Lipid conformational nomenclature: a general method.

We propose a conformational nomenclature for amphiphilic lipid molecules that is general and compatible with the stereospecific numbering scheme, in contrast to earlier methods in which discrepancies with the sn-scheme lead to contradictory assignments of the absolute configuration of the system. The present method can be rationally extended to different classes of lipids, both natural and synthetic. It is simple and provides a convenient framework for conformational studies on widely varying classes of lipids.     

Improvement of Early Maturing and Climate Resilient Chickpea (<i>Cicer arietinum</i> L.) Cultivars Suitable for Multiple Environments in Bangladesh

Ensuring food security for the rapidly increasing population and changing climatic scenarios are requisites for exploiting the genetic divergence of food crops. A study was undertaken to sort out an early maturing chickpea variety for fitting easily between rice-rice cropping systems in the Eastern Indo-Gangetic Plain of Bangladesh. The trial was comprised of eight elite lines of chickpea and executed at various localities in Bangladesh from 2014– 15 to 2017–18. The result explored the chickpea genotype, BARI Chola-11 remained superior to the rest of the elite genotypes for having a short maturity period (100–106 days), and lesser days to 50% flowering (47– 55 days). The same genotype was recorded to have robust vegetative and reproductive yield attributes including plant height (49–57 cm), podsplant⁻¹ (37–50), and optimum 100 seed weight (19.5–20.6 g). Owing to better yield attributes, BARI Chola-11 resulted in the maximum seed yield (1200–1500 kg ha⁻¹ ) of chickpea and might be recommended for general adoption in the region for boosting nutritional security status through improved productivity under changing climate.     

Expression of an Arabidopsis potassium channel gene in guard cells.

The Arabidopsis thaliana KAT1 cDNA encodes a voltage-gated inward-rectifying K+ channel. A KAT1 genomic DNA clone was isolated and sequenced, and a 5' promoter and coding sequences containing eight introns were identified. Reporter gene analysis of transgenic plants containing the KAT1 promoter fused to bacterial beta-glucuronidase showed robust beta-glucuronidase activity primarily in guard cells.     

Oxygen mass transfer in a bubble column bioreactor containing lysed yeast suspensions

Summary Liquid-phase volumetric oxygen transfer coefficients were evaluated in a bubble column containing yeast suspensions, using the instationary oxygen absorption method and a polarographic oxygen electrode. The electrode time lag was found to be independent of both the system studied and the operating conditions. The volumetric oxygen mass transfer coefficients k _L a could be reasonably predicted by calculating k _L from the equation derived by Bhavaraju et al. or the empirical equation of Calderbank and Moo-Young and a from the experimental gas hold-up values.Nomenclature a Exponent in Eq.6 or specific gas-liquid interfacial area based on reactor volume m - b Exponent in Eq. 6 - C Constant in Eq 6 or oxygen concentration in the liquid phase g/ml - C ^* Equilibrium oxygen concentration g/ml - C ₀ Oxygen concentration in the liquid phase at t=0 g/ml - C _E Oxygen concentration as determined by the polarographic electrode g/ml - D _B Bubble equivalent diameter mm - D _l Oxygen diffusivity in the liquid phase m²/s - g Acceleration of gravity m/s² - K Consistency index Pasⁿ - K _L Liquid-phase mass transfer coefficient m/s - n Power law exponent - Pe _sw Peclet number based on bubble swarm velocity - S _C Schmidt number - Sh Sherwood number - i Time s - U _B Bubble rise velocity in infinite medium m/s - U _g Superficial air velocity based on column cross-sectional area m/s - U _sw Bubble swarm velocity defined by Eq.15 m/s - Y _MSW Mass transfer coeficient correction factor for mobile interfaces in pseudo-plastic fluids Eq. 7 - Y _MSW Mass transfer coefficient correction factor for immobile interface in pseudo-plastic fluids Eq. 8 Greek letters _l Density of liquid g/ml - _sus Density of unaerated suspension g/ml - _{wet cell} Density of yeast wet cells g/ml - _l Viscosity of the liquid Pas - _app Apparent viscosity of power law fluid Pas - _E Electrode time lag s - _l Time lag due to resistance of the gas-liquid interface s - _g Gas hold-up, volume fraction occupied by the gas phase - _l Liquid hold-up - _c Wet cell volume fraction     

Hereditary heat-labile hexosaminidase B: its implication for recognizing Tay-Sachs genotypes

Two pairs of alleles, at the two loci of hexosaminidase (HEX), were found to segregate in an Arab inbred family: the normal and the mutant Tay-Sachs (TSD) alleles of HEX A, and the normal and a mutant allele of HEX B. Since the mutant HEX B is heat labile, no reliable identification of TSD genotypes can be obtained in its presence, as long as the proportions of HEX A and B are estimated by the routinely used heat-inactivation method. The genotypes may be correctly identified in such cases by separation of the two isoenzymes on ion-exchange chromatography, estimating their individual activities, and calculating the ratio between them. Of the nine genotype combinations possible with these two pairs of alleles, five have been identified in the reported family by this procedure.     

Deuterated phospholipids as nonperturbing components for Raman studies of biomembranes.

The deuterated phospholipid, 1,2-dipalmitoyl-d62-phosphatidylcholine is shown by Raman spectroscopic measurements to be useful for obtaining information concerning phospholipid conformation in complex phospholipid and lipidprotein mixtures. The Raman bands of the deuterated phospholipid are assigned, and the sensitivity of these vibrational modes to conformational changes in the bilayer is demonstrated. Deuteration of the alkyl chains reveals the CH vibrations of the head group. A change in these bands is observed at the melting temperature and is assigned to alteration of the glycerol backbone conformation upon melting.     

Internuclear Genetic Transfer in Dikaryons of SCHIZOPHYLLUM COMMUNE. II. Direct Recovery and Analysis of Recombinant Nuclei

The recessive gene, mound (mnd), allows the appearance of globose masses of compacted hyphae. Dikaryons of Schizophyllum commune that are heteroallelic for mnd [(mosaic dikaryons: (mnd + mnd(+))] have been successfully dedikaryotized in cholate-containing medium in order to recover the component nuclear types directly. The relative proportion of the two recovered monokaryotic types shows in all cases a marked deviation from 1:1. Hyphae from nonmound mycelial regions yield monokaryotic types identical to those originally used to form the dikaryons. In hyphae from mound-forming regions, however, homoallelism of the mnd allele has been demonstrated; the nuclear type that formerly contained the mnd(+) allele acquired a mnd allele.-The process of internuclear transfer or recombination is unaccompanied by the simultaneous alteration of any additional genetic markers carried by the recipient nucleus. The newly acquired mnd allele segregates in Mendelian fashion in subsequent outcrosses and appears to be chromosomally located. A novel process of somatic recombination, with several features distinct from classical parasexual mitotic recombination, appears to be in operation.     

The Wadi Natrun: Chemical composition and microbial mass developments in alkaline brines of Eutrophic Desert Lakes

Six lakes of the Wadi Natrun, Egypt, were studied with respect to the chemical composition of their brines and the occurrence of microbial mass developments. All investigated lakes showed pH values of approximately 11 and a total salt content of generally more than 30%. The main components were sulfate, carbonate, chloride, sodium, and minor amounts of potassium. Only traces of magnesium and calcium were present, but unusually high concentrations of organic carbon compounds, nitrogen compounds, and phosphate were found. Mass developments of phototrophic sulfur bacteria, halobacteria, cyanobacteria, and green algae were observed. The functions of complete nitrogen and sulfur cycles in the alkaline brines are discussed. The properties of the lakes and their ecology are compared with data on the Dead Sea and Great Salt Lake, Utah.