 maximal eccentric (ECC) KE/KF contractions at 60 deg/s were assessed 7 days apart. The intraclass correlation coefficient (ICC2.1) was used to examine relative reliability, and the MD was calculated on the basis of standard error of measurement. ICCs for CON KE/KF peak torque measurements were fair to excellent (range, 0.49-0.81). The MD% values for CON KE and KF ranged from 31% to 37% at 60 deg/s and from 34% to 39% at 180 deg/s. ICCs in the ECC mode were good (range, 0.60-0.70), but associated MD% values were high (>50%). There was no systematic error for CON KE/KF and ECC KE strength measurements at 60 deg/s, but systematic error was found for all other measurements. The dynamometer provides a reliable analysis of isokinetic CON knee strength measurements at 60 deg/s in children aged 8 to 10 years. Measurements at 180 deg/s and in the ECC mode were not reliable, indicating a need for more familiarization prior to testing. The MD values may help clinicians to determine whether a change in knee strength is due to error or intervention.

  7. Muscle strength and quality of life in patients with childhood cancer at early phase of primary treatment.

    PubMed

    Deisenroth, Anne; Söntgerath, Regine; Schuster, Anne Judith; von Busch, Christine; Huber, Gerhard; Eckert, Katharina; Kulozik, Andreas E; Wiskemann, Joachim

    2016-09-01

    Cancer- and treatment-related side effects in patients with childhood cancer may cause limitations in motor performance affecting activities of daily living (ADLs). Data focusing on long-term effects are available, but little is known with regard to the short-term perspective. Therefore, the purpose of this study was to assess muscle strength performance and quality of life (QoL) in children and adolescents with cancer at the beginning of primary treatment. Forty children and adolescents aged 5-18 years (mean: 11.39 ± 4.08 years) with different types of childhood cancer were enrolled. On average 36 ± 20.5 days after diagnosis, strength performance in 7 muscle groups was assessed by handheld dynamometry. KINDL questionnaires were completed to evaluate QoL (children's self-report and parents' report). All parameters were compared with age- and gender-matched reference values. Patients with childhood cancer showed significantly lower strength values in all muscle groups (P < .01) compared with age- and gender-matched controls. Most affected were the lower extremities, with a -57.1% ± 10.4%, median: -59.2%, minimum: -75.4%, maximum: -41.4% percentage deviation in knee flexion from healthy peers. Children themselves and parents assessed total QoL significantly below age- and gender-matched reference values (P < .01). Correlation between elbow flexion and self-reported QoL was detected. Broader correlations were found for the parents' report. Muscle weakness and decreased QoL in children and adolescents seem to persist already at the beginning of anticancer treatment. This underlines the need of counteracting measures, such as exercise intervention programs, starting as early as possible during the treatment process. Efforts on this topic are currently being carried out by our group.

  8. Leg strength declines with advancing age despite habitual endurance exercise in active older adults.

    PubMed

    Marcell, Taylor J; Hawkins, Steven A; Wiswell, Robert A

    2014-02-01

    Age-associated loss of muscle mass (sarcopenia) and strength (dynapenia) is associated with a loss of independence that contributes to falls, fractures, and nursing home admissions, whereas regular physical activity has been suggested to offset these losses. The purpose of this study was to evaluate the effect of habitual endurance exercise on muscle mass and strength in active older adults. A longitudinal analysis of muscle strength (≈4.8 years apart) was performed on 59 men (age at start of study: 58.6 ± 7.3 years) and 35 women (56.9 ± 8.2 years) who used endurance running as their primary mode of exercise. There were no changes in fat-free mass although body fat increased minimally (1.0-1.5%). Training volume (km·wk, d·wk) decreased in both the men and women. There was a significant loss of both isometric knee extension (≈5% per year) and knee flexion (≈3.6% per year) strength in both the men and women. However, there was no significant change in either isokinetic concentric or eccentric torque of the knee extensors. Our data demonstrated a significant decline in isometric knee extensor and knee flexor strength although there were no changes in body mass in this group of very active older men and women. Our data support newer exercise guidelines for older Americans suggesting resistance training be an integral component of a fitness program and that running alone was not sufficient to prevent the loss in muscle strength (dynapenia) with aging.

  9. Age specific isokinetic glenohumeral internal and external rotation strength in elite junior tennis players.

    PubMed

    Ellenbecker, T; Roetert, E P

    2003-03-01

    The high incidence of overuse shoulder injuries in elite junior tennis players is often attributed to both the high repetitive stresses inherent in the game, as well as muscular imbalances in the humeral rotators. The purpose of this study was to isokinetically measure concentric glenohumeral joint internal and external rotation strength, to develop a bilateral descriptive profile in elite junior tennis players across two age ranges. One hundred forty seven elite junior players between the ages of 12 and 21 were bilaterally tested on a Cybex isokinetic dynamometer with 90 degrees of abduction. Players were analysed in two groups (12-17 and 18-21 years of age), using isokinetic variables of peak torque and work relative to body weight. Data analysis consisted of ANOVAs, with dependent t-tests used for post-hoc testing where main effect differences were identified. Results indicated no significant main effect difference in the isokinetic relative parameters between the two age groups (p > .01). Significantly greater (p < .001) dominant arm internal rotation was measured in both groups for both males and females, with no significant difference in external rotation strength measured between extremities in either age group. These data show specific adaptations in shoulder strength and identify a relative muscular imbalance between the internal and external rotators on the dominant arm of elite junior tennis players. Normative data presented in this study can assist clinicians and researchers in interpreting isokinetic test results in elite junior tennis players.

  10. Learning your own strength: winner and loser effects should change with age and experience

    PubMed Central

    Fawcett, Tim W.; Johnstone, Rufus A.

    2010-01-01

    Winner and loser effects, in which the outcome of an aggressive encounter influences the tendency to escalate future conflicts, have been documented in many taxa, but we have limited understanding of why they have evolved. One possibility is that individuals use previous victories and defeats to assess their fighting ability relative to others. We explored this idea by modelling a population of strong and weak individuals that do not know their own strength, but keep track of how many fights they have won. Under these conditions, adaptive behaviour generates clear winner and loser effects: individuals who win fights should escalate subsequent conflicts, whereas those who lose should retreat from aggressive opponents. But these effects depend strongly on age and experience. Young, naive individuals should show highly aggressive behaviour and pronounced loser effects. For these inexperienced individuals, fighting is especially profitable because it yields valuable information about their strength. Aggression should then decline as an individual ages and gains experience, with those who lose fights becoming more submissive. Older individuals, who have a better idea of their own strength, should be more strongly influenced by victories than losses. In conclusion, we predict that both aggressiveness and the relative magnitude of winner and loser effects should change with age, owing to changes in how individuals perceive their own strength. PMID:20053644

  11. DNA methylation, ageing and the influence of early life nutrition.

    PubMed

    Lillycrop, Karen A; Hoile, Samuel P; Grenfell, Leonie; Burdge, Graham C

    2014-08-01

    It is well established that genotype plays an important role in the ageing process. However, recent studies have suggested that epigenetic mechanisms may also influence the onset of ageing-associated diseases and longevity. Epigenetics is defined as processes that induce heritable changes in gene expression without a change in the DNA nucleotide sequence. The major epigenetic mechanisms are DNA methylation, histone modification and non-coding RNA. Such processes are involved in the regulation of tissue-specific gene expression, cell differentiation and genomic imprinting. However, epigenetic dysregulation is frequently seen with ageing. Relatively little is known about the factors that initiate such changes. However, there is emerging evidence that the early life environment, in particular nutrition, in early life can induce long-term changes in DNA methylation resulting in an altered susceptibility to a range of ageing-associated diseases. In this review, we will focus on the changes in DNA methylation that occur during ageing; their role in the ageing process and how early life nutrition can modulate DNA methylation and influence longevity. Understanding the mechanisms by which diet in early life can influence the epigenome will be crucial for the development of preventative and intervention strategies to increase well-being in later life.

  12. Internationally adopted children in the early school years: relative strengths and weaknesses in language abilities.

    PubMed

    Glennen, Sharon

    2015-01-01

    This study aimed to determine the relative strengths and weaknesses in language and verbal short-term memory abilities of school-age children who were adopted from Eastern Europe. Children adopted between 1;0 and 4;11 (years;months) of age were assessed with the Clinical Evaluation of Language Fundamentals-Preschool, Second Edition (CELF-P2) and the Clinical Evaluation of Language Fundamentals, Fourth Edition (CELF-4) at age 5 and ages 6-7. Language composites and subtests were compared across time. All CELF-P2 and CELF-4 mean scores fell in the average range. Receptive composites were 102.74 and 103.86, and expressive composites were 100.58 and 98.42, at age 5 and ages 6-7, respectively. Age of adoption did not correlate to test scores. At ages 6-7, receptive language, sentence formulation, and vocabulary were areas of strength, with subtest scores significantly better than test norms. Verbal short-term memory and expressive grammar subtest scores were within the average range but significantly worse than test norms. A high percentage of children scored 1 standard deviation below the mean on these 2 subtests (27.3%-34.1%). Eastern European adoptees had average scores on a variety of language tests. Vocabulary was a relative strength; enriching the environment substantially improved this language area. Verbal short-term memory and expressive grammar were relative weaknesses. Children learning a language later in life may have difficulty with verbal short-term memory, which leads to weaknesses in expressive syntax and grammar.

  13. Effects of age, gender and educational background on strength of motivation for medical school.

    PubMed

    Kusurkar, Rashmi; Kruitwagen, Cas; ten Cate, Olle; Croiset, Gerda

    2010-08-01

    The aim of this study was to determine the effects of selection, educational background, age and gender on strength of motivation to attend and pursue medical school. Graduate entry (GE) medical students (having Bachelor's degree in Life Sciences or related field) and Non-Graduate Entry (NGE) medical students (having only completed high school), were asked to fill out the Strength of Motivation for Medical School (SMMS) questionnaire at the start of medical school. The questionnaire measures the willingness of the medical students to pursue medical education even in the face of difficulty and sacrifice. GE students (59.64 ± 7.30) had higher strength of motivation as compared to NGE students (55.26 ± 8.33), so did females (57.05 ± 8.28) as compared to males (54.30 ± 8.08). 7.9% of the variance in the SMMS scores could be explained with the help of a linear regression model with age, gender and educational background/selection as predictor variables. Age was the single largest predictor. Maturity, taking developmental differences between sexes into account, was used as a predictor to correct for differences in the maturation of males and females. Still, the gender differences prevailed, though they were reduced. Pre-entrance educational background and selection also predicted the strength of motivation, but the effect of the two was confounded. Strength of motivation appears to be a dynamic entity, changing primarily with age and maturity and to a small extent with gender and experience.

  14. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns

    PubMed Central

    Lameira, Deborah Pacheco; Silva, Wilkens Aurélio Buarque e; Silva, Frederico Andrade e; De Souza, Grace M.

    2015-01-01

    The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37°C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength. PMID:26576423

  15. Subjective Age in Early Adolescence: Relationships with Chronological Age, Pubertal Timing, Desired Age, and Problem Behaviors

    ERIC Educational Resources Information Center

    Hubley, Anita M.; Arim, Rubab G.

    2012-01-01

    Subjective age generally refers to the age that one feels. In a cross-sectional questionnaire study of 245 adolescents ages 10-14 years, we examined (a) whether, and when, a cross-over in subjective age occurs, (b) differences in subjective age among pubertal timing groups, (c) correlations between subjective age and each of desired age and five…

  16. Subjective Age in Early Adolescence: Relationships with Chronological Age, Pubertal Timing, Desired Age, and Problem Behaviors

    ERIC Educational Resources Information Center

    Hubley, Anita M.; Arim, Rubab G.

    2012-01-01

    Subjective age generally refers to the age that one feels. In a cross-sectional questionnaire study of 245 adolescents ages 10-14 years, we examined (a) whether, and when, a cross-over in subjective age occurs, (b) differences in subjective age among pubertal timing groups, (c) correlations between subjective age and each of desired age and five…

  17. Early detection of age related macular degeneration: current status.

    PubMed

    Schwartz, Roy; Loewenstein, Anat

    2015-01-01

    Early diagnosis and treatment of choroidal neovascularization (CNV), a main cause of severe vision loss in age related macular degeneration (AMD), is crucial in order to preserve vision and the quality of life of patients. This review summarizes current literature on the subject of early detection of CNV, both in the clinic setting and mainly in the patient's home. New technologies are evolving to allow for earlier detection and thus vision preservation in AMD patients.

  18. Repair Bond Strength of Aged Resin Composite after Different Surface and Bonding Treatments

    PubMed Central

    Wendler, Michael; Belli, Renan; Panzer, Reinhard; Skibbe, Daniel; Petschelt, Anselm; Lohbauer, Ulrich

    2016-01-01

    The aim of this study was to compare the effect of different mechanical surface treatments and chemical bonding protocols on the tensile bond strength (TBS) of aged composite. Bar specimens were produced using a nanohybrid resin composite and aged in distilled water for 30 days. Different surface treatments (diamond bur, phosphoric acid, silane, and sandblasting with Al2O3 or CoJet Sand), as well as bonding protocols (Primer/Adhesive) were used prior to application of the repair composite. TBS of the specimens was measured and the results were analyzed using analysis of variance (ANOVA) and the Student–Newman–Keuls test (α = 0.05). Mechanically treated surfaces were characterized under SEM and by profilometry. The effect of water aging on the degree of conversion was measured by means of FTIR-ATR spectroscopy. An important increase in the degree of conversion was observed after aging. No significant differences in TBS were observed among the mechanical surface treatments, despite variations in surface roughness profiles. Phosphoric acid etching significantly improved repair bond strength values. The cohesive TBS of the material was only reached using resin bonding agents. Application of an intermediate bonding system plays a key role in achieving reliable repair bond strengths, whereas the kind of mechanical surface treatment appears to play a secondary role. PMID:28773669

  19. The effect of aging, temperature and brine composition on the mechanical strength of chalk

    NASA Astrophysics Data System (ADS)

    Korsnes, Reidar Inge; Nermoen, Anders; Stødle, Trond; Vika Storm, Eirik; Vadla Madland, Merete

    2014-05-01

    Chalk strength has been of great focus for several research communities since the 1980s when the Ekofisk subsidence problem was discovered. Sea water injection was initiated in 1987 to improve the oil production and to re-pressurize the reservoirs to halt the subsidence. The oil production was improved significantly, but the reservoir compaction in the water saturated regions continued, in contrast to the regions with no water breakthrough. This observation indicates a water weakening effect of the chalk. Extensive studies have been performed during the last decades to enlighten how the brine chemistry alters the rock mechanical properties. These studies have shown that the elastic bulk modulus, yield strength, creep and the deformation rate at constant stress conditions depend on the pore fluid composition. In general, the injected brine is in non-equilibrium with the rock surface inducing alteration of the rock mineralogy. In this study we examined two aspects of the mechanical strength, namely the bulk modulus and the onset of yield during hydrostatic stress loading with 0.7 MPa pore pressure. The test program consisted of aged and un-aged cores, ambient and 130°C test temperature, and four brine compositions: MgCl2, NaCl, Na2SO4, and synthetic sea water (SSW) at ion strengths of 0.657 M. The aging was performed by submerging saturated cores in a closed container with the respective test brine for three weeks at 130°C. Un-aged cores were saturated the same day as they were tested. For each brine composition we present four test setups; (a) aged and tested at 130°C, (b) aged and tested at ambient temperature, (c) un-aged and tested at 130°C, and (d) un-aged and tested at ambient conditions. The main results from our study are: 1. By using NaCl and MgCl2 as saturating brines, neither the test temperature nor the aging procedure affected the yield stress and bulk modulus significantly. 2. Using Na2SO4, the yield point and bulk moduli were reduced if the core

  20. A Study of Bar Strengths in Early-Type Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Buta, Ronald J.; Laurikainen, Eija; Salo, Heikki; Knapen, Johan H.

    2009-02-01

    Angular momentum exchange between a bar and a massive halo is thought to be responsible for producing strong bars in disk galaxies (Athanassoula, 2003), while gas transport to the center is believed to weaken or even dissolve bars (Bournaud and Combes 2002). We are carrying out a systematic survey of early-type disk galaxies with the main emphasis to derive the distribution of their bar strengths and to examine their Fourier amplitude properties. We propose to use FLAMINGOS with the KPNO 2.1m to obtain 2.2(micron) K_s-band observations of 16 galaxies for the ``Near-Infrared S0 Survey", a project already in progress to measure the bulge, disk, and bar properties of a statistically well-defined sample of 184 galaxies in the type range S0^- to Sa, including some possibly mis-classified elliptical galaxies. The principal goals of the survey, which was started 5 years ago and is now 90% completed, are to allow us to (1) compare relative Fourier near- IR intensity profiles of observed early-type galaxy bars with equivalent Fourier mass profiles of various Athanassoula models; (2) derive the distribution of bar strengths for the early-type sample and compare it with the known distribution for spirals; and (3) examine the properties of bulges and disks in early-type galaxies in order to better understand the origin of bulges (classical verus pseudo) in such galaxies. Our study is the first attempt to quantify bar strength in S0 galaxies. We are asking for enough KPNO 2.1m time to help complete our survey.

  1. Effects of age and regular exercise on muscle strength and endurance.

    PubMed

    Laforest, S; St-Pierre, D M; Cyr, J; Gayton, D

    1990-01-01

    Twenty male and 20 female non-professional tennis players were classified into two different age groups (n = 10 per group): young active men (30.4 +/- 3.3 years), young active women (27.5 +/- 4.3 years), elderly active men (64.4 +/- 3.7 years), and elderly active women (65.3 +/- 4.5 years). These individuals were matched (n = 10 per group) according to sex, age, height and mass to sedentary individuals of the same socio-economical background: young sedentary men (29.2 +/- 3.4 years), young sedentary women (25.6 +/- 4.4 years), elderly sedentary men (65.2 +/- 3.2 years) and elderly sedentary women (65.6 +/- 4.4 years). An isokinetic dynamometer was used to measure the strength of the knee extensors and flexors (two separate occasions) and the endurance of the extensors. Vastus lateralis electromyogram (EMG) was measured concomitantly. Significant sex, age and exercise effects (P less than 0.001) were observed for peak torque of both muscle groups. The effect of age on extensor strength was more pronounced at high speeds where men were also able to generate larger relative torques than women. No age or sex effects were noted for muscle endurance. However, muscles of active individuals demonstrated a greater resistance to fatigue than those of sedentary individuals. In conclusion, men were found to be stronger than women, age was associated with a decrease in muscle strength, but not of muscle endurance, and tennis players were stronger and had muscles that were more resistant to fatigue than their sedentary pairs in both age groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Assessment of handgrip strength in preschool children aged 3 to 5 years.

    PubMed

    Sanchez-Delgado, G; Cadenas-Sanchez, C; Mora-Gonzalez, J; Martinez-Tellez, B; Chillón, P; Löf, M; Ortega, F B; Ruiz, J R

    2015-11-01

    We investigated whether there is an optimal grip span for determining the maximum handgrip strength in preschool children and if it is influenced by gender, age, or hand size. A total of 292 preschool children (3-5 years; 59.2% boys) carried out the handgrip strength test with different grip spans (4.0, 4.5, 5.0, 5.5, and 6.0 cm). The hand size was also measured. We also determined the reliability of the optimal grip span in another group of children (n = 56, 57% boys) who did the test twice, with a 3-hour difference between tests. The results showed that 4.0 cm is the optimal grip span to determine the maximum handgrip strength in preschool children. This result applied to both genders, all age groups, and hand sizes. Paired t-tests showed no significant differences between test and retest. These findings may guide clinicians and researchers in selecting the optimal grip span when measuring handgrip strength in preschool children.Level IV. © The Author(s) 2015.

  3. Alpha plus beta annealed and aged Ti-15 Mo alloy for high strength implant applications.

    PubMed

    Disegi, John A; Roach, Michael D; McMillan, Rod D; Shultzabarger, Brian T

    2016-07-04

    Management of femur fractures requires titanium alloy implants that provide a good combination of static strength and ductility plus sufficient high cycle fatigue strength to resist repetitive loading. A research program was initiated to determine whether aging treatments could increase the strength of alpha + beta Ti-15Mo while maintaining acceptable tensile ductility. A pilot heat treating study indicated the best combination of strength and ductility was obtained using an α + β annealing temperature of 705°C ± 10°C followed by an aging treatment of 482°C ± 10°C. EBSD data for four suppliers revealed that the alpha phase ratios ranged from 16.3% to 18.6% and the beta phase ratios ranged from 81.4% to 83.7%. Mean beta grain size diameters ranged between 1.42 and 1.78 µm. Tensile testing qualification data from four suppliers was statistically analyzed and reviewed. Minimum reproducible tensile values were established and incorporated into ASTM F2066-13 implant material standard. Cantilever fatigue testing was performed with proximal femoral nail implants that were fabricated into fully finished implant constructs. Fatigue results for 125°, 130°, and 135° implant constructs met the acceptance criteria regarding the fatigue runout load limits and failure modes that were identified. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  4. Strength Properties of Aged Poled Lead Zirconate Titanate Subjected to Electromechanical Loadings

    SciTech Connect

    Zhang, Kewei; Zeng, Fan W; Wang, Hong; Lin, Hua-Tay

    2012-01-01

    Electric field and aging time are two important factors that affect the mechanical strength and long-term reliability of lead zirconate titanate or PZT actuators. In the present work, a commercial PZT-5A aged four years was examined using ball-on-ring (BoR) mechanical testing under coupled electric fields. The electric field range of -3E{sub c} to +3E{sub c} (E{sub c}, coercive electric field) was studied (i.e., -3E{sub c}, -E{sub c}, 0, +E{sub c}, +2E{sub c}, and +3E{sub c}) with a controlled electric loading path. A Weibull distribution was used to interpret the mechanical strength data. With an electric field preloaded from 0 to -3E{sub c}, it was found that subsequent increases in the electric field resulted in an asymmetrical V-shaped curve of mechanical strength against the electric field. The bottom of the V curve was located near the zero electric field level. Microscopy analysis showed that pores were the strength limiter for the tested PZT under electromechanical loadings.

  5. Analysis, prediction, and case studies of early-age cracking in bridge decks

    NASA Astrophysics Data System (ADS)

    ElSafty, Adel; Graeff, Matthew K.; El-Gharib, Georges; Abdel-Mohti, Ahmed; Mike Jackson, N.

    2016-06-01

    Early-age cracking can adversely affect strength, serviceability, and durability of concrete bridge decks. Early age is defined as the period after final setting, during which concrete properties change rapidly. Many factors can cause early-age bridge deck cracking including temperature change, hydration, plastic shrinkage, autogenous shrinkage, and drying shrinkage. The cracking may also increase the effect of freeze and thaw cycles and may lead to corrosion of reinforcement. This research paper presents an analysis of causes and factors affecting early-age cracking. It also provides a tool developed to predict the likelihood and initiation of early-age cracking of concrete bridge decks. Understanding the concrete properties is essential so that the developed tool can accurately model the mechanisms contributing to the cracking of concrete bridge decks. The user interface of the implemented computer Excel program enables the user to input the properties of the concrete being monitored. The research study and the developed spreadsheet were used to comprehensively investigate the issue of concrete deck cracking. The spreadsheet is designed to be a user-friendly calculation tool for concrete mixture proportioning, temperature prediction, thermal analysis, and tensile cracking prediction. The study also provides review and makes recommendations on the deck cracking based mainly on the Florida Department of Transportation specifications and Structures Design Guidelines, and Bridge Design Manuals of other states. The results were also compared with that of other commercially available software programs that predict early-age cracking in concrete slabs, concrete pavement, and reinforced concrete bridge decks. The outcome of this study can identify a set of recommendations to limit the deck cracking problem and maintain a longer service life of bridges.

  6. Effects of age and dietary soybean oil level on eggshell quality, bone strength and blood biochemistry in laying hens.

    PubMed

    Jiang, S; Cui, L Y; Hou, J F; Shi, C; Ke, X; Yang, L C; Ma, X P

    2014-01-01

    The objective of the study was to investigate the differences in eggshell quality, bone quality and serum bone biochemistry markers associated with changes in age and dietary soybean oil levels in laying hens. A total of 54, 19-week-old Hy-Line Brown laying hens were housed in 18 battery cages (3 birds/cage) and randomly divided into three diet treatments for 90 d: control-fat (CF, 1.9% soybean oil), moderate-fat (MF, 7% soybean oil) and high-fat (HF, 10% soybean oil). The hens' body weights (BW), egg production, egg weights, eggshell thickness and femoral diameter were higher at d 90 than at d 60 or d 30. Meanwhile, feed intake, relative bone weights, all bone strength parameters and serum Ca were lower at d 90 or 60 than at d 30. Compared to the CF hens, the feed intake, BW, abdominal fat pad weights and serum alkaline phosphatase activity were elevated in MF or HF hens. The eggshell thickness, relative femoral and tibial weight, femoral stiffness, femoral modulus, tibial mixed force and serum calcium and phosphorus levels were lower in MF or HF hens than CF hens. These findings suggest that bone loss in caged hens starts from an early stage of the laying period, and dietary oil (particularly with diets over 10% soybean oil) has harmful effects on eggshell quality, bone strength and bone mineralisation from an early stage of the laying period.

  7. Handgrip Strength: A Population-Based Study of Norms and Age Trajectories for 3- to 17-Year-Olds.

    PubMed

    Bohannon, Richard W; Wang, Ying-Chih; Bubela, Deborah; Gershon, Richard C

    2017-04-01

    To provide normative values and equations for grip strength obtained from a population-based sample of individuals 3 to 17 years of age. This cross-sectional study used grip strength data from 2706 participants (49.2% males, 91% right-hand dominant) in the normative phase of the National Institutes of Health Toolbox project. Analyses showed greater strength in the dominant hand in boys and with each yearly increase in age. Normative data are presented separately for each side, sex, and age. Separate regression equations using age and weight as explanatory variables of grip strength are provided for each side by sex. The normative data can serve as a guide for interpreting grip strength measurements. The trajectories can be used to investigate the effect of various pathologies and conditions on grip strength during physical maturation.

  8. Strength of initially virgin martensites at - 196 °C after aging and tempering

    NASA Astrophysics Data System (ADS)

    Eldis, George T.; Cohen, Morris

    1983-06-01

    The compressive strength at -196°C of martensites in Fe-0.26 pct C-24 pct Ni, Fe-0.4 pct C-21 pct Ni, and Fe-0.4 pct C-18 pct Ni-3 pct Mo alloys, all with subzero M temperatures, has been determined in the virgin condition and after one hour at temperatures from -80 to +400 °C. The effects of ausforming (20 pct reduction in area of the austenite by swaging at room temperature prior to the martensitic transformation) were also investigated. For the unausformed martensites, aging at temperatures up to 0 °C results in relatively small increases in strength. Above 0 °C, the age hardening increment increases rapidly, reaching a maximum at 100 °C. Above 100 °C, the strength decreases continuously with increasing tempering temperature except for the molybdenum-containing alloy, which exhibits secondary hardening on tempering at 400 °C. For the ausformed martensites, the response to aging at subzero temperatures is greater than for unausformed material. Strength again passes through a maximum on aging at 100 °C. However, on tempering just above 100 °C, the ausformed materials show a slower rate of softening than the unausformed martensites. The strengthening produced by the ausforming treatment is largest for the Fe-0.4 pct C-18 pct Ni-3 pct Mo alloy, but there is no evidence of carbide precipitation in the deformed austenite to a°Count for this effect of molybdenum.

  9. Executive Function in Very Preterm Children at Early School Age

    ERIC Educational Resources Information Center

    Aarnoudse-Moens, Cornelieke S. H.; Smidts, Diana P.; Oosterlaan, Jaap; Duivenvoorden, Hugo J.; Weisglas-Kuperus, Nynke

    2009-01-01

    We examined whether very preterm ([less than or equal to] 30 weeks gestation) children at early school age have impairments in executive function (EF) independent of IQ and processing speed, and whether demographic and neonatal risk factors were associated with EF impairments. A consecutive sample of 50 children (27 boys and 23 girls) born very…

  10. Executive Function in Very Preterm Children at Early School Age

    ERIC Educational Resources Information Center

    Aarnoudse-Moens, Cornelieke S. H.; Smidts, Diana P.; Oosterlaan, Jaap; Duivenvoorden, Hugo J.; Weisglas-Kuperus, Nynke

    2009-01-01

    We examined whether very preterm ([less than or equal to] 30 weeks gestation) children at early school age have impairments in executive function (EF) independent of IQ and processing speed, and whether demographic and neonatal risk factors were associated with EF impairments. A consecutive sample of 50 children (27 boys and 23 girls) born very…

  11. Titanium dioxide nanoparticles: Impact of increasing ionic strength during synthesis, reflux, and hydrothermal aging

    SciTech Connect

    Isley, Sara L.; Jordan, David S.; Penn, R. Lee

    2009-01-08

    This work investigates the role of ionic strength during synthesis, reflux, and hydrothermal aging of sol-gel synthesized titanium dioxide. Research presented here uses X-ray diffraction data and Rietveld refinements to quantify anatase, brookite, and rutile phases as functions of synthetic and aging variables. In addition, the Scherrer equation is used to obtain average crystallite sizes for each phase quantified. Results presented in this work demonstrate that the most control over the sol-gel products can be obtained by modifying the pH during hydrolysis. In addition, while varying the ionic strength during reflux and hydrothermal aging can result in enhanced control over the crystalline phase and crystallite size, the most control can be achieved by varying the ionic strength during synthesis. Finally, sol-gel synthesis at low pH (-0.6) and high-chloride concentration (3 M NaCl) produced a heterogeneous sample composed of nanocrystalline anatase (3.8 nm) and rutile (2.9 nm)

  12. The Association of Levels of and Decline in Grip Strength in Old Age with Trajectories of Life Course Occupational Position.

    PubMed

    Kröger, Hannes; Fritzell, Johan; Hoffmann, Rasmus

    2016-01-01

    The study of the influence of life course occupational position (OP) on health in old age demands analysis of time patterns in both OP and health. We study associations between life course time patterns of OP and decline in grip strength in old age. We analyze 5 waves from the Survey of Health Ageing and Retirement in Europe (n = 5108, ages 65-90). We use a pattern-mixture latent growth model to predict the level and decline in grip strength in old age by trajectory of life course OP. We extend and generalize the structured regression approach to establish the explanatory power of different life course models for both the level and decline of grip strength. Grip strength declined linearly by 0.70 kg (95% CI -0.74;-0.66) for men and 0.42 kg (95% CI -0.45;-0.39) for women per year. The level of men's grip strength can best be explained by a critical period during midlife, with those exposed to low OP during this period having 1.67 kg (95% CI -2.33;-1.00) less grip strength. These differences remain constant over age. For women, no association between OP and levels of or decline in grip strength was found. Men's OP in midlife seems to be a critical period for the level of grip strength in old age. Inequalities remain constant over age. The integration of the structured regression approach and latent growth modelling offers new possibilities for life course epidemiology.

  13. Laws of Influence of Structural Characteristics on the Strength and Crack Resistance of Aging Metallic Materials

    NASA Astrophysics Data System (ADS)

    Nizhnik, S. B.; Usikova, G. I.

    2005-01-01

    The structural characteristics (the volume fraction, size, and shape of and the distance among hardening-phase particles) of aging alloys and steels, which define the behavior of the critical stress intensity factor during thermal hardening, are determined using the structural-mechanical approach we have developed. It is experimentally demonstrated for maraging steels that our approach is capable of proving the correlations of strength, plasticity, and crack- resistance with the structural characteristics, which were varied by changing the chemical composition of steel and thermokinetic aging conditions

  14. Loudness perception affected by early age hearing loss.

    PubMed

    Sun, Wei; Fu, Qiang; Zhang, Chao; Manohar, Senthilvelan; Kumaraguru, Anand; Li, Ji

    2014-07-01

    Tinnitus and hyperacusis, commonly seen in adults, are also reported in children. Although clinical studies found children with tinnitus and hyperacusis often suffered from recurrent otitis media, there is no direct study on how temporary hearing loss in the early age affects the sound loudness perception. In this study, sound loudness changes in rats affected by perforation of the tympanic membranes (TM) have been studied using an operant conditioning based behavioral task. We detected significant increases of sound loudness and susceptibility to audiogenic seizures (AGS) in rats with bilateral TM damage at postnatal 16 days. As increase to sound sensitivity is commonly seen in hyperacusis and tinnitus patients, these results suggest that early age hearing loss is a high risk factor to induce tinnitus and hyperacusis in children. In the TM damaged rats, we also detected a reduced expression of GABA receptor δ and α6 subunits in the inferior colliculus (IC) compared to the controls. Treatment of vigabatrin (60 mg/kg/day, 7-14 days), an anti-seizure drug that inhibits the catabolism of GABA, not only blocked AGS, but also significantly attenuated the loudness response. Administration of vigabatrin following the early age TM damage could even prevent rats from developing AGS. These results suggest that TM damage at an early age may cause a permanent reduction of GABA tonic inhibition which is critical towards the maintenance of normal loudness processing of the IC. Increasing GABA concentration during the critical period may alleviate the impairment in the brain induced by early age hearing loss.

  15. Personal strengths and traumatic experiences among institutionalized children given up at birth (Les Enfants de Duplessis--Duplessis' children): I: Early experiences.

    PubMed

    Perry, J Christopher; Sigal, John J; Boucher, Sophie; Paré, Nikolas; Ouimet, Marie Claude

    2005-12-01

    We examined childhood and early adult strengths and adverse experiences of a group of orphans given up at or near birth and raised in Quebec institutions into early adulthood. A follow-up interview of 81 adults (41 women, 40 men) at a mean age of 59.2 years included retrospective assessments of childhood experiences. Most participants reported multiple early adverse experiences, including, in descending order, unfair rules and excessive punishment, physical abuse, emotional neglect, witnessing violence, verbal abuse, physical neglect, sexual abuse, and serious illness. Adverse experiences were mainly due to lay caretakers, not peers or nuns. Twelve childhood strengths, such as self-protectiveness and athletic talent, were scored at each of four age periods, yielding a median score equivalent to one strength at each period. Over half had significant childhood attachments, but of limited intimacy. Childhood variables correlated with their respective variables in later adulthood. Overall, these older adults reported a high prevalence of adverse or traumatic childhood experiences, counterbalanced by modest levels of individual strengths and attachment relationships. Institutionalization of children--if unavoidable--must build in effective safeguards against adverse experiences.

  16. Age-related maintenance of eccentric strength: a study of temperature dependence.

    PubMed

    Power, Geoffrey A; Flaaten, Nordan; Dalton, Brian H; Herzog, Walter

    2016-04-01

    With adult aging, eccentric strength is maintained better than isometric strength leading to a higher ratio of eccentric/isometric force production (ECC/ISO) in older than younger adults. The purpose was to investigate the ECC/ISO during electrical activation of the adductor pollicis during lengthening (20-320° s(-1)) contractions in 24 young (n = 12, ∼24 years) and old (n = 12, ∼72 years) males across muscle temperatures (cold ∼19 °C; normal ∼30 °C; warm ∼35 °C). For isometric force, the old were 20-30 % weaker in the normal and cold conditions (P < 0.05) with no difference for the warm condition compared to young (P > 0.05). Half-relaxation time (HRT) did not differ across age for the normal and warm temperatures (P > 0.05), but it slowed significantly for old in the cold condition compared with young (∼15 %; P < 0.05), as well, there was a 20 and 40 % increase in muscle stiffness for the young and old, respectively. ECC/ISO was 50-60 % greater for the cold condition than the normal and warm conditions. There was no age difference in ECC/ISO across ages for the normal and warm conditions (P > 0.05), but for the cold, the old exhibited a 20-35 % higher ECC/ISO than did the young for velocities above 60° s(-1) (P < 0.05). A contributing factor to the elevated ECC/ISO is an increased proportion of weakly compared to strongly bound crossbridges. These findings highlight the relationship (r = 0.70) between intrinsic muscle contractile speed (HRT) and eccentric strength in old age.

  17. The SAURON project - XXI. The spatially resolved UV-line strength relations of early-type galaxies

    NASA Astrophysics Data System (ADS)

    Jeong, Hyunjin; Yi, Sukyoung K.; Bureau, Martin; Davies, Roger L.; Bacon, Roland; Cappellari, Michele; de Zeeuw, P. Tim; Emsellem, Eric; Falcón-Barroso, Jesús; Krajnović, Davor; Kuntschner, Harald; McDermid, Richard M.; Peletier, Reynier F.; Sarzi, Marc; van den Bosch, Remco C. E.; van de Ven, Glenn

    2012-06-01

    The unexpected rising flux of early-type galaxies at decreasing ultraviolet (UV) wavelengths is a long-standing mystery. One important observational constraint is the correlation between UV-optical colours and Mg2 line strengths found by Burstein et al. The simplest interpretation of this phenomenon is that the UV strength is related to the Mg line strength. Under this assumption, we expect galaxies with larger Mg gradients to have larger UV colour gradients. By combining UV imaging from GALEX, optical imaging from MDM and SAURON integral-field spectroscopy, we investigate the spatially resolved relationships between UV colours and stellar population properties of 34 early-type galaxies from the SAURON survey sample. We find that galaxies with old stellar populations show tight correlations between the far-UV (FUV) colours (FUV -V and FUV - NUV) and the Mg b index, Hβ index and metallicity [Z/H]. The equivalent correlations for the Fe5015 index, α-enhancement [α/Fe] and age are present but weaker. We have also derived logarithmic internal radial colour, measured line strength and derived stellar population gradients for each galaxy and again found a strong dependence of the FUV -V and FUV - NUV colour gradients on both the Mg b line strength and the metallicity gradients for galaxies with old stellar populations. In particular, global gradients of Mg b and [Z/H] with respect to the UV colour [e.g. Δ(Mg b)/Δ(FUV - NUV) and Δ[Z/H]/Δ(FUV - NUV)] across galaxies are consistent with their local gradients within galaxies, suggesting that the global correlations also hold locally. From a simple model based on multiband colour fits of UV upturn and UV-weak galaxies, we have identified a plausible range of parameters that reproduces the observed radial colour profiles. In these models, the centres of elliptical galaxies, where the UV flux is strong, are enhanced in metals by roughly 60 per cent compared to UV-weak regions.

  18. Age at menarche is associated with divergent alcohol use patterns in early adolescence and early adulthood.

    PubMed

    Richards, Meghan A; Oinonen, Kirsten A

    2011-10-01

    A cross-sectional retrospective design was employed to examine the relationship between age at menarche (AAM) and alcohol use patterns from middle childhood (age 7) to early adulthood in 265 University-aged women. Earlier menarche was associated with: (a) earlier ages at first drink and first intoxication, (b) greater use between ages 9 and 14 (i.e., frequency, amount, vomiting), and (c) binge drinking between ages 11 and 14. In contrast, late menarche was associated with greater current use in the adult women (i.e., frequency, amount, hangovers). Early timing of first intoxication relative to menarche (FIRM) strongly predicted higher current drinking. These findings suggest: (a) a link between AAM and alcohol use as early as age 9, (b) opposite relationships between AAM and alcohol use during two distinct developmental periods separated by a period of use unassociated with AAM, and (c) that the impact of early FIRM on adult consumption deserves further study. Copyright © 2010 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  19. Supporting Early Childhood Preservice Teachers in Their Work with Children and Families with Complex Needs: A Strengths Approach

    ERIC Educational Resources Information Center

    Fenton, Angela; McFarland-Piazza, Laura

    2014-01-01

    This article explores the potential of tailoring the inherent principles of the Strengths Approach (McCashen, 2005) for preparing early childhood educators to work with children and families with complex needs. The term "Strengths Approach" (capitalized) is presented in the article as the name of a specific approach developed by St.…

  20. Supporting Early Childhood Preservice Teachers in Their Work with Children and Families with Complex Needs: A Strengths Approach

    ERIC Educational Resources Information Center

    Fenton, Angela; McFarland-Piazza, Laura

    2014-01-01

    This article explores the potential of tailoring the inherent principles of the Strengths Approach (McCashen, 2005) for preparing early childhood educators to work with children and families with complex needs. The term "Strengths Approach" (capitalized) is presented in the article as the name of a specific approach developed by St.…

  1. Lifelong strength training mitigates the age-related decline in efferent drive.

    PubMed

    Unhjem, Runar; Nygård, Mona; van den Hoven, Lene T; Sidhu, Simranjit K; Hoff, Jan; Wang, Eivind

    Recently, we documented age-related attenuation of efferent drive to contracting skeletal muscle. It remains elusive if this indication of reduced muscle strength is present with lifelong strength training. For this purpose, we examined evoked potentials in the calf muscles of 11 [71 ± 4 (SD) yr] strength-trained master athletes (MA) contrasted with 10 (71 ± 4 yr) sedentary (SO) and 11 (73 ± 6 yr) recreationally active (AO) old subjects, as well as 9 (22 ± 2 yr) young controls. As expected, MA had higher leg press maximal strength (MA, 185 ± 32 kg; AO, 128 ± 15 kg; SO, 106 ± 11 kg; young, 147 ± 22 kg, P < 0.01) and rate of force development (MA, 5,588 ± 2,488 N/s; AO, 2,156 ± 1,100 N/s; SO, 2,011 ± 825 N/s; young, 3,663 ± 1,140 N/s, P < 0.05) than the other groups. MA also exhibited higher musculus soleus normalized V waves during maximal voluntary contractions (MVC) [maximal V wave amplitude/maximal M wave during MVC (Vsup/Msup); 0.28 ± 0.15] than AO (0.13 ± 0.06, P < 0.01) and SO (0.11 ± 0.05, P < 0.01), yet lower than young (0.45 ± 0.12, P < 0.01). No differences were apparent between the old groups in H reflex recorded at rest or during MVC [maximal H reflex amplitude/maximal M wave during rest (Hmax/Mmax); maximal H reflex amplitude during MVC/maximal M wave during MVC (Hsup/Msup)], and all were lower (P < 0.01) than young. MA (34.4 ± 2.1 ms) had shorter (P < 0.05) H reflex latency compared with AO (36.4 ± 3.7 ms) and SO (37.3 ± 3.2 ms), but longer (P < 0.01) than young (30.7 ± 2.0 ms). Using interpolated twitch analysis, MA (89 ± 7%) had plantar flexion voluntary activation similar to young (90 ± 6%), and this was higher (P < 0.05), or tended to be higher (P = 0.06-0.09), than SO (83 ± 10%) and AO (84 ± 5%). These observations suggest that lifelong strength training has a protective effect against age-related attenuation of efferent drive. In contrast, no beneficial effect seems to derive from habitual recreational activity, indicating

  2. Effect of aging conditions on the repair bond strength of a microhybrid and a nanohybrid resin composite.

    PubMed

    Ozcan, Mutlu; Cura, Cenk; Brendeke, Johannes

    2010-12-01

    this study evaluated the effect of different aging methods on the repair bond strength and failure types of a microhybrid and a nanohybrid composite. disk-shaped microhybrid (Quadrant Anterior Shine-QA) and nanohybrid (Tetric EvoCeram-TE) resin composite specimens (N = 192, n = 12/per group) were photopolymerized and randomly assigned to one of the three aging conditions: (1) immersion in deionized water (37°C, 2 months), (2) thermocycling (5000 times, 5 to 55 °C), (3) immersion in citric acid (pH: 3.0; 1 week). The control group was stored dry for 24 h at 37°C. After aging procedures, the specimens were silica coated (30 microm SiO2) (CoJet-Sand) using an intraoral air abrasion device, silanized (ESPESil) and an intermediate adhesive resin was applied (Visio-Bond, 3M ESPE). Resin composites, once of the same kind as the substrate (QA-QA, TE-TE) and once other than the substrate material (QA-TE, TE-QA) were adhered onto the conditioned substrates. Shear force was applied to the adhesive interface in a universal testing machine (cross-head speed: 1 mm/min). a significant influence of the aging method was observed (p < 0.05) but the composite type did not affect the repair bond strength (p = 0.755) (2-way ANOVA, Tukey's test). Interaction terms were significant (p < 0.05). Thermocycling showed lower results (10 ± 2.6 to 14.4 ± 4.4 MPa) than those of other aging methods (12.7 ± 5.2 to 28 ± 5.3 MPa). Using the substrate and the adherend interchangeably (QA-TE, TE-QA) did not show significant differences in the control group, but the results were significant after aging (p = 0.007) (2-way ANOVA, Tukey's test). Interaction terms were not significant (p = 0.124). The incidence of score A (cohesive failures in the substrate) was not significant between the composite combinations in the control groups (exclusively 100%) and water-storage aged groups (92% to 100%) (p > 0.05) (chi-square). Citric acid aging yielded significantly less incidence of score A (8

  3. Muscular strength and bone density with weight training in middle-aged women.

    PubMed

    Peterson, S E; Peterson, M D; Raymond, G; Gilligan, C; Checovich, M M; Smith, E L

    1991-04-01

    Previous research has demonstrated positive correlations between bone mass and both physical activity and muscular strength. There is a paucity of information describing the specific type of exercise which most benefits the human skeleton. The effects of a 1 yr weight training program on 18 middle-aged women participating in an endurance dance program (E + W) compared with 17 other women in the endurance dance program only (E) and with 19 sedentary controls (C) were studied by measuring muscular strength and bone mineral density (BMD). Eighteen women in the E + W group demonstrated increases in all strength measurements, whereas the E and C groups either had smaller increases or had declined. A significant group x test interaction term, indicating that groups responded differently over time, was observed for nondominant isokinetic elbow flexion measured through the range of motion at a constant velocity of 60 degrees.s-1 (P less than 0.05), nondominant isokinetic elbow extension at 180 degrees.s-1 (P less than 0.01), and nondominant isokinetic elbow flexion at 180 degrees.s-1 (P less than 0.05). BMD did not change significantly except that a significant group x test interaction term appeared for the radius ultradistal site (P less than 0.01). BMD of the humerus and femoral Ward's triangle increased nonsignificantly in both E and E + W over the year. This weight training program increased muscular strength but did not increase measured bone mass.

  4. Age, sex and personality in early cannabis use.

    PubMed

    Muro I Rodríguez, A

    2015-06-01

    Previous studies analysing personality and cannabis use in adult samples suggest that cannabis users show significant higher levels of impulsivity, sensation seeking and schizotypy. However, there are few studies exploring this relationship in adolescence using psychobiological models of personality. Given the relevance of identifying individual differences that lead adolescents to early cannabis use to prevent future health problems, the present study aimed to explore the relationship between age, sex, personality and early cannabis use using a psychobiological model of personality in a sample of 415 students (51.8% boys) from 12 to 18 years. Chi(2) tests showed significant higher prevalence of cannabis use in boys and in the group aged 15-18 years. Multiple analysis of variance showed significant higher scores in psychoticism, sensation seeking and in all its subscales in cannabis users group, while an interaction with age was found for extraversion and neuroticism: cannabis users scored higher than non-users in the youngest group (12-14 years) but lower in the oldest group in both dimensions. Finally, regression analysis showed that narrower traits of sensation seeking (experience seeking and disinhibition) were the most associated to early cannabis use. Results are discussed in terms of early cannabis users' personality profiles and in terms of the self-medication theory.

  5. Loss of Nfkb1 leads to early onset aging.

    PubMed

    Bernal, Giovanna M; Wahlstrom, Joshua S; Crawley, Clayton D; Cahill, Kirk E; Pytel, Peter; Liang, Hua; Kang, Shijun; Weichselbaum, Ralph R; Yamini, Bakhtiar

    2014-11-01

    NF-κB is a major regulator of age-dependent gene expression and the p50/NF-κB1 subunit is an integral modulator of NF-κB signaling. Here, we examined Nfkb1-/- mice to investigate the relationship between this subunit and aging. Although Nfkb1-/- mice appear similar to littermates at six months of age, by 12 months they have a higher incidence of several observable age-related phenotypes. In addition, aged Nfkb1-/- animals have increased kyphosis, decreased cortical bone, increased brain GFAP staining and a decrease in overall lifespan compared to Nfkb1+/+. In vitro, serially passaged primary Nfkb1-/- MEFs have more senescent cells than comparable Nfkb1+/+ MEFs. Also, Nfkb1-/- MEFs have greater amounts of phospho-H2AX foci and lower levels of spontaneous apoptosis than Nfkb1+/+, findings that are mirrored in the brains of Nfkb1-/- animals compared to Nfkb1+/+. Finally, in wildtype animals a substantial decrease in p50 DNA binding is seen in aged tissue compared to young. Together, these data show that loss of Nfkb1 leads to early animal aging that is associated with reduced apoptosis and increased cellular senescence. Moreover, loss of p50 DNA binding is a prominent feature of aged mice relative to young. These findings support the strong link between the NF-κB pathway and mammalian aging.

  6. Early Postoperative Measures Predict 1- and 2-Year Outcomes After Unilateral Total Knee Arthroplasty: Importance of Contralateral Limb Strength

    PubMed Central

    Snyder-Mackler, Lynn

    2010-01-01

    Background Total knee arthroplasty (TKA) has been shown to be an effective surgical intervention for people with end-stage knee osteoarthritis. However, recovery of function is variable, and not all people have successful outcomes. Objective The aim of this study was to discern which early postoperative functional measures could predict functional ability at 1 year and 2 years after surgery. Design and Methods One hundred fifty-five people who underwent unilateral TKA participated in the prospective longitudinal study. Functional evaluations were performed at the initial outpatient physical therapy appointment and at 1 and 2 years after surgery. Evaluations consisted of measurements of height, weight, quadriceps muscle strength (force-generating capacity), and knee range of motion; the Timed “Up & Go” Test (TUG); the stair-climbing task (SCT); and the Knee Outcome Survey (KOS) questionnaire. The ability to predict 1- and 2-year outcomes on the basis of early postoperative measures was analyzed with a hierarchical regression. Differences in functional scores were evaluated with a repeated-measures analysis of variance. Results The TUG, SCT, and KOS scores at 1 and 2 years showed significant improvements over the scores at the initial evaluation (P<.001). A weaker quadriceps muscle in the limb that did not undergo surgery (“nonoperated limb”) was related to poorer 1- and 2-year outcomes even after the influence of the other early postoperative measures was accounted for in the regression. Older participants with higher body masses also had poorer outcomes at 1 and 2 years. Postoperative measures were better predictors of TUG and SCT times than of KOS scores. Conclusions Rehabilitation regimens after TKA should include exercises to improve the strength of the nonoperated limb as well as to treat the deficits imposed by the surgery. Emphasis on treating age-related impairments and reducing body mass also might improve long-term outcomes. PMID:19959653

  7. Dexterous Manipulation Is Poorer at Older Ages and Is Dissociated From Decline of Hand Strength

    PubMed Central

    Dayanidhi, Sudarshan

    2014-01-01

    Background. The ability to dynamically control fingertip force vector magnitude and direction is critical for dexterous manipulation. We quantified the dynamic control of fingertip forces to examine how dexterous manipulation declines with age. Methods. The strength–dexterity (SD) test measures fingertip forces during compression of a slender spring prone to instability and buckling. The greatest sustained compression (designed to be under 3 N), and force dynamics therein, have been shown to be simple and quick measures of dynamic dexterous manipulation ability. We measured pinch strength and strength–dexterity test in a cross-sectional population of 98 people from 18 to 89 years of age. Results. Dexterous manipulation ability is poorer at older ages, beginning in middle age (p < .001), with greater decline past 65 years of age. Fingertip force dynamics during spring compression and stabilization show a deterioration of neuromuscular control with age. Importantly, this novel detection of decline in dynamic manipulation ability is not correlated with, and thus cannot be entirely explained by, the known decline in pinch strength. We also measured standardized tests of dexterity in participants older than 45, and discuss how the strength–dexterity test uniquely captures features of sensorimotor capabilities for dexterous manipulation in this adult population. Conclusions. Starting in middle age, changes in the functional interactions among sensory, motor, and neural capabilities result in measurably poorer dynamic dexterous manipulation. This deterioration of neuromuscular control motivates and enables future studies to understand the physiological bases for this functional decline so critical to activities of daily living and quality of life. PMID:24610868

  8. Effects of negative ageing on deformation and strength response of geomaterials

    NASA Astrophysics Data System (ADS)

    Aziz, M.; Towhata, I.; Yamada, S.; Qureshi, M. U.; Kawano, K.

    2009-04-01

    Negative ageing or decay of grains with time is often ignored in conventional geotechnical investigations. Geology is always vital in such a scenario but the micro-scale geotechnical point of concern is the time-dependent loss of strength and deformation characteristics. This paper presents unique data from torsional shear tests on crushed soft rocks from Yokosuka, Japan and 2005-Kashmir earthquake hit areas of Pakistan. Material being sensitive to disintegrate by water-action allowed to simulate the long-term stress-strain and volume change response under saturated conditions whereas dry tests on similar soil represent initial intact response of the material. Negative ageing is manipulated by an enormous decrease in shear strength parameters, changes in grain size curve and increase in volumetric compression. It is concluded that for long-term hazard evaluation of various geotechnical structures, the effects of loss of strength due to decay of grains with time should be incorporated in conventional analysis and design models.

  9. Iron supplementation of breastfed infants from an early age.

    PubMed

    Ziegler, Ekhard E; Nelson, Steven E; Jeter, Janice M

    2009-02-01

    In breastfed infants, iron deficiency at <6 mo of life, although uncommon, is observed in industrialized countries. Iron supplementation starting at an early age may prevent iron deficiency. The study assessed the effect of early iron supplementation of breastfed infants and tested the hypothesis that iron supplementation enhances iron status. Potential adverse effects (tolerance and growth) were monitored. The prospective, placebo-controlled study involved exclusively breastfed infants who were randomly assigned at 1 mo of age to iron (n = 37) or placebo (n = 38). Iron (7 mg/d as multivitamin preparation with ferrous sulfate) or placebo (multivitamin preparation without iron) was given from 1 to 5.5 mo of age. Complementary foods were allowed at >4 mo. Infants were followed to 18 mo. Blood concentrations of ferritin, transferrin receptor, hemoglobin, and red cell indexes were determined at bimonthly intervals. Stool consistency and color and feeding behavior were recorded. Iron supplementation caused modest augmentation of iron status during the intervention at 4 and 5.5 mo but not thereafter. Iron supplements were well tolerated and had no measurable effect on growth. One infant developed iron deficiency anemia by 5.5 mo of age. Plasma ferritin and hemoglobin tracked over time. Early iron supplementation of breastfed infants is feasible and transiently increases iron status but not hematologic status. Iron is tolerated by most infants. The prevalence of iron deficiency anemia is low (3%) among unsupplemented breastfed infants in the first 6 mo of life.

  10. Where is ELSA? The early to late shift in aging.

    PubMed

    Dew, Ilana T Z; Buchler, Norbou; Dobbins, Ian G; Cabeza, Roberto

    2012-11-01

    Studies of cognitive and neural aging have recently provided evidence of a shift from an early- to late-onset cognitive control strategy, linked with temporally extended activity in the prefrontal cortex (PFC). It has been uncertain, however, whether this age-related shift is unique to PFC and executive control tasks or whether the functional location might vary depending on the particular cognitive processes that are altered. The present study tested whether an early-to-late shift in aging (ELSA) might emerge in the medial temporal lobes (MTL) during a protracted context memory task comprising both anticipatory cue (retrieval preparation) and retrieval probe (retrieval completion) phases. First, we found reduced MTL activity in older adults during the early retrieval preparation phase coupled with increased MTL activity during the late retrieval completion phase. Second, we found that functional connectivity between MTL and PFC regions was higher during retrieval preparation in young adults but higher during retrieval completion in older adults, suggesting an important interactive relationship between the ELSA pattern in MTL and PFC. Taken together, these results critically suggest that aging results in temporally lagged activity even in regions not typically associated with cognitive control, such as the MTL.

  11. Iron supplementation of breastfed infants from an early age123

    PubMed Central

    Ziegler, Ekhard E; Nelson, Steven E; Jeter, Janice M

    2009-01-01

    Background: In breastfed infants, iron deficiency at <6 mo of life, although uncommon, is observed in industrialized countries. Iron supplementation starting at an early age may prevent iron deficiency. Objective: The study assessed the effect of early iron supplementation of breastfed infants and tested the hypothesis that iron supplementation enhances iron status. Potential adverse effects (tolerance and growth) were monitored. Design: The prospective, placebo-controlled study involved exclusively breastfed infants who were randomly assigned at 1 mo of age to iron (n = 37) or placebo (n = 38). Iron (7 mg/d as multivitamin preparation with ferrous sulfate) or placebo (multivitamin preparation without iron) was given from 1 to 5.5 mo of age. Complementary foods were allowed at >4 mo. Infants were followed to 18 mo. Blood concentrations of ferritin, transferrin receptor, hemoglobin, and red cell indexes were determined at bimonthly intervals. Stool consistency and color and feeding behavior were recorded. Results: Iron supplementation caused modest augmentation of iron status during the intervention at 4 and 5.5 mo but not thereafter. Iron supplements were well tolerated and had no measurable effect on growth. One infant developed iron deficiency anemia by 5.5 mo of age. Plasma ferritin and hemoglobin tracked over time. Conclusion: Early iron supplementation of breastfed infants is feasible and transiently increases iron status but not hematologic status. Iron is tolerated by most infants. The prevalence of iron deficiency anemia is low (3%) among unsupplemented breastfed infants in the first 6 mo of life. PMID:19073791

  12. Sex and Age Effects of Functional Connectivity in Early Adulthood.

    PubMed

    Zhang, Chao; Cahill, Nathan D; Arbabshirani, Mohammad R; White, Tonya; Baum, Stefi A; Michael, Andrew M

    2016-11-01

    Functional connectivity (FC) in resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to find coactivating regions in the human brain. Despite its widespread use, the effects of sex and age on resting FC are not well characterized, especially during early adulthood. Here we apply regression and graph theoretical analyses to explore the effects of sex and age on FC between the 116 AAL atlas parcellations (a total of 6670 FC measures). rs-fMRI data of 494 healthy subjects (203 males and 291 females; age range: 22-36 years) from the Human Connectome Project were analyzed. We report the following findings. (1) Males exhibited greater FC than females in 1352 FC measures (1025 survived Bonferroni correction; [Formula: see text]). In 641 FC measures, females exhibited greater FC than males but none survived Bonferroni correction. Significant FC differences were mainly present in frontal, parietal, and temporal lobes. Although the average FC values for males and females were significantly different, FC values of males and females exhibited large overlap. (2) Age effects were present only in 29 FC measures and all significant age effects showed higher FC in younger subjects. Age and sex differences of FC remained significant after controlling for cognitive measures. (3) Although sex [Formula: see text] age interaction did not survive multiple comparison correction, FC in females exhibited a faster cross-sectional decline with age. (4) Male brains were more locally clustered in all lobes but the cerebellum; female brains had a higher clustering coefficient at the whole-brain level. Our results indicate that although both male and female brains show small-world network characteristics, male brains were more segregated and female brains were more integrated. Findings of this study further our understanding of FC in early adulthood and provide evidence to support that age and sex should be controlled for in FC studies of young adults.

  13. Age- and sex-related regional compressive strength characteristics of human lumbar vertebrae in osteoporosis

    PubMed Central

    Kurutz, Márta; Donáth, Judit; Gálos, Miklós; Varga, Péter; Fornet, Béla

    2008-01-01

    Objective To obtain the compressive load bearing and energy absorption capacity of lumbar vertebrae of osteoporotic elderly for the everyday medical praxis in terms of the simple diagnostic data, like computed tomography (CT), densitometry, age, and sex. Methods Compressive test of 54 osteoporotic cadaver vertebrae L1 and L2, 16 males and 38 females (age range 43–93, mean age 71.6 ± 13.3 years, mean bone mineral density (BMD) 0.377 ± 0.089 g/cm2, mean T-score −5.57 ± 0.79, Z-score −4.05 ± 0.77) was investigated. Based on the load-displacement diagrams and the measured geometrical parameters of vertebral bodies, proportional, ultimate and yield stresses and strains, Young’s modulus, ductility and energy absorption capacity were determined. Three vertebral regions were distinguished: superior, central and inferior regions, but certain parameters were calculated for the upper/ lower intermediate layers, as well. Cross-sectional areas, and certain bone tissue parameters were determined by image analysis of CT pictures of vertebrae. Sex- and age-related decline functions and trends of strength characteristics were determined. Results Size-corrected failure load was 15%–25% smaller in women, proportional and ultimate stresses were about 30%–35% smaller for women in any region, and 20%–25% higher in central regions for both sexes. Young’s moduli were about 30% smaller in women in any region, and 20%–25% smaller in the central region for both sexes. Small strains were higher in males, large strains were higher in females, namely, proportional strains were about 25% larger in men, yield and ultimate strains were quasi equal for sexes, break strains were 10% higher in women. Ultimate energy absorption capacity was 10%–20% higher in men; the final ductile energy absorption capacity was quasi equal for sexes in all levels. Age-dependence was stronger for men, mainly in central regions (ultimate load, male: r = −0.66, p < 0.01, female: r = −0.52, p

  14. Cognitive impairment in school-aged children with early trauma.

    PubMed

    Bücker, Joana; Kapczinski, Flavio; Post, Robert; Ceresér, Keila M; Szobot, Claudia; Yatham, Lakshmi N; Kapczinski, Natalia S; Kauer-Sant'Anna, Márcia

    2012-08-01

    Exposure to traumatic events during childhood is often associated with the development of psychiatric disorders, cognitive impairment, and poor functioning in adulthood. However, few studies have examined cognitive function, including executive function, memory, and attention, in school-aged children with early trauma compared with age- and sex-matched controls. We recruited 30 medication-naive children between 5 and 12 years of age with a history of early severe trauma from a foster care home, along with 30 age- and sex-matched controls. Psychiatric diagnoses were based on Kiddie Schedule for Affective Disorders and Schizophrenia Epidemiologic Version (K-SADS-E) for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and were confirmed with a clinical interview. The neuropsychologic battery was tailored to assess broad cognitive domains such as learning/working memory, executive function, attention, verbal/premorbid intellectual functioning, and impulsivity. There was a higher prevalence of subsyndromal symptoms in children with a history of childhood trauma, although they rarely met all of the diagnostic criteria for a disorder. Moreover, lower estimated intellectual functioning scores were associated with subsyndromal symptoms in children with a history of trauma, and they performed more poorly on the Digits Span Test of the Wechsler Intelligence Scale for Children-III Edition, suggesting attention impairment. There is a high prevalence of subsyndromal symptoms in school-aged children with trauma and an attention impairment, which may contribute to a cumulative deficit early in cognitive development. These findings further support the need for early interventions that can prevent cognitive impairment when childhood trauma occurs. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Suicide in Elementary School-Aged Children and Early Adolescents

    PubMed Central

    Sheftall, Arielle H.; Asti, Lindsey; Horowitz, Lisa M.; Felts, Adrienne; Fontanella, Cynthia A.; Campo, John V.

    2016-01-01

    BACKGROUND AND OBJECTIVES: Suicide in elementary school–aged children is not well studied, despite a recent increase in the suicide rate among US black children. The objectives of this study were to describe characteristics and precipitating circumstances of suicide in elementary school–aged children relative to early adolescent decedents and identify potential within-group racial differences. METHODS: We analyzed National Violent Death Reporting System (NVDRS) surveillance data capturing suicide deaths from 2003 to 2012 for 17 US states. Participants included all suicide decedents aged 5 to 14 years (N = 693). Age group comparisons (5–11 years and 12–14 years) were conducted by using the χ2 test or Fisher’s exact test, as appropriate. RESULTS: Compared with early adolescents who died by suicide, children who died by suicide were more commonly male, black, died by hanging/strangulation/suffocation, and died at home. Children who died by suicide more often experienced relationship problems with family members/friends (60.3% vs 46.0%; P = .02) and less often experienced boyfriend/girlfriend problems (0% vs 16.0%; P < .001) or left a suicide note (7.7% vs 30.2%; P < .001). Among suicide decedents with known mental health problems (n = 210), childhood decedents more often experienced attention-deficit disorder with or without hyperactivity (59.3% vs 29.0%; P = .002) and less often experienced depression/dysthymia (33.3% vs 65.6%; P = .001) compared with early adolescent decedents. CONCLUSIONS: These findings raise questions about impulsive responding to psychosocial adversity in younger suicide decedents, and they suggest a need for both common and developmentally-specific suicide prevention strategies during the elementary school–aged and early adolescent years. Further research should investigate factors associated with the recent increase in suicide rates among black children. PMID:27647716

  16. Suicide in Elementary School-Aged Children and Early Adolescents.

    PubMed

    Sheftall, Arielle H; Asti, Lindsey; Horowitz, Lisa M; Felts, Adrienne; Fontanella, Cynthia A; Campo, John V; Bridge, Jeffrey A

    2016-10-01

    Suicide in elementary school-aged children is not well studied, despite a recent increase in the suicide rate among US black children. The objectives of this study were to describe characteristics and precipitating circumstances of suicide in elementary school-aged children relative to early adolescent decedents and identify potential within-group racial differences. We analyzed National Violent Death Reporting System (NVDRS) surveillance data capturing suicide deaths from 2003 to 2012 for 17 US states. Participants included all suicide decedents aged 5 to 14 years (N = 693). Age group comparisons (5-11 years and 12-14 years) were conducted by using the χ(2) test or Fisher's exact test, as appropriate. Compared with early adolescents who died by suicide, children who died by suicide were more commonly male, black, died by hanging/strangulation/suffocation, and died at home. Children who died by suicide more often experienced relationship problems with family members/friends (60.3% vs 46.0%; P = .02) and less often experienced boyfriend/girlfriend problems (0% vs 16.0%; P < .001) or left a suicide note (7.7% vs 30.2%; P < .001). Among suicide decedents with known mental health problems (n = 210), childhood decedents more often experienced attention-deficit disorder with or without hyperactivity (59.3% vs 29.0%; P = .002) and less often experienced depression/dysthymia (33.3% vs 65.6%; P = .001) compared with early adolescent decedents. These findings raise questions about impulsive responding to psychosocial adversity in younger suicide decedents, and they suggest a need for both common and developmentally-specific suicide prevention strategies during the elementary school-aged and early adolescent years. Further research should investigate factors associated with the recent increase in suicide rates among black children. Copyright © 2016 by the American Academy of Pediatrics.

  17. Early Evidence of the Italian Parent-Report Strengths and Difficulties Questionnaire (SDQ-P).

    PubMed

    Li, Jian-Bin; Delvecchio, Elisa; Di Riso, Daniela; Lis, Adriana; Salcuni, Silvia

    2017-04-01

    The parent-report Strengths and Difficulties Questionnaire (SDQ-P) is a widely used scale that assesses children's and adolescents' strengths and difficulties. The present study applied this scale to Italian adolescents and compared the current results with previous Chinese findings and the United Kingdom norm. Participants were 422 Italian parents and their adolescent children. Parents and adolescents answered the parent-report and the self-report SDQ, respectively. Results showed that the five-factor first-order model was better than other competing models. Cronbach's alpha of emotional problems, conduct problems, hyperactivity, peer problems, prosocial behavior, and total difficulties was .63, .52, .69, .51, .59, and .77 respectively for mother-report measure, and .67, .48, .67, .46, .55, and .79 respectively for father-report measure. Parent-adolescent agreements ranged from low to medium, whereas mother-father agreements were large. Parents did not rate boys and girls as well as early-adolescence and mid-adolescence differently. Italian parents rated their adolescent children to have lower levels of hyperactivity, peer problems, total difficulties, and higher levels of prosocial behavior than Chinese parents; and Italian mothers rated their adolescent children to have lower levels of hyperactivity than United Kingdom parents. In conclusion, the current findings suggest both strengths and inadequacies of the SDQ-P for Italian adolescents.

  18. Effect of initial curing on early strength and physical properties of a lightweight concrete

    SciTech Connect

    Al-Khaiat, H.; Haque, M.N.

    1998-06-01

    A 50 MPa 28-day cube compressive strength structural lightweight concrete of a fresh concrete density of 1800 kg/m{sup 3} was produced using Lytag coarse and fine aggregate. The long-term strength development and the durability characteristics of this lightweight concrete are being monitored in both the severe hot and dry and hot-coastal and salt-laden exposure conditions prevalent in Kuwait. The early results of the investigation suggest that the compressive strength of this concrete is less sensitive to lack of initial curing. However, depth of water penetration, which is indicative of the concrete`s permeability and hence durability, has been found to be more sensitive to the duration of initial curing even for the specimens exposed to the high-humidity seaside ambient conditions. The drying shrinkage of this concrete has been found to be more than 600 microstrain in the first 3 months` duration. Longer term durability data will be reported in due course.

  19. Population-based reference values of handgrip strength and functional tests of muscle strength and balance in men aged 70-80 years.

    PubMed

    Ribom, Eva L; Mellström, Dan; Ljunggren, Östen; Karlsson, Magnus K

    2011-01-01

    With aging, the incidence of falls and fractures increases. There has during the last decades been secular changes in demographics so that the proportion of elderly increases in society. Hence, there is an increasing need for clinicians to be able to make a solid appraisal of the elderly patient's functional capacity, as to identify individuals with an increased risk to fall. If high risk individuals could be targeted fall preventive strategies might be implemented in specific risk cohorts. This would require reference values for muscle strength tests and functional tests, in order to defined high risk individuals performing inferior. From the MrOS Sweden cohort, 999 subjects aged 70-80 years were evaluated. Muscle strength and functional performance was tested by timed-stands test, 6-m and 20-cm narrow walk tests and Jamar handgrip strength test. Normative data is presented. With increasing age, there was a 10-18% successively decline in performance throughout the entire age span. This study provides reference values for handgrip strength and functional muscle tests in 70-80 years old men. The decline in the test values with increasing age, infer the use of age-specific normative data when using these tests both in clinical and research settings. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Grip strength reference values for Canadians aged 6 to 79: Canadian Health Measures Survey, 2007 to 2013.

    PubMed

    Wong, Suzy L

    2016-10-19

    Grip strength is a measure of overall muscular strength and has been associated with disability, morbidity and mortality. Normative data are used to interpret an individual's grip strength measurements, but Canadian reference values are not available for a wide age range. The data pertain to 11,108 respondents aged 6 to 79 to the 2007-to-2013 Canadian Health Measures Survey, whose right-hand and left-hand grip strength were measured with a handgrip dynamometer. Quantile regression was used to develop reference equations for males and females for maximum, right-hand and left-hand grip strength for selected percentiles as a function of age, height and weight. Reference values for grip strength increased through childhood and adolescence, peaked around age 40, and then declined. Reference values were higher for males than for females; differences between the sexes were smaller during childhood than in adolescence and adulthood. Differences between reference values for maximum, right-hand and left-hand grip strength varied by age and sex. Based on a large, healthy, nationally representative sample, reference equations were developed for grip strength of Canadians from childhood to older adulthood. These equations can be used to determine the reference values that correspond to an individual of a given age, sex, height and weight.

  1. A possible dependence of tectonic strength on the age of the crust in Asia

    NASA Technical Reports Server (NTRS)

    Molnar, P.; Tapponnier, P.

    1981-01-01

    In Asia, the intensity and style of active tectonics appears to depend on the age of the last orogenic activity. The shields have remained essentially undeformed during the India-Eurasian collision, but Paleozoic and Mesozoic orogenic belts apparently have been reactivated by this collision, with a suggestion of greater reactivation and more diffuse deformation of the younger belts. If the greater observed heat flow in regions of more recent orogenic activity reflects, at least in part, a greater heat flow from the mantle beneath the younger belts, then the temperatures in the mantle beneath the younger belts should be higher than beneath older belts and shields. Because of the strong dependence on temperature of the creep strength of minerals, particularly of olivine, the crust and mantle beneath the hotter, younger belts should be much weaker than those beneath older belts. This difference in temperature, and consequent difference in strength, may be the cause of the greater reactivation of younger belts.

  2. Adaptations to long-term strength training of ankle joint muscles in old age.

    PubMed

    Simoneau, Emilie; Martin, Alain; Van Hoecke, Jacques

    2007-07-01

    The aim of this study was to enquire whether older adults, who continue plantar-flexion (PF) strength training for an additional 6-month period, would achieve further improvements in neuromuscular performance, in the ankle PFs, and in the antagonist dorsi-flexors (DFs). Twenty-three healthy older volunteers (mean age 77.4 +/- 3.7 years) took part in this investigation and 12 of them followed a 1-year strength-training program. Both neural and muscular factors were examined during isometric maximal voluntary contraction (MVC) torques in ankle PF and DF pre-training, post 6 and post 12 months. The main finding was that 6 months of additional strength training of the PFs, beyond 6 months, allowed further improvements in neuromuscular performance at the ankle joint in older adults. Indeed, during the first 6 months of progressive resistance training, there was an increase in the PF MVC torque of 11.1 +/- 19.9 N m, and then of 11.1 +/- 17.9 N m in the last 6-month period. However, it was only after 1 year that there was an improvement in the evoked contraction at rest in PF (+ 8%). The strength training of the agonist PF muscles appeared to have an impact on the maximal resultant torque in DF. However, it appeared that this gain was first due to modifications occurring in the trained PFs muscles, then, it seemed that the motor drive of the DFs per se was altered. In conclusion, long-term strength training of the PFs resulted in continued improvements in neuromuscular performance at the ankle joint in older adults, beyond the initial 6 months.

  3. Effect of aging on tear strength and cytotoxicity of soft denture lining materials; in vitro.

    PubMed

    Landayan, Jordi Izzard Andaya; Manaloto, Adrian Carlos Francisco; Lee, Jeong-Yol; Shin, Sang-Wan

    2014-04-01

    The aim of this in vitro study was to evaluate the effect of aging on the tear strength and cytotoxicity of four soft denture lining materials. Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for tear strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). Before thermocycling, Sofreliner Tough M (10.36 ± 1.00 N) had the highest tear strength value while Coe-Comfort™ (0.46 ± 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 ± 1.66 N) presented the highest value and Coe-Comfort™ (0.42 ± 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort™, Coe-Soft™, and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. This in vitro study revealed that aging can affect both the tear strength and cytotoxicity of soft denture materials depending on the composition.

  4. Repair bond strength in aged methacrylate- and silorane-based composites.

    PubMed

    Bacchi, Atais; Consani, Rafael Leonardo; Sinhoreti, Mario Alexandre; Feitosa, Victor Pinheiro; Cavalcante, Larissa Maria; Pfeifer, Carmem Silva; Schneider, Luis Felipe

    2013-10-01

    To evaluate the tensile bond strength at repaired interfaces of aged dental composites, either dimethacrylate- or silorane-based, when subjected to different surface treatments. The composites used were Filtek P60 (methacrylate-based, 3M ESPE) and Filtek P90 (silorane-based, 3M ESPE), of which 50 slabs were stored for 6 months at 37°C. The surface of adhesion was abraded with a 600-grit silicone paper and the slabs repaired with the respective composite, according to the following surface treatment protocols: G1: no treatment; G2: adhesive application; G3: silane + adhesive; G4: sandblasting (Al2O3) + adhesive; G5: sandblasting (Al2O3) + silane + adhesive. After 24-h storage in distilled water at 37°C, tensile bond strength (TBS) was determined in a universal testing machine (Instron 4411) at a crosshead speed of 0.5 mm/min. The original data were submitted to two-way ANOVA and Tukey's test (α = 5%). The methacrylate-based composite presented a statistically significantly higher repair potential than did the silorane-based resin (p = 0.0002). Of the surface treatments for the silorane-based composite, aluminum-oxide air abrasion and adhesive (18.5 ± 3.3MPa) provided higher bond strength than only adhesive application or the control group without surface treatment. For Filtek P60, the control without treatment presented lower repair strength than all other groups with surface treatments, which were statistically similar to each other. The interaction between the factors resin composite and surface treatment was significant (p = 0.002). For aged silorane-based materials, repairs were considered successful after sandblasting (Al2O3) and adhesive application. For methacrylate resin, repair was successful with all surface treatments tested.

  5. Changes in the stiffness, strength, and toughness of human cortical bone with age.

    PubMed

    Zioupos, P; Currey, J D

    1998-01-01

    Aging adversely affects the elastic and ultimate properties of human cortical bone as seen in uniaxial tests in quasi static loading, high strain rate impact or fatigue. Little is known about the full effects of aging on toughness and its relationship with strength. In the present article the elastic modulus (E), strength (sigma f), fracture toughness (KC and J-integral), and work of fracture (Wf) were determined in specimens of male human femoral bone aged between 35-92 years. In this way we investigated whether fracture of bone in three situations, allowing various amounts of damage prior to fracture, can provide a better insight into the fracture process and also the relative importance of these experimental methods for assessing the soundness of bone material. We found a steady and significant decrease with age for all these mechanical measures. E fell by 2.3%, from its value of 15.2 GPa at 35 years of age, per decade of later life; sigma f fell similarly from 170 MPa by 3.7%; KC from 6.4 MPa m1/2 by 4.1%; J-integral from 1.2 kJ m-2 by 3%, and the Wf from 3.4 kJ m-2 by 8.7%. In aging bone there was a deterioration in the elastic properties of the material. This reduced the (elastically calculated) critical stress intensity level (KC) required to initiate a macrocrack, or the nonlinear energy associated with the onset of fracture (J). The macrocrack was preceded by less damage, and once created needed less energy to drive through the tissue (Wf).

  6. Moulding Faces at an Early Age-A Case Series

    PubMed Central

    Sunny, Sunil; Mathew, Neethu; Parambath, Anvar Kizhakke; Madhusudanan, Amla

    2016-01-01

    Certain malocclusions have to be treated at an early age to avoid surgeries for the correction in the future. Introduction of functional appliances has reduced the elimination and correction of skeletal as well as dental discrepancies. Proper case selection taking into consideration skeletal and dental age with the use of various diagnostic aids helps us to identify and treat the malocclusions before it is too late. In this case series, we report three patients with skeletal jaw malrelationship treated with functional and orthopaedic appliances. PMID:27656599

  7. Emotional support from parents early in life, aging, and health.

    PubMed

    Shaw, Benjamin A; Krause, Neal; Chatters, Linda M; Connell, Cathleen M; Ingersoll-Dayton, Berit

    2004-03-01

    The purpose of this study is to estimate the relationship between receiving emotional support from parents early in life and an individual's health in adulthood. Analysis of data from a nationally representative sample of adults ages 25-74 years suggests that a lack of parental support during childhood is associated with increased levels of depressive symptoms and chronic conditions in adulthood. These associations between early parental support and adult health persist with increasing age throughout adulthood. Personal control, self-esteem, and social relationships during adulthood account for a large portion of these long-term associations. These findings underscore the importance of adopting a life course perspective in studying the social determinants of health among adults.

  8. Solubility and strength of zirconia-based dental materials after artificial aging.

    PubMed

    Kvam, Ketil; Karlsson, Stig

    2013-10-01

    Advanced high-strength dental ceramics based on zirconium oxide are widely used for dental restorations. However, their durability in liquids has been questioned. The purpose of this study was to compare the flexure strength of zirconium dioxide materials designed for different sintering techniques before and after surface exposure to an acidic solution and to correlate the dissolution of the materials with strength data. An accelerated aging test, immersion in hot (80°C) 4 vol% acetic acid was used to study the solubility of elements from the surface and the effect on the strength of 3 dental zirconia products: DY: Y-TZP material, milled in HIPed state (Denzir); DM: Mg-PSZ material, milled in dense-sintered state (Denzir M); and CY: Y-TZP material, milled from presintered block and then dense-sintered (Cercon base). Disks were prepared with a surface conditioning as for copings provided for dental restorations. After immersion for 1 week, the liquid was analyzed for a range of elements with ICP-MS. Biaxial flexure strength was measured for 3 samples (n=15) of each material: ground on a 20 µm diamond disk without immersion; after 1 week's immersion in acetic acid; and after 1 week's immersion, grinding, and 1 more week in acid. Fracture probability was analyzed by maximum likelihood attribution of individual measurements to 1 or 2 Weibull distributions, each with 2 free parameters. Dissolution was found to be limited. The total mass loss was less than 0.7 µg/cm(2) for Y-TZP and 3.5 µg/cm(2) for Mg-PSZ. The mean strength was reduced for all materials after immersion in the fluid. Weibull statistics revealed 2 fracture mechanisms in Y-TZP milled in fully sintered condition. For DY only, 2 distributions significantly (P>.99) improved the description of individual treatment data. Y-TZP materials showed the highest biaxial flexure strength. Immersion for 1 week in hot 4 vol% acetic acid weakened all 3 zirconia materials by 100 to 200 MPa. Milling in the presintered

  9. Ages and Ages: The Multiplication of Children's "Ages" in Early Twentieth-Century Child Psychology

    ERIC Educational Resources Information Center

    Beauvais, Clementine

    2016-01-01

    This paper explores the trend, between 1905 and the late 1920s in UK and US child psychology, of "discovering," labelling and calculating different "ages" in children. Those new "ages"--from mental to emotional, social, anatomical ages, and more--were understood as either replacing, or meaningfully related to,…

  10. Ages and Ages: The Multiplication of Children's "Ages" in Early Twentieth-Century Child Psychology

    ERIC Educational Resources Information Center

    Beauvais, Clementine

    2016-01-01

    This paper explores the trend, between 1905 and the late 1920s in UK and US child psychology, of "discovering," labelling and calculating different "ages" in children. Those new "ages"--from mental to emotional, social, anatomical ages, and more--were understood as either replacing, or meaningfully related to,…

  11. A randomized two-year study of the effects of dynamic strength training on muscle strength, disease activity, functional capacity, and bone mineral density in early rheumatoid arthritis.

    PubMed

    Häkkinen, A; Sokka, T; Kotaniemi, A; Hannonen, P

    2001-03-01

    (and subsequent use of oral glucocorticoids) remained constantly at a statistically significantly lower level than that in the other 45 patients. Regular dynamic strength training combined with endurance-type physical activities improves muscle strength and physical function, but not BMD, in patients with early RA, without detrimental effects on disease activity.

  12. Identification of morphological markers of sarcopenia at early stage of aging in skeletal muscle of mice.

    PubMed

    Sayed, Ramy K A; de Leonardis, Erika Chacin; Guerrero-Martínez, José A; Rahim, Ibtissem; Mokhtar, Doaa M; Saleh, Abdelmohaimen M; Abdalla, Kamal E H; Pozo, María J; Escames, Germaine; López, Luis C; Acuña-Castroviejo, Darío

    2016-10-01

    The gastrocnemius muscle (GM) of young (3months) and aged (12months) female wild-type C57/BL6 mice was examined by light and electron microscopy, looking for the presence of structural changes at early stage of the aging process. Morphometrical parameters including body and gastrocnemius weights, number and type of muscle fibers, cross section area (CSA), perimeter, and Feret's diameter of single muscle fiber, were measured. Moreover, lengths of the sarcomere, A-band, I-band, H-zone, and number and CSA of intermyofibrillar mitochondria (IFM), were also determined. The results provide evidence that 12month-old mice had significant changes on skeletal muscle structure, beginning with the reduction of gastrocnemius weight to body weight ratio, compatible with an early loss of skeletal muscle function and strength. Moreover, light microscopy revealed increased muscle fibers size, with a significant increase on their CSA, perimeter, and diameter of both type I and type II muscle fibers, and a reduction in the percentage of muscle area occupied by type II fibers. Enhanced connective tissue infiltrations, and the presence of centrally nucleated muscle fibers, were also found in aged mice. These changes may underlie an attempt to compensate the loss of muscle mass and muscle fibers number. Furthermore, electron microscopy discovered a significant age-dependent increase in the length of sarcomeres, I and H bands, and reduction on the overlapped actin/myosin length, supporting contractile force loss with age. Electron microscopy also showed an increased number and CSA of IFM with age, which may reveal more endurance at 12months of age. Together, mice at early stage of aging already show significant changes in gastrocnemius muscle morphology and ultrastructure that are suggestive of the onset of sarcopenia. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Tooth loss early in life accelerates age-related bone deterioration in mice.

    PubMed

    Kurahashi, Minori; Kondo, Hiroko; Iinuma, Mitsuo; Tamura, Yasuo; Chen, Huayue; Kubo, Kin-ya

    2015-01-01

    Both osteoporosis and tooth loss are health concerns that affect many older people. Osteoporosis is a common skeletal disease of the elderly, characterized by low bone mass and microstructural deterioration of bone tissue. Chronic mild stress is a risk factor for osteoporosis. Many studies showed that tooth loss induced neurological alterations through activation of a stress hormone, corticosterone, in mice. In this study, we tested the hypothesis that tooth loss early in life may accelerate age-related bone deterioration using a mouse model. Male senescence-accelerated mouse strain P8 (SAMP8) mice were randomly divided into control and toothless groups. Removal of the upper molar teeth was performed at one month of age. Bone response was evaluated at 2, 5 and 9 months of age. Tooth loss early in life caused a significant increase in circulating corticosterone level with age. Osteoblast bone formation was suppressed and osteoclast bone resorption was activated in the toothless mice. Trabecular bone volume fraction of the vertebra and femur was decreased in the toothless mice with age. The bone quality was reduced in the toothless mice at 5 and 9 months of age, compared with the age-matched control mice. These findings indicate that tooth loss early in life impairs the dynamic homeostasis of the bone formation and bone resorption, leading to reduced bone strength with age. Long-term tooth loss may have a cumulative detrimental effect on bone health. It is important to take appropriate measures to treat tooth loss in older people for preventing and/or treating senile osteoporosis.

  14. Mechanical Properties of Mass Concrete at Early Ages

    DTIC Science & Technology

    1991-08-01

    material properties during the time that concrete is undergoing the greatest amount of thermal activity and physical change (i.e. early ages, less than 3...Type II, low alkali (LA) portland cement meeting ASTM C 150 and a Class C fly ash meeting ASTM C 618 [11 i]. The fine aggregate was a natural sand...usually require that specially developed or modified models be used. It should also be noted that the use- of high percentages of pozzolans in mass

  15. Emphysema, airflow limitation, and early age-related macular degeneration.

    PubMed

    Klein, Ronald; Knudtson, Michael D; Klein, Barbara E K; Wong, Tien Y; Cotch, Mary Frances; Barr, Graham

    2010-04-01

    To describe the associations of lung function and emphysema, measured with spirometry and computed tomography (CT), with early age-related macular degeneration (AMD) in a sample of white, black, Hispanic, and Chinese subjects. Three thousand three hundred ninety-nine persons aged 45 to 84 years residing in 6 US communities participated in a period cross-sectional study. Age-related macular degeneration was measured from digital retinal photographs at the second Multi-Ethnic Study of Atherosclerosis (MESA) examination. Forced expiratory volume in 1 second (FEV(1)) and FEV(1) to forced vital capacity (FVC) ratio were measured at the third or fourth MESA examination. Percent emphysema was measured from cardiac CT scans at baseline. Apical and basilar lung segments were defined as the cephalad or caudal regions of the lung on the cardiac CT scan. Logistic regression models were used to examine the association of lung function and structure with AMD, controlling for age, sex, and other factors. The prevalence of early AMD was 3.7%. Early AMD was not associated with FEV(1) (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.58-1.15; P = .25), FEV(1):FVC ratio (OR, 0.92; 95% CI, 0.76-1.12; P = .43), percent emphysema (OR, 1.13; 95% CI, 0.91-1.40; P = .26), and apical-basilar difference in percent emphysema (OR, 1.14; 95% CI, 0.95-1.37; P = .17). Associations were stronger in smokers. Apical-basilar difference in percent emphysema was significantly associated with early AMD among those who ever smoked (OR, 1.28; 95% CI, 1.02-1.60; P = .03). Associations were not modified by race/ethnicity. Lung function and emphysema on CT scan were not cross-sectionally associated with AMD; this might be explained by the relatively low smoking exposure in this cohort.

  16. Aging Behavior of High-Strength Al Alloy 2618 Produced by Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Casati, Riccardo; Lemke, Jannis Nicolas; Alarcon, Adrianni Zanatta; Vedani, Maurizio

    2017-02-01

    High Si-bearing Al alloys are commonly used in additive manufacturing, but they have moderate mechanical properties. New high-strength compositions are necessary to spread the use of additively manufactured Al parts for heavy-duty structural applications. This work focuses on the microstructure, mechanical behavior, and aging response of an Al alloy 2618 processed by selective laser melting. Calorimetric analysis, electron microscopy, and compression tests were performed in order to correlate the mechanical properties with the peculiar microstructure induced by laser melting and thermal treatments

  17. Structure and properties during aging of an ultra-high strength Al-Cu-Li-Ag-Mg alloy

    NASA Technical Reports Server (NTRS)

    Gayle, Frank W.; Heubaum, Frank H.; Pickens, Joseph R.

    1990-01-01

    The structure and properties of the strengthening phases formed during aging in an Al-Cu-Li-Ag-Mg alloy (Weldalite 049) were elulcidated, by following the development of the microstructure by means of TEM. The results of observations showed that the Weldalite 049 alloy has a series of unusual and technologically useful combinations of mechanical properties in different aging conditions, such as natural aging without prior cold work to produce high strengths, a reversion temper of lower yield strength and unusually high ductility, a room temperature reaging of the reversion temper eventually leading to the original T4 hardness, and ultrahigh-strength T6 properties.

  18. Prepubertal stature and blood pressure in early old age

    PubMed Central

    Montgomery, S.; Berney, L.; Blane, D.

    2000-01-01

    AIMS—To test the hypothesis that childhood growth rate is a marker for formation of control mechanisms that influence blood pressure in early old age.
METHODS—Data are from a sample of 149 (74 male) members of Sir John Boyd Orr's survey of British families conducted between 1937 and 1939. Measured heights were collected between ages 5 and 8 years, and in early old age between 1997 and 1998. Multiple linear regression investigated the relations of blood pressure with age and sex standardised childhood height with adjustment for potential confounding factors, including adult height. Inclusion of both childhood and adult heights in the same model was used to estimate growth, as measures of childhood height are relative to adult height.
RESULTS—Mean blood pressures in early old age for those in the shortest childhood height fifth were 167.8 and 76.3 mm Hg for systolic blood pressure and pulse pressure, respectively. For the tallest fifth they were 150.8 and 63.7 mm Hg, respectively. After adjustment for potential confounding factors including adult height, the mean increase for the shortest childhood height fifth compared with the tallest was 28.5 mm Hg for systolic pressure (p = 0.015) and 22.8 mm Hg (p = 0.010) for pulse pressure. The relations of blood pressure with adult height were not statistically significant in the adjusted models.
CONCLUSION—Prepubertal growth rate is associated with the formation of mechanisms associated with the control of blood pressure in later life.

 PMID:10799423

  19. High Strength and Good Ductility in Cu-3Ag-0.5Zr Alloy by Cryo-Rolling and Aging

    NASA Astrophysics Data System (ADS)

    Krishna, S. Chenna; Chawake, Niraj; Kottada, Ravi Sankar; Jha, Abhay K.; Pant, Bhanu; Venkitakrishnan, P. V.

    2017-01-01

    A combination of high strength and good ductility was achieved in a precipitation hardenable Cu-3Ag-0.5Zr alloy through cryo-rolling (80% reduction in thickness) and aging in the temperature range (200-500 °C). The high-strength sheets produced by cryo-rolling showed a threefold increase in yield strength compared to that of the solution-treated and aged (220 MPa) sample, while retaining good ductility. An optimum combination of high strength (614 MPa) and ductility (8%) was achieved by 80% cryo-rolling and aging at 320 °C for 1 h. The high strength and good ductility obtained was attributed to various microstructural factors such as deformation twins, ultra-fine grains, high dislocation density and fine nano-sized silver precipitates.

  20. Age of acquisition in sport: starting early matters.

    PubMed

    Hernandez, Arturo E; Mattarella-Micke, Andrew; Redding, Richard W T; Woods, Elizabeth A; Beilock, Sian

    2011-01-01

    Although the age at which a skill is learned (age of acquisition [AoA]) is one of the most studied predictors of success in domains ranging from language to music, very little work has focused on this factor in sports. In order to uncover how the age at which a skill is learned relates to how athletes cognitively represent that skill, we asked a group of skilled golfers who learned to play golf before (early learners) or after (late learners) the age of 10 to take a series of putts on an indoor putting green. Golfers putted in isolation (single-task condition), while monitoring a stream of words presented over a loudspeaker (dual-task condition), or while being instructed to attend to specific aspects of their golf swing (skill-focused condition). Early and late learners putted equally well in the single-task and dual-task conditions. However, in the skill-focused condition, golfers who learned earlier performed worse than those who learned later. The results are consistent with the notion that AoA influences the manner in which sports, like other domains such as language and music, are represented in memory.

  1. Hybrid embryos of Vicia faba develop enhanced sink strength, which is established during early development.

    PubMed

    Meitzel, Tobias; Radchuk, Ruslana; Nunes-Nesi, Adriano; Fernie, Alisdair R; Link, Wolfgang; Weschke, Winfriede; Weber, Hans

    2011-02-01

    Selfed and crossed seeds of two homozygous Vicia faba lines served as models for the analysis of the physiological and molecular mechanisms underlying embryo heterosis. Profiles of transcripts, metabolites and seed contents of developing embryos were analysed to compare the means of reciprocally crossed and selfed seeds growing on the same mother plants. The mean weight of mature hybrid seeds was demonstrably higher, revealing mid-parent heterosis. Hybrid embryos exhibited a prolonged early phase of development and delayed onset of storage activity. Accordingly, transcript profiling indicates stimulation of cell proliferation, an effect, which is potentially mediated by activation of auxin functions within a framework of growth-related transcription factors. At the transcript level, activated cell proliferation increased assimilate uptake activity and thereby seed sink strength. This situation might finally lead to the increased size of the hybrid seeds. We conclude that hybrid seeds are characterised by accelerated growth during early development, which increases storage capacity and leads to higher metabolic fluxes. These needs are, at least partially, met by increased assimilate uptake capacity. The stimulated growth of hybrid seeds shifted metabolite profiles and potentially depleted available pools. Such metabolic shifts are most likely secondary effects resulting from the higher storage capacity of hybrid seeds, a heterotic feature, which is itself established very early in seed development.

  2. Resistance training for explosive and maximal strength: effects on early and late rate of force development.

    PubMed

    Oliveira, Felipe B D; Oliveira, Anderson S C; Rizatto, Guilherme F; Denadai, Benedito S

    2013-01-01

    The aim of the present study was to verify whether strength training designed to improve explosive and maximal strength would influence rate of force development (RFD). Nine men participated in a 6-week knee extensors resistance training program and 9 matched subjects participated as controls. Throughout the training sessions, subjects were instructed to perform isometric knee extension as fast and forcefully as possible, achieving at least 90% maximal voluntary contraction as quickly as possible, hold it for 5 s, and relax. Fifteen seconds separated each repetition (6-10), and 2 min separated each set (3). Pre- and post-training measurements were maximal isometric knee extensor (MVC), RFD, and RFD relative to MVC (i.e., %MVC·s(-1)) in different time-epochs varying from 10 to 250 ms from the contraction onset. The MVC (Nm) increased by 19% (275.8 ± 64.9 vs. 329.8 ± 60.4, p < 0.001) after training. In addition, RFD (Nm·s(-1)) increased by 22-28% at time epochs up to 20 ms from the contraction onset (0-10 ms = 1679. 1 ± 597.1 vs. 2159.2 ± 475.2, p < 0.001; 0-20 ms = 1958.79 ± 640.3 vs. 2398.4 ± 479.6, p < 0. 01), with no changes verified in later time epochs. However, no training effects on RFD were found for the training group when RFD was normalized to MVC. No changes were found in the control group. In conclusion, very early and late RFD responded differently to a short period of resistance training for explosive and maximal strength. This time-specific RFD adaptation highlight that resistance training programs should consider the specific neuromuscular demands of each sport. Key PointsThe time-specific RFD adaptation evoked by resistance training highlight that the method of analyzing RFD is essential for the interpretation of results.Confirming previous data, maximal contractile RFD and maximal force can be differently influenced by resistance training. Thus, the resistance training programs should consider the specific neuromuscular demands of each

  3. Resistance Training for Explosive and Maximal Strength: Effects on Early and Late Rate of Force Development

    PubMed Central

    Oliveira, Felipe B.D.; Oliveira, Anderson S.C.; Rizatto, Guilherme F.; Denadai, Benedito S.

    2013-01-01

    The aim of the present study was to verify whether strength training designed to improve explosive and maximal strength would influence rate of force development (RFD). Nine men participated in a 6-week knee extensors resistance training program and 9 matched subjects participated as controls. Throughout the training sessions, subjects were instructed to perform isometric knee extension as fast and forcefully as possible, achieving at least 90% maximal voluntary contraction as quickly as possible, hold it for 5 s, and relax. Fifteen seconds separated each repetition (6-10), and 2 min separated each set (3). Pre- and post-training measurements were maximal isometric knee extensor (MVC), RFD, and RFD relative to MVC (i.e., %MVC·s-1) in different time-epochs varying from 10 to 250 ms from the contraction onset. The MVC (Nm) increased by 19% (275.8 ± 64.9 vs. 329.8 ± 60.4, p < 0.001) after training. In addition, RFD (Nm·s-1) increased by 22-28% at time epochs up to 20 ms from the contraction onset (0-10 ms = 1679. 1 ± 597.1 vs. 2159.2 ± 475.2, p < 0.001; 0-20 ms = 1958.79 ± 640.3 vs. 2398.4 ± 479.6, p < 0. 01), with no changes verified in later time epochs. However, no training effects on RFD were found for the training group when RFD was normalized to MVC. No changes were found in the control group. In conclusion, very early and late RFD responded differently to a short period of resistance training for explosive and maximal strength. This time-specific RFD adaptation highlight that resistance training programs should consider the specific neuromuscular demands of each sport. Key Points The time-specific RFD adaptation evoked by resistance training highlight that the method of analyzing RFD is essential for the interpretation of results. Confirming previous data, maximal contractile RFD and maximal force can be differently influenced by resistance training. Thus, the resistance training programs should consider the specific neuromuscular demands of each sport

  4. The effects of strength training and raloxifene on bone health in aging ovariectomized rats.

    PubMed

    Stringhetta-Garcia, Camila Tami; Singulani, Monique Patrício; Santos, Leandro Figueiredo; Louzada, Mário Jefferson Quirino; Nakamune, Ana Cláudia Stevanato; Chaves-Neto, Antonio Hernandes; Rossi, Ana Cláudia; Ervolino, Edilson; Dornelles, Rita Cássia Menegati

    2016-04-01

    The aim of this study was to investigate the effects of strength training (ST) and raloxifene (Ral), alone or in combination, on the prevention of bone loss in an aging estrogen-deficient rat model. Aging Wistar female rats were ovariectomized at 14months and allocated to four groups: (1) non-trained and treated with vehicle, NT-Veh; (2) strength training and treated with vehicle, ST-Veh; (3) non-trained and treated with raloxifene, NT-Ral; and (4) strength training and treated with raloxifene, ST-Ral. ST was performed on a ladder three times per week and Ral was administered daily by gavage (1mg/kg/day), both for 120days. Areal bone mineral density (aBMD), strength, microarchitecture, and biomarkers (osteocalcin, OCN; osteoprotegerin, OPG; and tartrate-resistant acid phosphatase, TRAP) were assessed. Immunohistochemistry was performed for runt-related transcription factor 2 (RUNX2), osterix (OSX), OCN, OPG, TRAP, and receptor activator of nuclear factor kappa-B ligand (RANKL). The rats that performed ST (ST-Veh) or were treated with Ral (NT-Ral) showed significant improvements in aBMD (p=0.001 and 0.004), bone strength (p=0.001), and bone microarchitecture, such as BV/TV (%) (p=0.001), BS/TV (mm(2)/mm(3)) (p=0.023 and 0.002), Conn.Dn (1/mm(3)) (p=0.001), Tb.N (1/mm) (p=0.012 and 0.011), Tb.Th (1/mm) (p=0.001), SMI (p=0.001 and 0.002), Tb.Sp (p=0.001), and DA (p=0.002 and 0.007); there was also a significant decrease in plasma levels of OCN (p=0.001 and 0.002) and OPG (p=0.003 and 0.014), compared with animals in the NT-Veh group. Ral, with or without ST, promoted an increased immunolabeling pattern for RUNX2 (p=0.0105 and p=0.0006) and OSX (p=0.0105), but a reduced immunolabeling pattern for TRAP (p=0.0056) and RANKL (p=0.033 and 0.004). ST increased the immunolabeling pattern for RUNX2 (p=0.0105), and association with Ral resulted in an increased immunolabeling pattern for OPG (p=0.0034) and OCN (p=0.0024). In summary, ST and Ral administration in aged, estrogen

  5. Effects of combined strength and endurance training on treadmill load carrying walking performance in aging men.

    PubMed

    Holviala, Jarkko; Häkkinen, Arja; Karavirta, Laura; Nyman, Kai; Izquierdo, Mikel; Gorostiaga, Esteban M; Avela, Janne; Korhonen, Janne; Knuutila, Veli-Pekka; Kraemer, William J; Häkkinen, Keijo

    2010-06-01

    The present study examined the effects of twice weekly total body strength training (ST), endurance cycling (ET), and combined ST and ET (2+2 times a week) (SET) training on the load carrying walking test performance on the treadmill (TM) and changes in neuromuscular and endurance performance during a 21-week training period in aging men. Forty healthy men (54.8+/-8.0 years) were divided into 3 training groups (ET n=9, ST n=11, SET n=11) and a control group (C, n=9). Peak oxygen uptake (VO2peak), heart rate, and blood lactate concentration were measured before and after a 21-week training program using a graded TM and maximal incremental bicycle ergometer (BE) tests. Isometric forces, vertical jump, and electromyographic activity of leg extensor and/or forearm flexor (F) muscles were measured before and after training and the TM tests. Increases of 20-21% in strength and of 7-12% in cycling BE VO2peak occurred in the training groups, whereas the changes of C remained minor. VO2peak was associated, both before and after training, with TM exercise time in all groups (from r=0.65, p=0.030 to r=0.93, p<0.001). Only SET showed a significant training-induced increase (p=0.011) in exercise time of the TM walking with no significant increase in TM VO2peak. The present data suggest that in older men ET and SET induced specific increases in BE VO2peak and ST and SET in strength. However, only SET increased walking exercise time indicating improved load carrying walking performance because of large individual differences in the magnitude of the development of either strength or endurance capacities.

  6. Known for My Strengths: Positive Traits of Transition-Age Youth With Intellectual Disability and/or Autism

    ERIC Educational Resources Information Center

    Carter, Erik W.; Boehm, Thomas L.; Biggs, Elizabeth E.; Annandale, Naomi H.; Taylor, Courtney E.; Loock, Aimee K.; Liu, Rosemary Y.

    2015-01-01

    Can young people with intellectual and developmental disabilities be known for their strengths? This mixed-method study explored the strengths of 427 youth and young adults with intellectual disability and/or autism (ages 13-21) from the vantage point of their parents. Using the Assessment Scale for Positive Character Traits-Developmental…

  7. Known for My Strengths: Positive Traits of Transition-Age Youth With Intellectual Disability and/or Autism

    ERIC Educational Resources Information Center

    Carter, Erik W.; Boehm, Thomas L.; Biggs, Elizabeth E.; Annandale, Naomi H.; Taylor, Courtney E.; Loock, Aimee K.; Liu, Rosemary Y.

    2015-01-01

    Can young people with intellectual and developmental disabilities be known for their strengths? This mixed-method study explored the strengths of 427 youth and young adults with intellectual disability and/or autism (ages 13-21) from the vantage point of their parents. Using the Assessment Scale for Positive Character Traits-Developmental…

  8. Age Differences in Self-Concept from Early Adulthood through Old Age.

    ERIC Educational Resources Information Center

    Grant, Carmen Hill

    Several works have suggested that life proceeds in a pattern of developmental stages characterized by expansion during the early adult years and restriction, or withdrawal, after middle age. Postulating that self-concept might also be expected to reflect this curvilinear pattern of life stages, the author explored differences in adult self-concept…

  9. Comprehensive analyses of how tubule occlusion and advanced glycation end-products diminish strength of aged dentin

    PubMed Central

    Shinno, Yuko; Ishimoto, Takuya; Saito, Mitsuru; Uemura, Reo; Arino, Masumi; Marumo, Keishi; Nakano, Takayoshi; Hayashi, Mikako

    2016-01-01

    In clinical dentistry, since fracture is a major cause of tooth loss, better understanding of mechanical properties of teeth structures is important. Dentin, the major hard tissue of teeth, has similar composition to bone. In this study, we investigated the mechanical properties of human dentin not only in terms of mineral density but also using structural and quality parameters as recently accepted in evaluating bone strength. Aged crown and root dentin (age ≥ 40) exhibited significantly lower flexural strength and toughness than young dentin (age < 40). Aged dentin, in which the dentinal tubules were occluded with calcified material, recorded the highest mineral density; but showed significantly lower flexural strength than young dentin. Dentin with strong alignment of the c-axis in hydroxyapatite exhibited high fracture strength, possibly because the aligned apatite along the collagen fibrils may reinforce the intertubular dentin. Aged dentin, showing a high advanced glycation end-products (AGEs) level in its collagen, recorded low flexural strength. We first comprehensively identified significant factors, which affected the inferior mechanical properties of aged dentin. The low mechanical strength of aged dentin is caused by the high mineral density resulting from occlusion of dentinal tubules and accumulation of AGEs in dentin collagen. PMID:26797297

  10. Comprehensive analyses of how tubule occlusion and advanced glycation end-products diminish strength of aged dentin

    NASA Astrophysics Data System (ADS)

    Shinno, Yuko; Ishimoto, Takuya; Saito, Mitsuru; Uemura, Reo; Arino, Masumi; Marumo, Keishi; Nakano, Takayoshi; Hayashi, Mikako

    2016-01-01

    In clinical dentistry, since fracture is a major cause of tooth loss, better understanding of mechanical properties of teeth structures is important. Dentin, the major hard tissue of teeth, has similar composition to bone. In this study, we investigated the mechanical properties of human dentin not only in terms of mineral density but also using structural and quality parameters as recently accepted in evaluating bone strength. Aged crown and root dentin (age ≥ 40) exhibited significantly lower flexural strength and toughness than young dentin (age < 40). Aged dentin, in which the dentinal tubules were occluded with calcified material, recorded the highest mineral density; but showed significantly lower flexural strength than young dentin. Dentin with strong alignment of the c-axis in hydroxyapatite exhibited high fracture strength, possibly because the aligned apatite along the collagen fibrils may reinforce the intertubular dentin. Aged dentin, showing a high advanced glycation end-products (AGEs) level in its collagen, recorded low flexural strength. We first comprehensively identified significant factors, which affected the inferior mechanical properties of aged dentin. The low mechanical strength of aged dentin is caused by the high mineral density resulting from occlusion of dentinal tubules and accumulation of AGEs in dentin collagen.

  11. Slab Deformation in the Mantle Transition Zone: The Effect of Plate Age and Strength Evolution

    NASA Astrophysics Data System (ADS)

    Goes, S. D. B.; Garel, F.; Davies, R.; Davies, J. H.; Kramer, S. C.; Wilson, C. R.

    2014-12-01

    The deformation encountered by subducted tectonic plates at the base of the upper mantle influences Earth's thermal, chemical, and tectonic evolution. Yet the mechanisms responsible for the wide range of imaged slab morphologies, either stagnating in the transition zone or penetrating into the lower mantle, remain debated. We use 2-D thermo-mechanical models of a two-plate subduction system, modeled with the finite-element, adaptive-mesh code Fluidity. We implement a temperature- and stress-dependent rheology, and viscosity increases 30-fold from upper to lower mantle. Trench position evolves freely in response to plate dynamics. Such an approach self-consistently captures feedbacks between temperature, density, flow, strength and deformation. Our results indicate that key controls on subduction dynamics and slab morphology are: (i) the evolution of slab strength; and (ii) the slab's ability to induce trench motion. We build a regime diagram that distinguishes four subduction styles: (1) a "vertical folding" mode with stationary trench; (2) young slabs that are "horizontally deflected" along the 660-km deep viscosity jump ; (3) an inclined slab morphology, resulting from strong trench retreat (old slabs and thinner overriding plates); and (4) a two-stage mode, displaying bent (rolled-over) slabs at the end of upper-mantle descent, that subsequently unbend and achieve inclined morphologies, with late trench retreat (strong overriding plates). We find that the interplay between trench motion and slab deformation at depth dictates the subduction style, both being controlled by slab strength. We show that all seismically observed slab morphologies in the transition zone can arise just by changing the subducting-plate ages. However, to understand present-day slab morphologies, we have to analyse subduction history rather than just current age at the trench.

  12. Age and response bias: evidence from the strength-based mirror effect.

    PubMed

    Criss, Amy H; Aue, William; Kılıç, Aslı

    2014-10-01

    Performance in episodic memory is determined both by accurate retrieval from memory and by decision processes. A substantial body of literature suggests slightly poorer episodic memory accuracy for older than younger adults; however, age-related changes in the decision mechanisms in memory have received much less attention. Response bias, the willingness to endorse an item as remembered, is an important decision factor that contributes to episodic memory performance, and therefore understanding age-related changes in response bias is critical to theoretical development. We manipulate list strength in order to investigate two aspects of response bias. First, we evaluate whether criterion placement in episodic memory differs for older and younger adults. Second, we ask whether older adults have the same degree of flexibility to adjust the criterion in response to task demands as younger adults. Participants were tested on weakly and strongly encoded lists where word frequency (Experiment 1) or similarity between targets and foils (Experiment 2) was manipulated. Both older and younger adults had higher hit rates and lower false-alarm rates for strong lists than for weak lists (i.e., a strength-based mirror effect). Older adults were more conservative (less likely to endorse an item as studied) than younger adults, and we found no evidence that older and younger adults differ in their ability to flexibly adjust their criterion based on the demands of the task.

  13. Relationships among the Y balance test, Berg Balance Scale, and lower limb strength in middle-aged and older females

    PubMed Central

    Lee, Dong-Kyu; Kang, Min-Hyeok; Lee, Tae-Sik; Oh, Jae-Seop

    2015-01-01

    Background: Older females have less dynamic postural control and muscle strength than do middle-aged females. Aging-related strength losses may limit balancing performance. Objective: The purpose of this study was to investigate the ability of the Y Balance Test (YBT) and lower limb strength to discriminate between females in 2 age groups, the relationship between YBT distance and the Berg Balance Scale (BBS), and the degree to which performance on YBT distance is related to lower limb strength in middle-aged and older females. Method: The 40 healthy, independently active females were divided into 2 groups: older and middle-aged. The participants underwent measurements of YBT distance using the YBT, maximal muscular strength of the lower limbs using a handheld dynamometer, and the BBS. Results: The YBT distance in 3 directions and lower limb muscle strength for both lower limbs were significantly lower in the older adults than in the middle-aged group. A moderate correlation but insignificant correlation was found between the YBT composite distance and the BBS score. In the older females, YBT distance was significantly positively correlated with strength of the knee flexor and hip abductor. In the middle-aged group, YBT distance was significantly positively correlated with strength of the knee flexor and hip extensor. Conclusions: Performance on the YBT was influenced by the strength of lower limb. We suggested that YBT can be used to alternative as a measurement of dynamic balance. Proper training programs for older people could include not only strengthening exercises but also YBT performance to improve balance. PMID:26039033

  14. Sex and Age Effects of Functional Connectivity in Early Adulthood

    PubMed Central

    Zhang, Chao; Cahill, Nathan D.; Arbabshirani, Mohammad R.; White, Tonya; Baum, Stefi A.

    2016-01-01

    Abstract Functional connectivity (FC) in resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to find coactivating regions in the human brain. Despite its widespread use, the effects of sex and age on resting FC are not well characterized, especially during early adulthood. Here we apply regression and graph theoretical analyses to explore the effects of sex and age on FC between the 116 AAL atlas parcellations (a total of 6670 FC measures). rs-fMRI data of 494 healthy subjects (203 males and 291 females; age range: 22–36 years) from the Human Connectome Project were analyzed. We report the following findings. (1) Males exhibited greater FC than females in 1352 FC measures (1025 survived Bonferroni correction; \\documentclass{aastex}\\usepackage{amsbsy}\\usepackage{amsfonts}\\usepackage{amssymb}\\usepackage{bm}\\usepackage{mathrsfs}\\usepackage{pifont}\\usepackage{stmaryrd}\\usepackage{textcomp}\\usepackage{portland, xspace}\\usepackage{amsmath, amsxtra}\\pagestyle{empty}\\DeclareMathSizes{10}{9}{7}{6}\\begin{document} $$p < 7.49{ \\rm{E}} - 6$$ \\end{document}). In 641 FC measures, females exhibited greater FC than males but none survived Bonferroni correction. Significant FC differences were mainly present in frontal, parietal, and temporal lobes. Although the average FC values for males and females were significantly different, FC values of males and females exhibited large overlap. (2) Age effects were present only in 29 FC measures and all significant age effects showed higher FC in younger subjects. Age and sex differences of FC remained significant after controlling for cognitive measures. (3) Although sex \\documentclass{aastex}\\usepackage{amsbsy}\\usepackage{amsfonts}\\usepackage{amssymb}\\usepackage{bm}\\usepackage{mathrsfs}\\usepackage{pifont}\\usepackage{stmaryrd}\\usepackage{textcomp}\\usepackage{portland, xspace}\\usepackage{amsmath, amsxtra}\\pagestyle{empty}\\DeclareMathSizes{10}{9}{7}{6}\\begin{document} $$\\times

  15. Effects of age and sex on neuromuscular-mechanical determinants of muscle strength.

    PubMed

    Wu, Rui; Delahunt, Eamonn; Ditroilo, Massimiliano; Lowery, Madeleine; De Vito, Giuseppe

    2016-06-01

    The aim of this study was to concurrently assess the effect of age on neuromuscular and mechanical properties in 24 young (23.6 ± 3.7 years) and 20 older (66.5 ± 3.8 years) healthy males and females. Maximal strength of knee extensors (KE) and flexors (KF), contractile rate of torque development (RTD) and neural activation of agonist-antagonist muscles (surface EMG) were examined during maximal voluntary isometric contraction (MVIC). Tissue stiffness (i.e. musculo-articular stiffness (MAS) and muscle stiffness (MS)) was examined via the free-oscillation technique, whereas muscle architecture (MA) of the vastus lateralis and subcutaneous fat were measured by ultrasonography. Males exhibited a greater age-related decline for KE (47.4 %) and KF (53.1 %) MVIC, and RTD (60.4 %) when compared to females (32.9, 42.6 and 34.0 %, respectively). Neural activation of agonist muscles during KE MVIC falls markedly with ageing; however, no age and sex effects were observed in the antagonist co-activation. MAS and MS were lower in elderly compared with young participants and in females compared with males. Regarding MA, main effects for age (young 23.0 ± 3.3 vs older 19.5 ± 2.0 mm) and sex (males 22.4 ± 3.5 vs females 20.4 ± 2.7 mm) were detected in muscle thickness. For fascicle length, there was an effect of age (young 104.6 ± 8.8 vs older 89.8 ± 10.5 mm), while for pennation angle, there was an effect of sex (males 13.3 ± 2.4 vs females 11.5 ± 1.7°). These findings suggest that both neuromuscular and mechanical declines are important contributors to the age-related loss of muscle strength/function but with some peculiar sex-related differences.

  16. Synaptic strength and postsynaptically silent synapses through advanced aging in rat hippocampal CA1 pyramidal neurons

    PubMed Central

    Sametsky, Evgeny A.; Disterhoft, John F.; Geinisman, Yuri; Nicholson, Daniel A.

    2009-01-01

    Synaptic dysfunction is thought to contribute to age-related learning impairments. Detailed information regarding the presence of silent synapses and the strength of functional ones through advanced aging, however, is lacking. Here we used paired-pulse minimal stimulation techniques in CA1 stratum radiatum to determine whether the amplitude of spontaneous and evoked miniature excitatory postsynaptic currents (sEPSCs and eEPSCs, respectively) changes over the lifespan of rats in hippocampal CA1 pyramidal neurons, and whether silent synapses are present in adult and aged rats. The amplitudes of both sEPSCs and eEPSCs at resting membrane potential (i.e., clamped at −65 mV) initially increased between 2 weeks and 3 months, but then remained constant through 36 months of age. The potency of the eEPSCs at depolarized membrane potentials (i.e., clamped at +40 mV), however, was highest among 36-month old rats. Additionally, presynaptically silent synapses in CA1 stratum radiatum disappeared between 2 weeks and 3 months, but postsynaptically silent synapses were present through advanced aging. The similarity of silent and functional synapses in CA1 hippocampus at resting membrane potentials throughout adulthood in rats may indicate that impairments in the mechanisms of synaptic plasticity and its subsequent stabilization, rather than deficient synaptic transmission, underlie age-related cognitive decline. Such a notion is consistent with the increased amplitude of synaptic currents at depolarized potentials, perhaps suggesting an upregulation in the expression of synaptic NMDA receptors once rats reach advanced age. PMID:18620783

  17. Early stage of crack extension in impact loaded high strength steels

    SciTech Connect

    Giovanola, J.H.

    1995-12-31

    Measuring accurate dynamic initiation fracture toughness values requires the understanding of the early stage of crack extension to interpret experimental records and determine the initiation point correctly. The early stage of dynamic crack extension in high strength steels was investigated by impacting fatigue-precracked specimens of R{sub C} 50 AISI 4340 and 300M steel in a range of sizes using the one-point-bend test method. By controlling load amplitude (by varying the impact velocity) and load duration (by varying the specimen geometry and dimensions), we were able to control dynamic crack extension to achieve complete fracture of the specimen, or crack arrest after a few tenths of millimeter to several millimeters of propagation. Crack speeds in these experiments did not exceed a few hundred meters per second. A two-dimensional analysis of the experimental results show that the resistance to dynamic crack extension in terms of the stress intensity factor K, increases substantially (30-50% above the value at initiation) during the first millimeters of propagation and that this increase is not directly dependent on crack velocity. Fractographic observations of arrested cracks reveal that even when only small shear lips developed during fracture, the crack front shape is significantly curved, with the front at the center of the specimen leading the front at the surfaces by several millimeters. The good correlation between the distance over which the propagation toughness increases and the depth of the curved crack front suggests that the rise in toughness is associated with the development of the curved Crack front. This study demonstrates that three-dimensional effects are important in dynamic fracture of even such model materials as macroscopically brittle high strength steels. These effects should be carefully considered when analyzing fracture under short duration impulsive loads or interpreting initiation data.

  18. Early ERPs to faces: aging, luminance, and individual differences

    PubMed Central

    Bieniek, Magdalena M.; Frei, Luisa S.; Rousselet, Guillaume A.

    2013-01-01

    Recently, Rousselet et al. reported a 1 ms/year delay in visual processing speed in a sample of healthy aged 62 subjects (Frontiers in Psychology 2010, 1:19). Here, we replicate this finding in an independent sample of 59 subjects and investigate the contribution of optical factors (pupil size and luminance) to the age-related slowdown and to individual differences in visual processing speed. We conducted two experiments. In experiment 1 we recorded EEG from subjects aged 18–79. Subjects viewed images of faces and phase scrambled noise textures under nine luminance conditions, ranging from 0.59 to 60.8 cd/m2. We manipulated luminance using neutral density filters. In experiment 2, 10 young subjects (age < 35) viewed similar stimuli through pinholes ranging from 1 to 5 mm. In both experiments, subjects were tested twice. We found a 1 ms/year slowdown in visual processing that was independent of luminance. Aging effects became visible around 125 ms post-stimulus and did not affect the onsets of the face-texture ERP differences. Furthermore, luminance modulated the entire ERP time-course from 60 to 500 ms. Luminance effects peaked in the N170 time window and were independent of age. Importantly, senile miosis and individual differences in pupil size did not account for aging differences and inter-subject variability in processing speed. The pinhole manipulation also failed to match the ERPs of old subjects to those of young subjects. Overall, our results strongly suggest that early ERPs to faces (<200 ms) are delayed by aging and that these delays are of cortical, rather than optical origin. Our results also demonstrate that even late ERPs to faces are modulated by low-level factors. PMID:23717297

  19. Ageing influence in the evolution of strength and muscle mass in women with fibromyalgia: the al-Ándalus project.

    PubMed

    Latorre-Román, Pedro Ángel; Segura-Jiménez, Víctor; Aparicio, Virginia A; Santos E Campos, María Aparecida; García-Pinillos, Felipe; Herrador-Colmenero, Manuel; Álvarez-Gallardo, Inmaculada C; Delgado-Fernández, Manuel

    2015-07-01

    Fibromyalgia is associated with physical disabilities in daily activities. Moreover, patients with fibromyalgia present similar levels of functional capacity and physical condition than elderly people. The aim of this study was to analyse the evolution of strength and muscle mass in women with fibromyalgia along ageing. A total sample of 492 fibromyalgia patients and 279 healthy control women were included in the study. Participants in each group were further divided into four age subgroups: subgroup 1: 30-39 years old, subgroup 2: 40-49 years old, subgroup 3: 50-59 years old and subgroup 4: 60-69 years old. Standardized field-based fitness tests were used to assess muscle strength (30-s chair stand, handgrip strength and arm curl tests). Fibromyalgia patients did not show impairment on muscle mass along ageing, without values of skeletal muscle mass index below 6.76 kg/m(2) in any group. However, in all variables of muscle strength, the fibromyalgia group showed less strength than the healthy group (p < 0.05) for all age groups. As expected, handgrip strength test showed differences along ageing only in the fibromyalgia group (p < 0.001). Age was inversely associated with skeletal muscle mass (r = -0.155, p < 0.01) and handgrip strength (r = -0.230, p < 0.001) in the FM group. Women with fibromyalgia showed a reduction in muscle strength along ageing process, with significantly lower scores than healthy women for each age group, representing a risk of dynapenia.

  20. The Association of Levels of and Decline in Grip Strength in Old Age with Trajectories of Life Course Occupational Position

    PubMed Central

    Fritzell, Johan; Hoffmann, Rasmus

    2016-01-01

    Background The study of the influence of life course occupational position (OP) on health in old age demands analysis of time patterns in both OP and health. We study associations between life course time patterns of OP and decline in grip strength in old age. Methods We analyze 5 waves from the Survey of Health Ageing and Retirement in Europe (n = 5108, ages 65–90). We use a pattern-mixture latent growth model to predict the level and decline in grip strength in old age by trajectory of life course OP. We extend and generalize the structured regression approach to establish the explanatory power of different life course models for both the level and decline of grip strength. Results Grip strength declined linearly by 0.70 kg (95% CI -0.74;-0.66) for men and 0.42 kg (95% CI -0.45;-0.39) for women per year. The level of men’s grip strength can best be explained by a critical period during midlife, with those exposed to low OP during this period having 1.67 kg (95% CI -2.33;-1.00) less grip strength. These differences remain constant over age. For women, no association between OP and levels of or decline in grip strength was found. Conclusions Men’s OP in midlife seems to be a critical period for the level of grip strength in old age. Inequalities remain constant over age. The integration of the structured regression approach and latent growth modelling offers new possibilities for life course epidemiology. PMID:27232696

  1. Influence of aging treatments on microtensile bond strength of adhesive systems to primary dentin.

    PubMed

    Rocha, Rachel; Soares, Fabio Z M; Rodrigues, Celia R M D; Rodrigues Filho, Leonardo Eloy

    2007-01-01

    The purpose of this study was to evaluate the in vitro influence of aging treatments on the microtensile bond strength of 2-step total-etch and self-etch adhesive systems to primary dentin. Class I cavities (4 mm x 4 mm x 2 mm) were prepared in 80 extracted human primary molars divided into 8 groups (N=5) per adhesive system: (1) Single Bond (SI); and (2) Clearfil SE Bond (SE). Restored teeth were exposed to individual and combined aging treatments: (1) thermal (2,000 x at 5-55 degrees C; T); (2) mechanical load (100,000 x 80 N; M); (3) pH (mineralizing/demineralizing solutions; pH); and (4) control (24-hour water storage; C). Beam-shaped microtensile specimens were prepared (0.8 mm2 cross-sectional area) and loaded at a crosshead speed of 1.0 mm/minute in a universal testing machine. Fracture modes were examined by scanning electron microscope. Means (MPa) and standard deviations (+/-) were: (1) SI-T=24.17 (+/-1.99); (2) SI-M=25.64 (+/-9.75); (3) Si-pH=23.43 (+/-4.19); (4) SI-C=33.81 (+/-2.45); (5) SI-TM=18.60 (+/-3.57); (6) SI-TpH=23.90 (+/-4.28); (7) SI-MpH=20.96 (+/-4.06); (8) SI-TMpH=20.94 (+/-3.15); (9) SE-T=24.08 (+/-4.52); (10) SE-M=18.30 (+/-14.12); (11) SE-pH=19.22 (+/-8.93); (12) SE-C=37.80 (+/-7.28); (13) SE-TM=22.89 (+/-11.74); (14) SE-TpH=27.87 (+/-12.77); (15) SE-MpH=18.87 (+/-10.95); and (16) SE-TMpH=22.55 (+/-3.05). Both adhesive systems presented similar dentin bond strength (P>.05) which were significantly reduced when combined aging treatments were applied or when pH cycling (pH) was done. Combined aging treatments and also pH cycling alone influenced negatively adhesive bond strengths.

  2. Long-Term Isothermal Aging Effects on Carbon Fabric-Reinforced PMR-15 Composites: Compression Strength

    NASA Technical Reports Server (NTRS)

    Bowles, Kenneth J.; Roberts, Gary D.; Kamvouris, John E.

    1996-01-01

    A study was conducted to determine the effects of long-term isothermal thermo-oxidative aging on the compressive properties of T-650-35 fabric reinforced PMR-15 composites. The temperatures that were studied were 204, 260, 288, 316, and 343 C. Specimens of different geometries were evaluated. Cut edge-to-surface ratios of 0.03 to 0.89 were fabricated and aged. Aging times extended to a period in excess of 15,000 hours for the lower temperature runs. The unaged and aged specimens were tested in compression in accordance with ASTM D-695. Both thin and thick (plasma) specimens were tested. Three specimens were tested at each time/temperature/geometry condition. The failure modes appeared to be initiated by fiber kinking with longitudinal, interlaminar splitting. In general, it appears that the thermo-oxidative degradation of the compression strength of the composite material may occur by both thermal (time-dependent) and oxidative (weight-loss) mechanisms. Both mechanisms appear to be specimen-thickness dependent.

  3. Live strong and prosper: the importance of skeletal muscle strength for healthy ageing.

    PubMed

    McLeod, Michael; Breen, Leigh; Hamilton, D Lee; Philp, Andrew

    2016-06-01

    Due to improved health care, diet and infrastructure in developed countries, since 1840 life expectancy has increased by approximately 2 years per decade. Accordingly, by 2050, a quarter of Europe's population will be over 65 years, representing a 10 % rise in half a century. With this rapid rise comes an increased prevalence of diseases of ageing and associated healthcare expenditure. To address the health consequences of global ageing, research in model systems (worms, flies and mice) has indicated that reducing the rate of organ growth, via reductions in protein synthetic rates, has multi-organ health benefits that collectively lead to improvements in lifespan. In contrast, human pre-clinical, clinical and large cohort prospective studies demonstrate that ageing leads to anabolic (i.e. growth) impairments in skeletal muscle, which in turn leads to reductions in muscle mass and strength, factors directly associated with mortality rates in the elderly. As such, increasing muscle protein synthesis via exercise or protein-based nutrition maintains a strong, healthy muscle mass, which in turn leads to improved health, independence and functionality. The aim of this review is to critique current literature relating to the maintenance of muscle mass across lifespan and discuss whether maintaining or reducing protein synthesis is the most logical approach to support musculoskeletal function and by extension healthy human ageing.

  4. Emphysema, Airflow Limitation and Early Age-Related Macular Degeneration

    PubMed Central

    Klein, Ronald; Knudtson, Michael D.; Klein, Barbara E. K.; Wong, Tien Y.; Cotch, Mary Frances; Barr, R. Graham

    2009-01-01

    Objective To describe the relationships of lung function and emphysema, measured with spirometry and computed tomography (CT) scan, to early AMD in a multi-ethnic sample of whites, blacks, Hispanics, and Chinese. Methods and Design 3,399 persons aged 45–84 years residing in six United States communities participating in a period cross-sectional study. AMD was measured from digital retinal photographs at the second Multi-Ethnic Study of Atherosclerosis (MESA) examination. Forced expiratory volume in one second (FEV1) and FEV1/forced vital capacity (FVC) ratio were measured at the third or fourth MESA examination. Percent emphysema was measured from cardiac CT scans at baseline. Apical and basilar lung segments were defined as the cephalad or caudal regions of the lung on the cardiac CT scan. Logistic regression models were used to examine the relationship of lung function and structure to AMD controlling for age, gender, and other factors. Results The prevalence of early AMD was 3.7%. Early AMD was not associated with FEV1 (odds ratio [OR], 95% confidence interval [CI], and P value, 0.82, 0.58–1.15, P=0.25), FEV1/ FVC ratio (0.92, 0.76–1.12, 0.43), percent emphysema (1.13, 0.91–1.40, 0.26) and apical-basilar difference in percent emphysema (1.14, 0.95–1.37, 0.17). Associations were stronger in smokers. Apical-basilar difference in percent emphysema was significantly associated with early AMD among ever smokers (1.28, 1.02–1.60, 0.03). Associations were not modified by race/ethnicity. Conclusions Lung function and emphysema on CT scan were not cross-sectionally associated with AMD; this might be explained by the relatively low smoking exposure in this cohort. PMID:20385944

  5. Residual interface tensile strength of ceramic bonded to dentin after cyclic loading and aging.

    PubMed

    Hernandez, Alfredo I; Roongruangphol, Thasanai; Katsube, Noriko; Seghi, Robert R

    2008-03-01

    To guard against the potential risk of cusp fracture, esthetic onlay restorations have been advocated for teeth with large restorations. The influence of the adhesive resin cement is believed to play a role in strengthening these restorations. The durability of this tooth/adhesive/ceramic interface is critical to ensure clinical longevity. The purpose of this study was to assess the effects of cyclic loading and environmental aging on the residual interface strength of a ceramic bonded to dentin structure. Eighteen simple trilayer specimens were fabricated, consisting of a 1.5-mm-thick ceramic plate (ProCAD) bonded to a flattened human molar tooth with exposed coronal dentin. The ceramic plates were bonded using resin cement (Nexus 2) and manufacturer-recommended bonding techniques. The specimens were divided into 3 equal groups and were stored in water at 37 degrees C for 10 weeks as a control group (CT), 9 months as an aging group (AG), or placed in water at 37 degrees C while being subjected to 10 million vertical loading cycles between 20 N to 200 N, as a fatigue group (FG). After the specimens were subjected to the experimental conditions, they were sectioned perpendicular to the flat ceramic surface into 1 x 1-mm sticks. The mean residual interface microtensile bond (MTB) strength was determined for each specimen using only those sticks which contained ceramic bonded to dentin. The MTB strength data were analyzed using Weibull analysis methods to determine differences between groups. All subsequent failed specimen surfaces were evaluated under a stereomicroscope at x10 magnification to determine the apparent failure modes. Some specimens were selected from each failure mode category for surface evaluation under a scanning electron microscope (SEM). The characteristic Weibull means for the 3 groups were CT, 19.2, FG, 14.7, and AG, 11.7. The bond strength of group CT was significantly greater than both AG (P=.007) and FG (P=.014). Light microscopic

  6. Low- or high-intensity strength training partially restores impaired quadriceps force accuracy and steadiness in aged adults.

    PubMed

    Hortobágyi, T; Tunnel, D; Moody, J; Beam, S; DeVita, P

    2001-01-01

    Because many daily tasks are executed at only a fraction of maximal strength, an understanding of submaximal force control may be important for improving function in aged adults. We compared the effects of low- and high-intensity (LI and HI, respectively) strength training on maximal and explosive strength and on the accuracy (force error) and steadiness (variability) of submaximal quadriceps force in elderly humans. Older subjects (age, 72 years; n = 27) had 57% lower maximal strength in comparison with young subjects (age, 21 years; n = 10). Older subjects had 190% (19 N), 50% (1 N), and 80% (4 N) more force error in matching 25 N of quadriceps force during eccentric, isometric, and concentric contractions, and had 157%, 0%, and 60% more variability in these forces compared with young subjects. Force error and force variability were correlated with each other but not with maximal strength. Thirty sessions of LI (n = 9 participants) or HI (n = 9 participants) training of equal total work increased maximal strength in the older subjects by 29%. Training also significantly reduced force error and variability--by 31% and 30%, respectively--of eccentric and concentric contractions. A control group of older subjects (n = 9) showed no significant changes in any variables. LI or HI strength training was equally effective in partially restoring elderly adults' maximal strength and control of submaximal force.

  7. Early Television Exposure and Children’s Behavioral and Social Outcomes at Age 30 Months

    PubMed Central

    Cheng, Shunyue; Maeda, Tadahiko; Yoichi, Sakakihara; Yamagata, Zentaro; Tomiwa, Kiyotaka

    2010-01-01

    Background Previous research has suggested that television (TV) viewing may be associated with increased behavioral and emotional problems in children. However, there are few prospective studies targeted for its association with outcomes of children under 3 years old. The purpose of this study was to exam the association between children’s early TV exposure at ages 18 and 30 months and the behavioral and emotional outcomes at age 30 months. Methods We analyzed data collected prospectively in the Japan Children’s Study. TV exposure was assessed by mothers’ report at infant ages of 18 and 30 months. The outcomes were assessed using the Strengths and Difficulties Questionnaire (SDQ). Analysis of Covariance was used to estimate the effect of TV exposure on behavioral and emotional outcomes. Results The percentage of children who watched TV 4 hours or more per day was 29.4% at age 18 months, 24.5% at age 30 months, and 21% at both ages. Hyperactivity–inattention at age 30 months was positively associated with TV exposure at age 18 months, whereas prosocial behavior was negatively associated with hours of exposure even after adjustment. However, there were no significant differences in SDQ subscales according to daily hours of TV viewing at age 30 months. Conclusions Daily TV exposure at age 18 months was associated with hyperactivity–inattention and prosocial behavior at age 30 months. However, the directly casual relation was not proved in the present study. Additional research considering the TV program content and exposure timing are needed to investigate the causal relation between TV viewing and behavioral outcome. PMID:20179364

  8. Early twentieth-century warming linked to tropical Pacific wind strength

    NASA Astrophysics Data System (ADS)

    Thompson, Diane M.; Cole, Julia E.; Shen, Glen T.; Tudhope, Alexander W.; Meehl, Gerald A.

    2015-02-01

    Of the rise in global atmospheric temperature over the past century, nearly 30% occurred between 1910 and 1940 when anthropogenic forcings were relatively weak. This early warming has been attributed to internal factors, such as natural climate variability in the Atlantic region, and external factors, such as solar variability and greenhouse gas emissions. However, the warming is too large to be explained by external factors alone and it precedes Atlantic warming by over a decade. For the late twentieth century, observations and climate model simulations suggest that Pacific trade winds can modulate global temperatures, but instrumental data are scarce in the early twentieth century. Here we present a westerly wind reconstruction (1894-1982) from seasonally resolved measurements of Mn/Ca ratios in a western Pacific coral that tracks interannual to multidecadal Pacific climate variability. We then reconstruct central Pacific temperatures using Sr/Ca ratios in a coral from Jarvis Island, and find that weak trade winds and warm temperatures coincide with rapid global warming from 1910 to 1940. In contrast, winds are stronger and temperatures cooler between 1940 and 1970, when global temperature rise slowed down. We suggest that variations in Pacific wind strength at decadal timescales significantly influence the rate of surface air temperature change.

  9. Association between floating toe and toe grip strength in school age children: a cross-sectional study

    PubMed Central

    Tasaka, Seishiro; Matsubara, Keisuke; Nishiguchi, Shu; Fukutani, Naoto; Tashiro, Yuto; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Matsushita, Tomofumi; Fukumoto, Takahiko; Aoyama, Tomoki

    2016-01-01

    [Purpose] This study investigated the association between floating toe and toe grip strength. [Subjects and Methods] A total of 635 Japanese children aged 9–11 years participated in this study. Floating toe was evaluated using footprint images, while toe grip strength was measured using a toe grip dynamometer. All 1,270 feet were classified into a floating toe group and a normal toe group according to visual evaluation of the footprint images. Intergroup differences in toe grip strength were analyzed using the unpaired t-test and logistic regression analysis adjusted for age, gender, and Rohrer Index. [Results] There were 512 feet (40.3%) in the floating toe group. Mean toe grip strength of the feet with floating toe was significantly lower than that of normal feet (floating toe group, 12.9 ± 3.7 kg; normal toe group, 13.6 ± 4.1 kg). In addition, lower toe grip strength was associated with floating toe on logistic regression analysis after adjustment for age, gender, and Rohrer Index (odds ratio, 0.954; 95% confidence interval, 0.925–0.984). [Conclusion] This study revealed that lower toe grip strength was significantly associated with floating toe. Therefore, increasing toe grip strength may play a role in preventing floating toe in school age children. PMID:27630423

  10. Association between floating toe and toe grip strength in school age children: a cross-sectional study.

    PubMed

    Tasaka, Seishiro; Matsubara, Keisuke; Nishiguchi, Shu; Fukutani, Naoto; Tashiro, Yuto; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Matsushita, Tomofumi; Fukumoto, Takahiko; Aoyama, Tomoki

    2016-08-01

    [Purpose] This study investigated the association between floating toe and toe grip strength. [Subjects and Methods] A total of 635 Japanese children aged 9-11 years participated in this study. Floating toe was evaluated using footprint images, while toe grip strength was measured using a toe grip dynamometer. All 1,270 feet were classified into a floating toe group and a normal toe group according to visual evaluation of the footprint images. Intergroup differences in toe grip strength were analyzed using the unpaired t-test and logistic regression analysis adjusted for age, gender, and Rohrer Index. [Results] There were 512 feet (40.3%) in the floating toe group. Mean toe grip strength of the feet with floating toe was significantly lower than that of normal feet (floating toe group, 12.9 ± 3.7 kg; normal toe group, 13.6 ± 4.1 kg). In addition, lower toe grip strength was associated with floating toe on logistic regression analysis after adjustment for age, gender, and Rohrer Index (odds ratio, 0.954; 95% confidence interval, 0.925-0.984). [Conclusion] This study revealed that lower toe grip strength was significantly associated with floating toe. Therefore, increasing toe grip strength may play a role in preventing floating toe in school age children.

  11. The effect of a complex training and detraining programme on selected strength and power variables in early pubertal boys.

    PubMed

    Ingle, Lee; Sleap, Mike; Tolfrey, Keith

    2006-09-01

    Complex training, a combination of resistance training and plyometrics is growing in popularity, despite limited support for its efficacy. In pre- and early pubertal children, the study of complex training has been limited, and to our knowledge an examination of its effect on anaerobic performance characteristics of the upper and lower body has not been undertaken. Furthermore, the effect of detraining after complex training requires clarification. The physical characteristics (mean+/-s) of the 54 male participants in the present study were as follows: age 12.3 +/- 0.3 years, height 1.57 +/- 0.07 m, body mass 50.3 +/- 11.0 kg. Participants were randomly assigned to an experimental (n = 33) or control group (n = 21). The training, which was performed three times a week for 12 weeks, included a combination of dynamic constant external resistance and plyometrics. After training, participants completed 12 weeks of detraining. At baseline, after training and after detraining, peak and mean anaerobic power, dynamic strength and athletic performance were assessed. Twenty-six participants completed the training and none reported any training-related injury. Complex training was associated with small increases (< or =5.5%) in peak and mean power during training, followed by decreases of a similar magnitude (< or = -5.9%) during detraining (P < 0.05). No changes or minor, progressive increases (< or =1.5%) were evident in the control group (P > 0.05). In the experimental group, dynamic strength was increased by 24.3 - 71.4% (dependent on muscle group; P < 0.01), whereas growth-related changes in the control group varied from 0 to 4.4% (P > 0.05). For 40-m sprint running, basketball chest pass and vertical jump test performance, the experimental group saw a small improvement (< or =4.0%) after training followed by a decline (< or = -4.4%) towards baseline during detraining (P < 0.05), whereas the control group experienced no change (P > 0.05). In conclusion, in pre- and early

  12. Effects of Dry-Land Strength and Conditioning Programs in Age Group Swimmers.

    PubMed

    Amaro, Nuno M; Marinho, Daniel A; Marques, Mário C; Batalha, Nuno P; Morouço, Pedro G

    2017-09-01

    Amaro, NM, Marinho, DA, Marques, MC, Batalha, N, and Morouço, PG. Effects of dry-land strength and conditioning programs in age group swimmers. J Strength Cond Res 31(9): 2447-2454, 2017-Even though dry-land S&C training is a common practice in the context of swimming, there are countless uncertainties over its effects in performance of age group swimmers. The objective was to investigate the effects of dry-land S&C programs in swimming performance of age group swimmers. A total of 21 male competitive swimmers (12.7 ± 0.7 years) were randomly assigned to the Control group (n = 7) and experimental groups GR1 and GR2 (n = 7 for each group). Control group performed a 10-week training period of swim training alone, GR1 followed a 6-week dry-land S&C program based on sets and repetitions plus a 4-week swim training program alone and GR2 followed a 6-week dry-land S&C program focused on explosiveness, plus a 4-week program of swim training alone. Results for the dry-land tests showed a time effect between week 0 and week 6 for vertical jump (p < 0.01) in both experimental groups, and for the GR2 ball throwing (p < 0.01), with moderate to strong effect sizes. The time × group analyses showed that for performance in 50 m, differences were significant, with the GR2 presenting higher improvements than their counterparts (F = 4.156; p = 0.007; (Equation is included in full-text article.)= 0.316) at week 10. Concluding, the results suggest that 6 weeks of a complementary dry-land S&C training may lead to improvements in dry-land strength. Furthermore, a 4-week adaptation period was mandatory to achieve beneficial transfer for aquatic performance. Additional benefits may occur if coaches plan the dry-land S&C training focusing on explosiveness.

  13. Effect of surface treatment and aging on bond strength of composite resin onlays.

    PubMed

    Cura, Maria; González-González, Inmaculada; Fuentes, Victoria; Ceballos, Laura

    2016-09-01

    Additional polymerization of indirect composite resins enhances their physical properties but lessens the potential for chemical bonding. The purpose of this in vitro study was to evaluate the influence of different surface treatments and 6-month water storage on the microtensile bond strength (μTBS) of composite resin onlays. Composite resin onlays (Filtek Z250) randomly received 6 different surface treatments: (1) airborne-particle abrasion with 27-μm alumina particles+Adper Scotchbond 1XT adhesive application, (2) airborne-particle abrasion with alumina particles+silane application (ESPE SIL)+Adper Scotchbond 1XT, (3) airborne-particle abrasion with alumina particles+Scotchbond Universal adhesive, (4) tribochemical silica coating with 30-μm particles (CoJet Sand)+Adper Scotchbond 1XT adhesive, (5) tribochemical silica coating+silane application+Adper Scotchbond 1XT, and (6) tribochemical silica coating+Scotchbond Universal adhesive. Onlays were luted to fresh composite resin specimens with RelyX Ultimate resin cement. Bonded assemblies were stored in water for 24 hours or 6 months at 37°C and subjected to the μTBS test. Additional surface-treated composite resin onlays were analyzed with a contact profilometer to determine average roughness, and micromorphologic changes were analyzed with scanning electron microscopy. Airborne-particle abrasion with alumina followed by Adper Scotchbond 1XT or Scotchbond Universal adhesive application provided the highest bond strength values at 24 hours. Lower values were obtained after tribochemical silica coating. After 6 months of artificial aging, airborne-particle abrasion with alumina or silica-coated alumina particles followed by Scotchbond Universal application yielded the greatest bond strength results. Airborne-particle abrasion with alumina produced the highest roughness values and a more irregular surface. Adhesive selection seems to be relevant to the μTBS of luted composite resin onlays after 6 months of

  14. Early age performance of latex-modified concrete bridge deck overlays

    NASA Astrophysics Data System (ADS)

    Sujjavanich, Suvimol

    Environmental factors and physical properties of latex modified concrete (LMC) are hypothesized to contribute to early age cracking in bridge deck overlays. Cracking permits the ingress of moisture and aggressive solutions into the substrate and may contribute to other subsequent distresses. Understanding the material properties and mechanisms involved is necessary to minimize these distresses. This research consisted of a two part study: first, the development of LMC strength and fracture properties at ages ranging from 5 hours to 28 days was studied, and secondly, the effects of the environment on LMC distresses were modelled. Environmental conditions: temperature, solar energy, and wind speed were determined from weather records. A fracture mechanics based model, the Fictitious Crack Model (FCM), incorporating finite element analyses and superposition techniques was employed with material properties from the first part of study on LMC performance. Different bilinear strain softening diagrams were used to predict fracture performance at different ages. The predictions agreed well with the test data. The impacts of temperature differentials on crack development were studied. The shrinkage effect was also indirectly incorporated through the temperature analysis. The material properties study indicated significant changes in strength, deformability and fracture properties, particularly during the early age. The developments differ slightly from conventional concrete. Test results indicated a significant improvement in reducing and bridging microcracks, especially in the prepeak-load region. Fracture toughness and deformability increased significantly with time. Fracture energy varied from 2.3 to 133.1 N/m, depending on age, and to some degree, on notch depth ratio. In the second stage, the FCM provided a reasonable prediction for crack initiation and propagation when only temperature effects are of concern. Age, surface conditions and structural restraint strongly

  15. Effects of strength, endurance and combined training on muscle strength, walking speed and dynamic balance in aging men.

    PubMed

    Holviala, J; Kraemer, W J; Sillanpää, E; Karppinen, H; Avela, J; Kauhanen, A; Häkkinen, A; Häkkinen, K

    2012-04-01

    The aim of this study was to examine effects of 21-week twice weekly strength (ST), endurance (ET) and combined (ST + ET 2 + 2 times a week) (SET) training on neuromuscular, endurance and walking performances as well as balance. 108 healthy men (56.3 ± 9.9 years) were divided into three training (ST; n = 30, ET; n = 26, SET; n = 31) groups and controls (C n = 21). Dynamic 1RM and explosive leg presses (1RMleg, 50%1RMleg), peak oxygen uptake using a bicycle ergometer (VO(2peak)), 10 m loaded walking time (10WALK) and dynamic balance distance (DYND) were measured. Significant increases were observed in maximal 1RMleg of 21% in ST (p < 0.001) and 22% in SET (p < 0.001) and in explosive 50%1RMleg of 7.5% in ST (p = 0.005) and 10.2% in SET (p < 0.001). VO(2peak) increased by 12.5% in ET (p = 0.001) and 9.8% in SET (p < 0.001). Significant decreases occurred in 10WALK in ST (p < 0.001) and SET (p = 0.003) and also in DYND of -10.3% in ST (p = 0.002) and -8% in SET (p = 0.028). The changes in C remained minor in all variables. In conclusion, ST and SET training produced significant improvements in maximal and explosive strength, walking speed and balance without any interference effect in SET. Significant but moderate relationships were observed between strength and dynamic balance and walking speed, while no corresponding correlations were found in the ET group.

  16. Cross-education of strength and skill: an old idea with applications in the aging nervous system

    PubMed Central

    Barss, Trevor S.; Pearcey, Gregory E.P.; Zehr, E. Paul

    2016-01-01

    Edward Wheeler Scripture’s 1894 work out of the Yale Psychological Laboratory has been influential in identifying the nervous system’s contribution to the bilateral improvements that are seen with unilateral strength and skill training. Scripture coined the term “cross-education” to describe this improvement in the untrained contralateral limb. While physiological changes accompany aging that may negatively affect the performance of physical tasks, far too much credit has been given to the natural aging process rather than the effects of inactivity. Emerging evidence indicates strength or skill training interventions induce significant neuroplasticity in an aging population. The model of unilateral training provides a unique approach in which to elicit such plasticity. This brief review highlights the innate ability of the nervous system to adapt to unilateral strength and skill training interventions, regardless of age, and provides a novel perspective on the robust plastic ability of the aging nervous system. PMID:27505019

  17. Pubertal timing and bone phenotype in early old age: findings from a British birth cohort study

    PubMed Central

    Kuh, Diana; Muthuri, Stella G; Moore, Adam; Cole, Tim J; Adams, Judith E; Cooper, Cyrus; Hardy, Rebecca; Ward, Kate A

    2016-01-01

    Objectives To investigate the effect of pubertal timing, assessed in adolescence, on bone size, strength and density in men and women in early old age Design A British birth cohort study with prospective indicators of pubertal timing based on age at menarche, clinical assessment of pubertal stage, and growth tempo from serial height measures, and bone measures derived from peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) at 60-64 years on 866 women and 792 men. Methods A first set of regression models investigated the relationships between pubertal timing and bone size, strength and density, adjusting for current height and weight, smoking and adult socioeconomic position. To make an equivalent comparison between men and women, the percentage difference in bone outcomes was calculated for a five-year difference in age at menarche, and in men a comparison between those who were fully mature or pre-adolescent at 14.5 years. A second set of models investigated the percentage difference in bone outcomes for a 5-year difference in timing of peak height velocity (height tempo) derived from longitudinal growth modelling (SITAR). Results After adjustment for current height and weight, a 5-year increase in age at menarche was associated with an 8% (95% CI -17%, 0.5%, p=0.07) lower trabecular volumetric bone mineral density (vBMD); men who were pre-adolescent at 14.5 years had a 9%, (95%CI -14%,-4%; p=.001) lower trabecular vBMD compared with those who had been fully mature. Other confounders did not attenuate these estimates further. Patterns of association were similar but somewhat weaker for lumbar spine and total hip areal BMD. Age at peak height velocity was associated with even larger differences in BMD in men and women, and was negatively associated with bone size and strength. Conclusions The association between later puberty and lower BMD persists into early old age. The 9-10% lower trabecular vBMD in later compared with

  18. Nutrition in early life and age-associated diseases.

    PubMed

    Tarry-Adkins, Jane L; Ozanne, Susan E

    2017-10-01

    The prevalence of age-associated disease is increasing at a striking rate globally. It is known that a strong association exists between a suboptimal maternal and/or early-life environment and increased propensity of developing age-associated disease, including cardiovascular disease (CVD), type-2 diabetes (T2D) and obesity. The dissection of underlying molecular mechanisms to explain this phenomenon, which is known as 'developmental programming' is still emerging; however three common mechanisms have emerged in many models of developmental programming. These mechanisms are (a) changes in tissue structure, (b) epigenetic regulation and (c) accelerated cellular ageing. This review will examine the epidemiological evidence and the animal models of suboptimal maternal environments, focusing upon these molecular mechanisms and will discuss the progress being made in the development of safe and effective intervention strategies which ultimately could target those 'programmed' individuals who are known to be at-risk of age-associated disease. Copyright © 2016. Published by Elsevier B.V.

  19. The Relationship between Greater Pre-Pubertal Adiposity, Subsequent Age of Maturation and Bone Strength during Adolescence†

    PubMed Central

    Glass, Natalie A.; Torner, James C.; Letuchy, Elena M.; Burns, Trudy L.; Janz, Kathleen F.; Gilmore, Julie M. Eichenberger; Schlechte, Janet A.; Levy, Steven M.

    2016-01-01

    This longitudinal study investigated whether greater pre-pubertal adiposity was associated with subsequent timing of maturation and bone strength during adolescence in 135 girls and 123 boys participating in the Iowa Bone Development Study. Greater adiposity was defined using BMI data at age 8 years to classify participants as overweight (OW, ≥85th percentile for age and sex) or healthy-weight, HW). Maturation was defined as the estimated age of peak height velocity (PHV) based on a series of cross-sectional estimates. Measurements were taken at ages 11, 13, 15 and 17 years for estimates of body composition by DXA, bone compression (bone strength index) and torsion strength (polar strength-strain index) at the radius and tibia by pQCT, and femoral neck bending strength (section modulus) by hip structural analysis. Bone strength in OW versus HW were evaluated by fitting sex-specific linear mixed models that included centered age (visit age – grand mean age of cohort) as the time variable and adjusted for change in fat mass, and limb length in Model 1. Analyses were repeated using biological age (visit ageage PHV) as the time variable for Model 1 with additional adjustment for lean mass in Model 2. BMI was negatively associated with age of maturation (p<0.05). OW versus HW girls had significantly greater bone strength (p<0.001) in Model 1, while OW versus HW boys had significantly greater bone strength (p<0.001) at the tibia and femoral neck, but not radius (p>0.05). Analyses were repeated using biological age, which yielded reduced parameter estimates for girls but similar results for boys (Model 1.) Differences were no longer present following adjustment for lean mass (Model 2) in girls (p>0.05) while differences at the tibia were sustained in boys (p<0.05). These findings demonstrate sex- and site-specific differences in the associations between adiposity, maturation and bone strength. PMID:26861036

  20. The fragile elderly hip: Mechanisms associated with age-related loss of strength and toughness☆

    PubMed Central

    Reeve, Jonathan; Loveridge, Nigel

    2014-01-01

    Every hip fracture begins with a microscopic crack, which enlarges explosively over microseconds. Most hip fractures in the elderly occur on falling from standing height, usually sideways or backwards. The typically moderate level of trauma very rarely causes fracture in younger people. Here, this paradox is traced to the decline of multiple protective mechanisms at many length scales from nanometres to that of the whole femur. With normal ageing, the femoral neck asymmetrically and progressively loses bone tissue precisely where the cortex is already thinnest and is also compressed in a sideways fall. At the microscopic scale of the basic remodelling unit (BMU) that renews bone tissue, increased numbers of actively remodelling BMUs associated with the reduced mechanical loading in a typically inactive old age augments the numbers of mechanical flaws in the structure potentially capable of initiating cracking. Menopause and over-deep osteoclastic resorption are associated with incomplete BMU refilling leading to excessive porosity, cortical thinning and disconnection of trabeculae. In the femoral cortex, replacement of damaged bone or bone containing dead osteocytes is inefficient, impeding the homeostatic mechanisms that match strength to habitual mechanical usage. In consequence the participation of healthy osteocytes in crack-impeding mechanisms is impaired. Observational studies demonstrate that protective crack deflection in the elderly is reduced. At the most microscopic levels attention now centres on the role of tissue ageing, which may alter the relationship between mineral and matrix that optimises the inhibition of crack progression and on the role of osteocyte ageing and death that impedes tissue maintenance and repair. This review examines recent developments in the understanding of why the elderly hip becomes fragile. This growing understanding is suggesting novel testable approaches for reducing risk of hip fracture that might translate into control

  1. IMPACT OF BACK MUSCLE STRENGTH AND AGING ON LOCOMOTIVE SYNDROME IN COMMUNITY LIVING JAPANESE WOMEN

    PubMed Central

    HIRANO, KENICHI; IMAGAMA, SHIRO; HASEGAWA, YUKIHARU; WAKAO, NORIMITSU; MURAMOTO, AKIO; ISHIGURO, NAOKI

    2013-01-01

    ABSTRACT The Japanese Orthopaedic Association has proposed the term locomotive syndrome (LS) to designate a condition of individuals in high-risk groups with musculoskeletal disease who are highly likely to require nursing care. This study investigates the influence of spinal factors on LS in Japanese females. A total of 187 women >50 years old were enrolled in the study. Those answering yes to least one of the 7 categories in the self-assessment checklist for LS were defined as having LS. We evaluated lateral lumbar radiographs, sagittal parameters, sagittal balance using the spinal inclination angle (SIA) as an index, spinal range of motion (ROM) as determined with SpinalMouse®, back muscle strength (BMS), and body mass index (BMI). Age, BMI, BMS, SIA, sacral slope angle (SSA), and lumbar spinal ROM showed significant correlations with LS. Multiple logistic regression analysis indicated that an increase in age (OR 1.054, p<0.05) and a decrease in BMS (OR 0.968, p<0.01) were significantly associated with LS. Age had significant negative correlations with BMS, SSA, thoracic and lumbar spinal ROM, and it had positive correlations with BMI, SIA, and lumbar kyphosis. BMS had significant negative correlations with age, SIA, thoracic and lumbar kyphosis, and it had positive correlations with SSA, lumbar and total spinal ROM. An increase in age and a decrease in BMS may be the most important risk factors for LS in Japanese women. Back muscle strengthening and spinal ROM exercises could be useful for improving the status of an individual suffering from LS. PMID:23544268

  2. Increasing Age Is a Risk Factor for Decreased Postpartum Pelvic Floor Strength.

    PubMed

    Quiroz, Lieschen H; Pickett, Stephanie D; Peck, Jennifer D; Rostaminia, Ghazaleh; Stone, Daniel E; Shobeiri, S Abbas

    This study aimed to determine factors associated with decreased pelvic floor strength (PFS) after the first vaginal delivery (VD) in a cohort of low-risk women. This is a secondary analysis of a prospective study examining the risk of pelvic floor injury in a cohort of primiparous women. All recruited participants underwent an examination, three-dimensional ultrasound and measurement of PFS in the third trimester and repeated at 4 weeks to 6 months postpartum using a perineometer. There were 84 women recruited for the study, and 70 completed the postpartum assessment. Average age was 28.4 years (standard deviation, 4.8). There were 46 (66%) subjects with a VD and 24 (34%) with a cesarean delivery who labored. Decreased PFS was observed more frequently in the VD group compared with the cesarean delivery group (68% vs 42%, P = 0.03).In modified Poisson regression models controlling for mode of delivery and time of postpartum assessment, women who were aged 25 to 29 years (risk ratio = 2.80, 95% confidence interval, 1.03-7.57) and 30 years and older (risk ratio = 2.53, 95% confidence interval, 0.93-6.86) were over 2.5 times more likely to have decreased postpartum PFS compared with women younger than 25 years. In this population, women aged 25 years and older were more than twice as likely to have a decrease in postpartum PFS.

  3. Effect of ageing on isometric strength through joint range at knee and hip joints in three age groups of older adults.

    PubMed

    Samuel, Dinesh; Rowe, Philip J

    2009-01-01

    Strength of lower extremity muscles is an important determinant of mobility-based functional activities. Loss of strength with age produces functional limitation in activities of daily living such as rising from a chair or stair negotiation. However, there is limited information on the effect of age-related changes on the torque-producing ability of muscles through their ranges of joint motion. To investigate the effect of ageing on the torque-producing ability of lower extremity muscles in a large sample of older adults in three age groups. Eighty-two volunteers participated in this study and were divided into six groups according to their chronological age (60s, 70s and 80s and above) and gender (male, female). Isometric muscle strength was measured at the knee and hip joints at three positions through the joint range using a custom-built strain gauge torque dynamometer and a purpose built plinth. The peak torque of major muscle groups of the knee and hip joints decreased with increasing age at all the three joint positions at which strength was tested. The 80-year-olds had 20% lower strength compared to the 60-year-olds. Age-related decrease in muscle strength was significant when comparing 80-year-olds with the 60-year-olds (p < 0.05). Strength loss was noted to be higher at the inner (muscle is shortened from mid-position) and outer (muscle is lengthened from mid-position) ranges of muscle action when compared with the mid-range position (mid-position). Gender-based differences were significant for all the strength tests (p < 0.05). Strength decreased with increasing age at all the positions within joint range of motion for knee and hip joints. However, the percentage loss of muscle strength was different at different positions in the joint range. Our findings suggest that muscle strength was more preserved in the middle range of muscle function compared to the inner and outer range of muscle action. In older people, lower extremity muscles might be required

  4. Evaluation of pelvic floor muscle strength before and after robotic-assisted radical prostatectomy and early outcomes on urinary continence.

    PubMed

    Manley, Lauren; Gibson, Luke; Papa, Nathan; Beharry, Bhawanie Koonj; Johnson, Liana; Lawrentschuk, Nathan; Bolton, Damien M

    2016-12-01

    The aim of the study was to evaluate the effect of pelvic floor muscle (PFM) assessment and training before and after robot-assisted laparoscopic radical prostatectomy (RARP) in improving PFM strength and urinary continence. We performed an analysis of a database of patients who underwent robot-assisted laparoscopic radical prostatectomy (RARP) performed by two urologists from 2011 to 2013. Pelvic floor muscle (PFM) activation and strength were graded by a trained pelvic floor physiotherapist. Patients were given an exercise program, grouped according to the strength of their pelvic floor as graded by assessment, to complete before and after surgery. PFM strength was recorded preoperatively, 4 days post-catheter removal and 4 weeks post-catheter removal. Continence was recorded at 4 weeks postop and was defined as the requirement of no continence aids. A total of 98 patients had RARP and a preoperative physiotherapy assessment plus postoperative appointments at around 1 and 4 weeks post-RARP. The majority of men improved their PFM strength regardless of preoperative strength with no significant predictors of postoperative strength found. Age was the only significant predictor of postoperative incontinence. In this pilot study, a majority of patients increased their pelvic floor strength with time. Pelvic floor physiotherapy is an important modifiable patient factor, which does have an impact in improving patients' urinary continence by strengthening the pelvic floor muscles. Patient age influences response to pelvic floor physiotherapy.

  5. Later Age at Onset of Independent Walking Is Associated with Lower Bone Strength at Fracture-Prone Sites in Older Men.

    PubMed

    Ireland, Alex; Muthuri, Stella; Rittweger, Joern; Adams, Judith E; Ward, Kate A; Kuh, Diana; Cooper, Rachel

    2017-02-09

    Later age at onset of independent walking is associated with lower leg bone strength in childhood and adolescence. However it is unknown whether these associations persist into older age, or whether they are evident at axial (central) or upper limb sites. Therefore we examined walking age obtained at 2y and bone outcomes obtained by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) scans at 60-64y in a nationally-representative cohort study of British people, the MRC National Survey of Health and Development. It was hypothesised that later walking age would be associated with lower bone strength at all sites. Later independent walking age was associated with lower height-adjusted hip (standardised regression coefficients with 95%CI) [-0.179(-0.251,-0.107)], spine [-0.157(-0.232,-0.082)] and distal radius [-0.159(-0.245,-0.073)] bone mineral content (BMC, indicating bone compressive strength) in men (all P < 0.001). Adjustment for covariates partially attenuated these associations, primarily due to lower lean mass and adolescent sporting ability in later walkers. These associations were also evident for a number of hip geometric parameters (including cross-sectional moment of inertia (CSMI), indicating bone bending/torsional strength) assessed by Hip Structural Analysis (HSA) from DXA scans. Similar height-adjusted associations were also observed in women for several hip, spine and upper limb outcomes, although adjustment for fat or lean mass led to complete attenuation for most outcomes, with the exception of femoral shaft CSMI and spine bone area (BA). In conclusion, later independent walking age appears to have a lifelong association with bone strength across multiple skeletal sites in men. These effects may result from direct effects of early life loading on bone growth, and mediation by adult body composition. Results suggest that late walking age may represent a novel risk factor for subsequent low bone strength

  6. Nanomodification of Cementitious Materials: Fresh State and Early Age

    NASA Astrophysics Data System (ADS)

    Kawashima, Shiho

    Concrete is heterogeneous at all length scales and its microstructure evolves continuously over decades. Through the use of nanoparticles, it is possible to alter the microstructure of cementitious materials from within the first microsecond to control its rheological and eventual mechanical properties. The continued development of this technology hinges on adopting a materials science approach to achieve proper processing and measurement techniques, both of which are investigated in this study. Novel rheological methods are implemented to evaluate the fresh-state properties of cement pastes modified with nano-sized attapulgite clays. Previous studies have demonstrated that clays can reduce the lateral pressure exerted on formwork by self-consolidating concrete (SCC). It is hypothesized that this is tied to the influence of clays on two rheological properties of SCC: material cohesion and structural rebuilding. Therefore the effect of clays on adhesive properties is measured by the tack test and rate of rebuilding is evaluated by measuring relaxation time during creep. In addition, due to the complexity of cement rheology, i.e. simultaneous thixotropic rebuilding and hydration, the results are supplemented with a measure of the viscoelastic properties obtained through oscillatory shear rheometry. It is found that clays significantly increase cohesion and accelerate structural recovery of cement pastes. The results also indicate that the tack test is a suitable method for measuring the adhesive properties and structural evolution of cementitious materials in the fresh state. The potential of calcium carbonate (CaCO3) nanoparticles in improving the early-age properties of fly ash-cement pastes is investigated. The focus is on dispersing the CaCO3 nanoparticles to enhance their effect and limit the addition level necessary. The selected approach involves sonication in an aqueous medium and use of surfactant. Degree of dispersion and stability are quantitatively

  7. Decrease of muscle strength is associated with increase of activity limitations in early knee osteoarthritis: 3-year results from the cohort hip and cohort knee study.

    PubMed

    van der Esch, Martin; Holla, Jasmijn F; van der Leeden, Marike; Knol, Dirk L; Lems, Willem F; Roorda, Leo D; Dekker, Joost

    2014-10-01

    To determine whether a decrease in muscle strength over 3 years is associated with an increase in activity limitations in persons with early symptomatic knee osteoarthritis (OA), and to examine whether the longitudinal association between muscle strength and activity limitations is moderated by knee joint proprioception and laxity. A longitudinal cohort study with 3-year follow-up. Measurements were performed at the second (t0) and fifth (t1) year of the Cohort Hip and Cohort Knee (CHECK) study. Statistical analyses included paired t tests, chi-square tests, and regression analyses. In regression analyses, the association between muscle strength and activity limitations was adjusted for confounders. A rehabilitation and rheumatology center. Subjects (N=146) with early symptomatic knee OA from the CHECK study. Not applicable. Muscle strength, proprioception, and laxity were assessed using specifically designed measurement devices. Self-reported and performance-based activity limitations were measured with the Western Ontario and McMaster Universities Osteoarthritis Index, the Get Up and Go test, the walk test, and the stair-climb test. A total of 116 women (79.5%) and 30 men (20.5%), with a mean age ± SD of 58.4±4.9 years and a mean body mass index ± SD of 25.5±3.6, were included in the study. Overall, small 3-year changes in muscle strength and activity limitations were observed. At the group level, the average muscle strength increased by 10% (1.0±0.3 to 1.1±0.3Nm/kg) over the 3 years. The 3-year decrease in muscle strength was independently associated with an increase in performance-based activity limitations on all 3 measures (B=-1.12, B=-5.83, and B=-1.25, respectively). Proprioception and laxity did not moderate this association. In patients with early knee OA, decreased muscle strength is associated with an increase in activity limitations. Our results are a step toward understanding the role of muscle weakness in the development of activity limitations

  8. Plate coupling strength inferred from aftershock area expansion patterns and associated plate age

    NASA Astrophysics Data System (ADS)

    Tajima, F. C.

    2010-12-01

    Fault zone heterogeneity or plate boundary coupling in subduction zones has been debated repeatedly in numerous studies to understand the mechanisms that control characteristics of earthquake occurrence, i.e., typical moment release and degree of complexity of a mainshock rupture, and subsequent aftershock activity. Here we revisit a global survey of aftershock area expansion patterns of shallow large earthquakes (M≥˜7.5) focusing on the plate subduction boundaries (Tajima and Kanamori, 1985a,b), and attempt to relate the plate coupling strength to the sea floor age data compiled recently (Müller et al., 2008). The aftershock area S(t) (km2) was determined applying an objective method to draw contour maps for the seismic energy released from an aftershock sequence (i.e., 1015.6erg/100km2/day for the one-day aftershock area). Then, the expansion patterns are investigated as a function of time t (day) after the first day of aftershock activity, by the ratio of the aftershock area η(t) = S(t)/S(1) as well as the ratio of its length L(t) (km), ηl(t) = L(t)/L(1). The survey determined distinct regional variation that was interpreted in terms of plate coupling strength. In the subduction zones of Mexico, Alaska and parts of the South America the aftershock areas of large to great earthquakes show little expansion, and the coupling of the subducting and overlying plates is considered to be strong. In these regions relatively young (≤Miocene) plates are subducting beneath continents. In the Kuriles the aftershock area expansion of large events is widthwise indicating distinct boundaries lengthwise. The subduction zones are interpreted to be characterized by moderate to strong interplate coupling of two oceanic plates of a similar age (˜Cretaceus). Repeated large earthquakes in the Kuriles may have created “mature faults” of relatively loose mechanical coupling within distinct boundaries of strong coupling (asperities and barriers). In contrast, the aftershock

  9. Original Research: Effect of sprint and strength training on glucoregulatory hormones: Effect of advanced age

    PubMed Central

    Ben Abderrahman, Abderraouf; Kebsi, Wiem; De Sousa, Maysa Vieira; Zouhal, Hassane

    2016-01-01

    The aim of this study was to examine the effect of high-intensity sprint and strength training (HISST) on glucoregulatory hormones in young (20 years) and middle-aged (40 years) men. Thirty-six moderately trained men participated as volunteers in this study. After medical examination, eligible subjects were randomly assigned to one of four groups according to their age: a young training group (21.3 ± 1.3 yrs, YT, n = 9), a young control group (21.4 ± 1.7 yrs, YC, n = 9), a middle-aged training group (40.7 ± 1.8 yrs, AT, n = 9), and a middle-aged control group (40.5 ± 1.8 yrs, AC, n = 9). YT and AT participated in HISST for 13 weeks. Before and after HISST, all participants performed the Wingate Anaerobic Test (WAnT). Blood samples were collected at rest, after warm-up (50% VO2max), immediately post-WAnT, and 10 min post-WAnT. Before HISST, we observed significantly higher (P < 0.05) glucose concentrations in AT (5.86 ± 0.32 mmol.L−1) compared to YT (4.24 ± 0.79 mmol.L−1) at rest, and in response to WAnT (6.56 ± 0.63 mmol.L−1 vs. 5.33 ± 0.81 mmol.L−1). Cortisol levels were significantly higher (P < 0.05) in AT than in YT in response to WAnT (468 ± 99.50 ng.mL−1 vs. 382 ± 64.34 ng.mL−1). Catecholamine levels measured at rest and in response to WAnT rose in a similar fashion. After HISST, this “age effect” disappeared at rest and in response to exercise in the trained groups (YT and AT). Changes in hormone concentrations with intense training are due to adaptive changes in various tissues, especially in the skeletal muscle and liver in trained subjects. HISST may, at least in part, counteract the negative “age effect” on glucose metabolism. PMID:27470931

  10. Original Research: Effect of sprint and strength training on glucoregulatory hormones: Effect of advanced age.

    PubMed

    Sellami, Maha; Ben Abderrahman, Abderraouf; Kebsi, Wiem; De Sousa, Maysa Vieira; Zouhal, Hassane

    2017-01-01

    The aim of this study was to examine the effect of high-intensity sprint and strength training (HISST) on glucoregulatory hormones in young (20 years) and middle-aged (40 years) men. Thirty-six moderately trained men participated as volunteers in this study. After medical examination, eligible subjects were randomly assigned to one of four groups according to their age: a young training group (21.3 ± 1.3 yrs, YT, n = 9), a young control group (21.4 ± 1.7 yrs, YC, n = 9), a middle-aged training group (40.7 ± 1.8 yrs, AT, n = 9), and a middle-aged control group (40.5 ± 1.8 yrs, AC, n = 9). YT and AT participated in HISST for 13 weeks. Before and after HISST, all participants performed the Wingate Anaerobic Test (WAnT). Blood samples were collected at rest, after warm-up (50% VO2max), immediately post-WAnT, and 10 min post-WAnT. Before HISST, we observed significantly higher (P < 0.05) glucose concentrations in AT (5.86 ± 0.32 mmol.L(-1)) compared to YT (4.24 ± 0.79 mmol.L(-1)) at rest, and in response to WAnT (6.56 ± 0.63 mmol.L(-1) vs. 5.33 ± 0.81 mmol.L(-1)). Cortisol levels were significantly higher (P < 0.05) in AT than in YT in response to WAnT (468 ± 99.50 ng.mL(-1) vs. 382 ± 64.34 ng.mL(-1)). Catecholamine levels measured at rest and in response to WAnT rose in a similar fashion. After HISST, this "age effect" disappeared at rest and in response to exercise in the trained groups (YT and AT). Changes in hormone concentrations with intense training are due to adaptive changes in various tissues, especially in the skeletal muscle and liver in trained subjects. HISST may, at least in part, counteract the negative "age effect" on glucose metabolism.

  11. Are Noachian-age ridged plains (Nplr) actually early Hesperian in age

    NASA Technical Reports Server (NTRS)

    Frey, Herbert V.; Doudnikoff, C. E.; Mongeon, A. M.

    1990-01-01

    Whether or not the Nplr units in Memnonia and Argyre truly represent ridged plains volcanism of Noachian age or are simply areas of younger (Early Hesperian age) volcanism which failed to bury older craters and therefore have a greater total crater age than really applies to the ridged plains portion of those terrains is examined. The Nuekum and Hiller technique is used to determine the number of preserved crater retention surfaces in the Memnonia and Argyre regions where Scott and Tanaka show Nplr units to be common. The results for cratered terrain (Npl) in Memnonia is summarized along with those for ridged plains (Nplr) in both Memnonia and Argyre, and they are compared with similar results obtained for Tempe Terra and Lunae Plunum.

  12. Effect of Instrumentation Techniques, Irrigant Solutions and Artificial accelerated Aging on Fiberglass Post Bond Strength to Intraradicular Dentin.

    PubMed

    Santana, Fernanda Ribeiro; Soares, Carlos José; Silva, Júlio Almeida; Alencar, Ana Helena Gonçalves; Renovato, Sara Rodrigues; Lopes, Lawrence Gonzaga; Estrela, Carlos

    2015-07-01

    To evaluate the effect of instrumentation techniques, irrigant solutions and specimen aging on fiberglass posts bond strength to intraradicular dentine. A total of 120 bovine teeth were prepared and randomized into control and experimental groups resulting from three study factors (instrumentation techniques, irrigant solutions, specimen aging). Posts were cemented with RelyX U100. Samples were submitted to push-out test and failure mode was evaluated under a confocal microscope. In specimens submitted to water artificial aging, nickel-titanium rotary instruments group presented higher bond strength values in apical third irrigated with NaOCl or chlorhexi-dine. Irrigation with NaOCl resulted in higher bond strength than ozonated water. Artificial aging resulted in significant bond strength increase. Adhesive cement-dentin failure was prevalent in all the groups. Root canal preparation with NiTi instruments associated with NaOCl irrigation and ethylenediaminetetra acetic acid (EDTA) increased bond strength of fiberglass posts cemented with self-adhesive resin cement to intraradicular dentine. Water artificial aging significantly increased post-Clinical significance: The understanding of factors that may influence the optimal bond between post-cement and cement-dentin are essential to the success of endodontically treated tooth restoration.

  13. Comparison of Canadian firefighters and normal controls based on the submaximal fitness testing and strength considering age and gender.

    PubMed

    Nazari, Goris; MacDermid, Joy C; Kin, Kathryn E Sinden R; Overend, Tom J

    2017-09-07

    Few studies have addressed whether the firefighters are more fit than the general population and possess sufficient levels of aerobic capacity and muscle strength to perform on duty tasks in a safe and efficient manner, considering age and gender. We aimed to evaluate the fitness levels of Hamilton firefighters, and to determine the effects of age and gender. 89 participants were recruited. The Modified Canadian Aerobic Fitness Test was used to determine participants' estimated maximal oxygen consumptions (VO2-max) levels. For upper and lower body strength levels, a calibrated J-Tech hand held dynamometer and a National Institute for Occupational Safety and Health (NIOSH) lifting devices were used respectively. Firefighters' mean (standard deviations) VO2-max levels were 40.30 ± 6.25 ml·kg -1·min -1. Age proved to have a statistically significant impact on VO2-max - p < 0.001. Gender displayed statistically significant effects on strength levels. Firefighters' age was the only statistically significant independent variable, and accounted for 61.00% of the variance in firefighter aerobic capacity levels. Firefighters possessed somewhat similar aerobic capacities, but much higher levels of body strength when compared with the general population. With age, firefighters' aerobic capacities decreased, however their upper and lower body strength levels remained the same.

  14. Long-term outcome of gonadectomy performed at an early age or traditional age in dogs.

    PubMed

    Howe, L M; Slater, M R; Boothe, H W; Hobson, H P; Holcom, J L; Spann, A C

    2001-01-15

    To determine long-term results and complications of gonadectomy performed at an early age (prepubertal) or at the traditional age in dogs. Cohort study. 269 dogs from animal shelters. Dogs that underwent gonadectomy were allotted to 2 groups on the basis of estimated age at surgery (traditional age, > or =24 weeks old; prepubertal, < 24 weeks old). Adoptive owner information was obtained from shelter records, and telephone interviews were conducted with owners to determine physical or behavioral problems observed in the dogs since adoption. Follow-up information was obtained from attending veterinarians for dogs with complex problems or when owners were uncertain regarding the exact nature of their dog's problem. Prepubertal gonadectomy did not result in an increased incidence of behavioral problems or problems associated with any body system, compared with traditional-age gonadectomy, during a median follow-up period of 48 months after gonadectomy. Rate of retention in the original adoptive household was the same for dogs that underwent prepubertal gonadectomy as those that underwent traditional-age gonadectomy. Infectious diseases, however, were more common in dogs that underwent prepubertal gonadectomy. With the exception of infectious diseases, prepubertal gonadectomy may be safely performed in dogs without concern for increased incidence of physical or behavioral problems during at least a 4-year period after gonadectomy.

  15. Water consumption in Iron Age, Roman, and Early Medieval Croatia.

    PubMed

    Lightfoot, E; Slaus, M; O'Connell, T C

    2014-08-01

    Patterns of water consumption by past human populations are rarely considered, yet drinking behavior is socially mediated and access to water sources is often socially controlled. Oxygen isotope analysis of archeological human remains is commonly used to identify migrants in the archeological record, but it can also be used to consider water itself, as this technique documents water consumption rather than migration directly. Here, we report an oxygen isotope study of humans and animals from coastal regions of Croatia in the Iron Age, Roman, and Early Medieval periods. The results show that while faunal values have little diachronic variation, the human data vary through time, and there are wide ranges of values within each period. Our interpretation is that this is not solely a result of mobility, but that human behavior can and did lead to human oxygen isotope ratios that are different from that expected from consumption of local precipitation.

  16. Should we change targets and methods of early intervention in autism, in favor of a strengths-based education?

    PubMed

    Mottron, Laurent

    2017-02-08

    Early intensive behavioral intervention (EIBI) and its recent variant, naturalist developmental behavioral intervention (NDBI) aim to increase socialization and communication, and to decrease repetitive and challenging behaviors in preschool age autistic children. These behaviorist techniques are based on the precocity and intensity of the intervention, face-to-face interaction, errorless learning, and information fragmentation. Once considered to be "scientifically proven", the efficacy of these approaches has been called into question in the last decade due to poor-quality data, small effects, low cost-efficiency, and the evolution of ethical and societal standards. Grounded on a reappraisal of the genetic and cognitive neuroscience of autism, we question three aspects of EIBI/NDBI: their focus on prerequisites for typical socio-communicative behaviors, their lack of consideration of autistic language development and learning modes, and their negative view of repetitive behaviors and restricted interests. We propose alternative predictions for empirical validation, based on the strengths of prototypical autistic children: (a) their non-verbal intelligence should be normally distributed and within the normal range; (b) improving access to non-communicative verbal and written auditory language material should favor their subsequent speech development and

  17. Early strength response of the knee extensors during eight weeks of resistive training after unilateral total knee arthroplasty.

    PubMed

    Rossi, Mark D; Brown, Lee E; Whitehurst, Michael

    2005-11-01

    The purpose of this study was to document the early history of knee extensor torque production before and after total knee arthroplasty (TKA), explore the relationship between strength assessments, and describe an 8-week resistive-training protocol. Thirty-eight individuals (19 men, 19 women) with unilateral TKA volunteered to participate in this repeated-measures study. For this group, the mean age was 72.23 +/- 5.34 years; height was 168.00 +/- 8.57 cm; and weight was 79.42 +/- 14.57 kg. Torque production of the knee extensors was assessed isokinetically at 60 and 180 degrees .s(-1) before surgery, 30 days after unilateral TKA (+30), and 60 days after unilateral TKA (+60). Torque production was significantly different between limbs at both 60 and 180 degrees .s(-1) (p < 0.0125) before surgery. Torque production was lower at +30 compared with before surgery at both 60 and 180 degrees .s(-1) (p < 0.002). By +60, torque production was greater than at +30 at both 60 and 180 degrees .s(-1) (p < 0.002).

  18. Diurnal cortisol after early institutional care-Age matters.

    PubMed

    Flannery, Jessica E; Gabard-Durnam, Laurel J; Shapiro, Mor; Goff, Bonnie; Caldera, Christina; Louie, Jennifer; Gee, Dylan G; Telzer, Eva H; Humphreys, Kathryn L; Lumian, Daniel S; Tottenham, Nim

    2017-06-01

    Several studies have shown that young children who have experienced early caregiving adversity (e.g. previously institutionalization (PI)) exhibit flattened diurnal cortisol slopes; however, less is known about how these patterns might differ between children and adolescents, since the transition between childhood and adolescence is a time of purported plasticity in the hypothalamic-pituitary-adrenal (HPA) axis. PI youth experience a massive improvement in caregiving environment once adopted into families; therefore we anticipated that a developmental increase in HPA axis plasticity during adolescence might additionally allow for an enhanced enrichment effect by the adoptive family. In a cross-sectional sample of 197 youths (PI and Comparison; 4-15 years old) we observed age-related group differences in diurnal slope. First replicating previous findings, PI children exhibited flattened diurnal slope. This group difference, however, was not observed in adolescents. Moderation analyses showed that pubertal development, increased time with family, and early adoption contributed to the steeper diurnal cortisol slope in PI adolescents. These findings add support to existing theories positing that the transition between middle childhood and adolescence may mark an additional sensitive period for diurnal cortisol patterning, allowing PI youth to benefit from the enriched environment provided by adoptive parents during this period of development. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Effect of thermal aging on the tensile bond strength at reduced areas of seven current adhesives.

    PubMed

    Baracco, Bruno; Fuentes, M Victoria; Garrido, Miguel A; González-López, Santiago; Ceballos, Laura

    2013-07-01

    The purpose of this study was to determine the micro-tensile bond strength (MTBS) to dentin of seven adhesive systems (total and self-etch adhesives) after 24 h and 5,000 thermocycles. Dentin surfaces of human third molars were exposed and bonded with two total-etch adhesives (Adper Scotchbond 1 XT and XP Bond), two two-step self-etch adhesives (Adper Scotchbond SE and Filtek Silorane Adhesive System) and three one-step self-etch adhesives (G-Bond, Xeno V and Bond Force). All adhesive systems were applied following manufacturers' instructions. Composite buildups were constructed and the bonded teeth were then stored in water (24 h, 37 °C) or thermocycled (5,000 cycles) before being sectioned and submitted to MTBS test. Two-way ANOVA and subsequent comparison tests were applied at α = 0.05. Characteristic de-bonded specimens were analyzed using scanning electron microscopy (SEM). After 24 h water storage, MTBS values were highest with XP Bond, Adper Scotchbond 1 XT, Filtek Silorane Adhesive System and Adper Scotchbond SE and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. After thermocycling, MTBS values were highest with XP Bond, followed by Filtek Silorane Adhesive System, Adper Scotchbond SE and Adper Scotchbond 1 XT and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. Thermal aging induced a significant decrease in MTBS values with all adhesives tested. The resistance of resin-dentin bonds to thermal-aging degradation was material dependent. One-step self-etch adhesives obtained the lowest MTBS results after both aging treatments, and their adhesive capacity was significantly reduced after thermocycling.

  20. Early manifestations of replicative aging in the yeast Saccharomyces cerevisiae

    PubMed Central

    Sorokin, Maksim I.; Knorre, Dmitry A.; Severin, Fedor F.

    2014-01-01

    The yeast Saccharomyces cerevisiae is successfully used as a model organism to find genes responsible for lifespan control of higher organisms. As functional decline of higher eukaryotes can start as early as one quarter of the average lifespan, we asked whether S. cerevisiae can be used to model this manifestation of aging. While the average replicative lifespan of S. cerevisiae mother cells ranges between 15 and 30 division cycles, we found that resistances to certain stresses start to decrease much earlier. Looking into the mechanism, we found that knockouts of genes responsible for mitochondria-to-nucleus (retrograde) signaling, RTG1 or RTG3, significantly decrease the resistance of cells that generated more than four daughters, but not of the younger ones. We also found that even young mother cells frequently contain mitochondria with heterogeneous transmembrane potential and that the percentage of such cells correlates with replicative age. Together, these facts suggest that retrograde signaling starts to malfunction in relatively young cells, leading to accumulation of heterogeneous mitochondria within one cell. The latter may further contribute to a decline in stress resistances.

  1. Early manifestations of replicative aging in the yeast Saccharomyces cerevisiae.

    PubMed

    Sorokin, Maksim I; Knorre, Dmitry A; Severin, Fedor F

    2014-01-06

    The yeast Saccharomyces cerevisiae is successfully used as a model organism to find genes responsible for lifespan control of higher organisms. As functional decline of higher eukaryotes can start as early as one quarter of the average lifespan, we asked whether S. cerevisiae can be used to model this manifestation of aging. While the average replicative lifespan of S. cerevisiae mother cells ranges between 15 and 30 division cycles, we found that resistances to certain stresses start to decrease much earlier. Looking into the mechanism, we found that knockouts of genes responsible for mitochondria-to-nucleus (retrograde) signaling, RTG1 or RTG3, significantly decrease the resistance of cells that generated more than four daughters, but not of the younger ones. We also found that even young mother cells frequently contain mitochondria with heterogeneous transmembrane potential and that the percentage of such cells correlates with replicative age. Together, these facts suggest that retrograde signaling starts to malfunction in relatively young cells, leading to accumulation of heterogeneous mitochondria within one cell. The latter may further contribute to a decline in stress resistances.

  2. Effect of Strain-Induced Age Hardening on Yield Strength Improvement in Ferrite-Austenite Duplex Lightweight Steels

    NASA Astrophysics Data System (ADS)

    Song, Hyejin; Lee, Seok Gyu; Sohn, Seok Su; Kwak, Jai-Hyun; Lee, Sunghak

    2016-11-01

    Ferrite-austenite lightweight steels showing TRansformation-induced plasticity were developed by varying the aging temperature with or without prestraining, and their effects on tensile properties were investigated in relation with microstructural evolution of carbide formation. The aged steels contained austenite, pearlite, and martensite in the ferrite matrix, and the austenite volume fraction decreased with the increasing aging temperature because some austenite grains decomposed to pearlites. This austenite decomposition to pearlite was favorable for the improvement of yield strength, but negatively influenced overall tensile properties. The prestraining promoted the austenite decomposition by a diffusion-controlled phase transformation, and changed the morphology of the cementite from a long lamellar shape to a densely agglomerated particle shape. In order to obtain the large increase in yield strength as well as excellent combination of strength and ductility, the strain-induced aging treatment, i.e., prestraining followed by aging, is important like in the prestrained and 673 K (400 °C)-aged steel. This large increase in yield strength, in spite of a reduction of elongation (65 to 43 pct), was basically attributed to an appropriate amount of decomposition of austenite to pearlite ( e.g., 4 vol pct), while having sufficient austenite to martensite transformation ( e.g., 14.5 vol pct martensite).

  3. Strength training-induced responses in older adults: attenuation of descending neural drive with age.

    PubMed

    Unhjem, Runar; Lundestad, Raymond; Fimland, Marius Steiro; Mosti, Mats Peder; Wang, Eivind

    2015-06-01

    Although reductions in resting H-reflex responses and maximal firing frequency suggest that reduced efferent drive may limit muscle strength in elderly, there are currently no reports of V-wave measurements in elderly, reflecting the magnitude of efferent output to the muscle during maximal contraction. Furthermore, it is uncertain whether potential age-related neural deficiencies can be restored by resistance training. We assessed evoked reflex recordings in the triceps surae muscles during rest and maximal voluntary contraction (MVC), rate of force development (RFD), and muscle mass in seven elderly (74 ± 6 years) males before and after 8 weeks of heavy resistance training, contrasted by seven young (24 ± 4 years) male controls. At baseline, m. soleus (SOL) V/M ratio (0.124 ± 0.082 vs. 0.465 ± 0.197, p < 0.05) and H/M ratio (0.379 ± 0.044 vs. 0.486 ± 0.101 p = 0.07) were attenuated in elderly compared to young. Also, SOL H-reflex latency (33.29 ± 2.41 vs. 30.29 ± 0.67 ms, p < 0.05) was longer in elderly. The reduced neural drive was, despite similar leg muscle mass (10.7 ± 1.2 vs. 11.5 ± 1.4 kg), mirrored by lower MVC (158 ± 48 vs. 240 ± 54 Nm, p < 0.05) and RFD (294 ± 126 vs. 533 ± 123 Nm s(-1), p < 0.05) in elderly. In response to training SOL V/M ratio (0.184 ± 0.092, p < 0.05) increased in the elderly, yet only to a level ~40 % of the young. This was accompanied by increased MVC (190 ± 70 Nm, p < 0.05) and RFD (401 ± 147 Nm[Symbol: see text]s(-1), p < 0.05) to levels of ~80 % and ~75 % of the young. H/M ratio remained unchanged. These findings suggest that changes in supraspinal activation play a significant role in the age-related changes in muscle strength. Furthermore, this motor system impairment can to some extent be improved by heavy resistance training.

  4. The SAURON project - XVII. Stellar population analysis of the absorption line strength maps of 48 early-type galaxies

    NASA Astrophysics Data System (ADS)

    Kuntschner, Harald; Emsellem, Eric; Bacon, Roland; Cappellari, Michele; Davies, Roger L.; de Zeeuw, P. Tim; Falcón-Barroso, Jesús; Krajnović, Davor; McDermid, Richard M.; Peletier, Reynier F.; Sarzi, Marc; Shapiro, Kristen L.; van den Bosch, Remco C. E.; van de Ven, Glenn

    2010-10-01

    We present a stellar population analysis of the absorption line strength maps for 48 early-type galaxies from the SAURON sample. Using the line strength index maps of Hβ, Fe5015 and Mgb, measured in the Lick/IDS system and spatially binned to a constant signal-to-noise ratio, together with predictions from up-to-date stellar population models, we estimate the simple stellar population-equivalent (SSP-equivalent) age, metallicity and abundance ratio [α/Fe] over a two-dimensional field extending up to approximately one effective radius. A discussion of calibrations and differences between model predictions is given. Maps of SSP-equivalent age, metallicity and abundance ratio [α/Fe] are presented for each galaxy. We find a large range of SSP-equivalent ages in our sample, of which ~40 per cent of the galaxies show signs of a contribution from a young stellar population. The most extreme cases of post-starburst galaxies, with SSP-equivalent ages of <=3Gyr observed over the full field-of-view, and sometimes even showing signs of residual star formation, are restricted to low-mass systems (σe <= 100kms-1 or ~2 × 1010Msolar). Spatially restricted cases of young stellar populations in circumnuclear regions can almost exclusively be linked to the presence of star formation in a thin, dusty disc/ring, also seen in the near-UV or mid-IR on top of an older underlying stellar population. The flattened components with disc-like kinematics previously identified in all fast rotators are shown to be connected to regions of distinct stellar populations. These range from the young, still star-forming circumnuclear discs and rings with increased metallicity preferentially found in intermediate-mass fast rotators, to apparently old structures with extended disc-like kinematics, which are observed to have an increased metallicity and mildly depressed [α/Fe] ratio compared to the main body of the galaxy. The slow rotators, often harbouring kinematically decoupled components (KDC

  5. The effect of aging treatment on the fracture toughness and impact strength of injection molded Ni-625 superalloy parts

    SciTech Connect

    Özgün, Özgür; Yılmaz, Ramazan; Özkan Gülsoy, H.; Fındık, Fehim

    2015-10-15

    In this study, the effect of aging heat treatment on fracture toughness and impact strength of Ni-625 superalloy fabricated by using powder injection molding (PIM) method was examined. After a feedstock was prepared by mixing the prealloyed Ni-625 superalloy powder, which was fabricated by gas atomisation, with a polymeric binder system and then it was granulated, it was shaped through the use of injection. The molded specimens were sintered at 1300 °C for 3 h after a two-stage debinding process. Once the sintered specimens were treated in the solution at 1150 °C for 2 h, they were quenched. Aging treatment was performed by keeping specimens at 745 °C for 22 h. Fracture toughness and impact tests were performed on sintered and aged specimens. Microstructure examinations were performed by using optical microscope, scanning electron microscope, and transmission electron microscope. The results revealed that aging heat treatment led to the formation of some carbides and intermetallic phases in the microstructure. While the hardness of the aged specimens increased due to these phases, their fracture toughness and impact strength values decreased. - Highlights: • Ni-625 superalloy components were produced by means of powder injection molding. • The produced components were subjected to aging treatment. • Aging process provided approximately 50% increase in the hardness of components. • Intermetallic precipitates, carbides and TCP phases occurred within the aged parts. • Fracture toughness and impact strength values decreased due to the hard phases.

  6. Sarcopenia, Dynapenia, and the Impact of Advancing Age on Human Skeletal Muscle Size and Strength; a Quantitative Review

    PubMed Central

    Mitchell, W. Kyle; Williams, John; Atherton, Philip; Larvin, Mike; Lund, John; Narici, Marco

    2012-01-01

    Changing demographics make it ever more important to understand the modifiable risk factors for disability and loss of independence with advancing age. For more than two decades there has been increasing interest in the role of sarcopenia, the age-related loss of muscle or lean mass, in curtailing active and healthy aging. There is now evidence to suggest that lack of strength, or dynapenia, is a more constant factor in compromised wellbeing in old age and it is apparent that the decline in muscle mass and the decline in strength can take quite different trajectories. This demands recognition of the concept of muscle quality; that is the force generating per capacity per unit cross-sectional area (CSA). An understanding of the impact of aging on skeletal muscle will require attention to both the changes in muscle size and the changes in muscle quality. The aim of this review is to present current knowledge of the decline in human muscle mass and strength with advancing age and the associated risk to health and survival and to review the underlying changes in muscle characteristics and the etiology of sarcopenia. Cross-sectional studies comparing young (18–45 years) and old (>65 years) samples show dramatic variation based on the technique used and population studied. The median of values of rate of loss reported across studies is 0.47% per year in men and 0.37% per year in women. Longitudinal studies show that in people aged 75 years, muscle mass is lost at a rate of 0.64–0.70% per year in women and 0.80–00.98% per year in men. Strength is lost more rapidly. Longitudinal studies show that at age 75 years, strength is lost at a rate of 3–4% per year in men and 2.5–3% per year in women. Studies that assessed changes in mass and strength in the same sample report a loss of strength 2–5 times faster than loss of mass. Loss of strength is a more consistent risk for disability and death than is loss of muscle mass. PMID:22934016

  7. Implications of early Hesperian ages for presumed Noachian age volcanic flows on Mars

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    1992-01-01

    Volcanic resurfacing has been important in Martian history. Major common-age resurfacing events are recorded in the cumulative frequency curves for the highland/lowland transition zone in eastern Mars and elsewhere. Most obvious in all these regions is a major resurfacing at the early hesperian (EH) time of ridged plains (unit Hr) eruption in Lunae Planum and elsewhere. This event seems to have occurred with greater or lesser efficiency in nearly all terrains studied: ridged plains, knobby terrain, smooth plains, and adjacent cratered terrain. Volcanic processes have apparently dominated all other sources of resurfacing (aeolian, periglacial, impact, fluvial) throughout all Martian history.

  8. Are DXA/aBMD and QCT/FEA Stiffness and Strength Estimates Sensitive to Sex and Age?

    PubMed

    Rezaei, Asghar; Giambini, Hugo; Rossman, Timothy; Carlson, Kent D; Yaszemski, Michael J; Lu, Lichun; Dragomir-Daescu, Dan

    2017-09-22

    Dual X-ray absorptiometry (DXA) measures areal bone mineral density (aBMD) by simplifying a complex 3D bone structure to a 2D projection and is not equally effective for explaining fracture strength in women and men. Unlike DXA, subject-specific quantitative computed tomography-based finite element analysis (QCT/FEA) estimates fracture strength using 3D bone mineral distribution and geometry. By using experimentally-measured femoral stiffness and strength from a one hundred sample cadaveric cohort that included variations in sex and age, we wanted to determine if QCT/FEA estimates were able to better predict the experimental variations than DXA/aBMD. For each femur, DXA/aBMD was assessed and a QCT/FEA model was developed to estimate femoral stiffness and strength. Then, the femur was mechanically tested to fracture in a sideways fall on the hip position to measure stiffness and strength. DXA/aBMD and QCT/FEA estimates were compared for their sensitivity to sex and age with multivariate statistical analyses. When comparing the measured data with DXA/aBMD predictions, both age and sex were significant (p ≤ 0.0398) for both femoral stiffness and strength. However, QCT/FEA predictions of stiffness and strength showed sex was insignificant (p ≥ 0.23). Age was still significant (p ≤ 0.0072). These results indicate that QCT/FEA, unlike DXA/aBMD, accounted for bone differences due to sex.

  9. The effect of high-speed strength training on physical performance in young soccer players of different ages.

    PubMed

    Rodriguez-Rosell, David; Franco-Márquez, Felipe; Mora-Custodio, Ricardo; González-Badillo, Juan José

    2016-10-28

    The aim of the present study was to compare the effectiveness of low-load, low-volume weight training combined with plyometrics on strength, sprint and jump performance in soccer players of different ages. Eighty-six soccer players from the same academy were categorized into 3 groups by age (under 13 year, U13, n = 30; under 15, U15, n = 28; under 17, U17, n = 28) and then randomly assigned into two subgroups: a strength training group (STG) and a control group (CG). The strength training program was performed twice a week for 6 weeks and consisted of full squats (load: 45-60% 1RM; volume: 3 set of 8-4 repetitions), jumps and straight line sprint exercises. After training intervention, the STGs showed significant improvements in maximal strength (7.5-54.5%; p < 0.001), jump height (5.7-12.5%; p < 0.01 - 0.001) and sprint time (-3.7 to -1.2%; p < 0.05 - 0.001), whereas no significant gains were found for any variable in the CGs. Comparison between experimental groups resulted in a greater magnitude of change for U13 compared to U15 (ES: 0.10-0.53) and U17 (ES: 0.14-1.41) soccer players in most variables, whereas U15 showed higher improvements in jump and strength parameters than U17 (ES: 0.25-0.90) soccer players. Thus, although our results indicates that a combined weight training and plyometrics program may be effective in eliciting gains in strength, jump and sprint in soccer players of different ages, the training program used appears to be generally less effective as the age of the soccer players increased. Therefore, it appears that training characteristics (mainly volume, intensity and type of exercise) should be modified in relation to maturity status and initial strength level.

  10. Knee extensor strength and body weight in adolescent men and the risk of knee osteoarthritis by middle age.

    PubMed

    Turkiewicz, Aleksandra; Timpka, Simon; Thorlund, Jonas Bloch; Ageberg, Eva; Englund, Martin

    2017-10-01

    To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data on isometric knee extensor strength, weight, height, smoking, alcohol consumption, parental education and adult occupation from Swedish registries. We identified participants diagnosed with knee OA or knee injury from 1987 to 2010 through the National Patient Register. We estimated the HR of knee OA using multivariable-adjusted Cox proportional regression model. To assess the influence of adult knee injury and occupation, we performed a formal mediation analysis. The mean (SD) knee extensor strength was 234 (47) Nm, the mean (SD) weight was 66 (9.3) kg. During 24 years (median) of follow-up starting at the age of 35 years, 2049 persons were diagnosed with knee OA. The adjusted HR (95% CI) of incident knee OA was 1.12 (1.06 to 1.18) for each SD of knee extensor strength and 1.18 (1.15 to 1.21) per 5 kg of body weight. Fifteen per cent of the increase in OA risk due to higher knee extensor strength could be attributed to knee injury and adult occupation. Higher knee extensor strength in adolescent men was associated with increased risk of knee OA by middle age, challenging the current tenet of low muscle strength being a risk factor for OA. We confirmed higher weight to be a strong risk factor for knee OA. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Reliability of the Strengths and Difficulties Questionnaire in Japanese Preschool Children Aged 4–6 Years

    PubMed Central

    Doi, Yuriko; Ishihara, Kaneyoshi; Uchiyama, Makoto

    2014-01-01

    Background The Strengths and Difficulties Questionnaire (SDQ) has been widely used as a brief behavioral screening. The aim of this study was to examine the internal consistency and test-retest reliability of the 3- to 4-year-old version of the SDQ (SDQ 3–4) in Japanese preschool children. Methods The SDQ 3–4 was administered to 754 parents who had 4- to 6-year-old children attending kindergartens or childcare centers in Wako City, Japan, at 2 different times (Time 1 and Time 2) over a 2-week interval between June and July 2012. Cronbach’s α and correlation coefficients were used to examine internal consistency and test-retest reliability, respectively. Results Of 393 parents who returned their responses at Time 1 (response rate 52.1%), 383 were used for analysis after excluding 10 responses with missing data. Their children’s mean age was 4.7 (standard deviation 0.7) years. The internal consistency (Cronbach’s α) was good for the total difficulties score (0.74) and the prosocial behavior scale (0.70). However, it was slightly worse for the emotional symptoms, conduct problems, and hyperactivity scales (0.61–0.66) and poor for the peer problems scale (0.45). Of the 383 included respondents at Time 1, 211 parents returned their responses at Time 2 (response rate: 55.1%). Test-retest reliability (correlation coefficients) was good (0.73–0.82), except for the peer problems scale (0.58). Conclusions The results support the reliability of the SDQ 3–4 being satisfactory for the total difficulties score and prosocial behavior scale and being acceptable for the emotional symptoms, conduct problems, and hyperactivity scales in Japanese preschool children aged 4–6 years. PMID:25373462

  12. Disproportionate changes in skeletal muscle strength and size with resistance training and ageing.

    PubMed

    Degens, H; Erskine, R M; Morse, C I

    2009-01-01

    The ability of a muscle to shorten and produce force is crucial for locomotion, posture, balance and respiration. During a contraction, myosin heads on the myosin filament propel the actin filament via ATP hydrolysis, resulting in shortening of the muscle and/or force generation. The maximal shortening velocity of a muscle fibre is largely determined by the myosin ATPase activity, while maximal force is primarily determined by the cross-sectional area. Since most muscles are pennate rather than parallel-fibred and work at different lever ratios, muscle architecture and joint-tendon anatomy has to be taken into account to obtain the force and velocity characteristics of a muscle. Additionally, the recruitment of agonistic and antagonistic muscles will contribute to the torque generated during a contraction. Finally, tendon compliance may impact on the rate of force rise and force generated if it is such that the muscle contraction proceeds in the ascending limb of the length-tension relation. Even when magnetic resonance imaging and ultrasound, combined with EMG and/or electrical stimulation, have been applied to relate changes in muscle contractile properties to alterations in muscle size and architecture during ageing and resistance training, a disproportionate change in muscle strength and size remains to be explained.

  13. Influence Of Morphology And Strength On Front Crawl Swimming Speed In Junior And Youth Age Group Swimmers.

    PubMed

    Strzała, Marek; Stanula, Arkadiusz; Krężałek, Piotr; Ostrowski, Andrzej; Kaca, Marcin; Głąb, Grzegorz

    2017-07-08

    this study, conducted in two male age groups, was aimed at analysing the influence of body properties, dry-land strength and swimming strength on 50 m crawl (VCrawl). We examined two competitive groups, Youth (20.6 ± 1.05), and Junior, (17.3 ± 0.59), through: a. (lean) body mass (BM and LBM), (total) body height (BH and TBL) and arm span (AS); b. counter movement jump (CMJ) and maximum isometric strength of elbow and knee joints; c. tethered crawl strength. We hypothesized that a higher relationship of strength indices in younger swimmers in VCrawl and tethered swimming would be a better sprint performance predictor. the Junior group revealed a significant relationship between somatic traits (BM r = 0.63; BH r = 0.55; TBL r = 0.58; AS r = 0.52 with p < 0.05 LBM r = 0.78; with p < 0.01) and VCrawl, whereas such interplay was not found in the Youth group. General dry-land strength indices CMJ [cm], CMJ [J] or isometric strength of knee joint muscle flexors and extensors (r = 0.57; r = 0.69; r = 0.56; r = 0.57, respectively) also significantly correlated with VCrawl only in the Junior group. The Junior group's tethered swimming strength had a higher but not significant relationship with VCrawl. The Youth group instead achieved significantly higher VCrawl and stroke rate (SR). The SR revealed (r = 0.41, p= 0.014) a relationship with VCrawl only after combination of both groups. this study demonstrates a better strength relationship with VCrawl in the younger Junior group. In the future, evaluation of sprint swimming aptitudes, besides on the basis of somatic traits and properties of dry-land or water strength measurement, should be complemented by measurements of real sprint swimming technique parameters.

  14. Microstructure, properties, and age hardening behavior of a thermomechanically processed ultralow-carbon Cu-bearing high-strength steel

    NASA Astrophysics Data System (ADS)

    Ghosh, A.; Mishra, B.; Das, S.; Chatterjee, S.

    2005-03-01

    An ultralow-carbon steel alloyed with Ni, Mn, Mo, and Cu and microalloyed with Nb and Ti was subjected to a three-stage controlled rolling operation followed by water quenching. The effect of thermomechanical processing on the microstructure, mechanical properties, and age-hardening behavior of the steel was evaluated. The precipitation behavior of Cu at different aging temperatures was studied by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The high strength values obtained in the present steel are due to the fine-lath martensite structure along with tiny precipitates of microalloying carbide and carbonitride of Ti and Nb at all finish rolling temperatures (FRTs). The increased strength value at the lower FRT is due to the finer lath width and packet size of martensite. The large TiN particles and the coarse martensite-austenite (MA) constituents impaired the impact-toughness value of the steel at subambient temperature. On aging at different temperatures, a wide variation in structure and properties has been obtained. At low aging temperatures, coherent Cu particles form and a peak strength is obtained due to the formation of fine ɛ-Cu precipitates. On increasing aging temperatures, the Cu particle size increases, with a simultaneous decrease in dislocation density in the matrix resulting in a continuous decrease in strength.

  15. One-year aging effects on microtensile bond strengths of composite and repairs with different surface treatments.

    PubMed

    Souza, Marcela Oliveira de; Leitune, Vicente Castelo Branco; Rodrigues, Stéfani Becker; Samuel, Susana Maria Werner; Collares, Fabrício Mezzomo

    2017-01-05

    The present study aimed to evaluate effects of different surface treatments and aging of composite cylinders on bond strength of composite resin repair. Thirty-two composite cylinders were produced and divided into four groups according to type of surface treatment and storage time of composite cylinder and repair. Cylinder surface of control group (Gcontrol) received no treatment before composite repair. Other groups were sandblasted with aluminum oxide (GAl2O3), followed by silane (GAl2O3sil) or adhesive (GAl2O3ad). Composite cylinders were stored in artificial saliva for either 24 hours or 1 year. Repairs were performed and stored in artificial saliva for 24 hours or 1 year and repair strength was evaluated using microtensile bond strength test. Data were submitted to Student's t test, two-way ANOVA, and post hoc test for storage time and treatment (α = 0.05). Gcontrol group showed lower values of aging of composite cylinder and storage time of repair (24 hours or 1 year for both) compared with other groups (p < 0.05). GAl2O3ad and GAl2O3sil groups did not exhibit decreased microtensile bond strength with aged repairs (1 year; p > 0.05). Polymer degradation was significant for composite cylinders during the first year of storage in Gcontrol, GAl2O3, and GAl2O3ad groups (p < 0.05). In GAl2O3sil group, storage time of composite cylinders was not significant (p > 0.05). Aging of composite resin influenced bond strength of restoration repair for up to 1 year. Sandblasting with Al2O3, followed by application of silane layer, produced high bond strength after composite or repair aging.

  16. Heart Rate Dynamics after Combined Strength and Endurance Training in Middle-Aged Women: Heterogeneity of Responses

    PubMed Central

    Goldberger, Ary L.; Tulppo, Mikko P.; Laaksonen, David E.; Nyman, Kai; Keskitalo, Marko; Häkkinen, Arja; Häkkinen, Keijo

    2013-01-01

    The loss of complexity in physiological systems may be a dynamical biomarker of aging and disease. In this study the effects of combined strength and endurance training compared with those of endurance training or strength training alone on heart rate (HR) complexity and traditional HR variability indices were examined in middle-aged women. 90 previously untrained female volunteers between the age of 40 and 65 years completed a 21 week progressive training period of either strength training, endurance training or their combination, or served as controls. Continuous HR time series were obtained during supine rest and submaximal steady state exercise. The complexity of HR dynamics was assessed using multiscale entropy analysis. In addition, standard time and frequency domain measures were also computed. Endurance training led to increases in HR complexity and selected time and frequency domain measures of HR variability (P<0.01) when measured during exercise. Combined strength and endurance training or strength training alone did not produce significant changes in HR dynamics. Inter-subject heterogeneity of responses was particularly noticeable in the combined training group. At supine rest, no training-induced changes in HR parameters were observed in any of the groups. The present findings emphasize the potential utility of endurance training in increasing the complex variability of HR in middle-aged women. Further studies are needed to explore the combined endurance and strength training adaptations and possible gender and age related factors, as well as other mechanisms, that may mediate the effects of different training regimens on HR dynamics. PMID:24013586

  17. Effect of inflammation on handgrip strength in the non-critically ill is independent from age, gender and body composition.

    PubMed

    Norman, K; Stobäus, N; Kulka, K; Schulzke, J

    2014-02-01

    We investigated whether C-reactive protein (CRP) as indicator of acute inflammation is associated with maximal isometric handgrip strength in non-critically ill patients. Handgrip strength was measured with Jamar dynamometer in 620 hospitalized patients (56.4±15.9 years old, 52.3% men). CRP was measured with immunoturbidimetric assay. Fat free mass (FFM) was assessed by bioelectrical impedance analysis. A general linear model regression analysis corrected for confounding variables such as age, sex, FFM, body mass index, comorbidity count and diagnosis category (malignant/benign disease) was performed to test the association between elevated levels of CRP and handgrip strength. CRP was an independent predictor of grip strength (CRP: β-coefficient: -0.169, P=0.018) even after adjustment for relevant confounders. All groups with inflammation showed significant reduction in handgrip strength, corresponding to a loss of ∼1.6 kg in mild inflammation, 3.2 kg in moderate inflammation and 2.9 kg in severe inflammation compared with patients without inflammation. Our data demonstrate the independent association between inflammation and handgrip strength in non-critically ill patients. If not corrected, reduced strength may have implications for the patients' functional status and prognosis. Increasing physical activity and resistance training during convalescence are recommended.

  18. Modified forelimb grip strength test detects aging-associated physiological decline in skeletal muscle function in male mice.

    PubMed

    Takeshita, Hikari; Yamamoto, Koichi; Nozato, Satoko; Inagaki, Tadakatsu; Tsuchimochi, Hirotsugu; Shirai, Mikiyasu; Yamamoto, Ryohei; Imaizumi, Yuki; Hongyo, Kazuhiro; Yokoyama, Serina; Takeda, Masao; Oguro, Ryosuke; Takami, Yoichi; Itoh, Norihisa; Takeya, Yasushi; Sugimoto, Ken; Fukada, So-Ichiro; Rakugi, Hiromi

    2017-02-08

    The conventional forelimb grip strength test is a widely used method to assess skeletal muscle function in rodents; in this study, we modified this method to improve its variability and consistency. The modified test had lower variability among trials and days than the conventional test in young C57BL6 mice, especially by improving the variabilities in male. The modified test was more sensitive than the conventional test to detect a difference in motor function between female and male mice, or between young and old male mice. When the modified test was performed on male mice during the aging process, reduction of grip strength manifested between 18 and 24 months of age at the group level and at the individual level. The modified test was similar to the conventional test in detecting skeletal muscle dysfunction in young male dystrophic mice. Thus, the modified forelimb grip strength test, with its improved validity and reliability may be an ideal substitute for the conventional method.

  19. Early Holocene and Younger Dryas age glacier advances in Patagonia

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Harrison, S.; Schnabel, C.; Fabel, D.; Jansson, K.

    2012-12-01

    Reliable dating of Southern Hemisphere glacier fluctuations since the Last Glacial Maximum (LGM) is crucial to resolving debates about millennial-scale climate change. Here we present 10Be dates for lateral, valley-mouth and cross-valley moraines formed between the contemporary South American North Patagonian Icefield (NPI) and its LGM position in four separate valleys around 47oS. This is an area of climate sensitivity, near the core of the precipitation-bearing southern westerly winds (SWW). The dates indicate that outlet glaciers from an expanded NPI advanced to form large moraines at 10.8 ± 0.5 / 11.0 ± 0.6, 11.2 ± 0.6, 11.5 ± 0.6 and 12.5 ± 0.7 ka (Putnam southern hemisphere production rates and Dunai scaling scheme, zero-erosion). The first four ages are statistically indistinguishable and probably represent a single, regional ice advance. With a likely assumed boulder erosion rate of 2mm/ka, these ages become 11.0 ± 0.5 / 11.2 ± 0.6, 11.5 ± 0.6, 11.7 ± 0.6 and 12.8 ± 0.7 ka. With a higher (less likely) assumed boulder erosion rate of 10mm/ka these ages become 12.0 ± 0.5 / 12.1 ± 0.6, 12.4 ± 0.6, 12.8 ± 0.6 and 14.0 ± 0.7 ka. The dates indicate that glaciers in Patagonia were larger during these times than at any point since the LGM and provide evidence in Patagonia for glacier advances during the very early Holocene, around the time of the European Younger Dryas (12.9 to 11.7 ka) and the Antarctic Cold Reversal (ACR; 14.5 to 12.9 ka). Although palaeoclimatic records from this area are often contradictory, these glacier advances were probably associated with a period of regionally increased precipitation related to the changes in the position of the SWW or meltwater pulses associated with the ACR.

  20. Strength training as a countermeasure to aging muscle and chronic disease.

    PubMed

    Hurley, Ben F; Hanson, Erik D; Sheaff, Andrew K

    2011-04-01

    Strength training (ST) has long been considered a promising intervention for reversing the loss of muscle function and the deterioration of muscle structure associated with advanced age but, until recently, the evidence was insufficient to support its role in the prevention or treatment of disease. In recent decades, there has been a long list of quality reviews examining the effects of ST on functional abilities and a few on risk factors for specific diseases, but none have provided a comprehensive assessment of ST as an intervention for a broad range of diseases. This review provides an overview of research addressing the effectiveness of ST as an intervention for the prevention or treatment of the adverse consequences of (i) aging muscle; (ii) the metabolic syndrome (MetS) and its components, i.e. insulin resistance, abdominal obesity, hyperlipidaemia and hypertension; (iii) fibromyalgia; (iv) rheumatoid arthritis; and (v) Alzheimer's disease. Collectively, these studies indicate that ST may serve as an effective countermeasure to some of the adverse consequences of the MetS, fibromyalgia and rheumatoid arthritis. Evidence in support of the hypothesis that ST reduces insulin resistance or improves insulin action comes both from indirect biomarkers, such as glycosylated haemoglobin (HbA(1c)), and insulin responses to oral glucose tolerance tests, as well as from more direct procedures such as hyperglycaemic and hyperinsulinaemic-euglycaemic clamp techniques. The evidence for the use of ST as a countermeasure of abdominal obesity is less convincing. Although some reports show statistically significant reductions in visceral fat, it is unclear if the magnitude of these changes are physiologically meaningful and if they are independent of dietary influences. The efficacy of ST as an intervention for reducing dyslipidaemia is at best inconsistent, particularly when compared with other pharmacological and non-pharmacological interventions, such as aerobic exercise

  1. Maine Department of Education Regulation 180: Early Intervention and Special Education for Children Age Birth to under Age Six.

    ERIC Educational Resources Information Center

    Maine State Dept. of Education, Augusta.

    This document contains regulations governing the administration of the Childfind system for children age birth to under age 6, the provision of early intervention services to eligible children birth through two with disabilities and their families, and the provision of special education and related services to eligible children age 3 to under 6…

  2. Age-related changes in bone structure and strength in female and male BALB/c mice.

    PubMed

    Willinghamm, Mark D; Brodt, Michael D; Lee, Kristen L; Stephens, Abby L; Ye, Jiaxin; Silva, Matthew J

    2010-06-01

    Mice may be useful for studies of skeletal aging, but there are limited data on changes in bone structure and strength over their life span. We obtained bones from female and male BALB/c mice at ages 2, 4, 7, 12, and 20 months and evaluated their structural, densitometric, and mechanical properties. MicroCT of the mid-diaphysis of the femur and radius indicated that during skeletal growth (2-7 months) bone cross-sectional size (area, moment of inertia) increased rapidly; during aging (7-20 months) cortical area was maintained, while moment of inertia continued to increase. Bones from females were smaller than those from males at young ages but not at later ages. Changes in whole-bone stiffness and strength reflected the changes in bone size, with a rapid increase from 2 to 7 months, followed by little or no change. In contrast, energy-to-fracture declined with aging. Cortical tissue mineral density increased during growth and was maintained with aging. MicroCT of trabecular bone revealed age-related changes that were site-dependent. The proximal tibia showed a clear pattern of age-related decline in trabecular BV/TV, with progressive decreases after 4 months in both sexes; lumbar vertebra L5 had more modest age-related declines; in contrast, caudal vertebra Ca7 had increasing BV/TV with aging. Overall, we found no evidence that females had more pronounced age-related deterioration than males. We conclude that bones from aging female and male BALB/c mice exhibit many of the changes seen in humans and are therefore a clinically relevant model for studies of skeletal aging.

  3. Starting with Their Strengths: Using the Project Approach in Early Childhood Special Education. Early Childhood Education Series

    ERIC Educational Resources Information Center

    Lickey, Deborah C.; Powers, Denise J.

    2011-01-01

    This book provides a comprehensive and practical guide to using the project approach when teaching young children with special needs. While focusing on children's individual strengths, which include their interests, intelligences, and unique styles of learning, this resource demonstrates teaching strategies that address multiple areas of…

  4. Starting with Their Strengths: Using the Project Approach in Early Childhood Special Education. Early Childhood Education Series

    ERIC Educational Resources Information Center

    Lickey, Deborah C.; Powers, Denise J.

    2011-01-01

    This book provides a comprehensive and practical guide to using the project approach when teaching young children with special needs. While focusing on children's individual strengths, which include their interests, intelligences, and unique styles of learning, this resource demonstrates teaching strategies that address multiple areas of…

  5. Influences of multiple firings and aging on surface roughness, strength and hardness of veneering ceramics for zirconia frameworks.

    PubMed

    Tang, Xuehua; Luo, Huinan; Bai, Yang; Tang, Hui; Nakamura, Takashi; Yatani, Hirofumi

    2015-09-01

    To evaluate the effects of multiple firings and aging on surface roughness, strength, and hardness of veneering ceramics for zirconia frameworks. Five different veneering ceramics for zirconia frameworks were used: Vintage ZR (ZR), Cerabien ZR (CZR), VitaVM9 (VM9), Cercon ceram KISS (KISS), and IPS e.max ceram (e.max). Specimens were fired 2 or 10 times in order to accelerate aging. Surface roughness was evaluated using laser profilometry. Flexural strength and Vickers hardness were also measured. Surface topography was observed using scanning electron microscopy. After accelerated aging, the surface roughness of all specimens fired 10 times was significantly lower than that of the same specimens fired 2 times (P=0.000). Except for VM9, the flexural strength of all specimens fired 10 times was greater than that of the same specimens fired 2 times, and the differences were significant for ZR and CZR (P<0.01). The flexural strength of VM9 fired 10 times was significantly lower than that of VM9 fired 2 times (P=0.034). The Vickers hardness of ZR and VM9 fired 10 times was significantly higher than that of the same specimens fired 2 times (P<0.05), but that of KISS fired 10 times was significantly lower than that of KISS fired 2 times (P=0.000). Multiple firings had a positive effect on the surface roughness of all aged veneering ceramics used for zirconia restorations and on the strength and hardness of many aged veneering ceramics used for zirconia restorations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Star formation history of early-type galaxies in low density environments. I. Nuclear line-strength indices

    NASA Astrophysics Data System (ADS)

    Longhetti, M.; Rampazzo, R.; Bressan, A.; Chiosi, C.

    1998-06-01

    This paper is the first of a series \\cite[(Longhetti et al. 1997a,b)]{lon97} dedicated to the study of the star formation history in early-type galaxies which show fine structures and/or signatures of interaction. It presents nuclear line-strength indices for a sample composed of 21 shell galaxies, from the \\cite[Malin & Carter (1983)]{mal83} southern survey, and 30 members of isolated interacting pairs, from the \\cite[Reduzzi & Rampazzo (1995)]{red95} catalogue, located in low density environments. The spectral range covers 3700 Angstroms < lambda < 5700 Angstroms at 2.1 Angstroms FWHM resolution. We measure 16 red (lambda > 4200 Angstroms) indices defined by the Lick Group. Measures have been transformed into the Lick-IDS ``standard'' system. The procedure has been tested on a set of 5 elliptical galaxies selected from the \\cite[Gonzalez (1993)]{gon93} sample. We derive also three blue (lambda < 4200) indices, namely Delta (4000 Angstroms) defined by \\cite[Hamilton (1985)]{ham85}, H+K(CaII) and Hdelta /FeI defined by \\cite[Rose (1984, 1985)]{ros84}. Blue indices are correlated to the age of the last starburst occurred in a galaxy \\cite[(Leonardi & Rose 1996)]{leo96}. The determination of these indices, the estimate of the measurement errors and the correction for the galaxies velocity dispersions are discussed in detail. In the Appendix A we present the indices for a set of hot stars (T> 10000 K) which may be used for extending W92 fitting functions toward high temperatures. Based on observations obtained at ESO, La Silla, Chile. Tables 1-8 are also available in electronic form at CDS and Tables 9-15 are only available in electronic form at CDS: via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

  7. Effect of Oil Application, Age, Diet, and Pigmentation on the Tensile Strength and Breaking Point of Hair.

    PubMed

    Kavitha, S; Natarajan, Karthika; Thilagavathi, G; Srinivas, C R

    2016-01-01

    Hair strength depends on various factors such as nutrition, environmental factors, sunlight, oiling, aging, conditioner, etc. To compare the tensile strength and breaking point of the hair shaft between (1) vegetarian and nonvegetarian. (2) Those who regularly apply and those who do not apply oil. (3) Pigmented and nonpigmented hair, (4) childhood and elderly. Hair fibers were mounted in tensile strength testing machine Zwick/Roell Z010 and gradual force was administered. The elongation of hair fiber in mm and the maximum force required to break the hair strand were recorded for each fiber. Elasticity of the children's hair was more than the elasticity of adult (P = 0.05) although tensile strength in children hair was not statistically significant (>0.05). Similarly, the tensile strength was more among those who regularly consumed nonvegetarian food but the difference was not statistically significant (P > 0.05). There was no statistically significant difference in other groups (P > 0.05). Elasticity in children hair is statistically more than elderly hair although there is no significant change in tensile strength.

  8. Age as a moderator of the secular trend for grip strength in Canada and the United States.

    PubMed

    Silverman, Irwin W

    2015-01-01

    To determine whether grip strength changed on average over recent decades at each of two age levels (children and adolescents versus adults) in Canada and the US. For each sex, weighted least squares regression analyses were performed on mean grip strength values as reported in studies conducted from the 1960s onwards. Grip strength did not change significantly as a function of year tested in children and adolescents, whereas it declined as a negatively accelerated function of year tested in adults. The results are contrary to what might be expected given that body weight has increased in both countries in recent decades and given that grip strength has been found to be positively correlated with body weight. It is suggested that there was a concurrent change in a factor that operated to counteract the effect of increased body weight on grip strength, a prime candidate being a decrease in levels of serum vitamin D. It is also suggested that the secular decline in adult grip strength can be explained by a factor that affects muscular function but which has a long latency period, a prime candidate here being obesity history.

  9. Opaque layer firing temperature and aging effect on the flexural strength of ceramic fused to cobalt-chromium alloy.

    PubMed

    de Vasconcellos, Luis Gustavo Oliveira; Buso, Leonardo; Lombardo, Geraldo H L; Souza, Rodrigo O A; Nogueira, Lafayette; Bottino, Marco Antonio; Ozcan, Mutlu

    2010-08-01

    To evaluate the effect of the opaque layer firing temperature and mechanical and thermal cycling on the flexural strength of a ceramic fused to commercial cobalt-chromium alloy (Co-Cr). The hypotheses were that higher opaque layer temperatures increase the metal/ceramic bond strength and that aging reduces the bond strength. Metallic frameworks (25 x 3 x 0.5 mm(3); ISO 9693) (N = 60) were cast in Co-Cr and airborne-particle abraded (Al(2)O(3): 150 mum) at the central area of the frameworks (8 x 3 mm(2)) and divided into three groups (N = 20), according to the opaque layer firing temperature: Gr1 (control)-900 degrees C; Gr2-950 degrees C; Gr3-1000 degrees C. The opaque ceramic (Opaque, Vita Zahnfabrick, Bad Säckingen, Germany) was applied, and the glass ceramic (Vita Omega 900, Vita Zahnfabrick) was fired onto it (thickness: 1 mm). While half the specimens from each group were randomly tested without aging (water storage: 37 degrees C/24 hours), the other half were mechanically loaded (20,000 cycles; 50 N load; distilled water at 37 degrees C) and thermocycled (3000 cycles; 5 degrees C to 55 degrees C, dwell time: 30 seconds). After the flexural strength test, failure types were noted. The data were analyzed using 2-way ANOVA and Tukey's test (alpha= 0.05). Gr2 (19.41 +/- 5.5 N) and Gr3 (20.6 +/- 5 N) presented higher values than Gr1 (13.3 +/- 1.6 N) (p= 0.001). Mechanical and thermal cycling did not significantly influence the mean flexural strength values (p > 0.05). Increasing the opaque layer firing temperature improved the flexural bond strength values (p < 0.05). The hypotheses were partially accepted. Increasing of the opaque layer firing temperature improved the flexural bond strength between ceramic fused to Co-Cr alloy.

  10. Younger Dryas and early Holocene age glacier advances in Patagonia

    NASA Astrophysics Data System (ADS)

    Glasser, Neil F.; Harrison, Stephan; Schnabel, Christoph; Fabel, Derek; Jansson, Krister N.

    2012-12-01

    Reliable dating of Southern Hemisphere glacier fluctuations since the Last Glacial Maximum (LGM) is crucial to resolving debates about millennial-scale climate change. Here we present 10Be dates for lateral, valley-mouth and cross-valley moraines formed between the contemporary South American North Patagonian Icefield (NPI) and its LGM position in four separate valleys around 47°S. This is an area near the core of the precipitation-bearing southern westerly winds, where it is known that rapid shifts in climate occurred during Lateglacial times. The dates indicate that outlet glaciers advanced, or at least stabilised, to form large moraines east of an expanded NPI at 11.0 ± 0.5/11.2 ± 0.6, 11.5 ± 0.6, 11.7 ± 0.6 and 12.8 ± 0.7 ka (Putnam southern-hemisphere production rates and Dunai scaling scheme, assumed boulder erosion rate of 2 mm/ka). Four of these ages are statistically indistinguishable and probably represent a single, regional ice advance. The dates indicate that glaciers in Patagonia were larger during these times than at any point since the LGM and provide evidence in Patagonia for glacier advances around the time of the European Younger Dryas (12.9-11.7 ka) and into the very early Holocene. Although palaeoclimatic records from this area are often contradictory, these glacier advances were probably associated with a period of cooling or regionally increased precipitation related to the changes in the position of the southern westerly winds.

  11. The association of ACE, ACTN3 and PPARA gene variants with strength phenotypes in middle school-age children.

    PubMed

    Ahmetov, Ildus I; Gavrilov, Dmitry N; Astratenkova, Irina V; Druzhevskaya, Anastasiya M; Malinin, Alexandr V; Romanova, Elena E; Rogozkin, Victor A

    2013-01-01

    The aim of the study was to determine the association between ACE I/D, ACTN3 R577X and PPARA intron 7 G/C gene polymorphisms and strength-related traits in 457 middle school-age children (219 boys and 238 girls; aged 11 ± 0.4 years). The assessment of different phenotypes was conducted with a number of performance tests. Gene polymorphisms were determined by PCR. The ACE D allele was associated with high results of standing long-jump test in boys [II 148.3 (16.3) cm, ID 152.6 (19.6) cm, DD 158.2 (19.1) cm; P = 0.037]. The ACTN3 R allele was associated with high results of performance tests in males only in combination with other genes (standing long-jump test: P = 0.021; handgrip strength test: P < 0.0001). Furthermore, the male carriers of the PPARA gene C allele demonstrated the best results of handgrip strength testing than GG homozygotes [GG 14.6 (4.0) kg, GC/CC 15.7 (4.3) kg; P = 0.048]. Thus, the ACE, ACTN3 and PPARA gene variants are associated with strength-related traits in physically active middle school-age boys.

  12. Is alcohol binge drinking in early and late pregnancy associated with behavioural and emotional development at age 7 years?

    PubMed

    Niclasen, Janni; Andersen, Anne-Marie Nybo; Strandberg-Larsen, Katrine; Teasdale, Thomas William

    2014-12-01

    The purpose of this study was to investigate associations of maternal binge drinking in early and late pregnancy with child behavioural and emotional development at age seven. It was hypothesised that late exposure is associated with more negative outcomes than early exposure. Differences were expected on the continuous outcome measures, but not on above cutoff scale scores. Data were derived from the Danish National Birth Cohort. Three exposure groups were defined according to binge drinking from three interviews regarding binge episodes in early, middle and late pregnancy. A 'no binge' group included women with no binge episodes reported in any of the interviews, the 'early bingers' reported episodes in the first interview only, and the 'late bingers' in the last part of pregnancy only. The outcome measure was the Strengths and Difficulties Questionnaire (SDQ) used as continuous externalising/internalising scores and above cutoff hyperactivity/inattention, conduct, emotional and peer problems scores. Only women with full information concerning binge drinking from the three interviews, together with full-scale SDQ information on their children at age seven and being term-born, were included in the study (N = 37,315). After adjustment for maternal education, psychiatric diagnoses, age and smoking, children exposed to binge drinking in early and late pregnancy had significantly higher mean externalizing scores at age seven than unexposed children, an effect albeit much less for early binge drinking (relative change in mean 1.02, CI 1.00-1.05) than for late binge drinking (relative change in mean 1.21, CI 1.04-1.42). No associations were observed for any of the above cutoff outcomes. Exposure to binge drinking in early and late pregnancy is associated with elevated externalising scores, particularly so in late pregnancy. No increased risk for any of the above cutoff scale scores was observed.

  13. Norms for hand grip strength.

    PubMed Central

    Newman, D G; Pearn, J; Barnes, A; Young, C M; Kehoe, M; Newman, J

    1984-01-01

    Norms for hand grip strength of healthy children are presented. Sex and age specific centiles for age 5 to 18 years have been determined using a portable strain gauge dynamometer with an accuracy of 0.5 N. The test group comprised 1417 healthy, urban school children from a middle class suburb of Brisbane. Mean maximum grip strength (of four tests, two with each hand) and mean peak grip strength (best of four tests) were recorded. Mean values of peak grip strength were 10 to 15% higher than the average maximum grip in all age groups. At all ages girls had a reduced grip strength compared with boys and although boys manifested a continual, approximately linear increase in grip strength through all age groups, girls manifested an approximately linear increase up to 13 years after which mean hand grip usually remained constant. By the age of 18 years boys had a mean grip strength some 60% higher than girls. Correlations with height and weight are also presented. "Handedness' influenced grip strength and was most noticeable in children aged over 10 years. The clinical use of hand grip strength centiles for the early indication of neurological and muscular disorders and for following the natural history of neuromuscular disease is discussed. Images Fig. 1 PMID:6732276

  14. Early plant embryogenesis-dark ages or dark matter?

    PubMed

    Bayer, Martin; Slane, Daniel; Jürgens, Gerd

    2017-02-01

    In nearly all flowering plants, the basic body plan is laid down during embryogenesis. In Arabidopsis, the crucial cell types are established extremely early as reflected in the stereotypic sequence of oriented cell divisions in the developing young embryo. Research into early embryogenesis was especially focused on the role of the infamous tryptophan derivative auxin in establishing embryo polarity and generating the main body axis. However, it is becoming obvious that the mere link to auxin does not provide any mechanistic understanding of early embryo patterning. Taking recent research into account, we discuss mechanisms underlying early embryonic patterning from an evolutionary perspective.

  15. Lower limb muscle strength is associated with poor balance in middle-aged women: linear and nonlinear analyses.

    PubMed

    Wu, F; Callisaya, M; Laslett, L L; Wills, K; Zhou, Y; Jones, G; Winzenberg, T

    2016-07-01

    This was the first study investigating both linear associations between lower limb muscle strength and balance in middle-aged women and the potential for thresholds for the associations. There was strong evidence that even in middle-aged women, poorer LMS was associated with reduced balance. However, no evidence was found for thresholds. Decline in balance begins in middle age, yet, the role of muscle strength in balance is rarely examined in this age group. We aimed to determine the association between lower limb muscle strength (LMS) and balance in middle-aged women and investigate whether cut-points of LMS exist that might identify women at risk of poorer balance. Cross-sectional analysis of 345 women aged 36-57 years was done. Associations between LMS and balance tests (timed up and go (TUG), step test (ST), functional reach test (FRT), and lateral reach test (LRT)) were assessed using linear regression. Nonlinear associations were explored using locally weighted regression smoothing (LOWESS) and potential cut-points identified using nonlinear least-squares estimation. Segmented regression was used to estimate associations above and below the identified cut-points. Weaker LMS was associated with poorer performance on the TUG (β -0.008 (95 % CI: -0.010, -0.005) second/kg), ST (β 0.031 (0.011, 0.051) step/kg), FRT (β 0.071 (0.047, 0.096) cm/kg), and LRT (β 0.028 (0.011, 0.044) cm/kg), independent of confounders. Potential nonlinear associations were evident from LOWESS results; significant cut-points of LMS were identified for all balance tests (29-50 kg). However, excepting ST, cut-points did not persist after excluding potentially influential data points. In middle-aged women, poorer LMS is associated with reduced balance. Therefore, improving muscle strength in middle-age may be a useful strategy to improve balance and reduce falls risk in later life. Middle-aged women with low muscle strength may be an effective target group for future randomized

  16. Heterogeneity in resistance training-induced muscle strength and mass responses in men and women of different ages.

    PubMed

    Ahtiainen, Juha P; Walker, Simon; Peltonen, Heikki; Holviala, Jarkko; Sillanpää, Elina; Karavirta, Laura; Sallinen, Janne; Mikkola, Jussi; Valkeinen, Heli; Mero, Antti; Hulmi, Juha J; Häkkinen, Keijo

    2016-02-01

    Physical activity recommendations for public health include typically muscle-strengthening activities for a minimum of 2 days a week. The range of inter-individual variation in responses to resistance training (RT) aiming to improve health and well-being requires to be investigated. The purpose of this study was to quantify high and low responders for RT-induced changes in muscle size and strength and to examine possible effects of age and sex on these responses. Previously collected data of untrained healthy men and women (age 19 to 78 years, n = 287 with 72 controls) were pooled for the present study. Muscle size and strength changed during RT are 4.8 ± 6.1 % (range from -11 to 30 %) and 21.1 ± 11.5 % (range from -8 to 60 %) compared to pre-RT, respectively. Age and sex did not affect to the RT responses. Fourteen percent and 12 % of the subjects were defined as high responders (>1 standard deviation (SD) from the group mean) for the RT-induced changes in muscle size and strength, respectively. When taking into account the results of non-training controls (upper 95 % CI), 29 and 7 % of the subjects were defined as low responders for the RT-induced changes in muscle size and strength, respectively. The muscle size and strength responses varied extensively between the subjects regardless of subject's age and sex. Whether these changes are associated with, e.g., functional capacity and metabolic health improvements due to RT requires further studies.

  17. Effect of Aging on Bond Strength of Two Soft Lining Materials to a Denture Base Polymer.

    PubMed

    Salloum, Alaa'a M

    2014-12-01

    The purpose of this study was evaluation the effect of immersion in distilled water and inorganic artificial saliva on the shear bond strength of a heat-polymerized and an auto-polymerized silicone-based denture lining materials. The denture liners investigated were Molloplast-B (heat-polymerized), and Mollosil plus (auto-polymerized). The soft liner specimens were 10 × 10 × 2.5 mm and were processed between two poly(methylmethacrylate) plates. Thirty shear specimens for each type of test lining material were prepared. Specimens were divided equally into three groups for each test lining material: first group, specimens were tested after 48 h of preparation without immersion; second group, specimens were tested following immersion in distilled water at 37 °C for 12 months; and third group, specimens were tested following immersion in inorganic artificial saliva at 37 °C for 12 months. Shear bond strength was measured using an universal testing machine at a crosshead speed of 40 mm/min and failure mode (adhesive, cohesive and mixed) after debonding was assessed. Data were statistically analyzed with one-way analysis of variance (ANOVA) (α = 0.05). ANOVA was followed by Bonferroni post hoc tests for pairwise comparisons. A significant difference in shear bond strength was detected between Molloplast-B and Mollosil plus following immersion in distilled water and artificial saliva. Molloplast-B demonstrated considerably higher shear strength than Mollosil plus after immersion. Shear strengths of the lining materials investigated reduced significantly after immersion in both solutions. Visual examination after separation revealed that the soft materials tested exhibited mostly adhesive failure. The effect of immersion in distilled water and inorganic artificial saliva on bond strength of test lining materials was perceivable; however, both of them had acceptable bond strength and might be proper for long-term use.

  18. Cervical range of motion, cervical and shoulder strength in senior versus age-grade Rugby Union International front-row forwards.

    PubMed

    Davies, Mark; Moore, Isabel S; Moran, Patrick; Mathema, Prabhat; Ranson, Craig A

    2016-05-01

    To provide normative values for cervical range of motion (CROM), isometric cervical and shoulder strength for; International Senior professional, and International Age-grade Rugby Union front-row forwards. Cross-sectional population study. All international level front-row players within a Rugby Union Tier 1 Nation. Nineteen Senior and 21 Age-grade front-row forwards underwent CROM, cervical and shoulder strength testing. CROM was measured using the CROM device and the Gatherer System was used to measure multi-directional isometric cervical and shoulder strength. The Age-grade players had significantly lower; cervical strength (26-57% deficits), cervical flexion to extension strength ratios (0.5 vs. 0.6), and shoulder strength (2-36% deficits) than the Senior players. However, there were no differences between front-row positions within each age group. Additionally, there were no differences between age groups or front-row positions in the CROM measurements. Senior Rugby Union front-row forwards have greater cervical and shoulder strength than Age-grade players, with the biggest differences being in cervical strength, highlighting the need for age specific normative values. Importantly, Age-grade players should be evaluated to ensure they have developed sufficient cervical strength prior to entering professional level Rugby Union. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Model Development and Trial of Early Detection Manual for the Special Needs Children at Early Age Education Level

    ERIC Educational Resources Information Center

    Anwar, Zainul; Ingarianti, Tri Muji; Suryaningrum, Cahyaning

    2016-01-01

    This research was aimed to produce the manual for early detection for ABK at the level of early age education (PAUD = "Pendidikan Anak Usia Dini"). Research was "action research" with stages as proposed by Buunk and Van Vugt. Metodology of research these stages were called as PATH ("Problem-Analysis-Test…

  20. Vertebral Size, Bone Density, and Strength in Men and Women Matched for Age and Areal Spine BMD

    PubMed Central

    Bruno, Alexander G; Broe, Kerry E; Zhang, Xiaochun; Samelson, Elizabeth J; Meng, Ching-An; Manoharan, Rajaram; D’Agostino, John; Cupples, L Adrienne; Kiel, Douglas P; Bouxsein, Mary L

    2014-01-01

    To explore the possible mechanisms underlying sex-specific differences in skeletal fragility that may be obscured by two-dimensional areal bone mineral density (aBMD) measures, we compared quantitative computed tomography (QCT)-based vertebral bone measures among pairs of men and women from the Framingham Heart Study Multidetector Computed Tomography Study who were matched for age and spine aBMD. Measurements included vertebral body cross-sectional area (CSA, cm2), trabecular volumetric BMD (Tb.vBMD, g/cm3), integral volumetric BMD (Int.vBMD, g/cm3), estimated vertebral compressive loading and strength (Newtons) at L3, the factor-of-risk (load-to-strength ratio), and vertebral fracture prevalence. We identified 981 male-female pairs (1:1 matching) matched on age (± 1 year) and QCT-derived aBMD of L3 (± 1%), with an average age of 51 years (range 34 to 81 years). Matched for aBMD and age, men had 20% larger vertebral CSA, lower Int.vBMD (−8%) and Tb.vBMD (−9%), 10% greater vertebral compressive strength, 24% greater vertebral compressive loading, and 12% greater factor-of-risk than women (p < 0.0001 for all), as well as higher prevalence of vertebral fracture. After adjusting for height and weight, the differences in CSA and volumetric bone mineral density (vBMD) between men and women were attenuated but remained significant, whereas compressive strength was no longer different. In conclusion, vertebral size, morphology, and density differ significantly between men and women matched for age and spine aBMD, suggesting that men and women attain the same aBMD by different mechanisms. These results provide novel information regarding sex-specific differences in mechanisms that underlie vertebral fragility. PMID:23955966

  1. Effect of age at menopause on disease presentation in early rheumatoid arthritis: results from the Canadian Early Arthritis Cohort.

    PubMed

    Wong, Lauren E; Huang, Wei-Ti; Pope, Janet E; Haraoui, Boulos; Boire, Gilles; Thorne, J Carter; Hitchon, Carol A; Tin, Diane; Keystone, Edward C; Bykerk, Vivian P

    2015-05-01

    Studies suggest that hormonal states affect disease characteristics in women with rheumatoid arthritis (RA). This study investigated how age at menopause affects disease in women presenting with early RA. This was a cross-sectional study of postmenopausal women with early RA under age 65 years at time of enrollment in the Canadian Early Arthritis Cohort. RA-related disease characteristics in women who had early age at menopause (EM; age at menopause <45 years) were compared to those who had usual age at menopause (age at menopause ≥45 years). The t-test was applied to continuous variables and the chi-square test to categorical variables. Multivariate logistic regression analysis was used to adjust for age at menopause, smoking, and use of exogenous hormones. A total of 534 women were included; 93 were in the EM group. The age at RA onset was similar between groups. The EM group had higher mean patient global and pain scores and was more likely to be rheumatoid factor (RF) positive and meet the 1987 American College of Rheumatology criteria for RA. Using multivariate logistic regression, the EM group was more likely to be RF positive (odds ratio 2.2 [95% confidence interval 1.3-3.8], P = 0.005). Symptom duration, joint counts, Disease Activity Score in 28 joints, Health Assessment Questionnaire scores, and inflammatory markers did not differ between groups. These data suggest that early age at menopause, compared to usual age at menopause, is associated with seropositivity in women with early RA. © 2015, American College of Rheumatology.

  2. Low ponderal index is associated with decreased muscle strength and fatigue resistance in college-aged women

    PubMed Central

    Brutsaert, Tom D.; Tamvada, Kelli H.; Kiyamu, Melisa; White, Daniel D.; Gage, Timothy B

    2011-01-01

    Poor fetal growth is associated with decrements in muscle strength likely due to changes during myogenesis. We investigated the association of poor fetal growth with muscle strength, fatigue resistance, and the response to training in the isolated quadriceps femoris. Females (20.6 yrs) born to term but below the 10th percentile of ponderal index (PI)-for-gestational-age (LOWPI, n=14) were compared to controls (HIGHPI, n=14), before and after an 8-week training. Muscle strength was assessed as grip-strength and as the maximal isometric voluntary contraction (MVC) of the quadriceps femoris. Muscle fatigue was assessed during knee extension eercise. Body composition and the maximal oxygen consumption (VO2max) were also measured. Controlling for fat free mass (FFM), LOWPI versus HIGHPI women had ~11% lower grip-strength (P=0.023), 9–24% lower MVC values (P=0.042 pre-trained; P=0.020 post-trained), a higher rate of fatigue (pre- and post-training), and a diminished training response (P=0.016). Statistical control for FFM increased rather than decreased strength differences between PI groups. The PI was not associated with VO2max or measures of body composition. Strength and fatigue decrements strongly suggest that poor fetal growth affects the pathway of muscle force generation. This could be due to neuromotor and/or muscle morphologic changes during development e.g., fiber number, fiber type, etc. Muscle from LOWPI women may also be less responsive to training. Indirectly, results also implicate muscle as a potential mediator between poor fetal growth and adult chronic disease, given muscle’s direct role in determining insulin resistance, type II diabetes, physical activity, and so forth. PMID:21641734

  3. Age-dependent differences in microglial responses to systemic inflammation are evident as early as middle age.

    PubMed

    Nikodemova, Maria; Small, Alissa L; Kimyon, Rebecca S; Watters, Jyoti J

    2016-05-01

    Whereas age increases microglial inflammatory activities and impairs their ability to effectively regulate their immune response, it is unclear at what age these exaggerated responses begin. We tested the hypotheses that augmented microglial responses to inflammatory challenge are present as early as middle age and that repeated stimulation of primed microglia in vivo would reveal microglial senescence. Microglial gene expression was investigated in a mouse model of repeated systemic inflammation induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). Following LPS, microglia from middle-aged mice (9-10 mo) displayed larger increases in Tnfα, Il-6, and Il-1β gene expression compared with young adults (2 mo). Similar results were observed in the spleens of middle-aged mice, indicating that exaggeration of both central and peripheral immune responses are already evident at early middle age. Interestingly, despite greater proinflammatory responses to the first LPS challenge in the aged mice, there were no age-dependent differences in either microglia or spleen following a subsequent LPS dose, suggesting that animals at this age retain the ability to effectively control their immune response following repeated challenge. The exacerbated microglial immune response to systemic inflammation at early middle age suggests that the CNS may be vulnerable to age-dependent alterations earlier than previously appreciated. Copyright © 2016 the American Physiological Society.

  4. Effects of prolonged and maintenance strength training on force production, walking, and balance in aging women and men.

    PubMed

    Holviala, J; Häkkinen, A; Alen, M; Sallinen, J; Kraemer, W; Häkkinen, K

    2014-02-01

    To examine effects of 21-week twice/week strength training (ST) period followed by an additional 21-week twice or once/week ST period on force production, walking and balance in aging people. Seventy-two women (58 ± 7 years; W) and 63 (58 ± 6 years) men (M) were randomized for the first 21-week ST period: STW and STM, control (C) CW and CM. Training participants were randomized for the second 21-week ST period: once/week STWx1 and STMx1, twice/week STWx2 and STMx2. LegPress, isometric leg extension rate of force development (RFD), walking time, and balance. First 21-week ST period: leg press, RFD, balance, and walking improved significantly in STW and STM. Second 21-week ST period: leg press first increased in STMx1 and STMx2, and then decreased to the level of 21 weeks in STMx2 and remained unchanged in STWx2 and decreased in STWx1 and STMx1. Walking and balance improved significantly in STWx1 and STWx2. A progressive 21-week ST period twice/week in aging people can lead to large improvements in maximal strength, walking time, and balance in both genders. A further strength training period with the same amount of training may maintain the strength gains, whereas balance and walking may be maintained with less training.

  5. Effects of Age and Military Service on Strength and Physiological Characteristics of U.S. Army Soldiers.

    PubMed

    Abt, John P; Perlsweig, Katherine; Nagai, Takashi; Sell, Timothy C; Wirt, Michael D; Lephart, Scott M

    2016-02-01

    Soldiers must maintain tactical performance capabilities over the course of their career. Loss in physical readiness may be a function of age and the operational demands associated with increasing years of service. The purpose of this study was to assess strength and physiological characteristics in different cohorts of U.S. Army Soldiers based on years of service and age. A total of 253 Soldiers (age: 28.1 ± 6.8 years; height: 1.76 ± 0.11 m; mass: 84.1 ± 12.2 kg) participated. Individual subject cohorts were created based on years of service (1-5 years, 6-10 years, 11-15 years) and age (20-24 years, 25-29 years, 30-34 years, 35-39 years, 40-44 years). Testing included shoulder, knee, ankle, and torso strength, aerobic capacity/lactate threshold, anaerobic power/capacity, and body composition/total mass. Those with 11 to 15 years of service and between ages 30 and 34 had a higher percentage of body fat, and lower aerobic capacity and lactate threshold than younger Soldiers with fewer years of service. Physical training interventions should focus on maintenance of physiological characteristics to offset the loss of readiness at the similar time point of 11 to 15 years of service and 30 to 34 years of age.

  6. Microarray Analysis of Genes Involved with Shell Strength in Layer Shell Gland at the Early Stage of Active Calcification

    PubMed Central

    Liu, Zhangguo; Zheng, Qi; Zhang, Xueyu; Lu, Lizhi

    2013-01-01

    The objective of this study was to get a comprehensive understanding of how genes in chicken shell gland modulate eggshell strength at the early stage of active calcification. Four 32-week old of purebred Xianju hens with consistent high or low shell breakage strength were grouped into two pairs. Using Affymetrix Chicken Array, a whole-transcriptome analysis was performed on hen’s shell gland at 9 h post oviposition. Gene ontology enrichment analysis for differentially expressed (DE) transcripts was performed using the web-based GOEAST, and the validation of DE-transcripts was tested by qRT-PCR. 1,195 DE-transcripts, corresponding to 941 unique genes were identified in hens with strong eggshell compared to weak shell hens. According to gene ontology annotations, there are 77 DE-transcripts encoding ion transporters and secreted extracellular matrix proteins, and at least 26 DE-transcripts related to carbohydrate metabolism or post-translation glycosylation modification; furthermore, there are 88 signaling DE-transcripts. GO term enrichment analysis suggests that some DE-transcripts mediate reproductive hormones or neurotransmitters to affect eggshell quality through a complex suite of biophysical processes. These results reveal some candidate genes involved with eggshell strength at the early stage of active calcification which may facilitate our understanding of regulating mechanisms of eggshell quality. PMID:25049830

  7. Early Intervention Evaluation Reports: Guidelines for Writing User-Friendly and Strength-Based Assessments

    ERIC Educational Resources Information Center

    Towle, Patricia; Farrell, Anne F.; Vitalone-Raccaro, Nancy

    2008-01-01

    Assessment and evaluation activities are an integral part of early intervention services. These activities culminate in written evaluation reports that include information such as observations of skills and deficits, diagnosis, and recommendations for intervention. However, few guidelines exist to help guide early intervention providers in writing…

  8. Strengths and Weaknesses of Sea Ice as a Potential Early Indicator of Climate Change,

    DTIC Science & Technology

    Sea ice is examined for its potential as an early indicator of climate change by considering how well it satisfies four criteria listed as desired... climate change , sea ice is unlikely any time in the near future to be a definitive early indicator of climate change when considered by itself.

  9. Dietary habits of Mongolian people, and their influence on lifestyle-related diseases and early aging.

    PubMed

    Komatsu, Fumio; Kagawa, Yasuo; Kawabata, Terue; Kaneko, Yoshinori; Purvee, Baatar; Otgon, Jugder; Chimedregzen, Ulziiburen

    2008-07-01

    Mongolians are known to have relatively short life expectancy. In order to examine the role of dietary habits in the early aging of Mongolians, the food intake inquiry, anthropometric measurements and blood clinical tests were performed for 365 healthy inhabitants in Murun, a northern Mongolia city, and compared to those of Japanese. Murun inhibitants were found to have a characteristic dietary habit of taking large amounts of meat, milk, dairy products and wheat flour products, in contrast little vegetables, fruits and fishes. The daily calorie intake of the adults was estimated to be 2,525 kcal, and the fat/total calorie ratio was calculated 33.7%, about 1.3-fold higher than that of Japanese. The intake ratio of fatty acid from the Mongolian foods, saturated : mono-unsaturated : poly-unsaturated fatty acids (PUFA) ratio, was 10.3 : 7.8 : 3.0. Results of blood clinical tests showed significantly higher levels of serum triglycerides, low-density lipoprotein cholesterol (LDL) and homocysteine, and lower levels of high-density lipoprotein cholesterol (HDL), n-3 PUFA, folic acid and adiponectin, in comparison with those of Japanese. In addition, the Mongolians were also found to have significantly high levels of oxidative stress markers, such as serum malondialdehyde-modified LDL (MDA-LDL), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and serum reactive oxygen metabolites (ROM). The serum ROM level in the Mongolians seemed to associate with their body fat ratio (p<0.05), and was significantly inverse-correlated to handgrip strength (p<0.001). Obesity was observed at a high incidence in the subjects over 30-year old, and over 40-year old their handgrip ability was markedly decreased. These findings suggest that in the Mongolians the dietary habits associate with their lifestyle-related diseases and early aging, and the improvement of dietary habits is an effective strategy for health promotion of the inhabitants.

  10. Early Adolescent Perceptions of Neighborhood: Strengths, Structural Disadvantage, and Relations to Outcomes

    ERIC Educational Resources Information Center

    Witherspoon, Dawn P.; Hughes, Diane L.

    2014-01-01

    Considerable evidence shows the detriments of neighborhood social disorganization for urban youth. Researchers have focused less on potential neighborhood strengths or on the interplay of neighborhood perceptions and objective neighborhood characteristics. The authors examined the presence and perception of positive and negative neighborhood…

  11. Age 26 Cost-Benefit Analysis of the Child-Parent Center Early Education Program

    ERIC Educational Resources Information Center

    Reynolds, Arthur J.; Temple, Judy A.; White, Barry A. B.; Ou, Suh-Ruu; Robertson, Dylan L.

    2011-01-01

    Using data collected up to age 26 in the Chicago Longitudinal Study, this cost-benefit analysis of the Child-Parent Centers (CPC) is the first for a sustained publicly funded early intervention. The program provides services for low-income families beginning at age 3 in 20 school sites. Kindergarten and school-age services are provided up to age 9…

  12. Age 26 Cost-Benefit Analysis of the Child-Parent Center Early Education Program

    ERIC Educational Resources Information Center

    Reynolds, Arthur J.; Temple, Judy A.; White, Barry A. B.; Ou, Suh-Ruu; Robertson, Dylan L.

    2011-01-01

    Using data collected up to age 26 in the Chicago Longitudinal Study, this cost-benefit analysis of the Child-Parent Centers (CPC) is the first for a sustained publicly funded early intervention. The program provides services for low-income families beginning at age 3 in 20 school sites. Kindergarten and school-age services are provided up to age 9…

  13. Burst strength behaviour of an aging subsea gas pipeline elbow in different external and internal corrosion-damaged positions

    NASA Astrophysics Data System (ADS)

    Lee, Geon Ho; Pouraria, Hassan; Seo, Jung Kwan; Paik, Jeom Kee

    2015-09-01

    Evaluation of the performance of aging structures is essential in the oil and gas industry, where the inaccurate prediction of structural performance can have significantly hazardous consequences. The effects of structure failure due to the significant reduction in wall thickness, which determines the burst strength, make it very complicated for pipeline operators to maintain pipeline serviceability. In other words, the serviceability of gas pipelines and elbows needs to be predicted and assessed to ensure that the burst or collapse strength capacities of the structures remain less than the maximum allowable operation pressure. In this study, several positions of the corrosion in a subsea elbow made of API X42 steel were evaluated using both design formulas and numerical analysis. The most hazardous corrosion position of the aging elbow was then determined to assess its serviceability. The results of this study are applicable to the operational and elbow serviceability needs of subsea pipelines and can help predict more accurate replacement or repair times.

  14. Burst strength behaviour of an aging subsea gas pipeline elbow in different external and internal corrosion-damaged positions

    NASA Astrophysics Data System (ADS)

    Lee, Geon Ho; Pouraria, Hassan; Seo, Jung Kwan; Paik, Jeom Kee

    2015-05-01

    Evaluation of the performance of aging structures is essential in the oil and gas industry, where the inaccurate prediction of structural performance can have significantly hazardous consequences. The effects of structure failure due to the significant reduction in wall thickness, which determines the burst strength, make it very complicated for pipeline operators to maintain pipeline serviceability. In other words, the serviceability of gas pipelines and elbows needs to be predicted and assessed to ensure that the burst or collapse strength capacities of the structures remain less than the maximum allowable operation pressure. In this study, several positions of the corrosion in a subsea elbow made of API X42 steel were evaluated using both design formulas and numerical analysis. The most hazardous corrosion position of the aging elbow was then determined to assess its serviceability. The results of this study are applicable to the operational and elbow serviceability needs of subsea pipelines and can help predict more accurate replacement or repair times.

  15. Effects of aging on P300 between late young-age and early middle-age adulthood: an electroencephalogram event-related potential study.

    PubMed

    Bourisly, Ali K

    2016-09-28

    The aim of this study was to identify age-related changes of P300 peak amplitude and P300 latency between closely separated nonsenile age groups (late young-aged adults and early middle-aged adults) and to investigate whether or not P300 has the potential to be used as a measure of cognitive aging even among nonsenile age groups. Twenty-eight adults (25-55 years old) completed an event-related potential oddball task. The elicitation of both P300 peak amplitude and P300 latency indicated age-related changes of P300. The results of the study showed that the P300 target peak amplitude was significantly larger in late young age compared with early middle age and that P300 target latency was also significantly delayed in early middle age compared with late young age. The results of this work contribute toward research efforts on a consensus on how aging affects event-related potential and/or P300. The main conclusions are that there exist significant age-related P300 changes even between closely separated, relatively younger, and nonsenile age groups, and that P300 has the potential to be used as a measure for cognitive aging even in nonsenile adults.

  16. Rapamycin increases grip strength and attenuates age-related decline in maximal running distance in old low capacity runner rats.

    PubMed

    Xue, Qian-Li; Yang, Huanle; Li, Hui-Fen; Abadir, Peter M; Burks, Tyesha N; Koch, Lauren G; Britton, Steven L; Carlson, Joshua; Chen, Laura; Walston, Jeremy D; Leng, Sean X

    2016-04-01

    Rapamycin is known to extend lifespan. We conducted a randomized placebo-controlled study of enteric rapamycin-treatment to evaluate its effect on physical function in old low capacity runner (LCR) rats, a rat model selected from diverse genetic background for low intrinsic aerobic exercise capacity without genomic manipulation and characterized by increased complex disease risks and aging phenotypes. The study was performed in 12 male and 16 female LCR rats aged 16-22 months at baseline. The treatment group was fed with rapamycin-containing diet pellets at approximately 2.24mg/kg body weight per day and the placebo group with the same diet without rapamycin for six months. Observation was extended for additional 2 months. Physical function measurements include grip strength measured as maximum tensile force using a rat grip strength meter and maximum running distance (MRD) using rat physical treadmill test. The results showed that rapamycin improved grip strength by 13% (p=.036) and 60% (p=.001) from its baseline in female and male rats, respectively. Rapamycin attenuated MRD decline by 66% (p=.001) and 46% (p=.319) in females and males, respectively. These findings provide initial evidence for beneficial effect of rapamycin on physical functioning in an aging rat model of high disease risks with significant implication in humans.

  17. Effect of early age woody and herbaceous competition control on wood properties of loblolly pine

    Treesearch

    F. Antony; L. R. Schimleck; L. Jordan; Alexander Clark; R. F. Daniels

    2011-01-01

    Early age competition control has been reported to significantly improve the growth and yield of plantation grown loblolly pine. The objective of this paper is to understand the changes in wood properties: basal area weighted whole disk SG, earlywood SG (EWSG), latewood SG (LWSG) and latewood percent (LWP) of 14 year-old trees which received early age herbaceous and...

  18. Achieving High Energy Density in PVDF-Based Polymer Blends: Suppression of Early Polarization Saturation and Enhancement of Breakdown Strength.

    PubMed

    Zhang, Xin; Shen, Yang; Shen, Zhonghui; Jiang, Jianyong; Chen, Longqing; Nan, Ce-Wen

    2016-10-03

    Polymers with high dielectric strength and favorable flexibility have been considered promising materials for dielectrics and energy storage applications, while the achievable energy density (Ue) of polymer is rather limited by the intrinsic low dielectric constant and ferroelectric hysteresis. Polyvinylidene fluoride-trifluoroethylene-chlorofluoroethylene (P(VDF-TrFE-CFE)) with ultrahigh εr of >50 is considered promising in achieving high Ue of polymer dielectrics. However, P(VDF-TrFE-CFE) only exhibits moderate Ue due to the early saturation of electrical polarization at low electric field. In this contribution, we show that, by blending P(VDF-TrFE-CFE) with polyvinylidene fluoride (PVDF), the early saturation of P(VDF-TrFE-CFE) is substantially suppressed, giving rise to concomitant enhancement of dielectric permittivity and breakdown strength. An ultrahigh energy density of 19.6 J/cm(3) is thus achieved at ∼640 kV/mm, which is 1600% greater than Ue of the benchmark biaxially oriented polypropylene (BOPP, 1.2 J/cm(3) at 640 kV/mm). Results of phase field simulations reveal that the interfaces between PVDF and P(VDF-TrFE-CFE) play a critical role by not only suppressing early saturation of electrical polarization in P(VDF-TrFE-CFE) but also inducing additional interfacial polarization. Binary phase diagram of P(VDF-TrFE-CFE)/PVDF blends is also systematically explored with their dielectric and energy storage behavior studied.

  19. Combined strength and endurance training improves health-related quality of life in healthy middle-aged and older adults.

    PubMed

    Sillanpää, E; Häkkinen, K; Holviala, J; Häkkinen, A

    2012-12-01

    The purpose of this study was to evaluate the effects of 21 weeks of strength and/or endurance training on health related quality of life (HRQoL) in 39-77 year-old healthy subjects. 108 men and 96 women were randomized into endurance, strength, or combined training groups and controls. Strength-group performed high-intensity strength training while endurance-group performed cycle training. Combined-group completed both training protocols. Leg extension strength and maximal oxygen uptake were measured. HRQoL was assessed with a Finnish version of SF-36 questionnaire. A significant training-induced difference was observed between groups (p=0.038) in the vitality dimension of HRQoL, which was characterized by a 6.6 ± 1.5 unit increase in the combined group and no change in the other groups. Both endurance and combined training showed small improvements in certain dimensions of HRQoL. Dimensions of general (4.6 ± 1.9) and mental health (3.9 ± 1.4) improved in combined-group while general health (4.4 ± 2.0), bodily pain (5.5 ± 2.5) and role physical (6.0 ± 2.4) improved in endurance-group. Strength-group experienced increased pain ( -5.4 ± 1.8) during the experimental period. However, increased perception of pain was not observed during combined training. According to the present results both endurance and especially combined training may have potential to promote or maintain certain dimensions of HRQoL even in middle-aged and older adults. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Effects of strength training and reduced training on functional performance and metabolic health indicators in middle-aged men.

    PubMed

    Sallinen, J; Fogelholm, M; Volek, J S; Kraemer, W J; Alen, M; Häkkinen, K

    2007-10-01

    Changes in muscular fitness and metabolic health indicators were examined in 22 men (57.9 +/- 6.6 years, BMI 24.5 +/- 2.6 kg/m (2)) and 21 control men (58.2 +/- 6.1 years, BMI 25.4 +/- 2.8 kg/m (2)) during two consecutive 21-week periods: 1) whole body progressive strength training (ST: twice a week), and 2) continued reduced training (CRT: 3 ST sessions/2 weeks, n = 17 + 17). After the 21-week ST period, maximal strength of leg extensors increased in the ST group by 19.6 +/- 7.6 % vs. 2.8 +/- 4.4 % (p < 0.001) and also 10-m walking time and 10-step stair-climbing time shortened by - 17.2 +/- 7.6 % vs. 4.1 +/- 3.9 % (p < 0.01) and by - 8.2 +/- 6.8 % vs. - 3.0 +/- 6.8 % (p < 0.05) compared to the controls. Systolic blood pressure (BP) decreased in the ST group by - 4.4 +/- 6.7 % vs. 1.3 +/- 9.5 % (p < 0.05) compared to the controls after the ST period. Muscle strength as well as walking and stair-climbing times remained the same during the CRT. However, the changes in diastolic BP (- 8.9 +/- 8.7 % vs. - 1.0 +/- 6.6 %, p < 0.05) and fasting blood glucose concentrations (0.1 +/- 0.4 mmol/L vs. 0.3 +/- 0.4 mmol/L, p < 0.05) differed between the ST and control groups after the whole 42-week study period. Strength training has positive health effects in aging men by increasing maximal strength and functional performance and by decreasing resting blood pressure and high-intensity reduced strength training can maintain these health benefits.

  1. Early Life Origins of Lung Ageing: Early Life Exposures and Lung Function Decline in Adulthood in Two European Cohorts Aged 28-73 Years

    PubMed Central

    Dratva, Julia; Zemp, Elisabeth; Dharmage, Shyamali C.; Accordini, Simone; Burdet, Luc; Gislason, Thorarinn; Heinrich, Joachim; Janson, Christer; Jarvis, Deborah; de Marco, Roberto; Norbäck, Dan; Pons, Marco; Real, Francisco Gómez; Sunyer, Jordi; Villani, Simona; Probst-Hensch, Nicole; Svanes, Cecilie

    2016-01-01

    Objectives Early life environment is essential for lung growth and maximally attained lung function. Whether early life exposures impact on lung function decline in adulthood, an indicator of lung ageing, has scarcely been studied. Methods Spirometry data from two time points (follow-up time 9–11 years) and information on early life exposures, health and life-style were available from 12862 persons aged 28–73 years participating in the European population-based cohorts SAPALDIA (n = 5705) and ECRHS (n = 7157). The associations of early life exposures with lung function (FEV1) decline were analysed using mixed-effects linear regression. Results Early life exposures were significantly associated with FEV1 decline, with estimates almost as large as personal smoking. FEV1 declined more rapidly among subjects born during the winter season (adjusted difference in FEV1/year of follow-up [95%CI] -2.04ml [-3.29;-0.80]), of older mothers, (-1.82 ml [-3.14;-0.49]) of smoking mothers (-1.82ml [-3.30;-0.34] or with younger siblings (-2.61ml [-3.85;-1.38]). Less rapid FEV1-decline was found in subjects who had attended daycare (3.98ml [2.78;5.18]), and indicated in subjects with pets in childhood (0.97ml [-0.16;2.09]). High maternal age and maternal smoking appeared to potentiate effects of personal smoking. The effects were independent of asthma at any age. Conclusion Early life factors predicted lung function decline decades later, suggesting that some mechanisms related lung ageing may be established early in life. Early life programming of susceptibility to adult insults could be a possible pathway that should be explored further. PMID:26811913

  2. Early Life Origins of Lung Ageing: Early Life Exposures and Lung Function Decline in Adulthood in Two European Cohorts Aged 28-73 Years.

    PubMed

    Dratva, Julia; Zemp, Elisabeth; Dharmage, Shyamali C; Accordini, Simone; Burdet, Luc; Gislason, Thorarinn; Heinrich, Joachim; Janson, Christer; Jarvis, Deborah; de Marco, Roberto; Norbäck, Dan; Pons, Marco; Real, Francisco Gómez; Sunyer, Jordi; Villani, Simona; Probst-Hensch, Nicole; Svanes, Cecilie

    2016-01-01

    Early life environment is essential for lung growth and maximally attained lung function. Whether early life exposures impact on lung function decline in adulthood, an indicator of lung ageing, has scarcely been studied. Spirometry data from two time points (follow-up time 9-11 years) and information on early life exposures, health and life-style were available from 12862 persons aged 28-73 years participating in the European population-based cohorts SAPALDIA (n = 5705) and ECRHS (n = 7157). The associations of early life exposures with lung function (FEV1) decline were analysed using mixed-effects linear regression. Early life exposures were significantly associated with FEV1 decline, with estimates almost as large as personal smoking. FEV1 declined more rapidly among subjects born during the winter season (adjusted difference in FEV1/year of follow-up [95%CI] -2.04ml [-3.29;-0.80]), of older mothers, (-1.82 ml [-3.14;-0.49]) of smoking mothers (-1.82ml [-3.30;-0.34] or with younger siblings (-2.61ml [-3.85;-1.38]). Less rapid FEV1-decline was found in subjects who had attended daycare (3.98ml [2.78;5.18]), and indicated in subjects with pets in childhood (0.97ml [-0.16;2.09]). High maternal age and maternal smoking appeared to potentiate effects of personal smoking. The effects were independent of asthma at any age. Early life factors predicted lung function decline decades later, suggesting that some mechanisms related lung ageing may be established early in life. Early life programming of susceptibility to adult insults could be a possible pathway that should be explored further.

  3. Gestational age-dependent risk factors for preterm birth: associations with maternal education and age early in gestation.

    PubMed

    Auger, Nathalie; Abrahamowicz, Michal; Wynant, Willy; Lo, Ernest

    2014-05-01

    Preterm birth (PTB) before 37 weeks can occur over a wide range of gestational ages, but few studies have assessed if associations between risk factors and PTB vary over the duration of gestation. We sought to evaluate if associations between two major risk factors (maternal education and age) and PTB depend on gestational age at delivery. We estimated hazard ratios of PTB for education and age in a time-to-event analysis using a retrospective cohort of 223,756 live singleton births from the province of Québec, Canada for the years 2001-2005. Differences in hazards of maternal education and age with PTB were assessed over gestational age in a Cox proportional hazards model using linear and nonlinear time interaction terms, adjusting for maternal characteristics. Associations of PTB with lower (vs. higher) education and older (vs. younger) age strengthened progressively at earlier gestational ages, such that the risk of PTB for maternal education and age was not constant over the course of gestation. Associations of PTB with risk factors such as maternal low education and older age may be stronger early in gestation. Models that capture the time-dependent nature of PTB may be useful when the goal is to assess associations at low gestational ages, and to avoid masked or biased associations early in gestation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Long lasting blindness, availability of resources, and early aging.

    PubMed

    Bachar, E; Shanan, J

    1997-04-01

    The present paper studied the influence of long lasting blindness on processes of aging. It addressed the broader issue of the effects of familiarity with and earlier experience of stress on the capacity of individuals to deal successfully with similar stressful situations at a later point of development. 75 chronically blind men and women, aged 45 to 65, were compared with 75 sighted individuals (matched by age, sex, and cultural origin) on scores on the Shanan Sentence Completion Technique, an interview designed to assess perception of change in various areas of everyday living, and on scores on the Wechsler-Bellevue Intelligence Test. Blind subjects showed less psychological and less social engagement with the outer world. Availability of resources, education, and assistance considerably reduced differences between the nonsighted and sighted subjects. These findings were interpreted as pointing to a potentially preventable process of premature aging.

  5. Telomeres, Reproductive Aging, and Genomic Instability During Early Development.

    PubMed

    Keefe, David L

    2016-12-01

    Implantation rate decreases and miscarriage rate increases with advancing maternal age. The oocyte must be the locus of reproductive aging because donation of oocytes from younger to older women abrogates the effects of aging on fecundity. Nuclear transfer experiments in a mouse model of reproductive aging show that the reproductive aging phenotype segregates with the nucleus rather than the cytoplasm. A number of factors within the nucleus have been hypothesized to mediate reproductive aging, including disruption of cohesions, reduced chiasma, aneuploidy, disrupted meiotic spindles, and DNA damage caused by chronic exposure to reactive oxygen species. We have proposed telomere attrition as a parsimonious way to explain these diverse effects of aging on oocyte function. Telomeres are repetitive sequences of DNA and associated proteins, which form a loop (t loop) at chromosome ends. Telomeres prevent the blunt end of DNA from triggering a DNA damage response. Previously, we showed that experimental telomere shortening phenocopies reproductive aging in mice. Telomere shortening causes reduced synapsis and chiasma, chromosome fusions, embryo arrest and fragmentation, and abnormal meiotic spindles. Telomere length of polar bodies predicts the fragmentation of human embryos. Telomerase, the reverse transcriptase capable of reconstituting shortened telomeres, is only minimally active in oocytes and preimplantation embryos. Intriguingly, during the first cell cycles following activation, telomeres robustly elongate via a DNA double-strand break mechanism called alternative lengthening of telomeres (ALTs). Alternative lengthening of telomere takes place even in telomerase-null mice. This mechanism of telomere elongation previously had been found only in cancer cells lacking telomerase activity. We propose that ALT elongates telomeres across generations but does so at the cost of extensive genomic instability in preimplantation embryos. © The Author(s) 2016.

  6. Effect of vitamin D nutritional status on muscle function and strength in healthy women aged over sixty-five years.

    PubMed

    Mastaglia, S R; Seijo, M; Muzio, D; Somoza, J; Nuñez, M; Oliveri, B

    2011-05-01

    Vitamin D insufficiency is common in elderly adults, and leads to secondary hyperparathyroidism, bone loss, muscle weakness, and osteoporotic fractures. To evaluate the relation between vitamin D nutritional status and muscle function and muscle strength in women aged over 65 years. Fifty-four postmenopausal women from Buenos Aires (latitude 34° S), average age (X±DS) 71±4, were included in the study. Determinations of serum calcium, phosphate, 25 hydroxyvitamin D (25OHD), intact parathormone (iPTH) and calciuria / creatininuria ratio in 24-hour urine samples were performed. Muscle function was assessed by means of walking-speed test, standing balance, and sit-to-stand tests. Lower extremity muscle strength was determined using a manual dynamometer. 25OHD levels ≥20 ng/ml were found to be associated with better lower extremity muscle function and strength. Forty- six % of participants had 25OHD levels ≥20 ng/ml. Women with 25OHD levels ≥20 ng/ml scored higher on the muscle function tests (11.2±0.9 vs.10.0±2.1; p<0.003) and had stronger knee extensor (13.4±2.7 vs.11.6±2.5 Kg.; p<0.03) and hip abductor (8.3±2.7 vs. 7.3±3.1 Kg; p<0.04) muscles; strength of their hip flexors tended to be higher but did not reach significantly different values (17.0±3.3 vs. 15.4±2.8 Kg.; 0.1>p>0.05). Negative correlation was observed between iPTH and muscle function (r= -0.436; p<0.02). 25OHD levels ≥20 ng/ml are needed for a better muscle function and strength. Assessing vitamin D nutritional status in adults aged ≥ 65 years would allow correcting hypovitaminosis D and improve muscle function and strength.

  7. The developmental progression of age 14 behavioral disinhibition, early age of sexual initiation, and subsequent sexual risk-taking behavior.

    PubMed

    Samek, Diana R; Iacono, William G; Keyes, Margaret A; Epstein, Marina; Bornovalova, Marina A; McGue, Matt

    2014-07-01

    Research has demonstrated a consistent relationship between early sexual experience and subsequent sexual risk-taking behaviors. We hypothesized that this relationship is due to a general predisposition toward behavioral disinhibition (BD), and that relationships among BD, early sex, and subsequent risky sexual behavior may be influenced by common genetic influences for males and common environmental influences for females. A prospective sample of 1,512 same-sex adolescent twins (50.2% female) was used. Adolescent BD was measured by clinical symptom counts of conduct disorder, oppositional defiant disorder, and self-reported delinquent behavior (age 14). Age of sexual initiation was defined as first age of consensual oral or penetrative sex (mean age ~17). Adult risky sexual behavior was defined by sexual behaviors under the influence of drugs and alcohol and number of casual sexual partners in the past year (age 24). Multivariate analyses showed evidence for substantial common genetic variance among age 14 BD, age at sexual initiation, and adult risky sexual behavior for males, but not females. There was no significant difference in the degree of common environmental influence on these variables for females compared to males. Notably, age of sexual initiation was not significantly correlated with age 24 risky sexual behavior for females. The relationship between early sex and later risky sex can be better understood through a general liability toward BD, which is influenced primarily by genetic factors for males. The association between age 14 BD and age of sexual initiation was influenced through a combination of genetic and environmental factors for females; however, age of sexual initiation does not appear to be a salient predictor of adult women’s sexual risk-taking behavior. Findings suggest that prevention programs aimed at reducing sexual risk behavior might target youth exhibiting BD by age 14, particularly males. More research is needed on what predicts

  8. The Developmental Progression of Age 14 Behavioral Disinhibition, Early Age of Sexual Initiation, and Subsequent Sexual Risk-Taking Behavior

    PubMed Central

    Samek, Diana R.; Iacono, William G.; Keyes, Margaret A.; Epstein, Marina; Bornovalova, Marina A.; McGue, Matt

    2013-01-01

    Background Research has demonstrated a consistent relationship between early sexual experience and subsequent sexual risk-taking behaviors. We hypothesized that this relationship is due to a general predisposition towards behavioral disinhibition (BD), and that relationships among BD, early sex, and subsequent risky sexual behavior may be influenced by common genetic influences for males and common environmental influences for females. Methods A prospective sample of 1,512 same-sex adolescent twins (50.2% female) was used. Adolescent BD was measured by clinical symptom counts of conduct disorder, oppositional defiant disorder, and self-reported delinquent behavior (age 14). Age of sexual initiation was defined as first age of consensual oral or penetrative sex (mean age ~17). Adult risky sexual behavior was defined by sexual behaviors under the influence of drugs and alcohol and number of casual sexual partners in the past year (age 24). Results Multivariate analyses showed evidence for substantial common genetic variance among age 14 BD, age at sexual initiation, and adult risky sexual behavior for males, but not females. There was no significant difference in the degree of common environmental influence on these variables for females compared to males. Notably, age of sexual initiation was not significantly correlated with age 24 risky sexual behavior for females. Conclusion The relationship between early sex and later risky sex can be better understood through a general liability towards BD, which is influenced primarily by genetic factors for males. The association between age 14 BD and age of sexual initiation was influenced through a combination of genetic and environmental factors for females; however, age of sexual initiation does not appear to be a salient predictor of adult women’s sexual risk-taking behavior. Findings suggest that prevention programs aimed at reducing sexual risk behavior might target youth exhibiting BD by age 14, particularly males

  9. Overweight and obesity in young and middle age and early retirement: the ARIC study.

    PubMed

    Houston, Denise K; Cai, Jianwen; Stevens, June

    2009-01-01

    The objective of this study was to examine associations between weight status in young and middle age and early retirement in African-American and white men and women. Data were from the Atherosclerosis Risk in Communities (ARIC) study. Analyses were restricted to participants aged 45-55 years at baseline (n = 6,483). Associations between weight status at age 25 and ages 45-55 and age at early retirement (prior to age 65) over 9 years of follow-up were examined using proportional hazard regression analyses in models stratified by race and gender. Models were adjusted for education, household income, health insurance status, occupation, occupational physical activity, marital status, smoking, and field center. Between 18.7 and 21.6% of African-American and white men and women reported retiring prior to age 65. Although not always statistically significant, overweight and obesity were associated with early retirement in all but white women. Overweight (BMI >or= 25 kg/m(2)) at age 25 was significantly associated with early retirement in African-American women (hazard ratio (95% confidence interval): 1.62 (1.17-2.23)) and white men (1.32 (1.12-1.57)). There was also a trend between overweight at age 25 and early retirement in African-American men (1.43 (0.99-2.07)). Obesity (BMI >or= 30 kg/m(2)) in middle age was significantly associated with early retirement in white men only (1.32 (1.03-1.69)). Furthermore, overweight at age 25 and obesity at ages 45-55 were associated with early retirement for health reasons among African-American and white men and women. In conclusion, analyses of the economic impact of obesity may need to consider its effects on early retirement.

  10. Effects of thermal aging on fracture toughness and charpy-impact strength of stainless steel pipe welds.

    SciTech Connect

    Gavenda, D. J.; Michaud, W. F.; Galvin, T. M.; Burke, W. F.; Chopra, O. K.; Energy Technology

    1996-06-05

    The degradation of fracture toughness, tensile, and Charpy-impact properties of Type 308 stainless steel (SS) pipe welds due to thermal aging has been characterized at room temperature and 290 C. Thermal aging of SS welds results in moderate decreases in Charpy-impact strength and fracture toughness. For the various welds in this study, upper-shelf energy decreased by 50-80 J/cm{sup 2}. The decrease in fracture toughness J-R curve or JIC is relatively small. Thermal aging had little or no effect on the tensile strength of the welds. Fracture properties of SS welds are controlled by the distribution and morphology of second-phase particles. Failure occurs by the formation and growth of microvoids near hard inclusions; such processes are relatively insensitive to thermal aging. The ferrite phase has little or no effect on the fracture properties of the welds. Differences in fracture resistance of the welds arise from differences in the density and size of inclusions. Mechanical-property data from the present study are consistent with results from other investigations. The existing data have been used to establish minimum expected fracture properties for SS welds.

  11. Effects of thermal aging on fracture toughness and Charpy-impact strength of stainless steel pipe welds

    SciTech Connect

    Gavenda, D.J.; Michaud, W.F.; Galvin, T.M.; Burke, W.F.; Chopra, O.K.

    1996-05-01

    Degradation of fracture toughness, tensile, and Charpy-impact properties of Type 304 and 304/308 SS pipe welds due to thermal aging was studied at room temperature and 290 C. Thermal aging of SS welds results in moderate decreases in charpy-impact strength and fracture toughness. Upper-shelf energy decreased by 50-80 J/cm{sup 2}. Decrease in fracture toughness J-R curve or J{sub IC} is relatively small. Thermal aging had no or little effect on tensile strength of the welds. Fracture properties of SS welds are controlled by the distribution and morphology of second-phase particles. Failure occurs by formation and growth of microvoids near hard inclusions; such processes are relatively insensitive to thermal aging. The ferrite phase has little or no effect on fracture properties of the welds. Differences in fracture resistance of the welds arise from differences in the density and size of inclusions. Mechanical-property data from the present study are consistent with results from other investigations. The existing data have been used to establish minimum expected fracture properties for SS welds.

  12. Age related differences of selected Hatha yoga practices on anthropometric characteristics, muscular strength and flexibility of healthy individuals

    PubMed Central

    Halder, Kaushik; Chatterjee, Abhirup; Pal, Rameshwar; Tomer, Omveer S; Saha, Mantu

    2015-01-01

    Background: Physiological benefits of yoga on volunteers of a particular age group are available. However, reports on efficacy of a specific yoga package on the populace of different age groups from similar occupational background is still very limited. Therefore, the present study was conducted to appraise the effect of a specific Hatha yoga package on anthropometric characteristics, flexibility and muscular strength of healthy individuals of different age groups from similar occupational trade. Materials and Methods: A total of 71 participants (Group All) from Indian Air Force ground personnel volunteered and age wise divided into 3 groups - (i) Group I (Gr. - I) (n1 = 27, 20-29 years), (ii) Group II (Gr. - II) (n2 = 21, 30-39 years) and (iii) Group III (Gr. - III) (n3 = 23, 40-49 years). All the participants undergone selected Hatha yoga training for 1 h daily for a period of 12 weeks. Parameters were recorded before and after the training. Pre and post training differences were assessed by Student's t-test. Results: Body weight (All, Gr. - II and Gr. - III [all P < 0.05]), body mass index (Gr. - II and Gr. - III [both P < 0.01]) and fat% (Gr. - II and III [both P < 0.05]) were decreased significantly. Neck circumference was increased significantly in Gr. - I (P < 0.05) but decreased significantly in Gr. - III (P < 0.05). Chest circumference (All (P < 0.001), in Gr. - I and II [both P < 0.05]), grip strength (All [left: P < 0.01 and right: P < 0.05], in Gr. - I [left: P < 0.05 and right: P < 0.01], in Gr. - II [right: P < 0.05] and in Gr. - III [left: P < 0.05 and right: P < 0.01]), back leg strength (group wise P < 0.001, P < 0.05, P < 0.01 and P < 0.05 respectively) and flexibility (all P < 0.001) were increased significantly. Summary and Conclusion: Hatha yoga can improve anthropometric characteristics, muscular strength and flexibility among volunteers of different age group and can also be helpful in preventing and attenuating age related deterioration of

  13. Modified forelimb grip strength test detects aging-associated physiological decline in skeletal muscle function in male mice

    PubMed Central

    Takeshita, Hikari; Yamamoto, Koichi; Nozato, Satoko; Inagaki, Tadakatsu; Tsuchimochi, Hirotsugu; Shirai, Mikiyasu; Yamamoto, Ryohei; Imaizumi, Yuki; Hongyo, Kazuhiro; Yokoyama, Serina; Takeda, Masao; Oguro, Ryosuke; Takami, Yoichi; Itoh, Norihisa; Takeya, Yasushi; Sugimoto, Ken; Fukada, So-ichiro; Rakugi, Hiromi

    2017-01-01

    The conventional forelimb grip strength test is a widely used method to assess skeletal muscle function in rodents; in this study, we modified this method to improve its variability and consistency. The modified test had lower variability among trials and days than the conventional test in young C57BL6 mice, especially by improving the variabilities in male. The modified test was more sensitive than the conventional test to detect a difference in motor function between female and male mice, or between young and old male mice. When the modified test was performed on male mice during the aging process, reduction of grip strength manifested between 18 and 24 months of age at the group level and at the individual level. The modified test was similar to the conventional test in detecting skeletal muscle dysfunction in young male dystrophic mice. Thus, the modified forelimb grip strength test, with its improved validity and reliability may be an ideal substitute for the conventional method. PMID:28176863

  14. Microtensile Bond Strength of Composite Cement to Novel CAD/CAM Materials as a Function of Surface Treatment and Aging.

    PubMed

    Lise, D P; Van Ende, A; De Munck, J; Vieira, Lcc; Baratieri, L N; Van Meerbeek, B

    To evaluate the effect of different surface treatments on the bond strength to a composite and a polymer-infiltrated ceramic CAD/CAM block after six-month artificial aging. Two types of CAD/CAM blocks (Cerasmart, GC; Enamic, Vita Zahnfabrik) were cut in slabs of 4-mm thickness, divided into six groups, and subjected to the following surface treatments: group 1: no treatment; group 2: sandblasting (SB); group 3: SB + silane (Si); group 4: SB + Si + flowable composite (see below); group 5: 5% hydrofluoric acid etching (HF) + Si; and group 6: 37% phosphoric acid etching (H3PO4) + Si. Sections of the same group were luted together (n=3: 3 sandwich specimens/group) using a dual-cure self-adhesive cement for all groups, except for the sections of group 4 that were luted using a light-curing flowable composite. After three weeks of storage in 0.5% chloramine at 37°C, the sandwich specimens were sectioned in rectangular microspecimens and trimmed at the interface to a dumbbell shape (1.1-mm diameter). One half of the specimens was subjected to a microtensile bond strength (μTBS) test, and the other half was tested after six months of water storage (aging). Data were statistically analyzed with a linear mixed-effects model for the factors surface treatment, material type, and aging, together with their first-degree interactions (α=0.05). The lowest bond strengths were obtained in the absence of any surface treatment (group 1), while the highest μTBSs were obtained when the surface was roughened by either SB or HF, this in combination with chemical adhesion through Si. Loss in bond strength was observed after six-month aging when either surface roughening or silanization, or both, were omitted. Both the composite and polymer-infiltrated ceramic CAD/CAM blocks appeared equally bonding-receptive regardless of the surface treatment used. Creating a microretentive surface by either SB or HF, followed by chemical adhesion using Si, is mandatory to maintain the bond strength

  15. Age-related trends in genetic parameters for Larix kaempferi and their implications for early selection

    PubMed Central

    2014-01-01

    Background Japanese larch (Larix kaempferi) has been introduced in China at the end of the 19th century, and as one successful exotic species, is becoming the preferred coniferous in northern China and sub-tropical alpine region. The rotation age is about 25-28 years for L. kaempferi as pulpwood in Henan province. Waiting for even one-half rotation age for final evaluation will be inefficient due to accumulated testing costs and delayed return on investment, which suggests that selection at an early age is highly desirable for L. kaempferi improvement programs in Henan province. In this study, we determined age trends of genetic parameters and evaluated early selection efficiency for L. kaempferi in Henan province to find out the appropriate trait for early selection and its selection age. Results Growth traits of 78 clones were measured periodically from age 2 to age 15 in a clonal trial of Larix kaempferi establishted at Son town, Henan Province. The genetic variation among clones, age-age correlations, and age trends in genetic parameters for growth traits were analyzed. Variant analysis revealed that tree height (HGT) and diameter at breast (DBH) were significant (1% level) among clones at every ages. The clonal repeatability of growth traits varied year-by-year, reaching the highest levels at different ages for different traits (0.77 at age 2 for HGT, 0.70 at age 5 for DBH and 0.66 from age 8 to age 10 for volume, respectively). The age-age genetic correlations ranged from 0.904 to 1.000 for HGT, and from 0943 to 1.000 for DBH. DBH at different ages was more genetically correlated to volume-15 than HGT. At the phenotypic level, HGT was always less correlated to volume-15 than DBH. With the estimates of efficiencies of early selection, the recommendation from present study was that the optimum age of early selection was age 2 for HGT and age 5 for DBH. Conclusions Our study showed that there were significant (1% level) on growth traits among clones at every

  16. Effect of different surface treatments on microtensile bond strength of two resin cements to aged simulated composite core materials.

    PubMed

    Esmaeili, Behnaz; Alaghehmand, Homayoon; Shakerian, Mohadese

    2015-01-01

    Roughening of the aged composite resin core (CRC) surface seems essential for durable adhesion. The aim of this study was to investigate the influence of various surface treatments and different resin cements on microtensile bond strength (µ TBS) between two aged core build-up composites (CBCs) and feldspathic ceramic. A total of 16 composite blocks made of two CBCs, Core.it and Build-it were randomly assigned to four surface treatment groups after water storage and thermocycling (2 weeks and 500 cycles). Experimental groups included surface roughening with air abrasion (AA), hydrofluoric acid, pumice, and laser and then were bonded to computer-aided design/computer-aided manufacturing feldspathic ceramic blocks using two resin cements, Panavia F2 (PF), and Duo-link (DL). The µ TBS was tested, and the fracture mode was assessed. The data were analyzed with multiple analysis of variance to estimate the contribution of different surface treatments, resin cements, and two aged CRCs on µ TBS. Statistical significance level was set at α < 0.05. Surface treatment and cement type significantly affected bond strength (P < 0.001) but the type of CRC did not (P = 0.468). Between roughening methods, the highest and the lowest values of µ TBS were sequentially obtained in AA and Er.YAG laser groups. The highest bond strength was in AA group cemented with PF (31.83 MPa). The most common failure mode was cohesive fracture in the cement. Different surface treatments had different effects on µ TBS of aged CRCs to feldspathic ceramics. PF was significantly better than DL.

  17. Mobility and muscle strength in male former elite endurance and power athletes aged 66-91 years.

    PubMed

    Manderoos, S; Wasenius, N; Laine, M K; Kujala, U M; Mälkiä, E; Kaprio, J; Sarna, S; Bäckmand, H M; Kettunen, J A; Heinonen, O J; Jula, A M; Aunola, S; Eriksson, J G

    2016-10-05

    The aim of this cross-sectional study was to compare mobility and muscle strength in male former elite endurance and power athletes aged 66-91 years (n = 150; 50 men in both former elite athlete groups and in their control group). Agility, dynamic balance, walking speed, chair stand, self-rated balance confidence (ABC-scale), jumping height, and handgrip strength were assessed. Former elite power athletes had better agility performance time than the controls (age- and body mass index, BMI-adjusted mean difference -3.6 s; 95% CI -6.3, -0.8). Adjustment for current leisure time physical activity (LTPA) and prevalence of diseases made this difference non-significant (P = 0.214). The subjects in the power sports group jumped higher than the men in the control group (age- and BMI-adjusted mean differences for vertical squat jump, VSJ 4.4 cm; 95% CI 2.0, 6.8; for countermovement jump, CMJ 4.0 cm; 95% CI 1.7, 6.4). Taking current LTPA and chronic diseases for adjusting process did not improve explorative power of the model. No significant differences between the groups were found in the performances evaluating dynamic balance, walking speed, chair stand, ABC-scale, or handgrip strength. In conclusion, power athletes among the aged former elite sportsmen had greater explosive force production in their lower extremities than the men in the control group.

  18. Fetal pituitary negative feedback at early gestational age.

    PubMed

    Rakover, Y; Weiner, E; Mosh, N; Shalev, E

    1999-06-01

    We describe an early prenatal diagnosis and the successful treatment of fetal Graves' disease from transplacental transfer of maternal thyroid stimulating autoantibodies (TSAb). The diagnosis of fetal thyrotoxicosis was made by umbilical cord sampling (UBS) at 20 weeks gestation, based on suppressed TSH with elevated FT4 levels. Therapy with propylthiouracil (PTU) improved fetal thyroid function tests as well as the clinical signs of fetal Graves' disease. Three more UBS were conducted before delivery indicating persisting mild fetal hyperthyroidism. Undetectable concentrations of thyrotrophin in fetal serum in the presence of markedly elevated FT4, suggests pituitary negative feedback at as early as 20 weeks gestation. Amniotic fluid thyrotrophin levels were measured at 20,24 and 26 weeks and were shown to correlate better with (elevated) maternal rather than (suppressed) fetal TSH values; therefore, we believe that amniotic fluid thyrotrophin measurement is unreliable for prediction of fetal thyroid status. Our observation is the first documentation of an intact feedback mechanism so early in fetal development and it suggests that pituitary maturation occurs earlier than previously believed.

  19. Establishment of a new pull-out strength testing method to quantify early osseointegration-An experimental pilot study.

    PubMed

    Nonhoff, J; Moest, T; Schmitt, Christian Martin; Weisel, T; Bauer, S; Schlegel, K A

    2015-12-01

    The animal study aims to evaluate a new experimental model for measuring sole the influence of the surface characteristics independent from implant macro-design on the level of osseointegration by registering the pull-out strength needed for removal of experimental devices with different surfaces from artificial defects. Seventy-two test bodies (36 with the FRIADENT(®) plus surface, 36 with the P15/HAp biofunctionalized surface) were inserted in six adult domestic pigs with artificial calvarial defects. The experimental devices were designed to fit in the defects leaving a gap between the test body and the local bone. After 21 days of healing, the animals were sacrificed and the test bodies were pulled out with a standardised reproducible pull-out device measuring the pull-out strength. The pull-out strength for both groups was compared. Twenty-one days after insertion a mean force of 412 ± 142 N for the P15/HAp group and 183 ± 105 N for the FRIADENT(®) plus group was measured for the removal of the specimens from the calvarial bone. The difference between the groups was statistically significant (p < 0.0001). The experimental set-up seems to be a suitable method when measuring the impact of implant surfaces on the early stage of osseointegration. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  20. Early-phase strength gains during traditional resistance training compared with an upper-body air-resistance training device.

    PubMed

    McGinley, Cian; Jensen, Randall L; Byrne, Ciarán A; Shafat, Amir

    2007-05-01

    The purpose of this study was to examine the early-phase adaptations of traditional dynamic constant external resistance (DCER) training vs. a portable upper-body training device (Fortex). The Fortex is a concentric training device based on air resistance. Contractions using this device are slow (1.5-3 s) and have a limited range of motion. The exercises potentially allow maximal muscle action during each contraction. Healthy, sedentary men (n = 30) were assigned to begin either 8 weeks of weight training (W, n = 12) or 8 weeks of Fortex training (F, n = 9), and were compared with a control group (C, n = 9). Exercises were chosen for the W group that would train similar muscle groups and contain a similar volume of repetitions as the F group. However, movement patterns and force curves were not identical. Increases in the upper-arm cross-sectional area were not detected in any of the groups. Both training groups showed strength gains in the various strength tests that were distinct from each other. Our results indicate that both Fortex and DCER training proved effective in eliciting strength gains in sedentary men over an 8-week training period. There are, however, limitations with the Fortex in terms of progression needs and training asymmetry that indicate it should be used as a complement to other training.

  1. "En Confianza": Co-Constructing Professional Strength and Voice with Latina Early Childhood Educators

    ERIC Educational Resources Information Center

    Ordonez-Jasis, Rosario; Flores, Susana Y.; Jasis, Pablo M.

    2010-01-01

    It is well documented in the literature that early pre-K reading experiences prepare children for the benefits of formal literacy instruction in the later grades. This is particularly true for young children from nonmainstream backgrounds. The objective of this article is to share the findings of a 4-year qualitative study investigating the…

  2. Strength of the spontaneously emitted collective aperiodic magnetic field fluctuations in the reionized early intergalactic medium

    SciTech Connect

    Schlickeiser, R.; Felten, T. E-mail: tim.felten@rub.de

    2013-11-20

    Nonmagnetized, fully ionized plasmas spontaneously emit aperiodic turbulent magnetic field fluctuations. Its fluctuation intensities are dominated by the contribution from a recently discovered collective, damped mode, which modifies the earlier estimate of the total magnetic field strength in a thermal nonrelativistic electron-proton plasma to |δB|=24β{sub e}{sup 1/4}(gn{sub e}m{sub e}c{sup 2}){sup 1/2} G, where g denotes the plasma parameter and β {sub e} the thermal electron velocity in units of the speed of light, in the case of no collisional damping. Accounting for simultaneous viscous damping reduces the estimate to |δB|{sub eq} = 2305g(n{sub e}m{sub e}c {sup 2}){sup 1/2} G, depending only on the plasma parameter g and the electron density n{sub e} . For the unmagnetized intergalactic medium, immediately after the reionization onset the field strengths from this mechanism are about 6.8 × 10{sup –13} G for no collisional damping and 1.5 × 10{sup –16} G for viscous damping. Maximum spatial scales of 10{sup 15} cm of the emitted aperiodic fluctuations in cosmic voids are possible.

  3. Exploring Work and Development Options to Reduce Early Labour Force Exit of Mature Aged Australians

    ERIC Educational Resources Information Center

    Pillay, Hitendra; Kelly, Kathy; Tones, Megan

    2008-01-01

    Early labour force exit is a significant challenge associated with the ageing workforce in Australia and many other developed countries. A reduction and increased flexibility of work hours has been suggested to improve labour force participation of the mature aged cohort. However, little is known about mature aged workers' aspirations for…

  4. Exploring Work and Development Options to Reduce Early Labour Force Exit of Mature Aged Australians

    ERIC Educational Resources Information Center

    Pillay, Hitendra; Kelly, Kathy; Tones, Megan

    2008-01-01

    Early labour force exit is a significant challenge associated with the ageing workforce in Australia and many other developed countries. A reduction and increased flexibility of work hours has been suggested to improve labour force participation of the mature aged cohort. However, little is known about mature aged workers' aspirations for…

  5. Early Onset Ageing and Service Preparation in People with Intellectual Disabilities: Institutional Managers' Perspective

    ERIC Educational Resources Information Center

    Lin, Jin-Ding; Wu, Chia-Ling; Lin, Pei-Ying; Lin, Lan-Ping; Chu, Cordia M.

    2011-01-01

    Although longevity among older adults with intellectual disabilities is increasing, there is limited information on their premature aging related health characteristics and how it may change with increasing age. The present paper provides information of the institutional manager's perception on early onset aging and service preparation for this…

  6. Early Onset Ageing and Service Preparation in People with Intellectual Disabilities: Institutional Managers' Perspective

    ERIC Educational Resources Information Center

    Lin, Jin-Ding; Wu, Chia-Ling; Lin, Pei-Ying; Lin, Lan-Ping; Chu, Cordia M.

    2011-01-01

    Although longevity among older adults with intellectual disabilities is increasing, there is limited information on their premature aging related health characteristics and how it may change with increasing age. The present paper provides information of the institutional manager's perception on early onset aging and service preparation for this…

  7. Early Learning Left Out: An Examination of Public Investments in Education and Development by Child Age

    ERIC Educational Resources Information Center

    Bruner, Charles; Elias, Victor; Stein, Debbie; Schaefer, Stephanie

    2004-01-01

    This study presents the most comprehensive picture, to date, of public investments in the education and development of children by three age groupings--the early learning years (roughly 0-5), the school-aged years (roughly 6-18), and the college-aged years (roughly 19-23). It is based upon detailed analysis of state, federal, and school district…

  8. Can Quantitative Muscle Strength and Functional Motor Ability Differentiate the Influence of Age and Corticosteroids in Ambulatory Boys with Duchenne Muscular Dystrophy?

    PubMed Central

    Buckon, Cathleen; Sienko, Susan; Bagley, Anita; Sison-Williamson, Mitell; Fowler, Eileen; Staudt, Loretta; Heberer, Kent; McDonald, Craig M.; Sussman, Michael

    2016-01-01

    Background: In the absence of a curative treatment for Duchenne Muscular Dystrophy (DMD), corticosteroid therapy (prednisone, deflazacort) has been adopted as the standard of care, as it slows the progression of muscle weakness and enables longer retention of functional mobility. The ongoing development of novel pharmacological agents that target the genetic defect underlying DMD offer hope for a significant alteration in disease progression; however, substantiation of therapeutic efficacy has proved challenging. Identifying functional outcomes sensitive to the early, subtle changes in muscle function has confounded clinical trials. Additionally, the alterations in disease progression secondary to corticosteroid therapy are not well described making it difficult to ascertain the benefits of novel agents, often taken concurrently with corticosteroids. Objective: The purpose of this study was to examine outcome responsiveness to corticosteroid therapy and age at the onset of a natural history study of ambulatory boys with DMD. Methods: Eighty-five ambulatory boys with DMD (mean age 93 mo, range 49 to 180 mo) were recruited into this study. Fifty participants were on corticosteroid therapy, while 33 were corticosteroid naïve at the baseline assessment. Within each treatment group boys were divided in two age groups, 4 to 7 years and 8 and greater years of age. The Biodex System 3 Pro isokinetic dynamometer was used to assess muscle strength. Motor skills were assessed using the upper two dimensions (standing/walking, running & jumping) of the Gross Motor Function Measure (GMFM 88) and Timed Motor Tests (TMTs) (10-meter run, sit to stand, supine to stand, climb 4-stairs). Two way analysis of variance and Pearson correlations were used for analysis. Results: A main effect for age was seen in select lower extremity muscle groups (hip flexors, knee extensors and ankle dorsiflexors), standing dimension skills, and all TMTs with significantly greater weakness and loss of

  9. Early patterns of sexual activity: age cohort differences in Australia.

    PubMed

    Boyle, Frances M; Dunne, Michael P; Purdie, David M; Najman, Jake M; Cook, Michele D

    2003-11-01

    Patterns of first sexual activity among Australians born between the 1940s and 1980s were analysed using data from a national telephone survey of 1784 adults (876 males; 908 females). Sixty-one percent of those randomly selected from the Australian electoral roll and contactable by telephone responded. Many trends, including earlier first intercourse--from 20 to 18 years (females) and 18.8 to 17.8 years (males)--were established with the 40-49 year cohort, whose sexual debut was in the late 1960s-70s. Significant age-cohort effects saw women in the contemporary (18-29 year) cohort draw level with males for age at first intercourse and first sex before age 16 and before leaving school. First intercourse contraceptive use climbed from 30% to 80%. Condom use quadrupled to 70%. Australian age-cohort effects are remarkably consistent with those in similar western cultures: gender convergence in sexual experience and increasing avoidance of sexually transmitted disease and pregnancy. If such trends continue, positive long-term outcomes for health and social wellbeing should result.

  10. Remnant Woven Bone and Calcified Cartilage in Mouse Bone: Differences between Ages/Sex and Effects on Bone Strength

    PubMed Central

    Ip, Victoria; Toth, Zacharie; Chibnall, John; McBride-Gagyi, Sarah

    2016-01-01

    Introduction Mouse models are used frequently to study effects of bone diseases and genetic determinates of bone strength. Murine bones have an intracortical band of woven bone that is not present in human bones. This band is not obvious under brightfield imaging and not typically analyzed. Due to the band’s morphology and location it has been theorized to be remnant bone from early in life. Furthermore, lamellar and woven bone are well known to have differing mechanical strengths. The purpose of this study was to determine (i) if the band is from early life and (ii) if the woven bone or calcified cartilage contained within the band affect whole bone strength. Woven Bone Origin Studies In twelve to fourteen week old mice, doxycycline was used to label bone formed prior to 3 weeks old. Doxycycline labeling and woven bone patterns on contralateral femora matched well and encompassed an almost identical cross-sectional area. Also, we highlight for the first time in mice the presence of calcified cartilage exclusively within the band. However, calcified cartilage could not be identified on high resolution cone-beam microCT scans when examined visually or by thresholding methods. Mechanical Strength Studies Subsequently, three-point bending was used to analyze the effects of woven bone and calcified cartilage on whole bone mechanics in a cohort of male and female six and 13 week old Balb/C mice. Three-point bending outcomes were correlated with structural and compositional measures using multivariate linear regression. Woven bone composed a higher percent of young bones than older bones. However, calcified cartilage in older bones was twice that of younger bones, which was similar when normalized by area. Area and/or tissue mineral density accounted for >75% of variation for most strength outcomes. Percent calcified cartilage added significant predictive power to maximal force and bending stress. Calcified cartilage and woven bone could have more influence in genetic

  11. Early exposure to dichlorodiphenyldichloroethylene, breastfeeding and asthma at age six.

    PubMed

    Sunyer, J; Torrent, M; Garcia-Esteban, R; Ribas-Fitó, N; Carrizo, D; Romieu, I; Antó, J M; Grimalt, J O

    2006-10-01

    Our aims were to assess association of dichlorodiphenyldichloroethylene (DDE) with childhood asthma measured up to age 6 and the effect of DDE on the protective effect of breastfeeding on asthma. In addition, we attempted to assess the relevant time-window of DDE exposure (i.e. at birth or at 4 years). All women presenting for antenatal care in Menorca, Spain over a 12-month period beginning in mid-1997 were invited to take part in a longitudinal study that included a yearly visit. Four hundred eighty-two children were enrolled and 462 provided complete outcome data after 6.5 years of follow-up. Organochlorine compounds were measured in cord serum of 402 (83%) infants and in blood samples of 285 children aged 4. We defined asthma as the presence of wheezing at age 6 and during any preceding year or doctor-diagnosed asthma, and used skin prick test at age 6 to determine atopic status. Results At birth and 4 years of age, all children had detectable levels of DDE (median 1 ng/mL and 0.8 ng/mL, respectively). From birth to age 4, the mean DDE level among children with artificial feeding decreased by 72%, while among breastfed children it increased by 53%. Diagnosed asthma and persistent wheezing were associated with DDE at birth [odds ratio (OR) for an increase in 1 ng/mL, OR=1.18, 95% confidence interval (95% CI)=1.01-1.39 and OR=1.13, 95% CI=0.98-1.30, respectively], but not with DDE at 4 years. Neither breastfeeding nor atopy modified these associations (P>0.3). Breastfeeding protected against diagnosed asthma (OR=0.33, 95% CI=0.08-0.87) and wheezing (OR=0.53, 95% CI=0.34-0.82) in children with low and high DDE levels at birth. Conclusion In a community without known dichlorodiphenyltrichloroethane environmental releases, this study strengthens the evidence for an effect of DDE on asthma by measuring the disease at age 6 and does not support the hypothesis that DDE modifies the protective effect of breastfeeding on asthma.

  12. The influence of age and type of force on muscle strength capabilities in women.

    PubMed

    Tokarski, Tomasz; Roman-Liu, Danuta; Kamińska, Joanna

    2012-01-01

    The aim of this study was to assess handgrip and 5 other types of force in 52 women and to determine if handgrip force reflected general upper limb force capabilities correlated with age. The women were divided into subgroups according to age: 20-25, 45-50 and 55-65 years. Maximum forces of the right upper limb were measured in 6 types of force activities. In most tests the values of force showed statistically significant differences between the 20-25 group and the groups aged 45-50 and 55-64 years. The results did not show any differences related to age or to force activities that involved the small muscles of the forearms and hands. Thus handgrip force cannot always be considered an indicator of total force capabilities.

  13. [Age characteristics of the strength of conditioned inhibition in dogs during food and defensive reinforcement].

    PubMed

    Sergeeva, L L

    1978-01-01

    Dynamics of internal inhibition intensity was studied in case of alimentary and defensive reinforcements in 1-2-months, 3-4-months and one-year-old puppies. In half of the animals the intensity of inhibition was estimated 2-5 times before they reached 4 years of age. The animals younger than one year of age showed weak, medium and strong inhibition with both types of reinforcement. The majority of animals showed different typological characteristics in experiments with alimentary and defensive reinforcements. In alimentary system the inhibition intensity after initial enhancement stabilizes or decreases. In defensive system, up to 3-4 years of age all experimental animals showed weak inhibition. The differences between alimentary and defensive systems become more pronounced with age.

  14. [Association between early age at menarche and blood pressure in Chinese girls aged 7 to 17 years].

    PubMed

    Zou, Zhi-yong; Ma, Jun; Wang, Hai-jun; Fu, Lian-guo; Dong, Bin; Yang, Yi-de

    2013-08-01

    To investigate the association between early age at menarche and blood pressure in Chinese girls aged 7 to 17 years. A total of 76 869 girls aged 7 to 17 years old were selected from the national physical fitness and health research in 2010, and probit analyses were used to calculate the average age of menarche for each province. Girls whose age were lower than the P 10 of age at menarche were judged as early age at menarche, and matched with two selected participant without menarche based on the age and the same urban or rural areas. High blood pressure was defined as whose systolic pressure and/or diastolic pressure was higher than P 95 of systolic pressure or diastolic pressure at the same age group. The difference of the rate of high blood pressure in girls with and without menarche by Chi-square test, and multilevel model was used to analyze the relationship between early age at menarche and blood pressure. In 76 869 girls, the values of height and BMI were separately (152.2 ± 10.4) cm and (18.7 ± 3.1) kg/m(2), while the systolic pressure and diastolic pressure were (103.4 ± 11.0) mm Hg (1 mm Hg = 0.133 kPa) and (65.0 ± 9.1) mm Hg respectively. In 47 942 girls (62.4%) had occurred menstruation while 28 927 girls (37.6%) without menstruation. The girls began to report menstruation at the age of 9, and 81.5% (7123/8736) girls had already reported menstruation at the age of 13. The rate of high blood pressure in menstruation group from 11 to 13 years were separately 6.71% (100/1490), 5.99% (265/4423) and 5.38% (383/7123), which was significant higher than 3.78% (265/7005), 3.33% (144/4328) and 4.09% (66/1613) in the same age group of non-menstruation (the values of Chi-square were separately 25.62, 32.36, 4.46, and all P values < 0.05) . The mean age of early age at menarche was 9 to 11 years old, and the rate of high blood pressure, high systolic pressure, and high diastolic pressure at 11 years group was separately 6.08% (49/806), 4.84% (39/806) and 3

  15. Mild exercise early in life produces changes in bone size and strength but not density in proximal phalangeal, third metacarpal and third carpal bones of foals.

    PubMed

    Firth, Elwyn C; Rogers, Christopher W; van Weeren, P Rene; Barneveld, Albert; McIlwraith, C Wayne; Kawcak, Christopher E; Goodship, Allen E; Smith, Roger K W

    2011-12-01

    Exercise or lack of it in early life affects chondro-osseous development. Two groups of horses were used to investigate the effects of age and exercise regimen on bone parameters of diaphyseal, metaphyseal, epiphyseal and cuboidal bones of the distal limb of Thoroughbreds. One group had exercised only spontaneously from an early age at pasture (PASTEX group), while the other group of horses were exposed to a 30% greater workload through additional defined exercise (CONDEX). Longitudinal data from peripheral quantitative computed tomography (pQCT) were obtained from eight scan sites of the left forelimb (proximal phalangeal (P(p); 1 site), third metacarpal (Mc3; six sites) and third carpal (C(3); one site) bones) of 32 Thoroughbred foals scanned five times from ∼3 weeks to 17 months of age. The primary outcome measures were bone mineral content (BMC), bone area (BA), and periosteal circumference (Peri C) in diaphyseal bone, with cortical thickness (CortTh), volumetric bone mineral density (BMD(v)) and a bone strength index (SSI) also being analysed. At the P(p) site within the model there was a significant effect (P=0.00-0.025) of conditioning exercise increasing bone parameters, except endosteal circumference (Endo C) and BMD(v). The BMC, BA, and SSI of P(p) were significantly greater in the CONDEX than PASTEX groups at 12 and 17 months (P=0.015-0.042) and CortTh at 17 months (P=0.033). At the M55 site of Mc3 BMC, BA and SSI (P=0.02-0.04), and at the M33 site, SSI (P=0.05) were higher in the CONDEX than PASTEX group. The adaptive responses, consistent with diaphyseal strengthening, were more marked in the diaphysis of P(p) than Mc3. In the Mc3, metaphysis, trabecular BMD(v) was less in the CONDEX than PASTEX group, associated with greater bone mineral accretion in the outer cortical-sub-cortical bone in the CONDEX group. There were no significant between-group differences in any epiphyseal or cuboidal bone parameter. Although the early imposed exercise regimen

  16. Effect of resin cement, aging process and root level on the bond strength of the resin-fiber posts

    NASA Astrophysics Data System (ADS)

    Almuhim, Khalid Salman

    Background. Little is known about the long-term clinical bonding effectiveness of the Fiber-reinforced composite (FRC) posts cemented with self-etch adhesive systems. Bond stability and longevity of the cemented post are adversely affected by physical and chemical factors over time, such as expansion and contraction stresses caused by thermal changes and occlusal load. This clinical condition can be simulated in vitro by thermocyclic loading; and bonding effectiveness can be evaluated by applying the micropush out test. Therefore, more in vitro studies are needed to evaluate the bond strength of the fiber posts cemented with different resin cement systems after simulating the artificial aging induced by thermocycling. The aim of this study was to compare the microtensile bond strength of two different resin cement systems (total etch, and self-etch resin cement system) used for cementation of fiber reinforced composite posts in three different aging periods using thermocycling. Methods. Following IRB approval, sixty freshly extracted bicuspid single rooted natural teeth were endodontically treated, and the post-spaces were prepared to receive a fiber-post cemented with either a total etch resin cement (Rely-X Ultimate) or with a self-etch resin cement (Rely-X Unicem). No thermocycling, 20,000 and 40,000 cycles was used to age the specimens. Teeth were randomly allocated into six different groups: G1 - Control: Rely-X Ultimate cement with no thermocycling. G2: Rely-X Ultimate cement with 20,000 thermocycling. G3: Rely-X Ultimate cement with 40,000 thermocycling. G4: Rely-X Unicem cement. G5: Rely-X Unicem cement. G6: Rely-X Unicem cement. Microtensile bond strength determined using a micropush out test on a universal testing machine (MTS). Additionally, the failure mode of each specimen was observed under a stereomicroscope (Olympus) at 40x magnification. Finally, one representative sample was randomly selected from each of the five failure modes for scanning

  17. Effect of regular swimming exercise on the physical composition, strength, and blood lipid of middle-aged women

    PubMed Central

    Lee, Bo-Ae; Oh, Deuk-Ja

    2015-01-01

    The purpose of this study is to define the effects of regular swimming exercise on the physical composition, physical strength, and blood lipids of middle-aged women. The subjects of this study are a total of 24 middle-aged women in the swimming group and the control group, with 12 women for each group. The swimming group performed swimming exercise for 60 min every time for 3 times a week, for a total of 12 weeks. For data processing, SPSS 21.0 statistics program was used to calculate the mean and standard deviation. For the difference verification on the change in mean for each group and between the groups, paired and independent t-tests were respectively used. As a result, for physical composition, the body fat rate decreased in the swimming group. Moreover, the difference verification result showed a statistically significant difference between the groups. For physical strength, the difference verification result for each group showed that the swimming group had a statistically significant difference in flexibility and cardiovascular endurance. Moreover, the difference verification result between the groups showed a statistically significant difference only for flexibility. For blood lipids, as a result of the difference verification for each group, T-C and TG showed a significant decrease, and HDL-C, a significant increase. However, in the difference verification result between the groups, only T-C and TG showed a statistically significant difference. With these results, it is considered that regular swimming exercise is effective for improving the physical composition, physical strength, and blood lipids of middle-aged women. PMID:26535217

  18. Nanoleakage, ultramorphological characteristics, and microtensile bond strengths of a new low-shrinkage composite to dentin after artificial aging.

    PubMed

    Duarte, Sillas; Phark, Jin-Ho; Varjão, Fabiana Mansur; Sadan, Avishai

    2009-05-01

    To study the microtensile bond strengths and nanoleakage of low-shrinkage composite to dentin. The null hypotheses tested were (1) aging does not affect the bonding of low-shrinkage composite; (2) there is no difference in microtensile bond strengths and nanoleakage using different bonding strategies. 32 extracted molars were assigned to one of four groups: LS System Adhesive (LS, 3M ESPE); dentin etched for 15s with phosphoric acid+LS System Adhesive (LSpa); Adper Single Bond Plus (SB, 3M ESPE); SB+LS Bond (SBLS). Occlusal dentin was exposed and restored with Filtek LS (3M ESPE). The samples were tested after 24h or after 20,000 thermocycles and 6 months of aging. Teeth were sectioned with a cross-section of 0.8+/-0.2mm(2) and fractured at a crosshead speed of 1mm/min. The data were submitted to ANOVA/Duncan's post hoc test, at p<0.05. Five slabs from each group were selected and immersed in 50wt% ammoniacal silver nitrate. Then, specimens were processed for SEM, the silver penetration was measured and data analyzed with Kruskal-Wallis at p<0.05. No statistically significant difference was found among the experimental groups for the factor dentin treatment (p=0.165) and aging (p=0.091). All experimental groups exhibit some degree of nanoleakage. There was no adhesion of Filtek LS applied directly over dentin surfaces treated with SB. The new low-shrinkage resin composite showed compatibility only with its dedicated adhesive. Pre-etching did not improve the bond strengths to low-shrinkage resin composite. Some degree of nanoleakage was evident in all groups.

  19. Can age-related CNS taste differences be detected as early as middle age? Evidence from fMRI

    PubMed Central

    Green, Erin; Jacobson, Aaron; Haase, Lori; Murphy, Claire

    2012-01-01

    Middle-aged Americans have higher obesity rates than any other age group, yet little is known about age-related changes in central taste function during this critical time. Research on taste and aging has primarily focused on psychophysical responses, and on older adults. Central taste processing in middle-age has not been investigated. In the current study, we compared fMRI activation of young and middle-aged adults during hedonic evaluation of a sweet and a bitter taste. A 2 (age group) by 2 (tastant) analysis of variance (ANOVA) on fMRI activation revealed: (1) a main effect of age (young adults > middle-aged adults) in the bilateral anterior cingulate, lentiform nucleus, putamen, caudate, and right precentral gyrus; (2) a main effect of taste (sweet > bitter) in the bilateral pre- and postcentral gyri, anterior cingulate and right middle frontal gyrus; qualified by (3) an age by taste interaction. Further inspection of the age by taste interaction revealed that there was a significant effect of age (greater activation in young adults) in sensory (insula) and reward (lentiform nucleus) regions during hedonic evaluation of the sweet taste; however, there was no age effect in the bitter taste condition. Further, young adults had greater responses during hedonic evaluation of sucrose than of caffeine in several sensory and motor processing regions (pre- and postcentral gyri, insula), but there were no taste-related differences in activation in the middle-aged adults. We speculate that these results might reflect early age-related differences in central taste processing that occur prior to deficits in gustatory function observed in old age, and this might have important implications for weight changes that occur during middle-age. PMID:23211563

  20. Can age-related CNS taste differences be detected as early as middle age? Evidence from fMRI.

    PubMed

    Green, E; Jacobson, A; Haase, L; Murphy, C

    2013-03-01

    Middle-aged Americans have higher obesity rates than any other age group, yet little is known about age-related changes in central taste function during this critical time. Research on taste and aging has primarily focused on psychophysical responses, and on older adults. Central taste processing in middle-age has not been investigated. In the current study, we compared functional magnetic resonance imaging (fMRI) activation of young and middle-aged adults during hedonic evaluation of a sweet and a bitter taste. A 2 (age group) by 2 (tastant) analysis of variance (ANOVA) on fMRI activation revealed: (1) a main effect of age (young adults>middle-aged adults) in the bilateral anterior cingulate, lentiform nucleus, putamen, caudate, and right precentral gyrus; (2) a main effect of taste (sweet>bitter) in the bilateral pre- and postcentral gyri, anterior cingulate and right middle frontal gyrus; qualified by (3) an age-by-taste interaction. Further inspection of the age-by-taste interaction revealed that there was a significant effect of age (greater activation in young adults) in sensory (insula) and reward (lentiform nucleus) regions during hedonic evaluation of the sweet taste; however, there was no age effect in the bitter taste condition. Further, young adults had greater responses during hedonic evaluation of sucrose than of caffeine in several sensory and motor processing regions (pre- and postcentral gyri, insula), but there were no taste-related differences in activation in the middle-aged adults. We speculate that these results might reflect early age-related differences in central taste processing that occur prior to deficits in gustatory function observed in old age, and this might have important implications for weight changes that occur during middle-age. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Quantitative analysis of cone photoreceptor distribution and its relationship with axial length, age, and early age-related macular degeneration.

    PubMed

    Obata, Ryo; Yanagi, Yasuo

    2014-01-01

    It has not been clarified whether early age-related macular degeneration (AMD) is associated with cone photoreceptor distribution. We used adaptive optics fundus camera to examine cone photoreceptors in the macular area of aged patients and quantitatively analyzed its relationship between the presence of early AMD and cone distribution. Sixty cases aged 50 or older were studied. The eyes were examined with funduscopy and spectral-domain optical coherence tomography to exclude the eyes with any abnormalities at two sites of measurement, 2° superior and 5° temporal to the fovea. High-resolution retinal images with cone photoreceptor mosaic were obtained with adaptive optics fundus camera (rtx1, Imagine Eyes, France). After adjusting for axial length, cone packing density was calculated and the relationship with age, axial length, or severity of early AMD based on the age-related eye disease study (AREDS) classification was analyzed. Patient's age ranged from 50 to 77, and axial length from 21.7 to 27.5 mm. Mean density in metric units and that in angular units were 24,900 cells/mm2, 2,170 cells/deg2 at 2° superior, and 18,500 cells/mm2, 1,570 cels/deg2 at 5° temporal, respectively. Axial length was significantly correlated with the density calculated in metric units, but not with that in angular units. Age was significantly correlated with the density both in metric and angular units at 2° superior. There was no significant difference in the density in metric and angular units between the eyes with AREDS category one and those with categories two or three. Axial length and age were significantly correlated with parafoveal cone photoreceptor distribution. The results do not support that early AMD might influence cone photoreceptor density in the area without drusen or pigment abnormalities.

  2. Rejuvenation of the muscle stem cell population restores strength to injured aged muscles.

    PubMed

    Cosgrove, Benjamin D; Gilbert, Penney M; Porpiglia, Ermelinda; Mourkioti, Foteini; Lee, Steven P; Corbel, Stephane Y; Llewellyn, Michael E; Delp, Scott L; Blau, Helen M

    2014-03-01

    The elderly often suffer from progressive muscle weakness and regenerative failure. We demonstrate that muscle regeneration is impaired with aging owing in part to a cell-autonomous functional decline in skeletal muscle stem cells (MuSCs). Two-thirds of MuSCs from aged mice are intrinsically defective relative to MuSCs from young mice, with reduced capacity to repair myofibers and repopulate the stem cell reservoir in vivo following transplantation. This deficiency is correlated with a higher incidence of cells that express senescence markers and is due to elevated activity of the p38α and p38β mitogen-activated kinase pathway. We show that these limitations cannot be overcome by transplantation into the microenvironment of young recipient muscles. In contrast, subjecting the MuSC population from aged mice to transient inhibition of p38α and p38β in conjunction with culture on soft hydrogel substrates rapidly expands the residual functional MuSC population from aged mice, rejuvenating its potential for regeneration and serial transplantation as well as strengthening of damaged muscles of aged mice. These findings reveal a synergy between biophysical and biochemical cues that provides a paradigm for a localized autologous muscle stem cell therapy for the elderly.

  3. Strength of noise effects on memory as a function of noise source and age.

    PubMed

    Boman, E; Enmarker, I; Hygge, S

    2005-01-01

    The objectives in this paper were to analyse noise effects on episodic and semantic memory performance in different age groups, and to see whether age interacted with noise in their effects on memory. Data were taken from three separate previous experiments, that were performed with the same design, procedure and dependent measures with participants from four age groups (13-14, 18-20, 35-45 and 55-65 years). Participants were randomly assigned to one of three conditions: (a) meaningful irrelevant speech, (b) road traffic noise, and (c) quiet. The results showed effects of both noise sources on a majority of the dependent measures, both when taken alone and aggregated according to the nature of the material to be memorised. However, the noise effects for episodic memory tasks were stronger than for semantic memory tasks. Further, in the reading comprehension task, cued recall and recognition were more impaired by meaningful irrelevant speech than by road traffic noise. Contrary to predictions, there was no interaction between noise and age group, indicating that the obtained noise effects were not related to the capacity to perform the task. The results from the three experiments taken together throw more light on the relative effects of road traffic noise and meaningful irrelevant speech on memory performance in different age groups.

  4. Effect of aging with partial discharges on the remnant breakdown strength of polypropylene films with natural and synthetic nanofillers

    NASA Astrophysics Data System (ADS)

    Rab, Md. A.; Dhara, Rohitha; Basappa, Prathap; Poda, Anil B.

    2014-08-01

    Uniform dispersion of small amounts of nanofillers into Polypropylene (PP) base polymer have shown to improve the dielectric properties such as Partial Discharge (PD) resistance and breakdown strength (BDS). A comparative analyses of the effect of addition of natural and synthetic nanofillers on the PD characteristics and the BDS prior to and after aging with PD have been performed. Results indicate that addition of both type of fillers significantly reduce maximum PD magnitude (Qmax). The Weibull characteristic BDS magnitudes were observed to improve with addition of nanofillers.

  5. Loading dose of physical activity is related to muscle strength and bone density in middle-aged women.

    PubMed

    Chahal, Jaswinder; Lee, Raymond; Luo, Jin

    2014-10-01

    The aim of the current study was to investigate the association between loading dose of physical activity, muscle strength and bone density in middle-aged women. Thirty four healthy women (mean age=49.8±7.5years) were recruited. They were requested to wear an accelerometer for a period of 10h (from 9am to 7pm) on a day to record the acceleration. On a separate day their knee extension torque (KET) was measured using an isokinetic dynamometer and broadband ultrasound attenuation (BUA) at the heel by an ultrasound bone scanner. The loading dose of physical activity was calculated at four intensity categories - very light, light, moderate, and vigorous (intensities of <5BW/s, 5-10BW/s, 10-15BW/s and >15BW/s) and for three frequency bands - 0.1-2Hz, 2-4Hz, and 4-6Hz. Correlation analysis was used to examine the association between loading dose and age, KET, and BUA. With the increase of age, there tended to be a decrease in the loading dose of vigorous activity in 2-4 and 4-6Hz frequency bands (Kendall's tau=-.22, p<.1). The increase of loading dose in all three frequency bands in moderate or vigorous activity was associated with higher BUA (Kendall's tau=.27-.41, p<.05). The increase of loading dose in all frequency bands in light, moderate, or vigorous activity was associated with higher KET (Kendall's tau=.30-.45, p<.05). It is concluded that physical activity, especially that at high intensity level and high frequency range, may have beneficial effect on muscle strength and bone density in middle-aged women.

  6. The magnitude and rate of reduction in strength, dexterity and sensation in the human hand vary with ageing.

    PubMed

    Bowden, Jocelyn L; McNulty, Penelope A

    2013-08-01

    Cutaneous sensation and motor performance of the hand decline with age. It is not known if motor performance declines are influenced by reductions in cutaneous sensation, or if motor performance deteriorates at a consistent rate across motor tasks. Handgrip strength, finger-tapping frequency and grooved-pegboard performance were assessed for both hands of 70 subjects (20-88 years), 10 per decade. Motor declines were compared to reductions in perceptual cutaneous sensation tested at 10 hand sites using calibrated von Frey filaments. Motor performance decreased with age for all motor tasks (p<0.001). Handgrip strength (mean±SEM) decreased from 42.6±9.5 kg (in the 30s), to 23.7±7.6 kg (80s) or 44%; finger-tapping frequency from 6.4±0.8 Hz to 4.2±0.9 Hz, 34%; and grooved-pegboard (median [IQR]) increased from 59 s [57-66 s] to 111.5 s [101-125 s], 47%. The onset of the deterioration in motor performance varied with sex and task. Cutaneous sensation also decreased with age, measured as increased von Frey thresholds of 0.04 g [0.02-0.07] to 0.16 g [0.04-0.4] (p<0.001) between the 20s and the 80s, or 73%. Cutaneous sensation varied with sex, side-tested and site. Reductions in grip-based tasks were associated with sensory declines in the palm, but elsewhere there was little correlation among motor tasks and cutaneous sensation in the hand. Grooved-pegboard performance was the best predictor of age-related declines in motor performance regardless of sex or side-tested. Our results suggest age-related declines in motor function cannot be inferred from, or provide information about, changes in cutaneous sensation. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Microtensile bond strength between indirect composite resin inlays and dentin: effect of cementation strategy and mechanical aging.

    PubMed

    Prochnow, Emília Pithan; Amaral, Marina; Bergoli, César Dalmolin; Silva, Tatiana Bernardon; Saavedra, Guilherme; Valandro, Luiz Felipe

    2014-08-01

    To evaluate the microtensile bond strength of indirect resin composite inlays to dentin using two cementation strategies, before and after mechanical aging. Standardized inlay cavities (bucco-lingual width: 3 mm; depth: 4 mm) were prepared in 32 human premolars. The teeth were embedded in self-curing acrylic resin up to 3 mm from the cementoenamel junction, impressions were made using a polyvinyl siloxane material, master dies were obtained using type 4 stone, and inlay composite resin restorations were fabricated (Sinfony, 3M ESPE). The teeth were randomly allocated into 4 groups according to the cementation strategy (conventional [C] and simplified [S]) and aging (mechanical cycling [MC] and not aged): C[G1]: Adper SingleBond + RelyX ARC without aging; CMC[G2]: conventional cementation + mechanical cycling (106 cycles, 88 N, 4 Hz, ± 37°C); S[G3]: self-adhesive resin cement (RelyX U-100) without aging; SMC[G4] self-adhesive cementation + mechanical cycling. Intaglio surfaces of composite inlays were treated by tribochemical silica coating in G1 and G2, while G3 and G4 received no surface treatment. Non-aged specimens were stored in a moist environment at ca 37°C for the same period as MC (3 days). Non-trimmed beam specimens (bonding area = 1 mm²) were produced by serial cutting, and microtensile testing was performed (0.5 mm/min). Two-way ANOVA showed that the microtensile bond strength was affected only by cementation strategy (p < 0.0001). Tukey's test showed that groups G1 (35.1 ± 9.1) and G2 (32.7 ± 10.7) presented significantly higher bond strength values than G3 (8.7 ± 6.3) and G4 (5.2 ± 4.6). The use of a conventional adhesive technique and tribochemical silica coating resulted in higher μTBS than the one-step simplified cementation, even after mechanical cycling.

  8. Emergent Literacy Skills during Early Childhood in Children with Hearing Loss: Strengths and Weaknesses

    ERIC Educational Resources Information Center

    Easterbrooks, Susan R.; Lederberg, Amy R.; Miller, Elizabeth M.; Bergeron, Jessica P.; Connor, Carol McDonald

    2008-01-01

    The difficulties for students with hearing loss in gaining proficient literacy skills are well documented. However, studies describing the nature and variability of emergent literacy skills for students with hearing loss or the rate at which progress occurs at young ages are limited. We assessed emergent literacy skills and outcomes at the…

  9. Perceptions of Competence, Strength, and Age Influence Voters to Select Leaders with Lower-Pitched Voices

    PubMed Central

    Klofstad, Casey A.; Anderson, Rindy C.; Nowicki, Stephen

    2015-01-01

    Voters prefer leaders with lower-pitched voices because they are perceived as stronger, having greater physical prowess, more competent, and having greater integrity. An alternative hypothesis that has yet to be tested is that lower-pitched voices are perceived as older and thus wiser and more experienced. Here the relationships between candidate voice pitch, candidate age, and electoral success are examined with two experiments. Study 1 tests whether voters discriminate on candidate age. The results show that male and female candidates in their 40s and 50s, the time in the lifecycle when voice pitch is at its lowest, are preferred over candidates in their 30s, 60s, and 70s. Study 2 shows that the preference for leaders with lower-pitched voices correlates with the perception that speakers with lower voices are stronger, more competent, and older, but the influence of perception of age on vote choice is the weakest of the three. PMID:26252894

  10. Early-age neutering of dogs and cats in the United States (a review).

    PubMed

    Olson, P N; Kustritz, M V; Johnston, S D

    2001-01-01

    Prepubertal gonadectomy, often referred to as early-age neutering, has increased in popularity in the United States. The procedure is often used at animal care and control facilities, where puppies and kittens are neutered as early as 7 weeks of age or before adoption. Although the anaesthetic and surgical procedures appear to be safe, studies continue to evaluate the long-term effects on health and behaviour. Early-age neutering is one technique that is used to combat pet overpopulation, a problem whereby millions of unwanted healthy dogs and cats are euthanased each year. Although neutering animals is helpful in controlling pet overpopulation, other factors must be considered. In addition, many animals are relinquished to shelters when they show inappropriate behaviours, because owners and veterinarians are unable to modify animal behaviour. This review discusses early-age neutering in the United States, and includes the review of scientific studies that have evaluated this procedure in puppies and kittens. Early-age neutering does not stunt growth in dogs or cats (a once-held belief), but may alter metabolic rates in cats. The anaesthetic and surgical procedures are apparently safe for young puppies and kittens; morbidity is lower and recovery is faster than in adult animals. To date, adverse side effects are apparently no greater in animals neutered at early ages (7 weeks) than in those neutered at the conventional age (7 months).

  11. Modeling old-age wealth with endogenous early-life outcomes: The case of Mexico.

    PubMed

    DeGraff, Deborah S; Wong, Rebeca

    2014-04-01

    This paper contributes to the literature on the life course and aging by examining the association between early-life outcomes and late-life well being, using data from the Mexican Health and Aging Study. Empirical research in this area has been challenged by the potential endogeneity of the early-life outcomes of interest, an issue which most studies ignore or downplay. Our contribution takes two forms: (1) we examine in detail the potential importance of two key life-cycle outcomes, age at marriage (a measure of family formation) and years of educational attainment (a measure of human capital investment) for old-age wealth, and (2) we illustrate the empirical value of past context variables that could help model the association between early-life outcomes and late-life well being. Our illustrative approach, matching macro-level historical policy and census variables to individual records to use as instruments in modeling the endogeneity of early-life behaviors, yields a statistically identified two-stage model of old-age wealth with minimum bias. We use simulations to show that the results for the model of wealth in old age are meaningfully different when comparing the approach that accounts for endogeneity with an approach that assumes exogeneity of early-life outcomes. Furthermore, our results suggest that in the Mexican case, models which ignore the potential endogeneity of early-life outcomes are likely to under-estimate the effects of such variables on old-age wealth.

  12. Modeling old-age wealth with endogenous early-life outcomes: The case of Mexico

    PubMed Central

    DeGraff, Deborah S.; Wong, Rebeca

    2014-01-01

    This paper contributes to the literature on the life course and aging by examining the association between early-life outcomes and late-life well being, using data from the Mexican Health and Aging Study. Empirical research in this area has been challenged by the potential endogeneity of the early-life outcomes of interest, an issue which most studies ignore or downplay. Our contribution takes two forms: (1) we examine in detail the potential importance of two key life-cycle outcomes, age at marriage (a measure of family formation) and years of educational attainment (a measure of human capital investment) for old-age wealth, and (2) we illustrate the empirical value of past context variables that could help model the association between early-life outcomes and late-life well being. Our illustrative approach, matching macro-level historical policy and census variables to individual records to use as instruments in modeling the endogeneity of early-life behaviors, yields a statistically identified two-stage model of old-age wealth with minimum bias. We use simulations to show that the results for the model of wealth in old age are meaningfully different when comparing the approach that accounts for endogeneity with an approach that assumes exogeneity of early-life outcomes. Furthermore, our results suggest that in the Mexican case, models which ignore the potential endogeneity of early-life outcomes are likely to under-estimate the effects of such variables on old-age wealth. PMID:25170434

  13. Disease and mortality in the Early Bronze Age people of Bab edh-Dhra, Jordan.

    PubMed

    Ortner, D J

    1979-11-01

    During the 1977 field season at the Early Bronze Age site of Bab edh-Dhra 92 individuals were recovered from underground shaft tomb chambers. Morbid conditions found in these skeletons include trauma, possibly two cases of tuberculosis, osteomyelitis, post-menopausal osteoporosis and congenital anomalies. Of the 92 skeletons recovered 56 (61%) were 18 years of age or older, 28 (30%) were between 1 and 18 years of age and 8 (9%) were less than one year of age.

  14. Progeria and the early aging in children: a case report.

    PubMed

    Carvalho, Vania O; Celli, Adriane; Bancke Laverde, Bruno Leonardo; Cunico, Caroline; Santos Piedade, Guilherme; Lucas de Mello, Manuela; Beirao Junior, Paulo Sergio

    2016-02-17

    The Hutchinson-Gilford syndrome or progeria is a rare autosomal dominant syndrome characterized by premature aging and involvement of internal systems, such as the circulatory and locomotor. The diagnosis is essentially clinical and the manifestations become more evident from the first year of life. Long term outcome data from Progeria Research Foundation clinical trials have demonstrated an increase in survival in recent years. Even though new trials are ongoing, the recognition of this syndrome is essential to prevent cardiovascular and cerebrovascular complications. A patient, initially asymptomatic, who developed characteristic signs of the syndrome at the age of 6 months is reported. She was referred for evaluation only when she was two years and eleven months old. The diagnosis of Hutchinson-Gilford syndrome was suspected owing to clinical characteristics. The diagnosis was confirmed by genetic testing. A mutation c.1824C> T in exon 11 of the LMNA gene was detected. She was registered in the Progeria Research Foundation and was invited to participate in the weighing and supplementation program. She was included in the lonafarnib protocol study. This medication is a farnesyl transferase inhibitor that prevents the production of progerina and slows cardiovascular and neurological complications of the syndrome. This case highlights the importance of diagnosing progeria patients because they may be referred to the Progeria Research Foundation, which offers genetic screening and inclusion in clinical and therapeutic follow-up protocols without any costs. Progeria trials and research may also contribute to new drug developments related to prevention of aging and atherosclerosis in the near future.

  15. Association between handgrip strength, walking, age-related illnesses and cognitive status in a sample of Portuguese centenarians.

    PubMed

    Vaz-Patto, Maria; Bueno, Belén; Ribeiro, Óscar; Teixeira, Laetitia; Afonso, Rosa Marina

    2017-01-01

    Centenarians are a growing population in Europe and present significant variability in motor and cognitive functions. The aim of our study was to characterize health status, as well as cognitive and motor functions in a group of Portuguese centenarians. In addition, our study also aimed at analyzing the relationship between cognitive functions and the burden of diseases affecting the elderly. Fifty-two centenarians were evaluated using the Mini-Mental State Examination, short version. Walking-related parameters (velocity and time spent in the 3 m walk test), grip strength and number of age-related illnesses were also measured. The relationship between cognitive scores and time spent in the three metre walk test, velocity, grip strength and number of diseases was analysed. Cognitive scores showed a positive correlation with both handgrip strength and time spent in the three metre walk. In contrast, no association was found between cognitive scores and the presence/absence of disease, walking velocity or number of diseases present. These results suggest that in centenarians, cognitive functions may be related with motor functions.

  16. Plate tectonics on the early Earth: Limitations imposed by strength and buoyancy of subducted lithosphere

    NASA Astrophysics Data System (ADS)

    van Hunen, Jeroen; van den Berg, Arie P.

    2008-06-01

    The tectonic style and viability of modern plate tectonics in the early Earth is still debated. Field observations and theoretical arguments both in favor and against the uniformitarian view of plate tectonics back until the Archean continue to accumulate. Here, we present the first numerical modeling results that address for a hotter Earth the viability of subduction, one of the main requirements for plate tectonics. A hotter mantle has mainly two effects: 1) viscosity is lower, and 2) more melt is produced, which in a plate tectonic setting will lead to a thicker oceanic crust and harzburgite layer. Although compositional buoyancy resulting from these thick crust and harzburgite might be a serious limitation for subduction initiation, our modeling results show that eclogitization significantly relaxes this limitation for a developed, ongoing subduction process. Furthermore, the lower viscosity leads to more frequent slab breakoff, and sometimes to crustal separation from the mantle lithosphere. Unlike earlier propositions, not compositional buoyancy considerations, but this lithospheric weakness could be the principle limitation to the viability of plate tectonics in a hotter Earth. These results suggest a new explanation for the absence of ultrahigh-pressure metamorphism (UHPM) and blueschists in most of the Precambrian: early slabs were not too buoyant, but too weak to provide a mechanism for UHPM and exhumation.

  17. Early age at menarche and wheezing in adolescence. The 1993 Pelotas (Brazil) birth cohort study

    PubMed Central

    Joseph, Gary; Baptista Menezes, Ana Maria; Wehrmeister, Fernando C.

    2015-01-01

    Objective To evaluate the effect of menarche before 11 years of age on the incidence of wheezing/asthma in girls 11 to 18 years of age. Methods The study sample comprised 1,350 girls from a birth cohort that started in 1993 in the urban area of the city of Pelotas, southern Brazil; this cohort was followed until 18 years of age. We assessed wheezing by the question, “Have you ever had wheezing in the chest at any time in the past?,” from the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Early menarche was defined as occurring before 11 years of age. We estimated the cumulative incidence of wheezing excluding from the analysis all those participants who reported wheezing before age of 11 years. We performed the chi-square test to assess the association between ever wheezing and independent variables. Poisson regression models with robust variance were used to estimate cumulative incidence ratios. Results The average age at menarche in the cohort girls was 12 years (95% CI: 11.1–12.1). The prevalence of early menarche before 11 years of age was 11% (95% CI: 9.7–12.3). The cumulative incidence of wheezing from 11 to 18 years of age was 33.5% (95% CI: 30.9– 36.0). The crude association between ever wheezing in adolescence and early menarche before age 11 was 1.19 (95% CI: 0.96–1.48). After adjusting for early childhood and contemporaneous variables, no significant association for early menarche before 11 years of age and wheezing during adolescence was found (CIR: 1.18; CI95%: 0.93-1.49). Conclusion Early menarche before 11 years of age is not associated with an increased risk of wheezing during adolescence. PMID:26870751

  18. Effects of cadmium, calcium, age and parity on bone mineral, density and strength in female rats

    SciTech Connect

    Hammond, B.F.

    1985-06-01

    Weanling female rats were fed diets containing one of three levels of calcium and one of four levels of cadmium in the drinking water. Approximately 10 animals from each group were sacrificed after the first pregnancy and the remaining animals after the fourth pregnancy. Reproductive performance, plasma and bone Ca and P and bone density and strength were measured. After the first pregnancy, offspring of dams treated with 5 or 10 ppM Cd were smaller at birth than offspring of dams treated with 0 or 1 ppM Cd. Offspring of dams fed 5 or 10 ppM Cd or the 0.3% Ca diet had decreased weaning weight regardless of parity. Cadmium treatment had no effect on the plasma Ca or the Ca-P ratio. At Cd levels of 5 or 10 ppM the plasma P was increased. The 0.3% Ca diet depressed the plasma Ca and the 0.9% Ca diet elevated the plasma Ca and depressed the plasma P when compared to the 0.6% diet. Parity did not affect plasma Ca but, after four pregnancies, plasma P was decreased. Plasma Ca of mature dams was higher than that of adolescent dams but plasma P was unaffected. Bone mineral, density and strength were decreased by the 0.3% Ca diet especially when Cd levels reached 10 ppM. Increasing dietary Ca above normal increased femur Ca of dams fed 1 ppM Cd but did not increase the Ca of the femur of dams given higher levels of Cd. After the first pregnancy, femur Ca of mature dams was greater than that of adolescent dams. After the fourth pregnancy, femurs of mature dams were less strong than those of adolescent dams; however, the density was the same. Increasing dietary Ca above 0.6% lessened the detrimental effects of 5 ppM Cd ingestion on bone density. Mature dams were less affected by the 0.3% Ca 10 ppM Cd treatment than were adolescent dams. 60 refs., 3 figs., 26 tabs.

  19. Early Math Trajectories: Low-Income Children's Mathematics Knowledge from Age 4 to 11

    ERIC Educational Resources Information Center

    Rittle-Johnson, Bethany; Fyfe, Emily R.; Hofer, Kerry G.; Farran, Dale C.

    2016-01-01

    Early mathematics knowledge is a strong predictor of later academic achievement, but children from low-income families enter school with weak mathematics knowledge. An Early Math Trajectories model is proposed and evaluated within a longitudinal study of 517 low-income American children from age 4 to 11. This model includes a broad range of math…

  20. Early and Late Talkers: School-Age Language, Literacy and Neurolinguistic Differences

    ERIC Educational Resources Information Center

    Preston, Jonathan L.; Frost, Stephen J.; Mencl, William Einar; Fulbright, Robert K.; Landi, Nicole; Grigorenko, Elena; Jacobsen, Leslie; Pugh, Kenneth R.

    2010-01-01

    Early language development sets the stage for a lifetime of competence in language and literacy. However, the neural mechanisms associated with the relative advantages of early communication success, or the disadvantages of having delayed language development, are not well explored. In this study, 174 elementary school-age children whose parents…

  1. Early Math Trajectories: Low-Income Children's Mathematics Knowledge from Age 4 to 11

    ERIC Educational Resources Information Center

    Rittle-Johnson, Bethany; Fyfe, Emily R.; Hofer, Kerry G.; Farran, Dale C.

    2016-01-01

    Early mathematics knowledge is a strong predictor of later academic achievement, but children from low-income families enter school with weak mathematics knowledge. An Early Math Trajectories model is proposed and evaluated within a longitudinal study of 517 low-income American children from age 4 to 11. This model includes a broad range of math…

  2. Problem Behaviour at Early Age--Basis for Prediction of Asocial Behaviour

    ERIC Educational Resources Information Center

    Krneta, Dragoljub; Ševic, Aleksandra

    2015-01-01

    This paper analyzes the results of the study of prevalence of problem behaviour of students in primary and secondary schools. The starting point is that it is methodologically and logically justified to look for early forms of problem behaviour of students, because it is likely that adult convicted offenders at an early school age manifested forms…

  3. Early and Late Talkers: School-Age Language, Literacy and Neurolinguistic Differences

    ERIC Educational Resources Information Center

    Preston, Jonathan L.; Frost, Stephen J.; Mencl, William Einar; Fulbright, Robert K.; Landi, Nicole; Grigorenko, Elena; Jacobsen, Leslie; Pugh, Kenneth R.

    2010-01-01

    Early language development sets the stage for a lifetime of competence in language and literacy. However, the neural mechanisms associated with the relative advantages of early communication success, or the disadvantages of having delayed language development, are not well explored. In this study, 174 elementary school-age children whose parents…

  4. An Experimental Study of Early L3 Development: Age, Bilingualism and Classroom Exposure

    ERIC Educational Resources Information Center

    Stafford, Catherine A.; Sanz, Cristina; Bowden, Harriet Wood

    2010-01-01

    This research investigated Spanish-English bilingual adults' initial learning of a third language (L3), Latin, comparing the learning processes and outcomes of early- and late-onset bilinguals. Thirty-three participants were classified as Early or Late Bilinguals according to their age of arrival to the USA, and they were introduced to Latin by…

  5. Cortisol Function Among Early School-aged Homeless Children

    PubMed Central

    Cutuli, J. J.; Wiik, Kristen L.; Herbers, Janette E.; Gunnar, Megan R.; Masten, Ann S.

    2009-01-01

    SUMMARY Homelessness represents a context of extreme poverty and risk for child development. This study compared the relative influence of two classes of risk in the context of homelessness. Levels of socioeconomic resource-related risk and negative lifetime events were examined with respect to morning cortisol levels and cortisol response to a set of cognitive tasks. Participants were 66 children between the ages of 4 and 7 years staying in an emergency shelter for families. Adversities largely reflecting family level negative life events predicted higher levels of morning cortisol and differences in initial level and change over the course of the session of cognitive tasks. In contrast, a socioeconomic cumulative risk score was not associated with morning or session-related differences in cortisol. PMID:20022181

  6. Low-load high-repetition resistance training improves strength and gait speed in middle-aged and older adults.

    PubMed

    Nicholson, Vaughan P; McKean, Mark R; Burkett, Brendan J

    2015-09-01

    To determine the effect of 26 weeks of low-load high-repetition resistance training (BodyPump™) on maximal strength, gait speed, balance and self-reported health status in healthy, active middle-aged and older adults. Two-group randomised control trial. Sixty-eight apparently healthy, active adults aged over 55 years completed either 26 weeks of BodyPump™ training (PUMP) or served as control participants (CON). The BodyPump™ group (n = 32, age = 66 ± 4 years) trained twice per week for 26 weeks while the control group (n = 36, age = 66 ± 5 years) continued with their normal activities. Leg-press and Smith-machine bench-press one repetition maximum (1RM), gait speed, balance, and self-reported health status were all assessed at baseline and follow-up. Significant group-by-time interactions in favour of the BodyPump™ group were found for leg-press 1RM (PUMP + 13%, CON + 3%, p = 0.007, partial eta(2) = 0.11), Smith-machine bench-press 1RM (PUMP + 14%, CON +5%, p = 0.001, partial eta(2) = 0.18), normal gait speed (PUMP + 23%, CON +9 %, p = 0.028, partial eta(2) = 0.08) and single leg balance right (PUMP + 24%, CON - 7%, p = 0.006, partial eta(2) = 0.12). There were no group-by-time interactions for health status measures. Three participants in the BodyPump™ group withdrew from training due to injury or fear of injury related to training. Low-load high-repetition resistance training in the form of BodyPump™ is effective at improving maximal strength, gait speed and some aspects of standing balance in adults over 55 years. The training was well tolerated by the majority of participants. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. Effects of age and muscle action type on acute strength and power recovery following fatigue of the leg flexors.

    PubMed

    Thompson, Brennan J; Conchola, Eric C; Stock, Matt S

    2015-12-01

    Short-term strength and power recovery patterns following fatigue have received little research attention, particularly as they pertain to age-specific responses, and the leg flexors (i.e., hamstrings) muscle group. Thus, research is warranted addressing these issues because both age-related alterations in the neuromuscular system and mode of muscle action (e.g., eccentric, concentric, isometric) may differentially influence recovery responses from fatigue. The aim of this study was to investigate the strength and power recovery responses for eccentric, concentric, and isometric muscle actions of the leg flexors in young and older men following an isometric, intermittent fatigue-inducing protocol. Nineteen young (age = 25 ± 3 years) and nineteen older (71 ± 4) men performed maximal voluntary contractions (MVCs) for eccentric, concentric, and isometric muscle actions followed by a fatigue protocol of intermittent (0.6 duty cycle) isometric contractions of the leg flexors at 60% of isometric MVC. MVCs of each muscle action were performed at 0, 7, 15, and 30 min following fatigue. Peak torque (PT) and mean power values were calculated from the MVCs and the eccentric/concentric ratio (ECR) was derived. For PT and mean power, young men showed incomplete recovery at all time phases, whereas the older men had recovered by 7 min. Eccentric and isometric muscle actions showed incomplete recovery at all time phases, but concentric recovered by 7 min, independent of age. The ECR was depressed for up to 30 min following fatigue. More rapid and pronounced recovery in older men and concentric contractions may be related to physiological differences specific to aging and muscle action motor unit patterns. Individuals and clinicians may use these time course responses as a guide for recovery following activity-induced fatigue.

  8. Erythropoietin (EPO): EPO-receptor signaling improves early endochondral ossification and mechanical strength in fracture healing.

    PubMed

    Holstein, Joerg H; Menger, Michael D; Scheuer, Claudia; Meier, Christoph; Culemann, Ulf; Wirbel, Rainer J; Garcia, Patric; Pohlemann, Tim

    2007-02-13

    Beyond its role in the regulation of red blood cell proliferation, the glycoprotein erythropoietin (EPO) has been shown to promote cell regeneration and angiogenesis in a variety of different tissues. In addition, EPO has been indicated to share significant functional and structural homologies with the vascular endothelial growth factor (VEGF), a cytokine essential in the process of fracture healing. However, there is complete lack of information on the action of EPO in bone repair and fracture healing. Therefore, we investigated the effect of EPO treatment on bone healing in a murine closed femur fracture model using radiological, histomorphometric, immunohistochemical, biomechanical and protein biochemical analysis. Thirty-six SKH1-hr mice were treated with daily i.p. injections of 5000 U/kg EPO from day 1 before fracture until day 4 after fracture. Controls received equivalent amounts of the vehicle. After 2 weeks of fracture healing, we could demonstrate expression of the EPO-receptor (EPOR) in terminally differentiating chondrocytes within the callus. At this time point EPO-treated animals showed a higher torsional stiffness (biomechanical analysis: 39.6+/-19.4% of the contralateral unfractured femur) and an increased callus density (X-ray analysis (callus density/spongiosa density): 110.5+/-7.1%) when compared to vehicle-treated controls (14.3+/-8.2% and 105.9+/-6.6%; p<0.05). Accordingly, the histomorphometric examination revealed an increased fraction of mineralized bone and osteoid (33.0+/-3.0% versus 28.5+/-3.6%; p<0.05). Of interest, this early effect of the initial 6-day EPO treatment had vanished at 5 weeks after fracture. We conclude that EPO-EPOR signaling is involved in the process of early endochondral ossification, enhancing the transition of soft callus to hard callus.

  9. The relationship between early ego strength and adolescent responses to the threat of nuclear war

    SciTech Connect

    Andrekus, N.J.

    1989-01-01

    Ego resiliency and ego control, measured when subjects were 3 or 4 years old, were related to expectation of war, concern for the future, and activism in response to the threat of nuclear war, measured when subjects were 18 years old. Data from 92 participants in a longitudinal study of ego and cognitive development conducted by Jeanne and Jack Block at the University of California, Berkeley were used to test hypotheses. Assessments with the California Child Q-set, composited across multiple independent observers, provide measures of ego resiliency and ego control. Adolescent interviews regarding the perception of likelihood of nuclear war, how this affects their future, and their antinuclear and general political activism were scaled and rated. Early ego resiliency and ego under control were hypothesized to account for the variance in adolescent nuclear responses and activism. The only significant longitudinal relationships were in the female sample, where ego under control was found to be a significant predictor of both general political activism (p<.01) and ideas of the future being affected by the nuclear threat (p<.05). Among males, the relationship between early ego resiliency and adolescent antinuclear activism approached significance (p<.10). Adolescent personality was significantly related to several measures of nuclear response. In girls, adolescent ego under control related to perception of likelihood of nuclear war (p<.05) and antinuclear activism (p<.05), and the interaction of ego resiliency and ego under control predicted general political activism (p<.0005). In boys, adolescent ego resiliency correlated with antinuclear activism (p<.05). These findings were discussed in terms of antecedent parenting styles, and conceptual links were drawn between children's ego resiliency and security of attachment, perspective taking, and moral development.

  10. A top-down survival mechanism during early marine residency explains coho salmon year-class strength in southeast Alaska

    NASA Astrophysics Data System (ADS)

    LaCroix, Jacob J.; Wertheimer, Alex C.; Orsi, Joseph A.; Sturdevant, Molly V.; Fergusson, Emily A.; Bond, Nicholas A.

    2009-12-01

    Coho salmon ( Oncorhynchus kisutch) are a vital component in the southeast Alaska marine ecosystem and are an important regional fishery resource; consequently, understanding mechanisms affecting their year-class strength is necessary from both scientific and management perspectives. We examined correlations among juvenile coho salmon indices, associated biophysical variables, and adult coho salmon harvest data from southeast Alaska over the years 1997-2006. We found no relationship between summer indices of juvenile coho salmon growth, condition, or abundance with subsequent harvest of adult coho salmon in the region. However, using stepwise regression, we found that variation in adult coho salmon harvest was largely explained by indices of juvenile pink salmon ( Oncorhynchus gorbuscha) abundance (67%) and zooplankton abundance (24%). To determine if high juvenile pink salmon abundance indicates favorable "bottom-up" lower trophic level environmental conditions for juvenile coho salmon, we plotted abundance of juvenile pink salmon against growth and condition of juvenile coho salmon. No change in growth or condition of juvenile coho salmon was observed in relation to the abundance index for juvenile pink salmon. Therefore, we hypothesize that coho salmon year-class strength in southeast Alaska is influenced by a "top-down" predator control mechanism that results from more abundant juvenile pink salmon, which serve as a predator buffer during early marine residency.

  11. Dexmedetomidine improves early postoperative cognitive dysfunction in aged mice.

    PubMed

    Qian, Xiao-Lan; Zhang, Wei; Liu, Ming-Zheng; Zhou, Yu-Bing; Zhang, Jing-Min; Han, Li; Peng, You-Mei; Jiang, Jin-hua; Wang, Qing-Duan

    2015-01-05

    Postoperative cognitive dysfunction (POCD) is a frequent complication following major surgery in the elderly. However, the exact pathogenic mechanisms are still unknown. Dexmedetomidine, a selective alpha 2 adrenal receptor agonist, was revealed anesthesia and brain protective role. The present study aimed to examine whether dexmedetomdine protects against POCD induced by major surgical trauma under general anesthesia in aged mice. In the present study, cognitive function was assessed by Y-maze. Proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor (TNF-α), apoptosis-related factor caspase-3 and Bax were detected by real-time PCR, Western blot or immunohistochemistry. The results showed that anesthesia alone caused weak cognitive dysfunction on the first day after general anesthesia. Cognitive function in mice with splenectomy under general anesthesia was significantly exacerbated at the first and third days after surgery, and was significantly improved by dexmedetomidine administration. Splenectomy increased the expression of IL-1β, TNF-α, Bax and caspase-3 in hippocampus. These changes were significantly inversed by dexmedetomidine. These results suggest that hippocampal inflammatory response and neuronal apoptosis may contribute to POCD, and selective alpha 2 adrenal receptor excitation play a protective role.

  12. Effects of cadmium, calcium, age and parity on bone mineral, density and strength in female rats

    SciTech Connect

    Hammond, B.F.

    1985-01-01

    Weanling female rats were fed diets containing one of three levels of Ca (0.3, 0.6, or 0.9%) and one of four levels of Cd (0, 1, 5, or 10 ppm) in the drinking water. One half of each group was fed first as adolescents (55 days) and the other half as mature (110 days) females. Approximately 10 animals from each group were sacrificed after the first pregnancy and the remaining animals after the fourth pregnancy. Reproductive performance, plasma and bone Ca and P and bone density and strength were measured. After the first pregnancy, offspring of dams treated with 5 or 10 ppm Cd were smaller at birth than offspring of dams treated with 0 or 1 ppm Cd. After the fourth pregnancy, the decreased birth weight was evident only in offspring of dams treated with 10 ppm Cd. Offspring of dams fed 5 or 10 ppm Cd or the 0.3% Ca diet had decreased weaning weight regardless of parity. A 0.3% Ca diet superimposed upon a 5 or 10 ppm Cd intake decreased weaning weight of the male offspring after the first, but not the fourth, pregnancy with the offspring of adolescent dams affected more than those of mature dams. Offspring of dams fed the 0.9% Ca diet did not differ in weaning weight from the offspring of dams fed the 0.6% Ca diet. The 0.3% Ca diet depressed the plasma Ca and the 0.9% Ca diet elevated the plasma Ca and depressed the plasma P when compared to the 0.6% diet.

  13. TGFbeta inducible early gene-1 knockout mice display defects in bone strength and microarchitecture.

    PubMed

    Bensamoun, Sabine F; Hawse, John R; Subramaniam, Malayannan; Ilharreborde, Brice; Bassillais, Armelle; Benhamou, Claude L; Fraser, Daniel G; Oursler, Merry J; Amadio, Peter C; An, Kai-Nan; Spelsberg, Thomas C

    2006-12-01

    TGFbeta inducible early gene-1 (TIEG) is a member of the Sp/Krüppel-like transcription factor family originally cloned from human osteoblasts. We have previously demonstrated that TIEG plays a role in the expression of important osteoblast marker genes and in the maturation/differentiation of osteoblasts. To elucidate the function of TIEG in skeletal development and maintenance, we have generated a TIEG knockout (KO) mouse. Three-point bending tests demonstrated that the femurs of TIEG KO mice are significantly weaker than those of wild-type animals. pQCT analysis of tibias revealed significant decreases in bone content, density and size in KO animals compared to wild-type mice. Micro-CT analysis of the femoral head and vertebrae revealed increases in femoral head trabecular separation and decreases in cortical bone thickness and vertebral bone volume in KO mice relative to wild-type controls. In addition, electron microscopy indicated a significant decrease in osteocyte number in the femurs of KO mice. Taken together, these data demonstrate that the bones of TIEG KO mice display an osteopenic phenotype with significantly weaker bones and reduced amounts of cortical and trabecular bone. In summary, an important role for TIEG in skeletal development and/or homeostasis is indicated.

  14. Mixed-Age Grouping in Early Childhood--Creating the Outdoor Learning Environment

    ERIC Educational Resources Information Center

    Rouse, Elizabeth

    2015-01-01

    Children attending centre-based early childhood care and education programmes across Australia are most likely to be grouped according to age and development. While multi- or mixed-age grouping has been seen to have positive benefits on young children's learning and pro-social behaviours, this approach is not usually adopted in the organisation of…

  15. Working Memory in Early-School-Age Children with Asperger's Syndrome

    ERIC Educational Resources Information Center

    Cui, Jifang; Gao, Dingguo; Chen, Yinghe; Zou, Xiaobing; Wang, Ya

    2010-01-01

    Using a battery of working memory span tasks and n-back tasks, this study aimed to explore working memory functions in early-school-age children with Asperger's syndrome (AS). Twelve children with AS and 29 healthy children matched on age and IQ were recruited. Results showed: (a) children with AS performed better in digit and word recall tasks,…

  16. My Entirely Plausible Fantasy: Early Mathematics Education in the Age of the Touchscreen Computer

    ERIC Educational Resources Information Center

    Ginsburg, Herbert P.

    2014-01-01

    This paper offers an account of what early mathematics education could look like in an age of young digital natives. Each "Tubby," as the tablets are called, presents Nicole (our generic little child) with stimulating mathematics microworlds, from which, beginning at age 3, she can learn basic math concepts, as well as methods of…

  17. My Entirely Plausible Fantasy: Early Mathematics Education in the Age of the Touchscreen Computer

    ERIC Educational Resources Information Center

    Ginsburg, Herbert P.

    2014-01-01

    This paper offers an account of what early mathematics education could look like in an age of young digital natives. Each "Tubby," as the tablets are called, presents Nicole (our generic little child) with stimulating mathematics microworlds, from which, beginning at age 3, she can learn basic math concepts, as well as methods of…

  18. Mixed-Age Grouping in Early Childhood--Creating the Outdoor Learning Environment

    ERIC Educational Resources Information Center

    Rouse, Elizabeth

    2015-01-01

    Children attending centre-based early childhood care and education programmes across Australia are most likely to be grouped according to age and development. While multi- or mixed-age grouping has been seen to have positive benefits on young children's learning and pro-social behaviours, this approach is not usually adopted in the organisation of…

  19. Early Histories of School-Aged Children with Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Loe, Irene M.; Balestrino, Maria D.; Phelps, Randall A.; Kurs-Lasky, Marcia; Chaves-Gnecco, Diego; Paradise, Jack L.; Feldman, Heidi M.

    2008-01-01

    In a prospective study of developmental outcomes in relation to early-life otitis media, behavioral, cognitive, and language measures were administered to a large, diverse sample of children at 2, 3, 4, 6, and 9-11 years of age (N = 741). At 9-11 years of age, 9% of the children were categorized as having attention-deficit/hyperactivity disorder…

  20. Working Memory in Early-School-Age Children with Asperger's Syndrome

    ERIC Educational Resources Information Center

    Cui, Jifang; Gao, Dingguo; Chen, Yinghe; Zou, Xiaobing; Wang, Ya

    2010-01-01

    Using a battery of working memory span tasks and n-back tasks, this study aimed to explore working memory functions in early-school-age children with Asperger's syndrome (AS). Twelve children with AS and 29 healthy children matched on age and IQ were recruited. Results showed: (a) children with AS performed better in digit and word recall tasks,…

  1. Mother-Child Mutually Responsive Orientation and Conscience Development: From Toddler to Early School Age.

    ERIC Educational Resources Information Center

    Kochanska, Grazyna; Murray, Kathleen T.

    2000-01-01

    Examined the long-term consequences of mother-child mutually responsive orientation for the development of conscience at early school age. Found that mutually responsive orientation at toddler and preschool ages predicted children's conscience, even after controlling for developmental continuity of conscience. Toddler mutually responsive…

  2. Early Enrollees and Peer Age Effect: First Evidence from INVALSI Data

    ERIC Educational Resources Information Center

    Ordine, Patrizia; Rose, Giuseppe; Sposato, Daniela

    2015-01-01

    This paper estimates peer age effect on educational outcomes of Italian pupils attending primary school by exploiting changes in enrollment rules over the last few years. The empirical procedure allows to understand if there is selection in classroom formation, arguing that in the absence of pupils sorting by early age at school entry, it is…

  3. Early Histories of School-Aged Children with Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Loe, Irene M.; Balestrino, Maria D.; Phelps, Randall A.; Kurs-Lasky, Marcia; Chaves-Gnecco, Diego; Paradise, Jack L.; Feldman, Heidi M.

    2008-01-01

    In a prospective study of developmental outcomes in relation to early-life otitis media, behavioral, cognitive, and language measures were administered to a large, diverse sample of children at 2, 3, 4, 6, and 9-11 years of age (N = 741). At 9-11 years of age, 9% of the children were categorized as having attention-deficit/hyperactivity disorder…

  4. Small head circumference at birth and early age at adiposity rebound.

    PubMed

    Eriksson, J G; Kajantie, E; Lampl, M; Osmond, C; Barker, D J P

    2014-01-01

    The adiposity rebound is the age in childhood when body mass index is at a minimum before increasing again. The age at rebound is highly variable. An early age is associated with increased obesity in later childhood and adult life. We have reported that an early rebound is predicted by low weight gain between birth and 1 year of age and resulting low body mass index at 1 year. Here, we examine whether age at adiposity rebound is determined by influences during infancy or is a consequence of foetal growth. Our hypothesis was that measurements of body size at birth are related to age at adiposity rebound. Longitudinal study of 2877 children born in Helsinki, Finland, during 1934-1944. Early age at adiposity rebound was associated with small head circumference and biparietal diameter at birth, but not with other measurements of body size at birth. The mean age at adiposity rebound rose from 5.8 years in babies with a head circumference of ≤33 cm to 6.2 in babies with a head circumference of >36 cm (P for trend = 0.007). The association between thinness in infancy and early rebound became apparent at 6 months of age. It was not associated with adverse living conditions. In a simultaneous regression, small head circumference at birth, high mother's body mass index and tall maternal stature each had statistically significant trends with early adiposity rebound (P = 0.002, <0.001, 0.004). We hypothesize that the small head size at birth that preceded an early adiposity rebound was the result of inability to sustain a rapid intra-uterine growth trajectory initiated in association with large maternal body size. This was followed by catch-up growth in infancy, and we hypothesize that this depleted the infant's fat stores. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  5. Effect of Strength Training and Short-term Detraining on Muscle Mass in Women Aged Over 50 Years Old

    PubMed Central

    Delshad, Maryam; Ghanbarian, Arash; Mehrabi, Yadollah; Sarvghadi, Farzaneh; Ebrahim, Khosro

    2013-01-01

    Background: The loss of muscle mass is associated with aging. The aim of this study was to determine the effects of resistance training and detraining on muscle mass in elderly women. Methods: Twenty post-menopausal women aged ≥50 years old were enrolled. Matching for age, they were randomly assigned into control and resistance training group (RT). The intervention consisted of three sets of 10 repetitions for 10 movements with Thera-Band tubing (based on 80-100% 10-RM), three times a week, for 12 weeks and thereafter, four weeks detraining. Skinfold thickness was determined by caliper. Percentage of body fat was estimated from skinfold thickness (triceps and subscapular) by McArdle method. Fat mass (FM) and fat-free mass (FFM) were calculated. Range of motion for trunk flexion and extension was determined. Results: During 12 weeks of intervention, significant increases were observed in 1-RM of biceps curl, FFM, trunk flexion and extension and significant decreases during four weeks detraining in RT group. The RT group demonstrated significant decreases during resistance training and increases during detraining in skinfold thickness. FFM, trunk flexion, and extension decreased and skinfold thickness, %FM, and weight of body fat increased in the control group (P < 0.05). Conclusions: Resistance training with Thera-Band enhanced strength and muscle endurance in elderly women and a 4-week detraining period had an adverse effect on muscle power. This suggests that a strength training program is an effective intervention to prevent functional reductions, and can contribute to improve neuromuscular function in older adults. PMID:24498494

  6. Early-age characteristics of red mud-coal gangue cementitious material.

    PubMed

    Zhang, Na; Sun, Henghu; Liu, Xiaoming; Zhang, Jixiu

    2009-08-15

    This experimental research was to investigate the possibility of incorporating red mud and coal gangue as raw materials for the production of red mud-coal gangue cementitious material, abbreviated as RGC, including analyses of its chemical composition, physical properties, mechanical properties and hydration products. The red mud and coal gangue (at a ratio of 3:2) were mixed together and shaped in small spheres with a water to solid ratio of 0.30 and then calcined at 600 degrees C for 2h. Subsequently, the RGC was prepared by blending 50% the resultant red mud-coal gangue mixtures, 24% blast-furnace slag, 20% clinker and 6% gypsum. The hydration products of RGC were characterized by XRD, TG-DTA and SEM-EDS. The results showed that it is feasible to use red mud and coal gangue to replace up to 50% of the raw materials to produce cementitious material, which can be called as silica-alumina based cementitious material. The hydration products of RGC are mostly ettringite, calcium hydroxide and C-S-H gel. As the dominant products, C-S-H gel and ettringite are principally responsible for the strength development of RGC in early hydration process. The content of Ca(OH)(2) initially increased but later was depleted after reaching the peak value at 21 days. Moreover, it is found that the composition of the C-S-H gel shifted towards higher Si, Al and Na contents with the increase of hydration age, whereas that of Ca shifted towards lower content.

  7. From the cradle to the grave: age differences in attachment from early adulthood to old age.

    PubMed

    Chopik, William J; Edelstein, Robin S; Fraley, R Chris

    2013-04-01

    Although attachment dynamics are thought to be important across the life span, relatively few studies have examined attachment processes beyond young adulthood. Extant research on age differences in attachment orientation has yielded conflicting results and interpretations. The purpose of this study was to provide a more complete picture of age-related differences in attachment anxiety and avoidance. We examined attachment anxiety and avoidance in 86,555 Internet respondents (71.8% female) ranging in age from 18 to 70. We found that attachment anxiety was highest among younger adults and lowest among middle-aged and older adults. Attachment avoidance showed less dramatic age differences overall but was highest among middle-aged adults and lowest among younger and older adults. In addition, partnered individuals reported lower levels of attachment anxiety and avoidance compared to single individuals, particularly in younger and older adulthood. Women also reported slightly higher anxiety and avoidance compared to men, especially in young adulthood. Findings are discussed in the context of life span changes in social roles, normative personality development, and emotion regulation throughout adulthood. © 2012 Wiley Periodicals, Inc.

  8. Early Characteristics of Children with ASD Who Demonstrate Optimal Progress Between Age Two and Four.

    PubMed

    Moulton, Emily; Barton, Marianne; Robins, Diana L; Abrams, Danielle N; Fein, Deborah

    2016-06-01

    Although for many children, Autism Spectrum Disorder (ASD) is a lifelong disability, a subset of children with ASD lose their diagnosis and show typical cognitive and adaptive abilities. The ages at which this transition can occur is not known, but it sometimes occurs quite early. Participants in the current study were 207 children with an ASD at age two who were reevaluated at age four. Eighty-three percent retained an ASD diagnosis at reevaluation and 9 % showed "optimal progress": clear ASD at age two but not at age four, and average cognition, language, communication and social skills at age four. Early child-level factors predicted optimal progress: diagnosis of PDD-NOS, fewer repetitive behaviors, less severe symptomatology and stronger adaptive skills.

  9. Comparative evaluation of shear bond strengths of veneering porcelain to base metal alloy and zirconia substructures before and after aging – An in vitro study

    PubMed Central

    Sreekala, Laju; Narayanan, Mahesh; Eerali, Sunil M.; Eerali, Susil M.; Varghese, Joju; Zainaba Fathima, A. l.

    2015-01-01

    Objective: The aim of this study was to evaluate and compare the shear bond strength of veneering porcelain to base metal alloy and zirconia substructures before and after aging. Scanning electron microscopy (SEM) was used to determine the failure pattern. Materials and Methods: Twenty rectangular blocks (9 mm length × 4 mm height × 4 mm width) of base metal alloy (Bellabond plus, Bego, Germany) and zirconia (Will ceramZ zirconia K block) were fabricated for shear bond strength test. Surface of the base metal alloy block (4 mm × 4 mm area) was veneered with corresponding veneering porcelain (Ivoclar, IPS classic, vivadent). Similarly, surface of the zirconia rectangular block (4 mm × 4 mm) was veneered with corresponding veneering ceramic (Cercon ceram kiss, Degudent). Out of forty rectangular porcelain veneered core specimen, ten porcelain veneered base metal alloy specimen and ten porcelain veneered zirconia specimen were immersed in water at 37°C for one month to simulate the oral environment. Results: On comparison, the highest shear bond strength value was obtained in porcelain veneered base metal alloy before aging group followed by porcelain veneered base metal alloy after aging group, Porcelain veneered zirconia before aging group, porcelain veneered zirconia after aging group. SEM analysis revealed predominantly cohesive failure of veneering ceramic in all groups. Conclusion: Porcelain veneered base metal alloy samples showed highest shear bond strength than porcelain veneered zirconia samples. Study concluded that aging had an influence on shear bond strength. Shear bond strength was found to be decreasing after aging. SEM analysis revealed cohesive failure of veneering ceramic in all groups suggestive of higher bond strength of the interface than cohesive strength of ceramic. Hence, it was concluded that veneering ceramic was the weakest link. PMID:26942121

  10. Effects of a 20-week high-intensity strength and sprint training program on tibial bone structure and strength in middle-aged and older male sprint athletes: a randomized controlled trial.

    PubMed

    Suominen, T H; Korhonen, M T; Alén, M; Heinonen, A; Mero, A; Törmäkangas, T; Suominen, H

    2017-06-16

    This randomized, controlled, high-intensity strength and sprint training trial in middle-aged and older male sprint athletes showed significant improvements in mid-tibial structure and strength. The study reveals the adaptability of aging bone, suggesting that through a novel, intensive training stimulus it is possible to strengthen bones during aging. High-load, high-speed and impact-type exercise may be an efficient way of improving bone strength even in old age. We evaluated the effects of combined strength and sprint training on indices of bone health in competitive masters athletes, who serve as a group of older people who are likely to be able to participate in vigorous exercise of this kind. Seventy-two men (age 40-85) were randomized into an experimental (EX, n = 40) and a control (CTRL, n = 32) group. EX participated in a 20-week program combining heavy and explosive strength exercises with sprint training. CTRL maintained their usual, run-based sprint training schedules. Bone structural, strength and densitometric parameters were assessed by peripheral QCT at the distal tibia and tibial midshaft. The intervention had no effects on distal tibia bone traits. At the mid-tibia, the mean difference in the change in cortical thickness (ThCO) in EX compared to CTRL was 2.0% (p = 0.007). The changes in structure and strength were more pronounced in the most compliant athletes (training adherence >75%). Compared to CTRL, total and cortical cross-sectional area, ThCO, and the area and density-weighted moments of inertia for the direction of the smallest flexural rigidity (I minA , I minD ) increased in EX by 1.6-3.2% (p = 0.023-0.006). Polar mass distribution analysis revealed increased BMC at the anteromedial site, whereas vBMD decreased (p = 0.035-0.043). Intensive strength and sprint training improves mid-tibia structure and strength in middle-aged and older male sprint athletes, suggesting that in the presence of high-intensity loading exercise, the

  11. Archaeomagnetic Records from Early Bronze to Iron Age Mediterranean Settlements

    NASA Astrophysics Data System (ADS)

    Ertepinar, Pinar; Hammond, Megan; Hill, Mimi; Biggin, Andy; Langereis, Cor; Yener, Aslihan; Akar, Murat; Greaves, Alan; Gates, Mary; Harrison, Timothy; Özgen, Ilknur

    2017-04-01

    Recent studies on the geomagnetic field variations over the Middle East have started to take particular attention due to the presence of numerous high intensity periods proposed by various authors. Considering the recent volume of papers focused on archaeomagnetism in this region, the lack of published work centered in Turkey and Cyprus is surprising since both regions have a long cultural heritage and history of trade and immigration from neighboring countries. Here we present a large dataset of directions and intensities from seven archaeological sites in the Mediterranean with 21 subsets of directional and 40 subsets of intensity data covering a long sequence of levels from 3300 to 700 BCE. The sample sets are composed of both ex-situ potsherds and in-situ features such as mud-bricks, basalts and an ash layer. The results from the rock magnetic experiments run on at least three samples from each set indicate that the magnetic mineral assemblage is composed mostly of pseudo-single domain grain magnetite or titano-magnetite with various Ti content. The majority of the demagnetization diagrams are single component and 14 out of 21 sets have a well-defined characteristic remanent magnetization direction. The directional results show a swing of 37.6° in declination and 26.9° in inclination within an age interval of 2000 years. The archaeointensity experiments involved both microwave and thermal methods. To avoid the anisotropy effects, the applied field is either set parallel to the samples NRM or the angle between the pTRM acquired at the last step used for the best-fit segment and the applied field direction, γ, was checked and found to be less than 7.5°. For the samples that are measured in random directions with respect to their NRM, prior to the intensity experiments, the anisotropy of magnetic susceptibility was individually measured and the anisotropy degree is found to be less than 2.5%. For all the potsherds, one or two samples from each set are

  12. Early experience affects the strength of vigilance for threat in rhesus monkey infants

    PubMed Central

    Mandalaywala, Tara M.; Parker, Karen J.; Maestripieri, Dario

    2014-01-01

    Both human and nonhuman primates exhibit a cognitive bias to social threat, but little is known about how this bias develops. We investigated the development of threat bias in free-ranging infant rhesus macaques (Macaca mulatta) at 3 (N = 45) and 9 (N = 46) months of age. Three-month-old infant monkeys did not display bias, but 9-month-olds exhibited increased maintenance of attention to threatening social stimuli (vigilance for threat). To examine whether the social environment affected vigilance for threat, behavioral data on maternal rank and protectiveness were collected across the first 12 weeks of life for infants tested at 9 months. Nine-month-old infants of high-ranking mothers and more protective mothers displayed greater vigilance for threat than infants of lower-ranking and less protective mothers. These results demonstrate that infant social cognition is malleable and shaped by mothers both directly (protectiveness) and indirectly (rank), as maternal characteristics affect infants’ social experiences. PMID:25125426

  13. Confirmation of a late Oligocene-early Miocene age of the Deseadan Salla Beds of Bolivia.

    USGS Publications Warehouse

    Naeser, C.W.; McKee, E.H.; Johnson, N.M.; Macfadden, B.J.

    1987-01-01

    Three new fission-track (zircon) and four new K-Ar (biotite) dates corroborate a late Oligocene-early Miocene age (22-28 Ma) for the Salla Beds of Bolivia. These ages contrast markedly with the previously accepted age of about 35 Ma for these strata and their contained faunas, and recasts of order and chronology of interchange between New World and Old World mammals. -Authors

  14. Organizations' Ways of Employing Early Retirees: The Role of Age-Based HR Policies.

    PubMed

    Oude Mulders, Jaap; Henkens, Kène; Schippers, Joop

    2015-06-01

    We examine whether from an organizational perspective it is possible to distinguish different ways of employing early retirees and explore how the employment of early retirees is related to the application of 4 age-based human resource (HR) policies, namely demotion, offering training opportunities to older workers, offering early retirement, and allowing flexible working hours. We perform a latent class analysis on a sample of 998 Dutch organizations in order to categorize them based on 3 dimensions of their employment of early retirees. We then run a multinomial logistic regression to relate the employment of early retirees to the 4 age-based HR policies. We distinguish 4 types of organizations based on their way of employing early retirees: nonusers (52.6%), users for mainly standard work (20.8%), users for mainly nonstandard work (9.8%), and users for standard and nonstandard work (16.7%). We find that organizations that apply demotion, offer early retirement, and allow flexible working hours are more likely to be users for mainly standard work. Also, organizations that do not offer early retirement are less likely to employ early retirees. Age-based HR policies, especially demotion, offering early retirement, and allowing flexible working hours, are conducive to the employment of early retirees for mainly standard work. Broader implementation of these policies may provide opportunities for older workers to make a more gradual transition from work to retirement. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Relative Handgrip Strength Is a Simple Indicator of Cardiometabolic Risk among Middle-Aged and Older People: A Nationwide Population-Based Study in Taiwan

    PubMed Central

    Lee, Wei-Ju; Peng, Li-Ning; Chiou, Shu-Ti; Chen, Liang-Kung

    2016-01-01

    Background Muscle strength may play an important role in cardiovascular health. The study was intended to evaluate the association between cardiometabolic risk, risk of coronary artery disease and handgrip strength by using the relative handgrip strength. Materials and Methods Data of 927 Taiwanese aged 53 years and older (510 men and 417 women) were retrieved from a nationwide representative population-based cohort cross-sectional study in 2006. All participants were interviewed face-to-face and received measures of anthropometry, dominant handgrip strength, relative handgrip strength (summation of both handgrip strength divided by body mass index) and serum biomarkers. Results Multivariate linear regression analysis showed the significant association between relative handgrip strength and favorable cardiometabolic risk factors including blood pressure, triglyceride, total cholesterol to high density cholesterol(HDL-C) ratio, glycohemoglobin (HbA1c), uric acid, Framingham risk score in men, and HDL-C, fasting glucose, HbA1c, log hsCRP in women. Dominant hand grip strength was only associated with log hsCRP in women. (p<0.05 for all), but was not significant associated with all cardiovascular biomarkers and FRS in both sex. Conclusions Joint with handgrip strength and body size, as relative handgrip strength, may be a better tool to capture conceptual concomitant health, which may be a simple, inexpensive, and easy-to-use tool when targeting cardiovascular health in public health level. PMID:27559733

  16. Effects of Strength Training and Anabolic Steroid in the Peripheral Nerve and Skeletal Muscle Morphology of Aged Rats

    PubMed Central

    Krause Neto, Walter; Silva, Wellington de A.; Ciena, Adriano P.; Nucci, Ricardo Aparecido Baptista; Anaruma, Carlos A.; Gama, Eliane F.

    2017-01-01

    Thirty male 20-month-old Wistar rats were divided into groups: IC—initial control (n = 6), FC—final control (n = 6), AC—anabolic hormone control (n = 6), ST—strength trained (n = 6) and STA—strength trained with anabolic hormone (n = 6). All groups were submitted to adaptation, familiarization and maximum load carrying test (MLCT). Strength training (6–8×/session with loads of 50%–100% MLCT, 3×/week and pause of 120 s) was performed in ladder climbing (LC) for 15 weeks. The administration of testosterone propionate (TP) was performed 2×/week (10 mg/kg) in animals in the AC and STA groups. After the experimental period, animals were euthanized and the tibial nerve and plantaris muscle removed and prepared for electron transmission and histochemistry. To compare the groups we used one-way ANOVA (post hoc Bonferroni), student’s t-tests for pre vs. post (dependent and independent variables) comparisons and significance level set at p ≤ 0.05. The following significant results were found: (a) aging decreased the number of myelinated axon fibers; (b) use of isolated TP increased the diameter of myelinated fibers, along with increased thickness of myelin sheath; (c) ST increased area of myelinated and unmyelinated fibers, together with the myelin sheath. These changes made it possible to increase the area occupied by myelinated fibers keeping their quantity and also reduce the interstitial space; and (d) association of anabolic steroid and ST increased the area of unmyelinated axons and thickness of the myelin sheath. Compared to ST, both strategies have similar results. However, Schwann cells increased significantly only in this strategy. PMID:28713262

  17. Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge

    PubMed Central

    Amin, Muhammad Nasir; Khan, Kaffayatullah; Saleem, Muhammad Umair; Khurram, Nauman; Niazi, Muhammad Umar Khan

    2017-01-01

    In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD) and granite sludge (GS), respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days) containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD), fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures) and curing moisture (continuously moist and partially moist followed by air curing). Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM) and mortar containing fly ash (FA). The test results indicated that under normal curing (20 °C, moist cured), the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations) remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more) incorporating local environmental conditions. PMID:28772999

  18. Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge.

    PubMed

    Amin, Muhammad Nasir; Khan, Kaffayatullah; Saleem, Muhammad Umair; Khurram, Nauman; Niazi, Muhammad Umar Khan

    2017-06-11

    In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD) and granite sludge (GS), respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days) containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD), fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures) and curing moisture (continuously moist and partially moist followed by air curing). Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM) and mortar containing fly ash (FA). The test results indicated that under normal curing (20 °C, moist cured), the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations) remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more) incorporating local environmental conditions.

  19. The Predictive Utility of Early Childhood Disruptive Behaviors for School-Age Social Functioning

    PubMed Central

    Shaw, Daniel S.; Dishion, Thomas J.; Wilson, Melvin N.

    2016-01-01

    Research suggests that school-age children with disruptive behavior (DB) problems frequently demonstrate impaired social skills and experience rejection from peers, which plays a crucial role in the pathway to more serious antisocial behavior. A critical question is which DB problems in early childhood are prognostic of impaired social functioning in school-age children. This study examines the hypothesis that aggression in early childhood will be the more consistent predictor of compromised social functioning than inattentive, hyperactive-impulsive, or oppositional behavior. Participants included an ethnically diverse sample of 725 high-risk children from 3 geographically distinct areas followed from ages 2 to 8.5. Four latent growth models of DB from child ages 2 to 5, and potential interactions between dimensions, were used to predict latent parent and teacher ratings of school-age social dysfunction. Analyses were conducted in a multi-group format to examine potential differences between intervention and control group participants. Results showed that age 2 aggression was the DB problem most consistently associated with both parent- and teacher-rated social dysfunction for both groups. Early starting aggressive behavior may be particularly important for the early identification of children at risk for school-age social difficulties. PMID:25526865

  20. The Predictive Utility of Early Childhood Disruptive Behaviors for School-Age Social Functioning.

    PubMed

    Brennan, Lauretta M; Shaw, Daniel S; Dishion, Thomas J; Wilson, Melvin N

    2015-08-01

    Research suggests that school-age children with disruptive behavior (DB) problems frequently demonstrate impaired social skills and experience rejection from peers, which plays a crucial role in the pathway to more serious antisocial behavior. A critical question is which DB problems in early childhood are prognostic of impaired social functioning in school-age children. This study examines the hypothesis that aggression in early childhood will be the more consistent predictor of compromised social functioning than inattentive, hyperactive-impulsive, or oppositional behavior. Participants included an ethnically diverse sample of 725 high-risk children from 3 geographically distinct areas followed from ages 2 to 8.5. Four latent growth models of DB from child ages 2 to 5, and potential interactions between dimensions, were used to predict latent parent and teacher ratings of school-age social dysfunction. Analyses were conducted in a multi-group format to examine potential differences between intervention and control group participants. Results showed that age 2 aggression was the DB problem most consistently associated with both parent- and teacher-rated social dysfunction for both groups. Early starting aggressive behavior may be particularly important for the early identification of children at risk for school-age social difficulties.

  1. Birth weight, early childhood growth and lung function in middle to early old age: 1946 British birth cohort.

    PubMed

    Cai, Yutong; Shaheen, Seif O; Hardy, Rebecca; Kuh, Diana; Hansell, Anna L

    2016-10-01

    Findings from previous studies investigating the relationship between birth weight and adult lung function have been inconsistent, and data on birth weight and adult lung function decline are lacking. Few studies have investigated the relation between early childhood growth and adult lung function. FEV1 and FVC were measured at ages 43 years, 53 years and 60-64 years in the 1946 British birth cohort study. Multiple linear regression models were fitted to study associations with birth weight and weight gain at age 0-2 years. Multilevel models assessed how associations changed with age, with FEV1 and FVC as repeated outcomes. 3276 and 3249 participants were included in FEV1 and FVC analyses, respectively. In women, there was a decreasing association between birth weight and FVC with age. From the multilevel model, for every 1 kg higher birth weight, FVC was higher on average by 66.3 mL (95% CI 0.5 to 132) at 43 years, but significance was lost at 53 years and 60-64 years. Similar associations were seen with FEV1, but linear change (decline) from age 43 years lost statistical significance after full adjustment. In men, associations with birth weight were null in multilevel models. Higher early life weight gain was associated with higher FEV1 at age 43 years in men and women combined but not in each sex. Birth weight is positively associated with adult lung function in middle age, particularly in women, but the association diminishes with age, potentially due to accumulating environmental influences over the life course. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths

    SciTech Connect

    Jiao, Z. B.; Luan, J. H.; Miller, M. K.; Yu, C. Y.; Liu, C. T.

    2016-02-19

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. Lastly, the co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.

  3. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths

    DOE PAGES

    Jiao, Z. B.; Luan, J. H.; Miller, M. K.; ...

    2016-02-19

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for twomore » interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. Lastly, the co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.« less

  4. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths.

    PubMed

    Jiao, Z B; Luan, J H; Miller, M K; Yu, C Y; Liu, C T

    2016-02-19

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. The co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.

  5. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths

    PubMed Central

    Jiao, Z. B.; Luan, J. H.; Miller, M. K.; Yu, C. Y.; Liu, C. T.

    2016-01-01

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. The co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications. PMID:26892834

  6. Influence of core thickness and artificial aging on the biaxial flexural strength of different all-ceramic materials: An in-vitro study.

    PubMed

    Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

    2017-05-31

    The purpose of this study was to investigate the flexural strength of all-ceramics with varying core thicknesses submitted to aging. In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K) (n=40), were selected. Each group contained two core groups based on the core thickness as follows: IC/0.5, IC/0.8, EM/0.5, EM/0.8, K/0.5 and K/0.8 mm in thickness (n=20 each). Ten specimens from each group were subjected to aging and all specimens were tested for strength in a testing machine either with or without being subjected aging. The mean strength of the K were higher (873.05 MPa) than that of the IC (548.28 MPa) and EM (374.32 MPa) regardless of core thickness. Strength values increased with increasing core thickness for all IC, EM and K regardless of aging. Results of this study concluded that strength was not significantly affected by aging. Different core thicknesses affected strength of the all-ceramic materials tested (p<0.05).

  7. Effect of heat treatment and aging on the mechanical loss and strength of hydroxide catalysis bonds between fused silica samples

    NASA Astrophysics Data System (ADS)

    Haughian, K.; van Veggel, A. A.; Cunningham, L.; Hough, J.; Murray, P. G.; Reid, S.; Rowan, S.

    2017-08-01

    Hydroxide catalysis bonds are used in the aLIGO gravitational wave detectors and are an essential technology within the mirror suspensions that allowed detector sensitivities to be reached, which enabled the first direct detections of gravitational waves. Methods aimed at further improving hydroxide catalysis bonds for future upgrades to these detectors, in order to increase detection rates and the number of detectable sources, are explored. Also, the effect on the bonds of an aLIGO suspension construction procedure involving heat, the fiber welding process, is investigated. Here we show that thermal treatments can be beneficial to improving some of the bond properties important to the mirror suspensions in interferometric gravitational wave detectors. It was found that heat treating bonds at 150 °C increases bond strength by a factor of approximately 1.5 and a combination of bond aging and heat treatment of the optics at 150 °C reduces the mechanical loss of a bond from 0.10 to 0.05. It is also shown that current construction procedures do not reduce bond strength.

  8. Shear-bond-strength of orthodontic brackets to aged nano-hybrid composite-resin surfaces using different surface preparation.

    PubMed

    Demirtas, Hatice Kubra; Akin, Mehmet; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-01-01

    The aim of this study was to evaluate the effects of different surface preparation methods on the shear bond strength (SBS) of orthodontic metal brackets to aged nano-hybrid resin composite surfaces in vitro. A total of 100 restorative composite resin discs, 6 mm in diameter and 3 mm thick, were obtained and treated with an ageing procedure. After ageing, the samples were randomly divided as follows according to surface preparation methods: (1)Control, (2)37% phosphoric acid gel, (3)Sandblasting, (4)Diamond bur, (5)Air-flow and 20 central incisor teeth were used for the control etched group. SBS test were applied on bonded metal brackets to all samples. SBS values and residual adhesives were evaluated. Analysis of variance showed a significant difference (p<0.001) between the groups. Sandblasted group had the highest SBS value (12.85 MPa) in experimental groups. The sandblasting surface treatment is recommended as an effective method of bonding orthodontic metal brackets to nano-hybrid composite resin surfaces.

  9. Early-life stress and reproductive cost: A two-hit developmental model of accelerated aging?

    PubMed

    Shalev, Idan; Belsky, Jay

    2016-05-01

    Two seemingly independent bodies of research suggest a two-hit model of accelerated aging, one highlighting early-life stress and the other reproduction. The first, informed by developmental models of early-life stress, highlights reduced longevity effects of early adversity on telomere erosion, whereas the second, informed by evolutionary theories of aging, highlights such effects with regard to reproductive cost (in females). The fact that both early-life adversity and reproductive effort are associated with shorter telomeres and increased oxidative stress raises the prospect, consistent with life-history theory, that these two theoretical frameworks currently informing much research are tapping into the same evolutionary-developmental process of increased senescence and reduced longevity. Here we propose a mechanistic view of a two-hit model of accelerated aging in human females through (a) early-life adversity and (b) early reproduction, via a process of telomere erosion, while highlighting mediating biological embedding mechanisms that might link these two developmental aging processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Caloric restriction preserves memory and reduces anxiety of aging mice with early enhancement of neurovascular functions

    PubMed Central

    Parikh, Ishita; Guo, Janet; Chuang, Kai-Hsiang; Zhong, Yu; Rempe, Ralf G.; Hoffman, Jared D.; Armstrong, Rachel; Bauer, Björn; Hartz, Anika M.S.; Lin, Ai-Ling

    2016-01-01

    Neurovascular integrity plays an important role in protecting cognitive and mental health in aging. Lifestyle interventions that sustain neurovascular integrity may thus be critical on preserving brain functions in aging and reducing the risk for age-related neurodegenerative disorders. Here we show that caloric restriction (CR) had an early effect on neurovascular enhancements, and played a critical role in preserving vascular, cognitive and mental health in aging. In particular, we found that CR significantly enhanced cerebral blood flow (CBF) and blood-brain barrier function in young mice at 5-6 months of age. The neurovascular enhancements were associated with reduced mammalian target of rapamycin expression, elevated endothelial nitric oxide synthase signaling, and increased ketone bodies utilization. With age, CR decelerated the rate of decline in CBF. The preserved CBF in hippocampus and frontal cortex were highly correlated with preserved memory and learning, and reduced anxiety, of the aging mice treated with CR (18-20 months of age). Our results suggest that dietary intervention started in the early stage (e.g., young adults) may benefit cognitive and mental reserve in aging. Understanding nutritional effects on neurovascular functions may have profound implications in human brain aging and age-related neurodegenerative disorders. PMID:27829242

  11. Early Aging Effect on the Function of the Human Central Olfactory System.

    PubMed

    Wang, Jianli; Sun, Xiaoyu; Yang, Qing X

    2017-08-01

    During normal aging process, the smell function declines significantly, starting from the sixth decade of age. While it has been shown that activity in the central olfactory system of seniors responding to odor stimulation is significantly less than that of young people, no information of the aging effect on the functions of this system during normal adulthood and early aging has been gathered. In this study, we used functional magnetic resonance imaging to investigate the olfaction-related brain activity in the central olfactory structures of 43 healthy adult volunteers aged from 22 to 64 years. The participants' smell identification function was negatively correlated with age (r = -.32, p = .037). Significant negative correlation was observed between age and the olfaction-related activities in the bilateral dorsolateral prefrontal cortex, left insular cortex, and left orbitofrontal cortex (p < .001, corrected with cluster size ≥28 voxels). There was no significant correlation observed between age and the activity in the primary olfactory cortex detected in this age group. These results suggest that age-related functional decline in the human brain is more prominent in the secondary and higher-order central olfactory structures than the primary olfactory cortex in the early aging process. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Behavioural early-life exposures and body composition at age 15 years.

    PubMed

    Leary, S D; Lawlor, D A; Davey Smith, G; Brion, M J; Ness, A R

    2015-02-09

    Previous studies have demonstrated associations between some early-life exposures and later obesity, but most have used body mass index in childhood or adulthood as the outcome. The objective of this study was to investigate whether early-life exposures were associated with directly measured fat and lean mass in adolescence. This study used data on 4750 mother-offspring pairs, collected as a part of the Avon Longitudinal Study of Parents and Children, Bristol, UK between 1991 and 1992; associations between behavioural exposures occurring from conception up to 5 years of age (maternal and paternal smoking during pregnancy, breastfeeding, age at introduction to solids, dietary patterns and physical inactivity during early childhood) and offspring body composition measured by dual-energy X-ray absorptiometry at ~15 years were assessed. After full adjustment for potential confounders, maternal smoking during pregnancy, having a junk food diet and spending more time watching television in early childhood were all associated with higher fat mass at age 15, whereas maternal smoking, having a healthy diet and playing computer games more frequently in early childhood were all associated with a higher lean mass at age 15. Associations with paternal smoking were generally weaker for both fat and lean mass, but as there was no strong statistical evidence for maternal vs paternal differences, confounding by social factors rather than a direct effect of maternal smoking cannot be ruled out. Early feeding was not associated with fat or lean mass at age 15. This study does not provide compelling evidence for associations between most early-life factors and body composition in adolescence. However, possible associations with dietary patterns and physical inactivity in early childhood require further investigation in other cohorts that have direct measurements of adolescent body composition.

  13. Rewriting the Central European Early Bronze Age Chronology: Evidence from Large-Scale Radiocarbon Dating.

    PubMed

    Stockhammer, Philipp W; Massy, Ken; Knipper, Corina; Friedrich, Ronny; Kromer, Bernd; Lindauer, Susanne; Radosavljević, Jelena; Wittenborn, Fabian; Krause, Johannes

    2015-01-01

    The transition from the Neolithic to the Early Bronze Age in Central Europe has often been considered as a supra-regional uniform process, which led to the growing mastery of the new bronze technology. Since the 1920s, archaeologists have divided the Early Bronze Age into two chronological phases (Bronze A1 and A2), which were also seen as stages of technical progress. On the basis of the early radiocarbon dates from the cemetery of Singen, southern Germany, the beginning of the Early Bronze Age in Central Europe was originally dated around 2300/2200 BC and the transition to more complex casting techniques (i.e., Bronze A2) around 2000 BC. On the basis of 140 newly radiocarbon dated human remains from Final Neolithic, Early and Middle Bronze Age cemeteries south of Augsburg (Bavaria) and a re-dating of ten graves from the cemetery of Singen, we propose a significantly different dating range, which forces us to re-think the traditional relative and absolute chronologies as well as the narrative of technical development. We are now able to date the beginning of the Early Bronze Age to around 2150 BC and its end to around 1700 BC. Moreover, there is no transition between Bronze (Bz) A1 and Bronze (Bz) A2, but a complete overlap between the type objects of the two phases from 1900-1700 BC. We thus present a revised chronology of the assumed diagnostic type objects of the Early Bronze Age and recommend a radiocarbon-based view on the development of the material culture. Finally, we propose that the traditional phases Bz A1 and Bz A2 do not represent a chronological sequence, but regionally different social phenomena connected to the willingness of local actors to appropriate the new bronze technology.

  14. Rewriting the Central European Early Bronze Age Chronology: Evidence from Large-Scale Radiocarbon Dating

    PubMed Central

    Knipper, Corina; Friedrich, Ronny; Kromer, Bernd; Lindauer, Susanne; Radosavljević, Jelena; Wittenborn, Fabian; Krause, Johannes

    2015-01-01

    The transition from the Neolithic to the Early Bronze Age in Central Europe has often been considered as a supra-regional uniform process, which led to the growing mastery of the new bronze technology. Since the 1920s, archaeologists have divided the Early Bronze Age into two chronological phases (Bronze A1 and A2), which were also seen as stages of technical progress. On the basis of the early radiocarbon dates from the cemetery of Singen, southern Germany, the beginning of the Early Bronze Age in Central Europe was originally dated around 2300/2200 BC and the transition to more complex casting techniques (i.e., Bronze A2) around 2000 BC. On the basis of 140 newly radiocarbon dated human remains from Final Neolithic, Early and Middle Bronze Age cemeteries south of Augsburg (Bavaria) and a re-dating of ten graves from the cemetery of Singen, we propose a significantly different dating range, which forces us to re-think the traditional relative and absolute chronologies as well as the narrative of technical development. We are now able to date the beginning of the Early Bronze Age to around 2150 BC and its end to around 1700 BC. Moreover, there is no transition between Bronze (Bz) A1 and Bronze (Bz) A2, but a complete overlap between the type objects of the two phases from 1900–1700 BC. We thus present a revised chronology of the assumed diagnostic type objects of the Early Bronze Age and recommend a radiocarbon-based view on the development of the material culture. Finally, we propose that the traditional phases Bz A1 and Bz A2 do not represent a chronological sequence, but regionally different social phenomena connected to the willingness of local actors to appropriate the new bronze technology. PMID:26488413

  15. Early-late life trade-offs and the evolution of ageing in the wild.

    PubMed

    Lemaître, Jean-François; Berger, Vérane; Bonenfant, Christophe; Douhard, Mathieu; Gamelon, Marlène; Plard, Floriane; Gaillard, Jean-Michel

    2015-05-07

    Empirical evidence for declines in fitness components (survival and reproductive performance) with age has recently accumulated in wild populations, highlighting that the process of senescence is nearly ubiquitous in the living world. Senescence patterns are highly variable among species and current evolutionary theories of ageing propose that such variation can be accounted for by differences in allocation to growth and reproduction during early life. Here, we compiled 26 studies of free-ranging vertebrate populations that explicitly tested for a trade-off between performance in early and late life. Our review brings overall support for the presence of early-late life trade-offs, suggesting that the limitation of available resources leads individuals to trade somatic maintenance later in life for high allocation to reproduction early in life. We discuss our results in the light of two closely related theories of ageing-the disposable soma and the antagonistic pleiotropy theories-and propose that the principle of energy allocation roots the ageing process in the evolution of life-history strategies. Finally, we outline research topics that should be investigated in future studies, including the importance of natal environmental conditions in the study of trade-offs between early- and late-life performance and the evolution of sex-differences in ageing patterns.

  16. INEQUITY ISSUES AND MOTHERS' PREGNANCY, DELIVERY AND EARLY-AGE SURVIVAL EXPERIENCES IN ENDE DISTRICT, INDONESIA.

    PubMed

    Pardosi, Jerico Franciscus; Parr, Nick; Muhidin, Salut

    2015-11-01

    Indonesia's infant mortality rates are among the highest in South-East Asia, and there are substantial variations between its sub-national regions. This qualitative study aims to explore early mortality-related health service provision and gender inequity issues based on mothers' pregnancy, delivery and early-age survival experience in Ende district, Nusa Tenggara Timur province. Thirty-two mothers aged 18-45 years with at least one birth in the previous five years were interviewed in depth in May 2013. The results show most mothers have little knowledge about the danger signs for a child's illness. Mothers with early-age deaths generally did not know the cause of death. Very few mothers had received adequate information on maternal and child health during their antenatal and postnatal visits to the health facility. Some mothers expressed a preference for using a traditional birth attendant, because of their ready availability and the more extensive range of support services they provide, compared with local midwives. Unprofessional attitudes displayed by midwives were reported by several mothers. As elsewhere in Indonesia, the power of health decision-making lies with the husband. Policies aimed at elevating mothers' roles in health care decision-making are discussed as measures that would help to improve early-age survival outcomes. Widening the public health insurance distribution, especially among poorer mothers, and equalizing the geographical distribution of midwives and health facilities are recommended to tackle geographical inequities and to increase early-age survival in Ende district.

  17. Coercive Family Process and Early-Onset Conduct Problems From Age 2 to School Entry

    PubMed Central

    Smith, Justin D.; Dishion, Thomas J.; Shaw, Daniel S.; Wilson, Melvin N.; Winter, Charlotte C.; Patterson, Gerald R.

    2013-01-01

    The emergence and persistence of conduct problems during early childhood is a robust predictor of behavior problems in school and future maladaptation. In this study we examined the reciprocal influences between observed coercive interactions between children and caregivers, oppositional and aggressive behavior, and growth in parent report of early childhood (ages 2–5) and school-age conduct problems (age 7.5 and 8.5). Participants were drawn from the Early Steps multisite randomized prevention trial that includes an ethnically diverse sample of male and female children and their families (N = 731). A parallel process growth model combining latent trajectory and cross-lagged approaches revealed the amplifying effect of observed coercive caregiver–child interactions on children's noncompliance, whereas child oppositional and aggressive behaviors did not consistently predict increased coercion. The slope and initial levels of child oppositional and aggressive behaviors and the stability of caregiver–child coercion were predictive of teacher-reported oppositional behavior at school age. Families assigned to the Family Check-Up condition had significantly steeper declines in child oppositional and aggressive behavior and moderate reductions in oppositional behavior in school and in coercion at age 3. Results were not moderated by child gender, race/ethnicity, or assignment to the intervention condition. The implications of these findings are discussed with respect to understanding the early development of conduct problems and to designing optimal strategies for reducing problem behavior in early childhood with families most in need. PMID:24690305

  18. Coercive family process and early-onset conduct problems from age 2 to school entry.

    PubMed

    Smith, Justin D; Dishion, Thomas J; Shaw, Daniel S; Wilson, Melvin N; Winter, Charlotte C; Patterson, Gerald R

    2014-11-01

    The emergence and persistence of conduct problems (CPs) during early childhood is a robust predictor of behavior problems in school and of future maladaptation. In this study we examined the reciprocal influences between observed coercive interactions between children and caregivers, oppositional and aggressive behavior, and growth in parent report of early childhood (ages 2-5) and school-age CPs (ages 7.5 and 8.5). Participants were drawn from the Early Steps multisite randomized prevention trial that includes an ethnically diverse sample of male and female children and their families (N = 731). A parallel-process growth model combining latent trajectory and cross-lagged approaches revealed the amplifying effect of observed coercive caregiver-child interactions on children's noncompliance, whereas child oppositional and aggressive behaviors did not consistently predict increased coercion. The slope and initial levels of child oppositional and aggressive behaviors and the stability of caregiver-child coercion were predictive of teacher-reported oppositional behavior at school age. Families assigned to the Family Check-Up condition had significantly steeper declines in child oppositional and aggressive behavior and moderate reductions in oppositional behavior in school and in coercion at age 3. Results were not moderated by child gender, race/ethnicity, or assignment to the intervention condition. The implications of these findings are discussed with respect to understanding the early development of CPs and to designing optimal strategies for reducing problem behavior in early childhood with families most in need.

  19. Investigating the early stages of person perception: the asymmetry of social categorization by sex vs. age.

    PubMed

    Cloutier, Jasmin; Freeman, Jonathan B; Ambady, Nalini

    2014-01-01

    Early perceptual operations are central components of the dynamics of social categorization. The wealth of information provided by facial cues presents challenges to our understanding of these early stages of person perception. The current study aimed to uncover the dynamics of processing multiply categorizable faces, notably as a function of their gender and age. Using a modified four-choice version of a mouse-tracking paradigm (which assesses the relative dominance of two categorical dimensions), the relative influence that sex and age have on each other during categorization of infant, younger adult, and older adult faces was investigated. Results of these experiments demonstrate that when sex and age dimensions are simultaneously categorized, only for infant faces does age influence sex categorization. In contrast, the sex of both young and older adults was shown to influence age categorization. The functional implications of these findings are discussed in light of previous person perception research.

  20. Age dependent hypergastrinaemia in children with Helicobacter pylori gastritis--evidence of early acquisition of infection.

    PubMed Central

    McCallion, W A; Ardill, J E; Bamford, K B; Potts, S R; Boston, V E

    1995-01-01

    Acute Helicobacter pylori associated gastritis causes achlorhydria, a powerful stimulus to gastrin secretion. If H pylori infection is acquired primarily in early childhood, then the degree of hypergastrinaemia in seropositive children should be age dependent. Anti-Helicobacter antibodies and fasting gastrin concentrations were measured in 439 children aged 4 to 13 years attending hospital for routine day case surgery not connected with any gastrointestinal disorder. Thirty per cent were seropositive for H pylori. There was an inverse relationship between the fasting gastrin concentration and age; the mean fasting gastrin in children aged 4-5 years, 155 ng/l, was significantly higher than that seen in children aged 12-13 years, 90 ng/l. The more noticeable hypergastrinaemia seen in young children with H pylori associated gastritis may reflect achlorhydria associated with acute H pylori infection and suggests that this is primarily acquired in early childhood. PMID:7672676

  1. Early gestational age at preeclampsia onset is associated with subclinical atherosclerosis 12 years after delivery.

    PubMed

    Christensen, Martin; Kronborg, Camilla Skovhus; Carlsen, Rasmus Kirkeskov; Eldrup, Nikolaj; Knudsen, Ulla Breth

    2017-09-01

    Women with a history of preeclampsia have increased risk of cardiovascular disease later in life. However, it is unclear whether early gestational age at preeclampsia onset is associated with higher cardiovascular disease risk. This study aimed to test the association between gestational age at preeclampsia onset (including the early-onset/late-onset preeclampsia distinction) and subclinical atherosclerosis and arterial stiffness in age-matched women 12 years after index pregnancy. Eligible participants were identified in two Danish registries. Main outcome measures were carotid plaque presence, carotid intima-media thickness, aortic pulse wave velocity, and augmentation index adjusted for heart rate. Twenty-four women with previous early-onset preeclampsia, 24 with previous late-onset preeclampsia and 24 with previous normotensive pregnancies were included after matching on age (±2 years) and time since delivery (±1 year). In all outcome measures, the early-onset group had the highest percentage or mean value. In the adjusted analysis, the early-onset group significantly differed from the late-onset group in all outcome measures except aortic pulse wave velocity. The early-onset group also had significantly higher carotid intima-media thickness (average and left) compared with the normotensive group. Gestational age at preeclampsia onset as a continuous variable was significantly associated to both carotid plaque presence and carotid intima-media thickness (average and right). Gestational age at preeclampsia onset is negatively associated with markers of subclinical atherosclerosis 12 years after delivery. Potentially, gestational age at preeclampsia onset might be helpful in directing cardiovascular disease prevention after preeclampsia. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

  2. Early Postnatal Hypotension and Developmental Delay at 24 Months of Age among Extremely Low Gestational Age Newborns

    PubMed Central

    Logan, J. Wells; O’Shea, T. Michael; Allred, Elizabeth N.; Laughon, Matthew M.; Bose, Carl L.; Dammann, Olaf; Batton, Daniel G.; Engelke, Stephen C.; Leviton, Alan

    2016-01-01

    Objectives To evaluate, in extremely low gestational age newborns (ELGANs), relationships between indicators of hypotension during the first 24 postnatal hours and developmental delay at 24 months of age. Methods The 945 infants in this prospective study were born at < 28 weeks, were assessed for 3 indicators of hypotension in the first 24 postnatal hours, and were evaluated with the Bayley Mental Development Index (MDI) and Psychomotor Development Index (PDI) at 24 months corrected age. Indicators of hypotension included: 1) mean arterial pressure (MAP) in the lowest quartile for gestational age; 2) treatment with a vasopressor; and 3) blood pressure lability, defined as the upper quartile for the difference between the lowest and highest MAP. Logistic regression was used to evaluate relationships between hypotension and developmental outcomes, adjusting for potential confounders. Results 26% of the cohort had an MDI < 70 and 32% had a PDI < 70. Low MDI and PDI were significantly associated with low gestational age, which in turn, was associated with receipt of vasopressor treatment. Blood pressure in the lowest quartile for gestational age was associated with vasopressor treatment and labile blood pressure. After adjusting for potential confounders, none of the indicators of hypotension was associated with MDI < 70 or PDI < 70. Conclusions In this large cohort of ELGANs, we found little evidence that early postnatal hypotension is associated with developmental delay at 24 months corrected gestational age. PMID:21138828

  3. Does socio-economic status predict grip strength in older Europeans? Results from the SHARE study in non-institutionalised men and women aged 50+.

    PubMed

    Mohd Hairi, Farizah; Mackenbach, Johan P; Andersen-Ranberg, K; Avendano, Mauricio

    2010-09-01

    Reduced hand-grip strength predicts disability, morbidity and mortality, but whether it is shaped by socio-economic experiences is yet unknown. The authors examined the association of education, occupation, income and wealth with grip strength in older Europeans. Data came from the Survey of Health, Ageing and Retirement in Europe comprising 27 351 participants ages 50+ in 11 countries. Grip strength was objectively measured using a handheld dynamometer. Estimates were obtained based on multivariate linear regression controlling for a wide set of confounders, demographics, health and disability measures, and behavioural risk factors. In the total sample, education, occupational class, income and wealth predicted grip strength among men, whereas only education and wealth predicted grip strength among women. While education and income effects were inconsistent in most countries, wealth consistently predicted grip strength in each country. A one-point increase in the log of wealth was associated with 0.38 kg (95% CI 0.31 to 0.45) higher grip strength in men and 0.18 kg (95% CI 0.15 to 0.21) higher grip strength in women. While education, income and occupation effects disappeared after adjustment for health measures, log of wealth effects remained significant in both men (0.22, 95% CI 0.15 to 0.29) and women (0.08, 95% CI 0.05 to 0.11). Wealth effects were particularly evident in the two lowest quintiles. Old-age socio-economic and financial circumstances as measured by wealth are associated with grip strength, particularly among the least wealthy, while circumstances defined earlier in life as measured by education, income and occupation do not consistently predict grip strength.

  4. Normal values for handgrip strength in 920 men and women aged over 65 years, and longitudinal changes over 4 years in 620 survivors.

    PubMed

    Bassey, E J; Harries, U J

    1993-03-01

    1. The maximal grip strength of the hand has been measured in a random sample of 359 men and 561 women aged over 65 years living in their own homes. The response rate was 80% from a representative demographic area of the U.K. Measurements were made of body mass, skeletal size (demispan) and grip strength. Grip strength was measured using a custom-built strain-gauged dynamometer. The best of three attempts was taken as definitive. A structured questionnaire was used to obtain information about customary activity, use of handgrip muscles, health and psychological well-being. This was repeated with 620 survivors 4 years later. 2. The results for strength were normally distributed. The right hand was 10% stronger than the left and men had twice the strength of women. Strength was significantly related to skeletal size and in men to body mass. The gender difference was only partly accounted for by skeletal size and women were substantially disadvantaged in terms of their strength/body mass ratio. 3. There was a significant decline in strength with age of 2%/year for men and women. Strength was also significantly related to customary activity, reported use of the hands and psychological and physical health. 4. After 4 years 620 survivors were re-measured. Grip strength had declined by 12% in men and 19% in women and these losses were significantly related to age. A significant decline was also found in reported use, customary activity and health scores, and in women in body mass and psychological health.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Life course influences on quality of life in early old age.

    PubMed

    Blane, D; Higgs, P; Hyde, M; Wiggins, R D

    2004-06-01

    A growing literature demonstrates life course influences on health in early old age. The present paper is the first to examine whether similar processes also influence quality of life in early old age. The question is theorised in terms of structured dependency and third age, and the life course pathways by which people arrive at these destinations in later life. The issues are investigated in a unique data set that contains health and life course information on some 300 individuals mostly aged 65-75 years, enhanced in 2000 by postal survey data on quality of life. Several types of life course effect are identified at conventional levels of statistical significance. Long-term influences on quality of life, however, are less marked than those on health. Quality of life in early old age appears to be influenced primarily by current contextual factors such as material circumstances and serious health problems, with the influence of the life course limited mostly to its shaping of an individual's circumstances in later life. The implication for policy is that disadvantage during childhood and adulthood does not preclude good quality of life in early old age.

  6. Adaptive Changes of Myosin Isoforms in Response to Long-Term Strength and Power Training in Middle-Aged Men

    PubMed Central

    Puhke, Raivo; Aunola, Sirkka; Ailanto, Pirjo; Alev, Karin; Venojärvi, Mika; Rusko, Heikki; Seene, Teet

    2006-01-01

    The purpose of the study was to examine the adaptive changes in myosin heavy chain (MHC) and light chain (MLC) isoforms in human vastus lateralis muscle caused by long-term strength and power training (54 weeks, approximately 3 times a week) in untrained middle- aged men (16 in the training and 6 in the control group). Muscular MHC and MLC isoforms were determined by means of SDS-PAGE gel electrophoresis. During the training period, maximal anaerobic cycling power increased by 64 W (p < 0.001) and the maximal jumping height by 1.5 cm (p < 0. 05) in the training group, but no significant changes were found in the control group. However, the group by time effect was not significant. In the training group, the increase of the maximal jumping height correlated with the number of strength and power training sessions (r = 0.56; p < 0.05). The change of the proportion of MHC IIa isoform from 52.6 ± 12.2% to 59.4 ± 11.6% did not reach statistical significance (p = 0.070 for group by time; within training group p = 0.061) and neither did the change of the proportion of MHC IIx isoform from 18.1 ± 11.4% to 11.1 ± 9.1% (p = 0.104 for group by time; within training group p=0.032). The degree of change of MHC IIx isoform correlated with the amount of earlier recreational sports activity (r = 0.61; p < 0.05). In the training group, the changes of MLC1s isoform correlated negatively with the changes of MLC1f isoform (r = -0. 79; p < 0.05) as well as with the changes in maximal anaerobic cycling power (r = -0.81; p < 0.05), and positively with those of MHC I isoform (r = 0.81; p < 0.05). In conclusion, the long- term strength and power training ~3 times a week seemed to have only slight effects on fast MHC isoforms in the vastus lateralis muscle of untrained middle-aged men; the proportion of MHC IIa tended to increase and that of MHC IIx tended to decrease. No changes in MLC isoform profile could be shown. Key Points A long-term strength and power training program seemed to

  7. Early middle ear effusion and school achievement at age seven years.

    PubMed

    McCormick, David P; Johnson, Dale L; Baldwin, Constance D

    2006-01-01

    This study tested the hypothesis that children with early persistent middle ear effusion (MEE) are at risk for later deficits in academic performance. We recruited 698 newborns and monitored them for MEE every 2 to 4 weeks at home until age 3 years. At age 7 years, it was possible to obtain school data for 226 children. Tests included the Iowa Tests of Basic Skills or the Stanford Achievement tests, the Woodcock Reading Mastery Tests, and the Woodcock-Johnson Tests of Achievement. There was no significant relationship between early MEE and measures of school achievement as shown by correlations or multiple regression. Differences between extreme MEE groups were not significant. School achievement was strongly associated with ethnicity, home environment, and socioeconomic status. Early persistent MEE does not appear to affect achievement in school at age 7 years.

  8. Tracking development from early speech-language acquisition to reading skills at age 13.

    PubMed

    Bartl-Pokorny, Katrin D; Marschik, Peter B; Sachse, Steffi; Green, Vanessa A; Zhang, Dajie; Van Der Meer, Larah; Wolin, Thomas; Einspieler, Christa

    2013-06-01

    Previous studies have indicated a link between speech-language and literacy development. To add to this body of knowledge, we investigated whether lexical and grammatical skills from toddler to early school age are related to reading competence in adolescence. Twenty-three typically developing children were followed from age 1;6 to 13;6 (years;months). Parental checklists and standardized tests were used to assess the development of mental lexicon, grammatical and reading capacities of the children. Direct assessment of early speech-language functions positively correlated with later reading competence, whereas lexical skills reported by parents were not associated with this capacity. At (pre-) school age, larger vocabulary and better grammatical abilities predicted advanced reading abilities in adolescence. Our study contributes to the understanding of typical speech-language development and its relation to later reading outcome, extending the body of knowledge on these developmental domains for future early identification of children at risk for reading difficulties.

  9. Viking and early Middle Ages northern Scandinavian textiles proven to be made with hemp.

    PubMed

    Skoglund, G; Nockert, M; Holst, B

    2013-10-18

    Nowadays most plant textiles used for clothing and household are made of cotton and viscose. Before the 19th century however, plant textiles were mainly made from locally available raw materials, in Scandinavia these were: nettle, hemp and flax. It is generally believed that in Viking and early Middle Ages Scandinavia hemp was used only for coarse textiles (i.e. rope and sailcloth). Here we present an investigation of 10 Scandinavian plant fibre textiles from the Viking and Early Middle Ages, believed to be locally produced. Up till now they were all believed to be made of flax. We show that 4 textiles, including two pieces of the famous Överhogdal Viking wall-hanging are in fact made with hemp (in three cases hemp and flax are mixed). This indicates that hemp was important, not only for coarse but also for fine textile production in Viking and Early Middle Ages in Scandinavia.

  10. The influence of living conditions in early life on life satisfaction in old age.

    PubMed

    Deindl, Christian

    2013-03-01

    This article examines the influence of living conditions in early life on life satisfaction in old age in eleven Western European countries. It combines the influence of individual conditions, for example housing and family background, with country characteristics in the decade of birth. Using pooled data from the second and third wave of the Survey of Health, Ageing and Retirement in Europe, multilevel models show that early life living conditions have an influence on life satisfaction in old age. Furthermore, interaction effects between current and past living conditions show that adverse living conditions strengthen the effect of early life on life satisfaction in later life and therefore are an indication of cumulative inequality over the life course. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Viking and Early Middle Ages Northern Scandinavian Textiles Proven to be made with Hemp

    NASA Astrophysics Data System (ADS)

    Skoglund, G.; Nockert, M.; Holst, B.

    2013-10-01

    Nowadays most plant textiles used for clothing and household are made of cotton and viscose. Before the 19th century however, plant textiles were mainly made from locally available raw materials, in Scandinavia these were: nettle, hemp and flax. It is generally believed that in Viking and early Middle Ages Scandinavia hemp was used only for coarse textiles (i.e. rope and sailcloth). Here we present an investigation of 10 Scandinavian plant fibre textiles from the Viking and Early Middle Ages, believed to be locally produced. Up till now they were all believed to be made of flax. We show that 4 textiles, including two pieces of the famous Överhogdal Viking wall-hanging are in fact made with hemp (in three cases hemp and flax are mixed). This indicates that hemp was important, not only for coarse but also for fine textile production in Viking and Early Middle Ages in Scandinavia.

  12. Early Impacts on the Moon: Crystallization Ages of Apollo 16 Melt Breccias

    NASA Technical Reports Server (NTRS)

    Norman, M. D.; Shih, C.-Y.; Nyquist, L. E.; Bogard, D. D.; Taylor, L. A.

    2007-01-01

    A better understanding of the early impact history of the terrestrial planets has been identified one of the highest priority science goals for solar system exploration. Crystallization ages of impact melt breccias from the Apollo 16 site in the central nearside lunar highlands show a pronounced clustering of ages from 3.75-3.95 Ga, with several impact events being recognized by the association of textural groups and distinct ages. Here we present new geochemical and petrologic data for Apollo 16 crystalline breccia 67955 that document a much older impact event with an age of 4.2 Ga.