1,019 research outputs found
Electrodeposition from supercritical fluids
Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also discuss possible applications for supercritical fluid electrodeposition and suggest some key developments that are required to take the field to the next stage
Metal Abundance Calibration of the Ca II Triplet Lines in RR Lyrae Stars
The GAIA satellite is likely to observe thousands of RR Lyrae stars within a
small spectral window, between 8470A and 8750A, at a resolution of 11,500. In
order to derive the metallicity of RR Lyrae stars from Gaia, we have obtained
numerous spectra of RR Lyrae stars at a resolution of 35,000 with the Apache
Point Observatory 3.5 m echelle spectrograph. We have correlated the Ca II
triplet line strengths with metallicity as derived from Fe II abundances,
analogous to Preston's (1959) use of the Ca II K line to estimate the
metallicity of RR Lyrae stars. The Ca II line at 8498A is the least blended
with neighboring Paschen lines and thus provides the best correlation.Comment: Accepted for publication in Astrophysics & Space Scienc
Discovery of a nonyrast Kπ=8+ isomer in Dy162, and the influence of competing K-mixing mechanisms on its highly forbidden decay
The Gd160(Be9,α3n)Dy162 reaction has been used to study high-spin states in Dy162. Pulsed beam conditions were utilized for enhanced isomer sensitivity. An isomer at 2188.1(3) keV with a half-life of 8.3(3) μs has been discovered and assigned Kπ= 8+ with a two-quasineutron configuration. Among 11 γ-ray decay branches, an E2, ΔK=8 transition to the ground-state band was observed with a reduced hindrance of fν=35, agreeing well with systematics correlating fν with the product of the valence neutron and proton numbers (NpNn) over an extended N,Z range. Small deviations from NpNn dependence are analyzed for a range of two-quasiparticle isomer decays and interpreted as arising from a weak dependence on the isomer excitation energy relative to the yrast line
Embryonic expression and cloning of the murine GATA-3 gene.
We describe the embryonic expression pattern as well as the cloning and initial transcriptional regulatory analysis of the murine (m) GATA-3 gene. In situ hybridization shows that mGATA-3 mRNA accumulation is temporally and spatially regulated during early development: although found most abundantly in the placenta prior to 10 days of embryogenesis, mGATA-3 expression becomes restricted to specific cells within the embryonic central nervous system (in the mesencephalon, diencephalon, pons and inner ear) later in gestation. GATA-3 also shows a restricted expression pattern in the peripheral nervous system, including terminally differentiating cells in the cranial and sympathetic ganglia. In addition to this distinct pattern in the nervous system, mGATA-3 is also expressed in the embryonic kidney and the thymic rudiment, and further analysis showed that it is expressed throughout T lymphocyte differentiation. To begin to investigate how this complex gene expression pattern is elicited, cloning and transcriptional regulatory analyses of the mGATA-3 gene were initiated. At least two regulatory elements (one positive and one negative) appear to be required for appropriate tissue-restricted regulation after transfection of mGATA-3-directed reporter genes into cells that naturally express GATA-3 (T lymphocytes and neuroblastoma cells). Furthermore, this same region of the locus confers developmentally appropriate expression in transgenic mice, but only in a subset of the tissues that naturally express the gene
Observations on quasi-uniform products
AbstractWe prove that any product of quotient maps in the category of quasi-uniform spaces and quasi-uniformly continuous maps is a quotient map. We also show that a quasi-uniformly continuous map from a product of quasi-uniform spaces into a quasi-pseudometric T0-space depends on countably many coordinates.Furthermore we characterize those quasi-uniformities that are unique in their quasi-proximity class and prove that this property is preserved under arbitrary products in the category of quasi-uniform spaces
Participatory Evaluation of Resilient Potato Varieties in Climate-Smart Villages of Lushoto in Tanzania
This three-year study conducted by the International Potato Centre (CIP) in collaboration with
Selian Agricultural Research Institute (SARI) was based on demand by Lushoto farmers
through the CGIAR Research Program on Climate Change, Agriculture and Food Security
(CCAFS). This participatory action research (PAR) was aimed at developing more resilient
potato varieties that can grow in both long and short rainy seasons and give higher yields. The
approach involved training-of-trainers (ToT) and participatory varietal selection (PVS)
experiments. The ToT comprised five training events using modules. Three training events
were done in the long rainy season and two in the subsequent short rainy season. The topics
covered in the first round of training were on integrated crop management, from land
preparation to seed storage. The second round of training was participant-driven whereby topics
emerged from the first training. A total of twenty-one participants representing farmers,
extension services and local non-governmental organizations were trained. The training was
supported by field experiments using the CIP Mother and Baby Trials model. The trials were
carried out in five villages: Kwesine, Boheloi, Maringo, Kwekitui and Milungui. Experimental
materials comprised six advanced and heat tolerant clones from CIP (CIP390478.9,
CIP388767.1, CIP392797.22, CIP300055.32, CIP398208.29 and CIP397073.7), two local
varieties (Kidinya and Obama), an improved variety recently registered in Tanzania (Asante)
and a popular farmer’s variety but registered in Kenya (Shangii). A cross-analysis of field and
culinary data combining quantitative and qualitative assessments from the three seasons of field
evaluations showed a certain consistency in the high yielding ability and acceptability of four
genotypes, namely Asante, Shangii, CIP392797.22 and CIP398208.29. The two clones were
then named by farmers and proposed for official release while Shangii was proposed for
registration for commercial use
Innovating and optimizing in public organizations: does more become less?
To enhance public service performance (PSP), public organizations are challenged to
optimize and innovate their processes, techniques, policies and services. But can
public organizations go too far when innovating and optimizing? Based on survey
data from Dutch water authorities, we show that optimization initially contributes
more to PSP than innovation, but its contribution is curvilinear: the impact of
optimization becomes smaller the more optimization is conducted. The relation
between innovation and PSP is, however, linear. Based on additional qualitative
data, we show that ambidextrous water authorities run less risk of over-optimizing
and use integrative strategies to deal with innovation-optimization tensions
Genes in the postgenomic era
We outline three very different concepts of the gene - 'instrumental', 'nominal', and 'postgenomic'. The instrumental gene has a critical role in the construction and interpretation of experiments in which the relationship between genotype and phenotype is explored via hybridization between organisms or directly between nucleic acid molecules. It also plays an important theoretical role in the foundations of disciplines such as quantitative genetics and population genetics. The nominal gene is a critical practical tool, allowing stable communication between bioscientists in a wide range of fields grounded in well-defined sequences of nucleotides, but this concept does not embody major theoretical insights into genome structure or function. The post-genomic gene embodies the continuing project of understanding how genome structure supports genome function, but with a deflationary picture of the gene as a structural unit. This final concept of the gene poses a significant challenge to conventional assumptions about the relationship between genome structure and function, and between genotype and phenotype
Effect of radiofrequency denervation on pain intensity among patients with chronic lowback pain the mint randomized clinical trials
IMPORTANCE Radiofrequency denervation is a commonly used treatment for chronic low back pain, but high-quality evidence for its effectiveness is lacking. OBJECTIVE To evaluate the effectiveness of radiofrequency denervation added to a standardized exercise program for patients with chronic low back pain. DESIGN, SETTING, AND PARTICIPANTS Three pragmatic multicenter, nonblinded randomized clinical trials on the effectiveness of minimal interventional treatments for participants with chronic low back pain (Mint study) were conducted in 16 multidisciplinary pain clinics in the Netherlands. Eligible participants were included between January 1, 2013, and October 24, 2014, and had chronic low back pain, a positive diagnostic block at the facet joints (facet joint trial, 251 participants), sacroiliac joints (sacroiliac joint trial, 228 participants), or a combination of facet joints, sacroiliac joints, or intervertebral disks (combination trial, 202 participants) and were unresponsive to conservative care. INTERVENTIONS All participants received a 3-month standardized exercise program and psychological support if needed. Participants in the intervention group received radiofrequency denervation as well. This is usually a 1-Time procedure, but the maximum number of treatments in the trial was 3. MAIN OUTCOMES AND MEASURES The primary outcomewas pain intensity (numeric rating scale, 0-10; whereby 0 indicated no pain and 10 indicated worst pain imaginable) measured 3 months after the intervention. The prespecified minimal clinically important difference was defined as 2 points or more. Final follow-up was at 12 months, ending October 2015. RESULTS Among 681 participants who were randomized (mean age, 52.2 years; 421 wom
Two chemically distinct root lignin barriers control solute and water balance.
Lignin is a complex polymer deposited in the cell wall of specialised plant cells, where it provides essential cellular functions. Plants coordinate timing, location, abundance and composition of lignin deposition in response to endogenous and exogenous cues. In roots, a fine band of lignin, the Casparian strip encircles endodermal cells. This forms an extracellular barrier to solutes and water and plays a critical role in maintaining nutrient homeostasis. A signalling pathway senses the integrity of this diffusion barrier and can induce over-lignification to compensate for barrier defects. Here, we report that activation of this endodermal sensing mechanism triggers a transcriptional reprogramming strongly inducing the phenylpropanoid pathway and immune signaling. This leads to deposition of compensatory lignin that is chemically distinct from Casparian strip lignin. We also report that a complete loss of endodermal lignification drastically impacts mineral nutrients homeostasis and plant growth
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