cssi/SciSciGPT-SciSciNet huggingface dataset:
Autoimmune CD4+ T cells interfere with immune tolerance to a thymic-independent antigen

The ability of autoimmune T cell subsets to interfere with tolerization of B cells can be studied by using thymic-independent Ag. We have defined an abnormality within the CD4+ T cell compartment in young NZB and MRL-lpr/lpr mice by studying tolerance of spleen and B cells to the thymic independent Ag, fluorescein-Brucella abortus. Tolerization of spleen cells is defective in MRL-lpr/lpr mice, but not MRL-+/+ or C3H.lpr mice, suggesting that the defect requires both the autosomal MRL background and the lpr gene to be present. T enriched cells from NZB mice and from MRL-lpr/lpr mice (but not MRL-+/+ or C3H.lpr mice) reverse tolerance in spleen cells from [NZB X DBA/2]F1 and C3H/HeJ mice, respectively. This interference is removed by treatment with anti-CD4 antibody and C. Supernatants from cultured T cells of NZB and MRL-lpr/lpr mice also prevent tolerance in spleen cells of [NZB X DBA/2]F1 and MRL-+/+ mice, respectively, unless CD4+ cells are removed prior to T cell culture. Removal of T cells from NZB and MRL-lpr/lpr spleen cells allows normal tolerization of B cells, which is abrogated by the addition of syngeneic T cells or cultured T cell supernatants. This effect also depends on the presence of CD4+ T cells. These studies show that in MRL-lpr/lpr mice, through interaction of the lpr and MRL background genes in a T cell subset, and in NZB mice, CD4+ T cells interfere with B cell tolerance to a thymic-independent Ag.
Regression of Feline Sarcoma Virus-Induced Sarcomas in Dogs. I. Morphologic Investigations

In a study of morphologic changes in the development and regression of feline sarcoma virus (FeSV)-induced tumors in dogs, 27 weaned and newborn beagle and mongrel puppies were inoculated with FeSV in doses from 1.0 to 3.0 gEq; 2 beagle and 2 mongrel puppies were used as uninoculated contact controls. All animals were examined daily, and crude tumor volume was calculated from length, width, and depth measurements of the neoplasms. Biopsies were done at various stages of tumor development and regression. When tumors were no longer palpable, all puppies were necropsied. Two of 8 (25%) weaned beagle puppies, 10 of 12 (83%) newborn beagles, and 1 of 7 (14%) newborn mongrels developed tumors, all histologically confirmed fibrosarcomas. No metastatic tumor foci were detected. The tumor life-span was divided into approximately equal periods of growth and regression. The initial regression period was characterized by focal necrosis and accompanying neutrophil infiltration. The later stages of regression were characterized by lymphocytic or mixed mononuclear infiltrates. Thus the regression histopathology was not uniform and suggested that different immunologic mediation systems effect regression. Nonneoplastic morphologic changes consisted largely of lymphoid depletion and necrosis in lymph nodes and thymus after inoculation.
Clinical Considerations Concerning Detection of Venous Air Embolism

Venous air embolism during neurosurgical procedures (detected by Doppler Ultrasound and aspiration via a right atrial catheter) was noted in 100 of 400 patients in the sitting position, 5 of 60 patients in the lateral position, 7 of 48 patients in the supine position, and 1 of 10 individuals monitored in the prone position. We confirmed venous air embolism in many of these cases by using serial technetium-macroaggregated albumin lung scans. Gravitational gradients from the venous portal of entrance to the right side of the heart were as small as 5.0 cm, with aspiration of 200 ml of air occurring. Doppler ultrasonic air bubble detection and aspiration through a previously inserted right atrial catheter are critical factors in the diagnosis and treatment of this condition.
Climbing Darwin's ladder.

The work of Bartel and Szostak, in which RNA molecules were selected to enhance the ability to catalyze a reaction similar to a step in protein-catalyzed RNA replication, is discussed. An important aspect of this experiment was the ability to reach a high level of functional organization in ten evolutionary steps. Further steps necessary to obtain an RNA enzyme with RNA replicase activity include performing the reaction with mononucleoside 5'-triphosphates, generalizing the reaction to include a variety of sequences without loss of template-dependent specificity, and overcoming template self-structure that could prevent some regions from being copied efficiently.
Resistance artery vasodilation to magnesium sulfate during pregnancy and the postpartum state

This study compared the vasodilatory responses to magnesium sulfate (MgSO4) of cerebral and mesenteric resistance arteries and determined whether the responses varied between different gestational ...
Cases of spontaneous tumor regression in hepatobiliary cancers: implications for immunotherapy?

Hepatobiliary cancers, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (CCA), together comprise the fifth most common cancer and third leading cause of cancer death globally [1]. The majority of patients present with advanced, unresectable disease, with median survival less than a year [2–4]. Immune dysregulation may contribute to hepatobiliary carcinogenesis, though mechanisms are not well understood [5–7]. Immunotherapy approaches in oncology may be most efficacious in cancers susceptible to intrinsic immune modulation [8, 9]. Recently, increasing understanding of tumor immunogenicity spurred the development of novel classes of immunetargeted therapies, including inhibition of co-stimulatory pathways mediated by cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and the programmed death-1 (PD-1) receptor and its ligand (PD-L1). In a phase II trial in hepatitis C virus (HCV)-associated advanced HCC patients , tremelimumab-mediated CTLA-4 inhibition demonstrated a promising antitumor activity, accompanied by intriguing antiviral responses [10]. Table 1 displays selected ongoing HCC immunotherapy clinical trials. We present three cases of spontaneous regression of advanced hepatobiliary cancers in patients with HCV cirrhosis, one in a patient with mixed HCC and CCA tumor histology and two in patients with HCC. Our aims are to highlight the potential activity of native antitumor immune mechanisms against these malignancies and explore the implications for emerging immunotherapies in this grim family of cancers refractory to conventional therapies.
The Design of a Training Program for Adolescent Medicine Thoughts of Fellows in Training

Program design for training in Adolescent Medicine is still in an evolution ary state. Postgraduate fellows and program directors have different percep tions with regard to the importance of various components of the ideal training program. Fellows indicate a higher priority for problems associated with the female reproductive system than do their mentors. Inpatient experience received lesser emphasis by the Fellows. Adolescent Medicine as a subspecialty discipline is discouraged.
Evolution of a colour pattern: history, development, and selection

Patterns of melanin pigmentation in birds are extremely varied. Nevertheless it is easy to think of many patterns that are never observed, and others that frequently recur in diverse and distantly related species. Using as our model the avian genus Phylloscopus we ask how the restricted range of observed patterns might be attributable to a restricted range of variants produced by developmental perturbations. The patterns we consider consist of unmelanized patches on the wings, crown and rump on otherwise pigmented upperparts. We use reaction-diffusion models to show that gross features of the pattern can be simply predicted from considerations of embryo shape. We suggest that birds are expected to have more patterned heads, because the head region is relatively larger than other regions in the developing embryo. A comparative analysis across many species of birds and a phylogenetic analysis within the genus Phylloscopus show that the component elements of the pattern have repeatedly been lost and gained during evolution. A shift in a threshold reading could explain the appearance and disappearance of the unmelanized patches, perhaps through changes in the sensitivity of melanocytes to epidermal signals. Such threshold shifts would make the transition between patterned and unpatterned forms particularly easy once the patterns have been exposed to selection in some distant ancestor. This partitioning of the roles of selection and development implies that many features of the patterns reflect developmental mechanisms in both immediate and more distant ancestors.
Headspace analysis of Italian and New Zealand parmesan cheeses.

: New Zealand is a leader in the global dairy industry. Milk powder is the principal export product, but there is also a prominent cheese manufacturing industry, catering more for the domestic market. The Selected Ion Flow Tube-Mass Spectrometric (SIFT-MS) technique was used to compare 4 New Zealand cheeses marketed as “parmesan” with 4 Italian Parmigiano Reggiano and Grana Padano cheeses. The cheese headspace was analyzed in real time without any sample preconcentration. Total of 38 volatile compounds in the cheese headspace were monitored with headspace concentrations varying between single digit parts per billion (ppb) to tens of parts per million (ppm). When the results were subjected to multivariate statistical analysis, a clear discrimination was found between the New Zealand “parmesan” and Italian cheeses based solely on the measured concentrations of these volatile compounds. If the volatile compounds used in the analyses were restricted to known odor-active compounds in Parmigiano Reggiano cheese, the ability to discriminate between the cheeses was maintained. The analyses also showed that it was possible to clearly differentiate between the different processing plants in individual countries. Important discriminatory volatiles in the samples tested were butanoic acid and phenylacetaldehyde for discriminating between Italian cheeses and ethyl butyrate, acetaldehyde and methylbutanals between New Zealand cheeses. We conclude that the New Zealand “parmesans” do not provide a good representation of the aroma of Italian “parmesans.” Practical Application: SIFT-MS has been shown to clearly differentiate both country of origin and the manufacturer of “parmesan” cheeses made in Italy and New Zealand based on differences in volatile organic compounds. Thus this method will have benefit for use in the quality control of “parmesan” and other cheese varieties.
Spontaneous cerebellar hemorrhage in a patient taking apixaban

Abstract Objectives Atrial fibrillation is closely associated with cardioembolic stroke. Until recently, warfarin has been the gold standard for the treatment of atrial fibrillation. Since 2010 the United States Food and Drug Administration has approved three new agents for anticoagulation in patients with atrial fibrillation. The purpose of this case report is to discuss some of the practical implications for using these agents. Methods A patient taking apixaban presented with a spontaneous cerebellar hemorrhage. While the patient was initially considered a candidate for surgical intervention, the lack of literature addressing surgical intervention in patients on novel anticoagulation clouded the clinical decision-making. The patient was ultimately managed with administration of activated prothrombin complex concentrate, blood pressure control, frequent clinical assessments and airway protection. The patient did not undergo craniotomy for hematoma evacuation. Conclusions Recent FDA approval of several novel oral anticoagulants for use in patients with atrial fibrillation has resulted in a significant number of patients formerly treated with warfarin being switched to these newer agents. There remains a lack of clear guidelines for the management of hemorrhagic complications. This case report describes one management strategy and highlights the paucity of current evidence to support critical clinical decisions.
Bi-Helix SWS for High-Power TWTs

We have studied the electromagnetic properties of bi-helix slow-wave structures (SWSs) with added azimuthal conductors in the form of: 1) metal rings connecting the helices and 2) an azimuthally conducting screen formed by metal rings with and without capacitive gaps. We show that these added azimuthal conductors suppress backward-wave oscillation and enable stable high-voltage, high-power operation of traveling-wave tubes (TWTs). Prototype circuits were fabricated and the dependence of phase velocities of the in-phase (fundamental) and opposite-phase (BWO) modes on frequency and on the geometrical parameters of the rings were measured and analyzed. Novel, easily fabricated designs of bi-helix SWSs with circular metallization on diaphragm supports are proposed. These practical designs will make it possible to increase the maximum stable operating voltage of wideband TWTs to 30–40 kV, with a corresponding increase in output power without the danger of BWO.
Nanostructured Materials by Machining

Large strain deformation, a key parameter in microstructure refinement by Severe Plastic Deformation (SPD) processes, is a common feature of chip formation in machining. It is shown that the imposition of large plastic strains by chip formation can create metals and alloys with nanocrystalline or ultra-fine grained microstructures. The formation of such nanostructured materials is demonstrated in a wide variety of material systems including pure metals, light-weight aluminum alloys, and high strength steels and alloys. Nanocrystalline microstructures with different morphologies are demonstrated. The hardness and strength of the nanostructured chips are significantly greater than that of the bulk material. The production of nanostructured chips by machining, when combined with comminution and powder processing methods, may be expected to lead to the creation of a number of advanced materials with new and interesting combinations of properties. These materials are expected to find wide-ranging applications in the discrete products sector encompassing ground transportation, aerospace and bio-medical industries.Copyright © 2005 by ASME
A spindle-like apparatus guides bacterial chromosome segregation

In bacteria, chromosomes are partitioned by the Par system. Super-resolution microscopy demonstrates that ParA and ParB forms a 'spindle-like' structure and suggests that the pole protein, TipN, anchors the DNA-bound ParA filaments at the new pole.
A translocatable cold hardiness promoter.

Hardy woody species which cold acclimate late or slowly are often injured by early autumn frosts. Adapted hardy species characteristically stop growing and acclimate to some extent prior to autumn frosts. In nature this first stage of acclimation appears to be induced by shortening photoperiods in a number of woody species (4, 23, 24). Because growth cessation is associated with cold acclimation in woody plants, a considerable amount of work has been done to determine whether growth retarding chemicals can induce cold acclimation in the absence of inductive photoperiods. The growth retardants tested have been found to have only slight and often inconsistent effects on hardiness (7, 8, 13, 15). Such findings have stimulated interest in elucidating the effective endogenous system(s) which induce acclimation in hardy species (7, 8). Several researchers have recently reported that short-day-induced leaves are the source of translocatable hardiness promoting factor(s) (4, 5, 10). The existence of such a factor(s) is of practical interest because it (they) may prove to be a relatively simple compound(s) which could be applied exogenously to induce acclimation in the absence of inductive environmental stimuli. There is, as yet, no evidence to indicate whether or not the promoting factor(s) is genotype specific. A considerable amount of research has been done on the environmental control of cold acclimation (1, 4, 10, 24), the natural patterns of acclimation (4, 22), and the metabolic changes associated with acclimation (14) in red-osier dogwood (Cornus stolonifera Michx.). In nature, acclimation usually proceeds in two distinct stages which appear to be induced by short days and low temperatures (4, 21, 22), respectively. Climatic races collected from various sites in North America were found to differ greatly in the timing and rate of cold acclimation when they were grown in a uniform environment field plot in Minnesota (18). In the field at St. Paul, Minnesota (45° North latitude), a clone from Dickinson, North Dakota (47° North latitude), was found to begin cold acclimating as much as 8 weeks earlier in the autumn than a clone from Seattle, Washington (47° North latitude) (20). Both races eventually acclimate to below -196 C, but the Seattle race is often injured severely by the first frost in the autumn at St. Paul. The influence of gibberellic acid and abscisic acid on cold acclimation has been studied in the hardy tree, Acer negundo (8). Based on these results, Irving has suggested that abscisic acid may be the hardiness promoting factor (6).
Introducing Flow Theory to Explain the Interactive Online Shopping Experience in a Travel Context

Online travel commerce has evolved significantly from the initial sales of less-complex products such as airline tickets, accommodations, and car rentals, to include more complex products like vacation packages and cruises. Many online travel portals, however, have fallen behind in terms of creating a compelling online environment for customers. Online shopping behavior is becoming increasingly complex with the evolution of experiential and utilitarian shopping practices. These two types of practices have a significant effect on the formation of a customer's attitude towards a Web site and eventual purchase intention. The proposed model delineates the customer's preference towards a Web site within experiential and utilitarian purchase contexts when flow variables control, cognitive enjoyment, and focus are involved. This article may help online travel businesses identify unique Web features that satisfy the needs of both the experiential and utilitarian customer. Moreover, this model shows that a success...
Temperature Dependence of Electron Spin Relaxation of 2,2-Diphenyl-1-Picrylhydrazyl in Polystyrene

The electron spin relaxation rates for the stable radical DPPH (2,2-diphenyl-1-picrylhydrazyl) doped into polystyrene were studied by inversion recovery and electron spin echo at X-band and Q-band between 20 and 295 K. At low concentration (340 μM, 0.01%) spin-lattice relaxation was dominated by the Raman process and a local mode. At high concentration (140 mM, 5%) relaxation is orders of magnitude faster than at the lower concentration, and 1/T1 is approximately linearly dependent on temperature. Spin lattice relaxation rates are similar at X-band and Q-band. The temperature dependence of spin echo dephasing was faster at about 140 K than at higher or lower temperatures, which is attributed to a wagging motion of the phenyl groups.
Maternal and Fetal Responses to Halothane in Pregnant Monkeys

Maternal cardiac output, blood pressure, heart rate, fetal blood pressure, heart rate and respiratory blood gases, and uterine blood flow were measured in six pregnant monkeys during halothane–nitrous oxide and oxygen anesthesia and compared to these same parameters observed during nitrous oxide and oxygen anesthesia. Halothane 1.5% was associated with a decrease in maternal arterial pressure (54%), heart rate (10%), cardiac output (17%), total peripheral resistance (40%), and uterine blood flow (28%). Mean fetal heart rate decreased 18% and mean fetal blood pressure 22%. These changes in fetal hemodynamics were probably related to a direct depression of the fetal cardiovascular system and its usual compensatory mechanism as well as the fetal asphyxia secondary to the decrease in uterine blood flow. ZUSAMMENFASSUNG Mutterliches Herz-Minuten-Volumen, Blutdruck, Pulsfrequenz, fetaler Blutdruck, Herzfrequenz und respiratorische Blutgase und uterine Durchblutung wurden bei 6 schwangeren Affen unter Halothan-Lachgas und Sauerstoffnarkose gemessen und mit Lachgas-Sauerstoff anaesthesierten Tieren vergleichen. Halothan 1,5%ig war begleitet von einer Abnahme des mutterlichen arteriellen Druckes (54%) der Pulsfrequenz (10%) des Herz-Minuten-Volumen (17%) des peripheren Gesamtwiderstandes (40%) und der uterinen Durchblutung (28%). Die mittlere fetale Herzfrequenz nahm um 18% ab und der fetale Blutdruck um 22%. Diese Veranderungen der fetalen Haemodynamik entsprechen wahrscheinlich einer direkten Depression des fetalen Herz-Kreislaufsystems und seines normalen Kompensationsmechanismus sowie der fetalen Asphyxie bedingt durch die Reduktion der uterinen Durch blutung.
Frequent hemodialysis with NxStage™ system in pediatric patients receiving maintenance hemodialysis

Recent evidence from adult hemodialysis (HD) patient studies reveal improved biochemical control and reported health-related quality of life after transition from conventional thrice weekly to daily home maintenance HD treatment. Published pediatric frequent dialysis experiences demonstrate similar improvement but all used conventional HD machines, which employ a treated municipal water supply, thereby frequently exposing patients to proinflammatory components. We report our pediatric experience with six-times-weekly HD using the NxStage™ system, which uses sterile dialysis fluid to provide dialysis in the home or center setting. Four patients (weight range 38–61.4 kg) completed the 16-week study. Patients exhibited progressive reductions in casual pretreatment systolic and diastolic blood pressures, discontinuation of antihypertensive medications, and decreased blood pressure load by ambulatory blood pressure monitoring. Mean serum phosphorus improved without change in phosphorus binder medication, and all three patients with a normalized protein catabolic rate 1.1 g/kg per day. Patients reported no adverse effects. Variable changes in proinflammatory cytokine levels were observed. We suggest that frequent HD with the NxStage™ system be considered for children who would benefit from home-based maintenance dialysis.
Vmax as an index of contractile state in man.

The maximal, no-load, velocity for the contractile element (V max ) was estimated in 45 patients. The patients included: 17 with normal left ventricular dynamics; eight with volume overload, compensated; 11 with volume overload, decompensated; three with pressure overload; and six with cardiomyopathy. Contractile element velocity (V CE ) during isovolumic contraction was estimated in two ways: (1) from left ventricular pressure data alone, where V CE =(1/28.8p) (dp/dt), and (2) pressure data combined with measurement of left ventricular geometry (right anterior oblique cine). V max obtained in these two ways agreed well for most patients (r = 0.82). In the normal patients, V max varied from 1.46 to 2.64 muscle lengths per sec; in contrast that of the patients with cardiomyopathy varied between 0.71 and 1.34 muscle lengths per sec. Other indices of contractility (ejection fraction, peak dp/dt, peak velocity of circumferential fiber [peak V CF ], peak V CE , and V CE at zero stress) were compared on the basis of statistical correlation and consistency of other clinical evidence (presence or absence of congestive failure). Good correlation was obtained between V max and peak V SE (r = 0.68). Ejection fraction and peak V CF were less sensitive. Neither the peak rate of pressure rise or V CE at peak stress show any significant correlation with V max or clinical state. Previous studies have shown that V max can be evaluated from pressure data alone; this study confirms this finding in patients with mitral regurgitation as well as in those with normal outflow impedance.
Auxin: Molecular genetic approaches in Arabidopsis

The plant hormone auxin is important in many plant processes. Recent results from studies on Arabidopsis have defined genes important for the regulation of auxin levels, auxin responses, and auxin transport. Mutants isolated with defects in other processes, ranging from lateral root formation to embryonic development, have also been shown to be altered in auxin pathways. Significant evidence from these studies now implicates ubiquitin-mediated regulation of the cell cycle as important in auxin response. However, much remains to be done to clarify the mechanism of auxin action, auxin transport, and the roles of auxin in plant physiology.
Systematics of the propinquus Group of Baetis Species (Ephemeroptera: Baetidae)

The Baetis propinquus, group of species is a monophyletic grouping which includes B. dardanus McDunnough (= B. elachistis Burks, NEW SYNONYM); B. longipalpus NEW SPECIES; B. ephippiatus Traver; B. frondalis McDunnough (= B. australis Traver, NEW SYNONYM); B. atrebatinus Eaton; B. tricolor Tshernova; and B. propinquus (Walsh) (= 6. spinosus McDunnough, NEW SYNONYM). The bases of nomenclatorial revisions are presented along with a key to the adult males of North America. A phylogeny for the species is theorized and a discussion of the evolution of larval and adult characters among the species and hypothetical ancestors is included.
Extraneous solutions predicted by the harmonic balance method

Abstract The harmonic balance method is commonly used to analyze the steady state periodic solutions of strongly non-linear systems. Mostly, only a few leading harmonics are used in the truncated Fourier series employed with this method. For the forced oscillations, this assumed solution can fail to uncover some periodic solutions which actually exist in the system response, and/or it may predict some extraneous solutions which have no counterpart in the actual response. It is shown that a qualitative failure of the harmonic balance method is neither restricted to a first approximation nor to the systems having an asymmetric potential well. It is also shown that the stability analysis of the predicted solutions or the residual values for the neglected higher harmonics cannot detect a qualitative failure of the harmonic balance method. In symmetry breaking and period doubling pitchfork bifurcations, some new harmonics are brought into the system response. Some of these harmonics, with relatively small amplitude, are instrumental in deciding the sub- or supercritical nature of these bifurcations. The harmonic balance method can lead to erroneous results if one or more of these small but instrumental harmonics is neglected from the assumed solution.
Medical management of patients with brain tumors

The most common medical problems in brain tumor patients include the management of seizures, peritumoral edema, medication side effects, venous thromboembolism (VTE), fatigue and cognitive dysfunction. Despite their importance, there are relatively few studies specifically addressing these issues. There is increasing evidence that brain tumor patients who have not had a seizure do not benefit from prophylactic antiepileptic medications. Patients on corticosteroids are at greater risk of Pneumocystis jerovecii pneumonia and may benefit from prophylactic therapy. There is also growing evidence suggesting that anticoagulation may be more effective than inferior vena cava IVC) filtration devices for treating VTE in brain tumor patients and the risk of hemorrhage with anticoagulation is relatively small. Low-molecular weight heparin may be more effective than coumadin. Medications such as modafinil and methylphenidate have assumed an increasing role in the treatment of fatigue, while donepezil and memantine may be helpful with memory loss.
Detection of Sewage Organic Chlorination Products That Are Resistant to Dechlorination with Sulfite

Most of the 36 billion gal of treated sewage wastewater discharged daily into the environment in the United States is disinfected via chlorination. To minimize toxicity. dechlorination with sulfite or sulfur dioxide is often performed. Although dechlorination is considered instantaneous and complete, several studies have found residual toxicity of chlorinated/dechlorinated effluent to aquatic life. The authors investigated chlorination/dechlorination of the organic nitrogen components of sewage wastewater using both iodometric titration and a novel LC method. For LC, a postcolumn reaction with iodide rendered submicromolar chloramine concentrations detectable with amperometry. Using a gradient-elution LC separation, the retention and dechlorination behavior of a suite of model amines was determined, representing primary and secondary aliphatic, peptide, and protein-N. Chlorination/dechlorination experiments on freshly collected, tertiary-treated wastewater showed a fraction of the organic N-chloramines are dechlorinated slowly by sulfite with half-lives of >20 min. Chromatographic retention and kinetic behavior of the sewage N-chloramines was consistent with the behavior of the model peptides and proteins. Proteolytic hydrolysis markedly increased the peptide fraction observed upon chlorination of the wastewater. These results suggest that peptides and proteins contribute to slow dechlorination of sewage and may be a factor in the toxicity noted for chlorine-disinfected wastewater.
ULTRASTRUCTURE OF THE INFECTION CYCLE OF CYANOPHAGE SM‐2 IN SYNECHOCOCCUS ELONGATUS (CYANOPHYCEAE)1

Transmission electron microscopy was used to examine the ultrastructure aspects of cyanophage SM-2 replication in its host Synechococcus elongatus Naegeli UTEX 563. Filled virion heads were observed 10 h after infection, correlating well with the 6–8 h eclipse period for the virus. As the infection cycle proceeded from 10–50 h, additional virion heads accumulated at either end of the nucleoplasm. Of the several cyanophage that lyse unicellular bluegreen algae, this is unique to the SM-2 system. The surrounding photosynthetic lamellae remained intact throughout the infection cycle. The nucleic acid composition of SM-2 was determined as DNA.
Macrocyclic diacylglycerol-bis-lactones as conformationally constrained analogues of diacylglycerol-lactones. Interactions with protein kinase C.

A series of macrocyclic diacylglycerol (DAG)-bis-lactones were investigated as extreme conformationally constrained analogues of DAG-lactones in order to seek more potent protein kinase C (PKC) ligands with higher binding affinities and less lipophilicity than previous compounds. The additional constraint achieved the desired objective as exemplified by the macrocyclic DAG-bis-lactone 57, which exhibited a 6-fold higher binding affinity for PKCα (Ki = 6.07 nM) than the corresponding nonmacrocyclic 3-alkylidene DAG-lactone 6. A structure−activity relationship (SAR) analysis of the macrocyclic DAG-bis-lactones demonstrated a parabolic relationship between activity and lipophilicity, as well as a predilection for the Z-alkylidene isomers as the preferred ligands. Molecular docking studies revealed that macrocyclic DAG-bis-lactone 57 bound to the C1b domain of PKCα exclusively in the sn-1 binding mode in contrast to DAG-lactone 6, which showed both sn-1 and sn-2 binding modes. It is proposed that the high pot...
Afterglow Spectrum of a rf Mercury Discharge

The short-duration afterglow of an rf discharge in mercury has been examined versus mercury temperature and rf power. At temperatures below 333°K all atomic lines decay exponentially and no molecular-band emission is observed. From 333° to 428°K the atomic lines initially decay, then exhibit an enchancement, and finally decay with a small decay constant. In this region again no molecular-band spectra were observed. In the temperature range from 428° and 468°K, the first molecular-band emission is observed and the intensities of the atomic lines decrease. In the temperature range between 468° and 488°K, the band spectra suddenly appear with a total intensity comparable to the atomic lines. From absorption studies, the decay of the 61P1, 63P0, 63P2 states has been studied and a theory is presented which explains the atomic emission at all temperatures up to 433°K. This theory yields an electron ambipolar diffusion coefficient of 853.1 cm2/sec and a lifetime for the 63P2 state of 46.8 μsec.
Determination of particle and gas convective heat transfer components in a circulating fluidized bed

Abstract In order to study the role of particles in augmenting heat transfer from the wall of a circulating fluidized bed (CFB), simultaneous heat and mass transfer experiments were carried out. For heat transfer, particles are important hydrodynamically, augmenting gas convection, and are a source of internal energy, i.e. particle convection. For mass transfer, only the former occurs. Simultaneous heat and mass transfer experiments using naphthalene as a sublimation material were performed in a 20 cm diameter circulating bed operating at atmospheric conditions. The presence of particles in the circulating bed causes an order of magnitude increase in the bed to wall heat transfer in comparison to single-phase turbulent gas flow. In contrast, the mass transfer is increased by 50% over single-phase gas flow. The gas convection component of the total heat transfer, found from the mass transfer experiments, varied from 10 to 20% of the total heat transfer. In this range of solids concentration between 12 and 80 kg/m 3 , particle convection dominates. The superficial gas velocity has little influence on the particle convection or on the gas convection component. The particle convection varies with the density of particles in the core, probably due to variations in the wall fraction covered by particle clusters. Gas convection is insensitive to the density of particles in the core.
Adaptive estimates of linear functionals

Given a collection of nested closed, convex symmetric sets and a linear functional, we find estimates which are within a logarithm term of being simultaneously asymptotically minimax. Moreover, these estimates can be constructed so that the loss of this logarithm term only occurs on a small subset of functions. These estimates are quasi-optimal since there do not exist estimators which do not lose a logarithm term on some part of the parameter spaces.
Reconsidering Culture-Historic Taxa in the Late Archaic:

Rigid adherence to culture histories has masked important regional variability and limited questions regarding cultural diversity and social dynamics during the Late Archaic in the Northeast. Consi...
Attention Improves Transfer of Motion Information between V1 and MT

Selective attention modulates activity within individual visual areas; however, the role of attention in mediating the transfer of information between areas is not well understood. Here, we used fMRI to assess attention-related changes in coupled BOLD activation in two key areas of human visual cortex that are involved in motion processing: V1 and MT. To examine attention-related changes in cross-area coupling, multivoxel patterns in each visual area were decomposed to estimate the trial-by-trial response amplitude in a set of direction-selective “channels.” In both V1 and MT, BOLD responses increase in direction-selective channels tuned to the attended direction of motion and decrease in channels tuned away from the attended direction. Furthermore, the modulation of cross-area correlations between similarly tuned populations is inversely related to the modulation of their mean responses, an observation that can be explained via a feedforward motion computation in MT and a modulation of local noise correlations in V1. More importantly, these modulations accompany an increase in the cross-area mutual information between direction-selective response patterns in V1 and MT, suggesting that attention improves the transfer of sensory information between cortical areas that cooperate to support perception. Finally, our model suggests that divisive normalization of neural activity in V1 before its integration by MT is critical to cross-area information coupling, both in terms of cross-area correlation as well as cross-area mutual information.
On the steady flow of a non-Newtonian fluid in cylinder ducts

The flow of a power law fluid in cylindrical ducts is considered, with a variational principle evolved from minimum entropy considerations used. This principle is applied to flow in rectangular ducts and between two flat plates with the method of Ritz and Galerkin to determine the velocity profiles used. These velocity profiles are used to determine the relationship between the friction factor and the Reynolds number.
Expert nursing diagnoses: The link between nursing care plans and patient classification systems

The two main tools used by the nurse in organizing and managing patient care are nursing care plans and the patient classification system. The author presents an overview of a novel approach that links these two tools through the use of expert nursing diagnoses and then applies the development and use of expert nursing diagnoses to the psychiatric setting. The author also describes the methodology used to develop the related patient classification, clarifies the validation procedure, gives examples of the final product, and considers the application and potential value of the total approach.
Establishing stimulus equivalences among retarded adolescents.

Abstract Two separate sets of stimuli were established as stimulus classes in a match-to-sample task by using each stimulus as both a sample and choice stimulus for every other member within that set. After classes were established, the subjects were taught to select one member of each class when an associated auditory stimulus was presented. After this training, three of six subjects were able to select the remaining members of each stimulus class in response to the appropriate auditory stimuli without direct training. The other three subjects also demonstrated transfer after additional members of each stimulus class were brought under the control of the auditory stimuli through direct training.
Arsenic toxicity is enzyme specific and its affects on ligation are not caused by the direct inhibition of DNA repair enzymes

The molecular mechanism of arsenic toxicity is believed to be due to the ability of arsenite [As(III)] to bind protein thiols. Numerous studies have shown that arsenic is cytotoxic at micromolar concentrations. Micromolar As can also induce chromosomal damage and inhibit DNA repair. The mechanism of arsenic-induced genotoxicity is very important because arsenic is a human carcinogen, but not a mutagen, and there is a need to establish recommendations for safe levels of As in the environment. We have measured the dose-response for arsenic inhibition of several purified human DNA repair enzymes, including DNA polymerase beta, DNA ligase I and DNA ligase III and have found that most enzymes, even those with critical SH groups, are very insensitive to As. Many repair enzymes are activated by millimolar concentrations of As(III) and/or As(V). Only pyruvate dehydrogenase, one of eight purified enzymes examined so far, is inhibited by micromolar arsenic. In contrast to the purified enzymes, treatment of human cells in culture with micromolar arsenic produces a significant dose-dependent decrease in DNA ligase activity in nuclear extracts from the treated cells. However, the ligase activity in extracts from untreated cells is no more sensitive to arsenic than the purified enzymes. Our results show that direct enzyme inhibition is not a common toxic effect of As and that only a few sensitive enzymes are responsible for arsenic-induced cellular toxicity. Thus, arsenic-induced co-mutagenesis and inhibition of DNA repair is probably not the result of direct enzyme inhibition, but may be an indirect effect caused by As-induced changes in cellular redox levels or alterations in signal transduction pathways and consequent changes in gene expression.
Precordial Movements over the Right Ventricle in Children with Pulmonary Stenosis

Twenty-three children with pulmonary stenosis were studied by means of displacement tracings taken over the right ventricle. The transducer was selected to pick up vibrations in the ultra-low frequency or palpable range. The patients were studied by cardiac catheterization and angiocardiography. Criteria previously established for normal children were applied to the patients with pulmonary stenosis. These provide a measure of the duration and relative height of the out-ward movement associated with ventricular systole. Recordings of precordial movement over the right ventricle in all of five children with severe pulmonary stenosis were abnormal by these criteria. Patients with mild pulmonary stenosis were normal in six of seven cases. An intermediate group (right ventricular peak pressures 60 to 100 mm. Hg) had abnormal records in seven of 11 instances. The "a" wave resulting from atrial contraction was exaggerated in severe pulmonary stenosis and was larger than normal in many of the mild and moderate cases. Recordings of precordial movement in pulmonary stenosis, though nonspecific in morphology, are nevertheless useful as an index of severity of the lesion, in timing phases of the cardiac cycle, in following the progress of cases before and after surgical interference, and as a method of improving appreciation of palpable phenomena at the bedside.
Discussion on “Sequential Design and Estimation in Heteroscedastic Nonparametric Regression” by Sam Efromovich

Abstract This is a short discussion piece on Professor Sam Efromovich's special invited paper. It includes three specific comments.
Direct Contact Gas-Liquid Heat Exchange for Energy Recovery

Expose de methodes et de criteres de conception pour la conception d'echangeurs a contact direct gaz-liquide pour la recuperation de la chaleur d'ecoulements de gaz chauds.
Toxic equivalency factor approach for risk assessment of combustion by‐products

Hazard and risk assessment of individual toxic chemicals utilizes data obtained from chronic toxicity and carcinogenicity studies in laboratory animals for regulating emission, cleanup or intake levels for individual chemicals. This approach can be utilized for problems associated with a single chemical emitted from a point source; however, in most situations, toxic chemicals are formed and emitted into the environment as complex mixtures of different structural classes of toxic/carcinogenic chemicals. Methodologies for risk assessment of complex mixtures have been developed for polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs) which are found as industrial and combustion by‐products. This methodology is based on the common mechanism of action for these chemicals and utilizes the most toxic PCDD/PCDF congener, 2, 3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD), as a reference compound. The relative potencies or toxic equivalency factors (TEFs) are assigned to the other relevant PCDD/PCDF congen...
Mind Over Magma: The Story of Igneous Petrology

In the centuries that inquiring minds have studied and theorized about igneous rocks, much progress has been made, both in accumulating observations and in developing theories. Yet, writing a history of this progress is a daunting undertaking. The volume of the literature is vast and in multiple languages; the various lines of inquiry are diverse and complex; and the nomenclature is sometimes abstruse. On top of these challenges, many of its principal issues have yet to find a definitive consensus. With the exception of a few topical studies, historians of science have virtually avoided the subject.
Effect of Site and Population Characteristics on Freeway Bottleneck Capacity

In an attempt to explain variations in prequeue flow (PQF) and queue discharge flow (QDF), one- and two-stage regression models that link high-volume PQF and QDF at freeway bottlenecks to site geometric, vehicle population, and driver population characteristics were developed and evaluated. One-stage models linked site characteristics directly to PQF and QDF; two-stage models used the average time gap in the critical lane and the ratio of critical lane flow to flow per lane as intervening variables (where time gap is the time separation between the rear of the lead vehicle and the front of the following one and critical lane is the lane with the highest flow). Explanatory variables included number of lanes, vertical alignment, proportion of heavy vehicles, and population characteristics derived from census data. Models were identified by stepwise regression analysis and evaluated by comparing predicted PQF and QDF values with the results of Highway Capacity Manual (HCM) capacity calculations and average v...
Evaluation and directions of the photovoltaic technologies

The status of, directions, and expectations for the photovoltaic technologies are discussed and updated, with emphasis on the performances of cells and modules used in various research and commercial solar cell approaches. Current and projected research and development directions are indicated. Special aspects of the current evolution of photovoltaics from the research laboratory to the commercial arena are discussed, including new programs directed to make this energy resource a viable electricity choice for users worldwide.
Separation of spin populations with gradient echoes as an aid in pulse sequence tuning

Tuning of nuclear magnetic resonance pulse sequences with pulsed "crusher" gradients or phase cycling serves to remove unwanted spin populations from the data acquisition window. Verification that unwanted spin population are not detected is often determined by the absence of obvious artifacts in an image. This approach is unsatisfactory in some instances because signal contamination with unwanted spin populations may not be obvious. This is a particular concern with multiple-spin echo, volume-selective, and other multiple-pulse sequences. A solution to this problem is the separation of spin populations using gradient echoes, allowing the existence of unwanted populations to be easily observed separately. Tuning of a pulse sequence is straightforward when spin populations can be independently observed.
Physiological traits associated with a reproductive-resting stage in Coullana canadensis (Copepoda: Harpacticoida)

We investigated physiological traits associated with a reproductive-resting stage in adult female harpacticoid copepods, Coullana canadensis (Willey). Our hypothesis was this stage represents a life-history strategy that could increase fitness by improving winter survivorship and future reproductive success in spring. To test if physiological rates are suppressed in this stage, we compared gut-cell morphology, nitrogen excretion rates, enzyme activities, and phytoplankton grazing rates of reproductive-resting and reproductive females reared in the laboratory under high food conditions. Copepods came from laboratory cultures originating from individuals collected in Maine and Maryland, USA in 1990. Reproductive-resting females had lower physiological rates, and the surface area of gut-cells was reduced compared to reproductive females. Distinct morphological differences in the distribution of lipids between reproductive and reproductive-resting females were observed under light and electron microscopy, the latter having a diffuse accumulation of lipid in the area normally occupied by the ovaries. Differences in lipid composition were also found. Reproductive copepods had a significantly higher ratio (%) of polar lipids to total lipid, and a lower proportion of triacylglycerols compared to reproductive-resting copepods. These laboratory findings are consistent with the hypothesis that the reproductive-resting stage in C. canadensis is an adaptive response to increase winter survival.