Conduction States with Vanishing Dimerization in Pt Nanowires on Ge(001) Observed with Scanning Tunneling Microscopy

The low-energy electronic properties of one-dimensional nanowires formed by Pt atoms on Ge(001) are studied with scanning tunneling microscopy down to the millivolt-regime. The chain structure exhibits various dimerized elements at high tunneling bias, indicative of a substrate bonding origin rather than a charge density wave. Unexpectedly, this dimerization becomes vanishingly small when imaging energy windows close to the Fermi level with adequately low tunneling currents. Evenly spaced nanowire atoms emerge which are found to represent conduction states. Implications for the metallicity of the chains are discussed.Comment: 4 pages, 4 figure

A QTL for osteoporosis detected in an F2 population derived from White Leghorn chicken lines divergently selected for bone index

Osteoporosis, resulting from progressive loss of structural bone during the period of egg-laying in hens, is associated with an increased susceptibility to bone breakage. To study the genetic basis of bone strength, an F cross was produced from lines of hens that had been divergently selected for bone index from a commercial pedigreed White Leghorn population. Quantitative trait loci (QTL) affecting the bone index and component traits of the index (tibiotarsal and humeral strength and keel radiographic density) were mapped using phenotypic data from 372 F individuals in 32 F families. Genotypes for 136 microsatellite markers in 27 linkage groups covering ∼80% of the genome were analysed for association with phenotypes using within-family regression analyses. There was one significant QTL on chromosome 1 for bone index and the component traits of tibiotarsal and humeral breaking strength. Additive effects for tibiotarsal breaking strength represented 34% of the trait standard deviation and 7.6% of the phenotypic variance of the trait. These QTL for bone quality in poultry are directly relevant to commercial populations

Bellucia grossularioides (L.) Triana and B. dichotoma Cogn. (Melastomataceae): two important elements of flora in secondary forest succession of the central Amazon.

The aim of the comparative studies in autoecology of common secondary forest species carried out at the EMBRAPA/SHIFT experimental site near Manaus, Amazonas is to acquire a better understanding of the mechanisms responsible for the successional pathways in Terra Firme secondary forests

Characteristics of sustainable polyculture production systems on terra firme.

The combination of soil science, forestry, agronomy and biology allowed an analytical comparison of various experimental mixed culture systems. From these studies, a descriptor system was developed which allows to understand the contribution of each plant species to nutrient cycling, water distribution, litter formation, overall biomass production and crop production. This knowledge allows to combine plants so that their properties interact to form a system, which minimizes mineral losses and which regulates air humidity and water distribution and thus leads to stable crop production. The general conclusion which can be drawn after eight years of polyculture study is: a) stable productions systems for samllholder families have bee developed; b) the systems are variable; they can be adapted to the respective site conditions; c) the manager of these plantations requires a deeper understanding of the cultivation systems and an intensive dissemination of knowledge and a well develope on-farm training system for farmers

Utilization of abandoned areas in Amazonia by polycultures of perennial useful plants.

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Spatial and temporal change of the spontaneous vegetation in an agricultural fields experiment.

The objective of the SHIFT field trial carried out on an area of 17 ha at the experimental site of EMBRAPA Amazônia Ocidental near Manaus, Amazonas, Brazil, is to try out the reuse of an abandoned agricultural site by mixed cropping systems and to survey some of the most important ecological interactions between the growth of the useful plants, the spontaneous vegetation in the field, and management and site factors

Characteristics of sustainable polyculture production systems on terra firme.

The combination of soil science, forestry, agronomy and biology allowed an analytical comparison of various experimental mixed culture systems. From these studies, a descriptor system was developed which allows to understand the contribution of each plant species to nutrient cycling, water distribution, litter formation, overall biomass production and crop production. This knowledge allows to combine plants so that their properties interact to form a system, which minimizes mineral losses and which regulates air humidity and water distribution and thus leads to stable crop production. The general conclusion which can be drawn after eight years of polyculture study is: a) stable productions systems for samllholder families have bee developed; b) the systems are variable; they can be adapted to the respective site conditions; c) the manager of these plantations requires a deeper understanding of the cultivation systems and an intensive dissemination of knowledge and a well develope on-farm training system for farmers

Spatial and temporal change of the spontaneous vegetation in an agricultural field experiment.

Study carried out to endeavor to re-use an abandoned agricultural site using mixed cropping systems and to survey some of the main ecological interactions between the frowth of the useful plants, the spontaneous vegetation in the field, and management and site factors

Biomass production and mineral element supply of selected useful tropical plants.

This current investigation is part of a cooperative project of CPAA-Manaus and Hamburg University entitled "Recultivation of degraded and abandoned monocultures instable mixed cultures with special reference to soil biological factors". In this study the biomass product and the mineral element supply of selected useful tropical plants will be determined. Parallel to it the availability of nutrient element in the soil will be analyzed. These experiments may allow an evaluation, in which way a sustainable growth of the suggested plant system under the prevailing site conditions is possible.Poster 11