In this colloquia review we discuss methods for thermal transport calculations for nanojunctions connected to two semi-infinite leads served as heat-baths. Our emphases are on fundamental quantum theory and atomistic models. We begin with an introduction of the Landauer formula for ballistic thermal transport and give its derivation from scattering wave point of view. Several methods (scattering boundary condition, mode-matching, Piccard and Caroli formulas) of calculating the phonon transmission coefficients are given. The nonequilibrium Green's function (NEGF) method is reviewed and the Caroli formula is derived. We also give iterative methods and an algorithm based on a generalized eigenvalue problem for the calculation of surface Green's functions, which are starting point for an NEGF calculation. A systematic exposition for the NEGF method is presented, starting with the fundamental definitions of the Green's functions, and ending with equations of motion for the contour ordered Green's functions and Feynman diagrammatic expansion. In the later part, we discuss the treatments of nonlinear effects in heat conduction, including a phenomenological expression for the transmission, NEGF for phonon-phonon interactions, molecular dynamics (generalized Langevin) with quantum heat-baths, and electron-phonon interactions. Some new results are also shown. We also briefly review the experimental status of the thermal transport measurements in nanostructures.PACS. 05.60.Gg quantum transport -44.10.+i heat conduction -65.80.+n thermal properties of small particles, nanocrystals, and nanotubes

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The formation and ecological roles of sterile flowers in flowering plants are interesting issues in floral biology and evolution. Here, we investigated the morphological and anatomical characteristics of both fertile and sterile flowers of Viburnum macrocephalum f. keteleeri, a self-incompatible and insect-pollinated shrub, during different developmental stages of flowers. In addition, pollinator visitation rates and fruit set were determined in intact inflorescences and those with sterile flowers removed. The results indicate that sterile and fertile flowers were developmentally similar during early developmental stages, and that development of the flower types diverged about 15 days before flowering. In addition, pollinator visitation rates, number of pollen grains on stigmas and fruit set were significantly higher in inflorescences with sterile flowers than those without sterile flowers. The results suggest that sterile flowers of this species evolved from fertile flowers under long-term selective pressure, and play a crucial role in enhancing reproductive success through effectively attracting pollinators to the plant and thus enhancing fruit set.

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We isolated multiple copies of mariner-like element (MLE) from the pink bollworm (PBW), Pectinophora gossypiella, a key lepidopteran cotton pest. Although all the MLE sequences contain multiple mutations accumulated in their transposase coding region, the consensus sequence revealed a putative ancestral transposase encoding 339 amino acid residues with a D,D(34)D motif, and 36 bp inverted terminal repeats, belonging to the cecropia subfamily, and most similar to the MLE found in Antheraea species. Examining six different pink bollworm populations, we conclude that the MLE in PBW described in this study are ancient and are undergoing the process of accumulating inactivating mutations. This conclusion is supported by the patterns of polymorphisms revealed by genomic Southern hybridization, transposable element displays, and sequences from multiple MLE.

We identified two different groups of piggyBac-like elements (PLE) in the tobacco budworm, Heliothis virescens, and named them HvPLE1 and HvPLE2. An intact copy of HvPLE1 revealed the characteristics of PLE: inverted terminal repeats, inverted subterminal repeats, and an open reading frame encoding transposase, whereas other HvPLE1 copies and all the HvPLE2 copies carried disruptive mutations in the region encoding transposase. We also identified none to two bands per genome hybridized to a probe of Trichoplusia ni piggyBac in genomic Southern blotting, which are different from HvPLE1 or HvPLE2. Analysis of the sequences of multiple copies of HvPLE1 and HvPLE2 suggests that the PLEs are closely related to the T. ni piggyBac, of relatively young age, and independently entered the H. virescens genome.

A transgenic line of the pink bollworm, Pectinophora gossypiella, a key lepidopteran cotton pest, was generated previously using the piggyBac transposon IFP2 from Trichoplusia ni. Here we identified an endogenous piggyBac-like element (PLE), designated as PgPLE1, in the pink bollworm. A putatively intact copy of PgPLE1 (PgPLE1.1) presents the canonical features of PLE: inverted terminal repeats with three C/G residues at the extreme ends, inverted subterminal repeats, TTAA target site and an open reading frame encoding transposase with 68% similarity to IFP2. Vectorette PCR revealed large variation in the insertion sites of PgPLE1 amongst worldwide populations, indicating the potential mobility of PgPLE1. The PgPLE1 was undetectable in the genome of Pectinophora endema, implying the recent invasion of PgPLE1 after the divergence of these two closely related species.