Molecular epidemiology of clonal diploids: a quick overview and a short DIY (do it yourself) notice.

In this short review we report the basic notions needed for understanding the population genetics of clonal diploids. We focus on the consequences of clonality on the distribution of genetic diversity within individuals, between individuals and between populations. We then summarise how to detect clonality in mainly sexual populations, conversely, how to detect sexuality in mainly clonal populations and also how genetic differentiation between populations is affected by clonality in diploids. This information is then used for building recipes on how to analyse and interpret genetic polymorphism data in molecular epidemiology studies of clonal diploids.

Medical residents' feedback on needs and acquired skills following a short course on cross-cultural competence

Objectives The purpose of this study is to assess short and long term changes in knowledge, attitudes, and skills among medical residents following a short course on cultural competency and to explore their perspectives on the experience. Methods Eighteen medical residents went through a short training programme comprised of two seminars lasting 30' and 60' respectively over two days. Three months later, we conducted three focus groups, with 17 residents to explore their thoughts, perspectives and feedback about the course. To measure changes over time, we carried out a quantitative sequential survey before the seminars, three days after, and three months later using the Multicultural Assessment Questionnaire. Results Residents expressed a wide variety of perspectives on the main themes related to the content of the training - culture, trialogue, stereotypes, status, epidemiology, history and geopolitics - and related to its organization - relevance, volume, timing, target audience, training tools, and working material. Using the MAQ, we observed a higher global performance score (n=16) at three days (median=38) compared to results before the training (median=33) revealing a median difference of 5.5 points (z=2.4, p=0.015). This difference was still present at three months (∆=4.5, z=2.4, p=0.018), mainly due to knowledge acquisition (∆=3) rather than attitudes (∆=0) or skills (∆=1). Conclusions Cross-cultural competence training not only brings awareness of multicultural issues but also helps participants understand their own cultures, perception of others and preconceived ideas. Physicians' education should however also focus on improving implementation of acquired knowledge in cross-cultural competence.

Three short perioperative infusions of n-3 PUFAs reduce systemic inflammation induced by cardiopulmonary bypass surgery: a randomized controlled trial.

BACKGROUND: Fish oil (FO) has antiinflammatory effects, which might reduce systemic inflammation induced by a cardiopulmonary bypass (CPB). OBJECTIVE: We tested whether perioperative infusions of FO modify the cell membrane composition, inflammatory responses, and clinical course of patients undergoing elective coronary artery bypass surgery. DESIGN: A prospective randomized controlled trial was conducted in cardiac surgery patients who received 3 infusions of 0.2 g/kg FO emulsion or saline (control) 12 and 2 h before and immediately after surgery. Blood samples (7 time points) and an atrial biopsy (during surgery) were obtained to assess the membrane incorporation of PUFAs. Hemodynamic data, catecholamine requirements, and core temperatures were recorded at 10-min intervals; blood triglycerides, nonesterified fatty acids, glucose, lactate, inflammatory cytokines, and carboxyhemoglobin concentrations were measured at selected time points. RESULTS: Twenty-eight patients, with a mean ± SD age of 65.5 ± 9.9 y, were enrolled with no baseline differences between groups. Significant increases in platelet EPA (+0.86%; P = 0.0001) and DHA (+0.87%; P = 0.019) were observed after FO consumption compared with at baseline. Atrial tissue EPA concentrations were higher after FO than after control treatments (+0.5%; P < 0.0001). FO did not significantly alter core temperature but decreased the postoperative rise in IL-6 (P = 0.018). Plasma triglycerides increased transiently after each FO infusion. Plasma concentrations of glucose, lactate, and blood carboxyhemoglobin were lower in the FO than in the control group on the day after surgery. Arrhythmia incidence was low with no significant difference between groups. No adverse effect of FO was detected. CONCLUSIONS: Perioperative FO infusions significantly increased PUFA concentrations in platelet and atrial tissue membranes within 12 h of the first FO administration and decreased biological and clinical signs of inflammation. These results suggest that perioperative FO may be beneficial in elective cardiac surgery with CPB. This trial was registered at clinicaltrials.gov as NCT00516178.

Short term behavioural consequences of denied access to environmental facilities in milk

Selostus: Eräiden ympäristövirikkeiden saatavuuden estämisen välittömät vaikutukset tarhaminkin käyttäytymiseen

Hyponatremia and short-term outcomes in patients with acute pulmonary embolism

BACKGROUND: Hyponatremia, a marker of neurohormonal activation, is associated with poor outcomes in acute cardiorespiratory diseases such as myocardial infarction, right and left ventricular heart failure, and pneumonia. The prognostic value of hyponatremia in patients with acute pulmonary embolism (PE) is unknown. We sought to assess whether hyponatremia at presentation was associated with mortality and hospital readmission in patients hospitalized with PE. METHODS: We studied patient discharges with a primary diagnosis of PE from 185 acute care hospitals in Pennsylvania (1/2000-11/2002). We defined hyponatremia as a serum sodium level ≤135 mmol/l, measured at the time of patient presentation. The study outcomes were 30-day all-cause mortality and hospital readmission. We used random-intercept logistic regression to examine the association between hyponatremia and mortality. We adjusted for baseline patient (race, insurance, severity of illness using the Pulmonary Embolism Severity Index) and hospital characteristics (region, hospital size and teaching status). We used the same approach to examine the association between hyponatremia and readmission among patients who were discharged alive. RESULTS: Among 13,728 patient discharges with PE, 2907 (21.1%) had hyponatremia at the time of presentation. Patients with hyponatremia were older (P<0.001) and more likely to have a history of cancer (P<0.001), heart failure (P<0.001), or chronic lung disease (P=0.002) than patients without hyponatremia. Patients with hyponatremia had a higher unadjusted cumulative 30-day mortality (15.2% vs 8.0%;P<0.001) and readmission rate (15.9% vs 11.8%; P< 0.001) than patients without hyponatremia (Figure). After adjustment for race, insurance, severity of illness, and hospital factors, hyponatremia was associated with a significantly greater odds of death (OR 1.71, 95% CI: 1.50-1.95) and hospital readmission (OR 1.29, 95% CI: 1.14-1.46). CONCLUSIONS: In this large, statewide sample of unselected patients with acute PE, hyponatremia was relatively common and was an independent predictor of short-term mortality and hospital readmission. Given that sodium is a low-cost, easily available laboratory parameter, it may be potentially useful in risk-stratifying patients with PE.

In vivo measurement of glycine with short echo-time 1H MRS in human brain at 7 T.

OBJECT: To determine whether glycine can be measured at 7 T in human brain with (1)H magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: The glycine singlet is overlapped by the larger signal of myo-inositol. Density matrix simulations were performed to determine the TE at which the myo-inositol signal was reduced the most, following a single spin-echo excitation. (1)H MRS was performed on an actively shielded 7 T scanner, in five healthy volunteers. RESULTS: At the TE of 30 ms, the myo-inositol signal intensity was substantially reduced. Quantification using LCModel yielded a glycine-to-creatine ratio of 0.14 +/- 0.01, with a Cramer-Rao lower bound (CRLB) of 7 +/- 1%. Furthermore, quantification of metabolites other than glycine was possible as well, with a CRLB mostly below 10%. CONCLUSION: It is possible to detect glycine at 7 T in human brain, at the short TE of 30 ms with a single spin-echo excitation scheme.

Influence of scatter reduction method and monochromatic beams on image quality and dose in mammography.

In mammography, the image contrast and dose delivered to the patient are determined by the x-ray spectrum and the scatter to primary ratio S/P. Thus the quality of the mammographic procedure is highly dependent on the choice of anode and filter material and on the method used to reduce the amount of scattered radiation reaching the detector. Synchrotron radiation is a useful tool to study the effect of beam energy on the optimization of the mammographic process because it delivers a high flux of monochromatic photons. Moreover, because the beam is naturally flat collimated in one direction, a slot can be used instead of a grid for scatter reduction. We have measured the ratio S/P and the transmission factors for grids and slots for monoenergetic synchrotron radiation. In this way the effect of beam energy and scatter rejection method were separated, and their respective importance for image quality and dose analyzed. Our results show that conventional mammographic spectra are not far from optimum and that the use of a slot instead of a grid has an important effect on the optimization of the mammographic process. We propose a simple numerical model to quantify this effect.

Investigation of Two Bridge Alternatives for Low Volume Roads, Volume 1 of 2 Concept 1: Precast Steel Beam Units, HR-382, 1997

Recent reports have indicated that 23.5% of the nation's highway bridges are structurally deficient and 17.7% are functionally obsolete. A significant number of these bridges are on the Iowa secondary road system where over 86% of the rural bridge management responsibilities are assigned to the counties. Some of the bridges can be strengthened or otherwise rehabilitated, but many more are in need of immediate replacement. In a recent investigation (HR-365 "Evaluation of Bridge Replacement Alternatives for the County Bridge System") several types of replacement bridges that are currently being used on low volume roads were identified. It was also determined that a large number of counties (69%) have the ability and are interested in utilizing their own forces to design and construct short span bridges. In reviewing the results from HR-365, the research team developed one "new" bridge replacement concept and a modification of a replacement system currently being used. Both of these bridge replacement alternatives were investigated in this study, the results of which are presented in two volumes. This volume (Volume 1) presents the results of Concept 1 - Steel Beam Precast Units. Concept 2 - Modification of the Beam-in-Slab Bridge is presented in Volume 2. Concept 1, involves the fabrication of precast units (two steel beams connected by a concrete slab) by county work forces. Deck thickness is limited so that the units can be fabricated at one site and then transported to the bridge site where they are connected and the remaining portion of the deck placed. Since Concept 1 bridge is primarily intended for use on low-volume roads, the precast units can be constructed with new or used beams. In the experimental part of the investigation, there were three types of static load tests: small scale connector tests, "handling strength" tests, and service and overload tests of a model bridge. Three finite element models for analyzing the bridge in various states of construction were also developed. Small scale connector tests were completed to determine the best method of connecting the precast double-T (PCDT) units. "Handling strength" tests on an individual PCDT unit were performed to determine the strength and behavior of the precast unit in this configuration. The majority of the testing was completed on the model bridge [L=9,750 mm (32 ft), W=6,400 mm (21 ft)] which was fabricated using the precast units developed. Some of the variables investigated in the model bridge tests were number of connectors required to connect adjacent precast units, contribution of diaphragms to load distribution, influence of position of diaphragms on bridge strength and load distribution, and effect of cast-in-place portion of deck on load distribution. In addition to the service load tests, the bridge was also subjected to overload conditions. Using the finite element models developed, one can predict the behavior and strength of bridges similar to the laboratory model as well as design them. Concept 1 has successfully passed all laboratory testing; the next step is to field test it.

Hypofractionated radiotherapy in the treatment of diffuse intrinsic pontine glioma in children: a single institution's experience

Objective: To demonstrate our institutional experience in the treatment ofdiffuse intrinsic pontine glioma (DIPG) with an hypofractionated external beam radiotherapy schedule.Materials and Methods: Between April 1996 and January 2004, 22 patients, ages 2.9-12.5 years, with newly diagnosed DIPG were treated by hypofractionated radiation therapy delivering a total dose of 45 Gy in daily fraction of 3 Gy, given over 3 weeks. No other treatment was applied concomittently.Results: Fourteen of the 22 patients received the prescribed dose of 45 Gy in 15 fractions of 3 Gy, two patients received a total dose of 60 and 45 Gy with a combination of two different beams (photons and neutrons), in 5 cases the daily fraction was modified to 2 Gy because of bad tolerance and one patient died due to serious intracranial hypertension after 2 fractions of 3 Gy and one of 2 Gy. Fourteen patients of 22 patients/of the total showed a clinical improvement, usually starting in the second week of treatment. No grade 3 or 4 acute toxicity from radiotherapy was observed. No treatment interruption was needed. In six patients, steroids could be discontinued within one month after the end of radiotherapy. The median time to progression and the median overall survival were 5.7 months and 7.6 months, respectively.Conclusion: External radiotherapy with a radical hypofractionated regimen is feasible and well tolerated in children with newly diagnosed DIPG. This regimen does not seem however to change the overall survival in this setting. It could represent an alternative option of short duration to more protracted regimens.

Coffee consumption attenuates short-term fructose-induced liver insulin resistance in healthy men.

BACKGROUND: Epidemiologic and experimental data have suggested that chlorogenic acid, which is a polyphenol contained in green coffee beans, prevents diet-induced hepatic steatosis and insulin resistance. OBJECTIVE: We assessed whether the consumption of chlorogenic acid-rich coffee attenuates the effects of short-term fructose overfeeding, dietary conditions known to increase intrahepatocellular lipids (IHCLs), and blood triglyceride concentrations and to decrease hepatic insulin sensitivity in healthy humans. DESIGN: Effects of 3 different coffees were assessed in 10 healthy volunteers in a randomized, controlled, crossover trial. IHCLs, hepatic glucose production (HGP) (by 6,6-d2 glucose dilution), and fasting lipid oxidation were measured after 14 d of consumption of caffeinated coffee high in chlorogenic acid (C-HCA), decaffeinated coffee high in chlorogenic acid, or decaffeinated coffee with regular amounts of chlorogenic acid (D-RCA); during the last 6 d of the study, the weight-maintenance diet of subjects was supplemented with 4 g fructose · kg(-1) · d(-1) (total energy intake ± SD: 143 ± 1% of weight-maintenance requirements). All participants were also studied without coffee supplementation, either with 4 g fructose · kg(-1) · d(-1) (high fructose only) or without high fructose (control). RESULTS: Compared with the control diet, the high-fructose diet significantly increased IHCLs by 102 ± 36% and HGP by 16 ± 3% and decreased fasting lipid oxidation by 100 ± 29% (all P < 0.05). All 3 coffees significantly decreased HGP. Fasting lipid oxidation increased with C-HCA and D-RCA (P < 0.05). None of the 3 coffees significantly altered IHCLs. CONCLUSIONS: Coffee consumption attenuates hepatic insulin resistance but not the increase of IHCLs induced by fructose overfeeding. This effect does not appear to be mediated by differences in the caffeine or chlorogenic acid content. This trial was registered at clinicaltrials.gov as NCT00827450.

Lag-one autocorrelation in short series: Estimation and hypothesis testing

In the first part of the study, nine estimators of the first-order autoregressive parameter are reviewed and a new estimator is proposed. The relationships and discrepancies between the estimators are discussed in order to achieve a clear differentiation. In the second part of the study, the precision in the estimation of autocorrelation is studied. The performance of the ten lag-one autocorrelation estimators is compared in terms of Mean Square Error (combining bias and variance) using data series generated by Monte Carlo simulation. The results show that there is not a single optimal estimator for all conditions, suggesting that the estimator ought to be chosen according to sample size and to the information available of the possible direction of the serial dependence. Additionally, the probability of labelling an actually existing autocorrelation as statistically significant is explored using Monte Carlo sampling. The power estimates obtained are quite similar among the tests associated with the different estimators. These estimates evidence the small probability of detecting autocorrelation in series with less than 20 measurement times.

Metric Short Course for the Office of Bridges and Structures, HR-378, 1995

This metric short course was developed in response to a request from the Office of Bridges and Structures to assist in the training of engineers in the use of metric units of measure which will be required in all highway designs and construction after September 30, 1996 (CFR Presidential Executive Order No. 12770). The course notes which are contained in this report, were developed for a half-day course. The course contains a brief review of metrication in the U.S., metric units, prefixes, symbols, basic conversions, etc. The unique part of the course is that it presents several typical bridge calculations (such as capacity of reinforced concrete compression members, strength of pile caps, etc.) worked two ways: inch-pound units throughout with end conversion to metric and initial hard conversion to metric with metric units throughout. Comparisons of partial results and final results (obtained by working the problems the two ways) are made for each of the example problems.

Investigation of the Loss of Prestress in Prestressed Concrete Beams due to Steam Curing, HR-62, 1961

Mass production of prestressed concrete beams is facilitated by the accelerated curing of the concrete. The ·method most commonly used for this purpose is steam curing at atmospheric pressure. This requires concrete temperatures as high as 150°F. during the curing period. Prestressing facilities in Iowa are located out of doors. This means that during the winter season the forms are set and the steel cables are stressed at temperatures as low as 0°F. The thermal expansion of the prestressing cables should result in a reduction of the stress which was placed in them at the lower temperature. If the stress is reduced in the cables, then the amount of prestress ultimately transferred to the concrete may be less than the amount for which the beam was designed. Research project HR-62 was undertaken to measure and explain the difference between the initial stress placed in the cables and the actual stress which is eventually transferred to the concrete. The project was assigned to the Materials Department Laboratory under the general supervision of the Testing Engineer, Mr. James W. Johnson. A small stress bed complete with steam curing facilities was set up in the laboratory, and prestressed concrete beams were fabricated under closely controlled conditions. Measurements were made to determine the initial stress in the steel and the final stress in the concrete. The results of these tests indicate that there is a general loss of prestressing force in excess of that caused by elastic shortening of the concrete. The exact amount of the loss and the identification of the factors involved could not be determined from this limited investigation.