413 research outputs found
Chromosome assignment of two cloned DNA probes hybridizing predominantly to human sex chromosomes
In situ hybridization experiments were carried out with two clones, YACG 35 and 2.8, which had been selected from two genomic libraries strongly enriched for the human Y chromosome. Besides the human Y chromosome, both sequences strongly hybridized to the human X chromosome, with few minor binding sites on autosomes. In particular, on the X chromosome DNA from clone YACG 35 hybridized to the centromeric region and the distal part of the short arm (Xp2.2). On the Y chromosome, the sequence was assigned to one site situated in the border region between Yq1.1 and Yq1.2. DNA from clone 2.8 also hybridized to the centromeric region of the X and the distal part of the short arm (Xq2.2). On the Y, however, two binding sites were observed (Yp1.1 and Yq1.2). The findings indicate that sex chromosomal sequences may be localized in homologous regions (as suggested from meiotic pairing) but also at ectopic sites
Brane-World Gravity
The observable universe could be a 1+3-surface (the "brane") embedded in a
1+3+\textit{d}-dimensional spacetime (the "bulk"), with Standard Model
particles and fields trapped on the brane while gravity is free to access the
bulk. At least one of the \textit{d} extra spatial dimensions could be very
large relative to the Planck scale, which lowers the fundamental gravity scale,
possibly even down to the electroweak ( TeV) level. This revolutionary
picture arises in the framework of recent developments in M theory. The
1+10-dimensional M theory encompasses the known 1+9-dimensional superstring
theories, and is widely considered to be a promising potential route to quantum
gravity. At low energies, gravity is localized at the brane and general
relativity is recovered, but at high energies gravity "leaks" into the bulk,
behaving in a truly higher-dimensional way. This introduces significant changes
to gravitational dynamics and perturbations, with interesting and potentially
testable implications for high-energy astrophysics, black holes, and cosmology.
Brane-world models offer a phenomenological way to test some of the novel
predictions and corrections to general relativity that are implied by M theory.
This review analyzes the geometry, dynamics and perturbations of simple
brane-world models for cosmology and astrophysics, mainly focusing on warped
5-dimensional brane-worlds based on the Randall--Sundrum models. We also cover
the simplest brane-world models in which 4-dimensional gravity on the brane is
modified at \emph{low} energies -- the 5-dimensional Dvali--Gabadadze--Porrati
models. Then we discuss co-dimension two branes in 6-dimensional models.Comment: A major update of Living Reviews in Relativity 7:7 (2004)
"Brane-World Gravity", 119 pages, 28 figures, the update contains new
material on RS perturbations, including full numerical solutions of
gravitational waves and scalar perturbations, on DGP models, and also on 6D
models. A published version in Living Reviews in Relativit
Doubling of marine dinitrogen-fixation rates based on direct measurements
Biological dinitrogen fixation provides the largest input of nitrogen to the oceans, therefore exerting important control on the ocean’s nitrogen inventory and primary productivity. Nitrogen-isotope data fromocean sediments suggest that the marine-nitrogen inventory has been balanced for the past 3,000 years (ref. 4). Producing a balanced marine-nitrogenbudget based on direct measurements has proved difficult, however, with nitrogen loss exceeding the gain from dinitrogen fixation by approximately 200 TgNyr-1 (refs 5, 6). Here we present data from the Atlantic Ocean and show that the most widely used method of measuring oceanic N2-fixation rates underestimates the contribution of N2-fixing microorganisms (diazotrophs) relative to a newly developed method. Using molecular techniques to quantify the abundance of specific clades of diazotrophs in parallel with rates of 15N2 incorporation into particulate organic matter, we suggest that the difference between N2-fixation rates measured with the established method and those measured with the new method8 can be related to the composition of the diazotrophic community.
Our data show that in areas dominated by Trichodesmium, the established method underestimatesN2-fixation rates by an averageof 62%. We also find that the newly developed method yields N2-fixation rates more than six times higher than those from the established method when unicellular, symbiotic cyanobacteria and c-proteobacteria dominate the diazotrophic community. On the basis of average areal rates measured over the Atlantic Ocean, we calculated basin-wide N2-fixation rates of 14+/-1TgNyr-1 and 24+/-1TgNyr-1 for the established and new methods, respectively. If our findings can be extrapolated to other ocean basins, this suggests that the global marine N2-fixation rate derived from direct measurements may increase from 103+/-8TgNyr-1 to 177+/-8TgNyr-1, and that the contribution of N2 fixers other than Trichodesmium is much more significant than was
previously thought
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria
Cyanobacteria are thought to be the main N2-fixing organisms
(diazotrophs) in marine pelagic waters, but recent molecular analyses indicate
that non-cyanobacterial diazotrophs are also present and active. Existing data
are, however, restricted geographically and by limited sequencing depths. Our
analysis of 79,090 nitrogenase (nifH) PCR amplicons encoding
7,468 unique proteins from surface samples (ten DNA samples and two RNA samples)
collected at ten marine locations world-wide provides the first in-depth survey
of a functional bacterial gene and yield insights into the composition and
diversity of the nifH gene pool in marine waters. Great
divergence in nifH composition was observed between sites.
Cyanobacteria-like genes were most frequent among amplicons from the warmest
waters, but overall the data set was dominated by nifH
sequences most closely related to non-cyanobacteria. Clusters related to Alpha-,
Beta-, Gamma-, and Delta-Proteobacteria were most common and showed distinct
geographic distributions. Sequences related to anaerobic bacteria
(nifH Cluster III) were generally rare, but preponderant in
cold waters, especially in the Arctic. Although the two transcript samples were
dominated by unicellular cyanobacteria, 42% of the identified
non-cyanobacterial nifH clusters from the corresponding DNA
samples were also detected in cDNA. The study indicates that non-cyanobacteria
account for a substantial part of the nifH gene pool in marine
surface waters and that these genes are at least occasionally expressed. The
contribution of non-cyanobacterial diazotrophs to the global N2
fixation budget cannot be inferred from sequence data alone, but the prevalence
of non-cyanobacterial nifH genes and transcripts suggest that
these bacteria are ecologically significant
Maternal Occupational Exposure to Polycyclic Aromatic Hydrocarbons: Effects on Gastroschisis among Offspring in the National Birth Defects Prevention Study
Background: Exposure to polycyclic aromatic hydrocarbons (PAHs) occurs in many occupational settings. There is evidence in animal models that maternal exposure to PAHs during pregnancy is associated with gastroschisis in offspring; however, to our knowledge, no human studies examining this association have been conducted
Assessing Fish and Motile Fauna around Offshore Windfarms Using Stereo Baited Video
There remains limited knowledge of how offshore windfarm developments influence fish assemblages, particularly at a local scale around the turbine structures. Considering the existing levels of anthropogenic pressures on coastal fish populations it is becoming increasingly important for developers and environmental regulators to gain a more comprehensive understanding of the factors influencing fish assemblages. Improving our ability to assess such fish populations in close proximity to structures will assist in increasing this knowledge. In the present study we provide the first trial use of Baited Remote Underwater Stereo-Video systems (stereo BRUVs) for the quantification of motile fauna in close proximity to offshore wind turbines. The study was conducted in the Irish Sea and finds the technique to be a viable means of assessing the motile fauna of such environments. The present study found a mixture of species including bottom dwellers, motile crustaceans and large predatory fish. The majority of taxa observed were found to be immature individuals with few adult individuals recorded. The most abundant species were the angular crab (Goneplax rhomboides) and the small-spotted catshark (Scyliorhinus canicula). Of note in this study was the generally low abundance and diversity of taxa recorded across all samples, we hypothesise that this reflects the generally poor state of the local fauna of the Irish Sea. The faunal assemblages sampled in close proximity to turbines were observed to alter with increasing distance from the structure, species more characteristic of hard bottom environments were in abundance at the turbines (e.g. Homarus gammarus, Cancer pagarus, Scyliorhinus spp.) and those further away more characteristic of soft bottoms (e.g. Norwegian Lobster). This study highlights the need for the environmental impacts of offshore renewables on motile fauna to be assessed using targeted and appropriate tools. Stereo BRUVs provide one of those tools, but like the majority of methods for sampling marine biota, they have limitations. We conclude our paper by providing a discussion of the benefits and limitations of using this BRUV technique for assessing fauna within areas close to offshore windfarms
Motif Minang Kaluak Paku Kacang Balimbiang pada Busana Kasual
Minangkabau sebagai salah satu suku bangsa yang mengisi kekhasan
budaya Indonesia memiliki warisan budaya yang terpencar dalam berbagai aspek
kehidupannya. Salah satu warisan budaya adalah seni ukir. Seni ukir yang
dikembangkan dengan mengambil ide dari alam memiliki makna-makna filosofi
bagi kehidupan masyarakat Minangkabau. Semua jenis ukiran yang dipahatkan di
Rumah Gadang menunjukkan unsur penting pembentuk budaya Minangkabau
bercerminkan kepada apa yang ada di alam. Salah satu ukiran pada rumah gadang
yaitu kaluak paku. Kaluak paku adalah nama salah satu motif ukiran dalam adat
Minangkabau. Berasal dari motif gulungan (kelukan/kaluak) pada ujung tanaman
pakis (paku) yang masih muda. Ukiran kaluak paku rumah gadang melambangkan
tanggung jawab seorang lelaki dalam adat Minangkabau kepada generasi penerus,
sebagai ayah dari anak-anaknya dan sebagai mamak dari kemenakan (keponakan).
Ukiran rumah gadang kaluak paku minangkabau inilah yang menjadi sumber ide
penciptaan busana pada tugas akhir ini.
Pada Penciptaan karya ini menggunakan beberapa metode, yaitu metode
pendekatan estetis dan ergonomis, metode pengumpulan data dengan studi
pustaka, dan motode penciptaan dengan teori Gustami Sp 3 tahap 6 Langkah.
Dalam proses pembuatan karya dibutuhkan beberapa data, cara pengumpulan data
acuan berdasarkan pengumpulan data pustaka yaitu berupa buku, jurnal pada
media sosial, serta aplikasi pada smartphone seperti pinterest. Data yang
dikumpulkan yang paling utama adalah gambar bentuk visual dari ukiran tanaman
kaluak paku minangkabau dan busana kasual.
Penciptaan karya yang dihasilkan yaitu berupa 8 busana kasual. Siluet pada
kesuluruhan hasil karya yaitu memiliki siluet A yang mengembang pada bagian
bawah. Pada penciptaan karya ini menggunakan bahan utama primisima.
Perpaduan warna yang diterapkan menggunakan warna khas minangkabau yang
diambil dari warna bendera adatnya “marawa” yaitu merah, hitam, dan kuning.
Karya- karya yang dihasilkan dengan penggunaan warna tersebut sangat sesuai
dengan tema yang mengangkat ukiran rumah gadang kaluak paku minangkabau.
Kata Kunci : Minang, Kaluak Paku Kacang Balimbiang, Kasua
How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers
Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program
Prediction of Drug-Target Interactions and Drug Repositioning via Network-Based Inference
Drug-target interaction (DTI) is the basis of drug discovery and design. It is time consuming and costly to determine DTI experimentally. Hence, it is necessary to develop computational methods for the prediction of potential DTI. Based on complex network theory, three supervised inference methods were developed here to predict DTI and used for drug repositioning, namely drug-based similarity inference (DBSI), target-based similarity inference (TBSI) and network-based inference (NBI). Among them, NBI performed best on four benchmark data sets. Then a drug-target network was created with NBI based on 12,483 FDA-approved and experimental drug-target binary links, and some new DTIs were further predicted. In vitro assays confirmed that five old drugs, namely montelukast, diclofenac, simvastatin, ketoconazole, and itraconazole, showed polypharmacological features on estrogen receptors or dipeptidyl peptidase-IV with half maximal inhibitory or effective concentration ranged from 0.2 to 10 µM. Moreover, simvastatin and ketoconazole showed potent antiproliferative activities on human MDA-MB-231 breast cancer cell line in MTT assays. The results indicated that these methods could be powerful tools in prediction of DTIs and drug repositioning
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