There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.

The Chemistry and Applications of Metal-Organic Frameworks

This paper presents cosmological results based on full-mission Planck observations of temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation. Our results are in very good agreement with the 2013 analysis of the Planck nominal-mission temperature data, but with increased precision. The temperature and polarization power spectra are consistent with the standard spatially-flat 6-parameter ΛCDM cosmology with a power-law spectrum of adiabatic scalar perturbations (denoted “base ΛCDM” in this paper). From the Planck temperature data combined with Planck lensing, for this cosmology we find a Hubble constant, H0 = (67.8 ± 0.9) km s-1Mpc-1, a matter density parameter Ωm = 0.308 ± 0.012, and a tilted scalar spectral index with ns = 0.968 ± 0.006, consistent with the 2013 analysis. Note that in this abstract we quote 68% confidence limits on measured parameters and 95% upper limits on other parameters. We present the first results of polarization measurements with the Low Frequency Instrument at large angular scales. Combined with the Planck temperature and lensing data, these measurements give a reionization optical depth of τ = 0.066 ± 0.016, corresponding to a reionization redshift of . These results are consistent with those from WMAP polarization measurements cleaned for dust emission using 353-GHz polarization maps from the High Frequency Instrument. We find no evidence for any departure from base ΛCDM in the neutrino sector of the theory; for example, combining Planck observations with other astrophysical data we find Neff = 3.15 ± 0.23 for the effective number of relativistic degrees of freedom, consistent with the value Neff = 3.046 of the Standard Model of particle physics. The sum of neutrino masses is constrained to ∑ mν < 0.23 eV. The spatial curvature of our Universe is found to be very close to zero, with | ΩK | < 0.005. Adding a tensor component as a single-parameter extension to base ΛCDM we find an upper limit on the tensor-to-scalar ratio of r0.002< 0.11, consistent with the Planck 2013 results and consistent with the B-mode polarization constraints from a joint analysis of BICEP2, Keck Array, and Planck (BKP) data. Adding the BKP B-mode data to our analysis leads to a tighter constraint of r0.002 < 0.09 and disfavours inflationarymodels with a V(φ) ∝ φ2 potential. The addition of Planck polarization data leads to strong constraints on deviations from a purely adiabatic spectrum of fluctuations. We find no evidence for any contribution from isocurvature perturbations or from cosmic defects. Combining Planck data with other astrophysical data, including Type Ia supernovae, the equation of state of dark energy is constrained to w = −1.006 ± 0.045, consistent with the expected value for a cosmological constant. The standard big bang nucleosynthesis predictions for the helium and deuterium abundances for the best-fit Planck base ΛCDM cosmology are in excellent agreement with observations. We also constraints on annihilating dark matter and on possible deviations from the standard recombination history. In neither case do we find no evidence for new physics. The Planck results for base ΛCDM are in good agreement with baryon acoustic oscillation data and with the JLA sample of Type Ia supernovae. However, as in the 2013 analysis, the amplitude of the fluctuation spectrum is found to be higher than inferred from some analyses of rich cluster counts and weak gravitational lensing. We show that these tensions cannot easily be resolved with simple modifications of the base ΛCDM cosmology. Apart from these tensions, the base ΛCDM cosmology provides an excellent description of the Planck CMB observations and many other astrophysical data sets.

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Planck 2015 results - XIII. Cosmological parameters

Background: Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer. Methods: The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Gr...

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2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer.

Applications such as high throughput assays (drug development,genomic screening, and clinical diagnostic assays) or fluorescencemicroscopy require highly sensitive detection of low concentrationanalytes, with many analyses performed in a short period of timeand without preliminary purification of the sample.

/pdf/stable-lanthanide-luminescence-agents-highly-emissive-in-10x80u0xw3.pdf

Stable Lanthanide Luminescence Agents Highly Emissive in Aqueous Solution: Multidentate 2-Hydroxyisophthalamide Complexes of

Metal-organic frameworks (MOFs) constructed with M(0) nodes are attractive targets due to the potential reactivity of these lowvalent metals, but examples of these MOFs remain exceedingly rare. The rational design of three-dimensional MOFs with Pd(0) and Pt(0) nodes using tetratopic phosphine ligands is reported. Five new MOFs have been synthesized by systematic variation of the phosphine ligands and metal precursors employed, and these represent the first examples of MOFs constructed using phosphine-metal bonds as the only structural component. The MOFs display solid-state luminescence, with emission maxima that are significantly red-shifted compared to Pd(PPh 3 ) 4 . In addition, a Rh(I) low valent coordination solid based on the same linker design is reported, which displays solid-state luminescence that is not observed for the molecular analogue.

Metal-Organic Frameworks with Zero and Low Valent Metal Nodes Connected by Tetratopic Phosphine Ligands.

In two studies using the dexamethasone suppression test (DST) to evaluate the efficacy of newer antidepressants in depressed outpatients, the authors found a DST nonsuppression rate of 13% (11 of 86 patients). Thirty-three of the DST suppressors received an antidepressant and 42 received placebo; the drug-treated group showed a significant therapeutic response. The low rate of DST nonsuppression in these depressed outpatients, a finding consistent with that of other investigators, does not confirm or refute reports that these patients are relatively resistant to placebo in comparison with active medication. The authors recommend that DST results not be used as selection criteria in studies assessing newer therapies for depressed outpatients.

DST results in nonpsychotic depressed outpatients.

(1) To examine the association between vocal fold paresis/paralysis (VFP) and poor swallowing outcomes in a thoracic surgery cohort at the population level, and (2) to assess utilization of ENT/speech-language pathology intervention in these cases. The National Inpatient Sample (NIS) represents a 20% stratified sample of discharges from US hospitals. Using ICD-9 codes, discharges undergoing general thoracic surgical procedures between 2008 and 2013 were identified in the NIS. Sub-cohorts of discharges with VFP and those who utilized ENT/SLP services were also identified. Weighted logistic regression models were used to compare binary outcomes such as dysphagia, aspiration pneumonia, and other complications; generalized linear models with generalized estimating equations (GEE) were used to compare total hospital costs and length of stay (LOS). We identified a weighted estimate of 673,940 discharges following general thoracic surgery procedures. The weighted frequency of VFP was 3738 (0.55%). Compared to those without VFP, patients who discharged with VFP had increased odds of dysphagia (6.56, 95% CI 5.07–8.47), aspiration pneumonia (2.54, 95% CI 1.74–3.70), post-operative tracheotomy (3.10, 95% CI 2.16–4.45), and gastrostomy tube requirement (2.46, 95% CI 1.66–3.64). Discharges with VFP also had a longer length of stay and total hospital costs. Of the discharges with VFP, 15.7% received ENT/SLP intervention. VFP after general thoracic procedures is associated with negative swallowing-related health outcomes and higher costs. Despite these negative impacts, most patients with VFP do not receive ENT/SLP intervention, identifying a potential opportunity for improving adverse swallowing-related outcomes.

Seth M. Cohen

Papers

Stable Lanthanide Luminescence Agents Highly Emissive in Aqueous Solution: Multidentate 2-Hydroxyisophthalamide Complexes of

Metal-Organic Frameworks with Zero and Low Valent Metal Nodes Connected by Tetratopic Phosphine Ligands.

DST results in nonpsychotic depressed outpatients.

Vocal Fold Paralysis/Paresis as a Marker for Poor Swallowing Outcomes After Thoracic Surgery Procedures

polyMOF Formation from Kinked Polymer Ligands via ortho‐Substitution