bluuebunny/crossref_metadata_2025 huggingface dataset:
Internal Tides and Mixing in a Submarine Canyon with Time-Varying Stratification
Authors: Zhao Zhongxiang , Alford Matthew H. , Lien Ren-Chieh , Gregg Michael C. , Carter Glenn S.
Published: July 2012

The time variability of the energetics and turbulent dissipation of internal tides in the upper Monterey Submarine Canyon (MSC) is examined with three moored profilers and five ADCP moorings spanning February–April 2009. Highly resolved time series of velocity, energy, and energy flux are all dominated by the semidiurnal internal tide and show pronounced spring-neap cycles. However, the onset of springtime upwelling winds significantly alters the stratification during the record, causing the thermocline depth to shoal from about 100 to 40 m. The time-variable stratification must be accounted for because it significantly affects the energy, energy flux, the vertical modal structures, and the energy distribution among the modes. The internal tide changes from a partly horizontally standing wave to a more freely propagating wave when the thermocline shoals, suggesting more reflection from up canyon early in the observational record. Turbulence, computed from Thorpe scales, is greatest in the bottom 50–150 m and shows a spring-neap cycle. Depth-integrated dissipation is 3 times greater toward the end of the record, reaching 60 mW m−2 during the last spring tide. Dissipation near a submarine ridge is strongly tidally modulated, reaching 10−5 W kg−1 (10–15-m overturns) during spring tide and appears to be due to breaking lee waves. However, the phasing of the breaking is also affected by the changing stratification, occurring when isopycnals are deflected downward early in the record and upward toward the end.
Sensitivities of a Squall Line over Central Europe in a Convective-Scale Ensemble
Authors: Hanley K. E. , Kirshbaum D. J. , Roberts N. M. , Leoncini G.
Published: July 2012

Convective-scale ensemble simulations with perturbed initial and lateral boundary conditions are performed to investigate the mechanisms and sensitivities of a central European convection event from the Convective and Orographically Induced Precipitation Study (COPS). In this event, a “primary” squall line developed ahead of a decaying mesoscale convective system (MCS) upstream of the Vosges Mountains (France), weakened over the Rhine valley, then regenerated as a “secondary” squall line over the Black Forest Mountains (Germany). All ensemble members captured the squall-line evolution, but most suffered from a delay in the onset of convection and positional errors of 50–150 km over the COPS region. These errors in the secondary initiation were linked to errors in the primary initiation. Detailed analysis revealed a similar primary initiation mechanism in all members: in the ascending branch of a midlevel frontal circulation ahead of the MCS, convection initiated within a mesoscale moisture anomaly embedded within the prefrontal flow. The differences in the skill of the ensemble members were related to subtle differences in their initial upper-level representation of potential vorticity (PV). Members that verified well possessed a stronger PV gradient at the leading edge of an upper-level trough. This led to more rapid cyclogenesis over northern France and the United Kingdom and faster development and propagation of the midlevel front and the prefrontal moisture anomaly. As a consequence, the squall lines in these members developed earlier and closer to the COPS region. This case study provides an example of the subtle mechanisms by which errors on the larger scales may transfer to the convective scale and lead to errors in quantitative precipitation forecasts.
Racial-Ethnic Biases, Time Pressure, and Medical Decisions
Authors: Stepanikova Irena
Published: July 2012

This study examined two types of potential sources of racial-ethnic disparities in medical care: implicit biases and time pressure. Eighty-one family physicians and general internists responded to a case vignette describing a patient with chest pain. Time pressure was manipulated experimentally. Under high time pressure, but not under low time pressure, implicit biases regarding blacks and Hispanics led to a less serious diagnosis. In addition, implicit biases regarding blacks led to a lower likelihood of a referral to specialist when physicians were under high time pressure. The results suggest that when physicians face stress, their implicit biases may shape medical decisions in ways that disadvantage minority patients.
Gender and Higher Education in the Time of Reforms
Authors: John Mary E.
Published: July 2012

The current moment of higher education reforms in India has yet to receive sustained attention from scholars and activists. Historically speaking, women’s education occupied a central place from the nineteenth century to the first decades of India’s independence, but, curiously, lost prominence with the onset of the women’s movement and the introduction of women’s studies in the academy in the 1980s and since then. Although the participation of women in higher education shows steady improvement and a narrowing of the gender gap, the article examines national-level data to reveal the complex and elusive forms being currently assumed by gender discrimination. This includes recognising that disparities among women from different social groups are greater than those among men of the same groups. Secondly, many of the contexts where gender gaps have closed are also characterised by adverse child sex ratios due to practices of sex selection. Taken together, the current era of expansion in higher education demands analysis from a gendered perspective.
Holding on to What You Have Got
Authors: Claxton-Oldfield Stephen , Jones Richard
Published: July 2012

In all, 119 hospice palliative care volunteers from 3 community-based hospice programs completed the Volunteer Retention Questionnaire (VRQ), a 33-item survey designed for this study. The VRQ asks volunteers to rate the importance of each item to their decision to continue volunteering. The items that received the highest mean importance ratings included enjoying the work they do, feeling adequately prepared/trained to perform their role, and learning from their patients’ experiences/listening to their patients’ life stories. Being recognized (eg, pins for years of service or being profiled in the hospice newsletter), receiving phone calls/cards from their volunteer coordinator on special occasions, and being reimbursed for out-of-pocket expenses were among the items that received the lowest mean importance ratings. Suggestions for improving volunteer retention are provided.
Validation of Noninvasive Body Sensor Network Technology in the Detection of Agitation in Dementia
Authors: Bankole Azziza , Anderson Martha , Smith-Jackson Tonya , Knight Aubrey , Oh Kyunghui , Brantley Jeff , Barth Adam , Lach John
Published: July 2012

Objective:

Agitated behaviors are one of the most frequent reasons that patients with dementia are placed in long-term care settings. This study aims to validate the ability of a custom Body Sensor Network (BSN) to capture the presence of agitation against currently accepted subjective measures, the Cohen-Mansfield Agitation Inventory (CMAI) and the Aggressive Behavior Scale (ABS) and to discriminate between agitation and cognitive decline.

Methods:

Six patients identified as being at high risk for agitated behaviors were enrolled in this study. The devices were applied at three sites for three hours while behaviors were annotated simultaneously and subsequently repeated twice for each enrolled subject.

Results:

We found that the BSN was a valid measure of agitation based on construct validity testing and secondary validation using non-parametric ANOVAs.

Discussion:

The BSN shows promise from these pilot results. Further testing with a larger sample is needed to replicate these results.
APOE Genotype in the Diagnosis of Alzheimer’s Disease in Patients With Cognitive Impairment
Authors: Sun Xiaoyan , Nicholas Joyce , Walker Aljoeson , Wagner Mark T. , Bachman David
Published: July 2012

Background:

Although an association between the apolipoprotein E ( APOE) ∊4 allele and increased risk of Alzheimer’s disease (AD) is established, the utility of APOE genotyping in the clinical diagnosis of AD is still under investigation.

Methods:

Medical records of 89 patients with cognitive impairment and APOE genotype data underwent a retrospective review.

Results:

Comparison of age, age at onset, education, Mini-Mental State Examination, months of follow-up, and family history of dementia did not reveal statistical difference among the patients with different APOE genotypes. The APOE ∊4 carriers had a higher percentage of AD diagnoses after a median 16 months follow-up than non- APOE ∊4 carriers. The APOE ∊4 designation had a high sensitivity and high positive predictive value for the diagnosis of AD but a low negative predictive value and specificity.

Conclusions:

The APOE genotyping may be helpful in diagnosing AD especially in patients presenting with atypical features or early age of onset of dementia.
Dr Tulp attends the soft machine
Authors: McClimens Alex , Lewis Robin , Brewster Jacqui
Published: July 2012

Simulation as a way to teach clinical skills attracts much critical attention. Its benefits, however, might be significantly reduced when the simulation model used relies exclusively on patient simulators. This is particularly true if the intended patient population for students taught is characterized by intellectual disability. Learning to care for people with intellectual disability might be better supplemented when the simulation model used incorporates input from ‘real’ people. If these people themselves have intellectual disabilities then the verisimilitude of the simulation will be higher and the outcomes for learners and potential patients will also be improved.
ICAM-1–activated Src and eNOS signaling increase endothelial cell surface PECAM-1 adhesivity and neutrophil transmigration
Authors: Liu Guoquan , Place Aaron T. , Chen Zhenlong , Brovkovych Viktor M. , Vogel Stephen M. , Muller William A. , Skidgel Randal A. , Malik Asrar B. , Minshall Richard D.
Published: July 2012

Polymorphonuclear neutrophil (PMN) extravasation requires selectin-mediated tethering, intercellular adhesion molecule-1 (ICAM-1)–dependent firm adhesion, and platelet/endothelial cell adhesion molecule 1 (PECAM-1)–mediated transendothelial migration. An important unanswered question is whether ICAM-1–activated signaling contributes to PMN transmigration mediated by PECAM-1. We tested this concept and the roles of endothelial nitric oxide synthase (eNOS) and Src activated by PMN ligation of ICAM-1 in mediating PECAM-1–dependent PMN transmigration. We observed that lung PMN infiltration in vivo induced in carrageenan-injected WT mice was significantly reduced in ICAM-1−/− and eNOS−/− mice. Crosslinking WT mouse ICAM-1 expressed in human endothelial cells (ECs), but not the phospho-defective Tyr518Phe ICAM-1 mutant, induced SHP-2–dependent Src Tyr530 dephosphorylation that resulted in Src activation. ICAM-1 activation also stimulated phosphorylation of Akt (p-Ser473) and eNOS (p-Ser1177), thereby increasing NO production. PMN migration across EC monolayers was abolished in cells expressing the Tyr518Phe ICAM-1 mutant or by pretreatment with either the Src inhibitor PP2 or eNOS inhibitor L-NAME. Importantly, phospho–ICAM-1 induction of Src signaling induced PECAM-1 Tyr686 phosphorylation and increased EC surface anti–PECAM-1 mAb-binding activity. These results collectively show that ICAM-1–activated Src and eNOS signaling sequentially induce PECAM-1–mediated PMN transendothelial migration. Both Src and eNOS inhibition may be important therapeutic targets to prevent or limit vascular inflammation.
Syncytial giant cell hepatitis associated with chronic lymphocytic leukemia: a case report
Authors: Gupta Eva , Yacoub Michael , Higgins Martha , Al-Katib Ayad M
Published: July 2012

Background

Syncytial giant cell hepatitis (GCH) is an uncommon and an underreported disease entity. In two previously reported cases of GCH in patients with Chronic Lymphocytic Leukemia (CLL) liver failure ensued. Autoimmune and infective causes have been implicated but its etiology remains unclear.

Case Presentation

A 60-year-old female with CLL presented with acute hepatitis with negative viral and auto-immune serologies and without any prior toxic exposure. Liver biopsy showed typical histological features of GCH. The patient was successfully treated with corticosteroids and intravenous immunoglobulin (IVIG). Her liver enzymes returned to baseline and have remained normal as of the last follow up almost 4 years later.

Conclusions

Association of GCH with CLL may be under recognized. Clinical suspicion of GCH in CLL patients with serology-negative hepatitis, early liver biopsy and therapeutic intervention may influence outcome. This is the first case report of successful treatment of GCH in CLL patients. Moreover, our case also demonstrates the ability to resume effective CLL therapy post-GCH diagnosis without detriment to the liver.
Triangle pore arrays fabricated on Si (111) substrate by sphere lithography combined with metal-assisted chemical etching and anisotropic chemical etching
Authors: Asoh Hidetaka , Fujihara Kosuke , Ono Sachiko
Published: July 2012

The morphological change of silicon macropore arrays formed by metal-assisted chemical etching using shape-controlled Au thin film arrays was investigated during anisotropic chemical etching in tetramethylammonium hydroxide (TMAH) aqueous solution. After the deposition of Au as the etching catalyst on (111) silicon through a honeycomb mask prepared by sphere lithography, the specimens were etched in a mixed solution of HF and H2O2 at room temperature, resulting in the formation of ordered macropores in silicon along the [111] direction, which is not achievable by conventional chemical etching without a catalyst. In the anisotropic etching in TMAH, the macropores changed from being circular to being hexagonal and finally to being triangular, owing to the difference in etching rate between the crystal planes.
A systematic review on status of lead pollution and toxicity in Iran; Guidance for preventive measures
Authors: Karrari Parissa , Mehrpour Omid , Abdollahi Mohammad
Published: July 2012

Lead is an old environmental metal which is presented everywhere and lead poisoning is an important health issue in many countries in the world including Iran. It is known as a silent environmental disease which can have life-long adverse health effects. In children, the most vulnerable population, mental development of children health effects is of the greatest influence. Low level lead exposure can significantly induce motor dysfunctions and cognitive impairment in children. The sources of lead exposure vary among countries. Occupational lead exposure is an important health issue in Iran and mine workers, employees of paint factories, workers of copying centers, drivers, and tile making factories are in higher risk of lead toxicity. Moreover lead processing industry has always been a major of concern which affects surface water, drinking waters, and ground waters, even water of Caspian Sea, Persian Gulf and rivers due to increasing the number of industries in vicinity of rivers that release their waste discharges into river or sea. In addition, lead contamination of soil and air especially in vicinity of polluted and industrialized cities is another health problem in Iran. Even foods such as rice and fishes, raw milk, and vegetables which are the most common food of Iranian population are polluted to lead in some area of Iran. Adding lead to the opium is a recently health hazard in Iran that has been observed among opium addicts. There are few studies evaluated current status of lead exposure and toxicity in the Iranian children and pregnant women which should be taken into account of authorities. We recommend to identify sources, eliminate or control sources, and monitor environmental exposures and hazards to prevent lead poisoning.
The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review
Authors: Herman Katherine , Barton Christian , Malliaras Peter , Morrissey Dylan
Published: July 2012

Background

Lower limb injuries in sport are increasingly prevalent and responsible for large economic as well as personal burdens. In this review we seek to determine which easily implemented functional neuromuscular warm-up strategies are effective in preventing lower limb injuries during sports participation and in which sporting groups they are effective.

Methods

Seven electronic databases were searched from inception to January 2012 for studies investigating neuromuscular warm-up strategies and injury prevention. The quality of each included study was evaluated using a modified version of the van Tulder scale. Data were extracted from each study and used to calculate the risk of injury following application of each evaluated strategy.

Results

Nine studies were identified including six randomized controlled trials (RCT) and three controlled clinical trials (CCT). Heterogeneity in study design and warm-up strategies prevented pooling of results. Two studies investigated male and female participants, while the remaining seven investigated women only. Risk Ratio (RR) statistics indicated 'The 11+' prevention strategy significantly reduces overall (RR 0.67, confidence interval (CI) 0.54 to 0.84) and overuse (RR 0.45, CI 0.28 to 0.71) lower limb injuries as well as knee (RR 0.48, CI 0.32 to 0.72) injuries among young amateur female footballers. The 'Knee Injury Prevention Program' (KIPP) significantly reduced the risk of noncontact lower limb (RR 0.5, CI 0.33 to 0.76) and overuse (RR 0.44, CI 0.22 to 0.86) injuries in young amateur female football and basketball players. The 'Prevent Injury and Enhance Performance' (PEP) strategy reduces the incidence of anterior cruciate ligament (ACL) injuries (RR 0.18, CI 0.08 to 0.42). The 'HarmoKnee' programme reduces the risk of knee injuries (RR 0.22, CI 0.06 to 0.76) in teenage female footballers. The 'Anterior Knee Pain Prevention Training Programme' (AKP PTP) significantly reduces the incidence of anterior knee pain (RR 0.27, CI 0.14 to 0.54) in military recruits.

Conclusions

Effective implementation of practical neuromuscular warm-up strategies can reduce lower extremity injury incidence in young, amateur, female athletes and male and female military recruits. This is typically a warm-up strategy that includes stretching, strengthening, balance exercises, sports-specific agility drills and landing techniques applied consistently for longer than three consecutive months. In order to optimize these strategies, the mechanisms for their effectiveness require further evaluation.
Unwitnessed magnet ingestion in a 5 year-old boy leading to bowel perforation after magnetic resonance imaging: case report of a rare but potentially detrimental complication
Authors: Bailey James R , Eisner Eric A , Edmonds Eric W
Published: July 2012

Background

The ingestion of non-food items in children is a relatively common event, often unwitnessed, unknown, and unreported. For those children brought in for medical evaluation, less than 10% require intervention, and only 1% require surgery. This, however, is not the case for magnet ingestion. Magnets, in plurality, can become attracted to one another through intestinal walls, causing a variety of surgical emergencies.

Case presentation

We present a case of unwitnessed multiple magnet ingestion in a 5 year-old boy who presented to the emergency department with the atypical chief complaint of neck pain. The diagnostic work-up including a neck magnetic resonance imaging (MRI) potentially led to bowel perforations managed definitely by a subsequent exploratory laparotomy. The child had an uneventful postoperative recovery and was discharged to home upon surgical recovery.

Conclusions

Institutions should make all possible efforts to attempt to prevent such potential life-threatening circumstances. We propose a screening tool that can further enhance the care of children who cannot or do not report unwitnessed magnetic ingestion prior to MRI evaluation.
Monitoring diabetes in patients with and without rheumatoid arthritis: a Medicare study
Authors: Bartels Christie M , Saucier Jessica M , Thorpe Carolyn T , Kind Amy JH , Pandhi Nancy , Hansen Karen E , Smith Maureen A
Published: July 2012

Introduction

Diabetes mellitus is a key predictor of mortality in rheumatoid arthritis (RA) patients. Both RA and diabetes increase the risk of cardiovascular disease (CVD), yet understanding of how comorbid RA impacts the receipt of guideline-based diabetes care is limited. The purpose of this study was to examine how the presence of RA affected hemoglobin A1C (A1c) and lipid measurement in older adults with diabetes.

Methods

Using a retrospective cohort approach, we identified beneficiaries ≥65 years old with diabetes from a 5% random national sample of 2004 to 2005 Medicare patients (N = 256,331), then examined whether these patients had comorbid RA and whether they received guideline recommended A1c and lipid testing in 2006. Multivariate logistic regression was used to examine the effect of RA on receiving guideline recommended testing, adjusting for baseline sociodemographics, comorbidities and health care utilization.

Results

Two percent of diabetes patients had comorbid RA (N = 5,572). Diabetes patients with comorbid RA were more likely than those without RA to have baseline cardiovascular disease (such as 17% more congestive heart failure), diabetes-related complications including kidney disease (19% higher), lower extremity ulcers (77% higher) and peripheral vascular disease (32% higher). In adjusted models, diabetes patients with RA were less likely to receive recommended A1c testing (odds ratio (OR) 0.84, CI 0.80 to 0.89) than those without RA, but were slightly more likely to receive lipid testing (OR 1.08, CI 1.01 to 1.16).

Conclusions

In older adults with diabetes, the presence of comorbid RA predicted lower rates of A1c testing but slightly improved lipid testing. Future research should examine strategies to improve A1c testing in patients with diabetes and RA, in light of increased CVD and microvascular risks in patients with both conditions.
Factors Associated With Pain Among Ambulatory Patients With Cancer With Advanced Disease at a Comprehensive Cancer Center
Authors: Stuver Sherri O. , Isaac Thomas , Weeks Jane C. , Block Susan , Berry Donna L. , Davis Roger B. , Weingart Saul N.
Published: July 2012

Younger age, minority race, and recent onset of advanced disease are associated with severe pain among patients with cancer. Recognizing these high-risk groups could inform targeted interventions to address pain care in ambulatory patients with advanced cancer.
To Keep Them From Injustice: Reflections on the Care of Unauthorized Immigrants With Cancer
Authors: Helft Paul R.
Published: July 2012

Current realities in medical economics and reimbursement policies mean most practices cannot offer free care to everyone who needs it. However, a pathway exists for fulfilling our ethical obligation to care for patients irrespective of ability to pay.
Clinical Guidelines, the Politics of Value, and the Practice of Medicine: Physicians at the Crossroads
Authors: Cooper Richard A. , Straus David J.
Published: July 2012

Best practice guidelines are being used to an increasing degree, not only by physicians to improve the level of care, but also by bureaucrats to constrain reimbursement and guide the pathways of care.
Inorganic nutrient availability affects organic matter fluxes and metabolic activity in the soft coral genus Xenia
Authors: Bednarz Vanessa N. , Naumann Malik S. , Niggl Wolfgang , Wild Christian
Published: July 2012

The release of organic matter (OM) by scleractinian corals represents a key physiological process that importantly contributes to coral reef ecosystem functioning, and that is affected by inorganic nutrient availability. While OM fluxes have been studied for several dominant reef taxa, no information is available for soft corals, one of the major benthic groups in tropical reef environments. Thus, this study investigates OM fluxes along with other key physiological parameters (i.e. photosynthesis, respiration and chlorophyll a tissue content) in the common soft coral genus Xenia after a 4-week exposure period to elevated ammonium (N, 20.0 µM), phosphate (P, 2.0 µM) and combined inorganic nutrient enrichment treatment (NP). Corals maintained without nutrient enrichment served as non-treated controls and revealed constant uptake rates for particulate organic carbon (POC) (-0.32 ± 0.16 mg POC m-2 coral surface area h-1), particulate nitrogen (PN) (-0.05 ± 0.02 mg PN m-2 h-1) and dissolved organic carbon (DOC) (-4.8 ± 2.1 mg DOC m-2 h-1). While DOC uptake significantly increased in the N treatment, POC flux was not affected. The P treatment significantly enhanced PN release as well as photosynthesis and respiration rates suggesting an influence by autotrophic carbon acquisition of zooxanthellae endosymbionts on OM fluxes by the coral host. Our physiological findings confirm the significant effect of inorganic nutrient availability on OM fluxes and key metabolic processes for the soft coral Xenia, and provide first clues on OM cycles initiated by soft corals in reef environments exposed to ambient and elevated inorganic nutrient concentrations.
Solubility of nitrogen in marine mammal blubber depends on its lipid composition
Authors: Koopman Heather N. , Westgate Andrew J.
Published: July 2012

Understanding the solubility of nitrogen gas in tissues is a critical aspect of diving physiology, especially for air-breathing tetrapods. Adipose tissue is of particular interest due to the high solubility of nitrogen in lipids. Surprisingly, nothing is known about nitrogen solubility in the blubber of any marine mammal. We tested the hypothesis that N2 solubility is dependent on blubber's lipid composition; most blubber is composed of triacylglycerols, but some toothed whales deposit large amounts of waxes in blubber instead. The solubility of N2 in the blubber of 13 toothed whale species ranged from 0.062-0.107 mL N2/mL oil. Blubber with high wax ester content had higher N2 solubility, observed in the beaked (Ziphiidae) and small sperm (Kogiidae) whales, animals that routinely make long, deep dives. We also measured nitrogen solubility in the specialized cranial acoustic fat bodies associated with echolocation in a Risso's dolphin; values (0.087) were 16% higher than its blubber (0.074). As the acoustic fats of all Odontocetes contain waxes, even if the blubber does not, these tissues may experience greater interaction with N2. These data have implications for our understanding and future modeling of, diving physiology in Odontocetes, as our empirically derived values for nitrogen solubility in toothed whale adipose were up to 40% higher than the numbers traditionally assumed in marine mammal diving models.
Lifestyle-related diseases and individual responsibility through the prism of solidarity
Authors: Buyx Alena , Prainsack Barbara
Published: July 2012

The concept of lifestyle-related diseases and individual responsibility for health has played an important role in debates on the fair allocation of increasingly scarce health-care resources. In this article, we examine this discussion through the prism of solidarity. Based on an understanding of solidarity as shared practices reflecting a collective commitment to carry ‘costs’ (financial, social, emotional or otherwise) to assist others, we analyse frequent arguments in the debate and, in particular, the tool of risk-stratification. We then offer a solidarity-based approach to understanding risk in the context of lifestyle-related diseases, and draw a number of conclusions on how health policy informed by solidarity should approach priority setting in health care.
Imaging in sport and exercise medicine: “a sports physician's outlook and needs”
Authors: McCurdie I
Published: July 2012

Sport and exercise medicine (SEM) is an exciting new medical specialty that thrives on interdisciplinary practice. The SEM physician will usually be found managing a wider, multidisciplinary team of specialists, orchestrating their various inputs to ensure that the most effective management plan is delivered to the patient. One key member of this team is the radiologist, with whom the SEM physician usually has a very close working relationship. Areas of SEM practice that commonly involve significant input from radiologists include the use of appropriate imaging to confirm an accurate diagnosis and to inform management planning (such as decisions on return to play in the elite athlete), various screening and pre-participation assessments and also technical assistance with certain procedures. This article discusses the relationship between the SEM physician and the radiologist across each of these areas, illustrating the important contribution made by imaging services to the specialty of SEM.
Cost Effective Air-Coupled Impact-Echo Sensing for Rapid Detection of Delamination Damage in Concrete Structures
Authors: Shin Sung Woo , Popovics John S. , Oh Taekeun
Published: July 2012

Recently, air-coupled impact-echo (IE) tests for rapid damage detection in concrete structures have been reported, where an acoustically shielded, high sensitivity, pre-polarized air-pressure sensor was employed. However, this sensor is expensive and inconvenient compared with conventional (contact sensor) IE testing systems. In this study, a low cost dynamic microphone is evaluated with regard to characterization of delamination damage in a concrete slab using the IE method. Artificial delaminations with various sizes and depths are simulated by embedding plastic double sheets into a concrete slab. Results from both point and areal scanning IE tests that were carried out over the test slab surface are reported. Results show that the dynamic microphone successfully captures impact-echo signals in a contactless manner and without acoustic shielding. Near-surface delaminations in the concrete slab were clearly identified, where the obtained results are equivalent to those results obtained with the high sensitivity sensor.
FBG Sensors Encapsulated into 7-Wire Steel Strand for Tension Monitoring of a Prestressing Tendon
Authors: Kim Jae-Min , Kim Hyun-Woo , Park Young-Ha , Yang In-Hwan , Kim Young-Sang
Published: July 2012

This paper proposes a novel method for in-service evaluation of prestress forces of 7–wire prestressing strand which is frequently employed for prestressed concrete (PSC) bridge girders. The proposed method incorporates the fiber Bragg grating (FBG) sensor system. The straight king wire of the 7-wire prestressing strand is replaced with an instrumented steel tube in which the FBG sensor is embedded. Since the strain of the strand can easily be measured using the in-strand FBG sensor, it is possible to monitor the prestress force of the strand during the in-service state as well as during the jacking process. To demonstrate the effectiveness of the proposed strand with the FBG sensor system, the proposed method is applied to 1 m, 7 m, 64 m and 43 m long strand prototypes to evaluate the prestress forces, and they are respectively tested under different conditions. The experimental results show that the proposed in-strand FBG sensor system is viable for monitoring the prestress forces of the prestressing strand.
Robotic SHM and Model-Based Positioning System for Monitoring and Construction Automation
Authors: Myung Hyun , Jung Jongdae , Jeon Haemin
Published: July 2012

As civil infrastructures get larger and more complex, the development of robot technologies that help to construct, monitor, inspect, and manage civil infrastructures is in need. In this paper, we introduce two major robot technologies for construction and monitoring of civil infrastructures. The first one is the beacon-based localization technology for the robust localization of the robot and human. A novel beacon-based localization method is proposed where it utilizes the map information of the structure and the signal propagation model. The second one is the modular robot system for structural health monitoring (SHM) of large structures. To develop an SHM system that directly measures the deformation of the structure using low-cost sensor, a paired structured light (SL)-based modular robot system is proposed. The proposed module which uses one or two actuated lasers and a camera in pair is inexpensive to implement and it can directly measure the accurate relative deformation between any two locations on the structure. To demonstrate the feasibility and capability of the proposed methods, experimental results have been shown for each technology.
Acropolis of Athens: Recording, Modeling and Visualising a Major Archaeological Site
Authors: Tsingas V.
Published: July 2012

This paper presents the project “Development of Geographic Information Systems at the Acropolis of Athens”, financed by the European Union and the Government of Greece. The Acropolis of Athens is one of the major archaeological sites world-wide included in the UNESCO World Heritage list. The project started in June 2007 and finished in May 2009. The paper presents the project's aims and gives a description of the deliverables and the specifications, as well as the project difficulties. It was a complex project including a wide range of works, from classical geodetic and photogrammetric works to 3D modeling and GIS development.

The main tasks of the project were the establishment of a polygonometric network, the production of DSM and orthophotomosaics of the top view of the hill and of the walls' facades, the terrestrial laser scanning and 3D modeling of the Acropolis rock, the walls and the Erehtheion, the development of a geospatial database and finally the development of GIS applications to access and manage the data.
Investigation of Salt Weathering on Stone Monuments by Use of a Modern Wireless Sensor Network Exemplified for the Rock-Cut Monuments in Petra/Jordan – A Research Project (2010 – 2013)
Authors: Heinrichs K. , Azzam R.
Published: July 2012

Experience has shown that salt weathering represents a major cause of damage on stone monuments. Despite many years of intensive research, processes of salt weathering still can not be explained satisfactorily. The lack of knowledge impedes reliable damage prognosis as well as selection and implementation of appropriate and sustainable monument preservation measures. The overall aim of the “petraSalt” research project is to improve knowledge of salt weathering on stone monuments. The methodological approach combines assessment of weathering damage and monument exposure characteristics, laboratory analysis of salt loading and continuous monument environmental monitoring by use of innovative wireless sensor network technology. In order to ensure findings of high transferability, the rock-cut monuments of Petra / Jordan were selected for studies, as stone type and spectra of monument exposure regimes, environmental influences, salt loading and weathering damage are very representative for a multitude of stone monuments worldwide.
Antikommunismus als politischer Leitfaden des Vatikans?
Authors: Schulze Thies
Published: July 2012

Vorspann

Im Frühjahr 1933 überraschte Papst Pius XI. die Welt. Er lobte Hitler als den einzigen Staatsmann, der etwas gegen den Kommunismus unternehme, und gab damit der Hoffnung Ausdruck, in der neuen deutschen Regierung einen Bündnispartner gegen die „rote Gefahr“ finden zu können. Thies Schulze, Historiker an der Universität Münster, analysiert die Ursachen dieser überraschenden Wende und untersucht die Folgen der merklichen Annäherung, zu denen nicht zuletzt die Aufnahme der Verhandlungen für das Reichskonkordat zählte. Sein Beitrag wirft somit auch ein neues Licht auf die Scholder/Repgen-Debatte, die in der letzten Ausgabe der VfZ historisiert wurde.
“The Present Obfuscation”: Cowper'sTaskand the Time of Climate Change
Authors: Menely Tobias
Published: July 2012

Climate change, I argue, is a catastrophe that resists the revelation promised by apocalyptic narrative. My case study is William Cowper's poemThe Task(1785), which I situate in two climatic contexts: the year of its composition, which saw meteorological extremes caused by the eruption of an Icelandic volcano, and an era of geologic modernity, the Anthropocene, which commenced with the industrial combustion of fossil fuels in the late eighteenth century. As volcanogenic haze migrates in Cowper's descriptions from the countryside to the greenhouse and the imperial city, the poet fails to identify a meteorology with which to distinguish nature's seasonal “revolvency” from eschatological presages or from the modernization process itself—the historical “revolution” embodied by worsening urban pollution. Climate change poses a crisis, in the dual etymological senses of a decision and a turning point, because it unsettles the duration of the present, what returns and endures and so measures alteration.
Beyond Imagining, Imagining Beyond
Authors: Keller Lynn
Published: July 2012

Particularly because the mla lacks a division on environmental literature, it is gratifying that the organization is turning attention to environmental studies through forums such as this one. Many more in the profession than the fourteen hundred members of the Association for Study of Literature and the Environment take some interest in environmental literature and would like to foster sustainability through their teaching or research. Yet the term is problematic: a popular buzzword, its parameters are vague, and consequently the more difficult questions underlying the concept are too easily evaded. Sustainability of what and for whom? we might ask. Are people talking about sustaining complicated, interwoven biotic communities, sustaining humankind, or sustaining a comfortable lifestyle currently enjoyed by the privileged classes around the globe? What are the term's qualitative implications? What constitute appropriate standards for sustainability, and who decides? What political and economic policies will be necessary? Where will we get the motivation, the will to institute them? Where does sustainability intersect with issues of environmental and social justice, and how will we address the many ethical questions it raises?
Neoliberalism, Genre, and “The Tragedy of the Commons”
Authors: Nixon Rob
Published: July 2012

In december 1968 the journal science published “the tragedy of the commons,” a slender tract by the ecologist and geneticist garrett Hardin that became one of the twentieth century's most influential essays. Hardin's thinking resonated in particular with policy makers at the International Monetary Fund, at the World Bank, and at conservative think tanks and kindred neoliberal institutions advocating so-called trickle-down economics, structural adjustment, austerity measures, government shrinkage, and the privatization of resources. Although Hardin's paramount, Malthusian concern was with “overbreeding,” his general critique of the commons has had a far more lasting impact. He memorably encapsulated that critique in a parable that represented the commons as unprofitable and unsustainable, inimical to both the collective and the individual good.1 According to this brief parable, a herdsman faced with the temptations of a common pasture will instinctively overload it with his livestock. As each greed-driven individual strives to maximize the resource for personal gain, the commons collapses to the detriment of all. Together, Hardin's pithy essay title and succinct parable have helped vindicate a neoliberal rescue narrative, whereby privatization through enclosure, dispossession, and resource capture is deemed necessary for averting tragedy.
A note on the difficulties of measuring the thermal conductivity of concrete
Authors: Thompson N. E.
Published: July 2012

Summary

It has been observed that partially saturated concrete takes several hours to reach a steady state when the hot-plate method is used to measure thermal conductivity; theoretically, the time should be far less than one hour. This indicates that moisture movement always takes place. Consideration of the thermal gradients and the measurement times for the hot-wire transient method indicates that moisture movement should affect the measurements. This has been observed experimentally. Other methods are considered, and it is shown that little improvement can be expected from increasing the size of conductivity probes. The intrinsic difficulties of all methods are discussed.
The development and use of a force-moment transducer
Authors: Gupta B. K. , Edwards A. D. , Loveday R. W.
Published: July 2012

Summary

A force-moment transducer which can measure all six components of the reaction at a support of a general skeletal structure subject to general loading has been developed in the Concrete Structures and Technology Section of the Civil Engineering Department of Imperial College. The details of the transducer and some of the difficulties encountered in its production are described.
Anchorage zone stresses in axially post-tensioned members of uniform rectangular section
Authors: Yettram A. L. , Robbins K.
Published: July 2012

Synopsis

Anchorage zone stresses in axially loaded post-tensioned members of uniform rectangular cross-section are determined by using a finite element procedure for the elastic analysis of three-dimensional solids. Particular attention is paid to the distributions of bursting stresses for a wide range of concentration ratios between the dimensions of the anchor plate and the cross-section of the member. The results are compared with those predicted by conventional methods.
A permeability-testing apparatus for concrete
Authors: van der Meulen G. J. R. , van Dijk J.
Published: July 2012

Synopsis

A description is given of a permeability-testing apparatus for concrete with specific reference to the method of sealing the specimen in the permeameter.
Factors influencing the strength of reinforced concrete beams under combined bending and torsion
Authors: Sundara Raja Iyengar K. T. , Vijaya Rangan B.
Published: July 2012

Synopsis

Observations obtained from tests on seventy-five reinforced concrete beams under combined bending and torsion are discussed in detail. The test results are studied in the light of a theory developed by the authors and good agreement is observed between theoretical and test results. The test results are useful for an understanding of the exact interaction between moments, and they bring out the influence of various factors upon the capacity of beams. Further, both tesl and theoretical results suggest that the interaction diagram varies with all the properties of beams.
The mechanism of stabilization of highmagnesia Portland cements by reactive silica under autoclave conditions
Authors: Majumdar A. J. , Rehsi S. S.
Published: July 2012

Synopsis

Factors which play important roles in the mechanism of stabilization of high-magnesia Portland cements by active silicate materials under autoclave conditions have been considered. Among these, reduction in the rate of hydration of uncombined MgO, formation of a magnesium silicate hydrate similar to the natural mineral deweylite and development of substantial strength in autoclaved products are thought to be the principal factors which control the volume expansion of these cements. It is proposed that strength development in these materials is consequent upon the formation of large amounts of the well crystallized 11 Å tobermorite phase. The extra strength generated in autoclaved mixtures of cement when they incorporate active silica may be sufficient to contain the expansive forces generated by the hydration of perielase into brucite. Much Mg(OH)2, very little Ca(OH)2 and some unhydrated MgO are present in the final products in addition to tobermorite. Some information on the microstructure of the stabilized cement as seen with a scanning electron microscope is given.
The mechanism of tensile creep in concrete
Authors: Ward M. A. , Cook D. J.
Published: July 2012

Synopsis

In this paper it is shown that the tensile creep behaviour of concrete cannot be explained fully in terms of the seepage hypothesis of creep. Accordingly a mechanism of creep based upon seepage but modified by time-dependent micro cracking is proposed. This mechanism can provide an explanation for the experimental results available.
The significance of concrete cube tests
Authors: Halstead P. E.
Published: July 2012

Synopsis

An analysis of routine concrete cube tests performed under research laboratory conditions has indicated that the over-all coefficient of variation of the processes of cube making and testing is about 3 % and that the coefficient of variation of concrete cube results in repeated tests of a single cement, performed in accordance with the requirements of Appendix D of British Standard 12:1928, is about 6·5,6,4·5 and 4 % at 3, 7,28 and 56 days respectively, in this particular laboratory. The implications of these levels of variability of test results for tests on cement conducted in accordance with BS 12, and for the design of experiments in which concrete strength is one of the parameters to be measured, are discussed.
The effect of size and shape of specimen upon the unconfined compressive strength of cement-stabilized materials
Authors: Symons I. F.
Published: July 2012

Synopsis

An investigation has been carried out into the effect of the shape and size of the specimen upon the unconfined compressive strength of cement-stabilized gravelsand-clay, well graded sand and fine crushed rock. A range of cement contents was used with each material to give a range of strengths up to about 14 N/mm2 after 7 days' curing. To enable valid comparisons of strength to be made, the specimens were compacted to produce similar dry densities. Relationships were obtained between the strength of cylindrical specimens of different height to diameter ratios and between the strengths of cubes and cylindrical specimens. The average ratios of the strength of cylindrical specimens with a height:diameter ratio of 2:1 to the strength of specimens with a height: diameter ratio of 1:1 were 0·89, 0·74 and 0·65 for 150, 100 and 50 mm diameter specimens respectively. The differences in strength between specimens with height:diameter ratios of 1:1 and 2:1 is thought to be associated with the effect of the end restraint imposed on the specimens by the platens of the testing machine in producing different modes of failure with the specimens of different height. The average ratio for the strength of 150 mm cubes to the strength of 300 mm high by 150 mm diameter cylinders made from the materials studied was found to be 1·29, which agrees closely with the value of 4/3 commonly accepted for concrete test specimens.
Optimum reinforcement of concrete slab elements against combinations of moments and membrane forces
Authors: Morley C. T.
Published: July 2012

Synopsis

The paper presents a method for finding the optimum arrangement ofreinforcement in a concrete slab element subjected to general combinations of moments and membrane forces. The method is based on the study of strain distributions which satisfy certain conditions at the positions where reinforcement is to be provided. For some combinations of stress-resultants, explicit equations can be derived for the required areas of steel: in the special cases of membrane forces only, or of moments only, these equations reduce to previously published results. Some numerical examples are given.