cssi/SciSciGPT-SciSciNet huggingface dataset:
The moving junction, a key portal to host cell invasion by apicomplexan parasites

One defining feature of apicomplexan parasites is their special ability to actively invade host cells. Although rapid, invasion is a complicated process that requires coordinated activities of host cell attachment, protein secretion, and motility by the parasite. Central to this process is the establishment of a structure called moving junction (MJ), which forms a tight connection between invading parasite and host cell membranes through which the parasite passes to enter into the host. Although recognized microscopically for decades, molecular characterization of the MJ was only enabled by the recent discovery of components that make up this multi-protein complex. Exciting progress made during the past few years on both the structure and function of the components of the MJ is reviewed here.
Raman Effect in Gases

SINCE the discovery of the Raman effect in scattered light, investigation has been extended to a large number of substances in the solid and liquid state. So far as I know, practically nothing has been done on gases, if we except an observation on ether vapour by Ramdas. Of course, the main difficulty in the case of gases consists in the extreme weakness of the scattered radiation.
Introduction to the series of reactive and abnormal lymphoid proliferations mimicking malignant lymphoma

The series of articles in this issue of Seminars in Diagnostic Pathology will focus on atypical lymphoid proliferations that may mimic malignant lymphoma, conditions that may be associated with an increased risk of developing malignant lymphoma, and in-situ lymphomatous lesions. Even with the increasing array and sophistication of diagnostic techniques (i.e., flow cytometric immunophenotyping, cytogenetic, molecular, and viral probes, etc.) available to analyze these proliferations, fundamental questions persist as to the absolute criteria that should be used in defining the various processes encountered in these situations. Indeed, although advances in diagnostic techniques with increasing sensitivity provide us with powerful tools to detect apparently abnormal populations of lymphoid cells, it is sometimes challenging to distinguish self-limited or clinically insignificant clonal expansions from early involvement by lymphoproliferative disorders destined to become symptomatic, requiring therapy. This area of diagnostic hematopathology is particularly challenging due to the fact that there are numerous clinicopathologic factors resulting from or influencing the pathogenesis, diagnosis, clinical course, and treatment of these lymphoproliferative disorders/neoplasms. Such factors include (but are not limited to) the following:
Cardiac venous blood flow in atrial pacing versus exercise-induced angina pectoris

Abstract Thirteen patients with angina pectoris underwent measurements of great cardiac vein blood flow at rest, with the onset of angina pectoris induced by atrial pacing, and again during angina pectoris induced by exercise in order to compare the regional coronary blood flow response to differing myocardial stresses. All patients had significant obstructions of the left anterior descending artery. Exercise-induced angina, compared to pacing-induced angina, was associated with a higher systolic pressure, higher left ventricular end-diastolic pressure, and a lower heart rate. Indices of myocardial oxygen demand, that is, the systolic pressure-heart rate product and the tension-time index, increased to a similar degree during both types of myocardial stress and great cardiac vein blood flow paralleled these changes. We conclude that in a given patient the level of regional coronary blood flow is similar at the onset of either pacing- or exercise-induced angina, despite significant differences in the hemodynamic response to these myocardial stresses.
Analysis of Yaba tumor poxvirus-induced proteins in infected cells by two-dimensional gel electrophoresis.

Abstract Lack of inhibition of host protein synthesis by Yaba tumor poxvirus and comigration of viral and host proteins did not interfere with high resolution of virus-induced proteins when two-dimensional gel electrophoresis was employed. A total of 84 virus-induced proteins, 44 structural and 40 nonstructural, comprising 62.9% of the coding capacity of Yaba virus DNA, were detected. These proteins may be further categorized in two classes: early, synthesized in the presence of DNA inhibitor, Ara-c; and late, beginning at 6 hr p.i. with the bulk of viral protein synthesis occurring later than 30 hr p.i. The rate of synthesis of viral proteins fell into two patterns: group A, in which the rate of synthesis decreased; and, group B, in which the rate of synthesis increased after the initial appearance of the protein.
Cation ordering in complex oxides

Several recent papers have addressed the fundamental aspects of the stability and kinetics of ordering in complex oxides, and investigated systems where the properties are mediated by the degree of order. Cation ordering reactions have been shown to induce large alterations in the dielectric, ferroelectric, magnetic, and electronic response of many complex oxides. The majority of the cited publications focus on ion ordering in perovskite-related structures; however, additional examples include the ordering of structural slabs and formation of modulated intergrowth structures.
Electroporation: a unified, quantitative theory of reversible electrical breakdown and mechanical rupture in artificial planar bilayer membranes☆

Abstract We present a quantitative theory of electroporation of artificial planar lipid bilayer membranes. Assuming that aqueous pores are involved in electroporation, we describe the pore population of the membrane by the density function n (r, t), where n (r, t) dr is the number of pores with radius between r and r + dr at time t. We further assume that there is a minimum pore size rmin, that pores of radius rmin are created and destroyed by thermal fluctuations, and that the pore creation rate is proportional to exp(aΔφm2/kT, where a is a constant, Δφm is the membrane voltage, k is Boltzmann's constant, and T is the absolute temperature. We use a simple formula for the conductance of a pore as a function of radius, the expression for the pore energy previously derived by Pastushenko and Chizmadzhev, and a simple model of the external circuit. We solve the equations numerically and compare the solutions to the results of charge pulse experiments. In a charge-pulse experiment a membrane suffers one of four possible fates: (1) a slight increase in electrical conductance, (2) mechanical rupture, (3) incomplete reversible electrical breakdown, resulting in incomplete discharge of the membrane, or (4) reversible electrical breakdown (REB), resulting in complete discharge of the membrane. In agreement with experiment, this theory describes these four fates and predicts that the fate in any particular experiment is determined by the properties of the membrane and the duration and amplitude of the charging pulse.
Mitochondrial hyperpolarization: a checkpoint of T-cell life, death and autoimmunity.

T-cell activation, proliferation and selection of the cell death pathway depend on the production of reactive oxygen intermediates (ROIs) and ATP synthesis, which are tightly regulated by the mitochondrial transmembrane potential (ΔΨm). Mitochondrial hyperpolarization (MHP) and ATP depletion represent early and reversible steps in T-cell activation and apoptosis. By contrast, T cells of patients with systemic lupus erythematosus (SLE) exhibit persistent MHP, cytoplasmic alkalinization, increased ROI production and depleted ATP, which mediate enhanced spontaneous and diminished activation-induced apoptosis and sensitize lupus T cells to necrosis. Necrotic, but not apoptotic, cell lysates activate dendritic cells and might account for increased interferon a production and inflammation in lupus patients. MHP is proposed as a key mechanism of SLE pathogenesis and is therefore a target for pharmacological intervention.
Is hypotonic dysfunctional labor associated with hypophosphatemia

Abstract Objective The purpose of this study was to determine whether hypotonic dysfunctional labor is associated with hypophosphatemia. Study design We conducted a prospective nested case control study of term women who were in active labor. Serum phosphate samples were drawn at admission with active labor and before delivery. Phosphate concentration was compared between control subjects and women with hypotonic, dysfunctional uterine contractions. Results Both serum samples were available for 90 women. Hypophosphatemia was documented in 14% of the participants. There was no significant difference in phosphate concentration between the 2 groups either at admission or before delivery. The mean decrease in phosphate concentration between admission and delivery was similar between the 2 cohorts. Conclusion Although transient hypophosphatemia is found commonly in laboring women, hypotonic dysfunctional contractions are not associated with mild hypophosphatemia.
The geometry of sectional curvatures

A large class of questions in differential geometry involves the relationship between the geometry and the topology of a Riemannian (= positive-definite) manifold. We briefly review the status of the following question from this class: given that a compact, even-dimensional manifold admits a Riemannian metric of positive sectional curvatures, what can one say about its topology? Very few manifolds are known to admit such metrics. For example, is it not known whether or not the product of then-sphere with itself (n ≥ 2) does. One answer to the question above is provided by Synge's theorem: if the manifold is orientable, then it is simply connected. Another possible answer is given by the Hopf conjecture: such a manifold necessarily has positive Euler number. The Hopf conjecture is known to be true for homogeneous manifolds, and for arbitrary manifolds in dimensions two and four. This last result has two, apparently entirely different, proofs, one using Synge's theorem and the other the Gauss-Bonnet formula. Neither, it is shown, can be generalized directly to dimensions six or greater. The Hopf conjecture in these higher dimensions remains open.
Gains of Chromosome 8 in Pleuropulmonary Blastomas of Childhood (Reply)

We thank Drs. Sebire and colleagues for presenting their data that corroborates our recently reported findings [1]. Their four new cases bring the total number of reports on cytogenetic findings in pleuropulmonary blastoma (PPB) to 14. Twelve of the 14 cases have shown relative excesses in material from chromosome 8. The remaining two cases have shown gains in chromosome 8 that, in the setting of other numerical abnormalities, may not represent relative gains. We too are beginning to feel that cytogenetic analysis may play a useful role in the interpretation of certain diagnostically difficult childhood thoracic neoplasms. Within the last month, we applied the technique to an unusual case of a 4-year-old boy whose medical records had been lost at a hospital in Haiti. He presented with a tumor replacing the left hemithorax. He had a healed abdominal midline incision and a radiologically absent kidney. The mother stated that a mass had been removed at the age of 2. Needle biopsies of the thoracic mass showed tumor cells with an embryonal pattern of rhabdomyoblastic differentiation; epithelium, suspected to represent underlying lung, was also present. The histologic differential diagnosis included metastatic Wilms tumor with prominent rhabdomyoblastic differentiation, rhabdomyosarcoma metastatic from an abdominal primary, or PPB. Karyotype was 73763n,XXY,
Dynamically Focused Gaussian Beams for Seismic Imaging

An initial study is performed in which dynamically focused Gaussian beams are investigated for seismic imaging. Focused Gaussian beams away from the source and receiver plane allow the narrowest and planar portions of the beams to occur at the depth of a specific target structure. To match the seismic data, quadratic phase corrections are required for the local slant stacks of the surface data. To provide additional control of the imaging process, dynamic focusing is investigated where all subsurface points are specified to have the same planar beam fronts. This gives the effect of using nondiffracting beams, but actually results from the use of multiple focusing depths for each Gaussian beam. However, now different local slant stacks must be performed depending on the position of the subsurface scattering point. To speed up the process, slant stacking of the local data windows is varied to match the focusing depths along individual beams when tracked back into the medium. The approach is tested with a simple model of 5-point scatterers which are then imaged with the data, and then to the imaging of a single dynamically focused beam for one shot gather computed from the Sigsbee2A model.
A Personal Voyage of Exploration through the Literature of Abortion History

When the review editor asked me to write an essay on Leslie J. Reagan's When Abortion Was a Crime, initially I begged off on the basis that I did not know much about the history of abortion. He persisted, and I agreed to try it, but only if I could write the piece as a sort of intellectual voyage of discovery. I would describe the literature's flora and fauna, the mountains and seas, make some comparative analyses, and briefly state my own personal reaction. It would not be a Baedeker guidebook by any means, more like a sketchy tourist account.
A lack of reactivity of D-arabinose 5-phosphate with enzymes of the pentose phosphate pathway.

Abstract The reported conversion of d -arabinose 5-phosphate to d -ribose 5-phosphate and other intermediates of the pentose phosphate pathway was investigated. Two new solvent systems to separate the two aldopentose phosphates on paper and a method using chromatography on a column of dihydroxyboryl-cellulose were developed. No evidence for their interconversion could be obtained. d -Arabinose 5-phosphate did not serve as an acceptor for transketolase from bakers' yeast, Candida utilis , or rat liver but behaved as an inhibitor. d -Glucose 6-phosphate acted both as an acceptor and as an inhibitor of the reaction with d -ribose 5-phosphate as acceptor. d -Arabinose 5-phosphate was not converted into ribose 5-phosphate, ketopentose phosphate, triose phosphate, or a heptulose phosphate by rat muscle or rat liver enzymes. Hydroxypyruvate is suggested not to be a substrate for rat liver transketolase.
Systematic use of the RAM nasal cannula in the Yale–New Haven Children’s Hospital Neonatal Intensive Care Unit: a quality improvement project

AbstractObjective: To evaluate the clinical efficacy of the RAM nasal cannula (NC) with different modes of non-invasive ventilation (NIV) in the neonatal intensive care unit (NICU).Methods: A single center prospective, observational study of infants placed on RAM NC. A small trial (Study 1) was completed in 16 infants on NIV via the RAM NC over a 48-h period to create Summary Statement recommendations. Next, over a 10-month period (Study 2), data were prospectively collected for the outcome of all infants receiving respiratory support with the RAM NC. Outcomes were compared between different modes of NIV and whether the recommendations were followed.Results: The Study 2 population consisted of 88 infants of whom 67 infants received nasal continuous positive airway pressure ventilation (NCPAP) and 21 received nasal intermittent positive pressure ventilation (NIPPV) via the RAM NC. The NIPPV group tended to be younger, smaller and stayed on the RAM NC longer. The overall success rate in weaning off the RAM ...
Fluorescence measurements of expanding strongly coupled neutral plasmas.

We report new detailed density profile measurements in expanding strongly coupled neutral calcium plasmas. Using laser-induced fluorescence techniques, we determine plasma densities in the range of 10{sup 5} to 10{sup 9} cm{sup -3} with a time resolution limit as small as 7 ns. Strong coupling in the plasma ions is inferred directly from the fluorescence signals. Evidence for strong coupling at late times is presented, confirming a recent theoretical result.
Dynamic forces in multiport mechanics: Direct and Lagrangian formulations

Abstract Holonomic systems can be represented by a bond graph in which inertial variables are related to generalized variables using a multiport displacement-modulated transformer structure. It is shown that the part of the generalized forces due to inertial elements can be found either by direct calculation or by the operations of Lagrange's equations. Although no gyrators are needed for the representation, gyrational coupling may exist. Alternative representations may involve gyrators explicitly and it is possible to construct kinetic co-energy functions for these gyrators for use in Lagrange's equations.
Low concentrations of sodium azide specifically inhibit a thromboxane A2 pathway in human platelets.

Abstract Sodium azide completely inhibits the serotonin release induced by ADP, arachidonic acid and the thromboxane A2 mimetic U46619, but does not have any effect on the activation by PMA. Collagen and thrombin are inhibited when used at low concentrations, but not at high concentration. This pattern of activation suggests that the inhibition by azide is not a metabolic inhibition. The antagonism of U46619-induced secretion was further studied and was shown to be non-competitive. It is selective for certain components of the U46619 stimulus-response coupling: aggregation, serotonin secretion and the activation of protein kinase C are completely or almost completely inhibited by 300 μM sodium azide. Shape change, calcium elevation, cytoplasmic alkalinization and phosphorylation of myosin light chain are only partially modified. This suggests that azide may specifically inhibit one of the different forms of thromboxane A2 receptors present in platelets.
Stretching, sliding and strategy: indexicality in algebraic explanations

In this study, we describe the linguistic expression of strategy in explanations of algebraic procedures. Stating the steps of an algebraic procedure does not require a student to indicate the relationship between different mathematical actions, but describing algebraic strategy does. The coordinated nature of strategic proficiency suggests that linguistic forms known as indexical language, “pointing words” that link speech to context, may be fundamental resources for expressing this type of competence. A class of first-year university mathematics students developed a habit of reporting procedures that we consider a speech genre. The classroom genre emphasised procedural explanations, but when students expressed strategic competence, they often relied on indexical language. Indexical verbs of motion like slide and drop proved to be a particularly efficient means of expressing algebraic strategies. This informal speech style extended the communicative capacity of the classroom speech genre, and allowed cla...
Case report: poorly differentiated carcinoma of unknown primary presenting as Trousseau's syndrome.

ABSTRACT Two patients without clinical evidence of malignancy had idiopathic migratory thrombophlebitis. A clinical state consistent with Trousseau's syndrome prompted a work-up of each patient for occult cancer. In both individuals, computed tomography of the chest revealed a solitary mediastinal lymph node that, though inconspicuous, was evaluated further because of the clinical picture. Mediastinoscopy with biopsy revealed poorly differentiated carcinoma. Treatment was begun for carcinoma of unknown primary with variable response to therapy. The clinical presentation and pathophysiology of Trousseau's syndrome, as well as its use in leading to an antemortem diagnosis of occult cancer in these and other patients, are delineated.
An intermediate-purity factor VIII concentrate supports platelet adhesion under flow conditions

Von Willebrand factor (vWF) binds to platelets and mediates platelet adhesion to subendothelium to support haemostasis. Factor VIII concentrates containing vWF have been recommended for treatment of bleeding episodes in von Willebrand disease (vWD) types 2 and 3. Their clinical efficacy in normalizing FVIII coagulant levels, shortening the bleeding time, stopping or preventing clinical bleeding and safety have been tested. However, the basic mechanisms of their effects on haemostasis have not been fully characterized. We have analysed the ability of vWF present in an intermediate-purity factor VIII concentrate (Haemate-P, Centeon) to bind to platelets (ultrastructural studies) and to support platelet adhesion under flow conditions (perfusion studies). For this purpose, Haemate-P or cryoprecipitate was added to washed platelet suspensions, or to vWF-depleted reconstituted healthy anticoagulated blood. Immunoelectron microscopy (IEM) revealed vWF arrangements on platelet surfaces which have been exposed to mixtures of the vWF-rich concentrate plus ristocetin. vWF levels in perfusates were confirmed by determination of ristocetin co-factor and vWF-antigen. Baumgartner's perfusion method and computer-assisted morphometry were used to evaluate platelet adhesion of the perfusates onto everted rabbit aorta subendothelium under standardized conditions (shear rate, 800 s(-1) , 10 min, 37 °C). vWF-depleted perfusates showed 15.8% (SEM 1.7) total covered surface (CS) with platelets. An increase in CS resulted when 0.40 or 0.80 IU vWF mL(-1) from Haemate-P (30.1%, SEM 3.0, P<0.05; 39.4%, SEM 3.1, P<0.008, respectively) were added. A similar increase was observed when cryoprecipitate was added to perfusates (28.6%, SEM 2.4, P<0.05 for 0.40 IU vWF mL(-1) ; 27.2%, SEM 2.9, P<0.01 for 0.80 IU vWF mL(-1) ). IEM confirmed that vWF from concentrates binds to platelets. Furthermore, perfusion studies revealed that the fractionated vWF supports platelet adhesion, thus providing experimental evidence of the therapeutic benefits exerted by Haemate-P.
Bis(monoacylglycero)phosphate and ganglioside GM1 spontaneously form small homogeneous vesicles at specific concentrations

Abstract The morphology and size of hydrated lipid dispersions of bis(monoacylglycero)phosphate (BMP) mixed with varying mole percentages of the ganglioside GM1 were investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Electron paramagnetic resonance (EPR) spectroscopy of these same mixtures, doped at 0.5 mol% with doxyl labeled lipids, was used to investigate acyl-chain packing. Results show that for 20–30% GM1, hydrated BMP:GM1 mixtures spontaneously form small spherical vesicles with diameters ∼100 nm and a narrow size distribution profile. For other concentrations of GM1, hydrated dispersions with BMP have non-spherical shapes and heterogeneous size profiles, with average vesicle diameters >400 nm. All samples were prepared at pH 5.5 to mimic the lumen acidity of the late endosome where BMP is an essential component of intraendosomal vesicle budding, lipid sorting and trafficking. These findings indicate that GM1 and BMP under a limited concentration range spontaneously form small vesicles of homogeneous size in an energy independent manner without the need of protein templating. Because BMP is essential for intraendosomal vesicle formation, these results imply that lipid–lipid interactions may play a critical role in the endosomal process of lipid sorting and trafficking.
The effect of nerve growth factor on dispersed neuronal hela heterokaryons.

Abstract Dorsal root ganglia from 7-day chick embryos were minced and slowly trypsinized to produce a suspension of cells. This suspension was centrifuged in an albumin density gradient and the fraction enriched with neuronal perikarya collected. This fraction was combined with an equivalent number of HeLa cells. The two cell types are easily identifiable with interference microscopy. The two cell types were fused by the addition of β-propiolactone-inactivated Sendai virus. The resultant heterokaryons were cultured in modified hanging drop preparations in the presence of nerve growth factor and supplemented medium. Nerve growth factor stimulated the growth of long processes from the neuronal-HeLa heterokaryons when added to both long- and short-term cultures thereby demonstrating retention by the heterokaryon of a differentiated property of the neuron. We conclude that differentiated properties can be retained in somatic cell hybrids.
Studies on Na+-K+-activated adenosine triphosphatase. XVI. Its absence from the cation transport system of Ulva lactuca.

Abstract 1. 1. The ouabain-sensitive Na+K+-activated adenosine triphosphatase, which is closely related to, or identical with the active Na+K+ transport system, occurs with a great variety of animal species and tissues. 2. 2. The cation transport system of the marine green alga Ulva lactuca, the common “sea lettuce”, has a K+ influx 3.5 times as large as the Na+ efflux in darkness and upon illumination the K+ influx increases sharply without change in Na+ efflux. 3. 3. Enzyme assay showed that Ulva lactuca lacks an ouabain-sensitive Na+K+-activated adenosine triphosphatase system. 4. 4. The absence of an ouabain-sensitive cation transport system was concluded from the lack of effect of incubation in 10−4 M ouabain upon the Na+ and K+ levels of the tissue and upon the 86Rb+ uptake rate. 5. 5. Although the exact limits to the occurrence of Na+K+-activated adenosine triphosphatase and ouabain-sensitive cation transport are not yet known, the correlation between these two is so far unbroken.
Photometric determination of gallium with rhodamine b

Abstract Gallium is extractable as rhodamine B chlorogallate with benzene from 6 M hydrochloric acid, and can be determined absorptiometrically or fluorimetrically in the extract. The interference of iron(III) is avoided by first separating gallium by extraction with isopropyl ether from hydrochloric acid solution containing titanous chloride. Traces of gallium can be determined in the presence of aluminium, indium, zinc, antimony, thallium, tungsten and other elements.
Earthworm community structure and diversity in experimental agricultural watersheds in Northeastern Ohio

Earthworms are known to have an important impact on soil fertility but much remains to be known about the factors that influence earthworm abundance and species diversity in agricultural soils and the impact of earthworm diversity on soil processes in those soils. We have studied factors that influence earthworm community structure and biodiversity in experimental agricultural watersheds at the North Appalachian Experimental Watershed near Coshocton, Ohio. We sampled earthworm communities in seven such watersheds from 1990 to 1992. Six earthworm species were present: Aporrectodea caliginosa, A. trapezoides, A. tuberculata, Lumbricus rubellus, Lumbricus terrestris and Octolasion tyrtaeum. The total earthworm biomass ranged from 2 to 32 g m-2 and population levels ranged from 10 to 350 worms m-2. Earthworm community structure and diversity differed among watersheds and was influenced by cropping patterns, geographic location and tillage. The greatest earthworm diversity and highest earthworm population levels occurred in a no-tillage watershed and a watershed that had previously been in ryegrass and long-term no-till. High earthworm populations were also observed in a chisel-plowed watershed. Watersheds that had been managed identically for 50 years had much different earthworm communities, indicating that factors other than management were important in determining species composition. The three watersheds with the lowest populations and diversity were adjacent to one another at one end of the station, indicating that at this site geographic location had the predominant influence on earthworm communities. A severe drought in 1991 greatly reduced earthworm populations and biomass. However, earthworm species differed in their response to drought with Lumbricus rubellus appearing to be the most drought-sensitive and Aporrectodea spp. the most drought-tolerant.
Grade Retention among Students with Learning Disabilities.

This study explored the rates of grade retention among children with undiagnosed learning disabilities. During the 1990–91 school year, data were collected on 344 Michigan students who were referred for special-education evaluation due to learning problems. Of the 201 students determined to possess a learning disability (LD), 71.6% had been retained at least once before they were referred for special-education evaluation. Minority and urban LD students were more apt to be retained before being referred for evaluation. Retained LD students were usually one year older than nonretained LD students at the time of special-education referral. Although retention among LD students did not appear to be related to gender or grade placement, retained LD students generally exhibited lower levels of intelligence and weaker skills in reading comprehension, writing, and math at the time of their referral. © 1996 John Wiley & Sons, Inc.
Zonal techniques for flowfield simulation about aircraft

A technique for performing conservative flowfield calculations on zonal meshes is described. The underlying flow solver is an implicit, upwind finite volume scheme which can incorporate either a perfect gas or an equilibrium air equation of state. Two different approaches which yield identical results, in terms of performing a conservative flux calculation on a zonal interface, are described and compared in terms of numerical efficiency. The capability of the method to handle relatively complex geometries is demonstrated by considering the flowfield about a model SR71 aircraft.
The essential amino acid requirements of the Dungeness crab, Cancer magister

Abstract The essential amino acid requirements for juveniles of the Dungeness crab Cancer magister were determined by the radiometric method. Both the protein and free amino acids were quantified and their specific activities compared. Injection of five crabs with [U- 14 C] glucose resulted in the labelling of the amino acids cysteine, aspartate, serine, glutamate, proline, alanine, and glycine. One crab injected with [U- 14 C] glutamate showed results similar to the glucose-injected crabs, with the notable exception that proline did not become labelled. An animal injected with [U- 14 C] phenylalanine produced radioactive tyrosine, alanine, and glutamate. Since fumarate is one of the breakdown products of phenylalanine in those species that have been studied, the lack of labelled aspartate is of interest. These results suggest that cysteine, aspartate, serine, glutamate, alanine, proline, and glycine are dispensable and that tyrosine is dispensable if phenylalanine is supplied. The non-labelled amino acids threonine, valine, methionine, isoleucine, leucine, phenylalanine, tryptophan, lysine, histidine, and arginine are inferred to be essential.
Constipation: Linaclotide--a stimulating new drug for chronic constipation.

Few effective treatments for the common disorder of chronic constipation are currently available. Linaclotide, a guanylate cyclase C receptor agonist, has shown promising efficacy as a treatment for chronic constipation in a phase IIb, double-blinded, placebo-controlled, dose-ranging trial. This new therapy could potentially improve symptoms, such as bloating and discomfort, as well as bowel habits for patients with chronic constipation.
Ultrasound elastography: liver

Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.
Endothelium-dependent relaxation and hyperpolarization evoked by bradykinin in canine coronary arteries : enhancement by exercise-training

1. Kinins, which are produced locally in arterial walls, stimulate the release of endothelium-derived vasodilator substances. Therefore, they may participate in the metabolic adaptation to chronic exercise that occurs in the coronary circulation. Experiments were designed to compare the reactivity to bradykinin in coronary arteries isolated from sedentary and exercised-trained dogs (for 8-10 weeks). 2. The organ chambers used in this study were designed for measurement of isometric tension and cell membrane potential with glass microelectrodes. Rings of canine isolated coronary arteries with endothelium were suspended in the organ chambers filled with modified Krebs-Ringer bicarbonate solution (37 degrees C, gassed with 5% CO2 in 95 O2), and were all treated with indomethacin to prevent interference from prostaglandins. 3. Bradykinin evoked concentration-dependent relaxations of the coronary arteries. However, the kinin was significantly less potent in relaxing coronary arteries from the sedentary dogs than those from the trained ones. 4. In the presence of NG-nitro-L-arginine (an inhibitor of nitric oxide synthases), concentration-relaxation curves to bradykinin were shifted to the right in both types of preparations. Nonetheless, the peptide was still significantly more potent in arteries from exercise-trained animals. 5. In the electrophysiological experiments, concentration-hyperpolarization curves to bradykinin obtained in arteries from sedentary dogs were also significantly to the right of those in vessels from exercise-trained animals. Thus, in arteries from exercised animals, bradykinin more potently evoked the release of both nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). 7. The angiotensin converting enzyme (ACE)-inhibitor, perindoprilat, shifted to the left the concentration-relaxation curves to bradykinin obtained under control conditions and in the presence of NG-nitro-L-arginine. The concentration-hyperpolarization curves to bradykinin were also shifted to the left by perindoprilat. The shift induced by the ACE-inhibitor in either type of preparation was not significantly different. 8. These findings demonstrate that exercise-training augments the sensitivity of the coronary artery of the dog to the endothelium-dependent effects of bradykinin. This sensitization to bradykinin may reflect an increased role of both NO and EDHF, and is not the consequence of differences in ACE activity in the receptor compartment.
Normal modes for predicting protein motions: A comprehensive database assessment and associated Web tool

We carry out an extensive statistical study of the applicability of normal modes to the prediction of mobile regions in proteins. In particular, we assess the degree to which the observed motions found in a comprehensive data set of 377 nonredundant motions can be modeled by a single normal-mode vibration. We describe each motion in our data set by vectors connecting corresponding atoms in two crystallographically known conformations. We then measure the geometric overlap of these motion vectors with the displacement vectors of the lowest-frequency mode, for one of the conformations. Our study suggests that the lowest mode contains useful information about the parts of a protein that move most (i.e., have the largest amplitudes) and about the direction of this movement. Based on our findings, we developed a Web tool for motion prediction (available from http://molmovdb.org/nma) and apply it here to four representative motions—from bacteriorhodopsin, calmodulin, insulin, and T7 RNA polymerase.
Parasite local adaptation: Red Queen versus Suicide King

Parasites are generally expected to be locally adapted to their hosts, but the basis of this prediction involves two distinct areas of research: coevolutionary studies of infectivity and epidemiological studies of optimal virulence. The distinction between infectivity and virulence is sometimes blurred but is crucial to our understanding of parasite local adaptation. Recent theoretical and empirical work has greatly improved our understanding of the evolutionary processes affecting local infectivity adaptation. However, in spite of the attention paid to the evolution of virulence, only a few recent models have explicitly studied spatial variation in optimal virulence. Our understanding of parasite local adaptation will continue to improve through studies of the genetic basis of infectivity, research on spatial variation in optimal virulence in multiple-deme systems, and the combination of these two interacting components of parasite infection in theoretical and empirical studies.
Applications of transcranial magnetic stimulation

Over the past decade research and clinical applications of transcranial magnetic stimulation (TMS) have expanded greatly. These advances have depended on improvements in technology, in the models used to understand TMS biophysics, and in our understanding of TMS neurophysiology. Single-pulse TMS has been used extensively in studying motor and visual systems. Rapid, repetitive TMS (rTMS) has more powerful effects on cognitive function including speech, attention, and memory, but introduces the risk of provoking epileptic seizures in normal subjects. The paper reviews recent progress in TMS.
Responses of mosquitoes and German cockroaches to ultrasound emitted from a random ultrasonic generating device

The repellency of ultrasound to females of two species of mosquitoes, Anopheles quadrimaculatus Say and Anopheles gambiae Giles (Diptera: Culicidae), and male and female German cockroaches, Blattella germanica (L.) (Blattodea: Blattellidae), was evaluated under laboratory conditions using a random ultrasonic device developed at Kansas State University. This device produces ultrasound in the 20‐ 100 kHz frequency range and random sound patterns at any frequency range. Under the particular settings described in the paper, this ultrasonic device produced sound pressure levels from 91 to 101, 91 to 102, and 90 to 100 dB at the top, bottom, and side panels of the test chamber, respectively (0 dB = 20 micropascals). Sound pressure levels recorded at the center of the top, bottom, and side panels were higher than those recorded at the panel edges. Ultrasound from the random ultrasonic device failed to repel mosquitoes and German cockroaches at the different frequency ranges evaluated. Our results confirm previous findings with commercial devices producing constant sound patterns that ultrasound in general is not a promising tool for repelling mosquitoes and cockroaches.
Visual methods for determining ambient illumination conditions when viewing medical images in mobile display devices

— The quality of the displayed image on mobile devices is affected by the varying ambient illumination conditions. Determining appropriate viewing conditions for particular visual tasks requires time and the appropriate instrumentation. To this end, the usefulness of more practical visual tests for use in clinical environments were explored. Experiments to determine the limitations of mobile displays in terms of the visibility of subtle targets for different background luminance and ambient illumination with two mobile devices were conducted. A noise-embedded text detection task and a threshold estimation staircase technique for a range of illuminance between 1 and 80,000 lx encompassing conditions found in dark reading rooms, office spaces, and outdoor scenarios has been compared. It was found that the text detection method holds promise as a surrogate for more complicated tests in the framework of a clinically practical implementation.
Resistance to thyroid hormone and its molecular basis

Generalized resistance to thyroid hormone (GRTH) is an inherited syndrome characterized by hyposensitivity of target tissues to thyroid hormone. The clinical presentation is variable. The syndrome is usually suspected when elevated serum thyroid hormone levels are associated with a non-suppressed thyroid-stimulating hormone (TSH). While goiter and thyroid test abnormalities have more often led to the suspicion of thyroid gland dysfunction, short stature, hyperactivity, learning disability and goiter in children or adolescents and recalcitrant goiter in adults, should raise the suspicion of GRTH. Hypothyroidism has been considered when growth or mental retardation was the presenting symptom and thyrotoxicosis when confronted with attention deficit, hyperactivity or tachycardia. Failure to recognize the inappropriate persistence of TSH secretion in spite of elevated thyroid hormone levels has commonly resulted in erroneous diagnosis leading to antithyroid treatment. More than 300 subjects with this syndrome have been identified. The mode of inheritance in the majority of families is autosomal dominant. Recessive transmission has been found in only one family. It has long been speculated that this defect is likely to be caused by an abnormal thyroid hormone receptor (TR), but this hypothesis could not be directly tested until the isolation of two TR genes, TR alpha and TR beta. Mutations in the TR beta gene have been identified in 42 families with GRTH. All are located in the T3-binding domain straddling the putative dimerization region and exhibit various degrees of hormone-binding impairment. This finding, and the fact that heterozygous subjects with complete TR deletion are not affected while those with point mutations are, indicates that interactions of a mutant TR with normal TR and with other factors are responsible for the dominant inheritance of GRTH and its heterogeneity. Elucidation of the etiology of GRTH has not only added a new means for the early diagnosis of the syndrome but provided new insights in the understanding of the mechanism of hormone action.
Performance Analysis of Regular Low-Density Generator-Matrix Codes Under Majority-Rule Based Iterative Decoding Algorithm

Low-density generator-matrix (LDGM) codes are of particular interest not only because of their satisfying performance while maintaining low encoding complexity, but also because of promising applications such as network coding in cooperative multiple-access networks and joint source-channel coding where the LDGM codes are suitable. We investigate the performance of regular LDGM codes under the majority-rule based (MB) iterative decoding algorithm. The threshold and error-floor behaviors of the code can be extracted. A lower-bound expression for the error floors is obtained. The optimal majority weight for the MB decoding algorithm to achieve the lowest error floor is found.
Identifying Addressable Impediments to Student Learning in an Introductory Statistics Course

Using performance data on a common test instrument administered to more than 4,000 business statistics students studying under 16 different instructors over a period of 6.5 years, we identify areas of consistent student weakness. In addition to verifying difficulties found by earlier researchers, we document a fundamental problem in students' ability to reason with cumulative probabilities, a problem with implications for solving problems with both discrete and continuous distributions. Our performance data also suggest that it may be useful to view statistics problems using a taxonomy based more on solution procedure than on traditional statistics topics. We employ a new methodology based on cluster analysis to identify areas where the observed student difficulties may be particularly addressable. Finally, we offer some preliminary findings on how these problems may be addressed with practical teaching suggestions based on the approaches employed by our more successful instructors.
Re-examine the two principles of special relativity and the Sagnac effect using GPS' range measurement equation

Successful GPS operations are based on a basic equation: the range measurement equation, |r/sub r/(t/sub r/)-r/sub s/(t/sub s/)|=c(t/sub r/-t/sub s/), in an Earth-centered inertial system. The calculations based this equation show that the correctness of the equation leads to the incorrectness of the two principles of special relativity, the principle of the constancy of the speed of light and the principle of relativity. Moreover, the Sagnac (1913) effect can be fully interpreted by this equation and therefore, the Sagnac effect is a non-relativistic effect. It is indicated that the relativity of simultaneity of special relativity contradicts the basic operational principle of GPS. Furthermore, based on the range measurement equation, it is expected that a practical and crucial experiment that does not require any clock synchronization will give a result contradicting the two principles of special relativity. The crucial experiment can be further simplified by using GPS. We should conduct the crucial experiment, and re-examine and reconstruct special relativity starting from its foundations.
IC-processed micro-motors: design, technology, and testing

Micromotors having rotors with diameters between 60 and 120 mu m have been fabricated and driven electrostatically to continuous rotation. These motors were built using processes derived from IC (integrated circuit) microcircuit fabrication techniques. Initial tests on the motors show that friction plays a dominant role in their dynamic behavior. Observed rotational speeds have thus far been limited to several hundred r.p.m., which is a small fraction of what would be achievable if only natural frequency were to limit the response. Experimental starting voltages are at least an order of magnitude larger than had been expected (60 V at minimum and above 100 V for some structures). Observations of asynchronous as well as synchronous rotation between the driving fields and the rotors can be explained in terms of the torque/rotor-angle characteristics for the motors. >
Socioeconomic Status and Mortality Contribution of health care access and psychological distress among U.S. adults with diagnosed diabetes

OBJECTIVE Although several studies have examined the association between socioeconomic status (SES) and mortality in the general population, few have investigated this relationship among people with diabetes. This study sought to determine how risk of mortality associated with measures of SES among adults with diagnosed diabetes is mitigated by association with demographics, comorbidities, diabetes treatment, psychological distress, or health care access and utilization. RESEARCH DESIGN AND METHODS The study included 6,177 adults aged 25 years or older with diagnosed diabetes who participated in the National Health Interview Surveys (1997–2003) linked to mortality data (follow-up through 2006). SES was measured by education attained, financial wealth (either stocks/dividends or home ownership), and income-to-poverty ratio. RESULTS In unadjusted analysis, risk of death was significantly greater for people with lower levels of education and income-to-poverty ratio than for those at the highest levels. After adjusting for demographics, comorbidities, diabetes treatment and duration, health care access, and psychological distress variables, the association with greater risk of death remained significant only for people with the lowest level of education (relative hazard 1.52 [95% CI 1.04–2.23]). After multivariate adjustment, the risk of death was significantly greater for people without certain measures of financial wealth (e.g., stocks, home ownership) (1.56 [1.07–2.27]) than for those with them. CONCLUSIONS The findings suggest that after adjustments for demographics, health care access, and psychological distress, the level of education attained and financial wealth remain strong predictors of mortality risk among adults with diabetes.