bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seismicity of the western United States
Authors: Bolt Bruce A. 
Published: May 2013

Abstract
A critical review is given of the present status of the record of earthquakes in the western United States. Special field studies for siting of nuclear reactors and other major structures have brought to light major modifications and revisions of some earlier inferences on the intensity and fault location of historical earthquakes. For example, the hypocenters of the Washington State earthquake of December 14, 1872, and the Lompoc, California, earthquake of November 4, 1927, have recently been redetermined. Presentation and retrieval of both modern and historical seismicity records are still not optimum, with various errors and inconsistencies—some introduced by computer processing.
Increased density of seismographic networks is providing sharper resolution in seismicity mapping. In northern California the pattern of widespread minor seismicity has been defined for the first time; earthquake foci in the Humboldt County region are concentrated in two crustal levels, 0 to 10 km and 18 to 20 km. Use of ocean-bottom seismographs is improving knowledge of the offshore seismicity pattern. Seismotectonic properties of northwestern California, Puget Sound (Washington), and the intermountain seismic belt are now emerging.
Toronto’s subsurface geology
Authors: White Owen L. 
Published: May 2013

Abstract
The subsurface geology in the Toronto area, in which much underground con-struction has taken place in the past 30 years, is, in general, fairly simple, consisting of almost flat-lying Ordovician sediments overlaid by a variable thickness of Quater-nary drift deposits.
The Ordovician rocks provide an interbedded sequence of shales, siltstones and limestones; and the Quaternary deposits, which range in age from Illinoian to Late Wisconsinan, consist of several tills interbedded with water-bearing sands and lacustrine clays and silts.
Construction difficulties arising from the local geological conditions are not great, but unexpected encounters with excess ground water do occur. The presence in the bedrock of high horizontal stresses at shallow depths can cause difficulties, especially to the completed structure, unless the stress condition is recognized, designs are modified, and construction procedures are adapted to the unusual stress environment.
Effects of geology on the development of Edmonton, Alberta, Canada
Authors: Rutter N. W. , Thomson S. 
Published: May 2013

Abstract
The City of Edmonton is underlaid by a thick sequence of Quatenary glacial deposits overlying gently dipping late Cretaceous clastic sediments. The Quaternary stratigraphy consists of Saskatchewan gravels and sands, two continental till deposits (upper and lower till) separated in places by Tofield sand, all overlaid by Glacial Lake Edmonton sediments. Underground activity has centered on tunneling for sanitary and storm sewer systems and, more recently, for part of Edmonton’s Light Rapid Transit system. Nearly all tunneling is in the competent till or bedrock. Other underground activity took place around the turn of the century when coal mining shafts and adits were constructed. Surface subsidence continues today and has to be considered when planning. The greatest hazard in the development of Edmonton is natural landslides that occur along river banks and man-made slopes. Major failures take place mainly in bedrock with small slips in the Lake Edmonton sediments.
Field-based computational techniques for predicting subsidence due to fluid withdrawal
Authors: Helm Donald C. 
Published: May 2013

Abstract
Choice of a predictive technique for land subsidence is based on the availability of appropriate field data. If only the depth and thickness of compressible beds can be estimated, a simple hand calculation is available as a predictive technique and for many purposes is adequate. An example of such a technique uses Schatz, Kasameyer, and Cheney's depth-porosity model. Their depth-porosity model for reservoir compaction is modified in the present paper and is combined with a modified form of Geertsma's nucleus of strain model to form a single predictive technique. The nucleus of strain model accounts for attenuation of vertical movement through the overburden. Based on this combined model, predictions of ultimate vertical subsidence are made at eleven specified locations. At five of these sites in California, Texas, and New Zealand, these predictions are compared to measured subsidence. Agreement between predicted and observed subsidence is good.
If field measurements of water-level fluctuations and the resulting time-dependent compression and expansion of geologic strata are locally available, use of a more refined predictive technique is justified. An example of such a technique uses Tolman and Poland's aquitard-drainage model in conjunction with a field-based method of parameter evaluation (such as Riley's field-based method of estimating specific storage and vertical hydraulic conductivity). Tolman and Poland's conceptual model and Riley's parameter evaluation method have been combined with Helm's one-dimensional finite difference computational scheme to form a powerful time-dependent predictive technique. This technique has been field verified successfully at more than two dozen sites in California and Texas. Use of such a computer code allows prediction of observed time lags in nonlinear compression and expansion of layered sedimentary materials in response to arbitrary sequences of rising and falling water levels.
Organic soil subsidence
Authors: Stephens John C. , Allen Leon H. , Chen Ellen 
Published: May 2013

Abstract
Organic soil subsidence occurs mainly with drainage and development of peat for agriculture. Subsidence occurs either from densification (loss of buoyancy, shrinkage, and compaction) or from actual loss of mass (biological oxidation, burning, hydrolysis and leaching, erosion, and mining). Densification usully occurs soon after drainage is established. Slow, continuous loss of mass is due mainly to biological oxidation. Erosion is minor except in specific sites. Mining losses vary greatly and depend upon direct removal of the materials.
Subsidence rates are determined mainly by type of peat, depth to water table, and temperature. Subsidence losses have been carefully measured in several locations (e.g., the Florida Everglades), and predictions of future subsidence developed in 1950 have proved reliable.
Peat drainage and subsidence have several consequences: loss of plant rooting depth where the substrate is unfavorable (stony, acidic, saline), increased pumping for drainage, instability of roads and other structures, increase in nutrient outflows, colder surface temperature during winter nights, and increase of CO2 flux to the global atmosphere
The water table for organic soils should be held as high as crop and field conditions allow to reduce subsidence.
Computer models offer methods for refining oxidation rate processes and prediction of subsidence losses where adequate calibration data are available. Remote sensing offers a method of assessing organic soil area and drainage changes. These new technologies should improve our assessment, and guide our management, of organic soil resources.
Compound landslides
Authors: Cronin Vincent S. 
Published: May 2013

Abstract
Large host landslides commonly encompass smaller, secondary landslides; hence the term “compound landslide.” Secondary landslides differ significantly from their host landslide in that secondary slides (1) have smaller volume; (2) often have greater surface exposure; (3) are more readily saturated by water infiltration; (4) require a smaller driving force to initiate movement; (5) have greater frequency of movement; and (6) their capacity for movement can be either independent of the host and other adjacent secondary landslides, or induced by adjacent landslides. Multilevel flow systems (perched water tables) commonly form within compound landslides due to the relatively low permeability of slip-surface gouge, which may slow recharge from the overlying secondary landslides to the host landslide. Movement-inducing pore-fluid pressures can often be reached more rapidly in secondary landslides. Controlled sources of water, for example, from irrigation and septic waste-water injection systems, can supplement vastly natural recharge from rainfall, artificially maintaining saturation in near-surface secondary landslides.
The progressive movement of a host landslide can generate a family of precursive failure surfaces in the landslide’s interior that can coalesce to form secondary landslides. Evolution of local topography contributes to the morphology and slip direction of secondary landslides to the extent that stress trajectories within a host landslide are perturbed by changes in the shape of the ground surface; for example, increased slope gradient along a landslide’s toe is a common cause of secondary landsliding. The non-plane strain nature of compound landslides, exemplified by the complex interactions between host and secondary landslides, often precludes the meaningful application of general, plane strain, mechanical models in assessing the hazard potential of a specific compound landslide. Rote stability analyses of compound landslides based upon assumed homogeneous, isotropic, linear-elastic behavior throughout the slide prism fail to consider the intrinsically more unstable (and thus more hazardous) secondary landslides.
Geologists involved in landslide exploration must be aware of the characteristics of compound landsliding; those involved in mitigation must consider the hydrologic and dynamic implications of secondary landsliding in order to conduct the requisite field investigations and make appropriate design recommendations, which must be individu-ally suited to each compound landslide.
Differentiation between normal residence performance and landslide-related distress in the evaluation and treatment of slope instability in southern California
Authors: Robertson Hugh S. , Hollingsworth Robert A. 
Published: May 2013

Abstract
The evaluation and repair of hillside properties damaged by slope instability presents a challenging problem for the geotechnical professional. An increasing number of residential distress evaluations are being requested by homeowner insurance companies to resolve earth-movement claims. Early recognition of instability is essential to the successful mitigation of the hazard. Thorough observation of structural distress, experience, and an understanding of construction are needed to differentiate typical distress from subtle distress associated with the initiation of slope instability. Other soil-related processes cause distress similar in appearance to major slope movement, and complicate recognition of an impending hazard.
Property-line limitations and reluctant neighbors hamper site and neighborhood reconnaissance. High costs and physical constraints limit the subsurface exploration, which is critical to determining the mechanics of movement. Conventional exploration techniques are aided by modern instrumentation and detailed site monitoring to define probable causes. Selection of reasonable repair methods and stabilization devices de-pends on the limits of the failing mass and whether instability is associated with failure along a predetermined defect or through an inherently weak mass. Continued monitor-ing from recognition through stabilization helps verify the causes of instability, the design scheme, and the success of the treatment. Repairs are effective if the factor of safety is sufficiently increased by common and economical construction techniques in a timely manner.
Attitudes of general practitioners to screening for cystic fibrosis
Authors: Mennie M , Campbell H , Liston W A , Brock D J H 
Published: May 2013

Objective To ascertain the views of general practitioners (GPs) about screening for cystic fibrosis. To find out whether and under what conditions they might play a part in the delivery of such programmes. Setting All GP practices within the Lothian Health Board area. Methods A self administered questionnaire was sent to each of the 532 GPs in the area. Results 334 (63%) GPs participated in the study. Only 23% of these claimed to have no professional or personal experience of the disorder. 77% of GPs were aware of the existence of a programme of antenatal screening for cystic fibrosis (CF), which had been running in Edinburgh for the past six years, with only 2% unfavourably disposed to it. However, when asked to rank CF screening against antenatal screening for spina bifida and Down's syndrome, or cervical and breast screening, 55% gave it the lowest priority. There was fairly equal support for the screening site being an antenatal clinic, a genetic centre, a family planning clinic, or a GP surgery, but little enthusiasm for programmes in schools or the workplace. Surprisingly, only 13% of GPs thought that screening should be offered to those with a negative family history of the disorder. Although the idea of involvement in screening was favoured, GPs claimed that any aspect of delivery that they undertook would need to be supported. There were no significant differences between the responses of fundholding GPs and non-fundholders. Conclusions The low ranking by GPs of CF screening against other programmes, together with the need for support if they were to be involved, suggests that it is currently impractical to move the programme from its existing site in antenatal clinics.
Breast cancer in East Anglia: the impact of the breast screening programme on stage at diagnosis
Authors: McCann J , Stockton D , Day N 
Published: May 2013

Objectives To assess the impact of the National Health Service breast screening programme on overall and stage-specific incidence of breast cancer in East Anglia; also, to predict the magnitude of the screening induced reduction in breast cancer mortality. Setting Women resident in East Anglia aged 50–69, diagnosed between 1976 and 1995. Methods Comparison of numbers and incidence of breast cancer by age, stage, and mode of detection; investigation of relative contributions of advanced (stages II, III, and IV) cancers to total incidence by detection mode; estimation of the reduction in advanced cancer incidence. Results There has been a large increase in early stage incidence in the age group 50–64 targeted by the screening programme. By 1995, the estimated decrease in advanced cancer incidence was between 7 and 19%. In 1995, of all breast cancers arising in the age group 50–69 years, 33% were screen detected, 27% were interval cancers, 15% were in non-attenders, 9% were in lapsed attenders, 7% occurred before invitation, and 4% arose in women outside the birth year range for invitation. Of the advanced cancers diagnosed in 1995, 31% were interval cancers, 20% were screen detected, 19% were in non-attenders, 12% were in lapsed attenders, 8% occurred before invitation, and 4% presented in women outside the birth year range for invitation. Conclusions Screening has brought about a large increase in detection of early stage cancers. This increase has not yet been fully matched by a corresponding deficit in advanced cancers, possibly because the full effect of screening has not yet been achieved. Reducing the proportion of interval cancers is necessary to increase the effect of screening on mortality.
The importance of age in screening for cancer
Authors: Law M.R. , Morris J.K. , Wald N.J. 
Published: May 2013

Objective To derive a rational method of selecting the age range over which screening tests for cancer should be offered (that is, over which they would be most effective in saving life). Main outcome measureThe number of person-years of life that are lost through deaths occurring at each year of age from each of six cancers. Results For each cancer the number of years of life lost to age 80, plotted against age at death, showed a rise followed by a fall. The peak indicates the age at which deaths from the cancer result in most years of life lost. Special screening tests, such as mammography for breast cancer, will be most effective in saving life shortly before that age. The peak (as a five year age span) occurs at age 55–59 for breast cancer (189 years of life lost per 10 000 women per year), 70–74 for prostate cancer (114), 65–69 for colorectal cancer (96), 55–59 for ovarian cancer (61), 50–54 for cervical cancer (47), and 45–50 for melanoma (8). The precise interval by which special screening tests should precede the peak age is not critical; five years would be appropriate. Given current evidence on the efficacy of cancer screening, if it were stipulated that screening could only be performed when at least 50 years of life were to be gained per 10 000 persons screened, only mammography for breast cancer would be conducted, between the ages of 50 and 59. If the stipulation was 25 or more years of life gained mammography would be offered to women aged 40–69 and cervical smears to women aged 35–59. With only 10 or more years of life gained (unlikely to be worthwhile) mammography would be extended to women aged 30–74, cervical smears to 25–69, and faecal occult blood testing for colorectal cancer offered to those aged 45–74. Extending cervical cancer screening to age 69 would save more years of life than the present policy of screening women aged 20–29. Extending breast cancer screening to the age of 74 would be more effective than cervical screening at any age. Conclusions Determining the number of years of life lost through deaths from a particular cancer at each age is useful in public health screening policy, both in selecting the age range over which special screening tests of proven efficacy should be offered and in quantitatively comparing the value of screening for different cancers.
Screening for malignant melanoma using instant photography
Authors: Edmondson P.C. , Curley R.K. , Marsden R.A. , Robinson D. , Allaway S.L. , Willson C.D. 
Published: May 2013

Objective To assess the use of instant photography, in addition to clinical grading, as a method of screening for malignant melanoma during routine health examinations. Setting A health screening clinic with an average throughput of about 12 000 patients a year. Methods Suspicious pigmented skin lesions were judged clinically using the revised seven point checklist scoring system. They were then photographed with a Polaroid camera and the prints were graded independently by two consultant dermatologists with a special interest in malignant melanoma. A copy of the print was also given to the patient to keep for observation of any change in the lesion. Results Over a 45 month period 39 922 patients of both sexes were screened and 1052 skin lesions were clinically assessed and photographed. Fourteen malignant melanomas were diagnosed—all, except one, were thin lesions with a good prognosis. Conclusions The clinical opinions of non-dermatologists using the revised seven point checklist proved disappointing in screening because of the large number of benign lesions that were given high scores. Photography, on the other hand, detected 11 melanomas and succeeded in separating the majority of banal lesions from potentially malignant ones, thus greatly reducing the need for specialist referral. Nevertheless, three melanomas were missed on purely photographic grading, which emphasises the danger of placing too much reliance solely on a two dimensional image. Finally, the possession of a personal copy of the photograph by the patient proved popular and led to a diagnosis of melanoma in two instances. This procedure merits further study.
What is the cost utility of screening for hepatitis C virus (HCV) in intravenous drug users?
Authors: Leal P. , Stein K. , Rosenberg W. 
Published: May 2013

Objectives To model the likely cost utility of the prevalence round of a screening programme for hepatitis C (HCV) in intravenous drug users (IVDUs) in contact with services in the South and West health region of the UK. Methods Information on the prevalence of HCV, performance of diagnostic tests, and effectiveness of interferon α (IFNα) for treatment of chronic hepatitis were brought together with estimates of the costs of service provision. A simple spreadsheet model was used to estimate cost utility (cost/quality adjusted life year (QALY)). Assumptions (including use of ribavirin plus IFNα combination therapy) were tested by a one way sensitivity analysis. Results About 5600 IVDUs live in the region. A combination of enzyme linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) testing has high sensitivity and specificity for detecting HCV. There is excellent evidence that IFNα is effective in producing sustained normalisation of liver function and, by inference, eradicating HCV. Evidence for long term benefits comes from modelling studies based on progression of HBV or non-A, non-B hepatitis and is considerably less robust. The cost of the prevalence round of screening in IVDUs would be about £700 000 and is likely to identify about 1400 people, of whom about 270 would be eligible for treatment and 20 would respond to IFNα. This gives a cost/QALY of £9300 for the screening programme. However, much uncertainty around the estimates used to inform the cost utility calculation limits confidence in the value of screening IVDUs for HCV. Sensitivity analysis shows a range of possible cost utility from £3333 to £81 438. Estimates are particularly sensitive to adherence to liver biopsy and treatment and to discounting of benefits. Conclusions Although potentially cost effective, many important uncertainties surround the assumptions used to estimate the long term effectiveness of screening and treatment. There is insufficient evidence to inform policy development and further research is required in this rapidly changing field.
Monitoring interval cancers in an Australian mammographic screening programme
Authors: Kavanagh A.M. , Mitchell H. , Farrugia H. , Giles G.G. 
Published: May 2013

Objective To report the interval cancer rate for BreastScreen Victoria. Design Electronic linkage of Breast Screen Victoria records with those of the Victorian Cancer Registry. Interval cancers were expressed as a proportion of the underlying incidence (proportional incidence), and the sensitivity as the number of screen detected invasive breast cancers divided by the total number of invasive breast cancers diagnosed in the screening interval. Setting Victoria, Australia where biennial screening is provided to women aged 40 and older. Subjects Victorian women aged 40–79 who attended first round screening in 1994 (103 023 women) and 1995 (107 057 women). Results The sensitivity of screening mammography for the two year interval increased with age (p for trend < 0.001) and was 49.4% in women aged 40–49, 68.6% in 50–59 year old women, 80.7% in 60–69 year old women, and 85.2% in women aged 70–79. The proportional incidence in the first year after screening was 59% in 40–49 year old women and 27% in women aged 50–69. In the second year the proportional incidence was 93% in 40–49 year old women and 54% in women aged 50–69. Conclusions Interval cancers comprise such a large proportion of the expected number of cancers in 40–49 year old women that the benefit of screening is likely to be low. For women aged 50–69, the proportional incidence found in this study was similar to those found in the UK programmes.