The GH/IGF-I Axis and Cognitive Changes across a 4-Year Period in Healthy Adults

After the age of 40, the amount of growth hormone in humans decreases. The reduced activity of the GH-IGF axis may play a role in age-related cognitive impairments. In the present study, mood and cognition of 30 healthy subjects (7 males, 23 females, aged 41–76 yr, mean age 60.9 ± 9.0) were examined twice. At baseline, we determined fasting blood levels of GH and IGF-I. Mood and cognitive status were assessed at baseline and after, on the average, 3 years and 9 months of followup. Working memory performance decreased over the years in the low IGF-group (P = .007), but not the high IGF-I group. Higher levels of GH were related with a better working memory at the second test (r = 0.42, P = .01) while higher levels of IGF-I tended to be related with a better working memory (r = 0.3, P = .06). The results suggest that higher serum levels of GH and IGF-I preserve the quality of working memory functions over the years

Discrete charging of metallic grains: Statistics of addition spectra

We analyze the statistics of electrostatic energies (and their differences) for a quantum dot system composed of a finite number $K$ of electron islands (metallic grains) with random capacitance-inductance matrix $C$, for which the total charge is discrete, $Q=Ne$ (where $e$ is the charge of an electron and $N$ is an integer). The analysis is based on a generalized charging model, where the electrons are distributed among the grains such that the electrostatic energy E(N) is minimal. Its second difference (inverse compressibility) $\chi_{N}=E(N+1)-2 E(N)+E(N-1)$ represents the spacing between adjacent Coulomb blockade peaks appearing when the conductance of the quantum dot is plotted against gate voltage. The statistics of this quantity has been the focus of experimental and theoretical investigations during the last two decades. We provide an algorithm for calculating the distribution function corresponding to $\chi_{N}$ and show that this function is piecewise polynomial.Comment: 21 pages, no figures, mathematical nomenclature (except for Abstract and Introduction

Differential effect sizes of growth hormone replacement on quality of life, well-being and health status in growth hormone deficient patients: a meta-analysis

BACKGROUND: Patients with growth hormone deficiency (GHD) frequently report to suffer from an impaired Quality of Life (QoL) and growth hormone (GH) substitution is found to improve this. However, the same test may be used for measuring QoL, well-being or health status in different studies. QoL has been defined as the subjective appraisal of one's current life based primarily on psychological function. The most important in the appraisal of well-being is mental function and concerning health status patients evaluate physical function as most important. To differentiate the effects of GH replacement on psychological variables in patients with GHD we carried out a number of meta-analyses, classifying questionnaires into instruments measuring QoL, psychological well-being and health status. METHODS: We searched the electronic databases PUBMED and PiCarta from 1985 to 2004. Studies were included that evaluated the effect of GH on patient-reported outcomes in adults with GHD (aged 18 years and above). According to generally accepted definitions we classified the questionnaires as instruments measuring QoL, well-being and health status. By means of meta-analyses the average effect size (d) for QoL, well-being and health status was calculated. RESULTS AND DISCUSSION: Based on open studies GH replacement is found to improve QoL with a small effect size (d = 0.18), well-being with a medium effect size (d = 0.47) and health status with a small effect size (d = 0.26). As the effect size of well-being is most pronounced the generally reported effects of GH replacement on QoL may be overestimated and actually reflect the effect on well-being. CONCLUSION: To get more insight in the specific psychological effects of GH treatment it is recommended that instruments selected for these studies should be more consistently classified as instruments measuring QoL, well-being or health status

A rolling-gliding wear simulator for the investigation of tribological material pairings for application in total knee arthroplasty

<p>Abstract</p> <p>Background</p> <p>Material wear testing is an important technique in the development and evaluation of materials for use in implant for total knee arthroplasty. Since a knee joint induces a complex rolling-gliding movement, standardised material wear testing devices such as Pin-on-Disc or Ring-on-Disc testers are suitable to only a limited extent because they generate pure gliding motion only.</p> <p>Methods</p> <p>A rolling-gliding wear simulator was thus designed, constructed and implemented, which simulates and reproduces the rolling-gliding movement and loading of the knee joint on specimens of simplified geometry. The technical concept was to run a base-plate, representing the tibia plateau, against a pivoted cylindrical counter-body, representing one femur condyle under an axial load. A rolling movement occurs as a result of the friction and pure gliding is induced by limiting the rotation of the cylindrical counter-body. The set up also enables simplified specimens handling and removal for gravimetrical wear measurements. Long-term wear tests and gravimetrical wear measurements were carried out on the well known material pairings: cobalt chrome-polyethylene, ceramic-polyethylene and ceramic-ceramic, over three million motion cycles to allow material comparisons to be made.</p> <p>Results</p> <p>The observed differences in wear rates between cobalt-chrome on polyethylene and ceramic on polyethylene pairings were similar to the differences of published data for existing material-pairings. Test results on ceramic-ceramic pairings of different frontal-plane geometry and surface roughness displayed low wear rates and no fracture failures.</p> <p>Conclusions</p> <p>The presented set up is able to simulate the rolling-gliding movement of the knee joint, is easy to use, and requires a minimum of user intervention or monitoring. It is suitable for long-term testing, and therefore a useful tool for the investigation of new and promising materials which are of interest for application in knee joint replacement implants.</p

Exercising heart failure patients:cardiac protection through preservation of mitochondrial function and substrate utilization?

Current heart failure (HF) therapy remains unable to substantially improve exercise capacity. Studies have shown that exercise training has beneficial effects on the heart in both health and disease. How mitochondria respond to exercise in this setting has, however, received less attention in literature. These beneficial effects may include protective changes in mitochondrial function and adaptations in substrate utilization. This review describes exercise-induced changes in cardiac metabolism, including changes in mitochondrial function and substrate utilization and their effects on cardiac function. We conclude that exercising HF patients can improve mitochondrial function and optimize substrate utilization, eventually improving or restoring cardiac function. This suggests that exercise itself should be incorporated in the HF treatment plan, to improve cardiac function and in term exercise capacity. Extending knowledge on mechanisms by which exercise exerts protective effects could potentially lead to development of therapies directed at improving mitochondrial function and substrate utilization in HF.</p

And the first shall be the last

This study analyzes the puzzle of Hungarian economic drifting in a long run perspective. The underlying puzzle for the investigation is why bad policies are invariably popular and good policies unpopular, thus why political and economic rationality never overlap. The first part of the article summarizes in eight points the basic features of the postwar period. Then six lessons are offered, which might be useful for other countries in transition or for students of comparative economics and politics, lessons that can be generalized on the basis of the individual country experience

Book review: Gerald D. Feldman, Austrian banks in the period of National Socialism

Even though Germany, Austria, and Hungary experienced a major financial crisis simultaneously in 1931, of the three, only Germany's and Austria's episodes have been investigated in depth. This article offers a thorough assessment of the missing piece. It finds that, just like Germany, Hungary also experienced a twin crisis. The primary reason for the weakness of the financial sector was banks’ excessive exposure to agricultural loans. The fragility of the currency was the result of an early balance-of-payments crisis in 1928/9. The vulnerability of the banking and monetary systems culminated in a twin crisis in 1931

Interpretability of Hungarian embedding spaces using a knowledge base

While word embeddings have proven to be highly useful in many NLP tasks, they are difficult to interpret for humans. Sparse word embeddings are reminiscent of knowledge bases containing words that are already characterized in sparse forms. In our work, we investigate to what extent sparse word representations convey knowledge about the words in knowledge bases. We utilize Hungarian sparse word embeddings and ConceptNet, a knowledge base that supports Hungarian