cssi/SciSciGPT-SciSciNet huggingface dataset:
Intramolecular Hydroalkylation as a Route to Strained Dicationic Bis(arene) [3]Ruthenocyclophanes

Base-promoted intramolecular hydroalkylation of the carbon−carbon triple bond in the ruthenium bis(arene) complexes [(p-cymene)Ru(η6-C6H5C⋮CR)][OTf]2 (1, R = Et; 2, R = Ph; OTf = O3SCF3) generates ...
Ultraviolet sources for photochemical application

This article reviews recent developments in laser and UV source technologies that are potentially useful for photochemical processes and photopolymerization processes in particular. Methods for measurement and calibration of light energy are described. A few publications on newer photochemical processes are also briefly reviewed.
The influence of tritium exposure and helium build-in on the properties of OFHC copper

Tough pitch and other high oxygen content copper alloys are known to be susceptible to hydrogen induced microstructural damage. The damage arises from the interaction of solute oxygen and oxide particles with dissolved hydrogen to form water vapor bubbles, the greatest fraction of which reside on grain boundaries. Oxygen-free high conductivity (OFHC) copper on the other hand is essentially immune to any hydrogen-induced effects. Because the oxygen content is low, no such H/sub 2/O(V) grain boundary precipitation occurs. Nor is the ductility affected to any appreciable extent even when the material is tensile tested in high pressure hydrogen. This paper summarizes the initial results of an experimental program directed towards determining the effects of the prolonged exposure of OFHC copper to a gaseous overpressure of tritium. Since this alloy is immune to any hydrogen embrittlement as described above, tritium, as a hydrogen isotope would not be expected to seriously affect its behavior. Any observed changes in microstructure or mechanical properties may therefore be ascribed to the influence of the helium born in the copper as the result of the radioactive decay of the dissolved tritium.
Acoustic and flow fields of an excited high Reynolds number axisymmetric supersonic jet

An axisymmetric perfectly expanded Mach 1.3 jet, with a Reynolds number based on the nozzle exit diameter (ReD )o f 1.1 × 10 6 and turbulent boundary layer at the nozzle exit, was excited using localized arc filament plasma actuators over a wide range of forcing Strouhal numbers (StDF ). Eight actuators distributed azimuthally were used to excite azimuthal modes m = 0–3. Far-field acoustic, flow velocity and irrotational near-field pressure were probed with a three-fold objective: (i) to investigate the broadband far-field noise amplification reported in the literature at lower speeds and ReD using excitation of m = 0 at low StDF ; (ii) to explore broadband far-field noise suppression using excitation of m = 3 at higher StDF ; and (iii) to shed some light on the connection between the flow field and the far-field noise. The broadband far-field noise amplification observed is not as extensive in amplitude or frequency range, but still sufficiently large to be of concern in practical applications. Broadband far-field noise suppression of 4–5 dB at 30 ◦ polar angle peak frequency, resulting in approximately 2 dB attenuation in the overall sound pressure level, is achieved with excitation of m =3 at StDF ∼ 0.9. Some of the noteworthy observations and inferences are (a) there is a strong correlation between the far-field broadband noise amplification and the turbulence amplification; (b) far-field noise suppression is achieved when the jet is forced with the maximum jet initial growth rate frequency thus limiting significant dynamics of structures to a shorter region close to the nozzle exit; (c) structure breakdown and dynamic interaction seem to be the dominant source of noise; and (d) coherent structures dominate the forced jet over a wide range of StDF (up to ∼ 1.31) with the largest and most organized structures observed around the jet preferred mode StDF .
Permeation through a single crystal of Zeolite NaX

Abstract Steady state permeation through a 120 μm single crystal of zeolite NaX has for the first time been observed. Each crystal was imbedded in an epoxy film, polished to expose opposite faces to feed and permeate gases, and mounted in an apparatus with pmol/s permeation rate sensitivity. Permeation was constrained to occur by an intracrystalline diffusion mechanism, confirmed by temperature dependence and selectivity measurements. Rates decreased at higher temperatures due to opposing sorption and diffusion effects. Intracrystalline butane diffusivity at 25°C was 3 x 10 −4 cm 2 /sec, in agreement with other methods. Anomalously long time lags for approach to steady state are explained by a transition between two states of the zeolite, differing in permeability by 10 2 -10 4 . The state with lower permeability was selectively permeable to isobutane from a methaneisobutane mixture.
The neural correlates of visual working memory encoding: a time-resolved fMRI study.

The encoding of information into visual working memory (VWM) is not only a prerequisite step for efficient working memory, it is also considered to limit our ability to attend to, and be consciously aware of, task-relevant events. Despite its important role in visual cognition, the neural mechanisms underlying visual working memory encoding have not yet been specifically dissociated from those involved in perception and/or VWM maintenance. To isolate the brain substrates supporting VWM encoding, here we sought to identify, with time-resolved fMRI, brain regions whose temporal profile of activation tracked the time course of VWM encoding. We applied this approach to two different stimulus categories – colors and faces – that dramatically differ in their encoding time. While several cortical and subcortical regions were activated during the VWM encoding period, one of these regions in the lateral prefrontal cortex – the inferior frontal junction – showed a temporal activation profile associated with the duration of encoding and that could not be accounted for by either perceptual or general attentional effects. Moreover, this region corresponds to the prefrontal area previously implicated in ‘attentional blink’ paradigms demonstrating attentional limits to conscious perception. These results not only suggest that the inferior frontal junction is involved in VWM encoding, they also provide neural support for theories positing that VWM encoding is a rate-limiting process underlying our attentional limits to visual awareness.
Operative management of capitellar fractures: a systematic review

Purpose This study was conducted to evaluate reports of clinical outcomes of isolated capitellar fractures. Materials and methods We conducted a systematic review of medical databases reporting clinical outcomes of patients undergoing nonoperative and operative management of isolated capitellar fractures. Results We identified 28 studies for inclusion comprising 174 patients. All included studies were level IV evidence. Capitellar fractures were more common among women than men and were more likely to involve the nondominant arm. Type I fractures (84%) were more common than type II (14%) and III fractures (2%). Operative and nonoperative management both led to satisfactory clinical outcomes. No significant difference in outcomes was observed in those undergoing operative management compared with those undergoing closed reduction and immobilization. Conclusions Nonoperative and operative management of isolated capitellar fractures leads to satisfactory clinical outcomes as determined by postoperative range of motion, improvement in pain, and a return to previous levels of function. No statistical difference in outcomes was observed between those undergoing operative management compared with those treated with closed reduction and immobilization.
COUNTERPOINT: ARTIFICIAL LEGS DO NOT MAKE ARTIFICIALLY FAST RUNNING SPEEDS POSSIBLE

“Extraordinary claims require extraordinary evidence.”—Carl Sagan There is insufficient evidence to conclude that modern running specific prostheses (RSP) provide physiological or biomechanical advantages over biological legs. A grand total of n = 7 metabolic running economy values for
Teams, teams, everywhere? Job and establishment-level predictors of team use in the United States

Abstract Most research on the adoption of employee involvement (EI) has focused on the establishment level even though EI is seldom used on an establishment-wide basis. This paper offers a new perspective by using multi-level models to examine how one form of EI (teams) is used at the job level. Using data from the NOS-II, I find that patterns of team use are more consistent with the predictions of evolutionary economics and devaluation theory than with the power-process perspective or the humanistic ideals of EI rhetoric. In particular, teams with basic decision-making powers are most common in jobs that require high levels of human capital or have few non-white incumbents. More research will be needed to fully examine the connection between EI and inequality, but my analysis suggests that despite their potential for good, teams may be increasing inequality or threatening the job rewards that human capital often brings.
Effects of freezing, thawing and storage on some quality factors for portion-size beef cuts☆

Abstract Portion-size beef cuts packaged in oxygen impermeable plastic bags were used to study the effects of rates of freezing and thawing, and storage time and temperature on drip and cooking losses, shear force, destruction of glutathione and accumulation of protein-breakdown products in meat. Portions weighing 150 g or over and frozen in an air-blast at −30°C gave lower losses of drip and lower amounts of nitrogenous constituents in drip than samples weighing less than 150 g or samples frozen in cardboard boxes in still air at −18°C. Freezing and thawing or frozen storage had no significant effect on shear force of meat frozen after ageing. During frozen storage, the destruction of glutathione and accumulation of protein-breakdown products increased, depending directly on storage temperature and time. The results show that a test based on these two biochemical changes would be suitable for assessing the quality of frozen beef.
Human Dimensions in Bedside Teaching: Focus Group Discussions of Teachers and Learners

Background: Clinical teaching has moved from the bedside to conference rooms; many reasons are described for this shift. Yet, essential clinical skills, professionalism, and humanistic patient interactions are best taught at the bedside. Purpose: Clinical teaching has moved from the bedside to conference rooms; many reasons are described for this decline. This study explored perceptions of teachers and learners on the value of bedside teaching and the humanistic dimensions of bedside interactions that make it imperative to shift clinical teaching back to the bedside. Method: Focus group methodology was used to explore teacher and learner opinions. Four teacher groups consisted of (a) Chief Residents, (b) Residency Program Directors, (c) skilled bedside teachers, and (d) a convenience group of other Department of Medicine faculty at Boston University School of Medicine. Six learner groups consisted 2 each of 3rd-year students, PGY1 medicine residents, and PGY2 medicine residents. Each discussion lasted 60 ...
Preconditioning with a TLR2 specific ligand increases resistance to cerebral ischemia/reperfusion injury

The brain's resistance to ischemic injury can be transiently augmented by prior exposure to a sub-lethal stress stimulus, i.e. preconditioning. It has been reported that Toll-like receptors (TLRs) are involved in the preconditioning-induced protective effect against ischemic brain injury. In this study, we investigated the effect of preconditioning with a TLR2 specific ligand, Pam3CSK4, on focal cerebral ischemia/reperfusion (I/R) injury in mice. Pam3CSK4 was administered systemically 24 h before the mice were subjected to focal cerebral ischemia (1 h) followed by reperfusion. Cerebral infarct size was determined, blood brain barrier (BBB) permeability was evaluated, and expression of tight-junction proteins were examined after focal cerebral I/R. Results showed that pre-treatment with Pam3CSK significantly reduced brain infarct size (1.9+/-0.5% vs 9.4+/-2.2%) compared with the untreated I/R group. Pam3CSK4 pre-treatment also significantly reduced acute mortality (4.3% vs 24.2%), preserved neurological function (8.22+/-0.64 vs 3.91+/-0.57), and attenuated brain edema (84.61+/-0.08% vs 85.29+/-0.09%) after cerebral I/R. In addition, Pam3CSK4 pre-treatment preserved BBB function as evidenced by decreased leakage of serum albumin (0.528+/-0.026 vs 0.771+/-0.059) and Evans Blue (9.23+/-0.72 microg/mg vs 12.56+/-0.65 microg/mg) into brain tissue. Pam3CSK4 pre-treatment also attenuated the loss of the tight junction protein occludin in response to brain I/R injury. These results suggest that TLR2 is a new target of ischemic preconditioning in the brain and preconditioning with a TLR2 specific ligand will protect the brain from I/R injury.
Figures of the Mean: Freedom, Progress, and the Law of Statistical Averages in Kleist's “Allerneuester Erziehungsplan”

This article explores the relationship between Heinrich von Kleist's “Allerneuester Erziehungsplan” (“Very Latest Educational Plan”) and late eighteenth- and nineteenth-century statistical discourse. Both confront a common issue: the question of how a seemingly deterministic law that distributes individuals around a stable mean is compatible with the Enlightenment tenets of freedom and historical progress. The juxtaposition is mutually illuminating: Kleist's text is seen to engage critically with the discourse of statistics, and statistics helps to discover in the essay a peculiarly Kleistian figure of the mean that is key to understanding his relationship to Enlightenment optimism. Building on this result, similar figures of the mean are identified and briefly explored in two other works of Kleist, the “Glucksaufsatz” (“Essay on Happiness”) of 1799 and Das Erdbeben in Chili (The Earthquake in Chile).
Genetic and environmental models of stress-induced depression in rats

The present communication briefly reviews four rat models, two environmental and two genetic, which have engendered depressive-like behavior following exposure to stressors. Learned helplessness is a model in which a depressive-like behavioral state is induced by exposure of the rat to a series of inescapable aversive stimuli, normally foot shock. Chronic mild stress induces an anhedonic state (reduced responding for reward) by exposing the animals to a series of mild, unpredictable stressors. On the other hand, the genetic models were created by selectively breeding animals for either increased cholinergic (Flinders Sensitive Line (FSL) rats) or serotonergic (High DPAT Sensitive (HDS) rats) responses. The HDS and FSL rats are more immobile in the forced swim test than their selectively bred counterparts. Each of these models bears some resemblance to some of the key symptoms of depressed individuals and therefore has limited face validity. The depressive-like behavioral and/or anhedonic states have also been counteracted by a variety of antidepressants, indicating that the models have predictive validity. Thus, depressive-like behaviors can be produced in rats either by environmental manipulations involving stress or predisposing genetic/pharmacological factors. © 1998 John Wiley & Sons, Ltd.
A note on the McCulloch-Pitts neural net for heat-cold discrimination

An error is pointed out in the neural net model which had been previously proposed to explain the heat-cold responses that depended on the duration of the stimulus. A corrected net for the effect is given.
Management of severe postnasal haemorrhage: the Kingsley splint revisited.

Postnasal haemorrhage accompanying severe craniofacial trauma may have catastrophic consequences if not arrested promptly. The airway has usually been secured and the cervical spine stabilized, but apart from fluid replacement, other attempts to control haemorrhage in the resuscitation room of the accident and emergency department may be to no avail. We wish to draw attention to a simple device that was introduced over 100 years ago and which may rapidly aid haemostasis and prevent the onset of hypovolaemic shock.
Structural effects of DNA sequence on T·A recognition by hydroxypyrrole/pyrrole pairs in the minor groove

Synthetic polyamides composed of three types of aromatic amino acids, N-methylimidazole (Im), N-methylpyrrole (Py) and N-methyl-3-hydroxypyrrole (Hp) bind specific DNA sequences as antiparallel dimers in the minor groove. The side-by-side pairings of aromatic rings in the dimer afford a general recognition code that allows all four base-pairs to be distinguished. To examine the structural consequences of changing the DNA sequence context on T•A recognition by Hp/Py pairs in the minor groove, crystal structures of polyamide dimers (ImPyHpPy)_2 and the pyrrole counterpart (ImPyPyPy)_2 bound to the six base-pair target site 5′-AGATCT-3′ in a ten base-pair oligonucleotide have been determined to a resolution of 2.27 and 2.15 A, respectively. The structures demonstrate that the principles of Hp/Py recognition of T•A are consistent between different sequence contexts. However, a general structural explanation for the non-additive reduction in binding affinity due to introduction of the hydroxyl group is less clear. Comparison with other polyamide-DNA cocrystal structures reveals structural themes and differences that may relate to sequence preference.
Constitutive modeling of the stress–strain behavior of F-actin filament networks

Abstract The central role of the cytoskeleton in both healthy and diseased cellular functions makes it a compelling subject for detailed three-dimensional (3D) micromechanical modeling. Microstructural features of the cytoskeleton govern the cell’s mechanical behavior in many of the regulating cellular functions including cell division, adhesion, spreading, migration, contraction, and other mechanotransductive effects which influence biochemical processes. Actin microfilaments (AF) combine to form one of the predominant cytoskeletal networks important to these biological processes. Here, the AF cytoskeletal microstructure and stress-strain behavior is modeled via a microstructurally-informed continuum mechanics approach. The force-extension behavior of the individual filaments is captured using the MacKintosh derivation of the worm-like chain (WLC) constitutive relationship for short chains where a new and direct analytical expression for the filament force as a function of filament extension is developed in this paper. The filament force-extension behavior is then used in conjunction with the Arruda-Boyce eight-chain network model to capture the 3D multiaxial stress-strain behavior of the network. The resulting 3D cytoskeletal network constitutive model provides the ability to track microstructural stretch and orientation states during 3D macroscopic stretching conditions. The non-affine nature of the network model effectively accommodates the imposed macroscopic shear strain through filament rotation and a relatively small amount of filament stretch. These characteristics enable the network model, using physically realistic material properties, to capture the initial stiffness of the AF network as well as the nonlinear strain stiffening observed at large stresses. The network model predictions compare favorably with published microrheological data of in vitro AF networks.
Factors involved in ethanol narcosis: analysis in mice of three inbred strains.

Abstract We have studied the effects of genotype and dose on the time of onset of ethanol-induced sleep, as measured by fall time, and on the length of sleep. We have also investigated the relationships among genotype, dose and the blood ethanol levels at time of fall and time of awakening in three inbred mouse strains (C57BL/6J, DBA/2J and BALB/cJ). The sleep-time dose response curves are linear for the dose range tested in all three strains. There was no significant linear correlation between dose and blood ethanol level at awakening in any of the three strains. Between-strain comparisons showed significant differences in rate of ethanol clearance from the blood, and differences in tissue sensitivity to ethanol among the strains were demonstrated. Our data suggest that the major factor influencing sleep time is blood alcohol clearance, reflecting differences in alcohol metabolic rates. Between-strain comparisons of fall time showed significant differences, over the dosage range tested, in nervous system tissue sensitivity (as inferred from blood alcohol level at time of fall) between the BALB/cJ strain and the C57BL/6J and DBA/2J strains. Differences between C57BL/6J and DBA/2J strains were significant only at the lowest dose tested. The rank-ordering of the strains with respect to tissue sensitivity to ethanol is identical for all three tissue sensitivity measures obtained in these experiments.
Intensity and region-of-interest-based finite-element modeling of brain deformation

Abstract This paper proposes intensity and region-of-interest-based finite-element modeling of brain deformation. The modeling is based on the intensities of voxels within each element and motion analysis of region of interest (ROI) for image-guided minimally invasive surgery (MIS) applications. It is proposed to configure an ROI at the tip of surgical tools instead of the whole brain, so that the FEM is applied only on the ROI, and the maximum nodal displacement outside the ROI is small and in control. The deformed MR image using the proposed finite-element modeling shows better proportion to its original structures.
Reflux in children.

Gastro-oesophageal reflux (GOR) is an extremely common paediatric problem that often runs a harmless and self-limited course. Physiological GOR however can lead to marked parental anxiety, many unnecessary investigations and often unwarranted and potentially harmful therapeutic interventions. Our ability to better define GOR and gastro-oesophageal reflux disease (GORD) has improved in the past 15 years with a better understanding of the pathophysiology in infants and children due to the development and wider use of flexible endoscopy, 24-hour oesophageal pH monitoring and, more recently, the use of micromanometric methods for studying oesophageal motility. This will be further enhanced in the future with the development of non-invasive breath testing to study gastrointestinal motility and the use of electrical impedance to study fluid movement. Our therapeutic interventions have also improved particularly in the areas of acid suppression, improved surgical techniques and most recently laparoscopic fundoplication. This chapter reviews these advances in the paediatric area especially with regard to pathophysiology, diagnostic testing and therapeutic intervention.
A meta‐analytic examination of the relationship between job satisfaction and subjective well‐being

The current meta-analysis examined the relationship between job satisfaction and subjective well-being (SWB). Consistent with the spillover hypothesis, we found positive relationships between job satisfaction and life satisfaction, happiness, positive affect, and the absence of negative affect. In addition, an examination of longitudinal studies suggested that the causal relationship from SWB to job satisfaction was stronger than the causal relationship from job satisfaction to SWB.
Sister chromatid exchange as an indicator of mutagenesis

SISTER chromatid exchange (SCE), that is, the reciprocal interchange of DNA between chromatids, is easily visualised in metaphase chromosomes1,2 and has been applied to study chromosome structure3,4, chromosome damage5, and instability and DNA repair deficiency syndromes6–9. Since SCEs can be induced by subtoxic doses of carcinogens and mutagens5,10–13, their analysis offers the possibility of a rapid, sensitive and quantitative assay for genetic damage. We have begun to examine the relation between SCEs and mutations in Chinese hamster ovary (CHO) cells by quantifying the induction of SCEs in parallel with the induction of mutations producing 8-azaguanine resistance, that is, mutations predominately at the hypoxanthine phosphoribosyltransferase, hprt, locus. Since the conversion of a chemically induced DNA lesion to a SCE or mutation may depend on the nature of that lesion, we tested four chemicals that differ in their interaction with DNA—ethyl methanesulphonate (EMS; O6: N7 guanyl alkylation ratio14 of 0.03), N-ethyl-N-nitrosourea (ENU; O6: N7 guanyl alkylation ratio15 of about 0.35), the crosslinking agent mitomycin C (MMC)16 and the intercalator proflavine sulphate (PRO)17. Our results indicate a linear relation between induced SCEs and mutations. The relative efficiency, however, is different for each chemical.
Bioluminescent Bacterial Genotoxicity Test for Fatty Acid Derivatives and Heated Oils

The Mutatox test (the commercial name for a bioluminescent bacterial genotoxicity test), which has been proved to be a good alternative to the Ames test, was used in this study to test the genotoxicity of fatty acid derivatives and heated oils. This test allows either pure or complex compounds to be rapidly screened for genotoxicity. Five different column fractions isolated from autoxidized methyl linoleate or autoxidized methyl linolenate were not genotoxic with or without the activation by the S-9 (microsomal) fraction. Chlorinated fatty acids including chloroethyl caprate, laurate, palmitate, and linoleate were genotoxic in the presence of S-9 activation. When heated at 180 °C, after 32 h, soybean oil exhibited genotoxic activity with or without the S-9 activation. The addition of 1% cholesterol into the soybean oil increased the onset of the genotoxicity during heating. Keywords: Mutatox test; genotoxicity test; fatty acid hydroperoxides; chlorinated fatty acids
The Milwaukee Pollution Case - Implications for Water Resources Planning

: The Illinois v. Milwaukee Federal District Court decision is the most far reaching application yet of the federal common law of nuisance to interstate water pollution conflicts. Although a Federal Appelate Court recently rescinded part of the district court decision, Milwaukee must still upgrade its metropolitan sewage system to a level beyond that required by federal and state regulations. The improvements must be completed with or without federal aid. The case points out the apparent inability of the Clean Water Act, the most comprehensive federal legislation affecting the nation's water quality, to deal with certain interstate water quality conflicts. The Milwaukee decision could set a precedent for similar settlements elsewhere which may in turn affect the U.S. Environmental Protection Agency's water quality clean up program. A more integrated, ecosystem conscious approach to management of shared water resources (e.g., the Great Lakes) would help reduce the need for court decisions like Illinois v. Milwaukee.
A study of K+d interactions from 865 to 1585 MeV/c

Abstract We present experimental results on K + d interactions from 865 to 1585 MeV/ c incident beam momentum. We report measurements of several K + d partial cross sections and calculate most of the others using relations derived from isospin conservation and data from other experiments. The most striking feature of the cross section data is the abrupt rise of the total single-pion-production cross section near 1000 MeV/ c . We extract isospin-0 KN partial cross sections and find a rapid quasi-two-body reaction KN → K ∗ N . As in the case of the isospin-1 K + N system, it appears that the structure around 1200 MeV/ c in the total cross section for the isospin-0 K ∗ N system is well reconstructed by the sum of three smoothly varying channel cross sections σ 0 (KN), σ 0 (KN π ) and σ 0 (KN ππ ). We study thereaction KN → K ∗ N near threshold and find that the production and decay angular distributions can be interpreted in terms of t -channel phenomena, specifically a superposition of ω, ϱ, and π exchange. As is true of the isospin-1 KΔ and K ∗ N final states, the isospin-0 K ∗ N state has a behavior near threshold which is not very different from its behavior at much higher energy.
Expression of p270 (ARID1A), a component of human SWI/SNF complexes, in human tumors

Human SWI/SNF complexes use the energy of ATP hydrolysis to remodel chromosomes and alter gene expression patterns. The activity of the complexes generally promotes tissue-specific gene expression and restricts cell proliferation. The ATPase that drives the complexes, BRG1, is essential for tumor suppression in mice and deficient in a variety of established human tumor cell lines. The complex contains at least 7 other core components, one of which is a large subunit designated p270. p270 RNA is expressed in all normal human tissues examined, but protein expression is severely reduced in at least 2 human tumor lines, C33A and T47D. We show here that loss of p270 in the C33A and T47D cell lines is evident at the RNA level as well as the protein level. The implication that p270 can be informatively screened at the RNA level made a high-efficiency cancer profiling array approach to screening human tumors feasible. Expression was screened in an array containing RNA-derived cDNA from 241 tumor and corresponding matched normal tissues from individual patients. p270 deficiency was observed at a higher overall frequency than BRG1 deficiency, but all tissues were not equally affected. Deficiency of p270 was observed most frequently in carcinomas of the breast and kidney. The results were most striking in kidney, where p270 expression was deficient in 30% of carcinoma samples screened. Screening of a panel of established human renal carcinoma-derived cell lines supports the frequency observed in the primary tumor tissue samples.
Planar three-coordinate high-spin Fe(II) complexes with large orbital angular momentum: Mössbauer, electron paramagnetic resonance, and electronic structure studies.

Mossbauer spectra of [LFe(II)X](0) (L = beta-diketiminate; X = Cl(-), CH(3)(-), NHTol(-), NHtBu(-)), 1.X, were recorded between 4.2 and 200 K in applied magnetic fields up to 8.0 T. A spin Hamiltonian analysis of these data revealed a spin S = 2 system with uniaxial magnetization properties, arising from a quasi-degenerate M(S) = +/-2 doublet that is separated from the next magnetic sublevels by very large zero-field splittings (3/D/ > 150 cm(-1)). The ground levels give rise to positive magnetic hyperfine fields of unprecedented magnitudes, B(int) = +82, +78, +72, and +62 T for 1.CH(3), 1.NHTol, 1.NHtBu, and 1.Cl, respectively. Parallel-mode EPR measurements at X-band gave effective g values that are considerably larger than the spin-only value 8, namely g(eff) = 10.9 (1.Cl) and 11.4 (1.CH(3)), suggesting the presence of unquenched orbital angular momenta. A qualitative crystal field analysis of g(eff) shows that these momenta originate from spin-orbit coupling between energetically closely spaced yz and z(2) 3d-orbital states at iron and that the spin of the M(S) = +/-2 doublet is quantized along x, where x is along the Fe-X vector and z is normal to the molecular plane. A quantitative analysis of g(eff) provides the magnitude of the crystal field splitting of the lowest two orbitals, /epsilon(yz) - epsilon(2)(z)/ = 452 (1.Cl) and 135 cm(-1) (1.CH(3)). A determination of the sign of the crystal field splitting was attempted by analyzing the electric field gradient (EFG) at the (57)Fe nuclei, taking into account explicitly the influence of spin-orbit coupling on the valence term and ligand contributions. This analysis, however, led to ambiguous results for the sign of epsilon(yz) - epsilon(2)(z). The ambiguity was resolved by analyzing the splitting Delta of the M(S) = +/-2 doublet; Delta = 0.3 cm(-1) for 1.Cl and Delta = 0.03 cm(-)(1) for 1.CH(3). This approach showed that z(2) is the ground state in both complexes and that epsilon(yz) - epsilon(2)(z) approximately 3500 cm(-1) for 1.Cl and 6000 cm(-1) for 1.CH(3). The crystal field states and energies were compared with the results obtained from time-dependent density functional theory (TD-DFT). The isomer shifts and electric field gradients in 1.X exhibit a remarkably strong dependence on ligand X. The ligand contributions to the EFG, denoted W, were expressed by assigning ligand-specific parameters: W(X) to ligands X and W(N) to the diketiminate nitrogens. The additivity and transferability hypotheses underlying this model were confirmed by DFT calculations. The analysis of the EFG data for 1.X yields the ordering W(N(diketiminate)) < W(Cl) < W(N'HR), W(CH(3)) and indicates that the diketiminate nitrogens perturb the iron wave function to a considerably lesser extent than the monodentate nitrogen donors do. Finally, our study of these synthetic model complexes suggests an explanation for the unusual values for the electric hyperfine parameters of the iron sites in the Fe-Mo cofactor of nitrogenase in the M(N) state.
Decreased callosal thickness in attention-deficit/hyperactivity disorder.

Background Neuroimaging studies of attention-deficit/hyperactivity disorder (ADHD) have revealed structural abnormalities in the brains of affected individuals. One of the most replicated alterations is a significantly smaller corpus callosum (CC), for which conflicting reports exist with respect to the affected callosal segments. Methods We applied novel surface-based geometrical modeling methods to establish the presence, direction, and exact location of callosal alterations in ADHD at high spatial resolution. For this purpose, we calculated the thickness of the CC at 100 equidistant midsagittal points in an age-matched male sample of 19 individuals with ADHD and 19 typically developing control subjects. Results In close agreement with many prior observations, the CC was shown to be significantly thinner in ADHD subjects in anterior and, particularly, posterior callosal sections. Covarying for intelligence did not significantly alter the observed ADHD effects. However, group differences were no longer present in anterior sections when covarying for brain volume and after excluding ADHD subjects comorbid for oppositional defiant disorder. Conclusions Decreased callosal thickness may be associated with fewer fibers or a decrease in the myelination of fibers connecting the parietal and prefrontal cortices. This might affect interhemispheric communication channels that are necessary to sustain attention or motor control, thus contributing to symptoms of hyperactivity and impulsivity, or inattention, observed in ADHD. Future studies are necessary to determine whether callosal abnormalities reflect maturational delays or persist into adulthood.
Stereoselective synthesis of (±)-threo-γ-hydroxy-β-lysine lactone

Abstract A stereoselective synthesis of racemic threo-γ-hydroxy-β-lysine is reported. The threo aminoalcohol functionality is introduced by mercuric-ion initiated cyclofunctionalization of the acylaminomethyl ether 4a.
Increasing link marker effectiveness for WWW and other hypermedia interfaces: an examination of end-user preferences

Hypermedia information systems, especially World Wide Web (www) browsers, enhance accessibility of information through networked data management services and direct manipulation user interface features. A major characteristic of these systems is the presentation of entities that signify pathways to additional information. These objects, called link markers, distinguish and designate objects (both textual and graphical) as link endpoints within the information network. It is proposed that the design, layout, and use of link markers within an interface can enhance or impede user performance. This article presents an analysis of link marker designs based on two studies. Recommendations are that, in general, link markers that employ color and bound objects are the most effective in communicating the existence and extent of links and are most preferred by users. However, user expertise and node content are found to play a significant role. In addition, users rate link markers that follow the design prescriptions put forward here as more effective. Finally, recommendations for hypermedia designers are discussed.
Same Dance, New Partner: A Branch Music Library and Language Lab

A renovated facility provides a new home for an outsized branch music library and an underutilized language lab in a new partnership on campus. A committee is formed, compromises are made, and the project is realized in less than a year and a half. The timing of the planning and processing, the justification for maintaining a collection of printed scores, the incorporation of language materials, staffing, and shared governance are all discussed to provide a precedent and guidance for future academic mergers.
Principled sure independence screening for Cox models with ultra-high-dimensional covariates

It is rather challenging for current variable selectors to handle situations where the number of covariates under consideration is ultra-high. Consider a motivating clinical trial of the drug bortezomib for the treatment of multiple myeloma, where overall survival and expression levels of 44760 probesets were measured for each of 80 patients with the goal of identifying genes that predict survival after treatment. This dataset defies analysis even with regularized regression. Some remedies have been proposed for the linear model and for generalized linear models, but there are few solutions in the survival setting and, to our knowledge, no theoretical support. Furthermore, existing strategies often involve tuning parameters that are difficult to interpret. In this paper, we propose and theoretically justify a principled method for reducing dimensionality in the analysis of censored data by selecting only the important covariates. Our procedure involves a tuning parameter that has a simple interpretation as the desired false positive rate of this selection. We present simulation results and apply the proposed procedure to analyze the aforementioned myeloma study.
Characterization of insoluble organic matter in primitive meteorites by microRaman spectroscopy

We have analyzed the chemically and isotopically well-characterized insoluble organic matter (IOM) extracted from 51 unequilibrated chondrites (8 CR, 9 CM, 1 CI, 3 ungrouped C, 9 CO, 9 CV, 10 ordinary, 1 CB and 1 E chondrites) using confocal imaging Raman spectroscopy. The average Raman properties of the IOM, as parameterized by the peak characteristics of the so-called D and G bands, which originate from aromatic C rings, show systematic trends that are correlated with meteorite (sub-) classification and IOM chemical compositions. Processes that affect the Raman and chemical properties of the IOM, such as thermal metamorphism experienced on the parent bodies, terrestrial weathering and amorphization due to irradiation in space, have been identified. We established separate sequences of metamorphism for ordinary, CO, oxidized, and reduced CV chondrites. Several spectra from the most primitive chondrites reveal the presence of organic matter that has been amorphized. This amorphization, usually the result of sputtering processes or UV or particle irradiation, could have occurred during the formation of the organic material in interstellar or protoplanetary ices or, less likely, on the surface of the parent bodies or during the transport of the meteorites to Earth. D band widths and peak metamorphic temperatures are strongly correlated, allowing for a straightforward estimation of these temperatures.
Ventral migration of early-born neurons requires Dcc and is essential for the projections of primary afferents in the spinal cord.

Neuronal migration and lamina-specific primary afferent projections are crucial for establishing spinal cord circuits, but the underlying mechanisms are poorly understood. Here, we report that in mice lacking Dcc (deleted in colorectal cancer), some early-born neurons could not migrate ventrally in the spinal cord. Conversely, forced expression of Dcc caused ventral migration and prevented dorsolateral migration of late-born spinal neurons. In the superficial layer of the spinal cord of Dcc –/– mutants, mislocalized neurons are followed by proprioceptive afferents, while their presence repels nociceptive afferents through Sema3a. Thus, our study has shown that Dcc is a key molecule required for ventral migration of early-born neurons, and that appropriate neuronal migration is a prerequisite for, and coupled to, normal projections of primary afferents in the developing spinal cord.
Ethical Principles—Emergency Medicine

Neither law nor religion, bioethics absorbs and applies elements of both. Its theories, principles, and methods stem from various philosophical schools. Practitioners use case-based reasoning to apply bioethics to clinical situations, usually giving most weight to patients' autonomy and values, but also incorporating other relevant bioethical principles, including those encompassed in professional oaths and codes. Emergency clinicians must be able to recognize bioethical dilemmas, have action plans based on their readings and discussions, and have a method through which to apply ethical principles in clinical settings. This article provides an overview of ethical considerations and guidelines for emergency clinicians.
Changes in excitatory amino acid modulation of phosphoinositide metabolism during development

Abstract Two different developmental patterns of stimulation of phosphoinositide (PI) metabolism by excitatory amino acid (EAA) receptors were observed during the postnatal maturation of various brain regions. A ‘burst’ in PI metabolism was seen at postnatal day 6 (PND6) in olfactory bulb and cerebellum and at PND9 in hippocampus. In cortex and thalamus/hypothalamus high levels of PI metabolism were observed initially, and then began to decline at PND15 and PND18, respectively. NMDA inhibition of PI metabolism was generally found to parallel the EAA activation but the persistence of inhibition varied in the different brain regions.
XMM-NEWTON OBSERVATION OF THE α PERSEI CLUSTER

We report on the analysis of an archival observation of part of the ? Persei cluster obtained with XMM-Newton. We detected 102 X-ray sources in the band 0.3-8.0?keV, of which 39 of them are associated with the cluster as evidenced by appropriate magnitudes and colors from Two Micron All Sky Survey photometry. We extend the X-ray luminosity distribution (XLD) for M dwarfs, to add to the XLD found for hotter dwarfs from spatially extensive surveys of the whole cluster by ROSAT. Some of the hotter stars are identified as a background, possible slightly older group of stars at a distance of approximately 500?pc.
Structural and Magnetic Effects of meso-Substitution in Alkyl-Substituted Metalloporphyrinate π-Cation Radicals: Characterization of [Fe-(TalkylP.)(Cl)]SbCl6 (alkyl = ethyl and n-propyl)

We report the preparation and characterization of two meso-alkyl substituted porphyrin pi-cation radical derivatives, [Fe(TalkylP(*))(Cl)]SbCl(6) (alkyl = ethyl or propyl). Both complexes have been characterized by UV/vis/near-IR, IR, and Mossbauer spectroscopy, temperature-dependent solid-state magnetic susceptibility measurements, and X-ray structure determinations. All data for both oxidized species are consistent with the formulation of the complexes as ring-oxidized iron(III) porphyrin species. The molecular structures of the two five-coordinate species have the typical square-pyramidal coordination group of high-spin iron(III) derivatives. The crystal structures also reveal that the species form cofacial pi-pi dimers with lateral shifts of 1.44 A and 3.22 A, respectively, for the propyl and ethyl radical derivatives. Both radicals exhibit porphyrin cores with alternating bond distance patterns in the inner 16-membered ring. In addition, [Fe(TEtP(*))(Cl)]SbCl(6) and [Fe(TPrP(*))(Cl)]SbCl(6) have been characterized by temperature-dependent (6-300 K) magnetic susceptibility studies, the best fitting of the temperature-dependent moments reveal strong coupling between iron spins and porphyrin radical, and a smaller magnitude of antiferromagnetic coupling between ring radicals, which are opposite to those found in the five-coordinate iron(III) OEP radicals. The differences in structure and properties of the cation radical meso-alkyl and beta-alkyl derivatives possibly reflect differences in properties of a(1u)- and a(2u)-forming radicals.
An asymptotic model of a nonlinear adaptive elastic plate

In this paper, an asymptotic method is used to obtain a model of a nonlinear adaptive elastic plate. The plate is one of the two geometric solids that can be used in unison to model the trabeculae of bone. The other is the rod. Modeling of the rod has received much attention [I. Figueiredo, L. Trabucho, Asymptotic model of a nonlinear adaptive elastic rod, Mathematics and Mechanics of Solids 9 (4) (2004); L. Trabucho, J.M. Viano, Mathematical Modeling of Rods, in: P.G. Ciarlet, J.L. Lions (Eds.), Handbook of Numerical Analysis, vol. IV, North-Holland, Amsterdam, 1996], but not the plate. The model for the plate mirrors what has been done for the rod. Asymptotic expansions are formulated for the displacement field and a rate equation governing the deposition and reabsorption of bone tissue. It is shown that both the asymptotic expansions can be simplified and certain relationships can be derived from the force balance equation. Characterization of the first few terms of both asymptotic expansions is also presented.
Response to letter: identification of patients at risk of anaphylactoid reactions to N-acetylcysteine in the treatment of paracetamol overdose

To the Editor:We read with great interest the work by Schmidt that further delineated patients who are at high risk of developing anaphylactoid reactions to N-acetylcysteine (NAC). The results and ...
Laser Machining of Silicon Nitride Base Materials

Abstract This paper describes the depth controlled machining of TiN/Si3N4 and SiC/ Si3N4 ceramic materials using a Nd:YAG laser. Material removal rates, surface finishes and microcracking tendencies are examined. Material removal rates as high as 0.11 cc/min were obtained on TiN/Si3N4. Pulse length was found to have a strong influence on the micro-cracking. Microcracks were reduced when pulse length was shortened, while keeping all other parameters constant. Pulse energy influences surface roughness, smoother surfaces were produced with lower energies. When processing in the 0.8 and 1.0 J/pulse range an average surface roughness of 0.81 μm was obtained. Plasma formation does not affect the material removal rates when overlapping pulses up to 75% at frequencies below 200 Hz are used.
Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of trioctylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 μg l−1 of tin in the MIBK solution or 0.2–0.3 μg g−1 in the rock. The concentration range is linear between 2.5 and 500 μg l−1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 μg l−1 level and < 7% at the 10–30 μg l−1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 μg g−1 or less.