bluuebunny/crossref_metadata_2025 huggingface dataset:
Subduction zone retreat and recent tectonics of the South Island of New Zealand
Authors: Waschbusch Paula , Batt Geoff , Beaumont Christopher
Published: February 2004

The central South Island of New Zealand is a zone of recent oblique continent‐continent convergence between the Australian and Pacific plates. Convergence is localized on the Alpine Fault, and its broader expression has created the Southern Alps. We propose that many of the strike variations in orogenic style of this zone (e.g., physical extent and style of crustal shortening, argon release patterns, and fission track observations) can be explained by differential amounts of subduction zone retreat beneath the orogen. The observed patterns suggest greater eastward retreat of the subducting Pacific plate in the south than in the north. To support this hypothesis, we compare geodynamic models having varying amounts of subduction zone retreat with geological and geophysical observations. Incorporating subduction zone retreat not only creates tectonic variations similar to those observed but also provides a geodynamically consistent explanation for the size, shape, and location of the broad negative Bouguer gravity anomaly associated with the orogen. In addition, these geodynamic models suggest that subduction zone retreat may result in local topographic lows which may serve as preferential locations for the formation of intermontane basins and associated lakes, possibly explaining the chain of South Island lakes. Our preferred interpretation of the geologic history of the central South Island convergence has an initial phase of Pacific plate lower crust and mantle subduction (underthrusting) with no retreat followed by a second phase of subduction zone retreat in the southern part of the zone. This retreat may be a consequence of oblique convergence, which creates interference beneath Fiordland between the south east dipping Australian plate and the underthrust west dipping Pacific plate to the north and forces retreat.
Wide‐angle seismic constraints on the evolution of the deep San Andreas plate boundary by Mendocino triple junction migration
Authors: Hole J. A. , Beaudoin B. C. , Henstock T. J.
Published: February 2004

Recent, wide‐angle seismic observations that constrain the existence and structure of a mafic layer in the lower crust place strong constraints on the evolution of the San Andreas plate boundary system in northern and central California. Northward migration of the Mendocino Triple Junction and the subducted Juan de Fuca lithospheric slab creates a gap under the continent in the new strike‐slip system. This gap must be filled by either asthenospheric upwelling or a northward migrating slab attached to the Pacific plate. Both processes emplace a mafic layer, either magmatic underplating or oceanic crust, beneath the California Coast Ranges. A slab of oceanic lithosphere attached to the Pacific plate is inconsistent with the seismic observation that the strike‐slip faults cut through the mafic layer to the mantle, detaching the layer from the Pacific plate. The layer could only be attached to the Pacific plate if large vertical offsets and other complex structures observed beneath several strike‐slip faults are original oceanic structures that are not caused by the faults. Otherwise, if oceanic slabs exist beneath California, they do not migrate north to fill the growing slab gap. The extreme heat pulse created by asthenospheric upwelling is inconsistent with several constraints from the seismic data, including a shallower depth to the slab gap than is predicted by heat flow models, seismic velocity and structure that are inconsistent with melting or metamorphism of the overlying silicic crust, and a high seismic velocity in the upper mantle. Yet either the Pacific slab model or the asthenospheric upwelling model must be correct. While the mafic material in the lower crust could have been emplaced prior to triple junction migration, the deeper slab gap must still be filled. A preexisting mafic layer does not reduce the inconsistencies of the Pacific slab model. Such material could, however, compensate for the decrease in mafic magma that would be produced if asthenospheric upwelling occurred at a lower temperature. These low temperatures, however, may be inconsistent with asthenospheric rheology.
Parameter estimation using artificial neural network and genetic algorithm for free‐product migration and recovery
Authors: Morshed Jahangir , Kaluarachchi Jagath J.
Published: February 2004

Artificial neural network (ANN) is considered to be a universal function approximator, and genetic algorithm (GA) is considered to be a robust optimization technique. As such, ANN regression analysis and ANN‐GA optimization techniques can be used to perform inverse groundwater modeling for parameter estimation. In this manuscript the applicability of these two techniques in solving an inverse problem related to a light‐hydrocarbon‐contaminated site is assessed. The critical parameters to be evaluated are grain‐size distribution index α and saturated hydraulic conductivity of water Ksw, since these parameters control free‐product volume predictions and flow. A set of published data corresponding to a light‐hydrocarbon‐contaminated unconfined aquifer was used as the base case to determine the applicability of these methods under a variety of scenarios. Using limited monitoring‐ and recovery‐well data under homogeneous and heterogeneous conditions, the critical parameters were evaluated. The results were used to determine the relative effectiveness of each method and corresponding limitations. The results of the work suggested that ANN regression analysis has limited utility, especially with heterogeneous soils, whereas the ANN‐GA optimization can provide superior results with better computational efficiency. Finally, a general guideline for solving inverse problems using the two techniques is outlined.
Stream surfaces in two‐dimensional and three‐dimensional divergence‐free flows
Authors: Steward David R.
Published: February 2004

It is demonstrated that two‐dimensional flows and three‐dimensional flows have fundamentally different influences on stream surfaces. An element that generates a two‐dimensional flow only can affect the angle of intersection between two stream surfaces locally; an element that generates a three‐dimensional flow may affect this angle regionally. One consequence is that stream functions for three‐dimensional flows may not in general be chosen such that their basis vectors are everywhere mutually orthogonal. Another consequence is that the deformation of stream surfaces produced by a three‐dimensional element does not approach that produced by a two‐dimensional element at large distances from the element; a two‐dimensional model cannot reproduce stream surfaces that occur in a three‐dimensional flow.
Skin temperature perturbations induced by surface layer turbulence above a grass surface
Authors: Katul Gabriel G. , Schieldge John , Hsieh Cheng‐I , Vidakovic Brani
Published: February 2004

High‐frequency (5 Hz) atmospheric surface layer (ASL) turbulent velocity (u′) and infrared skin temperature perturbations (T′s) were measured above a grass‐covered forest clearing and analyzed for cloud free conditions. These measurements were used to investigate mechanisms responsible for the production of large short‐lived T′s perturbations caused by rapid excursions in u′. To quantify the effects of u′ on rapid surface cooling, wavelet spectra of u′ and T′s and cospectra of u′T′s were computed. The u′ wavelet power spectra were then analyzed using Townsend's [1961, 1976] hypothesis. Townsend's hypothesis states that ASL eddy motion can be decomposed into an active component, which is a function of the ground shear stress (u*) and height (z) above the zero plane displacement, and an inactive component, which is produced in the atmospheric boundary layer (ABL) outer region. A −1 power law in the u′ power spectrum was used as a signature for inactive eddy motion. Therefore the −1 power law was used to identify wavenumber ranges (about 1.5 decades) associated with inactive eddy motion. The measured T′s wavelet spectra and u′T′s cospectra identified with this wavenumber range demonstrate that much of the T′s energy and 〈u′T′s〉 are due to inactive eddy motion, where the angle brackets indicate time averaging. Hence, in contrast to the laboratory experiments of Owen and Thomson [1963], it is argued that skin temperature perturbations at the canopy‐atmosphere interface of a grass‐covered surface (small thermal inertia) are strongly dependent on the inactive eddy motion produced in the outer layer of the ABL.
Stochastic analysis of steady‐state unsaturated flow in heterogeneous media: Comparison of the Brooks‐Corey and Gardner‐Russo Models
Authors: Zhang Dongxiao , Wallstrom T. C. , Winter C. L.
Published: February 2004

Existing stochastic models of unsaturated flow and transport are usually developed using the simple Gardner‐Russo constitutive relationship though it is generally accepted that the more complex van Genuchten and Brooks‐Corey relationships may perform better in describing experimental data. In this paper, we develop first‐order stochastic models for gravity‐dominated flow in second‐order stationary media with both the Brooks‐Corey and the Gardner‐Russo constitutive relationships. These models also account for the spatial variability in effective water content, while the spatial variability is generally neglected in most existing stochastic models. Analytical solutions are obtained for the case of one‐dimensional gravity‐dominated flow. On the basis of the solutions, we illustrate the differences between results from these two constitutive models through some one‐dimensional examples. It is found that the impacts of the constitutive models on the statistical moments of suction head, effective water content, unsaturated hydraulic conductivity, and velocity depend on the saturation ranges. For example, the mean head and the mean effective water content for the Brooks‐Corey model differ in a great manner with their counterparts for the Gardner‐Russo model near the dry and wet limits while the differences are small at the intermediate range of saturation. This finding is confirmed with some two‐dimensional examples. It is also found that the Brook‐Corey model has certain advantages over the Gardner‐Russo model in analyzing unsaturated flow in heterogeneous media. For example, the stochastic model developed based on the Brooks‐Corey function requires the coefficient of variation of head and soil parameter “αBC” to be small (≪1), whereas that based on the Gardner‐Russo function assumes the one‐point cross covariance of head and OLGR to be small (≪1). Illustrative examples reveal that the latter condition may be violated because the one‐point covariance is found to increase rapidly to beyond unity as the soil becomes dry, whereas the former may be readily satisfied.
Sources and mobility of arsenic in the Salt River Watershed, Arizona
Authors: Baker Lawrence A. , Qureshi Taqueer M. , Wyman Max M.
Published: February 2004

Sources and mobility of arsenic in the upper Salt River (Arizona) were examined using a 6‐year long mass balance for nine U.S. Geological Survey chemical monitoring stations, a more spatially intensive low‐flow synoptic study, and laboratory leaching studies. An arsenic‐rich lacustrine deposit (the Verde Formation) comprised only 4% of the watershed but contributed a third of the total watershed arsenic loading. Export from this part of the watershed was 10–20 times higher than export from most other parts of the watershed. Laboratory experiments confirmed the high As leaching potential for this formation. Although elevated levels of As were found in a geothermal spring and in several mine seeps, these sources of arsenic contributed little to the overall As loading. About 15% of the As loading from the upper Verde River watershed was retained by a two‐reservoir system. Sedimentation and chemical precipitation appear to be likely mechanisms of As retention in the reservoirs.
Unsaturated zone processes and the hydrologic response of a steep, unchanneled catchment
Authors: Torres Raymond , Dietrich William E. , Montgomery David R. , Anderson Suzanne P. , Loague Keith
Published: February 2004

As part of a larger, collaborative study, we conducted field experiments to investigate how rainfall signals propagate through an unsaturated soil profile, leading to a rapid pore pressure response and slope instability. We sprinkler‐irrigated an entire, unchanneled headwater basin in the steep, humid Oregon Coast Range, and we drove the system to quasi steady state as indicated by tensiometers, piezometers, and discharge. During initial wetting some of the deeper tensiometers responded before the arrival of an advancing head gradient front. With continued irrigation most tensiometers attained near‐zero pressure heads before most piezometers responded fully, and a stable unsaturated flow field preceded the development of a stable saturated flow field. Steady discharge occurred after the last piezometer reached steady state. With the onset of steady discharge the unsaturated zone, saturated zone, and discharge became delicately linked, and a spike increase in rain intensity led to a response in the saturated zone and discharge much faster than could have happened through advection alone. We propose that the rain spike produced a slight pressure wave that traveled relatively rapidly through the unsaturated zone, where it caused a large change in hydraulic conductivity and the rapid effusion of stored soil water. An important control on the hydrologic response of this catchment lies with the soil‐water retention curve. In general, below pressure heads of about −0.05 m, soil‐water contents change slightly with changes in pressure head, but above −0.05 m the soil‐water content is highly variable. Minor rainstorms upon a wet soil can produce slight changes in pressure head and corresponding large changes in soil‐water content, giving rise to the passage of pressure waves in response to increased rain intensity and a relatively rapid response in the unsaturated zone. This rapid unsaturated zone response led to a rapid rise in the saturated zone, and it may be the underlying mechanism enabling short bursts of rain to cause slope instability.
Modeling phosphorus trapping in wetlands using nonparametric Bayesian Regression
Authors: Qian Song S. , Reckhow Kenneth H.
Published: February 2004

Phosphorus‐enriched agricultural runoff from the Everglades Agriculture Area is believed to have caused ecological changes in the northern part of the Everglades wetlands. A number of efforts have been made to assess the effectiveness of using constructed wetlands as a means of phosphorus removal from the agricultural runoff. The objective of this study is to develop a predictive model for the total phosphorus effluent concentration of an Everglades wetland that has received this runoff for over 20 years. We used Bayesian nonparametric regression to develop a predictive model combining information from an Everglades wetland data set and a cross‐sectional data set. The prior model was based on the cross‐sectional data set and expert opinion; this prior model, when combined with data from the Everglades wetland, yielded the posterior model, which can be used to (1) estimate the probability of an outflow concentration standard violation and (2) provide the posterior distributions of effluent concentrations at different loading rates and water levels. The primary use of this model is to support decision making in sizing the proposed constructed wetlands in south Florida as well as keeping a practical management strategy.
A new two‐step stochastic modeling approach: Application to water transport in a spatially variable unsaturated soil
Authors: Loll Per , Moldrup Per
Published: February 2004

A new two‐step stochastic modeling approach based on stochastic parameter inputs to a deterministic model system is presented. Step I combines a Stratified sampling scheme with a deterministic model to establish a deterministic response surface (DRS). Step II combines a Monte Carlo sampling scheme with the DRS to establish the stochastic model response. The new two‐step approach is demonstrated on a one‐dimensional unsaturated water flow problem at field scale with a dynamic surface flux and two spatially variable and interdependent parameters: The Campbell [1974] soil water retention parameter (b) and the saturated hydraulic conductivity (Ks). The new two‐step stochastic modeling approach provides a highly time efficient way to analyze consequences of uncertainties in stochastic parameter input at field scale. The new two‐step approach is competitive in analyzing problems with time consuming deterministic model runs where the stochastic problem can be adequately described by up to two spatially variable parameters.
Agriculture and endangered species: An analysis of trade‐offs in the Klamath Basin, Oregon
Authors: Adams Richard M. , Cho Seong Hoon
Published: February 2004

In 1988 the U.S. Fish and Wildlife Service, under provisions of the Endangered Species Act (ESA), declared two fish species in the Klamath Basin as endangered and mandated minimum water levels in Upper Klamath Lake to protect habitat for these species. The lake is the key hydrological feature of the basin; inflows and lake storage provide irrigation water for over 220,000 acres (890.34 km2) in the area. The ESA lake level restrictions reduced both expected average irrigation water supplies and the capacity of the lake to stabilize water supplies during drought cycles. This research explores trade‐offs between lake levels for fish protection and the profits of farmers under a range of lake level and farmer adaptations. The results indicate that farmers can adjust their irrigation decisions to offset some of the water supply reductions. However, there are costs to agriculture. The expected average cost of maintaining ESA lake levels (estimated over 73 water years) is approximately $2 million annually; for severe drought years, annual costs exceed $15 million or about 60% of average farm profits. The steeply increasing marginal cost curve shows an increasingly heavier economic burden to agriculture as lake level restrictions increase.
Carbon dioxide respiration in the deep vadose zone: Implications for groundwater age dating
Authors: Bacon Diana Holford , Keller C. Kent
Published: February 2004

In the deep vadose zone at the Dalmeny site, subsurface gas samples were collected and analyzed for CO2 and the 13C and 14C ratios of that CO2. High concentrations of CO2 depleted in 14C near the water table necessitate the use of an open‐system model of calcite dissolution to match observed dissolved inorganic carbon 14C ratios just below the water table. Groundwater age‐dating models assuming closed‐system calcite dissolution predict incorrect groundwater age dates at the Dalmeny site. These results and our field observations suggest that such errors may generally occur where deep‐vadose generation of nonmodern CO2 is not accounted for in groundwater age‐dating exercises.
Incorporating respondent uncertainty when estimating willingness to pay for protecting critical habitat for threatened and endangered fish
Authors: Ekstrand Earl R. , Loomis John
Published: February 2004

A comparison of the standard dichotomous choice contingent valuation model to alternative modifications that explicitly incorporate respondent uncertainty is performed to estimate economic benefits of protecting critical habitat for nine threatened and endangered fish species living in the Colorado, Green, and Rio Grande River basins. The standard dichotomous choice contingent valuation model estimated a value of $268 per household, which was compared to values ranging from $50 to $330, depending on how respondent uncertainty was explicitly incorporated into the dichotomous choice model. For this data set, incorporating respondent uncertainty had the effect of increasing the goodness of fit and decreasing the standard error of estimated willingness to pay in only one of five models tested.
Modeling of transport and seepage in effluent‐dominated streams
Authors: Berestov A. L. , Fernando H. J. S. , Fox P.
Published: February 2004

We describe the development and potential applications of a new stream water quality model that can be operated in either steady or unsteady modes. The model predicts the seepage flow during the time when both the flow in the stream basin and the input waste loads are variable. It is applied to the case of wastewater discharge into the Salt River from the 91st Avenue wastewater treatment plant of Phoenix, Arizona. The model simulates variable flow discharge from the treatment plant and periodic drying of the clogging layer, which influence infiltration rates at the stream banks. The ultimate aim is to couple the flow model with a riparian vegetation model to predict the ecosystem response to unsteady, effluent‐dominated stream dynamics. The model results will also be useful for resource managers to gain a better understanding of the dynamics of effluent‐dominated systems.
Dual‐energy synchrotron X ray measurements of rapid soil density and water content changes in swelling soils during infiltration
Authors: Garnier Patricia , Angulo‐Jaramillo Rafael , DiCarlo David A. , Bauters Tim W. J. , Darnault Christophe J. G. , Steenhis Tammo S. , Parlange J.‐Yves , Baveye Philippe
Published: February 2004

Understanding soil swelling is hampered by the difficulty of simultaneously measuring water content and bulk density. A number of studies have used dual‐energy gamma rays to investigate soil swelling. The long counting time of this technique makes it impracticable for studying the rapid changes in moisture content and soil swelling shortly after infiltration is initiated. In this paper, we use the dual‐energy synchrotron X ray to measure, for the first time, the water content and bulk density changes during the fast, initial phase of the swelling process. Ponded infiltration experiments were performed with two soils: a bentonite‐sand mixture and a vertisol. Swelling curves and hydraulic diffusivity were determined. Deformation was very rapid immediately after water application and then became progressively slower. The hydraulic diffusivity decreased with time, which can partially explain the very rapid decrease in infiltration rates observed in the field.
Retaking sleeping sickness control in Angola
Authors: Abel Paulo M. , Kiala Godi , Lôa Vanda , Behrend Markus , Musolf Jens , Fleischmann Hanne , Théophile Josénando , Krishna Sanjeev , Stich August
Published: January 2004

Africa is severely affected by a resurgence of human African trypanosomiasis (HAT) at epidemic proportions. We report the results of the first 5 years of a HAT control programme in northern Angola run by the non‐governmental organization (NGO) ANGOTRIP. In the period between 1996 and 2001, 13 426 patients were screened for HAT. The mortality rate of patients in stage II who were treated with melarsoprol fell from 7.5% to 2.9%, possibly as a result of training and the standardization of treatment protocols. A total of 191 578 people in three provinces of Angola were screened for HAT. Vector control activities were initiated using Lancien traps. Our experiences reflect the connection between war and the increasing incidence of disease, but also demonstrate that HAT control is possible by dedicated NGOs in close cooperation with national institutions even under extremely difficult circumstances.
Adherence to the combination of sulphadoxine–pyrimethamine and artesunate in the Maheba refugee settlement, Zambia
Authors: Depoortere Evelyn , Guthmann Jean‐Paul , Sipilanyambe Naawa , Nkandu Esther , Fermon Florence , Balkan Suna , Legros Dominique
Published: January 2004

Artemisinin‐based combination therapy (ACT) is one strategy recommended to increase cure rates in malaria and to contain resistance to Plasmodium falciparum. In the Maheba refugee settlement, children aged 5 years or younger with a confirmed diagnosis of uncomplicated falciparum malaria are treated with the combination of sulphadoxine–pyrimethamine (1 day) and artesunate (3 days). To measure treatment adherence, home visits were carried out the day after the last treatment dose. Patients who had any treatment dose left were considered certainly non‐adherent. Other patients’ classification was based on the answers to the questionnaire: patients whose caretakers stated the child had received the treatment regimen exactly as prescribed were considered probably adherent; all other patients were considered probably non‐adherent. Reasons for non‐adherence were assessed. We found 21.2% (95% CI [15.0–28.4]) of the patients to be certainly non‐adherent, 39.4% (95% CI [31.6–47.6]) probably non‐adherent, and 39.4% (95% CI [31.6–47.6]) probably adherent. Insufficient explanation by the dispenser was identified as an important reason for non‐adherence. When considering the use of ACT, the issue of patient adherence remains challenging. However, it should not be used as an argument against the introduction of ACT. For these treatment regimens to remain efficacious on a long‐term basis, specific and locally adapted strategies need to be implemented to ensure completion of the treatment.
Soluble transferrin receptor in Aboriginal children with a high prevalence of iron deficiency and infection
Authors: Ritchie B. , McNeil Y. , Brewster D. R.
Published: January 2004

Objectives  Aboriginal children in tropical Australia have a high prevalence of both iron deficiency and acute infections, making it difficult to differentiate their relative contributions to anaemia. The aims of this study were to compare soluble transferrin receptor with ferritin in iron deficiency anaemia (IDA), and to examine how best to distinguish the effect of iron deficiency from infection on anaemia.

Methods  We conducted a prospective study of 228 admissions to Royal Darwin Hospital in children from 6 to 60 months of age. Transferrin receptor concentrations were measured by a particle‐enhanced immunoturbidimetric assay and ferritin by a microparticle enzyme immunoassay.

Results  On multiple regression, the best explanatory variables for haemoglobin differences (r2 = 33.7%, P < 0.001) were mean corpuscular volume (MCV), red cell distribution width (RDW) and C‐reactive protein (CRP); whereas transferrin receptor and ferritin were not significant (P > 0.4). Using ≥2 abnormal indices (MCV, RDW, blood film) + haemoglobin <110 g/l as the reference standard for IDA, transferrin receptor produced a higher area under the curve on receiver operating characteristic curve analysis than ferritin (0.79 vs. 0.64, P < 0.001) or the transferrin receptor–ferritin index (0.77). On logistic regression, the effect of acute infection (CRP) on haemoglobin was significant (P < 0.001) at cut‐offs of 105 and 110 g/l, but not at 100 g/l when only iron deficiency indicators (MCV, RDW, blood film) were significant.

Conclusions  Transferrin receptor does not significantly improve the diagnosis of anaemia (iron deficiency vs. infection) over full blood count and CRP, but in settings with a high burden of infectious diseases and iron deficiency, it is a more reliable adjunctive measure of iron status than ferritin.
Does increased general schooling protect against HIV infection? A study in four African cities
Authors: Glynn Judith R. , Caraël Michel , Buvé Anne , Anagonou Séverin , Zekeng Léopold , Kahindo Maina , Musonda Rosemary ,   for the Study Group on Heterogeneity of HIV Epidemics in African Cities
Published: January 2004

Background  The association between educational attainment and risk of HIV infection varies between populations and over time. Earlier studies in sub‐Saharan Africa have found that those with more education are at increased risk of HIV infection.

Methods  We investigated the associations between general schooling and both HIV and herpes simplex‐2 (HSV‐2) infection using data from the multicentre study on factors determining the differential spread of HIV in four African cities. Cross‐sectional general population studies were conducted in 1997–1998 in Cotonou (Benin), Yaoundé (Cameroon), Kisumu (Kenya), and Ndola (Zambia), including about 2000 adults in each city.

Results  There was no association between schooling and HIV infection in men or women in Kisumu or Ndola. Women in Yaoundé and men in Cotonou, with more schooling, were less likely to be HIV positive. These associations persisted after adjusting for sociodemographic factors. Similar trends in men in Yaoundé and women in Cotonou were not statistically significant. Increased schooling was associated with significantly decreased risk of HSV‐2 infection in women in Kisumu and Ndola and men in Cotonou. In all the cities those with more education tended to report less risky sexual behaviour.

Conclusions  There was no evidence of an increased risk of HIV infection associated with education as seen in earlier studies. In each city there was some evidence of lower HIV or HSV‐2 infection rates and less risky sexual behaviour associated with increased education levels. The most educated may be responding more readily to health education programmes. The challenge is to extend this to the rest of the population.
Lay diagnosis of causes of death for monitoring AIDS mortality in Addis Ababa, Ethiopia
Authors: Araya Tekebash , Reniers Georges , Schaap Ab , Kebede Derege , Kumie Abera , Nagelkerke Nico , Coutinho Roel , Sanders Eduard
Published: January 2004

Lay diagnoses of death collected at burial sites were validated against two ‘gold standards’: the hospital discharge diagnosis of causes of death obtained by a surveillance of hospital deaths (including autopsy results) and the physician review of verbal autopsies (VAs) that were carried out for a sample of cemetery records. The diagnostic indicators of the lay diagnoses were then used to provide estimates of the share of AIDS‐attribuTable mortality. The verbal autopsy results provide an independent estimate of the percentage of AIDS deaths. From a total of 21 274 burial records, 2546 hospital discharge diagnoses, 1480 outcomes of autopsies and 200 adult verbal autopsies were gathered over a period of 1 year starting from February 2001. Independent of the gold standard, lay diagnoses such as lung disease and cold have a specificity of about 90% and a combined sensitivity of about 55% in determining AIDS mortality. Without a significant loss in specificity, the sensitivity increases to 60–65% when diarrhoea, TB, herpes zoster and mental or nerve problem are included. We thus conclude that even in the presence of a reluctance to talk of HIV/AIDS, lay diagnosis of causes of death can be used for monitoring AIDS mortality. Lung disease and cold, in particular, have become well‐known euphemisms for AIDS in the community. The share of AIDS deaths in the adult population (20–54) is estimated at 68%, without noticeable differences between men and women. Our results confirm the high impact of HIV/AIDS on mortality as was estimated by epidemiological projections for Addis Ababa.
Die Wertigkeit der Melanomnachsorge  aus der Patientenperspektive
Authors: Nashan Dorothée , Kirschner Franz , Strittmatter Gerhard , Hirche Frank , Hensen Peter , Loquai Carmen , Mauch Cornelia
Published: February 2004

Hintergrund: In der ambulanten Melanomnachsorge ist in 20 % der Fälle mit einem Progreß der Erkrankung bei primär erscheinungsfreien Patienten zu rechnen. Eine für Betroffene beängstigend hohe Zahl. Auf Grund anstehender Modifikationen der Melanomnachsorge sollten die Ausführung und Wahrnehmung der Qualität der bisherigen Melanomnachsorge aus der Patientensicht untersucht werden.

Patienten und Methodik: Es wurde eine systematische Stichprobenbefragung von 462 Patienten durchgeführt, die innerhalb der letzten vier Jahre die ambulante Melanomnachsorge in Köln und Münster frequentierten. Die Nachsorge wurde auf der Grundlage der 1994 von der Kommission malignes Melanom publizierten Empfehlungen durchgeführt.

Ergebnisse: Die Nachsorge wurde regelmäßig von den Patienten durchgeführt, vorrangig in Münster in der Klinik (62 %), in Köln alternierend in Kooperation mit niedergelassenen Hautärzten (53 %). Jeweils 70 % der Teilkollektive erhielten regelmäßige radiologische Untersuchungen und bejahten Eigenuntersuchungen. 14 % gaben einen Progreß ihrer Erkrankung an. Nur 15 % der Befragten gaben an, psychosoziale Unterstützung erfahren zu haben.

Schlußfolgerungen: Die Befragung zeigt, daß die im neuen Nachsorgekonzept angedachte interdisziplinäre Nachsorge und Eigenuntersuchungen bereits die Akzeptanz der Patienten gefunden haben. Nach bisherigem Standard fühlten sich 90 % der Patienten durch die Nachsorge gesichert. Die psychosoziale Unterstützung muß stärker für die Patienten konkretisiert werden und neben sozialdienstlichen vermehrt auch psychologische Angebote beinhalten. Bei der Etablierung von Qualitätsstandards können systematische Patientenbefragungen eingesetzt werden, um stärker patientenorientiert zu handeln.
Trichophyton mentagrophytes var. nodulare– Ein seltener Fußpilzerreger auf dem Vormarsch?
Authors: Brasch Jochen
Published: February 2004

Hintergrund: Das Erregerspektrum von Dermatophytosen unterliegt ständigen Änderungen.

Patienten/Methoden: Es werden 2 Trichophyton mentagrophytes var. nodulare‐Stämme mykologisch charakterisiert, die innerhalb der letzten 2 Jahren erstmalig in unserem Labor bei Patienten mit Tinea pedis isoliert wurden.

Ergebnisse: Besondere Merkmale von Trichophyton mentagrophytes var. nodulare sind eine intensive gelb‐orange Thalluspigmentierung, eine starke Pigmentfreisetzung und die Ausbildung von Knotenorganen. Trichophyton mentagrophytes var. nodulare ist als anthropophile Variante von Trichophyton mentagrophytes ein Auslöser von Tinea und Onychomykose.

Schlußfolgerungen: Trichophyton mentagrophytes var. nodulare wurde in Deutschland bisher kaum beobachtet und ist daher wenig bekannt. Eine erhöhte Aufmerksamkeit für diesen Dermatophyten erscheint jetzt jedoch notwendig, um seine möglicherweise zunehmende Verbreitung zu verfolgen.
Role of prophylactic scleral buckling in the management of retained intraocular foreign bodies
Authors: Azad Raj Vardhan , Kumar Neena , Sharma Yog Raj , Vohra Rajpal
Published: February 2004

Purpose: To evaluate the role of prophylactic scleral buckling procedure with pars plana vitrectomy for the removal of retained intraocular foreign bodies (RIOFB) in the prevention of postoperative retinal detachment.

Methods: In a prospective, clinical, controlled study, 28 patients with RIOFB without retinal detachment were randomly divided into two groups of 15 (group I) and 13 (group II) patients. All patients underwent a standard three‐port pars plana vitrectomy with foreign body removal. In addition to this standard procedure, patients assigned to group I had a 360° encircling scleral buckle placed at the time of surgery. Group II patients did not have any scleral buckling. All patients were followed up for an average period of 11.8 months. Both groups were comparable with respect to age, sex, duration of injury, nature of injury, and site, size and type of RIOFB.

Results: The retinal detachment rate was found to be 6.6% in group I and 30.8% in group II (P = 0.24). Prophylactic scleral buckling reduced the risk of retinal detachment by 24% but this was not found to be statistically significant.

Conclusion: Prophylactic scleral buckle placement with pars plana vitreous surgery for RIOFB may reduce the risk of late onset retinal detachment. A larger study would seem warranted.
Goldenhar syndrome: a case from Papua New Guinea
Authors: Tay Thain Siong , Kitz Christa , Booth Frances
Published: February 2004

Goldenhar syndrome is well known for its classical triad of epibulbar dermoids or lipodermoids, auricular appendages and pretragal fistulas. The syndrome was later included under the broader classification of oculoauriculovertebral spectrum to cover a wide range of associated anomalies. Here, a case is presented of Goldenhar syndrome in a child from Papua New Guinea. The patient had large epibulbar lipodermoids requiring surgical debulking primarily for mechanical lagophthalmos and secondarily for cosmesis. Further multidisciplinary effort is required to manage her systemic manifestations of the syndrome.
Clinical Case Notes
Authors: Murthy Gyanam G , Ingole Avinash B , Desai Sangeeta
Published: February 2004

A 65‐year‐old woman presented with malignant melanoma of the right socket following evisceration of her right eye for ocular trauma 8 years previously. Computed tomography demonstrated a solid mass adjacent to the residual eviscerated eyeball without extra­orbital extension. The tumour was removed by total exenteration of the orbit. The clinical and radiological features of this condition, and a review of the literature are presented.
Ponderal index is a poor predictor of in utero growth retardation
Authors: Haggarty P. , Campbell D.M. , Bendomir A. , Gray E.S. , Abramovich D.R.
Published: January 2004

Objective  To evaluate the usefulness of ponderal index (PI) and related indices of weight and length in identifying asymmetric growth, body thinness and organ asymmetry associated with IUGR.

Design  Cross sectional study.

Setting  Aberdeen Maternity Hospital.

Population  The population includes term (≥37 weeks) singleton live births (n= 53,934) between 1986 and 1996, ultrasound measurements in 2522 pregnancies, 712 unselected term pregnancies in 1979/1980 and stillbirths (24–36 weeks) between 1986 and 1995 where the fetus was diagnosed as suffering from acute (n= 73) or chronic (n= 30) anoxic death.

Methods  The strength of association between direct measures of IUGR and various indices of weight and length was determined by linear and multiple stepwise linear regression.

Main outcome measures  Weight, length, PI and skinfold thicknesses (triceps, biceps, flank thighs, back) were measured at birth. Abdominal circumference, biparietal diameter and femur length were measured by ultrasound at ≥37 weeks. Ratio of liver, heart and kidney to brain were measured in stillbirths.

Results  Weight alone was a better predictor of skinfold thickness, abdominal circumference and the ratio of abdominal circumference to biparietal diameter than weight divided by length raised to the power 1, 2, 3 (PI), 4 or 5. The inclusion of gestational age made little difference to the predictive ability of weight for these full term births. Weight, but not PI, was significantly different between the two groups of stillborn fetuses (chronic and acute), which had significantly different (P < 0.001) organ ratios.

Conclusion  Body weight alone was a better predictor of anthropometric ratios, organ asymmetry and measures of thinness at birth thought to be associated with IUGR than the PI. The inclusion of a length term generally reduced the predictive ability with the highest powers resulting in the poorest prediction.
Induction of tumor necrosis factor‐α (TNF‐α) by interleukin‐12 p40 monomer and homodimer in microglia and macrophages
Authors: Jana Malabendu , Dasgupta Subhajit , Saha Ramendra N. , Liu Xiaojuan , Pahan Kalipada
Published: February 2004

The present study was undertaken to explore the role of interleukin‐12 (IL‐12) p40 in the expression of TNF‐α in microglia. Interestingly, we have found that IL‐12 p70, p402 (the p40 homodimer) and p40 (the p40 monomer) dose‐dependently induced the production of TNF‐α and the expression of TNF‐α mRNA in BV‐2 microglial cells. In addition to BV‐2 microglial cells, p70, p402 and p40 also induced the production of TNF‐α in mouse primary microglia and peritoneal macrophages. As the activation of both NF‐κB and CCAAT/enhancer binding protein β (C/EBPβ) is important for the expression of TNF‐α in microglial cells, we investigated the effect of p40 on the activation of NF‐κB as well as C/EBPβ. Activation of NF‐κB as well as C/EBPβ by p40 and inhibition of p40‐induced expression of TNF‐α by Δp65, a dominant‐negative mutant of p65, and ΔC/EBPβ, a dominant‐negative mutant of C/EBPβ, suggests that p40 induces the expression of TNF‐α through the activation of NF‐κB and C/EBPβ. In addition, we show that p40 induced the activation of both extracellular signal‐regulated kinase (ERK) and p38 mitogen‐activated protein kinase (MAPK). Interestingly, PD98059, an inhibitor of ERK, inhibited p40‐induced expression of TNF‐α through the inhibition of C/EBPβ, but not that of NF‐κB, whereas SB203580, an inhibitor of p38 MAPK, inhibited p40‐induced expression of TNF‐α through the inhibition of both NF‐κB and C/EBPβ. This study delineates a novel biological function of p40 in inducing TNF‐α in microglia and macrophages.
Asymmetric contribution of α and β subunits to the activation of αβ heteromeric glycine receptors
Authors: Shan Qiang , Nevin Simon T. , Haddrill Justine L. , Lynch Joseph W.
Published: February 2004

This study investigated the role of β subunits in the activation of αβ heteromeric glycine receptor (GlyR) chloride channels recombinantly expressed in HEK293 cells. The approach involved incorporating mutations into corresponding positions in α and β subunits and comparing their effects on receptor function. Although cysteine‐substitution mutations to residues in the N‐terminal half of the α subunit M2–M3 loop dramatically impaired the gating efficacy, the same mutations exerted little effect when incorporated into corresponding positions of the β subunit. Furthermore, although the α subunit M2–M3 loop cysteines were modified by a cysteine‐specific reagent, the corresponding β subunit cysteines showed no evidence of reactivity. These observations suggest structural or functional differences between α and β subunit M2–M3 loops. In addition, a threonine→leucine mutation at the 9′ position in the β subunit M2 pore‐lining domain dramatically increased the glycine sensitivity. By analogy with the effects of the same mutation in other ligand‐gated ion channels, it was concluded that the mutation affected the GlyR activation mechanism. This supports the idea that the GlyR β subunit is involved in receptor gating. In conclusion, this study demonstrates that β subunits contribute to the activation of the GlyR, but that their involvement in this process is significantly different to that of the α subunit.
Anti‐Proliferative Effect of Mycobacteria, IFN‐γ and TNF‐α on Primary Cultures Derived from Endometrial Stroma: Possible Relevance to Endometriosis?
Authors: Clayton R.D. , Duffy S.R. , Wilkinson N. , Garry R. , Jackson A.M.
Published: January 2004

Problem:  To assess the effects of mycobacteria and inflammatory cytokines on proliferation of endometrial stromal cells. An effect on endometrial stromal cell proliferation in vitro may suggest a similar effect on endometriotic cells in vivo.

Method of study:  Primary cultures of endometrial stromal cells were grown from female volunteers. Proliferation of cells was assessed by cell counting and incorporation of tritiated thymidine after exposure to mycobacteria or inflammatory cytokines.

Results:  When assessed by cell counting, stromal cell growth was reduced following treatment with Connaught Bacillus of Calmette and Guérin (BCG) and Pasteur BCG: Mycobacterium smegmatis demonstrated a cytotoxic effect. Addition of the cytokines interferon (IFN)‐γ or tumour necrosis factor (TNF)‐α at high concentrations led to a reduction in cell growth by 24 hr in two of three cell lines. A reduction in proliferation was also found when assessed by tritiated thymidine incorporation, which was statistically significant for Connaught BCG and M. smegmatis.

Conclusions:  Endometrial stromal cells are susceptible to the anti‐proliferative effects of mycobacteria. The BCG and other mycobacteria are known immunomodulators in other disease conditions. Further work is required to assess whether these in vitro effects might translate into a useful therapy for endometriosis.
Therapy with Dendritic Cells Influences the Spontaneous Resorption Rate in the CBA/J × DBA/2J Mouse Model
Authors: Blois Sandra , Alba Soto Catalina D. , Olmos Sofia , Chuluyan Eduardo , Gentile Teresa , Arck Petra C. , Margni Ricardo A.
Published: January 2004

Problem:  DBA/2J‐mated CBA/J female mice are prone to a high incidence of fetal abortions. This fetal wastage can be dramatically reduced by immunizing the female mice with BALB/c, but not with DBA/2J spleen cells during early gestation. Nevertheless, the underlying mechanisms remain to be elucidated. Recently, dendritic cells (DC) have been described at the feto‐maternal interface in the human uterus. In this work, we studied the effect of adoptive transfer of DC on the maintenance of pregnancy in the CBA/J × DBA/2J model.

Methods:  Bone marrow‐derived DC were generated from virgin female CBA/J mice (6–8 weeks old). CBA/J females were inoculated with DC twice before mating. Four different experimental groups were included: (i) no treatment control, (ii) mice injected with culture medium [granulocyte–macrophage colony‐stimulating factor (GM‐CSF)], (iii) immunized with DC and (iv) immunized with paternal DBA/2J antigens lisate‐pulsed DC, n = 5.

Results:  The control abortion rate was 23.8%, and with GM‐CSF alone was 17.6%. Following inoculation of syngeneic DC abortion rates were reduced to 2.2%, but protection was short‐lived. Abortion rates with DC pulsed with DBA/2J antigens was 5%. Serum of interleukin (IL)‐6 levels were lower in the latter two groups up to the time of abortion. The kinetics of immunoglobulin G asymmetric antibodies synthesis was modified, but there was no correlation between asymmetric antibodies production and the lowering of abortions rates.

Conclusion:  Syngeneic DC prevented abortions and this was linked to a decrease in IL‐6 levels, but not with levels of asymmetric antibodies.
Nerve Growth Factor and its Functional Receptor TrkA are Up‐regulated in Murine Decidual Tissue of Stress‐triggered and Substance P‐mediated Abortion
Authors: Tometten Mareike , Klapp Burghard F. , Joachim Ricarda , Fest Stefan , Zenclussen Ana C. , Peters Eva M. , Hertwig Kai , Arck Petra C.
Published: January 2004

Problem:  Stress, elicited by environmental and social conditions, is known to affect the homeostasis of the nervous, endocrine and immune systems. In pregnancy, perceived stress results in a predomination of inflammatory abortion‐associated Th1 cytokines over immunosuppressive, pregnancy‐protective‐associated Th2 cytokines, putatively via neuropeptide substance P (SP). Nerve growth factor (NGF), an important trophic factor for sympathetic neurons, has been implicated in the responsiveness of immune‐competent cells through its functional receptor, tropomyosin receptor kinase (TrkA). Thus, the aim of the present study was to identify a cross‐talk between distinct neurotrophic and immune mediators in pregnancy maintenance.

Method of Study:  Using immune fluorescence, we evaluated decidual and placental expression of NGF and TrkA on gestation day (gd) 13.5 in the abortion‐prone mouse model CBA/J × DBA/2J in (1) CBA/J female control mice; (2) CBA/J mice exposed to stress on gd 5.5; and (3) CBA/J mice injected with SP on gd 5.5 to mimick stress perception.

Results: Stress and SP injection significantly increased the abortion rate and up‐regulated decidual NGF and TrkA expression compared with the control. Stress, but not SP injection down‐regulated placental NGF, whereas no changes in placental TrkA were observed.

Conclusion:  Our data suggest a functional role for NGF in stress‐triggered, SP‐mediated abortion.
Can ortho–para transitions for water be observed?
Authors: Miani Andrea , Tennyson Jonathan
Published: February 2004

The spectrum of water can be considered as the juxtaposition of the spectra of two molecules, with different total nuclear spin: ortho–H2O, and para–H2O. No transitions have ever been observed between the two different nuclear-spin isotopomers. The interconversion time is unknown and it is widely assumed that interconversion is forbidden without some other intervention. However, weak nuclear spin–rotation interaction occurs and can drive ortho to para transitions. Ab initio calculations show that the hyperfine nuclear spin–rotational coupling constants are about 30 kHz. These constants are used to explore the whole vibration–rotation spectrum with special emphasis on the coupling between nearby levels. Predictions are made for different spectral regions where the strongest transitions between ortho and para levels of water could be experimentally observed.