Building on People's Strengths: Early Childhood in Africa.

ERIC Educational Resources Information Center

Cohen, Ruth; And Others

This report describes early childhood development (ECD) in Africa and the Bernard van Leer Foundation's strategies for early childhood programs in African nations. Chapter 1 examines the context in which Africa's children are growing up, focusing on the hardships that many children face, as well as the efforts made by families, communities, and…

Young Children with Disabilities in Israel: System of Early Intervention Service Delivery

ERIC Educational Resources Information Center

Shulman, Cory; Meadan, Hedda; Sandhaus, Yoram

2012-01-01

This article aims to analyze early intervention programs in Israel according to the Developmental Systems Model (Guralnick, 2001), in an attempt to identify strengths and areas for further development for service delivery for young children with disabilities in Israel. Early intervention in Israel is part of a comprehensive healthcare model…

Ultrasonic Monitoring of Setting and Strength Development of Ultra-High-Performance Concrete.

PubMed

Yoo, Doo-Yeol; Shin, Hyun-Oh; Yoon, Young-Soo

2016-04-19

In this study, the setting and tensile strength development of ultra-high-performance concrete (UHPC) at a very early age was investigated by performing the penetration resistance test (ASTM C403), as well as the direct tensile test using the newly developed test apparatus, and taking ultrasonic pulse velocity (UPV) measurements. In order to determine the optimum surface treatment method for preventing rapid surface drying of UHPC, four different methods were examined: plastic sheet, curing cover, membrane-forming compound, and paraffin oil. Based on the test results, the use of paraffin oil was found to be the best choice for measuring the penetration resistance and the UPV, and attaching the plastic sheet to the exposed surface was considered to be a simple method for preventing the rapid surface drying of UHPC elements. An S-shaped tensile strength development at a very early age (before 24 h) was experimentally obtained, and it was predicted by a power function of UPV. Lastly, the addition of shrinkage-reducing and expansive admixtures resulted in more rapid development of penetration resistance and UPV of UHPC.

Developing an Asteroid Rotational Theory

NASA Astrophysics Data System (ADS)

Geis, Gena; Williams, Miguel; Linder, Tyler; Pakey, Donald

2018-01-01

The goal of this project is to develop a theoretical asteroid rotational theory from first principles. Starting at first principles provides a firm foundation for computer simulations which can be used to analyze multiple variables at once such as size, rotation period, tensile strength, and density. The initial theory will be presented along with early models of applying the theory to the asteroid population. Early results confirm previous work by Pravec et al. (2002) that show the majority of the asteroids larger than 200m have negligible tensile strength and have spin rates close to their critical breakup point. Additionally, results show that an object with zero tensile strength has a maximum rotational rate determined by the object’s density, not size. Therefore, an iron asteroid with a density of 8000 kg/m^3 would have a minimum spin period of 1.16h if the only forces were gravitational and centrifugal. The short-term goal is to include material forces in the simulations to determine what tensile strength will allow the high spin rates of asteroids smaller than 150m.

Reliable early opening strength for concrete pavements and patch work

DOT National Transportation Integrated Search

2016-06-01

Early opening strengths for concrete vary greatly around the country for many different reasons. DOTD specifies early opening strengths and will benefit from understanding the latest thinking and practices adopted by similar agencies. Knowing the bes...

Parameters of tensile strength, elongation, and tenacity of 70mm IIaO spectroscopic film

NASA Technical Reports Server (NTRS)

Hammond, Ernest C., Jr.; Peters, Kevin A.

1989-01-01

The 70mm IIaO spectroscopic film was tested to determine its tensile strength, elongation, and breaking strength, using an Instron (strength and compression) 4201 Test Instrument. These data provide information leading to the upper and lower limits of the above parameters for 70mm IIaO spectroscopic film. This film will be developed by a commercial developing machine after the Ultraviolet Telescope Space Shuttle Mission returns to the Earth in the early 1990's; thus, it is necessary to understand these force parameters. Several test strips of approximately 200mm in length were used. The results indicate that when a stress load of 100 kg was applied, the film elongated approximately 1.06mm and the break strength was 19.45 kilograms.

Identifying and Enhancing the Strengths of Gifted Learners, K-8: Easy-to-Use Activities and Lessons

ERIC Educational Resources Information Center

Maccagnano, Ann Marie

2007-01-01

Educators can identify children's strengths early on and gain insight into each student's unique abilities by using the numerous ideas and informal assessments in this exciting guide. Gifted and talented specialist Ann Maccagnano offers K-8 teachers challenging activities and engaging lessons to develop and nurture gifted learners' talents.…

Early Childhood Education in Saudi Arabia: Report

ERIC Educational Resources Information Center

Rabaah, Alqassem; Doaa, Dashash; Asma, Alzahrani

2016-01-01

This paper reviewed the development of early childhood education (ECE) in Saudi Arabia and its strengths and weaknesses. The paper discusses the contextual background of Saudi Arabia, including its geography, demographics, social system, economy, political system and religion. In addition, the paper investigated the education system at large in…

Early Career Teacher Professional Development: Bridging Simulation Technology with Evidence-Based Behavior Management

ERIC Educational Resources Information Center

Shernoff, Elisa; Frazier, Stacy; Lisetti, Christine; Buche, Cedric; Lunn, Stephanie; Brown, Claire; Delmarre, Alban; Chou, Tommy; Gabbard, Joseph; Morgan, Emily

2018-01-01

Early career teachers working in high poverty schools face of overwhelming challenges navigating disruptive behaviors with studies highlighting behavior problems as one of the strongest predictors of turnover (Ingersoll & Smith, 2003). Simulation-based technology leverages important pedagogical strengths (e.g., realistic training context,…

Removing obstacles for pavement cost reduction by examining early age opening requirements : material properties.

DOT National Transportation Integrated Search

2015-08-01

The risk of cracking in a concrete pavement that is opened to traffic at early ages is related to the maximum tensile stress, , that : develops in the pavement and its relationship to the measured, age dependent, flexural strength of a beam, fr . T...

Development of high-performance blended cements

NASA Astrophysics Data System (ADS)

Wu, Zichao

2000-10-01

This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

Microstructural Developments Leading to New Advanced High Strength Sheet Steels: A Historical Assessment of Critical Metallographic Observations

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

Matlock, David K; Thomas, Larrin S; Taylor, Mark D

In the past 30+ years significant advancements have been made in the development of higher strength sheet steels with improved combinations of strength and ductility that have enabled important product improvements leading to safer, lighter weight, and more fuel efficient automobiles and in other applications. Properties of the primarily low carbon, low alloy steels are derived through careful control of time-temperature processing histories designed to produce multiphase ferritic based microstructures that include martensite and other constituents including retained austenite. The basis for these developments stems from the early work on dual-phase steels which was the subject of much interest. Inmore » response to industry needs, dual-phase steels have evolved as a unique class of advanced high strength sheet steels (AHSS) in which the thermal and mechanical processing histories have been specifically designed to produce constituent combinations for the purpose of simultaneously controlling strength and deformation behavior, i.e. stress-strain curve shapes. Improvements continue as enhanced dual-phase steels have recently been produced with finer microstructures, higher strengths, and better overall formability. Today, dual phase steels are the primary AHSS products used in vehicle manufacture, and several companies have indicated that the steels will remain as important design materials well into the future. In this presentation, fundamental results from the early work on dual-phase steels will be reviewed and assessed in light of recent steel developments. Specific contributions from industry/university cooperative research leading to product improvements will be highlighted. The historical perspective provided in the evolution of dual-phase steels represents a case-study that provides important framework and lessons to be incorporated in next generation AHSS products.« less

The Relationship between Teacher Qualification and the Quality of the Early Childhood Care and Learning Environment. Campbell Systematic Reviews 2017:1

ERIC Educational Resources Information Center

Manning, Matthew; Garvis, Susanne; Fleming, Christopher; Wong, Gabriel T. W.

2017-01-01

Poor quality early childhood education and care (ECEC) can be detrimental to the development of children as it could lead to poor social, emotional, educational, health, economic, and behavioural outcomes. The lack of consensus as to the strength of the relationship between teacher qualification and the quality of the early childhood learning…

THIGH MUSCLE CROSS-SECTIONAL AREAS AND STRENGTH IN KNEES WITH EARLY VS KNEES WITHOUT RADIOGRAPHIC KNEE OSTEOARTHRITIS: A BETWEEN-KNEE, WITHIN-PERSON COMPARISON

PubMed Central

Ruhdorfer, AS; Dannhauer, T; Wirth, W; Cotofana, S; Roemer, F; Nevitt, M; Eckstein, F

2014-01-01

Objective To compare cross-sectional and longitudinal side-differences in thigh muscle anatomical cross-sectional areas (ACSAs), muscle strength, and specific strength (strength/ACSA), between knees with early radiographic change vs. knees without radiographic knee osteoarthritis (RKOA), in the same person. Design 55 (of 4796) Osteoarthritis Initiative participants fulfilled the inclusion criteria of early RKOA in one limb (definite tibiofemoral osteophytes; no radiographic joint space narrowing [JSN]) vs. no RKOA (no osteophyte; no JSN) in the contralateral limb. ACSAs of the thigh muscles and quadriceps heads were determined using axial MRIs at 33%/30% femoral length (distal to proximal). Isometric extensor and flexor muscle strength were measured (Good Strength Chair). Baseline quadriceps ACSA and extensor (specific) strength represented the primary analytic focus, and two-year changes of quadriceps ACSAs the secondary focus. Results No statistically significant side-differences in quadriceps (or other thigh muscle) ACSAs, muscle strength, or specific strength were observed between early RKOA vs. contralateral limbs without RKOA (p≥0.44), neither in men nor in women. The two-year reduction in quadriceps ACSA in limbs with early RKOA was −0.9±6% (mean ± standard deviation) vs. −0.5±6% in limbs without RKOA (statistical difference p=0.85). Conclusion Our results do not provide evidence that early unilateral radiographic changes, i.e. presence of osteophytes, are associated with cross-sectional or longitudinal differences in quadriceps muscle status compared with contralateral knees without RKOA. At the stage of early unilateral RKOA there thus appears to be no clinical need for countervailing a potential dys-balance in quadriceps ACSAs and strength between both knees. PMID:25278072

The puzzling interpretation of NIR indices: The case of NaI2.21

NASA Astrophysics Data System (ADS)

Röck, B.; Vazdekis, A.; La Barbera, F.; Peletier, R. F.; Knapen, J. H.; Allende-Prieto, C.; Aguado, D. S.

2017-11-01

We present a detailed study of the Na I line strength index centred in the K band at 22 100 Å (NaI2.21 hereafter) relying on different samples of early-type galaxies. Consistent with previous studies, we find that the observed line strength indices cannot be fit by state-of-the-art scaled-solar stellar population models, even using our newly developed models in the near infrared (NIR). The models clearly underestimate the large NaI2.21 values measured for most early-type galaxies. However, we develop an Na-enhanced version of our newly developed models in the NIR, which - together with the effect of a bottom-heavy initial mass function - yield NaI2.21 indices in the range of the observations. Therefore, we suggest a scenario in which the combined effect of [Na/Fe] enhancement and a bottom-heavy initial mass function are mainly responsible for the large NaI2.21 indices observed for most early-type galaxies. To a smaller extent, also [C/Fe] enhancement might contribute to the large observed NaI2.21 values.

Falls, sarcopenia and growth in early life

PubMed Central

Sayer, Avan Aihie; Syddall, Holly E; Martin, Helen J; Dennison, Elaine M; Anderson, Frazer H; Cooper, Cyrus

2007-01-01

Recent studies have shown that people with poor early growth have an increased risk of sarcopenia. Sarcopenia is an important risk factor for falls but it is not known whether poor early growth is related to falls. We investigated this in the Hertfordshire Cohort Study where 2148 participants completed a falls history. Grip strength was used as a marker of sarcopenia. Birth weight, weight at one year and conditional infant growth were analysed in relation to falls history. The prevalence of any fall in the last year was 14.3% for men and 22.5% for women. Falls in the last year were inversely related to adult grip strength, height and walking speed in men and women as well as to lower conditional infant growth in men (OR 1.27 [95% CI 1.04, 1.56] per SD decrease in conditional infant growth, p=0.02). This association was attenuated after adjustment for grip strength. Our findings support an association between poor early growth and falls in older men which appears to be mediated partly through sarcopenia. The lack of relationship with birth weight suggests that postnatal rather than prenatal influences on muscle growth and development may be important for risk of falls in later life. PMID:16905644

Role of cognitive theory in the study of learning disability in mathematics.

PubMed

Geary, David C

2005-01-01

Gersten, Jordan, and Flojo (in this issue) provide the beginnings of an essential bridge between basic research on mathematical disabilities (MD) in young children and the application of this research for the early identification and remediation of these forms of learning disability. As they acknowledge, the field of MD is in the early stages of development, and thus recommendations regarding identification measures and remedial techniques must be considered preliminary. I discuss the importance of maintaining a tight link between theoretical and empirical research on children's developing numerical, arithmetical, and mathematical competencies and future research on learning disabilities in mathematics. This link will provide the foundation for transforming experimental procedures into assessment measures, understanding the cognitive strengths and weaknesses of children with these forms of learning disability, and developing remedial approaches based on the pattern of cognitive strengths and weaknesses for individual children.

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

NASA Technical Reports Server (NTRS)

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

1985-01-01

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

Cadmium Alternatives for High-Strength Steel

DTIC Science & Technology

2011-09-22

coating small parts, a barrel coater was developed which originally coated 75 pounds of steel fasteners during a coating run. By the early 1980s...technique to define design allowables. Other design authorities rely more heavily on axial tension-tension or tension- compression data. Some axial ...FINAL REPORT Cadmium Alternatives for High-Strength Steel WP-200022 Steven A. Brown Naval Air Warfare Center Aircraft Division Patuxent

An experimental method to simulate incipient decay of wood basidiomycete fungi

Treesearch

Simon Curling; Jerrold E. Winandy; Carol A. Clausen

2000-01-01

At very early stages of decay of wood by basidiomycete fungi, strength loss can be measured from wood before any measurable weight loss. Therefore, strength loss is a more efficient measure of incipient decay than weight loss. However, common standard decay tests (e.g. EN 113 or ASTM D2017) use weight loss as the measure of decay. A method was developed that allowed...

The Effects of Short-Term Ski Trainings on Dynamic Balance Performance and Vertical Jump in Adolescents

ERIC Educational Resources Information Center

Camliguney, Asiye Filiz

2013-01-01

Skiing is a sport where balance and strength are critical and which can be practiced actively especially from early years to old age. The purpose of this study is to examine the effect of a 5-day training of skiing skills on dynamic balance performance and development of vertical jump strength in adolescents. Sixteen adolescent volunteers who do…

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

ERIC Educational Resources Information Center

Fenton, Angela

2013-01-01

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

Rigidity in Gender-Typed Behaviors in Early Childhood: A Longitudinal Study of Ethnic Minority Children

ERIC Educational Resources Information Center

Halim, May Ling; Ruble, Diane; Tamis-LeMonda, Catherine; Shrout, Patrick E.

2013-01-01

A key prediction of cognitive theories of gender development concerns developmental trajectories in the relative strength or rigidity of gender typing. To examine these trajectories in early childhood, 229 children (African American, Mexican American, and Dominican American) were followed annually from age 3 to 5 years, and gender-stereotypical…

Highway concrete pavement technology development and testing : volume IV, field evaluation of Strategic Highway Research Program (SHRP) C-206 test sites (early opening of full-depth pavement repairs).

DOT National Transportation Integrated Search

2006-08-01

The objective of this study was to monitor and evaluate the performance of experimental full-depth repairs made with high-early-strength (HES) materials placed under Strategic Highway Research Program (SHRP) project C-206, Optimization of Highway Con...

Tracking Club Sport Participation from Childhood to Early Adulthood

ERIC Educational Resources Information Center

Richards, Rosalina; Williams, Sheila; Poulton, Richie; Reeder, Anthony I.

2007-01-01

This study examined the strength of tracking sport participation from childhood to early adulthood among the Dunedin Multidisciplinary Health and Development Study cohort. Participation in sport, dance, or gymnastics as part of a club or group (outside of school) was assessed at ages 7, 9, 15, 18, and 21 years. In addition to the traditionally…

Detection of early symptoms of cumulativetrauma disorders among mothers of handicapped children: a pilot study

PubMed Central

Kinali, Gulsah; Üçsular, Ferda Dokuztuğ

2018-01-01

[Purpose] This study aimed to establish a scientific and clinical basis for the development of a method for the early diagnosis of cumulative trauma disorders experienced by mothers of disabled children. [Subjects and Methods] Ten volunteer mothers who came to a rehabilitation centre for the treatment of their children were included in this study. Surface electromyography measurements were taken during maximum isometric contraction through the extensor muscle motor point of the wrist of the mothers, and hand grip strength was measured. [Results] In the electromyography measurements, the mean electromyogram signal value obtained from the wrist extensor muscle motor point of the mothers of the healthy children was 0.3 ± 0.08 mV and the crude handgrip strength was 28.5 ± 2.08 kg. In mothers of rehabilitated children, the crude hand grip strength was 7.0 ± 1.1 kg, and the mean electromyogram signal value from the extender muscle motor point was 0.1 ± 0.02 mV. There was a significant difference between the mothers with healthy and disabled children with respect to handgrip strength and electromyography. [Conclusion] The result obtained may be important in the development of health protection programs. Further research may lead to the development of protective rehabilitation programs and the improvement of social rights for mothers with disabled children. PMID:29545677

Professional Development. The Evaluation Exchange. Volume 11, Number 4, Winter 2005-2006

ERIC Educational Resources Information Center

DeDeo, Carrie-Anne, Ed.

2006-01-01

This issue hones in on professional development in four key sectors affecting children, youth, and families--K-12 education, early childhood education, child welfare, and youth development. Though these sectors face many of the same professional development challenges, each has its own unique issues, strengths, and goals. The staffing shortage in…

Influence of Exercise and Training on Critical Stages of Bone Growth and Development.

PubMed

Klentrou, Panagiota

2016-05-01

Although osteoporosis is considered a geriatric disease, factors affecting bone strength are most influential during child growth and development. This article reviews what is known and still unclear in terms of bone growth, development and adaptation relative to physical activity before and during puberty. Bone is responsive to certain exercise protocols early in puberty and less so in postpubertal years, where bone strength, rather than bone mass, being the outcome of interest. Mechanical loading and high impact exercise promote bone strength. Intense training before and during puberty, however, may negatively affect bone development. Future research should focus on increasing our mechanistic understanding of the manner by which diverse physical stressors alter the integrity of bone. Longitudinal studies that examine the extent to which muscle and bone are comodulated by growth in children are also recommended.

Phase 1 report on the development of predictive model for bridge deck cracking and strength development.

DOT National Transportation Integrated Search

2009-01-01

Early-age cracking, typically caused by drying shrinkage (and often coupled with autogenous and thermal : shrinkage), can have several detrimental effects on long-term behavior and durability. Cracking can also provide : ingress of water that can dri...

High-early-strength high-performance concrete for rapid pavement repair.

DOT National Transportation Integrated Search

2016-01-01

In the construction industry, High Early-Age Strength (HES) concrete was : traditionally regarded as a concrete that achieves a loading strength in matter of days : rather than weeks. However, in the last 10-15 years, this time has been reduced down ...

Sustainable construction: composite use of tyres and ash in concrete.

PubMed

Snelson, D G; Kinuthia, J M; Davies, P A; Chang, S-R

2009-01-01

An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment and pavement) and also in concrete to be used in the construction of the proposed highway. This paper reports on concrete-based construction where concrete blends (using various levels of PFA as partial replacement for Portland cement (PC), and shredded waste tyres (chips 15-20mm) as aggregate replacement) were subjected to unconfined compressive strength tests to establish performance, hence, optimising mix designs. Strength development up to 180 days for the concrete made with PC-PFA blends as binders (PC-PFA concrete), with and without aggregate replacement with tyre chips, is reported. The binary PC-PFA concrete does not have good early strength but tends to improve at longer curing periods. The low early strength observed means that PC-PFA concrete cannot be used for structures, hence, only as low to medium strength applications such as blinding, low-strength foundations, crash barriers, noise reduction barriers, cycle paths, footpaths and material for pipe bedding.

Sustainable construction: Composite use of tyres and ash in concrete

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

Snelson, D.G.; Kinuthia, J.M.; Davies, P.A.

2009-01-15

An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment and pavement) and also in concrete to be used in the construction of the proposed highway. This paper reports on concrete-based construction where concrete blends (using various levels of PFA as partial replacement for Portland cement (PC), and shredded waste tyres (chipsmore » 15-20 mm) as aggregate replacement) were subjected to unconfined compressive strength tests to establish performance, hence, optimising mix designs. Strength development up to 180 days for the concrete made with PC-PFA blends as binders (PC-PFA concrete), with and without aggregate replacement with tyre chips, is reported. The binary PC-PFA concrete does not have good early strength but tends to improve at longer curing periods. The low early strength observed means that PC-PFA concrete cannot be used for structures, hence, only as low to medium strength applications such as blinding, low-strength foundations, crash barriers, noise reduction barriers, cycle paths, footpaths and material for pipe bedding.« less

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

Influence of muscle strength on early mobility in critically ill adult patients: Systematic literature review.

PubMed

Roberson, Audrey R; Starkweather, Angela; Grossman, Catherine; Acevedo, Edmund; Salyer, Jeanne

Muscle strength may be one indicator of readiness to mobilize that can be used to guide decisions regarding early mobility efforts and to progressively advance mobilization. To provide a synthesis of current measures of muscle strength in the assessment of early mobilization in critically ill adult patients who are receiving MV therapy. Research studies conducted between 2000-2015 were identified using PubMed, CINHAL, MEDLINE, and the Cochrane Database of Systematic Reviews databases using the search terms "muscle strength", "intensive care", "mechanical ventilation" and "muscle weakness". Nine articles used manual muscle testing, the Medical Research Council scale and/or hand-held dynamometer to provide objective measures for assessing muscle strength in the critically ill adult patient population. Further research is needed to examine the application of standardized measures of muscle strength for guiding decisions regarding early and progressive advancement of mobility goals in adult ICU patients on MV. Copyright © 2017 Elsevier Inc. All rights reserved.

Early somatosensory processing in individuals at risk for developing psychoses.

PubMed

Hagenmuller, Florence; Heekeren, Karsten; Theodoridou, Anastasia; Walitza, Susanne; Haker, Helene; Rössler, Wulf; Kawohl, Wolfram

2014-01-01

Human cortical somatosensory evoked potentials (SEPs) allow an accurate investigation of thalamocortical and early cortical processing. SEPs reveal a burst of superimposed early (N20) high-frequency oscillations around 600 Hz. Previous studies reported alterations of SEPs in patients with schizophrenia. This study addresses the question whether those alterations are also observable in populations at risk for developing schizophrenia or bipolar disorders. To our knowledge to date, this is the first study investigating SEPs in a population at risk for developing psychoses. Median nerve SEPs were investigated using multichannel EEG in individuals at risk for developing bipolar disorders (n = 25), individuals with high-risk status (n = 59) and ultra-high-risk status for schizophrenia (n = 73) and a gender and age-matched control group (n = 45). Strengths and latencies of low- and high-frequency components as estimated by dipole source analysis were compared between groups. Low- and high-frequency source activity was reduced in both groups at risk for schizophrenia, in comparison to the group at risk for bipolar disorders. HFO amplitudes were also significant reduced in subjects with high-risk status for schizophrenia compared to healthy controls. These differences were accentuated among cannabis non-users. Reduced N20 source strengths were related to higher positive symptom load. These results suggest that the risk for schizophrenia, in contrast to bipolar disorders, may involve an impairment of early cerebral somatosensory processing. Neurophysiologic alterations in schizophrenia precede the onset of initial psychotic episode and may serve as indicator of vulnerability for developing schizophrenia.

Early somatosensory processing in individuals at risk for developing psychoses

PubMed Central

Hagenmuller, Florence; Heekeren, Karsten; Theodoridou, Anastasia; Walitza, Susanne; Haker, Helene; Rössler, Wulf; Kawohl, Wolfram

2014-01-01

Human cortical somatosensory evoked potentials (SEPs) allow an accurate investigation of thalamocortical and early cortical processing. SEPs reveal a burst of superimposed early (N20) high-frequency oscillations around 600 Hz. Previous studies reported alterations of SEPs in patients with schizophrenia. This study addresses the question whether those alterations are also observable in populations at risk for developing schizophrenia or bipolar disorders. To our knowledge to date, this is the first study investigating SEPs in a population at risk for developing psychoses. Median nerve SEPs were investigated using multichannel EEG in individuals at risk for developing bipolar disorders (n = 25), individuals with high-risk status (n = 59) and ultra-high-risk status for schizophrenia (n = 73) and a gender and age-matched control group (n = 45). Strengths and latencies of low- and high-frequency components as estimated by dipole source analysis were compared between groups. Low- and high-frequency source activity was reduced in both groups at risk for schizophrenia, in comparison to the group at risk for bipolar disorders. HFO amplitudes were also significant reduced in subjects with high-risk status for schizophrenia compared to healthy controls. These differences were accentuated among cannabis non-users. Reduced N20 source strengths were related to higher positive symptom load. These results suggest that the risk for schizophrenia, in contrast to bipolar disorders, may involve an impairment of early cerebral somatosensory processing. Neurophysiologic alterations in schizophrenia precede the onset of initial psychotic episode and may serve as indicator of vulnerability for developing schizophrenia. PMID:25309363

Using Strengths-Based Approaches in Early Years Practice and Research

ERIC Educational Resources Information Center

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

2015-01-01

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

Quadriceps rate of torque development and disability in individuals with anterior cruciate ligament reconstruction.

PubMed

Davis, Hope C; Troy Blackburn, J; Ryan, Eric D; Luc-Harkey, Brittney A; Harkey, Matthew S; Padua, Darin A; Pietrosimone, Brian

2017-07-01

The purpose of this study was to determine associations between self-reported function (International Knee Documentation Committee Index), isometric quadriceps strength and rate of torque development in individuals with a unilateral anterior cruciate ligament reconstruction. Forty-one individuals [31% male, BMI mean 25 (SD 4) kg/m 2 , months post anterior cruciate ligament reconstruction mean 49 (SD 40)] completed the self-reported function and isometric quadriceps function testing. Rate of torque development was assessed at 0-100ms (early), 100-200ms (late) ms, and peak following the onset of contraction. Associations were examined between rate of torque development, strength, and self-reported function. Linear regression was used to determine the unique amount of variance explained by the combination of rate of torque development and strength. Higher rate of torque development 100-200ms is weakly associated with higher self-reported function in individuals with a unilateral anterior cruciate ligament reconstruction (r=0.274, p=0.091); however, rate of torque development 100-200ms does not predict a significant amount of variance in self-reported function after accounting for strength (ΔR 2 =0.003, P=0.721). Quadriceps strength has a greater influence on self-reported function compared to rate of torque development in individuals with an anterior cruciate ligament reconstruction with time from surgery. Copyright © 2017 Elsevier Ltd. All rights reserved.

AMERICAN INDIAN AND ALASKA NATIVE BOYS: EARLY CHILDHOOD RISK AND RESILIENCE AMIDST CONTEXT AND CULTURE.

PubMed

Sarche, Michelle; Tafoya, Greg; Croy, Calvin D; Hill, Kyle

2017-01-01

American Indian and Alaska Native (AIAN) adolescent and adult men experience a range of health disparities relative to their non-AIAN counterparts and AIAN women. Given the relatively limited literature on early development in tribal contexts, however, indicators of risk during early childhood specific to AIAN boys are not well-known. The current article reviews sources of strength and challenge within AIAN communities for AIAN children in general, including cultural beliefs and practices that support development, and contextual challenges related to socioeconomic and health disparities and historical trauma affecting the AIAN population as a whole. The research literature on early development is reviewed, highlighting what this literature reveals about early gender differences. The article concludes with calls to action on behalf of AIAN boys that align with each of the five tiers of R. Frieden's (2010) Public Health Pyramid. © 2016 Michigan Association for Infant Mental Health.

The impact of early bilingualism on controlling a language learned late: an ERP study

PubMed Central

Martin, Clara D.; Strijkers, Kristof; Santesteban, Mikel; Escera, Carles; Hartsuiker, Robert J.; Costa, Albert

2013-01-01

This study asks whether early bilingual speakers who have already developed a language control mechanism to handle two languages control a dominant and a late acquired language in the same way as late bilingual speakers. We therefore, compared event-related potentials in a language switching task in two groups of participants switching between a dominant (L1) and a weak late acquired language (L3). Early bilingual late learners of an L3 showed a different ERP pattern (larger N2 mean amplitude) as late bilingual late learners of an L3. Even though the relative strength of languages was similar in both groups (a dominant and a weak late acquired language), they controlled their language output in a different manner. Moreover, the N2 was similar in two groups of early bilinguals tested in languages of different strength. We conclude that early bilingual learners of an L3 do not control languages in the same way as late bilingual L3 learners –who have not achieved native-like proficiency in their L2– do. This difference might explain some of the advantages early bilinguals have when learning new languages. PMID:24204355

Early prediction of intensive care unit-acquired weakness using easily available parameters: a prospective observational study.

PubMed

Wieske, Luuk; Witteveen, Esther; Verhamme, Camiel; Dettling-Ihnenfeldt, Daniela S; van der Schaaf, Marike; Schultz, Marcus J; van Schaik, Ivo N; Horn, Janneke

2014-01-01

An early diagnosis of Intensive Care Unit-acquired weakness (ICU-AW) using muscle strength assessment is not possible in most critically ill patients. We hypothesized that development of ICU-AW can be predicted reliably two days after ICU admission, using patient characteristics, early available clinical parameters, laboratory results and use of medication as parameters. Newly admitted ICU patients mechanically ventilated ≥2 days were included in this prospective observational cohort study. Manual muscle strength was measured according to the Medical Research Council (MRC) scale, when patients were awake and attentive. ICU-AW was defined as an average MRC score <4. A prediction model was developed by selecting predictors from an a-priori defined set of candidate predictors, based on known risk factors. Discriminative performance of the prediction model was evaluated, validated internally and compared to the APACHE IV and SOFA score. Of 212 included patients, 103 developed ICU-AW. Highest lactate levels, treatment with any aminoglycoside in the first two days after admission and age were selected as predictors. The area under the receiver operating characteristic curve of the prediction model was 0.71 after internal validation. The new prediction model improved discrimination compared to the APACHE IV and the SOFA score. The new early prediction model for ICU-AW using a set of 3 easily available parameters has fair discriminative performance. This model needs external validation.

Better concrete mixes for rapid repair in Wisconsin.

DOT National Transportation Integrated Search

2017-04-01

With the increasing demands on the highway system and increasing costs of user delay, the use and development of rapid-repairtechniques are expected to grow rapidly. High early strength (HES) portland cement concrete can help reduce the duration oftr...

Professional Development: Are We Meeting the Needs of State EHDI Programs?

ERIC Educational Resources Information Center

Houston, K. Todd; Munoz, Karen F.; Bradham, Tamala S.

2011-01-01

State coordinators of early hearing detection and intervention (EHDI) programs completed a strengths, weaknesses, opportunities, and threats, or SWOT, analysis that consisted of 12 evaluative areas of EHDI programs. For the professional development area, 47 coordinators responded with a total of 223 items, and themes were identified in each SWOT…

Baby Sign but Not Spontaneous Gesture Predicts Later Vocabulary in Children with Down Syndrome

ERIC Educational Resources Information Center

Özçaliskan, Seyda; Adamson, Lauren B.; Dimitrova, Nevena; Bailey, Jhonelle; Schmuck, Lauren

2016-01-01

Early spontaneous gesture, specifically deictic gesture, predicts subsequent vocabulary development in typically developing (TD) children. Here, we ask whether deictic gesture plays a similar role in predicting later vocabulary size in children with Down Syndrome (DS), who have been shown to have difficulties in speech production, but strengths in…

The tensile strength of ice and dust aggregates and its dependence on particle properties

NASA Astrophysics Data System (ADS)

Gundlach, B.; Schmidt, K. P.; Kreuzig, C.; Bischoff, D.; Rezaei, F.; Kothe, S.; Blum, J.; Grzesik, B.; Stoll, E.

2018-06-01

The knowledge of the tensile strength of astrophysical dust and ice aggregates is of major importance to understand the early stages of planet formation in our solar system and cometary activity. In this letter we report on an experimental setup, developed to measure the tensile strength of granular, astrophysical relevant materials, such as water ice and silica aggregates. We found that the tensile strength of aggregates composed of monodisperse silica particles depends on the grain size of the used material and is in a good agreement with the predictions of earlier works. For aggregates consisting of polydisperse water-ice particles, the measured tensile strength is very low compared to the theoretical prediction, which indicates that the specific surface energy of water ice at low temperatures is lower than previously assumed.

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.

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

ERIC Educational Resources Information Center

Abernethy, Catherine

2010-01-01

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

Developing a Kindergartener's Concept of Cardinality

ERIC Educational Resources Information Center

Throndsen, Jennifer; MacDonald, Beth; Hunt, Jessica

2017-01-01

Building students' understanding of cardinality is fundamental for working with numbers and operations. Without these early mathematical foundations in place, students will fall behind. Consequently, it is imperative to build on students' strengths to address their weaknesses with the notion of cardinality.

Timing of Decompression in Patients With Acute Spinal Cord Injury: A Systematic Review

PubMed Central

Wilson, Jefferson R.; Tetreault, Lindsay A.; Kwon, Brian K.; Arnold, Paul M.; Mroz, Thomas E.; Shaffrey, Christopher; Harrop, James S.; Chapman, Jens R.; Casha, Steve; Skelly, Andrea C.; Holmer, Haley K.; Brodt, Erika D.; Fehlings, Michael G.

2017-01-01

Study Design: Systematic review. Objective: To conduct a systematic review and synthesis of the literature to assess the comparative effectiveness, safety, and cost-effectiveness of early (≤24 hours) versus late decompression (>24 hours) in adults with acute spinal cord injury (SCI). Methods: A systematic search was conducted of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar to identify studies published through November 6, 2014. Studies published in any language, in humans, and with an abstract were considered for inclusion. Included studies were critically appraised and the overall strength of evidence was determined using methods proposed by the Grading of Recommendation Assessment, Development and Evaluation working group. Results: The search yielded 449 potentially relevant citations. Sixteen additional primary studies were identified through other sources. Six studies met inclusion criteria. All but 2 studies were considered to have moderately high risk of bias. Across studies and injury levels, the impact of early surgical decompression (≤24 hours) on clinically important improvement in neurological status was variable. Isolated studies reported statistically significant and clinically important improvements at 6 months (cervical injury, low strength of evidence) and following discharge from inpatient rehabilitation (all levels, very low strength of evidence) but not at other time points; another study observed a statistically significant 6 point improvement in ASIA Impairment Scale (AIS) among patients with AIS B, C, or D, but not for those with AIS A (very low strength of evidence). In one study of acute central cord syndrome without instability, a clinically and statistically meaningful improvement in total motor scores was reported at 6 and 12 months in patients treated early (versus late). There were, however, no significant differences in AIS improvement between early and late surgical groups at 6- or 12-months (very low strength of evidence). One of 3 studies found a shorter length of hospital stay associated with early surgical decompression. Of 3 studies reporting on safety, no significant differences in rates of complications (including mortality, neurologic deterioration, pneumonia or pressure ulcers) were noted between early and late decompression groups. Conclusions: Results surrounding the efficacy of early versus late decompressive surgery, as well as the quality of evidence available, were variable depending on the level of SCI, timing of follow-up, and specific outcome considered. Existing evidence supports improved neurological recovery among cervical SCI patients undergoing early surgery; however, evidence regarding remaining SCI populations and clinical outcomes was inconsistent. PMID:29164038

Professional development themes in strength and conditioning coaches.

PubMed

Tod, David A; Bond, Kath A; Lavallee, David

2012-03-01

The purpose of this study was to explore professional development themes in experienced strength and conditioning coaches. Strength and conditioning coaches (N = 15, mean age = 34.3 years, SD = 5.2 years) with 11.4 (SD = 4.9) years experience working with elite, professional, or talented athletes were interviewed about their professional development. The interviews were transcribed verbatim and content analyzed. Over time, subjects' service-delivery practices became more flexible and client driven. Their role understanding also broadened to include various dimensions, such as the need to consider various stakeholders and the value of good relationships with athletes. The subjects shifted from relying on external justification for professional decision making to their experience-based knowledge. The subjects believed athlete work experience, interactions with senior strength and conditioning coaches and other colleagues, the professional literature, and nonprofessional experiences, such as their own athletic experience and sales or managerial training, were the primary influences on their professional development. Typically, the subjects experienced anxiety about their competence, both early in their careers and when working in new contexts or with new athlete groups, but over time, they developed increased confidence. In addition, the subjects experienced reduced narcissism over time about the control they had over athletes and their competitive results. The current results provide information about the characteristics of effective strength and conditioning coaches, the ways they develop their competencies to help athletes, and the emotions they experience throughout their careers. These results may help strength and conditioning practitioners in planning and optimizing their professional development and effectiveness with athletes.

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

Maturity- and sex-related changes in tibial bone geometry, strength and bone-muscle strength indices during growth: a 20-month pQCT study.

PubMed

Macdonald, Heather M; Kontulainen, Saija A; Mackelvie-O'Brien, Kerry J; Petit, Moira A; Janssen, Patricia; Khan, Karim M; McKay, Heather A

2005-06-01

During growth, bone strength is conferred through subtle adaptations in bone mass and geometry in response to muscle forces. Few studies have examined the changes in bone geometry, strength and the bone-muscle strength relationship across maturity in boys and girls. Our aims were to describe (i) 20-month changes in bone geometry and strength at the tibial midshaft across three maturity groups of boys and girls, (ii) differences in these adaptations between sexes at the same approximate level of maturity and (iii) the bone-muscle strength relationship across maturity groups of boys and girls and between sexes. We used peripheral quantitative computed tomography (pQCT, Stratec XCT-2000) to measure change in total bone cross-sectional area (ToA, mm(2)), cortical area (CoA, mm(2)), average cortical thickness (C.Th., mm), section modulus (mm(3)) and muscle cross-sectional area (mm(2)) at the tibial midshaft (50% site) in 128 EARLY-, PERI- and POST-pubertal girls (n = 69, 11.9 +/- 0.6 years) and boys (n = 59, 12.0 +/- 0.6 years) across 20 months. We also calculated two bone-muscle strength indices (BMSI) for compression (CoA/MCSA) and bending [strength index/MCSA; where strength index = Z / (tibial length / 2)]. EARLY boys and girls had smaller ToA at baseline than same sex PERI or POST participants. There were no sex differences in ToA or CoA at baseline; however, boys increased both parameters significantly more than girls in every maturity group (8.5-11.1%, P < 0.01). These changes in bone geometry conferred greater gains in bone strength for boys compared with girls in each maturity group (13.8-15.6%, P < 0.01). Baseline BMSIs did not differ between sexes for EARLY and PERI groups, whereas BMSIs were significantly higher for POST boys compared with POST girls (P < 0.05). BMSIs decreased for EARLY and PERI girls (-7.4-(-1.1%)) whereas the ratios remained stable for EARLY and PERI boys (-0.6-2.5%). This sex difference in BMSI change was due to a relatively greater increase in CoA among EARLY and PERI boys compared with same-maturity girls. BMSIs remained stable in POST girls and decreased in POST boys due to relatively greater gains in MCSA. This study provides novel longitudinal descriptions of the maturity- and sex-specific changes in bone geometry, strength and bone-muscle strength indices.

MSW fly ash stabilized with coal ash for geotechnical application.

PubMed

Kamon, M; Katsumi, T; Sano, Y

2000-09-15

The solidification and stabilization of municipal solid waste (MSW) fly ash for the purpose of minimizing the geo-environmental impact caused by toxic heavy metals as well as ensuring engineering safety (strength and soaking durability) are experimentally evaluated. The mixtures of MSW fly ash stabilized with cement and fluidized bed combustion coal fly ash (FCA) were used for unconfined compressive strength tests, leachate tests, and soaking tests. The behavior of soluble salts contained in the MSW fly ash significantly affects strength development, soaking durability, and the hardening reaction of the stabilized MSW fly ash mixtures. The cement stabilization of the MSW fly ash does not have enough effect on strength development and soaking durability. The addition of cement only contributes to the containment of heavy metals due to the high level of alkalinity. When using FCA as a stabilizing agent for MSW fly ash, the mixture exhibits high strength and durability. However, the Cd leachate cannot be prevented in the early stages of curing. Using a combination of cement and FCA as a MSW fly ash stabilizer can attain high strength, high soaking durability, and the containment of heavy metals. The stabilized MSW fly ash with cement and FCA can be practically applied to embankments.

Very-Early-Strength Latex-Modified Concrete Overlays

DOT National Transportation Integrated Search

1998-12-01

This report describes the installation and condition of the first two very-early-strength latex-modified concrete (LMC-VE) overlays to be constructed for the Virginia Department of Transportation. The overlays were prepared with a special blended cem...

Very-early-strength latex-modified concrete overlay.

DOT National Transportation Integrated Search

1998-12-01

This paper describes the installation and condition of the first two very-early-strength latex modified concrete (LMC-VE) overlays constructed for the Virginia Department of Transportation. The overlays were prepared with a special blended cement rat...

Disrupted neural synchronization in toddlers with autism

PubMed Central

Dinstein, Ilan; Pierce, Karen; Eyler, Lisa; Solso, Stephanie; Malach, Rafael; Behrmann, Marlene; Courchesne, Eric

2011-01-01

Summary Autism is often described as a disorder of neural synchronization. However, it is unknown how early in development synchronization abnormalities emerge and whether they are related to the development of early autistic behavioral symptoms. Here, we show that disrupted synchronization is evident in the spontaneous cortical activity of naturally sleeping toddlers with autism, but not in toddlers with language delay or typical development. Toddlers with autism exhibited significantly weaker inter-hemispheric synchronization (i.e. weak “functional connectivity” across the two hemispheres) in putative language areas. The strength of synchronization was positively correlated with verbal ability, negatively correlated with autism severity, and enabled identification of the majority of autistic toddlers (72%) with high accuracy (84%). Disrupted cortical synchronization, therefore, appears to be a notable characteristic of autism neurophysiology that is evident at very early stages of autism development. PMID:21689606

Using a centrifuge for quality control of pre-wetted lightweight aggregate in internally cured concrete

NASA Astrophysics Data System (ADS)

Miller, Albert E.

Early age shrinkage of cementitious systems can result in an increased potential for cracking which can lead to a reduction in service life. Early age shrinkage cracking can be particularly problematic for high strength concretes, which are often specified due to their high strength and low permeability. However, these high strength concretes frequently exhibit a reduction in the internal relative humidity (RH) due to the hydration reaction (chemical shrinkage) and self-desiccation which results in a bulk shrinkage, termed autogenous shrinkage, which is substantial at early ages. Due to the low permeability of these concretes, standard external curing is not always efficient in addressing this reduction in internal RH since the penetration of water can be limited. Internal curing has been developed to reduce autogenous shrinkage. Internally cured mixtures use internal reservoirs filled with fluid (generally water) that release this fluid at appropriate times to counteract the effects of self-desiccation thereby maintaining a high internal RH. Internally cured concrete is frequently produced in North America using pre-wetted lightweight aggregate. One important aspect associated with preparing quality internally cured concrete is being able to determine the absorbed moisture and surface moisture associated with the lightweight aggregate which enables aggregate moisture corrections to be made for the concrete mixture. This thesis represents work performed to develop a test method using a centrifuge to determine the moisture state of pre-wetted fine lightweight aggregate. The results of the test method are then used in a series of worksheets that were developed to assist field technicians when performing the tests and applying the results to a mixture design. Additionally, research was performed on superabsorbent polymers to assess their ability to be used as an internal curing reservoir.

High early strength latex modified concrete overlay.

DOT National Transportation Integrated Search

1988-01-01

This report describes the condition of the first high early strength latex modified concrete (LMC-HE) overlay to be constructed for the Virginia Department of Transportation. The overlay was prepared with type III cement and with more cement and less...

Growth hormone therapy, muscle thickness, and motor development in Prader-Willi syndrome: an RCT.

PubMed

Reus, Linda; Pillen, Sigrid; Pelzer, Ben J; van Alfen-van der Velden, Janielle A A E M; Hokken-Koelega, Anita C S; Zwarts, Machiel; Otten, Barto J; Nijhuis-van der Sanden, Maria W G

2014-12-01

To investigate the effect of physical training combined with growth hormone (GH) on muscle thickness and its relationship with muscle strength and motor development in infants with Prader-Willi syndrome (PWS). In a randomized controlled trial, 22 infants with PWS (12.9 ± 7.1 months) were followed over 2 years to compare a treatment group (n = 10) with a waiting-list control group (n = 12). Muscle thickness of 4 muscle groups was measured by using ultrasound. Muscle strength was evaluated by using the Infant Muscle Strength meter. Motor performance was measured with the Gross Motor Function Measurement. Analyses of variance were used to evaluate between-group effects of GH on muscle thickness at 6 months and to compare pre- and posttreatment (after 12 months of GH) values. Multilevel analyses were used to evaluate effects of GH on muscle thickness over time, and multilevel bivariate analyses were used to test relationships between muscle thickness, muscle strength, and motor performance. A significant positive effect of GH on muscle thickness (P < .05) was found. Positive relationships were found between muscle thickness and muscle strength (r = 0.61, P < .001), muscle thickness and motor performance (r = 0.81, P < .001), and muscle strength and motor performance (r = 0.76, P < .001). GH increased muscle thickness, which was related to muscle strength and motor development in infants with PWS. Catch-up growth was faster in muscles that are most frequently used in early development. Because this effect was independent of GH, it suggests a training effect. Copyright © 2014 by the American Academy of Pediatrics.

Investigation of properties of high-performance fiber-reinforced concrete : very early strength, toughness, permeability, and fiber distribution : final report.

DOT National Transportation Integrated Search

2017-01-01

Concrete cracking, high permeability, and leaking joints allow for intrusion of harmful solutions, resulting in concrete deterioration and corrosion of reinforcement in structures. The development of durable, high-performance concretes with limited c...

Use of colliery spoil for infilling mine workings

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

Ghataora, G.S.; Jarvis, S.T.

1996-12-31

Colliery spoil has been used as a major constituent of rock paste, a controlled low-strength bulk infill material, to infill abandoned limestone mines in the West Midlands of England since the early 1980s. During this time the design of colliery spoil rock paste has been modified and improved to ensure that strengths are achieved and consolidation is minimized. This paper describes the methods used for measuring and monitoring the development of the strength of rock paste used to infill the Littleton Street Mine in Walsall, England. The mine had a volume of about 500,000 m{sup 3} and is possibly themore » largest underground void to be infilled with rock paste.« less

A comparison of strength-training, self-management and the combination for early osteoarthritis of the knee

PubMed Central

McKnight, Patrick E.; Kasle, Shelley; Going, Scott; Villaneuva, Isidro; Cornett, Michelle; Farr, Josh; Wright, Jill; Streeter, Clara; Zautra, Alex

2010-01-01

Objective To assess the relative effectiveness of combining self-management and strength-training for improving functional outcomes in early knee osteoarthritis patients. Methods A randomized intervention trial lasting 24 months conducted at an academic medical center. Community dwelling middle-aged adults (N=273), aged 34 to 65 with knee osteoarthritis, pain and self-reported physical disability completed a strength-training program, a self-management program, or a combined program. Outcomes included five physical function tests (leg press, range of motion, work capacity, balance, and stair climbing) and two self-reported measures of pain and disability. Results A total of 201 (73.6 %) participants completed the 2-year trial. Overall compliance was modest - strength-training (55.8 %), self-management (69.1 %), and combined (59.6 %) programs. The three groups showed a significant and large increase from pre- to post-treatment in all physical functioning measures including leg press (d =.85), range of motion (d=1.00), work capacity (d=.60), balance (d=.59), and stair climbing (d=.59). Additionally, all three groups showed decreased self-reported pain (d=-.51) and disability (d=-.55). There were no significant differences among groups. Conclusions Middle-aged, sedentary persons with mild early knee osteoarthritis benefited from strength-training, self-management, and the combination. These results suggest that both strength-training and self-management are suitable treatments for early onset of knee osteoarthritis in middle-aged adults. Self-management alone may offer the least burdensome treatment for early osteoarthritis. PMID:20191490

Strengths, weaknesses, opportunities, and threats analysis of integrating the World Health Organization patient safety curriculum into undergraduate medical education in Pakistan: a qualitative case study.

PubMed

Misbah, Samreen; Mahboob, Usman

2017-01-01

The purpose of this study was to conduct a strengths, weaknesses, opportunities, and threats (SWOT) analysis of integrating the World Health Organization (WHO) patient safety curriculum into undergraduate medical education in Pakistan. A qualitative interpretive case study was conducted at Riphah International University, Islamabad, from October 2016 to June 2017. The study included 9 faculty members and 1 expert on patient safety. The interviews were audiotaped, and a thematic analysis of the transcripts was performed using NVivo software. Four themes were derived based on the need analysis model. The sub-themes derived from the collected data were arranged under the themes of strengths, weaknesses, opportunities, and threats, in accordance with the principles of SWOT analysis. The strengths identified were the need for a formal patient safety curriculum and its early integration into the undergraduate program. The weaknesses were faculty awareness and participation in development programs. The opportunities were an ongoing effort to develop an appropriate curriculum, to improve the current culture of healthcare, and to use the WHO curricular resource guide. The threats were attitudes towards patient safety in Pakistani culture, resistance to implementation from different levels, and the role of regulatory authorities. The theme of patient safety needs to be incorporated early into the formal medical education curriculum, with the main goals of striving to do no harm and seeing mistakes as opportunities to learn. Faculty development activities need to be organized, and faculty members should to be encouraged to participate in them. The lack of a patient safety culture was identified as the primary reason for resistance to this initiative at many levels. The WHO curriculum, amended according to local institutional culture, can be implemented appropriately with support from the corresponding regulatory bodies.

Reframing the risks and losses of teen mothering.

PubMed

SmithBattle, Lee

2009-01-01

Teen mothers often face a stigmatizing gaze based on the belief that early childbearing jeopardizes their life chances and the health and development of their children. Growing evidence suggests that the poor maternal-child outcomes associated with early childbearing have been overstated and may be explained by teen mothers' childhood disadvantage and adversities. After reviewing what is currently known about the relationships between early childbearing and maternal-child outcomes, as well as teen mothers' perspectives on mothering, clinical practices are suggested that address teen mothers' concerns, strengths, aspirations, and the long-term inequities that contribute to poor outcomes.

Complex strength performance in patients with haemophilia A. Method development and testing.

PubMed

Runkel, B; Kappelhoff, M; Hilberg, T

2015-01-01

The aim of this study was to develop a complex strength measurement method and to apply this new method for the first time in patients with haemophilia (PwH). 20 PwH with severe haemophilia A and 20 controls were included into the study. All subjects completed ten measurements of maximum isometric strength. Furthermore, the 20 control subjects completed re-test-measurements to evaluate the method. As a result, the method showed a high reliability (ICC 0.764 to 0.934). Between the two groups significant reductions in PwH between -(19-35%) were detected, regarding the relative force of the M. triceps brachii (-19%; p = 0.008), M. biceps brachii (-19%; p = 0.031), M. latissimus dorsi (-17%; p = 0.019), M. biceps femoris right (-20%; p = 0.036) and M. quadriceps femoris (right: -29%; p = 0.004; left: -35%; p = 0.002). No differences were found for M. rectus abdominis and in the hand strength. Thus, there is no general deficit in the muscle strength in PwH. The most obvious deficits exist in the upper and lower extremities and in the back muscles. PwH should carry out complex muscle strength training and integrate it early into a comprehensive treatment concept.

Precipitation and Hardening in Magnesium Alloys

NASA Astrophysics Data System (ADS)

Nie, Jian-Feng

2012-11-01

Magnesium alloys have received an increasing interest in the past 12 years for potential applications in the automotive, aircraft, aerospace, and electronic industries. Many of these alloys are strong because of solid-state precipitates that are produced by an age-hardening process. Although some strength improvements of existing magnesium alloys have been made and some novel alloys with improved strength have been developed, the strength level that has been achieved so far is still substantially lower than that obtained in counterpart aluminum alloys. Further improvements in the alloy strength require a better understanding of the structure, morphology, orientation of precipitates, effects of precipitate morphology, and orientation on the strengthening and microstructural factors that are important in controlling the nucleation and growth of these precipitates. In this review, precipitation in most precipitation-hardenable magnesium alloys is reviewed, and its relationship with strengthening is examined. It is demonstrated that the precipitation phenomena in these alloys, especially in the very early stage of the precipitation process, are still far from being well understood, and many fundamental issues remain unsolved even after some extensive and concerted efforts made in the past 12 years. The challenges associated with precipitation hardening and age hardening are identified and discussed, and guidelines are outlined for the rational design and development of higher strength, and ultimately ultrahigh strength, magnesium alloys via precipitation hardening.

Graduation Coaching in a Rural District School

ERIC Educational Resources Information Center

Zeller, Pamela J.; Carpenter, Shelly; Lacefield, Warren E.; Applegate, E. Brooks

2013-01-01

The GEAR UP graduation coach intervention developed by the GEAR UP Learning Centers at Western Michigan University (WMU) addresses the issue of academic failure of at-risk students in high school. This personalized early intervention strategy begins by assessing students' unique circumstances, academic histories, and strengths and weaknesses in…

Key Considerations in Assessing Young Children's Emotional Competence

ERIC Educational Resources Information Center

Denham, Susanne A.; Ferrier, David E.; Howarth, Grace Z.; Herndon, Kristina J.; Bassett, Hideko H.

2016-01-01

Recent years have witnessed a surge in evidence on preschoolers' emotional development as crucial for both concurrent and later well-being and mental health, and for learning and academic success. Given the importance of building such strengths, assessing emotional competence skills is important to aid early childhood educators in focusing…

Highway concrete pavement technology development and testing : volume III, field evaluation of Strategic Highway Research Program (SHRP) C-205 test sites (high-performance concrete).

DOT National Transportation Integrated Search

2006-05-01

This research study, sponsored by the Federal Highway Administration, summarizes the field performance of eight high-early-strength (HES) : concrete patches between 1994 and 1998. The patches were constructed under the Strategic Highway Research Prog...

Behavioral and Emotional Rating Scale: Two Studies of Convergent Validity

ERIC Educational Resources Information Center

Trout, Alexandra L.; Ryan, Joseph B.; La Vigne, Steven P.; Epstein, Michael H.

2003-01-01

As the field of mental health services shifts its focus to early intervention, the need to develop valid and reliable measures of young children's behavioral functioning is clear. Traditional assessment instruments have focused on deficits, problems, and pathologies to the exclusion of strengths and competencies. However, assessing child strengths…

The role of meta-analysis in the evaluation of the effects of early nutrition on mental and motor development in children.

PubMed

Szajewska, Hania

2011-12-01

The role of early nutrition as a cost-effective measure to ensure optimal infant growth, development, and long-term health is gaining attention. In particular, the role of supplementation with nutrients such as n-3 (omega-3) fatty acids, iron, zinc, and B vitamins, which are relevant to brain structure and function, is of interest. However, for all of these nutrients, there is a lack of clarity and no consensus regarding their role in the mental and motor development of children. Systematic reviews with or without a meta-analysis are a well-established means of reviewing existing evidence and of integrating findings from various studies, including those related to infant nutrition. In this article, I provide an overview of the basic principles of systematic review and meta-analysis of randomized controlled trials (RCTs) and summarize such evidence related to the effects of early nutrition on mental and motor development. The inclusion of only RCTs in a systematic review could be considered the major strength. Randomization is the only means to control for unknown and unmeasured differences between comparison groups as well as for those that are known and measured. However, even if only RCTs are included, reviews are not free of potential biases. An understanding of the strengths and limitations of the meta-analytic approach, which I discuss in this article, is needed by everyone involved in decision making regarding interventions assessed by this approach.

Increased Tensile Strength of Carbon Nanotube Yarns and Sheets through Chemical Modification and Electron Beam Irradiation

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Williams, Tiffany S.; Baker, James S.; Sola, Francisco; Lebron-Colon, Marisabel; McCorkle, Linda S.; Wilmoth, Nathan G.; Gaier, James; Chen, Michelle; Meador, Michael A.

2014-01-01

The inherent strength of individual carbon nanotubes offers considerable opportunity for the development of advanced, lightweight composite structures. Recent work in the fabrication and application of carbon nanotube (CNT) forms such as yarns and sheets has addressed early nanocomposite limitations with respect to nanotube dispersion and loading; and has pushed the technology toward structural composite applications. However, the high tensile strength of an individual CNT has not directly translated to macro-scale CNT forms where bulk material strength is limited by inter-tube electrostatic attraction and slippage. The focus of this work was to assess post processing of CNT sheet and yarn to improve the macro-scale strength of these material forms. Both small molecule functionalization and e-beam irradiation was evaluated as a means to enhance tensile strength and Youngs modulus of the bulk CNT material. Mechanical testing results revealed a tensile strength increase in CNT sheets by 57 when functionalized, while an additional 48 increase in tensile strength was observed when functionalized sheets were irradiated; compared to unfunctionalized sheets. Similarly, small molecule functionalization increased yarn tensile strength up to 25, whereas irradiation of the functionalized yarns pushed the tensile strength to 88 beyond that of the baseline yarn.

Assessment of high early strength limestone blended cement for next generation transportation structures : final report.

DOT National Transportation Integrated Search

2016-12-01

This research on Type IL cements for high early strength concretes demonstrated that Type IL cements satisfying AASHTO M 240 specifications may be used in place of Type I/II cements which satisfy AASHTO M 85 specifications for construction of transpo...

Unknown loads affect force production capacity in early phases of bench press throws.

PubMed

Hernández Davó, J L; Sabido Solana, R; Sarabia Marínm, J M; Sánchez Martos, Á; Moya Ramón, M

2015-10-01

Explosive strength training aims to improve force generation in early phases of movement due to its importance in sport performance. The present study examined the influence of lack of knowledge about the load lifted in explosive parameters during bench press throws. Thirteen healthy young men (22.8±2.0 years) participated in the study. Participants performed bench press throws with three different loads (30, 50 and 70% of 1 repetition maximum) in two different conditions (known and unknown loads). In unknown condition, loads were changed within sets in each repetition and participants did not know the load, whereas in known condition the load did not change within sets and participants had knowledge about the load lifted. Results of repeated-measures ANOVA revealed that unknown conditions involves higher power in the first 30, 50, 100 and 150 ms with the three loads, higher values of ratio of force development in those first instants, and differences in time to reach maximal rate of force development with 50 and 70% of 1 repetition maximum. This study showed that unknown conditions elicit higher values of explosive parameters in early phases of bench press throws, thereby this kind of methodology could be considered in explosive strength training.

Fatigue response of notched laminates subjected to tension-compression cyclic loads

NASA Technical Reports Server (NTRS)

Bakis, C. E.; Stinchcomb, W. W.

1986-01-01

The fatigue response of a ((0/45/90/-45)(sub s))(sub 4) T300-5208 graphite-epoxy laminate with a drilled center-hole subjected to various components of tensile and compressive cyclic loads was investigated. Damage evaluation techniques such as stiffness monitoring, penetrant-enhanced X-ray radiography, C-scan, laminate deply and residual strength measurement were used to establish the mechanisms of damage development as well as the effect of such damage on the laminate strength, stiffness and life. Damage modes consisted of transverse matrix cracks, initiating at the hole, in all plies, followed by delamination between plies of different orientation. A characteristic stiffness repsonse during cyclic loading at two load levels was identified and utilized a more reliable indicator of material and residual properties than accumulated cycles. For the load ratios of tension-compression loading, residual tensile strength increased significantly above the virgin strength early in the fatigue life and remained approximately constant to near the end of life. A technique developed for predicting delamination initiation sites along the hole boundary correlated well with experimental evidence.

Development of high-speed balancing technology

NASA Technical Reports Server (NTRS)

Demuth, R.; Zorzi, E.

1981-01-01

An investigation into laser material removal showed that laser burns act in a manner typical of mechanical stress raisers causing a reduction in fatigue strength; the fatigue strength is lowered relative to the smooth specimen fatigue strength. Laser-burn zones were studied for four materials: Alloy Steel 4340, Stainless Steel 17-4 PH, Inconel 718, and Aluminum Alloy 6061-T6. Calculations were made of stress concentration factors K, for laser-burn grooves of each material type. A comparison was then made to experimentally determine the fatigue strength reduction factor. These calculations and comparisons indicated that, except for the 17-4 PH material, good agreement (a ratio of close to 1.0) existed between Kt and Kf. The performance of the 17-4 PH material has been attributed to early crack initiation due to the lower fatigue resistance of the soft, unaged laser-affected zone. Also covered in this report is the development, implementation, and testing of an influence coefficient approach to balancing a long, slender shaft under applied-torque conditions. Excellent correlation existed between the analytically predicted results and those data obtained from testing.

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

PubMed

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

2013-10-01

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

Using cross-species comparisons and a neurobiological framework to understand early social deprivation effects on behavioral development.

PubMed

Brett, Zoë H; Humphreys, Kathryn L; Fleming, Alison S; Kraemer, Gary W; Drury, Stacy S

2015-05-01

Building upon the transactional model of brain development, we explore the impact of early maternal deprivation on neural development and plasticity in three neural systems: hyperactivity/impulsivity, executive function, and hypothalamic-pituitary-adrenal axis functioning across rodent, nonhuman primate, and human studies. Recognizing the complexity of early maternal-infant interactions, we limit our cross-species comparisons to data from rodent models of artificial rearing, nonhuman primate studies of peer rearing, and the relations between these two experimental approaches and human studies of children exposed to the early severe psychosocial deprivation associated with institutional care. In addition to discussing the strengths and limitations of these paradigms, we present the current state of research on the neurobiological impact of early maternal deprivation and the evidence of sensitive periods, noting methodological challenges. Integrating data across preclinical animal models and human studies, we speculate about the underlying biological mechanisms; the differential impact of deprivation due to temporal factors including onset, offset, and duration of the exposure; and the possibility and consequences of reopening of sensitive periods during adolescence.

Using cross-species comparisons and a neurobiological framework to understand early social deprivation effects on behavioral development

PubMed Central

BRETT, ZOË H.; HUMPHREYS, KATHRYN L.; FLEMING, ALISON S.; KRAEMER, GARY W.; DRURY, STACY S.

2017-01-01

Building upon the transactional model of brain development, we explore the impact of early maternal deprivation on neural development and plasticity in three neural systems: hyperactivity/impulsivity, executive function, and hypothalamic–pituitary–adrenal axis functioning across rodent, nonhuman primate, and human studies. Recognizing the complexity of early maternal–infant interactions, we limit our cross-species comparisons to data from rodent models of artificial rearing, nonhuman primate studies of peer rearing, and the relations between these two experimental approaches and human studies of children exposed to the early severe psychosocial deprivation associated with institutional care. In addition to discussing the strengths and limitations of these paradigms, we present the current state of research on the neurobiological impact of early maternal deprivation and the evidence of sensitive periods, noting methodological challenges. Integrating data across preclinical animal models and human studies, we speculate about the underlying biological mechanisms; the differential impact of deprivation due to temporal factors including onset, offset, and duration of the exposure; and the possibility and consequences of reopening of sensitive periods during adolescence. PMID:25997759

Ebb and Flow in Parent-Child Interactions: Shifts from Early through Middle Childhood

PubMed Central

Bradley, Robert H.; Pennar, Amy; Iida, Masumi

2015-01-01

Objective This study documents the strength of relations between key parent and child behaviors as they occur during typical encounters for both mothers and fathers and determines whether there were shifts in the strength of relations between parent and child behaviors during early and middle childhood. Design Multivariate multi-level modeling was used to examine associations between three parent behaviors (respect for autonomy, stimulation of development, hostility) and two child behaviors (agency, negativity) as they occurred in typical parent-child activities at four time points from 54 months through 5th grade for 817 families. Results For mothers and fathers, respect for autonomy and stimulation were associated with child agency. Paternal hostility was negatively associated with child agency, but for mothers the relation became more positive with age. Parental respect for autonomy and hostility were associated with child negativity for both mothers and fathers; however, for mothers, relations between autonomy support and child negativity became more positive, and relations between hostility and child negativity became less positive. Conclusions There are clear shifts in the strength of relations between some parenting behaviors and child behaviors from early to middle childhood, indicative of a changing dialectic as children become more independent and different dialectics for mothers and fathers. Parenting behavior links to child competence and adaptive behavior, and the findings may help resolve some uncertainties about relations between parental behavior and children's developmental trajectories. PMID:26877717

Massage therapy during early postnatal life promotes greater lean mass and bone growth, mineralization, and strength in juvenile and young adult rats.

PubMed

Chen, H; Miller, S; Shaw, J; Moyer-Mileur, L

2009-01-01

The objects of this study were to investigate the effects of massage therapy during early life on postnatal growth, body composition, and skeletal development in juvenile and young adult rats. Massage therapy was performed for 10 minutes daily from D6 to D10 of postnatal life in rat pups (MT, n=24). Body composition, bone area, mineral content, and bone mineral density were measured by dual energy X-ray absorptiometry (DXA); bone strength and intrinsic stiffness on femur shaft were tested by three-point bending; cortical and cancellous bone histomorphometric measurements were performed at D21 and D60. Results were compared to age- and gender-matched controls (C, n=24). D21 body weight, body length, lean mass, and bone area were significantly greater in the MT cohort. Greater bone mineral content was found in male MT rats; bone strength and intrinsic stiffness were greater in D60 MT groups. At D60 MT treatment promoted bone mineralization by increasing trabecular mineral apposition rate in male and endosteal mineral surface in females, and also improved micro-architecture by greater trabeculae width in males and decreasing trabecular separation in females. In summary, massage therapy during early life elicited immediate and prolonged anabolic effects on postnatal growth, lean mass and skeletal developmental in a gender-specific manner in juvenile and young adult rats.

A review in high early strength concrete and local materials potential

NASA Astrophysics Data System (ADS)

Yasin, A. K.; Bayuaji, R.; Susanto, T. E.

2017-11-01

High early strength concrete is one of the type in high performance concrete. A high early strength concrete means that the compressive strength of the concrete at the first 24 hours after site-pouring could achieve structural concrete quality (compressive strength > 21 MPa). There are 4 (four) important factors that must be considered in the making process, those factors including: portland cement type, cement content, water to cement ratio, and admixture. In accordance with its high performance, the production cost is estimated to be 25 to 30% higher than conventional concrete. One effort to cut the production cost is to utilize local materials. This paper will also explain about the local materials which were abundantly available, cheap, and located in strategic coast area of East Java Province, that is: Gresik, Tuban and Bojonegoro city. In addition, the application of this study is not limited only to a large building project, but also for a small scale building which has one to three-story. The performance of this concrete was apparently able to achieve the quality of compressive strength of 27 MPa at the age of 24 hours, which qualified enough to support building structurally.

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

ERIC Educational Resources Information Center

Lickey, Deborah C.; Powers, Denise J.

2011-01-01

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

Profiles of children's social-emotional health at school entry and associated income, gender and language inequalities: a cross-sectional population-based study in British Columbia, Canada.

PubMed

Thomson, Kimberly C; Guhn, Martin; Richardson, Chris G; Ark, Tavinder K; Shoveller, Jean

2017-07-26

Early identification of distinct patterns of child social-emotional strengths and vulnerabilities has the potential to improve our understanding of child mental health and well-being; however, few studies have explored natural groupings of indicators of child vulnerability and strengths at a population level. The purpose of this study was to examine heterogeneity in the patterns of young children's social and emotional health and investigate the extent to which sociodemographic characteristics were associated. Cross-sectional study based on a population-level cohort. All kindergarten children attending public schools between 2004 and 2007 in British Columbia (BC), Canada. 35 818 kindergarten children (age of 5 years) with available linked data from the Early Development Instrument (EDI), BC Ministry of Health and BC Ministry of Education. We used latent profile analysis (LPA) to identify distinct profiles of social-emotional health according to children's mean scores across eight social-emotional subscales on the EDI, a teacher-rated measure of children's early development. Subscales measured children's overall social competence, responsibility and respect, approaches to learning, readiness to explore, prosocial behaviour, anxiety, aggression and hyperactivity. Six social-emotional profiles were identified: (1) overall high social-emotional functioning, (2) inhibited-adaptive (3) uninhibited-adaptive, (4) inhibited-disengaged, (5) uninhibited-aggressive/hyperactive and (6) overall low social-emotional functioning. Boys, children with English as a second language (ESL) status and children with lower household income had higher odds of membership to the lower social-emotional functioning groups; however, this association was less negative among boys with ESL status. Over 40% of children exhibited some vulnerability in early social-emotional health, and profiles were associated with sociodemographic factors. Approximately 9% of children exhibited multiple co-occurring vulnerabilities. This study adds to our understanding of population-level distributions of children's early social-emotional health and identifies profiles of strengths and vulnerabilities that can inform future intervention efforts. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Profiles of children's social–emotional health at school entry and associated income, gender and language inequalities: a cross-sectional population-based study in British Columbia, Canada

PubMed Central

Guhn, Martin; Richardson, Chris G; Ark, Tavinder K; Shoveller, Jean

2017-01-01

Objectives Early identification of distinct patterns of child social–emotional strengths and vulnerabilities has the potential to improve our understanding of child mental health and well-being; however, few studies have explored natural groupings of indicators of child vulnerability and strengths at a population level. The purpose of this study was to examine heterogeneity in the patterns of young children's social and emotional health and investigate the extent to which sociodemographic characteristics were associated. Design Cross-sectional study based on a population-level cohort. Setting All kindergarten children attending public schools between 2004 and 2007 in British Columbia (BC), Canada. Participants 35 818 kindergarten children (age of 5 years) with available linked data from the Early Development Instrument (EDI), BC Ministry of Health and BC Ministry of Education. Outcome measure We used latent profile analysis (LPA) to identify distinct profiles of social–emotional health according to children's mean scores across eight social–emotional subscales on the EDI, a teacher-rated measure of children's early development. Subscales measured children's overall social competence, responsibility and respect, approaches to learning, readiness to explore, prosocial behaviour, anxiety, aggression and hyperactivity. Results Six social–emotional profiles were identified: (1) overall high social–emotional functioning, (2) inhibited-adaptive (3) uninhibited-adaptive, (4) inhibited-disengaged, (5) uninhibited-aggressive/hyperactive and (6) overall low social–emotional functioning. Boys, children with English as a second language (ESL) status and children with lower household income had higher odds of membership to the lower social–emotional functioning groups; however, this association was less negative among boys with ESL status. Conclusions Over 40% of children exhibited some vulnerability in early social–emotional health, and profiles were associated with sociodemographic factors. Approximately 9% of children exhibited multiple co-occurring vulnerabilities. This study adds to our understanding of population-level distributions of children's early social–emotional health and identifies profiles of strengths and vulnerabilities that can inform future intervention efforts. PMID:28751486

Assessing Wellbeing at School Entry Using the Strengths and Difficulties Questionnaire: Professional Perspectives

ERIC Educational Resources Information Center

White, Jane; Connelly, Graham; Thompson, Lucy; Wilson, Phil

2013-01-01

Background: Emotional and behavioural disorders in early childhood are related to poorer academic attainment and school engagement, and difficulties already evident at the point of starting school can affect a child's later social and academic development. Successful transfer from pre-school settings to primary education is helped by communication…

Superior Nonverbal Intelligence in Children with High-Functioning Autism or Asperger's Syndrome

ERIC Educational Resources Information Center

Chen, Fei; Planche, Pascale; Lemonnier, Eric

2010-01-01

Some early studies showed discordance in cognitive strengths and weaknesses in individuals with high-functioning autism (HFA) or Asperger's syndrome (AS). The present study administered the French version of Colored Raven's Progressive Matrices in 14 children with HFA/AS and in 26 chronological age matched peers with typical development. We found…

Running Records: Authentic Instruction in Early Childhood Education

ERIC Educational Resources Information Center

Shea, Mary

2012-01-01

The most effective way to understand what a child knows about the reading process is to take a running record. In "Running Records", Mary Shea demonstrates how teachers can use this powerful tool to design lessons that decrease reading difficulties, build on strengths, and stimulate motivation, ensuring that children develop self-sustaining…

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

PubMed

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

2016-05-01

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

Activity-Driven CNS Changes in Learning and Development

DTIC Science & Technology

1991-04-14

26 Stimulation of Phosphoinositide Turnover by Excitatory Amino Acids: Pharmacology, Development, and Role in Visual Cortical Plasticity. By...Hz for I sec. Immedi- ately following this tetanic stimulation , the strength of the synaptic connection (as tested with single-shock stimuli...increases up to about 5-fold. Most of this increase decays to a level of about 150-200% of baseline within a few minutes after tetanic stimulation . The early

Exercise, Hormones, and Skeletal Adaptations During Childhood and Adolescence

PubMed Central

Farr, Joshua N.; Laddu, Deepika R.; Going, Scott B.

2015-01-01

Although primarily considered a disorder of the elderly, emerging evidence suggests the antecedents of osteoporosis are established during childhood and adolescence. A complex interplay of genetic, environmental, hormonal and behavioral factors determines skeletal development, and a greater effort is needed to identify the most critical factors that establish peak bone strength. Indeed, knowledge of modifiable factors that determine skeletal development may permit optimization of skeletal health during growth and could potentially offset reductions in bone strength with aging. The peripubertal years represent a unique period when the skeleton is particularly responsive to loading exercises, and there is now overwhelming evidence that exercise can optimize skeletal development. While this is not controversial, the most effective exercise prescription and how much investment in this prescription is needed to significantly impact bone health continues to be debated. Despite considerable progress, these issues are not easy to address, and important questions remain unresolved. This review focuses on the key determinants of skeletal development, whether exercise during childhood and adolescence should be advocated as a safe and effective strategy for optimizing peak bone strength, and whether investment in exercise early in life protects against the development of osteoporosis and fractures later in life. PMID:25372373

Early-phase musculoskeletal adaptations to different levels of eccentric resistance after 8 weeks of lower body training.

PubMed

English, Kirk L; Loehr, James A; Lee, Stuart M C; Smith, Scott M

2014-11-01

Eccentric muscle actions are important to the development of muscle mass and strength and may affect bone mineral density (BMD). This study's purpose was to determine the relative effectiveness of five different eccentric:concentric load ratios to increase musculoskeletal parameters during early adaptations to resistance training. Forty male subjects performed a supine leg press and calf press training program 3 days week(-1) for 8 weeks. Subjects were matched for pre-training leg press 1-repetition maximum strength (1-RM) and randomly assigned to one of five training groups. Concentric training load (% 1-RM) was constant across groups, but within groups, eccentric load was 0, 33, 66, 100, or 138% of concentric load. Muscle mass (dual energy X-ray absorptiometry; DXA), strength (1-RM), and BMD (DXA) were measured pre- and post-training. Markers of bone metabolism were assessed pre-, mid- and post-training. The increase in leg press 1-RM in the 138% group (20 ± 4%) was significantly greater (P < 0.05) than the 0% (8 ± 3%), 33% (8 ± 5%) and 66% (8 ± 4%) groups, but not the 100% group (13 ± 6 %; P = 0.15). All groups, except the 0% group, increased calf press 1-RM (P < 0.05). Leg lean mass and greater trochanter BMD were increased only in the 138% group (P < 0.05). Early-phase adaptations to eccentric overload training include increases in muscle mass and site-specific increases in BMD and muscle strength which are not present or are less with traditional and eccentric underload training. Eccentric overload provides a robust musculoskeletal stimulus that may benefit bedridden patients, individuals recovering from injury or illness, and astronauts during spaceflight.

Strength of obesity prevention interventions in early care and education settings: A systematic review.

PubMed

Ward, Dianne S; Welker, Emily; Choate, Ashley; Henderson, Kathryn E; Lott, Megan; Tovar, Alison; Wilson, Amanda; Sallis, James F

2017-02-01

2010-2015; INTERNATIONAL: Given the high levels of obesity in young children, numbers of children in out-of-home care, and data suggesting a link between early care and education (ECE) participation and overweight/obesity, obesity prevention in ECE settings is critical. As the field has progressed, a number of interventions have been reviewed yet there is a need to summarize the data using more sophisticated analyses to answer questions on the effectiveness of interventions. We conducted a systematic review of obesity prevention interventions in center-based ECE settings published between 2010 and 2015. Our goal was to identify promising intervention characteristics associated with successful behavioral and anthropometric outcomes. A rigorous search strategy resulted in 43 interventions that met inclusion criteria. We developed a coding strategy to assess intervention strength, used a validated study quality assessment tool, and presented detailed descriptive information about interventions (e.g., target behaviors, intervention strategies, and mode of delivery). Intervention strength was positively correlated with reporting of positive anthropometric outcomes for physical activity, diet, and combined interventions, and parent engagement components increased the strength of these relationships. Study quality was modestly related to percent successful healthy eating outcomes. Relationships between intervention strength and behavioral outcomes demonstrated negative relationships for all behavioral outcomes. Specific components of intervention strength (number of intervention strategies, potential impact of strategies, frequency of use, and duration of intervention) were correlated with some of the anthropometric and parent engagement outcomes. The review provided tentative evidence that multi-component, multi-level ECE interventions with parental engagement are most likely to be effective with anthropometric outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Early Learning and Adaptive Behaviour in Toddlers with Down Syndrome: Evidence for an Emerging Behavioural Phenotype?

ERIC Educational Resources Information Center

Fidler, Deborah; Hepburn, Susan; Rogers, Sally

2006-01-01

Background: Though the Down syndrome behavioural phenotype has been described as involving relative strengths in visuo-spatial processing and sociability, and relative weaknesses in verbal skills and motor planning, the early emergence of this phenotypic pattern of strengths and weaknesses has not yet been fully explored. Method: In this study, we…

Parkour as a Donor Sport for Athletic Development in Youth Team Sports: Insights Through an Ecological Dynamics Lens.

PubMed

Strafford, Ben William; van der Steen, Pawel; Davids, Keith; Stone, Joseph Antony

2018-05-24

Analyses of talent development in sport have identified that skill can be enhanced through early and continued involvement in donor sports which share affordances (opportunities for action) with a performer's main target sport. Aligning key ideas of the Athletic Skills Model and ecological dynamics theory, we propose how the sport of parkour could provide a representative and adaptive platform for developing athletic skill (e.g. coordination, timing, balance, agility, spatial awareness and muscular strength). We discuss how youth sport development programmes could be (re) designed to include parkour-style activities, in order to develop general athletic skills in affordance-rich environments. It is proposed that team sports development programmes could particularly benefit from parkour-style training since it is exploratory and adaptive nature shapes utilisation of affordances for innovative and autonomous performance by athletes. Early introduction to varied, relevant activities for development of athleticism and skill, in a diversified training programme, would provide impetus for a fundamental shift away from the early specialisation approach favoured by traditional theories of skill acquisition and expertise in sport.

An Experimental Study of High Strength-High Volume Fly Ash Concrete for Sustainable Construction Industry

NASA Astrophysics Data System (ADS)

Kate, Gunavant K.; Thakare, Sunil B., Dr.

2017-08-01

Concrete is the most widely used building material in the construction of infrastructures such as buildings, bridges, highways, dams, and many other facilities. This paper reports the development, the basic idea, the main properties of high strength-high volume fly ash with application in concrete associated with the development and implementation of Sustainable Properties of High Volume Fly Ash Concrete (HVFAC) Mixtures and Early Age Shrinkage and mechanical properties of concrete for 7,28,56 and 90days. Another alternative to make environment-friendly concrete is the development of high strength-high-volume fly ash concrete which is an synthesized from materials of geological origin or by-product materials such as fly ash which is rich in silicon and aluminum. In this paper 6 concrete mixtures were produced to evaluate the effect of key parameters on the mechanical properties of concrete and its behavior. The study key parameters are; binder material content, cement replacement ratios, and the steel fibers used to High Volume Fly Ash mixtures for increasing performance of concrete.

Parental Depression, Overreactive Parenting, and Early Childhood Externalizing Problems: Moderation by Social Support.

PubMed

Taraban, Lindsay; Shaw, Daniel S; Leve, Leslie D; Natsuaki, Misaki N; Ganiban, Jody M; Reiss, David; Neiderhiser, Jenae M

2018-02-20

This study used a large (N = 519), longitudinal sample of adoptive families to test overreactive parenting as a mediator of associations between parental depressive symptoms and early childhood externalizing, and parents' social support satisfaction as a moderator. Maternal parenting (18 months) mediated the association between maternal depressive symptoms (9 months) and child externalizing problems (27 months). Paternal parenting was not a significant mediator. Unexpectedly, we found a cross-over effect for the moderating role of social support satisfaction, such that partners' social support satisfaction reduced the strength of the association between each parent's own depressive symptoms and overreactive parenting. Results point to the importance of accounting for broader family context in predicting early childhood parenting and child outcomes. © 2018 The Authors. Child Development © 2018 Society for Research in Child Development, Inc.

Optimization of Process Parameters for High Efficiency Laser Forming of Advanced High Strength Steels within Metallurgical Constraints

NASA Astrophysics Data System (ADS)

Sheikholeslami, Ghazal; Griffiths, Jonathan; Dearden, Geoff; Edwardson, Stuart P.

Laser forming (LF) has been shown to be a viable alternative to form automotive grade advanced high strength steels (AHSS). Due to their high strength, heat sensitivity and low conventional formability show early fractures, larger springback, batch-to-batch inconsistency and high tool wear. In this paper, optimisation of the LF process parameters has been conducted to further understand the impact of a surface heat treatment on DP1000. A FE numerical simulation has been developed to analyse the dynamic thermo-mechanical effects. This has been verified against empirical data. The goal of the optimisation has been to develop a usable process window for the LF of AHSS within strict metallurgical constraints. Results indicate it is possible to LF this material, however a complex relationship has been found between the generation and maintenance of hardness values in the heated zone. A laser surface hardening effect has been observed that could be beneficial to the efficiency of the process.

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

PubMed Central

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

2016-01-01

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

Adolescent Perception of Mothers' Parenting Strengths and Needs: A Cross-Cultural Approach to Curriculum Development for Parent Education

ERIC Educational Resources Information Center

Beckert, Troy E.; Strom, Paris S.; Strom, Robert D.

2007-01-01

Black, Hispanic, and White American early adolescents (N = 573) were administered the Parent Success Indicator. The performance of their mothers was rated for 60 items, included within six subscales, that consider Communication, Use of Time, Teaching, Frustration, Satisfaction, and Information Needs. Each racial group described favorable…

Effects of early whole-body vibration treatment on knee neuromuscular function and postural control after anterior cruciate ligament reconstruction: A randomized controlled trial.

PubMed

Pistone, Eugenio Maria; Laudani, Luca; Camillieri, Gianluca; Di Cagno, Alessandra; Tomassi, Gabriele; Macaluso, Andrea; Giombini, Arrigo

2016-11-11

To assess the effects of adding a whole-body vibration protocol at optimal frequency (WBV-OF) to a traditional rehabilitation programme (TRP) early after anterior cruciate ligament reconstruction, on maximal strength and balance, in comparison with a traditional rehabilitation programme. A total of 34 anterior cruciate ligament reconstructed patients with hamstring-tendon graft underwent either 4 weeks of WBV-OF training in addition to a traditional rehabilitation programme, or a traditional rehabilitation programme only, starting from the first month after surgery. Patients were assessed for maximal voluntary isometric strength during both knee extension and flexion and for balance on a force platform before, 1 month after treatment and at 3-month follow-up. Strength symmetry of the knee flexor muscles improved in WBV-OF+TRP patients more than in TRP patients 1 month after treatment (mean 66% (standard deviation (SD) 15) vs 58% SD 13), and also at the 3-month follow-up (mean 77% (SD 15) vs 64% (SD 15)), with no differences in balance improvements between the groups. Adding 4-weeks of WBV-OF to a traditional rehabilitation programme 1 month after surgery is effective in improving muscle strength of the knee flexor muscles. This early intervention may be incorporated into current rehabilitation to facilitate early strength recovery of anterior cruciate ligament reconstructed patients.

Emotional and behavioural problems in Swedish preschool children rated by preschool teachers with the Strengths and Difficulties Questionnaire (SDQ).

PubMed

Gustafsson, Berit M; Proczkowska-Björklund, Marie; Gustafsson, Per A

2017-04-21

There is a high risk that young children who show early signs of mental health problems develop symptoms in the same or overlapping areas some years later. The Strengths and Difficulties Questionnaire (SDQ) is widely used to screen externalizing and internalizing problems early in life. In Sweden 80-90% of all children aged 1-5 years go to preschool and preschool is thus an appropriate context for finding early signs of mental health problems among children. This study is part of a longitudinal project too investigate the frequency of emotional and behavioural problems for children between 1 and 5 years of age in Sweden. The SDQ including the impairment supplement questions were rated by preschool teachers too establish Swedish norms for SDQ in preschool children. The sample involved 815 children with a mean age of 42 months (SD = 16, range 13-71 months). 195 children were followed longitudinally for three years. There were significant differences between boys and girls on all subscales except for the Emotional subscale. The prevalence of behavioural problems was similar to other that in European countries, except for Prosocial behaviour, which was rated lower, and Conduct problems, rated higher. Swedish children were estimated to have more problems in the preschool setting, scored by preschool teachers. The development of behaviour over time differed for the different subscales of SDQ. The teacher version of the SDQ, for 2-4 year-olds, can be used as a screening instrument to identify early signs of emotional distress/behavioural problems in young children. Preschool teachers seem to be able to identify children with problematic behaviour with the use of SDQ at an early age. The development of behaviour over time differs for the different subscales of SDQ. The Swedish norms for SDQ are to a large extent, similar to findings from other European countries.

Physical self-esteem--a ten-year follow-up study from early adolescence to early adulthood.

PubMed

Raustorp, Anders; Lindwall, Magnus

2015-02-01

One variable that has been consistently associated with adolescents' physical activity is perceived activity competence. Perceived physical (or sport) competence is considered a sub-domain to the physical self-esteem or self-worth (i.e., a person's valuation of what is good and worthy in their self-description). This study aimed to describe levels of and inter-correlations among physical self-esteem, physical activity, and body mass index in a longitudinal design spanning adolescence to early adulthood. At mean ages of 12.7, 15.7, 17.7 and 22.7 years, we measured perceived physical self-esteem in 39 (22 boys) Swedish adolescents. Physical activity (steps/day) for four consecutive schooldays, height, and weight were also measured. No significant difference between the four time points for any variable of perceived physical self-esteem was seen, neither in boys nor girls. In general, all physical self-variables revealed non-linear trajectories across time, where the general trend was an increase during the younger ages followed by a decrease during older ages. At ages 12 and 15 years in boys and girls physical condition and physical strength as well as body attractiveness and physical strength, respectively, had the strongest correlations to physical self-esteem. At age 17 and 22 years sports competence had the strongest correlation to self-esteem in girls, while body attractiveness and physical strength had the strongest correlation to self-esteem in boys. An overall stability in physical self-esteem was found. However the impact of a sub-domain upon physical self-esteem vary during adolescence and early adulthood. Such information may be useful when creating physical activity programs that support and develop physical self-esteem.

Chemical vs. Physical Acceleration of Cement Hydration

PubMed Central

Bentz, Dale P.; Zunino, Franco; Lootens, Didier

2016-01-01

Cold weather concreting often requires the use of chemical accelerators to speed up the hydration reactions of the cement, so that setting and early-age strength development will occur in a timely manner. While calcium chloride (dihydrate – CaCl2·2H2O) is the most commonly used chemical accelerator, recent research using fine limestone powders has indicated their high proficiency for physically accelerating early-age hydration and reducing setting times. This paper presents a comparative study of the efficiency of these two approaches in accelerating hydration (as assessed via isothermal calorimetry), reducing setting times (Vicat needle), and increasing early-age mortar cube strength (1 d and 7 d). Both the CaCl2 and the fine limestone powder are used to replace a portion of the finest sand in the mortar mixtures, while keeping both the water-to-cement ratio and volume fractions of water and cement constant. Studies are conducted at 73.4 °F (23°C) and 50 °F (10 °C), so that activation energies can be estimated for the hydration and setting processes. Because the mechanisms of acceleration of the CaCl2 and limestone powder are different, a hybrid mixture with 1 % CaCl2 and 20 % limestone powder (by mass of cement) is also investigated. Both technologies are found to be viable options for reducing setting times and increasing early-age strengths, and it is hoped that concrete producers and contractors will consider the addition of fine limestone powder to their toolbox of techniques for assuring performance in cold weather and other concreting conditions where acceleration may be needed. PMID:28077884

Strengths, weaknesses, opportunities, and threats analysis of integrating the World Health Organization patient safety curriculum into undergraduate medical education in Pakistan: a qualitative case study

PubMed Central

2017-01-01

Purpose The purpose of this study was to conduct a strengths, weaknesses, opportunities, and threats (SWOT) analysis of integrating the World Health Organization (WHO) patient safety curriculum into undergraduate medical education in Pakistan. Methods A qualitative interpretive case study was conducted at Riphah International University, Islamabad, from October 2016 to June 2017. The study included 9 faculty members and 1 expert on patient safety. The interviews were audiotaped, and a thematic analysis of the transcripts was performed using NVivo software. Results Four themes were derived based on the need analysis model. The sub-themes derived from the collected data were arranged under the themes of strengths, weaknesses, opportunities, and threats, in accordance with the principles of SWOT analysis. The strengths identified were the need for a formal patient safety curriculum and its early integration into the undergraduate program. The weaknesses were faculty awareness and participation in development programs. The opportunities were an ongoing effort to develop an appropriate curriculum, to improve the current culture of healthcare, and to use the WHO curricular resource guide. The threats were attitudes towards patient safety in Pakistani culture, resistance to implementation from different levels, and the role of regulatory authorities. Conclusion The theme of patient safety needs to be incorporated early into the formal medical education curriculum, with the main goals of striving to do no harm and seeing mistakes as opportunities to learn. Faculty development activities need to be organized, and faculty members should to be encouraged to participate in them. The lack of a patient safety culture was identified as the primary reason for resistance to this initiative at many levels. The WHO curriculum, amended according to local institutional culture, can be implemented appropriately with support from the corresponding regulatory bodies. PMID:29284217

Robust regression and posterior predictive simulation increase power to detect early bursts of trait evolution.

PubMed

Slater, Graham J; Pennell, Matthew W

2014-05-01

A central prediction of much theory on adaptive radiations is that traits should evolve rapidly during the early stages of a clade's history and subsequently slowdown in rate as niches become saturated--a so-called "Early Burst." Although a common pattern in the fossil record, evidence for early bursts of trait evolution in phylogenetic comparative data has been equivocal at best. We show here that this may not necessarily be due to the absence of this pattern in nature. Rather, commonly used methods to infer its presence perform poorly when when the strength of the burst--the rate at which phenotypic evolution declines--is small, and when some morphological convergence is present within the clade. We present two modifications to existing comparative methods that allow greater power to detect early bursts in simulated datasets. First, we develop posterior predictive simulation approaches and show that they outperform maximum likelihood approaches at identifying early bursts at moderate strength. Second, we use a robust regression procedure that allows for the identification and down-weighting of convergent taxa, leading to moderate increases in method performance. We demonstrate the utility and power of these approach by investigating the evolution of body size in cetaceans. Model fitting using maximum likelihood is equivocal with regards the mode of cetacean body size evolution. However, posterior predictive simulation combined with a robust node height test return low support for Brownian motion or rate shift models, but not the early burst model. While the jury is still out on whether early bursts are actually common in nature, our approach will hopefully facilitate more robust testing of this hypothesis. We advocate the adoption of similar posterior predictive approaches to improve the fit and to assess the adequacy of macroevolutionary models in general.

Language and communication development in preschool children with visual impairment: A systematic review.

PubMed

Mosca, Renata; Kritzinger, Alta; van der Linde, Jeannie

2015-01-01

Language and communication difficulties of young children with visual impairment (VI) are ascribed to intellectual disability, multiple disabilities and autism spectrum disorder (ASD) rather than their sensory impairment. Consequently, the communication difficulties of children with VI may have been underestimated and undertreated. This report aims to critically appraise recent peer reviewed literature relating to communication and language development in children with VI. A systematic search of the literature (2003–2013) was completed using the PRISMA guidelines, and primary and secondary search phrases. Nine publications were reviewed in terms of the strength of recent evidence. Thematic analysis was used to describe the early language and communication characteristics of children with VI. All the selected articles (n = 9) were from developed countries and participants from seven of the studies had congenital VI. Five of the studies received an evidence level rating of III while four articles were rated as IIb. Two main themes emerged from the studies: early intervention, and multiple disabilities and ASD. Language and communication development is affected by VI, especially in the early stages of development. Speech-language therapists should therefore be included in early intervention for children with VI. Recent evidence on the early language and communication difficulties of children with VI exists, but children in developing countries with acquired VI appear to not be investigated. The identified language and communication developmental characteristics may assist speech-language therapists to build a knowledge base for participation in early intervention for young children with VI and their families.

StrengthsQuest in Application: The Experience of Four Educators. The Power of Teaching Students Using Strengths. The Quest for Strengths

ERIC Educational Resources Information Center

Henderson, Gloria

2005-01-01

Like Chip Anderson, whose essay you read earlier in this issue, I was initially taught to use the deficit-remediation model with my students. Even in that negative context, though, and with no exposure at all to strengths-based education, I unconsciously based my early teaching on four of my five Clifton StrengthsFinder signature themes:…

A specific inpatient aquatic physiotherapy program improves strength after total hip or knee replacement surgery: a randomized controlled trial.

PubMed

Rahmann, Ann E; Brauer, Sandra G; Nitz, Jennifer C

2009-05-01

To evaluate the effect of inpatient aquatic physiotherapy in addition to usual ward physiotherapy on the recovery of strength, function, and gait speed after total hip or knee replacement surgery. Pragmatic randomized controlled trial with blinded 6-month follow-up. Acute-care private hospital. People (n=65) undergoing primary hip or knee arthroplasty (average age, 69.6+/-8.2y; 30 men). Participants were randomly assigned to receive supplementary inpatient physiotherapy, beginning on day 4: aquatic physiotherapy, nonspecific water exercise, or additional ward physiotherapy. Strength, gait speed, and functional ability at day 14. At day 14, hip abductor strength was significantly greater after aquatic physiotherapy intervention than additional ward treatment (P=.001) or water exercise (P=.011). No other outcome measures were significantly different at any time point in the trial, but relative differences favored the aquatic physiotherapy intervention at day 14. No adverse events occurred with early aquatic intervention. A specific inpatient aquatic physiotherapy program has a positive effect on early recovery of hip strength after joint replacement surgery. Further studies are required to confirm these findings. Our research indicates that aquatic physiotherapy can be safely considered in this early postoperative phase.

In-season monitoring of hip and groin strength, health and function in elite youth soccer: Implementing an early detection and management strategy over two consecutive seasons.

PubMed

Wollin, Martin; Thorborg, Kristian; Welvaert, Marijke; Pizzari, Tania

2018-03-14

The primary purpose of this study was to describe an early detection and management strategy when monitoring in-season hip and groin strength, health and function in soccer. Secondly to compare pre-season to in-season test results. Longitudinal cohort study. Twenty-seven elite male youth soccer players (age: 15.07±0.73years) volunteered to participate in the study. Monitoring tests included: adductor strength, adductor/abductor strength ratio and hip and groin outcome scores (HAGOS). Data were recorded at pre-season and at 22 monthly intervals in-season. Thresholds for alerts to initiate further investigations were defined as any of the following: adductor strength reductions >15%, adductor/abductor strength ratio <0.90, and HAGOS subscale scores <75 out of 100 in any of the six subscales. Overall, 105 alerts were detected involving 70% of players. Strength related alerts comprised 40% and remaining 60% of alerts were related to HAGOS. Hip adductor strength and adductor/abductor strength ratio were lowest at pre-season testing and had increased significantly by month two (p<0.01, mean difference 0.26, CI95%: 0.12, 0.41N/kg and p<0.01, mean difference 0.09, CI95%: 0.04, 0.13 respectively). HAGOS subscale scores were lowest at baseline with all, except Physical Activity, showing significant improvements at time-point one (p<0.01). Most (87%) time-loss were classified minimal or mild. In-season monitoring aimed at early detection and management of hip and groin strength, health and function appears promising. Hip and groin strength, health and function improved quickly from pre-season to in-season in a high-risk population for ongoing hip and groin problems. Copyright © 2018 Sports Medicine Australia. All rights reserved.

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

PubMed

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

2013-01-01

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

The Association of Early Life Supplemental Nutrition With Lean Body Mass and Grip Strength in Adulthood: Evidence From APCAPS

PubMed Central

Kulkarni, Bharati; Kuper, Hannah; Radhakrishna, K. V.; Hills, Andrew P.; Byrne, Nuala M.; Taylor, Amy; Sullivan, Ruth; Bowen, Liza; Wells, Jonathan C.; Ben-Shlomo, Yoav; Davey Smith, George; Ebrahim, Shah; Kinra, Sanjay

2014-01-01

In the present study, we examined the associations of early nutrition with adult lean body mass (LBM) and muscle strength in a birth cohort that was established to assess the long-term impact of a nutrition program. Participants (n = 1,446, 32% female) were born near Hyderabad, India, in 29 villages from 1987 to 1990, during which time only intervention villages (n = 15) had a government program that offered balanced protein-calorie supplementation to pregnant women and children. Participants’ LBM and appendicular skeletal muscle mass were measured using dual energy x-ray absorptiometry; grip strength and information on lifestyle indicators, including diet and physical activity level, were also obtained. Ages (mean = 20.3 years) and body mass indexes (weight (kg)/height (m)2; mean = 19.5) of participants in 2 groups were similar. Current dietary energy intake was higher in the intervention group. Unadjusted LBM and grip strength were similar in 2 groups. After adjustment for potential confounders, the intervention group had lower LBM (β = −0.75; P = 0.03), appendicular skeletal muscle mass, and grip strength than did controls, but these differences were small in magnitude (<0.1 standard deviation). Multivariable regression analyses showed that current socioeconomic position, energy intake, and physical activity level had a positive association with adult LBM and muscle strength. This study could not detect a “programming” effect of early nutrition supplementation on adult LBM and muscle strength. PMID:24553777

Supporting Early Adolescent Learning and Social Strengths: Promoting Productive Contexts for Students At-Risk for EBD during the Transition to Middle School

ERIC Educational Resources Information Center

Farmer, Thomas W.; Hamm, Jill V.; Petrin, Robert A.; Robertson, Dylan; Murray, Robert A.; Meece, Judith L.; Brooks, Debbie Sprott

2010-01-01

This study involved a pilot examination of the impact of the Supporting Early Adolescent Learning and Social Strengths (SEALS) model on the 6th grade academic and social context following the transition to middle school. Two middle schools from a high poverty Appalachian school district were randomly assigned to the intervention and control…

PubMed Central

GALLUS, R.; DE CARLINI, M.; PICCIOTTI, P.M.; MUZZI, E.; CICIRIELLO, E.; ORZAN, E.; CONTI, G.

2016-01-01

SUMMARY Diagnosis of child permanent hearing impairment (PHI) can be made with extreme timeliness compared to the past thanks to improvements in PHI identification through newborn hearing screening programmes. It now becomes essential to provide an effective amplification as quickly as possible in order to restore auditory function and favour speech and language development. The early fitting of hearing aids and possible later cochlear implantation indeed prompts the development of central auditory pathways, connections with secondary sensory brain areas, as well as with motor and articulatory cortex. The aim of this paper is to report the results of a strategic analysis that involves identification of strengths, weaknesses, opportunities and threats regarding the process of achieving early amplification in all cases of significant childhood PHI. The analysis is focused on the Italian situation and is part of the Italian Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children". PMID:27054389

The Creative Curriculum[R] for Preschool: Developmental Continuum Assessment Toolkit for Ages 3-5.

ERIC Educational Resources Information Center

Dodge, Diane Trister; Colker, Laura J.; Heroman, Cate

Intended for use with the Creative Curriculum for Early Childhood, this integrated ongoing student assessment toolkit is designed for preschool teachers to help them focus on all aspects of a child's development, thereby giving them a way to ensure that all children in their classes are making progress. The assessment kit uses a strength-based…

Maturing as a Manager: Bringing Leadership and Management Together

ERIC Educational Resources Information Center

Hay, Susan

2012-01-01

Very few people in early years would dispute that the success of a child care centre is almost entirely down to the strength of the centre manager. At its most successful, management expands to leadership, where leaders are able to influence the behaviour of others for the purpose of achieving a goal. Leaders develop a special set of rather…

Best Practices in Community-Based Prevention for Youth Substance Reduction: Towards Strengths-Based Positive Development Policy

ERIC Educational Resources Information Center

Cheon, Jeong Woong

2008-01-01

Substance use among youth remains a major public health and safety concern. One fundamental way to address youth substance use prevention is to keep young people on a positive trajectory by engaging them in positive activities from early years of their childhood. In this article, the author offers a best practice analysis of systematic review…

Chapter 8: Soy Properties and Soy Wood Adhesives

Treesearch

Charles R. Frihart; Michael J. Birkeland

2014-01-01

Soy flour has been used for many years as a wood adhesive. Rapid development of petroleum-based infrastructure coupled with advancement of synthetic resin technology resulted in waning usage since the early 1960s. Discovery of using polyamidoamine–epichlorohydrin (PAE) resin as a co-reactant has been effective in increasing the wet bond strength of soy adhesives and...

The crucial effect of early-stage gelation on the mechanical properties of cement hydrates

NASA Astrophysics Data System (ADS)

Ioannidou, Katerina; Kanduč, Matej; Li, Lunna; Frenkel, Daan; Dobnikar, Jure; Del Gado, Emanuela

2016-07-01

Gelation and densification of calcium-silicate-hydrate take place during cement hydration. Both processes are crucial for the development of cement strength, and for the long-term evolution of concrete structures. However, the physicochemical environment evolves during cement formation, making it difficult to disentangle what factors are crucial for the mechanical properties. Here we use Monte Carlo and Molecular Dynamics simulations to study a coarse-grained model of cement formation, and investigate the equilibrium and arrested states. We can correlate the various structures with the time evolution of the interactions between the nano-hydrates during the preparation of cement. The novel emerging picture is that the changes of the physicochemical environment, which dictate the evolution of the effective interactions, specifically favour the early gel formation and its continuous densification. Our observations help us understand how cement attains its unique strength and may help in the rational design of the properties of cement and related materials.

The crucial effect of early-stage gelation on the mechanical properties of cement hydrates

PubMed Central

Ioannidou, Katerina; Kanduč, Matej; Li, Lunna; Frenkel, Daan; Dobnikar, Jure; Del Gado, Emanuela

2016-01-01

Gelation and densification of calcium–silicate–hydrate take place during cement hydration. Both processes are crucial for the development of cement strength, and for the long-term evolution of concrete structures. However, the physicochemical environment evolves during cement formation, making it difficult to disentangle what factors are crucial for the mechanical properties. Here we use Monte Carlo and Molecular Dynamics simulations to study a coarse-grained model of cement formation, and investigate the equilibrium and arrested states. We can correlate the various structures with the time evolution of the interactions between the nano-hydrates during the preparation of cement. The novel emerging picture is that the changes of the physicochemical environment, which dictate the evolution of the effective interactions, specifically favour the early gel formation and its continuous densification. Our observations help us understand how cement attains its unique strength and may help in the rational design of the properties of cement and related materials. PMID:27417911

A longitudinal study of bone area, content, density, and strength development at the radius and tibia in children 4-12 years of age exposed to recreational gymnastics.

PubMed

Jackowski, S A; Baxter-Jones, A D G; Gruodyte-Raciene, R; Kontulainen, S A; Erlandson, M C

2015-06-01

This study investigated the long-term relationship between the exposure to childhood recreational gymnastics and bone measures and bone strength parameters at the radius and tibia. It was observed that individuals exposed to recreational gymnastics had significantly greater total bone content and area at the distal radius. No differences were observed at the tibia. This study investigated the relationship between exposure to early childhood recreational gymnastics with bone measures and bone strength development at the radius and tibia. One hundred twenty seven children (59 male, 68 female) involved in either recreational gymnastics (gymnasts) or other recreational sports (non-gymnasts) between 4 and 6 years of age were recruited. Peripheral quantitative computed tomography (pQCT) scans of their distal and shaft sites of the forearm and leg were obtained over 3 years, covering the ages of 4-12 years at study completion. Multilevel random effects models were constructed to assess differences in the development of bone measures and bone strength measures between those exposed and not exposed to gymnastics while controlling for age, limb length, weight, physical activity, muscle area, sex, and hours of training. Once age, limb length, weight, muscle area, physical activity, sex, and hours of training effects were controlled, it was observed that individuals exposed to recreational gymnastics had significantly greater total bone area (18.0 ± 7.5 mm(2)) and total bone content (6.0 ± 3.0 mg/mm) at the distal radius (p < 0.05). This represents an 8-21 % benefit in ToA and 8-15 % benefit to ToC from 4 to 12 years of age. Exposure to recreational gymnastics had no significant effect on bone measures at the radius shaft or at the tibia (p > 0.05). Exposure to early life recreational gymnastics provides skeletal benefits to distal radius bone content and area. Thus, childhood recreational gymnastics exposure may be advantageous to bone development at the wrist.

Poverty and Health Disparities for American Indian and Alaska Native Children: Current Knowledge and Future Prospects

PubMed Central

Sarche, Michelle; Spicer, Paul

2008-01-01

This report explores the current state of knowledge regarding inequalities and their effect on American Indian and Alaska Native children, underscoring gaps in our current knowledge and the opportunities for early intervention to begin to address persistent challenges in young American Indian and Alaska Native children’s development. This overview documents demographic, social, health, and health care disparities as they affect American Indian and Alaska Native children, the persistent cultural strengths that must form the basis for any conscientious intervention effort, and the exciting possibilities for early childhood interventions. PMID:18579879

ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie; Wilkinson, Allen

2012-01-01

Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests.

Microstructural and strength improvements through the use of Na{sub 2}CO{sub 3} in a cementless Ca(OH){sub 2}-activated Class F fly ash system

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

Jeon, Dongho; Jun, Yubin; Jeong, Yeonung

2015-01-15

This study explores the beneficial effects of Na{sub 2}CO{sub 3} as an additive for microstructural and strength improvements in a Ca(OH){sub 2}-activated fly ash system. NaOH-activated fly ash samples were also tested to compare the effect of Na{sub 2}CO{sub 3}. Compressive strength testing, XRD, SEM/BSE/EDS, {sup 29}Si/{sup 27}Al MAS-NMR, MIP and TGA were performed. The testing results indicate that the use of Na{sub 2}CO{sub 3} for Ca(OH){sub 2}-activation led to a noticeable improvement in strength and microstructure, primarily due to (1) more dissolution of raw fly ash at an early age, (2) more formation of C–S–H [or C–S–H(I)], (3) porositymore » reduction, and (4) pore-size refinement. We also found that (1) an early high alkalinity from the NaOH formation was not a major cause of strength, (2) geopolymer was not formed despite the early NaOH formation, and (3) no visible pore-filling action of CaCO{sub 3} was observed. However, Na{sub 2}CO{sub 3} did not produce any improvement in strength for NaOH-activated fly ash. -- Highlights: •The use of Na{sub 2}CO{sub 3} significantly improved strength and microstructure. •The use of Na{sub 2}CO{sub 3} induced more dissolution of raw fly ash at early ages. •The use of Na{sub 2}CO{sub 3} promoted more C–S–H [or C–S–H(I)] formation. •The use of Na{sub 2}CO{sub 3} reduced total porosity and refined pore-size distribution. •The use of Na{sub 2}CO{sub 3} produced neither geopolymer formations nor pore-filling actions from CaCO{sub 3}.« less

Early return to baseline range of motion and strength after anterior shoulder instability surgery: a Multicenter Orthopaedic Outcomes Network (MOON) shoulder group cohort study.

PubMed

Buckwalter V, Joseph A; Wolf, Brian R; Glass, Natalie; Bollier, Matt; Kuhn, John E; Hettrich, Carolyn M

2018-03-23

Patients often return to higher-level activities and sports at 4 to 8 months after anterior shoulder stabilization procedures. It is unknown what percentage of patients have regained normal function at this time frame and what factors predict residual deficits, range of motion (ROM), and strength after anterior shoulder instability surgery. Ten participating sites throughout the United States enrolled patients in a prospective cohort study including primary, revision, arthroscopic, and open anterior stabilization procedures. Baseline demographic data and patient outcomes questionnaires were collected with initial physical examination, treatment, surgical findings, and surgical repair details. At the 6-month follow-up visit, ROM and strength measurements were collected and compared with preoperative measurements. There were 348 patients identified who underwent surgical treatment for anterior shoulder instability. Of these, 259 patients (74.0%) returned to baseline, and 89 (26.0%) did not return to baseline shoulder ROM (≥20° loss of ROM) or strength. A higher Beighton score (P = .01) and number of dislocations (P < .01) were associated with failure to regain baseline ROM and strength at early follow-up. No surgical variables were found to influence return to baseline function, including open vs. arthroscopic surgery, primary vs. revision surgery, and number of suture anchors. By 4 to 8 months postoperatively, 76% of patients return to baseline ROM, 98% return to baseline strength, and 74% return to both baseline ROM and strength. An increased number of dislocations and generalized joint laxity were associated with failure to return to baseline ROM and strength at early follow-up after anterior shoulder instability surgery. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Macroalgal spore dysfunction: ocean acidification delays and weakens adhesion.

PubMed

Guenther, Rebecca; Miklasz, Kevin; Carrington, Emily; Martone, Patrick T

2018-04-01

Early life stages of marine organisms are predicted to be vulnerable to ocean acidification. For macroalgae, reproduction and population persistence rely on spores to settle, adhere and continue the algal life cycle, yet the effect of ocean acidification on this critical life stage has been largely overlooked. We explicitly tested the biomechanical impact of reduced pH on early spore adhesion. We developed a shear flume to examine the effect of reduced pH on spore attachment time and strength in two intertidal rhodophyte macroalgae, one calcified (Corallina vancouveriensis) and one noncalcified (Polyostea robusta). Reduced pH delayed spore attachment of both species by 40%-52% and weakened attachment strength in C. vancouveriensis, causing spores to dislodge at lower flow-induced shear forces, but had no effect on the attachment strength of P. robusta. Results are consistent with our prediction that reduced pH disrupts proper curing and gel formation of spore adhesives (anionic polysaccharides and glycoproteins) via protonation and cation displacement, although experimental verification is needed. Our results demonstrate that ocean acidification negatively, and differentially, impacts spore adhesion in two macroalgae. If results hold in field conditions, reduced ocean pH has the potential to impact macroalgal communities via spore dysfunction, regardless of the physiological tolerance of mature thalli. © 2017 Phycological Society of America.

Early childhood diarrhoeal diseases and cognition: are we missing the rest of the iceberg?

PubMed

MacIntyre, Jessica; McTaggart, Jennifer; Guerrant, Richard L; Goldfarb, David M

2014-11-01

Risk factors which interfere with cognitive function are especially important during the first 2 years of life - a period referred to as early child development and a time during which rapid growth and essential development occur. Malnutrition, a condition whose effect on cognitive function is well known, has been shown to be part of a vicious cycle with diarrhoeal diseases, and the two pathologies together continue to be the leading cause of illness and death in young children in developing countries. This paper reviews the burden of early childhood diarrhoeal diseases globally and the emerging evidence of their relationship with global disparities in neurocognitive development. The strength of evidence which indicates that the severe childhood diarrhoeal burden may be implicated in cognitive impairment of children from low- and middle-income counties is discussed. Findings suggest that greater investment in multi-site, longitudinal enteric infection studies that assess long-term repercussions are warranted. Furthermore, economic analyses using the concept of human capital should play a key role in advancing our understanding of the breadth and complexities of the health, social and economic ramifications of early childhood diarrhoeal diseases and enteric infections. This broadened awareness can serve to help advocate for more effective interventions, particularly in developing economies.

Role of primary afferents in the developmental regulation of motor axon synapse numbers on Renshaw cells

PubMed Central

Siembab, Valerie C.; Gomez-Perez, Laura; Rotterman, Travis M.; Shneider, Neil A.; Alvarez, Francisco J.

2015-01-01

Motor function in mammalian species depends on the maturation of spinal circuits formed by a large variety of interneurons that regulate motoneuron firing and motor output. Interneuron activity is in turn modulated by the organization of their synaptic inputs, but the principles governing the development of specific synaptic architectures unique to each premotor interneuron are unknown. For example, Renshaw cells receive, at least in the neonate, convergent inputs from sensory afferents (likely Ia) and motor axons raising the question of whether they interact during Renshaw cell development. In other well-studied neurons, like Purkinje cells, heterosynaptic competition between inputs from different sources shapes synaptic organization. To examine the possibility that sensory afferents modulate synaptic maturation on developing Renshaw cells, we used three animal models in which afferent inputs in the ventral horn are dramatically reduced (Er81(−/−) knockout), weakened (Egr3(−/−) knockout) or strengthened (mlcNT3(+/−) transgenic). We demonstrate that increasing the strength of sensory inputs on Renshaw cells prevents their de-selection and reduces motor axon synaptic density and, in contrast, absent or diminished sensory afferent inputs correlate with increased densities of motor axons synapses. No effects were observed on other glutamatergic inputs. We conclude that the early strength of Ia synapses influences their maintenance or weakening during later development and that heterosynaptic influences from sensory synapses during early development regulates the density and organization of motor inputs on mature Renshaw cells. PMID:26660356

Language and communication development in preschool children with visual impairment: A systematic review

PubMed Central

Kritzinger, Alta; van der Linde, Jeannie

2015-01-01

Background Language and communication difficulties of young children with visual impairment (VI) are ascribed to intellectual disability, multiple disabilities and autism spectrum disorder (ASD) rather than their sensory impairment. Consequently, the communication difficulties of children with VI may have been underestimated and undertreated. Objectives This report aims to critically appraise recent peer reviewed literature relating to communication and language development in children with VI. Method A systematic search of the literature (2003–2013) was completed using the PRISMA guidelines, and primary and secondary search phrases. Nine publications were reviewed in terms of the strength of recent evidence. Thematic analysis was used to describe the early language and communication characteristics of children with VI. Results All the selected articles (n = 9) were from developed countries and participants from seven of the studies had congenital VI. Five of the studies received an evidence level rating of III while four articles were rated as IIb. Two main themes emerged from the studies: early intervention, and multiple disabilities and ASD. Language and communication development is affected by VI, especially in the early stages of development. Speech-language therapists should therefore be included in early intervention for children with VI. Conclusion Recent evidence on the early language and communication difficulties of children with VI exists, but children in developing countries with acquired VI appear to not be investigated. The identified language and communication developmental characteristics may assist speech-language therapists to build a knowledge base for participation in early intervention for young children with VI and their families. PMID:26809155

Tendon-Holding Capacities of Two Newly Designed Implants for Tendon Repair: An Experimental Study on the Flexor Digitorum Profundus Tendon of Sheep

PubMed Central

Ağır, İsmail; Aytekin, Mahmut Nedim; Başçı, Onur; Çaypınar, Barış; Erol, Bülent

2014-01-01

Background: Two main factors determine the strength of tendon repair; the tensile strength of material and the gripping capacity of a suture configuration. Different repair techniques and suture materials were developed to increase the strength of repairs but none of techniques and suture materials seem to provide enough tensile strength with safety margins for early active mobilization. In order to overcome this problem tendon suturing implants are being developed. We designed two different suturing implants. The aim of this study was to measure tendon-holding capacities of these implants biomechanically and to compare them with frequently used suture techniques Materials and Methods: In this study we used 64 sheep flexor digitorum profundus tendons. Four study groups were formed and each group had 16 tendons. We applied model 1 and model 2 implant to the first 2 groups and Bunnell and locking-loop techniques to the 3rd and 4th groups respectively by using 5 Ticron sutures. Results: In 13 tendons in group 1 and 15 tendons in group 2 and in all tendons in group 3 and 4, implants and sutures pulled out of the tendon in longitudinal axis at the point of maximum load. The mean tensile strengths were the largest in group 1 and smallest in group 3. Conclusion: In conclusion, the new stainless steel tendon suturing implants applied from outside the tendons using steel wires enable a biomechanically stronger repair with less tendon trauma when compared to previously developed tendon repair implants and the traditional suturing techniques. PMID:25067965

Quality assurance in transition.

PubMed

Blumenfeld, S N

1993-06-01

This paper outlines the early approaches to quality assurance, and its transition from business to health care. It then describes the development of the more recent trends in quality assurance of Total Quality Management and Continuous Quality Improvement and discusses the strengths and weaknesses of these approaches. The paper then goes on to show how these approaches have been modified for application to peripheral health services in developing countries through the work of the Primary Health Care Operations Research Project and the Quality Assurance Project.

[The effect of bemithyl on the onthogenesis of rats].

PubMed

Spasov, A A; Bugaeva, L I; Denisova, T D; Smirnova, L A

2005-01-01

Female rats were treated with bemithyl (20 and 100 mg/kg) via a gastric tube during a 16-day period of lactation. It was found that the drug is transferred with breast milk to the organism of newborns, which leads to nonuniformities in their development. Among the early effects of bemithyl, most pronounced is the stimulating action upon maturation (muscle strength) and the development of sensor-locomotor reflexes; in the spectrum of long-term effects, the drug influence upon pubescence processes was manifested.

Optimum designs for superpressure balloons

NASA Astrophysics Data System (ADS)

Smith, M. S.; Rainwater, E. L.

2004-01-01

The elastica shape is now well known to be the best basic shape for superpressure balloon design. This shape, also known as the pumpkin, or natural shape for balloons, has been well understood since the early 1900s when it was applied to the determination of the shape of descending parachutes. The elastica shape was also investigated in the 1950s when high strength films were used to produce superpressure cylinder balloons. The need for uniform stress distribution in shells of early superpressure balloons led to a long period of the development of spherical superpressure balloons. Not until the late 1970s was the elastica shape revisited for the purpose of the producing superpressure balloons. This paper will review various development efforts in the field of superpressure design and will elaborate on the current state-of-the-art with suggestions for future developments.

The varieties of religious development in adulthood: a longitudinal investigation of religion and rational choice.

PubMed

McCullough, Michael E; Enders, Craig K; Brion, Sharon L; Jain, Andrea R

2005-07-01

The authors used growth mixture models to study religious development during adulthood (ages 27-80) in a sample of individuals who were identified during childhood as intellectually gifted. The authors identified 3 discrete trajectories of religious development: (a) 40% of participants belonged to a trajectory class characterized by increases in religiousness until midlife and declines in later adulthood; (b) 41% of participants belonged to a trajectory class characterized by very low religiousness in early adulthood and age-related decline; and (c) 19% of participants belonged to a trajectory class characterized by high religiousness in early adulthood and age-related increases. Gender, strength of religious upbringing, number of children, marrying, and agreeableness predicted membership in the trajectory classes. Results were largely consistent with the rational choice theory of religious involvement.

How long does it take to become fit?

PubMed Central

Pearn, J

1980-01-01

To become fit an individual must generate optimal muscle strength and must develop cardiopulmonary reserve, or stamina. Physical fitness programmes require motivation, a graded series of appropriately designed exercises, and scientific surveillance. Motivation and efficiency in fitness programmes depends on early positive feedback to participants, confirming that stamina and strength are developing. A practical field experiment was performed to determine the minimum time that healthy young adults require to reach an initial plateau in objective measures of fitness. Fifty male university undergraduates were studied during an annual volunteer military training camp. Thirty had volunteered to take part in the fitness programme; the remaining 20 had initially rejected the offer but underwent the programme as part of their military training and acted as unmotivated controls. All the subjects became fit within 14 days of starting training, with objective improvement in both absolute strength and pulse recovery times. Non-motivated individuals, training with motivated individuals for 20 minutes each day, can therefore achieve levels of fitness indistinguishable from those of healthy highly motivated subjects. Fitness programmes must be carefully supervised, however, with medical examinations for those about to undergo vigorous exercise. PMID:7437862

Phase imaging of mechanical properties of live cells (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wax, Adam

2017-02-01

The mechanisms by which cells respond to mechanical stimuli are essential for cell function yet not well understood. Many rheological tools have been developed to characterize cellular viscoelastic properties but these typically require direct mechanical contact, limiting their throughput. We have developed a new approach for characterizing the organization of subcellular structures using a label free, noncontact, single-shot phase imaging method that correlates to measured cellular mechanical stiffness. The new analysis approach measures refractive index variance and relates it to disorder strength. These measurements are compared to cellular stiffness, measured using the same imaging tool to visualize nanoscale responses to flow shear stimulus. The utility of the technique is shown by comparing shear stiffness and phase disorder strength across five cellular populations with varying mechanical properties. An inverse relationship between disorder strength and shear stiffness is shown, suggesting that cell mechanical properties can be assessed in a format amenable to high throughput studies using this novel, non-contact technique. Further studies will be presented which include examination of mechanical stiffness in early carcinogenic events and investigation of the role of specific cellular structural proteins in mechanotransduction.

Slab replacement maturity guidelines.

DOT National Transportation Integrated Search

2014-04-01

This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

The 3 "C" Design Model for Networked Collaborative E-Learning: A Tool for Novice Designers

ERIC Educational Resources Information Center

Bird, Len

2007-01-01

This paper outlines a model for online course design aimed at the mainstream majority of university academics rather than at the early adopters of technology. It has been developed from work at Coventry Business School where tutors have been called upon to design online modules for the first time. Like many good tools, the model's key strength is…

Three-Dimensional Rheological Structure of North China Craton Determined by Integration of Multiple observations: Controlling Role for Lithospheric Rifting

NASA Astrophysics Data System (ADS)

Xiong, X.; Shan, B.; Li, Y.

2017-12-01

The North China Craton (NCC) has undergone significant lithospheric rejuvenation in late Mesozoic and Cenozoic, one feature of which is the widespread extension and rifting. The extension is distinct between the two parts of NCC: widespread rifting in the eastern NCC and localized narrow rifting in the west. The mechanism being responsible for this difference is uncertain and highly debated. Since lithospheric deformation can be regarded as the response of lithosphere to various dynamic actions, the rheological properties of lithosphere must have a fundamental influence on its tectonics and deformation behavior. In this study, we investigated the 3D thermal and rheological structure of NCC by developing a model integrating several geophysical observables (such as surface heatflow, regional elevation, gravity and geoid anomalies, and seismic tomography models). The results exhibit obvious lateral variation in rheological structure between the eastern and western NCC. The overall lithospheric strength is higher in the western NCC than in the east. Despite of such difference in rheology, both parts of NCC are characterized by mantle dominated strength regime, which facilitates the development of narrow rifting. Using ancient heatflow derived from mantle xenoliths studies, and taking the subduction-related dehydration reactions during Mesozoic into account, we constructed the thermal and rheological structure of NCC in Ordovician, early Cretaceous and early Cenozoic. Combining the evidence from numerical simulations, we proposed an evolution path of the rifting in NCC. The lithosphere of NCC in Ordovician was characterized by a normal craton features: low geotherm, high strength and mantle dominated regime. During Jurassic and Cretaceous, the mantle lithosphere in the eastern NCC was hydrated by fluid released by the suduction of the Pacific plate, resulting in weakening of the lithosphere and a transition from mantle dominated to crust dominated regime, which facilitated the development of metamorphic core complex extension. The rifting in eastern NCC experienced a further transition to the wide rifting style under a low strain rate environment during early Cenozoic. In contrast, the western NNC has been kept mantle dominated regime, leading to a localized narrow rifting.

Acute Postexercise Time Course Responses of Hypertrophic vs. Power-Endurance Squat Exercise Protocols on Maximal and Rapid Torque of the Knee Extensors.

PubMed

Conchola, Eric C; Thiele, Ryan M; Palmer, Ty B; Smith, Doug B; Thompson, Brennan J

2015-05-01

The aim of this study was to examine the effects of a medium-intensity high-volume vs. explosive squat protocol on the postexercise time course responses of maximal and rapid strength of the knee extensors. Seventeen resistance-trained men (mean ± SD: age = 22.0 ± 2.6 years) performed maximal voluntary contractions (MVCs) of the knee extensors before and after performing a squat workout using either a low-intensity fast velocity (LIFV) (5 × 16 at 40% 1 repetition maximum) or a traditional high-intensity slow velocity (TISV) (5 × 8 at 80% 1RM) exercise protocol. For each MVC, peak torque (PT), peak rate of torque development (RTDpeak), absolute (RTDabs), and relative RTD (RTDnorm) at early (0-50 milliseconds) and late (100-200 milliseconds) phases of muscle contraction were examined at pre- (Pre) and post-exercise at 0, 7, 15, and 30 (Post0...30) minutes. There were no intensity × time interactions for any variables (p = 0.098-0.832). Peak torque was greater at Pre than Post0 and Post7 (p = 0.001-0.016) but was not greater than Post15 and Post30 (p = 0.010-0.189). RTDpeak and early absolute RTD (RTD50abs) were greater at Pre than all postexercise time phases (p = 0.001-0.050); however, later absolute RTD (RTD100-200abs) was only greater at Pre than Post0 and Post30 (p = 0.013-0.048). Early relative RTD (RTD50norm) was only higher at Pre compared with Post0 (p = 0.023), whereas no differences were observed for later relative RTD (RTD100-200norm) (p = 0.920-0.990). Low-intensity fast velocity and TISV squat protocols both yielded acute decreases in maximal and rapid strength capacities following free-weight squats, with rapid strength showing slower recovery characteristics than maximal strength.

Gymnastics participation is associated with skeletal benefits in the distal forearm: a 6-month study using peripheral Quantitative Computed Tomography.

PubMed

Burt, L A; Ducher, G; Naughton, G A; Courteix, D; Greene, D A

2013-12-01

Musculoskeletal development of the upper limbs during exposure to weight-bearing loading is under-researched during early pubescent growth. The purpose was to assess the changes in upper body musculoskeletal strength in young girls following 6 months of non-elite gymnastics participation. Eighty-four girls, 6-12 years were divided into groups based on gymnastics participation: high-training (HGYM, 6-16 hr/wk), low-training (LGYM, 1-5 hr/wk), and non-gymnasts (NONGYM). Volumetric BMD, bone geometry, estimated bone strength and muscle size were assessed at the non-dominant forearm (4% and 66% radius and ulna) with pQCT. DXA assessed aBMD and body composition. Tests for explosive power, muscle strength, and endurance were also performed. Interaction effects were observed in all variables at the 4% radius. At the 66% ulna, HGYM and LGYM had greater bone mass, size and bone strength than NONGYM, furthermore a dose-response relationship was observed at this location. Body composition was better for HGYM than LGYM and NONGYM, however muscle function was better for HGYM and LGYM than NONGYM. The greatest changes were obtained with more than one gymnastics class per week. Separating gymnastics participation-related changes from those associated with normal growth and development remains difficult, particularly at the 4% radius.

Guinea pig models for translation of the developmental origins of health and disease hypothesis into the clinic.

PubMed

Morrison, Janna L; Botting, Kimberley J; Darby, Jack R T; David, Anna L; Dyson, Rebecca M; Gatford, Kathryn L; Gray, Clint; Herrera, Emilio A; Hirst, Jonathan J; Kim, Bona; Kind, Karen L; Krause, Bernardo J; Matthews, Stephen G; Palliser, Hannah K; Regnault, Timothy R H; Richardson, Bryan S; Sasaki, Aya; Thompson, Loren P; Berry, Mary J

2018-04-06

Over 30 years ago Professor David Barker first proposed the theory that events in early life could explain an individual's risk of non-communicable disease in later life: the developmental origins of health and disease (DOHaD) hypothesis. During the 1990s the validity of the DOHaD hypothesis was extensively tested in a number of human populations and the mechanisms underpinning it characterised in a range of experimental animal models. Over the past decade, researchers have sought to use this mechanistic understanding of DOHaD to develop therapeutic interventions during pregnancy and early life to improve adult health. A variety of animal models have been used to develop and evaluate interventions, each with strengths and limitations. It is becoming apparent that effective translational research requires that the animal paradigm selected mirrors the tempo of human fetal growth and development as closely as possible so that the effect of a perinatal insult and/or therapeutic intervention can be fully assessed. The guinea pig is one such animal model that over the past two decades has demonstrated itself to be a very useful platform for these important reproductive studies. This review highlights similarities in the in utero development between humans and guinea pigs, the strengths and limitations of the guinea pig as an experimental model of DOHaD and the guinea pig's potential to enhance clinical therapeutic innovation to improve human health. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

The Risk Factors of Performance-Based Early Frailty in Midlife and Older Age.

PubMed

Peterson, Matthew J

2018-01-01

Background: Identifying impairments prior to onset of physical frailty may inform targeted interventions. An objective, clinically feasible early frailty measure, termed performance-based early frailty (PBEF) was developed, and antecedent and current risk factors were examined. Method: Data were from N = 104 participants of the Fels Longitudinal Study. PBEF was derived from age-specific cut points for time to complete five chair stands and walk four meters. "Pre-PBEF" and "PBEF" were defined as impairment in one or both measures, respectively. Candidate PBEF risk factors included body composition, health and quality of life, grip strength, and biomarker measures. Results: Pre-PBEF was identified in 26% and 30% of midlife and older adults, and PBEF was identified in 11% and 14% of midlife and older adults, respectively. When predicting midlife PBEF, only current physical activity was significant (odds ratio [OR] = 0.18). In older adults, PBEF status was predicted by previous heavier drinking (OR = 3.09), previous better grip strength (OR = 0.92), current poorer sleep habits (OR = 1.19), and current higher C-reactive protein concentrations (OR = 1.20). Conclusion: Differing age group patterns of predictors emerged, suggesting that PBEF in midlife is likely a state influenced by current health status, whereas older age PBEF is influenced by both current and antecedent factors.

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

Early life vitamin D depletion alters the postnatal response to skeletal loading in growing and mature bone

PubMed Central

Buckley, Harriet; Owen, Robert; Marin, Ana Campos; Lu, Yongtau; Eyles, Darryl; Lacroix, Damien; Reilly, Gwendolen C.; Skerry, Tim M.; Bishop, Nick J.

2018-01-01

There is increasing evidence of persistent effects of early life vitamin D exposure on later skeletal health; linking low levels in early life to smaller bone size in childhood as well as increased fracture risk later in adulthood, independently of later vitamin D status. A major determinant of bone mass acquisition across all ages is mechanical loading. We tested the hypothesis in an animal model system that early life vitamin D depletion results in abrogation of the response to mechanical loading, with consequent reduction in bone size, mass and strength during both childhood and adulthood. A murine model was created in which pregnant dams were either vitamin D deficient or replete, and their offspring moved to a vitamin D replete diet at weaning. Tibias of the offspring were mechanically loaded and bone structure, extrinsic strength and growth measured both during growth and after skeletal maturity. Offspring of vitamin D deplete mice demonstrated lower bone mass in the non loaded limb and reduced bone mass accrual in response to loading in both the growing skeleton and after skeletal maturity. Early life vitamin D depletion led to reduced bone strength and altered bone biomechanical properties. These findings suggest early life vitamin D status may, in part, determine the propensity to osteoporosis and fracture that blights later life in many individuals. PMID:29370213

Factors associated with grip strength decline in older adults.

PubMed

Sternäng, Ola; Reynolds, Chandra A; Finkel, Deborah; Ernsth-Bravell, Marie; Pedersen, Nancy L; Dahl Aslan, Anna K

2015-03-01

Few studies have examined associations of multi-faceted demographic, health and lifestyle factors with long-term change in grip strength performance across the adult lifespan. The aim of this study was to examine the associations of risk factors in specific parts of the adult lifespan (e.g. in early midlife, in late midlife and in old adulthood) separately for women and men. Data came from the longitudinal Swedish Adoption/Twin Study of Aging (SATSA). Grip strength performance was followed in 849 participants who were 50-88 years of age at baseline. The follow-up period with seven waves of data of grip strength was 22 years, and the risk factors were measured up to 20 years before the assessment of grip strength. Latent growth modelling was used for the longitudinal analyses. A gender difference in the type of factors associated with grip strength performance and development across the adult lifespan was found. Significant factors for the age slopes for women were stress, smoking and dementia. For men, marital status, mean arterial pressure, physical activity at work and having a chronic disorder were of importance. These factors varied in their associations with grip strength across the adult lifespan. Factors measured earlier in adulthood were associated with grip strength decline in late midlife and old adulthood. Gender-specific patterns of risk factors suggest that it may be worthwhile to conduct research on grip and muscle strength (and biological vitality) separately for men and women. © The Author 2014. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

National Quality Measures for Child Mental Health Care: Background, Progress, and Next Steps

PubMed Central

Murphy, J. Michael; Scholle, Sarah Hudson; Hoagwood, Kimberly Eaton; Sachdeva, Ramesh C.; Mangione-Smith, Rita; Woods, Donna; Kamin, Hayley S.; Jellinek, Michael

2013-01-01

OBJECTIVE: To review recent health policies related to measuring child health care quality, the selection processes of national child health quality measures, the nationally recommended quality measures for child mental health care and their evidence strength, the progress made toward developing new measures, and early lessons learned from these national efforts. METHODS: Methods used included description of the selection process of child health care quality measures from 2 independent national initiatives, the recommended quality measures for child mental health care, and the strength of scientific evidence supporting them. RESULTS: Of the child health quality measures recommended or endorsed during these national initiatives, only 9 unique measures were related to child mental health. CONCLUSIONS: The development of new child mental health quality measures poses methodologic challenges that will require a paradigm shift to align research with its accelerated pace. PMID:23457148

Rigidity in gender-typed behaviors in early childhood: a longitudinal study of ethnic minority children.

PubMed

Halim, May Ling; Ruble, Diane; Tamis-LeMonda, Catherine; Shrout, Patrick E

2013-01-01

A key prediction of cognitive theories of gender development concerns developmental trajectories in the relative strength or rigidity of gender typing. To examine these trajectories in early childhood, 229 children (African American, Mexican American, and Dominican American) were followed annually from age 3 to 5 years, and gender-stereotypical appearance, dress-up play, toy play, and sex segregation were examined. High gender-typing was found across ethnic groups, and most behaviors increased in rigidity, especially from age 3 to 4 years. In addressing controversy surrounding the stability and structure of gender-typing it was found that from year to year, most behaviors showed moderately stable individual differences. Behaviors were uncorrelated within age but showed more concordance in change across time, suggesting that aspects of gender-typing are multidimensional, but still show coherence. © 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.

Using handgrip strength to screen for diabetes in developing countries.

PubMed

Eckman, Molly; Gigliotti, Christopher; Sutermaster, Staci; Butler, Peter J; Mehta, Khanjan

2016-01-01

Lack of access to healthcare in the developing world has created a need for locally-based primary and pre-primary healthcare systems. Many regions of the world have adopted Community Health Worker (CHW) programmes, but volunteers in these programmes lack the tools and resources to screen for disease. Because of its simplicity of operation, handgrip strength (HGS) measurements have the potential to be an affordable and effective screening tool for conditions that cause muscle weakness in this context. In the study described in this report, translators were used to collect data on age, gender, height, weight, blood pressure, HGS and key demographic data. HGS was significantly lower for diabetics than patients without diabetes. A simple binary logistic model was created that used HGS, age, blood pressure and BMI to predict a patient's probability of having diabetes. This study develops a predictive model for diabetes using HGS and other basic health measurements and shows that HGS-based screening is a viable method of early detection of diabetes.

Associations Among Quadriceps Strength and Rate of Torque Development 6 Weeks Post Anterior Cruciate Ligament Reconstruction and Future Hop and Vertical Jump Performance: A Prospective Cohort Study.

PubMed

Pua, Yong-Hao; Mentiplay, Benjamin F; Clark, Ross A; Ho, Jia-Ying

2017-11-01

Study Design Prospective cohort. Background Quadriceps strength is associated with hop distance and jump height in persons who have undergone anterior cruciate ligament (ACL) reconstruction. However, it is unknown whether the ability to rapidly generate quadriceps torque in the early phase of recovery is associated with future hopping and jumping performance in this population. Objective To evaluate the prospective associations among quadriceps strength and rate of torque development (RTD) and single-leg hop for distance, vertical jump height, vertical ground reaction force (vGRF), and vertical force loading rate during a landing task in persons who have undergone ACL reconstruction. Methods Seventy patients with unilateral ACL reconstruction participated. At 6 weeks post ACL reconstruction, isometric quadriceps strength and RTD were measured using a dynamometer. At 6 months following ACL reconstruction, patients performed the single-leg hop for distance test. Patients also performed the single-leg vertical jump test on a force plate that measured maximum jump height, vGRF, and average loading rate during landing. Results Both quadriceps strength and RTD at 6 weeks post ACL reconstruction were associated with all hopping and jumping measures at 6 months post ACL reconstruction (P≤.04). Single-leg hop distance was associated more closely with quadriceps strength than with quadriceps RTD (P = .05), and vertical jump height and vGRF measures were associated more closely with quadriceps RTD than with quadriceps strength (P = .05 and P<.01, respectively). Both quadriceps measures were associated with loading rate. Conclusion Quadriceps strength and RTD are complementary but distinct predictors of future hopping and jumping performance in persons who have undergone ACL reconstruction. These findings may contribute to improved rehabilitation of patients who are at risk for poor jumping/hopping performance and abnormal knee loading. J Orthop Sports Phys Ther 2017;47(11):845-852. Epub 13 Oct 2017. doi:10.2519/jospt.2017.7133.

Improvements of nano-SiO2 on sludge/fly ash mortar.

PubMed

Lin, D F; Lin, K L; Chang, W C; Luo, H L; Cai, M Q

2008-01-01

Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar.

The effect of curing conditions on the durability of high performance concrete

NASA Astrophysics Data System (ADS)

Bumanis, G.; Bajare, D.

2017-10-01

This study researches compressive strength and durability of the high strength self-compacting concrete (SCC) impacted at early stage by the curing conditions. The mixture compositions of metakaolin containing waste and cenospheres as partial cement replacement (15 wt%) were compared to reference SCC with 100% cement. The specimens prepared in advance were demoulded 24h after casting of the SCC and the specific curing conditions were applied for up to 28 days: standard water curing at 20°C (i); indoor curing at 20°C, RH 60% (ii) and low temperature air curing (2°C) at RH 60% (iii). Results indicate that at early stage (14 days) indoor curing conditions increase compressive strength of the SCC whilst no strength loss has been detected even at a low temperature curing. The further strength gain has been substantially reduced for samples cured indoor and at a low temperature with significant variation observed for long term compressive strength (180 days). The metakaolin containing waste has proved to be an effective partial cement replacement and it has improved strength gain even at a low temperature curing. Meanwhile cenospheres have reduced the SCC strength and with no positive effect on strength observed within the standard term. Freeze-thaw durability and resistance to the chloride penetration have been improved for the SCC cured at low temperature. The SCC with metakaolin containing waste has proved to be the most durable thus demonstrating importance of effective micro filler use.

FAST INdiCATE Trial protocol. Clinical efficacy of functional strength training for upper limb motor recovery early after stroke: neural correlates and prognostic indicators.

PubMed

Pomeroy, Valerie M; Ward, Nick S; Johansen-Berg, Heidi; van Vliet, Paulette; Burridge, Jane; Hunter, Susan M; Lemon, Roger N; Rothwell, John; Weir, Christopher J; Wing, Alan; Walker, Andrew A; Kennedy, Niamh; Barton, Garry; Greenwood, Richard J; McConnachie, Alex

2014-02-01

Functional strength training in addition to conventional physical therapy could enhance upper limb recovery early after stroke more than movement performance therapy plus conventional physical therapy. To determine (a) the relative clinical efficacy of conventional physical therapy combined with functional strength training and conventional physical therapy combined with movement performance therapy for upper limb recovery; (b) the neural correlates of response to conventional physical therapy combined with functional strength training and conventional physical therapy combined with movement performance therapy; (c) whether any one or combination of baseline measures predict motor improvement in response to conventional physical therapy combined with functional strength training or conventional physical therapy combined with movement performance therapy. Randomized, controlled, observer-blind trial. The sample will consist of 288 participants with upper limb paresis resulting from a stroke that occurred within the previous 60 days. All will be allocated to conventional physical therapy combined with functional strength training or conventional physical therapy combined with movement performance therapy. Functional strength training and movement performance therapy will be undertaken for up to 1·5 h/day, five-days/week for six-weeks. Measurements will be undertaken before randomization, six-weeks thereafter, and six-months after stroke. Primary efficacy outcome will be the Action Research Arm Test. Explanatory measurements will include voxel-wise estimates of brain activity during hand movement, brain white matter integrity (fractional anisotropy), and brain-muscle connectivity (e.g. latency of motor evoked potentials). The primary clinical efficacy analysis will compare treatment groups using a multilevel normal linear model adjusting for stratification variables and for which therapist administered the treatment. Effect of conventional physical therapy combined with functional strength training versus conventional physical therapy combined with movement performance therapy will be summarized using the adjusted mean difference and 95% confidence interval. To identify the neural correlates of improvement in both groups, we will investigate associations between change from baseline in clinical outcomes and each explanatory measure. To identify baseline measurements that independently predict motor improvement, we will develop a multiple regression model. © 2013 The Authors. International Journal of Stroke published by John Wiley & Sons Ltd on behalf of World Stroke Organization.

Relationships of muscle strength and bone mineral density in ambulatory children with cerebral palsy.

PubMed

Chen, C-L; Lin, K-C; Wu, C-Y; Ke, J-Y; Wang, C-J; Chen, C-Y

2012-02-01

This work explores the relationships of muscle strength and areal bone mineral density (aBMD) in ambulatory children with cerebral palsy (CP). The knee extensor strength, but not motor function, was related to aBMD. Thus, muscle strength, especially antigravity muscle strength, was more associated with aBMD in these children than motor function. Muscle strength is related to bone density in normal children. However, no studies have examined these relationships in ambulatory children with CP. This work explores the relationships of muscle strength and aBMD in ambulatory children with CP. Forty-eight ambulatory children with spastic CP, aged 5-15 years, were classified into two groups based on Gross Motor Function Classification System levels: I (n = 28) and II (n = 20). Another 31 normal development (ND) children were recruited as the comparison group for the aBMD. Children with CP underwent assessments of growth, lumbar and distal femur aBMD, Gross Motor Function Measure-66 (GMFM-66), and muscle strength of knee extensor and flexor by isokinetic dynamometer. The distal femur aBMD, but not lumbar aBMD, was lower in children with CP than in ND children (p < 0.05). Children with level I had greater knee flexor strength and GMFM-66 scores than those with level II (p < 0.001). However, the knee extensor strength and distal femur and lumbar aBMD did not differ between two groups. Regression analysis revealed the weight and knee extensor strength, but not GMFM-66 scores, were related positively to the distal femur and lumbar aBMD (adjusted r (2) = 0.56-0.65, p < 0.001). These results suggest the muscle strength, especially antigravity muscle strength, were more associated with the bone density of ambulatory children with CP than motor function. The data may allow clinicians for early identifying the ambulatory CP children of potential low bone density.

Contribution of early Alzheimer's Disease-related Pathophysiology to the Development of Acquired epilepsy.

PubMed

Gschwind, Tilo; Lafourcade, Carlos; Gfeller, Tim; Zaichuk, Mariana; Rambousek, Lukas; Knuesel, Irene; Fritschy, Jean-Marc

2018-06-04

Aberrant epileptic activity is detectable at early disease stages in Alzheimer's disease (AD) patients and in AD mouse models. Here, we investigated in young ArcticAβ mice whether AD-like pathology renders neuronal networks more susceptible to development of acquired epilepsy induced by unilateral intrahippocampal injection of kainic acid (IHK). In this temporal lobe epilepsy model, IHK induces a status epilepticus followed after two weeks by spontaneous recurrent seizures (SRS). ArcticAβ mice exhibited more severe status epilepticus and early onset of SRS. This hyperexcitable phenotype was characterized in CA1 neurons by decreased synaptic strength, increased kainic acid-induced LTP, and reduced frequency of spontaneous inhibitory currents. However, no difference in neurodegeneration, neuroinflammation, axonal reorganization or adult neurogenesis was observed in ArcticAβ mice compared to wildtype littermates following IHK-induced epileptogenesis. Neuropeptide Y (NPY) expression was reduced at baseline and its IHK-induced elevation in mossy fibers and granule cells was attenuated. However, although this alteration might underlie premature seizure onset, neutralization of soluble Aβ species by intracerebroventricular Aβ-specific antibody application mitigated the hyperexcitable phenotype of ArcticAβ mice and prevented early SRS onset. Therefore, development of seizures at early stages of AD is mediated primarily by Aβ species causing widespread changes in synaptic function. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Periodic Early Childhood Hearing Screening: The EHDI Perspective

ERIC Educational Resources Information Center

Hoffman, Jeff; Houston, K. Todd; Munoz, Karen F.; Bradham, Tamala S.

2011-01-01

State coordinators of early hearing detection and intervention (EHDI) programs completed a strengths, weaknesses, opportunities, and threats, or SWOT, analysis that examined 12 areas within state EHDI programs. Concerning periodic early childhood hearing screening, 47 coordinators listed 241 items and themes were identified within each SWOT…

The EHDI and Early Intervention Connection

ERIC Educational Resources Information Center

Nelson, Lauri; Bradham, Tamala S.; Houston, K. Todd

2011-01-01

State coordinators of early hearing detection and intervention (EHDI) programs completed a strengths, weaknesses, opportunities, and threats, or SWOT, analysis that examined 12 areas within state EHDI programs. For the early intervention focus question, 48 coordinators listed 273 items, and themes were identified within each SWOT category. A…

Pre-menarcheal physical activity predicts post-menarcheal lean mass and core strength, but not fat mass

PubMed Central

Day, M.A.; Dowthwaite, J.N.; Rosenbaum, P.F.; Roedel, G.G.; Brocker, A.A.; Scerpella, T.A.

2015-01-01

Objectives: Youth exercise is associated with improved body composition, but details regarding timing and persistence are limited. We examined pre- and circum-menarcheal organized physical activity exposure (PA) as a factor in development of early post-menarcheal lean mass, fat mass and muscle strength. Methods: Participants in a longitudinal study of musculoskeletal growth using dual energy X-ray absorptiometry (DXA) were included based on: 1) Whole body DXA scans: 0.5-1.5 years pre-menarche, 0.5-1.5 years post-menarche; 2) PA records for ≥6 months preceding the first DXA (PREPA) and for the inter-DXA interval (CIRCUMPA). Dominant arm grip strength and sit-ups tests coincided with DXA scans; PA, height and maturity were recorded semi-annually. Regressions correlated PA with lean mass/fat mass/strength, accounting for maturity, body size, and baseline values. Results Seventy girls [baseline: 11.8 yrs (sd 1.0), follow-up: 13.9 years (sd 1.0)] demonstrated circum-menarcheal gains of 25-29% for lean and fat mass and 33% for grip strength. PREPA correlated with pre- and post-menarcheal lean mass, sit-ups and pre-menarcheal fat mass (p<0.05), but not grip strength. CIRCUMPA correlated with only post-menarcheal sub-head lean mass (p=0.03). Conclusions: Lean mass and core strength at 1-year post-menarche were more strongly predicted by pre-menarcheal organized PA than by recent circum-menarcheal PA. PMID:26636280

Effects of combination of whey protein intake and rehabilitation on muscle strength and daily movements in patients with hip fracture in the early postoperative period.

PubMed

Niitsu, Masaya; Ichinose, Daisuke; Hirooka, Taku; Mitsutomi, Kazuhiko; Morimoto, Yoshitaka; Sarukawa, Junichiro; Nishikino, Shoichi; Yamauchi, Katsuya; Yamazaki, Kaoru

2016-08-01

Elderly patients can be at risk of protein catabolism and malnutrition in the early postoperative period. Whey protein includes most essential amino acids and stimulates the synthesis of muscle protein. The purpose of this study was to investigate the effect of resistance training in combination with whey protein intake in the early postoperative period. We randomized patients to a whey protein group or a control group. The former group received 32.2 g of whey protein pre- and post-rehabilitation in the early postoperative period for two weeks. Outcomes were knee extension strength on either side by Biodex 4.0, and the ability of transfer, walking, toilet use and stair use by the Barthel Index (BI). We performed initial and final assessments in the second and tenth rehabilitation sessions. A total of 38 patients were recruited: 20 in the whey protein group and 18 in the control group. Participants in the whey protein group showed significantly greater improvement in knee extension strength in the operated limb compared with the control group (F = 6.11, P = 0.02). The non-operated limb also showed a similar tendency (F = 3.51, P = 0.07). The abilities of transfer, walking and toilet use showed greater improvements in the whey protein group than in the control group by BI (P < 0.05). The combination of whey protein intake and rehabilitation for two weeks in the early postoperative period has a beneficial effect on knee extension strength in both lower limbs and BI (transfer, walking and toilet use) scores in patients with hip fracture. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Total Lightning Characteristics with Respect to Radar-Derived Mesocyclone Strength

NASA Technical Reports Server (NTRS)

Stough, Sarah M.; Carey, Lawrence D.; Schultz, Christopher J.

2015-01-01

Recent work investigating the microphysical and kinematic relationship between a storm's updraft, its total lightning production, and manifestations of severe weather has resulted in development of tools for improved nowcasting of storm intensity. The total lightning jump algorithm, which identifies rapid increases in total lightning flash rate that often precede severe events, has shown particular potential to benefit warning operations. Maximizing this capability of total lightning and its operational implementation via the lightning jump may best be done through its fusion with radar and radar-derived intensity metrics. Identification of a mesocyclone, or quasi-steady rotating updraft, in Doppler velocity is the predominant radar-inferred early indicator of severe potential in a convective storm. Fused lightning-radar tools that capitalize on the most robust intensity indicators would allow enhanced situational awareness for increased warning confidence. A foundational step toward such tools comes from a better understanding of the updraft-centric relationship between intensification of total lightning production and mesocyclone development and strength. The work presented here utilizes a sample of supercell case studies representing a spectrum of severity. These storms are analyzed with respect to total lightning flash rate and the lightning jump alongside mesocyclone strength derived objectively from the National Severe Storms Laboratory (NSSL) Mesocyclone Detection Algorithm (MDA) and maximum azimuthal shear through a layer. Early results indicate that temporal similarities exist in the trends between total lightning flash rate and low- to mid-level rotation in supercells. Other characteristics such as polarimetric signatures of rotation, flash size, and cloud-to-ground flash ratio are explored for added insight into the significance of these trends with respect to the updraft and related processes of severe weather production.

Proactive Parent Engagement in Public Schools: Using a Brief Strengths and Needs Assessment in a Multiple-Gating Risk Management Strategy

ERIC Educational Resources Information Center

Moore, Kevin J.; Garbacz, S. Andrew; Gau, Jeff M.; Dishion, Thomas J.; Brown, Kimbree L.; Stormshak, Elizabeth A.; Seeley, John R.

2016-01-01

This study examined the viability of a brief, parent-reported strengths and needs assessment as the first step in a multiple-gating approach to proactive positive behavior support for families. The "Positive Family Support--Strengths and Needs Assessment" (PFS-SaNA) was designed to collaboratively engage parents early in the school year…

Sports Specialization, Part II

PubMed Central

Myer, Gregory D.; Jayanthi, Neeru; DiFiori, John P.; Faigenbaum, Avery D.; Kiefer, Adam W.; Logerstedt, David; Micheli, Lyle J.

2016-01-01

Context: Many coaches, parents, and children believe that the best way to develop elite athletes is for them to participate in only 1 sport from an early age and to play it year-round. However, emerging evidence to the contrary indicates that efforts to specialize in 1 sport may reduce opportunities for all children to participate in a diverse year-round sports season and can lead to lost development of lifetime sports skills. Early sports specialization may also reduce motor skill development and ongoing participation in games and sports as a lifestyle choice. The purpose of this review is to employ the current literature to provide evidence-based alternative strategies that may help to optimize opportunities for all aspiring young athletes to maximize their health, fitness, and sports performance. Evidence Acquisition: Nonsystematic review with critical appraisal of existing literature. Study Design: Clinical review. Level of Evidence: Level 4. Conclusion: Based on the current evidence, parents and educators should help provide opportunities for free unstructured play to improve motor skill development and youth should be encouraged to participate in a variety of sports during their growing years to influence the development of diverse motor skills. For those children who do choose to specialize in a single sport, periods of intense training and specialized sport activities should be closely monitored for indicators of burnout, overuse injury, or potential decrements in performance due to overtraining. Last, the evidence indicates that all youth should be involved in periodized strength and conditioning (eg, integrative neuromuscular training) to help them prepare for the demands of competitive sport participation, and youth who specialize in a single sport should plan periods of isolated and focused integrative neuromuscular training to enhance diverse motor skill development and reduce injury risk factors. Strength of Recommendation Taxonomy (SORT): B. PMID:26517937

Multivoxel proton magnetic resonance spectroscopy in facioscapulohumeral muscular dystrophy.

PubMed

Leung, Doris G; Wang, Xin; Barker, Peter B; Carrino, John A; Wagner, Kathryn R

2018-06-01

Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary disorder that causes progressive muscle wasting. This study evaluates the use of proton magnetic resonance spectroscopy ( 1 H MRS) as a biomarker of muscle strength and function in FSHD. Thirty-six individuals with FSHD and 15 healthy controls underwent multivoxel 1 H MRS of a cross-section of the mid-thigh. Concentrations of creatine, intramyocellular and extramyocellular lipids, and trimethylamine (TMA)-containing compounds in skeletal muscle were calculated. Metabolite concentrations for individuals with FSHD were compared with those of controls. The relationship between metabolite concentrations and muscle strength was also examined. The TMA/creatine (Cr) ratio in individuals with FSHD was reduced compared with controls. The TMA/Cr ratio in the hamstrings also showed a moderate linear correlation with muscle strength. 1 H MRS offers a potential method of detecting early muscle pathology in FSHD prior to the development of fat infiltration. Muscle Nerve 57: 958-963, 2018. © 2017 Wiley Periodicals, Inc.

Early strength prediction of concrete based on accelerated curing methods : final report.

DOT National Transportation Integrated Search

1995-12-01

Concrete mix designs and components may currently be changed during the course of a project. The possible negative effects of such changes on concrete strength, are not determined under the current plant control/project control process. Also, the cur...

Study protocol for a randomized controlled trial: tongue strengthening exercises in head and neck cancer patients, does exercise load matter?

PubMed

Van Nuffelen, Gwen; Van den Steen, Leen; Vanderveken, Olivier; Specenier, Pol; Van Laer, Carl; Van Rompaey, Diane; Guns, Cindy; Mariën, Steven; Peeters, Marc; Van de Heyning, Paul; Vanderwegen, Jan; De Bodt, Marc

2015-09-04

Reduced tongue strength is an important factor contributing to early and late dysphagia in head and neck cancer patients previously treated with chemoradiotherapy. The evidence is growing that tongue strengthening exercises can improve tongue strength and swallowing function in both healthy and dysphagic subjects. However, little is known about the impact of specific features of an exercise protocol for tongue strength on the actual outcome (strength or swallowing function). Previous research originating in the fields of sports medicine and physical rehabilitation shows that the degree of exercise load is an influential factor for increasing muscle strength in the limb skeletal muscles. Since the tongue is considered a muscular hydrostat, it remains to be proven whether the same concepts will apply. This ongoing randomized controlled trial in chemoradiotherapy-treated patients with head and neck cancer investigates the effect of three tongue strengthening exercise protocols, with different degrees of exercise load, on tongue strength and swallowing. At enrollment, 51 patients whose dysphagia is primarily related to reduced tongue strength are randomly assigned to a training schedule of 60, 80, or 100% of their maximal tongue strength. Patients are treated three times a week for 8 weeks, executing 120 repetitions of the assigned exercise once per training day. Exercise load is progressively adjusted every 2 weeks. Patients are evaluated before, during and after treatment by means of tongue strength measurements, fiber-optic endoscopic evaluation of swallowing and quality-of-life questionnaires. This randomized controlled trial is the first to systematically investigate the effect of different exercise loads in tongue strengthening exercise protocols. The results will allow the development of more efficacious protocols. Current Controlled Trials ISRCTN14447678.

Motor development in individuals with congenital adrenal hyperplasia: strength, targeting, and fine motor skill.

PubMed

Collaer, Marcia L; Brook, Charles G D; Conway, Gerard S; Hindmarsh, Peter C; Hines, Melissa

2009-02-01

This study investigated early androgen influence on the development of human motor and visuomotor characteristics. Participants, ages 12-45 years, were individuals with congenital adrenal hyperplasia (CAH), a disorder causing increased adrenal androgen production before birth (40 females, 29 males) and their unaffected relatives (29 females, 30 males). We investigated grip strength and visuomotor targeting tasks on which males generally outperform females, and fine motor pegboard tasks on which females generally outperform males. Physical characteristics (height and weight) were measured to explore whether body parameters could explain differences in motor skills. Females with CAH were stronger and showed better targeting than unaffected females and showed reduced fine visuomotor skill on one pegboard measure, with no difference on the other. Males with CAH were weaker than unaffected males in grip strength but did not differ on the targeting or pegboard measures. Correction for body size could not explain the findings for females, but suggests that the reduced strength of males with CAH may relate to their smaller stature. Further, the targeting advantage in females with CAH persisted following adjustment for their greater strength. Results in females support the hypothesis that androgen may masculinize, or promote, certain motor characteristics at which males excel, and contribute to defeminization of certain fine motor characteristics at which females excel. Thus, these data suggest that organizational effects of androgens on behavior during prenatal life may extend to motor characteristics and may contribute to general sex differences in motor-related behaviors; however, alternative explanations based on activational influences of androgen or altered experiential factors cannot be excluded without further study.

Reliability and Structural Validity of The Teacher Rating Scales of Early Academic Competence

ERIC Educational Resources Information Center

Reid, Erin E.; Diperna, James C.; Missall, Kristen; Volpe, Robert J.

2014-01-01

Currently, there are few strengths-based preschool rating scales that sample a wide array of behaviors believed to be essential for early academic success. The purpose of this study was to assess the factor structure of a new measure of early academic competence for at-risk preschool populations. The Teacher Rating Scales of Early Academic…

Evolution of Mat Strength from the Paleoarchean to the Modern: A Record of Evolving Microbial Communities?

NASA Astrophysics Data System (ADS)

Tice, M.; Pope, M.; Thornton, D.

2011-12-01

Fossil microbial mats, i.e. surface-attached communities of benthic microorganisms, form the most extensive record of life on Earth. Qualitatively changing mat morphologies from 3.43-0.56-billion-years-ago may reflect the evolution of microorganism communities or changing environmental conditions. However, mat morphogenesis is not well understood or easily quantifiable, making interpretation of the mat record difficult. We show that microbial mat cohesion increased from ~1 Pa to ~13 Pa at 2.7-billion-years-ago (Ga), and has remained high for most of the rest of Earth history. This initial increase may represent an early increase in the productivity of mat communities, a change in the composition of extracellular polymeric substances (EPS) produced by mat-formers, or a change in the composition of seawater affecting EPS strength. The appearance of early high-strength communities was coincident with the appearance of voids representing gas bubbles in the apices of conical stromatolites; together, these changes may record the emergence of productive mat communities dominated by oxygenic cyanobacteria. The earliest high-strength communities, like early bubble-forming conical stromatolites, grew in low-energy environments. The appearance of high-strength communities in shallow-water environments starting 2.63-2.52 Ga coincided with the appearance of the first barrier reef complexes. We hypothesize that the first oxygenic cyanobacteria were most competitive with anoxygenic phototrophs in diffusion-limited environments. As the cyanobacteria became more proficient at oxygenic photosynthesis, they eventually outcompeted anoxygenic phototrophs in higher-energy environments. Competition with higher strength seaweed and grazing by metazoans has displaced mat communities from essentially all modern high-energy niches.

Down syndrome: Cognitive and behavioral functioning across the lifespan.

PubMed

Grieco, Julie; Pulsifer, Margaret; Seligsohn, Karen; Skotko, Brian; Schwartz, Alison

2015-06-01

Individuals with Down syndrome (DS) commonly possess unique neurocognitive and neurobehavioral profiles that emerge within specific developmental periods. These profiles are distinct relative to others with similar intellectual disability (ID) and reflect underlying neuroanatomic findings, providing support for a distinctive phenotypic profile. This review updates what is known about the cognitive and behavioral phenotypes associated with DS across the lifespan. In early childhood, mild deviations from neurotypically developing trajectories emerge. By school-age, delays become pronounced. Nonverbal skills remain on trajectory for mental age, whereas verbal deficits emerge and persist. Nonverbal learning and memory are strengths relative to verbal skills. Expressive language is delayed relative to comprehension. Aspects of language skills continue to develop throughout adolescence, although language skills remain compromised in adulthood. Deficits in attention/executive functions are present in childhood and become more pronounced with age. Characteristic features associated with DS (cheerful, social nature) are personality assets. Children are at a lower risk for psychopathology compared to other children with ID; families report lower levels of stress and a more positive outlook. In youth, externalizing behaviors may be problematic, whereas a shift toward internalizing behaviors emerges with maturity. Changes in emotional/behavioral functioning in adulthood are typically associated with neurodegeneration and individuals with DS are higher risk for dementia of the Alzheimer's type. Individuals with DS possess many unique strengths and weaknesses that should be appreciated as they develop across the lifespan. Awareness of this profile by professionals and caregivers can promote early detection and support cognitive and behavioral development. © 2015 Wiley Periodicals, Inc.

Handgrip Strength and Ideal Cardiovascular Health among Colombian Children and Adolescents.

PubMed

Ramírez-Vélez, Robinson; Tordecilla-Sanders, Alejandra; Correa-Bautista, Jorge Enrique; Peterson, Mark D; Garcia-Hermoso, Antonio

2016-12-01

To evaluate the association between handgrip strength and ideal cardiovascular health (CVH) in Colombian children and adolescents. During the 2014-2015 school years, we examined a cross-sectional component of the FUPRECOL (Association for Muscular Strength with Early Manifestation of Cardiovascular Disease Risk Factors among Colombian Children and Adolescents) study. Participants included 1199 (n = 627 boys) youths from Bogota (Colombia). Handgrip strength was measured with a standard adjustable hand held dynamometer and expressed relative to body mass (handgrip/body mass) and as absolute values in kilograms. Ideal CVH, as defined by the American Heart Association, was determined as meeting ideal levels of the following components: 4 behaviors (smoking status, body mass index, cardiorespiratory fitness, and diet) and 3 factors (total cholesterol, blood pressure, and glucose). Higher levels of handgrip strength (both absolute and relative values) were associated with a higher frequency of ideal CVH metrics in both sexes (P for trend ≤ .001). Also, higher levels of handgrip strength were associated with a greater number of ideal health behaviors (P for trend < .001 in both boys and girls), and with a higher number of ideal health factors in boys (P for trend < .001). Finally, levels of handgrip strength were similar between ideal versus nonideal glucose or total cholesterol groups in girls. Handgrip strength was strongly associated with ideal CVH in Colombian children and adolescents, and thus supports the relevance of early targeted interventions to promote strength adaptation and preservation as part of primordial prevention. Copyright © 2016 Elsevier Inc. All rights reserved.

The Trainability of Adolescent Soccer Players to Brief Periodized Complex Training.

PubMed

Chatzinikolaou, Athanasios; Michaloglou, Konstantinos; Avloniti, Alexandra; Leontsini, Diamanda; Deli, Chariklia K; Vlachopoulos, Dimitris; Gracia-Marco, Luis; Arsenis, Sotirios; Athanailidis, Ioannis; Draganidis, Dimitrios; Jamurtas, Athanasios Z; Williams, Craig A; Fatouros, Ioannis G

2018-05-01

To investigate the effect of a complex, short-term strength/power training protocol on performance and body composition of elite early adolescent soccer players. Twenty-two players (14-15 y) were randomly assigned to (1) an experimental group (N = 12; participated in a 5-wk training protocol with traditional multijoint power resistance exercises, Olympic-style lifts, plyometric drills, and speed work; 4 times per week) or (2) a control group (N = 10). Strength and power performance (jumping, speed, change of direction, repeated sprint ability, endurance, isokinetic strength of knee flexors and extensors, maximal strength in various lifts, and speed-endurance) were evaluated pretraining and posttraining. Cessation of training for 5 weeks in the control group induced a marked performance deterioration (∼5%-20%). Training not only prevented strength performance deterioration but also increased it (∼2%-30%). Endurance and repeated sprint ability declined to a smaller extent in experimental group compared with control group (15% vs 7.5%). Isometric strength and body composition remained unaltered in both groups. Results demonstrate that (1) young players exhibit a high level of trainability of their strength/power performance (but not endurance) in response to a short-term complex training protocol during early adolescence, (2) Olympic-style lifts are characterized by increased safety in this age group and appear to be highly effective, (3) lifts incorporating a hip thrust result in increased strength of both knee extensors and flexors, (4) cessation of training for only 5 weeks results in marked deterioration of strength/power and endurance performance, and (5) improvement of strength/power performance may be related to neural-based adaptation as body composition remained unaffected.

Construction, Instrumentation, and Testing of Fast-Setting Hydraulic Cement Concrete in Palmdale, California

DOT National Transportation Integrated Search

2000-08-01

To minimize the lane closure time for construction, Caltrans is exploring the use of fast-setting hydraulic cement concrete (FSHCC). The principal property of the FSHCC is its high early strength gain. This accelerated strength gain would increase th...

Feature Statistics Modulate the Activation of Meaning During Spoken Word Processing.

PubMed

Devereux, Barry J; Taylor, Kirsten I; Randall, Billi; Geertzen, Jeroen; Tyler, Lorraine K

2016-03-01

Understanding spoken words involves a rapid mapping from speech to conceptual representations. One distributed feature-based conceptual account assumes that the statistical characteristics of concepts' features--the number of concepts they occur in (distinctiveness/sharedness) and likelihood of co-occurrence (correlational strength)--determine conceptual activation. To test these claims, we investigated the role of distinctiveness/sharedness and correlational strength in speech-to-meaning mapping, using a lexical decision task and computational simulations. Responses were faster for concepts with higher sharedness, suggesting that shared features are facilitatory in tasks like lexical decision that require access to them. Correlational strength facilitated responses for slower participants, suggesting a time-sensitive co-occurrence-driven settling mechanism. The computational simulation showed similar effects, with early effects of shared features and later effects of correlational strength. These results support a general-to-specific account of conceptual processing, whereby early activation of shared features is followed by the gradual emergence of a specific target representation. Copyright © 2015 The Authors. Cognitive Science published by Cognitive Science Society, Inc.

F2 layer characteristics and electrojet strength over an equatorial station

NASA Astrophysics Data System (ADS)

Adebesin, B. O.; Adeniyi, J. O.; Adimula, I. A.; Reinisch, B. W.; Yumoto, K.

2013-09-01

The data presented in this work describes the diurnal and seasonal variation in hmF2, NmF2, and the electrojet current strength over an African equatorial station during a period of low solar activity. The F2 region horizontal magnetic element H revealed that the Solar quiet Sq(H) daily variation rises from early morning period to maximum around local noon and falls to lower values towards evening. The F2 ionospheric current responsible for the magnetic field variations is inferred to build up at the early morning hours, attaining maximum strength around 1200 LT. The Sq variation across the entire months was higher during the daytime than nighttime. This is ascribed to the variability of the ionospheric parameters like conductivity and winds structure in this region. Seasonal daytime electrojet (EEJ) current strength for June solstice, March and September equinoxes, respectively had peak values ranging within 27-35 nT (at 1400 LT) , 30-40 nT (at 1200 LT) and 35-45 nT (at 1500 LT). The different peak periods of the EEJ strength were attributed to the combined effects of the peak electron density and electric field. Lastly, the EEJ strength was observed to be higher during the equinoxes than the solstice period.

Effect of surface roughness of hydroxyapatite-coated titanium on the bone-implant interface shear strength.

PubMed

Hayashi, K; Inadome, T; Tsumura, H; Nakashima, Y; Sugioka, Y

1994-11-01

We have investigated the bone-implant interface shear strength of hydroxyapatite (HA)-coated Ti-6Al-4V (HA-coating A) (roughness average, Ra = 3.4 +/- 0.5 microns) and HA-coated Ti-6Al-4V with a rougher surface (HA-coating B) (Ra = 8.4 +/- 1.8 microns). There was no significant difference between HA-coating A and HA-coating B implants with respect to the bone-implant interface shear strength as determined in push-out tests using the transcortical model in adult dogs. The bone-implant interface shear strength of bead-coated porous Ti-6Al-4V was significantly greater than that of both HA-coating A and HA-coating B implants. The failure site, as determined by scanning electron microscopy, was the coating-substrate interface, not the coating-bone interface. This indicates a need to protect the HA coating from the direct shear forces. HA coating enhances early bone growth into the porous surface of the implant. Long-term fixation should depend on bone anchoring to this porous surface. Hydroxyapatite coatings must be developed which do not obstruct the pores of the surface of the implant.

A cross-sectional pilot study of the Scottish early development instrument: a tool for addressing inequality

PubMed Central

2013-01-01

Background Early childhood is recognised as a key developmental phase with implications for social, academic, health and wellbeing outcomes in later childhood and indeed throughout the adult lifespan. Community level data on inequalities in early child development are therefore required to establish the impact of government early years’ policies and programmes on children’s strengths and vulnerabilities at local and national level. This would allow local leaders to target tailored interventions according to community needs to improve children’s readiness for the transition to school. The challenge is collecting valid data on sufficient samples of children entering school to derive robust inferences about each local birth cohort’s developmental status. This information needs to be presented in a way that allows community stakeholders to understand the results, expediting the improvement of preschool programming to improve future cohorts’ development in the early years. The aim of the study was to carry out a pilot to test the feasibility and ease of use in Scotland of the 104-item teacher-administered Early Development Instrument, an internationally validated measure of children’s global development at school entry developed in Canada. Methods Phase 1 was piloted in an education district with 14 Primary 1 teachers assessing a cohort of 154 children, following which the instrument was adapted for the Scottish context (Scottish Early Development Instrument: SEDI). Phase 2 was then carried out using the SEDI. Data were analysed from a larger sample of 1090 participants, comprising all Primary 1 children within this school district, evaluated by 68 teachers. Results The SEDI displayed adequate psychometric and discriminatory properties and is appropriate for use across Scotland without any further modifications. Children in the lowest socioeconomic status quintiles were 2–3 times more likely than children in the most affluent quintile to score low in at least one developmental domain. Even in the most affluent quintile though, 17% of children were ‘developmentally vulnerable’, suggesting that those in need cannot be identified by socioeconomic status alone. Conclusions The SEDI offers a feasible means of providing communities with a holistic overview of school readiness for targeting early years’ interventions. PMID:24341526

Parent-adolescent relationships and its association to adolescents' self-esteem.

PubMed

Yaacob, Mohd Jamil Bin

2006-01-01

Psychoanalysts believed that early mother-child relationships form the prototype of all future relationships and the outcome of adolescents development depends on their ego-strength. Object relations theory believed that intrapsychic process mediates interpersonal interaction to develop a sense of secure self and adolescents must relinquish the internalized other in order to develop a more mature sense of self. Social-relation theory believed that mothers and fathers provide different socialization experiences. Self-esteem depends on the functioning of the whole family in which adolescent is intimately related to the dyadic relationship in a family. There is an association between interparental conflict and adolescent's self-esteem and problem behaviour.

A basal magma ocean dynamo to explain the early lunar magnetic field

NASA Astrophysics Data System (ADS)

Scheinberg, Aaron L.; Soderlund, Krista M.; Elkins-Tanton, Linda T.

2018-06-01

The source of the ancient lunar magnetic field is an unsolved problem in the Moon's evolution. Theoretical work invoking a core dynamo has been unable to explain the magnitude of the observed field, falling instead one to two orders of magnitude below it. Since surface magnetic field strength is highly sensitive to the depth and size of the dynamo region, we instead hypothesize that the early lunar dynamo was driven by convection in a basal magma ocean formed from the final stages of an early lunar magma ocean; this material is expected to be dense, radioactive, and metalliferous. Here we use numerical convection models to predict the longevity and heat flow of such a basal magma ocean and use scaling laws to estimate the resulting magnetic field strength. We show that, if sufficiently electrically conducting, a magma ocean could have produced an early dynamo with surface fields consistent with the paleomagnetic observations.

[Compressive and bend strength of experimental admixed high copper alloys].

PubMed

Sourai, P; Paximada, H; Lagouvardos, P; Douvitsas, G

1988-01-01

Mixed alloys for dental amalgams have been used mainly in the form of admixed alloys, where eutectic spheres are blend with conventional flakes. In the present study the compressive strength, bend strength and microstructure of two high-copper alloys (Tytin, Ana-2000) is compared with three experimental alloys prepared of the two high copper by mixing them in proportions of 3:1, 1:1 and 1:3 by weight. The results revealed that experimental alloys inherited high early and final strength values without any significant change in their microstructure.

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 language with an adoptive language. Copyright © 2015 Elsevier Inc. All rights reserved.

Early Adolescent Perceptions of Neighborhood: Strengths, Structural Disadvantage, and Relations to Outcomes

ERIC Educational Resources Information Center

Witherspoon, Dawn P.; Hughes, Diane L.

2014-01-01

Considerable evidence shows the detriments of neighborhood social disorganization for urban youth. Researchers have focused less on potential neighborhood strengths or on the interplay of neighborhood perceptions and objective neighborhood characteristics. The authors examined the presence and perception of positive and negative neighborhood…

Implementation of Maturity for Concrete Strength Measurement and Pay : Tech Summary

DOT National Transportation Integrated Search

2017-10-01

Using the maturity to determine concrete strength has been done for more than four decades. The concept was originally conceived in the late 1940s and early 1950s. More and more state and municipal DOTs are implementing its use every year, with some ...

Impacts of Early Summer Eurasian Snow Cover Change on Atmospheric Circulation in Northern Mid-Latitudes

NASA Astrophysics Data System (ADS)

Nozawa, T.

2016-12-01

Recently, Japan Aerospace Exploration Agency (JAXA) has developed a new long-term snow cover extent (SCE) product using Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) data spanning from 1980's to date. This new product (JAXA/SCE) has higher spatial resolution and smaller commission error compared with traditional SCE dataset of National Oceanic and Atmospheric Administration (NOAA/SCE). Continuity of the algorithm is another strong point in JAXA/SCE. According to the new JAXA/SCE dataset, the Eurasian SCE has been significantly retreating since 1980's, especially in late spring and early summer. Here, we investigate impacts of early summer Eurasian snow cover change on atmospheric circulation in Northern mid-latitudes, especially over the East Asia, using the new JAXA/SCE dataset and a few reanalysis data. We will present analyzed results on relationships between early summer SCE anomaly over the Eurasia and changes in atmospheric circulations such as upper level zonal jets (changes in strength, positions, etc.) over the East Asia.

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.

The Effect of Curing Temperature on the Properties of Cement Pastes Modified with TiO2 Nanoparticles

PubMed Central

Pimenta Teixeira, Karine; Perdigão Rocha, Isadora; De Sá Carneiro, Leticia; Flores, Jessica; Dauer, Edward A.; Ghahremaninezhad, Ali

2016-01-01

This paper investigates the effect of curing temperature on the hydration, microstructure, compressive strength, and transport of cement pastes modified with TiO2 nanoparticles. These characteristics of cement pastes were studied using non-evaporable water content measurement, X-ray diffraction (XRD), compressive strength test, electrical resistivity and porosity measurements, and scanning electron microscopy (SEM). It was shown that temperature enhanced the early hydration. The cement pastes cured at elevated temperatures generally showed an increase in compressive strength at an early age compared to the cement paste cured at room temperature, but the strength gain decreased at later ages. The electrical resistivity of the cement pastes cured at elevated temperatures was found to decrease more noticeably at late ages compared to that of the room temperature cured cement paste. SEM examination indicated that hydration product was more uniformly distributed in the microstructure of the cement paste cured at room temperature compared to the cement pastes cured at elevated temperatures. It was observed that high temperature curing decreased the compressive strength and electrical resistivity of the cement pastes at late ages in a more pronounced manner when higher levels of TiO2 nanoparticles were added. PMID:28774073

Patterns of Spontaneous Local Network Activity in Developing Cerebral Cortex: Relationship to Adult Cognitive Function.

PubMed

Peinado, Alejandro; Abrams, Charles K

2015-01-01

Detecting neurodevelopμental disorders of cognition at the earliest possible stages could assist in understanding them mechanistically and ultimately in treating them. Finding early physiological predictors that could be visualized with functional neuroimaging would represent an important advance in this regard. We hypothesized that one potential source of physiological predictors is the spontaneous local network activity prominent during specific periods in development. To test this we used calcium imaging in brain slices and analyzed variations in the frequency and intensity of this early activity in one area, the entorhinal cortex (EC), in order to correlate early activity with level of cognitive function later in life. We focused on EC because of its known role in different types of cognitive processes and because it is an area where spontaneous activity is prominent during early postnatal development in rodent models of cortical development. Using rat strains (Long-Evans, Wistar, Sprague-Dawley and Brattleboro) known to differ in cognitive performance in adulthood we asked whether neonatal animals exhibit corresponding strain-related differences in EC spontaneous activity. Our results show significant differences in this activity between strains: compared to a high cognitive-performing strain, we consistently found an increase in frequency and decrease in intensity in neonates from three lower performing strains. Activity was most different in one strain considered a model of schizophrenia-like psychopathology. While we cannot necessarily infer a causal relationship between early activity and adult cognition our findings suggest that the pattern of spontaneous activity in development could be an early predictor of a developmental trajectory advancing toward sub-optimal cognitive performance in adulthood. Our results further suggest that the strength of dopaminergic signaling, by setting the balance between excitation and inhibition, is a potential underlying mechanism that could explain the observed differences in early spontaneous activity patterns.

Whole-Body Vibration Improves Early Rate of Torque Development in Individuals With Anterior Cruciate Ligament Reconstruction.

PubMed

Pamukoff, Derek N; Pietrosimone, Brian; Ryan, Eric D; Lee, Dustin R; Brown, Lee E; Blackburn, J Troy

2017-11-01

Pamukoff, DN, Pietrosimone, B, Ryan, ED, Lee, DR, Brown, LE, and Blackburn, JT. Whole body vibration improves early rate of torque development in individuals with anterior cruciate ligament reconstruction. J Strength Cond Res 31(11): 2992-3000, 2017-The purpose of this study was to compare the effect of whole-body vibration (WBV) and local muscle vibration (LMV) on early and late quadriceps rate of torque development (RTD), and electromechanical delay (EMD) in individuals with anterior cruciate ligament reconstruction (ACLR). Twenty individuals with ACLR were recruited for this study. Participants performed isometric squats while being exposed to WBV, LMV, or no vibration (control) in a randomized order during separate visits. Early and late quadriceps RTD and EMD were assessed during a maximal voluntary isometric knee extension before and immediately after WBV, LMV, or control. There was a significant condition by time interaction for early RTD (p = 0.045) but not for late RTD (p = 0.11) or EMD of the vastus medialis (p = 0.15), vastus lateralis (p = 0.17), or rectus femoris (p = 0.39). Post hoc analyses indicated a significant increase in early RTD after WBV (+5.59 N·m·s·kg; 95% confidence interval, 1.47-12.72; p = 0.007). No differences were observed in the LMV or control conditions, and no difference was observed between conditions at posttest. The ability to rapidly produce knee extension torque is essential to physical function, and WBV may be appropriate to aid in the restoration of RTD after ACLR.

Low Clouds and Cosmic Rays: Possible Reasons for Correlation Changes

NASA Astrophysics Data System (ADS)

Veretenenko, S. V.; Ogurtsov, M. G.

2015-03-01

In this work we investigated the nature of correlations between low cloud cover anomalies (LCA) and galactic cosmic ray (GCR) variations detected on the decadal time scale, as well as possible reasons for the violation of these correlations in the early 2000s. It was shown that the link between cloud cover at middle latitudes and GCR fluxes is not direct, but it is realized through GCR influence on the development of extratropical baric systems (cyclones and troughs) which form cloud field. As the sign of GCR effects on the troposphere dynamics seems to depend on the strength of the stratospheric polar vortex, a possible reason for the violation of a positive correlation between LCA and GCR fluxes in the early 2000s may be the change of the vortex state which resulted in the reversal of GCR effects on extratropical cyclone development.

Cognitive development: no stages please--we're British.

PubMed

Goswami, U

2001-02-01

British cognitive developmental psychology is characterized by its interest in philosophical questions, its preference for linking basic research to applied issues in education and cognitive disorders, and its willingness to learn both methodologically and theoretically from work in animal psychology and in physiology more generally. It has also been influenced profoundly by Jean Piaget's cognitive stage theory although in general British work has focused on demonstrating early strengths, rather than early deficits, in infant and child cognition. Following an overview of British work that encompasses past and present interests, issues and challenges for the future are highlighted. While the perspectives of the founding members of the British Psychological Society (BPS), as outlined by Edgell (1947), are still apparent in British research in cognitive developmental psychology today, it is argued that future cognitive work must become even more interdisciplinary and that the symbiotic relationship between research in adult cognition and in cognitive development needs greater recognition.

Cognitive development: No stages please - we're British.

PubMed

Goswami, Usha

2001-02-01

British cognitive developmental psychology is characterized by its interest in philosophical questions, its preference for linking basic research to applied issues in education and cognitive disorders, and its willingness to learn both methodologically and theoretically from work in animal psychology and in physiology more generally. It has also been influenced profoundly by Jean Piaget's cognitive stage theory although in general British work has focused on demonstrating early strengths, rather than early deficits, in infant and child cognition. Following an overview of British work that encompasses past and present interests, issues and challenges for the future are highlighted. While the perspectives of the founding members of the British Psychological Society (BPS), as outlined by Edgell (1947), are still apparent in British research in cognitive developmental psychology today, it is argued that future cognitive work must become even more interdisciplinary and that the symbiotic relationship between research in adult cognition and in cognitive development needs greater recognition.

Leveraging paraprofessionals and family strengths to improve coverage and penetration of nutrition and early child development services.

PubMed

Tomlinson, Mark; Rahman, Atif; Sanders, David; Maselko, Joanna; Rotheram-Borus, Mary Jane

2014-01-01

Children need to be protected in intergenerational networks, with parents who have positive mood, resources to feed their children, and skills to promote early childhood development (ECD). Globally, more than 200 million children are raised annually without these resources. This article reviews the potential contributions of increasing coverage and penetration of services for these children, challenges to achieving penetration of services in high-risk families, opportunities created by bundling multiple services within one provider, potential leveraging of paraprofessionals to deliver care, and mobilizing communities to support children in households at high risk for negative outcomes. We end with a number of suggestions for how to ensure the equitable scale-up of integrated ECD and nutrition services that take into account current global priorities, as well as coverage and penetration of services. © 2013 New York Academy of Sciences.

Emerging Cardiac Imaging Modalities for the Early Detection of Cardiotoxicity Due to Anticancer Therapies.

PubMed

López-Fernández, Teresa; Thavendiranathan, Paaladinesh

2017-06-01

The undeniable advances in the field of oncology have finally led to a decrease in overall cancer-related mortality. However, this population of long-term cancer survivors is now facing a shift toward a substantial increase in cardiovascular morbidity and mortality. Because the development of overt cardiotoxicity can be associated with poor outcomes, preclinical identification of cardiac toxicity is important. This will promote early instauration of treatments to prevent overt heart dysfunction and allow oncologists to continue cancer therapy in an uninterrupted manner. Surveillance strategies for the early detection of cardiac injury include cardiac imaging and biomarkers during treatment. In this review, we outline existing cardiac imaging modalities to detect myocardial changes in patients undergoing cancer treatment and in survivors, and their strengths and limitations. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Assessment of Preschool Early Literacy Skills: Linking Children's Educational Needs with Empirically Supported Instructional Activities.

PubMed

Lonigan, Christopher J; Allan, Nicholas P; Lerner, Matthew D

2011-05-01

The importance of the preschool period for becoming a skilled reader is highlighted by a significant body of evidence that preschool children's development in the areas of oral language, phonological awareness, and print knowledge is predictive of how well they will learn to read once they are exposed to formal reading instruction in elementary school. Although there are now a number of empirically supported instructional activities for helping children who are at -risk of later reading difficulties acquire these early literacy skills, limitations in instructional time and opportunities in most preschool settings requires the use of valid assessment procedures to ensure that instructional resources are utilized efficiently. In this paper, we discuss the degree to which informal, diagnostic, screening, and progress-monitoring assessments of preschool early literacy skills can inform instructional decisions by considering the strengths and weaknesses of each approach to assessment.

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.

Achieving effective hearing aid fitting within one month after identification of childhood permanent hearing impairment.

PubMed

Bastanza, G; Gallus, R; De Carlini, M; Picciotti, P M; Muzzi, E; Ciciriello, E; Orzan, E; Conti, G

2016-02-01

Diagnosis of child permanent hearing impairment (PHI) can be made with extreme timeliness compared to the past thanks to improvements in PHI identification through newborn hearing screening programmes. It now becomes essential to provide an effective amplification as quickly as possible in order to restore auditory function and favour speech and language development. The early fitting of hearing aids and possible later cochlear implantation indeed prompts the development of central auditory pathways, connections with secondary sensory brain areas, as well as with motor and articulatory cortex. The aim of this paper is to report the results of a strategic analysis that involves identification of strengths, weaknesses, opportunities and threats regarding the process of achieving early amplification in all cases of significant childhood PHI. The analysis is focused on the Italian situation and is part of the Italian Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children". © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

Coping with early stage breast cancer: examining the influence of personality traits and interpersonal closeness.

PubMed

Saita, Emanuela; Acquati, Chiara; Kayser, Karen

2015-01-01

The study examines the influence of personality traits and close relationships on the coping style of women with breast cancer. A sample of 72 Italian patients receiving treatment for early stage breast cancer was recruited. Participants completed questionnaires measuring personality traits (Interpersonal Adaptation Questionnaire), interpersonal closeness (Inclusion of the Other in the Self Scale), and adjustment to cancer (Mini-Mental Adjustment to Cancer Scale). We hypothesized that diverse personality traits and degrees of closeness contribute to determine the coping styles shown by participants. Multiple regression analyses were conducted for each of the five coping styles (Helplessness/Hopelessness, Anxious Preoccupation, Avoidance, Fatalism, and Fighting Spirit) using personality traits and interpersonal closeness variables (Strength of Support Relations, and Number of Support Relations) as predictors. Women who rated high on assertiveness and social anxiety were more likely to utilize active coping strategies (Fighting Spirit). Perceived strength of relationships was predictive of using an active coping style while the number of supportive relationships did not correlate with any of the coping styles. Implications for assessment of breast cancer patients at risk for negative adaptation to the illness and the development of psychosocial interventions are discussed.

Reduced adaptability, but no fundamental disruption, of norm-based face coding following early visual deprivation from congenital cataracts.

PubMed

Rhodes, Gillian; Nishimura, Mayu; de Heering, Adelaide; Jeffery, Linda; Maurer, Daphne

2017-05-01

Faces are adaptively coded relative to visual norms that are updated by experience, and this adaptive coding is linked to face recognition ability. Here we investigated whether adaptive coding of faces is disrupted in individuals (adolescents and adults) who experience face recognition difficulties following visual deprivation from congenital cataracts in infancy. We measured adaptive coding using face identity aftereffects, where smaller aftereffects indicate less adaptive updating of face-coding mechanisms by experience. We also examined whether the aftereffects increase with adaptor identity strength, consistent with norm-based coding of identity, as in typical populations, or whether they show a different pattern indicating some more fundamental disruption of face-coding mechanisms. Cataract-reversal patients showed significantly smaller face identity aftereffects than did controls (Experiments 1 and 2). However, their aftereffects increased significantly with adaptor strength, consistent with norm-based coding (Experiment 2). Thus we found reduced adaptability but no fundamental disruption of norm-based face-coding mechanisms in cataract-reversal patients. Our results suggest that early visual experience is important for the normal development of adaptive face-coding mechanisms. © 2016 John Wiley & Sons Ltd.

Early-life Origins of Lifecycle Well-being: Research and Policy Implications

PubMed Central

Currie, Janet; Rossin-Slater, Maya

2016-01-01

Mounting evidence across different disciplines suggests that early-life conditions can have consequences on individual outcomes throughout the lifecycle. Relative to other developed countries, the United States fares poorly on standard indicators of early-life health, and this disadvantage may have profound consequences not only for population well-being, but also for economic growth and competitiveness in a global economy. In this paper, we first discuss the research on the strength of the link between early-life health and adult outcomes, and then provide an evidence-based review of the effectiveness of existing U.S. policies targeting the early-life environment. We conclude that there is a robust and economically meaningful relationship between early-life conditions and well-being throughout the lifecycle, as measured by adult health, educational attainment, labor market attachment, and other indicators of socio-economic status. However, there is some variation in the degree to which current policies in the U.S. are effective in improving early-life conditions. Among existing programs, some of the most effective are the Special Supplemental Program for Women, Infants, and Children (WIC), home visiting with nurse practitioners, and high-quality, center-based early childhood care and education. In contrast, the evidence on other policies such as prenatal care and family leave is more mixed and limited. PMID:25558491

Early-life origins of life-cycle well-being: research and policy implications.

PubMed

Currie, Janet; Rossin-Slater, Maya

2015-01-01

Mounting evidence across different disciplines suggests that early-life conditions can have consequences on individual outcomes throughout the life cycle. Relative to other developed countries, the United States fares poorly on standard indicators of early-life health, and this disadvantage may have profound consequences not only for population well-being, but also for economic growth and competitiveness in a global economy. In this paper, we first discuss the research on the strength of the link between early-life health and adult outcomes, and then provide an evidence-based review of the effectiveness of existing U.S. policies targeting the early-life environment. We conclude that there is a robust and economically meaningful relationship between early-life conditions and well-being throughout the life cycle, as measured by adult health, educational attainment, labor market attachment, and other indicators of socioeconomic status. However, there is some variation in the degree to which current policies in the United States are effective in improving early-life conditions. Among existing programs, some of the most effective are the Special Supplemental Program for Women, Infants, and Children (WIC), home visiting with nurse practitioners, and high-quality, center-based early-childhood care and education. In contrast, the evidence on other policies such as prenatal care and family leave is more mixed and limited.

Strengths and Weaknesses of Sea Ice as a Potential Early Indicator of Climate Change,

DTIC Science & Technology

Sea ice is examined for its potential as an early indicator of climate change by considering how well it satisfies four criteria listed as desired... climate change , sea ice is unlikely any time in the near future to be a definitive early indicator of climate change when considered by itself.

Early dynamics of the semantic priming shift

PubMed Central

Lavigne, Frédéric; Chanquoy, Lucile; Dumercy, Laurent; Vitu, Françoise

2013-01-01

Semantic processing of sequences of words requires the cognitive system to keep several word meanings simultaneously activated in working memory with limited capacity. The real- time updating of the sequence of word meanings relies on dynamic changes in the associates to the words that are activated. Protocols involving two sequential primes report a semantic priming shift from larger priming of associates to the first prime to larger priming of associates to the second prime, in a range of long SOAs (stimulus-onset asynchronies) between the second prime and the target. However, the possibility for an early semantic priming shift is still to be tested, and its dynamics as a function of association strength remain unknown. Three multiple priming experiments are proposed that cross-manipulate association strength between each of two successive primes and a target, for different values of short SOAs and prime durations. Results show an early priming shift ranging from priming of associates to the first prime only to priming of strong associates to the first prime and all of the associates to the second prime. We investigated the neural basis of the early priming shift by using a network model of spike frequency adaptive cortical neurons (e.g., Deco & Rolls, 2005), able to code different association strengths between the primes and the target. The cortical network model provides a description of the early dynamics of the priming shift in terms of pro-active and retro-active interferences within populations of excitatory neurons regulated by fast and unselective inhibitory feedback. PMID:23717346

Strength deficits identified with concentric action of the hip extensors and eccentric action of the hamstrings predispose to hamstring injury in elite sprinters.

PubMed

Sugiura, Yusaku; Saito, Tomoyuki; Sakuraba, Keishoku; Sakuma, Kazuhiko; Suzuki, Eiichi

2008-08-01

Prospective cohort study. In this prospective cohort study of elite sprinters, muscle strength of the hip extensors, as well as of the knee extensors and flexors, was measured to determine a possible relationship between strength deficits and subsequent hamstring injury within 12 months of testing. The method used for testing muscle strength simulated the specific muscle action during late swing and early contact phases when sprinting. There have been no prospective studies in elite sprinters that examine the concentric and eccentric isokinetic strength of the hip extensors and the quadriceps and hamstring muscles in a manner that reflects their actions in late swing or early contact phases of sprinting. Consequently, the causal relationship between hip and thigh muscle strength and hamstring injury in elite sprinters may not be fully understood. Isokinetic testing was performed on 30 male elite sprinters to assess hip extensors, quadriceps, and hamstring muscle strength. The occurrence of hamstring injury among the subjects was determined during the year following the muscle strength measurements. The strength of the hip extensors, quadriceps, and hamstring muscles, as well as the hamstrings-quadriceps and hip extensors- quadriceps ratios were compared. Hamstring injury occurred in 6 subjects during the 1-year period. Isokinetic testing at a speed of 60 degrees /s revealed weakness of the injured limb with eccentric action of the hamstring muscles and during concentric action of the hip extensors. When performing a side-to-side comparison for the injured sprinters, the hamstring injury always occurred on the weaker side. Differences in the hamstrings-quadriceps and hip extensors-quadriceps strength ratios were also evident between uninjured and injured limbs, and this was attributable to deficits in hamstring strength. Hamstring injury in elite sprinters was associated with weakness during eccentric action of the hamstrings and weakness during concentric action of the hip extensors, but only when tested at the slower speed of 60 degrees /s.

Bio-Functional Design, Application and Trends in Metallic Biomaterials

PubMed Central

Yang, Ke; Zhou, Changchun; Fan, Hongsong; Fan, Yujiang; Jiang, Qing; Song, Ping; Fan, Hongyuan; Chen, Yu; Zhang, Xingdong

2017-01-01

Introduction of metals as biomaterials has been known for a long time. In the early development, sufficient strength and suitable mechanical properties were the main considerations for metal implants. With the development of new generations of biomaterials, the concepts of bioactive and biodegradable materials were proposed. Biological function design is very import for metal implants in biomedical applications. Three crucial design criteria are summarized for developing metal implants: (1) mechanical properties that mimic the host tissues; (2) sufficient bioactivities to form bio-bonding between implants and surrounding tissues; and (3) a degradation rate that matches tissue regeneration and biodegradability. This article reviews the development of metal implants and their applications in biomedical engineering. Development trends and future perspectives of metallic biomaterials are also discussed. PMID:29271916

Bio-Functional Design, Application and Trends in Metallic Biomaterials.

PubMed

Yang, Ke; Zhou, Changchun; Fan, Hongsong; Fan, Yujiang; Jiang, Qing; Song, Ping; Fan, Hongyuan; Chen, Yu; Zhang, Xingdong

2017-12-22

Introduction of metals as biomaterials has been known for a long time. In the early development, sufficient strength and suitable mechanical properties were the main considerations for metal implants. With the development of new generations of biomaterials, the concepts of bioactive and biodegradable materials were proposed. Biological function design is very import for metal implants in biomedical applications. Three crucial design criteria are summarized for developing metal implants: (1) mechanical properties that mimic the host tissues; (2) sufficient bioactivities to form bio-bonding between implants and surrounding tissues; and (3) a degradation rate that matches tissue regeneration and biodegradability. This article reviews the development of metal implants and their applications in biomedical engineering. Development trends and future perspectives of metallic biomaterials are also discussed.

Neuroimaging of neurocutaneous diseases.

PubMed

Nandigam, Kaveer; Mechtler, Laszlo L; Smirniotopoulos, James G

2014-02-01

An in-depth knowledge of the imaging characteristics of the common neurocutaneous diseases (NCD) described in this article will help neurologists understand the screening imaging modalities in these patients. The future of neuroimaging is geared towards developing and refining magnetic resonance imaging (MRI) sequences. The detection of tumors in NCD has greatly improved with availability of high-field strength 3T MRI machines. Neuroimaging will remain at the heart and soul of the multidisciplinary care of such complex diagnoses to guide early detection and monitor treatment. Published by Elsevier Inc.

Simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

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

Taylor, Paul Allen; Ford, Corey C.

U.S. soldiers are surviving blast and impacts due to effective body armor, trauma evacuation and care. Blast injuries are the leading cause of traumatic brain injury (TBI) in military personnel returning from combat. Understanding of Primary Blast Injury may be needed to develop better means of blast mitigation strategies. The objective of this paper is to investigate the effects of blast direction and strength on the resulting mechanical stress and wave energy distributions generated in the brain.

Development of construction materials using nano-silica and aggregates recycled from construction and demolition waste.

PubMed

Mukharjee, Bibhuti Bhusan; Barai, Sudhirkumar V

2015-06-01

The present work addresses the development of novel construction materials utilising commercial grade nano-silica and recycled aggregates retrieved from construction and demolition waste. For this, experimental work has been carried out to examine the influence of nano-silica and recycled aggregates on compressive strength, modulus of elasticity, water absorption, density and volume of voids of concrete. Fully natural and recycled aggregate concrete mixes are designed by replacing cement with three levels (0.75%, 1.5% and 3%) of nano-silica. The results of the present investigation depict that improvement in early days compressive strength is achieved with the incorporation of nano-silica in addition to the restoration of reduction in compressive strength of recycled aggregate concrete mixes caused owing to the replacement of natural aggregates by recycled aggregates. Moreover, the increase in water absorption and volume of voids with a reduction of bulk density was detected with the incorporation of recycled aggregates in place of natural aggregates. However, enhancement in density and reduction in water absorption and volume of voids of recycled aggregate concrete resulted from the addition of nano-silica. In addition, the results of the study reveal that nano-silica has no significant effect on elastic modulus of concrete. © The Author(s) 2015.

Feasibility Tests on Concrete with Very-High-Volume Supplementary Cementitious Materials

PubMed Central

Yang, Keun-Hyeok; Jeon, Yong-Su

2014-01-01

The objective of this study is to examine the compressive strength and durability of very high-volume SCM concrete. The prepared 36 concrete specimens were classified into two groups according to their designed 28-day compressive strength. For the high-volume SCM, the FA level was fixed at a weight ratio of 0.4 and the GGBS level varied between the weight ratio of 0.3 and 0.5, which resulted in 70–90% replacement of OPC. To enhance the compressive strength of very high-volume SCM concrete at an early age, the unit water content was controlled to be less than 150 kg/m3, and a specially modified polycarboxylate-based water-reducing agent was added. Test results showed that as SCM ratio (R SCM) increased, the strength gain ratio at an early age relative to the 28-day strength tended to decrease, whereas that at a long-term age increased up to R SCM of 0.8, beyond which it decreased. In addition, the beneficial effect of SCMs on the freezing-and-thawing and chloride resistances of the concrete decreased at R SCM of 0.9. Hence, it is recommended that R SCM needs to be restricted to less than 0.8–0.85 in order to obtain a consistent positive influence on the compressive strength and durability of SCM concrete. PMID:25162049

EFFICACY OF THE STRETCH BAND ANKLE TRACTION TECHNIQUE IN THE TREATMENT OF PEDIATRIC PATIENTS WITH ACUTE ANKLE SPRAINS: A RANDOMIZED CONTROL TRIAL

PubMed Central

Iammarino, Kathryn; Marrie, James; Lowes, Linda P.

2018-01-01

Background Ankle injuries account for up to 40% of all sport related injuries. These injuries can result in weeks to months of missed sport or work. The PRICE (Protection, Rest, Ice, Compression, Elevation) treatment is standard care for most acute ankle sprains. Recently, early mobilization in adults has been shown to decrease time off from sport or work, and the likelihood of developing chronic instability. To date, no research has been performed assessing the effectiveness of early mobilization in pediatric patients (<18 years). Purpose: There were two objectives of this study: (1) to determine if early ankle joint mobilization using elastic band traction is effective and (2) assess the occurrence of adverse events with this technique in the pediatric population. Methods Patients with an acute ankle sprain of <7 days referred to physical therapy were randomly assigned to receive early mobilization or PRICE. Early mobilization was performed using a stretch band ankle traction technique. Both groups received a standardized rehabilitation program. Pain, edema, ankle strength using hand-held dynamometry, and Foot and Ankle Disability Index (FADI) were measured at both initial evaluation and at discharge. The number of days before return to sport and the number of treatment sessions were also variables of interest. Results Forty-one pediatric patients were recruited for participation (mean age 14.6 + 1.9 years). Both treatment groups had clinically significant improvements in pain, edema, strength, and FADI scores. No significant differences in outcomes were noted between treatment groups. Mean number of days for return to sport for the PRICE group was 26.33 + 7.14 and the early mobilization group was 26.63 + 14.82, the difference between groups was not significant (p = 0.607). The number of total visits for the PRICE group of 8.07 + 2.63 and the early mobilization groups of 8.5 + 1.57, was also not statistically significantly different (p = 0.762). There were no reported adverse events with early mobilization. Conclusion Early mobilization appears to be a safe intervention in pediatric patients with an acute ankle sprain. Early mobilization resulted in similar outcomes when compared to traditional PRICE treatment. A high drop-out rate in both treatment groups was a limitation of this randomized trial. Level of evidence 1b PMID:29484236

EFFICACY OF THE STRETCH BAND ANKLE TRACTION TECHNIQUE IN THE TREATMENT OF PEDIATRIC PATIENTS WITH ACUTE ANKLE SPRAINS: A RANDOMIZED CONTROL TRIAL.

PubMed

Iammarino, Kathryn; Marrie, James; Selhorst, Mitchell; Lowes, Linda P

2018-02-01

Ankle injuries account for up to 40% of all sport related injuries. These injuries can result in weeks to months of missed sport or work. The PRICE (Protection, Rest, Ice, Compression, Elevation) treatment is standard care for most acute ankle sprains. Recently, early mobilization in adults has been shown to decrease time off from sport or work, and the likelihood of developing chronic instability. To date, no research has been performed assessing the effectiveness of early mobilization in pediatric patients (<18 years). Purpose: There were two objectives of this study: (1) to determine if early ankle joint mobilization using elastic band traction is effective and (2) assess the occurrence of adverse events with this technique in the pediatric population. Patients with an acute ankle sprain of <7 days referred to physical therapy were randomly assigned to receive early mobilization or PRICE. Early mobilization was performed using a stretch band ankle traction technique. Both groups received a standardized rehabilitation program. Pain, edema, ankle strength using hand-held dynamometry, and Foot and Ankle Disability Index (FADI) were measured at both initial evaluation and at discharge. The number of days before return to sport and the number of treatment sessions were also variables of interest. Forty-one pediatric patients were recruited for participation (mean age 14.6 + 1.9 years). Both treatment groups had clinically significant improvements in pain, edema, strength, and FADI scores. No significant differences in outcomes were noted between treatment groups. Mean number of days for return to sport for the PRICE group was 26.33 + 7.14 and the early mobilization group was 26.63 + 14.82, the difference between groups was not significant ( p = 0.607). The number of total visits for the PRICE group of 8.07 + 2.63 and the early mobilization groups of 8.5 + 1.57, was also not statistically significantly different ( p = 0.762). There were no reported adverse events with early mobilization. Early mobilization appears to be a safe intervention in pediatric patients with an acute ankle sprain. Early mobilization resulted in similar outcomes when compared to traditional PRICE treatment. A high drop-out rate in both treatment groups was a limitation of this randomized trial. 1b.

Evolution of Meso-Cenozoic lithospheric thermal-rheological structure in the Jiyang sub-basin, Bohai Bay Basin, eastern North China Craton

NASA Astrophysics Data System (ADS)

Xu, Wei; Qiu, Nansheng; Wang, Ye; Chang, Jian

2018-01-01

The Meso-Cenozoic lithospheric thermal-rheological structure and lithospheric strength evolution of the Jiyang sub-basin were modeled using thermal history, crustal structure, and rheological parameter data. Results indicate that the thermal-rheological structure of the Jiyang sub-basin has exhibited obvious rheological stratification and changes over time. During the Early Mesozoic, the uppermost portion of the upper crust, middle crust, and the top part of the upper mantle had a thick brittle layer. During the early Early Cretaceous, the top of the middle crust's brittle layer thinned because of lithosphere thinning and temperature increase, and the uppermost portion of the upper mantle was almost occupied by a ductile layer. During the late Early Cretaceous, the brittle layer of the middle crust and the upper mantle changed to a ductile one. Then, the uppermost portion of the middle crust changed to a thin brittle layer in the late Cretaceous. During the early Paleogene, the thin brittle layer of the middle crust became even thinner and shallower under the condition of crustal extension. Currently, with the decrease in lithospheric temperature, the top of the upper crust, middle crust, and the uppermost portion of the upper mantle are of a brittle layer. The total lithospheric strength and the effective elastic thickness ( T e) in Meso-Cenozoic indicate that the Jiyang sub-basin experienced two weakened stages: during the late Early Cretaceous and the early Paleogene. The total lithospheric strength (approximately 4-5 × 1013 N m-1) and T e (approximately 50-60 km) during the Early Mesozoic was larger than that after the Late Jurassic (2-7 × 1012 N m-1 and 19-39 km, respectively). The results also reflect the subduction, and rollback of Pacific plate is the geodynamic mechanism of the destruction of the eastern North China Craton.

Design protocols and analytical strategies that incorporate structural reliability models

NASA Technical Reports Server (NTRS)

Duffy, Stephen F.

1995-01-01

In spite of great improvements in accuracy through the use of computers, design methods, which can be equally critical in establishing the commercial success of a material, have been treated as afterthoughts. Early investment in design and development technologies can easily reduce manufacturing costs later in the product cycle. To avoid lengthy product development times for ceramic composites, funding agencies for materials research must commit resources to support design and development technologies early in the material life cycle. These technologies need not focus on designing the material, rather, the technology must focus on designing with the material, i. e., developing methods to design components fabricated from the new material. Thus a basic tenet that motivated this research effort is that a persistent need exists for improvements in the analysis of components fabricated from CMC material systems. From an aerospace design engineer's perspective the new generation of ceramic composites offers a significant potential for raising the thrust/weight ratio and reducing NOx emissions of gas turbine engines. Continuous ceramic fiber composites exhibit an increase in work of fracture, which allows for 'graceful' rather than catastrophic failure. When loaded in the fiber direction, these composites retain substantial strength capacity beyond the initiation of transverse matrix cracking despite the fact that neither of its constituents would exhibit such behavior if tested alone. As additional load is applied beyond first matrix cracking, the matrix tends to break in a series of cracks bridged by the ceramic fibers. Thus any additional load is born increasingly by the fibers until the ultimate strength of the composite is reached. Establishing design protocols that enable the engineer to analyze and predict this type of behavior in ceramic composites was the general goal of this project.

Design protocols and analytical strategies that incorporate structural reliability models

NASA Astrophysics Data System (ADS)

Duffy, Stephen F.

1995-08-01

In spite of great improvements in accuracy through the use of computers, design methods, which can be equally critical in establishing the commercial success of a material, have been treated as afterthoughts. Early investment in design and development technologies can easily reduce manufacturing costs later in the product cycle. To avoid lengthy product development times for ceramic composites, funding agencies for materials research must commit resources to support design and development technologies early in the material life cycle. These technologies need not focus on designing the material, rather, the technology must focus on designing with the material, i. e., developing methods to design components fabricated from the new material. Thus a basic tenet that motivated this research effort is that a persistent need exists for improvements in the analysis of components fabricated from CMC material systems. From an aerospace design engineer's perspective the new generation of ceramic composites offers a significant potential for raising the thrust/weight ratio and reducing NOx emissions of gas turbine engines. Continuous ceramic fiber composites exhibit an increase in work of fracture, which allows for 'graceful' rather than catastrophic failure. When loaded in the fiber direction, these composites retain substantial strength capacity beyond the initiation of transverse matrix cracking despite the fact that neither of its constituents would exhibit such behavior if tested alone. As additional load is applied beyond first matrix cracking, the matrix tends to break in a series of cracks bridged by the ceramic fibers. Thus any additional load is born increasingly by the fibers until the ultimate strength of the composite is reached. Establishing design protocols that enable the engineer to analyze and predict this type of behavior in ceramic composites was the general goal of this project.

The Science of Cost-Effective Materials Design - A Study in the Development of a High Strength, Impact Resistant Steel

NASA Astrophysics Data System (ADS)

Abrahams, Rachel

2017-06-01

Intermediate alloy steels are widely used in applications where both high strength and toughness are required for extreme/dynamic loading environments. Steels containing greater than 10% Ni-Co-Mo are amongst the highest strength martensitic steels, due to their high levels of solution strengthening, and preservation of toughness through nano-scaled secondary hardening, semi-coherent hcp-M2 C carbides. While these steels have high yield strengths (σy 0.2 % >1200 MPa) with high impact toughness values (CVN@-40 >30J), they are often cost-prohibitive due to the material and processing cost of nickel and cobalt. Early stage-I steels such as ES-1 (Eglin Steel) were developed in response to the high cost of nickel-cobalt steels and performed well in extreme shock environments due to the presence of analogous nano-scaled hcp-Fe2.4 C epsilon carbides. Unfortunately, the persistence of W-bearing carbides limited the use of ES-1 to relatively thin sections. In this study, we discuss the background and accelerated development cycle of AF96, an alternative Cr-Mo-Ni-Si stage-I temper steel using low-cost heuristic and Integrated Computational Materials Engineering (ICME)-assisted methods. The microstructure of AF96 was tailored to mimic that of ES-1, while reducing stability of detrimental phases and improving ease of processing in industrial environments. AF96 is amenable to casting and forging, deeply hardenable, and scalable to 100,000 kg melt quantities. When produced at the industrial scale, it was found that AF96 exhibits near-statistically identical mechanical properties to ES-1 at 50% of the cost.

Early ICU Standardized Rehabilitation Therapy for the Critically Inijured Burn Patient

DTIC Science & Technology

2013-10-01

strength assessments) post-enrollment. Functional testing with Short Physical Performance Battery ( SPPB ) and Health Related Quality of Life (HRQoL... testing will determine if standardized early rehab improves functional performance quality of life and employment status. Accomplishments Year #1

Values in Action with Early School

ERIC Educational Resources Information Center

Digney, Alison; Digney, John

2013-01-01

At a conference where he received the Circle of Courage Award, psychologist Christopher Peterson (Peterson & Brendtro, 2008) noted that there is something about the architecture of the human mind that causes it to overlook strengths. He suggested three reasons the focus needs to shift to strengths: (1) competence makes life most worth living;…

Parent-Adolescent Relationships and Its Association to Adolescents’ Self-Esteem

PubMed Central

Yaacob, Mohd Jamil bin

2006-01-01

Psychoanalysts believed that early mother-child relationships form the prototype of all future relationships and the outcome of adolescents development depends on their ego-strength. Object relations theory believed that intrapsychic process mediates interpersonal interaction to develop a sense of secure self and adolescents must relinquish the internalized other in order to develop a more mature sense of self. Social-relation theory believed that mothers and fathers provide different socialization experiences. Self-esteem depends on the functioning of the whole family in which adolescent is intimately related to the dyadic relationship in a family. There is an association between interparental conflict and adolescent’s self-esteem and problem behaviour. PMID:22589586

Feedback Seeking in Early Adolescence: Self-Enhancement or Self-Verification?

PubMed

Rosen, Lisa H; Principe, Connor P; Langlois, Judith H

2013-02-13

The authors examined whether early adolescents ( N = 90) solicit self-enhancing feedback (i.e., positive feedback) or self-verifying feedback (i.e., feedback congruent with self-views, even when these views are negative). Sixth, seventh, and eighth graders first completed a self-perception measure and then selected whether to receive positive or negative feedback from an unknown peer in different domains of self. Results were consistent with self-verification theory; adolescents who perceived themselves as having both strengths and weaknesses were more likely to seek negative feedback regarding a self-perceived weakness compared to a self-perceived strength. The authors found similar support for self-verification processes when they considered the entire sample regardless of perceived strengths and weaknesses; hierarchical linear modeling (HLM) examined the predictive power of ratings of self-perceived ability, certainty, and importance on feedback seeking for all participants and provided additional evidence of self-verification strivings in adolescence.

Feedback Seeking in Early Adolescence: Self-Enhancement or Self-Verification?

PubMed Central

Rosen, Lisa H.; Principe, Connor P.; Langlois, Judith H.

2012-01-01

The authors examined whether early adolescents (N = 90) solicit self-enhancing feedback (i.e., positive feedback) or self-verifying feedback (i.e., feedback congruent with self-views, even when these views are negative). Sixth, seventh, and eighth graders first completed a self-perception measure and then selected whether to receive positive or negative feedback from an unknown peer in different domains of self. Results were consistent with self-verification theory; adolescents who perceived themselves as having both strengths and weaknesses were more likely to seek negative feedback regarding a self-perceived weakness compared to a self-perceived strength. The authors found similar support for self-verification processes when they considered the entire sample regardless of perceived strengths and weaknesses; hierarchical linear modeling (HLM) examined the predictive power of ratings of self-perceived ability, certainty, and importance on feedback seeking for all participants and provided additional evidence of self-verification strivings in adolescence. PMID:23543746

Does perceived stress moderate the association between depressive symptoms and socioemotional and behavioural strengths and difficulties in adolescence?

PubMed

Lätsch, Alexander

2018-04-01

More and more students report high level of perceived stress during childhood and adolescence, which is associated with socioemotional and behavioural strengths and difficulties. This study aims-based on the cognitive vulnerability-transactional stress theory-to examine perceived stress in early adolescence as a potential moderator in the association between depressive symptoms and socioemotional and behavioural strengths and difficulties from early to middle adolescence. Results of latent moderated structural equations with questionnaire data from a longitudinal study with 1,088 German students (Time 1: M age  = 13.70, SD = 0.53; Time 2: N = 845, M age  = 15.32, SD = 0.49) indicate that perceived stress functions as a moderator in the above-mentioned association and dominates the interaction if perceived strongly. Copyright © 2017 John Wiley & Sons, Ltd.

Myasthenia Gravis and the Myasthenic Syndrome

PubMed Central

Herrmann, Christian

1970-01-01

Two disorders of neuromuscular transmission producing muscle weakness and easy fatigability which may confront the physician are myasthenia gravis and the myasthenic syndrome. The former has early symptoms and signs of oculobulbar and then extremity weakness with rapid decline of action potential and contractile strength with repetitive use and nerve-muscle stimulation. Anticholinesterases improve strength. The myasthenic syndrome has early symptoms and signs of pelvic girdle, pectoral girdle and proximal limb muscle weakness. This is worst when first starting to use or carry out nerve muscle stimulation in the rested muscles. It improves significantly for a time with use or on rapid stimulation, and then declines with continued activation. Deep tendon reflexes are sluggish or absent. Small cell carcinoma of the lung is often associated. Guanidine improves the strength. Other features and possible underlying mechanisms of the two disorders help to differentiate and treat them. PMID:5457513

Early age strength increase of fly ash blended cement by a ternary hardening accelerating admixture

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

Hoang, Kien; Justnes, Harald; SINTEF Building and Infrastructure

The applicability of a combination of sodium thiocyanate (NaSCN), diethanolamine (DEA) and glycerol (Gly) with small dosages as a ternary hardening accelerating admixture for fly ash blended cement (OPC-FA) was studied. The ternary admixture induced higher early and later age mortar strength at both low (5 °C) and normal (20 °C) temperature. Despite used in lower dosage the ternary admixture led to higher strength of the investigated OPC-FA system than other chemicals (e.g. sodium sulfate). Results obtained from isothermal calorimetry, thermogravimetric analysis (TGA) and X-ray diffraction (XRD) showed that the ternary admixture accelerated the cement hydration and increased the amountmore » of AFm (notably calcium hemicarboaluminate hydrate) in the hydration products. A synergistic effect between the three components of the accelerator on the hydration of OPC-FA system was observed.« less

A Study on the Properties of Carbon Black Mortar Using Granulated Blast Furnace Slag and Polymer.

PubMed

Jang, Hong-Seok; Jeon, Ui-Hyeon; So, Seung-Young

2015-11-01

White Portland Cement (WPC) and inorganic pigment have been used in colored concrete, but there are some physical problems such as increases in efflorescence, and poor workability and low economics. The aim of this study was to investigate the effects of GBFS and polymer (methyl cellulose) on the physical properties of carbon black mortar. For this purpose, a flow test, compressive strength test and color evaluation and was carried out on cement mortar mixed with polymer by changing the proportion of cement and ratio of GBFS. The results show that the addition of polymer influences significantly the color value efficiency in colored mortar. This is due to the reduction of overall amount of micro pore. This polymer films prevent the transport of soluble calcium towards the surface, and decreases efflorescence. And the flow of colored mortar was increased in proportion to the addition rate of the GBFS. In addition the strength of colored mortars with GBFS at the long-term aged (after 28 days) was higher than that of the general WPC mortar, although its strength was developed slowly at the early ages.

Exercise at Different Ages and Appendicular Lean Mass and Strength in Later Life: Results From the Berlin Aging Study II.

PubMed

Eibich, Peter; Buchmann, Nikolaus; Kroh, Martin; Wagner, Gert G; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja; Norman, Kristina

2016-04-01

Excessive loss of muscle mass in advanced age is a major risk factor for decreased physical ability and falls. Physical activity and exercise training are typically recommended to maintain muscle mass and prevent weakness. How exercise in different stages of life relates to muscle mass, grip strength, and risk for weakness in later life is not well understood. Baseline data on 891 participants at least 60 years old from the Berlin Aging Study II (BASE-II) were analyzed. Linear and logistic regressions of self-reported exercise in early adulthood, old age, or both on appendicular lean mass (ALM), grip strength, and a risk indicator for weakness (ALM/ body mass index cutoff) were calculated. In addition, treatment bounds are analyzed to address potential confounding using a method proposed by Oster. Analyses indicate that for men only, continuous exercise is significantly associated with higher muscle mass (SD = 0.24, p < .001), grip strength (SD = 0.18, p < .05), and lower risk for clinically relevant low muscle mass (odds ratio = 0.36, p < .01). Exercise in early adulthood alone is not significantly associated with muscle mass or strength. No significant associations were observed for women. The results of the current study underscore the importance of health programs to promote physical activity with a focus on young adults, a group known to be affected from environmentally associated decline of physical activity, and to promote the continuation of physical exercise from early adulthood into later life in general. © 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.

Early age compressive strength, porosity, and sorptivity of concrete using peat water to produce and cure concrete

NASA Astrophysics Data System (ADS)

Olivia, Monita; Ismeddiyanto, Wibisono, Gunawan; Sitompul, Iskandar R.

2017-09-01

Construction in peatland has faced scarce water sources for mixing and curing concrete. It is known that peat water has high organic content and low pH that can be harmful to concrete in the environment. In some remote areas in Riau Province, contractors used peat water directly without sufficient treatments to comply with SKSNI requirements of concrete mixing water. This paper presents a study of compressive strength, porosity and sorptivity of Ordinary Portland Cement (OPC) and blended OPC-Palm Oil Fuel Ash (OPC-POFA) concrete. The specimens were mixed using natural water and peat water, then some of them were cured in fresh water and peat water. Six mixtures were investigated using a variation of cement, mixing water and curing water. Tap water is used as control mixing and curing water for all specimens. The compressive strength, porosity and sorptivity were calculated at seven and 28 days. Results indicate that the use of peat water will cause low compressive strength, high porosity and sorptivity for both OPC and OPC-POFA concrete. Using peat water and curing the specimens in tap water could improve the early strength, porosity and sorptivity of OPC concrete; however, it has an adverse effect on OPC-POFA specimens. The properties of early age concrete of both types (OPC and OPC-POFA) using peat water were as good as those with tap water. Therefore, it is suggested that peat water should be considered as mixing and curing water for concrete where tap water resources are scarce. Investigation of its long-term properties, as well as extending the observed age of concrete is recommended before any use of peat water.

Racial differences in cortical bone and their relationship to biochemical variables in black and white children in the early stages of puberty

PubMed Central

Warden, Stuart J.; Hill, Kathleen M.; Ferira, Ashley J.; Laing, Emma M.; Martin, Berdine R.; Hausman, Dorothy B.; Weaver, Connie M.; Peacock, Munro; Lewis, Richard D.

2014-01-01

Introduction Racial differences in bone structure likely have roots in childhood as bone size develops predominantly during growth. This study aimed to compare cortical bone health within the tibial diaphysis of black and white children in the early stages of puberty, and explore the contributions of biochemical variables in explaining racial variation in cortical bone properties. Methods A cross-sectional study was performed comparing peripheral quantitative computed tomography-derived cortical bone measures of the tibial diaphysis and biochemical variables in 314 participants (n=155 males; n=164 blacks) in the early stages of puberty. Results Blacks had greater cortical volumetric bone mineral density, mass and size compared to whites (all p<0.01), contributing to blacks having 17.0% greater tibial strength (polar strength-strain index [SSIP]) (p<0.001). Turnover markers indicated blacks had higher bone formation (osteocalcin [OC] and bone specific alkaline phosphatase) and lower bone resorption (N-terminal telopeptide) than whites (all p<0.01). Blacks also had lower 25-hydroxyvitamin D [25(OH)D], and higher 1,25-dihydroxyvitamin D [1,25(OH)2D] and parathyroid hormone (PTH) (all p<0.05). There were no correlations between tibial bone properties, and 25(OH)D and PTH in whites (all p≥0.10); however, SSIP was negatively and positively correlated with 25(OH)D and PTH in blacks, respectively (all p≤0.02). Variation in bone cross-sectional area and SSIP attributable to race was partially explained by tibial length, 25(OH)D/PTH and OC. Conclusions Divergence in tibial cortical bone properties between blacks and whites is established by the early stages of puberty with the enhanced cortical bone properties in black children possibly being explained by higher PTH and OC. PMID:23093348

Thresholds in forest bird occurrence as a function of the amount of early-seral broadleaf forest at landscape scales

USGS Publications Warehouse

Betts, M.G.; Hagar, J.C.; Rivers, J.W.; Alexander, J.D.; McGarigal, K.; McComb, B.C.

2010-01-01

Recent declines in broadleaf-dominated, early-seral forest globally as a function of intensive forest management and/or fire suppression have raised concern about the viability of populations dependent on such forest types. However, quantitative information about the strength and direction of species associations with broadleaf cover at landscape scales are rare. Uncovering such habitat relationships is essential for understanding the demography of species and in developing sound conservation strategies. It is particularly important to detect points in habitat reduction where rates of population decline may accelerate or the likelihood of species occurrence drops rapidly (i.e., thresholds). Here, we use a large avian point-count data set (N = 4375) from southwestern and northwestern Oregon along with segmented logistic regression to test for thresholds in forest bird occurrence as a function of broadleaf forest and early-seral broadleaf forest at local (150-m radius) and landscape (500–2000-m radius) scales. All 12 bird species examined showed positive responses to either broadleaf forest in general, and/or early-seral broadleaf forest. However, regional variation in species response to these conditions was high. We found considerable evidence for landscape thresholds in bird species occurrence as a function of broadleaf cover; threshold models received substantially greater support than linear models for eight of 12 species. Landscape thresholds in broadleaf forest ranged broadly from 1.35% to 24.55% mean canopy cover. Early-seral broadleaf thresholds tended to be much lower (0.22–1.87%). We found a strong negative relationship between the strength of species association with early-seral broadleaf forest and 42-year bird population trends; species most associated with this forest type have declined at the greatest rates. Taken together, these results provide the first support for the hypothesis that reductions in broadleaf-dominated early-seral forest due to succession and intensive forest management have led to population declines of constituent species in the Pacific northwestern United States. Forest management treatments that maintain or restore even small amounts of broadleaf vegetation could mitigate further declines.

Effects of Aerobic Exercise Applied Early After Coronary Artery Bypass Grafting on Pulmonary Function, Respiratory Muscle Strength, and Functional Capacity: A Randomized Controlled Trial.

PubMed

Borges, Daniel L; Silva, Mayara Gabrielle; Silva, Luan Nascimento; Fortes, João Vyctor; Costa, Erika Thalita; Assunção, Rebeca Pessoa; Lima, Carlos Magno; da Silva Nina, Vinícius José; Bernardo-Filho, Mário; Caputo, Danúbia Sá

2016-09-01

Physical activity is beneficial in several clinical situations and recommended for patients with ischemic heart disease, as well as for those undergoing cardiac surgery. In a randomized controlled trial, 34 patients underwent coronary artery bypass grafting. A randomized control group (n = 15) submitted to conventional physiotherapy. The intervention group (n = 19) received the same protocol plus additional aerobic exercise with cycle ergometer. Pulmonary function by spirometry, respiratory muscle strength by manovacuometry, and functional capacity through 6-minute walking test was assessed before surgery and at hospital discharge. There was significant reduction in pulmonary function in both groups. In both groups, inspiratory muscle strength was maintained while expiratory muscle strength significantly decreased. Functional capacity was maintained in the intervention group (364.5 [324.5 to 428] vs. 348 [300.7 to 413.7] meters, P = .06), but it decreased significantly in control group patients (320 [288.5 to 393.0] vs. 292 [237.0 to 336.0] meters, P = .01). A significant difference in functional capacity was also found in intergroup analyses at hospital discharge (P = .03). Aerobic exercise applied early on coronary artery bypass grafting patients may promote maintenance of functional capacity, with no impact on pulmonary function and respiratory muscle strength when compared with conventional physiotherapy.

Muscle Weakness Thresholds for Prediction of Diabetes in Adults.

PubMed

Peterson, Mark D; Zhang, Peng; Choksi, Palak; Markides, Kyriakos S; Al Snih, Soham

2016-05-01

Despite the known links between weakness and early mortality, what remains to be fully understood is the extent to which strength preservation is associated with protection from cardiometabolic diseases, such as diabetes. The purposes of this study were to determine the association between muscle strength and diabetes among adults, and to identify age- and sex-specific thresholds of low strength for detection of risk. A population-representative sample of 4066 individuals, aged 20-85 years, was included from the combined 2011-2012 National Health and Nutrition Examination Survey (NHANES) data sets. Strength was assessed using a handheld dynamometer, and the single highest reading from either hand was normalized to body mass. A logistic regression model was used to assess the association between normalized grip strength and risk of diabetes, as determined by haemoglobin A1c levels ≥6.5 % (≥48 mmol/mol), while controlling for sociodemographic characteristics, anthropometric measures and television viewing time. For every 0.05 decrement in normalized strength, there were 1.26 times increased adjusted odds for diabetes in men and women. Women were at lower odds of having diabetes (odds ratio 0.49; 95 % confidence interval 0.29-0.82). Age, waist circumference and lower income were also associated with diabetes. The optimal sex- and age-specific weakness thresholds to detect diabetes were 0.56, 0.50 and 0.45 for men at ages of 20-39, 40-59 and 60-80 years, respectively, and 0.42, 0.38 and 0.33 for women at ages of 20-39, 40-59 and 60-80 years, respectively. We present thresholds of strength that can be incorporated into a clinical setting for identifying adults who are at risk of developing diabetes and might benefit from lifestyle interventions to reduce risk.

Muscle Weakness Thresholds for Prediction of Diabetes in Adults

PubMed Central

Peterson, Mark D.; Zhang, Peng; Choksi, Palak; Markides, Kyriakos S.; Al Snih, Soham

2016-01-01

Background Despite the known links between weakness and early mortality, what remains to be fully understood is the extent to which strength preservation is associated with protection from cardiometabolic diseases such as diabetes. Purpose The purposes of this study were to determine the association between muscle strength and diabetes among adults, and to identify age- and sex-specific thresholds of low strength for detection of risk. Methods A population-representative sample of 4,066 individuals, aged 20–85 years, was included from the combined 2011–2012 National Health and Nutrition Examination Survey datasets. Strength was assessed using a hand-held dynamometer, and the single largest reading from either hand was normalized to body mass. A logistic regression model was used to assess the association between normalized grip strength and risk of diabetes, as determined by hemoglobin A1c (HbA1c) levels (≥6.5% [≥48 mmol/mol]), while controlling for sociodemographic characteristics, anthropometric measures, and television viewing time. Results For every 0.05 decrement in normalized strength, there was a 1.26 times increased adjusted odds for diabetes in men and women. Women were at lower odds of having diabetes (OR: 0.49; 95% CI: 0.29–0.82), whereas age, waist circumference and lower income were inversely associated. Optimal sex- and age-specific weakness thresholds to detect diabetes were 0.56, 0.50, and 0.45 for men, and 0.42, 0.38, and 0.33 for women, for ages 20–39 years, 40–59 years, and 60–80 years. Conclusions and Clinical Relevance We present thresholds of strength that can be incorporated into a clinical setting for identifying adults that are at risk for developing diabetes, and that might benefit from lifestyle interventions to reduce risk. PMID:26744337

Preliminary study of the biomechanical behavior and physical characteristics of tantalum (Ta)-coated prostheses.

PubMed

Duan, Yonghong; Liu, Lie; Wang, Ling; Guo, Fei; Li, Haoping; Shi, Lei; Li, Mao; Yin, Dayu; Jiang, Chi; Zhu, Qingsheng

2012-03-01

Use of Ta biomaterials in medicine started in the middle of the last century. The good biocompatibility and chemical stability, and the unique physical characteristics of Ta metal have resulted in many possible developments of Ta biomaterials. In this study, histopathological observation, histomorphometric analysis, scanning electron microscope (SEM) observation, energy-dispersive X-ray spectroscopy (EDX) analysis, biomechanical testing, and examination of the coating's mechanical strength have been used to evaluate the value of clinical application of Ta-coated prostheses prepared by a plasma-spraying process. Histopathological observation has demonstrated that the periprosthetic new bone tissues tightly and stably adhere to the Ta coating after the implantation, with no signs of loosening. Early after implantation, there is no significant difference in periprosthetic bone volume and ultimate shear strength between Ta-coated and Ti-coated prostheses (P > 0.05). EDX analysis suggests that the ultimate shear stress does not damage Ta coating. Mechanical strength testing shows that the adhesive strength and Vicker's surface hardness (HV) of the Ta coating are significantly higher than those of the Ti coating (P < 0.01). Ta coating has good stability and bone biocompatibility; the extraordinary physical characteristics of Ta coating have great significance in maintaining prosthetic stability and surface porosity after implantation.

Assessment of Tablet Surface Hardness by Laser Ablation and Its Correlation With the Erosion Tendency of Core Tablets.

PubMed

Narang, Ajit S; Breckenridge, Lydia; Guo, Hang; Wang, Jennifer; Wolf, Abraham Avi; Desai, Divyakant; Varia, Sailesh; Badawy, Sherif

2017-01-01

Surface erosion of uncoated tablets results in processing problems such as dusting and defects during coating and is governed by the strength of particle bonding on tablet surface. In this study, the correlation between dusting tendency of tablets in a coating pan with friability and laser ablation surface hardness was assessed using tablets containing different concentrations of magnesium stearate and tartaric acid. Surface erosion propensity of different batches was evaluated by assessing their dusting tendency in the coating pan. In addition, all tablets were analyzed for crushing strength, friability, modified friability test using baffles in the friability apparatus, and weight loss after laser ablation. Tablets with similar crushing strength showed differences in their surface erosion and dusting tendency when rotated in a coating pan. These differences did not correlate well with tablet crushing strength or friability but did show reasonably good correlation with mass loss after laser ablation. These results suggest that tablet surface mass loss by laser ablation can be used as a minipiloting (small-scale) tool to assess tablet surface properties during early stages of drug product development to assess the risk of potential large-scale manufacturing issues. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Examining platelet-fibrin interactions during traumatic shock in a swine model using platelet contractile force and clot elastic modulus.

PubMed

White, Nathan J; Martin, Erika J; Brophy, Donald F; Ward, Kevin R

2011-07-01

A significant proportion of severely injured patients develop early coagulopathy, characterized by abnormal clot formation, which impairs resuscitation and increases mortality. We have previously demonstrated an isolated decrease in clot strength by thrombelastography in a swine model of nonresuscitated traumatic shock. In order to more closely examine platelet-fibrin interactions in this setting, we define the observed decrease in clot strength in terms of platelet-induced clot contraction and clot elastic modulus using the Hemostasis Analysis System (HAS) (Hemodyne Inc., Richmond, Virginia, USA). Whole blood was sampled for HAS measurements, metabolic measurements, cell counts, and fibrinogen concentration at baseline prior to injury and again at a predetermined level of traumatic shock defined by oxygen debt. Male swine (N=17) received femur fracture and controlled arterial hemorrhage to achieve an oxygen debt of 80 ml/kg. Platelet counts were unchanged, but fibrinogen concentration was reduced significantly during shock (167.6 vs. 66.7 mg/dl, P=0.0007). Platelet contractile force generated during clot formation did not change during shock (11.7 vs. 10.4 kdynes, P=0.41), but clot elastic modulus was dynamically altered, resulting in a lower final value (22.9 vs. 17.3 kdynes/cm, P<0.0001). In this model of traumatic shock, platelet function was preserved, whereas terminal clot elastic modulus was reduced during shock in a manner most consistent with early changes in the mechanical properties of the developing fibrin fiber network.

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

PubMed

Mottron, Laurent

2017-07-01

Early intensive behavioral intervention (EIBI) and its recent variant, naturalist developmental behavioral intervention (NDBI) aim to increase socialization and communication, and to decrease repetitive and challenging behaviors in preschool age autistic children. These behaviorist techniques are based on the precocity and intensity of the intervention, face-to-face interaction, errorless learning, and information fragmentation. Once considered to be "scientifically proven", the efficacy of these approaches has been called into question in the last decade due to poor-quality data, small effects, low cost-efficiency, and the evolution of ethical and societal standards. Grounded on a reappraisal of the genetic and cognitive neuroscience of autism, we question three aspects of EIBI/NDBI: their focus on prerequisites for typical socio-communicative behaviors, their lack of consideration of autistic language development and learning modes, and their negative view of repetitive behaviors and restricted interests. We propose alternative predictions for empirical validation, based on the strengths of prototypical autistic children: (a) their non-verbal intelligence should be normally distributed and within the normal range; (b) improving access to non-communicative verbal and written auditory language material should favor their subsequent speech development and (c) decrease their problematic behavior; (d) lateral tutorship should increase the well-being of children and parents to a greater extent than personalized, face-to-face interventions by professionals; (e) admission to regular, but supervised daycare centers, combined with parental support and on-site crisis solving, represents a more cost-effective educational intervention than EIBI/NDBI.

A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect.

PubMed

Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A J

2017-01-01

This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students ( N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.

Strength of small-diameter round and tapered bending members

Treesearch

Ron Wolfe; Joe Murphy

2005-01-01

An early focus on structural use of processed rather than round timber resulted in an underestimation of the structural advantages of retaining the natural form of small-diameter round timber. In the round and tapered form, timbers are not susceptible to the strength-reducing effects of diving grain and exposed juvenile wood. Fiber continuity around knots on the...

Understanding the effects of low salinity on fertilization success and early development in the sand dollar Echinarachnius parma.

PubMed

Allen, Jonathan D; Pechenik, Jan A

2010-04-01

Free-spawning marine invertebrates that live near shore or in estuaries may experience reduced fertilization success during low-salinity events. Although several studies have documented reproductive failure at reduced salinity in estuarine animals, few have looked at whether developmental failure is due to a failure of fertilization or to a failure of fertilized eggs to cleave. In this study, we examined the effects of salinities ranging from 18 to 32 psu on fertilization success and early development in the sand dollar Echinarachnius parma. In addition to decoupling the effects of low salinity on fertilization from its effects on early cleavage, we also assessed whether eggs or sperm were the weak link in accounting for reproductive failure. We found that both fertilization and cleavage failed at salinities below about 22 psu but that development could be partially rescued by returning zygotes to full-strength seawater. We also found that sperm remained active and capable of fertilizing eggs even after being exposed to low salinities for 30 min.. Taken together, these results suggest that reproductive failure at low salinities in E. parma is due more to an inability of the fertilized eggs to cleave than to an inability of sperm to fertilize eggs.

Evaluating markers for the early detection of cancer: overview of study designs and methods.

PubMed

Baker, Stuart G; Kramer, Barnett S; McIntosh, Martin; Patterson, Blossom H; Shyr, Yu; Skates, Steven

2006-01-01

The field of cancer biomarker development has been evolving rapidly. New developments both in the biologic and statistical realms are providing increasing opportunities for evaluation of markers for both early detection and diagnosis of cancer. To review the major conceptual and methodological issues in cancer biomarker evaluation, with an emphasis on recent developments in statistical methods together with practical recommendations. We organized this review by type of study: preliminary performance, retrospective performance, prospective performance and cancer screening evaluation. For each type of study, we discuss methodologic issues, provide examples and discuss strengths and limitations. Preliminary performance studies are useful for quickly winnowing down the number of candidate markers; however their results may not apply to the ultimate target population, asymptomatic subjects. If stored specimens from cohort studies with clinical cancer endpoints are available, retrospective studies provide a quick and valid way to evaluate performance of the markers or changes in the markers prior to the onset of clinical symptoms. Prospective studies have a restricted role because they require large sample sizes, and, if the endpoint is cancer on biopsy, there may be bias due to overdiagnosis. Cancer screening studies require very large sample sizes and long follow-up, but are necessary for evaluating the marker as a trigger of early intervention.

Electrical stimulation in exercise training

NASA Technical Reports Server (NTRS)

Kroll, Walter

1994-01-01

Electrical stimulation has a long history of use in medicine dating back to 46 A.D. when the Roman physician Largus found the electrical discharge of torpedo fishes useful in the treatment of pain produced by headache and gout. A rival Greek physician, Dioscorides, discounted the value of the torpedo fish for headache relief but did recommend its use in the treatment of hemorrhoids. In 1745, the Leyden jar and various sized electrostatic generators were used to treat angina pectoris, epilepsy, hemiplegia, kidney stones, and sciatica. Benjamin Franklin used an electrical device to treat successfully a young woman suffering from convulsive fits. In the late 1800's battery powered hydroelectric baths were used to treat chronic inflammation of the uterus while electrified athletic supporters were advertised for the treatment of male problems. Fortunately, such an amusing early history of the simple beginnings of electrical stimulation did not prevent eventual development of a variety of useful therapeutic and rehabilitative applications of electrical stimulation. Over the centuries electrical stimulation has survived as a modality in the treatment of various medical disorders with its primary application being in the rehabilitation area. Recently, a surge of new interest in electrical stimulation has been kindled by the work of a Russian sport scientist who reported remarkable muscle strength and endurance improvements in elite athletes. Yakov Kots reported his research on electric stimulation and strength improvements in 1977 at a Canadian-Soviet Exchange Symposium held at Concordia University in Montreal. Since then an explosion of new studies has been seen in both sport science and in medicine. Based upon the reported works of Kots and the present surge of new investigations, one could be misled as to the origin of electrical stimulation as a technique to increase muscle strength. As a matter of fact, electric stimulation has been used as a technique to improve muscle strength for over a century. Bigelow reported in 1894, for example, the use of electrical stimulation on a young man for the purpose of increasing muscle strength. Employing a rapidly alternating sinusoidal induced current and a dynamometer for strength testing, Bigelow reported that the total lifting capacity of a patient increased from 4328 pounds to 4639 pounds after only 25 minutes of stimulation. In 1965, Massey et al. reported on the use of an Isotron electrical stimulator that emitted a high frequency current. Interestingly enough, the frequencies used by Massey et al. and the frequencies used by Bigelow in 1894 were in the same range of frequencies reported by Kots as being the most effective in strength development. It would seem the Russian secret of high frequency electrical stimulation for strength development, then, is not a modern development at all.

Ceramic Borehole Seals for Nuclear Waste Disposal Applications

NASA Astrophysics Data System (ADS)

Lowry, B.; Coates, K.; Wohletz, K.; Dunn, S.; Patera, E.; Duguid, A.; Arnold, B.; Zyvoloski, G.; Groven, L.; Kuramyssova, K.

2015-12-01

Sealing plugs are critical features of the deep borehole system design. They serve as structural platforms to bear the weight of the backfill column, and as seals through their low fluid permeability and bond to the borehole or casing wall. High hydrostatic and lithostatic pressures, high mineral content water, and elevated temperature due to the waste packages and geothermal gradient challenge the long term performance of seal materials. Deep borehole nuclear waste disposal faces the added requirement of assuring performance for thousands of years in large boreholes, requiring very long term chemical and physical stability. A high performance plug system is being developed which capitalizes on the energy of solid phase reactions to form a ceramic plug in-situ. Thermites are a family of self-oxidized metal/oxide reactions with very high energy content and the ability to react under water. When combined with engineered additives the product exhibits attractive structural, sealing, and corrosion properties. In the initial phase of this research, exploratory and scaled tests demonstrated formulations that achieved controlled, fine grained, homogeneous, net shape plugs composed predominantly of ceramic material. Laboratory experiments produced plug cores with confined fluid permeability as low as 100 mDarcy, compressive strength as high as 70 MPa (three times the strength of conventional well cement), with the inherent corrosion resistance and service temperature of ceramic matrices. Numerical thermal and thermal/structural analyses predicted the in-situ thermal performance of the reacted plugs, showing that they cooled to ambient temperature (and design strength) within 24 to 48 hours. The current development effort is refining the reactant formulations to achieve desired performance characteristics, developing the system design and emplacement processes to be compatible with conventional well service practices, and understanding the thermal, fluid, and structural effects the plug will have on surrounding media. This paper will report on the state of the development effort and plans for a field demonstration in early 2016 in a cased well with traditional plug seal and strength measurements.

Non-elite gymnastics participation is associated with greater bone strength, muscle size, and function in pre- and early pubertal girls.

PubMed

Burt, L A; Naughton, G A; Greene, D A; Courteix, D; Ducher, G

2012-04-01

Recent reports indicate an increase in forearm fractures in children. Bone geometric properties are an important determinant of bone strength and therefore fracture risk. Participation in non-elite gymnastics appears to contribute to improving young girls' musculoskeletal health, more specifically in the upper body. The primary aim of this study was to determine the association between non-elite gymnastics participation and upper limb bone mass, geometry, and strength in addition to muscle size and function in young girls. Eighty-eight pre- and early pubertal girls (30 high-training gymnasts [HGYM, 6-16 hr/ wk], 29 low-training gymnasts [LGYM, 1-5 h r/wk] and 29 non-gymnasts [NONGYM]), aged 6-11 years were recruited. Upper limb lean mass, BMD and BMC were derived from a whole body DXA scan. Forearm volumetric BMD, bone geometry, estimated strength, and muscle CSA were determined using peripheral QCT. Upper body muscle function was investigated with muscle strength, explosive power, and muscle endurance tasks. HGYM showed greater forearm bone strength compared with NGYM, as well as greater arm lean mass, BMC, and muscle function (+5% to +103%, p < 0.05). LGYM displayed greater arm lean mass, BMC, muscle power, and endurance than NGYM (+4% to +46%, p < 0.05); however, the difference in bone strength did not reach significance. Estimated fracture risk at the distal radius, which accounted for body weight, was lower in both groups of gymnasts. Compared with NONGYM, HGYM tended to show larger skeletal differences than LGYM; yet, the two groups of gymnasts only differed for arm lean mass and muscle CSA. Non-elite gymnastics participation was associated with musculoskeletal benefits in upper limb bone geometry, strength and muscle function. Differences between the two gymnastic groups emerged for arm lean mass and muscle CSA, but not for bone strength.

Solid-state Bonding of Superplastic Aluminum Alloy 7475 Sheet

NASA Technical Reports Server (NTRS)

Byun, T. D. S.; Vastava, R. B.

1985-01-01

Experimental works were carried out to study the feasibility of solid state bonding of superplastic aluminum 7475 sheet. Amount of deformation, bonding time, surface cleaning method and intermediate layer were the process parameters investigated. Other parameters, held constant by the superplastic forming condition which is required to obtain a concurrent solid state bonding, are bonding temperature, bonding pressure and atmosphere. Bond integrity was evaluated through metallographic examination, X-ray line scan analysis, SEM fractographic analysis and lap shear tests. The early results of the development program indicated that sound solid state bonding was accomplished for this high strength 7475 alloy with significant amounts of deformation. A thin intermediate layer of the soft 5052 aluminum alloy aided in achieving a solid state bonding by reducing the required amount of plastic deformation at the interface. Bond strength was substantially increased by a post bond heat treatment.

Keratoprosthesis: preliminary results of an artificial corneal button as a full-thickness implant in the rabbit model.

PubMed

Hicks, C R; Chirila, T V; Dalton, P D; Clayton, A B; Vijayasekaran, S; Crawford, G J; Constable, I J

1996-08-01

To develop a prototype artificial cornea and evaluate it in the rabbit model. Hydrogel core-and-skirt keratoprostheses were made and were inserted as full-thickness implants covered with conjunctival flaps in the right eyes of eight rabbits. Peroperative complications related to inadequate mechanical strength led to failure in the early postoperative period in three animals, one was euthanased for an unrelated reason and the remaining four have been successful for up to 16 weeks' follow-up. Full-thickness implantation of an artificial cornea, analogous to penetrating keratoplasty, has been achieved in the rabbit model. Histological findings confirm that integration of the prosthesis with host tissue occurs. The main complications encountered in this preliminary series were related to inadequate strength of the sponge skirt of this prototype device. Work in our laboratories is now concentrated upon improving the mechanical qualities of the hydrogel skirt and on the enhancement of biointegration.

Otoacoustic emissions measured in rhesus monkeys (Macaca mulatta)

NASA Astrophysics Data System (ADS)

McFadden, Dennis; Pasanen, Edward G.; Raper, Jessica; Wallen, Kim

2003-10-01

In humans, otoacoustic emissions (OAEs) are stronger in females than in males and stronger in right ears than in left. The physiological bases for these differences are unknown, but several lines of circumstantial evidence suggest that the sex difference is attributable to androgenizing mechanisms operating during prenatal development. Specifically, it appears that exposure to high levels of androgens during prenatal development diminishes the strength of the cochlear amplifiers and thus the strength of the OAEs. Sex and ear differences in OAEs have not been well studied in species other than humans. Accordingly, click-evoked OAEs and distortion-product OAEs were measured in nine female and nine male rhesus monkeys. For CEOAEs, but less clearly for DPOAEs, females exhibited significantly stronger OAEs than males. There was no consistent ear difference for either sex for either type of OAE. In order to better study the early components of the CEOAE waveform, a nonlinear procedure [Molenaar et al., Hearing Res. 143, 197-207 (2002)] was used to collect CEOAEs along with our standard (linear) procedure. This colony also contains animals of each sex that were treated with androgenic or antiandrogenic agents during prenatal development, and OAEs are also currently being measured on those animals. [Work supported by NIDCD.

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 established the sequence of how cortical and trabecular traits co-develop during growth, which is important for identifying critical early ages to further focus on intervention studies that optimize adult bone strength.

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

ERIC Educational Resources Information Center

Glennen, Sharon

2015-01-01

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

Supporting Family Engagement in Home Visiting with the Family Map Inventories

ERIC Educational Resources Information Center

Kyzer, Angela; Whiteside-Mansell, Leanne; McKelvey, Lorraine; Swindle, Taren

2016-01-01

The purpose of this study was to examine the feasibility and usefulness of a universal screening tool, the Family Map Inventory (FMI), to assess family strengths and needs in a home visiting program. The FMI has been used successfully by center-based early childcare programs to tailor services to family needs and build on existing strengths. Home…

Development and Testing of an ISRU Soil Mechanics Vacuum Test Facility

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie E.; Wilkinson, R. Allen

2014-01-01

For extraterrestrial missions, earth based testing in relevant environments is key to successful hardware development. This is true for both early component level development and system level integration. For In-Situ Resource Utilization (ISRU) on the moon, hardware must interface with the surface material, or regolith, in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, properly conditioned bed of lunar regolith simulant. However, in earth-based granular media, such as lunar regolith simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. A mid-size chamber (3.66 m tall, 1.5 m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64 m deep by 0.914 m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types were used. Data obtained from an electric cone penetrometer can be used to determine strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off-gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5 Torr, regardless of the pump rate. The slow off-gassing of the soil at low pressure lead to long test times; a full week to reach 10(exp -5) Torr. Robotic soil manipulation would enable multiple ISRU hardware test within the same vacuum cycle. The feasibility of a robotically controlled auger and tamper was explored at vacuum conditions.

Differential neurobiological effects of expert advice on risky choice in adolescents and adults.

PubMed

Engelmann, Jan B; Moore, Sara; Monica Capra, C; Berns, Gregory S

2012-06-01

We investigated behavioral and neurobiological mechanisms by which risk-averse advice, provided by an expert, affected risky decisions across three developmental groups [early adolescents (12-14 years), late adolescents (15-17 years), adults (18+ years)]. Using cumulative prospect theory, we modeled choice behavior during a risky-choice task. Results indicate that advice had a significantly greater impact on risky choice in both adolescent groups than in adults. Using functional magnetic resonance imaging, we investigated the neural correlates of this behavioral effect. Developmental effects on correlations between brain activity and valuation parameters were obtained in regions that can be classified into (i) cognitive control regions, such as dorsolateral prefrontal cortex (DLPFC) and ventrolateral PFC; (ii) social cognition regions, such as posterior temporoparietal junction; and (iii) reward-related regions, such as ventromedial PFC (vmPFC) and ventral striatum. Within these regions, differential effects of advice on neural correlates of valuation were observed across development. Specifically, advice increased the correlation strength between brain activity and parameters reflective of safe choice options in adolescent DLPFC and decreased correlation strength between activity and parameters reflective of risky choice options in adult vmPFC. Taken together, results indicate that, across development, distinct brain systems involved in cognitive control and valuation mediate the risk-reducing effect of advice during decision making under risk via specific enhancements and reductions of the correlation strength between brain activity and valuation parameters.

Emergence of the neural network underlying phonological processing from the prereading to the emergent reading stage: A longitudinal study.

PubMed

Yu, Xi; Raney, Talia; Perdue, Meaghan V; Zuk, Jennifer; Ozernov-Palchik, Ola; Becker, Bryce L C; Raschle, Nora M; Gaab, Nadine

2018-05-01

Numerous studies have shown that phonological skills are critical for successful reading acquisition. However, how the brain network supporting phonological processing evolves and how it supports the initial course of learning to read is largely unknown. Here, for the first time, we characterized the emergence of the phonological network in 28 children over three stages (prereading, beginning reading, and emergent reading) longitudinally. Across these three time points, decreases in neural activation in the left inferior parietal cortex (LIPC) were observed during an audiovisual phonological processing task, suggesting a specialization process in response to reading instruction/experience. Furthermore, using the LIPC as the seed, a functional network consisting of the left inferior frontal, left posterior occipitotemporal, and right angular gyri was identified. The connection strength in this network co-developed with the growth of phonological skills. Moreover, children with above-average gains in phonological processing showed a significant developmental increase in connection strength in this network longitudinally, while children with below-average gains in phonological processing exhibited the opposite trajectory. Finally, the connection strength between the LIPC and the left posterior occipitotemporal cortex at the prereading level significantly predicted reading performance at the emergent reading stage. Our findings highlight the importance of the early emerging phonological network for reading development, providing direct evidence for the Interactive Specialization Theory and neurodevelopmental models of reading. © 2018 Wiley Periodicals, Inc.

Fluid placement of fixated scrubber sludge to reduce surface subsidence and to abate acid mine drainage in abandoned underground coal mines

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

Meiers, R.J.; Golden, D.; Gray, R.

1995-12-31

Indianapolis Power and Light Company (IPL) began researching the use of fluid placement techniques of the fixated scrubber sludge (FSS) to reduce surface subsidence from underground coal mines to develop an economic alternative to low strength concrete grout. Abandoned underground coal mines surround property adjacent to IPL`s coal combustion by-product (CCBP) landfill at the Petersburg Generating Station. Landfill expansion into these areas is in question because of the high potential for sinkhole subsidence to develop. Sinkholes manifesting at the surface would put the integrity of a liner or runoff pond containment structure for a CCBP disposal facility at risk. Themore » fluid placement techniques of the FSS as a subsidence abatement technology was demonstrated during an eight week period in September, October, and November 1994 at the Petersburg Generating Station. The success of this technology will be determined by the percentage of the mine void filled, strength of the FSS placed, and the overall effects on the hydrogeologic environment. The complete report for this project will be finalized in early 1996.« less

Weight training in youth-growth, maturation, and safety: an evidence-based review.

PubMed

Malina, Robert M

2006-11-01

To review the effects of resistance training programs on pre- and early-pubertal youth in the context of response, potential influence on growth and maturation, and occurrence of injury. Evidence-based review. Twenty-two reports dealing with experimental resistance training protocols, excluding isometric programs, in pre- and early-pubertal youth, were reviewed in the context of subject characteristics, training protocol, responses, and occurrence of injury. Experimental programs most often used isotonic machines and free weights, 2- and 3-day protocols, and 8- and 12-week durations, with significant improvements in muscular strength during childhood and early adolescence. Strength gains were lost during detraining. Experimental resistance training programs did not influence growth in height and weight of pre- and early-adolescent youth, and changes in estimates of body composition were variable and quite small. Only 10 studies systematically monitored injuries, and only three injuries were reported. Estimated injury rates were 0.176, 0.053, and 0.055 per 100 participant-hours in the respective programs. Experimental training protocols with weights and resistance machines and with supervision and low instructor/participant ratios are relatively safe and do not negatively impact growth and maturation of pre- and early-pubertal youth.

Long term mechanical properties of alkali activated slag

NASA Astrophysics Data System (ADS)

Zhu, J.; Zheng, W. Z.; Xu, Z. Z.; Leng, Y. F.; Qin, C. Z.

2018-01-01

This article reports a study on the microstructural and long-term mechanical properties of the alkali activated slag up to 180 days, and cement paste is studied as the comparison. The mechanical properties including compressive strength, flexural strength, axis tensile strength and splitting tensile strength are analyzed. The results showed that the alkali activated slag had higher compressive and tensile strength, Slag is activated by potassium silicate (K2SiO3) and sodium hydroxide (NaOH) solutions for attaining silicate modulus of 1 using 12 potassium silicate and 5.35% sodium hydroxide. The volume dosage of water is 35% and 42%. The results indicate that alkali activated slag is a kind of rapid hardening and early strength cementitious material with excellent long-term mechanical properties. Single row of holes block compressive strength, single-hole block compressive strength and standard solid brick compressive strength basically meet engineering requirements. The microstructures of alkali activated slag are studied by X-ray diffraction (XRD). The hydration products of alkali-activated slag are assured as hydrated calcium silicate and hydrated calcium aluminate.

Dynamic transcriptional symmetry-breaking in pre-implantation mammalian embryo development revealed by single-cell RNA-seq.

PubMed

Shi, Junchao; Chen, Qi; Li, Xin; Zheng, Xiudeng; Zhang, Ying; Qiao, Jie; Tang, Fuchou; Tao, Yi; Zhou, Qi; Duan, Enkui

2015-10-15

During mammalian pre-implantation embryo development, when the first asymmetry emerges and how it develops to direct distinct cell fates remain longstanding questions. Here, by analyzing single-blastomere transcriptome data from mouse and human pre-implantation embryos, we revealed that the initial blastomere-to-blastomere biases emerge as early as the first embryonic cleavage division, following a binomial distribution pattern. The subsequent zygotic transcriptional activation further elevated overall blastomere-to-blastomere biases during the two- to 16-cell embryo stages. The trends of transcriptional asymmetry fell into two distinct patterns: for some genes, the extent of asymmetry was minimized between blastomeres (monostable pattern), whereas other genes, including those known to be lineage specifiers, showed ever-increasing asymmetry between blastomeres (bistable pattern), supposedly controlled by negative or positive feedbacks. Moreover, our analysis supports a scenario in which opposing lineage specifiers within an early blastomere constantly compete with each other based on their relative ratio, forming an inclined 'lineage strength' that pushes the blastomere onto a predisposed, yet flexible, lineage track before morphological distinction. © 2015. Published by The Company of Biologists Ltd.

Effects of yoga, strength training and advice on back pain: a randomized controlled trial.

PubMed

Brämberg, Elisabeth Björk; Bergström, Gunnar; Jensen, Irene; Hagberg, Jan; Kwak, Lydia

2017-03-29

Among the working population, non-specific low-back pain and neck pain are one of the most common reasons for sickness absenteeism. The aim was to evaluate the effects of an early intervention of yoga - compared with strength training or evidence-based advice - on sickness absenteeism, sickness presenteeism, back and neck pain and disability among a working population. A randomized controlled trial was conducted on 159 participants with predominantly (90%) chronic back and neck pain. After screening, the participants were randomized to kundalini yoga, strength training or evidence-based advice. Primary outcome was sickness absenteeism. Secondary outcomes were sickness presenteeism, back and neck pain and disability. Self-reported questionnaires and SMS text messages were completed at baseline, 6 weeks, 6 and 12 months. The results did not indicate that kundalini yoga and strength training had any statistically significant effects on the primary outcome compared with evidence-based advice. An interaction effect was found between adherence to recommendations and sickness absenteeism, indicating larger significant effects among the adherers to kundalini yoga versus evidence-based advice: RR = 0.47 (CI 0.30; 0.74, p = 0.001), strength training versus evidence-based advice: RR = 0.60 (CI 0.38; 0.96, p = 0.032). Some significant differences were also found for the secondary outcomes to the advantage of kundalini yoga and strength training. Guided exercise in the forms of kundalini yoga or strength training does not reduce sickness absenteeism more than evidence-based advice alone. However, secondary analyses reveal that among those who pursue kundalini yoga or strength training at least two times a week, a significantly reduction in sickness absenteeism was found. Methods to increase adherence to treatment recommendations should be further developed and applied in exercise interventions. Clinicaltrials.gov NCT01653782, date of registration: June, 28, 2012, retrospectively registered.

Collaborative Initiative toward Developing River Forecasting in South America

NASA Astrophysics Data System (ADS)

Cabrera, R.

2015-12-01

In the United States, river floods have been discussed as early as 1884. Following a disastrous flooding in 1903, Congress passed legislation and river and flood services became a separate division within the U.S. Weather Bureau. The first River Forecast Center started in 1946 and today the whole country is served by thirteen River Forecast Centers. News from Latin American and Caribbean Countries often report of devastating flooding. However, river forecast services are not fully developed yet. This presentation suggests the utilization of a multinational collaborative approach toward the development of river forecasts in order to mitigate flooding in South America. The benefit of an international strategy resides in the strength created by a team of professionals with different capabilities and expertise.

A progressive 5-week exercise therapy program leads to significant improvement in knee function early after anterior cruciate ligament injury.

PubMed

Eitzen, Ingrid; Moksnes, Håvard; Snyder-Mackler, Lynn; Risberg, May Arna

2010-11-01

Prospective cohort study without a control group. Firstly, to present our 5-week progressive exercise therapy program in the early stage after anterior cruciate ligament (ACL) injury. Secondly, to evaluate changes in knee function after completion of the program for patients with ACL injury in general and also when classified as potential copers or noncopers, and, finally, to examine potential adverse events. Few studies concerning early-stage ACL rehabilitation protocols exist. Consequently, little is known about the tolerance for, and outcomes from, short-term exercise therapy programs in the early stage after injury. One-hundred patients were included in a 5-week progressive exercise therapy program, within 3 months after injury. Knee function before and after completion of the program was evaluated from isokinetic quadriceps and hamstrings muscle strength tests, 4 single-leg hop tests, 2 different self-assessment questionnaires, and a global rating of knee function. A 2-way mixed-model analysis of variance was conducted to evaluate changes from pretest to posttest for the limb symmetry index for muscle strength and single-leg hop tests, and the change in scores for the patient-reported questionnaires. In addition, absolute values and the standardized response mean for muscle strength and single-leg hop tests were calculated at pretest and posttest for the injured and uninjured limb. Adverse events during the 5-week period were recorded. The progressive 5-week exercise therapy program led to significant improvements (P<.05) in knee function from pretest to posttest both for patients classified as potential copers and noncopers. Standardized response mean values for changes in muscle strength and single-leg hop performance from pretest to posttest for the injured limb were moderate to strong (0.49-0.84), indicating the observed improvements to be clinically relevant. Adverse events occurred in 3.9% of the patients. Short-term progressive exercise therapy programs are well tolerated and should be incorporated in early-stage ACL rehabilitation, either to improve knee function before ACL reconstruction or as a first step in further nonoperative management. Therapy, level 2b.

U.S. Department of Energy Accident Resistant SiC Clad Nuclear Fuel Development

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

George W. Griffith

2011-10-01

A significant effort is being placed on silicon carbide ceramic matrix composite (SiC CMC) nuclear fuel cladding by Light Water Reactor Sustainability (LWRS) Advanced Light Water Reactor Nuclear Fuels Pathway. The intent of this work is to invest in a high-risk, high-reward technology that can be introduced in a relatively short time. The LWRS goal is to demonstrate successful advanced fuels technology that suitable for commercial development to support nuclear relicensing. Ceramic matrix composites are an established non-nuclear technology that utilizes ceramic fibers embedded in a ceramic matrix. A thin interfacial layer between the fibers and the matrix allows formore » ductile behavior. The SiC CMC has relatively high strength at high reactor accident temperatures when compared to metallic cladding. SiC also has a very low chemical reactivity and doesn't react exothermically with the reactor cooling water. The radiation behavior of SiC has also been studied extensively as structural fusion system components. The SiC CMC technology is in the early stages of development and will need to mature before confidence in the developed designs can created. The advanced SiC CMC materials do offer the potential for greatly improved safety because of their high temperature strength, chemical stability and reduced hydrogen generation.« less

Paternal Age Alters Social Development in Offspring.

PubMed

Janecka, Magdalena; Haworth, Claire M A; Ronald, Angelica; Krapohl, Eva; Happé, Francesca; Mill, Jonathan; Schalkwyk, Leonard C; Fernandes, Cathy; Reichenberg, Abraham; Rijsdijk, Frühling

2017-05-01

Advanced paternal age (APA) at conception has been linked with autism and schizophrenia in offspring, neurodevelopmental disorders that affect social functioning. The current study explored the effects of paternal age on social development in the general population. We used multilevel growth modeling to investigate APA effects on socioemotional development from early childhood until adolescence, as measured by the Strengths and Difficulties Questionnaire (SDQ) in the Twins Early Development Study (TEDS) sample. We also investigated genetic and environmental underpinnings of the paternal age effects on development, using the Additive genetics, Common environment, unique Environment (ACE) and gene-environment (GxE) models. In the general population, both very young and advanced paternal ages were associated with altered trajectory of social development (intercept: p = .01; slope: p = .03). No other behavioral domain was affected by either young or advanced age at fatherhood, suggesting specificity of paternal age effects. Increased importance of genetic factors in social development was recorded in the offspring of older but not very young fathers, suggesting distinct underpinnings of the paternal age effects at these two extremes. Our findings highlight that the APA-related deficits that lead to autism and schizophrenia are likely continuously distributed in the population. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Trajectories of Early Childhood Developmental Skills and Early Adolescent Psychotic Experiences: Findings from the ALSPAC UK Birth Cohort.

PubMed

Hameed, Mohajer A; Lingam, Raghu; Zammit, Stanley; Salvi, Giovanni; Sullivan, Sarah; Lewis, Andrew J

2017-01-01

Objective: The aim of this study was to use prospective data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine association between trajectories of early childhood developmental skills and psychotic experiences (PEs) in early adolescence. Method: This study examined data from n = 6790 children from the ALSPAC cohort who participated in a semi-structured interview to assess PEs at age 12. Child development was measured using parental report at 6, 18, 30, and 42 months of age using a questionnaire of items adapted from the Denver Developmental Screening Test - II. Latent class growth analysis was used to generate trajectories over time for measures of fine and gross motor development, social, and communication skills. Logistic regression was used to investigate associations between developmental trajectories in each of these early developmental domains and PEs at age 12. Results: The results provided evidence that decline rather than enduringly poor social (adjusted OR = 1.28, 95% CI = 1.10-1.92, p = 0.044) and communication skills (adjusted OR 1.12, 95% CI = 1.03-1.22, p = 0.010) is predictive of suspected or definite PEs in early adolescence, than those with stable and/or improving skills. Motor skills did not display the same pattern of association; although gender specific effects provided evidence that only declining pattern of fine motor skills was associated with suspected and definite PEs in males compared to females (interaction OR = 1.47, 95% CI = 1.09-1.97, p = 0.012). Conclusion: Findings suggest that decline rather than persistent impairment in social and communication skills were most predictive of PEs in early adolescence. Findings are discussed in terms of study's strengths, limitations, and clinical implications.

Trajectories of Early Childhood Developmental Skills and Early Adolescent Psychotic Experiences: Findings from the ALSPAC UK Birth Cohort

PubMed Central

Hameed, Mohajer A.; Lingam, Raghu; Zammit, Stanley; Salvi, Giovanni; Sullivan, Sarah; Lewis, Andrew J.

2018-01-01

Objective: The aim of this study was to use prospective data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine association between trajectories of early childhood developmental skills and psychotic experiences (PEs) in early adolescence. Method: This study examined data from n = 6790 children from the ALSPAC cohort who participated in a semi-structured interview to assess PEs at age 12. Child development was measured using parental report at 6, 18, 30, and 42 months of age using a questionnaire of items adapted from the Denver Developmental Screening Test – II. Latent class growth analysis was used to generate trajectories over time for measures of fine and gross motor development, social, and communication skills. Logistic regression was used to investigate associations between developmental trajectories in each of these early developmental domains and PEs at age 12. Results: The results provided evidence that decline rather than enduringly poor social (adjusted OR = 1.28, 95% CI = 1.10–1.92, p = 0.044) and communication skills (adjusted OR 1.12, 95% CI = 1.03–1.22, p = 0.010) is predictive of suspected or definite PEs in early adolescence, than those with stable and/or improving skills. Motor skills did not display the same pattern of association; although gender specific effects provided evidence that only declining pattern of fine motor skills was associated with suspected and definite PEs in males compared to females (interaction OR = 1.47, 95% CI = 1.09–1.97, p = 0.012). Conclusion: Findings suggest that decline rather than persistent impairment in social and communication skills were most predictive of PEs in early adolescence. Findings are discussed in terms of study’s strengths, limitations, and clinical implications. PMID:29375433

A comparative study on the dominant factors responsible for the weaker-than-expected El Niño event in 2014

NASA Astrophysics Data System (ADS)

Li, Jianying; Liu, Boqi; Li, Jiandong; Mao, Jiangyu

2015-10-01

Anomalous warming occurred in the equatorial central-eastern Pacific in early May 2014, attracting much attention to the possible occurrence of an extreme El Niño event that year because of its similarity to the situation in early 1997. However, the subsequent variation in sea surface temperature anomalies (SSTAs) during summer 2014 in the tropical Pacific was evidently different to that in 1997, but somewhat similar to the situation of the 1990 aborted El Niño event. Based on NCEP (National Centers for Environmental Prediction) oceanic and atmospheric reanalysis data, the physical processes responsible for the strength of El Niño events are examined by comparing the dominant factors in 2014 in terms of the preceding instability of the coupled ocean-atmosphere system and westerly wind bursts (WWBs) with those in 1997 and 1990, separately. Although the unstable ocean-atmosphere system formed over the tropical Pacific in the preceding winter of 2014, the strength of the preceding instability was relatively weak. Weak oceanic eastward-propagating downwelling Kelvin waves were forced by the weak WWBs over the equatorial western Pacific in March 2014, as in February 1990. The consequent positive upper-oceanic heat content anomalies in the spring of 2014 induced only weak positive SSTAs in the central-eastern Pacific-unfavorable for the subsequent generation of summertime WWB sequences. Moreover, the equatorial western Pacific was not cooled, indicating the absence of positive Bjerknes feedback in early summer 2014. Therefore, the development of El Niño was suspended in summer 2014.

A Comparative Study on the Dominant Factors Responsible for the Weaker-than-expected El Niño Event in 2014

NASA Astrophysics Data System (ADS)

MAO, J.; Li, J.; Liu, B.; Li, J.

2015-12-01

Anomalous warming occurred in the equatorial central-eastern Pacific in early May 2014, attracting much attention to the possible occurrence of an extreme El Niño event that year because of its similarity to the situation in early 1997. However, the subsequent variation in sea surface temperature anomalies (SSTAs) during summer 2014 in the tropical Pacific was evidently different to that in 1997, but somewhat similar to the situation of the 1990 aborted El Niño event. Based on NCEP (National Centers for Environmental Prediction) oceanic and atmospheric reanalysis data, the physical processes responsible for the strength of El Niño events are examined by comparing the dominant factors in 2014 in terms of the preceding instability of the coupled ocean-atmosphere system and westerly wind bursts (WWBs) with those in 1997 and 1990, separately. Although the unstable ocean-atmosphere system formed over the tropical Pacific in the preceding winter of 2014, the strength of the preceding instability was relatively weak. Weak oceanic eastward-propagating downwelling Kelvin waves were forced by the weak WWBs over the equatorial western Pacific in March 2014, as in February 1990. The consequent positive upper-oceanic heat content anomalies in the spring of 2014 induced only weak positive SSTAs in the central-eastern Pacific-unfavorable for the subsequent generation of summertime WWB sequences. Moreover, the equatorial western Pacific was not cooled, indicating the absence of positive Bjerknes feedback in early summer 2014. Therefore, the development of El Niño was suspended in summer 2014.

Raman spectroscopy and Raman imaging for early detection of cancer

NASA Astrophysics Data System (ADS)

Joshi, Narahari V.; Ortega, Angel; Estrela, Jose Maria

2004-06-01

Raman spectroscopy is a powerful technique as it provides fundamental information about vibrational modes of a system. Eigenvalues of these modes are very sensitive to the strength of the chemical bonds and perturbations caused by the environment, particularly charge distribution and alterations in the dipole strength of the system. All these parameters are profoundly modified during the tumor formation process nad hence Raman technique could be a unique and also a direct approach for evaluating tumor genesis at early stages. for this pupose the present investigation was carried out. We used cultured wild type and c-ras transformed NIH 3T3 fibroblast. The samples were treated with methyl alcohol solution ina conventional manner and then Raman spectra nad images were obtained by a specially developed confocal Raman microscope. The present results reveal differences between both cell types in the spectral details as well as in the morphology. Raman images are able to detect the exact site where cancer-related changes have taken place. These results clearly indicate the superiority of the present technique over conventional methods such as images obtained by X-rays or Nuclear Magnetic Resonance (NMR). Moreover, unlike other approaches, Raman images detect alterations at the submicron level rather than in the centimeter or millimeter range. Being an optical method it can be applied in vivo as a non-invasive technique potentially useful to early detection of cancer (particularly easy accessible cancers such as those of the skin and the digestive tract). The obtained resulsts suggest the great potential of Raman imaging in premature clinical diagnostic approaches.

The Brilliance of Black Boys: Cultivating School Success in the Early Grades

ERIC Educational Resources Information Center

Wright, Brian L.

2018-01-01

This much-needed book will help schools and, by extension, society to better understand and identify the promise, potential, and possibilities of Black boys. Drawing from their wealth of experience in early childhood education, the authors present an asset- and strengths-based view of educating Black boys. This positive approach enables…

A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect

PubMed Central

Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A. J.

2017-01-01

This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students (N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term. PMID:29163317

Surgery-Induced Changes and Early Recovery of Hip-Muscle Strength, Leg-Press Power, and Functional Performance after Fast-Track Total Hip Arthroplasty: A Prospective Cohort Study

PubMed Central

Holm, Bente; Thorborg, Kristian; Husted, Henrik; Kehlet, Henrik; Bandholm, Thomas

2013-01-01

Background By measuring very early changes in muscle strength and functional performance after fast-track total hip arthroplasty (THA), post-operative rehabilitation, introduced soon after surgery, can be designed to specifically target identified deficits. Objective(s) Firstly, to quantify changes (compared to pre-operative values) in hip muscle strength, leg-press power, and functional performance in the first week after THA, and secondly, to explore relationships between the muscle strength changes, and changes in hip pain, systemic inflammation, and thigh swelling. Design Prospective, cohort study. Setting Convenience sample of patients receiving a THA at Copenhagen University Hospital, Hvidovre, Denmark, between March and December 2011. Participants Thirty-five patients (65.9±7.2 years) undergoing THA. Main outcome measures Hip muscle strength, leg-press power, performance-based function, and self-reported disability were determined prior to, and 2 and 8 days after, THA (Day 2 and 8, respectively). Hip pain, thigh swelling, and C-Reactive Protein were also determined. Results Five patients were lost to follow-up. Hip muscle strength and leg press power were substantially reduced at Day 2 (range of reductions: 41–58%, P<0.001), but less pronounced at Day 8 (range of reductions: 23–31%, P<0.017). Self-reported symptoms and function (HOOS: Pain, Symptoms, and ADL) improved at Day 8 (P<0.014). Changes in hip pain, C-Reactive Protein, and thigh swelling were not related to the muscle strength and power losses. Conclusion(s) Hip muscle strength and leg-press power decreased substantially in the first week after THA – especially at Day 2 – with some recovery at Day 8. The muscle strength loss and power loss were not related to changes in hip pain, systemic inflammation, or thigh swelling. In contrast, self-reported symptoms and function improved. These data on surgery-induced changes in muscle strength may help design impairment-directed, post-operative rehabilitation to be introduced soon after surgery. Trial Registration ClinicalTrials.gov NCT01246674. PMID:23614020

Endochondral fracture healing with external fixation in the Sost knockout mouse results in earlier fibrocartilage callus removal and increased bone volume fraction and strength.

PubMed

Morse, A; Yu, N Y C; Peacock, L; Mikulec, K; Kramer, I; Kneissel, M; McDonald, M M; Little, D G

2015-02-01

Sclerostin deficiency, via genetic knockout or anti-Sclerostin antibody treatment, has been shown to cause increased bone volume, density and strength of calluses following endochondral bone healing. However, there is limited data on the effect of Sclerostin deficiency on the formative early stage of fibrocartilage (non-bony tissue) formation and removal. In this study we extensively investigate the early fibrocartilage callus. Closed tibial fractures were performed on Sost(-/-) mice and age-matched wild type (C57Bl/6J) controls and assessed at multiple early time points (7, 10 and 14days), as well as at 28days post-fracture after bony union. External fixation was utilized, avoiding internal pinning and minimizing differences in stability stiffness, a variable that has confounded previous research in this area. Normal endochondral ossification progressed in wild type and Sost(-/-) mice with equivalent volumes of fibrocartilage formed at early day 7 and day 10 time points, and bony union in both genotypes by day 28. There were no significant differences in rate of bony union; however there were significant increases in fibrocartilage removal from the Sost(-/-) fracture calluses at day 14 suggesting earlier progression of endochondral healing. Earlier bone formation was seen in Sost(-/-) calluses over wild type with greater bone volume at day 10 (221%, p<0.01). The resultant Sost(-/-) united bony calluses at day 28 had increased bone volume fraction compared to wild type calluses (24%, p<0.05), and the strength of the fractured Sost(-/-) tibiae was greater than that that of wild type fractured tibiae. In summary, bony union was not altered by Sclerostin deficiency in externally-fixed closed tibial fractures, but fibrocartilage removal was enhanced and the resultant united bony calluses had increased bone fraction and increased strength. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Weaknesses and Strengths in Assessing Early Childhood Programmes: An Assessment of an Early Childhood Spanish Trilingual Programme in Two- to Three-Year-Old Children

ERIC Educational Resources Information Center

Rivas, Sonia; Sobrino, Angel; Peralta, Felisa

2010-01-01

This article gives an account of the results from an assessment of an early childhood education programme, conducted over the course of two academic years (1999-2000 and 2000-2001), in a centre in northeastern Spain. The purpose of the assessment was to discover how a particular educational programme contributed to the short-term competency levels…

A Psychobiographical and Psycho-Political Comparison of Clinton and Trump.

PubMed

Elovitz, Paul H

2016-01-01

A comparison of the family backgrounds, childhoods, personal lives, personalities, and political views of the Republican and Democratic nominees in the 2016 presidential election. The author is a presidential psychobiographer who has been presenting and publishing on candidates and presidents since 1976. He uses his training in child development and psychoanalysis to demonstrate some of the influences of early development on the candidates’ subsequent lives and careers. The strengths and weaknesses of Hillary Clinton and Donald Trump are discussed. Included in the analysis are family background, childhood, character, coping mechanisms, temperament, role models, foreign policy, health, interpersonal relations, marriage, parenting, and religious views, as well as the appeal and obstacles to election faced by each candidate.

Withholding a Reward-driven Action: Studies of the Rise and Fall of Motor Activation and the Effect of Cognitive Depletion.

PubMed

Freeman, Scott M; Aron, Adam R

2016-02-01

Controlling an inappropriate response tendency in the face of a reward-predicting stimulus likely depends on the strength of the reward-driven activation, the strength of a putative top-down control process, and their relative timing. We developed a rewarded go/no-go paradigm to investigate such dynamics. Participants made rapid responses (on go trials) to high versus low reward-predicting stimuli and sometimes had to withhold responding (on no-go trials) in the face of the same stimuli. Behaviorally, for high versus low reward stimuli, responses were faster on go trials, and there were more errors of commission on no-go trials. We used single-pulse TMS to map out the corticospinal excitability dynamics, especially on no-go trials where control is needed. For successful no-go trials, there was an early rise in motor activation that was then sharply reduced beneath baseline. This activation-reduction pattern was more pronounced for high- versus low-reward trials and in individuals with greater motivational drive for reward. A follow-on experiment showed that, when participants were fatigued by an effortful task, they made more errors on no-go trials for high versus low reward stimuli. Together, these studies show that, when a response is inappropriate, reward-predicting stimuli induce early motor activation, followed by a top-down effortful control process (which we interpret as response suppression) that depends on the strength of the preceding activation. Our findings provide novel information about the activation-suppression dynamics during control over reward-driven actions, and they illustrate how fatigue or depletion leads to control failures in the face of reward.

Effect of Early Rehabilitation during Intensive Care Unit Stay on Functional Status: Systematic Review and Meta-Analysis

PubMed Central

Castro-Avila, Ana Cristina; Serón, Pamela; Fan, Eddy; Gaete, Mónica; Mickan, Sharon

2015-01-01

Background and Aim Critically ill survivors may have functional impairments even five years after hospital discharge. To date there are four systematic reviews suggesting a beneficial impact for mobilisation in mechanically ventilated and intensive care unit (ICU) patients, however there is limited information about the influence of timing, frequency and duration of sessions. Earlier mobilisation during ICU stay may lead to greater benefits. This study aims to determine the effect of early rehabilitation for functional status in ICU/high-dependency unit (HDU) patients. Design Systematic review and meta-analysis. MEDLINE, EMBASE, CINALH, PEDro, Cochrane Library, AMED, ISI web of science, Scielo, LILACS and several clinical trial registries were searched for randomised and non-randomised clinical trials of rehabilitation compared to usual care in adult patients admitted to an ICU/HDU. Results were screened by two independent reviewers. Primary outcome was functional status. Secondary outcomes were walking ability, muscle strength, quality of life, and healthcare utilisation. Data extraction and methodological quality assessment using the PEDro scale was performed by primary reviewer and checked by two other reviewers. The authors of relevant studies were contacted to obtain missing data. Results 5733 records were screened. Seven articles were included in the narrative synthesis and six in the meta-analysis. Early rehabilitation had no significant effect on functional status, muscle strength, quality of life, or healthcare utilisation. However, early rehabilitation led to significantly more patients walking without assistance at hospital discharge (risk ratio 1.42; 95% CI 1.17-1.72). There was a non-significant effect favouring intervention for walking distance and incidence of ICU-acquired weakness. Conclusions Early rehabilitation during ICU stay was not associated with improvements in functional status, muscle strength, quality of life or healthcare utilisation outcomes, although it seems to improve walking ability compared to usual care. Results from ongoing studies may provide more data on the potential benefits of early rehabilitation in critically ill patients. PMID:26132803

Advanced MR Imaging of the Placenta: Exploring the in utero placenta-brain connection

PubMed Central

Andescavage, Nickie Niforatos; DuPlessis, Adre; Limperopoulos, Catherine

2015-01-01

The placenta is a vital organ necessary for the healthy neurodevelopment of the fetus. Despite the known associations between placental dysfunction and neurologic impairment, there is a paucity of tools available to reliably assess in vivo placental health and function. Existing clinical tools for placental assessment remain insensitive in predicting and assessing placental well-being. Advanced MRI techniques hold significant promise for the dynamic, non-invasive, real-time assessment of placental health and identification of early placental-based disorders. In this review, we summarize the available clinical tools for placental assessment including ultrasound, Doppler, and conventional MRI. We then explore the emerging role of advanced placental MR imaging techniques for supporting the developing fetus, appraise the strengths and limitations of quantitative MRI in identifying early markers of placental dysfunction for improved pregnancy monitoring and fetal outcomes. PMID:25765905

Rigidity in Gender-Typed Behaviors in Early Childhood: A Longitudinal Study of Ethnic Minority Children

PubMed Central

Ruble, Diane; Tamis-LeMonda, Catherine; Shrout, Patrick E.

2014-01-01

A key prediction of cognitive theories of gender development concerns developmental trajectories in the relative strength or rigidity of gender typing. To examine these trajectories in early childhood, 229 children (African American, Mexican, Dominican) were followed annually from age 3 to 5 and gender-stereotypical appearance, dress-up play, toy play, and sex segregation were examined. High gender-typing was found across ethnic group, and most behaviors increased in rigidity, especially from age 3 to 4. In addressing controversy surrounding the stability and structure of gender-typing it was found that from year to year, most behaviors showed moderately stable individual differences. Behaviors were uncorrelated within age, but showed more concordance in change across time, suggesting that aspects of gender-typing are multidimensional but still show coherence. PMID:23432471

Joint attention in Down syndrome: A meta-analysis.

PubMed

Hahn, Laura J; Loveall, Susan J; Savoy, Madison T; Neumann, Allie M; Ikuta, Toshikazu

2018-07-01

Some studies have indicated that joint attention may be a relative strength in Down syndrome (DS), but other studies have not. To conduct a meta-analysis of joint attention in DS to more conclusively determine if this is a relative strength or weakness when compared to children with typical development (TD), developmental disabilities (DD), and autism spectrum disorder (ASD). Journal articles published before September 13, 2016, were identified by using the search terms "Down syndrome" and "joint attention" or "coordinating attention". Identified studies were reviewed and coded for inclusion criteria, descriptive information, and outcome variables. Eleven studies (553 participants) met inclusion criteria. Children with DS showed similar joint attention as TD children and higher joint attention than children with DD and ASD. Meta-regression revealed a significant association between age and joint attention effect sizes in the DS vs. TD contrast. Joint attention appears to not be a weakness for children with DS, but may be commensurate with developmental level. Joint attention may be a relative strength in comparison to other skills associated with the DS behavioral phenotype. Early interventions for children with DS may benefit from leveraging joint attention skills. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Properties of HPMC:PEO Extended Release Hydrophilic Matrices and their Response to Ionic Environments.

PubMed

Hu, Anran; Chen, Chen; Mantle, Michael D; Wolf, Bettina; Gladden, Lynn F; Rajabi-Siahboomi, Ali; Missaghi, Shahrzad; Mason, Laura; Melia, Colin D

2017-05-01

Investigate the extended release behaviour of compacts containing mixtures of hydrophilic HPMC and PEO in hydrating media of differing ionic strengths. The extended release behaviour of various HPMC:PEO compacts was investigated using dissolution testing, confocal microscopy and magnetic resonance imaging, with respect to polymer ratio and ionic strength of the hydrating media. Increasing HPMC content gave longer extended release times, but a greater sensitivity to high ionic dissolution environments. Increasing PEO content reduced this sensitivity. The addition of PEO to a predominantly HPMC matrix reduced release rate sensitivity to high ionic environments. Confocal microscopy of early gel layer development showed the two polymers appeared to contribute independently to gel layer structure whilst together forming a coherent and effective diffusion barrier. There was some evidence that poorly swollen HPMC particles added a tortuosity barrier to the gel layer in high ionic strength environments, resulting in prolonged extended release. MRI provides unique, non-invasive spatially resolved information from within the HPMC:PEO compacts that furthers our understanding of USP 1 and USP 4 dissolution data. Confocal microscopy and MRI data show that combinations of HPMC and PEO have advantageous extended release properties, in comparison with matrices containing a single polymer.

Assessment of isometric muscle strength and rate of torque development with hand-held dynamometry: Test-retest reliability and relationship with gait velocity after stroke.

PubMed

Mentiplay, Benjamin F; Tan, Dawn; Williams, Gavin; Adair, Brooke; Pua, Yong-Hao; Bower, Kelly J; Clark, Ross A

2018-04-27

Isometric rate of torque development examines how quickly force can be exerted and may resemble everyday task demands more closely than isometric strength. Rate of torque development may provide further insight into the relationship between muscle function and gait following stroke. Aims of this study were to examine the test-retest reliability of hand-held dynamometry to measure isometric rate of torque development following stroke, to examine associations between strength and rate of torque development, and to compare the relationships of strength and rate of torque development to gait velocity. Sixty-three post-stroke adults participated (60 years, 34 male). Gait velocity was assessed using the fast-paced 10 m walk test. Isometric strength and rate of torque development of seven lower-limb muscle groups were assessed with hand-held dynamometry. Intraclass correlation coefficients were calculated for reliability and Spearman's rho correlations were calculated for associations. Regression analyses using partial F-tests were used to compare strength and rate of torque development in their relationship with gait velocity. Good to excellent reliability was shown for strength and rate of torque development (0.82-0.97). Strong associations were found between strength and rate of torque development (0.71-0.94). Despite high correlations between strength and rate of torque development, rate of torque development failed to provide significant value to regression models that already contained strength. Assessment of isometric rate of torque development with hand-held dynamometry is reliable following stroke, however isometric strength demonstrated greater relationships with gait velocity. Further research should examine the relationship between dynamic measures of muscle strength/torque and gait after stroke. Copyright © 2018 Elsevier Ltd. All rights reserved.

Lessons from the Earth Science Women's Network (ESWN) Workshop "Defining Your Research Identity"

NASA Astrophysics Data System (ADS)

Kontak, R.; Kogan, M.; Adams, A. S.; DeBoer, A.; Hastings, M. G.; Holloway, T.; Laursen, S. L.; Marin-Spiotta, E.; Steiner, A. L.; Wiedinmyer, C.

2011-12-01

The Earth Science Women's Network (ESWN) is an international network of and for early-career women geoscientists, including graduate students, postdocs, faculty, program managers, and government, non-government and industry researchers. The mission of ESWN since 2002 is to promote career development, build community, provide informal mentoring and support, and facilitate professional collaborations, all towards making women successful in their scientific careers. With support from a National Science Foundation ADVANCE PAID grant, ESWN is meeting those goals through activities such as the workshop "Defining Your Research Identity." The overall goals of the 2011 ESWN Workshop were to help women at all career stages-but particularly early in their chosen track-to think through their personal, career and research goals, and to articulate these interests and goals in a way that reflects their professional strengths, both verbally and in writing. The focus of "Defining Your Research Identity" provided an opportunity for participants to walk away with a better sense of who they are, what they want, and how to achieve their goals by helping them identify the steps, resources and support needed. "Defining Your Research Identity," was selected as a workshop topic because the theme is relevant to all career stages. In particular, we set workshop goals of identifying personal strengths, defining a mission statement, networking with other ESWN members, and putting the newly-developed personal mission into action. Participants reported significant increases in personal motivation and support and encouragement from the network to pursue their goals, including research, writing, and applications for funding and programs.

Is a school-based physical activity intervention effective for increasing tibial bone strength in boys and girls?

PubMed

Macdonald, Heather M; Kontulainen, Saija A; Khan, Karim M; McKay, Heather A

2007-03-01

This 16-month randomized, controlled school-based study compared change in tibial bone strength between 281 boys and girls participating in a daily program of physical activity (Action Schools! BC) and 129 same-sex controls. The simple, pragmatic intervention increased distal tibia bone strength in prepubertal boys; it had no effect in early pubertal boys or pre or early pubertal girls. Numerous school-based exercise interventions have proven effective for enhancing BMC, but none have used pQCT to evaluate the effects of increased loading on bone strength during growth. Thus, our aim was to determine whether a daily program of physical activity, Action Schools! BC (AS! BC) would improve tibial bone strength in boys and girls who were pre- (Tanner stage 1) or early pubertal (Tanner stage 2 or 3) at baseline. Ten schools were randomized to intervention (INT, 7 schools) or control (CON, 3 schools). The bone-loading component of AS! BC included a daily jumping program (Bounce at the Bell) plus 15 minutes/day of classroom physical activity in addition to regular physical education. We used pQCT to compare 16-month change in bone strength index (BSI, mg2/mm4) at the distal tibia (8% site) and polar strength strain index (SSIp, mm3) at the tibial midshaft (50% site) in 281 boys and girls participating in AS! BC and 129 same-sex controls. We used a linear mixed effects model to analyze our data. Children were 10.2+/-0.6 years at baseline. Intervention boys tended to have a greater increase in BSI (+774.6 mg2/mm4; 95% CI: 672.7, 876.4) than CON boys (+650.9 mg2/mm4; 95% CI: 496.4, 805.4), but the difference was only significant in prepubertal boys (p=0.03 for group x maturity interaction). Intervention boys also tended to have a greater increase in SSIp (+198.6 mm3; 95% CI: 182.9, 214.3) than CON boys (+177.1 mm3; 95% CI: 153.5, 200.7). Change in BSI and SSIp was similar between CON and INT girls. Our findings suggest that a simple, pragmatic program of daily activity enhances bone strength at the distal tibia in prepubertal boys. The precise exercise prescription needed to elicit a similar response in more mature boys or in girls might be best addressed in a dose-response trial.

Explosive Strength of the Knee Extensors: The Influence of Criterion Trial Detection Methodology on Measurement Reproducibility.

PubMed

Dirnberger, Johannes; Wiesinger, Hans-Peter; Wiemer, Nicolas; Kösters, Alexander; Müller, Erich

2016-04-01

The present study was conducted to assess test-retest reproducibility of explosive strength measurements during single-joint isometric knee extension using the IsoMed 2000 dynamometer. Thirty-one physically active male subjects (mean age: 23.7 years) were measured on two occasions separated by 48-72 h. The intraclass correlation coefficient (ICC 2,1) and the coefficient of variation (CV) were calculated for (i) maximum torque (MVC), (ii) the peak rate of torque development (RTD peak ) as well as for (iii) the average rate of torque development (RTD) and the impulse taken at several predefined time intervals (0-30 to 0-300 ms); thereby explosive strength variables were derived in two conceptually different versions: on the one hand from the MVC-trial (version I), on the other hand from the trial showing the RTD peak (version II). High ICC-values (0.80-0.99) and acceptable CV-values (1.9-8.7%) could be found for MVC as well as for the RTD and the impulse taken at time intervals of ≥100 ms, regardless of whether version I or II was used. In contrast, measurements of the RTD peak as well as the RTD and the impulse taken during the very early contraction phase (i.e. RTD/impulse 0-30ms and RTD/impulse 0-50ms ) showed clearly weaker reproducibility results (ICC: 0.53-0.84; CV: 7.3-16.4%) and gave rise to considerable doubts as to clinical usefulness, especially when derived using version I. However, if there is a need to measure explosive strength for earlier time intervals in practice, it is, in view of stronger reproducibility results, recommended to concentrate on measures derived from version II, which is based on the RTD peak -trial.

Evolution of hydromagnetic turbulence from the electroweak phase transition

NASA Astrophysics Data System (ADS)

Brandenburg, Axel; Kahniashvili, Tina; Mandal, Sayan; Pol, Alberto Roper; Tevzadze, Alexander G.; Vachaspati, Tanmay

2017-12-01

We present new simulations of decaying hydromagnetic turbulence for a relativistic equation of state relevant to the early Universe. We compare helical and nonhelical cases either with kinetically or magnetically dominated initial fields. Both kinetic and magnetic initial helicities lead to maximally helical magnetic fields after some time, but with different temporal decay laws. Both are relevant to the early Universe, although no mechanisms have yet been identified that produce magnetic helicity with strengths comparable to the big bang nucleosynthesis limit at scales comparable to the Hubble horizon at the electroweak phase transition. Nonhelical magnetically dominated fields could still produce picoGauss magnetic fields under most optimistic conditions. Only helical magnetic fields can potentially have nanoGauss strengths at scales up to 30 kpc today.

Effects of Asymptomatic Rotator Cuff Pathology On In-Vivo Shoulder Motion and Clinical Outcomes

PubMed Central

Baumer, Timothy G.; Dischler, Jack; Mende, Veronica; Zauel, Roger; van Holsbeeck, Marnix; Siegal, Daniel S.; Divine, George; Moutzouros, Vasilios; Bey, Michael J.

2017-01-01

Background The incidence of asymptomatic rotator cuff tears has been reported to range from 15–39%, but the influence of asymptomatic rotator cuff pathology on shoulder function is not well understood. The objective of this study was to assess the effects of asymptomatic rotator cuff pathology on shoulder kinematics, strength, and patient-reported outcomes. Methods 46 asymptomatic volunteers (age: 60.3±7.5) with normal shoulder function underwent a clinical ultrasound exam to document the condition of their rotator cuff. The ultrasound imaging identified subjects as healthy (n=14) or pathologic (n=32). Shoulder motion was measured with a biplane x-ray imaging system, strength was assessed with a Biodex, and patient-reported outcomes were assessed using the Western Ontario Rotator Cuff Index and VAS pain scores. Results Compared to healthy subjects, the subjects with rotator cuff pathology had significantly less abduction (p=0.050) and elevation (p=0.041) strength, their humerus was positioned more inferiorly on the glenoid (p=0.018), and the glenohumeral contact path length was longer (p=0.007). No significant differences were detected in terms of WORC, VAS, ROM, or acromiohumeral distance. Discussion The differences observed between the healthy subjects and subjects with asymptomatic rotator cuff pathology lend insight into the changes in joint mechanics, shoulder strength, and conventional clinical outcomes associated with the early stages of rotator cuff pathology. Furthermore, these findings suggest a plausible mechanical progression of kinematic and strength changes associated with the development of rotator cuff pathology. Level of evidence Basic Science Study, Kinesiology PMID:28131679

"En Confianza": Co-Constructing Professional Strength and Voice with Latina Early Childhood Educators

ERIC Educational Resources Information Center

Ordonez-Jasis, Rosario; Flores, Susana Y.; Jasis, Pablo M.

2010-01-01

It is well documented in the literature that early pre-K reading experiences prepare children for the benefits of formal literacy instruction in the later grades. This is particularly true for young children from nonmainstream backgrounds. The objective of this article is to share the findings of a 4-year qualitative study investigating the…

Longitudinal Theory of Mind (ToM) Development From Preschool to Adolescence With and Without ToM Delay.

PubMed

Peterson, Candida C; Wellman, Henry M

2018-04-16

Longitudinal tracking of 107 three- to-thirteen-year-olds in a cross-sequential design showed a 6-step theory of mind (ToM) sequence identified by a few past cross-sectional studies validly depicted longitudinal ToM development from early to middle childhood for typically developing (TD) children and those with ToM delays owing to deafness or autism. Substantively, all groups showed ToM progress throughout middle childhood. Atypical development was more extended and began and ended at lower levels than for TD children. Yet most children in all groups progressed over the study's mean 1.5 years. Findings help resolve theoretical debates about ToM development for children with and without delay and gain strength and weight via their applicability to three disparate groups varying in ToM timing and sequencing. © 2018 Society for Research in Child Development.

Structural and biomechanical characteristics after early mobilization in an Achilles tendon rupture model: operative versus nonoperative treatment.

PubMed

Krapf, Daniel; Kaipel, Martin; Majewski, Martin

2012-09-01

Acute Achilles tendon ruptures are common sports injuries; however, treatment remains a clinical challenge. Studies show a superior effect of early mobilization and full weight bearing on tendon healing and clinical outcome; however, few data exist on structural and biomechanical characteristics in the early healing phase. This study investigated the histological and biomechanical characteristics of early mobilization and full weight bearing in an Achilles tendon rupture model. Eighty rats underwent dissection of a hindpaw Achilles tendon; 40 rats were treated conservatively and 40 underwent open repair of the transected Achilles tendon by suturing. Early mobilization and full weight bearing were allowed in both groups. At 1, 2, 4, and 8 weeks after tenotomy, tensile strength, stiffness, thickness, tissue characteristics (histological analysis), and length were determined. Dissected Achilles tendons healed in all animals during full weight-bearing early mobilization. One and 2 weeks after tenotomy, rats in the operative group showed increased tensile strength and stiffness compared with the nonoperative group. Repair-site diameters were increased at 1, 2, and 8 weeks after tenotomy. Tendon length was decreased in the operative group throughout observation, whereas the nonoperative group showed increased structural characteristics on the cellular level and a more homogeneous collagen distribution. Surgical treatment of dissected rat Achilles tendons showed superior biomechanical characteristics within the first 2 weeks. Conservative treatment resulted in superior histological findings but significant lengthening of the tendon in the early healing phase (weeks 1-8). Copyright 2012, SLACK Incorporated.

Hand Strength, Handwriting, and Functional Skills in Children With Autism.

PubMed

Alaniz, Michele L; Galit, Eleanor; Necesito, Corina Isabel; Rosario, Emily R

2015-01-01

To establish hand strength development trends in children with autism and to investigate correlations between grip and pinch strength, components of handwriting, and functional activities in children with and without autism. Fifty-one children were divided into two groups: typically developing children and children on the autism spectrum. Each child completed testing for pinch and grip strength, handwriting legibility, pencil control, and independence in functional activities. The children with autism followed the same strength development trends as the typically developing children. Grip strength correlated with pencil control in both groups and with handwriting legibility in the typically developing children but not in the children with autism. Grip and pinch strength correlated with independence with functional activities in both groups. This study provides evidence that grip and pinch strength are important components in developing pencil control, handwriting legibility, and independence with functional fine motor tasks. Copyright © 2015 by the American Occupational Therapy Association, Inc.

Effectiveness of acute in-hospital physiotherapy with knee-extension strength training in reducing strength deficits in patients with a hip fracture: A randomised controlled trial

PubMed Central

2017-01-01

Question Is acute in-hospital physiotherapy with additional progressive knee-extension strength training (ST) of the fractured limb more effective in reducing knee-extension strength deficit at follow-up compared to physiotherapy without strength training in patients with a hip fracture? Design Assessor blinded, randomised controlled trial with intention-to-treat analysis. Participants 90 patients with a hip fracture admitted to an acute orthopaedic Hip Fracture Unit at a university hospital between October 2013 and May 2015. Intervention Daily physiotherapy with or without progressive knee-extension strength training (10RM), 3 x 10 repetitions, of the fractured limb using ankle weight cuffs conducted by ward physical therapists during hospital stay. Outcome measures Primary outcome was the change in maximal isometric knee-extension strength in the fractured limb in percentage of the non-fractured limb from inclusion to postoperative day 10 or discharge (follow-up). Secondary outcome was Timed Up and Go test measured early after surgery and at follow-up. Results In the intention-to-treat analysis of between-group differences, the primary outcome improved 8.1% (95% CI -2.3; 18.4) by additional strength training from baseline to follow-up. In the per-protocol analysis of non-missing data, significant between-group improvements by 10.5% (95% CI 0.3; 20.7) were found in favour of additional ST. No significant between-group differences were found in any secondary outcome. Conclusion Physiotherapy with addition of 5 sessions of ST yielded no additional improvements compared to physiotherapy without strength training in reducing the knee-extension strength deficit at follow-up in patients with a hip fracture. It is debatable whether larger improvements than the observed 8–10% can be expected given that only five exercise sessions, on average, were completed. In fragile patients with a hip fracture in the acute phase, where the ability to participate in functional exercise is compromised, we still consider early strength training a possibility to improve outcomes of clinical importance, given the results of the per-protocol analysis. The present data provides an important basis and call for future investigations including longer term interventions. Trial registration Clinicaltrials.gov NCT00848913 PMID:28662153

Supervised toothbrushing programs in primary schools and early childhood settings: A scoping review.

PubMed

Dickson-Swift, V; Kenny, A; Gussy, M; de Silva, A M; Farmer, J; Bracksley-O'Grady, S

2017-12-01

In this article we report the findings of a scoping review that aimed to identify and summarise the range of programs and guidelines available for toothbrushing programs in schools and early childhood settings. Dental caries is one of the most common preventable diseases affecting children worldwide. Untreated caries can impact on child health and wellbeing, development, socialisation and school attendance. Supervised toothbrushing programs in schools and other early childhood settings can be effective in improving the oral health of young children. There is limited understanding of the salient issues to consider when developing such programs or how they are best implemented in real world settings. A scoping review methodology was utilised to provide a summary of the guidelines and programs available. Key search terms were developed, mapped and utilised to identify guidelines and programs across 6 databases and key search engines. We located 26 programs and guidelines that met the inclusion and exclusion criteria for the review. These were collated and summarised across key countries and critical aspects of program development and implementation were identified. Toothbrush type and storage, toothpaste strength and method of dispensing, toothbrush storage, staff training and parental consent are key considerations that varied widely. Guidelines for supervised toothbrushing programs vary within and across countries due to differences in water fluoridation and availability of low fluoride toothpastes. The results of this review provide critical information to be considered when establishing and implementing toothbrushing programs in these settings. Copyright© 2017 Dennis Barber Ltd.

Test Standard Developed for Determining the Slow Crack Growth of Advanced Ceramics at Ambient Temperature

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Salem, Jonathan A.

1998-01-01

The service life of structural ceramic components is often limited by the process of slow crack growth. Therefore, it is important to develop an appropriate testing methodology for accurately determining the slow crack growth design parameters necessary for component life prediction. In addition, an appropriate test methodology can be used to determine the influences of component processing variables and composition on the slow crack growth and strength behavior of newly developed materials, thus allowing the component process to be tailored and optimized to specific needs. At the NASA Lewis Research Center, work to develop a standard test method to determine the slow crack growth parameters of advanced ceramics was initiated by the authors in early 1994 in the C 28 (Advanced Ceramics) committee of the American Society for Testing and Materials (ASTM). After about 2 years of required balloting, the draft written by the authors was approved and established as a new ASTM test standard: ASTM C 1368-97, Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress-Rate Flexural Testing at Ambient Temperature. Briefly, the test method uses constant stress-rate testing to determine strengths as a function of stress rate at ambient temperature. Strengths are measured in a routine manner at four or more stress rates by applying constant displacement or loading rates. The slow crack growth parameters required for design are then estimated from a relationship between strength and stress rate. This new standard will be published in the Annual Book of ASTM Standards, Vol. 15.01, in 1998. Currently, a companion draft ASTM standard for determination of the slow crack growth parameters of advanced ceramics at elevated temperatures is being prepared by the authors and will be presented to the committee by the middle of 1998. Consequently, Lewis will maintain an active leadership role in advanced ceramics standardization within ASTM. In addition, the authors have been and are involved with several international standardization organizations including the Versailles Project on Advanced Materials and Standards (VAMAS), the International Energy Agency (IEA), and the International Organization for Standardization (ISO). The associated standardization activities involve fracture toughness, strength, elastic modulus, and the machining of advanced ceramics.

Compressive Strength and Indentation Damage in Ceramic Materials.

DTIC Science & Technology

1978-05-31

The extent of the plastically deformed region associated with indentation in silicon carbide is determined by means of selected area electron...microfracture mechanisms responsible for the temperature-sensitive compressive strength behavior of polycrystalline Al2O3 and alpha-SiC. It is determined ...that the early stages of damage can be related to the presence or absence of microplasticity , depending upon the ceramic. Further, local plastic flow in

Empowering Head Start African American and Latino Families: Promoting Strengths-Based Parenting Characteristics through Child Parent Relationship Training--An Evidence-Based Group Parenting Program

ERIC Educational Resources Information Center

Sheely-Moore, Angela I.; Ceballos, Peggy L.

2011-01-01

With the tendency of low-income African American and Latino children identified at-risk for school readiness and school success compared to their early-childhood counterparts, Head Start personnel are challenged to examine the role of family strengths in the promotion of academic success for these populations. This article provides a rationale for…

Aerobic fitness, muscular strength and obesity in relation to risk of heart failure.

PubMed

Crump, Casey; Sundquist, Jan; Winkleby, Marilyn A; Sundquist, Kristina

2017-11-01

Low physical fitness and obesity have been associated with higher risk of developing heart failure (HF), but their interactive effects are unknown. Elucidation of interactions among these common modifiable factors may help facilitate more effective primary prevention. We conducted a national cohort study to examine the interactive effects of aerobic fitness, muscular strength and body mass index (BMI) among 1 330 610 military conscripts in Sweden during 1969-1997 (97%-98% of all 18-year-old men) on risk of HF identified from inpatient and outpatient diagnoses through 2012 (maximum age 62 years). There were 11 711 men diagnosed with HF in 37.8 million person-years of follow-up. Low aerobic fitness, low muscular strength and obesity were independently associated with higher risk of HF, after adjusting for each other, socioeconomic factors, other chronic diseases and family history of HF. The combination of low aerobic fitness and low muscular strength (lowest vs highest tertiles) was associated with a 1.7-fold risk of HF (95% CI 1.6 to 1.9; p<0.001; incidence rates per 100 000 person-years, 43.2 vs 10.8). These factors had positive additive and multiplicative interactions (p<0.001) and were associated with increased risk of HF even among men with normal BMI. Low aerobic fitness, low muscular strength and obesity at the age of 18 years were independently associated with higher risk of HF in adulthood, with interactive effects between aerobic fitness and muscular strength. These findings suggest that early-life interventions may help reduce the long-term risk of HF and should include both aerobic fitness and muscular strength, even among persons with normal BMI. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Correlation of Titleist Performance Institute (TPI) level 1 movement screens and golf swing faults.

PubMed

Gulgin, Heather R; Schulte, Brian C; Crawley, Amy A

2014-02-01

Although some research in the past has examined how physical limitations in strength or flexibility affect a golfer's performance, the performance outcome most measured was driving distance. Currently, there are no data that have examined the relationship between selected strength and flexibility variables and golf swing faults. The purpose of this study was to examine the relationship between Titleist Performance Institute (TPI) level 1 movement screen variables and 14 common golf swing faults. Thirty-six male and female golfers (mean age, 25.4 ± 9.9 years; height, 175.9 ± 16.2 cm; mass, 76.2 ± 14.6 kg; handicap, 14.2 ± 10.4) participated. Twelve physical tests of strength, flexibility, and balance were assessed using the TPI level 1 golf fitness screening tool. Golfers then hit 4 golf shots (with a 5-iron) while being videoed, and those were then analyzed for 14 different golf swing faults (using V1Pro software). Three significant associations between a physical limitation and a particular golf swing fault were found: toe touch and early hip extension (p = 0.015), bridge on right side with both early hip extension (p = 0.050), and loss of posture (p = 0.028). In addition, an odds ratio showed that when a golfer could not overhead deep squat or single leg balance on left side, they were 2-3 times more likely to exhibit a early hip extension, loss of posture, or slide during the golf swing, as compared with those who could perform a correct overhead deep squat. Based on our findings, it is important for the golf fitness professional to particularly address a golfer's core strength, balance, and hamstring flexibility to help avoid common golf swing faults, which affect a golfer's ball striking ability and ultimately their performance.

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

Bhattacharya, Arunodaya; Meslin, Estelle; Henry, Jean

Effect of helium on void swelling was studied in high-purity α-iron, irradiated using energetic self-ions to 157 displacements per atom (dpa) at 773 K, with and without helium co-implantation up to 17 atomic parts-per-million (appm) He/dpa. Helium is known to enhance cavity formation in metals in irradiation environments, leading to early void swelling onset. In this study, microstructure characterization by transmission electron microscopy revealed compelling evidence of dramatic swelling reduction by helium co-implantation, achieved primarily by cavity size reduction. In conclusion, a comprehensive understanding of helium induced cavity microstructure development is discussed using sink strength ratios of dislocations and cavities.

THE FUEL ELEMENT GRAPHITE. Project DRAGON.

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

Graham, L.W.; Price, M.S.T.

1963-01-15

The main requirements of a fuel element graphite for reactors based on the Dragon concept are low transmission coefficient for fission products, dimensional stability under service conditions, high strength, high thermal conductivity, high purity, and high resistance to oxidation. Since conclusions reached in early 1960, a considerable amount of information has accumulated concerning the likely behaviour of graphites in high temperature reactor systems, particularly data on dimensional stability under irradiation. The influence of this new knowledge on the development of fuel element graphite with the Dragon Project is discussed in detail in the final section of this paper.

Developmental programming: the role of growth hormone.

PubMed

Oberbauer, Anita M

2015-01-01

Developmental programming of the fetus has consequences for physiologic responses in the offspring as an adult and, more recently, is implicated in the expression of altered phenotypes of future generations. Some phenotypes, such as fertility, bone strength, and adiposity are highly relevant to food animal production and in utero factors that impinge on those traits are vital to understand. A key systemic regulatory hormone is growth hormone (GH), which has a developmental role in virtually all tissues and organs. This review catalogs the impact of GH on tissue programming and how perturbations early in development influence GH function.

GALEX studies on UV properties of Nearby Early-type Galaxies

NASA Astrophysics Data System (ADS)

Rhee, J.; Rich, R. M.; Sohn, Y.-J.; Lee, Y.-W.; Gil de Paz, A.; Deharveng, J.-M.; Donas, J.; Boselli, A.; Rey, S.-C.; Yi, S. K.; GALEX Team

2005-12-01

We present the results of surface photometry on the far-UV (FUV) and near-UV (NUV) images of 23 nearby elliptical galaxies and spiral bulges taken from the GALEX (Galaxy Evolution Explorer). Surface brightness profiles of most galaxies are consistent with de Vaucouleurs' r1/4 law except for some cases more consistent with exponential profiles. We analyze the radial profiles of UV color, (FUV - NUV), and Mg2 line index to investigate a correlation between the gradients of UV color and metal abundance for early-type galaxies. UV color gradients are calculated by applying least square fitting to UV color profile up to effective radius, while Mg2 line strength gradients are compiled for 12 galaxies from previous works. For the 12 early-type galaxies, we find that UV color profiles have a trend to become bluer inward and there is a weak correlation between the gradients of UV color and Mg2 line strength in the sense that galaxies with larger UV color gradients tend to have stronger metal abundance gradients. We also explore the properties of the GALEX-measured ultraviolet rising flux in 96 nearby elliptical galaxies, as a function Lick Mg2 index and velocity dispersion. We include 36 galaxies in the Virgo cluster from the sample of Boselli et al (2005). We find no correlation between the Mg2 index, and log σ and FUV-r. This confirms the findings of Rich et al (2005) for a sample of GALEX/SDSS quiescent early-type galaxies. This is true both for the integrated light, and for nuclear colors. We find a weak correlation between Mg2 and FUV-NUV. We gratefully acknowledge NASA's support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the Centre National d'Etudes Spatiales of France and the Korean Ministry of Science and Technology.

The Relationship between Motor, Imitation, and Early Social Communication Skills in Children with Autism.

PubMed

Dadgar, Hooshang; Alaghband Rad, Javad; Soleymani, Zahra; Khorammi, Anahita; McCleery, Joe; Maroufizadeh, Saman

2017-10-01

Objective: Development of early social skills in children is a complex process. To understand this process, it is important to assess how strengths or weaknesses in other developmental domains may be affected by these skills. The present study aimed at investigating the association of motor skills and imitation ability with early social communication skills in children with autism spectrum disorder (ASD). Method: In this study, 20 children with ASD aged 3 to 5 years (M = 4.05, SD = 0.55) participated. All children were diagnosed as ASD based on the DSM-V criteria by an independent child psychiatrist. Additionally, Autism Diagnostic interview-Revised was used for subsequent diagnostic confirmation. Children were tested with Test of Gross Motor Development (TGMD-2), the Motor Imitation Scale (MIS), and the Early Social Communication Scales (ESCS). All examinations were videotaped for subsequent scoring. The relationship between these skills was estimated by Pearson correlation coefficient. Results: A significant and strong correlation was obtained between TGMD total score and imitation total score (r =.776; p <0.001). However, the relationship between MIS subscales and TGMD-2 locomotor subtest scores was not significant (P>0.05). A significant correlation was found between MIS and TGMD total scores with Initiating Joint Attention and Responding to Joint Attention (p≤0/025) as ESCS subscales. But MIS and TGMD total scores were not correlated with social interaction and responding to behavioral requests subscales. Conclusion: The results of the present study showed that indicated both imitation ability and motor function have an association with each other and with early social communication skills.

The Relationship between Motor, Imitation, and Early Social Communication Skills in Children with Autism

PubMed Central

Dadgar, Hooshang; Alaghband Rad, Javad; Soleymani, Zahra; Khorammi, Anahita; McCleery, Joe; Maroufizadeh, Saman

2017-01-01

Objective: Development of early social skills in children is a complex process. To understand this process, it is important to assess how strengths or weaknesses in other developmental domains may be affected by these skills. The present study aimed at investigating the association of motor skills and imitation ability with early social communication skills in children with autism spectrum disorder (ASD). Method: In this study, 20 children with ASD aged 3 to 5 years (M = 4.05, SD = 0.55) participated. All children were diagnosed as ASD based on the DSM-V criteria by an independent child psychiatrist. Additionally, Autism Diagnostic interview-Revised was used for subsequent diagnostic confirmation. Children were tested with Test of Gross Motor Development (TGMD-2), the Motor Imitation Scale (MIS), and the Early Social Communication Scales (ESCS). All examinations were videotaped for subsequent scoring. The relationship between these skills was estimated by Pearson correlation coefficient. Results: A significant and strong correlation was obtained between TGMD total score and imitation total score (r =.776; p <0.001). However, the relationship between MIS subscales and TGMD-2 locomotor subtest scores was not significant (P>0.05). A significant correlation was found between MIS and TGMD total scores with Initiating Joint Attention and Responding to Joint Attention (p≤0/025) as ESCS subscales. But MIS and TGMD total scores were not correlated with social interaction and responding to behavioral requests subscales. Conclusion: The results of the present study showed that indicated both imitation ability and motor function have an association with each other and with early social communication skills. PMID:29472949

The influence of using accelerator addition on High strength self-compacting concrete (HSSCC) in case of enhancement early compressive strength and filling ability parameters

NASA Astrophysics Data System (ADS)

Wibowo; Fadillah, Y.

2018-03-01

Efficiency in a construction works is a very important thing. Concrete with ease of workmanship and rapid achievement of service strength will to determine the level of efficiency. In this research, we studied the optimization of accelerator usage in achieving performance on compressive strength of concrete in function of time. The addition of variation of 0.3% - 2.3% to the weight of cement gives a positive impact of the rapid achievement of hardened concrete, however the speed of increasing of concrete strength achievement in term of time influence present increasing value of filling ability parameter of self-compacting concrete. The right composition of accelerator aligned with range of the values standard of filling ability parameters of HSSCC will be an advantage guidance for producers in the ready-mix concrete industry.

The changing landscape of functional brain networks for face processing in typical development.

PubMed

Joseph, Jane E; Swearingen, Joshua E; Clark, Jonathan D; Benca, Chelsie E; Collins, Heather R; Corbly, Christine R; Gathers, Ann D; Bhatt, Ramesh S

2012-11-15

Greater expertise for faces in adults than in children may be achieved by a dynamic interplay of functional segregation and integration of brain regions throughout development. The present study examined developmental changes in face network functional connectivity in children (5-12 years) and adults (18-43 years) during face-viewing using a graph-theory approach. A face-specific developmental change involved connectivity of the right occipital face area. During childhood, this node increased in strength and within-module clustering based on positive connectivity. These changes reflect an important role of the ROFA in segregation of function during childhood. In addition, strength and diversity of connections within a module that included primary visual areas (left and right calcarine) and limbic regions (left hippocampus and right inferior orbitofrontal cortex) increased from childhood to adulthood, reflecting increased visuo-limbic integration. This integration was pronounced for faces but also emerged for natural objects. Taken together, the primary face-specific developmental changes involved segregation of a posterior visual module during childhood, possibly implicated in early stage perceptual face processing, and greater integration of visuo-limbic connections from childhood to adulthood, which may reflect processing related to development of perceptual expertise for individuation of faces and other visually homogenous categories. Copyright © 2012 Elsevier Inc. All rights reserved.

Understanding frailty in the geriatric population.

PubMed

Wick, Jeannette Y

2011-09-01

Clinicians who work with the frail elderly know what frailty looks like, but until recently, they have had no science-based definition of this condition. Frailty is classified as a medical syndrome, and Fried et al. were among the first to standardize the definition of frailty as a distinct syndrome with biologic underpinnings. Their definition describes a clinical phenotype of decreased reserve and resistance to stressors, with clinical manifestations of a mutually exacerbating cycle of negative energy balance, sarcopenia, diminished strength, and exertion intolerance. Age is no longer considered a defining characteristic, although frailty is still considered primarily a geriatric problem. Approximately two-thirds of affected individuals enter frailty in a slow, progressive way, while one-third become frail cataclysmically. Weakness is a common early sign, and exhaustion and weight loss are often late manifestations. Observing early behavioral changes before frailty develops could provide insight into its development and suggest early interventions. Since frailty is clearly associated with adverse outcomes, a healthy, active lifestyle is the cornerstone of prevention, and many researchers suggest that resistance training can reverse some muscle loss and improve functioning. When the health care team proposes any change in care, including a new medication, it should be prepared to describe how the intervention may affect cognition, memory, energy, or function.

Deep Friction Massage Versus Steroid Injection in the Treatment of Lateral Epicondylitis.

PubMed

Yi, Rosemary; Bratchenko, Walter W; Tan, Virak

2018-01-01

The aim of the study was to determine the efficacy of deep friction massage in the treatment of lateral epicondylitis by comparing outcomes with a control group treated with splinting and therapy and with an experimental group receiving a local steroid injection. A randomized clinical trial was conducted to compare outcomes after recruitment of consecutive patients presenting with lateral epicondylitis. Patients were randomized to receive one of 3 treatments: group 1: splinting and stretching, group 2: a cortisone injection, or group 3: a lidocaine injection with deep friction massage. Pretreatment and posttreatment parameters of visual analog scale (VAS) pain ratings, Disabilities of the Arm, Shoulder and Hand (DASH) scores, and grip strength were measured. Outcomes were measured at early follow-up (6-12 weeks) and at 6-month follow-up. There was a significant improvement in VAS pain score in all treatment groups at early follow-up. DASH score and grip strength improved in the cortisone injection group and the deep friction massage group at early follow-up; these parameters did not improve in the splinting and stretching group. At 6-month follow-up, only patients in the deep friction massage group demonstrated a significant improvement in all outcome measures, including VAS pain score, DASH score, and grip strength. Deep friction massage is an effective treatment for lateral epicondylitis and can be used in patients who have failed other nonoperative treatments, including cortisone injection.

Retention of primitive reflexes and delayed motor development in very low birth weight infants.

PubMed

Marquis, P J; Ruiz, N A; Lundy, M S; Dillard, R G

1984-06-01

Primitive reflexes and motor development were evaluated in 127 very low birth weight (VLBW) infants (birth weight less than 1501 grams) at four months corrected age. The asymmetrical tonic neck reflex, tonic labyrinth reflex, and Moro reflex were assessed for each child. The ability of each child to reach (obtain a red ring) and roll were observed. The child's performance on the gross motor scale of the Denver Development Screening Test was recorded. Thirty-seven term infants were administered identical evaluations at four months of age. The VLBW infants retained stronger primitive reflexes and exhibited a significantly higher incidence of motor delays than term infants. Significant correlations existed between the strength of the primitive reflexes and early motor development for VLBW infants. This study confirms a high incidence of motor delays among VLBW infants and demonstrates a clear association between retained primitive reflexes and delayed motor development in VLBW infants.

Early Exercise Rehabilitation of Muscle Weakness in Acute Respiratory Failure Patients

PubMed Central

Berry, Michael J.; Morris, Peter E.

2013-01-01

Acute Respiratory Failure patients experience significant muscle weakness which contributes to prolonged hospitalization and functional impairments post-hospital discharge. Based on our previous work, we hypothesize that an exercise intervention initiated early in the intensive care unit aimed at improving skeletal muscle strength could decrease hospital stay and attenuate the deconditioning and skeletal muscle weakness experienced by these patients. Summary Early exercise has the potential to decrease hospital length of stay and improve function in Acute Respiratory Failure patients. PMID:23873130

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

PubMed

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

2014-12-01

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

Gender Differences in the Relationship between Oral Communicative Competence and Peer Rejection: An Explorative Study in Early Childhood Education

ERIC Educational Resources Information Center

van der Wilt, Femke; van Kruistum, Claudia; van der Veen, Chiel; van Oers, Bert

2016-01-01

This study investigated gender differences in the relationship between oral communicative competence and peer rejection in early childhood education. It was hypothesized that children with poorer oral communicative competence would be rejected by their peers more frequently and that the strength of this relationship would differ for boys and…

To Be the Best That We Can Be: A Self-Study Guide for Early Childhood Special Education Programs and Staff.

ERIC Educational Resources Information Center

Gaetz, Joan; And Others

This self-study guide facilitates evaluation of early childhood special education programs by providing a tool for identifying both strengths and areas for improvement. Steps are outlined for completing a program self-study. Then forms are offered for assessing the quality of specific program areas. A section on necessary relationships examines…

Personality and performance are affected by age and early life parameters in a small primate.

PubMed

Zablocki-Thomas, Pauline B; Herrel, Anthony; Hardy, Isabelle; Rabardel, Lucile; Perret, Martine; Aujard, Fabienne; Pouydebat, Emmanuelle

2018-05-01

A whole suite of parameters is likely to influence the behavior and performance of individuals as adults, including correlations between phenotypic traits or an individual's developmental context. Here, we ask the question whether behavior and physical performance traits are correlated and how early life parameters such as birth weight, litter size, and growth can influence these traits as measured during adulthood. We studied 486 captive gray mouse lemurs ( Microcebus murinus ) and measured two behavioral traits and two performance traits potentially involved in two functions: exploration behavior with pull strength and agitation score with bite force. We checked for the existence of behavioral consistency in behaviors and explored correlations between behavior, performance, morphology. We analyzed the effect of birth weight, growth, and litter size, while controlling for age, sex, and body weight. Behavior and performance were not correlated with one another, but were both influenced by age. Growth rate had a positive effect on adult morphology, and birth weight significantly affected emergence latency and bite force. Grip strength was not directly affected by early life traits, but bite performance and exploration behavior were impacted by birth weight. This study shows how early life parameters impact personality and performance.

The MAOA promoter polymorphism, disruptive behavior disorders, and early onset substance use disorder: gene-environment interaction.

PubMed

Vanyukov, Michael M; Maher, Brion S; Devlin, Bernie; Kirillova, Galina P; Kirisci, Levent; Yu, Ling-Mei; Ferrell, Robert E

2007-12-01

Conduct, oppositional defiant, and attention deficit hyperactivity disorders, reflecting early antisociality and behavior dysregulation, are predictive of substance use disorders. Liabilities to these disorders share genetic and environmental variance. Parenting characteristics have been shown to influence development of antisociality, moderated by variation at the MAOA gene, which has also been associated with the risk for substance use disorders. To extend these findings, we tested the relationships between the MAOA promoter polymorphism (variable number tandem repeat), indices of child's perception of paternal and maternal parenting, and disruptive behavior disorders and substance use disorders. A sample of 148 European-American males was assessed prospectively at ages from 10-12 to 18-19 years and genotyped for the monoamine oxidase A variable number tandem repeat. The Diagnostic and statistical manual of mental disorder-III-R diagnoses were obtained using standard methodology. Parenting was assessed using a scale summarizing the child's evaluation of the parenting style (parent's behavior toward him, parental emotional distance and involvement). Correlation, logistic regression, and Cox proportional hazard regression analysis was used to determine the relationships between the variables. The strength of association between parenting index and conduct and attention deficit hyperactivity disorders depended on the MAOA genotype. Unlike earlier findings, the parenting-risk relationships were observed in the 'high-' rather than 'low-activity' genotypes. The strength and direction of relationships depended on the parental sex. The MAOA polymorphism's association with the risk for substance use disorders was detected when parenting was controlled for. The results are consistent with the contribution of the MAOA gene, parenting style and their interactions to variation in the risk for early onset behavior disorders and liability to substance use disorders.

Developing a Multi-Dimensional Early Elementary Mathematics Screener and Diagnostic Tool: The Primary Mathematics Assessment.

PubMed

Brendefur, Jonathan L; Johnson, Evelyn S; Thiede, Keith W; Strother, Sam; Severson, Herb H

2018-01-01

There is a critical need to identify primary level students experiencing difficulties in mathematics to provide immediate and targeted instruction that remediates their deficits. However, most early math screening instruments focus only on the concept of number, resulting in inadequate and incomplete information for teachers to design intervention efforts. We propose a mathematics assessment that screens and provides diagnostic information in six domains that are important to building a strong foundation in mathematics. This article describes the conceptual framework and psychometric qualities of a web-based assessment tool, the Primary Math Assessment (PMA). The PMA includes a screener to identify students at risk for poor math outcomes and a diagnostic tool to provide a more in-depth profile of children's specific strengths and weaknesses in mathematics. The PMA allows teachers and school personnel to make better instructional decisions by providing more targeted analyses.

The Significance of Attachment Security for Children’s Social Competence with Peers: A Meta-Analytic Study

PubMed Central

Groh, Ashley M.; Fearon, R. Pasco; Bakermans-Kranenburg, Marian J.; van IJzendoorn, Marinus H.; Steele, Ryan D.; Roisman, Glenn I.

2014-01-01

This meta-analytic review examines the association between attachment during the early life course and social competence with peers during childhood, and compares the strength of this association with those for externalizing and internalizing symptomatology. Based on eighty independent samples (N = 4,441), the association between security and peer competence was significant (d = 0.39, CI 0.32; 0.47) and not moderated by the age at which peer competence was assessed. Avoidance (d = 0.17, CI 0.05; 0.30), resistance (d = 0.29, CI 0.09; 0.48), and disorganization (d = 0.25, CI 0.10; 0.40) were significantly associated with lower peer competence. Attachment security was significantly more strongly associated with peer competence than internalizing (but not externalizing) symptomatology. Discussion focuses on the significance of early attachment for the development of peer competence versus externalizing and internalizing psychopathology. PMID:24547936

Study on the hydration and microstructure of Portland cement containing diethanol-isopropanolamine

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

Ma, Suhua, E-mail: yc982@163.com; Li, Weifeng; Zhang, Shenbiao

2015-01-15

Diethanol-isopropanolamine (DEIPA) is a tertiary alkanolamine used in the formulation of cement grinding-aid additives and concrete early-strength agents. In this research, isothermal calorimetry was used to study the hydration kinetics of Portland cement with DEIPA. A combination of X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC)–thermogravimetric (TG) analysis and micro-Raman spectroscopy was used to investigate the phase development in the process of hydration. Mercury intrusion porosimetry was used to study the pore size distribution and porosity. The results indicate that DEIPA promotes the formation of ettringite (AFt) and enhances the second hydration rate of the aluminatemore » and ferrite phases, the transformation of AFt into monosulfoaluminate (AFm) and the formation of microcrystalline portlandite (CH) at early stages. At later stages, DEIPA accelerates the hydration of alite and reduces the pore size and porosity.« less

Strengths-Based Nursing: A Process for Implementing a Philosophy Into Practice.

PubMed

Gottlieb, Laurie N; Gottlieb, Bruce

2017-08-01

Strengths-Based Nursing (SBN) is both a philosophy and value-driven approach that can guide clinicians, educators, manager/leaders, and researchers. SBN is rooted in principles of person/family centered care, empowerment, relational care, and innate health and healing. SBN is family nursing yet not all family nursing models are strengths-based. The challenge is how to translate a philosophy to change practice. In this article, we describe a process of implementation that has organically evolved of a multi-layered and multi-pronged approach that involves patients and families, clinicians, educators, leaders, managers, and researchers as well as key stakeholders including union leaders, opinion leaders, and policy makers from both nursing and other disciplines. There are two phases to the implementation process, namely, Phase 1: pre-commitment/pre-adoption and Phase 2: adoption. Each phase consists of distinct steps with accompanying strategies. These phases occur both sequentially and concurrently. Facilitating factors that enable the implementation process include values which align, readiness to accept SBN, curiosity-courage-commitment on the part of early adopters, a critical mass of early adopters, and making SBN approach both relevant and context specific.

[Role of physical activity in the prevention of osteoporosis].

PubMed

Siegrist, Monika

2008-07-01

In recent years, osteoporosis has become a leading cause of morbidity and mortality in elderly women. Research has demonstrated that the prevention of osteoporosis and osteoporosis-related fractures may best be achieved by initiating sound health behaviors early in life and continuing them throughout life. Evidence suggests that osteoporosis is easier to prevent than to treat. In fact, healthy early life practices, including the adequate consumption of most nutrients, calcium in particular, and regular physical activity, contribute to greater bone mineral mass and optimal peak bone mass. Bone is living tissue that responds to exercise by becoming stronger. Two types of exercises are important for building and maintaining bone mass and density: Weight-bearing exercises, in which bones and muscles work against gravity and resistance training that use muscular strength to improve muscle mass and strengthen bone. Exercise can also improve gait, balance, coordination, proprioception, reaction time, and muscle strength, even in very old and frail elderly people. Overall, the evidence strongly suggests that regular physical activity, especially started in childhood and adolescence, is a cheap and safe way of both improving bone strength and reducing the risk to fall.

Study on strength estimation of soil cement used in the embedded pile method by electrical resistivity measurement

NASA Astrophysics Data System (ADS)

Mochida, Y.; Sakurai, Y.; Indra, H.; Karimi, A. L.

2017-11-01

Problems caused by poor quality control and quality assurance of the pre-boring embedded pile construction, such as on domestic apartment house is still occurring nowadays. An adequate consideration for invisible risks inside or below the ground is important in pile foundation construction therefore the demand for advanced and reliable quality assurance is increase in the future. In this research, to understand the quality of the construction at early stage, the compressive strength of cement-soil mixture of pile construction after 28 days is estimated using electrical resistivity value of the mixture. More accurate measurement for electrical resistivity value is conducted by inserting the electrodes without using potassium chloride solution as a catalyst. The result showed that there is a certain tendency in the electric resistivity value at the early age regarding to the type of soil (sand, clay) mixed in. The most accurate estimation was achieved from the electric resistivity value at the first day and several days onwards, and from the compressive strength after 3 days.

Composite Stress Rupture: A New Reliability Model Based on Strength Decay

NASA Technical Reports Server (NTRS)

Reeder, James R.

2012-01-01

A model is proposed to estimate reliability for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures. This new reliability model is generated by assuming a strength degradation (or decay) over time. The model suggests that most of the strength decay occurs late in life. The strength decay model will be shown to predict a response similar to that predicted by a traditional reliability model for stress rupture based on tests at a single stress level. In addition, the model predicts that even though there is strength decay due to proof loading, a significant overall increase in reliability is gained by eliminating any weak vessels, which would fail early. The model predicts that there should be significant periods of safe life following proof loading, because time is required for the strength to decay from the proof stress level to the subsequent loading level. Suggestions for testing the strength decay reliability model have been made. If the strength decay reliability model predictions are shown through testing to be accurate, COPVs may be designed to carry a higher level of stress than is currently allowed, which will enable the production of lighter structures

Early warnings: health care preparedness.

PubMed

Rebmann, Terri

2005-11-01

As nurses, we represent the backbone of the health care system. It is essential that we have a core understanding of infectious disease emergencies and begin to use the strengths that characterize nursing. These strengths include the ability to evaluate situations and use evidence on which to base our actions. Early identification of an infectious disease emergency is one example of using nursing skills to strengthen emergency preparedness. During an infectious disease emergency, nurses certainly will bear the burden of patient management. Because of this, the need for infectious disease emergency preparedness has become a national priority and a moral imperative for all nurses. One topic necessary for ED and OH nurses' preparedness has been discussed in this article, but nurses must take the initiative to learn more about disaster preparedness and incorporate these skills into everyday practice.

Bringing Researchers and Community Developers Together to Revitalize a Public Housing Project and Improve Health

PubMed Central

LeWinn, Kaja Z.; Hutson, Malo A.; Dare, Ramie; Falk, Janet

2014-01-01

Billions of dollars are invested annually to improve low-income neighborhoods, the health impacts of which are rarely studied prospectively. University of California researchers and Mercy Housing/The Related Companies formed a “Learning Community” with the dual goals of examining the health impacts of a large-scale San Francisco redevelopment project and informing the development team of best public health practices. Early experiences highlight challenges and opportunities, including differences in stakeholders, incentives, and funding, the strengths of local partnerships, and fresh insights from new analytic tools and perspectives. Research suggests interventions that ameliorate upstream causes of poor health would save health care dollars, but policy makers must incentivize collaboration in order to spread a Learning Community model. PMID:22068398

Pharmacogenomics in Asia: a systematic review on current trends and novel discoveries.

PubMed

Ang, Hazel Xiaohui; Chan, Sze Ling; Sani, Levana L; Quah, Clarissa Bernice; Brunham, Liam R; Tan, Boon Ooi Patrick; Winther, Michael D

2017-06-01

While early pharmacogenomic studies have primarily been carried out in Western populations, there has been a notable increase in the number of Asian studies over the past decade. We systematically reviewed all pharmacogenomic studies conducted in Asia published before 2016 to highlight trends and identify research gaps in Asia. We observed that pharmacogenomic research in Asia was dominated by larger developed countries, notably Japan and Korea, and mainly driven by local researchers. Studies were focused on drugs acting on the CNS, chemotherapeutics and anticoagulants. Significantly, several novel pharmacogenomic associations have emerged from Asian studies. These developments are highly encouraging for the strength of regional scientific and clinical community and propound the importance of discovery studies in different populations.

Advanced Structural Optimization Under Consideration of Cost Tracking

NASA Astrophysics Data System (ADS)

Zell, D.; Link, T.; Bickelmaier, S.; Albinger, J.; Weikert, S.; Cremaschi, F.; Wiegand, A.

2014-06-01

In order to improve the design process of launcher configurations in the early development phase, the software Multidisciplinary Optimization (MDO) was developed. The tool combines different efficient software tools such as Optimal Design Investigations (ODIN) for structural optimizations, Aerospace Trajectory Optimization Software (ASTOS) for trajectory and vehicle design optimization for a defined payload and mission.The present paper focuses to the integration and validation of ODIN. ODIN enables the user to optimize typical axis-symmetric structures by means of sizing the stiffening designs concerning strength and stability while minimizing the structural mass. In addition a fully automatic finite element model (FEM) generator module creates ready-to-run FEM models of a complete stage or launcher assembly.Cost tracking respectively future improvements concerning cost optimization are indicated.

Gut microbiota-bone axis.

PubMed

Villa, Christopher R; Ward, Wendy E; Comelli, Elena M

2017-05-24

The gut microbiota (GM) is an important regulator of body homeostasis, including intestinal and extra-intestinal effects. This review focuses on the GM-bone axis, which we define as the effect of the gut-associated microbial community or the molecules they synthesize, on bone health. While research in this field is limited, findings from preclinical studies support that gut microbes positively impact bone mineral density and strength parameters. Moreover, administration of beneficial bacteria (probiotics) in preclinical models has demonstrated higher bone mineralization and greater bone strength. The preferential bacterial genus that has shown these beneficial effects in bone is Lactobacillus and thus lactobacilli are among the best candidates for future clinical intervention trials. However, their effectiveness is dependent on stage of development, as early life constitutes an important time for impacting bone health, perhaps via modulation of the GM. In addition, sex-specific difference also impacts the efficacy of the probiotics. Although auspicious, many questions regarding the GM-bone axis require consideration of potential mechanisms; sex-specific efficacy; effective dose of probiotics; and timing and duration of treatment.

Ceramics for engines

NASA Technical Reports Server (NTRS)

Kiser, James D.; Levine, Stanley R.; Dicarlo, James A.

1987-01-01

Structural ceramics were under nearly continuous development for various heat engine applications since the early 1970s. These efforts were sustained by the properties that ceramics offer in the areas of high-temperature strength, environmental resistance, and low density and the large benefits in system efficiency and performance that can result. The promise of ceramics was not realized because their brittle nature results in high sensitivity to microscopic flaws and catastrophic fracture behavior. This translated into low reliability for ceramic components and thus limited their application in engines. For structural ceramics to successfully make inroads into the terrestrial heat engine market requires further advances in low cost, net shape fabrication of high reliability components, and improvements in properties such as toughness, and strength. These advances will lead to very limited use of ceramics in noncritical applications in aerospace engines. For critical aerospace applications, an additional requirement is that the components display markedly improved toughness and noncatastrophic or graceful fracture. Thus the major emphasis is on fiber-reinforced ceramics.

[Prevalence of emotional and behavioral symptomatology in Spanish adolescents].

PubMed

Ortuño-Sierra, Javier; Fonseca-Pedrero, Eduardo; Paíno, Mercedes; Aritio-Solana, Rebeca

2014-01-01

The main purpose of this study was to examine the prevalence of symptoms of an emotional and behavioral nature, as well as prosocial type capabilities, measured using the Strengths and Difficulties Questionnaire, in non-clinical adolescents. The final sample was composed of a total of 508 students, 208 male (40.9%). The age of participants ranged from 11 to 18 years (M=13.91 years; SD=1.71). The results show that a significant number of adolescents self-reported emotional and behavioral problems. The mean scores of the Strengths and Difficulties Questionnaire subscales varied according the gender and age of the adolescents. In the present study, the prevalence of psychological difficulties among adolescents was similar to that reported in other national and international studies. In view of these results, there is a need to develop programs for the early detection of these types of problems in schools in children and adolescents ages. Copyright © 2013 SEP y SEPB. Published by Elsevier España. All rights reserved.

Nano-modification to improve the ductility of cementitious composites

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

Yeşilmen, Seda; Al-Najjar, Yazin; Balav, Mohammad Hatam

2015-10-15

Effect of nano-sized mineral additions on ductility of engineered cementitious composites (ECC) containing high volumes of fly ash was investigated at different hydration degrees. Various properties of ECC mixtures with different mineral additions were compared in terms of microstructural properties of matrix, fiber-matrix interface, and fiber surface to assess improvements in ductility. Microstructural characterization was made by measuring pore size distributions through mercury intrusion porosimetry (MIP). Hydration characteristics were assessed using thermogravimetric analysis/differential thermal analysis (TGA/DTA), and fiber-matrix interface and fiber surface characteristics were assessed using scanning electron microscopy (SEM) through a period of 90 days. Moreover, compressive and flexuralmore » strength developments were monitored for the same period. Test results confirmed that mineral additions could significantly improve both flexural strength and ductility of ECC, especially at early ages. Cheaper Nano-CaCO{sub 3} was more effective compared to nano-silica. However, the crystal structure of CaCO{sub 3} played a very important role in the range of expected improvements.« less

Recovery of white sturgeon populations through natural production: Understanding the influence of abiotic and biotic factors on spawning and subsequent recruitment

USGS Publications Warehouse

Parsley, M.J.; Anders, P.J.; Miller, Allen I.; Beckman, L.G.; McCabe, G.T.

2002-01-01

Recovery or maintenance of sturgeon populations through natural production in perturbed rivers requires adequate knowledge of the abiotic and biotic factors that influence spawning and cause mortality of embryonic, larval, and juvenile life stages. Although it is known that year-class strength of white sturgeon Acipenser transmontanus is determined within 2-3 months after spawning, little is known about specific causes of mortality to early life stages during this period. Initial spawning success is critical in the development of a strong year-class, and maximized recruitment may be dependent upon water temperature and the availability of optimal in-river habitat. Analyses have shown that increased river discharge combined with suitable water temperatures during spawning, egg incubation, yolk sac larvae dispersal, and first exogenous feeding result in greater recruitment. However, little is known about the importance of other variables, such as food availability or losses due to predation that influence year-class strength. ?? 2002 by the American Fisheries Society.

Determination of Temperature- Dependent Mechanical Properties of Carbon Composites Under Tensile and Flexural Loading

NASA Astrophysics Data System (ADS)

Chripunow, Andre; Kubisch, Aline; Ruder, Matthias; Forster, Andreas; Korber, Hannes

2014-06-01

The presented test setup utilises a custom-built furnace realising test temperatures of up to 500°C. In order to ensure always optimal test conditions the temperature cell can be exchanged depending on the mechanical tests and specimen sizes. Cells for tensile and flexural loadings had been developed. With the latter one it is possible to perform three-point-bending tests, interlaminar-shear-strength tests as well as tests to determine the interlaminar fracture toughness. In this work the effect of fibre orientation on the mechanical properties of CFRP prepreg material under tensile and flexural loads at elevated temperatures was studied. Especially the matrix dominated layups showed a rather early decay of the mechanical properties even at temperatures quite lower than Tg. An analytical model has been used to describe the temperature-dependent properties. The model shows good agreement concerning the strength whereas the proper prediction of the moduli was only possible for the matrix dominated layups.

Behavioural medicine and gastrointestinal disorders: the promise of positive psychology.

PubMed

Keefer, Laurie

2018-04-12

Psychosocial risk factors linked to brain-gut dysregulation are prevalent across the spectrum of gastrointestinal disorders and are associated with poor patient outcomes. Robust and reproducible data in the areas of behavioural intervention science and the brain-gut axis have led to major advances in patient care, including the routine use of brain-gut psychotherapies to manage digestive symptoms and optimize coping. The logical next step for the emerging field of psychogastroenterology is to develop a scientific framework that enables the identification of those individual characteristics and coping styles that buffer patients against the negative psychological effects of chronic gastrointestinal disorders. A shift towards a strength-based, positive psychological science of gastrointestinal disorders could facilitate the integration of early, effective psychological care into gastroenterology practice. In this Perspective, I discuss the potential role of three human strengths with relevance to gastrointestinal health - resilience, optimism and self-regulation - and how these three constructs can be cultivated through existing or emerging brain-gut psychotherapies.

Superstrong Adjustable Permanent Magnet for a Linear Collider Final Focus

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

Mihara, T.

A superstrong permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens for the linear collider because of its compactness and low power consumption. The first fabricated prototype of our PMQ achieved a 300T/m superstrong field gradient with a 100mm overall magnet radius and a 7mm bore radius, but a drawback is its fixed strength. Therefore, a second prototype of PMQ, whose strength is adjustable, was fabricated. Its strength adjustability is based on the ''double ring structure'', rotating subdivided magnet slices separately. This second prototype is being tested. Some of the early results are presented.

Maturational differences in physical self- perceptions and the relationship with physical activity in early adolescent girls.

PubMed

Niven, Alisa G; Fawkner, Samantha G; Knowles, Anne-Marie; Stephenson, Claire

2007-11-01

This cross-sectional study examined the relationship between physical self-perceptions (PSPs), maturation, and physical activity and compared the strength of the relationships of biological and chronological age with PSPs in early adolescent girls (N = 208; mean age = 11.83 +/- 0.39 years). Participants completed the Physical Activity Questionnaire for Older Children, the Children's Physical Self-Perception Profile, and the Pubertal Development Scale. Results indicated that PSPs were significantly and moderately correlated with physical activity. There were no differences in physical activity between maturation stages. Girls who were in the early stages of maturation had significantly more positive perceptions of body attractiveness and physical self-worth than girls in the mid stages of maturation. There was no evidence of a relationship between PSPs and chronological age. This study provided further support for the relationship between PSPs and physical activity and the relationship between maturation and aspects of PSPs. In this age group, maturation does not appear to be related to physical activity or the PSPs most strongly influential on physical activity behavior.

Closed-Loop Neuromodulation Systems: Next-Generation Treatments for Psychiatric Illness

PubMed Central

Lo, Meng-Chen; Widge, Alik S.

2017-01-01

Despite deep brain stimulation’s positive early results in psychiatric disorders, well-designed clinical trials have yielded inconsistent clinical outcomes. One path to more reliable benefit is closed-loop therapy: stimulation that is automatically adjusted by a device or algorithm in response to changes in the patient’s electrical brain activity. These interventions may provide more precise and patient-specific treatments. In this article, we first introduce the available closed-loop neuromodulation platforms, which have shown clinical efficacy in epilepsy and strong early results in movement disorders. We discuss the strengths and limitations of these devices in the context of psychiatric illness. We then describe emerging technologies to address these limitations, including pre-clinical developments such as wireless deep neurostimulation and genetically targeted neuromodulation. Finally, we discuss ongoing challenges and limitations for closed-loop psychiatric brain stimulation development, most notably the difficulty of identifying meaningful biomarkers for titration. We consider this in the recently-released Research Domain Criteria (RDoC) framework and describe how neuromodulation and RDoC are jointly very well suited to address the problem of treatment-resistant illness. PMID:28523978

Effects of fine sediment, hyporheic flow, and spawning site characteristics on survival and development of bull trout embryos

USGS Publications Warehouse

Bowerman, Tracy; Neilson, Bethany; Budy, Phaedra

2014-01-01

Successful spawning is imperative for the persistence of salmonid populations, but relatively little research has been conducted to evaluate factors affecting early life-stage survival for bull trout (Salvelinus confluentus), a threatened char. We conducted a field experiment to assess the relationship between site-specific environmental factors and bull trout embryo survival and fry emergence timing. Survival from egg to hatch was negatively related to percent fine sediment (<1 mm) in the redd and positively related to the strength of downwelling at spawning sites. Survival of eggs to fry emergence was also negatively related to fine sediment, and the best statistical models included additional variables that described the rate of downwelling and intragravel flow within the incubation environment. Fry emerged at an earlier stage in development from redds with high percentages of fine sediment. Increased hydraulic conductivity via redd construction and selection of spawning sites with strong downwelling appear to enhance hyporheic flow rates and bull trout egg survival, but early life-stage success may ultimately be limited by intrusion of fine sediment into the incubation environment.

Magnetic susceptibility and magnetic resonance measurements of the moisture content and hydration condition of a magnetic mixture material

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

Tsukada, K., E-mail: tsukada@cc.okayama-u.ac.jp; Kusaka, T.; Saari, M. M.

2014-05-07

We developed a magnetic measurement method to measure the moisture content and hydration condition of mortar as a magnetic mixture material. Mortar is a mixture of Portland cement, sand, and water, and these materials exhibit different magnetic properties. The magnetization–magnetic field curves of these components and of mortars with different moisture contents were measured, using a specially developed high-temperature-superconductor superconducting quantum interference device. Using the differences in magnetic characteristics, the moisture content of mortar was measured at the ferromagnetic saturation region over 250 mT. A correlation between magnetic susceptibility and moisture content was successfully established. After Portland cement and water aremore » mixed, hydration begins. At the early stage of the hydration/gel, magnetization strength increased over time. To investigate the magnetization change, we measured the distribution between bound and free water in the mortar in the early stage by magnetic resonance imaging (MRI). The MRI results suggest that the amount of free water in mortar correlates with the change in magnetic susceptibility.« less

Early postoperative repair status after rotator cuff repair cannot be accurately classified using questionnaires of patient function and isokinetic strength evaluation.

PubMed

Colliver, Jessica; Wang, Allan; Joss, Brendan; Ebert, Jay; Koh, Eamon; Breidahl, William; Ackland, Timothy

2016-04-01

This study investigated if patients with an intact tendon repair or partial-thickness retear early after rotator cuff repair display differences in clinical evaluations and whether early tendon healing can be predicted using these assessments. We prospectively evaluated 60 patients at 16 weeks after arthroscopic supraspinatus repair. Evaluation included the Oxford Shoulder Score, 11-item version of the Disabilities of the Arm, Shoulder and Hand, visual analog scale for pain, 12-item Short Form Health Survey, isokinetic strength, and magnetic resonance imaging (MRI). Independent t tests investigated clinical differences in patients based on the Sugaya MRI rotator cuff classification system (grades 1, 2, or 3). Discriminant analysis determined whether intact repairs (Sugaya grade 1) and partial-thickness retears (Sugaya grades 2 and 3) could be predicted. No differences (P < .05) existed in the clinical or strength measures. Although discriminant analysis revealed the 11-item version of the Disabilities of the Arm, Shoulder and Hand produced a 97% true-positive rate for predicting partial thickness retears, it also produced a 90% false-positive rate whereby it incorrectly predicted a retear in 90% of patients whose repair was intact. The ability to discriminate between groups was enhanced with up to 5 variables entered; however, only 87% of the partial-retear group and 36% of the intact-repair group were correctly classified. No differences in clinical scores existed between patients stratified by the Sugaya MRI classification system at 16 weeks. An intact repair or partial-thickness retear could not be accurately predicted. Our results suggest that correct classification of healing in the early postoperative stages should involve imaging. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The fabrication and characterization of a multi-laminate, angle-ply collagen patch for annulus fibrosus repair.

PubMed

McGuire, Rachel; Borem, Ryan; Mercuri, Jeremy

2017-12-01

One major limitation of intervertebral disc (IVD) repair is that no ideal biomaterial has been developed that effectively mimics the angle-ply collagen architecture and mechanical properties of the native annulus fibrosus (AF). Furthermore, it would be beneficial to devise a simple, scalable process by which to manufacture a biomimetic biomaterial that could function as a mechanical repair patch to be secured over a large defect in the outer AF that will support AF tissue regeneration. Such a biomaterial would: (1) enable the employment of early-stage interventional strategies to treat IVD degeneration (i.e. nucleus pulposus arthroplasty); (2) prevent IVD re-herniation in patients with large AF defects; and (3) serve as a platform to develop full-thickness AF and whole IVD tissue engineering strategies. Due to the innate collagen fibre alignment and mechanical strength of pericardium, a procedure was developed to assemble multi-laminate angle-ply AF patches derived from decellularized pericardial tissue. Patches were subsequently assessed histologically to confirm angle-ply microarchitecture, and mechanically assessed for biaxial burst strength and tensile properties. Additionally, patch cytocompatibility was evaluated following seeding with bovine AF cells. This study demonstrated the effective removal of porcine cell remnants from the pericardium, and the ability to reliably produce multi-laminate patches with angle-ply architecture using a simple assembly technique. Resultant patches demonstrated their inherent ability to resist biaxial burst pressures reminiscent of intradiscal pressures commonly borne by the AF, and exhibited tensile strength and modulus values reported for native human AF. Furthermore, the biomaterial supported AF cell viability, infiltration and proliferation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Comparison of two different rehabilitation programmes for thrust plate prosthesis: a randomized controlled study.

PubMed

Unver, Bayram; Karatosun, Vasfi; Gunal, Izge; Angin, Salih

2004-02-01

Weight bearing after total hip arthroplasty is postponed in order to prevent early loosening, but this negatively affects the rehabilitation programme. For the force transfer characteristics of thrust plate prosthesis (TPP), a new type of hip prosthesis used without cement is similar to the normal hip. We evaluated the possibilities of early weight bearing after TPP by comparing early partial with early full weight bearing. Randomized controlled study. Department of orthopaedics and traumatology in a university hospital. Sixty hips of 51 patients who underwent total hip arthroplasty with TPP were randomly assigned into two groups. Both groups received accelerated rehabilitation programmes: group 1 with early partial weight bearing and group 2 with early full weight bearing. Patients were evaluated by a blind observer preoperatively, at three months after surgery by clinical (measurement of range of hip motion (universal goniometry), muscle strength (Manual Muscle Test), functional test (6-minute walk test), hip function (Harris Hip Scoring System)) and radiographical parameters and one year after surgery by clinical (Harris Hip Scoring System) and radiographical parameters. Group 2 performed transfer activities earlier, had more walking distance at the time of discharge and shorter hospital stay than group 1. At three months, Harris Hip Score, muscle strength, 6-minute walk test, and duration of crutch use were significantly (p < 0.05) in favour of group 2. None of the patients in either group showed signs of loosening one year after the operation. These results suggest that patients with TPP can tolerate an accelerated rehabilitation programme with early weight bearing and will gain the goals of rehabilitation earlier.

Rapid weight gain after birth predicts life history and reproductive strategy in Filipino males

PubMed Central

Kuzawa, Christopher W.; McDade, Thomas W.; Adair, Linda S.; Lee, Nanette

2010-01-01

Ecological cues during prenatal and postnatal development may allow organisms to adjust reproductive strategy. The hypothalamic-pituitary-gonadal (HPG) axis is a prime candidate for adaptive plasticity as a result of its critical period of birth to 6 mo (B6M) in humans and the role of testosterone in the development and maintenance of costly sexually dimorphic somatic and behavioral traits. We hypothesized that weight velocity specific to B6M would predict male life history characteristics, including maturational timing, reproductive hormones, adult size, strength, and sexual activity. Data come from 770 Filipino men (age 20.5–22.5 y) followed since birth, with predictor variables including birth weight and weight velocities calculated at 6-mo intervals during the first 2 y of life. As expected, infants who were breastfed experienced less diarrhea, lived in wealthier households with better hygiene, and grew faster from B6M. Males with rapid B6M growth reached puberty earlier and, as young adults, had higher testosterone levels, were taller, more muscular, and had higher grip strength. They also had sex earlier and were more likely to report having had sex in the past month, resulting in more lifetime sex partners. Relationships between B6M weight gain and physical outcomes were generally not present or weaker in female subjects. We conclude that rapid weight gain specific to the brief postnatal hypothalamic-pituitary-gonadal critical period predicts early maturation and sexual activity, elevated hormone production, and more costly adult somatic characteristics among the male subjects in this sample. These findings provide evidence for early life developmental plasticity in male life history and reproductive strategy in humans. PMID:20837542

Sports Specialization, Part II: Alternative Solutions to Early Sport Specialization in Youth Athletes.

PubMed

Myer, Gregory D; Jayanthi, Neeru; DiFiori, John P; Faigenbaum, Avery D; Kiefer, Adam W; Logerstedt, David; Micheli, Lyle J

2016-01-01

Many coaches, parents, and children believe that the best way to develop elite athletes is for them to participate in only 1 sport from an early age and to play it year-round. However, emerging evidence to the contrary indicates that efforts to specialize in 1 sport may reduce opportunities for all children to participate in a diverse year-round sports season and can lead to lost development of lifetime sports skills. Early sports specialization may also reduce motor skill development and ongoing participation in games and sports as a lifestyle choice. The purpose of this review is to employ the current literature to provide evidence-based alternative strategies that may help to optimize opportunities for all aspiring young athletes to maximize their health, fitness, and sports performance. Nonsystematic review with critical appraisal of existing literature. Clinical review. Level 4. Based on the current evidence, parents and educators should help provide opportunities for free unstructured play to improve motor skill development and youth should be encouraged to participate in a variety of sports during their growing years to influence the development of diverse motor skills. For those children who do choose to specialize in a single sport, periods of intense training and specialized sport activities should be closely monitored for indicators of burnout, overuse injury, or potential decrements in performance due to overtraining. Last, the evidence indicates that all youth should be involved in periodized strength and conditioning (eg, integrative neuromuscular training) to help them prepare for the demands of competitive sport participation, and youth who specialize in a single sport should plan periods of isolated and focused integrative neuromuscular training to enhance diverse motor skill development and reduce injury risk factors. B. © 2015 The Author(s).

Strength and balance training for adults with peripheral neuropathy and high risk of fall: current evidence and implications for future research.

PubMed

Tofthagen, Cindy; Visovsky, Constance; Berry, Donna L

2012-09-01

To evaluate the evidence for strength- and balance-training programs in patients at high risk for falls, discuss how results of existing studies might guide clinical practice, and discuss directions for additional research. A search of PubMed and CINAHL® databases was conducted in June 2011 using the terms strength, balance training, falls, elderly, and neuropathy. Only clinical trials conducted using specific strength- or balance-training exercises that included community-dwelling adults and examined falls, fall risk, balance, and/or strength as outcome measures were included in this review. One matched case-control study and two randomized, controlled studies evaluating strength and balance training in patients with diabetes-related peripheral neuropathy were identified. Eleven studies evaluating strength and balance programs in community-dwelling adults at high risk for falls were identified. The findings from the reviewed studies provide substantial evidence to support the use of strength and balance training for older adults at risk for falls, and detail early evidence to support strength and balance training for individuals with peripheral neuropathy. The evidence demonstrates that strength and balance training is safe and effective at reducing falls and improving lower extremity strength and balance in adults aged 50 years and older at high risk for falls, including patients with diabetic peripheral neuropathy. Future studies should evaluate the effects of strength and balance training in patients with cancer, particularly individuals with chemotherapy-induced peripheral neuropathy.

No association between rate of torque development and onset of muscle activity with increased risk of hamstring injury in elite football.

PubMed

van Dyk, Nicol; Bahr, Roald; Burnett, Angus F; Verhagen, Evert; von Tiggelen, Damien; Witvrouw, Erik

2018-05-23

Hamstring injuries remain a significant burden in sports that involve high speed running. In elite male football, hamstring injury has repeatedly been identified as the most common noncontact injury, representing 12% of all injuries. As the incidence remains high, investigations are aimed at better understanding how to improve prevention efforts. Intrinsic risk factors such as strength have been investigated extensively in a cohort of professional football players; however, other intrinsic measures of neuromuscular function have not been studied in this cohort. This study aims to investigate the association between timing of hamstring muscle activity onset and the rate of torque development during the early phase of isokinetic strength testing with risk of hamstring injury in professional football players in a prospective cohort study. All teams (n=18) eligible to compete in the premier football league in Qatar underwent a comprehensive strength assessment during their annual periodic health evaluation at Aspetar Orthopaedic and Sports Medicine Hospital in Doha, Qatar. Variables included rate of torque development and timing of muscle activity onset. A total of 367 unique players (60.6% of all QSL players) competed for 514 player seasons (103 players competed both seasons) and sustained 65 hamstring injuries. There was no difference in the onset of muscle activity between the biceps femoris and medial hamstrings comparing the injured to uninjured players. For both onset of muscle activity and rate of torque development, there were no significant differences between any of the variables (p>0.05), with small effect sizes detected across all the different variables (d<0.3). Rate of torque development and onset of muscle activity were not associated with a risk of future hamstring injury. The use of these measures as part of a periodic health evaluation to identify risk of hamstring injury is unsupported. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Possibilities for specific utilization of material properties for an optimal part design

NASA Astrophysics Data System (ADS)

Beier, T.; Gerlach, J.; Roettger, R.; Kuhn, P.

2017-09-01

High-strength, cold-formable steels offer great potential for meeting cost and safety requirements in the automotive industry. In view of strengths of up to 1200 MPa now attainable, certain aspects need to be analysed and evaluated in advance in the development process using these materials. In addition to early assessment of crash properties, it is also highly important to adapt the forming process to match the material potential. The steel making companies have widened their portfolios of cold-rolled dual-phase steels well beyond the conventional high-strength steels. There are added new grades which offer a customized selection of high energy absorption, deformation resistance or enhanced cold-forming properties. In this article the necessary components for material modelling for finite element simulation are discussed. Additionally the required tests for material model calibration are presented and the potentials of the thyssenkrupp Steel material data base are introduced. Besides classical tensile tests at different angles to rolling direction and the forming limit curve, the hydraulic bulge test is now available for a wide range of modern steel grades. Using the conventional DP-K®60/98 and the DP-K®700Y980T with higher yield strength the method for calibrating yield locus, hardening and formability is given. With reference to the examples of an A-pillar reinforcement and different crash tests the procedure is shown how the customer can evaluate an optimal steel grade for specific requirements. Although the investigated materials have different yield strengths, no large differences in the forming process between the two steel grades can be found. However some advantages of the high-yield grade can be detected in crash performance depending on the specific boundary and loading conditions.

Effects of asymptomatic rotator cuff pathology on in vivo shoulder motion and clinical outcomes.

PubMed

Baumer, Timothy G; Dischler, Jack; Mende, Veronica; Zauel, Roger; van Holsbeeck, Marnix; Siegal, Daniel S; Divine, George; Moutzouros, Vasilios; Bey, Michael J

2017-06-01

The incidence of asymptomatic rotator cuff tears has been reported to range from 15% to 39%, but the influence of asymptomatic rotator cuff pathology on shoulder function is not well understood. This study assessed the effects of asymptomatic rotator cuff pathology on shoulder kinematics, strength, and patient-reported outcomes. A clinical ultrasound examination was performed in 46 asymptomatic volunteers (age: 60.3 ± 7.5 years) with normal shoulder function to document the condition of their rotator cuff. The ultrasound imaging identified the participants as healthy (n = 14) or pathologic (n = 32). Shoulder motion was measured with a biplane x-ray imaging system, strength was assessed with a Biodex (Biodex Medical Systems, Inc., Shirley, NY, USA), and patient-reported outcomes were assessed using the Western Ontario Rotator Cuff Index and visual analog scale pain scores. Compared with healthy volunteers, those with rotator cuff pathology had significantly less abduction (P = .050) and elevation (P = .041) strength, their humerus was positioned more inferiorly on the glenoid (P = .018), and the glenohumeral contact path length was longer (P = .007). No significant differences were detected in the Western Ontario Rotator Cuff Index, visual analog scale, range of motion, or acromiohumeral distance. The differences observed between the healthy volunteers and those with asymptomatic rotator cuff pathology lend insight into the changes in joint mechanics, shoulder strength, and conventional clinical outcomes associated with the early stages of rotator cuff pathology. Furthermore, these findings suggest a plausible mechanical progression of kinematic and strength changes associated with the development of rotator cuff pathology. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Is back pain during childhood or adolescence associated with muscle strength, muscle endurance or aerobic capacity: three systematic literature reviews with one meta-analysis.

PubMed

Lardon, Arnaud; Leboeuf-Yde, Charlotte; Le Scanff, Christine

2015-01-01

Back pain is a common condition during childhood and adolescence. The causes of back pain are largely unknown but it seems plausible that some physical factors such as back muscle strength, back muscle endurance and aerobic capacity may play a role in its development, in particular in the early years. The objectives of this review were to investigate in childhood and adolescence 1) if muscular strength in trunk extension is associated with back pain, 2) if muscular endurance in trunk extension is associated with back pain and 3) if aerobic capacity is associated with back pain. Three systematic critical literature reviews with one meta-analysis. Systematic searches were made in June 2014 in PubMed, Embase and SportDiscus including longitudinal, retrospective or cross-sectional studies on back pain for subjects <20 years. Articles were accepted if they were written in French or English. The review process followed the AMSTAR recommendations. The possibility of conducting a meta-analysis was assessed for each research question. Four articles were included for the first objective, four for the second and three for the last. None of the included articles found an association between back muscle strength in extension and back pain. For the second objective, a protective association between back muscle endurance in extension and back pain was found, later confirmed in a meta-analysis (OR = 0.75, 95 % CI 0.58-0.98). The association between aerobic capacity and back pain is not clear. High back muscle endurance in extension appears protective of back pain in youngsters, but the roles of high back muscle strength in extension and aerobic capacity are less clear.

Impaired Aerobic Endurance and Muscular Strength in Substance Use Disorder Patients

PubMed Central

Flemmen, Grete; Wang, Eivind

2015-01-01

Abstract Although substance use disorder (SUD) patients are documented to have an inactive lifestyle, which is associated with cardiovascular disease, other lifestyle-related diseases and premature death, evidence regarding their aerobic endurance and muscular strength is limited. Therefore, the authors aimed to evaluate directly assessed maximal oxygen consumption, walking efficiency, as well as maximal strength in a group of SUD patients. A total of 44 SUD patients in residential treatment, 31 men (31 ± 8 years) and 13 women (34 ± 10 years), were included and completed the physical testing. The patients were compared with an age- and sex-matched reference group. Male and female SUD patients exhibited a maximal oxygen consumption of 44.6 ± 6.2 and 33.8 ± 6.6 mL· min−1 kg−1, respectively. This was significantly lower than the reference group, 15% (P = 0.03) for men and 25% (P = 0.001) for women. In addition, the SUD patients had a 13% significantly reduced walking efficiency (P = 0.02), compared with healthy controls. The impairments in aerobic endurance were accompanied by significant reductions in maximal strength of 30% (P = 0.001) and 33% (P = 0.01) for men and women, respectively. In combination, these results imply that SUD patients have impaired endurance and muscular strength compared with what is typically observed in the population, and consequently suffer a higher risk of developing cardiovascular and other lifestyle-related diseases and early death. Effective physical exercise should be advocated as an essential part of the clinical practice of SUD treatment to improve the patient's health and consequently reduce the costs because of the high use of emergency departments, hospital, and medical care. PMID:26554792

Effectiveness of resistance training on muscle strength and physical function in people with Parkinson's disease: a systematic review and meta-analysis.

PubMed

Chung, Chloe Lau Ha; Thilarajah, Shamala; Tan, Dawn

2016-01-01

To systematically review the evidence investigating the effectiveness of resistance training on strength and physical function in people with Parkinson's disease. Seven electronic databases (COCHRANE, CINAHL, Medline ISI, Psycinfo, Scopus, Web of Science ISI and Embase) were systematically searched for full-text articles published in English between 1946 and November 2014 using relevant search terms. Only randomized controlled trials investigating the effects of resistance training on muscle strength and physical function in people with Parkinson's disease were considered. The PEDro scale was used to assess study quality. Studies with similar outcomes were pooled by calculating standardized mean differences (SMD) using fixed or random effects model, depending on study heterogeneity. Seven studies, comprising of 401 participants with early to advanced disease (Hoehn & Yahr stage 1 to 4), were included. The median quality score was 6/10. The meta-analyses demonstrated significant SMD in favour of resistance training compared to non-resistance training or no intervention controls for muscle strength (0.61; 95% CI, 0.35 to 0.87; P <0.001), balance (0.36; 95% CI, 0.08 to 0.64; P = 0.01) and parkinsonian motor symptoms (0.48; 95% CI, 0.21 to 0.75; P < 0.001) but not for gait, balance confidence and quality of life. This review demonstrates that moderate intensity progressive resistance training, 2-3 times per week over 8-10 weeks can result in significant strength, balance and motor symptoms gains in people with early to moderate Parkinson's disease. © The Author(s) 2015.

Effects of a Fibrin Sealant on Skin Graft Tissue Adhesion in a Rodent Model.

PubMed

Balceniuk, Mark D; Wingate, Nicholas A; Krein, Howard; Curry, Joseph; Cognetti, David; Heffelfiner, Ryan; Luginbuhl, Adam

2016-07-01

To establish a rodent model for skin grafting with fibrin glue and examine the effects of fibrin glue on the adhesive strength of skin grafts without bolsters. Animal cohort. Academic hospital laboratory. Three skin grafts were created using a pneumatic microtome on the dorsum of 12 rats. Rats were evenly divided into experimental (n = 6) and control (n = 6) groups. The experimental group received a thin layer of fibrin glue between the graft and wound bed, and the control group was secured with standard bolsters. Adherence strength of the skin graft was tested by measurement of force required to sheer the graft from the recipient wound. Adhesion strength measurements were taken on postoperative days (PODs) 1, 2, and 3. The experimental group required an average force of 719 g on POD1, 895 g on POD2, and 676 g on POD3, while the average force in the control group was 161 g on POD1, 257 g on POD2, and 267 g on POD3. On each of the 3 PODs, there was a significant difference in adherence strength between the experimental and control groups (P = .036, P = .029, P = .024). There is a significant difference in the adhesion strength of skin grafts to the wound bed in the early postoperative period of the 2 groups. In areas of high mobility, using the fibrin sealant can keep the graft immobile during the critical phases of early healing. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Dissociable changes in functional network topology underlie early category learning and development of automaticity

PubMed Central

Soto, Fabian A.; Bassett, Danielle S.; Ashby, F. Gregory

2016-01-01

Recent work has shown that multimodal association areas–including frontal, temporal and parietal cortex–are focal points of functional network reconfiguration during human learning and performance of cognitive tasks. On the other hand, neurocomputational theories of category learning suggest that the basal ganglia and related subcortical structures are focal points of functional network reconfiguration during early learning of some categorization tasks, but become less so with the development of automatic categorization performance. Using a combination of network science and multilevel regression, we explore how changes in the connectivity of small brain regions can predict behavioral changes during training in a visual categorization task. We find that initial category learning, as indexed by changes in accuracy, is predicted by increasingly efficient integrative processing in subcortical areas, with higher functional specialization, more efficient integration across modules, but a lower cost in terms of redundancy of information processing. The development of automaticity, as indexed by changes in the speed of correct responses, was predicted by lower clustering (particularly in subcortical areas), higher strength (highest in cortical areas) and higher betweenness centrality. By combining neurocomputational theories and network scientific methods, these results synthesize the dissociative roles of multimodal association areas and subcortical structures in the development of automaticity during category learning. PMID:27453156

PubMed Central

CICIRIELLO, E.; BOLZONELLO, P.; MARCHI, R.; FALZONE, C.; MUZZI, E.

2016-01-01

SUMMARY The latest international guidelines highlight the importance of involving the family in the diagnositic and rehabilitation process of children affected by permanent hearing impairment. This emphasises how meaningful this approach is for the development of the deaf child. So far, there is very little evidence about this approach in Italy, and there are still some barriers to its practical management. The aim of this paper is to report the results of a strategic analysis, which identifies the strengths, weaknesses, opportunities and threats of the family empowerment process during early auditory diagnosis and rehabilitation. The audiology programme should have the goal to offer information and support to families in order to achieve a conscious decision about the use and type of auditory prosthesis and rehabilitation choice within three months after audiologic diagnosis. Within the framework of the Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children", a group of professionals identified three main recommendations that can be useful to foster the natural communicative development of the child by strengthening the therapeutic alliance and empowerment of the family. The recommendations obtained with this analysis can help to develop new Italian guidelines with the aim to foster natural communicative development of the child by strengthening the therapeutic alliance and empowerment of the family. PMID:27054393

The Strength of Selection against Neanderthal Introgression

PubMed Central

Juric, Ivan

2016-01-01

Hybridization between humans and Neanderthals has resulted in a low level of Neanderthal ancestry scattered across the genomes of many modern-day humans. After hybridization, on average, selection appears to have removed Neanderthal alleles from the human population. Quantifying the strength and causes of this selection against Neanderthal ancestry is key to understanding our relationship to Neanderthals and, more broadly, how populations remain distinct after secondary contact. Here, we develop a novel method for estimating the genome-wide average strength of selection and the density of selected sites using estimates of Neanderthal allele frequency along the genomes of modern-day humans. We confirm that East Asians had somewhat higher initial levels of Neanderthal ancestry than Europeans even after accounting for selection. We find that the bulk of purifying selection against Neanderthal ancestry is best understood as acting on many weakly deleterious alleles. We propose that the majority of these alleles were effectively neutral—and segregating at high frequency—in Neanderthals, but became selected against after entering human populations of much larger effective size. While individually of small effect, these alleles potentially imposed a heavy genetic load on the early-generation human–Neanderthal hybrids. This work suggests that differences in effective population size may play a far more important role in shaping levels of introgression than previously thought. PMID:27824859

The level and nature of autistic intelligence II: what about Asperger syndrome?

PubMed

Soulières, Isabelle; Dawson, Michelle; Gernsbacher, Morton Ann; Mottron, Laurent

2011-01-01

A distinctively uneven profile of intelligence is a feature of the autistic spectrum. Within the spectrum, Asperger individuals differ from autistics in their early speech development and in being less likely to be characterized by visuospatial peaks. While different specific strengths characterize different autistic spectrum subgroups, all such peaks of ability have been interpreted as deficits: isolated, aberrant, and irreconcilable with real human intelligence. This view has recently been challenged by findings of autistic strengths in performance on Raven's Progressive Matrices (RPM), an important marker of general and fluid intelligence. We investigated whether these findings extend to Asperger syndrome, an autistic spectrum subgroup characterized by verbal peaks of ability, and whether the cognitive mechanisms underlying autistic and Asperger RPM performance differ. Thirty-two Asperger adults displayed a significant advantage on RPM over Wechsler Full-Scale and Performance scores relative to their typical controls, while in 25 Asperger children an RPM advantage was found over Wechsler Performance scores only. As previously found with autistics, Asperger children and adults achieved RPM scores at a level reflecting their Wechsler peaks of ability. Therefore, strengths in RPM performance span the autistic spectrum and imply a common mechanism advantageously applied to different facets of cognition. Autistic spectrum intelligence is atypical, but also genuine, general, and underestimated.

The Level and Nature of Autistic Intelligence II: What about Asperger Syndrome?

PubMed Central

Soulières, Isabelle; Dawson, Michelle; Gernsbacher, Morton Ann; Mottron, Laurent

2011-01-01

A distinctively uneven profile of intelligence is a feature of the autistic spectrum. Within the spectrum, Asperger individuals differ from autistics in their early speech development and in being less likely to be characterized by visuospatial peaks. While different specific strengths characterize different autistic spectrum subgroups, all such peaks of ability have been interpreted as deficits: isolated, aberrant, and irreconcilable with real human intelligence. This view has recently been challenged by findings of autistic strengths in performance on Raven's Progressive Matrices (RPM), an important marker of general and fluid intelligence. We investigated whether these findings extend to Asperger syndrome, an autistic spectrum subgroup characterized by verbal peaks of ability, and whether the cognitive mechanisms underlying autistic and Asperger RPM performance differ. Thirty-two Asperger adults displayed a significant advantage on RPM over Wechsler Full-Scale and Performance scores relative to their typical controls, while in 25 Asperger children an RPM advantage was found over Wechsler Performance scores only. As previously found with autistics, Asperger children and adults achieved RPM scores at a level reflecting their Wechsler peaks of ability. Therefore, strengths in RPM performance span the autistic spectrum and imply a common mechanism advantageously applied to different facets of cognition. Autistic spectrum intelligence is atypical, but also genuine, general, and underestimated. PMID:21991394

Outcome of Low-Invasive Local Split-Thickness Lengthening for Iliotibial Band Friction Syndrome.

PubMed

Inoue, Hiroaki; Hara, Kunio; Arai, Yuji; Nakagawa, Shuji; Kan, Hiroyuki; Hino, Manabu; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2018-02-01

Conventional surgical methods for iliotibial band friction syndrome (ITBFS) may affect the iliotibial band (ITB), delaying return to sports activities or impeding performance. We have developed a minimally invasive method. This study retrospectively analyzed the outcomes of this procedure in individuals with ITBFS. This study included 34 knees of 31 individuals. Surgery involved lengthening the central part of the ITB by splitting it into a superficial and a deep layer, maintaining the anterior and posterior fibers immediately above the lateral epicondyle. Outcomes included time to resume sports activity, personal best times to run a 5000-m race before and after surgery, and 2-month post-surgery muscle strengths. The mean postoperative time to return to competition was 5.8 weeks. Personal best times of 5000-m race improved in 13 of 17 runners. Two months post-surgery, the mean extensor muscle strengths on the healthy and affected sides did not significantly differ nor did the flexor muscle strengths. In ITBFS, the ITB itself is normal. Lengthening the limited region of the ITB immediately above the lateral femoral epicondyle removes the cause of ITBFS, with a reduction in inflammation. This technique resulted in early return to competition without degrading performance. © Georg Thieme Verlag KG Stuttgart · New York.

Cultural and historical trends and influences of food, nutrition and cuisine on health and development.

PubMed

Erlich, Rita

2004-01-01

The distinctive qualities of the cuisine of Hangzhou are the result of its geographical situation, which provided good soils, reliable rainfall, a lake that has been a water source and renowned beauty spot for centuries. The rich water-sources facilitated the development of gastronomy, agriculture, trade and administration, especially after it became the capital of the Southern Sung Dynasty. Hangzhou's food sources are especially diverse, notably for fish, green vegetables, fungi, and tofu, and have been since early records. As capital, it became a leader in cuisine, and in the development of the restaurant industry. The strength of food traditions has been reinforced constantly by the cultural, medicinal, nutritional, and social values of food and cooking, by the interest of Chinese scholars in food and wine, and by the narrative that accompanies specific dishes.

Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes.

PubMed

Khorshidi, Hooman; Raoofi, Saeed; Bagheri, Rafat; Banihashemi, Hodasadat

2016-01-01

Objectives. The mechanical properties of membranes are important factors in the success of treatment and clinical handling. The goal of this study was to compare the mechanical properties of early leukocyte- and platelet-rich fibrin (L-PRF) versus PRGF/Endoret membrane. Materials and Methods. In this experimental study, membranes were obtained from 10 healthy male volunteers. After obtaining 20 cc venous blood from each volunteer, 10 cc was used to prepare early L-PRF (group 1) and the rest was used to get a membrane by PRGF-Endoret system (group 2). Tensile loads were applied to specimens using universal testing machine. Tensile strength, stiffness, and toughness of the two groups of membranes were calculated and compared by paired t-test. Results. The mean tensile strength and toughness were higher in group 1 with a significant difference (P < 0.05). The mean stiffness in group 1 was also higher but not statistically significant (P > 0.05). Conclusions. The results showed that early L-PRF membranes had stronger mechanical properties than membranes produced by PRGF-Endoret system. Early L-PRF membranes might have easier clinical handling and could be a more proper scaffold in periodontal regenerative procedures. The real results of the current L-PRF should be in fact much higher than what is reported here.

Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes

PubMed Central

Khorshidi, Hooman; Raoofi, Saeed; Bagheri, Rafat; Banihashemi, Hodasadat

2016-01-01

Objectives. The mechanical properties of membranes are important factors in the success of treatment and clinical handling. The goal of this study was to compare the mechanical properties of early leukocyte- and platelet-rich fibrin (L-PRF) versus PRGF/Endoret membrane. Materials and Methods. In this experimental study, membranes were obtained from 10 healthy male volunteers. After obtaining 20 cc venous blood from each volunteer, 10 cc was used to prepare early L-PRF (group 1) and the rest was used to get a membrane by PRGF-Endoret system (group 2). Tensile loads were applied to specimens using universal testing machine. Tensile strength, stiffness, and toughness of the two groups of membranes were calculated and compared by paired t-test. Results. The mean tensile strength and toughness were higher in group 1 with a significant difference (P < 0.05). The mean stiffness in group 1 was also higher but not statistically significant (P > 0.05). Conclusions. The results showed that early L-PRF membranes had stronger mechanical properties than membranes produced by PRGF-Endoret system. Early L-PRF membranes might have easier clinical handling and could be a more proper scaffold in periodontal regenerative procedures. The real results of the current L-PRF should be in fact much higher than what is reported here. PMID:26880919

Building partnership in oral cancer research in a developing country: processes and barriers.

PubMed

Zain, Rosnah Binti; Ghani, Wan Maria Nabillah; Razak, Ishak Abdul; Latifah, Raja Jallaludin Raja; Samsuddin, Abdul Rani; Cheong, Sok Ching; Abdullah, Norlida; Ismail, Abdul Rashid; Hussaini, Haizal Bin; Talib, Norain Abu; Jallaludin, Amin

2009-01-01

The rising burden of cancer in the developing world calls for a re-evaluation of the treatment strategies employed to improve patient management, early detection and understanding of the disease. There is thus an increasing demand for interdisciplinary research that integrates two or more disciplines of what may seemed to be highly unrelated and yet very much needed as strategies for success in research. This paper presents the processes and barriers faced in building partnerships in oral cancer research in a developing country. A case study was undertaken in a developing country (Malaysia) to assess the strengths and weaknesses of the situation leading to the formation of a multidisciplinary research partnership in oral cancer. Following the formalization of the partnership, further evaluation was undertaken to identify measures that can assist in sustaining the partnership. The group identifies its strength as the existence of academia, research-intensive NGOs and good networking of clinicians via the existence of the government's network of healthcare provider system who are the policy makers. The major weaknesses identified are the competing interest between academia and NGOs to justify their existence due to the lack of funding sources and well trained human resources. With the growing partnership, the collaborative group recognizes the need to develop standard operating procedures (SOPs) and guidelines for the sharing and usage of resources in order to safeguard the interest of the original partners while also attending to the needs of the new partners.

Long-life slab replacement concrete.

DOT National Transportation Integrated Search

2015-03-01

This research was initiated following reports of high incidence of cracking on FDOT concrete pavement replacement : slab projects. Field slabs were instrumented for data acquisition from high-early-strength concrete pavement : replacement slabs place...

Acceptable vibrations on green concrete.

DOT National Transportation Integrated Search

2013-12-01

Vibrations are potentially harmful to green concrete in shaft foundations, and many states, including : Mississippi, cautiously established limits in terms of compressive strength, distance boundary, and : wait time to protect early age concrete. But...

Motor development from 4 to 8 months corrected age in infants born at or less than 29 weeks' gestation.

PubMed

Pin, Tamis W; Darrer, Tanya; Eldridge, Bev; Galea, Mary P

2009-09-01

Clinically, preterm infants show motor delay and atypical postures compared with their peers born at term. A longitudinal cohort study was designed to describe the motor development of very preterm infants from 4 to 18 months corrected age (CA). The study was also designed to investigate how the atypical postures observed in early infancy in the preterm infants might be related to their later motor development. Here we report the findings in early motor skills from 4 to 8 months CA. Early motor skills were assessed in 62 preterm infants (32 males, 30 females, mean gestation 26.94wks, SD 1.11) and 53 term infants (32 males, 21 females, mean gestation 39.55wks, SD 1.17) using the Alberta Infant Motor Scale (AIMS). The preterm infants demonstrated different motor behaviours from their term peers, with an uneven progression of motor skills in different positions from 4 to 8 months CA. At 8 months CA, 90%of the term infants were able to sit without arm support, but only 56%of the preterm infants could maintain sitting very briefly without arm support. This uneven progression may have been due to an imbalance between the active flexor and extensor strength and hence inadequate postural control in these positions. The AIMS has also been shown to be a valid assessment tool to demonstrate unique characteristics in movement quality in the preterm population.

Early life stress is associated with default system integrity and emotionality during infancy.

PubMed

Graham, Alice M; Pfeifer, Jennifer H; Fisher, Philip A; Carpenter, Samuel; Fair, Damien A

2015-11-01

Extensive animal research has demonstrated the vulnerability of the brain to early life stress (ELS) with consequences for emotional development and mental health. However, the influence of moderate and common forms of stress on early human brain development is less well-understood and precisely characterized. To date, most work has focused on severe forms of stress, and/or on brain functioning years after stress exposure. In this report we focused on conflict between parents (interparental conflict), a common and relatively moderate form of ELS that is highly relevant for children's mental health outcomes. We used resting state functional connectivity MRI to examine the coordinated functioning of the infant brain (N = 23; 6-12-months-of-age) in the context of interparental conflict. We focused on the default mode network (DMN) due to its well-characterized developmental trajectory and implications for mental health. We further examined DMN strength as a mediator between conflict and infants' negative emotionality. Higher interparental conflict since birth was associated with infants showing stronger connectivity between two core DMN regions, the posterior cingulate cortex (PCC) and the anterior medial prefrontal cortex (aMPFC). PCC to amygdala connectivity was also increased. Stronger PCC-aMPFC connectivity mediated between higher conflict and higher negative infant emotionality. The developing DMN may be an important marker for effects of ELS with relevance for emotional development and subsequent mental health. Increasing understanding of the associations between common forms of family stress and emerging functional brain networks has potential to inform intervention efforts to improve mental health outcomes. © 2015 Association for Child and Adolescent Mental Health.

Early life stress is associated with default system integrity and emotionality during infancy

PubMed Central

Graham, Alice M.; Pfeifer, Jennifer H.; Fisher, Philip A.; Carpenter, Samuel; Fair, Damien A.

2015-01-01

Background Extensive animal research has demonstrated the vulnerability of the brain to early life stress (ELS) with consequences for emotional development and mental health. However, the influence of moderate and common forms of stress on early human brain development is less well understood and precisely characterized. To date, most work has focused on severe forms of stress, and/or on brain functioning years after stress exposure. Methods In this report we focused on conflict between parents (interparental conflict), a common and relatively moderate form of ELS that is highly relevant for children's mental health outcomes. We used resting state functional connectivity MRI to examine the coordinated functioning of the infant brain (N=23; 6–12-months-of-age) in the context of interparental conflict. We focused on the default mode network (DMN) due to its well characterized developmental trajectory and implications for mental health. We further examined DMN strength as a mediator between conflict and infants’ negative emotionality. Results Higher interparental conflict since birth was associated with infants showing stronger connectivity between two core DMN regions, the posterior cingulate cortex (PCC) and the anterior medial prefrontal cortex (aMPFC). PCC to amygdala connectivity was also increased. Stronger PCC-aMPFC connectivity mediated between higher conflict and higher negative infant emotionality. Conclusions The developing DMN may be an important marker for effects of ELS with relevance for emotional development and subsequent mental health. Increasing understanding of the associations between common forms of family stress and emerging functional brain networks has potential to inform intervention efforts to improve mental health outcomes. PMID:25809052

Physicomechanical, In Vitro and In Vivo Performance of 3D Printed Doped Tricalcium Phosphate Scaffolds for Bone Tissue Engineering and Drug Delivery

NASA Astrophysics Data System (ADS)

Tarafder, Solaiman

Although tricalcium phosphate (TCP) is widely used in bone tissue engineering, the strength degradation kinetics is not well controlled. This study focuses on the underlying mechanism of strength degradation kinetics by incorporating trace elements in TCP. The objective of this research is to modify the mechanical properties of TCP to achieve the desired degradation rate for the specific need, and improve the in vivo bioactivity for early wound healing by incorporating trace elements such as strontium (Sr2+), magnesium (Mg2+) and silicon (Si4+) as dopants. The hypothesis of this research is that the presence of different trace elements in TCP will influence its phase stability, microstructure, mechanical strength, and both in vitro and in vivo bioactivity. Direct three dimensional printing (3DP) was used to fabricate designed interconnected macroporous pure and doped TCP scaffolds. Microwave sintering as opposed to conventional sintering was also used for better densification and higher mechanical strength. A maximum compressive strength of 10.95 +/- 1.28 MPa and 12.01 +/- 1.56 MPa were achieved for pure and Sr2+-Mg2+ doped TCP scaffolds with 500 microm designed pores (˜400 microm after sintering) sintered in microwave furnace, respectively. Substitution of Mg2+ and Sr2+ into calcium (Ca2+) sites of TCP crystal lattice contributed to phase stability and controlled gradual degradation. On the other hand, Si4+ substitution into phosphorous (P5+) sites destabilized the crystal structure and accelerated degradation of TCP. Interconnected macroporous beta-TCP scaffolds facilitated in vivo guided bone tissue regeneration through infiltration of cells and extracellular matrix into the designed pores. Presence of Sr2+, Mg2+ and Si4+ into beta-TCP induced increased in vivo early bone formation and better bone remodeling through increased extracellular matrix production such as, collagen and osteocalcin, when tested in rat and rabbit distal femur model. The presence of Si4+ along with Mg 2+ induced increased new blood vessel formation. Our results exhibited that Sr2+, Mg2+ and Si4+ doped 3DP TCP scaffolds have strong potential in bone tissue engineering applications for early wound healing.

Building Yolŋu Skills, Knowledge, and Priorities into Early Childhood Assessment and Support: Protocol for a Qualitative Study

PubMed Central

Maypilama, Elaine Lawurrpa; Fasoli, Lyn; Gundjarranbuy, Rosemary; Godwin-Thompson, Jenine; Guyula, Abbey; Yunupiŋu, Megan; Armstrong, Emily; Garrutju, Jane; McEldowney, Rose

2018-01-01

Background Yolngu or Yolŋu are a group of indigenous Australian people inhabiting north-eastern Arnhem Land in the Northern Territory of Australia. Recent government policy addressing disparities in outcomes between Indigenous and other children in Australia has resulted in the rapid introduction of early childhood interventions in remote Aboriginal communities. This is despite minimal research into their appropriateness or effectiveness for these contexts. Objective This research aims to privilege Aboriginal early childhood knowledge, priorities and practices and to strengthen the evidence base for culturally responsive and relevant assessment processes and support that distinguishes “difference” from “deficit” to facilitate optimal child development. Methods This collaborative qualitative research employs video ethnography, participant observation and in-depth interviews, involving Aboriginal families and researchers in design, implementation, interpretation and dissemination using a locally developed, culturally responsive research approach. Longitudinal case studies are being conducted with 6 families over 5 years and emerging findings are being explored with a further 50 families and key community informants. Data from all sources are analyzed inductively using a collaborative and iterative process. The study findings, grounded in an in-depth understanding of the cultural context of the study but with relevance to policy and practice more widely, are informing the development of a Web-based educational resource and targeted knowledge exchange activities. Results This paper focuses only on the research approach used in this project. The findings will be reported in detail in future publications. In response to community concerns about lack of recognition of Aboriginal early childhood strengths, priorities and knowledge, this collaborative community-driven project strengthens the evidence base for developing culturally responsive and relevant early childhood services and assessment processes to support optimal child development. The study findings are guiding the development of a Web-based educational resource for staff working with Aboriginal communities and families in the field of early child development. This website will also function as a community-developed tool for strengthening and maintaining Aboriginal knowledge and practice related to child development and child rearing. It will be widely accessible to community members through a range of platforms (eg, mobile phones and tablets) and will provide a model for other cultural contexts. Conclusions This project will facilitate wider recognition and reflection of cultural knowledge and practice in early childhood programs and policies and will support strengthening and maintenance of cultural knowledge. The culturally responsive and highly collaborative approach to community-based research on which this project is based will also inform future research through sharing knowledge about the research process as well as research findings. PMID:29514777

Searching for primordial magnetic fields with CMB B-modes

NASA Astrophysics Data System (ADS)

Pogosian, Levon; Zucca, Alex

2018-06-01

Was the primordial universe magnetized? The answer to this question would help explain the origin of micro-Gauss strength magnetic fields observed in galaxies. It is also of fundamental importance in developing a complete theory of the early universe. While there can be other signatures of cosmological magnetic fields, a signature in the cosmic microwave background (CMB) would prove their primordial origin. The B-mode polarization of CMB is particularly promising in this regard because there are relatively few other sources of B-modes, and because the vortical modes sourced by the primordial magnetic field (PMF) survive diffusion damping up to a small fraction of the Silk length. At present, the Planck temperature and polarization spectra combined with the B-mode spectrum measured by the South Pole Telescope (SPT) constrain the PMF strength to be no more than  ∼1 nano-Gauss (nG). Because of the quartic scaling of the CMB anisotropy spectra with the PMF strength, this bound will not change by much even with the significantly better measurements of the B-mode spectrum by the Stage III and Stage IV CMB experiments. On the other hand, tightening the bound well below the 1 nG threshold would rule out the purely primordial origin (requiring no dynamo action) of galactic fields. Considering Faraday rotation, which converts some of the E-modes into B-modes and scales linearly with the field strength, will help to achieve this goal. As we demonstrate, the upcoming experiments, such as SPT-3G and the Simons Observatory, will be sensitive to fields of  ∼0.5 nG strength thanks to the mode-coupling signature induced by Faraday rotation. A future Stage IV ground based experiment or a space probe will be capable of probing fields below 0.1 nG, and would detect a scale-invariant PMF of 0.2 nG strength without de-lensing or subtracting the galactic rotation measure.

Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish.

PubMed

Ingley, Spencer J; Johnson, Jerald B

2016-03-01

How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time. © 2016 The Author(s).

Seismic Monitoring of Permafrost During Controlled Thaw: An Active-Source Experiment Using a Surface Orbital Vibrator and Fiber-Optic DAS Arrays

NASA Astrophysics Data System (ADS)

Dou, S.; Wood, T.; Lindsey, N.; Ajo Franklin, J. B.; Freifeld, B. M.; Gelvin, A.; Morales, A.; Saari, S.; Ekblaw, I.; Wagner, A. M.; Daley, T. M.; Robertson, M.; Martin, E. R.; Ulrich, C.; Bjella, K.

2016-12-01

Thawing of permafrost can cause ground deformations that threaten the integrity of civil infrastructure. It is essential to develop early warning systems that can identify critically warmed permafrost and issue warnings for hazard prevention and control. Seismic methods can play a pivotal role in such systems for at least two reasons: First, seismic velocities are indicative of mechanical strength of the subsurface and thus are directly relevant to engineering properties; Second, seismic velocities in permafrost systems are sensitive to pre-thaw warming, which makes it possible to issue early warnings before the occurrence of hazardous subsidence events. However, several questions remain: What are the seismic signatures that can be effectively used for early warning of permafrost thaw? Can seismic methods provide enough warning times for hazard prevention and control? In this study, we investigate the feasibility of using permanently installed seismic networks for early warnings of permafrost thaw. We conducted continuous active-source seismic monitoring of permafrost that was under controlled heating at CRREL's Fairbanks permafrost experiment station. We used a permanently installed surface orbital vibrator (SOV) as source and surface-trenched DAS arrays as receivers. The SOV is characterized by its excellent repeatability, automated operation, high energy level, and the rich frequency content (10-100 Hz) of the generated wavefields. The fiber-optic DAS arrays allow continuous recording of seismic data with dense spatial sampling (1-meter channel spacing), low cost, and low maintenance. This combination of SOV-DAS provides unique seismic datasets for observing time-lapse changes of warming permafrost at the field scale, hence providing an observational basis for design and development of early warning systems for permafrost thaw.

Losing grip: Senescent decline in physical strength in a small-bodied primate in captivity and in the wild.

PubMed

Hämäläinen, Anni; Dammhahn, Melanie; Aujard, Fabienne; Kraus, Cornelia

2015-01-01

Muscle strength reflects physical functioning, declines at old age and predicts health and survival in humans and laboratory animals. Age-associated muscle deterioration causes loss of strength and may impair fitness of wild animals. However, the effects of age and life-history characteristics on muscle strength in wild animals are unknown. We investigated environment- and sex-specific patterns of physical functioning by measuring grip strength in wild and captive gray mouse lemurs. We expected more pronounced strength senescence in captivity due to condition-dependent, extrinsic mortality found in nature. Males were predicted to be stronger but potentially experience more severe senescence than females as predicted by life history theory. We found similar senescent declines in captive males and females as well as wild females, whereas wild males showed little decline, presumably due to their early mortality. Captive animals were generally weaker and showed earlier declines than wild animals. Unexpectedly, females tended to be stronger than males, especially in the reproductive season. Universal intrinsic mechanisms (e.g. sarcopenia) likely cause the similar patterns of strength loss across settings. The female advantage in muscle strength merits further study; it may follow higher reproductive investment by males, or be an adaptation associated with female social dominance. Copyright © 2014 Elsevier Inc. All rights reserved.

The underlying number-space mapping among kindergarteners and its relation with early numerical abilities.

PubMed

Chan, Winnie Wai Lan; Wong, Terry Tin-Yau

2016-08-01

People map numbers onto space. The well-replicated SNARC (spatial-numerical association of response codes) effect indicates that people have a left-sided bias when responding to small numbers and a right-sided bias when responding to large numbers. This study examined whether such spatial codes were tagged to the ordinal or magnitude information of numbers among kindergarteners and whether it was related to early numerical abilities. Based on the traditional magnitude judgment task, we developed two variant tasks-namely the month judgment task and dot judgment task-to elicit ordinal and magnitude processing of numbers, respectively. Results showed that kindergarteners oriented small numbers toward the left side and large numbers toward the right side when processing the ordinal information of numbers in the month judgment task but not when processing the magnitude information in the number judgment task and dot judgment task, suggesting that the left-to-right spatial bias was probably tagged to the ordinal but not magnitude property of numbers. Moreover, the strength of the SNARC effect was not related to early numerical abilities. These findings have important implications for the early spatial representation of numbers and its role in numerical performance among kindergarteners. Copyright © 2016 Elsevier Inc. All rights reserved.

Solid-State Lighting Module (SSLM)

NASA Technical Reports Server (NTRS)

2008-01-01

The project's goal was to build a light-emitting-diode (LED)-based light fixture that is identical in fit, form, and function to the existing International Space Station (ISS) General Luminaire Assembly (GLA) light fixture and fly it on the ISS in early FY 2008 as a Station Detailed Test Objective (SDTO). Our design offers the following strengths: proven component hardware: Our design uses components flown in other KSC-developed hardware; heat path thermal pad: LED array heat is transferred from the circuit board by silicon pad, negating the need for a cooling fan; variable colorimetry: The output light color can be changed by inserting different LED combinations.

Space Charge Modulated Electrical Breakdown

PubMed Central

Li, Shengtao; Zhu, Yuanwei; Min, Daomin; Chen, George

2016-01-01

Electrical breakdown is one of the most important physical phenomena in electrical and electronic engineering. Since the early 20th century, many theories and models of electrical breakdown have been proposed, but the origin of one key issue, that the explanation for dc breakdown strength being twice or higher than ac breakdown strength in insulating materials, remains unclear. Here, by employing a bipolar charge transport model, we investigate the space charge dynamics in both dc and ac breakdown processes. We demonstrate the differences in charge accumulations under both dc and ac stresses and estimate the breakdown strength, which is modulated by the electric field distortion induced by space charge. It is concluded that dc breakdown initializes in the bulk whereas ac breakdown initializes in the vicinity of the sample-electrode interface. Compared with dc breakdown, the lower breakdown strength under ac stress and the decreasing breakdown strength with an increase in applied frequency, are both attributed to the electric field distortion induced by space charges located in the vicinity of the electrodes. PMID:27599577

Postural complexity influences development in infants born preterm with brain injury: relating perception-action theory to 3 cases.

PubMed

Dusing, Stacey C; Izzo, Theresa; Thacker, Leroy R; Galloway, James Cole

2014-10-01

Perception-action theory suggests a cyclical relationship between movement and perceptual information. In this case series, changes in postural complexity were used to quantify an infant's action and perception during the development of early motor behaviors. Three infants born preterm with periventricular white matter injury were included. Longitudinal changes in postural complexity (approximate entropy of the center of pressure), head control, reaching, and global development, measured with the Test of Infant Motor Performance and the Bayley Scales of Infant and Toddler Development, were assessed every 0.5 to 3 months during the first year of life. All 3 infants demonstrated altered postural complexity and developmental delays. However, the timing of the altered postural complexity and the type of delays varied among the infants. For infant 1, reduced postural complexity or limited action while learning to control her head in the midline position may have contributed to her motor delay. However, her ability to adapt her postural complexity eventually may have supported her ability to learn from her environment, as reflected in her relative cognitive strength. For infant 2, limited early postural complexity may have negatively affected his learning through action, resulting in cognitive delay. For infant 3, an increase in postural complexity above typical levels was associated with declining neurological status. Postural complexity is proposed as a measure of perception and action in the postural control system during the development of early behaviors. An optimal, intermediate level of postural complexity supports the use of a variety of postural control strategies and enhances the perception-action cycle. Either excessive or reduced postural complexity may contribute to developmental delays in infants born preterm with white matter injury. © 2014 American Physical Therapy Association.

Ab Initio Study of the Electric Dipole Transition Moment for the Electronic X to C Transition in Acetylene: Theoretical Predictions of the Absorption and Magnetic Circular Dichroism Intensities

DTIC Science & Technology

1990-12-01

Symmetric C-C Stretch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6. MCQ Intensities and Oscillator Strengths...chemical approach, but only at the SCF level , to predict an absorption oscillator strength of 0.072 for the (vertical) CE-X transition. An early...fact that the lower v’ levels agree better with experiment than the higher v’ levels suggests increasing inaccuracies in the Franck-Condon overlap with

Pleas'd by a Newe Inuention?: Assessing the Impact of "Early English Books Online" on Teaching and Research at the University of Colorado at Boulder

ERIC Educational Resources Information Center

Lindquist, Thea; Wicht, Heather

2007-01-01

The authors conducted a study of the use of "Early English Books Online" (EEBO) in research and teaching at one institution. The findings highlight the strengths and weaknesses of EEBO for research and teaching and the importance of librarian-faculty collaboration in instructing students to use large, electronic full-text primary-source…

Sensitivity of coral recruitment to subtle shifts in early community succession.

PubMed

Doropoulos, Christopher; Roff, George; Visser, Mart-Simone; Mumby, Peter J

2017-02-01

Community succession following disturbance depends on positive and negative interactions, the strength of which change along environmental gradients. To investigate how early succession affects coral reef recovery, we conducted an 18-month experiment in Palau, using recruitment tiles and herbivore exclusion cages. One set of reefs has higher wave exposure and had previously undergone a phase shift to macroalgae following a major typhoon, whereas the other set of reefs have lower wave exposure and did not undergo a macroalgal phase shift. Similar successional trajectories were observed at all sites when herbivores were excluded: turf algae dominated early succession, followed by shifts to foliose macroalgae and heterotrophic invertebrates. However, trajectories differed in the presence of herbivores. At low wave exposure reefs, herbivores promoted coralline algae and limited turf and encrusting fleshy algae in crevice microhabitats, facilitating optimal coral recruitment. Under medium wave exposure, relatively higher but still low coverage of turf and encrusting fleshy algae (15-25%) found in crevice microhabitats inhibited coral recruitment, persisting throughout multiple recruitment events. Our results indicate that altered interaction strength in different wave environments following disturbance can drive subtle changes in early succession that cascade to alter secondary succession to coral recruitment and system recovery. © 2016 by the Ecological Society of America.

DSM-III: the major achievements and an overview.

PubMed

Spitzer, R L; Williams, J B; Skodol, A E

1980-02-01

DSM-III will be published early this year. In the first part of this article the authors describe some of the major achievements of DSM-III: the process of its development, reaching consensus on many controversial diagnostic categories and a definition of mental disorder, the provision of diagnostic criteria and a multiaxial evaluation system, and the demonstration of improved diagnostic reliability. In the second part of the article the authors present an overview of DSM-III in which they describe its departures from DSM-II and the reasons for these changes. They conclude that in the next few years there should be systematic study of DSM-III in use, so that information about its strengths and limitations can be made available to those responsible for developing DSM-IV.

The strengths and weaknesses in verbal short-term memory and visual working memory in children with hearing impairment and additional language learning difficulties.

PubMed

Willis, Suzi; Goldbart, Juliet; Stansfield, Jois

2014-07-01

To compare verbal short-term memory and visual working memory abilities of six children with congenital hearing-impairment identified as having significant language learning difficulties with normative data from typically hearing children using standardized memory assessments. Six children with hearing loss aged 8-15 years were assessed on measures of verbal short-term memory (Non-word and word recall) and visual working memory annually over a two year period. All children had cognitive abilities within normal limits and used spoken language as the primary mode of communication. The language assessment scores at the beginning of the study revealed that all six participants exhibited delays of two years or more on standardized assessments of receptive and expressive vocabulary and spoken language. The children with hearing-impairment scores were significantly higher on the non-word recall task than the "real" word recall task. They also exhibited significantly higher scores on visual working memory than those of the age-matched sample from the standardized memory assessment. Each of the six participants in this study displayed the same pattern of strengths and weaknesses in verbal short-term memory and visual working memory despite their very different chronological ages. The children's poor ability to recall single syllable words in relation to non-words is a clinical indicator of their difficulties in verbal short-term memory. However, the children with hearing-impairment do not display generalized processing difficulties and indeed demonstrate strengths in visual working memory. The poor ability to recall words, in combination with difficulties with early word learning may be indicators of children with hearing-impairment who will struggle to develop spoken language equal to that of their normally hearing peers. This early identification has the potential to allow for target specific intervention that may remediate their difficulties. Copyright © 2014. Published by Elsevier Ireland Ltd.

Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

PubMed

Sabido, Rafael; Hernández-Davó, Jose Luis; Botella, Javier; Moya, Manuel

2016-01-01

To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

The changing strength and nature of fire-climate relationships in the northern Rocky Mountains, U.S.A., 1902-2008

USGS Publications Warehouse

Littell, Jeremy

2015-01-01

Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable forested regions of the western U.S.A. Fire-danger and water-balance metrics yielded the best combination of calibration accuracy and predictive skill in modeling annual area burned. The strength of fire-climate relationships varied markedly at multi-decadal scales, with models explaining < 40% to 88% of the variation in annual area burned. The early 20th century (1902-1942) and the most recent two decades (1985-2008) exhibited strong fire-climate relationships, with weaker relationships for much of the mid 20th century (1943-1984), coincident with diminished burning, less fire-conducive climate, and the initiation of modern fire fighting. Area burned and the strength of fire-climate relationships increased sharply in the mid 1980s, associated with increased temperatures and longer potential fire seasons. Unlike decades with high burning in the early 20th century, models developed using fire-climate relationships from recent decades overpredicted area burned when applied to earlier periods. This amplified response of fire to climate is a signature of altered fire-climate-relationships, and it implicates non-climatic factors in this recent shift. Changes in fuel structure and availability following 40+ yr of unusually low fire activity, and possibly land use, may have resulted in increased fire vulnerability beyond expectations from climatic factors alone. Our results highlight the potential for non-climatic factors to alter fire-climate relationships, and the need to account for such dynamics, through adaptable statistical or processes-based models, for accurately predicting future fire activity.

The Changing Strength and Nature of Fire-Climate Relationships in the Northern Rocky Mountains, U.S.A., 1902-2008

PubMed Central

Higuera, Philip E.; Abatzoglou, John T.; Littell, Jeremy S.; Morgan, Penelope

2015-01-01

Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable forested regions of the western U.S.A. Fire-danger and water-balance metrics yielded the best combination of calibration accuracy and predictive skill in modeling annual area burned. The strength of fire-climate relationships varied markedly at multi-decadal scales, with models explaining < 40% to 88% of the variation in annual area burned. The early 20th century (1902-1942) and the most recent two decades (1985-2008) exhibited strong fire-climate relationships, with weaker relationships for much of the mid 20th century (1943-1984), coincident with diminished burning, less fire-conducive climate, and the initiation of modern fire fighting. Area burned and the strength of fire-climate relationships increased sharply in the mid 1980s, associated with increased temperatures and longer potential fire seasons. Unlike decades with high burning in the early 20th century, models developed using fire-climate relationships from recent decades overpredicted area burned when applied to earlier periods. This amplified response of fire to climate is a signature of altered fire-climate-relationships, and it implicates non-climatic factors in this recent shift. Changes in fuel structure and availability following 40+ yr of unusually low fire activity, and possibly land use, may have resulted in increased fire vulnerability beyond expectations from climatic factors alone. Our results highlight the potential for non-climatic factors to alter fire-climate relationships, and the need to account for such dynamics, through adaptable statistical or processes-based models, for accurately predicting future fire activity. PMID:26114580

The Changing Strength and Nature of Fire-Climate Relationships in the Northern Rocky Mountains, U.S.A., 1902-2008.

PubMed

Higuera, Philip E; Abatzoglou, John T; Littell, Jeremy S; Morgan, Penelope

2015-01-01

Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable forested regions of the western U.S.A. Fire-danger and water-balance metrics yielded the best combination of calibration accuracy and predictive skill in modeling annual area burned. The strength of fire-climate relationships varied markedly at multi-decadal scales, with models explaining < 40% to 88% of the variation in annual area burned. The early 20th century (1902-1942) and the most recent two decades (1985-2008) exhibited strong fire-climate relationships, with weaker relationships for much of the mid 20th century (1943-1984), coincident with diminished burning, less fire-conducive climate, and the initiation of modern fire fighting. Area burned and the strength of fire-climate relationships increased sharply in the mid 1980s, associated with increased temperatures and longer potential fire seasons. Unlike decades with high burning in the early 20th century, models developed using fire-climate relationships from recent decades overpredicted area burned when applied to earlier periods. This amplified response of fire to climate is a signature of altered fire-climate-relationships, and it implicates non-climatic factors in this recent shift. Changes in fuel structure and availability following 40+ yr of unusually low fire activity, and possibly land use, may have resulted in increased fire vulnerability beyond expectations from climatic factors alone. Our results highlight the potential for non-climatic factors to alter fire-climate relationships, and the need to account for such dynamics, through adaptable statistical or processes-based models, for accurately predicting future fire activity.

A systematic review of early intensive intervention for autism spectrum disorders.

PubMed

Warren, Zachary; McPheeters, Melissa L; Sathe, Nila; Foss-Feig, Jennifer H; Glasser, Allison; Veenstra-Vanderweele, Jeremy

2011-05-01

Early intensive behavioral and developmental interventions for young children with autism spectrum disorders (ASDs) may enhance developmental outcomes. To systematically review evidence regarding such interventions for children aged 12 and younger with ASDs. We searched Medline, PsycINFO, and ERIC (Education Resources Information Center) from 2000 to May 2010. Two reviewers independently assessed studies against predetermined inclusion/exclusion criteria. Two reviewers independently extracted data regarding participant and intervention characteristics, assessment techniques, and outcomes and assigned overall quality and strength-of-evidence ratings using predetermined criteria. Thirty-four unique studies met inclusion criteria. Seventeen studies were case series; 2 were randomized controlled trials. We rated 1 study as good quality, 10 as fair quality, and 23 as poor quality. The strength of the evidence overall ranged from insufficient to low. Studies of University of California Los Angeles/Lovaas-based interventions and variants reported clinically significant gains in language and cognitive skills in some children, as did 1 randomized controlled trial of an early intensive developmental intervention approach (the Early Start Denver Model). Specific parent-training approaches yielded gains in short-term language function and some challenging behaviors. Data suggest that subgroups of children displayed more prominent gains across studies, but participant characteristics associated with greater gains are not well understood. Studies of Lovaas-based approaches and early intensive behavioral intervention variants and the Early Start Denver Model resulted in some improvements in cognitive performance, language skills, and adaptive behavior skills in some young children with ASDs, although the literature is limited by methodologic concerns.

Strength Development and Motor-Sports Improvement.

ERIC Educational Resources Information Center

Clarke, H. Harrison, Ed.

1974-01-01

This document examines the effects of strength-development programs on the improvement of motor skills and sports competencies. Part one defines various terms used throughout the development studies. Part two discusses the mixed results of experiments involving speed of movement as the motor item indicative of strength development. Part three…

Is strength of handedness reliable over repeated testing? An examination of typical development and autism spectrum disorder

PubMed Central

Scharoun, Sara M.; Bryden, Pamela J.

2015-01-01

Despite a lack of agreement concerning the age at which adult-like patterns of handedness emerge, it is generally understood that hand preference presents early in life and development is variable. Young children (ages 3–5 years) are described as having weak hand preference; however, older children (ages 7–10 years) display stronger patterns. Here, strength of hand preference refers to reliable use of the preferred hand. In comparison to their typically developing (TD) peers, individuals with autism spectrum disorder (ASD) are described as having a weak hand preference. This study aimed to extend the literature to assess three measures of handedness (Waterloo Handedness Questionnaire – WHQ, Annett pegboard – AP, and WatHand Cabinet Test – WHCT) in two repeated sessions. The first research question aimed to delineate if the strength of hand use changes across testing sessions as a function of age in typical development. Right-handed children reported a reliable preference for the right hand on the WHQ, similar to adults. A marginally significant difference was revealed between 3- to 4- and 5- to 6-year-olds on the AP. This was attributed to weak lateralization in 3- to 4-year-olds, where the establishment of hand preference by age 6 leads to superior performance with the preferred hand in 5- to 6-year-olds. Finally, for the WHCT, 3- to 4-year-olds had the highest bimanual score, indicating use of the same hand to lift the cabinet door and retrieve an object. It is likely that the task was not motorically complex enough to drive preferred hand selection for older participants. The second research question sought to determine if there is difference between (TD) children and children with ASD. No differences were revealed; however, children with ASD did display variable AP performance, providing partial support for previous literature. Findings will be discussed in light of relevant literature. PMID:25691875

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players.

PubMed

Heishman, Aaron D; Curtis, Michael A; Saliba, Ethan N; Hornett, Robert J; Malin, Steven K; Weltman, Arthur L

2017-06-01

Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is suppressed with morning training and is associated with a decrease in self-reported quantity of sleep.

The evolution of surface magnetic fields in young solar-type stars II: the early main sequence (250-650 Myr)

NASA Astrophysics Data System (ADS)

Folsom, C. P.; Bouvier, J.; Petit, P.; Lèbre, A.; Amard, L.; Palacios, A.; Morin, J.; Donati, J.-F.; Vidotto, A. A.

2018-03-01

There is a large change in surface rotation rates of sun-like stars on the pre-main sequence and early main sequence. Since these stars have dynamo-driven magnetic fields, this implies a strong evolution of their magnetic properties over this time period. The spin-down of these stars is controlled by interactions between stellar and magnetic fields, thus magnetic evolution in turn plays an important role in rotational evolution. We present here the second part of a study investigating the evolution of large-scale surface magnetic fields in this critical time period. We observed stars in open clusters and stellar associations with known ages between 120 and 650 Myr, and used spectropolarimetry and Zeeman Doppler Imaging to characterize their large-scale magnetic field strength and geometry. We report 15 stars with magnetic detections here. These stars have masses from 0.8 to 0.95 M⊙, rotation periods from 0.326 to 10.6 d, and we find large-scale magnetic field strengths from 8.5 to 195 G with a wide range of geometries. We find a clear trend towards decreasing magnetic field strength with age, and a power law decrease in magnetic field strength with Rossby number. There is some tentative evidence for saturation of the large-scale magnetic field strength at Rossby numbers below 0.1, although the saturation point is not yet well defined. Comparing to younger classical T Tauri stars, we support the hypothesis that differences in internal structure produce large differences in observed magnetic fields, however for weak-lined T Tauri stars this is less clear.

Explosive Strength of the Knee Extensors: The Influence of Criterion Trial Detection Methodology on Measurement Reproducibility

PubMed Central

Wiesinger, Hans-Peter; Wiemer, Nicolas; Kösters, Alexander; Müller, Erich

2016-01-01

Abstract The present study was conducted to assess test-retest reproducibility of explosive strength measurements during single-joint isometric knee extension using the IsoMed 2000 dynamometer. Thirty-one physically active male subjects (mean age: 23.7 years) were measured on two occasions separated by 48–72 h. The intraclass correlation coefficient (ICC 2,1) and the coefficient of variation (CV) were calculated for (i) maximum torque (MVC), (ii) the peak rate of torque development (RTDpeak) as well as for (iii) the average rate of torque development (RTD) and the impulse taken at several predefined time intervals (0–30 to 0–300 ms); thereby explosive strength variables were derived in two conceptually different versions: on the one hand from the MVC-trial (version I), on the other hand from the trial showing the RTDpeak (version II). High ICC-values (0.80–0.99) and acceptable CV-values (1.9–8.7%) could be found for MVC as well as for the RTD and the impulse taken at time intervals of ≥100 ms, regardless of whether version I or II was used. In contrast, measurements of the RTDpeak as well as the RTD and the impulse taken during the very early contraction phase (i.e. RTD/impulse0–30ms and RTD/impulse0–50ms) showed clearly weaker reproducibility results (ICC: 0.53–0.84; CV: 7.3–16.4%) and gave rise to considerable doubts as to clinical usefulness, especially when derived using version I. However, if there is a need to measure explosive strength for earlier time intervals in practice, it is, in view of stronger reproducibility results, recommended to concentrate on measures derived from version II, which is based on the RTDpeak-trial. PMID:28149337

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players

PubMed Central

Heishman, Aaron D.; Curtis, Michael A.; Saliba, Ethan N.; Hornett, Robert J.; Malin, Steven K.

2017-01-01

Abstract Heishman, AD, Curtis, MA, Saliba, EN, Hornett, RJ, Malin, SK, and Weltman, AL. Comparing performance during morning vs. afternoon training sessions in intercollegiate basketball players. J Strength Cond Res 31(6): 1557–1562, 2017—Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is suppressed with morning training and is associated with a decrease in self-reported quantity of sleep. PMID:28538305

GROUT-CONCRETE INTERFACE BOND PERFORMANCE: EFFECT OF INTERFACE MOISTURE ON THE TENSILE BOND STRENGTH AND GROUT MICROSTRUCTURE.

PubMed

De la Varga, I; Muñoz, J F; Bentz, D P; Spragg, R P; Stutzman, P E; Graybeal, B A

2018-05-01

Bond between two cementitious materials is crucial in applications such as repairs, overlays, and connections of prefabricated bridge elements (PBEs), to name just a few. It is the latter that has special interest to the authors of this paper. After performing a dimensional stability study on grout-like materials commonly used as connections between PBEs, it was observed that the so-called 'non-shrink' cementitious grouts showed a considerable amount of early-age shrinkage. This might have negative effects on the integrity of the structure, due not only to the grout material's early degradation, but also to a possible loss of bond between the grout and the prefabricated concrete element. Many factors affect the bond strength between two cementitious materials (e.g., grout-concrete), the presence of moisture at the existing concrete substrate surface being one of them. In this regard, pre-moistening the concrete substrate surface prior to the application of the grout material is sometimes recommended for bond enhancement. This topic has been the focus of numerous research studies in the past; however, there is still controversy among practitioners on the real benefits that this practice might provide. This paper evaluates the tensile bond performance of two non-shrink cementitious grouts applied to the exposed aggregate surface of a concrete substrate, and how the supply of moisture at the grout-concrete interface affects the bond strength. "Pull-off" bond results show increased tensile bond strength when the concrete surface is pre-moistened. Reasons to explain the observed increased bond strength are given after a careful microstructural analysis of the grout-concrete interface. Interfaces where sufficient moisture is provided to the concrete substrate such that moisture movement from the grout is prevented show reduced porosity and increased hydration on the grout side of the interface, which is thought to directly contribute to the increased tensile bond strength.

NASA Lewis Nickel Alloy being Poured in the Technical Service Building

NASA Image and Video Library

1966-04-21

A nickel alloy developed at the National Aeronautics and Space Administration (NASA) Lewis Research Center being poured in a shop inside the Technical Services Building. Materials technology is an important element in the successful development of both advanced airbreathing and rocket propulsion systems. An array of dependable materials is needed to build different types of engines for operation in diverse environments. NASA Lewis began investigating the characteristics of different materials shortly after World War II. In 1949 the materials research group was expanded into its own division. The Lewis researchers studied and tested materials in environments that simulated the environment in which they would operate. Lewis created two programs in the early 1960s to create materials for new airbreathing engines. One concentrated on high-temperature alloys and the other on cooling turbine blades. William Klopp, Peter Raffo, Lester Rubenstein, and Walter Witzke developed Tungsten RHC, the highest strength metal at temperatures over 3500⁰ F. The men received an IR-100 Award for their efforts. Similarly a cobalt-tungsten alloy was developed by the Fatigue and Alloys Research Branch. The result was a combination of high temperature strength and magnetic properties that were applicable for generator rotor application. John Freche invented and patented a nickel alloy while searching for high temperature metals for aerospace use. NASA agreed to a three-year deal which granted Union Carbide exclusive use of the new alloy before it became public property.

Preventing postsurgical dissatisfaction syndrome after rhinoplasty with propranolol: a pilot study.

PubMed

Gruber, Ronald P; Roberts, Christa; Schooler, Wesley; Pitman, Roger K

2009-03-01

Rhinoplasty patients are commonly anxious about their result when the splint is removed. A small group of them, however, are overtly unhappy with their appearance despite objectively satisfactory early results, cannot be reassured about their favorable long-term prognosis, and remain dissatisfied despite objectively satisfactory end results. The authors have termed this symptom complex "postsurgical dissatisfaction syndrome." In these patients, it seems that persistence of the original negative image of their appearance at the time of splint removal fails to yield to an improved self-image as healing progresses. The authors theorized that the syndrome is analogous to the persistence of negative emotional memories seen in posttraumatic stress disorder. In trauma-exposed patients, the beta-adrenergic blocker propranolol, when given within a few hours of the traumatic event, may reduce the subsequent emotional strength of the traumatic memory. The authors hypothesized that giving propranolol to postrhinoplasty patients with the above early symptomatology would reduce the likelihood of postsurgical dissatisfaction syndrome. A retrospective review of 1000 consecutive rhinoplasty patients identified 11 with early symptomatology. Of these 11 (not taking propranolol), nine (82 percent) developed postsurgical dissatisfaction syndrome. In addition, a prospective study was performed of nine additional patients with the same early symptomatology who were immediately treated with propranolol. In contrast, only three developed postsurgical dissatisfaction syndrome (p < 0.04). Results of a randomized, double-blind, placebo-controlled study of 50 additional postrhinoplasty patients suggests that propranolol's effect is not due to anxiolysis. Propranolol given immediately after splint removal in anxious, unhappy cosmetic surgery patients may prevent postsurgical dissatisfaction syndrome. A double-blind study appears warranted.

Movement skill assessment of typically developing preschool children: a review of seven movement skill assessment tools.

PubMed

Cools, Wouter; Martelaer, Kristine De; Samaey, Christiane; Andries, Caroline

2009-06-01

The importance of movement is often overlooked because it is such a natural part of human life. It is, however, crucial for a child's physical, cognitive and social development. In addition, experiences support learning and development of fundamental movement skills. The foundations of those skills are laid in early childhood and essential to encourage a physically active lifestyle. Fundamental movement skill performance can be examined with several assessment tools. The choice of a test will depend on the context in which the assessment is planned. This article compares seven assessment tools which are often referred to in European or international context. It discusses the tools' usefulness for the assessment of movement skill development in general population samples. After a brief description of each assessment tool the article focuses on contents, reliability, validity and normative data. A conclusion outline of strengths and weaknesses of all reviewed assessment tools focusing on their use in educational research settings is provided and stresses the importance of regular data collection of fundamental movement skill development among preschool children. Key pointsThis review discusses seven movement skill assessment tool's test content, reliability, validity and normative samples.The seven assessment tools all showed to be of great value. Strengths and weaknesses indicate that test choice will depend on specific purpose of test use.Further data collection should also include larger data samples of able bodied preschool children.Admitting PE specialists in assessment of fundamental movement skill performance among preschool children is recommended.The assessment tool's normative data samples would benefit from frequent movement skill performance follow-up of today's children. MOT 4-6: Motoriktest fur vier- bis sechsjährige Kinder, M-ABC: Movement Assessment Battery for Children, PDMS: Peabody Development Scales, KTK: Körper-Koordinationtest für Kinder, TGDM: Test of Gross Motor Development, MMT: Maastrichtse Motoriektest, BOTMP: Bruininks-Oseretsky Test of Motor Proficiency. ICC: intraclass correlation coefficient, NR: not reported, GM: gross motor, LV: long version, SV: short version, LF: long form, SF: short form, STV: subtest version, SEMs: standard errors of measurement, TMQ: Total Motor Quotient, TMC: Total Motor Composite, CSSA: Comprehensive Scales of Student Abilities MSEL: Mullen Scales of Early learning: AGS Edition AUC: Areas under curve BC: Battery composite ROC: Receiver operating characteristic.

Movement Skill Assessment of Typically Developing Preschool Children: A Review of Seven Movement Skill Assessment Tools

PubMed Central

Cools, Wouter; Martelaer, Kristine De; Samaey, Christiane; Andries, Caroline

2009-01-01

The importance of movement is often overlooked because it is such a natural part of human life. It is, however, crucial for a child’s physical, cognitive and social development. In addition, experiences support learning and development of fundamental movement skills. The foundations of those skills are laid in early childhood and essential to encourage a physically active lifestyle. Fundamental movement skill performance can be examined with several assessment tools. The choice of a test will depend on the context in which the assessment is planned. This article compares seven assessment tools which are often referred to in European or international context. It discusses the tools’ usefulness for the assessment of movement skill development in general population samples. After a brief description of each assessment tool the article focuses on contents, reliability, validity and normative data. A conclusion outline of strengths and weaknesses of all reviewed assessment tools focusing on their use in educational research settings is provided and stresses the importance of regular data collection of fundamental movement skill development among preschool children. Key pointsThis review discusses seven movement skill assessment tool’s test content, reliability, validity and normative samples.The seven assessment tools all showed to be of great value. Strengths and weaknesses indicate that test choice will depend on specific purpose of test use.Further data collection should also include larger data samples of able bodied preschool children.Admitting PE specialists in assessment of fundamental movement skill performance among preschool children is recommended.The assessment tool’s normative data samples would benefit from frequent movement skill performance follow-up of today’s children. Abbreviations MOT 4-6: Motoriktest fur vier- bis sechsjährige Kinder, M-ABC: Movement Assessment Battery for Children, PDMS: Peabody Development Scales, KTK: Körper-Koordinationtest für Kinder, TGDM: Test of Gross Motor Development, MMT: Maastrichtse Motoriektest, BOTMP: Bruininks-Oseretsky Test of Motor Proficiency. ICC: intraclass correlation coefficient, NR: not reported, GM: gross motor, LV: long version, SV: short version, LF: long form, SF: short form, STV: subtest version, SEMs: standard errors of measurement, TMQ: Total Motor Quotient, TMC: Total Motor Composite, CSSA: Comprehensive Scales of Student Abilities MSEL: Mullen Scales of Early learning: AGS Edition AUC: Areas under curve BC: Battery composite ROC: Receiver operating characteristic PMID:24149522

Mechanical properties of new dental pulp-capping materials.

PubMed

Nielsen, Matthew J; Casey, Jeffery A; VanderWeele, Richard A; Vandewalle, Kraig S

2016-01-01

The mechanical properties of pulp-capping materials may affect their resistance to fracture during placement of a final restorative material or while supporting an overlying restoration over time. The purpose of this study was to compare the compressive strength, flexural strength, and flexural modulus of 2 new pulp-capping materials (TheraCal LC and Biodentine), mineral trioxide aggregate (MTA), and calcium hydroxide over time. Specimens were created in molds and tested to failure in a universal testing machine after 15 minutes, 3 hours, and 24 hours. The MTA specimens did not set at 15 minutes. At all time periods, TheraCal LC had the greatest compressive and flexural strengths. After 3 and 24 hours, Biodentine had the greatest flexural modulus. TheraCal LC had greater early strength to potentially resist fracture during immediate placement of a final restorative material. Biodentine had greater stiffness after 3 hours to potentially provide better support of an overlying restoration under function over time.

First-Year College Students' Strengths Awareness and Perceived Leadership Development

ERIC Educational Resources Information Center

Soria, Krista M.; Roberts, Julia E.; Reinhard, Alex P.

2015-01-01

The purpose of this study was to examine whether first-year college students' strengths awareness is associated with their perceived leadership development. The institution in this study offered all first-year students the Clifton StrengthsFinder assessment and strengths-related programming. The results of hierarchical regression analysis of two…

Hyperexcitability of Rat Thalamocortical Networks after Exposure to General Anesthesia during Brain Development

PubMed Central

DiGruccio, Michael R.; Joksimovic, Srdjan; Joksovic, Pavle M.; Lunardi, Nadia; Salajegheh, Reza; Jevtovic-Todorovic, Vesna; Beenhakker, Mark P.; Goodkin, Howard P.

2015-01-01

Prevailing literature supports the idea that common general anesthetics (GAs) cause long-term cognitive changes and neurodegeneration in the developing mammalian brain, especially in the thalamus. However, the possible role of GAs in modifying ion channels that control neuronal excitability has not been taken into consideration. Here we show that rats exposed to GAs at postnatal day 7 display a lasting reduction in inhibitory synaptic transmission, an increase in excitatory synaptic transmission, and concomitant increase in the amplitude of T-type calcium currents (T-currents) in neurons of the nucleus reticularis thalami (nRT). Collectively, this plasticity of ionic currents leads to increased action potential firing in vitro and increased strength of pharmacologically induced spike and wave discharges in vivo. Selective blockade of T-currents reversed neuronal hyperexcitability in vitro and in vivo. We conclude that drugs that regulate thalamic excitability may improve the safety of GAs used during early brain development. PMID:25632125

THE ROLE OF AN IMMIGRANT MOTHER IN HER ADOLESCENT'S IDENTITY FORMATION: "WHO AM I?".

PubMed

Mann, Mali

2016-06-01

Immigration is a complex bio-psycho-social process and the immigrant mother has a truly complex task in lending her ego strength to her adolescent offspring. The normal adolescence's decathexis of the love object and the consequent search for a new object may not happen smoothly for those adolescents whose mothers are immigrants. The immigration experience may cause the immigrant mother, who lost her motherland, deeper disturbance in self-identity as well as disequilibrium in her psychic structure, which in turn impacts adversely her adolescent's development. The adolescent's inadequate early experience with an immigrant mother may result in a deeper disturbance in his separation-individuation process as well as his identification process. An immigrant mother who has not mourned adequately, with a different sociocultural background has to go through a far more complex development of motherhood. The case of an adolescent boy, Jason, demonstrates the impact of immigrant motherhood on his ego development.

Establishment of a new pull-out strength testing method to quantify early osseointegration-An experimental pilot study.

PubMed

Nonhoff, J; Moest, T; Schmitt, Christian Martin; Weisel, T; Bauer, S; Schlegel, K A

2015-12-01

The animal study aims to evaluate a new experimental model for measuring sole the influence of the surface characteristics independent from implant macro-design on the level of osseointegration by registering the pull-out strength needed for removal of experimental devices with different surfaces from artificial defects. Seventy-two test bodies (36 with the FRIADENT(®) plus surface, 36 with the P15/HAp biofunctionalized surface) were inserted in six adult domestic pigs with artificial calvarial defects. The experimental devices were designed to fit in the defects leaving a gap between the test body and the local bone. After 21 days of healing, the animals were sacrificed and the test bodies were pulled out with a standardised reproducible pull-out device measuring the pull-out strength. The pull-out strength for both groups was compared. Twenty-one days after insertion a mean force of 412 ± 142 N for the P15/HAp group and 183 ± 105 N for the FRIADENT(®) plus group was measured for the removal of the specimens from the calvarial bone. The difference between the groups was statistically significant (p < 0.0001). The experimental set-up seems to be a suitable method when measuring the impact of implant surfaces on the early stage of osseointegration. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Protein requirements and muscle mass/strength changes during intensive training in novice bodybuilders.

PubMed

Lemon, P W; Tarnopolsky, M A; MacDougall, J D; Atkinson, S A

1992-08-01

This randomized double-blind cross-over study assessed protein (PRO) requirements during the early stages of intensive bodybuilding training and determined whether supplemental PRO intake (PROIN) enhanced muscle mass/strength gains. Twelve men [22.4 +/- 2.4 (SD) yr] received an isoenergetic PRO (total PROIN 2.62 g.kg-1.day-1) or carbohydrate (CHO; total PROIN 1.35 g.kg-1.day-1) supplement for 1 mo each during intensive (1.5 h/day, 6 days/wk) weight training. On the basis of 3-day nitrogen balance (NBAL) measurements after 3.5 wk on each treatment (8.9 +/- 4.2 and -3.4 +/- 1.9 g N/day, respectively), the PROIN necessary for zero NBAL (requirement) was 1.4-1.5 g.kg-1.day-1. The recommended intake (requirement + 2 SD) was 1.6-1.7 g.kg-1.day-1. However, strength (voluntary and electrically evoked) and muscle mass [density, creatinine excretion, muscle area (computer axial tomography scan), and biceps N content] gains were not different between diet treatments. These data indicate that, during the early stages of intensive bodybuilding training, PRO needs are approximately 100% greater than current recommendations but that PROIN increases from 1.35 to 2.62 g.kg-1.day-1 do not enhance muscle mass/strength gains, at least during the 1st mo of training. Whether differential gains would occur with longer training remains to be determined.

Connectivity Strength-Weighted Sparse Group Representation-Based Brain Network Construction for MCI Classification

PubMed Central

Yu, Renping; Zhang, Han; An, Le; Chen, Xiaobo; Wei, Zhihui; Shen, Dinggang

2017-01-01

Brain functional network analysis has shown great potential in understanding brain functions and also in identifying biomarkers for brain diseases, such as Alzheimer's disease (AD) and its early stage, mild cognitive impairment (MCI). In these applications, accurate construction of biologically meaningful brain network is critical. Sparse learning has been widely used for brain network construction; however, its l1-norm penalty simply penalizes each edge of a brain network equally, without considering the original connectivity strength which is one of the most important inherent linkwise characters. Besides, based on the similarity of the linkwise connectivity, brain network shows prominent group structure (i.e., a set of edges sharing similar attributes). In this article, we propose a novel brain functional network modeling framework with a “connectivity strength-weighted sparse group constraint.” In particular, the network modeling can be optimized by considering both raw connectivity strength and its group structure, without losing the merit of sparsity. Our proposed method is applied to MCI classification, a challenging task for early AD diagnosis. Experimental results based on the resting-state functional MRI, from 50 MCI patients and 49 healthy controls, show that our proposed method is more effective (i.e., achieving a significantly higher classification accuracy, 84.8%) than other competing methods (e.g., sparse representation, accuracy = 65.6%). Post hoc inspection of the informative features further shows more biologically meaningful brain functional connectivities obtained by our proposed method. PMID:28150897

Evaluation of wound healing, anti-microbial and antioxidant potential of Pongamia pinnata in wistar rats.

PubMed

Dwivedi, Deepak; Dwivedi, Mona; Malviya, Sourabh; Singh, Vinod

2017-01-01

To investigate wound healing, antimicrobial and antioxidant activity of leaf extract of Pongamia Pinnata . Methanolic extracts of P. pinnata leaf were studied for wound healing efficiency, and was assessed by the rate of wound contraction, tensile strength, breaking strength, hydroxyproline and hexosamine content, along with its effect on pro-inflammatory and anti-inflammatory cytokines was assessed using excision and incision model of wound repair in Wistar rats. Antimicrobial activity against ten microorganisms was also assessed. In vivo antioxidant activity was performed to understand the mechanism of wound healing potency. The results indicated that P. pinnata extract has potent wound healing capacity as evident from the wound contraction and increased tensile strength. Hydroxyproline and hexosamine expression were also well correlated with the healing pattern observed. extract exhibited significant antimicrobial activity, Staphylococcus aureus, Staphylococcus pyogenes, Staphylococcus epidermidis, Escherichia coli, Micrococcus luteus, Enterobacter aerogenes, Salmonella typhi, Pseudomonas aeruginosa, Candida albicans, Aspergillus niger also indicate that P. pinnata posses potent antioxidant activity by inhibition lipid peroxidation, reduce glutathione, superoxide dismutase level and increases catalase activity. During early wound healing phase TNF-α and IL-6 level were found to be up-regulated by P. pinnata treatment. Increased wound contraction and tensile strength, augmented hydroxyproline and hexosamine content, antioxidative activity and moderate antimicrobial activity support the early wound healing exhibited by P. pinnata . Induction in cytokine production may be one of the mechanisms in accelerating the wound healing. Results suggest that P. pinnata may be useful in tropical management of wound healing.

Memory of myself: autobiographical memory and identity in Alzheimer's disease.

PubMed

Addis, Donna Rose; Tippett, Lynette J

2004-01-01

A number of theories posit a relationship between autobiographical memory and identity. To test this we assessed the status of autobiographical memory and identity in 20 individuals with Alzheimer's disease (AD) and 20 age-matched controls, and investigated whether degree of autobiographical memory impairment was associated with changes in identity. Two tests of autobiographical memory (Autobiographical Memory Interview, autobiographical fluency) and two measures of identity (Twenty Statements Test, identity items of the Tennessee Self Concept Scale) were administered. AD participants exhibited significant impairments on both memory tests, and changes in the strength, quality, and direction of identity relative to controls. Impairments of some components of autobiographical memory, particularly autobiographical memory for childhood and early adulthood, were related to changes in the strength and quality of identity. These findings support the critical role of early adulthood autobiographical memories (16-25 years) in identity, and suggest autobiographical memory loss affects identity.

Communication and Language in Learners Who Are Deaf and Hard of Hearing With Disabilities: Theories, Research, and Practice.

PubMed

Bruce, Susan M; Borders, Christy

2015-01-01

Findings are presented from communication intervention research in three areas related to deafness with disability (DWD): D/deaf and hard of hearing (DHH) with (a) intellectual disability, (b) autism spectrum disorders, (c) deafblindness. Early identification, prevalence, theoretical perspectives, and evidence-based practices are discussed. Developmental theory, behavioral theory, and social-interactionism theory undergird many assessment and intervention practices in communication. The tri-focus framework and the four aspects of communication are useful frameworks. While communication research is a relative strength in the deafblindness field, a dire need exists for research in the other two DWD areas. Across all DWD areas there is a need for interventions addressing receptive language. Effective communication and language intervention can only occur when children who are DWD are identified early, placed in individually suitable classrooms with appropriately prepared professionals, and provided with services that build on their strengths and meet their needs.

Cardiovascular drug discovery in the academic setting: building infrastructure, harnessing strengths, and seeking synergies.

PubMed

Gardell, Stephen J; Roth, Gregory P; Kelly, Daniel P

2010-10-01

The flow of innovative, effective, and safe new drugs from pharmaceutical laboratories for the treatment and prevention of cardiovascular disease has slowed to a trickle. While the need for breakthrough cardiovascular disease drugs is still paramount, the incentive to develop these agents has been blunted by burgeoning clinical development costs coupled with a heightened risk of failure due to the unprecedented nature of the emerging drug targets and increasingly challenging regulatory environment. A fuller understanding of the drug targets and employing novel biomarker strategies in clinical trials should serve to mitigate the risk. In any event, these current challenges have evoked changing trends in the pharmaceutical industry, which have created an opportunity for non-profit biomedical research institutions to play a pivotal partnering role in early stage drug discovery. The obvious strengths of academic research institutions is the breadth of their scientific programs and the ability and motivation to "go deep" to identify and characterize new target pathways that unlock the specific mysteries of cardiovascular diseases--leading to a bounty of novel therapeutic targets and prescient biomarkers. However, success in the drug discovery arena within the academic environment is contingent upon assembling the requisite infrastructure, annexing the talent to interrogate and validate the drug targets, and building translational bridges with pharmaceutical organizations and patient-oriented researchers.

Resorbable bone fixation alloys, forming, and post-fabrication treatments.

PubMed

Ibrahim, Hamdy; Esfahani, Sajedeh Nasr; Poorganji, Behrang; Dean, David; Elahinia, Mohammad

2017-01-01

Metallic alloys have been introduced as biodegradable metals for various biomedical applications over the last decade owing to their gradual corrosion in the body, biocompatibility and superior strength compared to biodegradable polymers. Mg alloys possess advantageous properties that make them the most extensively studied biodegradable metallic material for orthopedic applications such as their low density, modulus of elasticity, close to that of the bone, and resorbability. Early resorption (i.e., <3months) and relatively inadequate strength are the main challenges that hinder the use of Mg alloys for bone fixation applications. The development of resorbable Mg-based bone fixation hardware with superior mechanical and corrosion performance requires a thorough understanding of the physical and mechanical properties of Mg alloys. This paper discusses the characteristics of successful Mg-based skeletal fixation hardware and the possible ways to improve its properties using different methods such as mechanical and heat treatment processes. We also review the most recent work pertaining to Mg alloys and surface coatings. To this end, this paper covers (i) the properties and development of Mg alloys and coatings with an emphasis on the Mg-Zn-Ca-based alloys; (ii) Mg alloys fabrication techniques; and (iii) strategies towards achieving Mg-based, resorbable, skeletal fixation devices. Copyright © 2016 Elsevier B.V. All rights reserved.

The Association between Preschool Children's Social Functioning and Their Emergent Academic Skills.

PubMed

Arnold, David H; Kupersmidt, Janis B; Voegler-Lee, Mary Ellen; Marshall, Nastassja

2012-01-01

This study examined the relationship between social functioning and emergent academic development in a sample of 467 preschool children (M = 55.9 months old, SD = 3.8). Teachers reported on children's aggression, attention problems, and prosocial skills. Preliteracy, language, and early mathematics skills were assessed with standardized tests. Better social functioning was associated with stronger academic development. Attention problems were related to poorer academic development controlling for aggression and social skills, pointing to the importance of attention in these relations. Children's social skills were related to academic development controlling for attention and aggression problems, consistent with models suggesting that children's social strengths and difficulties are independently related to their academic development. Support was not found for the hypothesis that these relationships would be stronger in boys than in girls. Some relationships were stronger in African American than Caucasian children. Children's self-reported feelings about school moderated several relationships, consistent with the idea that positive feelings about school may be a protective factor against co-occurring academic and social problems.

Retrograde Signaling from Progranulin to Sort1 Counteracts Synapse Elimination in the Developing Cerebellum.

PubMed

Uesaka, Naofumi; Abe, Manabu; Konno, Kohtarou; Yamazaki, Maya; Sakoori, Kazuto; Watanabe, Takaki; Kao, Tzu-Huei; Mikuni, Takayasu; Watanabe, Masahiko; Sakimura, Kenji; Kano, Masanobu

2018-02-21

Elimination of redundant synapses formed early in development and strengthening of necessary connections are crucial for shaping functional neural circuits. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs) with similar strengths. A single CF is strengthened whereas the other CFs are eliminated in each PC during postnatal development. The underlying mechanisms, particularly for the strengthening of single CFs, are poorly understood. Here we report that progranulin, a multi-functional growth factor implicated in the pathogenesis of frontotemporal dementia, strengthens developing CF synaptic inputs and counteracts their elimination from postnatal day 11 to 16. Progranulin derived from PCs acts retrogradely onto its putative receptor Sort1 on CFs. This effect is independent of semaphorin 3A, another retrograde signaling molecule that counteracts CF synapse elimination. We propose that progranulin-Sort1 signaling strengthens and maintains developing CF inputs, and may contribute to selection of single "winner" CFs that survive synapse elimination. Copyright © 2018 Elsevier Inc. All rights reserved.

Shoulder functional ratio in elite junior tennis players.

PubMed

Saccol, Michele Forgiarini; Gracitelli, Guilherme Conforto; da Silva, Rogério Teixeira; Laurino, Cristiano Frota de Souza; Fleury, Anna Maria; Andrade, Marília dos Santos; da Silva, Antonio Carlos

2010-02-01

To evaluate shoulder rotation strength and compare the functional ratio between shoulders of elite junior tennis players. This cross-sectional study evaluated muscular rotation performance of 40 junior tennis players (26 male and 14 female) with an isokinetic dynamometer. Strength variables of external (ER) and internal rotators (IR) in concentric and eccentric modes were considered. For the peak torque functional ratio, the eccentric strength of the ER and the concentric strength of the IR were calculated. All variables related to IR were significantly higher on the dominant compared to the non-dominant side in males and females (p<0.05), but only boys exhibited this dominance effect in ER (p<0.05 and p<0.001). Regarding functional ratios, they were significantly lower for the dominant shoulder (p<0.001) and below 1.00 for both groups, indicating that the eccentric strength of the ER was not greater than the concentric strength of the IR. Elite junior tennis players without shoulder injury have shoulder rotation muscle strength imbalances that alter the normal functional ratio between rotator cuff muscles. Although these differences do not seem to affect the athletic performance, detection and prevention with exercise programs at an early age are recommended. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

Early poststroke rehabilitation using a robotic tilt-table stepper and functional electrical stimulation.

PubMed

Kuznetsov, Alexey N; Rybalko, Natalia V; Daminov, Vadim D; Luft, Andreas R

2013-01-01

Background. Stroke frequently leaves survivors with hemiparesis. To prevent persistent deficits, rehabilitation may be more effective if started early. Early training is often limited because of orthostatic reactions. Tilt-table stepping robots and functional electrical stimulation (FES) may prevent these reactions. Objective. This controlled convenience sample study compares safety and feasibility of robotic tilt-table training plus FES (ROBO-FES) and robotic tilt-table training (ROBO) against tilt-table training alone (control). A preliminary assessment of efficacy is performed. Methods. Hemiparetic ischemic stroke survivors (age 58.3 ± 1.2 years, 4.6 ± 1.2 days after stroke) were assigned to 30 days of ROBO-FES (n = 38), ROBO (n = 35), or control (n = 31) in addition to conventional physical therapy. Impedance cardiography and transcranial doppler sonography were performed before, during, and after training. Hemiparesis was assessed using the British Medical Research Council (MRC) strength scale. Results. No serious adverse events occurred; 8 patients in the tilt-table group prematurely quit the study because of orthostatic reactions. Blood pressure and CBFV dipped <10% during robot training. In 52% of controls mean arterial pressure decreased by ≥20%. ROBO-FES increased leg strength by 1.97 ± 0.88 points, ROBO by 1.50 ± 0.85 more than control (1.03 ± 0.61, P < 0.05). CBFV increased in both robotic groups more than in controls (P < 0.05). Conclusions. Robotic tilt-table exercise with or without FES is safe and may be more effective in improving leg strength and cerebral blood flow than tilt table alone.

Early Poststroke Rehabilitation Using a Robotic Tilt-Table Stepper and Functional Electrical Stimulation

PubMed Central

Kuznetsov, Alexey N.; Rybalko, Natalia V.; Daminov, Vadim D.; Luft, Andreas R.

2013-01-01

Background. Stroke frequently leaves survivors with hemiparesis. To prevent persistent deficits, rehabilitation may be more effective if started early. Early training is often limited because of orthostatic reactions. Tilt-table stepping robots and functional electrical stimulation (FES) may prevent these reactions. Objective. This controlled convenience sample study compares safety and feasibility of robotic tilt-table training plus FES (ROBO-FES) and robotic tilt-table training (ROBO) against tilt-table training alone (control). A preliminary assessment of efficacy is performed. Methods. Hemiparetic ischemic stroke survivors (age 58.3 ± 1.2 years, 4.6 ± 1.2 days after stroke) were assigned to 30 days of ROBO-FES (n = 38), ROBO (n = 35), or control (n = 31) in addition to conventional physical therapy. Impedance cardiography and transcranial doppler sonography were performed before, during, and after training. Hemiparesis was assessed using the British Medical Research Council (MRC) strength scale. Results. No serious adverse events occurred; 8 patients in the tilt-table group prematurely quit the study because of orthostatic reactions. Blood pressure and CBFV dipped <10% during robot training. In 52% of controls mean arterial pressure decreased by ≥20%. ROBO-FES increased leg strength by 1.97 ± 0.88 points, ROBO by 1.50 ± 0.85 more than control (1.03 ± 0.61, P < 0.05). CBFV increased in both robotic groups more than in controls (P < 0.05). Conclusions. Robotic tilt-table exercise with or without FES is safe and may be more effective in improving leg strength and cerebral blood flow than tilt table alone. PMID:23691432

Oestrogen status in relation to the early training responses in human thumb adductor muscles.

PubMed

Onambele, G N L; Bruce, S A; Woledge, R C

2006-09-01

The aims of this study were to identify the mechanisms for the early response to training in women of different oestrogen status and to determine whether any oestrogen and exercise effects on these would be additive. We monitored training (ten 5-s contractions per day for 12 weeks)-induced changes in the size, strength, voluntary activation capacity and index of crossbridge force state (i.e. rapid stretch to isometric torque ratio), in the thumb adductor muscles of postmenopausal [eight who had never used, and 14 who were using, hormone replacement therapy (HRT)] and seven premenopausal eumenorrhoeic women. The contralateral untrained muscle was used as a control. There was a significant effect of oestrogen status on the magnitude of training-induced strength increment, with the non-HRT postmenopausal group exhibiting the greatest benefits (28 +/- 6%, P = 0.024) from training. There were no significant or commensurate changes in either cross-sectional area or voluntary activation capacity. The index of crossbridge force state improved most in the no-HRT group (19 +/- 7%, P < 0.05). Presence, rather than absence of oestrogen, is associated with relatively higher muscle function which limits the potential for any further training-induced increments in muscle performance, as would be expected if the muscle strengthening actions of training and oestrogen share a common, partially saturable physiological pathway. The mechanism that is involved in the early training-induced strength increment in the three differing oestrogen groups cannot be due to increased size or recruitment. It would appear instead that increased motor unit firing frequency is involved.

Abscission zone development in Setaria viridis and its domesticated relative, Setaria italica.

PubMed

Hodge, John G; Kellogg, Elizabeth A

2016-06-01

Development of an abscission zone (AZ) is needed for dispersal of seeds, and AZ loss was a critical early step in plant domestication. The AZ forms in different tissues in different species of plants, but whether the AZ is developmentally similar wherever it occurs is unknown. AZ development in Setaria viridis was studied as a representative of the previously uncharacterized subfamily Panicoideae. One accession of the wild species S. viridis and two of its domesticate, S. italica, were studied. Strength of the AZ was measured with a force gauge. Anatomy of the AZ was studied throughout development using bright field and confocal microscopy. The force required to remove a spikelet of S. viridis from the parent plant dropped steadily during development, whereas that required to remove spikelets of S. italica increased initially before stabilizing at a high level. Despite the clear difference in tensile strength of the AZ, anatomical differences between S. viridis and S. italica were subtle, and the position of the AZ was not easy to determine in cross sections of pedicel apices. Staining with DAPI showed that nuclei were present up to and presumably through abscission in S. viridis, and acridine orange staining showed much less lignification than in other cereals. The AZ in Setaria is developmentally and anatomically different from that characterized in rice, barley, and many eudicots. In particular, no set of small, densely cytoplasmic cells is obvious. This difference in anatomy could point to differential genetic control of the structure. © 2016 Botanical Society of America.

Effect of planetary rotation on the differentiation of a terrestrial magma ocean in spherical geometry

NASA Astrophysics Data System (ADS)

Hansen, Ulrich; Maas, Christian

2017-04-01

About 4.5 billion years ago the early Earth experienced several giant impacts that lead to one or more deep terrestrial magma oceans of global extent. The crystallization of these vigorously convecting magma oceans is of key importance for the chemical structure of the Earth, the subsequent mantle evolution as well as for the initial conditions for the onset of plate tectonics. Due to the fast planetary rotation of the early Earth and the small magma viscosity, rotation probably had a profound effect on early differentiation processes and could for example influence the presence and distribution of chemical heterogeneities in the Earth's mantle [e.g. Matyska et al., 1994, Garnero and McNamara, 2008]. Previous work in Cartesian geometry revealed a strong influence of rotation as well as of latitude on the crystal settling in a terrestrial magma ocean [Maas and Hansen, 2015]. Based on the preceding study we developed a spherical shell model that allows to study crystal settling in-between pole and equator as well as the migration of crystals between these regions. Further we included centrifugal forces on the crystals, which significantly affect the lateral and radial distribution of the crystals. Depending on the strength of rotation the particles accumulate at mid-latitude or at the equator. At high rotation rates the dynamics of fluid and particles are dominated by jet-like motions in longitudinal direction that have different directions on northern and southern hemisphere. All in all the first numerical experiments in spherical geometry agree with Maas and Hansen [2015] that the crystal distribution crucially depends on latitude, rotational strength and crystal density. References E. J. Garnero and A. K. McNamara. Structure and dynamics of earth's lower mantle. Science, 320(5876):626-628, 2008. C. Maas and U. Hansen. Eff ects of earth's rotation on the early di erentiation of a terrestrial magma ocean. Journal of Geophysical Research: Solid Earth, 120(11):7508-7525, 2015. C. Matyska, J. Moser, and D. A. Yuen. The potential influence of radiative heat transfer on the formation of megaplumes in the lower mantle. Earth and Planetary Science Letters, 125(1):255-266, 1994.

Thin film self-assembly of PVMS-b-PMMA block copolymer

NASA Astrophysics Data System (ADS)

Lwoya, Baraka; Uddin, Md; Chatterjee, Sourav; Albert, Julie

Self-assembly of block copolymers has been explored for numerous years with a primary emphasis on nanolithographic templates and membrane applications. Block copolymers (BCPs) hold great promise as next-generation patterning materials for sub-10 nm nano-electronic applications. However, the inherent properties to develop smaller more ordered thin films ( 10-100 nm) is greatly hindered by the inability of the low segregation strength of conventional polymers such as poly(styrene-block-methylmethacrylate). We aim at addressing this issue by firstly synthesizing strongly segregating BCPs of poly(vinylmethylsiloxane-block-methyl methacrylate) (PVMS- b - PMMA) with different block volume fractions. Second, we induce self-assembly by either thermal or solvent annealing and characterize the morphology by atomic force microscopy (AFM). In addition, the use of a block with a pendant vinyl group provides the ability to functionalize the PVMS segment by thiol-ene reaction, either to further control of the segregation strength or to impart desirable surface chemical properties (e.g., adhesion/lift-off in templating or functionality in membranes). Gulf Research Program Early-Career Research Fellowship.

The purinergic receptor P2X5 regulates inflammasome activity and hyper-multinucleation of murine osteoclasts

DOE PAGES

Kim, Hyunsoo; Walsh, Matthew C.; Takegahara, Noriko; ...

2017-03-15

Excessive bone resorption by osteoclasts (OCs) can result in serious clinical outcomes, including bone loss that may weaken skeletal or periodontal strength. Proper bone homeostasis and skeletal strength are maintained by balancing OC function with the bone-forming function of osteoblasts. Unfortunately, current treatments that broadly inhibit OC differentiation or function may also interfere with coupled bone formation. We therefore identified a factor, the purinergic receptor P2X5 that is highly expressed during the OC maturation phase, and which we show here plays no apparent role in early bone development and homeostasis, but which is required for osteoclast-mediated inflammatory bone loss andmore » hyper-multinucleation of OCs. We further demonstrate that P2X5 is required for ATP-mediated inflammasome activation and IL-1β production by OCs, and that P2X5-deficient OC maturation is rescued in vitro by addition of exogenous IL-1β. These findings identify a mechanism by which OCs react to inflammatory stimuli, and may identify purinergic signaling as a therapeutic target for bone loss related inflammatory conditions.« less

The purinergic receptor P2X5 regulates inflammasome activity and hyper-multinucleation of murine osteoclasts

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

Kim, Hyunsoo; Walsh, Matthew C.; Takegahara, Noriko

Excessive bone resorption by osteoclasts (OCs) can result in serious clinical outcomes, including bone loss that may weaken skeletal or periodontal strength. Proper bone homeostasis and skeletal strength are maintained by balancing OC function with the bone-forming function of osteoblasts. Unfortunately, current treatments that broadly inhibit OC differentiation or function may also interfere with coupled bone formation. We therefore identified a factor, the purinergic receptor P2X5 that is highly expressed during the OC maturation phase, and which we show here plays no apparent role in early bone development and homeostasis, but which is required for osteoclast-mediated inflammatory bone loss andmore » hyper-multinucleation of OCs. We further demonstrate that P2X5 is required for ATP-mediated inflammasome activation and IL-1β production by OCs, and that P2X5-deficient OC maturation is rescued in vitro by addition of exogenous IL-1β. These findings identify a mechanism by which OCs react to inflammatory stimuli, and may identify purinergic signaling as a therapeutic target for bone loss related inflammatory conditions.« less

Vorticity generation and jetting caused by a laser-induced optical breakdown

NASA Astrophysics Data System (ADS)

Wang, Jonathan; Buchta, David; Freund, Jonathan

2017-11-01

A focused laser can cause optical breakdown of a gas that absorbs energy and can seed ignition. The local hydrodynamics are complex. The breakdown is observed to produce vorticity that subsequently collects into a jetting flow towards the laser source. The strength and the very direction of the jet is observed to be sensitive to the plasma kernel geometry. We use detailed numerical simulations to examine the short-time (< 1 μ s) dynamics leading to this vorticity and jetting. The simulation employs a two-temperature model, free-electron generation by multi-photon ionization, absorption of laser energy by inverse Bremsstrahlung, and 11 charged and neutral species for air. We quantify the early-time contributions of different thermodynamic and gas-dynamic effects to the baroclinic torque. It is found that the breakdown produces compression waves within the plasma kernel, and that the mismatch in their strengths precipitates the involution of the plasma remnants and yields the net vorticity that ultimately develops into the jet. We also quantify the temperature distribution and local strain rates and demonstrate their importance in seeding ignition in non-homogeneous hydrogen/air mixtures.

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

Life in the laboratory: public responses to experimental biology.

PubMed

Turney, J

1995-04-01

Present-day public attitudes to biological manipulation are ambivalent, many surveys show. This paper explores evidence of earlier attitudes to experimental biology, before survey data exists, by examining published responses in the press to the idea that biologists would 'create life'. This remarkable claim achieved wide currency in the early years of this century, particularly linked to the work of two prototypical 'visible scientists': Jacques Loeb and Alexis Carrel. Analysis of press responses to accounts of their work reveals deep disquiet about its possible implications, at a time when science and technology in general were regarded very positively. The evidence is augmented by studying commentary on a Presidential Address by Edward Schafer to the British Association meeting of 1912. It is concluded that feelings of ambivalence toward the manipulative power of biology are apparent at a very early stage in the development of modern biology, and that this makes it implausible that more recent manifestations of such ambivalence can be ascribed to some generalized 'anti-science' sentiment which has gathered strength in recent years.

Developing hands-on ergonomics lessons for youth

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

Bennett, C; Alexandre, M; Jacobs, K

2006-02-22

By the time students are ready to enter the workforce they have been exposed to up to 20 years of ergonomics risk factors. As technology evolves, it provides more opportunities for intensive repetitive motion and with computers, cell phones, personal digital assistants (PDAs), and electronic games. The average student engages in fewer active physical activities, sit stationary in mismatched furniture in schools for hours and carry heavy backpacks. While long-term effects remain to be identified, increasingly ergonomists and others concerned with musculoskeletal health and wellness, see a need for early ergonomics education. This interactive session provides a hands-on approach tomore » introducing ergonomics to students. Although different approaches may effectively introduce ergonomics at even early stages of development, this program was designed for youth at the middle to high school age. Attendees will participate in four activities designed to introduce ergonomics at an experiential level. The modules focus on grip strength, effective breathing, optimizing your chair, and backpack safety. The workshop will include presentation and worksheets designed for use by teachers with minimal ergonomics training. Feedback from the participants will be sought for further refining the usability and safety of the training package.« less

Brain network informed subject community detection in early-onset schizophrenia.

PubMed

Yang, Zhi; Xu, Yong; Xu, Ting; Hoy, Colin W; Handwerker, Daniel A; Chen, Gang; Northoff, Georg; Zuo, Xi-Nian; Bandettini, Peter A

2014-07-03

Early-onset schizophrenia (EOS) offers a unique opportunity to study pathophysiological mechanisms and development of schizophrenia. Using 26 drug-naïve, first-episode EOS patients and 25 age- and gender-matched control subjects, we examined intrinsic connectivity network (ICN) deficits underlying EOS. Due to the emerging inconsistency between behavior-based psychiatric disease classification system and the underlying brain dysfunctions, we applied a fully data-driven approach to investigate whether the subjects can be grouped into highly homogeneous communities according to the characteristics of their ICNs. The resultant subject communities and the representative characteristics of ICNs were then associated with the clinical diagnosis and multivariate symptom patterns. A default mode ICN was statistically absent in EOS patients. Another frontotemporal ICN further distinguished EOS patients with predominantly negative symptoms. Connectivity patterns of this second network for the EOS patients with predominantly positive symptom were highly similar to typically developing controls. Our post-hoc functional connectivity modeling confirmed that connectivity strength in this frontotemporal circuit was significantly modulated by relative severity of positive and negative syndromes in EOS. This study presents a novel subtype discovery approach based on brain networks and proposes complex links between brain networks and symptom patterns in EOS.

NASA Applied Sciences' DEVELOP National Program: a unique model cultivating capacity in the geosciences

NASA Astrophysics Data System (ADS)

Ross, K. W.; Favors, J. E.; Childs-Gleason, L. M.; Ruiz, M. L.; Rogers, L.; Allsbrook, K. N.

2013-12-01

The NASA DEVELOP National Program takes a unique approach to cultivating the next generation of geoscientists through interdisciplinary research projects that address environmental and public policy issues through the application of NASA Earth observations. Competitively selected teams of students, recent graduates, and early career professionals take ownership of project proposals outlining basic application concepts and have ten weeks to research core scientific challenges, engage partners and end-users, demonstrate prototypical solutions, and finalize and document their results and outcomes. In this high pressure, results-driven environment emerging geoscience professionals build strong networks, hone effective communication skills, and learn how to call on the varied strengths of a multidisciplinary team to achieve difficult objectives. The DEVELOP approach to workforce development has a variety of advantages over classic apprenticeship-style internship systems. Foremost is the experiential learning of grappling with real-world applied science challenges as a primary actor instead of as an observer or minor player. DEVELOP participants gain experience that fosters personal strengths and service to others, promoting a balance of leadership and teamwork in order to successfully address community needs. The program also advances understanding of Earth science data and technology amongst participants and partner organizations to cultivate skills in managing schedules, risks and resources to best optimize outcomes. Individuals who come through the program gain experience and networking opportunities working within NASA and partner organizations that other internship and academic activities cannot replicate providing not only skill development but an introduction to future STEM-related career paths. With the competitive nature and growing societal role of science and technology in today's global community, DEVELOP fosters collaboration and advances environmental understanding by promoting and improving the ability of the future geoscience workforce to recognize, understand, and address environmental issues facing the Earth.

Predictive coding accelerates word recognition and learning in the early stages of language development.

PubMed

Ylinen, Sari; Bosseler, Alexis; Junttila, Katja; Huotilainen, Minna

2017-11-01

The ability to predict future events in the environment and learn from them is a fundamental component of adaptive behavior across species. Here we propose that inferring predictions facilitates speech processing and word learning in the early stages of language development. Twelve- and 24-month olds' electrophysiological brain responses to heard syllables are faster and more robust when the preceding word context predicts the ending of a familiar word. For unfamiliar, novel word forms, however, word-expectancy violation generates a prediction error response, the strength of which significantly correlates with children's vocabulary scores at 12 months. These results suggest that predictive coding may accelerate word recognition and support early learning of novel words, including not only the learning of heard word forms but also their mapping to meanings. Prediction error may mediate learning via attention, since infants' attention allocation to the entire learning situation in natural environments could account for the link between prediction error and the understanding of word meanings. On the whole, the present results on predictive coding support the view that principles of brain function reported across domains in humans and non-human animals apply to language and its development in the infant brain. A video abstract of this article can be viewed at: http://hy.fi/unitube/video/e1cbb495-41d8-462e-8660-0864a1abd02c. [Correction added on 27 January 2017, after first online publication: The video abstract link was added.]. © 2016 John Wiley & Sons Ltd.

Linking Executive Function and Peer Problems from Early Childhood Through Middle Adolescence.

PubMed

Holmes, Christopher J; Kim-Spoon, Jungmeen; Deater-Deckard, Kirby

2016-01-01

Peer interactions and executive function play central roles in the development of healthy children, as peer problems have been indicative of lower cognitive competencies such as self-regulatory behavior and poor executive function has been indicative of problem behaviors and social dysfunction. However, few studies have focused on the relation between peer interactions and executive function and the underlying mechanisms that may create this link. Using a national sample (n = 1164, 48.6% female) from the Study of Early Child Care and Youth Development (SECCYD), we analyzed executive function and peer problems (including victimization and rejection) across three waves within each domain (executive function or peer problems), beginning in early childhood and ending in middle adolescence. Executive function was measured as a multi-method, multi-informant composite including reports from parents on the Children's Behavior Questionnaire and Child Behavior Checklist and child's performance on behavioral tasks including the Continuous Performance Task, Woodcock-Johnson, Tower of Hanoi, Operation Span Task, Stroop, and Tower of London. Peer problems were measured as a multi-informant composite including self, teacher, and afterschool caregiver reports on multiple peer-relationship scales. Using a cross-lagged design, our Structural Equation Modeling findings suggested that experiencing peer problems contributed to lower executive function later in childhood and better executive function reduced the likelihood of experiencing peer problems later in childhood and middle adolescence, although these relations weakened as a child moves into adolescence. The results highlight that peer relationships are involved in the development of strengths and deficits in executive function and vice versa.

Linking Executive Function and Peer Problems from Early Childhood through Middle Adolescence

PubMed Central

Holmes, Christopher J.; Kim-Spoon, Jungmeen; Deater-Deckard, Kirby

2015-01-01

Peer interactions and executive function play central roles in the development of healthy children, as peer problems have been indicative of lower cognitive competencies such as self-regulatory behavior and poor executive function has been indicative of problem behaviors and social dysfunction. However, few studies have focused on the relation between peer interactions and executive function and the underlying mechanisms that may create this link. Using a national sample (n = 1,164, 48.6% female) from the Study of Early Child Care and Youth Development (SECCYD), we analyzed executive function and peer problems (including victimization and rejection) across three waves within each domain (executive function or peer problems), beginning in early childhood and ending in middle adolescence. Executive function was measured as a multi-method, multi-informant composite including reports from parents on the Children’s Behavior Questionnaire and Child Behavior Checklist and child’s performance on behavioral tasks including the Continuous Performance Task, Woodcock-Johnson, Tower of Hanoi, Operation Span Task, Stroop, and Tower of London. Peer problems were measured as a multi-informant composite including self, teacher, and after school caregiver reports on multiple peer-relationship scales. Using a cross-lagged design, our Structural Equation Modeling findings suggested that experiencing peer problems contributed to lower executive function later in childhood and better executive function reduced the likelihood of experiencing peer problems later in childhood and middle adolescence, although these relations weakened as a child moves into adolescence. The results highlight that peer relationships are involved in the development of strengths and deficits in executive function and vice versa. PMID:26096194

Strength Training for Young Athletes.

ERIC Educational Resources Information Center

Kraemer, William J.; Fleck, Steven J.

This guide is designed to serve as a resource for developing strength training programs for children. Chapter 1 uses research findings to explain why strength training is appropriate for children. Chapter 2 explains some of the important physiological concepts involved in children's growth and development as they apply to developing strength…

Sepsis Reduces Bone Strength Before Morphologic Changes Are Identifiable.

PubMed

Puthucheary, Zudin A; Sun, Yao; Zeng, Kaiyang; Vu, Lien Hong; Zhang, Zhi Wei; Lim, Ryan Z L; Chew, Nicholas S Y; Cove, Matthew E

2017-12-01

Survivors of critical illness have an increased prevalence of bone fractures. However, early changes in bone strength, and their relationship to structural changes, have not been described. We aimed to characterize early changes in bone functional properties in critical illness and their relationship to changes in bone structure, using a sepsis rodent model. Experimental study. Animal research laboratory. Adult Sprague-Dawley rats. Forty Sprague-Dawley rats were randomized to cecal ligation and puncture or sham surgery. Twenty rodents (10 cecal ligation and puncture, 10 sham) were killed at 24 hours, and 20 more at 96 hours. Femoral bones were harvested for strength testing, microCT imaging, histologic analysis, and multifrequency scanning probe microscopy. Fracture loads at the femoral neck were significantly reduced for cecal ligation and puncture-exposed rodents at 24 hours (83.39 ± 10.1 vs 103.1 ± 17.6 N; p = 0.014) and 96 hours (81.60 ± 14.2 vs 95.66 ± 14.3 N; p = 0.047). Using multifrequency scanning probe microscopy, collagen elastic modulus was lower in cecal ligation and puncture-exposed rats at 24 hours (1.37 ± 0.2 vs 6.13 ± 0.3 GPa; p = 0.001) and 96 hours (5.57 ± 0.5 vs 6.13 ± 0.3 GPa; p = 0.006). Bone mineral elastic modulus was similar at 24 hours but reduced in cecal ligation and puncture-exposed rodents at 96 hours (75.34 ± 13.2 vs 134.4 ± 8.2 GPa; p < 0.001). There were no bone architectural or bone mineral density differences by microCT. Similarly, histologic analysis demonstrated no difference in collagen and elastin staining, and C-X-C chemokine receptor type 4, nuclear factor kappa beta, and tartrate-resistant acid phosphatase immunostaining. In a rodent sepsis model, trabecular bone strength is functionally reduced within 24 hours and is associated with a reduction in collagen and mineral elastic modulus. This is likely to be the result of altered biomechanical properties, rather than increased bone mineral turnover. These data offer both mechanistic insights and may potentially guide development of therapeutic interventions.

Building Yolŋu Skills, Knowledge, and Priorities into Early Childhood Assessment and Support: Protocol for a Qualitative Study.

PubMed

Lowell, Anne; Maypilama, Elaine Lawurrpa; Fasoli, Lyn; Gundjarranbuy, Rosemary; Godwin-Thompson, Jenine; Guyula, Abbey; Yunupiŋu, Megan; Armstrong, Emily; Garrutju, Jane; McEldowney, Rose

2018-03-07

Yolngu or Yolŋu are a group of indigenous Australian people inhabiting north-eastern Arnhem Land in the Northern Territory of Australia. Recent government policy addressing disparities in outcomes between Indigenous and other children in Australia has resulted in the rapid introduction of early childhood interventions in remote Aboriginal communities. This is despite minimal research into their appropriateness or effectiveness for these contexts. This research aims to privilege Aboriginal early childhood knowledge, priorities and practices and to strengthen the evidence base for culturally responsive and relevant assessment processes and support that distinguishes "difference" from "deficit" to facilitate optimal child development. This collaborative qualitative research employs video ethnography, participant observation and in-depth interviews, involving Aboriginal families and researchers in design, implementation, interpretation and dissemination using a locally developed, culturally responsive research approach. Longitudinal case studies are being conducted with 6 families over 5 years and emerging findings are being explored with a further 50 families and key community informants. Data from all sources are analyzed inductively using a collaborative and iterative process. The study findings, grounded in an in-depth understanding of the cultural context of the study but with relevance to policy and practice more widely, are informing the development of a Web-based educational resource and targeted knowledge exchange activities. This paper focuses only on the research approach used in this project. The findings will be reported in detail in future publications. In response to community concerns about lack of recognition of Aboriginal early childhood strengths, priorities and knowledge, this collaborative community-driven project strengthens the evidence base for developing culturally responsive and relevant early childhood services and assessment processes to support optimal child development. The study findings are guiding the development of a Web-based educational resource for staff working with Aboriginal communities and families in the field of early child development. This website will also function as a community-developed tool for strengthening and maintaining Aboriginal knowledge and practice related to child development and child rearing. It will be widely accessible to community members through a range of platforms (eg, mobile phones and tablets) and will provide a model for other cultural contexts. This project will facilitate wider recognition and reflection of cultural knowledge and practice in early childhood programs and policies and will support strengthening and maintenance of cultural knowledge. The culturally responsive and highly collaborative approach to community-based research on which this project is based will also inform future research through sharing knowledge about the research process as well as research findings. ©Anne Lowell, Elaine Lawurrpa Maypilama, Lyn Fasoli, Rosemary Gundjarranbuy, Jenine Godwin-Thompson, Abbey Guyula, Megan Yunupiŋu, Emily Armstrong, Jane Garrutju, Rose McEldowney. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 07.03.2018.

Wet process shotcrete: An ecological and economical quality product for the future

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

Bracher, G.

1995-12-31

Shotcrete is an essential component of modern tunnelling and its importance is continuously growing. In order to comply with this role, the demands made on quality and economy have increased considerably. The wet process Shotcrete has been established on all the major job sites in Switzerland. Regarding the technical and ecological aspects, the introduction of an alkali free non-toxic accelerator has set up a new standard. Enormous high early strengths in combination with strength gains compared to the reference concrete can be achieved.

The VicGeneration study - a birth cohort to examine the environmental, behavioural and biological predictors of early childhood caries: background, aims and methods

PubMed Central

2010-01-01

Background Dental caries (decay) during childhood is largely preventable however it remains a significant and costly public health concern, identified as the most prevalent chronic disease of childhood. Caries in children aged less than five years (early childhood caries) is a rapid and progressive disease that can be painful and debilitating, and significantly increases the likelihood of poor child growth, development and social outcomes. Early childhood caries may also result in a substantial social burden on families and significant costs to the public health system. A disproportionate burden of disease is also experienced by disadvantaged populations. Methods/Design This study involves the establishment of a birth cohort in disadvantaged communities in Victoria, Australia. Children will be followed for at least 18 months and the data gathered will explore longitudinal relationships and generate new evidence on the natural history of early childhood caries, the prevalence of the disease and relative contributions of risk and protective biological, environmental and behavioural factors. Specifically, the study aims to: 1. Describe the natural history of early childhood caries (at ages 1, 6, 12 and 18 months), tracking pathways from early bacterial colonisation, through non-cavitated enamel white spot lesions to cavitated lesions extending into dentine. 2. Enumerate oral bacterial species in the saliva of infants and their primary care giver. 3. Identify the strength of concurrent associations between early childhood caries and putative risk and protective factors, including biological (eg microbiota, saliva), environmental (fluoride exposure) and socio-behavioural factors (proximal factors such as: feeding practices and oral hygiene; and distal factors such as parental health behaviours, physical health, coping and broader socio-economic conditions). 4. Quantify the longitudinal relationships between these factors and the development and progression of early childhood caries from age 1-18 months. Discussion There is currently a lack of research describing the natural history of early childhood caries in very young children, or exploring the interactions between risk and protective factors that extend to include contemporary measures of socio-behavioural factors. This study will generate knowledge about pathways, prevalence and preventive opportunities for early childhood caries, the most prevalent child health inequality. PMID:20181292

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

PubMed Central

Snyder-Mackler, Lynn

2010-01-01

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

Recovery of shoulder strength and proprioception after open surgery for recurrent anterior instability: a comparison of two surgical techniques.

PubMed

Rokito, Andrew S; Birdzell, Maureen Gallagher; Cuomo, Frances; Di Paola, Matthew J; Zuckerman, Joseph D

2010-06-01

Previous studies have documented a decrease in proprioceptive capacity in the unstable shoulder. The degree to which surgical approach affects recovery of strength and proprioception is unknown. The recovery of strength and proprioception after open surgery for recurrent anterior glenohumeral instability was compared for 2 surgical procedures. A prospective analysis of 55 consecutive patients with posttraumatic unilateral recurrent anterior glenohumeral instability was performed. Thirty patients (group 1) underwent an open inferior capsular shift with detachment of the subscapularis, and 25 (group 2) underwent an anterior capsulolabral reconstruction. Mean preoperative proprioception and strength values were significantly lower for the affected shoulders in both groups. At 6 months after surgery, there were no significant differences for mean strength and proprioception values between the unaffected and operative sides for group 2 patients. In group 1 patients, however, there were still significant deficits in mean position sense and strength values. Complete restoration of proprioception and strength, however, was evident by 12 months in group 1. This study demonstrates that there are significant deficits in both strength and proprioception in patients with posttraumatic, recurrent anterior glenohumeral instability. Although both are completely restored by 1 year after surgery, a subscapularis-splitting approach allows for complete recovery of strength and position sense as early as 6 months postoperatively. Detachment of the subscapularis delays recovery of strength and position sense for up to 12 months after surgery. Copyright 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Secular change in muscular strength of indigenous rural youth 6-17 years in Oaxaca, southern Mexico: 1968-2000.

PubMed

Malina, Robert M; Reyes, Maria Eugenia Peña; Tan, Swee Kheng; Little, Bertis B

2010-04-01

The study compared the grip strength of indigenous school youth 6-17 years of age in Oaxaca, southern Mexico, who were surveyed in 1968, 1978 and 2000. Grip strength (Smedley/Stoelting) was measured to 0.5 kg in 1280 children and adolescent, 621 males and 659 females, in the three surveys. Height and weight were also measured. Strength of the right and left hands was summed to provide a general estimate of muscular strength. Summed grip strength was also expressed per unit body mass (kg/kg) and height (kg/m). Subjects were classified into four age groups: 6-8 years (childhood), 9-11 years (transition in adolescence), 12-14 years (early adolescence) and 15-17 years (later adolescence). Children 6-14 years were surveyed in 1968, 1978 and 2000 while adolescents 15-17 years were surveyed in 1978 and 2000. Sex-specific MANCOVAs were used for comparisons among years within age groups. Changes in grip strength between 1968 and 1978 among children 6-14 years were small and significant only in girls. Grip strength increased, on average, between 1978 and 2000 in boys 6-17 years but only in girls 6-14 years; adolescent girls 15-17 years in 1978 were stronger than those in 2000. Secular gains in muscular strength were generally proportional to secular gains in body weight and height. The data demonstrate secular changes in muscular strength in indigenous rural youth in a community in the process of transition from subsistence level agriculture to an economy less dependent upon agriculture.

Impact of exercise-induced fatigue on the strength, postural control, and gait of children with a neuromuscular disease.

PubMed

Hart, Raphael; Ballaz, Laurent; Robert, Maxime; Pouliot, Annie; D'Arcy, Sylvie; Raison, Maxime; Lemay, Martin

2014-08-01

Children with a neuromuscular disease are prone to early muscular fatigue. The objective of the present study was to evaluate the effects of fatigue induced by a walking exercise on the strength, postural control, and gait of children with a neuromuscular disease. Maximal isometric knee strength (extension and flexion), quiet standing postural control, and gait were evaluated in 12 children (8.8 [1.4] yrs) with a neuromuscular disease before and after a walking exercise. The participants were asked to stop walking when they considered themselves "very fatigued." After the exercise-induced fatigue, a significant increase in range of motion in pelvis obliquity, hip abduction and adduction, and ankle flexion and extension during gait was reported along with an increase in stride length variability. Fatigue also reduced the knee flexor strength and had a detrimental effect on postural control. Fatigue affects the strength, postural control, and gait of children with a neuromuscular disease and could notably increase the risks of falling and the occurrence of serious injuries.

'I remember therefore I am, and I am therefore I remember': exploring the contributions of episodic and semantic self-knowledge to strength of identity.

PubMed

Haslam, Catherine; Jetten, Jolanda; Haslam, S Alexander; Pugliese, Cara; Tonks, James

2011-05-01

The present research explores the relationship between the two components of autobiographical memory--episodic and semantic self-knowledge--and identity strength in older adults living in the community and residential care. Participants (N= 32) completed the autobiographical memory interview and measures of personal identity strength and multiple group memberships. Contrary to previous research, autobiographical memory for all time periods (childhood, early adulthood, and recent life) in the semantic domain was associated with greater strength in personal identity. Further, we obtained support for the hypothesis that the relationship between episodic self-knowledge and identity strength would be mediated by knowledge of personal semantic facts. However, there was also support for a reverse mediation model indicating that a strong sense of identity is associated with semantic self-knowledge and through this may enhance self-relevant recollection. The discussion elaborates on these findings and we propose a self-knowledge and identity model (SKIM) whereby semantic self-knowledge mediates a bidirectional relationship between episodic self-knowledge and identity. ©2010 The British Psychological Society.

Influence of Iron Oxide Particles on the Strength of Ball-Milled Iron

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

Lesuer, D R; Syn, C K; Sherby, O D

2005-12-07

Detailed microstructural and mechanical property studies of ball-milled iron, in the powder and consolidated states, are reviewed and assessed. The analyses cover three and one-half orders of magnitude of grain size (from 6 nm to 20 mm) and focus on the influence of oxide particles on the strength. The study includes the early work of Koch and Yang, Kimura and Takaki and continues with the more recent work of Umemoto et al and Belyakov, Sakai et al. It is shown that the major contributors to strength are the nanooxide particles. These particles are created by adiabatic shear banding during ball-millingmore » leading to a bimodal distribution of particles. The predicted strength from particles, {sigma}{sub p}, is given by {sigma}{sub p} = B {center_dot} (D*{sub S}){sup -1/2} where D*{sub S} is the surface-to-surface interparticle spacing, and B = 395 MPa {center_dot} {micro}m{sup -1/2}. A model is proposed that accounts for the influence of the bimodal particle size distribution on strength.« less

Analysis of adolescent profiles by gender: strengths, attitudes toward violence and sexism.

PubMed

Ferragut, Marta; Blanca, Maria J; Ortiz-Tallo, Margarita

2014-02-20

The present study analyzes the profiles of boys and girls, considering gender, in the early stages of adolescence in the variables of character strengths, attitudes toward diversity and violence, and sexism. The aim is to explore the gender differences, whether the variables in each set differ from one another and whether these differences are maintained in profiles for boys and girls. The participants were 527 students (mean age = 12.21 and SD = 0.53) from the city of Málaga (Spain). Profile analysis was used to analyze data. The results, using an alpha of 0.0021 for each contrast, indicate that boys and girls differ in their character strengths, particularly in the case of girls, whose prominent strengths relate to pro-social behavior and peer relationships, where Cohen´s d are higher than .30. Moreover, boys justify attitudes of violence to a greater extent (Cohen´s d from .44 to .81) and show greater agreement with sexist beliefs (d = .63). The research suggests that it would be of interest to encourage advancement in character strengths at this age.

Do postoperative platelet-rich plasma injections accelerate early tendon healing and functional recovery after arthroscopic supraspinatus repair? A randomized controlled trial.

PubMed

Wang, Allan; McCann, Philip; Colliver, Jess; Koh, Eamon; Ackland, Timothy; Joss, Brendan; Zheng, Minghao; Breidahl, Bill

2015-06-01

Tendon-bone healing after rotator cuff repair directly correlates with a successful outcome. Biological therapies that elevate local growth-factor concentrations may potentiate healing after surgery. To ascertain whether postoperative and repeated application of platelet-rich plasma (PRP) to the tendon repair site improves early tendon healing and enhances early functional recovery after double-row arthroscopic supraspinatus repair. Randomized controlled trial; Level of evidence, 1. A total of 60 patients underwent arthroscopic double-row supraspinatus tendon repair. After randomization, half the patients received 2 ultrasound-guided injections of PRP to the repair site at postoperative days 7 and 14. Early structural healing was assessed with MRI at 16 weeks, and cuff appearances were graded according to the Sugaya classification. Functional scores were recorded with the Oxford Shoulder Score; Quick Disability of the Arm, Shoulder and Hand; visual analog scale for pain; and Short Form-12 quality-of-life score both preoperatively and at postoperative weeks 6, 12, and 16; isokinetic strength and active range of motion were measured at 16 weeks. PRP treatment did not improve early functional recovery, range of motion, or strength or influence pain scores at any time point after arthroscopic supraspinatus repair. There was no difference in structural integrity of the supraspinatus repair on MRI between the PRP group (0% full-thickness retear; 23% partial tear; 77% intact) and the control group (7% full-thickness retear; 23% partial tear; 70% intact) at 16 weeks postoperatively (P = .35). After arthroscopic supraspinatus tendon repair, image-guided PRP treatment on 2 occasions does not improve early tendon-bone healing or functional recovery. © 2015 The Author(s).

ICE telemetry performance

NASA Technical Reports Server (NTRS)

Layland, J. W.

1986-01-01

Acquiring telemetry data from the International Cometary Explorer (ICE) at its encounter with the comet Giacobini-Zinner on September 11, 1985 proved to be among the more difficult challenges the DSN has met in recent years. The ICE spacecraft began its life as an Earth orbiting monitor of the Solar Wind. At the comet, ICE was nearly 50 times as distant as in its initial role, with its signal strength diminished nearly 2500 times. Collecting enough of that weak signal to provide meaningful scientific data about the comet required unique new telemetry capabilities and special handling by the DSN. This article describes the development and validation of the DSN telemetry capability for ICE from its early planning stages through the successful comet encounter.

Dramatic reduction of void swelling by helium in ion-irradiated high purity α-iron

DOE PAGES

Bhattacharya, Arunodaya; Meslin, Estelle; Henry, Jean; ...

2018-04-11

Effect of helium on void swelling was studied in high-purity α-iron, irradiated using energetic self-ions to 157 displacements per atom (dpa) at 773 K, with and without helium co-implantation up to 17 atomic parts-per-million (appm) He/dpa. Helium is known to enhance cavity formation in metals in irradiation environments, leading to early void swelling onset. In this study, microstructure characterization by transmission electron microscopy revealed compelling evidence of dramatic swelling reduction by helium co-implantation, achieved primarily by cavity size reduction. In conclusion, a comprehensive understanding of helium induced cavity microstructure development is discussed using sink strength ratios of dislocations and cavities.

A developmental perspective on congenital muscular torticollis: a critical appraisal of the evidence.

PubMed

Tessmer, Angela; Mooney, Paula; Pelland, Lucie

2010-01-01

The aims of this review were to (1) identify and evaluate research evidence regarding the developmental outcomes of infants with congenital muscular torticollis (CMT) and (2) critically appraise and compare the outcomes of interventions targeting neck muscle extensibility and strength with those considering neck muscle function within the broader context of global infant development. An association between CMT and early developmental delay is supported by levels 3B, 4, and 5 evidence; no evidence was found of longer-term influences of CMT on the development of perceptual, cognitive, and motor skills. The effectiveness of passive manual stretching is supported by levels 2A, 3B, 4, and 5 evidence; no clear evidence was found of the effectiveness of developmentally supportive interventions. Controlled studies are needed to clarify the developmental consequences of CMT.

Objective evaluation of muscle strength in infants with hypotonia and muscle weakness.

PubMed

Reus, Linda; van Vlimmeren, Leo A; Staal, J Bart; Janssen, Anjo J W M; Otten, Barto J; Pelzer, Ben J; Nijhuis-van der Sanden, Maria W G

2013-04-01

The clinical evaluation of an infant with motor delay, muscle weakness, and/or hypotonia would improve considerably if muscle strength could be measured objectively and normal reference values were available. The authors developed a method to measure muscle strength in infants and tested 81 typically developing infants, 6-36 months of age, and 17 infants with Prader-Willi Syndrome (PWS) aged 24 months. The inter-rater reliability of the measurement method was good (ICC=.84) and the convergent validity was confirmed by high Pearson's correlations between muscle strength, age, height, and weight (r=.79-.85). A multiple linear regression model was developed to predict muscle strength based on age, height, and weight, explaining 73% of the variance in muscle strength. In infants with PWS, muscle strength was significantly decreased. Pearson's correlations showed that infants with PWS in which muscle strength was more severely affected also had a larger motor developmental delay (r=.75). Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of dental composites with reactive fillers that promote precipitation of antibacterial-hydroxyapatite layers.

PubMed

Aljabo, Anas; Abou Neel, Ensanya A; Knowles, Jonathan C; Young, Anne M

2016-03-01

The study aim was to develop light-curable, high strength dental composites that would release calcium phosphate and chlorhexidine (CHX) but additionally promote surface hydroxyapatite/CHX co-precipitation in simulated body fluid (SBF). 80 wt.% urethane dimethacrylate based liquid was mixed with glass fillers containing 10 wt.% CHX and 0, 10, 20 or 40 wt.% reactive mono- and tricalcium phosphate (CaP). Surface hydroxyapatite layer thickness/coverage from SEM images, Ca/Si ratio from EDX and hydroxyapatite Raman peak intensities were all proportional to both time in SBF and CaP wt.% in the filler. Hydroxyapatite was, however, difficult to detect by XRD until 4 weeks. XRD peak width and SEM images suggested this was due to the very small size (~10 nm) of the hydroxyapatite crystallites. Precipitate mass at 12 weeks was 22 wt.% of the sample CaP total mass irrespective of CaP wt.% and up to 7 wt.% of the specimen. Early diffusion controlled CHX release, assessed by UV spectrometry, was proportional to CaP and twice as fast in water compared with SBF. After 1 week, CHX continued to diffuse into water but in SBF, became entrapped within the precipitating hydroxyapatite layer. At 12 weeks CHX formed 5 to 15% of the HA layer with 10 to 40 wt.% CaP respectively. Despite linear decline of strength and modulus in 4 weeks from 160 to 101 MPa and 4 to 2.4 GPa, respectively, upon raising CaP content, all values were still within the range expected for commercial composites. The high strength, hydroxyapatite precipitation and surface antibacterial accumulation should reduce tooth restoration failure due to fracture, aid demineralised dentine repair and prevent subsurface carious disease respectively. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Mechanisms driving recruitment variability in fish: comparisons between the Laurentian Great Lakes and marine systems

USGS Publications Warehouse

Pritt, Jeremy J.; Roseman, Edward F.; O'Brien, Timothy P.

2014-01-01

In his seminal work, Hjort (in Fluctuations in the great fisheries of Northern Europe. Conseil Parmanent International Pour L'Exploration De La Mar. Rapports et Proces-Verbaux, 20: 1–228, 1914) observed that fish population levels fluctuated widely, year-class strength was set early in life, and egg production by adults could not alone explain variability in year-class strength. These observations laid the foundation for hypotheses on mechanisms driving recruitment variability in marine systems. More recently, researchers have sought to explain year-class strength of important fish in the Laurentian Great Lakes and some of the hypotheses developed for marine fisheries have been transferred to Great Lakes fish. We conducted a literature review to determine the applicability of marine recruitment hypotheses to Great Lakes fish. We found that temperature, interspecific interactions, and spawner effects (abundance, age, and condition of adults) were the most important factors in explaining recruitment variability in Great Lakes fish, whereas relatively fewer studies identified bottom-up trophodynamic factors or hydrodynamic factors as important. Next, we compared recruitment between Great Lakes and Baltic Sea fish populations and found no statistical difference in factors driving recruitment between the two systems, indicating that recruitment hypotheses may often be transferable between Great Lakes and marine systems. Many recruitment hypotheses developed for marine fish have yet to be applied to Great Lakes fish. We suggest that future research on recruitment in the Great Lakes should focus on forecasting the effects of climate change and invasive species. Further, because the Great Lakes are smaller and more enclosed than marine systems, and have abundant fishery-independent data, they are excellent candidates for future hypothesis testing on recruitment in fish.

Pathophysiologic insights into motor axonal function in Kennedy disease.

PubMed

Vucic, Steve; Kiernan, Matthew C

2007-11-06

Kennedy disease (KD), or spinobulbomuscular atrophy, is a slowly progressive inherited neurodegenerative disorder, marked by prominent fasciculations that typically precede the development of other symptoms. Although the genetic basis of KD relates to triplet (CAG) repeat expansion in the androgen receptor (AR) gene on the X chromosome, the mechanisms underlying the clinical presentation in KD have yet to be established. Consequently, the present study applied axonal excitability techniques to investigate the pathophysiologic mechanisms associated with KD. Peripheral nerve excitability studies were undertaken in 7 patients with KD with compound muscle action potentials (CMAP) recorded from the right abductor pollicis brevis. Strength-duration time constant (KD 0.54 +/- 0.03 msec; controls, 0.41 +/- 0.02 msec, p < 0.01) and the hyperpolarizing current/threshold gradient (KD 0.42 +/- 0.01; controls, 0.37 +/- 0.01, p < 0.05) were significantly increased in KD. Strength-duration time constant correlated with the CMAP amplitude (R = 0.68) and the fasciculation frequency (R = 0.62). Threshold electrotonus revealed greater changes in response to subthreshold depolarizing (KD TEd [90 to 100 msec], 50.75 +/- 1.98%; controls TEd [90 to 100 msec], 45.67 +/- 0.67%, p < 0.01) and hyperpolarizing (KD TEh [90 to 100 msec], 128.5 +/- 6.9%; controls TEh [90 to 100 msec], 120.5 +/- 2.4%) conditioning pulses. Measurements of refractoriness, superexcitability, and late subexcitability changed appropriately for axonal hyperpolarization, perhaps reflecting the effects of increased ectopic activity. In total, the increase in the strength-duration time constant may be the primary event, occurring early in course of the disease, contributing to the development of axonal hyperexcitability in Kennedy disease, and thereby to the generation of fasciculations, a characteristic hallmark of the disease.

Application of Strength Diagnosis.

ERIC Educational Resources Information Center

Newton, Robert U.; Dugan, Eric

2002-01-01

Discusses the various strength qualities (maximum strength, high- and low-load speed strength, reactive strength, rate of force development, and skill performance), noting why a training program design based on strength diagnosis can lead to greater efficacy and better performance gains for the athlete. Examples of tests used to assess strength…

Limb Bone Structural Proportions and Locomotor Behavior in A.L. 288-1 ("Lucy").

PubMed

Ruff, Christopher B; Burgess, M Loring; Ketcham, Richard A; Kappelman, John

2016-01-01

While there is broad agreement that early hominins practiced some form of terrestrial bipedality, there is also evidence that arboreal behavior remained a part of the locomotor repertoire in some taxa, and that bipedal locomotion may not have been identical to that of modern humans. It has been difficult to evaluate such evidence, however, because of the possibility that early hominins retained primitive traits (such as relatively long upper limbs) of little contemporaneous adaptive significance. Here we examine bone structural properties of the femur and humerus in the Australopithecus afarensis A.L. 288-1 ("Lucy", 3.2 Myr) that are known to be developmentally plastic, and compare them with other early hominins, modern humans, and modern chimpanzees. Cross-sectional images were obtained from micro-CT scans of the original specimens and used to derive section properties of the diaphyses, as well as superior and inferior cortical thicknesses of the femoral neck. A.L. 288-1 shows femoral/humeral diaphyseal strength proportions that are intermediate between those of modern humans and chimpanzees, indicating more mechanical loading of the forelimb than in modern humans, and by implication, a significant arboreal locomotor component. Several features of the proximal femur in A.L. 288-1 and other australopiths, including relative femoral head size, distribution of cortical bone in the femoral neck, and cross-sectional shape of the proximal shaft, support the inference of a bipedal gait pattern that differed slightly from that of modern humans, involving more lateral deviation of the body center of mass over the support limb, which would have entailed increased cost of terrestrial locomotion. There is also evidence consistent with increased muscular strength among australopiths in both the forelimb and hind limb, possibly reflecting metabolic trade-offs between muscle and brain development during hominin evolution. Together these findings imply significant differences in both locomotor behavior and ecology between australopiths and later Homo.

Limb Bone Structural Proportions and Locomotor Behavior in A.L. 288-1 ("Lucy")

PubMed Central

Ruff, Christopher B.; Burgess, M. Loring; Ketcham, Richard A.; Kappelman, John

2016-01-01

While there is broad agreement that early hominins practiced some form of terrestrial bipedality, there is also evidence that arboreal behavior remained a part of the locomotor repertoire in some taxa, and that bipedal locomotion may not have been identical to that of modern humans. It has been difficult to evaluate such evidence, however, because of the possibility that early hominins retained primitive traits (such as relatively long upper limbs) of little contemporaneous adaptive significance. Here we examine bone structural properties of the femur and humerus in the Australopithecus afarensis A.L. 288–1 ("Lucy", 3.2 Myr) that are known to be developmentally plastic, and compare them with other early hominins, modern humans, and modern chimpanzees. Cross-sectional images were obtained from micro-CT scans of the original specimens and used to derive section properties of the diaphyses, as well as superior and inferior cortical thicknesses of the femoral neck. A.L. 288–1 shows femoral/humeral diaphyseal strength proportions that are intermediate between those of modern humans and chimpanzees, indicating more mechanical loading of the forelimb than in modern humans, and by implication, a significant arboreal locomotor component. Several features of the proximal femur in A.L. 288–1 and other australopiths, including relative femoral head size, distribution of cortical bone in the femoral neck, and cross-sectional shape of the proximal shaft, support the inference of a bipedal gait pattern that differed slightly from that of modern humans, involving more lateral deviation of the body center of mass over the support limb, which would have entailed increased cost of terrestrial locomotion. There is also evidence consistent with increased muscular strength among australopiths in both the forelimb and hind limb, possibly reflecting metabolic trade-offs between muscle and brain development during hominin evolution. Together these findings imply significant differences in both locomotor behavior and ecology between australopiths and later Homo. PMID:27902687

Internally cured concrete for pavement and bridge deck applications : [summary].

DOT National Transportation Integrated Search

2015-08-01

High-strength-high-performance concrete (HSHPC) is used for rapid repair of concrete : bridge decks and pavement. However, HSHPC has very high early shrinkage, often leading to : cracking, made worse by high ambient temperatures and a large surface a...

Integrated Specialized Early-Course Psychosis Treatment Services - University Psychiatric Hospital Vrapce Model.

PubMed

Ostojić, DraŽenka; Čulo, Ilaria; Silić, Ante; Kos, Suzana; Savić, Aleksandar

2018-06-01

First episode of psychosis presents a critical period in terms of numerous associated risks, but also possibilities for effective therapeutic interventions. There is a continued focus on early interventions in prodromal states and early course of frank psychosis, aimed at ensuring faster remission, reducing relapses, achieving better long-term functioning, and preventing adverse outcomes linked to untreated psychosis and chronic psychotic disorders. A number of different specialized treatment models and services exist trying to close knowledge gaps and provide clinical interventions to first-episode psychosis (FEP) patients, but there is still no generally accepted standard of care informing our every-day practice. FEP and early-course psychosis specialized treatment model developed in 2004 in University Psychiatric Hospital Vrapce rests on integration of care across different organization units and clinical presentation acuity levels and patient needs (intensive care, FEP inpatient unit, FEP outpatient services including day hospital). Such integration of FEP services allows for flexible entry point on multiple levels, earlier structuring of therapeutic alliance for those requiring inpatient care, reduction of risks associated with FEP, quicker formation of long-term treatment plans, reduction of delay in accessing specialized services, and a more coordinated diagnostic process and recruitment of FEP patient population. Detailed evaluations of outcomes and comparisons with different treatment models are necessary in order to assess strengths and weaknesses of each specific model and inform modifications to current practice models.

The development of hub architecture in the human functional brain network.

PubMed

Hwang, Kai; Hallquist, Michael N; Luna, Beatriz

2013-10-01

Functional hubs are brain regions that play a crucial role in facilitating communication among parallel, distributed brain networks. The developmental emergence and stability of hubs, however, is not well understood. The current study used measures of network topology drawn from graph theory to investigate the development of functional hubs in 99 participants, 10-20 years of age. We found that hub architecture was evident in late childhood and was stable from adolescence to early adulthood. Connectivity between hub and non-hub ("spoke") regions, however, changed with development. From childhood to adolescence, the strength of connections between frontal hubs and cortical and subcortical spoke regions increased. From adolescence to adulthood, hub-spoke connections with frontal hubs were stable, whereas connectivity between cerebellar hubs and cortical spoke regions increased. Our findings suggest that a developmentally stable functional hub architecture provides the foundation of information flow in the brain, whereas connections between hubs and spokes continue to develop, possibly supporting mature cognitive function.

Reuse of Coconut Shell, Rice Husk, and Coal Ash Blends in Geopolymer Synthesis

NASA Astrophysics Data System (ADS)

Walmiki Samadhi, Tjokorde; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Rizki Fernando, Muhammad

2017-10-01

Mixtures of biomass and coal ashes are likely to be produced in increasing volume as biomass-based energy production is gaining importance in Indonesia. This work highlights the reuse of coconut shell ash (CSA), rice husk ash (RHA), and coal fly ash (FA) for geopolymer synthesis by an activator solution containing concentrated KOH and Na2SiO3. Ash blend compositions are varied according to a simplex-centroid mixture experimental design. Activator to ash mass ratios are varied from 0.8 to 2.0, the higher value being applied for ash compositions with higher Si/Al ratio. The impact of ash blend composition on early strength is adequately modeled by an incomplete quadratic mixture model. Overall, the ashes can produce geopolymer mortars with an early strength exceeding the Indonesian SNI 15-2049-2004 standard minimum value of 2.0 MPa. Good workability of the geopolymer is indicated by their initial setting times which are longer than the minimum value of 45 mins. Geopolymers composed predominantly of RHA composition exhibit poor strength and excessive setting time. FTIR spectroscopy confirms the geopolymerization of the ashes by the shift of the Si-O-Si/Al asymmetric stretching vibrational mode. Overall, these results point to the feasibility of geopolymerization as a reuse pathway for biomass combustion waste.

Performance study of cementitious systems containing zeolite and silica fume: effects of four metal nitrates on the setting time, strength and leaching characteristics.

PubMed

Gervais, C; Ouki, S K

2002-07-22

The aim of this study is to investigate the effect of four metal nitrate contaminants, namely chromium, manganese, lead and zinc on the mechanical and leaching characteristics of cement-based materials. For this purpose, three different matrices made of: (i) Portland cement, (ii) Portland cement and silica fume, and (iii) Portland cement and natural zeolite were studied. The effects of metals on the stabilised/solidified (S/S) product characteristics were monitored by measuring: (i) setting time, (ii) compressive strength, (iii) acid neutralisation capacity (ANC), and (iv) solubility of the metal contaminants as a function of pH. The results of both mechanical and leaching tests showed the importance of the contaminant/matrix couple considered. Setting time was accelerated in presence of chromium, while in presence of manganese, lead and zinc it was delayed. However, for the last two contaminants, a 10% replacement of cement by silica fume and zeolite, markedly accelerated the setting time compared to the cement-only matrix. Although the early strength development was adversely affected in presence of all four contaminants, the long-term strength was less affected compared to the control materials. Although the ANC of the materials was not markedly affected by the presence of contaminants, the nature of the matrix did modify the ANC behaviour of the solidified materials. The increased strength and reduced ANC observed in the presence of silica fume are both due to pozzolanic reaction. The type of matrix used for solidification did not affect the solubility of the four metal contaminants. Overall, the results showed that the use of blended cements must be carried out with care and the performance assessment of waste-containing cement-based materials must take into consideration both the mechanical and leaching characteristics of the systems.

Modeling of Filament Deposition Rapid Prototyping Process with a Closed form Solution

NASA Astrophysics Data System (ADS)

Devlin, Steven Leon

Fused Deposition Modeling (FDM(TM)) or fused filament fabrication (FFF) systems are extrusion-based technologies used to produce functional or near functional parts from a wide variety of plastic materials. First patented by S. Scott Crump and commercialized by Stratasys, Ltd in the early 1990s, this technology, like many additive manufacturing systems, offers significant opportunities for the design and production of complex part structures that are difficult if not impossible to produce using traditional manufacturing methods. Standing on the shoulders of a twenty-five year old invention, a rapidly growing open-source development community has exponentially driven interest in FFF technology. However, part quality often limits use in final product commercial markets. Development of accurate and repeatable methods for determining material strength in FFF produced parts is essential for wide adoption into mainstream manufacturing. This study builds on the empirical, squeeze flow and intermolecular diffusion model research conducted by David Grewell and Avraham Benatar, applying a combined model to predict auto adhesion or healing to FFF part samples. In this research, an experimental study and numerical modeling were performed in order to drive and validate a closed form heat transfer solution for extrusion processes to develop temperature field models. An extrusion-based 3D printing system, with the capacity to vary deposition speeds and temperatures, was used to fabricate the samples. Standardized specimens of Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) filament were used to fabricate the samples with different speeds and temperatures. Micro-scanning of cut and lapped specimens, using an optical microscope, was performed to find the effect of the speed and the temperature on the geometry of the cross-sections. It was found that by increasing the speed of the extrusion printing, the area of the cross-section and the maximum thickness decrease, while the weld/bead geometry minimum thickness increases at higher speeds, although actual part strength appeared to plateau for speeds above 15mm/sec. Temperature effect was found to increase the geometry minimum thickness. In most cases, test results show that by increasing the speed and the temperature, the geometry strength increases. Non-Linear finite element based numerical modeling was performed to predict the strength of the samples. The geometry produced from the optical microscope scanning and typical PLA material properties were used to create the model. The finite element model was able to predict the strength of the tested samples at different speeds and temperatures. Analysis of resulting data and examination of tested samples offer favorable insights and opportunities for additional and continuing investigation.

The effect of yield strength and ductility to fatigue damage

NASA Technical Reports Server (NTRS)

Yeh, H. Y.

1973-01-01

The cumulative damage of aluminium alloys with different yield strength and various ductility due to seismic loads was studied. The responses of an idealized beam with a centered mass at one end and fixed at the other end to El Centro's and Taft's earthquakes are computed by assuming that the alloys are perfectly elastoplastic materials and by using numerical technique. Consequently, the corresponding residual plastic strain can be obtained from the stress-strain relationship. The revised Palmgren-Miner cumulative damage theorem is utilized to calculate the fatigue damage. The numerical results show that in certain cases, the high ductility materials are more resistant to seismic loads than the high yield strength materials. The results also show that if a structure collapse during the earthquake, the collapse always occurs in the very early stage.

Fatigue of Austempered Ductile Iron with Two Strength Grades in Very High Cycle Regime

NASA Astrophysics Data System (ADS)

Zhang, Jiwang; Li, Wei; Song, Qingpeng; Zhang, Ning; Lu, Liantao

2016-03-01

In this study, Austempered ductile irons (ADIs) with two different strength grades were produced and the fatigue properties were measured at 109 cycles. The results show that the S-N curves give a typical step-wise shape and there is no fatigue limit in the very high cycle fatigue regime. The two grades ADI have the similar fracture behaviors and fatigue failure can initiate from defects at specimen surface and subsurface zone. On the fracture surfaces of some specimens, the `granular-bright-facet' area with rich carbon distribution is observed in the vicinity of the defect. The microstructure affects the crack behaviors at the early propagation stage. The ADI with upper and lower bainite shows higher fatigue strength compared with the ADI with coarse upper bainite.

Fatigue of graphite/epoxy /0/90/45/-45/s laminates under dual stress levels

NASA Technical Reports Server (NTRS)

Yang, J. N.; Jones, D. L.

1982-01-01

A model for the prediction of loading sequence effects on the statistical distribution of fatigue life and residual strength in composite materials is generalized and applied to (0/90/45/-45)s graphite/epoxy laminates. Load sequence effects are found to be caused by both the difference in residual strength when failure occurs (boundary effect) and the effect of previously applied loads (memory effect). The model allows the isolation of these two effects, and the estimation of memory effect magnitudes under dual fatigue loading levels. It is shown that the material memory effect is insignificant, and that correlations between predictions of the number of early failures agree with the verification tests, as do predictions of fatigue life and residual strength degradation under dual stress levels.

Starbursts and Wispy Drops : Surfactants Spreading on Gel Substrates

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Shomeek; Daniels, Karen; Behringer, Robert

2005-11-01

We report a phase diagram for a novel instability seen in drops of nonionic surfactant solution (Triton X-305) spreading on viscoelastic agar gel substrate . This system allows us to examine the effect of varying the effective fluidity/stiffness of aqueous substrates. The morphology is strongly affected by the substrate fluidity, ranging from spreading starbursts of arms on weak gels, to wispy drops on intermediate strength gels, to circular drops on stiff gels. We analyze the dynamics of spreading in the starburst phase, where the arm length grows as t ^3/4 at early times, independent of the gel strength and surfactant concentration. The number of arms is proportional to the surfactant concentration and inversely proportional to the gel strength. Ongoing work is exploring the effects of changing the drop volume.

Characterising Atlantic deep waters during the extreme warmth of the early Eocene 'greenhouse'.

NASA Astrophysics Data System (ADS)

Cameron, A.; Sexton, P. F.; Anand, P.; Huck, C. E.; Fehr, M.; Dickson, A.; Scher, H. D.; van de Flierdt, T.; Westerhold, T.; Roehl, U.

2014-12-01

The meridional overturning circulation (MOC) is a planetary-scale oceanic flow that is of direct importance to the climate system because it transports heat, salt and nutrients to high latitudes and regulates the exchange of CO2 with the atmosphere. The Atlantic Ocean plays a strong role in the modern day MOC however, it is unclear what role it may have played during extreme climate conditions such as those found in the early Eocene 'greenhouse'. In order to resolve the Atlantic's role in the MOC during the early/middle Eocene, we present a multi-proxy approach to investigate changes in ocean circulation, water mass geometry, sediment supply to the deep oceans and the physical strength of deep waters from four different IODP drill sites. Neodymium isotopes (ɛNd), REE profiles and cerium anomalies measured in fossilised fish teeth help to characterise geochemical changes to water masses throughout the Atlantic whilst bulk sediment ɛNd and XRF-core scan data documents changes in sediment supply to the region. Sortable silt data provides a physical constraint on the strength of deep-water movements during the extreme climatic conditions of the early Eocene. We utilise expanded and continuous sequences from two sites in the North west Atlantic spanning the early to middle Eocene recently recovered on IODP Exp. 342 (1403, 1409) that are located on the Newfoundland Ridge, directly in the flow path of today's Deep Western Boundary Current. We also present data from equatorial Demerara Rise (IODP site 1258) and from further north at the mouth of the Labrador Sea (ODP Site 647).

A randomized controlled trial on early physiotherapy intervention versus usual care in acute care unit for elderly: potential benefits in light of dietary intakes.

PubMed

Blanc-Bisson, C; Dechamps, A; Gouspillou, G; Dehail, P; Bourdel-Marchasson, I

2008-01-01

To evaluate effects of early intensive physiotherapy during acute illness on post hospitalization activity daily living autonomy (ADL). Prospective randomized controlled trial of intensive physiotherapy rehabilitation on day 1 to 2 after admission until clinical stability or usual care. acute care geriatric medicine ward. A total of 76 acutely ill patients, acutely bedridden or with reduced mobility but who were autonomous for mobility within the previous 3 months. Patients in palliative care or with limiting mobility pathology were excluded. Mean age was 85.4 (SD 6.6) years. At admission, at clinical stability and one month later: anthropometry, energy and protein intakes, hand grip strength, ADL scores, and baseline inflammatory parameters. An exploratory principal axis analysis was performed on the baseline characteristics and general linear models were used to explore the course of ADL and nutritional variables. A 4-factor solution was found explaining 71.7% of variance with a factor "nutrition", a factor "function" (18.8% of variance) for ADL, handgrip strength, bedridden state, energy and protein intakes, serum albumin and C-reactive protein concentrations; a factor "strength" and a fourth factor . During follow-up, dietary intakes, handgrip strength, and ADL scores improved but no changes occurred for anthropometric variables. Intervention was associated only with an increase in protein intake. Better improvement in ADL was found in intervention group when model was adjusted on "function" factor items. Physical intervention programs should be proposed according to nutritional intakes with the aim of preventing illness induced disability.

Connectivity strength-weighted sparse group representation-based brain network construction for MCI classification.

PubMed

Yu, Renping; Zhang, Han; An, Le; Chen, Xiaobo; Wei, Zhihui; Shen, Dinggang

2017-05-01

Brain functional network analysis has shown great potential in understanding brain functions and also in identifying biomarkers for brain diseases, such as Alzheimer's disease (AD) and its early stage, mild cognitive impairment (MCI). In these applications, accurate construction of biologically meaningful brain network is critical. Sparse learning has been widely used for brain network construction; however, its l 1 -norm penalty simply penalizes each edge of a brain network equally, without considering the original connectivity strength which is one of the most important inherent linkwise characters. Besides, based on the similarity of the linkwise connectivity, brain network shows prominent group structure (i.e., a set of edges sharing similar attributes). In this article, we propose a novel brain functional network modeling framework with a "connectivity strength-weighted sparse group constraint." In particular, the network modeling can be optimized by considering both raw connectivity strength and its group structure, without losing the merit of sparsity. Our proposed method is applied to MCI classification, a challenging task for early AD diagnosis. Experimental results based on the resting-state functional MRI, from 50 MCI patients and 49 healthy controls, show that our proposed method is more effective (i.e., achieving a significantly higher classification accuracy, 84.8%) than other competing methods (e.g., sparse representation, accuracy = 65.6%). Post hoc inspection of the informative features further shows more biologically meaningful brain functional connectivities obtained by our proposed method. Hum Brain Mapp 38:2370-2383, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Dissolved Massive Metal-rich Globular Clusters Can Cause the Range of UV Upturn Strengths Found among Early-type Galaxies

NASA Astrophysics Data System (ADS)

Goudfrooij, Paul

2018-04-01

I discuss a scenario in which the ultraviolet (UV) upturn of giant early-type galaxies (ETGs) is primarily due to helium-rich stellar populations that formed in massive metal-rich globular clusters (GCs), which subsequently dissolved in the strong tidal field in the central regions of the massive host galaxy. These massive GCs are assumed to show UV upturns similar to those observed recently in M87, the central giant elliptical galaxy in the Virgo cluster of galaxies. Data taken from the literature reveal a strong correlation between the strength of the UV upturn and the specific frequency of metal-rich GCs in ETGs. Adopting a Schechter function parameterization of GC mass functions, simulations of long-term dynamical evolution of GC systems show that the observed correlation between UV upturn strength and GC specific frequency can be explained by variations in the characteristic truncation mass {{ \\mathcal M }}{{c}} such that {{ \\mathcal M }}{{c}} increases with ETG luminosity in a way that is consistent with observed GC luminosity functions in ETGs. These findings suggest that the nature of the UV upturn in ETGs and the variation of its strength among ETGs are causally related to that of helium-rich populations in massive GCs, rather than intrinsic properties of field stars in massive galactic spheroids. With this in mind, I predict that future studies will find that [N/Fe] decreases with increasing galactocentric radius in massive ETGs, and that such gradients have the largest amplitudes in ETGs with the strongest UV upturns.

ASSOCIATION BETWEEN LONG-TERM QUADRICEPS WEAKNESS AND EARLY WALKING MUSCLE CO-CONTRACTION AFTER TOTAL KNEE ARTHROPLASTY

PubMed Central

Yoshida, Yuri; Mizner, Ryan L.; Snyder-Mackler, Lynn

2013-01-01

INTRODUCTION Quadriceps weakness is one of the primary post-operative impairments that persist long term for patients after total knee arthroplasty (TKA). We hypothesized that early gait muscle recruitment patterns of the quadriceps and hamstrings with diminished knee performance at 3 months after surgery would be related to long-term quadriceps strength at one year after TKA. METHODS Twenty-one subjects who underwent primary unilateral TKA and 14 age-matched healthy controls were analyzed. At three months after TKA, the maximum voluntary isometric contraction of quadriceps and a comprehensive gait analysis were performed. Quadriceps strength was assessed again at one year after surgery. RESULTS Quadriceps muscle recruitment of the operated limb was greater than the non-operated limb during the loading response of gait (p=0.03), but there were no significant differences in hamstring recruitment or co-contraction between limbs (p>0.05). There were significant differences in quadriceps muscle recruitment during gait between the non-operated limb of TKA group and healthy control group (p<0.05). The TKA group showed a significant inverse relationship between one year quadriceps strength and co-contraction (r = −0.543) and hamstring muscle recruitment (r = −0.480) during loading response at 3 months after TKA. CONCLUSIONS The results revealed a reverse relationship where stronger patients tended to demonstrate lower quadriceps recruitment at 3 months post-surgery that was not observed in the healthy peer group. The altered neuromuscular patterns of quadriceps and hamstrings during gait may influence chronic quadriceps strength in individuals after TKA. PMID:23352711

Longitudinal Reciprocal Relationships between Discrimination and Ethnic Affect or Depressive Symptoms among Chinese American Adolescents

PubMed Central

Hou, Yang; Kim, Su Yeong; Wang, Yijie; Shen, Yishan; Orozco-Lapray, Diana

2015-01-01

Discrimination plays an important role in the development of ethnic minority adolescents. However, previous studies have often adopted a unidirectional model examining the influence of discrimination on adolescent development, thus leaving the potential reciprocal relationship between them understudied. Moreover, there is a dearth of studies on Chinese Americans in the discrimination literature. Therefore, this study aimed to examine the reciprocal relationships between discrimination and two measures of adolescent outcomes (i.e., ethnic affect and depressive symptoms) from early adolescence to emerging adulthood in Chinese Americans. Participants were 444 adolescents (54% female), followed at four-year intervals, beginning at 7th or 8th grade (Mage.wave1 = 13.03) in 2002, for a total of three waves. An examination of cross-lagged autoregressive models revealed two major findings. First, in contrast to the rejection–identification model, perceived discrimination at early adolescence negatively related to ethnic affect at middle adolescence. Conversely, ethnic affect at early adolescence also negatively related to discrimination at middle adolescence. These results held the same direction but became insignificant from middle adolescence to emerging adulthood. Second, perceived discrimination positively related to depressive symptoms across the studied developmental periods, and depressive symptoms positively related to perceived discrimination from middle adolescence to emerging adulthood. The strength of these longitudinal relationships did not change significantly across developmental periods or gender. These findings highlight the bidirectional relationship between perceived discrimination and adolescent outcomes; they also demonstrate the value of studying the discrimination experiences of Chinese Americans. PMID:25963446

Childhood Cognitive Ability and Age-Related Changes in Physical Capability From Midlife: Findings From a British Birth Cohort Study.

PubMed

Cooper, Rachel; Richards, Marcus; Kuh, Diana

2017-09-01

The aim of the study was to test the hypothesis that higher childhood cognitive ability is associated with reduced risk of decline in physical capability in late midlife. Participants were 1954 men and women from the Medical Research Council National Survey of Health and Development with complete data on cognitive ability at age of 15 years and measures of grip strength and chair rise speed at ages of 53 and 60 to 64 years. Using multinomial logistic regression, associations of childhood cognitive ability with categories of change in grip strength and chair rise speed (i.e., decline, stable high, stable low, reference) were investigated. Adjustments were made for potential confounders from early life and adult mediators including health behaviors, educational level, and cognitive ability at age of 53 years. Higher childhood cognitive scores were associated with reduced risks of decline in grip strength and chair rise speed, for example, the sex-adjusted relative-risk ratio of decline (versus reference) in grip strength per 1SD increase in childhood cognitive score was 0.82 (95% confidence interval = 0.73-0.92). Higher childhood cognitive scores were also associated with reduced risk of stable low and increased likelihood of stable high chair rise speed. These findings suggest that childhood cognitive ability may be related to decline in physical capability in late midlife. A number of life course pathways are implicated, including those linking childhood and adult cognitive ability. Future research aiming to identify new opportunities to prevent or minimize age-related declines in physical capability may benefit from considering the potential role of neurodevelopmental as well as neurodegenerative pathways.

Ontogenetic changes in limb bone structural proportions in mountain gorillas (Gorilla beringei beringei).

PubMed

Ruff, Christopher B; Burgess, M Loring; Bromage, Timothy G; Mudakikwa, Antoine; McFarlin, Shannon C

2013-12-01

Behavioral studies indicate that adult mountain gorillas (Gorilla beringei) are the most terrestrial of all nonhuman hominoids, but that infant mountain gorillas are much more arboreal. Here we examine ontogenetic changes in diaphyseal strength and length of the femur, tibia, humerus, radius, and ulna in 30 Virunga mountain gorillas, including 18 immature specimens and 12 adults. Comparisons are also made with 14 adult western lowland gorillas (Gorilla gorilla gorilla), which are known to be more arboreal than adult mountain gorillas. Infant mountain gorillas have significantly stronger forelimbs relative to hind limbs than older juveniles and adults, but are nonsignificantly different from western lowland gorilla adults. The change in inter-limb strength proportions is abrupt at about two years of age, corresponding to the documented transition to committed terrestrial quadrupedalism in mountain gorillas. The one exception is the ulna, which shows a gradual increase in strength relative to the radius and other long bones during development, possibly corresponding to the gradual adoption of stereotypical fully pronated knuckle-walking in older juvenile gorillas. Inter-limb bone length proportions show a contrasting developmental pattern, with hind limb/forelimb length declining rapidly from birth to five months of age, and then showing no consistent change through adulthood. The very early change in length proportions, prior to significant independent locomotion, may be related to the need for relatively long forelimbs for climbing in a large-bodied hominoid. Virunga mountain gorilla older juveniles and adults have equal or longer forelimb relative to hind limb bones than western lowland adults. These findings indicate that both ontogenetically and among closely related species of Gorilla, long bone strength proportions better reflect actual locomotor behavior than bone length proportions. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Effect of Strengths Awareness and Development on the Self-Efficacy of Teachers

ERIC Educational Resources Information Center

Griffin, Lauren Elyse

2016-01-01

Increasing teacher efficacy poses challenges to educational leaders, highlighting the need for a study of the awareness and development of strengths related to teacher efficacy. The purpose of the current study was to examine the effect of the awareness and development of strengths on teachers' perceived self-efficacy, as well as to determine if…

Social cognition and conduct problems: a developmental approach.

PubMed

Oliver, Bonamy R; Barker, Edward D; Mandy, William P L; Skuse, David H; Maughan, Barbara

2011-04-01

To estimate associations between trajectories of conduct problems and social-cognitive competences through childhood into early adolescence. A prospective population-based cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC) recruited in the prenatal period (13,988 children alive at 12 months) formed the basis for the current study. Socio-emotional and pragmatic language competences were examined in relation to conduct problem development in a group of 6,047 children with no known autistic-spectrum disorders. Specifically, conduct problem trajectories (low, childhood-limited, adolescent-onset, and early-onset persistent) identified using maternal prospective reports (Strengths and Difficulties Questionnaire: ages 4 through 13 years) were contrasted. Demographic confounders, child verbal IQ and other psychopathologies were controlled. In contrast to individuals with low conduct problem levels, all conduct problem groups presented with difficulties in both social-cognitive domains. Deficits among those with early-onset persistent conduct problems were particularly apparent: 40.6% of boys and 24.3% of girls with persistent conduct problems met impairment criteria for one or other social-cognitive domain. Associations remained robust after controlling for demographic confounders (maternal age at birth, low SES, maternal education), child verbal IQ, and internalizing and inattention symptoms. For boys, results indicated that overlaps with overactivity symptoms may contribute problems with pragmatic language; this was not the case for girls or for socio-emotional difficulties. Findings have far-reaching implications for children with conduct problems, particularly those with early onset and persistent difficulties. Traditional parent training interventions are likely to be bolstered by strategies that help to develop the social competences of these children. Copyright © 2011 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Late Jurassic-Early Cretaceous episodic development of the Bangong Meso-Tethyan subduction: Evidence from elemental and Sr-Nd isotopic geochemistry of arc magmatic rocks, Gaize region, central Tibet, China

NASA Astrophysics Data System (ADS)

Zhang, Yu-Xiu; Li, Zhi-Wu; Yang, Wen-Guang; Zhu, Li-Dong; Jin, Xin; Zhou, Xiao-Yao; Tao, Gang; Zhang, Kai-Jun

2017-03-01

The Bangong Meso-Tethys plays a critical role in the development of the Tethyan realm and the initial elevation of the Tibetan Plateau. However, its precise subduction polarity, and history still remain unclear. In this study, we synthesize a report for the Late Jurassic-Early Cretaceous two-phase magmatic rocks in the Gaize region at the southern margin of the Qiangtang block located in central Tibet. These rocks formed during the Late Jurassic-earliest Cretaceous (161-142 Ma) and Early Cretaceous (128-106 Ma), peaking at 146 Ma and 118 Ma, respectively. The presence of inherited zircons indicates that an Archean component exists in sediments in the shallow Qiangtang crust, and has a complex tectonomagmatic history. Geochemical and Sr-Nd isotopic data show that the two-phase magmatic rocks exhibit characteristics of arc magmatism, which are rich in large-ion incompatible elements (LIIEs), but are strongly depleted in high field strength elements (HFSEs). The Late Jurassic-earliest Cretaceous magmatic rocks mixed and mingled among mantle-derived mafic magmas, subduction-related sediments, or crustally-derived felsic melts and fluids, formed by a northward and steep subduction of the Bangong Meso-Tethys ocean crust. The magmatic gap at 142-128 Ma marks a flat subduction of the Meso-Tethys. The Early Cretaceous magmatism experienced a magma MASH (melting, assimilation, storage, and homogenization) process among mantle-derived mafic magmas, or crustally-derived felsic melts and fluids, as a result of the Meso-Tethys oceanic slab roll-back, which triggered simultaneous back-arc rifting along the southern Qiangtang block margin.

Characterization of Depleted-Uranium Strength and Damage Behavior

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

Gray, III, George T.; Chen, Shuh-Rong; Bronkhorst, Curt A.

2012-12-17

The intent of this report is to document the status of our knowledge of the mechanical and damage behavior of Depleted Uranium(DU hereafter). This report briefly summaries the motivation of the experimental and modeling research conducted at Los Alamos National Laboratory(LANL) on DU since the early 1980’s and thereafter the current experimental data quantifying the strength and damage behavior of DU as a function of a number of experimental variables including processing, strain rate, temperature, stress state, and shock prestraining. The effect of shock prestraining on the structure-property response of DU is described and the effect on post-shock mechanical behaviormore » of DU is discussed. The constitutive experimental data utilized to support the derivation of two constitutive strength (plasticity) models, the Preston-Tonks-Wallace (PTW) and Mechanical Threshold Stress (MTS) models, for both annealed and shock prestrained DU are detailed and the Taylor cylinder validation tests and finite-element modeling (FEM) utilized to validate these strength models is discussed. The similarities and differences in the PTW and MTS model descriptions for DU are discussed for both the annealed and shock prestrained conditions. Quasi-static tensile data as a function of triaxial constraint and spallation test data are described. An appendix additionally briefly describes low-pressure equation-of-state data for DU utilized to support the spallation experiments. The constitutive behavior of DU screw/bolt material is presented. The response of DU subjected to dynamic tensile extrusion testing as a function of temperature is also described. This integrated experimental technique is planned to provide an additional validation test in the future. The damage data as a function of triaxiality, tensile and spallation data, is thereafter utilized to support derivation of the Tensile Plasticity (TEPLA) damage model and simulations for comparison to the DU spallation data are presented. Finally, a discussion of future needs in the area of needed DU strength and damage research at LANL is presented to support the development of physically-based predictive strength and damage modeling capability.« less

Use of fiber reinforced concrete for concrete pavement slab replacement.

DOT National Transportation Integrated Search

2014-03-01

Unlike ordinary concrete pavement, replacement concrete slabs need to be open to traffic within 24 hours (sooner in : some cases). Thus, high early-strength concrete is used; however, it frequently cracks prematurely as a result of high : heat of hyd...

Strengths-based positive psychology interventions: a randomized placebo-controlled online trial on long-term effects for a signature strengths- vs. a lesser strengths-intervention.

PubMed

Proyer, René T; Gander, Fabian; Wellenzohn, Sara; Ruch, Willibald

2015-01-01

Recent years have seen an increasing interest in research in positive psychology interventions. There is broad evidence for their effectiveness in increasing well-being and ameliorating depression. Intentional activities that focus on those character strengths, which are most typical for a person (i.e., signature strengths, SS) and encourage their usage in a new way have been identified as highly effective. The current study aims at comparing an intervention aimed at using SS with one on using individual low scoring (or lesser) strengths in a randomized placebo-controlled trial. A total of 375 adults were randomly assigned to one of the two intervention conditions [i.e., using five signature vs. five lesser strengths (LS) in a new way] or a placebo control condition (i.e., early memories). We measured happiness and depressive symptoms at five time points (i.e., pre- and post-test, 1-, 3-, and 6-months follow-ups) and character strengths at pre-test. The main findings are that (1) there were increases in happiness for up to 3 months and decreases in depressive symptoms in the short term in both intervention conditions; (2) participants found working with strengths equally rewarding (enjoyment and benefit) in both conditions; (3) those participants that reported generally higher levels of strengths benefitted more from working on LS rather than SS and those with comparatively lower levels of strengths tended to benefit more from working on SS; and (4) deviations from an average profile derived from a large sample of German-speakers completing the Values-in-Action Inventory of Strengths were associated with greater benefit from the interventions in the SS-condition. We conclude that working on character strengths is effective for increasing happiness and discuss how these interventions could be tailored to the individual for promoting their effectiveness.

Strength Training Following Hematopoietic Stem Cell Transplantation

PubMed Central

Hacker, Eileen Danaher; Larson, Janet; Kujath, Amber; Peace, David; Rondelli, Damiano; Gaston, Lisa

2010-01-01

Background Patients receiving high-dose chemotherapy and hematopoietic stem cell transplantation (HSCT) experience considerable reductions in physical activity and deterioration of their health status. Objective The purpose of this pilot study was to test the effects of strength training compared to usual activity on physical activity, muscle strength, fatigue, health status perceptions, and quality of life following HSCT. Interventions/Methods Nineteen subjects were randomized to the exercise or control group. Moderate intensity strength training began following discharge from the hospital. Dependent variables included physical activity, muscle strength, fatigue, health status perceptions and quality of life. Variables were measured prior to admission to the hospital for HSCT, day 8 following HSCT, and six weeks following discharge from the hospital. Results Significant time effects were noted for many variables with anticipated declines in physical activity, muscle strength, fatigue, and health status perceptions immediately after HSCT with subsequent improvements six weeks following hospital discharge. One group effect was noted with subjects in the exercise group reporting less fatigue than subjects in the control group. Although no significant interactions were detected, the trends suggest that the exercise group may be more physically active following the intervention compared to the usual activity group. Conclusions This study demonstrates the potential positive effects of strength training on physical activity, fatigue, and quality of life in people receiving high-dose chemotherapy and HSCT. Implications for Practice Preliminary evidence is provided for using strength training to enhance early recovery following HSCT. Elastic resistance bands are easy to use and relatively inexpensive. PMID:21116175

Emergence of Rich-Club Topology and Coordinated Dynamics in Development of Hippocampal Functional Networks In Vitro

PubMed Central

Charlesworth, Paul; Kitzbichler, Manfred G.; Paulsen, Ole

2015-01-01

Recent studies demonstrated that the anatomical network of the human brain shows a “rich-club” organization. This complex topological feature implies that highly connected regions, hubs of the large-scale brain network, are more densely interconnected with each other than expected by chance. Rich-club nodes were traversed by a majority of short paths between peripheral regions, underlining their potential importance for efficient global exchange of information between functionally specialized areas of the brain. Network hubs have also been described at the microscale of brain connectivity (so-called “hub neurons”). Their role in shaping synchronous dynamics and forming microcircuit wiring during development, however, is not yet fully understood. The present study aimed to investigate the role of hubs during network development, using multi-electrode arrays and functional connectivity analysis during spontaneous multi-unit activity (MUA) of dissociated primary mouse hippocampal neurons. Over the first 4 weeks in vitro, functional connectivity significantly increased in strength, density, and size, with mature networks demonstrating a robust modular and small-world topology. As expected by a “rich-get-richer” growth rule of network evolution, MUA graphs were found to form rich-clubs at an early stage in development (14 DIV). Later on, rich-club nodes were a consistent topological feature of MUA graphs, demonstrating high nodal strength, efficiency, and centrality. Rich-club nodes were also found to be crucial for MUA dynamics. They often served as broker of spontaneous activity flow, confirming that hub nodes and rich-clubs may play an important role in coordinating functional dynamics at the microcircuit level. PMID:25855164

The influence of calcium nitrate on setting and hardening rate of Portland cement concrete at different temperatures

NASA Astrophysics Data System (ADS)

Kičaitė, A.; Pundienė, I.; Skripkiūnas, G.

2017-10-01

Calcium nitrate in mortars and concrete is used as a multifunctional additive: as set accelerator, plasticizer, long term strength enhancer and as antifreeze admixture. Used binding material and the amount of calcium nitrate, affect the characteristics of the concrete mixture and strength of hardened concrete. The setting time of the initial and the final binding at different temperatures of hardening (+ 20 °C and + 5 °C) of the pastes made of different cements (Portland cement CEM I 42.5 R and Portland limestone cement CEM II/A-LL 42.5 R) and various amounts of calcium nitrate from 1 % until 3 % were investigated. The effect of calcium nitrate on technological characteristics of concrete mixture (the consistency of the mixture, the density, and the amount of air in the mixture), on early concrete strength after 2 and 7 days, as well as on standard concrete strength after 28 days at different temperatures (at + 20 °C and + 5 °C) were analysed.

Lamination residual stresses in hybrid composites, part 1

NASA Technical Reports Server (NTRS)

Daniel, I. M.; Liber, T.

1976-01-01

An experimental investigation was conducted to study lamination residual stresses for various material and loading parameters. The effects of hybridization on residual stresses and residual properties after thermal cycling under load were determined in angle-ply graphite/Kevlar/epoxy and graphite/S-glass/epoxy laminates. Residual strains in the graphite plies are not appreciably affected by the type and number of hybridizing plies. Computed residual stresses at room temperature in the S-glass plies reach values up to seventy-five percent of the transverse strength of the material. Computed residual stresses in the graphite plies exceed the static strength by approximately ten percent. In the case of Kevlar plies, computed residual stresses far exceed the static strength indicating possible early failure of these plies. Static testing of the hybrids above indicates that failure is governed by the ultimate strain of the graphite plies. In thermally cycled hybrids, in general, residual moduli were somewhat lower and residual strengths were higher than initial values.

Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union.

PubMed

Jones, Thomas W; Smith, Andrew; Macnaughton, Lindsay S; French, Duncan N

2016-12-01

Jones, TW, Smith, A, Macnaughton, LS, and French, DN. Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union. J Strength Cond Res 30(12): 3354-3366, 2016-There is limited published research on strength and conditioning (S&C) practices in elite rugby union (RU). Information regarding testing batteries and programme design would provide valuable information to both applied practitioners and researchers investigating the influence of training interventions or preperformance strategies. The aim of this study was to detail the current practices of S&C coaches and sport scientists working in RU. A questionnaire was developed that comprised 7 sections: personal details, physical testing, strength and power development, concurrent training, flexibility development, unique aspects of the programme, and any further relevant information regarding prescribed training programmes. Forty-three (41 men, 2 women; age: 33.1 ± 5.3 years) of 52 (83%) coaches responded to the questionnaire. The majority of practitioners worked with international level and/or professional RU athletes. All respondents believed strength training benefits RU performance and reported that their athletes regularly performed strength training. The clean and back squat were rated the most important prescribed exercises. Forty-one (95%) respondents reported prescribing plyometric exercises and 38 (88%) indicated that periodization strategies were used. Forty-two (98%) practitioners reported conducting physical testing, with body composition being the most commonly tested phenotype. Thirty-three (77%) practitioners indicated that the potential muted strength development associated with concurrent training was considered when programming and 27 (63%) believed that strength before aerobic training was more favorable for strength development than vice versa. This research represents the only published survey to date of S&C practices in northern and southern hemisphere RU.

Empathy as a "risky strength": a multilevel examination of empathy and risk for internalizing disorders.

PubMed

Tone, Erin B; Tully, Erin C

2014-11-01

Learning to respond to others' distress with well-regulated empathy is an important developmental task linked to positive health outcomes and moral achievements. However, this important interpersonal skill set may also confer risk for depression and anxiety when present at extreme levels and in combination with certain individual characteristics or within particular contexts. The purpose of this review is to describe an empirically grounded theoretical rationale for the hypothesis that empathic tendencies can be "risky strengths." We propose a model in which typical development of affective and cognitive empathy can be influenced by complex interplay among intraindividual and interindividual moderators that increase risk for empathic personal distress and excessive interpersonal guilt. These intermediate states in turn precipitate internalizing problems that map onto empirically derived fear/arousal and anhedonia/misery subfactors of internalizing disorders. The intraindividual moderators include a genetically influenced propensity toward physiological hyperarousal, which is proposed to interact with genetic propensity to empathic sensitivity to contribute to neurobiological processes that underlie personal distress responses to others' pain or unhappiness. This empathic personal distress then increases risk for internalizing problems, particularly fear/arousal symptoms. In a similar fashion, interactions between genetic propensities toward negative thinking processes and empathic sensitivity are hypothesized to contribute to excess interpersonal guilt in response to others' distress. This interpersonal guilt then increases the risk for internalizing problems, especially anhedonia/misery symptoms. Interindividual moderators, such as maladaptive parenting or chronic exposure to parents' negative affect, further interact with these genetic liabilities to amplify risk for personal distress and interpersonal guilt as well as for consequent internalizing problems. Age-related increases in the heritability of depression, anxiety, and empathy-related constructs are consistent with developmental shifts toward greater influence of intraindividual moderators throughout childhood and adolescence, with interindividual moderators exerting their greatest influence during early childhood. Efforts to modulate neurobiological and behavioral expressions of genetic dysregulation liabilities and to promote adaptive empathic skills must thus begin early in development.