Riparian Wetlands: Mapping

EPA Science Inventory

Riparian wetlands are critical systems that perform functions and provide services disproportionate to their extent in the landscape. Mapping wetlands allows for better planning, management, and modeling, but riparian wetlands present several challenges to effective mapping due t...

[Management of an elderly patient in the emergency room at the end of life : A medical ethics challenge].

PubMed

Michels, G; Nies, R; Ortmann, S; Pfister, R; Salomon, F

2018-04-01

A 94-year-old patient with cardiogenic shock due to myocardial infarction was admitted via the emergency room. A coronary angiography and intensive care were requested. The need for care due to dementia was known. After case discussion in the interdisciplinary and multiprofessional treatment team, the decision for a palliative care concept in the form of symptom control was made in the emergency room, taking into account the patient's medical history, the current situation, and the presumed patient consent. The integration of medical ethics aspects and palliative medicine into "geriatric emergency medicine" will present a challenge in the future.

Optimizing Burn Treatment in Developing Low-and Middle-Income Countries with Limited Health Care Resources (Part 3)

PubMed Central

Atiyeh, B.; Masellis, A.; Conte, F.

2010-01-01

Summary The present review of the literature aims at analysing the challenges facing burn management in low- and middleincome countries and exploring probable modalities to optimize burn management in these countries. In Part I, epidemiology of burns injuries and the formidable challenges for proper management due to limited resources and inaccessibility to sophisticated skills and technologies in low- and middle income countries (LMICs) were presented. Part II discussed the actual state of burn injuries management in LMICs. In Part III of this review strategies for proper prevention and burn care in LMICs will be presented. PMID:21991190

Corrosion Challenges for the Oil and Gas Industry in the State of Qatar

NASA Astrophysics Data System (ADS)

Johnsen, Roy

In Qatar oil and gas has been produced from onshore fields in more than 70 years, while the first offshore field delivered its first crude oil in 1965. Due to the atmospheric conditions in Qatar with periodically high humidity, high chloride content, dust/sand combined with the temperature variations, external corrosion is a big treat to the installations and connecting infrastructure. Internal corrosion in tubing, piping and process systems is also a challenge due to high H2S content in the hydrocarbon mixture and exposure to corrosive aquifer water. To avoid corrosion different type of mitigations like application of coating, chemical treatment and material selection are important elements. This presentation will review the experiences with corrosion challenges for oil & gas installations in Qatar including some examples of corrosion failures that have been seen.

Obesity: challenges to ventilatory control during exercise--a brief review.

PubMed

Babb, Tony G

2013-11-01

Obesity is a national health issue in the US. Among the many physiological changes induced by obesity, it also presents a unique challenge to ventilatory control during exercise due to increased metabolic demand of moving larger limbs, increased work of breathing due to extra weight on the chest wall, and changes in breathing mechanics. These challenges to ventilatory control in obesity can be inconspicuous or overt among obese adults but for the most part adaptation of ventilatory control during exercise in obesity appears remarkably unnoticed in the majority of obese people. In this brief review, the changes to ventilatory control required for maintaining normal ventilation during exercise will be examined, especially the interaction between respiratory neural drive and ventilation. Also, gaps in our current knowledge will be discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Route Planning Software for Lunar Polar Missions

NASA Astrophysics Data System (ADS)

Cunningham, C.; Jones, H.; Amato, J.; Holst, I.; Otten, N.; Kitchell, F.; Whittaker, W.; Horchler, A.

2016-11-01

Rover mission planning on the lunar poles is challenging due to the long, time-varying shadows. This abstract presents software for efficiently planning traverses while balancing competing demands of science goals, rover energy constraints, and risk.

Forensic Evaluation of Deaf Individuals: Challenges and Strategies.

PubMed

Pollard, Robert Q; Berlinski, Brian T

2017-01-01

Forensic evaluation of deaf individuals presents unique challenges due to many examinees' fund of information deficits, potential for language deprivation, and examiners' frequent lack of creativity regarding communication methods. This article describes challenges most frequently encountered in competency to stand trial and criminal responsibility evaluations and offers strategies for overcoming them. The value of employing multiple communication methods, especially the use of illustrations, is emphasized. Suggestions also are offered regarding preparing evaluation reports and effectively communicating "key deaf fundamentals" to legal personnel. Encouragement is offered for qualified, sign-fluent professionals to engage in forensic work.

Motion control of multi-actuator hydraulic systems for mobile machineries: Recent advancements and future trends

NASA Astrophysics Data System (ADS)

Xu, Bing; Cheng, Min

2018-06-01

This paper presents a survey of recent advancements and upcoming trends in motion control technologies employed in designing multi-actuator hydraulic systems for mobile machineries. Hydraulic systems have been extensively used in mobile machineries due to their superior power density and robustness. However, motion control technologies of multi-actuator hydraulic systems have faced increasing challenges due to stringent emission regulations. In this study, an overview of the evolution of existing throttling control technologies is presented, including open-center and load sensing controls. Recent advancements in energy-saving hydraulic technologies, such as individual metering, displacement, and hybrid controls, are briefly summarized. The impact of energy-saving hydraulic technologies on dynamic performance and control solutions are also discussed. Then, the advanced operation methods of multi-actuator mobile machineries are reviewed, including coordinated and haptic controls. Finally, challenges and opportunities of advanced motion control technologies are presented by providing an overall consideration of energy efficiency, controllability, cost, reliability, and other aspects.

A Simple Text File for Curing Rainbow Blindness

NASA Technical Reports Server (NTRS)

Krylo, Robert; Tomlin, Marilyn; Seager, Michael

2008-01-01

This slide presentation reviews the use of a simple text file to work with large, multi-component thermal models that present a post-processing challenge. This complexity is due to temperatures for many components, with varying requirements, need to be examined and that false color temperature maps, or rainbows, provide a qualitative assessment of results.

Assessing the gene content of the megagenome: sugar pine (Pinus lambertiana)

Treesearch

Daniel Gonzalez-Ibeas; Pedro J. Martinez-Garcia; Randi A. Famula; Annette Deflino-Mix; Kristian A. Stevens; Carol A. Loopstra; Charles H. Landley; David B. Neale; Jill L. Wegryzn

2016-01-01

Sugar pine (Pinus lambertiana Douglas) is within the subgenus Strobus with an estimated genome size of 31 Gbp. Transcriptomic resources are of particular interest in conifers due to the challenges presented in their megagenomes for gene identification. In this study, we present the first comprehensive survey of the P. lambertiana...

Anesthesia for a Rare Case of Uncorrected Pentalogy of Fallot Undergoing Craniotomy and Drainage of Brain Abscess.

PubMed

Marulasiddappa, Vinay; Raghavavendra, B S

2015-07-01

Children with uncorrected cyanotic congenital heart diseases can present for non cardiac surgeries. They pose several challenges to the Anaesthesiologist, especially when they are posted for emergency surgery, due to the complex haemodynamic changes secondary to the heart disease. Pentalogy of Fallot (POF) is a rare form of congenital heart disease characterized by the association of Tetralogy of Fallot (TOF) with an atrial septal defect (ASD). TOF is the leading cause of intracardiac right to left shunt and is the commonest type of cyanotic congenital heart disease to cause a brain abscess. Children with POF presenting with brain abscess pose several challenges to the anaesthesiologist due to the altered haemodynamics and warrant a meticulous anaesthetic plan. There are very few case reports of Anaesthesia management of a child with Pentalogy of Fallot (POF) presenting for non cardiac surgery. We report the anaesthetic management of a rare case of a 5-year-old child with uncorrected POF, who presented to our Superspeciality hospital with a brain abscess and underwent an emergency craniotomy with drainage of the brain abscess successfully.

Duodenoduodenal intussusception: Report of three challenging cases with literature review.

PubMed

Pradhan, Dinesh; Kaur, Neeraj; Nagi, Birinder

2015-01-01

Small bowel intussusception is an uncommon condition with cases of duodenoduodenal intussusception (DDI) being exceptionally rare. Adult intussusception occurs infrequently and differs from childhood intussusception in its presentation, etiology, and treatment. DDI is very unusual due to the fixed position of the duodenum within the retroperitoneum. The lead point usually is hamartomatous polyp, adenoma, or adenocarcinoma. Only few cases of DDI in adults have been reported in the literature. We herein report a series of three cases of DDI encountered in a tertiary level research institute. All cases had underlying abnormality acting as lead point with different etiologies. DDI is a challenging condition due to its rarity and nonspecific presentation and should be considered in the differential diagnosis of gastric outlet obstruction, pancreatitis, and obstructive jaundice. We elaborate this condition with a detailed review of the literature to gain a better understanding of its clinical features and enable early diagnosis.

A case of distal extrahepatic cholangiocarcinoma with two positive resection margins

PubMed Central

Warner, Wayne A.; Ramcharan, Wesley; Harnanan, Dave; Umakanthan, Srikanth; Maharaj, Ravi

2016-01-01

Cholangiocarcinoma is an uncommon primary malignancy of the biliary tract that is challenging to diagnose and treat effectively due to its relatively silent and late clinical presentation. The present study reports a case of a 60-year-old male with distal extrahepatic cholangiocarcinoma with a 3-week history of painless obstructive jaundice symptoms and subjective weight loss. Imaging revealed an obstructing lesion in the common bile duct, just distal to the entrance of the cystic duct. Pathology revealed moderately differentiated cholangiocarcinoma with two positive proximal resection margins. The two positive resection margins presented a challenge during surgery and points to an urgent need for further studies to better illuminate diagnostic and therapeutic options for patients with similar clinicopathological presentation. PMID:27895774

A case of distal extrahepatic cholangiocarcinoma with two positive resection margins.

PubMed

Warner, Wayne A; Ramcharan, Wesley; Harnanan, Dave; Umakanthan, Srikanth; Maharaj, Ravi

2016-11-01

Cholangiocarcinoma is an uncommon primary malignancy of the biliary tract that is challenging to diagnose and treat effectively due to its relatively silent and late clinical presentation. The present study reports a case of a 60-year-old male with distal extrahepatic cholangiocarcinoma with a 3-week history of painless obstructive jaundice symptoms and subjective weight loss. Imaging revealed an obstructing lesion in the common bile duct, just distal to the entrance of the cystic duct. Pathology revealed moderately differentiated cholangiocarcinoma with two positive proximal resection margins. The two positive resection margins presented a challenge during surgery and points to an urgent need for further studies to better illuminate diagnostic and therapeutic options for patients with similar clinicopathological presentation.

Challenging clinical presentations of pernicious anemia.

PubMed

Oo, Thein Hlaing; Rojas-Hernandez, Cristhiam Mauricio

2017-09-01

Pernicious anemia (PA) is an autoimmune disease of multifactorial etiologies characterized by autoimmune chronic atrophic gastritis, cobalamin deficiency (CD) due to defective absorption of dietary cobalamin from the terminal ileum, and by the presence of intrinsic factor and parietal cell antibodies. PA is a very common cause of CD-related anemia worldwide. Despite advances in the understanding molecular biology and pathophysiology of PA, the diagnosis of PA remains challenging in many circumstances for many clinicians because of its diverse clinical manifestations and the limitations of currently available diagnostic tools. Diagnostic dilemmas could occur when patients with PA present with spuriously normal or high cobalamin levels, normocytic or microcytic anemia, non-anemic macrocytosis, autoimmune hemolytic anemia, pseudo-thrombotic microangiopathy, hyperhomocysteinemia-associated thromboembolism, pseudoleu-kemia, bone marrow failure, bone marrow ring sideroblasts, and neurologic manifestations without anemia or macrocytosis. Herein, we provide an overview of the challenging clinical presentations of PA, diagnostic approach, and management.

Quantifying Uncontrolled Air Emissions from Two Florida Landfills

EPA Science Inventory

Landfill gas emissions, if left uncontrolled, contribute to air toxics, climate change, trospospheric ozone, and urban smog. Measuring emissions from landfills presents unique challenges due to the large and variable source area, spatial and temporal variability of emissions, and...

Professional Carers' Experiences of Caring for Individuals with Intellectual Disability and Dementia: A Review of the Literature

ERIC Educational Resources Information Center

Cleary, Josephine; Doody, Owen

2017-01-01

The number of people with intellectual disability living into old age and developing dementia continues to increase. Dementia presents a wide range of challenges for staff due to progressive deterioration. This article presents the findings from a narrative literature review of professional caregivers' experiences of caring for individuals with…

Radiation Test Challenges for Scaled Commerical Memories

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Ladbury, Ray L.; Cohn, Lewis M.; Oldham, Timothy

2007-01-01

As sub-100nm CMOS technologies gather interest, the radiation effects performance of these technologies provide a significant challenge. In this talk, we shall discuss the radiation testing challenges as related to commercial memory devices. The focus will be on complex test and failure modes emerging in state-of-the-art Flash non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs), which are volatile. Due to their very high bit density, these device types are highly desirable for use in the natural space environment. In this presentation, we shall discuss these devices with emphasis on considerations for test and qualification methods required.

Diverticular disease of the colon presenting as pyometra: a case report.

PubMed

Pankaja, Susmita; Rrukaj, Astrit; Bathula, Uma

2014-05-04

Pyometra can be caused by various etiologies. We present a rare case of diverticular disease of the colon presenting as pyometra. This type of presentation can be challenging even for an astute clinician. A 74-year-old Caucasian woman with a history of pyometra was referred to our gynecology clinic as an urgent case. She was obese, diabetic and hypertensive. Due to the patient profile and the clinical presentation, clinicians were misled toward a diagnosis of possible endometrial cancer. After further investigations, she was found to have colouterine fistula secondary to a diverticular abscess of the sigmoid colon. Persistent vaginal discharge due to pyometra can be caused by diverticular disease of the colon. Clinicians should be aware of this important differential diagnosis.

New plastic recycling technology

EPA Science Inventory

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy de...

Real Time Quality Control Methods for Cued EMI Data Collection

DTIC Science & Technology

2016-01-12

of magnetic geology creating false source locations;  out of the remaining 78 recollects that were due to legitimate sources (i.e., a metal...White River Technologies January 2016 The magnetic geology at the site presented the most significant challenge to the technology and...object, magnetic geology , etc.); however, many of the reacquires due to common errors such as inaccurate target picking could be replaced by in-field

Immune challenges and visual signalling in tree frogs

NASA Astrophysics Data System (ADS)

Desprat, Julia L.; Lengagne, Thierry; Mondy, Nathalie

2017-04-01

In animals, mate-choice is often based on sexual signals that carry information and help the receiver make the best choice to improve the receiver's fitness. Orange visual sexual signals have been hypothesised to carry immune information because they are often due to carotenoid pigments which are also involved in immunity response. Although many studies have focused on the direct relationships between coloration and immunocompetence, few studies have simultaneously studied immunocompetent response and coloration variation after an immune challenge. We tested this hypothesis on starved and ad libitum-fed males of the European tree frog Hyla arborea. Our results show that male coloration is not a reliable indicator of its immune response capacity in this species. However, after an immune challenge induced by a PHA ( Phaseolus vulgaris phytohaemagglutinin) injection, starved males presented a significant coloration loss and this alteration was related to the immune response intensity. Taken together, these results suggest that the brighter (lighter) coloration may be used as a cue by female to exclude males with a recent immune challenge, due to diseases or parasites for example.

Skin cancers in albinos in a teaching Hospital in eastern Nigeria - presentation and challenges of care.

PubMed

Opara, Kingsley O; Jiburum, Bernard C

2010-08-25

Albinism is a genetic disorder characterized by lack of skin pigmentation. It has a worldwide distribution but is commoner in areas close to the equator like Nigeria. Skin cancers are a major risk associated with albinism and are thought to be a major cause of death in African albinos. Challenges faced in the care of these patients need to be highlighted in order to develop a holistic management approach with a significant public health impact. The aim of the study was to determine the pattern of skin cancers seen in Albinos, and to highlight problems encountered in their management. Case records of albinos managed in Imo state University teaching Hospital from June 2007 to May 2009 were reviewed. The data obtained was analyzed using descriptive statistics. In the period under review, albinos accounted for 67% of patients managed for primary skin cancers. There were twenty patients with thirty eight (38) lesions. Sixty one percent of the patients were below 40 years. Average duration of symptoms at presentation was 26 months. The commonest reason for late presentation was the lack of funds. Squamous cell carcinoma was the commonest histologic variant. Most patients were unable to complete treatment due to lack of funds. Albinism appears to be the most important risk factor in the development of skin cancers in our environment. Late presentation and poor rate of completion of treatment due to poverty are major challenges.

Susceptibility of Redundant Versus Singular Clock Domains Implemented in SRAM-Based FPGA TMR Designs

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.; Pellish, Jonathan

2016-01-01

We present the challenges that arise when using redundant clock domains due to their clock-skew. Radiation data show that a singular clock domain (DTMR) provides an improved TMR methodology for SRAM-based FPGAs over redundant clocks.

Immunology of BVDV vaccines

USDA-ARS?s Scientific Manuscript database

The use of vaccination to control bovine viral diarrhea virus (BVDV) infections presents exceptional challenges due to the nature of the virus, the unique interaction of the virus with the immune system, and its ability to establish persistent infections. The lack of proof reading function during th...

Soil mixing design methods and construction techniques for use in high organic soils.

DOT National Transportation Integrated Search

2015-06-01

Organic soils present a difficult challenge for roadway designers and construction due to the high : compressibility of the soil structure and the often associated high water table and moisture content. For : other soft or loose inorganic soils, stab...

A Review on Potential Issues and Challenges in MR Imaging

PubMed Central

Kanakaraj, Jagannathan

2013-01-01

Magnetic resonance imaging is a noninvasive technique that has been developed for its excellent depiction of soft tissue contrasts. Instruments capable of ultra-high field strengths, ≥7 Tesla, were recently engineered and have resulted in higher signal-to-noise and higher resolution images. This paper presents various subsystems of the MR imaging systems like the magnet subsystem, gradient subsystem, and also various issues which arise due to the magnet. Further, it also portrays finer details about the RF coils and transceiver and also various limitations of the RF coils and transceiver. Moreover, the concept behind the data processing system and the challenges related to it were also depicted. Finally, the various artifacts associated with the MR imaging were clearly pointed out. It also presents a brief overview about all the challenges related to MR imaging systems. PMID:24381523

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamran, Mudassar, E-mail: kamranm@mir.wustl.edu; Fowler, Kathryn J., E-mail: fowlerk@mir.wustl.edu; Mellnick, Vincent M., E-mail: mellnickv@mir.wustl.edu

Primary aortic neoplasms are rare. Aortic sarcoma arising after endovascular aneurysm repair (EVAR) is a scarce subset of primary aortic malignancies, reports of which are infrequent in the published literature. The diagnosis of aortic sarcoma is challenging due to its non-specific clinical presentation, and the prognosis is poor due to delayed diagnosis, rapid proliferation, and propensity for metastasis. Post-EVAR, aortic sarcomas may mimic other more common aortic processes on surveillance imaging. Radiologists are rarely knowledgeable about this rare entity for which multimodality imaging and awareness are invaluable in early diagnosis. A series of three pathologically confirmed cases are presented tomore » display the multimodality imaging features and clinical presentations of aortic sarcoma arising after EVAR.« less

Lichenoid Dermatitis of the Vulva: Diagnosis and Differential Diagnosis for the Gynecologic Pathologist.

PubMed

Lewin, Marc R; Hick, Ryan W; Selim, Maria A

2017-09-01

Inflammatory processes affecting the vulva may present a unique challenge due to location specific changes. Different factors are behind the intricacy in the presentation of vulvar dermatoses. First, the vulva is lined by different epithelia (hair-bearing keratinized epithelium, modified mucosa, and mucosa). Furthermore, among other factors, this organ is exposed to friction, occlusion, and trauma. Lastly, as there is a tendency to look for health care advice at an advanced stage of the disease, the lesion may be modified by secondary changes due to self-treatment. This article describes the clinical presentation and pathologic features of vulvar dermatoses with a lichenoid pattern and highlights practical points for their diagnoses.

Lead toxicity and endoscopic removal of ingested firearm cartridges.

PubMed

Hatten, B W; Bueso, A; Craven, P; Hendrickson, R G; Horowitz, B Z

2013-06-01

Lead toxicity from the ingestion of a lead foreign body has been described in several case reports. Management of ingested live ammunition presents its own challenges due to the risk of accidental discharge. A safe and effective method of retrieving a live cartridge must be considered. We present two cases of lead toxicity due to intact firearm cartridge ingestion with the removal of the cartridges via endoscopy. The first case is of severe pediatric lead toxicity due to the ingestion of 30-mm rifle cartridges. The second case is an adult ingestion of .22 caliber cartridges resulting in mild lead toxicity. These cases illustrate a diagnostic dilemma in both the diagnosis of lead toxicity and the removal of live ammunition from the stomach.

The Effects of Race Conditions When Implementing Single-Source Redundant Clock Trees in Triple Modular Redundant Synchronous Architectures

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; Kim, Hak S.; Phan, Anthony M.; Seidleck, Christina M.; Label, Kenneth A.; Pellish, Jonathan A.; Campola, Michael J.

2016-01-01

We present the challenges that arise when using redundant clock domains due to their time-skew. Radiation data show that a singular clock domain provides an improved triple modular redundant (TMR) scheme over redundant clocks.

A Nitrogen Physical Input-Output Table (PIOT) Model for Illinois

EPA Science Inventory

Nitrogen (N) presents an important challenge for sustainability due to its role in providing goods and services to society, since release of N beyond its intended use has many negative consequences. Several systems modeling approaches have been developed to understand the tradeof...

Biological approaches for addressing the grand challenge of providing access to clean drinking water.

PubMed

Riley, Mark R; Gerba, Charles P; Elimelech, Menachem

2011-03-31

The U.S. National Academy of Engineering (NAE) recently published a document presenting "Grand Challenges for Engineering". This list was proposed by leading engineers and scientists from around the world at the request of the U.S. National Science Foundation (NSF). Fourteen topics were selected for these grand challenges, and at least seven can be addressed using the tools and methods of biological engineering. Here we describe how biological engineers can address the challenge of providing access to clean drinking water. This issue must be addressed in part by removing or inactivating microbial and chemical contaminants in order to properly deliver water safe for human consumption. Despite many advances in technologies this challenge is expanding due to increased pressure on fresh water supplies and to new opportunities for growth of potentially pathogenic organisms.

Biological approaches for addressing the grand challenge of providing access to clean drinking water

PubMed Central

2011-01-01

The U.S. National Academy of Engineering (NAE) recently published a document presenting "Grand Challenges for Engineering". This list was proposed by leading engineers and scientists from around the world at the request of the U.S. National Science Foundation (NSF). Fourteen topics were selected for these grand challenges, and at least seven can be addressed using the tools and methods of biological engineering. Here we describe how biological engineers can address the challenge of providing access to clean drinking water. This issue must be addressed in part by removing or inactivating microbial and chemical contaminants in order to properly deliver water safe for human consumption. Despite many advances in technologies this challenge is expanding due to increased pressure on fresh water supplies and to new opportunities for growth of potentially pathogenic organisms. PMID:21453515

Hydraulic Fracturing Fluid Analysis for Regulatory Parameters - A Progress Report

EPA Pesticide Factsheets

This presentation is a progress report on the analysis of Hydraulic Fracturing Fluids for regulatory compounds outlined in the various US EPA methodologies. Fracturing fluids vary significantly in consistency and viscosity prior to fracturing. Due to the nature of the fluids the analytical challenges will have to be addressed. This presentation also outlines the sampling issues associated with the collection of dissolved gas samples.

Pregnancy and Marfan syndrome

PubMed Central

Goland, Sorel

2017-01-01

Pregnancy in women with Marfan syndrome (MFS) presents challenges to the clinician and the patient due to the increased incidence of maternal complications and involvement of the fetus, and deserves special consideration. The leading cause of morbidity and mortality in MFS is aortic dissection. This article presents an extensive review of available clinical information and provides recommendations for the management of patients with MFS during pregnancy. PMID:29270376

Systematic Evaluation of Professional Performance: Legally Supported Procedure and Process.

ERIC Educational Resources Information Center

Kerl, Stella Beatriz; Garcia, John L.; McCullough, C. Sue; Maxwell, Melissa Elaine

2002-01-01

Legal challenges to counseling students' dismissal that are based on interpersonal or clinical incompetence require sound systematic academic evaluation and adherence to procedural and substantive due process. Presents an examination of professional competency from counselor education and legal perspectives, an evaluation procedure and process,…

Applications of Nano Reactive Materials in Remediation of Persistence Organic Pollutants in Sediments and Groundwater - Presentation

EPA Science Inventory

Remediation of sediments and water contaminated hydrophobic organic chemicals (HOCs) such as polychlorinated biphenyls (PCBs) remains a scientific and technical challenge. PCBs-contaminated sediments are ubiquitous despite the production and use of PCBs was banned in 1979 due to...

Measurement of Emissions from Produced Water Ponds: Upstream Oil and Gas Study #1; Final Report

EPA Science Inventory

Significant uncertainty exists regarding air pollutant emissions from upstream oil and gas production operations. Oil and gas operations present unique and challenging emission testing issues due to the large variety and quantity of potential emissions sources. This report summ...

Myomectomy for retained placenta due to incarcerated fibroid mass.

PubMed

Mbamara, S U; Daniyan, Abc; Osaro, Ejenobo; Mbah, I C

2015-01-01

Retained placenta is one of the most common complications of preterm delivery and/or mid-trimester miscarriage. It is an important cause of increased maternal morbidity and sometimes mortality especially in developing countries. It is associated with several complications that could be tasking to the facility and of great challenge to the obstetrician. Here we present a very rare event in obstetrics which is retained placenta due to incarcerated, posteriorly-sited fibroid that was successfully managed with myomectomy.

Redo thoracic endovascular aortic repair due to endoleak with celiac artery snorkeling.

PubMed

Planer, David; Bliagos, Dimitrios; Gray, William A

2011-10-01

Reintervention due to endoleak of aortic endograft repair is often challenging. Herein, we report endovascular endoleak repair in a patient with previous thoracic and abdominal endovascular grafts with extensive coverage of the aorta. The present technique included snorkeling of the celiac trunk to preserve antegrade flow in the celiac artery and to maintain future options for reintervention. Copyright © 2011 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

High-risk Trans-Catheter Aortic Valve Replacement in a Failed Freestyle Valve with Low Coronary Height: A Case Report.

PubMed

Karimi, Ashkan; Pourafshar, Negiin; Dibu, George; Beaver, Thomas M; Bavry, Anthony A

2017-06-01

A 55-year-old male with a history of two prior cardiac surgeries presented with decompensated heart failure due to severe bioprosthetic aortic valve insufficiency. A third operation was viewed prohibitively high risk and valve-in-valve trans-catheter aortic valve replacement was considered. There were however several high-risk features and technically challenging aspects including low coronary ostia height, poor visualization of the aortic sinuses, and difficulty in identification of the coplanar view due to severe aortic insufficiency, and a highly mobile aortic valve mass. After meticulous peri-procedural planning, trans-catheter aortic valve replacement was carried out with a SAPIEN 3 balloon-expandable valve without any complication. Strategies undertaken to navigate the technically challenging aspects of the case are discussed.

[Community immersion program at Geneva medical school: a fifteen-year experience].

PubMed

Chastonay, Philippe; Klohn, Axel Max; Zesiger, Véronique; Soguel, Ludivine; Kabengele, Emmanuel; Vu, Nu Viet; Bernheim, Laurent

2013-02-20

Over the past decades there have been many new developments in medical education due to new public health challenges and to new learning theories. Medical schools throughout the world have adapted to these challenges in adopting community-based learning activities, an approach that the World Health Organization has promoted. The aim of the present article is to describe the characteristics, as well as the evolution, of such a community-based training program which has been implemented over 15 years at the Faculty of medicine of the University of Geneva and to present some evaluation data addressing students' perception, achievement of learning objectives as well as interactions between students and the community.

Evaluation and comparison of current fetal ultrasound image segmentation methods for biometric measurements: a grand challenge.

PubMed

Rueda, Sylvia; Fathima, Sana; Knight, Caroline L; Yaqub, Mohammad; Papageorghiou, Aris T; Rahmatullah, Bahbibi; Foi, Alessandro; Maggioni, Matteo; Pepe, Antonietta; Tohka, Jussi; Stebbing, Richard V; McManigle, John E; Ciurte, Anca; Bresson, Xavier; Cuadra, Meritxell Bach; Sun, Changming; Ponomarev, Gennady V; Gelfand, Mikhail S; Kazanov, Marat D; Wang, Ching-Wei; Chen, Hsiang-Chou; Peng, Chun-Wei; Hung, Chu-Mei; Noble, J Alison

2014-04-01

This paper presents the evaluation results of the methods submitted to Challenge US: Biometric Measurements from Fetal Ultrasound Images, a segmentation challenge held at the IEEE International Symposium on Biomedical Imaging 2012. The challenge was set to compare and evaluate current fetal ultrasound image segmentation methods. It consisted of automatically segmenting fetal anatomical structures to measure standard obstetric biometric parameters, from 2D fetal ultrasound images taken on fetuses at different gestational ages (21 weeks, 28 weeks, and 33 weeks) and with varying image quality to reflect data encountered in real clinical environments. Four independent sub-challenges were proposed, according to the objects of interest measured in clinical practice: abdomen, head, femur, and whole fetus. Five teams participated in the head sub-challenge and two teams in the femur sub-challenge, including one team who tackled both. Nobody attempted the abdomen and whole fetus sub-challenges. The challenge goals were two-fold and the participants were asked to submit the segmentation results as well as the measurements derived from the segmented objects. Extensive quantitative (region-based, distance-based, and Bland-Altman measurements) and qualitative evaluation was performed to compare the results from a representative selection of current methods submitted to the challenge. Several experts (three for the head sub-challenge and two for the femur sub-challenge), with different degrees of expertise, manually delineated the objects of interest to define the ground truth used within the evaluation framework. For the head sub-challenge, several groups produced results that could be potentially used in clinical settings, with comparable performance to manual delineations. The femur sub-challenge had inferior performance to the head sub-challenge due to the fact that it is a harder segmentation problem and that the techniques presented relied more on the femur's appearance.

Pencil Beam Scanning Proton Therapy for Rhabdomyosarcoma of the Biliary Tract.

PubMed

Pater, Luke; Turpin, Brian; Mascia, Anthony

2017-10-05

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood with 250-350 cases diagnosed annually in the United States. Biliary tract rhabdomyosarcoma is rare, representing <1% of the RMS cases. Due to its location, resection is clinically challenging, and functional complications exist and persist from biliary obstruction. The anatomical location of this tumor presents both opportunities and challenges for pencil beam scanning proton therapy. Proton therapy offers a dosimetric and clinical advantage by sparing the healthy liver, stomach, contra-lateral kidney and bowel. Motion management and anatomical variations, such as intestinal filling or weight loss, requiring routine dosimetric evaluation and possible adaptive treatment planning, present challenges for the use of proton therapy. By taking advantage of the superior dose distribution of proton radiation, assessing the impact of tumor and anatomy motion, and performing regular dose evaluations, biliary tract RMS is an ideal diagnosis for pencil beam scanning proton therapy.

Pneumonia Updates on Legionella, Chlamydophila, and Mycoplasma Pneumonia

PubMed Central

Sharma, Lokesh; Losier, Ashley; Tolbert, Thomas; Dela Cruz, Charles S.; Marion, Chad R.

2017-01-01

SUMMARY CAP due to Legionella, Chlamydophyla, or Mycoplasma continues to be a diagnostic challenge due to the nonspecific clinical and radiographic presentations. The vague clinical presentations of atypical CAP contribute to its underdiagnosis and under-reporting. Advancements in diagnostic techniques bring hope to rapid and accurate diagnosis of atypical CAP. Macrolides and respiratory fluoroquinolones are currently the antibiotics of choice, but this may change in the near future as more antibiotics resistance patterns emerge for atypical CAP. Several controversies still exist in atypical CAP, underscoring the need for continued investigation of preventing atypical CAP and determine its association with chronic lung diseases. PMID:28159161

The Effects of Race Conditions when Implementing Single-Source Redundant Clock Trees in Triple Modular Redundant Synchronous Architectures

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; Label, Kenneth A.; Pellish, Jonathan

2016-01-01

We present the challenges that arise when using redundant clock domains due to their clock-skew. Heavy-ion radiation data show that a singular clock domain (DTMR) provides an improved TMR methodology for SRAM-based FPGAs over redundant clocks.

Using Feedback Strategies to Improve Peer-Learning in Welding

ERIC Educational Resources Information Center

Chan, Selena; Leijten, Flip

2012-01-01

Due to safety considerations, students' practice and learning of welding is conducted within individual welding booths. The booth setting presents some challenges to student learning as collaborative learning within a workshop learning environment is compromised. The project reported in this paper, established peer-learning (i.e., students…

Students' Framing of Laboratory Exercises Using Infrared Cameras

ERIC Educational Resources Information Center

Haglund, Jesper; Jeppsson, Fredrik; Hedberg, David; Schönborn, Konrad J.

2015-01-01

Thermal science is challenging for students due to its largely imperceptible nature. Handheld infrared cameras offer a pedagogical opportunity for students to see otherwise invisible thermal phenomena. In the present study, a class of upper secondary technology students (N = 30) partook in four IR-camera laboratory activities, designed around the…

Reasons for Suboptimal Learning in Medical Microbiology

ERIC Educational Resources Information Center

Struwig, Magdalena C.; Beylefeld, Adriana A.; Joubert, Georgina

2016-01-01

Medical microbiology presents a challenge to undergraduate students, mostly due to its extensive content and complexity of unfamiliar terminology. In addition to a narrative review of the literature, we report findings on students' motivation for and approach to learning in the Infections module of an undergraduate medical curriculum, and their…

Career Counseling with Undocumented Latino Youth: A Qualitative Analysis of School Counselors

ERIC Educational Resources Information Center

Storlie, Cassandra Ann

2013-01-01

The career development trajectory of undocumented Latino youth can present unique challenges for school counselors. Undocumented Latino youth have few career choices due to holding different values from the majority culture, realistic fears of deportation, restrictions in obtaining lawful employment, and having an unconventional pathway to…

Methods of Oil Detection in Response to the Deepwater Horizon Oil Spill

EPA Science Inventory

Detecting oil in the northern Gulf of Mexico following the Deepwater Horizon oil spill presented unique challenges due to the spatial and temporal extent of the spill and the subsequent dilution of oil in the environment. Over time, physical, chemical, and biological processes a...

Comparison of fatigue analysis approaches for hot-mix asphalt to ensure a state of good repair.

DOT National Transportation Integrated Search

2013-10-01

Fatigue cracking is a primary form of distress in hot-mix asphalt. The long-term nature of fatigue due to repeated : loading and aging and its required tie to pavement structure present challenges in terms of evaluating mixture : resistance. This pro...

Multimodality Imaging Approach towards Primary Aortic Sarcomas Arising after Endovascular Abdominal Aortic Aneurysm Repair: Case Series Report.

PubMed

Kamran, Mudassar; Fowler, Kathryn J; Mellnick, Vincent M; Sicard, Gregorio A; Narra, Vamsi R

2016-06-01

Primary aortic neoplasms are rare. Aortic sarcoma arising after endovascular aneurysm repair (EVAR) is a scarce subset of primary aortic malignancies, reports of which are infrequent in the published literature. The diagnosis of aortic sarcoma is challenging due to its non-specific clinical presentation, and the prognosis is poor due to delayed diagnosis, rapid proliferation, and propensity for metastasis. Post-EVAR, aortic sarcomas may mimic other more common aortic processes on surveillance imaging. Radiologists are rarely knowledgeable about this rare entity for which multimodality imaging and awareness are invaluable in early diagnosis. A series of three pathologically confirmed cases are presented to display the multimodality imaging features and clinical presentations of aortic sarcoma arising after EVAR.

Challenges in conducting psychiatry studies in India

PubMed Central

Kharawala, Saifuddin; Dalal, Jeroze

2011-01-01

A large number of psychiatry studies are conducted in India. Psychiatry studies are complex and present unique challenges in the Indian setting. Ethical issues pertaining to the risk of worsening of illness, use of placebo and validity of informed consents are commonly faced. Site selection can be difficult due to the relative paucity of ICH-GCP (International Conference on Harmonisation - Good Clinical Practice) trained psychiatry investigators in India. Recruitment can be challenging due to issues such as strict eligibility criteria, (lack of) availability of caregiver, illness-related considerations, etc. Assessment of the consent capacity of patients is not simple, while structured assessments are not commonly employed. As the illness fluctuates, the consent capacity may change, thus requiring continued assessment of consent capacity. Study patients run the risk of worsening of illness and suicide due to exposure to inactive treatments; this risk is counterbalanced by use of appropriate study designs, as well as the indirect psychotherapeutic support received. Psychiatry studies are associated with a high placebo response. This necessitates conduct of placebo-controlled studies despite the attendant difficulties. Also, the high placebo response is often the cause of failed trials. Rating scales are essential for assessment of drug response. Some rating instruments as well as some rater training procedures may not be suitable for the Indian setting. Technological advancements may increase the procedural complexity but improve the quality of ratings. Psychiatry studies present monitors and auditors with unique scenarios too. Utilization of psychiatry specific training and expertise is recommended to ensure successful conduct of these studies in India. PMID:21584176

Personal, societal, and ecological values of wilderness: Sixth World Wilderness Congress proceedings on research, management, and allocation, Volume I

Treesearch

Alan E. Watson; Greg H. Aplet; John C. Hendee

1998-01-01

The papers contained in Volume I of these Proceedings were originally scheduled for presentation at the Sixth World Wilderness Congress in Bangalore, India, in 1997. Due to a delay of the Congress until 1998, these 27 papers were compiled for publication prior to presentation. Volumes I and II contain papers covering seven topics: protected area systems: challenges,...

An Ultra-Wideband Millimeter-Wave Phased Array

NASA Technical Reports Server (NTRS)

Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

2016-01-01

Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

Ethical Issues in Sports Medicine

PubMed Central

Greenfield, Bruce H.; West, Charles Robert

2012-01-01

Ethical issues present a challenge for health care professionals working with athletes of sports teams. Health care professionals—including the team physician, the physical therapist, and the athletic trainer—are faced with the challenge of returning an athlete to competition as quickly as possible but as safely as possible. Conflicts of interest arise due to conflicting obligations of the team physician to the athlete and other members of the sports organization, including coaches and the team owner. The multiple stakeholders involved in sports teams challenge the traditional notion of confidentiality and autonomy. The aims of this article are to explicate the ethics of sports medicine, highlight the ethical issues, and provide some strategies and suggestions for ethical decision making. PMID:24179585

Myomectomy for Retained Placenta Due to Incarcerated Fibroid Mass

PubMed Central

Mbamara, SU; Daniyan, ABC; Osaro, Ejenobo; Mbah, IC

2015-01-01

Retained placenta is one of the most common complications of preterm delivery and/or mid-trimester miscarriage. It is an important cause of increased maternal morbidity and sometimes mortality especially in developing countries. It is associated with several complications that could be tasking to the facility and of great challenge to the obstetrician. Here we present a very rare event in obstetrics which is retained placenta due to incarcerated, posteriorly-sited fibroid that was successfully managed with myomectomy. PMID:25861539

Adult Brain Tumors and Pseudotumors: Interesting (Bizarre) Cases.

PubMed

Causil, Lazaro D; Ames, Romy; Puac, Paulo; Castillo, Mauricio

2016-11-01

Some brain tumors results are interesting due to their rarity at presentation and overwhelming imaging characteristics, posing a diagnostic challenge in the eyes of any experienced neuroradiologist. This article focuses on the most important features regarding epidemiology, location, clinical presentation, histopathology, and imaging findings of cases considered "bizarre." A review of the most recent literature dealing with these unusual tumors and pseudotumors is presented, highlighting key points related to the diagnosis, treatments, outcomes, and differential diagnosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhancing data from commercial space flights (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sherman, Ariel; Paolini, Aaron; Kozacik, Stephen; Kelmelis, Eric J.

2017-05-01

Video tracking of rocket launches inherently must be done from long range. Due to the high temperatures produced, cameras are often placed far from launch sites and their distance to the rocket increases as it is tracked through the flight. Consequently, the imagery collected is generally severely degraded by atmospheric turbulence. In this talk, we present our experience in enhancing commercial space flight videos. We will present the mission objectives, the unique challenges faced, and the solutions to overcome them.

Integrated Data Modeling and Simulation on the Joint Polar Satellite System Program

NASA Technical Reports Server (NTRS)

Roberts, Christopher J.; Boyce, Leslye; Smith, Gary; Li, Angela; Barrett, Larry

2012-01-01

The Joint Polar Satellite System is a modern, large-scale, complex, multi-mission aerospace program, and presents a variety of design, testing and operational challenges due to: (1) System Scope: multi-mission coordination, role, responsibility and accountability challenges stemming from porous/ill-defined system and organizational boundaries (including foreign policy interactions) (2) Degree of Concurrency: design, implementation, integration, verification and operation occurring simultaneously, at multiple scales in the system hierarchy (3) Multi-Decadal Lifecycle: technical obsolesce, reliability and sustainment concerns, including those related to organizational and industrial base. Additionally, these systems tend to become embedded in the broader societal infrastructure, resulting in new system stakeholders with perhaps different preferences (4) Barriers to Effective Communications: process and cultural issues that emerge due to geographic dispersion and as one spans boundaries including gov./contractor, NASA/Other USG, and international relationships.

Neocortical Temporal Lobe Epilepsy

PubMed Central

Bercovici, Eduard; Kumar, Balagobal Santosh; Mirsattari, Seyed M.

2012-01-01

Complex partial seizures (CPSs) can present with various semiologies, while mesial temporal lobe epilepsy (mTLE) is a well-recognized cause of CPS, neocortical temporal lobe epilepsy (nTLE) albeit being less common is increasingly recognized as separate disease entity. Differentiating the two remains a challenge for epileptologists as many symptoms overlap due to reciprocal connections between the neocortical and the mesial temporal regions. Various studies have attempted to correctly localize the seizure focus in nTLE as patients with this disorder may benefit from surgery. While earlier work predicted poor outcomes in this population, recent work challenges those ideas yielding good outcomes in part due to better localization using improved anatomical and functional techniques. This paper provides a comprehensive review of the diagnostic workup, particularly the application of recent advances in electroencephalography and functional brain imaging, in neocortical temporal lobe epilepsy. PMID:22953057

Promises and challenges in solid-state lighting

NASA Astrophysics Data System (ADS)

Schubert, Fred

2010-03-01

Lighting technologies based on semiconductor light-emitting diodes (LEDs) offer unprecedented promises that include three major benefits: (i) Gigantic energy savings enabled by efficient conversion of electrical energy to optical energy; (ii) Substantial positive contributions to sustainability through reduced emissions of global-warming gases, acid-rain gases, and toxic substances such as mercury; and (iii) The creation of new paradigms in lighting driven by the unique controllability of solid-state lighting sources. Due to the powerful nature of these benefits, the transition from conventional lighting sources to solid-state lighting is virtually assured. This presentation will illustrate the new world of lighting and illustrate the pervasive changes to be expected in lighting, displays, communications, and biotechnology. The presentation will also address the formidable challenges that must be addressed to continue the further advancement of solid-state lighting technology. These challenges offer opportunities for research and innovation. Specific challenges include light management, carrier transport, and optical design. We will present some innovative approaches in order to solve known technical challenges faced by solid-state lighting. These approaches include the demonstration and use of new optical thin-film materials with a continuously tunable refractive index. These approaches also include the use of polarization-matched structures that reduce the polarization fields in GaInN LEDs and the hotly debated efficiency droop, that is, the decreasing LED efficiency at high currents.

Optimization of DNA Barcode Method to Assess Altered Chemical Toxicity due to CYP-mediated Metabolism.

EPA Science Inventory

A drawback of current in vitro chemical testing is that many commonly used cell lines lack chemical metabolism. To address this challenge, we present a method for assessing the impact of cellular metabolism on chemical-based cellular toxicity. A cell line with low endogenous meta...

Exploring the Use of Wikis for Information Sharing in Interdisciplinary Design

ERIC Educational Resources Information Center

Phuwanartnurak, Jiranida

2013-01-01

Interdisciplinary design presents challenges in design collaboration due to the difficulty in communicating and coordinating among disciplines. Many tools have been developed and used to support information sharing in design, and the use of Web technology is becoming increasingly important for the sharing of information within design teams. Wikis…

Space and Power in the Ivory Tower: Effective Space Management and Decision Making

ERIC Educational Resources Information Center

Blanchette, Sandra

2012-01-01

At a time when there are enormous economic pressures on campuses to use resources effectively, space being one of these resources, the academic culture of shared governance, with its fragmented roles for decision making, presents additional challenges. These roles are fragmented due to independent faculty and administrative action. They are…

The Challenges of Teaching Strategic Management: Working toward Successful Inclusion of the Resource-Based View

ERIC Educational Resources Information Center

Schneider, Marguerite; Lieb, Pamela

2004-01-01

The industrial organization economics (IOE) and resource-based view (RBV) schools contribute uniquely to the strategic management curriculum. However, presentation of the RBV is often inadequate or ineffective, in part due to faculty habit, students' conceptualization of knowledge as objective and readily transferable, and course pedagogy. We…

Does My Program Really Make a Difference? Program Evaluation Utilizing Aggregate Single-Subject Data

ERIC Educational Resources Information Center

Burns, Catherine E.

2015-01-01

In the current climate of increasing fiscal and clinical accountability, information is required about overall program effectiveness using clinical data. These requests present a challenge for programs utilizing single-subject data due to the use of highly individualized behavior plans and behavioral monitoring. Subsequently, the diversity of the…

Impacts of Urbanization on Flood and Soil Erosion Hazards in Istanbul, Turkey

ERIC Educational Resources Information Center

Ozacar, Biricik Gozde

2013-01-01

Due to the inappropriate planning and explosive population growth in urban areas, especially in developing countries, sustainable and disaster-safe urbanization has become the most important challenge for governments. Urbanization presents benefits in different ways but has led simultaneously to changes in land use/land cover (LULC), impacting…

Tertiary-Tier PBIS in Alternative, Residential and Correctional School Settings: Considering Intensity in the Delivery of Evidence-Based Practice

ERIC Educational Resources Information Center

Scott, Terrance M.; Cooper, Justin

2013-01-01

Students in alternative, residential, and correctional settings present challenges in the classroom and facility due to the complexity and intensity of their behaviors. In addition, the factors typically associated with these settings including crowding, inconsistency, and conflicting staff perspectives on education and discipline present…

Large airtanker use and outcomes in suppressing wildland fires in the United States

Treesearch

David E. Calkin; Crystal S. Stonesifer; Matthew P. Thompson; Charles W. McHugh

2014-01-01

Wildfire activity in the United States incurs substantial costs and losses, and presents challenges to federal, state, tribal and local agencies that have responsibility for wildfire management. Beyond the potential socioeconomic and ecological losses, and the monetary costs to taxpayers due to suppression, wildfire management is a dangerous occupation. Aviation...

77 FR 40553 - High Seas Driftnet Fishing Moratorium Protection Act; Identification and Certification Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

... management of sharks. Agency actions and recommendations under this rule will be in accordance with U.S... January 4, 2011. Sharks present an array of challenges for fisheries conservation and management due to.... The United States continues to be a leader in promoting shark conservation and management globally. We...

Investigating Teacher Learning Using a Web-Based Writing Platform

ERIC Educational Resources Information Center

Yang, Shih-hsien

2018-01-01

Due to its complex nature and inherent unobservable features, teacher change within a specific context has rarely been investigated despite its importance as an issue in teacher professional development. To meet this challenge, the present study explored how teacher change was nurtured with the support of a web-based writing platform featuring…

The University in Periods of Technological Change: A Historically Grounded Perspective

ERIC Educational Resources Information Center

Amirault, Ray J.; Visser, Yusra L.

2009-01-01

The University has a remarkably enduring history that is due in no small part to its ability to adapt itself whenever intellectual, political, or technological change has occurred. Today's technology revolution, however, presents the University with one of the greatest adaptation challenges it has ever faced in its lengthy history, and the…

Food protein-induced enterocolitis syndrome: a challenging diagnosis.

PubMed

Ribeiro, Andreia; Moreira, Diana; Costa, Cristina; Pinto Pais, Isabel

2018-02-08

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity triggered by food proteins. It may present acutely, with repetitive vomiting, diarrhoea and lethargy leading to dehydration and eventually shock or insidiously with intermittent emesis, chronic diarrhoea or failure to thrive. We describe a paediatric male patient with recurrent sepsis-like episodes of fever, lethargy, ashen-grey skin colouration and vomiting followed by diarrhoea. These episodes were triggered by cow's milk formula and grains. Laboratory tests revealed leucocytosis, thrombocytosis, metabolic acidosis and elevated C reactive protein. After exclusion of other differential diagnoses, the diagnosis of FPIES was established on clinical improvement with withdrawal of the offending food and positive oral food challenge. FPIES diagnosis requires a high index of suspicion and is frequently delayed, which contributes to an increased morbidity. This is due to the wide spectrum of clinical presentations and due to the absence of specific diagnostic tests. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A Theoretical Study of the Hidden Wounds of War: Disenfranchised Grief and the Impact on Nursing Practice

PubMed Central

Aloi, Janice A.

2011-01-01

Combat veterans face enormous challenges upon the return to civilian life, one of which is the ability to integrate incidences of death and killing into a healthy postdeployment life. This paper presents the lived experience of grief and loss resulting from the trauma of war. Social constructionist theory, due to its emphasis on meaning-making, serves as the theoretical framework. The effects of inhibited mourning due to the inability to mourn in combat and lack of nurturing upon returning home are described. Personal excerpts derived from interviews of warfare from veterans that experienced death and killing are presented. It is suggested that combat veterans experience a unique form of grief and therefore require a style of grieving that differs from those that have not served on the battlefield. Regardless of the point of care, nurses are positioned to help with the challenges of readjustment. A better understanding of combat veterans as a disenfranchised group would enable nurses to intervene in ways that contribute to the readjustment process. PMID:22007331

Nanoparticle-Based Manipulation of Antigen-Presenting Cells for Cancer Immunotherapy.

PubMed

Fang, Ronnie H; Kroll, Ashley V; Zhang, Liangfang

2015-11-04

Immunotherapeutic approaches for treating cancer overall have been receiving a considerable amount of interest due to the recent approval of several clinical formulations. Among the different modalities, anticancer vaccination acts by training the body to endogenously generate a response against tumor cells. However, despite the large amount of work that has gone into the development of such vaccines, the near absence of clinically approved formulations highlights the many challenges facing those working in the field. The generation of potent endogenous anticancer responses poses unique challenges due to the similarity between cancer cells and normal, healthy cells. As researchers continue to tackle the limited efficacy of vaccine formulations, fresh and novel approaches are being sought after to address many of the underlying problems. Here the application of nanoparticle technology towards the development of anticancer vaccines is discussed. Specifically, there is a focus on the benefits of using such strategies to manipulate antigen presenting cells (APCs), which are essential to the vaccination process, and how nanoparticle-based platforms can be rationally engineered to elicit appropriate downstream immune responses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gastric volvulus with partial and complete gastric necrosis

PubMed Central

Shukla, Ram Mohan; Mandal, Kartik Chandra; Maitra, Sujay; Ray, Amit; Sarkar, Ruchirendu; Mukhopadhyay, Biswanath; Bhattacharya, Malay

2014-01-01

Here, we report two interesting cases of gastric necrosis in acute gastric volvulus due to eventration of the diaphragm. Both the cases presented with a significant challenge and were managed successfully. The management of the cases is presented and relevant literature is discussed. To the best of our knowledge, this is the first case report of gastric volvulus with gastric necrosis requiring complete and partial gastrectomy in the available English literature. PMID:24604987

Application of advanced diffraction based optical metrology overlay capabilities for high-volume manufacturing

NASA Astrophysics Data System (ADS)

Chen, Kai-Hsiung; Huang, Guo-Tsai; Hsieh, Hung-Chih; Ni, Wei-Feng; Chuang, S. M.; Chuang, T. K.; Ke, Chih-Ming; Huang, Jacky; Rao, Shiuan-An; Cumurcu Gysen, Aysegul; d'Alfonso, Maxime; Yueh, Jenny; Izikson, Pavel; Soco, Aileen; Wu, Jon; Nooitgedagt, Tjitte; Ottens, Jeroen; Kim, Yong Ho; Ebert, Martin

2017-03-01

On-product overlay requirements are becoming more challenging with every next technology node due to the continued decrease of the device dimensions and process tolerances. Therefore, current and future technology nodes require demanding metrology capabilities such as target designs that are robust towards process variations and high overlay measurement density (e.g. for higher order process corrections) to enable advanced process control solutions. The impact of advanced control solutions based on YieldStar overlay data is being presented in this paper. Multi patterning techniques are applied for critical layers and leading to additional overlay measurement demands. The use of 1D process steps results in the need of overlay measurements relative to more than one layer. Dealing with the increased number of overlay measurements while keeping the high measurement density and metrology accuracy at the same time presents a challenge for high volume manufacturing (HVM). These challenges are addressed by the capability to measure multi-layer targets with the recently introduced YieldStar metrology tool, YS350. On-product overlay results of such multi-layers and standard targets are presented including measurement stability performance.

Ethical issues in sports medicine: a review and justification for ethical decision making and reasoning.

PubMed

Greenfield, Bruce H; West, Charles Robert

2012-11-01

Ethical issues present a challenge for health care professionals working with athletes of sports teams. Health care professionals-including the team physician, the physical therapist, and the athletic trainer-are faced with the challenge of returning an athlete to competition as quickly as possible but as safely as possible. Conflicts of interest arise due to conflicting obligations of the team physician to the athlete and other members of the sports organization, including coaches and the team owner. The multiple stakeholders involved in sports teams challenge the traditional notion of confidentiality and autonomy. The aims of this article are to explicate the ethics of sports medicine, highlight the ethical issues, and provide some strategies and suggestions for ethical decision making.

Prevention of work disability due to musculoskeletal disorders: the challenge of implementing evidence.

PubMed

Loisel, Patrick; Buchbinder, Rachelle; Hazard, Rowland; Keller, Robert; Scheel, Inger; van Tulder, Maurits; Webster, Barbara

2005-12-01

The process of returning disabled workers to work presents numerous challenges. In spite of the growing evidence regarding work disability prevention, little uptake of this evidence has been observed. One reason for limited dissemination of evidence is the complexity of the problem, as it is subject to multiple legal, administrative, social, political, and cultural challenges. A literature review and collection of experts' opinion is presented, on the current evidence for work disability prevention, and barriers to evidence implementation. Recommendations are presented for enhancing implementation of research results. The current evidence regarding work disability prevention shows that some clinical interventions (advice to return to modified work and graded activity programs) and some non-clinical interventions (at a service and policy/community level but not at a practice level) are effective in reducing work absenteeism. Implementation of evidence in work disability is a major challenge because intervention recommendations are often imprecise and not yet practical for immediate use, many barriers exist, and many stakeholders are involved. Future studies should involve all relevant stakeholders and aim at developing new strategies that are effective, efficient, and have a potential for successful implementation. These studies should be based upon a clearer conceptualization of the broader context and inter-relationships that determine return to work outcomes.

Occupational asthma caused by samba (Triplochiton scleroxylon) wood dust in a professional maker of wooden models of airplanes: a case study.

PubMed

Krawczyk-Szulc, Patrycja; Wiszniewska, Marta; Pałczyński, Cezary; Nowakowska-Świrta, Ewa; Kozak, Anna; Walusiak-Skorupa, Jolanta

2014-06-01

Wood dust is a known occupational allergen that may induce, in exposed workers, respiratory diseases including asthma and allergic rhinitis. Samba (obeche, Triplochiton scleroxylon) is a tropical tree, which grows in West Africa, therefore, Polish workers are rarely exposed to it. This paper describes a case of occupational asthma caused by samba wood dust. The patient with suspicion of occupational asthma due to wood dust was examined at the Department of Occupational Diseases and Clinical Toxicology in the Nofer Institute of Occupational Medicine. Clinical evaluation included: analysis of occupational history, skin prick tests (SPT) to common and occupational allergens, determination of serum specific IgE to occupational allergens, serial spirometry measurements, metacholine challenge test and specific inhalation challenge test with samba dust SPT and specific serum IgE assessment revealed sensitization to common and occupational allergens including samba. Spirometry measurements showed mild obstruction. Metacholine challenge test revealed a high level of bronchial hyperactivity. Specific inhalation challenge test was positive and cellular changes in nasal lavage and induced sputum confirmed allergic reaction to samba. IgE mediated allergy to samba wood dust was confirmed. This case report presents the first documented occupational asthma and rhinitis due to samba wood dust in wooden airplanes model maker in Poland.

Recent Advances and Challenges towards Sustainable Polyhydroxyalkanoate (PHA) Production.

PubMed

Kourmentza, Constantina; Plácido, Jersson; Venetsaneas, Nikolaos; Burniol-Figols, Anna; Varrone, Cristiano; Gavala, Hariklia N; Reis, Maria A M

2017-06-11

Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing.

Two-Step Fair Scheduling of Continuous Media Streams over Error-Prone Wireless Channels

NASA Astrophysics Data System (ADS)

Oh, Soohyun; Lee, Jin Wook; Park, Taejoon; Jo, Tae-Chang

In wireless cellular networks, streaming of continuous media (with strict QoS requirements) over wireless links is challenging due to their inherent unreliability characterized by location-dependent, bursty errors. To address this challenge, we present a two-step scheduling algorithm for a base station to provide streaming of continuous media to wireless clients over the error-prone wireless links. The proposed algorithm is capable of minimizing the packet loss rate of individual clients in the presence of error bursts, by transmitting packets in the round-robin manner and also adopting a mechanism for channel prediction and swapping.

Health Performance and Challenges in Korea: a Review of the Global Burden of Disease Study 2013.

PubMed

Lee, Yo Han; Yoon, Seok Jun; Kim, Arim; Seo, Hyeyoung; Ko, Seulki

2016-11-01

The global burden of disease study (GBD) provides valuable information for evaluating population health in terms of disease burden. This study collected and reviewed GBD data in Korea for the year 1990 and 2013. The burdens of cancer, cardiovascular disease, communicable disease, and injuries have decreased remarkably, thereby greatly diminishing the overall disease burden on Korea. Meanwhile, the burdens due to non-fatal chronic diseases such as neuropsychiatric and musculoskeletal disease became major burden contributors. Responding to this circumstance presents a complex challenge to the Korean health system and Korean health policy.

Methodologies for Verification and Validation of Space Launch System (SLS) Structural Dynamic Models: Appendices

NASA Technical Reports Server (NTRS)

Coppolino, Robert N.

2018-01-01

Verification and validation (V&V) is a highly challenging undertaking for SLS structural dynamics models due to the magnitude and complexity of SLS subassemblies and subassemblies. Responses to challenges associated with V&V of Space Launch System (SLS) structural dynamics models are presented in Volume I of this paper. Four methodologies addressing specific requirements for V&V are discussed. (1) Residual Mode Augmentation (RMA). (2) Modified Guyan Reduction (MGR) and Harmonic Reduction (HR, introduced in 1976). (3) Mode Consolidation (MC). Finally, (4) Experimental Mode Verification (EMV). This document contains the appendices to Volume I.

Spermatic cord dedifferentiated liposarcoma presenting as a recurrent inguinal hernia.

PubMed

Crigger, Chad; Barnard, John; Zaslau, Stanley; Vos, Jeffrey A

2016-12-01

Paratesticular sarcomas are a rare entity and provide a unique clinical challenge due to their slow growing, often painless natural course. Adding to this challenge is the complex anatomy of the scrotum that allows these masses to mimic other conditions, including inguinal hernia, cysts, or fluid collections. We report such a case and our approach to an 83-year-old male with dedifferentiated liposarcoma of the spermatic cord with a history of inguinal hernia. In doing so, we highlight the need for thorough evaluation of scrotal masses and the management of these rare, though well-described, tumors.

Genesis, challenges and opportunities for colloidal lead halide perovskite nanocrystals

NASA Astrophysics Data System (ADS)

Akkerman, Quinten A.; Rainò, Gabriele; Kovalenko, Maksym V.; Manna, Liberato

2018-05-01

Lead halide perovskites (LHPs) in the form of nanometre-sized colloidal crystals, or nanocrystals (NCs), have attracted the attention of diverse materials scientists due to their unique optical versatility, high photoluminescence quantum yields and facile synthesis. LHP NCs have a `soft' and predominantly ionic lattice, and their optical and electronic properties are highly tolerant to structural defects and surface states. Therefore, they cannot be approached with the same experimental mindset and theoretical framework as conventional semiconductor NCs. In this Review, we discuss LHP NCs historical and current research pursuits, challenges in applications, and the related present and future mitigation strategies explored.

BNL 56 MHz HOM damper prototype fabrication at JLAB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huque, N.; McIntyre, G.; Daly, E. F.

A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider’s (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

BNL 56 MHz HOM Damper Prototype Fabrication at JLab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huque, Naeem A.; Daly, Edward F.; Clemens, William A.

A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

Health Performance and Challenges in Korea: a Review of the Global Burden of Disease Study 2013

PubMed Central

2016-01-01

The global burden of disease study (GBD) provides valuable information for evaluating population health in terms of disease burden. This study collected and reviewed GBD data in Korea for the year 1990 and 2013. The burdens of cancer, cardiovascular disease, communicable disease, and injuries have decreased remarkably, thereby greatly diminishing the overall disease burden on Korea. Meanwhile, the burdens due to non-fatal chronic diseases such as neuropsychiatric and musculoskeletal disease became major burden contributors. Responding to this circumstance presents a complex challenge to the Korean health system and Korean health policy. PMID:27775248

[Keratitis after laser in situ keratomileusis (LASIK). A different entity and treatment management].

PubMed

Ahmed, Shakil; Ahmed, Hassan Javed; Holm, Lars Morten

2014-12-15

Keratitis after laser in situ keratomileusis (LASIK) is rare and challenging as patients may present with mild symptoms and initial management differs significantly. Post-LASIK keratitis is usually due to gram-positive bacteria or opportunistic/atypical microorganisms located beneath the corneal flap. Due to relative protective interface location it is necessary to lift the corneal flap for cultures and antibiotic irrigation. The case report demonstrates that post-LASIK keratitis requires prompt referral to ophthalmology department as correct initial management is pivotal for good visual outcome.

Current status and challenges for automotive battery production technologies

NASA Astrophysics Data System (ADS)

Kwade, Arno; Haselrieder, Wolfgang; Leithoff, Ruben; Modlinger, Armin; Dietrich, Franz; Droeder, Klaus

2018-04-01

Production technology for automotive lithium-ion battery (LIB) cells and packs has improved considerably in the past five years. However, the transfer of developments in materials, cell design and processes from lab scale to production scale remains a challenge due to the large number of consecutive process steps and the significant impact of material properties, electrode compositions and cell designs on processes. This requires an in-depth understanding of the individual production processes and their interactions, and pilot-scale investigations into process parameter selection and prototype cell production. Furthermore, emerging process concepts must be developed at lab and pilot scale that reduce production costs and improve cell performance. Here, we present an introductory summary of the state-of-the-art production technologies for automotive LIBs. We then discuss the key relationships between process, quality and performance, as well as explore the impact of materials and processes on scale and cost. Finally, future developments and innovations that aim to overcome the main challenges are presented.

Multi-Relational Characterization of Dynamic Social Network Communities

NASA Astrophysics Data System (ADS)

Lin, Yu-Ru; Sundaram, Hari; Kelliher, Aisling

The emergence of the mediated social web - a distributed network of participants creating rich media content and engaging in interactive conversations through Internet-based communication technologies - has contributed to the evolution of powerful social, economic and cultural change. Online social network sites and blogs, such as Facebook, Twitter, Flickr and LiveJournal, thrive due to their fundamental sense of "community". The growth of online communities offers both opportunities and challenges for researchers and practitioners. Participation in online communities has been observed to influence people's behavior in diverse ways ranging from financial decision-making to political choices, suggesting the rich potential for diverse applications. However, although studies on the social web have been extensive, discovering communities from online social media remains challenging, due to the interdisciplinary nature of this subject. In this article, we present our recent work on characterization of communities in online social media using computational approaches grounded on the observations from social science.

Printed batteries and conductive patterns in technical textiles

NASA Astrophysics Data System (ADS)

Willert, Andreas; Meuser, Carmen; Baumann, Reinhard R.

2018-05-01

Various applications of functional devices need a tailored and reliable supply of electrical energy. Batteries are electrochemical systems that deliver energy for functional devices and applications. Due to the common use, several rigid types of batteries have been standardized. To fully integrate the battery into a product that is bendable, free in geometry and less than 1 mm thick, printing of power adaptable batteries is a challenging area of research. Therefore, the well-known zinc-manganese system, which is very promising due to its environmental sustainability and its simplicity, has been used to manufacture battery solutions on a new kind of substrate: technical textiles. Another challenge is the deposition of conductive patterns. At present, embroidery with metallic yarn is the only possibility to provide conducting paths on technical textiles, a time-consuming and elaborate process. Screen printed conductive pathways will generate a new momentum in the manufacturing of conductivity on textiles.

Be-7 as a tracer for short-term soil surface changes - opportunities and limitations

NASA Astrophysics Data System (ADS)

Baumgart, Philipp

2013-04-01

Within the last 20 years the cosmogenic nuclide Beryllium-7 was successfully established as a suitable tracer element to detect soil surface changes with a high accuracy. Particularly soil erosion rates from single precipitation events are in the focus of different studies due to the short radioactive half-life of the Be-7 isotope. High sorption at topmost soil particles and immobility at given pH-values enable fine-scaled erosion modelling down to 2 mm increments. But some important challenging limitations require particular attention, starting from sampling up to the final data evaluation. E.g. these are the realisation of the fine increment soil collection, the limiting amount of measurable samples per campaign due to the short radioactive half-life and the specific requirements for the detector measurements. Both, the high potential and the challenging limitations are presented as well as future perspectives of that tracer method.

Shuttle 'Challenger' aerodynamic performance from flight data - Comparisons with predicted values and 'Columbia' experience

NASA Technical Reports Server (NTRS)

Findlay, J. T.; Kelly, G. M.; Mcconnell, J. G.; Compton, H. R.

1984-01-01

Longitudinal aerodynamic performance comparisons between flight extracted and predicted values are presented for the first eight NASA Space Shuttle entry missions. Challenger results are correlated with the ensemble five flight Columbia experience and indicate effects due to differing angle-of-attack and body flap deflection profiles. An Appendix is attached showing the results of each flight using both the LaRC LAIRS and NOAA atmospheres. Discussions are presented which review apparent density anomalies observed in the flight data, with particular emphasis on the suggested shears and turbulence encountered during STS-2 and STS-4. Atmospheres derived from Shuttle data are presented which show structure different than that remotely sensed and imply regions of unstable air masses as a plausible explanation. Though additional aerodynamic investigations are warranted, an added benefit of Shuttle flight data for atmospheric research is discussed, in particular, as applicable to future NASA space vehicles such as AOTVs and tethered satellites.

Voice Onset Time in Consonant Cluster Errors: Can Phonetic Accommodation Differentiate Cognitive from Motor Errors?

ERIC Educational Resources Information Center

Pouplier, Marianne; Marin, Stefania; Waltl, Susanne

2014-01-01

Purpose: Phonetic accommodation in speech errors has traditionally been used to identify the processing level at which an error has occurred. Recent studies have challenged the view that noncanonical productions may solely be due to phonetic, not phonological, processing irregularities, as previously assumed. The authors of the present study…

Developing the Critical Intercultural Class-Space: Theoretical Implications and Pragmatic Applications of Critical Intercultural Communication Pedagogy

ERIC Educational Resources Information Center

Sobre, Miriam Shoshana

2017-01-01

Teaching intercultural communication presents pedagogical challenges due to the breadth and depth of the discipline and its recent critical turn. Teaching it with a social justice mission, and guiding students to understand critical and postcolonial approaches to its practice, requires complex and multifaceted approaches so as not to oppress or…

Applying Constructivist Instructional Strategies to E-Learning: A Case Study of a Web Development Course

ERIC Educational Resources Information Center

Wang, Ye Diana

2014-01-01

As the practice of e-learning continues to proliferate, online educators, especially in the computing disciplines, are facing special challenges, due to the lack of relevant literature, the technical nature of the courses, and the perceived need for direct student support mechanisms. This paper presents a constructivist instructional approach to…

Confronting challenges to economic analysis of biological invasions in forests

Treesearch

Thomas P Holmes

2010-01-01

Biological invasions of forests by non-indigenous organisms present a complex, persistent, and largely irreversible threat to forest ecosystems around the globe. Rigorous assessments of the economic impacts of introduced species, at a national scale, are needed to provide credible information to policy makers. It is proposed here that microeconomic models of damage due...

Design and Development of an Interactive Multimedia Simulation for Augmenting the Teaching and Learning of Programming Concepts

ERIC Educational Resources Information Center

Baloyi, Leonah L.; Ojo, Sunday O.; Van Wyk, Etienne A.

2017-01-01

Teaching and learning programming has presented many challenges in institutions of higher learning worldwide. Teaching and learning programming require cognitive reasoning, mainly due to the fundamental reality that the underlying concepts are complex and abstract. As a result, many institutions of higher learning are faced with low success rates…

Thrombotic thrombocytopenic purpura in a patient with sickle cell crisis.

PubMed

Bolaños-Meade, J; Keung, Y K; López-Arvizu, C; Florendo, R; Cobos, E

1999-12-01

The combination of sickle cell disease crisis and thrombotic thrombocytopenic purpura has been described only a few times. Here we present the case of a patient with a hemolytic crisis due to sickle cell disease complicated by thrombotic thrombocytopenic purpura. We also review the cases previously reported and compare and contrast them, highlighting diagnostic challenges.

Empirical Research on Native Chinese Speakers Reading in English: Data Driven Issues and Challenges

ERIC Educational Resources Information Center

Brantmeier, Cindy; Xiucheng, Yu

2014-01-01

Mastery of English in China has gathered increased prominence due to the need to foster cultural, political, and economic connections worldwide. Reading is an obvious skill of vital importance for advancing efforts as a player in the world economy. The present article examines research published in academic journals in Chinese and English to…

Development of a Tablet Application for the Screening of Receptive Vocabulary Skills in Multilingual Children: A Pilot Study

ERIC Educational Resources Information Center

Schaefer, Blanca; Bowyer-Crane, Claudine; Herrmann, Frank; Fricke, Silke

2016-01-01

For professionals working with multilingual children, detecting language deficits in a child's home language can present a challenge. This is largely due to the scarcity of standardized assessments in many children's home languages and missing normative data on multilingual language acquisition. A common approach is to translate existing English…

Student Perceptions of Asynchronous Multimodal Instructor Feedback: A Multiple Case Study

ERIC Educational Resources Information Center

Lenards, Nishele Dyan

2017-01-01

Student dissatisfaction has been a problem in higher education with regard to the provision of assessment-related feedback. Due to the distant nature of online learning, instructors are faced with many challenges in delivering quality feedback because the communication is asynchronous and lacks social cues that are present in a F2F environment.…

ADHD in Preschool: Approaches and Teacher Training

ERIC Educational Resources Information Center

Singh, Ajay; Squires, Jane

2014-01-01

Due to the prevalence of ADHD, there is a need for early intervention at the preschool level to improve children's chance of academic success in later years. Yet few preschool teachers are trained to meet the challenges children with ADHD present. This paper gives a rationale and curriculum for teacher training in ADHD, with an emphasis on Social…

Challenges of managing disease in tall orchard trees – pecan scab, a case study

USDA-ARS?s Scientific Manuscript database

Managing disease in tall orchard trees presents unique issues not found in relatively shorter horticultural and agronomic crops, simply due to height. Pecan scab (caused by Fusicladium effusum [G. Winter] Seyran et al.) is used as an example of a major disease of one of the tallest orchard crops in ...

Statistically Comparing the Performance of Multiple Automated Raters across Multiple Items

ERIC Educational Resources Information Center

Kieftenbeld, Vincent; Boyer, Michelle

2017-01-01

Automated scoring systems are typically evaluated by comparing the performance of a single automated rater item-by-item to human raters. This presents a challenge when the performance of multiple raters needs to be compared across multiple items. Rankings could depend on specifics of the ranking procedure; observed differences could be due to…

Teaching Critical Perspectives on Body Weight: The Obesity "Epidemic" and Pro-Ana Movement in Classroom Discussions

ERIC Educational Resources Information Center

Hutson, David J.

2017-01-01

While most sociology students are well prepared to think critically about inequalities involving race, gender, social class, and sexuality, the topics of body weight and health present some challenges for classroom discussion. Primarily, this is due to the body's status in contemporary society as simultaneously malleable (able to be changed) and…

Effects of Psychological Distress on Academic Achievement in Brunei Student Teachers: Identification Challenges and Counseling Implications

ERIC Educational Resources Information Center

Mundia, Lawrence

2011-01-01

Students with psychological and mental health problems are often accorded a low status and priority compared to peers with other disabilities. Recent research indicated that a female Brunei student teacher prematurely left her training program due to unaddressed mental health problems. The present study used a mixed methods approach. The random…

Social Communication Disorder outside Autism? A Diagnostic Classification Approach to Delineating Pragmatic Language Impairment, High Functioning Autism and Specific Language Impairment

ERIC Educational Resources Information Center

Gibson, Jenny; Adams, Catherine; Lockton, Elaine; Green, Jonathan

2013-01-01

Background: Developmental disorders of language and communication present considerable diagnostic challenges due to overlapping of symptomatology and uncertain aetiology. We aimed to further elucidate the behavioural and linguistic profile associated with impairments of social communication occurring outside of an autism diagnosis. Methods: Six to…

The Wonderful World of the Musical

ERIC Educational Resources Information Center

Poliniak, Susan

2010-01-01

The challenges and joys of presenting high school and middle school musicals are myriad--and, due to the many variables involved, often unlike those of choral concerts, band concerts, or just about anything else that one may encounter as a teacher. With so many moving parts, it is easy to feel overwhelmed, especially if one is new to the game. In…

Developing a Student Respite Provider System for Children with Autism

ERIC Educational Resources Information Center

Openden, Daniel; Symon, Jennifer B.; Koegel, Lynn Kern; Koegel, Robert L.

2006-01-01

Many parents of children with autism and other severe disabilities report heightened levels of stress due to the unique challenges their children present. Respite care is likely to alleviate some of the stress associated with caring for a child with a severe disability. However, it is often difficult for families to identify motivated and…

The Coming Challenge: Are Community Colleges Ready for the New Wave of Contextual Learners?

ERIC Educational Resources Information Center

Hull, Dan; Souders, John C., Jr.

1996-01-01

Defines contextual learning, or presenting new information to students in familiar contexts. Argues that community colleges must be ready for an anticipated increase in contextual learners due to its use in tech prep programs. Describes elements of contextual learning, its application in the classroom, and ways that colleges can prepare for…

Assessing the expected effects of wildfire on vegetation condition on the Bridger-Teton National Forest, Wyoming, USA

Treesearch

J. H. Scott; D. J. Helmbrecht; M. P. Thompson

2014-01-01

Characterizing wildfire risk to a fire-adapted ecosystem presents particular challenges due to its broad spatial extent, inherent complexity, and the difficulty in defining wildfire-induced losses and benefits. Our approach couples stochastic wildfire simulation with a vegetation condition assessment framework to estimate the conditional and expected response of...

Influence of Culture on Students' Awareness of How and Why They Learn

ERIC Educational Resources Information Center

Choy, Siew Chee; Sedhu, Daljeet Singh; Liew, Yow Lin; Lee, Mun Yee; Malenee, Audrey; Anuar, Norkhadirah

2015-01-01

Purpose: The reason many Asian students find student-centred learning challenging may be due to cultural factors present in every human interaction between individuals. This study attempts to determine the influence of these cultural factors on students' awareness of how and why they learn. Method: A sample of 12 students enrolled in a two year…

Beyond Social Constructionism: A Structural Analysis of the Cultural Significance of the Child Star

ERIC Educational Resources Information Center

O'Connor, Jane

2009-01-01

This article challenges the dominance of social constructionist theories of childhood by presenting a structural analysis of the child star as a recurrent, universal feature in the myths and legends of the world. The article argues that by conceptualising our understanding of children and childhood as being due solely to the socio-historical…

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

PubMed Central

Jayol, Aurélie; Nordmann, Patrice

2017-01-01

SUMMARY Polymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented. PMID:28275006

Presidential address, 1995. Surgery 2000: a look back to the future

PubMed Central

Heughan, Christopher

1996-01-01

The present demoralized state of Canadian surgery is due to a number of short-term influences. They include financial restraints, the desire of government agencies to off-load blame for unpopular decisions onto doctors and altered public expectations. The major long-term challenge will be a shortage of physicians and a severe shortage of general surgeons because of the superimposition of longer-term trends in medical demographics on short-term political reactions to a perceived oversupply of doctors. General surgeons need to identify the significant, long-term threats and challenges. If they can do this and plan their responses knowledgably, with some measure of altruism, the future in general surgery will be a bright one for present and future residents and medical students. PMID:8640616

From cerebral salt wasting to diabetes insipidus with adipsia: case report of a child with craniopharyngioma.

PubMed

Raghunathan, Veena; Dhaliwal, Maninder Singh; Gupta, Aditya; Jevalikar, Ganesh

2015-03-01

Craniopharyngioma is associated with a wide and interesting variety of sodium states both by itself and following surgical resection. These are often challenging to diagnose, especially given their dynamic nature during the perioperative course. We present the case of a boy with craniopharyngioma who had hyponatremia due to cerebral salt wasting preoperatively, developed diabetes insipidus (DI) intraoperatively and proceeded to develop hypernatremia with adipsic DI. Cerebral salt wasting is a rare presenting feature of craniopharyngioma. Postoperative DI can be associated with thirst abnormalities including adipsia due to hypothalamic damage; careful monitoring and a high index of suspicion are required for its detection. Adipsic DI is a difficult condition to manage; hence a conservative surgical approach is suggested.

Voltage-dependent cluster expansion for electrified solid-liquid interfaces: Application to the electrochemical deposition of transition metals

NASA Astrophysics Data System (ADS)

Weitzner, Stephen E.; Dabo, Ismaila

2017-11-01

The detailed atomistic modeling of electrochemically deposited metal monolayers is challenging due to the complex structure of the metal-solution interface and the critical effects of surface electrification during electrode polarization. Accurate models of interfacial electrochemical equilibria are further challenged by the need to include entropic effects to obtain accurate surface chemical potentials. We present an embedded quantum-continuum model of the interfacial environment that addresses each of these challenges and study the underpotential deposition of silver on the gold (100) surface. We leverage these results to parametrize a cluster expansion of the electrified interface and show through grand canonical Monte Carlo calculations the crucial need to account for variations in the interfacial dipole when modeling electrodeposited metals under finite-temperature electrochemical conditions.

Facial diplegia: a clinical dilemma.

PubMed

Chakrabarti, Debaprasad; Roy, Mukut; Bhattacharyya, Amrit K

2013-06-01

Bilateral facial paralysis is a rare clinical entity and presents as a diagnostic challenge. Unlike its unilateral counterpart facial diplegia is seldom secondary to Bell's palsy. Occurring at a frequency of 0.3% to 2% of all facial palsies it often indicates ominous medical conditions. Guillian-Barre syndrome needs to be considered as a differential in all given cases of facial diplegia where timely treatment would be rewarding. Here a case of bilateral facial palsy due to Guillian-Barre syndrome with atypical presentation is reported.

Critical Success Factors (CSFs) for Implementation of Enterprise Resource Planning (ERP) Systems in Various Industries, Including Institutions of Higher Education (IHEs)

ERIC Educational Resources Information Center

Debrosse-Bruno, Marie Michael

2017-01-01

Enterprise Resource Planning (ERP) systems present a management problem for various industries including institutions of higher education (IHEs) because they are costly to acquire, challenging to implement, and often fail to meet anticipated expectations. ERP systems are highly complex due to the nature of the operations they support. This…

Using a Touch-Based, Computer-Assisted Learning System to Promote Literacy and Math Skills for Low-Income Preschoolers

ERIC Educational Resources Information Center

McManis, Mark H.; McManis, Lilla Dale

2016-01-01

The use of touch-based technologies by young children to improve academic skills has seen growth outpacing empirical evidence of its effectiveness. Due to the educational challenges low-income children face, the stakes for providing instructional technology with demonstrated efficacy are high. The current work presents an empirical study of the…

A geospatial search engine for discovering multi-format geospatial data across the web

Treesearch

Christopher Bone; Alan Ager; Ken Bunzel; Lauren Tierney

2014-01-01

The volume of publically available geospatial data on the web is rapidly increasing due to advances in server-based technologies and the ease at which data can now be created. However, challenges remain with connecting individuals searching for geospatial data with servers and websites where such data exist. The objective of this paper is to present a publically...

Evaluation of methods and plating media for detection of Campylobacter in ceca from 66 different broiler flocks across 11 months

USDA-ARS?s Scientific Manuscript database

The ceca of broilers can be colonized with Campylobacter. Due to high numbers of other bacteria present, detecting Campylobacter in cecal contents can be challenging. On each of 66 sample days from April 2013 through February 2014, a single cecum was collected from the evisceration line in a comme...

New plastic recycling technology | Science Inventory | US EPA

EPA Pesticide Factsheets

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy degradation processes. This news column provides a digest of recent technical reports relating to clean technology and environmental policy,

Secure Skyline Queries on Cloud Platform.

PubMed

Liu, Jinfei; Yang, Juncheng; Xiong, Li; Pei, Jian

2017-04-01

Outsourcing data and computation to cloud server provides a cost-effective way to support large scale data storage and query processing. However, due to security and privacy concerns, sensitive data (e.g., medical records) need to be protected from the cloud server and other unauthorized users. One approach is to outsource encrypted data to the cloud server and have the cloud server perform query processing on the encrypted data only. It remains a challenging task to support various queries over encrypted data in a secure and efficient way such that the cloud server does not gain any knowledge about the data, query, and query result. In this paper, we study the problem of secure skyline queries over encrypted data. The skyline query is particularly important for multi-criteria decision making but also presents significant challenges due to its complex computations. We propose a fully secure skyline query protocol on data encrypted using semantically-secure encryption. As a key subroutine, we present a new secure dominance protocol, which can be also used as a building block for other queries. Finally, we provide both serial and parallelized implementations and empirically study the protocols in terms of efficiency and scalability under different parameter settings, verifying the feasibility of our proposed solutions.

Mode-converting coupler for silicon-on-sapphire devices

NASA Astrophysics Data System (ADS)

Zlatanovic, S.; Offord, B. W.; Owen, M.; Shimabukuro, R.; Jacobs, E. W.

2015-02-01

Silicon-on-sapphire devices are attractive for the mid-infrared optical applications up to 5 microns due to the low loss of both silicon and sapphire in this wavelength band. Designing efficient couplers for silicon-on-sapphire devices presents a challenge due to a highly confined mode in silicon and large values of refractive index of both silicon and sapphire. Here, we present design, fabrication, and measurements of a mode-converting coupler for silicon-on-sapphire waveguides. We utilize a mode converter layout that consists of a large waveguide that is overlays a silicon inverse tapered waveguide. While this geometry was previously utilized for silicon-on-oxide devices, the novelty is in using materials that are compatible with the silicon-on-sapphire platform. In the current coupler the overlaying waveguide is made of silicon nitride. Silicon nitride is the material of choice because of the large index of refraction and low absorption from near-infrared to mid-infrared. The couplers were fabricated using a 0.25 micron silicon-on-sapphire process. The measured coupling loss from tapered lensed silica fibers to the silicon was 4.8dB/coupler. We will describe some challenges in fabrication process and discuss ways to overcome them.

Digitalizing historical high resolution water level data: Challenges and opportunities

NASA Astrophysics Data System (ADS)

Holinde, Lars; Hein, Hartmut; Barjenbruch, Ulrich

2017-04-01

Historical tide-gauge data offer the opportunities for determining variations in key characteristics for water level data and the analyses of past extreme events (storm surges). These information are important for calculating future trends and scenarios. But there are challenges involved due to the extensive effort needed to digitalize gauge sheets and quality control the resulting historical data. Based on these conditions, two main sources for inaccuracies in historical time series can be identified. First are several challenges due to the digitalization of the historical data, e.g. general quality of the sheets, multiple crossing lines of the observed water levels and additional comments on the sheet describing problems or additional information during the measurements. Second are problems during the measurements themselves. These can include the incorrect positioning of the sheets, trouble with the tide-gauge and maintenance. Errors resulting from these problems can be e.g. flat lines, discontinuities and outlier. Especially, the characterization of outliers has to be conducted carefully, to distinguish between real outliers and the appearance of extreme events. Methods for the quality control process involve the use of statistics, machine learning and neural networks. These will be described and applied to three different time series from tide gauge stations at the cost of Lower Saxony, Germany. Resulting difficulties and outcomes of the quality control process will be presented and explained. Furthermore, we will present a first glance at analyses for these time series.

Enhanced Communication Network Solution for Positive Train Control Implementation

NASA Technical Reports Server (NTRS)

Fatehi, M. T.; Simon, J.; Chang, W.; Chow, E. T.; Burleigh, S. C.

2011-01-01

The commuter and freight railroad industry is required to implement Positive Train Control (PTC) by 2015 (2012 for Metrolink), a challenging network communications problem. This paper will discuss present technologies developed by the National Aeronautics and Space Administration (NASA) to overcome comparable communication challenges encountered in deep space mission operations. PTC will be based on a new cellular wireless packet Internet Protocol (IP) network. However, ensuring reliability in such a network is difficult due to the "dead zones" and transient disruptions we commonly experience when we lose calls in commercial cellular networks. These disruptions make it difficult to meet PTC s stringent reliability (99.999%) and safety requirements, deployment deadlines, and budget. This paper proposes innovative solutions based on space-proven technologies that would help meet these challenges: (1) Delay Tolerant Networking (DTN) technology, designed for use in resource-constrained, embedded systems and currently in use on the International Space Station, enables reliable communication over networks in which timely data acknowledgments might not be possible due to transient link outages. (2) Policy-Based Management (PBM) provides dynamic management capabilities, allowing vital data to be exchanged selectively (with priority) by utilizing alternative communication resources. The resulting network may help railroads implement PTC faster, cheaper, and more reliably.

Emerging Point-of-Care Technologies for Sickle Cell Disease Screening and Monitoring

PubMed Central

Alapan, Yunus; Fraiwan, Arwa; Kucukal, Erdem; Hasan, M. Noman; Ung, Ryan; Kim, Myeongseop; Odame, Isaac; Little, Jane A.; Gurkan, Umut A.

2016-01-01

Introduction Sickle Cell Disease (SCD) affects 100,000 Americans and more than 14 million people globally, mostly in economically disadvantaged populations, requires early diagnosis after birth and constant monitoring throughout the life-span of the patient. Areas Covered Early diagnosis of SCD still remains a challenge in preventing childhood mortality in the developing world due to requirements of skilled personnel and high-cost of currently available modalities. On the other hand, SCD monitoring presents insurmountable challenges due to heterogeneities among patient populations, as well as in the same individual longitudinally. Here, we describe emerging point-of-care micro/nano platform technologies for SCD screening and monitoring, and critically discuss current state-of-the-art, potential challenges associated with these technologies, and future directions. Expert Commentary Recently developed microtechnologies offer simple, rapid, and affordable screening of SCD and have the potential to facilitate universal screening in resource-limited settings and developing countries. On the other hand, monitoring of SCD is more complicated compared to diagnosis and requires comprehensive validation of efficacy. Early use of novel microdevices for patient monitoring might come in especially handy in new clinical trial designs of emerging therapies. PMID:27785945

Direct Numerical Simulations of Concentration and Temperature Polarization in Direct Contact Membrane Distillation

NASA Astrophysics Data System (ADS)

Lou, Jincheng; Tilton, Nils

2017-11-01

Membrane distillation (MD) is a method of desalination with boundary layers that are challenging to simulate. MD is a thermal process in which warm feed and cool distilled water flow on opposite sides of a hydrophobic membrane. The temperature difference causes water to evaporate from the feed, travel through the membrane, and condense in the distillate. Two challenges to MD are temperature and concentration polarization. Temperature polarization represents a reduction in the transmembrane temperature difference due to heat transfer through the membrane. Concentration polarization describes the accumulation of solutes near the membrane. These phenomena reduce filtration and lead to membrane fouling. They are difficult to simulate due to the coupling between the velocity, temperature, and concentration fields on the membrane. Unsteady regimes are particularly challenging because noise at the outlets can pollute the near-membrane flow fields. We present the development of a finite-volume method for the simulation of fluid flow, heat, and mass transport in MD systems. Using the method, we perform a parametric study of the polarization boundary layers, and show that the concentration boundary layer shows self-similar behavior that satisfies power laws for the downstream growth. Funded by the U.S. Bureau of Reclamation.

Multi-Drug-Resistant Klebsiella pneumoniae Pancreatitis: A New Challenge in a Serious Surgical Infection

PubMed Central

Tugal, Derin; Lynch, Melanie; Hujer, Andrea M.; Rudin, Susan; Perez, Federico

2015-01-01

Abstract Background: Klebsiella pneumoniae is an important cause of nosocomial infections, but its role in severe acute pancreatitis (SAP) is not well defined. Few cases of K. pneumoniae associated SAP have been reported. Due to the emergence of extended-spectrum beta-lactamases (ESBLs) and carbapenemases, treatment of multidrug-resistant (MDR) K. pneumoniae presents a challenge. Tigecycline and colistin have gained recent attention for their broad-spectrum antimicrobial activity. Methods: We describe a case of SAP due to K. pneumoniae bearing K. pneumoniae carbapenemase (KPC) treated successfully with colistin plus tigecycline and offer a review of similar experiences published in the literature. Results: The case reported herein required surgical drainage of multiple pancreatic abscesses and treatment with tigecycline and colistin. Our comparative analysis revealed a number of unique features associated with SAP due to K. pneumoniae: 1) underlying pancreatic injury, 2) multiple drug resistance determinants and virulence factors that complicate treatment, and 3) surgical debridement as a requirement for cure. Conclusion: As the prevalence of K. pneumoniae bearing KPC continues to increase in the healthcare setting, SAP caused by this MDR pathogen will become more common. Tigecycline plus colistin was a successful antibiotic regimen for the treatment of SAP due to K. pneumoniae bearing KPC. PMID:24850293

Nanotechnology: Opportunities and Challenges

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya

2003-01-01

Nanotechnology seeks to exploit novel physical, chemical, biological, mechanical, electrical, and other properties, which arise primarily due to the nanoscale nature of certain materials. A key example is carbon nanotubes (CNTs) which exhibit unique electrical and extraordinary mechanical properties and offer remarkable potential for revolutionary applications in electronics devices, computing, and data storage technology, sensors, composites, nanoelectromechanical systems (NEMS), and as tip in scanning probe microscopy (SPM) for imaging and nanolithography. Thus the CNT synthesis, characterization, and applications touch upon all disciplines of science and engineering. This presentation will provide an overview and progress report on this and other major research candidates in Nanotechnology and address opportunities and challenges ahead.

Recent Advances and Challenges towards Sustainable Polyhydroxyalkanoate (PHA) Production

PubMed Central

Kourmentza, Constantina; Plácido, Jersson; Venetsaneas, Nikolaos; Burniol-Figols, Anna; Varrone, Cristiano; Gavala, Hariklia N.; Reis, Maria A. M.

2017-01-01

Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing. PMID:28952534

Wind Power: A Renewable Energy Source for Mars Transit Vehicle

NASA Technical Reports Server (NTRS)

Flynn, Michael; Kohout, Lisa; Kliss, Mark (Technical Monitor)

1998-01-01

The Martian environment presents significant design challenges for the development of power generation systems. Nuclear-based systems may not be available due to political and safety concerns. The output of photovoltaics are limited by a solar intensity of 580 W/sqm as compared to 1353 W/sqm on Earth. The presence of dust particles in the Mars atmosphere will further reduce the photovoltaic output. Also, energy storage for a 12-hour night period must be provided. In this challenging environment, wind power generation capabilities may provide a viable option as a Martian power generation system. This paper provides an analysis of the feasibility of such a system.

System requirements for head down and helmet mounted displays in the military avionics environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flynn, M.F.; Kalmanash, M.; Sethna, V.

1996-12-31

The introduction of flat panel display technologies into the military avionics cockpit is a challenging proposition, due to the very difficult system level requirements which must be met. These relate to environmental extremes (temperature and vibrational), sever ambient lighting conditions (10,000 fL to nighttime viewing), night vision system compatibility, and wide viewing angle. At the same time, the display system must be packaged in minimal space and use minimal power. The authors will present details on the display system requirements for both head down and helmet mounted systems, as well as information on how these challenges may be overcome.

Role of bilateral inferior petrosal sinus sampling (BIPSS) in the diagnosis of Cushing’s disease in a patient with double superior vena cava

PubMed Central

Tashi, Sonam; Ng, Keng Sin

2015-01-01

Cushing’s syndrome is known to have a wide spectrum of clinical presentation with debilitating consequences and morbidity if not diagnosed and treated in time. Sometimes the diagnosis of Cushing’s syndrome can be challenging to the endocrinologist, especially when the usual battery of biochemical tests and advanced cross-sectional imaging is negative or inconclusive. We described a case in which the use of bilateral inferior petrosal sinus sampling (BIPSS) was conclusive albeit being technically challenging (due to a rare incidental finding of double superior vena cava) and invasive in nature. PMID:26629301

The role of hyperthermia and metabolism as mechanisms of tolerance to methamphetamine neurotoxicity.

PubMed

Johnson-Davis, Kamisha L; Fleckenstein, Annette E; Wilkins, Diana G

2003-12-15

Pretreatment with multiple methamphetamine injections prior to a high-dose methamphetamine challenge administration can attenuate long-term deficits in striatal and hippocampal serotonin content caused by the stimulant. The present data extend previous findings by demonstrating that rats pretreated with escalating doses methamphetamine did not exhibit dopamine deficits in the striatum, nor serotonin deficits in striatal, frontal cortical, or hippocampal tissues, 7 days after a challenge methamphetamine administration. This protection was not due to attenuation of methamphetamine-induced hyperthermia or altered brain methamphetamine concentrations. These data differ from previous findings thereby highlighting that different mechanisms contribute to the tolerance of the neurotoxic effects.

India's Computational Biology Growth and Challenges.

PubMed

Chakraborty, Chiranjib; Bandyopadhyay, Sanghamitra; Agoramoorthy, Govindasamy

2016-09-01

India's computational science is growing swiftly due to the outburst of internet and information technology services. The bioinformatics sector of India has been transforming rapidly by creating a competitive position in global bioinformatics market. Bioinformatics is widely used across India to address a wide range of biological issues. Recently, computational researchers and biologists are collaborating in projects such as database development, sequence analysis, genomic prospects and algorithm generations. In this paper, we have presented the Indian computational biology scenario highlighting bioinformatics-related educational activities, manpower development, internet boom, service industry, research activities, conferences and trainings undertaken by the corporate and government sectors. Nonetheless, this new field of science faces lots of challenges.

Treating Heart Failure with Preserved Ejection Fraction: A Challenge for Clinicians.

PubMed

Howard, Patricia A

2015-06-01

Despite a decline in many forms of cardiovascular disease, heart failure (HF) continues to increase. Heart failure with preserved ejection fraction (HFpEF) is common, especially among persons with multiple comorbidities. HFpEF presents many challenges for clinicians due to the incomplete understanding of the underlying mechanisms and lack of consensus on the most effective strategies for treatment. Angiotensin and beta receptor-blocking drugs, which form the cornerstone for the treatment of systolic HF, have failed to show similar benefits in patients with impaired diastolic function. This article provides an overview of drug therapy for HFpEF, including newer agents now under investigation.

Vaginal microbicides and teenagers.

PubMed

Rupp, Richard E; Rosenthal, Susan L

2003-10-01

Sexually active teens are at significant risk from sexually transmitted infections and girls and women bear the greatest burden of these infections. New methods, such as vaginal microbicides, would provide female controlled options. Microbicides are currently in development and thus it is timely to discuss the progress made and factors that may influence acceptability for teens. Microbicide development presents many challenges, and several different potential mechanisms of action are being explored. There is interest in these products from women and men, and specific preferences are being investigated. Adolescents, due to reproductive system immaturity, developing cognitive abilities and the psychosocial context of their relationships, present a special set of challenges in efforts to foster microbicide use. Vaginal microbicides are on the horizon. Further study into teen issues is required to develop successful strategies for marketing and encouraging adolescent use of microbicides.

Aspergillus spondylodiscitis after multivisceral transplantation.

PubMed

Gerlach, Undine A; Kohler, Sven; Sauer, Igor M; Joerres, Dinah; Kandziora, Frank; Neuhaus, Peter; Pratschke, Johann; Pascher, Andreas

2009-01-01

Although spondylodiscitis is rare, it is increasingly described in patients with compromised immunity due to malignancy, chemotherapy or immunosuppression. Typical pathogens are staphylococcus aureus and enterobacteria; fungal spondylodiscitis is uncommon. We present a case of aspergillus spondylodiscitis following pulmonary aspergillosis in a patient with multivisceral and kidney transplantation. Due to irreversible disc destruction, surgical restoration by autologous iliac crest graft was required in addition to intravenous antifungal therapy, which consisted of voriconazole, caspofungin and liposomal amphotericin B. Aspergillus spondylodiscitis is a diagnostic and therapeutic challenge, a combination of surgical debridement and antifungal therapy is inevitable to prevent rapid progression of invasive aspergillosis and neurological damage.

Spinal cord grey matter segmentation challenge.

PubMed

Prados, Ferran; Ashburner, John; Blaiotta, Claudia; Brosch, Tom; Carballido-Gamio, Julio; Cardoso, Manuel Jorge; Conrad, Benjamin N; Datta, Esha; Dávid, Gergely; Leener, Benjamin De; Dupont, Sara M; Freund, Patrick; Wheeler-Kingshott, Claudia A M Gandini; Grussu, Francesco; Henry, Roland; Landman, Bennett A; Ljungberg, Emil; Lyttle, Bailey; Ourselin, Sebastien; Papinutto, Nico; Saporito, Salvatore; Schlaeger, Regina; Smith, Seth A; Summers, Paul; Tam, Roger; Yiannakas, Marios C; Zhu, Alyssa; Cohen-Adad, Julien

2017-05-15

An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Chyle fistula in advanced and metastatic thyroid cancer.

PubMed

Duque, Carlos S; Sánchez, Juan Guillermo; Dionigi, Gianlorenzo

2017-10-01

Chyle fistula (CF) is a rare but challenging condition for the surgeon and the patient's health. A retrospective review of single surgeon's case load in a 12-year period is presented, reviewing the case of those patients presenting with a CF. Three patients were found during this study period from more than 1,050 surgeries performed due to thyroid cancer. Patients underwent extensive lymph node dissection for advanced, metastatic and infiltrative disease. In all patients, a long hospital stay and surgical re-interventions were required. A description of the management of CF is presented along with a review of current Literature.

Risk Considerations of Bird Strikes to Space Launch Vehicles

NASA Technical Reports Server (NTRS)

Hales, Christy; Ring, Robert

2016-01-01

Within seconds after liftoff of the Space Shuttle during mission STS-114, a turkey vulture impacted the vehicle's external tank. The contact caused no apparent damage to the Shuttle, but the incident led NASA to consider the potential consequences of bird strikes during a Shuttle launch. The environment at Kennedy Space Center provides unique bird strike challenges due to the Merritt Island National Wildlife Refuge and the Atlantic Flyway bird migration routes. NASA is currently refining risk assessment estimates for the probability of bird strike to space launch vehicles. This paper presents an approach for analyzing the risks of bird strikes to space launch vehicles and presents an example. The migration routes, types of birds present, altitudes of those birds, exposed area of the launch vehicle, and its capability to withstand impacts affect the risk due to bird strike. A summary of significant risk contributors is discussed.

A comprehensive review on droplet-based bioprinting: Past, present and future.

PubMed

Gudapati, Hemanth; Dey, Madhuri; Ozbolat, Ibrahim

2016-09-01

Droplet-based bioprinting (DBB) offers greater advantages due to its simplicity and agility with precise control on deposition of biologics including cells, growth factors, genes, drugs and biomaterials, and has been a prominent technology in the bioprinting community. Due to its immense versatility, DBB technology has been adopted by various application areas, including but not limited to, tissue engineering and regenerative medicine, transplantation and clinics, pharmaceutics and high-throughput screening, and cancer research. Despite the great benefits, the technology currently faces several challenges such as a narrow range of available bioink materials, bioprinting-induced cell damage at substantial levels, limited mechanical and structural integrity of bioprinted constructs, and restrictions on the size of constructs due to lack of vascularization and porosity. This paper presents a first-time review of DBB and comprehensively covers the existing DBB modalities including inkjet, electrohydrodynamic, acoustic, and micro-valve bioprinting. The recent notable studies are highlighted, the relevant bioink biomaterials and bioprinters are expounded, the application areas are presented, and the future prospects are provided to the reader. Copyright © 2016 Elsevier Ltd. All rights reserved.

Participant selection for preventive Regenerative Medicine trials: ethical challenges of selecting individuals at risk.

PubMed

Niemansburg, Sophie L; Habets, Michelle G J L; Dhert, Wouter J A; van Delden, Johannes J M; Bredenoord, Annelien L

2015-11-01

The innovative field of Regenerative Medicine (RM) is expected to extend the possibilities of prevention or early treatment in healthcare. Increasingly, clinical trials will be developed for people at risk of disease to investigate these RM interventions. These individuals at risk are characterised by their susceptibility for developing clinically manifest disease in future due to the existence of degenerative abnormalities. So far, there has been little debate about the ethical appropriateness of including such individuals at risk in clinical trials. We discuss three main challenges of selecting this participant model for testing RM interventions: the challenge of achieving a proportional risk-benefit balance; complexities in the trial design in terms of follow-up and sample size; and the difficulty of obtaining informed consent due to the many uncertainties. We conclude that selecting the model is not ethically justifiable for first-in-man trials with RM interventions due to the high risks and uncertainties. However, the model can be ethically appropriate for testing the efficacy of RM interventions under the following conditions: interventions should be low risk; the degenerative abnormalities (and other risk factors) should be strongly related with disease within a short time frame; robust preclinical evidence of efficacy needs to be present; and the informed consent procedure should contain extra safeguards with regard to communication on uncertainties. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Development of Vaccines to Prevent Wound Infections Due to Anerobic Bacteria

DTIC Science & Technology

1981-09-01

lot variability of the monosaccharide constituents 4 IV. Safety and toxicity testing of Lot 1 of polysaccharide antigens from B. fragilis strains 9343...the polysaccharide into monosac- charides followed by conversion of these to alditol acetates demonstrates several interesting monosaccharides present...rats with the capsular polysaccharide of B. fragilis iniuces protection to subsequent challenge with this organism. We have prpviously shown that in

Climate change in the age of humans

Treesearch

J. Curt Stager

2014-01-01

The Anthropocene epoch presents a mix of old and new challenges for the world’s forests. Climatic instability has typified most of the Cenozoic Era but today’s situation is unique due to the presence of billions of humans on the planet. The potential rate and magnitude of future warming driven by continued fossil fuel combustion could be unprecedented during the last...

Photovoltaic Cell Operation on Mars

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Kerslake, Thomas; Jenkins, Phillip P.; Scheiman, David A.

2004-01-01

The Martian surface environment provides peculiar challenges for the operation of solar arrays: low temperature, solar flux with a significant scattered component that varies in intensity and spectrum with the amount of suspended atmospheric dust, and the possibility of performance loss due to dust deposition on the array surface. This paper presents theoretical analyses of solar cell performance on the surface of Mars and measurements of cells under Martian conditions.

Wafer-shape metrics based foundry lithography

NASA Astrophysics Data System (ADS)

Kim, Sungtae; Liang, Frida; Mileham, Jeffrey; Tsai, Damon; Bouche, Eric; Lee, Sean; Huang, Albert; Hua, C. F.; Wei, Ming Sheng

2017-03-01

As device shrink, there are many difficulties with process integration and device yield. Lithography process control is expected to be a major challenge due to tighter overlay and focus control requirement. The understanding and control of stresses accumulated during device fabrication has becoming more critical at advanced technology nodes. Within-wafer stress variations cause local wafer distortions which in turn present challenges for managing overlay and depth of focus during lithography. A novel technique for measuring distortion is Coherent Gradient Sensing (CGS) interferometry, which is capable of generating a high-density distortion data set of the full wafer within a time frame suitable for a high volume manufacturing (HVM) environment. In this paper, we describe the adoption of CGS (Coherent Gradient Sensing) interferometry into high volume foundry manufacturing to overcome these challenges. Leveraging this high density 3D metrology, we characterized its In-plane distortion as well as its topography capabilities applied to the full flow of an advanced foundry manufacturing. Case studies are presented that summarize the use of CGS data to reveal correlations between in-plane distortion and overlay variation as well as between topography and device yield.

Effects of route and time of administration of antiserum on protection of mice from lethal infection due to group B Streptococcus type III.

PubMed Central

Stanton, B F; Baltimore, R S; Shedd, D G

1981-01-01

The present study examines a mouse model of infection due to group B Streptococcus serotype III (GBS-III) as to the route and timing of antiserum administration for protection and quantitation of bacteremia with and without antiserum. Data for these parameters are contrasted with those after challenge with serotype Ia of group B Streptococcus (GBS-Ia). An intraperitoneal injection of GBS organisms and protective antiserum from a single syringe can be used to create an animal model of disease. Intraperitoneal injection of GBS-III resulted in bacteremia at 0.5 h both in animals who did not receive antiserum (17.4 X 10(2) +/- 7.6 X 10(2) colony-forming units per ml of blood samples) and in animals who received antiserum (19.3 X 10(1) +/- 6.8 X 10(1) colony-forming units per ml). Although intraperitoneal injection of GBS-Ia also resulted in bacteremia evident by 0.5 h in unprotected animals (30.1 X 10(2) +/- 3.8 X 10(2) colony-forming units per ml), no bacteremia occurred in protected recipients of this organism. Bacteremia due to GBS-Ia and GBS-III logarithmically increased until at least 7 h. Bacteremia due to GBS-III in protected animals was cleared by 24 h. Protection against GBS disease did not require simultaneous or proximate administration of the organism and the antiserum. Mice could be protected from death after intraperitoneal challenge with GBS-III or GBS-Ia by antiserum administered intravenously or intraperitoneally from 6 h before to 2.5 h after challenge. PMID:7011999

Modernization of the Cassini Ground System

NASA Technical Reports Server (NTRS)

Razo, Gus; Fujii, Tammy J.

2014-01-01

The Cassini Spacecraft and its ground system have been operational for over 16 years. Modernization presents several challenges due to the personnel, processes, and tools already invested and embedded into the current ground system structure. Every mission's ground system has its own unique complexities and challenges, involving various organizational units. As any mission from its inception to its execution, schedules are always tight. This forces GDS engineers to implement a working ground system that is not necessarily fully optimized. Ground system challenges increase as technology evolves and cyber threats become more sophisticated. Cassini's main challenges were due to its ground system existing before many security requirements were levied on the multi-mission tools and networks. This caused a domino effect on Cassini GDS tools that relied on outdated technological features. In the aerospace industry reliable and established technology is preferred over innovative yet less proven technology. Loss of data for a spacecraft mission can be catastrophic; therefore, there is a reluctance to make changes and updates to the ground system. Nevertheless, all missions and associated teams face the need to modernize their processes and tools. Systems development methods from well-known system analysis and design principles can be applied to many missions' ground systems. Modernization should always be considered, but should be done in such a way that it does not affect flexibility nor interfere with established practices. Cassini has accomplished a secure and efficient ground data system through periodic updates. The obstacles faced while performing the modernization of the Cassini ground system will be outlined, as well as the advantages and challenges that were encountered.

Transboundary fisheries science: Meeting the challenges of inland fisheries management in the 21st century

USGS Publications Warehouse

Midway, Stephen R.; Wagner, Tyler; Zydlewski, Joseph D.; Irwin, Brian J.; Paukert, Craig P.

2016-01-01

Managing inland fisheries in the 21st century presents several obstacles, including the need to view fisheries from multiple spatial and temporal scales, which usually involves populations and resources spanning sociopolitical boundaries. Though collaboration is not new to fisheries science, inland aquatic systems have historically been managed at local scales and present different challenges than in marine or large freshwater systems like the Laurentian Great Lakes. Therefore, we outline a flexible strategy that highlights organization, cooperation, analytics, and implementation as building blocks toward effectively addressing transboundary fisheries issues. Additionally, we discuss the use of Bayesian hierarchical models (within the analytical stage), due to their flexibility in dealing with the variability present in data from multiple scales. With growing recognition of both ecological drivers that span spatial and temporal scales and the subsequent need for collaboration to effectively manage heterogeneous resources, we expect implementation of transboundary approaches to become increasingly critical for effective inland fisheries management.

A New Observation of an Atypical and Severe Variant of the Guillain-Barre Syndrome in a Child

PubMed Central

Manel, Véronique; Ville, Dorothée; Javouhey, Etienne; Bordet, Fabienne

2015-01-01

Guillain-Barré syndrome is a rare acute polyradiculoneuropathy. Several variants and unusual presentations have been described, particularly in pediatrics. In most cases, making an early diagnosis is challenging due to the treatments that consist in the rapid administration of intravenous immunoglobulin or plasma exchange. The authors present the case of a 7-year-old boy with an atypical and severe axonal Guillain-Barré syndrome, associated with Mycoplasma pneumonia. When he was admitted, febrile respiratory failure was the main focus, and then he presented signs of acute polyneuropathy with cranial nerve palsy and brief hyperreflexia. Mechanical ventilation was required for 48 days as well as 2 cycles of intravenous immunoglobulin. The authors describe all the medical challenges that the authors encountered. This case highlights the fact that respiratory distress can be the main clinical symptom in children. This delays the establishment of a correct diagnosis, even more so when neurological manifestations are abundant and unusual. PMID:28503595

Detection of calcium phosphate crystals in the joint fluid of patients with osteoarthritis – analytical approaches and challenges

PubMed Central

Yavorskyy, Alexander; Hernandez-Santana, Aaron; McCarthy, Geraldine

2008-01-01

Clinically, osteoarthritis (OA) is characterised by joint pain, stiffness after immobility, limitation of movement and, in many cases, the presence of basic calcium phosphate (BCP) crystals in the joint fluid. The detection of BCP crystals in the synovial fluid of patients with OA is fraught with challenges due to the submicroscopic size of BCP, the complex nature of the matrix in which they are found and the fact that other crystals can co-exist with them in cases of mixed pathology. Routine analysis of joint crystals still relies almost exclusively on the use of optical microscopy, which has limited applicability for BCP crystal identification due to limited resolution and the inherent subjectivity of the technique. The purpose of this Critical Review is to present an overview of some of the main analytical tools employed in the detection of BCP to date and the potential of emerging technologies such as atomic force microscopy (AFM) and Raman microspectroscopy for this purpose. PMID:18299743

Enhancement of microalgal growth and biocomponent-based transformations for improved biofuel recovery: A review.

PubMed

Salama, El-Sayed; Hwang, Jae-Hoon; El-Dalatony, Marwa M; Kurade, Mayur B; Kabra, Akhil N; Abou-Shanab, Reda A I; Kim, Ki-Hyun; Yang, Il-Seung; Govindwar, Sanjay P; Kim, Sunjoon; Jeon, Byong-Hun

2018-06-01

Microalgal biomass has received much attention as feedstock for biofuel production due to its capacity to accumulate a substantial amount of biocomponents (including lipid, carbohydrate, and protein), high growth rate, and environmental benefit. However, commercial realization of microalgal biofuel is a challenge due to its low biomass production and insufficient technology for complete utilization of biomass. Recently, advanced strategies have been explored to overcome the challenges of conventional approaches and to achieve maximum possible outcomes in terms of growth. These strategies include a combination of stress factors; co-culturing with other microorganisms; and addition of salts, flue gases, and phytohormones. This review summarizes the recent progress in the application of single and combined abiotic stress conditions to stimulate microalgal growth and its biocomponents. An innovative schematic model is presented of the biomass-energy conversion pathway that proposes the transformation of all potential biocomponents of microalgae into biofuels. Copyright © 2018 Elsevier Ltd. All rights reserved.

Eosinophilic airway disease in a patient with a negative skin prick test, but a positive patch test with platinum salts--implications for medical surveillance.

PubMed

Merget, Rolf; Fartasch, Manigé; Sander, Ingrid; Van Kampen, Vera; Raulf, Monika; Brüning, Thomas

2015-09-01

We present the case of a 52-year-old woman with a topic dermatitis since adolescence who developed work-related hand eczema, cough and runny nose 12 years after she had started working as a laboratory technician at a precious metals refinery. While skin prick test with sodium hexachloroplatinate (SPTPt ) was negative, patch testing with ammonium tetrachloroplatinate was positive after 24, 48, 72, and 96 hr. Inhalation challenge with sodium hexachloroplatinate yielded cough, mild shortness of breath, and a maximal decrease of FEV1 of 8% from baseline 24 hr after the challenge. Significant increases of bronchial hyperresponsiveness, exhaled nitric monoxide and sputum eosinophils were documented after the challenge. We conclude that eosinophilic airway disease due to platinum salts may occur in SPTPt negative subjects. Both, patch testing and inhalation challenge with platinum salts should be considered in SPT negative subjects with occupational exposure to precious metal salts and work-related allergic symptoms. © 2015 Wiley Periodicals, Inc.

Stem cell technology for tendon regeneration: current status, challenges, and future research directions

PubMed Central

Lui, Pauline Po Yee

2015-01-01

Tendon injuries are a common cause of physical disability. They present a clinical challenge to orthopedic surgeons because injured tendons respond poorly to current treatments without tissue regeneration and the time required for rehabilitation is long. New treatment options are required. Stem cell-based therapies offer great potential to promote tendon regeneration due to their high proliferative, synthetic, and immunomodulatory activities as well as their potential to differentiate to the target cell types and undergo genetic modification. In this review, I first recapped the challenges of tendon repair by reviewing the anatomy of tendon. Next, I discussed the advantages and limitations of using different types of stem cells compared to terminally differentiated cells for tendon tissue engineering. The safety and efficacy of application of stem cells and their modified counterparts for tendon tissue engineering were then summarized after a systematic literature search in PubMed. The challenges and future research directions to enhance, optimize, and standardize stem cell-based therapies for augmenting tendon repair were then discussed. PMID:26715856

Approach to and Treatment of Thyroid Disorders in the Elderly

PubMed Central

Papaleontiou, Maria

2012-01-01

Synopsis Thyroid gland dysfunction is prevalent in older adults and may be associated with significant morbidity if misdiagnosed and left untreated. Due to a decreased number of symptoms at presentation, an increased susceptibility to adverse events if not treated, and a greater likelihood of harm from treatment, the diagnosis and management of thyroid disorders in older adults can be challenging. This review focuses on the epidemiology, clinical presentation, risks/complications, and management of thyroid disorders (including hyperthyroidism, hypothyroidism, thyroid nodules and thyroid cancer) in older adults. PMID:22443977

Management of Gout and Hyperuricemia in CKD.

PubMed

Vargas-Santos, Ana Beatriz; Neogi, Tuhina

2017-09-01

Hyperuricemia and gout, the clinical manifestation of monosodium urate crystal deposition, are common in patients with chronic kidney disease (CKD). Although the presence of CKD poses additional challenges in gout management, effective urate lowering is possible for most patients with CKD. Initial doses of urate-lowering therapy are lower than in the non-CKD population, whereas incremental dose escalation is guided by regular monitoring of serum urate levels to reach the target level of <6mg/dL (or <5mg/dL for patients with tophi). Management of gout flares with presently available agents can be more challenging due to potential nephrotoxicity and/or contraindications in the setting of other common comorbid conditions. At present, asymptomatic hyperuricemia is not an indication for urate-lowering therapy, though emerging data may support a potential renoprotective effect. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Silver Nanoparticles: Technological Advances, Societal Impacts, and Metrological Challenges

PubMed Central

Calderón-Jiménez, Bryan; Johnson, Monique E.; Montoro Bustos, Antonio R.; Murphy, Karen E.; Winchester, Michael R.; Vega Baudrit, José R.

2017-01-01

Silver nanoparticles (AgNPs) show different physical and chemical properties compared to their macroscale analogs. This is primarily due to their small size and, consequently, the exceptional surface area of these materials. Presently, advances in the synthesis, stabilization, and production of AgNPs have fostered a new generation of commercial products and intensified scientific investigation within the nanotechnology field. The use of AgNPs in commercial products is increasing and impacts on the environment and human health are largely unknown. This article discusses advances in AgNP production and presents an overview of the commercial, societal, and environmental impacts of this emerging nanoparticle (NP), and nanomaterials in general. Finally, we examine the challenges associated with AgNP characterization, discuss the importance of the development of NP reference materials (RMs) and explore their role as a metrological mechanism to improve the quality and comparability of NP measurements. PMID:28271059

Silver nanoparticles: technological advances, societal impacts, and metrological challenges

NASA Astrophysics Data System (ADS)

Calderón-Jiménez, Bryan; Johnson, Monique E.; Montoro Bustos, Antonio R.; Murphy, Karen E.; Winchester, Michael R.; Vega Baudrit, José R.

2017-02-01

Silver nanoparticles (AgNPs) show different physical and chemical properties compared to their macroscale analogs. This is primarily due to their small size and, consequently, the exceptional surface area of these materials. Presently, advances in the synthesis, stabilization, and production of AgNPs have fostered a new generation of commercial products and intensified scientific investigation within the nanotechnology field. The use of AgNPs in commercial products is increasing and impacts on the environment and human health are largely unknown. This article discusses advances in AgNP production and presents an overview of the commercial, societal, and environmental impacts of this emerging nanoparticle (NP), and nanomaterials in general. Finally, we examine the challenges associated with AgNP characterization, discuss the importance of the development of NP reference materials (RMs) and explore their role as a metrological mechanism to improve the quality and comparability of NP measurements.

Design of a rear anamorphic attachment for digital cinematography

NASA Astrophysics Data System (ADS)

Cifuentes, A.; Valles, A.

2008-09-01

Digital taking systems for HDTV and now for the film industry present a particularly challenging design problem for rear adapters in general. The thick 3-channel prism block in the camera provides an important challenge in the design. In this paper the design of a 1.33x rear anamorphic attachment is presented. The new design departs significantly from the traditional Bravais condition due to the thick dichroic prism block. Design strategies for non-rotationally symmetric systems and fields of view are discussed. Anamorphic images intrinsically have a lower contrast and less resolution than their rotationally symmetric counterparts, therefore proper image evaluation must be considered. The interpretation of the traditional image quality methods applied to anamorphic images is also discussed in relation to the design process. The final design has a total track less than 50 mm, maintaining the telecentricity of the digital prime lens and taking full advantage of the f/1.4 prism block.

Spectral signatures for RDX-based explosives in the 3 micron region

NASA Astrophysics Data System (ADS)

Osborn, Tabetha; Kaimal, Sindhu; Reeve, Scott W.; Burns, William

2008-04-01

Explosive compounds such as RDX, and HMX present significant challenges to optically based sensors. This difficulty is due in part to the low vapor pressures these compounds possess. One approach for sensing explosives that circumvents the low explosive vapor pressure problem, involves focusing on the trace amounts of relatively high vapor pressure impurities that will be present in the vapor signature. In order to effectively detect these volatile impurities, the spectral signature databases must be readily available. One of our goals therefore, is the generation of a database of high resolution spectral signatures for these volatile organic impurities. Some rather formidable spectroscopic measurement challenges have been encountered while working to extend the spectral signature effort to the 3 micron region. Here we will outline progress to date, with a focus on the volatile organic compounds formaldehyde, acetaldehyde, nitromethane, acetone, isobutene, and cyclohexanone.

Silver Nanoparticles: Technological Advances, Societal Impacts, and Metrological Challenges.

PubMed

Calderón-Jiménez, Bryan; Johnson, Monique E; Montoro Bustos, Antonio R; Murphy, Karen E; Winchester, Michael R; Vega Baudrit, José R

2017-01-01

Silver nanoparticles (AgNPs) show different physical and chemical properties compared to their macroscale analogs. This is primarily due to their small size and, consequently, the exceptional surface area of these materials. Presently, advances in the synthesis, stabilization, and production of AgNPs have fostered a new generation of commercial products and intensified scientific investigation within the nanotechnology field. The use of AgNPs in commercial products is increasing and impacts on the environment and human health are largely unknown. This article discusses advances in AgNP production and presents an overview of the commercial, societal, and environmental impacts of this emerging nanoparticle (NP), and nanomaterials in general. Finally, we examine the challenges associated with AgNP characterization, discuss the importance of the development of NP reference materials (RMs) and explore their role as a metrological mechanism to improve the quality and comparability of NP measurements.

Use of new scientific developments in regulatory risk assessments: challenges and opportunities.

PubMed

Tarazona, Jose V

2013-07-01

Since the 1990s, science based ecological risk assessments constitute an essential tool for supporting decision making in the regulatory context. Using the European REACH Regulation as example, this article presents the challenges and opportunities for new scientific developments within the area of chemical control and environmental protection. These challenges can be sorted out in 3 main related topics (sets). In the short term, the challenges are directly associated with the regulatory requirements, required for facilitating a scientifically sound implementation of the different obligations for industry and authorities. It is important to mention that although the actual tools are different due to the regulatory requirements, the basic needs are still the same as those addressed in the early 1990s: understanding the ecological relevance of the predicted effects, including the uncertainty, and facilitating the link with the socio-economic assessment. The second set of challenges covers the opportunities for getting an added value from the regulatory efforts. The information compiled through REACH registration and notification processes is analyzed as source for new integrative developments for assessing the combined chemical risk at the regional level. Finally, the article discusses the challenge of inverting the process and developing risk assessment methods focusing on the receptor, the individual or ecosystem, instead of on the stressor or source. These approaches were limited in the past due to the lack of information, but the identification and dissemination of standard information, including uses, manufacturing sites, physical-chemical, environmental, ecotoxicological, and toxicological properties as well as operational conditions and risk management measures for thousands of chemicals, combined by the knowledge gathered through large scale monitoring programs and spatial information systems is generating new opportunities. The challenge is liking predictions and measured data in an integral "-omic type" approach, considering collectively data from different sources and offering a complete assessment of the chemical risk of individuals and ecosystems, with new conceptual approaches that could be defined as "risk-omics based" paradigms and models. Copyright © 2013 SETAC.

Resistance to tumour challenge after tumour laser thermotherapy is associated with a cellular immune response

PubMed Central

Ivarsson, K; Myllymäki, L; Jansner, K; Stenram, U; Tranberg, K-G

2005-01-01

Previous studies in our laboratory have shown that interstitial laser thermotherapy (ILT) of an experimental liver tumour is superior to surgical excision, at least partly due to a laser-induced immunological effect. The aim of the present study was to investigate the time–response relationship of the ILT-induced immunisation and the cellular response of macrophages and lymphocytes. A dimethylhydrazine-induced adenocarcinoma was transplanted into the liver of syngeneic rats. Rats with tumour were treated 6–8 days later (tumour size 0.25–0.40 cm3) with ILT of tumour or resection of the tumour-bearing lobe. Two groups of rats without tumour were treated with resection of a normal liver lobe or ILT of normal liver. A challenging tumour was implanted into the liver of each rat 2, 5 or 10 weeks after primary treatment. Rats were killed 6, 12 and 48 days (or earlier due to their condition) after challenge (n=8 in all groups). Immunohistochemical techniques were used to determine lymphocytes (CD8, CD4) and macrophages (ED1, ED2) in rats having had treatment of a primary tumour. Interstitial laser thermotherapy of the first tumour was followed by eradication of challenging tumour and absence of tumour spread. This contrasted with rapid growth and spread of challenging tumour in the other groups. In the challenging vital tumour tissue and in the interface between the tumour and surroundings, the number of ED1 macrophages and CD8 lymphocytes was higher in rats having been treated with the ILT of tumour than in those having undergone resection of the tumour-bearing lobe. The number of ED2 macrophages and CD4 lymphocytes was low and did not vary between these two groups. Interstitial laser thermotherapy elicited an immune response that eradicated a challenging tumour and was associated with increased numbers of tumour-infiltrating macrophages and CD8 lymphocytes. PMID:16091763

Jaundice and life-threatening hemobilia: an uncommon presentation of choledochal cyst.

PubMed

Koh, Peng Soon; Yoong, Boon Koon; Vijayananthan, Anushya; Nawawi, Ouzreiah; Mahadeva, Sanjiv

2013-08-01

Hemobilia with jaundice as a result of cholestasis and bleeding from choledochal cyst is uncommon. Ascertaining the diagnosis is often challenging and delayed diagnosis can lead to significant consequences due to hemodynamic instability, particularly in elderly patients. Although surgery remains the definitive treatment modality, interventional radiology for hemostasis has been increasingly recognized as an option. In this manuscript, we described two Malaysian cases of jaundice and hemobilia associated with choledochal cysts and the challenges related with clinical diagnosis and management. © 2013 The Authors. Journal of Digestive Diseases © 2013 Wiley Publishing Asia Pty Ltd and Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine.

Parametric modeling studies of turbulent non-premixed jet flames with thin reaction zones

NASA Astrophysics Data System (ADS)

Wang, Haifeng

2013-11-01

The Sydney piloted jet flame series (Flames L, B, and M) feature thinner reaction zones and hence impose greater challenges to modeling than the Sanida Piloted jet flames (Flames D, E, and F). Recently, the Sydney flames received renewed interest due to these challenges. Several new modeling efforts have emerged. However, no systematic parametric modeling studies have been reported for the Sydney flames. A large set of modeling computations of the Sydney flames is presented here by using the coupled large eddy simulation (LES)/probability density function (PDF) method. Parametric studies are performed to gain insight into the model performance, its sensitivity and the effect of numerics.

Sleep bruxism: challenges and restorative solutions

PubMed Central

Mengatto, Cristiane Machado; Coelho-de-Souza, Fábio Herrmann; de Souza Junior, Oswaldo Baptista

2016-01-01

Bruxism is a parafunctional activity related to clenching or grinding the teeth and tooth wear can be a consequence of sleep bruxism (SB). Management of severe tooth wear due to SB is a challenging situation because of the common reduced amount of remaining dental structure and loss of vertical dimension of occlusion. Rationale for the planning of oral rehabilitation of patients with SB presenting severe tooth wear should rely on evidence-based approaches; however, few studies have discussed properties of dental materials for SB rehabilitation and how to cosmetically manage severe tooth wear. This review aimed to provide an overview into bruxism cosmetic rehabilitation and how this can be implemented with good outcomes for the patient. PMID:27217798

Challenges in managing a mother with a dual diagnosis of peripartum cardiomyopathy and paranoid schizophrenia - a case report.

PubMed

Weerasundera, Rajiv; Yogaratnam, Jegan

2013-01-01

Psychotic illness has a low incidence in the puerperal period. Peripartum cardiomyopathy as a complication of pregnancy is also rare. We report a case where the above two conditions occurred simultaneously in a patient and posed significant difficulties in the clinical management. She was diagnosed as having paranoid schizophrenia and peripartum cardiomyopathy. Many of the antipsychotics were contraindicated, and electroconvulsive therapy could not be administered due to the added risks involved with regard to anesthesia. She was therefore managed with clonazepam and olanzapine. This case highlights the challenges in a patient with a psychiatric illness presenting with comorbid physical illness. Copyright © 2013 Elsevier Inc. All rights reserved.

Turbofan Engine Core Compartment Vent Aerodynamic Configuration Development Methodology

NASA Technical Reports Server (NTRS)

Hebert, Leonard J.

2006-01-01

This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment vent for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment vents exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment vents is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in vent exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.

Low-Cost High-Precision PIAA Optics for High Contrast Imaging with Exo-Planet Coronagraphs

NASA Technical Reports Server (NTRS)

Balasubramanian, Kunjithapatham; Shaklan, Stuart B.; Pueyo, Laurent; Wilson, Daniel W.; Guyon, Olivier

2010-01-01

PIAA optics for high contrast imaging present challenges in manufacturing and testing due to their large surface departures from aspheric profiles at the aperture edges. With smaller form factors and consequent smaller surface deformations (<50 microns), fabrication of these mirrors with diamond turning followed by electron beam lithographic techniques becomes feasible. Though such a design reduces the system throughput to approx.50%, it still provides good performance down to 2 lambda/D inner working angle. With new achromatic focal plane mask designs, the system performance can be further improved. We report on the design, expected performance, fabrication challenges, and initial assessment of such novel PIAA optics.

Challenges of In Space Robotic Servicing

NASA Technical Reports Server (NTRS)

Roberts, Brian John

2015-01-01

As future space missions extend beyond the friendly confines of low earth orbit, robots are becoming an increasingly vital component on flight manifests. While the main focus to-date has been on satellite servicing due to its high commercial potential, robots are also being considered for orbital debris removal, space construction, and asteroid sample retrieval. The robotic technologies and automation required to carry out these missions represent a significant advancement beyond the manipulation technology used previously on the Space Shuttle, the International Space Station, and planetary rovers. While higher demands are being driven by the more ambitious nature of the tasks, the handling of uncooperative targets such as satellites and asteroids, present a greater challenge.

Progress, challenges and perspectives on fish gamete cryopreservation: A mini-review.

PubMed

Asturiano, Juan F; Cabrita, Elsa; Horváth, Ákos

2017-05-01

Protocols for the cryopreservation of fish gametes have been developed for many different fish species, in special, freshwater salmonids and cyprinids. Methods for sperm freezing have progressed during the last decades due to the increasing number of potential applications: aquaculture (genetic improvement programs, broodstock management, helping with species having reproductive problems), biotechnology studies using model fish species (preservation of transgenic or mutant lines), cryobanking of genetic resources from endangered species, etc. This mini-review tries to give an overview of the present situation of this area of research, identifying the main challenges and perspectives, redirecting the reader to more in-depth reviews and papers. Copyright © 2016 Elsevier Inc. All rights reserved.

A Brief Review on Multivalent Intercalation Batteries with Aqueous Electrolytes.

PubMed

Guduru, Ramesh K; Icaza, Juan C

2016-02-26

Rapidly growing global demand for high energy density rechargeable batteries has driven the research toward developing new chemistries and battery systems beyond Li-ion batteries. Due to the advantages of delivering more than one electron and giving more charge capacity, the multivalent systems have gained considerable attention. At the same time, affordability, ease of fabrication and safety aspects have also directed researchers to focus on aqueous electrolyte based multivalent intercalation batteries. There have been a decent number of publications disclosing capabilities and challenges of several multivalent battery systems in aqueous electrolytes, and while considering an increasing interest in this area, here, we present a brief overview of their recent progress, including electrode chemistries, functionalities and challenges.

Review of Electronics Based on Single-Walled Carbon Nanotubes.

PubMed

Cao, Yu; Cong, Sen; Cao, Xuan; Wu, Fanqi; Liu, Qingzhou; Amer, Moh R; Zhou, Chongwu

2017-08-14

Single-walled carbon nanotubes (SWNTs) are extremely promising materials for building next-generation electronics due to their unique physical and electronic properties. In this article, we will review the research efforts and achievements of SWNTs in three electronic fields, namely analog radio-frequency electronics, digital electronics, and macroelectronics. In each SWNT-based electronic field, we will present the major challenges, the evolutions of the methods to overcome these challenges, and the state-of-the-art of the achievements. At last, we will discuss future directions which could lead to the broad applications of SWNTs. We hope this review could inspire more research on SWNT-based electronics, and accelerate the applications of SWNTs.

Comparison of Traditional and Innovative Techniques to Solve Technical Challenges

NASA Technical Reports Server (NTRS)

Perchonok, Michele

2011-01-01

This slide presentation reviews the use of traditional and innovative techniques to solve technical challenges in food storage technology. The planning for a mission to Mars is underway, and the food storage technology improvements requires that improvements be made. This new technology is required, because current food storage technology is inadequate,refrigerators or freezers are not available for food preservation, and that a shelf life of 5 years is expected. A 10 year effort to improve food packaging technology has not enhanced significantly food packaging capabilities. Two innovation techniques were attempted InnoCentive and Yet2.com and have provided good results, and are still under due diligence for solver verification.

Challenges to reestablishment of free-ranging populations of black-footed ferrets

USGS Publications Warehouse

Biggins, D.E.; Godbey, J.L.

2003-01-01

The black-footed ferret (Mustela nigripes) of North America is critically endangered due in part to its extreme specialization on formerly stable and abundant prairie dogs (Cynomys). Its close relative, the Siberian polecat (M. eversmannii) seems to have been subjected to a varying environment that was not conducive to specialization. One source of environmental variation in Asian steppes was plague (caused by Yersina pestis), which was absent from North America. Introduction of plague to North America presents serious challenges to ferret recovery. Partial solutions to other biological and political problems have been found, resulting in improved production in captivity, increased survival post-release, and thriving populations in plague-free South Dakota.

From Nonissue to Healthcare Crisis: A Historical Review of Aging and Dying With an Intellectual and Developmental Disability.

PubMed

McGinley, Jacqueline M

2016-04-01

Individuals with intellectual and developmental disabilities are living unprecedentedly longer lives primarily due to the long-term benefits of the deinstitutionalization movement and widespread improvements in health outcomes. However, the consequences of this protracted aging process are significant, complex, and often poor not only for the individuals and their caregivers but for the mainstream healthcare community. This article will explore, utilizing a constructionist perspective, how these challenges evolved from a nonissue to an impending crisis in less than 25 years. Additionally, present-day efforts by researchers, policymakers, and practitioners to address these challenges will be explored and recommendations will be made for future directions.

Challenges to reestablishment of free-ranging populations of black-footed ferrets.

PubMed

Biggins, Dean E; Godbey, Jerry L

2003-08-01

The black-footed ferret (Mustela nigripes) of North America is critically endangered due in part to its extreme specialization on formerly stable and abundant prairie dogs (Cynomys). Its close relative, the Siberian polecat (M. eversmannii) seems to have been subjected to a varying environment that was not conductive to specialization. One source of environmental variation in Asian steppes was plague (caused by Yersina pestis), which was absent from North America. Introduction of plague to North America presents serious challenges to ferret recovery. Partial solutions to other biological and political problems have been found, resulting in improved production in captivity, increased survival post-release, and thriving populations in plague-free South Dakota.

Quantum sequencing: opportunities and challenges

NASA Astrophysics Data System (ADS)

di Ventra, Massimiliano

Personalized or precision medicine refers to the ability of tailoring drugs to the specific genome and transcriptome of each individual. It is however not yet feasible due the high costs and slow speed of present DNA sequencing methods. I will discuss a sequencing protocol that requires the measurement of the distributions of transverse tunneling currents during the translocation of single-stranded DNA into nanochannels. I will show that such a quantum sequencing approach can reach unprecedented speeds, without requiring any chemical preparation, amplification or labeling. I will discuss recent experiments that support these theoretical predictions, the advantages of this approach over other sequencing methods, and stress the challenges that need to be overcome to render it commercially viable.

Industrial Development and Challenges of Water Pollution in Coastal Areas: The Case of Surat, India

NASA Astrophysics Data System (ADS)

Bansal, Neeru

2018-03-01

Industrialisation plays an important role in the economic development of a country, however, pollution is the inevitable price paid for this development. Surat, a major industrial hub in western India, is located on the bank of the river Tapi and extends up to the Arabian Sea. The city is characterised by the presence of a number of creeks (known as ‘khadis’ in local language). This paper focusses on the industrial development in Surat and the challenges faced by the city due to water pollution. A constant deterioration in the quality of surface water resources has been observed due to discharge of treated or partially treated effluents from the industries. The problem of water pollution becomes critical due to increase in frequency of flooding, risks faced by the city due to climate change and the ineffective environmental governance. The paper provides insights into the challenges faced by the city and the learnings can lead to adoption of policy initiatives and other measures which can effectively address these challenges.

Adaptive Pathways: Possible Next Steps for Payers in Preparation for Their Potential Implementation.

PubMed

Vella Bonanno, Patricia; Ermisch, Michael; Godman, Brian; Martin, Antony P; Van Den Bergh, Jesper; Bezmelnitsyna, Liudmila; Bucsics, Anna; Arickx, Francis; Bybau, Alexander; Bochenek, Tomasz; van de Casteele, Marc; Diogene, Eduardo; Eriksson, Irene; Fürst, Jurij; Gad, Mohamed; Greičiūtė-Kuprijanov, Ieva; van der Graaff, Martin; Gulbinovic, Jolanta; Jones, Jan; Joppi, Roberta; Kalaba, Marija; Laius, Ott; Langner, Irene; Mardare, Ileana; Markovic-Pekovic, Vanda; Magnusson, Einar; Melien, Oyvind; Meshkov, Dmitry O; Petrova, Guenka I; Selke, Gisbert; Sermet, Catherine; Simoens, Steven; Schuurman, Ad; Ramos, Ricardo; Rodrigues, Jorge; Zara, Corinne; Zebedin-Brandl, Eva; Haycox, Alan

2017-01-01

Medicines receiving a conditional marketing authorization through Medicines Adaptive Pathways to Patients (MAPPs) will be a challenge for payers. The "introduction" of MAPPs is already seen by the European Medicines Agency (EMA) as a fait accompli, with payers not consulted or involved. However, once medicines are approved through MAPPs, they will be evaluated for funding by payers through different activities. These include Health Technology Assessment (HTA) with often immature clinical data and high uncertainty, financial considerations, and negotiations through different types of agreements, which can require monitoring post launch. Payers have experience with new medicines approved through conditional approval, and the fact that MAPPs present additional challenges is a concern from their perspective. There may be some activities where payers can collaborate. The final decisions on whether to reimburse a new medicine via MAPPs will have more variation than for medicines licensed via conventional processes. This is due not only to increasing uncertainty associated with medicines authorized through MAPPs but also differences in legal frameworks between member states. Moreover, if the financial and side-effect burden from the period of conditional approval until granting full marketing authorization is shifted to the post-authorization phase, payers may have to bear such burdens. Collection of robust data during routine clinical use is challenging along with high prices for new medicines during data collection. This paper presents the concept of MAPPs and possible challenges. Concerns and potential ways forward are discussed and a number of recommendations are presented from the perspective of payers.

Challenges of caring for children with mental disorders: Experiences and views of caregivers attending the outpatient clinic at Muhimbili National Hospital, Dar es Salaam - Tanzania.

PubMed

Ambikile, Joel Semel; Outwater, Anne

2012-07-05

It is estimated that world-wide up to 20 % of children suffer from debilitating mental illness. Mental disorders that pose a significant concern include learning disorders, hyperkinetic disorders (ADHD), depression, psychosis, pervasive development disorders, attachment disorders, anxiety disorders, conduct disorder, substance abuse and eating disorders. Living with such children can be very stressful for caregivers in the family. Therefore, determination of challenges of living with these children is important in the process of finding ways to help or support caregivers to provide proper care for their children. The purpose of this study was to explore the psychological and emotional, social, and economic challenges that parents or guardians experience when caring for mentally ill children and what they do to address or deal with them. A qualitative study design using in-depth interviews and focus group discussions was applied. The study was conducted at the psychiatric unit of Muhimbili National Hospital in Tanzania. Two focus groups discussions (FGDs) and 8 in-depth interviews were conducted with caregivers who attended the psychiatric clinic with their children. Data analysis was done using content analysis. The study revealed psychological and emotional, social, and economic challenges caregivers endure while living with mentally ill children. Psychological and emotional challenges included being stressed by caring tasks and having worries about the present and future life of their children. They had feelings of sadness, and inner pain or bitterness due to the disturbing behaviour of the children. They also experienced some communication problems with their children due to their inability to talk. Social challenges were inadequate social services for their children, stigma, burden of caring task, lack of public awareness of mental illness, lack of social support, and problems with social life. The economic challenges were poverty, child care interfering with various income generating activities in the family, and extra expenses associated with the child's illness. Caregivers of mentally ill children experience various psychological and emotional, social, and economic challenges. Professional assistance, public awareness of mental illnesses in children, social support by the government, private sector, and non-governmental organizations (NGOs) are important in addressing these challenges.

Acute left main coronary artery occlusion

PubMed Central

Burgazli, K. Mehmet; Bilgin, Mehmet; Soydan, Nedim; Chasan, Ridvan; Erdogan, Ali

2013-01-01

The treatment of an acute left main coronary artery occlusion still poses a challenge. In this case report we present a 50-year-old patient with an acute occlusion of the left main artery. After a successful angioplasty without “stenting” due to the complexity of the stenosis the patient underwent a successful bypass surgery. We discuss the therapeutic options of acute left main occlusion regarding medical, interventional and surgical options. PMID:24353543

Reproductive Disorders in Snakes.

PubMed

Di Girolamo, Nicola; Selleri, Paolo

2017-05-01

Reproduction of snakes is one of the challenging aspects of herpetology medicine. Due to the complexity of reproduction, several disorders may present before, during, or after this process. This article describes the physical examination, and radiographic, ultrasonographic, and endoscopic findings associated with reproductive disorders in snakes. Surgical techniques used to resolve reproductive disorders in snakes are described. Finally, common reproductive disorders in snakes are individually discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Human Salivary Alpha-Amylase (EC.3.2.1.1) Activity and Periodic Acid and Schiff Reactive (PAS) Staining: A Useful Tool to Study Polysaccharides at an Undergraduate Level

ERIC Educational Resources Information Center

Fernandes, Ruben; Correia, Rossana; Fonte, Rosalia; Prudencio, Cristina

2006-01-01

Health science education is presently in discussion throughout Europe due to the Bologna Declaration. Teaching basic sciences such as biochemistry in a health sciences context, namely in allied heath education, can be a challenging task since the students of preclinical health sciences are not often convinced that basic sciences are clinically…

Computational Simulation of High-Speed Projectiles in Air, Water, and Sand

DTIC Science & Technology

2007-12-03

Supercavitating projectiles can be used for underwater mine neutralization, beach and surf zone mine clearance, littoral ASW, and neutralizing combat...swimmer systems. The water entry phase of flight is interesting and challenging due to projectile transitioning from flight in air to supercavitating ...is formed. Neaves and Edwards [1] simulated this case using a supercavitation code developed at NSWC-PC. The results presented are in good agreement

Surgical management of chest wall trauma.

PubMed

Molnar, Tamas F

2010-11-01

Recent paradigm shift in major trauma profile elevates chest wall injuries among the most important topics of the specialty. Due to mass casualties of terror attacks and asymmetric warfare, civilian and military trauma care challenges thoracic surgery, traumatology, intensive anesthesiology, and related specialties. Contemporary advances of the main issues are systemically presented and discussed, such as soft tissue and bony structure injuries, complex traumas like flail chest, and extensively destroyed chest wall.

[Lung cancer and rheumatoid arthritis. An interdisciplinary challenge].

PubMed

Rubbert-Roth, A; Zander, T; Kneitz, C; Baerwald, C; Wirtz, H; Witt, C

2016-02-01

Lung cancer is a frequently occurring disease, particularly in the elderly; however, within the last 10 years the pharmaceutical treatment of lung cancer has been significantly improved. Due to a better understanding of the pathophysiological events and the identification of molecular subgroups of lung tumors, new therapeutic drugs have been developed that significantly prolong survival of patients with the respective molecular pattern. In particular immunotherapeutic agents, such as programmed death-ligand 1 (PD-L1) and programmed death 1 (PD1) antibodies have shown promising clinical results in a subgroup of lung cancer patients. Due to the high incidence of both lung cancer and rheumatic diseases they often occur together, which necessitates an interdisciplinary management. The success of improved therapy of lung cancer has led to a greater focus on the treatment of comorbidities; however, interventions into the immune system by immune checkpoint inhibitors can lead to new challenges when an autoimmune disease is simultaneously present. The possibility of an effective screening for lung cancer in the future also presents the prospect of an improvement in mortality, which raises the question of the optimal monitoring of patients with rheumatoid arthritis (RA) under immunosuppressive therapy. The aim of this review is to discuss the interaction between lung cancer and RA with respect to the currently available data.

Trends in IT Innovation to Build a Next Generation Bioinformatics Solution to Manage and Analyse Biological Big Data Produced by NGS Technologies.

PubMed

de Brevern, Alexandre G; Meyniel, Jean-Philippe; Fairhead, Cécile; Neuvéglise, Cécile; Malpertuy, Alain

2015-01-01

Sequencing the human genome began in 1994, and 10 years of work were necessary in order to provide a nearly complete sequence. Nowadays, NGS technologies allow sequencing of a whole human genome in a few days. This deluge of data challenges scientists in many ways, as they are faced with data management issues and analysis and visualization drawbacks due to the limitations of current bioinformatics tools. In this paper, we describe how the NGS Big Data revolution changes the way of managing and analysing data. We present how biologists are confronted with abundance of methods, tools, and data formats. To overcome these problems, focus on Big Data Information Technology innovations from web and business intelligence. We underline the interest of NoSQL databases, which are much more efficient than relational databases. Since Big Data leads to the loss of interactivity with data during analysis due to high processing time, we describe solutions from the Business Intelligence that allow one to regain interactivity whatever the volume of data is. We illustrate this point with a focus on the Amadea platform. Finally, we discuss visualization challenges posed by Big Data and present the latest innovations with JavaScript graphic libraries.

Trends in IT Innovation to Build a Next Generation Bioinformatics Solution to Manage and Analyse Biological Big Data Produced by NGS Technologies

PubMed Central

de Brevern, Alexandre G.; Meyniel, Jean-Philippe; Fairhead, Cécile; Neuvéglise, Cécile; Malpertuy, Alain

2015-01-01

Sequencing the human genome began in 1994, and 10 years of work were necessary in order to provide a nearly complete sequence. Nowadays, NGS technologies allow sequencing of a whole human genome in a few days. This deluge of data challenges scientists in many ways, as they are faced with data management issues and analysis and visualization drawbacks due to the limitations of current bioinformatics tools. In this paper, we describe how the NGS Big Data revolution changes the way of managing and analysing data. We present how biologists are confronted with abundance of methods, tools, and data formats. To overcome these problems, focus on Big Data Information Technology innovations from web and business intelligence. We underline the interest of NoSQL databases, which are much more efficient than relational databases. Since Big Data leads to the loss of interactivity with data during analysis due to high processing time, we describe solutions from the Business Intelligence that allow one to regain interactivity whatever the volume of data is. We illustrate this point with a focus on the Amadea platform. Finally, we discuss visualization challenges posed by Big Data and present the latest innovations with JavaScript graphic libraries. PMID:26125026

Secure Skyline Queries on Cloud Platform

PubMed Central

Liu, Jinfei; Yang, Juncheng; Xiong, Li; Pei, Jian

2017-01-01

Outsourcing data and computation to cloud server provides a cost-effective way to support large scale data storage and query processing. However, due to security and privacy concerns, sensitive data (e.g., medical records) need to be protected from the cloud server and other unauthorized users. One approach is to outsource encrypted data to the cloud server and have the cloud server perform query processing on the encrypted data only. It remains a challenging task to support various queries over encrypted data in a secure and efficient way such that the cloud server does not gain any knowledge about the data, query, and query result. In this paper, we study the problem of secure skyline queries over encrypted data. The skyline query is particularly important for multi-criteria decision making but also presents significant challenges due to its complex computations. We propose a fully secure skyline query protocol on data encrypted using semantically-secure encryption. As a key subroutine, we present a new secure dominance protocol, which can be also used as a building block for other queries. Finally, we provide both serial and parallelized implementations and empirically study the protocols in terms of efficiency and scalability under different parameter settings, verifying the feasibility of our proposed solutions. PMID:28883710

Chronic suppurative otitis media due to nontuberculous mycobacteria: A case of successful treatment with topical boric acid.

PubMed

Lefebvre, Marie-Astrid; Quach, Caroline; Daniel, Sam J

2015-07-01

Nontuberculous mycobacteria (NTM) are an increasingly recognized cause of chronic suppurative otitis media in children with tympanostomy tubes. Treatment of this condition is difficult and typically requires a combination of systemic antibiotics and surgical debridement. We present the first case of a 2-year-old male with chronic suppurative otitis media due to NTM who failed systemic antibiotic therapy and was successfully managed with topical boric acid powder. This report highlights the challenges involved in treating this infection, and introduces boric acid as a potentially valuable component of therapy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Uncharted territories of the patent-restoration due-diligence challenge.

PubMed

Gaudry, Kate S

2011-01-01

The innovation and development incentives offered by the patent system are mitigated if a substantial portion of the patent term is lost while obtaining product approval through the Food and Drug Administration (FDA). The Drug Price Competition and Patent Restoration Act was enacted to return some of the lost patent term to the patentee. However, any person can petition the FDA, contending that the patentee did not act with due diligence in seeking FDA approval of the product during the regulatory review period. A successful challenge will reduce the restored term, such that the patentee is not compensated for time lost due to his own non-diligent actions. While the current due-diligence regulations provide a vague and flexible standard, earlier drafts of the regulations and FDA responses to comments provide insight as to the types of factors the FDA is likely to consider when assessing an applicant's diligence. A due-diligence petition has only been filed three times, and in none of these cases did the FDA issue a decision based on substantive diligence matters. Still, detailed examination of these petitions is also instructive in predicting the success of due-diligence challenges. Statute-imposed maximums and applicants' own incentives to act diligently may minimize the utility of the due-diligence challenges in some contexts. However, in other contexts, I propose that these petitions offer a feasible approach towards limiting pharmaceutical monopolies.

Promises and Challenges of Thorium Implementation for Transuranic Transmutation - 13550

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franceschini, F.; Lahoda, E.; Wenner, M.

2013-07-01

This paper focuses on the challenges of implementing a thorium fuel cycle for recycle and transmutation of long-lived actinide components from used nuclear fuel. A multi-stage reactor system is proposed; the first stage consists of current UO{sub 2} once-through LWRs supplying transuranic isotopes that are continuously recycled and burned in second stage reactors in either a uranium (U) or thorium (Th) carrier. The second stage reactors considered for the analysis are Reduced Moderation Pressurized Water Reactors (RMPWRs), reconfigured from current PWR core designs, and Fast Reactors (FRs) with a burner core design. While both RMPWRs and FRs can in principlemore » be employed, each reactor and associated technology has pros and cons. FRs have unmatched flexibility and transmutation efficiency. RMPWRs have higher fuel manufacturing and reprocessing requirements, but may represent a cheaper solution and the opportunity for a shorter time to licensing and deployment. All options require substantial developments in manufacturing, due to the high radiation field, and reprocessing, due to the very high actinide recovery ratio to elicit the claimed radiotoxicity reduction. Th reduces the number of transmutation reactors, and is required to enable a viable RMPWR design, but presents additional challenges on manufacturing and reprocessing. The tradeoff between the various options does not make the choice obvious. Moreover, without an overarching supporting policy in place, the costly and challenging technologies required inherently discourage industrialization of any transmutation scheme, regardless of the adoption of U or Th. (authors)« less

Bilateral Ossified Chronic Subdural Hematoma Presenting as Diabetes Insipidus-Case Report and Literature Review.

PubMed

Siddiqui, Saquib A; Singh, Pankaj Kumar; Sawarkar, Dattaraj; Singh, Manmohanjit; Sharma, Bhawani S

2017-02-01

Calcified chronic subdural hematomas are an occurrence rarely seen in neurosurgical clinical practice. And when they occur bilaterally, the radiologic image they present is fascinating, as is the clinical presentation, but their management may be challenging. They have been reported to present with a multitude of neurologic deficits but never with diabetes insipidus, which is described here. Due to the rarity of this pathology, the management protocol is not well defined, though there have been quite a few papers on this condition. This review article gathers information published over the years on this rare entity to suggest a treatment protocol. Copyright © 2016 Elsevier Inc. All rights reserved.

Integrating Social Media and Mobile Sensor Data for Clinical Decision Support: Concept and Requirements.

PubMed

Denecke, Kerstin

2016-01-01

Social media are increasingly used by individuals for the purpose of collecting data and reporting on the personal health status, on health issues, symptoms and experiences with treatments. Beyond, fitness trackers are more used by individuals to monitor their fitness and health. The health data that is becoming available due to these developments could provide a valuable source for continuous health monitoring, prevention of unexpected health events and clinical decision making since it gives insights into behavior and life habits. However, an integration of the data is challenging. This paper aims triggering the discussion about this current topic. We present a concept for integrating social media data with mobile sensor data and clinical data using digital patient modelling. Further, we collect requirements and challenges for a possible realization of the concept. Challenges include the data volume, reliability and semantic interoperability.

Development Challenges of Game-Changing Entry System Technologies From Concept to Mission Infusion

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Beck, Robin; Ellerby, Don; Feldman, Jay; Gage, Peter; Munk, Michelle; Wercinski, Paul

2016-01-01

Realization within the US and NASA that future exploration both Human and Robotic will require innovative new technologies led to the creation of the Space Technology Mission Directorate and investment in game changing technologies with high pay-off. Some of these investments will see success and others, due to many of the constraints, will not attain their goal. The co-authors of this proposed presentation have been involved from concept to mission infusion aspects of entry technologies that are game changing. The four example technologies used to describe the challenges experienced along the pathways to success are at different levels of maturity. They are Conformal, 3-D MAT, HEEET and ADEPT. The four examples in many ways capture broad aspects of the challenges of maturation and illustrate what led some to be exceptionally successful and how others had to be altered in order remain viable game changing technologies.

RRAM-based hardware implementations of artificial neural networks: progress update and challenges ahead

NASA Astrophysics Data System (ADS)

Prezioso, M.; Merrikh-Bayat, F.; Chakrabarti, B.; Strukov, D.

2016-02-01

Artificial neural networks have been receiving increasing attention due to their superior performance in many information processing tasks. Typically, scaling up the size of the network results in better performance and richer functionality. However, large neural networks are challenging to implement in software and customized hardware are generally required for their practical implementations. In this work, we will discuss our group's recent efforts on the development of such custom hardware circuits, based on hybrid CMOS/memristor circuits, in particular of CMOL variety. We will start by reviewing the basics of memristive devices and of CMOL circuits. We will then discuss our recent progress towards demonstration of hybrid circuits, focusing on the experimental and theoretical results for artificial neural networks based on crossbarintegrated metal oxide memristors. We will conclude presentation with the discussion of the remaining challenges and the most pressing research needs.

Lessons in the Design and Characterization Testing of the Semi-Span Super-Sonic Transport (S4T) Wind-Tunnel Model

NASA Technical Reports Server (NTRS)

2012-01-01

This paper focuses on some of the more challenging design processes and characterization tests of the Semi-Span Super-Sonic Transport (S4T)-Active Controls Testbed (ACT). The model was successfully tested in four entries in the National Aeronautics and Space Administration Langley Transonic Dynamics Tunnel to satisfy the goals and objectives of the Fundamental Aeronautics Program Supersonic Project Aero-Propulso-Servo-Elastic effort. Due to the complexity of the S4T-ACT, only a small sample of the technical challenges for designing and characterizing the model will be presented. Specifically, the challenges encountered in designing the model include scaling the Technology Concept Airplane to model scale, designing the model fuselage, aileron actuator, and engine pylons. Characterization tests included full model ground vibration tests, wing stiffness measurements, geometry measurements, proof load testing, and measurement of fuselage static and dynamic properties.

The Role of School Nurses, Challenges, and Reactions to Delegation Legislation: A Qualitative Approach.

PubMed

Lineberry, Michelle; Whitney, Elizabeth; Noland, Melody

2018-06-01

Passage of new laws, national standards regarding delegation, and the recommendation for at least one full-time nurse in every school have provided more visibility to the role of school nurses. Recent legislative amendments in Kentucky presented an opportunity to examine how the role of the school nurse is changing. Aims were to describe the (1) role of school nurses in Kentucky, (2) impact of school nurses, (3) challenges faced by school nurses, and (4) impact of budget cuts and legislation. Three focus groups were conducted. School nurses faced challenges of limited time and resources, communication barriers, and multiple documentation requirements. Nurses' greatest impacts were their availability, recognition of psychosocial problems and health concerns, and connection with resources. Nurses had not yet encountered many changes due to new legislation that expanded delegation of diabetes-related tasks to unlicensed school personnel, but some had concerns about possible negative effects while others expressed support.

Toward a Social Psychophysics of Face Communication.

PubMed

Jack, Rachael E; Schyns, Philippe G

2017-01-03

As a highly social species, humans are equipped with a powerful tool for social communication-the face. Although seemingly simple, the human face can elicit multiple social perceptions due to the rich variations of its movements, morphology, and complexion. Consequently, identifying precisely what face information elicits different social perceptions is a complex empirical challenge that has largely remained beyond the reach of traditional methods. In the past decade, the emerging field of social psychophysics has developed new methods to address this challenge, with the potential to transfer psychophysical laws of social perception to the digital economy via avatars and social robots. At this exciting juncture, it is timely to review these new methodological developments. In this article, we introduce and review the foundational methodological developments of social psychophysics, present work done in the past decade that has advanced understanding of the face as a tool for social communication, and discuss the major challenges that lie ahead.

Chyle fistula in advanced and metastatic thyroid cancer

PubMed Central

Sánchez, Juan Guillermo; Dionigi, Gianlorenzo

2017-01-01

Background Chyle fistula (CF) is a rare but challenging condition for the surgeon and the patient’s health. Methods A retrospective review of single surgeon’s case load in a 12-year period is presented, reviewing the case of those patients presenting with a CF. Results Three patients were found during this study period from more than 1,050 surgeries performed due to thyroid cancer. Patients underwent extensive lymph node dissection for advanced, metastatic and infiltrative disease. In all patients, a long hospital stay and surgical re-interventions were required. Conclusions A description of the management of CF is presented along with a review of current Literature. PMID:29142832

Toward reliable and repeatable automated STEM-EDS metrology with high throughput

NASA Astrophysics Data System (ADS)

Zhong, Zhenxin; Donald, Jason; Dutrow, Gavin; Roller, Justin; Ugurlu, Ozan; Verheijen, Martin; Bidiuk, Oleksii

2018-03-01

New materials and designs in complex 3D architectures in logic and memory devices have raised complexity in S/TEM metrology. In this paper, we report about a newly developed, automated, scanning transmission electron microscopy (STEM) based, energy dispersive X-ray spectroscopy (STEM-EDS) metrology method that addresses these challenges. Different methodologies toward repeatable and efficient, automated STEM-EDS metrology with high throughput are presented: we introduce the best known auto-EDS acquisition and quantification methods for robust and reliable metrology and present how electron exposure dose impacts the EDS metrology reproducibility, either due to poor signalto-noise ratio (SNR) at low dose or due to sample modifications at high dose conditions. Finally, we discuss the limitations of the STEM-EDS metrology technique and propose strategies to optimize the process both in terms of throughput and metrology reliability.

Implementation of workflow engine technology to deliver basic clinical decision support functionality.

PubMed

Huser, Vojtech; Rasmussen, Luke V; Oberg, Ryan; Starren, Justin B

2011-04-10

Workflow engine technology represents a new class of software with the ability to graphically model step-based knowledge. We present application of this novel technology to the domain of clinical decision support. Successful implementation of decision support within an electronic health record (EHR) remains an unsolved research challenge. Previous research efforts were mostly based on healthcare-specific representation standards and execution engines and did not reach wide adoption. We focus on two challenges in decision support systems: the ability to test decision logic on retrospective data prior prospective deployment and the challenge of user-friendly representation of clinical logic. We present our implementation of a workflow engine technology that addresses the two above-described challenges in delivering clinical decision support. Our system is based on a cross-industry standard of XML (extensible markup language) process definition language (XPDL). The core components of the system are a workflow editor for modeling clinical scenarios and a workflow engine for execution of those scenarios. We demonstrate, with an open-source and publicly available workflow suite, that clinical decision support logic can be executed on retrospective data. The same flowchart-based representation can also function in a prospective mode where the system can be integrated with an EHR system and respond to real-time clinical events. We limit the scope of our implementation to decision support content generation (which can be EHR system vendor independent). We do not focus on supporting complex decision support content delivery mechanisms due to lack of standardization of EHR systems in this area. We present results of our evaluation of the flowchart-based graphical notation as well as architectural evaluation of our implementation using an established evaluation framework for clinical decision support architecture. We describe an implementation of a free workflow technology software suite (available at http://code.google.com/p/healthflow) and its application in the domain of clinical decision support. Our implementation seamlessly supports clinical logic testing on retrospective data and offers a user-friendly knowledge representation paradigm. With the presented software implementation, we demonstrate that workflow engine technology can provide a decision support platform which evaluates well against an established clinical decision support architecture evaluation framework. Due to cross-industry usage of workflow engine technology, we can expect significant future functionality enhancements that will further improve the technology's capacity to serve as a clinical decision support platform.

Broadband seismic and acoustic observations of volcanic seismicity

NASA Astrophysics Data System (ADS)

Aster, R.; Lees, J.; Neuberg, J.

2000-08-01

It has been frequently noted (e.g. Aki, 1992) that volcanoes present some of the most difficult challenges in seismology due to a plethora of complex source and structural issues. The broadband seismo-acoustic study of active volcanoes is still in its adolescence, and the papers in this volume primarily describe first-order attempts to understand these signals and to build on a much longer history of short-period seismic observations and interpretations.

Isothermal Maxwell demon as a quantum ``sewing machine''

NASA Astrophysics Data System (ADS)

Čápek, V.

1998-04-01

A model of an open microscopic quantum system interacting with an isothermal bath and able to bind actively particles from a reservoir to their even excited bound states at the cost of the bath energy is presented. The binding (potentially important in, e.g., chain reactions-hence ``sewing'') is due to dynamic processes in a central part of the system accompanying the particle transfer. The outcome thus challenges the second law of thermodynamics.

Numerical assessment of wind turbine blade damage due to contact/impact with tower during installation

NASA Astrophysics Data System (ADS)

Shankar Verma, Amrit; Petter Vedvik, Nils; Gao, Zhen

2017-12-01

The use of floating crane vessel for installation of offshore wind turbine blades presents a great challenge in terms of its random motions and is likely to increase the probability of the blade hitting the preassembled tower during lifting operation. To evaluate the consequences of such scenarios and to determine the allowable motions or sea states for such operations, it is very important to understand the damage development in the blade due to impact. The present paper employs the application of high fidelity finite element method to investigate the damage behavior in the blade when the leading edge of the blade hits the tower. A nonlinear time domain structural analysis using ABAQUS was conducted on the DTU 10 MW reference blade model which is based on shell elements. Damage assessment along with the nature of evolution of various energies is examined and presented for two different impact velocities with modified layup stacking sequence at the contact region.

[Early congenital syphilis: a case report].

PubMed

Cavagnaro S M, Felipe; Pereira R, Teresita; Pérez P, Carla; Vargas Del V, Fernanda; Sandoval C, Carmen

2014-02-01

Congenital syphilis (CS) is a multisystemic infection of the newborn (NB) which can produce severe symptoms, and in some cases, even be fatal. In recent years, the incidence of syphilis has increased worldwide and similarly, the cases of CS in neonates have increased. To report two cases of early and severe presentation of CS, focusing on the importance of prevention of vertical transmission and monitoring of treated mothers. The diagnostic difficulties are discussed. Two premature newborns that were diagnosed with probable CS present in the newborn period are presented. In the first case, due to a high index of suspicion, but without confirmatory testing, treatment was started with good clinical response. In the second case, CS was confirmed through positive serology and the specific treatment was given. CS has significant diagnostic challenges as there is no test for early confirmation, therefore, a high index of suspicion might be key in the treatment and consequent prognosis. Due to the current epidemiology of the condition, it is also important to focus on preventive measures.

Small cell lung cancer with metastasis to the thyroid in a patient with toxic multinodular goiter.

PubMed

Ozgu, Eylem Sercan; Gen, Ramazan; Ilvan, Ahmet; Ozge, Cengiz; Polat, Ayşe; Vayisoglu, Yusuf

2012-11-01

Thyroid metastasis of lung cancer is rarely observed in clinical practice. The primary cancers which metastasize to the thyroid gland are mostly renal cell carcinoma, lung cancer, and breast cancer. Transient destructive thyrotoxicosis is caused by massive metastasis of extrathyroid tumors. We herein present a case report of a patient with small cell carcinoma of lung with metastasis to the thyroid and thyrotoxicosis due to toxic multinodular goiter. A 66-year-old man complained of swelling around the right side of the neck, dyspnea, progressive weight loss, and palpitation starting since 3 months before his admission. The patient was diagnosed with small cell carcinoma of lung with metastasis to the thyroid and thyrotoxicosis due to toxic multinodular goiter. The case report presented here illustrates the challenge of making a definitive and adequate diagnosis, particularly if the patient presents with 2 potential causes of thyrotoxicosis. Thyroid scintigraphy is an important tool for differential diagnosis of thyrotoxicosis.

Investigating Integration Capabilities Between Ifc and Citygml LOD3 for 3d City Modelling

NASA Astrophysics Data System (ADS)

Floros, G.; Pispidikis, I.; Dimopoulou, E.

2017-10-01

Smart cities are applied to an increasing number of application fields. This evolution though urges data collection and integration, hence major issues arise that need to be tackled. One of the most important challenges is the heterogeneity of collected data, especially if those data derive from different standards and vary in terms of geometry, topology and semantics. Another key challenge is the efficient analysis and visualization of spatial data, which due to the complexity of the physical reality in modern world, 2D GIS struggles to cope with. So, in order to facilitate data analysis and enhance the role of smart cities, the 3rd dimension needs to be implemented. Standards such as CityGML and IFC fulfill that necessity but they present major differences in their schemas that render their integration a challenging task. This paper focuses on addressing those differences, examining the up to date research work and investigates an alternative methodology in order to bridge the gap between those Standards. Within this framework, a generic IFC model is generated and converted to a CityGML Model, which is validated and evaluated on its geometrical correctness and semantical coherence. General results as well as future research considerations are presented.

Hittability: The Leader's Edge.

PubMed

Souba, Wiley

2017-04-01

Mastery of any discipline entails both the requisite skills and the ability to see things as "hittable." However, the concept of "hittability," which, in the context of leadership, refers to whether or not a specific leadership challenge shows up as hittable (or solvable) for those who are responsible for taking it on, is consistently overlooked. Nevertheless, it is a critical determinant of leadership effectiveness. Hittability is a function of the framing lenses-a person's beliefs, values, and worldviews-which frame the way a person "sees" a leadership challenge. Additionally, the future a person is "living into" is the framing lens for the present. In other words, a person's view of the future shapes his or her view of the present and his or her actions within it. Because the beliefs, values, and worldviews that constitute our framing lenses are constituted in and accessible through language (i.e., in the day-to-day stories, or narratives, a person tells him- or herself), reframing them to create a new future requires a new narrative. The ability to shift the previously unhittable to the hittable won't be, primarily, due to some newly acquired knowledge. Rather, it will be the result of reframing our challenges so they show up as hittable.

Improving Cognitive Skills of the Industrial Robot

NASA Astrophysics Data System (ADS)

Bezák, Pavol

2015-08-01

At present, there are plenty of industrial robots that are programmed to do the same repetitive task all the time. Industrial robots doing such kind of job are not able to understand whether the action is correct, effective or good. Object detection, manipulation and grasping is challenging due to the hand and object modeling uncertainties, unknown contact type and object stiffness properties. In this paper, the proposal of an intelligent humanoid hand object detection and grasping model is presented assuming that the object properties are known. The control is simulated in the Matlab Simulink/ SimMechanics, Neural Network Toolbox and Computer Vision System Toolbox.

Securing electronic health records with novel mobile encryption schemes.

PubMed

Weerasinghe, Dasun; Elmufti, Kalid; Rajarajan, Muttukrishnan; Rakocevic, Veselin

2007-01-01

Mobile devices have penetrated the healthcare sector due to their increased functionality, low cost, high reliability and easy-to-use nature. However, in healthcare applications the privacy and security of the transmitted information must be preserved. Therefore applications require a concrete security framework based on long-term security keys, such as the security key that can be found in a mobile Subscriber Identity Module (SIM). The wireless nature of communication links in mobile networks presents a major challenge in this respect. This paper presents a novel protocol that will send the information securely while including the access privileges to the authorized recipient.

Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology

NASA Technical Reports Server (NTRS)

Chamitoff, Gregory Errol

1992-01-01

Intelligent optimization methods are applied to the problem of real-time flight control for a class of airbreathing hypersonic vehicles (AHSV). The extreme flight conditions that will be encountered by single-stage-to-orbit vehicles, such as the National Aerospace Plane, present a tremendous challenge to the entire spectrum of aerospace technologies. Flight control for these vehicles is particularly difficult due to the combination of nonlinear dynamics, complex constraints, and parametric uncertainty. An approach that utilizes all available a priori and in-flight information to perform robust, real time, short-term trajectory planning is presented.

Radionuclide studies in coccidioidal meningitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corbus, H.F.; Lippert, R.G.; Radding, J.

1976-10-01

Although the uniformly fatal outcome in untreated meningitis due to Coccidioides immitis has been modified by amphotericin B, use of this drug presents a challenge to therapists striving to maximize its effectiveness and minimize its not inconsiderable toxicity. Many of the complications of intraventricular therapy, using an Ommaya reservoir, were encountered in a patient with coccidioidal meningitis, and this experience is reported to reemphasize the usefulness of radionuclide studies in guiding therapy and assessing the progress of the disease. The examples presented may be of interest to those faced with the difficult task of treating this still dangerous infection.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mace, Emily; Aalseth, Craig; Alexander, Tom

Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the isotope’s respective energy spectra. This activity makes direct dual-isotope measurements challenging without additional chemistry to concentrate the tritium in a sample. We present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120 mg of H2O and present sensitivity results.

Take the Reins on Model Quality with ModelCHECK and Gatekeeper

NASA Technical Reports Server (NTRS)

Jones, Corey

2012-01-01

Model quality and consistency has been an issue for us due to the diverse experience level and imaginative modeling techniques of our users. Fortunately, setting up ModelCHECK and Gatekeeper to enforce our best practices has helped greatly, but it wasn't easy. There were many challenges associated with setting up ModelCHECK and Gatekeeper including: limited documentation, restrictions within ModelCHECK, and resistance from end users. However, we consider ours a success story. In this presentation we will describe how we overcame these obstacles and present some of the details of how we configured them to work for us.

Quantifying intermolecular interactions of ionic liquids using cohesive energy densities.

PubMed

Lovelock, Kevin R J

2017-12-01

For ionic liquids (ILs), both the large number of possible cation + anion combinations and their ionic nature provide a unique challenge for understanding intermolecular interactions. Cohesive energy density, ced , is used to quantify the strength of intermolecular interactions for molecular liquids, and is determined using the enthalpy of vaporization. A critical analysis of the experimental challenges and data to obtain ced for ILs is provided. For ILs there are two methods to judge the strength of intermolecular interactions, due to the presence of multiple constituents in the vapour phase of ILs. Firstly, ced IP , where the ionic vapour constituent is neutral ion pairs, the major constituent of the IL vapour. Secondly, ced C+A , where the ionic vapour constituents are isolated ions. A ced IP dataset is presented for 64 ILs. For the first time an experimental ced C+A , a measure of the strength of the total intermolecular interaction for an IL, is presented. ced C+A is significantly larger for ILs than ced for most molecular liquids, reflecting the need to break all of the relatively strong electrostatic interactions present in ILs. However, the van der Waals interactions contribute significantly to IL volatility due to the very strong electrostatic interaction in the neutral ion pair ionic vapour. An excellent linear correlation is found between ced IP and the inverse of the molecular volume. A good linear correlation is found between IL ced IP and IL Gordon parameter (which are dependent primarily on surface tension). ced values obtained through indirect methods gave similar magnitude values to ced IP . These findings show that ced IP is very important for understanding IL intermolecular interactions, in spite of ced IP not being a measure of the total intermolecular interactions of an IL. In the outlook section, remaining challenges for understanding IL intermolecular interactions are outlined.

Quantifying intermolecular interactions of ionic liquids using cohesive energy densities

PubMed Central

2017-01-01

For ionic liquids (ILs), both the large number of possible cation + anion combinations and their ionic nature provide a unique challenge for understanding intermolecular interactions. Cohesive energy density, ced, is used to quantify the strength of intermolecular interactions for molecular liquids, and is determined using the enthalpy of vaporization. A critical analysis of the experimental challenges and data to obtain ced for ILs is provided. For ILs there are two methods to judge the strength of intermolecular interactions, due to the presence of multiple constituents in the vapour phase of ILs. Firstly, cedIP, where the ionic vapour constituent is neutral ion pairs, the major constituent of the IL vapour. Secondly, cedC+A, where the ionic vapour constituents are isolated ions. A cedIP dataset is presented for 64 ILs. For the first time an experimental cedC+A, a measure of the strength of the total intermolecular interaction for an IL, is presented. cedC+A is significantly larger for ILs than ced for most molecular liquids, reflecting the need to break all of the relatively strong electrostatic interactions present in ILs. However, the van der Waals interactions contribute significantly to IL volatility due to the very strong electrostatic interaction in the neutral ion pair ionic vapour. An excellent linear correlation is found between cedIP and the inverse of the molecular volume. A good linear correlation is found between IL cedIP and IL Gordon parameter (which are dependent primarily on surface tension). ced values obtained through indirect methods gave similar magnitude values to cedIP. These findings show that cedIP is very important for understanding IL intermolecular interactions, in spite of cedIP not being a measure of the total intermolecular interactions of an IL. In the outlook section, remaining challenges for understanding IL intermolecular interactions are outlined. PMID:29308254

Geriatric gambling disorder: challenges in clinical assessment.

PubMed

Smith, Mara; Hategan, Ana; Bourgeois, James A

2017-12-01

To the Editor: The gaming industry is growing rapidly, as is the proportion of older adults aged 65 years or older who participate in gambling (Tse et al., 2012). With casinos tailoring their venues and providing incentives to attract older adults, and with the increasing popularity of "pleasure trips" to casinos organized by retirement homes, plus active promotion of government-operated lotteries in many countries, this trend is likely to continue. Gambling disorder (GD) or "pathological" or "problem" gambling presents a public health concern in the geriatric population. However, ascertainment of its prevalence and diagnostic accuracy have proven challenging. This is largely due to the absence of diagnostic criteria specific to the geriatric age and rating scales validated for use in this population.

Redundant Calibration: breaking the constraints of limited sky information

NASA Astrophysics Data System (ADS)

Joseph, Ronniy C.

2018-05-01

The latest generation of low frequency radio interferometers, e.g. LOFAR, MWA, PAPER, has been pushing down the detection limits on the hydrogen signal from the Epoch of Reionisation. However, due to the challenges posed by foregrounds and instrumental systematics the signal has eluded detection thus far. To overcome these challenges we require a detailed understanding of the calibration of these relatively new telescopes. This led to a renewed interest in redundant calibration. Classical calibration schemes depend on sky models based on limited knowledge of the low frequency sky. Redundant calibration, however, allows us to escape our ignorance as it is sky model independent. We will review the field of redundant calibration, and present work we have undertaken to understand the limitations of this calibration method.

HSPF Modeling for Compliance and Enforcement: An Urban Case Study

NASA Astrophysics Data System (ADS)

Marshalonis, D.

2017-12-01

Stormwater runoff is one of the most significant challenges to water quality facing surface waters globally. In the United States, the Environmental Protection Agency (EPA) regulates stormwater flows through its National Pollutant Discharge Elimination System (NPDES) program permits. When egregious violations occur, EPA may develop its case and prove those violations through the legal dispute process. However, evidence in stormwater-related cases is ephemeral, difficult to collect due to unpredictable weather dynamics, and there are usually no witnesses. The work presented here illustrates an approach EPA takes for certain wet weather cases: introduce results from hydrologic and hydraulic models as evidence to meet legal burden of proof standards. The challenges and opportunities of using models in stormwater discharge modeling are highlighted.

A Brief Review on Multivalent Intercalation Batteries with Aqueous Electrolytes

PubMed Central

Guduru, Ramesh K.; Icaza, Juan C.

2016-01-01

Rapidly growing global demand for high energy density rechargeable batteries has driven the research toward developing new chemistries and battery systems beyond Li-ion batteries. Due to the advantages of delivering more than one electron and giving more charge capacity, the multivalent systems have gained considerable attention. At the same time, affordability, ease of fabrication and safety aspects have also directed researchers to focus on aqueous electrolyte based multivalent intercalation batteries. There have been a decent number of publications disclosing capabilities and challenges of several multivalent battery systems in aqueous electrolytes, and while considering an increasing interest in this area, here, we present a brief overview of their recent progress, including electrode chemistries, functionalities and challenges. PMID:28344298

Heatshield for Extreme Entry Environment Technology (HEEET)

NASA Technical Reports Server (NTRS)

Venkatapathy, E.; Ellerby, D.; Stackpoole, M..; Peterson, K.; Gage, P.; Beerman, A.; Blosser, M.; Chinnapongse, R.; Dillman, R.; Feldman, J.;

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, R.A.; Hines, T.L.

Utilization of remote gas resources in developing countries continues to offer challenges and opportunities to producers and contractors. The Aguaytia Gas and Power Project is an example where perseverance and creativity resulted in successful utilization of natural gas resources in the Ucayali Region of Central Peru, a country which previously had no natural gas infrastructure. The resource for the project was first discovered by Mobil in 1961, and remained undeveloped for over thirty years due to lack of infrastructure and markets. Maple Gas won a competitively bid contract to develop the Aguaytia gas reserves in March of 1993. The challengesmore » facing Maple Gas were to develop downstream markets for the gas, execute contracts with Perupetro S.A. and other Peruvian government entities, raise financing for the project, and solicit and execute engineering procurement and construction (EPC) contracts for the execution of the project. The key to development of the downstream markets was the decision to generate electric power and transmit the power over the Andes to the main electrical grid along the coast of Peru. Supplemental revenue could be generated by gas sales to a small regional power plant and extraction of LPG and natural gasoline for consumption in the Peruvian market. Three separate lump sum contracts were awarded to Asea Brown Boveri (ABB) companies for the gas project, power project and transmission project. Each project presented its unique challenges, but the commonalities were the accelerated schedule, high rainfall in a prolonged wet season and severe logistics due to lack of infrastructure in the remote region. This presentation focuses on how the gas plant contractor, ABB Randall, working in harmony with the developer, Maple Gas, tackled the challenges to monetize a remote gas resource.« less

Hydrogen-related challenges for the steelmaker: the search for proper testing

NASA Astrophysics Data System (ADS)

Thiessen, R. G.

2017-06-01

The modern steelmaker of advanced high-strength steels has always been challenged with the conflicting targets of increased strength while maintaining or improving ductility. These new steels help the transportation sector, including the automotive sector, to achieve the goals of increased passenger safety and reduced emissions. With increasing tensile strengths, certain steels exhibit an increased sensitivity towards hydrogen embrittlement (HE). The ability to characterize the material's sensitivity in an as-delivered condition has been developed and accepted (SEP1970), but the complexity of the stress states that can induce an embrittlement together with the wide range of applications for high-strength steels make the development of a standardized test for HE under in-service conditions extremely challenging. Some proposals for evaluating the material's sensitivity give an advantage to materials with a low starting ductility. Despite this, newly developed materials can have a higher original elongation with only a moderate reduction in elongation due to hydrogen. This work presents a characterization of new materials and their sensitivity towards HE. This article is part of the themed issue 'The challenges of hydrogen and metals'.

Analysis of velocity and magnetic field fluctuations from simulated Solar Probe Plus measurements: Interpretation and predictions.

NASA Astrophysics Data System (ADS)

Perez, J. C.; Chandran, B. D. G.

2016-12-01

As Solar Probe Plus (SPP) explores the near-Sun environment, our ability to obtain meaningful interpretation of in-situ measurements faces two significant challenges. The first challenge is that the Taylor Hypothesis (TH), which is normally used in the interpretation of existing spacecraft data, breaks down at the low heliocentric distances that SPP mission will explore. The second challenge is our limited understanding of turbulence in this region, largely due to the theoretical and numerical difficulties in modeling this problem. In this work we present recent progress towards overcoming these challenges using high-resolution numerical simulations of Alfvenic turbulence in the inner heliosphere. We fly virtual SPP spacecraft in the simulation domain to obtain single-point measurements of the velocity and magnetic field fluctuations at several radial locations relevant to SPP. We use these virtual measurements to 1) validate a recently introduced modified TH that allows one to recover the spatial structure of the dominant (outward-propagating) Alfvenic fluctuations, of the kind SPP will encounter; and 2) to compare these virtual observations with our most recent phenomenological models of reflection-driven Alfven turbulence.

Hydrogen-related challenges for the steelmaker: the search for proper testing.

PubMed

Thiessen, R G

2017-07-28

The modern steelmaker of advanced high-strength steels has always been challenged with the conflicting targets of increased strength while maintaining or improving ductility. These new steels help the transportation sector, including the automotive sector, to achieve the goals of increased passenger safety and reduced emissions. With increasing tensile strengths, certain steels exhibit an increased sensitivity towards hydrogen embrittlement (HE). The ability to characterize the material's sensitivity in an as-delivered condition has been developed and accepted (SEP1970), but the complexity of the stress states that can induce an embrittlement together with the wide range of applications for high-strength steels make the development of a standardized test for HE under in-service conditions extremely challenging. Some proposals for evaluating the material's sensitivity give an advantage to materials with a low starting ductility. Despite this, newly developed materials can have a higher original elongation with only a moderate reduction in elongation due to hydrogen. This work presents a characterization of new materials and their sensitivity towards HE.This article is part of the themed issue 'The challenges of hydrogen and metals'. © 2017 The Author(s).

Adaptive Pathways: Possible Next Steps for Payers in Preparation for Their Potential Implementation

PubMed Central

Vella Bonanno, Patricia; Ermisch, Michael; Godman, Brian; Martin, Antony P.; Van Den Bergh, Jesper; Bezmelnitsyna, Liudmila; Bucsics, Anna; Arickx, Francis; Bybau, Alexander; Bochenek, Tomasz; van de Casteele, Marc; Diogene, Eduardo; Eriksson, Irene; Fürst, Jurij; Gad, Mohamed; Greičiūtė-Kuprijanov, Ieva; van der Graaff, Martin; Gulbinovic, Jolanta; Jones, Jan; Joppi, Roberta; Kalaba, Marija; Laius, Ott; Langner, Irene; Mardare, Ileana; Markovic-Pekovic, Vanda; Magnusson, Einar; Melien, Oyvind; Meshkov, Dmitry O.; Petrova, Guenka I.; Selke, Gisbert; Sermet, Catherine; Simoens, Steven; Schuurman, Ad; Ramos, Ricardo; Rodrigues, Jorge; Zara, Corinne; Zebedin-Brandl, Eva; Haycox, Alan

2017-01-01

Medicines receiving a conditional marketing authorization through Medicines Adaptive Pathways to Patients (MAPPs) will be a challenge for payers. The “introduction” of MAPPs is already seen by the European Medicines Agency (EMA) as a fait accompli, with payers not consulted or involved. However, once medicines are approved through MAPPs, they will be evaluated for funding by payers through different activities. These include Health Technology Assessment (HTA) with often immature clinical data and high uncertainty, financial considerations, and negotiations through different types of agreements, which can require monitoring post launch. Payers have experience with new medicines approved through conditional approval, and the fact that MAPPs present additional challenges is a concern from their perspective. There may be some activities where payers can collaborate. The final decisions on whether to reimburse a new medicine via MAPPs will have more variation than for medicines licensed via conventional processes. This is due not only to increasing uncertainty associated with medicines authorized through MAPPs but also differences in legal frameworks between member states. Moreover, if the financial and side-effect burden from the period of conditional approval until granting full marketing authorization is shifted to the post-authorization phase, payers may have to bear such burdens. Collection of robust data during routine clinical use is challenging along with high prices for new medicines during data collection. This paper presents the concept of MAPPs and possible challenges. Concerns and potential ways forward are discussed and a number of recommendations are presented from the perspective of payers. PMID:28878667

Appdaptivity: An Internet of Things Device-Decoupled System for Portable Applications in Changing Contexts

PubMed Central

Díaz, Manuel; Rubio, Bartolomé; Van den Abeele, Floris

2018-01-01

Currently, applications in the Internet of Things (IoT) are tightly coupled to the underlying physical devices. As a consequence, upon adding a device, device replacement or user’s relocation to a different physical space, application developers have to re-perform installation and configuration processes to reconfigure applications, which bears costs in time and knowledge of low-level details. In the emerging IoT field, this issue is even more challenging due to its current unpredictable growth in term of applications and connected devices. In addition, IoT applications can be personalised to each end user and can be present in different environments. As a result, IoT scenarios are very changeable, presenting a challenge for IoT applications. In this paper we present Appdaptivity, a system that enables the development of portable device-decoupled applications that can be adapted to changing contexts. Through Appdaptivity, application developers can intuitively create portable and personalised applications, disengaging from the underlying physical infrastructure. Results confirms a good scalability of the system in terms of connected users and components involved. PMID:29701698

Appdaptivity: An Internet of Things Device-Decoupled System for Portable Applications in Changing Contexts.

PubMed

Martín, Cristian; Hoebeke, Jeroen; Rossey, Jen; Díaz, Manuel; Rubio, Bartolomé; Van den Abeele, Floris

2018-04-26

Currently, applications in the Internet of Things (IoT) are tightly coupled to the underlying physical devices. As a consequence, upon adding a device, device replacement or user’s relocation to a different physical space, application developers have to re-perform installation and configuration processes to reconfigure applications, which bears costs in time and knowledge of low-level details. In the emerging IoT field, this issue is even more challenging due to its current unpredictable growth in term of applications and connected devices. In addition, IoT applications can be personalised to each end user and can be present in different environments. As a result, IoT scenarios are very changeable, presenting a challenge for IoT applications. In this paper we present Appdaptivity, a system that enables the development of portable device-decoupled applications that can be adapted to changing contexts. Through Appdaptivity, application developers can intuitively create portable and personalised applications, disengaging from the underlying physical infrastructure. Results confirms a good scalability of the system in terms of connected users and components involved.

Incidence and prevalence of pregnancy-related heart disease.

PubMed

Sliwa, Karen; Böhm, Michael

2014-03-15

Worldwide, the numbers of women who have a pre-existing cardiovascular disease or develop cardiac problems during pregnancy are increasing and, due to the lack of evidenced-based data, this provides challenges for the treating physician. Cardiovascular disease in pregnancy is a complex topic as women can present either pre- or post-partum, due to a pre-existing heart disease such as operated on or unoperated on congenital heart disease, valvular heart disease, chronic hypertension, or familial dilated cardiomyopathy. Women often present with symptoms and signs of acute heart failure. On the other hand, there are diseases which are directly related to pregnancy, such as hypertensive disorders of pregnancy and peripartum cardiomyopathy, or where pregnancy increases risk of a disease as, for example, the risk of myocardial infarction. These diseases can have long-term implications to the life of the affected women and their families. There is, in particular, a paucity of data from developing countries of this unique disease pattern and its presentations. This review summarizes the current knowledge of the incidence and prevalence of pregnancy-related cardiovascular disease in women presenting pre- or post-partum.

Management of a patient with autism following ingestion of a foreign body.

PubMed

McCain, Stephen; Tan, Samantha; Mark, David

2014-06-25

Patients with autism often find admission to hospital an anxious time. Awareness of the condition, a speedy diagnosis and flexibility in adapting treatment plans will facilitate early discharge and return to their familiar environment. We describe a patient with severe autism who presented with an acute abdomen secondary to ingestion of a foreign body which required laparotomy. Communication directly to medical staff was greatly limited due to severe autism and close liaison with family members was essential in interpreting scant clinical signs. At the time of surgery a rubber bottle teat was found causing transection of small bowel due to erosion of the foreign body. The postoperative course was fraught with challenges and ensuring side room nursing care with family members present throughout his admission minimised postoperative stress and confusion. We recommend awareness of management strategies for patients with autism to ensure rapid recovery and early discharge home. 2014 BMJ Publishing Group Ltd.

A Bayesian Measurment Error Model for Misaligned Radiographic Data

DOE PAGES

Lennox, Kristin P.; Glascoe, Lee G.

2013-09-06

An understanding of the inherent variability in micro-computed tomography (micro-CT) data is essential to tasks such as statistical process control and the validation of radiographic simulation tools. The data present unique challenges to variability analysis due to the relatively low resolution of radiographs, and also due to minor variations from run to run which can result in misalignment or magnification changes between repeated measurements of a sample. Positioning changes artificially inflate the variability of the data in ways that mask true physical phenomena. We present a novel Bayesian nonparametric regression model that incorporates both additive and multiplicative measurement error inmore » addition to heteroscedasticity to address this problem. We also use this model to assess the effects of sample thickness and sample position on measurement variability for an aluminum specimen. Supplementary materials for this article are available online.« less

Acoustic Localization with Infrasonic Signals

NASA Astrophysics Data System (ADS)

Threatt, Arnesha; Elbing, Brian

2015-11-01

Numerous geophysical and anthropogenic events emit infrasonic frequencies (<20 Hz), including volcanoes, hurricanes, wind turbines and tornadoes. These sounds, which cannot be heard by the human ear, can be detected from large distances (in excess of 100 miles) due to low frequency acoustic signals having a very low decay rate in the atmosphere. Thus infrasound could be used for long-range, passive monitoring and detection of these events. An array of microphones separated by known distances can be used to locate a given source, which is known as acoustic localization. However, acoustic localization with infrasound is particularly challenging due to contamination from other signals, sensitivity to wind noise and producing a trusted source for system development. The objective of the current work is to create an infrasonic source using a propane torch wand or a subwoofer and locate the source using multiple infrasonic microphones. This presentation will present preliminary results from various microphone configurations used to locate the source.

Unruptured Aneurysm of Sinus of Valsalva Coexisting with the Large Ventricular Septal Defect and Severe Aortic Regurgitation in a Young Man

PubMed Central

Nezafati, Pouya; Nezafati, Mohammad Hassan; Hoseinikhah, Hamid

2015-01-01

Introduction. Unruptured sinus of valsalva aneurysm (SVA) is a rare congenital anomaly, particularly, when it coexists with a ventricular septal defect (VSD) and aortic regurgitation due to the prolapse of the elongated aortic cusp into the VSD. In this report, we present the case of a 19-year-old young man with VSD challenging in spite of dyspnea and lower limb edema. Presentation of Case. Its diagnosis was made on the basis of transthoracic echocardiography results. Surgical management consisted of replacing the SVA with mechanical valve prosthesis. A Gore-Tex patch repaired the VSD. Discussion. In the follow-up periods, clinical and echocardiographic tests showed that the patient was in excellent status. Conclusion. SVA requires a surgical procedure due to its high risk of mortality in unoperated patients and a good safety of surgery. PMID:26236342

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kazyak, Eric; Chen, Kuan-Hung; Wood, Kevin N.

Lithium solid electrolytes are a promising platform for achieving high energy density, long-lasting, and safe rechargeable batteries, which could have widespread societal impact. In particular, the ceramic oxide garnet Li7La3Zr2O12 (LLZO) has been shown to be a promising electrolyte due to its stability and high ionic conductivity. Two major challenges for commercialization are manufacturing of thin layers and creating stable, low-impedance, interfaces with both anode and cathode materials. Atomic Layer Deposition (ALD) has recently been shown as a potential method for depositing both solid electrolytes and interfacial layers to improve the stability and performance at electrode-electrolyte interfaces in battery systems.more » Herein we present the first reported ALD process for LLZO, demonstrating the ability to tune composition within the amorphous film and anneal to achieve the desired cubic garnet phase. Formation of the cubic phase was observed at temperatures as low as 555°C, significantly lower than is required for bulk processing. Additionally, challenges associated with achieving a dense garnet phase due to substrate reactivity, morphology changes and Li loss under the necessary high temperature annealing are quantified via in situ synchrotron diffraction.« less

Diagnosis of pheochromocytoma in the setting of Parkinson disease.

PubMed

Mehta, Shyamal H; Prakash, Rajan; Prisant, L Michael; Isales, Carlos M; Morgan, John C; Williams, Hadyn; Sethi, Kapil D

2009-06-01

A 59-year-old man with a 7-year history of Parkinson disease (PD) presented with episodes of sudden, severe headaches with neck pain, tachycardia, sweating and pallor. During these episodes, the patient showed marked elevations in blood pressure, regardless of posture. This was unusual, given that he had no prior history of hypertension. The array of symptoms raised suspicions of pheochromocytoma, but diagnosis was challenging, as the standard diagnostic biochemical tests were confounded by dopaminergic medications. Further work-up revealed left adrenal medullary hyperplasia. Several reports exist of pseudopheochromocytoma in patients on dopaminergic therapy, but this is the first documented case of pheochromocytoma syndrome due to adrenal medullary hyperplasia in a patient with PD. This case highlights the challenges of performing a diagnostic work-up in a PD patient with symptoms suggestive of pheochromocytoma, and illustrates the utility of (123)I-metaiodobenzylguanidine ((123)I-MIBG) single-photon emission CT in making a diagnosis.Investigations. Physical examination, laboratory tests, abdominal MRI scan, abdominal (123)I-MIBG scan, abdominal (18)F-fluorodeoxyglucose PET scan. Pheochromocytoma syndrome due to adrenal medullary hyperplasia.Management. Surgical excision of the left adrenal gland.

Using Field-Particle Correlations to Diagnose the Collisionless Damping of Plasma Turbulence

NASA Astrophysics Data System (ADS)

Howes, Gregory; Klein, Kristropher

2016-10-01

Plasma turbulence occurs ubiquitously throughout the heliosphere, yet our understanding of how turbulence governs energy transport and plasma heating remains incomplete, constituting a grand challenge problem in heliophysics. In weakly collisional heliospheric plasmas, such as the solar corona and solar wind, damping of the turbulent fluctuations occurs due to collisionless interactions between the electromagnetic fields and the individual plasma particles. A particular challenge in diagnosing this energy transfer is that spacecraft measurements are typically limited to a single point in space. Here we present an innovative field-particle correlation technique that can be used with single-point measurements to estimate the energization of the plasma particles due to the damping of the electromagnetic fields, providing vital new information about this how energy transfer is distributed as a function of particle velocity. This technique has the promise to transform our ability to diagnose the kinetic plasma physical mechanisms responsible for not only the damping of turbulence, but also the energy conversion in both collisionless magnetic reconnection and particle acceleration. The work has been supported by NSF CAREER Award AGS-1054061, NSF AGS-1331355, and DOE DE-SC0014599.

Probing compressed mass spectra in electroweak supersymmetry with Recursive Jigsaw Reconstruction

NASA Astrophysics Data System (ADS)

Santoni, M.

2018-05-01

The lack of evidence for the production of colored supersymmetric particles at the LHC has increased interest in searches for superpartners of the electroweak SM gauge bosons, namely the neutralinos and charginos. These are challenging due to the weak nature of the production process, and the existing discovery reach has significant gaps in due to the difficulty of separating the supersymmetric signal from SM diboson events that produce similar final states and kinematics. We apply the Recursive Jigsaw Reconstruction technique to study final states enriched in charged leptons and missing transverse momentum, focusing on compressed topologies with direct production of charginos and neutralinos decaying to the lightest neutral supersymmetric particle through the emission of W and Z bosons. After presenting prototype analysis designs for future LHC runs, we demonstrate that its detectors have the potential to probe a significant amount of unexplored parameter space for chargino-neutralino associated production within the next few years, and show that the very challenging successful search for chargino pair production with compressed spectra might be possible by the end of the LHC lifetime.

Quality, Safety and Patient Centered Care--A Dream Come True in the Mountains of Northern Pakistan. An Award winning project of "2015 Quality, Safety & Patient Centered Care Award" at, Chicago USA.

PubMed

Jassani, Kashif; Essani, Rozina Roshan; Abbas, Syed Nadeem Husain

2016-01-01

Northern Pakistan remains very challenging terrain due to harsh weather all year round presenting an infrastructura, human resource and supply chain challenge of its own. Many times the facility had to move to different locations on emergency and ad hoc basis due to landslides, earthquakes affecting continuity of care. Providing quality healthcare to often resource constraint hard-to-reach areas has always been AKHS,P's unique forte. Breaking barriers for catchment population to access quality healthcare, AKHS,P embarked on an initiative of implementing, achieving and sustaining ISO 9001:2008 Quality Management System international standards certification. This article shares the unique experience of AKHS,P in achieving and sustaining ISO 9001:2008 International Quality Management System Certification. After untiring efforts and the hard work of ground staff; AKHS,P achieved ISO 9001:2008 International Quality Management System Certification as well as 1st Surveillance Audit which itself proved that AKHS,P sustained quality systems and ensured continuous quality improvement in the Mountains of Northern Pakistan.

Application of digital image correlation for long-distance bridge deflection measurement

NASA Astrophysics Data System (ADS)

Tian, Long; Pan, Bing; Cai, Youfa; Liang, Hui; Zhao, Yan

2013-06-01

Due to its advantages of non-contact, full-field and high-resolution measurement, digital image correlation (DIC) method has gained wide acceptance and found numerous applications in the field of experimental mechanics. In this paper, the application of DIC for real-time long-distance bridge deflection detection in outdoor environments is studied. Bridge deflection measurement using DIC in outdoor environments is more challenging than regular DIC measurements performed under laboratory conditions. First, much more image noise due to variations in ambient light will be presented in the images recorded in outdoor environments. Second, how to select the target area becomes a key factor because long-distance imaging results in a large field of view of the test object. Finally, the image acquisition speed of the camera must be high enough (larger than 100 fps) to capture the real-time dynamic motion of a bridge. In this work, the above challenging issues are addressed and several improvements were made to DIC method. The applicability was demonstrated by real experiments. Experimental results indicate that the DIC method has great potentials in motion measurement in various large building structures.

Polycythemia vera presenting as acute myocardial infarction: An unusual presentation

PubMed Central

Bahbahani, Hussain; Aljenaee, Khaled; Bella, Abdelhaleem

2014-01-01

Acute myocardial infarction (AMI) is usually seen in the setting of atherosclerosis and its associated risk factors. Myocardial infarction in the young poses a particular challenge, as the disease is less likely, due to atherosclerosis. We report the case of a 37-year-old female patient who presented with ST segment elevation anterolateral AMI. The only abnormality on routine blood investigation was raised hemoglobin and hematocrit. After further testing, she was diagnosed according to the World Health Organization (WHO) criteria with polycythemia vera. This case illustrates the importance of recognizing polycythemia vera as an important cause of thrombosis, which can present initially as AMI, and to emphasize the early recognition of the disease in order to initiate appropriate management strategies. PMID:25544823

Recent Advances of Rare-Earth Ion Doped Luminescent Nanomaterials in Perovskite Solar Cells.

PubMed

Qiao, Yu; Li, Shuhan; Liu, Wenhui; Ran, Meiqing; Lu, Haifei; Yang, Yingping

2018-01-15

Organic-inorganic lead halide based perovskite solar cells have received broad interest due to their merits of low fabrication cost, a low temperature solution process, and high energy conversion efficiencies. Rare-earth (RE) ion doped nanomaterials can be used in perovskite solar cells to expand the range of absorption spectra and improve the stability due to its upconversion and downconversion effect. This article reviews recent progress in using RE-ion-doped nanomaterials in mesoporous electrodes, perovskite active layers, and as an external function layer of perovskite solar cells. Finally, we discuss the challenges facing the effective use of RE-ion-doped nanomaterials in perovskite solar cells and present some prospects for future research.

Extreme-scale Algorithms and Solver Resilience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dongarra, Jack

A widening gap exists between the peak performance of high-performance computers and the performance achieved by complex applications running on these platforms. Over the next decade, extreme-scale systems will present major new challenges to algorithm development that could amplify this mismatch in such a way that it prevents the productive use of future DOE Leadership computers due to the following; Extreme levels of parallelism due to multicore processors; An increase in system fault rates requiring algorithms to be resilient beyond just checkpoint/restart; Complex memory hierarchies and costly data movement in both energy and performance; Heterogeneous system architectures (mixing CPUs, GPUs,more » etc.); and Conflicting goals of performance, resilience, and power requirements.« less

Three-Dimensional Printing of Prosthetic Hands for Children.

PubMed

Burn, Matthew B; Ta, Anderson; Gogola, Gloria R

2016-05-01

Children with hand reductions, whether congenital or traumatic, have unique prosthetic needs. They present a challenge because of their continually changing size due to physical growth as well as changing needs due to psychosocial development. Conventional prosthetics are becoming more technologically advanced and increasingly complex. Although these are welcome advances for adults, the concomitant increases in weight, moving parts, and cost are not beneficial for children. Pediatric prosthetic needs may be better met with simpler solutions. Three-dimensional printing can be used to fabricate rugged, light-weight, easily replaceable, and very low cost assistive hands for children. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Computational modeling of electromechanical instabilities in dielectric elastomers (Conference Presentation)

NASA Astrophysics Data System (ADS)

Park, Harold

2016-04-01

Dielectric elastomers are a class of soft, active materials that have recently gained significant interest due to the fact that they can be electrostatically actuated into undergoing extremely large deformations. An ongoing challenge has been the development of robust and accurate computational models for elastomers, particularly those that can capture electromechanical instabilities that limit the performance of elastomers such as creasing, wrinkling, and snap-through. I discuss in this work a recently developed finite element model for elastomers that is dynamic, nonlinear, and fully electromechanically coupled. The model also significantly alleviates volumetric locking due that arises due to the incompressible nature of the elastomers, and incorporates viscoelasticity within a finite deformation framework. Numerical examples are shown that demonstrate the performance of the proposed method in capturing electromechanical instabilities (snap-through, creasing, cratering, wrinkling) that have been observed experimentally.

Atypical Presentations of Tularemia.

PubMed

Odegaard, Karah; Boersma, Beth; Keegan, James

2017-05-01

Francisella tularensis is a gram-negative coccobacillus that causes a condition commonly referred to as tularemia. There has been a dramatic increase in tularemia cases reported in South Dakota, many of which were challenging to diagnose due to atypical clinical manifestations. We describe an interesting case of pneumonic tularemia and summarize six similar cases, several of which presented with lung nodules suggestive of malignancy. According to the literature, this is only the third outbreak of pneumonic tularemia reported in the U.S. We believe it is important for clinicians to be aware of the increased incidence of tularemia in the area and to be vigilant in the diagnosis and management of these atypically presenting cases. Copyright© South Dakota State Medical Association.

Contrasting Perspectives Of Junior versus Senior NASA ISS Flight Controllers On Leadership And Cultural Issues

NASA Technical Reports Server (NTRS)

Clement, James L.; Boyd, J. E.; Saylor, S.; Kanas, N.

2007-01-01

NASA flight controllers have always worked in a very demanding environment, but the International Space Station (ISS) poses even more challenges than prior missions. A recent NASA/Ames survey by Parke and Orasanu of NASA/Johnson flight controllers uncovered concerns about communications problems between American personnel and their international counterparts. To better understand these problems, we interviewed 14 senior and 12 junior ISS flight controllers at NASA/Johnson about leadership and cultural challenges they face and strategies for addressing these challenges. The qualitative interview data were coded and tabulated. Here we present quantitative analyses testing for differences between junior and senior controllers. Based on nonparametric statistical tests comparing responses across groups, the senior controllers were significantly more aware of the impact of working in dispersed teams, the context of constant change, and the upcoming multilateral challenges, while junior controllers were more aware of language and cultural issues. We consider our findings in light of other studies of controllers and other known differences between senior and junior controllers. For example, the fact that senior controllers had their formative early experience controlling pre-ISS short-duration Shuttle missions seems to have both positive and negative aspects, which are supported by our data. Our findings may also reflect gender differences, but we cannot unconfound this effect in our data because all the senior respondents were males. Many of the junior-senior differences are not only due to elapsed time on the job, but also due to a cohort effect. The findings of this study should be used for training curricula tailored differently for junior and senior controllers.

Challenges in pediatric chronic inflammatory demyelinating polyneuropathy.

PubMed

Haliloğlu, Göknur; Yüksel, Deniz; Temoçin, Cağri Mesut; Topaloğlu, Haluk

2016-12-01

Chronic inflammatory demyelinating neuropathy, a treatable immune-mediated disease of the peripheral nervous system is less common in childhood compared to adults. Despite different sets of diagnostic criteria, lack of a reliable biologic marker leads to challenges in diagnosis, follow-up and treatment. Our first aim was to review clinical presentation, course, response to treatment, and prognosis in our childhood patients. We also aimed to document diagnostic and therapeutic pitfalls and challenges at the bedside. Our original cohort consisted of 23 pediatric patients who were referred to us with a clinical diagnosis of chronic inflammatory demyelinating neuropathy. Seven patients reaching to an alternative diagnosis were excluded. In the remaining patients, diagnostic, treatment and follow-up data were compared in typical patients who satisfied both clinical and electrodiagnostic criteria and atypical patients who failed to meet minimal research chronic inflammatory demyelinating neuropathy electrodiagnostic requirements. Eight of 16 patients (50%) met the minimal chronic inflammatory demyelinating neuropathy research diagnostic requirements. There was only a statistically significant difference (p = 0.010) in terms of European Neuromuscular Centre childhood chronic inflammatory diagnostic mandatory clinical criteria between the two groups. Misdiagnosis due to errors in electrophysiological interpretation (100%, n = 8), cerebrospinal fluid cytoalbuminologic dissociation (100%, n = 4 and/or subjective improvement on any immunotherapy modality (80 ± 19.27%)) was frequent. Pediatric CIDP is challenging in terms of diagnostic and therapeutic pitfalls at the bedside. Diagnostic errors due to electrophysiological interpretation, cerebrospinal fluid cytoalbuminologic dissociation, and/or subjective improvement on immunotherapy should be considered. Copyright © 2016 Elsevier B.V. All rights reserved.

Perampanel and Challenging Behaviour in Intellectual Disability and Epilepsy: A Management Dilemma

PubMed Central

Choudry, Ansar

2014-01-01

We describe a case of a patient with a diagnosis of moderate learning disability with challenging behaviour and treatment refractory epilepsy. Antiepileptics can increase challenging behaviour; however, antipsychotics can provoke seizures. This results in a difficult balance for patient care. Due to worsening seizures, the patient was prescribed perampanel. This increased her aggression and agitation resulting in admission. We trialled four antipsychotic drugs to reduce her challenging behaviour, two of which worsened her seizures. It was necessary to continue antiepileptic medication to maintain adequate seizure control. However, the resulting uncontrolled challenging behaviour persisted, meaning she was unable to return to her family home on discharge. This case emphasises the difficult scenario clinician's encounter when balancing the use of antipsychotics and antiepileptics. The case demonstrates the significant functional loss due to challenging behaviour, balanced against controlling life threatening seizures. PMID:25580340

Stress Analysis of Bolted, Segmented Cylindrical Shells Exhibiting Flange Mating-Surface Waviness

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

2009-01-01

Bolted, segmented cylindrical shells are a common structural component in many engineering systems especially for aerospace launch vehicles. Segmented shells are often needed due to limitations of manufacturing capabilities or transportation issues related to very long, large-diameter cylindrical shells. These cylindrical shells typically have a flange or ring welded to opposite ends so that shell segments can be mated together and bolted to form a larger structural system. As the diameter of these shells increases, maintaining strict fabrication tolerances for the flanges to be flat and parallel on a welded structure is an extreme challenge. Local fit-up stresses develop in the structure due to flange mating-surface mismatch (flange waviness). These local stresses need to be considered when predicting a critical initial flaw size. Flange waviness is one contributor to the fit-up stress state. The present paper describes the modeling and analysis effort to simulate fit-up stresses due to flange waviness in a typical bolted, segmented cylindrical shell. Results from parametric studies are presented for various flange mating-surface waviness distributions and amplitudes.

Buildings Lean Maintenance Implementation Model

NASA Astrophysics Data System (ADS)

Abreu, Antonio; Calado, João; Requeijo, José

2016-11-01

Nowadays, companies in global markets have to achieve high levels of performance and competitiveness to stay "alive".Within this assumption, the building maintenance cannot be done in a casual and improvised way due to the costs related. Starting with some discussion about lean management and building maintenance, this paper introduces a model to support the Lean Building Maintenance (LBM) approach. Finally based on a real case study from a Portuguese company, the benefits, challenges and difficulties are presented and discussed.

Retroperitoneal Liposarcoma: Current Insights in Diagnosis and Treatment

PubMed Central

Matthyssens, Lucas E.; Creytens, David; Ceelen, Wim P.

2015-01-01

Retroperitoneal liposarcoma (RLS) is a rare, biologically heterogeneous tumor that present considerable challenges due to its size and deep location. As a consequence, the majority of patients with high-grade RLS will develop locally recurrent disease following surgery, and this constitutes the cause of death in most patients. Here, we review current insights and controversies regarding histology, molecular biology, extent of surgery, (neo)adjuvant treatment, and systemic treatment including novel targeted agents in RLS. PMID:25713799

An updated 26-year (1991-2017) sea level record from the Arctic Ocean

NASA Astrophysics Data System (ADS)

Kildegaard Rose, Stine; Baltazar Andersen, Ole; Passaro, Marcello; Benveniste, Jerome

2017-04-01

In recent years, there has been a large focus of the Arctic due the rapid changes of the region. The sea level of the Arctic Ocean is an important climate indicator. The Arctic sea ice is decreasing and has since 1997 experienced a steepening in the decrease. The Arctic sea level determination is challenging due to the seasonal to permanent sea ice cover, the lack of regional coverage of satellites, the satellite instruments ability to measure ice, insufficient geophysical models, residual orbit errors, challenging retracking of satellite altimeter data. We present the DTU/TUM 26-year sea level record based on satellite altimetry data in the Arctic Ocean from the ERS1 (1991) to CryoSat-2 (present) satellites. The sea level record is compared with several tide gauges and other available partial sea level records contributing to the ESA CCI Sea level initiative. We use updated geophysical corrections and a combination of altimeter data: REAPER (ERS1), ALES+ retracker (ERS2, Envisat), combined Rads and DTUs in-house retracker LARS (CryoSat-2). The ALES+ is an upgraded version of the Adaptive Leading Edge Subwaveform Retracker that has been developed to improve data quality and quantity in the coastal ocean, without degrading the results in the open ocean. ALES+ aims at retracking peaky waveforms typical of lead reflections without modifying the fitting model used in the open ocean.

Challenges and Opportunities in Reactive Processing and Applications of Advanced Ceramic Materials

NASA Technical Reports Server (NTRS)

Singh, Mrityunjay

2003-01-01

Recently, there has been a great deal of interest in the research, development, and commercialization of innovative synthesis and processing technologies for advanced ceramics and composite materials. Reactive processing approaches have been actively considered due to their robustness, flexibility, and affordability. A wide variety of silicon carbide-based advanced ceramics and composites are currently being fabricated using the processing approaches involving reactive infiltration of liquid and gaseous species into engineered fibrous or microporous carbon performs. The microporous carbon performs have been fabricated using the temperature induced phase separation and pyrolysis of two phase organic (resin-pore former) mixtures and fiber reinforcement of carbon and ceramic particulate bodies. In addition, pyrolyzed native plant cellulose tissues also provide unique carbon templates for manufacturing of non-oxide and oxide ceramics. In spite of great interest in this technology due to their affordability and robustness, there is a lack of scientific basis for process understanding and many technical challenges still remain. The influence of perform properties and other parameters on the resulting microstructure and properties of final material is not well understood. In this presentation, mechanism of silicon-carbon reaction in various systems and the effect of perform microstructure on the mechanical properties of advanced silicon carbide based materials will be discussed. Various examples of applications of reactively processed advanced silicon carbide ceramics and composite materials will be presented.

Pisgah Lava Cave Communication Test: Science Case Study for the Networked Constellations Initiative

NASA Technical Reports Server (NTRS)

Belov, K.; Ellison, D.; Fraeman, A.

2017-01-01

As part of the science case study for the Networked Constellations initiative, a team of JPL scientists explore the possibility of a mission to study the lava caves on Mars. Natural caves on Mars and the Moon present a unique opportunity to learn about the planetary geology and to provide a shelter for human explorers. Due to power and communication challenges, a network of assets has significant advantages over a single asset sent inside a cave. However, communication between the assets and the data downlink present significant difficulties due to the presence of rough walls, boulders, and other obstacles with unknown dielectric constant inside a typical cave, disturbing the propagation of the radio waves. A detailed study is needed to establish the limitations of the current communication technologies and to develop requirements for the new communication technology applicable to the cave environment. On May 4 of 2017, Konstantin Belov, Doug Ellison, and Abby Fraeman visited a lava cave in Pisgah, CA. The purpose of the visit was to build a 3D map of the cave, which could be used to create a model of radio wave propagation, and to conduct a series of communication tests using off-the-shelf equipment to verify the in-cave communication challenges. This experiment should be considered as a simple 'proof of concept' and is the subject of this report.

AnchorDock for Blind Flexible Docking of Peptides to Proteins.

PubMed

Slutzki, Michal; Ben-Shimon, Avraham; Niv, Masha Y

2017-01-01

Due to increasing interest in peptides as signaling modulators and drug candidates, several methods for peptide docking to their target proteins are under active development. The "blind" docking problem, where the peptide-binding site on the protein surface is unknown, presents one of the current challenges in the field. AnchorDock protocol was developed by Ben-Shimon and Niv to address this challenge.This protocol narrows the docking search to the most relevant parts of the conformational space. This is achieved by pre-folding the free peptide and by computationally detecting anchoring spots on the surface of the unbound protein. Multiple flexible simulated annealing molecular dynamics (SAMD) simulations are subsequently carried out, starting from pre-folded peptide conformations, constrained to the various precomputed anchoring spots.Here, AnchorDock is demonstrated using two known protein-peptide complexes. A PDZ-peptide complex provides a relatively easy case due to the relatively small size of the protein, and a typical peptide conformation and binding region; a more challenging example is a complex between USP7 N-term and a p53-derived peptide, where the protein is larger, and the peptide conformation and a binding site are generally assumed to be unknown. AnchorDock returned native-like solutions ranked first and third for the PDZ and USP7 complexes, respectively. We describe the procedure step by step and discuss possible modifications where applicable.

Automated fluorescent miscroscopic image analysis of PTBP1 expression in glioma

PubMed Central

Becker, Aline; Elder, Brad; Puduvalli, Vinay; Winter, Jessica; Gurcan, Metin

2017-01-01

Multiplexed immunofluorescent testing has not entered into diagnostic neuropathology due to the presence of several technical barriers, amongst which includes autofluorescence. This study presents the implementation of a methodology capable of overcoming the visual challenges of fluorescent microscopy for diagnostic neuropathology by using automated digital image analysis, with long term goal of providing unbiased quantitative analyses of multiplexed biomarkers for solid tissue neuropathology. In this study, we validated PTBP1, a putative biomarker for glioma, and tested the extent to which immunofluorescent microscopy combined with automated and unbiased image analysis would permit the utility of PTBP1 as a biomarker to distinguish diagnostically challenging surgical biopsies. As a paradigm, we utilized second resections from patients diagnosed either with reactive brain changes (pseudoprogression) and recurrent glioblastoma (true progression). Our image analysis workflow was capable of removing background autofluorescence and permitted quantification of DAPI-PTBP1 positive cells. PTBP1-positive nuclei, and the mean intensity value of PTBP1 signal in cells. Traditional pathological interpretation was unable to distinguish between groups due to unacceptably high discordance rates amongst expert neuropathologists. Our data demonstrated that recurrent glioblastoma showed more DAPI-PTBP1 positive cells and a higher mean intensity value of PTBP1 signal compared to resections from second surgeries that showed only reactive gliosis. Our work demonstrates the potential of utilizing automated image analysis to overcome the challenges of implementing fluorescent microscopy in diagnostic neuropathology. PMID:28282372

Challenges of caring for children with mental disorders: Experiences and views of caregivers attending the outpatient clinic at Muhimbili National Hospital, Dar es Salaam - Tanzania

PubMed Central

2012-01-01

Background It is estimated that world-wide up to 20 % of children suffer from debilitating mental illness. Mental disorders that pose a significant concern include learning disorders, hyperkinetic disorders (ADHD), depression, psychosis, pervasive development disorders, attachment disorders, anxiety disorders, conduct disorder, substance abuse and eating disorders. Living with such children can be very stressful for caregivers in the family. Therefore, determination of challenges of living with these children is important in the process of finding ways to help or support caregivers to provide proper care for their children. The purpose of this study was to explore the psychological and emotional, social, and economic challenges that parents or guardians experience when caring for mentally ill children and what they do to address or deal with them. Methodology A qualitative study design using in-depth interviews and focus group discussions was applied. The study was conducted at the psychiatric unit of Muhimbili National Hospital in Tanzania. Two focus groups discussions (FGDs) and 8 in-depth interviews were conducted with caregivers who attended the psychiatric clinic with their children. Data analysis was done using content analysis. Results The study revealed psychological and emotional, social, and economic challenges caregivers endure while living with mentally ill children. Psychological and emotional challenges included being stressed by caring tasks and having worries about the present and future life of their children. They had feelings of sadness, and inner pain or bitterness due to the disturbing behaviour of the children. They also experienced some communication problems with their children due to their inability to talk. Social challenges were inadequate social services for their children, stigma, burden of caring task, lack of public awareness of mental illness, lack of social support, and problems with social life. The economic challenges were poverty, child care interfering with various income generating activities in the family, and extra expenses associated with the child’s illness. Conclusion Caregivers of mentally ill children experience various psychological and emotional, social, and economic challenges. Professional assistance, public awareness of mental illnesses in children, social support by the government, private sector, and non-governmental organizations (NGOs) are important in addressing these challenges. PMID:22559084

Enhanced Fluoride Over-Coated Al Mirrors for FUV Astronomy

NASA Technical Reports Server (NTRS)

Quijada, Manuel A.; DelHoyo, Javier; Rice, Steve; Threat, Felix

2014-01-01

Astronomical observations in the Far Ultraviolet (FUV) spectral region are some of the more challenging due to the very distant and faint objects that are typically searched for in cosmic origin studies such as origin of large scale structure, the formation, evolution, and age of galaxies and the origin of stellar and planetary systems. These challenges are driving the need to improve the performance of optical coatings over a wide spectral range that would increase reflectance in mirrors and reduced absorption in dielectric filters used in optical telescope for FUV observations. This paper will present recent advances in reflectance performance for Al+MgF2 mirrors optimized for Lyman-alpha wavelength by performing the deposition of the MgF2 overcoat at elevated substrate temperatures. We will also present optical characterization of little studied rare-earth fluorides such as GdF3 and LuF3 that exhibit low-absorption over a wide wavelength range and could therefore be used as high refractive index alternatives for dielectric coatings at FUV wavelengths.

Guide to designing, conducting, publishing and communicating results of clinical studies involving probiotic applications in human participants

PubMed Central

Cabana, Michael D; Vidry, Stéphane; Merenstein, Dan; Hummelen, Ruben; Ellis, Collin L; Heimbach, James T; Hempel, Susanne; Lynch, Susan V; Sanders, Mary Ellen; Tancredi, Daniel J

2010-01-01

The heterogeneity of human clinical trials to assess the effectiveness of probiotics presents challenges regarding interpretation and comparison. Evidence obtained from clinical trials among a population with a disease or specific risk factors may not be generalizable to healthy individuals. The evaluation of interventions in healthy persons requires careful selection of outcomes due to the absence of health indicators and the low incidence of preventable conditions. Given the tremendous resources invested in such trials, development of consistent approaches to assessing the effectiveness of probiotics would be beneficial. Furthermore, the reporting, presentation and communication of results may also affect the validity of the scientific evidence obtained from a trial. This review outlines the challenges associated with the design, implementation, data analysis and interpretation of clinical trials in humans involving probiotics. Best practices related to their design are offered along with recommendations for enhanced collaboration to advance research in this emerging field. PMID:21327031

A Systems Approach to Scalable Transportation Network Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perumalla, Kalyan S

2006-01-01

Emerging needs in transportation network modeling and simulation are raising new challenges with respect to scal-ability of network size and vehicular traffic intensity, speed of simulation for simulation-based optimization, and fidel-ity of vehicular behavior for accurate capture of event phe-nomena. Parallel execution is warranted to sustain the re-quired detail, size and speed. However, few parallel simulators exist for such applications, partly due to the challenges underlying their development. Moreover, many simulators are based on time-stepped models, which can be computationally inefficient for the purposes of modeling evacuation traffic. Here an approach is presented to de-signing a simulator with memory andmore » speed efficiency as the goals from the outset, and, specifically, scalability via parallel execution. The design makes use of discrete event modeling techniques as well as parallel simulation meth-ods. Our simulator, called SCATTER, is being developed, incorporating such design considerations. Preliminary per-formance results are presented on benchmark road net-works, showing scalability to one million vehicles simu-lated on one processor.« less

Recent Progress on 2012 SAT for UVOIR Coatings

NASA Technical Reports Server (NTRS)

Quijada, Manuel A.; Del Hoyo, Javier G.; Rice, Stephen H.

2014-01-01

Astronomical observations in the Far Ultraviolet (FUV) spectral region are some of the more challenging due to the very distant and faint objects that are typically searched for in cosmic origin studies such as origin of large scale structure, the formation, evolution, and age of galaxies and the origin of stellar and planetary systems. These challenges are driving the need to improve the performance of optical coatings over a wide spectral range that would increase reflectance in mirrors and reduced absorption in dielectric filters used in optical telescope for FUV observations. This paper will present recent advances in reflectance performance for Al+MgF2 mirrors optimized for Lyman-alpha wavelength by performing the deposition of the MgF2 overcoat at elevated substrate temperatures. We will also present optical characterization of little studied rare-earth fluorides such as GdF3 and LuF3 that exhibit low-absorption over a wide wavelength range and could therefore be used as high refractive index alternatives fordielectric coatings at FUV wavelengths.

Optimized ex-ovo culturing of chick embryos to advanced stages of development.

PubMed

Cloney, Kellie; Franz-Odendaal, Tamara Anne

2015-01-24

Research in anatomy, embryology, and developmental biology has largely relied on the use of model organisms. In order to study development in live embryos model organisms, such as the chicken, are often used. The chicken is an excellent model organism due to its low cost and minimal maintenance, however they present observational challenges because they are enclosed in an opaque eggshell. In order to properly view the embryo as it develops, the shell must be windowed or removed. Both windowing and ex ovo techniques have been developed to assist researchers in the study of embryonic development. However, each of the methods has limitations and challenges. Here, we present a simple, optimized ex ovo culture technique for chicken embryos that enables the observation of embryonic development from stage HH 19 into late stages of development (HH 40), when many organs have developed. This technique is easy to adopt in both undergraduate classes and more advanced research laboratories where embryo manipulations are conducted.

Ceramic Integration Technologies for Advanced Energy Systems: Critical Needs, Technical Challenges, and Opportunities

NASA Technical Reports Server (NTRS)

Singh, Mrityunjay

2010-01-01

Advanced ceramic integration technologies dramatically impact the energy landscape due to wide scale application of ceramics in all aspects of alternative energy production, storage, distribution, conservation, and efficiency. Examples include fuel cells, thermoelectrics, photovoltaics, gas turbine propulsion systems, distribution and transmission systems based on superconductors, nuclear power generation and waste disposal. Ceramic integration technologies play a key role in fabrication and manufacturing of large and complex shaped parts with multifunctional properties. However, the development of robust and reliable integrated systems with optimum performance requires the understanding of many thermochemical and thermomechanical factors, particularly for high temperature applications. In this presentation, various needs, challenges, and opportunities in design, fabrication, and testing of integrated similar (ceramic ceramic) and dissimilar (ceramic metal) material www.nasa.gov 45 ceramic-ceramic-systems have been discussed. Experimental results for bonding and integration of SiC based Micro-Electro-Mechanical-Systems (MEMS) LDI fuel injector and advanced ceramics and composites for gas turbine applications are presented.

Traverse Planning with Temporal-Spatial Constraints

NASA Technical Reports Server (NTRS)

Bresina, John L.; Morris, Paul H.; Deans, Mathew C.; Cohen, Tamar E.; Lees, David S.

2017-01-01

We present an approach to planning rover traverses in a domain that includes temporal-spatial constraints. We are using the NASA Resource Prospector mission as a reference mission in our research. The objective of this mission is to explore permanently shadowed regions at a Lunar pole. Most of the time the rover is required to avoid being in shadow. This requirement depends on where the rover is located and when it is at that location. Such a temporal-spatial constraint makes traverse planning more challenging for both humans and machines. We present a mixed-initiative traverse planner which addresses this challenge. This traverse planner is part of the Exploration Ground Data Systems (xGDS), which we have enhanced with new visualization features, new analysis tools, and new automation for path planning, in order to be applicable to the Re-source Prospector mission. The key concept that is the basis of the analysis tools and that supports the automated path planning is reachability in this dynamic environment due to the temporal-spatial constraints.

Cancer in the Solomon Islands.

PubMed

Martiniuk, Alexandra; Jagilli, Rooney; Natuzzi, Eileen; Ilopitu, John Wesley; Oipata, Meltus; Christie, Annie-Marie; Korini, Jefferey; Vujovich-Dunn, Cassandra; Yu, William

2017-10-01

The Solomon Islands, with a population of 550,000, has significant challenges in addressing non-communicable diseases, including cancer, in the face of significant economic, cultural, general awareness and health system challenges. To summarise the existing knowledge regarding cancer in the Solomon Islands, to gather new data and make recommendations. A literature review was undertaken and cancer data from the National Referral Hospital, Honiara were analysed and are presented. Key stakeholders were interviewed for their perspectives including areas to target for ongoing, incremental improvements. Last, a health services audit for cancer using the WHO SARA tool was undertaken. Breast and cervical cancer remain the first and second most commonly identified cancers in the Solomon Islands. The Solomons cancer registry is hospital based and suffers from incomplete data collection due to its passive nature, lack of resources for data entry and processing resulting in weak data which is rarely used for decision-making. The health system audit revealed system and individual reasons for delayed diagnosis or lack of cancer treatment or palliation in the Solomon Islands. Reasons included lack of patient knowledge regarding symptoms, late referrals to the National Referral Hospital and inability of health care workers to detect cancers either due to lack of skills to do so, or lack of diagnostic capabilities, and an overall lack of access to any health care, due to geographical barriers and overall national economic fragility. The Solomon Islands is challenged in preventing, diagnosing, treating and palliating cancer. Stakeholders recommend establishing specialty expertise (in the form of a cancer unit), improved registry processes and increased collaboration between the sole tertiary hospital nationwide and other Solomon health services as important targets for incremental improvement. Copyright © 2017. Published by Elsevier Ltd.

Video-mosaicking of in vivo reflectance confocal microscopy images for noninvasive examination of skin lesion (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kose, Kivanc; Gou, Mengran; Yelamos, Oriol; Cordova, Miguel A.; Rossi, Anthony; Nehal, Kishwer S.; Camps, Octavia I.; Dy, Jennifer G.; Brooks, Dana H.; Rajadhyaksha, Milind

2017-02-01

In this report we describe a computer vision based pipeline to convert in-vivo reflectance confocal microscopy (RCM) videos collected with a handheld system into large field of view (FOV) mosaics. For many applications such as imaging of hard to access lesions, intraoperative assessment of MOHS margins, or delineation of lesion margins beyond clinical borders, raster scan based mosaicing techniques have clinically significant limitations. In such cases, clinicians often capture RCM videos by freely moving a handheld microscope over the area of interest, but the resulting videos lose large-scale spatial relationships. Videomosaicking is a standard computational imaging technique to register, and stitch together consecutive frames of videos into large FOV high resolution mosaics. However, mosaicing RCM videos collected in-vivo has unique challenges: (i) tissue may deform or warp due to physical contact with the microscope objective lens, (ii) discontinuities or "jumps" between consecutive images and motion blur artifacts may occur, due to manual operation of the microscope, and (iii) optical sectioning and resolution may vary between consecutive images due to scattering and aberrations induced by changes in imaging depth and tissue morphology. We addressed these challenges by adapting or developing new algorithmic methods for videomosaicking, specifically by modeling non-rigid deformations, followed by automatically detecting discontinuities (cut locations) and, finally, applying a data-driven image stitching approach that fully preserves resolution and tissue morphologic detail without imposing arbitrary pre-defined boundaries. We will present example mosaics obtained by clinical imaging of both melanoma and non-melanoma skin cancers. The ability to combine freehand mosaicing for handheld microscopes with preserved cellular resolution will have high impact application in diverse clinical settings, including low-resource healthcare systems.

Atmospheric rivers and past hydrometeorological extremes: Challenges and opportunities

NASA Astrophysics Data System (ADS)

Sodemann, Harald

2017-04-01

Atmospheric rivers are a key term for describing water vapour transport in extratropical regions. The concept has become particularly valuable for linking meteorological process understanding with research focused on the impacts of heavy precipitation. Atmospheric rivers are narrow, elongated features of high integrated water vapour and water vapour flux can lead to severe precipitation and flooding if moisture is extracted efficiently. The orographic rises at the West Coast of the United States and Western Norway are regions where Atmospheric Rivers are one of the prime mechanisms for moisture delivery and precipitation extremes in the present climate. Due to the small horizontal scales of some of the processes climate models are challenged to represent this important transport process between mid-latitudes and the subtropics faithfully. Recent aircraft data and regional tracer model studies provide new insight into the formation and moisture transport mechanisms. In this study I review the concept and pertinent processes of Atmospheric Rivers, thereby focusing on caveats, challenges and opportunities for understanding past hydrometeorological extremes.

Development Challenges of Game-Changing Entry System Technologies from Concept to Mission Infusion

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Beck, Robin; Ellerby, Don; Feldman, Jay; Gage, Peter; Munk, Michelle; Wercinski, Paul

2015-01-01

Realization within the US and NASA that future exploration both Human and Robotic will require innovative new technologies led to the creation of the Space Technology Mission Directorate and investment in game changing technologies with high pay-off. Some of these investments will see success and others, due to many of the constraints, will not attain their goal. The co-authors of this proposed presentation have been involved from concept to mission infusion aspects of entry technologies that are game changing. The four example technologies used to describe the challenges experienced along the pathways to success are at different levels of maturity. They are Conformal, 3-D MAT, HEEET and ADEPT. The four examples in many ways capture broad aspects of the challenges of maturation and illustrate what led some to be exceptionally successful and how others had to be altered in order remain viable game changing technologies. Subsystem technologies for robotic and human missions?

Mechanical Properties in Metal-Organic Frameworks: Emerging Opportunities and Challenges for Device Functionality and Technological Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burtch, Nicholas C.; Heinen, Jurn; Bennett, Thomas D.

We report that some of the most remarkable recent developments in metal–organic framework (MOF) performance properties can only be rationalized by the mechanical properties endowed by their hybrid inorganic–organic nanoporous structures. While these characteristics create intriguing application prospects, the same attributes also present challenges that will need to be overcome to enable the integration of MOFs with technologies where these promising traits can be exploited. In this review, emerging opportunities and challenges are identified for MOF-enabled device functionality and technological applications that arise from their fascinating mechanical properties. This is discussed not only in the context of their more well-studiedmore » gas storage and separation applications, but also for instances where MOFs serve as components of functional nanodevices. Recent advances in understanding MOF mechanical structure–property relationships due to attributes such as defects and interpenetration are highlighted, and open questions related to state-of-the-art computational approaches for quantifying their mechanical properties are critically discussed.« less

Physiological and Psychological Challenges of Increasing Physical Activity and Exercise in Patients at Risk of Diabetic Foot Ulcers: A Critical Review

PubMed Central

Crews, Ryan T.; Schneider, Kristin L.; Yalla, Sai V.; Reeves, Neil D.; Vileikyte, Loretta

2017-01-01

Obesity and a sedentary lifestyle are common challenges among individuals at risk of diabetic foot ulcers (DFUs). While substantial research exists on physical activity interventions in adults with diabetes, those at greatest risk for foot ulceration were often excluded or not well-represented. Both at-risk patients and their clinicians may be hesitant to increase physical activity due to their perception of DFU risks. Physical activity is not contraindicated for those at risk of DFU, yet patients at risk present with unique barriers to initiating increases in physical activity. This review focuses upon the physiological and psychological challenges of increasing physical activity and exercise in patients at risk of DFUs. Offloading, diabetic peripheral neuropathy, depression, pain, self-efficacy and social support, DFU risk-specific beliefs and emotions, and research to date on exercise interventions in this population are all discussed. Additionally, recommendations for implementing and researching physical activity interventions for individuals at risk for DFU are provided. PMID:27155091

Mechanical Properties in Metal-Organic Frameworks: Emerging Opportunities and Challenges for Device Functionality and Technological Applications

DOE PAGES

Burtch, Nicholas C.; Heinen, Jurn; Bennett, Thomas D.; ...

2017-11-17

We report that some of the most remarkable recent developments in metal–organic framework (MOF) performance properties can only be rationalized by the mechanical properties endowed by their hybrid inorganic–organic nanoporous structures. While these characteristics create intriguing application prospects, the same attributes also present challenges that will need to be overcome to enable the integration of MOFs with technologies where these promising traits can be exploited. In this review, emerging opportunities and challenges are identified for MOF-enabled device functionality and technological applications that arise from their fascinating mechanical properties. This is discussed not only in the context of their more well-studiedmore » gas storage and separation applications, but also for instances where MOFs serve as components of functional nanodevices. Recent advances in understanding MOF mechanical structure–property relationships due to attributes such as defects and interpenetration are highlighted, and open questions related to state-of-the-art computational approaches for quantifying their mechanical properties are critically discussed.« less

Caring for Refugee Youth in the School Setting.

PubMed

Johnson, Jennifer Leigh; Beard, Joyce; Evans, Dena

2017-03-01

Annually, over 80,000 refugees enter the United States as a result of political or religious persecution. Of these, approximately 35% to 40% are children and adolescents. Refugees are faced with challenges associated with living conditions, cultural and social norms, and socioeconomic status due to problems occurring in their homelands. These challenges include but are not limited to malnutrition, communicable disease, questionable immunization status, lack of formal education, sexual abuse, violence, torture, human trafficking, homelessness, poverty, and a lack of access to health care. Moreover, the psychological impact of relocation and the stress of acculturation may perpetuate many of these existing challenges, particularly for refugee youth, with limited or underdeveloped coping skills. School nurses are uniquely poised to support refugee youth in the transition process, improve overall health, and facilitate access to primary health services. The purpose of this article is to provide an overview of the unique refugee experience, examine the key health care needs of the population, and present school nurses with timely and relevant resources to assist in caring for refugee youth.

Mechanical Properties in Metal-Organic Frameworks: Emerging Opportunities and Challenges for Device Functionality and Technological Applications.

PubMed

Burtch, Nicholas C; Heinen, Jurn; Bennett, Thomas D; Dubbeldam, David; Allendorf, Mark D

2017-11-17

Some of the most remarkable recent developments in metal-organic framework (MOF) performance properties can only be rationalized by the mechanical properties endowed by their hybrid inorganic-organic nanoporous structures. While these characteristics create intriguing application prospects, the same attributes also present challenges that will need to be overcome to enable the integration of MOFs with technologies where these promising traits can be exploited. In this review, emerging opportunities and challenges are identified for MOF-enabled device functionality and technological applications that arise from their fascinating mechanical properties. This is discussed not only in the context of their more well-studied gas storage and separation applications, but also for instances where MOFs serve as components of functional nanodevices. Recent advances in understanding MOF mechanical structure-property relationships due to attributes such as defects and interpenetration are highlighted, and open questions related to state-of-the-art computational approaches for quantifying their mechanical properties are critically discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DMDs for multi-object near-infrared spectrographs in astronomy

NASA Astrophysics Data System (ADS)

Smee, Stephen A.; Barkhouser, Robert; Hope, Stephen; Conley, Devin; Gray, Aidan; Hope, Gavin; Robberto, Massimo

2018-02-01

The Digital Micromirror Device (DMD), typically used in projection screen technology, has utility in instrumentation for astronomy as a digitally programmable slit in a spectrograph. When placed at an imaging focal plane the device can be used to selectively direct light from astronomical targets into the optical path of a spectrograph, while at the same time directing the remaining light into an imaging camera, which can be used for slit alignment, science imaging, or both. To date the use of DMDs in astronomy has been limited, especially for instruments that operate in the near infrared (1 - 2.5 μm). This limitation is due in part to a host of technical challenges with respect to DMDs that, to date, have not been thoroughly explored. Those challenges include operation at cryogenic temperature, control electronics that facilitate DMD use at these temperatures, window coatings properly coated for the near infrared bandpass, and scattered light. This paper discusses these technical challenges and presents progress towards understanding and mitigating them.

Efficient Learning of Continuous-Time Hidden Markov Models for Disease Progression

PubMed Central

Liu, Yu-Ying; Li, Shuang; Li, Fuxin; Song, Le; Rehg, James M.

2016-01-01

The Continuous-Time Hidden Markov Model (CT-HMM) is an attractive approach to modeling disease progression due to its ability to describe noisy observations arriving irregularly in time. However, the lack of an efficient parameter learning algorithm for CT-HMM restricts its use to very small models or requires unrealistic constraints on the state transitions. In this paper, we present the first complete characterization of efficient EM-based learning methods for CT-HMM models. We demonstrate that the learning problem consists of two challenges: the estimation of posterior state probabilities and the computation of end-state conditioned statistics. We solve the first challenge by reformulating the estimation problem in terms of an equivalent discrete time-inhomogeneous hidden Markov model. The second challenge is addressed by adapting three approaches from the continuous time Markov chain literature to the CT-HMM domain. We demonstrate the use of CT-HMMs with more than 100 states to visualize and predict disease progression using a glaucoma dataset and an Alzheimer’s disease dataset. PMID:27019571

An interactive online approach to small-group student presentations and discussions.

PubMed

Thor, Der; Xiao, Nan; Zheng, Meixun; Ma, Ruidan; Yu, Xiao Xi

2017-12-01

Student presentations had been widely implemented across content areas, including health sciences education. However, due to various limitations, small-group student presentations in the classroom may not reach their full potential for student learning. To address challenges with presentations in the classroom, we redesigned the assignment by having students present and discuss online using VoiceThread, a cloud-based presentation and discussion tool. First-year students pursuing a Doctor of Dental Surgery degree were assigned into small groups to present physiology content and to discuss that content online. This assignment was similar to traditional student classroom presentations, with the exception that the entire assignment was conducted online. The primary purpose of this exploratory study was to investigate the impact of the online format on the discussion quality. Another purpose of the study was to examine students' perceptions of using VoiceThread for presenting and learning, as well as the online interactions between the presenter and audience. Students posted a higher number of questions and comments than required by the assignment. The questions from students were also higher level questions, and the answers to these questions were more thorough compared with what we had previously observed in classroom presentations. The survey results showed that students preferred using VoiceThread for presenting, learning from other presentations, and discussing presentation content over performing this process in the classroom. Preliminary findings suggested that having dental students make presentations and hold discussions online might help address the challenges of student presentations in the classroom. Copyright © 2017 the American Physiological Society.

Introduction to State Estimation of High-Rate System Dynamics.

PubMed

Hong, Jonathan; Laflamme, Simon; Dodson, Jacob; Joyce, Bryan

2018-01-13

Engineering systems experiencing high-rate dynamic events, including airbags, debris detection, and active blast protection systems, could benefit from real-time observability for enhanced performance. However, the task of high-rate state estimation is challenging, in particular for real-time applications where the rate of the observer's convergence needs to be in the microsecond range. This paper identifies the challenges of state estimation of high-rate systems and discusses the fundamental characteristics of high-rate systems. A survey of applications and methods for estimators that have the potential to produce accurate estimations for a complex system experiencing highly dynamic events is presented. It is argued that adaptive observers are important to this research. In particular, adaptive data-driven observers are advantageous due to their adaptability and lack of dependence on the system model.

Seafood traceability: current needs, available tools, and biotechnological challenges for origin certification.

PubMed

Leal, Miguel Costa; Pimentel, Tânia; Ricardo, Fernando; Rosa, Rui; Calado, Ricardo

2015-06-01

Market globalization and recurring food safety alerts have resulted in a growing consumer awareness of the need for food traceability. This is particularly relevant for seafood due to its perishable nature and importance as a key protein source for the population of the world. Here, we provide an overview of the current needs for seafood origin traceability, along with the limitations and challenges for its implementation. We focus on geochemical, biochemical, and molecular tools and how they should be optimized to be implemented globally and to address our societal needs. We suggest that seafood traceability is key to enforcing food safety regulations and fisheries control, combat fraud, and fulfill present and future expectations of conscientious producers, consumers, and authorities. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genome-Wide Association Studies of Drug-Resistance Determinants.

PubMed

Volkman, Sarah K; Herman, Jonathan; Lukens, Amanda K; Hartl, Daniel L

2017-03-01

Population genetic strategies that leverage association, selection, and linkage have identified drug-resistant loci. However, challenges and limitations persist in identifying drug-resistance loci in malaria. In this review we discuss the genetic basis of drug resistance and the use of genome-wide association studies, complemented by selection and linkage studies, to identify and understand mechanisms of drug resistance and response. We also discuss the implications of nongenetic mechanisms of drug resistance recently reported in the literature, and present models of the interplay between nongenetic and genetic processes that contribute to the emergence of drug resistance. Throughout, we examine artemisinin resistance as an example to emphasize challenges in identifying phenotypes suitable for population genetic studies as well as complications due to multiple-factor drug resistance. Copyright © 2016. Published by Elsevier Ltd.

Challenges in the analysis of complex systems: introduction and overview

NASA Astrophysics Data System (ADS)

Hastings, Harold M.; Davidsen, Jörn; Leung, Henry

2017-12-01

One of the main challenges of modern physics is to provide a systematic understanding of systems far from equilibrium exhibiting emergent behavior. Prominent examples of such complex systems include, but are not limited to the cardiac electrical system, the brain, the power grid, social systems, material failure and earthquakes, and the climate system. Due to the technological advances over the last decade, the amount of observations and data available to characterize complex systems and their dynamics, as well as the capability to process that data, has increased substantially. The present issue discusses a cross section of the current research on complex systems, with a focus on novel experimental and data-driven approaches to complex systems that provide the necessary platform to model the behavior of such systems.

Ice Surfaces.

PubMed

Shultz, Mary Jane

2017-05-05

Ice is a fundamental solid with important environmental, biological, geological, and extraterrestrial impact. The stable form of ice at atmospheric pressure is hexagonal ice, I h . Despite its prevalence, I h remains an enigmatic solid, in part due to challenges in preparing samples for fundamental studies. Surfaces of ice present even greater challenges. Recently developed methods for preparation of large single-crystal samples make it possible to reproducibly prepare any chosen face to address numerous fundamental questions. This review describes preparation methods along with results that firmly establish the connection between the macroscopic structure (observed in snowflakes, microcrystallites, or etch pits) and the molecular-level configuration (detected with X-ray or electron scattering techniques). Selected results of probing interactions at the ice surface, including growth from the melt, surface vibrations, and characterization of the quasi-liquid layer, are discussed.

Challenges to reestablishment of free-ranging populations of black-footed ferrets

USGS Publications Warehouse

Biggins, D.E.; Godbey, J.L.

2003-01-01

The black-footed ferret (Mustela nigripes) of North America is critically endangered due in part to its extreme specialization on formerly stable and abundant prairie dogs (Cynomys). Its close relative, the Siberian polecat (M. eversmannii) seems to have been subjected to a varying environment that was not conducive to specialization. One source of environmental variation in Asian steppes was plague (caused by Yersina pestis), which was absent from North America. Introduction of plague to North America presents serious challenges to ferret recovery. Partial solutions to other biological and political problems have been found, resulting in improved production in captivity, increased survival post-release, and thriving populations in plague-free South Dakota. ?? 2003 Acade??mie des sciences. Published by E??ditions scientifiques et me??dicales Elsevier SAS. All rights reserved.

FUV Reflectance of Recently Prepared Al Protected with AlF3: COR Program Technology Development

NASA Technical Reports Server (NTRS)

Quijada, Manuel

2016-01-01

Astronomical observations in the Far Ultraviolet (FUV) spectral region are some of the more challenging due to the very distant and faint objects that are typically searched for in cosmic origin studies such as origin of large scale structure, the formation, evolution, and age of galaxies and the origin of stellar and planetary systems. These challenges are driving the need to improve the performance of optical coatings over a wide spectral range that would increase reflectance in mirrors and reduced absorption in dielectric filters used in optical telescope for FUV observations. This paper will present recent advances in reflectance performance for Al+AlF3 mirrors optimized for Lyman-alpha wavelength by performing the deposition of the AlF3 overcoat at elevated substrate temperatures.

Dual species entanglement of Rb and Cs qubits with Rydberg blockade for crosstalk free qubit measurements

NASA Astrophysics Data System (ADS)

Baker, Kevin; Yu, Zhaoning; Ebert, Matthew; Sun, Yuan; Saffman, Mark

2016-05-01

One of the outstanding challenges facing neutral atom qubit approaches to quantum computation is suppression of crosstalk between proximal qubits due to scattered light that is generated during optical pumping and measurement operations. We have recently proposed a dual species approach to solving this challenge whereby computational qubits encoded in Cs atoms are entangled with Rb atoms via an interspecies Rydberg interaction. The quantum state of a Cs atom can then be readout by measuring the state of a Rb atom. The difference in resonant wavelengths of the two species effectively suppresses crosstalk. We will present progress towards experimental demonstration of dual species entanglement using Rb and Cs atoms cotrapped in a single beam optical trap. Work supported by the ARL CDQI.

Implementation of workflow engine technology to deliver basic clinical decision support functionality

PubMed Central

2011-01-01

Background Workflow engine technology represents a new class of software with the ability to graphically model step-based knowledge. We present application of this novel technology to the domain of clinical decision support. Successful implementation of decision support within an electronic health record (EHR) remains an unsolved research challenge. Previous research efforts were mostly based on healthcare-specific representation standards and execution engines and did not reach wide adoption. We focus on two challenges in decision support systems: the ability to test decision logic on retrospective data prior prospective deployment and the challenge of user-friendly representation of clinical logic. Results We present our implementation of a workflow engine technology that addresses the two above-described challenges in delivering clinical decision support. Our system is based on a cross-industry standard of XML (extensible markup language) process definition language (XPDL). The core components of the system are a workflow editor for modeling clinical scenarios and a workflow engine for execution of those scenarios. We demonstrate, with an open-source and publicly available workflow suite, that clinical decision support logic can be executed on retrospective data. The same flowchart-based representation can also function in a prospective mode where the system can be integrated with an EHR system and respond to real-time clinical events. We limit the scope of our implementation to decision support content generation (which can be EHR system vendor independent). We do not focus on supporting complex decision support content delivery mechanisms due to lack of standardization of EHR systems in this area. We present results of our evaluation of the flowchart-based graphical notation as well as architectural evaluation of our implementation using an established evaluation framework for clinical decision support architecture. Conclusions We describe an implementation of a free workflow technology software suite (available at http://code.google.com/p/healthflow) and its application in the domain of clinical decision support. Our implementation seamlessly supports clinical logic testing on retrospective data and offers a user-friendly knowledge representation paradigm. With the presented software implementation, we demonstrate that workflow engine technology can provide a decision support platform which evaluates well against an established clinical decision support architecture evaluation framework. Due to cross-industry usage of workflow engine technology, we can expect significant future functionality enhancements that will further improve the technology's capacity to serve as a clinical decision support platform. PMID:21477364

Experimental verification of Space Platform battery discharger design optimization

NASA Astrophysics Data System (ADS)

Sable, Dan M.; Deuty, Scott; Lee, Fred C.; Cho, Bo H.

The detailed design of two candidate topologies for the Space Platform battery discharger, a four module boost converter (FMBC) and a voltage-fed push-pull autotransformer (VFPPAT), is presented. Each has unique problems. The FMBC requires careful design and analysis in order to obtain good dynamic performance. This is due to the presence of a right-half-plane (RHP) zero in the control-to-output transfer function. The VFPPAT presents a challenging power stage design in order to yield high efficiency and light component weight. The authors describe the design of each of these converters and compare their efficiency, weight, and dynamic characteristics.

Distraction: an assessment of smartphone usage in health care work settings

PubMed Central

Gill, Preetinder S; Kamath, Ashwini; Gill, Tejkaran S

2012-01-01

Smartphone use in health care work settings presents both opportunities and challenges. The benefits could be severely undermined if abuse and overuse are not kept in check. This practice-focused research paper examines the current panorama of health software applications. Findings from existing research are consolidated to elucidate the level and effects of distraction in health care work settings due to smartphone use. A conceptual framework for crafting guidelines to regulate the use of smartphones in health care work settings is then presented. Finally, specific guidelines are delineated to assist in creating policies for the use of smartphones in a health care workplace. PMID:22969308

Dark Energy: A Crisis for Fundamental Physics

ScienceCinema

Stubbs, Christopher [Harvard University, Cambridge, Massachusetts, USA

2017-12-09

Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talk will present experiments and observations that are exploring this issue.

Cheilitis Granulomatosa: A Case Report with Review of Literature

PubMed Central

Vibhute, Nupura A; Vibhute, Aniket H; Daule, Nilima R

2013-01-01

Cheilitis granulomatosa (CG) is a chronic swelling of the lip due to granulomatous inflammation. It is a rare inflammatory disorder first described by Miescher in 1945. It is a monosymptomatic form or an incomplete variant of Melkersson-Rosenthal syndrome; a triad of recurrent orofacial edema, recurrent facial nerve palsy and fissuring of the tongue. As the etiology remains unknown, treatment of CG is challenging. We present a case of CG in a 43-year-old female patient secondary to allergy to certain food items. The present case highlights the importance of thorough investigations in the diagnosis of this lesion as the findings mimic many other granulomatous conditions. PMID:23723497

Scalable nuclear density functional theory with Sky3D

NASA Astrophysics Data System (ADS)

Afibuzzaman, Md; Schuetrumpf, Bastian; Aktulga, Hasan Metin

2018-02-01

In nuclear astrophysics, quantum simulations of large inhomogeneous dense systems as they appear in the crusts of neutron stars present big challenges. The number of particles in a simulation with periodic boundary conditions is strongly limited due to the immense computational cost of the quantum methods. In this paper, we describe techniques for an efficient and scalable parallel implementation of Sky3D, a nuclear density functional theory solver that operates on an equidistant grid. Presented techniques allow Sky3D to achieve good scaling and high performance on a large number of cores, as demonstrated through detailed performance analysis on a Cray XC40 supercomputer.

Bidirectional peripheral nerve interface and applications.

PubMed

Thakor, Nitish V; Qihong Wang; Greenwald, Elliot

2016-08-01

Peripheral nerves, due to their small size and complex innervation to organs and complex physiology, pose particularly significant challenges towards interfacing electrodes and electronics to enable neuromodulation. Here, we present a review of the technology for building such interface, including recording and stimulating electrodes and low power electronics, as well as powering. Of particular advantage to building a miniature implanted device is a "bidirectional" system that both senses from the nerves or surrogate organs and stimulates the nerves to affect the organ function. This review and presentation will cover a range of electrodes, electronics, wireless power and data schemes and system integration, and will end with some examples and applications.

Round-Trip Solar Electric Propulsion Missions for Mars Sample Return

NASA Technical Reports Server (NTRS)

Bailey, Zachary J.; Sturm, Erick J.; Kowalkowski, Theresa D.; Lock, Robert E.; Woolley, Ryan C.; Nicholas, Austin K.

2014-01-01

Mars Sample Return (MSR) missions could benefit from the high specific impulse of Solar Electric Propulsion (SEP) to achieve lower launch masses than with chemical propulsion. SEP presents formulation challenges due to the coupled nature of launch vehicle performance, propulsion system, power system, and mission timeline. This paper describes a SEP orbiter-sizing tool, which models spacecraft mass & timeline in conjunction with low thrust round-trip Earth-Mars trajectories, and presents selected concept designs. A variety of system designs are possible for SEP MSR orbiters, with large dry mass allocations, similar round-trip durations to chemical orbiters, and reduced design variability between opportunities.

Experimental verification of Space Platform battery discharger design optimization

NASA Technical Reports Server (NTRS)

Sable, Dan M.; Deuty, Scott; Lee, Fred C.; Cho, Bo H.

1991-01-01

The detailed design of two candidate topologies for the Space Platform battery discharger, a four module boost converter (FMBC) and a voltage-fed push-pull autotransformer (VFPPAT), is presented. Each has unique problems. The FMBC requires careful design and analysis in order to obtain good dynamic performance. This is due to the presence of a right-half-plane (RHP) zero in the control-to-output transfer function. The VFPPAT presents a challenging power stage design in order to yield high efficiency and light component weight. The authors describe the design of each of these converters and compare their efficiency, weight, and dynamic characteristics.

Specific-pathogen-free chickens vaccinated with a live FAdV-4 vaccine are fully protected against a severe challenge even in the absence of neutralizing antibodies.

PubMed

Schonewille, Esther; Jaspers, Ron; Paul, Guntram; Hess, Michael

2010-06-01

By adapting a very virulent fowl adenovirus serotype 4 (FAdV-4) to a fibroblast cell line (QT35) instead of growing the virus in chicken embryo liver cells or chicken kidney cells, it was possible to attenuate the virus. Birds infected with the attenuated virus (FAdV-4/QT35) on the first day of life expressed no adverse clinical signs and no mortality. Intramuscular challenge with the virulent virus grown on chicken embryo liver cells (FAdV-4/CEL) at 21 days of life induced high mortality in previously nonvaccinated birds, whereas none of the birds vaccinated at 1 day old with FAdV-4/QT35 died due to this challenge. Applying enzyme-linked immunosorbent assay and virus neutralization assay, only a weak antibody response could be detected in some birds following vaccination, a response that increased directly after challenge. Nonvaccinated birds displayed a delayed development of antibodies after challenge as compared to previously vaccinated birds. Even birds that did not develop a measurable neutralizing antibody titer prior to challenge were protected from the adverse effects of the virulent FAdV-4/CEL, a phenomenon not described so far for FAdVs. Altogether, the present investigation underlines that neutralizing antibodies are not needed to protect chickens against a severe infection with a virulent fowl adenovirus.

Estimating challenge load due to disease outbreaks and other challenges using reproduction records of sows.

PubMed

Mathur, P K; Herrero-Medrano, J M; Alexandri, P; Knol, E F; ten Napel, J; Rashidi, H; Mulder, H A

2014-12-01

A method was developed and tested to estimate challenge load due to disease outbreaks and other challenges in sows using reproduction records. The method was based on reproduction records from a farm with known disease outbreaks. It was assumed that the reduction in weekly reproductive output within a farm is proportional to the magnitude of the challenge. As the challenge increases beyond certain threshold, it is manifested as an outbreak. The reproduction records were divided into 3 datasets. The first dataset called the Training dataset consisted of 57,135 reproduction records from 10,901 sows from 1 farm in Canada with several outbreaks of porcine reproductive and respiratory syndrome (PRRS). The known disease status of sows was regressed on the traits number born alive, number of losses as a combination of still birth and mummified piglets, and number of weaned piglets. The regression coefficients from this analysis were then used as weighting factors for derivation of an index measure called challenge load indicator. These weighting factors were derived with i) a two-step approach using residuals or year-week solutions estimated from a previous step, and ii) a single-step approach using the trait values directly. Two types of models were used for each approach: a logistic regression model and a general additive model. The estimates of challenge load indicator were then compared based on their ability to detect PRRS outbreaks in a Test dataset consisting of records from 65,826 sows from 15 farms in the Netherlands. These farms differed from the Canadian farm with respect to PRRS virus strains, severity and frequency of outbreaks. The single-step approach using a general additive model was best and detected 14 out of the 15 outbreaks. This approach was then further validated using the third dataset consisting of reproduction records of 831,855 sows in 431 farms located in different countries in Europe and America. A total of 41 out of 48 outbreaks detected using data analysis were confirmed based on diagnostic information received from the farms. Among these, 30 outbreaks were due to PRRS while 11 were due to other diseases and challenging conditions. The results suggest that proposed method could be useful for estimation of challenge load and detection of challenge phases such as disease outbreaks.

Occupational asthma due to turpentine in art painter--case report.

PubMed

Dudek, Wojciech; Wittczak, Tomasz; Swierczyńska-Machura, Dominika; Walusiak-Skorupa, Jolanta; Pałczyński, Cezary

2009-01-01

Turpentine is a fluid obtained by distillation of wood resins containing mixture of terpens. It can act as an irritant and sensitiser. Most common health problem among workers exposed to turpentine is contact dermatitis. Little is know about turpentine to cause type I hypersensitivity reaction. We present a case of a 27-year old art painter using turpentine as a thinner for oil-based paints. She developed asthmatic reactions after 5 years of working with turpentine. A number of clinical procedures were performed, including clinical examination, routine laboratory tests, total serum IgE, skin prick tests to common aeroallergens, metal salts, oil-based paints and balsamic turpentine, resting spirometry test, histamine challenge, and a single-blind, placebo-controlled specific inhalation challenge with balsamic turpentine. Clinical findings and laboratory test results were normal but a significant bronchial hyperreactivity was found. During the specific challenge, dyspnoea and decreased forced expiratory volume (FEV1) were observed in late phase of asthmatic reaction. An increased proportion of eosinophils in induced sputum could also be noted 24 h after the challenge. Positive clinical response to the specific challenge as well as the morphological changes found in induced sputum served as the basis for diagnosing occupational asthma. To our knowledge, this is the first well-documented case of turpentine-induced occupational asthma.

Extra peritoneal giant pelvic hibernoma: a case report

PubMed Central

Zimmitti, Giuseppe; Manzoni, Alberto; Sega, Valentina; Guerini, Francesca; Mutti, Stefano; Lombardi, Mariano; Bonaventure, Tamu; Rosso, Edoardo

2017-01-01

Abstract Abdominal hibernoma is a rare slow-growing tumor originating from brown adipose tissue. Due to its rarity, only a few case reports have been published so far. Pelvic localization is anedoctal and preoperative differential diagnosis with other malignancies may be challenging. We present the case of a woman who, due to a lower abdominal pain, underwent an abdominal ultrasonography with diagnosis of a 15 cm hyperechogenous pelvic mass. A subsequent MRI showed a 16 × 5.8 × 7.8 cm3 lesion anterior to the left iliacus muscle, with an intra- and extrapelvic component longitudinally extending from the left anterior superior iliac spine until the lesser trochanter. Surgical resection was performed and final histopathology was consistent with hibernoma. This report emphasizes the necessity to include hibernoma among differential diagnosis when a retroperitoneal abdominal mass is diagnosed and the difficulty to perform preoperatively this diagnosis due to the extreme rarity of these neoplasms. PMID:29255590

Extra peritoneal giant pelvic hibernoma: a case report.

PubMed

Treppiedi, Elio; Zimmitti, Giuseppe; Manzoni, Alberto; Sega, Valentina; Guerini, Francesca; Mutti, Stefano; Lombardi, Mariano; Bonaventure, Tamu; Rosso, Edoardo

2017-12-01

Abdominal hibernoma is a rare slow-growing tumor originating from brown adipose tissue. Due to its rarity, only a few case reports have been published so far. Pelvic localization is anedoctal and preoperative differential diagnosis with other malignancies may be challenging. We present the case of a woman who, due to a lower abdominal pain, underwent an abdominal ultrasonography with diagnosis of a 15 cm hyperechogenous pelvic mass. A subsequent MRI showed a 16 × 5.8 × 7.8 cm 3 lesion anterior to the left iliacus muscle, with an intra- and extrapelvic component longitudinally extending from the left anterior superior iliac spine until the lesser trochanter. Surgical resection was performed and final histopathology was consistent with hibernoma. This report emphasizes the necessity to include hibernoma among differential diagnosis when a retroperitoneal abdominal mass is diagnosed and the difficulty to perform preoperatively this diagnosis due to the extreme rarity of these neoplasms.

Full-mouth esthetic rehabilitation with acellular dermal matrix.

PubMed

Clozza, Emanuele; Suzuki, Takanori; Engebretson, Steven P

2014-01-01

Treatment of multiple recession defects with the adjunct use of a connective tissue graft (CTG) represents a challenge when diagnosed in several teeth of the mouth. The amount of CTG harvested from the palate may not be adequate to address this condition. In such scenarios, alternative sources such as acellular dermal matrix (ADM) are preferred due to the unlimited availability. A case report is presented, dealing with the treatment of multiple gingival recessions affecting the majority of dentition using ADM, with a 6-month follow-up.

Therapeutic cloning and cellular reprogramming.

PubMed

Rodriguez, Ramon M; Ross, Pablo J; Cibelli, Jose B

2012-01-01

Embryonic stem cells are capable of differentiating into any cell-type present in an adult organism, and constitute a renewable source of tissue for regenerative therapies. The transplant of allogenic stem cells is challenging due to the risk of immune rejection. Nevertheless, somatic cell reprogramming techniques allow the generation of isogenic embryonic stem cells, genetically identical to the patient. In this chapter we will discuss the cellular reprogramming techniques in the context of regenerative therapy and the biological and technical barriers that they will need to overcome before clinical use.

Blood Banking in Living Droplets

PubMed Central

Shao, Lei; Zhang, Xiaohui; Xu, Feng; Song, YoungSeok; Keles, Hasan Onur; Matloff, Laura; Markel, Jordan; Demirci, Utkan

2011-01-01

Blood banking has a broad public health impact influencing millions of lives daily. It could potentially benefit from emerging biopreservation technologies. However, although vitrification has shown advantages over traditional cryopreservation techniques, it has not been incorporated into transfusion medicine mainly due to throughput challenges. Here, we present a scalable method that can vitrify red blood cells in microdroplets. This approach enables the vitrification of large volumes of blood in a short amount of time, and makes it a viable and scalable biotechnology tool for blood cryopreservation. PMID:21412411

Ongoing measles outbreak in Wallonia, Belgium, December 2016 to March 2017: characteristics and challenges

PubMed Central

Grammens, Tine; Schirvel, Carole; Leenen, Sylvie; Shodu, Nathalie; Hutse, Veronik; Mendes da Costa, Elise; Sabbe, Martine

2017-01-01

We describe characteristics of an ongoing measles outbreak in Wallonia, Belgium, and difficulties in control measures implementation. As at 12 March 2017, 177 measles cases were notified, of which 50% were 15 years and older, 49% female. Atypical clinical presentation and severe complications, mainly among adults, in combination with late notification, low or unknown vaccination coverage of contacts, infected healthcare workers and increased workload due to contact tracing, are the main concerns for outbreak management. PMID:28488998

Architectural design and support for knowledge sharing across heterogeneous MAST systems

NASA Astrophysics Data System (ADS)

Arkin, Ronald C.; Garcia-Vergara, Sergio; Lee, Sung G.

2012-06-01

A novel approach for the sharing of knowledge between widely heterogeneous robotic agents is presented, drawing upon Gardenfors Conceptual Spaces approach [4]. The target microrobotic platforms considered are computationally, power, sensor, and communications impoverished compared to more traditional robotics platforms due to their small size. This produces novel challenges for the system to converge on an interpretation of events within the world, in this case specifically focusing on the task of recognizing the concept of a biohazard in an indoor setting.

Selection of appropriate treatment options for hand fractures.

PubMed

Sammer, Douglas M; Husain, Tarik; Ramirez, Rey

2013-11-01

Selecting the appropriate treatment method for hand fractures is challenging due to the wide spectrum of presentation and the enormous array of surgical and nonoperative treatment options. Unfortunately, the scientific evidence to help guide decision making is not of high quality. Because of this, the surgeon must rely on a few basic principles to guide treatment. This article provides an overview of the scientific evidence, and discusses the principles and rationale used to treat hand fractures. Copyright © 2013 Elsevier Inc. All rights reserved.

Osteoid osteoma of the scaphoid: magnetic resonance imaging vessel sign.

PubMed

Kussman, Steven R; Thompson, Michael; Chang, Eric Y

2015-01-01

Osteoid osteomas can be a challenging diagnosis, especially in smaller bones and, particularly, in the carpus. Clinical and imaging diagnosis may both be delayed due to other, more common, post-traumatic or inflammatory pathology in the same area. We present a case of a pathologically proven scaphoid osteoid osteoma with a feeding vessel sign on magnetic resonance imaging, previously described in long bones with computed tomography, as a helpful sign for accurate diagnosis in the scaphoid. Copyright © 2015 Elsevier Inc. All rights reserved.

Retroperitoneal Extraskeletal Osteosarcoma: Imaging Findings and Transarterial Chemoembolization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Huojun, E-mail: chyyzhj@hotmail.com; Yang Jijin, E-mail: yangjijin@live.com; Lu Jianping

2010-04-15

Extraskeletal osteosarcoma (EOS) is an uncommon and usually highly aggressive mesenchymal tumor. Retroperitoneal extraskeletal osteosarma (REOS) is exceedingly rare. Due to the rare nature of the disease, both the diagnosis and the management of REOS can be challenging. We present the clinical history, CT findings, angiographic manifestations, and use of transarterial chemoembolization for treatment in a case of REOS. To our knowledge, the angiographic features of and attempt at transarterial treatment of REOS have not been reported in the literature.

Cartilage Delamination Flap Mimicking a Torn Medial Meniscus

PubMed Central

Bin Abd Razak, Hamid Rahmatullah; Amit Kanta, Mitra

2016-01-01

We report a case of a chondral delamination lesion due to medial parapatellar plica friction syndrome involving the medial femoral condyle. This mimicked a torn medial meniscus in clinical and radiological presentation. Arthroscopy revealed a chondral delamination flap, which was debrided. Diagnosis of chondral lesions in the knee can be challenging. Clinical examination and MRI have good accuracy for diagnosis and should be used in tandem. Early diagnosis and treatment of chondral lesions are important to prevent progression to early osteoarthritis. PMID:28070434

Reference software implementation for GIFTS ground data processing

NASA Astrophysics Data System (ADS)

Garcia, R. K.; Howell, H. B.; Knuteson, R. O.; Martin, G. D.; Olson, E. R.; Smuga-Otto, M. J.

2006-08-01

Future satellite weather instruments such as high spectral resolution imaging interferometers pose a challenge to the atmospheric science and software development communities due to the immense data volumes they will generate. An open-source, scalable reference software implementation demonstrating the calibration of radiance products from an imaging interferometer, the Geosynchronous Imaging Fourier Transform Spectrometer1 (GIFTS), is presented. This paper covers essential design principles laid out in summary system diagrams, lessons learned during implementation and preliminary test results from the GIFTS Information Processing System (GIPS) prototype.

Dual-Stage Crosslinking of a Gel-Phase Bioink Improves Cell Viability and Homogeneity for 3D Bioprinting.

PubMed

Dubbin, Karen; Hori, Yuki; Lewis, Kazuomori K; Heilshorn, Sarah C

2016-10-01

Current bioinks for cell-based 3D bioprinting are not suitable for technology scale-up due to the challenges of cell sedimentation, cell membrane damage, and cell dehydration. A novel bioink hydrogel is presented with dual-stage crosslinking specifically designed to overcome these three major hurdles. This bioink enables the direct patterning of highly viable, multicell type constructs with long-term spatial fidelity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interactive target tracking for persistent wide-area surveillance

NASA Astrophysics Data System (ADS)

Ersoy, Ilker; Palaniappan, Kannappan; Seetharaman, Guna S.; Rao, Raghuveer M.

2012-06-01

Persistent aerial surveillance is an emerging technology that can provide continuous, wide-area coverage from an aircraft-based multiple-camera system. Tracking targets in these data sets is challenging for vision algorithms due to large data (several terabytes), very low frame rate, changing viewpoint, strong parallax and other imperfections due to registration and projection. Providing an interactive system for automated target tracking also has additional challenges that require online algorithms that are seamlessly integrated with interactive visualization tools to assist the user. We developed an algorithm that overcomes these challenges and demonstrated it on data obtained from a wide-area imaging platform.

An unexpected diagnosis of human immunodeficiency virus-2 infection in an overseas visitor: a case report.

PubMed

Sohail, Asma; Van Leer, Lyndal; Holmes, Natasha

2017-03-04

Human immunodeficiency virus 2 infection is endemic in West Africa but is also found in parts of Europe, North and South America, and India where it is thought to have been introduced secondary to migration and commercial trade ties. It is less common than Human immunodeficiency virus 1, with differences in pathogenicity, lower rates of transmission, longer asymptomatic period and slower progression to acquired immunodeficiency syndrome. Human immunodeficiency virus 2 is also associated with diagnostic challenges given the lack of commercially available diagnostic tests, and management challenges given intrinsic resistance to many anti-retroviral therapies. We describe a case of a 65 year old South Indian female, visiting her family in Australia, who presented with weight loss, pancytopaenia and generalised lymphadenopathy on a background of newly diagnosed congestive cardiac failure. Multiple investigations were performed to elucidate the cause of her presentation, with the eventual unexpected diagnosis of human immunodeficiency virus 2. She was commenced on anti-retroviral treatment and made a remarkable recovery. We describe the challenges associated with diagnosis of human immunodeficiency virus 2 due to lack of commercially available diagnostics, as well as the treatment and management challenges including the fact that human immunodeficiency virus 2 is intrinsically resistant to non-nucleoside reverse transcriptase inhibitors. Human immunodeficiency virus 2 infection should be considered in patients who present with symptoms and signs that do not point towards a clear diagnosis, such as unexplained pancytopaenia or lymphadenopathy, and who have risk factors such as being from an endemic area or having had blood transfusions, especially prior to the commencement of blood-borne virus screening of blood donors.

The challenge of developmentally appropriate care: predictive genetic testing in young people for familial adenomatous polyposis.

PubMed

Duncan, Rony E; Gillam, Lynn; Savulescu, Julian; Williamson, Robert; Rogers, John G; Delatycki, Martin B

2010-03-01

Predictive genetic tests for familial adenomatous polyposis (FAP) are routinely offered to young people during early adolescence. While this is not controversial, due to the medical benefit conferred by the test, it is nonetheless challenging as a consequence of the stage of life of the young people, and the simultaneous involvement of multiple family members. Despite these challenges, it is possible to ensure that the test is offered in such a way that it actively acknowledges and facilitates young people's developing autonomy and psychosocial well-being. In this paper we present findings from ten in-depth interviews with young people who have undergone predictive genetic testing for FAP (four male, six female; five gene-positive, five gene-negative; aged 10-17 years at the time of their predictive test; aged 12-25 years at the time of their research interview). We present five themes that emerged from the interviews which highlight key ethical challenges associated with such testing. These are: (1) the significance of the test; (2) young people's lack of involvement in the decision to be tested; (3) young people's limited understanding; (4) provision of the blood test at the first visit; and (5) group testing of family members. We draw on these themes to make eight recommendations for future practice. Together, these recommendations highlight the importance of providing developmentally appropriate care to young people undergoing predictive genetic testing for FAP.

The problem is not just sample size: the consequences of low base rates in policing experiments in smaller cities.

PubMed

Hinkle, Joshua C; Weisburd, David; Famega, Christine; Ready, Justin

2013-01-01

Hot spots policing is one of the most influential police innovations, with a strong body of experimental research showing it to be effective in reducing crime and disorder. However, most studies have been conducted in major cities, and we thus know little about whether it is effective in smaller cities, which account for a majority of police agencies. The lack of experimental studies in smaller cities is likely in part due to challenges designing statistically powerful tests in such contexts. The current article explores the challenges of statistical power and "noise" resulting from low base rates of crime in smaller cities and provides suggestions for future evaluations to overcome these limitations. Data from a randomized experimental evaluation of broken windows policing in hot spots are used to illustrate the challenges that low base rates present for evaluating hot spots policing programs in smaller cities. Analyses show low base rates make it difficult to detect treatment effects. Very large effect sizes would be required to reach sufficient power, and random fluctuations around low base rates make detecting treatment effects difficult, irrespective of power, by masking differences between treatment and control groups. Low base rates present strong challenges to researchers attempting to evaluate hot spots policing in smaller cities. As such, base rates must be taken directly into account when designing experimental evaluations. The article offers suggestions for researchers attempting to expand the examination of hot spots policing and other microplace-based interventions to smaller jurisdictions.

Riddle Me This: Acalculous Cholecystitis as an Unusual Complication of Immunoglobulin M Negative Mononucleosis.

PubMed

Höhn, Philipp; Braumann, Chris; Uhl, Waldemar; Luu, Andreas M

2018-04-19

Infectious mononucleosis is a common disease of the adolescent caused by the Epstein-Barr virus (EBV). We present a rare case of a male adult with acalculous cholecystitis due to infectious mononucleosis. A correct diagnosis was challenging due to a false negative antibody test. Laboratory values were significant for a marked lymphocytosis and an early Immunoglobulin G (IgG) response without initial Immunoglobulin M (IgM) elevation. However, IgM antibodies were elevated two weeks later. Symptoms resolved quickly under symptomatic therapy. Antibody level patterns in asplenic patients with infectious mononucleosis are characterized by an atypical course with a delayed rise in IgM antibodies, which complicates the correct diagnosis of an EBV-induced acalculous cholecystitis.

Case of relentless chronic phase of chronic myeloid leukaemia.

PubMed

Chan, Onyee; Chen, Hao; Krishnadasan, Ravitharan; Anwer, Faiz

2016-06-22

Initial treatment of chronic phase chronic myeloid leukaemia is straightforward in today's era of tyrosine kinase inhibitors. However, managing refractory cases remain a major challenge due to the multiple factors that can influence decision-making, including medication tolerance, disease burden, mutation status, comorbidities, availability of donor, and fitness for an ablative conditioning. We report a male patient presenting with chronic phase chronic myeloid leukaemia who was treated with 5 different tyrosine kinase inhibitors either due to intolerance and/or failed response. He subsequently received 2 haploidentical haematopoietic stem cells transplants before achieving complete remission. This case highlights various treatment options, need for vigilant disease monitoring, and the possibility of complete positive response even after many lines of therapy failure. 2016 BMJ Publishing Group Ltd.

Orthostatic hypotension as an unusual clinical manifestation of pheochromocytoma: a case report.

PubMed

Bortnik, Miriam; Occhetta, Eraldo; Marino, Paolo

2008-08-01

Pheochromocytoma is a rare endocrine tumor which can have a highly variable presentation related to increased catecholamine secretion. We report the case of a 74-year-old man in whom recurrent episodes of syncope due to orthostatic hypotension were the only clinical manifestations of this challenging entity. Diagnosis of pheochromocytoma was achieved by biochemical test samples and computed tomography scans. Surgical excision of the tumor resulted in clinical improvement with normalization of catecholamine concentrations and no more episodes of orthostatic hypotension during a follow-up of 24 months. Although rare, pheochromocytoma may frequently cause disorders of orthostatic tolerance; because of its meaningful implications, screening for this entity should be considered in case of recurrent syncopal episodes due to new-onset orthostatic hypotension.

Intranasal tooth: ectopic eruption 1 year after maxillofacial trauma

PubMed Central

Agrawal, Mamta; Khan, Tayyeb Sultan; Gupta, Tulika; Khanna, Shally

2014-01-01

Injury to the permanent central incisors due to trauma in the maxillofacial region, though common, may result in an uncommon sequel. We report a case of traumatic injury in a 5-year-old child with displacement of the tooth bud into the nasal floor. The identification of ectopic tooth buds poses little diagnostic challenge due to the available imaging facilities, however, in the present case the ectopic bud remained unnoticed and resulted in ectopic eruption of the tooth in the nasal cavity 1 year later. This report highlights a rare case of nasal eruption of a permanent tooth and places stress on the need for close attention to detail during maxillofacial trauma for early detection and proper management. PMID:25103317

Intranasal tooth: ectopic eruption 1 year after maxillofacial trauma.

PubMed

Agrawal, Mamta; Khan, Tayyeb Sultan; Gupta, Tulika; Khanna, Shally

2014-08-06

Injury to the permanent central incisors due to trauma in the maxillofacial region, though common, may result in an uncommon sequel. We report a case of traumatic injury in a 5-year-old child with displacement of the tooth bud into the nasal floor. The identification of ectopic tooth buds poses little diagnostic challenge due to the available imaging facilities, however, in the present case the ectopic bud remained unnoticed and resulted in ectopic eruption of the tooth in the nasal cavity 1 year later. This report highlights a rare case of nasal eruption of a permanent tooth and places stress on the need for close attention to detail during maxillofacial trauma for early detection and proper management. 2014 BMJ Publishing Group Ltd.

Recent Advances of Rare-Earth Ion Doped Luminescent Nanomaterials in Perovskite Solar Cells

PubMed Central

Qiao, Yu; Li, Shuhan; Liu, Wenhui; Ran, Meiqing; Lu, Haifei

2018-01-01

Organic-inorganic lead halide based perovskite solar cells have received broad interest due to their merits of low fabrication cost, a low temperature solution process, and high energy conversion efficiencies. Rare-earth (RE) ion doped nanomaterials can be used in perovskite solar cells to expand the range of absorption spectra and improve the stability due to its upconversion and downconversion effect. This article reviews recent progress in using RE-ion-doped nanomaterials in mesoporous electrodes, perovskite active layers, and as an external function layer of perovskite solar cells. Finally, we discuss the challenges facing the effective use of RE-ion-doped nanomaterials in perovskite solar cells and present some prospects for future research. PMID:29342950

[Preclinical treatment of severe burn trauma due to an electric arc on an overhead railway cable].

PubMed

Spelten, O; Wetsch, W A; Hinkelbein, J

2013-09-01

Severe burns due to electrical accidents occur rarely in Germany but represent a challenge for emergency physicians and their team. Apart from extensive burns cardiac arrhythmia, neurological damage caused by electric current and osseous injury corresponding to the trauma mechanism are also common. It is important to perform a survey of the pattern of injuries and treat acute life-threatening conditions immediately in the field. Furthermore, specific conditions related to burns must be considered, e.g. fluid resuscitation, thermal management and analgesia. In addition, a correct strategy for further medical care in an appropriate hospital is essential. Exemplified by this case guidelines for the treatment of severe burns and typical pitfalls are presented.

Evaluation and optimization of microbial DNA extraction from fecal samples of wild Antarctic bird species

PubMed Central

Eriksson, Per; Mourkas, Evangelos; González-Acuna, Daniel; Olsen, Björn; Ellström, Patrik

2017-01-01

ABSTRACT Introduction: Advances in the development of nucleic acid-based methods have dramatically facilitated studies of host–microbial interactions. Fecal DNA analysis can provide information about the host’s microbiota and gastrointestinal pathogen burden. Numerous studies have been conducted in mammals, yet birds are less well studied. Avian fecal DNA extraction has proved challenging, partly due to the mixture of fecal and urinary excretions and the deficiency of optimized protocols. This study presents an evaluation of the performance in avian fecal DNA extraction of six commercial kits from different bird species, focusing on penguins. Material and methods: Six DNA extraction kits were first tested according to the manufacturers’ instructions using mallard feces. The kit giving the highest DNA yield was selected for further optimization and evaluation using Antarctic bird feces. Results: Penguin feces constitute a challenging sample type: most of the DNA extraction kits failed to yield acceptable amounts of DNA. The QIAamp cador Pathogen kit (Qiagen) performed the best in the initial investigation. Further optimization of the protocol resulted in good yields of high-quality DNA from seven bird species of different avian orders. Conclusion: This study presents an optimized approach to DNA extraction from challenging avian fecal samples. PMID:29152162

Terabit Wireless Communication Challenges

NASA Technical Reports Server (NTRS)

Hwu, Shian U.

2012-01-01

This presentation briefly discusses a research effort on Terabit Wireless communication systems for possible space applications. Recently, terahertz (THz) technology (300-3000 GHz frequency) has attracted a great deal of interest from academia and industry. This is due to a number of interesting features of THz waves, including the nearly unlimited bandwidths available, and the non-ionizing radiation nature which does not damage human tissues and DNA with minimum health threat. Also, as millimeter-wave communication systems mature, the focus of research is, naturally, moving to the THz range. Many scientists regard THz as the last great frontier of the electromagnetic spectrum, but finding new applications outside the traditional niches of radio astronomy, Earth and planetary remote sensing, and molecular spectroscopy particularly in biomedical imaging and wireless communications has been relatively slow. Radiologists find this area of study so attractive because t-rays are non-ionizing, which suggests no harm is done to tissue or DNA. They also offer the possibility of performing spectroscopic measurements over a very wide frequency range, and can even capture signatures from liquids and solids. According to Shannon theory, the broad bandwidth of the THz frequency bands can be used for terabit-per-second (Tb/s) wireless communication systems. This enables several new applications, such as cell phones with 360 degrees autostereoscopic displays, optic-fiber replacement, and wireless Tb/s file transferring. Although THz technology could satisfy the demand for an extremely high data rate, a number of technical challenges need to be overcome before its development. This presentation provides an overview the state-of-the- art in THz wireless communication and the technical challenges for an emerging application in Terabit wireless systems. The main issue for THz wave propagation is the high atmospheric attenuation, which is dominated by water vapor absorption in the THz frequency band. The technical challenges in design such a system and the techniques to overcome the challenges will be discussed in this presentation.

Recent advances in heterobimetallic catalysis across a "transition metal-tin" motif.

PubMed

Das, Debjit; Mohapatra, Swapna Sarita; Roy, Sujit

2015-06-07

Heterobimetallic catalysts, bearing a metal-metal bond between a transition metal (TM) and a tin atom, are very promising due to their ability in mediating a wide variety of organic transformations. Indeed the utilization of such catalysts is a challenging and evolving area in the field of homogeneous catalysis. Catalysis across a 'TM-Sn' motif is an emerging area in the broader domain of multimetallic catalysis. The present review apprises the chemists' community of the past, present and future scope of this versatile catalytic motif. The TM-Sn catalyzed reactions presented include, among others, Friedel-Crafts alkylation, carbonylation, polymerization, cyclization, olefin metathesis, Heck coupling, hydroarylation Michael addition and tandem coupling. The mechanistic aspects of the reactions have been highlighted as well.

Central nervous system lymphoma presenting as trigeminal neuralgia: A diagnostic challenge

PubMed Central

Ang, Jensen W. J.; Khanna, Arjun; Walcott, Brian P.; Kahle, Kristopher T.; Eskandar, Emad N.

2015-01-01

We describe an atypical man with diffuse large B cell lymphoma localized to the sphenoid wing and adjacent cavernous sinus, initially presenting with isolated ipsilateral facial pain mimicking trigeminal neuralgia due to invasion of Meckel’s cave but subsequently progressing to intra-axial extension and having synchronous features of systemic lymphoma. Primary central nervous system lymphoma is uncommon, accounting for approximately 2% of all primary intra-cranial tumors, but its incidence has been steadily increasing in some groups [1]. It usually arises in periventricular cerebral white matter, reports of lymphoma in extra-axial regions are rare [2]. This man highlights the importance of maintaining lymphoma in the differential diagnosis of tumors of the skull base presenting with trigeminal neuralgia-like symptoms. PMID:25865026

Anthropogenic wetlands due to over-irrigation of desert areas; A challenging hydrogeological investigation with extensive geophysical input

NASA Astrophysics Data System (ADS)

Behroozmand, A. A.; Teatini, P.; Pedersen, J. B. B.; Auken, E.; Tosatto, O.; Christiansen, A. V.

2015-12-01

During the last century, many large irrigation projects have been initiated in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in form of waterlogging. As results, large volumes of water are lost due to surplus irrigation in regions where water availability is extremely challenging for both population survival and economic development. The Nubariya depression, Western Desert (Egypt), is a clear example of this mechanism. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated lake developed in the area in the late 1990s and presently extends for about 2.5 km2. Available data provide evidence of a simultaneous general deterioration of the groundwater system. With the main objectives of understanding the hydrological evolution of the area, characterizing the hydrogeological setting and developing scenarios for artificial aquifer remediation and recharge, an extensive hydrogeophysical investigation was carried out in this challenging environment using Magnetic Resonance Sounding (MRS, also called surface NMR) and ground-based Transient EM (TEM). The integrated interpretation of the geophysical surveys, properly calibrated with a number of boreholes, provides a clear hydrogeological picture of the upper 100 m sedimentary structure, in terms of both lithology and groundwater quality. The information is then used to set up a regional groundwater flow and a local density-dependent flow and transport numerical model to reproduce the past evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated waters provided by a nearby waste-water treatment plant. The research outcomes point the hydrological challenges that emerge for an effective management of water resources in reclaimed desert areas and highlight the effectiveness of integrating advanced geophysical and modeling methodologies.

Ecosystem services provided by a complex coastal region: challenges of classification and mapping.

PubMed

Sousa, Lisa P; Sousa, Ana I; Alves, Fátima L; Lillebø, Ana I

2016-03-11

A variety of ecosystem services classification systems and mapping approaches are available in the scientific and technical literature, which needs to be selected and adapted when applied to complex territories (e.g. in the interface between water and land, estuary and sea). This paper provides a framework for addressing ecosystem services in complex coastal regions. The roadmap comprises the definition of the exact geographic boundaries of the study area; the use of CICES (Common International Classification of Ecosystem Services) for ecosystem services identification and classification; and the definition of qualitative indicators that will serve as basis to map the ecosystem services. Due to its complexity, the Ria de Aveiro coastal region was selected as case study, presenting an opportunity to explore the application of such approaches at a regional scale. The main challenges of implementing the proposed roadmap, together with its advantages are discussed in this research. The results highlight the importance of considering both the connectivity of natural systems and the complexity of the governance framework; the flexibility and robustness, but also the challenges when applying CICES at regional scale; and the challenges regarding ecosystem services mapping.

Design of a framework for modeling, integration and simulation of physiological models.

PubMed

Erson, E Zeynep; Cavuşoğlu, M Cenk

2012-09-01

Multiscale modeling and integration of physiological models carry challenges due to the complex nature of physiological processes. High coupling within and among scales present a significant challenge in constructing and integrating multiscale physiological models. In order to deal with such challenges in a systematic way, there is a significant need for an information technology framework together with related analytical and computational tools that will facilitate integration of models and simulations of complex biological systems. Physiological Model Simulation, Integration and Modeling Framework (Phy-SIM) is an information technology framework providing the tools to facilitate development, integration and simulation of integrated models of human physiology. Phy-SIM brings software level solutions to the challenges raised by the complex nature of physiological systems. The aim of Phy-SIM, and this paper is to lay some foundation with the new approaches such as information flow and modular representation of the physiological models. The ultimate goal is to enhance the development of both the models and the integration approaches of multiscale physiological processes and thus this paper focuses on the design approaches that would achieve such a goal. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Metastable Metal Hydrides for Hydrogen Storage

DOE PAGES

Graetz, Jason

2012-01-01

The possibility of using hydrogen as a reliable energy carrier for both stationary and mobile applications has gained renewed interest in recent years due to improvements in high temperature fuel cells and a reduction in hydrogen production costs. However, a number of challenges remain and new media are needed that are capable of safely storing hydrogen with high gravimetric and volumetric densities. Metal hydrides and complex metal hydrides offer some hope of overcoming these challenges; however, many of the high capacity “reversible” hydrides exhibit a large endothermic decomposition enthalpy making it difficult to release the hydrogen at low temperatures. Onmore » the other hand, the metastable hydrides are characterized by a low reaction enthalpy and a decomposition reaction that is thermodynamically favorable under ambient conditions. The rapid, low temperature hydrogen evolution rates that can be achieved with these materials offer much promise for mobile PEM fuel cell applications. However, a critical challenge exists to develop new methods to regenerate these hydrides directly from the reactants and hydrogen gas. This spotlight paper presents an overview of some of the metastable metal hydrides for hydrogen storage and a few new approaches being investigated to address the key challenges associated with these materials.« less

Ecosystem services provided by a complex coastal region: challenges of classification and mapping

PubMed Central

Sousa, Lisa P.; Sousa, Ana I.; Alves, Fátima L.; Lillebø, Ana I.

2016-01-01

A variety of ecosystem services classification systems and mapping approaches are available in the scientific and technical literature, which needs to be selected and adapted when applied to complex territories (e.g. in the interface between water and land, estuary and sea). This paper provides a framework for addressing ecosystem services in complex coastal regions. The roadmap comprises the definition of the exact geographic boundaries of the study area; the use of CICES (Common International Classification of Ecosystem Services) for ecosystem services identification and classification; and the definition of qualitative indicators that will serve as basis to map the ecosystem services. Due to its complexity, the Ria de Aveiro coastal region was selected as case study, presenting an opportunity to explore the application of such approaches at a regional scale. The main challenges of implementing the proposed roadmap, together with its advantages are discussed in this research. The results highlight the importance of considering both the connectivity of natural systems and the complexity of the governance framework; the flexibility and robustness, but also the challenges when applying CICES at regional scale; and the challenges regarding ecosystem services mapping. PMID:26964892

Systems metabolic engineering of microorganisms to achieve large-scale production of flavonoid scaffolds.

PubMed

Wu, Junjun; Du, Guocheng; Zhou, Jingwen; Chen, Jian

2014-10-20

Flavonoids possess pharmaceutical potential due to their health-promoting activities. The complex structures of these products make extraction from plants difficult, and chemical synthesis is limited because of the use of many toxic solvents. Microbial production offers an alternate way to produce these compounds on an industrial scale in a more economical and environment-friendly manner. However, at present microbial production has been achieved only on a laboratory scale and improvements and scale-up of these processes remain challenging. Naringenin and pinocembrin, which are flavonoid scaffolds and precursors for most of the flavonoids, are the model molecules that are key to solving the current issues restricting industrial production of these chemicals. The emergence of systems metabolic engineering, which combines systems biology with synthetic biology and evolutionary engineering at the systems level, offers new perspectives on strain and process optimization. In this review, current challenges in large-scale fermentation processes involving flavonoid scaffolds and the strategies and tools of systems metabolic engineering used to overcome these challenges are summarized. This will offer insights into overcoming the limitations and challenges of large-scale microbial production of these important pharmaceutical compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Emergency mapping and information management during Nepal Earthquake 2015 - Challenges and lesson learned

NASA Astrophysics Data System (ADS)

Joshi, G.; Gurung, D. R.

2016-12-01

A powerful 7.8 magnitude earthquake struck Nepal at 06:11 UTC on 25 April 2015. Several subsequent aftershocks were deadliest earthquake in recent history of Nepal. In total about 9000 people died and 22,300 people were injured, and lives of eight million people, almost one-third of the population of Nepal was effected. The event lead to massive campaigned to gather data and information on damage and loss using remote sensing, field inspection, and community survey. Information on distribution of relief materials is other important domain of information necessary for equitable relief distribution. Pre and post-earthquake high resolution satellite images helped in damage area assessment and mapping. Many national and international agencies became active to generate and fill the information vacuum. The challenges included data access bottleneck due to lack of good IT infrastructure; inconsistent products due to absence of standard mapping guidelines; dissemination challenges due to absence of Standard Operating Protocols and single information gateway. These challenges were negating opportunities offered by improved earth observation data availability, increasing engagement of volunteers for emergency mapping, and centralized emergency coordination practice. This paper highlights critical practical challenges encountered during emergency mapping and information management during the earthquake in Nepal. There is greater need to address such challenges to effectively use technological leverages that recent advancement in space science, IT and mapping domain provides.

The Effects of Authentic Vision Statement on Challenges Experienced by First Year Superintendents

ERIC Educational Resources Information Center

Erdos, Monica

2011-01-01

A new superintendent in a new school district (NSND) can be a challenging position. The literature review asserts that many challenges faced by NSNDs are due to the absence of a shared vision. Challenges can be listed as work stoppage, personnel, financial, fighting ghosts, homecoming procession and many other aspects of running a district.…

Stresses and Challenges for New Graduates in Hospitals.

ERIC Educational Resources Information Center

Oermann, Marilyn H.; Garvin, Michael F.

2002-01-01

Recent nursing graduates (n=46) rated stresses and challenges in clinical practice. Stressors included not feeling competent/confident, making mistakes due to increased workload, and encountering new situations. Challenges included applying knowledge to practice and acquiring new skills. Most emotions were positive but anxiety was frequent. Ways…

Reconciling Scale Mismatch in Water Governance, Hydro-climatic Processes and Infrastructure Systems of Water Supply in Las Vegas

NASA Astrophysics Data System (ADS)

Garcia, M. E.; Alarcon, T.; Portney, K.; Islam, S.

2013-12-01

Water resource systems are a classic example of a common pool resource due to the high cost of exclusion and the subtractability of the resource; for common pool resources, the performance of governance systems primarily depends on how well matched the institutional arrangements and rules are to the biophysical conditions and social norms. Changes in water governance, hydro-climatic processes and infrastructure systems occur on disparate temporal and spatial scales. A key challenge is the gap between current climate change model resolution, and the spatial and temporal scale of urban water supply decisions. This gap will lead to inappropriate management policies if not mediated through a carefully crafted decision making process. Traditional decision support and planning methods (DSPM) such as classical decision analysis are not equipped to deal with a non-static climate. While emerging methods such as decision scaling, robust decision making and real options are designed to deal with a changing climate, governance systems have evolved under the assumption of a static climate and it is not clear if these methods are well suited to the existing governance regime. In our study, these questions are contextualized by examining an urban water utility that has made significant changes in policy to adapt to changing conditions: the Southern Nevada Water Authority (SNWA) which serves metropolitan Las Vegas. Like most desert cities, Las Vegas exists because of water; the artesian springs of the Las Vegas Valley once provided an ample water supply for Native Americans, ranchers and later a small railroad city. However, population growth has increased demands far beyond local supplies. The area now depends on the Colorado River for the majority of its water supply. Natural climate variability with periodic droughts has further challenged water providers; projected climate changes and further population growth will exacerbate these challenges. Las Vegas is selected as a case study due to the combined challenges of population growth and climate change, common in the arid west, and due its cooperative institutional response to these challenges, unprecedented in the arid west. To begin to disentangle this question we have analyzed the institutional arrangements and rules which govern water decision making in the Las Vegas Valley and evaluated the existing DSPM used by the SNWA and partner utilities. Presented here are the preliminary results from an ongoing project.

Radio-frequency flexible and stretchable electronics: the need, challenges and opportunities

NASA Astrophysics Data System (ADS)

Jung, Yei Hwan; Seo, Jung-Hun; Zhang, Huilong; Lee, Juhwan; Cho, Sang June; Chang, Tzu-Hsuan; Ma, Zhenqiang

2017-05-01

Successful integration of ultrathin flexible or stretchable systems with new applications, such as medical devices and biodegradable electronics, have intrigued many researchers and industries around the globe to seek materials and processes to create high-performance, non-invasive and cost-effective electronics to match those of state-of-the-art devices. Nevertheless, the crucial concept of transmitting data or power wirelessly for such unconventional devices has been difficult to realize due to limitations of radio-frequency (RF) electronics in individual components that form a wireless circuitry, such as antenna, transmission line, active devices, passive devices etc. To overcome such challenges, these components must be developed in a step-by-step manner, as each component faces a number of different challenges in ultrathin formats. Here, we report on materials and design considerations for fabricating flexible and stretchable electronics systems that operate in the microwave level. High-speed flexible active devices, including cost effective Si-based strained MOSFETs, GaAs-based HBTs and GaN-based HEMTs, performing at multi-gigahertz frequencies are presented. Furthermore, flexible or stretchable passive devices, including capacitors, inductors and transmission lines that are vital parts of a microwave circuitry are also demonstrated. We also present unique applications using the presented flexible or stretchable RF components, including wearable RF electronics and biodegradable RF electronics, which were impossible to achieve using conventional rigid, wafer-based technology. Further opportunities like implantable systems exist utilizing such ultrathin RF components, which are discussed in this report as well.

Trend analyses in the health behaviour in school-aged children study: methodological considerations and recommendations.

PubMed

Schnohr, Christina W; Molcho, Michal; Rasmussen, Mette; Samdal, Oddrun; de Looze, Margreet; Levin, Kate; Roberts, Chris J; Ehlinger, Virginie; Krølner, Rikke; Dalmasso, Paola; Torsheim, Torbjørn

2015-04-01

This article presents the scope and development of the Health Behaviour in School-aged Children (HBSC) study, reviews trend papers published on international HBSC data up to 2012 and discusses the efforts made to produce reliable trend analyses. The major goal of this article is to present the statistical procedures and analytical strategies for upholding high data quality, as well as reflections from the authors of this article on how to produce reliable trends based on an international study of the magnitude of the HBSC study. HBSC is an international cross-sectional study collecting data from adolescents aged 11-15 years, on a broad variety of health determinants and health behaviours. A number of methodological challenges have stemmed from the growth of the HBSC-study, in particular given that the study has a focus on monitoring trends. Some of those challenges are considered. When analysing trends, researchers must be able to assess whether a change in prevalence is an expression of an actual change in the observed outcome, whether it is a result of methodological artefacts, or whether it is due to changes in the conceptualization of the outcome by the respondents. The article present recommendations to take a number of the considerations into account. The considerations imply methodological challenges, which are core issues in undertaking trend analyses. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Global impacts of U.S. bioenergy production and policy: A general equilibrium perspective

NASA Astrophysics Data System (ADS)

Evans, Samuel Garner

The conversion of biomass to energy represents a promising pathway forward in efforts to reduce fossil fuel use in the transportation and electricity sectors. In addition to potential benefits, such as greenhouse gas reductions and increased energy security, bioenergy production also presents a unique set of challenges. These challenges include tradeoffs between food and fuel production, distortions in energy markets, and terrestrial emissions associated with changing land-use patterns. Each of these challenges arises from market-mediated responses to bioenergy production, and are therefore largely economic in nature. This dissertation directly addresses these opportunities and challenges by evaluating the economic impacts of U.S. bioenergy production and policy, focusing on both existing and future biomass-to-energy pathways. The analysis approaches the issue from a global, economy-wide perspective, reflecting two important facts. First, that large-scale bioenergy production connects multiple sectors of the economy due to the use of agricultural land resources for biomass production, and competition with fossil fuels in energy markets. Second, markets for both agricultural and energy commodities are highly integrated globally, causing domestic policies to have international effects. The reader can think of this work as being comprised of three parts. Part I provides context through an extensive review of the literature on the market-mediated effects of conventional biofuel production (Chapter 2) and develops a general equilibrium modeling framework for assessing the extent to which these phenomenon present a challenge for future bioenergy pathways (Chapter 3). Part II (Chapter 4) explores the economic impacts of the lignocellulosic biofuel production targets set in the U.S. Renewable Fuel Standard on global agricultural and energy commodity markets. Part III (Chapter 5) extends the analysis to consider potential inefficiencies associated with policy-induced competition for biomass between the electricity and transportation fuel sectors.

Executing SPARQL Queries over the Web of Linked Data

NASA Astrophysics Data System (ADS)

Hartig, Olaf; Bizer, Christian; Freytag, Johann-Christoph

The Web of Linked Data forms a single, globally distributed dataspace. Due to the openness of this dataspace, it is not possible to know in advance all data sources that might be relevant for query answering. This openness poses a new challenge that is not addressed by traditional research on federated query processing. In this paper we present an approach to execute SPARQL queries over the Web of Linked Data. The main idea of our approach is to discover data that might be relevant for answering a query during the query execution itself. This discovery is driven by following RDF links between data sources based on URIs in the query and in partial results. The URIs are resolved over the HTTP protocol into RDF data which is continuously added to the queried dataset. This paper describes concepts and algorithms to implement our approach using an iterator-based pipeline. We introduce a formalization of the pipelining approach and show that classical iterators may cause blocking due to the latency of HTTP requests. To avoid blocking, we propose an extension of the iterator paradigm. The evaluation of our approach shows its strengths as well as the still existing challenges.

A challenging case of an ectopic cushing syndrome.

PubMed

Menezes Nunes, Joana; Pinho, Elika; Camões, Isabel; Maciel, João; Cabral Bastos, Pedro; Souto de Moura, Conceição; Bettencourt, Paulo

2014-01-01

Bronchopulmonary carcinoids are rare pulmonary neoplasms although they account for most cases of ectopic ACTH syndromes. When feasible, the mainstay treatment is surgical resection of the tumor. We report the case of a 52-year-old woman with signs and symptoms suggestive of hypercortisolism for 12 months, admitted to our department because of community acquired pneumonia. Blood hormone analysis showed increased levels of ACTH and urinary free cortisol and nonsuppressibility to high- and low-dose dexamethasone tests. Pituitary MRI showed no lesion and no central-to-peripheral ACTH gradient was present in bilateral inferior petrosal sinus sampling. CRH stimulation test suggested an ectopic ACTH source. Thoracic CT scan revealed a nodular region measuring 12 mm located in the inferior lingular lobule of the left superior lung with negative uptake by (18)-FDG-PET scan and negative SRS. The patient was successfully treated with an atypical lung resection and histology revealed an atypical bronchial carcinoid tumor with positive ACTH immunoreactivity. This was an interesting case because the patient was admitted due to pneumonia that may have been associated with her untreated and chronic hypercortisolism and a challenging case of ectopic ACTH syndrome due to conflicting results on the diagnostic exams.

Surgical approach to end-stage heart failure.

PubMed

Klotz, Stefan; Scheld, Hans H

2011-02-01

End-stage heart failure is a challenging disease with growing incidence. With decreasing heart transplant rates worldwide organ preserving therapies become, again, of interest. The purpose of the present review is to examine the potential challenges of surgical therapies in patients with end-stage heart failure. The gold-standard for end-stage heart failure is and will be cardiac transplantation. However, due to organ shortage this therapy is limited to a few patients. Therefore implantation of ventricular assist devices (VADs) or long-term minimal-invasive partial support devices will increase. Improvements in device design with smaller devices, easier implantation techniques, and modified anticoagulation outcome and long-term success will likely improve. In addition, good quality of life as destination therapy is almost available. Organ conservation surgery (coronary artery bypass grafting and surgical ventricular restoration or surgical repair of mitral valve regurgitation) in end-stage heart failure patients could not prove the expected results. Transcatheter or minimal-invasive approaches of these therapies might become routine in the near future. Due to the overwhelming outcome rates, cardiac transplantation is the most established surgical therapy for end-stage heart failure. VAD therapy is increasing and minimized VADs might further open the market for destination therapy/permanent support.

Emulating Many-Body Localization with a Superconducting Quantum Processor

NASA Astrophysics Data System (ADS)

Xu, Kai; Chen, Jin-Jun; Zeng, Yu; Zhang, Yu-Ran; Song, Chao; Liu, Wuxin; Guo, Qiujiang; Zhang, Pengfei; Xu, Da; Deng, Hui; Huang, Keqiang; Wang, H.; Zhu, Xiaobo; Zheng, Dongning; Fan, Heng

2018-02-01

The law of statistical physics dictates that generic closed quantum many-body systems initialized in nonequilibrium will thermalize under their own dynamics. However, the emergence of many-body localization (MBL) owing to the interplay between interaction and disorder, which is in stark contrast to Anderson localization, which only addresses noninteracting particles in the presence of disorder, greatly challenges this concept, because it prevents the systems from evolving to the ergodic thermalized state. One critical evidence of MBL is the long-time logarithmic growth of entanglement entropy, and a direct observation of it is still elusive due to the experimental challenges in multiqubit single-shot measurement and quantum state tomography. Here we present an experiment fully emulating the MBL dynamics with a 10-qubit superconducting quantum processor, which represents a spin-1 /2 X Y model featuring programmable disorder and long-range spin-spin interactions. We provide essential signatures of MBL, such as the imbalance due to the initial nonequilibrium, the violation of eigenstate thermalization hypothesis, and, more importantly, the direct evidence of the long-time logarithmic growth of entanglement entropy. Our results lay solid foundations for precisely simulating the intriguing physics of quantum many-body systems on the platform of large-scale multiqubit superconducting quantum processors.

Therapeutic Potential of Thymoquinone in Glioblastoma Treatment: Targeting Major Gliomagenesis Signaling Pathways

PubMed Central

Chowdhury, Fabliha Ahmed; Hossain, Md Kamal; Mostofa, A. G. M.; Akbor, Maruf Mohammad

2018-01-01

Glioblastoma multiforme (GBM) is one of the most devastating brain tumors with median survival of one year and presents unique challenges to therapy because of its aggressive behavior. Current treatment strategy involves surgery, radiotherapy, immunotherapy, and adjuvant chemotherapy even though optimal management requires a multidisciplinary approach and knowledge of potential complications from both the disease and its treatment. Thymoquinone (TQ), the main bioactive component of Nigella sativa L., has exhibited anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteract carcinogenesis, malignant growth, invasion, migration, and angiogenesis. TQ can specifically sensitize tumor cells towards conventional cancer treatments and minimize therapy-associated toxic effects in normal cells. Its potential to enter brain via nasal pathway due to volatile nature of TQ adds another advantage in overcoming blood-brain barrier. In this review, we summarized the potential role of TQ in different signaling pathways in GBM that have undergone treatment with standard therapeutic modalities or with TQ. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical level to delineate its implied utility as novel therapeutics to combat the challenges for the treatment of GBM. PMID:29651429

Challenges in the assessment of total fluid intake in children and adolescents: a discussion paper.

PubMed

Warren, Janet; Guelinckx, Isabelle; Livingstone, Barbara; Potischman, Nancy; Nelson, Michael; Foster, Emma; Holmes, Bridget

2018-06-01

In recent years, evidence has emerged about the importance of healthy fluid intake in children for physical and mental performance and health, and in the prevention of obesity. Accurate data on water intake are needed to inform researchers and policymakers and for setting dietary reference values. However, to date, there are few published data on fluid or water intakes in children. This is due partly to the fact that drinking water is not always reported in dietary surveys. The aim of this paper is to review the current status of the literature and highlight the challenges of assessing total fluid intake in children and adolescents. From the dietary assessment literature it is apparent that children present unique challenges to assessing intake due to ongoing cognitive capacity development, limited literacy skills, difficulties in estimating portion sizes and multiple caregivers during any 1 day making it difficult to track intakes. As such, many issues should be considered when assessing total fluid intakes in children or adolescents. Various methods to assess fluid intakes exist, each with its own strengths and weaknesses; the ultimate choice of method depends on the research question and resources available. Based on the literature review, it is apparent that if the research focus is to assess only fluid intake, a fluid-specific method, such as a diary or record, appears to be a feasible approach to provide an accurate estimate of intakes.

Recent Updates on Novel Approaches in Insulin Drug Delivery: A Review of Challenges and Pharmaceutical Implications.

PubMed

Pandey, Manisha; Choudhury, Hira; Yi, Cheah Xiao; Mun, Chen Wei; Ping, Goh Khang; Rou, Guee Xin; Singh, Bhalqish Jeet Kaur A/P Ambar Jeet; Jhee, Angel Ng Ann; Chin, Lee Kai; Kesharwani, Prashant; Gorain, Bapi; Hussain, Zahid

2018-05-22

Diabetes mellitus, a metabolic disorder of glucose metabolism, is mainly associated with insulin resistance to the body cells, or impaired production of insulin by the pancreatic β-cells. Insulin is mainly required to regulate glucose metabolism in type 1 diabetes mellitus patients; however, many patients with type 2 diabetes mellitus also require insulin, especially when their condition cannot be controlled solely by oral hypoglycemic agents. Hence, major researches are ongoing attempting to improve the delivery of insulin in order to make it more convenient to patients who experience side effects from the conventional treatment procedure or non-adherence to insulin regimen due to multiple comorbid conditions. Conventionally, insulin is administered via subcutaneous route which is also one of the sole reasons of patient's non-compliance due to the invasiveness of this method. Several attempts have been done to improve patient compliance, reduce side effects, improve delivery adherence, and to enhance pharmaceutical performance of the insulin therapy. Despite of facing substantial challenges in developing efficient delivery systems for insulin, vast researches have been carried out for the development of smart delivery systems to delivery insulin via ocular, buccal, pulmonary, oral, transdermal, as well as rectal routes. Therefore, the present review was aimed to overview the challenges encountered with the current insulin delivery systems and to summarize recent advancements in technology of various novel insulin delivery systems being discovered and introduced in the current market. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Developing the medicinal plants sector in northern India: challenges and opportunities

PubMed Central

Kala, Chandra Prakash; Dhyani, Pitamber Prasad; Sajwan, Bikram Singh

2006-01-01

The medicinal properties of plant species have made an outstanding contribution in the origin and evolution of many traditional herbal therapies. These traditional knowledge systems have started to disappear with the passage of time due to scarcity of written documents and relatively low income in these traditions. Over the past few years, however, the medicinal plants have regained a wide recognition due to an escalating faith in herbal medicine in view of its lesser side effects compared to allopathic medicine in addition the necessity of meeting the requirements of medicine for an increasing human population. Through the realization of the continuous erosion of traditional knowledge of plants used for medicine in the past and the renewed interest at the present time, a need existed to review this valuable knowledge of medicinal plants with the purpose of developing medicinal plants sectors across the different states in India. Our major objectives therefore were to explore the potential in medicinal plants resources, to understand the challenges and opportunities with the medicinal plants sector, and also to suggest recommendations based upon the present state of knowledge for the establishment and smooth functioning of the medicinal plants sector along with improving the living standards of the underprivileged communities. The review reveals that northern India harbors a rich diversity of valuable medicinal plants, and attempts are being made at different levels for sustainable utilization of this resource in order to develop the medicinal plants sector.

Hydrologic impacts of thawing permafrost—A review

USGS Publications Warehouse

Walvoord, Michelle Ann; Kurylyk, Barret L.

2016-01-01

Where present, permafrost exerts a primary control on water fluxes, flowpaths, and distribution. Climate warming and related drivers of soil thermal change are expected to modify the distribution of permafrost, leading to changing hydrologic conditions, including alterations in soil moisture, connectivity of inland waters, streamflow seasonality, and the partitioning of water stored above and below ground. The field of permafrost hydrology is undergoing rapid advancement with respect to multiscale observations, subsurface characterization, modeling, and integration with other disciplines. However, gaining predictive capability of the many interrelated consequences of climate change is a persistent challenge due to several factors. Observations of hydrologic change have been causally linked to permafrost thaw, but applications of process-based models needed to support and enhance the transferability of empirical linkages have often been restricted to generalized representations. Limitations stem from inadequate baseline permafrost and unfrozen hydrogeologic characterization, lack of historical data, and simplifications in structure and process representation needed to counter the high computational demands of cryohydrogeologic simulations. Further, due in part to the large degree of subsurface heterogeneity of permafrost landscapes and the nonuniformity in thaw patterns and rates, associations between various modes of permafrost thaw and hydrologic change are not readily scalable; even trajectories of change can differ. This review highlights promising advances in characterization and modeling of permafrost regions and presents ongoing research challenges toward projecting hydrologic and ecologic consequences of permafrost thaw at time and spatial scales that are useful to managers and researchers.

Complex functional and epithetic rehabilitation after ablation of recurrent retroauricular basal cell carcinoma – a case study

PubMed Central

Reich, Waldemar; Exner, Anika; Winter, Eileen; Al-Nawas, Bilal; Eckert, Alexander Walter

2017-01-01

The reconstruction of extended defects of the concha poses a complex challenge for plastic surgeons. In cases of subtotal ablation, an alternative method designed especially for elderly oncological patients consists of epithetic rehabilitation. However, inserting an implant-retained concha epithesis proves challenging in patients with antecedents of deep resections involving the mastoid process. In the present case study, we report on the long-term treatment course (2009–2017) of a 79-year-old male patient suffering from a recurrent basal cell carcinoma of the retroauricular region. Following tumor resection, along with lateral mastoidectomy, reconstruction, and adjuvant radiotherapy, functional and esthetic deficits primarily due to peripheral facial nerve palsy were successfully managed using a multistep procedure. The procedure was completed by inserting an implant-retained concha epithesis, resulting in improved quality of life. Due to prior lateral mastoidectomy, ultra-short implants (4 mm) were inserted, partially at atypical positions. For maintaining healthy periimplant soft tissue, aftercare comprised cold plasma treatment. This oncologic case demonstrates the therapeutic necessity of using a broad spectrum of reconstructive procedures, along with their limitations, in a critical anatomic region. Specific features include the presentation of a workflow using ultra-short implants in a compromised mastoid region. Surgeons should consider alternative implant positions in the event of any compromised mastoid process. A particular emphasis has been put on meticulous aftercare to preserve healthy periimplant soft tissues. PMID:29423354

Discovery of Species-selective and Resistance-breaking Anticholinesterase Insecticides for the Malaria Mosquito

PubMed Central

Carlier, Paul R.; Bloomquist, Jeffrey R.; Totrov, Max; Li, Jianyong

2017-01-01

Great reductions in malaria mortality have been accomplished in the last 15 years, in part due to the widespread roll-out of insecticide-treated bednets across sub-Saharan Africa. To date, these nets only employ pyrethroids, insecticides that target the voltage-gated sodium ion channel of the malaria vector, Anopheles gambiae. Due to the growing emergence of An. gambiae strains that are resistant to pyrethroids, there is an urgent need to develop new public health insecticides that engage a different target and possess low mammalian toxicity. In this review, we will describe efforts to develop highly species-specific and resistance-breaking inhibitors of An. gambiae acetylcholinesterase (AgAChE). These efforts have been greatly aided by advances in knowledge of the structure of the enzyme, and two major inhibitor design strategies have been explored. Since AgAChE possesses an unpaired Cys residue not present in mammalian AChE, a logical strategy to achieve selective inhibition involves design of compounds that could ligate that Cys. A second strategy involves the design of new molecules to target the catalytic serine of the enzyme. Here the challenge is not only to achieve high inhibition selectivity vs human AChE, but also to demonstrate toxicity to An. gambiae that carry the G119S resistance mutation of AgAChE. The advances made and challenges remaining will be presented. This review is part of the special issue “Insecticide Mode of Action: From Insect to Mammalian Toxicity. PMID:28176636

Laser heating challenges of high yield MagLIF targets

NASA Astrophysics Data System (ADS)

Slutz, Stephen; Sefkow, Adam; Vesey, Roger

2014-10-01

The MagLIF (Magnetized Liner Inertial Fusion) concept is predicted by numerical simulation to produce fusion yields of about 100 kJ, when driven by 25 MA from the existing Z accelerator [S. A. Slutz et al. Phys. Plasmas 17, 056303 (2010)] and much higher yields with future accelerators delivering higher currents [Slutz and Vesey PRL 108, 025003 (2012)]. The fuel must be heated before compression to obtain significant fusion yields due to the relatively slow implosion velocities (~ 100 km/s) of magnetically driven liners. Lasers provide a convenient means to accomplish this pre-compressional heating of the fusion fuel, but there are challenges. The laser must penetrate a foil covering the laser entrance hole and deposit 20-30 kJ within the ~1 cm length of the liner in fuel at 6-12 mg/cc. Such high densities could result in beam scattering due to refraction and laser plasma interactions. Numerical simulations of the laser heating process are presented, which indicate that energies as high as 30 kJ could be deposited in the fuel by using two laser pulses of different wavelengths. Simulations of this process will be presented as well of results for a MagLIF design for a potential new machine delivering 50 MA of current. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

Low temperature growth of Ga 1- xIn xP bulk crystals from InSb-rich melt

NASA Astrophysics Data System (ADS)

Gennett, A.; Lewis, D.; Dutta, P. S.

2010-04-01

Bulk growth of phosphorus and arsenic based ternary III-V semiconductor crystals using pseudo-binary melts such as GaP-InP, GaP-GaAs, AlAs-GaAs, etc. is significantly challenging due to the high vapor pressures of group V species in conjunction with slow growth rates and the need for melt replenishment and mixing during growth. Lowering the growth temperature is desirable such that the vapor pressures of P and As can be easily handled. Low growth temperatures could be achieved by using Ga or In rich solutions. However, this approach is less attractive for growing bulk crystals due to several experimental difficulties including sticking of the growth solution to the crucible wall and to the grown crystal, making it challenging for crystal extraction. Growth of ternary crystals from low temperature quaternary melts has been found to be attractive. In this paper, we will present a new method for the growth of Ga 1- xIn xP from InSb rich Ga 1- xIn xP ySb 1- y melts at low growth temperatures in the range of 800-1050 °C. Thermodynamic phase diagrams calculated at various temperatures using a Gibbs free energy minimization software and materials databases commercially available from Thermo-Calc software will be presented along with experimental validation for Ga 1- xIn xP crystals grown at 1000 °C.

Multi-scale sensitivity analysis of pile installation using DEM

NASA Astrophysics Data System (ADS)

Esposito, Ricardo Gurevitz; Velloso, Raquel Quadros; , Eurípedes do Amaral Vargas, Jr.; Danziger, Bernadete Ragoni

2017-12-01

The disturbances experienced by the soil due to the pile installation and dynamic soil-structure interaction still present major challenges to foundation engineers. These phenomena exhibit complex behaviors, difficult to measure in physical tests and to reproduce in numerical models. Due to the simplified approach used by the discrete element method (DEM) to simulate large deformations and nonlinear stress-dilatancy behavior of granular soils, the DEM consists of an excellent tool to investigate these processes. This study presents a sensitivity analysis of the effects of introducing a single pile using the PFC2D software developed by Itasca Co. The different scales investigated in these simulations include point and shaft resistance, alterations in porosity and stress fields and particles displacement. Several simulations were conducted in order to investigate the effects of different numerical approaches showing indications that the method of installation and particle rotation could influence greatly in the conditions around the numerical pile. Minor effects were also noted due to change in penetration velocity and pile-soil friction. The difference in behavior of a moving and a stationary pile shows good qualitative agreement with previous experimental results indicating the necessity of realizing a force equilibrium process prior to any load-test to be simulated.

Multi-scale sensitivity analysis of pile installation using DEM

NASA Astrophysics Data System (ADS)

Esposito, Ricardo Gurevitz; Velloso, Raquel Quadros; , Eurípedes do Amaral Vargas, Jr.; Danziger, Bernadete Ragoni

2018-07-01

The disturbances experienced by the soil due to the pile installation and dynamic soil-structure interaction still present major challenges to foundation engineers. These phenomena exhibit complex behaviors, difficult to measure in physical tests and to reproduce in numerical models. Due to the simplified approach used by the discrete element method (DEM) to simulate large deformations and nonlinear stress-dilatancy behavior of granular soils, the DEM consists of an excellent tool to investigate these processes. This study presents a sensitivity analysis of the effects of introducing a single pile using the PFC2D software developed by Itasca Co. The different scales investigated in these simulations include point and shaft resistance, alterations in porosity and stress fields and particles displacement. Several simulations were conducted in order to investigate the effects of different numerical approaches showing indications that the method of installation and particle rotation could influence greatly in the conditions around the numerical pile. Minor effects were also noted due to change in penetration velocity and pile-soil friction. The difference in behavior of a moving and a stationary pile shows good qualitative agreement with previous experimental results indicating the necessity of realizing a force equilibrium process prior to any load-test to be simulated.

[Gastrointestinal bleeding and delirium, challenges in the diagnosis of gallstone ileus: A case report and review of literature].

PubMed

Aguilar-Espinosa, Francisco; Gálvez-Romero, José Luis; Falfán-Moreno, Jesús; Guerrero-Martínez, Gustavo Adolfo; Vargas-Solís, Facundo

2017-12-01

Gallstone ileus is a non-strangulated mechanical obstruction of the small bowel or colon as a result of the passage of gallstones through a biliary enteric fistula. It is a rare complication of cholelithiasis, affects patients over 65 years, and the disease occurs predominantly in females. Preoperative diagnosis is difficult due to the lack of specific signs and symptoms in elderly patients with multiple comorbidities. A 93-year-old female presenting with a one-week history of upper gastrointestinal bleeding, electrolyte imbalance and community- acquired pneumonia pneumonia. During her prolonged hospital stay she presented an intestinal obstruction. The diagnosis of gallstone ileus was made by CT scan. Despite surgical treatment, she died due to late diagnosis. Gallstone ileus is a rare pathology, difficulty in diagnosis prolongs hospital stay, which directly influences mortality. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Terminal-Area Aircraft Intent Inference Approach Based on Online Trajectory Clustering.

PubMed

Yang, Yang; Zhang, Jun; Cai, Kai-quan

2015-01-01

Terminal-area aircraft intent inference (T-AII) is a prerequisite to detect and avoid potential aircraft conflict in the terminal airspace. T-AII challenges the state-of-the-art AII approaches due to the uncertainties of air traffic situation, in particular due to the undefined flight routes and frequent maneuvers. In this paper, a novel T-AII approach is introduced to address the limitations by solving the problem with two steps that are intent modeling and intent inference. In the modeling step, an online trajectory clustering procedure is designed for recognizing the real-time available routes in replacing of the missed plan routes. In the inference step, we then present a probabilistic T-AII approach based on the multiple flight attributes to improve the inference performance in maneuvering scenarios. The proposed approach is validated with real radar trajectory and flight attributes data of 34 days collected from Chengdu terminal area in China. Preliminary results show the efficacy of the presented approach.

Atypical Distant Metastasis of Breast Malignant Phyllodes Tumors: A Case Report and Literature Review.

PubMed

de Foucher, Tiphaine; Roussel, Hélène; Hivelin, Mikael; Rossi, Léa; Cornou, Caroline; Bats, Anne-Sophie; Deloménie, Myriam; Lécuru, Fabrice; Ngô, Charlotte

2017-01-01

Malignant phyllodes tumors (MPT) are rare breast neoplasms. Preoperative diagnosis is often challenging due to the unspecific clinical, radiological, and histological characteristics of the tumor. Dissemination pathways are local with chest wall invasion, regional with lymph nodes metastasis, and distant, hematogenous, mostly to the lungs, bones, and brain. Distant metastasis (DM) can be synchronous or appear months to years after the diagnosis and initial management. The current report describes the case of a 57-year-old woman presenting with a giant/neglected MPT of the breast, with no DM at initial staging, treated by radical modified mastectomy. Motor disorders due to medullar compression by a paravertebral mass appeared at short follow-up, also treated surgically. The patient died from several DM of rapid evolution. To our knowledge, this is the only case described of MPT with metastases to soft tissue causing medullar compression. We present a literature review on unusual metastatic localizations of MPT.

Complexities of management of a urostomy in Ehlers-Danlos syndrome: a reflective account.

PubMed

Oxenham, Julie

Mary (pseudonym) is a 30-year-old woman who underwent a urinary diversion and formation of an ileal conduit/urostomy (urinary stoma) due to the formation of multiple bladder diverticula, which caused micturition difficulties and recurrent urinary tract infections with associated pain and discomfort. The bladder diverticula were caused by Ehlers-Danlos syndrome (EDS), a hereditary disorder of the connective tissue or, particulary, defective collagen. Surgical intervention in patients with EDS is prone to complications due to poor wound healing, including issues of dehiscence, postoperative bleeding and poor uptake of anaesthesia and analgesia. After an initial presentation of the syndrome of EDS and Mary's history, this article offers a reflective account (informed by Gibbs' Reflective Cycle) and illustrates the complexities of caring for an individual with EDS who undergoes stoma formation. The author, a stoma care nurse, demonstrates how using purposeful reflection resulted in better understanding and awareness of caring for an individual with a rare syndrome and the nursing challenges this presented.

Elastic Model Transitions Using Quadratic Inequality Constrained Least Squares

NASA Technical Reports Server (NTRS)

Orr, Jeb S.

2012-01-01

A technique is presented for initializing multiple discrete finite element model (FEM) mode sets for certain types of flight dynamics formulations that rely on superposition of orthogonal modes for modeling the elastic response. Such approaches are commonly used for modeling launch vehicle dynamics, and challenges arise due to the rapidly time-varying nature of the rigid-body and elastic characteristics. By way of an energy argument, a quadratic inequality constrained least squares (LSQI) algorithm is employed to e ect a smooth transition from one set of FEM eigenvectors to another with no requirement that the models be of similar dimension or that the eigenvectors be correlated in any particular way. The physically unrealistic and controversial method of eigenvector interpolation is completely avoided, and the discrete solution approximates that of the continuously varying system. The real-time computational burden is shown to be negligible due to convenient features of the solution method. Simulation results are presented, and applications to staging and other discontinuous mass changes are discussed

Hypersensitivity pneumonitis due to flavocoxid: are corticosteroids necessary?

PubMed

Panduranga, Veena; Atienza, Jonessa; Kumar, Anupam; Metersky, Mark L

2013-02-01

Hypersensitivity pneumonitis (HP) is a rare adverse event with flavocoxid (Limbrel) use. Patients present with nonspecific symptoms after exposure to an inciting agent. A 42-year-old female presented with worsening dyspnea on exertion and pleuritic midsternal chest pain. Her symptoms failed to abate with outpatient azithromycin for a diagnosis of community-acquired pneumonia. She was seen again at the emergency department (ED) due to symptom progression and exertional hypoxia. Chest reoentgenogram (x-ray) and computed tomography (CT) chest revealed bilateral infiltrates. Her history was significant for initiation of flavocoxid (Limbrel) two weeks prior, and a diagnosis of hypersensitivity pneumonitis was made. Once flavocoxid was discontinued, symptoms and radiologic studies improved without requiring biopsy or steroids. Hypersensitivity pneumonitis is associated with many pharmacological agents and is challenging to diagnose, given nonspecific symptoms and radiologic findings. In the absence of specific indications to use corticosteroids, symptoms of HP might resolve with cessation of the offending agent, as proven by this case.

Congenital Lobar Emphysema: An Approach of Anesthetic Management.

PubMed

Mourya, Meenakshi; Meena, Dharam Singh

2016-08-01

Congenital Lobar Emphysema (CLE) is a medical condition which is quiet rarely seen especially in neonates. The disease is characterized by over inflation of lungs which is produced due to inhibition of escape of inspired air from lungs. This condition usually occurs in infants due to partial obstruction of the bronchus and can be reversed with timely and planned anaesthetic management. Here in, we are presenting a case of an infant who was merely four months of age. CLE was affecting his left upper lobe since birth which was being treated as lobar pneumonia outside at some peripheral health center. The case presented to hospital with the symptoms acute respiratory distress and was taken up for urgent surgical management. Left upper lobectomy was performed which relived his symptoms. Case was discharged from hospital after 10 days of uneventful hospital stay. The case was challenging, as it involved careful and planned anaesthetic management of lung separation as well as prevention of hyperventilation of the un-involved lung.

Solvothermal method as a green chemistry solution for micro-encapsulation of phase change materials for high temperature thermal energy storage

NASA Astrophysics Data System (ADS)

Tudor, Albert Ioan; Motoc, Adrian Mihail; Ciobota, Cristina Florentina; Ciobota, Dan. Nastase; Piticescu, Radu Robert; Romero-Sanchez, Maria Dolores

2018-05-01

Thermal energy storage systems using phase change materials (PCMs) as latent heat storage are one of the main challenges at European level in improving the performances and efficiency of concentrated solar power energy generation due to their high energy density. PCM with high working temperatures in the temperature range 300-500 °C are required for these purposes. However their use is still limited due to the problems raised by the corrosion of the majority of high temperature PCMs and lower thermal transfer properties. Micro-encapsulation was proposed as one method to overcome these problems. Different micro-encapsulation methods proposed in the literature are presented and discussed. An original process for the micro-encapsulation of potassium nitrate as PCM in inorganic zinc oxide shells based on a solvothermal method followed by spray drying to produce microcapsules with controlled phase composition and distribution is proposed and their transformation temperatures and enthalpies measured by differential scanning calorimetry are presented.

DNA Nanotechnology-Enabled Interfacial Engineering for Biosensor Development.

PubMed

Ye, Dekai; Zuo, Xiaolei; Fan, Chunhai

2018-06-12

Biosensors represent biomimetic analytical tools for addressing increasing needs in medical diagnosis, environmental monitoring, security, and biodefense. Nevertheless, widespread real-world applications of biosensors remain challenging due to limitations of performance, including sensitivity, specificity, speed, and reproducibility. In this review, we present a DNA nanotechnology-enabled interfacial engineering approach for improving the performance of biosensors. We first introduce the main challenges of the biosensing interfaces, especially under the context of controlling the DNA interfacial assembly. We then summarize recent progress in DNA nanotechnology and efforts to harness DNA nanostructures to engineer various biological interfaces, with a particular focus on the use of framework nucleic acids. We also discuss the implementation of biosensors to detect physiologically relevant nucleic acids, proteins, small molecules, ions, and other biomarkers. This review highlights promising applications of DNA nanotechnology in interfacial engineering for biosensors and related areas.

Introduction to State Estimation of High-Rate System Dynamics

PubMed Central

Dodson, Jacob; Joyce, Bryan

2018-01-01

Engineering systems experiencing high-rate dynamic events, including airbags, debris detection, and active blast protection systems, could benefit from real-time observability for enhanced performance. However, the task of high-rate state estimation is challenging, in particular for real-time applications where the rate of the observer’s convergence needs to be in the microsecond range. This paper identifies the challenges of state estimation of high-rate systems and discusses the fundamental characteristics of high-rate systems. A survey of applications and methods for estimators that have the potential to produce accurate estimations for a complex system experiencing highly dynamic events is presented. It is argued that adaptive observers are important to this research. In particular, adaptive data-driven observers are advantageous due to their adaptability and lack of dependence on the system model. PMID:29342855

Providing health services for children with special health care needs on out-of-state field trips.

PubMed

Erwin, Karen; Clark, Saudi; Mercer, Sharon Eli

2014-03-01

An increasing number of children attend school with special health care needs. Title II of the Americans with Disabilities Act (ADA) requires all school-sponsored activities to be easily accessible to all students. School-sponsored field trips enhance students' education, and students who require health services may not be excluded. For students with special health care needs, fully participating in the field trip experience presents unique challenges. These challenges are further complicated by out-of-state field trips due to variances in nurse practice acts, variances in delegation regulations, and most recently, state-by-state participation or nonparticipation in the Nurse Licensure Compact. Review of state laws, regulations, and nursing scope of practice for school health services is critical when planning and problem solving for students requiring health services on out-of-state field trips.

Orthodontic treatment for a patient with multiple sclerosis

PubMed Central

Bakathir, Manal A

2017-01-01

Multiple sclerosis (MS) is a chronic, autoimmune inflammatory disorder of the central nervous system (CNS) that affects myelinated axons, destroying the myelin and damaging axons to varying degrees. The course of MS is highly varied and unpredictable. Metals used during orthodontic treatment can negatively affect imaging techniques used to diagnose and monitor the progression of MS, while medications used to treat MS can negatively affect orthodontic tooth movement. The present case report highlights some of the challenges encountered during orthodontic treatment of a patient with MS and how to overcome them. The patient was a 20-year-old woman with complaints of diastema and spacing in the upper arch. Although closing the spaces was challenging due to some of the MS medications, she was treated successfully, without complications, within 20 months using closing loops. PMID:28717636

Establishing a head and neck unit in a developing country.

PubMed

Aswani, J; Baidoo, K; Otiti, J

2012-06-01

Head and neck cancers pose an especially serious problem in developing countries due to late presentation requiring complex surgical intervention. These countries are faced with many challenges, ranging from insufficient health care staff to problems with peri-operative requirements, diagnostic facilities, chemoradiation services and research funding.These challenges can be addressed through the training of head and neck surgeons and support personnel, the improvement of cancer awareness in local communities, and the establishment of dedicated head and neck institutes which focus on the special needs of head and neck cancer patients.All these changes can best be achieved through collaborative efforts with external partners. The Karl Storz Fellowship in Advanced Head and Neck Cancer, enabling training at the University of Cape Town, South Africa, has served as a springboard towards establishing head and neck services in developing sub-Saharan African countries.

Repeated General Anesthesia in a Patient With Noonan Syndrome.

PubMed

Asahi, Yoshinao; Fujii, Ryosuke; Usui, Naoko; Kagamiuchi, Hajime; Omichi, Shiro; Kotani, Junichiro

2015-01-01

Noonan syndrome (NS) is an autosomal dominant disorder characterized by facial anomalies, short stature, chest deformity, congenital heart diseases, and other comorbidities. The challenges faced during anesthetic management of patients with NS could be due to congenital heart diseases, hemostatic disorders, and airway anomalies. Here we describe dental treatment under general anesthesia performed for a 28-year-old man with NS. He had characteristic features of NS along with mild pulmonary valve stenosis. Dental treatment under general anesthesia was performed successfully on 13 occasions with nasotracheal intubation under curve-tipped suction catheter guidance or insertion of a reinforced laryngeal mask airway. This case suggests that for patients with NS, who might present several challenges, dental anesthesiologists should consider the extent of the patient's disorders to enable them to perform dental treatment safely under general anesthesia.

Whole-genome alignment.

PubMed

Dewey, Colin N

2012-01-01

Whole-genome alignment (WGA) is the prediction of evolutionary relationships at the nucleotide level between two or more genomes. It combines aspects of both colinear sequence alignment and gene orthology prediction, and is typically more challenging to address than either of these tasks due to the size and complexity of whole genomes. Despite the difficulty of this problem, numerous methods have been developed for its solution because WGAs are valuable for genome-wide analyses, such as phylogenetic inference, genome annotation, and function prediction. In this chapter, we discuss the meaning and significance of WGA and present an overview of the methods that address it. We also examine the problem of evaluating whole-genome aligners and offer a set of methodological challenges that need to be tackled in order to make the most effective use of our rapidly growing databases of whole genomes.

Repeated General Anesthesia in a Patient With Noonan Syndrome

PubMed Central

Asahi, Yoshinao; Fujii, Ryosuke; Usui, Naoko; Kagamiuchi, Hajime; Omichi, Shiro; Kotani, Junichiro

2015-01-01

Noonan syndrome (NS) is an autosomal dominant disorder characterized by facial anomalies, short stature, chest deformity, congenital heart diseases, and other comorbidities. The challenges faced during anesthetic management of patients with NS could be due to congenital heart diseases, hemostatic disorders, and airway anomalies. Here we describe dental treatment under general anesthesia performed for a 28-year-old man with NS. He had characteristic features of NS along with mild pulmonary valve stenosis. Dental treatment under general anesthesia was performed successfully on 13 occasions with nasotracheal intubation under curve-tipped suction catheter guidance or insertion of a reinforced laryngeal mask airway. This case suggests that for patients with NS, who might present several challenges, dental anesthesiologists should consider the extent of the patient's disorders to enable them to perform dental treatment safely under general anesthesia. PMID:26061577

The Health Consequences of Obesity in Young Adulthood.

PubMed

Cheng, Hoi Lun; Medlow, Sharon; Steinbeck, Katharine

2016-03-01

Young adults are gaining weight faster than any age group. This weight gain and the appearance of obesity-related comorbidities often commence in adolescence. Psychosocial distress and mental health issues are common and debilitating, and treatment approaches are likely to be similar to those for adolescents. At the same time, young adults may have physical morbidities which will continue and worsen throughout adulthood, such as hypertension, diabetes and polycystic ovarian syndrome. Health consequences of obesity are challenging to manage in young adults as their symptoms may be minimal, they are less likely to engage with healthcare due to other life priorities and their neurocognitive developmental stage makes therapy adherence difficult. Clinicians who manage young adults with obesity need to be aware of these age-specific challenges, as well as the sexual and reproductive health concerns that are present in this age group.

Stent-Assisted Coil Embolization of a Symptomatic Renal Artery Aneurysm at a Bifurcation Point.

PubMed

Nassiri, Naiem; Huntress, Lauren A

2017-07-01

Symptomatic renal artery aneurysms at bifurcation points present challenging clinical scenarios rarely amenable to endovascular repair due to concerns regarding parenchymal loss following intervention. Herein, we add to the scant body of literature describing successful endovascular repair of a saccular, symptomatic renal artery aneurysm situated at a bifurcation point. A 52-year-old woman with a 2.5-cm extraparenchymal, saccular, symptomatic left renal artery aneurysm underwent self-expanding stent-assisted detachable platinum microcoil embolization. Complete aneurysm exclusion was achieved with minimal parenchymal loss. There were no perioperative complications, and no evidence of acute kidney injury perioperatively or at 3-month follow-up. Sustained symptomatic relief was achieved. Endovascular therapy can provide safe and effective aneurysm treatment within challenging bifurcated renal artery anatomy. Copyright © 2017 Elsevier Inc. All rights reserved.

Presidential Green Chemistry Challenge: 2002 Designing Greener Chemicals Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 2002 award winner, Chemical Specialties, developed an alkaline copper quaternary wood preservative to replace chromated copper arsenate preservative phased out due to risk to children.

Novel therapeutic approaches in chondrosarcoma.

PubMed

Polychronidou, Genovefa; Karavasilis, Vasilios; Pollack, Seth M; Huang, Paul H; Lee, Alex; Jones, Robin L

2017-03-01

Chondrosarcoma is a malignant tumor of bones, characterized by the production of cartilage matrix. Due to lack of effective treatment for advanced disease, the clinical management of chondrosarcomas is exceptionally challenging. Current research focuses on elucidating the molecular events underlying the pathogenesis of this rare bone malignancy, with the goal of developing new molecularly targeted therapies. Signaling pathways suggested to have a role in chondrosarcoma include Hedgehog, Src, PI3k-Akt-mTOR and angiogenesis. Mutations in IDH1/2, present in more than 50% of primary conventional chondrosarcomas, make the development of IDH inhibitors a promising treatment option. The present review discusses the preclinical and early clinical data on novel targeted therapeutic approaches in chondrosarcoma.

Valley splitting of single-electron Si MOS quantum dots

DOE PAGES

Gamble, John King; Harvey-Collard, Patrick; Jacobson, N. Tobias; ...

2016-12-19

Here, silicon-based metal-oxide-semiconductor quantum dots are prominent candidates for high-fidelity, manufacturable qubits. Due to silicon's band structure, additional low-energy states persist in these devices, presenting both challenges and opportunities. Although the physics governing these valley states has been the subject of intense study, quantitative agreement between experiment and theory remains elusive. Here, we present data from an experiment probing the valley states of quantum dot devices and develop a theory that is in quantitative agreement with both this and a recently reported experiment. Through sampling millions of realistic cases of interface roughness, our method provides evidence that the valley physicsmore » between the two samples is essentially the same.« less

Particle Filters for Real-Time Fault Detection in Planetary Rovers

NASA Technical Reports Server (NTRS)

Dearden, Richard; Clancy, Dan; Koga, Dennis (Technical Monitor)

2001-01-01

Planetary rovers provide a considerable challenge for robotic systems in that they must operate for long periods autonomously, or with relatively little intervention. To achieve this, they need to have on-board fault detection and diagnosis capabilities in order to determine the actual state of the vehicle, and decide what actions are safe to perform. Traditional model-based diagnosis techniques are not suitable for rovers due to the tight coupling between the vehicle's performance and its environment. Hybrid diagnosis using particle filters is presented as an alternative, and its strengths and weakeners are examined. We also present some extensions to particle filters that are designed to make them more suitable for use in diagnosis problems.

Occupational allergy to Spagulax®(Plantago ovata seed).

PubMed

Viñas, M; Pineda, F; Izquierdo-Domínguez, A; Castillo, M; Castillo, M J; Hernández, N; Ibero, M

2017-11-01

We report the case of a 36-year-old male pharmaceutical laboratory worker. On handling Spagulax ® sachets whose content is a laxative called Plantago ovata, he immediately presented rhinoconjunctivitis. Methods. Specific allergy study included SDS-PAGE with Western Blot and specific nasal challenge to Plantago ovata extract. Results. Prick by prick for Spagulax ® was negative. Total IgE: 126.5 U/mL. Western Blot recognized two proteins of 15 and 20 kDa in the extract of Plantago ovata and three proteins of 15, 18 and 50 kDa in the extract of Plantago lanceolata. Conclusions. We present a case of occupational allergy due to inhalation of and/or contact with Plantago ovata seeds.

High-Temperature Piezoelectric Sensing

PubMed Central

Jiang, Xiaoning; Kim, Kyungrim; Zhang, Shujun; Johnson, Joseph; Salazar, Giovanni

2014-01-01

Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented. PMID:24361928

Emittance measurements in low energy ion storage rings

NASA Astrophysics Data System (ADS)

Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

2018-07-01

The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

Thyroid storm causing placental abruption: Cardiovascular and management complications for the Intensivist.

PubMed

Lane, Andrew S; Tarvade, Sanjay

2015-08-01

Thyroid storm is a rare and serious complication of pregnancy which can lead to spontaneous abortion, preterm delivery, preeclampsia and cardiac failure. It is also associated with high maternal and foetal mortality if not diagnosed and managed promptly. The diagnosis of thyroid storm in pregnancy can pose significant challenges due to its presentation being similar to other pregnancy-related complications. We present a patient who developed thyroid storm at 29 weeks of pregnancy, which resulted in pre-term delivery, cardiac failure and thyroidectomy. We discuss the treatment of thyroid storm in pregnancy, the decision making involved in proceeding to thyroidectomy or to use radio-iodine, and foetal thyroid status in thyrotoxicosis.

Dark Energy: A Crisis for Fundamental Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stubbs, Christopher

2010-04-12

Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talkmore » will present experiments and observations that are exploring this issue.« less

Stress-strain response of plastic waste mixed soil.

PubMed

Babu, G L Sivakumar; Chouksey, Sandeep Kumar

2011-03-01

Recycling plastic waste from water bottles has become one of the major challenges worldwide. The present study provides an approach for the use plastic waste as reinforcement material in soil. The experimental results in the form of stress-strain-pore water pressure response are presented. Based on experimental test results, it is observed that the strength of soil is improved and compressibility reduced significantly with addition of a small percentage of plastic waste to the soil. The use of the improvement in strength and compressibility response due to inclusion of plastic waste can be advantageously used in bearing capacity improvement and settlement reduction in the design of shallow foundations. Copyright © 2010 Elsevier Ltd. All rights reserved.

Research progress on trifluoromethyl-based radical reaction process

NASA Astrophysics Data System (ADS)

Song, Hao

2017-12-01

Due to the unique properties imparted by the trifluoromethyl group, such as high electron density and strong lipotropy, which effectively improve acidity, lipophilicity and metabolic stability of the molecule itself, trifluoromethyl-substituted organic compounds are becoming increasingly important as structural motifs in pharmaceuticals, agrochemicals and organic materials. In this review, we present several methods developed for the direct introduction of a trifluoromethyl group, beginning with its rich and storied history. Then the present article addresses mechanism and process in carbon-carbon bond forming reaction based on radical process which is divided into three parts according to the way of CF3 radical generation. Finally, challenges and opportunities of researches on trifluoromethylation reactions facing are prospected.

77 FR 11115 - Mobility Fund Phase I Auction Limited Extension of Deadlines for Comments and Reply Comments on...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

... Limited Extension of Deadlines for Comments and Reply Comments on Census Block Eligibility Challenges... reply comments on census block eligibility challenges in AU Docket No. 12-25. The comment and reply... Block Eligibility Challenges (deadline extended): March 16, 2012. Reply Comments due on Census Block...

Moral Injury, Soul Repair, and Creating a Place for Grace

ERIC Educational Resources Information Center

Antal, Chris J.; Winings, Kathy

2015-01-01

Our returning veterans face many challenges from loss of limb and physical disabilities to posttraumatic stress disorder, depression, substance abuse, homelessness, family problems, and unemployment. The greater challenge, though, for returning veterans is the injury to their soul due to the war and violence they have experienced. Our challenge is…

Landing Distance Minimization to Prevent Overrun Accidents Using Field Theory and Stabilizing Air Traffic - A Novel Approach

NASA Astrophysics Data System (ADS)

Krishna Kumar, R.; Navaneeth, M.; Shachin Shibi, R.

2017-09-01

Airplane is considered to be the pinnacle of engineering as it has proven that it is possible for a manmade object to fly. Before its invention, flying was just a dream for mankind. In such an esteemed domain, landing is the most challenging part and it is where a large number of accidents occur, especially due to overrun. As the name suggests, overrun accidents occur due to insufficient runway length. In the present study, the concept of planar electromagnetic fields is incorporated to minimize the landing distance of an aircraft, thus preventing the overrun accidents. As a result, unexpected losses can be avoided. In addition to this, the stability of air traffic control can be perpetuated and the fuel consumed during loitering time can be diminished.

Study of hole characteristics in Laser Trepan Drilling of ZTA

NASA Astrophysics Data System (ADS)

Saini, Surendra K.; Dubey, Avanish K.; Upadhyay, B. N.; Choubey, A.

2018-07-01

Zirconia Toughened Alumina ceramic is widely used for aerospace components, combustion chambers, heat exchangers, bearings and pumps mainly due to its improved mechanical and thermal properties. To make holes in thick section Zirconia Toughened Alumina ceramics is a major challenge due to its unfavorable machining characteristics. Recent researches have explored that laser machining can overcome the machining limitations of advanced materials having improved mechanical properties. In present research, authors have analyzed the effect of Laser Trepan Drilling on hole characteristics of 6.0 mm thick Zirconia Toughened Alumina. Effect of significant process parameters on hole characteristics such as hole circularity at top and bottom, hole taper, and spatter size have been studied. The optimum ranges of these parameters have been suggested on the basis of empirical modeling and optimization.

Boron Nitride Coated Carbon Nanotube Arrays with Enhanced Compressive Mechanical Property

NASA Astrophysics Data System (ADS)

Jing, Lin; Tay, Roland Yingjie; Li, Hongling; Tsang, Siu Hon; Tan, Dunlin; Zhang, Bowei; Tok, Alfred Iing Yoong; Teo, Edwin Hang Tong

Vertically aligned carbon nanotube (CNT) array is one of the most promising energy dissipating materials due to its excellent temperature invariant mechanical property. However, the CNT arrays with desirable recoverability after compression is still a challenge. Here, we report on the mechanical enhancement of the CNT arrays reinforced by coating with boron nitride (BN) layers. These BN coated CNT (BN/CNT) arrays exhibit excellent compressive strength and recoverability as compared to those of the as-prepared CNT arrays which totally collapsed after compression. In addition, the BN coating also provides better resistance to oxidation due to its intrinsic thermal stability. This work presented here opens a new pathway towards tuning mechanical behavior of any arbitrary CNT arrays for promising potential such as damper, vibration isolator and shock absorber applications.

Future challenges in the elimination of bacterial meningitis.

PubMed

Bottomley, Matthew J; Serruto, Davide; Sáfadi, Marco Aurélio Palazzi; Klugman, Keith P

2012-05-30

Despite the widespread implementation of several effective vaccines over the past few decades, bacterial meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Group B Streptococcus (GBS) still results in unacceptably high levels of human mortality and morbidity. A residual disease burden due to bacterial meningitis is also apparent due to a number of persistent or emerging pathogens, including Mycobacterium tuberculosis, Escherichia coli, Staphylococcus aureus, Salmonella spp. and Streptococcus suis. Here, we review the current status of bacterial meningitis caused by these pathogens, highlighting how past and present vaccination programs have attempted to counter these pathogens. We discuss how improved pathogen surveillance, implementation of current vaccines, and development of novel vaccines may be expected to further reduce bacterial meningitis and related diseases in the future. Copyright © 2011 Elsevier Ltd. All rights reserved.

EvoGraph: On-The-Fly Efficient Mining of Evolving Graphs on GPU

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sengupta, Dipanjan; Song, Shuaiwen

With the prevalence of the World Wide Web and social networks, there has been a growing interest in high performance analytics for constantly-evolving dynamic graphs. Modern GPUs provide massive AQ1 amount of parallelism for efficient graph processing, but the challenges remain due to their lack of support for the near real-time streaming nature of dynamic graphs. Specifically, due to the current high volume and velocity of graph data combined with the complexity of user queries, traditional processing methods by first storing the updates and then repeatedly running static graph analytics on a sequence of versions or snapshots are deemed undesirablemore » and computational infeasible on GPU. We present EvoGraph, a highly efficient and scalable GPU- based dynamic graph analytics framework.« less

New concept in natural history and management of diabetes mellitus in thalassemia major.

PubMed

Chatterjee, Ratna; Bajoria, Rekha

2009-01-01

Diabetes Mellitus is a major endocrinopathy, which occurs due transfusional haemosiderosis and is found in 20-30% of adult patients with beta-thalassaemia worldwide, accounting for significant morbidity. It is multifactorial with iron loading being the dominant cause and its management poses a clinical challenge. Diabetes in thalassaemia patients is distinct from type 2 diabetes. It is peculiar in many aspects including its pathophysiology and occurs due to insulin resistance as well as islet cell insufficiency. This article reviews the natural history of diabetes in this presentation with emphasis on prevention monitoring and management. Use of MRI techniques may be useful for future monitoring as well as biochemical monitoring to prevent complications of diabetes. Early intervention with intensified chelation may reverse pancreatic function and structural changes as evident from MRI.

Brazilian agriculture and environmental legislation: status and future challenges.

PubMed

Sparovek, Gerd; Berndes, Göran; Klug, Israel L F; Barretto, Alberto G O P

2010-08-15

Brazilian agriculture covers about one-third of the land area and is expected to expand further. We assessed the compliance of present Brazilian agriculture with environmental legislation and identified challenges for agricultural development connected to this legislation. We found (i) minor illegal land use in protected areas under public administration, (ii) a large deficit in legal reserves and protected riparian zones on private farmland, and (iii) large areas of unprotected natural vegetation in regions experiencing agriculture expansion. Achieving full compliance with the environmental laws as they presently stand would require drastic changes in agricultural land use, where large agricultural areas are taken out of production and converted back to natural vegetation. The outcome of a full compliance with environmental legislation might not be satisfactory due to leakage, where pristine unprotected areas become converted to compensate for lost production as current agricultural areas are reconverted to protected natural vegetation. Realizing the desired protection of biodiversity and natural vegetation, while expanding agriculture to meet food and biofuel demand, may require a new approach to environmental protection. New legal and regulatory instruments and the establishment of alternative development models should be considered.

Advancements in the oral delivery of Docetaxel: challenges, current state-of-the-art and future trends

PubMed Central

Sohail, Muhammad Farhan; Rehman, Mubashar; Sarwar, Hafiz Shoaib; Naveed, Sara; Salman, Omer; Bukhari, Nadeem Irfan; Hussain, Irshad; Webster, Thomas J; Shahnaz, Gul

2018-01-01

The oral delivery of cancer chemotherapeutic drugs is challenging due to low bioavailability, gastrointestinal side effects, first-pass metabolism and P-glycoprotein efflux pumps. Thus, chemotherapeutic drugs, including Docetaxel, are administered via an intravenous route, which poses many disadvantages of its own. Recent advances in pharmaceutical research have focused on designing new and efficient drug delivery systems for site-specific targeting, thus leading to improved bioavailability and pharmacokinetics. A decent number of studies have been reported for the safe and effective oral delivery of Docetaxel. These nanocarriers, including liposomes, polymeric nanoparticles, metallic nanoparticles, hybrid nanoparticles, dendrimers and so on, have shown promising results in research papers and clinical trials. The present article comprehensively reviews the research efforts made so far in designing various advancements in the oral delivery of Docetaxel. Different strategies to improve oral bioavailability, prevent first-pass metabolism and inhibition of efflux pumping leading to improved pharmacokinetics and anticancer activity are discussed. The final portion of this review article presents key issues such as safety of nanomaterials, regulatory approval and future trends in nanomedicine research. PMID:29922053

Advancements in the oral delivery of Docetaxel: challenges, current state-of-the-art and future trends.

PubMed

Sohail, Muhammad Farhan; Rehman, Mubashar; Sarwar, Hafiz Shoaib; Naveed, Sara; Salman, Omer; Bukhari, Nadeem Irfan; Hussain, Irshad; Webster, Thomas J; Shahnaz, Gul

2018-01-01

The oral delivery of cancer chemotherapeutic drugs is challenging due to low bioavailability, gastrointestinal side effects, first-pass metabolism and P-glycoprotein efflux pumps. Thus, chemotherapeutic drugs, including Docetaxel, are administered via an intravenous route, which poses many disadvantages of its own. Recent advances in pharmaceutical research have focused on designing new and efficient drug delivery systems for site-specific targeting, thus leading to improved bioavailability and pharmacokinetics. A decent number of studies have been reported for the safe and effective oral delivery of Docetaxel. These nanocarriers, including liposomes, polymeric nanoparticles, metallic nanoparticles, hybrid nanoparticles, dendrimers and so on, have shown promising results in research papers and clinical trials. The present article comprehensively reviews the research efforts made so far in designing various advancements in the oral delivery of Docetaxel. Different strategies to improve oral bioavailability, prevent first-pass metabolism and inhibition of efflux pumping leading to improved pharmacokinetics and anticancer activity are discussed. The final portion of this review article presents key issues such as safety of nanomaterials, regulatory approval and future trends in nanomedicine research.

Innovative Robot Archetypes for In-Space Construction and Maintenance

NASA Technical Reports Server (NTRS)

Rehnmark, Fredrik; Ambrose, Robert O.; Kennedy, Brett; Diftler, Myron; Mehling Joshua; Brigwater, Lyndon; Radford, Nicolaus; Goza, S. Michael; Culbert, Christopher

2005-01-01

The space environment presents unique challenges and opportunities in the assembly, inspection and maintenance of orbital and transit spaceflight systems. While conventional Extra-Vehicular Activity (EVA) technology, out of necessity, addresses each of the challenges, relatively few of the opportunities have been exploited due to crew safety and reliability considerations. Extra-Vehicular Robotics (EVR) is one of the least-explored design spaces but offers many exciting innovations transcending the crane-like Space Shuttle and International Space Station Remote Manipulator System (RMS) robots used for berthing, coarse positioning and stabilization. Microgravity environments can support new robotic archetypes with locomotion and manipulation capabilities analogous to undersea creatures. Such diversification could enable the next generation of space science platforms and vehicles that are too large and fragile to launch and deploy as self-contained payloads. Sinuous manipulators for minimally invasive inspection and repair in confined spaces, soft-stepping climbers with expansive leg reach envelopes and free-flying nanosatellite cameras can access EVA worksites generally not accessible to humans in spacesuits. These and other novel robotic archetypes are presented along with functionality concepts

Modeling Pilot State in Next Generation Aircraft Alert Systems

NASA Technical Reports Server (NTRS)

Carlin, Alan S.; Alexander, Amy L.; Schurr, Nathan

2011-01-01

The Next Generation Air Transportation System will introduce new, advanced sensor technologies into the cockpit that must convey a large number of potentially complex alerts. Our work focuses on the challenges associated with prioritizing aircraft sensor alerts in a quick and efficient manner, essentially determining when and how to alert the pilot This "alert decision" becomes very difficult in NextGen due to the following challenges: 1) the increasing number of potential hazards, 2) the uncertainty associated with the state of potential hazards as well as pilot slate , and 3) the limited time to make safely-critical decisions. In this paper, we focus on pilot state and present a model for anticipating duration and quality of pilot behavior, for use in a larger system which issues aircraft alerts. We estimate pilot workload, which we model as being dependent on factors including mental effort, task demands. and task performance. We perform a mathematically rigorous analysis of the model and resulting alerting plans. We simulate the model in software and present simulated results with respect to manipulation of the pilot measures.

Literature review relevant to particle erosion in complex geometries

NASA Astrophysics Data System (ADS)

Volent, Eirik; Dahlhaug, Ole Gunnar

2018-06-01

Erosion is a challenge in many industries where fluid is transferred through pipe and valve arrangements. Wear can occur in a variety of systems and is often related to the presents of droplets or solid particles in the fluid stream. Solid particles are in many cases present in hydropower systems, and can cause severe damage to system components. Flow conditions, particle size and concentration vary greatly and can thus cause a vast variety of damage, ranging from manageable wear to component failure. The following paper will present a summary of literature relevant to the prediction of erosion in complex geometries. The intention of the review is to investigate the current state of the art, directly relevant to the prediction of wear due to solid particle erosion in complex geometries.

Central nervous system lymphoma presenting as trigeminal neuralgia: A diagnostic challenge.

PubMed

Ang, Jensen W J; Khanna, Arjun; Walcott, Brian P; Kahle, Kristopher T; Eskandar, Emad N

2015-07-01

We describe an atypical man with diffuse large B cell lymphoma localized to the sphenoid wing and adjacent cavernous sinus, initially presenting with isolated ipsilateral facial pain mimicking trigeminal neuralgia due to invasion of Meckel's cave but subsequently progressing to intra-axial extension and having synchronous features of systemic lymphoma. Primary central nervous system lymphoma is uncommon, accounting for approximately 2% of all primary intracranial tumors, but its incidence has been steadily increasing in some groups [1]. It usually arises in the periventricular cerebral white matter, and reports of lymphoma in extra-axial regions are rare [2]. This man highlights the importance of maintaining lymphoma in the differential diagnosis of tumors of the skull base presenting with trigeminal neuralgia-like symptoms. Copyright © 2015 Elsevier Ltd. All rights reserved.

'She's my sister-in-law, my visitor, my friend' -- challenges of staff identity in home follow-up in an HIV trial in Western Kenya.

PubMed

Madiega, Philister Adhiambo; Jones, Gemma; Prince, Ruth Jane; Geissler, Paul Wenzel

2013-04-01

Identities ascribed to research staff in face-to-face encounters with participants have been raised as key ethical challenge in transnational health research. 'Misattributed' identities that do not just deviate from researchers' self-image, but obscure unequivocal aspects of researcher identity - e.g. that they are researchers - are a case of such ethical problem. Yet, the reasonable expectation of unconcealed identity can conflict with another ethical premise: confidentiality; this poses challenges to staff visiting participants at home. We explore these around a case study of 'follow-up' staff, observed during an ethnographic study of a Kenyan HIV 'trial community', which included participant observation, conversations, and interviews with staff (n = 79) and participants (n = 89). We found that because of the need to maintain confidentiality and because of some suspicions towards researchers, research staff drew upon alternative identities - presenting themselves to non-participants as relatives or friends, rather than as researchers. Several staff experienced this as necessary but uncomfortable. Simultaneously, staff and participants forged close relations in line with their fictional identities, which however also posed challenges because they entailed personal responsibilities that were difficult to live up to, due to limited resources, and the trial's limited duration. Similar challenges may arise in transnational HIV treatment programmes and should be explored further in that context. © 2013 Blackwell Publishing Ltd.

Overview of Variable-Speed Power-Turbine Research

NASA Technical Reports Server (NTRS)

Welch, Gerard E.

2011-01-01

The vertical take-off and landing (VTOL) and high-speed cruise capability of the NASA Large Civil Tilt-Rotor (LCTR) notional vehicle is envisaged to enable increased throughput in the national airspace. A key challenge of the LCTR is the requirement to vary the main rotor speeds from 100% at take-off to near 50% at cruise as required to minimize mission fuel burn. The variable-speed power-turbine (VSPT), driving a fixed gear-ratio transmission, provides one approach for effecting this wide speed variation. The key aerodynamic and rotordynamic challenges of the VSPT were described in the FAP Conference presentation. The challenges include maintaining high turbine efficiency at high work factor, wide (60 deg.) of incidence variation in all blade rows due to the speed variation, and operation at low Reynolds numbers (with transitional flow). The PT -shaft of the VSPT must be designed for safe operation in the wide speed range required, and therefore poses challenges associated with rotordynamics. The technical challenges drive research activities underway at NASA. An overview of the NASA SRW VSPT research activities was provided. These activities included conceptual and preliminary aero and mechanical (rotordynamics) design of the VSPT for the LCTR application, experimental and computational research supporting the development of incidence tolerant blading, and steps toward component-level testing of a variable-speed power-turbine of relevance to the LCTR application.

Design challenges in transdiagnostic psychotherapy research: Comparing Transdiagnostic Behavior Therapy (TBT) to existing evidence-based psychotherapy in veterans with affective disorders.

PubMed

Gros, Daniel F

2015-07-01

To address the limitations of disorder-specific approaches, newer transdiagnostic approaches to psychotherapy have been developed to provide a single treatment that is capable of addressing several, related disorders. However, the recruitment of multiple diagnoses presents many challenges to the traditional design of psychotherapy randomized controlled trials (RCTs). The goal of the manuscript is to present the challenges and rationale for designing a RCT for transdiagnostic treatment to inform and aid in the development of future investigations. A recently funded and ongoing RCT for Transdiagnostic Behavior Therapy (TBT) is used as an example to discuss the related design challenges. The TBT study involves the recruitment of 96 veteran participants with any of the following eight principal diagnoses: posttraumatic stress disorder, panic disorder, social anxiety disorder, obsessive compulsive disorder, generalized anxiety disorder, specific phobia, major depressive disorder, or persistent depressive disorder. Within the TBT study, participants will complete a semi-structured diagnostic interview and a series of transdiagnostic self-report measures to determine eligibility and assess baseline symptomatology. Qualifying participants will be randomized to TBT or control psychotherapy. Additional assessments will be completed at post-treatment and 6-month follow-up. Due to the transdiagnostic nature of the sample, adjustments to the recruitment and randomization procedures, selection of measures, selection of control psychotherapy, and analysis plan were required. These adjustments have implications to future trials on transdiagnostic psychotherapy protocols as well as future research in line with the transdiagnostic focus of the National Institute of Mental Health's Research Domain Criteria (RDoC) funding strategy. Published by Elsevier Inc.

Managing the posterior polar cataract: An update

PubMed Central

Vasavada, Abhay R; Vasavada, Vaishali A

2017-01-01

Posterior polar cataracts (PPC) have always been a challenge for cataract surgeons due to their inherently higher propensity for posterior capsule rupture. Over the years, several technical modifications have been suggested to enhance safety and reduce posterior capsule rupture rates in these polar cataracts. This review article tries to present the various techniques and strategies to published in literature to manage PPCs. It also discusses pearls for making surgery more reproducible and consistent, as well as the role of newer diagnostic and surgical technology based on the published literature on the subject. PMID:29208815

Anticholinergic Toxicity Secondary to Overuse of Topricin Cream, a Homeopathic Medication

PubMed Central

Regina, Angela; Jesin, Raphael C; Deeb, Liliane; Steinberg, Eric; Majlesi, Nima

2018-01-01

Adverse reactions from over-the-counter medications present a challenge to physicians. Homeopathic medicine is an alternative practice, originating in Germany and gaining popularity in the United States. It utilizes dilute preparations of substances in order to treat and cure disease. Patients may potentially suffer serious effects from the use of these products as the contents and concentrations are often unclear. Here, we describe a case of suspected atropine toxicity due to the overuse of a topical homeopathic cream, Topricin, which contains belladonna, a plant containing atropine. PMID:29736357

Ongoing measles outbreak in Wallonia, Belgium, December 2016 to March 2017: characteristics and challenges.

PubMed

Grammens, Tine; Schirvel, Carole; Leenen, Sylvie; Shodu, Nathalie; Hutse, Veronik; Mendes da Costa, Elise; Sabbe, Martine

2017-04-27

We describe characteristics of an ongoing measles outbreak in Wallonia, Belgium, and difficulties in control measures implementation. As at 12 March 2017, 177 measles cases were notified, of which 50% were 15 years and older, 49% female. Atypical clinical presentation and severe complications, mainly among adults, in combination with late notification, low or unknown vaccination coverage of contacts, infected healthcare workers and increased workload due to contact tracing, are the main concerns for outbreak management. This article is copyright of The Authors, 2017.

DERMA: A Melanoma Diagnosis Platform Based on Collaborative Multilabel Analog Reasoning

PubMed Central

Golobardes, Elisabet; Corral, Guiomar; Puig, Susana; Malvehy, Josep

2014-01-01

The number of melanoma cancer-related death has increased over the last few years due to the new solar habits. Early diagnosis has become the best prevention method. This work presents a melanoma diagnosis architecture based on the collaboration of several multilabel case-based reasoning subsystems called DERMA. The system has to face up several challenges that include data characterization, pattern matching, reliable diagnosis, and self-explanation capabilities. Experiments using subsystems specialized in confocal and dermoscopy images have provided promising results for helping experts to assess melanoma diagnosis. PMID:24578629

Foraminoplastic transfacet epidural endoscopic approach for removal of intraforaminal disc herniation at the L5-S1 level

PubMed Central

Kaczmarczyk, Jacek; Nowakowski, Andrzej; Sulewski, Adam

2014-01-01

Transforaminal endoscopic disc removal in the L5-S1 motion segment of the lumbar spine creates a technical challenge due to anatomical reasons and individual variability. The majority of surgeons prefer a posterior classical or minimally invasive approach. There is only one foraminoplastic modification of the technique in the literature so far. In this paper we present a new technique with a foraminoplastic transfacet approach that may be suitable in older patients with advanced degenerative disease of the spine. PMID:24729817

The risks and efficacy of solar geoengineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keith, David

2012-12-05

Solar geoengineering may enable a significant reduction in climate risks by partially offsetting climate change due to increasing greenhouse gases, however this emerging technology entails novel risks and uncertainties along with serious challenges to global governance. I will attempt a rough summary of the physics of solar geoengineering and present recent findings regarding (a) the climate's response to radiative forcing by stratospheric aerosols, (b) methods of producing appropriate aerosol distributions, and (c) risks. In closing I will discuss the trade-off between solar geoengineering, emissions reductions and adaptation in climate policy.

Diagnostic Approaches to Metastatic Hepatocellular Carcinoma of the Orbit.

PubMed

Geske, Michael J; Bloomer, Michele M; Kersten, Robert C; Vagefi, M Reza

Orbital metastasis of hepatocellular carcinoma is exceedingly rare and caries a grave prognosis. Three cases of metastatic orbital hepatocellular carcinoma in which the primary tumor was initially unknown and the diagnostic challenges encountered are presented. With hepatocellular carcinoma, open biopsy and palliative tumor debulking has an increased bleeding risk due to the highly vascular nature of the tumor and coagulopathy associated with chronic liver disease. As an alternative, fine needle aspiration biopsy should be considered for hepatocellular carcinoma with a readily accessible mass and the availability of an experienced cytopathologist.

o-HETM: An Online Hierarchical Entity Topic Model for News Streams

DTIC Science & Technology

2015-05-22

p(ed,i|z, c, e−(d,i), η̃) (3) Due to space limitation, we don’t present how to commutate the distributions in detail. For more details, we can refer... India /LOC sanctions|East/LOC Netanyahu|Netanyahu/PER Iranian|Middle/LOC peace|Chen/PER publicly|1967/TIME challenges|Palin/PER zombie|Russia/LOC affair...1m Sarah Palin uses India visit to fuel rumours of her White House ambitions Fig. 3. The main part of the topic hierarchy about the “2012 US election

Horizontal atmospheric turbulence, beam propagation, and modeling

NASA Astrophysics Data System (ADS)

Wilcox, Christopher C.; Santiago, Freddie; Martinez, Ty; Judd, K. Peter; Restaino, Sergio R.

2017-05-01

The turbulent effect from the Earth's atmosphere degrades the performance of an optical imaging system. Many studies have been conducted in the study of beam propagation in a turbulent medium. Horizontal beam propagation and correction presents many challenges when compared to vertical due to the far harsher turbulent conditions and increased complexity it induces. We investigate the collection of beam propagation data, analysis, and use for building a mathematical model of the horizontal turbulent path and the plans for an adaptive optical system to use this information to correct for horizontal path atmospheric turbulence.

Ground systems and operations concepts for the Space Infrared Telescope Facility (SIRTF)

NASA Technical Reports Server (NTRS)

Miller, Richard B.

1991-01-01

Key requirements and ground systems implementation strategy for SIRTF which presents a significant challenge in the operational phase of the mission are discussed. The facility is aimed at reliably integrating a guaranteed time program, requests from about 200 guest observer teams per year, and observatory maintenance. SIRFT is characterized by the five-year life time due to cryogen boil-off which means that the ground system must be fully operational at launch and must operate with an efficiency and timeliness rarely achieved in previous space missions.

Diagnostic Dilemma of Hb Perth [β32(B14)Leu→Pro; HBB: c.98T > C] in Mainland China.

PubMed

Jiang, Hua; Yan, Jin-Mei; Li, Jian; Xie, Xing-Mei; Li, Dong-Zhi

2016-06-01

Unstable hemoglobin (Hb) variants represent a rare etiology of congenital hemolytic anemia. Correct diagnosis can be a challenge due to the relative rarity or lack of awareness of this disorder. We report an 18-month-old girl, who presented with a long-standing hemolytic anemia. Her diagnosis of unstable Hb Perth [β32(B14)Leu→Pro, HBB: c.98T > C] had not been made until gene sequencing of the β-globin gene was performed.

Scalable Static and Dynamic Community Detection Using Grappolo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halappanavar, Mahantesh; Lu, Hao; Kalyanaraman, Anantharaman

Graph clustering, popularly known as community detection, is a fundamental kernel for several applications of relevance to the Defense Advanced Research Projects Agency’s (DARPA) Hierarchical Identify Verify Exploit (HIVE) Pro- gram. Clusters or communities represent natural divisions within a network that are densely connected within a cluster and sparsely connected to the rest of the network. The need to compute clustering on large scale data necessitates the development of efficient algorithms that can exploit modern architectures that are fundamentally parallel in nature. How- ever, due to their irregular and inherently sequential nature, many of the current algorithms for community detectionmore » are challenging to parallelize. In response to the HIVE Graph Challenge, we present several parallelization heuristics for fast community detection using the Louvain method as the serial template. We implement all the heuristics in a software library called Grappolo. Using the inputs from the HIVE Challenge, we demonstrate superior performance and high quality solutions based on four parallelization heuristics. We use Grappolo on static graphs as the first step towards community detection on streaming graphs.« less

Utilization and Monetization of Healthcare Data in Developing Countries.

PubMed

Bram, Joshua T; Warwick-Clark, Boyd; Obeysekare, Eric; Mehta, Khanjan

2015-06-01

In developing countries with fledgling healthcare systems, the efficient deployment of scarce resources is paramount. Comprehensive community health data and machine learning techniques can optimize the allocation of resources to areas, epidemics, or populations most in need of medical aid or services. However, reliable data collection in low-resource settings is challenging due to a wide range of contextual, business-related, communication, and technological factors. Community health workers (CHWs) are trusted community members who deliver basic health education and services to their friends and neighbors. While an increasing number of programs leverage CHWs for last mile data collection, a fundamental challenge to such programs is the lack of tangible incentives for the CHWs. This article describes potential applications of health data in developing countries and reviews the challenges to reliable data collection. Four practical CHW-centric business models that provide incentive and accountability structures to facilitate data collection are presented. Creating and strengthening the data collection infrastructure is a prerequisite for big data scientists, machine learning experts, and public health administrators to ultimately elevate and transform healthcare systems in resource-poor settings.

Toxicological challenges to microbial bioethanol production and strategies for improved tolerance

DOE PAGES

Akinsho, Hannah; Rydzak, Thomas; Borole, Abhijeet P.; ...

2015-09-30

Bioethanol production output has increased steadily over the last two decades and is now beginning to become competitive with traditional liquid transportation fuels due to advances in engineering, the identification of new production host organisms, and the development of novel biodesign strategies. A significant portion of these efforts has been dedicated to mitigating the toxicological challenges encountered across the bioethanol production process. From the release of potentially cytotoxic or inhibitory compounds from input feedstocks, through the metabolic co-synthesis of ethanol and potentially detrimental byproducts, and to the potential cytotoxicity of ethanol itself, each stage of bioethanol production requires the applicationmore » of genetic or engineering controls that ensure the host organisms remain healthy and productive to meet the necessary economies required for large scale production. In addition, as production levels continue to increase, there is an escalating focus on the detoxification of the resulting waste streams to minimize their environmental impact. Thus, this review will present the major toxicological challenges encountered throughout each stage of the bioethanol production process and the commonly employed strategies for reducing or eliminating potential toxic effects.« less

Utilization and Monetization of Healthcare Data in Developing Countries

PubMed Central

Bram, Joshua T.; Warwick-Clark, Boyd; Obeysekare, Eric; Mehta, Khanjan

2015-01-01

Abstract In developing countries with fledgling healthcare systems, the efficient deployment of scarce resources is paramount. Comprehensive community health data and machine learning techniques can optimize the allocation of resources to areas, epidemics, or populations most in need of medical aid or services. However, reliable data collection in low-resource settings is challenging due to a wide range of contextual, business-related, communication, and technological factors. Community health workers (CHWs) are trusted community members who deliver basic health education and services to their friends and neighbors. While an increasing number of programs leverage CHWs for last mile data collection, a fundamental challenge to such programs is the lack of tangible incentives for the CHWs. This article describes potential applications of health data in developing countries and reviews the challenges to reliable data collection. Four practical CHW-centric business models that provide incentive and accountability structures to facilitate data collection are presented. Creating and strengthening the data collection infrastructure is a prerequisite for big data scientists, machine learning experts, and public health administrators to ultimately elevate and transform healthcare systems in resource-poor settings. PMID:26487984

Rising incidence and challenges of childhood diabetes. A mini review

PubMed Central

Cizza, G.; Brown, R.J.; Rothe, K.I.

2012-01-01

Approximately 215,000 people younger than 20 yr of age, or 1 in 500 children and adolescents, had diabetes in the United States in 2010 – and the incidence is rising. We still have insufficient knowledge about the precise mechanisms leading to the autoimmune mediated β-cell destruction in Type 1 diabetes, and the β-cell failure associated with insulin resistance in Type 2 diabetes. Long-term complications are similar: micro-and macrovascular disease occurs prematurely and presents an enormous burden on affected individuals, often as early as in middle age. In Type 1 diabetes, technological advances have clearly improved blood glucose management, but chronic peripheral over-insulinization remains a problem even with the most advanced systems. Thus, in Type 1 diabetes our research must focus on 1) finding the stimulus that ignites the immune response and 2) developing treatments that avoid hyperinsulinemia. In Type 2 diabetes in youth, the challenges start much earlier: most young patients do not even benefit from existing therapies due to non-compliance. Therefore, prevention of Type 2 diabetes and improvement of compliance, especially with non-pharmacological interventions, are the greatest challenges. PMID:22572768

Hydrolyzed whey protein prevents the development of food allergy to β-lactoglobulin in sensitized mice.

PubMed

Gomes-Santos, Ana Cristina; Fonseca, Roberta Cristelli; Lemos, Luisa; Reis, Daniela Silva; Moreira, Thaís Garcias; Souza, Adna Luciana; Silva, Mauro Ramalho; Silvestre, Marialice Pinto Coelho; Cara, Denise Carmona; Faria, Ana Maria Caetano

2015-01-01

Food allergy is an adverse immune response to dietary proteins. Hydrolysates are frequently used for children with milk allergy. However, hydrolysates effects afterwards are poorly studied. The aim of this study was to investigate the immunological consequences of hydrolyzed whey protein in allergic mice. For that, we developed a novel model of food allergy in BALB/c mice sensitized with alum-adsorbed β-lactoglobulin. These mice were orally challenged with either whey protein or whey hydrolysate. Whey-challenged mice had elevated levels of specific IgE and lost weight. They also presented gut inflammation, enhanced levels of SIgA and IL-5 as well as decreased production of IL-4 and IL-10 in the intestinal mucosa. Conversely, mice challenged with hydrolyzate maintained normal levels of IgE, IL-4 and IL-5 and showed no sign of gut inflammation probably due to increased IL-12 production in the gut. Thus, consumption of hydrolysate prevented the development of clinical signs of food allergy in mice. Copyright © 2015 Elsevier Inc. All rights reserved.

Manufacturing and Security Challenges in 3D Printing

NASA Astrophysics Data System (ADS)

Zeltmann, Steven Eric; Gupta, Nikhil; Tsoutsos, Nektarios Georgios; Maniatakos, Michail; Rajendran, Jeyavijayan; Karri, Ramesh

2016-07-01

As the manufacturing time, quality, and cost associated with additive manufacturing (AM) continue to improve, more and more businesses and consumers are adopting this technology. Some of the key benefits of AM include customizing products, localizing production and reducing logistics. Due to these and numerous other benefits, AM is enabling a globally distributed manufacturing process and supply chain spanning multiple parties, and hence raises concerns about the reliability of the manufactured product. In this work, we first present a brief overview of the potential risks that exist in the cyber-physical environment of additive manufacturing. We then evaluate the risks posed by two different classes of modifications to the AM process which are representative of the challenges that are unique to AM. The risks posed are examined through mechanical testing of objects with altered printing orientation and fine internal defects. Finite element analysis and ultrasonic inspection are also used to demonstrate the potential for decreased performance and for evading detection. The results highlight several scenarios, intentional or unintentional, that can affect the product quality and pose security challenges for the additive manufacturing supply chain.

Diagnostic challenges of childhood asthma.

PubMed

Bakirtas, Arzu

2017-01-01

Diagnosis of asthma in childhood is challenging. Both underdiagnosis and overdiagnosis of asthma are important issues. The present review gives information about challenging factors for an accurate diagnosis of childhood asthma. Although underdiagnosis of asthma in childhood has always been the most important diagnostic problem, overdiagnosis of asthma has also been increasingly recognized. This is probably due to diagnosis of asthma based on symptoms and signs alone. Demonstration of variable airflow obstruction by lung function tests is the most common asthma diagnostic tests used in practice and is therefore strongly recommended in children who can cooperate. Recently, an asthma guideline combining the clinical and economic evidences with sensitivity and specificity of diagnostic procedures was developed to improve accuracy of diagnosis and to avoid overdiagnosis. This guideline provided an algorithmic clinical and cost-effective approach and included fractional exhaled nitric oxide measurement as one of the diagnostic tests in addition to lung function. Diagnosis of asthma in children should be made by combining relevant history with at least two confirmatory diagnostic tests whenever possible. Diagnosis based on short-period treatment trials should be limited to young children who are unable to cooperate with these tests.

Co-Producing Accessible Climate Knowledge: Case Study of a Scientific Challenge

NASA Astrophysics Data System (ADS)

Bourqui, M.; Charriere, M. K. M.; Bolduc, C.

2016-12-01

This talk presents the process of and the lessons learned from a scientific challenge where climate scientists re-framed their research for the general public in interaction with members of the general public. This challenge was organized by Climanosco in the context of its launch in the fall 2015 and is due to end in September 2016. It led to the publication of 11 articles from scientific authors spanning 7 countries and engaged the participation of 24 members of the general public. The process of interaction between scientists and members of the general public took place along an extended peer-review process which included on-line community discussions and non-scientific review reports. Details of this interaction, as perceived by the participants and evaluated by a survey, will be discussed in this talk. On the longer term this co-production of accessible climate knowledge, which represents the main goal of the non-profit association Climanosco, is meant to serve as a reliable, research-based source, the decision makers but also the journalists, teachers and communities around the world.

RNA Interference in Insect Vectors for Plant Viruses.

PubMed

Kanakala, Surapathrudu; Ghanim, Murad

2016-12-12

Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. The last decade has witnessed a dramatic increase in the functional analysis of insect genes, especially those whose silencing results in mortality or interference with pathogen transmission. The identification of such candidates poses a major challenge for increasing the role of RNAi in pest control. Another challenge is to understand the RNAi machinery in insect cells and whether components that were identified in other organisms are also present in insect. This review will focus on summarizing success cases in which RNAi was used for silencing genes in insect vector for plant pathogens, and will be particularly helpful for vector biologists.

RNA Interference in Insect Vectors for Plant Viruses

PubMed Central

Kanakala, Surapathrudu; Ghanim, Murad

2016-01-01

Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. The last decade has witnessed a dramatic increase in the functional analysis of insect genes, especially those whose silencing results in mortality or interference with pathogen transmission. The identification of such candidates poses a major challenge for increasing the role of RNAi in pest control. Another challenge is to understand the RNAi machinery in insect cells and whether components that were identified in other organisms are also present in insect. This review will focus on summarizing success cases in which RNAi was used for silencing genes in insect vector for plant pathogens, and will be particularly helpful for vector biologists. PMID:27973446

Review and prospect of supersonic business jet design

NASA Astrophysics Data System (ADS)

Sun, Yicheng; Smith, Howard

2017-04-01

This paper reviews the environmental issues and challenges appropriate to the design of supersonic business jets (SSBJs). There has been a renewed, worldwide interest in developing an environmentally friendly, economically viable and technologically feasible supersonic transport aircraft. A historical overview indicates that the SSBJ will be the pioneer for the next generation of supersonic airliners. As a high-end product itself, the SSBJ will likely take a market share in the future. The mission profile appropriate to this vehicle is explored considering the rigorous environmental constraints. Mitigation of the sonic boom and improvements aerodynamic efficiency in flight are the most challenging features of civil supersonic transport. Technical issues and challenges associated with this type of aircraft are identified, and methodologies for the SSBJ design are discussed. Due to the tightly coupled issues, a multidisciplinary design, analysis and optimization environment is regarded as the essential approach to the creation of a low-boom low-drag supersonic aircraft. Industrial and academic organizations have an interest in this type of vehicle are presented. Their investments in SSBJ design will hopefully get civil supersonic transport back soon.

Preclinical evaluation of a chemically detoxified pneumolysin as pneumococcal vaccine antigen.

PubMed

Hermand, Philippe; Vandercammen, Annick; Mertens, Emmanuel; Di Paolo, Emmanuel; Verlant, Vincent; Denoël, Philippe; Godfroid, Fabrice

2017-01-02

The use of protein antigens able to protect against the majority of Streptococcus pneumoniae serotypes is envisaged as stand-alone and/or complement to the current capsular polysaccharide-based pneumococcal vaccines. Pneumolysin (Ply) is a key virulence factor that is highly conserved in amino acid sequence across pneumococcal serotypes, and therefore may be considered as a vaccine target. However, native Ply cannot be used in vaccines due to its intrinsic cytolytic activity. In the present work a completely, irreversibly detoxified pneumolysin (dPly) has been generated using an optimized formaldehyde treatment. Detoxi-fication was confirmed by dPly challenge in mice and histological analysis of the injection site in rats. Immunization with dPly elicited Ply-specific functional antibodies that were able to inhibit Ply activity in a hemolysis assay. In addition, immunization with dPly protected mice against lethal intranasal challenge with Ply, and intranasal immunization inhibited nasopharyngeal colonization after intranasal challenge with homologous or heterologous pneumococcal strain. Our findings supported dPly as a valid candidate antigen for further pneumococcal vaccine development.

Preclinical evaluation of a chemically detoxified pneumolysin as pneumococcal vaccine antigen

PubMed Central

Hermand, Philippe; Vandercammen, Annick; Mertens, Emmanuel; Di Paolo, Emmanuel; Verlant, Vincent; Denoël, Philippe; Godfroid, Fabrice

2017-01-01

ABSTRACT The use of protein antigens able to protect against the majority of Streptococcus pneumoniae serotypes is envisaged as stand-alone and/or complement to the current capsular polysaccharide-based pneumococcal vaccines. Pneumolysin (Ply) is a key virulence factor that is highly conserved in amino acid sesec-typsecquence across pneumococcal serotypes, and therefore may be considered as a vaccine target. However, native Ply cannot be used in vaccines due to its intrinsic cytolytic activity. In the present work a completely, irreversibly detoxified pneumolysin (dPly) has been generated using an optimized formaldehyde treatment. Detoxi-fication was confirmed by dPly challenge in mice and histological analysis of the injection site in rats. Immunization with dPly elicited Ply-specific functional antibodies that were able to inhibit Ply activity in a hemolysis assay. In addition, immunization with dPly protected mice against lethal intranasal challenge with Ply, and intranasal immunization inhibited nasopharyngeal colonization after intranasal challenge with homologous or heterologous pneumococcal strain. Our findings supported dPly as a valid candidate antigen for further pneumococcal vaccine development. PMID:27768518

External amplification of OCT swept-sources for challenging applications: from 10 mW to more than 120 mW

NASA Astrophysics Data System (ADS)

Rivard, Maxime; Villeneuve, Alain; Lamouche, Guy

2017-02-01

For bioimaging applications, commercial swept-sources currently provide enough power (tens of milliwatts) insuring good imaging condition without damaging the tissues. For industrial applications, more power is needed since the amount of light collected can be very low due to challenging measurement conditions or due to poor sample reflectivity. To address this challenge, we explore three different setups to externally amplify the output of a commercial swept-source: a booster semiconductor optical amplifier (BOA), an erbium-doped fiber amplifier (EDFA) and a combination of both. These external amplification setups allow the exploration of emerging OCT applications without the need to develop new hardware.

Delivering Global Environmental Change Science Through Documentary Film

NASA Astrophysics Data System (ADS)

Dodgson, K.; Byrne, J. M.; Graham, J. R.

2010-12-01

Communicating authentic science to society presents a significant challenge to researchers. This challenge stems from unfortunate misrepresentation and misunderstanding in the mainstream media, particularly in relation to science on global environmental change. This has resulted in a lower level of confidence and interest amongst audiences in regards to global environmental change and anthropogenic climate change discussions. This project describes a new form of documentary film that aspires to break this trend and increase audiences’ interest, reinvigorating discussion about global environmental change. The documentary film adopts a form that marries traditional scientific presentation with the high entertainment value of narrative storytelling. This format maintains the authenticity of the scientific message and ensures audience engagement throughout the entire presentation due to the fact that a sense of equality and intimacy between the audience and the scientists is achieved. The film features interviews with scientists studying global environmental change and opens with a comparison of authentic scientific information and the mainstream media’s presentation, and subsequent public opinion. This enables an analysis of the growing disconnect between society and the scientific community. Topics investigated include: Arctic ice melt, coastal zone hypoxia, tropical cyclones and acidification. Upon completion of the film, public and private screenings with predetermined audience demographics will be conducted using a short, standardized survey to gain feedback regarding the audience’s overall review of the presentation. In addition to the poster, this presentation features an extended trailer for the documentary film.

Gelatin controversies in food, pharmaceuticals, and personal care products: Authentication methods, current status, and future challenges.

PubMed

Ali, Eaqub; Sultana, Sharmin; Hamid, Sharifah Bee Abd; Hossain, Motalib; Yehya, Wageeh A; Kader, Abdul; Bhargava, Suresh K

2018-06-13

Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.

Method meets application: on the use of earthquake scenarios in community-based disaster preparedness and response

NASA Astrophysics Data System (ADS)

Sargeant, S.; Sorensen, M. B.

2011-12-01

More than 50% of the world's population now live in urban areas. In less developed countries, future urban population increase will be due to natural population growth and rural-to-urban migration. As urban growth continues, the vulnerability of those living in these areas is also increasing. This presents a wide variety of challenges for humanitarian organisations that often have more experience of disaster response in rural settings rather than planning for large urban disasters. The 2010 Haiti earthquake highlighted the vulnerability of these organisations and the communities that they seek to support. To meet this challenge, a key consideration is how scientific information can support the humanitarian sector and their working practices. Here we review the current state of earthquake scenario modelling practice, with special focus on scenarios to be used in disaster response and response planning, and present an evaluation of how the field looks set to evolve. We also review current good practice and lessons learned from previous earthquakes with respect to planning for and responding to earthquakes in urban settings in the humanitarian sector, identifying key sectoral priorities. We then investigate the interface between these two areas to investigate the use of earthquake scenarios in disaster response planning and identify potential challenges both with respect to development of scientific models and their application on the ground.

Challenges in fitting a hearing aid to a severely collapsed ear canal and mixed hearing loss.

PubMed

Oeding, Kristi; Valente, Michael; Chole, Richard

2012-04-01

Collapsed ear canals typically occur when an outside force, such as a headset for audiometric testing, is present. However, when a collapsed ear canal occurs without external pressure, this creates a challenge not only for performing audiometric testing but also for coupling a hearing aid to the ear canal. This case report highlights the challenges associated with fitting a hearing aid on a patient with a severe anterior-posterior collapsed ear canal with a mixed hearing loss. A 67-yr-old female originally presented to Washington University in St. Louis School of Medicine in 1996 with a long-standing history of bilateral otosclerosis. She had chronic ear infections in the right ear and a severely collapsed ear canal in the left ear and was fit with a bone anchored hearing aid (BAHA®) on the right side in 2003. However, benefit from the BAHA started to decrease due to changes in hearing, and a different hearing solution was needed. It was proposed that a hearing aid be fit to her collapsed left ear canal; however, trying to couple a hearing aid to the collapsed ear canal required unique noncustom earmold solutions. This case study highlights some of the obstacles and potential solutions for coupling a hearing aid to a severely collapsed ear canal. American Academy of Audiology.

Occupational vocal cord dysfunction due to exposure to wood dust and xerographic toner.

PubMed

Muñoz, Xavier; Roger, Alex; De la Rosa, David; Morell, Ferran; Cruz, Maria J

2007-04-01

Vocal cord dysfunction is a poorly understood entity that is often misdiagnosed as asthma. Both irritant and non-irritant vocal cord dysfunction have been described. This report presents two cases of irritant vocal cord dysfunction secondary to specific environmental exposure, the first to iroko and western red cedar wood (a carpenter) and the second to xerographic printing toner (a secretary). Several tests were performed, including chest radiographs, measurements of total serum immunoglobulin E, skin prick tests with common pneumoallergens (as well as iroko and western red cedar in the first case), pulmonary function studies, methacholine challenge testing, specific inhalation challenge performed with suspected agents in a single-blinded fashion, and peak expiratory flow testing and fiberoptic rhinolaryngoscopy (in case 1). During the specific inhalation challenge, the patients showed dysphonia, chest tightness, inspiratory stridor, and flattening of the inspiratory limb of the maximum flow-volume loop in spirometry, with no significant decreases in the level of forced expiratory volume in 1 second; fiberoptic rhinolaryngoscopy confirmed the diagnosis of vocal cord dysfunction in case 1. It is important to know that agents that can cause occupational asthma can also cause vocal cord dysfunction. The mechanisms by which these agents produce vocal cord dysfunction are unknown. The differences in the clinical presentation of the patients described relative to the reported cases suggest that more than one pathophysiological mechanism may be implicated in the genesis of this entity.

Perceptual uncertainty and line-call challenges in professional tennis

PubMed Central

Mather, George

2008-01-01

Fast-moving sports such as tennis require both players and match officials to make rapid accurate perceptual decisions about dynamic events in the visual world. Disagreements arise regularly, leading to disputes about decisions such as line calls. A number of factors must contribute to these disputes, including lapses in concentration, bias and gamesmanship. Fundamental uncertainty or variability in the sensory information supporting decisions must also play a role. Modern technological innovations now provide detailed and accurate physical information that can be compared against the decisions of players and officials. The present paper uses this psychophysical data to assess the significance of perceptual limitations as a contributor to real-world decisions in professional tennis. A detailed analysis is presented of a large body of data on line-call challenges in professional tennis tournaments over the last 2 years. Results reveal that the vast majority of challenges can be explained in a direct highly predictable manner by a simple model of uncertainty in perceptual information processing. Both players and line judges are remarkably accurate at judging ball bounce position, with a positional uncertainty of less than 40 mm. Line judges are more reliable than players. Judgements are more difficult for balls bouncing near base and service lines than those bouncing near side and centre lines. There is no evidence for significant errors in localization due to image motion. PMID:18426755

Perceptual uncertainty and line-call challenges in professional tennis.

PubMed

Mather, George

2008-07-22

Fast-moving sports such as tennis require both players and match officials to make rapid accurate perceptual decisions about dynamic events in the visual world. Disagreements arise regularly, leading to disputes about decisions such as line calls. A number of factors must contribute to these disputes, including lapses in concentration, bias and gamesmanship. Fundamental uncertainty or variability in the sensory information supporting decisions must also play a role. Modern technological innovations now provide detailed and accurate physical information that can be compared against the decisions of players and officials. The present paper uses this psychophysical data to assess the significance of perceptual limitations as a contributor to real-world decisions in professional tennis. A detailed analysis is presented of a large body of data on line-call challenges in professional tennis tournaments over the last 2 years. Results reveal that the vast majority of challenges can be explained in a direct highly predictable manner by a simple model of uncertainty in perceptual information processing. Both players and line judges are remarkably accurate at judging ball bounce position, with a positional uncertainty of less than 40mm. Line judges are more reliable than players. Judgements are more difficult for balls bouncing near base and service lines than those bouncing near side and centre lines. There is no evidence for significant errors in localization due to image motion.

Water-Related Impacts of Climate Change on Agriculture and Subsequently on Public Health: A Review for Generalists with Particular Reference to Pakistan.

PubMed

Ahmed, Toqeer; Scholz, Miklas; Al-Faraj, Furat; Niaz, Wajeeha

2016-10-27

Water-related impacts due to change in climatic conditions ranging from water scarcity to intense floods and storms are increasing in developing countries like Pakistan. Water quality and waterborne diseases like hepatitis, cholera, typhoid, malaria and dengue fever are increasing due to chaotic urbanization, industrialization, poor hygienic conditions, and inappropriate water management. The morbidity rate is high due to lack of health care facilities, especially in developing countries. Organizations linked to the Government of Pakistan (e.g., Ministry of Environment, Ministry of Climate Change, Planning and Development, Ministry of Forest, Irrigation and Public Health, Pakistan Meteorological Department, National Disaster Management, Pakistan Agricultural Research Centre, Pakistan Council for Research in Water Resources, and Global Change Impact Study Centre), United Nation organizations, provincial government departments, non-governmental organizations (e.g., Global Facility and Disaster Reduction), research centers linked to universities, and international organizations (International Institute for Sustainable Development, Food and Agriculture, Global Climate Fund and World Bank) are trying to reduce the water-related impacts of climate change, but due to lack of public awareness and health care infrastructure, the death rate is steadily increasing. This paper critically reviews the scientific studies and reports both at national and at international level benefiting generalists concerned with environmental and public health challenges. The article underlines the urgent need for water conservation, risk management, and the development of mitigation measures to cope with the water-related impacts of climate change on agriculture and subsequently on public health. Novel solutions and bioremediation methods have been presented to control environmental pollution and to promote awareness among the scientific community. The focus is on diverse strategies to handle the forthcoming challenges associated with water resources management.

Water-Related Impacts of Climate Change on Agriculture and Subsequently on Public Health: A Review for Generalists with Particular Reference to Pakistan

PubMed Central

Ahmed, Toqeer; Scholz, Miklas; Al-Faraj, Furat; Niaz, Wajeeha

2016-01-01

Water-related impacts due to change in climatic conditions ranging from water scarcity to intense floods and storms are increasing in developing countries like Pakistan. Water quality and waterborne diseases like hepatitis, cholera, typhoid, malaria and dengue fever are increasing due to chaotic urbanization, industrialization, poor hygienic conditions, and inappropriate water management. The morbidity rate is high due to lack of health care facilities, especially in developing countries. Organizations linked to the Government of Pakistan (e.g., Ministry of Environment, Ministry of Climate Change, Planning and Development, Ministry of Forest, Irrigation and Public Health, Pakistan Meteorological Department, National Disaster Management, Pakistan Agricultural Research Centre, Pakistan Council for Research in Water Resources, and Global Change Impact Study Centre), United Nation organizations, provincial government departments, non-governmental organizations (e.g., Global Facility and Disaster Reduction), research centers linked to universities, and international organizations (International Institute for Sustainable Development, Food and Agriculture, Global Climate Fund and World Bank) are trying to reduce the water-related impacts of climate change, but due to lack of public awareness and health care infrastructure, the death rate is steadily increasing. This paper critically reviews the scientific studies and reports both at national and at international level benefiting generalists concerned with environmental and public health challenges. The article underlines the urgent need for water conservation, risk management, and the development of mitigation measures to cope with the water-related impacts of climate change on agriculture and subsequently on public health. Novel solutions and bioremediation methods have been presented to control environmental pollution and to promote awareness among the scientific community. The focus is on diverse strategies to handle the forthcoming challenges associated with water resources management. PMID:27801802

From drones to ASO: Using 'Structure-From-Motion' photogrammetry to quantify variations in snow depth at multiple scales

NASA Astrophysics Data System (ADS)

Skiles, M.

2017-12-01

The ability to accurately measure and manage the natural snow water reservoir in mountainous regions has its challenges, namely mapping of snowpack depth and snow water equivalent (SWE). Presented here is a scalable method that differentially maps snow depth using Structure from Motion (SfM); a photogrammetric technique that uses 2d images to create a 3D model/Digital Surface Model (DSM). There are challenges with applying SfM to snow, namely, relatively uniform snow brightness can make it difficult to produce quality images needed for processing, and vegetation can limit the ability to `see' through the canopy to map both the ground and snow beneath. New techniques implemented in the method to adapt to these challenges will be demonstrated. Results include a time series at (1) the plot scale, imaged with an unmanned areal vehicle (DJI Phantom 2 adapted with Sony A5100) over the Utah Department of Transportation Atwater Study Plot in Little Cottonwood Canyon, UT, and at (2) the mountain watershed scale, imaged from the RGB camera aboard the Airborne Snow Observatory (ASO), over the headwaters of the Uncompahgre River in the San Juan Mountains, CO. At the plot scale we present comparisons to measured snow depth, and at the watershed scale we present comparisons to the ASO lidar DSM. This method is of interest due to its low cost relative to lidar, making it an accessible tool for snow research and the management of water resources. With advancing unmanned aerial vehicle technology there are implications for scalability to map snow depth, and SWE, across large basins.

Increasing clinical relevance in oral radiology: Benefits and challenges when implementing digital assessment.

PubMed

de Lange, T; Møystad, A; Torgersen, G R

2018-02-13

The aims of the study were to investigate benefits and challenges in implementing a digital examination and study the clinical relevance of the digital examination in relation to clinical training and practice. The study was based on semi-structured focus-group interviews from two distinct student populations (2016 and 2017) in a bachelor programme in dental hygiene. In addition, conversational data from a plenary discussion from the whole second student population (2017) were collected and analysed. The data were approached on basis of content analysis. A benefit experienced in the digital examination was the ease in typing and editing answers on the computer. This suggests an increased effectiveness in computer-based compared to analogue examinations. An additional advantage was the experienced relevance of the examination related to the clinic. This finding refers not only to the digital presentations of images, but also to the entire setting in the clinic and dental practice. The limitations reported by the students were non-optimal viewing conditions for presenting radiographic images and difficulties in obtaining an overview of the assignments compared to paper-based examinations due to the linear digital examination format. The last finding on lacking overview revealed an influence on student performances which should be taken seriously in designing digital examinations. In conclusion, the digital layout increases efficiency and clinical relevance of examinations to a certain extent. Obstacles were found in limitations related to image presentation and lack of overview of the examination. The latter challenge raises questions related to developing suitable assessment software. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Aerodynamic Challenges for the Mars Science Laboratory Entry, Descent and Landing

NASA Technical Reports Server (NTRS)

Schoenenberger, Mark; Dyakonov, Artem; Buning, Pieter; Scallion, William; Norman, John Van

2009-01-01

An overview of several important aerodynamics challenges new to the Mars Science Laboratory (MSL) entry vehicle are presented. The MSL entry capsule is a 70 degree sphere cone-based on the original Mars Viking entry capsule. Due to payload and landing accuracy requirements, MSL will be flying at the highest lift-to-drag ratio of any capsule sent to Mars (L/D = 0.24). The capsule will also be flying a guided entry, performing bank maneuvers, a first for Mars entry. The system's mechanical design and increased performance requirements require an expansion of the MSL flight envelope beyond those of historical missions. In certain areas, the experience gained by Viking and other recent Mars missions can no longer be claimed as heritage information. New analysis and testing is re1quired to ensure the safe flight of the MSL entry vehicle. The challenge topics include: hypersonic gas chemistry and laminar-versus-turbulent flow effects on trim angle, a general risk assessment of flying at greater angles-of-attack than Viking, quantifying the aerodynamic interactions induced by a new reaction control system and a risk assessment of recontact of a series of masses jettisoned prior to parachute deploy. An overview of the analysis and tests being conducted to understand and reduce risk in each of these areas is presented. The need for proper modeling and implementation of uncertainties for use in trajectory simulation has resulted in a revision of prior models and additional analysis for the MSL entry vehicle. The six degree-of-freedom uncertainty model and new analysis to quantify roll torque dispersions are presented.

A retrospective evaluation of challenges in urethral stricture management in a tertiary care centre of a poor resource community.

PubMed

Olajide, Abimbola Olaniyi; Olajide, Folakemi Olajumoke; Kolawole, Oladapo Adedayo; Oseni, Ismaila; Ajayi, Adewale Idowu

2013-11-01

Management of urethral stricture has evolved over the years with better understanding of the pathology, advancement in imaging, and introduction of several techniques of urethral reconstruction. In sub-Saharan Africa, advancement in management of urethral stricture may not be comparable with what obtained in most developed nations because of problems like late presentation and persistence of rare complications still reported in recent literature from the region. We set to evaluate the challenges faced by urologists involved in the management of urethral strictures in Osogbo, a poor resource community in south western Nigeria. A retrospective study was performed in the urology unit of Ladoke Akintola University of Technology Teaching Hospital, Osogbo, Nigeria between July 2007 and July 2012. Information was retrieved from patients' clinical notes and analyzed using statistical package for social sciences (SPSS) version 16.0. Eighty-four patients were treated during the period of study, their ages ranged between 19 and 89 years with the mean age of 52.3 years. The mean duration of symptoms before presentation was 3 years and 1 month. Inflammation resulting from sexually transmitted infection was the commonest etiology and more than 50% of the patients presented with complications. Sixteen patients (19.1%) received no treatment due to lack of fund. More than 90% were dependent, unemployed or underemployed. Single stage reconstruction by urethral substitution was the commonest form of repair with the restenosis rate of 4.4%. Prevalent socio-cultural and economic situation in south western Nigeria have added some peculiar challenges to the management of urethral stricture in the region.

Patients with mental problems - the most defenseless travellers.

PubMed

Felkai, Peter; Kurimay, Tamas

2017-09-01

Severe mental illness occurring abroad is a difficult situation for patients, their families, and for the local medical community. Patients with mental problem are doublely stigmatized due to their mental illness and because they are foreigners in an unfamiliar country. The appropriate treatment is often delayed, while patients are often dealt with in a manner that violates their human rights. Moreover, repatriation - which is vital in this case - is often delayed due to the lack of international protocols for the transportation and treatment of mentally ill travelers. Authors analyzed several factors related to acute mental health problems during travel: the etiology of symptoms, the appropriate treatment possibilities abroad, and medical evacuation and repatriation of the psychotic patient. The article presents a brief review of travel-related mental disorders, the epidemiology of mental health issues faced by travelers, and the significance of pre-travel advice for these patients. The first problem is to recognize (and redress) the particular challenges faced by a psychotic patient in a strange country. The second challenge is to prepare the patients, often in a poor psychiatric state, for medical evacuation by commercial aircraft. Another important question is the best way to take the patient through customs and security control. All of these, as yet unresolved, issues can make the mental patient virtually defenseless. Although timely repatriation of a mentally ill patient is vital and urgent, most travel insurance policies exclude treatment and repatriation costs incurred due to acute mental illness. The high cost of treatment and repatriation must be paid by the patient or their family, which could lead to severe financial strain or insolvency. Changing the approaches taken by the local mental health care community, police, airport security, and insurance companies remain a challenge for psychiatrists. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Student Rights Associated with Disciplinary and Academic Hearings and Sanctions

ERIC Educational Resources Information Center

La Roche, Claire R.

2005-01-01

This paper examines whether students have due process rights associated with disciplinary and academic hearings. Constitutional challenges, case law, and the requirements of due process are discussed. Suggestions are made for procedures a school should follow to fulfill the requirements of due process.

Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives

NASA Astrophysics Data System (ADS)

Yao, Jianyong

2018-06-01

Hydraulic servo system plays a significant role in industries, and usually acts as a core point in control and power transmission. Although linear theory-based control methods have been well established, advanced controller design methods for hydraulic servo system to achieve high performance is still an unending pursuit along with the development of modern industry. Essential nonlinearity is a unique feature and makes model-based nonlinear control more attractive, due to benefit from prior knowledge of the servo valve controlled hydraulic system. In this paper, a discussion for challenges in model-based nonlinear control, latest developments and brief perspectives of hydraulic servo systems are presented: Modelling uncertainty in hydraulic system is a major challenge, which includes parametric uncertainty and time-varying disturbance; some specific requirements also arise ad hoc difficulties such as nonlinear friction during low velocity tracking, severe disturbance, periodic disturbance, etc.; to handle various challenges, nonlinear solutions including parameter adaptation, nonlinear robust control, state and disturbance observation, backstepping design and so on, are proposed and integrated, theoretical analysis and lots of applications reveal their powerful capability to solve pertinent problems; and at the end, some perspectives and associated research topics (measurement noise, constraints, inner valve dynamics, input nonlinearity, etc.) in nonlinear hydraulic servo control are briefly explored and discussed.

Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study

PubMed Central

Rudyanto, Rina D.; Kerkstra, Sjoerd; van Rikxoort, Eva M.; Fetita, Catalin; Brillet, Pierre-Yves; Lefevre, Christophe; Xue, Wenzhe; Zhu, Xiangjun; Liang, Jianming; Öksüz, İlkay; Ünay, Devrim; Kadipaşaogandcaron;lu, Kamuran; Estépar, Raúl San José; Ross, James C.; Washko, George R.; Prieto, Juan-Carlos; Hoyos, Marcela Hernández; Orkisz, Maciej; Meine, Hans; Hüllebrand, Markus; Stöcker, Christina; Mir, Fernando Lopez; Naranjo, Valery; Villanueva, Eliseo; Staring, Marius; Xiao, Changyan; Stoel, Berend C.; Fabijanska, Anna; Smistad, Erik; Elster, Anne C.; Lindseth, Frank; Foruzan, Amir Hossein; Kiros, Ryan; Popuri, Karteek; Cobzas, Dana; Jimenez-Carretero, Daniel; Santos, Andres; Ledesma-Carbayo, Maria J.; Helmberger, Michael; Urschler, Martin; Pienn, Michael; Bosboom, Dennis G.H.; Campo, Arantza; Prokop, Mathias; de Jong, Pim A.; Ortiz-de-Solorzano, Carlos; Muñoz-Barrutia, Arrate; van Ginneken, Bram

2016-01-01

The VESSEL12 (VESsel SEgmentation in the Lung) challenge objectively compares the performance of different algorithms to identify vessels in thoracic computed tomography (CT) scans. Vessel segmentation is fundamental in computer aided processing of data generated by 3D imaging modalities. As manual vessel segmentation is prohibitively time consuming, any real world application requires some form of automation. Several approaches exist for automated vessel segmentation, but judging their relative merits is difficult due to a lack of standardized evaluation. We present an annotated reference dataset containing 20 CT scans and propose nine categories to perform a comprehensive evaluation of vessel segmentation algorithms from both academia and industry. Twenty algorithms participated in the VESSEL12 challenge, held at International Symposium on Biomedical Imaging (ISBI) 2012. All results have been published at the VESSEL12 website http://vessel12.grand-challenge.org. The challenge remains ongoing and open to new participants. Our three contributions are: (1) an annotated reference dataset available online for evaluation of new algorithms; (2) a quantitative scoring system for objective comparison of algorithms; and (3) performance analysis of the strengths and weaknesses of the various vessel segmentation methods in the presence of various lung diseases. PMID:25113321

Connecting the records: exploiting tephra deposits to help understand abrupt climate change

NASA Astrophysics Data System (ADS)

Davies, S. M.; Abbott, P. M.; Bourne, A. J.; Chapman, M.; Pearce, N. J. G.; Griggs, A. J.; Cook, E.

2016-12-01

The causal mechanism of abrupt climate change during the last glacial period remains a key challenge. Although these events are well-documented in a wide range of proxy records, the triggers and drivers remain poorly understood, largely due to the dating uncertainties that prevent the integration of different archives. Unravelling the lead/lag responses (hence cause and effect) between the Earth's climate components is limited by the challenges of synchronising palaeoclimate records on a common timescale. Here we present the potential and the challenges of optimising the use of cryptotephra deposits to precisely correlate the Greenland ice-cores with North Atlantic marine records. A series of new cryptotephra deposits have been identified in Greenland, increasing the scope of identifying coeval isochrons in the marine environment. This new framework, however, brings new challenges in the search for unique and robust geochemical fingerprints for unequivocal tephra correlations. As such, some tephra deposits are proposed to be more valuable than others and underpin key snapshots in time during the last glacial period. The North Atlantic Ash Zone II, for instance, represents the most widespread isochron and constrains the cooling of GI-15. Some tephra deposits in the ice-core record originate from ultra-distal sources beyond the North Atlantic region and we also explore the potential for establishing North Pacific linkages.

Diagnosing and treatment planning inadequate tooth display.

PubMed

Spear, F

2016-10-21

Some of the most challenging patients to produce a pleasing smile for are those who present with inadequate tooth display (either due to tooth position, the patient has normal size teeth, but they aren't exposed adequately to fill out the smile) or due to tooth size (the teeth are small, often due to tooth wear). The key to understanding how to manage these patients is to learn to understand the possible aetiologies that could produce the condition, and learn how to diagnose which aetiologies exist for your patient. Potential aetiologies for inadequate tooth display in patients with normal length unworn anterior teeth: excessive lip length; inadequate lip mobility; inadequate vertical eruption of the anterior teeth; inadequate facial prominence of the maxillary anterior teeth; vertical maxillary deficiency; and anterior maxillary deficiency.This article, the first in a British Dental Journal series on the topic of aesthetic dentistry, reviews the clinical findings consistent with diagnosing each of the above etiologies, and then reviews the treatment options available for correcting the inadequate tooth display.

Innovations in glaucoma surgery from Dr. Rajendra Prasad Centre for Ophthalmic Sciences.

PubMed

Dada, Tanuj; Midha, Neha; Shah, Pooja; Sidhu, Talvir; Angmo, Dewang; Sihota, Ramanjit

2017-02-01

Trabeculectomy surgery is the current standard of care in glaucoma for achieving a low target intraocular pressure if medical therapy is not adequate. Augmentation of trabeculectomy with antimetabolites brought a revolutionary change in the long-term success rates of trabeculectomy, but along with it came a plethora of complications. There still is a big window for therapeutic innovations on this subject. The foremost target for these innovations is to modulate the wound healing response after glaucoma drainage surgery. Achieving the desired balance between long-term success of filtering blebs versus early failure due to scarring of blebs and hypotony due to dysfunctional filtering blebs poses a unique challenge to the ophthalmologists. Alternatives to trabeculectomy such as glaucoma drainage devices and minimally invasive glaucoma surgeries cannot solve the problem of glaucoma blindness in our country, mainly due to their unpredictable results and unfavorable cost-benefit ratio. In this article, we present a summary of our innovations in glaucoma surgery to advance patient care by making it more effective, safer, and economical.

Advantages and Challenges of 10-Gbps Transmission on High-Density Interconnect Boards

NASA Astrophysics Data System (ADS)

Yee, Chang Fei; Jambek, Asral Bahari; Al-Hadi, Azremi Abdullah

2016-06-01

This paper provides a brief introduction to high-density interconnect (HDI) technology and its implementation on printed circuit boards (PCBs). The advantages and challenges of implementing 10-Gbps signal transmission on high-density interconnect boards are discussed in detail. The advantages (e.g., smaller via dimension and via stub removal) and challenges (e.g., crosstalk due to smaller interpair separation) of HDI are studied by analyzing the S-parameter, time-domain reflectometry (TDR), and transmission-line eye diagrams obtained by three-dimensional electromagnetic modeling (3DEM) and two-dimensional electromagnetic modeling (2DEM) using Mentor Graphics HyperLynx and Keysight Advanced Design System (ADS) electronic computer-aided design (ECAD) software. HDI outperforms conventional PCB technology in terms of signal integrity, but proper routing topology should be applied to overcome the challenge posed by crosstalk due to the tight spacing between traces.

The palm oil supply chain, deforestation and peat clearing

NASA Astrophysics Data System (ADS)

Boucher, D. H.

2013-12-01

The palm oil industry has expanded rapidly in the last two decades, particularly in Indonesia. A considerable amount of this expansion has been at the expense of forests and peatlands, resulting in considerable greenhouse gas emissions. Now the industry is faced with two new challenges. There is a possible oversupply on the global market due to recent expansion and the time lag between clearing and new production coming on line, which may depress prices considerably. Furthermore, there is increasing pressure to reduce the industry's impact on climate and biodiversity, exemplified by the commitment by the businesses of the Consumer Goods Forum to eliminate deforestation from their supply chains by 2020. This presentation will examine the interaction between these two challenges and its implications for the industry, in both southeast Asia and new regions of expansion, and how this interaction could transform the industry's mode of expansion in the coming decade.

Crab cavities: Past, present, and future of a challenging device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Q.

2015-05-03

In two-ring facilities operating with a crossing-angle collision scheme, luminosity can be limited due to an incomplete overlapping of the colliding bunches. Crab cavities then are introduced to restore head-on collisions by providing the destined opposite deflection to the head and tail of the bunch. An increase in luminosity was demonstrated at KEKB with global crab-crossing, while the Large Hardron Collider (LHC) at CERN currently is designing local crab crossing for the Hi-Lumi upgrade. Future colliders may investigate both approaches. In this paper, we review the challenges in the technology, and the implementation of crab cavities, while discussing experience inmore » earlier colliders, ongoing R&D, and proposed implementations for future facilities, such as HiLumi-LHC, CERN’s compact linear collider (CLIC), the international linear collider (ILC), and the electron-ion collider under design at BNL (eRHIC).« less

SWCD: a sliding window and self-regulated learning-based background updating method for change detection in videos

NASA Astrophysics Data System (ADS)

Işık, Şahin; Özkan, Kemal; Günal, Serkan; Gerek, Ömer Nezih

2018-03-01

Change detection with background subtraction process remains to be an unresolved issue and attracts research interest due to challenges encountered on static and dynamic scenes. The key challenge is about how to update dynamically changing backgrounds from frames with an adaptive and self-regulated feedback mechanism. In order to achieve this, we present an effective change detection algorithm for pixelwise changes. A sliding window approach combined with dynamic control of update parameters is introduced for updating background frames, which we called sliding window-based change detection. Comprehensive experiments on related test videos show that the integrated algorithm yields good objective and subjective performance by overcoming illumination variations, camera jitters, and intermittent object motions. It is argued that the obtained method makes a fair alternative in most types of foreground extraction scenarios; unlike case-specific methods, which normally fail for their nonconsidered scenarios.

Perioperative management of pulmonary hypertension during lung transplantation (a lesson for other anaesthesia settings).

PubMed

Rabanal, J M; Real, M I; Williams, M

2014-10-01

Patients with pulmonary hypertension are some of the most challenging for an anaesthesiologist to manage. Pulmonary hypertension in patients undergoing surgical procedures is associated with high morbidity and mortality due to right ventricular failure, arrhythmias and ischaemia leading to haemodynamic instability. Lung transplantation is the only therapeutic option for end-stage lung disease. Patients undergoing lung transplantation present a variety of challenges for anaesthesia team, but pulmonary hypertension remains the most important. The purpose of this article is to review the anaesthetic management of pulmonary hypertension during lung transplantation, with particular emphasis on the choice of anaesthesia, pulmonary vasodilator therapy, inotropic and vasopressor therapy, and the most recent intraoperative monitoring recommendations to optimize patient care. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Nonlinear mechanical resonators for ultra-sensitive mass detection

NASA Astrophysics Data System (ADS)

Datskos, P. G.; Lavrik, N. V.

2014-10-01

The fundamental sensitivity limit of an appropriately scaled down mechanical resonator can approach one atomic mass unit when only thermal noise is present in the system. However, operation of such nanoscale mechanical resonators is very challenging due to minuteness of their oscillation amplitudes and presence of multiple noise sources in real experimental environments. In order to surmount these challenges, we use microscale cantilever resonators driven to large amplitudes, far beyond their nonlinear instability onset. Our experiments show that such a nonlinear cantilever resonator, described analytically as a Duffing oscillator, has mass sensing performance comparable to that of much smaller resonators operating in a linear regime. We demonstrate femtogram level mass sensing that relies on a bifurcation point tracking that does not require any complex readout means. Our approaches enable straightforward detection of mass changes that are near the fundamental limit imposed by thermo-mechanical fluctuations.

Cell-based therapy technology classifications and translational challenges

PubMed Central

Mount, Natalie M.; Ward, Stephen J.; Kefalas, Panos; Hyllner, Johan

2015-01-01

Cell therapies offer the promise of treating and altering the course of diseases which cannot be addressed adequately by existing pharmaceuticals. Cell therapies are a diverse group across cell types and therapeutic indications and have been an active area of research for many years but are now strongly emerging through translation and towards successful commercial development and patient access. In this article, we present a description of a classification of cell therapies on the basis of their underlying technologies rather than the more commonly used classification by cell type because the regulatory path and manufacturing solutions are often similar within a technology area due to the nature of the methods used. We analyse the progress of new cell therapies towards clinical translation, examine how they are addressing the clinical, regulatory, manufacturing and reimbursement requirements, describe some of the remaining challenges and provide perspectives on how the field may progress for the future. PMID:26416686

Small-scale Detonation Velocity Measurement of Select CL-20 Cocrystals

NASA Astrophysics Data System (ADS)

Vuppuluri, Vasant; Gunduz, I. Emre; Son, Steven F.

2017-06-01

The challenge of developing novel energetic materials makes cocrystallization using existing energetic molecules useful. Cocrystallization of CL-20 with other high explosives such as HMX has been demonstrated previously to yield novel energetic materials and may have favorable detonation performance. However, detonation performance characterization of these cocrystals is challenging due to limited availability of material. Also, the contribution of bonding energy between coformers contained within the cocrystal is not well-understood. We present the comparison of steady detonation velocities of CL-20 cocrystals to their corresponding physical mixtures using microwave interferometry. With less than 1.5 g of the cocrystal material contained within 6.52 mm diameter charges, shot-to-shot variation in detonation velocity of only about 100 m/s are achievable with this technique. This variation is adequate to resolve relatively small differences between physical mixed explosive molecules and cocrystals.

Facile Synthesis of Nanoporous Pt-Y alloy with Enhanced Electrocatalytic Activity and Durability

NASA Astrophysics Data System (ADS)

Cui, Rongjing; Mei, Ling; Han, Guangjie; Chen, Jiyun; Zhang, Genhua; Quan, Ying; Gu, Ning; Zhang, Lei; Fang, Yong; Qian, Bin; Jiang, Xuefan; Han, Zhida

2017-02-01

Recently, Pt-Y alloy has displayed an excellent electrocatalytic activity for oxygen reduction reaction (ORR), and is regarded as a promising cathode catalyst for fuel cells. However, the bulk production of nanoscaled Pt-Y alloy with outstanding catalytic performance remains a great challenge. Here, we address the challenge through a simple dealloying method to synthesize nanoporous Pt-Y alloy (NP-PtY) with a typical ligament size of ~5 nm. By combining the intrinsic superior electrocatalytic activity of Pt-Y alloy with the special nanoporous structure, the NP-PtY bimetallic catalyst presents higher activity for ORR and ethanol oxidation reaction, and better electrocatalytic stability than the commercial Pt/C catalyst and nanoporous Pt alloy. The as-made NP-PtY holds great application potential as a promising electrocatalyst in proton exchange membrane fuel cells due to the advantages of facile preparation and excellent catalytic performance.

3D absolute shape measurement of live rabbit hearts with a superfast two-frequency phase-shifting technique

PubMed Central

Wang, Yajun; Laughner, Jacob I.; Efimov, Igor R.; Zhang, Song

2013-01-01

This paper presents a two-frequency binary phase-shifting technique to measure three-dimensional (3D) absolute shape of beating rabbit hearts. Due to the low contrast of the cardiac surface, the projector and the camera must remain focused, which poses challenges for any existing binary method where the measurement accuracy is low. To conquer this challenge, this paper proposes to utilize the optimal pulse width modulation (OPWM) technique to generate high-frequency fringe patterns, and the error-diffusion dithering technique to produce low-frequency fringe patterns. Furthermore, this paper will show that fringe patterns produced with blue light provide the best quality measurements compared to fringe patterns generated with red or green light; and the minimum data acquisition speed for high quality measurements is around 800 Hz for a rabbit heart beating at 180 beats per minute. PMID:23482151

New challenges in solar energy resource and forecasting in Greece

NASA Astrophysics Data System (ADS)

Kazantzidis, A.; Nikitidou, E.; Salamalikis, V.; Tzoumanikas, P.; Zagouras, A.

2018-05-01

Aerosols and clouds are the most important constituents in the atmosphere that affect the incoming solar radiation, either directly through absorbing and scattering processes or indirectly by changing the optical properties and lifetime of clouds. Under clear skies, aerosols become the dominant factor that affect the intensity of solar irradiance reaching the ground. Under cloudy skies, the high temporal and spatial variability of cloudiness is the key factor for the estimation of solar irradiance. In this study, recent research activities related to the climatology and the prediction of solar energy in Greece are presented with emphasis on new challenges in the climatology of global horizontal irradiance (GHI) and direct normal irradiance (DNI), the changes of DNI due to the decreasing aerosol optical depth and the short-term (15-240 min) forecasts of solar irradiance with the collaborative use of neural networks and satellite images.

Factors governing dissolution process of lignocellulosic biomass in ionic liquid: current status, overview and challenges.

PubMed

Badgujar, Kirtikumar C; Bhanage, Bhalchandra M

2015-02-01

The utilisation of non-feed lignocellulosic biomass as a source of renewable bio-energy and synthesis of fine chemical products is necessary for the sustainable development. The methods for the dissolution of lignocellulosic biomass in conventional solvents are complex and tedious due to the complex chemical ultra-structure of biomass. In view of this, recent developments for the use of ionic liquid solvent (IL) has received great attention, as ILs can solubilise such complex biomass and thus provides industrial scale-up potential. In this review, we have discussed the state-of-art for the dissolution of lignocellulosic material in representative ILs. Furthermore, various process parameters and their influence for biomass dissolution were reviewed. In addition to this, overview of challenges and opportunities related to this interesting area is presented. Copyright © 2014 Elsevier Ltd. All rights reserved.

CNS embryonal tumours: WHO 2016 and beyond.

PubMed

Pickles, J C; Hawkins, C; Pietsch, T; Jacques, T S

2018-02-01

Embryonal tumours of the central nervous system (CNS) present a significant clinical challenge. Many of these neoplasms affect young children, have a very high mortality and therapeutic strategies are often aggressive with poor long-term outcomes. There is a great need to accurately diagnose embryonal tumours, predict their outcome and adapt therapy to the individual patient's risk. For the first time in 2016, the WHO classification took into account molecular characteristics for the diagnosis of CNS tumours. This integration of histological features with genetic information has significantly changed the diagnostic work-up and reporting of tumours of the CNS. However, this remains challenging in embryonal tumours due to their previously unaccounted tumour heterogeneity. We describe the recent revisions made to the 4th edition of the WHO classification of CNS tumours and review the main changes, while highlighting some of the more common diagnostic testing strategies. © 2017 British Neuropathological Society.

Dealing with the Surgical and Medical Challenges of Penetrating Brain Injuries

PubMed Central

Syrmos, Nikolaos; Ganau, Mario; De Carlo, Antonella; Prisco, Lara; Ganau, Laura; Valadakis, Vasileios; Grigoriou, Kostantinos; Iliadis, Charalampos; Arvanitakis, Dimitrios

2013-01-01

Peacetime has reduced the overall incidence of penetrating brain injuries (PBI), and those related to missile penetration are not common anymore at least in western countries. Nevertheless, PBI still occur, and car crashes or work accidents are their main causes. The management of such cases is characterized by many challenges, not only from a surgical and medical point of view, but also for the different and sometimes bizarre dynamics by which they present. Herein we report an unusual deep penetrating brain injury, due to a high-energy crash against a metallic rod in a construction site, with a good surgical outcome despite dramatic clinical conditions on admission. A discussion of the surgical results and functional outcome related to PBI, as found in the English medical literature, is provided. Moreover the most common postoperative complications along with the diagnostic flow charts and therapeutic options useful to prevent inappropriate treatment are highlighted. PMID:23365777

Challenges to communicate risks of human-caused earthquakes

NASA Astrophysics Data System (ADS)

Klose, C. D.

2014-12-01

The awareness of natural hazards has been up-trending in recent years. In particular, this is true for earthquakes, which increase in frequency and magnitude in regions that normally do not experience seismic activity. In fact, one of the major concerns for many communities and businesses is that humans today seem to cause earthquakes due to large-scale shale gas production, dewatering and flooding of mines and deep geothermal power production. Accordingly, without opposing any of these technologies it should be a priority of earth scientists who are researching natural hazards to communicate earthquake risks. This presentation discusses the challenges that earth scientists are facing to properly communicate earthquake risks, in light of the fact that human-caused earthquakes are an environmental change affecting only some communities and businesses. Communication channels may range from research papers, books and class room lectures to outreach events and programs, popular media events or even social media networks.

Practical Methodology for the Inclusion of Nonlinear Slosh Damping in the Stability Analysis of Liquid-Propelled Space Vehicles

NASA Technical Reports Server (NTRS)

Ottander, John A.; Hall, Robert A.; Powers, Joseph F.

2017-01-01

One of the challenges of developing flight control systems for liquid-propelled space vehicles is ensuring stability and performance in the presence of parasitic minimally damped slosh dynamics in the liquid propellants. This can be especially difficult when the fundamental frequencies of the slosh motions are in proximity to the frequency used for vehicle control. The challenge is partially alleviated since the energy dissipation and effective damping in the slosh modes increases with amplitude. However, traditional launch vehicle control design methodology is performed with linearized systems using a fixed slosh damping corresponding to a slosh motion amplitude based on heritage values. This papers presents a method for performing the control design and analysis using damping at slosh amplitudes chosen based on the resulting limit cycle amplitude of the vehicle thrust vector system due to a control-slosh interaction under degraded phase and gain margin conditions.

Practical Methodology for the Inclusion of Nonlinear Slosh Damping in the Stability Analysis of Liquid-propelled Space Vehicles

NASA Technical Reports Server (NTRS)

Ottander, John A.; Hall, Robert A., Jr.; Powers, Joseph F.

2017-01-01

One of the challenges of developing flight control systems for liquid-propelled space vehicles is ensuring stability and performance in the presence of parasitic minimally damped slosh dynamics in the liquid propellants. This can be especially difficult when the fundamental frequencies of the slosh motions are in proximity to the frequency used for vehicle control. The challenge is partially alleviated since the energy dissipation and effective damping in the slosh modes increases with amplitude. However, traditional launch vehicle control design methodology is performed with linearized systems using a fixed slosh damping corresponding to a slosh motion amplitude based on heritage values. This papers presents a method for performing the control design and analysis using damping at slosh amplitudes chosen based on the resulting limit cycle amplitude of the vehicle thrust vector system due to a control-slosh interaction under degraded phase and gain margin conditions.

Development of Carbon Dioxide Removal Systems for Advanced Exploration Systems 2015-2016

NASA Technical Reports Server (NTRS)

Knox, James C.; Coker, Robert; Howard, David; Peters, Warren; Watson, David; Cmarik, Gregory; Miller, Lee A.

2016-01-01

A long-term goal for NASA is to enable crewed missions to Mars: first to the vicinity of Mars, and then to the Mars surface. These missions present new challenges for all aspects of spacecraft design in comparison with the International Space Station, as resupply is unavailable in the transit phase, and early return is not possible. Additionally, mass, power, and volume must be minimized for all phases to reduce propulsion needs. Mass reduction is particularly crucial for Mars surface landing and liftoff due to the challenges inherent in these operations for even much smaller payloads. In this paper we describe current and planned developments in the area of carbon dioxide removal to support future crewed Mars missions. Activities are also described that apply to both the resolution of anomalies observed in the ISS CDRA and the design of life support systems for future missions.

Atmospheric turbulence compensation in orbital angular momentum communications: Advances and perspectives

NASA Astrophysics Data System (ADS)

Li, Shuhui; Chen, Shi; Gao, Chunqing; Willner, Alan E.; Wang, Jian

2018-02-01

Orbital angular momentum (OAM)-carrying beams have recently generated considerable interest due to their potential use in communication systems to increase transmission capacity and spectral efficiency. For OAM-based free-space optical (FSO) links, a critical challenge is the atmospheric turbulence that will distort the helical wavefronts of OAM beams leading to the decrease of received power, introducing crosstalk between multiple channels, and impairing link performance. In this paper, we review recent advances in turbulence effects compensation techniques for OAM-based FSO communication links. First, basic concepts of atmospheric turbulence and theoretical model are introduced. Second, atmospheric turbulence effects on OAM beams are theoretically and experimentally investigated and discussed. Then, several typical turbulence compensation approaches, including both adaptive optics-based (optical domain) and signal processing-based (electrical domain) techniques, are presented. Finally, key challenges and perspectives of compensation of turbulence-distorted OAM links are discussed.

Facing technological challenges of Solar Updraft Power Plants

NASA Astrophysics Data System (ADS)

Lupi, F.; Borri, C.; Harte, R.; Krätzig, W. B.; Niemann, H.-J.

2015-01-01

The Solar Updraft Power Plant technology addresses a very challenging idea of combining two kinds of renewable energy: wind and solar. The working principle is simple: a Solar Updraft Power Plant (SUPP) consists of a collector area to heat the air due to the wide-banded ultra-violet solar radiation, the high-rise solar tower to updraft the heated air to the atmosphere, and in between the power conversion unit, where a system of coupled turbines and generators transforms the stream of heated air into electric power. A good efficiency of the power plant can only be reached with extra-large dimensions of the tower and/or the collector area. The paper presents an up-to-date review of the SUPP technology, focusing on the multi-physics modeling of the power plant, on the structural behavior of the tower and, last but not least, on the modeling of the stochastic wind loading process.

Biosensor-based microRNA detection: techniques, design, performance, and challenges.

PubMed

Johnson, Blake N; Mutharasan, Raj

2014-04-07

The current state of biosensor-based techniques for amplification-free microRNA (miRNA) detection is critically reviewed. Comparison with non-sensor and amplification-based molecular techniques (MTs), such as polymerase-based methods, is made in terms of transduction mechanism, associated protocol, and sensitivity. Challenges associated with miRNA hybridization thermodynamics which affect assay selectivity and amplification bias are briefly discussed. Electrochemical, electromechanical, and optical classes of miRNA biosensors are reviewed in terms of transduction mechanism, limit of detection (LOD), time-to-results (TTR), multiplexing potential, and measurement robustness. Current trends suggest that biosensor-based techniques (BTs) for miRNA assay will complement MTs due to the advantages of amplification-free detection, LOD being femtomolar (fM)-attomolar (aM), short TTR, multiplexing capability, and minimal sample preparation requirement. Areas of future importance in miRNA BT development are presented which include focus on achieving high measurement confidence and multiplexing capabilities.

Development of Carbon Dioxide Removal Systems for Advanced Exploration Systems 2014-2015

NASA Technical Reports Server (NTRS)

Knox, James C.; Coker, Robert; Huff, Timothy L.; Gatens, Robyn; Miller, Lee A.; Stanley, Christine

2015-01-01

A long-term goal for NASA is to enable crewed missions to Mars: first to the vicinity of Mars, and then to the Mars surface. These missions present new challenges for all aspects of spacecraft design in comparison with the International Space Station, as resupply is unavailable in the transit phase, and early return is not possible. Additionally, mass, power, and volume must be minimized for all phases to reduce propulsion needs. Mass reduction is particularly crucial for Mars surface landing and liftoff due to the challenges inherent in these operations for even much smaller payloads. In this paper we describe current and planned developments in the area of carbon dioxide removal to support future crewed Mars missions. Activities are also described that apply to both the resolution of anomalies observed in the ISS CDRA and the design of life support systems for future missions.

Mid-infrared Laser Absorption Diagnostics for Detonation Studies

NASA Astrophysics Data System (ADS)

Spearrin, R. M.; Goldenstein, C. S.; Jeffries, J. B.; Hanson, R. K.

Detonation-based engines represent a challenging application for diagnostics due to the wide range of thermodynamic conditions involved (T~500-3000 K, P~2-60 atm) and the short time scales of change (~10- 6 to 10- 4 sec) associated with such systems. Non-intrusive laser absorption diagnostics can provide high time-resolution and have been employed extensively in shock tube kinetics experiments (P~1-20 atm), offering high potential for application in detonation environments with modest utilization to date [1-4]. Limiting factors in designing effective tunable laser absorption sensors for detonation engines can be divided into two sets of challenges: high-pressure, high-temperature absorption spectroscopy and harsh thermo-mechanical environments. The present work, conducted in a high-pressure shock tube and operating detonation combustor, addresses both sets of difficulties, with the objective of developing time-resolved, in-situ temperature and concentration sensors for detonation studies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barstow, Del R; Patlolla, Dilip Reddy; Mann, Christopher J

Abstract The data captured by existing standoff biometric systems typically has lower biometric recognition performance than their close range counterparts due to imaging challenges, pose challenges, and other factors. To assist in overcoming these limitations systems typically perform in a multi-modal capacity such as Honeywell s Combined Face and Iris (CFAIRS) [21] system. While this improves the systems performance, standoff systems have yet to be proven as accurate as their close range equivalents. We will present a standoff system capable of operating up to 7 meters in range. Unlike many systems such as the CFAIRS our system captures high qualitymore » 12 MP video allowing for a multi-sample as well as multi-modal comparison. We found that for standoff systems multi-sample improved performance more than multi-modal. For a small test group of 50 subjects we were able to achieve 100% rank one recognition performance with our system.« less