Sensitivity-bandwidth limit in a multi-mode opto-electro-mechanical transducer

An opto--electro--mechanical system formed by a nanomembrane capacitively coupled to an LC resonator and to an optical interferometer has been recently employed for the high--sensitive optical readout of radio frequency (RF) signals [T. Bagci, \emph{et~al.}, Nature {\bf 507}, 81 (2013)]. Here we propose and experimentally demonstrate how the bandwidth of such kind of transducer can be increased by controlling the interference between two--electromechanical interaction pathways of a two--mode mechanical system. With a proof--of--principle device \new{operating at room temperature, we achieve a sensitivity of 300 nV/Hz^(1/2) over a bandwidth of 15 kHz in the presence of radiofrequency noise, and an optimal shot-noise limited sensitivity of 10 nV/Hz^(1/2) over a bandwidth of 5 kHz. We discuss strategies for improving the performance of the device, showing that, for the same given sensitivity, a mechanical multi--mode transducer can achieve a bandwidth} significantly larger than that of a single-mode one

Comparison of Ten Metal-Doped LaFeO3 Samples on Photocatalytic Degradation of Antibiotics in Water under Visible Light: Role of Surface Area and Aqueous Phosphate Ions

Doping semiconducting oxides, such as LaFeO3 (LF), with metallic elements is a good strategy to improve the performance of photocatalysts. In this study, LF and ten different nanopowders metal-doped at the La or Fe site of LaFeO3 were evaluated in the photocatalytic degradation of ciprofloxacin (CP) and oxytetracycline (OTC). The following metals were used in the doping (mol%) process of LF: Pd 3% and 5%; Cu 10%; Mg 5%, 10%, and 20%; Ga 10%; Y 10% and 20%; and Sr 20%. The doped samples were synthetized using a citrate auto-combustion technique. From the X-ray diffraction (XRD) data, only a single crystalline phase, namely an orthorhombic perovskite structure, was observed except for trace amounts of PdO in the sample with Pd 5%. The specific surface area (SSA) ranged from 9 m(2) g(-1) (Ga 10%) to 20 m(2) g(-1) (Mg 20%). SEM images show that all samples were constituted from agglomerates of particles whose sizes ranged from ca. 20 nm (Mg 20%) to ca. 100 nm (Pd 5%). Dilute aqueous solutions (5 x 10(-6) M) prepared for both CP and OTC were irradiated for 240 min under visible-light and in the presence of H2O2 (10(-2) M). The results indicate a 78% removal of OTC with Cu 10% doped LF in a phosphate buffer (pH = 5.0). The degradation of CP is affected by pH and phosphate ions, with 78% (in unbuffered solution) and 54% (in phosphate buffer, pH = 5.0) removal achieved with Mg 10% doped LF. The reactions follow a pseudo-first order kinetic. Overall, this study is expected to deepen the assessment of photocatalytic activity by using substrates with different absorption capacities on photocatalysts

Comparative Study on Characteristics of Solid Waste Black Water in Strait Meranti Islands

The amount of solid waste at station 1 to station more than 2 type of solid waste in the Black Water Strait of each station is almost the same, where the Black Water Strait is dominated by the type of waste plastic and small pieces of wood. In Black Water Strait encountered type of waste that generally consist of plastics, paper, rubber, foam, jute sacks, leaves, and small pieces of wood. From this we can conclude that the solid waste at both stations originate from the same source ie domestic waste. The strong tidal currents provide a direct influence on the amount of solid waste that are found in every point of the study and vice versa if the lower the pressure, the current is the entry-level waste into gear tends to be decreased

Optomechanical sideband cooling of a thin membrane within a cavity

We present an experimental study of dynamical back-action cooling of the fundamental vibrational mode of a thin semitransparent membrane placed within a high-finesse optical cavity. We study how the radiation pressure interaction modifies the mechanical response of the vibrational mode, and the experimental results are in agreement with a Langevin equation description of the coupled dynamics. The experiments are carried out in the resolved sideband regime, and we have observed cooling by a factor 350 We have also observed the mechanical frequency shift associated with the quadratic term in the expansion of the cavity mode frequency versus the effective membrane position, which is typically negligible in other cavity optomechanical devices.Comment: 15 pages, 7 figure

Characterization of hydraulic mortars from archaeological complexes in Petra

In the sixth century B.C. Petra was conquered by the Nabataeans, who built an elaborated water system and turned a desert city into an artificial oasis and a prosperous centre controlling the main commercial routes of the region (100 B.C. - 100 A.D.). In 2007, it was added to UNESCO's prestigious list of World Heritage Sites, as one of the seven wonders of the world. The aim of this research is to characterize samples of mortars lining cisterns, reservoirs and pipelines collected from the archeological site of Petra, focusing in general on the identification of the possible raw materials employed and in particular on those components conferring hydraulicity. Specifically the specimens were sampled from different structures of the Great Temple (cistern and pipelines) and of the Garden and Pool Complex (cisterns and reservoir floor). A mineralogical and petrographic characterization was carried out by polarized light microscopy (PLM) observations to identify the texture and to highlight the hydraulic reaction areas, which underwent subsequently to a more detailed morphological and elemental analysis by Scanning Electron Microscopy (SEM-EDX). X-Ray Powder Diffraction analyses (XRPD) were also performed to complete the petrographic characterization, while Thermal Analyses (DTA-TGA) were carried out to classify the level of hydraulicity of each sample. The data obtained allowed us to achieve for the first time a mineralogical and petrographic characterization of the lining hydraulic mortars present in the two archaeological complexes under study and to provide preliminary hypotheses on the provenance of the raw materials employed for their production

Chemical characterisation of construction and demolitionwaste in Skopje city and its surroundings (Republic of Macedonia)

In the Republic of Macedonia, construction and demolition waste is often dumped, underestimating the potential recycling and re-use as raw materials for civil engineering works and/or cement/ceramic industries. SAMCODE (Sustainable Approach to Managing Construction and Demolition Waste) is a know-how exchange program, the focus of which is chemical characterisation in terms of major and trace elements in order to evaluate the possible Macedonian construction and demolition waste recycling. Thirty-nine waste samples were collected from different dumps in Skopje and surroundings. X-ray fluorescence analyses, carried out on powdered samples, show i) highly variable concentrations, indicative of the heterogenous nature of construction and demolition waste, and ii) high concentration in Cr, Ni, and Zn with respect to Italian, Chinese, and Dutch tolerance limits, probably due to the presence of these elements in ophiolitic rocks and sulphide-bearing deposits, used as raw material in building activity. Inductively coupled plasma mass spectrometry analyses of leachates, performed to assess the mobility of heavy metals, show significant concentrations of Cr, and to a lesser extent, Ni. Results suggest that homogenisation processes of the recycled materials should be implemented and preliminary screening of construction and demolition waste should be performed to eliminate heavy metals-bearing components

Editorial: mobile elements and plant genome evolution, comparative analyzes and computational tools

Multiple changes that occur constantly in the plant genome allow an organism to develop from a single-celled embryo to a multicellular organism. A significant part of these changes is associated with the recombination activity of numerous classes of interspersed repeats. These numerous families of interspersed repeats were often called "junk DNA" as they were not associated with vital protein-coding processes (1). Transposable elements (TEs), such as DNA transposons and retrotransposons, are the main part of these interspersed repeats (2). DNA transposons can rightfully be called true mobile elements, the activity of which can occur at any stage of cell development and manifest itself at any moment and stage of the organism's development. The diverse families of retrotransposons are highly abundant genetic elements that are related to retroviruses (3). Although retrotransposons are not true mobile elements like DNA transposons, retrotransposable elements (RTEs) form a variety of chromosomal structures, such as centromeric and telomeric regions (4), and are the main intergenic part of the genome (5). Retrotransposons move to new chromosomal locations via an RNA intermediate that is converted into extrachromosomal DNA by the encoded reverse transcriptase/RNaseH enzymes prior to reinsertion into the genome. This replicative mode of transposition can rapidly increase the copy number of elements and can thereby greatly increase plant genome size. RTEs can be clustered into distinct families each traceable to a single ancestral sequence or a closely related group of ancestral sequences. In contrast to multigene families, which are defined based on their biological role, repetitive families are usually defined based on their active ancestors (called master or source genes) and on their generation mechanisms. Over time, individual elements from repetitive families may acquire diverse biological roles. Some RTEs can provide evolutionary advantages to the host and increase their chances of survival (6). While the view that RTEs are beneficial to the host is not new, recent progress in the field has placed RTEs squarely in the center of the ongoing debate on eukaryotic evolution. To advance this important research field, in the Research Topic "Mobile Elements and Plant Genome Evolution, Comparative Analyses, and Computational Tools" we focus on the role of mobile elements with host genome evolution, discovery, and comparative and genome-wide profiling analysis of transposable elements. Different retrotransposon families, each with its own lineage and structure, may have been active at distinct phases in the evolution of a species. Retrotransposon sequences bear the promoters that bind the nuclear factors of transcription initialization and initiate RNA synthesis by polymerases II or III. In the article entitled "Additional ORFs in Plant LTR-Retrotransposons" by Vicient C.M. and Casacuberta J.M., LTR-retrotransposons that carry additional, not retrotransposon-specific open reading frames (aORF), were discovered and analyzed. This discovery expands on the unique potential of LTR-retrotransposons as evolutionary tools, as LTR-retrotransposons can be used to deliver new gene variants within a genome. The presence of a unique aORF in some characterized LTR-retrotransposon families like maize Grande, rice RIRE2, or Silene Retand, are just as typical as retrovirus gene transduction. As dispersed and ubiquitous mobile elements, the life cycle of replicative transposition leads to genome rearrangements that affect cellular function (7). Transposable elements are important drivers of species diversity and exhibit great variety in structure, size, and mechanisms of transposition, making them important putative actors in genome evolution. The research group led by Kashkush K., reported the potential impact of miniature transposable element insertions on the expression of wheat genes in different wheat species in the articles entitled "The Evolutionary Dynamics of a Novel Miniature Transposable Element in the Wheat Genome" and "Where the Wild Things Are: Transposable Elements as Drivers of Structural and Functional Variations in the Wheat Genome". The induced genetic rearrangements and insertions of mobile genetic elements in regions of active euchromatin contribute to genome alteration, which leads to "genomic stress" (8). TEmediated epigenetic modifications lead to phenotypic diversity, genetic variation, and environmental stress tolerance. TEs also contribute to genome plasticity and have a dramatic impact on the genetic diversity and evolution of the wheat genome. Using transposon display (9) and genome-wide profiling analysis of insertional polymorphisms of transposable elements (10), the authors discovered large genomic rearrangement events, such as deletions and introgressions in the wheat genome. High-throughput bioinformatics with next-generation sequencing (NGS) were key tools in these studies (11). Chromosomal rearrangements, gene duplications, and transposable element content may have a large impact on genomic structure, which could generate new phenotypic traits (7). In the article entitled "Genome Size Variation and Comparative Genomics Reveal Intraspecific Diversity in Brassica rapa", de Carvalho J.F. et al investigated structural variants and repetitive content between two accessions of Brassica rapa genomes and genome-size variation among a core collection using comparative genomics and cytogenetic approaches. Large genomic variants with a chromosome length difference of 17.6% between the A06 chromosomes of 'Z1' compared to 'Chiifu' belonging to different cultigroups of B. rapa highlighted the potential impact of differential insertion of repeat elements and inversions of large genomic regions in genome size intraspecific variability. Transposable elements are also the driving force in the evolution of epigenetic regulation and have a long-term impact on genomic instability and evolution. Remnants of RTEs appear to be overrepresented in transcription regulatory modules and other regions conserved among distantly related species, which may have implications for our understanding of their impact on speciation. RTEs are dynamic and play a role in chromosome crossing over recognition and in DNA recombination between homologous chromosomes. In the article entitled "Sequencing Multiple Cotton Genomes Reveals Complex Structures and Lays Foundation for Breeding", Wang X. et al revealed that post-polyploidization of cotton genome instability resulted in numerous genomic structural changes, DNA inversion and translocation, illegitimate recombinations, accumulation of repetitive sequences, and functional innovation accompanied by elevated evolutionary rates of genes. This genome study also revealed the evolutionary past of cotton plants, which were recursively affected by polyploidization, with a decaploidization contributing to the formation of the genus Gossypium, and a neo-tetraploidization contributing to the formation of the currently widely cultivated cotton plants. The centromere is a unique part of the chromosome that combines a conserved function with extreme variability in its DNA sequence. In the article entitled "Functional Allium fistulosum centromeres comprise arrays of a long satellite repeat, insertions of retrotransposons and chloroplast DNA" Kirov G.I., et al studied the largest plant genomic organization of the functional centromere in large-sized chromosomes in Allium fistulosum and A. cepa. Long, high-copy repeats are associated with insertions of retrotransposons and plastidial DNA, and the landscape of the centromeric regions of these species possess insertions of plastidial DNA. Among evolutionary factors, repetitive sequences play multiple roles in sex chromosome evolution. As such, the Spinacia genus serves as an ideal model to investigate the evolutionary mechanisms underlying the transition from homomorphic to heteromorphic sex chromosomes. This was studied in the article entitled "Genome-Wide Analysis of Transposable Elements and Satellite DNAs in Spinacia Species to Shed Light on Their Roles in Sex Chromosome Evolution" by Li N., et al. Major repetitive sequence classes in male and female genomes of Spinacia species and their ancestral relative, sugar beet, were elucidated in the evolutionary processes of sex chromosome evolution using NGS data. The differences of repetitive DNA sequences correlate with the formation of sex chromosomes and the transition from homomorphic sex chromosomes to heteromorphic sex chromosomes, as heteromorphic sex chromosomes existed exclusively in Spinacia tetrandra.Non peer reviewe

Expression and structural features of endoglin (CD105), a transforming growth factor beta1 and beta3 binding protein, in human melanoma.

Human endoglin (CD105) is a member of the transforming growth factor beta (TGF-beta) receptor family that binds TGF-beta1 and -beta3, but not TGF-beta2, on human endothelial cells. Immunohistochemical analyses demonstrated that CD105 is expressed on normal and neoplastic cells of the melanocytic lineage. The anti-CD105 MAb, MAEND3, stained 50, 25 and 34% of intradermal naevi, primary and metastatic melanomas investigated, respectively, and nine out of 12 melanoma cell lines. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that CD105 expressed by melanoma cells consists of a homodimeric protein with an apparent molecular weight of 180 and 95 kDa under non-reducing and reducing conditions. Cross-linking of 125I-labelled TGF-beta1 to melanoma cells, Mel 97, by disuccinimidyl suberate (DSS) demonstrated that CD105 expressed on pigmented cells binds TGF-beta1; the pattern of binding of TGF-beta1 to melanoma cells was found to be similar to that of human umbilical vein endothelial cells. The addition of exogenous, bioactive TGF-beta1 significantly (P<0.05) inhibited the growth of CD105-positive melanoma cells, Mel 97, but did not affect that of CD105-negative melanoma cells, F0-1. These data, altogether, demonstrate that CD105 is expressed on pigmented cells and might play a functionally relevant role in the biology of human melanoma cells by regulating their sensitivity to TGF-betas