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At least 451 records · Page 25Linked to original sources

Detection of 210Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room.

Radon gas was allowed to accumulate in its radium source and then injected into a 36 m(3) test room, resulting in an initial radon concentration of 15 kBq m(-3). Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10(2)-10(5) particles cm(-3) in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, (210)Po (T(1/2)=138 days). This isotope is separated from the short-lived progeny by (210)Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter (210)Po on the same filter papers measured in the year 2000 were studied. The results of the (210)Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and (210)Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker.

Aerosols↗

Quality of patient-reported outcome data captured using paper and interactive voice response diaries in an allergic rhinitis study: is electronic data capture really better?

BACKGROUND: Accuracy and reliability of diary data collected in allergic rhinitis trials depends on how and when the information is recorded by the subjects. OBJECTIVE: To compare diary data collected by using paper (optical mark readable) and electronic [telephone, interactive voice response system (IVRS)] tools. METHODS: There was a randomized, 3-week, 3-way, crossover trial, in 87 adults with allergic rhinitis recording diary data at home. Outcome measures were (1) comparison of symptom data during weeks when both or only 1 instrument was used; (2) missing data: and (3) ease of use and participant preference. RESULTS: More than 40,000 symptom data elements were recorded by 72 protocol-correct subjects. Symptoms recorded during the week that both instruments were used and when the 2 instruments were used alone were indistinguishable. Overall, 0.45% of paper and 4.12% of IVRS symptom data were missing. Of 10,080 paired data collected on paper and IVRS diaries during the week in which subjects used both, 94.44% were identical. Using IVRS, 63.2% of protocol-correct data were entered within the designated time and 87.6% within 1 half-day of the time specified; 85% of subjects preferred the paper instrument, 4% preferred IVRS, and 11% had no preference. CONCLUSIONS: A paper-based instrument can capture data indistinguishable from data captured from an electronic product. Processes to collect diary data should be evaluated for each study rather than simply to use the "latest" technology. Another interpretation is that frequency of recording diary data does not have a significant impact on outcomes.

Adult↗

Inter-test reliability of the anti-RESA indices based on ELISA tests using eluates from whole blood spots dried on filter paper.

The ring-infected erythrocyte surface antigen (RESA), is one of the falciparum malaria vaccine candidates rarely studied in Brazil. Fieldwork logistics to conduct serology studies is simplified when eluates from whole blood dried on filter paper can be used. Therefore, this study aimed to assess the inter-test reliability for the anti-RESA ELISA-based indices using eluates from filter paper and from serum samples. The study population consisted of 210 individuals (Brazil) from whom matched samples were collected. Anti-RESA ELISA-based index means (+/- S.D.) were 15.29% (+/-28.13%) for filter paper and 11.79% (+/-23.67%) for serum samples. The intra-class correlation coefficient was estimated to be 82.38%, indicating high test reliability. However, there was a significant tendency for filter paper test results to have higher values than serum sample test results (P < 0.001). Explanations for this finding may be the presence of haemoglobin in the eluates from filter paper, which may interfere with ELISA testing.

Adolescent↗

A comparison of an electronic version of the SF-36 General Health Questionnaire to the standard paper version.

Because of its sound psychometric properties the SF-36 General Health Questionnaire is used throughout the world, yet it is difficult to analyse and score. Using a newly developed software package, onto which any questionnaire can be loaded, we developed an electronic version of the SF-36 General Health Questionnaire. The purpose of this study is test the effect of the electronic mode of administration on the measurement properties of the SF-36. In a randomised cross-over design study 79 healthy individuals and 36 chronic pain patients completed both electronic and paper versions of the SF-36. Seventy-one percent preferred the electronic SF-36, 7% stated no preference, and 22% preferred the paper version. Completion time for the electronic SF-36 was slightly less, and there were no missing or problematical responses, whereas 44% of participants had at least one missing or problematical response in the paper version. Data entry and auditing time was 8 hours. There was less than 4% inter-version difference for any of the SF-36 sub-scales. The electronic SF-36 was well accepted and slightly quicker to complete than the paper version. We conclude that the electronic SF-36 is equivalent in performance and more effective than the paper version.

Chronic Disease↗

The drug diagnostic co-development concept paper: commentary from the 3rd FDA-DIA-PWG-PhRMA-BIO Pharmacogenomics Workshop.

At the Washington DC Pharmacogenomics in Drug Development and Regulatory Decision-Making: Workshop III - Three Years of Promise, Proposals and Progress on Optimizing the Benefit/Risk of Medicines (11-13 April 2005), one break-out session (Track 2) focused on co-development of therapeutic drug and diagnostic products. The Food and Drug Administration (FDA) released a draft concept paper shortly before the workshop was to convene. Track 2 was a forum for initial discussion of the content of the concept paper, and industry's initial reactions. After the workshop, formal commentaries on the co-development concept paper were submitted by several trade associations (e.g., Pharmaceutical Research and Manufacturers of America (PhRMA), Advanced Medical Technology Association (AdvaMed), American Association for Clinical Chemistry) and individual companies to FDA's Docket No. 2004N-0279. This paper includes a summary of the key features of the draft concept paper, the discussion in Track 2 of the April, 2005 meeting and highlights of the industry comments submitted to the FDA docket following the meeting.

Clinical Trials as Topic↗

Assessing validity in written tests of general practice - exploration by factor analysis of candidate response patterns to paper 1 of the MRCGP examination.

OBJECTIVE: To investigate the content validity of Paper 1 of the MRCGP examination. METHOD: Exploratory factor analysis was carried out on candidate responses to Paper 1 of the May and October MRCGP examination in 1998. Contribution of each test question across factors was assessed using a pattern matrix of the oblique rotation. Common dimensions and variations between factor sets were identified. Key testing areas were then matched against the 'domains of competence' intended to be assessed by Paper 1 (as defined within the examination blueprint matrix). RESULTS: Whilst critical appraisal, disease prevention/evidence-based medicine and clinical management emerged as areas tested consistently, content variation was observed between factor sets extracted from both sittings. In addition, some overlap, in terms of domains tested, was seen among other assessment instruments used within the examination. CONCLUSION: Paper 1 conforms to the majority of its stated intentions. However, further development of techniques for investigating validity will be required in order to minimize content variation between both sittings of the examination as well as to help more closely define areas of competence to be tested by Paper 1 of the MRCGP examination.

Education, Medical, Undergraduate↗

A critical review of papers from clinical cancer research.

A review of 75 original articles from clinical cancer research in Norway is presented. Articles published in 1993 and with at least one Norwegian author were included in the review. Sixty papers were observational, whereas 15 were experimental. Of the observational studies 44 were retrospective. Most of the papers concerned prognostic factors. Prior hypotheses were explicitly defined in 16 papers only, and less than half of the articles described inclusion and exclusion criteria. Sample size calculations were performed in four papers only. The choice of statistical method was considered to be suitable in 22 of the 58 articles presenting statistical inferences. Problems related to multiple significance testing were rarely addressed, although the median number of p-values reported was as high as 8. Confidence intervals for main findings were presented in 14 papers. For proper planning of studies, as well as for analysis and interpretation of study results, statistical advice is indeed required.

Clinical Trials as Topic↗

Analysis of paired serum, urine and filter paper blood specimens for presence of filarial antigen by immunoradiometric assay.

Paired serum, urine, and finger-prick whole blood dried on filter paper were analyzed by immunoradiometric assay (IRMA) for filarial antigen using Brugia malayi-specific rabbit antibody. Nine sera and 6 urines from the 10 paired serum-urine samples obtained from individuals with microfilaremia contained IRMA detectable filarial antigen. In contrast, all serum and urine specimens from patients with chronic infections, endemic and non-endemic controls were negative. Whole blood eluted from filter paper spots contained IRMA detectable material; their degree of positivity agreed well with IRMA binding levels obtained with paired urines. Reduced recovery of antigen dried on filter paper was observed at antigen levels less than 10 ng/ml equivalents, presumably due to irreversible absorption onto the filter paper. Urine and finger-prick filter paper blood specimens can be used in the diagnosis of microfilaremic infections that have been associated with circulating antigen in the blood.

Animals↗

Position Paper on urine alkalinization.

This Position Paper was prepared using the methodology agreed by the American Academy of Clinical Toxicology (AACT) and the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT). All relevant scientific literature was identified and reviewed critically by acknowledged experts using set criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not considered. A draft Position Paper was then produced and presented at the North American Congress of Clinical Toxicology in October 2001 and at the EAPCCT Congress in May 2002 to allow participants to comment on the draft after which a revised draft was produced. The Position Paper was subjected to detailed peer review by an international group of clinical toxicologists chosen by the AACT and the EAPCCT, and a final draft was approved by the boards of the two societies. The Position Paper includes a summary statement (Position Statement) for ease of use, which will also be published separately, as well as the detailed scientific evidence on which the conclusions of the Position Paper are based. Urine alkalinization is a treatment regimen that increases poison elimination by the administration of intravenous sodium bicarbonate to produce urine with a pH > or = 7.5. The term urine alkalinization emphasizes that urine pH manipulation rather than a diuresis is the prime objective of treatment; the terms forced alkaline diuresis and alkaline diuresis should therefore be discontinued. Urine alkalinization increases the urine elimination of chlorpropamide, 2,4-dichlorophenoxyacetic acid, diflunisal, fluoride, mecoprop, methotrexate, phenobarbital, and salicylate. Based on volunteer and clinical studies, urine alkalinization should be considered as first line treatment for patients with moderately severe salicylate poisoning who do not meet the criteria for hemodialysis. Urine alkalinization cannot be recommended as first line treatment in cases of phenobarbital poisoning as multiple-dose activated charcoal is superior. Supportive care, including the infusion of dextrose, is invariably adequate in chlorpropamide poisoning. A substantial diuresis is required in addition to urine alkalinization in the chlorophenoxy herbicides, 2,4-dichlorophenoxyacetic acid, and mecoprop, if clinically important herbicide elimination is to be achieved. Volunteer studies strongly suggest that urine alkalinization increases fluoride elimination, but this is yet to be confirmed in clinical studies. Although urine alkalinization is employed clinically in methotrexate toxicity, currently there is only one study that supports its use. Urine alkalinization enhances diflunisal excretion, but this technique is unlikely to be of value in diflunisal poisoning. In conclusion, urine alkalinization should be considered first line treatment in patients with moderately severe salicylate poisoning who do not meet the criteria for hemodialysis. Urine alkalinization and high urine flow (approximately 600 mL/h) should also be considered in patients with severe 2,4-dichlorophenoxyacetic acid and mecoprop poisoning. Administration of bicarbonate to alkalinize the urine results in alkalemia (an increase in blood pH or reduction in its hydrogen ion concentration); pH values approaching 7.70 have been recorded. Hypokalemia is the most common complication but can be corrected by giving potassium supplements. Alkalotic tetany occurs occasionally, but hypocalcemia is rare. There is no evidence to suggest that relatively short-duration alkalemia (more than a few hours) poses a risk to life in normal individuals or in those with coronary and cerebral arterial disease.

Alkalies↗

Electrophoresis of proteins on filter paper.

A simplified procedure for filter paper electrophoresis is described in which disturbing factors such as evaporation, heating, buffer concentration gradients, and pH changes in the electrode vessels were reduced to a minimum. Artificial mixtures of highly purified proteins could be separated and the components isolated. The application of the method to a variety of studies on serum proteins is demonstrated. Protein concentration in paper segments was determined by two different methods of protein estimation. Curves were obtained showing the same five major peaks for normal serum as found by the classical methods of free electrophoresis. Comparisons were made of the areas of the various components under the curves obtained with the different methods. Two dimensional electrophoresis was applied to serum and serum components. It proved of value in demonstrating the heterogeneity of fractions such as the gamma-globulin of serum. The polysaccharide dextran was used as an index of the extent of electro-osmotic flow during the course of the various experiments. The ratio of the distance of electroosmotic flow and the distance of protein migration was shown to be constant for a given type of paper. For serum albumin on Munktell 20 paper this ratio was 0.35. A formula for mobilities applicable to liquid in a highly porous supporting medium is presented. Mobility values for human serum albumin at various pH levels on paper showed approximate agreement with those obtained in free solution giving a similar isoelectric point.

Buffers↗

Oxidative stress and bioindicators of reproductive function in pulp and paper mill effluent exposed white sucker.

This study investigates oxidative stress and bioindicators of reproductive function in wild white sucker (Catostomus commersoni) collected from environments receiving pulp and paper mill effluent discharges in northern Ontario. Samples were collected over an eight-year period adjacent to three pulp and paper mills using a variety of processing and bleaching techniques. Fish collected downstream of pulp and paper mills within the Moose River basin exhibited elevated hepatic and gonadal 2-thiobarbituric acid reactive substances (TBARS), the presence of which is indicative of oxidative stress in these tissues. Within the Jackfish Bay system, exposure to pulp and paper mill effluent did not elevate hepatic or gonadal TBARS. Hepatic cytochrome P4501A activity (CYP1A) and fatty acyl-CoA oxidase (FAO) activities were frequently increased in livers of Moose River basin fish exposed to pulp and paper mill effluent, while lower activities of both enzymes were found within fish from the Jackfish Bay system. This suggests that oxidative stress may be related to CYP1A and FAO activities. Within the Moose River system, increases in measures of oxidative stress (TBARS, FAO) were generally coincident with decreased levels of 17 beta-estradiol; however, testosterone was often lower in Jackfish Bay system fish without any commensurate changes in oxidative stress. The suite of reproductive and oxidative stress parameters measured in this study varied between seasons and mills suggesting responses to effluent are dynamic and effects are complicated by different receiving environments. The relationship between gonad size, gonadal oxidative stress, and circulating plasma steroids remains unclear.

Androgen Antagonists↗

From conference abstract to full paper: differences between data presented in conferences and journals.

BACKGROUND: We studied the type and frequency of differences between data presented in conference abstracts and subsequent published papers in the fields of infectious diseases and microbiology. METHODS: We reviewed all abstracts from the first session of 7 of 15 major research categories presented in the 1999 and 2000 Interscience Conference on Antimicrobial Agents and Chemotherapy. For each selected pair of abstract and related published paper, two independent investigators performed a detailed data comparison. RESULTS: From 190 abstracts reviewed, 68 (36%) were subsequently published as full papers by March 2004. Fifty-two pairs referred to the same study population and period. Differences were found in 30 of 51 pairs, which were further analyzed (point estimate=59%, 95% C.I.: 45-73%). The identified differences were related to both the aims and conclusions of the study (3/30), the study conclusions only (2/30), numbers and/or rates of the studied patients (10/30), numbers or rates of microbiological isolates (9/30), MIC values or K(i) values (5/30), other pharmacological properties of antibiotics (2/30), odds ratio (1/30), and duration of observation (1/30). Some differences were considered major. In bivariable associations, time to publication (from presentation in the conference to publication of the full paper) was associated with identifiable differences between the conference abstract and the full paper (OR=1.76, 95% CI 0.95-3.24/year of delay, P=0.07). CONCLUSIONS: It is reassuring that although we identified several reportable differences, only a very small proportion of studies exhibited differences in their aims and/or conclusions. Researchers may benefit from the above findings in improving the accuracy of presented data.

Abstracting and Indexing↗

A comparative trial of paper-and-pencil versus computer administration of the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire.

BACKGROUND: Although most health-related quality of life questionnaires are self-administered by means of paper and pencil, new technologies for automated computer administration are becoming more readily available. Novel methods of instrument administration must be assessed for score equivalence in addition to consistency in reliability and validity. OBJECTIVES: The present study compared the psychometric characteristics (score equivalence and structure, internal consistency, and reproducibility reliability and construct validity) of the Quality of Life in Reflux And Dyspepsia (QOLRAD) questionnaire when self-administered by means of paper and pencil versus touch-screen computer. The influence of age, education, and prior experience with computers on score equivalence was also examined. RESEARCH DESIGN: This crossover trial randomized 134 patients with gastroesophageal reflux disease to 1 of 2 groups: paper-and-pencil questionnaire administration followed by computer administration or computer administration followed by use of paper and pencil. To minimize learning effects and respondent fatigue, administrations were scheduled 3 days apart. A random sample of 32 patients participated in a 1-week reproducibility evaluation of the computer-administered QOLRAD. RESULTS: QOLRAD scores were equivalent across the 2 methods of administration regardless of subject age, education, and prior computer use. Internal consistency levels were very high (alpha = 0.93-0.99). Interscale correlations were strong and generally consistent across methods (r = 0.7-0.87). Correlations between the QOLRAD and Short Form 36 (SF-36) were high, with no significant differences by method. Test-retest reliability of the computer-administered QOLRAD was also very high (ICC = 0.93-0.96). CONCLUSIONS: Results of the present study suggest that the QOLRAD is reliable and valid when self-administered by means of computer touch-screen or paper and pencil.

Age Factors↗

Sulfadoxine assay using capillary blood samples dried on filter paper--suitable for monitoring of blood concentrations in the field.

A high performance liquid chromatographic method for determination of sulfadoxine in whole blood obtained by finger prick and dried on filter paper is presented. The technique was validated by comparing the sulfadoxine concentration of simultaneously collected capillary blood dried on filter paper and conventional venous whole blood samples. Agreement between capillary blood dried on filter paper and venous whole blood was satisfactory. Limit of determination using 100 microliter of capillary blood was found to be 25 mumol/L (7.8 micrograms/ml). Sulfadoxine was stable in the dried filter papers for at least 15 weeks at +37 degrees C. The concentration ratio between plasma and whole blood of sulfadoxine was found to be approximately 1.8. The sampling technique on filter paper offers a convenient method for overcoming many of the practical problems of blood sampling in the field.

Capillaries↗

A simple 'paper smear' method for dry collection, transport and storage of cervical cytological specimens for rapid screening of HPV infection by PCR.

Human papillomaviruses (HPVs) are major pathogens associated with the development of cancer of the uterine cervix, the most common malignant tumour of women worldwide. Reliable diagnosis of HPV infection, particularly the 'high-risk' types (16/18), may facilitate early identification of 'high-risk' populations for developing cervical cancer and may augment the sensitivity and specificity of primary cervical cancer screening programmes by complementing the conventional Pap test. A simple paper smear method has been developed for dry collection, transport and storage of cervical smears/scrapes at room temperature for subsequent detection of HPV DNA by PCR assay. Imprint biopsies, blood and fine-needle aspirates were also collected by this method. The cervical scrapes or other body fluids were smeared (within 0.5-1 cm diameter) and dried on to sterile small slides made of Whatman 3MM filter paper, and stored individually at room temperature or at 4 degrees C. A small piece (2-3 mm) of the paper smear was punched or cut out with a sterile surgical blade, boiled in an eppendorf tube containing 50 microl of distilled water for 5 min and used directly for PCR amplification. The quality and quantity of DNA derived from paper smears and the results of PCR amplifications for HPV type 16, BRCA1 and p53 genes were identical to those obtained from the same samples following collection in PBS, storage (-70 degrees C) and phenol-chloroform-based DNA extraction. DNA was stable in the paper smears for up to a year, whether stored at room temperature or at 4 degrees C. This method is simple, rapid and cost-effective, and can be effectively employed for large-scale population screening, especially for regions where the specimens are to be transported from distant places to the laboratory.

DNA, Viral↗

The impact of papers in Sociology of Health and Illness: a bibliographic study.

This paper examines the citation counts of papers published in the first 25 years of the Sociology of Health and Illness. According to this measure only a small number of papers have made a major impact on the discipline of sociology of health and illness and an analysis of these select papers identifies some common themes. In particular, 'successful' papers have provided important theoretical constructs for the field while exploration of aspects of identity has been a recurrent focus.

Bibliometrics↗

Examination of Hardy-Weinberg equilibrium in papers of Kidney International: an underused tool.

BACKGROUND: Population-genetic studies investigating genetic polymorphisms of Mendelian inheritance should always test whether the measured genotype frequencies deviate from the expected one. For this purpose Hardy-Weinberg (HW) criteria are generally used. If genotype distribution of control population misses HW equilibrium, the results should be treated cautiously because the observed genotype distribution in control population does not represent genotype distribution in the overall population. If HW criteria are not fulfilled in the investigated population, this may be further evidence for the correlation between genotype and investigated condition. METHODS: Between September, 1998, and September, 2003, we tested papers published in Kidney International if HW criteria were ordinarily and correctly checked in studies investigating genetic polymorphisms. Seventy-five genotype distributions of the selected 39 articles were reanalyzed. RESULTS: HW calculation was reportedly performed in 25 papers (64%). The observed genotype distribution deviated significantly from the expected one in three control, and in 16 patient populations and in three populations of association studies of 15 papers overall; however, this fact was not mentioned in 12 papers. CONCLUSION: Although the deviation of genotype distribution from the expected one is important information, HW calculations are not performed routinely for each investigated subject groups in these papers investigating genetic polymorphisms.

Alleles↗

Citation indexing and evaluation of scientific papers.

Evaluation by means of citation patterns can be successful only insofar as published papers and their bibliographies reflect scientific activity and nothing else. Such an innocent descrip tion is becoming less and less tenable. The present scientific explosion gave rise to more than a proportional pub lication explosion, which not only re flects the scientific explosion but has its own dynamics and vicious circles. Publication of results is probably the main means of accomplishing the al most impossible task of accounting for time and money spent on research. Inevitably, this puts a premium on quantity at the expense of quality, and, as with any other type of inflation, the problem worsens: the more papers are written, the less they count for and the greater is the pressure to publish more. What makes matters worse is the fact that the sheer volume of the"litera ture" makes it increasingly difficult to separate what is worthwhile from the rest. Critical reviews have become somewhat of a rarity, and editorial judgment is usually relegated to ref erees, who are contemporaries and, per haps, competitors of the authors-a situation which has its own undesirable implications (11, 18). It requires little imagination to discover other vicious circles, all arising from distortion of the primary reasons for publishing the results of scientific inquiry. There are, it is true, signs of ad justment to this crisis, partly due to some easing of the pressure to pub lish at all costs, and partly due to the readers' changing attitudes toward the flood of publications. An increasing amount of research is now being car ried out in the form of collective proj ects in large institutions where publica tion is no longer the standard method of accounting for individual work. At the same time there is apparent an in creasing tendency for scientific journals to polarize into the relatively few leading ones which carry important informa tion and the many subsidiary journals which serve as vehicles for interim lo cal accounting and, in a way, sub stitute for detailed intradepartmental re ports. This division is a result not of some arbitrary decree but of normal competition between journals, as a re sult of which, however, the strong usual ly get stronger and the weak get weaker. Were it not for these changes and also for a striking improvement in abstracting, indexing, and alerting serv ices, most research workers would have found long ago that, even in their own specialized fields, new information is accumulating faster than it can be sorted out. These developments can pro vide only a temporary reprieve, so long as there remains a strong incentive to publish the greatest possible number of papers. A new scale of values based on citations is by no means infallible or, in many cases, even fair, but at least it provides an alternative to the existing one, which is at the root of the crisis. It might, of course, be asked whether wide acceptance of such new stand ards would not lead to deliberate abuses. A little reflection shows that the system is less open to manipula tion than might appear. First, the ref erees are expected to see to it that the submitted papers cite work which is pertinent to the subject. An increased awareness of the usefulness of citation indexing as a tool for retrieval and evaluation will make this aspect of refereeing more important, and what now passes for minor carelessness or discourtesy could easily come to be regarded as serious malpractice. Sec ond, as noted above, careful selection of references is in the author's own interest, because it helps him to reach his readers. There is, therefore, some room for hope that healthy feedback in the system will tend to keep it viable. At the basis of this hope lies the supposition that, in the long run, only good work can ensure recognition. As Martyn (2) has pointed out, as an information-retrieval method, cita tion indexing is rather "noisy." The word noisy may apply even more to the problem of evaluation. Whereas in information retrieval much of the unwanted information can be filtered out by suitable search strategy (2, 6), this is not so easy to do for the pur pose of evaluation, because a simple descendence relationship between papers is still an ideal far removed from actuality (7). The situation would be much better if we could at will exclude all citations which do not indi cate real indebtedness. A scheme of citation relationship indicators, first men tioned by Garfield (12) and elaborated by Lipetz (17), would be a help, but, even if it were technically feasible, to provide such indicators would greatly add to the production costs of the Index. Another possible way to minimize the effects of "noise" is to increase the size of the samples on which the reckon ing is based. Now that research has be come a rather popular occupation, it seems that a kind of public vote may have to be accepted as a factor in evaluation. Since this is the case, there is something to be said for extending the "franchise" to minimize acciden tal effects. An index which attempted to process all scientific publications would be several times the size of the present Index, and, what is more, it would not necessarily be an improve ment as a tool for information retrieval because most of the significant work is already concentrated in the present Index. Whether this attempt will ever be considered worthwhile remains pri marily a matter of policy and eco nomics. In the meantime there is an urgent need for more experience with the existing services. It is not the purpose of this article to advocate evaluation of scientific work by some kind of public opinion poll; its purpose is to recognize a pos sible trend in this direction. Any judg ment by public acclaim is subject to obvious fallacies, but we must not be carried away by the analogy to the Stock Exchange or to electoral prac tices. The fact that, in this case, the "public" consists of authors whose con tributions are generally linked creates quite a new pattern of organization. In this discussion some of the aspects of this pattern have been explored through analogy to idealized genetic or mechani cal network models, but the very uniqueness of the system, with its many self-organizing ramifications, makes it a new field which deserves close study, since these developments may have pro found effects on the future of scientific communication.

Abstracting and Indexing↗