Failure of a Pipeline in an 800-year Old Debris Fill

In June of 1994 a 20-m section of 1.4-m diameter, restrained-joint, ductile iron pipe failed during construction of a new section of water pipeline for the city of Cairo in the Arab Republic of Egypt. The failure occurred in an area where the pipe was supported on piles, and compacted silica sand was used as side support for the pipe. Soil above the crown of the failed section of pipe was 6 m or more in thickness. Results of a detailed review of the failure revealed that a number of unique and related factors apparently caused the failure. The most significant of these causes was the native soil surrounding the pipeline, which was formed from an accumulation of 800 years of building and construction debris. At the location of the failure the debris was in excess of 15-m thick. When subjected to water at this location, this debris underwent significant settlement, which eventually led to loss in side support for the pipeline. To repair the pipeline and to avoid future similar failures, a utilidor was used to protect the pipeline in areas where overburden thickness was greater than 4.5 m, and a pipe encasement was used where the overburden thickness was less

The Sensitivity of Auditory-Motor Representations to Subtle Changes in Auditory Feedback While Singing

Singing requires accurate control of the fundamental frequency (F0) of the voice. This study examined trained singers’ and untrained singers’ (nonsingers’) sensitivity to subtle manipulations in auditory feedback and the subsequent effect on the mapping between F0 feedback and vocal control. Participants produced the consonant-vowel /ta/ while receiving auditory feedback that was shifted up and down in frequency. Results showed that singers and nonsingers compensated to a similar degree when presented with frequency-altered feedback (FAF); however, singers’ F0 values were consistently closer to the intended pitch target. Moreover, singers initiated their compensatory responses when auditory feedback was shifted up or down 6 cents or more, compared to nonsingers who began compensating when feedback was shifted up 26 cents and down 22 cents. Additionally, examination of the first 50 ms of vocalization indicated that participants commenced subsequent vocal utterances, during FAF, near the F0 value on previous shift trials. Interestingly, nonsingers commenced F0 productions below the pitch target and increased their F0 until they matched the note. Thus, singers and nonsingers rely on an internal model to regulate voice F0, but singers’ models appear to be more sensitive in response to subtle discrepancies in auditory feedback

Trust \u3ci\u3eThe Key to Leading When Lives Are on the Line\u3c/i\u3e

The Hostage Rescue Team (HRT) of the Federal Bureau of Investigation was called in to assist the bureau\u27s Special Weapons and Tactics (SWAT) team in Memphis to apprehend a married couple wanted on drug trafficking charges. The fugitive couple and an adult son, all with criminal records, were believed to be living in trailers in a mountain valley where outsiders would be easily noticed. The fugitives were known to stockpile weapons and had vowed never to be taken alive by law enforcement. Thus the FBI considered them to be armed and extremely dangerous. Two HRT snipers along with two SWAT snipers were given the mission of positively identifying the fugitives and providing security and containment for the assault force. The snipers would have to travel several kilometers through wooded, mountainous terrain using night vision goggles (NVGs). The SWAT snipers did not have nighttime, overland movement capability, which is why HRT was brought in

Fueling of a marine-terrestrial ecosystem by a major seabird colony

Seabirds redistribute nutrients between different ecosystem compartments and over vast geographical areas. This nutrient transfer may impact both local ecosystems on seabird breeding islands and regional biogeochemical cycling, but these processes are seldom considered in local conservation plans or biogeochemical models. The island of Stora Karlso in the Baltic Sea hosts the largest concentration of piscivorous seabirds in the region, and also hosts a large colony of insectivorous House martins Delichon urbicum adjacent to the breeding seabirds. We show that a previously reported unusually high insectivore abundance was explained by large amounts of chironomids-highly enriched in delta N-15-that feed on seabird residues as larvae along rocky shores to eventually emerge as flying adults. Benthic ammonium and phosphate fluxes were up to 163% and 153% higher close to the colony (1,300 m distance) than further away (2,700 m) and the estimated nutrient release from the seabirds at were in the same order of magnitude as the loads from the largest waste-water treatment plants in the region. The trophic cascade impacting insectivorous passerines and the substantial redistribution of nutrients suggest that seabird nutrient transfer should be increasingly considered in local conservation plans and regional nutrient cycling models.Peer reviewe

Long-term survivors of childhood cancer report quality of life and health status in parity with a comparison group

Background: There is a need for more knowledge about how survivors of childhood cancer perceive their lives and what influence current health status has on their quality of life. The purpose was to describe this among a group of long-term survivors and among a comparison group. Procedure: Telephone interviews were performed with a cohort of 246 long-term survivors and 296 randomly selected from the general population using the Schedule for the Evaluation of Individual Quality of Life- Direct Weighting (SEIQoL-DW). The participants nominated the areas they considered to be most important in life and rated the current status of each area on a seven-point category scale. An overall individual index score was calculated as a measure of quality of life. Self-reported health status was assessed using the Short Form Health Survey (SF-36). Results: Long-term survivors rated their overall quality of life and self-reported health status almost in parity with the comparison group. In both groups, family life, relations to other people, work and career, interests and leisure activities were the areas most frequently reported to influence quality of life. The survivors only differed from the comparison group on one of eight SF-36 scales reflecting problems with daily activities owing to physical health. Conclusions: Health status was not shown to have a major impact on overall quality of life, indicating that health and quality of life should be evaluated distinctively as different constructs. This should be taken in consideration in clinical care of children with childhood cancer and long-term survivors

Casimir Energy For a Massive Dirac Field in One Spatial Dimension: A Direct Approach

In this paper we calculate the Casimir energy for a massive fermionic field confined between two points in one spatial dimension, with the MIT Bag Model boundary condition. We compute the Casimir energy directly by summing over the allowed modes. The method that we use is based on the Boyer's method, and there will be no need to resort to any analytic continuation techniques. We explicitly show the graph of the Casimir energy as a function of the distance between the points and the mass of the fermionic field. We also present a rigorous derivation of the MIT Bag Model boundary condition.Comment: 8 Pages, 4 Figure

Seven naturally variant loci serve as genetic modifiers of Lamc2jeb induced non-Herlitz junctional Epidermolysis Bullosa in mice.

Epidermolysis Bullosa (EB) is a group of rare genetic disorders that compromise the structural integrity of the skin such that blisters and subsequent erosions occur after minor trauma. While primary genetic risk of all subforms of EB adhere to Mendelian patterns of inheritance, their clinical presentations and severities can vary greatly, implying genetic modifiers. The Lamc2jeb mouse model of non-Herlitz junctional EB (JEB-nH) demonstrated that genetic modifiers can contribute substantially to the phenotypic variability of JEB and likely other forms of EB. The innocuous changes in an \u27EB related gene\u27, Col17a1, have shown it to be a dominant modifier of Lamc2jeb. This work identifies six additional Quantitative Trait Loci (QTL) that modify disease in Lamc2jeb/jeb mice. Three QTL include other known \u27EB related genes\u27, with the strongest modifier effect mapping to a region including the epidermal hemi-desmosomal structural gene dystonin (Dst-e/Bpag1-e). Three other QTL map to intervals devoid of known EB-associated genes. Of these, one contains the nuclear receptor coactivator Ppargc1a as its primary candidate and the others contain related genes Pparg and Igf1, suggesting modifier pathways. These results, demonstrating the potent disease modifying effects of normally innocuous genetic variants, greatly expand the landscape of genetic modifiers of EB and therapeutic approaches that may be applied

Severity of back pain may influence choice and order of practitioner consultations across conventional, allied and complementary health care: A cross-sectional study of 1851 mid-age Australian women

© 2016 The Author(s). Background: Back pain is a common, disabling and costly disorder for which patients often consult with a wide range of health practitioners. Unfortunately, no research to date has directly examined the association between the severity of back pain and back pain sufferers' choice of whom and in what order to consult different health practitioners. Methods: This is a sub-study of the large nationally representative Australian Longitudinal Study on Women's Health (ALSWH). The mid-age cohort women (born 1946-51, n = 13,715) of the ALSWH were recruited from the Australian national Medicare database in 1996. These women have been surveyed six time, with survey 6 being conducted in 2010 (n = 10,011). Mid-age women (n = 1851) who in 2010 had sought help from a health care practitioner for their back pain were mailed a self-report questionnaire targeting their previous 12 months of health services utilisation, health status and their levels of back pain intensity. Results: A total of 1620 women were deemed eligible and 1310 (80.9 %) returned completed questionnaires. Mid-age women with back pain visited various conventional, allied health and CAM practitioners for care: 75.6 % consulted a CAM practitioner; 58.4 % consulted a medical doctor; and 54.2 % consulted an allied health practitioner. Women with the most severe back pain sought conventional care from a general practitioner, and those who consulted a general practitioner first had more severe back pain than those who consulted another practitioner first. Following the general practitioner visit, the women with more severe back pain were more likely to be referred to a conventional specialist, and those with less severe back pain were more likely to be referred to a physiotherapist. Conclusions: Our findings suggest that women with more severe back pain are likely to visit a conventional practitioner first, whereas women with less severe back pain are likely to explore a range of treatment options including CAM practitioners. The improvement of back pain over time following the various possible sequencing of consultations with different types of health practitioners is a topic with implications for ensuring safe and effective back pain care and worthy of further detailed investigation