Significant Mexican research in the health sciences: A bibliometric analysis

In the 1970s Mexico started to consolidate its S&T system by training human resources and actively preventing brain drain, mainly by motivating researchers through economic incentives. Considering Bradford"s Law, an analysis of significant Mexican research in the health sciences, i.e., papers published in journals with a high-impact factor which grant a degree of credibility and importance was carried out. Significant papers produced in Mexico show a measure of the country"s productivity, and these papers" citations measure the country"s international impact.     

Thin-Layer Chromatography Assessing Feeding Stimulation by Labial Gland Secretion Compared to Synthetic Chemicals in the Subterranean Termite Reticulitermes santonensis

The labial gland of the French subterranean termite Reticulitermes santonensis De Feytaud contains a polar, heat-resistent, and persistent chemical signal that is released onto the food during food exploitation and stimulates feeding in nestmates. Separation of the labial gland secretion by thin-layer chromatography on cellulose plates revealed that the secretion contains components with reducing and amino groups. In feeding bioassays conducted on the cellulose plate after TLC, termites preferred the area between Rf 0.46 and 0.88 (biologically active zone) for feeding, indicating the location of the feeding-stimulating signal. Thirty-five synthetic chemicals with similar chemical properties as the feeding-stimulating signal were analyzed with TLC. None of them covered the biologically active zone. Therefore, all chemical classes tested, such as sugars, amino acids, and salts, are unlikely as possible sources for the signal structure. In feeding choice tests with synthetic chemicals, termites showed clear feeding preference only for sugarlike components with physiologically excessive concentrations of 10 mmol and 100 mmol. Amino acids induced only light feeding preference. The intensity of feeding stimulation by the natural signal from the labial gland as compared to synthetic phagostimulants is discussed.     

Composition of Distributed Software with Algon — Concepts and Possibilities

The perceived advantages of distributed systems, such as increased reliability and availability, are offset by the increased complexity of developing such applications. The developers of distributed applications have to both understand the core functionality of the application, and to cater for the mechanisms of distribution. Distribution brings with it issues of mutual exclusion, termination and deadlock which are addressed differently in a centralised system. We propose using separation of concerns. to control any additional complexity thus introduced. We identify specifically the well known distributed algorithms which solve distributed mutual exclusion and so on, and provide a framework whereby they can be injected into an existing system. The framework is called Algon, and consists of the algorithms, various wrappers and interfaces in Java, and sample schedulers which are needed to handle communication between the now distributed processes. Algon does not supply middleware, and the intention is that any middleware such as RMI, CORBA or .NET can be used. The novelty of Algon is that developers are not expected to understand or implement the distributed algorithms themselves. Moreover Algon provides the developer with a choice of pre-coded and tested algorithms with different performance characteristics. This paper gives an outline of the Algon approach, and provides a pattern specification for the separation of these algorithms from the core functionality of a distributed system.     

A simply constructed heating stage for the scanning electron microscope

An easily constructed heating stage has been designed for a Cambridge Scientific Instruments' Stereoscan Scanning Electron Microscope. This heating stage is capable of reaching temperatures of at least 1273 K. The stage is a simple design which can easily be built from non-magnetic stainless steel and a natural stone consisting mainly of pyrophyllite. All heat shielding is made from these materials without the need for any liquid coolant surrounding the stage. The use of this heating stage as an instrument for the study of morphological changes during heating processes up to 1273 K is described briefly.     

Developmental analysis of the conditional reasoning abilities of primary-grade children.

Administered a conditional reasoning test to 36 1st-3rd graders. Each child was tested individually with a concrete and a verbal presentation of the test items. After his response to each test item, the child was asked to explain the reason for his response. An analysis of variance of the number of correct judgments showed significant main effects for Grade Level, Mode of Presentation, and Principle, and a significant Grade Level * Principle interaction. An examination of the explanations for correct judgments revealed that children's problem-solving behaviors varied according to both testing session and principle of inference. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simultaneous determination of nitrogen,phosphorus and potassium in plant material by automatic methods

Existing methods, using autoanalyser and flame photometer equipment have been adapted and combined. Using one acid digest of plant material, three determinations, for nitrogen, phosphorus and potassiums are carried out simultaneously and automatically. Seventy samples per hour can be assayed. Time and mental fatigue in calculating results are reduced by using a two-way table produced as a computer print-out.     

Cognitive psychology meets the national survey.

Describes collaborative efforts that have been initiated between cognitive psychologists and survey researchers, noting that attempts to foster a dialog between the 2 disciplines have been made only recently. Topics of discussion include existing surveys as sources of information on cognitive processes, new surveys to develop norms for cognitive abilities, and improvement of survey methods. Ways in which beneficial work may be conducted in the interdisciplinary area between cognitive psychology and national survey research are also considered. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nonvolition, expectancies, and hypnotic rapport.

Prior to hypnosis, 49 Ss were informed either that hypnotizable Ss can resist motoric suggestions or that such control does not characterize good hypnotic Ss. During hypnosis, susceptible and simulating Ss (as determined by a 10-point version of the Harvard Group Scale of Hypnotic Susceptibility–Form A) received countersuggestions involving inhibiting suggestion-related movements. Susceptible Ss' responses were sensitive to prehypnotic normative information. There was a corresponding tendency for reports of involuntariness to be sensitive to the expectancy manipulation. Ss were able to feel deeply hypnotized and to rate themselves as good Ss yet concomitantly experience themselves as in control over their actions when normative information supported this attribution. Reports of suggestion-related sensations were associated with movements in response to countersuggestion. Simulators were unable to fake susceptibles' reports of sensations and involuntariness. However, for all Ss, movements paralleled expectancies about appropriate response, supporting the hypothesis that involuntary experiences are sensitive to the broad expectational context and are mediated by active cognitive processes. Rapport with the hypnotist was also a factor in resolving hypnotic conflict. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Training learning strategies with computer-aided cooperative learning

This paper describes the combination of two potent training technologies (computer-based instruction and cooperative learning) into a system called computer-aided cooperative learning (CACL) and the use of CACL to train students in a general learning strategy. This six-steps strategy involves setting a task-appropriate mood, reading for general understanding, recall as much of the material as possible, detecting errors and omissions, elaborating upon the material to make it more memorable and reviewing. CACL capitalizes on the strengths and overcomes some of the weaknesses of each of the constituent technologies. The resulting program is described and some data demonstrating its effectiveness is presented. Students using CACL recalled more material from each of two passages studied individually than did students who did not use CACL. CACL appears to be a promising technology for the delivery of learning strategies. Future research and development efforts should examine CACL's usefulness to the training of more sophisticated learning strategies.