Theory of high bias Coulomb Blockade in ultrashort molecules

We point out that single electron charging effects such as Coulomb Blockade (CB) and high-bias staircases play a crucial role in transport through single ultrashort molecules. A treatment of Coulomb Blockade through a prototypical molecule, benzene, is developed using a master-equation in its complete many-electron Fock space, evaluated through exact diagonalization or full Configuration Interaction (CI). This approach can explain a whole class of non-trivial experimental features including vanishing zero bias conductances, sharp current onsets followed by ohmic current rises, and gateable current levels and conductance structures, most of which cannot be captured even qualitatively within the traditional Self Consistent Field (SCF) approach coupled with perturbative transport theories. By comparing the two approaches, namely SCF and CB, in the limit of weak coupling to the electrode, we establish that the inclusion of strong-correlations within the molecule becomes critical in addressing the above experiments. Our approach includes on-bridge-correlations fully, and is therefore well-suited for describing transport through short molecules in the limit of weak coupling to electrodes.Comment: 19 pages 5 figure

Comments Welcome

Management. We thank the participants at the University of Michigan brown bag workshop for helpful comments and suggestions. Any errors are our own. Do stock prices underreact to SEO announcements? Evidence from SEO Valuation This paper examines whether the market underreacts to the negative information implicit in SEO announcements. We find that it does but conditional on the valuation of SEO firms prior to the SEO issue date. SEO firms that are overvalued relative to their industry peers experience a smaller decline in market value on the SEO announcement day but experience a larger decline over the next five years. The results are robust to various ways of choosing industry peers and valuation multiples and various methodologies for computing risk-adjusted abnormal returns. Cross-sectional regressions indicate SEO P/V ratios (offer-price to value ratio based on relative valuation techniques) are significantly positively related to announcement day returns and significantly negatively related to long-run returns even after controlling for expected growth rates, accruals, and B/M ratios. Additional tests indicate overvalued SEOs earn lower returns around future quarterly earnings announcement dates and do not exhibit superior ex-pos

Evaluation of drug promotional brochures in a tertiary teaching hospital of Kannur, India

Background: Pharmaceutical industries worldwide are heavily involved in aggressive drug promotions. WHO has framed guidelines for ethical drug promotion in 1988. The transparency of pharmaceutical advertisements is important because decision of the physician is likely to be influenced by the claims made by the pharmaceutical companies in the promotional drug brochures and pharmaceutical industries treat their marketing material as “educational material” for doctors. Authors did this study to analyze the information given on drug promotional brochures by the drug companies using ethical criteria of drug promotion by WHO 1988 and to verify the authenticity of the claims given by the pharmaceutical companies in drug promotional brochures.Methods: Cross sectional study extending from 1/8/2012 to 31/7/2013. 612 drug promotional brochures satisfied our inclusion criteria. Drug brochures were analyzed with WHO ethical criteria 1988 and further categorizing the data into type of claims, number and source of references. Validity of journal articles were checked by using a validity measure developed by Cardarelli.Results: Total 612 brochures satisfied inclusion criteria. INN was mentioned in 93.8% of collected brochures. Brand name was mentioned in 100% brochures. Content of active ingredients was mentioned in 92% of brochures. Name of the other ingredients known to cause problem 28.4% of brochures. Dosage form or regimen was mentioned in 23.2% of brochures. Approved therapeutic use mentioned in 65.7% brochures. Side effects and major adverse drug reactions were mentioned in 31.4% brochures. Precautions and contraindications and warnings were mentioned in 30.4% drug promotional brochures. Drug interactions were mentioned in 26.5% brochures. Name and address was mentioned by 69.1% brochures. There were 1144 claims and 739 references. Efficacy claims were 84.88% of the total claims. Main source of reference was from journal articles (74.1%) and among them 49.65% were randomized control trials. Only 47.94 % of the journal references were valid.Conclusions: Brochures were lacking in vital information which included contraindication, warning, precaution, name of the other ingredients known to cause problem hence companies were found violating WHO ethical criteria. Claims were not well supported with references. Less than half of the given journal references were only valid. This study highlights the need of healthcare professionals to remain cautious about promotional material presented by pharmaceutical representatives

मानसून के दौरान बुकानीर ऐंचोवी का उपतट प्रवास

कृपया पूरा लेखा पढ

Indirect and direct somatic embryogenesis from aerial stem explants of ginger (Zingiber officinale Rosc.)

Protocols for direct and indirect somatic embryogenesis from aerial stem explants of ginger have been developed. Aerial stem explants of two ginger varieties were cultured on different concentrations of 2,4-D induced callus. An in vitro aerial stem produced hard, nodular and yellowish callus (Type I) and an in planta aerial stem gave rise to soft, sticky callus with pale white color (Type II). The proliferated Type II calli were subject to stress for 40–60 days without subculturing. The desiccated calli produced white friable calli which turned embryogenic and then produced somatic embryos in a medium containing 2 mg L–1 benzyl amino purine. The mature, club-shaped somatic embryos were germinated on a medium containing benzyl amino purine and a – naphthalene acetic acid in different concentrations. Type I callus of neither variety turned embryogenic but produced roots in all the cultures. Direct somatic embryogenesis was observed from the in planta aerial stem and leaf base explants with the use of thidiazuron alone or in combination with indole, 3-butyric acid. Histological studies revealed that the somatic embryos in ginger have a distinct single layered epidermis, scutellum, coleoptile, shoot apex and root apex

In situ nanoindentation: probing nanoscale multifunctionality

Nanoindentation is the leading technique for evaluating nanoscale mechanical properties of materials. Consistent developments in instrumentation and their capabilities are transforming nanoindentation into a powerful tool for characterization of multifunctionality at the nanoscale. This review outlines the integration of nanoindentation with real-time electron imaging, high temperature measurements, electrical characterization, and a combination of these. In situ nanoindentation measurements have enabled the real-time study of the interplay between mechanical, thermal, and electrical effects at the nanoscale. This review identifies previous reviews in this area, traces developments and pinpoints significant recent advances (post-2007), with emphasis on the applications of in situ nanoindentation techniques to materials systems, and highlighting the new insights gained from these in situ techniques. Based on this review, future directions and applications of in situ nanoindentation are identified, which highlight the potential of this suite of techniques for materials scientists from all disciplines

Rapid detection of Ganoderma lucidum and assessment of inhibition effect of various control measures by immunoassay and PCR

Molecular and immunological methods have been applied for detecting the Ganoderma disease of coconut. Polyclonal antibodies (PAbs) raised against basidiocarp protein of Ganoderma were used for detection. For polymerase chain reaction (PCR) test, the primer generated from the internal transcribed spacer region one (ITS 1) of ribosomal DNA gene of Ganoderma, which produced a PCR product of 167 bp in size is used for early detection. Ganoderma disease in apparently healthy palms in two coconut gardens was tested by ELISA test using basidiocarp protein antiserum. Field trials were laid out in these early-diagnosed palms for the management of the disease. Based on the ELISA results,Pseudomonas fluorescens + Trichoderma viride with chitin amended treatments arrested the multiplication of the pathogen and showed below the infection level of optical density (O.D) within six months. Integrated disease management (IDM) and fungicide tridemorph treated palms showed below infection level (O.D value) within seven months and T. harzianum and P. fluorescens + T. viride treatedpalms showed below infection level (OD value) of the disease in eighth months