Similarity interference in learning and retrieving arithmetic facts.

Storing the solution of simple calculations in long-term memory is an important learning in primary school that is subsequently essential in adult daily living. While most children succeed in storing arithmetic facts to which they have been trained at school, huge individual differences are reported, particularly in children with developmental dyscalculia, who show a severe and persistent deficit in arithmetic facts learning. This chapter reports important advances in the understanding of the development of an arithmetic facts network and focuses on the detrimental effect of similarity interference. First, at the retrieval stage, connectionist models highlighted that the similarity of the neighbor problems in the arithmetic facts network creates interference. More recently, the similarity interference during the learning stage was pointed out in arithmetic facts learning. The interference parameter, that captures the proactive interference that a problem receives from previously learned problems, was shown as a substantial determinant of the performance across multiplication problems. This proactive interference was found both in children and adults and showed that when a problem is highly similar to previously learned ones, it is more difficult to remember it. Furthermore, the sensitivity to this similarity interference determined individual differences in the learning and retrieving of arithmetic facts, giving new insights for interindividual differences. Regarding the atypical development, hypersensitivity-to-interference in memory was related to arithmetic facts deficit in a single case of developmental dyscalculia and in a group of fourth-grade children with low arithmetic facts knowledge. In sum, the impact of similarity interference is shown in the learning stage of arithmetic facts and concerns the typical and atypical development.

When there seem to be no predetermining factors: early child and proximal family risk predicting externalizing behavior in young children incurring no distal family risk.

The main objective of the current study was to examine the impact of two child risk factors, i.e. personality and inhibition, and two proximal family risk factors, i.e. parenting and attachment, and the impact of their cumulative effect on later externalizing behavior among young children incurring no distal family risk. Data were collected in a longitudinal two-wave design from 161 non-referred and referred children aged three to five years at the onset of the study. All of the children were raised in families of middle to high socio-economic status, i.e. their parents were educated to a middle to high level, had access to the job market and lived together as couples. The four risk domains were assessed at the onset of the study, while EB was rated both at the onset of the study and in the 24-month follow-up. Results confirmed that the four risk domains were each both correlates of EB and efficient at discriminating non-referred from referred children; that their combination regardless of their content (cumulative risk) provided a strong prediction of both later EB and non-referred vs referred sample membership. The results are discussed both for research and clinical purposes.

[Comparison between the quality of life and nutritional status of nutrition students and those of other university careers at the Santo Thomas University in Chile]. / Comparación en calidad de vida y estado nutricional entre alumnos de nutrición y dietética y de otras carreras universitarias de la Universidad Santo Tomás de Chile.

OBJECTIVE: To determine and compare the quality of life, nutritional status, and self-perceived body image between nutrition students and students from other careers from the University Santo Tomás-Viña del Mar. METHODS: We evaluated 200 student volunteers (100 nutrition students and 100 students from other careers) with a quality of life survey, a nutritional evaluation, and a survey of body image perception. RESULTS: The group of nutritional students perceived a lower quality of life, consumed less tobacco, and was less sedentary. Women of the nutritional group had a lower BMI and showed a lower hip circumference. Men of the nutritional group also showed a lower hip circumference. The nutritional group consumed more milk, chicken, and fish in their diet. Both groups presented an elevated consumption of alcohol. The concordance between BMI and body image was low, 34% in the nutritional group and 38% in the other careers group (Kappa 0.04 and 0.02). CONCLUSION: With respect to perception of quality of life, students from other careers perceived a better quality of life, however students from the nutritional group presented better nutritional status and selection of food.

Involvement of short-term memory in complex mental calculation.

The aim of this study was to examine the involvement of the short-term memory system in complex mental addition by manipulating the phonological and visual similarity of two numbers to be added. The phonological similarity of the problems appeared to have a major effect on both speed and accuracy. However, the manipulation of visual similarity failed to have any measurable impact. This suggests that the phonological loop, rather than the visual-spatial sketch pad, would be used preferably for temporary storage of addends. An interpretation of these results in terms of the nature of the internal code underlying this task is discussed.

Does language really matter when doing arithmetic? Reply to Campbell (1998)

Campbell (1998) has questioned the conclusion of Noël et al. (1997) and has argued that alternative analyses of their data provide strong evidence that arithmetic performance is subject to reading-based interference and provide some support for the language-specificity of number-fact memory. We consider that Campbell reached conclusions different from those we had obtained because (1) he performed his analyses on a different data set (i.e. including also the table-unrelated errors), (2) he has given a double weight to the naming errors and (3) he has multiplied the analyses without correcting the corresponding P values. We thus consider that there exist interactions between language and performance in simple multiplication tasks, but that the current data can easily be explained without postulating that such interactions operate at the level of the retrieval stage. In other words, we consider that there are not definitive arguments, as yet, in favour of the hypothesis of modality-specific arithmetical-fact networks.

The Whorfian hypothesis and numerical cognition: is 'twenty-four' processed in the same way as 'four-and-twenty'?

Recent theoretical developments have redefined a Whorfian effect as a processing difference due to the language of the individual, and no longer as a marker for or against linguistic determinism. Within this framework. Whorfian effects can be used to investigate whether a particular part of the cognitive system is penetrable by language processes or forms an encapsulated module, provided the experimenter ensures that the target language difference is not caused by peripheral input or output processes. In this article, we examine the possibility of a Whorfian effect in numerical cognition by making use of the fact that in the Dutch number naming system the order of tens and units is reversed (i.e. 24 is read 'four-and-twenty'). In a first experiment, we asked native French- and Dutch-speaking students to name the solution of addition problems with a two-digit and a single-digit operand (e.g. 20 + 4 =?, 24 + 1 =?). The order of the operands was manipulated (20 + 4 vs. 4 + 20) as well as the presentation modality (Arabic vs. verbal). Three language differences emerged from this study. Experiment 2, however, showed that these differences were all due to input or output processes rather than differences in the addition operation (i.e. the differences between Dutch and French disappeared when subjects were asked to type the answer rather than pronounce it). On the basis of these findings, we question the idea that mathematical operations are based on verbal processes.

Bone marrow transplantation from HLA-identical siblings as first-line treatment in patients with myelodysplastic syndromes: early transplantation is associated with improved outcome. Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation.

Allogeneic bone marrow transplantation (BMT) offers a potential cure for younger patients with myelodysplastic syndromes (MDS) or secondary acute myeloid leukemia (sAML). More than 600 patients from 50 European centers have now been reported to the European Group for Blood and Marrow Transplantation (EBMT). We retrospectively analyzed 131 patients reported to the Chronic Leukemia Working Party of the EBMT who underwent BMT from HLA-identical siblings without prior remission induction chemotherapy. At the time of BMT 46 patients had refractory anemia (RA) or RA with ringed sideroblasts, 67 patients had more advanced MDS subtypes and 18 patients had progressed to sAML. The 5-year disease-free (DFS) and overall survival (OS) for the entire group of patients was 34 and 41%, respectively. Fifty patients died from transplant-related complications, most commonly graft-versus-host disease and/or infections. Relapse occurred in 28 patients between 1 and 33 months after BMT, resulting in an actuarial probability of relapse of 39% at 5 years. DFS and OS were dependent on pretransplant bone marrow blast counts. Patients with RA/RARS, RAEB, RAEB/T and sAML had a 5-year DFS of 52, 34, 19 and 26%, respectively. The 5-year OS for the respective patient groups was 57, 42, 24 and 28%. In a multivariate analysis, younger age, shorter disease duration, and absence of excess of blasts were associated with improved outcome. From these data we conclude that patients with myelodysplasia who have appropriate marrow donors, especially those aged less than 40 years and those with low medullary blast cell count should be treated with BMT as the primary treatment early in the course of their disease. Transplantation early after establishing the diagnosis of MDS may improve prognosis due to a lower treatment-related mortality and a lower relapse risk.

About the influence of the presentation format on arithmetical-fact retrieval processes.

This article presents the results of two experiments. In Experiment 1, French-speaking participants were asked first to retrieve the product of two numbers presented in Arabic or verbal code, and then to perform a number-matching task on the same material to assess the encoding time difference between numerals in the two formats. Experiment 2 involved the same multiplication task with Dutch-speaking participants who name two-digit numbers in reverse order. The format effects obtained by Campbell and Clark (1992); Campbell (1994) for multiplication were replicated. However, several observations suggest that some of these effects may be due to encoding time differences between word and digit numerals. The same size-by-format interaction was found for the number-matching task as for the multiplication task, and the effect disappeared with practice in the multiplication task. Finally, despite the fact that the linguistic structure of number names differs between French and Dutch, the types of error produced in both groups were identical. The last result does not match with the hypothesis that operand intrusion errors are due to interference between reading processes and arithmetical-fact retrieval processes. Implications of these findings for the debate about the nature of arithmetical-fact retrieval are discussed.

[Tuberculosis, mycobacterium infection and hairy cell leukemia]. / Tuberculose, infection à mycobactéries et leucémie à tricholeucocytes.

OBJECTIVES: Diagnosis of tuberculosis and/or mycobacteria infection is particularly difficult in immunocompromised patients. PATIENTS AND METHODS: We examined the clinical presentation, means of diagnosis, treatment and outcome of tuberculosis in a retrospective study of 6 patients among 75 with hairy cell leukemia diagnosed from 1982 to 1995. RESULTS: Hearlding symptoms of tuberculosis diagnosis were: fever (6/6), weight loss (4/6), pleural effusion (1/6), superficial adenopathy (1/6), persistence of cytopenia or splenomegaly during the treatment of hairy cell leukemia. Pulmonary symptoms were present in only two cases. Diagnosis was obtained by positive culture of mycobacteria in 2 cases (Mycobacterium tuberculosis in pleural effusion, Mycobacterium kansaii in adenopathy). Microbiological diagnosis was never obtained from sputum (6/6). Diagnosis was obtained by histopathology in all cases: from bone marrow (2 cases), lymph nodes (2 cases), liver (1 case), spleen (1 case), umbilical fat (1 case). Tuberculosis was disseminated in all cases. By clinical, biological, microbiological histopathological means and response to treatment, tuberculosis was considered as: hematopoietic in all cases, hepatic (in 4/6), pleural (1/6), pulmonary (1/6). A favorable outcome of tuberculosis was observed in all cases. No death was observed. CONCLUSIONS: Tuberculosis was found in 8% of hair cell leukemia patients. In hairy cell leukemia, tuberculosis is characterized by few pulmonary symptoms and scarse microbiological documentation. In contrast, histopathology is very interesting to confirm diagnosis. Tuberculosis is in most cases disseminated and in particular hematopoietic diffusions is always present. In spite of existensive localization, the prognosis remains excellent and all patients can be cured. In our opinion, this good prognosis may be linked to the improvement of hairy cell leukemia treatment observed since the advent of interferon pentostatin and 2cdA.

Lexicalization errors in writing arabic numerals: a single-case study.

This paper presents a single-case study of a patient suffering from several impairments in number processing. The main focus of the paper is to describe and interpret the patient's errors in verbal to arabic transcoding. The errors were of the syntactical type and consisted of partial lexicalizations appearing mainly in response to items with Thousand in sum relationships and less frequently with Hundred in sum relationships. The Discussion section compares three models in their ability to account for the patient's dissociation. It was suggested that models such as that of McCloskey, Caramazza, and Basili (1985), postulating a semantic representation for numbers built up on a base-ten system, are unable to account for the patient's errors. By contrast, Power et al.'s perspective (Power & Longuet-Higgins, 1978; Power & Dal Martello, 1990), which posits a semantic representation of numbers reflecting the structure of the verbal numeral system, could provide an economical interpretation for the dissociation observed between the mastery of sum and product relationships. Similarly, the asemantic transcoding model developed by Deloche and Seron (1987) gives a valid account for the patient's profile.

Good predictive value of combined cytogenetic and molecular follow up in chronic myelogenous leukemia after non T-cell depleted allogeneic bone marrow transplantation: a report on 38 consecutive cases.

We prospectively performed repeated cytogenetic and PCR monitoring of residual disease in all cases Ph positive of chronic myeloid leukemia (CML) allografted with non T cell depleted marrow at our institution over a period of 8 years. Thirty eight patients who survived the immediate post transplant period could be analyzed (median of 3 cytogenetic analyses/patient, examining 100 mitoses, and 4 PCR analyses/patient). Seven of the 38 patients had a hematological relapse (which was extramedullary in one case) and one a purely cytogenetic relapse, possibly stabilised by interferon treatment. Within 6 months of transplant, Ph positive mitoses were seen in 2 patients, and positive PCR in most cases, without implying subsequent relapse. Six of the 32 patients analyzed cytogenetically more than 6 months post transplant had Ph positive mitoses on at least one occasion: 5 had a hematological relapse within 7 months of positive cytogenetic analysis, and the remaining patient, treated by interferon remained in purely cytogenetic relapse. (The extramedullary relapse was not preceded by a positive marrow karyotype). Eight of the 38 patients had positive PCR findings on at least one occasion more than 6 months post transplant. Seven relapsed (6 hematological relapses including the extramedullary relapse, and 1 cytogenetic relapse) after 3 to 20 months, but the remaining patient remained in CR 36 months later, with negative PCR. The 30 patients who never had positive PCR findings remained in CR. In this relatively large series of patients, we found a good correlation between PCR findings more than 6 months post transplant and remission or relapse status.(ABSTRACT TRUNCATED AT 250 WORDS)

Autologous bone marrow transplantation as consolidation therapy may prolong remission in newly diagnosed high-risk follicular lymphoma: a pilot study of 34 cases.

We evaluated early intensification followed by autologous bone marrow transplantation (ABMT) using marrow purged by mafosfamide in patients with high-risk low-grade follicular lymphoma (LGFL) reaching a status of minimal disease (MD). Thirty-four patients entered the program. All fulfilled at least one of the following criteria at diagnosis: a bulky tumor > 7 cm; three or more adenopathies > 3 cm; massive pleural or peritoneal effusion; massive splenomegaly; B symptoms; platelet count < 100 x 10(9)/l. Twenty-one patients had bone marrow involvement. Twenty-six patients received ACVBP, and eight CVP as front-line therapy. Twenty-one (62%) patients achieved MD status, 18 reached intensification. At 4 years, the time to treatment failure is 55 +/- 9%, and the probability of persisting remission is 75 +/- 11%. Comparison by intention to treat of the 26 patients who received ACVBP as front-line therapy to 14 historical high-risk LGFL similarly treated in our institution without intensification, showed better results for the intensified group (P = 0.04 for both probability of persisting remission and time to treatment failure). These results indicate that early intensification using marrow purged with mafosfamide is a therapeutic option which may bring benefit to patients with high-risk LGFL.

Quantitation of absolute regional myocardial perfusion using cine computed tomography.

OBJECTIVES: The purpose of this study was to develop and test a method for quantitation of regional myocardial perfusion using cine computed tomography. BACKGROUND: Cine computed tomography is a relatively new cardiac imaging technique with excellent temporal and spatial resolution. Application of this technique to the study of human coronary circulation could substantially broaden our knowledge of human cardiac pathophysiology. This goal has been previously approached with some success. However, no method to date has shown validated accuracy of regional perfusion measurements over the entire range of physiologically important flow states. METHODS: Eight anesthetized dogs underwent thoracotomy for instrumentation. They were then studied during baseline flow conditions, after coronary vasodilation with intravenous dipyridamole and after coronary stenosis or occlusion. Regional myocardial perfusion was assessed by cine computed tomography using a method that includes estimates for myocardial blood volume and rate of myocardial enhancement after an aortic root contrast medium infusion. Measurements made nearly simultaneously by the radioactive microsphere method served as a reference standard. RESULTS: A total of 32 perfusion conditions were studied with a range of 4 to 593 ml/min per 100 g. There was reasonable agreement between the two methods of measurement throughout the whole range of perfusion states: r = 0.97, regression slope 0.99, intercept 2 ml/min per 100 g. In zones not subserved by a stenosed or occluded artery, cine computed tomography accurately depicted perfusion homogeneity with a coefficient of variation of 13 +/- 1% (mean +/- SE) versus 11 +/- 1% for the microsphere method (p = NS). CONCLUSIONS: Cine computed tomography is capable of providing accurate, quantitative assessment of regional myocardial perfusion over a broad range of perfusion states. This method, if extended to the study of humans, could enhance the understanding of disorders of the coronary circulation in human cardiovascular disease states.

Images of numbers, or "When 98 is upper left and 6 sky blue".

Some people declare that they possess a personal visual representation of numbers: some automatically "see" the numbers they are confronted with in a precise location in a structured mental space, others "associate" specific colours with given numbers. Such visuo-spatial representations of numbers were first described by Galton in 1880 but have since received little attention from psychologists. It is the aim of this article to describe these mental representations and discuss their role in number processing. The authors first review Galton's observations, and then present their own. Finally, they discuss the relevance of these visuo-spatial representations in relation to contemporary debates on number representation and calculation.

Measurement of right ventricular volume using cine computed tomography.

Volume measurements of the right ventricle are clinically important, particularly in the assessment of congenital heart disease. The complex configuration of the right ventricular cavity, however, makes assessment of its volume difficult. Cine computed tomography (CT) permits depiction of cardiac anatomy in parallel, sequential, high-resolution tomographic images. To test whether cine CT would allow accurate, reproducible determination of right ventricular volumes, 11 excised, fixed canine hearts were scanned ex vivo. The endocardial contours of the right ventricular cavity were traced by two independent observers. The right ventricular cavity areas were measured in each image and right ventricular volume calculated by a Simpson's rule approximation. Actual right ventricular volume (range 24-86.5 mL) was measured by cavity fluid capacity. Right ventricular volumes derived from cine CT data correlated closely with actual volumes (R = .96, cine CT volume = 0.99 X [actual volume] + 0.2 mL). Interobserver correlation was excellent (R = .99). It is concluded that cine CT scanning permits accurate, reproducible determination of right ventricular volume ex vivo. This technique should be immediately applicable to the noninvasive evaluation of right ventricular function in children and adults.

Finite element analysis of myocardial diastolic function using three-dimensional echocardiographic reconstructions: application of a new method for study of acute ischemia in dogs.

The effect of acute myocardial ischemia on the myocardial elastic modulus has been a matter of controversy. To evaluate this question, diastolic elastic modulus was assessed by finite element analysis of left ventricular geometry using three-dimensional echocardiographic reconstructions and right and left ventricular pressure recordings. Elastic properties were estimated before and after coronary occlusion in 6 open-chest dogs. Elastic modulus values were derived by means of a computer program that determined the global elastic modulus that best predicted the diastolic changes in left ventricular geometry. In the finite element analysis after coronary occlusion, two analyses were performed: one utilizing the control elastic modulus for all segments of the left ventricle and one in which ischemic (dyskinetic) segments were assigned a higher elastic modulus. Results showed that the control elastic modulus was a poor predictor of diastolic left ventricular expansion after coronary occlusion. The finite element analysis in which the ischemic segments were assigned a higher elastic modulus better predicted ischemic diastolic wall motion patterns. Error values (difference between predicted and actual left ventricular segmental diastolic motion) were: control, 1.9 +/- 0.3 mm (mean +/- SD), ischemia, 2.9 +/- 0.5 mm, and 2.2 +/- 0.4 mm using the stiffer elastic modulus for ischemic segments. Error values were significantly higher (p less than 0.05) under ischemic conditions when the control elastic modulus was uniformly applied compared with control and ischemia with dyskinetic segments assigned a higher elastic modulus. From these data, it is concluded that the myocardial diastolic elastic modulus is increased by ischemia and that this approach may allow clinical assessment of intrinsic muscle stiffness.