A digitally controlled system for effecting and presenting a selected electrical resistance

A digitally controlled resistance generator is described, in which resistors having values selected according to an expression 2(sup N-1)(R), where N is equal to the number of terms in the expression, and R is equal to the lowest value of resistance, are electrically inserted into a resistive circuit in accordance with a parallel binary signal provided by an analog-to-digital converter or a programmable computer. This binary signal is coupled via optical isolators which, when activated by a logical 1, provides a negative potential to some or all of the gate inputs of the normally on field effect transistors which, when on, shorts out the associated resistor. This applied negative potential turns the field effect transistors off and electrically inserts the resistor coupled between the source terminal and the drain terminal of that field effect transistor into the resistive circuit between the terminals

Big words, small phrases: Mismatches between pause units and the polysynthetic word in Dalabon

This article uses instrumental data from natural speech to examine the phenomenon of pause placement within the verbal word in Dalabon, a polysynthetic Australian language of Arnhem Land. Though the phenomenon is incipient and in two sample texts occurs in only around 4% of verbs, there are clear possibilities for interrupting the grammatical word by pause after the pronominal prefix and some associated material at the left edge, though these within-word pauses are significantly shorter, on average, than those between words. Within-word pause placement is not random, but is restricted to certain affix boundaries; it requires that the paused-after material be at least dimoraic, and that the remaining material in the verbal word be at least disyllabic. Bininj Gun-wok, another polysynthetic language closely related to Dalabon, does not allow pauses to interrupt the verbal word, and the Dalabon development appears to be tied up with certain morphological innovations that have increased the proportion of closed syllables in the pronominal prefix zone of the verb. Though only incipient and not yet phonologized, pause placement in Dalabon verbs suggests a phonology-driven route by which polysynthetic languages may ultimately become less morphologically complex by fracturing into smaller units

The challenge of transferring a US movement to countries outside the US

With the help of authors such as Wolfgang Sachs (1999 and 2002), this paper examines the possibility of expanding the US concept of environmental justice to a global scale. Through the body of literature reviewed, the paper concludes that the US environmental justice concept can be applied outside its borders. However, the concept will need to be molded into new forms that are tailored to the countries in which it is applied. The elements, which promote a critical, community-concentrated and bottom-up approach are those which will be most useful when expanding environmental justice beyond the US borders. In addition, as referred to in Wolfgang Sachs’ 2002 article, a focus on “lowering the top” to bring resource-usage to more sustainable levels is something which will only benefit environmental justice and its success in the future

Flame spread across liquid pools

For flame spread over liquid fuel pools, the existing literature suggests three gravitational influences: (1) liquid phase buoyant convection, delaying ignition and assisting flame spread; (2) hydrostatic pressure variation, due to variation in the liquid pool height caused by thermocapillary-induced convection; and (3) gas-phase buoyant convection in the opposite direction to the liquid phase motion. No current model accounts for all three influences. In fact, prior to this work, there was no ability to determine whether ignition delay times and flame spread rates would be greater or lesser in low gravity. Flame spread over liquid fuel pools is most commonly characterized by the relationship of the initial pool temperature to the fuel's idealized flash point temperature, with four or five separate characteristic regimes having been identified. In the uniform spread regime, control has been attributed to: (1) gas-phase conduction and radiation; (2) gas-phase conduction only; (3) gas-phase convection and liquid conduction, and most recently (4) liquid convection ahead of the flame. Suggestions were made that the liquid convection was owed to both vuoyancy and thermocapillarity. Of special interest to this work is the determination of whether, and under what conditions, pulsating spread can and will occur in microgravity in the absence of buoyant flows in both phases. The approach we have taken to resolving the importance of buoyancy for these flames is: (1) normal gravity experiments and advanced diagnostics; (2) microgravity experiments; and (3) numerical modelling at arbitrary gravitational level

Large-Scale Structure Tests of Cosmological Models

We investigate the use of $N$-body simulations and large-scale galaxy clustering in order to test two cosmological models: an Einstein-de Sitter model where neutrinos act as the dominant Hot Dark Matter (HDM) component; and the standard $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model. We investigate the matter power spectra and halo mass functions of the neutrino model, and of an extended model that includes Primordial Magnetic Fields (PMFs), which have the effect of introducing `seeds' into the matter distribution. We find that neither model performs as well as $\Lambda$CDM in generating structure, but note that the use of PMFs completely reverses the process of structure formation in the HDM model, allowing it to progress in a bottom-up manner. We calculate the redshift-space two-point galaxy-galaxy correlation function, $\xi(s)$, of the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7) MAIN galaxy catalogue, and fit this to both the $\Lambda$CDM model and the neutrino model. assuming a $\Lambda$CDM cosmology, we obtain a best-fit value for the spherically averaged distance to redshift $z~=~015$, given as $D_V(0.15)~= \left(627~\pm~61\mathrm{Mpc}\right)\left(\frac{r_{s}}{r_{s,fid}}\right)$. This is in agreement with recent work, and is our best-fit model to the SDSS DR7 MAIN data. We find that the correlation function from the MAIN galaxies cannot reject an $\Omega_m~=~1$ model in a cosmological ruler test, and the and the BAO peak is not pronounced enough to significantly reject a neutrino HDM model. However, the neutrino model is rejected by the non-linear form of the matter power spectrum, even though the magnetic version of the model may form galaxies by the present day

707-6 Amiodarone Decreases Ability of Baseline Ventricular Arrhythmia Severity to Predict Mortality

The Congestive Heart Failure Survival Trial of Antiarrhythmic Therapy (CHF-STAT) entered 633 high risk patients (pts) with ejection fraction (EF)≤40%, PVCs/hr≥10 on 24 hour Holter recording and on active vasodilator therapy. Pts were randomized to amiodarone or placebo. Despite marked ventricular arrhythmia suppression, overall mortality was the same for amiodarone and placebo treated pts. An analysis to identify groups at risk based on frequency or severity of ventricular arrhythmia at baseline for both placebo and amiodarone is as follows:PlaceboAmiodaroneM1pM1pPVCs < 30/hr4%14%> 30/hr19%<0.00219%NS (0.47)PVCs < median*11%16%> median21%<0.000319%NS (0.54)High EF, Low PVC*11%13%High PVC13%NS14%NS (0.48)Low EF, Low PVC*14%17%)High PVC28%<0.0523%)NS (0.48)VT≤3 events/24hr13%16%≥421%<0.00320%NS (0.43)M1 = first year mortality*High, Low = >, <, median, EF (26%) & PVCs/hr (128)While increased arrhythmia severity predicted increased mortality on placebo, it did not in patients subsequently assigned to amiodarone treatment. Amiodarone appears to counter the effect of increased arrhythmia severity on mortality

The seasonal variation of fucoidan within three species of brown macroalgae

Fucoidan is comprised of a fucose backbone with sulphate groups, whose variation is important to the functionality of the polysaccharide. The structure of fucoidan has been reported to vary according to species, season, location and maturity; however there is currently little published data to support this. Understanding the seasonal variation of fucoidan is important for industrial applications to identify optimum harvesting times and ensure consistent product composition. This study explores the seasonal variation of three species of brown macroalgae, Fucus serratus (FS), Fucus vesiculosus (FV) and Ascophyllum nodosum (AN), harvested monthly off the coast of Aberystwyth, UK. Average fucoidan content is 6.0, 9.8 and 8.0 wt% respectively for FS, FV and AN, with highest quantities extracted in autumn and lowest in spring. Fucose content, varied between 18 and 28, 26–39 and 35–46 wt% and sulphate content between 30 and 40, 9–35 and 6–22 wt% for FS, FV and AN respectively, with both fluctuating inversely to the total fucoidan content. Size exclusion chromatography (SEC) has provided insight into the structural differences between the species. Based on the molecular weight (MW) distribution, and in line with previous research, it is hypothesised that fucoidan in FS has a more complex structure, with a higher degree of associated sulphate ions than in FV and AN which have a simpler, linear structure with less associated sulphate ions

Flame spread across liquids

Recent reviews of our understanding of flame spread across liquids show that there are many unresolved issues regarding the phenomenology and causal mechanisms affecting ignition susceptibility, flame spread characteristics, and flame spread rates. One area of discrepancy is the effect of buoyancy in both the uniform and pulsating spread regimes. The approach we have taken to resolving the importance of buoyancy for these flames is: (1) normal gravity (1g) and microgravity (micro g) experiments; and (2) numerical modeling at different gravitational levels. Of special interest to this work, as discussed at the previous workshop, is the determination of whether, and under what conditions, pulsating spread occurs in micro g. Microgravity offers a unique ability to modify and control the gas-phase flow pattern by utilizing a forced air flow over the pool surface

Reuters Institute digital news report 2024

The thirteenth Digital News Report from the Reuters Institute for the Study of Journalism at the University of Oxford explores changes to the global news ecosystem based on a YouGov survey of over 95,000 online news consumers in 47 media markets. The report documents the declining importance of legacy social platforms such as Facebook and X for news discovery and consumption, while video formats and networks are becoming more popular. In a year that sees a record number of elections around the globe, concern about misinformation has risen further with worries about AI-generated content a contributory factor. Meanwhile, trust in the news remains low and selective news avoidance has risen again, against a backdrop of continuing conflicts in Gaza and Ukraine

Temperature Field During Flame Spread over Alcohol Pools: Measurements and Modelling

A principal difference between flame spread over solid fuels and over liquid fuels is, in the latter case, the presence of liquid-phase convection ahead of the leading edge of the flame. The details of the fluid dynamics and heat transfer mechanisms in both the pulsating and uniform flame spread regimes were heavily debated, without resolution, in the 1960s and 1970s; recently, research on flame spread over pools was reinvigorated by the advent of enhanced diagnostic techniques and computational power. Temperature fields in the liquid, which enable determination of the extent of preheating ahead of the flame, were determined previously by the use of thermocouples and repetitive tests, and suggested that the surface temperature does not decrease monotonically ahead of the pulsating flame front, but that there exists a surface temperature valley. Recent predictions support this suggestion. However, others' thermocouple measurements and the recent field measurements using Holographic Interferometry (HI) did not find a similar valley. In this work we examine the temperature field using Rainbow Schlieren Deflectometry (RSD), with a measurement threshold exceeding that of conventional interferometry by a factor of 20:1, for uniform and pulsating flame spread using propanol and butanol as fuels. This technique was not applied before to flame spread over liquid pools, except in some preliminary measurements reported earlier. Noting that HI is sensitive to the refractive index while RSD responds to refractive index gradients, and that these two techniques might therefore be difficult to compare, we utilized a numerical simulation, described below, to predict and compare both types of field for the uniform and pulsating spread regimes. The experimental data also allows a validation of the model at a level of detail greater than has been attempted before