cssi/SciSciGPT-SciSciNet huggingface dataset:
Generation of 40-ps, terawatt 10-/spl mu/m pulses using self-phase modulation in plasma

Summary form only given. Picosecond/femtosecond pulses can now be amplified to multiterawatt powers at selected wavelengths in the visible and the near-IR spectral regions using the chirped-pulse amplification (CPA) technique. However, amplification of a picosecond pulse with a CO/sub 2/ laser - the only feasible candidate for generation of high-power mid-IR pulses - is difficult because of the relatively narrow bandwidth of the CO/sub 2/ gas and the lack of an adequate CPA technique. The many potential applications, including X-ray generation and laser acceleration of particles, provide a strong motivation for developing a TW CO/sub 2/ laser. We report on amplification of self-chirped 10-/spl mu/m pulses up to a TW level of power, for which a novel pulse shortening technique is used. It is based on the self-phase modulation in a plasma followed by rejection of the chirped part of the pulse in the active medium. We have shown experimentally that, for very-high-power-density pulses, power broadening is a powerful tool to compensate for the lack of bandwidth. Pulses of duration /spl sim/40 ps, much shorter than the pressure broadened bandwidth limit, have been obtained in a CO/sub 2/ amplifier.
Finding a Civic Voice: Latino Immigrant Youths’ Experiences in High School Social Studies

Socialization into the dominant civic and political discourse lies at the heart of social studies. As they become proficient in the discourse of home and school, Latino immigrant youth demonstrate the potential to uniquely benefit from this socialization. This qualitative study explores ten Latino immigrant young adults’ perceptions of how their social studies experiences shaped their young adult civic selves. Participants internalized not only their parents’ high expectations for them, but also those of their teachers, highlighting the potentially instrumental role of schools in the civic fabric of the nation. In addition, the Latino young adults felt empowered by their social studies teachers via civic expectations and academic encouragement and perceived this empowerment to have facilitated the skill development necessary for later civic leadership. In closing, we reflect on immigrant students’ incorporation of the discourse of the dominant culture with that of the home to develop their own civic voices.
P1A-9 Correlation Analysis of the Beam Angle Dependence for Elastography

Signal decorrelation is a major source of error in the displacements estimated using correlation techniques for elastographic imaging. Previous papers have addressed the variation in the correlation coefficient as a function of the applied compression for a finite window size and an insonification angle of zero degrees. The recent use of angular beam-steered radiofrequency echo signals for spatial angular compounding and shear strain estimation have demonstrated the need for understanding signal decorrelation artifacts for data acquired at different beam angles. In this paper, we provide both numerical and closed form theoretical solution of the correlation between pre- and post-compression radiofrequency echo signals acquired at a specified beam angle. Accuracy of the theoretical results is verified using tissue-mimicking phantom experiments on a uniformly elastic phantom using beam-steered data acquisitions on a linear array transducer. The theory predicts a faster decorrelation with changes in the beam or insonification angle for longer radiofrequency echo signal segments and at deeper locations in the medium. Theoretical results provide useful information for improving angular compounding and shear strain estimation techniques for elastography
Internalization of Ia molecules into Birbeck granule-like structures in murine dendritic cells

Dendritic cells isolated from the draining lymph nodes of mice sensitized epicutaneously with hapten are potent anti gen-presenting cells and contain Birbeck granules and cored tubules characteristic of antigen-activated epidermal Langerhans cells. We used immunogold labeling and transmission electron microscopy to follow the internalization of Ia molecules in these antigen-presenting cells. we found that Ia molecules were internalized into Birbeck granule-like structures in the antigen-activated dendritic cells. Computer reconstruction of serial sections of the dendritic cells demonstrated that these structures span the cytoplasm from the cell membrane to the nuclear membrane and are associated with lysosomes. The internalization of Ia molecules into these structures supports the hypothesis that the Birbeck granule-like structures are derived from the cell membrane and are involved in the antigen-processing/presenting function of the dendritic cells.
On the least asymmetric wavelets

The asymmetry of Daubechies' (1988, 1992) scaling functions and wavelets can be diminished by minimizing a special second moment in time for the wavelet-generating discrete-time filter. The moment is involved in an uncertainty relation for discrete-time signals. Other measures of asymmetry are addressed as well, and corresponding results are compared.
Signal Transduction by DR3, a Death Domain-Containing Receptor Related to TNFR-1 and CD95

Tumor necrosis factor receptor-1 (TNFR-1) and CD95 (also called Fas or APO-1) are cytokine receptors that engage the apoptosis pathway through a region of intracellular homology, designated the “death domain.” Another death domain-containing member of the TNFR family, death receptor 3 (DR3), was identified and was shown to induce both apoptosis and activation of nuclear factor κB. Expression of DR3 appears to be restricted to tissues enriched in lymphocytes. DR3 signal transduction is mediated by a complex of intracellular signaling molecules including TRADD, TRAF2, FADD, and FLICE. Thus, DR3 likely plays a role in regulating lymphocyte homeostasis.
Temporal stability of visual search-driven biometrics

Previously, we have shown the potential of using an individual’s visual search pattern as a possible biometric. That study focused on viewing images displaying dot-patterns with different spatial relationships to determine which pattern can be more effective in establishing the identity of an individual. In this follow-up study we investigated the temporal stability of this biometric. We performed an experiment with 16 individuals asked to search for a predetermined feature of a random-dot pattern as we tracked their eye movements. Each participant completed four testing sessions consisting of two dot patterns repeated twice. One dot pattern displayed concentric circles shifted to the left or right side of the screen overlaid with visual noise, and participants were asked which side the circles were centered on. The second dot-pattern displayed a number of circles (between 0 and 4) scattered on the screen overlaid with visual noise, and participants were asked how many circles they could identify. Each session contained 5 untracked tutorial questions and 50 tracked test questions (200 total tracked questions per participant). To create each participant’s "fingerprint", we constructed a Hidden Markov Model (HMM) from the gaze data representing the underlying visual search and cognitive process. The accuracy of the derived HMM models was evaluated using cross-validation for various time-dependent train-test conditions. Subject identification accuracy ranged from 17.6% to 41.8% for all conditions, which is significantly higher than random guessing (1/16 = 6.25%). The results suggest that visual search pattern is a promising, temporally stable personalized fingerprint of perceptual organization.
Responses of inferior colliculus neurons in C57BL/6J mice with and without sensorineural hearing loss: effects of changing the azimuthal location of an unmasked pure-tone stimulus.

Abstract Azimuth functions (discharge rates evoked by tone bursts as a function of stimulus azimuth) were obtained from neurons in the inferior colliculus (IC) of C57 mice aged 2, 7 and 12 months. Because of a gene that affects the cochlea, C57 mice exhibit high-frequency sensorineural hearing loss at 7 and 12 months. Azimuth functions were examined for differences that might be related to the decline in localization acuity that accompanies hearing loss in this strain. Irrespective of age group, nearly all neurons in the central area of the IC were sensitive to the azimuth of a best frequency (BF) stimulus, as revealed by azimuth functions in which firing rates varied by more than 50% from maximum to minimum at one or more intensities. The age groups were similar in many respects (e.g., there were no significant differences in the proportion of functions meeting the criterion for direction sensitivity, the proportion of neurons with direction sensitive functions over a range of intensities, azimuth function shapes, the locations or stability of ‘borders’ separating angles evoking high versus low discharge rates). However, in 7- and 12-month-olds: the proportion of IC neurons in which the strongest excitatory driving was evoked by ipsilateral stimulation was significantly larger; azimuth function borders were more likely to be ‘reversed’ (i.e., the high rates being evoked by the more ipsilateral angle); and a greater proportion of azimuth functions met the criterion for direction sensitivity only minimally. The findings suggest that binaural excitatory-inhibitory interactions are altered in IC neurons of hearing-impaired mice.
1H and 31P spectroscopy and bioenergetics in the lateralization of seizures in temporal lobe epilepsy

Over the past decade, (1)H and (31)P spectroscopy measurements have demonstrated that significant metabolic alterations occur in temporal lobe epilepsy. However, to most accurately interpret these changes, metabolic heterogeneity and differences between gray and white matter must be accounted for. These alterations, decreased NAA and the ratio of phosphocreatine/inorganic phosphate, can be reversed with successful treatment of seizures. The reversibility of these two measures is consistent with the localization of NAA synthesis to neuronal mitochondria and the important role for bioenergetics in the pathophysiology of temporal lobe epilepsy.
The Real Story Behind the Nation's First Shield Law: Maryland, 1894–1897

Blame it on H.L. Mencken. His unsupported account of how Maryland adopted the nation's first shield law in 1896 has been repeated in books and articles for seventy-five years, but it was a fabrication based on shoddy reporting. This article will show the law was not prompted, as Mencken claimed, by the jailing of Baltimore Sun reporter John T. Morris but by the criminal indictments of reporters John S. Shriver and Elisha J. Edwards in 1894. Passage of the law was not connected to local events but was sparked by a scandal unfolding in Washington. The drive for a shield law was not isolated to Maryland but was part of a national lobbying campaign that included talk of a federal shield law. Finally, that campaign did not emanate from The Baltimore Sun but from The Baltimore American.
1240 LARGE INTRAVENTRICULAR HEMORRHAGE (IVH) AND LABOR IN INFANTS ≥11000g

Seventy-five infants ≤34 weeks gestation & birthweight ≥1000g had ultrasound brain studies to diagnose IVH and subependymal hemorrhages (SEH) on the first day of life (30′ to 23 hrs. after birth). They were grouped according to delivery (with & without labor). Diagnosis in the first 24 hours after birth & major IVH/SEH (IVH/SEH associated with ventricular enlargement) were considered. Infants born after labor had a higher incidence of major IVH/SEH even if those without RDS, PDA and asphyxia born with labor were compared with sick infants born without labor (2 Rh-hydrops, 14 RDS & PDA, 2 severe asphyxia). Labor seems important in the pathogenesis of large IVH/SEH in infants BW≥1000g.
A review of research in low earth orbit propellant collection

This comprehensive review examines the efforts of previous researchers to develop concepts for propellant-collecting spacecraft, estimate the performance of these systems, and understand the physics involved. Rocket propulsion requires the spacecraft to expend two fundamental quantities: energy and propellant mass. A growing number of spacecraft collect the energy they need to execute propulsive maneuvers in-situ with solar panels. In contrast, every spacecraft using rocket propulsion has carried all of the propellant mass needed for the mission from the ground, which limits the range and mission capabilities. Numerous researchers have explored the concept of collecting propellant mass while in space. These concepts have varied in scale and complexity from chemical ramjets to fusion-driven interstellar vessels. Research into propellant-collecting concepts occurred in distinct eras. During the Cold War, concepts tended to be large, complex, and nuclear powered. After the Cold War, concepts transitioned to solar power sources and more effort has been devoted to detailed analysis of specific components of the propellant-collecting architecture. By detailing the major contributions and limitations of previous work, this review concisely presents the state-of-the-art and outlines five areas for continued research. These areas include air-compatible cathode technology, techniques to improve propellant utilization on atmospheric species, in-space compressor and liquefaction technology, improved hypersonic and hyperthermal free molecular flow inlet designs, and improved understanding of how design parameters affect system performance.
Amphibian yolk platelet ultrastructure visualized by freeze-etching.

Amphibian yolk platelets are composed of lipoprotein subunits arranged in an ordered crystalline structure. Freeze-etch electron microscopy of isolated Xenopus platelets provides a direct view of the structure of the crystal and aids the interpretation of fracture phenomena in lipoprotein systems. A study has been made both of fracture faces and of faces produced by fracturing and etching following partial dissolution of platelets in electrolyte solutions. In freeze-etch replicas, main body crystals appear to be composed of dimers. Rectangular and semihexagonal patterns are seen in fracture faces. Rectangular patterns are seen also in faces produced by partial dissolution and revealed by fracturing and etching. Dissolution faces with possible semihexagonal patterns are distinct but infrequent. Based on this evidence, a new closest-packing model of platelet structure is proposed using lipovitellin dimers as building blocks, with one molecule of the second major protein component, phosvitin, associated with each monomer of the lipovitellin dimer.
Application of the EM Method A Study of Maximum Likelihood Estimation of Multiple Indicator and Factor Analysis Models

The EM (Estimation-Maximization) algorithm is exploited to provide maximum likelihood estimates of the parameters of multiple indicator/factor analysis models. This method reduces considerably the storage and computational burden of such estimation. A computer program in BASIC language that performs the computations is listed in an appendix. The specification of correlated errors is also provided for in this application of the method.
Stress-Induced Leakage from Phospholipid Vesicles: Effect of Membrane Composition

When subjected to large hypoosmotic gradients, lipid vesicles swell and rupture, expelling contents in an attempt to reach mechanical equilibrium. To date, the influence of the lipid composition on this leakage process has not been studied. In this paper, we present osmotic leakage data for vesicles made of a series of phosphatidylcholine lipids and show that the lipid composition is an important control parameter in osmotically forced leakage. We also show that current models for the leakage phenomenon fail to predict experimental results and offer an improved model that allows for the possibility of a mixed population of unilamellar and multilamellar vesicles. Finally, we demonstrate that mechanical properties found using the micropipet aspiration method might not be applicable to osmotic swelling experiments utilizing nanometer-scale vesicles.
A method for determining interaural attenuation in animal models of asymmetric hearing loss

Asymmetric or unilateral sensorineural hearing loss is an important hall-mark of various forms of sensorineural hearing loss. Animal research regarding the etiology and mechanism of these disorders often requires hearing estimates in each ear of experimental animals. Monaural auditory testing of animals with experimentally induced unilateral hearing loss therefore requires prior knowledge of interaural attenuation (IAA) to facilitate contralateral masking. The purpose of this study is to describe a method of determining frequency-specific IAA data and to present relevant information obtained in the rats--a frequently used animal in studies of acquired sensorineural hearing loss. A custom-made sound source was designed to accomplish threshold determination at important frequencies in the dynamic range of rats. Six male Long-Evans rats were surgically monauralized by ablation/obliteration of the cochlea. Auditory brainstem response (ABR) thresholds were determined for ipsilateral and contralateral presentations of 2-kHz, 10-kHz, and 40-kHz toneburst. IAA was calculated by subtracting the frequency-specific ABR threshold obtained from the normal ear from that obtained following tone presentation to the 'dead' ear, and was found to average 65.0 +/- 10.5 dB at 2 kHz, 45.0 +/- 8.4 dB at 10 kHz, and 47 +/- 15.1 dB at 40 kHz (+/- standard deviation). Using data obtained from the animal demonstrating the smallest IAA, masking is not needed until a threshold asymmetry of 50 dB at 2 kHz and 30 dB at 10 and 40 kHz is observed. In order to obtain bilateral auditory threshold information in any animal model of asymmetric hearing loss, data regarding IAA are needed in order to know when to apply contralateral masking and therefore avoid crossover stimulation of the non-test ear. The protocol presented herein provides guidelines for use in any animal model of sensorineural hearing loss which may demonstrate unilateral or asymmetric deficits.
A comparison of the staircase voltammetric and polarographic responses of pyrazine and several substituted pyrazines in aqueous acid

Abstract Staircase voltammetry, pulse polarography and dc polarography were employed to examine the reduction of a series of substituted pyrazines in aqueous acid. In each case, an overall two-electron, three-proton reduction to the corresponding 1,4-dihydropyrazinium ion was indicated. With pyrazine itself, and with a single electron-withdrawing substituent in the ring, the reduction product is relatively stable and reversible electrochemical responses are observed. Electron-releasing substituents decrease the product stability, causing the reduction to become less reversible. In the latter cases, a catalytic proton reduction wave appears at more negative potentials. The half-wave potentials for the monosubstituted pyrazines examined exhibit a reasonable correlation with the Hammett equation except for 2-chloropyrazine which, surprisingly, deviates substantially from the correlation line.
Comparison of Complete and Incomplete Revascularization by Coronary Angioplasty for Unstable Angina

When a “culprit lesion” can be identified in a patient with unstable angina, it may be possible to achieve clinical improvement with incomplete revascularization. We analyzed actuarial survival free of an event (severe angina, myocardial infarction, coronary artery bypass graft, or death) at 6, 12, 18, and 24 months in 83 patients with multi-vessel disease and unstable angina who had undergone successful percutaneous transluminal coronary angioplasty (PTCA); revascularization was complete in 31 patients and incomplete in 52. Event-free survival in 85 patients with single-vessel disease and unstable angina who had undergone successful PTCA also was analyzed. Event-free survival at 24 months was worse in the multivessel disease patients than in the single-vessel disease patients (62% vs 85%; P = 0.001). Multivessel disease patients with complete revascularization had the same event-free survival as those with incomplete revascularization (63% vs 61%; P NS). Diagnostic angiograms revealed thrombus or an irregular ulcerated lesion in 42 of the multivessel disease patients. The event-free survival of these 42 patients was not different from that of the multivessel disease patients as a whole (64% vs 60%; P NS). We conclude that in patients with multivessel disease and unstable angina the event-free survival after PTCA is poorer than in patients with single-vessel disease and unstable angina. In the former patients, event-free survival does not necessarily depend on the completeness of revascularization. The outcome of patients who have intra-coronary thrombus or an irregular ulcerated lesion resembles the outcome of patients who lack these findings. (J Interven Cardiol: 1988:1:1)
Freeing The Teacher: A Supervisory Process

ABSTRACT Directive and clinical approaches to teacher supervision, while appreciated by some teachers, are also problematic. The most obvious problem is that teachers are not provided with much opportunity to develop their decision-making skills about what and how to teach. The focus of this paper is to present and illustrate a process through which the supervisor can provide teachers with opportunities to make their own teaching decisions by leading them through a process of exploration. This process includes teaching teachers how to observe classroom interaction, code and analyze interaction, interpret patterns of classroom behavior, and make informed decisions about teaching based on the analysis and interpretation. In addition, in order to enhance exploration, the supervisor is encouraged to bring teachers together to work on activities which center on teaching.
Continuous oral contraception: Changing times.

Oral contraceptives (OCs) remain the most common method of reversible contraception. Despite lowering of oestrogen and progestin content, the same basic design of 21 combination oestrogen plus progestin pills followed by a week of placebo pills has remained. Numerous studies have now documented that the 21/7 regimen needs to be modified. The 7-day hormone-free interval (HFI) in today's low-dose OCs is associated with reduced pituitary-ovarian suppression, allowing for ovarian follicular development, endogenous oestradiol production and possible ovarian cyst formation and ovulation. The 7-day HFI is also associated with hormone withdrawal symptoms that can lead to discontinuation and unintended pregnancy. Modifications in OC regimens are now appearing on the market secondary to the accumulated scientific data on the disadvantages of low-dose 21/7 pills. This article will review the data on problems with standard OC regimens and modifications that can improve the efficacy and side-effect profile.
First-Principle Studies of Permanent-Magnet Materials

First-principle electronic structure studies complement experimental research on hard-magnet materials. Since the discovery of Nd 2Fel4B in 1984, the research in this area has been concentrated on T(Fe,Co)-rich rare-earth compounds such as RT12 and R2T17 and exchange coupled hard/soft phases. Self-consistent spin-polarized electronic structure calculations are carried out for the sequence YFc2→ YFe3→Y2Fe17→YFe12 to study the variation of the magnetization and Curie temperature as a function of the Fe concentration. Calculations are performed for R2T17 systems which show significant improvements in their Curie temperatures with interstitial and substitutional modifications. The calculated results are compared with the available experimental data. Computer simulations are carried out for FePt/Fe and SmCo5/Co1−x -Fex, hard/soft multilayers.
Targeting putative mu opioid/metabotropic glutamate receptor-5 heteromers produces potent antinociception in a chronic murine bone cancer model

The therapeutic management of chronic pain associated with many cancers is problematic due to the development of tolerance and other adverse effects during the disease progression. Recently we reported on a bivalent ligand (MMG22) containing both mu agonist and mGluR5 antagonist pharmacophores that produced potent antinociception in mice with LPS-induced acute inflammatory pain via a putative MOR-mGluR5 heteromer. In the present study we have investigated the antinociception of MMG22 in a mouse model of bone cancer pain to determine its effectiveness in reducing this type of chronic nociception. There was a 572-fold increase in the potency of MMG22 over a period of 3-21 days that correlated with the progressive increase in hyperalgesia induced by bone tumor growth following implantation of fibrosarcoma cells in mice. The enhancement of antinociception with the progression of the cancer is possibly due to inhibition of NMDA receptor-mediated hyperalgesia via antagonism of mGluR5 and concomitant activation of MOR by the MMG22-occupied heteromer. Notably, MMG22 was 3.6-million-fold more potent than morphine at PID 21. Since MMG22 exhibited a 250,000-times greater potency than that of a mixture of the mu opioid (M19) agonist and mGluR5 antagonist (MG20) monovalent ligands, the data suggest that targeting the putative MOR-mGluR5 heteromer is far superior to univalent interaction with receptors in reducing tumor-induced nociception. In view of the high potency, long duration (>24h) of action and minimal side effects, MMG22 has the potential to be a superior pharmacological agent than morphine and other opiates in the treatment of chronic cancer pain and to serve as a novel pharmacologic tool.
In vivo arteriolar dilation in response to parathyroid hormone fragments.

Abstract The in vivo responsiveness of small arterioles to the topical administration of two parathyroid hormone fragments was investigated using television microscopy. Male Sprague-Dawley rats were anesthetized with sodium pentobarbital (50 mg/kg) and second- and third-order arterioles in the cremaster muscle were exposed to increasing concentrations (2×10 −5 to 6×10 −4 mg/ml) of either hPTH (1–34) or bPTH-(3–34). Second- and third-order arterioles within the cremaster dilated (183% and 281% of control, respectively) following exposure to PTH-(1–34) in bath concentration of 10 −4 mg/ml and above. The dilation associated with PTH administration was abolished in second-order and greatly attenuated for third-order arterioles when the first two amino acid residues of the PTH molecule were removed (PTH (3–34) fragment). Inhibition of endogenous prostaglandins synthesis with mefenamic acid did not attenuate the vasodilator response to PTH. However, exposure to the muscarinic blocking agent atropine (10 −7 g/ml) totally inhibited the dilator response to PTH-(1–34). These data suggest that PTH induces arteriolar dilation by stimulation of muscarinic receptors in the vasculature possibly by causing the release of endogenous acetylcholine.
Current-driven vortex dynamics in untwinned superconducting single crystals

Current-driven vortex dynamics of type-II superconductors in the weak-pinning limit is investigated by quantitatively studying the current-dependent vortex dissipation of an untwinned YBa2Cu3O7 single crystal. For applied current densities (J) substantially larger than the critical current density (Jc), non-linear resistive peaks appear below the thermodynamic first-order vortex-lattice melting transition temperature (Tm), in contrast to the resistive hysteresis in the low-current limit (J < Jc). These resistive peaks are quantitatively analysed in terms of the current-driven coherent and plastic motion of vortex bundles in the vortex-solid phase, and the non-linear current - voltage characteristics are found to be consistent with the collective flux-creep model. The effects of high-density random point defects on the vortex dynamics are also investigated via proton irradiation of the same single crystal. Neither resistive hysteresis at low currents nor peak effects at high currents are found after the irradiation. Furthermore, the current-voltage characteristics within the instrumental resolution become completely ohmic over a wide range of currents and temperatures, despite theoretical predictions of much larger Jc-values for the given experimental variables. This finding suggests that the vortex-glass phase, a theoretically proposed low-temperature vortex state which is stabilized by point disorder and has a vanishing resistivity, may become unstable under applied currents significantly smaller than the theoretically predicted Jc. More investigation appears necessary in order to resolve this puzzling issue.
Calcium Carbonate: Factors Affecting Saturation in Ocean Waters off Bermuda

Bermuda marine waters are not in equilibrium with the bulk carbonate sediments with which they are in contact, and they are supersaturated with respect to pure calcite. This apparent supersaturation seems to result from a metastable equilibrium between sea water and the most soluble solid phase available locally in excess.
Perception of drinking water temperature and effects for humans after exercise

Abstract Subjects rated the perceived temperature and hedonic values of four samples of drinking water (5°, 16°, 22°, 38°C) after exercise and on a control day. Ad lib drinking of any of the four samples was permitted for 20 minutes after exercise and intake was measured. Subjects completed questionnaires pertaining to their subjective states. Sensory thermal neutral water was found to be close to 22°C which was also judged to be affectively neutral. Subjects rated 16°C water higher on the hedonic scale after exercise than they did on a control day, despite the fact that no change in the perception of this temperature was observed. Responses to the symptoms questionnaire showed a marked effect of exercise on the perception of thirst, sweating, body warmth and dryness in the mouth. Sensations of stomach fullness could not account for the incomplete rehydration of most subjects in the time allotted. It was suggested that a rapid reduction in symptoms which initiate drinking was responsible for drinking termination. The role of water temperature in the reduction of thirst symptoms was discussed.
Large bore high field magnets

Abstract The National High Magnetic Field Laboratory (NHMFL) is, as part of its charter with the National Science Foundation (NSF), building several state-of-the-art magnets which exploit the technological limits in field strength and useful volume. Four magnets are of special interest in this context: a 20 T, 200 mm bore resistive magnet, a persistent 21.1 T, 144 mm bore superconducting NMR magnet, a 15 T, 620 mm bore powered superconducting magnet, and a 50 T, 200 mm bore pulse magnet, built in cooperation with LANL. A condensed overview of the NHMFL and a description of its activities in magnet research is given. The path to a magnet optimized for the detection of axions is explored. To this end, the large bore magnets in use or construction at the NHMFL and their different technologies are compared. Design issues of superconducting magnets for reliable operation, an optimization example and a demonstration of the cost constraints follow.
Metabolic utilization and renal handling of d-lactate in men

Abstract This study was carried out to investigate the renal handing of d- and l-lactate and the extent of their metabolism in men. Ten healthy male subjects were given an intravenous (IV) infusion of a racemic mixture of d- and l-lactate. At an infusion rate of 1.0 to 1.3 meq/kg body weight of each isomer, d-lactate achieved a concentration in plasma of 1.7 to 3.0 meq/L, and l-lactate 2.8 to 4.2 meq/L. At these levels, fractional excretion of d-lactate ranged from 40% to 65%, while fractional excretion of l-lactate was always less than 5%. At a higher infusion rate, 1.8 to 2.0 meq/kg/h, plasma concentrations of d- and l-lactate reached 4.5 to 6.0 meq/L, and 4.0 to 6.7 meq/L, respectively. Fractional excretion of d-lactate then ranged from 61% to 100%, while that of l-lactate ranged from 9% to 30%. At plasma concentrations of d-lactate less than 3.0 meq/L, reabsorption of l-lactate was nearly complete, but when plasma d-lactate exceeded 3.0 meq/L, reabsorption of l-lactate was considerably impaired. Similarly, for a given concentration of plasma d-lactate, its reabsorption was more efficient when the plasma l-lactate concentration and fractional excretion of l-lactate were low than when they were high. At an infusion rate of d-lactate of 1.0 to 1.3 meq/L, about 90% of the infused lactate was metabolized, and at a higher infusion rate, still more than 75% of the infused lactate was metabolized. The findings indicate that both 1- and d-lactate mutually interfere with their renal tubular reabsorption, and that reabsorption of l-lactate is much more efficient than that of d-lactate. Despite widespread belief to the contrary, the metabolic utilization of d-lactate is quite efficient in normal men.
THE EFFECT OF THE WAVE PROPAGATION SCHEME ON NEARSHORE WAVE PREDICTIONS

WAM (acronym for WAve Model) is a third-generation wave model used to compute the spectra of random short-crested wind-generated waves on Eulerian grids and is one of the most extensively tested and widely used wave models in the world. Waves can be propagated on a spherical or a Cartesian grid. For large ocean regions, waves must be propagated on a sphere to account for the curvature of the Earth. For coastal and nearshore regions, smaller nests with higher mesh resolution are used. As the size of the nests becomes smaller, the differences between a spherical grid and a Cartesian grid for the same nest become smaller and one would assume that the differences in the computed results would also be small. However, one should not assume that this behavior is automatically recovered in numerical wave models owing to the different nature of spherical and Cartesian grids — the wave transport equation when written in spherical coordinates is not divergence-free whereas it is divergence-free when written in Cartesian coordinates! Therefore, the transition of spherical methods to divergence-free needs to be numerically verified. The purpose of this numerical study was to examine results obtained with the spherical and Cartesian wave propagation options in the WAM code for a nearshore zone where depth effects are important. This study found that Cartesian wave propagation in the WAM code produced more accurate nearshore wave predictions than spherical wave propagation!
The Color of Their Skin or the Content of Their Behavior: Race and Perceptions of African American Legislators

Previous studies have shown that, because of their race, African American candidates for public office are often evaluated less favorably than their colleagues by voters. Does this dynamic continue when black candidates become elected officials? Using data on the North Carolina General Assembly, I address this question by examining the effects of race on perceptions of legislative effectiveness. When the dependent variable is the average effectiveness rating given by three groupslobbyists, journalists, and other legislators-there is evidence that African American representatives are evaluated negatively because of their race. When the dependent variable is disaggregated into the separate effectiveness ratings given by each of the respondent groups individually, these negative perceptions of blacks on account of race remain on the part of lobbyists and other legislators, but not for journalists. Moreover, the negative perceptions of black representatives are not mitigated by these representatives possessing certain characteristics (e.g., seniority and leadership positions) that previous studies have found to be correlated with positive effectiveness evaluations. The presence of an African American Speaker in one legislative session did, however, seem to attenuate the negative perceptions.
Procedures Performed by the Hospitalist and Non-hospitalist

To the Editors:— Thakkar et al. present results from a cross-sectional survey comparing the number of bedside procedures performed by hospitalist and non-hospitalist physicians.1 This article is a reanalysis of 2004 survey data. The authors studied the performance of nine procedures designated “core competencies” by the Society of Hospital Medicine (SHM) in 2006. Although only 11% of the 175 hospitalists surveyed in 2004 performed all nine procedures, 39% to 50% had performed lumbar puncture, abdominal paracentesis, thoracentesis, and central venous catheter (CVC) insertion in the prior year.1 To our knowledge, classifying a set of procedures as core competencies does not require that an individual hospitalist perform them all in a specific time period. Therefore, we disagree with the authors’ conclusion that “there is a relatively low frequency with which physicians classified as hospitalists engage in the core competency procedures of hospital medicine.”1 In our view, the data show that hospitalists perform bedside procedures regularly in American hospitals. It is misleading to generalize practice patterns of current hospitalists from these results. First, this report presents information from only 175 physicians at a time when there were over 12,000 hospitalists in the United States.2 In 2010, the number of hospitalists will approach 30,000.2 Second, the survey was designed to sample general internist members of the American College of Physicians,1 not hospitalists, and had a low response rate that prevents firm conclusions. Third, these results are from 2004, before the development of the core competencies. Last, these results differ from a 2005–2006 survey by SHM that was also limited by a low response rate, but revealed that 68% of hospitalist groups perform procedures.3 This work has an important message despite our concerns. It highlights the need for enhanced, competency-based procedural training for internal medicine residents, especially those pursuing a career in hospital medicine. If residents do not acquire skills needed to perform these procedures safely during training, they will be unsafe when expected to perform them in practice. Simulation-based education is a safe and effective method to boost physicians’ procedural skills. Simulation provides an opportunity for deliberate practice, improves skills, and reduces complications in core competency procedures including thoracentesis4 and CVC insertion.5 Simulation is endorsed by the American Board of Internal Medicine. Residents, general internists, and hospitalists all perform bedside procedures. What really matters is that they are evaluated rigorously and demonstrate the skills to perform these procedures safely.
Tobacco smoking policy and indoor air quality: a case study

Abstract Policy on environment tobacco smoke and its effect on indoor air quality are discussed in this paper. Passive (secondhand) smoke is examined in aspects ranging from health effects to laws surrounding smoking within public buildings in the United States. Engineering and administrative solutions to these indoor air quality problems are considered. A case study of a smoking area within an institutional building is presented and potential improvements and administrative actions are discussed. The results of this study should be helpful to those faced with or anticipating technical and legal indoor air quality problems and policy decisions.
Nonlinear optical studies of surface structures of rubbed polyimides and adsorbed liquid crystal monolayers

Abstract Sum-frequency generation (SFG) vibrational spectroscopy and second-harmonic generation (SHG) were used to probe rubbed polyimide (PI) surfaces and liquid crystal (LC) monolayers adsorbed on them. The results show that rubbing preferentially aligns PI backbones along the rubbing direction, but has little effect on the side chain orientation at the surface. However, adsorption of an LC monolayer well aligned by the rubbed PI surface can cause the side chains to tilt towards the rubbing direction.
Detailed molecular dynamics simulations of a model NaPSS in water.

Hydrophobic polyelectrolytes are known to form necklace-like structures of dense beads connected by strings of monomers. This structure appears as a result of optimization of the electrostatic and short-range interactions. To elucidate the effect of counterion condensation and solvent on polyelectrolyte conformations, we performed two sets of molecular dynamics simulations of model poly(styrene)-co-styrene sodium sulfonate (NaPSS) chains with the degree of polymerization N = 16−64 and fraction of charged monomers f = 0.25−1 in aqueous solutions: (1) water molecules were considered explicitly using the TIP3P-PME model and (2) water molecules were modeled as a dielectric continuum with the dielectric constant 77.73. Our simulations showed that with increasing fraction of sulfonated groups f a polystyrene sulfonate chain adopts an elongated conformation. There is a transition between collapsed and elongated states which is manifested in the change of the scaling dependence of the chain size on the degree of ...
Calcium-binding proteins MRP 8 and 14 in a Staphylococcus aureus infection model: role of therapy, inflammation, and infection persistence.

Abstract Concentrations of the calcium-binding proteins of the S100 family, myeloid-related proteins 8 and MRP 14 (MRP8/14), are elevated in chronic infections, yet the role of these proteins is not clearly defined. Using commercial and developed enzyme immunoassays, we assayed for MRP8/14 in sterile-filtered abscess fluid from tissue-cage-implanted rats and rabbits. Staphylococcus aureus abscesses were created 6 weeks after the intraperitoneal implantation of tissue cages. Leukocytes, bacteria, and non-protein-bound calcium and zinc were measured in the infection exudate at day 3 or 5 of infection and after 8 days of treatment with antimicrobials β-lactams (18 rabbits, 35 rats) and fluoroquinolone-rifampin (6 rabbits). Half of the infected rats were depleted of neutrophils; these rats exhibited significantly lower MRP 8/14 concentrations on all days sampled, regardless of the level of infection. The level of abscess MRP 8/14 is high early in the course of infection but decreases with effective antimicrobial treatment by as much as 100-fold. Thirty-day-old abscesses with log 6 bacterial counts and low neutrophil counts showed low concentrations of MRP 8/14 in these models. In abscess fluid, interleukin-6, as a representative marker of inflammation, correlated with MRP8/14, whereas ionized calcium and zinc did not. Our data suggest that infection and inflammation are not equal stimuli for MRP 8/14. The neutrophil appears to be the main source of MRP8/14 in this model. (J Lab Clin Med 2003;141:110-20)
Progress & perspectives for atomic-resolution electron microscopy

The transmission electron microscope (TEM) has evolved into a highly sophisticated instrument that is ideally suited to the characterization of advanced materials. Atomic-level information is routinely accessible using both fixed-beam and scanning TEMs. This report briefly considers developments in the field of atomic-resolution electron microscopy. Recent activities include renewed attention to on-line microscope control (‘autotuning’), and assessment and correction of aberrations. Aberration-corrected electron microscopy has developed rapidly in several forms although more work needs to be done to identify standard imaging conditions and to explore novel operating modes. Preparation of samples and image interpretation have also become more demanding. Ongoing problems include discrepancies between measured and simulated image contrast, concerns about radiation damage, and inversion of electron scattering.
Carnitine palmitoyltransferase-1A Deficiency: A Look at Classic and Arctic Variants

Carnitine palmitoyltransferase-1A (CPT-1A) deficiency is a defect of fatty acid metabolism that presents as an autosomal recessive inheritance. Carnitine palmitoyltransferase-1A is the rate-limiting enzyme that allows the body to process fats to provide energy during times of fasting and illness. Pa
Issues in mid-IR type-II interband cascade lasers

A new type of cascade laser, the so-called interband cascade laser based on type-II quantum well staircase structures, has been demonstrated recently. Here, we will discuss the design and modeling of the interband cascade lasers in connection with device performance. Normalized excess voltage and current will be introduced to evaluate how efficiently the input power is converted into the optical output power in the sense of the utilization of both injection current and applied voltage. Our modeling is based on Kane's eight-band k(DOT)p theory with envelope wave-function approximation and strain effects included. The calculated threshold current density, which includes contributions of radiative current, direct tunneling and Auger recombination, is significantly smaller than the experimentally observed value. This indicates that there are additional current leaking channels, which may be related to interface scattering and material defects, suggesting significant room for improvement. Our modeling also found that the device performance could vary substantially with temperature. Implications of our analyses and the modeling results will be interpreted in terms of carrier transport, optical gain and loss, as well as power efficiency.
Commentary on "Principal Stratification -- a Goal or a Tool?" by Judea Pearl

This commentary takes up Pearl's welcome challenge to clearly articulate the scientific value of principal stratification estimands that we and colleagues have investigated, in the area of randomized placebo-controlled preventive vaccine efficacy trials, especially trials of HIV vaccines. After briefly arguing that certain principal stratification estimands for studying vaccine effects on post-infection outcomes are of genuine scientific interest, the bulk of our commentary argues that the “causal effect predictiveness” (CEP) principal stratification estimand for evaluating immune biomarkers as surrogate endpoints is not of ultimate scientific interest, because it evaluates surrogacy restricted to the setting of a particular vaccine efficacy trial, but is nevertheless useful for guiding the selection of primary immune biomarker endpoints in Phase I/II vaccine trials and for facilitating assessment of transportability/bridging surrogacy.
Three-dimensional view of signal propagation in femtosecond four-wave mixing with application to the boxcars geometry

Maxwell's equations for the apparently complicated generation and propagation of femtosecond four-wave-mixing signals in optically thick samples can be solved by triple Fourier transformation into the three-dimensional (3D) frequency domain. Given the linear absorption and refractive-index spectra, the propagation problem can be solved in three dimensions under the assumption that nonlinear distortions of the excitation pulses can be neglected. A propagation function exactly incorporates the linear evolution of the excitation pulses, the nonlinear generation of the signal, and the linear propagation of the signal. A quantitative treatment of the directional filtering of the 3D susceptibility that arises from excitation with noncollinear pulses and selective interference detection of signal in one phase-matched direction is developed. This 3D treatment is used to examine the influence of phase-matching bandwidth, directional filtering, and sample absorption on femtosecond four-wave-mixing signals in the rectangular and square boxcars phase-matching geometries.
Scopolamine, amphetamine and light-reinforced responding

Behavior maintained by response-contingent illumination declines within the session. This decline is reversed by the anticholinergic, scopolamine, but not by the stimulant, amphetamine. These data may be related to earlier findings implicating acetylcholine (ACH) in habituation and in certain functions of the hippocampus.