Existence of a mannitol hydrate during freeze-drying and practical implications

We report thermal and crystallographic evidence for a previously unknown mannitol hydrate that is formed in the process of freeze-drying. The mannitol hydrate was produced by freeze-drying pure mannitol solutions (1-4% w/v) using the following cycle: (1) equilibration at -5 degreesC for 1 h; (2) freezing at -40 degreesC; (3) primary drying at -10 degreesC for 15 h; and (4) secondary drying at 10 degreesC for 2 h and then 25 degreesC for 5 h. This crystal form was also observed upon freeze-drying in the presence of sorbitol (1% w/v). The mannitol hydrate showed a distinct X-ray powder diffraction pattern, low melting point, and steplike desolvation behavior that is characteristic of crystalline hydrates. The mannitol hydrate was found to be metastable, converting to anhydrous polymorphs of mannitol upon heating and exposure to moisture. The amount of the mannitol hydrate varied significantly from vial to vial, even within the same batch. The formation of mannitol hydrate has several potential consequences: (1) reduced drying rate; (2) redistribution of the residual hydrate water during accelerated storage to the amorphous drug; and (3) vial-to-vial variation of the moisture level.     

The Canadian National Breast Screening Study: a Canadian critique

The Canadian National Breast Screening Study (CNBSS) was the first study designed to determine the efficacy of screening for breast carcinoma in women 40-49 years old. Women were randomized to undergo either annual mammography and physical examination or usual care after an initial physical examination [1]. Women 50-59 years old were randomized to undergo either annual mammography and physical examination or annual physical examination only [2]. This study, published by epidemiologists on the efficacy of a radiologic examination, therefore, invites evaluation by radiologists.     

Theoretical and practical implications of calcitonin therapy in gastroduodenal ulcer

Calcitonin (CT) inhibits basal and pentagastrin stimulated gastric acid and pepsin secretion by 60 to 70% when CT is infused over a short period of time. Vagal and histamine-mediated stimulations are less diminished. A long-term infusion of CT inhibits persitently basal and pentagastrin-stimulated acid and pepsin secretion over more than 24 hours in patients with duodenal ulcer, stress bleeding and Zollinger-Ellison-Syndrome. To date, the therapeutic efficiency of CT in gastroduodenal bleeding has not been evaluated in a controlled trial. CT inhibits gastric secretion also after oral application. In an endoscopically controlled double blind trial we were not able to demonstrate a significant benefit of oral CT in patients with gastric ulcer. In ulcer bleeding CT does not apear reasonable in comparison with histamine-H2-receptor antagonists which apparently is more efficient and less costly.     

The safety of early postpartum discharge: a review and critique

OBJECTIVE: To determine the effect of early postpartum discharge (less than 48 hours after vaginal birth or 96 hours after cesarean delivery) on maternal and neonatal complications, maternal concerns, patient satisfaction, and cost savings. DATA SOURCES: We performed a MEDLINE search of English-language journals for pertinent articles published from 1966 through January 1997. We also reviewed reference lists in all the articles retrieved in the search as well as those of major obstetric texts. METHODS OF STUDY SELECTION: We included all studies describing early postpartum discharge. TABULATION, INTEGRATION, AND RESULTS: Studies included five randomized controlled trials, ten cohort studies, one case-control study, and 12 case-series reports. We classified the data using the rating system of the U.S. Preventive Services Task Force. We calculated relative risks and 95% confidence intervals for maternal and neonatal readmission and outpatient treatment after early postpartum discharge. Most studies did not show an increase in maternal or neonatal morbidity after early discharge. The five randomized controlled studies did not meet criteria for properly designed trials. Most evidence consists of cohort studies and case-series (class II-2 and III evidence) of highly selected patients with extensive supplemental antepartum and postpartum care and education. CONCLUSION: The current data do not support or condemn widespread use of early postpartum discharge in the general population (class C recommendation). Early postpartum discharge appears safe for carefully selected, consenting patients. Whether these data can be extrapolated to the general population of pregnant women remains unknown.     

Interrelations of social support measures: Theoretical and practical implications.

To obtain a clearer picture of what constitutes social support, we conducted three studies to compare measures of different conceptions of social support. Relations of these instruments to various personality measures were also investigated. Subdividing the construct into discrete functions did not add to the sensitivity of the indices. Measures of received support and support networks were not strongly related to most of the perceived available support measures. Interview and questionnaire approaches were similar in the information they evoked about close supportive relationships. The results suggest that measures of perceived available support, regardless of the way the instruments attempt to break down the construct, generally assess the extent to which an individual is accepted, loved, and involved in relationships in which communication is open. Psychometric characteristics of the measures were associated with differential sensitivity over the range of supportive relationships. The theoretical implications of the findings are discussed with emphasis on the common core underlying social support indices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theoretical and practical implications of creep curve shape analyses for 8090

For tensile stresses applied parallel to the elongated grain structure of the aluminum alloy, 8090, the creep and creep fracture properties are discussed in relation to the changes in precipitate dispersion and transgranular failure mode observed over stress ranges giving creep lives up to 6000 hours at 373 to 463 K. Specifically, a transition from growth of cracks nucleating on the short transverse boundaries to neck formation occurs when the deformation resistance is reduced progressively by precipitate coarsening as the test duration increases at 427 K and above. All features of the recorded behavior patterns are then explained in terms of the processes governing strain accumulation and damage development by using the ϑ methodology to quantify the systematic variations in creep curve shape with changing stress and temperature.     

Behavioral treatment of childhood obesity: Theoretical and practical implications.

The impressive 10-yr success of behavioral treatment of childhood obesity stands in marked contrast to the disappointing long-term results obtained with obese adults. It may be easier to teach children healthy eating and activity habits. Parents also regulate access to food, thereby reducing the importance of self-control. Whether treatment of childhood obesity affects the later development of an eating disorder is a question that calls for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Juror underutilization of eyewitness nonidentifications: Theoretical and practical implications.

Tested the impact of 2 types of nonidentification information (eyewitness testimony and fingerprint evidence) on the perception of guilt. 216 undergraduates simulating the role of jurors were shown cases in which there was (a) a single eyewitness identification, (b) a single eyewitness nonidentification, (c) a single eyewitness control, (d) contradictory testimony, (e) 2 eyewitness identifications, or (f) 2 eyewitness nonidentifications. Three levels of fingerprint information (identification, nonidentification, and control) were factorially combined with the eyewitness factor. Results show that nonidentifications had less impact on perceptions of guilt than identification for both eyewitness testimony and fingerprint evidence. Findings are explained in terms of the general tendency for negative information to carry greater weight than positive information. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fractionation of serum cholesterol: a critique

A procedure for fractionation of serum cholesterol is developed by employing digitonin for the precipitation of free cholesterol in isopropanol. This method is based on the ferric acetate color reaction which is unaffected by traces of digitonin. It is influenced only negligibly by the presence of stanols in serum and is shown to be equally chromogenic with respect to both free and ester forms of cholesterol. The proposed procedure shows a three-fold improvement in precision (3.1 percent coefficient of variation [CV]) compared to that of the procedure by Leffler and McDougald (10.5 percent C.V.) which is based on the ferric chloride color reaction. The proposed free cholestrol procedure showed a mean recovery of 99.5% percent (98.1 to 102.5 percent) when cholesterol in 40 to 200 mg per dl concentrations was added to serum. The analytical performance of the proposed fractionation of serum cholesterol is critically reviewed with respect to its potential application in the diagnosis of liver diseases and in basic or experimental research.     

The construction of feminist pedagogy in nursing education: a preliminary critique

This project was completed in response to articles that have appeared in nursing journals calling for feminist pedagogy. The object of inquiry is the current discourse of feminist pedagogy. In critiquing the discourse, Foucault's notion of "regime of truth" was used as a tool for analysis. It is the author's contention that feminist pedagogy, as currently constructed in nursing education, has likened Freire's notion of liberatory education with feminist scholarship. Feminist scholarship has taken a subordinate role to stories of classroom processes. Many so-called feminist strategies are, in reality, progressive educational strategies adorned with seductive language. Adopting a questioning stance, rather than merely proclaiming that "all is bliss" in the feminist classroom, would benefit all who are involved in the construction of feminist pedagogy. If nursing education is to seriously engage with feminist scholarship, as the author believes it must do, then it must not play a secondary role in feminist pedagogy.     

Alternative views of Bashore and Rapp's (1993) alternatives to traditional polygraphy: A critique.

Rosenfeld critiques an article on deception detection by T. T. Bashore and P. P. Rapp (1993) that appeared earlier in this journal. These authors reviewed the field of traditional polygraphy, coming to the conclusion that traditional autonomic nervous system (ANS) indices of psychological events thought to be directly or indirectly involved in deception-related processes have limitations that might not apply to the representation of these processes in brain activity. Rosenfeld criticizes what he sees as a relatively one-sided presentation of traditional ANS polygraphy by Bashore and Rapp. He also reconsiders Bashore and Rapp's preference for brain activity indices over ANS indices in deception detection. Finally, he attempts to correct Bashore and Rapp's inaccurate and incomplete review of approaches to deception detection based on brain activity measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A survey on quantitative microdialysis: theoretical models and practical implications

The relationship between the transthylakoid pH-gradient, delta pH, and the velocity of photophosphorylation, Vp, in thylakoid membranes from spinach was investigated using the local anesthetic amine procaine as inhibitor of delta pH. When delta pH was driven by Photosystem (PS) II+I-dependent electron flow, passing through the cytochrome b6/f complex, inhibition by procaine was accompanied by an increase of ATP formation. It appeared that procaine allowed for values of Vp similar to those in controls (without procaine) at a significantly lower delta pH than in the controls. In contrast, when delta pH was driven by cyclic electron flow around PS I or by PS-II+I-dependent electron flow via a bypass around the cytochrome b6/f complex, or by PS II alone, procaine simultaneously caused an inhibition of delta pH and a decrease of ATP formation. Inhibition of delta pH by procaine did not induce an electrical membrane potential gradient that otherwise may have energetically compensated for the observed decline of delta pH. The electron flow capacity was unaffected by procaine. However, inhibition of delta pH did not significantly relax pH-dependent control of electron flux. Procaine accelerated ATP hydrolysis by pre-activated thylakoid ATPase to rates which were observed in the presence of uncouplers and had no direct effect on the activation state of the ATPase. The shift in the relationship between delta pH and Vp towards lower delta pH persisted in thermodynamic equilibrium between the phosphorylation potential and delta pH. The data indicated that the unconventional effect of procaine on photophosphorylation may be related to effects on proton translocation at the cytochrome b6/f complex and that a localized protonic coupling may occur between cytochrome b6/f and thylakoid-ATP-synthase complexes.     

How to critique a published article.

Few replies get published. Many that do get published could be more effective. A reply can be effective only if it is published, readable, and credible. This article suggests guidelines for writing good replies. The guidelines begin with things to keep in mind—for example, that you might be wrong—and things to do before you begin to write. The latter include considering not responding, considering alternative viewpoints, and distancing yourself from the task. Things to do while writing include using the principle of charity, avoiding ad hominem and emotionally laden arguments, and keeping the rebuttal short. After completing the first draft, you should put it aside for awhile as well as get a second opinion. A good reply complements rather than discredits the argument of the target author. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eysenck's tendermindedness dimension: a critique.

An evaluation of Eysenck's research on his tough-mindedness-tender-mindedness factor indicates that this dimension is based not upon fact, but rather rests on "… miscalculations and a disregard for a significant portion of his data. It conceals rather than reveals the attitudinal differences existing among political groups." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why psychology is/is not traditional science: The self-referential bases of psychological research and theory.

The hyperspecialization, fragmentation, curious faddishness of major research topics, and perceived incommensurabilities of theories and methods in contemporary psychology are often seen as a discipline-specific crisis over our status as a single, identifiable "science." These features can, however, be understood as the contemporary expression of early discussions by Giambattista Vico and Wilhelm Dilthey on the inherently self-referential basis of psychology, based on its emergent, even paradoxical, combination of the methods of physical science with the underlying themes of the humanities. This defining tension between "explanation" and "understanding" can account for these features of ostensible disunity, along with the unique importance of "ecological validity" in empirical methodology and the roots of theory in largely implicit world-views and the matrix of ordinary language, quite different from the explicit role of law in physical science. Current neuroscience, although exemplifying "high consensus, rapid discovery" physical science, also illustrates this broader "hermeneutic" perspective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)