Serious Errors Of Interpretation Research Articles

Study and Characterization of Special Gypsum-Based Pastes for Their Use as a Replacement Material in Architectural Restoration and Construction.

Within the construction sector, the use of gypsum-based pastes features in the majority of monuments, giving this material significant relevance in conservation and restoration projects affecting the world’s cultural heritage. In this research, we evaluated special gypsum-based colored pastes mixed with air lime, hydraulic lime and sodium silicate, and eight different pigments for their use as replacement materials in architectural restoration and construction. We analyzed the suitability of their physical and chemical properties and their hydric characteristics, mechanics and colorimetric implications in two different studies after 28 days and 120 days. The characterization of the products has mainly confirmed the suitability of the pastes containing pigments for use in the most common applications for these kinds of mixes, highlighting that their specific capacities are worth leveraging. The crystallization of gypsum minerals, observed in all of the mixes, helps to consolidate the shrinkage cracks which appear inside the pastes, improving their mechanical strength values. Another observation of the pastes is related to the amorphous silica precipitates in the mixes which contained sodium silicate: the latter provided to them good mechanical behavior. The improvement observed in the pastes containing the green earth pigment is substantial, due to the inclusion of aluminum silicates and Mg, which is partly responsible for the increased compressive strength of the pastes. Finally, the colorimetric analysis is of vital importance in determining the loss of intensity of the colors of the pastes used, since subjective observation leads to serious errors of interpretation.

Characterization and chromatic evaluation of gypsum-based pastes for construction and heritage restoration

This research evaluates the chromatic behavior of gypsum-based pastes containing added pigments which enable their use in both new construction projects as well as in restoration interventions for built heritage. Furthermore, the impact of adding pigments to the aforementioned material after twenty-eight and ninety days has also been studied. This was confirmed by carrying out compositional, mineralogical and physical studies of the raw materials and the pastes. The results indicate that all of the pastes studied have suitable mechanical strength values for the type of pastes studied, thereby confirming their suitability for on-site use based on their characteristics and behavior. Colorimetric analysis showed color variations that were clearly perceptible to the human eye, related to increases in luminosity which significantly exceeded 100%, and also to saturation losses featuring percentage variations of more than 100% on assessment after ninety days. This colorimetric analysis by means of quantitative spectrophotometry is of vital importance when determining the loss of color intensity of the pastes used, since subjective observation results in serious errors of interpretation. This type of study reflects the use of instrumental color measurements for this type of materials and mixtures.

Evolutionary demand: a model for boundedly rational consumers

The paper is based on the acknowledgement that properties of markets stemming from features of demand are too frequently overlooked in the economic literature, particularly among evolutionary scholars. The overall goal is to show that “demand matters” to understand properly observed properties of markets not only because of its exogenous (i.e. non-economic) features, but also because of aspects of consumers’ behavior that fully deserve to be considered in the domain of economics. The paper presents a general model of the consumer based on a bounded rational decision algorithm. The model is shown to be compatible with available evidence on consumers’ behavior and adaptable for theoretical as well as empirical applications. The description of the proposed model’s components provides the opportunity to discuss a number of issues the importance of which for the analysis of markets of markets becomes evident taking a demand-oriented perspective. Among these, we propose a formal definition of preferences meant as decision criteria used by consumers and distinct from the actual decisions made by consumers at each purchasing occasion. We also highlight the potential role of firms’ marketing in shaping consumers’ preferences, suggesting an endogenous channel of influence on consumers’ preferences which is possibly highly relevant in certain markets. We use the model to show that the proposed model can easily replicate a generic market demand function, with the advantage of more robust foundations and greater flexibility in respect of standard consumer theory. We also show that limiting to consider distributional properties of markets, neglecting the type of demand, may lead to serious errors of interpretation.

A trick of the light: the optical properties of living cytoplasm which can mislead

Our understanding of the dynamic chemical changes within living cells has increased enormously as a direct result of imaging and manipulating techniques which rely on the use of light to penetrate the cell. These optical techniques are at the intersection of the three sciences: physics, chemistry and biology. However, the understanding of the physics of illumination (e.g. lasers, confocal microscopy) and the chemistry of fluors (synthetic and protein) is way ahead of the understanding of the biological interface posed by the cell itself. In this critical review we will show that ignoring the optical properties of living cells can lead to serious errors of interpretation and that even seemingly compelling images can result from a "trick of the light".

Correct identification of species makes the amoebozoan rRNA tree congruent with morphology for the order Leptomyxida Page 1987; with description of Acramoeba dendroida n. g., n. sp., originally misidentified as ‘ Gephyramoeba sp.’

Morphological identification of protists remains an expert task, especially for little known and poorly described species. Culture collections normally accept organisms under the name provided by depositors and are not responsible for identification. Uncritical acceptance of these names by molecular phylogeneticists may result in serious errors of interpretation of phylogenetic trees based on DNA sequences, making them appear more incongruent with morphology than they really are. Several cases of misidentification in a major culture collection have recently been reported. Here we provide evidence for misidentifications of two more gymnamoebae. The first concerns “Gephyramoeba sp.” ATCC 50654; it is not Gephyramoeba, a leptomyxid with lobose pseudopods, but a hitherto undescribed branching amoeba with fine, filamentous subpseudopods named here Acramoeba dendroida gen. et sp. nov. We also sequenced 18S rRNA of Page's strain of Rhizamoeba saxonica (CCAP 1570/2) and show that it is the most deeply branching leptomyxid and is not phylogenetically close to ‘Rhizamoeba saxonica’ ATCC 50742, which was misidentified. Correcting these misidentifications improves the congruence between morphological diversity of Amoebozoa and their rRNA-based phylogenies, both for Leptomyxida and for the Acramoeba part of the tree. On morphological grounds we transfer Gephyramoebidae from Varipodida back to Leptomyxida and remove Flamella from Leptomyxida; sequences are needed to confirm these two revisions.

PULSE OXIMETRY

Background/Aim: Pulse oximetry has emerged as a clinical tool inanesthesia and is becoming popular in developing countries. Unfortunately, its use is usually not accompanied byappropriate staff training. The aim of this study was to evaluate the knowledge about pulse oximetry among the 7th yearmedical student Interns (MS) and nursing staff (NS) of Intensive Care Unit (ICU), Coronary Care Unit (CCU) andRecovery Room (RR) of four medical-school affiliated hospitals in Shiraz, Iran. Study Period: Feb 2001- Feb 2002Materials and Methods: A 14-item questionnaire (4 demographic and 10 knowledge), multiple-choice and open ended,was developed to assess knowledge of pulse oximetry. Among 150 7th year medical students and 200 nursing staff,40 from each group was randomly selected and invited to complete the questionnaire. Results: A 100% response ratewas achieved. All of the participants used pulse oximetry regularly in their daily work. The mean test scores for MS andNS were 60.5 ± 21 and 49 ± 17%, respectively (p < 0.05). None of the participants had adequate training in the useof pulse oximetry. Conclusion: Our study revealed that medical students and staff nurses were untrained in pulseoximetry, lacked knowledge of basic principles, and made serious errors in interpretation of readings. Therefore, werecommend that medical schools and nurse training programs place emphasis on teaching the principles andapplications of pulse oximetry and the oxyhemoglobin dissociation curve.

How the Probability of a False Positive Affects the Value of DNA Evidence

Errors in sample handling or test interpretation may cause false positives in forensic DNA testing. This article uses a Bayesian model to show how the potential for a false positive affects the evidentiary value of DNA evidence and the sufficiency of DNA evidence to meet traditional legal standards for conviction. The Bayesian analysis is contrasted with the "false positive fallacy," an intuitively appealing but erroneous alternative interpretation. The findings show the importance of having accurate information about both the random match probability and the false positive probability when evaluating DNA evidence. It is argued that ignoring or underestimating the potential for a false positive can lead to serious errors of interpretation, particularly when the suspect is identified through a "DNA dragnet" or database search, and that ignorance of the true rate of error creates an important element of uncertainty about the value of DNA evidence.

A Study of Dictionary Use by International Students at a British University

This paper reports on an investigation into the dictionary‐using habits of international students studying in the medium of English at a British University. Over a period of three years, six groups of students were set assignments requiring them to report on the way they had consulted dictionaries to find the meanings of unknown words in texts of their choice. Eighty‐nine assignments were analysed, to reveal subjects' choices of reading material, look‐up words and dictionaries. The data also showed that whilst the majority of words were looked up successfully, more than half the subjects were unsuccessful in at least one out of five dictionary consultations. Subjects were found to have particular difficulty in selecting appropriate entries and sub‐entries in their dictionaries. Some consultation problems resulted in serious errors of interpretation, which subjects were largely unaware of.

Assessment of the value of technician reporting of electrocardiographs in an accident and emergency department.

OBJECTIVE: To assess the value of a cardiac technicians' report on electrocardiographs (ECGs) in reducing serious errors of interpretation by senior house officers. METHODS: A parallel study of interpretation of...

Reaction of Nitric Oxide with Acetylene and Oxygen: Implications for Denitrification Assays

AbstractNitric oxide reacts with C2H2 at ambient temperature under aerobic conditions with relatively large quantities of O2 present. We used a gas‐flow system at 20°C to determine the extent, if any, of reaction of NO with C2H2 under nearly anaerobic conditions with addition of trace (<500 µL L−1) quantities of O2, and to determine whether the process could account for the apparent C2H2 inhibition of NO production in soil. Results showed that reaction occurred only when critical trace quantities of O2 were present. For example, if [NO] was in the range 0.5 to 2.5 µL L−1, which is typical of concentrations in our soil studies, approximately 200 to 300 µL O2 L−1 was required before measurable NO loss was observed. The reaction was first order with respect to NO and variable order, becoming zero order, with respect to O2 when [O2] exceeded ≈400 µL L−1 and maximum NO depletion rates (≈0.01–0.06 µL L−1 s−1) were obtained. The effect of C2H2 on NO production with addition of O2 (≈20–730 µL L−1) in Brookston clay loam (fine‐loamy, mixed, mesic Typic Argiaquoll) and Fox sandy loam (fine‐loamy over sandy or sandy‐skeletal, mixed, mesic Typic Hapludalf) under conditions similar to the gas‐phase studies was also investigated. Depletion of NO in the presence of C2H2 vs. [O2] followed the same pattern with similar rates as the gasphase process. A simplified C2H2‐catalyzed scheme for the oxidation of NO to NO2 provides a plausible, partial explanation for these results. Since NO depletion requires only trace amounts of O2, the results suggest that in many previous studies involving assays of NO or N2O production based on C2H2 inhibition, significant gas‐phase reaction may have occurred leading to serious errors of interpretation.

Knowledge about pulse oximetry among medical and nursing staff

SummaryAlthough pulse oximeters are increasingly used to monitor patients on medical and surgical wards, staff seem to receive no specific training in the operation of these devices. We investigated the knowledge of junior doctors and nursing staff about pulse oximetry as used on seriously ill patients in a District General Hospital in Exeter, UK. 30 medical or surgical preregistration house officers or senior house officers and 30 staff nurses answered a structured questionnaire. Questions were asked about the theory behind pulse oximetry, factors affecting readings, "normal" values in various patients, values in hypothetical clinical situations, and what training subjects had received. Responses were scored against standard answers from reference texts. 97% of doctors and nurses did not understand how a pulse oximeter worked and were confused about factors influencing readings. Respondents gave a wide range of acceptable saturation values (eg, 90-100% for a fit adult), thus demonstrating poor understanding of physiological principles. There were serious errors made in evaluating saturation readings in hypothetical clinical situations. Only 1 doctor had received formal training in the use of pulse oximetry.Our survey revealed that junior doctors and staff nurses were untrained in pulse oximetry, lacked knowledge of basic principles, and made serious errors in interpretation of readings. Training is needed for staff who use pulse oximeters.

Cardiovascular Dysfunction

Traditional clinical assessment of cardiac function has relied on the indirect measurement of systemic blood pressure, heart rate and rhythm, and central venous pressure. However, because the circulation comprises complex interactions between flow and impedance in two hydraulic systems coupled in series, the usual assumptions drawn from the measurement of only a representative sample of this system can lead to serious errors in interpretation. This is particularly significant in conditions leading to physiologic distortions. Patients undergoing major surgery, or with suspected cardiac dysfunction, can only be adequately managed with a knowledge of both right and left heart pressures, together with the measurement of cardiac output. This report presents a rationale for the use of a simple method for interpreting these data and a guide to optimizing management. For those patients with heart failure who are unable to be sustained with conventional pharmacology, criteria are suggested that may help the clinician decide when more aggressive intervention, such as mechanical assist, is required.

Comparison of total tuber yields from inner and guard rows used in potato (Solanum tuberosum L.) fertiliser experiments

Total tuber yields were compared for inner and outer (guard) rows from 4 phosphorus (P) and 3 nitrogen (N) field experiments conducted during 1985-86 in South Australia, and from 5 N and 2 potassium (K) field experiments conducted during 1985-86 and 1987-88 in Tasmania. All fertiliser treatments were banded along the rows, either at planting or part at planting and the remainder sidedressed after emergence. The inter-row spacings were in the range 76-86 cm and the cultivars used were Kennebec, Coliban and Russet Burbank. Analysis showed that at only 1 of the 14 sites (site 6 in South Australia) was the mean total tuber yield for the inner 2 rows significantly (P<0.01) less than the mean total tuber yield for all 4 rows. However, the difference was small (0.8 t/ha or 1.9%) and of little practical importance. The relationships between mean (� s.e.) total tuber yield and rate (kg/ha) of applied nutrient (0-240 P, 0-320 N, 0-400 K) for inner and guard rows showed that differences between means were small and usually within standard error ranges at all sites. There were no consistent differences in the magnitudes of the standard errors of the means for inner and guard rows for all rates and types of nutrient applied. No significant cross-feeding occurred in these fertiliser experiments, which suggests that omission of guard rows from experiments where the fertiliser treatments are applied along the rows should not result in serious errors of interpretation of tuber yield response.

Chemistry of the rock‐forming silicates: Ortho, ring, and single‐chain structures

The crystal chemistry of 21 ortho, ring, and single‐chain silicate structures is reviewed. Structure drawings are presented to portray the essential crystal chemical features necessary to correctly interpret chemical data for each mineral or mineral group. The groups considered are olivine, humite, zircon, sphene, garnet, vesuvianite, aluminosilicate, topaz, staurolite, chloritoid, epidote, melilite, beryl, cordierite, tourmaline, axinite, pyroxene, pyroxenoid, pectolite, sapphirine, and aenigmatite. Electron microprobe data for each group can be interpreted with various degrees of rigor, depending on whether H2O, Fe2+/Fe3+, and other elements not detected by the microprobe are present. Serious mineral chemists are encouraged to determine Fe2+/Fe3+ and H2O directly. Estimates of these values using microprobe data are usually imprecise and can lead to serious errors in interpretation of the chemical formula and thus any thermodynamic or petrologic inferences that are based on the correct formula.

Velocity Characteristics of Confined Coaxial Jets With and Without Swirl

Measured values of the velocity characteristics of turbulent, confined, coaxial-jet flows have been obtained, without swirl, for ratios of maximum annulus to pipe velocities of 1.0 and 3.0 and with a swirl number of 0.23 for a velocity ratio of 3.0. They were obtained by a combination of pressure probes, hot-wire and laser-Doppler anemometry. The results are compared with calculations, based on the solution of finite-difference forms of the steady, Navier-Stokes equations, and an effective-viscosity hypothesis. The measurements allow the influence of confinement and swirl to be quantified and show, for example, the increased tendency towards centerline recirculation which results from both. The results with the three types of instrumentation allow a comparison within the corner recirculation region which reveals that serious errors of interpretation of mean-velocity measurements need not arise. The two-equation model, although able to represent the non-swirling flow is less appropriate to the swirling flow and the reasons are indicated.

Misleading Data Bases: An Example from Kidney Transplantation

In recent years, transplantation survival data have also been documented by whether the patient was nephrectomized or not. Certain conclusions were drawn from the data but the inference contains serious errors in interpretation. This paper attempts to point these errors out, investigate their source, and suggest guidelines for creating a data base from which meaningful conclusions can be drawn. The discussion may be generalized to many other data bases in the medical field.

Letter: Transient benign unilateral pupillary dilation.

To the Editor.— Despite their awareness of the value of pilocarpine 0.5% in differentiating mydriasis produced by pharmacologic blockade from that secondary to parasympathetic paralysis, Edelson et al in the July issue of the ARCHIVES (31:12, 1974), failed to use this substance in their own cases. My own recent experience with a case of this type suggests that failure to perform the test may give rise to serious errors of interpretation. Report of a Case.— A 15-year-old female inpatient was first seen on Oct 23, 1973, while she was recovering from an episode of right unilateral mydriasis. She had been admitted to the hospital on the afternoon of Oct 10 when she experienced the sudden onset of right supraorbital pain in right pupillary dilation. A neurologic examination on the morning of the day of admission showed the pupils to be equal and normally reactive to light. Examination on Oct 23

Derzhavin's Biostatistical Method of Population Analysis

Derzhavin's biostatistical method, as modified by Boiko and others, uses annual age censuses and catch statistics to compute the utilized stock (virtual population), Vi, of year-class i in a given year as the sum of all members of that year-class that are caught in the current and future years. The sum of Vi values for all year-classes present in a given year is the total utilized population, V. The biostatistical rate of exploitation for individual ages (Ci/Vi), or for the stock as a whole (C/V), is the catch divided by the utilized stock. If ages of the fish in the stock are read too low, values of Ci/Vi and C/V are too large. For fully recruited fish, Ci/Vi is an unbiased estimate of the total mortality rate, A, bat for incompletely recruited ages, it differs progressively from A and has no simple interpretation. Variations in abundance of successive year-classes do not affect the interpretation of Ci/Vi or C/V for fully recruited ages, but changes in rate of fishing, F, are disturbing. When incompletely recruited ages are included in a biostatistical computation (as has usually been done), C/V does not have any precise interpretation in terms of population parameters. In addition, variations in year-class strength affect the value of C/V even when F does not change from year to year. It is possible to use C/V for the whole catch as an "arbitrary" index that reflects the direction and magnitude of changes in intensity of fishing over a period of years. However, even for this purpose the same minimum age must be used in all years. When data for a long series of years are available, the utilized year-class strength (ΣCi) of the year-class hatched in year i can be compared with the total utilized stock (or the utilized mature stock) present in year i, in order to examine parent–progeny relations. Incompletely recruited as well as fully recruited ages can be used in this comparison, but adjustments are necessary if mortality rate (natural or fishing) changes from year to year. The biostatistical method does not provide separate estimates of natural and fishing mortality rates. If the possibility of a moderate or large natural mortality is disregarded, serious errors of interpretation may result.

Analysis of Certain Errors in Squid Axon Voltage Clamp Measurements

Localized membrane current and potential measurements were made on the squid giant axon in voltage clamp experiments. Spatial control of potential was impaired by the use of axial current supplying electrodes with surface resistance greater than 20 ohms for a centimeter length of axon. No region of membrane which was indeed subjected to a potential step showed more than one inward current peak. Other patterns were results of space clamp failure. Membrane current and potential patterns during space clamp failure were approximately reproduced in computations on a model containing two membrane patches obeying the equations of Hodgkin and Huxley. Non-uniformities in the axon or electrodes are not necessary for non-uniform electrical behavior. An extension of the core conductor model which includes the axial wire and external solution has been analyzed. The space constant of electrotonic spread is less than 0.5 mm with a usable electrode. Errors of about 5 per cent are introduced by ignoring the external solution. Resistance between the membrane and the control electrodes reduces the control and a few ohm cm(2) could lead to serious errors in interpretation.

Tonometer calibration. II. Ocular rigidity.

Ocular rigidity is the term used to describe the relationship between pressure and volume changes in the eye. The rigidity of the eye is provided mainly by the sclera and cornea, which, however, are not completely unyielding but undergo an appreciable amount of stretching and contracting as a result of variations in the intraocular pressure. The application to the cornea of an impression tonometer, such as that of Schiøtz, produces a rather large change in pressure due to the weight of the instrument and the resulting displacement of intraocular fluid. Therefore, if the rigidity of the ocular coats can be shown to vary to any extent from eye to eye serious errors in interpretation of tonometer readings may result. This is true because tonometer conversion scales are based on an assumed average normal value for rigidity. Friedenwald¹determined that the data on rigidity of the eye obtained by Koster,