cssi/SciSciGPT-SciSciNet huggingface dataset:
Plasticity in the adult human oligodendrocyte lineage

Preoligodendrocytes have been described in cultures and tissue prints of adult human white matter (Armstrong et al., 1992). To characterize further these precursors of human oligodendrocytes, we have investigated whether they express genes playing a critical role in oligodendrocyte development. In the intact human brain, platelet-derived growth factor receptor alpha (PDGF alpha R) and myelin transcription factor 1 (MyTI) transcripts are expressed in 1-2% of cells of the oligodendrocyte lineage (OL), and clusters of such cells can be found in the periventricular region. Myelin basic protein transcripts containing exon 2 information (exon 2+ MBP), which are characteristic of the premyelinating stage, are detected in 15-20% of OL cells in vivo. When OL cells are separated from human white matter and allowed to regenerate in vitro, a much larger proportion of these cells express developmentally regulated genes, while exon 2- MBP and proteolipid protein (PLP) transcripts characteristic of mature OL cells appear transiently downregulated. Basic fibroblast growth factor (bFGF), even in the presence of PDGF, does not promote DNA synthesis in these cultured OL cells. Yet bFGF induces human oligodendrocytes to regenerate their processes rapidly in vitro and to express O4 antigens as well as exon 2+ MBP, MyTI, and PLP transcripts. While bFGF accelerates early regenerative processes, it also maintains high expression of exon 2+ MBP transcripts in OL cells for up to 2 weeks in vitro. In contrast, high levels of insulin in the absence of bFGF allow accumulation of exon 2- MBP and PLP transcripts in most OL cells at 2-3 weeks in vitro. We propose that the myelinated human brain harbors a small pool of precursors of oligodendrocytes and that growth factor-regulated phenotypic plasticity rather than mitogenic potential accounts for the regeneration of oligodendrocytes in the initial stages of demyelinating diseases such as multiple sclerosis.
A comparison of swallowing in three subjects using an interactive image processing system

Using an interactive computer imaging processing system, three male subjects' liquid swallows are compared. The subjects are a 32-year-old diagnosed with amyotrophic lateral sclerosis, also known as Lou Gehrig's Disease, a 24-year-old normal and a 71-year-old normal. This study examines aspects of tongue and hyoid bone movement and upper esophageal sphincter opening during swallowing. Trajectories and ranges of motion are compared within and across the three subjects. A novel technique to facilitate simultaneous lingual and bolus tracking during videofluoroscopic recording of swallowing is reported. >
The role of configuration in the identification of visually degraded words.

Two experiments were carried out in which reaction time for identification of words in sets of four was measured. The words were of three letters, with dichotomous variation of the first and third letters, in either upper- or lowercase, with letters chosen to give maximum variation in word configuration in lowercase. Four types of display were used, differing in size and masking. In Experiment 1, the words were easy to identify in uppercase as well as in lowercase, because the letters were easily discriminable in either case, and the results showed no advantage to lowercase words at any level of degradation. In Experiment 2, the letters were more difficult to discriminate in uppercase, and with the most severe degradation, the words in lowercase were identified more rapidly than those in uppercase. Thus the reaction time results showed an advantage of the configural properties available in lowercase only with words difficult to identify in uppercase and with extreme amounts of degradation. Error analyses of both experiments showed that errors were made to individual letters, not on the basis of the configuration, for words in both cases. It is concluded that letter processing occurs even when there is evidence for the use of configural information, thus implying a predominant role of letter perception in word identification. Some reservation is expressed whether whole-word configuration is the only pertinent configural property and whether the results from such simple identification tasks are appropriate to an understanding of natural reading.
Ultrasensitivity part I: Michaelian responses and zero-order ultrasensitivity

Quantitative studies of signal transduction systems have shown that ultrasensitive responses – switch-like, sigmoidal input/output relationships – are commonplace in cell signaling. Ultrasensitivity is important for various complex signaling systems, including signaling cascades, bistable switches, and oscillators. In this first installment of a series on ultrasensitivity we survey the occurrence of ultrasensitive responses in signaling systems. We review why the simplest mass action systems exhibit Michaelian responses, and then move on to zero-order ultrasensitivity, a phenomenon that occurs when signaling proteins are operating near saturation. We also discuss the physiological relevance of zero-order ultrasensitivity to cellular regulation.
NMR relaxation rates for the spin-1/2 Heisenberg chain

The spin-lattice relaxation rate 1/${\mathit{T}}_{1}$ and the spin-echo decay rate 1/${\mathit{T}}_{2\mathit{G}}$ for the spin-1/2 antiferromagnetic Heisenberg chain are calculated using quantum Monte Carlo and maximum-entropy analytic continuation. The results are compared with recent analytical calculations by Sachdev. If the nuclear hyperfine form factor ${\mathit{A}}_{\mathit{q}}$ is strongly peaked around q=\ensuremath{\pi}, the predicted low-temperature behavior [1/${\mathit{T}}_{1}$\ensuremath{\sim}${\mathrm{ln}}^{1/2}$(1/T), 1/${\mathit{T}}_{2\mathit{G}}$\ensuremath{\sim}${\mathrm{ln}}^{1/2}$(1/T)/\ensuremath{\surd}T] extends up to temperatures as high as T/J\ensuremath{\approxeq}0.5. If ${\mathit{A}}_{\mathit{q}}$ has significant weight for q\ensuremath{\approxeq}0 there are large contributions from diffusive long-wavelength processes not taken into account in the theory, and very low temperatures are needed in order to observe the asymptotic T\ensuremath{\rightarrow}0 forms.
Fusion Curve of Iron to 96,000 Atmospheres: Temperature of the Earth's Core

A NUMBER of arguments have been advanced1 tending to show that the boundary of the Earth's core is molten iron, and the central part of the core is solid iron. If the Earth's core is composed of iron the solid phase of which near the melting point is the same as that at the surface, then a determination of the melting point of iron at about 1.4 × 106 atmospheres (the pressure at the boundary between the mantle and the liquid core) would set a minimum temperature for this depth within the Earth.
Comparison of anthropogenic hydrocarbon inputs to two subtropical marine estuaries

Abstract Anthropogenic and biogenic hydrocarbons have been determined in approximately 160 sediments, organisms and water samples from Tampa Bay, Florida, a highly urbanized and industrialized subtropical estuary. Results are compared with data from a similar study in Charlotte Harbor, Florida, a relatively unimpacted estuary 93 km south of Tampa Bay. Sedimentary hydrocarbon concentrations in both summer (5–30 μg/g) and winter (0–5 μg/g) are similar in the two estuaries, although levels in both subtropical systems are generally much lower than in most temperate estuaries. We postulate that this difference is the result of both larger average grain size and higher annual temperatures in the subtropical estuaries. “Hot-spots” of localized anthropogenic inputs were observed in both subtropical systems but decreased rapidly both vertically and laterally in the sediments.
SSRIs, adolescents, and aggression: tempering human implications regarding SSRI-induced aggression in hamsters: comment on Ricci and Melloni (2012).

The safety and efficacy of selective serotonin reuptake inhibitors (SSRIs) in adolescents is a topic of great import, complexity, and controversy. Conflicting evidence derived from clinical trials, translational research, and basic science demands that investigators in the field use critical thinking in the synthesis of evidence from varying sources. The new study by Ricci and Melloni presented in the current issue of this journal shows that exposure to low-dose fluoxetine during adolescence predisposes Syrian hamsters to offensive aggression, with demonstrable neurophysiologic changes. This work adds to the understanding of the mammalian neuropathways of aggression, but is limited in its direct generalizability to human adolescent clinical populations. (PsycINFO Database Record (c) 2012 APA, all rights reserved). Language: en
The Kokeshi Doll: A Tool for Family Supervision.

Family supervision is an active process of increasing a supervisee 's ability to successfully counsel with families. The use of Kokeshi dolls allows the supervisee to focus on conceptualization, personalization, and pro- cess skills. A case study illustrates how Kokeshi dolls enhance the supervision process.
Calculated intensity of high-energy neutron beams

Abstract The flux, energy and angular distributions of high-energy neutrons produced by in-flight spallation and fission of a 400 MeV / A 238 U beam and by the break-up of a 400 MeV / A deuteron beam are calculated. In both cases very intense secondary neutron beams are produced, peaking at zero degrees, with a relatively narrow energy spread. Such secondary neutron beams can be produced with the primary beams from the proposed rare isotope accelerator driver linac. The break-up of a 400 kW deuteron beam on a liquid-lithium target can produce a neutron flux of >10 10 neutrons / cm 2 / s at a distance of 10 m from the target.
The discovery of marijuana use by a parent of an early adolescent.

CASE Philip, a 14-year-old male, is brought to your office by his anxious parents who recently discovered that he was using marijuana. Over the past 2 months, he has appeared moody, irritable, and has been losing interest in his school work. His parents had attributed these behavior changes to “teenage years” until his mother discovered a marijuana cigarette in his room. His father responded with anger directed at the youth. Philip had a happy and productive childhood before this event. He was a solid “B” student with several friends and a modest interest in participatory sports. He has two older siblings in college. The family was close and previously had enjoyed time together. Philip’s father stated that the use of drugs was absolutely forbidden in his family, and he felt that Philip had “let ‘him’ down.” The journey through adolescence is an eventful time for clinicians, parents, and youth. the youngster has a multitude of developmental experiences in her/his educational, social, sexual and psychological life for the first time. The discovery of drug use by a concerned parent in this case illustrates one of those new events. Both Drs. Schonberg and Heyneman approach this case from a contextual and developmental perspective. Dr. Heyneman cautiously differentiates “drug use” from a “primary drug problem.” Dr. Schonberg emphasizes the importance of knowledge about the epidemiology of drug use, i.e., experimentation in early adolescence must be seen as a problem worthy of careful clinical evaluation. For each clinician, the evaluation is guided by a need to understand the marijuana use in the context of the youngster’s previous medical and psychological history, his educational performance, social skills, and family patterns. Both commentators agree that, without more information, it would be premature to conclude that Philip’s case is consistent with a developmental phase with drug experimentation. Dr. Heyneman’s review of specific criteria that may differentiate a minor drug problem from a major one is especially helpful for the primary care clinician. The decision to refer for further evaluation and counseling is difficult. Availability of services (financial and geographic factors) and willingness of the patient and family to follow through on a referral are critical issues. Some pediatricians with special interest and training in adolescent developmental problems may be qualified to manage a patient like Philip when the initial evaluation suggests that the problem is limited to drug experimentation in a youth who is functioning well in other spheres.
Numerical simulations of dating young groundwater with multiple atmospheric tracers: CFC-11, CFC-12, SF6, 3H/3He and 85Kr

Dating groundwater with atmospheric tracers is becoming an important technique for investigating hydrologic systems. Because the groundwater age dated by a single tracer generally involves high uncertainty and the multiple-tracer approach is assumed to be much more reliable due to cross-validation, the multiple- tracer has recently become the suggested technique. However, the numerical methods used for simulating groundwater ages based on multiple tracers' concentrations are limited. In addition, the multiple-tracer method requires many evaluations before applications can be considered reliable. In this study, we use a rigorous modeling approach, which relies on the backward-in-time random walk particle tracking solutions of the adjoint of the forward advection-dispersion equations, to simulate the groundwater ages. The atmospheric tracers we selected include Chlorofluorocarbons, sulfur hexafluoride, tritium/helium and krypton 85. In this analysis we build multiple detailed, three-dimensional geostatistical realizations representing complex subsurface heterogeneity. Then we simulate the backward-in-time transport of multiple tracers from the capture monitoring wells to the water table, by considering the advection, mechanical dispersion, molecular diffusion and radiactive decay of tracers represented by high-resolution particles in numerical models. Then the multiple-tracer approach is evaluated systematically by considering various distributions of groundwater age underlying a single water sample. Results show that the simulated Chlorofluorocarbonbased ages match the measured ones. Results also show that there is apparent discrepancy between ages dated by different tracers. This discrepancy could contribute to the decreased reliability of the multiple-tracer approach or cause misleading results. The dating discrepancy between multiple tracersresults from the variations of growth rate of the historic atmospheric tracer concentration at different recharge ranges. Therefore, the multiple-tracer dating approach is not appropriate, for cross-validation unless we are aware of this discrepancy.
Leader Turnover, Institutions, and Voting at the UN General Assembly:

Using evidence from voting in the UN General Assembly (UNGA), this article shows that leader turnover, especially in small coalition, nondemocratic systems, increases the likelihood of policy reali...
Medical genetics diagnostic evaluation of the child with global developmental delay or intellectual disability

Purpose of reviewThe review addresses the recent discovery of large-scale copy number variations in the human genome and advances in microarray technology which together have changed the clinical genetic diagnostic approach for children with global developmental delay.Recent findingsSeveral publicat
Comparison of Mass Selection, Crossbreeding, and Hybridization for Improving Growth of Channel Catfish

Abstract The fastest-growing catfish populations resulting from mass selection, intraspecific crossbreeding, and interspecific hybridization were compared for growth rate. Kansas select (KS) and female Marion x male Kansas (MK) channel catfish (Ictalurus punctatus) were compared to three populations of female channel catfish x male blue catfish (I. furcatus) (CB) hybrids. Growth rate was evaluated during the first two seasons of growth in earthen ponds. The MK and KS fish grew faster to 100 g (P < 0.05) than CB fish during the first season, but CB fish grew faster than MK and KS fish during the second season. When the fish were harvested at the end of the second season, CB fish were slightly larger (1.3%) than KS fish, but did not differ in body weight from MK fish. Differences in body weight were also found among CB hybrids produced from different parental strains or families. The fastest-growing fish were MK x Auburn select blue catfish. Survival of the hybrids was higher than that of KS and MK fish.
Comparison of CH4/H2 and C2H6/H2 inductively coupled plasma etching of ZnO

Abstract CH4/H2-based discharges are attractive for dry etching of single crystal ZnO because of their non-corrosive nature. We show that substitution of C2H6 for CH4 increases the ZnO etch rate by approximately a factor of 2 both with and without any inert gas additive. The C2H6/H2/Ar mixture provides a strong enhancement over pure Ar sputtering, in sharp contrast to the case of CH4/H2/Ar. The threshold ion energy for initiating etching is 42.4 eV for C2H6/H2/Ar and 59.8 eV for CH4/H2/Ar. The etched surface morphologies were smooth, independent of the chemistry and the Zn/O ratio in the near-surface region was unchanged within experimental error after etching with both chemistries. The plasma etching improved the band-edge photoluminescence intensity and suppressed the deep level emission from the bulk ZnO under our conditions, due possibly to removal of surface contamination layer.
Process Research and Development of an NK-1 Receptor Antagonist. Enantioselective Trifluoromethyl Addition to a Ketone in the Preparation of a Chiral Isochroman

CJ-17,493 (4) is a chiral NK-1 receptor antagonist. It was first prepared through a diastereoselective crystallization, then through chiral chromatography of a key intermediate, and ultimately via asymmetric synthesis. Multiple routes for the preparation of a key isochroman were demonstrated, and conditions for improved regioselectivity of a Friedel–Crafts acylation were identified. Cesium fluoride was found to be an acceptable initiator for the generation of a nucleophilic trifluoromethyl anion from CF3TMS. A cinchonine-derived catalyst was identified for the enantioselective addition of the trifluoromethyl group to the ketone, and it was found that the product of the addition would be converted directly to the isochroman by treatment with t-BuOK. A Duff reaction was used for the formylation, and the resulting aldehyde was coupled to amine 5 to afford CJ-17,493 (4).
The Diffusion of Support for Same-Sex Marriage in the US Senate

Advocates for same-sex marriage have had much to celebrate. The last few years have shown that state after state and senator after senator have declared their support for full marriage equality. Such momentum suggests that their goals will be realized sooner rather than later. In this article, we analyze when senators announce their support for same-sex marriage. Contrary to the popularly held belief that their decisions will quickly snowball into filibuster-proof numbers, we find that most of the easy successes have already been achieved. The difficulty of securing the last few votes may take much longer.
Gastric emptying of enteric-coated tablets.

To evaluate the gastric emptying time of pharmaceutical dosage forms in a clinical setting, a relatively simple dual-radionuclide technique was developed. Placebo tablets of six different combinations of shape and size were labeled with indium-111 DTPA and enteric coated. Six volunteers participated in a single-blind and crossover study. Tablets were given in the morning on a fasting stomach with 6 oz of water containing99mTc pertechnetate and continuously observed with a gamma camera. A scintigraph was obtained each minute. The results suggested that the size, shape, or volume of the tablet used in this study had no significant effect in the rate of gastric emptying. The tablets emptied erratically and unpredictably, depending upon their time of arrival in the stomach in relation to the occurrence of interdigestive myoelectric contractions. The method described is a relatively simple and accurate technique to allow one to follow the gastric emptying of tablets.
Diagnostic tools used in the calibration and verification of protein crystallography synchrotron beam lines and apparatus

Diagnostic tools have been developed for use at the Structural Biology Center beam lines at the Advanced Photon Source. These tools are used in the calibration and operating verification of these synchrotron X-ray beam lines and constituent equipment.
The human female orgasm: critical evaluations of proposed psychological sequelae

Orgasm is assumed to be the height of sexual pleasure, reinforcing the recurrence of sexual behaviors. Surprisingly, data supporting the role of orgasm as a reward in women appear lacking. The most likely psychological function of orgasm in women, consistent with the very limited empirical information, is as a secondary reinforcer. In other words, sexual arousal is the primary reward for sexual behavior in women and orgasm associates sexual arousal with the partner. Data from a small (n = 38 women) pilot are presented to highlight the challenges of studying female orgasm. Challenges include differentiating vaginally- or clitorally-generated orgasms by self-report and the large proportion of women who are unsure if they experience orgasms. Finally, the recent spate of publications purporting to show differences in penile-vaginal intercourse induced orgasms is critiqued in light of the information reviewed.
Conformational Preferences in the Transition States and Tetrahedral Intermediates of Transacylations. Relationships to Enzyme-Bound Conformations of Phosphonate Inhibitors of Lipases and Esterases

The mechanism of the transacylation reaction of methyl acetate with methoxide has been explored using density functional theory (B3LYP/6-31+G(d)) and PCM−UAKS solvation models. The conformations of all of the transition states and intermediates are strongly influenced by the anomeric effect. The conformations of phosphonates were computed and analyzed. The bound inhibitors obtained from X-ray crystallographic structures of lipases and esterases adopt a few specific conformations. The conformers of the transition states and intermediates in transacylations are compared to the conformations of the phosphonate inhibitors. Although the energy differences are small, the frequency of the occurrence of the phosphonate conformers in crystal structures is more closely related to the relative energies of free phosphonate conformers than to the relative energies of acylation transition states.
Solar energy concentrating reactors for hydrogen production by photoelectrochemical water splitting

The use of solar energy to produce hydrogen by electrolysis is one potential renewable hydrogen source to fuel a future hydrogen economy. A cost-effective, renewable source of hydrogen is needed to reduce the emissions of carbon dioxide that occur with hydrogen-production methods utilizing fossil fuels. This report describes the design, construction, and testing of simple and inexpensive photoelectrochemical (PEC) reactors capable of producing hydrogen via water electrolysis using solar energy. We measured the light-focusing properties of two types of PEC reactors with curved surfaces and containing a clear aqueous fluid that resulted in the focusing of solar irradiance within the reactor. One reactor was a teardrop shaped plastic-film bag reactor, and the other was an acrylic spherical tank reactor. The spherical tank reactor had the best light-focusing properties, with up to a factor of 3.7 increase in the solar energy (and thus hydrogen production) for PEC cells mounted at the optimal point within the reactor electrolyte.
Geometrical Design of a Scalable Overlapping Planar Spiral Coil Array to Generate a Homogeneous Magnetic Field

We present a design methodology for an overlapping hexagonal planar spiral coil (hex-PSC) array, optimized for creation of a homogenous magnetic field for wireless power transmission to randomly moving objects. The modular hex-PSC array has been implemented in the form of three parallel conductive layers, for which an iterative optimization procedure defines the PSC geometries. Since the overlapping hex-PSCs in different layers have different characteristics, the worst case coil-coupling condition should be designed to provide the maximum power transfer efficiency (PTE) in order to minimize the spatial received power fluctuations. In the worst case, the transmitter (Tx) hex-PSC is overlapped by six PSCs and surrounded by six other adjacent PSCs. Using a receiver (Rx) coil, 20 mm in radius, at the coupling distance of 78 mm and maximum lateral misalignment of 49.1 mm ( 1/√3 of the PSC radius) we can receive power at a PTE of 19.6% from the worst case PSC. Furthermore, we have studied the effects of Rx coil tilting and concluded that the PTE degrades significantly when θ > 60° . Solutions are: 1) activating two adjacent overlapping hex-PSCs simultaneously with out-of-phase excitations to create horizontal magnetic flux and 2) inclusion of a small energy storage element in the Rx module to maintain power in the worst case scenarios. In order to verify the proposed design methodology, we have developed the EnerCage system, which aims to power up biological instruments attached to or implanted in freely behaving small animal subjects' bodies in long-term electrophysiology experiments within large experimental arenas.
Safety events during an automated telephone self-management support intervention.

Background: Interactive health information technology (HIT) can support the complex self-management tasks for diabetes. However, less is known about between-visit interactions and patient safety among chronic illness patients treated in the outpatient setting. Methods: We classified 13 categories for safety events and potential safety events within a larger trial evaluating a multilingual automated telephone self-management support system for diabetes using interactive voice response. Participants could trigger safety concerns by reporting hyperglycemia or hypoglycemia, inability to obtain medications, medication nonadherence and side effects, and needing appointments and/or supplies. We then examined these triggers across patient demographic and health characteristics to determine which patients were most likely to experience safety events. Results: Overall, there were 360 safety triggers that occurred among 155 participants, which represented 53% of individuals and 7.6% of all automated calls over the 27-week intervention. The most common triggers were for pain or medication side effects (22%) and not checking blood sugars (13%). In adjusted models, race/ethnicity and language were related to safety triggers; Spanish-speaking participants were significantly ( p = .02) more likely than English-speaking participants to experience a safety trigger, and black participants were marginally more likely (p = .09) than white participants to experience a safety trigger. Conclusion: About half of patients enrolled in a self-management technology intervention triggered at least one potential safety event over the course of the trial, and this was more frequent among some patients. Systems implementing HIT strategies to improve self-care and remote monitoring should consider specific program design elements to address these potential safety events.
Biocatalysis with Sol-Gel Encapsulated Acid Phosphatase.

This experiment was performed in an upper-level undergraduate biochemistry laboratory course. Students learned how to immobilize an enzyme in a sol−gel matrix and how to perform and evaluate enzyme-activity measurements. The enzyme acid phosphatase (APase) from wheat germ was encapsulated in sol−gel beads that were prepared from the precursor molecule tetramethoxysilane. The enzymatic activities of free and immobilized APase were measured with a colorimetric assay that monitors the formation of p-nitrophenolate from p-nitrophenylphosphate. Students critically assessed the advantages and disadvantages of sol−gel based enzyme immobilization by investigating the catalytic performance, the enzyme retention, and the reuse capability of the APase sol−gel beads. This experiment exposed students to thoughts and techniques that are important for the biotechnological application of enzymes.
Control of large decentralized dynamic systems

The nature of information flow in arriving at optimal control signals is examined for decentralized linear dynamic systems with local and supervisory controllers. It is illustrated for problems with quadratic cost subject to terminal (target) state constraint. It is assumed that local controllers know only their own dynamics and subsystem state vectors and that the supervisory control knows the target state vector and the dynamic and control coupling terms that exist between the subsystems. It is further assumed that the controllers can exchange intermediate results of computations in deriving control laws for the decentralized systems.
Preschool-age children and adults flexibly shift their preferences for auditory versus visual modalities but do not exhibit auditory dominance.

The goal of this study was to evaluate the claim that young children display preferences for auditory stimuli over visual stimuli. This study was motivated by concerns that the visual stimuli employed in prior studies were considerably more complex and less distinctive than the competing auditory stimuli, resulting in an illusory preference for auditory cues. Across three experiments, preschool-age children and adults were trained to use paired audio–visual cues to predict the location of a target. At test, the cues were switched so that auditory cues indicated one location and visual cues indicated the opposite location. In contrast to prior studies, preschool-age children did not exhibit auditory dominance. Instead, children and adults flexibly shifted their preferences as a function of the degree of contrast within each modality, with high contrast leading to greater use.
The effects of local anaesthetics on retinal function

Abstract Isolated frog eyecups were incubated in Ringer containing local anaesthetics to study the effects of these drugs on dark-adaptation of the ERG. Relative to controls, dark-adaptation in eyecups treated with millimolar concentrations of MS-222, benzocaine, and procaine HCl was significantly inhibited during 10 to 120 min following the cessation of the adapting light. These drugs also prevented the recovery of the c -wave during dark-adaptation, resulting in ERG waveforms resembling those found in light-adapted eyecups. Measurements of rhodopsin in the retina were consistent with previous findings showing that rhodopsin regeneration in situ is inhibited by local anaesthetics. In vitro regeneration experiments in which bleached rod outer segment fragments were added to 11- cis retinal showed that preincubation of retinal with MS-222 in ethanol prevents rhodopsin regeneration. Evidence was obtained spectrophotometrically for the formation of a complex between MS-222 and 11- cis retinal with a λ max of 512 nm. We propose that the formation of a Schiff's base between these two compounds blocks the recombination of rhodopsin, and in situ , leads to the inhibition of dark-adaptation.
Neural Isolation of the Jejunoileum: Effect on Tissue Morphometry, Mucosal Disaccharidase Activity, and Tissue Peptide Content

Abstract The aim of this study was to determine the effects of a model of intestinal extrinsic denervation on mucosal structure and function. Six dogs underwent in situ neural isolation of the jejunoileum (Group 2); six other dogs served as operated controls (Group 1), and five nonoperated dogs were naive controls (Group 3). Thirty-centimeter segments of proximal jejunum and distal ileum were excised before (time zero) and at 2 weeks and 8 weeks postoperatively in Groups 1 and 2, while similar regions were removed at time zero in Group 3. Tissues were analyzed for morphology with quantitative morphometry, mucosal disaccharidase activities (sucrase, maltase, and lactase), and tissue content of selected regulatory peptides in transmural, mucosa/submucosa, and muscularis regions.In situneural isolation had no significant or consistent effects on morphology/morphometry or on mucosal disaccharidase activities. Tissue content of neuropeptide Y decreased markedly (P
31P magnetic resonance spectroscopy is sensitive to tumor hypoxia: perfusion and oxygenation of rat 9L gliosarcoma after treatment with BCNU.

The mechanism behind the relative increase in high-energy phosphates observed by MRS in many tumors following chemotherapy is poorly understood. To test the hypothesis that this metabolic activation is associated with a decrease in tumor hypoxia, tumor blood flow and oxygenation were measured in tumors that were also analyzed by MRS. 31P MR spectra were acquired with a GE 2T CSI spectrometer from subcutaneous 9L tumors in rats 4 days following treatment with BCNU (10 mg/kg) and from age-matched sham-treated control tumors. BCNU-treated tumors (n = 13) underwent a significant improvement in bioenergetic state compared to control tumors (n = 14), showing a relative increase in high-energy phosphate (Pi/phosphocreatine) (p<0.01), and a relative decrease in Pi (Pi/a nucleoside biphosphate) (p<0.01). Gamma camera imaging of 133Xe washout, following injection of 133Xe in saline into control and treated 9L tumors 4 days after treatment, was used to measure tumor perfusion. Sham-treated control tumors (n = 21) were perfused at a rate of 35.4 (±6.4 SE) mL/100g/min, while BCNU-treated tumors (n = 20) were perfused at a rate of 55.1 (±7.5 SE) mL/100g/min (T = 1.96; p <0.05). The partial pressure of oxygen (pO2), measured with a polarographic electrode was found to be significantly higher in treated 9L than in sham-treated controls. Mean tumor pO2 of sham-treated tumors was 18.1 (±1.7 SE) mmHg (n = 00 measurements in six tumors) while mean pO2 of treated tumors was 45.1 (±2.1 SE) mmHg (n = 500 in five tumors) (T = 10.12; p<0.001). If the range 0-5 mmHg is taken to approximate the hypoxic fraction, then control tumors are ±23% hypoxic, while treated tumors are only 2% hypoxic. These data suggest that metabolic activation of tumors following therapy may be associated with decreased tumor metabolic hypoxia.
Restriction fragment length polymorphism evaluation of six peanut species within the Avachis section.

Restriction fragment length polymorphisms (RFLP) were assessed among accessions within six peanut species of the Arachis section: tetraploid cultivated species, A. hypogaea; tetraploid wild species, A. monticola; and four diploid wild species, A. batizocoi,A. cardenasii, A. duranensis and A. glandulifera. While the two tetraploid species did not show polymorphism with 16 PstI-generated random genomic probes, two of seven seed cDNA probes detected polymorphisms. The RFLP variation detected by two seed cDNA probes appeared to be related to structural changes occurring within tetraploid species. The botanical var. ‘fastigiata’ (Valencia market type) of A. hypogaea subspecies fastigiata was shown to be the most variable. Arachis monticola was found to be more closely related to A. hypogaea subspecies hypogaea than to subspecies fastigiata. Diploid species A. cardenasii, A. duranensis, and A. glandulifera showed considerable intraspecific genetic diversity, but A. batizocoi showed little polymorphism. The genetic distance between the cultivated peanut and wild diploid species was found to be closest for A. duranensis.
Optimization of Electrodynamic Energy Transfer in Coilguns With Multiple, Uncoupled Stages

A 1-D model for inductive electromagnetic acceleration of projectiles using a coilgun has been nondimensionalized to find relevant scaling parameters. The dynamic impedance parameter, representing the ratio of the resonant period of the unloaded electrical circuit to the time the projectile is electromagnetically coupled to the coil, is the scaling term that can be adjusted to optimize the electromagnetic energy transfer process. The mutual inductance profile, which represents the ability to convert potential electromagnetic energy into projectile kinetic energy, was modeled for a specific geometry using a semi-empirical function previously found suitable for cylindrical pulsed inductive plasma accelerators. Contour plots representing coilgun efficiency were generated for varying initial projectile velocity across a range of dynamic impedances. The contour plots show that below a given initial velocity a dynamic impedance parameter can be selected to maximize energy transfer to the projectile. This optimum varies as a function of the initial velocity a projectile possessed when it enters the coilgun stage. Once the contour plot is generated for a geometry it can be used to optimize the acceleration process for any stage in a coilgun if the individual coils comprising the stages are electromagnetically uncoupled from each other and the velocity of the projectile as it exits the previous stage is known.
Green's-function updating for Monte Carlo simulation of constrained fermions.

Green's-function updating is introduced in the recently developed quantum Monte Carlo algorithm for constrained fermions, thus making the computing time scale in the same way as the ordinary quantum Monte Carlo algorithm. Stabilization routines are also implemented, with limited success in lowering down the simulation temperature.
Size distributions of trace metals in the Los Angeles atmosphere

Abstract Particle size distributions of Fe, Pb, Mz, Zn, Cu and Ni were measured at two locations in the Los Angeles area during the winter and summer of 1989 using a cascade impactor. Measures were taken to minimize particle bounce and elemental analysis was performed by X-ray fluorescence. Measured Fe size distributions were consistent, with suspended dust being the major source. Pb distributions were observed to be multimodal with modes due to automotive emissions, particle growth and suspended dust. The importance of suspended dust was investigated using Fe as tracer and suspended dust ratios of Fe to Pb and other metals. Mn distributions were observed to be similar to those of Pb with automotive emissions and suspended dust being important sources. Particle size distributions of Zn, Cu and Ni showed significant amounts of these metals to be persent in particles less than 1μm in diameter, indicating anthropogenic sources. Suspended dust was found to be an important source of Zn, but not of Cu or Ni, in particles with diameters greater than 2 μm.
Cooperativity and slow transitions in the regulation of oligomeric and monomeric enzymes

Ligand-induced slow transitions (e.g., isomerizations) between different functional states (conformations) of an enzyme (a) have been observed in a number of key regulatory enzymes, (b) can account for kinetic cooperativity of even a monomeric enzyme with a single catalytic site, and (c) can be an alternative to site-site interactions (rapid interactions between substrate binding sites on different subunits) as an explanation for kinetic cooperativity of a multisubunit enzyme.
Rapid breakthrough measurement of void volume for field-flow fractionation channels.

Abstract A peak breakthrough technique is described and evaluated for measuring the void volume of field-flow fractionation (FFF) channels, particularly those used for flow FFF. This technique uses a high-molecular-mass macromolecular or particulate probe that can be displaced rapidly by flow through the FFF channel with minimal transverse diffusion. The particles that emerge first are those carried through the entire length near the channel at the apex of the parabolic flow profile. These particles generate a sharp breakthrough profile. The measured breakthrough time is two thirds of the void time, thus making it possible to calculate both the void time and the associated void volume. This method, although applicable to all FFF channels (and capable of extension to open tubes), is particularly useful for flow FFF because conventional low-molecular-mass void probes can diffuse into the permeable wall and thus distort void measurements. The theoretical basis of the breakthrough technique and an explanation for the sharpness of the breakthrough front are given. A method for compensating for deviations from perfect sharpness is developed in which the breakthrough time is identified with the time needed to reach 85–88% of the breakthrough peak maximum. Preliminary experimental results are shown using various protein probes in four different FFF channel systems.
An expectation-maximization algorithm for space-time sparsity regularization of the MEG inverse problem

Abstract We present a framework for “space-time sparsity” (STS) regularization in the MEG inverse problem via maximization of an appropriately penalized likelihood function. STS is based on the physiological perspective that the true brain activity over a given time span is likely to involve a set of spatially and temporally local events. We employ spatial and temporal bases to represent these local events and use a penalty function to favor solutions involving only a few space-time events. Space-time sparse solutions are achieved by penalizing only the largest coefficient associated with each space-time event. We adapt the Expectation Maximization (EM) Algorithm to solve the penalized likelihood problem and illustrate the potential of our method using simulated data.
Use of the telephone by pediatric house staff: A technique for pediatric care not taught

Summary Pediatric house staff had difficulty taking an adequate telephone history when given a complaint of cough, vomiting, diarrhea, or rash. Increased time in training did not seem to improve history taking. Those responsible for pediatric training programs need to consider instructing house staff in the use of the telephone.
Phenotypic Assays for β-Amyloid in Mouse Embryonic Stem Cell-Derived Neurons

Summary Given the complex nature of Alzheimer's disease (AD), a cell-based model that recapitulates the physiological properties of the target neuronal population would be extremely valuable for discovering improved drug candidates and chemical probes to uncover disease mechanisms. We established phenotypic neuronal assays for the biogenesis and synaptic action of amyloid β peptide (Aβ) based on embryonic stem cell-derived neurons (ESNs). ESNs enriched with pyramidal neurons were robust, scalable, and amenable to a small-molecule screening assay, overcoming the apparent limitations of neuronal models derived from human pluripotent cells. Small-molecule screening of clinical compounds identified four compounds capable of reducing Aβ levels in ESNs derived from the Tg2576 mouse model of AD. Our approach is therefore highly suitable for phenotypic screening in AD drug discovery and has the potential to identify therapeutic candidates with improved efficacy and safety potential.
Loss and repair of glucose-disposal mechanism in dog fed fructose as sole dietary carbohydrate.

Summary1. Our earlier observation in the rat, that the feeding of fructose as sole carbohydrate results in a considerable loss in the animal's capacity to dispose of ingested glucose, is confirmed in another species, the dog. It is also shown that galactose is not the equal of fructose in bringing about impairment in glucose-disposal mechanism. 2. Feeding of a single meal containing 18 g of glucose/kg body weight failed to restore to normal the glucose-disposal mechanism once it was impaired by fructose feeding. A normal capacity for glucose disposal was observed after the dog had ingested 3 glucose-containing meals.
Robust and secure two-dimensional barcode system

We present a 2-D barcode technique that can be used to authenticate documents. The proposed system holds much more information than one-dimensional barcode. It is robust against different types of noises and distortions. We use double phase encoding to encode information into the 2-D binary barcode. As a result, the technique is secure against unauthorized detection. We present analysis for the system performance using the statistical properties of double-phase encoding. The algorithm is tested under several types of noise and distortions, for example, additive noise, geometric distortion, fading, scratches, and occlusion. We compare the performance of amplitude-based double phase encoding and fully phase double phase encoding with that of an ordinary 2-D barcode with error-correcting code. Computer simulations and optical experiments are presented to test the robustness of the proposed method.
An Emission-Based Feedback System for Stabilizing an Inductively Coupled Plasma

An emission-controlled feedback system for stabilizing an ICP has been investigated. Unlike previous stabilization methods which monitor only the power being sent to the plasma, the present one uses an emission signal from either argon or an internal reference element as a stability indicator. Using a previously constructed power-modulation circuit for rf power control, the feedback network adjusts the plasma power to compensate for changes in the emission level of the reference element. It is shown to be particularly useful for reducing or eliminating the drift that occurs when the plasma is warming up. A key point for successful operation of the feedback arrangement is that both the feedback-signal and the analysis photometric systems must receive light from exactly the same region of the plasma. Also, the excitation energy and ionization characteristics of the reference element should be comparable to those of the desired analyte. Results with several combinations of argon, barium, calcium, iron, manganese, sodium, and strontium lines are presented.
Comparing the welfare effects of income and excise taxes in the presence of the other taxation paradox

This paper implements numerically a general equilibrium model in which all private producers are price makers and the government utilizes tax revenues to provide a public good. After deriving the partial equilibrium condition for an excise tax to increase price by more than the tax (for a monopoly firm), numerical examples are given, demonstrating this phenomenon for both partial and general equilibrium. In the general equilibrium context, optimal excise taxation and optimal flat-rate income taxation are compared. In the excise tax regime, prices increase by more than the taxes. In the income tax regime, prices actually decline relative to the no-tax regime. In all of the examples given, flat-rate income taxation is superior to excise taxation in terms of welfare.
Soil Humic Acid as a Hydroxypolystyrene: A Biochemical Hypothesis

THE stable humic acid of soil has an unknown chemical structure; it is considered to be a complex phenolic polymer formed from unknown biological precursors1. This article presents the hypothesis that hydroxystyrenes formed under natural conditions may play an important part in forming soil humic acid. This concept followed on the finding that hydroxystyrenes are produced during bacterial decarboxylation of certain phenolic acids of plant origin (4-hydroxycinnamic acids)2 and the realization that soil humic acid in many of its described properties resembles oxidized polystyrenes.