Alterations in lipid and fatty acid composition of the cyanobacterium Scytonema geitleri bharadwaja under water stress

The composition of the glycerolipids [monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), sulfoquinovosyl diacylglycerol (SQDG) and phosphatidylglycerol (PG)] and alterations in their saturation and unsaturation levels in response to osmotic and matric water potential have been investigated in the cyanobacterium Scytonema geitleri Bharadwaja. The level of MGDG in S. geitleri was high followed by PG, DGDG and SQDG. Whereas, the amount of fatty acids namely palmitic, stearic, oleic, linoleic and linolenic acid were high, arachidic and behenic acid were, however, present in traces in the four glycerolipids. A significant reduction in the level of total lipid as well as individual class lipid was observed in S. geitleri in response to matric water potential to that of its total lipid and individual class lipid in response to osmotic water potential. The levels of polyunsaturated and unsaturated fatty acids also increased in response to matric water potential to that of osmotic water potential.

Locus minimization in breed prediction using artificial neural network approach

Molecular markers, viz. microsatellites and single nucleotide polymorphisms, have revolutionized breed identification through the use of small samples of biological tissue or germplasm, such as blood, carcass samples, embryos, ova and semen, that show no evident phenotype. Classical tools of molecular data analysis for breed identification have limitations, such as the unavailability of referral breed data, causing increased cost of collection each time, compromised computational accuracy and complexity of the methodology used. We report here the successful use of an artificial neural network (ANN) in background to decrease the cost of genotyping by locus minimization. The webserver is freely accessible (http://nabg.iasri.res.in/bisgoat) to the research community. We demonstrate that the machine learning (ANN) approach for breed identification is capable of multifold advantages such as locus minimization, leading to a drastic reduction in cost, and web availability of reference breed data, alleviating the need for repeated genotyping each time one investigates the identity of an unknown breed. To develop this model web implementation based on ANN, we used 51,850 samples of allelic data of microsatellite-marker-based DNA fingerprinting on 25 loci covering 22 registered goat breeds of India for training. Minimizing loci to up to nine loci through the use of a multilayer perceptron model, we achieved 96.63% training accuracy. This server can be an indispensable tool for identification of existing breeds and new synthetic commercial breeds, leading to protection of intellectual property in case of sovereignty and bio-piracy disputes. This server can be widely used as a model for cost reduction by locus minimization for various other flora and fauna in terms of variety, breed and/or line identification, especially in conservation and improvement programs.

Assessment of the oral health status of healthcare-seeking adults living with HIV in Kathmandu Valley, Nepal

AIMS

This study looks to assess the oral health status in the study subjects and to quantify the prevalence of WHO defined HIV-related oral stage 3 and 4 lesions (HIV-OL) as those conditions are indicating need for treatment independently of CD4 count.

METHODS

This quantitative screening study used both structured questionnaire and clinical examination to determine the prevalence of HIV-OL in 83 adults living with HIV randomly selected from a list of service users at a community based HIV organization.

RESULTS

The screening revealed a 40 % (95%-CI: 30-51%) prevalence of HIV-OL in this population where 71 are under Antiretroviral Therapy (ART). Most frequent HIV-OL found were persistent oral candidiasis (19% prevalence), and acute necrotizing gingivitis/stomatitis (18% prevalence) Prevalence of HIV-OL was correlating with CD4 count. Patients with multiple HIV-OL have a mean of 133 CD4 cells/μl, patients with a single HIV-OL have 327 CD4 cells/μl and patients without HIV-OL do have a mean of 457CD4 cells/μl (ANOVA-p=0.002). 6 of 12 patients not taking ART yet were found to have stage 3 or 4 HIV-OL. 46 (55%) of the study population had poor or very poor oral hygiene and 29 (35%) had never had an oral examination, 36 (43%) had attended only for extraction. Only 4 of 54 patients who had previously accessed oral health care have revealed their HIV status to the dentist at that time.

CONCLUSIONS

Wider access to oral healthcare is required for people living with HIV in Kathmandu Valley/Nepal. In this setting HIV-OL are still an important consideration in assessing patients living with HIV, which can have decisive therapeutic implications. Stage 3 and 4 conditions are, independently of CD4 count, indication to start ART without delay in people living with HIV.

Genome subtraction for the identification of potential antimicrobial targets in Xanthomonas oryzae pv. oryzae PXO99A pathogenic to rice

In pathogenic bacteria, identification of essential proteins which are non-homologous to the host plants represents potential antimicrobial targets. We applied subtractive genomics approach for the identification of novel antimicrobial targets in Xanthomonas oryzae pv. oryzae PXO99A, the causative agent of bacterial blight in rice. Comparative analysis was performed through BLAST available with the NCBI. The analysis revealed that 27 essential protein sequences out of 4,988 sequences of X. oryzae pv. oryzae PXO99A are non-homologous to Oryza sativa. Subsequent analysis of 27 essential proteins revealed their involvement in different metabolic activities such as transport activity, DNA binding, structural constituent of ribosome, cell division, translation, and plasma membrane. These 27 proteins were analyzed for virulence and novelty and out of 27, three essential non-homologous proteins were found to be the novel antimicrobial targets.

Expression, purification and crystallization of a dye-decolourizing peroxidase from Dictyostelium discoideum

Dye-decolourizing peroxidases are haem-containing peroxidases with broad substrate specificity. Using H2O2 as an electron acceptor, they efficiently decolourize various dyes that are of industrial and environmental relevance, such as anthraquninone- and azo-based dyes. In this study, the dye-decolourizing peroxidase DdDyP from Dictyostelium discoideum was overexpressed in Escherichia coli strain Rosetta(DE3)pLysS, purified and crystallized using the vapour-diffusion method. A native crystal diffracted to 1.65 Å resolution and belonged to space group P4(1)2(1)2, with unit-cell parameters a = b = 141.03, c = 95.56 Å, α = β = γ = 90°. The asymmetric unit contains two molecules.

The effect of (NH4)2Sx passivation on the (311)A GaAs surface and its use in AlGaAs/GaAs heterostructure devices

We have studied the efficacy of (NH4)2Sx surface passivation on the (311)A GaAs surface. We report XPS studies of simultaneously-grown (311)A and (100) heterostructures showing that the (NH4)2Sx solution removes surface oxide and sulfidizes both surfaces. Passivation is often characterized using photoluminescence measurements; we show that while (NH4)2Sx treatment gives a 40-60 ×  increase in photoluminescence intensity for the (100) surface, an increase of only 2-3 ×  is obtained for the (311)A surface. A corresponding lack of reproducible improvement in the gate hysteresis of (311)A heterostructure transistor devices made with the passivation treatment performed immediately prior to gate deposition is also found. We discuss possible reasons why sulfur passivation is ineffective for (311)A GaAs, and propose alternative strategies for passivation of this surface.

Richard III -- the final act

On 4 February 2013 experts confirmed that the remains of the last English king to die in battle were found under a council car park in Leicester, England. Richard III, the last Plantagenet king, wore the crown from 1483 until his untimely death in 1485. There have been many myths published about him, even one with a dental reference. This paper explores what dentistry was like at the time of Richard III, reveals the truth behind the myths and sees how the University of Leicester's findings about his dentition and skull has provided an insight into his identification, lifestyle and final moments.