593 research outputs found
Precision spectroscopy and density-dependent frequency shifts in ultracold Sr
By varying the density of an ultracold Sr sample from cm
to cm, we make the first definitive measurement of the
density-related frequency shift and linewidth broadening of the -
optical clock transition in an alkaline earth system. In addition, we
report the most accurate measurement to date of the Sr
optical clock transition frequency. Including a detailed analysis of systematic
errors, the frequency is () Hz.Comment: 4 pages, 4 figures, 1 table. submitte
Free-space propagation of high dimensional structured optical fields in an urban environment
Spatially structured optical fields have been used to enhance the functionality of a wide variety of systems that use
light for sensing or information transfer. As higher-dimensional modes become a solution of choice in optical
systems, it is important to develop channel models that suitably predict the effect of atmospheric turbulence on
these modes. We investigate the propagation of a set of orthogonal spatial modes across a free-space channel
between two buildings separated by 1.6 km. Given the circular geometry of a common optical lens, the orthogonal
mode set we choose to implement is that described by the Laguerre-Gaussian (LG) field equations. Our study focuses
on the preservation of phase purity, which is vital for spatial multiplexing and any system requiring full quantumstate
tomography. We present experimental data for the modal degradation in a real urban environment and draw a
comparison to recognized theoretical predictions of the link. Our findings indicate that adaptations to channel
models are required to simulate the effects of atmospheric turbulence placed on high-dimensional structured
modes that propagate over a long distance. Our study indicates that with mitigation of vortex splitting, potentially
through precorrection techniques, one could overcome the challenges in a real point-to-point free-space channel in
an urban environment
Comparison of high-specific-activity ultratrace 123/131I-MIBG and carrier-added 123/131I-MIBG on efficacy, pharmacokinetics, and tissue distribution
Metaiodobenzylguanidine (MIBG) is an enzymatically stable synthetic analog of norepinephrine that when radiolabled with diagnostic ((123)I) or therapeutic ((131)I) isotopes has been shown to concentrate highly in sympathetically innervated tissues such as the heart and neuroendocrine tumors that possesses high levels of norepinephrine transporter (NET). As the transport of MIBG by NET is a saturable event, the specific activity of the preparation may have dramatic effects on both the efficacy and safety of the radiodiagnostic/radiotherapeutic. Using a solid labeling approach (Ultratrace), noncarrier-added radiolabeled MIBG can be efficiently produced. In this study, specific activities of >1200 mCi/micromol for (123)I and >1600 mCi/micromol for (131)I have been achieved. A series of studies were performed to assess the impact of cold carrier MIBG on the tissue distribution of (123/131)I-MIBG in the conscious rat and on cardiovascular parameters in the conscious instrumented dog. The present series of studies demonstrated that the carrier-free Ultratrace MIBG radiolabeled with either (123)I or (131)I exhibited similar tissue distribution to the carrier-added radiolabeled MIBG in all nontarget tissues. In tissues that express NETs, the higher the specific activity of the preparation the greater will be the radiopharmaceutical uptake. This was reflected by greater efficacy in the mouse neuroblastoma SK-N-BE(2c) xenograft model and less appreciable cardiovascular side-effects in dogs when the high-specific-activity radiopharmaceutical was used. The increased uptake and retention of Ultratrace (123/131)I-MIBG may translate into a superior diagnostic and therapeutic potential. Lastly, care must be taken when administering therapeutic doses of the current carrier-added (131)I-MIBG because of its potential to cause adverse cardiovascular side-effects, nausea, and vomiting
Parents, children and the porous boundaries of the sexual family in law and popular culture
This article focuses on a perceived ideological overlap between popular cultural and judicial treatments of sex and conjugality that contributes to a discursive construction of parenthood and parenting. The author perceives that in both legal and popular cultural texts, there is a sense in which notions of ânaturalâ childhood are discursively constituted as being put at risk by those who reproduce outside of dominant sexual norms, and that signs of normative sexuality (typically in the form of heterosexual coupling) may be treated as a sign of safety. These ideas are rooted in ancient associations between fertility, sexuality and femininity that can also be traced in the historical development of the English language. With the help of commentators such as Martha Fineman, the article situates parents and children within a discourse of family which prioritises conjugality, with consequences for the ways in which the internal and external boundaries of families are delineated
Improved synthesis of conduritol B epoxide
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25497/1/0000038.pd
The role of pharmacists in general practice: a realist review
Background
The review was carried out review prior to evaluating and to inform our research on the clinical pharmacists in general practices pilot, a world leading initiative to improve health care delivery in England. Around 500 pharmacists are already working in general practice as part of the pilot, launched in July 2015
Objectives
The review attempts to explain the how âclinical pharmacists in general practicesâ is being implemented, what works well, what does not work so well and everything in-between.
Methods
This realist review was conducted to the RAMESES standards. Studies were identified by searching three databases, Medline, Embase and Scopus. Additional papers were gathered from reference lists, Google searches and via the find similar citations feature.
Results
A total of 83 papers and articles were initially identified from Medline (19), Embase (31) and Scopus (32). With close reading, the final review consisted of of 43 papers relating to 38 studies. Most of the research was undertaken in the field of pharmacy practice and over half of the studies investigated the perspectives of different stakeholders using questionnaires or qualitative methods.
Conclusion
The pharmacist in general practices initiative is still at an early stage of implementation, further research and more in-depth findings are still required. However, from this small number of studies, the common barriers and facilitators to the implementation can be identified. The review also lists mechanisms that will be needed to ensure the effective implementation of this initiative
Whole Methylome Analysis by Ultra-Deep Sequencing Using Two-Base Encoding
Methylation, the addition of methyl groups to cytosine (C), plays an important role in the regulation of gene expression in both normal and dysfunctional cells. During bisulfite conversion and subsequent PCR amplification, unmethylated Cs are converted into thymine (T), while methylated Cs will not be converted. Sequencing of this bisulfite-treated DNA permits the detection of methylation at specific sites. Through the introduction of next-generation sequencing technologies (NGS) simultaneous analysis of methylation motifs in multiple regions provides the opportunity for hypothesis-free study of the entire methylome. Here we present a whole methylome sequencing study that compares two different bisulfite conversion methods (in solution versus in gel), utilizing the high throughput of the SOLiDâą System. Advantages and disadvantages of the two different bisulfite conversion methods for constructing sequencing libraries are discussed. Furthermore, the application of the SOLiDâą bisulfite sequencing to larger and more complex genomes is shown with preliminary in silico created bisulfite converted reads
Nonlinear electrochemical relaxation around conductors
We analyze the simplest problem of electrochemical relaxation in more than
one dimension - the response of an uncharged, ideally polarizable metallic
sphere (or cylinder) in a symmetric, binary electrolyte to a uniform electric
field. In order to go beyond the circuit approximation for thin double layers,
our analysis is based on the Poisson-Nernst-Planck (PNP) equations of dilute
solution theory. Unlike most previous studies, however, we focus on the
nonlinear regime, where the applied voltage across the conductor is larger than
the thermal voltage. In such strong electric fields, the classical model
predicts that the double layer adsorbs enough ions to produce bulk
concentration gradients and surface conduction. Our analysis begins with a
general derivation of surface conservation laws in the thin double-layer limit,
which provide effective boundary conditions on the quasi-neutral bulk. We solve
the resulting nonlinear partial differential equations numerically for strong
fields and also perform a time-dependent asymptotic analysis for weaker fields,
where bulk diffusion and surface conduction arise as first-order corrections.
We also derive various dimensionless parameters comparing surface to bulk
transport processes, which generalize the Bikerman-Dukhin number. Our results
have basic relevance for double-layer charging dynamics and nonlinear
electrokinetics in the ubiquitous PNP approximation.Comment: 25 pages, 17 figures, 4 table
The Hardware of the ATLAS Pixel Detector Control System
The innermost part of the ATLAS (A Toroidal LHC ApparatuS) experiment will be a pixel detector, built of 1744 individual detector modules. To operate the modules, readout electronics, and other detector components, a complex power supply and control system is necessary. The specific powering and control requirements are described, along with the custom made components of our power supply and control systems. These include remotely programmable Regulator Stations, the power supply system for the optical transceivers, several monitoring units and the Interlock System
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