Bark is the hallmark

The bark of a tree is essential for its survival on this planet. Trees show great diversity in their bark morphology which helps in the taxonomic identification of the species. This article discusses various peculiarities, chemical constituents and commercial uses of the bark.     

Performance Evaluation of Modified Black Clay as a Heterogeneous Fenton Catalyst on Decolorization of Azure B Dye: Kinetic Study and Cost Evaluation

Black clay(BC) was used as a catalyst for the decolorization of Azure B dye by Fenton process. BC was modified by acid, alkali, distilled water, and calcination to check their changes in characterization and efficiency on decolorization of Azure B. Among three modified catalysts, maximum decolorization was obtained by acid-modified BC(AMBC) catalyst due to the highest removal of impurities, comparatively. The characterization of AMBC was done by Fourier-transform infrared spectroscopy and X-ray diffraction spectroscopy which show the presence of metal ion. The BET surface area, pore volume, pore size, and density of AMBC were calculated to be 79.402 m~2/g, 0.0608 m~3/g, 0.00306 nm, and 16 g/cm~3, respectively. The highest decolorization of 97.59% was achieved only in 10 min using AMBC at optimized calcination of 100 °C and 3 h of aging. AMBC was considered as the main catalyst for optimizing the different process parameters. Optimized conditions were obtained: pH 2, 0.2 mL of H_2O_2, catalyst dose 0.3 g, room temperature(30 °C), and stirring speed 400 r/min. The catalyst has showed excellent stability and reusability. It could remove more than 85% of color even after four cycles of run and less than negligible leaching of iron. AMBC has good recycling ability among other modified catalysts. To check the selectivity of catalyst, different dyes such as Congo red and mixed dye(mixture of Azure B and Congo red) decolorization were studied. In the present work, kinetic study was also carried out and a three-stage decolorization process was found.     

A Synergistic Role of Myeloperoxidase and High Sensitivity Troponin T in the Early Diagnosis of Acute Coronary Syndrome

Aim of this study was to evaluate the role of Myeloperoxidase (MPO) and high sensitive Troponin T in the early diagnosis of acute coronary syndrome (ACS). This was a cross sectional study that comprised of 120 individuals of which 75 were cases and 45 healthy controls. On the basis of clinical history and 12 lead electrocardiogram initial diagnosis of ACS was made in the cases. MPO and high sensitive Troponin T (hs-cTnT) was measured in all the individuals. Levels of MPO were significantly higher in patients of ACS as compared to those in control group [medians: 15.40 (95 % CI 11.06–20.84) vs 5.84 (95 % CI 5.50–6.44)]. By taking the cut off as >11.87 U/mL for MPO, its sensitivity was 87 % (95 % CI 73.7–95.1), specificity was 97.3 % (95 % CI 90.6–99.7), positive predictive value was 94.6 % and negative predictive value was 92.6 %. Positive likelihood ratio was 33.0 while negative likelihood ratio was 0.13, whereas the corresponding values in case of hs-cTnT were 95.6 % (95 % CI 85.2–99.5), 61.3 % (95 % CI 49.5–72.6), 59.7 %, 95.8 %, 2.47 and 0.07 by taking cut off as >14 pg/ml. The area under the ROC curves (AUC) of MPO and hscTnT at 0–6 h were 0.971 (95 % CI 0.92–0.99, P < 0.001) and 0.797 (95 % CI 0.71–0.86, P < 0.001) respectively. The logistic model combining the two markers yielded sensitivity, specificity, positive predictive value and negative predictive value of 95.7, 97.3, 98.2 and 93.7 % respectively. It was concluded that MPO and hs-cTnT may be useful tools for risk stratification of ACS and can be used together with better accuracy in the early diagnosis of ACS.     

Effect of simultaneous sodium oxalate and methionine feeding with and without Varuna (Crataeva nurvala hook & Frost) therapy on urolithogenesis in guinea pigs

The effect of sodium oxalate and methionine supplementation on stone-related constituents of urine was studied in 18 adult male guinea pigs. Their serum and tissue chemistry and histological changes in urinary tract and liver were also studied. The calciuretic effect of methionine was blocked by oxalate. The decrease in uric acid and citric acid, caused by oxalate, was offset by methionine. Oxalate-induced crystalluria and calcium and oxalate deposition in kidney tissue were lessened by methionine. Administration of Varuna, an indigenuous drug, to oxalate and methionine-supplemented animals prevented either totally or partially most of the urolithogenic effects of oxalate and methionine.     

Polymorphisms of CYP1A1, GSTM1 and GSTT1 Loci as the Genetic Predispositions of Oral Cancers and Other Oral Pathologies: Tobacco and Alcohol as Risk Modifiers

Polycyclic aromatic hydrocarbons of tobacco require activation by phase I enzymes, such as cytochrome-P4501A1 (CYP1A1) to become an ultimate carcinogen, which are subjected to detoxification by phase II enzymes, especially glutathione S-transferases (GSTs). A study was designed to find whether genetic predisposition are risk modifiers of oral pathologies. The study included 102 cases with Oral Cancers (OCs), 68 cases with nonmalignant pathologies, 100 cases as control group. GSTM1 null genotype was associated with increased risk of OCs but not with benign pathologies. Deleted GSTT1 was associated with all pathologies. Both m1m2 and m2m2 polymorphisms of CYP1A1 were associated with oral pathologies.     

Strategic interaction among public school districts: Evidence on spatial interdependence in school inputs

This paper provides evidence on strategic interaction among public school districts in Massachusetts. The open enrollment program in Massachusetts is unique in testing the strategic competition thesis because it allows students to attend public schools located outside their home district. For each student who transfers out, funds are deducted from the sending district's local aid distribution and added to the receiving district's local aid. Thus, school districts no longer have the assurance of a ready supply of students and funding, instead they have to compete with neighboring districts, and enact strategies that will help retain as well as attract more students. A spatial econometric framework is applied to disentangle the correlation due to strategic interaction from the one that is simply due to spatially correlated error shocks. The results show that public school districts respond positively to the expenditure decisions of neighboring districts, thereby acting strategically when setting their own spending levels.     

No Evidence for Mutations that Deregulate GARS–AIRS–GART Protein Levels in Children with Down Syndrome

GARS–AIRS–GART is crucial in studies of Down syndrome (DS)-related mental retardation due to its chromosomal location (21q22.1), involvement in de novo purine biosynthesis and over-expression in fetal DS brain postmortem samples. GARS–AIRS–GART regions important for structure–function were screened for mutations that might alter protein levels in DS patients. Mutation screening relied on multiplex/singleplex PCR-based amplification of genomic targets followed by amplicon size determination/fingerprinting. Serum protein samples were resolved by SDS-PAGE and immunoblotted with a GARS–AIRS–GART monoclonal antibody. No variation in amplicon size/fingerprints was observed in regions encoding the ATP-binding, active site residues of GARS, the structurally important glycine-rich loops of AIRS, substrate-binding, flexible and folate-binding loops of GART or the poly-adenylation signal sequences. The de novo occurrence or inheritance of large insertion/deletion/rearrangement-type mutations is therefore excluded. Immunoblots show presence of GARS–AIRS–GART protein in all patient samples, with no change in expression levels with respect to either sex or developmental age.     

Banking on the Present: The Ontological Rhetoric of Neo-Classical Economics and Its Relation to the 2008 Financial Crisis

This essay performs a rhetorical criticism of neo-classical economics, with particular attention to its methodological influence on a number of faulty mathematical models that lay at the epicenter of the 2008 financial crisis. Going beyond Goodnight and Green's mimetic conception of economic rhetoric, which positions rhetoric as a site of mediation between symbolic and material spirals, we argue that the rhetoric of neo-classicism is best understood as an “apparatus” that attempts to suture two ontologically incommensurable conceptions of time that we term intensive and extensive. We further argue that the hinge of this rhetorical apparatus centers on a kairotic tactic of arbitrage, which theoretically posits, at the same time that it negates, ontological market failure. We end by exploring rhetorical alternatives to neo-classical economics that take the internally contradictory structure of arbitrage to its emergent conclusions.     

Classroom

In this section of Resonance, we invite readers to pose questions likely to be raised in a classroom situation. We may suggest strategies for dealing with them, or invite responses, or both. “Classroom” is equally a forum for raising broader issues and sharing personal experiences and viewpoints on matters related to teaching and learning science.