Synthesis of Graphene on Gold

Here we report chemical vapor deposition of graphene on gold surface at ambient pressure. We studied effects of the growth temperature, pressure and cooling process on the grown graphene layers. The Raman spectroscopy of the samples reveals the essential properties of the graphene grown on gold surface. In order to characterize the electrical properties of the grown graphene layers, we have transferred them on insulating substrates and fabricated field effect transistors. Owing to distinctive properties of gold, the ability to grow graphene layers on gold surface could open new applications of graphene in electrochemistry and spectroscopy.Comment: 8 pages, 4 figure

A Transportation-Scheduling System for Managing Silvicultural Projects

A silvicultural project encompasses tasks such as site-level planning, regeneration, harvest, and stand-tending treatments. An essential problem in managing silvicultural projects is to efficiently schedule the operations while considering project task due dates and costs of moving scarce resources to specific job locations. Transportation costs represent a significant portion of the total operating cost. The main difficulty in developing such a management system is finding an optimal transport schedule while handling complicated constraints, such as precedence and temporal relations among project tasks, project due dates, truck routing, weather, and other operational conditions. It is well known that finding an optimal solution to these types of problems involves high computational complexity. They are usually NP-hard. For this reason, we propose to use simulated annealing -a meta-heuristic optimization method- that interacts with a network simulation model of the system in which the precedence and temporal relations among project tasks and logistics are explicitly accounted for. The approach has been tested using data provided by a silvicultural contractor located in Alabama. The results obtained solving one instance of a small size problem with five worksites showed that the best solution could be found in less than four minutes using a personal computer with a processor Pentium III (1 GHz). A good solution for a larger problem with twenty worksites was found in thirty minutes. Also a resource analysis is performed to evaluate the impact of each resource on the best solution

Evaluation of candidate gene effects and environmental factors on reproductive performance of Holstein cows

This study investigated the impact of nine polymorphisms located in the CSN2, CSN3, CSN1S1, CSN1S2, OLR1, LALBA, STAT1, DGAT1 and LGB genes, and environmental factors including calving year, season and parity on reproductive traits. The analysis was conducted on 165 Holstein-Friesian cows. Genotypes were identified using PCR-RFLP. The data of reproductive traits for four lactations were evaluated. Statistical analysis was carried out using least squares of the GLM procedures. Results indicated that CSN2 had significant effects on days before first insemination and first insemination to pregnancy interval. The SNP at the CSN3 was significantly associated with gestation length. A novel effect of OLR1-C223A on age at first calving was observed in the present study. Moreover, DGAT1 and LGB markers were significantly associated with calving interval and days before first insemination, respectively. In addition, significant environmental effects were as follows: calving year with days before first oestrus, days open, and first insemination to pregnancy interval; season with days open, first insemination to pregnancy interval, and calving interval; parity with days before first oestrus and days open. The present results and novel associations may therefore be useful and indicative for future studies on a genetic basis of cattle reproduction traits.Keywords: cattle, environmental effects, genetic marker, Holstein-Friesian, reproduction parameter

Relationship of the bovine IGF1, TG, DGAT1 and MYF5 genes to meat colour, tenderness and cooking loss

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗBovine insulin-like growth factor 1 (IGF1), thyroglobulin (TG), diacylglycerol-O-acyltransferase 1 (DGAT1) and myogenic factor 5 (MYF5) genes play an important role in the physiology of lipid and muscle metabolism and are therefore considered as candidate genes for meat production traits in farm animals. The objectives of this study were to investigate single nucleotide polymorphisms (SNPs) in IGF1, TG, DGAT1 and MYF5 genes and to evaluate whether these polymorphisms affected meat colour, tenderness and cooking loss in Holstein cattle. Initially, the SNPs were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) method. Meat samples (N= 50) derived from M. longissimus thoracis et lumborum (LTL) were used in the current study. Significant differences in variations of meat colour parameters were observed at 24 hours post-mortem. IGF1 was associated with colour parameters of a* and chroma values. In addition, effects of TG were statistically significant on L* and a* values, while, effects of MYF5 were significant on a* value. There was no association of the tested SNPs with meat pH, tenderness and cooking loss. The results presented here may give the valuable information for improving meat colour in cattle

Direct imaging of single UvrD helicase dynamics on long single-stranded DNA

Fluorescence imaging of single-protein dynamics on DNA has been largely limited to double-stranded DNA or short single-stranded DNA. We have developed a hybrid approach for observing single proteins moving on laterally stretched kilobase-sized ssDNA. Here we probed the single-stranded DNA translocase activity of Escherichia coli UvrD by single fluorophore tracking, while monitoring DNA unwinding activity with optical tweezers to capture the entire sequence of protein binding, single-stranded DNA translocation and multiple pathways of unwinding initiation. The results directly demonstrate that the UvrD monomer is a highly processive single-stranded DNA translocase that is stopped by a double-stranded DNA, whereas two monomers are required to unwind DNA to a detectable degree. The single-stranded DNA translocation rate does not depend on the force applied and displays a remarkable homogeneity, whereas the unwinding rate shows significant heterogeneity. These findings demonstrate that UvrD assembly state regulates its DNA helicase activity with functional implications for its stepping mechanism, and also reveal a previously unappreciated complexity in the active species during unwinding

Probing ultrafast energy transfer between excitons and plasmons in the ultrastrong coupling regime

Cataloged from PDF version of article.We investigate ultrafast energy transfer between excitons and plasmons in ensembles of core-shell type nanoparticles consisting of metal core covered with a concentric thin J-aggregate (JA) shell. The high electric field localization by the Ag nanoprisms and the high oscillator strength of the JAs allow us to probe this interaction in the ultrastrong plasmon-exciton coupling regime. Linear and nonlinear optical properties of the coupled system have been measured using transient absorption spectroscopy revealing that the hybrid system shows half-plasmonic and half-excitonic properties. The tunability of the nanoprism plasmon resonance provides a flexible platform to study the dynamics of the hybrid state in a broad range of wavelengths. (C) 2014 AIP Publishing LLC

Golden Horn Estuary: Description of the ecosystem and an attempt to assess its ecological quality status using various classification metrics

In this paper, we describe the pelagic and benthic ecosystem of the Golden Horn  estuary opening into the Marmara Sea. To improve the water quality of the estuary, which had long been subject to severe anthropogenic pollution (industrial, chemical, shipping),  industrial facilities were moved from the estuary in the 1980s, followed by a rehabilitation plan in the 1990s. Our results, based on chemical parameters and phytoplankton showed some signs of improvement of water conditions in the upper layer. However, macrozoobenthic findings of this study did not reflect such a recovery in bottom life.An approach to the Ecological Quality Status (EQS) assessment was performed by applying the biotic indices BENTIX, AMBI, BOPA, BO2A. Our final assessment was based on 'expert-judgements' and revealed a very disturbed overall ecosystem with 'bad' EQS for the station at the head of the estuary,  'poor' in the rest of the estuary and 'moderate' EQS only in the middle station