cssi/SciSciGPT-SciSciNet huggingface dataset:
Preserving high multibunch luminosity in linear colliders

An analytic theory of cumulative multibunch beam breakup in linear colliders is developed. Included is a linear variation of transverse focusing across the bunch train as might be applied, e.g., by chirping the radio frequency power sources or by using radio frequency quadrupole magnets. The focusing variation saturates the exponential growth of the beam breakup and establishes an algebraic decay of the transverse bunch displacement versus bunch number. A closed-form expression for the transverse bunch displacement is developed. It is used to quantify the total normalized emittance and thereby isolate the region of parameter space corresponding to high multibunch luminosity. (c) 2000 The American Physical Society.
Tree trunks and branches as optimum mechanical supports of the crown: II. The branches

Using assumptions made in a previous paper, a theory of the shapes of primary branches is developed. Two cases are studied: a primary branch which has a portion denuded of secondary branches, and a primary branch with a continuous load of secondary branches. The first case leads to hyperelliptic integrals, the second—to polynomials of second degree.
Relationship between red blood cell uptake and methemoglobin production by nitrobenzene and dinitrobenzene in vitro.

Abstract Nitrobenzene increases methemoglobin formation when incubated with native hemoglobin but not when incubated with red blood cell suspensions. These experiments were designed to determine if transport of nitrobenzene across the red blood cell membrane is a limiting factor for methemoglobin production by red blood cell suspensions. Incubation of [14C]-m-o or p-dinitrobenzene, but not mononitrobenzene, with red blood cell suspensions caused a time-dependent increase in methemoglobin. All three dinitrobenzenes and mononitrobenzene crossed the red blood cell membrane and accumulated in the erythrocytes after only 1 min of incubation. Incubation of mononitrobenzene with hemolysates did not result in methemoglobin production. Incubation of red blood cells with the dinitrobenzene or mononitrobenzene for 1 and 10 min at 4°C did not influence red blood cell uptake of the nitrobenzenes, suggesting that these compounds do not enter the red blood cell by an active process. Dinitrobenzene-induced methemoglobin production was markedly inhibited at 4°C, and may be a result of decreased interaction with hemoglobin and/or decreased metabolism to reactive intermediates which mediate methemoglobin production. These data indicate that red blood cell transport of nitrobenzene is not the limiting factor in methemoglobin production in vitro .
CYP2E1 Sensitizes the Liver to LPS- and TNF α-Induced Toxicity via Elevated Oxidative and Nitrosative Stress and Activation of ASK-1 and JNK Mitogen-Activated Kinases

The mechanisms by which alcohol causes cell injury are not clear. A major mechanism is the role of lipid peroxidation and oxidative stress in alcohol toxicity. Many pathways have been suggested to play a role in how alcohol induces oxidative stress. Considerable attention has been given to alcohol elevated production of lipopolysaccharide (LPS) and TNFα and to alcohol induction of CYP2E1. These two pathways are not exclusive of each other; however, interactions between them, have not been extensively evaluated. Increased oxidative stress from induction of CYP2E1 sensitizes hepatocytes to LPS and TNFα toxicity and oxidants, activation of inducible nitric oxide synthase and p38 and JNK MAP kinases, and mitochondrial dysfunction are downstream mediators of this CYP2E1-LPS/TNFα-potentiated hepatotoxicity. This paper will summarize studies showing potentiated interactions between these two risk factors in promoting liver injury and the mechanisms involved including activation of the mitogen-activated kinase kinase kinase ASK-1. Decreasing either cytosolic or mitochondrial thioredoxin in HepG2 cells expressing CYP2E1 causes loss of cell viability and elevated oxidative stress via an ASK-1/JNK-dependent mechanism. We hypothesize that similar interactions occur as a result of ethanol induction of CYP2E1 and TNFα.
Xenbase: expansion and updates of the Xenopus model organism database

Xenbase (http://www.xenbase.org) is a model organism database that provides genomic, molecular, cellular and developmental biology content to biomedical researchers working with the frog, Xenopus and Xenopus data to workers using other model organisms. As an amphibian Xenopus serves as a useful evolutionary bridge between invertebrates and more complex vertebrates such as birds and mammals. Xenbase content is collated from a variety of external sources using automated and semi-automated pipelines then processed via a combination of automated and manual annotation. A link-matching system allows for the wide variety of synonyms used to describe biological data on unique features, such as a gene or an anatomical entity, to be used by the database in an equivalent manner. Recent updates to the database include the Xenopus laevis genome, a new Xenopus tropicalis genome build, epigenomic data, collections of RNA and protein sequences associated with genes, more powerful gene expression searches, a community and curated wiki, an extensive set of manually annotated gene expression patterns and a new database module that contains data on over 700 antibodies that are useful for exploring Xenopus cell and developmental biology.
Using the earth system for integrating the science curriculum

Content and process instruction from the earth sciences has gone unrepresented in the world's science curricula, especially at the secondary level. As a result there is a serious deficiency in public understanding of the planet on which we all live. This lack includes national and international leaders in politics, business, and science. The earth system science effort now engaging the research talent of the earth sciences provides a firm foundation from the sciences for inclusion of earth systems content into the evolving integrated science curricula of this country and others. Implementing integrated science curricula, especially at the secondary level where potential leaders often have their only exposure to science, can help to address these problems. The earth system provides a conceptual theme as opposed to a disciplinary theme for organizing such integrated curricula, absent from prior efforts. The end of the cold war era is resulting in a reexamination of science and the influence it has had on our planet and society. In the future, science and the curricula that teach about science must seriously address the environmental and social problems left in the wake of over 100 years of preparation for military and economic war. The earth systems education effort provides one such approach to the modernization of science curricula. Earth science educators should assume leadership in helping to establish such curricula in this country and around the world. © 1995 John Wiley & Sons. Inc.
Do Campaigns Help Voters Learn? A Cross-National Analysis

Recent empirical studies on American elections suggest that campaigns provide voters with the necessary information to make reasoned voting decisions. Specifically, campaigns help voters learn about the electoral relevance of ‘fundamental variables’, such as the economy and party stances, that have been consistently shown to predict electoral outcomes. Do these findings generalize beyond the American case? This article uses cross-national survey data in order to subject this thesis to a more comprehensive test. The analysis provides further support for the hypothesis that campaigns ‘enlighten’ voters as the election draws near. Moreover, the article shows that some voters learn more from campaigns than others. Campaign effects are more pronounced among individuals with low political sophistication and those living in party list systems. Implications for future research are explored, suggesting a ripe research agenda using under-tapped cross-national data.
Use of Stable Nitrogen Isotopes and Permeable Membrane Devices to Study what Factors Influence Freshwater Mollusk Survival in the Conasauaga River

Recent biological inventory data shows severe declines in freshwater mussel abundance and biodiversity in the Conasauga River Basin in Northwest Georgia, USA. Based on assessments of habitat conditions, mussel populations should be sustainable. We conducted a study of sediment and water quality to evaluate the impact of anthropogenic contamination on mussel populations. Permeable membrane devices (PMD), polar organic chemical integrative samplers (POCIS™), conventional water and sediment quality analyses, and stable nitrogen isotope ratio analyses (δ15N) of snails and sediments were used to assess sediment and water quality at target sites throughout the basin. Ambient concentrations of organic contaminants in water were well below any aquatic life criteria; concentrations of some nutrients were detected above aquatic life criteria levels. Most mussel species in the river are endangered or threatened; therefore, snails were collected for δ15N analyses. Mean δ15N values for snails collected at forested upper watershed sites (national forest areas) were significantly lower than δ15N values from snails in agricultural areas. δ15N values for raw cow manure and manure-treated soil were similar to δ15N values for snails collected in agricultural areas. Dissolved nitrate from water samples had elevated δ15N values similar to the upper range of δ15N values for snails in agricultural areas. Data, particularly stable nitrogen isotope data, indicates that a land use change from national forest land to agriculture alters nitrogen sources to the basin and snails. Implications of nutrient release on freshwater molluscan reproduction, growth, and survival are discussed.
Design, testing, and performance of the Hobby Eberly Telescope prime focus instrument package

The Hobby-Eberly Telescope (HET) is undergoing an upgrade to increase the field of view to 22 arc-minutes with the dark energy survey HETDEX the initial science goal [1]. Here we report on the engineering development of a suite of instruments located at prime focus of the upgraded HET. The Prime Focus Instrument Package (PFIP) contains acquisition, guiding, and wave front sensing instrumentation [2], the fiber feeds for the facility spectrographs (VIRUS, HRS, MRS, LRS2), and ancillary hardware. This paper reviews the design and functions of the PFIP and presents details of the mechanical design, integration and testing.
Marsupial light chains: IGK with four V families in the opossum Monodelphis domestica.

A full-length and several partial cDNAs encoding IGK light chains from the marsupial South American opossum, Monodelphis domestica, were isolated and characterized. Using these clones as a starting point, the expressed IGKV repertoire was sampled by anchored polymerase chain reaction using an IGKC-specific primer. Based on nucleotide sequences of twenty unique, expressed IGKV-J combinations, there are at least four IGKV families and two J segments. Southern blot analysis revealed each IGK-V family contains multiple gene segments totaling at least thirty-five IGKV in the opossum genome. No evidence for particular, recurrent IGKV-J combinations in the opossum IGK repertoire was seen, rather the V-J combinations appeared random and diverse. Each of the four IGKV families appear more closely related to V segments from placental mammals than to each other, suggesting the duplication of the IGKV families prior to the separation of marsupials and placental mammals more than one-hundred-million years ago. Overall, the complexity of opossum light chain V segments appears greater than that found in the heavy chain, and light chains are likely to contribute significantly to Ig diversity in this species.With this report, the homologues encoding all three classes of eutherian Ig chains, IGH, IGL, and IGK, have been described in a non-placental mammal.
A measurement based approach to fault tolerant control for TITO systems

In this paper, we propose a new fault-tolerant control design method for a given two-input two-output (TITO) system. Our approach does not require a mathematical model of the plant and is strictly based on measurement data. We employ the interval controller structure to design a set of multivariable controllers that provides the closed-loop system integrity. In other words, the closed-loop system maintains stability under all possible controller failures as long as at least one feedback loop is connected.
Alpha Magnetic Spectrometer on the International Space Station

The alpha magnetic spectrometer (AMS) will be attached to the International Space Station in the year 2000 for three years of operation. AMS will: (1) search for antinuclei in the cosmic rays; (2) measure the antiproton flux at the top of the earth's atmosphere; (3) measure the positron flux at the top of the earth's atmosphere; (4) measure high energy gamma rays from space; and (5) measure the isotopic composition of the light elements in the cosmic rays. In this paper we provide a general description of AMS, and a description of the antimatter, antiproton, and positron goals and performance capabilities of the instrument. The gamma ray detection capabilities are presented in another paper for this conference.
Deixis in memory for verb tense

Two experiments tested cued recall of sentences in either the present, past, future, present perfect, past perfect, or future perfect tenses. In Experiment I, 45% of the sentences were recalled with shifts in the verb tense, thus partially replicating the results of Clark and Stafford (1969) . However, the shifts appeared to be due to lack of temporal context (time deixis) rather than loss of marked semantic features. In Experiment II temporal adverbs were added to half of the sentences in order to provide a partial temporal framework. Tenseshifting was markedly reduced in sentences with temporal adverbs, thus supporting a memory-for-ideas theory with the specific condition that verb tenses are relatively meaningless without a temporal decitic context.
Colocutaneous gastric fistula: a complication of percutaneous endoscopic gastrostomy

Gastrocolic fistula is a rare complication of percutaneous endoscopic gastrostomy. It is most frequently discovered after replacement of the gastrostomy tube. The symptoms are severe diarrhea, failure to thrive, recurrent Gram-negative pulmonary infections, and feculent vomiting.
Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ∼12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (∼12,900 cal yr BP) was pine woodland (Pinus contorta) with alder (Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ∼12,240 cal yr BP, Sitka spruce (Picea sitchensis) began to colonize the island while pine woodland declined. By ∼11,200 cal yr BP, mountain hemlock (Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ∼10,180 cal yr BP, when western hemlock (Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ∼7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars (Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.
Portrayals of women in prime-time network television: Some demographic characteristics

This paper examines demographic variables to create a partial picture of current portrayals of women on network television. All prime-time programs for all networks served as the information base. The findings were that few changes had been made in the portrayals of women from the 1970s to the 1980s in terms of observable demographic characteristics.
Lupus Hepatitis: An Under-Recognized Disease Feature Associated With Autoantibodies to Ribosomal P

PURPOSE : To determine the frequency and clinical manifestations of systemic lupus erythematosus (SLE)-related liver disease and to establish whether this disease feature correlates with circulating autoantibodies to ribosomal P proteins. PATIENTS AND METHODS : A retrospective chart review of a large lupus cohort searching for laboratory and clinical manifestations of liver disease. A case-control study with testing of stored serum for antiribosomal P antibodies using immunoblotting, an enzyme-linked immunosorbent assay, and immunodiffusion in cases of lupus with liver involvement, and in randomly selected and ethnically-matched controls with lupus but without liver involvement. RESULTS : Of 131 patients with SLE, 4 (3%) had liver involvement that could only be ascribed to the disease itself, and 2 additional cases from elsewhere were also studied. The clinical picture of the liver involvement resembled chronic active hepatitis, but there was no serological evidence of hepatitis B or C infections. Only 1 patient had low-titer antismooth muscle antibodies, and none had antimitochondrial antibodies. Antiribosomal P antibodies were present in all 6 patients with lupus hepatitis, compared to only 2 (10%) of 20 of controls with lupus but no liver disease (P = 0.0001, odds ratio 96). CONCLUSIONS : Lupus hepatitis appears to be an infrequent but distinct manifestation of SLE which correlates strongly with the presence of antiribosomal P antibodies. Its course and prognosis are variable, ranging from chronic biochemical abnormalities of liver function to acute clinical hepatitis to hepatic failure.
Teaching Note---The MotoTech Manufacturing Company: Design of Experiments/ANOVA

Case Teaching Note: Interested Instructors please see the Instructor Materials page for access to the restricted materials. To maintain the integrity and usefulness of cases published in ITE, unapproved distribution of the case teaching notes and other restricted materials to any other party is prohibited.
Induction of sperm release in frogs by mammalian gonadotropin-releasing hormone

A single subcutaneous injection of a synthetic mammalian gonadotropin-releasing hormone (LH/FSH-RH) stimulated a rapid release of sperm (spermiation) from the testes of the intact treefrog Hyla regilla; the median effective dose was between 35 and 75 ng. The rate of response was dose-dependent, ranging from about 5 to 30 min. Even large injections of RH failed to stimulate spermiation in hypophysectomized frogs, but 100 ng RH was effective after transplantation of a pituitary into these animals. Thus, the action of RH is mediated by the frogs pituitary. These data confirm the lack of species-specificity in the hypothalamic gonadotropin-releasing factor.
Possibility of a high-power, high-gain FEL amplifier

Abstract High-gain FEL amplifiers offer many unique advantages such as robust operation without a high-Q optical cavity and potentially high extraction efficiencies with the use of tapered wigglers. Although a high average power, cw FEL amplifier has not been demonstrated, many key physics issues such as electron beam brightness requirements, single-pass gain, saturation, etc. have been resolved. In this paper, we study the feasibility of a high-power FEL based on the high-gain, tapered-wiggler amplifier. We show that with suitable electron beam parameters, a peak output power of 1 GW and a micropulse energy of 8 mJ can be achieved. We also outline a possible configuration of a high-power, high-gain FEL amplifier with energy recovery.
Carotid Endarterectomy: Emphasis on Necessity of Long-Term Postoperative Evaluation

Carotid endarterectomy remains an effec tive means of preventing a stroke in patients with extracranial carotid lesions. Although long-term patency may be assumed, the true incidence of recurrent pathology is not known. In the past, follow-up angiography has been performed only when recommended for recurrent symptoms and some postoper ative bruits. Four different pathologic condi tions found at the endarterectomized bifur cation site are discussed as are their treat ments.Long-term follow-up evaluation is strongly recommended. Angiography is in dicated for recurrent symptoms. Carotid bruits are difficult to evaluate on a yearly basis. Vascular laboratory studies are recom mended 4 months after surgery and then on a yearly basis. Hopefully, early and late res tenosis will be identified. An artery should be explored when symptoms and angiog raphic findings indicate recurrent pathology.
Protein micelles of human histocompatibility antigens (HLA-A and HLA-B).

Abstract Human histocompatibility antigens (HLA-A and -B) are membrane proteins which have large hydrophilic domains outside the cell membrane and a small hydrophobic portion in the lipid bilayer. In this paper we describe optimal conditions for preparing micelles of detergent-solubilized HLA-A2 and -B7 antigens. These homogeneous protein aggregates are water soluble and free of detergent and lipid. Hydrophobic interactions between the intramembraneous portions of the HLA antigens are the driving forces in the formation of these protein micelles. The papain-solubilized fragment of the HLA antigens is not included in the micelle. The average molecular weight of the HLA micelles is around 9 × 105 daltons, which suggests sixteen HLA-A2 and/or HLA-B7 antigenic molecules per protein aggregate. Electron microscopic studies revealed that the most frequent size of the micelles is 12 mm and that HLA-micelles are similar but not identical to micelles from Sindbis Virus glycoproteins (E1 and E2) The HLA-A2 and -B7 micelles retained full antigenic activity as judged by precipitations with allo- and heteroantisera. Such micelles will no doubt be important tools in further studies of the role of histocompatibility antigens.
Correlation between mammography and the pathology of nonpalpable breast lesions

One hundred consecutive needle localization biopsies were performed for nonpalpable breast lesions discovered on low-dose mammography of asymptomatic women between June, 1984, and August, 1986. Malignant disease was found on 21 biopsies. Four were carcinoma in situ, and 17 were infiltrating carcinomas. Only three of the infiltrating carcinomas had metastasized to regional nodes, as confirmed by subsequent axillary dissection. Two of these metastatic tumors involved two nodes and the third only one. The findings on the remaining 79 biopsies were benign. Forty-eight mammograms were read as "benign"; all (100%) were benign pathologically. Thirty-one mammograms were considered "malignant"; 19 (61%) were malignant pathologically. Only two of the 21 mammograms given "suspicious" interpretations were malignant. Microcalcifications correlated with malignancy only 30% of the time (12/42).
Real-time camera motion classification for content-based indexing and retrieval using templates

In this paper, a simple approach to camera motion analysis is proposed to index videos compressed using MPEG (Moving Picture Experts Group) −1, 2 in faster than real time. Specifically, this paper presents a template-matching algorithm to classify basic camera operations. The proposed approach involves 1) the construction of motion vector fields (MVFs) and filtering out noise; and 2) the sub-MVFs which come from dividing an MVF into several non-overlapping areas for the template matching of camera motions. A fine segmentation also can be obtained for a video, based on the homogeneity of the camera operation in each unit. The advantages of this method lie in real-time processing and robustness to noisy environments such as false motion vectors and object motions. The experimental results show that the proposed algorithm successfully classifies the camera movements.
SOLUTION OF CONTAMINANT TRANSPORT EQUATIONS USING AN ORTHOGONAL UPSTREAM WEIGHTING FINITE ELEMENT SCHEME.

An orthogonal upstream weighting finite element scheme is presented for approximating the contaminant transport equation, that will result in a matrix amenable to the pointwise solution strategies. Orthogonal upstream weighting functions are derived for line, quadrilateral, and triangular elements. Numerical experiments indicate that the direct elimination solutions of the proposed scheme yield comparable results as those obtained by the Galerkin and non-orthogonal upstream schemes. When the successive over-relaxation is applied to solving the matrix equation, the former generates convergent solutions for all cases. In contrast, the latter result in convergent solutions only for dispersion dominant transport, but produce divergent computations for advection dominant transport.
An improved protocol for the isolation and cultivation of embryonic mouse myocytes

In vitro cultures of cardiomyocytes have proven to be a useful tool for toxicological, pharmacological, and developmental studies, as well as for the study of the cellular and molecular mechanisms responsible for proper myocyte function. One deficient area of research is that of myocyte proliferation. Cardiomyocyte proliferation dramatically diminishes soon after birth and has a very limited occurrence within the adult heart, thus limiting the use of adult cells for proliferation studies. An improved understanding of the requirements for myocyte proliferation will allow for the development of better approaches to repair damaged heart tissue. Here, we provide a protocol for the reliable isolation of embryonic mouse myocytes. These myocytes behave similarly to those in vivo, including their ability to proliferate, providing an ideal system for the study of cardiomyocyte proliferation.
Mental health services in independent secondary boarding schools : The need for a model.

Independent secondary schools assume responsibility for the mental health needs of their boarding student populations generally with little guidance other than their own staff and anecdotal experiences. Given the prevalence of mental health problems affecting adolescents and the developmental challenges inherent to this population, inadequate services can pose serious adverse consequences. In an attempt to clarify early guidelines of a model of mental health for such schools, this study sought to qualitatively define the types of services available to students in these settings, and the factors which appear to influence adolescents access to mental health care. Through the use of an open-ended, 22-item, interview questionnaire, the authors interviewed the “director” of mental health services at 19 identified schools in a small sample of independent, secondary, college-preparatory, boarding schools in one northeastern state. Through the use of descriptive statistics, the authors found that tremendous diversity exists within this sample and offer some early guidelines of mental health services for such schools in the areas of administration, structure of services, confidentiality/repercussion issues, and systems issues. © 1999 John Wiley & Sons, Inc.
Status and "Defunct" Offices in Early Modern Korea: The Case of Five Guards Generals (Owijang), 1864–1910

Why the early modern Korean state continued to appoint Five Guards generals, and who they were are unanswered questions with important social implications. By examining law codes, personnel records, and profiles of the generals of the Five Guards which devolved from a large central army to a small security force, this study shows that the government used the appointment to recognize a good service by those without any realistic prospect of achieving important high offices monopolized by the capital aristocracy. The generals tended to be individuals neither aristocrat nor commoner in status, but some were elderly aristocrats of scholarly distinction. Although many appointees saw the post purely as an honor and resigned after a brief tenure, officeholders of a military background often performed patrol duties. The generalship was different than scores of devalued ranks and offices sold by the state. By the late nineteenth century, intermediate status groups had accrued economic and cultural capital to the extent that the state, which needed their service and cooperation, could not fool them with empty honors. All the same, the aristocratic proprietors of the state had to maintain some gradation of honors so that they could insure the integrity of existing social hierarchy.
NEW RELATIONSHIPS FOR TEMPERATURE SENSITIVITY OF RADIATION

In this work, the temperature sensitivity of radiation is extended to a certain wavelength interval and is also classified into two categories including the Temperature Sensitivity of Radiators (TSR) and the Temperature Sensitivity of Radiation Detectors (TSRD). Both the exact relationships and the approximated theories are presented. It is found that for a gray-body radiator with temperature-independent emissivity, the TSR is the same as TSRD for an ideal thermal radiation detector. However, there exists difference between an ideal quantum detector and an ideal thermal detector. This extension makes the defined quantity easier to be used in a lot of applications such as the design of industrial furnace and radiation detectors.
Time scales inferred from the cosmochronometers iodine-129, plutonium-244 and aluminum-26.

The r-process-like isotopic anomalies observed in Ba, Nd, and Sm from the Allende inclusions EK1-4-1 and Cl can be explained as due to an ‘early’ irradiation of the solar system material, which also produced radionuclides such as 26Al, 107Pd and 129I. The apparent conflict between the time scales inferred from the cosmochronometers 119I, 244Pu and 26Al reported by LEE et al. (1978) stems from the fact that these investigators have attempted to explain the isotopic anomalies in terms of a wholesale addition of the nucleosynthesis products from nearby stars to the solar nebula.
Lasing and quantum optics in nanostructured dielectrics

In recent years there has been a significant evolution in the development of high purity growth methods for nanoparticles in the 10 nm size range. Concurrently, new processing methods have led to the emergence of laser quality transparent ceramics prepared from rare-earth-doped nanopowders. Output powers and efficiencies of ceramic lasers have been reported to compare very well with those of crystal laser systems, causing interest both in nanoscale and macro-scale optical ceramics. In this paper, we first describe highly scattering oxide powders that generate continuous-wave random laser action, are able to store light, exhibit quantum size effects, and sinter to transparency at exceptionally low temperatures. Quantum size effects and modified dopant interactions in transparent ceramics processed from these powders are then considered, and their potential relevance to problems in laser cooling and the engineering of nanostructured ceramics for solid state lasers and nonlinear optics are evaluated.
Discovery of two new large submarine canyons in the Bering Sea

Abstract The Beringian continental margin is incised by some of the world's largest submarine canyons. Two newly discovered canyons, St. Matthew and Middle, are hereby added to the roster of Bering Sea canyons. Although these canyons are smaller and not cut back into the Bering shelf like the five very large canyons, they are nonetheless comparable in size to most of the canyons that have been cut into the U.S. eastern continental margin and much larger than the well-known southern California canyons. Both igneous and sedimentary rocks of Eocene to Pliocene age have been dredged from the walls of St. Matthew and Middle Canyons as well as from the walls of several of the other Beringian margin canyons, thus suggesting a late Tertiary to Quaternary genesis of the canyons. We speculate that the ancestral Yukon and possibly Anadyr Rivers were instrumental in initiating the canyon-cutting processes, but that, due to restrictions imposed by island and subsea bedrock barriers, cutting of the two newly discovered canyons may have begun later and been slower than for the other five canyons.
Faddeev-Popov procedure and Gribov copies

In simple examples, we find that gauges with Gribov copying are valid gauges. One need only compute the Faddeev-Popov determinant Δ exactly and procede. Δ provides the correct measure for the copies. A cut-off procedure keeping only the first copy is seen to work as well. In quantum chromodynamics, we point out a class of gauges, the field-strength gauges, for which Δ is easily computed.
Evaluation of 55Fe as a tracer of Fe(III) reduction in aquatic sediments

Abstract The potential utility of 55Fe as a tracer for Fe(III) reduction in aquatic sediments was evaluated using freshwater sediments from the Potomac River, Md, in which Fe(III) reduction was the predominant terminal electron accepting process. In laboratory incubations of sediments amended with poorly crystalline 55Fe(III) oxide, the accumulation of 55Fe in Fe(II) over time paralleled Fe(II) production. However, within 1 h of addition of 55Fe(III) oxide, significant quantities of 55Fe were recovered in extractable (1 M sodium acetate, pH 5) and soluble Fe(II) pools. There was proportionately more 55Fe(II) activity in sediments with higher Fe(II) concentrations. These results suggest that there was rapid isotopic exchange between 55Fe in poorly crystalline Fe(III) oxide and the Fe(II) pools. Because of this exchange, 55Fe could not be used to trace Fe(III) reduction in sediments in the manner that 35SO4 2− is used to trace sulfate reduction. Although accumulation of 55Fe in Fe(II) pools paralleled unla‐...
Layer-by-layer growth of cuprate thin films by pulsed laser deposition

Abstract The pulsed laser deposition technique has been used to deposit, in a layer-by-layer growth mode, superconducting cuprate thin films on (100) SrTiO 3 substrates. The films are deposited using a combination of pulsed O 2 jet and a continuous source of atomic O, with the average background pressure maintained as low as 1 mTorr. This permits the in-situ monitoring of the growth process using reflection high-energy electron diffraction (RHEED). Before growth of the cuprate films, a thin SrTiO 3 buffer layer is homoepitaxially deposited on the substrate to provide an atomically smooth surface. On a smooth surface, the growth of SrTiO 3 occurs in a layer-by-layer mode as indicated by the intensity oscillations of the specular spot in the RHEED pattern. Subsequent layer-by-layer growth of a variety of cuprate films, including YBa 2 Cu 3 O 7− δ (YBCO), La 1.85 Sr 0.15 CuO 4 (LSCO), Nd 1.85 Ce 0.15 CuO 4 (NCCO), and SrCuO 2 (SCO), has been achieved under appropriate deposition conditions.
Isolation and Structure of Leukotriene-A4 Hydrolase Inhibitor: 8(S)-Amino-2(R)-methyl-7-oxononanoic Acid Produced by Streptomyces diastaticus

The novel amino acid 8(S)-amino-2(R)-methyl-7-oxononanoic acid (1) was isolated from the soil-borne microorganism Streptomyces diastaticus during our screening for inhibitors of leukotriene-A4 hydrolase (LTA4H), a requisite enzyme in the biosynthesis of the potent inflammatory mediator leukotriene-B4 (LTB4). The structure of 1 was determined by detailed spectroscopic analyses and is related to 7-keto-8-aminopelargonic acid (2), a biosynthetic precursor of biotin. The relative potency of 1 (LTA4H IC50 = 0.6 microM) warranted further biological studies.
A stable and convergent three-level finite difference scheme for solving a dual-phase-lagging heat transport equation in spherical coordinates

Heat transport at the microscale is of vital importance in microtechnology applications. The heat transport equation is different from the traditional heat diffusion equation since a second-order derivative of temperature with respect to time and a third-order mixed derivative of temperature with respect to space and time are introduced. In this study, we consider the heat transport equation in spherical coordinates and develop a three level finite difference scheme for solving the heat transport equation in a microsphere. It is shown that the scheme is unconditionally stable and convergent. The method is illustrated by two numerical examples.
Hypoxia increases Hsp90 binding to eNOS via PI3K-Akt in porcine coronary artery endothelium

This study examines the molecular mechanisms by which hypoxia regulates phosphorylated endothelial nitric oxide synthase (eNOS) activity and NO production in porcine coronary artery endothelial cells (PCAEC). Exposure to hypoxia (pO(2)=10 mmHg) for periods up to 3 h resulted in a time-dependent increase in eNOS protein expression and an early (15 min) and sustained increase in eNOS phosphorylation at Ser-1177. Exposure to hypoxia for 30 min led to a doubling in eNOS activity (control=6.2+/-4.4 vs hypoxia=14.1+/-5.0 fmol cGMP/microg protein, P<0.05) and NO release (control=5.9+/-0.8 vs hypoxia=11.8+/-1.2 nM/microg protein, P<0.05). Hypoxia also led to a significant increase in Akt phosphorylation and upregulation of Hsp90 binding to eNOS. Pretreatment of cells with either 1 microg/ml geldanamycin (a specific inhibitor of Hsp90) or 500 nM wortmannin (a specific PI3 kinase inhibitor) suppressed hypoxia-stimulated Akt and eNOS phosphorylation and significantly attenuated hypoxia-stimulated Hsp90 binding to eNOS. Both eNOS activity and NO production were inhibited by geldanamycin and wortmannin. Although hypoxia led to early activation of p42/44 mitogen-activated protein kinases (MAPK), inhibition of their pathway by PD98059 did not suppress hypoxia-stimulated eNOS phosphorylation and eNOS activity. These data demonstrate that hypoxia leads to increased eNOS phosphorylation via stimulated Hsp90 binding to eNOS and activation of the PI3-Akt pathway. We conclude that a coordinated interaction between Hsp90 and PI3-Akt may be an important mechanism by which eNOS activity and NO production is upregulated in hypoxic heart.
Chemical investigations of the giant nerve fibers of the squid. V. Quaternary ammonium ions in axoplasm.

Abstract Quaternary ammonium bases were isolated from nerve axoplasm of the squid Dosidicus gigas , and partial identification was achieved. One of the bases appears to be tetramethylammonium ion (“tetramine”), and reasons are given to believe that another base is a quaternary pyridinium compound. closely related to N-methylpyridinium ion. Though the nature of the two other constituents is still unknown, it can be said that probably neither one of them has a free carboxyl group. The total concentration of these basic constituents of axoplasm is about 0.1% of the dialyzable solutes.
Crowding and Human Behavior: A Guide for Urban Planners:

Research concerned with the effects of population density on humans is inconsistent in demonstrating aversive effects of high density. The concept of ‘crowding’ is discussed in an attempt to develo...
Loperamide dependence and abuse

Loperamide is a common over-the-counter antidiarrheal considered safe in a broad range of dosages and thought devoid of abuse potential. We describe the first case of a patient with loperamide dependence due to misuse of its opiate-like effects achieved by chronic massive oral ingestions. A 26-year-old man who was taking 800 mg of loperamide per day presented requesting detoxification referral. Loperamide has potential for euphoric effects and information on how to facilitate such effects is easily available. It is important for physicians to be aware of the potential for misuse of and dependence on loperamide, with symptoms mimicking opiate use.
World-Wide Correlation of Mesozoic Magnetic Anomalies, and Its Implications

In the course of correlating three sets of Mesozoic magnetic lineations in the western Pacific (the Phoenix, Japanese, and Hawaiian lineations), Larson and Chase (1972) determined a paleomagnetic pole for the Pacific plate for the Early Cretaceous. Using this pole we have derived a magnetic reversal model for the Hawaiian lineation set. We then have used this model to correlate the entire Hawaiian lineation set to the entire Keathley lineation set in the western North Atlantic. On the basis of these correlations and drill holes associated with the lineation patterns, we have extended the geomagnetic reversal time scale back to the base of the Late Jurassic (162 m.y. B.P.). A period of reversals occurred corresponding to the Hawaiian and Keathley lineations from 150 o t 110 m.y. B.P., and these reversals are bracketed by long periods of dominantly normal polarity (the Cretaceous and Jurassic magnetic quiet zones). This magnetic reversal time scale significantly alters previous notions of the timing and origin of sea-floor spreading features in the Atlantic Ocean. It implies that the Bay of Biscay opened sometime during the interval between 150 and 110 m.y. B.P.; that drift in the South Atlantic was initiated at sometime during the interval from 110 to 85 m.y. B.P. (probably close to 110 m.y. B.P.); and that the seaward portion of the marginal quiet zones of the eastern United States and northwestern Africa resulted from sea-floor spreading during the Late Jurassic period of dominantly normal magnetic polarity prior to 150 m.y. B.P. In the Pacific during the late Mesozoic, spreading was occurring from at least five spreading centers joined at two triple points. The vast majority of the Pacific Basin today is occupied by only the Pacific-plate side of these spreading patterns. This implies that an area equal to most of the Pacific Basin has been subducted beneath the surrounding continents since the Early Cretaceous. Our magnetic reversal time scale calls for a rapid pulse of spreading from about 110 to 85 m.y. B.P. at all the spreading centers in both the Atlantic and Pacific Oceans. This implies a pulse of rapid subduction around the rim of the Pacific that we relate to episodes of large-scale plutonism in eastern Asia, western Antarctica, New Zealand, the southern Andes, and western North America during the Late Cretaceous.
Where's the example?

Lewis has missed an excellent opportunity to concisely demonstrate what that a dynamical system can provide a bridge between emotion theory and neurobiology.
Is there really a Lutz—Kelker bias? Reconsidering calibration with trigonometric parallaxes

In the recent literature there are indications of some confusion regarding the Lutz–Kelker bias: whether or not it exists, and if so, what it is and when it should be corrected. Here we carefully reexamine Lutz & Kelker's original work to understand what they actually did, and then look at their later papers and some other works on the subject. There is, properly speaking, no universal Lutz–Kelker bias of individual parallaxes. There is a bias for stars that are members of samples which is different from, but often has the same form as and is given the name of, the Lutz–Kelker bias. The overall bias for samples selected according to relative parallax error is sometimes given the name of Lutz–Kelker; in fact it is, or is very nearly the same as, that discussed by Trumpler and Weaver. The Lutz–Kelker corrections can, under certain conditions, be used to counter that bias. The Lutz–Kelker correction applied for an isolated star (independent of sample properties) is an incomplete refinement of the estimate of absolute magnitude calculated directly from the parallax, not a correction for bias. We reconsider the more general problem of calibration using only trigonometric parallaxes, and examine some of the maximum likelihood methods proposed for its solution. Of these, several are based on linear approximation and are therefore of limited validity. Three exact methods are all based on essentially the same form of the likelihood but are implemented in different ways. One of these is statistically flawed, as was originally pointed out by Jung. We test the other two using synthetic samples, compare their performance, and discuss their application. We also apply one (grid method) to the Feast–Catchpole high weight sample of Hipparcos Cepheid parallaxes as a test. The grid method is to be preferred over the approximate ones because it does not have a limited range of validity, should not require any a posteriori correction, and provides a more complete picture of the uncertainties, in the form of a contour diagram of log(likelihood).
A structural linkage between the dimerization and encapsidation signals in HIV-2 leader RNA.

The 5 untranslated leader region of retroviral RNAs contains noncoding information that is essential for viral replication, including signals for transcriptional transactivation, splicing, primer binding for reverse transcription, dimerization of the genomic RNA, and encapsidation of the viral RNA into virions. These RNA motifs have considerable structural and functional overlap. In this study, we investigate the conformational dynamics associated with the use and silencing of a sequence in HIV-2 RNA that is involved in genomic RNA dimerization called stem–loop 1 (SL1) and its relationship with a flanking sequence that is known to be important for encapsidation of viral RNAs. We demonstrate that a long-distance intramolecular interaction between nucleotides located upstream of the primer-binding site domain and nucleotides encompassing the Gag translation start codon functionally silences SL1 as a dimerization element. This silencing can be relieved by mutation or by hybridization of an oligonucleotide that disrupts the long-distance interaction. Furthermore, we identify a palindrome within the packaging/ encapsidation signal (just 5 of SL1) that can either serve as an efficient dimerization signal itself, or can mediate SL1 silencing through base pairing with SL1. These results provide a tangible link between the functions of genomic RNA dimerization and encapsidation, which are known to be related, but whose physical relationship has been unclear. A model is proposed that accounts for observations of dimerization, packaging, and translation of viral RNAs during different phases of the viral replication cycle.
Risk‐taking and sensation‐seeking propensity in postinstitutionalized early adolescents

BACKGROUND: Youth with histories of institutional/orphanage care are at increased risk for externalizing and internalizing problems during childhood and adolescence. Although these problems have been well described, the related adolescent behaviors of risk-taking and sensation-seeking have not yet been explored in this population. This study examined risk-taking and sensation-seeking propensity, and associations with conduct problems and depressive symptoms, in early adolescents who were adopted as young children from institutional care. METHODS: Risk-taking and sensation-seeking propensities of 12- and 13-year-old postinstitutionalized (PI; n = 54) adolescents were compared with two groups: youth who were internationally adopted early from foster care (PFC; n = 44) and nonadopted youth (NA; n = 58). Participants were recruited to equally represent pre/early- and mid/late-pubertal stages within each group. Participants completed the youth version of the Balloon Analogue Risk Task (Lejuez et al., ) and the Sensation-Seeking Scale for Children (Russo et al., ). Parents completed clinical ratings of participants' conduct problems and depressive symptoms. RESULTS: PI adolescents demonstrated lower risk-taking than PFC and NA peers. Pre/early-pubertal PI youth showed lower sensation-seeking, while mid/late-pubertal PI youth did not differ from other groups. PI adolescents had higher levels of conduct problems but did not differ from the other youth in depressive symptoms. In PI youth only, conduct problems were negatively correlated with risk-taking and positively correlated with sensation-seeking, while depressive symptoms were negatively correlated with both risk-taking and sensation-seeking. CONCLUSIONS: Early institutional care is associated with less risk-taking and sensation-seeking during adolescence. The deprived environment of an institution likely contributes to PI youth having a preference for safe choices, which may only be partially reversed with puberty. Whether this reflects hyporesponsiveness to rewards and how it relates to psychopathology are discussed. Language: en