Concanavalin A-Binding Enzymes of Crotalus scutulatus scutulatus Venom

Crotalus scutulatus scutulatus crude venom was separated into two fractions by Concanavalin A Sepharose 4B affinity chromatography. The proteins binding to Con A exhibited phosphomonoesterase (orthophosphoric monoester phosphohydrolase EC 3.1.3.2), phosphodiesterase, 5\u27-nucleotidase (5\u27-ribonucleotide phosphohydrolase EC 3.1.3.5), phospholipase A(phosphatidate 2-acylhydrolase EC 3.1.1 .4), hyaluronidase (hyaluronate glycanohydrolase EC 3.2.1 d), N-benzoyl-L-arginine ethyl esterase, p-toluenesulfonyl-L-arginine methyl esterase, L-amino acid oxidase (L-amino acid: 02 oxidoreductase [deaminating] EC 1.4.3.2), and caseinolytic activities. Thrombin-like and NAD nucleosidase (5\u27-ribonucleotide phosphohydrolase EC 3.1.3.5) activities were not observed. The crude venom and the fraction containing the glycoproteins which bound to Con A were fractionated by DEAE Sephadex A-50 ion exchange chromatography. Each of these samples yielded fractions having caseinolytic activities

Concanavalin A-Nonbinding Enzymes of Crotalus scutulatus scutulatus Venom

Crotalus scutulatus scutulatus crude venom was separated into two fractions by Concanavalin A Sepharose 4B affinity chromatography. The Concanavalin A-nonbinding fraction (F-l) exhibited phosphomonoesterase (orthophosphoric monoester phosphohydrolase EC 3.1 .3.2), phosphodiesterase, 5 \u27-nucleotidase (5 \u27-ribonucleotide phosphohydrolase EC 3.1.3.5), phospholipase A (phosphatidate 2-acylhydrolase EC 3.1.1.4), hyaluronidase (hyaluronate glycanohydrolase EC 3.2.1.d), N-benzoyl-Larginine ethyl esterase, p-toluenesulfonyl-L-arginine methyl esterase, L-amino acid oxidase (L-amino acid: O2 oxidoreductase [deaminating] EC 1.4.3.2), and caseinolytic activities. Thrombin-like and NAD nucleosidase (5 \u27-ribonudeotide phosphohydrolase EC 3.1.3.5) activities were not observed. DEAE Sephadex A-50 ion exchange chromatography by two stage elution of F-l yielded several fractions having proteinase activities. Proteinase activity was observed in the latter fractions of the first elution and in the fractions of the second elution

Second harmonic beam analysis, a sensitive technique to determine the duration of single ultrashort laser pulses

The second harmonic beam generated in a noncollinear arrangement allows the observation of the autocorrelation functio: A compact optical beam splitter and imaging system eliminates alignment problems. Single pulses of 1 ps duration and approximately 10−8 joule energy are readily observed using an optical multichannel analyser

Questioning and organization studies

This essay identifies a cleavage in the organisation literature that separates ‘questions’ and ‘questioning’ at a very fundamental philosophical level. On the one hand, the objective notion of ‘questions’ has already been well addressed within organization studies, evident in how scholars have scrutinized questions as objects of analysis; for example, paying close attention to the forms and functions of questions as instruments of research. More recently, the linguistic turn within the social sciences has influenced how organization studies researchers have considered organizations as discursive entities, with debate extending to the discursive nature of ‘questions’. On the other hand, the process of ‘questioning’ remains under-researched. From one perspective, questioning the process of questioning is challenging, but, as we submit, this is precisely where American pragmatism can be helpful. As we explore in this essay, the forward-looking quality of pragmatist inquiry is what motors the process of questioning. Our pragmatist-inflected argument is that questioning does not have to always serve critique and position building in the organization studies field. Rather, questioning out of curiosity can build new dialogue and open up new methodological avenues. This may help change the habitual ways in which we explore ideas, problems and situations in organization studies as well as lead to more democratic forms of organizing. Crucially, in this essay we are not looking for ultimate ‘answers’; rather we hope to excite discussion about questioning by giving prominence to something that is so ubiquitous and taken-for-granted as to be invisible to many of us as an object of inquiry

Deweyan tools for inquiry and the epistemological context of critical pedagogy

This article develops the notion of resistance as articulated in the literature of critical pedagogy as being both culturally sponsored and cognitively manifested. To do so, the authors draw upon John Dewey\u27s conception of tools for inquiry. Dewey provides a way to conceptualize student resistance not as a form of willful disputation, but instead as a function of socialization into cultural models of thought that actively truncate inquiry. In other words, resistance can be construed as the cognitive and emotive dimensions of the ongoing failure of institutions to provide ideas that help individuals both recognize social problems and imagine possible solutions. Focusing on Dewey\u27s epistemological framework, specifically tools for inquiry, provides a way to grasp this problem. It also affords some innovative solutions; for instance, it helps conceive of possible links between the regular curriculum and the study of specific social justice issues, a relationship that is often under-examined. The aims of critical pedagogy depend upon students developing dexterity with the conceptual tools they use to make meaning of the evidence they confront; these are background skills that the regular curriculum can be made to serve even outside social justice-focused curricula. Furthermore, the article concludes that because such inquiry involves the exploration and potential revision of students\u27 world-ordering beliefs, developing flexibility in how one thinks may be better achieved within academic subjects and topics that are not so intimately connected to students\u27 current social lives, especially where students may be directly implicated

Scapegoat: John Dewey and the character education crisis

Many conservatives, including some conservative scholars, blame the ideas and influence of John Dewey for what has frequently been called a crisis of character, a catastrophic decline in moral behavior in the schools and society of North America. Dewey’s critics claim that he is responsible for the undermining of the kinds of instruction that could lead to the development of character and the strengthening of the will, and that his educational philosophy and example exert a ubiquitous and disastrous influence on students’ conceptions of moral behavior. This article sets forth the views of some of these critics and juxtaposes them with what Dewey actually believed and wrote regarding character education. The juxtaposition demonstrates that Dewey neither called for nor exemplified the kinds of character-eroding pedagogy his critics accuse him of championing; in addition, this paper highlights the ways in which Dewey argued consistently and convincingly that the pedagogical approaches advocated by his critics are the real culprits in the decline of character and moral education

Cue-Induced Dopamine Release Predicts Cocaine Preference: Positron Emission Tomography Studies in Freely Moving Rodents

Positron emission tomography studies in drug-addicted patients have shown that exposure to drug-related cues increases striatal dopamine, which displaces binding of the D2 ligand, [11C]-raclopride. However, it is not known if animals will also show cue-induced displacement of [11C]-raclopride binding. In this study, we use [11C]-raclopride imaging in awake rodents to capture cue-induced changes in dopamine release associated with the conditioned place preference model of drug craving. Ten animals were conditioned to receive cocaine in a contextually distinct environment from where they received saline. Following conditioning, each animal was tested for preference and then received two separate [11C]-raclopride scans. For each scan, animals were confined to the cocaine and/or the saline-paired environment for the first 25 min of uptake, after which they were anesthetized and scanned. [11C]-raclopride uptake in the saline-paired environment served as a within-animal control for uptake in the cocaine-paired environment. Cocaine produced a significant place preference (p = 0.004) and exposure to the cocaine-paired environment decreased [11C]-raclopride binding relative to the saline-paired environment in both the dorsal (20%; p < 0.002) and ventral striatum (22%; p < 0.05). The change in [11C]-raclopride binding correlated with preference in the ventral striatum (R2 = −0.87; p = 0.003). In this region, animals who showed little or no preference exhibited little or no change in [11C]-raclopride binding in the cocaine-paired environment. This noninvasive procedure of monitoring neurochemical events in freely moving, behaving animals advances preclinical molecular imaging by interrogating the degree to which animal models reflect the human condition on multiple dimensions, both biological and behavioral.Chemistry and Chemical Biolog