Synthesis of a Versatile Building Block for the Preparation of 6-N-Derivatized α-Galactosyl Ceramides: Rapid Access to Biologically Active Glycolipids

A concise route to the 6-azido-6-deoxy-α-galactosyl-phytosphingosine derivative 9 is reported. Orthogonal protection of the two amino groups allows elaboration of 9 into a range of 6-N-derivatized α-galactosyl ceramides by late-stage introduction of the acyl chain of the ceramide and the 6-N-group in the sugar head-group. Biologically active glycolipids 6 and 8 have been synthesized to illustrate the applicability of the approach

Efficient regeneration protocol for callus and shoot induction from recalcitrant Phaseolus vulgaris L. explants under optimum growth conditions

Callus is the most significant morphogenic response obtained in plant tissue culture studies. It can be used for micropropagation or to create transgenic lines. Phaseolus vulgaris L. (common bean) is one of the economically important crops with a great nutritional value. However, very little effort has been made to regenerate callus from P. vulgaris explants. Six explants were used namely root tip, leaves, plumule, radicle, cotyledon and embryo to develop a callus from P. vulgaris. The minimum days for callus induction was 10 days in plumule, radicle and embryo explants, while the maximum was 15 days in cotyledon explants with the callus induction percentage of 75%. The largest callus was found to be 2.77 gm in weight and 2.5 cm in diameter in MS medium. Medium with different concentrations of plant growth regulators (PGRs) showed different growth pattern in callus induction. Culture medium with 1.50 mg/l of BAP, 0.50 mg/l of 2, 4-D and 0.10 mg/l of NAA showed the best result in callus induction. Higher concentration of BAP (2.00 mg/l), along with 0.25 mg/l of 2, 4-D was ideal for shoot regeneration and maturation. Shoot induction medium along with 2.00 mg/l of NAA concentrations were found to be best for rooting. It was found that plumule and radicle favor callus induction, however, they are also potent for shoot and root induction. Knowledge gained in this study will be useful in developing a standard protocol for plant regeneration from P. vulgaris explants and will also be useful in creating transgenic line of P. vulgaris

How Failure Leads to Learning among Nascent Entrepreneurs? The Evidence of Entrepreneurial Failure and Its Relationship to Entrepreneurial Learning

This paper investigates and examines the relationship between entrepreneurial failure and entrepreneurial learning that can be absorbed by nascent entrepreneurs. It also reveals the possible forms of learning that happen to nascent entrepreneurs as an outcome of failure. A quantitative study with relational approach with 180 failed nascent entrepreneurs in Padang, Indonesia was undertaken as the research method and study context. Data and information were collected by using a questionnaire (offline and online) as the research instrument. Statistical protocol in terms of validity and reliability tests as well as hypothesis testing, using SPSS 23 as the statistical tool were operated to analyze the data. The study found that entrepreneurial failure has significantly influenced [a] entrepreneurial learning of nascent entrepreneurs in the context of the study, [b] the ability to detect errors in business, as well as [c] error correction by nascent entrepreneurs. The study also reveals the fact that the serial entrepreneurship process occurs for nascent entrepreneurs in the context of study. Keywords: entrepreneurial failure, entrepreneurial learning, nascent entrepreneurs, error detection, error correctio

Platensimycin Activity against Mycobacterial β-Ketoacyl-ACP Synthases

Background - There is an urgent need for the discovery and development of new drugs against Mycobacterium tuberculosis, the causative agent of tuberculosis, especially due to the recent emergence of multi-drug and extensively-drug resistant strains. Herein, we have examined the susceptibility of mycobacteria to the natural product platensimycin. Methods and Findings - We have demonstrated that platensimycin has bacteriostatic activity against the fast growing Mycobacterium smegmatis (MIC = 14 µg/ml) and against Mycobacterium tuberculosis (MIC = 12 µg/ml). Growth in the presence of paltensimycin specifically inhibited the biosynthesis of mycolic acids suggesting that the antibiotic targeted the components of the mycolate biosynthesis complex. Given the inhibitory activity of platensimycin against β-ketoacyl-ACP synthases from Staphylococcus aureus, M. tuberculosis KasA, KasB or FabH were overexpressed in M. smegmatis to establish whether these mycobacterial KAS enzymes were targets of platensimycin. In M. smegmatis overexpression of kasA or kasB increased the MIC of the strains from 14 µg/ml, to 30 and 124 µg/ml respectively. However, overexpression of fabH on did not affect the MIC. Additionally, consistent with the overexpression data, in vitro assays using purified proteins demonstrated that platensimycin inhibited Mt-KasA and Mt-KasB, but not Mt-FabH. Significance - Our results have shown that platensimycin is active against mycobacterial KasA and KasB and is thus an exciting lead compound against M. tuberculosis and the development of new synthetic analogues

Mycobacterial drug discovery

Mycobacterium tuberculosis is the causative pathogen of the pulmonary disease tuberculosis. Despite the availability of effective treatment programs, there is a global pursuit of new anti-tubercular agents to respond to the developing threat of drug resistance, in addition to reducing the extensive duration of chemotherapy and any associated toxicity. The route to mycobacterial drug discovery can be considered from two directions: target-to-drug and drug-to-target. The former approach uses conventional methods including biochemical assays along with innovative computational screens, but is yet to yield any drug candidates to the clinic, with a high attrition rate owing to lack of whole cell activity. In the latter approach, compound libraries are screened for efficacy against the bacilli or model organisms, ensuring whole cell activity, but here subsequent target identification is the rate-limiting step. Advances in a variety of scientific fields have enabled the amalgamation of aspects of both approaches in the development of novel drug discovery tools, which are now primed to accelerate the discovery of novel hits and leads with known targets and whole cell activity. This review discusses these traditional and innovative techniques, which are widely used in the quest for new anti-tubercular compounds

The Mediating Effect of Emotive Factor on the Constructs That Influence Entrepreneurial Failure

This paper examines the presence of emotive factor that mediates the variables of voluntaristic, deterministic and opportunistic behaviour that impact entrepreneurial failure. The study is a quantitative study and uses causal analysis as its research approach. It relates the constructs of voluntaristic factor, deterministic factor, and opportunistic behaviour with the mediation of emotive factor to entrepreneurial failure. Sample of the study is 1541 nascent entrepreneurs in West Sumatra Province, Indonesia, who have experienced business failures. Analysis was undertaken by using causal step analysis in which the statistical protocol and rule were operated. The study found and argue that emotive factor of entrepreneurs is identified as individual psychological construct that partially mediates voluntaristic, deterministic and opportunistic behaviour in causing entrepreneurial failure experienced by nascent entrepreneurs. Originality and value of the study lies in the framework used – which considers the construct of opportunistic behaviour of entrepreneurs as an independent variable that can cause entrepreneurial failure. Other is related to the consideration that emotive factor that mediates the voluntaristic, deterministic and opportunistic behaviour in causing entrepreneurial failure.Abstrak dalam Bahasa Indonesia Penelitian ini membahas tentang keberadaan faktor emosi yang memediasi variabel voluntaristic, deterministic dan perilaku opportunis yang mengakibatkan terjadinya kegagalan berwirausaha. Studi ini merupakan studi kuantitatif dan menggunakan analisa kausal sebagai pendekatan penelitian. Sampel penelitian sebanyak 1541 orang wirausahawan pemula di Provinsi Sumatera Barat, Indonesia yang sebelumnya pernah mengalami kegagalan dalam berwirausaha. Analisa dilakukan dengan menggunakan causal step analysis yang menggunakan prosedur statistik tertentu. Studi ini menemukan dan lebih lanjut berpendapat bahwa faktor emotsi wirausahawan diidentifikasi sebagai konstruk psikologis individu yang secara parsial memediasi hubungan faktor voluntaristic, faktor determiniastic dan perilaku opportunis sebagai penyebab terjadinya kegagalan berwirausaha yang dialami oleh wirausahawan pemula. Keaslian dan nilai dari studi ini terletak pada kerangka penelitian yang digunakan, yang menempatkan faktor perilaku opportunis sebagai variabel bebas yang dapat mengakibatkan kegagalan berwirausaha. Hal lainnya terletak pada adanya unsur faktor emotsi yang memediasi faktor voluntaristic, faktor determiniastic dan perilaku opportunis sebagai penyebab kegagalan berwirausah

Electrophoretic Deposition on Porous Non-Conductors

A method of electrophoretic deposition (EPD) on substrates that are porous and electrically non-conductive has been invented. Heretofore, in order to perform an EPD, it has been necessary to either (1) use a substrate material that is inherently electrically conductive or (2) subject a non-conductive substrate to a thermal and/or chemical treatment to render it conductive. In the present method, instead of relying on the electrical conductivity of the substrate, one ensures that the substrate is porous enough that when it is immersed in an EPD bath, the solvent penetrates throughout the thickness, thereby forming quasi-conductive paths through the substrate. By making it unnecessary to use a conductive substrate, this method simplifies the overall EPD process and makes new applications possible. The method is expected to be especially beneficial in enabling deposition of layers of ceramic and/or metal for chemical and electrochemical devices, notably including solid oxide fuel cells

Pattern of specific dermatoses of pregnancy: a hospital based study

Background: The specific dermatoses of pregnanc represent a heterogenous group of ill-defined pruritic skin diseases related specifically to pregnancy and/or the immediate postpartum period. The objective of the study is to determine the patterns of specific dermatoses of pregnancy in a tertiary care hospital.Methods: A total of 450 pregnant females, irrespective of their parity and gestational age were screened for various pruritic skin conditions and those with specific pregnancy dermatoses were identified and evaluated.Results: The age of the study population ranged from 18 to 36 years (mean age 24 years). The study population included 261 (58%) primigravidae and 189 (42%) multigravidae. Seventeen (3.77%) pregnant females had specific dermatoses of pregnancy. Out of these, 9 (52.94%) had pruritic urticarial papules and plaques of pregnancy (PUPPP), followed by pruritic folliculitis of pregnancy in 5 (29.41%), pruritic gravidarum in 2 (11.76%) and pemphigoid gestationis in 1 (5.88%). PUPPP was the commonest specific dermatoses noted in our study.Conclusions: The present study highlights the pattern of specific dermatoses of pregnancy in our hospital. Early diagnosis of specific dermatoses of pregnancy may prevent harmful effect on mother and fetus. The pruritic eruptions of pregnancy, which are not a rare entity can be a source of significant distress to the pregnant female and need timely therapeutic intervention