Factors influencing sources cited by scientists: A case study for Cuba

A collection of 1316 articles authored by Cuban scientists and published in the period 1950 to 1983 was assembled. The 18 991 bibliographic references in these papers were examined to identify factors that might influence the sources cited by Cuban scientists over the entire period. Degree of collaboration, place of publication and subject matter were among the factors considered. The major objective was to study the effect that the change in political alignment of Cuba (from Western bloc to Eastern bloc influence) has had on the sources cited. It was found that citation to Eastern bloc countries has greatly increased in the period since Castro assumed power. However, no corresponding decline in citation to Western bloc countries can be discerned.     

Schematic change as a result of an intensive group-therapy day-treatment programs.

Treatment effects of a 12-wk day-treatment program were explored on measures of psychiatric distress (Brief Symptom Inventory) and maladaptive schemas (Schema Questionnaire Short Form; J. Young, 1990). 84 program completers (aged 22–57 yrs) showed significant pre–post change in psychiatric distress and on 3 of 15 schema: vulnerability to harm, social alienation, and defectiveness. Other schema did not change over the 12 wks. 15 waiting-list controls demonstrated no improvement in either distress level or in any of the 15 schema while waiting to be admitted to the program. Only 1 of the 15 schema, abandonment, predicted treatment outcome on changes in psychiatric distress level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ego development and chronic illness in adolescents.

To examine the effects of chronic illness on the psychological growth process known as ego development, scores were compared on the Sentence Completion Test for 36 teens (16 boys, 20 girls) with chronic illness and 50 teens (16 boys, 34 girls) without chronic illness. Their ages ranged from 13 to 21 years, with a mean of 17.4 years. Most were Black (37%) or Hispanic (41%) and lived in poor or working-class neighborhoods. When age, sex, and Peabody Picture Vocabulary Test (PPVT) scores were controlled in multiple regression analyses, no direct association between ego development stage and presence of chronic illness, severity of illness, age at onset, or duration of illness was found. Analysis of the chronically ill group alone revealed a significant PPVT?×?Severity interaction, indicating that ego development in chronically ill teens is lower when illness is more severe and verbal IQ is higher. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mathematical Modeling of Encapsulated Buffer Performance in Sand Columns

A one-dimensional mathematical model was developed to simulate pH control using an encapsulated phosphate buffer during denitrification in a sand column. The parameters required for the model were obtained from direct physical measurement, from a tracer study to characterize the dispersion coefficient in the column, and from batch experiments designed to obtain an empirical expression describing the variation of the first-order rate constant for the encapsulated buffer core release with pH. First-order kinetic constants describing the rates of denitrification and ethanol biodegradation were obtained by fitting the model to column runs without the encapsulated buffer. With these parameters, the model was subsequently used to predict the performance of column runs containing the encapsulated buffer. Since denitrification was essentially complete in the sand columns, an increase in the effluent pH was observed. This pH increase was counteracted by the controlled release of the acidic core of the encapsulated buffers added in the columns. The model reasonably predicted the release of the encapsulated buffer core and the performance of the encapsulated buffer for controlling pH in the column.     

Antivitamins for Medicinal Applications

Antivitamins represent a broad class of compounds that counteract the essential effects of vitamins. The symptoms triggered by such antinutritional factors resemble those of vitamin deficiencies, but can be successfully reversed by treating patients with the intact vitamin. Despite being undesirable for healthy organisms, the toxicities of these compounds present considerable interest for biological and medicinal purposes. Indeed, antivitamins played fundamental roles in the development of pioneering antibiotic and antiproliferative drugs, such as prontosil and aminopterin. Their development and optimisation were made possible by the study, throughout the 20th century, of the vitamins' and antivitamins' functions in metabolic processes. However, even with this thorough knowledge, commercialised antivitamin‐based drugs are still nowadays limited to antagonists of vitamins B₉ and K. The antivitamin field thus still needs to be explored more intensely, in view of the outstanding therapeutic success exhibited by several antivitamin‐based medicines. Here we summarise historical achievements and discuss critically recent developments, opportunities and potential limitations of the antivitamin approach, with a special focus on antivitamins K, B₉ and B₁₂.     

Specific factors affecting lead uptake by food from cooking water

Following earlier work, detailed studies have been carried out on the lead uptake of individual foods from soft and hard water containing various amounts of lead. Experiments have also been made to determine whether solutions of lead nitrate in distilled water simulate the behaviour of water containing naturally present lead. The effect of length of cooking time, weight/volume ratio and salt addition have been studied, as well as the depostion of lead on to cooking vessels. In general, green vegetables, carrots, rice and spaghetti were found to take up more lead than do other foods. The difference in uptake observed between hard and soft waters varied according to the particular food being studied. Uptake from lead nitrate solutions showed a very similar pattern to uptake from hard water containing naturally present lead. Equilibrium was reached after only 5 min cooking for cabbage and spaghetti. Varying the solid/volume ratio for cabbage affected the uptake of lead from water, but the addition of sodium chloride or sodium bicarbonate had little effect on lead uptake. There was no sign of saturation in uptake of lead by cabbage from solutions of 11 mg litre^?1 lead as lead nitrate. Deposition of lead occurred on both aluminium and glass saucepans, and cleaning was more effective in removing lead from glass saucepans. Results obtained from the analysis of diets in a small population at Ayr confirmed those obtained previously by laboratory experiments.     

Congruence/genuineness.

Congruence or genuineness is a relational quality that has been highly prized throughout the history of psychotherapy, but of diminished research interest in recent years. In this article, we define and provide examples of this attribute of the therapy relationship and present an original meta-analytic review of the empirical literature showing its relation to improvement. Analysis of 16 studies (k), representing 863 patients (N), resulted in a weighted aggregate ES (r) of .24 (p = .003; 95% CI = .12 to .36). Moderators of the association between congruence and treatment outcome are examined, and limitations of the extant research are discussed as well. In closing, we advance several therapist practices that are likely to foster congruence and thus improve psychotherapy outcomes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The effect of anticipatory strategies on the first day of smoking cessation.

The authors tested a model hypothesizing the predictors and the effects of anticipatory strategy use on the 1st day of smoking cessation using data from 63 participants in an ecological momentary assessment study of smoking cessation. Remaining abstinent on the 1st day of cessation was not associated with mean level of urges to smoke during tempting situations but was associated with anticipatory strategy use, which accounted for 18% of the variance. Getting rid of cigarettes contributed the most to this effect (β?=?-.397). Getting rid of cigarettes was itself predicted by 2 variables, lower nicotine dependence (β?=?-.264) and attending a formal smoking cessation class (β?=?.305), which accounted for 15% of its variance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An upper-shelf fracture toughness master curve for ferritic steels

When assessing the resistance of a steel structure to failure under load, fracture toughness is a key input variable. Since it is usually not possible to establish a priori if the anticipated service temperature (or temperatures) is in the fracture mode transition or on the upper shelf, it is useful to know the temperature dependence of fracture toughness in both the transition and on the upper shelf. In the transition, the master curve proposed by Wallin defines both the variation of the median value of fracture toughness with temperature and the scatter of fracture toughness about this median value. However, Wallin's master curve does not quantify fracture toughness on the upper shelf. In this paper we assemble a database of upper shelf fracture toughness data (J_Ic) for ferritic steels. These data demonstrate that the temperature dependence of upper J_Ic is consistent for all ferritic steels contained in the database and has the same form as the temperature dependence of the flow strength anticipated from dislocation mechanics considerations. This similarity between the temperature dependence of flow strength and the temperature dependence of J_Ic is physically expected because both directly depend upon the energy required for dislocation mobility in the ferrite matrix. Both the empirically derived model and the physical basis for the model are described.     

Development of the First Oral Bioprecursors of Bis‐alkylguanidine Antimalarial Drugs

Plasmodium falciparum is responsible of the most severe form of malaria, and new targets and novel chemotherapeutic scaffolds are needed to fight emerging multidrug‐resistant strains of this parasite. Bis‐alkylguanidines have been designed to mimic choline, resulting in the inhibition of plasmodial de novo phosphatidylcholine biosynthesis. Despite potent in vitro antiplasmodial and in vivo antimalarial activities, a major drawback of these compounds for further clinical development is their low oral bioavailability. To solve this issue, various modulations were performed on bis‐alkylguanidines. The introduction of N‐disubstituents on the guanidino motif improved both in vitro and in vivo activities. On the other hand, in vivo pharmacological evaluation in a mouse model showed that the N‐hydroxylated derivatives constitute the first oral bioprecursors in bis‐alkylguanidine series. This study paves the way for bis‐alkylguanidine‐based oral antimalarial agents targeting plasmodial phospholipid metabolism.