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In early 1998, three transfer ionization chambers were used to compare the air-kerma and absorbed-dose-to-water calibration factors measured by the National Research Council of Canada (NRCC) and the National Institute of Standards and Technology (NIST). The ratios between the NRCC and NIST calibration factors are 0.9950 and 1.0061 in the case of the absorbed-dose-to-water and air-kerma standards, respectively. In the case of the standard of absorbed dose to water, the combined uncertainty of the ratio between the standards of the two laboratories is about 0.6% and consequently, the observed difference of 0.5% is not significant at the one sigma level. In the case of the standard of air kerma, the combined uncertainty of the ratio between the standards of the two laboratories is about 0.4%, and so the observed difference of 0.61% is significant at the one sigma level. However, this discrepancy is due to the known differences in the methods of assessing the wall correction factor at the two laboratories. Taking into account changes implemented in the standards that form the basis of the calibrations, the present results are consistent with those of the previous comparison done in 1990/91. As a direct result of these differences in the calibration factors, changing from an air-kerma based protocol following TG-21 to an absorbed-dose-to-water based protocol following TG-51, would alter the relationship between clinical dosimetry in Canada and the United States by about 1%. For clinical reference dosimetry, the change from TG-21 to TG-51 could result in an increase of up to 2% depending upon the ion chamber used, the details of the protocol followed and the source of traceability, either NRCC or NIST.
In 1990, the National Research Council (NRC) published two in-depth assessments of marine environmental monitoring effectiveness. The first of these, Managing Troubled Waters: The Role of Marine Environmental Monitoring, provided a national perspective and the second, Monitoring Southern California's Coastal Waters, examined the specifics of monitoring design and implementation in a densely populated, highly urbanized coastal region. The reports include explicit recommendations about the need for greater regionalization of monitoring efforts, supported by greater standardization of field, laboratory, and data analysis methods. They also identified the need for centralized data management and for greater flexibility in the language of standard discharge permits, flexibility that would permit discharge agencies to more readily participate in regional monitoring and research programs. Other recommendations identified a need for EPA and NOAA to focus on creating a national monitoring program structured as a network of coordinated local and regional efforts. Finally, the NRC emphasized the need for better reporting and for periodic review of monitoring's relevance to management concerns. In this paper, we use southern California as a test case to assess progress made in implementing the NRC's recommendations. We review progress made on each recommendation and discuss the features of the regulatory and management climate that contributed to or impeded this progress. We also consider whether, and to what extent, the NRC's recommendations remain relevant in the present context.
In Denmark the official dietary guidelines and food recommendations are expressed in the Five Dietary advices and the Danish food circle. Such guidelines are entirely different from recommendations on nutrient intakes, which are expressed in terms of exact values and established through a more formal procedure. Some of the most fundamental principles for food recommendations given to the public are that they are perceived as consistent and based on a firm consensus, and that their relevance and translation into practical action is obvious to the public. When the situation in Denmark is compared to these principles the main issue turns out to be neither lack of consistency in recommendations issued by government agencies and voluntary health organisations, nor is it lack of consensus among the experts about the fundamental messages of the guidelines. A more important problem is that the public does not distinguish between formal recommendations from authorized sources, and a variety of advices from other sources as well as non-formal comments from individual scientists. A cause of serious concern is the fact that the Danish public seems to lack a realistic picture of what the dietary guidelines imply in terms of foods. A number of contradictions is built into the process of communicating dietary recommendations effectively to the public. These can only be solved if the process is planned on a long-term basis.
The Italian National Research Council (CNR) has launched a special project aiming at gathering competences on rare diseases, their pathogenesis and their possible pharmacological management. The subproject on homocystinuria has three main objectives: to establish the prevalence and incidence of the disease in the Italian population, to develop sensitive assays of sulfated amino acids which allow discrimination of heterozygotes from normal subjects and to better define the complex interactions between homocystinuria and vascular complications.
In 1983 the Italian National Research Council funded a project specifically focused on Hospital infection control. The main objectives were to describe the epidemiological pattern of hospital-acquired infections; to evaluate different control measures and preventive strategies. The general frame and research issues of the project are discussed in this paper. The main research areas of the project were: urinary tract infections; infections in surgery; intensive care units/high risk patients; microbiological aspects; e) education programs.
This study was conducted to evaluate the accuracy of the National Research Council's (2000) Nutrient Requirements of Beef Cattle computer model when used to predict calf performance during on-farm pasture or dry-lot weaning and backgrounding. Calf performance was measured on 22 farms in 2002 and 8 farms in 2003 that participated in West Virginia Beef Quality Assurance Sale marketing pools. Calves were weaned on pasture (25 farms) or dry-lot (5 farms) and fed supplemental hay, haylage, ground shell corn, soybean hulls, or a commercial concentrate. Concentrates were fed at a rate of 0.0 to 1.5% of BW. The National Research Council (2000) model was used to predict ADG of each group of calves observed on each farm. The model error was measured by calculating residuals (the difference between predicted ADG minus observed ADG). Predicted animal performance was determined using level 1 of the model. Results show that, when using normal on-farm pasture sampling and forage analysis methods, the model error for ADG is high and did not accurately predict the performance of steers or heifers fed high-forage pasture-based diets; the predicted ADG was lower (P < 0.05) than the observed ADG. The estimated intake of low-producing animals was similar to the expected DMI, but for the greater-producing animals it was not. The NRC (2000) beef model may more accurately predict on-farm animal performance in pastured situations if feed analysis values reflect the energy value of the feed, account for selective grazing, and relate empty BW and shrunk BW to NDF.
In 1998, the United States National Research Council prepared a report assessing the viability of potable reuse. The report concludes that planned indirect potable reuse is a viable application of reclaimed water but should be considered for implementation only after other alternative measures, such as development of new water sources, nonpotable reuse, and water conservation, have been evaluated and determined not to be economically or technically feasible. Although health-effects research has not indicated that there have been any adverse health effects resulting from drinking highly treated reclaimed water, those data are sparse. There are uncertainties associated with assessing the potential health risks of drinking reclaimed water. The report acknowledges that several issues remain unresolved regarding reclaimed water treatment and reliability, microbial and chemical constituents of concern, and water quality and health effects monitoring. Research needs include methods to detect emerging pathogens, identification and quantification of trace organic compounds, development of suitable in vivo toxicological methods, and evaluation of the effectiveness and reliability of multiple treatment barriers. The report also concludes that direct potable reuse is not a viable option to consider at this time.
The author was the Chairman of a Task Group on the Biological Effects of Space Radiation formed as a result of discussions between NASA and the U.S. National Research Council's Committee on Space Biology and Medicine - a committee under the U.S. National Research Council's Space Studies Board. The Task Group was asked to review current knowledge on the effects of long-term exposure to radiation in space and to consider NASA radiation shielding requirements for orbital and interplanetary spacecraft. The group was charged with assessing the adequacy of NASA planning for the protection of humans from radiation in space and with making recommendations regarding needed research and/or new shielding requirements. This manuscript is a summary of the findings and recommendations of the Task Group. Beyond the protection of the Earth's atmosphere and its magnetosphere, the exposure to ionizing radiations far exceeds that on Earth. Of all the risks astronauts may face, this one is probably the most straightforward to control - by providing adequate shielding. However, because shielding adds weight, cost and complexity to space vehicles, it is important for designers to have a good quantitative understanding of the true risk and its degree of uncertainty so as not to under- or overshield spacecrafts. The extrapolations from our knowledge of ionizing radiation effects of low linear energy transfer (LET) to the risks from high-atomic-number high-energy energetic (HZE) cosmic rays are very uncertain because the necessary experiments on the effects of such particles have not been carried out and the extrapolation from low-LET to very high-LET has great uncertainties. These uncertainties were enumerated by the Task Group, and the types of experiments needed to minimize the uncertainties were described. The report found that, because of the small amounts of available time for biological research at HZE accelerators, it would take more than a decade of effort to obtain the answers to a narrow set of key questions that would facilitate reduction in risks and identification of the types of shielding needed.
The following is an excerpt from the Executive Summary of the National Research Council Report.
The Institute of Theory and Techniques of the Legal Information (ITTIG) of the Italian National Research Council (CNR) has produced various electronic information systems. Among these, the archive BIG (Bibliography on right to life and interruption of pregnancy, bioethics and genetic engineering). The article presents the archive BIG in its previous version in print and Internet versions, and it describes its main characteristics (original, analytical, objective, scientific). At last, it exposes the rules for data selection and the debate about the right to life in Italy. The archive BIG enables the expert as well as the layman, to exercise an effective control on the enormous material published on this matter.
The authors present a 16-year update on schizophrenia in the National Academy of Sciences-National Research Council (NAS-NRC) Twin Registry. As of October 1981, a recorded diagnosis of schizophrenia was equally common in monozygotic and dizygotic twins. However, probandwise concordance for schizophrenia was significantly greater in monozygotic (30.9%) than in dizygotic (6.5%) twins. Biases in zygosity determination, diagnosis, or ascertainment could not plausibly explain these results. Correction for selection effects in construction of the registry produced concordance rates for schizophrenia approaching those found in previous studies. According to registry data, genetic factors appear at least as important in the etiology of schizophrenia as in several common medical conditions, including diabetes and hypertension. Results from the NAS-NRC Twin Registry support the etiologic importance of genetic factors in schizophrenia.
This experiment evaluated the effects of prepubertal energy intake and dietary protein source on average daily gain of Holstein heifers. Holstein heifers (n = 273) were assigned to one of three dietary energy treatments that were designed to achieve average daily gains of 0.6, 0.8, and 1.0 kg/d from 90 to 320 kg of body weight. Within each energy treatment, heifers were assigned to diets that were supplemented with animal and plant proteins or plant protein and urea. Diets were formulated using the Cornell Net Carbohydrate and Protein System. Actual mean daily gains by heifers on each energy treatment were 0.68, 0.83, and 0.94 kg/d and were not affected by protein source. Undegradable intake protein was predicted by the Cornell Net Carbohydrate and Protein System to be adequate to support the observed daily gain that was allowed by the amount of energy in the diet and was 13 to 25% lower than the recommendations for undegradable intake protein by the National Research Council. These results suggested that requirements for undegradable intake protein may be met at concentrations that are less than 35% of the dietary crude protein. Energy equations from the National Research Council and Cornell Net Carbohydrate and Protein System were evaluated and accounted for 87 and 86% of the variation in body weight gain that was allowed by the amount of energy in the diet with biases of -7.7 and -5.7%, respectively. The Cornell Net Carbohydrate and Protein System has the primary advantage of improved accuracy in the prediction of nutrient requirements in each unique production situation.