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The author looks through Albert Bandura's self-efficacy lens onto the effects it likely has on school principals' effectiveness. Self-efficacy should be viewed as a principal's belief in his or her capabilities to structure a particular course of action in order to produce desired outcomes. Principal self-efficacy has been linked with effective leadership, effective schools, the school restructuring process, and the quality of teaching and learning. Principals' thoughts and actions influence the school culture, and research indicates that a principal can have a negative effect during a period of change. For these reasons, it is important for principals to have a strong sense of self-efficacy.

Students are often required to create work in a vacuum, handing in papers to an inauthentic audience for the purpose of receiving a grade. As a result, students often neglect to consider the effects that their work can have on others. In this article, the author highlights an art project from her middle school in Kings Park, New York, that challenged this concept. Students used chalk to create mandalas (symbolic geometric patterns with designs emanating from a center point) on the outdoor walkway leading to their school's entrance. The students then undertook an action research project to determine if their creations influenced the moods of school community members. Like many other public art installations, this endeavor caused the community--students and teachers alike--to reconsider the purpose of what they create and the impact it has on others.

While recent state and federal education policies convey a sense of urgency in regard to the need for education reforms, there are teachers for whom this sense of urgency has long been woven into the fabric of their practice. Fortified by their high expectations for their students, these teachers utilize strategies that convey the message that the work is worthwhile and important; it is "work that matters." Among the factors that foster a sense of urgency in the classroom are the skillful use of time and purposeful planning; they promote motivation, engagement, and student accountability.

This paper reports on a study (commissioned by central government) of a specialist social work service provided by local government agencies (local authorities) in Ireland. The service originated in the 1960s, was designed to meet the accommodation related needs of Travellers, an indigenous, Irish, ethnic group, who have faced centuries of social exclusion and discrimination. The paper begins with an account of the economic and social problems faced by Travellers and then the few available Irish and UK publications. It then reports on qualitative findings drawn from interviews with social workers, Travellers and other key stakeholders. The idiom 'betwixt and between' is used to characterise the social work role. Respondents aspired to forms of social action and advocacy roles but were sometimes viewed with suspicion by Traveller activists. Local authority structures were overly focused on non-social work functions where social work expertise was rarely acknowledged or utilised. This partly explains why social workers faced challenges in upholding their professional values, regulatory obligations and continuous professional development. The authors conclude by arguing for a more clearly defined, human-rights based social work role, referencing lessons that can be drawn from the wider European literature. [ABSTRACT FROM AUTHOR]

Acetyl coenzyme A (AcCoA) is the central biosynthetic precursor for fatty-acid synthesis and protein acetylation. In the conventional view of mammalian cell metabolism, AcCoA is primarily generated from glucose-derived pyruvate through the citrate shuttle and ATP citrate lyase in the cytosol (1-3). However, proliferating cells that exhibit aerobic glycolysis and those exposed to hypoxia convert glucose to lactate at near-stoichiometric levels, directing glucose carbon away from the tricarboxylic acid cycle and fatty-acid synthesis (4). Although glutamine is consumed at levels exceeding that required for nitrogen biosynthesis (5), the regulation and use of glutamine metabolism in hypoxic cells is not well understood. Here we show that human cells use reductive metabolism of a-ketoglutarate to synthesize AcCoA for lipid synthesis. This isocitrate dehydrogenase-1 (IDH1)-dependent pathway is active in most cell lines under normal culture conditions, but cells grown under hypoxia rely almost exclusively on the reductive carboxylation of glutamine-derived α-ketoglutarate for denovolipogenesis. Furthermore, renal cell lines deficient in the von Hippel-Lindau tumour suppressor protein preferentially use reductive glutamine metabolism for lipid biosynthesis even at normal oxygen levels. These results identify a critical role for oxygen in regulating carbon use to produce AcCoA and support lipid synthesis in mammalian cells., Although hypoxic cells exhibit a shift towards glycolytic metabolism (4), a functional electron transport chain and glutamine-derived carbon are required for proliferation of most transformed cells (6). In line with [...]

Systems level tools for the quantitative analysis of metabolic networks are required to engineer metabolism for biomedical and industrial applications. While current metabolomics techniques enable high-throughput quantification of metabolites, these methods provide minimal information on the rates and connectivity of metabolic pathways. Here we present a new method, nontargeted tracer fate detection (NTFD), that expands upon the concept of metabolomics to solve the above problems. Through the combined use of stable isotope tracers and chromatography coupled to mass spectrometry, our computational analysis enables the quantitative detection of all measurable metabolites derived from a specific labeled compound. Without a priori knowledge of a reaction network or compound library, NTFD provides information about relative flux magnitudes into each metabolite pool by determining the mass isotopomer distribution for all labeled compounds. This novel method adds a new dimension to the metabolomics tool box and provides a framework for global analysis of metabolic fluxes. 10.1021/ac1011574

We developed a LC-MS-MS assay of the [sup.2]H labeling of free glutathione (GSH) and bound glutathione [GSSR; which includes all DTT-reducible forms, primarily glutathione disulfide (GSSG) and mixed disulfides with proteins] and ophthalmate (an index of GSH depletion) labeled from [sup.2]H-enriched body water. In rats whose body water was 2.5% [sup.2]H enriched for up to 31 days, GSH labeling follows a complex pattern because of different rates of labeling of its constitutive amino acids. In rats infused with [[sup.13][C.sub.2], [sup.15]N-glycine]glutathione, the rate of appearance of plasma GSH was 2.1 [micro]mol x [min.sup.-1] x [kg.sup.-1], and the half-life of plasma GSH/GSSR was 6-8 min. In healthy humans whose body fluids were 0.5% [sup.2]H enriched, the [sup.2]H labeling of GSH/GSSR and ophthalmate can be precisely measured after 4 h, with GSH being more rapidly labeled than GSSR. Since plasma GSH/GSSR derives mostly from liver, this technique opens the way to 2) probe noninvasively the labeling pattern and redox status of the liver GSH system in humans and 2) assess the usefulness of ophthalmate as an index of GSH depletion. mass isotopomer analysis; oxidative stress; protein synthesis; peptide synthesis; deuterated water; liver

Metabolic flux analysis based on stable-isotope labeling experiments and analysis of mass isotopomer distributions (MID) of cellular metabolites is a tool of great significance for metabolic engineering and study of human disease. This method relies on accurate and precise measurements of mass isotopomers by gas chromatography/mass spectrometry. To improve flux estimates, we assessed potential errors in determining MID of tertbutyldimethylsilyl-derivatized amino acids, which were attributed to (i) the choice of integration algorithm, (ii) concentration effects, and (iii) overlapping fragments. We report 29 amino acid fragments that are useful for flux analysis and another 18 fragments that should be rejected, most importantly Val-302, Leu-200, Leu-302, I1e-302, Ser-302, and Asp-316. In addition, we provide a protocol to minimize errors for determining MID to less than 0.4 mol % for accepted fragments.

Little is known about the sources of cytosolic acetyl-CoA used for the synthesis of malonyl-CoA, a key regulator of fatty acid oxidation in the heart. We tested the hypothesis that citrate provides acetyl-CoA for malonyl-CoA synthesis after its mitochondrial effiux and cleavage by cytosolic ATP-citrate lyase. We expanded on a previous study where we characterized citrate release from perfused rat hearts (Vincent G, Comte B, Poirier M, and Des Rosiers C. Citrate release by perfused rat hearts: a window on mitochondrial cataplerosis. Am J Physiol Endocrinol Metab 278: E846-E856, 2000). In the present study, we show that citrate release rates, ranging from 6 to 22 nmol/min, can support a net increase in malonyl-CoA concentrations induced by changes in substrate supply, at most 0.7 nmol/min. In experiments with [U-[sup.13]C](lactate + pyruvate) and [1-[sup.13]C]oleate, we show that the acetyl moiety of malonyl-CoA is derived from both pyruvate and long-chain fatty acids. This [sup.13]C-labeling of malonyl-CoA occurred without any changes in its concentration. Hydroxycitrate, an inhibitor of ATP-citrate lyase, prevents increases in malonyl-CoA concentrations and decreases its labeling from [U-[sup.13]C](lactate + pyruvate). Our data support at least a partial role of citrate in the transfer from the mitochondria to cytosol of acetyl units for malonyl-CoA synthesis. In addition, they provide a dynamic picture of malonyl-CoA metabolism: even when the malonyl-CoA concentration remains constant, there appears to be a constant need to supply acetyl-CoA from various carbon sources, both carbohydrates and lipids, for malonyl-CoA synthesis. gas chromatography-mass spectrometry; adenosine 5'-triphosphate-citrate lyase; hydroxycitrate; acetyl-coenzyme A; citric acid cycle; [sup.13]C-substrate; isotopomer analysis

Analysis of cholesterol synthesis using isotopomer spectral techniques reveals that this process is useful for a condensation bioynthesis, which is not a simple polymerization. The method may also be applied to models with more than two unknown factors. The models are developed to study cholesterol synthesis from varying precursors, including mevalonate, acetate and acetoacetate.

Abstract Background Obesity is associated with insulin resistance that can often be improved by caloric restriction and weight reduction. Although many physiological changes accompanying insulin resistance and its treatment have been characterized, the genetic mechanisms linking obesity to insulin resistance are largely unknown. We used DNA microarrys and RT-PCR to investigate significant changes in hepatic gene transcription in insulin resistant, diet-induced obese (DIO)-C57/BL/6J mice and DIO-C57/BL/6J mice fasted for 48 hours, whose weights returned to baseline levels during these conditions. Results Transcriptional profiling of hepatic mRNA revealed over 1900 genes that were significantly perturbed between control, DIO, and fasting/weight reduced DIO mice. From this set, our bioinformatics analysis identified 41 genes that rigorously discriminate these groups of mice. These genes are associated with molecular pathways involved in signal transduction, and protein metabolism and secretion. Of particular interest are genes that participate in pathways responsible for modulating insulin sensitivity. DIO altered expression of genes in directions that would be anticipated to antagonize insulin sensitivity, while fasting/ weight reduction partially or completely normalized their levels. Among these discriminatory genes, Sh3kbp1 and RGS3, may have special significance. Sh3kbp1, an endogenous inhibitor of PI-3-kinase, was upregulated by high-fat feeding, but normalized to control levels by fasting/weight reduction. Because insulin signaling occurs partially through PI-3-kinase, increased expression of Sh3kbp1 by DIO mice may contribute to hepatic insulin resistance via inhibition of PI-3-kinase. RGS3, a suppressor of G-protein coupled receptor generation of cAMP, was repressed by high-fat feeding, but partially normalized by fasting/weight reduction. Decreased expression of RGS3 may augment levels of cAMP and thereby contribute to increased, cAMP-induced, hepatic glucose output via phosphoenolpyruvate carboxykinase (PCK1), whose mRNA levels were also elevated. Conclusion These findings demonstrate that hepatocytes respond to DIO and weight reduction by controlling gene transcription in a variety of important molecular pathways. Future studies that characterize the physiological significance of the identified genes in modulating energy homeostasis could provide a better understanding of the mechanisms linking DIO with insulin resistance.

Kelleher, Joanne K. Estimating gluconeogenesis with [U-[sup.13]C]glucose: molecular condensation requires a molecular approach. Am. J. Physiol. 277 (Endocrinol. Metab. 40): E395-E400, 1999.--Recently three equations for estimating gluconeogenesis in vivo have been proposed, two by J. A. Tayek and J. Katz [Am. J. Physiol. 270 (Endocrinol. Metab. 33): E709-E717, 1996, and Am. J. Physiol. 272 (Endocrinol. Metab. 35): E476-E484, 1997] and one by B. R. Landau, J. Wahren, K. Ekberg, S. F. Previs, D. Yang, and H. Brunengraber [Am. J. Physiol. 274 (Endocrinol. Metab. 37): E954-E961, 1998]. Both groups estimate gluconeogenesis from cycling of [U-[sup.13]C]glucose to lactate and back to glucose, detected by mass spectrometry. Landau's approach is based on analysis of labeled molecules, whereas Tayek and Katz's is based on labeling of carbon atoms by use of the concept of 'molar enrichment,' which weights each mass isotopomer by the number of labeled carbons. We derived an equation very similar to Landau's using binomial probability. Our analysis demonstrates that the molecular-based approach is correct. Additionally, equations appropriate for [sup.14]C studies are not appropriate for [sup.13]C studies, because the method used to detect [sup.14]C, decay of atoms, differs from [sup.13]C mass isotopomers detected as labeled molecules. We conclude that the molar enrichment carbon-based approach is not useful in the derivation of equations for the polymerization of molecules detected by mass spectrometry of molecules, and we confirm the findings of Landau et al. glucose; molecular condensation; stable isotopes; gas chromatography-mass spectrometry