The elusive role of scientific medicine in mortality decline: diphtheria in nineteenth- and early twentieth-century Philadelphia

The designation of the Klebs-Loeffler bacillus as the cause of diphtheria in the early 1890s and the subsequent development of the antitoxin treatment in the years immediately following were at the time and continue to be viewed as triumphs of scientific medicine. I focus on these two developments to illustrate the problems that arise in attempting to answer the questions regarding the role that changes in medical practice--in this case, the use of antitoxin as a cure--played in lowering death rates at the time. Changes in diagnostic techniques, the selection of cases to be included, and ultimately the agendas of the persons constructing them affected the numerators and denominators of these rates. The data suggest that the antitoxin had some effect on already declining diphtheria death rates, but because of changes in understandings of the disease and contemporaries' presentation of the data, the size of that effect and its role in mortality decline more generally elude us. Our analysis of the past depends on numbers that reflect not only changing treatments but also changing understandings of disease at the end of the nineteenth century.     

Rich–Poor Gap in Maternal Care

This paper examines the rich–poor gap in antenatal and delivery care in Northeast India on the basis of household economic well-being index constructed from household amenities, housing quality, consumer durables owned and assets. The study uses data on frequency of antenatal checks, iron folic supplementation, receiving two doses of tetanus toxoid injection and skill of delivery attendant from the Indian National Family Health Survey-II (1998–99). The finding reveals an unimaginably low level of maternal care in the region. Besides, there is evidence of concentration of women without adequate maternal care amongst the poorest economic strata. The need for region specific equitable maternal care services is suggested for the inaccessible northeastern region of India.     

Pore‐scale multiphase flow experiments in bead packs of variable wettability

The aim of this experimental study is to investigate the impact of wetting characteristics on multiphase flow, sweep efficiency, and residual fluid distribution in unconsolidated porous media. A sequence of oil and water injections was performed on bead packs with uniform porosity and permeability, but different wettability characteristics. Uniform and mixed‐wet bead packs with varying degree of wettability were fabricated to analyze how the residual saturation profiles and the distribution of fluid phases at the pore scale respond to changes in wettability. X‐ray microtomography was used to visualize and analyze the fluid distribution in each bead pack at the end of oil and brine injection. It was found that sweep efficiency was high for the uniform, strongly wetting glass bead pack. For the intermediate‐wet plastic bead pack, we observed evidence of viscous fingering resulting in degenerating sweep efficiency after water injection. In media with mixed wetting surfaces, the spatial distribution of wettability influenced the topology of the saturation profiles and resulted in larger quantities of disconnected fluid blobs. Results also showed that the average blob size was independent of the average residual saturation. In addition, the difference in saturation conditions preceding each injection affected sweep efficiency. The residual saturation after the 1st displacement was higher than the residual saturation after the 2nd displacement.     

Veterinary immunology as colonial science: method and quantification in the investigation of horsesickness in South Africa, C. 1905-1945

This article examines the practice of veterinary immunology in South Africa during the first half of the twentieth century through an analysis of research into a horsesickness vaccine at the Onderstepoort Veterinary Institute. From the early 1900s, Arnold Theiler prioritized research into horsesickness, by then defined as an insect-borne disease caused by an ultravisible virus. He succeeded in devising a means of prophylaxis using a simultaneous injection of infective blood and immune serum, but he discovered antigenically different strains of the virus, which could overcome the immunity produced by his treatment. The practical value of Theiler's methods was further limited by difficulties in standardizing the biological material used in immunization, the results of which remained too erratic for application on a large scale. No further advances were made until the 1930s, by which time Onderstepoort had been drawn more closely into international scientific networks. Using techniques derived from research into yellow fever in America and canine distemper in Britain, the Onderstepoort scientist Raymond Alexander invented a method of immunization that utilized the propagation of the horsesickness virus in the brains of mice. Alexander's methods, which were characterized by successful technical adaptation and innovation, depended upon methods of quantification first developed by Paul Ehrlich to standardize diphtheria antitoxin during the 1890s. During the 1940s, vaccination expanded rapidly in South Africa, and Onderstepoort later exported the vaccine and associated technology to other countries affected by horsesickness.     

Extracts from John Hennen's Principles of Military Surgery

Born in Castlebar, County Mayo, Ireland, John Hennen graduated in Edinburgh and had a career as an army surgeon, serving through the Peninsular War. His Principles of Military Surgery reached a third edition (posthumously) in 1829; his views on nerve-injuries, tetanus, head-injuries and syphilis are considered below.     

Extracts from John Hennen's Principles of Military Surgery

Born in Castlebar, County Mayo, Ireland, John Hennen graduated in Edinburgh and had a career as an army surgeon, serving through the Peninsular War. His Principles of Military Surgery reached a third edition (posthumously) in 1829; his views on nerve-injuries, tetanus, head-injuries and syphilis are considered below.     

On modeling of chemical stimulation of an enhanced geothermal system using a high pH solution with chelating agent

Dissolution of silica and calcite in the presence of a chelating agent (NTA) at a high pH was successfully demonstrated in laboratory experiments using a high-temperature flow reactor. (Note that the term 'silica' used here includes amorphous silica, quartz, and silicate glass bead.) The mineral dissolution and associated porosity enhancement in the experiments were reproduced by reactive transport modeling using TOUGHREACT. The chemical stimulation method was applied by numerical modeling to a field geothermal injection well system to investigate its effectiveness. Parameters applicable to the quartz monzodiorite unit at the Enhanced Geothermal Systems site at Desert Peak (Nevada) were used. Results indicate that the injection of a high pH chelating solution results in dissolution of both calcite and plagioclase, while avoiding precipitation of calcite at high temperature conditions. Consequently, reservoir porosity and permeability can be enhanced especially near the injection well. Injection at a lower temperature of 120°C (temperature is over 160°C in the base-case) results in a porosity increase that is smaller close to the injection point, but extends to a larger radial distance. A slower kinetic rate results in less aggressive mineral dissolution close to the injection point and larger extent along the flow path, which is favorable for chemical stimulation.     

Fluid injection and surface deformation at the KTB location: modelling of expected tilt effects

This investigation is indented to explore the relationship between changes in pore fluid pressure and deformation of the land surface induced by a large‐scale injection experiment at the KTB site. Deformation will be monitored by ASKANIA borehole tiltmeters at five locations. During the year 2003, a network of borehole tiltmeters was installed, data transmission links established and tested, and recording of tilt data started. Our first main interest was to receive data sets of all stations well before the injection experiment to start in May 2004, to be able to evaluate local site effects. Thus, the separation of injection‐induced effects will be more reliable. Principal 3D numerical modelling (poro‐elastic modelling and investigations, using the finite element method, FEM) of poro‐elastic behaviour showed that significant tilt amplitudes can be expected during controlled fluid injection. Observed deformation will be investigated within the framework of the fluid flow behaviour and resulting deformation. Two models have been used: a coupled hydro geomechanical finite element model (abaqus ) and, as a first step, also a multi‐layered poro‐elastic crust (poel ). With the numerical model two effects can be quantified: (i) the deformation of the upper crust (tilt measurements) and (ii) the spatial distribution and the changes of material properties in the KTB area. The main aim of the project is to improve the knowledge of coupled geomechanic–hydraulic processes and to quantify important parameters. Thus, the understanding of fracture‐dominated changes of the hydrogeological parameters will be enhanced, geomechanical parameter changes and the heterogeneity of the parameter field quantified. In addition, the induced stress field variation can be explained, which is believed to be mainly responsible for the increase of local seismic activity. Here, we introduce the tiltmeter array at the KTB site, the modelling for a poro‐elastic crust and the preliminary FEM modelling.     

Radio wave turbulent ‘absorption’ due to electron beam injections in the ionosphere

Considered is the collisionless damping of high-frequency radio waves in the ionospheric plasma perturbed by electron beams. Special attention is paid to the attenuation of telemetric signals, observed in the ARAKS experiment with intense electron beam injections, and to the ‘spike’ ionospheric absorption events. It is shown that these phenomena may be explained in terms of the nonlinear scattering of radio waves by plasma turbulence driven by electron beams and accompanied field-aligned currents.     

Real‐time quadrupole mass spectrometer analysis of gas in borehole fluid samples acquired using the U‐tube sampling methodology

Sampling of fluids in deep boreholes is challenging because of the necessity of minimizing external contamination and maintaining sample integrity during recovery. The U‐tube sampling methodology was developed to collect large volume, multiphase samples at in situ pressures. As a permanent or semi‐permanent installation, the U‐tube can be used for rapidly acquiring multiple samples or it may be installed for long‐term monitoring applications. The U‐tube was first deployed in Liberty County, TX to monitor crosswell CO₂ injection as part of the Frio CO₂ sequestration experiment. Analysis of gases (dissolved or separate phase) was performed in the field using a quadrupole mass spectrometer, which served as the basis for determining the arrival of the CO₂ plume. The presence of oxygen and argon in elevated concentrations, along with reduced methane concentration, indicates sample alteration caused by the introduction of surface fluids during borehole completion. Despite producing the well to eliminate non‐native fluids, measurements demonstrate that contamination persists until the immiscible CO₂ injection swept formation fluid into the observation wellbore.     

Pliocene sand injectites from a submarine lobe fringe during hydrocarbon migration and salt diapirism: a seismic example from the Lower Congo Basin

Large‐scale conical and saucer‐shaped sand injectites have been identified in the Upper Miocene sediments of the Lower Congo Basin. These structures are evidenced on the 3D high‐resolution seismic data at about 600 ms TWT (two‐way traveltime) beneath the seabed. The conical and saucer‐shaped anomalies range from 20 to 80 m in height, 50 to 300 m in diameter, and 10 to 20 ms TWT in thickness. They are located within a sedimentary interval of about 100 m in thickness and are aligned over 20 km in dip direction (NE‐SW), above the NW margin of an underlying Upper Miocene submarine fan. We have interpreted the conical and saucer‐shaped anomalies as upward‐emplaced sand injectites sourced from the Upper Miocene fan because of their discordant character, the postsedimentary uplifting of the sediments overlying the cones and saucer‐shaped bodies, the alignment with the lateral fringe of the Upper Miocene submarine fan, and the geological context. Sand injection dates from the Miocene–Pliocene transition (approximately 5.3 Ma). The prerequisite overpressure to the sand injection process may be due to the buoyancy effect of hydrocarbons accumulated in the margins of the fan. Additionally, overpressure could have been enhanced by the lateral transfer of fluids operating in the inclined margins of the lobe. The short duration of sand injection and the presence of many sandstone intrusions suggested that the process of injection was triggered by an event, likely due to a nearby fault displacement related to diapiric movements. This is the first time that sand injectites of seismic scale have been described from the Lower Congo Basin. The localized nature of these injectites has led to a change in the migration path of fluids through the sedimentary cover. Consequently, the sand intrusions are both evidence and vectors of fluid migration within the basin fill.     

Injection‐induced seismicity in Carbon and Emery Counties,central Utah

Utah is one of the top producers of oil and natural gas in the United States. Over the past 18 years, more than 4.2 billion gallons of wastewater from the petroleum industry has been injected into the Navajo Sandstone, Kayenta Formation, and Wingate Sandstone in Carbon and Emery Counties, central Utah, where seismicity has increased during the same period. Previous studies have attributed this seismicity to coal mining. Here, we present evidence for wastewater injection being a major cause of the increased seismicity. We show that, in the coal mining area, seismicity rate increased significantly 1–5 years following the wastewater injection, and the earthquakes, mostly with magnitudes <3.0, are concentrated in areas seismically active prior to the injection. Using simple analytical and numerical models, we show that the injection in central Utah can sufficiently raise pore pressure to trigger seismicity within 10–20 km of the injection wells, and the time needed for the diffusion of pore pressure may explain the observed lag of seismicity increase behind the commencement of injection. The b‐value of these earthquakes increased following the wastewater injection, which is consistent with these events being injection‐induced. We conclude that the marked increase in seismicity rate in central Utah is induced by both mining activity and wastewater injection, which raised pore pressure along preexisting faults.     

Fluid effect on hydraulic fracture propagation behavior: a comparison between water and supercritical CO2‐like fluid

The initiation of hydraulic fractures during fluid injection in deep formations can be either engineered or induced unintentionally. Upon injection of CO₂, the pore fluids in deep formations can be changed from oil/saline water to CO₂ or CO₂ dominated. The type of fluid is important not only because the fluid must fracture the rock, but also because rocks saturated with different pore fluids behave differently. We investigated the influence of fluid properties on fracture propagation behavior by using the cohesive zone model in conjunction with a poroelasticity model. Simulation results indicate that the pore pressure fields are very different for different pore fluids even when the initial field conditions and injection schemes (rate and time) are kept the same. Low viscosity fluids with properties of supercritical CO₂ will create relatively thin and much shorter fractures in comparison with fluids exhibiting properties of water under similar injection schemes. Two significant times are recognized during fracture propagation: the time at which a crack ceases opening and the later time point at which a crack ceases propagating. These times are very different for different fluids. Both fluid compressibility and viscosity influence fracture propagation, with viscosity being the more important property. Viscosity can greatly affect hydraulic conductivity and the leak‐off coefficient. This analysis assumes the in‐situ pore fluid and injected fluid are the same and the pore space is 100% saturated by that fluid at the beginning of the simulation.     

Modelling European Regional Policy 2007–2013: Applied General Equilibrium Analysis of the Economic Impact on the Madrid Region

The main purpose of this study was to present an applied general equilibrium model to the economy of the Madrid region. The model developed is considered a neoclassical version of the Walrasian equilibrium, modelling production sectors on perfect competition, full use of production factors and the clearing of all markets of goods. The model thus enables the second objective of the study: to estimate the impact of the 2007–2013 Structural Funds received on the economy of the Madrid region. The effects resulting from the injection of the funds are quantified by simulations performed using the developed model. This analysis of the quantification of effects is extremely important, as the priority objectives of the European Regional Policy have changed with respect to the previous period. In the current operational programme, the Madrid region comes under the regional competitiveness objective, which focuses on the priorities of innovation, research, the information society and business development. The sectors that have traditionally benefited, mainly infrastructure, therefore give way to others and the injection of funds into the Madrid economy is to be through other areas. In addition, there has been a reduction of the European aid received by our Region, as compared with previous Programmes.     

Exploring the potential linkages between oil‐field brine reinjection,crystalline basement permeability,and triggered seismicity for the Dagger Draw Oil field,southeastern New Mexico,USA, using hydrologic modeling

We used hydrologic models to explore the potential linkages between oil‐field brine reinjection and increases in earthquake frequency (up to M_d 3.26) in southeastern New Mexico and to assess different injection management scenarios aimed at reducing the risk of triggered seismicity. Our analysis focuses on saline water reinjection into the basal Ellenburger Group beneath the Dagger Draw Oil field, Permian Basin. Increased seismic frequency (>M_d 2) began in 2001, 5 years after peak injection, at an average depth of 11 km within the basement 15 km to the west of the reinjection wells. We considered several scenarios including assigning an effective or bulk permeability value to the crystalline basement, including a conductive fault zone surrounded by tighter crystalline basement rocks, and allowing permeability to decay with depth. We initially adopted a 7 m (0.07 MPa) head increase as the threshold for triggered seismicity. Only two scenarios produced excess heads of 7m five years after peak injection. In the first, a hydraulic diffusivity of 0.1 m² s^?1 was assigned to the crystalline basement. In the second, a hydraulic diffusivity of 0.3 m² s^?1 was assigned to a conductive fault zone. If we had considered a wider range of threshold excess heads to be between 1 and 60 m, then the range of acceptable hydraulic diffusivities would have increased (between 0.1–0.01 m² s^?1 and 1–0.1 m² s^?1 for the bulk and fault zone scenarios, respectively). A permeability–depth decay model would have also satisfied the 5‐year time lag criterion. We also tested several injection management scenarios including redistributing injection volumes between various wells and lowering the total volume of injected fluids. Scenarios that reduced computed excess heads by over 50% within the crystalline basement resulted from reducing the total volume of reinjected fluids by a factor of 2 or more.     

The El Chichon volcanic cloud in the stratosphere: lidar observation at Fukuoka and numerical simulation

The stratospheric volcanic cloud from the eruption.of El Chichon, Mexico, on 4 April 1982 was observed routinely by a Nd: YAG lidar system from 18 April 1982 at Kyushu University, Fukuoka, Japan. The observed layers of the cloud above 20 km were in the easterly wind region and those below 20 km were in the westerly region. The main part of the cloud mass was in the upper layer. This upper layer broadened slowly until September 1982, then broadened rapidly and merged with the lower layer as the easterly wind changed to the westerly wind. The vertical eddy diffusion coefficient estimated from the broadening of the upper layer was much smaller than the value usually used in the one-dimensional model calculation of chemical components until September and subsequently remained at about the same value. The increase of the integrated backscattering coefficient (IBC) was about two orders of magnitude larger than the largest increase after volcanic injections for the last 10 years. The IBC reached a maximum value on 3 May and gradually decreased until August 1982, then re-increased until December 1982. The IBC between December 1982 and February 1983 was about the same value as in May 1982. Using the one-dimensional stratospheric sulfate aerosol model simulations it was concluded that to explain the broadening of the upper layer an eddy diffusion coefficient of about 10²cm²s^-1 would be needed in the easterly wind region in summer. It was also concluded that the IBC re-increase was caused after advective horizontal transport from lower to higher latitudes by chemical reactions within the upper layer without meridional diffusion during summer and that the transport was controlled by nucleation, which gives rise to small particles, a decreasing settling velocity of the volcanic cloud and then the cloud being less affected by horizontal transport.     

Does Solidarity Pay? The Case of the Small Enterprise Foundation,South Africa

This article argues that the costs of lending through solidarity groups are high. This is explained by the nature of groups: groups are not a forum for contractual exchange, but are costly institutions built on social capital. The costs of group formation and interaction outweigh the benefits of high repayment rates associated with group control. Supposedly sustainable group-lenders often depend on large injections of subsidized loans or capital from donors. This is usually ignored in mainstream literature which does not pay sufficient attention to the operational costs of credit extension. The argument is illustrated with a study of the Small Enterprise Foundation, South Africa, which shows a contradiction between staff-intensive, personalized lending technology and sufficient cost-recovery.     

La mobilité forcée des personnes utilisatrices de drogue par injection et inhalation en situation d'itinérance à Montréal

This article focuses on the various actors in the urban setting who contribute to the increase in the forced mobility of homeless injection drug users and crack smokers in Montréal, Canada. The objective is to analyze who these actors are and how they contribute to increasing this forced mobility from the perspective of homeless injection drug users and crack smokers in relation to three needs : basic needs, acquisition of financial resources, and drug use. One hundred and six semi-structured interviews were conducted among this population. The results indicate that various actors—police officers, community organization, peers, municipal administration, storekeepers, and residents—contribute to the forced mobility of this population in their daily activities. As for their needs, it is when they use drugs, sleep, or loiter that they are more likely to experience events of forced mobility. Police officers are by far the actors who contribute the most to this, often in a repressive way. The role of the municipality is also a determining factor in the daily activities of homeless injection drug users and crack smokers.     

Application of boron isotopes to the understanding of fluid–rock interactions in a hydrothermally stimulated oil reservoir in the Alberta Basin, Canada

Boron isotope ratios of reservoir minerals and fluids can be a useful geothermometer and monitor of fluid–rock interactions. In Cold Lake oil sands of northern Alberta, there is a large variation in δ¹¹B of the produced waters generated during steam injection and recovery of oil and water. The higher temperature waters (～ 200 °C) have isotopically light δ¹¹B values (+ 3‰ to + 14‰) and high B contents (～150 p.p.m.). It is inferred that the range of δ¹¹B values of the hydrothermal fluids results from reaction with the reservoir rock, and is a function of the temperature of the fluid–rock interaction. The distinct B geochemistry of the produced waters can be used to show that there is no detectable mixing of the oil recovery waters with the regional formation waters or shallow groundwater aquifers containing potable water. Examination of B isotope ratios of reservoir minerals, before and after steam injection, allows the evaluation of sources of B in the reservoir. The only significant phase containing B is pumice. It shows generally positive δ¹¹B values before steam injection and negative values after steam, with δ¹¹B as low as ? 28‰. Other possibly reactive phases include clay minerals and organic matter, but their abundance is not great enough to impact on the isotopic composition of the produced waters. This information makes it possible to evaluate the boron isotope fractionation equation derived from experimental data ( Williams LB (2000) Boron isotope geochemistry during burial diagenesis. PhD Dissertation. The University of Calgary, Alberta, Canada; Williams LB, Hervig RL, Holloway JR, Hutcheon I (2001a) Boron isotope geochemistry during diagenesis: Part 1. Experimental determination of fractionation during illitization of smectite. Geochimica et Cosmochimica Acta, in press). The results show that the fractionation curve predicts the difference between δ¹¹B of the pumice and hydrothermal fluids in the Cold Lake reservoir. This not only indicates that the reservoir fluids have approached boron isotope equilibrium with the reservoir rock, but also shows that B isotopes provide a useful geothermometer for hydrothermally stimulated oil reservoirs.