Molecular Exploration of Guava (Psidium guajava L.) Genome Using SSR and RAPD Markers: A Step towards Establishing Linkage Map

In the present study, molecular evaluation of two guava mapping populations (MP), MPI comprising 94 F1 progenies and MPII comprising 46 F1 progenies, was carried out using simple sequence repeat (SSR) and random amplified polymorphic DNA (RAPD) markers. A pseudo-test cross strategy was implemented where 'Kamsari' X 'Purple Local' and 'Purple Local' X 'Allahabad Safeda' were crossed, and, these showed variation in fruit quality traits such as seedstrength (hardness/softness), fruit weight, TSS and pulp color. A set of 30 RAPD markers was used for genotyping MPI while a set of 55 SSR markers was used for genotyping MPII. In case of MPI, 30 RAPD markers generated 214 scorable markers, of which 80 markers were specific to 'Kamsari', 14 markers to 'Purple Local' and the remaining 120 were intercross markers. As for MPII, 55 polymorphic SSR markers resulted in generation of 207 alleles (with a maximum of 4 alleles and a minimum of 3 alleles per locus), of which 108 alleles were specific to 'Purple Local' while 99 were specific to 'Allahabad Safeda'. Genotypic data thus generated can be further exploited for constructing genetic linkage maps and mapping complex QTLs governing fruit quality traits in guava.

Controlled release nanoparticulate matter delivery system

A controlled release nanoparticulate matter delivery system includes a plurality of thermoresponsive modules containing a respective nanoparticulate matter. Each thermoresponsive module is selectively operable in at least one of a heating mode that releases the nanoparticulate matter and a cooling mode that inhibits release of the nanoparticulate matter. A control module is in electrical communication with the plurality of thermoresponsive modules. The control module is configured to determine a temperature of each thermoresponsive module and to select the at least one heating mode and cooling mode based on the temperature. The heating and cooling mode may be selected in response to a desired dosing profile and/or a biometric condition.Board of Regents, University of Texas Syste

Tribological Properties of Novel Multi-Walled Carbon Nanotubes and Phosphorus Containing Ionic Liquid Hybrids in Grease

A continuing quest exists to develop high-performance grease capable of meeting extreme demands of high energy efficiency and durability of modern mechanical systems. In this study, multi-walled carbon nanotubes (MWCNT) and ionic liquids (IL) either singly or as a binary additive system were prepared to study the tribological performance of lithium greases under boundary lubrication condition. The combination of MWCNT and IL can benefit from their respective lubricating mechanism to minimize friction and wear. To test this hypothesis, MWCNT and IL are tested individually and compared with combined MWCNT-IL additive mixture within lithium-based greases. MWCNT-IL gelatinous hybrids were prepared by inducing physical non-covalent interactions between MWCNTs and phosphorous based ILs through ultrasonication and magnetic stirring. Four different phosphorous based ILs, Choline bis (2-ethylhexyl)-phosphate, Choline dibutyl-dithiophosphate, Methyl-tributyl-phosphonium dimethyl-phosphate, Tetra-n-butyl-phosphonium O,O-diethyl-dithiophosphate were used. Four ball tribological test configuration was used to assess wear and friction properties of fabricated greases. The lubrication mechanism of these additives was elucidated through analysis of worn surfaces using surface characterization techniques like SEM, EDS, and stereo optical microscopy. All greases that contain ionic liquid exhibited better tribological performance compared to grease with ZDDP. The maximum reduction of the coefficient of friction (COF) of 60% and wear scar diameter (WSD) reduction of 25% was observed for greases containing MWCNTs and phosphonium cation based ILs hybrids as an additive. Results indicated either worse or comparable anti-wear behavior in greases with MWCNT-IL hybrids as compared to greases that only contained IL or MWCNT. The antagonistic interaction between MWCNT and IL has been postulated to occur when MWCNT adversely interacts with IL formed tribofilms, negating the benefit from IL resulting in increased wear in greases with binary mixtures of MWCNT-IL

Genetic Diversity Analysis and Barcoding in Tuberose (Polianthes tuberosa L.) Cultivars Using RAPD and ISSR Markers

Tuberose is one of the most important bulbous ornamentals grown commercially for loose as well as cut flowers. RAPD and ISSR markers used in the study revealed 53% and 73% polymorphism, respectively, among ten tuberose varieties. Polymorphic Information Content (PIC) and Resolving Power (RP) for RAPD varied from 0.35 - 0.46 and 0.8 - 3.6, respectively, and that for ISSR was 0.36 - 0.49 and 0.91 - 4.55, respectively. The dendrogram (UPGMA), based on Jaccards co-efficient as similarity index for RAPD and ISSR, grouped ten varieties into two major clusters, and, combined RAPD-ISSR cluster analysis formed three major clusters based on their genetic relatedness/variation. PCA revealed that the spatial arrangement of these 10 cultivars was congruent with dendrogram analysis. Mantel's test indicated very good correlation, with r = 0.86 for combination of ISSR and RAPD-ISSR. To facilitate identification of tuberose cultivars, a cultivar identification diagram (CID) was developed in which seven ISSR loci could differentiate all the ten cultivars used in the study. Barcodes were developed for five cultivars released by IIHR using 57 polymorphic loci generated by 11 ISSR primers. The size of these loci ranged from 252bp to 2.2kb. These barcodes can be used as a standard reference source for quick identification of cultivars

Polymorphism analysis of six selenoprotein genes: support for a selective sweep at the glutathione peroxidase 1 locus (3p21) in Asian populations

BACKGROUND: There are at least 25 human selenoproteins, each characterized by the incorporation of selenium into the primary sequence as the amino acid selenocysteine. Since many selenoproteins have antioxidant properties, it is plausible that inter-individual differences in selenoprotein expression or activity could influence risk for a range of complex diseases, such as cancer, infectious diseases as well as deleterious responses to oxidative stressors like cigarette smoke. To capture the common genetic variants for 6 important selenoprotein genes (GPX1, GPX2, GPX3, GPX4, TXNRD1, and SEPP1) known to contribute to antioxidant host defenses, a re-sequence analysis was conducted across these genes with particular interest directed at the coding regions, intron-exon borders and flanking untranslated regions (UTR) for each gene in an 102 individual population representative of 4 major ethnic groups found within the United States. RESULTS: For 5 of the genes there was no strong evidence for selection according to the expectations of the neutral equilibrium model of evolution; however, at the GPX1 locus (3p21) there was evidence for positive selection. Strong confirmatory evidence for recent positive selection at the genomic region 3p21 in Asian populations is provided by data from the International HapMap project. CONCLUSION: The SNPs and fine haplotype maps described in this report will be valuable resources for future functional studies, for population specific genetic studies designed to comprehensively explore the role of selenoprotein genetic variants in the etiology of various human diseases, and to define the forces responsible for a recent selective sweep in the vicinity of the GPX1 locus

Enrichment of Genetic Linkage Maps and Mapping QTLs Specific to Seed Strength-Hardness/Softness-In Guava (Psidium guajava L.)

The present research focuses mainly on molecular mining and morphological evaluation of guava genome within a full-sib population and, thereby, mapping of quantitative trait loci related to fruit quality traits, viz., seed strength (hardness/softness) and average fruit weight. Linkage maps were enriched for both parental lines, 'Kamsari' and 'Purple Local' using a set of 60 RAPD markers following the pseudo-testcross strategy on a panel of 94 progeny. A total of 480 scorable markers were identified, of which 131 were specific to 'kamsari' and 28 to 'Purple Local', segregating as test cross markers, and, 321 showing intercross pattern common to both. 'Kamsari' spanned a total length of 1959.1cM with average marker interval distance of 3.93cM, while 'Purple Local' spanned a length of 1537.9cM with average marker interval distance of 3.29cM, by forming 11 linkage groups. Estimated genome length observed was 93.02% and 92.77% in 'Kamsari' and 'Purple Local', respectively. Composite Interval Mapping (CIM) was computed at significance of 0.05 and LOD threshold greater than 3.0, which led to detection of one major QTL for the trait of average fruit weight, and, four QTLs for the trait of seed strength (hardness/softness). Of these, two were major and two minor QTLs. Our study provides molecular mapping information on marker-assisted selection for improvement of guava in a breeding program

Buoyancy Driven Heat Transfer in Cavities Subjected to Thermal Boundary Conditions at Bottom Wall

Natural convection in cavities is studied numerically using a finite volume based computational procedure. The enclosure used for flow and heat transfer analysis has been bounded by adiabatic top wall, constant temperature cold vertical walls and a horizontal bottom wall. The bottom wall is subjected to uniform/sinusoidal/linearly varying temperatures. Nusselt numbers are computed for Rayleigh numbers (Ra) ranging from 103 to 107 and aspect ratios (H/L) 0.5 and 1. Air is taken as working fluid (Pr = 0.7). Results are presented in the form of stream lines, isotherm plots and average Nusselt numbers. It is observed from this study that the uniform temperature at the bottom wall gives higher Nusselt number compared to the sinusoidal and linearly varying temperature cases. The average Nusselt number increases monotonically with Rayleigh number for both aspect ratio 1 and 0.5 for bottom wall and side walls. For the case of aspect ratio 1, the average Nusselt number for a given Rayleigh number increases at the bottom wall compared to aspect ratio 0.5. However, the average Nusselt number increases as the aspect ratio decreases from 1 to 0.5 for side wall except for uniform temperature case