904 research outputs found
The effect of zinc deficiency on deoxyribonucleic acid synthesis in rat liver
The effect of a short-term (3-day) dietary zinc deficiency on DNA synthesis in regenerating rat liver was investigated, with particular attention being paid to the timing of the S-phase of synthesis. The findings indicated a significantly reduced (P<0,01) incorporation of 'H-thymidine into the DNA of animals receiving the zinc-deficient ration (0,3 µg/g) when compared with control animals which received 60 µg/g in their diet. Of special interest was the finding that a shift occurred in the timing of the peak of maximum incorporation, from 17½ hours postoperatively in the control animals to 25 hours postoperatively in the deficient animals. Thus, when comparisons were made between the incorporation data at the respective peaks of maximum DNA synthesis, the effect of zinc deficiency was considerably reduced (P<0,05), but not eliminated when compared with the data obtained at the same time postoperatively in both groups. The data highlight the need for studies concerning the effect of zinc deficiency on the incorporation of 'Hthymidine to be performed at the peak of maximum DNA synthesis for the respective treatments, and not, as is done at present, at the same time for all groups.S. Afr. Med. J., 48, 1697 (1974)
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Expression stability of commonly used reference genes in canine articular connective tissues
Background: The quantification of gene expression in tissue samples requires the use of reference
genes to normalise transcript numbers between different samples. Reference gene stability may
vary between different tissues, and between the same tissue in different disease states. We
evaluated the stability of 9 reference genes commonly used in human gene expression studies. Realtime
reverse transcription PCR and a mathematical algorithm were used to establish which
reference genes were most stably expressed in normal and diseased canine articular tissues and
two canine cell lines stimulated with lipolysaccaride (LPS).
Results: The optimal reference genes for comparing gene expression data between normal and
diseased infrapatella fat pad were RPL13A and YWHAZ (M = 0.56). The ideal reference genes for
comparing normal and osteoarthritic (OA) cartilage were RPL13A and SDHA (M = 0.57). The best
reference genes for comparing normal and ruptured canine cranial cruciate ligament were B2M and
TBP (M = 0.59). The best reference genes for normalising gene expression data from normal and
LPS stimulated cell lines were SDHA and YWHAZ (K6) or SDHA and HMBS (DH82), which had
expression stability (M) values of 0.05 (K6) and 0.07 (DH82) respectively. The number of reference
genes required to reduce pairwise variation (V) to <0.20 was 4 for cell lines, 5 for cartilage, 7 for
cranial cruciate ligament and 8 for fat tissue. Reference gene stability was not related to the level
of gene expression.
Conclusion: The reference genes demonstrating the most stable expression within each different
canine articular tissue were identified, but no single reference gene was identified as having stable
expression in all different tissue types. This study underlines the necessity to select reference genes
on the basis of tissue and disease specific expression profile evaluation and highlights the
requirement for the identification of new reference genes with greater expression stability for use
in canine articular tissue gene expression studies
The effect of a home-based, gamified stability skills intervention on 4-5-year-old children's physical and cognitive outcomes:A pilot study
Background: Stability skills (e.g., static/dynamic balance) are a precursor for other movement skill development (e.g., jumping, catching). However, young children consistently demonstrate low stability and movement skill ability. There is therefore a need to develop effective strategies to improve stability skills in early childhood. Aim: To pilot the effect of a home-based gamified stability skills intervention on 4-5-year-old children's physical skills, self-perceptions and cognitions. Methods: One-hundred-and-eleven 4-5-year-old children participated from three schools. Two schools were allocated into the intervention group (n = 66 children, 33 boys) and one to the control group (n = 45 children, 25 boys). Stability, fundamental movement skills, perceived motor competence, and cognition were assessed at baseline and at post-intervention. The intervention group was given a booklet detailing the 12-week gamified stability skill intervention. The control group participated in their usual weekly activities. Results: A series of ANCOVAs controlling for baseline values demonstrated significantly higher stability skills (F(1,93) = 24.79, p < 0.001, partial η2 = 0.212), fundamental movement skills (F(1,94) = 15.5, p = < 0.001, partial η2 = 0.139), perceived motor competence (F(1,96) = 5.48, p = 0.021, partial η2 = 0.054) and cognition (F(1,96) = 15.5, p = < 0.001, partial η2 = 0.139) at post-test for the intervention versus control groups. Discussion: This study demonstrates that a home-based, gamified, stability skills intervention enhances stability skills, fundamental movement skills, perceived motor competence and cognition in children aged 4-5-years old.</p
Standard Model stability bounds for new physics within LHC reach
We analyse the stability lower bounds on the Standard Model Higgs mass by
carefully controlling the scale independence of the effective potential. We
include resummed leading and next-to-leading-log corrections, and physical pole
masses for the Higgs boson, M_H, and the top-quark, M_t. Particular attention
is devoted to the cases where the scale of new physics \Lambda is within LHC
reach, i.e. \Lambda\leq 10 TeV, which have been the object of recent
controversial results. We clarify the origin of discrepancies and confirm our
earlier results within the error of our previous estimate. In particular for
\Lambda=1 TeV we find that
M_H[GeV]>52+0.64(M_t[GeV]-175)-0.50\frac{\alpha_s(M_Z)-0.118}{0.006}.
For fixed values of M_t and \alpha_s(M_Z), the error from higher effects, as
the lack of exact scale invariance of the effective potential and higher-order
radiative corrections, is conservatively estimated to be \simlt 5 GeV.Comment: 17 pages, latex + psfig.sty, 4 figure
The effect of adolescent inhalant abuse on energy balance and growth
The abuse of volatile solvents such as toluene is a significant public health concern, predominantly affecting adolescents. To date, inhalant abuse research has primarily focused on the central nervous system; however, inhalants also exert effects on other organ systems and processes, including metabolic function and energy balance. Adolescent inhalant abuse is characterized by a negative energy balance phenotype, with the peak period of abuse overlapping with the adolescent growth spurt. There are multiple components within the central and peripheral regulation of energy balance that may be affected by adolescent inhalant abuse, such as impaired metabolic signaling, decreased food intake, altered dietary preferences, disrupted glucose tolerance and insulin release, reduced adiposity and skeletal density, and adrenal hypertrophy. These effects may persist into abstinence and adulthood, and the long-term consequences of inhalant-induced metabolic dysfunction are currently unknown. The signs and symptoms resulting from chronic adolescent inhalant abuse may result in a propensity for the development of adult-onset metabolic disorders such as type 2 diabetes, however, further research investigating the long-term effects of inhalant abuse upon energy balance and metabolism are needed. This review addresses several aspects of the short- and long-term effects of inhalant abuse relating to energy and metabolic processes, including energy balance, intake and expenditure; dietary preferences and glycemic control; and the dysfunction of metabolic homeostasis through altered adipose tissue, bone, and hypothalamic-pituitary-adrenal axis function.Rose Crossin, Ashleigh Qama, Zane B. Andrews, Andrew J. Lawrence, Jhodie R. Dunca
Probing the Nature of Short Swift Bursts via Deep INTEGRAL Monitoring of GRB 050925
We present results from Swift, XMM-Newton, and deep INTEGRAL monitoring in
the region of GRB 050925. This short Swift burst is a candidate for a newly
discovered soft gamma-ray repeater (SGR) with the following observational burst
properties: 1) galactic plane (b=-0.1 deg) localization, 2) 150 msec duration,
and 3) a blackbody rather than a simple power-law spectral shape (with a
significance level of 97%). We found two possible X-ray counterparts of GRB
050925 by comparing the X-ray images from Swift XRT and XMM-Newton. Both X-ray
sources show the transient behavior with a power-law decay index shallower than
-1. We found no hard X-ray emission nor any additional burst from the location
of GRB 050925 in ~5 Ms of INTEGRAL data. We discuss about the three BATSE short
bursts which might be associated with GRB 050925, based on their location and
the duration. Assuming GRB 050925 is associated with the H II regions (W 58) at
the galactic longitude of l=70 deg, we also discuss the source frame properties
of GRB 050925.Comment: 13 pages, 13 figures, accepted for publication in ASR special issue
on Neutron Stars and Gamma Ray Bursts, full resolution of Fig 5 is available
at
http://asd.gsfc.nasa.gov/Takanori.Sakamoto/GRB050925/integral_ibis_images.ep
The Kinematic and Kinetic Development of Sprinting and Countermovement Jump Performance in Boys
Background: The aim of the study was to examine the kinematics and kinetics of sprint running and countermovement jump performance between the ages of 8 to 9, and 11 to 12 year old boys in order to understand the developmental plateau in performance. Methods: 18 physically active boys (Age: 10.1±1.6), in an under 9 years old (U9) and an under 12 years old (U12) group performed 15 m sprints and countermovement jumps. A 3D motion analysis system (200 Hz), synchronized with four force platforms (1000Hz), was used to collect kinematic and kinetic data during the first stance phase of the sprint run and the countermovement jump. Results: The U12 group had a significantly greater height (U9: 1.364±0.064 m; U12: 1.548±0.046 mm), larger mass (U9: 30.9±3.5 kg; U12: 43.9±5.0 kg), superior sprint performance over 0-5 m (U9: 1.31±0.007 seconds; U12: 1.23±0.009 seconds) and 0-15 m (U9: 3.20±0.17 seconds; U12: 3.01±0.20 seconds), and increased jump height (U9: 0.17±0.06 m; U12: 0.24±0.10 m) than the under 9 group. During the first stance phase of the sprint the U12 group had a significantly greater vertical (U9: 0.22±0.02 BW/s; U12: 0.25±0.03 BW.s) and horizontal impulse (U9: 0.07±0.02 BW/s; U12: 0.09±0.03 BW.s) during than the U9 group. When performing a countermovement jump the U12 group had a significantly greater mean average eccentric force (U9: 407.3±55.0 N; U12: 542.2±65.1 N) and mean average concentric force (U9: 495.8±41.3 N; U12: 684.0±62.1 N). Joint kinematics for the countermovement jump were significantly different between age groups for the ankle range of motion (U9: 80.6±17.4 º; U12: 64.1±9 º) and knee minimum joint angle (U9: -5.7±3.9 º; U12: 0.0±4.4 º). Conclusion: The study demonstrates for the first time that the development of physically active boys between the ages of 8-9 to 11-12 years increased the ground reaction forces and impulses during sprint running and countermovement jumps, but that sprint running technique had not developed during this period. Furthermore, countermovement jump technique was still emerging at the age of 8-9 years old. Practitioners need to implement on-going fine-grained sprint running and CMJ technique sessions to ensure that the increased force producing capabilities that come with age are appropriately utilized
Interaction of desulfovibrio desulfuricans biofilms with stainless steel surface and its impact on bacterial metabolism
Aims: To study the influence of some metallic elements of stainless steel 304 (SS 304) on the development and activity of a sulfate-reducing bacterial biofilm, using as comparison a reference nonmetallic material polymethylmethacrylate (PMMA).
Methods and Results: Desulfovibrio desulfuricans biofilms were developed on SS
304 and on a reference nonmetallic material, PMMA, in a flow cell system.
Steady-state biofilms were metabolically more active on SS 304 than on PMMA. Activity tests with bacteria from both biofilms at steady state also showed that the doubling time was lower for bacteria from SS 304 biofilms.
The influence of chromium and nickel, elements of SS 304 composition, was
also tested on a cellular suspension of Des. desulfuricans. Nickel decreased the bacterial doubling time, while chromium had no significant effect.
Conclusions: The following mechanism is hypothesized: a Des. desulfuricans
biofilm grown on a SS 304 surface in anaerobic conditions leads to the weakening
of the metal passive layer and to the dissolution in the bulk phase of nickel ions that have a positive influence on the sulfate-reducing bacteria metabolism.
This phenomenon may enhance the biocorrosion process.
Significance and Impact of the Study: A better understanding of the interactions between metallic surfaces such as stainless steel and bacteria commonly implied in the corrosion phenomena which is primordial to fight biocorrosion.Programme Praxis XXI; University of Santiago de
Compostela
Hospital to Home Transition for Patients With Stroke Under Bundled Payments
Bundled payments are a promising alternative payment model for reducing costs and improving the coordination of postacute stroke care, yet there is limited evidence supporting the effectiveness of bundled payments for stroke. This may be due to the lack of effective strategies to address the complex needs of stroke survivors. In this article, we describe COMprehensive Post-Acute Stroke Services (COMPASS), a comprehensive transitional care intervention focused on discharge from the acute care setting to home. COMPASS may serve as a potential care redesign strategy under bundled payments for stroke, such as the Centers for Medicare & Medicaid Innovation Bundled Payment for Care Improvement Initiative. The COMPASS care model is aligned with the incentive structures and essential components of bundled payments in terms of care coordination, patient assessment, patient and family involvement, and continuity of care. Ongoing evaluation will inform the design of incorporating COMPASS-like transitional care interventions into a stroke bundle
The Cost of Implementing and Sustaining the COMprehensive Post-Acute Stroke Services Model
Background:The COMprehensive Post-Acute Stroke Services (COMPASS) model, a transitional care intervention for stroke patients discharged home, was tested against status quo postacute stroke care in a cluster-randomized trial in 40 hospitals in North Carolina. This study examined the hospital-level costs associated with implementing and sustaining COMPASS.Methods:Using an activity-based costing survey, we estimated hospital-level resource costs spent on COMPASS-related activities during approximately 1 year. We identified hospitals that were actively engaged in COMPASS during the year before the survey and collected resource cost estimates from 22 hospitals. We used median wage data from the Bureau of Labor Statistics and COMPASS enrollment data to estimate the hospital-level costs per COMPASS enrollee.Results:Between November 2017 and March 2019, 1582 patients received the COMPASS intervention across the 22 hospitals included in this analysis. Average annual hospital-level COMPASS costs were 735; 75th percentile: $3,475). Having 10% higher stroke patient volume was associated with 5.1% lower COMPASS costs per patient (P=0.016). About half (N=10) of hospitals reported postacute clinic visits as their highest-cost activity, while a third (N=7) reported case ascertainment (ie, identifying eligible patients) as their highest-cost activity.Conclusions:We found that the costs of implementing COMPASS varied across hospitals. On average, hospitals with higher stroke volume and higher enrollment reported lower costs per patient. Based on average costs of COMPASS and readmissions for stroke patients, COMPASS could lower net costs if the model is able to prevent about 6 readmissions per year
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