cssi/SciSciGPT-SciSciNet huggingface dataset:
Long-term storage of tissues by cryopreservation: critical issues

The technique of cryopreservation (maintenance of biological samples in a state of 'suspended animation' at cryogenic temperatures), its potential use in tissue engineering applications and current obstacles to the development of effective cryopreservation methods for tissues are reviewed. A didactic overview of the principles of cryobiology and the methodology of cryopreservation is given, with emphasis on the processes of injury to cells during freezing and thawing, and how these are related to the physicochemical and biophysical changes occurring during cryopreservation. Critical issues relevant to the application of cryopreservation methods to tissues are then addressed, including heat and mass transfer limitations in these bulk systems, intrinsic differences between isolated and cultured cells, and mechanisms of freezing injury unique to tissue systems.
Gastric Rupture with Pneumoperitoneum after Mouth-To-Nose Breathing in an Infant

Background: Gastric rupture with resulting tension pneumoperitoneum occurs rarely in infants. It may be associated with resuscitative efforts. Objectives: This report presents a unique case of gastric rupture and illustrates the factors necessary for prompt recognition and treatment. Case Report: The patient was a 16-week-old infant with nasal congestion whose father had attempted to clear her nose by a mouth-to-mouth-and-nose maneuver. The alert and attentive patient presented to the Emergency Department in respiratory distress, with marked abdominal distention. She was diagnosed with a massive tension pneumoperitoneum, which was decompressed by needle aspiration. A laceration of the lesser curvature of the stomach was repaired at laparotomy; the patient recovered uneventfully. Conclusion: Tension pneumoperitoneum is rarely seen but has key defining elements. A simple procedure is critical to relief of the condition.
Defining emotional disturbance public policy and research

The legal definition of “emotional disturbance” proposed by the Federal Government under PL 94–142 is Bower's 1957 definition with some modifications. The modifications do serious damage to the integrity of the research and conceptual base from which the definition is drawn. The difficulties inherent in a definition of this type of handicapped are delineated. It is suggested that where policy makers and researchers join together, such relationships are best enhanced when each respects the assumptions and concepts of the other.
Arctic Warming Ripples through Eurasia

Arctic warming provides an excellent demonstration of the teleconnections within and between the natural and societal systems at global, regional, and local scales. This paper examines climatic and related environmental changes occurring in the Arctic and discusses how the changes may cascade throughout the world, with particularly pronounced effects in parts of Eurasia. The paper outlines numerous manifestations of a warming Arctic climate, including reduced Arctic ice cap thickness and extent, reduction of the continuous permafrost zone, and changes in the conditions of terrestrial and marine habitats in the Far North. It explores how these changes have already affected human activities in the area, creating both potential opportunities and problems in Arctic marine transportation, access to renewable and non-renewable resources, economic development, national security, and safety. Another focus of the paper is on how changes in the Arctic are likely to affect Eurasia, as well as other parts of the worl...
Analysis of the X-Ray Imaged Solid Oxide Fuel Cell Anode Microstructure

Solid oxide fuel cell (SOFC) anodes are comprised of heterogeneous functional materials that include a pore phase which supports gas transport and solid phases which support ionic and electronic charge transport. A more detailed understanding of the contributions each of these phases makes to overall anode performance is critical for the design and development of next generation SOFCs. In the present work, three dimensional tomographic reconstructions of SOFC anodes are addressed with consideration given to the characterization of distinct pore, ionic and electronic conducting phases. These reconstructions are produced from transmission x-ray microscope (TXM) images taken at 38 nm spatial resolutions. Elemental mapping enabled by the TXM is used to determine the distribution of pore and solid ionic and electronic conducting phases within the anode. The results presented provide key insights into the composition and morphology of SOFC microstructures. The application of x-ray computed tomography (XCT) to ex situ SOFC micrsostructural characterization is demonstrated, and further applications of this technique are discussed.Copyright © 2010 by ASME
Half-integer flux quantum effect in cuprate superconductors – a probe of pairing symmetry

Based on macroscopic quantum coherence effects arising from pair tunneling and flux quantization, a series of tricrystal experiments have been designed and carried out to test the order parameter symmetry in high-Tc cuprate superconductors. By using a scanning SQUID microscope, we have directly and non-invasively observed the spontaneously generated half-integer flux quantum effect in controlled-orientation tricrystal cuprate superconducting systems. The presence or absence of the half-integer flux quantum effect as a function of the tricrystal geometry allows us to prove that the order parameter symmetry in the YBCO and Tl2201 systems is consistent with that of the dx2−y2 pair state.
Detection of High-Frequency Oscillations by Hybrid Depth Electrodes in Standard Clinical Intracranial EEG Recordings

High-frequency oscillations (HFOs) have been proposed as a novel marker for epileptogenic tissue, spurring tremendous research interest into the characterization of these transient events. A wealth of continuously recorded intracranial electroencephalographic (iEEG) data is currently available from patients undergoing invasive monitoring for the surgical treatment of epilepsy. In contrast to data recorded on research-customized recording systems, data from clinical acquisition systems remain an underutilized resource for HFO detection in most centers. The effective and reliable use of this clinically obtained data would be an important advance in the ongoing study of HFOs and their relationship to ictogenesis. The diagnostic utility of HFOs ultimately will be limited by the ability of clinicians to detect these brief, sporadic, and low amplitude events in an electrically noisy clinical environment. Indeed, one of the most significant factors limiting the use of such clinical recordings for research purposes is their low signal to noise ratio, especially in the higher frequency bands. In order to investigate the presence of HFOs in clinical data, we first obtained continuous intracranial recordings in a typical clinical environment using a commercially available, commonly utilized data acquisition system and "off the shelf" hybrid macro-/micro-depth electrodes. These data were then inspected for the presence of HFOs using semi-automated methods and expert manual review. With targeted removal of noise frequency content, HFOs were detected on both macro- and micro-contacts, and preferentially localized to seizure onset zones. HFOs detected by the offline, semi-automated method were also validated in the clinical viewer, demonstrating that (1) this clinical system allows for the visualization of HFOs and (2) with effective signal processing, clinical recordings can yield valuable information for offline analysis.
Tolerance of imperfections in high-energy circular accelerators for polarized protons.

Realistic calculations show that imperfection-spin-resonance strengths {epsilon}{sub imp} can be corrected to {epsilon}{sub imp}{lt}1, at 20 TeV, Superconducting Super Collider (SSC) energy. Statistical analysis agrees well with the numerical calculation. The polarized proton must be accelerated through overlapping intrinsic and imperfection resonances. We found a correlation between the tolerable strengths of intrinsic and imperfection resonances {epsilon}{sub int} and {epsilon}{sub imp}, that is, at smaller {epsilon}{sub int}, the tolerable {epsilon}{sub imp} becomes larger, and vice versa. To obtain a larger tolerable {epsilon}{sub imp}, we suggest that the number of snakes should be chosen according to {ital N}{sub {ital S}}{ge}5{epsilon}{sub int}. When a large number of snakes is used in the accelerator, the tolerable deviation of the spin rotational angle from 180{degree} for each snake becomes more stringent. The error in the spin rotation angle gives rise to (1) an equivalent picket-fence imperfection resonance {epsilon}{sub imp}{sup eq} and (2) an energy-dependent spin tune {nu}{sub {ital s}}. Both of these effects may cause depolarization. Further, when the snake axis is not properly arranged, the spin tune deviates from half-integer. In this case, depolarization may arise from the snake resonances. Our analysis indicates that acceleration of polarized protons in the SSC is technically feasiblemore » if care is taken in constructing the snakes.« less
Collagenous Sprue, an Enigma in the Spectrum of Celiac Disease

A64-year-old white woman presented to our clinic with bilateral swelling of her hands and feet and an unintentional 50-pound weight loss over the past year. She was having 1 to 2 bowel movements daily with occasional additional watery stools without dietary variation. Laboratory values were as follows: alanine aminotransferase, 35 IU/L; aspartate aminotransferase, 46 IU/ L; alkaline phosphatase, 117 IU/L; total bilirubin, 0.3 mg/dL; albumin, 1.7 g/dL; and hemoglobin, 11.6 g/ dL. Her liver function tests later normalized after discontinuing her statin and meloxicam, but given her weight loss she was evaluated endoscopically. Esophagogastroduodenoscopy showed moderately erythematous mucosa of the entire stomach and blunted duodenal mucosa (Figure A). Her colonoscopy was normal. A biopsy showed almost complete flattening of the duodenal mucosa and subepithelial collagen deposition in the absence of intraepithelial lymphocytosis (Figure B). Collagen was highlighted with a trichrome stain (Figure C). Subepithelial collagen deposition also was seen in the cecum and in the left and right colon (Figure D). Antral and fundic biopsy specimens showed chronic gastritis. Celiac panel and later HLA-DQ2/DQ8 were negative. She was started on 9-mg oral budesonide capsules and initially a gluten-free diet for collagenous sprue. After 16 weeks of treatment she gained 24 pounds, her albumin level increased to 3.3 g/dL, and her edema resolved. She was started on an 8-week budesonide taper and a regular diet without return of symptoms. Collagenous sprue (CS) is a rare cause of severe malabsorption. We present a case of collagenous sprue with concomitant collagenous colitis. Most cases of CS are reported in middle-aged to elderly Caucasian women. CS clinically presents similarly to celiac disease—with chronic diarrhea and weight loss. Our patient had an atypical presentation given her lack of diarrhea. Histopathologically, CS is distinguished by the presence of significant subepithelial collagen deposition entrapping blood vessels and inflammatory cells in addition to distorted villous and crypt architecture in the small bowel. There is ongoing debate regarding whether CS is a separate disease entity or simply part of the celiac spectrum. Some experts believe CS to be a histopathologic variant of celiac disease with a poorer outcome. Biopsy-proven celiac disease and CS both can have concomitant collagenous or lymphocytic gastritis and/or colitis. The prevalence of specific HLA haplotypes has not yet been proven in CS. Corticosteroids have been used increasingly to treat CS. The capsule formulation of oral budesonide has at least equal therapeutic efficacy compared with other steroids, with less first-pass hepatic metabolism, showing benefit with enhanced local colonic absorption; and this formulation has been used successfully to treat refractory sprue as well. Response to dietary gluten removal has been shown to be inconsistent, particularly in HLA-DQ2/DQ8–negative patients. Collagenous sprue is a rare cause of severe malabsorption that may be part of the celiac spectrum. It can
Circulant matrices and differential-delay equations

On etudie les solutions periodiques non triviales de familles parametrisees d'equations differentielles a retard
Two improvements on the Clinton framework.

I t is wonderful that the Clinton administration has created the possibility of major reform of health insurance and medical care. While the Clinton proposal has many good features, this comment will suggest two improvements. In its present form, the Clinton proposal allows states to set up a single payer system or to organize the insurance market, making heavy use of large regional alliances. I will suggest that states should be allowed a third alternative: to organize the insurance market with small alliances. An advantage of small alliances comes from the distinction between group and individual purchase of insurance, as developed below. The second suggested improvement involves the question of rationing, which is present now and is inevitable in any system for allocating resources; the question is who does it and how. The Clinton plan chooses to offer relatively comprehensive health insurance coverage to all. A more efficient form of rationing might offer basic coverage to all, making more use of individually purchased supplemental policies as part of the rationing mechanism.
The Mammalian Sec6/8 Complex Interacts with Ca2+ Signaling Complexes and Regulates Their Activity

The localization of various Ca2+ transport and signaling proteins in secretory cells is highly restricted, resulting in polarized agonist-stimulated Ca2+ waves. In the present work, we examined the possible roles of the Sec6/8 complex or the exocyst in polarized Ca2+ signaling in pancreatic acinar cells. Immunolocalization by confocal microscopy showed that the Sec6/8 complex is excluded from tight junctions and secretory granules in these cells. The Sec6/8 complex was found in at least two cellular compartments, part of the complex showed similar, but not identical, localization with the Golgi apparatus and part of the complex associated with Ca2+ signaling proteins next to the plasma membrane at the apical pole. Accordingly, immunoprecipitation (IP) of Sec8 did not coimmunoprecipitate βCOP, Golgi 58K protein, or mannosidase II, all Golgi-resident proteins. By contrast, IP of Sec8 coimmunoprecipitates Sec6, type 3 inositol 1,4,5-trisphosphate receptors (IP3R3), and the Gβγ subunit of G proteins from pancreatic acinar cell extracts. Furthermore, the anti-Sec8 antibodies coimmunoprecipitate actin, Sec6, the plasma membrane Ca2+ pump, the G protein subunits Gαq and Gβγ, the β1 isoform of phospholipase C, and the ER resident IP3R1 from brain microsomal extracts. Antibodies against the various signaling and Ca2+ transport proteins coimmunoprecipitate Sec8 and the other signaling proteins. Dissociation of actin filaments in the immunoprecipitate had no effect on the interaction between Sec6 and Sec8, but released the actin and dissociated the interaction between the Sec6/8 complex and Ca2+ signaling proteins. Hence, the interaction between the Sec6/8 and Ca2+ signaling complexes is likely mediated by the actin cytoskeleton. The anti-Sec6 and anti-Sec8 antibodies inhibited Ca2+ signaling at a step upstream of Ca2+ release by IP3. Disruption of the actin cytoskeleton with latrunculin B in intact cells resulted in partial translocation of Sec6 and Sec8 from membranes to the cytosol and interfered with propagation of agonist-evoked Ca2+ waves. Our results suggest that the Sec6/8 complex has multiple roles in secretory cells including governing the polarized expression of Ca2+ signaling complexes and regulation of their activity.
Probing magnetic properties of atoms with STM

The magnetic properties of individual atoms adsorbed on metal and insulating substrates can differ dramatically. While an atom on an insulating substrate can maintain some basic properties such as a free spin, such a free spin is strongly screened by a metal's conduction electrons when the atom is placed directly on the metal. This screening gives rise to the Kondo effect. Scanning Tunneling Microscopy was used to probe the magnetic properties of atoms adsorbed on metals and thin insulating substrates. We find spin-flip spectroscopy for Mn adsorbed on thin aluminum oxide with no sign of Kondo effect. On the other hand Co atoms on Cu substrates show a clear Kondo resonance around the Fermi energy with no sign of spin-flip spectroscopy. Mn atoms very close to the edge of an aluminum oxide patch can recover the Kondo effect albeit with very small Kondo temperatures because of their relative proximity to the conduction electrons of the underlying metal. [DOI: 10.1380/ejssnt.2006.384]
The future of high‐pressure mineral physics

Research in mineral physics is essential in interpreting observational data from many other disciplines in the Earth sciences, including geodynamics, seismology, geochemistry petrology geomagnetism, and planetary science, as well as materials science and climate studies, as illustrated in Figure l. The field of high-pressure mineral physics is highly interdisciplinary and fundamentally multidisciplinary mineral physicists do not always study minerals or use only physics; they study the science of materials that compose the Earth and other planets, and employ concepts and techniques from chemistry physics, materials science, and biology. A dramatic example of this interdisciplinarity in action occurred during the past year. The experimental discovery and theoretical confirmation in 2004 of a new phase of magnesium metasilicate (MgSiO3) stable only at pressures above 100 Gigapascals (and termed the postperovskite phase) has had an immediate and profound impact on multidisciplinary studies of the deep mantle of the Earth (see article by Lay et al. in the 4 January 2005 issue of Eos).
Broadband, low-dispersion, mid-infrared metamaterials

Broad-bandwidth, low-dispersion, optical metamaterials are desired. Reflection measurements show that, by using multiple-metamaterial semiconductor stacks of varying thickness and doping, bandwidth is improved by 47% over a single-stack mid-infrared metamaterial, and dispersion appears reduced.
Effects of maternal consumption of ethanol, barbital, or chlordiazepoxide on the behavior of the offspring.

Female rats received barbital or chlordiazepoxide (CDP) in their drinking water or ethanol in a liquid diet with drug administration beginning before breeding and continuing until the offspring were weaned. Control groups received either tap water and lab chow (untreated controls) or a liquid diet containing sucrose which was delivered in restricted amounts such that it was equicaloric to the diet consumed by the ethanol group. Both birth weight and weight at 1 week of age were reduced by barbital exposure but not by CDP exposure. Growth was reduced slightly in the ethanol group, as compared to the sucrose control group. At 21 days of age the offspring were trained to avoid footshock and retested at 28 days of age. In both sessions the barbital offspring displayed longer avoidance latencies than controls, while the CDP and ethanol groups displayed shorter latencies than controls only during the training session. When trained to respond for food presentation under a fixed-ratio 20 schedule, the response rates of the barbital and CDP groups were less than those of the untreated control group while the response rates of both the ethanol and sucrose groups were greater than those of the untreated control group. When injected with ethanol or pentobarbital, the duration of narcosis was less for the offspring of the CDP- and barbital-treated mothers than for the untreated controls. Ethanol and sucrose offspring were not different in this regard. These results demonstrate that chronic maternal ingestion of ethanol, barbital, or CDP during gestation and nursing can affect the growth, behavior, and drug sensitivity of the offspring.
Using cell and developmental biology to enhance embryo survival in aquaculture

Research on how the young embryo protects itself from normal environmental stresses reveals that the earliest phases of development have unique, innate mechanisms to protect the embryo during this most sensitive phase of embryogenesis. This paper shows ways in which knowledge of these protection mechanisms might be used to advantage in the aquaculture situation. These include novel mechanisms to deter bacteria and fungi such as secretion of anti-bacterial/anti-fungal substances from the egg at fertilization, as well as the utilization of anti-fungal metabolites provided by symbiotic bacteria associated with egg cases. UV damage is avoided by provision of unique sunscreens to the embryos so that UV penetration into the cytoplasm is avoided. Finally, embryos have exaggerated mechanisms to avoid the effect of toxicants on development but these are inadequate to remove pollutants present in feed used in aquaculture. Approaches are suggested on how this knowledge about adaptations might be used in the aquaculture setting to avoid pathogens, increase UV resistance and reduce levels of pollutants.
The electric currents produced by thunderclouds

Abstract Recent measurements show that the Maxwell current densities, J→ m , produced by thunderclouds are quasi-steady at the ground even in the presence of lightning. These measurements also show that J→ m is usually dominated by the displacement current component when the electric field is close to zero; therefore, J→ m can often be estimated from just an electric field measurement. Maps that show the time-development of the pattern of the average J→ m over a relatively large area are given for one Florida thunderstorm. These maps are in good agreement with radar echoes and the locations of lightning charges, and can now be used in further studies of thunderstorm electricity.
Evaluation dilemmas: Conducting evaluation studies in developing countries

This paper examines a series of conceptual issues in conducting evaluations of international technical assistance programs and illustrates those issues with specific examples. The discussion draws heavily on the recent experience of the authors during the evaluation of the Improved Efficiency of Learning Project in Liberia.
Towards patient-based cancer therapeutics

Orienting cancer drug discovery to the patient requires relating the genetic features of tumors to acquired gene and pathway dependencies and identifying small-molecule therapeutics that target them.
Spatial and temporal patterns of surface water quality and ichthyotoxicity in urban and rural river basins in Texas

The Double Mountain Fork Brazos River (Texas, USA) consists of North (NF) and South Forks (SF). The NF receives urban runoff and twice-reclaimed wastewater effluent, whereas the SF flows through primarily rural areas. The objective of this study was to determine and compare associations between standard water quality variables and ichthyotoxicity at a landscape scale that included urban (NF) and rural (SF) sites. Five NF and three SF sites were sampled quarterly from March 2008 to March 2009 for specific conductance, salinity, hardness, pH, temperature, and turbidity; and a zebrafish (Danio rerio) embryo bioassay was used to determine ichthyotoxicity. Metal and nutrient concentrations at all sites were also measured in addition to standard water quality variables in spring 2009. Principal component analyses identified hardness, specific conductance, and salinity as the water variables that best differentiate the urban NF (higher levels) from rural SF habitat. Nutrient levels were also higher in the NF, but no landscape scale patterns in metal concentrations were observed. Ichthyotoxicity was generally higher in NF water especially in winter, and multiple regression analyses suggested a positive association between water hardness and ichthyotoxicity. To test for the potential influence of the toxic golden alga (Prymnesium parvum) on overall ichthyotoxicity, a cofactor known to enhance golden alga toxin activity was used in the bioassays. Golden alga ichthyotoxicity was detected in the NF but not the SF, suggesting golden alga may have contributed to overall ichthyotoxicity in the urban but not in the rural system. In conclusion, the physicochemistry of the urban-influenced NF water was conducive to the expression of ichthyotoxicity and also point to water hardness as a novel factor influencing golden alga ichthyotoxicity in surface waters.
Two major autoantigen—Antibody systems of the mitotic spindle apparatus†

Objective. To characterize human autoantigen-antibody systems related to the mitotic poles and spindles. Methods. Thirty-seven human sera with autoantibodies staining mitotic poles and spindles in indirect immunofluorescence (IIF) studies were further characterized by immunofluorescence on mitotic cells and by immunoblotting and immunoprecipitation. Clinical diagnoses meeting the American College of Rheumatology criteria were based on chart review and interview with the corresponding physicians. Results. Two autoantibody systems reactive with mitotic poles and spindles were defined. Type 1 nuclear mitotic apparatus (NuMA-1) antibodies were identified in the serum of 30 patients. Interphase cells showed a fine, speckled, nuclear staining, while mitotic cells had bright staining of the rim of the centrosomes and light staining of the spindles proximal to the centrosomes. In telophase, the staining shifted from the centrosomes to the reforming nuclei. On immunoblotting, anti—NuMA-1 sera reacted with a 210-kd protein. The reactivity of these sera was identified (with the aid of reference antibodies) as the previously described NuMA antigen—antibody system. Clinical information was available for only 17 of the 30 patients with anti—NuMA-1; of these, 17 (53%) had clinical and lip biopsy findings that met the criteria for Sjogren's syndrome. NuMA-2 antibodies were found in the sera of 7 patients. Interphase cells showed no nuclear or cytoplasmic staining, but mitotic cells had brightly stained poles and spindles. At anaphase/telophase, staining shifted to the midbody and the intercellular bridge. Anti—NuMA-2 sera immunoprecipitated a protein of 116 kd. This group of patients was more heterogeneous and had both systemic and organ-specific autoimmune diseases. Conclusion. NuMA protein (here called NuMA-1) and a 116-kd protein (here called NuMA-2) are the major targets of the autoimmune response in the mitotic apparatus, since most of the selected sera (based on IIF staining of the mitotic spindles and poles) recognized 1 of these 2 antigens.
The Integumental Perforation Pattern of the Euchirella Messinensis Female (Copepoda, Calanoida): Corrections, Additions, Intraspecific Variation, and a Checklist of Pore Sites

[En preparation pour l'exploitation du modele de perforation tegumentaire dans une analyse phylogenetique du genre Euchirella, le modele de perforation d'Euchirella messinensis, tel que donne par Von Vaupel Klein (1982c), est critiquement evalue. Les 392 sites sont montres sur les illustration et mentionnes sur une liste commentee. Le concept de paires associees et les mecanismes possibles a l'origine des sites variables sont discutes. La variation intraspecifique semble limitee: la plupart des specimens montrent quelques aberrations par rapport au modele regulier de perforations, mais seulement en un petit nombre de sites (moyenne: 1,85; maximum: 4). L'analyse du modele revele que la variation observee est independante de la localisation de l'echantillon (excepte pour deux sites) et des anomalies macro-morphologiques. Ceci fait du modele de perforation tegumentaire une serie de caracteres potentiellement utile dans (l'evaluation des precedentes) analyses phylogenetiques., En preparation pour l'exploitation du modele de perforation tegumentaire dans une analyse phylogenetique du genre Euchirella, le modele de perforation d'Euchirella messinensis, tel que donne par Von Vaupel Klein (1982c), est critiquement evalue. Les 392 sites sont montres sur les illustration et mentionnes sur une liste commentee. Le concept de paires associees et les mecanismes possibles a l'origine des sites variables sont discutes. La variation intraspecifique semble limitee: la plupart des specimens montrent quelques aberrations par rapport au modele regulier de perforations, mais seulement en un petit nombre de sites (moyenne: 1,85; maximum: 4). L'analyse du modele revele que la variation observee est independante de la localisation de l'echantillon (excepte pour deux sites) et des anomalies macro-morphologiques. Ceci fait du modele de perforation tegumentaire une serie de caracteres potentiellement utile dans (l'evaluation des precedentes) analyses phylogenetiques.]
A finite element for analysis of elbows subjected to different loads and end constraints

Abstract Simple beam theory may be applied to straight lengths, but the behavior of curved pipes 1subjected to bending is complex. In the present work an arbitrary shaped curved shell element suitable to analyse the pipe elbows is presented. The accuracy of three orders of this element has been studied. Their accuracy has been further compared with other shell finite elements. A complete ring element using trigonometric functions for displacements and geometry has been developed to study the pipe bend problem. An estimate of the accuracy of the current shell element has been obtained by comparing the results obtained for the same problem with the help of three-dimensional elements. The stress and flexibility factors thus obtained have been analyzed and conclusions reached.
The structure of the stable roomate problem: efficient representation and enumeration of all stable assignments

The stable roommates problem is a well-known problem of matching $2n$ people into disjoint pairs to achieve a certain type of stability. The problem strictly generalizes the better-known stable marriage problem. It has been previously shown [Irving and Leather, SIAM J. Comput., 15 (1986), pp. 655–667], that the set of stable marriages, for a given instance, can be compactly represented and this representation has been exploited to yield a number of very efficient algorithms concerned with stable marriage [Irving, Leather, and Gusfield, J. Assoc. Comput. Mach., 34 (1987), pp. 532–543], [Gusfield, SIAM J. Comput., 16 (1987), pp. 111–128], [Gusfield et al., J. Combin. Theory, Ser A., (1987), pp. 304–309]. In this paper, we generalize the structure of the stable marriages to obtain two efficiently computed, small, implicit representations of the set of all stable roommate assignments, for any given instance. One representation is a partial order $\Pi $ on $O(n^2 )$ elements such that the stable assignments ar...
No Simple Pattern of Inheritance in Ability to smell Solutions of Cyanide

IN I950, at the Cold Spring Harbor Symposium on the origin and evolution of man, Mourant commented: “It is most important that more new markers be sought and found for the human chromosomes.” As an example of a possible new marker he remarked that: “One person out of four fails to smell hydrogen cyanide, a proportion suggesting a balanced polymorphism”1.
Genomic organization of rat rDNA

A detailed restriction map was determined for a 10.9 KB region that contains the initiation site for 45S pre-rRNA and the first 1.7 KB of the 18S rRNA coding region. When the restriction pattern of the cloned rDNA was compared with that of total rat DNA, the rDNA regions of both Sprague-Dawley and BD-9 rats were identical to each other and to that of the cloned rDNA. However, both strains exhibit a major polymorphism consisting of an insertion of 0.9 KB of DNA in the nontranscribed spacer between 0.29 KB and 1.8 KB upstream from the 45S RNA initiation site. This region consists of tandem repeats approximately 130 base pairs in length. These repeats contain large poly T tracts and are similar in sequence to analogous elements 5' to the origin of mouse rRNA transcription. Regions containing highly repetitious DNA sequences were located at sites 2.8 KB and 4.3 KB upstream from the initiation site. The repetitive sequence at 2.8 KB from the initiation site anneal to a known Alu-equivalent type 2 sequence derived from the second intron of the rat growth hormone gene.
Excitation of interstellar hydrogen chloride

We have computed new rate coefficients for the collisional excitation of HCl by He, in the close-coupled formalism and using an interaction potential determined recently by Willey, Choong, & DeLucia. Results have been obtained for temperatures between 10 K and 300 K. With the use of the infinite order sudden approximation, we have derived approximate expressions of general applicability which may be used to estimate how the rate constant for a transition (J to J prime) is apportioned among the various hyperfine states F prime of the final state J prime. Using these new rate coefficients, we have obtained predictions for the HCl rotational line strengths expected from a dense clump of interstellar gas, as a function of the HCl fractional abundance. Over a wide range of HCl abundances, we have found that the line luminosities are proportional to abundance(exp 2/3), a general result which can be explained using a simple analytical approximation. Our model for the excitation of HCl within a dense molecular cloud core indicates that the J = 1 goes to 0 line strengths measured by Blake, Keene, & Phillips toward the Orion Molecular Cloud (OMC-1) imply a fractional abundance n(HCl)/n(H2) approximately 2 x 10(exp -9), a value which amounts to only approximately 0.3% of the cosmic abundance of chlorine nuclei. Given a fractional abundance of 2 x 10(exp -9), the contribution of HCl emission to the total radiative cooling of a dense clump is small. For Orion, we predict a flux approximately 10(exp -19) W/sq cm for the HCl J = 3 goes to 2 line near 159.8 micrometers, suggesting that the strength of this line could be measured using the Infrared Space Observatory.
Flow condensation in horizontal tubes

Abstract This study examines condensation heat transfer in horizontal channels. Two separate condensation modules are tested using FC-72 as condensing fluid and water as coolant. The first module is dedicated to obtaining detailed heat transfer measurements of the condensing flow, and the second to video capture of the condensation film’s interfacial behavior. Four dominant flow regimes are identified: smooth-annular, wavy-annular, stratified-wavy and stratified, whose boundaries show fair agreement with published flow regime maps. The film’s interface is observed to feature an array of small ripples and relatively large waves, with the largest waves tending to merge into yet larger waves having greater liquid mass, amplitude and speed. This behavior is believed to influence condensation heat transfer, especially downstream. The local condensation heat transfer coefficient is highest near the inlet, where quality is near unity and the film thinnest, and decreases monotonically in the axial direction in response to the film thickening. This variation is very sensitive to the mass velocity of FC-72, and the heat transfer coefficient decreases sharply in the inlet region but this decrease slows significantly in the downstream region because of the combined effects of turbulence and interfacial waviness. The measured condensation heat transfer coefficient shows good agreement with a select number of correlations.
Using fish stomachs as samplers of the benthos: integrating long-term and broad scales

Sampling benthic organisms in a synoptic manner is difficult, particularly at the scale of large marine ecosystems. Several known omnivorous and benthivorous fishes were evaluated as pos- sible samplers of the benthic community on the scale of the US northeast continental shelf ecosystem, collected from the early 1970s to 2001. Frequency of occurrence of organisms in the diet across time was examined as an index of relative abundance. Other prey and sampling caveats were accounted for by considering only those predators that met criteria such as adequate sample size, appropriate diet compositions, asymptotic stomach-prey curves, and relative constancy of all major prey groups comprising the diet. The geographic distribution of a suite of benthic organisms found in the stom- achs of predators was also examined. The benthic organisms focused on were ophiuroids, echinoids, holothuroideans, asteroids, octopods, stomatopods, cumaceans, pagurids, aphroditids, anthozoans, hydrozoans and caprellids. Of these 12 prey groups, only 3 showed a decline over time based on evi- dence from multiple predator stomachs. Most benthic organisms exhibited non-negative trends in an index of relative abundance, and 2 showed an increase over the time-series. Additionally, many of the organisms were widely distributed, with some concentrated more on Georges Bank and others more in the Gulf of Maine. Only 1 of 9 organisms showed a shift in distribution compared to studies from 50 yr earlier. I conclude that at broad spatial and temporal scales, the routine and systematic sampling of fish stomachs can be a useful indirect method for inferring information about benthic communities on continental shelves.
Fuzzy hybrid systems modeling

A hybrid system is a system containing a mixture of discrete event components and continuous variable components. The existing hybrid system modeling methods are effective to handle crisp cases but difficult to represent deterministic uncertainties and subjectivity inherent in many real-world applications, especially those in biomedicine. We recently extended the framework of discrete event systems to a framework of fuzzy discrete systems [1–2]. In the present paper, we generalize the crisp hybrid system framework to a fuzzy hybrid system framework by using fuzzy set theory. The former contains the latter as a special case. Membership grades of fuzzy sets are utilized to represent vague system's states and variables. We have also developed a computational algorithm to calculate fuzzy states and state transitions.
Within-day drinking water consumption patterns: Results from a drinking water consumption survey

Data currently available on drinking water intakes do not support dietary exposure estimates for contaminants that have acute effects lasting less than 24 h. Realistic exposure estimates for these types of contaminants in drinking water require detailed information on amounts and time of consumption for each drinking occasion during a day. A nationwide water consumption survey was conducted to address how often, when, and how much water is consumed at specific times during the day. The survey was conducted in two waves, to represent two seasons, and the survey instrument consisted of 7-day water consumption diaries. Data on total daily amounts consumed, number of drinking occasions per day, amounts consumed per drinking occasion, and intervals between drinking occasions show larger between-subjects variation than within-subject variation. Statistically significant associations were also observed between drinking water consumption patterns and participants' ages and sex and geographical regions in which these participants live. The number of drinking occasions on a given day varied from 0 to 19, with the majority of respondents reporting 6 or less drinking occasions per day. The average interval between drinking occasions varied from 1 to 17 h, with 57% of the person-days reporting average intervals at least 3 h apart. The mean amount consumed per drinking occasion showed little association with the number of drinking occasions and fluctuated between 8 and 10 oz. To our knowledge, this survey is the only source of information on within-day patterns (i.e., when and how much) of drinking water consumption for a nationally representative sample of the US population. The detailed water consumption data from this survey can be used to support less than 24-h dietary exposure estimates for contaminants in drinking water.
Numerical modeling of textured silicon solar cells using PC-1D

PC-1D is a quasi-one-dimensional finite-element program for modeling semiconductor devices on personal computers. The program offers solar cell researchers a convenient user interface with the ability to address complex issues associated with heavy doping, high-level injection, nonplanar structures, and transients. The physical and numerical models used in PC-1D Version 2 that make it possible to approximate the multidimensional effects found in textured crystalline silicon solar cells, including the effects of increased front-surface recombination, oblique photon path angles, and light trapping, are presented. As an example of how the model can be applied, PC-1D is used to investigate the interpretation of spectral quantum efficiency data as a tool for diagnosing the internal performance of textured silicon solar cells. >
Models of the Boston Anti‐Busing Movement: Polity/Mobilization and Relative Deprivation*

Polity/mobilization theorists argue that social movements grow out of struggles over membership in the polity. They also maintain that group solidarity facilitates the mobilization process. Relative deprivation theorists argue that feelings of deprivation account for social movement participation. Data on the Boston anti-busing movement provide support for both theories. Based on this finding, a model is developed that incorporates both sets of factors.
LABORATORY-DETERMINED RATES OF OXYGEN DEMAND AND IRON AND MANGANESE RELEASE FROM SEDIMENTS

ABSTRACT A technique was developed for determining the sediment oxygen demand (SOD) and iron and manganese release rates under laboratory conditions. Site-specific comparisons of this method with the EPA in situ technique, indicated a consistently lower SOD rate but improved reliability. Manganese release began as the dissolved oxygen concentration approached 1 mg/L and below. Iron release did not begin until –100 to –150 mv oxidation reduction potential was reached. A high degree of consistency was indicated between replicates. Laboratory and in situ SOD rates yielded a two-dimensional model of reservoir oxygen budgets. The laboratory rate compared favorably to the assumed SOD rate of the model. As a result, TVA has incorporated the laboratory-determined rates and iron and manganese release rates into the reservoir management planning process. Specific measured and modeled rates determine waste load allocations for several reservoirs.
Hemodynamics of multiple versus single 50 percent coronary arterial stenoses

Abstract The purpose of this study was to compare coronary blood flow in the presence of multiple fixed coronary arterial stenoses with that in the presence of a single stenosis of equivalent length and diameter. The study was performed using an in vitro pulse duplicating system. The aortic root section consisted of an acrylic mold of the root of the aorta of a calf. The coronary system was designed to produce coronary flow with physiologic magnitudes and phasic patterns. Aortic and left ventricular pressures as well as the reduction in pressure across the coronary test section containing the stenotic segments were measured with catheter-tip micromanometers. Coronary flow was measured with a cannulating electromagnetic flow transducer. The fluid viscosity was 0.04 poise. Studies were performed sequentially with one 2 mm long arterial segment with a stenosis of 50 percent of luminal diameter, two such stenotic segments and three such stenotic segments in series. A single 4 mm long, 50 percent diameter stenotic segment and a 6 mm long, 50 percent diameter stenotic segment were also studied. The heart rate was 71 beats/min, stroke volume 80 ml and aortic pressure 140 75 mm Hg . A single 2 mm long, 50 percent stenotic segment caused a 6 percent reduction of coronary flow; three such stenoses in series caused a 19 percent reduction of coronary flow. In contrast, a single 6 mm long, 50 percent diameter stenotic segment caused only an 8 percent reduction of coronary flow. The results suggest that in a maximally dilated coronary bed, a greater reduction of coronary flow would occur in the presence of multiple short stenoses than in the presence of a single stenosis of equivalent length and diameter.
Optical Intensities of Rare-Earth Ions in Yttrium Orthoaluminate

Optical absorption and emission intensities are investigated for trivalent rare earths in YAl${\mathrm{O}}_{3}$. Ions examined included Pr, Nd, Eu, Tb, Ho, Er, Tm, and Yb. Oscillation strengths of $f\ensuremath{\rightarrow}f$ transitions between $J$ manifolds were measured at room temperature and compared with calculated electric and magnetic dipole oscillator strengths. The Judd-Ofelt approach and phenomenological parameters for each ion were used to derive the electric dipole intensities. The intensity parameters, which were obtained for a least-square-fitting procedure, exhibited a general decrease with increasing number of $4f$ electrons throughout most of the series. The intensities for Pr and Tb were not satisfactorily accounted for in the present theory; some reasons for this are presented.
Development and validation of a model for predicting the performance of a downhole pneumatic turbine-powered drilling engine

Abstract The pneumatic turbine-powered drilling engine (PTDE) is a unique tool for directional drilling when using air or gas as the drilling fluid. The engine consists of a pneumatic turbine motor coupled to the bit by a four-stage planetary gear transmission and a thrust-bearing assembly, and is supported within a steel housing. The tool was built and bench tested in New Mexico, and field tested at the Geysers Geothermal Field in Santa Rosa (Calif.). In order to predict and analyze the field performance of the tool, two analytical models were derived and validated. A torque model was developed to predict the bit torque as a function of bit rpm at a given air-flow rate and a known air speed entering the turbine rotor. A pressure-loss model was used to calculate the air speed entering the rotor as a function of the bottomhole air pressure, the bottomhole temperature, the air-flow rate, the size of the bit jets, and the tool internal geometry. The two models were validated in a full-scale bench test of the two prototype tools. The validated models were then used to develop turbine air speed and WOB response charts. These charts are for field use in selecting the engine set-up. They are used to select bit jets, and to predict required weight on bit, bit rotary speed, bit torque and bit horsepower.
Distributed Control Techniques in Microgrids

The objective of this paper is to provide a review of distributed control and management strategies for the next generation power system in the context of microgrids. This paper also identifies future research directions. The next generation power system, also referred to as the smart grid, is distinct from the existing power system due to its extensive use of integrated communication, advanced components such as power electronics, sensing, and measurement, and advanced control technologies. At the same time, the need for increased number of small distributed and renewable energy resources can exceed the capabilities of an available computational resource. Therefore, the recent literature has seen a significant research effort on dividing the control task among different units, which gives rise to the development of several distributed techniques. This paper discusses features and characteristics of these techniques, and identifies challenges and opportunities ahead. The paper also discusses the relationship between distributed control and hierarchical control.