Observations of Dynamic Strain Aging in Polycrystalline NiAl

NASA Technical Reports Server (NTRS)

Weaver, M. L.; Noebe, R. D.; Kaufman, M. J.

1996-01-01

Dynamic strain aging has been investigated at temperatures between 77 and 1100 K in eight polycrystalline NiAl alloys. The 0.2% offset yield stress and work hardening rates for these alloys generally decreased with increasing temperature. However, local plateaus or maxima were observed in conventional purity and carbon doped alloys at intermediate temperatures (600-900 K). This anomalous behavior was not observed in low interstitial high-purity, nitrogen doped, or in titanium doped materials. Low or negative strain rate sensitivities (SRS) were also observed in all eight alloys in this intermediate temperature range. Coincident with the occurrence of negative SRS was the occurrence of serrated flow in conventional purity alloys containing high concentrations of Si in addition to C. These phenomena have been attributed to dynamic strain aging (DSA). Chemical analysis of the alloys used in this study suggests that the main species causing strain aging in polycrystalline NiAl is C but indicate that residual Si impurities can enhance the strain aging effect.

Effects of C and Si on strain aging of strain-based API X60 pipeline steels

NASA Astrophysics Data System (ADS)

Sung, Hyo Kyung; Lee, Dong Ho; Lee, Sunghak; Lee, Byeong-Joo; Hong, Seung-Pyo; Kim, Young-Woon; Yoo, Jang Yong; Hwang, Byoungchul; Shin, Sang Yong

2017-05-01

Four types of strain-based API X60 pipeline steels were fabricated by varying the C and Si contents, and the effects of C and Si on strain aging were investigated. The 0.05 wt% C steels consisted mainly of polygonal ferrite (PF), whereas the 0.08 wt% C steels consisted of acicular ferrite (AF). The volume fraction of AF increased with increasing C content because C is an austenite stabilizer element. The volume fractions of bainitic ferrite (BF) of the 0.15 wt% Si steels were higher than those of the 0.25 wt% Si steels, whereas the volume fractions of the secondary phases were lower. From the tensile properties before and after the aging process of the strainbased API X60 pipeline steels, the yield strength increased and the uniform and total elongation decreased, which is the strain aging effect. The strain aging effect in the strain-based API X60 pipeline steels was minimized when the volume fraction of AF was increased and secondary phases were distributed uniformly. On the other hand, an excessively high C content formed fine precipitates, and the strain aging effect occurred because of the interactions among dislocations and fine precipitates.

Age- and strain-dependent differences in the outcome of experimental infections of domestic pigs with wild boar pseudorabies virus isolates.

PubMed

Verpoest, Sara; Cay, Ann Brigitte; Van Campe, Willem; Mostin, Laurent; Welby, Sarah; Favoreel, Herman; De Regge, Nick

2016-02-01

Although pseudorabies virus (PRV) has been eradicated in domestic swine in many countries, its presence in wild boars remains a threat for a reintroduction into the currently unprotected swine population. To assess the possible impact of such a reintroduction in a naive herd, an in vivo infection study using two genetically characterized wild boar PRV isolates (BEL24043 and BEL20075) representative for wild boar strains circulating in south-western and central Europe and the virulent NIA3 reference strain was performed in 2- and 15-week-old domestic pigs. Our study revealed an attenuated nature of both wild boar strains in 15-week-old pigs. In contrast, it showed the capacity of strain BEL24043 to induce severe clinical symptoms and mortality in young piglets, thereby confirming that the known age dependency of disease outcome after PRV infection also holds for wild boar isolates. Despite the absence of clinical disease in 15-week-old sows, both wild boar PRV strains were able to induce seroconversion, but to a different extent. Importantly, differences in infection and transmission capacity of both strains were observed in 15-week-old sows. Strain BEL24043 induced a more prolonged and disseminated infection than strain BEL20075 and was able to spread efficiently to contact animals, indicative of its capacity to induce a sustained infection. In conclusion, it was shown that a reintroduction of a wild boar isolate into the domestic swine population could have serious economic consequences due to the induction of clinical symptoms in piglets and by jeopardizing the PRV-negative status.

Effects of age-related differences in femoral loading and bone mineral density on strains in the proximal femur during controlled walking.

PubMed

Anderson, Dennis E; Madigan, Michael L

2013-10-01

Maintenance of healthy bone mineral density (BMD) is important for preventing fractures in older adults. Strains experienced by bone in vivo stimulate remodeling processes, which can increase or decrease BMD. However, there has been little study of age differences in bone strains. This study examined the relative contributions of age-related differences in femoral loading and BMD to age-related differences in femoral strains during walking using gait analysis, static optimization, and finite element modeling. Strains in older adult models were similar or larger than in young adult models. Reduced BMD increased strains in a fairly uniform manner, whereas older adult loading increased strains in early stance but decreased strains in late stance. Peak ground reaction forces, hip joint contact forces, and hip flexor forces were lower in older adults in late stance phase, and this helped older adults maintain strains similar to those of young adults despite lower BMD. Because walking likely represents a "baseline" level of stimulus for bone remodeling processes, increased strains during walking in older adults might indicate the extent of age-related impairment in bone remodeling processes. Such a measure might be clinically useful if it could be accurately determined with age-appropriate patient-specific loading, geometry, and BMD.

Dynamic strain aging in stress controlled creep-fatigue tests of 316L stainless steel under different loading conditions

NASA Astrophysics Data System (ADS)

Jiang, Huifeng; Chen, Xuedong; Fan, Zhichao; Dong, Jie; Jiang, Heng; Lu, Shouxiang

2009-08-01

Stress controlled fatigue-creep tests were carried out for 316L stainless steel under different loading conditions, i.e. different loading levels at the fixed temperature (loading condition 1, LC1) and different temperatures at the fixed loading level (loading condition 2, LC2). Cyclic deformation behaviors were investigated with respect to the evolutions of strain amplitude and mean strain. Abrupt mean strain jumps were found during cyclic deformation, which was in response to the dynamic strain aging effect. Moreover, as to LC1, when the minimum stress is negative at 550 °C, abrupt mean strain jumps occur at the early stage of cyclic deformation and there are many jumps during the whole process. While the minimum stress is positive, mean strain only jumps once at the end of deformation. Similar results were also found in LC2, when the loading level is fixed at -100 to 385 MPa, at higher temperatures (560, 575 °C), abrupt mean strain jumps occur at the early stage of cyclic deformation and there are many jumps during the whole process. While at lower temperature (540 °C), mean strain only jumps once at the end of deformation.

Neuropathogenic capacity of lentogenic, mesogenic, and velogenic Newcastle disease virus strains in day-old chickens

USDA-ARS?s Scientific Manuscript database

Strains of Newcastle disease virus (NDV) have different abilities to elicit neurological signs in infected birds. Although neuropathogenesis has been characterized in classical animal experiments, there is no specific “in vivo” method to study the intrinsic capacity of NDV strains to infect the bra...

Impaired Endothelial Repair Capacity of Early Endothelial Progenitor Cells in Hypertensive Patients With Primary Hyperaldosteronemia: Role of 5,6,7,8-Tetrahydrobiopterin Oxidation and Endothelial Nitric Oxide Synthase Uncoupling.

PubMed

Chen, Long; Ding, Mei-Lin; Wu, Fang; He, Wen; Li, Jin; Zhang, Xiao-Yu; Xie, Wen-Li; Duan, Sheng-Zhong; Xia, Wen-Hao; Tao, Jun

2016-02-01

Although hyperaldosteronemia exerts detrimental impacts on vascular endothelium in addition to elevating blood pressure, the effects and molecular mechanisms of hyperaldosteronemia on early endothelial progenitor cell (EPC)-mediated endothelial repair after arterial damage are yet to be determined. The aim of this study was to investigate the endothelial repair capacity of early EPCs from hypertensive patients with primary hyperaldosteronemia (PHA). In vivo endothelial repair capacity of early EPCs from PHAs (n=20), age- and blood pressure-matched essential hypertension patients (n=20), and age-matched healthy subjects (n=20) was evaluated by transplantation into a nude mouse carotid endothelial denudation model. Endothelial function was evaluated by flow-mediated dilation of brachial artery in human subjects. In vivo endothelial repair capacity of early EPCs and flow-mediated dilation were impaired both in PHAs and in essential hypertension patients when compared with age-matched healthy subjects; however, the early EPC in vivo endothelial repair capacity and flow-mediated dilation of PHAs were impaired more severely than essential hypertension patients. Oral spironolactone improved early EPC in vivo endothelial repair capacity and flow-mediated dilation of PHAs. Increased oxidative stress, oxidative 5,6,7,8-tetrahydrobiopterin degradation, endothelial nitric oxide synthase uncoupling and decreased nitric oxide production were found in early EPCs from PHAs. Nicotinamide adenine dinucleotide phosphate oxidase subunit p47(phox) knockdown or 5,6,7,8-tetrahydrobiopterin supplementation attenuated endothelial nitric oxide synthase uncoupling and enhanced in vivo endothelial repair capacity of early EPCs from PHAs. In conclusion, PHAs exhibited more impaired endothelial repair capacity of early EPCs than did essential hypertension patients independent of blood pressure, which was associated with mineralocorticoid receptor-dependent oxidative stress and subsequently 5

Prediction (early recognition) of emerging flu strain clusters

NASA Astrophysics Data System (ADS)

Li, X.; Phillips, J. C.

2017-08-01

Early detection of incipient dominant influenza strains is one of the key steps in the design and manufacture of an effective annual influenza vaccine. Here we report the most current results for pandemic H3N2 flu vaccine design. A 2006 model of dimensional reduction (compaction) of viral mutational complexity derives two-dimensional Cartesian mutational maps (2DMM) that exhibit an emergent dominant strain as a small and distinct cluster of as few as 10 strains. We show that recent extensions of this model can detect incipient strains one year or more in advance of their dominance in the human population. Our structural interpretation of our unexpectedly rich 2DMM involves sialic acid, and is based on nearly 6000 strains in a series of recent 3-year time windows. Vaccine effectiveness is predicted best by analyzing dominant mutational epitopes.

Printed strain sensors for early damage detection in engineering structures

NASA Astrophysics Data System (ADS)

Zymelka, Daniel; Yamashita, Takahiro; Takamatsu, Seiichi; Itoh, Toshihiro; Kobayashi, Takeshi

2018-05-01

In this paper, we demonstrate the analysis of strain measurements recorded using a screen-printed sensors array bonded to a metal plate and subjected to high strains. The analysis was intended to evaluate the capabilities of the printed strain sensors to detect abnormal strain distribution before actual defects (cracks) in the analyzed structures appear. The results demonstrate that the developed device can accurately localize the enhanced strains at the very early stage of crack formation. The promising performance and low fabrication cost confirm the potential suitability of the printed strain sensors for applications within the framework of structural health monitoring (SHM).

Streptococcus pyogenes strains in Sao Paulo, Brazil: molecular characterization as a basis for StreptInCor coverage capacity analysis.

PubMed

Freschi de Barros, Samar; De Amicis, Karine Marafigo; Alencar, Raquel; Smeesters, Pierre Robert; Trunkel, Ariel; Postól, Edilberto; Almeida Junior, João Nóbrega; Rossi, Flavia; Pignatari, Antonio Carlos Campos; Kalil, Jorge; Guilherme, Luiza

2015-08-05

Several human diseases are caused by Streptococcus pyogenes, ranging from common infections to autoimmunity. Characterization of the most prevalent strains worldwide is a useful tool for evaluating the coverage capacity of vaccines under development. In this study, a collection of S. pyogenes strains from Sao Paulo, Brazil, was analyzed to describe the diversity of strains and assess the vaccine coverage capacity of StreptInCor. Molecular epidemiology of S. pyogenes strains was performed by emm-genotyping the 229 isolates from different clinical sites, and PCR was used for superantigen profile analysis. The emm-pattern and tissue tropism for these M types were also predicted and compared based on the emm-cluster classification. The strains were fit into 12 different emm-clusters, revealing a diverse phylogenetic origin and, consequently, different mechanisms of infection and escape of the host immune system. Forty-eight emm-types were distinguished in 229 samples, and the 10 most frequently observed types accounted for 69 % of all isolates, indicating a diverse profile of circulating strains comparable to other countries under development. A similar proportion of E and A-C emm-patterns were observed, whereas pattern D was less frequent, indicating that the strains of this collection primarily had a tissue tropism for the throat. In silico analysis of the coverage capacity of StreptInCor, an M protein-conserved regionally based vaccine candidate developed by our group, had a range of 94.5 % to 59.7 %, with a mean of 71.0 % identity between the vaccine antigen and the predicted amino acid sequence of the emm-types included here. This is the first report of S. pyogenes strain characterization in Sao Paulo, one of the largest cities in the world; thus, the strain panel described here is a representative sample for vaccine coverage capacity analysis. Our results enabled evaluation of StreptInCor candidate vaccine coverage capacity against diverse M-types, indicating

Perceived Economic Strain and Psychological Well-Being: The Mediational Role of Parental Relations in Turkish Early Adolescents

ERIC Educational Resources Information Center

Uçanok, Zehra; Güre, Ays?en

2014-01-01

This study primarily aims to explore the association between perceived economic strain, parent-adolescent relational qualities and psychological well-being and to investigate the dyadic parental relationships during early adolescence. A total of 414 adolescents between the ages of 10 and 14 (M= 12.58, SD = 0.90) from three different socioeconomic…

Intrinsic aerobic capacity sets a divide for aging and longevity.

PubMed

Koch, Lauren Gerard; Kemi, Ole J; Qi, Nathan; Leng, Sean X; Bijma, Piter; Gilligan, Lori J; Wilkinson, John E; Wisløff, Helene; Høydal, Morten A; Rolim, Natale; Abadir, Peter M; van Grevenhof, Elizabeth M; Smith, Godfrey L; Burant, Charles F; Ellingsen, Oyvind; Britton, Steven L; Wisløff, Ulrik

2011-10-28

Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease. For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15, and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO(2max)), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28% to 45% shorter than high capacity rats (hazard ratio, 0.06; P<0.001). VO(2max), measured across adulthood was a reliable predictor of lifespan (P<0.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca(2+) handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (Vo(2)), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and are useful for deeper mechanistic exploration of aging.

Computational Thermomechanical Modelling of Early-Age Silicate Composites

NASA Astrophysics Data System (ADS)

Vala, J.; Št'astník, S.; Kozák, V.

2009-09-01

Strains and stresses in early-age silicate composites, widely used in civil engineering, especially in fresh concrete mixtures, in addition to those caused by exterior mechanical loads, are results of complicated non-deterministic physical and chemical processes. Their numerical prediction at the macro-scale level requires the non-trivial physical analysis based on the thermodynamic principles, making use of micro-structural information from both theoretical and experimental research. The paper introduces a computational model, based on a nonlinear system of macroscopic equations of evolution, supplied with certain effective material characteristics, coming from the micro-scale analysis, and sketches the algorithm for its numerical analysis.

Interactions between creep, fatigue and strain aging in two refractory alloys

NASA Technical Reports Server (NTRS)

Sheffler, K. D.

1972-01-01

The application of low-amplitude, high-frequency fatigue vibrations during creep testing of two strain-aging refractory alloys (molybdenum-base TZC and tantalum-base T-111) significantly reduced the creep strength of these materials. This strength reduction caused dramatic increases in both the first stage creep strain and the second stage creep rate. The magnitude of the creep rate acceleration varied directly with both frequency and A ratio (ratio of alternating to mean stress), and also varied with temperature, being greatest in the range where the strain-aging phenomenon was most prominent. It was concluded that the creep rate acceleration resulted from a negative strain rate sensitivity which is associated with the strain aging phenomenon in these materials. (A negative rate sensitivity causes flow stress to decrease with increasing strain rate, instead of increasing as in normal materials). By combining two analytical expressions which are normally used to describe creep and strain aging behavior, an expression was developed which correctly described the influence of temperature, frequency, and A ratio on the TZC creep rate acceleration.

Strain Aging Behavior in NiAl Microalloyed with Interstitial and Substitutional Solutes

NASA Technical Reports Server (NTRS)

Weaver, M. L.; Noebe R. D.; Kaufman, M. J.

1997-01-01

Dynamic strain aging has been investigated in polycrystalline NiAl alloys containing combined additions of interstitial and substitutional impurities. The results indicate that strain aging can be enhanced in polycrystalline alloys containing concentrations of silicon or iron in excess of 0.15 at.% in addition to conventional levels of carbon. This co-doping leads to very dramatic strain aging events, comparable to those typically observed in single crystals. This effect will be discussed with respect to conventional theories of strain aging.

Physical work capacity in older adults: implications for the aging worker.

PubMed

Kenny, Glen P; Yardley, Jane E; Martineau, Lucie; Jay, Ollie

2008-08-01

In many developed countries, the workforce is rapidly aging. Occupational demands however, have not decreased despite the fact that workers see a decline in physical work capacity with age. The purpose of this review is to examine the physiological adaptations to aging, the impact of aging on performance and the benefits of physical fitness in improving functional work capacity in aging individuals. An extensive search of the scientific literature was performed, acquiring published articles which examined the physiological changes associated with age-related decrements in the physical work capacity of healthy aging adults. The databases accessed included AARP Ageline, AccessScience, Annual Reviews, CISTI, Cochrane Library, Clinical Evidence, Digital Dissertations (Proquest), Embase, HealthSTAR, Medline, PubMed, Scopus, and PASCAL and included relevant information sites obtained on the world wide web. While a great deal of variation exists, an average decline of 20% in physical work capacity has been reported between the ages of 40 and 60 years, due to decreases in aerobic and musculoskeletal capacity. These declines can contribute to decreased work capacity, and consequential increases in work-related injuries and illness. However, differences in habitual physical activity will greatly influence the variability seen in individual physical work capacity and its components. Well-organized, management-supported, work-site health interventions encouraging physical activity during work hours could potentially decrease the incidence of age-related injury and illness. Age-associated functional declines and the accompanying risk of work-related injury can be prevented or at least delayed by the practice of regular physical activity. Older workers could optimally pursue their careers until retirement if they continuously maintain their physical training.

Antioxidant capacity of several Iranian, wild and cultivated strains of the button mushroom

PubMed Central

Tajalli, Faezeh; Malekzadeh, Khalil; Soltanian, Hadi; Janpoor, Javad; Rezaeian, Sharareh; Pourianfar, Hamid R.

2015-01-01

The white button mushroom, Agaricus bisporus, is the most commonly grown mushroom in Iran; however, there is a significant shortage of research on its antioxidant activity and other medicinal properties. The aim of this study was to evaluate antioxidant capacity of the methanolic extracts from four cultivated strains and four Internal Transcribed Spacer (ITS)-identified, Iranian wild isolates of A. bisporus. Evaluations were made for total phenols, flavonoids and anthocyanins, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Overall, results showed that all the wild isolates exhibited significantly lower DPPH-derived EC50, compared to the cultivated strains (p < 0.05). A relatively high relationship was observed between total phenols and flavonoids or anthocyanins (r2 > 0.60). However, these constituents could not statistically differentiate the group of wild samples from the cultivated ones, and there was low correlation with the DPPH-derived EC50s (r2 < 0.40). In conclusion, comparisons showed that wild isolate 4 and cultivated strains A15 and H1 had higher antioxidant capacity than the others (p < 0.05). This result identifies these mushrooms as good candidates for further investigation. PMID:26413059

Intrinsic aerobic capacity sets a divide for aging and longevity

PubMed Central

Koch, Lauren Gerard; Kemi, Ole J.; Qi, Nathan; Leng, Sean X.; Bijma, Piter; Gilligan, Lori J.; Wilkinson, John E.; Wisløff, Helene; Høydal, Morten A.; Rolim, Natale; Abadir, Peter M.; Van Grevenhof, Ilse; Smith, Godfrey L.; Burant, Charles F.; Ellingsen, Øyvind; Britton, Steven L.; Wisløff, Ulrik

2011-01-01

Rationale Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Objectives Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Methods and Results Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15 and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO2max), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28-45% shorter than high capacity rats (hazard ratio, 0.06; P<.001). VO2max, measured across adulthood was a reliable predictor of lifespan (P<.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca2+ handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (VO2), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. Conclusions These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and useful for deeper mechanistic exploration. PMID:21921265

Cd-Resistant Strains of B. cereus S5 with Endurance Capacity and Their Capacities for Cadmium Removal from Cadmium-Polluted Water

PubMed Central

Wu, Huiqing; Wu, Qingping; Wu, Guojie; Gu, Qihui; Wei, Linting

2016-01-01

The goal of this study was to identify Cd-resistant bacterial strains with endurance capacity and to evaluate their ability to remove cadmium ions from cadmium-polluted water. The Bacillus cereusS5 strain identified in this study had the closest genetic relationship with B. cereus sp. Cp1 and performed well in the removal of Cd2+ions from solution. The results showed that both the live and dead biomasses of the Cd2+-tolerant B. cereus S5 strain could absorb Cd2+ ions in solution but that the live biomass of the B. cereus S5 strain outperformed the dead biomass at lower Cd2+concentrations. An analysis of the cadmium tolerance genes of B. cereus S5 identified ATPase genes that were associated with cadmium tolerance and involved in the ATP pumping mechanism. The FTIR spectra revealed the presence of amino, carboxyl and hydroxyl groups on the pristine biomass and indicated that the cadmium ion removal ability was related to the structure of the strain. The maximum absorption capacity of the B. cereus S5 strain in viable spore biomass was 70.16 mg/g (dry weight) based on a pseudo-second-order kinetic model fit to the experimental data. The Langmuir and Langmuir-Freundlich isotherm adsorption models fit the cadmium ion adsorption data well, and the kinetic curves indicated that the adsorption rate was second-order. For Cd2+ concentrations (mg/L) of 1–109 mg/L, good removal efficiency (>80%) was achieved using approximately 3.48–10.3 g/L of active spore biomass of the B. cereus S5 strain. A cadmium-tolerant bacteria-activated carbon-immobilized column could be used for a longer duration and exhibited greater treatment efficacy than the control column in the treatment of cadmium-polluted water. In addition, a toxicity assessment using mice demonstrated that the biomass of the B. cereus S5 strain and its fermentation products were non-toxic. Thus, the isolated B. cereus S5 strain can be considered an alternative biological adsorbent for use in emergency responses to

Early Assessment of Right Ventricular Function in Systemic Lupus Erythematosus Patients using Strain and Strain Rate Imaging.

PubMed

Luo, Runlan; Cui, Hongyan; Huang, Dongmei; Sun, Lihua; Song, Shengda; Sun, Mengyao; Li, Guangsen

2018-06-11

Right ventricular function is a crucial factor of the prognosis of systemic lupus erythematosus (SLE). To evaluate the right ventricular function in SLE patients with different degrees of pulmonary hypertension (PH) by strain and strain rate imaging. A total of 102 SLE patients and 30 healthy volunteers were studied between October 2015 and May 2016. Patients were divided into three groups according to pulmonary artery systolic pressure (PASP) estimated by echocardiography: group control (A); PASP ≤ 30 mmHg (group B, n = 37); PASP 30-50 mmHg (mild PH; group C, n = 34); and PASP ≥ 50 mmHg (moderate-to-severe PH; group D, n = 31). Longitudinal peak systolic strain (ε) and strain rate (SR), including systolic strain rate (SRs), early diastolic strain rate (SRe) and late diastolic strain rate (SRa) were measured in the basal, middle and apical segments of the right ventricular free wall in participants by two-dimensional speckle tracking echocardiography (2D-STE) from the apical four-chamber view. A p < 0.05 was set for statistical significance. The parameters of ε, SRs, SRe, and SRa were significantly decreased in groups C and D compared with groups A and B. The ε of each segments was significantly lower in group D than in group C, while there were no differences in SRs, SRe and SRa between groups C and D. Strain and strain rate imaging could early detect the right ventricular dysfunction in SLE patients with PH, and provide important value for clinical therapy and prognosis of these patients. (Arq Bras Cardiol. 2018; [online].ahead print, PP.0-0).

An age-structured extension to the vectorial capacity model.

PubMed

Novoseltsev, Vasiliy N; Michalski, Anatoli I; Novoseltseva, Janna A; Yashin, Anatoliy I; Carey, James R; Ellis, Alicia M

2012-01-01

Vectorial capacity and the basic reproductive number (R(0)) have been instrumental in structuring thinking about vector-borne pathogen transmission and how best to prevent the diseases they cause. One of the more important simplifying assumptions of these models is age-independent vector mortality. A growing body of evidence indicates that insect vectors exhibit age-dependent mortality, which can have strong and varied affects on pathogen transmission dynamics and strategies for disease prevention. Based on survival analysis we derived new equations for vectorial capacity and R(0) that are valid for any pattern of age-dependent (or age-independent) vector mortality and explore the behavior of the models across various mortality patterns. The framework we present (1) lays the groundwork for an extension and refinement of the vectorial capacity paradigm by introducing an age-structured extension to the model, (2) encourages further research on the actuarial dynamics of vectors in particular and the relationship of vector mortality to pathogen transmission in general, and (3) provides a detailed quantitative basis for understanding the relative impact of reductions in vector longevity compared to other vector-borne disease prevention strategies. Accounting for age-dependent vector mortality in estimates of vectorial capacity and R(0) was most important when (1) vector densities are relatively low and the pattern of mortality can determine whether pathogen transmission will persist; i.e., determines whether R(0) is above or below 1, (2) vector population growth rate is relatively low and there are complex interactions between birth and death that differ fundamentally from birth-death relationships with age-independent mortality, and (3) the vector exhibits complex patterns of age-dependent mortality and R(0) ∼ 1. A limiting factor in the construction and evaluation of new age-dependent mortality models is the paucity of data characterizing vector mortality patterns

Immune response of Staphylococcus aureus strains in a mouse mastitis model is linked to adaptive capacity and genotypic profiles.

PubMed

Pereyra, Elizabet A L; Sacco, Sofía C; Duré, Andrea; Baravalle, Celina; Renna, María S; Andreotti, Carolina S; Monecke, Stefan; Calvinho, Luis F; Dallard, Bibiana E

2017-05-01

Staphylococcus aureus is one of the most frequently isolated major pathogens from intramammary infections (IMI) worldwide. The mechanisms by which S. aureus IMI are established and maintained in dairy cows involve both bacterial escape strategies and modulation of the host immune response. Moreover, it was shown that different S. aureus strains have varying effects on the immune response. The aim of this study was to investigate the immune response in a mouse mastitis model of two S. aureus strains isolated from bovine IMI with different clinical manifestation (persistent-P or non-persistent-NP), phenotypic and genotypic profile. Both strains were capable of establishing an IMI after 264h post inoculation (pi). Strain A (NP) showed a more aggressive behaviour than strain B (P) at early stages of IMI, while strain B multiplied initially at a lower rate but increased its replication capacity from 120h pi to the end of the study (264h pi). Strain A triggered a stronger initial inflammatory response compared with strain B inducing higher gene and protein expression of TLR2, NF-κB activation and higher gene expression of IL-1α at initial stage of IMI (6-12h pi) but inducing extensive mammary tissue damage. Immune cells response was different for each S. aureus strain throughout the course of infection, showing mammary glands inoculated with strain A greater initial immune cells stimulation compared with strain B and then a second immune cells stimulation (from 120 to 264h pi) represented by monocytes-macrophages, T and B lymphocytes, mainly stimulated by strain B, consistent with inflammatory process becoming chronic. Strain-specific pathogenicity observed underscores the importance of pathogen factors in the progression of the infectious process. These results contribute to increase the available information on host-pathogen interaction and point out for the need of further research to expand the knowledge about these interactions for developing new strategies to

Development of early age shrinkage stresses in reinforced concrete bridge decks

NASA Astrophysics Data System (ADS)

William, Gergis W.; Shoukry, Samir N.; Riad, Mourad Y.

2008-12-01

This paper describes the instrumentation and data analysis of a reinforced concrete bridge deck constructed on 3-span continuous steel girders in Evansville, West Virginia. An instrumentation system consisting of 232 sensors is developed and implemented specifically to measure strains and temperature in concrete deck, strains in longitudinal and transverse rebars, the overall contraction and expansion of concrete deck, and crack openings. Data from all sensors are automatically collected every 30 minutes starting at the time of placing the concrete deck. Measured strain and temperature time-histories were used to calculate the stresses, which were processed to attenuate the thermal effects due to daily temperature changes and isolate the drying shrinkage component. The results indicated that most of concrete shrinkage occurs during the first three days. Under the constraining effects from stay-in-place forms and reinforcement, early age shrinkage leads to elevated longitudinal stress, which is the main factor responsible for crack initiation.

Early-age hydration and volume change of calcium sulfoaluminate cement-based binders

NASA Astrophysics Data System (ADS)

Chaunsali, Piyush

-based binders without taking into account the viscoelastic effects. For the first time, model based on poromechanics was used to calculate the macroscopic tensile stress that develops in CSA cement-based binders due to crystallization of ettringite. The models enabled a reasonable prediction of tensile stress due to crystallization of ettringite including the failure of an OPC-CSA binder which had high CSA cement content. Elastic strain based on crystallization stress was calculated and compared with the observed strain. A mismatch between observed and calculated elastic strain indicated the presence of early-age creep. Lastly, the application of CSA cement in concretes is discussed to link the paste and concrete behavior.

Type I Diabetic Akita Mouse Model is Characterized by Abnormal Cardiac Deformation During Early Stages of Diabetic Cardiomyopathy with Speckle-Tracking Based Strain Imaging.

PubMed

Zhou, Yingchao; Xiao, Hong; Wu, Jianfei; Zha, Lingfeng; Zhou, Mengchen; Li, Qianqian; Wang, Mengru; Shi, Shumei; Li, Yanze; Lyu, Liangkun; Wang, Qing; Tu, Xin; Lu, Qiulun

2018-01-01

Diabetes mellitus (DM) has been demonstrated to have a strong association with heart failure. Conventional echocardiographic analysis cannot sensitively monitor cardiac dysfunction in type I diabetic Akita hearts, but the phenotype of heart failure is observed in molecular levels during the early stages. Male Akita (Ins2WT/C96Y) mice were monitored with echocardiographic imaging at various ages, and then with conventional echocardiographic analysis and speckle-tracking based strain analyses. With speckle-tracking based strain analyses, diabetic Akita mice showed changes in average global radial strain at the age of 12 weeks, as well as decreased longitudinal strain. These changes occurred in the early stage and remained throughout the progression of diabetic cardiomyopathy in Akita mice. Speckle-tracking showed that the detailed and precise changes of cardiac deformation in the progression of diabetic cardiomyopathy in the genetic type I diabetic Akita mice were uncoupled. We monitored early-stage changes in the heart of diabetic Akita mice. We utilize this technique to elucidate the underlying mechanism for heart failure in Akita genetic type I diabetic mice. It will further advance the assessment of cardiac abnormalities, as well as the discovery of new drug treatments using Akita genetic type I diabetic mice. © 2018 The Author(s). Published by S. Karger AG, Basel.

Exercise training, vascular function, and functional capacity in middle-aged subjects.

PubMed

Maiorana, A; O'Driscoll, G; Dembo, L; Goodman, C; Taylor, R; Green, D

2001-12-01

The aim of this study was to investigate the effect of 8 wk of exercise training on functional capacity, muscular strength, body composition, and vascular function in sedentary but healthy subjects by using a randomized, crossover protocol. After familiarization sessions, 19 subjects aged 47 +/- 2 yr (mean +/- SE) undertook a randomized, crossover design study of the effect of 8 wk of supervised circuit training consisting of combined aerobic and resistance exercise. Peak oxygen uptake (.VO(2peak)), sum of 7 maximal voluntary contractions and the sum of 8 skinfolds and 5 segment girths were determined at entry, crossover, and 16 wk. Endothelium-dependent and -independent vascular function were determined by forearm strain-gauge plethysmography and intrabrachial infusions of acetylcholine (ACh) and sodium nitroprusside (SNP) in 16 subjects. Training did not alter ACh or SNP responses. .VO(2peak), (28.6 +/- 1.1 to 32.6 +/- 1.3 mL.kg(-1).min(-1), P < 0.001), exercise test duration (17.4 +/- 1.1 to 22.1 +/- 1.2 min, P < 0.001), and muscular strength (465 +/- 27 to 535 +/- 27 kg, P < 0.001) significantly increased after the exercise program, whereas skinfolds decreased (144 +/- 10 vs 134 +/- 9 mm, P < 0.001). These results suggest that moderate intensity circuit training designed to minimize the involvement of the arms improves functional capacity, body composition, and strength in healthy, middle-aged subjects without significantly influencing upper limb vascular function. This finding contrasts with previous studies in subjects with type 2 diabetes and heart failure that employed an identical training program.

Observations of Static Strain-Aging in Polycrystalline NiAl

NASA Technical Reports Server (NTRS)

Weaver, M. L.; Noebe, R. D.; Lewandowski, J. J.; Oliver, B. F.; Kaufman, M. J.

1996-01-01

Static strain-aging has been investigated in eight polycrystalline NiAl alloys. After annealing at 1100 K for 7200 s followed by furnace cooling, high-purity, nitrogen-doped, and titanium-doped alloys exhibited continuous yielding, while conventional-purity and carbon-doped alloys exhibited distinct upper yield points and Luders strains. Either water quenching from 1100 K or prestraining via hydrostatic pressurization suppressed the yield points in the latter alloys, but they could be reintroduced by further annealing treatments. Yield points could be reintroduced more rapidly if the specimens were prestrained uniaxially rather than hydrostatically, owing to the arrangement of dislocations into cell structures during uniaxial deformation. Chemical analysis suggests that the species responsible for strain-aging is interstitial carbon.

Normal references of right ventricular strain values by two-dimensional strain echocardiography according to the age and gender.

PubMed

Park, Jae-Hyeong; Choi, Jin-Oh; Park, Seung Woo; Cho, Goo-Yeong; Oh, Jin Kyung; Lee, Jae-Hwan; Seong, In-Whan

2018-02-01

Right ventricular (RV) strain values by 2-dimensional strain echocardiography (STE) can be used as objective markers of RV systolic function. However, there is little data about normal reference RV strain values according to age and gender. We measured normal RV strain values by STE. RV strain values were analyzed from the digitally stored echocardiographic images from NORMAL (Normal echOcardiogRaphic diMensions and functions in KoreAn popuLation) study for the measurement of normal echocardiographic values performed in 23 Korean university hospitals. We enrolled total 1003 healthy persons in the NORMAL study. Of them, we analyzed 2-dimensional RV strain values in 493 subjects (261 females, mean 47 ± 15 years old) only with echocardiographic images by GE machines. Their LV systolic and diastolic functions were normal. RV fractional area change was 48 ± 6% and tricuspid annular plane systolic excursion was 23 ± 3 mm. Total RV global longitudinal peak systolic strain (RVGLS total ) was -21.5 ± 3.2%. Females had higher absolute RVGLS total (-22.3 ± 3.3 vs -20.7 ± 2.9%, p < 0.001) than males. Younger (<50 years old) females had higher absolute RVGLS total (-22.9 ± 3.2 vs -20.5 ± 2.8%, p < 0.001) than age matched males. RVGLS total in females gradually increased according to age (p for trend = 0.002) and becomes almost similar in age ≥50 years. However, this trend was not seen in males (p for trend = 0.287), and younger males had similar RVGLS total value to that of older males (age ≥50 years, -20.5 ± 2.8 vs -20.9 ± 3.1%, p = 0.224). We calculated normal RVGLS values in normal population. Females have higher absolute strain values than males, especially in younger age groups (<50 years old).

Strain-age cracking in Rene 41 alloy

NASA Technical Reports Server (NTRS)

Prager, M.; Thompson, E. G.

1969-01-01

Weldability test determines the effects of material and process variables on the occurrence of strain-age cracking, and demonstrates effective and practical means for its reduction. Studies consist of tensile, impact, and stress-rupture tests.

Evaluation of Trastuzumab-induced early cardiac dysfunction using two-dimensional Strain Echocardiography.

PubMed

Emren, Sadik Volkan; Tuluce, Selcen Yakar; Levent, Fatih; Tuluce, Kamil; Kalkan, Toygar; Yildiz, Yasar; Alacacioğlu, Ahmet; Kucukzeybek, Yüksel; Akyol, Murat; Salman, Tarık

2015-12-01

Trastuzumab, a chemotherapeutic agent used in the treatment of breast cancer. has been shown to induce subclinical left ventricular (LV) dysfunction during a three to six month period as evidenced by strain echocardiographic examination without any change occurring in the ejection fraction of LV. The present study evaluated the presence of subclinical LV dysfunction using strain echocardiography 1 day and 7 days after the initiation of trastuzumab therapy. The patients with breast cancer receiving adjuvant trastuzumab therapy underwent 2-dimensional, tissue Doppler, and strain echocardiographic examination at baseline and 1 day and 7 days after therapy. LV global longitudinal strain (GLS), global circumferential strain (GCS) values, and other echocardiographic parameters were calculated. A total of 40 females, mean age 50+/-10 years, were evaluated. Of these patients, 97% received anthracycline and 73% received radiotherapy before the initiation of trastuzumab therapy. No change was observed in any of the echocardiographic parameters 1 day after the initiation of trastuzumab therapy (p>0.05). The LV ejection fraction, tissue Doppler parameters, and GCS values did not show any changes 7 days after the initiation of therapy, whereas significant decreases were observed in GLS value (19.2+/-4.0% vs. 17.2+/-3.4, p=0.001) and systolic annular velocity of the lateral LV wall (S' velocity) (10.5+/-3.2 vs. 8.6+/-2.2, p=0.002). Trastuzumab therapy is associated with subclinical LV dysfunction as early as 7 days after initiation of the therapy as evidenced by the decreases in GLS value of LV and systolic annular velocity of the lateral LV wall.

High Aerobic Capacity Mitigates Changes in the Plasma Metabolomic Profile Associated with Aging.

PubMed

Falegan, Oluyemi S; Vogel, Hans J; Hittel, Dustin S; Koch, Lauren G; Britton, Steven L; Hepple, Russ T; Shearer, Jane

2017-02-03

Advancing age is associated with declines in maximal oxygen consumption. Declines in aerobic capacity not only contribute to the aging process but also are an independent risk factor for morbidity, cardiovascular disease, and all-cause mortality. Although statistically convincing, the relationships between aerobic capacity, aging, and disease risk remain largely unresolved. To this end, we employed sensitive, system-based metabolomics approach to determine whether enhanced aerobic capacity could mitigate some of the changes seen in the plasma metabolomic profile associated with aging. Metabolomic profiles of plasma samples obtained from young (13 month) and old (26 month) rats bred for low (LCR) or high (HCR) running capacity using proton nuclear magnetic resonance spectroscopy ( 1 H NMR) were examined. Results demonstrated strong profile separation in old and low aerobic capacity rats, whereas young and high aerobic capacity rat models were less predictive. Significantly differential metabolites between the groups include taurine, acetone, valine, and trimethylamine-N-oxide among other metabolites, specifically citrate, succinate, isovalerate, and proline, were differentially increased in older HCR animals compared with their younger counterparts. When interactions between age and aerobic capacity were examined, results demonstrated that enhanced aerobic capacity could mitigate some but not all age-associated alterations in the metabolomic profile.

An Age-Structured Extension to the Vectorial Capacity Model

PubMed Central

Novoseltsev, Vasiliy N.; Michalski, Anatoli I.; Novoseltseva, Janna A.; Yashin, Anatoliy I.; Carey, James R.; Ellis, Alicia M.

2012-01-01

Background Vectorial capacity and the basic reproductive number (R0) have been instrumental in structuring thinking about vector-borne pathogen transmission and how best to prevent the diseases they cause. One of the more important simplifying assumptions of these models is age-independent vector mortality. A growing body of evidence indicates that insect vectors exhibit age-dependent mortality, which can have strong and varied affects on pathogen transmission dynamics and strategies for disease prevention. Methodology/Principal Findings Based on survival analysis we derived new equations for vectorial capacity and R0 that are valid for any pattern of age-dependent (or age–independent) vector mortality and explore the behavior of the models across various mortality patterns. The framework we present (1) lays the groundwork for an extension and refinement of the vectorial capacity paradigm by introducing an age-structured extension to the model, (2) encourages further research on the actuarial dynamics of vectors in particular and the relationship of vector mortality to pathogen transmission in general, and (3) provides a detailed quantitative basis for understanding the relative impact of reductions in vector longevity compared to other vector-borne disease prevention strategies. Conclusions/Significance Accounting for age-dependent vector mortality in estimates of vectorial capacity and R0 was most important when (1) vector densities are relatively low and the pattern of mortality can determine whether pathogen transmission will persist; i.e., determines whether R0 is above or below 1, (2) vector population growth rate is relatively low and there are complex interactions between birth and death that differ fundamentally from birth-death relationships with age-independent mortality, and (3) the vector exhibits complex patterns of age-dependent mortality and R0∼1. A limiting factor in the construction and evaluation of new age-dependent mortality models is the

Digestive capacities, inbreeding and growth capacities in juvenile Arctic charr Salvelinus alpinus.

PubMed

Ditlecadet, D; Blier, P U; Le François, N R; Dufresne, F

2009-12-01

Genetic variation in growth performance was estimated in 26 families from two commercial strains of Arctic charr Salvelinus alpinus. Physiological determinants of growth and metabolic capacities were also assessed through enzymatic assays. A relatedness coefficient was attributed to each family using parental genotypes at seven microsatellite loci. After 15 months of growth, faster growing families had significantly lower relatedness coefficients than slower growing families, suggesting their value as indicators of growth potential. Individual fish that exhibited higher trypsin activity also displayed higher growth rate, suggesting that superior protein digestion capacities can be highly advantageous at early stages. Capacities to use amino acids as expressed by glutamate dehydrogenase (GDH) activities were lower in the liver of fast-growing fish (13-20%), whereas white muscle of fast-growing fish showed higher activities than that of slow-growing fish for amino acid metabolism and aerobic capacity [22-32% increase for citrate synthase (CS), aspartate aminotransferase (AAT) and GDH]. The generally higher glycolytic capacities (PK and LDH) in white muscle of fast-growing fish indicated higher burst swimming capacities and hence better access to food.

Assessment of Capacity in an Aging Society

PubMed Central

Moye, Jennifer; Marson, Daniel C.; Edelstein, Barry

2014-01-01

Over the past 40 years, the assessment and scientific study of capacity in older adults has emerged as a distinct field of clinical and research activity for psychologists. This new field reflects the convergence of several trends: the aging of American society, the growing incidence and prevalence of dementia, and the patient rights, deinstitutionalization, and disability rights movements. Because of these forces, capacity issues now permeate the fabric of everyday life, whether in the form of guardianship petitions, questions of capacity to consent to treatment, the ability to make a new will, or participation in human research. In seeking to resolve these issues, families, clinicians, and legal professionals increasingly turn to psychologists to assess a capacity and to provide empirically supported judgments that properly balance autonomy and protection for the individual. Psychologists have taken a leading role in the development of functional assessment instruments that measure important aspects of the capacity construct. In addition, psychology has been a major contributor to the scientific study of capacity. In collaboration with colleagues from medicine and law, psychologists have articulated crucial theoretical frameworks that integrate legal, clinical, and ethical dimensions of the capacity problem. This article focuses on the evolution of theory, law, science, and practice in the evaluation of capacity in older adults and its recent culmination in a series of interdisciplinary handbooks sponsored by the American Psychological Association and the American Bar Association. PMID:23586491

Assessment of capacity in an aging society.

PubMed

Moye, Jennifer; Marson, Daniel C; Edelstein, Barry

2013-04-01

Over the past 40 years, the assessment and scientific study of capacity in older adults has emerged as a distinct field of clinical and research activity for psychologists. This new field reflects the convergence of several trends: the aging of American society, the growing incidence and prevalence of dementia, and the patient rights, deinstitutionalization, and disability rights movements. Because of these forces, capacity issues now permeate the fabric of everyday life, whether in the form of guardianship petitions, questions of capacity to consent to treatment, the ability to make a new will, or participation in human research. In seeking to resolve these issues, families, clinicians, and legal professionals increasingly turn to psychologists to assess a capacity and to provide empirically supported judgments that properly balance autonomy and protection for the individual. Psychologists have taken a leading role in the development of functional assessment instruments that measure important aspects of the capacity construct. In addition, psychology has been a major contributor to the scientific study of capacity. In collaboration with colleagues from medicine and law, psychologists have articulated crucial theoretical frameworks that integrate legal, clinical, and ethical dimensions of the capacity problem. This article focuses on the evolution of theory, law, science, and practice in the evaluation of capacity in older adults and its recent culmination in a series of interdisciplinary handbooks sponsored by the American Psychological Association and the American Bar Association.

Equilibrium oxygen storage capacity of ultrathin CeO 2-δ depends non-monotonically on large biaxial strain

DOE PAGES

Gopal, Chirranjeevi Balaji; Garcia-Melchor, Max; Lee, Sang Chul; ...

2017-05-18

Elastic strain is being increasingly employed to enhance the catalytic properties of mixed ion–electron conducting oxides. However, its effect on oxygen storage capacity is not well established. Here, we fabricate ultrathin, coherently strained films of CeO 2-δ between 5.6% biaxial compression and 2.1% tension. In situ ambient pressure X-ray photoelectron spectroscopy reveals up to a fourfold enhancement in equilibrium oxygen storage capacity under both compression and tension. This non-monotonic variation with strain departs from the conventional wisdom based on a chemical expansion dominated behaviour. Through depth profiling, film thickness variations and a coupled photoemission–thermodynamic analysis of space-charge effects, we showmore » that the enhanced reducibility is not dominated by interfacial effects. On the basis of ab initio calculations of oxygen vacancy formation incorporating defect interactions and vibrational contributions, we suggest that the non-monotonicity arises from the tetragonal distortion under large biaxial strain. Finally, these results may guide the rational engineering of multilayer and core–shell oxide nanomaterials.« less

In-planta Sporulation Capacity Enhances Infectivity and Rhizospheric Competitiveness of Frankia Strains.

PubMed

Cotin-Galvan, Laetitia; Pozzi, Adrien C; Schwob, Guillaume; Fournier, Pascale; Fernandez, Maria P; Herrera-Belaroussi, Aude

2016-01-01

Frankia Sp+ strains maintain their ability to sporulate in symbiosis with actinorhizal plants, producing abundant sporangia inside host plant cells, in contrast to Sp- strains, which are unable to perform in-planta sporulation. We herein examined the role of in-planta sporulation in Frankia infectivity and competitiveness for root infection. Fifteen strains belonging to different Sp+ and Sp- phylogenetic lineages were inoculated on seedlings of Alnus glutinosa (Ag) and A. incana (Ai). Strain competitiveness was investigated by performing Sp-/Sp+ co-inoculations. Plant inoculations were standardized using crushed nodules obtained under laboratory-controlled conditions (same plant species, age, and environmental factors). Specific oligonucleotide primers were developed to identify Frankia Sp+ and/or Sp- strains in the resulting nodules. Single inoculation experiments showed that (i) infectivity by Sp+ strains was significantly greater than that by Sp- strains, (ii) genetically divergent Sp+ strains exhibited different infective abilities, and (iii) Sp+ and Sp- strains showed different host preferences according to the origin (host species) of the inocula. Co-inoculations of Sp+ and Sp- strains revealed the greater competitiveness of Sp+ strains (98.3 to 100% of Sp+ nodules, with up to 15.6% nodules containing both Sp+ and Sp- strains). The results of the present study highlight differences in Sp+/Sp- strain ecological behaviors and provide new insights to strengthen the obligate symbiont hypothesis for Sp+ strains.

In-planta Sporulation Capacity Enhances Infectivity and Rhizospheric Competitiveness of Frankia Strains

PubMed Central

Cotin-Galvan, Laetitia; Pozzi, Adrien C.; Schwob, Guillaume; Fournier, Pascale; Fernandez, Maria P.; Herrera-Belaroussi, Aude

2016-01-01

Frankia Sp+ strains maintain their ability to sporulate in symbiosis with actinorhizal plants, producing abundant sporangia inside host plant cells, in contrast to Sp− strains, which are unable to perform in-planta sporulation. We herein examined the role of in-planta sporulation in Frankia infectivity and competitiveness for root infection. Fifteen strains belonging to different Sp+ and Sp− phylogenetic lineages were inoculated on seedlings of Alnus glutinosa (Ag) and A. incana (Ai). Strain competitiveness was investigated by performing Sp−/Sp+ co-inoculations. Plant inoculations were standardized using crushed nodules obtained under laboratory-controlled conditions (same plant species, age, and environmental factors). Specific oligonucleotide primers were developed to identify Frankia Sp+ and/or Sp− strains in the resulting nodules. Single inoculation experiments showed that (i) infectivity by Sp+ strains was significantly greater than that by Sp− strains, (ii) genetically divergent Sp+ strains exhibited different infective abilities, and (iii) Sp+ and Sp− strains showed different host preferences according to the origin (host species) of the inocula. Co-inoculations of Sp+ and Sp− strains revealed the greater competitiveness of Sp+ strains (98.3 to 100% of Sp+ nodules, with up to 15.6% nodules containing both Sp+ and Sp− strains). The results of the present study highlight differences in Sp+/Sp− strain ecological behaviors and provide new insights to strengthen the obligate symbiont hypothesis for Sp+ strains. PMID:26726131

Morphological and physiological changes exhibited by a Cd-resistant Dictyosphaerium chlorelloides strain and its cadmium removal capacity.

PubMed

Bartolomé, M C; Cortés, A A; Sánchez-Fortún, A; Garnica-Romo, M G; Sánchez-Carrillo, S; Sánchez-Fortún, Sebastián

2016-12-01

Changes induced on freshwater microalga Dictyosphaerium chlorelloides (Dc(wt)) acclimated in the laboratory until their survival in culture media enriched with cadmium 100 µM have been studied. Cadmium removal by living cells of this Cd-resistant (Dc(CdR100)) strain was tested in cultures exposed to 100 µM Cd during 30 days. Cell dimensions were measured under light microscopy, and cell growth was studied. Photosynthetic yield (ΦPSII) was analyzed and the photosynthetic oxygen development and respiration response was obtained. Results show that Dc(CdR100) strain exhibited significant cell morphology changes in comparison to Dc(wt) cells, which affected both surface area and cell biovolume. Malthusian fitness analysis showed that Dc(CdR100) strain living in Cd-enriched culture had developed a lower capacity of nearly 50% growth, and its photosynthetic oxygen development and respiration response were significantly reduced in both light and dark photosynthetic phases. Dc(CdR100) strain showed a very high capacity to remove cadmium from the aquatic environment (over 90%), although most of the removed heavy metal (≈70%) is adhered to the cell wall. These specific characteristics of Dc(CdR100) cells suggest the possibility of using this strain in conjunction with Dc(wt) strain as bioelements into a dual-head biosensor, and in bioremediation processes on freshwater polluted with Cd.

[The use of biological age on mental work capacity model in accelerated aging assessment of professional lorry-drivers].

PubMed

Bashkireva, A S

2012-01-01

The studies of biological age, aging rate, mental work capacity in professional drivers were conducted. The examination revealed peculiarities of system organization of functions determining the mental work capacity levels. Dynamics of the aging process of professional driver's organism in relation with calendar age and driving experience were shown using the biological age model. The results point at the premature decrease of the mental work capacity in professional drivers. It was proved, that premature age-related changes of physiologic and psychophysiologic indices in drivers are just "risk indicators", while long driving experience is a real risk factor, accelerating the aging process. The "risk group" with manifestations of accelerating aging was observed in 40-49-year old drivers with 15-19 years of professional experience. The expediency of using the following methods for the age rate estimation according to biologic age indices and necessity of prophylactic measures for premature and accelerated aging prevention among working population was demonstrated.

Dietary restriction improves repopulation but impairs lymphoid differentiation capacity of hematopoietic stem cells in early aging

PubMed Central

Tang, Duozhuang; Tao, Si; Chen, Zhiyang; Koliesnik, Ievgen Oleksandrovich; Calmes, Philip Gerald; Hoerr, Verena; Han, Bing; Gebert, Nadja; Zörnig, Martin; Löffler, Bettina

2016-01-01

Dietary restriction (DR) improves health, delays tissue aging, and elongates survival in flies and worms. However, studies on laboratory mice and nonhuman primates revealed ambiguous effects of DR on lifespan despite improvements in health parameters. In this study, we analyzed consequences of adult-onset DR (24 h to 1 yr) on hematopoietic stem cell (HSC) function. DR ameliorated HSC aging phenotypes, such as the increase in number of HSCs and the skewing toward myeloid-biased HSCs during aging. Furthermore, DR increased HSC quiescence and improved the maintenance of the repopulation capacity of HSCs during aging. In contrast to these beneficial effects, DR strongly impaired HSC differentiation into lymphoid lineages and particularly inhibited the proliferation of lymphoid progenitors, resulting in decreased production of peripheral B lymphocytes and impaired immune function. The study shows that DR-dependent suppression of growth factors and interleukins mediates these divergent effects caused by DR. Supplementation of insulin-like growth factor 1 partially reverted the DR-induced quiescence of HSCs, whereas IL-6/IL-7 substitutions rescued the impairment of B lymphopoiesis exposed to DR. Together, these findings delineate positive and negative effects of long-term DR on HSC functionality involving distinct stress and growth signaling pathways. PMID:26951333

Effects of Applied Strain on Rates of Ageing: Project Overview

NASA Technical Reports Server (NTRS)

Campion, R. P.

1997-01-01

One of the stated intents of this project has been to make some assessment of effects of strain on rates of ageing of project thermoplastics exposed to project fluids. To this end, certain straining jigs which apply in various modes - tensile, four-point bending and crack growth using compact tension samples - were designed and made for holding samples during fluid exposures. During testing, features of the thermoplastics have been observed which have tended to confuse apparent strain effects on the polymers' aged performance, but recent assessments of the topic and its data have led to considerable progress being made in identifying test procedures necessary for strain and related effects on chemical deterioration to manifest themselves. It is the intent of this report to provide a summary of what has been determined on strain and related effects thus far, and provide recommendations for clarifying them in Phase 2 by means of further test procedures which will increase and focus the severity of the conditions applying. The choice of flexible pipe rather than umbilicals service for assessing service strain conditions reflects the major interest of project members. However, Tefzel data are still provided.

Children with severe early childhood caries: streptococci genetic strains within carious and white spot lesions.

PubMed

Gilbert, Kenneth; Joseph, Raphael; Vo, Alex; Patel, Trusha; Chaudhry, Samiya; Nguyen, Uyen; Trevor, Amy; Robinson, Erica; Campbell, Margaret; McLennan, John; Houran, Farielle; Wong, Tristan; Flann, Kendra; Wages, Melissa; Palmer, Elizabeth A; Peterson, John; Engle, John; Maier, Tom; Machida, Curtis A

2014-01-01

Mutans streptococci (MS) are one of the major microbiological determinants of dental caries. The objectives of this study are to identify distinct MS and non-MS streptococci strains that are located at carious sites and non-carious enamel surfaces in children with severe early childhood caries (S-ECC), and assess if cariogenic MS and non-cariogenic streptococci might independently exist as primary bacterial strains on distinct sites within the dentition of individual children. Dental plaque from children (N=20; aged 3-6) with S-ECC was collected from carious lesions (CLs), white spot lesions (WSLs) and non-carious enamel surfaces. Streptococcal isolates (N=10-20) from each site were subjected to polymerase chain reaction (PCR) to identify MS, and arbitrarily primed-PCR for assignment of genetic strains. Primary strains were identified as ≥50% of the total isolates surveyed at any site. In several cases, strains were characterized for acidurity using ATP-driven bioluminescence and subjected to PCR-determination of potential MS virulence products. Identification of non-MS was determined by 16S rRNA gene sequencing. Sixty-four independent MS or non-MS streptococcal strains were identified. All children contained 1-6 strains. In many patients (N=11), single primary MS strains were identified throughout the dentition. In other patients (N=4), primary MS strains were identified within CLs that were distinct from primary strains found on enamel. Streptococcus gordonii strains were identified as primary strains on enamel or WSLs in four children, and in general were less aciduric than MS strains. Many children with S-ECC contained only a single primary MS strain that was present in both carious and non-carious sites. In some cases, MS and non-cariogenic S. gordonii strains were found to independently exist as dominant strains at different locations within the dentition of individual children, and the aciduric potential of these strains may influence susceptibility in the

Healthcare Provider Perceptions of Causes and Consequences of ICU Capacity Strain in a Large Publicly Funded Integrated Health Region: A Qualitative Study.

PubMed

Bagshaw, Sean M; Opgenorth, Dawn; Potestio, Melissa; Hastings, Stephanie E; Hepp, Shelanne L; Gilfoyle, Elaine; McKinlay, David; Boucher, Paul; Meier, Michael; Parsons-Leigh, Jeanna; Gibney, R T Noel; Zygun, David A; Stelfox, Henry T

2017-04-01

Discrepancy in the supply-demand relationship for critical care services precipitates a strain on ICU capacity. Strain can lead to suboptimal quality of care and burnout among providers and contribute to inefficient health resource utilization. We engaged interprofessional healthcare providers to explore their perceptions of the sources, impact, and strategies to manage capacity strain. Qualitative study using a conventional thematic analysis. Nine ICUs across Alberta, Canada. Nineteen focus groups (n = 122 participants). None. Participants' perspectives on strain on ICU capacity and its perceived impact on providers, families, and patient care were explored. Participants defined "capacity strain" as a discrepancy between the availability of ICU beds, providers, and ICU resources (supply) and the need to admit and provide care for critically ill patients (demand). Four interrelated themes of contributors to strain were characterized (each with subthemes): patient/family related, provider related, resource related, and health system related. Patient/family-related subthemes were "increasing patient complexity/acuity," along with patient-provider communication issues ("paucity of advance care planning and goals-of-care designation," "mismatches between patient/family and provider expectations," and "timeliness of end-of-life care planning"). Provider-related factor subthemes were nursing workforce related ("nurse attrition," "inexperienced workforce," "limited mentoring opportunities," and "high patient-to-nurse ratios") and physician related ("frequent turnover/handover" and "variations in care plan"). Resource-related subthemes were "reduced service capability after hours" and "physical bed shortages." Health system-related subthemes were "variable ICU utilization," "preferential "bed" priority for other services," and "high ward bed occupancy." Participants perceived that strain had negative implications for patients ("reduced quality and safety of care" and

Postmortem aging and freezing and thawing storage enhance ability of early deboned chicken pectoralis major muscle to hold added salt water

USDA-ARS?s Scientific Manuscript database

The effects of postdeboning aging and frozen storage on water-holding capacity (WHC) of chicken breast pectoralis major muscle were investigated. Broiler breast muscle was removed from carcasses either early postmortem (2 h) or later postmortem (24 h). Treatments included: no postdeboning aging; 1-...

The neuroregenerative capacity of olfactory stem cells is not limitless: implications for aging.

PubMed

Child, Kevin M; Herrick, Daniel B; Schwob, James E; Holbrook, Eric H; Jang, Woochan

2018-06-22

The olfactory epithelium (OE) of vertebrates is a highly regenerative neuroepithelium, maintained under normal condition by a population of stem and progenitor cells - globose basal cells (GBCs) that also contribute to epithelial reconstitution after injury. However, aging of the OE often leads to neurogenic exhaustion - the disappearance of both GBCs and olfactory sensory neurons (OSNs). Aneuronal tissue may remain as olfactory, with an uninterrupted sheet of apically arrayed microvillar-capped sustentacular cell, or may undergo respiratory metaplasia. We have generated a transgenic mouse model for neurogenic exhaustion using OMP-driven Tet-off regulation of the A subunit of Diphtheria toxin such that the death of mature OSNs is accelerated. As early as 2 months of age the epithelium of transgenic mice, regardless of sex, recapitulates what is seen in the aged OE of humans and rodents. Areas of the epithelium completely lack neurons and GBCs, while the horizontal basal cells, a reserve stem cell population, show no evidence of activation. Surprisingly, other areas that were olfactory undergo respiratory metaplasia. The impact of accelerated neuronal death and reduced innervation on the olfactory bulb (OB) is also examined. Constant neuronal turnover leaves glomeruli shrunken and impacts the dopaminergic interneurons in the periglomerular layer. Moreover, the acceleration of OSN death can be reversed in those areas where some GBCs persist. However, the projection onto the OB recovers incompletely and the reinnervated glomeruli are markedly altered. Thus, the capacity for OE regeneration is tempered when GBCs disappear. SIGNIFICANCE STATEMENT A large percentage of humans lose or suffer a significant decline in olfactory function as they age. Consequently, quality of life suffers, and safety and nutritional status are put at risk. With age, the OE apparently becomes incapable of fully maintaining the neuronal population of the epithelium despite its well

Effects of Age on Maximal Work Capacity in Women Aged 18-48 Years.

ERIC Educational Resources Information Center

Hartung, G. Harley; And Others

Fifty-six healthy nontrained women aged 18 to 48 were tested for maximal work capacity on a bicycle ergometer. The women were divided into three age groups. A continuous step-increment bicycle ergometer work test was administered with the workload starting at 150 kpm (kilometers per minute) and 50 pedal rpm (revolutions per minute). The workload…

Building Leadership Capacity in Early Childhood Pre-Service Teachers

ERIC Educational Resources Information Center

Campbell-Evans, Glenda; Stamopoulos, Elizabeth; Maloney, Carmel

2014-01-01

Building leadership capacity has emerged as a key concern within the early childhood profession in Australia as the sector responds to recent national reforms focusing on raising standards and improving quality provision of services. The purpose of this paper is to contribute to the discussion around these reforms and to make a case for changes…

Age-related changes in the thermoregulatory capacity of tryptophan-deficient rats.

PubMed

Segall, P E; Timiras, P S

1975-01-01

From a larger study seeking to develop indexes of physiological aging, the present experiment was designed 1) to test thermoregulatory capacity in the aging and old rat subjected to 3 minutes of whole-body ice water immersion, and 2) using this index of physiological age, to determine whether tryptophan deficiency from time of weaning can retard the onset of senescence. Results indicate a progressive prolongation of temperature recovery time from young to middle age to old, and tryptophan-deficient animals restored to commercial diet at middle age show the thermoregulatory capacity of young adults. The implications of tryptophan deficiency with respect to brain development, serotonin metabolism, and temperature regulation are also discussed in terms of the possibility of intervening with the aging process.

Assessment of Capacity in an Aging Society

ERIC Educational Resources Information Center

Moye, Jennifer; Marson, Daniel C.; Edelstein, Barry

2013-01-01

Over the past 40 years, the assessment and scientific study of capacity in older adults has emerged as a distinct field of clinical and research activity for psychologists. This new field reflects the convergence of several trends: the aging of American society, the growing incidence and prevalence of dementia, and the patient rights,…

Planning Decrements in Healthy Aging: Mediation Effects of Fluid Reasoning and Working Memory Capacity.

PubMed

Köstering, Lena; Leonhart, Rainer; Stahl, Christoph; Weiller, Cornelius; Kaller, Christoph P

2016-03-01

Although age-related differences in planning ability are well known, their cognitive foundations remain a matter of contention. To elucidate the specific processes underlying planning decrements in older age, the relative contributions of fluid reasoning, working memory (WM) capacity, and processing speed to accuracy on the Tower of London (TOL) planning task were investigated. Mediation analyses were used to relate overall and search depth-related TOL accuracy from older (N = 106; 60-89 years) and younger adults (N = 69; 18-54 years) to age and measures of fluid reasoning, WM capacity, and speed. For overall planning, fluid abilities mediated the effects of age, WM capacity, and speed in older adults. By contrast, fluid abilities and WM capacity mediated each other in younger adults. For planning accuracy under low demands on the depth of search, WM capacity was specifically important in older age, whereas younger adults recruited both WM capacity and fluid reasoning. Under high search-depth-demands, fluid abilities underlay the cognitive operations critical for resolving move interdependencies in both age groups. Fluid abilities and WM capacity undergo significant changes from younger to older age in their unique contribution to planning, which might represent a mechanism whereby planning decrements in older age are brought about. © 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.

Aging enhances the vulnerability of mesenchymal stromal cells to uniaxial tensile strain-induced apoptosis.

PubMed

McKayed, Katey; Prendergast, Patrick J; Campbell, Veronica A

2016-02-08

Mechanical priming can be employed in tissue engineering strategies to control the fate and differentiation pattern of mesenchymal stromal cells. This is relevant to regenerative medicine whereby mechanical cues can promote the regeneration of a specific tissue type from mesenchymal precursors. The ability of cells to respond to mechanical forces is dependent upon mechanotransduction pathways that involve membrane-associated proteins, such as integrins. During the aging process changes in the mechanotransduction machinery may influence how cells from aged individuals respond to mechanical priming. In this study mesenchymal stromal cells were prepared from young adult and aged rats and exposed to uniaxial tensile strain at 5% and 10% for 3 days, or 2.5% for 7 days. Application of 5% tensile strain had no impact on cell viability. In contrast, application of 10% tensile strain evoked apoptosis and the strain-induced apoptosis was significantly higher in the mesenchymal stromal cells prepared from the aged rats. In parallel to the age-related difference in cellular responsiveness to strain, an age-related decrease in expression of α2 integrin and actin, and enhanced lipid peroxidation was observed. This study demonstrates that mesenchymal stem cells from aged animals have an altered membrane environment, are more vulnerable to the pro-apoptotic effects of 10% tensile strain and less responsive to the pro-osteogenic effects of 2.5% tensile strain. Thus, it is essential to consider how aged cells respond to mechanical stimuli in order to identify optimal mechanical priming strategies that minimise cell loss, particularly if this approach is to be applied to an aged population. Copyright © 2015 Elsevier Ltd. All rights reserved.

Early Selection versus Late Correction: Age-Related Differences in Controlling Working Memory Contents

PubMed Central

Schwarzkopp, Tina; Mayr, Ulrich; Jost, Kerstin

2016-01-01

We examined whether a reduced ability to ignore irrelevant information is responsible for the age-related decline of working-memory (WM) functions. By means of event-related brain potentials we will show that filtering is not out of service in older adults but shifted to a later processing stage. Participants performed a visual short-term memory task (change-detection task) in which targets were presented along with distractors. To allow early selection, a cue was presented in advance of each display, indicating where the targets were to appear. Despite this relatively easy selection criterion, older adults’ filtering was delayed as indicated by the amplitude pattern of the contralateral delay activity. Importantly, WM-equated younger adults did not show a delay indicating that the delay is specific to older adults and not a general phenomenon that comes with low WM capacity. Moreover, the analysis of early visual potentials revealed qualitatively different perceptual/attentional processing between the age groups. Young adults exhibited stronger distractor sensitivity that in turn facilitated filtering. Older adults, in contrast, seemed to initially store distractors and to suppress them after the fact. These early-selection versus late-correction modes suggest an age-related shift in the strategy to control the contents of WM. PMID:27253867

T59. VIRTUAL REALTY ASSESSMENT OF FUNCTIONAL CAPACITY IN EARLY SCHIZOPHRENIA: ASSOCIATIONS WITH NEUROCOGNITION, FUNCTIONAL CAPACITY PERFORMANCE, AND DAILY FUNCTIONING

PubMed Central

Ventura, Joseph; Welikson, Tamara; Subotnik, Kenneth L; Ered, Arielle; Keefe, Richard; Hellemann, Gerhard H; Nuechterlein, Keith H

2018-01-01

Abstract Background Research using virtual reality assessment of functional capacity has shown promise as a reliable and valid way to assess treatment response in patients with established schizophrenia. There has been little work on virtual reality based assessments of functional capacity for patients in the early phase of schizophrenia. We examined whether virtual reality based assessment methods reveal functional capacity deficits in young patients and relevant relationships with established measures of neurocognition, functional capacity performance, and daily functioning. Methods The sample consisted of UCLA Aftercare Research Program patients (n=42) who were diagnosed by trained raters administering the SCID and who met criteria for schizophrenia, schizoaffective disorder, or schizophreniform disorder, and screened normal control subjects (n=13). Patients were within 2 years of their first psychotic episode upon clinic entry, were an average of 23.2 years old, and had an average of 12.9 years of education. The Virtual Reality Functional Capacity Assessment Tool (VRFCAT) was the computer-based measure of functional capacity. We used the MATRICS Consensus Cognitive Battery (MCCB) as an objective measure of neurocognition and the UCSD Performance-Based Skills Assessment (UPSA) to assess functional capacity performance. The Global Functioning Scale: Role and Social, and the Role Functioning Scale were used to assess work and school performance, familial interactions, and social functioning. Results We were able to confirm that the deficit in functional capacity performance measured using VRFCAT is present in the early course of schizophrenia in that the patients were slower and committed more errors (M=830.41) as compared with normal controls (M=716.84; t=3.0, p<.01). Virtual reality based assessment of functional capacity was correlated with objective measures of neurocognition (MCCB Overall Composite), r=-.71, p=<.01, standard approaches to functional capacity

Does Active Memory Capacity Change with Age?

ERIC Educational Resources Information Center

Halford, Graeme S.; And Others

A series of experiments, which used the primary memory paradigm of Wickens et al. (1981, 1985) with university students, adults, and 8- and 9-year-old children, found an increase in primary memory capacity with age. Primary memory differs from secondary memory in that the latter is susceptible to proactive interference, whereas the former is not.…

[Fat emulsion tolerance in preterm infants of different gestational ages in the early stage after birth].

PubMed

Tang, Hui; Yang, Chuan-Zhong; Li, Huan; Wen, Wei; Huang, Fang-Fang; Huang, Zhi-Feng; Shi, Yu-Ping; Yu, Yan-Liang; Chen, Li-Lian; Yuan, Rui-Qin; Zhu, Xiao-Yu

2017-06-01

To investigate the fat emulsion tolerance in preterm infants of different gestational ages in the early stage after birth. A total of 98 preterm infants were enrolled and divided into extremely preterm infant group (n=17), early preterm infant group (n=48), and moderate-to-late preterm infant group (n=33). According to the dose of fat emulsion, they were further divided into low- and high-dose subgroups. The umbilical cord blood and dried blood filter papers within 3 days after birth were collected. Tandem mass spectrometry was used to measure the content of short-, medium-, and long-chain acylcarnitines. The extremely preterm infant and early preterm infant groups had a significantly lower content of long-chain acylcarnitines in the umbilical cord blood and dried blood filter papers within 3 days after birth than the moderate-to-late preterm infant group (P<0.05), and the content was positively correlated with gestational age (P<0.01). On the second day after birth, the low-dose fat emulsion subgroup had a significantly higher content of short-, medium-, and long-chain acylcarnitines than the high-dose fat emulsion subgroup among the extremely preterm infants (P<0.05). In the early preterm infant and moderate-to-late preterm infant groups, there were no significant differences in the content of short-, medium-, and long-chain acylcarnitines between the low- and high-dose fat emulsion subgroups within 3 days after birth. Compared with moderate-to-late preterm infants, extremely preterm infants and early preterm infants have a lower capacity to metabolize long-chain fatty acids within 3 days after birth. Early preterm infants and moderate-to-late preterm infants may tolerate high-dose fat emulsion in the early stage after birth, but extremely preterm infants may have an insufficient capacity to metabolize high-dose fat emulsion.

Do schizophrenia patients age early?

PubMed

Shivakumar, Venkataram; Kalmady, Sunil V; Venkatasubramanian, Ganesan; Ravi, Vasanthapuram; Gangadhar, Bangalore N

2014-08-01

The etiopathogenesis of schizophrenia is poorly understood. Within the proposed "neurodegeneration paradigm", observations have been put forth for "accelerated aging" in this disorder. This proposition is largely based on the neuroscience research that demonstrates progressive changes in brain as well as other systemic abnormalities supportive of faster aging process in patients with this disorder. In this review, we have summarized the literature related to the concept of early aging in schizophrenia. These studies include P300 abnormalities & visual motion discrimination, neuroimaging findings, telomere dynamics as well as neuropathology of related brain regions. We also propose a role of vitamin D, neuroimmunological changes and elevated oxidative stress as well as mitochondrial dysfunction in addition to the above factors with 'vitamin-D deficiency' as the central paradox. Put together, the evidence supporting early aging in schizophrenia is compelling and this requires further systematic studies. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of strain and age on the mechanical properties of rat Achilles tendons

PubMed Central

Vafek, Emily C.; Plate, Johannes F.; Friedman, Eric; Mannava, Sandeep; Scott, Aaron T.; Danelson, Kerry A.

2017-01-01

Summary Background Achilles tendon (AT) ruptures are common in the middle age population; however, the pathophysiology and influence of age on AT ruptures is not fully understood. This study evaluates the effect and interactions between, strain and age on the in vitro biomechanical properties of ATs. Methods Bilateral ATs were harvested from 17 young (8 months) and 14 middle-aged (24 months) rats and underwent stress-relaxation using Fung’s quasilinear viscoelastic (QLV) modeling and load-to-failure testing. Results The initial viscoelastic response (parameter B) in middle-age animals was dependent on the amount of strain applied to the tendon and was significantly increased in middle-aged animals at higher strain. Higher strain in older animals led to a prolonged relaxation time (parameter tau 2). There was a trend toward an increased magnitude of the relaxation response (parameter C) at higher strain in the middle-aged animals. Middle-aged animals had a significantly lower mean stress at ultimate failure (p=0.01), while Young’s modulus was similar in both groups (p=0.46). Conclusions The passive biomechanical properties of the rat AT change with age and the influence stress-relaxation response of the AT, thereby possibly predisposing the AT of older animals to fail at lower loads compared to younger animals. Level of evidence Not applicable, this is a basic science study. PMID:29387650

A new human male diploid cell strain, TIG-7: its age-related changes and comparison with a matched female TIG-1 cell strain.

PubMed

Yamamoto, K; Kaji, K; Kondo, H; Matsuo, M; Shibata, Y; Tasaki, Y; Utakoji, T; Ooka, H

1991-01-01

A new human diploid cell strain, TIG-7, which has the male karyotype, was established and characterized. Isozyme and histocompatibility typing of the cell strain was performed. The average in vitro life span of the cells is 73 population doublings. Changes in cell volume, doubling time, saturation density, the efficiency of cell attachment, plating efficiency, and relative DNA content were examined during in vitro cellular aging. Hydrocortisone slightly prolongs the life span of the cell strain when the hormone is administered to the cultures during middle passages. The age-related changes in the parameters of TIG-7 are not appreciably different from those of the previously established TIG-1 cell strain. These results show that this cell strain is useful for research on cellular aging; further profit is anticipated from research using a combination of these two sexually different cell strains.

The development of inter-strain variation in cortical and trabecular traits during growth of the mouse lumbar vertebral body.

PubMed

Ramcharan, M A; Faillace, M E; Guengerich, Z; Williams, V A; Jepsen, K J

2017-03-01

How cortical and trabecular bone co-develop to establish a mechanically functional structure is not well understood. Comparing early postnatal differences in morphology of lumbar vertebral bodies for three inbred mouse strains identified coordinated changes within and between cortical and trabecular traits. These early coordinate changes defined the phenotypic differences among the inbred mouse strains. Age-related changes in cortical and trabecular traits have been well studied; however, very little is known about how these bone tissues co-develop from day 1 of postnatal growth to establish functional structures by adulthood. In this study, we aimed to establish how cortical and trabecular tissues within the lumbar vertebral body change during growth for three inbred mouse strains that express wide variation in adult bone structure and function. Bone traits were quantified for lumbar vertebral bodies of female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse strains from 1 to 105 days of age (n = 6-10 mice/age/strain). Inter-strain differences in external bone size were observed as early as 1 day of age. Reciprocal and rapid changes in the trabecular bone volume fraction and alignment in the direction of axial compression were observed by 7 days of age. Importantly, the inter-strain difference in adult trabecular bone volume fraction was established by 7 days of age. Early variation in external bone size and trabecular architecture was followed by progressive increases in cortical area between 28 and 105 days of age, with the greatest increases in cortical area seen in the mouse strain with the lowest trabecular mass. Establishing the temporal changes in bone morphology for three inbred mouse strains revealed that genetic variation in adult trabecular traits were established early in postnatal development. Early variation in trabecular architecture preceded strain-specific increases in cortical area and changes in cortical thickness. This study

Improvement of the Insecticidal Capacity of Two Purpureocillium Lilacinum Strains against Tribolium Confusum.

PubMed

Barra, Paula; Etcheverry, Miriam; Nesci, Andrea

2015-03-18

Entomopathogenic fungi can regulate insect populations. They have extracellular enzymes that degrade cuticle components, mainly hydrocarbons, used as an energy source. The increase in insecticidal activity of fungi in a medium supplemented with cuticular hydrocarbons was assayed and the hydrolytic enzyme profiles of two strains of Purpureocillium lilacinum were evaluated. A spore suspension of P. lilacinum was inoculated in Petri plates with different values (0.99-0.97-0.95) of water activity (Aw) using the substrates gelatin, starch and tween-20. Growth rate on the different substrates and the enzymatic activity index for proteases, amylases and lipases at different incubation times, pH and Aw, was evaluated. Moreover, the insecticidal efficiency of strains grown in media supplemented with n-hexadecane and n-octacosane was analyzed. LT50 was calculated against adults of Tribolium confusum and showed that mortality increased about 15% when the strains grew in amended culture medium. High amylolytic activity was detected, but proteases were the main enzymes produced. Optimal protease production was observed in a range of acid and alkaline pH and lower Aw. The greatest growth rate was obtained in presence of gelatin. Lipase and amylase production was detected in small amounts. Fungal growth in media with hydrocarbon mixtures increased the pathogenicity of the two strains of P. lilacinum, with the strain JQ926223 being more virulent. The information obtained is important for achieving both an increase in insecticidal capacity and an understanding of physiological adaptation of the fungus.

The Healthy Aging Research Network: Resources for Building Capacity for Public Health and Aging Practice

PubMed Central

Wilcox, Sara; Altpeter, Mary; Anderson, Lynda A.; Belza, Basia; Bryant, Lucinda; Jones, Dina L.; Leith, Katherine H.; Phelan, Elizabeth A.; Satariano, William A.

2015-01-01

There is an urgent need to translate science into practice and help enhance the capacity of professionals to deliver evidence-based programming. We describe contributions of the Healthy Aging Research Network in building professional capacity through online modules, issue briefs, monographs, and tools focused on health promotion practice, physical activity, mental health, and environment and policy. We also describe practice partnerships and research activities that helped inform product development and ways these products have been incorporated into real-world practice to illustrate possibilities for future applications. Our work aims to bridge the research-to-practice gap to meet the demands of an aging population. PMID:24000962

Dynamic strain aging in the high-temperature low-cycle fatigue of SA508 Cl. 3 forging steel

NASA Astrophysics Data System (ADS)

Lee, Byung Ho; Kim, In Sup

1995-10-01

The effect of dynamic strain aging on cyclic stress response and fatigue resistance of ASME SA508 Cl.3 forging steel for nuclear reactor pressure vessels has been evaluated in the temperature range of room temperature to 500°C. Total strain ranges and strain rates were varied from 0.7 to 2.0% and from 4 × 10 -4 to 1 × 10 -2 s -1, respectively. The cyclic stress response depended on the testing temperature, strain rate, and range. Generally, the initial cyclic hardening was immediately followed by cyclic softening at all strain rates. However, at 300°C, the operating temperature of nuclear reactor pressure vessels, the variation of cyclic stress amplitude showed the primary and secondary hardening stages dependent on the strain rate and strain range. Dynamic strain aging was manifested by enhanced cyclic hardening, distinguished secondary hardening, and negative strain rate sensitivity. A modified cell shutting model was described for the onset of the secondary hardening due to the dynamic strain aging and it was in good agreement with the experimental results. Fatigue life increased in strain rate at all testing temperatures. Specifically the fatigue life was longer at the dynamic strain aging temperature. Further, the dynamic strain aging was easy to initiate the crack, while crack propagation was retarded by crack branching and suppression of plastic zone, hence the dynamic strain aging caused the improvement of fatigue resistance.

Aged mice display an altered pulmonary host response to Francisella tularensis live vaccine strain (LVS) infections

PubMed Central

CA, Mares; SS, Ojeda; Q, Li; EG, Morris; JJ, Coalson; JM, Teale

2012-01-01

Aging is a complex phenomenon that has been shown to affect many organ systems including the innate and adaptive immune systems. The current study was designed to examine the potential effect of immunosenescence on the pulmonary immune response using a Francisella tularensis live vaccine strain (LVS) inhalation infection model. F. tularensis is a gram-negative intracellular pathogen that can cause a severe pneumonia.In this study both young (8-12 week old) and aged (20-24 month old) mice were infected intranasally with LVS. Lung tissues from young and aged mice were used to assess pathology, recruitment of immune cell types and cytokine expression levels at various times post infection. Bacterial burdens were also assessed. Interestingly, the lungs of aged animals harbored fewer organisms at early time points of infection (day 1, day 3) compared with their younger counterparts. In addition, only aged animals displayed small perivascular aggregates at these early time points that appeared mostly mononuclear in nature. However, the kinetics of infiltrating polymorphonuclear neutrophils (PMNs) and increased cytokine levels measured in the bronchial alveolar lavage fluid (BALF) were delayed in infected aged animals relative to young infected animals with neutrophils appearing at day 5 post infection (PI) in the aged animals as opposed to day 3 PI in the young infected animals. Also evident were alterations in the ratios of mononuclear to PMNs at distinct post infection times. The above evidence indicates that aged mice elicit an altered immune response in the lung to respiratory Francisella tularensis LVS infections compared to their younger counterparts. PMID:19825409

Age of Legal Capacity (Scotland) Act 1991. [Excerpt. 25 July 1991].

PubMed

1991-01-01

Section 1 of this Act provides as a general rule that persons under the age of 16 shall have no legal capacity to enter into transactions, but that persons over the age of 16 shall have such legal capacity. Section 1 also provides that this general rule does not apply to cases involving transactions entered into before the commencement of the Act, does not affect the criminal responsibility of any person or legislation in which specific ages are stipulated, and does not prevent a person under age 16 from receiving or holding any right, title, or interest or exercising parental rights with respect to his or her child. Section 2 makes further exceptions to this rule for persons under the age of 16 with respect to reasonable transactions commonly entered into by children, making a will, consenting to adoption, and consenting to medical treatment. Among other things, it provides that "a person under the age of 16 years shall have legal capacity to consent on his own behalf to any surgical, medical, or dental procedure or treatment where, in the opinion of a qualified medical practitioner attending him, he is capable of understanding the nature and possible consequences of the procedure or treatment." Further provisions of the Act authorize a court to set aside transactions made by a person between the ages of 16 and 18 that are prejudicial transactions (Section 3) and to ratify proposed transactions by persons of the same age (Section 4). This Act is applicable only to Scotland.

Early-Life Intelligence Predicts Midlife Biological Age

PubMed Central

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

2016-01-01

Objectives: 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. Methods: 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. Results: 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. Discussion: 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. PMID:26014827

Improvement of the Insecticidal Capacity of Two Purpureocillium Lilacinum Strains against Tribolium Confusum

PubMed Central

Barra, Paula; Etcheverry, Miriam; Nesci, Andrea

2015-01-01

Entomopathogenic fungi can regulate insect populations. They have extracellular enzymes that degrade cuticle components, mainly hydrocarbons, used as an energy source. The increase in insecticidal activity of fungi in a medium supplemented with cuticular hydrocarbons was assayed and the hydrolytic enzyme profiles of two strains of Purpureocillium lilacinum were evaluated. A spore suspension of P. lilacinum was inoculated in Petri plates with different values (0.99–0.97–0.95) of water activity (Aw) using the substrates gelatin, starch and tween-20. Growth rate on the different substrates and the enzymatic activity index for proteases, amylases and lipases at different incubation times, pH and Aw, was evaluated. Moreover, the insecticidal efficiency of strains grown in media supplemented with n-hexadecane and n-octacosane was analyzed. LT50 was calculated against adults of Tribolium confusum and showed that mortality increased about 15% when the strains grew in amended culture medium. High amylolytic activity was detected, but proteases were the main enzymes produced. Optimal protease production was observed in a range of acid and alkaline pH and lower Aw. The greatest growth rate was obtained in presence of gelatin. Lipase and amylase production was detected in small amounts. Fungal growth in media with hydrocarbon mixtures increased the pathogenicity of the two strains of P. lilacinum, with the strain JQ926223 being more virulent. The information obtained is important for achieving both an increase in insecticidal capacity and an understanding of physiological adaptation of the fungus. PMID:26463076

Effect of early postnatal exposure to valproate on neurobehavioral development and regional BDNF expression in two strains of mice.

PubMed

Bath, Kevin G; Pimentel, Tiare

2017-05-01

Valproate has been used for over 30years as a first-line treatment for epilepsy. In recent years, prenatal exposure to valproate has been associated with teratogenic effects, limiting its use in women that are pregnant or of childbearing age. However, despite its potential detrimental effects on development, valproate continues to be prescribed at high rates in pediatric populations in some countries. Animal models allow us to test hypotheses regarding the potential effects of postnatal valproate exposure on neurobehavioral development, as well as identify potential mechanisms mediating observed effects. Here, we tested the effect of early postnatal (P4-P11) valproate exposure (100mg/kg and 200mg/kg) on motor and affective development in two strains of mice, SVE129 and C57Bl/6N. We also assessed the effect of early valproate exposure on regional BDNF protein levels, a potential target of valproate, and mediator of neurodevelopmental outcomes. We found that early life valproate exposure led to significant motor impairments in both SVE129 and C57Bl/6N mice. Both lines of mice showed significant delays in weight gain, as well as impairments in the righting reflex (P7-8), wire hang (P17), open field (P12 and P21), and rotarod (P25 and P45) tasks. Interestingly, some of the early locomotor effects were strain- and dose-dependent. We observed no effects of valproate on early markers of anxiety-like behavior. Importantly, early life valproate exposure had significant effects on regional BDNF expression, leading to a near 50% decrease in BDNF levels in the cerebellum of both strains of mice, while not impacting hippocampal BDNF protein levels. These observations indicate that postnatal exposure to valproate may have significant, and region-specific effects, on neural and behavioral development, with specific consequences for cerebellar development and motor function. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

Sarcopenia and age-related changes in body composition and functional capacity.

PubMed

Evans, W J; Campbell, W W

1993-02-01

Advancing adult age is associated with profound changes in body composition. One of the most prominent of these changes is sarcopenia, defined as the age-related loss in skeletal muscle mass, which results in decreased strength and aerobic capacity and thus functional capacity. Sarcopenia is also closely linked to age-related losses in bone mineral, basal metabolic rate and increased body fat content. Through physical exercise and training, especially resistance training, it may be possible to prevent sarcopenia and the remarkable array of associated abnormalities, such as type II diabetes, coronary artery disease, hypertension, osteoporosis and obesity. Using an exercise program of sufficient frequency, intensity and duration, it is quite possible to increase muscle strength and endurance at any age. There is no pharmacological intervention that holds a greater promise of improving health and promoting independence in the elderly than does exercise.

Effect of Saccharomyces strains on the quality of red wines aged on lees.

PubMed

Loira, I; Vejarano, R; Morata, A; Ricardo-da-Silva, J M; Laureano, O; González, M C; Suárez-Lepe, J A

2013-08-15

Ageing on lees involves ageing the wine in contact with yeast cells after fermentation. If combined with the addition of oak chips, it can soften the wood flavour and increase the aromatic complexity of wine. The aim of the present work is to optimise both ageing techniques through selection of an adequate Saccharomyces cerevisiae strain. The study lasted 6 months and content of polysaccharides, anthocyanins, proanthocyanidins, volatile compounds, colour parameters and sensory analysis, were periodically evaluated. Among the strains tested, G37 showed the highest release of polysaccharides (24.4±5.5 mg l(-1)). Vanillin, syringaldehyde and furfuryl alcohol increased with ageing time in 7VA2 treatment. The wine aged with CTPL14 strain presented fewer monomeric and oligomeric proanthocyanidins (12.4±0.6 and 83.4±8.3 mg l(-1), respectively), and showed the lowest astringency and bitterness sensations. Results show an improvement in the sensory profile of the red wine aged with a combination of these two techniques. Copyright © 2013 Elsevier Ltd. All rights reserved.

Implementing an innovative intervention to increase research capacity for enhancing early psychosis care in Indonesia.

PubMed

Renwick, L; Irmansyah; Keliat, B A; Lovell, K; Yung, A

2017-11-01

WHAT IS KNOWN ON THE TOPIC?: In low- and middle-income settings (LMICs) such as Indonesia, the burden from psychotic illness is significant due to large gaps in treatment provision Mental health workers and community nurses are a growing workforce requiring new evidence to support practice and enhanced roles and advanced competencies among UK mental health nurses also requires greater research capacity Research capacity building projects can strengthen research institutions, enhance trial capacity, improve quality standards and improve attitudes towards the importance of health research. WHAT THIS PAPER ADDS?: Delivering innovative, cross-cultural workshops to enhance research capacity to multidisciplinary, early career researchers in Indonesia and the UK are rated highly by attendees Supporting people in this way helps them to gain competitive grant funding to complete their own research which can improve the health of the population To our knowledge, there are no other studies reporting the attainment of grant income as a successful outcome of international research partnerships for mental health nursing so our finding is novel. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This method could be implemented to improve networking and collaboration between UK academics and early career researchers in other lower- and middle-income settings This strategy can also strengthen existing partnerships among early career researchers in the UK to meet the demands for greater research mentorship and leadership among mental health nurses and enhance nurses capabilities to contribute to evidence for practice. Aim To strengthen research capacity for nurses and early career researchers in Indonesia and the UK to develop a local evidence base in Indonesia to inform policy and improve the nation's health. These strategies can strengthen research institutions, enhance trial capacity, improve quality standards and improve attitudes towards the importance of health research. Methods Four

Vitamin C and E Supplements Enhance the Antioxidant Capacity of Erythrocytes Obtained from Aged Rats.

PubMed

Xiong, Yanlian; Xiong, Yanlei; Zhou, Shuai; Sun, Yanan; Zhao, Yuqi; Ren, Xiaotong; Zhang, Yingfang; Zhang, Naili

2017-04-01

The main purpose of the present study was to investigate the effects of vitamin C and E supplements on the antioxidant capacity of erythrocytes obtained from young and aged rats. Male Wistar rats aged 3 and 24 months were used. Vitamins C and E were injected at doses of 200 mg/kg (day) intraperitoneally in young and aged groups. The antioxidant capacity, oxidant stress parameters, and deformability of red blood cells collected from different age stages were evaluated. An in vitro oxidation system was constructed to explore the mechanisms of antioxidant capacity change in the vitamin treatment groups. Treatment with vitamins C and E can effectively restore the antioxidant capacity and deformability of red blood cells (RBCs) in aged rats. Under in vitro oxidative conditions, an age-dependent decline in the influx rate of L-cysteine was observed. This was significantly improved following treatment with vitamins C and E. We present evidence of an improvement in the antioxidant capacity of RBCs by treatment with vitamins C and E in aged rats. These observations also suggest that treatment with vitamins C and E improves glutathione synthesis by enhancing the influx rate of L-cysteine through the modification of membrane proteins and lipids.

Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

PubMed

Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

2009-05-01

The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

Estimating risks of heat strain by age and sex: a population-level simulation model.

PubMed

Glass, Kathryn; Tait, Peter W; Hanna, Elizabeth G; Dear, Keith

2015-05-18

Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan's man model "MANMO") to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions.

Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs) by a Newly Isolated Strain from Oilfield Produced Water

PubMed Central

Qi, Yi-Bin; Wang, Chen-Yu; Lv, Cheng-Yuan; Lun, Zeng-Min; Zheng, Cheng-Gang

2017-01-01

The polycyclic aromatic hydrocarbon (PAH)-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA–DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM) and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA) and gas chromatography–mass spectrometry (GC–MS) analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution. PMID:28241412

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

Thermo-mechanical simulations of early-age concrete cracking with durability predictions

NASA Astrophysics Data System (ADS)

Havlásek, Petr; Šmilauer, Vít; Hájková, Karolina; Baquerizo, Luis

2017-09-01

Concrete performance is strongly affected by mix design, thermal boundary conditions, its evolving mechanical properties, and internal/external restraints with consequences to possible cracking with impaired durability. Thermo-mechanical simulations are able to capture those relevant phenomena and boundary conditions for predicting temperature, strains, stresses or cracking in reinforced concrete structures. In this paper, we propose a weakly coupled thermo-mechanical model for early age concrete with an affinity-based hydration model for thermal part, taking into account concrete mix design, cement type and thermal boundary conditions. The mechanical part uses B3/B4 model for concrete creep and shrinkage with isotropic damage model for cracking, able to predict a crack width. All models have been implemented in an open-source OOFEM software package. Validations of thermo-mechanical simulations will be presented on several massive concrete structures, showing excellent temperature predictions. Likewise, strain validation demonstrates good predictions on a restrained reinforced concrete wall and concrete beam. Durability predictions stem from induction time of reinforcement corrosion, caused by carbonation and/or chloride ingress influenced by crack width. Reinforcement corrosion in concrete struts of a bridge will serve for validation.

Maximum step length: relationships to age and knee and hip extensor capacities.

PubMed

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2007-07-01

Maximum Step Length may be used to identify older adults at increased risk for falls. Since leg muscle weakness is a risk factor for falls, we tested the hypotheses that maximum knee and hip extension speed, strength, and power capacities would significantly correlate with Maximum Step Length and also that the "step out and back" Maximum Step Length [Medell, J.L., Alexander, N.B., 2000. A clinical measure of maximal and rapid stepping in older women. J. Gerontol. A Biol. Sci. Med. Sci. 55, M429-M433.] would also correlate with the Maximum Step Length of its two sub-tasks: stepping "out only" and stepping "back only". These sub-tasks will be referred to as versions of Maximum Step Length. Unimpaired younger (N=11, age=24[3]years) and older (N=10, age=73[5]years) women performed the above three versions of Maximum Step Length. Knee and hip extension speed, strength, and power capacities were determined on a separate day and regressed on Maximum Step Length and age group. Version and practice effects were quantified and subjective impressions of test difficulty recorded. Hypotheses were tested using linear regressions, analysis of variance, and Fisher's exact test. Maximum Step Length explained 6-22% additional variance in knee and hip extension speed, strength, and power capacities after controlling for age group. Within- and between-block and test-retest correlation values were high (>0.9) for all test versions. Shorter Maximum Step Lengths are associated with reduced knee and hip extension speed, strength, and power capacities after controlling for age. A single out-and-back step of maximal length is a feasible, rapid screening measure that may provide insight into underlying functional impairment, regardless of age.

Myocardial strain in healthy adults across a broad age range as revealed by cardiac magnetic resonance imaging at 1.5 and 3.0T: Associations of myocardial strain with myocardial region, age, and sex.

PubMed

Mangion, Kenneth; Clerfond, Guillaume; McComb, Christie; Carrick, David; Rauhalammi, Samuli M; McClure, John; Corcoran, David S; Woodward, Rosemary; Orchard, Vanessa; Radjenovic, Aleksandra; Zhong, Xiaodong; Berry, Colin

2016-11-01

To assess myocardial strain using cine displacement encoding with stimulated echoes (DENSE) using 1.5T and 3.0T MRI in healthy adults. Healthy adults without any history of cardiovascular disease underwent magnetic resonance imaging (MRI) at 1.5T and 3.0T within 2 days. The MRI protocol included balanced steady-state free-precession (b-SSFP), 2D cine-echo planar imaging (EPI)-DENSE, and late gadolinium enhancement in subjects >45 years. Acquisitions were divided into six segments; global and segmental peak longitudinal and circumferential strain were derived and analyzed by field strength, age, and gender. In all, 89 volunteers (mean age 44.8 ± 18.0 years, range: 18-87 years) underwent MRI at 1.5T, and 88 of these subjects underwent MRI at 3.0T (1.4 ± 1.4 days between the scans). Compared with 3.0T, the magnitudes of global circumferential (-19.5 ± 2.6% vs. -18.47 ± 2.6%; P = 0.001) and longitudinal (-12.47 ± 3.2% vs. -10.53 ± 3.1%; P = 0.004) strain were greater at 1.5T. At 1.5T, longitudinal strain was greater in females than in males: -10.17 ± 3.4% vs. -13.67 ± 2.4%; P = 0.001. Similar observations occurred for circumferential strain at 1.5T (-18.72 ± 2.2% vs. -20.10 ± 2.7%; P = 0.014) and at 3.0T (-17.92 ± 1.8% vs. -19.1 ± 3.1%; P = 0.047). At 1.5T, longitudinal and circumferential strain were not associated with age after accounting for sex (longitudinal strain P = 0.178, circumferential strain P = 0.733). At 3.0T, longitudinal and circumferential strain were associated with age (P < 0.05). Longitudinal strain values were greater in the apico-septal, basal-lateral, and mid-lateral segments and circumferential strain in the inferior, infero-lateral, and antero-lateral LV segments. Myocardial strain parameters as revealed by cine-DENSE at different MRI field strengths were associated with myocardial region, age, and sex. J. Magn. Reson. Imaging 2016;44:1197-1205. © 2016 The Authors Journal of Magnetic Resonance Imaging published by Wiley Periodicals

Behind the Starting Line: School Capacity Building in Early Childhood Education

ERIC Educational Resources Information Center

Ho, Dora; Chen, Shu-Chin Susan

2013-01-01

This paper describes the process of school capacity building in Hong Kong's early childhood education at a time when there was a quest for quality education. A local preschool was selected for the study, which took part in a university-school support programme through which consultancy was hired from a university to provide school-based support.…

[Study on the neutralization capacity of different types of human measles virus vaccine and the epidemic strains].

PubMed

Feng, Yan; Lu, Yi-yu; Yan, Ju-ying; Jiang, Xiao-hui; Shi, Wen; Xu, Chang-ping; Li, Zhen

2007-11-01

To explore the neutralization capacities of different types of human serum to measles virus epidemic strains and vaccine strain. Neutralization antibody (NT) to Shanghai 191 and measles virus isolates in 2005 were tested using acute and convalescent serum samples from diagnosed measles patients, children serum samples collected before and after vaccination and serum samples of migrant residents, from 3 different regions. Additionally, animal immune serum referring to vaccine strain and 3 epidemic strains were prepared and used to undergo crossing neutralization test with corresponding strains mentioned-above. Antigenic ratios were calculated. GMT value of NT of after-immune serum to vaccine strains was 50.82,1.86 times higher than that to MVi/ZJ/05/7 (GMT was 27.35), whereas GMT value of convalescent serum to MVi/ZJ/05/7 (GMT was 386.95) was obviously higher than that to vaccine strain (GMT was 1:151.83),and GMT value of migrant residents' serum in 3 regions to MVi/ZJ/05/7 were 2.22-4.17 times lower than that to vaccine strain. Meanwhile,the antigenic ratios between MVi/ZJ/ 99/1, MVi/ZJ/04/1, MVi/ZJ/05/7 and vaccine strain were found to be 4.28,5.24 and 5.66 respectively. Additionally,low NT titers to vaccine strain were found in patients' acute sera and GMT value was over 1:4. There were obvious differences on neutralization antibody of different types of serum to measles vaccine strain and epidemic strains which indicating the antigenic diversity of epidemic strains had influenced the protective effectiveness of vaccine antibody to epidemic strains. It was of significance to carry on research projects on the antigenic diversity and effectiveness of measles vaccine.

Dynamic Strain Aging of Nickel-Base Alloys 800H and 690

NASA Astrophysics Data System (ADS)

Moss, Tyler E.; Was, Gary S.

2012-10-01

The objective of the current investigation is to characterize the dynamic strain aging (DSA) behavior in alloys 800H and 690. Constant extension rate tests were conducted at strain rates in the range of 10-4 s-1 to 10-7 s-1and temperatures between 295 K and 673 K (22 °C and 400 °C), in an argon atmosphere. Maps for the occurrence of serrated flow as a function of strain rate and temperature were built for both alloys. The enthalpy of serrated flow appearance of alloy 800H was found to be 1.07 ± 0.30 eV.

Exercise training improves in vivo endothelial repair capacity of early endothelial progenitor cells in subjects with metabolic syndrome.

PubMed

Sonnenschein, Kristina; Horváth, Tibor; Mueller, Maja; Markowski, Andrea; Siegmund, Tina; Jacob, Christian; Drexler, Helmut; Landmesser, Ulf

2011-06-01

Endothelial dysfunction and injury are considered to contribute considerably to the development and progression of atherosclerosis. It has been suggested that intense exercise training can increase the number and angiogenic properties of early endothelial progenitor cells (EPCs). However, whether exercise training stimulates the capacity of early EPCs to promote repair of endothelial damage and potential underlying mechanisms remain to be determined. The present study was designed to evaluate the effects of moderate exercise training on in vivo endothelial repair capacity of early EPCs, and their nitric oxide and superoxide production as characterized by electron spin resonance spectroscopy analysis in subjects with metabolic syndrome. Twenty-four subjects with metabolic syndrome were randomized to an 8 weeks exercise training or a control group. Superoxide production and nitric oxide (NO) availability of early EPCs were characterized by using electron spin resonance (ESR) spectroscopy analysis. In vivo endothelial repair capacity of EPCs was examined by transplantation into nude mice with defined carotid endothelial injury. Endothelium-dependent, flow-mediated vasodilation was analysed using high-resolution ultrasound. Importantly, exercise training resulted in a substantially improved in vivo endothelial repair capacity of early EPCs (24.0 vs 12.7%; p < 0.05) and improved endothelium-dependent vasodilation. Nitric oxide production of EPCs was substantially increased after exercise training, but not in the control group. Moreover, exercise training reduced superoxide production of EPCs, which was not observed in the control group. The present study suggests for the first time that moderate exercise training increases nitric oxide production of early endothelial progenitor cells and reduces their superoxide production. Importantly, this is associated with a marked beneficial effect on the in vivo endothelial repair capacity of early EPCs in subjects with

Manifestations of Dynamic Strain Aging in Soft-Oriented NiAl Single Crystals

NASA Technical Reports Server (NTRS)

Weaver, M. L.; Kaufman, M. J.; Noebe, R. D.

1996-01-01

The tensile and compressive properties of six NiAl-base single-crystal alloys have been investigated at temperatures between 77 and 1200 K. The normalized critical resolved shear stresses (CRSS/E) and work-hardening rates (Theta/E) for these alloys generally decreased with increasing temperature. However, anomalous peaks or plateaus for these properties were observed in conventional purity (CPNiAl), Si-doped (NiAl-Si), C-doped low Si (UF-NiAl1), and Mo-doped (NiAl-Mo) alloys at intermediate temperatures (600 to 1000 K). This anomalous behavior was not observed in high-purity, low interstitial material (HP-NiAl). Low or negative strain-rate sensitivities (SRS) also were observed in all six alloys in this intermediate temperature range. Coincident with the occurrence of negative strain-rate sensitivities was the observation of serrated stress-strain curves in the CPNiAl and NiAl-Si alloys. These phenomena have been attributed to dynamic strain aging (DSA). Chemical analysis of the alloys used in this study suggests that the main specie responsible for strain aging in NiAl is C but indicate that residual Si impurities can enhance the strain aging effects. The corresponding dislocation microstructures at low temperatures (300 to 600 K) were composed of well-defined cells. At intermediate temperatures (600 to 900 K), either poorly defined cells or coarse bands of localized slip, reminiscent of the vein structures observed in low-cycle fatigue specimens deformed in the DSA regime, were observed in conventional purity, Si-doped, and in Mo-doped alloys. In contrast, a well-defined cell structure persisted in the low interstitial, high-purity alloy. At elevated temperatures (greater than or equal to 1000 K), more uniformly distributed dislocations and sub-boundaries were observed in all alloys. These observations are consistent with the occurrence of DSA in NiAl single-crystal alloys at intermediate temperatures.

Regional frontal gray matter volume associated with executive function capacity as a risk factor for vehicle crashes in normal aging adults.

PubMed

Sakai, Hiroyuki; Takahara, Miwa; Honjo, Naomi F; Doi, Shun'ichi; Sadato, Norihiro; Uchiyama, Yuji

2012-01-01

Although low executive functioning is a risk factor for vehicle crashes among elderly drivers, the neural basis of individual differences in this cognitive ability remains largely unknown. Here we aimed to examine regional frontal gray matter volume associated with executive functioning in normal aging individuals, using voxel-based morphometry (VBM). To this end, 39 community-dwelling elderly volunteers who drove a car on a daily basis participated in structural magnetic resonance imaging, and completed two questionnaires concerning executive functioning and risky driving tendencies in daily living. Consequently, we found that participants with low executive function capacity were prone to risky driving. Furthermore, VBM analysis revealed that lower executive function capacity was associated with smaller gray matter volume in the supplementary motor area (SMA). Thus, the current data suggest that SMA volume is a reliable predictor of individual differences in executive function capacity as a risk factor for vehicle crashes among elderly persons. The implication of our results is that regional frontal gray matter volume might underlie the variation in driving tendencies among elderly drivers. Therefore, detailed driving behavior assessments might be able to detect early neurodegenerative changes in the frontal lobe in normal aging adults.

Changes in physical capacity among middle-aged municipal employees over 16 years.

PubMed

Savinainen, Minna; Nygård, Clas-Håkan; Korhonen, Olli; Ilmarinen, Juhani

2004-01-01

The purpose of the present study was to identify changes in different components of physical capacity among middle-aged women and men employed in the municipal branch for 16 years. The data were obtained by laboratory measurements and postal questionnaires. The study group consisted of 45 middle-aged subjects, who were on average 51.5 years old at the beginning of the follow-up in 1981 and 67.3 years in 1997. During the 16-year follow-up period, the average physical capacity of these workers decreased by approximately 20%. The study showed that the greatest changes occurred in isometric trunk muscle strength and in the flexibility of the spine, whereas smaller changes were noted in anthropometrics. The decrease of physical capacity was greater among men (range 11.6% to 33.7%) than among women (range 3.3% to 26.7%), although women had more individual variations. On average, people without disease or who were physically active displayed better physical capacity than people with disease or who were physically passive.

Low intrinsic exercise capacity in rats predisposes to age-dependent cardiac remodeling independent of macrovascular function

PubMed Central

Ritchie, Rebecca H.; Leo, Chen Huei; Qin, Chengxue; Stephenson, Erin J.; Bowden, Marissa A.; Buxton, Keith D.; Lessard, Sarah J.; Rivas, Donato A.; Koch, Lauren G.; Britton, Steven L.; Woodman, Owen L.

2013-01-01

Rats selectively bred for low (LCR) or high (HCR) intrinsic running capacity simultaneously present with contrasting risk factors for cardiovascular and metabolic disease. However, the impact of these phenotypes on left ventricular (LV) morphology and microvascular function, and their progression with aging, remains unresolved. We tested the hypothesis that the LCR phenotype induces progressive age-dependent LV remodeling and impairments in microvascular function, glucose utilization, and β-adrenergic responsiveness, compared with HCR. Hearts and vessels isolated from female LCR (n = 22) or HCR (n = 26) were studied at 12 and 35 wk. Nonselected N:NIH founder rats (11 wk) were also investigated (n = 12). LCR had impaired glucose tolerance and elevated plasma insulin (but not glucose) and body-mass at 12 wk compared with HCR, with early LV remodeling. By 35 wk, LV prohypertrophic and glucose transporter GLUT4 gene expression were up- and downregulated, respectively. No differences in LV β-adrenoceptor expression or cAMP content between phenotypes were observed. Macrovascular endothelial function was predominantly nitric oxide (NO)-mediated in both phenotypes and remained intact in LCR for both age-groups. In contrast, mesenteric arteries microvascular endothelial function, which was impaired in LCR rats regardless of age. At 35 wk, endothelial-derived hyperpolarizing factor-mediated relaxation was impaired whereas the NO contribution to relaxation is intact. Furthermore, there was reduced β2-adrenoceptor responsiveness in both aorta and mesenteric LCR arteries. In conclusion, diminished intrinsic exercise capacity impairs systemic glucose tolerance and is accompanied by progressive development of LV remodeling. Impaired microvascular perfusion is a likely contributing factor to the cardiac phenotype. PMID:23262135

Immunity against influenza A(H1N1) infections is determined by age at the time of initial strain circulation.

PubMed

Delabre, R M; Salez, N; Lapidus, N; Lemaitre, M; Leruez-Ville, M; de Lamballerie, X; Carrat, F

2017-01-01

We explored age-dependent patterns in haemagglutination inhibition (HI) titre to seasonal [1956 A(H1N1), 1977 A(H1N1), 2007 A(H1N1)] and pandemic [A(H1N1)pdm09] influenza strains using serological data collected from an adult French influenza cohort. Subjects were recruited by their general practitioners from 2008 to 2009 and followed until 2010. We explored age-related differences between strain-specific HI titres using 1053 serological samples collected over the study period from 398 unvaccinated subjects. HI titres against the tested seasonal and pandemic strains were determined using the HI technique. Geometric mean titres (GMTs) were estimated using regression models for interval-censored data. Generalized additive mixed models were fit to log-transformed HI estimates to study the relationship between HI titre and age (age at inclusion and/or age at initial strain circulation). GMT against one strain was consistently highest in the birth cohort exposed to that strain during childhood, with peak titres observed in subjects aged 7-8 years at the time of initial strain circulation. Our results complete previous findings on influenza A(H3N2) strains and identify a strain-dependent relationship between HI titre and age at initial strain circulation.

The relation of maternal job strain and cortisol levels during early pregnancy with body composition later in the 5-year-old child: the ABCD study.

PubMed

Van Dijk, Aimée E; Van Eijsden, Manon; Stronks, Karien; Gemke, Reinoud J B J; Vrijkotte, Tanja G M

2012-06-01

Prenatal exposure to maternal stress may program the fetal HPA axis, potentially leading to altered metabolism in later life, associated with adiposity and diabetes. This association is little studied in humans, and thus we explore whether high maternal job strain during early pregnancy, as well as maternal cortisol levels are associated with increased body mass index (BMI), central adiposity or body fat mass in the offspring at age five. Additionally, we explore whether these associations are modified by gender or mediated by gestational age and fetal growth restriction. 2939 pregnant women (ABCD cohort study) completed a questionnaire around gestational week 16 including the Job Content Questionnaire, assessing job strain. Serum total cortisol was assessed in a subsample (n=1320). Gestational age (≥37 weeks), standardized birth weight and information on many covariates were available. At the age five health check, height, weight (BMI, kg/m(2)), waist circumference (waist-to-height ratio, WHtR) and Fat Mass Index (FMI, kg/m(2)) were assessed. Job strain was not associated with higher BMI, WHtR or FMI. Higher maternal cortisol was independently associated with marginally higher FMI in girls, but marginally lower FMI in boys (β 0.09 and β -0.10 per 100 unit increase in serum cortisol, respectively. p<0.01). This association was not mediated by gestational age or fetal growth restriction. Results show that prenatal maternal job strain and cortisol may not program obesity and adiposity in the next generation in humans, but gender differences should always be considered. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Expression of glucocorticoid receptor and early growth response gene 1 during postnatal development of two inbred strains of mice exposed to early life stress.

PubMed

Navailles, Sylvia; Zimnisky, Ross; Schmauss, Claudia

2010-07-01

Early life stress can elicit profound changes in adult gene expression and behavior. One consequence of early life stress is a decreased expression of glucocorticoid receptors (GRs) in the frontal cortex and hippocampus. However, neither the time of onset nor the mechanism(s) leading to decreased GR expression during postnatal development are known. The present study used two inbred strains of mice that differ in their behavioral responsiveness to stress (Balb/c and C57Bl/6), exposed them to an established paradigm of early life stress (infant maternal separation), and measured their expression of frontal cortical and hippocampal GRs and the putative transcriptional activator of the GR gene, early growth response gene (egr)-1, at defined stages of postnatal development. In both strains, real-time RT-PCR experiments revealed that decreased expression of GR in adolescence and adulthood is, in fact, preceded by increased GR expression during early life stress exposure. Thus, the early life stress-induced disruption of the normal stress-hyporesponsive period during infancy is accompanied by increased GR expression. Moreover, chronic treatment with the antidepressant drug fluoxetine during adolescence or adulthood reversed the effect of early life stress on adult GR mRNA expression. In contrast to the strain-independent effect of early life stress on GR expression, however, changes in egr-1 expression occurred only in Balb/c mice, and unlike the biphasic developmental changes in GR mRNA expression, egr-1 mRNA was decreased throughout postnatal development. Moreover, there was no consistent overlap of anatomic regions affected by decreased GR and egr-1 protein expression. Thus, in Balb/c mice, changes in GR and egr-1 expression can independently contribute to the phenotypes resulting from early life stress exposure. These findings illustrate that the impact of early life stress on gene expression changes is modulated by the genetic background and that the persistent

An Old Problem: Aging and Skeletal-Muscle-Strain Injury.

PubMed

Baker, Brent A

2017-04-01

Clinical Scenario: Even though chronological aging is an inevitable phenomenological consequence occurring in every living organism, it is biological aging that may be the most significant factor challenging our quality of life. Development of functional limitations, resulting from improper maintenance and restoration of various organ systems, ultimately leads to reduced health and independence. Skeletal muscle is an organ system that, when challenged, is often injured in response to varying stimuli. Overt muscle-strain injury can be traumatic, clinically diagnosable, properly managed, and a remarkably common event, yet our contemporary understanding of how age and environmental stressors affect the initial and subsequent induction of injury and how the biological processes resulting from this event are modifiable and, eventually, lead to functional restoration and healing of skeletal muscle and adjacent tissues is presently unclear. Even though the secondary injury response to and recovery from "contraction-induced" skeletal-muscle injury are impaired with aging, there is no scientific consensus as to the exact mechanism responsible for this event. Given the multitude of investigative approaches, particular consideration given to the appropriateness of the muscle-injury model, or research paradigm, is critical so that outcomes may be physiologically relevant and translational. In this case, methods implementing stretch-shortening contractions, the most common form of muscle movements used by all mammals during physical movement, work, and activity, are highlighted. Understanding the fundamental evidence regarding how aging influences the responsivity of skeletal muscle to strain injury is vital for informing how clinicians approach and implement preventive strategies, as well as therapeutic interventions. From a practical perspective, maintaining or improving the overall health and tissue quality of skeletal muscle as one ages will positively affect skeletal

Spiroplasma infection causes either early or late male killing in Drosophila, depending on maternal host age

NASA Astrophysics Data System (ADS)

Kageyama, Daisuke; Anbutsu, Hisashi; Shimada, Masakazu; Fukatsu, Takema

2007-04-01

Symbiont-induced male-killing phenotypes have been found in a variety of insects. Conventionally, these phenotypes have been divided into two categories according to the timing of action: early male killing at embryonic stages and late male killing at late larval stages. In Drosophila species, endosymbiotic bacteria of the genus Spiroplasma have been known to cause early male killing. Here, we report that a spiroplasma strain normally causing early male killing also induces late male killing depending on the maternal host age: male-specific mortality of larvae and pupae was more frequently observed in the offspring of young females. As the lowest spiroplasma density and occasional male production were also associated with newly emerged females, we proposed the density-dependent hypothesis for the expression of early and late male-killing phenotypes. Our finding suggested that (1) early and late male-killing phenotypes can be caused by the same symbiont and probably by the same mechanism; (2) late male killing may occur as an attenuated expression of early male killing; (3) expression of early and late male-killing phenotypes may be dependent on the symbiont density, and thus, could potentially be affected by the host immunity and regulation; and (4) early male killing and late male killing could be alternative strategies adopted by microbial reproductive manipulators.

Investigation of Strain Aging in the Ordered Intermetallic Compound beta-NiAl. Ph.D. Thesis Final Contractor Report

NASA Technical Reports Server (NTRS)

Weaver, Mark Lovell

1995-01-01

The phenomenon of strain aging has been investigated in polycrystalline and single crystal NiAl alloys at temperatures between 300 and 1200 K. Static strain aging studies revealed that after annealing at 1100 K for 7200 s (i.e., 2h) followed by furnace cooling, high purity, nitrogen-doped and titanium-doped polycrystalline alloys exhibited continuous yielding, while conventional-purity and carbon-doped alloys exhibited distinct yield points and Luders strains. Prestraining by hydrostatic pressurization removed the yield points, but they could be reintroduced by further annealing treatments. Yield points could be reintroduced more rapidly if the specimens were prestrained uniaxially rather than hydrostatically, owing to the arrangement of dislocations into cell structures during uniaxial deformation. The time dependence of the strain aging events followed at t(exp 2/3) relationship suggesting that the yield points observed in polycrystalline NiAl were the result of the pinning of mobile dislocations by interstitials, specifically carbon. Between 700 and 800 K, yield stress plateaus, yield stress transients upon a ten-fold increase in strain rate, work hardening peaks, and dips in the strain rate sensitivity (SRS) have been observed in conventional-purity and carbon-doped polycrystals. In single crystals, similar behavior was observed; in conventional-purity single crystals, however, the strain rate sensitivity became negative resulting in serrated yielding, whereas, the strain rate sensitivity stayed positive in high purity and in molybdenum-doped NiAl. These observations are indicative of dynamic strain aging (DSA) and are discussed in terms of conventional strain aging theories. The impact of these phenomena on the composition-structure-property relations are discerned. Finally, a good correlation has been demonstrated between the properties of NiAl alloys and a recently developed model for strain aging in metals and alloys developed by Reed-Hill et al.

[Age-specific dynamics of mental working capacity in different regimens of locomotor activity].

PubMed

Miakotnykh, V V; Khodasevich, L S

2012-01-01

The present study included a total of 392 practically healthy men aged between 40 and 79 years differing in the character of routine locomotor activity and the training status (from masters of sport of international grade to the subjects who had never been engaged in sporting activities). They were divided into 4 groups each comprised of subjects ranged by age with a ten-year interval. Their mental working capacity was estimated from the results of the correction test. The study demonstrated that the subjects characterized by a high level of day-to-day locomotor activity have higher indices of attention intensity and information processing speed compared with the age-matched ones leading a relatively sedentary lifestyle. Moreover, they have better chances to retain the mental working capacity up to the age of 70 years.

n-Alkane assimilation and tert-butyl alcohol (TBA) oxidation capacity in Mycobacterium austroafricanum strains.

PubMed

Lopes Ferreira, Nicolas; Mathis, Hugues; Labbé, Diane; Monot, Frédéric; Greer, Charles W; Fayolle-Guichard, Françoise

2007-06-01

Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C2 to C16). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C1 to C16) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during MTBE metabolism.

Salivary pH and Buffering Capacity as Risk Markers for Early Childhood Caries: A Clinical Study.

PubMed

Jayaraj, D; Ganesan, S

2015-01-01

The diagnostic utility of saliva is currently being explored in various branches of dentistry, remarkably in the field of caries research. This study was aimed to determine if assessment of salivary pH and buffering capacity would serve as reliable tools in risk prediction of early childhood caries (ECC). Paraffin-stimulated salivary samples were collected from 50 children with ECC (group I) and 50 caries free children (group II). Salivary pH and buffering capacity (by titration with 0.1 N hydrochloric acid) were assessed using a handheld digital pH meter in both groups. The data obtained were subjected to statistical analysis. Statistically, no significant difference was observed between both the groups for all salivary parameters assessed, except for the buffering capacity level at 150 μl titration of 0.1 N hydrochloric acid (p = 0.73; significant at 1% level). Salivary pH and buffering capacity may not serve as reliable markers for risk prediction of ECC. How to cite this article: Jayaraj D, Ganesan S. Salivary pH and Buffering Capacity as Risk Markers for Early Childhood Caries: A Clinical Study. Int J Clin Pediatr Dent 2015;8(3):167-171.

Enhancement of learning capacity and cholinergic synaptic function by carnitine in aging rats.

PubMed

Ando, S; Tadenuma, T; Tanaka, Y; Fukui, F; Kobayashi, S; Ohashi, Y; Kawabata, T

2001-10-15

The effects of a carnitine derivative, acetyl-L-carnitine (ALCAR), on the cognitive and cholinergic activities of aging rats were examined. Rats were given ALCAR (100 mg/kg) per os for 3 months and were subjected to the Hebb-Williams tasks and a new maze task, AKON-1, to assess their learning capacity. The learning capacity of the ALCAR-treated group was superior to that of the control. Cholinergic activities were determined with synaptosomes isolated from the cortices. The high-affinity choline uptake by synaptosomes, acetylcholine synthesis in synaptosomes, and acetylcholine release from synaptosomes on membrane depolarization were all enhanced in the ALCAR group. This study indicates that chronic administration of ALCAR increases cholinergic synaptic transmission and consequently enhances learning capacity as a cognitive function in aging rats. Copyright 2001 Wiley-Liss, Inc.

Early Executive Function at Age Two Predicts Emergent Mathematics and Literacy at Age Five

PubMed Central

Mulder, Hanna; Verhagen, Josje; Van der Ven, Sanne H. G.; Slot, Pauline L.; Leseman, Paul P. M.

2017-01-01

Previous work has shown that individual differences in executive function (EF) are predictive of academic skills in preschoolers, kindergartners, and older children. Across studies, EF is a stronger predictor of emergent mathematics than literacy. However, research on EF in children below age three is scarce, and it is currently unknown whether EF, as assessed in toddlerhood, predicts emergent academic skills a few years later. This longitudinal study investigates whether early EF, assessed at two years, predicts (emergent) academic skills, at five years. It examines, furthermore, whether early EF is a significantly stronger predictor of emergent mathematics than of emergent literacy, as has been found in previous work on older children. A sample of 552 children was assessed on various EF and EF-precursor tasks at two years. At age five, these children performed several emergent mathematics and literacy tasks. Structural Equation Modeling was used to investigate the relationships between early EF and academic skills, modeled as latent factors. Results showed that early EF at age two was a significant and relatively strong predictor of both emergent mathematics and literacy at age five, after controlling for receptive vocabulary, parental education, and home language. Predictive relations were significantly stronger for mathematics than literacy, but only when a verbal short-term memory measure was left out as an indicator to the latent early EF construct. These findings show that individual differences in emergent academic skills just prior to entry into the formal education system can be traced back to individual differences in early EF in toddlerhood. In addition, these results highlight the importance of task selection when assessing early EF as a predictor of later outcomes, and call for further studies to elucidate the mechanisms through which individual differences in early EF and precursors to EF come about. PMID:29075209

Early Executive Function at Age Two Predicts Emergent Mathematics and Literacy at Age Five.

PubMed

Mulder, Hanna; Verhagen, Josje; Van der Ven, Sanne H G; Slot, Pauline L; Leseman, Paul P M

2017-01-01

Previous work has shown that individual differences in executive function (EF) are predictive of academic skills in preschoolers, kindergartners, and older children. Across studies, EF is a stronger predictor of emergent mathematics than literacy. However, research on EF in children below age three is scarce, and it is currently unknown whether EF, as assessed in toddlerhood, predicts emergent academic skills a few years later. This longitudinal study investigates whether early EF, assessed at two years, predicts (emergent) academic skills, at five years. It examines, furthermore, whether early EF is a significantly stronger predictor of emergent mathematics than of emergent literacy, as has been found in previous work on older children. A sample of 552 children was assessed on various EF and EF-precursor tasks at two years. At age five, these children performed several emergent mathematics and literacy tasks. Structural Equation Modeling was used to investigate the relationships between early EF and academic skills, modeled as latent factors. Results showed that early EF at age two was a significant and relatively strong predictor of both emergent mathematics and literacy at age five, after controlling for receptive vocabulary, parental education, and home language. Predictive relations were significantly stronger for mathematics than literacy, but only when a verbal short-term memory measure was left out as an indicator to the latent early EF construct. These findings show that individual differences in emergent academic skills just prior to entry into the formal education system can be traced back to individual differences in early EF in toddlerhood. In addition, these results highlight the importance of task selection when assessing early EF as a predictor of later outcomes, and call for further studies to elucidate the mechanisms through which individual differences in early EF and precursors to EF come about.

Comparative evaluation and correlation of salivary total antioxidant capacity and salivary pH in caries-free and severe early childhood caries children.

PubMed

Muchandi, Sneha; Walimbe, Hrishikesh; Bijle, Mohammed Nadeem Ahmed; Nankar, Meenakshi; Chaturvedi, Srishti; Karekar, Priyanka

2015-03-01

Dental caries is a major problem in preschool children. The contribution of saliva in providing defense during caries process is of primary importance. pH buffer capacity through bicarbonate, phosphate and protein buffer systems have universal acceptance as a caries defense mechanism. Antioxidant capacity of saliva can constitute a first line of defense against chronic degenerative diseases including dental caries. Till date, no study is presented with salivary antioxidant capacity of younger children affected with severe early childhood caries with its salivary pH correlation. Hence, this study was carried out to compare, evaluate and correlate the salivary total antioxidant capacity (TAC) and salivary pH of children with caries-free and severe early childhood caries. Fifty children from ages 3 to 5 years divided into two study groups had undergone screening. Group I (n = 25) with severe early childhood caries (S-ECC) and group II (n = 25) who were caries free. Unstimulated whole saliva of subjects were in the collection during the study by draining method. Salivary pH determination of saliva samples was done using pH indicator paper strips. The TAC was done using an antioxidant assay with the help of a spectrophotometer at wavelength 532 nm. The means of salivary pH and TAC were subjected to analysis using unpaired student 't' test and correlation was determined using Pearsons correlation coefficient analysis. Mean salivary pH was higher in group II (7.46 ± 0.37). Mean TAC was greater in group I (1.82 ± 0.19). A statistically significant negative correlation as seen between TAC and salivary pH in S-ECC patients. The study concludes that salivary TAC increases in patients with S-ECC are by that showing a high indirect relationship with salivary pH.

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…

Thermomechanical coupling and dynamic strain ageing in ductile fracture

NASA Astrophysics Data System (ADS)

Delafosse, David

1995-01-01

This work is concerned with plastic deformation at the tip of a ductile tearing crack during propagation. Two kinds of effects are investigated: the thermomechanical coupling at the tip of a mobile ductile crack, and the influence of Dynamic Strain Aging (DSA) on ductile fracture. Three alloys are studied: a nickel based superalloy (N18), a soft carbon steel, and an Al-Li light alloy (2091). The experimental study of the thermo mechanical coupling effects by means of infrared thermography stresses the importance of plastic dissipation in the energy balance of ductile fracture. Numerical simulations involving plastic deformation as the only dissipation mechanism account for the main part of the measured heating. The effects of DSA on ductile tearing are investigated in the 2091 Al-Li alloy. Based on the strain rate/temperature dependence predicted by the standard model of DSA, an experimental procedure is set up for this purpose. Three main effects are evidenced. A maximum in tearing resistance is shown to be associated with the minimum of strain rate sensitivity. Through a simple model, this peak in tearing resistance is attributed to an increase in plastic dissipation as the strain rate sensitivity is decreased. Heterogenous plastic deformation is observed in the crack tip plastic zone. Comparison with uniaxial testing allows us to identify the observed strain heterogeneities as Portevin-Le Chatelier instabilities in the crack tip plastic zone. We perform a simplified numerical analysis of the effect of strain localization on crack tip screening. Finally, small crack propagation instabilities appear at temperatures slightly above that of the tearing resistance peak. These are interpreted as resulting from a positive feed-back between the local heating at the tip of a moving crack and the decrease in tearing resistance with increasing temperature.

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…

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…

Sex-Specific and Strain-Dependent Effects of Early Life Adversity on Behavioral and Epigenetic Outcomes

PubMed Central

Kundakovic, Marija; Lim, Sean; Gudsnuk, Kathryn; Champagne, Frances A.

2013-01-01

Early life adversity can have a significant long-term impact with implications for the emergence of psychopathology. Disruption to mother-infant interactions is a form of early life adversity that may, in particular, have profound programing effects on the developing brain. However, despite converging evidence from human and animal studies, the precise mechanistic pathways underlying adversity-associated neurobehavioral changes have yet to be elucidated. One approach to the study of mechanism is exploration of epigenetic changes associated with early life experience. In the current study, we examined the effects of postnatal maternal separation (MS) in mice and assessed the behavioral, brain gene expression, and epigenetic effects of this manipulation in offspring. Importantly, we included two different mouse strains (C57BL/6J and Balb/cJ) and both male and female offspring to determine strain- and/or sex-associated differential response to MS. We found both strain-specific and sex-dependent effects of MS in early adolescent offspring on measures of open-field exploration, sucrose preference, and social behavior. Analyses of cortical and hippocampal mRNA levels of the glucocorticoid receptor (Nr3c1) and brain-derived neurotrophic factor (Bdnf) genes revealed decreased hippocampal Bdnf expression in maternally separated C57BL/6J females and increased cortical Bdnf expression in maternally separated male and female Balb/cJ offspring. Analyses of Nr3c1and Bdnf (IV and IX) CpG methylation indicated increased hippocampal Nr3c1 methylation in maternally separated C57BL/6J males and increased hippocampal Bdnf IX methylation in male and female maternally separated Balb/c mice. Overall, though effect sizes were modest, these findings suggest a complex interaction between early life adversity, genetic background, and sex in the determination of neurobehavioral and epigenetic outcomes that may account for differential vulnerability to later-life disorder. PMID:23914177

FACTORS INFLUENCING AGE AND STRAIN-RELATED SUSCEPTIBILITY TO 3-METHYLCHOLANTHRENE CARCINOGENICITY

EPA Science Inventory

Fetal mice are more sensitive to chemical carcinogens than are adults. Further, some strains of mice are more susceptible to chemical carcinogens than others. We have been conducting studies to understand the interactions between age and genetic background underlying these suscep...

Early metformin therapy (age 8-12 years) in girls with precocious pubarche to reduce hirsutism, androgen excess, and oligomenorrhea in adolescence.

PubMed

Ibáñez, Lourdes; López-Bermejo, Abel; Díaz, Marta; Marcos, Maria Victoria; de Zegher, Francis

2011-08-01

Girls with a combined history of low(-normal) birth weight (LBW) and precocious pubarche (PP) are at high risk to develop polycystic ovary syndrome (PCOS). The objective of the study was to compare the capacity of early vs. late metformin treatment to prevent adolescent PCOS. This was a randomized, open-label study over 7 yr. The study was conducted at a university hospital. Thirty-eight LBW-PP girls were followed up from the mean age 8 until age 15 yr. Early metformin (study yr 1-4; age 8-12 yr) vs. late metformin (yr 6; age 13-14 yr). Measures included height; weight; hirsutism score; menstrual cycle; endocrine-metabolic screening (fasting; follicular phase); C-reactive protein; body composition (absorptiometry); abdominal fat partitioning (magnetic resonance imaging); ovarian morphology (ultrasound); PCOS (National Institutes of Health and Androgen Excess Society definitions) after yr 7 (all girls thus untreated for at least 1 yr). None of the girls dropped out of the study. At age 15 yr, early-metformin girls were taller (4 cm), were in a less proinflammatory state, and had less central fat due to reductions in visceral and hepatic fat. Hirsutism, androgen excess, oligomenorrhea, and PCOS were between 2- and 8-fold more prevalent in late- than early-treated girls. Abdominal adiposity was the first variable to diverge (at age 8-10 yr) between girls without vs. with PCOS at age 15 yr. In LBW-PP girls, early metformin therapy was found to prevent or delay the development of hirsutism, androgen excess, oligomenorrhea, and PCOS more effectively than late metformin. The time window of late childhood and early puberty may be more critical for the development, and thus for the prevention, of adolescent PCOS than the first years beyond menarche.

Dynamic strain-aging effect on fracture toughness of vessel steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, S.S.; Kim, I.S.

1992-03-01

In this paper the effect of dynamic strain aging (DSA) on fracture is investigated on the quenched and tempered specimens of American Society of Mechanical Engineers (ASME) standard SA508 class 3 nuclear pressure vessel steel. Serrated flow by DSA is observed between 180 and 340{degrees}C at a tensile strain rate of 2.08 {times} 10{sup {minus}4}/s and 1.25 {times} 10{sup {minus}3}/s. The DSA causes a sharp rise in the ultimate tensile strength and a marked decrease in ductility. The DSA range shifts to higher temperatures with increased strain rates. The temperature and strain rate dependence of the onset of serrations yieldsmore » an activation energy of 16.2 kcal/mol, which suggests that the process is controlled by interstitial diffusion of carbon and nitrogen in ferrite. The J{sub i} value obtained from the direct current potential drop (DCPD) method, for true crack initiation, is lowered by DSA. The drop in J{sub i} at elevated temperatures may be because of the interaction of the interstitial impurities with dislocations at the crack front.« less

Spray-drying process preserves the protective capacity of a breast milk-derived Bifidobacterium lactis strain on acute and chronic colitis in mice

PubMed Central

Burns, Patricia; Alard, Jeanne; Hrdỳ, Jiri; Boutillier, Denise; Páez, Roxana; Reinheimer, Jorge; Pot, Bruno; Vinderola, Gabriel; Grangette, Corinne

2017-01-01

Gut microbiota dysbiosis plays a central role in the development and perpetuation of chronic inflammation in inflammatory bowel disease (IBD) and therefore is key target for interventions with high quality and functional probiotics. The local production of stable probiotic formulations at limited cost is considered an advantage as it reduces transportation cost and time, thereby increasing the effective period at the consumer side. In the present study, we compared the anti-inflammatory capacities of the Bifidobacterium animalis subsp. lactis (B. lactis) INL1, a probiotic strain isolated in Argentina from human breast milk, with the commercial strain B. animalis subsp. lactis BB12. The impact of spray-drying, a low-cost alternative of bacterial dehydration, on the functionality of both bifidobacteria was also investigated. We showed for both bacteria that the spray-drying process did not impact on bacterial survival nor on their protective capacities against acute and chronic colitis in mice, opening future perspectives for the use of strain INL1 in populations with IBD. PMID:28233848

Age-related changes in pancreatic elasticity: When should we be concerned about their effect on strain elastography?

PubMed

Chantarojanasiri, Tanyaporn; Hirooka, Yoshiki; Kawashima, Hiroki; Ohno, Eizaburo; Sugimoto, Hiroyuki; Hayashi, Daijuro; Kuwahara, Takamichi; Yamamura, Takeshi; Funasaka, Kohei; Nakamura, Masanao; Miyahara, Ryoji; Ishigami, Masatoshi; Watanabe, Osamu; Hashimoto, Senju; Goto, Hidemi

2016-07-01

Ultrasound strain elastography is one of the useful methods for evaluating pancreatic lesions. During aging, several pancreatic parenchymal changes occur that may interfere with the interpretation of the ultrasound images. We studied age-related changes in pancreatic elasticity using transabdominal ultrasound strain elastography in subjects without known pancreatic disease. This study was conducted at Nagoya University Hospital, which is an academic medical center, and included 102 subjects (66 women and 39 men) aged 20-85years (mean 58.6±17.5) who underwent transabdominal ultrasonography for screening and follow-up for non-pancreatic diseases. Strain elastography of the pancreas was performed, and the results were subjected to quantitative strain histogram analysis. The correlations of age with four elastographic parameters (Mean, Standard deviation, Skewness, and Kurtosis) and other findings, including hyperechoic pancreas, hyperechoic liver, and diabetes, were evaluated. There was a significant correlation between increasing age and elastographic parameters such as the Mean (P=0.004), Skewness (P=0.007), and Kurtosis (P=0.03), and these differences became significant after the age of 40. The prevalence of hyperechoic pancreas increased with age (P<0.001), and the Means were lower in those with hyperechoic pancreas (P=0.004) and a higher body mass index (BMI, P=0.008). No significant correlations with diabetes, hyperechoic liver, or elastographic parameters were demonstrated. Strain elastography demonstrated elastographic changes in the pancreas with aging that included a decreasing Mean and increasing Skewness and Kurtosis after the age of 40. The prevalence of pancreatic hyperechogenicity increased, and the pancreatic hyperechogenicity was significantly negatively correlated with the Mean. Copyright © 2016 Elsevier B.V. All rights reserved.

Local strain-induced band gap fluctuations and exciton localization in aged WS2 monolayers

NASA Astrophysics Data System (ADS)

Krustok, J.; Kaupmees, R.; Jaaniso, R.; Kiisk, V.; Sildos, I.; Li, B.; Gong, Y.

2017-06-01

Optical properties of aged WS2 monolayers grown by CVD method on Si/SiO2 substrates are studied using temperature dependent photoluminescence and reflectance contrast spectroscopy. Aged WS2 monolayers have a typical surface roughness about 0.5 nm and, in addition, a high density of nanoparticles (nanocaps) with the base diameter about 30 nm and average height of 7 nm. The A-exciton of aged monolayer has a peak position at 1.951 eV while in as-grown monolayer the peak is at about 24 meV higher energy at room temperature. This red-shift is explained using local tensile strain concept, where strain value of 2.1% was calculated for these nanocap regions. Strained nanocaps have lower band gap energy and excitons will funnel into these regions. At T=10K a double exciton and trion peaks were revealed. The separation between double peaks is about 20 meV and the origin of higher energy peaks is related to the optical band gap energy fluctuations caused by random distribution of local tensile strain due to increased surface roughness. In addition, a wide defect related exciton band XD was found at about 1.93 eV in all aged monolayers. It is shown that the theory of localized excitons describes well the temperature dependence of peak position and halfwidth of the A-exciton band. The possible origin of nanocaps is also discussed.

Evolution behavior of nanohardness after thermal-aging and hydrogen-charging on austenite and strain-induced martensite in pre-strained austenitic stainless steel

NASA Astrophysics Data System (ADS)

Zheng, Yuanyuan; Zhou, Chengshuang; Hong, Yuanjian; Zheng, Jinyang; Zhang, Lin

2018-05-01

Nanoindentation has been used to study the effects of thermal-aging and hydrogen on the mechanical property of the metastable austenitic stainless steel. Thermal-aging at 473 K decreases the nanohardness of austenite, while it increases the nanohardness of strain-induced ɑ‧ martensite. Hydrogen-charging at 473 K increases the nanohardness of austenite, while it decreases the nanohardness of strain-induced ɑ‧ martensite. The opposite effect on austenite and ɑ‧ martensite is first found in the same pre-strained sample. This abnormal evolution behavior of hardness can be attributed to the interaction between dislocation and solute atoms (carbon and hydrogen). Carbon atoms are difficult to move and redistribute in austenite compared with ɑ‧ martensite. Therefore, the difference in the diffusivity of solute atoms between austenite and ɑ‧ martensite may result in the change of hardness.

Early auditory evoked potential is modulated by selective attention and related to individual differences in visual working memory capacity.

PubMed

Giuliano, Ryan J; Karns, Christina M; Neville, Helen J; Hillyard, Steven A

2014-12-01

A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual's capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70-90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals.

High capacity lithium ion batteries composed of cobalt oxide nanoparticle anodes and Raman spectroscopic analysis of nanoparticle strain dynamics in batteries

NASA Astrophysics Data System (ADS)

Islam, Mohammad A.; Zuba, Mateusz; DeBiase, Vincent; Noviasky, Nicholas; Hawley, Christopher J.

2018-02-01

Cobalt nanoparticle thin films were electrophoretically deposited on copper current collectors and were annealed into thin films of hollow Co3O4 nanoparticles. These thin films were directly used as the anodes of lithium ion batteries (LIBs) without the addition of conducting carbons and bonding agents. LIBs thus fabricated show high gravimetric capacities and long cycle lives. For ≈1.0 μm thick Co3O4 nanoparticle films the gravimetric capacities of the batteries were more than 800 mAh g-1 at a current rate of C/15, which is about 90% of the theoretical maximum. Additionally, the batteries were able to undergo 200 charge/discharge cycles at a relatively fast rate of C/5 and maintain 50% of the initial capacity. In order to understand the electrochemistry of lithiation in the context of nanoparticles, Raman spectra were collected at different stages of the electrode cycles to determine the chemical and structural changes in the nanomaterials. Our results indicate that initially the electrode nanoparticles were under significant strain and as the battery underwent many cycles of charging/discharging the nanoparticles experienced progressive strain relaxation.

Effects of Sex, Strain, and Energy Intake on Hallmarks of Aging in Mice.

PubMed

Mitchell, Sarah J; Madrigal-Matute, Julio; Scheibye-Knudsen, Morten; Fang, Evandro; Aon, Miguel; González-Reyes, José A; Cortassa, Sonia; Kaushik, Susmita; Gonzalez-Freire, Marta; Patel, Bindi; Wahl, Devin; Ali, Ahmed; Calvo-Rubio, Miguel; Burón, María I; Guiterrez, Vincent; Ward, Theresa M; Palacios, Hector H; Cai, Huan; Frederick, David W; Hine, Christopher; Broeskamp, Filomena; Habering, Lukas; Dawson, John; Beasley, T Mark; Wan, Junxiang; Ikeno, Yuji; Hubbard, Gene; Becker, Kevin G; Zhang, Yongqing; Bohr, Vilhelm A; Longo, Dan L; Navas, Placido; Ferrucci, Luigi; Sinclair, David A; Cohen, Pinchas; Egan, Josephine M; Mitchell, James R; Baur, Joseph A; Allison, David B; Anson, R Michael; Villalba, José M; Madeo, Frank; Cuervo, Ana Maria; Pearson, Kevin J; Ingram, Donald K; Bernier, Michel; de Cabo, Rafael

2016-06-14

Calorie restriction (CR) is the most robust non-genetic intervention to delay aging. However, there are a number of emerging experimental variables that alter CR responses. We investigated the role of sex, strain, and level of CR on health and survival in mice. CR did not always correlate with lifespan extension, although it consistently improved health across strains and sexes. Transcriptional and metabolomics changes driven by CR in liver indicated anaplerotic filling of the Krebs cycle together with fatty acid fueling of mitochondria. CR prevented age-associated decline in the liver proteostasis network while increasing mitochondrial number, preserving mitochondrial ultrastructure and function with age. Abrogation of mitochondrial function negated life-prolonging effects of CR in yeast and worms. Our data illustrate the complexity of CR in the context of aging, with a clear separation of outcomes related to health and survival, highlighting complexities of translation of CR into human interventions. Published by Elsevier Inc.

Reduced vital capacity after methacholine challenge in early childhood--is it due to trapped air or loss of motivation.

PubMed

Vilozni, Daphna; Hakim, Fahed; Adler, Adi; Livnat, Galit; Bar-Yishay, Ephraim; Bentur, Lea

2009-01-01

In a previous study we assessed the feasibility of measuring bronchial-reactivity (BHR) in young asthmatic children by the determination of PC(20)-FEV(1) along with clinical end-of-test criteria during a methacholine challenge test (MCT). The end-point was associated with a significant reduction in both flow and vital capacity values. The findings could be due to the children's loss of motivation, which may preclude use of this test. Alternatively, if it reflects air trapping during airway obstruction, it might reinforce its applicability in preschool age children. To elucidate the mechanism of low vital capacity at PC(20)-FEV(1) in preschool age children. Twenty-eight children (3.3-6.9 years) with recurrent respiratory symptoms. An MCT was carried out using tripling doses (0.06-13.9 mg/ml) delivered by a dosimeter. Spirometry was measured at baseline and after each inhalation in duplicate sets. Whole body plethysmography was measured at baseline and at end-of-test (defined by clinical criteria) according to the recommendations for older populations. Plethysmography was reliably performed by 20 children before and after MCT. At baseline, lung function was within the healthy range. At end-of-test (PC(20)-FEV(1)=4.02+/-3.47 mg/ml), the spirometry parameters and specific conductance values were markedly reduced in correlation with a significant increase in residual volume and resistance. The study shows that diminished vital capacity is due to the increase in FRC at end-of-test. Our findings support the use of PC(20)-FEV(1) during BHR in young children and suggest that lung volume measurement by a plethysmograph may be feasible in early childhood. Larger studies should be performed to establish the clinical applicability of PC20-FEV1 determination in the preschool age.

Prediction of Protection against Asian Enterovirus 71 Outbreak Strains by Cross-neutralizing Capacity of Serum from Dutch Donors, The Netherlands

PubMed Central

Koen, Gerrit; van Eijk, Hetty; Koekkoek, Sylvie M.; de Jong, Menno D.; Wolthers, Katja C.

2016-01-01

Outbreaks of human enterovirus 71 (EV-71) in Asia are related to high illness and death rates among children. To gain insight into the potential threat for the population of Europe, we determined the neutralizing activity in intravenous immunoglobulin (IVIg) batches and individual serum samples from donors in the Netherlands against EV-71 strains isolated in Europe and in Asia. All IVIg batches and 41%, 79%, and 65% of serum samples from children ≤5 years of age, women of childbearing age, and HIV-positive men, respectively, showed high neutralizing activity against a Dutch C1 strain, confirming widespread circulation of EV-71 in the Netherlands. Asian B3–4 and C4 strains were efficiently cross-neutralized, predicting possible protection against extensive circulation and associated outbreaks of those types in Europe. However, C2 and C5 strains that had few mutations in the capsid region consistently escaped neutralization, emphasizing the importance of monitoring antigenic diversity among circulating EV-71 strains. PMID:27533024

Key goals and indicators for successful aging of adults with early-onset disability.

PubMed

LaPlante, Mitchell P

2014-01-01

Substantial improvements have occurred in the longevity of several groups of individuals with early-onset disabilities, with many now surviving to advanced ages. This paper estimates the population of adults aging with early-onset disabilities at 12-15 million persons. Key goals for the successful aging of adults with early-onset disabilities are discussed, emphasizing reduction in risks for aging-related chronic disease and secondary conditions, while promoting social participation and independence. However, indicators suggest that elevated risk factors for aging-related chronic diseases, including smoking, obesity, and inactivity, as well as barriers to prevention and the diminished social and economic situation of adults with disabilities are continuing impediments to successful aging that must be addressed. Increased provider awareness that people with early-onset disabilities are aging and can age successfully and the integration of disability and aging services systems are transformative steps that will help adults with early-onset disability to age more successfully. Copyright © 2014 Elsevier Inc. All rights reserved.

Sentence Processing as a Function of Syntax, Short Term Memory Capacity, the Meaningfulness of the Stimulus and Age

ERIC Educational Resources Information Center

Gamlin, Peter J.

1971-01-01

Examines the effects of short term memory (STM) capacity, meaningfulness of stimuli, and age upon listeners' structuring of sentences. Results show that the interaction between STM capacity and meaningfulness (1) approached significance when data were collapsed over both age levels, and (2) was significant for one age level. Tables and references.…

Standard and Strain Measurements by Echocardiography Detect Early Overloaded Right Ventricular Dysfunction: Validation against Hemodynamic and Myocyte Contractility Changes in a Large Animal Model.

PubMed

Hodzic, Amir; Bobin, Pierre; Mika, Delphine; Ly, Mohamed; Lefebvre, Florence; Lechêne, Patrick; Le Bret, Emmanuel; Gouadon, Elodie; Coblence, Mathieu; Vandecasteele, Grégoire; Capderou, André; Leroy, Jérôme; Rucker-Martin, Catherine; Lambert, Virginie

2017-11-01

Early detection of right ventricular (RV) failure is required to improve the management of patients with congenital heart diseases. The aim of this study was to validate echocardiography for the early detection of overloaded RV dysfunction, compared with hemodynamic and myocyte contractility assessment. Using a porcine model reproducing repaired tetralogy of Fallot, RV function was evaluated over 4 months using standard echocardiography and speckle-tracking compared with hemodynamic parameters (conductance catheter). Sarcomere shortening and calcium transients were recorded in RV isolated myocytes. Contractile reserve (ΔE max ) was assessed by β-adrenergic stimulation in vivo (dobutamine 5 μg/kg) and ex vivo (isoproterenol 100 nM). Six operated animals were compared with four age- and sex-matched controls. In the operated group, hemodynamic RV efficient ejection fraction was significantly decreased (29.7% [26.2%-34%] vs 42.9% [40.7%-48.6%], P < .01), and inotropic responses to dobutamine were attenuated (ΔE max was 51% vs 193%, P < .05). Echocardiographic measurements of fraction of area change, tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity (S') and RV free wall longitudinal systolic strain and strain rate were significantly decreased. Strain rate, S', and tricuspid annular plane systolic excursion were correlated with ΔE max (r = 0.75, r = 0.78, and r = 0.65, respectively, P < .05). These alterations were associated in RV isolated myocytes with the decrease of sarcomere shortening in response to isoproterenol and perturbations of calcium homeostasis assessed by the increase of spontaneous calcium waves. In this porcine model, both standard and strain echocardiographic parameters detected early impairments of RV function and cardiac reserve, which were associated with cardiomyocyte excitation-contraction coupling alterations. Copyright © 2017 American Society of Echocardiography. Published by Elsevier

Effect of genetic strain and gender on age-related changes in body composition of the laboratory rat.

PubMed

Gordon, C J; Jarema, K; Johnstone, A F M; Phillips, P M

2016-01-01

Body fat serves as a storage compartment for lipophilic pollutants and affects the pharmacokinetics of many toxic chemicals. Understanding how body fat varies with gender, strain, and age may be essential for development of experimental models to study mechanisms of toxicity. Nuclear magnetic resonance (NMR)-based analysis serves as a noninvasive means of assessing proportions of fat, lean, and fluid in rodents over their lifetime. The aim of this study was to track changes in body composition of male and female Long-Evans (LE), Sprague-Dawley (SD), Fischer (F334), and Brown Norway (BN) rats from postweaning over a >2-yr period. Percent fat of preweaned LE and SD rats was markedly higher compared to the other strains. LE and SD strains displayed marked increases in body fat from weaning to 8 mo of age. Postweaned F344 male and females showed relatively low levels of percent fat; however, at 2 yr of age percent fat of females was equal to that of SD and LE in females. BN rats showed the highest levels of lean tissue and lowest levels of fat. Percent fat of the BN strain rose at the slowest rate as they aged. Percent fluid was consistently higher in males for all strains. Females tended to have higher percent fat than males in LE, SD, and F344 strains. Assessing changes in body fat as well as lean and fluid of various strains of male and female rats over their lifetime may prove useful in many research endeavors, including pharmacokinetics of lipophilic toxicants, mechanisms underlying obesity, and metabolic disorders.

Age and education corrected older adult normative data for a short form version of the Financial Capacity Instrument.

PubMed

Gerstenecker, Adam; Eakin, Amanda; Triebel, Kristen; Martin, Roy; Swenson-Dravis, Dana; Petersen, Ronald C; Marson, Daniel

2016-06-01

Financial capacity is an instrumental activity of daily living (IADL) that comprises multiple abilities and is critical to independence and autonomy in older adults. Because of its cognitive complexity, financial capacity is often the first IADL to show decline in prodromal and clinical Alzheimer's disease and related disorders. Despite its importance, few standardized assessment measures of financial capacity exist and there is little, if any, normative data available to evaluate financial skills in the elderly. The Financial Capacity Instrument-Short Form (FCI-SF) is a brief measure of financial skills designed to evaluate financial skills in older adults with cognitive impairment. In the current study, we present age- and education-adjusted normative data for FCI-SF variables in a sample of 1344 cognitively normal, community-dwelling older adults participating in the Mayo Clinic Study of Aging (MCSA) in Olmsted County, Minnesota. Individual FCI-SF raw scores were first converted to age-corrected scaled scores based on position within a cumulative frequency distribution and then grouped within 4 empirically supported and overlapping age ranges. These age-corrected scaled scores were then converted to age- and education-corrected scaled scores using the same methodology. This study has the potential to substantially enhance financial capacity evaluations of older adults through the introduction of age- and education-corrected normative data for the FCI-SF by allowing clinicians to: (a) compare an individual's performance to that of a sample of similar age and education peers, (b) interpret various aspects of financial capacity relative to a normative sample, and (c) make comparisons between these aspects. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Early-life inflammation, immune response and ageing.

PubMed

Khan, Imroze; Agashe, Deepa; Rolff, Jens

2017-03-15

Age-related diseases are often attributed to immunopathology, which results in self-damage caused by an inappropriate inflammatory response. Immunopathology associated with early-life inflammation also appears to cause faster ageing, although we lack direct experimental evidence for this association. To understand the interactions between ageing, inflammation and immunopathology, we used the mealworm beetle Tenebrio molitor as a study organism. We hypothesized that phenoloxidase, an important immune effector in insect defence, may impose substantial immunopathological costs by causing tissue damage to Malpighian tubules (MTs; functionally equivalent to the human kidney), in turn accelerating ageing. In support of this hypothesis, we found that RNAi knockdown of phenoloxidase (PO) transcripts in young adults possibly reduced inflammation-induced autoreactive tissue damage to MTs, and increased adult lifespan. Our work thus suggests a causative link between immunopathological costs of early-life inflammation and faster ageing. We also reasoned that if natural selection weakens with age, older individuals should display increased immunopathological costs associated with an immune response. Indeed, we found that while old infected individuals cleared infection faster than young individuals, possibly they also displayed exacerbated immunopathological costs (larger decline in MT function) and higher post-infection mortality. RNAi-mediated knockdown of PO response partially rescued MTs function in older beetles and resulted in increased lifespan after infection. Taken together, our data are consistent with a direct role of immunopathological consequences of immune response during ageing in insects. Our work is also the first report that highlights the pervasive role of tissue damage under diverse contexts of ageing and immune response. © 2017 The Author(s).

Early-life inflammation, immune response and ageing

PubMed Central

2017-01-01

Age-related diseases are often attributed to immunopathology, which results in self-damage caused by an inappropriate inflammatory response. Immunopathology associated with early-life inflammation also appears to cause faster ageing, although we lack direct experimental evidence for this association. To understand the interactions between ageing, inflammation and immunopathology, we used the mealworm beetle Tenebrio molitor as a study organism. We hypothesized that phenoloxidase, an important immune effector in insect defence, may impose substantial immunopathological costs by causing tissue damage to Malpighian tubules (MTs; functionally equivalent to the human kidney), in turn accelerating ageing. In support of this hypothesis, we found that RNAi knockdown of phenoloxidase (PO) transcripts in young adults possibly reduced inflammation-induced autoreactive tissue damage to MTs, and increased adult lifespan. Our work thus suggests a causative link between immunopathological costs of early-life inflammation and faster ageing. We also reasoned that if natural selection weakens with age, older individuals should display increased immunopathological costs associated with an immune response. Indeed, we found that while old infected individuals cleared infection faster than young individuals, possibly they also displayed exacerbated immunopathological costs (larger decline in MT function) and higher post-infection mortality. RNAi-mediated knockdown of PO response partially rescued MTs function in older beetles and resulted in increased lifespan after infection. Taken together, our data are consistent with a direct role of immunopathological consequences of immune response during ageing in insects. Our work is also the first report that highlights the pervasive role of tissue damage under diverse contexts of ageing and immune response. PMID:28275145

Early Auditory Evoked Potential Is Modulated by Selective Attention and Related to Individual Differences in Visual Working Memory Capacity

PubMed Central

Giuliano, Ryan J.; Karns, Christina M.; Neville, Helen J.; Hillyard, Steven A.

2015-01-01

A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual’s capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70–90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals. PMID:25000526

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…

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.

A novel and simple cell-based electrochemical biosensor for evaluating the antioxidant capacity of Lactobacillus plantarum strains isolated from Chinese dry-cured ham.

PubMed

Ge, Qingfeng; Ge, Panwei; Jiang, Donglei; Du, Nan; Chen, Jiahui; Yuan, Limin; Yu, Hai; Xu, Xin; Wu, Mangang; Zhang, Wangang; Zhou, Guanghong

2018-01-15

The analysis of antioxidants in foodstuffs has become an active area of research, leading to the recent development of numerous methods for assessing antioxidant capacity. Here we described the fabrication and validation of a novel and simple cell-based electrochemical biosensor for this purpose. The biosensor is used to assess the antioxidant capacity of cell-free extracts from Lactobacillus plantarum strains isolated from Chinese dry-cured ham. The biosensor relies on the determination of cellular reactive oxygen species (ROS) (the flux of H 2 O 2 released from RAW 264.7 macrophage cells) to indirectly assess changes in intracellular oxidative stress level as influenced by L. plantarum strains. A one-step acidified manganese dioxide (a-MnO 2 ) modified gold electrode (GE) was used to immobilize RAW 264.7 macrophage cells, which were then encapsulated in a 3D cell culture system consisting of alginate/ graphene oxide (NaAlg/GO). The biosensor exhibited a rapid and sensitive response for the detection of H 2 O 2 released from RAW264.7 cells. The detection limit was 0.02μM with a linear response from 0.05μM to 0.85μM and the biosensor was shown to have good stability and outstanding repeatability. This technique was then used for evaluating the antioxidant ability of extracts from L. plantarum NJAU-01. According to the electrochemical investigations and assays of SEM, TEM, and ROS, these cell-free extracts effectively reduced the oxidative stress levels in RAW264.7 cells under external stimulation. Extracts from L. plantarum strains at a dose of 10 10 CFU/mL showed the highest antioxidant activities with a relative antioxidant capacity (RAC) rate of 88.94%. Hence, this work provides a simple and efficient electrochemical biosensing platform based on RAW264.7 cells for fast, sensitive and quantitative assessment of antioxidant capacity of L. plantarum strains. The method demonstrates its potential for rapid screening for evaluating antioxidant properties of

Lattice Modeling of Early-Age Behavior of Structural Concrete.

PubMed

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

2017-02-25

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.

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

Experimental evaluation of work capacity as related to chronological and physiological aging.

DOT National Transportation Integrated Search

1963-09-01

Research statistics has establish the fact that physical work capacity declines as a consequence of aging. The question has been raised, however, if this decline is the inevitable result of senescence or merely due to change in living habits. Great n...

Effect of genetic strain and gender on age-related changes in body composition of the laboratory rat.

EPA Pesticide Factsheets

Body composition data for common laboratory strains of rat as a function of age.This dataset is associated with the following publication:Gordon , C., K. Jarema , A. Johnstone , and P. Phillips. Effect of Genetic Strain and Gender on Age-Related Changes in Body Composition of the Laboratory Rat. Physiology & Behavior. Elsevier B.V., Amsterdam, NETHERLANDS, 153(1): 56-63, (2016).

Effects of Age, Hemoglobin Type and Parasite Strain on IgG Recognition of Plasmodium falciparum–Infected Erythrocytes in Malian Children

PubMed Central

Zeituni, Amir E.; Miura, Kazutoyo; Diakite, Mahamadou; Doumbia, Saibou; Moretz, Samuel E.; Diouf, Ababacar; Tullo, Gregory; Lopera-Mesa, Tatiana M.; Bess, Cameron D.; Mita-Mendoza, Neida K.; Anderson, Jennifer M.; Fairhurst, Rick M.; Long, Carole A.

2013-01-01

Background Naturally-acquired antibody responses to antigens on the surface of Plasmodium falciparum-infected red blood cells (iRBCs) have been implicated in antimalarial immunity. To profile the development of this immunity, we have been studying a cohort of Malian children living in an area with intense seasonal malaria transmission. Methodology/Principal Findings We collected plasma from a sub-cohort of 176 Malian children aged 3-11 years, before (May) and after (December) the 2009 transmission season. To measure the effect of hemoglobin (Hb) type on antibody responses, we enrolled age-matched HbAA, HbAS and HbAC children. To quantify antibody recognition of iRBCs, we designed a high-throughput flow cytometry assay to rapidly test numerous plasma samples against multiple parasite strains. We evaluated antibody reactivity of each plasma sample to 3 laboratory-adapted parasite lines (FCR3, D10, PC26) and 4 short-term-cultured parasite isolates (2 Malian and 2 Cambodian). 97% of children recognized ≥1 parasite strain and the proportion of IgG responders increased significantly during the transmission season for most parasite strains. Both strain-specific and strain-transcending IgG responses were detected, and varied by age, Hb type and parasite strain. In addition, the breadth of IgG responses to parasite strains increased with age in HbAA, but not in HbAS or HbAC, children. Conclusions/Significance Our assay detects both strain-specific and strain-transcending IgG responses to iRBCs. The magnitude and breadth of these responses varied not only by age, but also by Hb type and parasite strain used. These findings indicate that studies of acquired humoral immunity should account for Hb type and test large numbers of diverse parasite strains. PMID:24124591

Empirical verification of evolutionary theories of aging.

PubMed

Kyryakov, Pavlo; Gomez-Perez, Alejandra; Glebov, Anastasia; Asbah, Nimara; Bruno, Luigi; Meunier, Carolynne; Iouk, Tatiana; Titorenko, Vladimir I

2016-10-25

We recently selected 3 long-lived mutant strains of Saccharomyces cerevisiae by a lasting exposure to exogenous lithocholic acid. Each mutant strain can maintain the extended chronological lifespan after numerous passages in medium without lithocholic acid. In this study, we used these long-lived yeast mutants for empirical verification of evolutionary theories of aging. We provide evidence that the dominant polygenic trait extending longevity of each of these mutants 1) does not affect such key features of early-life fitness as the exponential growth rate, efficacy of post-exponential growth and fecundity; and 2) enhances such features of early-life fitness as susceptibility to chronic exogenous stresses, and the resistance to apoptotic and liponecrotic forms of programmed cell death. These findings validate evolutionary theories of programmed aging. We also demonstrate that under laboratory conditions that imitate the process of natural selection within an ecosystem, each of these long-lived mutant strains is forced out of the ecosystem by the parental wild-type strain exhibiting shorter lifespan. We therefore concluded that yeast cells have evolved some mechanisms for limiting their lifespan upon reaching a certain chronological age. These mechanisms drive the evolution of yeast longevity towards maintaining a finite yeast chronological lifespan within ecosystems.

Evaluation of the Capacity of PCR and High-Resolution Melt Curve Analysis for Identification of Mixed Infection with Mycoplasma gallisepticum Strains

PubMed Central

Ghorashi, Seyed A.; Kanci, Anna; Noormohammadi, Amir H.

2015-01-01

Pathogenicity and presentation of Mycoplasma gallisepticum (MG) infection may differ from one strain to another and this may have implications on control measures. Infection of individual birds with more than one MG strain has been reported. A PCR followed by high resolution melt (HRM) curve analysis has been developed in our laboratory and routinely used for detection and differentiation of MG strains. However the potential of this test for identification of MG strains in a mixed specimen has not been evaluated. In the present study, the capability of PCR-HRM curve analysis technique, targeting vlhA and pvpA genes was assessed for identification of individual MG strains in a mixed population. Different DNA ratios of two MG strains from 1 to 10-4 ng were tested with some generated conventional and normalized curves distinct from those of individual strains alone. Using genotype confidence percentages (GCP) generated from HRM curve analysis, it was found that vlhA PCR-HRM was more consistent than pvpA PCR-HRM for the detection of MG ts-11 vaccine strain mixed with any of the MG strains 6/85, F, S6 or a field isolate. The potential of vlhA PCR-HRM to detect mixed MG strains in a specimen was found to be primarily dependent on quantity and proportion of the target DNAs in the mixture. This is the first study examining the capacity of PCR-HRM technique for identification of individual MG strains in a mixed strain population. PMID:25970590

Circadian rhythms of body temperature and locomotor activity in aging BALB/c mice: early and late life span predictors.

PubMed

Basso, Andrea; Del Bello, Giovanna; Piacenza, Francesco; Giacconi, Robertina; Costarelli, Laura; Malavolta, Marco

2016-08-01

Impairment of one or more parameters of circadian rhythms (CR) of body temperature (BT) and locomotor activity (LMA) are considered among the hallmarks of mammalian aging. These alterations are frequently used as markers for imminent death in laboratory mice. However, there are still contradictory data for particular strains and it is also uncertain which changes might predict senescence changes later in life, including the force of mortality. In the present paper we use telemetry to study LMA and CR of BT during aging of BALB/c mice. At our knowledge this is the first time that CR of BT and LMA are investigated in this strain in a range of age covering the whole lifespan, from young adult up to very old age. CR of BT was analyzed with a cosine model using a cross sectional approach and follow-up measurements. The results show that BT, LMA, amplitude, goodness-of-fit (GoF) to circadian cycle of temperature decrease with different shapes during chronological age. Moreover, we found that the % change of amplitude and BT in early life (5-19 months) can predict the remaining lifespan of the mice. Later in life (22-32 months), best predictors are single measurements of LMA and GoF. The results of this study also offer potential measures to rapidly identifying freely unrestrained mice with the worst longitudinal outcome and against which existing or novel biomarkers and treatments may be assessed.

Mother-to-Infant Transmission of Intestinal Bifidobacterial Strains Has an Impact on the Early Development of Vaginally Delivered Infant's Microbiota

PubMed Central

Makino, Hiroshi; Kushiro, Akira; Ishikawa, Eiji; Kubota, Hiroyuki; Gawad, Agata; Sakai, Takafumi; Oishi, Kenji; Martin, Rocio; Ben-Amor, Kaouther; Knol, Jan; Tanaka, Ryuichiro

2013-01-01

Objectives Bifidobacterium species are one of the major components of the infant's intestine microbiota. Colonization with bifidobacteria in early infancy is suggested to be important for health in later life. However, information remains limited regarding the source of these microbes. Here, we investigated whether specific strains of bifidobacteria in the maternal intestinal flora are transmitted to their infant's intestine. Materials and Methods Fecal samples were collected from healthy 17 mother and infant pairs (Vaginal delivery: 12; Cesarean section delivery: 5). Mother's feces were collected twice before delivery. Infant's feces were collected at 0 (meconium), 3, 7, 30, 90 days after birth. Bifidobacteria isolated from feces were genotyped by multilocus sequencing typing, and the transitions of bifidobacteria counts in infant's feces were analyzed by quantitative real-time PCR. Results Stains belonging to Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium catenulatum, Bifidobacterium longum subsp. longum, and Bifidobacterium pseudocatenulatum, were identified to be monophyletic between mother's and infant's intestine. Eleven out of 12 vaginal delivered infants carried at least one monophyletic strain. The bifidobacterial counts of the species to which the monophyletic strains belong, increased predominantly in the infant's intestine within 3 days after birth. Among infants delivered by C-section, monophyletic strains were not observed. Moreover, the bifidobacterial counts were significantly lower than the vaginal delivered infants until 7 days of age. Conclusions Among infants born vaginally, several Bifidobacterium strains transmit from the mother and colonize the infant's intestine shortly after birth. Our data suggest that the mother's intestine is an important source for the vaginal delivered infant's intestinal microbiota. PMID:24244304

Dermal Aged and Fetal Fibroblasts Realign in Response to Mechanical Strain

NASA Technical Reports Server (NTRS)

Sawyer, Christine; Grymes, Rose; Alvarez, Teresa (Technical Monitor)

1994-01-01

Integrins specifically recognize and bind extracellular matrix components, providing physical anchor points and functional setpoints. Focal adhesion complexes, containing integrin and cytoskeletal proteins, are potential mechanoreceptors, poised to distribute applied forces through the cytoskeleton. Pursuing the hypothesis that cells both perceive and respond to external force, we applied a stretch/relaxation regimen to normal human fetal and aged dermal fibroblast monolayers cultured on flexible membranes. The frequency and magnitude of the applied force is precisely controlled by the Flexercell Unit(Trademark). A protocol of stretch (20% elongation of the monolayer) at a frequency of 6 cycles/min caused a progressive change from a randomly distributed pattern of cells to a symmetric, radial distribution with cells aligned parallel to the applied force. We have coined the term 'orienteering' as the process of active alignment of cells in response to applied force. Cytochalasin D was added in graded doses to investigate the role of the actin cytoskeleton in force perception and transmission. A clear dose response was found; at high concentrations orienteering was abolished; and the drug's impact was reversible. The two cell strains used were similar in their alignment behavior and in their responses to cytochalasin D. Orienteering was influenced by cell density, and the cell strains studied differed in this respect. Fetal cells, unlike their aged counterparts, failed to orient at high cell density. In both cell strains, mid-density cultures aligned rapidly and sparse cultures lagged. These results indicate that both cell-cell adhesion and cytoskeleton integrity are critical in mediating the orienteering response. Differences between these two cell strains may relate to their expression of extracellular matrix molecules (fibronectin, collagen type 1) integrins and their relative binding affinities.

[Immune system aging rate in patients with early forms of chronic cerebrovascular diseases].

PubMed

Kochetkova, N G; Al'tman, D Sh; Teplova, S N

2009-01-01

Using the Bioage and Snake software the immune and cardiovascular system aging rate was diagnosed in patients having early forms of chronic cerebrovascular diseases (CCVD). The indicators of biological, cardiopulmonary and immunological age were studied in patients showing early symptoms of cerebrovascular insufficiency and dyscirculatory encephalopathy of the 1st stage. The rate of age-dependent physiological changes was diagnosed compared to general body aging rate. Some specific patterns of immune system aging were found in patients with early forms of CCVDs, the cardinal aging symptoms (heterotropia, heterochronia) were verified.

Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains.

PubMed

Nielsen, B L

2012-09-01

Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 26°C), one (HC; 16°C to 26°C) or no (CC; 16°C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

Thermomechanical deformation behavior of a dynamic strain aging alloy, Hastelloy X

NASA Technical Reports Server (NTRS)

Castelli, Michael G.; Miner, Robert V.; Robinson, David N.

1992-01-01

An experimental study was performed to identify the effects of dynamic strain aging (solute drag) and metallurgical instabilities under thermomechanical loading conditions. The study involved a series of closely controlled thermomechanical deformation tests on the solid-solution-strenghened nickel-base superalloy, Hastelloy X. This alloy exhibits a strong isothermal strain aging peak at approximately 600 C, promoted by the effects of solute drag and precipitation hardening. Macroscopic thermomechanical hardening trends are correlated with microstructural characteristics through the use of transmission electron microscopy. These observations are compared and contrasted with isothermal conditions. Thermomechanical behavior unique to the isothermal database is identified and discussed. The microstructural characteristics were shown to be dominated by effects associated with the highest temperature of the thermomechanical cycle. Results indicate that the deformation behavior of Hastelloy X is thermomechanically path dependent. In addition, guidance is given pertaining to deformation modeling in the context of macroscopic unified theory. An internal state variable is formulated to qualitatively reflect the isotropic hardening trends identified in the TMD experiments.

Gratitude From Early Adulthood to Old Age.

PubMed

Allemand, Mathias; Hill, Patrick L

2016-02-01

Are there age differences in gratitude from early adulthood to old age? The current studies tested several ways by which an association between age and dispositional gratitude may present, by considering multiple measures on both fronts. We used data from three cross-sectional studies (total N = 1,736; total age range: 19-94). The results indicated that (a) age effects in gratitude are more likely to occur for subjective age in terms of future time perspective (i.e., people's perceptions of their remaining opportunities and time) than chronological age; (b) chronological age effects are more domain specific than general in nature; and (c) they are more likely to occur for the instrumental domain as compared to the interpersonal domain. Finally, the results indicated that (d) perceived future time, particularly with respect to remaining opportunities, mediates the relation between chronological age and general gratitude. Overall, the findings suggest that gratitude is subject to a variety of developmental influences across adulthood. © 2014 Wiley Periodicals, Inc.

Vital capacity and selected metabolic diseases in middle-aged Japanese men

PubMed Central

Sakuta, Hidenari; Suzuki, Takashi; Yasuda, Hiroko; Ito, Teizo

2006-01-01

OBJECTIVE To elucidate the association between vital capacity and the presence of selected metabolic diseases in middle-aged Japanese men. METHODS A cross-sectional analysis of the associations among forced vital capacity (FVC), static vital capacity as a percentage of that predicted (%VC) and the presence of metabolic diseases was performed. RESULTS In a univariate linear regression analysis, FVC and %VC were inversely associated with poor vegetable intake, cigarette smoking and body mass index, but not with physical activity or ethanol consumption. In a logistic regression analysis adjusted for lifestyle factors, body mass index and age, the odds ratios for the presence of metabolic disease per 0.54 L (1 SD) decrease in FVC were 1.24 (95% CI 1.03 to 1.50) for type II diabetes, 1.21 (95% CI 1.02 to 1.42) for hypertension, 1.34 (95% CI 1.11 to 1.63) for hypertriglyceridemia, 1.23 (95% CI 1.03 to 1.46) for high gamma-glutamyl transferase levels and 1.63 (95% CI 1.10 to 2.41) for an episode of cardiovascular disease. FVC did not correlate with hyperhomocysteinemia, hypercholesterolemia or high white blood cell count. Similar results were also obtained for the association between %VC and metabolic diseases. CONCLUSIONS A decrease in FVC or %VC was associated with the presence of some metabolic diseases. The association may partly explain the reported association between low FVC and cardiovascular disease. PMID:16550264

Exercise capacity and all-cause mortality in male veterans with hypertension aged ≥70 years.

PubMed

Faselis, Charles; Doumas, Michael; Pittaras, Andreas; Narayan, Puneet; Myers, Jonathan; Tsimploulis, Apostolos; Kokkinos, Peter

2014-07-01

Aging, even in otherwise healthy subjects, is associated with declines in muscle mass, strength, and aerobic capacity. Older individuals respond favorably to exercise, suggesting that physical inactivity plays an important role in age-related functional decline. Conversely, physical activity and improved exercise capacity are associated with lower mortality risk in hypertensive individuals. However, the effect of exercise capacity in older hypertensive individuals has not been investigated extensively. A total of 2153 men with hypertension, aged ≥70 years (mean, 75 ± 4) from the Washington, DC, and Palo Alto Veterans Affairs Medical Centers, underwent routine exercise tolerance testing. Peak workload was estimated in metabolic equivalents (METs). Fitness categories were established based on peak METs achieved, adjusted for age: very-low-fit, 2.0 to 4.0 METs (n=386); low-fit, 4.1 to 6.0 METs (n=1058); moderate-fit, 6.1 to 8.0 METs (n=495); high-fit >8.0 METs (n=214). Cox proportional hazard models were applied after adjusting for age, body mass index, race, cardiovascular disease, cardiovascular medications, and risk factors. All-cause mortality was quantified during a mean follow-up period of 9.0 ± 5.5 years. There were a total of 1039 deaths or 51.2 deaths per 1000 person-years of follow-up. Mortality risk was 11% lower (hazard ratio, 0.89; 95% confidence interval, 0.86-0.93; P<0.001) for every 1-MET increase in exercise capacity. When compared with those achieving ≤4.0 METs, mortality risk was 18% lower (hazard ratio, 0.82; 95% confidence interval, 0.70-0.95; P=0.011) for the low-fit, 36% for the moderate-fit (hazard ratio, 0.64; 95% confidence interval, 0.52-0.78; P<0.001), and 48% for the high-fit individuals (hazard ratio, 0.52; 95% confidence interval, 0.39-0.69; P<0.001). These findings suggest that exercise capacity is associated with lower mortality risk in elderly men with hypertension. © 2014 American Heart Association, Inc.

Creating Teacher Capacity in Early Childhood Education and Care Institutions Implementing an Authoritative Adult Style

ERIC Educational Resources Information Center

Omdal, Heidi

2018-01-01

The being together intervention intends to raise teacher capacity in Norwegian Early Childhood Education and Care (ECEC) institutions and promote social and emotional development in preschoolers by implementing an authoritative (warm and predictable) adult style in the institution. An authoritative adult balances between building up high quality…

Cognitive Functioning in Toddlerhood: The Role of Gestational Age, Attention Capacities, and Maternal Stimulation

ERIC Educational Resources Information Center

de Jong, Marjanneke; Verhoeven, Marjolein; Hooge, Ignace T. C.; Maingay-Visser, Arnoldina P. G. F.; Spanjerberg, Louise; van Baar, Anneloes L.

2018-01-01

Why do many preterm children show delays in development? An integrated model of biological risk, children's capacities, and maternal stimulation was investigated in relation to cognitive functioning at toddler age. Participants were 200 Dutch children (gestational age = 32-41 weeks); 51% boys, 96% Dutch nationality, 71.5% highly educated mothers.…

De novo Transcriptome Analysis of Rhizoctonia solani AG1 IA Strain Early Invasion in Zoysia japonica Root.

PubMed

Zhu, Chen; Ai, Lin; Wang, Li; Yin, Pingping; Liu, Chenglan; Li, Shanshan; Zeng, Huiming

2016-01-01

Zoysia japonica brown spot was caused by necrotrophic fungus Rhizoctonia solani invasion, which led to severe financial loss in city lawn and golf ground maintenance. However, little was known about the molecular mechanism of R. solani pathogenicity in Z. japonica. In this study we examined early stage interaction between R. solani AG1 IA strain and Z. japonica cultivar "Zenith" root by cell ultra-structure analysis, pathogenesis-related proteins assay and transcriptome analysis to explore molecular clues for AG1 IA strain pathogenicity in Z. japonica. No obvious cell structure damage was found in infected roots and most pathogenesis-related protein activities showedg a downward trend especially in 36 h post inoculation, which exhibits AG1 IA strain stealthy invasion characteristic. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database classification, most DEGs in infected "Zenith" roots dynamically changed especially in three aspects, signal transduction, gene translation, and protein synthesis. Total 3422 unigenes of "Zenith" root were predicted into 14 kinds of resistance (R) gene class. Potential fungal resistance related unigenes of "Zenith" root were involved in ligin biosynthesis, phytoalexin synthesis, oxidative burst, wax biosynthesis, while two down-regulated unigenes encoding leucine-rich repeat receptor protein kinase and subtilisin-like protease might be important for host-derived signal perception to AG1 IA strain invasion. According to Pathogen Host Interaction (PHI) database annotation, 1508 unigenes of AG1 IA strain were predicted and classified into 37 known pathogen species, in addition, unigenes encoding virulence, signaling, host stress tolerance, and potential effector were also predicted. This research uncovered transcriptional profiling during the early phase interaction between R. solani AG1 IA strain and Z. japonica, and will greatly help identify key pathogenicity of AG1 IA strain.

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…

Early Childhood Open-Mindedness: An Investigation into Preservice Teachers' Capacity to Address Controversial Issues

ERIC Educational Resources Information Center

Bautista, Nazan; Misco, Thomas; Quaye, Stephen John

2018-01-01

We investigated the characteristics of early childhood education (ECE) preservice teachers (PSTs) who were identified as closed minded and their capacity to deal with controversial issues. We define open-mindedness as the willingness to consider experiences, beliefs, values, and perspectives that differ from one's own. First, we used quantitative…

Financial strain is associated with increased oxidative stress levels: the Women's Health and Aging Studies.

PubMed

Palta, Priya; Szanton, Sarah L; Semba, Richard D; Thorpe, Roland J; Varadhan, Ravi; Fried, Linda P

2015-01-01

Elevated oxidative stress levels may be one mechanism contributing to poor health outcomes. Financial strain and oxidative stress are each predictors of morbidity and mortality, but little research has investigated their relationship. Community-dwelling older adults (n = 728) from the Women's Health and Aging Studies I and II were included in this cross-sectional analysis. Financial strain was ascertained as an ordinal response to: "At the end of the month, do you have more than enough money left over, just enough, or not enough?" Oxidative stress was measured using serum protein carbonyl concentrations. Linear regression was used to quantify the relationship between financial strain and oxidative stress. Participants who reported high financial strain exhibited 13.4% higher protein carbonyl concentrations compared to individuals who reported low financial strain (p = 0.002). High financial strain may be associated with increased oxidative stress, suggesting that oxidative stress could mediate associations between financial strain and poor health. Copyright © 2015 Elsevier Inc. All rights reserved.

Fiber Bragg Gratings, IT Techniques and Strain Gauge Validation for Strain Calculation on Aged Metal Specimens

PubMed Central

Montero, Ander; de Ocariz, Idurre Saez; Lopez, Ion; Venegas, Pablo; Gomez, Javier; Zubia, Joseba

2011-01-01

This paper studies the feasibility of calculating strains in aged F114 steel specimens with Fiber Bragg Grating (FBG) sensors and infrared thermography (IT) techniques. Two specimens have been conditioned under extreme temperature and relative humidity conditions making comparative tests of stress before and after aging using different adhesives. Moreover, a comparison has been made with IT techniques and conventional methods for calculating stresses in F114 steel. Implementation of Structural Health Monitoring techniques on real aircraft during their life cycle requires a study of the behaviour of FBG sensors and their wiring under real conditions, before using them for a long time. To simulate aging, specimens were stored in a climate chamber at 70 °C and 90% RH for 60 days. This study is framed within the Structural Health Monitoring (SHM) and Non Destructuve Evaluation (NDE) research lines, integrated into the avionics area maintained by the Aeronautical Technologies Centre (CTA) and the University of the Basque Country (UPV/EHU). PMID:22346619

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.

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

Preterm birth-associated cost of early intervention services: an analysis by gestational age.

PubMed

Clements, Karen M; Barfield, Wanda D; Ayadi, M Femi; Wilber, Nancy

2007-04-01

Characterizing the cost of preterm birth is important in assessing the impact of increasing prematurity rates and evaluating the cost-effectiveness of therapies to prevent preterm delivery. To assess early intervention costs that are associated with preterm births, we estimated the program cost of early intervention services for children who were born in Massachusetts, by gestational age at birth. Using the Pregnancy to Early Life Longitudinal Data Set, birth certificates for infants who were born in Massachusetts between July 1999 and June 2000 were linked to early intervention claims through 2003. We determined total program costs, in 2003 dollars, of early intervention and mean cost per surviving infant by gestational age. Costs by plurality, eligibility criteria, provider discipline, and annual costs for children's first 3 years also were examined. Overall, 14,033 of 76,901 surviving infants received early intervention services. Program costs totaled almost $66 million, with mean cost per surviving infant of $857. Mean cost per infant was highest for children who were 24 to 31 weeks' gestational age ($5393) and higher for infants who were 32 to 36 weeks' gestational age ($1578) compared with those who were born at term ($725). Cost per surviving infant generally decreased with increasing gestational age. Among children in early intervention, mean cost per child was higher for preterm infants than for term infants. At each gestational age, mean cost per surviving infant was higher for multiples than for singletons, and annual early intervention costs were higher for toddlers than for infants. Compared with their term counterparts, preterm infants incurred higher early intervention costs. This information along with data on birth trends will inform budget forecasting for early intervention programs. Costs that are associated with early childhood developmental services must be included when considering the long-term costs of prematurity.

Dating human cultural capacity using phylogenetic principles

PubMed Central

Lind, J.; Lindenfors, P.; Ghirlanda, S.; Lidén, K.; Enquist, M.

2013-01-01

Humans have genetically based unique abilities making complex culture possible; an assemblage of traits which we term “cultural capacity”. The age of this capacity has for long been subject to controversy. We apply phylogenetic principles to date this capacity, integrating evidence from archaeology, genetics, paleoanthropology, and linguistics. We show that cultural capacity is older than the first split in the modern human lineage, and at least 170,000 years old, based on data on hyoid bone morphology, FOXP2 alleles, agreement between genetic and language trees, fire use, burials, and the early appearance of tools comparable to those of modern hunter-gatherers. We cannot exclude that Neanderthals had cultural capacity some 500,000 years ago. A capacity for complex culture, therefore, must have existed before complex culture itself. It may even originated long before. This seeming paradox is resolved by theoretical models suggesting that cultural evolution is exceedingly slow in its initial stages. PMID:23648831

Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age

PubMed Central

Lanza, Ian R.; Henderson, Gregory C.; Rao, Rajesh R.; Spiegelman, Bruce M.

2015-01-01

Context: Skeletal muscle from sedentary older adults exhibits reduced mitochondrial abundance and oxidative capacity. Objective: The primary objective was to determine whether 8 weeks of combined training (CT) has a more robust effect than endurance training (ET) or resistance training (RT) on mitochondrial physiology in healthy young (18–30 years) and older (≥65 years) adults. Intervention: Thirty-four young and 31 older adults were randomly assigned to 8 weeks of ET, RT, and control/CT. Control subjects completed 8 weeks of no exercise (control) followed by 8 weeks of CT. Body composition, skeletal muscle strength, and peak oxygen uptake were measured before and after the intervention. Vastus lateralis muscle biopsy samples were obtained before and 48 hours after the intervention. Mitochondrial physiology was evaluated by high-resolution respirometry and expression of mitochondrial proteins and transcription factors by quantitative PCR and immunoblotting. Results: ET and CT significantly increased oxidative capacity and expression of mitochondrial proteins and transcription factors. All training modalities improved body composition, cardiorespiratory fitness, and skeletal muscle strength. CT induced the most robust improvements in mitochondria-related outcomes and physical characteristics despite lower training volumes for the ET and RT components. Importantly, most of the adaptations to training occurred independent of age. Conclusion: Collectively, these results demonstrate that both ET and CT increase muscle mitochondrial abundance and capacity although CT induced the most robust improvements in the outcomes measured. In conclusion, CT provides a robust exercise regimen to improve muscle mitochondrial outcomes and physical characteristics independent of age. PMID:25599385

Mineral content of eggs differs with hens strain, age and rearing environment

USDA-ARS?s Scientific Manuscript database

Egg nutrient quality is strongly influenced by hen diet but is also affected by rearing environment, hen strain and hen age. The objective of the current study was to determine the effect of: 1) conventional battery cages 2) enrichable cage systems 3) enriched colony housing 4) cage free and 5) free...

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.

External prognostic validations and comparisons of age- and gender-adjusted exercise capacity predictions.

PubMed

Kim, Esther S H; Ishwaran, Hemant; Blackstone, Eugene; Lauer, Michael S

2007-11-06

The purpose of this study was to externally validate the prognostic value of age- and gender-based nomograms and categorical definitions of impaired exercise capacity (EC). Exercise capacity predicts death, but its use in routine clinical practice is hampered by its close correlation with age and gender. For a median of 5 years, we followed 22,275 patients without known heart disease who underwent symptom-limited stress testing. Models for predicted or impaired EC were identified by literature search. Gender-specific multivariable proportional hazards models were constructed. Four methods were used to assess validity: Akaike Information Criterion (AIC), right-censored c-index in 100 out-of-bootstrap samples, the Nagelkerke Index R2, and calculation of calibration error in 100 bootstrap samples. There were 646 and 430 deaths in 13,098 men and 9,177 women, respectively. Of the 7 models tested in men, a model based on a Veterans Affairs cohort (predicted metabolic equivalents [METs] = 18 - [0.15 x age]) had the highest AIC and R2. In women, a model based on the St. James Take Heart Project (predicted METs = 14.7 - [0.13 x age]) performed best. Categorical definitions of fitness performed less well. Even after accounting for age and gender, there was still an important interaction with age, whereby predicted EC was a weaker predictor in older subjects (p for interaction <0.001 in men and 0.003 in women). Several methods describe EC accounting for age and gender-related differences, but their ability to predict mortality differ. Simple cutoff values fail to fully describe EC's strong predictive value.

Host-cell interaction of attenuated and wild-type strains of yellow fever virus can be differentiated at early stages of hepatocyte infection.

PubMed

Lefeuvre, Anabelle; Contamin, Hugues; Decelle, Thierry; Fournier, Christophe; Lang, Jean; Deubel, Vincent; Marianneau, Philippe

2006-05-01

Yellow fever (YF) virus is currently found in tropical Africa and South America, and is responsible for a febrile to severe illness characterized by organ failure and shock. The attenuated YF 17D strain, used in YF vaccine, was derived from the wild-type strain Asibi. Although studies have been done on genetic markers of YF virulence, differentiation of the two strains in terms of host-cell interaction during infection remains elusive. As YF wild-type strains are hepatotropic, we chose a hepatic cell line (HepG2) to study YF virus-host cell interaction. HepG2 cells rapidly produced high titres of infectious viral particles for 17D and Asibi YF strains. However, HepG2 cells were more susceptible to the attenuated 17D virus infection, and only this virus strain induced early apoptosis in these cells. Molecular markers specific for the 17D virus were identified by microarray analysis and confirmed by quantitative RT-PCR analysis. As early as 1h postinfection, three genes, (IEX-1, IRF-1, DEC-1) all implicated in apoptosis pathways, were upregulated. Later in infection (48 h) two other genes (HSP70-1A and 1B), expressed in cases of cellular stress, were highly upregulated in 17D-infected HepG2 cells. The early specific upregulation of these cellular genes in HepG2 cells may be considered markers of the 17D virus. This study on the YF attenuated strain gives a new approach to the analysis of the factors involved in virus attenuation.

Relation Between Motility, Accelerated Aging and Gene Expression in Selected Drosophila Strains under Hypergravity Conditions

NASA Astrophysics Data System (ADS)

Serrano, Paloma; van Loon, Jack J. W. A.; Medina, F. Javier; Herranz, Raúl

2013-02-01

Motility and aging in Drosophila have proven to be highly modified under altered gravity conditions (both in space and ground simulation facilities). In order to find out how closely connected they are, five strains with altered geotactic response or survival rates were selected and exposed to an altered gravity environment of 2 g. By analysing the different motile and behavioural patterns and the median survival rates, we show that altered gravity leads to changes in motility, which will have a negative impact on the flies' survival. Previous results show a differential gene expression between sessile samples and adults and confirm that environmentally-conditioned behavioural patterns constrain flies' gene expression and life span. Therefore, hypergravity is considered an environmental stress factor and strains that do not respond to this new environment experience an increment in motility, which is the major cause for the observed increased mortality also under microgravity conditions. The neutral-geotaxis selected strain (strain M) showed the most severe phenotype, unable to respond to variations in the gravitational field. Alternatively, the opposite phenotype was observed in positive-geotaxis and long-life selected flies (strains B and L, respectively), suggesting that these populations are less sensitive to alterations in the gravitational load. We conclude that the behavioural response has a greater contribution to aging than the modified energy consumption in altered gravity environments.

The effects of two Ureaplasma diversum strains on early pregnancy in heifers.

PubMed Central

Gale, S P

1987-01-01

Two field isolates of Ureaplasma diversum spp. were used to infect heifers at the time of insemination in a preliminary study to observe the effect of infection on early pregnancy. M84-14c-1 was a field isolate from a bull's prepuce typed by immunofluorescence to be similar to U. diversum strain T-44 (Group C). M84-477c-4 was a field isolate from bovine semen typed by immunofluorescence to be similar to U. diversum strain T-288 (Group A). All three heifers infected with M84-477c-4 had a mild granular vulvitis at some time during the trial. None was pregnant when slaughtered 27 days after infection. The result of infection with M84-14c-1, a preputial isolate, was not consistent. One heifer had no infection and a normal pregnancy, one heifer was infected with an abnormal pregnancy, and one heifer was open but ureaplasmas were not detected until day 17 of the trial. PMID:3453276

Effect of irradiation temperature and strain rate on the mechanical properties of V-4Cr-4Ti irradiated to low doses in fission reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zinkle, S.J.; Snead, L.L.; Rowcliffe, A.F.

Tensile tests performed on irradiated V-(3-6%)Cr-(3-6%)Ti alloys indicate that pronounced hardening and loss of strain hardening capacity occurs for doses of 0.1--20 dpa at irradiation temperatures below {approximately}330 C. The amount of radiation hardening decreases rapidly for irradiation temperatures above 400 C, with a concomitant increase in strain hardening capacity. Low-dose (0.1--0.5 dpa) irradiation shifts the dynamic strain aging regime to higher temperatures and lower strain rates compared to unirradiated specimens. Very low fracture toughness values were observed in miniature disk compact specimens irradiated at 200--320 C to {approximately}1.5--15 dpa and tested at 200 C.

Telomere length and early severe social deprivation: linking early adversity and cellular aging

PubMed Central

Drury, SS; Theall, K; Gleason, MM; Smyke, AT; De Vivo, I; Wong, JYY; Fox, NA; Zeanah, CH; Nelson, CA

2012-01-01

Accelerated telomere length attrition has been associated with psychological stress and early adversity in adults; however, no studies have examined whether telomere length in childhood is associated with early experiences. The Bucharest Early Intervention Project is a unique randomized controlled trial of foster care placement compared with continued care in institutions. As a result of the study design, participants were exposed to a quantified range of time in institutional care, and represented an ideal population in which to examine the association between a specific early adversity, institutional care and telomere length. We examined the association between average relative telomere length, telomere repeat copy number to single gene copy number (T/S) ratio and exposure to institutional care quantified as the percent of time at baseline (mean age 22 months) and at 54 months of age that each child lived in the institution. A significant negative correlation between T/S ratio and percentage of time was observed. Children with greater exposure to institutional care had significantly shorter relative telomere length in middle childhood. Gender modified this main effect. The percentage of time in institutional care at baseline significantly predicted telomere length in females, whereas the percentage of institutional care at 54 months was strongly predictive of telomere length in males. This is the first study to demonstrate an association between telomere length and institutionalization, the first study to find an association between adversity and telomere length in children, and contributes to the growing literature linking telomere length and early adversity. PMID:21577215

Transcriptomic analysis of two Beauveria bassiana strains grown on cuticle extracts of the silkworm uncovers their different metabolic response at early infection stage.

PubMed

Wang, Jing-Jie; Bai, Wen-Wen; Zhou, Wei; Liu, Jing; Chen, Jie; Liu, Xiao-Yuan; Xiang, Ting-Ting; Liu, Ren-Hua; Wang, Wen-Hui; Zhang, Bao-Ling; Wan, Yong-Ji

2017-05-01

Beauveria bassiana is an important entomopathogenic fungus which not only widely distributes in the environment but also shows phenotypic diversity. However, the mechanism of pathogenic differences among natural B. bassiana strains has not been revealed at transcriptome-wide level. In the present study, in order to explore the mechanism, two B. bassiana strains with different pathogenicity were isolated from silkworms (Bombyx mori L.) and selected to analyze the gene expression of early stage by culturing on cuticle extracts of the silkworm and using RNA-sequencing technique. A total of 2108 up-regulated and 1115 down-regulated genes were identified in B. bassiana strain GXsk1011 (hyper-virulent strain) compared with B. bassiana strain GXtr1009 (hypo-virulent strain), respectively. The function categorization of differential expressed genes (DEGs) showed that most of them involved in metabolic process, biosynthesis of secondary metabolites, catalytic activity, and some involved in nutrition uptake, adhesion and host defense were also noted. Based on our data, distinct pathogenicity among different strains of B. bassiana may largely attribute to unique gene expression pattern which differed at very early infection process. Most of the genes involved in conidia adhesion, cuticle degradation and fungal growth were up-regulated in hyper-virulent B. bassiana strain GXsk1011. Furthermore, in combination with fungal growth analysis, our research provided a clue that fungal growth may also play an important role during early infection process. The results will help to explain why different B. bassiana strains show distinct pathogenicity on the same host even under same condition. Moreover, the transcriptome data were also useful for screening potential virulence factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Absence of dynamic strain aging in an additively manufactured nickel-base superalloy.

PubMed

Beese, Allison M; Wang, Zhuqing; Stoica, Alexandru D; Ma, Dong

2018-05-25

Dynamic strain aging (DSA), observed macroscopically as serrated plastic flow, has long been seen in nickel-base superalloys when plastically deformed at elevated temperatures. Here we report the absence of DSA in Inconel 625 made by additive manufacturing (AM) at temperatures and strain rates where DSA is present in its conventionally processed counterpart. This absence is attributed to the unique AM microstructure of finely dispersed secondary phases (carbides, N-rich phases, and Laves phase) and textured grains. Based on experimental observations, we propose a dislocation-arrest model to elucidate the criterion for DSA to occur or to be absent as a competition between dislocation pipe diffusion and carbide-carbon reactions. With in situ neutron diffraction studies of lattice strain evolution, our findings provide a new perspective for mesoscale understanding of dislocation-solute interactions and their impact on work-hardening behaviors in high-temperature alloys, and have important implications for tailoring thermomechanical properties by microstructure control via AM.

Loss of proliferation and differentiation capacity of aged human periodontal ligament stem cells and rejuvenation by exposure to the young extrinsic environment.

PubMed

Zheng, Wei; Wang, Shi; Ma, Dandan; Tang, Liang; Duan, Yinzhong; Jin, Yan

2009-09-01

The application of periodontal ligament stem cells (PDLSCs) may be effective for periodontal regenerative therapy. As tissue regenerative potential may be negatively regulated by aging, whether aging and its microenvironment modify human PDLSCs remains a question. In this study, we compared the proliferation and differentiation capacity of PDLSCs obtained from young and aged donors. Then, we exposed aged PDLSCs to young periodontal ligament cell-conditioned medium (PLC-CM), and young PDLSCs were exposed to aged PLC-CM. Morphological appearance, colony-forming assay, cell cycle analysis, osteogenic and adipogenic induction media, gene expression of cementoblast phenotype, and in vivo differentiation capacities of PDLSCs were evaluated. PDLSCs obtained from aged donors exhibited decreased proliferation and differentiation capacity when compared with those from young donors. Young PLC-CM enhanced the proliferation and differentiation capacity of PDLSCs from aged donors. Aged PDLSCs induced by young PLC-CM showed enhanced tissue-regenerative capacity to produce cementum/periodontal ligament-like structures, whereas young PDLSCs induced by aged PLC-CM transplants mainly formed connective tissues. To our knowledge, this is the first study to mimic the developmental microenvironment of PDLSCs in vitro, and our data suggest that age influences the proliferation and differentiation potential of human PDLSCs, and that the activity of human PDLSCs can be modulated by the extrinsic microenvironment.

Reduced dopamine receptors and transporters but not synthesis capacity in normal aging adults: a meta-analysis.

PubMed

Karrer, Teresa M; Josef, Anika K; Mata, Rui; Morris, Evan D; Samanez-Larkin, Gregory R

2017-09-01

Many theories of cognitive aging are based on evidence that dopamine (DA) declines with age. Here, we performed a systematic meta-analysis of cross-sectional positron emission tomography and single-photon emission-computed tomography studies on the average effects of age on distinct DA targets (receptors, transporters, or relevant enzymes) in healthy adults (N = 95 studies including 2611 participants). Results revealed significant moderate to large, negative effects of age on DA transporters and receptors. Age had a significantly larger effect on D1- than D2-like receptors. In contrast, there was no significant effect of age on DA synthesis capacity. The average age reductions across the DA system were 3.7%-14.0% per decade. A meta-regression found only DA target as a significant moderator of the age effect. This study precisely quantifies prior claims of reduced DA functionality with age. It also identifies presynaptic mechanisms (spared synthesis capacity and reduced DA transporters) that may partially account for previously unexplained phenomena whereby older adults appear to use dopaminergic resources effectively. Recommendations for future studies including minimum required samples sizes are provided. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

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

Interplay of genes and early mother-child relationship in the development of self-regulation from toddler to preschool age.

PubMed

Kochanska, Grazyna; Philibert, Robert A; Barry, Robin A

2009-11-01

A broad capacity for deliberate self-regulation plays a key role in emotion regulation. This longitudinal investigation from infancy to preschool age examines genotype by environment (G x E) interaction in the development of self-regulation, using molecular measures of children's genotypes and observed measures of the quality of early mother-child relationship, as reflected in attachment organization in infancy. In 89 children, we assessed the polymorphism in the serotonin transporter gene (5-HTTLPR, ss/sl vs. ll allele status), security of attachment to mothers at 15 months in the Strange Situation, and children's ability for self-regulation at 25, 38, and 52 months, using behavioral batteries of tasks that called for deliberately suppressing a dominant response and performing instead a sub-dominant response. There was a robust G x E interaction between genetic risk and the quality of early relationship. Among children who carried a short 5-HTTLPR allele (ss/sl ), those who were insecurely attached developed poor regulatory capacities, but those who were securely attached developed as good regulatory capacities as children who were homozygotic for the long allele (ll ). There was no effect of security for ll homozygotes. Those findings, consistent with diathesis-stress model, bridge research on self-regulation in typically developing children with research on non-human primates and research on psychopathology. They also indicate that a secure attachment relationship can serve as a protective factor in the presence of risk conferred by a genotype.

Age-related decline in verbal learning is moderated by demographic factors, working memory capacity, and presence of amnestic mild cognitive impairment.

PubMed

Constantinidou, Fofi; Zaganas, Ioannis; Papastefanakis, Emmanouil; Kasselimis, Dimitrios; Nidos, Andreas; Simos, Panagiotis G

2014-09-01

Age-related memory changes are highly varied and heterogeneous. The study examined the rate of decline in verbal episodic memory as a function of education level, auditory attention span and verbal working memory capacity, and diagnosis of amnestic mild cognitive impairment (a-MCI). Data were available on a community sample of 653 adults aged 17-86 years and 70 patients with a-MCI recruited from eight broad geographic areas in Greece and Cyprus. Measures of auditory attention span and working memory capacity (digits forward and backward) and verbal episodic memory (Auditory Verbal Learning Test [AVLT]) were used. Moderated mediation regressions on data from the community sample did not reveal significant effects of education level on the rate of age-related decline in AVLT indices. The presence of a-MCI was a significant moderator of the direct effect of Age on both immediate and delayed episodic memory indices. The rate of age-related decline in verbal episodic memory is normally mediated by working memory capacity. Moreover, in persons who display poor episodic memory capacity (a-MCI group), age-related memory decline is expected to advance more rapidly for those who also display relatively poor verbal working memory capacity.

Core gut microbiota in Jinhua pigs and its correlation with strain, farm and weaning age.

PubMed

Yang, Hua; Xiao, Yingping; Wang, Junjun; Xiang, Yun; Gong, Yujie; Wen, Xueting; Li, Defa

2018-05-01

Gut microbial diversity and the core microbiota of the Jinhua pig, which is a traditional, slow-growing Chinese breed with a high body-fat content, were examined from a total of 105 fecal samples collected from 6 groups of pigs at 3 weaning ages that originated from 2 strains and were raised on 3 different pig farms. The bacterial community was analyzed following high-throughput pyrosequencing of 16S rRNA genes, and the fecal concentrations of short-chain fatty acids (SCFAs) were measured by gas chromatograph. Our results showed that Firmicutes and Bacteroidetes were the dominant phyla, and Lactobacillus, Streptococcus, Clostridium, SMB53, and Bifidobacterium were the most abundant genera. Fifteen predominant genera present in every Jinhua pig sample constituted a phylogenetic core microbiota and included the probiotics Lactobacillus and Bifidobacterium, and the SCFA-producing bacteria Clostridium, Prevotella, Bacteroides, Coprococcus, Roseburia, Ruminococcus, Blautia, and Butyricicoccus. Comparisons of the microbiota compositions and SCFA concentrations across the 6 groups of pigs demonstrated that genetic background and weaning age affected the structure of the gut microbiota more significantly than the farm. The relative abundance of the core genera in the pigs, including Lactobacillus, Clostridium, Prevotella, Bacteroides, Roseburia, Ruminococcus, Blautia, and Butyricicoccus varied dramatically in pigs among the 2 origins and 3 weaning ages, while Oscillospira, Megasphaera, Parabacteroides, and Corynebacterium differed among pigs from different farms. Interestingly, there was a more significant influence of strain and weaning age than of rearing farm on the SCFA concentrations. Therefore, strain and weaning age appear to be the more important factors shaping the intestinal microbiome of pigs.

Where Is ELSA? The Early to Late Shift in Aging

PubMed Central

Buchler, Norbou; Dobbins, Ian G.; Cabeza, Roberto

2012-01-01

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. PMID:22114083

Dietary Probiotic Bacillus subtilis Strain fmbj Increases Antioxidant Capacity and Oxidative Stability of Chicken Breast Meat during Storage

PubMed Central

Bai, Wen Kai; Zhang, Fei Jing; He, Tian Jin; Su, Peng Wei; Ying, Xiong Zhi; Zhang, Li Li; Wang, Tian

2016-01-01

This study was aimed to measure the dietary effects of probiotic Bacillus subtilis strain fmbj (BS fmbj) on antioxidant capacity and oxidative stability of chicken breast meat during storage. Treatment groups were fed the basal diet with BS fmbj at 0 g/kg (CON), 0.2 g/kg (BS-1), 0.3 g/kg (BS-2), or 0.4 g/kg (BS-3) doses without antibiotics. During 8 days of storage at 4°C, BS-2 group showed a significant improvement (P < 0.05) on meat quality (pH, Drip loss, Cooking loss, Shear force, color L*, a*, b*), free radical scavenging activity (DPPH, ABTS+, H2O2), tissues antioxidant enzyme capacity (SOD, CAT, GSH-Px, GSH, T-SH), mitochondria antioxidant enzyme capacity (MnSOD, GPx, GSH), mRNA expression of antioxidant genes (Nrf2, HO-1, SOD, CAT, GSH-Px) and mitochondrial function genes (avUCP, NRF1, NRF2, TFAM, PGC-1α), oxidative damage index (MDA, ROS, PC, 8-OHdG), and MMP level in chicken breast meat as compared to the CON group. These results indicate that dietary BS fmbj in broiler diets can protect breast meat against the storage-induced oxidative stress by improving their free radical scavenging capacity and antioxidant activity during 8 days of storage at 4°C. PMID:27907152

Experimental Study on the Coupling Mechanism of Early-strength Backfill and Rock

NASA Astrophysics Data System (ADS)

Wang, Mingxu

2017-11-01

In order to study the interaction mechanism between the ore rock and backfill at the early stage, paraffin is chosen as the cementing agent. Based on the damage mechanics and fractal theory, the interaction mechanism between the ore rock and backfill is characterized by the relevant tests on the complex of proportioned ore rock and backfill with resistance strain gauge, crack propagation, microscopic imaging and AE. The experimental results showed that: 1) Through the axial loading test, compared with the early strength of the cemented filling and paraffin mechanical deformation characteristics, the stress and strain curves of the two had a common linear deformation law, while in the early strength of the filling elastic capacity strong, with a certain degree of resilience. 2) The bearing capacity of the backfill was weak, but the deformation ability was strong. During the bearing process, the deformation of the upper load was mainly caused by the ore rock, which leaded to the damage of the rock. 3) The distribution of AE points during the co-carrying of the filling and the ore rock was monitored by the acoustic emission instrument. The damage occurred mainly in the contact zone between the backfill and the ore rock zone. The corresponding AE point distribution also validated the crack happening.

Age-related changes in body composition in laboratory rats: Strain and gender comparisons

EPA Science Inventory

Long Evans (LE), Sprague Dawley (SD), Fischer 344 (F344), and Brown Norway (BN) rats are all commonly used as laboratory research subjects. These strains have been studied under many conditions, but few studies have measured changes in body composition as the animals age. Underst...

Aerobic capacity in speed-power athletes aged 20-90 years vs endurance runners and untrained participants.

PubMed

Kusy, K; Zieliński, J

2014-02-01

We studied relationships between age and aerobic capacity in three groups of subjects adhering to different exercise modalities. A total of 203 men aged 20-90 years were examined: 52 speed-power track and field athletes (SP), 89 endurance runners (ER) and 62 untrained individuals (UT). Maximal exercise characteristics were obtained during a graded treadmill test until exhaustion: oxygen uptake (VO2max), heart rate (HRmax), oxygen pulse (O2 Pulsemax) and maximal distance (Distmax). Information about training history and weekly training amount was collected. A linear model of regression was adopted. VO2max in SP was lower than in ER, but significantly higher than in UT. The cross-sectional rates of decline in body mass-adjusted VO2max and Distmax were significantly smaller in SP than in ER and UT. About 80 years of age, the levels of VO2max and Distmax reached similar values in SP and ER. The decline in HRmax, but not in O2 Pulsemax was suggested as a cardiac adaptation accounting for between-group differences in VO2max loss. Weekly training volume was a significant positive predictor of age-related changes in aerobic capacity. In conclusion, not only endurance, but also speed-power exercise appears adequate to ensure an elevated aerobic capacity at old age. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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.

Methane storage capacity of the early martian cryosphere

NASA Astrophysics Data System (ADS)

Lasue, Jeremie; Quesnel, Yoann; Langlais, Benoit; Chassefière, Eric

2015-11-01

Methane is a key molecule to understand the habitability of Mars due to its possible biological origin and short atmospheric lifetime. Recent methane detections on Mars present a large variability that is probably due to relatively localized sources and sink processes yet unknown. In this study, we determine how much methane could have been abiotically produced by early Mars serpentinization processes that could also explain the observed martian remanent magnetic field. Under the assumption of a cold early Mars environment, a cryosphere could trap such methane as clathrates in stable form at depth. The extent and spatial distribution of these methane reservoirs have been calculated with respect to the magnetization distribution and other factors. We calculate that the maximum storage capacity of such a clathrate cryosphere is about 2.1 × 1019-2.2 × 1020 moles of CH4, which can explain sporadic releases of methane that have been observed on the surface of the planet during the past decade (∼1.2 × 109 moles). This amount of trapped methane is sufficient for similar sized releases to have happened yearly during the history of the planet. While the stability of such reservoirs depends on many factors that are poorly constrained, it is possible that they have remained trapped at depth until the present day. Due to the possible implications of methane detection for life and its influence on the atmospheric and climate processes on the planet, confirming the sporadic release of methane on Mars and the global distribution of its sources is one of the major goals of the current and next space missions to Mars.

Age-Related Changes in Visual Temporal Order Judgment Performance: Relation to Sensory and Cognitive Capacities

PubMed Central

Busey, Thomas; Craig, James; Clark, Chris; Humes, Larry

2010-01-01

Five measures of temporal order judgments were obtained from 261 participants, including 146 elder, 44 middle aged, and 71 young participants. Strong age group differences were observed in all five measures, although the group differences were reduced when letter discriminability was matched for all participants. Significant relations were found between these measures of temporal processing and several cognitive and sensory assays, and structural equation modeling revealed the degree to which temporal order processing can be viewed as a latent factor that depends in part on contributions from sensory and cognitive capacities. The best-fitting model involved two different latent factors representing temporal order processing at same and different locations, and the sensory and cognitive factors were more successful predicting performance in the different location factor than the same-location factor. Processing speed, even measured using high-contrast symbols on a paper-and-pencil test, was a surprisingly strong predictor of variability in both latent factors. However, low-level sensory measures also made significant contributions to the latent factors. The results demonstrate the degree to which temporal order processing relates to other perceptual and cognitive capacities, and address the question of whether age-related declines in these capacities share a common cause. PMID:20580644

Age-related changes in visual temporal order judgment performance: Relation to sensory and cognitive capacities.

PubMed

Busey, Thomas; Craig, James; Clark, Chris; Humes, Larry

2010-08-06

Five measures of temporal order judgments were obtained from 261 participants, including 146 elder, 44 middle aged, and 71 young participants. Strong age group differences were observed in all five measures, although the group differences were reduced when letter discriminability was matched for all participants. Significant relations were found between these measures of temporal processing and several cognitive and sensory assays, and structural equation modeling revealed the degree to which temporal order processing can be viewed as a latent factor that depends in part on contributions from sensory and cognitive capacities. The best-fitting model involved two different latent factors representing temporal order processing at same and different locations, and the sensory and cognitive factors were more successful predicting performance in the different location factor than the same-location factor. Processing speed, even measured using high-contrast symbols on a paper-and-pencil test, was a surprisingly strong predictor of variability in both latent factors. However, low-level sensory measures also made significant contributions to the latent factors. The results demonstrate the degree to which temporal order processing relates to other perceptual and cognitive capacities, and address the question of whether age-related declines in these capacities share a common cause. Copyright 2010 Elsevier Ltd. All rights reserved.

Shortened estrous cycle length, increased FSH levels, FSH variance, oocyte spindle aberrations, and early declining fertility in aging senescence-accelerated mouse prone-8 (SAMP8) mice: concomitant characteristics of human midlife female reproductive aging.

PubMed

Bernstein, Lori R; Mackenzie, Amelia C L; Kraemer, Duane C; Morley, John E; Farr, Susan; Chaffin, Charles L; Merchenthaler, István

2014-06-01

Women experience a series of specific transitions in their reproductive function with age. Shortening of the menstrual cycle begins in the mid to late 30s and is regarded as the first sign of reproductive aging. Other early changes include elevation and increased variance of serum FSH levels, increased incidences of oocyte spindle aberrations and aneuploidy, and declining fertility. The goal of this study was to investigate whether the mouse strain senescence-accelerated mouse-prone-8 (SAMP8) is a suitable model for the study of these midlife reproductive aging characteristics. Midlife SAMP8 mice aged 6.5-7.85 months (midlife SAMP8) exhibited shortened estrous cycles compared with SAMP8 mice aged 2-3 months (young SAMP8, P = .0040). Midlife SAMP8 mice had high FSH levels compared with young SAMP8 mice, and mice with a single day of high FSH exhibited statistically elevated FSH throughout the cycle, ranging from 1.8- to 3.6-fold elevation on the days of proestrus, estrus, metestrus, and diestrus (P < .05). Midlife SAMP8 mice displayed more variance in FSH than young SAMP8 mice (P = .01). Midlife SAMP8 ovulated fewer oocytes (P = .0155). SAMP8 oocytes stained with fluorescently labeled antitubulin antibodies and scored in fluorescence microscopy exhibited increased incidence of meiotic spindle aberrations with age, from 2/126 (1.59%) in young SAMP8 to 38/139 (27.3%) in midlife SAMP8 (17.2-fold increase, P < .0001). Finally, SAMP8 exhibited declining fertility from 8.9 pups/litter in young SAMP8 to 3.5 pups/litter in midlife SAMP8 mice (P < .0001). The age at which these changes occur is younger than for most mouse strains, and their simultaneous occurrence within a single strain has not been described previously. We propose that SAMP8 mice are a model of midlife human female reproductive aging.

Early-shared Mycobacterium bovis bacillus Calmette-Guérin sub-strains induce Th1 cytokine production in vivo.

PubMed

Taniguchi, Keiichi; Miyatake, Yuuji; Hayashi, Daisuke; Takami, Atsuro; Itoh, Saotomo; Yamamoto, Saburo; Hida, Shigeaki; Onozaki, Kikuo; Takii, Takemasa

2015-11-01

Interleukin-12 is one of the cytokines that induce acquired immunity by progressing the differentiation of T cells. When antigens are presented by APCs, including macrophages and DCs, T cells are activated and produce the Th1 cytokines IL-2 and IFN-γ. We have previously reported greater IL-12 production from macrophages infected with early-shared BCG sub-strains (ex. BCG-Japan, -Sweden) than from those infected with late-shared BCG (ex. BCG-Pasteur and -Connaught) . In this study, we investigated the Th1 cytokine-inducing activity of splenocytes co-cultured with BCG-infected DCs. Early-shared BCG-infected DCs produced IL-12 and TNF-α⋅ Furthermore, when they were co-cultured with purified protein derivative-stimulated DCs, the splenocytes of mice immunized with BCG-Tokyo/Japan produced more Th1 cytokine than did those of mice immunized with BCG-Connaught. In conclusion, early-shared BCG sub-strains more strongly induce Th1 cytokine production in vivo. This study provides basic information to inform the selection of candidates for primary vaccination. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

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.

Job strain in the public sector and hospital in-patient care use in old age: a 28-year prospective follow-up.

PubMed

von Bonsdorff, Mikaela Birgitta; von Bonsdorff, Monika; Kulmala, Jenni; Törmäkangas, Timo; Seitsamo, Jorma; Leino-Arjas, Päivi; Nygård, Clas-Håkan; Ilmarinen, Juhani; Rantanen, Taina

2014-05-01

high job strain increases the risk of health decline, but little is known about the specific consequences and long-term effects of job strain on old age health. purpose was to investigate whether physical and mental job strain in midlife was associated with hospital care use in old age. study population included 5,625 Finnish public sector employees aged 44-58 years who worked in blue- and white-collar professions in 1981. The number of in-patient hospital care days was collected from the Finnish Hospital Discharge Register for the 28-year follow-up period. rates of hospital care days per 1,000 person-years for men were 7.78 (95% confidence interval [CI] 7.71-7.84) for low, 9.68 (95% CI 9.50-9.74) for intermediate and 12.56 (95% CI 12.47-12.66) for high physical job strain in midlife. The corresponding rates for women were 6.63 (95% CI 6.57-6.68), 7.91 (95% CI 7.87-7.95) and 10.35 (95% CI 10.25-10.42), respectively. Rates were parallel but lower for mental job strain. Reporting high physical job strain in midlife increased the risk of hospital care in old age compared with those who reported low job strain, fully adjusted incidence rate ratio 1.17 (95% CI 1.00-1.38) for men and 1.42 (95% CI 1.25-1.61) for women. These associations were robust in analyses confined to hospital care that took place after the employees had turned 65 years. exposure to high mental and, particularly, high physical job strain in midlife may set employees on a higher healthcare use trajectory which persists into old age.

Probing the early development of visual working memory capacity with functional near-infrared spectroscopy

PubMed Central

Buss, Aaron T.; Fox, Nicholas; Boas, David A.; Spencer, John P.

2013-01-01

Visual working memory (VWM) is a core cognitive system with a highly limited capacity. The present study is the first to examine VWM capacity limits in early development using functional neuroimaging. We recorded optical neuroimaging data while 3- and 4-year-olds completed a change detection task where they detected changes in the shapes of objects after a brief delay. Near-infrared sources and detectors were placed over the following 10–20 positions: F3 and F5 in left frontal cortex, F4 and F6 in right frontal cortex, P3 and P5 in left parietal cortex, and P4 and P6 in right parietal cortex. The first question was whether we would see robust task-specific activation of the frontal-parietal network identified in the adult fMRI literature. This was indeed the case: three left frontal channels and 11 of 12 parietal channels showed a statistically robust difference between the concentration of oxygenated and deoxygenated hemoglobin following the presentation of the sample array. Moreover, four channels in the left hemisphere near P3, P5, and F5 showed a robust increase as the working memory load increased from 1–3 items. Notably, the hemodynamic response did not asymptote at 1–2 items as expected from previous fMRI studies with adults. Finally, 4-year-olds showed a more robust parietal response relative to 3-year-olds, and an increasing sensitivity to the memory load manipulation. These results demonstrate that fNIRS is an effective tool to study the neural processes that underlie the early development of VWM capacity. PMID:23707803

Probing the early development of visual working memory capacity with functional near-infrared spectroscopy.

PubMed

Buss, Aaron T; Fox, Nicholas; Boas, David A; Spencer, John P

2014-01-15

Visual working memory (VWM) is a core cognitive system with a highly limited capacity. The present study is the first to examine VWM capacity limits in early development using functional neuroimaging. We recorded optical neuroimaging data while 3- and 4-year-olds completed a change detection task where they detected changes in the shapes of objects after a brief delay. Near-infrared sources and detectors were placed over the following 10-20 positions: F3 and F5 in left frontal cortex, F4 and F6 in right frontal cortex, P3 and P5 in left parietal cortex, and P4 and P6 in right parietal cortex. The first question was whether we would see robust task-specific activation of the frontal-parietal network identified in the adult fMRI literature. This was indeed the case: three left frontal channels and 11 of 12 parietal channels showed a statistically robust difference between the concentration of oxygenated and deoxygenated hemoglobin following the presentation of the sample array. Moreover, four channels in the left hemisphere near P3, P5, and F5 showed a robust increase as the working memory load increased from 1 to 3 items. Notably, the hemodynamic response did not asymptote at 1-2 items as expected from previous fMRI studies with adults. Finally, 4-year-olds showed a more robust parietal response relative to 3-year-olds, and an increasing sensitivity to the memory load manipulation. These results demonstrate that fNIRS is an effective tool to study the neural processes that underlie the early development of VWM capacity. Copyright © 2013 Elsevier Inc. All rights reserved.

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…

Primary early correction of tetralogy of Fallot irrespective of age.

PubMed

Kantorova, Andrea; Zbieranek, Kai; Sauer, Henning; Lilje, Christian; Haun, Christoph; Hraska, Viktor

2008-04-01

The policy of early repair of patients with tetralogy of Fallot, irrespective of age, as opposed to initial palliation with a shunt, remains controversial. The aim of our study was to analyze the midterm outcome of primary early correction of tetralogy of Fallot. Between 1996 and 2005, a total of 61 consecutive patients less than 6 months of age underwent primary correction of tetralogy of Fallot in two institutions. The median age at surgery was 3.3 months, and 27 patients (44%) were younger than 3 months of age, including 12 (20%) newborns. We analyzed the patients in 2 groups: those younger than 3 months of age, and those aged between 3 and 6 months. There was one early (1.6%), and one late death. Actuarial survival was 98.4%, 96.7%, 96.7% at 1, 5, and 10 years respectively, with a median follow up of 4.5 years. There was no difference in survival, bypass time, lengths of ventilation, and hospital stay between the groups. A transjunctional patch was placed significantly more often in the patients younger than 3 months (p = 0.039), with no adverse effect on survival and morbidity during the follow-up. Freedom from reoperation was 98.2%, 92.2%, and 83% at 1, 5, and 10 years respectively, with no difference between the groups. Elective primary repair of tetralogy of Fallot in asymptomatic patients is delayed beyond 3 months of age. In symptomatic patients, primary repair of tetralogy of Fallot is performed irrespective of age, weight and preoperative state. This approach is safe, and provides an excellent midterm outcome with acceptable morbidity and rates of reintervention. The long-term benefits of this approach must be established by careful follow-up, with particular emphasis on arrhythmias, right ventricular function, and exercise performance.

Gender and Age as Moderators of the Relationship between the Efficacy of Vocational Teachers' Personal Resources and Strain.

ERIC Educational Resources Information Center

Pithers, Robert T.; Soden, Rebecca

2002-01-01

Results of the Occupational Stress Inventory completed by 256 vocational teachers showed a significant negative relationship between personal resources (recreation, self-care, social support, rational/cognitive) and occupational strain, differing by gender, age, and type of strain (vocational, psychological, interpersonal, physical). Women and…

Repetitive strain disorder: towards diagnostic criteria.

PubMed Central

Bird, H A; Hill, J

1992-01-01

Thirteen women (mean age 48.2 years; range 25-60 years) all of whom had developed musculoskeletal symptoms during employment in an industrial job with repetitive tasks were referred by their trade unions for adjudication on the cause of symptoms. One had rheumatoid arthritis. A study of the other 12 women provided an opportunity to document the natural history of repetitive strain disorder. Early symptoms of weakness were diffuse but were always relieved by rest. Several months later localisation of symptoms at a tendon, nerve, or enthesis could be predicted from the analysis of the action required in the particular repetitive task. Six of the 12 women required an operation several years later, thus providing histological confirmation of the presence of a lesion. Early loss of grip strength measured by a sphygmomanometer cuff compared with an unaffected control subject and improved by rest may be the most valuable sign in excluding compensation neurosis. The estimated prevalence of repetitive strain disorder defined by these strict criteria was at least 2% in conveyor belt workers. PMID:1417124

Normal myocardial strain values using 2D speckle tracking echocardiography in healthy adults aged 20 to 72 years.

PubMed

Menting, Myrthe E; McGhie, Jackie S; Koopman, Laurens P; Vletter, Wim B; Helbing, Willem A; van den Bosch, Annemien E; Roos-Hesselink, Jolien W

2016-11-01

Evaluation of left ventricular (LV) myocardial deformation by speckle tracking echocardiography (STE) is useful for clinical and research purposes. However, strain measurements depend on the used software. Normative data for QLAB 10 (Philips) are scarce. Additionally, little is known about the influence of anthropometric factors. We aimed to establish normal adult STE-derived strain and strain rate values and to evaluate associations with anthropometrics. One hundred fifty-five healthy subjects aged 20 to 72 years (≥28 subjects per decile) were prospectively gathered and examined with electrocardiography and two-dimensional echocardiography. With STE, we assessed peak systolic LV global longitudinal strain (GLS), segmental longitudinal strain, and strain rate from the three standard apical views. We included 147 healthy subjects (age 44.6±13.7 years, 50% female, GLS -20.8±2.0%). Men had significantly lower GLS than women (-20.1±1.8% vs -21.5±2.0%, P<.001). GLS was significantly lower in subjects with age above 55 years (P=.029), higher blood pressure (P<.001), higher body surface area (BSA, P<.001), larger LV end-systolic and end-diastolic volumes (both P<.001), lower LV ejection fraction (P<.001), and some indices of diastolic function. After multivariable regression analysis, the correlation with systolic blood pressure, E-wave, and LV end-systolic volume remained significant. The systolic strain rates of most segments correlated with BSA. Our study resulted in normative LV GLS values assessed with QLAB 10. Male sex, higher BSA, and higher blood pressure negatively influence GLS. Therefore, these factors should be taken into account for strain interpretation in clinical practice. © 2016, Wiley Periodicals, Inc.

Capacity of Broadly Neutralizing Antibodies to Inhibit HIV-1 Cell-Cell Transmission Is Strain- and Epitope-Dependent

PubMed Central

Reh, Lucia; Magnus, Carsten; Schanz, Merle; Weber, Jacqueline; Uhr, Therese; Rusert, Peter; Trkola, Alexandra

2015-01-01

An increasing number of broadly neutralizing antibodies (bnAbs) are considered leads for HIV-1 vaccine development and novel therapeutics. Here, we systematically explored the capacity of bnAbs to neutralize HIV-1 prior to and post-CD4 engagement and to block HIV-1 cell-cell transmission. Cell-cell spread is known to promote a highly efficient infection with HIV-1 which can inflict dramatic losses in neutralization potency compared to free virus infection. Selection of bnAbs that are capable of suppressing HIV irrespective of the transmission mode therefore needs to be considered to ascertain their in vivo activity in therapeutic use and vaccines. Employing assay systems that allow for unambiguous discrimination between free virus and cell-cell transmission to T cells, we probed a panel of 16 bnAbs for their activity against 11 viruses from subtypes A, B and C during both transmission modes. Over a wide range of bnAb-virus combinations tested, inhibitory activity against HIV-1 cell-cell transmission was strongly decreased compared to free virus transmission. Activity loss varied considerably between virus strains and was inversely associated with neutralization of free virus spread for V1V2- and V3-directed bnAbs. In rare bnAb-virus combinations, inhibition for both transmission modes was comparable but no bnAb potently blocked cell-cell transmission across all probed virus strains. Mathematical analysis indicated an increased probability of bnAb resistance mutations to arise in cell-cell rather than free virus spread, further highlighting the need to block this pathway. Importantly, the capacity to efficiently neutralize prior to CD4 engagement correlated with the inhibition efficacy against free virus but not cell-cell transmitted virus. Pre-CD4 attachment activity proved strongest amongst CD4bs bnAbs and varied substantially for V3 and V1V2 loop bnAbs in a strain-dependent manner. In summary, bnAb activity against divergent viruses varied depending on the

Regional distribution of circumferential residual strains in the human aorta according to age and gender.

PubMed

Sokolis, Dimitrios P; Savva, Giannis D; Papadodima, Stavroula A; Kourkoulis, Stavros K

2017-03-01

The biomechanical response of the human aorta varies with axial location, but little is known about the respective variation of residual strains. Such data are available for common lab animals, but in the traditional opening angle measurement the aorta is considered as an ideal cylinder and average residual strains are measured, so that the spatial variations of local residual strains are not determined. The present study provides opening angle and residual strain data throughout the course and around the circumference of the aorta harvested during autopsy. Opening angle showed notable topographical variation; the highest value was at the top of aortic arch, declining abruptly toward the ascending aorta and to a near-constant value in the descending aorta, and rising in the abdominal aorta. The variation of curvature and of external but not internal residual stretch resembled that of opening angle. Extensive residual stress and wall thickness differences were evidenced among quadrants, with the more pre-stressed being also the thicker quadrants. Gender had overall minor effects, but aging led to increased parameters, occurring earlier in the distal aorta but at later stages becoming predominant proximally. Differences in caliber were pronounced in older subjects, unlike those in opening angle, residual stretches, and thickness that were striking in middle-aged subjects. By contrast, curvature decreased with aging in relation to the smaller percentwise opening angle differences. Detailed knowledge of the zero-stress/no-load geometry of the human aortic wall is critical for an in-depth understanding of aortic physiology, while providing the basis for comparison with disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experience from three years of local capacity development for tsunami early warning in Indonesia: challenges, lessons and the way ahead

NASA Astrophysics Data System (ADS)

Spahn, H.; Hoppe, M.; Vidiarina, H. D.; Usdianto, B.

2010-07-01

Five years after the 2004 tsunami, a lot has been achieved to make communities in Indonesia better prepared for tsunamis. This achievement is primarily linked to the development of the Indonesian Tsunami Early Warning System (InaTEWS). However, many challenges remain. This paper describes the experience with local capacity development for tsunami early warning (TEW) in Indonesia, based on the activities of a pilot project. TEW in Indonesia is still new to disaster management institutions and the public, as is the paradigm of Disaster Risk Reduction (DRR). The technology components of InaTEWS will soon be fully operational. The major challenge for the system is the establishment of clear institutional arrangements and capacities at national and local levels that support the development of public and institutional response capability at the local level. Due to a lack of information and national guidance, most local actors have a limited understanding of InaTEWS and DRR, and often show little political will and priority to engage in TEW. The often-limited capacity of local governments is contrasted by strong engagement of civil society organisations that opt for early warning based on natural warning signs rather than technology-based early warning. Bringing together the various actors, developing capacities in a multi-stakeholder cooperation for an effective warning system are key challenges for the end-to-end approach of InaTEWS. The development of local response capability needs to receive the same commitment as the development of the system's technology components. Public understanding of and trust in the system comes with knowledge and awareness on the part of the end users of the system and convincing performance on the part of the public service provider. Both sides need to be strengthened. This requires the integration of TEW into DRR, clear institutional arrangements, national guidance and intensive support for capacity development at local levels as well as

Total HDL cholesterol efflux capacity in healthy children - Associations with adiposity and dietary intakes of mother and child.

PubMed

Khalil, H; Murrin, C; O'Reilly, M; Viljoen, K; Segurado, R; O'Brien, J; Somerville, R; McGillicuddy, F; Kelleher, C C

2017-01-01

High-density lipoprotein (HDL) cholesterol efflux capacity in adults may be a measure of the atheroprotective property of HDL. Little however, is known about HDL cholesterol efflux capacity in childhood. We aimed to investigate the relationship between HDL cholesterol efflux capacity and childhood anthropometrics in a longitudinal study. Seventy-five children (mean age = 9.4 ± 0.4 years) were followed from birth until the age of 9 years. HDL cholesterol efflux capacity was determined at age 9 by incubating serum-derived HDL-supernatants with 3 H-cholesterol labeled J774 macrophages and percentage efflux determined. Mothers provided dietary information by completing food frequency questionnaires in early pregnancy and then 5 years later on behalf of themselves and their children. Pearson's correlations and multiple regression analyses were conducted to confirm independent associations with HDL efflux. There was a negative correlation between HDL cholesterol efflux capacity and waist circumference at age 5 (r = -0.3, p = 0.01) and age 9 (r = -0.24, p = 0.04) and BMI at age 5 (r = -0.45, p = 0.01) and age 9 (r = -0.19, p = 0.1). Multiple regression analysis showed that BMI at age 5 remained significantly associated with reduced HDL cholesterol efflux capacity (r = -0.45, p < 0.001). HDL-C was negatively correlated with energy-adjusted fat intake (r = -0.24, p = 0.04) and positively correlated with energy-adjusted protein (r = 0.24, p = 0.04) and starch (r = 0.29, p = 0.01) intakes during pregnancy. HDL-C was not significantly correlated with children dietary intake at age 5. There were no significant correlations between maternal or children dietary intake and HDL cholesterol efflux capacity. This novel analysis shows that efflux capacity is negatively associated with adiposity in early childhood independent of HDL-C. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the

[Intervention of antioxidant system function of aged rats by giving fruit juices with different antioxidant capacities].

PubMed

Xu, Jing; Guo, Chang-jiang; Yang, Ji-jun; Wei, Jing-yu; Li, Yun-feng; Pang, Wei; Jiang, Yu-gang; Cheng, Shuang

2005-03-01

To observe the effects of fruit juices with different antioxidant capacity on antioxidant system function of aged rats. Thirty Wistar rats were randomly divided into three groups: pomegranate juice and apple juice as two experimental groups, while distilled water as normal control group. They were administrated fruit juices or distilled water respectively by gavage daily for 4 weeks. At the end of experiment, the antioxidant system function was assessed. The aged rats in pomegranate juice group showed significantly higher serum antioxidant capacity (0.90 +/- 0.13) mmol/L than that in control group (0.79 +/- 0.10) mmol/L (P < 0.05). The concentrations of serum carbonyl and oxLDL were decreased significantly in pomegranate juice group as compared to the control group (P < 0.05). The percentage of injured blood lymphocyte DNA and the ratio of tail length/total length were declined significantly in pomegranate juice group (P < 0.05 and P < 0.01 respectively). The apple juice showed no effects except decreased ratio of tail length/total length of injured lymphocyte DNA. There were no changes in concentrations of serum vitamin C, vitamin E, urinary 8-OH-dG excretion and the activities of serum SOD, GSH-Px, CAT among three groups. The pomegranate juice should possess higher antioxidant capacity and might improve the antioxidant system function of aged rats, while the apple juice is relatively lower in antioxidant capacity and not very effective. The polyphenols in pomegranate juice might be the important functional components.

Early age damage quantification of actively restrained concrete using inverse analysis

NASA Astrophysics Data System (ADS)

Albanna, Ali

Early-age cracking can be a significant problem in concrete pavements, floors, and bridge decks. Cracking occurs when the volumetric changes associated with drying, hydration, and temperature reduction are prevented. Good knowledge about the characteristics of early age concrete is necessary to achieve reliable crack control. Volumetric changes due to shrinkage depend on the type of concrete and its components. It has been found that light weight aggregates can work as internal reservoir to supply the concrete matrix with water that is needed during the early age; this process is called internal curing. Also fibers can give more ductility to the concrete and produce less shrinkage. There is a need to better understand the effects of early age uniaxial restraint on long term concrete mechanical performance. In this study, two types of concrete were studied (high performance fiber reinforced concrete and ordinary concrete) under actively restrained loading conditions to assess the effect on the long term fracture toughness and energy. Single edge notched specimens having dimensions of 250 mm x 150 mm x 75 mm and a notch to depth ratio of 0.33 were caste and used in both direct tension and three point bending. The direct tension tests were carried out on a direct tension loading frame constructed in house that was supplied with two mechanical jacks and load cell.

Development of Non-Verbal Intellectual Capacity in School-Age Children with Cerebral Palsy

ERIC Educational Resources Information Center

Smits, D. W.; Ketelaar, M.; Gorter, J. W.; van Schie, P. E.; Becher, J. G.; Lindeman, E.; Jongmans, M. J.

2011-01-01

Background: Children with cerebral palsy (CP) are at greater risk for a limited intellectual development than typically developing children. Little information is available which children with CP are most at risk. This study aimed to describe the development of non-verbal intellectual capacity of school-age children with CP and to examine the…

Job strain and older workers: Can a reduction in job strain help to eliminate the social security drain?

PubMed

Cahalin, Lawrence P

2009-01-01

Job strain is the psychological and physiological response to a lack of control or support in the work environment. It appears to be an important risk factor for continued employment throughout the lifespan. Reducing job strain earlier in a workers life has the potential to have substantial beneficial health effects throughout a workers life. Early screening for job strain should be implemented in known high risk or high strain jobs. This is particularly important since there a fewer younger workers entering the labor force and there will be a growing need for older workers to remain in the workforce. Furthermore, healthier workers will require less medical care and are likely to work longer if they are willing and able. Healthier older workers who are willing and able to work longer will defer receipt of retirement benefits while continuing to pay into the Social Security System. Further investigation of older individuals (1) willingness and motivation to work past the normal retirement age, (2) career and employment security, skills development, and reconciliation of working and non-working life, and (3) job strain and effects of reducing job strain is needed. The current job strain literature has been expanded to the Social Security System arena and suggests that reducing job strain has the potential to help eliminate the Social Security drain by increasing older worker labor force retention.

Smoking and Early COPD as Independent Predictors of Body Composition, Exercise Capacity, and Health Status.

PubMed

Caram, Laura Miranda de Oliveira; Ferrari, Renata; Bertani, André Luís; Garcia, Thaís; Mesquita, Carolina Bonfanti; Knaut, Caroline; Tanni, Suzana Erico; Godoy, Irma

2016-01-01

The effects of tobacco smoke, mild/moderate COPD disease and their combined effect on health status (HS), body composition (BC), and exercise capacity (EC) impairment are still unclear. We hypothesized that smoking and early COPD have a joint negative influence on these outcomes. We evaluated 32 smokers (smoking history >10 pack/years), 32 mild/moderate COPD (current smokers or former smokers), and 32 never smokers. All individuals underwent medical and smoking status evaluations, pre and post-bronchodilator spirometry, BC [fat-free mass (FFM) and FFM index (FFMI)], EC [six-minute walk distance (6MWD)] and HS [Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36)]. FFM (p = 0.02) and FFMI (p = 0.008) were lower in COPD than never smokers. 6MWT, as a percentage of reference values for the Brazilian population, was lower in COPD and smokers than never smokers (p = 0.01). Smokers showed worse SF-36 score for functional capacity than never smokers (p<0.001). SF-36 score for physical functioning (p<0.001) and role-emotional (p<0.001) were impaired in COPD patients than smokers. SF-36 scores for physical functioning (p<0.001), role-physical (p = 0.01), bodily pain (p = 0.01), vitality (p = 0.04) and role-emotional (p<0.001) were lower in COPD than never smokers. Multiple linear regression analysis showed that both COPD diagnosis and smoking were inversely associated with FFMI, 6MWD and HS. Smoking and early COPD have a joint negative influence on body composition, exercise capacity and health status.

Collapse of proteostasis represents an early molecular event in Caenorhabditis elegans aging.

PubMed

Ben-Zvi, Anat; Miller, Elizabeth A; Morimoto, Richard I

2009-09-01

Protein damage contributes prominently to cellular aging. To address whether this occurs at a specific period during aging or accumulates gradually, we monitored the biochemical, cellular, and physiological properties of folding sensors expressed in different tissues of C. elegans. We observed the age-dependent misfolding and loss of function of diverse proteins harboring temperature-sensitive missense mutations in all somatic tissues at the permissive condition. This widespread failure in proteostasis occurs rapidly at an early stage of adulthood, and coincides with a severely reduced activation of the cytoprotective heat shock response and the unfolded protein response. Enhancing stress responsive factors HSF-1 or DAF-16 suppresses misfolding of these metastable folding sensors and restores the ability of the cell to maintain a functional proteome. This suggests that a compromise in the regulation of proteostatic stress responses occurs early in adulthood and tips the balance between the load of damaged proteins and the proteostasis machinery. We propose that the collapse of proteostasis represents an early molecular event of aging that amplifies protein damage in age-associated diseases of protein conformation.

Postmortem aging and freezing and thawing storage enhance ability of early deboned chicken pectoralis major muscle to hold added salt water.

PubMed

Zhuang, H; Savage, E M

2012-05-01

The effects of postdeboning aging and frozen storage on water-holding capacity (WHC) of chicken breast pectoralis major muscle were investigated. Broiler breast muscle was removed from carcasses either early postmortem (2 h) or later postmortem (24 h). Treatments included: no postdeboning aging; 1-d postdeboning aging at 2°C, 7-d postdeboning aging (2-h deboned meat only), and 6-d storage at -20°C plus 1-d thawing at 2°C (freezing and thawing treatment, 2-h deboned meat only). The WHC was determined by cooking loss, drip loss, a filter paper press method (results were presented as expressible fluid), and a salt-induced swelling and centrifugation method (results were presented as percentage of salt-induced water gain). There were no differences for WHC estimated by cooking loss and expressible fluid between the treatments. Only the freezing and thawing treatment resulted in a significant increase in drip loss. The average percentage of salt-induced water gains by the 24-h deboned samples, postdeboning aged 2 h samples, and frozen 2 h sample, which did not differ from each other, were significantly higher than that by the 2-h deboned sample. These results indicate that regardless of method (carcass aging vs. postdeboning aging) and time (aging for 1 d vs. for 7 d), postmortem aging more than 1 d does not affect WHC of the early deboned samples measured by dripping, cooking, and pressing. However, postmortem carcass aging, postdeboning aging, and freezing and thawing storage can significantly enhance the ability of chicken breast meat to hold added salt water or WHC measured by the salt-induced swelling and centrifuge method.

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. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Early life determinants of frailty in old age: the Helsinki Birth Cohort Study.

PubMed

Haapanen, M J; Perälä, M M; Salonen, M K; Kajantie, E; Simonen, M; Pohjolainen, P; Eriksson, J G; von Bonsdorff, M B

2018-04-12

there is evidence suggesting that several chronic diseases have their origins in utero and that development taking place during sensitive periods may affect the aging process. We investigated whether early life determinants would be associated with frailty in old age. at a mean age of 71 years, 1,078 participants belonging to the Helsinki Birth Cohort Study were assessed for frailty according to the Fried frailty criteria. Early life measurements (birth weight, length, mother body mass index [BMI] and parity) were obtained from birth, child welfare and school health records. Multinomial regression analysis was used to assess the association between early life determinants and frailty in old age. weight, length and BMI at birth were all inversely associated with frailty in old age. A 1 kg increase in birth weight was associated with a lower relative risk ratio (RRR) of frailty (age and sex-adjusted RRR = 0.40, 95% CI: 0.19, 0.82) compared to non-frailty. Associations persisted after adjusting for several confounding factors. Compared to cohort members in the upper middle class, those who as adults worked as manual workers or belonged to the lower middle class, were at an increased risk of frailty. those who were small at birth were at an increased risk of developing frailty in old age, suggesting that frailty is at least partly programmed in early life. A less privileged socioeconomic status in adulthood was associated with an increased risk of frailty in old age.

Age-related changes in fear, sociality and pecking behaviours in two strains of laying hen.

PubMed

Hocking, P M; Channing, C E; Waddington, D; Jones, R B

2001-09-01

1. Two lines of commercial hybrid layers (Tetra and ISA Brown) were reared from hatch to 30 weeks of age in groups of 8. The objectives of the experiment were to evaluate the significance of the different selection practices involved in the development of the lines and to assess the potential association between selected behavioural states and the potential for feather damage and cannibalism. 2. Behavioural tests related to fear (tonic immobility, novel object, open field), sociality (runway, proximity in the home pen) and pecking (feather bunch and focal observations of inter-bird and environmental pecking) were conducted at 0 to 2, 5 to 7, 12 to 14, 19 to 21 and 29 to 31 weeks of age. Scan sampling of general behaviour was also conducted at these ages. 3. Underlying sociality was greater in Tetras than in ISA Brown hens. 4. There were no apparent overall strain differences in fearfulness although ISA Brown hens showed significantly longer tonic immobility fear reactions than Tetras at 31 weeks of age. 5. ISA Brown hens gave and received more gentle pecks than Tetra hens whereas preening was commoner among Tetras. There were no strain differences in the number of pecks at litter or food. 6. As birds aged they showed less avoidance of novel objects and Tetras, though not ISA Browns, showed progressively shorter tonic immobility responses. Birds of both strains spent less time resting, more foraging (pecking and scratching) and pecked more at the feather bunch at older ages. 7. Measures taken in the TI, open field, runway (social affiliation) and feather bunch tests were stable over time whereas focal observations of pecking at hens and the environment were not. 8. Factor Analysis showed that 3 factors defined by the novel object test, environmental pecking and pecking ata feather bunch explained most of the variation in the correlation matrix between summary measures for the 8 behavioural traits.

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.

Normative shifts of cortical mechanisms of encoding contribute to adult age differences in visual-spatial working memory.

PubMed

Störmer, Viola S; Li, Shu-Chen; Heekeren, Hauke R; Lindenberger, Ulman

2013-06-01

The capacity of visual-spatial working memory (WM) declines from early to late adulthood. Recent attempts at identifying neural correlates of WM capacity decline have focused on the maintenance phase of WM. Here, we investigate neural mechanisms during the encoding phase as another potential mechanism contributing to adult age differences in WM capacity. We used electroencephalography to track neural activity during encoding and maintenance on a millisecond timescale in 35 younger and 35 older adults performing a visual-spatial WM task. As predicted, we observed pronounced age differences in ERP indicators of WM encoding: Younger adults showed attentional selection during item encoding (N2pc component), but this selection mechanism was greatly attenuated in older adults. Conversely, older adults showed more pronounced signs of early perceptual stimulus processing (N1 component) than younger adults. The amplitude modulation of the N1 component predicted WM capacity in older adults, whereas the attentional amplitude modulation of the N2pc component predicted WM capacity in younger adults. Our findings suggest that adult age differences in mechanisms of WM encoding contribute to adult age differences in limits of visual-spatial WM capacity. Copyright © 2013 Elsevier Inc. All rights reserved.

Boosting Early Development: The Mixed Effects of Kindergarten Enrollment Age

ERIC Educational Resources Information Center

Zhang, Jiahui; Xin, Tao

2012-01-01

This study aimed to investigate the effects of kindergarten enrollment age on four-year-old Chinese children's early cognition and problem behavior using multilevel models. The sample comprised of 1,391 pre-school children (the mean age is 4.58 years old) from 74 kindergartens in six different provinces. The results demonstrated curvilinear…

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

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.

Acoustic Emission Behavior of Early Age Concrete Monitored by Embedded Sensors.

PubMed

Qin, Lei; Ren, Hong-Wei; Dong, Bi-Qin; Xing, Feng

2014-10-02

Acoustic emission (AE) is capable of monitoring the cracking activities inside materials. In this study, embedded sensors were employed to monitor the AE behavior of early age concrete. Type 1-3 cement-based piezoelectric composites, which had lower mechanical quality factor and acoustic impedance, were fabricated and used to make sensors. Sensors made of the composites illustrated broadband frequency response. In a laboratory, the cracking of early age concrete was monitored to recognize different hydration stages. The sensors were also embedded in a mass concrete foundation to localize the temperature gradient cracks.

Vega interstage strain measurements: comparison between conventional strain gauges and fibre Bragg grating sensors

NASA Astrophysics Data System (ADS)

Cheng, Lun; Ahlers, Berit

2017-11-01

Europe is developing a new generation launcher, called Vega, a small launcher with a capacity to place satellites into polar and low-Earth orbits, which are used for many scientific and Earth observation missions. Its first launch is scheduled for early 2008. Dutch Space is responsible for the development, qualification and manufacturing of the Vega Interstage 1/2. This all-aluminium conically shaped section is designed as a monocoque structure. This subsystem of Vega has undergone its first qualification tests of force loading combined with an extensive programme of measurements (forces, displacements and strains), at TNO in Delft. In parallel to conventional strain gauges Fibre Optic Sensors (FOS) in the form of Fibre Bragg Grating (FBG) sensor arrays, consisting of five strain sensors and one temperature sensor, have been installed on different locations of the interstage. Direct comparisons of the results with conventional sensors during load tests up to several hundred tons are therefore possible. A self-evident benefit of FBG sensors in an array application is that each sensing FBG can have a different Bragg wavelength to reflect. Thus, Wavelength Division Multiplexing (WDM) can conveniently be used to distinguish the different sensing FBG's at the receiving side. First test results from load measurements performed on the Qualification Model (QM) of the Vega Interstage 1/2 are presented in this paper as well as an outlook to future integration of the FBG in this field.

The capacity to generate alternative ideas is more important than inhibition for logical reasoning in preschool-age children.

PubMed

de Chantal, Pier-Luc; Markovits, Henry

2017-02-01

There is little consensus about the nature of logical reasoning and, equally important, about how it develops. To address this, we looked at the early origins of deductive reasoning in preschool children. We examined the contribution of two factors to the reasoning ability of very young children: inhibitory capacity and the capacity to generate alternative ideas. In a first study, a total of 32 preschool children were all given generation, inhibition, and logical reasoning measures. Logical reasoning was measured using knowledge-based premises such as "All dogs have legs," and two different inferences: modus ponens and affirmation of the consequent. Results revealed that correctly reasoning with both inferences is not related to the measure of inhibition, but is rather related to the capacity to generate alternative ideas. In a second study, 32 preschool children were given either the generation or the inhibition task before the logical reasoning measure. Results showed that receiving the generation task beforehand significantly improved logical reasoning compared to the inhibition task given beforehand. Overall, these results provide evidence for the greater importance of idea generation in the early development of logical reasoning.

Enhanced strain effect of aged acceptor-doped BaTiO3 ceramics with clamping domain structures

NASA Astrophysics Data System (ADS)

Wang, Lei; Zhou, Zhiyong; Zhao, Xiaobo; Liu, Zhen; Liang, Ruihong; Dong, Xianlin

2017-03-01

A clamping domain structure is proposed to improve the amount of non-180° domain switching in BaTiO3 based piezoelectric ceramics. Experimental results show a large unipolar strain of 0.23% at 5 kV/mm in aged 0.5 mol. % Mn doped BaTiO3 ceramics with clamping domain structures, and the normalized strain (d33*= Smax/Emax) reaches 600 pm/V at low electric fields of 2 or 3 kV/mm. In contrast, pure BaTiO3 ceramics with clamping domain structures exhibit no clear polarization constriction or strain enhancement at 3 kV/mm. Electron paramagnetic resonance spectra verify the existence of titanium vacancies, Mn2+ and Mn4+, in 0.5 mol. % Mn doped BaTiO3 ceramics. These results indicate that the enhanced strain effect can be attributed to the combined effect of the clamping domain structure and stabilization of defect dipoles. This method provides a general way to obtain large strain in ferroelectrics.

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.…

Estimation of salivary flow rate, pH, buffer capacity, calcium, total protein content and total antioxidant capacity in relation to dental caries severity, age and gender.

PubMed

Pandey, Pallavi; Reddy, N Venugopal; Rao, V Arun Prasad; Saxena, Aditya; Chaudhary, C P

2015-03-01

The aim of the study was to evaluate salivary flow rate, pH, buffering capacity, calcium, total protein content and total antioxidant capacity in relation to dental caries, age and gender. The study population consisted of 120 healthy children aged 7-15 years that was further divided into two groups: 7-10 years and 11-15 years. In this 60 children with DMFS/dfs = 0 and 60 children with DMFS/dfs ≥5 were included. The subjects were divided into two groups; Group A: Children with DMFS/dfs = 0 (caries-free) Group B: Children with DMFS/dfs ≥5 (caries active). Unstimulated saliva samples were collected from all groups. Flow rates were determined, and samples analyzed for pH, buffer capacity, calcium, total protein and total antioxidant status. Salivary antioxidant activity is measured with spectrophotometer by an adaptation of 2,2'-azino-di-(3-ethylbenzthiazoline-6-sulphonate) assays. The mean difference of the two groups; caries-free and caries active were proved to be statistically significant (P < 0.05) for salivary calcium, total protein and total antioxidant level for both the sexes in the age group 7-10 years and for the age 11-15 years the mean difference of the two groups were proved to be statistically significant (P < 0.05) for salivary calcium level for both the sexes. Salivary total protein and total antioxidant level were proved to be statistically significant for male children only. In general, total protein and total antioxidants in saliva were increased with caries activity. Calcium content of saliva was found to be more in caries-free group and increased with age.

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,…

Early growth patterns are associated with intelligence quotient scores in children born small-for-gestational age.

PubMed

Varella, Marcia H; Moss, William J

2015-08-01

To assess whether patterns of growth trajectory during infancy are associated with intelligence quotient (IQ) scores at 4 years of age in children born small-for-gestational age (SGA). Children in the Collaborative Perinatal Project born SGA were eligible for analysis. The primary outcome was the Stanford-Binet IQ score at 4 years of age. Growth patterns were defined based on changes in weight-for-age z-scores from birth to 4 months and 4 to 12 months of age and consisted of steady, early catch-up, late catch-up, constant catch-up, early catch-down, late catch-down, constant catch-down, early catch-up & late catch-down, and early catch-down & late catch-up. Multivariate linear regression was used to assess associations between patterns of growth and IQ. We evaluated patterns of growth and IQ in 5640 children. Compared with children with steady growth, IQ scores were 2.9 [standard deviation (SD)=0.54], 1.5 (SD=0.63), and 2.2 (SD=0.9) higher in children with early catch-up, early catch-up and later catch-down, and constant catch-up growth patterns, respectively, and 4.4 (SD=1.4) and 3.9 (SD=1.5) lower in children with early catch-down & late catch-up, and early catch-down growth patterns, respectively. Patterns in weight gain before 4 months of age were associated with differences in IQ scores at 4 years of age, with children with early catch-up having slightly higher IQ scores than children with steady growth and children with early catch-down having slightly lower IQ scores. These findings have implications for early infant nutrition in children born SGA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Strain localisation in mechanically layered rocks beneath detachment zones: insights from numerical modelling

NASA Astrophysics Data System (ADS)

Le Pourhiet, L.; Huet, B.; Labrousse, L.; Yao, K.; Agard, P.; Jolivet, L.

2013-04-01

We have designed a series of fully dynamic numerical simulations aimed at assessing how the orientation of mechanical layering in rocks controls the orientation of shear bands and the depth of penetration of strain in the footwall of detachment zones. Two parametric studies are presented. In the first one, the influence of stratification orientation on the occurrence and mode of strain localisation is tested by varying initial dip of inherited layering in the footwall with regard to the orientation of simple shear applied at the rigid boundary simulating a rigid hanging wall, all scaling and rheological parameter kept constant. It appears that when Mohr-Coulomb plasticity is being used, shear bands are found to localise only when the layering is being stretched. This corresponds to early deformational stages for inital layering dipping in the same direction as the shear is applied, and to later stages for intial layering dipping towards the opposite direction of shear. In all the cases, localisation of the strain after only γ=1 requires plastic yielding to be activated in the strong layer. The second parametric study shows that results are length-scale independent and that orientation of shear bands is not sensitive to the viscosity contrast or the strain rate. However, decreasing or increasing strain rate is shown to reduce the capacity of the shear zone to localise strain. In the later case, the strain pattern resembles a mylonitic band but the rheology is shown to be effectively linear. Based on the results, a conceptual model for strain localisation under detachment faults is presented. In the early stages, strain localisation occurs at slow rates by viscous shear instabilities but as the layered media is exhumed, the temperature drops and the strong layers start yielding plastically, forming shear bands and localising strain at the top of the shear zone. Once strain localisation has occured, the deformation in the shear band becomes extremely penetrative but

Bioaccessible Antioxidants in Milk Fermented by Bifidobacterium longum subsp. longum Strains

PubMed Central

Gagnon, Mérilie; Savard, Patricia; Rivière, Audrey; LaPointe, Gisèle

2015-01-01

Bifidobacterium longum subsp. longum is among the dominant species of the human gastrointestinal microbiota and could thus have potential as probiotics. New targets such as antioxidant properties have interest for beneficial effects on health. The objective of this study was to evaluate the bioaccessibility of antioxidants in milk fermented by selected B. longum subsp. longum strains during in vitro dynamic digestion. The antioxidant capacity of cell extracts from 38 strains, of which 32 belong to B. longum subsp. longum, was evaluated with the ORAC (oxygen radical absorbance capacity) method. On the basis of screening and gene sequence typing by multilocus locus sequence analysis (MLSA), five strains were chosen for fermenting reconstituted skim milk. Antioxidant capacity varied among the strains tested (P = 0.0009). Two strains of B. longum subsp. longum (CUETM 172 and 171) showed significantly higher ORAC values than the other bifidobacteria strains. However, there does not appear to be a relationship between gene sequence types and antioxidant capacity. The milk fermented by each of the five strains selected (CUETM 268, 172, 245, 247, or PRO 16-10) did not have higher initial ORAC values compared to the nonfermented milk samples. However, higher bioaccessibility of antioxidants in fermented milk (175–358%) was observed during digestion. PMID:25802836

Evaluation of the attentional capacities and working memory of early and late blind persons.

PubMed

Pigeon, Caroline; Marin-Lamellet, Claude

2015-02-01

Although attentional processes and working memory seem to be significantly involved in the daily activities (particularly during navigating) of persons who are blind and who use these abilities to compensate for their lack of vision, few studies have investigated these mechanisms in this population. The aim of this study is to evaluate the selective, sustained and divided attention, attentional inhibition and switching and working memory of blind persons. Early blind, late blind and sighted participants completed neuropsychological tests that were designed or adapted to be achievable in the absence of vision. The results revealed that the early blind participants outperformed the sighted ones in selective, sustained and divided attention and working memory tests, and the late blind participants outperformed the sighted participants in selective, sustained and divided attention. However, no differences were found between the blind groups and the sighted group in the attentional inhibition and switching tests. Furthermore, no differences were found between the early and late blind participants in this set of tests. These results suggest that early and late blind persons can compensate for the lack of vision by an enhancement of the attentional and working memory capacities. Copyright © 2014 Elsevier B.V. All rights reserved.

The cell biology of aging.

PubMed

Hayflick, L

1985-02-01

It is only within the past ten years that biogerontology has become attractive to a sufficient number of biologists so that the field can be regarded as a seriously studied discipline. Cytogerontology, or the study of aging at the cellular level, had its genesis about 20 years ago when the dogma that maintained that cultured normal cells could replicate forever was overturned. Normal human and animal cells have a finite capacity to replicate and function whether they are cultured in vitro or transplanted as grafts in vivo. This phenomenon has been interpreted to be aging at the cellular level. Only abnormal somatic cells are capable of immortality. In recent years it has been found that the number of population doublings of which cultured normal cells are capable is inversely proportional to donor age. There is also good evidence that the number of population doublings of cultured normal fibroblasts is directly proportional to the maximum lifespan of ten species that have been studied. Cultures prepared from patients with accelerated aging syndromes (progeria and Werner's syndrome) undergo far fewer doublings than do those of age-matched controls. The normal human fibroblast cell strain WI-38 was established in 1962 from fetal lung, and several hundred ampules of these cells were frozen in liquid nitrogen at that time. These ampules have been reconstituted periodically and shown to be capable of replication. This represents the longest period of time that a normal human cell has ever been frozen. Normal human fetal cell strains such as WI-38 have the capacity to double only about 50 times. If cultures are frozen at various population doublings, the number of doublings remaining after reconstitution is equal to 50 minus the number of doublings that occurred prior to freezing. The memory of the cells has been found to be accurate after 23 years of preservation in liquid nitrogen. Normal human cells incur many physiologic decrements that herald the approach of their

Early embryonic survival and embryo development in two lines of rabbits divergently selected for uterine capacity.

PubMed

Peiró, R; Santacreu, M A; Climent, A; Blasco, A

2007-07-01

The aim of this work is to study early embryo survival and development in 2 lines divergently selected for high and low uterine capacity throughout 10 generations. A total of 162 female rabbits from the high line and 133 from the low line were slaughtered at 25, 48, or 62 h of gestation. There were no differences in ovulation rate and fertilization rate between lines in any of the 3 stages of gestation. Embryo survival, estimated as the number of normal embryos recovered at a constant ovulation rate, was similar in both lines at 25 and 48 h. Embryo survival was greater in the high line [D (posterior mean of the difference between the high and low lines) = 0.57 embryos] at 62 h of gestation. There was no difference in embryonic stage of development at 25 h, but at 48 and 62 h of gestation, the high line, compared with the low line, had a greater percentage of early morulae (83 vs. 72%) and compacted morulae (55 vs. 38%). Divergent selection for uterine capacity appeared to modify embryo development, at least from 48 h of gestation, and embryo survival from 62 h.

Early Childhood Predictors of School-Age Children's Reports of Sibling Relationships.

ERIC Educational Resources Information Center

Poris, Michelle P.

This study examined the associations between the early family environment, older siblings' early characteristics, and later sibling relationships. Participating were 37 families with infants and preschool-age older siblings who were observed in the laboratory at 3 time points and followed-up 3 years later. Findings indicated that parents' early…

School Age Outcomes of Children Diagnosed Early and Later with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Clark, Megan Louise Erin; Vinen, Zoe; Barbaro, Josephine; Dissanayake, Cheryl

2018-01-01

Early diagnosis of Autism Spectrum Disorder is considered best practice, increasing access to early intervention. Yet, many children are diagnosed after 3-years. The current study investigated the school age outcomes of children who received an early and later diagnosis of ASD. The cognitive and behavioural outcomes of children diagnosed early (n…

Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension.

PubMed

Henein, Michael; Mörner, Stellan; Lindmark, Krister; Lindqvist, Per

2013-09-30

Heart failure (HF) patients with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) due to systemic hypertension (SHT) are known to have limited exercise tolerance. Despite having normal EF at rest, we hypothesize that these patients have abnormal systolic function reserve limiting their exercise capacity. Seventeen patients with SHT (mean age 68 ± 9 years) but no valve disease and 14 healthy individuals (mean age of 65 ± 10 years) underwent resting and peak exercise echocardiography using conventional, tissue Doppler and speckle tracking techniques. The differences between resting and peak exercise values were also analyzed (Δ). Exercise capacity was determined as the workload divided by body surface area. Resting values for left atrial (LA) volume/BSA (r=-0.66, p<0.001) and global longitudinal strain rate (GLSR) in early (e) and late (a) diastole (r=0.47 and 0.46, p<0.05 for both) correlated with exercise capacity. LVEF increased during exercise in normals (mean Δ EF=10 ± 8%) but failed to do so in patients (mean Δ EF=0.6 ± 9%, p<0.001 between groups). LV GLSR during systole (s) also failed to increase with exercise in patients, to the same extent as it did in normals (0.2 ± 0.2 vs. 0.6 ± 0.3 1/s, p<0.001). The difference between rest and exercise (Δ) in LV lateral wall systolic velocity from tissue Doppler (s') (0.71, p<0.001), Δ in cardiac output (r=0.60, p<0.001) and Δ GLSRs (r=0.48, p<0.05) all correlated with exercise capacity independent of changes in heart rate. HFpEF patients with hypertensive LV disease have significantly limited exercise capacity which is related to left atrial enlargement as well as compromised LV systolic function at the time of the symptoms. The limited myocardial systolic function reserve seems to be underlying important explanation for their limited exercise capacity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

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

Recognition of battery aging variations for LiFePO4 batteries in 2nd use applications combining incremental capacity analysis and statistical approaches

NASA Astrophysics Data System (ADS)

Jiang, Yan; Jiang, Jiuchun; Zhang, Caiping; Zhang, Weige; Gao, Yang; Guo, Qipei

2017-08-01

To assess the economic benefits of battery reuse, the consistency and aging characteristics of a retired LiFePO4 battery pack are studied in this paper. The consistency of battery modules is analyzed from the perspective of the capacity and the internal resistance. Test results indicate that battery module parameter dispersion increases along with battery aging. However, battery modules with better capacity consistency doesn't ensure better resistance consistency. Then the aging characteristics of the battery pack are analyzed and the main results are as follow: (1) Weibull and normal distribution are feasible to fit the capacity and resistance distribution of battery modules respectively; (2) SOC imbalance is the dominating factor in the capacity fading process of the battery pack; (3) By employing the incremental capacity (IC) and IC peak area analysis, a consistency evaluation method representing the aging mechanism variations of the battery modules is proposed and then an accurate battery screening strategy is put forward. This study not only provides data support for evaluating economic benefits of retired batteries but also presents a method to recognize the battery aging variations, which is helpful for rapid evaluation and screening of retired batteries for 2nd use.

Vitamin D Status and Early Age-Related Macular Degeneration in Postmenopausal Women

PubMed Central

Millen, Amy E.; Voland, Rick; Sondel, Sherie A.; Parekh, Niyati; Horst, Ronald L.; Wallace, Robert B.; Hageman, Gregory S.; Chappell, Rick; Blodi, Barbara A.; Klein, Michael L.; Gehrs, Karen M.; Sarto, Gloria E.; Mares, Julie A.

2010-01-01

Objective The relationship between serum 25-hydroxyvitamin D (25(OH)D) concentrations (nmol/L) and the prevalence of early age-related macular degeneration (AMD) was investigated among participants of the Carotenoids in Age-Related Eye Disease Study. Methods Stereoscopic fundus photographs, taken from 2001–2004, assessed AMD status. Baseline (1994–1998) serum samples were available for 25(OH)D assays in 1,313 women with complete ocular and risk factor data. Odds ratios (ORs) and 95% confidence intervals (CIs) for early AMD (n=241), among 1,287 without advanced disease, were estimated with logistic regression and adjusted for age, smoking, iris pigmentation, family history of AMD, cardiovascular disease, diabetes, and hormone therapy use. Results In multivariate models, no significant relationship was observed between early AMD and 25(OH)D (OR for quintile 5 vs. 1=0.79, 95% CI=0.50–1.24; p for trend=0.47). A significant age interaction (p=0.0025) suggested selective mortality bias in women ≥75 years: serum 25(OH)D was associated with decreased odds of early AMD in women <75 years (n=968) and increased odds in women ≥75 years (n=319) (OR for quintile 5 vs. 1=0.52, 95% CI=0.29–0.91; p for trend=0.02 and 1.76, 95% CI=0.77–4.13; p for trend=0.05, respectively). Further adjustment for body mass index and recreational physical activity, predictors of 25(OH)D, attenuated the observed association in women <75 years. Additionally, among women <75 years, intake of vitamin D from foods and supplements was related to decreased odds of early AMD in multivariate models; no relationship was observed with self-reported time spent in direct sunlight. Conclusions High serum 25(OH)D concentrations may protect against early AMD in women <75 years. PMID:21482873

Effects of 8-Week Training on Aerobic Capacity and Swimming Performance of Boys Aged 12 Years

ERIC Educational Resources Information Center

Zarzeczny, Ryszard; Kuberski, Mariusz; Deska, Agnieszka; Zarzeczna, Dorota; Rydz, Katarzyna; Lewandowska, Anna; Balchanowski, Tomasz; Bosiacki, Janusz

2011-01-01

Study aim: To assess the effects of 8-week endurance training in swimming on work capacity of boys aged 12 years. Material and methods: The following groups of schoolboys aged 12 years were studied: untrained control (UC; n = 14) and those training swimming for two years. The latter ones were subjected to 8-week training in classical style (CS; n…

Age-related Decline in Case-Marker Processing and its Relation to Working Memory Capacity.

PubMed

Sung, Jee Eun

2017-09-01

Purposes of the current study were to investigate whether age-related decline emerged in a case-marker assignment task (CMAT) and to explore the relationship between working-memory (WM) capacity and case-marker processing. A total of 121 individuals participated in the study with 62 younger adults and 59 elderly adults. All were administered a CMAT that consisted of active and passive constructions with canonical and noncanonical word-order conditions. A composite measure of WM tasks served as an index of participants' WM capacity. The older group performed worse than the younger group, and the noncanonical word order elicited worse performance than the canonical condition. The older group demonstrated greater difficulty in case-marker processing under the canonical condition and passive construction. Regression results revealed that age, education, and sentence type were the best predictors to account for performance on the CMAT. The canonicity of word order and passive construction were critical factors related to decline in abilities in a case-marker assignment. The combination of age, education, and sentence type factors accounted for overall performance on case-marker processing. Results indicated the crucial necessity to find a cognitively and linguistically demanding condition that elicits aging effects most efficiently, considering language-specific syntactic features. © 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.

Comparative Analysis of Drosophila melanogaster Gut Microbiota with Respect to Host Strain, Sex, and Age.

PubMed

Han, Gangsik; Lee, Hyo Jung; Jeong, Sang Eun; Jeon, Che Ok; Hyun, Seogang

2017-07-01

Microbiota has a significant impact on the health of the host individual. The complexity of the interactions between mammalian hosts and their microbiota highlights the value of using Drosophila melanogaster as a model organism, because of its relatively simple microbial community and ease of physiological and genetic manipulation. However, highly variable and sometimes inconsistent results regarding the microbiota of D. melanogaster have been reported for host samples collected from different geographical locations; discrepancies that may be because of the inherent physiological conditions of the D. melanogaster host. Here, we conducted a comparative analysis of the gut microbiota of two D. melanogaster laboratory strains, w 1118 and Canton S, with respect to the sex and age of the host, by pyrosequencing of the 16S rRNA gene. In addition to the widespread and abundant commensal bacterial genera Lactobacillus and Acetobacter, we identified Enterococcus and Leuconostoc as major host-strain-specific bacterial genera. The relative proportions of these bacterial genera, and those of the species within each, were found to differ markedly with respect to strain, sex, and age of the host, even though host individuals were reared under the same nutritional conditions. By using various bioinformatic tools, we uncovered several characteristic features of microbiota corresponding to specific categories of the flies: host-sex-bias association of specific bacteria, age-dependent alteration of microbiota across host species and sex, and uniqueness of the microbiota of female w 1118 flies. Our results, thus, help to further our understanding of host-microbe interactions in the D. melanogaster model.

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…

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.

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

Characterization of systemic and pneumonic murine models of plague infection using a conditionally virulent strain.

PubMed

Mellado-Sanchez, Gabriela; Ramirez, Karina; Drachenberg, Cinthia B; Diaz-McNair, Jovita; Rodriguez, Ana L; Galen, James E; Nataro, James P; Pasetti, Marcela F

2013-03-01

Yersinia pestis causes bubonic and pneumonic plague in humans. The pneumonic infection is the most severe and invariably fatal if untreated. Because of its high virulence, ease of delivery and precedent of use in warfare, Y. pestis is considered as a potential bioterror agent. No licensed plague vaccine is currently available in the US. Laboratory research with virulent strains requires appropriate biocontainment (i.e., Biosafety Level 3 (BSL-3) for procedures that generate aerosol/droplets) and secure facilities that comply with federal select agent regulations. To assist in the identification of promising vaccine candidates during the early phases of development, we characterized mouse models of systemic and pneumonic plague infection using the Y. pestis strain EV76, an attenuated human vaccine strain that can be rendered virulent in mice under in vivo iron supplementation. Mice inoculated intranasally or intravenously with Y. pestis EV76 in the presence of iron developed a systemic and pneumonic plague infection that resulted in disease and lethality. Bacteria replicated and severely compromised the spleen, liver and lungs. Susceptibility was age dependent, with younger mice being more vulnerable to pneumonic infection. We used these models of infection to assess the protective capacity of newly developed Salmonella-based plague vaccines. The protective outcome varied depending on the route and dose of infection. Protection was associated with the induction of specific immunological effectors in systemic/mucosal compartments. The models of infection described could serve as safe and practical tools for identifying promising vaccine candidates that warrant further potency evaluation using fully virulent strains in BSL-3 settings. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of different aging techniques on the polysaccharide and phenolic composition and sensory characteristics of Syrah red wines fermented using different yeast strains.

PubMed

del Barrio-Galán, Rubén; Medel-Marabolí, Marcela; Peña-Neira, Álvaro

2015-07-15

The effect of high levels of the polysaccharide Saccharomyces cerevisiae yeast strain (HPS) and another conventional yeast strain (FERM) on the polysaccharide and phenolic composition of Syrah red wines during alcoholic fermentation and subsequent aging on lees, with or without oak wood chips, and on inactive dry yeast was investigated. The HPS yeast released higher amounts of polysaccharides during alcoholic fermentation than FERM yeast (485 g L(-1) and 403 g L(-1), respectively) and after the aging period (516 g L(-1) and 500 g L(-1), respectively). The different aging techniques increased the polysaccharide concentration; the concentration was dependent on the aging technique applied. The interaction of the polysaccharides with the phenolic compounds depended on the yeast strain, aging technique, aging period and compound analysed. The HPS wines exhibited better sensory characteristics than the FERM wines after alcoholic fermentation; however, during the aging period, it was difficult to determine which technique produced the best wine due to the interactions of aging technique, aging period and sensory attribute evaluated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of maternal separation, early handling, and gonadal sex on regional metabolic capacity of the preweanling rat brain

PubMed Central

Spivey, Jaclyn M.; Padilla, Eimeira; Shumake, Jason D.; Gonzalez-Lima, F.

2010-01-01

This is the first study to assess the effects of mother-infant separation on regional metabolic capacity in the preweanling rat brain. Mother-infant separation is generally known to be stressful for rat pups. Holtzman adolescent rats show a depressive-like behavioral phenotype after maternal separation during the preweanling period. However, information is lacking on the effects of maternal separation on the brains of rat pups. We addressed this issue by mapping the brains of preweanling Holtzman rat pups using cytochrome oxidase histochemistry, which reflects long-term changes in brain metabolic capacity, following two weeks of repeated, prolonged maternal separation, and compared this to both early handled and non-handled pups. Quantitative image analysis revealed that maternal separation reduced cytochrome oxidase activity in the medial prefrontal cortex and nucleus accumbens shell. Maternal separation reduced prefrontal cytochrome oxidase to a greater degree in female pups than in males. Early handling reduced cytochrome oxidase activity in the posterior parietal cortex, ventral tegmental area, and subiculum, but increased cytochrome oxidase activity in the lateral frontal cortex. The sex-dependent effects of early handling on cytochrome oxidase activity were limited to the medial prefrontal cortex. Regardless of separation group, females had greater cytochrome oxidase activity in the habenula and ventral tegmental area compared to males. These findings suggest that early life mother-infant separation results in dysfunction of prefrontal and mesolimbic regions in the preweanling rat brain that may contribute to behavioral changes later in life. PMID:20969837

Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae.

PubMed

Pecenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

2017-09-01

Selected beneficial Pseudomonas spp. strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation. A crucial role for auxin in this long-term (1week), long-distance plant-microbe interaction has been demonstrated. Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv. maculicola (Psm) and P. syringae pv. tomato DC3000 (Pst), as well as Agrobacterium tumefaciens (Atu) and Escherichia coli (Eco). Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain. Several Arabidopsis mutants with impaired responses to pathogens, impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed. Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria; root hair growth was stimulated and primary root growth was inhibited. Other plant- and soil-adapted bacteria induced similar root hair responses. The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2. The single immune pathways dependent on salicylic acid, jasmonic acid and PAD4 are not directly involved in root hair growth stimulation; however, in the mutual cross-talk with ethylene, they indirectly modify the extent of the stimulation of root hair growth. The Flg22 peptide does not initiate root hair stimulation as intact bacteria do, but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner. These early response phenomena are not associated with changes in auxin levels, as monitored with the pDR5::GUS auxin reporter. Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria. The root

Association of early- and adult-life socioeconomic circumstances with muscle strength in older age.

PubMed

Cheval, Boris; Boisgontier, Matthieu P; Orsholits, Dan; Sieber, Stefan; Guessous, Idris; Gabriel, Rainer; Stringhini, Silvia; Blane, David; van der Linden, Bernadette W A; Kliegel, Matthias; Burton-Jeangros, Claudine; Courvoisier, Delphine S; Cullati, Stéphane

2018-05-01

socioeconomic circumstances (SEC) during a person's lifespan influence a wide range of health outcomes. However, solid evidence of the association of early- and adult-life SEC with health trajectories in ageing is still lacking. This study assessed whether early-life SEC are associated with muscle strength in later life-a biomarker of health-and whether this relationship is caused by adult-life SEC and health behaviours. we used data from the Survey of Health Ageing and Retirement in Europe, a 12-year population-based cohort study with repeated measurement in six waves (2004-15) and retrospective collection of life-course data. Participants' grip strength was assessed by using a handheld dynamometer. Confounder-adjusted logistic mixed-effect models were used to examine the associations of early- and adult-life SEC with the risk of low muscle strength (LMS) in older age. a total of 24,179 participants (96,375 observations) aged 50-96 living in 14 European countries were included in the analyses. Risk of LMS was increased with disadvantaged relative to advantaged early-life SEC. The association between risk of LMS and disadvantaged early-life SEC gradually decreased when adjusting for adult-life SEC for both sexes and with unhealthy behaviours for women. After adjusting for these factors, all associations between risk of LMS and early-life SEC remained significant for women. early-life SEC are associated with muscle strength after adjusting for adult-life SEC and behavioural lifestyle factors, especially in women, which suggests that early life may represent a sensitive period for future health.

Assessment of Early Diastolic Strain-Velocity Temporal Relationships Using SPAMM-PAV (SPAtial Modulation of Magnetization with Polarity Alternating Velocity encoding)

PubMed Central

Zhang, Ziheng; Dione, Donald P.; Brown, Peter B.; Shapiro, Erik M.; Sinusas, Albert J.; Sampath, Smita

2011-01-01

A novel MR imaging technique, spatial modulation of magnetization with polarity alternating velocity encoding (SPAMM-PAV), is presented to simultaneously examine the left ventricular early diastolic temporal relationships between myocardial deformation and intra-cavity hemodynamics with a high temporal resolution of 14 ms. This approach is initially evaluated in a dynamic flow and tissue mimicking phantom. A comparison of regional longitudinal strains and intra-cavity pressure differences (integration of computed in-plane pressure gradients within a selected region) in relation to mitral valve inflow velocities is performed in eight normal volunteers. Our results demonstrate that apical regions have higher strain rates (0.145 ± 0.005 %/ms) during the acceleration period of rapid filling compared to mid-ventricular (0.114 ± 0.007 %/ms) and basal regions (0.088 ± 0.009 %/ms), and apical strain curves plateau at peak mitral inflow velocity. This pattern is reversed during the deceleration period, when the strain-rates in the basal regions are the highest (0.027 ± 0.003 %/ms) due to ongoing basal stretching. A positive base-to-apex gradient in peak pressure difference is observed during acceleration, followed by a negative base-to apex gradient during deceleration. These studies shed insight into the regional volumetric and pressure difference changes in the left ventricle during early diastolic filling. PMID:21630348

Field study of age-differentiated strain for assembly line workers in the automotive industry.

PubMed

Börner, Kerstin; Scherf, Christian; Leitner-Mai, Bianca; Spanner-Ulmer, Birgit

2012-01-01

A field study in an automotive supply industry company was conducted to explore age-differentiated strain of assembly line workers. Subjective and objective data from 23 female workers aged between 27 and 57 years were collected at the workplace belt buckle assembly during morning shifts. Subjects with medication or chronic diseases affecting heart rate and breath rate were excluded. For subjective data generation different questionnaires were used. Before the Work Ability Index and the Munich Chronotype Questionnaire were completed by the subjects. Short questionnaires (strain-ratings, NASA-TLX) directly at begin and end of the work were used for obtaining shift-related data. During the whole shift (6 a.m. - 2.45 p.m.) bodily functions were logged with a wireless chest strap. In addition, the motion of the hand-arm-system was recorded for 30 times, 3 minutes each after a fixed time-schedule. First results show that younger subjects need significant less time for assembly (mean = 14.940 s) compared to older subjects (mean = 17.040 s; t(472.026) = -9.278 , p < 0.01).

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. Copyright © 2014 Elsevier Inc. All rights reserved.

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…

The person's conception of the structures of developing intellect: early adolescence to middle age.

PubMed

Demetriou, A; Efklides, A

1989-08-01

According to experiential structuralism, thought abilities have six capacity spheres: experimental, propositional, quantitative, imaginal, qualitative, and metacognitive. The first five are applied to the environment. The metacognitive capacity is applied to the others, serving as the interface between reality and the cognitive system or between any of the other capacities. To test this postulate, 648 subjects aged 12 to 40 years, solved eight tasks that were addressed, in pairs, to the first four capacity spheres. One of the tasks in each pair tapped the first and the other the third formal level of the sphere. Having solved the tasks, the subjects were required to rate each pair of tasks in terms of similarity of operations, difficulty, and success of solution. Factor analysis of difficulty and success evaluation scores revealed the same capacity-specific factors as the analysis of performance scores. Factor analysis of similarity scores differentiated between same- and different-sphere pairs. Analysis of variance showed that difficulty and success evaluation scores preserved performance differences between the first and the third formal tasks. Cognitive level, age, socioeconomic status, and sex were related to the metacognitive measures in ways similar to their relations to performance measures. These findings were integrated into a model aimed at capturing real-time metacognitive functioning.

Lack of serotonin1B receptor expression leads to age-related motor dysfunction, early onset of brain molecular aging and reduced longevity.

PubMed

Sibille, E; Su, J; Leman, S; Le Guisquet, A M; Ibarguen-Vargas, Y; Joeyen-Waldorf, J; Glorioso, C; Tseng, G C; Pezzone, M; Hen, R; Belzung, C

2007-11-01

Normal aging of the brain differs from pathological conditions and is associated with increased risk for psychiatric and neurological disorders. In addition to its role in the etiology and treatment of mood disorders, altered serotonin (5-HT) signaling is considered a contributing factor to aging; however, no causative role has been identified in aging. We hypothesized that a deregulation of the 5-HT system would reveal its contribution to age-related processes and investigated behavioral and molecular changes throughout adult life in mice lacking the regulatory presynaptic 5-HT(1B) receptor (5-HT(1B)R), a candidate gene for 5-HT-mediated age-related functions. We show that the lack of 5-HT(1B)R (Htr1b(KO) mice) induced an early age-related motor decline and resulted in decreased longevity. Analysis of life-long transcriptome changes revealed an early and global shift of the gene expression signature of aging in the brain of Htr1b(KO) mice. Moreover, molecular changes reached an apparent maximum effect at 18-months in Htr1b(KO) mice, corresponding to the onset of early death in that group. A comparative analysis with our previous characterization of aging in the human brain revealed a phylogenetic conservation of age-effect from mice to humans, and confirmed the early onset of molecular aging in Htr1b(KO) mice. Potential mechanisms appear independent of known central mechanisms (Bdnf, inflammation), but may include interactions with previously identified age-related systems (IGF-1, sirtuins). In summary, our findings suggest that the onset of age-related events can be influenced by altered 5-HT function, thus identifying 5-HT as a modulator of brain aging, and suggesting age-related consequences to chronic manipulation of 5-HT.

Proteomic analysis of HDL from inbred mouse strains implicates APOE associated with HDL in reduced cholesterol efflux capacity via the ABCA1 pathway[S

PubMed Central

Pamir, Nathalie; Hutchins, Patrick; Ronsein, Graziella; Vaisar, Tomas; Reardon, Catherine A.; Getz, Godfrey S.; Lusis, Aldons J.; Heinecke, Jay W.

2016-01-01

Cholesterol efflux capacity associates strongly and negatively with the incidence and prevalence of human CVD. We investigated the relationships of HDL’s size and protein cargo with its cholesterol efflux capacity using APOB-depleted serum and HDLs isolated from five inbred mouse strains with different susceptibilities to atherosclerosis. Like humans, mouse HDL carried >70 proteins linked to lipid metabolism, the acute-phase response, proteinase inhibition, and the immune system. HDL’s content of specific proteins strongly correlated with its size and cholesterol efflux capacity, suggesting that its protein cargo regulates its function. Cholesterol efflux capacity with macrophages strongly and positively correlated with retinol binding protein 4 (RBP4) and PLTP, but not APOA1. In contrast, ABCA1-specific cholesterol efflux correlated strongly with HDL’s content of APOA1, APOC3, and APOD, but not RBP4 and PLTP. Unexpectedly, APOE had a strong negative correlation with ABCA1-specific cholesterol efflux capacity. Moreover, the ABCA1-specific cholesterol efflux capacity of HDL isolated from APOE-deficient mice was significantly greater than that of HDL from wild-type mice. Our observations demonstrate that the HDL-associated APOE regulates HDL’s ABCA1-specific cholesterol efflux capacity. These findings may be clinically relevant because HDL’s APOE content associates with CVD risk and ABCA1 deficiency promotes unregulated cholesterol accumulation in human macrophages. PMID:26673204

Early childhood predictors of age of initiation to use of cannabis: a birth prospective study.

PubMed

Hayatbakhsh, Reza; Williams, Gail M; Bor, William; Najman, Jake M

2013-05-01

Early age of cannabis use predicts subsequent illicit drug abuse and other psychosocial problems. Identification of factors associated with early cannabis use may contribute to the development of preventive interventions. This study aimed to examine the early life predictors of age of initiation to cannabis. Data were from Mater Hospital and University of Queensland Study of Pregnancy, a population-based prospective birth cohort study. Participants were a cohort of 3488 young adults who self-reported frequency and age of onset of cannabis use at the 21 year follow up. Of 3488 young adults, 48.9% (51.8% men and 46.4% women) reported having ever used cannabis. For those who had ever used cannabis, age of onset had mean and median of 15.8 and 16.0 years, respectively. In multivariate analysis child's gender, change in maternal marital status, quality of marital relationship, maternal cigarette smoking and alcohol consumption and maternal depression when the child was 5 years statistically significantly predicted age of initiation to cannabis use. The present study explores the impact of early childhood factors associated with age of onset of cannabis use. It is suggested that the family environment within which children are reared, including factors such as parents' marital circumstances, has a major influence on initiation to cannabis use in adolescence. Research is needed to disentangle the pathways of association between these early life factors and early initiation to use of cannabis. © 2012 Australasian Professional Society on Alcohol and other Drugs.

Effects of Age and Working Memory Capacity on Speech Recognition Performance in Noise Among Listeners With Normal Hearing.

PubMed

Gordon-Salant, Sandra; Cole, Stacey Samuels

2016-01-01

This study aimed to determine if younger and older listeners with normal hearing who differ on working memory span perform differently on speech recognition tests in noise. Older adults typically exhibit poorer speech recognition scores in noise than younger adults, which is attributed primarily to poorer hearing sensitivity and more limited working memory capacity in older than younger adults. Previous studies typically tested older listeners with poorer hearing sensitivity and shorter working memory spans than younger listeners, making it difficult to discern the importance of working memory capacity on speech recognition. This investigation controlled for hearing sensitivity and compared speech recognition performance in noise by younger and older listeners who were subdivided into high and low working memory groups. Performance patterns were compared for different speech materials to assess whether or not the effect of working memory capacity varies with the demands of the specific speech test. The authors hypothesized that (1) normal-hearing listeners with low working memory span would exhibit poorer speech recognition performance in noise than those with high working memory span; (2) older listeners with normal hearing would show poorer speech recognition scores than younger listeners with normal hearing, when the two age groups were matched for working memory span; and (3) an interaction between age and working memory would be observed for speech materials that provide contextual cues. Twenty-eight older (61 to 75 years) and 25 younger (18 to 25 years) normal-hearing listeners were assigned to groups based on age and working memory status. Northwestern University Auditory Test No. 6 words and Institute of Electrical and Electronics Engineers sentences were presented in noise using an adaptive procedure to measure the signal-to-noise ratio corresponding to 50% correct performance. Cognitive ability was evaluated with two tests of working memory (Listening

Dynamic strain aging behavior of 10Cr steel under low cycle fatigue at 650°C

NASA Astrophysics Data System (ADS)

Mishnev, Roman; Dudova, Nadezhda; Kaibyshev, Rustam

2017-12-01

The low cycle fatigue behavior of a 10Cr-2W-0.7Mo-3Co-NbV steel with 80 ppm of B additions was studied at elevated temperatures of 600 and 650°C. The steel after normalizing and tempering at 770°C was tested under fully reversed tension-compression loading with the total strain amplitude controlled from ±0.2 to ±1.0% at temperatures of 600 and 650°C. It was revealed that the steel exhibits a positive temperature dependence of both the cyclic strain hardening exponent n' and the cyclic strength coefficient K ' during cyclic loading at 650°C. It was suggested that dynamic strain aging causes fatigue resistance degradation through facilitating microcrack initiation.

Age effects on preattentive and early attentive auditory processing of redundant stimuli: is sensory gating affected by physiological aging?

PubMed

Gmehlin, Dennis; Kreisel, Stefan H; Bachmann, Silke; Weisbrod, Matthias; Thomas, Christine

2011-10-01

The frontal hypothesis of aging predicts an age-related decline in cognitive functions requiring inhibitory or attentional regulation. In Alzheimer's disease, preattentive gating out of redundant information is impaired. Our study aimed to examine changes associated with physiological aging in both pre- and early attentive inhibition of recurrent acoustic information. Using a passive double-click paradigm, we recorded mid-latency (P30-P50) and late-latency (N100 and P200) evoked potentials in healthy young (26 ± 5 years) and healthy elderly subjects (72 ± 5 years). Physiological aging did not affect auditory gating in amplitude measures. Both age groups exhibited clear inhibition in preattentive P50 and attention-modulated (N100) components, whereas P30 was not attenuated. Irrespective of age, the magnitude of inhibition differed significantly, being most pronounced for N100 gating. Inhibition of redundant information seems to be preserved with physiological aging. Early attentive N100 gating showed the maximum effect. Further studies are warranted to evaluate sensory gating as a suitable biomarker of underlying neurodegenerative disease.

Electronic and phononic modulation of MoS2 under biaxial strain

NASA Astrophysics Data System (ADS)

Moghadasi, A.; Roknabadi, M. R.; Ghorbani, S. R.; Modarresi, M.

2017-12-01

Dichalcogenides of transition metals are attractive material due to its unique properties. In this work, it has been investigated the electronic band structure, phonon spectrum and heat capacity of MoS2 under the applied tensile and compressive biaxial strain using the density functional theory. The Molybdenum disulfide under compressive (tensile) strain up to 6% (10%) has stable atomic structure without any negative frequency in the phonon dispersion curves. The tensile biaxial strain reduces the energy gap in the electronic band structure and the optical-acoustic gap in phonon dispersion curves. The tensile biaxial strain also increases the specific heat capacity. On the other hand, the compressive biaxial strain in this material increases phonon gap and reduces the heat capacity and the electronic band gap. The phonon softening/hardening is reported for tensile/compressive biaxial strain in MoS2. We report phonon hardening for out of plane ZA mode in the presence of both tensile and compressive strains. Results show that the linear variation of specific heat with strain (CV ∝ε) and square dependency of specific heat with the temperature (CV ∝T2) for low temperature regime. The results demonstrate that the applied biaxial strain tunes the electronic energy gap and modifies the phonon spectrum of MoS2.

Effects of strain and age on hepatic gene expression profiles in murine models of HFE-associated hereditary hemochromatosis.

PubMed

Lee, Seung-Min; Loguinov, Alexandre; Fleming, Robert E; Vulpe, Christopher D

2015-01-01

Hereditary hemochromatosis is an iron overload disorder most commonly caused by a defect in the HFE gene. While the genetic defect is highly prevalent, the majority of individuals do not develop clinically significant iron overload, suggesting the importance of genetic modifiers. Murine hfe knockout models have demonstrated that strain background has a strong effect on the severity of iron loading. We noted that hepatic iron loading in hfe-/- mice occurs primarily over the first postnatal weeks (loading phase) followed by a timeframe of relatively static iron concentrations (plateau phase). We thus evaluated the effects of background strain and of age on hepatic gene expression in Hfe knockout mice (hfe-/-). Hepatic gene expression profiles were examined using cDNA microarrays in 4- and 8-week-old hfe-/- and wild-type mice on two different genetic backgrounds, C57BL/6J (C57) and AKR/J (AKR). Genes differentially regulated in all hfe-/- mice groups, compared with wild-type mice, including those involved in cell survival, stress and damage responses and lipid metabolism. AKR strain-specific changes in lipid metabolism genes and C57 strain-specific changes in cell adhesion and extracellular matrix protein genes were detected in hfe-/- mice. Mouse strain and age are each significantly associated with hepatic gene expression profiles in hfe-/- mice. These affects may underlie or reflect differences in iron loading in these mice.

Serrated Flow and Dynamic Strain Aging in Fe-Mn-C TWIP Steel

NASA Astrophysics Data System (ADS)

Lan, Peng; Zhang, Jiaquan

2018-01-01

The tensile behavior, serrated flow, and dynamic strain aging of Fe-(20 to 24)Mn-(0.4 to 0.6)C twinning-induced plasticity (TWIP) steel have been investigated. A mathematical approach to analyze the DSA and PLC band parameters has been developed. For Fe-(20 to 24)Mn-(0.4 to 0.6)C TWIP steel with a theoretical ordering index (TOI) between 0.1 and 0.3, DSA can occur at the very beginning of plastic deformation and provide serrations during work hardening, while for TOI less than 0.1 the occurrence of DSA is delayed and twinning-dominant work hardening remains relatively smooth. The critical strain for the onset of DSA and PLC bands in Fe-Mn-C TWIP steels decreases as C content increases, while the numbers of serrations and bands increase. As Mn content increases, the critical strain for DSA and PLC band varies irregularly, but the numbers of serrations and bands increase. For Fe-(20 to 24)Mn-(0.4 to 0.6)C TWIP steel with grain size of about 10 to 20 μm, the twinning-induced work hardening rate is about 2.5 to 3.0 GPa, while the DSA-dominant hardening rate is about 2.0 GPa on average. With increasing engineering strain from 0.01 to 0.55 at an applied strain rate of 0.001s-1, the cycle time for PLC bands in Fe-Mn-C TWIP steel increases from 6.5 to 162 seconds, while the band velocity decreases from 4.5 to 0.5 mm s-1, and the band strain increases from 0.005 to 0.08. Increasing applied strain rate leads to a linear increase of band velocity despite composition differences. In addition, the influence of the Mn and C content on the tensile properties of Fe-Mn-C TWIP steel has been also studied. As C content increases, the yield strength and tensile strength of Fe-Mn-C TWIP steel increase, but the total elongation variation against C content is dependent on Mn content. As Mn content increases, the yield strength and tensile strength decrease, while the total elongation increases, despite C content. Taking both tensile properties and serrated flow behavior into

Experimental Techniques for Evaluating the Effects of Aging on Impact and High Strain Rate Properties of Triaxial Braided Composite Materials

NASA Technical Reports Server (NTRS)

Pereira, J. Michael; Roberts, Gary D.; Ruggeri, Charles R.; Gilat, Amos; Matrka, Thomas

2010-01-01

An experimental program is underway to measure the impact and high strain rate properties of triaxial braided composite materials and to quantify any degradation in properties as a result of thermal and hygroscopic aging typically encountered during service. Impact tests are being conducted on flat panels using a projectile designed to induce high rate deformation similar to that experienced in a jet engine fan case during a fan blade-out event. The tests are being conducted on as-fabricated panels and panels subjected to various numbers of aging cycles. High strain rate properties are being measured using a unique Hopkinson bar apparatus that has a larger diameter than conventional Hopkinson bars. This larger diameter is needed to measure representative material properties because of the large unit cell size of the materials examined in this work. In this paper the experimental techniques used for impact and high strain rate testing are described and some preliminary results are presented for both as-fabricated and aged composites.

Signed language working memory capacity of signed language interpreters and deaf signers.

PubMed

Wang, Jihong; Napier, Jemina

2013-04-01

This study investigated the effects of hearing status and age of signed language acquisition on signed language working memory capacity. Professional Auslan (Australian sign language)/English interpreters (hearing native signers and hearing nonnative signers) and deaf Auslan signers (deaf native signers and deaf nonnative signers) completed an Auslan working memory (WM) span task. The results revealed that the hearing signers (i.e., the professional interpreters) significantly outperformed the deaf signers on the Auslan WM span task. However, the results showed no significant differences between the native signers and the nonnative signers in their Auslan working memory capacity. Furthermore, there was no significant interaction between hearing status and age of signed language acquisition. Additionally, the study found no significant differences between the deaf native signers (adults) and the deaf nonnative signers (adults) in their Auslan working memory capacity. The findings are discussed in relation to the participants' memory strategies and their early language experience. The findings present challenges for WM theories.

The effect of aging and cardiorespiratory fitness on the lung diffusing capacity response to exercise in healthy humans.

PubMed

Coffman, Kirsten E; Carlson, Alex R; Miller, Andrew D; Johnson, Bruce D; Taylor, Bryan J

2017-06-01

Aging is associated with deterioration in the structure and function of the pulmonary circulation. We characterized the lung diffusing capacity for carbon monoxide (DL CO ), alveolar-capillary membrane conductance (Dm CO ), and pulmonary-capillary blood volume (Vc) response to discontinuous incremental exercise at 25, 50, 75, and 90% of peak work (W peak ) in four groups: 1 ) Young [27 ± 3 yr, maximal oxygen consumption (V̇o 2max ): 110 ± 18% age predicted]; 2) Young Highly Fit (27 ± 3 yr, V̇o 2max : 147 ± 8% age predicted); 3 ) Old (69 ± 5 yr, V̇o 2max : 116 ± 13% age predicted); and 4 ) Old Highly Fit (65 ± 5 yr, V̇o 2max : 162 ± 18% age predicted). At rest and at 90% W peak , DL CO , Dm CO , and Vc were decreased with age. At 90% W peak , DL CO , Dm CO , and Vc were greater in Old Highly Fit vs. Old adults. The slope of the DL CO -cardiac output (Q̇) relationship from rest to end exercise at 90% W peak was not different between Young, Young Highly Fit, Old, and Old Highly Fit (1.35 vs. 1.44 vs. 1.10 vs. 1.35 ml CO ·mmHg -1 ·liter blood -1 , P = 0.388), with no evidence of a plateau in this relationship during exercise; this was also true for Dm CO -Q̇ and Vc-Q̇. V̇o 2max was positively correlated with 1 ) DL CO , Dm CO , and Vc at rest; and 2 ) the rest to end exercise change in DL CO , Dm CO , and Vc. In conclusion, these data suggest that despite the age-associated deterioration in the structure and function of the pulmonary circulation, expansion of the pulmonary capillary network does not become limited during exercise in healthy individuals regardless of age or cardiorespiratory fitness level. NEW & NOTEWORTHY Healthy aging is a crucial area of research. This article details how differences in age and cardiorespiratory fitness level affect lung diffusing capacity, particularly during high-intensity exercise. We conclude that highly fit older adults do not experience a limit in lung diffusing capacity during

Risk Factors in Preschool Children for Predicting Asthma During the Preschool Age and the Early School Age: a Systematic Review and Meta-Analysis.

PubMed

Bao, Yixia; Chen, Zhimin; Liu, Enmei; Xiang, Li; Zhao, Deyu; Hong, Jianguo

2017-11-18

The aim of this study was to identify risk factors of asthma among children < 6 years old (preschool age) for predicting asthma during the preschool age and early school age (≤ 10 years of age). MEDLINE, Cochrane, EMBASE, and Google Scholar databases were searched until June 30, 2017. Prospective or retrospective cohort and case-control studies were included. Studies had to have evaluated risk factors or a predictive model for developing asthma in children ≤ 6 years of age or persistent asthma in early school age. A total of 17 studies were included in the analysis. Factors associated with developing asthma in children ≤ 10 years of age (both pre-school and early school age) included male gender (pooled OR = 1.70, P < 0.001), atopic dermatitis (pooled OR = 2.02, P < 0.001), a family history of asthma (pooled OR = 2.20, P < 0.001), and serum IgE levels ≥ 60 kU/l or having specific IgE (pooled OR = 2.36, P < 0.001). A history of exposure to smoke or wheezing was also associated with persistent asthma in early school age (pooled OR = 1.51, P = 0.030 and pooled OR = 2.59, P < 0.001, respectively). In general, asthma predictive models (e.g., API, PIAMA, PAPS) had relatively low sensitivity (range, 21% to 71.4%) but high specificity (range, 69% to 98%). The study found that male gender, exposure to smoke, atopic dermatitis, family history of asthma, history of wheezing, and serum IgE level ≥ 60 kU/l or having specific IgE were significantly associated with developing asthma by either preschool or early school age. Asthma predictive models can be developed by those risk factors.

Study on Dynamic Strain Aging and Low-Cycle Fatigue of Stainless Steel in Ultra-Supercritical Unit

NASA Astrophysics Data System (ADS)

Hongwei, Zhou; Yizhu, He; Jizu, Lv; Sixian, Rao

Dynamic strain aging (DSA) and low-cycle fatigue (LCF) behavior of TP347H stainless steel in ultra-supercritical unit were investigated at 550-650 °C. All the LCF tests were carried out under a fully-reversed, total axial strain control mode at the total strain amplitude from ±0.2% to ±1.0%. The effects of DSA in cyclic stress response, microstructure evolution and fatigue fracture surfaces and fatigue life were investigated in detail. The results show that DSA occurs during tensile, which is manifested as serrated flow in tensile stress-strain curves. The apparent activation energy for appearing of serrations in tensile stress-strain curves was 270 kJ/mol. Pipe diffusion of substitutional solutes such as Cr and Nb along the dislocation core, and strong interactions between segregated solutes and dislocations are considered as the mechanism of DSA. DSA partly restricts dislocation cross-slip, and dislocation cross-slip and planar-slip happen simultaneously during LCF. A lot of planar structures form, which is due to dislocation gliding on the special plane. This localized deformation structures result in many crack initiation sites. Meanwhile, DSA hardening increases cyclic stress response, accelerating crack propagation, which reduces high temperature strain fatigue life of steel.

Effect of strain of layer and age at photostimulation on egg production, egg quality, and bone strength.

PubMed

Silversides, F G; Korver, D R; Budgell, K L

2006-07-01

Bone strength in layers is a concern for economic reasons and animal welfare concerns. Bone characteristics were investigated in 3 strains of hens: Babcock B-300, a small-bodied commercial white-egg layer; ISA-Brown, a commercial brown-egg layer; and an unselected Brown Leghorn line (BL). After being reared together in a single pen with 8 h of light per day, hens were caged with 14 h of light per day. Half of the hens were caged at 18 wk of age and the other half at 20 wk of age, resulting in a 2-wk difference in the age at photostimulation. Body weights, egg production, feed efficiency, and egg quality were measured throughout production. At 15, 25, 50, and 74 wk of age, hens were euthanized for sampling of the radius and the humerus. Breaking strength of the radius and humerus was measured, and the area and density of trabecular (largely medullary bone) and cortical bone were measured using quantitative computed tomography. Egg production and feed conversion of ISA-Brown hens was as good as or better than that of Babcock B-300 hens, and both commercial strains had higher production than the BL. Photostimulation late delayed sexual maturity and improved albumen and shell characteristics but had only minor effects on egg production and did not affect the yolk weight. The delayed photostimulation resulting from caging 2 wk later affected the radius by increasing the area of the trabecular space at 50 wk of age and the density of the bone in the trabecular space at 74 wk of age. Breaking strength of the humerus at 25 wk of age was greater for the birds that were photostimulated late but was not different later in the trial. The humerus, but not the radius, of the BL had a greater breaking strength than that of the commercial strains, suggesting that selection has decreased humeral breaking strength.

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

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.

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…

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…

Subtle abnormalities of gait detected early in vitamin B6 deficiency in aged and weanling rats with hind leg gait analysis.

PubMed

Schaeffer, M C; Cochary, E F; Sadowski, J A

1990-04-01

Motor abnormalities have been observed in every species made vitamin B6 deficient, and have been detected and quantified early in vitamin B6 deficiency in young adult female Long-Evans rats with hind leg gait analysis. Our objective was to determine if hind leg gait analysis could be used to detect vitamin B6 deficiency in weanling (3 weeks) and aged (23 months) Fischer 344 male rats. Rats (n = 10 per group) were fed: the control diet ad libitum (AL-CON); the control diet devoid of added pyridoxine hydrochloride (DEF); or the control diet pair-fed to DEF (PF-CON). At 10 weeks, plasma pyridoxal phosphate concentration confirmed deficiency in both age groups. Gait abnormalities were detected in the absence of gross motor disturbances in both aged and weanling DEF rats at 2-3 weeks. Width of step was significantly reduced (16%, p less than 0.003) in DEF aged rats compared to AL- and PF-CON. This pattern of response was similar to that reported previously in young adult rats. In weanling rats, pair feeding alone reduced mean width of step (+/- SEM) by 25% compared to ad libitum feeding (2.7 +/- 0.1 vs 3.6 +/- 0.1 cm for PF- vs AL-CON, respectively, p less than 0.05). In DEF weanling rats, width (3.0 +/- 0.1 cm) was increased compared to PF-CON (11%, p less than 0.05) but decreased compared to AL-CON (16%, p less than 0.05). Width of step was significantly altered early in B6 deficiency in rats of different ages and strains and in both sexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Conditional Deletion of the Pten Gene in the Mouse Prostate Induces Prostatic Intraepithelial Neoplasms at Early Ages but a Slow Progression to Prostate Tumors

PubMed Central

Zhu, Chunfang; Lee, Suk Hyung; Ye, Ding-Wei; Luong, Richard; Sun, Zijie

2013-01-01

The PTEN tumor suppressor gene is frequently inactivated in human prostate cancer. Using Osr1 (odd skipped related 1)-Cre mice, we generated a novel conditional Pten knockout mouse strain, PtenLoxP:Osr1-Cre. Conditional biallelic and monoallelic Pten knockout mice were viable. Deletion of Pten expression was detected in the prostate of PtenLoxP/LoxP:Osr1-Cre mice as early as 2 weeks of age. Intriguingly, PtenLoxP/LoxP:Osr1-Cre mice develop high-grade prostatic intraepithelial neoplasms (PINs) with high penetrance as early as one-month of age, and locally invasive prostatic tumors after 12-months of age. PtenLoxP/+:Osr1-Cre mice show only mild oncogenic changes after 8-weeks of age. Castration of PtenLoxP/LoxP:Osr1-Cre mice shows no significant regression of prostate tumors, although a shift of androgen receptor (AR) staining from the nuclei to cytoplasm is observed in Pten null tumor cells of castrated mice. Enhanced Akt activity is observed in Pten null tumor cells of castrated PtenLoxP/LoxP:Osr1-Cre. This study provides a novel mouse model that can be used to investigate a primary role of Pten in initiating oncogenic transformation in the prostate and to examine other genetic and epigenetic changes that are required for tumor progression in the mouse prostate. PMID:23308230

Turn and Face the Strain: Age Demographic Change and the near Future of American Education

ERIC Educational Resources Information Center

Ladner, Matthew

2015-01-01

"Turn and Face the Strain: Age Demographic Change and the Near Future of American Education" outlines a fierce battle looming between the needs of public health care and education. A crisis is fast approaching that makes comprehensive improvement of America's public schools more important than ever. Faced with rapidly expanding…

Early Education: The Creation of Capacity.

ERIC Educational Resources Information Center

Tumin, Melvin

Every human being is always open to some degree; for example, open for learning, experience, change, improvement, or further degradation by his own standards or those of others. Every experience alters an individual's learning capacity. Therefore, to say a child is naturally of high or low intelligence with unlimited or limited learning power is…

Release of nitrogen compounds to the extracellular medium by three strains of Saccharomyces cerevisiae during induced autolysis in a model wine system.

PubMed

Martínez-Rodriguez, A J; Carrascosa, A V; Polo, M C

2001-08-15

To detect differences among three strains of Saccharomyces cerevisiae used in the manufacture of sparkling wines and to study the changes in nitrogen compounds during autolysis, a model wine system was used. Significant differences were observed between the mean values of the autolytic capacity of the three strains. The amount of nitrogen (total, protein, peptide and amino) present in the autolysates and the concentration of most free amino acids was significantly affected by the strain. These findings suggest that the strain of yeast used in the manufacture of sparkling wines can play an important role in the aging process and can affect final composition.

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…

Mitigation strategies for early-age shrinkage cracking in bridge decks.

DOT National Transportation Integrated Search

2010-04-01

Early-age shrinkage cracking has been observed in many concrete bridge decks in Washington State and elsewhere around the U.S. The cracking increases the effects of freeze-thaw damage, spalling, and corrosion of steel reinforcement, thus resulting in...

Salivary pH and buffering capacity in early and late human immunodeficiency virus infection.

PubMed

Hegde, Mithra N; Malhotra, Amit; Hegde, Nidarsh D

2013-11-01

Human immunodeficiency virus (HIV) causes severe immunosuppression due to progressive decrease in the CD4 T lymphocyte cells during the course of the disease and this affects all the body systems including glandular secretions. A number of lesions affecting the salivary glands have been noted in HIV infection. The objective of this study was to evaluate the salivary pH and the buffering capacity in HIV positive individuals and comparing it with the HIV negative healthy individuals. The study was carried out on 200 HIV positive subjects aged 20-40 years, divided into two groups on the basis of CD4 count and 100 HIV negative healthy individuals as control group. Both unstimulated and stimulated saliva were collected and the pH and buffering capacity ascertained using the saliva check kit. (GC Asia Dental Pvt. Ltd., Singapore, 508724). All the three groups were compared using the ANOVA and it was found there was highly significant decrease in pH and buffering capacity with increase in immunosuppression. The intergroup comparison was carried out using the Tukey honestly significant difference (HSD) and the Chi square test. Group 1; CD4 count <200 and Group 2, CD4 count >200 showed a significant decrease in unstimulated salivary flow, stimulated salivary flow, and pH in comparison to HIV negative individuals; however, change in buffering capacity in Group 2 was not significant. There is a decrease in pH and buffering capacity in HIV infected patients. This decrease may be one of the factors responsible for increased caries in HIV infected population.

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.

Reduction in the retinotopic early visual cortex with normal aging and magnitude of perceptual learning.

PubMed

Chang, Li-Hung; Yotsumoto, Yuko; Salat, David H; Andersen, George J; Watanabe, Takeo; Sasaki, Yuka

2015-01-01

Although normal aging is known to reduce cortical structures globally, the effects of aging on local structures and functions of early visual cortex are less understood. Here, using standard retinotopic mapping and magnetic resonance imaging morphologic analyses, we investigated whether aging affects areal size of the early visual cortex, which were retinotopically localized, and whether those morphologic measures were associated with individual performance on visual perceptual learning. First, significant age-associated reduction was found in the areal size of V1, V2, and V3. Second, individual ability of visual perceptual learning was significantly correlated with areal size of V3 in older adults. These results demonstrate that aging changes local structures of the early visual cortex, and the degree of change may be associated with individual visual plasticity. Copyright © 2015 Elsevier Inc. All rights reserved.

Normal aging delays and compromises early multifocal visual attention during object tracking.

PubMed

Störmer, Viola S; Li, Shu-Chen; Heekeren, Hauke R; Lindenberger, Ulman

2013-02-01

Declines in selective attention are one of the sources contributing to age-related impairments in a broad range of cognitive functions. Most previous research on mechanisms underlying older adults' selection deficits has studied the deployment of visual attention to static objects and features. Here we investigate neural correlates of age-related differences in spatial attention to multiple objects as they move. We used a multiple object tracking task, in which younger and older adults were asked to keep track of moving target objects that moved randomly in the visual field among irrelevant distractor objects. By recording the brain's electrophysiological responses during the tracking period, we were able to delineate neural processing for targets and distractors at early stages of visual processing (~100-300 msec). Older adults showed less selective attentional modulation in the early phase of the visual P1 component (100-125 msec) than younger adults, indicating that early selection is compromised in old age. However, with a 25-msec delay relative to younger adults, older adults showed distinct processing of targets (125-150 msec), that is, a delayed yet intact attentional modulation. The magnitude of this delayed attentional modulation was related to tracking performance in older adults. The amplitude of the N1 component (175-210 msec) was smaller in older adults than in younger adults, and the target amplification effect of this component was also smaller in older relative to younger adults. Overall, these results indicate that normal aging affects the efficiency and timing of early visual processing during multiple object tracking.

No correlation is found for vegetables between antioxidant capacity and potential benefits in improving antioxidant function in aged rats

PubMed Central

Ji, Linlin; Gao, Weina; Wei, Jingyu; Wu, Jianquan; Yang, Jijun; Meng, Bin; Guo, Changjiang

2014-01-01

Vegetables vary greatly in antioxidant capacity in vitro. This study was to investigate the actions of three vegetables different remarkably in antioxidant capacity in vitro on antioxidant function in aged rats. Sixty female aged Wistar rats were randomly assigned to the control, lotus root, rape and cucumber (high, moderate and low in antioxidant capacity, respectively) treated groups. After 6 weeks of feeding, there were no significant differences in plasma FRAP value and contents of vitamin C, vitamin E, uric acid and total phenolics among different groups, whereas the content of reduced glutathione was significantly higher in the rape and cucumber groups. Plasma superoxide dismutase activity also was significantly increased in the rape and cucumber groups. Plasma contents of malondialdehyde, carbonyls and hemolysis were decreased significantly in 3 vegetable-treated groups. Meanwhile, urinary 8-hydroxy-2'-deoxyguanosine excretion was lower significantly in the rape group and the ratio of comet tail length to total length of blood mononuclear cells was decreased significantly in 3 vegetables treated groups. These results suggest that 3 vegetables tested are effective in improving antioxidant function to some extent in aged rats and no correlation is found between antioxidant capacity in vitro and improvements of antioxidant function. The benefits observed in this study may come from additive or synergistic combinations of antioxidants contained in vegetables. PMID:24895483

The decay of Redox-stress Response Capacity is a substantive characteristic of aging: Revising the redox theory of aging.

PubMed

Meng, Jiao; Lv, Zhenyu; Qiao, Xinhua; Li, Xiaopeng; Li, Yazi; Zhang, Yuying; Chen, Chang

2017-04-01

Aging is tightly associated with redox events. The free radical theory of aging indicates that redox imbalance may be an important factor in the aging process. Most studies about redox and aging focused on the static status of oxidative stress levels, there has been little research investigating differential responses to redox challenge during aging. In this study, we used Caenorhabditis elegans and human fibroblasts as models to compare differential responses to oxidative stress challenge in young and old individuals. In response to paraquat stress, young individuals generated more ROS and activated signaling pathways including p-ERK, p-AKT and p-AMPKα/β. After the initial response, young individuals then promoted NRF2 translocation and induced additional antioxidant enzymes and higher expression of phase II enzymes, including SOD, CAT, GPX, HO-1, GSTP-1and others, to maintain redox homeostasis. Moreover, young individuals also demonstrated a better ability to degrade damaged proteins by up-regulating the expression of chaperones and improving proteasome activity. Based on these data, we propose a new concept "Redox-stress Response Capacity (RRC)", which suggests cells or organisms are capable of generating dynamic redox responses to activate cellular signaling and maintain cellular homeostasis. The decay of RRC is the substantive characteristic of aging, which gives a new understand of the redox theory of aging. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Visual working memory capacity increases between ages 3 and 8 years, controlling for gains in attention, perception, and executive control.

PubMed

Pailian, Hrag; Libertus, Melissa E; Feigenson, Lisa; Halberda, Justin

2016-08-01

Research in adults has aimed to characterize constraints on the capacity of Visual Working Memory (VWM), in part because of the system's broader impacts throughout cognition. However, less is known about how VWM develops in childhood. Existing work has reached conflicting conclusions as to whether VWM storage capacity increases after infancy, and if so, when and by how much. One challenge is that previous studies did not control for developmental changes in attention and executive processing, which also may undergo improvement. We investigated the development of VWM storage capacity in children from 3 to 8 years of age, and in adults, while controlling for developmental change in exogenous and endogenous attention and executive control. Our results reveal that, when controlling for improvements in these abilities, VWM storage capacity increases across development and approaches adult-like levels between ages 6 and 8 years. More generally, this work highlights the value of estimating working memory, attention, perception, and decision-making components together.

Interaction among general practitioners age and patient load in the prediction of job strain, decision latitude and perception of job demands. A cross-sectional study.

PubMed

Vanagas, Giedrius; Bihari-Axelsson, Susanna

2004-12-07

It is widely recognized and accepted that job strain adversely impacts the workforce. Individual responses to stressful situations can vary greatly and it has been shown that certain people are more likely to experience high levels of stress in their job than others. Studies highlighted that there can be age differences in job strain perception. Cross-sectional postal survey of 300 Lithuanian general practitioners. Psychosocial stress was investigated with a questionnaire based on the Reeder scale. Job demands were investigated with the Karasek scale. The analysis included descriptive statistics; logistic regression beta coefficients to find out predictors and interactions between characteristics and predictors. Response rate was 66% (N = 197). Logistic regression as significant predictors for job strain assigned - duration of work in primary care; for job demands- age and duration of working in primary care; for decision latitude- age and patient load.The interactions with regard to job strain showed that GP's age and job strain are negatively associated to a low patient load. Lower decision latitude for older GP age is strongly related to higher patient load. Job demands and GP age are slightly positively related at low patient load. Lithuanian GP's have high patient load and are at risk of stress, they have high job demands and low decision latitude. Older GP's perceive less strain, lower job demands and higher decision latitude in case of low patient load. Young GP's decision latitude has week association to patient load. Regarding to the changes in patient load younger GP's perceive it more sensitively as changes in job demands.

Isolating Age-Group Differences in Working Memory Load-Related Neural Activity: Assessing the Contribution of Working Memory Capacity Using a Partial-Trial fMRI Method

PubMed Central

Bennett, Ilana J.; Rivera, Hannah G.; Rypma, Bart

2013-01-01

Previous studies examining age-group differences in working memory load-related neural activity have yielded mixed results. When present, age-group differences in working memory capacity are frequently proposed to underlie these neural effects. However, direct relationships between working memory capacity and working memory load-related activity have only been observed in younger adults. These relationships remain untested in healthy aging. Therefore, the present study examined patterns of working memory load-related activity in 22 younger and 20 older adults and assessed the contribution of working memory capacity to these load-related effects. Participants performed a partial-trial delayed response item recognition task during functional magnetic resonance imaging. In this task, participants encoded either 2 or 6 letters, maintained them during a delay, and then indicated whether a probe was present in the memory set. Behavioral results revealed faster and more accurate responses to load 2 versus 6, with age-group differences in this load condition effect for the accuracy measure. Neuroimaging results revealed one region (medial superior frontal gyrus) that showed age-group differences in load-related activity during the retrieval period, with less (greater) neural activity for the low versus high load condition in younger (older) adults. Furthermore, for older adults, load-related activity did not vary as a function of working memory capacity. Thus, working memory-related activity varies with healthy aging, but these patterns are not due solely to working memory capacity. Neurocognitive aging theories that feature capacity will need to account for these results. PMID:23357076

Isolating age-group differences in working memory load-related neural activity: assessing the contribution of working memory capacity using a partial-trial fMRI method.

PubMed

Bennett, Ilana J; Rivera, Hannah G; Rypma, Bart

2013-05-15

Previous studies examining age-group differences in working memory load-related neural activity have yielded mixed results. When present, age-group differences in working memory capacity are frequently proposed to underlie these neural effects. However, direct relationships between working memory capacity and working memory load-related activity have only been observed in younger adults. These relationships remain untested in healthy aging. Therefore, the present study examined patterns of working memory load-related activity in 22 younger and 20 older adults and assessed the contribution of working memory capacity to these load-related effects. Participants performed a partial-trial delayed response item recognition task during functional magnetic resonance imaging. In this task, participants encoded either 2 or 6 letters, maintained them during a delay, and then indicated whether a probe was present in the memory set. Behavioral results revealed faster and more accurate responses to load 2 versus 6, with age-group differences in this load condition effect for the accuracy measure. Neuroimaging results revealed one region (medial superior frontal gyrus) that showed age-group differences in load-related activity during the retrieval period, with less (greater) neural activity for the low versus high load condition in younger (older) adults. Furthermore, for older adults, load-related activity did not vary as a function of working memory capacity. Thus, working memory-related activity varies with healthy aging, but these patterns are not due solely to working memory capacity. Neurocognitive aging theories that feature capacity will need to account for these results. Copyright © 2013 Elsevier Inc. All rights reserved.

Different capacity of in vitro generated myeloid dendritic cells of newborns of healthy and allergic mothers to respond to probiotic strain E. coli O83:K24:H31.

PubMed

Súkeníková, Lenka; Černý, Viktor; Novotná, Olga; Petrásková, Petra; Boráková, Kristýna; Kolářová, Libuše; Prokešová, Ludmila; Hrdý, Jiří

2017-09-01

Allergic diseases belong to one of the most common diseases with steadily increasing incidence even among young children. There is an urgent need to identify a prognostic marker pointing to increased risk of allergy development enabling early preventive measures introduction. It has been shown that administration of selected probiotic strains or mixtures could prevent allergy development. In our study, we have tested the capacity of probiotic strain Escherichia coli O83:K24:H31 (E. coli O83) to promote dendritic cell (DC) maturation and polarisation of immune responses. Increased presence of activation marker CD83 was observed on DC stimulated by E. coli O83 and DC of newborns of allergic mothers have significantly more increased cell surface presence of CD83 in comparison to children of healthy mothers. Increased gene expression and secretion of IL-10 was detected in DC stimulated with E. coli O83 being higher in DC of newborns of healthy mothers in comparison to allergic ones. Generally, increased presence of intracellular cytokines (IL-4, IL-13, IFN-gamma, IL-17A, IL-22, IL-10) was detected in CD4+ T cells cocultured with DC of children of allergic mothers in comparison to healthy ones. E. coli O83 primed DC significantly increased IL-10 and IL-17A in CD4 T cells of newborns of healthy mothers in comparison to the levels detected in CD4 T cells cocultured with control non-stimulated DC. We can conclude E. coli O83 induces dendritic cell maturation and IL-10 production in DC. Newborns of allergic mothers have generally increased reactivity of both DC and CD4 T cells which together with decreased capacity of DC of newborns of allergic mothers to produce IL-10 could support inappropriate immune responses development after allergen encounter. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Influence of age, strain and season on circadian periodicity of pituitary, gonadal and adrenal hormones in the serum of male laboratory rats.

PubMed

Wong, C C; Döhler, K D; Geerlings, H; von zur Mühlen, A

1983-01-01

The influence of age, strain and season on the circadian pattern of serum levels of LH, FSH, prolactin androgens and corticosterone was studied in five groups of male laboratory rats. Significant 24-hour periodicity was observed for serum levels of corticosterone in all five groups, for androgen levels in four, for prolactin levels in three, for LH levels in two and for FSH levels in one group of rats. There were significant influences of age, strain and season on the temporal patterns and/or on 24-hour mean serum hormone levels. The results indicate that some of the disagreements on existence or nonexistence of circadian rhythms and on rhythm patterns in serum hormone levels may be explained by the fact that animals of different ages or strains had been used or that experiments were performed at different times of the year.

Aging reduces the neuroprotective capacity, VEGF secretion, and metabolic activity of rat choroid plexus epithelial cells.

PubMed

Emerich, Dwaine F; Schneider, Patricia; Bintz, Briannan; Hudak, Jebecka; Thanos, Christopher G

2007-01-01

Delivery of neurotrophic molecules to the brain has potential for preventing neuronal loss in neurodegenerative disorders. Choroid plexus (CP) epithelial cells secrete numerous neurotrophic factors, and encapsulated CP transplants are neuroprotective in models of stroke and Huntington's disease (HD). To date, all studies examining the neuroprotective potential of CP transplants have used cells isolated from young donor animals. Because the aging process significantly impacts the cytoarchitecture and function of the CP the following studies determined whether age-related impairments occur in its neuroprotective capacity. CP was isolated from either young (3-4 months) or aged (24 months) rats. In vitro, young CP epithelial cells secreted more VEGF and were metabolically more active than aged CP epithelial cells. Additionally, conditioned medium from cultured aged CP was less potent than young CP at enhancing the survival of serum-deprived neurons. Finally, encapsulated CP was tested in an animal model of HD. Cell-loaded or empty alginate capsules (control group) were transplanted unilaterally into the rat striatum. Seven days later, the animals received an injection of quinolinic acid (QA; 225 nmol) adjacent to the implant site. Animals were tested for motor function 28 days later. In the control group, QA lesions severely impaired function of the contralateral forelimb. Implants of young CP were potently neuroprotective as rats receiving CP transplants were not significantly impaired when tested for motor function. In contrast, implants of CP from aged rats were only modestly effective and were much less potent than young CP transplants. These data are the first to directly link aging with diminished neuroprotective capacity of CP epithelial cells.

The capacity-load model of non-communicable disease risk: understanding the effects of child malnutrition, ethnicity and the social determinants of health.

PubMed

Wells, Jonathan C K

2018-05-01

The capacity-load model is a conceptual model developed to improve understanding of the life-course aetiology of non-communicable diseases (NCDs) and their ecological and societal risk factors. The model addresses continuous associations of both (a) nutrition and growth patterns in early life and (b) lifestyle factors at older ages with NCD risk. Metabolic capacity refers to physiological traits strongly contingent on early nutrition and growth during the first 1000 days, which promote the long-term capacity for homeostasis in the context of fuel metabolism and cardiovascular health. Metabolic load refers to components of nutritional status and lifestyle that challenge homeostasis. The higher the load, and the lower the capacity, the greater the NCD risk. The model therefore helps understand dose-response associations of both early development and later phenotype with NCD risk. Infancy represents a critical developmental period, during which slow growth can constrain metabolic capacity, whereas rapid weight gain may elevate metabolic load. Severe acute malnutrition in early childhood (stunting, wasting) may continue to deplete metabolic capacity, and confer elevated susceptibility to NCDs in the long term. The model can be applied to associations of NCD risk with socio-economic position (SEP): lower SEP is generally associated with lower capacity but often also with elevated load. The model can also help explain ethnic differences in NCD risk, as both early growth patterns and later body composition differ systematically between ethnic groups. Recent work has begun to clarify the role of organ development in metabolic capacity, which may further contribute to ethnic differences in NCD risk.

Aging alters patterns of regional nonuniformity in LV strain relaxation: a 3-D MR tissue tagging study.

PubMed

Fonseca, Carissa G; Oxenham, Helen C; Cowan, Brett R; Occleshaw, Christopher J; Young, Alistair A

2003-08-01

Although age-related impairment of diastolic function is well documented, patterns of regional tissue relaxation impairment with age have not been characterized. MRI tissue tagging with a regional three-dimensional (3-D) analysis was performed in 15 younger (age 19-26 yr) and 16 older (age 60-74 yr) normal, healthy volunteers. The peak rate of relaxation of circumferential strain (RC) was decreased in the older group (on average, 105 +/- 28 vs. 163 +/- 18 %/s for older vs. younger, mean +/- SD, P < 0.001) to a greater extent in the lateral wall than in the septum (P = 0.016) and to a greater extent in the apex than in the base (P < 0.001). Peak rate of relaxation of longitudinal strain (RL) was also reduced with age (94 +/- 27 vs. 155 +/- 18 %/s, P < 0.001) to a greater extent in the apex than in the base (P < 0.001). Both RC and RL were greater in the apex than in the base only in the younger subjects (P < 0.001 for each). Peak rate of torsion reversal (RT) was reduced with age (74 +/- 16 vs. 91 +/- 15 degrees/s, P = 0.006) to a greater extent in the base than in the apex (P = 0.035). An increase in regional asynchrony in time to RC and time to RL (P < 0.001 for each), but not time to RT, occurred with age. Thus patterns of regional nonuniformity of myocardial relaxation are altered in a consistent fashion with aging.

Early language mediates the relations between preschool inattention and school-age reading achievement.

PubMed

O'Neill, Sarah; Thornton, Veronica; Marks, David J; Rajendran, Khushmand; Halperin, Jeffrey M

2016-05-01

Early inattention is associated with later reading problems in children, but the mechanism by which this occurs is unclear. We investigated whether the negative relation between preschoolers' ADHD symptoms and 8-year-old reading achievement is directly related to the severity of inattention or is mediated by early language skills. Children (n = 150; 76% boys) were evaluated at 3 time points: preschool (T1), mean (SD) age = 4.24 (.49) years; 1 year later (T2), mean (SD) age = 5.28 (.50) years; and during school age (T3), mean (SD) age = 8.61 (.31) years. At T1, parents' Kiddie-SADS responses were dimensionalized to reflect ADHD severity. Children completed the Language domain of the NEPSY (i.e., A Developmental Neuropsychological Assessment) at T1 and again at T2. At T3, children completed the Wechsler Individual Achievement Test, Second Edition Word Reading, Pseudoword Decoding, Reading Comprehension, and Spelling subtests, and their teachers completed ratings of Reading and Written Expression performance in school. The mediating effect of T2 Language on the relation between preschool Inattention and age 8 Reading was examined using the nonparametric bootstrapping procedure, while controlling for T1 Language. Language ability at T2 mediated the path from preschool inattention (but not hyperactivity/impulsivity) to 8-year-old reading achievement (both test scores and ratings) after controlling for preschoolers' language ability. Early attentional deficits may negatively impact school-age reading outcomes by compromising the development of language skills, which in turn imperils later reading achievement. Screening children with attentional problems for language impairment, as well as implementing early intervention for both attentional and language problems may be critical to promote reading achievement during school years. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Development of Visual Working Memory Capacity during Early Childhood

ERIC Educational Resources Information Center

Simmering, Vanessa R.

2012-01-01

The change detection task has been used in dozens of studies with adults to measure visual working memory capacity. Two studies have recently tested children in this task, suggesting a gradual increase in capacity from 5 years to adulthood. These results contrast with findings from an infant looking paradigm suggesting that capacity reaches…

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…

Dynamic strain aging behavior of modified 9Cr-1Mo and reduced activation ferritic martensitic steels under low cycle fatigue

NASA Astrophysics Data System (ADS)

Mariappan, K.; Shankar, Vani; Sandhya, R.; Prasad Reddy, G. V.; Mathew, M. D.

2013-04-01

Influence of temperature and strain rate on low cycle fatigue (LCF) behavior of modified 9Cr-1Mo ferritic martensitic steel and 1.4W-0.06Ta reduced activation ferritic martensitic (RAFM) steel in normalized and tempered conditions was studied. Total strain controlled LCF tests between 300 and 873 K on modified 9Cr-1Mo steel and RAFM steel and at various strain rates on modified 9Cr-1Mo steel were performed at total strain amplitude of ±0.6%. Both the steels showed continuous cyclic softening at all temperatures. Whereas manifestations of dynamic strain aging (DSA) were observed in both the steels which decreased fatigue life at intermediate temperatures, at higher temperatures, oxidation played a crucial role in decreasing fatigue life.

Events Associated with Early Age-Related Decline in Adventitious Rooting Competence of Eucalyptus globulus Labill.

PubMed

Aumond, Márcio L; de Araujo, Artur T; de Oliveira Junkes, Camila F; de Almeida, Márcia R; Matsuura, Hélio N; de Costa, Fernanda; Fett-Neto, Arthur G

2017-01-01

The development of adventitious roots is affected by several factors, including the age of the cutting donor plant, which negatively affects rooting capacity. Eucalyptus globulus quickly loses rooting capacity of cuttings as the donor plant ages, although the molecular and biochemical mechanisms behind this process are still unclear. To better understand the bases of rooting competence loss in E. globulus , the time required for a significant decline in rhizogenic ability without exogenous auxin was determined in microcuttings derived from donor plants of different ages after sowing. Tip cuttings of donor plants were severed before and after loss of rooting competence of microcuttings to test the hypothesis that auxin and carbohydrate homeostasis regulate rooting competence decline. There were no significant changes in concentration of carbohydrates, flavonoids, or proteins before and after the loss of rooting capacity. Peroxidase (EC 1.11.1.7) total activity increased with loss of rooting competence. Auxin concentration showed the opposite pattern. In good agreement, TAA1 , a key gene in auxin biosynthesis, had lower expression after loss of rooting capacity. The same applied to the auxin receptor gene TIR1 , suggesting reduced auxin sensitivity. On the other hand, genes associated with auxin response repression ( TPL , IAA12 ) or with the action of cytokinins, the rhizogenesis inhibitor-related ARR1 , showed higher expression in plants with lower rooting competence. Taken together, data suggest that age negatively affects E. globulus rooting by a combination of factors. Decreased endogenous auxin concentration, possibly caused by less biosynthesis, lower auxin sensitivity, higher expression of genes inhibiting auxin action, as well as of genes related to the action of cytokinins, appear to play roles in this process.

Events Associated with Early Age-Related Decline in Adventitious Rooting Competence of Eucalyptus globulus Labill

PubMed Central

Aumond, Márcio L.; de Araujo, Artur T.; de Oliveira Junkes, Camila F.; de Almeida, Márcia R.; Matsuura, Hélio N.; de Costa, Fernanda; Fett-Neto, Arthur G.

2017-01-01

The development of adventitious roots is affected by several factors, including the age of the cutting donor plant, which negatively affects rooting capacity. Eucalyptus globulus quickly loses rooting capacity of cuttings as the donor plant ages, although the molecular and biochemical mechanisms behind this process are still unclear. To better understand the bases of rooting competence loss in E. globulus, the time required for a significant decline in rhizogenic ability without exogenous auxin was determined in microcuttings derived from donor plants of different ages after sowing. Tip cuttings of donor plants were severed before and after loss of rooting competence of microcuttings to test the hypothesis that auxin and carbohydrate homeostasis regulate rooting competence decline. There were no significant changes in concentration of carbohydrates, flavonoids, or proteins before and after the loss of rooting capacity. Peroxidase (EC 1.11.1.7) total activity increased with loss of rooting competence. Auxin concentration showed the opposite pattern. In good agreement, TAA1, a key gene in auxin biosynthesis, had lower expression after loss of rooting capacity. The same applied to the auxin receptor gene TIR1, suggesting reduced auxin sensitivity. On the other hand, genes associated with auxin response repression (TPL, IAA12) or with the action of cytokinins, the rhizogenesis inhibitor-related ARR1, showed higher expression in plants with lower rooting competence. Taken together, data suggest that age negatively affects E. globulus rooting by a combination of factors. Decreased endogenous auxin concentration, possibly caused by less biosynthesis, lower auxin sensitivity, higher expression of genes inhibiting auxin action, as well as of genes related to the action of cytokinins, appear to play roles in this process. PMID:29067033

Prevalence of Early and Late Age-Related Macular Degeneration in India: The INDEYE Study

PubMed Central

Krishnan, Tiruvengada; Ravindran, Ravilla D.; Murthy, Gudlavalleti V. S.; Vashist, Praveen; Fitzpatrick, Kathryn E.; Thulasiraj, R. Duraisami; John, Neena; Maraini, Giovanni; Camparini, Monica; Chakravarthy, Usha

2010-01-01

Purpose. To estimate the prevalence of early and late age-related macular degeneration (AMD) in India. Methods. Of 7518 people aged 60 years and older identified from randomly sampled villages in North and South India, 5853 (78%) attended an eye examination including fundus photography. Fundus images were graded according to the Wisconsin Age-Related Maculopathy Grading System. Results. Fundus images were ungradable in 1587 people, mainly because of cataract. People 80 years of age and older were less likely to attend the eye examination and more likely to have ungradable images. For ages 60 to 79 years, the percent prevalence (95% confidence interval [CI]) were late AMD 1.2 (0.8–1.5); and early AMD: grade 1 (soft distinct drusen or pigmentary irregularities), 39.3 (37.2–41.5); grade 2 (soft distinct drusen with pigmentary irregularities or soft indistinct or reticular drusen), 6.7 (5.8–7.6); and grade 3 (soft indistinct or reticular drusen with pigmentary irregularities), 0.2 (0.1–0.4). For ages 80 and older, the respective percent prevalence was: late AMD, 2.5 (0.4–4.7); and early AMD: grade 1, 43.1(35.7–50.6); grade 2, 8.1 (4.3–12.0); and grade 3, 0.5 (0–1.5). Conclusions. The prevalence of early AMD (grades 1 and 2) is similar to that observed in Western populations, but grade 3 appears to be lower. The prevalence of late AMD is comparable to that in Western populations in the age group 60 to 79 years. It is likely that the prevalence in the 80 and older age group is underestimated. PMID:19696177

Donor age is a predictor of early low output after heart transplantation.

PubMed

Fujino, Takeo; Kinugawa, Koichiro; Nitta, Daisuke; Imamura, Teruhiko; Maki, Hisataka; Amiya, Eisuke; Hatano, Masaru; Kimura, Mitsutoshi; Kinoshita, Osamu; Nawata, Kan; Komuro, Issei; Ono, Minoru

2016-05-01

Using hearts from marginal donors could be related to increased risk of primary graft dysfunction and poor long-term survival. However, factors associated with delayed myocardial recovery after heart transplantation (HTx) remain unknown. We sought to clarify risk factors that predict early low output after HTx, and investigated whether early low output affects mid-term graft dysfunction. We retrospectively analyzed patients who had undergone HTx at The University of Tokyo Hospital. We defined early low output patients as those whose cardiac index (CI) was <2.2 L/min/m(2) despite the use of intravenous inotrope at 1 week after HTx. We included 45 consecutive HTx recipients, and classified 11 patients into early low output group, and the others into early preserved output group. We performed univariable logistic analysis and found that donor age was the only significant factor that predicted early low output (odds ratio 1.107, 95% confidence interval 1.034-1.210, p=0.002). CI of early low output patients gradually increased and it caught up with that of early preserved output patients at 2 weeks after HTx (2.4±0.6 L/min/m(2) in early low output group vs 2.5±0.5 L/min/m(2) in early preserved output group, p=0.684). Plasma B-type natriuretic peptide concentration of early low output patients was higher (1118.5±1250.2 pg/ml vs 526.4±399.5 pg/ml; p=0.033) at 1 week, 703.6±518.4 pg/ml vs 464.6±509.0 pg/ml (p=0.033) at 2 weeks, and 387.7±231.9 pg/ml vs 249.4±209.5 pg/ml (p=0.010) at 4 weeks after HTx, and it came down to that of early preserved output patients at 12 weeks after HTx. Donor age was a predictor of early low output after HTx. We should be careful after HTx from old donors. However, hemodynamic parameters of early low output patients gradually caught up with those of early preserved output patients. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

School Age Outcomes of Children with Autism Spectrum Disorder Who Received Community-Based Early Interventions.

PubMed

Vinen, Zoe; Clark, Megan; Paynter, Jessica; Dissanayake, Cheryl

2018-05-01

This study followed children with Autism Spectrum Disorder (ASD) from early intervention into their early schooling years, when they were aged between 6 and 9 years, on autism symptom severity and cognitive functioning. The children, matched at pre-intervention, were compared on type of community provided service: 31 were in receipt of community-based group Early Start Denver Model and 28 had received other community provisions for ASD. Irrespective of groups, cognitive functioning was found to have significantly improved by school age compared to pre-intervention. Autism symptom severity increased during the same developmental period, seemingly driven by an increase in restricted and repetitive behaviours over time. In contrast, both groups displayed improved social affect by school age.

Methodology optimization and diversification for the investigation of virulence potential in Haemophilus influenzae clinical strains.

PubMed

Giucă, Mihaela Cristina; Străuţ, Monica; Surdeanu, Maria; Nica, Maria; Ungureanu, Vasilica; Mihăescu, Grigore

2011-01-01

Ten Haemophilus influenzae strains were isolated from patients aged between 1.6 - 24 years, with various diagnoses (acute meningitis, acute upper respiratory infection, otitis media and acute sinusitis). Identification was based on phenotypic and molecular characteristics; antibiotic susceptibility testing was performed by diffusion method according to CLSI standards 2011 for seven antibiotics. The results of molecular testing showed that all the studied strains produced an amplicon of 1000 bp with ompP2 primers indicating that all strains were H. influenzae. For six strains, the PCR amplicon obtained with bexA specific primers, proving that the strains were capsulated. The results of phenotypic testing showed that four strains were ampicillin nonsusceptible and (beta-lactamase-positive. The virulence potential of H. influenzae clinical strains was investigated by phenotypic methods, including the assessment of the soluble virulence factors on specific media containing the biochemical substratum for the investigated enzymatic factor, as well as the adherence and invasion capacity to HeLa cells monolayer using Cravioto modified method. The studied strains exhibited mainly a diffuse adherence pattern and different adherence indexes. Interestingly, two strains isolated from the same pacient (blood and CSF) showed a different degree of invasiveness, the strain isolated from blood being 20 times more invasive than the one isolated from CSF.

AGEs Decreased SIRT3 Expression and SIRT3 Activation Protected AGEs-Induced EPCs' Dysfunction and Strengthened Anti-oxidant Capacity.

PubMed

Chang, Mingze; Zhang, Bei; Tian, Ye; Hu, Ming; Zhang, Gejuan; Di, Zhengli; Wang, Xinlai; Liu, Zhiqin; Gu, Naibin; Liu, Yong

2017-04-01

Advanced glycation end products (AGEs) have been confirmed to induce dysfunction in endothelial progenitor cells (EPCs) and play key roles in pathogenesis of diabetes-related vascular complications. The major function of sirtuin 3 (SIRT3) is to orchestrate oxidative metabolism and control reactive oxygen species (ROS) homeostasis, which are more closely related to EPCs' dysfunction. Our study therefore was designed to explore the role of SIRT3 on AGEs-induced EPCs dysfunction of. EPCs isolated from healthy adults were stimulated with AGEs and the expression of SIRT3 was assessed. Then, EPCs transfected with ad-SIRT3 or siRNA-SIRT3 were cultured with or without AGEs. EPCs function, including proliferation, migration; expression of manganese superoxide dismutase (MnSOD), ROS production, and interleukin-8 (IL-8); and vascular endothelial growth factor (VEGF) production were measured. In some experiments, EPCs were pre-cultured with anti-receptor for advanced glycation end products (RAGE) antibody or anti-neutralizing antibody, and then proliferation, migration, expression of MnSOD, ROS production, and IL-8 and VEGF production were measured. Our results showed that SIRT3 expressed in EPCs and AGEs decreased SIRT3 expression. SIRT3 knockdown with siRNA-SIRT3 promoted dysfunction in EPCs whereas SIRT3 activation with ad-SIRT3 strengthened anti-oxidant capacity and protected AGE-impaired dysfunction. Moreover, RAGE may involve in AGEs-decreased SIRT3 expression in EPCs. These data suggested an important role of SIRT3 in regulating EPCs bioactivity.

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...

Do attentional capacities and processing speed mediate the effect of age on executive functioning?

PubMed

Gilsoul, Jessica; Simon, Jessica; Hogge, Michaël; Collette, Fabienne

2018-02-06

The executive processes are well known to decline with age, and similar data also exists for attentional capacities and processing speed. Therefore, we investigated whether these two last nonexecutive variables would mediate the effect of age on executive functions (inhibition, shifting, updating, and dual-task coordination). We administered a large battery of executive, attentional and processing speed tasks to 104 young and 71 older people, and we performed mediation analyses with variables showing a significant age effect. All executive and processing speed measures showed age-related effects while only the visual scanning task performance (selective attention) was explained by age when controlled for gender and educational level. Regarding mediation analyses, visual scanning partially mediated the age effect on updating while processing speed partially mediated the age effect on shifting, updating and dual-task coordination. In a more exploratory way, inhibition was also found to partially mediate the effect of age on the three other executive functions. Attention did not greatly influence executive functioning in aging while, in agreement with the literature, processing speed seems to be a major mediator of the age effect on these processes. Interestingly, the global pattern of results seems also to indicate an influence of inhibition but further studies are needed to confirm the role of that variable as a mediator and its relative importance by comparison with processing speed.

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.

Effects of strain variations on aging response and corrosion properties of third generation Al-Li alloys

NASA Astrophysics Data System (ADS)

Wright, Ellen E.

Due to their high specific strength (strength/density) and specific stiffness (elastic modulus/density), Al-Li alloys are attractive alloys for structural aircraft applications. To produce contoured aircraft components from Al-Li wrought products, stretch forming prior to aging is a common manufacturing technique. The effects of different amounts of tensile straining (0-9%) on the mechanical, microstructural, and corrosion properties of two third generation Al-Li alloys (2099 and 2196) were investigated. In addition to typical characterization techniques, electron backscatter diffraction (EBSD), 2D micro-digital image correlation (DIC), and scanning Kelvin probe force microscopy (SKPFM) were used to examine site-specific effects of orientation, micro-strain evolution during straining, and surface potential on corrosion, respectively. Tapping mode atomic force microscopy (AFM) was also performed to study galvanic corrosion in artificial seawater (3.5% NaCl) as it occurred in-situ. There was evidence of intergranular corrosion for 0% strain conditions, but the dominant form of corrosion was localized pitting for all specimens except Alloy 2196 strained 0%. Pitting initiated at grain boundaries and triple points. In many cases, pitting extended into particular grains and was elongated in the extrusion direction. Regions of high micro-strain preferentially corroded, and large, recrystallized grains in mostly unrecrystallized microstructures were detrimental to corrosion properties. Recommendations for improved thermomechanical processing and/or alloying to promote corrosion resistance of 2XXX series Al-Li alloys were investigated.

In vivo effect of single oral dose of artemether against early juvenile stages of Schistosoma mansoni Egyptian strain.

PubMed

El-Beshbishi, Samar N; Taman, Amira; El-Malky, Mohamed; Azab, Manar S; El-Hawary, Amira K; El-Tantawy, Dina A

2013-10-01

The current treatment and control of schistosomiasis, rely on a single drug, praziquantel, although, it has minor activity against juvenile stages of the parasite. Studies have shown that artemether (ART) exhibits effects against juveniles of Schistosoma mansoni Liberian and Puerto Rican strains, Schistosoma japonicum and Schistosoma haematobium. Aiming to assess the in vivo activity of single oral dose of ART against early juvenile stages of S. mansoni Egyptian strain, this study was established. Mice were treated with ART (400 mg/kg) at two time points evenly spaced over the period of larval development (7 and 21 days post-infection; pi), and a third treatment point (day 49 pi) was included to elucidate when susceptibility decreases. Administration of ART on day 7 pi reduced the total worm burden by 85.94%. The greatest reductions were seen when treatment was given on day 21 pi, with total and female worm burden reductions of 91.52% and 90.57%, respectively, and cessation of oviposition. Similar dose given on day 49 pi reduced total worm burden by 55.17% and female worm burden by 66.51%. Moreover, it induced significant reduction in the tissue egg load and significant alterations in the oogram pattern with decreased immature eggs and increased dead eggs. Antipathological activities were evident in significant reductions in granulomata count and diameter. In conclusion, ART exhibits major in vivo schistosomicidal effects against the early larval migratory stages of S. mansoni Egyptian strain, mainly the 21-day old schistosomula, hence preventing disease progression and morbidity. Copyright © 2013 Elsevier Inc. All rights reserved.

Feedback-controlled robotics-assisted treadmill exercise to assess and influence aerobic capacity early after stroke: a proof-of-concept study.

PubMed

Stoller, Oliver; Schindelholz, Matthias; Bichsel, Lukas; Schuster, Corina; de Bie, Rob A; de Bruin, Eling D; Hunt, Kenneth J

2014-07-01

The majority of post-stroke individuals suffer from low exercise capacity as a secondary reaction to immobility. The aim of this study was to prove the concept of feedback-controlled robotics-assisted treadmill exercise (RATE) to assess aerobic capacity and guide cardiovascular exercise in severely impaired individuals early after stroke. Subjects underwent constant load and incremental exercise testing using a human-in-the-loop feedback system within a robotics-assisted exoskeleton (Lokomat, Hocoma AG, CH). Inclusion criteria were: stroke onset ≤8 weeks, stable medical condition, non-ambulatory status, moderate motor control of the lower limbs and appropriate cognitive function. Outcome measures included oxygen uptake kinetics, peak oxygen uptake (VO2peak), gas exchange threshold (GET), peak heart rate (HRpeak), peak work rate (Ppeak) and accuracy of reaching target work rate (P-RMSE). Three subjects (18-42 d post-stroke) were included. Oxygen uptake kinetics during constant load ranged from 42.0 to 60.2 s. Incremental exercise testing showed: VO2peak range 19.7-28.8 ml/min/kg, GET range 11.6-12.7 ml/min/kg, and HRpeak range 115-161 bpm. Ppeak range was 55.2-110.9 W and P-RMSE range was 3.8-7.5 W. The concept of feedback-controlled RATE for assessment of aerobic capacity and guidance of cardiovascular exercise is feasible. Further research is warranted to validate the method on a larger scale. Aerobic capacity is seriously reduced in post-stroke individuals as a secondary reaction to immobility. Robotics-assisted walking devices may have substantial clinical relevance regarding assessment and improvement of aerobic capacity early after stroke. Feedback-controlled robotics-assisted treadmill exercise represents a new concept for cardiovascular assessment and intervention protocols for severely impaired individuals.

High Exercise Capacity Attenuates the Risk of Early Mortality After a First Myocardial Infarction: The Henry Ford Exercise Testing (FIT) Project.

PubMed

Shaya, Gabriel E; Al-Mallah, Mouaz H; Hung, Rupert K; Nasir, Khurram; Blumenthal, Roger S; Ehrman, Jonathan K; Keteyian, Steven J; Brawner, Clinton A; Qureshi, Waqas T; Blaha, Michael J

2016-02-01

To examine the effect of objectively measured exercise capacity (EC) on early mortality (EM) after a first myocardial infarction (MI). This retrospective cohort study included 2061 patients without a history of MI (mean age, 62±12 years; 38% [n=790] women; 56% [n=1153] white) who underwent clinical treadmill stress testing in the Henry Ford Health System from January 1, 1991, through May 31, 2009, and suffered MI during follow-up (MI event proportion, 3.4%; mean time from the exercise test to MI, 6.1±4.3 years). Exercise capacity was categorized on the basis of peak metabolic equivalents (METs) achieved: less than 6, 6 to 9, 10 to 11, and 12 or more METs. Early mortality was defined as all-cause mortality within 28, 90, or 365 days of MI. Multivariable logistic regression models were used to assess the effect of EC on the risk of mortality at each time point post-MI adjusting for baseline demographic characteristics, cardiovascular risk factors, medication use, indication for stress testing, and year of MI. The 28-day EM rate was 10.6% overall, and 13.9%, 10.7%, 6.9%, and 6.0% in the less than 6, 6 to 9, 10 to 11, and 12 or more METs categories, respectively (P<.001). Patients who died were more likely to be older, be less fit, be nonobese, have treated hypertension, and have a longer duration from baseline to incident MI (P<.05). Adjusted regression analyses revealed a decreased risk of EM with increasing EC categories. A 1-MET higher EC was associated with an 8% to 10% lower risk of mortality across all time points (28 days: odds ratio [OR], 0.92; 95% CI, 0.87-0.98; P=.006; 90 days: OR, 0.90; 95% CI, 0.86-0.95; P<.001; 365 days: OR, 0.91; 95% CI, 0.87-0.94; P<.001). Higher baseline EC was independently associated with a lower risk of early death after a first MI. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Early developmental milestones and age of independent walking in orphans compared with typical home-raised infants.

PubMed

Chaibal, Supattra; Bennett, Surussawadi; Rattanathanthong, Korrawan; Siritaratiwat, Wantana

2016-10-01

Early gross motor development is a major indicator of global milestones in the first year of life, affecting the walking ability of a child. There has been limited research reporting on early motor development and the age of independent walking of orphaned infants compared to typical home-raised infants. The purpose of this study was to compare the mean scores of early gross motor movement at 4, 6 and 8months of age and at the age of walking attainment of typically raised infants and orphaned infants. In addition, we looked to compare the walking age between these same infants. This cross-sectional study recruited 59 typical home-raised infants and 62 orphans. Their gross motor development was assessed using the Alberta Infant Motor Scale (AIMS). The age of walking attainment was also prospectively monitored and ascertained. The Student's independent t-test was used to analyse the differences of the AIMS scores at 4, 6 and 8months of age and at the age of independent walking between the two groups. The orphans showed significantly lower AIMS scores at 4, 6 and 8months of age and the age of independent walking (P-value<0.05). The orphan group had a 5-month older mean age of walking attainment (15.0±4.2months) compared with typical home-raised infants (9.9±1.4months). Orphans have delays in early gross motor development and walk independently at an older age, compared with home-raised infants. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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.

[Age-associated peculiarities of microcirculation system in skeletal muscles and their role in muscle work capacity in human aging (author's transl)].

PubMed

Korkusko, O V; Sarkisov, K G; Frajfel'd, V E

1982-01-01

The muscle blood flow was investigated at rest (MBFR) and after physical load under ischemia conditions (maximal muscle blood flow--MMBF) in 87 practically healthy persons (45 women and 42 men) aged 20--90. The state of muscle blood flow was evaluated by means of the clearance of 133xenon injected into M. tibialis anterior. The data obtained showed a decrease of MBFR and MMBF in older people as compared with younger subjects. In realization of this phenomenon a decrease in muscle capillarisation and a reduction in reactivity of microcirculatory link of vascular system plays an increasingly greater role with aging. The reduction in muscle blood flow forms a circulatory component of the age-associated hypoxia. This fact results in a decrease of muscle blood flow and limits the functional capacity of skeletal muscle under conditions of activity.

GhNAC12, a neutral candidate gene, leads to early aging in cotton (Gossypium hirsutum L).

PubMed

Zhao, Fengli; Ma, Jianhui; Li, Libei; Fan, Shuli; Guo, Yaning; Song, Meizhen; Wei, Hengling; Pang, Chaoyou; Yu, Shuxun

2016-01-15

NAC (NAM, ATAF, and CUC) is one of the largest transcription factor families in plants, and its members play various roles in plant growth, development, and the response to biotic and abiotic stresses. Currently, 77 NAC genes have been reported in cotton (Gossypium hirsutum L.). And GhNAC12 showed up-regulation during leaf senescence, but its role in this process is poorly understood. In the present study, a preliminary function analysis of GhNAC12 was performed during leaf senescence. qRT-PCR analysis indicated that GhNAC12 expression increased during the early-aging process and the aging of cotyledons. Additionally, we observed that overexpression of GhNAC12 in Arabidopsis led to early senescence (early aging). Our findings suggest that GhNAC12 is a candidate gene for early aging in upland cotton cultivars. Neutrality tests suggested that there was no selection pressure imposed on GhNAC12 during the domestication of upland cotton. Copyright © 2015 Elsevier B.V. All rights reserved.

High-quality permanent draft genome sequence of the Mimosa asperata - nodulating Cupriavidus sp. strain AMP6

DOE PAGES

De Meyer, Sofie E.; Parker, Matthew; Van Berkum, Peter; ...

2015-10-16

Cupriavidus sp. strain AMP6 is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from a root nodule of Mimosa asperata collected in Santa Ana National Wildlife Refuge, Texas, in 2005. Mimosa asperata is the only legume described so far to exclusively associates with Cupriavidus symbionts. Furthermore, strain AMP6 represents an early-diverging lineage within the symbiotic Cupriavidus group and has the capacity to develop an effective nitrogen-fixing symbiosis with three other species of Mimosa. Here, we describe the genome of Cupriavidus sp. strain AMP6 which enables comparative analyses of symbiotic trait evolution in this genus; the general features, together withmore » sequence and annotation are further discussed. Finally, the 7,579,563 bp high-quality permanent draft genome is arranged in 260 scaffolds of 262 contigs, contains 7,033 protein-coding genes and 97 RNA-only encoding genes, and is part of the GEBA-RNB project proposal.« less

High-quality permanent draft genome sequence of the Mimosa asperata - nodulating Cupriavidus sp. strain AMP6

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Meyer, Sofie E.; Parker, Matthew; Van Berkum, Peter

Cupriavidus sp. strain AMP6 is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from a root nodule of Mimosa asperata collected in Santa Ana National Wildlife Refuge, Texas, in 2005. Mimosa asperata is the only legume described so far to exclusively associates with Cupriavidus symbionts. Furthermore, strain AMP6 represents an early-diverging lineage within the symbiotic Cupriavidus group and has the capacity to develop an effective nitrogen-fixing symbiosis with three other species of Mimosa. Here, we describe the genome of Cupriavidus sp. strain AMP6 which enables comparative analyses of symbiotic trait evolution in this genus; the general features, together withmore » sequence and annotation are further discussed. Finally, the 7,579,563 bp high-quality permanent draft genome is arranged in 260 scaffolds of 262 contigs, contains 7,033 protein-coding genes and 97 RNA-only encoding genes, and is part of the GEBA-RNB project proposal.« less

Brain diabetic neurodegeneration segregates with low intrinsic aerobic capacity

PubMed Central

Choi, Joungil; Chandrasekaran, Krish; Demarest, Tyler G; Kristian, Tibor; Xu, Su; Vijaykumar, Kadambari; Dsouza, Kevin Geoffrey; Qi, Nathan R; Yarowsky, Paul J; Gallipoli, Rao; Koch, Lauren G; Fiskum, Gary M; Britton, Steven L; Russell, James W

2014-01-01

Objectives Diabetes leads to cognitive impairment and is associated with age-related neurodegenerative diseases including Alzheimer's disease (AD). Thus, understanding diabetes-induced alterations in brain function is important for developing early interventions for neurodegeneration. Low-capacity runner (LCR) rats are obese and manifest metabolic risk factors resembling human “impaired glucose tolerance” or metabolic syndrome. We examined hippocampal function in aged LCR rats compared to their high-capacity runner (HCR) rat counterparts. Methods Hippocampal function was examined using proton magnetic resonance spectroscopy and imaging, unbiased stereology analysis, and a Y maze. Changes in the mitochondrial respiratory chain function and levels of hyperphosphorylated tau and mitochondrial transcriptional regulators were examined. Results The levels of glutamate, myo-inositol, taurine, and choline-containing compounds were significantly increased in the aged LCR rats. We observed a significant loss of hippocampal neurons and impaired cognitive function in aged LCR rats. Respiratory chain function and activity were significantly decreased in the aged LCR rats. Hyperphosphorylated tau was accumulated within mitochondria and peroxisome proliferator-activated receptor-gamma coactivator 1α, the NAD+-dependent protein deacetylase sirtuin 1, and mitochondrial transcription factor A were downregulated in the aged LCR rat hippocampus. Interpretation These data provide evidence of a neurodegenerative process in the hippocampus of aged LCR rats, consistent with those seen in aged-related dementing illnesses such as AD in humans. The metabolic and mitochondrial abnormalities observed in LCR rat hippocampus are similar to well-described mechanisms that lead to diabetic neuropathy and may provide an important link between cognitive and metabolic dysfunction. PMID:25356430

Uptake and impact of vaccinating school age children against influenza during a season with circulation of drifted influenza A and B strains, England, 2014/15.

PubMed

Pebody, Richard G; Green, Helen K; Andrews, Nick; Boddington, Nicola L; Zhao, Hongxin; Yonova, Ivelina; Ellis, Joanna; Steinberger, Sophia; Donati, Matthew; Elliot, Alex J; Hughes, Helen E; Pathirannehelage, Sameera; Mullett, David; Smith, Gillian E; de Lusignan, Simon; Zambon, Maria

2015-01-01

The 2014/15 influenza season was the second season of roll-out of a live attenuated influenza vaccine (LAIV) programme for healthy children in England. During this season, besides offering LAIV to all two to four year olds, several areas piloted vaccination of primary (4-11 years) and secondary (11-13 years) age children. Influenza A(H3N2) circulated, with strains genetically and antigenically distinct from the 2014/15 A(H3N2) vaccine strain, followed by a drifted B strain. We assessed the overall and indirect impact of vaccinating school age children, comparing cumulative disease incidence in targeted and non-targeted age groups in vaccine pilot to non-pilot areas. Uptake levels were 56.8% and 49.8% in primary and secondary school pilot areas respectively. In primary school age pilot areas, cumulative primary care influenza-like consultation, emergency department respiratory attendance, respiratory swab positivity, hospitalisation and excess respiratory mortality were consistently lower in targeted and non-targeted age groups, though less for adults and more severe end-points, compared with non-pilot areas. There was no significant reduction for excess all-cause mortality. Little impact was seen in secondary school age pilot only areas compared with non-pilot areas. Vaccination of healthy primary school age children resulted in population-level impact despite circulation of drifted A and B influenza strains.

Mineralization of soil-aged isoproturon and isoproturon metabolites by Sphingomonas sp. strain SRS2.

PubMed

Johannesen, Helle; Sørensen, Sebastian R; Aamand, Jens

2003-01-01

The aim of the study was to determine the effect of aging of the herbicide isoproturon and its metabolites monodesmethyl-isoproturon and 4-isopropyl-aniline in agricultural soil on their availability to the degrading bacterium Sphingomonas sp. strain SRS2. The 14C-ring-labeled isoproturon, monodesmethyl-isoproturon, and 4-isopropyl-aniline were added to sterilized soil and stored for 1, 49, 71, or 131 d before inoculation with strain SRS2. The availability of the compounds was estimated from the initial mineralization and the amount of 14CO2 recovered after 120 d of incubation. Aging in soil for 131 d reduced the initial mineralization of isoproturon and monodesmethyl-isoproturon and, in the case of isoproturon, also reduced the recovery of 14CO2. Initial mineralization and recovery of 14CO2 from aged 4-isopropyl-aniline were slightly reduced, but less 14CO2 was generally produced than with isoproturon or monodesmethyl-isoproturon. Thus, recovery of 14CO2 from 14C-isoproturon and 14C-monodesmethyl-isoproturon was 50.7 to 64.4% of the initially added 14C, while recovery from 14C-4-isopropyl-aniline was only 11.7 to 17.0%. Sorption measurements revealed similar Freundlich constants (K(f)) for isoproturon and monodesmethyl-isoproturon, whereas K(f) for 4-isopropyl-aniline was more than fivefold greater. The findings imply that in soil, partial degradation of isoproturon to 4-isopropyl-aniline may lead to reduced mineralization of the herbicide due to sorption of the aniline moiety.

Genetic and pharmacological factors that influence reproductive aging in nematodes.

PubMed

Hughes, Stacie E; Evason, Kimberley; Xiong, Chengjie; Kornfeld, Kerry

2007-02-16

Age-related degenerative changes in the reproductive system are an important aspect of aging, because reproductive success is the major determinant of evolutionary fitness. Caenorhabditis elegans is a prominent organism for studies of somatic aging, since many factors that extend adult lifespan have been identified. However, mechanisms that control reproductive aging in nematodes or other animals are not well characterized. To use C. elegans to measure reproductive aging, we analyzed mated hermaphrodites that do not become sperm depleted and monitored the duration and level of progeny production. Mated hermaphrodites display a decline of progeny production that culminates in reproductive cessation before the end of the lifespan, demonstrating that hermaphrodites undergo reproductive aging. To identify factors that influence reproductive aging, we analyzed genetic, environmental, and pharmacological factors that extend lifespan. Dietary restriction and reduced insulin/insulin-like growth factor signaling delayed reproductive aging, indicating that nutritional status and a signaling pathway that responds to environmental stress influence reproductive aging. Cold temperature delayed reproductive aging. The anticonvulsant medicine ethosuximide, which affects neural activity, delayed reproductive aging, indicating that neural activity can influence reproductive aging. Some of these factors decrease early progeny production, but there is no consistent relationship between early progeny production and reproductive aging in strains with an extended lifespan. To directly examine the effects of early progeny production on reproductive aging, we used sperm availability to modulate the level of early reproduction. Early progeny production neither accelerated nor delayed reproductive aging, indicating that reproductive aging is not controlled by use-dependent mechanisms. The implications of these findings for evolutionary theories of aging are discussed.

Early and intermediate age-related macular degeneration: update and clinical review.

PubMed

García-Layana, Alfredo; Cabrera-López, Francisco; García-Arumí, José; Arias-Barquet, Lluís; Ruiz-Moreno, José M

2017-01-01

Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in developed countries. With the aging of population, AMD will become globally an increasingly important and prevalent disease worldwide. It is a complex disease whose etiology is associated with both genetic and environmental risk factors. An extensive decline in the quality of life and progressive need of daily living assistance resulting from AMD among those most severely affected highlights the essential role of preventive strategies, particularly advising patients to quit smoking. In addition, maintaining a healthy diet, controlling other risk factors (such as hypertension, obesity, and atherosclerosis), and the use of nutritional supplements (antioxidants) are recommendable. Genetic testing may be especially important in patients with a family history of AMD. Recently, unifying criteria for the clinical classification of AMD, defining no apparent aging changes; normal aging changes; and early, intermediate, and late AMD stages, are of value in predicting AMD risk of progression and in establishing recommendations for the diagnosis, therapeutic approach, and follow-up of patients. The present review is focused on early and intermediate AMD and presents a description of the clinical characteristics and ophthalmological findings for these stages, together with algorithms for the diagnosis and management of patients, which are easily applicable in daily clinical practice.

Early and intermediate age-related macular degeneration: update and clinical review

PubMed Central

García-Layana, Alfredo; Cabrera-López, Francisco; García-Arumí, José; Arias-Barquet, Lluís; Ruiz-Moreno, José M

2017-01-01

Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in developed countries. With the aging of population, AMD will become globally an increasingly important and prevalent disease worldwide. It is a complex disease whose etiology is associated with both genetic and environmental risk factors. An extensive decline in the quality of life and progressive need of daily living assistance resulting from AMD among those most severely affected highlights the essential role of preventive strategies, particularly advising patients to quit smoking. In addition, maintaining a healthy diet, controlling other risk factors (such as hypertension, obesity, and atherosclerosis), and the use of nutritional supplements (antioxidants) are recommendable. Genetic testing may be especially important in patients with a family history of AMD. Recently, unifying criteria for the clinical classification of AMD, defining no apparent aging changes; normal aging changes; and early, intermediate, and late AMD stages, are of value in predicting AMD risk of progression and in establishing recommendations for the diagnosis, therapeutic approach, and follow-up of patients. The present review is focused on early and intermediate AMD and presents a description of the clinical characteristics and ophthalmological findings for these stages, together with algorithms for the diagnosis and management of patients, which are easily applicable in daily clinical practice. PMID:29042759

Genetic mouse models of brain ageing and Alzheimer's disease.

PubMed

Bilkei-Gorzo, Andras

2014-05-01

Progression of brain ageing is influenced by a complex interaction of genetic and environmental factors. Analysis of genetically modified animals with uniform genetic backgrounds in a standardised, controlled environment enables the dissection of critical determinants of brain ageing on a molecular level. Human and animal studies suggest that increased load of damaged macromolecules, efficacy of DNA maintenance, mitochondrial activity, and cellular stress defences are critical determinants of brain ageing. Surprisingly, mouse lines with genetic impairment of anti-oxidative capacity generally did not show enhanced cognitive ageing but rather an increased sensitivity to oxidative challenge. Mouse lines with impaired mitochondrial activity had critically short life spans or severe and rapidly progressing neurodegeneration. Strains with impaired clearance in damaged macromolecules or defects in the regulation of cellular stress defences showed alterations in the onset and progression of cognitive decline. Importantly, reduced insulin/insulin-like growth factor signalling generally increased life span but impaired cognitive functions revealing a complex interaction between ageing of the brain and of the body. Brain ageing is accompanied by an increased risk of developing Alzheimer's disease. Transgenic mouse models expressing high levels of mutant human amyloid precursor protein showed a number of symptoms and pathophysiological processes typical for early phase of Alzheimer's disease. Generally, therapeutic strategies effective against Alzheimer's disease in humans were also active in the Tg2576, APP23, APP/PS1 and 5xFAD lines, but a large number of false positive findings were also reported. The 3xtg AD model likely has the highest face and construct validity but further studies are needed. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of Aging on the Proliferation and Differentiation Capacity of Human Periodontal Ligament Stem Cells.

PubMed

Du, Tingting; Liu, Na; Gu, Bin; Li, Ying; Yuan, Yifang; Zhang, Wei; Zhang, Tong

2017-06-10

Objective The aim of this study is to investigate the proliferation, differentiation and apoptosis of periodontal ligament stem cells (PDLSC) derived from different aged donors, and to evaluate the effects of aging on the biological characteristics of PDLSC.Methods Periodontal ligament tissues were obtained from 24 surgically extracted human premolars during orthodontics therapy. The specimens were divided into three groups according to the donor's age. Group A: 18-20 years, group B: 30-35 years, group C: 45-50 years. PDLSC were isolated and cultured using a tissue-block-based enzymolytic method by limiting dilution assay. The colony forming efficiency of PDLSC for three experimental groups was determined. Senescence-Associated β-Galactosidase (SA-β-G) expression in the three groups was examined using β-galactosidase staining working solution. Cell cycle and apoptosis of the PDLSC were examined by the flow cytometry. Alkaline phosphatase (ALP) activity was evaluated by ALP staining. The expression of osteoplastic differentiation related genes Runt-related transcription factor-2 (Runx-2), Collagen Type 1 (col-1), and ALP of PDLSC were examined by quantitative real-time RT-PCR.Results The colony forming efficiency of PDLSC in Group A, B and C was 36.67%, 22.67% and 9.33%, respectively, which decreased with donors' age (P<0.05). SA-β-G expression of the senescent PDLSC in group A, B and C were 4.14%, 16.39%, 50.38%, respectively (P<0.05). Cells in G2/S phase was 38.73%, 29.88%, 18.25% (P<0.05), and the apoptosis rate was 1.57%, 4.56%, 5.84% (P<0.05), in group A, B and C respectively. The ALP staining in the three groups decreased with the increase of donors' ages, and the expression of Runx-2, col-1 and ALP decreased gradually from group A to group C (all P<0.05), which indicated the osteogenic differentiation capacity of PDLSC decreased while donor aging.Conclusion Human PDLSC could be successfully isolated from periodontal ligament tissues of different aged

The Association Between Depression, Suicidal Ideation and Psychological Strains in College Students: A Cross-National Study.

PubMed

Zhao, Sibo; Zhang, Jie

2018-06-19

This study examined the differences of psychological strains between Chinese and American college students and discussed how strains may influence individuals' suicidal ideation and depression. A total of 539 college students (298 from China and 241 from the U.S.) were recruited in March 2016 to complete the survey study. Multiple linear regressions were used in data analysis. Students in America had higher scores on depression and stress than students in China, while students in China rated higher on suicidal ideation than students in America. In contrast of students in America facing more coping strains, students in China were confronting more value strains in their life. The cross-cultural variations in the effect of psychological strains have been substantiated in current study, indicating that understanding the psychological strains in different cultural contexts is necessary for the early intervention and prevention in college aged populations.

Education and Learning in the Early Middle Ages: New Perspectives and Old Problems.

ERIC Educational Resources Information Center

Contreni, John J.

1989-01-01

Discusses various scholarly views of education and learning in the early middle ages and identifies some problems confronting scholars investigating this period. Points out new perspectives relative to the role of education during this time. Asserts that future study of early medieval education will benefit from focusing on the minds of masters…

Early Generated B-1-Derived B Cells Have the Capacity To Progress To Become Mantle Cell Lymphoma-like Neoplasia in Aged Mice.

PubMed

Hayakawa, Kyoko; Formica, Anthony M; Nakao, Yuka; Ichikawa, Daiju; Shinton, Susan A; Brill-Dashoff, Joni; Smith, Mitchell R; Morse, Herbert C; Hardy, Richard R

2018-06-13

In mice, fetal/neonatal B-1 cell development generates murine CD5 + B cells (B1a) with autoreactivity. We analyzed B1a cells at the neonatal stage in a V H 11/D/J H knock-in mouse line (V H 11t) that generates an autoreactive antiphosphatidylcholine BCR. Our study revealed that antiphosphatidylcholine B1a cells develop in liver, mature in spleen, and distribute in intestine/colon, mesenteric lymph node (mLN), and body cavity as the outcome of B-1 cell development before B-2 cell development. Throughout life, self-renewing B-1 B1a cells circulate through intestine, mesenteric vessel, and blood. The body cavity-deposited B1a cells also remigrate. In old age, some B1a cells proceed to monoclonal B cell lymphocytosis. When neonatal B-1 B1a cells express an antithymocyte/Thy-1 autoreactivity (ATA) BCR transgene in the C.B17 mouse background, ATA B cells increase in PBL and strongly develop lymphomas in aging mice that feature splenomegaly and mLN hyperplasia with heightened expression of CD11b, IL-10, and activated Stat3. At the adult stage, ATA B cells were normally present in the mantle zone area, including in intestine. Furthermore, frequent association with mLN hyperplasia suggests the influence by intestinal microenvironment on lymphoma development. When cyclin D1 was overexpressed by the Eμ-cyclin D1 transgene, ATA B cells progressed to further diffused lymphoma in aged mice, including in various lymph nodes with accumulation of IgM hi IgD lo CD5 + CD23 - CD43 + cells, resembling aggressive human mantle cell lymphoma. Thus, our findings reveal that early generated B cells, as an outcome of B-1 cell development, can progress to become lymphocytosis, lymphoma, and mantle cell lymphoma-like neoplasia in aged mice. Copyright © 2018 by The American Association of Immunologists, Inc.

A constitutive model accounting for strain ageing effects on work-hardening. Application to a C-Mn steel

NASA Astrophysics Data System (ADS)

Ren, Sicong; Mazière, Matthieu; Forest, Samuel; Morgeneyer, Thilo F.; Rousselier, Gilles

2017-12-01

One of the most successful models for describing the Portevin-Le Chatelier effect in engineering applications is the Kubin-Estrin-McCormick model (KEMC). In the present work, the influence of dynamic strain ageing on dynamic recovery due to dislocation annihilation is introduced in order to improve the KEMC model. This modification accounts for additional strain hardening rate due to limited dislocation annihilation by the diffusion of solute atoms and dislocation pinning at low strain rate and/or high temperature. The parameters associated with this novel formulation are identified based on tensile tests for a C-Mn steel at seven temperatures ranging from 20 °C to 350 °C. The validity of the model and the improvement compared to existing models are tested using 2D and 3D finite element simulations of the Portevin-Le Chatelier effect in tension.

Classic debates in selective attention: early vs late, perceptual load vs dilution, mean RT vs measures of capacity.

PubMed

Nelson, Michael D; Crisostomo, Marisa; Khericha, Alifiya; Russo, Francis; Thorne, Gary L

2012-01-01

We briefly summarize two important debates regarding selective attention (early vs late selection; perceptual load vs distractor dilution). Also, we report the results of an attempt to replicate Lavie (1995, Journal of Experimental Psychology: Human Perception and Performance 21 451-468). We suggest that measures capable of characterizing the capacity of information processing systems (compared to reporting only mean reaction time) could add great clarity to this literature.

Diagnostic and prognostic value of right ventricular strain in patients with pulmonary arterial hypertension and relatively preserved functional capacity studied with echocardiography and magnetic resonance.

PubMed

da Costa Junior, Augusto Alberto; Ota-Arakaki, Jaquelina Sonoe; Ramos, Roberta Pulcheri; Uellendahl, Marly; Mancuso, Frederico José Neves; Gil, Manuel Adan; Fischer, Cláudio Henrique; Moises, Valdir Ambrosio; de Camargo Carvalho, Antonio Carlos; Campos, Orlando

2017-01-01

Right ventricular (RV) dysfunction harbingers adverse prognosis in pulmonary arterial hypertension (PAH). Although conventional two-dimensional echocardiography (2DE) is limited for RV systolic function quantitation, RV strain can be a useful tool. The diagnostic and prognostic impact of 2DE speckle-tracking RV longitudinal strain was evaluated, including other 2DE systolic indexes, in a group of PAH patients without severe impairment of functional capacity, chronic pulmonary thromboembolism or left ventricular dysfunction. Sixty-six group I PAH patients, 67 % NYHA functional class I or II (none in IV) were studied by 2DE to obtain: RV fractional area change, tricuspid annular plane systolic excursion, RV myocardial performance index, tissue Doppler tricuspid annulus systolic velocity. Global, free wall (RVFreeWSt) and septal RV longitudinal systolic strain were obtained. RV ejection fraction by cardiac magnetic resonance (CMR-RVEF) was also assessed. All patients were followed up to 3.9 years (mean 3.3 years). Combined endpoints were hospitalization for worsening PAH or cardiovascular death. Among all the 2DE indexes of RV systolic function, RVFreeWSt exhibited the best correlation with CMR-RVEF (r = 0.83; p < 0.005). Combined endpoints occurred in 15 (22.7 %) patients (6 hospitalizations and 9 deaths). Multivariate analysis identified RVFreeWSt ≤-14 % as the only 2DE independent variable associated with combined endpoints [HR 4.66 (1.25-17.37); p < 0.05]. We conclude that RVFreeWSt may be a suitable non-geometric 2DE surrogate of CMR-RVEF in PAH patients, constituting a powerful independent predictor of long-term outcome in this cohort with relatively preserved functional capacity.

Timing of strain localization in high-pressure low-temperature shear zones: The argon isotopic record

NASA Astrophysics Data System (ADS)

Laurent, Valentin; Scaillet, Stéphane; Jolivet, Laurent; Augier, Romain

2017-04-01

The complex interplay between rheology, temperature and deformation profoundly influences how crustal-scale shear zones form and then evolve across a deforming lithosphere. Understanding early exhumation processes in subduction zones requires quantitative age constraints on the timing of strain localization within high-pressure shear zones. Using both the in situ laser ablation and conventional step-heating 40Ar/39Ar dating (on phengite single grains and populations) methods, this study aims at quantifying the duration of ductile deformation and the timing of strain localization within HP-LT shear zones of the Cycladic Blueschist Unit (CBU, Greece). The rate of this progressive strain localization is unknown, and in general, poorly known in similar geological contexts. Critical to retrieve realistic estimates of rates of strain localization during exhumation, dense 40Ar/39Ar age transects were sampled along shear zones recently identified on Syros and Sifnos islands. There, field observations suggest that deformation progressively localized downward in the CBU during exhumation. In parallel, these shear zones are characterized by different degrees of retrogression from blueschist-facies to greenschist-facies P-T conditions overprinting eclogite-facies record throughout the CBU. Results show straightforward correlations between the degree of retrogression, the finite strain intensity and 40Ar/39Ar ages; the most ductilely deformed and retrograded rocks yielded the youngest 40Ar/39Ar ages. The possible effects of strain localization during exhumation on the record of the argon isotopic system in HP-LT shear zones are addressed. Our results show that strain has localized in shear zones over a 30 Ma long period and that individual shear zones evolve during 7-15 Ma. We also discuss these results at small-scale to see whether deformation and fluid circulations, channelled within shear bands, can homogenize chemical compositions and reset the 40Ar/39Ar isotopic record

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.

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.

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…

Automatic segmentation of the hippocampus for preterm neonates from early-in-life to term-equivalent age.

PubMed

Guo, Ting; Winterburn, Julie L; Pipitone, Jon; Duerden, Emma G; Park, Min Tae M; Chau, Vann; Poskitt, Kenneth J; Grunau, Ruth E; Synnes, Anne; Miller, Steven P; Mallar Chakravarty, M

2015-01-01

The hippocampus, a medial temporal lobe structure central to learning and memory, is particularly vulnerable in preterm-born neonates. To date, segmentation of the hippocampus for preterm-born neonates has not yet been performed early-in-life (shortly after birth when clinically stable). The present study focuses on the development and validation of an automatic segmentation protocol that is based on the MAGeT-Brain (Multiple Automatically Generated Templates) algorithm to delineate the hippocampi of preterm neonates on their brain MRIs acquired at not only term-equivalent age but also early-in-life. First, we present a three-step manual segmentation protocol to delineate the hippocampus for preterm neonates and apply this protocol on 22 early-in-life and 22 term images. These manual segmentations are considered the gold standard in assessing the automatic segmentations. MAGeT-Brain, automatic hippocampal segmentation pipeline, requires only a small number of input atlases and reduces the registration and resampling errors by employing an intermediate template library. We assess the segmentation accuracy of MAGeT-Brain in three validation studies, evaluate the hippocampal growth from early-in-life to term-equivalent age, and study the effect of preterm birth on the hippocampal volume. The first experiment thoroughly validates MAGeT-Brain segmentation in three sets of 10-fold Monte Carlo cross-validation (MCCV) analyses with 187 different groups of input atlases and templates. The second experiment segments the neonatal hippocampi on 168 early-in-life and 154 term images and evaluates the hippocampal growth rate of 125 infants from early-in-life to term-equivalent age. The third experiment analyzes the effect of gestational age (GA) at birth on the average hippocampal volume at early-in-life and term-equivalent age using linear regression. The final segmentations demonstrate that MAGeT-Brain consistently provides accurate segmentations in comparison to manually

Automatic segmentation of the hippocampus for preterm neonates from early-in-life to term-equivalent age

PubMed Central

Guo, Ting; Winterburn, Julie L.; Pipitone, Jon; Duerden, Emma G.; Park, Min Tae M.; Chau, Vann; Poskitt, Kenneth J.; Grunau, Ruth E.; Synnes, Anne; Miller, Steven P.; Mallar Chakravarty, M.

2015-01-01

Introduction The hippocampus, a medial temporal lobe structure central to learning and memory, is particularly vulnerable in preterm-born neonates. To date, segmentation of the hippocampus for preterm-born neonates has not yet been performed early-in-life (shortly after birth when clinically stable). The present study focuses on the development and validation of an automatic segmentation protocol that is based on the MAGeT-Brain (Multiple Automatically Generated Templates) algorithm to delineate the hippocampi of preterm neonates on their brain MRIs acquired at not only term-equivalent age but also early-in-life. Methods First, we present a three-step manual segmentation protocol to delineate the hippocampus for preterm neonates and apply this protocol on 22 early-in-life and 22 term images. These manual segmentations are considered the gold standard in assessing the automatic segmentations. MAGeT-Brain, automatic hippocampal segmentation pipeline, requires only a small number of input atlases and reduces the registration and resampling errors by employing an intermediate template library. We assess the segmentation accuracy of MAGeT-Brain in three validation studies, evaluate the hippocampal growth from early-in-life to term-equivalent age, and study the effect of preterm birth on the hippocampal volume. The first experiment thoroughly validates MAGeT-Brain segmentation in three sets of 10-fold Monte Carlo cross-validation (MCCV) analyses with 187 different groups of input atlases and templates. The second experiment segments the neonatal hippocampi on 168 early-in-life and 154 term images and evaluates the hippocampal growth rate of 125 infants from early-in-life to term-equivalent age. The third experiment analyzes the effect of gestational age (GA) at birth on the average hippocampal volume at early-in-life and term-equivalent age using linear regression. Results The final segmentations demonstrate that MAGeT-Brain consistently provides accurate segmentations

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…

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…

Oxidative Capacity Predicted Using Photochemical Age Approximation from SAMBBA Airborne Observations in the Amazon Rainforest

NASA Astrophysics Data System (ADS)

dos Santos, F. C.; Longo, K.; Guenther, A. B.; Freitas, S. R.; Moreira, D. S.; Flávio, L.; Braz, R.; Oram, D.; Lee, J. D.; Bauguitte, S.

2016-12-01

Emitted by vegetation, isoprene (2-methyl-1,3-butadiene) is the most abundant non-methane hydrocarbons, with an annual global emission calculated ranging from 440 to 660Tg carbon, depending on the driving variables like temperature, solar radiation, leaf area index and plant functional type. It is estimated, for example, that the natural compounds like isoprene and terpenes present in the troposphere are about 90% and 50%, respectively, removed from the atmosphere by oxidation performed by hydroxyl radical (OH). Furthermore, the oxidation products of isoprene may contribute to secondary organic aerosol (SOA) formation, affecting the climate and altering the properties and lifetimes of clouds. Considering the importance of these emissions and the hydroxyl radical reaction in the atmosphere, the SAMBBA (South American Biomass Burning Analysis) experiment, which occurred during the dry season (September 2012) in the Amazon Rainforest, provided information about the chemical composition of the atmosphere through airborne observations. Although primarily focused on biomass burning flights, the SAMBBA project carried out other flights providing indirect oxidative capacity data in different environments: natural emission dominated flights and biomass-burning flights with fresh plumes and aged plumes. In this study, we evaluate the oxidative capacity of the Amazon rainforest in different environments, both for the unpolluted and biomass-burning disturbed atmosphere using the ratio [MVK + MACR]/[Isoprene]. Beyond that, we propose an improvement on the formulation of indirect OH density calculation, using the photochemical aging [O3]/[CO] as a parameter. During the day (11am-8pm - local time), the [OH] values for natural emission flights (8.1 x 106 molecules/cm3) and biomass-burning (9.4 x 106 molecules/cm3) are comparable with GABRIEL-2015 field campaign along Guyanas tropical rainforest and suggest that biomass-burning increase the oxidative capacity around 18% in average

The relationship between functional capacity and community responsibilities in middle-aged and older Latinos of Mexican origin with chronic psychosis.

PubMed

Cardenas, Veronica; Mausbach, Brent T; Barrio, Concepcion; Bucardo, Jesus; Jeste, Dilip; Patterson, Thomas

2008-01-01

The purpose of this study was to examine the relationship between scores on the UCSD Performance-based Skills Assessment (UPSA), a performance-based measure of functional capacity, and level of patient community responsibilities (i.e., work for pay; volunteer work; attend school; household duties) in a Latino sample. Participants were 58 middle-aged and older Latinos of Mexican origin (mean age=48.8 years) with a diagnosis of schizophrenia or schizoaffective disorder. We conducted an analysis of covariance (ANCOVA), controlling for age, symptoms of psychosis, and participant language, to determine if greater participation in community responsibilities was associated with higher functional capacity, as measured by the UPSA. Results indicated significant group differences in UPSA scores (F=5.11, df=2, 51; p=.009), with patients reporting only a single community responsibility having significantly higher UPSA scores than those reporting zero community responsibilities (p=.016) and those reporting two responsibilities scoring significantly higher than those reporting zero community responsibility (p=.008). There were no differences found between those reporting one and those reporting two community responsibilities (p=.256). In contrast, no group differences were observed on the Dementia Rating Scale, a global measure of cognitive functioning (F=2.14, df=2, 51; p=.128). These results provide initial support for the validity of the UPSA in Latino patients of Mexican origin, and suggest that improvement in functional capacity (i.e., UPSA scores) may be associated with increased capacity for greater community involvement in this population.

The Relationship between Functional Capacity and Community Responsibilities in Middle-aged and Older Latinos of Mexican Origin with Chronic Psychosis

PubMed Central

Cardenas, Veronica; Mausbach, Brent T.; Barrio, Concepcion; Bucardo, Jesus; Jeste, Dilip; Patterson, Thomas

2008-01-01

The purpose of this study was to examine the relationship between scores on the UCSD Performance-based Skills Assessment (UPSA), a performance-based measure of functional capacity, and level of patient community responsibilities (i.e., work for pay; volunteer work; attend school; household duties) in a Latino sample. Participants were 58 middle-aged and older Latinos of Mexican origin (mean age = 48.8 years) with a diagnosis of schizophrenia or schizoaffective disorder. We conducted an analysis of covariance (ANCOVA), controlling for age, symptoms of psychosis, and participant language, to determine if greater participation in community responsibilities was associated with higher functional capacity, as measured by the UPSA. Results indicated significant group differences in UPSA scores (F = 5.11, df = 2,51; p = .009), with patients reporting only a single community responsibility having significantly higher UPSA scores than those reporting zero community responsibilities (p = .016) and those reporting two responsibilities scoring significantly higher than those reporting zero community responsibility (p = .008). There were no differences found between those reporting one and those reporting two community responsibilities (p= .256). In contrast, no group differences were observed on the Dementia Rating Scale, a global measure of cognitive functioning (F = 2.14, df = 2,51; p = .128). These results provide initial support for the validity of the UPSA in Latino patients of Mexican origin, and suggest that improvement in functional capacity (i.e., UPSA scores) may be associated with increased capacity for greater community involvement in this population. PMID:17936585

Antecedents of cell aging research.

PubMed

Hayflick, L

1989-01-01

Our observation that normal human and animal cells have a limited capacity to divide and function in vitro overturned a dogma held since the turn of the century. The dogma held that cultured normal cells are immortal and gerontologists interpreted this to mean that aging, therefore, could not be the result of intracellular events. We concluded that longevity and aging do result from intracellular events, and, in the subsequent 30 years, the validity of our finding has been widely confirmed. Other major findings have been made: (a) The number of population doublings and functional events that a cultured normal cell can undergo is inversely proportional to donor age and, probably, directly proportional to species longevity; (b) the limit on cell division and function also occurs in vivo when normal cells are transplanted seriatim; (c) as cell doublings or functional events reach their limit, changes occur in hundreds of variables from the molecular to the whole cell. Most importantly, many of these changes are identical to those seen in intact humans and animals as they age; (d) WI-38, the first widely distributed normal human cell strain has retained its memory of population doubling level during 27 years of cryogenic storage. This is the longest time that any normal human cell has ever been preserved. Evidence that longevity is determined by genetic events is overwhelming but evidence that age changes are the result of gene expression is not. Normal age changes must be distinguished from disease. Because few feral animals ever become old, natural selection could not have favored the development of a genetically programmed aging process. In the 2 or 3 million years of human existence, too few old humans existed to have provided a selective advantage favoring the development of a genetic program that would determine age changes. The selective advantage of maintaining physiological vigor for as long as possible in order to insure maximum reproductive success may be

Cognitive aging on latent constructs for visual processing capacity: a novel structural equation modeling framework with causal assumptions based on a theory of visual attention.

PubMed

Nielsen, Simon; Wilms, L Inge

2014-01-01

We examined the effects of normal aging on visual cognition in a sample of 112 healthy adults aged 60-75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive aging affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modeling (SEM; Model 2), informed by functional structures that were modeled with path analyses in SEM (Model 1). The results show that aging effects were selective to measures of visual processing speed compared to visual short-term memory (VSTM) capacity (Model 2). These results are consistent with some studies reporting selective aging effects on processing speed, and inconsistent with other studies reporting aging effects on both processing speed and VSTM capacity. In the discussion we argue that this discrepancy may be mediated by differences in age ranges, and variables of demography. The study demonstrates that SEM is a sensitive method to detect cognitive aging effects even within a narrow age-range, and a useful approach to structure the relationships between measured variables, and the cognitive functional foundation they supposedly represent.

Biodiversity of mannose-specific adhesion in Lactobacillus plantarum revisited: strain-specific domain composition of the mannose-adhesin.

PubMed

Gross, G; Snel, J; Boekhorst, J; Smits, M A; Kleerebezem, M

2010-03-01

Recently, we have identified the mannose-specific adhesin encoding gene (msa) of Lactobacillus plantarum. In the current study, structure and function of this potentially probiotic effector gene were further investigated, exploring genetic diversity of msa in L. plantarum in relation to mannose adhesion capacity. The results demonstrate that there is considerable variation in quantitative in vitro mannose adhesion capacity, which is paralleled by msa gene sequence variation. The msa genes of different L. plantarum strains encode proteins with variable domain composition. Construction of L. plantarum 299v mutant strains revealed that the msa gene product is the key-protein for mannose adhesion, also in a strain with high mannose adhering capacity. However, no straightforward correlation between adhesion capacity and domain composition of Msa in L. plantarum could be identified. Nevertheless, differences in Msa sequences in combination with variable genetic background of specific bacterial strains appears to determine mannose adhesion capacity and potentially affects probiotic properties. These findings exemplify the strain-specificity of probiotic characteristics and illustrate the need for careful and molecular selection of new candidate probiotics.

Effects of domain knowledge, working memory capacity, and age on cognitive performance: an investigation of the knowledge-is-power hypothesis.

PubMed

Hambrick, David Z; Engle, Randall W

2002-06-01

Domain knowledge facilitates performance in many cognitive tasks. However, very little is known about the interplay between domain knowledge and factors that are believed to reflect general, and relatively stable, characteristics of the individual. The primary goal of this study was to investigate the interplay between domain knowledge and one such factor: working memory capacity. Adults from wide ranges of working memory capacity, age, and knowledge about the game of baseball listened to, and then answered questions about, simulated radio broadcasts of baseball games. There was a strong facilitative effect of preexisting knowledge of baseball on memory performance, particularly for information judged to be directly relevant to the baseball games. However, there was a positive effect of working memory capacity on memory performance as well, and there was no indication that domain knowledge attenuated this effect. That is, working memory capacity contributed to memory performance even at high levels of domain knowledge. Similarly, there was no evidence that domain knowledge attenuated age-related differences (favoring young adults) in memory performance. We discuss implications of the results for understanding proficiency in cognitive domains from an individual-differences perspective. Copyright 2001 Elsevier Science (USA).

Evaluation of left ventricular function by tissue Doppler and speckle-derived strain rate echocardiography after percutaneous ductus closure.

PubMed

Amoogzar, Hamid; Shakiba, Ali Mohammad; Derakhshan, Dorna; Ajami, Gholamhossein; Cheriki, Sirous; Borzouee, Mohammad; Edraki, Mohammad Reza; Mehdizadegan, Nima

2015-01-01

The aim of this study was to evaluate the left ventricular systolic and diastolic function before and after transcatheter percutaneous patent ductus arteriosus (PDA) closure. 21 children (age >6 months old) diagnosed with hemodynamically significant PDA underwent percutaneous PDA closure. Conventional, Doppler and tissue Doppler imaging and speckled-derived strain rate echocardiography were done at pre-closure, 1 day (early) and 1 month (late) post-closure. Mean age of the patients (female/male: 1.3) was 17.54 ± 24.7 months with the mean PDA diameter of 3.6 ± 0.8 mm. Systolic measures (ejection fraction, shortening fraction) reduced significantly early after PDA closure (P < 0.05). After 1 month, both improved significantly; ultimately, after 1 month no change was observed in systolic function measures compared with the pre-closure status. Early and late diastolic flow velocities of mitral (E M and A M) reduced considerably in early and late post-closure time (P < 0.05). Both early tissue Doppler early velocity of lateral mitral annulus (E'M) and early to late velocity ratio (E'M/A'M) of lateral mitral annulus decreased significantly (P = 0.02) in early post-closure. After 1 month, E'M increased considerably. (P = 0.01) but E'M/A'M had an insignificant rise (P > 0.05). E M/E'M ratio did not change in early post-closure but it had a considerable reduction in the subsequent month compared with the pre- and early post-closure (P < 0.001 for both occasions). Global and segmental longitudinal strain measures reduced significantly early after PDA closure (P < 0.05) but it improved remarkably in the subsequent month. Transcatheter PDA closure causes a significant decrease in left ventricular performance early after PDA closure which recovers completely within 1 month. Also PDA size can affect post-closure left ventricular function.

Age Validation in the Long Life Family Study Through a Linkage to Early-Life Census Records

PubMed Central

2013-01-01

Objectives. Studies of health and longevity require accurate age reporting. Age misreporting among older adults in the United States is common. Methods. Participants in the Long Life Family Study (LLFS) were matched to early-life census records. Age recorded in the census was used to evaluate age reporting in the LLFS. The study population was 99% non-Hispanic white. Results. About 88% of the participants were matched to 1910, 1920, or 1930 U.S. censuses. Match success depended on the participant’s education, place of birth, and the number of censuses available to be searched. Age at the time of the interview based on the reported date of birth and early-life census age were consistent for about 89% of the participants, and age consistency within 1 year was found for about 99% of the participants. Discussion. It is possible to match a high fraction of older study participants to their early-life census records when detailed information is available on participants’ family of origin. Such record linkage can provide an important source of information for evaluating age reporting among the oldest old participants. Our results are consistent with recent studies suggesting that age reporting among older whites in the United States appears to be quite good. PMID:23704206

Early determinants of vagal activity at preschool age - With potential dependence on sex.

PubMed

Kühne, Britta; Genser, Bernd; De Bock, Freia

2016-12-01

In children, autonomic nervous function is related to various highly prevalent health problems and might therefore represent an early indicator of ill health. We aimed to investigate the role of early-life exposures and physical activity (PA) as potential determinants of autonomic function at preschool age. We used an existing longitudinal data set of repeated vagal tone measurements (assessed via heart rate recovery (HRR)) and retrospectively assessed early-life exposures in 1052 children (mean age: 59.4months, 47.5% girls) from 52 preschools in Germany recruited from 2008 to 2010. HRR 1min after submaximal exercise served as primary outcome. Through multilevel linear regression analysis adjusted for demographic and socioeconomic factors, we assessed the association between repeatedly measured HRR and pregnancy smoking status, breastfeeding and objectively measured PA. Besides significant regression coefficients for previously described correlates of HRR (sex, age), we could show positive associations of HRR with breastfeeding (six versus zero months: +4.2 beats per minute (BPM), p=0.004) and PA (+1.0BPM for 10min increase of moderate-to-vigorous PA/day, p<0.001). Smoking before and during pregnancy showed no significant association with HRR in the total sample. However, we found interactions between sex and smoking before and during pregnancy as well as between sex and breastfeeding, suggesting significant associations with HRR only in girls. Besides PA, early pre- and postnatal exposures seem to have long-lasting effects on children's autonomic function, still recordable at preschool age. Our data suggest that these effects might be sex-dependent. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Childhood Poverty, Chronic Stress, and Young Adult Working Memory: The Protective Role of Self-Regulatory Capacity

ERIC Educational Resources Information Center

Evans, Gary W.; Fuller-Rowell, Thomas E.

2013-01-01

Prior research shows that childhood poverty as well as chronic stress can damage children's executive functioning (EF) capacities, including working memory. However, it is also clear that not all children suffer the same degree of adverse consequences from risk exposure. We show that chronic stress early in life (ages 9-13) links childhood…

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.

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

Aspirin use and early age-related macular degeneration: a meta-analysis.

PubMed

Kahawita, Shyalle K; Casson, Robert J

2014-02-01

The aim of this review was to evaluate the evidence for an association between Aspirin use and early age-related macular degeneration (ARMD). A literature search was performed in 5 databases with no restrictions on language or date of publication. Four studies involving 10292 individuals examining the association between aspirin and ARMD met the inclusion criteria. Meta-analysis was carried out by Cochrane Collaboration Review Manager 5.2 software (Cochrane Collaboration, Copenhagen, Denmark). The pooled odd ratios showed that Aspirin use was associated with early ARMD (pooled odds ratio 1.43, 95% CI 1.09-1.88). There is a small but statistically significant association between Aspirin use and early ARMD, which may warrant further investigation. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Telomere biology in aging and cancer: early history and perspectives.

PubMed

Hayashi, Makoto T

2018-01-20

The ends of eukaryotic linear chromosomes are protected from undesired enzymatic activities by a nucleoprotein complex called the telomere. Expanding evidence indicates that telomeres have central functions in human aging and tumorigenesis. While it is undoubtedly important to follow current advances in telomere biology, it is also fruitful to be well informed in seminal historical studies for a comprehensive understanding of telomere biology, and for the anticipation of future directions. With this in mind, I here summarize the early history of telomere biology and current advances in the field, mostly focusing on mammalian studies relevant to aging and cancer.

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.

Early exercise-based rehabilitation improves health-related quality of life and functional capacity after acute myocardial infarction: a randomized controlled trial.

PubMed

Peixoto, Thatiana C A; Begot, Isis; Bolzan, Douglas W; Machado, Lais; Reis, Michel S; Papa, Valeria; Carvalho, Antonio C C; Arena, Ross; Gomes, Walter J; Guizilini, Solange

2015-03-01

The purpose of this study was to evaluate the influence of an early cardiac rehabilitation (CR) program on health-related quality of life (HRQL) and functional capacity in patients who recently experienced an acute myocardial infarction (AMI). This program was initiated in the inpatient setting and was followed by an unsupervised outpatient intervention. After the same inpatient care plan, low-risk patients who experienced an AMI were randomized into 2 groups: (1) a control group (CG) (n = 43) entailing usual care and (2) an intervention group (IG) (n = 45) entailing outpatient (unsupervised) CR primarily centered on a progressive walking program. Initially, all patients underwent a supervised exercise program with early mobilization beginning 12 hours after an AMI. On hospital discharge, all patients were classified according to cardiovascular risk. Quality of life was evaluated by the MacNew Heart Disease HRQL questionnaire 30 days after discharge. Functional capacity was determined by a 6-minute walk test (6MWT) distance on the day of inpatient discharge as well as 30 days afterward. The HRQL global score was higher in the IG compared with the CG 30 days after discharge (P < 0.001); physical and emotional domain scores were both significantly higher in the IG (P < 0.001). Furthermore, the IG showed a greater 6MWT distance compared with the CG (P < 0.001). A CR program based on early progressive exercises, initiated by supervised inpatient training and followed by an unsupervised outpatient program, improved HRQL and functional capacity in patients at low cardiovascular risk who recently experienced an AMI. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury

PubMed Central

Røksund, Ola D.; Kristoffersen, Morten; Bogen, Bård E.; Wisnes, Alexander; Engeseth, Merete S.; Nilsen, Ann-Kristin; Iversen, Vegard V.; Mæland, Silje; Gundersen, Hilde

2017-01-01

Aim: Hamstring strain injury is common in soccer. The aim of this study was to evaluate the physical capacity of players who have and have not suffered from hamstring strain injury in a sample of semi-professional and professional Norwegian soccer players in order to evaluate characteristics and to identify possible indications of insufficient rehabilitation. Method: Seventy-five semi-professional and professional soccer players (19 ± 3 years) playing at the second and third level in the Norwegian league participated in the study. All players answered a questionnaire, including one question about hamstring strain injury (yes/no) during the previous 2 years. They also performed a 40 m maximal sprint test, a repeated sprint test (8 × 20 m), a countermovement jump, a maximal oxygen consumption (VO2max) test, strength tests and flexibility tests. Independent sample t-tests were used to evaluate differences in the physical capacity of the players who had suffered from hamstring strain injury and those who had not. Mixed between-within subject's analyses of variance was used to compare changes in speed during the repeated sprint test between groups. Results: Players who reported hamstring strain injury during the previous two years (16%) had a significantly higher drop in speed (0.07 vs. 0.02 s, p = 0.007) during the repeated sprint test, compared to players reporting no previous hamstring strain injury. In addition, there was a significant interaction (groups × time) (F = 3.22, p = 0.002), showing that speed in the two groups changed differently during the repeated sprint test. There were no significant differences in relations to age, weight, height, body fat, linear speed, countermovement jump height, leg strength, VO2max, or hamstring flexibility between the groups. Conclusion: Soccer players who reported hamstring strain injury during the previous 2 years showed significant higher drop in speed during the repeated sprint test compared to players with no hamstring

Isotopic constraints on the age and early differentiation of the Earth.

PubMed

McCulloch, M T

1996-03-01

The Earth's age and early differentiation history are re-evaluated using updated isotopic constraints. From the most primitive terrestrial Pb isotopic compositions found at Isua Greenland, and the Pilbara of Western Australia, combined with precise geochronology of these localities, an age 4.49 +/- 0.02 Ga is obtained. This is interpreted as the mean age of core formation as U/Pb is fractionated due to sequestering of Pb into the Earth's core. The long-lived Rb-Sr isotopic system provides constraints on the time interval for the accretion of the Earth as Rb underwent significant depletion by volatile loss during accretion of the Earth or its precursor planetesimals. A primitive measured 87Sr/86Sr initial ratio of 0.700502 +/- 10 has been obtained for an early Archean (3.46 Ga) barite from the Pilbara Block of Western Australia. Using conservative models for the evolution of Rb/Sr in the early Archean mantle allows an estimate to be placed on the Earth's initial Sr ratio at approximately 4.50 Ga, of 0.69940 +/- 10. This is significantly higher than that measured for the Moon (0.69900 +/- 2) or in the achondrite, Angra dos Reis (0.69894 +/- 2) and for a Rb/Sr ratio of approximately 1/2 of chondrites corresponds to a mean age for accretion of the Earth of 4.48 + /- 0.04 Ga. The now extinct 146Sm-142Nd (T1/2(146)=103 l0(6)yrs) combined with the long-lived 147Sm-143Nd isotopic systematics can also be used to provide limits on the time of early differentiation of the Earth. High precision analyses of the oldest (3.8-3.9 Ga) Archean gneisses from Greenland (Amitsoq and Akilia gneisses), and Canada (Acasta gneiss) do not show measurable (> +/- l0ppm) variations of 142Nd, in contrast to the 33 ppm 142Nd excess reported for an Archean sample. The general lack of 142Nd variations, combined with the presence of highly positive epsilon 143 values (+4.0) at 3.9 Ga, indicates that the record of large-scale Sm/Nd fractionation events was not preserved in the early-Earth from 4

Improvement of phytoremediation of an aged petroleum hydrocarbon-contaminated soil by Rhodococcus erythropolis CD 106 strain.

PubMed

Płociniczak, Tomasz; Fic, Ewa; Pacwa-Płociniczak, Magdalena; Pawlik, Małgorzata; Piotrowska-Seget, Zofia

2017-07-03

The aim of this study was to assess the impact of soil inoculation with the Rhodococcus erythropolis CD 106 strain on the effectiveness of the phytoremediation of an aged hydrocarbon-contaminated [approx. 1% total petroleum hydrocarbon (TPH)] soil using ryegrass (Lolium perenne). The introduction of CD 106 into the soil significantly increased the biomass of ryegrass and the removal of hydrocarbons in planted soil. The fresh weight of the shoots and roots of plants inoculated with CD 106 increased by 49% and 30%, respectively. After 210 days of the experiment, the concentration of TPH was reduced by 31.2%, whereas in the planted, non-inoculated soil, it was reduced by 16.8%. By contrast, the concentration of petroleum hydrocarbon decreased by 18.7% in non-planted soil bioaugmented with the CD 106 strain. The rifampicin-resistant CD 106 strain survived after inoculation into soil and was detected in the soil during the entire experimental period, but the number of CD 106 cells decreased constantly during the enhanced phytoremediation and bioaugmentation experiments. The plant growth-promoting and hydrocarbon-degrading properties of CD 106, which are connected with its long-term survival and limited impact on autochthonous microflora, make this strain a good candidate for improving the phytoremediation efficiency of soil contaminated with hydrocarbons.

Impact of job and marital strain on ambulatory blood pressure results from the double exposure study.

PubMed

Tobe, Sheldon W; Kiss, Alexander; Szalai, John Paul; Perkins, Nancy; Tsigoulis, Michelle; Baker, Brian

2005-08-01

Psychosocial stressors such as job strain and marital stress have been associated with a sustained increase in blood pressure (BP). We evaluated whether job strain and marital cohesion were associated with ambulatory BP in workers with normal or untreated elevated BP using baseline data from the Double Exposure study. The study population included 248 male and female volunteers who were nonmedicated, employed, and living with a significant other, all for a minimum of 6 months. Blood pressure was measured with an ambulatory BP monitor and participants completed a diary that recorded time during work, spousal contact, and sleep. Job strain and marital cohesion were calculated from the Job Content Questionnaire and the Dyadic Adjustment Scale, respectively. Of the subjects, 54.4% were female with a mean age of 50.8 years (6.6, SD). In all, 21.3% reported job strain. Significant assocations were found between 24-h systolic BP (SBP) and alcohol consumption (P = .033), job strain (P = .007), male gender (P = .004), and age (P = .039) and was inversely associated with exercise (P = .037). An interaction between 24-h SBP, job strain, and marital cohesion was found such that greater marital cohesion was associated with lower SBP in subjects with job strain. Psychosocial factors may influence the development of early hypertension. This should be clarified by the cohort phase of the Double Exposure study.

The curvilinear relationship of early-life adversity and successful aging: the mediating role of mental health.

PubMed

Höltge, Jan; Mc Gee, Shauna L; Thoma, Myriam V

2018-02-15

The steeling effect suggests that early-life adversity can have a beneficial impact later in life. However, little is known about its underlying mechanisms and long-term outcomes . The study aimed to examine the role of early-life adversity (ELA) on successful aging, and whether this relationship can be explained by mental and physical health. Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (M age = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted. Significant inverse U-shaped associations were found between ELA and iQoL (β = -.59, p = .005) and between ELA and mental health (β = -.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = -.84, BCa CI [-1.66, -.27]). Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity.

Fetal environment and early age at natural menopause in a British birth cohort study

PubMed Central

Tom, Sarah E.; Cooper, Rachel; Kuh, Diana; Guralnik, Jack M.; Hardy, Rebecca; Power, Chris

2010-01-01

BACKGROUND Early life development may influence the timing of natural menopause through association with size of the initial follicle pool or early follicular loss. This study examines the relationships of birthweight, gestational age and birthweight standardized by gestational age with early menopause in the 1958 British birth cohort study. METHODS Study participants were over 2900 women with data on birthweight, gestational age (obtained at birth), menopausal status at age 44–45 years and potential confounding factors. Logistic regression was used to study relationships of birthweight, gestational age and birthweight standardized by gestational age with post-menopausal status by 44–45 years, with and without adjustments for confounding factors. RESULTS There was a U-shaped association between birthweight and menopausal status at 44–45 years: women at either extremes of birthweight (<2.5 and ≥4.0 kg) had increased odds of post-menopausal status compared with those weighing 3.0–3.49 kg [odds ratio (OR) = 1.91, 95% confidence interval (CI) 1.08, 3.38; 1.81, 95% CI 1.11, 2.97, respectively]. Women with higher birthweight standardized by gestational age (which indicates faster fetal growth rate) also had increased odds of being post-menopausal by 44–45 years (OR for fastest quarter versus second fastest quarter = 1.80; 95% CI 1.16, 2.81). These associations persisted after adjustment for socioeconomic position at birth, adult smoking status and use of oral contraceptives. CONCLUSIONS These findings suggest that variations in fetal environment may be associated with the timing of menopause. Given that extremes of birthweight and higher birthweight standardized by gestational age were associated with earlier age at menopause, mechanisms related to these characteristics that also regulate ovarian function should be investigated further. PMID:20047935

Mycobacterium tuberculosis strains induce strain-specific cytokine and chemokine response in pulmonary epithelial cells.

PubMed

Mvubu, Nontobeko E; Pillay, Balakrishna; McKinnon, Lyle R; Pillay, Manormoney

2018-04-01

M. tuberculosis F15/LAM4/KZN has been associated with high transmission rates of drug resistant tuberculosis in the KwaZulu-Natal province of South Africa. The current study elucidated the cytokine/chemokine responses induced by representatives of the F15/LAM4/KZN and other dominant strain families in pulmonary epithelial cells. Multiplex cytokine analyses were performed at 24, 48 and 72h post infection of the A549 pulmonary epithelial cell line with the F15/LAM4/KZN, F28, F11, Beijing, Unique and H37Rv strains at an MOI of ∼10:1. Twenty-three anti- and pro-inflammatory cytokines/chemokines were detected at all-time intervals. Significantly high concentrations of IL-6, IFN-γ, TNF-α and G-CSF at 48h, and IL-8, IFN-γ, TNF-α, G-CSF and GM-CSF at 72h, were induced by the F28 and F15/LAM4/KZN strains, respectively. Lower levels of cytokines/chemokines were induced by either the Beijing or Unique strains at all three time intervals. All strains induced up-regulation of pathogen recognition receptors (PRRs) (TLR3 and TLR5) while only the F15/LAM4/KZN, F11 and F28 strains induced significant differential expression of TLR2 compared to the Beijing, Unique and H37Rv strains. The low induction of cytokines in epithelial cells by the Beijing strain correlates with its previously reported hypervirulent properties. High concentrations of cytokines and chemokines required for early protection against M. tuberculosis infections induced by the F15/LAM4/KZN and F28 strains suggests a lower virulence of these genotypes compared to the Beijing strain. These findings demonstrate the high diversity in host cytokine/chemokine response to early infection of pulmonary epithelial cells by different strains of M. tuberculosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Supporting early career health investigators in Kenya: A qualitative study of HIV/AIDS research capacity building.

PubMed

Daniels, Joseph; Nduati, Ruth; Kiarie, James; Farquhar, Carey

2015-01-01

Strategies to transfer international health research training programs to sub-Saharan African institutions focus on developing cadres of local investigators who will lead such programs. Using a critical leadership theory framework, we conducted a qualitative study of one program to understand how collaborative training and research can support early career investigators in Kenya toward the program transfer goal. We used purposive sampling methods and a semi-structured protocol to conduct in-depth interviews with US (N = 5) and Kenyan (N = 5) independent investigators. Transcripts were coded using a two-step process, and then compared with each other to identify major themes. A limited local research environment, funding needs and research career mentorship were identified as major influences on early career researchers. Institutional demands on Kenyan faculty to teach rather than complete research restricted investigators' ability to develop research careers. This was coupled with lack of local funding to support research. Sustainable collaborations between Kenyan, US and other international investigators were perceived to mitigate these challenges and support early career investigators who would help build a robust local research environment for training. Mutually beneficial collaborations between Kenyan and US investigators developed during training mitigate these challenges and build a supportive research environment for training. In these collaborations, early career investigators learn how to navigate the complex international research environment to build local HIV research capacity. Shared and mutually beneficial resources within international research collaborations are required to support early career investigators and plans to transfer health research training to African institutions.