cssi/SciSciGPT-SciSciNet huggingface dataset:
New Approximation for the Calculation of Neutron Scattering from a Simple Liquid

A conceptually simple and easily applied approximation is made for the Van Hove distribution function $G(\mathbf{R},t)$ of a classical liquid. This approximation gives a less rapid temporal decay of $G(\mathbf{R},t)$ than is found in the Vinevard convolution approximation. In addition, by requiring that the sum rules be satisfied, we find that for $t$ smaller than about 0.5 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}13}$ sec the "correlations" in a liquid may be said to be increasing. Comparisons are made with recent neutron scattering experiments. There is fair agreement between the theoretical and experimental results.
Microfabrication of an integrated SU-8 waveguide with an embedded focusing lens for application in single-molecule detection (SMD)

This paper reports a research effort to design, microfabricate, and test a uniquely designed waveguide technology with integrated micro-lenses in vertical orientations. The waveguide and integrated focusing lenses were microfabricated using thick photo-resist such as SU-8 with UV-light lithography. The waveguide can be used in various biological and biomedical systems.
Excess radon in the Santa Barbara basin

Two excess-radon profiles were measured in the Santa Barbara basin in July and November, 1970. The November profile, with a maximum excess at 25 m above the bottom, is a transient profile probably produced by a turbidity current. The July profile, with excess radon decreasing exponentially upward, is treated as a stationary profile which gives a vertical eddy coefficient of 3.9 cm 2 /sec, based on a simple steady-state diffusion model.
The effect of pressure on the properties of germanium and silicon

Abstract Measurements of the pressure dependence, in germanium and silicon, of the intrinsic resistivity, the fundamental absorption edge, the carrier mobilities, the magnetoresistance coefficients, and the dielectric constant are reviewed, and an explanation based on the shift of the band edges presented. Experimental evidence for similar behavior of corresponding band extrema in germanium, silicon and the intermetallics is given. The cases of the (111) and (100) minima in germanium and silicon and the Ge-Si alloys are discussed in detail. The results of measurements of the change of ionization energy of shallow and deep lying impurity levels in germanium and silicon are also reviewed.
Nonparametric estimation of some quantities of interest from renewal theory

In this paper, confidence intervals are given for two quantities of importance related to renewal processes. For each quantity, two confidence intervals are discussed. One confidence interval is given for general, all-purpose use. Another confidence interval is given which is easier to compute, but not of general use. The case where data are subject to right censorship is also considered. Some numerical comparisons are made. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 638–649, 2003.
The teacher-innovator: Models of teaching as the core of teacher education

A design for teacher education has been made around the concept of providing teacher trainees with the theoretical understanding of the major models of teaching and the clinical competence to employ them in the classroom. Research indicates that this design enables teachers to acquire the ability to radiate several models in the classroom regardless of their “natural” styles. While personal values do not appear to affect acquisition of the repertoire of models, conceptual level is related to repertory acquisition. The teaching behavior of cooperating (supervising) teachers is not related to the behavior of teacher trainees when practicing the models of teaching but is related to their more general teaching styles.
Computationally efficient ASIC implementation of space-time block decoding

In this paper, we describe a computationally efficient ASIC design that leads to a highly efficient power and area implementation of space-time block decoder compared to a direct implementation of the original algorithm. Our study analyzes alternative methods of evaluating as well as implementing the previously reported maximum likelihood algorithms (Tarokh et al. 1998) for a more favorable hardware design. In our previous study (Cavus et al. 2001), after defining some intermediate variables at the algorithm level, highly computationally efficient decoding approaches, namely sign and double-sign methods, are developed and their effectiveness are illustrated for 2x2, 8x3 and 8x4 systems using BPSK, QPSK, 8-PSK, or 16-QAM modulation. In this work, alternative architectures for the decoder implementation are investigated and an implementation having a low computation approach is proposed. The applied techniques at the higher algorithm and architectural levels lead to a substantial simplification of the hardware architecture and significantly reduced power consumption. The proposed architecture is being fabricated in TSMC 0.18 μ process.
Inhibition of Ligand-independent ERK1/2 Activity in Kidney Proximal Tubular Cells Deprived of Soluble Survival Factors Up-regulates Akt and Prevents Apoptosis

Mouse kidney proximal tubular epithelial (MK-PT) cells die by apoptosis over 7–10 days when deprived of all survival factors. We show here that withdrawal of all survival factors from MK-PT cells is associated with a progressive increase in the activity of extracellular signal-regulated kinase-1 and -2 (ERK1/2) and a progressive decrease in phosphorylated Akt, a kinase critical to cell survival. Pharmacological inhibition of MEK1/2, the immediate upstream kinase for ERK1/2, not only prevented the decrease in phosphorylated Akt, but also prolonged MK-PT cell survival. Inhibition of ERK1/2, by itself, in the absence of any other known survival factors, was as potent as epidermal growth factor in maintaining MK-PT cell viability. ERK1/2 co-immunoprecipitated with Akt in a multimolecular assembly of signaling molecules, containing at a minimum ERK1/2, Akt, Rsk, and 3-phosphoinositide dependent kinase 1 (PDK1). We hypothesize that the kinase Rsk, whose activation requires phosphorylation by both ERK1/2 and PDK1, acts as a bridge bringing ERK1/2 into proximity with PDK1-associated Akt. Although a number of interactions between the Raf-MEK-ERK and PI3K-Akt signaling pathways have been described, our results are the first to show modulation of Akt activity by signaling events originating with ERK1/2. Spontaneous activation of ERK1/2 occurs via MEK1/2 and appears to depend on oxidant stress, accompanying induction of the default pathway of apoptosis. Together, these data suggest that the spontaneous activation of ERK1/2, in the absence of known extracellular stimuli, represents a previously unrecognized major regulatory pathway determining the fate of cells destined to die by the default pathway of apoptosis.
Characterization of Genetic Coding Changes in Bacteria Produced by Ionizing Radiation and by the Radioactive Decay of Incorporated 3H-labelled Compounds

SummaryThe mutagen specificity of ionizing radiation from 60Co γ-rays and radioactive decay was examined, using tritium-labelled nucleic acid and protein precursors (3H-methyl-thymidine; 3H-6-uracil and 3H-histidine). Specificity was determined through an examination of bacterial revertants, using a bacterium containing a nonsense mutation in a gene for arginine biosynthesis. By using nonsense mutants of T4 as indicators, arginine revertants may be divided into classes. The presumed amino-acid insertions for classes were assigned earlier. The base changes leading to the production of revertants in particular classes were derived from amino-acid insertions, using the genetic code and knowledge that nonsense suppressors arise by single base alterations in the DNA information specifying certain tRNA anticodons. The mutagenic agents studied were not specific; rather a broad spectrum of base changes was observed. For the tritium-labelled compounds used, percentage distributions of base changes are similar to t...
Gaining and losing market share and returns: a competitive dynamics model

In competitive environments, firms take strategic action in pursuit of superior returns or market power that will enhance returns. Drawing upon decades of competitive dynamics research, a model linking strategic action to shifts in market share and returns is presented. Research shows that firms take strategic action when aware of opportunities or threats, able to take action, and motivated to do so. Competitive actions that are not met with responses by rivals generate the most favorable consequences for actors. The greater the number of competitors' responses, and the more quickly they respond, the greater the attenuation of the initiators' gains from their action. Significant strategic actions that are difficult to implement and demonstrate strategic commitment on the part of the actor discourage response. Complex and unpredictable strategic actions promote market share gains, and the number of moves a firm makes is positively associated with profitability. Directions for future research are discussed.
Discreditable: Stigma Effects of Revealing a Mental Illness History on Test Performance

In three studies, the authors examined the effect of revealing a concealable social stigma—mental illness—on intellectual performance. It was hypothesized that revealing this deeply discrediting stigma would result in performance decrements. College students either with or without a history of mental illness (MI) treatment participated. In Study 1, the type of mental illness was left unselected. In Study 2, only participants who reported a history of depression participated. In Study 3, a comparison group of participants with a history of eating disorder were included. Results showed that the MI participants who revealed their history did worse on the reasoning test than did those in the no reveal condition. There was a trend in the opposite direction for participants with no MI. As predicted, revealing a narrower stigma, eating disorder, did not affect performance. The results are discussed in terms of identity threat and concealable stigmas.
Autoimmune Autonomic Ganglionopathy Associated with Voltage-Gated Potassium Channel Antibodies (P05.209)

Objective: To report a case of autoimmune autonomic ganglionopathy (AAG) associated with neuronal voltage-gated potassium channel (VGKC) antibodies. Background Ganglionic acetylcholine receptor (AChR) autoantibodies have been described in patients with idiopathic autonomic neuropathies, and with further characterization of the pathophysiologic role of these antibodies, the terminology of this condition has changed to AAG. The majority of patients fulfilling clinical and laboratory criteria for AAG are, however, seronegative and additional pathogenetic antibodies have been postulated. Recently, an association between N-type calcium channel antibodies and AAG has been described. Design/Methods: A 65 year-old woman with a one year history of orthostatic intolerance, heat intolerance, diarrhea, and sicca complex underwent comprehensive autonomic and laboratory evaluations and was diagnosed with AAG associated with VGKC antibodies. She underwent serial standardized autonomic, clinical, and laboratory evaluations for 2 years, before and during treatment with intravenous immunoglobulin (IVIG). Results: During her initial evaluation, the patient was found to have widespread anhidrosis with otherwise essentially normal autonomic function. A paraneoplastic antibody panel was positive for VGKC antibodies, which did not react to recently recognized specific VGKC-associated antigens (Lgi1, Caspr2). A search for an occult malignancy remained negative. During subsequent evaluations, progressive cardiovascular adrenergic impairment was documented with evidence of orthostatic hypotension, associated with a rise in the antibody titer. At that time, treatment with IVIG was initiated. Six months after initiation of IVIG, autonomic testing had essentially normalized, associated with a notable decrease in antibody titer. Conclusions: AAG may be associated with autoimmune antibodies other than the classic ganglionic ACHR and the recently reported calcium-channel antibodies. Whether the VGKC antibodies in our patient have a pathophysiologic role or are nonspecific indicators of an underlying immune process remains subject for further study. This association is, however, important to recognize regardless of the underlying mechanism, considering this patient9s remarkable response to immunomodulatory therapy. Supported by: R.F. Kinney Executive Dean for Research Career Development Award and NIH (BIRCWH 5K12HD065987-02 and NS44233). Disclosure: Dr. Singer has nothing to disclose. Dr. Klein has received personal compensation for activities with Pfizer Inc as a consultant. Dr. McKeon has nothing to disclose. Dr. Low has received personal compensation for activities with Chelsea, Pfizer, and WR Medical Inc. as a consultant.Dr. Low has received personal compensation in an editorial capacity for Autonomic Neuroscience.
Identification and Characterization of RRM-containing Coactivator Activator (CoAA) as TRBP-interacting Protein, and Its Splice Variant as a Coactivator Modulator (CoAM)

We previously cloned and characterized thyroid hormone receptor-binding protein (TRBP) as an LXXLL-containing general coactivator that associates with coactivator complexes through its C terminus. To identify protein cofactors for TRBP action, a Sos-Ras yeast two-hybrid cDNA library was screened using TRBP C terminus as bait. A novel coactivator was isolated, coactivator activator (CoAA), that specifically associates with TRBP. Human CoAA is composed of 669 amino acids with a TRBP-interacting domain and two highly conserved RNA recognition motifs (RRM) commonly found in ribonucleoproteins. A splice variant lacking the entire TRBP-interacting domain was also isolated as a coactivator modulator (CoAM), a 156-amino acid protein containing only the RRM region. Human CoAA and CoAM mRNAs are encoded by a single gene located on chromosome 11q13; alternative splicing in exon 2 of CoAA yields CoAM. CoAA interacts with both TRBP and p300 in vitro. In addition, CoAA potently coactivates transcription mediated by multiple hormone-response elements and acts synergistically with TRBP and CREB-binding protein (CBP). Furthermore, CoAA is associated with the DNA-dependent protein kinase-poly(ADP-ribose) polymerase complex. Strikingly, CoAM, which lacks a TRBP-interacting domain, strongly represses both TRBP and CBP action suggesting that CoAM may modulate endogenous CoAA function. These data suggest that CoAA may serve as a mediator of coactivators such as TRBP in gene activation.
Stimulating and recording from axons within their myelin sheaths: a stable and nondamaging method for studying single motor units

The contractile properties and activity patterns of single thyroarytenoid motor units were determined by stimulating and recording from their motoneuron axons within the recurrent laryngeal nerve. Most micropipette penetrations were within the myelin sheaths of axons but were functionally similar to actual axon impalements with respect to activation and recording of action potentials. Sheath penetrations were, however, less damaging to axons and were preferred for that reason. A myelin sheath approach combined the advantages of commonly used extra-axonal and intracellular methods for studying motor unit properties without their disadvantages. Specifically, the technique was stable, noninjurious in nature, and ensured stimulation and recording from the same motoneuron.
Eco-evolutionary dynamics of complex social strategies in microbial communities

Microbial communities abound with examples of complex social interactions that shape microbial ecosystems. One particularly striking example is microbial cooperation via the secretion of public goods. It has been suggested by theory, and recently demonstrated experimentally, that microbial population dynamics and the evolutionary dynamics of cooperative social genes take place with similar timescales, and are linked to each other via an eco-evolutionary feedback loop. We overview this recent evidence, and discuss the possibility that a third process may be also part of this loop: phenotypic dynamics. Complex social strategies may be implemented at the single-cell level by means of gene regulatory networks. Thus gene expression plasticity or stochastic gene expression, both of which may occur with a timescale of one to a few generations, can potentially lead to a three-way coupling between behavioral dynamics, population dynamics, and evolutionary dynamics
Detection of the imino hydrogen bond in GC pairs by 1H and 15N nuclear magnetic resonance spectroscopy

Abstract “Limiting” 1H and 15 N chemical shifts for the imino moiety of G in the G base pair were evaluated in model studies using chloroform soluble 2′,3′-O-iderivatives and were found to be significantly downfield from previously reported shifts measured in dimethylsulfoxide.
HORIZON I: Is there a future for oral anti-angiogenics on the horizon of colorectal cancer therapy?

In this issue of BJC, Cunningham et al (2013) report on a randomised phase II study of the VEGF receptor tyrosine kinase inhibitor cediranib (AZ 2171), given at 20 and 30 mg once daily compared with bevacizumab 10 mg kg−1 given with FOLFOX chemotherapy (Cunningham et al, 2013). The study was conducted as a second line trial, for patients with previously treated metastatic colorectal cancer. The study is noteworthy in directly comparing the novel anti-angiogenic to the antibody bevacizumab, rather than FOLFOX plus placebo, particularly in absence (at the time) of a randomised trial showing the benefit of second line bevacizumab or an FDA-approved indication in this setting. The study was part of a dose selection strategy for the HORIZON II and HORIZON III trials (Hoff et al, 2012; Schmoll et al, 2012), which resulted in the 20 mg cediranib dose selection for the large randomised trials.
Why illumination engineering

Illumination engineering is a nascent field in the broader category of optical engineering. The what, where, when, and who leads us to why illumination engineering is now a field in demand. This introductory talk to this year's Nonimaging Optics and Efficient Illumination Systems IV conference touches briefly upon the former queries. It ends with a discussion of the monetary dynamics, especially commercial products, electricity costs, and forecasts for the future.
Nanocrystalline Rare Earth Phosphates from Glass Dissolution and Precipitation Reactions

A novel method is employed for the formation of rare earth phosphate solid solution compounds with unique mesoscopic structures. Europium- and lanthanum-doped sodium borate glass microspheres and particles, ranging in sizes from 50 to 300 μm, were reacted in 0.25 M K2HPO4 solution to form hollow spheres of nanocrystalline rare earth phosphate compounds by dissolution–precipitation reactions. The initially X-ray amorphous precipitated rare earth phosphate materials were heat-treated at 700°C for 2 h to form nanocrystalline compounds. Differential thermal analysis (DTA) experiments yield an average activation energy for crystallization of 394 ± 26 kJ/mol. X-ray diffraction (XRD) data indicate that samples crystallized to the monazite structure (monoclinic P21/n) with unit cell volumes ranging from 306.5 A3 for LaPO4 to 282.5 A3 for EuPO4 and with crystallite grain sizes of 56 ± 14 nm. Compositions containing both rare earth elements formed solid solutions with the composition La(1−x)EuxPO4. Raman spectroscopy indicates that the P–O symmetric stretching vibrations (ν1) change systematically from 963 cm−1 for LaPO4 to 986 cm−1 for EuPO4, consistent with a systematic decrease in average P–O bond length. Photoluminescence measurements show maximum emission intensity for the La0.65Eu0.35PO4 composition.
The art of ALT: toward a more accessible Web

Abstract Continuing innovations in pedagogical uses of the Web are consistent with our discipline’s long-standing commitment to the expansion of literacy. Surging interest in multimedia and visual rhetoric emphasizes the importance of the 1999 Web Content Accessibility Guidelines as a tool for instructors seeking to make their Web documents accessible to learners and colleagues who have disabilities. Text-only variants of media-rich sites are not sufficient; on the Web, as on our campuses, separate is not and cannot be equal. Changes in the way we approach designing class Web sites may be necessary to enable all learners to participate equally in the learning community. Accessibility is not a property of the document: It is situated in specific contexts and distributed across multiple agents and artifacts. A Web experience designed to be rich and meaningful for people with disabilities is likely to be rich and meaningful for those without disabilities as well; however, the reverse is not necessarily true.
Equivalent mismatch negativity deficits across deviant types in early illness schizophrenia-spectrum patients.

Neurophysiological abnormalities in auditory deviance processing, as reflected by the mismatch negativity (MMN), have been observed across the course of schizophrenia. Studies in early schizophrenia patients have typically shown varying degrees of MMN amplitude reduction for different deviant types, suggesting that different auditory deviants are uniquely processed and may be differentially affected by duration of illness. To explore this further, we examined the MMN response to 4 auditory deviants (duration, frequency, duration + frequency “double deviant”, and intensity) in 24 schizophrenia-spectrum patients early in the illness (ESZ) and 21 healthy controls. ESZ showed significantly reduced MMN relative to healthy controls for all deviant types (p 0.05). These findings support the conclusion that neurophysiological mechanisms underlying processing of auditory deviants are compromised early in illness, and these deficiencies are not specific to the type of deviant presented.
Tolerance analysis of optical systems containing sampling devices

Numerous optical systems, such as telescopes, adaptive optics systems, and aberrometers, are equipped with wavefront sensors, which often use sampling devices measuring the slope of the wavefront at discrete points across the pupil (e.g. Shack-Hartmann sensors). The accuracy of the sampled output signal is always affected by the fabrication and alignment tolerances of the wavefront sensing optical system. Typically, it is a requirement to express the measurement error in terms of input wavefront, so the optical ray intercept error has to be converted into wavefront measurement error. This conversion cannot be obtained directly from a conventional tolerance analysis because of the wavefront breaking by the sampling device. The tolerancing method proposed in this paper solves the problem of converting conventional merit function degradation into input wavefront measurement error. The proposed method consists of two parts. First, a Monte Carlo tolerance analysis based on a specific merit function is performed, and a 90% border system is selected. Then, an optimization is applied to the 90% border system, by varying a "dummy" phase surface introduced at the entrance pupil of the system. A concrete example is presented.
A Critical Role for GluN2B-Containing NMDA Receptors in Cortical Development and Function

The subunit composition of N-methyl D-aspartate receptors (NMDARs) is tightly regulated during cortical development. NMDARs are initially dominated by GluN2B (NR2B), whereas GluN2A (NR2A) incorporation increases after birth. The function of GluN2B-containing NMDARs during development, however, is incompletely understood. We generated a mouse in which we genetically replaced GluN2B with GluN2A (2B→2A). Although this manipulation restored NMDAR-mediated currents at glutamatergic synapses, it did not rescue GluN2B loss of function. Protein translation-dependent homeostatic synaptic plasticity is occluded in the absence of GluN2B, and AMPA receptor contribution is enriched at excitatory cortical synapses. Our experiments indicate that specificity of GluN2B-mediated signaling is due to its unique interaction with the protein effector alpha calcium-calmodulin kinase II and the regulation of the mTOR pathway. Homozygous 2B→2A mice exhibited high rates of lethality, suppressed feeding, and depressed social exploratory behavior. These experiments indicate that GluN2B-containing NMDARs activate unique cellular processes that cannot be rescued by replacement with GluN2A.
Whey Permeate as a Medium for Mesophilic Lactic Acid Streptococci

Abstract Streptococcus lactis C 8 was inoculated into whey permeate, reconstituted skim milk permeate, two times (vol/vol) concentrated ultrafiltered whey, reconstituted skim milk, and reconstituted whey to compare growth and acid production. Permeate from reconstituted whey with .1% added yeast extract (BBL) was used as a growth medium for three different Streptococcus lactis ssp. diacetylactis strains and three Streptococcus cremoris strains. Acid development, generation time, and growth were determined for each culture in this medium during the 18-h incubation at 30°C. Streptococcus lactis C 8 and Streptococcus cremoris SK 11 were each propagated in permeate from reconstituted whey (3.5% total solids) and in RSM (9.0% total solids) over 7 d. Growth and acid production by the organisms in the two media were compared. All of the media in which S. lactis C 8 was grown supported growth of the culture. Variations in acid development were observed among the different types of media and appeared to be related to the levels of solids and growth factors present. Permeate from reconstituted whey with .1% yeast extract added supported varying degrees of growth and activity by the six mesophilic lactic streptococci cultures that were inoculated into this medium. The results of propagating S. cremoris SK 11 and S. lactis C 8 in permeate from reconstituted whey and in RSM showed that growth increases by each culture were similar in the two types of media. The pH remained higher in the permeate than in RSM. The results of this study indicate that whey permeate may be suitable as a growth medium for mesophilic lactic acid streptococci.
Allochthonous input of organic matter from different riparian habitats of an agriculturally impacted stream

Lapwai Creek, an agriculturally impacted stream in northern Idaho, was examined to determine longitudinal patterns of particulate allochthonous input from different riparian vegetation types. The stream, characterized by extensive removal of mature vegetation, was classified as having four riparian vegetation types: herbaceous, herbaceous-shrub mix, shrubs, and deciduous trees. Litterfall from each vegetation type was measured monthly for two years at eight locations along Lapwai Creek using 0.1-m2 baskets. Litterfall was lowest for herbaceous habitats and highest for deciduous tree habitats. Annual litterfall was low in the headwaters, which flow through an open meadow and deep canyon, and increased from the canyon-floodplain transition downstream to the first fifth-order site. Annual litterfall decreased markedly at the last two fifth-order stream sections. Differences in annual input rates between section 6 and sections 7 and 8, all of which are fifth order, can be attributed to removal of climax riparian vegetation. Estimates of actual and potential annual allochthonous income for each site suggest that current detrital inputs to Lapwai Creek are less than could be achieved if greater quantities of climax vegetation were still present. Lower rates of allochthonous inputs to Lapwai Creek may result in a system with detrital dynamics and macroinvertebrate communities different from that of comparable undisturbed streams of this region.
Intracellular Domains of CXCR3 That Mediate CXCL9, CXCL10, and CXCL11 Function

The chemokine receptor CXCR3 is a G protein-coupled receptor found predominantly on T cells that is activated by three ligands as follows: CXCL9 (Mig), CXCL10 (IP-10), and CXCL11 (I-TAC). Previously, we have found that of the three ligands, CXCL11 is the most potent inducer of CXCR3 internalization and is the physiologic inducer of CXCR3 internalization after T cell contact with activated endothelial cells. We have therefore hypothesized that these three ligands transduce different signals to CXCR3. In light of this hypothesis, we sought to determine whether regions of CXCR3 are differentially required for CXCL9, CXCL10, and CXCL11 function. Here we identified two distinct domains that contributed to CXCR3 internalization. The carboxyl-terminal domain and β-arrestin1 were predominantly required by CXCL9 and CXCL10, and the third intracellular loop was predominantly required by CXCL11. Chemotaxis and calcium mobilization induced by all three CXCR3 ligands were dependent on the CXCR3 carboxyl terminus and the DRY sequence in the third trans-membrane domain. Our findings demonstrate that distinct domains of CXCR3 mediate its functions and suggest that the differential requirement of these domains contributes to the complexity of the chemokine system.
ASSESSING THE AORTA WITH TRANSESOPHAGEAL ECHOCARDIOGRAPHY : UPDATE ON IMAGING CAPABILITIES WITH TODAY'S TECHNOLOGY

Improved ultrasound imaging with transesophageal echocardiography is now readily available, so prompt, portable, convenient, and safe assessment of aortic disease is possible. The procedure offers a diagnostic approach that may be more useful and less expensive than other imaging studies. Many experts recommend transesophageal echocardiography as the procedure of choice in patients with possible aortic dissection, especially those who are in clinically unstable condition. Most patients can successfully undergo transesophageal echocardiography. The procedure is also an excellent method for evaluating the success of surgical repair of aortic dissection, and it can be used in long-term patient follow-up. Transesophageal echocardiography can assess atherosclerotic lesion size and composition, the dynamic effect of flow, and the aortic intima and lumen in evaluation of aortogenic embolization. It may help identify patients at high risk of stroke during cardiac surgery. In addition, the procedure is sensitive and specific in diagnosing penetrating aortic ulcers, which occur when an atheromatous lesion pierces the internal elastica and extends into the aortic wall media. The process may cause formation of intramural hematoma, identified on transesophageal echocardiography as homogeneous mottled thickening of the aortic wall and inward displacement of intimal calcification.
Injection Drug Users in the Midwest: An Epidemiologic Comparison of Drug Use Patterns in Four Ohio Cities

Abstract Varialions in the drug use patterns of injection drug users (IDUs) can have important implications for public health efforts aimed at reducing drug abuse and the transmission of the human immunodeficiency virus. This article describes and compares the characteristics of IDUs living in four Ohio cities and compares African-American and While IDUs at a statewide level. Data from 2.001 IDUs who were recruited for the National AIDS Demonstration Research project between 1989 and 1991 in Columbus, Cleveland, Cincinnati, and Dayton were compared on a number of variables by city and by ethnicity using descriptive statistics and ANCOVA analysis. Significant differences among IDUs in the four cities exist for the use of alcohol, marijuana, cocaine, crack, heroin, speedball, other opioids, shooting gallery use, “safer” needle practices, treatment history, and self-help participation. Differences by ethuicity emerged on all variables except marijuana use, overall injection frequency, and incarceration exper...
Very intense laser-atom interaction through numerical investigations of a model: atomic stabilization

Proposals on detecting atomic stabilization have been suggested through possible generation of strong even-ordered harmonics or through blue shifted ATI peaks. The strength of observable signals has been the center issue of discussions. In this paper we remark on an alternative way in which stabilization process may be effectively detected. We show that in bichromatic fields the degree of ionization can be modulated by as much as 20% by changing the relative phase. In an experiment, by recording this phase modulation, one can calibrate and determine the degree of stabilization. In microwave ionization experiments reported, bichromatic field intensity has already been used as a sensitive probe in studying the so called quantum localization border.
Barth's myochordotonal organ as an acoustic sensor in the ghost crab, Ocypode

Nachweis des Barth'schen Myochordotonal-Organs bei der KrabbeOcypode, als sensorieller Apparat fur hochfrequente, akustische Signale.
Applications of Quadratic Programming

Abstract Quadratic programming (QP) has long been studied as an important O.R. technique. Many algorithms have been developed for solving QP problems. QP has also been very successful for modeling many real-life problems. This paper reviews application areas where QP has been effectively applied. Most applications of QP have been in finance, agriculture, economics, production operations, marketing, and public policy. Applications in each of these areas are briefly described.
Spectral properties and relaxation dynamics of surface plasmon electronic oscillations in gold and silver nanodots and nanorods

The field of nanoparticle research has drawn much attention in the past decade as a result of the search for new materials. Size confinement results in new electronic and optical properties, possibly suitable for many electronic and optoelectronic applications. A characteristic feature of noble metal nanoparticles is the strong color of their colloidal solutions, which is caused by the surface plasmon absorption. This article describes our studies of the properties of the surface plasmon absorption in metal nanoparticles that range in size between 10 and 100 nm. The effects of size, shape, and composition on the plasmon absorption maximum and its bandwidth are discussed. Furthermore, the optical response of the surface plasmon absorption due to excitation with femtosecond laser pulses allowed us to follow the electron dynamics (electron−electron and electron−phonon scattering) in these metal nanoparticles. It is found that the electron−phonon relaxation processes in nanoparticles, which are smaller than t...
Automated production of [11C]acetate and [11C]palmitate using a modified GE Tracerlab FXC-Pro

As researchers explore new applications for positron emission tomography radiopharmaceuticals, the demand for effective and readily available radiopharmaceuticals continues to increase. The syntheses of two such radiopharmaceuticals, [(11)C]acetate and [(11)C]palmitate, can be automated on the GE Tracerlab FX(C-Pro) by utilizing Grignard reactions. Radiochemical purities of the [(11)C]acetate and the [(11)C]palmitate products were high (>98% and >99.9%, respectively) with average non-corrected yields of 18% (n = 3) and 10% (n = 5), respectively. These data comprise the validation trials for site qualification of clinical production of both radiopharmaceuticals.
Studies relevant to catalytic reduction of dinitrogen to ammonia by molybdenum triamidoamine complexes

In this paper we explore several issues surrounding the catalytic reduction of dinitrogen by molybdenum compounds that contain the [(HIPTNCH2CH2)3N]3- ligand (where HIPT = 3,5-(2,4,6-i-Pr3C6H2)2C6H3). Four additional plausible intermediates in the catalytic dinitrogen reduction have now been crystallographically characterized; they are MoNNH (Mo = [(HIPTNCH2CH2)3N]Mo), [MoNNH2][BAr‘4] (Ar‘ = 3,5-(CF3)2C6H3), [MoNH][BAr‘4], and Mo(NH3). We also have crystallographically characterized a 2,6-lutidine complex, Mo(2,6-Lut)+, which is formed upon treatment of MoH with [2,6-LutH][B(C6F5)4]. We focus on the synthesis of compounds that have not yet been isolated, which include MoNNH2, MoNH, and Mo(NH2). MoNNH2, formed by reduction of [MoNNH2]+, has not been observed. It decomposes to give mixtures that contain two or more of the following: MoNNH, Mo⋮N, Mo(NH3)+, Mo(NH3), and ammonia. MoNH, which can be prepared by reduction of [MoNH]+, is stable for long periods in the presence of a small amount of CrCp*2, but in...
COUNTABLE-STATE-SPACE MARKOV CHAINS WITH TWO TIME SCALES AND APPLICATIONS TO QUEUEING SYSTEMS

Motivated by various applications in queueing systems, this work is devoted to continuous-time Markov chains with countable state spaces that involve both fast-time scale and slow-time scale with the aim of approximating the time-varying queueing systems by their quasistationary counterparts. Under smoothness conditions on the generators, asymptotic expansions of probability vectors and transition probability matrices are constructed. Uniform error bounds are obtained, and then sequences of occupation measures and their functionals are examined. Mean square error estimates of a sequence of occupation measures are obtained; a scaled sequence of functionals of occupation measures is shown to converge to a Gaussian process with zero mean. The representation of the variance of the limit process is also explicitly given. The results obtained are then applied to treat Mt /Mt /1 queues and Markov-modulated fluid buffer models.
Urinary levoglucosan as a biomarker of wood smoke exposure: observations in a mouse model and in children.

BackgroundBiomass smoke is an important source of particulate matter (PM), and much remains to be discovered with respect to the human health effects associated with this specific PM source. Exposu...
Gravity anomalies of the ridge-transform system in the South Atlantic between 31 and 34.5° S: Upwelling centers and variations in crustal thickness

To decipher the distribution of mass anomalies near the earth's surface and their relation to the major tectonic elements of a spreading plate boundary, we have analyzed shipboard gravity data in the vicinity of the southern Mid-Atlantic Ridge at 31–34.5° S. The area of study covers six ridge segments, two major transforms, the Cox and Meteor, and three small offsets or discordant zones. One of these small offsets is an elongate, deep basin at 33.5° S that strikes at about 45° to the adjoining ridge axes. By subtracting from the free-air anomaly the three-dimensional (3-D) effects of the seafloor topography and Moho relief, assuming constant densities of the crust and mantle and constant crustal thickness, we generate the mantle Bouguer anomaly. The mantle Bouguer anomaly is caused by variations in crustal thickness and the temperature and density structure of the mantle. By subtracting from the mantle Bouguer anomaly the effects of the density variations due to the 3-D thermal structure predicted by a simple model of passive flow in the mantle, we calculate the residual gravity anomalies. We interpret residual gravity anomalies in terms of anomalous crustal thickness variations and/or mantle thermal structures that are not considered in the forward model. As inferred from the residual map, the deep, major fracture zone valleys and the median, rift valleys are not isostatically compensated by thin crust. Thin crust may be associated with the broad, inactive segment of the Meteor fracture zone but is not clearly detected in the narrow, active transform zone. On the other hand, the presence of high residual anomalies along the relict trace of the oblique offset at 33.5° S suggests that thin crust may have been generated at an oblique spreading center which has experienced a restricted magma supply. The two smaller offsets at 31.3° S and 32.5° S also show residual anomalies suggesting thin crust but the anomalies are less pronounced than that at the 33.5° S oblique offset. There is a distinct, circular-shaped mantle Bouguer low centered on the shallowest portion of the ridge segment at about 33° S, which may represent upwelling in the form of a mantle plume beneath this ridge, or the progressive, along-axis crustal thinning caused by a centered, localized magma supply zone. Both mantle Bouguer and residual anomalies show a distinct, local low to the west of the ridge south of the 33.5° S oblique offset and relatively high values at and to the east of this ridge segment. We interpret this pattern as an indication that the upwelling center in the mantle for this ridge is off-axis to the west of the ridge.
The production spectrum of a relativistic Maxwell-Boltzmann gas

A formula is derived for use in the calculation of the spectrum of particles or photons produced through particle collisions in a Maxwell-Boltzmann gas. The result is valid for all temperatures and for the general case when the gas contains different mass particles. It is written in terms of a double integral over the cross section differential in the energy of the produced particles (or photons) in the center-of-momentum system of two colliding particles. Analytic expressions for the reaction rate and luminosity are also derived and reproduce the findings of previous work. Application to the problem of the annihilation spectrum from a relativistic Maxwell-Boltzmann electron-positron gas is made. Agreement is found between the present work and previous numerical and analytical studies.
Deuteron photodisintegration I. Theory and results at low energies

Abstract We extend the “elementary-particle treatment” of deuteron electrodisintegration at small excitation energies, as recently developed by Hwang, Henley, and Miller, by incorporating more (np)-scattering states so that deuteron disintegration by low-energy photons (e.g., ≤150 MeV) can also be investigated. As compared to the well-known formalism obtained by Partovi, the present theory has the following distinct features: The nucleon-only impulse approximation (NOIA), as modified to incorporate gauge invariance (GI), is assumed to be valid only in the Breit frame, in which the initial and final nuclear systems are treated symmetrically. The matrix element of the electromagnetic current is thus determined in the Breit frame and then transformed into the CM frame (i.e., the rest frame for the final n + p, or initial γ + D, system). In addition, the difference between the resultant NOIA GI and the NOIA is determined explicitly in every channel. Numerical results are obtained for the Reid soft-core potential with extensions required for J > 2 scattering states. Our major result is that there is no substantial discrepancy between the θp = 0° data of Hughes et al. and the prediction of this formalism. General features of this formalism, including angular distributions at low energies, are discussed in quantitative terms. Other important results at these energies include: (1) the 3FJ(np)-scattering states are found to be important for Eγ ≥ 20 MeV, especially at forward and backward angles (i.e., θp ∼ 0° or 180°); (2) the meson-exchange currents arising from intermediate isobar |Δ(1232)| propagation, with or without energy transfer effects, are not yet of any numerical significance; and (3) the results exhibit sensitivity to details of final-state interactions.
Interaction of lysine with pectin.

Abstract The interaction of l -lysine with citrus pectin was studied in a model system to determine under what conditions it would occur and whether it would be of physiological significance. Thirty-nine per cent of the lysine was non-diffusible at pH 7, when the pectin concentration was 0·5% and the lysine concentration was 2 × 10 −3 M . Of this, 29% was restricted due to the Donnan effect and the remainder was specifically bound. Increasing the pH (in the range 6–8) and the pectin concentration both increased the non-diffusible lysine. Increasing the ionic strength and the degree of esterification both decreased the non-diffusible lysine. It was concluded that lysine would not bind to pectin in the intestine because of the high salt concentration there.
Comparison of 2-chlorobenzoic acid biodegradation in a membrane bioreactor by B. cepacia and B. cepacia bearing the bacterial hemoglobin gene.

Abstract Degradation of 2-chlorobenzoic acid (2-CBA), a model recalcitrant chlorinated organic compound, by pure cultures of Burkholderia cepacia strain DNT with (transformed B. cepacia ) and without (untransformed B. cepacia ) the bacterial hemoglobin ( Vitreoscilla hemoglobin , VHb) gene, vgb , was investigated in parallel membrane bioreactors (MBRs). This was done aseptically to prevent contamination during the operation of the MBRs. The objective was to determine whether the degradation of 2-CBA by cometabolism, using acetate as a primary carbon source, under hypoxic conditions might be enhanced for vgb -bearing cells in MBRs. The 2-CBA removal efficiency of transformed B. cepacia (97–99%) was slightly higher than that of untransformed B. cepacia (95–99%) at all stages. The average amount of chloride released from 2-CBA by transformed cells was also higher than for untransformed cells, 92–96% compared to 64–84% of the maximum theoretical amount, the exact value depending on the operating conditions. These results indicate that 2-CBA degradation/transformation is not accompanied by the stoichiometric release of chloride for the untransformed strain. The difference between percentages of 2-CBA removal and chloride release by untransformed cells was attributed to persistence, under hypoxic conditions, of the 2-CBA chlorine atom in 2-CBA metabolites. Growth of transformed cells was also significantly enhanced under hypoxic conditions compared to untransformed cells. For varying media compositions, the transformed cells reached higher cell densities (3.2–5.4 g/L) relative to untransformed cells (2.8–4.7 g/L) at food to microorganism ratios ranging from 0.44–0.59 to 0.38–0.49 g COD/g biomass-d The observed yields thus ranged from 0.16–0.20 and 0.15–0.18 g TSS/g COD for untransformed and transformed cells, respectively. The value of the yield depended on medium composition. The MBR system using vgb -containing B. cepacia maintained a high biomass concentration without oxygen limitations and provided cell-free effluent. Hence, it may be useful for treating high volumes of water contaminated with low levels of recalcitrant organics.
Newly generated CD4 T cells in aged animals do not exhibit age-related defects in response to antigen

Using a T cell receptor transgenic (TCR Tg) mouse model, we have shown that TCR Tg CD4 cells from aged mice retain a naive phenotype, but exhibit reduced proliferation and IL-2 production in response to the antigen compared with cells from young mice. We hypothesize that age-related decreases in T cell function may be partly related to the age of the T cells. Because thymic output is decreased with age, peripheral T cells in older individuals are likely to be older than those in younger individuals. To investigate this possibility, we have manipulated the age of CD4 T cells in the periphery of young and aged mice. The production of new T cells was induced by depleting peripheral CD4 T cells or by creating bone marrow chimeras. In both young and aged individuals where we induced the production of new T cells, these newly generated cells exhibited robust responses to antigen ex vivo and in vivo, exhibiting good expansion, IL-2 production, and cognate helper function. Our results suggest that age-related defects in response to antigenic stimulation, in part, are caused by the age of the CD4 T cells.