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Disease, injury and aging induce pathological reactive astrocyte states that contribute to neurodegeneration. Modulating reactive astrocytes therefore represent an attractive therapeutic strategy. Here we describe the development of an astrocyte phenotypic screening platform for identifying chemical modulators of astrocyte reactivity. Leveraging this platform for chemical screening, we identify histone deacetylase 3 (HDAC3) inhibitors as effective suppressors of pathological astrocyte reactivity. We demonstrate that HDAC3 inhibition reduces molecular and functional characteristics of reactive astrocytes in vitro. Transcriptional and chromatin mapping studies show that HDAC3 inhibition disarms pathological astrocyte gene expression and function while promoting the expression of genes associated with beneficial astrocytes. Administration of RGFP966, a small molecule HDAC3 inhibitor, blocks reactive astrocyte formation and promotes neuroprotection in vivo in mice. Collectively, these results establish a platform for discovering modulators of reactive astrocyte states, inform the mechanisms that control astrocyte reactivity and demonstrate the therapeutic benefits of modulating astrocyte reactivity for neurodegenerative diseases.

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The population presenting with cardiogenic shock is heterogenous. Anemia is common in advanced heart failure and associated with poor outcomes. Microaxial flow pumps may cause ongoing blood trauma and worsen anemia. Treatment with recombinant erythropoietin, iron, vitamin B, and folate is recommended before cardiac surgery to reduce perioperative transfusion requirements but no data exist on the feasibility and safety during support with microaxial flow pumps. This novel strategy was born out of necessity to support a Jehovah’s Witness who opposes blood transfusion but required mechanical circulatory support. We present its efficacy over the duration of 19 days of Impella 5.5 support where hemoglobin level remained stable, and platelet count significantly improved despite a brief episode of gastrointestinal bleeding. No thromboembolic complications occurred. We anticipate this strategy could help not only Jehovah’s Witnesses, but also patients awaiting cardiac transplantation since transfusions stimulate development of antibodies which may preclude or postpone finding a suitable donor organ. Furthermore, it may minimize or prevent perioperative needs for transfusions for patients being bridged to durable left ventricular assist devices.

Zielsetzung: Ziel der Arbeit war es, einen Überblick über derzeit verfügbare Anwendungen künstlicher Intelligenz (KI) und Simulationstechniken in der Pränatalmedizin mit dem Schwerpunkt auf eine mögliche Verbesserung der Aus- und Weiterbildung zu geben. Methoden: Es werden in der Pränatalmedizin existierende KI-Anwendungen sowie Simulatoren anhand von Beispielen und Studien vorgestellt. Schlussfolgerung: KI-Anwendungen werden zunehmend in den klinischen Alltag eingebunden und können zukünftig auch für die Aus- und Weiterbildung interessant werden. Strukturiertes simulationsbasiertes Ultraschalltraining sollte in ein Ausbildungscurriculum integriert werden.

Noble gas concentrations in natural waters are widely used to determine ambient temperature conditions during the last intensive contact with the atmosphere (equilibration). Such applications require accurate solubility functions, which so far are available only for the common environmental temperature range between (0 and 35) °C. Nonetheless, environmental scenarios that generate higher surface-water temperatures (such as volcanism) exist. Previous solubility measurements beyond ∼35 °C are sparse or outdated and were determined through equilibration of water with pure noble gases. This can potentially render them not suitable for environmental applications where equilibration with atmospheric air is considered. We therefore conducted new measurements for the solubilities of helium, neon, argon, krypton, and xenon in deionized water equilibrated with atmospheric air at ∼1 bar for temperatures ranging from (25 to 80) °C. These measurements were combined with data from the literature that were obtained in a similar manner and fitted with a commonly used function to determine new noble gas solubility functions valid from (0 to 80) °C. We estimate relative standard uncertainties with a 0.99 level of confidence between 0.015 and 0.030 for the new functions, which are thus suitable for the investigation of environmental high-temperature equilibration scenarios. For temperatures beyond 35 °C, the new functions deviate significantly from previous studies.

This article explores the significance of pricing management for businesses during times of disinflation. It emphasizes the need for businesses to remain proactive and develop adaptable pricing strategies, even when inflation rates are decreasing. The article examines how market dynamics, such as labor shortages and supply chain disruptions, have affected pricing and margin management. It also discusses the challenges businesses face in meeting margin management expectations and offers recommendations for strengthening pricing capabilities. The article highlights the benefits of adopting a holistic approach to revenue growth management, with examples of successful pricing strategies. It emphasizes the importance of technology, capability building, and data-driven decision-making in optimizing sales and pricing. Ultimately, the article concludes that enhancing pricing capabilities can significantly impact company performance. [Extracted from the article]

Hintergrund:Die Coronavirus-Pandemie 2019 (COVID-19) ist eine anhaltende globale Krise, die die weltweiten Gesundheitssysteme herausfordert. Bei vielen Patienten besteht ein Missverhältnis zwischen schwerer Hypoxämie und wenigen Anzeichen von Atemnot (d.h. stille Hypoxämie). Dieses besondere klinische Bild wird häufig angeführt, aber die Daten sind begrenzt. Hauptteil:Die vorliegende Studie beschreibt das Empfinden von Dyspnoe, das mithilfe der BORG-Skala über einen Zeitraum von 4 Wochen bei Lungenpatienten ermittelt wurde, die in die Notaufnahme aufgenommen und dann in die Lungenabteilung des Siloah-Krankenhauses in Hannover verlegt wurden. Vom 1. Oktober bis zum 1. November 2020 wurden 82 Patienten mit Hypoxämie, definiert mit einem Sauerstoffbedarf zum Erreichen einer Sauerstoffsättigung (SpO2) ≥92%, eingeschlossen. Bei 45/82 (55%) Patienten wurde bei der Aufnahme durch PCR SARS-CoV-2 nachgewiesen. Bei den Nicht-COVID-Patienten war die Exazerbation der COPD die Hauptdiagnose (15/37, 41%). Alle Probanden bewerteten ihre wahrgenommene Dyspnoe anhand der modifizierten Borg-CR10-Skala. Die Patienten in der Nicht-COVID-Gruppe litten mehr unter Dyspnoe auf der modifizierten Borg-CR10-Skala (Median 1, IQR: 0–2 vs. Median 5, IQR: 3–6, p< 0,001). In der multivariaten Analyse war eine «stille Hypoxämie», definiert durch die Dyspnoe-Borg-CR10-Skala ≥5, unabhängig von COVID-19 und dem Vorhandensein einer schweren Hypokapnie mit einer Odds Ratio von 0,221 (95%-Konfidenzintervall 0,054, 0,907, p0,036) verbunden. Schlussfolgerungen:Bei Lungenpatienten mit akuter Hypoxämie, die mit einem Sauerstoffbedarf definiert wurden, leiden COVID-19-Patienten im Vergleich zu Nicht-COVID-Patienten weniger unter Dyspnoe. «Stille» Hypoxämie trat bei COVID-19-Patienten häufiger auf.

Sexual and social adjustment appears to be satisfactory in male-to-female transsexuals and women with vaginal abnormalities who have surgery to create a new vagina from colon tissue. Interviews were conducted with 10 male-to-female transsexuals and nine women with vaginal dysgenesis who had had surgery to create functional vaginas. Their physical and psychological adjustment was followed for an average of 52 months. Vaginal dysgenesis is an abnormal formation of the vagina that usually occurs during embryonic development. Overall, 18 of 19 patients had an adequate anatomic vagina on physical examination for size. Eighteen of the patients reported having sexual intercourse. Sexual adjustment was rated as either good or satisfactory in 12 patients. Doubts about their female identity were raised by more than half of the patients with vaginal dysgenesis. None of the transsexuals expressed doubts about their identity. In 16 patients social adjustment was rated as good or satisfactory. Two transsexuals were rated as doubtful on the social adjustment scale, primarily because relations with family members were causing distress.

Consumers express interest in buying green products, but their behavior does not always align with their intent. To better understand consumer demand for sustainable options, companies can use an auction-based testing model. This approach simulates real-life buying situations and provides insight into which green claims resonate with customers. The findings from a study conducted in Germany can help companies worldwide develop eco-friendly and socially responsible products. The article is authored by Tjark Freundt, Cornelia Grossmann, Sascha Lehmann, and Yvonne Staack, and it draws on joint research by McKinsey & Company and Veylinx. [Extracted from the article]

Marketplaces that prioritize sustainability in their product offerings not only decarbonize faster but also perform better financially. Research from McKinsey shows that certain features, such as bundled delivery and eco-friendly packaging, are more influential in driving customer purchases of sustainable products compared to other features like reducing emissions by extending delivery times. Additionally, higher-income and younger demographics are more engaged in sustainability, with Gen Z and millennials placing greater importance on brands' greenhouse gas emissions. To effectively address sustainability, marketplaces should establish emissions baselines, encourage green purchases, implement sustainable packaging and delivery, provide transparency on emissions footprints, and promote reused and refurbished sales. [Extracted from the article]

Health care organizations across the country project that merit increases for top managers will average 5.2 percent this year-roughly the same average percentage awarded in both 1989 and 1988. That's [...]

Recent large-sample customer surveys in Europe, for instance, show about 60 percent of customers are open to purchasing adjacent - that is, ecosystem - services from retailers and telecommunications operators (exhibit). These value propositions helped build much deeper customer relationships and more frequent customer engagement through new digital-service offerings. Yet ecosystem efforts also drive tangible business impact in the near term by delivering on critical customer priorities: I Accelerated customer acquisition. i Companies can deploy ecosystem strategies to acquire new customers across new segments, such as improving the customer value proposition by adding complementary products and services, enhancing digital channels, forming a strategic customer acquisition partnership, or simply enhancing their presence on others' platforms. [Extracted from the article]

Top management salaries inch up to 4.8% in 1988 Average merit increases for hospital managers are expected to remain relatively stable at 4.8 percent this year--as compared with 4.7 percent [...]

Background:Primary graft dysfunction (PGD) is devastating. Amiodarone therapy prior to cardiac transplantation (TxP) is common but has recently been reported as potential cause of PGD.Case:66-year-old male with non-ischemic cardiomyopathy, severely reduced LVEF with LVAD, recurrent VT on amiodarone for 6 months presented with ICD shocks. Amiodarone was increased due to VT storm in the setting of Rhinovirus infection. Infusions with amiodarone and lidocaine were started but repeat IV boli of lidocaine and amiodarone were needed. VT-ablation was not feasible due to multiple morphologies. He underwent TxP with an ideal organ from a 28 yo donor. Paragonix SherpaPak was used for transport. Pre-explanation EF was 70% with serologies positive for EBV (+/+), Strongyloides (+/-), negative for Toxoplasmosis (-/-), CMV (-/-). Donor heart was arrested with appropriate cardioplegia and no distention occurred. Total ischemic time was 3 hours 10 minutes, warm ischemic time 40 minutes, crossclamp time in recipient 2 hours 2 minutes with total cardiopulmonary bypass time 2 hours 58 minutes. Coming off bypass both ventricles appeared markedly dilated with severely reduced function and due to high doses of inotropic and vasopressor support veno-arterial ECMO was placed. The chest was left open and during postoperative course in the intensive care unit pressor and inotropes could slowly weaned. Induction therapy was administered with ATG, Solumedrol and mycophenolate mofetil. Strongyloides infection was treated with four doses of Ivermectin. On postoperative day LVEF recovered to 40-45% with moderately reduced RV function and patient was successfully decannulated from VA ECMO with chest closure. Endomyocardial biopsies showed no signs of rejection throughout. After prolonged ICU and rehab stay patient has now recovered to independent life.Conclusion:Amiodarone associated PGD may be underreported and increasing awareness of this etiology may warrant early empiric discontinuation of the medication if transplantation remains a therapeutic option in the future.

Background:Heart transplant (HTX) candidates often develop cardiogenic shock (CS) and require mechanical circulatory support (MCS). UNOS criteria prioritize temporary MCS over durable left ventricular assist devices (LVADs). Extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pump are associated with poor outcome. In early 2020, we transitioned to using axillary Impella 5.5 in CS patients with both isolated LV or biventricular failure as bridge to HTX. This reports our two-year experience.Methods:We performed a retrospective single center chart review. 19 patients treated with Impella 5.5 as bridge to HTX were identified. UNOS criteria were used to classify CS. If inotropes and diuresis failed to resolve CS, Impella 5.5 was placed via a 10 mm graft sewn to the axillary artery. Key endpoints were survival to transplant without disabling stroke, 30-day and 1-year post-HTX survival.Results:Mean age 55 yrs, 89% male, mean Impella support 19 days (2 - 71, total 369). 58% biventricular failure with at least moderate right ventricular dysfunction (RVD). RVD was managed medically, no RV assist device or ECMO was needed. Transient elevation (>40 mg/dl) of free plasma hemoglobin occurred in 42% but resolved with device repositioning and/or fluids. No renal replacement therapy was required. No serious infectious, vascular or bleeding complication occurred. There was no device malfunction, one pump was replaced due to an exposed wire after 22 days of support. 100% of patients were able to ambulate prior to HTX. Overall survival was 100%. 89% patients were successfully bridged to HTX without major morbidity. Two cases received durable LVAD. One developed non-disabling ischemic stroke on day 16 of Impella support. One elected LVAD as destination therapy after 71 days of support. Stroke free survival during Impella support was 95%. There were no disabling strokes. Post-transplant 30-day survival was 100% (n=17). 1-year post-HTX survival data was 100% (n=10).Conclusion:Impella 5.5 successfully restores hemodynamics in CS in HTX eligible patients with both isolated LV and biventricular failure. RVD in this situation can be managed medically. With this strategy, patients are able to ambulate prior to HTX and survival after HTX exceeds national average.

The paper reports a study of the quality of the substrate/epilayer interface. Before growing the Si or Si/Si1-xGexstructures by low pressure chemical vapour deposition, Si(100) substrates were cleaned by a modified RCA-cleaning and just before epitaxy different ex-situ and in-situ processes were applied to remove the oxide layer grown on the wafer substrates in the last step of the RCA-cleaning. The effect of interfacial contamination on electrical and optical properties were studied. By a wet-chemical removal of the oxide layer an interfacial oxygen level of 1.3x1013atoms/cm2is found, while a thermal removal leads to an interfacial oxygen level below 6x1012atoms/cm2. In both cases carbon levels of (1-2)x1014atoms/cm2have been detected. By electrochemical capacitance-voltage profiling it was found that these contaminations are connected with electrically active donors. According to our investigations, electrochemical capacitance-voltage profiling is suitable to give a quick indication on the quality of the substrate/epitaxial interface. In addition, the removal of the oxide layer was investigated by high resolution electron energy loss spectroscopy on cleaned Si-surfaces.

Social protection against unemployment is on the European agenda because of the economic crisis. Since European family patterns have changed over the last three decades, the social protection for unemployment may be very different during this economic crisis from what it was previously. In particular the combination of more diverse families and high unemployment raises the general question of how today's systems of social protection cater for different types of families and income groups. Based on a micro-simulation analysis, this article examines how, and to what extent, packages of social security provide support for various types of unemployed families at different income levels. The comparison is between four countries representing different welfare state models and dominant family types. Using the OECD Tax-Benefit model, the article surveys the disposable income and provides a breakdown of benefits for different family types facing unemployment. It takes into account housing costs and childcare costs, and the benefits related to them. The analysis shows that unemployed families experience different levels of support depending not only on the country they live in, but also on their income level and family type. Often differences between families at different income levels within countries are larger than differences between families at the same income level between countries. The analysis illustrates how important it is to look beyond unemployment insurance and include family related benefits to understand the support provided to families faced with unemployment.

Examining the generosity of welfare states and individual benefit schemes is a classical task in comparative welfare state studies. Three types of welfare states can be discerned based, in part, on their level of benefit generosity. Although significant advances have been made in the development of measures of welfare state generosity, this progress has not been without its challenges and limitations. In this article, the authors examine two sets of limitations related to measurement validity in comparative welfare state research: securing content validation and ensuring comparability across time and place. Through the use of illustrative examples to compare the situation of the unemployed in five European countries across several income levels and two family types, we demonstrate that, by profiling and stacking public benefits using the OECD Tax-Benefit micro-simulation model, we are able to carry out a more informed analysis of the redistributive strategies of the welfare state.

One 5-cell SOFC stack has been tested under both hydrogen and direct internal steam reforming of methane for a total duration of 3200 hours. Electrochemical impedance spectroscopy has been used to monitor the evolution of internal resistances of all repeating units in the stack. It has been found that repeating units in the stack degraded two times faster under direct internal steam reforming of methane (6.7 - 14.4%/kh voltage degradation) than under H2 (2.3 - 4.0%/kh). In combination with impedance results, this indicates deterioration of the anode as the main cause of degradation for operation under CH4/H2O. The degradation process is at least partially reversible when changing the gas from CH4 to H2.

The entrance of hot pyroclastic flows into water has been observed in a series of experiments in which shooting granular flows of hot ignimbrite ash (≤403 °C), of bulk density near that of water, run down a smooth chute and enter a water-filled tank at an angle of 26°. Flows of relatively cool ash (<150 °C) impulsively displace some volume of near-shore water upon impact, generating a water wave that rapidly travels away from shore. The granular flow material then separates into two portions. (1) A fine-ash surge cloud is formed where the granular flow hits water and rapidly travels down-tank over the water. (2) The main portion of material penetrates the surface and mixes with the water, creating a turbulent mixing zone resembling a hydraulic jump, which advances downstream as long as the pyroclastic flow is maintained. Most pumice floats to the surface, lithics and coarse ash fall out onto the floor, but ash that remains in suspension forms a turbidity current that travels down the floor of the tank. With increasing ash temperature, an increasing fraction of incoming material is initially transported along the water surface; almost all material takes this path at temperatures >250 °C. Mixing across the water surface over some distance from shore generates steam explosions forming fountains of wet and dry ash and convectively rising fine-ash plumes. Steam explosions increase in strength and lateral extent towards higher ash temperatures and mass fluxes. The explosions generate water waves that remain driven by massive fountain fallout across some distance from shore. The ash fountains feed pyroclastic surges, which advance down tank over water at high speeds. Underwater plumes of sediment falling from the ash fountains and surges drop coarse load onto the floor whereas the finer load forms a turbidity current. High temperature and poor size sorting of pyroclastic flows are key parameters that determine the processes of interaction with water and the associated hazards. Poor sorting allows for the formation of ash-cloud surges moving over water, even from cool flows. High temperatures cause littoral explosions and facilitate extensive mass transport over water. All flows generate tsunami waves by different mechanisms.

•Provide experimental evidence on how risks in different dimensions of the return from a public good impact investments decisions.•Identify a particularly strong effect of the risk in the public component of the return.•Demonstrate that the correlation between private and public returns is crucial when risks in both dimensions exist.•Provide insights into behavioral motivations of pro-social behavior.

Abstract:  Analogue experiments in part I led to the conclusion that pyroclastic flows depositing very high-grade ignimbrite move as dilute suspension currents. In the thermo–fluid–dynamical model developed, the degree of cooling of expanded turbulent pyroclastic flows dynamically evolves in response to entrainment of air and mass loss to sedimentation. Initial conditions of the currents are derived from column-collapse modeling for magmas with an initial H2O content of 1–3 wt.% erupting through circular vents and caldera ring-fissures. The flows spread either longitudinally or radially from source up to a runout distance that increases with higher mass flux but decreases with higher gas content, temperature, bottom slope and coarser initial grain size. Progressive dilution by entrainment and sedimentation causes pyroclastic currents to transform into buoyant ash plumes at the runout distance. The ash plumes reach stratospheric heights and distribute 30–80% of the erupted material as widespread co-ignimbrite ash. Pyroclastic suspension currents with initial mass fluxes of 107-1012 kg/s can spread for tens of kilometers with only limited cooling, although they move as supercritical, strongly entraining currents for the eruption conditions considered here. With increasing eruption mass flux, cooling during passage through the fountain diminishes while cooling during flow transport increases. The net effect is that eruption temperature exerts the prime control on emplacement temperature. Pyroclastic suspension currents can form welded ignimbrite across their entire extent if eruption temperature is To>1.3.Tmw, the minimum welding temperature. High eruption rates, a large fraction of fine ash, and a ring-fissure vent favor the formation of extensive high-grade ignimbrite. For very hot eruptions producing sticky, partially molten pyroclasts, analysis of particle aggregation systematics shows that factors favoring longer runout also favor more efficient aggregation, which reduces runout. As a result, very high-grade ignimbrites cannot spread more than a few tens of kilometers from their source. In cooler pyroclastic currents, particles do not aggregate, and the sedimentation process may involve re-entrainment of particles, which potentially leads to more extensive cooling and longer runout; such effects, however, are only significant when net erosion of substrate occurs. Model results can be employed to estimate mass flux and duration of ignimbrite eruptions from measured ignimbrite masses and aspect ratios. The model also provides an alternative explanation of the observed decrease in H/Lratios with ignimbrite mass.

Exposure of rats to 20 ppm CS2 (the current MAC in various countries) for 8 h was followed by i.p. administration of 2 g/kg ethanol (blood level: 3-1‰) and another up to 4-h exposure to the same concentration of CS2. During the second exposure the acetaldehyde concentration increased significantly, the rise representing one third of the control values. Inhalation of 400 ppm CS2 for the same period, or 8-h exposures at 400 ppm CS2 on 5 consecutive days produced only a slight additional increase in acetaldehyde. The increased appearance of acetaldehyde in blood is considered to be due to inhibition of aldehyde dehydrogenase by CS2. This conclusion was derived from the significant lag in the clearance rate of acetaldehyde given i.v. (1 mmol/kg) after exposure at 400 ppm CS2/8 h, involving an increase of the excretion half-life of acetaldehyde (1 min, 45 s in the controls) to 2 min, 24 s. The finding thus obtained could be reproduced in man (adult males). At a blood alcohol concentration of approximately 0.75‰, maintained at this level for 8 h, the blood acetaldehyde concentration was found to be approximately 6 × 10-3‰; it rose significantly by about 50% during simultaneous 8-h exposure of the test subjects to a nonfluctuating, analytically defined concentration of 20 ppm CS2. When increasing the dose Of CS2 to 40 ppm and 80 ppm for 8 h, only a slight additional increase was noted. Administration of ethanol (ca. 0./5‰) for 8 h, instituted at 16 h after 8-h inhalation of 20 ppm CS2, produced a rise in blood acetaldehyde to slightly more than twice the control value. An approximately identical quantitative effect was observed after exposure to 20 ppm on 5 consecutive days at the same time of the day (8.00 a.m. - 4.00 p.m.). Under the conditions employed, there was no evidence of any subjective or objective signs of alcohol intolerance in terms of an “antabuse syndrome” in the experiments. Inhalation of CS2 vapor failed to exert a significant effect on the pharmacokinetic behavior of ethanol in with a blood alcohol content up to 0.8%., contact with CS2 is not likely to give rise to a CS2-alcohol reaction, provided the concentrations of CS2 encountered in the work environment are within the range of the MAC.

The possibilities of obtaining information about interband scattering processes in the bandgap regime of GaN from electron energy‐loss spectra, taken in a dedicated scanning transmission electron microscope (STEM), are investigated. With the help of precise simulations of the zero‐loss peak it is feasable to process, extract and analyse data in the extreme low‐loss regime of a few electronvolts. The accuracy of the results is restricted predominantly by instrumental broadening functions. By modelling these accurately, it is possible to eliminate the effects of the tail of the zero‐loss peak and to extract the low‐loss spectrum together with the correct value for the bandgap of GaN. Furthermore, differences in the shapes of the low‐loss spectra can be revealed, depending on the microstructural features, probed at different beam locations.

We report experiments on the flow of two fluids of contrasting viscosity through a pipe in which low-viscosity fluid occupies the center of the pipe. The volume flux of the low-viscosity fluid in the pipe increased during an experiment but did not reach 100% in most cases. The transition from high- to low-viscosity-dominated outflow involved a drop in pressure gradient and an increase in flow rate due to reduced viscous resistance in the pipe. Initially, the central flow was thin and parallel-sided, but as its diameter increased the flow became unstable. A sequence of instabilities was observed during the course of each experiment, both in time and as a function of height in the pipe. In the most commonly observed instability the central flow adopted a helical geometry. The transition from parallel-sided to unstable flow first appeared at the top of the pipe and propagated downwards against the flow. Axisymmetric instabilities originating at the pipe entrance were also observed. All forms of instability exhibited entrainment of viscous fluid into the faster moving central flow. Entrainment was extensive early in the existence of the central flow, but later on the volume flux of lower-viscosity fluid in the central flow rose more rapidly than the rate of entrainment and the proportion of lower-viscosity fluid increased with time. These compositional changes determined the viscosity of the central flow which was found to control its diameter and velocity. In banded pumice deposits, silicic pumice without mafic component is commonly erupted alongside banded pumice blocks. We infer that banded pumice may correspond to the central flow in our experiments, i. e., that viscous magma has been incorporated into less viscous melt, and that pure acid pumice is derived from the outer flow. Changes in eruption style may be caused by variations in pressure gradient and flow rate due to changes in the viscosity of the melt in the conduit. Varied mafic/silicic proportions and degree of mixing in magmatic associations are controlled by the bulk volume erupted, discharge rate, initial temperature difference and aspect ratio of the conduit.

We distinguish three eruptive units of pyroclastic flows (T1, T2, and T3; T for trass) within the late Quaternary Laacher See tephra sequence. These units differ in the chemical/mineralogical composition of the essential pyroclasts ranging from highly differentiated phonolite in T1 to mafic phonolite in T3. T1 and T2 flows were generated during Plinian phases, and T3 flows during a late Vulcanian phase. The volume of the pyroclastic flow deposits is about 0.6 km3. The lateral extent of the flows from the source vent decreases from > 10 km (T1) to < 4.5 km (T3). In the narrow valleys north of Laacher See, the total thickness of the deposits exceeds 60 m.

The transverse disposition of exposed protein antigens on the two faces of isolated Mycoplasma gallisepticum membranes have been investigated by using indirect immunoferritin labeling to accomplish visualization of the antigens at the ultrastructural level. Comparison between the labeling patterns obtained with unabsorbed specific mycoplasma antiserum and antiserum from which antibodies directed against outer side determinants had been removed revealed that the majority of protein antigens were the same on the opposed membrance faces or at least displayed extensive interside cross-reactivity. The relatively scarce tagging of isolated Acholeplasma laidlawii membranes, contrary to membranes on intact organisms observed in this investigation, precluded conclusions regarding the disposition of membrane antigens of this species. The advantages and limitations of the employed method in disposition studies and the factors influencing the transverse distribution of membrane proteins in mycoplasmas are discussed.

Electron microscopy of thin sections of Thermoplasma acidophilum confirmed previous observations of the absence of a typical cell wall in this organism. Negatively stained specimens revealed the almost consistent occurrence in both strains examined of monotrichously arranged flagella, about 9 micrometer long, which describe a sinuous curve with a wavelength of 1.5 to 2.0 micrometer and an amplitude of 0.33 to 0.59 micrometer. Motility of T. acidophilum could be demonstrated microscopically by microcinematography and macroscopically. The theoretical implications of the demonstration of functioning flagella in a wall-defective organism are discussed in the light of current theories of the mechanism of flagellar motility and from a taxonomic point of view.

Total body water (TBW) is an indicator of fat-free mass and thus of nutritional status but cannot be measured readily in children in developing countries who are at greatest risk of becoming malnourished. We therefore developed equations to predict 18O TBW from bioelectrical impedance (Z), wt, and ht in well and malnourished infants and children whom we considered characteristic of children evaluated in nutritional surveillances in Peru. Children 3 to 30 mo of age, whose wt were 3.4 to 14.4 kg, which was —2.8 to 1 SD wt-for-ht, were randomly assigned to group I (n30) to develop equations to predict TBW or to group II («14) to cross-validate the predictive equations. Mean TBW measured by 180 dilution was 4.8 ± 1.2 kg in group I, and 5.6 ± 1.7 kg in group II. TBW ranged from 57 to 78 of body wt (65 ± 6) in group I and from 56 to 80 (64 ± 6) in group II, indicating no statistically significant differences in body composition. The following equation was developed and cross-validated TBW, kg0.48 0.68 ht2Z; standard error estimate0.36; r0.98). A slight improvement was achieved by the addition of body wt (TBW, kg0.76 0.18 ht2Z 0.39 wt; standard error estimate0.23; r0.99).

Abstract:  High-grade ignimbrites are thought to be deposited by pyroclastic flows at temperatures exceeding minimum welding temperature or even solidus temperature. Corresponding pyroclastic-flow particles range from plastic to partially liquid and are able to aggregate or coalesce. This contrasts with particles in pyroclastic flows producing unwelded ignimbrite, which are capable of elastic grain interactions. The low aspect ratio and great areal extent of high-grade ignimbrites requires transport in a particulate state either by (a) high-concentration mass flow facilitated by fluidizing gas reducing internal friction, or by (b) expanded turbulent flow of low but downward increasing concentration. This paper presents experiments designed to investigate the effects of plastic to liquid particles on these two contrasting transport mechanisms. Gas fluidization experiments using polyethyleneglycole (PEG) powders heated above minimum sintering (Tms) and melting (Tm) temperatures cover a wide range of fluidization velocities (Umf>Ua>0.6·Ut) but are always in the bubbly fluidization regime similar to fluidized ignimbrite ash, where particle volume concentration outside the bubbles is high (≈10–1). When the powders reach a critical temperature Tm≥T≥Tms, defluidization by catastrophic particle aggregation immediately commences in both stationary and laterally moving fluidized beds as well as in experiments using mixtures of high- and low-Tm (≥30 wt.%) PEG powders, when T≥Tms of the lower-Tm powder. This indicates that extended particulate transport at T≥Tms is not possible at such high particle concentrations. In the turbulent flow experiments, liquid sprays of molten PEG or water, vertically injected into a high-Re (>104) horizontal air flow, form a low-concentration (10–5 to 10–4) turbulent suspension current. Proximal formation of partially coalesced aggregates, which settle faster than individual particles, causes the measured downstream decay of sedimentation rate to be steeper than predicted by theory of single solid-particle sedimentation from turbulent suspensions. As particles become finer downstream and coalescence efficiency decreases in response to cooling, more distally formed aggregates become too small and rare to modify sedimentation-rate decay from that of suspension flows containing solid particles. The key difference between the two transport systems is particle concentration, C. Since particle collision rate Rcoll∝C2, collision rates in fluidized beds are so high that all particles immediately aggregate when coalescence efficiency (1≥Ecoal≥0) is larger than 10-3. Low-concentration suspensions, on the other hand, require much higher values of Ecoal for significant aggregation to occur. Dilute pyroclastic flows will have higher particle volume fractions (≈10–3) than the experimental currents, but then viscous pyroclasts should have lower coalescence efficiencies than PEG droplets. Experimental results thus support an expanded turbulent transport mechanism of pyroclastic flows generating extensive high-grade ignimbrite sheets.

Adult female rats were exposed for 8 h to graded carbon-disulfide (CS2) concentrations between 20 and 400 ppm. It was found that the lipid content of the hepatic microsomal fraction rose significantly due to an increase in phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylserine, sphingomyeline, lysophosphatidylcholine, cholesterol, triglycerides, diglycerides, and free fatty acids. The alterations occurred quickly and were completely reversible after exposure. Since the microsomal cytochrome P-450 content, as well as the activity of the microsomal NADPH cytochrome c-reductase, remained within the normal range following identical CS2 exposures, it is assumed that the alteration in the lipid pattern of the endoplasmic reticulum is a causal factor in inhibition of the microsomal-oxidative drug metabolism, induced by identical inhalatory CS2 doses. It is suggested that the altered lipid pattern impairs the microsomal membranes, thus affecting electron transport and resulting in a dysfunction of the oxidation chain. A slight elevation of the microsomal total protein was observed in relation both to a rise of the microsomal RNA content and an enhanced incorporation of [2,4 -3H]-L-phenylalanine into the liver microsomes after identical CS2 exposures. It is considered that this finding might represent an unspecific stimulatory reaction.