Palladium-Catalyzed Cross-Coupling of 2-Aryl-1,3-Dithianes

Palladium-catalyzed cross-coupling of aryl bromides with 2-aryl-1,3-dithianes is described. This methodology takes advantage of the relatively acidic benzylic proton of the dithiane, allowing it to act as a competent, polarity-reversed transmetalation reagent. This unique approach affords the ability to employ an orthogonal deprotection strategy, and practical routes to both diaryl ketones and diarylmethanes are illustrated. Cross-coupling of a range of aryl dithianes with aryl bromides, including scope and current limitations, is presented

A non-traditional approach to synthesizing aryl vinyl sulfides is described. 2,2-diphenyl-1,3-oxathiolane slowly liberates vinyl sulfide anion under basic conditions. Using a Pd/Xantphos catalyst system to activate a wide range of aryl bromides, this transient sulfide species can be effectively trapped and fed into a traditional Pd0/PdII catalytic cycle. Scope and limitations of the methodology are presented along with significant discussion of a competitive C–S bond activation by this catalyst system.

A non-traditional approach to synthesizing aryl vinyl sulfides is described. 2,2-diphenyl-1,3-oxathiolane slowly liberates vinyl sulfide anion under basic conditions. Using a Pd/Xantphos catalyst system to activate a wide range of aryl bromides, this transient sulfide species can be effectively trapped and fed into a traditional Pd0/PdII catalytic cycle. Scope and limitations of the methodology are presented along with significant discussion of a competitive C–S bond activation by this catalyst system

Meningococcus genome informatics platform: a system for analyzing multilocus sequence typing data

The Meningococcus Genome Informatics Platform (MGIP) is a suite of computational tools for the analysis of multilocus sequence typing (MLST) data, at http://mgip.biology.gatech.edu. MLST is used to generate allelic profiles to characterize strains of Neisseria meningitidis, a major cause of bacterial meningitis worldwide. Neisseria meningitidis strains are characterized with MLST as specific sequence types (ST) and clonal complexes (CC) based on the DNA sequences at defined loci. These data are vital to molecular epidemiology studies of N. meningitidis, including outbreak investigations and population biology. MGIP analyzes DNA sequence trace files, returns individual allele calls and characterizes the STs and CCs. MGIP represents a substantial advance over existing software in several respects: (i) ease of use—MGIP is user friendly, intuitive and thoroughly documented; (ii) flexibility—because MGIP is a website, it is compatible with any computer with an internet connection, can be used from any geographic location, and there is no installation; (iii) speed—MGIP takes just over one minute to process a set of 96 trace files; and (iv) expandability—MGIP has the potential to expand to more loci than those used in MLST and even to other bacterial species

Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

No abstract available

A Behavioral Change Perspective of Maroon Soil Fertility Management in Traditional Shifting Cultivation in Suriname

In Suriname, the Maroons have practiced shifting cultivation for generations, but now the increasing influence of modern society is causing a trend of decreasing fallow periods with potentially adverse effects for the vulnerable tropical soils. Adoption of appropriate soil fertility management (SFM) practices is currently slow. Combining methods from cultural ecology and environmental psychology, this study identifies two groups with divergent behavioral intentions which we term semi-permanent cultivators and shifting cultivators. Semi-permanent cultivators intend to practice more permanent agriculture and experiment individually with plot-level SFM. Shifting cultivators rely on traditional knowledge that is not adequate for their reduced fallow periods, but perceive constraints that prevent them practicing more permanent agriculture. Semi-permanent cultivators act as a strong reference group setting a subjective norm, yet feel no need to exchange knowledge with shifting cultivators who are in danger of feeling marginalized. Drawing on a political ecology perspective, we conclude that cultural ecological knowledge declined due to negative perceptions of external actors setting a strong subjective norm. Semi-permanent cultivators who wish to enter the market economy are most likely to adopt SFM. We conclude that any future SFM intervention must be based on an in-depth understanding of each group’s behavior, in order to avoid exacerbating processes of marginalization

sodC-Based Real-Time PCR for Detection of Neisseria meningitidis

Real-time PCR (rt-PCR) is a widely used molecular method for detection of Neisseria meningitidis (Nm). Several rt-PCR assays for Nm target the capsule transport gene, ctrA. However, over 16% of meningococcal carriage isolates lack ctrA, rendering this target gene ineffective at identification of this sub-population of meningococcal isolates. The Cu-Zn superoxide dismutase gene, sodC, is found in Nm but not in other Neisseria species. To better identify Nm, regardless of capsule genotype or expression status, a sodC-based TaqMan rt-PCR assay was developed and validated. Standard curves revealed an average lower limit of detection of 73 genomes per reaction at cycle threshold (Ct) value of 35, with 100% average reaction efficiency and an average R2 of 0.9925. 99.7% (624/626) of Nm isolates tested were sodC-positive, with a range of average Ct values from 13.0 to 29.5. The mean sodC Ct value of these Nm isolates was 17.6±2.2 (±SD). Of the 626 Nm tested, 178 were nongroupable (NG) ctrA-negative Nm isolates, and 98.9% (176/178) of these were detected by sodC rt-PCR. The assay was 100% specific, with all 244 non-Nm isolates testing negative. Of 157 clinical specimens tested, sodC detected 25/157 Nm or 4 additional specimens compared to ctrA and 24 more than culture. Among 582 carriage specimens, sodC detected Nm in 1 more than ctrA and in 4 more than culture. This sodC rt-PCR assay is a highly sensitive and specific method for detection of Nm, especially in carriage studies where many meningococcal isolates lack capsule genes