Determination of the Structural Parameters of Local Ordering in Oxide Melts and Glasses from X-ray Diffraction Data

The application of the pair function method coupled with the interference function refining technique is discussed as a procedure for obtaining quantitative estimation of the coordination numbers and interatomic distances in the near neighbor region of oxide melts and glasses. The usefulness of this technique is demonstrated by applying the procedure to the structural analysis of typical rock forming silicate melts

Revisiting cannabinoid receptor 2 expression and function in murine retina.

The cannabinoid receptor CB2 plays a significant role in the regulation of immune function whereas neuronal expression remains a subject of contention. Multiple studies have described CB2 in retina and a recent study showed that CB2 deletion altered retinal visual processing. We revisited CB2 expression using immunohistochemistry and a recently developed CB2-eGFP reporter mouse. We examined the consequence of acute vs. prolonged CB2 deactivation on the electroretinogram (ERG) responses. We also examined lipidomics in CB2 knockout mice and potential changes in microglia using Scholl analysis. Consistent with a published report, in CB2 receptor knockout mice see an increased ERG scotopic a-wave, as well as stronger responses in dark adapted cone-driven ON bipolar cells and, to a lesser extent cone-driven ON bipolar cells early in light adaptation. Significantly, however, acute block with CB2 antagonist, AM630, did not mimic the results observed in the CB2 knockout mice whereas chronic (7 days) block did. Immunohistochemical studies show no CB2 in retina under non-pathological conditions, even with published antibodies. Retinal CB2–eGFP reporter signal is minimal under baseline conditions but upregulated by intraocular injection of either LPS or carrageenan. CB2 knockout mice see modest declines in a broad spectrum of cannabinoid-related lipids. The numbers and morphology of microglia were unaltered. In summary minimal CB2 expression is seen in healthy retina. CB2 appears to be upregulated under pathological conditions. Previously reported functional consequences of CB2 deletion are an adaptive response to prolonged blockade of these receptors. CB2 therefore impacts retinal signaling but perhaps in an indirect, potentially extra-ocular fashion.post-print8285 K

Cannabis in medicine: a national educational needs assessment among Canadian physicians

BACKGROUND: There is increasing global awareness and interest in the use of cannabis for therapeutic purposes (CTP). It is clear that health care professionals need to be involved in these decisions, but often lack the education needed to engage in informed discussions with patients. This study was conducted to determine the educational needs of Canadian physicians regarding CTP. METHODS: A national needs assessment survey was developed based on previous survey tools. The survey was approved by the Research Ethics Board of the McGill University Health Centre Research Institute and was provided online using LimeSurvey®. Several national physician organizations and medical education organizations informed their members of the survey. The target audience was Canadian physicians. We sought to identify and rank using 5-point Likert scales the most common factors involved in decision making about using CTP in the following categories: knowledge, experience, attitudes, and barriers. Preferred educational approaches and physician demographics were collected. Gap analysis was conducted to determine the magnitude and importance of differences between perceived and desired knowledge on all decision factors. RESULTS: Four hundred and twenty six responses were received, and physician responses were distributed across Canada consistent with national physician distribution. The most desired knowledge concerned “potential risks of using CTP” and “safety, warning signs and precautions for patients using CTP”. The largest gap between perceived current and desired knowledge levels was “dosing” and “the development of treatment plans”. CONCLUSIONS: We have identified several key educational needs among Canadian physicians regarding CTP. These data can be used to develop resources and educational programs to support clinicians in this area, as well as to guide further research to inform these gaps

Cannabinoids Modulate Neuronal Activity and Cancer by CB1 and CB2 Receptor-Independent Mechanisms

Cannabinoids include the active constituents of Cannabis or are molecules that mimic the structure and/or function of these Cannabis-derived molecules. Cannabinoids produce many of their cellular and organ system effects by interacting with the well-characterized CB1 and CB2 receptors. However, it has become clear that not all effects of cannabinoid drugs are attributable to their interaction with CB1 and CB2 receptors. Evidence now demonstrates that cannabinoid agents produce effects by modulating activity of the entire array of cellular macromolecules targeted by other drug classes, including: other receptor types; ion channels; transporters; enzymes, and protein- and non-protein cellular structures. This review summarizes evidence for these interactions in the CNS and in cancer, and is organized according to the cellular targets involved. The CNS represents a well-studied area and cancer is emerging in terms of understanding mechanisms by which cannabinoids modulate their activity. Considering the CNS and cancer together allow identification of non-cannabinoid receptor targets that are shared and divergent in both systems. This comparative approach allows the identified targets to be compared and contrasted, suggesting potential new areas of investigation. It also provides insight into the diverse sources of efficacy employed by this interesting class of drugs. Obtaining a comprehensive understanding of the diverse mechanisms of cannabinoid action may lead to the design and development of therapeutic agents with greater efficacy and specificity for their cellular targets

Unthinkable biotechnology: the standing-reserves and sacrificial structures of life itself

The emergence of biotechnology has resulted in intense debates about its promises and dangers. Advocates hail its promises, ranging from alleviating starvation through genetically engineered food to curing major diseases through gene therapy and pharmacological discoveries. Opponents decry its dangers, drawing attention to the inherent risks of genetic engineering, cloning, and the patenting of life forms. As these debates have continued, biotechnology has become a dominant mode of understanding the very life of living beings. There is, however, the need to examine the double-edged dynamics by which the discourse takes place. A theoretical framework informed by Heidegger, Foucault, and Agamben reveals that biotechnology is a structure of thought in which living-in-general is constructed as a metabolic “standing-reserve” (Heidegger). In this structure, biotechnological archives hold “life itself” as an ontologically unthinkable placeholder for a general mass of metabolic activity. The discourse of biotechnology constitutes its standing-reserves of the living-in-general by way of three modes that bring forth life for some, while sacrificing others. The first mode is eating, whereby the resources of the world were used to feed the bodies of Western Man, a prerequisite, according to Foucault, for the development of modern democracy. The second mode is incineration, exemplified by hot box experiments conducted by the U.S. Air Force during World War Two, ranging from analysis of heating systems to fire bombing strategies. These experiments enacted the fiery incorporation of bodies in militarized systems that ultimately signified U.S. power. The third mode is feverish genomics, by which scientists store the genomic sequences of all living things in global bioinformatic archives. Intellectual Property Rights, whose prime example is the U.S. Supreme Court’s approval of a patent on a genetically engineered life form (Diamond v. Chakrabarty 1980), defends all three modes as a right and expression of freedom by instituting the force of law. It is only by understanding biotechnology as a sacrificial structure that theoretical work on its privileging of U.S. interests can become more ethically charged

Ron Benner : Trans/mission : African Vectors

McFarlane examines Benner's photo-based works and garden installations. The author points to the tenderness with which Benner "tends" to his plants, and contrasts this care with the violence embedded in agricultural history, which he views as a metaphor for systems of socio-political domination. The imperialist travels of Portuguese explorer Pedro Alvares Cabral are discussed in relation to the circulation of plant species from the Americas to Africa and Europe. Brief biographical notes on the author. 2 bibl. ref