Sir Nicholas Harold Lloyd Ridley: 10 July 1906 - 25 May 2001.

PubMed

Apple, David J

2007-01-01

Sir Harold Ridley invented and refined the modern miracle of replacing lenses obscured by cataracts with plastic optical lenses, thus rendering a complete cataract cure. This operation, broadly termed the cataract-intraocular lens (IOL) operation, has since brought sight to many millions of people throughout the world, and continues to improve the quality of life of more than 10 million patients worldwide each year. Ridley not only launched this powerful and irreversible forward movement in the field of ophthalmology and the visual sciences, but through it he also helped give birth to the exciting and new field of artificial biodevice implantation as well as transplantation techniques now applied to many other organs and tissues of the body. He has therefore been credited with healing to create the relatively new specialty of biomedical engineering. Few of the millions of patients worldwide who now enjoy the benefits of the modern cataract - IOL operation are aware of the origin of this innovation. Indeed, few eye care professionals - even ophthalmic surgeons who implant them almost daily - are aware of the origin of the IOL - an invention that, as Harold himself liked to say, 'cured aphakia'. (The word aphakia comes from teh Greek, meaning absence of lens, the situation that occurs when a cataractous lens is surgically removed.)

PCBS AND OTHER CHLORINATED ORGANIC CONTAMINANTS IN TISSUES OF JUVENILE KEMP'S RIDLEY TURTLES (LEPIDOCHELYS KEMPI)

EPA Science Inventory

Concentrations of PCBs (polychlorinated biphenyls) and chlorinated pesticides were measured in liver and body fat samples of juvenile Kemp's ridley sea turtles (Lepidochelys kempi). hese turtles were killed in the fall or early winter by rapid seasonal temperature drops and were ...

Metabolic and respiratory status of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii).

PubMed

Innis, Charles J; Tlusty, Michael; Merigo, Constance; Weber, E Scott

2007-08-01

"Cold-stunning" of sea turtles has been reported as a naturally occurring stressor for many years; however, the physiologic status of cold-stunned turtles has only been partially described. This study investigated initial and convalescent venous blood gas, acid-base, and critical plasma biochemical data for 26 naturally cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) from Cape Cod, MA, USA. Samples were analyzed for pH, pCO(2), pO(2), bicarbonate, plasma osmolality, sodium, potassium, chloride, ionized calcium, ionized magnesium, glucose, lactate, and blood urea nitrogen using a clinical point-of-care analyzer. Data were corrected for the patient's body temperature using both species-specific and more general correction methods. In general, venous blood gas, acid-base, and plasma biochemical data obtained for surviving cold-stunned Kemp's ridley sea turtles were consistent with previously documented data for sea turtles exposed to a wide range of temperatures and physiologic stressors. Data indicated that turtles were initially affected by metabolic and respiratory acidosis. Initial pH-corrected ionized calcium concentrations were lower than convalescent concentrations, and initial pH-corrected ionized magnesium concentrations were higher than convalescent concentrations.

Isolation by environment in the highly mobile olive ridley turtle (Lepidochelys olivacea) in the eastern Pacific.

PubMed

Rodríguez-Zárate, Clara J; Sandoval-Castillo, Jonathan; van Sebille, Erik; Keane, Robert G; Rocha-Olivares, Axayácatl; Urteaga, Jose; Beheregaray, Luciano B

2018-05-16

Spatial and temporal scales at which processes modulate genetic diversity over the landscape are usually overlooked, impacting the design of conservation management practices for widely distributed species. We examine processes shaping population divergence in highly mobile species by re-assessing the case of panmixia in the iconic olive ridley turtle from the eastern Pacific. We implemented a biophysical model of connectivity and a seascape genetic analysis based on nuclear DNA variation of 634 samples collected from 27 nesting areas. Two genetically distinct populations largely isolated during reproductive migrations and mating were detected, each composed of multiple nesting sites linked by high connectivity. This pattern was strongly associated with a steep environmental gradient and also influenced by ocean currents. These findings relate to meso-scale features of a dynamic oceanographic interface in the eastern tropical Pacific (ETP) region, a scenario that possibly provides different cost-benefit solutions and selective pressures for sea turtles during both the mating and migration periods. We reject panmixia and propose a new paradigm for olive ridley turtles where reproductive isolation due to assortative mating is linked to its environment. Our study demonstrates the relevance of integrative approaches for assessing the role of environmental gradients and oceanographic currents as drivers of genetic differentiation in widely distributed marine species. This is relevant for the conservation management of species of highly mobile behaviour, and assists the planning and development of large-scale conservation strategies for the threatened olive ridley turtles in the ETP. © 2018 The Author(s).

Assessment of ground transportation stress in juvenile Kemp's ridley sea turtles (Lepidochelys kempii).

PubMed

Hunt, Kathleen E; Innis, Charles J; Kennedy, Adam E; McNally, Kerry L; Davis, Deborah G; Burgess, Elizabeth A; Merigo, Constance

2016-01-01

Sea turtle rehabilitation centres frequently transport sea turtles for long distances to move animals between centres or to release them at beaches, yet there is little information on the possible effects of transportation-related stress ('transport stress') on sea turtles. To assess whether transport stress is a clinically relevant concern for endangered Kemp's ridley sea turtles (Lepidochelys kempii), we obtained pre-transport and post-transport plasma samples from 26 juvenile Kemp's ridley sea turtles that were transported for 13 h (n = 15 turtles) or 26 h (n = 11 turtles) by truck for release at beaches. To control for effects of handling, food restriction and time of day, the same turtles were also studied on 'control days' 2 weeks prior to transport, i.e. with two samples taken to mimic pre-transport and post-transport timing, but without transportation. Blood samples were analysed for nine clinical health measures (pH, pCO2, pO2, HCO3, sodium, potassium, ionized calcium, lactate and haematocrit) and four 'stress-associated' parameters (corticosterone, glucose, white blood cell count and heterophil-to-lymphocyte ratio). Vital signs (heart rate, respiratory rate and cloacal temperature) were also monitored. Corticosterone and glucose showed pronounced elevations due specifically to transportation; for corticosterone, this elevation was significant only for the longer transport duration, whereas glucose increased significantly after both transport durations. However, clinical health measures and vital signs showed minimal or no changes in response to any sampling event (with or without transport), and all turtles appeared to be in good clinical health after both transport durations. Thus, transportation elicits a mild, but detectable, adrenal stress response that is more pronounced during longer durations of transport; nonetheless, Kemp's ridley sea turtles can tolerate ground transportation of up to 26 h in good health. These results are likely

Assessment of ground transportation stress in juvenile Kemp’s ridley sea turtles (Lepidochelys kempii)

PubMed Central

Hunt, Kathleen E.; Innis, Charles J.; Kennedy, Adam E.; McNally, Kerry L.; Davis, Deborah G.; Burgess, Elizabeth A.; Merigo, Constance

2016-01-01

Sea turtle rehabilitation centres frequently transport sea turtles for long distances to move animals between centres or to release them at beaches, yet there is little information on the possible effects of transportation-related stress (‘transport stress’) on sea turtles. To assess whether transport stress is a clinically relevant concern for endangered Kemp’s ridley sea turtles (Lepidochelys kempii), we obtained pre-transport and post-transport plasma samples from 26 juvenile Kemp’s ridley sea turtles that were transported for 13 h (n = 15 turtles) or 26 h (n = 11 turtles) by truck for release at beaches. To control for effects of handling, food restriction and time of day, the same turtles were also studied on ‘control days’ 2 weeks prior to transport, i.e. with two samples taken to mimic pre-transport and post-transport timing, but without transportation. Blood samples were analysed for nine clinical health measures (pH, pCO2, pO2, HCO3, sodium, potassium, ionized calcium, lactate and haematocrit) and four ‘stress-associated’ parameters (corticosterone, glucose, white blood cell count and heterophil-to-lymphocyte ratio). Vital signs (heart rate, respiratory rate and cloacal temperature) were also monitored. Corticosterone and glucose showed pronounced elevations due specifically to transportation; for corticosterone, this elevation was significant only for the longer transport duration, whereas glucose increased significantly after both transport durations. However, clinical health measures and vital signs showed minimal or no changes in response to any sampling event (with or without transport), and all turtles appeared to be in good clinical health after both transport durations. Thus, transportation elicits a mild, but detectable, adrenal stress response that is more pronounced during longer durations of transport; nonetheless, Kemp’s ridley sea turtles can tolerate ground transportation of up to 26 h in good health. These

Humoral Immune Responses to Select Marine Bacteria in Loggerhead Sea Turtles Caretta caretta and Kemp's Ridley Sea Turtles Lepidochelys kempii from the Southeastern United States.

PubMed

Rodgers, Maria L; Toline, Catherine A; Rice, Charles D

2018-03-01

Serum from Kemp's ridley sea turtles Lepidochelys kempii and loggerhead sea turtles Caretta caretta was collected during summer in 2011, 2012, and 2013. Serum immunoglobulin Y (IgY) recognition of lysate proteins from nine bacterial species and whole bacterium-specific IgY titers to these pathogens were quantified. Serum and purified IgY recognized proteins of all bacteria, with protein recognition for some species being more pronounced than others. Circulating IgY titers against Vibrio vulnificus, V. anguillarum, Erysipelothrix rhusiopathiae, and Brevundimonas vesicularis changed over the years in Kemp's ridley sea turtles, while IgY titers against V. vulnificus, Escherichia coli, V. parahaemolyticus, B. vesicularis, and Mycobacterium marinum were different in loggerhead sea turtles. Serum lysozyme activity was constant for loggerhead sea turtles over the 3 years, while activity in Kemp's ridley sea turtles was lower in 2011 and 2012 than in 2013. Blood packed cell volume, glucose, and serum protein levels were comparable to those of healthy sea turtles in previous studies; therefore, this study provides baseline information on antibody responses in healthy wild sea turtles. © 2017 American Fisheries Society.

The Impact of Turtle Excluder Devices and Fisheries Closures on Loggerhead and Kemp's Ridley Strandings in the Western Gulf of Mexico

USGS Publications Warehouse

Lewison, R.L.; Crowder, L.B.; Shaver, D.J.

2003-01-01

The Sea Turtle Stranding and Salvage Network has been monitoring turtle strandings for more than 20 years in the United States. High numbers of strandings in the early to mid-1980s prompted regulations to require turtle excluder devices (TEDs) on shrimping vessels (trawlers). Following year-round TED implementation in 1991, however, stranding levels in the Gulf of Mexico increased. We evaluated the efficacy of TEDs and other management actions (e.g., fisheries closures) on loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) turtle populations by analyzing a long-term, stranding data set from the western Gulf of Mexico. Our analyses suggest that both sea turtle population growth and shrimping activity have contributed to the observed increase in strandings. Compliance with regulations requiring turtle excluder devices was a significant factor in accounting for annual stranding variability: low compliance was correlated with high levels of strandings. Our projections suggest that improved compliance with TED regulations will reduce strandings to levels that, in conjunction with other protective measures, should promote population recoveries for loggerhead and Kemp's ridley turtles. Local, seasonal fisheries closures, concurrent with TED enforcement, could reduce strandings to even lower levels. A seasonal closure adjacent to a recently established Kemp's ridley nesting beach may also reduce mortality of nesting adults and thus promote long-term population persistence by fostering the establishment of a robust secondary nesting site.

The use of spirometry to evaluate pulmonary function in olive ridley sea turtles (Lepidochelys olivacea) with positive buoyancy disorders.

PubMed

Schmitt, Todd L; Munns, Suzanne; Adams, Lance; Hicks, James

2013-09-01

This study utilized computed spirometry to compare the pulmonary function of two stranded olive ridley sea turtles (Lepidochelys olivacea) presenting with a positive buoyancy disorder with two healthy captive olive ridley sea turtles held in a large public aquarium. Pulmonary function test (PFT) measurements demonstrated that the metabolic cost of breathing was much greater for animals admitted with positive buoyancy than for the normal sea turtles. Positively buoyant turtles had higher tidal volumes and significantly lower breathing-frequency patterns with significantly higher expiration rates, typical of gasp-type breathing. The resulting higher energetic cost of breathing in the diseased turtles may have a significant impact on their long-term survival. The findings represent a method for clinical respiratory function analysis for an individual animal to assist with diagnosis, therapy, and prognosis. This is the first study, to our knowledge, to evaluate objectively sea turtles presenting with positive buoyancy and respiratory disease using pulmonary function tests.

The influence of oceanographic features on the foraging behavior of the olive ridley sea turtle Lepidochelys olivacea along the Guiana coast

NASA Astrophysics Data System (ADS)

Chambault, Philippine; de Thoisy, Benoît; Heerah, Karine; Conchon, Anna; Barrioz, Sébastien; Dos Reis, Virginie; Berzins, Rachel; Kelle, Laurent; Picard, Baptiste; Roquet, Fabien; Le Maho, Yvon; Chevallier, Damien

2016-03-01

The circulation in the Western Equatorial Atlantic is characterized by a highly dynamic mesoscale activity that shapes the Guiana continental shelf. Olive ridley sea turtles (Lepidochelys olivacea) nesting in French Guiana cross this turbulent environment during their post-nesting migration. We studied how oceanographic and biological conditions drove the foraging behavior of 18 adult females, using satellite telemetry, remote sensing data (sea surface temperature, sea surface height, current velocity and euphotic depth), simulations of micronekton biomass (pelagic organisms) and in situ records (water temperature and salinity). The occurrence of foraging events throughout migration was located using Residence Time analysis, while an innovative proxy of the hunting time within a dive was used to identify and quantify foraging events during dives. Olive ridleys migrated northwestwards using the Guiana current and remained on the continental shelf at the edge of eddies formed by the North Brazil retroflection, an area characterized by low turbulence and high micronekton biomass. They performed mainly pelagic dives, hunting for an average 77% of their time. Hunting time within a dive increased with shallower euphotic depth and with lower water temperatures, and mean hunting depth increased with deeper thermocline. This is the first study to quantify foraging activity within dives in olive ridleys, and reveals the crucial role played by the thermocline on the foraging behavior of this carnivorous species. This study also provides novel and detailed data describing how turtles actively use oceanographic structures during post-nesting migration.

Using Satellite Tracking to Optimize Protection of Long-Lived Marine Species: Olive Ridley Sea Turtle Conservation in Central Africa

PubMed Central

Maxwell, Sara M.; Breed, Greg A.; Nickel, Barry A.; Makanga-Bahouna, Junior; Pemo-Makaya, Edgard; Parnell, Richard J.; Formia, Angela; Ngouessono, Solange; Godley, Brendan J.; Costa, Daniel P.; Witt, Matthew J.; Coyne, Michael S.

2011-01-01

Tractable conservation measures for long-lived species require the intersection between protection of biologically relevant life history stages and a socioeconomically feasible setting. To protect breeding adults, we require knowledge of animal movements, how movement relates to political boundaries, and our confidence in spatial analyses of movement. We used satellite tracking and a switching state-space model to determine the internesting movements of olive ridley sea turtles (Lepidochelys olivacea) (n = 18) in Central Africa during two breeding seasons (2007-08, 2008-09). These movements were analyzed in relation to current park boundaries and a proposed transboundary park between Gabon and the Republic of Congo, both created to reduce unintentional bycatch of sea turtles in marine fisheries. We additionally determined confidence intervals surrounding home range calculations. Turtles remained largely within a 30 km radius from the original nesting site before departing for distant foraging grounds. Only 44.6 percent of high-density areas were found within the current park but the proposed transboundary park would incorporate 97.6 percent of high-density areas. Though tagged individuals originated in Gabon, turtles were found in Congolese waters during greater than half of the internesting period (53.7 percent), highlighting the need for international cooperation and offering scientific support for a proposed transboundary park. This is the first comprehensive study on the internesting movements of solitary nesting olive ridley sea turtles, and it suggests the opportunity for tractable conservation measures for female nesting olive ridleys at this and other solitary nesting sites around the world. We draw from our results a framework for cost-effective protection of long-lived species using satellite telemetry as a primary tool. PMID:21589942

Potential effects of brevetoxins and toxic elements on various health variables in Kemp's ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles after a red tide bloom event.

PubMed

Perrault, Justin R; Stacy, Nicole I; Lehner, Andreas F; Mott, Cody R; Hirsch, Sarah; Gorham, Jonathan C; Buchweitz, John P; Bresette, Michael J; Walsh, Catherine J

2017-12-15

Natural biotoxins and anthropogenic toxicants pose a significant risk to sea turtle health. Documented effects of contaminants include potential disease progression and adverse impacts on development, immune function, and survival in these imperiled species. The shallow seagrass habitats of Florida's northwest coast (Big Bend) serve as an important developmental habitat for Kemp's ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles; however, few studies have been conducted in this area. Our objectives were (1) to evaluate plasma analytes (mass, minimum straight carapace length, body condition index [BCI], fibropapilloma tumor score, lysozyme, superoxide dismutase, reactive oxygen/nitrogen species, plasma protein electrophoresis, cholesterol, and total solids) in Kemp's ridleys and green turtles and their correlation to brevetoxins that were released from a red tide bloom event from July-October 2014 in the Gulf of Mexico near Florida's Big Bend, and (2) to analyze red blood cells in Kemp's ridleys and green turtles for toxic elements (arsenic, cadmium, lead, mercury, selenium, thallium) with correlation to the measured plasma analytes. Positive correlations were observed between brevetoxins and α 2 -globulins in Kemp's ridleys and α 2 - and γ-globulins in green turtles, indicating potential immunostimulation. Arsenic, cadmium, and lead positively correlated with superoxide dismutase in Kemp's ridleys, suggesting oxidative stress. Lead and mercury in green turtles negatively correlated with BCI, while mercury positively correlated with total tumor score of green turtles afflicted with fibropapillomatosis, suggesting a possible association with mercury and increased tumor growth. The total tumor score of green turtles positively correlated with total protein, total globulins, α 2 -globulins, and γ-globulins, further suggesting inflammation and immunomodulation as a result of fibropapillomatosis. Lastly, brevetoxin concentrations were positively

47 CFR 80.359 - Frequencies for digital selective calling (DSC).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Frequencies for digital selective calling (DSC... for digital selective calling (DSC). (a) General purpose calling. The following table describes the calling frequencies for use by authorized ship and coast stations for general purpose DSC. There are three...

Prevalence, distribution, and progression of radiographic abnormalities in the lungs of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii): 89 cases (2002-2005).

PubMed

Stockman, Jonathan; Innis, Charles J; Solano, Mauricio; O'Sullivan Brisson, Jennifer; Kass, Philip H; Tlusty, Michael F; Weber, E Scott

2013-03-01

To evaluate the prevalence, distribution, and progression of radiographic abnormalities in the lungs of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) and associations between these abnormalities and body weight, carapace length, and hematologic and plasma biochemical variables. Retrospective case series. 89 cold-stunned juvenile Kemp's ridley sea turtles. Medical records were reviewed. Dorsoventral and horizontal beam craniocaudal radiographs were evaluated for the presence, distribution, and progression of lung abnormalities. Turtles were categorized as having radiographically normal or abnormal lungs; those with abnormalities detected were further categorized according to the distribution of abnormalities (left lung, right lung, or both affected). Body weight, carapace length, and hematologic and plasma biochemical data were compared among categories. 48 of 89 (54%) turtles had radiographic abnormalities of the lungs. Unilateral abnormalities of the right or left lung were detected in 14 (16%) and 2 (2%), respectively; both lungs were affected in 32 (36%). Prevalence of unilateral abnormalities was significantly greater for the right lung than for the left lung. Evaluation of follow-up radiographs indicated clinical improvement over time for most (18/31 [58%]) turtles. Prevalence of bilateral radiographic abnormalities was positively correlated with body weight and carapace length. There was no significant association between radiographic category and hematologic or plasma biochemical variables. Radiographic abnormalities of the lungs were commonly detected in cold-stunned Kemp's ridley turtles. Results of this study may aid clinicians in developing effective diagnostic and treatment plans for these patients.

Design and long-term monitoring of DSC/CIGS tandem solar module

NASA Astrophysics Data System (ADS)

Vildanova, M. F.; Nikolskaia, A. B.; Kozlov, S. S.; Shevaleevskiy, O. I.

2015-11-01

This paper describes the design and development of tandem dye-sensitized/Cu(In, Ga)Se (DSC/CIGS) PV modules. The tandem PV module comprised of the top DSC module and a bottom commercial 0,8 m2 CIGS module. The top DSC module was made of 10 DSC mini-modules with the field size of 20 × 20 cm2 each. Tandem DSC/CIGS PV modules were used for providing the long-term monitoring of energy yield and electrical parameters in comparison with standalone CIGS modules under outdoor conditions. The outdoor test facility, containing solar modules of both types and a measurement unit, was located on the roof of the Institute of Biochemical Physics in Moscow. The data obtained during monitoring within the 2014 year period has shown the advantages of the designed tandem DSC/CIGS PV-modules over the conventional CIGS modules, especially for cloudy weather and low-intensity irradiation conditions.

Corticosterone and thyroxine in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii).

PubMed

Hunt, Kathleen E; Innis, Charles; Rolland, Rosalind M

2012-09-01

Kemp's ridley sea turtles (Lepidochelys kempii), a critically endangered species, frequently strand on the shores of Cape Cod (Massachusetts, USA) in late autumn in a state of "cold-stunning" exhibiting low body temperature and related clinical issues. Stranded turtles are transported to the New England Aquarium (Boston, Massachusetts, USA) for treatment and rehabilitation. This study tested the hypothesis that cold-stunned sea turtles might exhibit high corticosterone ("stress hormone") or low thyroxine (which is often affected by temperature), or both, and that monitoring of both hormones may be useful for assessing recovery. In a retrospective analysis, 87 archived plasma samples were assayed from 56 cold-stunned juvenile Kemp's ridley sea turtles for corticosterone and free thyroxine (fT4). Upon admission, mean corticosterone was the highest yet reported for a population of sea turtles (39.3 +/- 2.5 ng/ml; mean +/- standard error of the mean [SEM]) and fT4 was usually undetectable. On admission, corticosterone was negatively correlated with white blood cell count but was not correlated with blood glucose. There were no differences in either hormone between survivors and nonsurvivors on admission. After 18+ days in recovery, surviving turtles' corticosterone dropped significantly to levels typical of baseline in other species (0.9 +/- 1.0 ng/ml) while fT4 increased significantly (1.3 +/- 1.5 pg/ml). During recovery, corticosterone was positively correlated with blood glucose and was not correlated with white blood cell count. Turtles that showed persistent deficits in feeding, activity, or both during recovery had significantly lower fT4 than did turtles with no such deficits. The "high corticosterone, low fT4" endocrine profile seen on admission may be a useful marker of cold-stunning in this and other species. Further studies are necessary to determine whether low thyroid hormones play a causal role in deficits in feeding and activity during recovery

Pahangensin A and B, two new antibacterial diterpenes from the rhizomes of Alpinia pahangensis Ridley.

PubMed

Sivasothy, Yasodha; Ibrahim, Halijah; Paliany, Audra Shaleena; Alias, Siti Aisyah; Awang, Khalijah

2013-12-01

The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus. Copyright © 2013 Elsevier Ltd. All rights reserved.

Variability in age and size at maturation, reproductive longevity, and long-term growth dynamics for Kemp's ridley sea turtles in the Gulf of Mexico.

PubMed

Avens, Larisa; Goshe, Lisa R; Coggins, Lewis; Shaver, Donna J; Higgins, Ben; Landry, Andre M; Bailey, Rhonda

2017-01-01

Effective management of protected sea turtle populations requires knowledge not only of mean values for demographic and life-history parameters, but also temporal and spatial trends, variability, and underlying causes. For endangered Kemp's ridley sea turtles (Lepidochelys kempii), the need for baseline information of this type has been emphasized during attempts to understand causes underlying the recent truncation in the recovery trajectory for nesting females. To provide insight into variability in age and size at sexual maturation (ASM and SSM) and long-term growth patterns likely to influence population trends, we conducted skeletochronological analysis of humerus bones from 333 Kemp's ridleys stranded throughout the Gulf of Mexico (GOM) from 1993 to 2010. Ranges of possible ASMs (6.8 to 21.8 yr) and SSMs (53.3 to 68.3 cm straightline carapace length (SCL)) estimated using the "rapprochement" skeletal growth mark associated with maturation were broad, supporting incorporation of a maturation schedule in Kemp's ridley population models. Mean ASMs estimated from rapprochement and by fitting logistic, generalized additive mixed, and von Bertalanffy growth models to age and growth data ranged from 11 to 13 yr; confidence intervals for the logistic model predicted maturation of 95% of the population between 11.9 and 14.8 yr. Early juvenile somatic growth rates in the GOM were greater than those previously reported for the Atlantic, indicating potential for differences in maturation trajectories between regions. Finally, long-term, significant decreases in somatic growth response were found for both juveniles and adults, which could influence recruitment to the reproductive population and observed nesting population trends.

Peer-Reviewed Research and the IEP: Implications of "Ridley School District v. M.R. and J.R. ex rel. E.R." (2012)

ERIC Educational Resources Information Center

Yell, Mitchell L.; Katsiyannis, Antonis; Losinski, Mickey; Marshall, Kelsey

2016-01-01

This article examines a case out of the U.S. Court of Appeals for the Third Circuit: "Ridley School District v. M.R and J.R. ex rel. E.R." (2012). The case is the first circuit court case in which the Individuals with Disabilities Education Improvement Act requirement that special education services be based on peer-reviewed research…

Variability in age and size at maturation, reproductive longevity, and long-term growth dynamics for Kemp's ridley sea turtles in the Gulf of Mexico

PubMed Central

Goshe, Lisa R.; Coggins, Lewis; Shaver, Donna J.; Higgins, Ben; Landry, Andre M.; Bailey, Rhonda

2017-01-01

Effective management of protected sea turtle populations requires knowledge not only of mean values for demographic and life-history parameters, but also temporal and spatial trends, variability, and underlying causes. For endangered Kemp’s ridley sea turtles (Lepidochelys kempii), the need for baseline information of this type has been emphasized during attempts to understand causes underlying the recent truncation in the recovery trajectory for nesting females. To provide insight into variability in age and size at sexual maturation (ASM and SSM) and long-term growth patterns likely to influence population trends, we conducted skeletochronological analysis of humerus bones from 333 Kemp’s ridleys stranded throughout the Gulf of Mexico (GOM) from 1993 to 2010. Ranges of possible ASMs (6.8 to 21.8 yr) and SSMs (53.3 to 68.3 cm straightline carapace length (SCL)) estimated using the “rapprochement” skeletal growth mark associated with maturation were broad, supporting incorporation of a maturation schedule in Kemp’s ridley population models. Mean ASMs estimated from rapprochement and by fitting logistic, generalized additive mixed, and von Bertalanffy growth models to age and growth data ranged from 11 to 13 yr; confidence intervals for the logistic model predicted maturation of 95% of the population between 11.9 and 14.8 yr. Early juvenile somatic growth rates in the GOM were greater than those previously reported for the Atlantic, indicating potential for differences in maturation trajectories between regions. Finally, long-term, significant decreases in somatic growth response were found for both juveniles and adults, which could influence recruitment to the reproductive population and observed nesting population trends. PMID:28333937

47 CFR 80.359 - Frequencies for digital selective calling (DSC).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequencies for digital selective calling (DSC... for digital selective calling (DSC). (a) General purpose calling. The following table describes the... Digital Selective-Calling Equipment in the Maritime Mobile Service,” with Annexes 1 through 5, 2004, and...

7 CFR 1710.114 - TIER, DSC, OTIER and ODSC requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 11 2011-01-01 2011-01-01 false TIER, DSC, OTIER and ODSC requirements. 1710.114... AND GUARANTEES Loan Purposes and Basic Policies § 1710.114 TIER, DSC, OTIER and ODSC requirements. (a) General. Requirements for coverage ratios are set forth in the borrower's mortgage, loan contract, or...

Effect of milling on DSC thermogram of excipient adipic acid.

PubMed

Ng, Wai Kiong; Kwek, Jin Wang; Yuen, Aaron; Tan, Chin Lee; Tan, Reginald

2010-03-01

The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential scanning calorimetry (DSC) measured fusion enthalpy (Delta(fus)H) and melting point (T(m)) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after milling, the values of Delta(fus)H and T(m) were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results.

Multispectral Image Compression Based on DSC Combined with CCSDS-IDC

PubMed Central

Li, Jin; Xing, Fei; Sun, Ting; You, Zheng

2014-01-01

Remote sensing multispectral image compression encoder requires low complexity, high robust, and high performance because it usually works on the satellite where the resources, such as power, memory, and processing capacity, are limited. For multispectral images, the compression algorithms based on 3D transform (like 3D DWT, 3D DCT) are too complex to be implemented in space mission. In this paper, we proposed a compression algorithm based on distributed source coding (DSC) combined with image data compression (IDC) approach recommended by CCSDS for multispectral images, which has low complexity, high robust, and high performance. First, each band is sparsely represented by DWT to obtain wavelet coefficients. Then, the wavelet coefficients are encoded by bit plane encoder (BPE). Finally, the BPE is merged to the DSC strategy of Slepian-Wolf (SW) based on QC-LDPC by deep coupling way to remove the residual redundancy between the adjacent bands. A series of multispectral images is used to test our algorithm. Experimental results show that the proposed DSC combined with the CCSDS-IDC (DSC-CCSDS)-based algorithm has better compression performance than the traditional compression approaches. PMID:25110741

Multispectral image compression based on DSC combined with CCSDS-IDC.

PubMed

Li, Jin; Xing, Fei; Sun, Ting; You, Zheng

2014-01-01

Remote sensing multispectral image compression encoder requires low complexity, high robust, and high performance because it usually works on the satellite where the resources, such as power, memory, and processing capacity, are limited. For multispectral images, the compression algorithms based on 3D transform (like 3D DWT, 3D DCT) are too complex to be implemented in space mission. In this paper, we proposed a compression algorithm based on distributed source coding (DSC) combined with image data compression (IDC) approach recommended by CCSDS for multispectral images, which has low complexity, high robust, and high performance. First, each band is sparsely represented by DWT to obtain wavelet coefficients. Then, the wavelet coefficients are encoded by bit plane encoder (BPE). Finally, the BPE is merged to the DSC strategy of Slepian-Wolf (SW) based on QC-LDPC by deep coupling way to remove the residual redundancy between the adjacent bands. A series of multispectral images is used to test our algorithm. Experimental results show that the proposed DSC combined with the CCSDS-IDC (DSC-CCSDS)-based algorithm has better compression performance than the traditional compression approaches.

Inter-nesting movements and habitat-use of adult female Kemp's ridley turtles in the Gulf of Mexico.

PubMed

Shaver, Donna J; Hart, Kristen M; Fujisaki, Ikuko; Bucklin, David; Iverson, Autumn R; Rubio, Cynthia; Backof, Thomas F; Burchfield, Patrick M; de Jesus Gonzales Diaz Miron, Raul; Dutton, Peter H; Frey, Amy; Peña, Jaime; Gomez Gamez, Daniel; Martinez, Hector J; Ortiz, Jaime

2017-01-01

Species vulnerability is increased when individuals congregate in restricted areas for breeding; yet, breeding habitats are not well defined for many marine species. Identification and quantification of these breeding habitats are essential to effective conservation. Satellite telemetry and switching state-space modeling (SSM) were used to define inter-nesting habitat of endangered Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. Turtles were outfitted with satellite transmitters after nesting at Padre Island National Seashore, Texas, USA, from 1998 through 2013 (n = 60); Rancho Nuevo, Tamaulipas, Mexico, during 2010 and 2011 (n = 11); and Tecolutla, Veracruz, Mexico, during 2012 and 2013 (n = 11). These sites span the range of nearly all nesting by this species. Inter-nesting habitat lies in a narrow band of nearshore western Gulf of Mexico waters in the USA and Mexico, with mean water depth of 14 to 19 m within a mean distance to shore of 6 to 11 km as estimated by 50% kernel density estimate, α-Hull, and minimum convex polygon methodologies. Turtles tracked during the inter-nesting period moved, on average, 17.5 km/day and a mean total distance of 398 km. Mean home ranges occupied were 725 to 2948 km2. Our results indicate that these nearshore western Gulf waters represent critical inter-nesting habitat for this species, where threats such as shrimp trawling and oil and gas platforms also occur. Up to half of all adult female Kemp's ridleys occupy this habitat for weeks to months during each nesting season. Because inter-nesting habitat for this species is concentrated in nearshore waters of the western Gulf of Mexico in both Mexico and the USA, international collaboration is needed to protect this essential habitat and the turtles occurring within it.

Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization

NASA Astrophysics Data System (ADS)

Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

2016-06-01

A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites.

Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization

PubMed Central

Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

2016-01-01

A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites. PMID:27319782

D-DSC: Decoding Delay-based Distributed Source Coding for Internet of Sensing Things

PubMed Central

Akan, Ozgur B.

2018-01-01

Spatial correlation between densely deployed sensor nodes in a wireless sensor network (WSN) can be exploited to reduce the power consumption through a proper source coding mechanism such as distributed source coding (DSC). In this paper, we propose the Decoding Delay-based Distributed Source Coding (D-DSC) to improve the energy efficiency of the classical DSC by employing the decoding delay concept which enables the use of the maximum correlated portion of sensor samples during the event estimation. In D-DSC, network is partitioned into clusters, where the clusterheads communicate their uncompressed samples carrying the side information, and the cluster members send their compressed samples. Sink performs joint decoding of the compressed and uncompressed samples and then reconstructs the event signal using the decoded sensor readings. Based on the observed degree of the correlation among sensor samples, the sink dynamically updates and broadcasts the varying compression rates back to the sensor nodes. Simulation results for the performance evaluation reveal that D-DSC can achieve reliable and energy-efficient event communication and estimation for practical signal detection/estimation applications having massive number of sensors towards the realization of Internet of Sensing Things (IoST). PMID:29538405

D-DSC: Decoding Delay-based Distributed Source Coding for Internet of Sensing Things.

PubMed

Aktas, Metin; Kuscu, Murat; Dinc, Ergin; Akan, Ozgur B

2018-01-01

Spatial correlation between densely deployed sensor nodes in a wireless sensor network (WSN) can be exploited to reduce the power consumption through a proper source coding mechanism such as distributed source coding (DSC). In this paper, we propose the Decoding Delay-based Distributed Source Coding (D-DSC) to improve the energy efficiency of the classical DSC by employing the decoding delay concept which enables the use of the maximum correlated portion of sensor samples during the event estimation. In D-DSC, network is partitioned into clusters, where the clusterheads communicate their uncompressed samples carrying the side information, and the cluster members send their compressed samples. Sink performs joint decoding of the compressed and uncompressed samples and then reconstructs the event signal using the decoded sensor readings. Based on the observed degree of the correlation among sensor samples, the sink dynamically updates and broadcasts the varying compression rates back to the sensor nodes. Simulation results for the performance evaluation reveal that D-DSC can achieve reliable and energy-efficient event communication and estimation for practical signal detection/estimation applications having massive number of sensors towards the realization of Internet of Sensing Things (IoST).

Gelatinisation kinetics of corn and chickpea starches using DSC, RVA, and dynamic rheometry

USDA-ARS?s Scientific Manuscript database

The gelatinisation kinetics (non-isothermal) of corn and chickpea starches at different heating rates were calculated using differential scanning calorimetry (DSC), rapid visco analyser (RVA), and oscillatory dynamic rheometry. The data obtained from the DSC thermogram and the RVA profiles were fitt...

Inter-nesting movements and habitat-use of adult female Kemp’s ridley turtles in the Gulf of Mexico

USGS Publications Warehouse

Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Bucklin, David N.; Iverson, Autumn; Rubio, Cynthia; Backof, Thomas F.; Burchfield, Patrick M.; Gonzales Diaz Miron, Raul de Jesus; Dutton, Peter H.; Frey, Amy; Peña, Jaime; Gamez, Daniel Gomez; Martinez, Hector J.; Ortiz, Jaime

2017-01-01

Species vulnerability is increased when individuals congregate in restricted areas for breeding; yet, breeding habitats are not well defined for many marine species. Identification and quantification of these breeding habitats are essential to effective conservation. Satellite telemetry and switching state-space modeling (SSM) were used to define inter-nesting habitat of endangered Kemp’s ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. Turtles were outfitted with satellite transmitters after nesting at Padre Island National Seashore, Texas, USA, from 1998 through 2013 (n = 60); Rancho Nuevo, Tamaulipas, Mexico, during 2010 and 2011 (n = 11); and Tecolutla, Veracruz, Mexico, during 2012 and 2013 (n = 11). These sites span the range of nearly all nesting by this species. Inter-nesting habitat lies in a narrow band of nearshore western Gulf of Mexico waters in the USA and Mexico, with mean water depth of 14 to 19 m within a mean distance to shore of 6 to 11 km as estimated by 50% kernel density estimate, α-Hull, and minimum convex polygon methodologies. Turtles tracked during the inter-nesting period moved, on average, 17.5 km/day and a mean total distance of 398 km. Mean home ranges occupied were 725 to 2948 km2. Our results indicate that these nearshore western Gulf waters represent critical inter-nesting habitat for this species, where threats such as shrimp trawling and oil and gas platforms also occur. Up to half of all adult female Kemp’s ridleys occupy this habitat for weeks to months during each nesting season. Because inter-nesting habitat for this species is concentrated in nearshore waters of the western Gulf of Mexico in both Mexico and the USA, international collaboration is needed to protect this essential habitat and the turtles occurring within it.

Inter-nesting movements and habitat-use of adult female Kemp’s ridley turtles in the Gulf of Mexico

PubMed Central

Hart, Kristen M.; Fujisaki, Ikuko; Bucklin, David; Iverson, Autumn R.; Rubio, Cynthia; Backof, Thomas F.; Burchfield, Patrick M.; de Jesus Gonzales Diaz Miron, Raul; Dutton, Peter H.; Frey, Amy; Peña, Jaime; Gomez Gamez, Daniel; Martinez, Hector J.; Ortiz, Jaime

2017-01-01

Species vulnerability is increased when individuals congregate in restricted areas for breeding; yet, breeding habitats are not well defined for many marine species. Identification and quantification of these breeding habitats are essential to effective conservation. Satellite telemetry and switching state-space modeling (SSM) were used to define inter-nesting habitat of endangered Kemp’s ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. Turtles were outfitted with satellite transmitters after nesting at Padre Island National Seashore, Texas, USA, from 1998 through 2013 (n = 60); Rancho Nuevo, Tamaulipas, Mexico, during 2010 and 2011 (n = 11); and Tecolutla, Veracruz, Mexico, during 2012 and 2013 (n = 11). These sites span the range of nearly all nesting by this species. Inter-nesting habitat lies in a narrow band of nearshore western Gulf of Mexico waters in the USA and Mexico, with mean water depth of 14 to 19 m within a mean distance to shore of 6 to 11 km as estimated by 50% kernel density estimate, α-Hull, and minimum convex polygon methodologies. Turtles tracked during the inter-nesting period moved, on average, 17.5 km/day and a mean total distance of 398 km. Mean home ranges occupied were 725 to 2948 km2. Our results indicate that these nearshore western Gulf waters represent critical inter-nesting habitat for this species, where threats such as shrimp trawling and oil and gas platforms also occur. Up to half of all adult female Kemp’s ridleys occupy this habitat for weeks to months during each nesting season. Because inter-nesting habitat for this species is concentrated in nearshore waters of the western Gulf of Mexico in both Mexico and the USA, international collaboration is needed to protect this essential habitat and the turtles occurring within it. PMID:28319178

Distinct Roles of the DmNav and DSC1 Channels in the Action of DDT and Pyrethroids

PubMed Central

Rinkevich, Frank D.; Du, Yuzhe; Tolinski, Josh; Ueda, Atsushi; Wu, Chun-Fang; Zhorov, Boris S.; Dong, Ke

2015-01-01

Voltage-gated sodium channels (Nav channels) are critical for electrical signaling in the nervous system and are the primary targets of the insecticides DDT and pyrethroids. In Drosophila melanogaster, besides the canonical Nav channel, Para (also called DmNav), there is a sodium channel-like cation channel called DSC1 (Drosophila sodium channel 1). Temperature-sensitive paralytic mutations in DmNav (parats) confer resistance to DDT and pyrethroids, whereas DSC1 knockout flies exhibit enhanced sensitivity to pyrethroids. To further define the roles and interaction of DmNav and DSC1 channels in DDT and pyrethroid neurotoxicology, we generated a DmNav/DSC1 double mutant line by introducing a parats1 allele (carrying the I265N mutation) into a DSC1 knockout line. We confirmed that the I265N mutation reduced the sensitivity to two pyrethroids, permethrin and deltamethrin of a DmNav variant expressed in Xenopus oocytes. Computer modeling predicts that the I265N mutation confers pyrethroid resistance by allosterically altering the second pyrethroid receptor site on the DmNav channel. Furthermore, we found that I265N-mediated pyrethroid resistance in parats1 mutant flies was almost completely abolished in parats1;DSC1−/− double mutant flies. Unexpectedly, however, the DSC1 knockout flies were less sensitive to DDT, compared to the control flies (w1118A), and the parats1;DSC1−/− double mutant flies were even more resistant to DDT compared to the DSC1 knockout or parats1 mutant. Our findings revealed distinct roles of the DmNav and DSC1 channels in the neurotoxicology of DDT vs. pyrethroids and implicate the exciting possibility of using DSC1 channel blockers or modifiers in the management of pyrethroid resistance. PMID:25687544

Distinct roles of the DmNav and DSC1 channels in the action of DDT and pyrethroids.

PubMed

Rinkevich, Frank D; Du, Yuzhe; Tolinski, Josh; Ueda, Atsushi; Wu, Chun-Fang; Zhorov, Boris S; Dong, Ke

2015-03-01

Voltage-gated sodium channels (Nav channels) are critical for electrical signaling in the nervous system and are the primary targets of the insecticides DDT and pyrethroids. In Drosophila melanogaster, besides the canonical Nav channel, Para (also called DmNav), there is a sodium channel-like cation channel called DSC1 (Drosophila sodium channel 1). Temperature-sensitive paralytic mutations in DmNav (para(ts)) confer resistance to DDT and pyrethroids, whereas DSC1 knockout flies exhibit enhanced sensitivity to pyrethroids. To further define the roles and interaction of DmNav and DSC1 channels in DDT and pyrethroid neurotoxicology, we generated a DmNav/DSC1 double mutant line by introducing a para(ts1) allele (carrying the I265N mutation) into a DSC1 knockout line. We confirmed that the I265N mutation reduced the sensitivity to two pyrethroids, permethrin and deltamethrin of a DmNav variant expressed in Xenopus oocytes. Computer modeling predicts that the I265N mutation confers pyrethroid resistance by allosterically altering the second pyrethroid receptor site on the DmNav channel. Furthermore, we found that I265N-mediated pyrethroid resistance in para(ts1) mutant flies was almost completely abolished in para(ts1);DSC1(-/-) double mutant flies. Unexpectedly, however, the DSC1 knockout flies were less sensitive to DDT, compared to the control flies (w(1118A)), and the para(ts1);DSC1(-/-) double mutant flies were even more resistant to DDT compared to the DSC1 knockout or para(ts1) mutant. Our findings revealed distinct roles of the DmNav and DSC1 channels in the neurotoxicology of DDT vs. pyrethroids and implicate the exciting possibility of using DSC1 channel blockers or modifiers in the management of pyrethroid resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

DSC of human hair: a tool for claim support or incorrect data analysis?

PubMed

Popescu, C; Gummer, C

2016-10-01

Differential scanning calorimetry (DSC) data are increasingly used to substantiate product claims of hair repair. Decreasing peak temperatures may indicate structural changes and chemical damage. Increasing the DSC, wet peak temperature is, therefore, often considered as proof of hair repair. A detailed understanding of the technique and hair structure indicates that this may not be a sound approach. Surveying the rich literature on the use of dynamic thermal analysis (DTA) and differential scanning calorimetry (DSC) for the analyses of human hair and the effect of cosmetic treatments, we underline some of the problems of hair structure and data interpretation. To overcome some of the difficulties of data interpretation, we advise that DSC acquired data should be supported by other techniques when used for claim substantiation. In this way, one can provide meaningful interpretation of the hair science and robust data for product claims support. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Implementation of DSC model and application for analysis of field pile tests under cyclic loading

NASA Astrophysics Data System (ADS)

Shao, Changming; Desai, Chandra S.

2000-05-01

The disturbed state concept (DSC) model, and a new and simplified procedure for unloading and reloading behavior are implemented in a nonlinear finite element procedure for dynamic analysis for coupled response of saturated porous materials. The DSC model is used to characterize the cyclic behavior of saturated clays and clay-steel interfaces. In the DSC, the relative intact (RI) behavior is characterized by using the hierarchical single surface (HISS) plasticity model; and the fully adjusted (FA) behavior is modeled by using the critical state concept. The DSC model is validated with respect to laboratory triaxial tests for clay and shear tests for clay-steel interfaces. The computer procedure is used to predict field behavior of an instrumented pile subjected to cyclic loading. The predictions provide very good correlation with the field data. They also yield improved results compared to those from a HISS model with anisotropic hardening, partly because the DSC model allows for degradation or softening and interface response.

Functional characterization of the Dsc E3 ligase complex in the citrus postharvest pathogen Penicillium digitatum.

PubMed

Ruan, Ruoxin; Chung, Kuang-Ren; Li, Hongye

2017-12-01

Sterol regulatory element binding proteins (SREBPs) are required for sterol homeostasis in eukaryotes. Activation of SREBPs is regulated by the Dsc E3 ligase complex in Schizosaccharomyces pombe and Aspergillus spp. Previous studies indicated that an SREBP-coding gene PdsreA is required for fungicide resistance and ergosterol biosynthesis in the citrus postharvest pathogen Penicillium digitatum. In this study, five genes, designated PddscA, PddscB, PddscC, PddscD, and PddscE encoding the Dsc E3 ligase complex were characterized to be required for fungicide resistance, ergosterol biosynthesis and CoCl 2 tolerance in P. digitatum. Each of the dsc genes was inactivated by target gene disruption and the resulted phenotypes were analyzed and compared. Genetic analysis reveals that, of five Dsc complex components, PddscB is the core subunit gene in P. digitatum. Although the resultant dsc mutants were able to infect citrus fruit and induce maceration lesions as the wild-type, the mutants rarely produced aerial mycelia on affected citrus fruit peels. P. digitatum Dsc proteins regulated not only the expression of genes involved in ergosterol biosynthesis but also that of PdsreA. Yeast two-hybrid assays revealed a direct interaction between the PdSreA protein and the Dsc proteins. Ectopic expression of the PdSreA N-terminus restored fungicide resistance in the dsc mutants. Our results provide important evidence to understand the mechanisms underlying SREBP activation and regulation of ergosterol biosynthesis in plant pathogenic fungi. Copyright © 2017 Elsevier GmbH. All rights reserved.

Degradation of components in drug formulations: a comparison between HPLC and DSC methods.

PubMed

Ceschel, G C; Badiello, R; Ronchi, C; Maffei, P

2003-08-08

Information about the stability of drug components and drug formulations is needed to predict the shelf-life of the final products. The studies on the interaction between the drug and the excipients may be carried out by means of accelerated stability tests followed by analytical determination of the active principle (HPLC and other methods) and by means of the differential scanning calorimetry (DSC). This research has been focused to the acetyl salicylic acid (ASA) physical-chemical characterisation by using DSC method in order to evaluate its compatibility with some of the most used excipients. It was possible to show, with the DSC method, the incompatibility of magnesium stearate with ASA; the HPLC data confirm the reduction of ASA concentration in the presence of magnesium stearate. With the other excipients the characteristic endotherms of the drug were always present and no or little degradation was observed with the accelerated stability tests. Therefore, the results with the DSC method are comparable and in good agreement with the results obtained with other methods.

The characterization of cytosolic glutathione transferase from four species of sea turtles: loggerhead (Caretta caretta), green (Chelonia mydas), olive ridley (Lepidochelys olivacea), and hawksbill (Eretmochelys imbricata).

PubMed

Richardson, Kristine L; Gold-Bouchot, Gerardo; Schlenk, Daniel

2009-08-01

Glutathione s-transferases (GST) play a critical role in the detoxification of exogenous and endogenous electrophiles, as well as the products of oxidative stress. As compared to mammals, GST activity has not been extensively characterized in reptiles. Throughout the globe, most sea turtle populations face the risk of extinction. Of the natural and anthropogenic threats to sea turtles, the effects of environmental chemicals and related biochemical mechanisms, such as GST catalyzed detoxification, are probably the least understood. In the present study, GST activity was characterized in four species of sea turtles with varied life histories and feeding strategies: loggerhead (Caretta caretta), green (Chelonia mydas), olive ridley (Lepidochelys olivacea), and hawksbill (Eretmochelys imbricata). Although similar GST kinetics was observed between species, rates of catalytic activities using class-specific substrates show inter- and intra-species variation. GST from the spongivorous hawksbill sea turtle shows 3-4.5 fold higher activity with the substrate 4-nitrobenzylchloride than the other 3 species. GST from the herbivorous green sea turtle shows 3 fold higher activity with the substrate ethacrynic acid than the carnivorous olive ridley sea turtle. The results of this study may provide insight into differences in biotransformation potential in the four species of sea turtles and the possible health impacts of contaminant biotransformation by sea turtles.

Comparative kinetic analysis on thermal degradation of some cephalosporins using TG and DSC data

PubMed Central

2013-01-01

Background The thermal decomposition of cephalexine, cefadroxil and cefoperazone under non-isothermal conditions using the TG, respectively DSC methods, was studied. In case of TG, a hyphenated technique, including EGA, was used. Results The kinetic analysis was performed using the TG and DSC data in air for the first step of cephalosporin’s decomposition at four heating rates. The both TG and DSC data were processed according to an appropriate strategy to the following kinetic methods: Kissinger-Akahira-Sunose, Friedman, and NPK, in order to obtain realistic kinetic parameters, even if the decomposition process is a complex one. The EGA data offer some valuable indications about a possible decomposition mechanism. The obtained data indicate a rather good agreement between the activation energy’s values obtained by different methods, whereas the EGA data and the chemical structures give a possible explanation of the observed differences on the thermal stability. A complete kinetic analysis needs a data processing strategy using two or more methods, but the kinetic methods must also be applied to the different types of experimental data (TG and DSC). Conclusion The simultaneous use of DSC and TG data for the kinetic analysis coupled with evolved gas analysis (EGA) provided us a more complete picture of the degradation of the three cephalosporins. It was possible to estimate kinetic parameters by using three different kinetic methods and this allowed us to compare the Ea values obtained from different experimental data, TG and DSC. The thermodegradation being a complex process, the both differential and integral methods based on the single step hypothesis are inadequate for obtaining believable kinetic parameters. Only the modified NPK method allowed an objective separation of the temperature, respective conversion influence on the reaction rate and in the same time to ascertain the existence of two simultaneous steps. PMID:23594763

DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

PubMed

Ruano, M V; Ribes, J; Seco, A; Ferrer, J

2011-01-01

This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP.

Kuipers works with DSC Hardware in the U.S. Laboratory

NASA Image and Video Library

2012-01-16

ISS030-E-155917 (16 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares to place Diffusion Soret Coefficient (DSC) hardware in stowage containers in the Destiny laboratory of the International Space Station.

Forensic characterization of HDPE pipes by DSC.

PubMed

Sajwan, Madhuri; Aggarwal, Saroj; Singh, R B

2008-03-05

The melting behavior of 28 high density polyethylene (HDPE) pipe samples manufactured and supplied by 13 different manufacturers in India was examined by 'differential scanning calorimetry (DSC)' to find out if this parameter could be used in differentiating between these HDPE pipe samples which are chemically the same and being manufactured by different manufacturer. The results indicate that the melting temperature may serve as the useful criteria for differentiating HDPE (i) pipe samples from different sources and (ii) samples of different diameter from the same source.

Estimation of Temperature Range for Cryo Cutting of Frozen Mackerel using DSC

NASA Astrophysics Data System (ADS)

Okamoto, Kiyoshi; Hagura, Yoshio; Suzuki, Kanichi

Frozen mackerel flesh was subjected to measurement of its fracture stress (bending energy) in a low temperature range. The optimum conditions for low temperature cutting, "cryo cutting," were estimated from the results of enthalpy changes measured by a differential scanning calorimeter (DSC). There were two enthalpy changes for gross transition on the DSC chart for mackerel, one was at -63°C to -77°C and the other at -96°C to -112°C. Thus we estimated that mackerel was able to cut by bending below -63°C and that there would be a great decrease in bending energy occurring at around -77°C and -112°C. In testing, there were indeed two great decreases of bending energy for the test pieces of mackerel that had been frozen at -40°C, one was at -70°C to -90°C and the other was at -100°C to -120°C. Therefore, the test pieces of mackerel could be cut by bending at -70°C. The results showed that the DSC measurement of mackerel flesh gave a good estimation of the appropriate cutting temperature of mackerel.

Temperature-modulated DSC provides new insight about nickel-titanium wire transformations.

PubMed

Brantley, William A; Iijima, Masahiro; Grentzer, Thomas H

2003-10-01

Differential scanning calorimetry (DSC) is a well-known method for investigating phase transformations in nickel-titanium orthodontic wires; the microstructural phases and phase transformations in these wires have central importance for their clinical performance. The purpose of this study was to use the more recently developed technique of temperature-modulated DSC (TMDSC) to gain insight into transformations in 3 nickel-titanium orthodontic wires: Neo Sentalloy (GAC International, Islandia, NY), 35 degrees C Copper Ni-Ti (Ormco, Glendora, Calif) and Nitinol SE (3M Unitek, Monrovia, Calif). In the oral environment, the first 2 superelastic wires have shape memory, and the third wire has superelastic behavior but not shape memory. All wires had cross-section dimensions of 0.016 x 0.022 in. Archwires in the as-received condition and after bending 135 degrees were cut into 5 or 6 segments for test specimens. TMDSC analyses (Model 2910 DSC, TA Instruments, Wilmington, Del) were conducted between -125 degrees C and 100 degrees C, using a linear heating and cooling rate of 2 degrees C per min, an oscillation amplitude of 0.318 degrees C with a period of 60 seconds, and helium as the purge gas. For all 3 wire alloys, strong low-temperature martensitic transformations, resolved on the nonreversing heat-flow curves, were not present on the reversing heat-flow curves, and bending appeared to increase the enthalpy change for these peaks in some cases. For Neo Sentalloy, TMDSC showed that transformation between martensitic and austenitic nickel-titanium, suggested as occurring directly in the forward and reverse directions by conventional DSC, was instead a 2-step process involving the R-phase. Two-step transformations in the forward and reverse directions were also found for 35 degrees C Copper Ni-Ti and Nitinol SE. The TMDSC results show that structural transformations in these wires are complex. Some possible clinical implications of these observations are discussed.

Comparing Single-Point and Multi-point Calibration Methods in Modulated DSC

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

Van Buskirk, Caleb Griffith

2017-06-14

Heat capacity measurements for High Density Polyethylene (HDPE) and Ultra-high Molecular Weight Polyethylene (UHMWPE) were performed using Modulated Differential Scanning Calorimetry (mDSC) over a wide temperature range, -70 to 115 °C, with a TA Instruments Q2000 mDSC. The default calibration method for this instrument involves measuring the heat capacity of a sapphire standard at a single temperature near the middle of the temperature range of interest. However, this method often fails for temperature ranges that exceed a 50 °C interval, likely because of drift or non-linearity in the instrument's heat capacity readings over time or over the temperature range. Therefore,more » in this study a method was developed to calibrate the instrument using multiple temperatures and the same sapphire standard.« less

47 CFR 80.359 - Frequencies for digital selective calling (DSC).

Code of Federal Regulations, 2013 CFR

2013-10-01

... calling frequencies for use by authorized ship and coast stations for general purpose DSC. There are three.... The “Series A” designation includes coast stations along, and ship stations in, the Atlantic Ocean... location of the called station and propagation conditions. Acknowledgement is made on the paired frequency...

47 CFR 80.359 - Frequencies for digital selective calling (DSC).

Code of Federal Regulations, 2012 CFR

2012-10-01

... calling frequencies for use by authorized ship and coast stations for general purpose DSC. There are three.... The “Series A” designation includes coast stations along, and ship stations in, the Atlantic Ocean... location of the called station and propagation conditions. Acknowledgement is made on the paired frequency...

47 CFR 80.359 - Frequencies for digital selective calling (DSC).

Code of Federal Regulations, 2014 CFR

2014-10-01

... calling frequencies for use by authorized ship and coast stations for general purpose DSC. There are three.... The “Series A” designation includes coast stations along, and ship stations in, the Atlantic Ocean... location of the called station and propagation conditions. Acknowledgement is made on the paired frequency...

47 CFR 80.103 - Digital selective calling (DSC) operating procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... DSC “Acknowledgment of distress calls” and “Distress relays.” (See subpart W of this part.) (d) Group calls to vessels under the common control of a single entity are authorized. A group call identity may... (ITU), Place des Nations, CH-1211 Geneva 20, Switzerland. [68 FR 46961, Aug. 7, 2003, as amended at 73...

47 CFR 80.103 - Digital selective calling (DSC) operating procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... DSC “Acknowledgment of distress calls” and “Distress relays.” (See subpart W of this part.) (d) Group calls to vessels under the common control of a single entity are authorized. A group call identity may... (ITU), Place des Nations, CH-1211 Geneva 20, Switzerland. [68 FR 46961, Aug. 7, 2003, as amended at 73...

Reticulation of Aqueous Polyurethane Systems Controlled by DSC Method

PubMed Central

Cakic, Suzana; Lacnjevac, Caslav; Rajkovic, Milos B.; Raskovic, Ljiljana; Stamenkovic, Jakov

2006-01-01

The DSC method has been employed to monitor the kinetics of reticulation of aqueous polyurethane systems without catalysts, and with the commercial catalyst of zirconium (CAT®XC-6212) and the highly selective manganese catalyst, the complex Mn(III)-diacetylacetonemaleinate (MAM). Among the polyol components, the acrylic emulsions were used for reticulation in this research, and as suitable reticulation agents the water emulsible aliphatic polyisocyanates based on hexamethylendoisocyanate with the different contents of NCO-groups were employed. On the basis of DSC analysis, applying the methods of Kissinger, Freeman-Carroll and Crane-Ellerstein the pseudo kinetic parameters of the reticulation reaction of aqueous systems were determined. The temperature of the examination ranged from 50°C to 450°C with the heat rate of 0.5°C/min. The reduction of the activation energy and the increase of the standard deviation indicate the catalytic action of the selective catalysts of zirconium and manganese. The impact of the catalysts on the reduction of the activation energy is the strongest when using the catalysts of manganese and applying all the three afore-said methods. The least aberrations among the stated methods in defining the kinetic parameters were obtained by using the manganese catalyst.

Determining the main thermodynamic parameters of caffeine melting by means of DSC

NASA Astrophysics Data System (ADS)

Agafonova, E. V.; Moshchenskii, Yu. V.; Tkachenko, M. L.

2012-06-01

The temperature and enthalpy of the melting of caffeine, which are 235.5 ± 0.1°C and 19.6 ± 0.2 kJ/mol, respectively, are determined by DSC. The melting entropy and the cryoscopic constant of caffeine are calculated.

Determination of the heat of hydride formation/decomposition by high-pressure differential scanning calorimetry (HP-DSC).

PubMed

Rongeat, Carine; Llamas-Jansa, Isabel; Doppiu, Stefania; Deledda, Stefano; Borgschulte, Andreas; Schultz, Ludwig; Gutfleisch, Oliver

2007-11-22

Among the thermodynamic properties of novel materials for solid-state hydrogen storage, the heat of formation/decomposition of hydrides is the most important parameter to evaluate the stability of the compound and its temperature and pressure of operation. In this work, the desorption and absorption behaviors of three different classes of hydrides are investigated under different hydrogen pressures using high-pressure differential scanning calorimetry (HP-DSC). The HP-DSC technique is used to estimate the equilibrium pressures as a function of temperature, from which the heat of formation is derived. The relevance of this procedure is demonstrated for (i) magnesium-based compounds (Ni-doped MgH2), (ii) Mg-Co-based ternary hydrides (Mg-CoHx) and (iii) Alanate complex hydrides (Ti-doped NaAlH4). From these results, it can be concluded that HP-DSC is a powerful tool to obtain a good approximation of the thermodynamic properties of hydride compounds by a simple and fast study of desorption and absorption properties under different pressures.

Characterization of the Polycaprolactone Melt Crystallization: Complementary Optical Microscopy, DSC, and AFM Studies

PubMed Central

Speranza, V.; Sorrentino, A.; De Santis, F.; Pantani, R.

2014-01-01

The first stages of the crystallization of polycaprolactone (PCL) were studied using several techniques. The crystallization exotherms measured by differential scanning calorimetry (DSC) were analyzed and compared with results obtained by polarized optical microscopy (POM), rheology, and atomic force microscope (AFM). The experimental results suggest a strong influence of the observation scale. In particular, the AFM, even if limited on time scale, appears to be the most sensitive technique to detect the first stages of crystallization. On the contrary, at least in the case analysed in this work, rheology appears to be the least sensitive technique. DSC and POM provide closer results. This suggests that the definition of induction time in the polymer crystallization is a vague concept that, in any case, requires the definition of the technique used for its characterization. PMID:24523644

Characterization of the polycaprolactone melt crystallization: complementary optical microscopy, DSC, and AFM studies.

PubMed

Speranza, V; Sorrentino, A; De Santis, F; Pantani, R

2014-01-01

The first stages of the crystallization of polycaprolactone (PCL) were studied using several techniques. The crystallization exotherms measured by differential scanning calorimetry (DSC) were analyzed and compared with results obtained by polarized optical microscopy (POM), rheology, and atomic force microscope (AFM). The experimental results suggest a strong influence of the observation scale. In particular, the AFM, even if limited on time scale, appears to be the most sensitive technique to detect the first stages of crystallization. On the contrary, at least in the case analysed in this work, rheology appears to be the least sensitive technique. DSC and POM provide closer results. This suggests that the definition of induction time in the polymer crystallization is a vague concept that, in any case, requires the definition of the technique used for its characterization.

The Effects of Feeding on Hematological and Plasma Biochemical Profiles in Green (Chelonia mydas) and Kemp's Ridley (Lepidochelys kempii) Sea Turtles

PubMed Central

Anderson, Eric T.; Minter, Larry J.; Clarke, Elsburgh O.; Mroch, Raymond M.; Beasley, Jean F.; Harms, Craig A.

2011-01-01

In mammals, lipemic blood from sampling too soon after an animal feeds can have substantial effects on biochemical values. Plasma biochemical values in reptiles may be affected by species, age, season, and nutritional state. However, fasting status is not routinely considered when sampling reptile blood. In this paper, we evaluated 2-hour postprandial blood collection in two sea turtle species to investigate the effects of feeding on hematological and plasma biochemical values. Feeding had no significant effects on hematological values in either species, nor did it have an effect on plasma biochemistry values in Kemp's ridley sea turtles. In postprandial green turtles, total protein, albumin, ALP, AST, ALT, amylase, and cholesterol increased significantly, and chloride decreased significantly. Although statistically significant changes were observed, the median percent differences between pre- and postprandial values did not exceed 10% for any of these analytes and would not likely alter the clinical interpretation. PMID:21776356

An elegant access to formation and vaporization enthalpies of ionic liquids by indirect DSC experiment and "in silico" calculations.

PubMed

Verevkin, Sergey P; Zaitsau, Dzmitry H; Emel'yanenko, Vladimir N; Schick, Christoph; Jayaraman, Saivenkataraman; Maginn, Edward J

2012-07-14

We used DSC for determination of the reaction enthalpy of the synthesis of the ionic liquid [C(4)mim][Cl]. A combination of DSC and quantum chemical calculations presents a new, indirect way to study thermodynamics of ionic liquids. The new procedure was validated with two direct experimental measurements and MD simulations.

Energetics during hatchling dispersal of the olive ridley turtle Lepidochelys olivacea using doubly labeled water.

PubMed

Clusella Trullas, Susana; Spotila, James R; Paladino, Frank V

2006-01-01

Studies of metabolism are central to the understanding of the ecology, behavior, and evolution of reptiles. This study focuses on one phase of the sea turtle life cycle, hatchling dispersal, and gives insight into energetic constraints that dispersal imposes on hatchlings. Hatchling dispersal is an energetically expensive phase in the life cycle of the olive ridley turtle Lepidochelys olivacea. Field metabolic rates (FMRs), determined using the doubly labeled water (DLW) method, for L. olivacea hatchlings digging out of their nest chamber, crawling at the sand surface, and swimming were five, four, and seven times, respectively, the resting metabolic rate (RMR). The cost of swimming was 1.5 and 1.8 times the cost of the digging and crawling phases, respectively, and we estimated that if L. olivacea hatchlings swim at frenzy levels, they can rely on yolk reserves to supply energy for only 3-6 d once they reach the ocean. We compared our RMR and FMR values by establishing an interspecific RMR mass-scaling relationship for a wide range of species in the order Testudines and found a scaling exponent of 1.06. This study demonstrates the feasibility of using the DLW method to estimate energetic costs of free-living sea turtle hatchlings and emphasizes the need for metabolic studies in various life-history stages.

Measuring the glass transition temperature of EPDM roofing materials: Comparison of DMA, TMA, and DSC techniques

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

Paroli, R.M.; Penn, J.

1994-09-01

Two ethylene-propylene-diene monomer (EPDM) roofing membranes were aged at 100 C for 7 and 28 days. The T{sub g} of these membranes was then determined by dynamic mechanical analysis (DMA), thermomechanical analysis (TMA), and differential scanning calorimetry (DSC) and the results compared. It was found that: (1) T{sub g} data can be obtained easily using the DMA and TMA techniques. The DSC method requires greater care due to the broad step change in the baseline which is associated with heavily plasticized materials. (2) The closest correspondence between techniques was for TMA and DSC (half-height). The latter, within experimental error, yieldedmore » the same glass transition temperature before and after heat-aging. (3) The peak maxima associated with tan{delta} and E{double_prime} measurements should be cited with T{sub g} values as significant differences can exist. (4) The T{sub g}(E{double_prime}) values were closer to the T{sub g}(TMA) and T{sub g}(DSC) data than were the T{sub g}(tan{delta}) values. Data obtained at 1 Hz (or possibly less) should be used when making comparisons based on various techniques. An assessment of T{sub g} values indicated that EPDM 112 roofing membrane is more stable than the EPDM 111 membrane. The T{sub g} for EPDM 112 did not change significantly with heat-aging for 28 days at 130 C.« less

Level II scour analysis for Bridge 37 (DUXBTH00120037) on Town Highway 12, crossing Ridley Brook, Duxbury, Vermont

USGS Publications Warehouse

Wild, Emily C.; Ivanhoff, Michael A.

1997-01-01

This report provides the results of a detailed Level II analysis of scour potential at structure DUXBTH00120037 on Town Highway 12 crossing Ridley Brook, Duxbury, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in north central Vermont. The 10.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and downstream of the bridge. In the study area, Ridley Brook has an incised, straight channel with a slope of approximately 0.04 ft/ft, an average channel top width of 67 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 123 mm (0.404 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 1, 1996, indicated that the reach was stable. The Town Highway 12 crossing of Ridley Brook is a 33-ft-long, two-lane bridge consisting of five 30-ft steel rolled beams (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 30 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 50 degrees to the opening while the measured opening-skew-to-roadway is 20 degrees. A scour hole 2 ft deeper than the mean thalweg depth was observed along the right abutment and downstream

Combining Diffusion Tensor Metrics and DSC Perfusion Imaging: Can It Improve the Diagnostic Accuracy in Differentiating Tumefactive Demyelination from High-Grade Glioma?

PubMed

Hiremath, S B; Muraleedharan, A; Kumar, S; Nagesh, C; Kesavadas, C; Abraham, M; Kapilamoorthy, T R; Thomas, B

2017-04-01

Tumefactive demyelinating lesions with atypical features can mimic high-grade gliomas on conventional imaging sequences. The aim of this study was to assess the role of conventional imaging, DTI metrics ( p:q tensor decomposition), and DSC perfusion in differentiating tumefactive demyelinating lesions and high-grade gliomas. Fourteen patients with tumefactive demyelinating lesions and 21 patients with high-grade gliomas underwent brain MR imaging with conventional, DTI, and DSC perfusion imaging. Imaging sequences were assessed for differentiation of the lesions. DTI metrics in the enhancing areas and perilesional hyperintensity were obtained by ROI analysis, and the relative CBV values in enhancing areas were calculated on DSC perfusion imaging. Conventional imaging sequences had a sensitivity of 80.9% and specificity of 57.1% in differentiating high-grade gliomas ( P = .049) from tumefactive demyelinating lesions. DTI metrics ( p : q tensor decomposition) and DSC perfusion demonstrated a statistically significant difference in the mean values of ADC, the isotropic component of the diffusion tensor, the anisotropic component of the diffusion tensor, the total magnitude of the diffusion tensor, and rCBV among enhancing portions in tumefactive demyelinating lesions and high-grade gliomas ( P ≤ .02), with the highest specificity for ADC, the anisotropic component of the diffusion tensor, and relative CBV (92.9%). Mean fractional anisotropy values showed no significant statistical difference between tumefactive demyelinating lesions and high-grade gliomas. The combination of DTI and DSC parameters improved the diagnostic accuracy (area under the curve = 0.901). Addition of a heterogeneous enhancement pattern to DTI and DSC parameters improved it further (area under the curve = 0.966). The sensitivity increased from 71.4% to 85.7% after the addition of the enhancement pattern. DTI and DSC perfusion add profoundly to conventional imaging in differentiating tumefactive

Correlation of Tumor Immunohistochemistry with Dynamic Contrast-Enhanced and DSC-MRI Parameters in Patients with Gliomas.

PubMed

Nguyen, T B; Cron, G O; Bezzina, K; Perdrizet, K; Torres, C H; Chakraborty, S; Woulfe, J; Jansen, G H; Thornhill, R E; Zanette, B; Cameron, I G

2016-12-01

Tumor CBV is a prognostic and predictive marker for patients with gliomas. Tumor CBV can be measured noninvasively with different MR imaging techniques; however, it is not clear which of these techniques most closely reflects histologically-measured tumor CBV. Our aim was to investigate the correlations between dynamic contrast-enhanced and DSC-MR imaging parameters and immunohistochemistry in patients with gliomas. Forty-three patients with a new diagnosis of glioma underwent a preoperative MR imaging examination with dynamic contrast-enhanced and DSC sequences. Unnormalized and normalized cerebral blood volume was obtained from DSC MR imaging. Two sets of plasma volume and volume transfer constant maps were obtained from dynamic contrast-enhanced MR imaging. Plasma volume obtained from the phase-derived vascular input function and bookend T1 mapping (Vp_Φ) and volume transfer constant obtained from phase-derived vascular input function and bookend T1 mapping (K trans _Φ) were determined. Plasma volume obtained from magnitude-derived vascular input function (Vp_SI) and volume transfer constant obtained from magnitude-derived vascular input function (K trans _SI) were acquired, without T1 mapping. Using CD34 staining, we measured microvessel density and microvessel area within 3 representative areas of the resected tumor specimen. The Mann-Whitney U test was used to test for differences according to grade and degree of enhancement. The Spearman correlation was performed to determine the relationship between dynamic contrast-enhanced and DSC parameters and histopathologic measurements. Microvessel area, microvessel density, dynamic contrast-enhanced, and DSC-MR imaging parameters varied according to the grade and degree of enhancement (P < .05). A strong correlation was found between microvessel area and Vp_Φ and between microvessel area and unnormalized blood volume (r s ≥ 0.61). A moderate correlation was found between microvessel area and normalized blood

Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

PubMed

Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

2013-07-01

Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment. Copyright © 2013 Elsevier Inc. All rights reserved.

Longitudinal DSC-MRI for Distinguishing Tumor Recurrence From Pseudoprogression in Patients With a High-grade Glioma.

PubMed

Boxerman, Jerrold L; Ellingson, Benjamin M; Jeyapalan, Suriya; Elinzano, Heinrich; Harris, Robert J; Rogg, Jeffrey M; Pope, Whitney B; Safran, Howard

2017-06-01

For patients with high-grade glioma on clinical trials it is important to accurately assess time of disease progression. However, differentiation between pseudoprogression (PsP) and progressive disease (PD) is unreliable with standard magnetic resonance imaging (MRI) techniques. Dynamic susceptibility contrast perfusion MRI (DSC-MRI) can measure relative cerebral blood volume (rCBV) and may help distinguish PsP from PD. A subset of patients with high-grade glioma on a phase II clinical trial with temozolomide, paclitaxel poliglumex, and concurrent radiation were assessed. Nine patients (3 grade III, 6 grade IV), with a total of 19 enhancing lesions demonstrating progressive enhancement (≥25% increase from nadir) on postchemoradiation conventional contrast-enhanced MRI, had serial DSC-MRI. Mean leakage-corrected rCBV within enhancing lesions was computed for all postchemoradiation time points. Of the 19 progressively enhancing lesions, 10 were classified as PsP and 9 as PD by biopsy/surgery or serial enhancement patterns during interval follow-up MRI. Mean rCBV at initial progressive enhancement did not differ significantly between PsP and PD (2.35 vs. 2.17; P=0.67). However, change in rCBV at first subsequent follow-up (-0.84 vs. 0.84; P=0.001) and the overall linear trend in rCBV after initial progressive enhancement (negative vs. positive slope; P=0.04) differed significantly between PsP and PD. Longitudinal trends in rCBV may be more useful than absolute rCBV in distinguishing PsP from PD in chemoradiation-treated high-grade gliomas with DSC-MRI. Further studies of DSC-MRI in high-grade glioma as a potential technique for distinguishing PsP from PD are indicated.

Metals and metalloids in whole blood and tissues of Olive Ridley turtles (Lepidochelys olivacea) from La Escobilla Beach (Oaxaca, Mexico).

PubMed

Cortés-Gómez, Adriana A; Fuentes-Mascorro, Gisela; Romero, Diego

2014-12-15

Concentrations of eight metals and metalloids (Pb, Cd, Cu, Zn, Mn, Se, Ni and As) were evaluated from 41 nesting females (blood) and 13 dead (tissues) Olive Ridley turtles (Lepidochelys olivacea), a species classified as vulnerable and also listed in Appendix I of the Convention of International Trade in Endangered Species (CITES). The mean blood, liver and kidney lead concentration were 0.02 ± 0.01, 0.11 ± 0.08 and 0.06 ± 0.03 μ gg(-1) ww respectively, values lower than other turtle species and locations, which it could be due to the gradual disuse of leaded gasoline in Mexico and Central America since the 1990s. Mean concentration of cadmium was 0.17 ± 0.08 (blood), 82.88 ± 36.65 (liver) and 150.88 ± 110.9 9μg g(-1) (kidney). To our knowledge, the mean renal cadmium levels found is the highest ever reported worldwide for any sea turtle species, while other six elements showed a concentration similar to other studies in sea turtles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Interactions of tamoxifen with distearoyl phosphatidylcholine multilamellar vesicles: FTIR and DSC studies

NASA Astrophysics Data System (ADS)

Bilge, Duygu; Sahin, Ipek; Kazanci, Nadide; Severcan, Feride

2014-09-01

Interactions of a non-steroidal antiestrogen drug, tamoxifen (TAM), with distearoyl-sn-glycero-3-phosphatidylcholine (DSPC) multilamellar liposomes (MLVs) were investigated as a function of drug concentration (1-15 mol%) by using two noninvasive techniques, namely Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). FTIR spectroscopy results show that increasing TAM concentrations (except 1 mol%) increased the wavenumbers of the CH2 stretching modes, implying an disordering effect for DSPC MLVs both in the gel and liquid crystalline phases. The bandwidth values of the CH2 stretchings except for 1 mol% increased when TAM concentrations increased for DSPC liposomes, indicating an increase in the dynamics of liposomes. The Cdbnd O stretching and PO2- antisymmetric double bond stretching bands were analyzed to study interactions of TAM with head groups of lipids. As the concentrations of TAM increased, dehydration occurred around these functional groups in the polar part of the lipids. The DSC studies on thermal properties of DSPC lipids indicate that TAM eliminated the pre transition, shifted the main phase transition to lower temperatures and broadened the phase transition curve of the liposomes.

Decentralized Adaptive Neural Output-Feedback DSC for Switched Large-Scale Nonlinear Systems.

PubMed

Lijun Long; Jun Zhao

2017-04-01

In this paper, for a class of switched large-scale uncertain nonlinear systems with unknown control coefficients and unmeasurable states, a switched-dynamic-surface-based decentralized adaptive neural output-feedback control approach is developed. The approach proposed extends the classical dynamic surface control (DSC) technique for nonswitched version to switched version by designing switched first-order filters, which overcomes the problem of multiple "explosion of complexity." Also, a dual common coordinates transformation of all subsystems is exploited to avoid individual coordinate transformations for subsystems that are required when applying the backstepping recursive design scheme. Nussbaum-type functions are utilized to handle the unknown control coefficients, and a switched neural network observer is constructed to estimate the unmeasurable states. Combining with the average dwell time method and backstepping and the DSC technique, decentralized adaptive neural controllers of subsystems are explicitly designed. It is proved that the approach provided can guarantee the semiglobal uniformly ultimately boundedness for all the signals in the closed-loop system under a class of switching signals with average dwell time, and the tracking errors to a small neighborhood of the origin. A two inverted pendulums system is provided to demonstrate the effectiveness of the method proposed.

A theoretical framework to model DSC-MRI data acquired in the presence of contrast agent extravasation

NASA Astrophysics Data System (ADS)

Quarles, C. C.; Gochberg, D. F.; Gore, J. C.; Yankeelov, T. E.

2009-10-01

Dynamic susceptibility contrast (DSC) MRI methods rely on compartmentalization of the contrast agent such that a susceptibility gradient can be induced between the contrast-containing compartment and adjacent spaces, such as between intravascular and extravascular spaces. When there is a disruption of the blood-brain barrier, as is frequently the case with brain tumors, a contrast agent leaks out of the vasculature, resulting in additional T1, T2 and T*2 relaxation effects in the extravascular space, thereby affecting the signal intensity time course and reducing the reliability of the computed hemodynamic parameters. In this study, a theoretical model describing these dynamic intra- and extravascular T1, T2 and T*2 relaxation interactions is proposed. The applicability of using the proposed model to investigate the influence of relevant MRI pulse sequences (e.g. echo time, flip angle), and physical (e.g. susceptibility calibration factors, pre-contrast relaxation rates) and physiological parameters (e.g. permeability, blood flow, compartmental volume fractions) on DSC-MRI signal time curves is demonstrated. Such a model could yield important insights into the biophysical basis of contrast-agent-extravasastion-induced effects on measured DSC-MRI signals and provide a means to investigate pulse sequence optimization and appropriate data analysis methods for the extraction of physiologically relevant imaging metrics.

SU-D-18C-02: Feasibility of Using a Short ASL Scan for Calibrating Cerebral Blood Flow Obtained From DSC-MRI

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

Wang, P; Chang, T; Huang, K

2014-06-01

Purpose: This study aimed to evaluate the feasibility of using a short arterial spin labeling (ASL) scan for calibrating the dynamic susceptibility contrast- (DSC-) MRI in a group of patients with internal carotid artery stenosis. Methods: Six patients with unilateral ICA stenosis enrolled in the study on a 3T clinical MRI scanner. The ASL-cerebral blood flow (-CBF) maps were calculated by averaging different number of dynamic points (N=1-45) acquired by using a Q2TIPS sequence. For DSC perfusion analysis, arterial input function was selected to derive the relative cerebral blood flow (rCBF) map and the delay (Tmax) map. Patient-specific CF wasmore » calculated from the mean ASL- and DSC-CBF obtained from three different masks: (1)Tmax< 3s, (2)combined gray matter mask with mask 1, (3)mask 2 with large vessels removed. One CF value was created for each number of averages by using each of the three masks for calibrating the DSC-CBF map. The CF value of the largest number of averages (NL=45) was used to determine the acceptable range(< 10%, <15%, and <20%) of CF values corresponding to the minimally acceptable number of average (NS) for each patient. Results: Comparing DSC CBF maps corrected by CF values of NL (CBFL) in ACA, MCA and PCA territories, all masks resulted in smaller CBF on the ipsilateral side than the contralateral side of the MCA territory(p<.05). The values obtained from mask 1 were significantly different than the mask 3(p<.05). Using mask 3, the medium values of Ns were 4(<10%), 2(<15%) and 2(<20%), with the worst case scenario (maximum Ns) of 25, 4, and 4, respectively. Conclusion: This study found that reliable calibration of DSC-CBF can be achieved from a short pulsed ASL scan. We suggested use a mask based on the Tmax threshold, the inclusion of gray matter only and the exclusion of large vessels for performing the calibration.« less

Taxonomy of the Caribbean sponge Dragmacidon reticulatum (Ridley & Dendy, 1886) (Porifera, Demospongiae, Axinellida), with the description of a new species.

PubMed

Zea, Sven; Pulido, Alejandra

2016-05-25

Although there is a long history of taxonomic investigation in Caribbean sponges, there are still many undescribed species. Furthermore, field observations and corroborating morphological analyses are revealing that what was believed to be single, somewhat variable species, may consist of two or more species, often easier to distinguish once well characterized. This is the case for Dragmacidon reticulatum (Ridley & Dendy, 1886) (Porifera, Demospongiae, Axinellida, Axinellidae), a rather well-known sponge, with an ample distribution and presence in rocky and reef environments of the tropical and subtropical Western Atlantic, with local records in the majority of the countries of the area, from Bermuda to Brazil. Field observations and a detailed review of material from different areas, including some type specimens, led us to the distinction of two different species in terms of external morphology, size of spicules, and skeletal architecture. The distinction was confirmed in the Bahamas and Santa Marta, Colombia, where the two species coexist. One of the species is Dragmacidon reticulatum sensu stricto, but for the other there is need to erect a new name, for which we propose Dragmacidon alvarezae n. sp. The purpose of the present work is to describe, illustrate and compare these two species.

Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)

NASA Technical Reports Server (NTRS)

Ortiz, R. M.; Patterson, R. M.; Wade, C. E.; Byers, F. M.

2000-01-01

Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

Comparative Study Of Various Grades Of Polyethylene By Differential Scanning Calorimetry (DSC) Correlated With Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Jumeau, Richard; Bourson, Patrice; Ferriol, Michel; Lahure, François; Ducos, Franck; Ligneron, Jérôme

2011-05-01

Polyethylene (PE) is a very important material. In 2008, almost 30% of the world plastics production was dedicated to this polymer (70 million tons) [1]. It is a consumer polymer because of its moderate cost of manufacturing and its physical and mechanical properties compatible with various applications in everyday life. Indeed, PE is generally easily processable. It possesses an excellent electric insulation and shock resistance combined with a very good chemical and biological inertia [2]. For each application, there is a particular grade, i.e. a polyethylene with well defined rheological properties. Therefore, it is essential to know how to differentiate these different grades by suitable methods of characterization. Differential Scanning Calorimetry (DSC) is one of the techniques usually used for this purpose. The knowledge of characteristic temperatures such as melting, cold crystallization or glass transition gives information on the viscosity and thus, on the grade of the polymer. DSC also allows the detection of defects, (for example, presence of unmelted pieces). However DSC is a tedious method for on-line quality control, limiting its scope. The determination of the polymer structure represents a major challenge in the industrial world of polymers. Raman spectroscopy, another technique of polymer analysis, is nowadays growing fast because of the advantages it presents. It is a non-destructive method, capable of also giving useful information about the morphology of the polymer. This technique can be perfectly used in industry by means of adapted sensors and devices with more and more reduced dimensions [3]. That technique is used to obtain the characteristic temperatures of PE and information on the polymer structure. The purpose of this article is to establish the correlation between the viscosity of a polymer and its characteristic temperatures obtained by DSC and subsequent possibilities of quality control in industry. These measurements are correlated

Migratory corridors of adult female Kemp’s ridley turtles in the Gulf of Mexico

USGS Publications Warehouse

Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain-Iverson, Autumn R.; Pena, Jaime; Gamez, Daniel Gomez; Gonzales Diaz Miron, Raul de Jesus; Burchfield, Patrick M.; Martinez, Hector J.; Ortiz, Jaime

2016-01-01

For many marine species, locations of migratory pathways are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to define the migratory corridor used by Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. The turtles were tagged after nesting at Padre Island National Seashore, Texas, USA from 1997 to 2014 (PAIS; n = 80); Rancho Nuevo, Tamaulipas, Mexico from 2010 to 2011 (RN; n = 14); Tecolutla, Veracruz, Mexico from 2012 to 2013 (VC; n = 13); and Gulf Shores, Alabama, USA during 2012 (GS; n = 1). The migratory corridor lies in nearshore Gulf of Mexico waters in the USA and Mexico with mean water depth of 26 m and a mean distance of 20 km from the nearest mainland coast. Migration from the nesting beach is a short phenomenon that occurs from late-May through August, with a peak in June. There was spatial similarity of post-nesting migratory pathways for different turtles over a 16 year period. Thus, our results indicate that these nearshore Gulf waters represent a critical migratory habitat for this species. However, there is a gap in our understanding of the migratory pathways used by this and other species to return from foraging grounds to nesting beaches. Therefore, our results highlight the need for tracking reproductive individuals from foraging grounds to nesting beaches. Continued tracking of adult females from PAIS, RN, and VC nesting beaches will allow further study of environmental and bathymetric components of migratory habitat and threats occurring within our defined corridor. Furthermore, the existence of this migratory corridor in nearshore waters of both the USA and Mexico demonstrates that international cooperation is necessary to protect essential migratory habitat for this imperiled species.

DSC investigation of bovine hide collagen at varying degrees of crosslinking and humidities.

PubMed

Schroepfer, Michaela; Meyer, Michael

2017-10-01

Bovine hide collagen (nonCLC; non-CrossLinked Collagen) was analysed by differential scanning calorimetry (DSC) at different hydration degrees and compared with hide collagen samples crosslinked with glutaraldehyde (CLC-GA) and chromium(III) ions (CLC-Cr), respectively. Crosslinking and drying were confirmed to increase the denaturation temperature. Different regions were assigned, that reflect the variation of the influence of water on the denaturation temperature. Furthermore, at moderate hydration degrees, the enthalpies of non-crosslinked collagen increase compared to the fully hydrated state. This reflects a glue-like action of water in the range of 25% hydration. Crosslinking of bovine hide collagen decreases the enthalpy by 25% in the fully hydrated state, even at very low levels of crosslinking This can be explained by intensive effects of the crosslinking agent on the hydration network of the collagen molecules, assuming that the enthalpies are principally a result of hydrogen bonding. At very low water contents DSC peaks of CLC-Cr completely disappear. This could be explained by competition between hydroxosulfochromate(III) complexes and collagen for water. Copyright © 2017 Elsevier B.V. All rights reserved.

Remote Evaluation of Rotational Velocity Using a Quadrant Photo-Detector and a DSC Algorithm

PubMed Central

Zeng, Xiangkai; Zhu, Zhixiong; Chen, Yang

2016-01-01

This paper presents an approach to remotely evaluate the rotational velocity of a measured object by using a quadrant photo-detector and a differential subtraction correlation (DSC) algorithm. The rotational velocity of a rotating object is determined by two temporal-delay numbers at the minima of two DSCs that are derived from the four output signals of the quadrant photo-detector, and the sign of the calculated rotational velocity directly represents the rotational direction. The DSC algorithm does not require any multiplication operations. Experimental calculations were performed to confirm the proposed evaluation method. The calculated rotational velocity, including its amplitude and direction, showed good agreement with the given one, which had an amplitude error of ~0.3%, and had over 1100 times the efficiency of the traditional cross-correlation method in the case of data number N > 4800. The confirmations have shown that the remote evaluation of rotational velocity can be done without any circular division disk, and that it has much fewer error sources, making it simple, accurate and effective for remotely evaluating rotational velocity. PMID:27120607

Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC

NASA Astrophysics Data System (ADS)

Li, Linling; Wang, Xiaoliang; Zhou, Dongshan; Xue, Gi

2013-03-01

We report a diffusion study on the polystyrene/poly(phenylene oxide) (PS/PPO) mixture consisted by the PS and PPO nanoparticles. Diffusion of liquid PS into glassy PPO (l-PS/g-PPO) is promoted by annealing the PS/PPO mixture at several temperatures below Tg of the PPO. By tracing the Tgs of the PS-rich domain behind the diffusion front using DSC, we get the relationships of PS weight fractions and diffusion front advances with the elapsed diffusion times at different diffusion temperatures using the Gordon-Taylor equation and core-shell model. We find that the plots of weight fraction of PS vs. elapsed diffusion times at different temperatures can be converted to a master curve by Time-Temperature superposition, and the shift factors obey the Arrhenius equation. Besides, the diffusion front advances of l-PS into g-PPO show an excellent agreement with the t1/2 scaling law at the beginning of the diffusion process, and the diffusion coefficients of different diffusion temperatures also obey the Arrhenius equation. We believe the diffusion mechanism for l-PS/g-PPO should be the Fickean law rather than the Case II, though there are departures of original linearity at longer diffusion times due to the limited liquid supply system. Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC

DSC studies to evaluate the impact of bio-oil on cold flow properties and oxidation stability of bio-diesel.

PubMed

Garcia-Perez, Manuel; Adams, Thomas T; Goodrum, John W; Das, K C; Geller, Daniel P

2010-08-01

This paper describes the use of Differential Scanning Calorimetry (DSC) to evaluate the impact of varying mix ratios of bio-oil (pyrolysis oil) and bio-diesel on the oxidation stability and on some cold flow properties of resulting blends. The bio-oils employed were produced from the semi-continuous Auger pyrolysis of pine pellets and the batch pyrolysis of pine chips. The bio-diesel studied was obtained from poultry fat. The conditions used to prepare the bio-oil/bio-diesel blends as well as some of the fuel properties of these blends are reported. The experimental results suggest that the addition of bio-oil improves the oxidation stability of the resulting blends and modifies the crystallization behavior of unsaturated compounds. Upon the addition of bio-oil an increase in the oxidation onset temperature, as determined by DSC, was observed. The increase in bio-diesel oxidation stability is likely to be due to the presence of hindered phenols abundant in bio-oils. A relatively small reduction in DSC characteristic temperatures which are associated with cold flow properties was also observed but can likely be explained by a dilution effect. (c) 2010 Elsevier Ltd. All rights reserved.

Drug-polymer interaction between glucosamine sulfate and alginate nanoparticles: FTIR, DSC and dielectric spectroscopy studies

NASA Astrophysics Data System (ADS)

El-Houssiny, A. S.; Ward, A. A.; Mostafa, D. M.; Abd-El-Messieh, S. L.; Abdel-Nour, K. N.; Darwish, M. M.; Khalil, W. A.

2016-06-01

This work involves the preparation and characterization of alginate nanoparticles (Alg NPs) as a new transdermal carrier for site particular transport of glucosamine sulfate (GS). The GS-Alg NPs were examined through transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and dielectric spectroscopy. GS-Alg NPs was efficiently prepared via ionic gelation method which generates favorable conditions for the entrapment of hydrophilic drugs. The TEM studies revealed that GS-Alg NPs are discrete and have spherical shapes. FTIR studies showed a spectral change of the characteristic absorptions bands of Alg NPs after encapsulation with GS because of the amine groups of GS and the carboxylic acid groups of Alg. The DSC data showed changes in the thermal behavior of GS-Alg NPs after the addition of GS indicating signs of main chemical interaction among the drug (GS) and the polymer (Alg). The absence of the drug melting endothermic peak within the DSC thermogram of GS-Alg NPs indicating that GS is molecularly dispersed in the NPs and not crystallize. From the dielectric study, it was found modifications within the dielectric loss (ɛ″) and conductivity (σ) values after the addition of GS. The ɛ″ and σ values of Alg NPs decreased after the addition of GS which indicated the successful encapsulation of GS within Alg NPs. Furthermore, the dielectric study indicated an increase of the activation energy and the relaxation time for the first process in the GS-Alg NPs as compared to Alg NPs. Consequently, the existing observations indicated an initiation of electrostatic interaction among the amine group of GS and carboxyl group of Alg indicating the successful encapsulation of GS inside Alg NPs which could provide favorable circumstance for the encapsulation of GS for topical management.

Melting temperature and enthalpy variations of phase change materials (PCMs): a differential scanning calorimetry (DSC) analysis

NASA Astrophysics Data System (ADS)

Sun, Xiaoqin; Lee, Kyoung Ok; Medina, Mario A.; Chu, Youhong; Li, Chuanchang

2018-06-01

Differential scanning calorimetry (DSC) analysis is a standard thermal analysis technique used to determine the phase transition temperature, enthalpy, heat of fusion, specific heat and activation energy of phase change materials (PCMs). To determine the appropriate heating rate and sample mass, various DSC measurements were carried out using two kinds of PCMs, namely N-octadecane paraffin and calcium chloride hexahydrate. The variations in phase transition temperature, enthalpy, heat of fusion, specific heat and activation energy were observed within applicable heating rates and sample masses. It was found that the phase transition temperature range increased with increasing heating rate and sample mass; while the heat of fusion varied without any established pattern. The specific heat decreased with the increase of heating rate and sample mass. For accuracy purpose, it is recommended that for PCMs with high thermal conductivity (e.g. hydrated salt) the focus will be on heating rate rather than sample mass.

Cryomilled Aluminum with Diamantane: Thermal Characterization by DSC and Effects of Magnesium

NASA Astrophysics Data System (ADS)

Arnold, Michael Colin

Many structural applications require a material that is both lightweight and corrosion resistant, for which aluminum and its alloys may be considered for use if not for their relatively low strength. By improving strength of aluminum through the Hall-Petch mechanism, it could become a more suitable choice for many structural applications. Cryomilling is used as a production technique to strengthen aluminum by reduction of grain size to the 20-50 nm range. Although the powders produced by cryomilling are well within the nanocrystalline regime, the powders experience significant grain growth during consolidation to a solid body. Cryomilled powders have been shown to remain nanocrystalline by introducing a nano-diamond, diamantane to the grain boundaries. To better characterize the thermal stability of the cryomilled powder with diamantane, Differential Scanning Calorimetry (DSC) was used to measure the isothermal heat flow in the 0.6Tm to 0.9Tm range. A model was developed to correlate the isothermal DSC signal to a grain growth curve and grain growth parameters were elucidated by assuming variable boundary mobility with a sigmoidal form. The model revealed a tendency for boundary mobility to transition from an athermal grain growth mechanism to standard thermally activated grain growth. Grain growth parameters were compared to shed light on possible mechanisms of aluminum-diamantane involvement during grain growth. Powders and consolidated samples with very low concentrations of diamantane and with magnesium were observed by TEM, SEM and XRD, and compared both separately and together to characterize the how thermal stability is affected by diamantane concentration and the presence of magnesium.

DSC studies on gamma irradiated poly(vinylidene fluoride) applied to high gamma dose dosimetry

NASA Astrophysics Data System (ADS)

Batista, Adriana S. M.; Faria, Luiz O.

2017-11-01

Poly(vinylidene fluoride) homopolymer (PVDF) was investigated for use on high gamma dose dosimetry. Samples were irradiated with gamma doses ranging from 100 kGy to 3000 kGy. Differential scanning calorimetry (DSC) was used to construct an unambiguous relationship between the melting transition latent heat (LM) and the absorbed dose (D). DSC thermograms were taken immediately, 1, 2 and 8 months after the irradiation process revealing that the LMx D relationship presented no change for doses ranging from 100 to 2750 kGy. FTIR and UV-Vis spectroscopy data revealed the radio-induction of C˭O and C˭C bonds. These radio-induced bonds were responsible by the chain stiffening and chain oxidation, respectively. SEM microscopy demonstrates that the spherulitic large crystalline structures present in pristine PVDF are destroyed with doses as low as 100 kGy. The DRX analysis revealed that the main effect of high gamma doses in the crystalline structure of PVDF is to provoke a change from the pristine PVDF α-phase to the γ-phase. Both the ability to detect gamma doses in a large dose range and the low fading features make PVDF homopolymers good candidates to be investigated as high gamma dose dosimeters.

Advances in simultaneous DSC-FTIR microspectroscopy for rapid solid-state chemical stability studies: some dipeptide drugs as examples.

PubMed

Lin, Shan-Yang; Wang, Shun-Li

2012-04-01

The solid-state chemistry of drugs has seen growing importance in the pharmaceutical industry for the development of useful API (active pharmaceutical ingredients) of drugs and stable dosage forms. The stability of drugs in various solid dosage forms is an important issue because solid dosage forms are the most common pharmaceutical formulation in clinical use. In solid-state stability studies of drugs, an ideal accelerated method must not only be selected by different complicated methods, but must also detect the formation of degraded product. In this review article, an analytical technique combining differential scanning calorimetry and Fourier-transform infrared (DSC-FTIR) microspectroscopy simulates the accelerated stability test, and simultaneously detects the decomposed products in real time. The pharmaceutical dipeptides aspartame hemihydrate, lisinopril dihydrate, and enalapril maleate either with or without Eudragit E were used as testing examples. This one-step simultaneous DSC-FTIR technique for real-time detection of diketopiperazine (DKP) directly evidenced the dehydration process and DKP formation as an impurity common in pharmaceutical dipeptides. DKP formation in various dipeptides determined by different analytical methods had been collected and compiled. Although many analytical methods have been applied, the combined DSC-FTIR technique is an easy and fast analytical method which not only can simulate the accelerated drug stability testing but also at the same time enable to explore phase transformation as well as degradation due to thermal-related reactions. This technique offers quick and proper interpretations. Copyright © 2012 Elsevier B.V. All rights reserved.

Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas.

PubMed

Bell, L C; Does, M D; Stokes, A M; Baxter, L C; Schmainda, K M; Dueck, A C; Quarles, C C

2017-09-01

The optimal TE must be calculated to minimize the variance in CBV measurements made with DSC MR imaging. Simulations can be used to determine the influence of the TE on CBV, but they may not adequately recapitulate the in vivo heterogeneity of precontrast T2*, contrast agent kinetics, and the biophysical basis of contrast agent-induced T2* changes. The purpose of this study was to combine quantitative multiecho DSC MRI T2* time curves with error analysis in order to compute the optimal TE for a traditional single-echo acquisition. Eleven subjects with high-grade gliomas were scanned at 3T with a dual-echo DSC MR imaging sequence to quantify contrast agent-induced T2* changes in this retrospective study. Optimized TEs were calculated with propagation of error analysis for high-grade glial tumors, normal-appearing white matter, and arterial input function estimation. The optimal TE is a weighted average of the T2* values that occur as a contrast agent bolus transverses a voxel. The mean optimal TEs were 30.0 ± 7.4 ms for high-grade glial tumors, 36.3 ± 4.6 ms for normal-appearing white matter, and 11.8 ± 1.4 ms for arterial input function estimation (repeated-measures ANOVA, P < .001). Greater heterogeneity was observed in the optimal TE values for high-grade gliomas, and mean values of all 3 ROIs were statistically significant. The optimal TE for the arterial input function estimation is much shorter; this finding implies that quantitative DSC MR imaging acquisitions would benefit from multiecho acquisitions. In the case of a single-echo acquisition, the optimal TE prescribed should be 30-35 ms (without a preload) and 20-30 ms (with a standard full-dose preload). © 2017 by American Journal of Neuroradiology.

Determination of microplastic polyethylene (PE) and polypropylene (PP) in environmental samples using thermal analysis (TGA-DSC).

PubMed

Majewsky, Marius; Bitter, Hajo; Eiche, Elisabeth; Horn, Harald

2016-10-15

Microplastics are increasingly detected in the environment and the consequences on water resources and ecosystems are not clear to date. The present study provides a cost-effective and straightforward method to determine the mass concentrations of polymer types using thermal analysis. Characteristic endothermic phase transition temperatures were determined for seven plastic polymer types using TGA-DSC. Based on that, extracts from wastewater samples were analyzed. Results showed that among the studied polymers, only PE and PP could be clearly identified, while the phase transition signals of the other polymers largely overlap each other. Subsequently, calibration curves were run for PE and PP for qualitative measurements. 240 and 1540mg/m(3) of solid material (12µm to 1mm) was extracted from two wastewater effluent samples of a municipal WWTP of which 34% (81mg/m(3)) and 17% (257mg/m(3)) could be assigned to PE, while PP was not detected in any of the samples. The presented application of TGA-DSC provides a complementary or alternative method to FT-IR analyses for the determination of PE and PP in environmental samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Diatoms and Other Epibionts Associated with Olive Ridley (Lepidochelys olivacea) Sea Turtles from the Pacific Coast of Costa Rica

PubMed Central

Majewska, Roksana; Santoro, Mario; Bolaños, Federico; Chaves, Gerardo; De Stefano, Mario

2015-01-01

Although the sea turtles have long been familiar and even iconic to marine biologists, many aspects of their ecology remain unaddressed. The present study is the first of the epizoic diatom community covering the olive ridley turtle’s (Lepidochelys olivacea) carapace and the first describing diatoms living on sea turtles in general, with the primary objective of providing detailed information on turtle epibiotic associations. Samples of turtle carapace including the associated diatom biofilm and epizoic macro-fauna were collected from Ostional beach (9° 59´ 23.7´´ N 85° 41´ 52.6´´ W), Costa Rica, during the arribada event in October 2013. A complex diatom community was present in every sample. In total, 11 macro-faunal and 21 diatom taxa were recorded. Amongst diatoms, the most numerous were erect (Achnanthes spp., Tripterion spp.) and motile (Haslea sp., Navicula spp., Nitzschia spp., Proschkinia sp.) forms, followed by adnate Amphora spp., while the most common macro-faunal species was Stomatolepas elegans (Cirripedia). Diatom densities ranged from 8179 ± 750 to 27685 ± 4885 cells mm-2. Epizoic microalgae were either partly immersed or entirely encapsulated within an exopolymeric coat. The relatively low diatom species number, stable species composition and low inter-sample dissimilarities (14.4% on average) may indicate a mutualistic relationship between the epibiont and the basibiont. Dispersal of sea turtle diatoms is probably highly restricted and similar studies will help to understand both diatom diversity, evolution and biogeography, and sea turtle ecology and foraging strategies. PMID:26083535

Drug release studies from lipid nanoparticles in physiological media by a new DSC method.

PubMed

Roese, Elin; Bunjes, Heike

2017-06-28

Lipid nanoparticles are an interesting parenteral delivery system for poorly water-soluble drugs. In order to approach physiological conditions when conducting release studies from such systems the release media should preferentially contain lipophilic acceptor compartments such as lipoproteins or other colloidal lipophilic components. In practice, drug release studies under such close to physiological conditions may be complicated by the small size of lipid nanoparticles, which is in the same range as that of the potential acceptor particles. This study describes a novel differential scanning calorimetry (DSC) method for drug release measurements which works without separation of donor and acceptor particles. The technique is based on measuring the crystallization temperature of trimyristin nanoparticles by DSC. The crystallization temperature of the nanoparticles decreases proportionally with the amount of active ingredient incorporated and thus increases as a result of drug release. Liquid trimyristin nanoparticles loaded with fenofibrate, orlistat, tocopherol acetate and ubidecarenone were studied in three different release media with increasing complexity and comparability to physiological conditions: a rapeseed oil nanoemulsion, porcine serum and porcine blood. Using the new method, a correlation between release behavior and drug lipophilicity was observed: the higher the logP value of the drug, the slower the release. The extent of drug release was influenced by partition equilibrium as indicated by increased drug release in the rapeseed oil nanoemulsion compared to porcine serum and blood. Copyright © 2017 Elsevier B.V. All rights reserved.

First approximation to congenital malformation rates in embryos and hatchlings of sea turtles.

PubMed

Bárcenas-Ibarra, Annelisse; de la Cueva, Horacio; Rojas-Lleonart, Isaias; Abreu-Grobois, F Alberto; Lozano-Guzmán, Rogelio Iván; Cuevas, Eduardo; García-Gasca, Alejandra

2015-03-01

Congenital malformations in sea turtles have been considered sporadical. Research carried out in the Mexican Pacific revealed high levels of congenital malformations in the olive ridley, but little or no information is available for other species. We present results from analyses of external congenital malformations in olive ridley, green, and hawskbill sea turtles from Mexican rookeries on the Pacific coast and Gulf of Mexico. We examined 150 green and hawksbill nests and 209 olive ridley nests during the 2010 and 2012 nesting seasons, respectively. Olive ridley eggs were transferred to a hatchery and incubated in styrofoam boxes. Nests from the other two species were left in situ. Number of eggs, live and dead hatchlings, and eggs with or without embryonic development were registered. Malformation frequency was evaluated with indices of prevalence and severity. Mortality levels, prevalence and severity were higher in olive ridley than in hawksbill and green sea turtles. Sixty-three types of congenital malformations were observed in embryos, and dead or live hatchlings. Of these, 38 are new reports; 35 for wild sea turtles, three for vertebrates. Thirty-one types were found in hawksbill, 23 in green, and 59 in olive ridley. The head region showed a higher number of malformation types. Malformation levels in the olive ridley were higher than previously reported. Olive ridleys seem more prone to the occurrence of congenital malformations than the other two species. Whether the observed malformation levels are normal or represent a health problem cannot be currently ascertained without long-term assessments. © 2015 Wiley Periodicals, Inc.

Effect of critical molecular weight of PEO in epoxy/EPO blends as characterized by advanced DSC and solid-state NMR

NASA Astrophysics Data System (ADS)

Wang, Xiaoliang; Lu, Shoudong; Sun, Pingchuan; Xue, Gi

2013-03-01

The differential scanning calorimetry (DSC) and solid state NMR have been used to systematically study the length scale of the miscibility and local dynamics of the epoxy resin/poly(ethylene oxide) (ER/PEO) blends with different PEO molecular weight. By DSC, we found that the diffusion behavior of PEO with different Mw is an important factor in controlling these behaviors upon curing. We further employed two-dimensional 13C-{1H}PISEMA NMR experiment to elucidate the possible weak interaction and detailed local dynamics in ER/PEO blends. The CH2O group of PEO forms hydrogen bond with hydroxyl proton of cured-ER ether group, and its local dynamics frozen by such interaction. Our finding indicates that molecular weight (Mw) of PEO is a crucial factor in controlling the miscibility, chain dynamics and hydrogen bonding interaction in these blends.

DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

NASA Astrophysics Data System (ADS)

Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

2016-07-01

The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

Olive Ridley Sea Turtle Hatching Success as a Function of the Microbial Abundance in Nest Sand at Ostional, Costa Rica

PubMed Central

Bézy, Vanessa S.; Valverde, Roldán A.; Plante, Craig J.

2015-01-01

Several studies have suggested that significant embryo mortality is caused by microbes, while high microbial loads are generated by the decomposition of eggs broken by later nesting turtles. This occurs commonly when nesting density is high, especially during mass nesting events (arribadas). However, no previous research has directly quantified microbial abundance and the associated effects on sea turtle hatching success at a nesting beach. The aim of this study was to test the hypothesis that the microbial abundance in olive ridley sea turtle nest sand affects the hatching success at Ostional, Costa Rica. We applied experimental treatments to alter the microbial abundance within the sand into which nests were relocated. We monitored temperature, oxygen, and organic matter content throughout the incubation period and quantified the microbial abundance within the nest sand using a quantitative polymerase chain reaction (qPCR) molecular analysis. The most successful treatment in increasing hatching success was the removal and replacement of nest sand. We found a negative correlation between hatching success and fungal abundance (fungal 18S rRNA gene copies g-1 nest sand). Of secondary importance in determining hatching success was the abundance of bacteria (bacterial 16S rRNA gene copies g-1 g-1 nest sand). Our data are consistent with the hypothesis that high microbial activity is responsible for the lower hatching success observed at Ostional beach. Furthermore, the underlying mechanism appears to be the deprivation of oxygen and exposure to higher temperatures resulting from microbial decomposition in the nest. PMID:25714355

Physical transformation of niclosamide solvates in pharmaceutical suspensions determined by DSC and TG analysis.

PubMed

de Villiers, M M; Mahlatji, M D; Malan, S F; van Tonder, E C; Liebenberg, W

2004-07-01

This study reports the preparation of four niclosamide solvates and the determination of the stability of the crystal forms in different suspension vehicles by DSC and TG analysis. Thermal analysis showed that the niclosamide solvates were extremely unstable in a PVP-vehicle and rapidly changed to monohydrated crystals. A suspension in propylene glycol was more stable and TG analysis showed that crystal transformation was less rapid. In this vehicle, the crystals transformed to the anhydrate, rather than the monohydrate, since the vehicle was non-aqueous. The TEG-hemisolvate was the most stable in suspension and offered the best possibility of commercial exploitation.

Clam Shell Dredging in Lakes Pontchartrain and Maurepas, Louisiana. Volume 1. Final Environmental Impact Statement and Appendixes

DTIC Science & Technology

1987-11-01

favorable nesting habitats. Viosca (1961) felt ridleys preferred to nest in the loose sand of the Chandeleur Islands rather than the compacted...Ceorgia. Southeastern Wildlife Services, Inc. Athens, Ca. 24 p. In Rabalais and Rabalais 1980. Hughes, G.R. 1972. The olive ridley sea-turtle...that may be potentially impacted by the proposed activity are the Kemp’s (Atlantic) ridley sea turtle, Lepidochelys kempi, which is endangered, and

Structure and Phase Transitions of Poly (Hexamethylene p,p'-Bibenzoate) as Studied by DSC and Real-Time SAXS/WAXS Employing Synchrotron Radiation

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

Katerska, B.; Krasteva, M.; Perez, E.

2007-04-23

Real-time small and wide angle X-ray scattering as well as DSC studies were carried out in order to analyzes the structure and phase transitions of liquid crystalline thermotropic poly(methylene p,p' bibenzoat)

DSC, X-ray and FTIR studies of a gemfibrozil/dimethyl-β-cyclodextrin inclusion complex produced by co-grinding.

PubMed

Aigner, Z; Berkesi, O; Farkas, G; Szabó-Révész, P

2012-01-05

The steps of formation of an inclusion complex produced by the co-grinding of gemfibrozil and dimethyl-β-cyclodextrin were investigated by differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD) and Fourier transform infrared (FTIR) spectroscopy with curve-fitting analysis. The endothermic peak at 59.25°C reflecting the melting of gemfibrozil progressively disappeared from the DSC curves of the products on increase of the duration of co-grinding. The crystallinity of the samples too gradually decreased, and after 35min of co-grinding the product was totally amorphous. Up to this co-grinding time, XRPD and FTIR investigations indicated a linear correlation between the cyclodextrin complexation and the co-grinding time. After co-grinding for 30min, the ratio of complex formation did not increase. These studies demonstrated that co-grinding is a suitable method for the complexation of gemfibrozil with dimethyl-β-cyclodextrin. XRPD analysis revealed the amorphous state of the gemfibrozil-dimethyl-β-cyclodextrin product. FTIR spectroscopy with curve-fitting analysis may be useful as a semiquantitative analytical method for discriminating the molecular and amorphous states of gemfibrozil. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of the Diagnostic Accuracy of DSC- and Dynamic Contrast-Enhanced MRI in the Preoperative Grading of Astrocytomas.

PubMed

Nguyen, T B; Cron, G O; Perdrizet, K; Bezzina, K; Torres, C H; Chakraborty, S; Woulfe, J; Jansen, G H; Sinclair, J; Thornhill, R E; Foottit, C; Zanette, B; Cameron, I G

2015-11-01

Dynamic contrast-enhanced MR imaging parameters can be biased by poor measurement of the vascular input function. We have compared the diagnostic accuracy of dynamic contrast-enhanced MR imaging by using a phase-derived vascular input function and "bookend" T1 measurements with DSC MR imaging for preoperative grading of astrocytomas. This prospective study included 48 patients with a new pathologic diagnosis of an astrocytoma. Preoperative MR imaging was performed at 3T, which included 2 injections of 5-mL gadobutrol for dynamic contrast-enhanced and DSC MR imaging. During dynamic contrast-enhanced MR imaging, both magnitude and phase images were acquired to estimate plasma volume obtained from phase-derived vascular input function (Vp_Φ) and volume transfer constant obtained from phase-derived vascular input function (K(trans)_Φ) as well as plasma volume obtained from magnitude-derived vascular input function (Vp_SI) and volume transfer constant obtained from magnitude-derived vascular input function (K(trans)_SI). From DSC MR imaging, corrected relative CBV was computed. Four ROIs were placed over the solid part of the tumor, and the highest value among the ROIs was recorded. A Mann-Whitney U test was used to test for difference between grades. Diagnostic accuracy was assessed by using receiver operating characteristic analysis. Vp_ Φ and K(trans)_Φ values were lower for grade II compared with grade III astrocytomas (P < .05). Vp_SI and K(trans)_SI were not significantly different between grade II and grade III astrocytomas (P = .08-0.15). Relative CBV and dynamic contrast-enhanced MR imaging parameters except for K(trans)_SI were lower for grade III compared with grade IV (P ≤ .05). In differentiating low- and high-grade astrocytomas, we found no statistically significant difference in diagnostic accuracy between relative CBV and dynamic contrast-enhanced MR imaging parameters. In the preoperative grading of astrocytomas, the diagnostic accuracy of dynamic

Environmental Assessment for ’Community Beach Center’ (RCS 04-899 & 05-350)

DTIC Science & Technology

2005-12-19

with the olive ridley , the Kemp’s ridley (Lepidocheyls kempi) is the smallest of the sea turtle species. Kemp’s ridleys are considered to be the most...Alternative C is the preferred alternative. No Action Alternative: Under the No Action Altemative, a Community Beach Center would not be constructed at...funding permits, expand the facility along the lines of Alternative A. This is preferred alternative. Figure 6 illustrates the site plan for the

Investigation of Phase Mixing in Amorphous Solid Dispersions of AMG 517 in HPMC-AS Using DSC, Solid-State NMR, and Solution Calorimetry.

PubMed

Calahan, Julie L; Azali, Stephanie C; Munson, Eric J; Nagapudi, Karthik

2015-11-02

Intimate phase mixing between the drug and the polymer is considered a prerequisite to achieve good physical stability for amorphous solid dispersions. In this article, spray dried amorphous dispersions (ASDs) of AMG 517 and HPMC-as were studied by differential scanning calorimetry (DSC), solid-state NMR (SSNMR), and solution calorimetry. DSC analysis showed a weakly asymmetric (ΔTg ≈ 13.5) system with a single glass transition for blends of different compositions indicating phase mixing. The Tg-composition data was modeled using the BKCV equation to accommodate the observed negative deviation from ideality. Proton spin-lattice relaxation times in the laboratory and rotating frames ((1)H T1 and T1ρ), as measured by SSNMR, were consistent with the observation that the components of the dispersion were in intimate contact over a 10-20 nm length scale. Based on the heat of mixing calculated from solution calorimetry and the entropy of mixing calculated from the Flory-Huggins theory, the free energy of mixing was calculated. The free energy of mixing was found to be positive for all ASDs, indicating that the drug and polymer are thermodynamically predisposed to phase separation at 25 °C. This suggests that miscibility measured by DSC and SSNMR is achieved kinetically as the result of intimate mixing between drug and polymer during the spray drying process. This kinetic phase mixing is responsible for the physical stability of the ASD.

Multivariate analysis of DSC-XRD simultaneous measurement data: a study of multistage crystalline structure changes in a linear poly(ethylene imine) thin film.

PubMed

Kakuda, Hiroyuki; Okada, Tetsuo; Otsuka, Makoto; Katsumoto, Yukiteru; Hasegawa, Takeshi

2009-01-01

A multivariate analytical technique has been applied to the analysis of simultaneous measurement data from differential scanning calorimetry (DSC) and X-ray diffraction (XRD) in order to study thermal changes in crystalline structure of a linear poly(ethylene imine) (LPEI) film. A large number of XRD patterns generated from the simultaneous measurements were subjected to an augmented alternative least-squares (ALS) regression analysis, and the XRD patterns were readily decomposed into chemically independent XRD patterns and their thermal profiles were also obtained at the same time. The decomposed XRD patterns and the profiles were useful in discussing the minute peaks in the DSC. The analytical results revealed the following changes of polymorphisms in detail: An LPEI film prepared by casting an aqueous solution was composed of sesquihydrate and hemihydrate crystals. The sesquihydrate one was lost at an early stage of heating, and the film changed into an amorphous state. Once the sesquihydrate was lost by heating, it was not recovered even when it was cooled back to room temperature. When the sample was heated again, structural changes were found between the hemihydrate and the amorphous components. In this manner, the simultaneous DSC-XRD measurements combined with ALS analysis proved to be powerful for obtaining a better understanding of the thermally induced changes of the crystalline structure in a polymer film.

Use of thermal analysis coupled with differential scanning calorimetry, quadrupole mass spectrometry and infrared spectroscopy (TG-DSC-QMS-FTIR) to monitor chemical properties and thermal stability of fulvic and humic acids.

PubMed

Boguta, Patrycja; Sokołowska, Zofia; Skic, Kamil

2017-01-01

Thermogravimetry-coupled with differential scanning calorimetry, quadrupole mass spectrometry, and Fourier-transform infrared spectroscopy (TG-DSC-QMS-FTIR)-was applied to monitor the thermal stability (in an N2 pyrolytic atmosphere) and chemical properties of natural polymers, fulvic (FA) and humic acids (HA), isolated from chemically different soils. Three temperature ranges, R1, 40-220°C; R2, 220-430°C; and R3, 430-650°C, were distinguished from the DSC data, related to the main thermal processes of different structures (including transformations without weight loss). Weight loss (ΔM) estimated from TG curves at the above temperature intervals revealed distinct differences within the samples in the content of physically adsorbed water (at R1), volatile and labile functional groups (at R2) as well as recalcitrant and refractory structures (at R3). QMS and FTIR modules enabled the chemical identification (by masses and by functional groups, respectively) of gaseous species evolved during thermal decomposition at R1, R2 and R3. Variability in shape, area and temperature of TG, DSC, QMS and FTIR peaks revealed differences in thermal stability and chemical structure of the samples between the FAs and HAs fractions of different origin. The statistical analysis showed that the parameters calculated from QMS (areas of m/z = 16, 17, 18, 44), DSC (MaxDSC) and TG (ΔM) at R1, R2 and R3 correlated with selected chemical properties of the samples, such as N, O and COOH content as well as E2/E6 and E2/E4 indexes. This indicated a high potential for the coupled method to monitor the chemical changes of humic substances. A new humification parameter, HTD, based on simple calculations of weight loss at specific temperature intervals proved to be a good alternative to indexes obtained from other methods. The above findings showed that the TG-DSC-QMS-FTIR coupled technique can represent a useful tool for the comprehensive assessment of FAs and HAs properties related to their

Use of thermal analysis coupled with differential scanning calorimetry, quadrupole mass spectrometry and infrared spectroscopy (TG-DSC-QMS-FTIR) to monitor chemical properties and thermal stability of fulvic and humic acids

PubMed Central

Sokołowska, Zofia; Skic, Kamil

2017-01-01

Thermogravimetry–coupled with differential scanning calorimetry, quadrupole mass spectrometry, and Fourier-transform infrared spectroscopy (TG-DSC-QMS-FTIR)–was applied to monitor the thermal stability (in an N2 pyrolytic atmosphere) and chemical properties of natural polymers, fulvic (FA) and humic acids (HA), isolated from chemically different soils. Three temperature ranges, R1, 40–220°C; R2, 220–430°C; and R3, 430–650°C, were distinguished from the DSC data, related to the main thermal processes of different structures (including transformations without weight loss). Weight loss (ΔM) estimated from TG curves at the above temperature intervals revealed distinct differences within the samples in the content of physically adsorbed water (at R1), volatile and labile functional groups (at R2) as well as recalcitrant and refractory structures (at R3). QMS and FTIR modules enabled the chemical identification (by masses and by functional groups, respectively) of gaseous species evolved during thermal decomposition at R1, R2 and R3. Variability in shape, area and temperature of TG, DSC, QMS and FTIR peaks revealed differences in thermal stability and chemical structure of the samples between the FAs and HAs fractions of different origin. The statistical analysis showed that the parameters calculated from QMS (areas of m/z = 16, 17, 18, 44), DSC (MaxDSC) and TG (ΔM) at R1, R2 and R3 correlated with selected chemical properties of the samples, such as N, O and COOH content as well as E2/E6 and E2/E4 indexes. This indicated a high potential for the coupled method to monitor the chemical changes of humic substances. A new humification parameter, HTD, based on simple calculations of weight loss at specific temperature intervals proved to be a good alternative to indexes obtained from other methods. The above findings showed that the TG-DSC-QMS-FTIR coupled technique can represent a useful tool for the comprehensive assessment of FAs and HAs properties related

Environmental Assessment for Destin 4th of July Fireworks and Beach Cleanup

DTIC Science & Technology

2008-06-01

as nesting along the gulf coast of Florida but there have been no known nestings on Eglin beaches. Along with the olive ridley , the Kemp’s ridley ...associated infauna, while adult diet consists primarily of crabs. Kemp’s ridleys are not known to nest on Eglin’s Beaches. Piping Plover The piping...frontal dune and scrub habitat within the coastal dune ecosystem on SRI, preferring sand- covered slopes with patches of grasses and herbs, and their diet

δ13C and d15N in the endangered Kemp’s ridley sea turtle Lepidochelys kempii after the Deepwater Horizon oil spill

USGS Publications Warehouse

Reich, Kimberly J.; López-Castro, Melania C.; Shaver, Donna J.; Iseton, Claire; Hart, Kristen M.; Hooper, Michael J.; Schmitt, Christopher J.

2017-01-01

The Deepwater Horizon explosion in April 2010 and subsequent oil spill released 3.19 × 106 barrels (5.07 × 108 L) of MC252 crude oil into important foraging areas of the endangered Kemp’s ridley sea turtle Lepidochelys kempii (Lk) in the northern Gulf of Mexico (GoM). We measured δ13C and δ15N in scute biopsy samples from 33 Lk nesting in Texas during 2010–-12. Of these, 27 were equipped with satellite transmitters and were tracked to traditional foraging areas in the northern GoM after the spill. Differences in δ13C between the oldest and newest scute layers from 2010 nesters were not significantly different, but δ13C in the newest layers from 2011 and 2012 nesters was significantly lower compared to 2010. δ15N differences were not statistically significant. Collectively, the stable isotope and tracking data indicate that the lower δ13C values reflect the incorporation of oil rather than changes in diet or foraging area. Discriminant analysis indicated that 51.5% of the turtles sampled had isotope signatures indicating oil exposure. Growth of the Lk population slowed in the years following the spill. The involvement of oil exposure in recent population trends is unknown, but long-term effects may not be evident for many years. Our results indicate that C isotope signatures in scutes may be useful biomarkers of sea turtle exposure to oil.

Dynamics of Polymorphic Transformations in Palm Oil, Palm Stearin and Palm Kernel Oil Characterized by Coupled Powder XRD-DSC.

PubMed

Zaliha, Omar; Elina, Hishamuddin; Sivaruby, Kanagaratnam; Norizzah, Abd Rashid; Marangoni, Alejandro G

2018-06-01

The in situ polymorphic forms and thermal transitions of refined, bleached and deodorized palm oil (RBDPO), palm stearin (RBDPS) and palm kernel oil (RBDPKO) were investigated using coupled X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Results indicated that the DSC onset crystallisation temperature of RBDPO was at 22.6°C, with a single reflection at 4.2Å started to appear from 23.4 to 17.1°C, and were followed by two prominent exothermic peaks at 20.1°C and 8.5°C respectively. Further cooling to -40°C leads to the further formation of a β'polymorph. Upon heating, a of β'→βtransformation was observed between 32.1 to 40.8°C, before the sample was completely melted at 43.0°C. The crystallization onset temperature of RBDPS was 44.1°C, with the appearance of the α polymorph at the same temperature as the appearance of the first sharp DSC exothermic peak. This quickly changed from α→β´ in the range 25 to 21.7°C, along with the formation of a small β peak at -40°C. Upon heating, a small XRD peak for the β polymorph was observed between 32.2 to 36.0°C, becoming a mixture of (β´+ β) between 44.0 to 52.5°C. Only the β polymorph survived further heating to 59.8°C. For RBDPKO, the crystallization onset temperature was 11.6°C, with the formation of a single sharp exothermic peak at 6.5°C corresponding to the β' polymorphic form until the temperature reached -40°C. No transformation of the polymorphic form was observed during the melting process of RBDPKO, before being completely melted at 33.2°C. This work has demonstrated the detailed dynamics of polymorphic transformations of PKO and PS, two commercially important hardstocks used widely by industry and will contribute to a greater understanding of their crystallization and melting dynamics.

Kinetics of Thermal Decomposition of Ammonium Perchlorate by TG/DSC-MS-FTIR

NASA Astrophysics Data System (ADS)

Zhu, Yan-Li; Huang, Hao; Ren, Hui; Jiao, Qing-Jie

2014-01-01

The method of thermogravimetry/differential scanning calorimetry-mass spectrometry-Fourier transform infrared (TG/DSC-MS-FTIR) simultaneous analysis has been used to study thermal decomposition of ammonium perchlorate (AP). The processing of nonisothermal data at various heating rates was performed using NETZSCH Thermokinetics. The MS-FTIR spectra showed that N2O and NO2 were the main gaseous products of the thermal decomposition of AP, and there was a competition between the formation reaction of N2O and that of NO2 during the process with an iso-concentration point of N2O and NO2. The dependence of the activation energy calculated by Friedman's iso-conversional method on the degree of conversion indicated that the AP decomposition process can be divided into three stages, which are autocatalytic, low-temperature diffusion and high-temperature, stable-phase reaction. The corresponding kinetic parameters were determined by multivariate nonlinear regression and the mechanism of the AP decomposition process was proposed.

Molecular oxidative stress markers in olive ridley turtles (Lepidochelys olivacea) and their relation to metal concentrations in wild populations.

PubMed

Cortés-Gómez, Adriana A; Morcillo, Patricia; Guardiola, Francisco A; Espinosa, Cristobal; Esteban, María A; Cuesta, Alberto; Girondot, Marc; Romero, Diego

2018-02-01

Due to their longevity and extensive migration areas, marine turtles are able to accumulate diverse contaminants over many years and as a consequence they represent an interesting bioindicator species for marine ecosystem pollution. Metals provoke toxicological effects in many aquatic animal species, but marine turtles have been under-investigated in this area. Thus, we have determined the presence of certain inorganic elements (As, Cd, Cu, Ni, Pb, Se and Zn) in olive ridley turtles (Lepidochelys olivacea) and related them to metallothionein (MT), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) transcription and/or enzymatic activities. Gene expression of sod, cat and gr was found to be higher in blood than liver or kidney but most of the significant relationships were found in liver, not only for gene expression but also for enzyme activities. This must be related to the role the liver has as the first filter organ. Several positive relationships of sod, cat and gr gene expression in the different tissues were found in this population, as well as very high Cd concentrations. This could mean that these turtles are adapting to the metals-production of ROS and damage through a high transcription of these antioxidants. Multiple positive relationships with GR seem to be part of its compensatory effect due to the decrease of SOD production against the high and chronic exposure to certain xenobiotics. CAT, on the other hand, seems not to be used much, and glutathione detoxification of H 2 O 2 may be more important in this species. Finally, despite the very high Cd concentrations found in this population, no significant relationship was found in any tissue with metallothionein gene expression. These results, along with very high Cd concentrations and a negative relationship with Cu, lead us to consider some kind of disruption in mt gene expression in these turtles. Copyright © 2017 Elsevier Ltd. All rights reserved.

DSC and EPR investigations on effects of cholesterol component on molecular interactions between paclitaxel and phospholipid within lipid bilayer membrane.

PubMed

Zhao, Lingyun; Feng, Si-Shen; Kocherginsky, Nikolai; Kostetski, Iouri

2007-06-29

Differential scanning calorimetry (DSC) and electron paramagnetic resonance spectroscopy (EPR) were applied to investigate effects of cholesterol component on molecular interactions between paclitaxel, which is one of the best antineoplastic agents found from nature, and dipalmitoylphosphatidylcholine (DPPC) within lipid bilayer vesicles (liposomes), which could also be used as a model cell membrane. DSC analysis showed that incorporation of paclitaxel into the DPPC bilayer causes a reduction in the cooperativity of bilayer phase transition, leading to a looser and more flexible bilayer structure. Including cholesterol component in the DPPC/paclitaxel mixed bilayer can facilitate the molecular interaction between paclitaxel and lipid and make the tertiary system more stable. EPR analysis demonstrated that both of paclitaxel and cholesterol have fluidization effect on the DPPC bilayer membranes although cholesterol has more significant effect than paclitaxel does. The reduction kinetics of nitroxides by ascorbic acid showed that paclitaxel can inhibit the reaction by blocking the diffusion of either the ascorbic acid or nitroxide molecules since the reaction is tested to be a first order one. Cholesterol can remarkably increase the reduction reaction speed. This research may provide useful information for optimizing liposomal formulation of the drug as well as for understanding the pharmacology of paclitaxel.

Use and Complications of Operative Control of Arterial Inflow in Combat Casualties with Traumatic Lower-extremity Amputations Caused by Improvised Explosive Devices

DTIC Science & Technology

2013-08-01

explosive devices Henrietta Poon, MRCS, Jonathan J. Morrison, MRCS, Jon C. Clasper, DPhil, FRCSEd(Orth), Mark J. Midwinter, MD, FRCS, and Jan O. Jansen...the IP group, compared with the EP, although this does not achieve statistical significance, likely owing to a lack of power within the study. The war

Diagnostic Values of DCE-MRI and DSC-MRI for Differentiation Between High-grade and Low-grade Gliomas: A Comprehensive Meta-analysis.

PubMed

Liang, Jianye; Liu, Dexiang; Gao, Peng; Zhang, Dong; Chen, Hanwei; Shi, Changzheng; Luo, Liangping

2018-03-01

This study aimed to collect the studies on the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and dynamic susceptibility contrast MRI (DSC-MRI) in differentiating the grades of gliomas, and evaluate the diagnostic performances of relevant quantitative parameters in glioma grading. We systematically searched studies on the diagnosis of gliomas with DCE-MRI or DSC-MRI in Medline, PubMed, China National Knowledge Infrastructure database, Cochrane Library, and Embase published between January 2005 and December 2016. Standardized mean differences and 95% confidence intervals were calculated for volume transfer coefficient (K trans ), volume fraction of extravascular extracellular space (V e ), rate constant of backflux (K ep ), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) using Review Manager 5.2 software. Sensitivity, specificity, area under the curve (AUC), and Begg test were calculated by Stata 12.0. Twenty-two studies with available outcome data were included in the analysis. The standardized mean difference of K trans values between high-grade glioma and low-grade glioma were 1.18 (0.91, 1.45); V e values were 1.43 (1.06, 1.80); K ep values were 0.65 (-0.05, 1.36); rCBV values were 1.44 (1.08, 1.81); and rCBF values were 1.17 (0.68, 1.67), respectively. The results were all significant statistically (P < .05) except K ep values (P = .07), and high-grade glioma had higher K trans , V e , rCBV, and rCBF values than low-grade glioma. AUC values of K trans , V e , rCBV, and rCBF were 0.90, 0.88, 0.93, and 0.73, respectively; rCBV had the largest AUC among the four parameters (P < .05). Both DCE-MRI and DSC-MRI are reliable techniques in differentiating the grades of gliomas, and rCBV was found to be the most sensitive one. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Post-Wildfire Potential for Carbon and Nitrogen Sequestration in the Southwestern United States in Restored Ephemeral and Intermittent Stream Channels

NASA Astrophysics Data System (ADS)

Callegary, J. B.; Norman, L.; Eastoe, C. J.; Sankey, J. B.; Youberg, A.

2016-12-01

The Kemp's ridley sea turtle (Lepidochelys kempii) is the most endangered sea turtle in the world, largely due to the limited geographic range of its nesting habitat. In the U.S., the majority of nesting occurs along Padre Island National Seashore (PAIS) in Texas. There has been limited research regarding the connection between beach geomorphology and Kemp's ridley nesting patterns, but studies concerning other sea turtle species suggest that certain beach geomorphology variables, such as beach slope and width, influence nest site selection. This research investigates terrestrial habitat variability of the Kemp's ridley sea turtle and quantifies the connection between beach geomorphology and Kemp's ridley nest site selection on PAIS and South Padre Island, Texas. Airborne topographic lidar data collected annually along the Texas coast from 2009 through 2012 was utilized to extract beach geomorphology characteristics, such as beach slope and width, dune height, and surface roughness, among others. The coordinates of observed Kemp's ridley nests from corresponding years were integrated with the aforementioned data in statistical models, which analyzed the influence of both general trends in geomorphology and individual morphologic variables on nest site selection. This research identified the terrestrial habitat variability of the Kemp's ridley and quantified the range of geomorphic characteristics of nesting beaches. Initial results indicate that dune width, beach width, and wind speed are significant variables in relation to nest presence, using an alpha of 0.1. Higher wind speeds and narrower beaches and foredunes favor nest presence. The average nest elevation is 1.13 m above mean sea level, which corresponds to the area directly below the potential vegetation line, and the majority of nesting occurs between the elevations of 0.68 m and 1.4 m above mean sea level. The results of this study include new information regarding Kemp's ridley beach habitat and its

Young "Science Ambassadors" Raise the Profile of Science

ERIC Educational Resources Information Center

Ridley, Katie

2014-01-01

Katie Ridley, science coordinator at St. Gregory's Catholic Primary School, Liverpool, UK, states that the inspiration for "science ambassadors" came after embarking on the Primary Science Quality Mark programme at their school. Ridley realized that science was just not recognised as such by the children, they talked about scientific…

Multicultural Approaches in Psychotherapy: A Rejoinder

ERIC Educational Resources Information Center

Owen, Jesse; Leach, Mark M.; Wampold, Bruce; Rodolfa, Emil

2011-01-01

In this rejoinder, the authors address several issues raised by R. L. Worthington and F. R. Dillon (2011) and C. R. Ridley and M. Shaw-Ridley (2011) regarding (a) the measurement of multicultural competencies (MCCs), (b) sampling considerations in multicultural research, and (c) the conceptual frame of multicultural psychotherapy research. The…

Expression of aromatase in the embryonic brain of the olive ridley sea turtle (Lepidochelys olivacea), and the effect of bisphenol-A in sexually differentiated embryos.

PubMed

Gómez-Picos, Patsy; Sifuentes-Romero, Itzel; Merchant-Larios, Horacio; Hernández-Cornejo, Rubí; Díaz-Hernández, Verónica; García-Gasca, Alejandra

2014-01-01

Brain aromatase participates in several biological processes, such as regulation of the reproductive-endocrine axis, memory, stress, sexual differentiation of the nervous system, male sexual behavior, and brain repair. Here we report the isolation and expression of brain aromatase in olive ridley sea turtle (Lepidochelys olivacea) embryos incubated at male- and female-promoting temperatures (MPT and FPT, respectively), at the thermosensitive period (TSP) and the sex-differentiated period. Also, aromatase expression was assessed in differentiated embryos exposed to bisphenol-A (BPA) during the TSP. BPA is a monomer of polycarbonate plastics and is considered an endocrine-disrupting compound. Normal aromatase expression was measured in both forebrain and hindbrain, showing higher expression levels in the forebrain of differentiated embryos at both incubation temperatures. Although no significant differences were detected in the hindbrain, expression was slightly higher at MPT. BPA did not affect aromatase expression neither in forebrains or hindbrains from embryos incubated at MPT, whereas at FPT an inverted U-shape curve was observed in forebrains with significant differences at lower concentrations, whereas in hindbrains a non-significant increment was observed at higher concentrations. Our data indicate that both incubation temperature and developmental stage are critical factors affecting aromatase expression in the forebrain. Because of the timing and location of aromatase expression in the brain, we suggest that brain aromatase may participate in the imprinting of sexual trends related to reproduction and sexual behavior at the onset of sex differentiation, and BPA exposure may impair aromatase function in the female forebrain.

Diclofenac Salts. V. Examples of Polymorphism among Diclofenac Salts with Alkyl-hydroxy Amines Studied by DSC and HSM

PubMed Central

Fini, Adamo; Cavallari, Cristina; Ospitali, Francesca

2010-01-01

Nine diclofenac salts prepared with alkyl-hydroxy amines were analyzed for their properties to form polymorphs by DSC and HSM techniques. Thermograms of the forms prepared from water or acetone are different in most cases, suggesting frequent examples of polymorphism among these salts. Polymorph transition can be better highlighted when analysis is carried out by thermo-microscopy, which in most cases made it possible to observe the processes of melting of the metastable form and re-crystallization of the stable one. Solubility values were qualitatively related to the crystal structure of the salts and the molecular structure of the cation. PMID:27721347

Examining the Doctoral Viva: Perspectives from a Sample of UK Academics

ERIC Educational Resources Information Center

Poole, Brian

2015-01-01

The doctoral viva voce examination has existed in Britain since the PhD (or DPhil) was introduced at Oxford University almost a hundred years ago. However, despite some recent research studies, it seems that the viva remains somewhat under-researched and that viva voce examinations continue to take place according to largely unchanged and…

Dynamic susceptibility contrast (DSC) perfusion MRI in differential diagnosis between radionecrosis and neoangiogenesis in cerebral metastases using rCBV, rCBF and K2.

PubMed

Muto, Mario; Frauenfelder, Giulia; Senese, Rossana; Zeccolini, Fabio; Schena, Emiliano; Giurazza, Francesco; Jäger, Hans Rolf

2018-07-01

Distinction between treatment-related changes and tumour recurrence in patients who have received radiation treatment for brain metastases can be difficult on conventional MRI. In this study, we investigated the ability of dynamic susceptibility contrast (DSC) perfusion in differentiating necrotic changes from pathological angiogenesis and compared measurements of relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF) and K2, using a dedicated software. Twenty-nine patients with secondary brain tumors were included in this retrospective study and underwent DSC perfusion MRI with a 3-month follow-up imaging after chemo- or radiation-therapy. Region-of-interests were drawn around the contrast enhancing lesions and measurements of rCBV, rCBF and K2 were performed in all patients. Based on subsequent histological examination or clinico-radiological follow-up, the cohort was divided in two groups: recurrent disease and stable disease. Differences between the two groups were analyzed using the Student's t test. Sensitivity, specificity and diagnostic accuracy of rCBV measurements were analyzed considering three different cut-off values. Between patients with and without disease, only rCBV and rCBF values were significant (p < 0.05). The only cut-off value giving the best diagnostic accuracy of 100% was rCBV = 2.1 (sensitivity = 100%; specificity = 100%). Patients with tumor recurrence showed a higher mean value of rCBV (mean = 4.28, standard deviation = 2.09) than patients with necrotic-related changes (mean = 0.77, standard deviation = 0.44). DSC-MRI appears a clinically useful method to differentiate between tumor recurrence, tumor necrosis and pseudoprogression in patients treated for cerebral metastases. Relative CBV using a cut-off value of 2.1 proved to be the most accurate and reliable parameter.

Inclusion complexes of cypermethrin and permethrin with monochlorotriazinyl-beta-cyclodextrin: A combined spectroscopy, TG/DSC and DFT study

NASA Astrophysics Data System (ADS)

Yao, Qi; You, Bin; Zhou, Shuli; Chen, Meng; Wang, Yujiao; Li, Wei

2014-01-01

The suitable size hydrophobic cavity and monochlorotriazinyl group as a reactive anchor make MCT-β-CD to be widely used in fabric finishing. In this paper, the inclusion complexes of monochlorotriazinyl-beta-cyclodextrin (MCT-β-CD) with cypermethrin (CYPERM) and permethrin (PERM) are synthesized and analyzed by TG/DSC, FT-IR and Raman spectroscopy. TG/DSC reveals that the decomposed temperatures of inclusion complexes are lower by 25-30 °C than that of physical mixtures. DFT calculations in conjunction with FT-IR and Raman spectral analyses are used to study the structures of MCT-β-CD and their inclusion complexes. Four isomers of trisubstituted MCT-β-CD are designed and DFT calculations reveal that 1,3,5-trisubstituted MCT-β-CD has the lowest energy and can be considered as main component of MCT-β-CD. The ground-state geometries, vibrational wavenumbers, IR and Raman intensities of MCT-β-CD and their inclusion complexes were calculated at B3LYP/6-31G (d) level of theory. Upon examining the optimized geometry of inclusion complex, we find that the CYPERM and PERM are inserted into the toroid of MCT-β-CD from the larger opening. The band at 1646 cm-1 in IR and at 1668 cm-1 in Raman spectrum reveals that monochloroazinyl group of MCT-β-CD exists in ketone form but not in anion form. The noticeable IR and Raman shift of phenyl reveals that these two benzene rings of CYPERM and PERM stays inside the cavity of MCT-β-CD and has weak interaction with MCT-β-CD. This spectroscopy conclusion is consistent with theoretical predicted structure.

Shopping for Old and New Wine: A Response

ERIC Educational Resources Information Center

Murdock, Nancy L.; Nilsson, Johanna E.; Duan, Changming

2012-01-01

With this rejoinder, we address some of the concerns and questions raised by Ridley and Mollen (2012) and Hill (2012). Specially, we reflect upon Ridley and Mollen's commentary about whether the three theories in this major contribution can be deemed emergent or whether they are simply old thought in new packages. We also address Hill's question…

Time Keeps on Ticking: The Experience of Clinical Judgment

ERIC Educational Resources Information Center

Spengler, Paul M.; White, Michael J.; Aegisdottir, Stefania; Maugherman, Alan S.

2009-01-01

The reactions by Ridley and Shaw-Ridley (EJ832451) and Lichtenberg (EJ832452) to the authors' meta-analysis on the effects of experience on judgment accuracy add positively to what is hoped will become an ever more focused discourse on this most basic question: How can mental health clinical decision making be improved? In this rejoinder, the…

A Serious Game for Massive Training and Assessment of French Soldiers Involved in Forward Combat Casualty Care (3D-SC1): Development and Deployment.

PubMed

Pasquier, Pierre; Mérat, Stéphane; Malgras, Brice; Petit, Ludovic; Queran, Xavier; Bay, Christian; Boutonnet, Mathieu; Jault, Patrick; Ausset, Sylvain; Auroy, Yves; Perez, Jean Paul; Tesnière, Antoine; Pons, François; Mignon, Alexandre

2016-05-18

The French Military Health Service has standardized its military prehospital care policy in a ''Sauvetage au Combat'' (SC) program (Forward Combat Casualty Care). A major part of the SC training program relies on simulations, which are challenging and costly when dealing with more than 80,000 soldiers. In 2014, the French Military Health Service decided to develop and deploy 3D-SC1, a serious game (SG) intended to train and assess soldiers managing the early steps of SC. The purpose of this paper is to describe the creation and production of 3D-SC1 and to present its deployment. A group of 10 experts and the Paris Descartes University Medical Simulation Department spin-off, Medusims, coproduced 3D-SC1. Medusims are virtual medical experiences using 3D real-time videogame technology (creation of an environment and avatars in different scenarios) designed for educational purposes (training and assessment) to simulate medical situations. These virtual situations have been created based on real cases and tested on mannequins by experts. Trainees are asked to manage specific situations according to best practices recommended by SC, and receive a score and a personalized feedback regarding their performance. The scenario simulated in the SG is an attack on a patrol of 3 soldiers with an improvised explosive device explosion as a result of which one soldier dies, one soldier is slightly stunned, and the third soldier experiences a leg amputation and other injuries. This scenario was first tested with mannequins in military simulation centers, before being transformed into a virtual 3D real-time scenario using a multi-support, multi-operating system platform, Unity. Processes of gamification and scoring were applied, with 2 levels of difficulty. A personalized debriefing was integrated at the end of the simulations. The design and production of the SG took 9 months. The deployment, performed in 3 months, has reached 84 of 96 (88%) French Army units, with a total of 818

Once a physicist: Tony Hey

NASA Astrophysics Data System (ADS)

2008-01-01

Why did you originally choose to study physics? I was really interested in science at school, and I also read a couple of fascinating popular-science books about quantum mechanics and special relativity. My interest in these topics made me decide to study physics at Oxford University. Straight after I graduated in 1967 I did a theoretical-physics DPhil, also at Oxford.

Comparison of two DSC-based methods to predict drug-polymer solubility.

PubMed

Rask, Malte Bille; Knopp, Matthias Manne; Olesen, Niels Erik; Holm, René; Rades, Thomas

2018-04-05

The aim of the present study was to compare two DSC-based methods to predict drug-polymer solubility (melting point depression method and recrystallization method) and propose a guideline for selecting the most suitable method based on physicochemical properties of both the drug and the polymer. Using the two methods, the solubilities of celecoxib, indomethacin, carbamazepine, and ritonavir in polyvinylpyrrolidone, hydroxypropyl methylcellulose, and Soluplus® were determined at elevated temperatures and extrapolated to room temperature using the Flory-Huggins model. For the melting point depression method, it was observed that a well-defined drug melting point was required in order to predict drug-polymer solubility, since the method is based on the depression of the melting point as a function of polymer content. In contrast to previous findings, it was possible to measure melting point depression up to 20 °C below the glass transition temperature (T g ) of the polymer for some systems. Nevertheless, in general it was possible to obtain solubility measurements at lower temperatures using polymers with a low T g . Finally, for the recrystallization method it was found that the experimental composition dependence of the T g must be differentiable for compositions ranging from 50 to 90% drug (w/w) so that one T g corresponds to only one composition. Based on these findings, a guideline for selecting the most suitable thermal method to predict drug-polymer solubility based on the physicochemical properties of the drug and polymer is suggested in the form of a decision tree. Copyright © 2018 Elsevier B.V. All rights reserved.

Elaboration, structural, spectroscopy, DSC investigations and Hirshfeld surface analysis of a one-dimensional self-assembled organic-inorganic hybrid compound

NASA Astrophysics Data System (ADS)

Mesbeh, Radhia; Hamdi, Besma; Zouari, Ridha

2017-01-01

The new organic-inorganic hybrid of the formula [H2mela]Cu2Cl6, where mela = 1,3,5-triazine-2,4,6-triamine, has been synthesized by the reaction of 1,3,5-triazine-2,4,6-triamine and copper(II) chloride dihydrate in the presence of hydrochloric acid. This compound has been determined by X-ray diffraction analysis and characterized by FT-IR, Raman, NMR characterization, differential scanning calorimetric (DSC) analysis, dielectric measurements and Hirshfeld surface. 1,3,5-triazinidium-2,4,6-triamine hexachlorodicuprate(II) crystallizes in the monoclinic system with space group P21/c. The final refinement of the structure of the program led to the reliability factors unweighted R1 = 3.53% and weighted WR2 = 8.87%. The observed internal C3sbnd N31sbnd C1 and C3sbnd N23sbnd C2 angle (121.5 and 121.4°) at protanated N-atom are significantly greater the other ring angle C1sbnd N12sbnd C2 (117.1°). The titled compound crystallizes as an organic-inorganic one-dimensional (1D) structure. The crystal structure was stabilized by two types of hydrogen bonding Nsbnd H⋯Cl and Nsbnd H⋯N. The infrared spectra was recorded in the 4000-400 cm-1 frequency region and the Raman spectra was recorded in the external region of the anionic sublattice vibration 4000-50 cm-1 at room temperature. Solid-state 13C and 63Cu MAS-NMR spectroscopies are in agreement with the X-ray structure. The differential scanning calorimetric (DSC) show the presence of a structural phase transition of the title compound at 338 K. Hirshfeld surface analyses for visually analyzing intermolecular interactions in crystal structures employing molecular surface contours and 2D fingerprint plots have been used to examine molecular shapes.

Transformative Advances in DDDAS with Application to Space Weather Monitoring

DTIC Science & Technology

2015-10-01

subsystems, including power and communications subsystems. In addition, a study of photovoltaic power generation constraints due to spacecraft solar...estimation. Automatica, 23:775–778, 1987. [61] D. Y. Lee, J. W. Cutler, J. Mancewicz, and A. J. Ridley. Maximizing photovoltaic power generation of a space...Maximizing photovoltaic power generation of a space-dart configured satellite. Acta Astronautica, 111:283–299, 2015. A. V. Morozov, A. J. Ridley, D. S

Validation of a T1 and T2* leakage correction method based on multi-echo DSC-MRI using MION as a reference standard

PubMed Central

Stokes, Ashley M.; Semmineh, Natenael; Quarles, C. Chad

2015-01-01

Purpose A combined biophysical- and pharmacokinetic-based method is proposed to separate, quantify, and correct for both T1 and T2* leakage effects using dual-echo DSC acquisitions to provide more accurate hemodynamic measures, as validated by a reference intravascular contrast agent (CA). Methods Dual-echo DSC-MRI data were acquired in two rodent glioma models. The T1 leakage effects were removed and also quantified in order to subsequently correct for the remaining T2* leakage effects. Pharmacokinetic, biophysical, and combined biophysical and pharmacokinetic models were used to obtain corrected cerebral blood volume (CBV) and cerebral blood flow (CBF), and these were compared with CBV and CBF from an intravascular CA. Results T1-corrected CBV was significantly overestimated compared to MION CBV, while T1+T2*-correction yielded CBV values closer to the reference values. The pharmacokinetic and simplified biophysical methods showed similar results and underestimated CBV in tumors exhibiting strong T2* leakage effects. The combined method was effective for correcting T1 and T2* leakage effects across tumor types. Conclusions Correcting for both T1 and T2* leakage effects yielded more accurate measures of CBV. The combined correction method yields more reliable CBV measures than either correction method alone, but for certain brain tumor types (e.g., gliomas) the simplified biophysical method may provide a robust and computationally efficient alternative. PMID:26362714

Azide derivatized anticancer agents of Vitamin K 3: X-ray structural, DSC, resonance spectral and API studies

NASA Astrophysics Data System (ADS)

Badave, Kirti; Patil, Yogesh; Gonnade, Rajesh; Srinivas, Darbha; Dasgupta, Rajan; Khan, Ayesha; Rane, Sandhya

2011-12-01

Compound 1 [1-imino (acetyl hydrazino)-Vitamin K 3], displays valence tautomerically related electronic isomers as Form I and Form II. Form I exhibits 2D packing fragment with 1D ribbon chains of N-H⋯O hydrogen bonds and shows EPR silent features. While Form II is EPR active and exhibits biradical nature with double quantum transitions at g = 2.0040. 1H NMR of compound 2, [1-imino (hydrazino carboxylate)-Vitamin K 3] and Form II exhibit π delocalization via resonance assisted H-bonding [RAHB] effect compared to Form I. Molecular interactions in Form I and II are visualized by DSC. The electronic structures of compounds 1 and 2 have been correlated to their API values by measuring anticancer activities, mitochondrial potentials and DNA shearing patterns. Form II and compound 2 indicate mitochondria mediated apoptosis (˜75% cell death) while Form I causes 35% cell death.

Use of DSC and DMA to Study Rubber Crystallization as a Possible Cause for a Tear in a Neoprene Glove Used in a Space Shuttle Pressurized Astronaut Suit

NASA Technical Reports Server (NTRS)

Wingard, Doug

2009-01-01

The Advanced Crew Escape Suit (ACES) is a pressurized suit normally worn by astronauts during launch and landing phases of Space Shuttle operations. In 2008, a large tear (0.5 -1 in. long, between the pinky and ring finger) in the ACES left-hand glove made of neoprene latex rubber was found during training for Shuttle flight STS-124. An investigation to help determine the cause(s) of the glove tear was headed by the NASA Johnson Space Center (JSC) in Houston, Texas. Efforts at JSC to reproduce the actual glove tear pattern by cutting/tearing or rupturing were unsuccessful. Chemical and material property data from JSC such as GC-MS, FTIR, DSC and TGA mostly showed little differences between samples from the torn and control gloves. One possible cause for the glove tear could be a wedding ring/band worn by a male astronaut. Even with a smooth edge, such a ring could scratch the material and initiate the tear observed in the left-hand glove. A decision was later made by JSC to not allow the wearing of such a ring during training or actual flight. Another possible cause for the ACES glove tear is crystallinity induced by strain in the neoprene rubber over a long period of time and use. Neoprene is one several elastomeric materials known to be susceptible to crystallization, and such a process is accelerated with exposure of the material to cold temperatures plus strain. When the temperature is lowered below room temperature, researchers have shown that neoprene crystallization may be maintained at temperatures as high as 45-50 F, with a maximum crystallization rate near 20-25 F (1). A convenient conditioning temperature for inducing neoprene crystallization is a typical freezer that is held near 0 F. For work at the NASA Marshall Space Flight Center (MSFC), samples were cut from several areas/locations (pinky/ring finger crotch, index finger and palm) on each of two pairs of unstrained ACES gloves for DSC and DMA thermal analysis testing. The samples were conditioned

Poly(fumaric-co-sebacic anhydride). A degradation study as evaluated by FTIR, DSC, GPC and X-ray diffraction.

PubMed

Santos, C A; Freedman, B D; Leach, K J; Press, D L; Scarpulla, M; Mathiowitz, E

1999-06-28

The degradation of three poly(fumaric-co-sebacic anhydride) [P(FA:SA)] copolymers is examined in a composition of microspheres made by the hot melt encapsulation process. The emergence of low molecular weight oligomers occurs during degradation of the copolymer microspheres, as evidenced by a variety of characterization methods. Characterization was conducted to determine the extent of degradation of the polyanhydride microspheres using Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and X-ray diffraction. It is demonstrated that degradation of P(FA:SA) is greatly accelerated at basic pH, yet there is little difference between degradation in neutral and acidic buffers. A good correlation exists between the results of each characterization method, which allows a better understanding of the degradation process and the resulting formation of low molecular weight oligomers in poly(fumaric-co-sebacic anhydride).

Some considerations on the vibrational environment of the DSC-DCMIX1 experiment onboard ISS

NASA Astrophysics Data System (ADS)

Jurado, R.; Gavaldà, Jna.; Simón, M. J.; Pallarés, J.; Laverón-Simavilla, A.; Ruiz, X.; Shevtsova, V.

2016-12-01

The present work attempts to characterize the accelerometric environment of the DSC-DCMIX1 thermodiffusion experiment carried out in the International Space Station, from November 7th 2011 until January 16th 2012. Quasi-steady and vibrational/transient data coming from MAMS and SAMS2 sensors have been downloaded from the database of the PIMS NASA website. To be as exhaustive as possible, simultaneous digital signals coming from different SAMS2 sensors located in the Destiny and Columbus modules have also been considered. In order to detect orbital adjustments, dockings, undockings, as well as, quiescent periods, when the experiment runs were active, we have used the quasi-steady eight hours averaged (XA, YA and ZA) acceleration functions as well as the eight hours RMS ones. To determine the spectral contents of the different signals the Thomson multitaper and Welch methods have been used. On the other hand, to suppress the high levels of noise always existing in the raw SAMS2 signals, denoising techniques have been preferred for comparative reboostings considerations. Finally, the RMS values for specific 1/3 octave frequency bands showed that the International Space Station vibratory limit requirements have not been totally accomplished during both quiescent periods and strong disturbances, specially in the low frequency range.

Automatic twin vessel recrystallizer. Effective purification of acetaminophen by successive automatic recrystallization and absolute determination of purity by DSC.

PubMed

Nara, Osamu

2011-01-24

I describe an interchangeable twin vessel (J, N) automatic glass recrystallizer that eliminates the time-consuming recovery and recycling of crystals for repeated recrystallization. The sample goes in the dissolution vessel J containing a magnetic stir-bar K; J is clamped to the upper joint H of recrystallizer body D. Empty crystallization vessel N is clamped to the lower joint M. Pure solvent is delivered to the dissolution vessel and the crystallization vessel via the head of the condenser A. Crystallization vessel is heated (P). The dissolution reservoir is stirred and heated by the solvent vapor (F). Continuous outflow of filtrate E out of J keeps N at a stable boiling temperature. This results in efficient dissolution, evaporation and separation of pure crystals Q. Pure solvent in the dissolution reservoir is recovered by suction. Empty dissolution and crystallization vessels are detached. Stirrer magnet is transferred to the crystallization vessel and the role of the vessels are then reversed. Evacuating mother liquor out of the upper twin vessel, the apparatus unit is ready for the next automatic recrystallization by refilling twin vessels with pure solvent. We show successive automatic recrystallization of acetaminophen from diethyl ether obtaining acetaminophen of higher melting temperatures than USP and JP reference standards by 8× automatic recrystallization, 96% yield at each stage. Also, I demonstrate a novel approach to the determination of absolute purity by combining the successive automatic recrystallization with differential scanning calorimetry (DSC) measurement requiring no reference standards. This involves the measurement of the criterial melting temperature T(0) corresponding to the 100% pure material and quantitative ΔT in DSC based on the van't Hoff law of melting point depression. The purity of six commercial acetaminophen samples and reference standards and an eight times recrystallized product evaluated were 98.8 mol%, 97.9 mol%, 99

Thermal characterization and model free kinetics of aged epoxies and foams using TGA and DSC methods.

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

Cordaro, Joseph Gabriel; Kruizenga, Alan Michael; Nissen, April

2013-10-01

Two classes of materials, poly(methylene diphenyl diisocyanate) or PMDI foam, and cross-linked epoxy resins, were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), to help understand the effects of aging and %E2%80%9Cbake-out%E2%80%9D. The materials were evaluated for mass loss and the onset of decomposition. In some experiments, volatile materials released during heating were analyzed via mass spectroscopy. In all, over twenty materials were evaluated to compare the mass loss and onset temperature for decomposition. Model free kinetic (MFK) measurements, acquired using variable heating rate TGA experiments, were used to calculate the apparent activation energy of thermal decomposition.more » From these compiled data the effects of aging, bake-out, and sample history on the thermal stability of materials were compared. No significant differences between aged and unaged materials were detected. Bake-out did slightly affect the onset temperature of decomposition but only at the highest bake-out temperatures. Finally, some recommendations for future handling are made.« less

Bidirectional Contrast agent leakage correction of dynamic susceptibility contrast (DSC)-MRI improves cerebral blood volume estimation and survival prediction in recurrent glioblastoma treated with bevacizumab.

PubMed

Leu, Kevin; Boxerman, Jerrold L; Lai, Albert; Nghiemphu, Phioanh L; Pope, Whitney B; Cloughesy, Timothy F; Ellingson, Benjamin M

2016-11-01

To evaluate a leakage correction algorithm for T 1 and T2* artifacts arising from contrast agent extravasation in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) that accounts for bidirectional contrast agent flux and compare relative cerebral blood volume (CBV) estimates and overall survival (OS) stratification from this model to those made with the unidirectional and uncorrected models in patients with recurrent glioblastoma (GBM). We determined median rCBV within contrast-enhancing tumor before and after bevacizumab treatment in patients (75 scans on 1.5T, 19 scans on 3.0T) with recurrent GBM without leakage correction and with application of the unidirectional and bidirectional leakage correction algorithms to determine whether rCBV stratifies OS. Decreased post-bevacizumab rCBV from baseline using the bidirectional leakage correction algorithm significantly correlated with longer OS (Cox, P = 0.01), whereas rCBV change using the unidirectional model (P = 0.43) or the uncorrected rCBV values (P = 0.28) did not. Estimates of rCBV computed with the two leakage correction algorithms differed on average by 14.9%. Accounting for T 1 and T2* leakage contamination in DSC-MRI using a two-compartment, bidirectional rather than unidirectional exchange model might improve post-bevacizumab survival stratification in patients with recurrent GBM. J. Magn. Reson. Imaging 2016;44:1229-1237. © 2016 International Society for Magnetic Resonance in Medicine.

Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

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

Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.

2013-12-03

For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent massmore » loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.« less

Development and validation of an open source quantification tool for DSC-MRI studies.

PubMed

Gordaliza, P M; Mateos-Pérez, J M; Montesinos, P; Guzmán-de-Villoria, J A; Desco, M; Vaquero, J J

2015-03-01

This work presents the development of an open source tool for the quantification of dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion studies. The development of this tool is motivated by the lack of open source tools implemented on open platforms to allow external developers to implement their own quantification methods easily and without the need of paying for a development license. This quantification tool was developed as a plugin for the ImageJ image analysis platform using the Java programming language. A modular approach was used in the implementation of the components, in such a way that the addition of new methods can be done without breaking any of the existing functionalities. For the validation process, images from seven patients with brain tumors were acquired and quantified with the presented tool and with a widely used clinical software package. The resulting perfusion parameters were then compared. Perfusion parameters and the corresponding parametric images were obtained. When no gamma-fitting is used, an excellent agreement with the tool used as a gold-standard was obtained (R(2)>0.8 and values are within 95% CI limits in Bland-Altman plots). An open source tool that performs quantification of perfusion studies using magnetic resonance imaging has been developed and validated using a clinical software package. It works as an ImageJ plugin and the source code has been published with an open source license. Copyright © 2015 Elsevier Ltd. All rights reserved.

Brevetoxin exposure in sea turtles in south Texas (USA) during Karenia brevis red tide.

PubMed

Walker, Jennifer Shelby; Shaver, Donna J; Stacy, Brian A; Flewelling, Leanne J; Broadwater, Margaret H; Wang, Zhihong

2018-01-31

Five green (Chelonia mydas) and 11 Kemp's ridley (Lepidochelys kempii) sea turtles found dead, or that died soon after stranding, on the southern Texas (USA) coast during 2 Karenia brevis blooms (October 2015, September-October 2016) were tested for exposure to brevetoxins (PbTx). Tissues (liver, kidney) and digesta (stomach and intestinal contents) were analyzed by ELISA. Three green turtles found alive during the 2015 event and 2 Kemp's ridley turtles found alive during the 2016 event exhibited signs of PbTx exposure, including lethargy and/or convulsions of the head and neck. PbTx were detected in 1 or more tissues or digesta in all 16 stranded turtles. Detected PbTx concentrations ranged from 2 to >2000 ng g-1. Necropsy examination and results of PbTx analysis indicated that 10 of the Kemp's ridleys and 2 of the green turtles died from brevetoxicosis via ingestion. This is the first documentation of sea turtle mortality in Texas attributed to brevetoxicosis.

Thermal characterization of Titan's tholins by simultaneous TG-MS, DTA, DSC analysis

NASA Astrophysics Data System (ADS)

Nna-Mvondo, Delphine; de la Fuente, José L.; Ruiz-Bermejo, Marta; Khare, Bishun; McKay, Christopher P.

2013-09-01

Three samples of Titan's tholins synthesized in laboratory under simulated Titan's conditions and presenting different degrees of exposure to ambient atmosphere have been used to study in detail their thermal behavior using thermogravimetry coupled with a mass spectrometer (TG-MS), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The degradation of Titan's tholins under inert atmosphere follows a three-step consecutive decomposition: a drying stage (>150 °C) where moisture is desorbed, this stage indicated the high hydrophilicity of the tholins; a second stage, the main pyrolysis stage (150-575 °C) where endothermic decomposition begins releasing mainly ammonia, HCN, acetonitrile, and methane over a broad temperature range. Few other hydrocarbon fragments such as ethylene and propane are released but no cyclic molecules, aliphatic or aromatic, are observed. The last stage (>575 °C) is the carbonization of the material leading to a non-crystalline graphitic residue. The thermal degradation under oxygen atmosphere shows the same stages as in argon, with a shift of the thermogravimetric peaks toward lower temperatures indicating a lower thermal stability. The last stage in this case is an oxidative combustion of the char residue. This research concludes that even if Titan tholins, subjected to air contamination for few minutes to several years (varying with the storage conditions) transform to produce different C/N and C/O ratios and thermal stabilities, they undergo the same thermal degradation phases and products. This suggests that the studied three tholins have a similar main chemical structure which does not alter by the air exposure. We discuss on the possible nature of this structure.

Kinetics of thermolysis of lanthanum nitrate with hexamethylenetetramine: Crystal structure, TG-DSC, impact and friction sensitivity studies, Part-96

NASA Astrophysics Data System (ADS)

Nibha; Baranwal, B. P.; Singh, Gurdip; Singh, C. P.; Daniliuc, Constantin G.; Soni, P. K.; Nath, Yogeshwar

2014-11-01

The development of high energetic materials includes process ability and the ability to attain insensitive munitions (IM). This paper investigates the preparation of lanthanum metal nitrate complex of hexamethylenetetramine in water at room temperature. This complex of molecular formulae [La (NO3)2(H2O)6] (2HMTA) (NO3-) (H2O) was characterized by X-ray crystallography. Thermal decomposition was investigated using TG, TG-DSC and ignition delay measurements. Kinetic analysis of isothermal TG data has been investigated using model fitting methods as well as model free isoconversional methods. The sensitivity measurements towards mechanical destructive stimuli such as impact and friction were carried out and the complex was found to be insensitive. In order to identify the end product of thermolysis, X-ray diffraction patterns of end product was carried out which proves the formation of La2O3.

FTIR, XRD and DSC studies of nanochitosan, cellulose acetate and polyethylene glycol blend ultrafiltration membranes.

PubMed

Vinodhini, P Angelin; K, Sangeetha; Thandapani, Gomathi; P N, Sudha; Jayachandran, Venkatesan; Sukumaran, Anil

2017-11-01

In the present work, a series of novel nanochitosan/cellulose acetate/polyethylene glycol (NCS/CA/PEG) blend flat sheet membranes were fabricated in different ratios (1:1:1, 1:1:2, 2:1:1, 2:1:2, 1:2:1, 2:2:1) in a polar solvent of N,N'-dimethylformamide (DMF) using the most popular phase inversion method. Nanochitosan was prepared by the ionotropic gelation method and its average particle size has been analyzed using Dynamic Light Scattering (DLS) method. The effect of blending of the three polymers was investigated using FTIR and XRD studies. FTIR results confirmed the formation of well-blended membranes and the XRD analysis revealed enhanced amorphous nature of the membrane ratio 2:1:2. DSC study was conducted to find out the thermal behavior of the blend membranes and the results clearly indicated good thermal stability and single glass transition temperature (T g ) of all the prepared membranes. Asymmetric nature and rough surface morphology was confirmed using SEM analysis. From the results it was evident that the blending of the polymers with higher concentration of nanochitosan can alter the nature of the resulting membranes to a greater extent and thus amorphous membranes were obtained with good miscibility and compatibility. Copyright © 2017 Elsevier B.V. All rights reserved.

Crystallization kinetics of orthorhombic paracetamol from supercooled melts studied by non-isothermal DSC.

PubMed

Nikolakakis, Ioannis; Kachrimanis, Kyriakos

2017-02-01

A simple and highly reproducible procedure was established for the study of orthorhombic paracetamol crystallization kinetics, comprising melting, quench-cooling of the melt and scanning the formed glass by DSC at different heating rates. Results were analyzed on the basis of the mean as well as local values of the Avrami exponent, n, the energy of activation, as well as the Šesták-Berggren two-parameter autocatalytic kinetic model. The mean value of the Avrami kinetic exponent, n, ranged between 3 and 5, indicating deviation from the nucleation and growth mechanism underlying the Johnson-Mehl, Avrami-Kolmogorov (JMAK) model. To verify the extent of the deviation, local values of the Avrami exponent as a function of the volume fraction transformed were calculated. Inspection of the local exponent values indicates that the crystallization mechanism changes over time, possibly reflecting the uncertainty of crystallization onset, instability of nucleation due to an autocatalytic effect of the crystalline phase, and growth anisotropy due to impingement of spherulites in the last stages of crystallization. The apparent energy of activation, E a , has a rather low mean value, close to 81 kJ/mol, which is in agreement with the observed instability of glassy-state paracetamol. Isoconversional methods revealed that E a tends to decrease with the volume fraction transformed, possibly because of the different energy demands of nucleation and growth. The exponents of the Šesták-Berggren two-parameter model showed that the crystallized fraction influences the process, confirming the complexity of the crystallization mechanism.

NonLinear Effects in Photorefractive Crystals

DTIC Science & Technology

1988-01-01

effect (a non - reciprocal rotation of the polarisation axis in a crystal subjected to a magnetic field) in 1845 [331 but failed to find a comparable...the transmission geometry for the crystal orientation in Fig 5. Take the two incident beams polarised in the y direction to maximize the electrooptic... beams polarised in z. There will be little or no coupling in these regions and therefore the overall gain is reduced. John Heaton’s D.Phil. thesis

Why some Jehovah's Witnesses accept blood and conscientiously reject official Watchtower Society blood policy

PubMed Central

Elder, L.

2000-01-01

In their responses to Dr Osamu Muramoto (hereafter Muramoto) Watchtower Society (hereafter WTS) spokesmen David Malyon and Donald Ridley (hereafter Malyon and Ridley),1–3 deny many of the criticisms levelled against the WTS by Muramoto.4–6 In this paper I argue as a Jehovah's Witness (hereafter JW) and on behalf of the members of AJWRB that there is no biblical basis for the WTS's partial ban on blood and that this dissenting theological view should be made clear to all JW patients who reject blood on religious grounds. Such patients should be guaranteed confidentiality should they accept whole blood or components that are banned by the WTS. I argue against Malyon's and Ridley's claim that WTS policy allows freedom of conscience to individual JWs and that it is non-coercive and non-punitive in dealing with conscientious dissent and I challenge the notion that there is monolithic support of the WTS blood policy among those who identify themselves as JWs and carry the WTS "advance directive". Key Words: Blood transfusion • Jehovah's Witnesses • Watchtower • autonomy PMID:11055042

Structures and phase transitions in a new ferroelectric -- pyridinium chlorochromate -- studied by X-ray diffraction, DSC and dielectric methods.

PubMed

Małuszyńska, Hanna; Czarnecki, Piotr; Czarnecka, Anna; Pająk, Zdzisław

2012-04-01

Pyridinium chlorochromate, [C(5)H(5)NH](+)[ClCrO(3)](-) (hereafter referred to as PyClCrO(3)), was studied by X-ray diffraction, differential scanning calorimetry (DSC) and dielectric methods. Studies reveal three reversible phase transitions at 346, 316 and 170 K with the following phase sequence: R ̅3m (I) → R3m (II) → Cm (III) → Cc (IV), c' = 2c. PyClCrO(3) is the first pyridinium salt in which all four phases have been successfully characterized by a single-crystal X-ray diffraction method. Structural results together with dielectric and calorimetric studies allow the classification of the two intermediate phases (II) and (III) as ferroelectric with the Curie point at 346 K, and the lowest phase (IV) as most probably ferroelectric. The ferroelectric hysteresis loop was observed only in phase (III). The high ionic conductivity hindered its observation in phase (II).

Preliminary Analysis of the Social and Scientific Impact of the UAEM-ININ M.Sc. and D.Sc. Graduate Programme in Medical Physics

NASA Astrophysics Data System (ADS)

Mitsoura, Eleni; Isaac-Olive, Keila; Torres-Garcia, Eugenio; Camacho-Lopez, Miguel Angel; Hardy-Perez, Alberto

2010-12-01

Sponsored by the International Atomic Energy Agency (IAEA) in 1994, the Instituto Nacional de Investigaciones Nucleares (ININ) started in Mexico a teaching and training programme (Diplomado) in Radiotherapy Medical Physics. Based on this experience, the Universidad Autónoma del Estado de México (UAEM) and the Instituto Nacional de Investigaciones Nucleares (ININ) launched two years later, the first Graduate Programme in Science (M.Sc. and D.Sc.), specialised in Medical Physics in Mexico. A preliminary analysis of the social and scientific impact of the UAEM-ININ Programme is presented in this work based on the achievements attained, regarding the number of graduated Medical Physicists, their geographic and academic origin, their current professional activities and the number of scientific publications produced as a result of the thesis, as well as their citations.

Unspecific membrane protein-lipid recognition: combination of AFM imaging, force spectroscopy, DSC and FRET measurements.

PubMed

Borrell, Jordi H; Montero, M Teresa; Morros, Antoni; Domènech, Òscar

2015-11-01

In this work, we will describe in quantitative terms the unspecific recognition between lactose permease (LacY) of Escherichia coli, a polytopic model membrane protein, and one of the main components of the inner membrane of this bacterium. Supported lipid bilayers of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) (3:1, mol/mol) in the presence of Ca(2+) display lateral phase segregation that can be distinguished by atomic force microscopy (AFM) as well as force spectroscopy. LacY shows preference for fluid (Lα) phases when it is reconstituted in POPE : POPG (3:1, mol/mol) proteoliposomes at a lipid-to-protein ratio of 40. When the lipid-to-protein ratio is decreased down to 0.5, two domains can be distinguished by AFM. While the upper domain is formed by self-segregated units of LacY, the lower domain is constituted only by phospholipids in gel (Lβ) phase. On the one hand, classical differential scanning calorimetry (DSC) measurements evidenced the segregation of a population of phospholipids and point to the existence of a boundary region at the lipid-protein interface. On the other hand, Förster Resonance Energy Transfer (FRET) measurements in solution evidenced that POPE is selectively recognized by LacY. A binary pseudophase diagram of POPE : POPG built from AFM observations enables to calculate the composition of the fluid phase where LacY is inserted. These results are consistent with a model where POPE constitutes the main component of the lipid-LacY interface segregated from the fluid bulk phase where POPG predominates. Copyright © 2015 John Wiley & Sons, Ltd.

Novel organic NLO material bis(N-phenylbiguanidium(1+)) oxalate - A combined X-ray diffraction, DSC and vibrational spectroscopic study of its unique polymorphism

NASA Astrophysics Data System (ADS)

Matulková, Irena; Císařová, Ivana; Vaněk, Přemysl; Němec, Petr; Němec, Ivan

2017-01-01

Three polymorphic modifications of bis(N-phenylbiguanidium(1+)) oxalate are reported, and their characterization is discussed in this paper. The non-centrosymmetric bis(N-phenylbiguanidium(1+)) oxalate (I), which was obtained from an aqueous solution at 313 K, belongs to the monoclinic space group Cc (a = 6.2560(2) Å, b = 18.6920(3) Å, c = 18.2980(5) Å, β = 96.249(1)°, V = 2127.0(1) Å3, Z = 4, R = 0.0314 for 4738 observed reflections). The centrosymmetric bis(N-phenylbiguanidium(1+)) oxalate (II) was obtained from an aqueous solution at 298 K and belongs to the monoclinic space group P21/n (a = 6.1335(3) Å, b = 11.7862(6) Å, c = 14.5962(8) Å, β = 95.728(2)°, V = 1049.90(9) Å3, Z = 4, R = 0.0420 for 2396 observed reflections). The cooling of the centrosymmetric phase (II) leads to the formation of bis(N-phenylbiguanidium(1+)) oxalate (III) (a = 6.1083(2) Å, b = 11.3178(5) Å, c = 14.9947(5) Å, β = 93.151(2)°, V = 1035.05(8) Å3, Z = 4, R = 0.0345 for 2367 observed reflections and a temperature of 110 K), which also belongs to the monoclinic space group P21/n. The crystal structures of the three characterized phases are generally based on layers of isolated N-phenylbiguanidium(1 +) cations separated by oxalate anions and interconnected with them by several types of N-H...O hydrogen bonds. The observed phases generally differ not only in their crystal packing but also in the lengths and characteristics of their hydrogen bonds. The thermal behaviour of the prepared compounds was studied using the DSC method in the temperature range from 90 K up to a temperature near the melting point of each crystal. The bis(N-phenylbiguanidium(1+)) oxalate (II) crystals exhibit weak reversible thermal effects on the DSC curve at 147 K (heating run). Further investigation of this effect, which was assigned to the isostructural phase transformation, was performed using FTIR, Raman spectroscopy and X-ray diffraction analysis in a wide temperature range.

Examination of fluorination effect on physical properties of saturated long-chain alcohols by DSC and Langmuir monolayer.

PubMed

Nakahara, Hiromichi; Nakamura, Shohei; Okahashi, Yoshinori; Kitaguchi, Daisuke; Kawabata, Noritake; Sakamoto, Seiichi; Shibata, Osamu

2013-02-01

Partially fluorinated long-chain alcohols have been newly synthesized from a radical reaction, which is followed by a reductive reaction. The fluorinated alcohols have been investigated by differential scanning calorimetry (DSC) and compression isotherms in a Langmuir monolayer state. Their melting points increase with an increase in chain length due to elongation of methylene groups. However, the melting points for the alcohols containing shorter fluorinated moieties are lower than those for the typical hydrogenated fatty alcohols. Using the Langmuir monolayer technique, surface pressure (π)-molecular area (A) and surface potential (ΔV)-A isotherms of monolayers of the fluorinated alcohols have been measured in the temperature range from 281.2 to 303.2K. In addition, a compressibility modulus (Cs(-1)) is calculated from the π-A isotherms. Four kinds of the alcohol monolayers show a phase transition (π(eq)) from a disordered to an ordered state upon lateral compression. The π(eq) values increase linearly with increasing temperatures. A slope of π(eq) against temperature for the alcohols with shorter fluorocarbons is unexpectedly larger than that for the corresponding fatty alcohols. Generally, fluorinated amphiphiles have a greater thermal stability (or resistance), which is a characteristic of highly fluorinated or perfluorinated compounds. Herein, however, the alcohols containing perfluorobutylated and perfluorohexylated chains show the irregular thermal behavior in both the solid and monolayer states. Copyright © 2012 Elsevier B.V. All rights reserved.

Environmental effects of dredging: Alternative dredging equipment and operational methods to minimize sea turtle mortalities. Technical notes

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

Dickerson, D.D.; Nelson, D.A.

1990-12-01

Five species of sea turtles occur along the United States coastlines and are listed as threatened or endangered. The loggerhead sea turtle (Caretta caretta) is listed as threatened, while the Kemp`s ridley (Lepidochelys kenipi), the hawksbill (Eretmochelys imbricata), and the leatherback (Dermochelys coriacea) are all less abundant and listed as endangered. Florida breeding populations of the green sea turtle (Chelonia mydas) are listed as endangered, but green turtles in other US waters are considered threatened. The National Marine Fisheries Service (NMFS) has determined, based on the best available information, that because of their life cycle and behavioral patterns only themore » loggerhead, the green, and the Kemp`s ridley are put at risk by hopper dredging activities (Studt 1987).« less

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice

NASA Astrophysics Data System (ADS)

Evans, Eleanor; Sawiak, Stephen J.; Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T.

2014-01-01

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18F-FDG respectively to ascertain the technique‧s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice.

PubMed

Evans, Eleanor; Sawiak, Stephen J; Ward, Alexander O; Buonincontri, Guido; Hawkes, Robert C; Carpenter, T Adrian

2014-01-11

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18 F-FDG respectively to ascertain the technique's validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

76 FR 23571 - Marine Mammals and Endangered Species; File Nos. 15415 and 14622

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-27

... border. Dr. Kraus is authorized to conduct control and experimental visual trials to determine if right... during non-linear transect surveys and hand capture loggerhead, Kemp's ridley, and hawksbill sea turtles...

Use of thermal analysis techniques (TG-DSC) for the characterization of diverse organic municipal waste streams to predict biological stability prior to land application.

PubMed

Fernández, José M; Plaza, César; Polo, Alfredo; Plante, Alain F

2012-01-01

The use of organic municipal wastes as soil amendments is an increasing practice that can divert significant amounts of waste from landfill, and provides a potential source of nutrients and organic matter to ameliorate degraded soils. Due to the high heterogeneity of organic municipal waste streams, it is difficult to rapidly and cost-effectively establish their suitability as soil amendments using a single method. Thermal analysis has been proposed as an evolving technique to assess the stability and composition of the organic matter present in these wastes. In this study, three different organic municipal waste streams (i.e., a municipal waste compost (MC), a composted sewage sludge (CS) and a thermally dried sewage sludge (TS)) were characterized using conventional and thermal methods. The conventional methods used to test organic matter stability included laboratory incubation with measurement of respired C, and spectroscopic methods to characterize chemical composition. Carbon mineralization was measured during a 90-day incubation, and samples before and after incubation were analyzed by chemical (elemental analysis) and spectroscopic (infrared and nuclear magnetic resonance) methods. Results were compared with those obtained by thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. Total amounts of CO(2) respired indicated that the organic matter in the TS was the least stable, while that in the CS was the most stable. This was confirmed by changes detected with the spectroscopic methods in the composition of the organic wastes due to C mineralization. Differences were especially pronounced for TS, which showed a remarkable loss of aliphatic and proteinaceous compounds during the incubation process. TG, and especially DSC analysis, clearly reflected these differences between the three organic wastes before and after the incubation. Furthermore, the calculated energy density, which represents the energy available per unit of organic

The rise and fall of an ancient Adélie penguin `supercolony' at Cape Adare, Antarctica

NASA Astrophysics Data System (ADS)

Emslie, Steven D.; McKenzie, Ashley; Patterson, William P.

2018-04-01

We report new discoveries and radiocarbon dates on active and abandoned Adélie penguin (Pygoscelis adeliae) colonies at Cape Adare, Antarctica. This colony, first established at approximately 2000 BP (calendar years before present, i.e. 1950), is currently the largest for this species with approximately 338 000 breeding pairs, most located on low-lying Ridley Beach. We hypothesize that this colony first formed after fast ice began blocking open-water access by breeding penguins to the Scott Coast in the southern Ross Sea during a cooling period also at approximately 2000 BP. Our results suggest that the new colony at Cape Adare continued to grow, expanding to a large upper terrace above Ridley Beach, until it exceeded approximately 500 000 breeding pairs (a `supercolony') by approximately 1200 BP. The high marine productivity associated with the Ross Sea polynya and continental shelf break supported this growth, but the colony collapsed to its present size for unknown reasons after approximately 1200 BP. Ridley Beach will probably be abandoned in the near future due to rising sea level in this region. We predict that penguins will retreat to higher elevations at Cape Adare and that the Scott Coast will be reoccupied by breeding penguins as fast ice continues to dissipate earlier each summer, restoring open-water access to beaches there.

The rise and fall of an ancient Adélie penguin 'supercolony' at Cape Adare, Antarctica.

PubMed

Emslie, Steven D; McKenzie, Ashley; Patterson, William P

2018-04-01

We report new discoveries and radiocarbon dates on active and abandoned Adélie penguin ( Pygoscelis adeliae ) colonies at Cape Adare, Antarctica. This colony, first established at approximately 2000 BP (calendar years before present, i.e. 1950), is currently the largest for this species with approximately 338 000 breeding pairs, most located on low-lying Ridley Beach. We hypothesize that this colony first formed after fast ice began blocking open-water access by breeding penguins to the Scott Coast in the southern Ross Sea during a cooling period also at approximately 2000 BP. Our results suggest that the new colony at Cape Adare continued to grow, expanding to a large upper terrace above Ridley Beach, until it exceeded approximately 500 000 breeding pairs (a 'supercolony') by approximately 1200 BP. The high marine productivity associated with the Ross Sea polynya and continental shelf break supported this growth, but the colony collapsed to its present size for unknown reasons after approximately 1200 BP. Ridley Beach will probably be abandoned in the near future due to rising sea level in this region. We predict that penguins will retreat to higher elevations at Cape Adare and that the Scott Coast will be reoccupied by breeding penguins as fast ice continues to dissipate earlier each summer, restoring open-water access to beaches there.

The rise and fall of an ancient Adélie penguin ‘supercolony’ at Cape Adare, Antarctica

PubMed Central

McKenzie, Ashley; Patterson, William P.

2018-01-01

We report new discoveries and radiocarbon dates on active and abandoned Adélie penguin (Pygoscelis adeliae) colonies at Cape Adare, Antarctica. This colony, first established at approximately 2000 BP (calendar years before present, i.e. 1950), is currently the largest for this species with approximately 338 000 breeding pairs, most located on low-lying Ridley Beach. We hypothesize that this colony first formed after fast ice began blocking open-water access by breeding penguins to the Scott Coast in the southern Ross Sea during a cooling period also at approximately 2000 BP. Our results suggest that the new colony at Cape Adare continued to grow, expanding to a large upper terrace above Ridley Beach, until it exceeded approximately 500 000 breeding pairs (a ‘supercolony’) by approximately 1200 BP. The high marine productivity associated with the Ross Sea polynya and continental shelf break supported this growth, but the colony collapsed to its present size for unknown reasons after approximately 1200 BP. Ridley Beach will probably be abandoned in the near future due to rising sea level in this region. We predict that penguins will retreat to higher elevations at Cape Adare and that the Scott Coast will be reoccupied by breeding penguins as fast ice continues to dissipate earlier each summer, restoring open-water access to beaches there. PMID:29765656

Characterisation of 1,3-diammonium propylselenate monohydrate by XRD, FT-IR, FT-Raman, DSC and DFT studies

NASA Astrophysics Data System (ADS)

Thirunarayanan, S.; Arjunan, V.; Marchewka, M. K.; Mohan, S.; Atalay, Yusuf

2016-03-01

The crystals of 1,3-diammonium propylselenate monohydrate (DAPS) were prepared and characterised X-ray diffraction (XRD), FT-IR, FT-Raman spectroscopy, and DFT/B3LYP methods. It comprises protonated propyl ammonium moieties (diammonium propyl cations), selenate anions and water molecule which are held together by a number of hydrogen bonds and form infinite chains. The XRD data confirm the transfer of two protons from selenic acid to 1,3-diaminopropane molecule. The DAPS complex is stabilised by the presence of O-H···O and N-H···O hydrogen bonds and the electrostatic interactions as well. The N···O and O···O bond distances are 2.82-2.91 and 2.77 Å, respectively. The FT-IR and FT-Raman spectra of 1,3-diammonium propyl selenate monohydrate are recorded and the complete vibrational assignments have been discussed. The geometry is optimised by B3LYP method using 6-311G, 6-311+G and 6-311+G* basis sets and the energy, structural parameters, vibrational frequencies, IR and Raman intensities are determined. Differential scanning colorimetry (DSC) data were also presented to analyse the possibility of the phase transition. Complete natural bonding orbital (NBO) analysis is carried out to analyse the intramolecular electronic interactions and their stabilisation energies. The electrostatic potential of the complex lies in the range +1.902e × 10-2 to -1.902e × 10-2. The limits of total electron density of the complex is +8.43e × 10-2 to -8.43e × 10-2.

75 FR 19656 - Receipt of Applications for Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-15

... (NEWFS), Framingham, MA; PRT-06998A The applicant requests a permit to export leaf cuttings from Jesup's..., Danbury, CT; PRT- 234773 The applicant requests a permit to import blood samples from Olive Ridley sea...

Deepwater Horizon oil spill impacts on sea turtles could span the Atlantic

PubMed Central

Putman, Nathan F.; Abreu-Grobois, F. Alberto; Iturbe-Darkistade, Iñaky; Putman, Emily M.; Richards, Paul M.; Verley, Philippe

2015-01-01

We investigated the extent that the 2010 Deepwater Horizon oil spill potentially affected oceanic-stage sea turtles from populations across the Atlantic. Within an ocean-circulation model, particles were backtracked from the Gulf of Mexico spill site to determine the probability of young turtles arriving in this area from major nesting beaches. The abundance of turtles in the vicinity of the oil spill was derived by forward-tracking particles from focal beaches and integrating population size, oceanic-stage duration and stage-specific survival rates. Simulations indicated that 321 401 (66 199–397 864) green (Chelonia mydas), loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) turtles were likely within the spill site. These predictions compared favourably with estimates from in-water observations recently made available to the public (though our initial predictions for Kemp's ridley were substantially lower than in-water estimates, better agreement was obtained with modifications to mimic behaviour of young Kemp's ridley turtles in the northern Gulf). Simulations predicted 75.2% (71.9–76.3%) of turtles came from Mexico, 14.8% (11–18%) from Costa Rica, 5.9% (4.8–7.9%) from countries in northern South America, 3.4% (2.4–3.5%) from the United States and 1.6% (0.6–2.0%) from West African countries. Thus, the spill's impacts may extend far beyond the current focus on the northern Gulf of Mexico. PMID:26701754

Deepwater Horizon oil spill impacts on sea turtles could span the Atlantic.

PubMed

Putman, Nathan F; Abreu-Grobois, F Alberto; Iturbe-Darkistade, Iñaky; Putman, Emily M; Richards, Paul M; Verley, Philippe

2015-12-01

We investigated the extent that the 2010 Deepwater Horizon oil spill potentially affected oceanic-stage sea turtles from populations across the Atlantic. Within an ocean-circulation model, particles were backtracked from the Gulf of Mexico spill site to determine the probability of young turtles arriving in this area from major nesting beaches. The abundance of turtles in the vicinity of the oil spill was derived by forward-tracking particles from focal beaches and integrating population size, oceanic-stage duration and stage-specific survival rates. Simulations indicated that 321 401 (66 199-397 864) green (Chelonia mydas), loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) turtles were likely within the spill site. These predictions compared favourably with estimates from in-water observations recently made available to the public (though our initial predictions for Kemp's ridley were substantially lower than in-water estimates, better agreement was obtained with modifications to mimic behaviour of young Kemp's ridley turtles in the northern Gulf). Simulations predicted 75.2% (71.9-76.3%) of turtles came from Mexico, 14.8% (11-18%) from Costa Rica, 5.9% (4.8-7.9%) from countries in northern South America, 3.4% (2.4-3.5%) from the United States and 1.6% (0.6-2.0%) from West African countries. Thus, the spill's impacts may extend far beyond the current focus on the northern Gulf of Mexico. © 2015 The Authors.

Three closely related herpesviruses are associated with fibropapillomatosis in marine turtles

USGS Publications Warehouse

Quackenbush, S.L.; Work, Thierry M.; Balazs, George H.; Casey, Rufina N.; Rovnak, J.; Chaves, A.; duToit, L.; Baines, J.D.; Parrish, C.R.; Bowser, Paul R.; Casey, James W.

1998-01-01

Green turtle fibropapillomatosis is a neoplastic disease of increasingly significant threat to the survivability of this species. Degenerate PCR primers that target highly conserved regions of genes encoding herpesvirus DNA polymerases were used to amplify a DNA sequence from fibropapillomas and fibromas from Hawaiian and Florida green turtles. All of the tumors tested (n= 23) were found to harbor viral DNA, whereas no viral DNA was detected in skin biopsies from tumor-negative turtles. The tissue distribution of the green turtle herpesvirus appears to be generally limited to tumors where viral DNA was found to accumulate at approximately two to five copies per cell and is occasionally detected, only by PCR, in some tissues normally associated with tumor development. In addition, herpesviral DNA was detected in fibropapillomas from two loggerhead and four olive ridley turtles. Nucleotide sequencing of a 483-bp fragment of the turtle herpesvirus DNA polymerase gene determined that the Florida green turtle and loggerhead turtle sequences are identical and differ from the Hawaiian green turtle sequence by five nucleotide changes, which results in two amino acid substitutions. The olive ridley sequence differs from the Florida and Hawaiian green turtle sequences by 15 and 16 nucleotide changes, respectively, resulting in four amino acid substitutions, three of which are unique to the olive ridley sequence. Our data suggest that these closely related turtle herpesviruses are intimately involved in the genesis of fibropapillomatosis.

Marine turtle mitogenome phylogenetics and evolution.

PubMed

Duchene, Sebastián; Frey, Amy; Alfaro-Núñez, Alonzo; Dutton, Peter H; Thomas P Gilbert, M; Morin, Phillip A

2012-10-01

The sea turtles are a group of cretaceous origin containing seven recognized living species: leatherback, hawksbill, Kemp's ridley, olive ridley, loggerhead, green, and flatback. The leatherback is the single member of the Dermochelidae family, whereas all other sea turtles belong in Cheloniidae. Analyses of partial mitochondrial sequences and some nuclear markers have revealed phylogenetic inconsistencies within Cheloniidae, especially regarding the placement of the flatback. Population genetic studies based on D-Loop sequences have shown considerable structuring in species with broad geographic distributions, shedding light on complex migration patterns and possible geographic or climatic events as driving forces of sea-turtle distribution. We have sequenced complete mitogenomes for all sea-turtle species, including samples from their geographic range extremes, and performed phylogenetic analyses to assess sea-turtle evolution with a large molecular dataset. We found variation in the length of the ATP8 gene and a highly variable site in ND4 near a proton translocation channel in the resulting protein. Complete mitogenomes show strong support and resolution for phylogenetic relationships among all sea turtles, and reveal phylogeographic patterns within globally-distributed species. Although there was clear concordance between phylogenies and geographic origin of samples in most taxa, we found evidence of more recent dispersal events in the loggerhead and olive ridley turtles, suggesting more recent migrations (<1 Myr) in these species. Overall, our results demonstrate the complexity of sea-turtle diversity, and indicate the need for further research in phylogeography and molecular evolution. Published by Elsevier Inc.

77 FR 61573 - Endangered and Threatened Species; Initiation of 5-Year Review for Kemp's Ridley, Olive Ridley...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-10

... FURTHER INFORMATION CONTACT: Larissa Plants, Office of Protected Resources, 301-427-8471. SUPPLEMENTARY...: (1) Species biology including, but not limited to, population trends, distribution, abundance...

75 FR 47825 - Emergency Exemption; Issuance of Emergency Permit to Rehabilitate Sea Turtles Affected by the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-09

... tag live sea turtles; transport live and dead sea turtles to rehabilitation facilities, satellite transmitter attachment sites, and necropsy sites and necropsy dead sea turtles and collect samples; examine gut contents from dead sea turtles; attach satellite transmitters to nesting Kemp's ridley turtles...

Use of thermal analysis techniques (TG-DSC) for the characterization of diverse organic municipal waste streams to predict biological stability prior to land application

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

Fernandez, Jose M., E-mail: joseman@sas.upenn.edu; Plaza, Cesar; Polo, Alfredo

2012-01-15

Highlights: Black-Right-Pointing-Pointer Thermal analysis was used to assess stability and composition of organic matter in three diverse municipal waste streams. Black-Right-Pointing-Pointer Results were compared with C mineralization during 90-day incubation, FTIR and {sup 13}C NMR. Black-Right-Pointing-Pointer Thermal analysis reflected the differences between the organic wastes before and after the incubation. Black-Right-Pointing-Pointer The calculated energy density showed a strong correlation with cumulative respiration. Black-Right-Pointing-Pointer Conventional and thermal methods provide complimentary means of characterizing organic wastes. - Abstract: The use of organic municipal wastes as soil amendments is an increasing practice that can divert significant amounts of waste from landfill, and providesmore » a potential source of nutrients and organic matter to ameliorate degraded soils. Due to the high heterogeneity of organic municipal waste streams, it is difficult to rapidly and cost-effectively establish their suitability as soil amendments using a single method. Thermal analysis has been proposed as an evolving technique to assess the stability and composition of the organic matter present in these wastes. In this study, three different organic municipal waste streams (i.e., a municipal waste compost (MC), a composted sewage sludge (CS) and a thermally dried sewage sludge (TS)) were characterized using conventional and thermal methods. The conventional methods used to test organic matter stability included laboratory incubation with measurement of respired C, and spectroscopic methods to characterize chemical composition. Carbon mineralization was measured during a 90-day incubation, and samples before and after incubation were analyzed by chemical (elemental analysis) and spectroscopic (infrared and nuclear magnetic resonance) methods. Results were compared with those obtained by thermogravimetry (TG) and differential scanning calorimetry (DSC

77 FR 27719 - Marine Mammals; File Nos. 16109 and 15575

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-11

... (Megaptera novaeangliae), North Atlantic right whale (Eubalaena glacialis), sei whale (B. borealis), sperm..., sei whale, sperm whale, green sea turtle, hawksbill sea turtle, loggerhead sea turtle, Kemp's ridley... in the EA, NMFS determined that issuance of the permits would not significantly impact the quality of...

78 FR 22239 - Endangered Species; File No. 16556

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-15

... Fisheries Science Center (NEFSC; Responsible Party: Dr. William Karp), 166 Water St., Woods Hole, MA 02543... research. ADDRESSES: The permit and related documents are available for review upon written request or by... request for a scientific research permit to take loggerhead, leatherback, Kemp's ridley, and green sea...

78 FR 59657 - Endangered Species; File No. 17304

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-27

..., Ph.D., U.S. Geological Survey, 3205 College Ave., Davie, Florida, 33314 has been issued a permit to... kempii), and green (Chelonia mydas) sea turtles for purposes of scientific research. ADDRESSES: The... scientific research permit to take loggerhead, green, hawksbill, and Kemp's ridley sea turtles had been...

Junior Leader Innovation: William Sims & Continuous Aim Fire

DTIC Science & Technology

2012-06-06

construction ever perpetrated by the white race.” – LT William S. Sims Admiral Sir Percy Scott , Royal Navy...Admiral Mason, Chief, Bureau of Ordnance Ridley McLean “He continued to be a thorn in the fat flesh of the naval hierarchy during his entire

Investigation of plastic debris ingestion by four species of sea turtles collected as bycatch in pelagic Pacific longline fisheries

USGS Publications Warehouse

Clukey, Katherine E.; Lepczyk, Christopher A.; Balazs, George H.; Work, Thierry M.; Lynch, Jennifer M.

2017-01-01

Ingestion of marine debris is an established threat to sea turtles. The amount, type, color and location of ingested plastics in the gastrointestinal tracts of 55 sea turtles from Pacific longline fisheries from 2012 to 2016 were quantified, and compared across species, turtle length, body condition, sex, capture location, season and year. Six approaches for quantifying amounts of ingested plastic strongly correlated with one another and included: number of pieces, mass, volume and surface area of plastics, ratio of plastic mass to body mass, and percentage of the mass of gut contents consisting of plastic. All olive ridley (n = 37), 90% of green (n = 10), 80% of loggerhead (n = 5) and 0% of leatherback (n = 3) turtles had ingested plastic; green turtles ingested significantly more than olive ridleys. Most debris was in the large intestines. No adverse health impacts (intestinal lesions, blockage, or poor body condition) due directly to plastic ingestion were noted.

Investigation of plastic debris ingestion by four species of sea turtles collected as bycatch in pelagic Pacific longline fisheries.

PubMed

Clukey, Katharine E; Lepczyk, Christopher A; Balazs, George H; Work, Thierry M; Lynch, Jennifer M

2017-07-15

Ingestion of marine debris is an established threat to sea turtles. The amount, type, color and location of ingested plastics in the gastrointestinal tracts of 55 sea turtles from Pacific longline fisheries from 2012 to 2016 were quantified, and compared across species, turtle length, body condition, sex, capture location, season and year. Six approaches for quantifying amounts of ingested plastic strongly correlated with one another and included: number of pieces, mass, volume and surface area of plastics, ratio of plastic mass to body mass, and percentage of the mass of gut contents consisting of plastic. All olive ridley (n=37), 90% of green (n=10), 80% of loggerhead (n=5) and 0% of leatherback (n=3) turtles had ingested plastic; green turtles ingested significantly more than olive ridleys. Most debris was in the large intestines. No adverse health impacts (intestinal lesions, blockage, or poor body condition) due directly to plastic ingestion were noted. Copyright © 2017. Published by Elsevier Ltd.

RNA and DNA interactions with zwitterionic and charged lipid membranes - a DSC and QCM-D study.

PubMed

Michanek, Agnes; Kristen, Nora; Höök, Fredrik; Nylander, Tommy; Sparr, Emma

2010-04-01

The aim of the present study is to establish under which conditions tRNA associates with phospholipid bilayers, and to explore how this interaction influences the lipid bilayer. For this purpose we have studied the association of tRNA or DNA of different sizes and degrees of base pairing with a set of model membrane systems with varying charge densities, composed of zwitterionic phosphatidylcholines (PC) in mixtures with anionic phosphatidylserine (PS) or cationic dioctadecyl-dimethyl-ammoniumbromide (DODAB), and with fluid or solid acyl-chains (oleoyl, myristoyl and palmitoyl). To prove and quantify the attractive interaction between tRNA and model-lipid membrane we used quartz crystal microbalance with dissipation (QCM-D) monitoring to study the tRNA adsorption to deposit phospholipid bilayers from solutions containing monovalent (Na(+)) or divalent (Ca(2+)) cations. The influence of the adsorbed polynucleic acids on the lipid phase transitions and lipid segregation was studied by means of differential scanning calorimetry (DSC). The basic findings are: i) tRNA adsorbs to zwitterionic liquid-crystalline and gel-phase phospholipid bilayers. The interaction is weak and reversible, and cannot be explained only on the basis of electrostatic attraction. ii) The adsorbed amount of tRNA is higher for liquid-crystalline bilayers compared to gel-phase bilayers, while the presence of divalent cations show no significant effect on the tRNA adsorption. iii) The adsorption of tRNA can lead to segregation in the mixed 1,2-dimyristoyl-sn-glycerol-3-phosphatidylcholine (DMPC)-1,2-dimyristoyl-sn-glycero-3-phosphatidylserine (DMPS) and DMPC-DODAB bilayers, where tRNA is likely excluded from the anionic DMPS-rich domains in the first system, and associated with the cationic DODAB-rich domains in the second system. iv) The addition of shorter polynucleic acids influence the chain melting transition and induce segregation in a mixed DMPC-DMPS system, while larger polynucleic acids do

DSC and optical studies on BaO-Li{sub 2}O-B{sub 2}O{sub 3}-CuO glass system

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

Bhogi, Ashok, E-mail: ashokbhogi@gmail.com; Kumar, R. Vijaya; Ahmmad, Shaik Kareem

2016-05-06

Glasses with composition 15BaO-25Li{sub 2}O-(60-x)B{sub 2}O{sub 3} -xCuO (x= 0, 0.2, 0.4, 0.6, 0.8 and 1 mol%) were prepared by the conventional melt quenching technique. These glasses were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and density measurements. Optical absorption studies were carried out as a function of copper ion concentration. The optical absorption spectra of studied glasses containing copper oxide exhibit a single broad band around 761nm which has been assigned to the 2B{sub 1g}→2B{sub 2g} transition. From these studies, the variations in the values of glass transition temperature (T{sub g}) have been observed. The fundamental absorption edgemore » has been determined from the optical absorption spectra. The values of optical band gap and Urbach energy were determined with increase in concentration of CuO. The variations in density, glass transition temperature, optical band gap and Urbach energy with CuO content have been discussed in terms of changes in the glass structure. The analysis of these results indicated that copper ions mostly exist in Cu{sup 2+} state in these glasses when the concentration of CuO ≤ 0.8 mol% and above this concentration copper ions seem to subsist in Cu{sup 1+} state.« less

75 FR 33578 - Endangered Species; File Nos. 14508 and 14655

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-14

... (Lepidochelys kempii) sea turtles for purposes of scientific research. ADDRESSES: The permit and related... abundance, genetic origin and feeding ecology of sea turtles using Lake Worth Lagoon in Palm Beach County, Florida. Up to 50 green, 5 loggerhead, 2 hawksbill, and 1 Kemp's ridley sea turtles may be captured...

78 FR 51712 - Endangered Species; File No. 16733

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-21

... Fisheries Science Center (SEFSC; Responsible Party: Bonnie Ponwith), 75 Virginia Beach Dr., Miami, FL 33149... coriacea), and olive ridley (L. olivacea) sea turtles for purposes of scientific research. ADDRESSES: The... threatened species, and (3) is consistent with the purposes and policies set forth in section 2 of the ESA...

Crystallization kinetic of Sb-V2O5-TeO2 glasses investigated by DSC and their elastic moduli and Poisson's ratio

NASA Astrophysics Data System (ADS)

Souri, Dariush

2015-01-01

Ternary tellurate glasses of the form xSb-(60-x)V2O5-40TeO2 (0≤x≤15 in mol%) were prepared by using the usual melt quenching method. Differential scanning calorimetry (DSC) at different heating rates (φ) was used to thermal analyze and to gain more insight in to the thermal stability, glass forming tendency and so calorimetric behavior of the present glasses. The glass transition temperature (Tg), the temperature corresponding to the onset of crystallization (Tx) and also the crystallization temperature (TCr) were obtained at different heating rates, to estimate the key kinetic parameter of activation energy of crystallization (ΔE) by using different empirical formulas. Also some other thermal parameters such as thermal stability and glass forming tendency were determined. It was found that Tg, Tx and TCr increase with increase in Sb content and also with increase in heating rate. Moreover, Makishima-Makenzie's theory was employed to evaluate the Poisson's ratio and elastic moduli, indicating a strong relation between elastic properties and the structure of glass. From the mechanical and thermal data and also the values of oxygen molar volume ( V O *), it was founded that the glass systems can be divided in to "two compositional regions"; so, results indicate that glasses with 10≤x≤15 (especially for x=12) are more thermal stable and strong glasses, which make them as more useful and promising materials in technological advantages and device manufacturing.

Decline of the Sea Turtles: Causes and Prevention.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Life Sciences.

A report submitted by the Committee on Sea Turtle Conservation, addresses threats to the world's sea turtle populations to fulfill a mandate of the Endangered Species Act Amendments of 1988. It presents information on the populations, biology, ecology, and behavior of five endangered or threatened turtle species: the Kemp's ridley, loggerhead,…

A Positive Psychology That Matters

ERIC Educational Resources Information Center

Lopez, Shane L.; Magyar-Moe, Jeana L.

2006-01-01

The Major Contribution intended to situate positive psychology in counseling psychology's past and future and in the complex world we live and work in today. The four reactions (Frazier, Lee,& Steger; Gerstein; Linley; Mollen, Ethington,& Ridley) provide new insights into how counseling psychology has and will contribute to the study of human…

Learning from Experience: A Report from Mexico's Turtle Trip 2000.

ERIC Educational Resources Information Center

Jankowska, Marta Maja

2000-01-01

Fifteen high school students and adults from Idaho traveled to Mexico to assist the One World Workforce with monitoring the nests of olive ridley sea turtles. Only 1 percent of these endangered turtles mature to adulthood. The volunteers protected the eggs from poachers and helped the hatchlings get safely to the water. (TD)

A.C. impedance, XRD, DSC, SEM and charge/discharge studies on Al2O3, TiO2, SiO2 dispersoid LiPF6/PVC/PVdF-co-HFP composite polymer electrolytes by phase inversion

NASA Astrophysics Data System (ADS)

Vickraman, P.; Gopukumar, S.

2017-07-01

The PVC/PVdF-co-HFP composite polymer electrolyte membranes (CPEMs) by varying blend ratios 1:1, 1:2, and 2:1 with fixed content of Al2O3, TiO2 and SiO2 having soaked in 0.5 M LiPF6 in EC/DEC (1:1) v/v) have been prepared by phase inversion. CPEMs of higher ionic conductivity (not dependent on electrolyte uptake as observed in our study) ASA4 (3.61×10-4 Scm-1), TSA3 (1.53×10-4 Scm-1), and SSA3 (4.81×10-4 Scm-1) have been only chosen for XRD, DSC, SEM and electrochemical studies. In XRD, crystalline peaks (phases) of PVdF have been noted with/without change in intensity as well as FWHM which correspond to type of filler interaction with host matrix. In DSC, it is observed that shifts in baseline, melting endotherms, and area under the endotherms indicating the thermal hist ory of PVC (Tg = 82 ° C) and melting of VdF crystallites varied with nature of the filler dispersoid. In SEM, the coagulated fibrils of the polymer coiled with the sponge like structure has been mapped. The charge/discharge studies are carried out on these CPEMs at C/10 rate in the voltage range 2.8 V - 4.2 V, and it is noted that the TSA3 showed better cycling performance with good capacity retention i.e., 50 cycles with 66% capacity retention than ASA4 of 28 cycles with 65% and SSA3 of 5 cycles with 56%. In the present study Coulombic efficiency is concerned only for first cycle and it is noted that the TSA3 showed 71% than 66% and 62% respectively for SSA3 and ASA4.

Persistent organic pollutants in fat of three species of Pacific pelagic longline caught sea turtles: Accumulation in relation to ingested plastic marine debris

USGS Publications Warehouse

Clukey, Katharine; Lepczyk, Christopher A.; Balazs, George H.; Work, Thierry M.; Li, Qing X.; Bachman, Melanie J.; Lynch, Jennifer M.

2017-01-01

In addition to eating contaminated prey, sea turtles may be exposed to persistent organic pollutants (POPs) from ingesting plastic debris that has absorbed these chemicals. Given the limited knowledge about POPs in pelagic sea turtles and how plastic ingestion influences POP exposure, our objectives were to: 1) provide baseline contaminant levels of three species of pelagic Pacific sea turtles; and 2) assess trends of contaminant levels in relation to species, sex, length, body condition and capture location. In addition, we hypothesized that if ingesting plastic is a significant source of POP exposure, then the amount of ingested plastic may be correlated to POP concentrations accumulated in fat. To address our objectives we compared POP concentrations in fat samples to previously described amounts of ingested plastic from the same turtles. Fat samples from 25 Pacific pelagic sea turtles [2 loggerhead (Caretta caretta), 6 green (Chelonia mydas) and 17 olive ridley (Lepidochelys olivacea) turtles] were analyzed for 81 polychlorinated biphenyls (PCBs), 20 organochlorine pesticides, and 35 brominated flame-retardants. The olive ridley and loggerhead turtles had higher ΣDDTs (dichlorodiphenyltrichloroethane and metabolites) than ΣPCBs, at a ratio similar to biota measured in the South China Sea and southern California. Green turtles had a ratio close to 1:1. These pelagic turtles had lower POP levels than previously reported in nearshore turtles. POP concentrations were unrelated to the amounts of ingested plastic in olive ridleys, suggesting that their exposure to POPs is mainly through prey. In green turtles, concentrations of ΣPCBs were positively correlated with the number of plastic pieces ingested, but these findings were confounded by covariance with body condition index (BCI). Green turtles with a higher BCI had eaten more plastic and also had higher POPs. Taken together, our findings suggest that sea turtles accumulate most POPs through their prey rather

Forest biodiversity and woody biomass harvesting

Treesearch

Deahn M. Donner; T. Bently Wigley; Darren A. Miller

2017-01-01

With the expected increase in demand for woody biomass to help meet renewable energy needs, one principal sustainability question has been whether this material can be removed from forest stands while still conserving biological diversity and retaining ecosystem functioning (Hecht et al. 2009; Berch, Morris, and Malcolm 2011; Ridley et al. 2013). In general,...

Introduction to the Special Section on Genomics

ERIC Educational Resources Information Center

Grigorenko, Elena L.; Dozier, Mary

2013-01-01

The debate about the relevance of human genetics knowledge to everyday life has been marked by fluctuations of interest and enthusiasm. The negative impact of eugenics on the public consciousness suppressed dialogue between geneticists and the public for most of the second half of the 20th century (Ridley, 1999). For the most part, nongeneticists…

Fishery gear interactions from stranded bottlenose dolphins, Florida manatees and sea turtles in Florida, U.S.A.

PubMed

Adimey, Nicole M; Hudak, Christine A; Powell, Jessica R; Bassos-Hull, Kim; Foley, Allen; Farmer, Nicholas A; White, Linda; Minch, Karrie

2014-04-15

Documenting the extent of fishery gear interactions is critical to wildlife conservation efforts, especially for reducing entanglements and ingestion. This study summarizes fishery gear interactions involving common bottlenose dolphins (Tursiops truncatus truncatus), Florida manatees (Trichechus manatus latirostris) and sea turtles: loggerhead (Caretta caretta), green turtle (Chelonia mydas), leatherback (Dermochelys coriacea), hawksbill (Eretmochelys imbricata), Kemp's ridley (Lepidochelys kempii), and olive ridley (Lepidochelys olivacea) stranding in Florida waters during 1997-2009. Fishery gear interactions for all species combined were 75.3% hook and line, 18.2% trap pot gear, 4.8% fishing nets, and 1.7% in multiple gears. Total reported fishery gear cases increased over time for dolphins (p<0.05), manatees (p<0.01), loggerheads (p<0.05) and green sea turtles (p<0.05). The proportion of net interaction strandings relative to total strandings for loggerhead sea turtles increased (p<0.05). Additionally, life stage and sex patterns were examined, fishery gear interaction hotspots were identified and generalized linear regression modeling was conducted. Published by Elsevier Ltd.

Measurement of Peroxyacetyl Nitrate (PAN), Peroxypropionyl Nitrate (PPN) and Peroxymethacryloyl Nitrate (MPAN) during TRACE-P

NASA Technical Reports Server (NTRS)

Flocke, Frank; Weinheimer, Andrew J.

2003-01-01

In Fall 2000, the PANs gas chromatograph (GC) was improved and prepared for installation on the NASA P-3. A number of experiments were conducted in conjunction with the NCAR NO,, instrument (B. Ridley) to settle some of the fine details of the output of the calibration system for each instrument. In addition, the sampling frequency was improved.

Photo Surfing in Blade Runner

ERIC Educational Resources Information Center

Ohler, Jason

2005-01-01

This month's "Mining Movies" looks at Blade Runner, Ridley Scott's film set in the year 2019. It is a sad time for Earth, which is in the midst of environmental degradation so severe that other planets are being prepared for colonization. The main source of labor for this preparation work are "replicants," organic robots that look and behave like…

Differential Scanning Calorimetry Techniques: Applications in Biology and Nanoscience

PubMed Central

Gill, Pooria; Moghadam, Tahereh Tohidi; Ranjbar, Bijan

2010-01-01

This paper reviews the best-known differential scanning calorimetries (DSCs), such as conventional DSC, microelectromechanical systems-DSC, infrared-heated DSC, modulated-temperature DSC, gas flow-modulated DSC, parallel-nano DSC, pressure perturbation calorimetry, self-reference DSC, and high-performance DSC. Also, we describe here the most extensive applications of DSC in biology and nanoscience. PMID:21119929

Morphology of blends of linear and long-chain-branched polyethylenes in the solid state: A study by SANS, SAXS, and DSC

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

Wignall, G.D.; Londono, J.D.; Lin, J.S.

1995-04-24

Differential scanning calorimetry (DSC), small-angle neutron scattering (SANS), and X-ray scattering (SAXS) have been used to investigate the solid-state morphology of blends of linear (high density) and long-chain-branched (low-density) polyethylenes (HDPE/LDPE). The blends are homogeneous in the melt, as previously demonstrated by SANS using the contrast obtained by deuterating the linear polymer. However, due to the structural and melting point differences ({approximately} 20 C) between HDPE and LDPE, the components may phase segregate on slow cooling (0.75 C/min). For high concentrations ({phi} {ge} 0.5) of HDPE, relatively high rates of crystallization of the linear component lead to the formation ofmore » separate stacks of HDPE and LDPE lamellae, as indicated by two-peak SAXS curves. For predominantly branched blends, the difference in crystallization rate of the components becomes smaller and only one SAXS peak is observed, indicating that the two species are in the same lamellar stack. Moreover, the phases no longer consist of the pure component and the HDPE lamellae contain up to 15--20% LDPE (and vice versa). Rapid quenching into dry ice/2-propanol ({minus}78 C) produces only one SAXS peak (and hence one lamellar stack) over the whole concentration range. The blends show extensive cocrystallization, along with a tendency for the branched material to be preferentially located in the amorphous interlamellar regions. For high concentrations ({phi} > 0.5) of HDPE-D, the overall scattering length density (SLD) is high and the excess concentration of LDPE between the lamellae enhances the SLD contrast between the crystalline and amorphous phases. Thus, the interlamellar spacing (long period) is clearly visible in the SANS pattern. The blend morphology is a strong function of the quenching rate, and samples quenched less rapidly (e.g., into water at 23 C) are similar to slowly cooled blends.« less

Parenting the Gifted: The Ongoing Riddle of Which Nurture is Best for What Nature: Parents Promoting Gifted Potential

ERIC Educational Resources Information Center

Haensly, Patricia

2004-01-01

Matt Ridley, an Oxford-trained zoologist and science writer whose latest book is "Nature via Nurture: Genes, Experience, and What Makes Us Human" (2003a), wrote such an impressively clear and fascinating piece on "What Makes You Who You Are" that the author decided to use it to introduce the continuing pursuit of "What do I do to best promote…

Wide Area Recovery and Resiliency Program (WARRP) Knowledge Enhancement Working Group: Multi-Agency Coordination After Action Report

DTIC Science & Technology

2012-02-23

Kaski Charles Denver Office of Emergency Management Kellar Scott Arapahoe County/NCR Coordinator Krebs Kathleen Clear Creek County Krugman Jim USDA...Mower John Cubic Applications, Inc. Mueller Matt Denver Office of Emergency Management Ridley Teri WARRP Rubenstein Mike Jefferson County...Office of Emergency Management: Scott Field Denver Office of Emergency Management: Pat Williams Douglas County: Fran Santagata Douglas County: Steve

Environmental Impact Research Program. Life History and Environmental Requirements of Loggerhead Sea Turtles.

DTIC Science & Technology

1986-01-01

green turtles dig a deep body pit when nesting. LIFE HISTORY - 5. The greatest...were loggerheads, but greens and Kemp’s ridleys were also found . (Joyce 1982). Since the turtles were discovered during the winter, were covered...Preferences in the Loggerhead Sea Turtle , Caretta caretta," Copeia, Vol 1982, No. 4, pp 965-969. Hendrickson, J. R. 1958. " The Green Sea Turtle

Greg Wilson, D.Sc. | NREL

Science.gov Websites

Chemical Engineering from Washington University in St. Louis and a B.S. in Chemical Engineering from the Number 6,284,384. Gregory M. Wilson, et al., "Pressure Equalization System for Chemical Vapor

Conservation Hotspots for the Turtles on the High Seas of the Atlantic Ocean

PubMed Central

Huang, Hsiang-Wen

2015-01-01

Understanding the distribution of bycaught sea turtles could inform conservation strategies and priorities. This research analyses the distribution of turtles caught as longline fisheries bycatch on the high seas of the Atlantic Ocean. This research collected 18,142 bycatch observations and 47.1 million hooks from large-scale Taiwanese longline vessels in the Atlantic Ocean from June 2002 to December 2013. The coverage rates were ranged from 0.48% to 17.54% by year. Seven hundred and sixty-seven turtles were caught, and the major species were leatherback (59.8%), olive ridley (27.1%) and loggerhead turtles (8.7%). Most olive ridley (81.7%) and loggerhead (82.1%) turtles were hooked, while the leatherbacks were both hooked (44.0%) and entangled (31.8%). Depending on the species, 21.4% to 57.7% were dead when brought onboard. Most of the turtles were caught in tropical areas, especially in the Gulf of Guinea (15°N-10°S, 30°W-10°E), but loggerheads were caught in the south Atlantic Ocean (25°S-35°S, 40°W-10°E and 30°S-40°S, 55°W-45°W). The bycatch rate was the highest at 0.030 per 1000 hooks for leatherbacks in the tropical area. The bycatch rates of olive ridley ranged from 0 to 0.010 per thousand hooks. The loggerhead bycatch rates were higher in the northern and southern Atlantic Ocean and ranged from 0.0128 to 0.0239 per thousand hooks. Due to the characteristics of the Taiwanese deep-set longline fleet, bycatch rates were lower than those of coastal longline fisheries, but mortality rates were higher because of the long hours of operation. Gear and bait modification should be considered to reduce sea turtle bycatch and increase survival rates while reducing the use of shallow hooks would also be helpful. PMID:26267796

Reproductive synchrony in a recovering bottlenecked sea turtle population.

PubMed

Plot, Virginie; de Thoisy, Benoît; Blanc, Stéphane; Kelle, Laurent; Lavergne, Anne; Roger-Bérubet, Hélène; Tremblay, Yann; Fossette, Sabrina; Georges, Jean-Yves

2012-03-01

1. The assessment of species extinction risk has been well established for some time now. Assessing the potential for recovery in endangered species is however much more challenging, because complementary approaches are required to detect reliable signals of positive trends. 2. This study combines genetics, demography and behavioural data at three different time-scales to assess historical and recent population changes and evidence of reproductive synchrony in a small population of olive ridley sea turtle Lepidochelys olivacea. Lepidochelys is considered as the most extraordinary example of reproductive synchrony in reptiles, yet to date, it has only been reported in large populations. 3. Using Bayesian coalescent-based models on microsatellite nuclear DNA variability, we demonstrate that effective population size in olive ridleys nesting in French Guiana has dramatically declined by 99% over the last 20 centuries. This low current population size is further illustrated by the absence of genetic mitochondrial DNA diversity in the present nesting population. Yet, monitoring of nesting sites in French Guiana suggests a possible recovery of the population over the last decade. 4. Satellite telemetry shows that over the first 14 days of their 28-days inter-nesting interval, i.e. when eggs maturation is likely to occur, gravid females disperse over the continental shelf. They then gather together with a striking spatiotemporal consistency close to the nesting site, where they later emerge for their second nesting event. 5. Our results therefore suggest that reproductive synchrony also occurs in small populations. Olive ridleys may ensure this synchrony by adjusting the duration of the second half of their inter-nesting interval prior to landing, possibly through social mediation. 6. Such reproductive synchrony may be related to the maintenance of some species-specific strategy despite former collapse and may contribute to the present population recovery. The gregarious

Conservation hotspots for the turtles on the high seas of the Atlantic Ocean.

PubMed

Huang, Hsiang-Wen

2015-01-01

Understanding the distribution of bycaught sea turtles could inform conservation strategies and priorities. This research analyses the distribution of turtles caught as longline fisheries bycatch on the high seas of the Atlantic Ocean. This research collected 18,142 bycatch observations and 47.1 million hooks from large-scale Taiwanese longline vessels in the Atlantic Ocean from June 2002 to December 2013. The coverage rates were ranged from 0.48% to 17.54% by year. Seven hundred and sixty-seven turtles were caught, and the major species were leatherback (59.8%), olive ridley (27.1%) and loggerhead turtles (8.7%). Most olive ridley (81.7%) and loggerhead (82.1%) turtles were hooked, while the leatherbacks were both hooked (44.0%) and entangled (31.8%). Depending on the species, 21.4% to 57.7% were dead when brought onboard. Most of the turtles were caught in tropical areas, especially in the Gulf of Guinea (15°N-10°S, 30°W-10°E), but loggerheads were caught in the south Atlantic Ocean (25°S-35°S, 40°W-10°E and 30°S-40°S, 55°W-45°W). The bycatch rate was the highest at 0.030 per 1000 hooks for leatherbacks in the tropical area. The bycatch rates of olive ridley ranged from 0 to 0.010 per thousand hooks. The loggerhead bycatch rates were higher in the northern and southern Atlantic Ocean and ranged from 0.0128 to 0.0239 per thousand hooks. Due to the characteristics of the Taiwanese deep-set longline fleet, bycatch rates were lower than those of coastal longline fisheries, but mortality rates were higher because of the long hours of operation. Gear and bait modification should be considered to reduce sea turtle bycatch and increase survival rates while reducing the use of shallow hooks would also be helpful.

Sources of Vibrio mimicus Contamination of Turtle Eggs

PubMed Central

Acuña, María T.; Díaz, Gerardo; Bolaños, Hilda; Barquero, Candy; Sánchez, Olga; Sánchez, Luz M.; Mora, Grettel; Chaves, Anny; Campos, Elena

1999-01-01

Vibrio mimicus contamination of sand increased significantly during the arrival of the olive ridley sea turtles (Lepidochelys olivacea) at Ostional anidation beach, Costa Rica. Statistical analysis supports that eggs are contaminated with V. mimicus by contact with the sand nest. V. mimicus was isolated from eggs of all nests tested, and ctxA+ strains were found in 31% of the nests, all of which were near the estuary. PMID:9872804

Annual Systems Engineering Conference (12th). Volume 1

DTIC Science & Technology

2009-10-29

extended systems have sustainability challenges, e.g.: – Internet applications subject to: overload, environmental disturbance, virus downtime...Sites in MD, DC, VA MHPCC PMRF: Bldg 105 Sites in Hawaii Camp Pendleton: MCTSSA China Lake (2): AV-8B, F/A-18 IBAR Edwards: Ridley Corona : NSWC El...Air Platform Integration 3 Approved for Public Release; Distribution is unlimited. NSWC Carderock West Bethesda, MD NSWC Corona Norco, CA NSWC Crane

Conference Proceedings of the Meeting of the Structures and Materials Panel of AGARD (67th) on New Light Alloys, Held in Mierlo, Netherlands on 3-5 October 1988

DTIC Science & Technology

1989-08-01

solution heat treatment. Before anodizing, acid (e.g. suilfochromic) etching is preferable to caustic etching. As observed on 8090, the attack doe to the...differences in preferred crystallographic orientation. From the 1111) pole figures in Fig. 19 it is evident that the texture is much more pronounced in the... Ridley , N., "Cavitation and superplasticity", SUPERPLASTICITY, AGARD-LS-154, Aug. 1987, Paper No. 4. 11. Lane, P.L., Gray, J.A., and Smith, C.J.E

The Correlation between Current Marital Satisfaction and Premarital Counseling

DTIC Science & Technology

1985-05-04

Family , 3, 9 41-955. Ridley, C. A., Avery, A. W., Harrell, J. E., Leslie, L. A., & Dent, J. (1981). Conflict management : A premarital training program in...00 THE CORRELATION BETWEEN CURRENT MRITAL SATISFACTION AND PRE MARITAL COUNSELING California Family Study Center Burbank, CA Contract NOO228-8O-A-425...1 ! A Project submitted to the Faculty of California Family Study Center, in partial fulfillment of the requirements for the degree of Master of Arts

Analysis and Recommendation for a Fifteen Percent Cut in Space and Naval Warfare Command for Management Support Services

DTIC Science & Technology

2013-06-30

personalities. Additionally, we would like to thank Captain Scott Hoffman and LCDR Shane Derby for answering our questions and enlightening us on...Judith Downey of Scotia, NY, and has two sons named Ridley Penn (4) and newborn Jasper Drake. They currently reside in Monterey, CA. ^Åèìáëáíáçå...us to develop constraints for our model through a categorization process. In his 1992 Naval Postgraduate School thesis, Scott Donahue developed an

Clinical application of plasma thermograms. Utility, practical approaches and considerations

PubMed Central

Garbett, Nichola C.; Mekmaysy, Chongkham S.; DeLeeuw, Lynn; Chaires, Jonathan B.

2014-01-01

Differential scanning calorimetry (DSC) studies of blood plasma are part of an emerging area of the clinical application of DSC to biofluid analysis. DSC analysis of plasma from healthy individuals and patients with various diseases has revealed changes in the thermal profiles of the major plasma proteins associated with the clinical status of the patient. The sensitivity of DSC to the concentration of proteins, their interactions with other proteins or ligands, or their covalent modifications underlies the potential utility of DSC analysis. A growing body of literature has demonstrated the versatility and performance of clinical DSC analysis across a range of biofluids and in a number of disease settings. The principles, practice and challenges of DSC analysis of plasma are described in this article. PMID:25448297

Clinical application of plasma thermograms. Utility, practical approaches and considerations.

PubMed

Garbett, Nichola C; Mekmaysy, Chongkham S; DeLeeuw, Lynn; Chaires, Jonathan B

2015-04-01

Differential scanning calorimetry (DSC) studies of blood plasma are part of an emerging area of the clinical application of DSC to biofluid analysis. DSC analysis of plasma from healthy individuals and patients with various diseases has revealed changes in the thermal profiles of the major plasma proteins associated with the clinical status of the patient. The sensitivity of DSC to the concentration of proteins, their interactions with other proteins or ligands, or their covalent modification underlies the potential utility of DSC analysis. A growing body of literature has demonstrated the versatility and performance of clinical DSC analysis across a range of biofluids and in a number of disease settings. The principles, practice and challenges of DSC analysis of plasma are described in this article. Copyright © 2014 Elsevier Inc. All rights reserved.

47 CFR 80.409 - Station logs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... calling (DSC) equipment has been verified by actual communications or a test call; (ii) The portable... devices which do not have integral navigation receivers, including: VHF DSC, MF DSC, satellite EPIRB and HF DSC or INMARSAT SES. On a ship without integral or directly connected navigation receiver input to...

47 CFR 80.409 - Station logs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... calling (DSC) equipment has been verified by actual communications or a test call; (ii) The portable... devices which do not have integral navigation receivers, including: VHF DSC, MF DSC, satellite EPIRB and HF DSC or INMARSAT SES. On a ship without integral or directly connected navigation receiver input to...

Loss of Desmocollin 3 in Skin Tumor Development and Progression

PubMed Central

Chen, Jiangli; O’Shea, Charlene; Fitzpatrick, James E.; Koster, Maranke I.; Koch, Peter J.

2011-01-01

Desmocollin 3 (DSC3) is a desmosomal cadherin that is required for maintaining cell adhesion in the epidermis as demonstrated by the intra-epidermal blistering observed in Dsc3 null skin. Recently, it has been suggested that deregulated expression of DSC3 occurs in certain human tumor types. It is not clear whether DSC3 plays a role in the development or progression of cancers arising in stratified epithelia such as the epidermis. To address this issue, we generated a mouse model in which Dsc3 expression is ablated in K-Ras oncogene-induced skin tumors. Our results demonstrate that loss of Dsc3 leads to an increase in K-Ras induced skin tumors. We hypothesize that acantholysis-induced epidermal hyperplasia in the Dsc3 null epidermis facilitates Ras-induced tumor development. Further, we demonstrate that spontaneous loss of DSC3 expression is a common occurrence during human and mouse skin tumor progression. This loss occurs in tumor cells invading the dermis. Interestingly, other desmosomal proteins are still expressed in tumor cells that lack DSC3, suggesting a specific function of DSC3 loss in tumor progression. While loss of DSC3 on the skin surface leads to epidermal blistering, it does not appear to induce loss of cell-cell adhesion in tumor cells invading the dermis, most likely due to a protection of these cells within the dermis from mechanical stress. We thus hypothesize that DSC3 can contribute to the progression of tumors both by cell adhesion-dependent (skin surface) and likely by cell adhesion-independent (invading tumor cells) mechanisms. PMID:21681825

Are thermal barriers "higher" in deep sea turtle nests?

PubMed

Santidrián Tomillo, Pilar; Fonseca, Luis; Paladino, Frank V; Spotila, James R; Oro, Daniel

2017-01-01

Thermal tolerances are affected by the range of temperatures that species encounter in their habitat. Daniel Janzen hypothesized in his "Why mountain passes are higher in the tropics" that temperature gradients were effective barriers to animal movements where climatic uniformity was high. Sea turtles bury their eggs providing some thermal stability that varies with depth. We assessed the relationship between thermal uniformity and thermal tolerance in nests of three species of sea turtles. We considered that barriers were "high" when small thermal changes had comparatively large effects and "low" when the effects were small. Mean temperature was lower and fluctuated less in species that dig deeper nests. Thermal barriers were comparatively "higher" in leatherback turtle (Dermochelys coriacea) nests, which were the deepest, as embryo mortality increased at lower "high" temperatures than in olive ridley (Lepidochelys olivacea) and green turtle (Chelonia mydas) nests. Sea turtles have temperature-dependent sex determination (TSD) and embryo mortality increased as temperature approached the upper end of the transitional range of temperatures (TRT) that produces both sexes (temperature producing 100% female offspring) in leatherback and olive ridley turtles. As thermal barriers are "higher" in some species than in others, the effects of climate warming on embryo mortality is likely to vary among sea turtles. Population resilience to climate warming may also depend on the balance between temperatures that produce female offspring and those that reduce embryo survival.

Polychlorinated biphenyls and biotransformation enzymes in three species of sea turtles from the Baja California peninsula of Mexico.

PubMed

Richardson, K L; Lopez Castro, M; Gardner, S C; Schlenk, D

2010-01-01

Concentrations of polychlorinated biphenyls (PCBs) as well as the expression patterns of cytochrome P450 (CYP) enzymes and glutathione-S-transferase (GST) activities were measured in livers of loggerhead (Caretta caretta), green (Chelonia mydas), and olive ridley (Lepidocheyls olivacea) sea turtles from the Baja California peninsula of Mexico. The mean concentrations of total PCBs were 18.1, 10.5, and 15.2 ng/g wet weight (ww) respectively for the three species and PCB 153 was the dominant congener in all samples. Total PCB concentrations were dominated by penta- and hexa-chlorinated biphenyls. The mean estimated TEQs were 42.8, 22.9, and 10.4 pg/g (ww) for loggerhead, green, and olive ridley, respectively, and more than 70% was accounted for by non-ortho PCBs. Western blots revealed the presence of hepatic microsomal proteins that cross-reacted with anti-CYP2K1 and anti-CYP3A27 antibodies but not with anti-CYP1A antibody. There were no significant differences in GST activities between species. Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles. These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

Desmocollin 2 is a new immunohistochemical marker indicative of squamous differentiation in urothelial carcinoma.

PubMed

Hayashi, Tetsutaro; Sentani, Kazuhiro; Oue, Naohide; Anami, Katsuhiro; Sakamoto, Naoya; Ohara, Shinya; Teishima, Jun; Noguchi, Tsuyoshi; Nakayama, Hirofumi; Taniyama, Kiyomi; Matsubara, Akio; Yasui, Wataru

2011-10-01

Urothelial carcinoma (UC) with squamous differentiation tends to present at higher stages than pure UC. To distinguish UC with squamous differentiation from pure UC, a sensitive and specific marker is needed. Desmocollin 2 (DSC2) is a protein localized in desmosomal junctions of stratified epithelium, but little is known about its biological significance in bladder cancer. We examined the utility of DSC2 as a diagnostic marker. We analysed the immunohistochemical characteristics of DSC2, and studied the relationship of DSC2 expression with the expression of the known markers uroplakin III (UPIII), cytokeratin (CK)7, CK20, epidermal growth factor receptor (EGFR), and p53. DSC2 staining was detected in 24 of 25 (96%) cases of UC with squamous differentiation, but in none of 85 (0%) cases of pure UC. DSC2 staining was detected only in areas of squamous differentiation. DSC2 expression was mutually exclusive of UPIII expression, and was correlated with EGFR expression. Furthermore, DSC2 expression was correlated with higher stage (P = 0.0314) and poor prognosis (P = 0.0477). DSC2 staining offers high sensitivity (96%) and high specificity (100%) for the detection of squamous differentiation in UC. DSC2 is a useful immunohistochemical marker for separation of UC with squamous differentiation from pure UC. 2011 Blackwell Publishing Limited.

Utilizing Probability Distribution Functions and Ensembles to Forecast lonospheric and Thermosphere Space Weather

DTIC Science & Technology

2016-04-26

ELEMENT NUMBER 6. AUTHOR( S ) Ridley, Aaron J. 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND...ORGANIZATION REPORT NUMBER P/G # F030769 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) USAF, AFRL DUNS 143574726 AF OFFICE OF SCIENTIFIC...RESEARCH 875 NORTH RANDOLPH STREET, RM 31 12 ARLINGTON VA 22203 MALINDA E. ROGERS 703.696-1140 10. SPONSOR/MONITOR’S ACRONYM( S ) 11. SPONSOR/MONITOR’S

Direct Ca2+-dependent Heterophilic Interaction between Desmosomal Cadherins, Desmoglein and Desmocollin, Contributes to Cell–Cell Adhesion

PubMed Central

Chitaev, Nikolai A.; Troyanovsky, Sergey M.

1997-01-01

Human fibrosarcoma cells, HT-1080, feature extensive adherens junctions, lack mature desmosomes, and express a single known desmosomal protein, Desmoglein 2 (Dsg2). Transfection of these cells with bovine Desmocollin 1a (Dsc1a) caused dramatic changes in the subcellular distribution of endogenous Dsg2. Both cadherins clustered in the areas of the adherens junctions, whereas only a minor portion of Dsg2 was seen in these areas in the parental cells. Deletion mapping showed that intact extracellular cadherin-like repeats of Dsc1a (Arg1-Thr170) are required for the translocation of Dsg2. Deletion of the intracellular C-domain that mediates the interaction of Dsc1a with plakoglobin, or the CSI region that is involved in the binding to desmoplakin, had no effect. Coimmunoprecipitation experiments of cell lysates stably expressing Dsc1a with anti-Dsc or -Dsg antibodies demonstrate that the desmosomal cadherins, Dsg2 and Dsc1a, are involved in a direct Ca2+-dependent interaction. This conclusion was further supported by the results of solid phase binding experiments. These showed that the Dsc1a fragment containing cadherin-like repeats 1 and 2 binds directly to the extracellular portion of Dsg in a Ca2+-dependent manner. The contribution of the Dsg/ Dsc interaction to cell–cell adhesion was tested by coculturing HT-1080 cells expressing Dsc1a with HT-1080 cells lacking Dsc but expressing myc-tagged plakoglobin (MPg). In the latter cells, MPg and the endogenous Dsg form stable complexes. The observed specific coimmunoprecipitation of MPg by anti-Dsc antibodies in coculture indicates that an intercellular interaction between Dsc1 and Dsg is involved in cell–cell adhesion. PMID:9214392

Human decidual stromal cells secrete soluble pro-apoptotic factors during decidualization in a cAMP-dependent manner.

PubMed

Leno-Durán, E; Ruiz-Magaña, M J; Muñoz-Fernández, R; Requena, F; Olivares, E G; Ruiz-Ruiz, C

2014-10-10

Is there a relationship between decidualization and apoptosis of decidual stromal cells (DSC)? Decidualization triggers the secretion of soluble factors that induce apoptosis in DSC. The differentiation and apoptosis of DSC during decidualization of the receptive decidua are crucial processes for the controlled invasion of trophoblasts in normal pregnancy. Most DSC regress in a time-dependent manner, and their removal is important to provide space for the embryo to grow. However, the mechanism that controls DSC death is poorly understood. The apoptotic response of DSC was analyzed after exposure to different exogenous agents and during decidualization. The apoptotic potential of decidualized DSC supernatants and prolactin (PRL) was also evaluated. DSC lines were established from samples of decidua from first trimester pregnancies. Apoptosis was assayed by flow cytometry. PRL production, as a marker of decidualization, was determined by enzyme-linked immunosorbent assay. DSCs were resistant to a variety of apoptosis-inducing substances. Nevertheless, DSC underwent apoptosis during decidualization in culture, with cAMP being essential for both apoptosis and differentiation. In addition, culture supernatants from decidualized DSC induced apoptosis in undifferentiated DSC, although paradoxically these supernatants decreased the spontaneous apoptosis of decidual lymphocytes. Exogenously added PRL did not induce apoptosis in DSC and an antibody that neutralized the PRL receptor did not decrease the apoptosis induced by supernatants. Further studies are needed to examine the involvement of other soluble factors secreted by decidualized DSC in the induction of apoptosis. The present results indicate that apoptosis of DSC occurs in parallel to differentiation, in response to decidualization signals, with soluble factors secreted by decidualized DSC being responsible for triggering cell death. These studies are relevant in the understanding of how the regression of decidua

Comparative study of pulsed-continuous arterial spin labeling and dynamic susceptibility contrast imaging by histogram analysis in evaluation of glial tumors.

PubMed

Arisawa, Atsuko; Watanabe, Yoshiyuki; Tanaka, Hisashi; Takahashi, Hiroto; Matsuo, Chisato; Fujiwara, Takuya; Fujiwara, Masahiro; Fujimoto, Yasunori; Tomiyama, Noriyuki

2018-06-01

Arterial spin labeling (ASL) is a non-invasive perfusion technique that may be an alternative to dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) for assessment of brain tumors. To our knowledge, there have been no reports on histogram analysis of ASL. The purpose of this study was to determine whether ASL is comparable with DSC-MRI in terms of differentiating high-grade and low-grade gliomas by evaluating the histogram analysis of cerebral blood flow (CBF) in the entire tumor. Thirty-four patients with pathologically proven glioma underwent ASL and DSC-MRI. High-signal areas on contrast-enhanced T 1 -weighted images or high-intensity areas on fluid-attenuated inversion recovery images were designated as the volumes of interest (VOIs). ASL-CBF, DSC-CBF, and DSC-cerebral blood volume maps were constructed and co-registered to the VOI. Perfusion histogram analyses of the whole VOI and statistical analyses were performed to compare the ASL and DSC images. There was no significant difference in the mean values for any of the histogram metrics in both of the low-grade gliomas (n = 15) and the high-grade gliomas (n = 19). Strong correlations were seen in the 75th percentile, mean, median, and standard deviation values between the ASL and DSC images. The area under the curve values tended to be greater for the DSC images than for the ASL images. DSC-MRI is superior to ASL for distinguishing high-grade from low-grade glioma. ASL could be an alternative evaluation method when DSC-MRI cannot be used, e.g., in patients with renal failure, those in whom repeated examination is required, and in children.

Are thermal barriers "higher" in deep sea turtle nests?

PubMed Central

Santidrián Tomillo, Pilar; Fonseca, Luis; Paladino, Frank V.; Spotila, James R.; Oro, Daniel

2017-01-01

Thermal tolerances are affected by the range of temperatures that species encounter in their habitat. Daniel Janzen hypothesized in his “Why mountain passes are higher in the tropics” that temperature gradients were effective barriers to animal movements where climatic uniformity was high. Sea turtles bury their eggs providing some thermal stability that varies with depth. We assessed the relationship between thermal uniformity and thermal tolerance in nests of three species of sea turtles. We considered that barriers were “high” when small thermal changes had comparatively large effects and “low” when the effects were small. Mean temperature was lower and fluctuated less in species that dig deeper nests. Thermal barriers were comparatively “higher” in leatherback turtle (Dermochelys coriacea) nests, which were the deepest, as embryo mortality increased at lower “high” temperatures than in olive ridley (Lepidochelys olivacea) and green turtle (Chelonia mydas) nests. Sea turtles have temperature-dependent sex determination (TSD) and embryo mortality increased as temperature approached the upper end of the transitional range of temperatures (TRT) that produces both sexes (temperature producing 100% female offspring) in leatherback and olive ridley turtles. As thermal barriers are “higher” in some species than in others, the effects of climate warming on embryo mortality is likely to vary among sea turtles. Population resilience to climate warming may also depend on the balance between temperatures that produce female offspring and those that reduce embryo survival. PMID:28545092

Quantitative measurement of indomethacin crystallinity in indomethacin-silica gel binary system using differential scanning calorimetry and X-ray powder diffractometry.

PubMed

Pan, Xiaohong; Julian, Thomas; Augsburger, Larry

2006-02-10

Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) methods were developed for the quantitative analysis of the crystallinity of indomethacin (IMC) in IMC and silica gel (SG) binary system. The DSC calibration curve exhibited better linearity than that of XRPD. No phase transformation occurred in the IMC-SG mixtures during DSC measurement. The major sources of error in DSC measurements were inhomogeneous mixing and sampling. Analyzing the amount of IMC in the mixtures using high-performance liquid chromatography (HPLC) could reduce the sampling error. DSC demonstrated greater sensitivity and had less variation in measurement than XRPD in quantifying crystalline IMC in the IMC-SG binary system.

Transforming Benzophenoxazine Laser Dyes into Chromophores for Dye-Sensitized Solar Cells: A Molecular Engineering Approach

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

Schröder, Florian A. Y. N.; Cole, Jacqueline M.; Waddell, Paul G.

2015-02-03

The re-functionalization of a series of four well-known industrial laser dyes, based on benzophenoxazine, is explored with the prospect of molecularly engineering new chromophores for dye-sensitized solar cell (DSC) applications. Such engineering is important since a lack of suitable dyes is stifling the progress of DSC technology. The conceptual idea involves making laser dyes DSC-active by chemical modification, while maintaining their key property attributes that are attractive to DSC applications. This molecular engineering follows a step-wise approach. Firstly, molecular structures and optical absorption properties are determined for the parent laser dyes: Cresyl Violet (1); Oxazine 170 (2); Nile Blue Amore » (3), Oxazine 750 (4). These reveal structure-property relationships which define the prerequisites for computational molecular design of DSC dyes; the nature of their molecular architecture (D-π-A) and intramolecular charge transfer. Secondly, new DSC dyes are computationally designed by the in silico addition of a carboxylic acid anchor at various chemical substitution points in the parent laser dyes. A comparison of the resulting frontier molecular orbital energy levels with the conduction band edge of a TiO2 DSC photoanode and the redox potential of two electrolyte options I-/I3- and Co(II/III)tris(bipyridyl) suggests promise for these computationally designed dyes as co-sensitizers for DSC applications.« less

Media Coverage of FDA Drug Safety Communications about Zolpidem: A Quantitative and Qualitative Analysis.

PubMed

Woloshin, Steve; Schwartz, Lisa M; Dejene, Sara; Rausch, Paula; Dal Pan, Gerald J; Zhou, Esther H; Kesselheim, Aaron S

2017-05-01

FDA issues Drug Safety Communications (DSCs) to alert health care professionals and the public about emerging safety information affecting prescription and over-the-counter drugs. News media may amplify DSCs, but it is unclear how DSC messaging is transmitted through the media. We conducted a content analysis of the lay media coverage reaching the broadest audience to characterize the amount and content of media coverage of two zolpidem DSCs from 2013. After the first DSC, zolpidem news stories increased from 19 stories/week in the preceding 3 months to 153 following its release. Most (81%) appeared in the lay media, and 64% focused on the DSC content. After the second DSC, news stories increased from 24 stories/week in the preceding 3 months to 39 following. Among the 100 unique lay media news stories, at least half correctly reported three key DSC messages: next-day impairment and drowsiness as common safety hazards, lower doses for some but not all zolpidem products, and women's higher risk for impairment. Other DSC messages were reported in fewer than one-third of stories, such as the warning that impairment can happen even when people feel fully awake. The first-but not the second-zolpidem DSC generated high-profile news coverage. The finding that some messages were widely reported but others were not emphasizes the importance of ensuring translation of key DSC content.

47 CFR 80.225 - Requirements for selective calling equipment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... selective calling (DSC) equipment and selective calling equipment installed in ship and coast stations, and...-STD, “RTCM Recommended Minimum Standards for Digital Selective Calling (DSC) Equipment Providing... Class ‘D’ Digital Selective Calling (DSC)—Methods of testing and required test results,” March 2003. ITU...

Assessment of accuracy and efficiency of atlas-based autosegmentation for prostate radiotherapy in a variety of clinical conditions.

PubMed

Simmat, I; Georg, P; Georg, D; Birkfellner, W; Goldner, G; Stock, M

2012-09-01

The goal of the current study was to evaluate the commercially available atlas-based autosegmentation software for clinical use in prostate radiotherapy. The accuracy was benchmarked against interobserver variability. A total of 20 planning computed tomographs (CTs) and 10 cone-beam CTs (CBCTs) were selected for prostate, rectum, and bladder delineation. The images varied regarding to individual (age, body mass index) and setup parameters (contrast agent, rectal balloon, implanted markers). Automatically created contours with ABAS(®) and iPlan(®) were compared to an expert's delineation by calculating the Dice similarity coefficient (DSC) and conformity index. Demo-atlases of both systems showed different results for bladder (DSC(ABAS) 0.86 ± 0.17, DSC(iPlan) 0.51 ± 0.30) and prostate (DSC(ABAS) 0.71 ± 0.14, DSC(iPlan) 0.57 ± 0.19). Rectum delineation (DSC(ABAS) 0.78 ± 0.11, DSC(iPlan) 0.84 ± 0.08) demonstrated differences between the systems but better correlation of the automatically drawn volumes. ABAS(®) was closest to the interobserver benchmark. Autosegmentation with iPlan(®), ABAS(®) and manual segmentation took 0.5, 4 and 15-20 min, respectively. Automatic contouring on CBCT showed high dependence on image quality (DSC bladder 0.54, rectum 0.42, prostate 0.34). For clinical routine, efforts are still necessary to either redesign algorithms implemented in autosegmentation or to optimize image quality for CBCT to guarantee required accuracy and time savings for adaptive radiotherapy.

47 CFR 80.1087 - Ship radio equipment-Sea area A1.

Code of Federal Regulations, 2013 CFR

2013-10-01

... an INMARSAT ship earth station capable of two way communication. (b) The VHF radio installation... which the ship is normally navigated, operating either: (1) On VHF using DSC; or (2) Through the polar... voyages within coverage of MF coast stations equipped with DSC; or (4) On HF using DSC; or (5) Through the...

47 CFR 80.1087 - Ship radio equipment-Sea area A1.

Code of Federal Regulations, 2014 CFR

2014-10-01

... an INMARSAT ship earth station capable of two way communication. (b) The VHF radio installation... which the ship is normally navigated, operating either: (1) On VHF using DSC; or (2) Through the polar... voyages within coverage of MF coast stations equipped with DSC; or (4) On HF using DSC; or (5) Through the...

47 CFR 80.1087 - Ship radio equipment-Sea area A1.

Code of Federal Regulations, 2012 CFR

2012-10-01

... an INMARSAT ship earth station capable of two way communication. (b) The VHF radio installation... which the ship is normally navigated, operating either: (1) On VHF using DSC; or (2) Through the polar... voyages within coverage of MF coast stations equipped with DSC; or (4) On HF using DSC; or (5) Through the...

Center Variation and Outcomes Associated with Delayed Sternal Closure Following Stage 1 Palliation for Hypoplastic Left Heart Syndrome

PubMed Central

Johnson, Jason N.; Jaggers, James; Li, Shuang; O’Brien, Sean M.; Li, Jennifer S.; Jacobs, Jeffrey P.; Jacobs, Marshall L.; Welke, Karl F.; Peterson, Eric D.; Pasquali, Sara K.

2009-01-01

Objectives There is debate whether primary or delayed sternal closure (DSC) is the best strategy following Stage 1 palliation (S1P) for hypoplastic left heart syndrome (HLHS). We describe center variation in DSC following S1P and associated outcomes. Methods Society of Thoracic Surgeons Congenital Database participants performing S1P for HLHS from 2000–2007 were included. We examined center variation in DSC, and compared in-hospital mortality, prolonged length of stay (LOS >6wks), and postoperative infection in centers with low (≤25% of cases), middle (26%–74% of cases), and high (≥75% of cases) DSC utilization, adjusting for patient and center factors. Results There were 1283 patients (45 centers) included. Median age and weight at surgery were 6d (IQR4-9d) and 3.2 kg (IQR2.8–3.5kg); 59% were male. DSC was used in 74% (range 3–100% of cases/center). In centers with high (n=23) and middle (n=17) vs. low (n=5) DSC utilization, there was a greater proportion of patients with prolonged LOS and infection, and a trend toward increased in-hospital mortality in unadjusted analysis. In multivariable analysis, there was no difference in mortality. Centers with high and middle DSC utilization had prolonged LOS [OR (95%CI): 2.83(1.46–5.47) p=0.002 and 2.23(1.17–4.26) p=0.02] and more infection [2.34(1.20–4.57) p=0.01 and 2.37(1.36–4.16) p=0.003]. Conclusions Utilization of DSC following S1P varies widely. These observational data suggest more frequent use of DSC is associated with longer LOS and higher postoperative infection rates. Further evaluation of the risks and benefits of DSC in the management of these complex infants is necessary. PMID:20167337

Comparison of the transformation temperatures of heat-activated Nickel-Titanium orthodontic archwires by two different techniques.

PubMed

Obaisi, Noor Aminah; Galang-Boquiren, Maria Therese S; Evans, Carla A; Tsay, Tzong Guang Peter; Viana, Grace; Berzins, David; Megremis, Spiro

2016-07-01

The purpose of this study was to investigate the suitability of the Bend and Free Recovery (BFR) method as a standard test method to determine the transformation temperatures of heat-activated Ni-Ti orthodontic archwires. This was done by determining the transformation temperatures of two brands of heat-activated Ni-Ti orthodontic archwires using the both the BFR method and the standard method of Differential Scanning Calorimetry (DSC). The values obtained from the two methods were compared with each other and to the manufacturer-listed values. Forty heat-activated Ni-Ti archwires from both Rocky Mountain Orthodontics (RMO) and Opal Orthodontics (Opal) were tested using BFR and DSC. Round (0.016 inches) and rectangular (0.019×0.025 inches) archwires from each manufacturer were tested. The austenite start temperatures (As) and austenite finish temperatures (Af) were recorded. For four of the eight test groups, the BFR method resulted in lower standard deviations than the DSC method, and, overall, the average standard deviation for BFR testing was slightly lower than for DSC testing. Statistically significant differences were seen between the transformation temperatures obtained from the BFR and DSC test methods. However, the Af temperatures obtained from the two methods were remarkably similar with the mean differences ranging from 0.0 to 2.1°C: Af Opal round (BFR 26.7°C, DSC 27.6°C) and rectangular (BFR 27.6°C, DSC 28.6°C); Af RMO round (BFR 25.5°C, DSC 25.5°C) and rectangular (BFR 28.0°C, DSC 25.9°C). Significant differences were observed between the manufacturer-listed transformation temperatures and those obtained with BFR and DSC testing for both manufacturers. The results of this study suggest that the Bend and Free Recovery method is suitable as a standard method to evaluate the transformation temperatures of heat-activated Ni-Ti orthodontic archwires. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Forecasting range expansion into ecological traps: climate-mediated shifts in sea turtle nesting beaches and human development.

PubMed

Pike, David A

2013-10-01

Some species are adapting to changing environments by expanding their geographic ranges. Understanding whether range shifts will be accompanied by increased exposure to other threats is crucial to predicting when and where new populations could successfully establish. If species overlap to a greater extent with human development under climate change, this could form ecological traps which are attractive to dispersing individuals, but the use of which substantially reduces fitness. Until recently, the core nesting range for the Critically Endangered Kemp's ridley sea turtle (Lepidochelys kempii) was ca. 1000 km of sparsely populated coastline in Tamaulipas, Mexico. Over the past twenty-five years, this species has expanded its range into populated areas of coastal Florida (>1500 km outside the historical range), where nesting now occurs annually. Suitable Kemp's ridley nesting habitat has persisted for at least 140 000 years in the western Gulf of Mexico, and climate change models predict further nesting range expansion into the eastern Gulf of Mexico and northern Atlantic Ocean. Range expansion is 6-12% more likely to occur along uninhabited stretches of coastline than are current nesting beaches, suggesting that novel nesting areas will not be associated with high levels of anthropogenic disturbance. Although the high breeding-site fidelity of some migratory species could limit adaptation to climate change, rapid population recovery following effective conservation measures may enhance opportunities for range expansion. Anticipating the interactive effects of past or contemporary conservation measures, climate change, and future human activities will help focus long-term conservation strategies. © 2013 John Wiley & Sons Ltd.

Applications of high pressure differential scanning calorimetry to aviation fuel thermal stability research

NASA Technical Reports Server (NTRS)

Neveu, M. C.; Stocker, D. P.

1985-01-01

High pressure differential scanning calorimetry (DSC) was studied as an alternate method for performing high temperature fuel thermal stability research. The DSC was used to measure the heat of reaction versus temperature of a fuel sample heated at a programmed rate in an oxygen pressurized cell. Pure hydrocarbons and model fuels were studied using typical DSC operating conditions of 600 psig of oxygen and a temperature range from ambient to 500 C. The DSC oxidation onset temperature was determined and was used to rate the fuels on thermal stability. Kinetic rate constants were determined for the global initial oxidation reaction. Fuel deposit formation is measured, and the high temperature volatility of some tetralin deposits is studied by thermogravimetric analysis. Gas chromatography and mass spectrometry are used to study the chemical composition of some DSC stressed fuels.

Dye-sensitized solar cells consisting of dye-bilayer structure stained with two dyes for harvesting light of wide range of wavelength

NASA Astrophysics Data System (ADS)

Inakazu, Fumi; Noma, Yusuke; Ogomi, Yuhei; Hayase, Shuzi

2008-09-01

Dye-sensitized solar cells (DSCs) containing dye-bilayer structure of black dye and NK3705 (3-carboxymethyl-5-[3-(4-sulfobutyl)-2(3H)-bezothiazolylidene]-2-thioxo-4-thiazolidinone, sodium salt) in one TiO2 layer (2-TiO-BD-NK) are reported. The 2-TiO-BD-NK structure was fabricated by staining one TiO2 layer with these two dyes, step by step, under a pressurized CO2 condition. The dye-bilayer structure was observed by using a confocal laser scanning microscope. The short circuit current (Jsc) and the incident photon to current efficiency of the cell (DSC-2-TiO-BD-NK) was almost the sum of those of DSC stained with black dye only (DSC-1-TiO-BD) and DSC stained with NK3705 only (DSC-1-TiO-NK).

Theoretical Aspects of Differential Scanning Calorimetry as a Tool for the Studies of Equilibrium Thermodynamics in Pharmaceutical Solid Phase Transitions.

PubMed

Faroongsarng, Damrongsak

2016-06-01

Although differential scanning calorimetry (DSC) is a non-equilibrium technique, it has been used to gain energetic information that involves phase equilibria. DSC has been widely used to characterize the equilibrium melting parameters of small organic pharmaceutical compounds. An understanding of how DSC measures an equilibrium event could make for a better interpretation of the results. The aim of this mini-review was to provide a theoretical insight into the DSC measurement to obtain the equilibrium thermodynamics of a phase transition especially the melting process. It was demonstrated that the heat quantity obtained from the DSC thermogram (ΔH) was related to the thermodynamic enthalpy of the phase transition (ΔH (P) ) via: ΔH = ΔH (P) /(1 + K (- 1)) where K was the equilibrium constant. In melting, the solid and liquefied phases presumably coexist resulting in a null Gibbs free energy that produces an infinitely larger K. Thus, ΔH could be interpreted as ΔH (P). Issues of DSC investigations on melting behavior of crystalline solids including polymorphism, degradation impurity due to heating in situ, and eutectic melting were discussed. In addition, DSC has been a tool for determination of the impurity based on an ideal solution of the melt that is one of the official methods used to establish the reference standard.

Correlation of the penetration enhancement with the influence of an alcohol/tocopheryl polyethylene glycol succinate (TPGS) cosolvent system on the molecular structure of the stratum corneum of nude mouse skin as examined by microscopic FTIR/DSC

NASA Astrophysics Data System (ADS)

Liou, Yi-Bo; Ho, Hsiu-O.; Chen, Shin-Yi; Sheu, Ming-Thau

2009-10-01

Tocopheryl polyethylene glycol succinate (TPGS) is a water-soluble derivative of natural source of vitamin E, which possesses a dual nature of lipophilicity and hydrophilicity, similar to a surface-active agent. The penetration enhancement of estradiol by an ethanol and TPGS cosolvent system (EtOH/TPGS) has been confirmed. In this study, the correlation of the penetration enhancement with the influence of the EtOH/TPGS cosolvent system on biophysical changes of the stratum corneum (SC) as examined by Fourier transformation infrared spectrometry differential scanning calorimetry (FTIR/DSC) was investigated. Thermotropic changes in the asymmetrical and symmetrical C-H stretching of hydrocarbon chains of lipids, and amide I and II bands that characterize the protein structure of the SC treated with different concentrations of the EtOH/TPGS cosolvent were examined in this investigation. Results demonstrated that a strong correlation of the influence on biophysical changes of the SC treated with the EtOH/TPGS cosolvent system with the penetration enhancement of estradiol by the corresponding cosolvent system was not evident. It was concluded that the incorporation of TPGS in the cosolvent system seemed only to have insignificantly modified the structural features of the SC. It was not obvious that the penetrant had encountered these modifications resulting in an improvement in the penetration of estradiol by TPGS.

Potential for differentiation of pseudoprogression from true tumor progression with dynamic susceptibility-weighted contrast-enhanced magnetic resonance imaging using ferumoxytol versus gadoteridol: A pilot study

PubMed Central

Gahramanov, Seymur; Raslan, Ahmed; Muldoon, Leslie L.; Hamilton, Bronwyn E.; Rooney, William D.; Varallyay, Csanad G.; Njus, Jeffrey M.; Haluska, Marianne; Neuwelt, Edward A.

2010-01-01

Purpose We evaluated dynamic susceptibility-weighted contrast-enhanced magnetic resonance imaging (DSC-MRI) using gadoteridol in comparison to the iron oxide nanoparticle blood pool agent, ferumoxytol in patients with glioblastoma multiforme (GBM) who received standard radiochemotherapy (RCT). Methods and Materials Fourteen patients with GBM received standard RCT and underwent 19 MRI sessions that included DSC-MRI acquisitions with gadoteridol on day 1 and ferumoxytol on day 2. Relative cerebral blood volume (rCBV) values were calculated from DSC data obtained from each contrast agent. T1-weighted acquisition post-gadoteridol administration was used to identify enhancing regions. Results In 7 MRI sessions of clinically presumptive active tumor, gadoteridol-DSC showed low rCBV in 3 and high rCBV in 4, while ferumoxytol-DSC showed high rCBV in all 7 sessions (p=0.002). After RCT, 7 MRI sessions showed increased gadoteridol contrast enhancement on T1-weighted scans coupled with low rCBV without significant differences between contrast agents (p=0.9). Based on post-gadoteridol T1-weighted scans, DSC-MRI, and clinical presentation four patterns of response to RCT were observed: 1) regression, 2) pseudoprogression, 3) true progression, and 4) mixed response. Conclusion We conclude that DSC-MRI with a blood-pool agent such as ferumoxytol may provide a better monitor of tumor rCBV than DSC-MRI with gadoteridol. Lesions demonstrating increased enhancement on T1-weighted MRI coupled with low ferumoxytol rCBV, are likely exhibiting pseudoprogression, while high rCBV with ferumoxytol is a better marker than gadoteridol for determining active tumor. These interesting pilot observations suggest that ferumoxytol may differentiate tumor progression from pseudoprogression, and warrant further investigation. PMID:20395065

Homoacetogenesis in Deep-Sea Chloroflexi, as Inferred by Single-Cell Genomics, Provides a Link to Reductive Dehalogenation in Terrestrial Dehalococcoidetes

PubMed Central

Sewell, Holly L.; Kaster, Anne-Kristin

2017-01-01

ABSTRACT The deep marine subsurface is one of the largest unexplored biospheres on Earth and is widely inhabited by members of the phylum Chloroflexi. In this report, we investigated genomes of single cells obtained from deep-sea sediments of the Peruvian Margin, which are enriched in such Chloroflexi. 16S rRNA gene sequence analysis placed two of these single-cell-derived genomes (DscP3 and Dsc4) in a clade of subphylum I Chloroflexi which were previously recovered from deep-sea sediment in the Okinawa Trough and a third (DscP2-2) as a member of the previously reported DscP2 population from Peruvian Margin site 1230. The presence of genes encoding enzymes of a complete Wood-Ljungdahl pathway, glycolysis/gluconeogenesis, a Rhodobacter nitrogen fixation (Rnf) complex, glyosyltransferases, and formate dehydrogenases in the single-cell genomes of DscP3 and Dsc4 and the presence of an NADH-dependent reduced ferredoxin:NADP oxidoreductase (Nfn) and Rnf in the genome of DscP2-2 imply a homoacetogenic lifestyle of these abundant marine Chloroflexi. We also report here the first complete pathway for anaerobic benzoate oxidation to acetyl coenzyme A (CoA) in the phylum Chloroflexi (DscP3 and Dsc4), including a class I benzoyl-CoA reductase. Of remarkable evolutionary significance, we discovered a gene encoding a formate dehydrogenase (FdnI) with reciprocal closest identity to the formate dehydrogenase-like protein (complex iron-sulfur molybdoenzyme [CISM], DET0187) of terrestrial Dehalococcoides/Dehalogenimonas spp. This formate dehydrogenase-like protein has been shown to lack formate dehydrogenase activity in Dehalococcoides/Dehalogenimonas spp. and is instead hypothesized to couple HupL hydrogenase to a reductive dehalogenase in the catabolic reductive dehalogenation pathway. This finding of a close functional homologue provides an important missing link for understanding the origin and the metabolic core of terrestrial Dehalococcoides/Dehalogenimonas spp. and of

Voxel-based correlation between coregistered single-photon emission computed tomography and dynamic susceptibility contrast magnetic resonance imaging in subjects with suspected Alzheimer disease.

PubMed

Cavallin, L; Axelsson, R; Wahlund, L O; Oksengard, A R; Svensson, L; Juhlin, P; Wiberg, M Kristoffersen; Frank, A

2008-12-01

Current diagnosis of Alzheimer disease is made by clinical, neuropsychologic, and neuroimaging assessments. Neuroimaging techniques such as magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) could be valuable in the differential diagnosis of Alzheimer disease, as well as in assessing prognosis. To compare SPECT and MRI in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer disease (AD). 24 patients, eight with AD, 10 with MCI, and six controls, were investigated with SPECT using (99m)Tc-hexamethylpropyleneamine oxime (HMPAO, Ceretec; GE Healthcare Ltd., Little Chalsont UK) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a contrast-enhancing gadobutrol formula (Gadovist; Bayer Schering Pharma, Berlin, Germany). Voxel-based correlation between coregistered SPECT and DSC-MR images was calculated. Region-of-interest (ROI) analyses were then performed in 24 different brain areas using brain registration and analysis of SPECT studies (BRASS; Nuclear Diagnostics AB, Stockholm, Sweden) on both SPECT and DSC-MRI. Voxel-based correlation between coregistered SPECT and DSC-MR showed a high correlation, with a mean correlation coefficient of 0.94. ROI analyses of 24 regions showed significant differences between the control group and AD patients in 10 regions using SPECT and five regions in DSC-MR. SPECT remains superior to DSC-MRI in differentiating normal from pathological perfusion, and DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer disease.

Thermodynamics of micellization from heat-capacity measurements.

PubMed

Šarac, Bojan; Bešter-Rogač, Marija; Lah, Jurij

2014-06-23

Differential scanning calorimetry (DSC), the most important technique for studying the thermodynamics of structural transitions of biological macromolecules, is seldom used in quantitative thermodynamic studies of surfactant micellization/demicellization. The reason for this could be ascribed to an insufficient understanding of the temperature dependence of the heat capacity of surfactant solutions (DSC data) in terms of thermodynamics, which leads to problems with the design of experiments and interpretation of the output signals. We address these issues by careful design of DSC experiments performed with solutions of ionic and nonionic surfactants at various surfactant concentrations, and individual and global mass-action model analysis of the obtained DSC data. Our approach leads to reliable thermodynamic parameters of micellization for all types of surfactants, comparable with those obtained by using isothermal titration calorimetry (ITC). In summary, we demonstrate that DSC can be successfully used as an independent method to obtain temperature-dependent thermodynamic parameters for micellization. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Use of DSC and DMA Techniques to Help Investigate a Material Anomaly for PTFE Used in Processing a Piston Cup for the Urine Processor Assembly (UPA) on International Space Station (ISS)

NASA Technical Reports Server (NTRS)

Wingard, Doug

2010-01-01

Human urine and flush water are eventually converted into drinking water with the Urine Processor Assembly (UPA) aboard the International Space Station (ISS). This conversion is made possible through the Distillation Assembly (DA) of the UPA. One component of the DA is a molded circular piston cup made of virgin polytetrafluoroethylene (PTFE). The piston cup is assembled to a titanium component using eight fasteners and washers. Molded PTFE produced for spare piston cups in the first quarter of 2010 was different in appearance and texture, and softer than material molded for previous cups. For the suspect newer PTFE material, cup fasteners were tightened to only one-half the required torque value, yet the washers embedded almost halfway into the material. The molded PTFE used in the DA piston cup should be Type II, based on AMS 3667D and ASTM D4894 specifications. The properties of molded PTFE are considerably different between Type I and II materials. Engineers working with the DA thought that if Type I PTFE was molded by mistake instead of Type II material, that could have resulted in the anomalous material properties. Typically, the vendor molds flat sheet PTFE from the same material lot used to mold the piston cups, and tensile testing as part of quality control should verify that the PTFE is Type II material. However, for this discrepant lot of material, such tensile data was not available. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were two of the testing techniques used at the NASA/Marshall Space Flight Center (MSFC) to investigate the anomaly for the PTFE material. Other techniques used on PTFE specimens were: Shore D hardness testing, tensile testing on dog bone specimens and a qualitative estimation of porosity by optical and scanning electron microscopy.

Crystallization of Polymers Investigated by Temperature-Modulated DSC

PubMed Central

Righetti, Maria Cristina

2017-01-01

The aim of this review is to summarize studies conducted by temperature-modulated differential scanning calorimetry (TMDSC) on polymer crystallization. This technique can provide several advantages for the analysis of polymers with respect to conventional differential scanning calorimetry. Crystallizations conducted by TMDSC in different experimental conditions are analysed and discussed, in order to illustrate the type of information that can be deduced. Isothermal and non-isothermal crystallizations upon heating and cooling are examined separately, together with the relevant mathematical treatments that allow the evolution of the crystalline, mobile amorphous and rigid amorphous fractions to be determined. The phenomena of ‘reversing’ and ‘reversible‘ melting are explicated through the analysis of the thermal response of various semi-crystalline polymers to temperature modulation. PMID:28772807

DSC and Raman studies of silver borotellurite glasses

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

Kaur, Amandeep; Khanna, Atul, E-mail: atul.phy@gndu.ac.in; Gonzàlez, Fernando

2016-05-23

Silver borotellurite glasses of composition: xAg{sub 2}O-yB{sub 2}O{sub 3}-(100-x-y)TeO{sub 2} (x=20-mol%, y = 0, 10, 20 and 30-mol%) were prepared and characterized by density, X-ray diffraction (XRD), differential scanning calorimetry, and Raman spectroscopy. XRD confirmed the amorphous structure of all samples. Density of glasses decreases while the glass transition temperature increases with increase in B{sub 2}O{sub 3} content from 10 to 30-mol%. Raman study shows that coordination number of Te with oxygen decreases steadily from 3.42 to 3.18 on adding B{sub 2}O{sub 3} due to the transformation of TeO{sub 4} into TeO{sub 3} units.

DSC and Raman studies of silver borotellurite glasses

NASA Astrophysics Data System (ADS)

Kaur, Amandeep; Khanna, Atul; Gonzàlez, Fernando

2016-05-01

Silver borotellurite glasses of composition: xAg2O-yB2O3-(100-x-y)TeO2 (x=20-mol%, y = 0, 10, 20 and 30-mol%) were prepared and characterized by density, X-ray diffraction (XRD), differential scanning calorimetry, and Raman spectroscopy. XRD confirmed the amorphous structure of all samples. Density of glasses decreases while the glass transition temperature increases with increase in B2O3 content from 10 to 30-mol%. Raman study shows that coordination number of Te with oxygen decreases steadily from 3.42 to 3.18 on adding B2O3 due to the transformation of TeO4 into TeO3 units.

[MSW incineration fly ash melting by DSC-DTA].

PubMed

Li, Rundong; Chi, Yong; Li, Shuiqing; Wang, Lei; Yan, Jianhua; Cen, Kefa

2002-07-01

Melting characteristics of two kinds of municipal solid waste incineration(MSWI) fly ash were studied in this paper by high temperature differential scanning calorimetry and differential temperature analysis. MSWI fly ash was considered as hazardous waste because it contains heavy metals and dioxins. The experiments were performed in either N2 or O2 atmosphere in temperature range of 20 degrees C-1450 degrees C at various heating rates. Two different MSW incineration fly ashes used in the experiments were collected from our country and France respectively. The process of fly ash melting exhibits two reactions occurring at temperature ranges of about 480 degrees C-670 degrees C and 1136 degrees C-1231 degrees C, respectively. The latent heat of polymorphic transformation and fusion were approximately 20 kJ/kg and 700 kJ/kg, while the total heat required for melting process was about 1800 kJ/kg. The paper also studied effect of CaO to melting. A heat flux thermodynamic model for fly ash melting was put forward and it agrees well with experimental data.

Asymmetry of righting reflexes in sea turtles and its behavioral correlates.

PubMed

Malashichev, Yegor

2016-04-01

The righting responses, when the animal rights itself over one side of the body after been overturned on the back, are one of the simplest ways to test for laterality, especially in lower vertebrates. In anuran amphibians unilateral preferences in righting responses correlated to the degree of the use of alternating-limb (asynchronous) movements during locomotion. Turtles is one of the underrepresented vertebrate groups in the studies of laterality, while possess also different types of locomotion (with synchronous or asynchronous use of the contralateral limbs), which allows testing the hypothesis on functional relationship between the mode of locomotion and the strength of laterality. We studied two species of sea turtles, Green turtle (Chelonia mydas) and Olive Ridley turtle (Lepidochelys olivacea), which differ from the majority of other representatives of the order in that they mostly utilize synchronous locomotion, when all four limbs move simultaneously in strokes (scratching). In righting response tests turtles demonstrated individual and weak population level laterality, which differed in strength. The Green turtle was less lateralized with the majority of individuals being ambipreferent. The Olive Ridley turtle had a greater number of lateralized individuals and a greater average strength of laterality. Interspecies comparison to land tortoises, which use only asynchronous (alternating-limb) walking (crawling), confirmed the rule found in amphibians: the more asynchronous locomotion is used, the greater is the strength of laterality in righting. Hence, data from turtles and amphibians may represent a phenomenon common for all quadruped vertebrates. We also discuss possible biomechanical and neurological correlates of this evolutionary change in locomotory patterns and lateralization in sea turtles when adapting to sea life. Copyright © 2016 Elsevier Inc. All rights reserved.

In space no one can hear you scream, "That's anatomically inaccurate!"

NASA Astrophysics Data System (ADS)

Ambrogio, O.

2017-12-01

The Alien of the seminal series begun by director Ridley Scott (1979) possesses a fascinating combination of Terran vertebrate and invertebrate characteristics, not to mention a lot of Freudian symbolism. This talk will quickly review the Alien's characteristics, social behavior, and anatomy; make the argument that it is clearly more vertebrate than invertebrate; and describe some of the similarities between real-life organisms' structures and those of an acid-for-blood-bearing creature with a mouth inside a mouth and a complex life cycle. The alarming misuse of genetics and the laws of inheritance in the otherwise excellent fourth film, Alien Resurrection (1997), may or may not be discussed.

The road to JCAHO disease-specific care certification: a step-by-step process log.

PubMed

Morrison, Kathy

2005-01-01

In 2002, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) implemented Disease-Specific Care (DSC) certification. This is a voluntary program in which organizations have their disease management program evaluated by this regulatory agency. Some of the DSC categories are stroke, heart failure, acute MI, diabetes, and pneumonia. The criteria for any disease management program certification are: compliance with consensus-based national standards, effective use of established clinical practice guidelines to manage and optimize care, and an organized approach to performance measurement and improvement activities. Successful accomplishment of DSC certification defines organizations as Centers of Excellence in management of that particular disease. This article will review general guidelines for DSC certification with an emphasis on Primary Stroke Center certification.

"Sticky electrons" transport and interfacial transfer of electrons in the dye-sensitized solar cell.

PubMed

Peter, Laurence

2009-11-17

Dye-sensitized solar cells (DSCs, also known as Gratzel cells) mimic the photosynthetic process by using a sensitizer dye to harvest light energy to generate electrical power. Several functional features of these photochemical devices are unusual, and DSC research offers a rewarding arena in which to test new ideas, new materials, and new methodologies. Indeed, one of the most attractive chemical features of the DSC is that the basic concept can be used to construct a range of devices, replacing individual components with alternative materials. Despite two decades of increasing research activity, however, many aspects of the behavior of electrons in the DSC remain puzzling. In this Account, we highlight current understanding of the processes involved in the functioning of the DSC, with particular emphasis on what happens to the electrons in the mesoporous film following the injection step. The collection of photoinjected electrons appears to involve a random walk process in which electrons move through the network of interconnected titanium dioxide nanoparticles while undergoing frequent trapping and detrapping. During their passage to the cell contact, electrons may be lost by transfer to tri-iodide species in the redox electrolyte that permeates the mesoporous film. Competition between electron collection and back electron transfer determines the performance of a DSC: ideally, all injected electrons should be collected without loss. This Account then goes on to survey recent experimental and theoretical progress in the field, placing particular emphasis on issues that need to be resolved before we can gain a clear picture of how the DSC works. Several important questions about the behavior of "sticky" electrons, those that undergo multiple trapping and detrapping, in the DSC remain unanswered. The most fundamental of these concerns is the nature of the electron traps that appear to dominate the time-dependent photocurrent and photovoltage response of DSCs. The

A study of mercuric iodide near melting using differential scanning calorimetry, Raman spectroscopy and X-ray diffraction

NASA Astrophysics Data System (ADS)

Burger, A.; Morgan, S.; Jiang, H.; Silberman, E.; Schieber, M.; Van Den Berg, L.; Keller, L.; Wagner, C. N. J.

1989-11-01

High-temperature studies of mercuric iodide (HgI2) involving differential scanning calorimetry (DSC), Raman spectroscopy and X-ray powder diffraction have failed to confirm the existence of a red-colored tetragonal high-temperature phase called α'-HgI2 reported by S.N. Toubektsis et al. [J. Appl. Phys. 58 (1988) 2070] using DSC measurements. The multiple DSC peaks near melting reported by Toubektsis are found by the present authors only if the sample is heated in a stainless-steel container. Using a Pyrex container or inserting a platinum foil between the HgI2 and the stainless-steel container yields only one sharp, single DSC peak at the melting point. The nonexistence of the α' phase is confirmed by high-temperature X-ray diffraction and Raman spectroscopy performed in the vicinity of the melting point. These methods clearly, indicate the existence of only the yellow orthorhombic β-HgI2 phase. The experimental high-temperature DSC, Raman and X-ray diffraction data are presented and discussed.

Dye-sensitized solar cells employing a SnO2-TiO2 core-shell structure made by atomic layer deposition.

PubMed

Karlsson, Martin; Jõgi, Indrek; Eriksson, Susanna K; Rensmo, Håkan; Boman, Mats; Boschloo, Gerrit; Hagfeldt, Anders

2013-01-01

This paper describes the synthesis and characterization of core-shell structures, based on SnO2 and TiO2, for use in dye-sensitized solar cells (DSC). Atomic layer deposition is employed to control and vary the thickness of the TiO2 shell. Increasing the TiO2 shell thickness to 2 nm improved the device performance of liquid electrolyte-based DSC from 0.7% to 3.5%. The increase in efficiency originates from a higher open-circuit potential and a higher short-circuit current, as well as from an improvement in the electron lifetime. SnO2-TiO2 core-shell DSC devices retain their photovoltage in darkness for longer than 500 seconds, demonstrating that the electrons are contained in the core material. Finally core-shell structures were used for solid-state DSC applications using the hole transporting material 2,2',7,7',-tetrakis(N, N-di-p-methoxyphenyl-amine)-9,9',-spirofluorene. Similar improvements in device performance were obtained for solid-state DSC devices.

Magnetic resonance imaging in dissociated strabismus complex demonstrates generalized hypertrophy of rectus extraocular muscles.

PubMed

Rajab, Ghada Z; Suh, Soh Youn; Demer, Joseph L

2017-06-01

Dissociated strabismus complex (DSC) is an enigmatic form of strabismus that includes dissociated vertical deviation (DVD) and dissociated horizontal deviation (DHD). We employed magnetic resonance imaging (MRI) to evaluate the extraocular muscles in DSC. We studied 5 patients with DSC and mean age of 25 years (range, 12-42 years), and 15 age-matched, orthotropic control subjects. All patients had DVD; 4 also had DHD. We employed high-resolution, surface coil MRI with thin, 2 mm slices and central target fixation. Volumes of the rectus and superior oblique muscles in the region 12 mm posterior to 4 mm anterior to the globe-optic nerve junction were measured in quasi-coronal planes in central gaze. Patients with DSC had no structural abnormalities of rectus muscles or rectus pulleys or the superior oblique muscle but exhibited modest, statistically significant increased volume of all rectus muscles ranging from 20% for medial rectus to 9% for lateral rectus (P < 0.05). DSC includes various combinations of sursumduction, excycloduction, and abduction not conforming to Hering's law. We have found modest generalized enlargement of all rectus muscles. DSC is associated with generalized rectus extraocular muscle hypertrophy in the absence of other orbital abnormalities. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

A Unified Constitutive Model for Subglacial Till, Part II: Laboratory Tests, Disturbed State Modeling, and Validation for Two Subglacial Tills

NASA Astrophysics Data System (ADS)

Desai, C. S.; Sane, S. M.; Jenson, J. W.; Contractor, D. N.; Carlson, A. E.; Clark, P. U.

2006-12-01

This presentation, which is complementary to Part I (Jenson et al.), describes the application of the Disturbed State Concept (DSC) constitutive model to define the behavior of the deforming sediment (till) underlying glaciers and ice sheets. The DSC includes elastic, plastic, and creep strains, and microstructural changes leading to degradation, failure, and sometimes strengthening or healing. Here, we describe comprehensive laboratory experiments conducted on samples of two regionally significant tills deposited by the Laurentide Ice Sheet: the Tiskilwa Till and Sky Pilot Till. The tests are used to determine the parameters to calibrate the DSC model, which is validated with respect to the laboratory tests by comparing the predictions with test data used to find the parameters, and also comparing them with independent tests not used to find the parameters. Discussion of the results also includes comparison of the DSC model with the classical Mohr-Coulomb model, which has been commonly used for glacial tills. A numerical procedure based on finite element implementation of the DSC is used to simulate an idealized field problem, and its predictions are discussed. Based on these analyses, the unified DSC model is proposed to provide an improved model for subglacial tills compared to other models used commonly, and thus to provide the potential for improved predictions of ice sheet movements.

Homoacetogenesis in Deep-Sea Chloroflexi, as Inferred by Single-Cell Genomics, Provides a Link to Reductive Dehalogenation in Terrestrial Dehalococcoidetes.

PubMed

Sewell, Holly L; Kaster, Anne-Kristin; Spormann, Alfred M

2017-12-19

The deep marine subsurface is one of the largest unexplored biospheres on Earth and is widely inhabited by members of the phylum Chloroflexi In this report, we investigated genomes of single cells obtained from deep-sea sediments of the Peruvian Margin, which are enriched in such Chloroflexi 16S rRNA gene sequence analysis placed two of these single-cell-derived genomes (DscP3 and Dsc4) in a clade of subphylum I Chloroflexi which were previously recovered from deep-sea sediment in the Okinawa Trough and a third (DscP2-2) as a member of the previously reported DscP2 population from Peruvian Margin site 1230. The presence of genes encoding enzymes of a complete Wood-Ljungdahl pathway, glycolysis/gluconeogenesis, a Rhodobacter nitrogen fixation (Rnf) complex, glyosyltransferases, and formate dehydrogenases in the single-cell genomes of DscP3 and Dsc4 and the presence of an NADH-dependent reduced ferredoxin:NADP oxidoreductase (Nfn) and Rnf in the genome of DscP2-2 imply a homoacetogenic lifestyle of these abundant marine Chloroflexi We also report here the first complete pathway for anaerobic benzoate oxidation to acetyl coenzyme A (CoA) in the phylum Chloroflexi (DscP3 and Dsc4), including a class I benzoyl-CoA reductase. Of remarkable evolutionary significance, we discovered a gene encoding a formate dehydrogenase (FdnI) with reciprocal closest identity to the formate dehydrogenase-like protein (complex iron-sulfur molybdoenzyme [CISM], DET0187) of terrestrial Dehalococcoides/Dehalogenimonas spp. This formate dehydrogenase-like protein has been shown to lack formate dehydrogenase activity in Dehalococcoides/Dehalogenimonas spp. and is instead hypothesized to couple HupL hydrogenase to a reductive dehalogenase in the catabolic reductive dehalogenation pathway. This finding of a close functional homologue provides an important missing link for understanding the origin and the metabolic core of terrestrial Dehalococcoides/Dehalogenimonas spp. and of reductive

Conservation hotspots for marine turtle nesting in the United States based on coastal development.

PubMed

Fuentes, Mariana M P B; Gredzens, Christian; Bateman, Brooke L; Boettcher, Ruth; Ceriani, Simona A; Godfrey, Matthew H; Helmers, David; Ingram, Dianne K; Kamrowski, Ruth L; Pate, Michelle; Pressey, Robert L; Radeloff, Volker C

2016-12-01

Coastal areas provide nesting habitat for marine turtles that is critical for the persistence of their populations. However, many coastal areas are highly affected by coastal development, which affects the reproductive success of marine turtles. Knowing the extent to which nesting areas are exposed to these threats is essential to guide management initiatives. This information is particularly important for coastal areas with both high nesting density and dense human development, a combination that is common in the United States. We assessed the extent to which nesting areas of the loggerhead (Caretta caretta), the green (Chelonia mydas), the Kemp's ridley (Lepidochelys kempii), and leatherback turtles (Dermochelys coriacea) in the continental United States are exposed to coastal development and identified conservation hotspots that currently have high reproductive importance and either face high exposure to coastal development (needing intervention), or have low exposure to coastal development, and are good candidates for continued and future protection. Night-time light, housing, and population density were used as proxies for coastal development and human disturbance. About 81.6% of nesting areas were exposed to housing and human population, and 97.8% were exposed to light pollution. Further, most (>65%) of the very high- and high-density nesting areas for each species/subpopulation, except for the Kemp's ridley, were exposed to coastal development. Forty-nine nesting sites were selected as conservation hotspots; of those high-density nesting sites, 49% were sites with no/low exposure to coastal development and the other 51% were exposed to high-density coastal development. Conservation strategies need to account for ~66.8% of all marine turtle nesting areas being on private land and for nesting sites being exposed to large numbers of seasonal residents. © 2016 by the Ecological Society of America.

Identification and quantitation of semi-crystalline microplastics using image analysis and differential scanning calorimetry.

PubMed

Rodríguez Chialanza, Mauricio; Sierra, Ignacio; Pérez Parada, Andrés; Fornaro, Laura

2018-06-01

There are several techniques used to analyze microplastics. These are often based on a combination of visual and spectroscopic techniques. Here we introduce an alternative workflow for identification and mass quantitation through a combination of optical microscopy with image analysis (IA) and differential scanning calorimetry (DSC). We studied four synthetic polymers with environmental concern: low and high density polyethylene (LDPE and HDPE, respectively), polypropylene (PP), and polyethylene terephthalate (PET). Selected experiments were conducted to investigate (i) particle characterization and counting procedures based on image analysis with open-source software, (ii) chemical identification of microplastics based on DSC signal processing, (iii) dependence of particle size on DSC signal, and (iv) quantitation of microplastics mass based on DSC signal. We describe the potential and limitations of these techniques to increase reliability for microplastic analysis. Particle size demonstrated to have particular incidence in the qualitative and quantitative performance of DSC signals. Both, identification (based on characteristic onset temperature) and mass quantitation (based on heat flow) showed to be affected by particle size. As a result, a proper sample treatment which includes sieving of suspended particles is particularly required for this analytical approach.

A calorimetric study of precipitation in aluminum alloy 2219

NASA Astrophysics Data System (ADS)

Papazian, John M.

1981-02-01

Precipitate microstructures in aluminum alloy 2219 were characterized using transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The DSC signatures of individual precipitate phases were established by comparing the DSC and TEM results from samples that had been aged such that only one precipitate phase was present. These signatures were then used to analyze the commercial tempers. It was found that DSC could readily distinguish between the T3, T4, T6, T8 and O tempers but could not distinguish amongst T81, T851 and T87. Small amounts of plastic deformation between solution treatment and aging had a significant effect on the thermograms. Aging experiments at 130 and 190 °C showed that the aging sequence and DSC response of this alloy were similar to those of pure Al-Cu when the increased copper content is taken into account. Further aging experiments at temperatures between room temperature and 130 °C showed pronounced changes of the GP zone dissolution peak as a function of aging conditions. These changes were found to be related to the effect of GP zone size on the metastable phase boundary and on the GP zone dissolution kinetics.

A Differential Scanning Calorimetry Method for Construction of Continuous Cooling Transformation Diagram of Blast Furnace Slag

NASA Astrophysics Data System (ADS)

Gan, Lei; Zhang, Chunxia; Shangguan, Fangqin; Li, Xiuping

2012-06-01

The continuous cooling crystallization of a blast furnace slag was studied by the application of the differential scanning calorimetry (DSC) method. A kinetic model describing the correlation between the evolution of the degree of crystallization with time was obtained. Bulk cooling experiments of the molten slag coupled with numerical simulation of heat transfer were conducted to validate the results of the DSC methods. The degrees of crystallization of the samples from the bulk cooling experiments were estimated by means of the X-ray diffraction (XRD) and the DSC method. It was found that the results from the DSC cooling and bulk cooling experiments are in good agreement. The continuous cooling transformation (CCT) diagram of the blast furnace slag was constructed according to crystallization kinetic model and experimental data. The obtained CCT diagram characterizes with two crystallization noses at different temperature ranges.

Underwater sightings of sea turtles in the northern Gulf of Mexico. Final report

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

Rosman, I.; Boland, G.S.; Martin, L.

1987-10-01

Between 1975 and 1985, eight scientific studies were conducted in the northern Gulf of Mexico. The purpose here was to review the data collected from all eight studies for information concerning underwater sightings of sea turtles. Records of 1,024 scuba dives, 909 hours of underwater video and submersible observations, and some 1,500 days of time-lapse photographic observations were compiled from published reports, data logs, and photographic material. The effort yielded 268 verifiable underwater sightings of sea turtles, 231 of which came from time-lapse cameras. The majority of sightings that could be identified by species were of loggerheads. Other species sightedmore » included three leatherbacks and one Kemp's Ridley.« less

Lipids and proteins in the Rathke's gland secretions of the North American mud turtle (Kinosternon subrubrum)

USGS Publications Warehouse

Seifert, W.E.; Gotte, S.W.; Leto, T.L.; Weldon, P.J.

1994-01-01

Lipids and proteins in the Rathke's gland secretions of the North American mud turtle (Kinosternon subrubrum, Kinosternidae) were analyzed by gas chromatography-mass spectrometry (GC-MS) and SDS-polyacrylamide gel electrophoresis (SDS-PAGE), respectively. Analysis by GC-MS indicates 2,3-dihydroxypropanal and C3–C24 free or esterified fatty acids. Analysis by SDS-PAGE indicates a major protein component with an approximate molecular mass of 60 kDa and minor components ranging from ca. 23 to 34 kDa. The major component of K. subrubrum glandular secretions exhibits a mobility that matches that of the Kemp's ridley sea turtle (Lepidochelys kempi, Cheloniidae), suggesting that these proteins are evolutionarily conserved.

77 FR 42498 - Information Collection(s) Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-19

...: Section 80.103, Digital Selective Calling (DSC) Operating Procedures--Maritime Mobile Identity (MMSI...: Individuals or households; business or other for- profit entities and Federal Government. Number of... Marine VHF radios with Digital Selective Calling (DSC) capability in this collection. The licensee...

A study of the homogeneity and deviations from stoichiometry in mercuric iodide

NASA Astrophysics Data System (ADS)

Burger, A.; Morgan, S.; He, C.; Silberman, E.; van den Berg, L.; Ortale, C.; Franks, L.; Schieber, M.

1990-01-01

We have been able to determine the deviations from stoichiometry of mercuric iodide (HgI 2) by using differential scanning calorimetry (DSC). Mercury excess or iodine deficiency in mercuric iodide can be evaluated from the eutectic melting of α-Hgl 2-Hg 2I 2 at 235 °C, which appears as an additional peak in DSC thermograms. I 2 excess can be found from the existence of the I 2-α-HgI 2 eutectic melting at 103°C. An additional DSC peak appears in some samples around 112°C, that could be explained by the presence of iodine inclusions. Using resonance fluorescence spectroscopy (RFS) we have been able to determine the presence of free I 2 that is released by samples during the heating at 120 °C (crystal growth temperature), thus giving additional support to the above DSC results.

Religiousness, Spirituality, and Salivary Cortisol in Breast Cancer Survivorship: A Pilot Study.

PubMed

Hulett, Jennifer M; Armer, Jane M; Leary, Emily; Stewart, Bob R; McDaniel, Roxanne; Smith, Kandis; Millspaugh, Rami; Millspaugh, Joshua

Psychoneuroimmunological theory suggests a physiological relationship exists between stress, psychosocial-behavioral factors, and neuroendocrine-immune outcomes; however, evidence has been limited. The primary aim of this pilot study was to determine feasibility and acceptability of a salivary cortisol self-collection protocol with a mail-back option for breast cancer survivors. A secondary aim was to examine relationships between religiousness/spirituality (R/S), perceptions of health, and diurnal salivary cortisol (DSC) as a proxy measure for neuroendocrine activity. This was an observational, cross-sectional study. Participants completed measures of R/S, perceptions of health, demographics, and DSC. The sample was composed of female breast cancer survivors (n = 41). Self-collection of DSC using a mail-back option was feasible; validity of mailed salivary cortisol biospecimens was established. Positive spiritual beliefs were the only R/S variable associated with the peak cortisol awakening response (rs = 0.34, P = .03). Poorer physical health was inversely associated with positive spiritual experiences and private religious practices. Poorer mental health was inversely associated with spiritual coping and negative spiritual experiences. Feasibility, validity, and acceptability of self-collected SDC biospecimens with an optional mail-back protocol (at moderate temperatures) were demonstrated. Positive spiritual beliefs were associated with neuroendocrine-mediated peak cortisol awakening response activity; however, additional research is recommended. Objective measures of DSC sampling that include enough collection time points to assess DSC parameters would increase the rigor of future DSC measurement. Breast cancer survivors may benefit from nursing care that includes spiritual assessment and therapeutic conversations that support positive spiritual beliefs.

Oxidative induction time -- A review of DSC experimental effects

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

Blaine, R.L.; Lundgren, C.J.; Harris, M.B.

1997-12-31

Over the past several years, a number of ASTM committees have explored a wide variety of experimental parameters affecting the oxidative induction time (OIT) test method in an attempt to improve its intra- and inter-laboratory precision. These studies have identified test temperature precision as a key parameter affecting OIT precision. Other parameters of importance are oxygen flow rate, specimen size, specimen pan type, oxygen pressure and catalyst effects. The work of Kuck, Bowmer, Riga, Tikuisis and Thomas are reviewed as well as the collective work of ASTM Committees E37, D2, D9 and D35.

47 CFR 80.225 - Requirements for selective calling equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... manufacture, importation, sale or installation of non-portable DSC equipment that does not comply with either..., 2011. (5) The manufacture, importation, or sale of handheld, portable DSC equipment that does not... to establish or maintain communications provided that: (i) These signalling techniques are not used...

Differential scanning calorimetry: An invaluable tool for a detailed thermodynamic characterization of macromolecules and their interactions

PubMed Central

Chiu, Michael H.; Prenner, Elmar J.

2011-01-01

Differential Scanning Calorimetry (DSC) is a highly sensitive technique to study the thermotropic properties of many different biological macromolecules and extracts. Since its early development, DSC has been applied to the pharmaceutical field with excipient studies and DNA drugs. In recent times, more attention has been applied to lipid-based drug delivery systems and drug interactions with biomimetic membranes. Highly reproducible phase transitions have been used to determine values, such as, the type of binding interaction, purity, stability, and release from a drug delivery mechanism. This review focuses on the use of DSC for biochemical and pharmaceutical applications. PMID:21430954

An investigation of indomethacin-nicotinamide cocrystal formation induced by thermal stress in the solid or liquid state.

PubMed

Lin, Hong-Liang; Zhang, Gang-Chun; Huang, Yu-Ting; Lin, Shan-Yang

2014-08-01

The impact of thermal stress on indomethacin (IMC)-nicotinamide (NIC) cocrystal formation with or without neat cogrinding was investigated using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) microspectroscopy, and simultaneous DSC-FTIR microspectroscopy in the solid or liquid state. Different evaporation methods for preparing IMC-NIC cocrystals were also compared. The results indicated that even after cogrinding for 40 min, the FTIR spectra for all IMC-NIC ground mixtures were superimposable on the FTIR spectra of IMC and NIC components, suggesting there was no cocrystal formation between IMC and NIC after cogrinding. However, these IMC-NIC ground mixtures appear to easily undergo cocrystal formation after the application of DSC determination. Under thermal stress induced by DSC, the amount of cocrystal formation increased with increasing cogrinding time. Moreover, simultaneous DSC-FTIR microspectroscopy was a useful one-step technique to induce and clarify the thermal-induced stepwise mechanism of IMC-NIC cocrystal formation from the ground mixture in real time. Different solvent evaporation rates induced by thermal stress significantly influenced IMC-NIC cocrystal formation in the liquid state. In particular, microwave heating may promote IMC-NIC cocrystal formation in a short time. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

7 CFR 1717.850 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Earned Ratio (TIER), Debt Service Coverage (DSC), and other case-specific economic and financial factors; (ii) The variability and uncertainty of future revenues, costs, margins, TIER, DSC, and other case... construction work orders and other records, all moneys disbursed from the separate subaccount during the period...

Sorting of a multi-subunit ubiquitin ligase complex in the endolysosome system

PubMed Central

Yang, Xi; Arines, Felichi Mae; Zhang, Weichao

2018-01-01

The yeast Dsc E3 ligase complex has long been recognized as a Golgi-specific protein ubquitination system. It shares a striking sequence similarity to the Hrd1 complex that plays critical roles in the ER-associated degradation pathway. Using biochemical purification and mass spectrometry, we identified two novel Dsc subunits, which we named as Gld1 and Vld1. Surprisingly, Gld1 and Vld1 do not coexist in the same complex. Instead, they compete with each other to form two functionally independent Dsc subcomplexes. The Vld1 subcomplex takes the AP3 pathway to reach the vacuole membrane, whereas the Gld1 subcomplex travels through the VPS pathway and is cycled between Golgi and endosomes by the retromer. Thus, instead of being Golgi-specific, the Dsc complex can regulate protein levels at three distinct organelles, namely Golgi, endosome, and vacuole. Our study provides a novel model of achieving multi-tasking for transmembrane ubiquitin ligases with interchangeable trafficking adaptors. PMID:29355480

Ionic liquids: differential scanning calorimetry as a new indirect method for determination of vaporization enthalpies.

PubMed

Verevkin, Sergey P; Emel'yanenko, Vladimir N; Zaitsau, Dzmitry H; Ralys, Ricardas V; Schick, Christoph

2012-04-12

Differential scanning calorimetry (DSC) has been used to measure enthalpies of synthesis reactions of the 1-alkyl-3-methylimidazolium bromide [C(n)mim][Br] ionic liquids from 1-methylimidazole and n-alkyl bromides (with n = 4, 5, 6, 7, and 8). The optimal experimental conditions have been elaborated. Enthalpies of formation of these ionic liquids in the liquid state have been determined using the DSC results according to the Hess Law. The ideal-gas enthalpies of formation of [C(n)mim][Br] were calculated using the methods of quantum chemistry. They were used together with the DSC results to derive indirectly the enthalpies of vaporization of the ionic liquids under study. In order to validate the indirect determination, the experimental vaporization enthalpy of [C(4)mim][Br] was measured by using a quartz crystal microbalance (QCM). The combination of reaction enthalpy measurements by DSC with modern high-level first-principles calculations opens valuable indirect thermochemical options to obtain values of vaporization enthalpies of ionic liquids.

Psychological stress during exercise: cardiorespiratory and hormonal responses.

PubMed

Webb, Heather E; Weldy, Michael L; Fabianke-Kadue, Emily C; Orndorff, G R; Kamimori, Gary H; Acevedo, Edmund O

2008-12-01

The purpose of this study was to examine the cardiorespiratory (CR) and stress hormone responses to a combined physical and mental stress. Eight participants (VO2(max) = 41.24 +/- 6.20 ml kg(-1) min(-1)) completed two experimental conditions, a treatment condition including a 37 min ride at 60% of VO2(max) with participants responding to a computerized mental challenge dual stress condition (DSC) and a control condition of the same duration and intensity without the mental challenge exercise alone condition (EAC). Significant interactions across time were found for CR responses, with heart rate, ventilation, and respiration rate demonstrating higher increases in the DSC. Additionally, norepinephrine was significantly greater in the DSC at the end of the combined challenge. Furthermore, cortisol area-under-the-curve (AUC) was also significantly elevated during the DSC. These results demonstrate that a mental challenge during exercise can exacerbate the stress response, including the release of hormones that have been linked to negative health consequences (cardiovascular, metabolic, autoimmune illnesses).

Study on Synthesis of Thoreau-modified 3, 5-Dimethyl-Thioltoluenediamine Used as Epoxy Resin Curing Agent and Its Performance

NASA Astrophysics Data System (ADS)

Peng, Yongli; Xiao, Wenzheng

2017-06-01

A novel curing agent Thoreau modified 3, 5-Dimethyl-thioltoluenediamine was synthesized and its molecular structure was characterized by FTIR and DSC. The curing kinetics of a high toughness and low volume shrinkage ratio epoxy system (modified DMTDA/DGEBA) was studied by differential scanning calorimetry (DSC) under noni so thermal conditions. The data were fitted to an order model and autocatalytic model respectively. The results indicate that in order model deviates significantly from experimental data. Malik’s method was used to prove that the curing kinetics of the system concerned follow single-step autocatalytic model, and a “single-point model-free” approach was employed to calculate meaningful kinetic parameters. The DSC curves derived from autocatalytic model gave satisfactory agreement with that of experiment in the range 5K/min∼25K/min. As the heating rate increased, the predicted DSC curves deviated from experimental curves, and the total exothermic enthalpy declined owing to the transition of competition relationship between kinetics control and diffusion control.

Non-resonant dynamic stark control of vibrational motion with optimized laser pulses

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

Thomas, Esben F.; Henriksen, Niels E.

2016-06-28

The term dynamic Stark control (DSC) has been used to describe methods of quantum control related to the dynamic Stark effect, i.e., a time-dependent distortion of energy levels. Here, we employ analytical models that present clear and concise interpretations of the principles behind DSC. Within a linearly forced harmonic oscillator model of vibrational excitation, we show how the vibrational amplitude is related to the pulse envelope, and independent of the carrier frequency of the laser pulse, in the DSC regime. Furthermore, we shed light on the DSC regarding the construction of optimal pulse envelopes — from a time-domain as wellmore » as a frequency-domain perspective. Finally, in a numerical study beyond the linearly forced harmonic oscillator model, we show that a pulse envelope can be constructed such that a vibrational excitation into a specific excited vibrational eigenstate is accomplished. The pulse envelope is constructed such that high intensities are avoided in order to eliminate the process of ionization.« less

Dynamic system classifier.

PubMed

Pumpe, Daniel; Greiner, Maksim; Müller, Ewald; Enßlin, Torsten A

2016-07-01

Stochastic differential equations describe well many physical, biological, and sociological systems, despite the simplification often made in their derivation. Here the usage of simple stochastic differential equations to characterize and classify complex dynamical systems is proposed within a Bayesian framework. To this end, we develop a dynamic system classifier (DSC). The DSC first abstracts training data of a system in terms of time-dependent coefficients of the descriptive stochastic differential equation. Thereby the DSC identifies unique correlation structures within the training data. For definiteness we restrict the presentation of the DSC to oscillation processes with a time-dependent frequency ω(t) and damping factor γ(t). Although real systems might be more complex, this simple oscillator captures many characteristic features. The ω and γ time lines represent the abstract system characterization and permit the construction of efficient signal classifiers. Numerical experiments show that such classifiers perform well even in the low signal-to-noise regime.

Calorimetric evidence for two distinct molecular packing arrangements in stable glasses of indomethacin.

PubMed

Kearns, Kenneth L; Swallen, Stephen F; Ediger, M D; Sun, Ye; Yu, Lian

2009-02-12

Indomethacin glasses of varying stabilities were prepared by physical vapor deposition onto substrates at 265 K. Enthalpy relaxation and the mobility onset temperature were assessed with differential scanning calorimetry (DSC). Quasi-isothermal temperature-modulated DSC was used to measure the reversing heat capacity during annealing above the glass transition temperature Tg. At deposition rates near 8 A/s, scanning DSC shows two enthalpy relaxation peaks and quasi-isothermal DSC shows a two-step change in the reversing heat capacity. We attribute these features to two distinct local packing structures in the vapor-deposited glass, and this interpretation is supported by the strong correlation between the two calorimetric signatures of the glass to liquid transformation. At lower deposition rates, a larger fraction of the sample is prepared in the more stable local packing. The transformation of the vapor-deposited glasses into the supercooled liquid above Tg is exceedingly slow, as much as 4500 times slower than the structural relaxation time of the liquid.

Effect of additives on mineral trioxide aggregate setting reaction product formation.

PubMed

Zapf, Angela M; Chedella, Sharath C V; Berzins, David W

2015-01-01

Mineral trioxide aggregate (MTA) sets via hydration of calcium silicates to yield calcium silicate hydrates and calcium hydroxide (Ca[OH]2). However, a drawback of MTA is its long setting time. Therefore, many additives have been suggested to reduce the setting time. The effect those additives have on setting reaction product formation has been ignored. The objective was to examine the effect additives have on MTA's setting time and setting reaction using differential scanning calorimetry (DSC). MTA powder was prepared with distilled water (control), phosphate buffered saline, 5% calcium chloride (CaCl2), 3% sodium hypochlorite (NaOCl), or lidocaine in a 3:1 mixture and placed in crucibles for DSC evaluation. The setting exothermic reactions were evaluated at 37°C for 8 hours to determine the setting time. Separate samples were stored and evaluated using dynamic DSC scans (37°C→640°C at10°C/min) at 1 day, 1 week, 1 month, and 3 months (n = 9/group/time). Dynamic DSC quantifies the reaction product formed from the amount of heat required to decompose it. Thermographic peaks were integrated to determine enthalpy, which was analyzed with analysis of variance/Tukey test (α = 0.05). Isothermal DSC identified 2 main exothermal peaks occurring at 44 ± 12 and 343 ± 57 minutes for the control. Only the CaCl2 additive was an accelerant, which was observed by a greater exothermic peak at 101 ± 11 minutes, indicating a decreased setting time. The dynamic DSC scans produced an endothermic peak around 450°C-550°C attributed to Ca(OH)2 decomposition. The use of a few additives (NaOCl and lidocaine) resulted in significantly less Ca(OH)2 product formation. DSC was used to discriminate calcium hydroxide formation in MTA mixed with various additives and showed NaOCl and lidocaine are detrimental to MTA reaction product formation, whereas CaCl2 accelerated the reaction. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The Structure of Mother-Child Play: Young Children with Down Syndrome and Typically Developing Children.

ERIC Educational Resources Information Center

Roach, Mary A.; Barratt, Marguerite Stevenson; Miller, Jon F.; Leavitt, Lewis A.

1998-01-01

Compared mothers' play with infants with Down syndrome (DSC) and typically developing children (TDC) matched for mental or chronological age. Found that TDC mothers exhibited more object demonstrations with their developmentally younger children, who showed less object play. DSC mothers were more directive and supportive than mothers of younger…

The Optimal Employment of a Deep Seaweb Acoustic Network for Submarine Communications at Speed and Depth Using a Defender-Attacker-Defender Model

DTIC Science & Technology

2013-09-01

Figure 17. Reliable acoustic paths from a deep source to shallow receivers (From Urick 1983... Urick 1983). ..................................................................28 Figure 19. Computer generated ray diagram of the DSC for a source...near the axis. Reflected rays are omitted (From Urick 1983). .........................................29 Figure 20. Worldwide DSC axis depths in

High-Speed Digital Scan Converter for High-Frequency Ultrasound Sector Scanners

PubMed Central

Chang, Jin Ho; Yen, Jesse T.; Shung, K. Kirk

2008-01-01

This paper presents a high-speed digital scan converter (DSC) capable of providing more than 400 images per second, which is necessary to examine the activities of the mouse heart whose rate is 5–10 beats per second. To achieve the desired high-speed performance in cost-effective manner, the DSC developed adopts a linear interpolation algorithm in which two nearest samples to each object pixel of a monitor are selected and only angular interpolation is performed. Through computer simulation with the Field II program, its accuracy was investigated by comparing it to that of bilinear interpolation known as the best algorithm in terms of accuracy and processing speed. The simulation results show that the linear interpolation algorithm is capable of providing an acceptable image quality, which means that the difference of the root mean square error (RMSE) values of the linear and bilinear interpolation algorithms is below 1 %, if the sample rate of the envelope samples is at least four times higher than the Nyquist rate for the baseband component of echo signals. The designed DSC was implemented with a single FPGA (Stratix EP1S60F1020C6, Altera Corporation, San Jose, CA) on a DSC board that is a part of a high-speed ultrasound imaging system developed. The temporal and spatial resolutions of the implemented DSC were evaluated by examining its maximum processing time with a time stamp indicating when an image is completely formed and wire phantom testing, respectively. The experimental results show that the implemented DSC is capable of providing images at the rate of 400 images per second with negligible processing error. PMID:18430449

Synthesis of plutonium trifluoride by hydro-fluorination and novel thermodynamic data for the PuF3-LiF system

NASA Astrophysics Data System (ADS)

Tosolin, A.; Souček, P.; Beneš, O.; Vigier, J.-F.; Luzzi, L.; Konings, R. J. M.

2018-05-01

PuF3 was synthetized by hydro-fluorination of PuO2 and subsequent reduction of the product by hydrogenation. The obtained PuF3 was analysed by X-Ray Diffraction (XRD) and found phase-pure. High purity was also confirmed by the melting point analysis using Differential Scanning Calorimetry (DSC). PuF3 was then used for thermodynamic assessment of the PuF3-LiF system. Phase equilibrium points and enthalpy of fusion of the eutectic composition were measured by DSC. XRD analyses of selected samples after DSC measurement confirm that after solidification from the liquid, the system returns to a mixture of LiF and PuF3.

Analytical solutions by squeezing to the anisotropic Rabi model in the nonperturbative deep-strong-coupling regime

NASA Astrophysics Data System (ADS)

Zhang, Yu-Yu; Chen, Xiang-You

2017-12-01

An unexplored nonperturbative deep strong coupling (npDSC) achieved in superconducting circuits has been studied in the anisotropic Rabi model by the generalized squeezing rotating-wave approximation. Energy levels are evaluated analytically from the reformulated Hamiltonian and agree well with numerical ones in a wide range of coupling strength. Such improvement ascribes to deformation effects in the displaced-squeezed state presented by the squeezed momentum variance, which are omitted in previous displaced states. The atom population dynamics confirms the validity of our approach for the npDSC strength. Our approach offers the possibility to explore interesting phenomena analytically in the npDSC regime in qubit-oscillator experiments.

Determining the critical relative humidity at which the glassy to rubbery transition occurs in polydextrose using an automatic water vapor sorption instrument.

PubMed

Yuan, Xiaoda; Carter, Brady P; Schmidt, Shelly J

2011-01-01

Similar to an increase in temperature at constant moisture content, water vapor sorption by an amorphous glassy material at constant temperature causes the material to transition into the rubbery state. However, comparatively little research has investigated the measurement of the critical relative humidity (RHc) at which the glass transition occurs at constant temperature. Thus, the central objective of this study was to investigate the relationship between the glass transition temperature (Tg), determined using thermal methods, and the RHc obtained using an automatic water vapor sorption instrument. Dynamic dewpoint isotherms were obtained for amorphous polydextrose from 15 to 40 °C. RHc was determined using an optimized 2nd-derivative method; however, 2 simpler RHc determination methods were also tested as a secondary objective. No statistical difference was found between the 3 RHc methods. Differential scanning calorimetry (DSC) Tg values were determined using polydextrose equilibrated from 11.3% to 57.6% RH. Both standard DSC and modulated DSC (MDSC) methods were employed, since some of the polydextrose thermograms exhibited a physical aging peak. Thus, a tertiary objective was to compare Tg values obtained using 3 different methods (DSC first scan, DSC rescan, and MDSC), to determine which method(s) yielded the most accurate Tg values. In general, onset and midpoint DSC first scan and MDSC Tg values were similar, whereas onset and midpoint DSC rescan values were different. State diagrams of RHc and experimental temperature and Tg and %RH were compared. These state diagrams, though obtained via very different methods, showed relatively good agreement, confirming our hypothesis that water vapor sorption isotherms can be used to directly detect the glassy to rubbery transition. Practical Application: The food polymer science (FPS) approach, pioneered by Slade and Levine, is being successfully applied in the food industry for understanding, improving, and

47 CFR 80.179 - Unattended operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... DSC in accordance with ITU-R Recommendation M.493-11, “Digital Selective-calling System for Use in the...., Washington, DC (Reference Information Center) or at the National Archives and Records Administration (NARA... condition related to ship safety. (3) The “ROUTINE” DSC category must be used. (4) Communications must be...

Thermal Analysis of Plastics

ERIC Educational Resources Information Center

D'Amico, Teresa; Donahue, Craig J.; Rais, Elizabeth A.

2008-01-01

This lab experiment illustrates the use of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) in the measurement of polymer properties. A total of seven exercises are described. These are dry exercises: students interpret previously recorded scans. They do not perform the experiments. DSC was used to determine the…

Among the Few at Deep Springs College: Assessing a Seven-Decade Experiment in Liberal Education.

ERIC Educational Resources Information Center

Newell, L. Jackson

1982-01-01

Describes the origins and characteristics of Deep Springs College (DSC), which since 1917 has teamed liberal arts instruction with the physical labor of running a cattle ranch. Uses alumni survey responses to assess the long-term effects of attending DSC. Examines paradoxes inherent in the school and its future prospects. (DMM)

Trace elements in blood of sea turtles Lepidochelys olivacea in the Gulf of California, Mexico.

PubMed

Zavala-Norzagaray, A A; Ley-Quiñónez, C P; Espinosa-Carreón, T L; Canizalez-Román, A; Hart, C E; Aguirre, A A

2014-11-01

This study determined the concentrations of heavy metals in blood collected from Pacific Ridley sea turtles (Lepidochelys olivacea) inhabiting the coast of Guasave, Mexico, in the Gulf of California. The highest reported metal concentration in blood was Zn, followed by Se. Of nonessential toxic metals, As was reported in higher percentage compared to Cd. The concentrations of metals detected were present as follows: Zn > Se > Mn > As > Ni > Cd > Cu. Cd concentration in blood is higher in our population in comparison with other populations of L. olivacea, and even higher in other species of sea turtles. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements, and is easily accessible and nonlethal for sea turtles.

Crystallization processes in Ge{sub 2}Sb{sub 2}Se{sub 4}Te glass

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

Svoboda, Roman, E-mail: roman.svoboda@upce.cz; Bezdička, Petr; Gutwirth, Jan

2015-01-15

Highlights: • Crystallization kinetics of Ge{sub 2}Sb{sub 2}Se{sub 4}Te glass was studied in dependence on particle size by DSC. • All studied fractions were described in terms of the SB autocatalytic model. • Relatively high amount of Te enhances manifestation of bulk crystallization mechanisms. • XRD analysis of samples crystallized under different conditions showed correlation with DSC data. • XRD analysis revealed a new crystallization mechanism indistinguishable by DSC. - Abstract: Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis were used to study crystallization in Ge{sub 2}Sb{sub 2}Se{sub 4}Te glass under non-isothermal conditions as a function of the particlemore » size. The crystallization kinetics was described in terms of the autocatalytic Šesták–Berggren model. An extensive discussion of all aspects of a full-scale kinetic study of a crystallization process was undertaken. Dominance of the crystallization process originating from mechanically induced strains and heterogeneities was confirmed. Substitution of Se by Te was found to enhance the manifestation of the bulk crystallization mechanisms (at the expense of surface crystallization). The XRD analysis showed significant dependence of the crystalline structural parameters on the crystallization conditions (initial particle size of the glassy grains and applied heating rate). Based on this information, a new microstructural crystallization mechanism, indistinguishable by DSC, was proposed.« less

The Multidimensional Influence of Acculturation on Digit Symbol-Coding and Wisconsin Card Sorting Test in Hispanics.

PubMed

Krch, Denise; Lequerica, Anthony; Arango-Lasprilla, Juan Carlos; Rogers, Heather L; DeLuca, John; Chiaravalloti, Nancy D

2015-01-01

The purpose of the current study was to evaluate the relative contribution of acculturation to two tests of nonverbal test performance in Hispanics. This study compared 40 Hispanic and 20 non-Hispanic whites on Digit Symbol-Coding (DSC) and the Wisconsin Card Sorting Test (WCST) and evaluated the relative contribution of the various acculturation components to cognitive test performance in the Hispanic group. Hispanics performed significantly worse on DSC and WCST relative to non-Hispanic whites. Multiple regressions conducted within the Hispanic group revealed that language use uniquely accounted for 11.0% of the variance on the DSC, 18.8% of the variance on WCST categories completed, and 13.0% of the variance in perseverative errors on the WCST. Additionally, years of education in the United States uniquely accounted for 14.9% of the variance in DSC. The significant impact of acculturation on DSC and WCST lends support that nonverbal cognitive tests are not necessarily culture free. The differential contribution of acculturation proxies highlights the importance of considering these separate components when interpreting performance on neuropsychological tests in clinical and research settings. Factors, such as the country where education was received, may in fact be more meaningful information than the years of education of education attained. Thus, acculturation should be considered an important factor in any cognitive evaluation of culturally diverse individuals.

Social Media Impact of the Food and Drug Administration's Drug Safety Communication Messaging About Zolpidem: Mixed-Methods Analysis

PubMed Central

Sinha, Michael S; Freifeld, Clark C; Brownstein, John S; Donneyong, Macarius M; Rausch, Paula; Lappin, Brian M; Zhou, Esther H; Dal Pan, Gerald J; Pawar, Ajinkya M; Hwang, Thomas J; Avorn, Jerry

2018-01-01

Background The Food and Drug Administration (FDA) issues drug safety communications (DSCs) to health care professionals, patients, and the public when safety issues emerge related to FDA-approved drug products. These safety messages are disseminated through social media to ensure broad uptake. Objective The objective of this study was to assess the social media dissemination of 2 DSCs released in 2013 for the sleep aid zolpidem. Methods We used the MedWatcher Social program and the DataSift historic query tool to aggregate Twitter and Facebook posts from October 1, 2012 through August 31, 2013, a period beginning approximately 3 months before the first DSC and ending 3 months after the second. Posts were categorized as (1) junk, (2) mention, and (3) adverse event (AE) based on a score between –0.2 (completely unrelated) to 1 (perfectly related). We also looked at Google Trends data and Wikipedia edits for the same time period. Google Trends search volume is scaled on a range of 0 to 100 and includes “Related queries” during the relevant time periods. An interrupted time series (ITS) analysis assessed the impact of DSCs on the counts of posts with specific mention of zolpidem-containing products. Chow tests for known structural breaks were conducted on data from Twitter, Facebook, and Google Trends. Finally, Wikipedia edits were pulled from the website’s editorial history, which lists all revisions to a given page and the editor’s identity. Results In total, 174,286 Twitter posts and 59,641 Facebook posts met entry criteria. Of those, 16.63% (28,989/174,286) of Twitter posts and 25.91% (15,453/59,641) of Facebook posts were labeled as junk and excluded. AEs and mentions represented 9.21% (16,051/174,286) and 74.16% (129,246/174,286) of Twitter posts and 5.11% (3,050/59,641) and 68.98% (41,138/59,641) of Facebook posts, respectively. Total daily counts of posts about zolpidem-containing products increased on Twitter and Facebook on the day of the first DSC

47 CFR 80.1087 - Ship radio equipment-Sea area A1.

Code of Federal Regulations, 2010 CFR

2010-10-01

... which the ship is normally navigated, operating either: (1) On VHF using DSC; or (2) Through the polar...; or (4) On HF using DSC; or (5) Through the INMARSAT geostationary satellite service if within... communication. (b) The VHF radio installation, required by § 80.1085(a)(1), must also be capable of transmitting...

47 CFR 80.1087 - Ship radio equipment-Sea area A1.

Code of Federal Regulations, 2011 CFR

2011-10-01

... which the ship is normally navigated, operating either: (1) On VHF using DSC; or (2) Through the polar...; or (4) On HF using DSC; or (5) Through the INMARSAT geostationary satellite service if within... communication. (b) The VHF radio installation, required by § 80.1085(a)(1), must also be capable of transmitting...

Learning from adaptive neural dynamic surface control of strict-feedback systems.

PubMed

Wang, Min; Wang, Cong

2015-06-01

Learning plays an essential role in autonomous control systems. However, how to achieve learning in the nonstationary environment for nonlinear systems is a challenging problem. In this paper, we present learning method for a class of n th-order strict-feedback systems by adaptive dynamic surface control (DSC) technology, which achieves the human-like ability of learning by doing and doing with learned knowledge. To achieve the learning, this paper first proposes stable adaptive DSC with auxiliary first-order filters, which ensures the boundedness of all the signals in the closed-loop system and the convergence of tracking errors in a finite time. With the help of DSC, the derivative of the filter output variable is used as the neural network (NN) input instead of traditional intermediate variables. As a result, the proposed adaptive DSC method reduces greatly the dimension of NN inputs, especially for high-order systems. After the stable DSC design, we decompose the stable closed-loop system into a series of linear time-varying perturbed subsystems. Using a recursive design, the recurrent property of NN input variables is easily verified since the complexity is overcome using DSC. Subsequently, the partial persistent excitation condition of the radial basis function NN is satisfied. By combining a state transformation, accurate approximations of the closed-loop system dynamics are recursively achieved in a local region along recurrent orbits. Then, the learning control method using the learned knowledge is proposed to achieve the closed-loop stability and the improved control performance. Simulation studies are performed to demonstrate the proposed scheme can not only reuse the learned knowledge to achieve the better control performance with the faster tracking convergence rate and the smaller tracking error but also greatly alleviate the computational burden because of reducing the number and complexity of NN input variables.

Structural basis of host recognition and biofilm formation by Salmonella Saf pili

PubMed Central

2017-01-01

Pili are critical in host recognition, colonization and biofilm formation during bacterial infection. Here, we report the crystal structures of SafD-dsc and SafD-SafA-SafA (SafDAA-dsc) in Saf pili. Cell adherence assays show that SafD and SafA are both required for host recognition, suggesting a poly-adhesive mechanism for Saf pili. Moreover, the SafDAA-dsc structure, as well as SAXS characterization, reveals an unexpected inter-molecular oligomerization, prompting the investigation of Saf-driven self-association in biofilm formation. The bead/cell aggregation and biofilm formation assays are used to demonstrate the novel function of Saf pili. Structure-based mutants targeting the inter-molecular hydrogen bonds and complementary architecture/surfaces in SafDAA-dsc dimers significantly impaired the Saf self-association activity and biofilm formation. In summary, our results identify two novel functions of Saf pili: the poly-adhesive and self-associating activities. More importantly, Saf-Saf structures and functional characterizations help to define a pili-mediated inter-cellular oligomerizaiton mechanism for bacterial aggregation, colonization and ultimate biofilm formation. PMID:29125121

Thermal analysis of hydroxypropylmethylcellulose and methylcellulose: powders, gels and matrix tablets.

PubMed

Ford, J L

1999-03-15

This review focuses on the thermal analysis of hydroxypropylmethylcellulose (HPMC) and methylcellulose. Differential scanning calorimetry (DSC) of their powders is used to determine temperatures of moisture loss (in conjunction with thermogravimetric analysis) and glass transition temperatures. However, sample preparation and encapsulation affect the values obtained. The interaction of these cellulose ethers with water is evaluated by DSC. Water is added to the powder directly in DSC pans or preformed gels can be evaluated. Data quality depends on previous thermal history but estimates of the quantity of water bound to the polymers may be made. Water uptake by cellulose ethers may be evaluated by the use of polymeric wafers and by following loss of free water, over a series of timed curves, into wafers in contact with water. Cloud points, which assess the reduction of polymer solubility with increase of temperature, may be assessed spectrophotometrically. DSC and rheometric studies are used to follow thermogelation, a process involving hydrophobic interaction between partly hydrated polymeric chains. The advantages and disadvantages of the various methodologies are highlighted. Copyright.

Summary of Results from the Mars Phoenix Lander's Thermal Evolved Gas Analyzer

NASA Technical Reports Server (NTRS)

Sutter, B.; Ming, D. W.; Boynton, W. V.; Niles, P. B.; Hoffman, J.; Lauer, H. V.; Golden, D. C.

2009-01-01

The Mars Phoenix Scout Mission with its diverse instrument suite successfully examined several soils on the Northern plains of Mars. The Thermal and Evolved Gas Analyzer (TEGA) was employed to detect evolved volatiles and organic and inorganic materials by coupling a differential scanning calorimeter (DSC) with a magnetic-sector mass spectrometer (MS) that can detect masses in the 2 to 140 dalton range [1]. Five Martian soils were individually heated to 1000 C in the DSC ovens where evolved gases from mineral decompostion products were examined with the MS. TEGA s DSC has the capability to detect endothermic and exothermic reactions during heating that are characteristic of minerals present in the Martian soil.

7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

Code of Federal Regulations, 2012 CFR

2012-01-01

... financial ratios: (i) TIER of 1.25; (ii) Operating TIER of 1.1; (iii) DSC of 1.25; and Operating DSC of 1.1... Coverage Ratios Requirements. Section 5.5. Depreciation Rates. Section 5.6. Property Maintenance. Section 5.7. Financial Books. Section 5.8. Rights of Inspection. Section 5.9. Area Coverage. Section 5.10...

7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

Code of Federal Regulations, 2013 CFR

2013-01-01

... financial ratios: (i) TIER of 1.25; (ii) Operating TIER of 1.1; (iii) DSC of 1.25; and Operating DSC of 1.1... Coverage Ratios Requirements. Section 5.5. Depreciation Rates. Section 5.6. Property Maintenance. Section 5.7. Financial Books. Section 5.8. Rights of Inspection. Section 5.9. Area Coverage. Section 5.10...

7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

Code of Federal Regulations, 2011 CFR

2011-01-01

... financial ratios: (i) TIER of 1.25; (ii) Operating TIER of 1.1; (iii) DSC of 1.25; and Operating DSC of 1.1... Coverage Ratios Requirements. Section 5.5. Depreciation Rates. Section 5.6. Property Maintenance. Section 5.7. Financial Books. Section 5.8. Rights of Inspection. Section 5.9. Area Coverage. Section 5.10...

7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

Code of Federal Regulations, 2014 CFR

2014-01-01

... financial ratios: (i) TIER of 1.25; (ii) Operating TIER of 1.1; (iii) DSC of 1.25; and Operating DSC of 1.1... Coverage Ratios Requirements. Section 5.5. Depreciation Rates. Section 5.6. Property Maintenance. Section 5.7. Financial Books. Section 5.8. Rights of Inspection. Section 5.9. Area Coverage. Section 5.10...

Drill Sergeant Candidate Transformation

DTIC Science & Technology

2009-02-01

leadership styles of NCOs entering Drill Sergeant School (DSS). ARI also developed and administered a prototype DS Assessment Battery to assess...preferred leadership styles . DSS training increases both the degree to which the DSC feels obligated to and identifies with the Army. DSS training...4 TABLE 3. PREFERRED LEADERSHIP STYLES DEFINITIONS .............................................6 TABLE 4. DSC CHANGE IN

Thermal and dynamic mechanical properties of hydroxypropyl cellulose films

Treesearch

Timothy G. Rials; Wolfgang G. Glasser

1988-01-01

Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were used to characterize the morphology of slovent cast hydroxypropyl cellulose (HPC) films. DSC results were indicative of a semicrystalline material with a melt of 220°C and a glass transition at 19°C (T1), although an additional event was suggested by a...

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

Polan, D; Kamp, J; Lee, JY

Purpose: To perform validation and commissioning of a commercial deformable image registration (DIR) algorithm (Velocity, Varian Medical Systems) for numerous clinical sites using single and multi-modality images. Methods: In this retrospective study, the DIR algorithm was evaluated for 10 patients in each of the following body sites: head and neck (HN), prostate, liver, and gynecological (GYN). HN DIRs were evaluated from planning (p)CT to re-pCT and pCTs to daily CBCTs using dice similarity coefficients (DSC) of corresponding anatomical structures. Prostate DIRs were evaluated from pCT to CBCTs using DSC and target registration error (TRE) of implanted RF beacons within themore » prostate. Liver DIRs were evaluated from pMR to pCT using DSC and TRE of vessel bifurcations. GYN DIRs were evaluated between fractionated brachytherapy MRIs using DSC of corresponding anatomical structures. Results: Analysis to date has given average DSCs for HN pCT-to-(re)pCT DIR for the brainstem, cochleas, constrictors, spinal canal, cord, esophagus, larynx, parotids, and submandibular glands as 0.88, 0.65, 0.67, 0.91, 0.77, 0.69, 0.77, 0.87, and 0.71, respectively. Average DSCs for HN pCT-to-CBCT DIR for the constrictors, spinal canal, esophagus, larynx, parotids, and submandibular glands were 0.64, 0.90, 0.62, 0.82, 0.75, and 0.69, respectively. For prostate pCT-to-CBCT DIR the DSC for the bladder, femoral heads, prostate, and rectum were 0.71, 0.82, 0.69, and 0.61, respectively. Average TRE using implanted beacons was 3.35 mm. For liver pCT-to-pMR, the average liver DSC was 0.94 and TRE was 5.26 mm. For GYN MR-to-MR DIR the DSC for the bladder, sigmoid colon, GTV, and rectum were 0.79, 0.58, 0.67, and 0.76, respectively. Conclusion: The Velocity DIR algorithm has been evaluated over a number of anatomical sites. This work functions to document the uncertainties in the DIR in the commissioning process so that these can be accounted for in the development of downstream clinical

The Diabetes Initiative of South Carolina Celebrates Over 20 Years of Professional Diabetes Education.

PubMed

Hermayer, Kathie L

2016-04-01

Diabetes is a major public health problem in South Carolina; however, the Diabetes Initiative of South Carolina (DSC) provides a realistic mechanism to address issues on a statewide basis. The Diabetes Center of Excellence in the DSC provides oversight for developing and supervising professional education programs for health care workers of all types in South Carolina to increase their knowledge and ability to care for people with diabetes. The DSC has developed many programs for the education of a variety of health professionals about diabetes and its complications. The DSC has sponsored 21 Annual Diabetes Fall Symposia for primary health care professionals featuring education regarding many aspects of diabetes mellitus. The intent of the program is to enhance the lifelong learning process of physicians, advanced practice providers, nurses, pharmacists, dietitians, laboratorians and other health care professionals, by providing educational opportunities and to advance the quality and safety of patient care. The symposium is an annual 2-day statewide program that supplies both a comprehensive diabetes management update to all primary care professionals and an opportunity for attendees to obtain continuing education credits at a low cost. The overarching goal of the DSC is that the programs it sponsors and the development of new targeted initiatives will lead to continuous improvements in the care of people at risk and with diabetes along with a decrease in morbidity, mortality and costs of diabetes and its complications in South Carolina and elsewhere. Published by Elsevier Inc.

Quantitative blood flow measurements in gliomas using arterial spin-labeling at 3T: intermodality agreement and inter- and intraobserver reproducibility study.

PubMed

Hirai, T; Kitajima, M; Nakamura, H; Okuda, T; Sasao, A; Shigematsu, Y; Utsunomiya, D; Oda, S; Uetani, H; Morioka, M; Yamashita, Y

2011-12-01

QUASAR is a particular application of the ASL method and facilitates the user-independent quantification of brain perfusion. The purpose of this study was to assess the intermodality agreement of TBF measurements obtained with ASL and DSC MR imaging and the inter- and intraobserver reproducibility of glioma TBF measurements acquired by ASL at 3T. Two observers independently measured TBF in 24 patients with histologically proved glioma. ASL MR imaging with QUASAR and DSC MR imaging were performed on 3T scanners. The observers placed 5 regions of interest in the solid tumor on rCBF maps derived from ASL and DSC MR images and 1 region of interest in the contralateral brain and recorded the measured values. Maximum and average sTBF values were calculated. Intermodality and intra- and interobsever agreement were determined by using 95% Bland-Altman limits of agreement and ICCs. The intermodality agreement for maximum sTBF was good to excellent on DSC and ASL images; ICCs ranged from 0.718 to 0.884. The 95% limits of agreement ranged from 59.2% to 65.4% of the mean. ICCs for intra- and interobserver agreement for maximum sTBF ranged from 0.843 to 0.850 and from 0.626 to 0.665, respectively. The reproducibility of maximum sTBF measurements obtained by methods was similar. In the evaluation of sTBF in gliomas, ASL with QUASAR at 3T yielded measurements and reproducibility similar to those of DSC perfusion MR imaging.

Serious game training improves performance in combat life-saving interventions.

PubMed

Planchon, Jerome; Vacher, Anthony; Comblet, Jeremy; Rabatel, Eric; Darses, Françoise; Mignon, Alexandre; Pasquier, Pierre

2018-01-01

In modern warfare, almost 25% of combat-related deaths are considered preventable if life-saving interventions are performed. Therefore, Tactical Combat Casualty Care (TCCC) training for soldiers is a major challenge. In 2014, the French Military Medical Service supported the development of 3D-SC1 ® , a serious game designed for the French TCCC program, entitled Sauvetage au Combat de niveau 1 (SC1). Our study aimed to evaluate the impact on performance of additional training with 3D-SC1 ® . The study assessed the performance of soldiers randomly assigned to one of two groups, before (measure 1) and after (measure 2) receiving additional training. This training involved either 3D-SC1 ® (Intervention group), or a DVD (Control group). The principal measure was the individual performance (on a 16-point scale), assessed by two investigators during a hands-on simulation. First, the mean performance score was compared between the two measures for Intervention and Control groups using a two-tailed paired t-test. Second, a multivariable linear regression was used to determine the difference in the impacts of 3D-SC1 ® and DVD training, and the order of presentation of the two scenarios, on the mean change from baseline in performance scores. A total of 96 subjects were evaluated: seven could not be followed-up, while 50 were randomly allocated to the Intervention group, and 39 to the Control group. Between measure 1 and measure 2, the mean (SD) performance score increased from 9.9 (3.13) to 14.1 (1.23), and from 9.4 (2.97) to 12.5 (1.83), for the Intervention group and Control group, respectively (p<0.0001). The adjusted mean difference in performance scores between 3D-SC1 ® and DVD training was 1.1 (95% confidence interval -0.3, 2.5) (p=0.14). Overall, the study found that supplementing SC1 training with either 3D-SC1 ® or DVD improved performance, assessed by a hands-on simulation. However, our analysis did not find a statistically significant difference between the

Population genetics and phylogeography of sea turtles.

PubMed

Bowen, B W; Karl, S A

2007-12-01

The seven species of sea turtles occupy a diversity of niches, and have a history tracing back over 100 million years, yet all share basic life-history features, including exceptional navigation skills and periodic migrations from feeding to breeding habitats. Here, we review the biogeographic, behavioural, and ecological factors that shape the distribution of genetic diversity in sea turtles. Natal homing, wherein turtles return to their region of origin for mating and nesting, has been demonstrated with mtDNA sequences. These maternally inherited markers show strong population structure among nesting colonies while nuclear loci reveal a contrasting pattern of male-mediated gene flow, a phenomenon termed 'complex population structure'. Mixed-stock analyses indicate that multiple nesting colonies can contribute to feeding aggregates, such that exploitation of turtles in these habitats can reduce breeding populations across the region. The mtDNA data also demonstrate migrations across entire ocean basins, some of the longest movements of marine vertebrates. Multiple paternity occurs at reported rates of 0-100%, and can vary by as much as 9-100% within species. Hybridization in almost every combination among members of the Cheloniidae has been documented but the frequency and ultimate ramifications of hybridization are not clear. The global phylogeography of sea turtles reveals a gradient based on habitat preference and thermal regime. The cold-tolerant leatherback turtle (Dermochelys coriacea) shows no evolutionary partitions between Indo-Pacific and Atlantic populations, while the tropical green (Chelonia mydas), hawksbill (Eretmochelys imbricata), and ridleys (Lepidochelys olivacea vs. L. kempi) have ancient separations between oceans. Ridleys and loggerhead (Caretta caretta) also show more recent colonization between ocean basins, probably mediated by warm-water gyres that occasionally traverse the frigid upwelling zone in southern Africa. These rare events may

7 CFR 1744.30 - Automatic lien accommodations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... supplemental mortgage is a valid and binding instrument enforceable in accordance with its terms, and recorded...: (1) The borrower has achieved a TIER of not less than 1.5 and a DSC of not less than 1.25 for each of... not less than 2.5 and a DSC of not less than 1.5 for each of the borrower's two fiscal years...

7 CFR 1744.30 - Automatic lien accommodations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... supplemental mortgage is a valid and binding instrument enforceable in accordance with its terms, and recorded...: (1) The borrower has achieved a TIER of not less than 1.5 and a DSC of not less than 1.25 for each of... not less than 2.5 and a DSC of not less than 1.5 for each of the borrower's two fiscal years...

7 CFR 1710.114 - TIER, DSC, OTIER and ODSC requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) General. Requirements for coverage ratios are set forth in the borrower's mortgage, loan contract, or..., shall reduce the coverage ratio requirements of a borrower that has contractually agreed with RUS to a higher requirement. (b) Coverage ratios. (1) Distribution borrowers. The minimum coverage ratios required...

Dynamic Synchronous Capture Algorithm for an Electromagnetic Flowmeter.

PubMed

Fanjiang, Yong-Yi; Lu, Shih-Wei

2017-04-10

This paper proposes a dynamic synchronous capture (DSC) algorithm to calculate the flow rate for an electromagnetic flowmeter. The characteristics of the DSC algorithm can accurately calculate the flow rate signal and efficiently convert an analog signal to upgrade the execution performance of a microcontroller unit (MCU). Furthermore, it can reduce interference from abnormal noise. It is extremely steady and independent of fluctuations in the flow measurement. Moreover, it can calculate the current flow rate signal immediately (m/s). The DSC algorithm can be applied to the current general MCU firmware platform without using DSP (Digital Signal Processing) or a high-speed and high-end MCU platform, and signal amplification by hardware reduces the demand for ADC accuracy, which reduces the cost.

Neural network-based adaptive dynamic surface control for permanent magnet synchronous motors.

PubMed

Yu, Jinpeng; Shi, Peng; Dong, Wenjie; Chen, Bing; Lin, Chong

2015-03-01

This brief considers the problem of neural networks (NNs)-based adaptive dynamic surface control (DSC) for permanent magnet synchronous motors (PMSMs) with parameter uncertainties and load torque disturbance. First, NNs are used to approximate the unknown and nonlinear functions of PMSM drive system and a novel adaptive DSC is constructed to avoid the explosion of complexity in the backstepping design. Next, under the proposed adaptive neural DSC, the number of adaptive parameters required is reduced to only one, and the designed neural controllers structure is much simpler than some existing results in literature, which can guarantee that the tracking error converges to a small neighborhood of the origin. Then, simulations are given to illustrate the effectiveness and potential of the new design technique.

Dynamic Synchronous Capture Algorithm for an Electromagnetic Flowmeter

PubMed Central

Fanjiang, Yong-Yi; Lu, Shih-Wei

2017-01-01

This paper proposes a dynamic synchronous capture (DSC) algorithm to calculate the flow rate for an electromagnetic flowmeter. The characteristics of the DSC algorithm can accurately calculate the flow rate signal and efficiently convert an analog signal to upgrade the execution performance of a microcontroller unit (MCU). Furthermore, it can reduce interference from abnormal noise. It is extremely steady and independent of fluctuations in the flow measurement. Moreover, it can calculate the current flow rate signal immediately (m/s). The DSC algorithm can be applied to the current general MCU firmware platform without using DSP (Digital Signal Processing) or a high-speed and high-end MCU platform, and signal amplification by hardware reduces the demand for ADC accuracy, which reduces the cost. PMID:28394306

Disproportionation of a crystalline citrate salt of a developmental pharmaceutical compound: characterization of the kinetics using pH monitoring and online Raman spectroscopy plus quantitation of the crystalline free base form in binary physical mixtures using FT-Raman, XRPD and DSC.

PubMed

Skrdla, Peter J; Zhang, Dan

2014-03-01

The crystalline citrate salt (CS) of a developmental pharmaceutical compound, MK-Q, was investigated in this work from two different, but related, perspectives. In the first part of the paper, the apparent disproportionation kinetics were surveyed using two different slurry systems, one containing water and the other a pH 6.9 phosphate buffer, using time-dependent measurements of the solution pH or by acquiring online Raman spectra of the solids. While the CS is generally stable when stored as a solid under ambient conditions of temperature and humidity, its low pHmax (<3) facilitates rapid disproportionation in aqueous solution, particularly at higher pH values. The rate of disappearance of the CS was found to obey first-order (Noyes-Whitney/dissolution rate-limited) kinetics, however, the formation of the crystalline product form in the slurry system was observed to exhibit kinetics consistent with a heterogeneous nucleation-and-growth mechanism. In the second part of this paper, more sensitive offline measurements made using XRPD, DSC and FT-Raman spectroscopy were applied to the characterization of binary physical mixtures of the CS and free base (FB) crystalline forms of MK-Q to obtain a calibration curve for each technique. It was found that all calibration plots exhibited good linearity of response, with the limit of detection (LOD) for each technique estimated to be ≤7 wt% FB. While additional calibration curves would need to be constructed to allow for accurate quantitation in various slurry systems, the general feasibility of these techniques is demonstrated for detecting low levels of CS disproportionation. Copyright © 2013 Elsevier B.V. All rights reserved.

Black Hawk Down: Film Zwischen Reflektion und Konstruktion Gesellschaftlicher Wirklichkeit

NASA Astrophysics Data System (ADS)

Pötzsch, Holger

2009-05-01

BLACK HAWK DOWN: FILM BETWEEN THE REFLECTION AND CONSTRUCTION OF SOCIAL REALITY - In this article, Ridley Scott's film Black Hawk Down (USA 2001) is read in the context of contemporary theories concerning cultural memory (Jan and Aleida Assmann) and media culture (Douglas Kellner). It is argued that film (and representation in general) does not merely reflect a preceding reality; it also actively serves to construct it. It is shown how Scott's film privileges one particular perspective on an actual event and how this point of view is objectified and installed in the memory of Western media culture. What potential implications does an increased blurring of fact and fiction in the representation of war have? What are the consequences for political and pedagogical practice? What role can cultural studies play in these processes?

Detection of cocrystal formation based on binary phase diagrams using thermal analysis.

PubMed

Yamashita, Hiroyuki; Hirakura, Yutaka; Yuda, Masamichi; Teramura, Toshio; Terada, Katsuhide

2013-01-01

Although a number of studies have reported that cocrystals can form by heating a physical mixture of two components, details surrounding heat-induced cocrystal formation remain unclear. Here, we attempted to clarify the thermal behavior of a physical mixture and cocrystal formation in reference to a binary phase diagram. Physical mixtures prepared using an agate mortar were heated at rates of 2, 5, 10, and 30 °C/min using differential scanning calorimetry (DSC). Some mixtures were further analyzed using X-ray DSC and polarization microscopy. When a physical mixture consisting of two components which was capable of cocrystal formation was heated using DSC, an exothermic peak associated with cocrystal formation was detected immediately after an endothermic peak. In some combinations, several endothermic peaks were detected and associated with metastable eutectic melting, eutectic melting, and cocrystal melting. In contrast, when a physical mixture of two components which is incapable of cocrystal formation was heated using DSC, only a single endothermic peak associated with eutectic melting was detected. These experimental observations demonstrated how the thermal events were attributed to phase transitions occurring in a binary mixture and clarified the relationship between exothermic peaks and cocrystal formation.

Probing the heat sources during thermal runaway process by thermal analysis of different battery chemistries

NASA Astrophysics Data System (ADS)

Zheng, Siqi; Wang, Li; Feng, Xuning; He, Xiangming

2018-02-01

Safety issue is very important for the lithium ion battery used in electric vehicle or other applications. This paper probes the heat sources in the thermal runaway processes of lithium ion batteries composed of different chemistries using accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC). The adiabatic thermal runaway features for the 4 types of commercial lithium ion batteries are tested using ARC, whereas the reaction characteristics of the component materials, including the cathode, the anode and the separator, inside the 4 types of batteries are measured using DSC. The peaks and valleys of the critical component reactions measured by DSC can match the fluctuations in the temperature rise rate measured by ARC, therefore the relevance between the DSC curves and the ARC curves is utilized to probe the heat source in the thermal runaway process and reveal the thermal runaway mechanisms. The results and analysis indicate that internal short circuit is not the only way to thermal runaway, but can lead to extra electrical heat, which is comparable with the heat released by chemical reactions. The analytical approach of the thermal runaway mechanisms in this paper can guide the safety design of commercial lithium ion batteries.

Use of differential scanning calorimetry to detect canola oil (Brassica napus L.) adulterated with lard stearin.

PubMed

Marikkar, Jalaldeen Mohammed Nazrim; Rana, Sohel

2014-01-01

A study was conducted to detect and quantify lard stearin (LS) content in canola oil (CaO) using differential scanning calorimetry (DSC). Authentic samples of CaO were obtained from a reliable supplier and the adulterant LS were obtained through a fractional crystallization procedure as reported previously. Pure CaO samples spiked with LS in levels ranging from 5 to 15% (w/w) were analyzed using DSC to obtain their cooling and heating profiles. The results showed that samples contaminated with LS at 5% (w/w) level can be detected using characteristic contaminant peaks appearing in the higher temperature regions (0 to 70°C) of the cooling and heating curves. Pearson correlation analysis of LS content against individual DSC parameters of the adulterant peak namely peak temperature, peak area, peak onset temperature indicated that there were strong correlations between these with the LS content of the CaO admixtures. When these three parameters were engaged as variables in the execution of the stepwise regression procedure, predictive models for determination of LS content in CaO were obtained. The predictive models obtained with single DSC parameter had relatively lower coefficient of determination (R(2) value) and higher standard error than the models obtained using two DSC parameters in combination. This study concluded that the predictive models obtained with peak area and peak onset temperature of the adulteration peak would be more accurate for prediction of LS content in CaO based on the highest coefficient of determination (R(2) value) and smallest standard error.

IDH mutant and 1p/19q co-deleted oligodendrogliomas: tumor grade stratification using diffusion-, susceptibility-, and perfusion-weighted MRI.

PubMed

Lin, Yu; Xing, Zhen; She, Dejun; Yang, Xiefeng; Zheng, Yingyan; Xiao, Zebin; Wang, Xingfu; Cao, Dairong

2017-06-01

Currently, isocitrate dehydrogenase (IDH) mutation and 1p/19q co-deletion are proven diagnostic biomarkers for both grade II and III oligodendrogliomas (ODs). Non-invasive diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) are widely used to provide physiological information (cellularity, hemorrhage, calcifications, and angiogenesis) of neoplastic histology and tumor grade. However, it is unclear whether DWI, SWI, and DSC-PWI are able to stratify grades of IDH-mutant and 1p/19q co-deleted ODs. We retrospectively reviewed the conventional MRI (cMRI), DWI, SWI, and DSC-PWI obtained on 33 patients with IDH-mutated and 1p/19q co-deleted ODs. Features of cMRI, normalized ADC (nADC), intratumoral susceptibility signals (ITSSs), normalized maxim CBV (nCBV), and normalized maximum CBF (nCBF) were compared between low-grade ODs (LGOs) and high-grade ODs (HGOs). Receiver operating characteristic curve and logistic regression were applied to determine diagnostic performances. HGOs tended to present with prominent edema and enhancement. nADC, ITSSs, nCBV, and nCBF were significantly different between groups (all P < 0.05). The combination of SWI and DSC-PWI for grading resulted in sensitivity and specificity of 100.00 and 93.33%, respectively. IDH-mutant and 1p/19q co-deleted ODs can be stratified by grades using cMRI and advanced magnetic resonance imaging techniques including DWI, SWI, and DSC-PWI. Combined ITSSs with nCBV appear to be a promising option for grading molecularly defined ODs in clinical practice.

Cardiorespiratory fitness does not alter plasma pentraxin 3 and cortisol reactivity to acute psychological stress and exercise.

PubMed

Huang, Chun-Jung; Webb, Heather E; Beasley, Kathleen N; McAlpine, David A; Tangsilsat, Supatchara E; Acevedo, Edmund O

2014-03-01

Pentraxin 3 (PTX3) has been recently identified as a biomarker of vascular inflammation in predicting cardiovascular events. The purpose of this study was to examine the effect of cardiorespiratory fitness on plasma PTX3 and cortisol responses to stress, utilizing a dual-stress model. Fourteen male subjects were classified into high-fit (HF) and low-fit (LF) groups and completed 2 counterbalanced experimental conditions. The exercise-alone condition (EAC) consisted of cycling at 60% maximal oxygen uptake for 37 min, while the dual-stress condition (DSC) included 20 min of a mental stress while cycling for 37 min. Plasma PTX3 revealed significant increases over time with a significant elevation at 37 min in both HF and LF groups in response to EAC and DSC. No difference in plasma PTX3 levels was observed between EAC and DSC. In addition, plasma cortisol revealed a significant condition by time interaction with greater levels during DSC at 37 min, whereas cardiorespiratory fitness level did not reveal different plasma cortisol responses in either the EAC or DSC. Aerobic exercise induces plasma PTX3 release, while additional acute mental stress, in a dual-stress condition, does not exacerbate or further modulate the PTX3 response. Furthermore, cardiorespiratory fitness may not affect the stress reactivity of plasma PTX3 to physical and combined physical and psychological stressors. Finally, the exacerbated cortisol responses to combined stress may provide the potential link to biological pathways that explain changes in physiological homeostasis that may be associated with an increase in the risk of cardiovascular disease.

Impact on carbon footprint: a life cycle assessment of disposable versus reusable sharps containers in a large US hospital.

PubMed

Grimmond, Terry; Reiner, Sandra

2012-06-01

Hospitals are striving to reduce their greenhouse gas (GHG) emissions. Targeting supply chain points and replacing disposable with reusable items are among recommendations to achieve this. Annually, US hospitals use 35 million disposable (DSC) or reusable sharps containers (RSC) generating GHG in their manufacture, use, and disposal. Using a life cycle assessment we assessed the global warming potential (GWP) of both systems at a large US hospital which replaced DSC with RSC. GHG emissions (CO(2), CH(4), N(2)O) were calculated in metric tons of CO(2) equivalents (MTCO(2)eq). Primary energy input data was used wherever possible and region-specific conversions used to calculate the GWP of each activity. Unit process GHGs were collated into manufacture, transport, washing, and treatment and disposal. The DSC were not recycled nor had recycled content. Chemotherapy DSC were used in both systems. Emission totals were workload-normalized per 100 occupied beds-yr and rate ratio analyzed using Fisher's test with P ≤0.05 and 95% confidence level. With RSC, the hospital reduced its annual GWP by 127 MTCO(2)eq (-83.5%) and diverted 30.9 tons of plastic and 5.0 tons of cardboard from landfill. Using RSC reduced the number of containers manufactured from 34,396 DSC annually to 1844 RSC in year one only. The study indicates sharps containment GWP in US hospitals totals 100,000 MTCO(2)eq and if RSC were used nationally the figure could fall by 64,000 MTCO(2)eq which, whilst only a fraction of total hospital GWP, is a positive, sustainable step.

Effects of particle reinforcement and ECAP on the precipitation kinetics of an Al-Cu alloy

NASA Astrophysics Data System (ADS)

Härtel, M.; Wagner, S.; Frint, P.; F-X Wagner, M.

2014-08-01

The precipitation kinetics of Al-Cu alloys have recently been revisited in various studies, considering either the effect of severe plastic deformation (e.g., by equal-channel angular pressing - ECAP), or the effect of particle reinforcements. However, it is not clear how these effects interact when ECAP is performed on particle-reinforced alloys. In this study, we analyze how a combination of particle reinforcement and ECAP affects precipitation kinetics. After solution annealing, an AA2017 alloy (initial state: base material without particle reinforcement); AA2017 + 10 vol.-% Al2O3; and AA2017 + 10 vol.-% SiC were deformed in one pass in a 120° ECAP tool at a temperature of 140°C. Systematic differential scanning calorimetry (DSC) measurements of each condition were carried out. TEM specimens were prepared out of samples from additional DSC measurements, where the samples were immediately quenched in liquid nitrogen after reaching carefully selected temperatures. TEM analysis was performed to characterize the morphology of the different types of precipitates, and to directly relate microstructural information to the endo- and exothermic peaks in our DSC data. Our results show that both ECAP and particle reinforcement are associated with a shift of exothermic precipitation peaks towards lower temperatures. This effect is even more pronounced when ECAP and particle reinforcement are combined. The DSC data agrees well with our TEM observations of nucleation and morphology of different precipitates, indicating that DSC measurements are an appropriate tool for the analysis of how severe plastic deformation and particle reinforcement affect precipitation kinetics in Al-Cu alloys.

47 CFR 80.1077 - Frequencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... System: Alerting: 406.0-406.1 EPIRBs 406.0-406.1 MHz (Earth-to-space).1544-1545 MHz (space-to-Earth). INMARSAT-E EPIRBs 12 1626.5-1645.5 MHz (Earth-to-space). INMARSAT Ship Earth Stations capable of voice and/or direct printing 1626.5-1645.5 MHz (Earth-to-space). VHF DSC Ch. 70 156.525 MHz. 1 MF/HF DSC 2 2187...

Characterization of cure kinetics and physical properties of a high performance, glass fiber-reinforced epoxy prepreg and a novel fluorine-modified, amine-cured commercial epoxy

NASA Astrophysics Data System (ADS)

Bilyeu, Bryan

Kinetic equation parameters for the curing reaction of a commercial glass fiber reinforced high performance epoxy prepreg composed of the tetrafunctional epoxy tetraglycidyl 4,4-diaminodiphenyl methane (TGDDM), the tetrafunctional amine curing agent 4,4'-diaminodiphenylsulfone (DDS) and an ionic initiator/accelerator, are determined by various thermal analysis techniques and the results compared. The reaction is monitored by heat generated determined by differential scanning calorimetry (DSC) and by high speed DSC when the reaction rate is high. The changes in physical properties indicating increasing conversion are followed by shifts in glass transition temperature determined by DSC, temperature-modulated DSC (TMDSC), step scan DSC and high speed DSC, thermomechanical (TMA) and dynamic mechanical (DMA) analysis and thermally stimulated depolarization (TSD). Changes in viscosity, also indicative of degree of conversion, are monitored by DMA. Thermal stability as a function of degree of cure is monitored by thermogravimetric analysis (TGA). The parameters of the general kinetic equations, including activation energy and rate constant, are explained and used to compare results of various techniques. The utilities of the kinetic descriptions are demonstrated in the construction of a useful time-temperature-transformation (TTT) diagram and a continuous heating transformation (CHT) diagram for rapid determination of processing parameters in the processing of prepregs. Shrinkage due to both resin consolidation and fiber rearrangement is measured as the linear expansion of the piston on a quartz dilatometry cell using TMA. The shrinkage of prepregs was determined to depend on the curing temperature, pressure applied and the fiber orientation. Chemical modification of an epoxy was done by mixing a fluorinated aromatic amine (aniline) with a standard aliphatic amine as a curing agent for a commercial Diglycidylether of Bisphenol-A (DGEBA) epoxy. The resulting cured network

Quantum-chemical insight into structure-reactivity relationship in 4,5,6,7-tetrahalogeno-1H-benzimidazoles: a combined X-ray, DSC, DFT/QTAIM, Hirshfeld surface-based, and molecular docking approach.

PubMed

Latosińska, Jolanta Natalia; Latosińska, Magdalena; Maurin, Jan Krzysztof; Orzeszko, Andrzej; Kazimierczuk, Zygmunt

2014-03-20

The weak interaction patterns in 4,5,6,7-tetrahalogeno-1H-benzimidazoles, protein kinase CK2 inhibitors, in solid state are studied by the X-ray method and quantum chemistry calculations. The crystal structures of 4,5,6,7-tetrachloro- and 4,5,6,7-tetrabromo-1H-benzimidazole are determined by X-ray diffraction and refined to a final R-factor of 3.07 and 3.03%, respectively, at room temperature. The compound 4,5,6,7-tetrabromo-1H-benzimidazole, which crystallizes in the I41/a space group, is found to be isostructural with previously studied 4,5,6,7-tetraiodo-1H-benzimidazole in contrast to 4,5,6,7-tetrachloro-1H-benzimidazole, which crystallizes as triclinic P1̅ with 4 molecules in elementary unit. For 4,5,6,7-tetrachloro-1H-benzimidazole, differential scanning calorimetry (DSC) revealed a second order glassy phase transition at Tg = 95°/106° (heating/cooling), an indication of frozen disorder. The lack of 3D isostructurality found in all 4,5,6,7-tetrahalogeno-1H-benzimidazoles is elucidated on the basis of the intra- and intermolecular interactions (hydrogen bonding, van der Waals contacts, and C-H···π interactions). The topological Bader's Quantum Theory of Atoms in Molecules (QTAIM) and Spackman's Hirshfeld surface-based approaches reveal equilibration of electrostatic matching and dispersion van der Waals interactions between molecules consistent with the crystal site-symmetry. The weakening of van der Waals forces accompanied by increasing strength of the hydrogen bond (N-H···N) result in a decrease in the crystal site-symmetry and a change in molecular packing in the crystalline state. Crystal packing motifs were investigated with the aid of Hirshfeld surface fingerprint plots. The ordering 4,5,6,7-tetraiodo > 4,5,6,7-tetrabromo > 4,5,6,7-tetrachloro > 4,5,6,7-tetrafluoro reflects not only a decrease in crystal symmetry but also increase in chemical reactivity (electronic activation), which could explain some changes in biological activity of

Designated Stroke Center Status and Hospital Characteristics as Predictors of In-Hospital Mortality among Hemorrhagic Stroke Patients in New York, 2008-2012.

PubMed

Gatollari, Hajere J; Colello, Anna; Eisenberg, Bonnie; Brissette, Ian; Luna, Jorge; Elkind, Mitchell S V; Willey, Joshua Z

2017-01-01

Although designated stroke centers (DSCs) improve the quality of care and clinical outcomes for ischemic stroke patients, less is known about the benefits of DSCs for patients with intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). Compared to non-DSCs, hospitals with the DSC status have lower in-hospital mortality rates for hemorrhagic stroke patients. We believed these effects would sustain over a period of time after adjusting for hospital-level characteristics, including hospital size, urban location, and teaching status. We evaluated ICH (International Classification of Diseases, Ninth Revision; ICD-9: 431) and SAH (ICD-9: 430) hospitalizations documented in the 2008-2012 New York State Department of Health Statewide Planning and Research Cooperative System inpatient sample database. Generalized estimating equation logistic regression was used to evaluate the association between DSC status and in-hospital mortality. We calculated ORs and 95% CIs adjusted for clustering of patients within facilities, other hospital characteristics, and individual level characteristics. Planned secondary analyses explored other hospital characteristics associated with in-hospital mortality. In 6,352 ICH and 3,369 SAH patients in the study sample, in-hospital mortality was higher among those with ICH compared to SAH (23.7 vs. 18.5%). Unadjusted analyses revealed that DSC status was related with reduced mortality for both ICH (OR 0.7, 95% CI 0.5-0.8) and SAH patients (OR 0.4, 95% CI 0.3-0.7). DSC remained a significant predictor of lower in-hospital mortality for SAH patients (OR 0.6, 95% CI 0.3-0.9) but not for ICH patients (OR 0.8, 95% CI 0.6-1.0) after adjusting for patient demographic characteristics, comorbidities, hospital size, teaching status and location. Admission to a DSC was independently associated with reduced in-hospital mortality for SAH patients but not for those with ICH. Other patient and hospital characteristics may explain the benefits of DSC

Dye-sensitized solar cells and complexes between pyridines and iodines. A NMR, IR and DFT study.

PubMed

Hansen, Poul Erik; Nguyen, Phuong Tuyet; Krake, Jacob; Spanget-Larsen, Jens; Lund, Torben

2012-12-01

Interactions between triiodide (I(3)(-)) and 4-tert-butylpyridine (4TBP) as postulated in dye-sensitized solar cells (DSC) are investigated by means of (13)C NMR and IR spectroscopy supported by DFT calculations. The charge transfer (CT) complex 4TBP·I(2) and potential salts such as (4TBP)(2)I(+), I(3)(-) were synthesized and characterized by IR and (13)C NMR spectroscopy. However, mixing (butyl)(4)N(+), I(3)(-) and 4TBP at concentrations comparable to those of the DSC solar cell did not lead to any reaction. Neither CT complexes nor cationic species like (4TBP)(2)I(+) were observed, judging from the (13)C NMR spectroscopic evidence. This questions the previously proposed formation of (4TBP)(2)I(+) in DSC cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Differential Scanning Calorimetry and Evolved Gas Analysis at Mars Ambient Conditions Using the Thermal Evolved Gas Analyzer (TEGA)

NASA Technical Reports Server (NTRS)

Musselwhite, D. S.; Boynton, W. V.; Ming, Douglas W.; Quadlander, G.; Kerry, K. E.; Bode, R. C.; Bailey, S. H.; Ward, M. G.; Pathare, A. V.; Lorenz, R. D.

2000-01-01

Differential Scanning Calorimetry (DSC) combined with evolved gas analysis (EGA) is a well developed technique for the analysis of a wide variety of sample types with broad application in material and soil sciences. However, the use of the technique for samples under conditions of pressure and temperature as found on other planets is one of current C development and cutting edge research. The Thermal Evolved Gas Analyzer (MGA), which was designed, built and tested at the University of Arizona's Lunar and Planetary Lab (LPL), utilizes DSC/EGA. TEGA, which was sent to Mars on the ill-fated Mars Polar Lander, was to be the first application of DSC/EGA on the surface of Mars as well as the first direct measurement of the volatile-bearing mineralogy in martian soil.

One-step simultaneous differential scanning calorimetry-FTIR microspectroscopy to quickly detect continuous pathways in the solid-state glucose/asparagine Maillard reaction.

PubMed

Hwang, Deng-Fwu; Hsieh, Tzu-Feng; Lin, Shan-Yang

2013-01-01

The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.

Social Media Impact of the Food and Drug Administration's Drug Safety Communication Messaging About Zolpidem: Mixed-Methods Analysis.

PubMed

Sinha, Michael S; Freifeld, Clark C; Brownstein, John S; Donneyong, Macarius M; Rausch, Paula; Lappin, Brian M; Zhou, Esther H; Dal Pan, Gerald J; Pawar, Ajinkya M; Hwang, Thomas J; Avorn, Jerry; Kesselheim, Aaron S

2018-01-05

The Food and Drug Administration (FDA) issues drug safety communications (DSCs) to health care professionals, patients, and the public when safety issues emerge related to FDA-approved drug products. These safety messages are disseminated through social media to ensure broad uptake. The objective of this study was to assess the social media dissemination of 2 DSCs released in 2013 for the sleep aid zolpidem. We used the MedWatcher Social program and the DataSift historic query tool to aggregate Twitter and Facebook posts from October 1, 2012 through August 31, 2013, a period beginning approximately 3 months before the first DSC and ending 3 months after the second. Posts were categorized as (1) junk, (2) mention, and (3) adverse event (AE) based on a score between -0.2 (completely unrelated) to 1 (perfectly related). We also looked at Google Trends data and Wikipedia edits for the same time period. Google Trends search volume is scaled on a range of 0 to 100 and includes "Related queries" during the relevant time periods. An interrupted time series (ITS) analysis assessed the impact of DSCs on the counts of posts with specific mention of zolpidem-containing products. Chow tests for known structural breaks were conducted on data from Twitter, Facebook, and Google Trends. Finally, Wikipedia edits were pulled from the website's editorial history, which lists all revisions to a given page and the editor's identity. In total, 174,286 Twitter posts and 59,641 Facebook posts met entry criteria. Of those, 16.63% (28,989/174,286) of Twitter posts and 25.91% (15,453/59,641) of Facebook posts were labeled as junk and excluded. AEs and mentions represented 9.21% (16,051/174,286) and 74.16% (129,246/174,286) of Twitter posts and 5.11% (3,050/59,641) and 68.98% (41,138/59,641) of Facebook posts, respectively. Total daily counts of posts about zolpidem-containing products increased on Twitter and Facebook on the day of the first DSC; Google searches increased on the week of the

Synthesis of Hydrophobic, Crosslinkable Resins.

DTIC Science & Technology

1985-12-01

product by methanol precipitation the majority of the first oligomer was L-"- lost. 4.14 DIFFERENTIAL SCANNING CALORIMETRY. The DSC trace of a typical...polymer from the DSC traces obtained to dcte. Preliminary studies using an automated torsional pendulum indicate that the Tg of the crosslinked polymer is...enabling water to be used in the purification steps. The diethyl phosphonates are readily prepared by heating triethyl phosphite with the chloromethyl

Delayed Sternal Closure in Infant Heart Surgery-The Importance of Where and When: An Analysis of the STS Congenital Heart Surgery Database.

PubMed

Nelson-McMillan, Kristen; Hornik, Christoph P; He, Xia; Vricella, Luca A; Jacobs, Jeffrey P; Hill, Kevin D; Pasquali, Sara K; Alejo, Diane E; Cameron, Duke E; Jacobs, Marshall L

2016-11-01

Delayed sternal closure (DSC) is commonly used to optimize hemodynamic stability after neonatal and infant heart surgery. We hypothesized that duration of sternum left open (SLO) was associated with rate of infection complications, and that location of sternal closure may mitigate infection risk. Infants (age ≤365 days) undergoing index operations with cardiopulmonary bypass and DSC at STS Congenital Heart Surgery Database centers (from 2007 to 2013) with adequate data quality were included. Primary outcome was occurrence of infection complication, defined as one or more of the following: endocarditis, pneumonia, wound infection, wound dehiscence, sepsis, or mediastinitis. Multivariable regression models were fit to assess association of infection complication with: duration of SLO (days), location of DSC procedure (operating room versus elsewhere), and patient and procedural factors. Of 6,127 index operations with SLO at 100 centers, median age and weight were 8 days (IQR, 5-24) and 3.3 kg (IQR, 2.9-3.8); 66% of operations were STAT morbidity category 4 or 5. At least one infection complication occurred in 18.7%, compared with 6.6% among potentially eligible neonates and infants without SLO. Duration of SLO (median, 3 days; IQR, 2-5) was associated with an increased rate of infection complications (p < 0.001). Location of DSC procedure was operating room (16%), intensive care unit (67%), or other (17%). Location of DSC was not associated with rate of infection complications (p = 0.45). Rate of occurrence of infectious complications is high among infants with sternum left open following cardiac surgery. Longer duration of SLO is associated with increased infection complications. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Raman scattering boson peak and differential scanning calorimetry studies of the glass transition in tellurium-zinc oxide glasses.

PubMed

Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C; Capoen, B; Bouazaoui, M; Turrell, S; Khatir, S

2010-05-19

Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO(2))(1 - x)(ZnO)(x) (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T(g) has been determined for each glass, showing a monotonous decrease of T(g) with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T(d) very close to the respective T(g) values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T(g) in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T(g) and confirms the correlation between the BP and the MRO of glasses.

Deconvolution of complex differential scanning calorimetry profiles for protein transitions under kinetic control.

PubMed

Toledo-Núñez, Citlali; Vera-Robles, L Iraís; Arroyo-Maya, Izlia J; Hernández-Arana, Andrés

2016-09-15

A frequent outcome in differential scanning calorimetry (DSC) experiments carried out with large proteins is the irreversibility of the observed endothermic effects. In these cases, DSC profiles are analyzed according to methods developed for temperature-induced denaturation transitions occurring under kinetic control. In the one-step irreversible model (native → denatured) the characteristics of the observed single-peaked endotherm depend on the denaturation enthalpy and the temperature dependence of the reaction rate constant, k. Several procedures have been devised to obtain the parameters that determine the variation of k with temperature. Here, we have elaborated on one of these procedures in order to analyze more complex DSC profiles. Synthetic data for a heat capacity curve were generated according to a model with two sequential reactions; the temperature dependence of each of the two rate constants involved was determined, according to the Eyring's equation, by two fixed parameters. It was then shown that our deconvolution procedure, by making use of heat capacity data alone, permits to extract the parameter values that were initially used. Finally, experimental DSC traces showing two and three maxima were analyzed and reproduced with relative success according to two- and four-step sequential models. Copyright © 2016 Elsevier Inc. All rights reserved.

Time-series modeling and prediction of global monthly absolute temperature for environmental decision making

NASA Astrophysics Data System (ADS)

Ye, Liming; Yang, Guixia; Van Ranst, Eric; Tang, Huajun

2013-03-01

A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined (DSC) approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average (SARIMA) models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term (˜10-year) environmental planning and decision making.

Toward a Psychology of Social Change: A Typology of Social Change

PubMed Central

de la Sablonnière, Roxane

2017-01-01

Millions of people worldwide are affected by dramatic social change (DSC). While sociological theory aims to understand its precipitants, the psychological consequences remain poorly understood. A large-scale literature review pointed to the desperate need for a typology of social change that might guide theory and research toward a better understanding of the psychology of social change. Over 5,000 abstracts from peer-reviewed articles were assessed from sociological and psychological publications. Based on stringent inclusion criteria, a final 325 articles were used to construct a novel, multi-level typology designed to conceptualize and categorize social change in terms of its psychological threat to psychological well-being. The typology of social change includes four social contexts: Stability, Inertia, Incremental Social Change and, finally, DSC. Four characteristics of DSC were further identified: the pace of social change, rupture to the social structure, rupture to the normative structure, and the level of threat to one's cultural identity. A theoretical model that links the characteristics of social change together and with the social contexts is also suggested. The typology of social change as well as our theoretical proposition may serve as a foundation for future investigations and increase our understanding of the psychologically adaptive mechanisms used in the wake of DSC. PMID:28400739

Heat resistance of viable but non-culturable Escherichia coli cells determined by differential scanning calorimetry.

PubMed

Castro-Rosas, Javier; Gómez-Aldapa, Carlos Alberto; Villagómez Ibarra, José Roberto; Santos-López, Eva María; Rangel-Vargas, Esmeralda

2017-10-16

Several reports have suggested that the viable but non-culturable (VBNC) state is a resistant form of bacterial cells that allows them to remain in a dormant form in the environment. Nevertheless, studies on the resistance of VBNC bacterial cells to ecological factors are limited, mainly because techniques that allow this type of evaluation are lacking. Differential scanning calorimetry (DSC) has been used to study the thermal resistance of culturable bacteria but has never been used to study VBNC cells. In this work, the heat resistance of Escherichia coli cells in the VBNC state was studied using the DSC technique. The VBNC state was induced in E. coli ATCC 25922 by suspending bacterial cells in artificial sea water, followed by storage at 3 ± 2°C for 110 days. Periodically, the behaviour of E. coli cells was monitored by plate counts, direct viable counts and DSC. The entire bacterial population entered the VBNC state after 110 days of storage. The results obtained with DSC suggest that the VBNC state does not confer thermal resistance to E. coli cells in the temperature range analysed here. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Toward a Psychology of Social Change: A Typology of Social Change.

PubMed

de la Sablonnière, Roxane

2017-01-01

Millions of people worldwide are affected by dramatic social change (DSC). While sociological theory aims to understand its precipitants, the psychological consequences remain poorly understood. A large-scale literature review pointed to the desperate need for a typology of social change that might guide theory and research toward a better understanding of the psychology of social change. Over 5,000 abstracts from peer-reviewed articles were assessed from sociological and psychological publications. Based on stringent inclusion criteria, a final 325 articles were used to construct a novel, multi-level typology designed to conceptualize and categorize social change in terms of its psychological threat to psychological well-being. The typology of social change includes four social contexts: Stability, Inertia, Incremental Social Change and, finally, DSC. Four characteristics of DSC were further identified: the pace of social change, rupture to the social structure, rupture to the normative structure, and the level of threat to one's cultural identity. A theoretical model that links the characteristics of social change together and with the social contexts is also suggested. The typology of social change as well as our theoretical proposition may serve as a foundation for future investigations and increase our understanding of the psychologically adaptive mechanisms used in the wake of DSC.

Differential Scanning Calorimetry and Evolved Gas Analysis at Mars Ambient Conditions Using the Thermal Evolved Gas Analyser (TEGA)

NASA Technical Reports Server (NTRS)

Musselwhite, D. S.; Boynton, W. V.; Ming, D. W.; Quadlander, G.; Kerry, K. E.; Bode, R. C.; Bailey, S. H.; Ward, M. G.; Pathare, A. V.; Lorenz, R. D.

2000-01-01

Differential Scanning Calorimetry (DSC) combined with evolved gas analysis (EGA) is a well developed technique for the analysis of a wide variety of sample types with broad application in material and soil sciences. However, the use of the technique for samples under conditions of pressure and temperature as found on other planets is one of current development and cutting edge research. The Thermal Evolved Gas Analyzer (TEGA), which was designed, built and tested at the University of Arizona's Lunar and Planetary Lab (LPL), utilizes DSC/EGA. TEGA, which was sent to Mars on the ill-fated Mars Polar Lander, was to be the first application of DSC/EGA on the surface of Mars as well as the first direct measurement of the volatile-bearing mineralogy in martian soil. Additional information is available in the original extended abstract.

Thermal behaviour and microanalysis of coal subbituminus

NASA Astrophysics Data System (ADS)

Heriyanti; Prendika, W.; Ashyar, R.; Sutrisno

2018-04-01

Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) is used to study the thermal behaviour of sub-bituminous coal. The DSC experiment was performed in air atmosphere up to 125 °C at a heating rate of 25 °C min1. The DSC curve showed that the distinct transitional stages in the coal samples studied. Thermal heating temperature intervals, peak and dissociation energy of the coal samples were also determined. The XRD analysis was used to evaluate the diffraction pattern and crystal structure of the compounds in the coal sample at various temperatures (25-350 °C). The XRD analysis of various temperatures obtained compounds from the coal sample, dominated by quartz (SiO2) and corundum (Al2O3). The increase in temperature of the thermal treatment showed a better crystal formation.

Increased levels of arginine vasotocin and neurophysin during nesting in sea turtles.

PubMed

Figler, R A; MacKenzie, D S; Owens, D W; Licht, P; Amoss, M S

1989-02-01

Arginine vasotocin (AVT) and neurophysin (NP) levels were measured by radioimmunoassay in two species of sea turtle, the olive ridley, Lepidochelys olivacea, and the loggerhead, Caretta caretta, during the brief period of nesting and oviposition. In both species, AVT was low in animals which were not reproductively active. AVT was also low at the time animals emerged from the surf to nest, but increased significantly during oviposition and then declined as the animals returned to the water. NP increased in concert with AVT, also reaching highest levels during oviposition. In both species, however, NP levels remained elevated over prenesting levels at the time of return to the water. These findings are consistent with the hypothesis that an AVT-neurophysin complex is released from the neurohypophysis during nesting, and that AVT is a physiological regulator of oviducal contractions in sea turtles.

Littoral foraging by red phalaropes during spring in the northern Bering Sea

USGS Publications Warehouse

Haney, J. Christopher; Stone, Amy E.

1988-01-01

Phalaropes demonstrate considerable plasticity in their choice of foraging habitats. The Red Phalarope (Phalaropus fulicaria) alternates use of pelagic environments in winter and migration (Taning 1933, Stanford 1953, Briggs et al 1984) with wet tundra habitats during the breeding season (Kistchinski 1975, Mayfield 1979, Ridley 1980). Foods available and taken in littoral zones of the Arctic Ocean in fall have been identified (Conners and Risebrough 1978, Johnson and Richardson 1980), but otherwise little attention has been devoted to the transition between the marine and terrestrial periods of the Red Phalarope’s life history. We report phalarope use of littoral areas during spring in the northern Bering Sea and Kongkok Bay, St. Lawrence Island, Alaska. In addition, we describe phalarope foraging tactics and foods available in the sur zone, emphasizing this form of littoral foraging as an opportunistic and facultative feeding strategy.

Pegasus XL CYGNSS Mission Science Briefing

NASA Image and Video Library

2016-12-10

In the Kennedy Space Center’s Press Site auditorium, NASA and industry leaders speak to members of the media during a mission science briefing for the agency’s Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. From left are: Aaron Ridley, CYGNSS constellation scientist in the Climate and Space Department at the University of Michigan in Ann Arbor, Michigan; and Mary Morris, doctoral student in the Department of Climate and Space Sciences and Engineering at the University of Michigan. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data will help scientists probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a crucial role in the beginning and intensification of hurricanes.

Pegasus XL CYGNSS Mission Science Briefing

NASA Image and Video Library

2016-12-10

In the Kennedy Space Center’s Press Site auditorium, NASA and industry leaders speak to members of the media during a mission science briefing for the agency’s Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. From left are: Dr. Chris Ruf, CYGNSS principal investigator, Department of Climate and Space Sciences and Engineering at the University of Michigan; and Aaron Ridley, CYGNSS constellation scientist in the Climate and Space Department at the University of Michigan in Ann Arbor, Michigan. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data will help scientists probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a crucial role in the beginning and intensification of hurricanes.

KSC-2014-2918

NASA Image and Video Library

2014-06-13

CAPE CANAVERAL, Fla. -- A gopher tortoise lumbers down the roadway at NASA's Kennedy Space Center in Florida. Gopher tortoises are dry-land turtles that live in scrub, dry hammock, pine flatwood, coastal grassland and dune habitats. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. Currently, gopher tortoises are protected in some states by federal law under the Endangered Species Act ESA. The refuge provides a habitat for 14 species federally listed as threatened or endangered, including the leatherback, green, Kemps Ridley, loggerhead and Atlantic hawksbill turtles. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. For more information on the gopher tortoise, visit http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html. Photo credit: NASA/Daniel Casper

Solid state characterization of dehydroepiandrosterone.

PubMed

Chang, L C; Caira, M R; Guillory, J K

1995-10-01

Three polymorphs (forms I-III), a monohydrate (form S2), and three new solvates [4:1 hydrate (form S1), monohydrate (form S3), and methanol half-solvate (form S4)] were isolated and characterized by X-ray powder diffractometry (XRPD), IR spectroscopy, differential scanning calorimetry (DSC), hot stage microscopy, solution calorimetry, and their dissolution rates. A new polymorph, designated as form V, melting at 146.5-148 degrees C, was observed by hot stage microscopy. Our results indicate that only forms I and S4 exhibit reproducible DSC thermograms. Five of the isolated modifications undergo phase transformation on heating, and their DSC thermograms are not reproducible. Interpretation of DSC thermograms was facilitated by use of hot stage microscopy. The identification of each modification is based on XRPD patterns (except forms S3 and S4, for which the XRPD patterns are indistinguishable) and IR spectra. In the IR spectra, a significant difference was observed in the OH stretching region of all seven modifications. In a purity determination study, 5% of a contaminant modification in binary mixtures of several modifications could be detected by use of XRPD. To obtain a better understanding of the thermodynamic properties of these modifications, a series of increasing heating rates and different pan types were used in DSC. According to Burger's rule, forms I-III are monotropic polymorphs with decreasing stability in the order form I > form II > form III. The melting onsets and heats of fusion for forms I-III are 149.1 degrees C, 25.5 kJ/mol; 140.8 degrees C, 24.6 kJ/mol; and 137.8 degrees C, 24.0 kJ/mol, respectively. For form III the heat of fusion was calculated from heat of solution and DSC data. In the case of form S1 the melting point, 127.2 degrees C, was obtained by DSC using a hermetically sealed pan. The relative stabilities of the six modifications stored under high humidity conditions were predicted to be, on the basis of the heat of solution and

Thermal Stability of Otto Fuel Prepolymer

NASA Technical Reports Server (NTRS)

Tompa, Albert S.; Sandagger, Karrie H.; Bryant, William F., Jr.; McConnell, William T.; Lacot, Fernando; Carr, Walter A.

2000-01-01

Otto Fuel II contains a nitrate ester, plasticizer, and 2-NDPA as a stabilizer. Otto Fuel with stabilizers from three vendors was investigated by dynamic and isothermal DSC using samples sealed in a glass ampoule and by Isothermal Microcalorimetry (IMC) using 10 gram samples aged at 75 C for 35 days. DSC kinetics did not show differences between the stabilizer; the samples had an activation energy of 36.7 +/- 0.6 kcal/mol. However, IMC analysis was sensitive enough to detect small differences between the stabilizer, namely energy of interaction values of 7 to 14 Joules. DSC controlled cooling and heating at 5 C/min from 30 to -60 to 40 C experiments were similar and showed a crystallization peak at -48 +/- 1 C during cooling, and upon heating there was a glass transition temperature step at approx. -54 +/- 0.5 C and a melting peak at -28 +/- 0.4 C.

Thermal Stability and Kinetic Study of Fluvoxamine Stability in Binary Samples with Lactose.

PubMed

Ghaderi, Faranak; Nemati, Mahboob; Siahi-Shadbad, Mohammad Reza; Valizadeh, Hadi; Monajjemzadeh, Farnaz

2017-04-01

Purpose: In the present study the incompatibility of FLM (fluvoxamine) with lactose in solid state mixtures was investigated. The compatibility was evaluated using different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy and mass spectrometry. Methods: Non-Isothermally stressed physical mixtures were used to calculate the solid-state kinetic parameters. Different thermal models such as Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) were used for the characterization of the drug-excipient interaction. Results: Overall, the incompatibility of FLM with lactose as a reducing carbohydrate was successfully evaluated and the activation energy of this interaction was calculated. Conclusion: In this research the lactose and FLM Maillard interaction was proved using physicochemical techniques including DSC and FTIR. It was shown that DSC- based kinetic analysis provides fast and versatile kinetic comparison of Arrhenius activation energies for different pharmaceutical samples.

Thermal Stability and Kinetic Study of Fluvoxamine Stability in Binary Samples with Lactose

PubMed Central

Ghaderi, Faranak; Nemati, Mahboob; Siahi-Shadbad, Mohammad Reza; Valizadeh, Hadi; Monajjemzadeh, Farnaz

2017-01-01

Purpose: In the present study the incompatibility of FLM (fluvoxamine) with lactose in solid state mixtures was investigated. The compatibility was evaluated using different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy and mass spectrometry. Methods: Non-Isothermally stressed physical mixtures were used to calculate the solid–state kinetic parameters. Different thermal models such as Friedman, Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) were used for the characterization of the drug-excipient interaction. Results: Overall, the incompatibility of FLM with lactose as a reducing carbohydrate was successfully evaluated and the activation energy of this interaction was calculated. Conclusion: In this research the lactose and FLM Maillard interaction was proved using physicochemical techniques including DSC and FTIR. It was shown that DSC- based kinetic analysis provides fast and versatile kinetic comparison of Arrhenius activation energies for different pharmaceutical samples. PMID:28507936

The characterization of copper alloys for the application of fusion reactors

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

Ishiyama, S.; Fukaya, K.; Eto, M.

Three kinds of candidate copper alloys for divertor structural materials of fusion experimental reactors, that is, Oxygen Free High thermal conductivity Copper (OFHC), alumina disperse reinforced copper (DSC) and the composite of W and Cu (W/Cu), were prepared for strength and fatigue tests at temperatures ranging from R.T. to 500 C in a vacuum. High temperature strength of DSC and W/Cu with rapid fracture after peak loading at the temperatures is higher than that of OFHC by factor of 2, but fracture strains of DFC and W/Cu are smaller than that of OFHC. Fatigue life of DSC, which shows themore » same fatigue behavior of OFHC at room temperature, is longer than other materials at 400 C. Remarkable fatigue life reduction of OFHC found in this experiment is to be due to recrystallization of OFHC yielded above 400 C.« less

Influence of supercritical CO(2) pressurization on the phase behavior of mixed cholesteryl esters.

PubMed

Huang, Zhen; Feng, Mei; Su, Junfeng; Guo, Yuhua; Liu, Tie-Yan; Chiew, Yee C

2010-09-15

Evidences indicating the presence of phase transformations in the mixed cholesteryl benzoate (CBE) and cholesteryl butyrate (CBU) under the supercritical CO(2) pressurization, by means of differential scanning calorimetry (DSC) and X-ray diffraction (XRD), are presented in this work. These include (1) the DSC heating curve of pure CBU; (2) the DSC heating curves of CBU/CBE mixtures; (3) the XRD spectra of pure CBU; (4) the XRD spectra of CBU/CBE mixtures; (5) CBU and CBE are miscible in either solid phase or liquid phase over the whole composition range. As a result of the presence of these phase transformations induced by pressurization, it could be deduced that a solid solution of the CBU/CBE mixture might have formed at the interfaces under supercritical conditions, subsequently influencing their dissolving behaviors in supercritical CO(2). Copyright 2010 Elsevier B.V. All rights reserved.

Soil organic matter composition from correlated thermal analysis and nuclear magnetic resonance data in Australian national inventory of agricultural soils

NASA Astrophysics Data System (ADS)

Moore, T. S.; Sanderman, J.; Baldock, J.; Plante, A. F.

2016-12-01

National-scale inventories typically include soil organic carbon (SOC) content, but not chemical composition or biogeochemical stability. Australia's Soil Carbon Research Programme (SCaRP) represents a national inventory of SOC content and composition in agricultural systems. The program used physical fractionation followed by 13C nuclear magnetic resonance (NMR) spectroscopy. While these techniques are highly effective, they are typically too expensive and time consuming for use in large-scale SOC monitoring. We seek to understand if analytical thermal analysis is a viable alternative. Coupled differential scanning calorimetry (DSC) and evolved gas analysis (CO2- and H2O-EGA) yields valuable data on SOC composition and stability via ramped combustion. The technique requires little training to use, and does not require fractionation or other sample pre-treatment. We analyzed 300 agricultural samples collected by SCaRP, divided into four fractions: whole soil, coarse particulates (POM), untreated mineral associated (HUM), and hydrofluoric acid (HF)-treated HUM. All samples were analyzed by DSC-EGA, but only the POM and HF-HUM fractions were analyzed by NMR. Multivariate statistical analyses were used to explore natural clustering in SOC composition and stability based on DSC-EGA data. A partial least-squares regression (PLSR) model was used to explore correlations among the NMR and DSC-EGA data. Correlations demonstrated regions of combustion attributable to specific functional groups, which may relate to SOC stability. We are increasingly challenged with developing an efficient technique to assess SOC composition and stability at large spatial and temporal scales. Correlations between NMR and DSC-EGA may demonstrate the viability of using thermal analysis in lieu of more demanding methods in future large-scale surveys, and may provide data that goes beyond chemical composition to better approach quantification of biogeochemical stability.

Research on choleretic effect of menthol, menthone, pluegone, isomenthone, and limonene in DanShu capsule.

PubMed

Hu, Guanying; Yuan, Xing; Zhang, Sanyin; Wang, Ruru; Yang, Miao; Wu, Chunjie; Wu, Zhigang; Ke, Xiao

2015-02-01

Danshu capsule (DSC) is a medicinal compound in traditional Chinese medicine (TCM). It is commonly used for the treatment of acute & chronic cholecystitis as well as choleithiasis. To study its choleretic effect, healthy rats were randomly divided into DSC high (DSCH, 900mg/kg), medium (DSCM, 450mg/kg), and low (DSCL, 225mg/kg) group, Xiaoyan Lidan tablet (XYLDT, 750mg/kg), and saline group. The bile was collected for 1h after 20-minute stabilization as the base level, and at 1h, 2h, 3h, and 4h after drug administration, respectively. Bile volume, total cholesterol, and total bile acid were measured at each time point. The results revealed that DSC significantly stimulated bile secretion, decreased total cholesterol level and increased total bile acid level. Therefore, it had choleretic effects. To identify the active components contributing to its choleretic effects, five major constituents which are menthol (39.33mg/kg), menthone (18.02mg/kg), isomenthone (8.18mg/kg), pluegone (3.31mg/kg), and limonene (4.39mg/kg) were tested on our rat model. The results showed that menthol and limonene could promote bile secretion when compared to DSC treatment (p > 0.05); Menthol, menthol and limonene could significantly decrease total cholesterol level (p<0.05 or p<0.01) as well as increase total bile acid level (p<0.05 or p<0.01); Isomenthone, as a isomer of menthone, existed slightly choleretic effects; Pluegone had no obvious role in bile acid efflux. These findings indicated that the choleretic effects of DSC may be attributed mainly to its three major constituents: menthol, menthone and limonene. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Comparison of [{sup 11}C]choline Positron Emission Tomography With T2- and Diffusion-Weighted Magnetic Resonance Imaging for Delineating Malignant Intraprostatic Lesions

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

Chang, Joe H.; University of Melbourne, Victoria; Lim Joon, Daryl

2015-06-01

Purpose: The purpose of this study was to compare the accuracy of [{sup 11}C]choline positron emission tomography (CHOL-PET) with that of the combination of T2-weighted and diffusion-weighted (T2W/DW) magnetic resonance imaging (MRI) for delineating malignant intraprostatic lesions (IPLs) for guiding focal therapies and to investigate factors predicting the accuracy of CHOL-PET. Methods and Materials: This study included 21 patients who underwent CHOL-PET and T2W/DW MRI prior to radical prostatectomy. Two observers manually delineated IPL contours for each scan, and automatic IPL contours were generated on CHOL-PET based on varying proportions of the maximum standardized uptake value (SUV). IPLs identified onmore » prostatectomy specimens defined reference standard contours. The imaging-based contours were compared with the reference standard contours using Dice similarity coefficient (DSC), and sensitivity and specificity values. Factors that could potentially predict the DSC of the best contouring method were analyzed using linear models. Results: The best automatic contouring method, 60% of the maximum SUV (SUV{sub 60}) , had similar correlations (DSC: 0.59) with the manual PET contours (DSC: 0.52, P=.127) and significantly better correlations than the manual MRI contours (DSC: 0.37, P<.001). The sensitivity and specificity values were 72% and 71% for SUV{sub 60}; 53% and 86% for PET manual contouring; and 28% and 92% for MRI manual contouring. The tumor volume and transition zone pattern could independently predict the accuracy of CHOL-PET. Conclusions: CHOL-PET is superior to the combination of T2W/DW MRI for delineating IPLs. The accuracy of CHOL-PET is insufficient for gland-sparing focal therapies but may be accurate enough for focal boost therapies. The transition zone pattern is a new classification that may predict how well CHOL-PET delineates IPLs.« less

Towards quantitative imaging: stability of fully automated nodule segmentation across varied dose levels and reconstruction parameters in a low-dose CT screening patient cohort

NASA Astrophysics Data System (ADS)

Wahi-Anwar, M. Wasil; Emaminejad, Nastaran; Hoffman, John; Kim, Grace H.; Brown, Matthew S.; McNitt-Gray, Michael F.

2018-02-01

Quantitative imaging in lung cancer CT seeks to characterize nodules through quantitative features, usually from a region of interest delineating the nodule. The segmentation, however, can vary depending on segmentation approach and image quality, which can affect the extracted feature values. In this study, we utilize a fully-automated nodule segmentation method - to avoid reader-influenced inconsistencies - to explore the effects of varied dose levels and reconstruction parameters on segmentation. Raw projection CT images from a low-dose screening patient cohort (N=59) were reconstructed at multiple dose levels (100%, 50%, 25%, 10%), two slice thicknesses (1.0mm, 0.6mm), and a medium kernel. Fully-automated nodule detection and segmentation was then applied, from which 12 nodules were selected. Dice similarity coefficient (DSC) was used to assess the similarity of the segmentation ROIs of the same nodule across different reconstruction and dose conditions. Nodules at 1.0mm slice thickness and dose levels of 25% and 50% resulted in DSC values greater than 0.85 when compared to 100% dose, with lower dose leading to a lower average and wider spread of DSC values. At 0.6mm, the increased bias and wider spread of DSC values from lowering dose were more pronounced. The effects of dose reduction on DSC for CAD-segmented nodules were similar in magnitude to reducing the slice thickness from 1.0mm to 0.6mm. In conclusion, variation of dose and slice thickness can result in very different segmentations because of noise and image quality. However, there exists some stability in segmentation overlap, as even at 1mm, an image with 25% of the lowdose scan still results in segmentations similar to that seen in a full-dose scan.

Comparison of Clinical Results and Injury Risk of Posterior Tibial Cortex Between Attune and Press Fit Condylar Sigma Knee Systems.

PubMed

Song, Sang Jun; Park, Cheol Hee; Liang, Hu; Kang, Se Gu; Park, Jong Jun; Bae, Dae Kyung

2018-02-01

We compared clinical and radiographic results after total knee arthroplasty (TKA) using Attune and Press Fit Condylar Sigma, and investigated whether use of the current prosthesis increased injury risk to the tibial cortex in Asian patients. We also assessed whether a preoperative posterior tibial slope angle (PSA) is associated with the injury when using the current prosthesis. The 300 TKAs with Attune (group A) were compared to the 300 TKAs with Press Fit Condylar Sigma (group B). Demographics were not different, except follow-up periods (24.8 vs 33.3 months, P < .001). The Western Ontario and McMaster Universities Index and range of motion were compared. A minimum distance between tibial component stem and posterior tibial cortex (mDSC) was compared. The correlation between preoperative PSA and mDSC was analyzed in group A. The postoperative Western Ontario and McMaster Universities Index and range of motion of group A were better than those of group B (17.7 vs 18.8, P = .004; 131.4° vs 129.0°, P = .008). The mDSC was shorter in group A (6.3 vs 7.0 mm, P < .001), which made up a higher proportion of the high-risk group for posterior tibial cortical injury with an mDSC of <4 mm (20.0% vs 10.7%, P = .002). A negative correlation was found between the preoperative PSA and mDSC in group A (r = -0.205, P < .001). The TKA using the current prosthesis provided more satisfactory results than the TKA using the previous prosthesis. However, the injury risk to the posterior tibial cortex increased in the knees with a large PSA when using the current prosthesis for Asian patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Mechanisms of fibrinogen-acebutolol interactions: Insights from DSC, CD and LS.

PubMed

Hassan, Natalia; Ruso, Juan M; Somasundaran, P

2011-02-01

The complex formed due to the interaction of the amphiphilic betablocker acebutolol with fibrinogen in a buffer solution (50mN glycine, pH of 8.5) has been investigated using a multipronged physicochemical approach. Differential scanning calorimetry measurements of the complexes have shown no reversibility of thermal denaturation as indicated by the three observed peaks and the opposite role that acebutolol plays in the folding different domains of the fibrinogen molecule and the stability of such domains. While circular dichroism measurements have revealed that interaction of acebutolol with fibrinogen affects the protein secondary structure to a different extent depending on the temperature and drug concentration, dynamic light scattering analysis showed evidence for protein aggregation mainly to tetramers and dimers. Copyright © 2010 Elsevier B.V. All rights reserved.

Detection of Collapse and Crystallization of Saccharide, Protein, and Mannitol Formulations by Optical Fibers in Lyophilization

PubMed Central

Horn, Jacqueline; Friess, Wolfgang

2018-01-01

The collapse temperature (Tc) and the glass transition temperature of freeze-concentrated solutions (Tg') as well as the crystallization behavior of excipients are important physicochemical characteristics which guide the cycle development in freeze-drying. The most frequently used methods to determine these values are differential scanning calorimetry (DSC) and freeze-drying microscopy (FDM). The objective of this study was to evaluate the optical fiber system (OFS) unit as alternative tool for the analysis of Tc, Tg' and crystallization events. The OFS unit was also tested as a potential online monitoring tool during freeze-drying. Freeze/thawing and freeze-drying experiments of sucrose, trehalose, stachyose, mannitol, and highly concentrated IgG1 and lysozyme solutions were carried out and monitored by the OFS. Comparative analyses were performed by DSC and FDM. OFS and FDM results correlated well. The crystallization behavior of mannitol could be monitored by the OFS during freeze/thawing as it can be done by DSC. Online monitoring of freeze-drying runs detected collapse of amorphous saccharide matrices. The OFS unit enabled the analysis of both Tc and crystallization processes, which is usually carried out by FDM and DSC. The OFS can hence be used as novel measuring device. Additionally, detection of these events during lyophilization facilitates online-monitoring. Thus the OFS is a new beneficial tool for the development and monitoring of freeze-drying processes. PMID:29435445

Progress on the DPASS project

NASA Astrophysics Data System (ADS)

Galkin, Sergei A.; Bogatu, I. N.; Svidzinski, V. A.

2015-11-01

A novel project to develop Disruption Prediction And Simulation Suite (DPASS) of comprehensive computational tools to predict, model, and analyze disruption events in tokamaks has been recently started at FAR-TECH Inc. DPASS will eventually address the following aspects of the disruption problem: MHD, plasma edge dynamics, plasma-wall interaction, generation and losses of runaway electrons. DPASS uses the 3-D Disruption Simulation Code (DSC-3D) as a core tool and will have a modular structure. DSC is a one fluid non-linear, time-dependent 3D MHD code to simulate dynamics of tokamak plasma surrounded by pure vacuum B-field in the real geometry of a conducting tokamak vessel. DSC utilizes the adaptive meshless technique with adaptation to the moving plasma boundary, with accurate magnetic flux conservation and resolution of the plasma surface current. DSC has also an option to neglect the plasma inertia to eliminate fast magnetosonic scale. This option can be turned on/off as needed. During Phase I of the project, two modules will be developed: the computational module for modeling the massive gas injection and main plasma respond; and the module for nanoparticle plasma jet injection as an innovative disruption mitigation scheme. We will report on this development progress. Work is supported by the US DOE SBIR grant # DE-SC0013727.

Detection of Collapse and Crystallization of Saccharide, Protein and Mannitol Formulations by Optical Fibers in Lyophilization

NASA Astrophysics Data System (ADS)

Horn, Jacqueline; Friess, Wolfgang

2018-01-01

The collapse temperature (Tc) and the glass transition temperature of freeze-concentrated solutions (Tg’) as well as the crystallization behavior of excipients are important physicochemical characteristics which guide the cycle development in freeze-drying. The most frequently used methods to determine these values are differential scanning calorimetry (DSC) and freeze-drying microscopy (FDM). The objective of this study was to evaluate the optical fiber system (OFS) unit as alternative tool for the analysis of Tc, Tg’ and crystallization events. The OFS unit was also tested as a potential online monitoring tool during freeze-drying. Freeze/thawing and freeze-drying experiments of sucrose, trehalose, stachyose, mannitol and highly concentrated IgG1 and lysozyme solutions were carried out and monitored by the OFS. Comparative analyses were performed by DSC and FDM. OFS and FDM results correlated well. The crystallization behavior of mannitol could be monitored by the OFS during freeze/thawing as it can be done by DSC. Online monitoring of freeze-drying runs detected collapse of amorphous saccharide matrices. The OFS unit enabled the analysis of both Tc and crystallization processes, which is usually carried out by FDM and DSC. The OFS can hence be used as novel measuring device. Additionally, detection of these events during lyophilization facilitate online-monitoring. Thus the OFS is a new beneficial tool for the development and monitoring of freeze-drying processes.

Physical Properties of Hydrogenated Dimers of Norbornadiene and Exo-Tetrahydrodicyclopentadiene and their Mixtures

DTIC Science & Technology

1977-12-01

structures of these com- pounds are shown in Fig. 1, along with the abbreviations (HXX, XTHDCPD , etc.) by which they will be referred to in the...crystal because of the difficulty in obtaining good DSC data at the very low temperatures below the XTHDCPD melting point. The four NBD hydrogenated...estimated from the DSC fusion curve, was used for ACpf for XTHDCPD . The results of these calculations are shown in Fig. 3 as plots of Ti (in K and *F) versus

High Performance Composites Based on Polyurethanes Reinforced with Polydiacetylenes

DTIC Science & Technology

1989-04-04

Mv Niax triol LHT240 (ex. Union Carbide) is a polyoxypropylene adduct of 1,2,6- hexanetriol and after drying by rotary film evaporation had an...hompolyurethane hard segment material, HDD/MDI, which has been quench -cooled from 280 to -1000C: after DSC measurement on the same material giving the...feature in the DSC curves fig 15(c) for HDD/MDI is the development of a glass-transition at 8500 in curve B’ following quench -cooling. The ladder-like, hard

Final report for tank 241-AP-108, grab samples 8AP-96-1, 8AP-96-2 and 8AP-96-FB

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

Esch, R.A.

1996-04-19

This document is the final report deliverable for the tank 241-AP-108 grab samples. The samples were subsampled and analyzed in accordance with the TSAP. Included in this report are the results for the Waste Compatibility analyses, with the exception of DSC and thermogravimetric analysis (TGA) results which were presented in the 45 Day report (Part 2 of this document). The raw data for all analyses, with the exception of DSC and TGA, are also included in this report.

Protecting Location Privacy for Outsourced Spatial Data in Cloud Storage

PubMed Central

Gui, Xiaolin; An, Jian; Zhao, Jianqiang; Zhang, Xuejun

2014-01-01

As cloud computing services and location-aware devices are fully developed, a large amount of spatial data needs to be outsourced to the cloud storage provider, so the research on privacy protection for outsourced spatial data gets increasing attention from academia and industry. As a kind of spatial transformation method, Hilbert curve is widely used to protect the location privacy for spatial data. But sufficient security analysis for standard Hilbert curve (SHC) is seldom proceeded. In this paper, we propose an index modification method for SHC (SHC∗) and a density-based space filling curve (DSC) to improve the security of SHC; they can partially violate the distance-preserving property of SHC, so as to achieve better security. We formally define the indistinguishability and attack model for measuring the privacy disclosure risk of spatial transformation methods. The evaluation results indicate that SHC∗ and DSC are more secure than SHC, and DSC achieves the best index generation performance. PMID:25097865

Water absorption of freeze-dried meat at different water activities: a multianalytical approach using sorption isotherm, differential scanning calorimetry, and nuclear magnetic resonance.

PubMed

Venturi, Luca; Rocculi, Pietro; Cavani, Claudio; Placucci, Giuseppe; Dalla Rosa, Marco; Cremonini, Mauro A

2007-12-26

Hydration of freeze-dried chicken breast meat was followed in the water activity range of aw=0.12-0.99 by a multianalytical approach comprising of sorption isotherm, differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). The amount of frozen water and the shape of the T2-relaxogram were evaluated at each water content by DSC and NMR, respectively. Data revealed an agreement between sorption isotherm and DSC experiments about the onset of bulk water (aw=0.83-0.86), and NMR detected mobile water starting at aw=0.75. The origin of the short-transverse relaxation time part of the meat NMR signal was also reinvestigated through deuteration experiments and proposed to arise from protons belonging to plasticized matrix structures. It is proved both by D2O experiments and by gravimetry that the extra protons not contributing to the water content in the NMR experiments are about 6.4% of the total proton NMR CPMG signal of meat.

Thermal Stability of Otto Fuel Prepolymer

NASA Technical Reports Server (NTRS)

Tompa, Albert S.; Sandagger, Karrie H.; Bryant, William F., Jr.; McConnell, William T.; Lacot, Fernando; Carr, Walter A.

2000-01-01

Otto Fuel II contains a nitrate ester, plasticizer, and 2-NPDA as a stabilizer. Otto Fuel with stabilizers from three vendors was investigated by dynamic and isothermal differential scanning calorimetry (DSC) using samples sealed in a glass ampoule and by Isothermal Microcalorimetry (IMC) using 10 gram samples aged at 75 C for 35 days. DSC kinetics did not show differences between the stabilizer; the samples had an activation energy of 36.7 +/- 0.6 kcal/mol. However, IMC analysis was sensitive enough to detect small differences between the stabilizer, namely energy of interaction values of 7 to 14 Joules. DSC controlled cooling and heating at 5 C/min from 30 to -60 to 40 C experiments were similar and showed a crystallization peak at -48 +/- 1 C during cooling, and upon heating there was a glass transition temperature step at approx. -54 +/- 0.5 C and a melting peak at -28 +/- 0.4 C.

Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

NASA Astrophysics Data System (ADS)

Aydınlı, Bahattin; Tin c̡er, Teoman

2001-10-01

Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60°C and they became clearer at a higher grafting level. In the second run of DSC some Tg values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

Protecting location privacy for outsourced spatial data in cloud storage.

PubMed

Tian, Feng; Gui, Xiaolin; An, Jian; Yang, Pan; Zhao, Jianqiang; Zhang, Xuejun

2014-01-01

As cloud computing services and location-aware devices are fully developed, a large amount of spatial data needs to be outsourced to the cloud storage provider, so the research on privacy protection for outsourced spatial data gets increasing attention from academia and industry. As a kind of spatial transformation method, Hilbert curve is widely used to protect the location privacy for spatial data. But sufficient security analysis for standard Hilbert curve (SHC) is seldom proceeded. In this paper, we propose an index modification method for SHC (SHC(∗)) and a density-based space filling curve (DSC) to improve the security of SHC; they can partially violate the distance-preserving property of SHC, so as to achieve better security. We formally define the indistinguishability and attack model for measuring the privacy disclosure risk of spatial transformation methods. The evaluation results indicate that SHC(∗) and DSC are more secure than SHC, and DSC achieves the best index generation performance.

Long noncoding RNAs in digestive system cancers: Functional roles, molecular mechanisms, and clinical implications (Review).

PubMed

Fu, Min; Zou, Chen; Pan, Lei; Liang, Wei; Qian, Hui; Xu, Wenrong; Jiang, Pengcheng; Zhang, Xu

2016-09-01

Long noncoding RNAs (lncRNAs) are emerging as new players in various diseases including cancer. LncRNAs have been shown to play multifaceted roles in the development, progression, and metastasis of cancer. In this review, we highlight the lncRNAs that are critically involved in the pathogenesis of digestive system cancers (DSCs). We summarize the roles of the lncRNAs in DSCs and the underlying mechanisms responsible for their functions. The DSC-associated lncRNAs interact with a wide spectrum of molecules to regulate gene expression at transcriptional, post-transcriptional, and translational levels. We also provide new insights into the clinical significance of these lncRNAs, which are found to be closely associated with the aggressiveness of DSCs and could predict the prognosis of DSC patients. Moreover, lncRNAs have been suggested as promising therapeutic targets in DSCs. Therefore, better understanding of the functional roles of lncRNAs will provide new biomarkers for DSC diagnosis, prognosis, and therapy.

Study of the Thermal Polymerization of Linseed and Passion Fruit Oils

NASA Astrophysics Data System (ADS)

Lopes, R. V. V.; Loureiro, N. P. D.; Fonseca, P. S.; Macedo, J. L.; Santos, M. L.; Sales, M. J.

2008-08-01

Researches involving ecofriendliness materials are growing up, as well as, a current interest in developing materials from inexpensive and renewable resources. Vegetable oils show a number of excellent properties, which could be utilized to produce valuable polymeric materials. In this work is described the synthesis of polymeric materials from linseed oil (Linum usitatissimum L.) and passion fruit oil (Passiflora edulis) and their characterization by thermogravimetry (TG), differential scanning calorimetry (DSC) and Raman spectroscopy. The TG curve shows that those polymeric materials present two stages of decomposition. DSC plots of the vegetable oils showed some endothermic and exothermic transitions which are not present in the DSC curves corresponding to oil-based polymers. The Raman spectra of the polymers indicate declining of absorbance in the region of C = C stretching (˜1600 cm-1). This absorption was used to estimate the degree of polymerization (79% and 67.5% for linseed and passion fruit oils, respectively)

Testing the Multispecimen Absolute Paleointensity Method with Archaeological Baked Clays and Bricks: New Data for Central Europe

NASA Astrophysics Data System (ADS)

Schnepp, Elisabeth; Leonhardt, Roman

2014-05-01

The domain-state corrected multiple-specimen paleointensity determination technique (MSP-DSC, Fabian & Leonhardt, EPSL 297, 84, 2010) has been tested for archaeological baked clays and bricks. The following procedure was applied: (1) Exclusion of secondary overprints using alternating field (AF) or thermal demagnetization and assignment of characteristic remanent magnetization (ChRM) direction. (2) Determination of magneto mineralogical alteration using anhysteretic remanent magnetization (ARM) or temperature dependence of susceptibility. (3) Measurement of ARM anisotropy tensor, calculation of the ancient magnetic field direction. (4) Sister specimens were subjected to the MSP-DSC technique aligned (anti-)parallel to the ancient magnetic field direction. (5) Several checks were applied in order to exclude data points from further evaluation: (a) The accuracy of orientation (< 10°), (b) absence of secondary components (< 10°), (c) use of a considerable NRM fraction (20 to 80%), (d) weak alteration (smaller than for domain state change) and finally (e) domain state correction was applied. Bricks and baked clays from archaeological sites with ages between 645 BC and 2003 AD have been subjected to MSP-DSC absolute paleointensity (PI) determination. Aims of study are to check precision and reliability of the method. The obtained PI values are compared with direct field observation, the IGRF, the GUFM1 or Thellier results. The Thellier experiments often show curved lines and pTRM checks fail for higher temperatures. Nevertheless in the low temperature range straight lines have been obtained but they provide scattered paleointensity values. Mean paleointensites have relative errors often exceeding 10%, which are not considered as high quality PI estimates. MSP-DSC experiments for the structures older than 300 years are still under progress. The paleointensities obtained from the MSP-DSC experiments for the young materials (after 1700 AD) have small relative errors of a

Math anxiety: A review of its cognitive consequences, psychophysiological correlates, and brain bases.

PubMed

Suárez-Pellicioni, Macarena; Núñez-Peña, María Isabel; Colomé, Àngels

2016-02-01

A decade has passed since the last published review of math anxiety, which was carried out by Ashcraft and Ridley (2005). Given the considerable interest aroused by this topic in recent years and the growing number of publications related to it, the present article aims to provide a full and updated review of the field, ranging from the initial studies of the impact of math anxiety on numerical cognition, to the latest research exploring its electrophysiological correlates and brain bases from a cognitive neuroscience perspective. Finally, this review describes the factors and mechanisms that have been claimed to play a role in the origins and/or maintenance of math anxiety, and it examines in detail the main explanations proposed to account for the negative effects of math anxiety on performance: competition for working memory resources, a deficit in a low-level numerical representation, and inhibition/attentional control deficit.

KSC-2014-2917

NASA Image and Video Library

2014-06-13

CAPE CANAVERAL, Fla. -- This gopher tortoise almost seems to float above the pavement as it hastens along the road at NASA's Kennedy Space Center in Florida. Gopher tortoises are dry-land turtles that live in scrub, dry hammock, pine flatwood, coastal grassland and dune habitats. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. Currently, gopher tortoises are protected in some states by federal law under the Endangered Species Act ESA. The refuge provides a habitat for 14 species federally listed as threatened or endangered, including the leatherback, green, Kemps Ridley, loggerhead and Atlantic hawksbill turtles. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. For more information on the gopher tortoise, visit http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html. Photo credit: NASA/Daniel Casper

KSC-2014-2854

NASA Image and Video Library

2014-06-04

CAPE CANAVERAL, Fla. -- A gopher tortoise stops for lunch beside the Launch Pad 39B beach road on NASA's Kennedy Space Center in Florida. Gopher tortoises are dry-land turtles that live in scrub, dry hammock, pine flatwood, coastal grassland and dune habitats. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. Currently, gopher tortoises are protected in some states by federal law under the Endangered Species Act ESA. The refuge provides a habitat for 14 species federally listed as threatened or endangered, including the leatherback, green, Kemps Ridley, loggerhead and Atlantic hawksbill turtles. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. For more information on the gopher tortoise, visit http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html. Photo credit: NASA/Daniel Casper

KSC-2014-2852

NASA Image and Video Library

2014-06-04

CAPE CANAVERAL, Fla. -- A gopher tortoise ambles along the Launch Pad 39B beach road on NASA's Kennedy Space Center in Florida. Gopher tortoises are dry-land turtles that live in scrub, dry hammock, pine flatwood, coastal grassland and dune habitats. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. Currently, gopher tortoises are protected in some states by federal law under the Endangered Species Act ESA. The refuge provides a habitat for 14 species federally listed as threatened or endangered, including the leatherback, green, Kemps Ridley, loggerhead and Atlantic hawksbill turtles. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. For more information on the gopher tortoise, visit http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html. Photo credit: NASA/Daniel Casper

Marine turtles of the Gal?pagos Islands and adjacent areas of the eastern Pacific on the basis of observations made by J.R. Slevin 1905-1906

USGS Publications Warehouse

Fritts, T.H.

1981-01-01

The field notes of J. R. Slevin written during the expedition of the California Academy of Sciences to the Galapagos Islands in 1905-1096 contain previously unavailable data on the marine turtles of the eastern Pacific. 'Land basking' by green turtles in Galapagos was predominately, if not exclusively, a female behavior. These terrestrial emergences were not concentrated in the major reproductive season of Galapagos turtles. Female Chelonia were also collected on shore during daylight hours on Socorro Island southwest of Baja California, Mexico. Chelonia, green turtles, were observed to feed on seaweed, the leaves and shoots of mangrove trees, and the leaves of another unidentified shoreline shrub. Comparative data on the gonads of dark and yellow turtles indicated that the latter did not breed in Galapagos during Slevin's stay. Lepidochelys olivacea, the olive ridley, was recorded in Galapagos waters and fed on fish eggs

Comparison of atlas-based techniques for whole-body bone segmentation.

PubMed

Arabi, Hossein; Zaidi, Habib

2017-02-01

We evaluate the accuracy of whole-body bone extraction from whole-body MR images using a number of atlas-based segmentation methods. The motivation behind this work is to find the most promising approach for the purpose of MRI-guided derivation of PET attenuation maps in whole-body PET/MRI. To this end, a variety of atlas-based segmentation strategies commonly used in medical image segmentation and pseudo-CT generation were implemented and evaluated in terms of whole-body bone segmentation accuracy. Bone segmentation was performed on 23 whole-body CT/MR image pairs via leave-one-out cross validation procedure. The evaluated segmentation techniques include: (i) intensity averaging (IA), (ii) majority voting (MV), (iii) global and (iv) local (voxel-wise) weighting atlas fusion frameworks implemented utilizing normalized mutual information (NMI), normalized cross-correlation (NCC) and mean square distance (MSD) as image similarity measures for calculating the weighting factors, along with other atlas-dependent algorithms, such as (v) shape-based averaging (SBA) and (vi) Hofmann's pseudo-CT generation method. The performance evaluation of the different segmentation techniques was carried out in terms of estimating bone extraction accuracy from whole-body MRI using standard metrics, such as Dice similarity (DSC) and relative volume difference (RVD) considering bony structures obtained from intensity thresholding of the reference CT images as the ground truth. Considering the Dice criterion, global weighting atlas fusion methods provided moderate improvement of whole-body bone segmentation (DSC= 0.65 ± 0.05) compared to non-weighted IA (DSC= 0.60 ± 0.02). The local weighed atlas fusion approach using the MSD similarity measure outperformed the other strategies by achieving a DSC of 0.81 ± 0.03 while using the NCC and NMI measures resulted in a DSC of 0.78 ± 0.05 and 0.75 ± 0.04, respectively. Despite very long computation time, the extracted

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

Guener, M.; Gueler, E.; Aktas, H.

Kinetic, morphological and some thermal properties of thermally induced and deformation-induced martensite were studied in a Fe-32%Ni-0.4%Cr alloy. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and compression deformation test techniques were used for these studies. SEM observations revealed the occurrence of both athermal and isothermal martensitic transformation kinetics for producing a lenticular martensite morphology for different homogenization conditions of the prior austenite phase. The DSC measurement results showed a fair agreement with those of previous studies on ferrous alloys.

Metastable and equilibrium phase formation in sputter-deposited Ti/Al multilayer thin films

NASA Astrophysics Data System (ADS)

Lucadamo, G.; Barmak, K.; Lavoie, C.; Cabral, C., Jr.; Michaelsen, C.

2002-06-01

The sequence and kinetics of metastable and equilibrium phase formation in sputter deposited multilayer thin films was investigated by combining in situ synchrotron x-ray diffraction (XRD) with ex situ electron diffraction and differential scanning calorimetry (DSC). The sequence included both cubic and tetragonal modifications of the equilibrium TiAl3 crystal structure. Values for the formation activation energies of the various phases in the sequence were determined using the XRD and DSC data obtained here, as well as activation energy data reported in the literature.

A Proposed Mechanism for the Thermal Denaturation of a Recombinant Bacillus Halmapalus Alpha-amylase - the Effect of Calcium Ions

NASA Technical Reports Server (NTRS)

Nielsen, Anders D.; Pusey, Marc L.; Fuglsang, Claus C.; Westh, Peter

2003-01-01

The thermal stability of a recombinant alpha-amylase from Bacillus halmapalus alpha-amylase (BHA) has been investigated using circular dichroism spectroscopy (CD) and differential scanning calorimetry (DSC). This alpha-amylase is homologous to other Bacillus alpha-amylases where previous crystallographic studies have identified the existence of 3 calcium binding sites in the structure. Denaturation of BHA is irreversible with a Tm of approximately 89 C, and DSC thermograms can be described using a one-step irreversible model. A 5 C increase in T(sub m) in the presence of 10 fold excess CaCl2 was observed. However, a concomitant increase in the tendency to aggregate was also observed. The presence of 30-40 fold excess calcium chelator (EDTA or EGTA) results in a large destabilization of BHA corresponding to about 40 C lower T(sub m), as determined by both CD and DSC. Ten fold excess EGTA reveals complex DSC thermograms corresponding to both reversible and irreversible transitions, which possibly originate from different populations of BHA:calcium complexes. The observations in the present study have, in combination with structural information of homologous alpha-amylases, provided the basis for the proposal of a simple denaturation mechanism of BHA. The proposed mechanism describes the irreversible thermal denaturation of different BHA:calcium complexes and the calcium binding equilibrium involved. Furthermore, the model accounts for a temperature induced reversible structural change associated with calcium binding.

Brain perfusion alterations in tick-borne encephalitis-preliminary report.

PubMed

Tyrakowska-Dadełło, Zuzanna; Tarasów, Eugeniusz; Janusek, Dariusz; Moniuszko-Malinowska, Anna; Zajkowska, Joanna; Pancewicz, Sławomir

2018-03-01

Magnetic resonance imaging (MRI) changes in tick-borne encephalitis (TBE) are non-specific and the pathophysiological mechanisms leading to their formation remain unclear. This study investigated brain perfusion in TBE patients using dynamic susceptibility-weighted contrast-enhanced magnetic resonance perfusion imaging (DSC-MRI perfusion). MRI scans were performed for 12 patients in the acute phase, 3-5days after the diagnosis of TBE. Conventional MRI and DSC-MRI perfusion studies were performed. Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) parametric maps were created. The bilateral frontal, parietal, and temporal subcortical regions and thalamus were selected as regions of interest. Perfusion parameters of TBE patients were compared to those of a control group. There was a slight increase in CBF and CBV, with significant prolongation of TTP in subcortical areas in the study subjects, while MTT values were comparable to those of the control group. A significant increase in thalamic CBF (p<0.001) and increased CBV (p<0.05) were observed. Increased TTP and a slight reduction in MTT were also observed within this area. The DSC-MRI perfusion study showed that TBE patients had brain perfusion disturbances, expressed mainly in the thalami. These results suggest that DSC-MRI perfusion may provide important information regarding the areas affected in TBE patients. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Saccadic interception of a moving visual target after a spatiotemporal perturbation.

PubMed

Fleuriet, Jérome; Goffart, Laurent

2012-01-11

Animals can make saccadic eye movements to intercept a moving object at the right place and time. Such interceptive saccades indicate that, despite variable sensorimotor delays, the brain is able to estimate the current spatiotemporal (hic et nunc) coordinates of a target at saccade end. The present work further tests the robustness of this estimate in the monkey when a change in eye position and a delay are experimentally added before the onset of the saccade and in the absence of visual feedback. These perturbations are induced by brief microstimulation in the deep superior colliculus (dSC). When the microstimulation moves the eyes in the direction opposite to the target motion, a correction saccade brings gaze back on the target path or very near. When it moves the eye in the same direction, the performance is more variable and depends on the stimulated sites. Saccades fall ahead of the target with an error that increases when the stimulation is applied more caudally in the dSC. The numerous cases of compensation indicate that the brain is able to maintain an accurate and robust estimate of the location of the moving target. The inaccuracies observed when stimulating the dSC that encodes the visual field traversed by the target indicate that dSC microstimulation can interfere with signals encoding the target motion path. The results are discussed within the framework of the dual-drive and the remapping hypotheses.

Prospective randomized double-blind study of atlas-based organ-at-risk autosegmentation-assisted radiation planning in head and neck cancer.

PubMed

Walker, Gary V; Awan, Musaddiq; Tao, Randa; Koay, Eugene J; Boehling, Nicholas S; Grant, Jonathan D; Sittig, Dean F; Gunn, Gary Brandon; Garden, Adam S; Phan, Jack; Morrison, William H; Rosenthal, David I; Mohamed, Abdallah Sherif Radwan; Fuller, Clifton David

2014-09-01

Target volumes and organs-at-risk (OARs) for radiotherapy (RT) planning are manually defined, which is a tedious and inaccurate process. We sought to assess the feasibility, time reduction, and acceptability of an atlas-based autosegmentation (AS) compared to manual segmentation (MS) of OARs. A commercial platform generated 16 OARs. Resident physicians were randomly assigned to modify AS OAR (AS+R) or to draw MS OAR followed by attending physician correction. Dice similarity coefficient (DSC) was used to measure overlap between groups compared with attending approved OARs (DSC=1 means perfect overlap). 40 cases were segmented. Mean ± SD segmentation time in the AS+R group was 19.7 ± 8.0 min, compared to 28.5 ± 8.0 min in the MS cohort, amounting to a 30.9% time reduction (Wilcoxon p<0.01). For each OAR, AS DSC was statistically different from both AS+R and MS ROIs (all Steel-Dwass p<0.01) except the spinal cord and the mandible, suggesting oversight of AS/MS processes is required; AS+R and MS DSCs were non-different. AS compared to attending approved OAR DSCs varied considerably, with a chiasm mean ± SD DSC of 0.37 ± 0.32 and brainstem of 0.97 ± 0.03. Autosegmentation provides a time savings in head and neck regions of interest generation. However, attending physician approval remains vital. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Activity in the superior colliculus reflects dynamic interactions between voluntary and involuntary influences on orienting behaviour.

PubMed

Bell, Andrew H; Munoz, Douglas P

2008-10-01

Performance in a behavioural task can be influenced by both bottom-up and top-down processes such as stimulus modality and prior probability. Here, we exploited differences in behavioural strategy to explore the role of the intermediate and deep layers of the superior colliculus (dSC) in covert orienting. Two monkeys were trained on a predictive cued-saccade task in which the cue predicted the target's upcoming location with 80% validity. When the delay between cue and target onset was 250 ms, both monkeys showed faster responses to the uncued (Invalid) location. This was associated with a reduced target-aligned response in the dSC on Valid trials for both monkeys and is consistent with a bottom-up (i.e. involuntary) bias. When the delay was increased to 650 ms, one monkey continued to show faster responses to the Invalid location whereas the other monkey showed faster responses to the Valid location, consistent with a top-down (i.e. voluntary) bias. This latter behaviour was correlated with an increase in activity in dSC neurons preceding target onset that was absent in the other monkey. Thus, using the information provided by the cue shifted the emphasis towards top-down processing, while ignoring this information allowed bottom-up processing to continue to dominate. Regardless of the selected strategy, however, neurons in the dSC consistently reflected the current bias between the two processes, emphasizing its role in both the bottom-up and top-down control of orienting behaviour.

Pushing the Performance Limit of Sub-100 nm Molybdenum Disulfide Transistors.

PubMed

Liu, Yuan; Guo, Jian; Wu, Yecun; Zhu, Enbo; Weiss, Nathan O; He, Qiyuan; Wu, Hao; Cheng, Hung-Chieh; Xu, Yang; Shakir, Imran; Huang, Yu; Duan, Xiangfeng

2016-10-12

Two-dimensional semiconductors (2DSCs) such as molybdenum disulfide (MoS 2 ) have attracted intense interest as an alternative electronic material in the postsilicon era. However, the ON-current density achieved in 2DSC transistors to date is considerably lower than that of silicon devices, and it remains an open question whether 2DSC transistors can offer competitive performance. A high current device requires simultaneous minimization of the contact resistance and channel length, which is a nontrivial challenge for atomically thin 2DSCs, since the typical low contact resistance approaches for 2DSCs either degrade the electronic properties of the channel or are incompatible with the fabrication process for short channel devices. Here, we report a new approach toward high-performance MoS 2 transistors by using a physically assembled nanowire as a lift-off mask to create ultrashort channel devices with pristine MoS 2 channel and self-aligned low resistance metal/graphene hybrid contact. With the optimized contact in short channel devices, we demonstrate sub-100 nm MoS 2 transistor delivering a record high ON-current of 0.83 mA/μm at 300 K and 1.48 mA/μm at 20 K, which compares well with that of silicon devices. Our study, for the first time, demonstrates that the 2DSC transistors can offer comparable performance to the 2017 target for silicon transistors in International Technology Roadmap for Semiconductors (ITRS), marking an important milestone in 2DSC electronics.

Phase transitions in methyl parben doped dipalmitoyl phosphatidylethanolamine vesicles

NASA Astrophysics Data System (ADS)

Panicker, Lata

2013-02-01

Influence of the preservative, methyl paraben (MPB), on the thermal properties of dipalmitoyl phosphatidylethanolamine (DPPE) vesicles was investigated using DSC. DSC measurement of the lipid acyl chain melting transition in DPPE membrane doped with MPB, showed MPB concentration dependant modifications in the membrane thermal properties. The interesting findings are: (1) the presence of parabens increases the membrane fluidity. (2) the MPB molecules seem to be present in the aqueous bilayer interfacial region intercalated between the neighboring lipid polar headgroup (3) high concentration of MPB favored formation of crystalline and glassy phases.

Synthesis of Amorphous Powders of Ni-Si and Co-Si Alloys by Mechanical Alloying

NASA Astrophysics Data System (ADS)

Omuro, Keisuke; Miura, Harumatsu

1991-05-01

Amorphous powders of the Ni-Si and Co-Si alloys are synthesized by mechanical alloying (MA) from crystalline elemental powders using a high energy ball mill. The alloying and amorphization process is examined by X-ray diffraction, differential scanning calorimetry (DSC), and scanning electron microscopy. For the Ni-Si alloy, it is confirmed that the crystallization temperature of the MA powder, measured by DSC, is in good agreement with that of the powder sample prepared by mechanical grinding from the cast alloy ingot products of the same composition.

Electrical properties of CZTS thin films

NASA Astrophysics Data System (ADS)

Rao, M. C.; Kumar, M. Seshu; Lakshmi, K.; Rao, K. Koteswara; Parimala, M. P. D.; Basha, S. K. Shahenoor

2018-05-01

CZTS (Cu2ZnSnS4) thin films have been coated on to FTO and MO glass substrates by single step electro deposition process. Different characterization techniques were performed on to the prepared samples such as DSC and Raman studies. The Phase transition and weight loss of the precursors can be measured by DSC analysis. Raman spectrum is used to identify the functional groups and chemical structure involved in the materials. Electrical measurements confirm the nature of the film and also depend on the charge concentration present in the samples.

Effectiveness of dye sensitised solar cell under low light condition using wide band dye

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

Sahmer, Ahmad Zahrin, E-mail: ahmadzsahmer@gmail.com; Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Zaine, Siti Nur Azella, E-mail: ct.azella@gmail.com

2015-07-22

Dye sensistised solar cell (DSC) based on nanocrystalline TiO{sub 2} has the potential to be used in indoor consumer power application. In realizing this, the DSC must be optimized to generate power under low lighting condition and under wider visible light range. The use of wide band dye N749 which has a wider spectrum sensitivity increases the photon conversion to electron between the visible light spectrums of 390nm to 700nm. This paper reports the study on the effectiveness of the dye solar cell with N749 dye under low light condition in generating usable power which can be used for indoormore » consumer application. The DSC was fabricated using fluorine doped tin oxide (FTO) glass with screen printing method and the deposited TiO{sub 2} film was sintered at 500°C. The TiO{sub 2} coated FTO glass was then soaked in the N749 dye, assembled into test cell, and tested under the standard test condition at irradiance of 1000 W/m{sup 2} with AM1.5 solar soaker. The use of the 43T mesh for the dual pass screen printing TiO{sub 2} paste gives a uniform TiO{sub 2} film layer of 16 µm. The low light condition was simulated using 1/3 filtered irradiance with the solar soaker. The fabricated DSC test cell with the N749 dye was found to have a higher efficiency of 6.491% under low light condition compared to the N719 dye. Under the standard test condition at 1 sun the N749 test cell efficiency is 4.55%. The increases in efficiency is attributed to the wider spectral capture of photon of the DSC with N749 dye. Furthermore, the use of N749 dye is more effective under low light condition as the V{sub OC} decrement is less significant compared to the latter.« less

Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

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

Zhu, Mingyao; Bzdusek, Karl; Brink, Carsten

2013-11-15

Purpose: Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE). Methods and Materials: CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independent institutions were autosegmented using SPICE and computational times were recorded. The number of structures autocontoured were 25 for the HN, 7 for the thorax, 3 for the liver, and 6 for the male pelvis regions. Using the clinical contours as reference, autocontours of 22 selected structures were quantitatively evaluated using Dice Similarity Coefficient (DSC) and Mean Slice-wisemore » Hausdorff Distance (MSHD). All 40 autocontours were evaluated by a radiation oncologist from the institution that treated the patients. Results: The mean computational times to autosegment all the structures using SPICE were 3.1 to 11.1 minutes per patient. For the HN region, the mean DSC was >0.70 for all evaluated structures, and the MSHD ranged from 3.2 to 10.0 mm. For the thorax region, the mean DSC was 0.95 for the lungs and 0.90 for the heart, and the MSHD ranged from 2.8 to 12.8 mm. For the liver region, the mean DSC was >0.92 for all structures, and the MSHD ranged from 5.2 to 15.9 mm. For the male pelvis region, the mean DSC was >0.76 for all structures, and the MSHD ranged from 4.8 to 10.5 mm. Out of the 40 autocontoured structures reviews by experts, 25 were scored useful as autocontoured or with minor edits for at least 90% of the patients and 33 were scored useful autocontoured or with minor edits for at least 80% of the patients. Conclusions: Compared with manual contouring, autosegmentation using SPICE for the HN, thorax, liver, and male pelvis regions is efficient and shows significant promise for clinical utility.« less

Brain Gliomas: Multicenter Standardized Assessment of Dynamic Contrast-enhanced and Dynamic Susceptibility Contrast MR Images.

PubMed

Anzalone, Nicoletta; Castellano, Antonella; Cadioli, Marcello; Conte, Gian Marco; Cuccarini, Valeria; Bizzi, Alberto; Grimaldi, Marco; Costa, Antonella; Grillea, Giovanni; Vitali, Paolo; Aquino, Domenico; Terreni, Maria Rosa; Torri, Valter; Erickson, Bradley J; Caulo, Massimo

2018-06-01

Purpose To evaluate the feasibility of a standardized protocol for acquisition and analysis of dynamic contrast material-enhanced (DCE) and dynamic susceptibility contrast (DSC) magnetic resonance (MR) imaging in a multicenter clinical setting and to verify its accuracy in predicting glioma grade according to the new World Health Organization 2016 classification. Materials and Methods The local research ethics committees of all centers approved the study, and informed consent was obtained from patients. One hundred patients with glioma were prospectively examined at 3.0 T in seven centers that performed the same preoperative MR imaging protocol, including DCE and DSC sequences. Two independent readers identified the perfusion hotspots on maps of volume transfer constant (K trans ), plasma (v p ) and extravascular-extracellular space (v e ) volumes, initial area under the concentration curve, and relative cerebral blood volume (rCBV). Differences in parameters between grades and molecular subtypes were assessed by using Kruskal-Wallis and Mann-Whitney U tests. Diagnostic accuracy was evaluated by using receiver operating characteristic curve analysis. Results The whole protocol was tolerated in all patients. Perfusion maps were successfully obtained in 94 patients. An excellent interreader reproducibility of DSC- and DCE-derived measures was found. Among DCE-derived parameters, v p and v e had the highest accuracy (are under the receiver operating characteristic curve [A z ] = 0.847 and 0.853) for glioma grading. DSC-derived rCBV had the highest accuracy (A z = 0.894), but the difference was not statistically significant (P > .05). Among lower-grade gliomas, a moderate increase in both v p and rCBV was evident in isocitrate dehydrogenase wild-type tumors, although this was not significant (P > .05). Conclusion A standardized multicenter acquisition and analysis protocol of DCE and DSC MR imaging is feasible and highly reproducible. Both techniques showed a

Pseudo-extravasation rate constant of dynamic susceptibility contrast-MRI determined from pharmacokinetic first principles.

PubMed

Li, Xin; Varallyay, Csanad G; Gahramanov, Seymur; Fu, Rongwei; Rooney, William D; Neuwelt, Edward A

2017-11-01

Dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) is widely used to obtain informative perfusion imaging biomarkers, such as the relative cerebral blood volume (rCBV). The related post-processing software packages for DSC-MRI are available from major MRI instrument manufacturers and third-party vendors. One unique aspect of DSC-MRI with low-molecular-weight gadolinium (Gd)-based contrast reagent (CR) is that CR molecules leak into the interstitium space and therefore confound the DSC signal detected. Several approaches to correct this leakage effect have been proposed throughout the years. Amongst the most popular is the Boxerman-Schmainda-Weisskoff (BSW) K 2 leakage correction approach, in which the K 2 pseudo-first-order rate constant quantifies the leakage. In this work, we propose a new method for the BSW leakage correction approach. Based on the pharmacokinetic interpretation of the data, the commonly adopted R 2 * expression accounting for contributions from both intravascular and extravasating CR components is transformed using a method mathematically similar to Gjedde-Patlak linearization. Then, the leakage rate constant (K L ) can be determined as the slope of the linear portion of a plot of the transformed data. Using the DSC data of high-molecular-weight (~750 kDa), iron-based, intravascular Ferumoxytol (FeO), the pharmacokinetic interpretation of the new paradigm is empirically validated. The primary objective of this work is to empirically demonstrate that a linear portion often exists in the graph of the transformed data. This linear portion provides a clear definition of the Gd CR pseudo-leakage rate constant, which equals the slope derived from the linear segment. A secondary objective is to demonstrate that transformed points from the initial transient period during the CR wash-in often deviate from the linear trend of the linearized graph. The inclusion of these points will have a negative impact on the accuracy of the leakage

SU-F-J-81: Evaluation of Automated Deformable Registration Between Planning Computed Tomography (CT) and Daily Cone Beam CT Images Over the Course of Prostate Cancer Radiotherapy

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

Matney, J; Hammers, J; Kaidar-Person, O

2016-06-15

Purpose: To compute daily dose delivered during radiotherapy, deformable registration needs to be relatively fast, automated, and accurate. The aim of this study was to evaluate the performance of commercial deformable registration software for deforming between two modalities: planning computed tomography (pCT) images acquired for treatment planning and cone beam (CB) CT images acquired prior to each fraction of prostate cancer radiotherapy. Methods: A workflow was designed using MIM Software™ that aligned and deformed pCT into daily CBCT images in two steps: (1) rigid shifts applied after daily CBCT imaging to align patient anatomy to the pCT and (2) normalizedmore » intensity-based deformable registration to account for interfractional anatomical variations. The physician-approved CTV and organ and risk (OAR) contours were deformed from the pCT to daily CBCT over the course of treatment. The same structures were delineated on each daily CBCT by a radiation oncologist. Dice similarity coefficient (DSC) mean and standard deviations were calculated to quantify the deformable registration quality for prostate, bladder, rectum and femoral heads. Results: To date, contour comparisons have been analyzed for 31 daily fractions of 2 of 10 of the cohort. Interim analysis shows that right and left femoral head contours demonstrate the highest agreement (DSC: 0.96±0.02) with physician contours. Additionally, deformed bladder (DSC: 0.81±0.09) and prostate (DSC: 0.80±0.07) have good agreement with physician-defined daily contours. Rectum contours have the highest variations (DSC: 0.66±0.10) between the deformed and physician-defined contours on daily CBCT imaging. Conclusion: For structures with relatively high contrast boundaries on CBCT, the MIM automated deformable registration provided accurate representations of the daily contours during treatment delivery. These findings will permit subsequent investigations to automate daily dose computation from CBCT. However

Roton Excitations and the Fluid-Solid Phase Transition in Superfluid 2D Yukawa Bosons

NASA Astrophysics Data System (ADS)

Molinelli, S.; Galli, D. E.; Reatto, L.; Motta, M.

2016-10-01

We compute several ground-state properties and the dynamical structure factor of a zero-temperature system of Bosons interacting with the 2D screened Coulomb (2D-SC) potential. We resort to the exact shadow path integral ground state (SPIGS) quantum Monte Carlo method to compute the imaginary-time correlation function of the model, and to the genetic algorithm via falsification of theories (GIFT) to retrieve the dynamical structure factor. We provide a detailed comparison of ground-state properties and collective excitations of 2D-SC and ^4He atoms. The roton energy of the 2D-SC system is an increasing function of density, and not a decreasing one as in ^4He. This result is in contrast with the view that the roton is the soft mode of the fluid-solid transition. We uncover a remarkable quasi-universality of backflow and of other properties when expressed in terms of the amount of short-range order as quantified by the height of the first peak of the static structure factor.

Moisture-Absorption and Water Dynamics in the Powder of Egg Albumen Peptide, Met-Pro-Asp-Ala-His-Leu.

PubMed

Yang, Shuailing; Liu, Xuye; Zhang, Mingdi; Lin, Songyi; Chen, Feng

2017-01-01

Moisture absorbed into the powder of Met-Pro-Asp-Ala-His-Leu (MPDAHL)-a novel egg albumen antioxidant peptide-profoundly affects its properties. In this study, we elucidated water dynamics in MPDAHL using DVS, DSC, and low-field 1 H NMR. Based on the DVS data, we found that MPDAHL sorption kinetics obey a parallel exponential model. DSC results indicated that both water and heating could change the microstructure of MPDAHL. The T 2 parameters of NMR reflected the different phases of moisture absorption revealed that there were 4 categories of water with different states or mobility in the MPDAHL during the moisture absorption process. The fastest fraction T 2b mainly dominated the hygroscopicity of MPDAHL and the absorbed water significantly changed the proton distribution and structure of MPDAHL. Thus, this study shows that DVS, DSC, and low-field 1 H NMR are effective methods for monitoring water mobility and distribution in synthetic peptides. It can be used to improve the quality assurance of functional peptides. © 2016 Institute of Food Technologists®.

Kinetics of phase transformation in glass forming systems

NASA Technical Reports Server (NTRS)

Ray, Chandra S.

1994-01-01

The objectives of this research were to (1) develop computer models for realistic simulations of nucleation and crystal growth in glasses, which would also have the flexibility to accomodate the different variables related to sample characteristics and experimental conditions, and (2) design and perform nucleation and crystallization experiments using calorimetric measurements, such as differential scanning calorimetry (DSC) and differential thermal analysis (DTA) to verify these models. The variables related to sample characteristics mentioned in (1) above include size of the glass particles, nucleating agents, and the relative concentration of the surface and internal nuclei. A change in any of these variables changes the mode of the transformation (crystallization) kinetics. A variation in experimental conditions includes isothermal and nonisothermal DSC/DTA measurements. This research would lead to develop improved, more realistic methods for analysis of the DSC/DTA peak profiles to determine the kinetic parameters for nucleation and crystal growth as well as to assess the relative merits and demerits of the thermoanalytical models presently used to study the phase transformation in glasses.

Examination of a Standardized Test for Evaluating the Degree of Cure of EVA Encapsulation (Presentation)

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

Miller, D.; Wohlgemuth, J.; Gu, X.

2013-11-01

The curing of cross-linkable encapsulation is a critical consideration for photovoltaic (PV) modules manufactured using a lamination process. Concerns related to ethylene-co-vinyl acetate (EVA) include the quality (e.g., expiration and uniformity) of the films or completion (duration) of the cross-linking of the EVA within a laminator. Because these issues are important to both EVA and module manufacturers, an international standard has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the degree of cure for EVA encapsulation. The present draft of themore » standard calls for the use of differential scanning calorimetry (DSC) as the rapid, enabling secondary (test) method. Both the residual enthalpy- and melt/freeze-DSC methods are identified. The DSC methods are calibrated against the gel content test, the primary (reference) method. Aspects of other established methods, including indentation and rotor cure metering, were considered by the group. Key details of the test procedure will be described.« less

Cocrystal screening of hydroxybenzamides with benzoic acid derivatives: a comparative study of thermal and solution-based methods.

PubMed

Manin, Alex N; Voronin, Alexander P; Drozd, Ksenia V; Manin, Nikolay G; Bauer-Brandl, Annette; Perlovich, German L

2014-12-18

The main problem occurring at the early stages of cocrystal search is the choice of an effective screening technique. Among the most popular techniques of obtaining cocrystals are crystallization from solution, crystallization from melt and solvent-drop grinding. This paper represents a comparative analysis of the following screening techniques: DSC cocrystal screening method, thermal microscopy and saturation temperature method. The efficiency of different techniques of cocrystal screening was checked in 18 systems. Benzamide and benzoic acid derivatives were chosen as model systems due to their ability to form acid-amide supramolecular heterosynthon. The screening has confirmed the formation of 6 new cocrystals. The screening by the saturation temperature method has the highest screen-out rate but the smallest range of application. DSC screening has a satisfactory accuracy and allows screening over a short time. Thermal microscopy is most efficient as an additional technique used to interpret ambiguous DSC screening results. The study also included an analysis of the influence of solvent type and component solubility on cocrystal formation. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of New Cocrystal Systems with Stoichiometric Diversity of Salicylic Acid Using Thermal Methods.

PubMed

Zhou, Zhengzheng; Chan, Hok Man; Sung, Herman H-Y; Tong, Henry H Y; Zheng, Ying

2016-04-01

The purpose of this work was to develop thermal methods to identify cocrystal systems with stoichiometric diversity. Differential scanning calorimetry (DSC) and hot stage microscopy (HSM) have been applied to study the stoichiometric diversity phenomenon on cocrystal systems of the model compound salicylic acid (SA) with different coformers (CCFs). The DSC method was particularly useful in the identification of cocrystal re-crystallization, especially to improve the temperature resolution using a slower heating rate. HSM was implemented as a complementary protocol to confirm the DSC results. The crystal structures were elucidated by single-crystal X-ray diffraction (SXRD). Two new cocrystal systems consisting of salicylic acid-benzamide (SA-BZD, 1:1, 1:2) and salicylic acid-isonicotinamide (SA-ISN, 1:1, 2:1) have been identified in the present work. The chemical structures of the newly discovered cocrystals SA-BZD (1:2) and SA-ISN (2:1) have been elucidated using X-ray single crystal and powder diffraction methods. The developed thermal methods could rapidly identify cocrystal systems with stoichiometric diversity, with the potential to discover new pharmaceutical cocrystals in the future.

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

Miller, D. C.; Gu, X.; Haldenman, S.

The curing of cross-linkable encapsulation is a critical consideration for photovoltaic (PV) modules manufactured using a lamination process. Concerns related to ethylene-co-vinyl acetate (EVA) include the quality (e.g., expiration and uniformity) of the films or completion (duration) of the cross-linking of the EVA within a laminator. Because these issues are important to both EVA and module manufacturers, an international standard has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the degree of cure for EVA encapsulation. The present draft of themore » standard calls for the use of differential scanning calorimetry (DSC) as the rapid, enabling secondary (test) method. Both the residual enthalpy- and melt/freeze-DSC methods are identified. The DSC methods are calibrated against the gel content test, the primary (reference) method. Aspects of other established methods, including indentation and rotor cure metering, were considered by the group. Key details of the test procedure will be described.« less

A dye-sensitized photoelectrochemical tandem cell for light driven hydrogen production from water

DOE PAGES

Sherman, Benjamin D.; Sheridan, Matthew V.; Wee, Kyung -Ryang; ...

2016-12-02

Here, tandem junction photoelectrochemical water-splitting devices, whereby two light absorbing electrodes targeting separate portions of the solar spectrum generate the voltage required to convert water to oxygen and hydrogen, enable much higher possible efficiencies than single absorber systems. We report here on the development of a tandem system consisting of a dye-sensitized photoelectrochemical cell (DSPEC) wired in series with a dye-sensitized solar cell (DSC). The DSPEC photoanode incorporates a tris(bipyridine)ruthenium(II)-type chromophore and molecular ruthenium based water oxidation catalyst. The DSPEC was tested with two more-red absorbing DSC variations, one utilizing N719 dye with an I 3 –/I – redox mediatormore » solution and the other D35 dye with a tris(bipyridine)cobalt ([Co(bpy) 3] 3+/2+) based mediator. The tandem configuration consisting of the DSPEC and D35/[Co(bpy) 3] 3+/2+ based DSC gave the best overall performance and demonstrated the production of H 2 from H 2O with the only energy input from simulated solar illumination.« less

Fatigue and mechanical properties of nickel-titanium endodontic instruments.

PubMed

Kuhn, Grégoire; Jordan, Laurence

2002-10-01

Shape memory alloys are increasingly used in superelastic conditions under complex cyclic deformation situations. In these applications, it is very difficult to predict the service life based on the theoretical law. In the present work, fatigue properties of NiTi engine-driven rotary files have been characterized by using differential scanning calorimetry (DSC) and mechanical testing (bending). The DSC technique was used to measure precise transformation. The degree of deformation by bending was studied with combined DSC and mechanical property measurements. In these cold-worked files, the high dislocation density influences the reorientation processes and the crack growth. Some thermal treatments are involved in promoting some changes in the mechanical properties and transformation characteristics. Annealing around 400 degrees C shows good results; the recovery allows a compromise between an adequate density for the R-Phase germination and a low density to limit the brittleness of these instruments. In clinical usage, it is important to consider different canal shapes. It could be proposed that only few cycles of use is safe for very curved canals but to follow the manufacturer's advise for straight canals.

Microstructural and thermal study of Al-Si-Mg/melon shell ash particulate composite

NASA Astrophysics Data System (ADS)

Abdulwahab, M.; Umaru, O. B.; Bawa, M. A.; Jibo, H. A.

The microstructural study via scanning electron microscope (SEM) and thermal study via differential scanning calorimetric (DSC) study of Al-7%Si-0.3Mg/melon shell ash particulate composite has been carried out. The melon shell ash was used in the production of MMC ranging from 5% to 20% at interval of 5% addition using stir casting method. The melon shell ash was characterized using X-ray fluorescent (XRF) that reveal the presence of CaO, SiO2, Al2O3, MgO, and TiO2 as major compounds. The composite was machined and subjected to heat treatment. Microstructural analyses of the composite produced were done using scanning electron microscope (SEM). The microstructure obtained reveals a dark ceramic (reinforcer) and white metallic phase. Equally, the 5 wt% DSC result gives better thermal conductivity than other proportions (10 wt%, 15 wt%, and 20 wt%). These results showed that an improved property of Al-Si-Mg alloy was achieved using melon shell ash particles as reinforcement up to a maximum of 20 wt% for microstructural and 5% wt DSC respectively.

Explosives remain preferred methods for platform abandonment

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

Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.

1996-05-06

Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp`s Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they requiredmore » that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains.« less

Respiration in neonate sea turtles.

PubMed

Price, Edwin R; Paladino, Frank V; Strohl, Kingman P; Santidrián T, Pilar; Klann, Kenneth; Spotila, James R

2007-03-01

The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings' response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ventilation characteristics that are similar to those of adults: a single breath followed by a long respiratory pause, slow frequency, and high metabolic rate. With hypercapnic challenge, both species responded primarily by elevating respiratory frequency via a decrease in the non-ventilatory period. Leatherback resting tidal volume increased with age but otherwise, neither species' resting respiratory pattern nor response to gas challenge changed significantly over the first few days after hatching. At the time of nest emergence, sea turtles have achieved a respiratory pattern that is similar to that of actively diving adults.

Quantitative analysis of herpes virus sequences from normal tissue and fibropapillomas of marine turtles with real-time PCR

USGS Publications Warehouse

Quackenbush, S.L.; Casey, R.N.; Murcek, R.J.; Paul, T.A.; Work, Thierry M.; Limpus, C.J.; Chaves, A.; duToit, L.; Perez, J.V.; Aguirre, A.A.; Spraker, T.R.; Horrocks, J.A.; Vermeer, L.A.; Balazs, G.S.; Casey, J.W.

2001-01-01

Quantitative real-time PCR has been used to measure fibropapilloma-associated turtle herpesvirus (FPTHV) pol DNA loads in fibropapillomas, fibromas, and uninvolved tissues of green, loggerhead, and olive ridley turtles from Hawaii, Florida, Costa Rica, Australia, Mexico, and the West Indies. The viral DNA loads from tumors obtained from terminal animals were relatively homogenous (range 2a??20 copies/cell), whereas DNA copy numbers from biopsied tumors and skin of otherwise healthy turtles displayed a wide variation (range 0.001a??170 copies/cell) and may reflect the stage of tumor development. FPTHV DNA loads in tumors were 2.5a??4.5 logs higher than in uninvolved skin from the same animal regardless of geographic location, further implying a role for FPTHV in the etiology of fibropapillomatosis. Although FPTHV pol sequences amplified from tumors are highly related to each other, single signature amino acid substitutions distinguish the Australia/Hawaii, Mexico/Costa Rica, and Florida/Caribbean groups.

Voluntary Enhancement of Neural Signatures of Affiliative Emotion Using fMRI Neurofeedback

PubMed Central

Moll, Jorge; Weingartner, Julie H.; Bado, Patricia; Basilio, Rodrigo; Sato, João R.; Melo, Bruno R.; Bramati, Ivanei E.; de Oliveira-Souza, Ricardo; Zahn, Roland

2014-01-01

In Ridley Scott’s film “Blade Runner”, empathy-detection devices are employed to measure affiliative emotions. Despite recent neurocomputational advances, it is unknown whether brain signatures of affiliative emotions, such as tenderness/affection, can be decoded and voluntarily modulated. Here, we employed multivariate voxel pattern analysis and real-time fMRI to address this question. We found that participants were able to use visual feedback based on decoded fMRI patterns as a neurofeedback signal to increase brain activation characteristic of tenderness/affection relative to pride, an equally complex control emotion. Such improvement was not observed in a control group performing the same fMRI task without neurofeedback. Furthermore, the neurofeedback-driven enhancement of tenderness/affection-related distributed patterns was associated with local fMRI responses in the septohypothalamic area and frontopolar cortex, regions previously implicated in affiliative emotion. This demonstrates that humans can voluntarily enhance brain signatures of tenderness/affection, unlocking new possibilities for promoting prosocial emotions and countering antisocial behavior. PMID:24847819

KSC-2014-2853

NASA Image and Video Library

2014-06-04

CAPE CANAVERAL, Fla. -- Slow and steady wins the race for this gopher tortoise, ambling along the Launch Pad 39B beach road on NASA's Kennedy Space Center in Florida. Gopher tortoises are dry-land turtles that live in scrub, dry hammock, pine flatwood, coastal grassland and dune habitats. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. Currently, gopher tortoises are protected in some states by federal law under the Endangered Species Act ESA. The refuge provides a habitat for 14 species federally listed as threatened or endangered, including the leatherback, green, Kemps Ridley, loggerhead and Atlantic hawksbill turtles. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. For more information on the gopher tortoise, visit http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html. Photo credit: NASA/Daniel Casper

KSC-2014-2851

NASA Image and Video Library

2014-06-04

CAPE CANAVERAL, Fla. -- Why did the gopher tortoise cross the road? To get to the other side of the Launch Pad 39B beach road on NASA's Kennedy Space Center in Florida, of course. Gopher tortoises are dry-land turtles that live in scrub, dry hammock, pine flatwood, coastal grassland and dune habitats. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. Currently, gopher tortoises are protected in some states by federal law under the Endangered Species Act ESA. The refuge provides a habitat for 14 species federally listed as threatened or endangered, including the leatherback, green, Kemps Ridley, loggerhead and Atlantic hawksbill turtles. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. For more information on the gopher tortoise, visit http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html. Photo credit: NASA/Daniel Casper

Pegasus XL CYGNSS Mission Science Briefing

NASA Image and Video Library

2016-12-10

In the Kennedy Space Center’s Press Site auditorium, NASA and industry leaders speak to members of the media during a mission science briefing for the agency’s Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. From left are: Sean Potter of NASA Communications; Dr. Chris Ruf, CYGNSS principal investigator, Department of Climate and Space Sciences and Engineering at the University of Michigan; Aaron Ridley, CYGNSS constellation scientist in the Climate and Space Department at the University of Michigan in Ann Arbor, Michigan; and Mary Morris, doctoral student in the Department of Climate and Space Sciences and Engineering at the University of Michigan. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data will help scientists probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a crucial role in the beginning and intensification of hurricanes.

Pegasus XL CYGNSS Mission Science Briefing

NASA Image and Video Library

2016-12-10

In the Kennedy Space Center’s Press Site auditorium, NASA and industry leaders speak to members of the media during a mission science briefing for the agency’s Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. From left are: Dr. Chris Ruf, CYGNSS principal investigator, Department of Climate and Space Sciences and Engineering at the University of Michigan; Aaron Ridley, CYGNSS constellation scientist in the Climate and Space Department at the University of Michigan in Ann Arbor, Michigan; and Mary Morris, doctoral student in the Department of Climate and Space Sciences and Engineering at the University of Michigan. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data will help scientists probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a crucial role in the beginning and intensification of hurricanes.

DSC (Differential Scanning Calorimeter) Stability Test for Liquid Propellants: A Preliminary Report.

DTIC Science & Technology

1987-09-01

AL 35898 1 Commander Commander Naval Air Systems Command US Army Missile and Space ATTN: J. Ramnarace, Intelligence Center AIR-54111C ATTN: AMSMI-YDL...uSE. .3o BUSIN S RE L MAIL FIRST CLASS PERMIT NO 12062 WASHINGTON,OCI 0IRTPOSTAGE WILL BE PAID BY DEPARTMENT OF THE ARMY Director US Army Ballistic

TG-DSC method applied to drying characteristics of areca inflorescence during drying

NASA Astrophysics Data System (ADS)

Song, Fei; Wang, Hui; Huang, Yulin; Zhang, Yufeng; Chen, Weijun; Zhao, Songlin; Zhang, Ming

2017-10-01

In this study, suitability of eight drying models available in literature on defining drying characteristics of areca inflorescence has been examined by non-linear regression analysis using the Statistic Computer Program. The coefficient of determination ( R 2 ) and the reduced chi-square (χ2) are used as indicators to evaluate the best suitable model. According to the results, the Verma et al. model gave the best results for explaining the drying characteristics of areca inflorescence. The drying process could be divided into three periods: rising rate, constant rate and the falling rate period. Fick's second law can describe the moisture transport during the food drying process that takes place in the falling rate period. The values of effective diffusivity during the drying of areca inflorescence ranged from 2.756 × 10-7 to 6.257 × 10-7 m2/s and the activation energy was tested for 35.535 kJ/mol. The heat requirement of areca inflorescence at 40-60 °C was calculated from 50.57 to 60.50 kJ/kg during the drying process.

Differential scanning calorimetry study and computer modeling of β ⇒ α phase transformation in a Ti-6Al-4V alloy

NASA Astrophysics Data System (ADS)

Malinov, S.; Guo, Z.; Sha, W.; Wilson, A.

2001-04-01

The relationship between heat-treatment parameters and microstructure in titanium alloys has so far been mainly studied empirically, using characterization techniques such as microscopy. Calculation and modeling of the kinetics of phase transformation have not yet been widely used for these alloys. Differential scanning calorimetry (DSC) has been widely used for the study of a variety of phase transformations. There has been much work done on the calculation and modeling of the kinetics of phase transformations for different systems based on the results from DSC study. In the present work, the kinetics of the β ⇒ α transformation in a Ti-6Al-4V titanium alloy were studied using DSC, at continuous cooling conditions with constant cooling rates of 5 °C, 10 °C, 20 °C, 30 °C, 40 °C, and 50 °C/min. The results from calorimetry were then used to trace and model the transformation kinetics in continuous cooling conditions. Based on suitably interpreted DSC results, continuous cooling-transformation (CCT) diagrams were calculated with lines of isotransformed fraction. The kinetics of transformation were modeled using the Johnson-Mehl-Avrami (JMA) theory and by applying the “concept of additivity.” The JMA kinetic parameters were derived. Good agreement between the calculated and experimental transformed fractions is demonstrated. Using the derived kinetic parameters, the β ⇒ α transformation in a Ti-6Al-4V alloy can be described for any cooling path and condition. An interpretation of the results from the point of view of activation energy for nucleation is also presented.

Dynamic susceptibility contrast-enhanced perfusion MR imaging at 1.5 T predicts final infarct size in a rat stroke model.

PubMed

Chen, Feng; Suzuki, Yasuhiro; Nagai, Nobuo; Peeters, Ronald; Marchal, Guy; Ni, Yicheng

2005-01-30

The purpose of the present animal experiment was to determine whether source images from dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI) at a 1.5T MR scanner, performed early after photochemically induced thrombosis (PIT) of cerebral middle artery (MCA), is feasible to predict final cerebral infarct size in a rat stroke model. Fifteen rats were subjected to PIT of proximal MCA. T2 weighted imaging (T2WI), diffusion-weighted imaging (DWI), and contrast-enhanced PWI were obtained at 1 h and 24 h after MCA occlusion. The relative lesion size (RLS) was defined as lesion volume/brain volume x 100% and measured for MR images, and compared with the final RLS on the gold standard triphenyl tetrazolium chloride (TTC) staining at 24 h. One hour after MCA occlusion, the RLS with DSC-PWI was 24.9 +/- 6.3%, which was significantly larger than 17.6 +/- 4.8% with DWI (P < 0.01). At 24 h, the final RLS on TTC was 24.3 +/- 4.8%, which was comparable to 25.1 +/- 3.5%, 24.6 +/- 3.6% and 27.9 +/- 6.8% with T2WI, DWI and DSC-PWI respectively (P > 0.05). The fact that at 1 h after MCA occlusion only the displayed perfusion deficit was similar to the final infarct size on TTC (P > 0.05) suggests that early source images from DSC-PWI at 1.5T MR scanner is feasible to noninvasively predict the final infarct size in rat models of stroke.

Poster — Thur Eve — 59: Atlas Selection for Automated Segmentation of Pelvic CT for Prostate Radiotherapy

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

Mallawi, A; Farrell, T; Diamond, K

2014-08-15

Automated atlas-based segmentation has recently been evaluated for use in planning prostate cancer radiotherapy. In the typical approach, the essential step is the selection of an atlas from a database that best matches the target image. This work proposes an atlas selection strategy and evaluates its impact on the final segmentation accuracy. Prostate length (PL), right femoral head diameter (RFHD), and left femoral head diameter (LFHD) were measured in CT images of 20 patients. Each subject was then taken as the target image to which all remaining 19 images were affinely registered. For each pair of registered images, the overlapmore » between prostate and femoral head contours was quantified using the Dice Similarity Coefficient (DSC). Finally, we designed an atlas selection strategy that computed the ratio of PL (prostate segmentation), RFHD (right femur segmentation), and LFHD (left femur segmentation) between the target subject and each subject in the atlas database. Five atlas subjects yielding ratios nearest to one were then selected for further analysis. RFHD and LFHD were excellent parameters for atlas selection, achieving a mean femoral head DSC of 0.82 ± 0.06. PL had a moderate ability to select the most similar prostate, with a mean DSC of 0.63 ± 0.18. The DSC obtained with the proposed selection method were slightly lower than the maximums established using brute force, but this does not include potential improvements expected with deformable registration. Atlas selection based on PL for prostate and femoral diameter for femoral heads provides reasonable segmentation accuracy.« less

A new optically transparent silicon containing polyimide film

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

Kumar, D.; Gupta, A.D.

1995-12-31

A new optically transparent, heat-resistant, flexible silicon containing polyimide (PI)(SIDA-BAPB) film has been developed. It was characterized by UV-Visible, FT-IR, differential scanning calorimetery (DSC), thermomechanical analysis (TMA) and thermogravimetric (TGA) analysis. The developed film showed high optical transparency in the 350-600 nm range of electromagnetic spectrum. The DSC analysis of the film showed glass transition temperature (T{sub g}) at 200{degrees}C. The dynamic thermogravimetric analysis (TGA) demonstrated its polymer decomposition temperature at 425{degrees}C. The char yield of the amorphous film in nitrogen at 800{degrees}C was 61%.

Calorimetric analysis of fungal degraded wood

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

Blankenhorn, P.R.; Baldwin, R.C.; Merrill, W. Jr.

1980-01-01

Endothermic transition and gross heat of combustion of aspenwood subjected to degradation by Lenzites trabea and Polyporus versicolor were determined by using differential scanning calorimetry (DSC) and an adiabatic O bomb. Endothermic peak areas of undegraded and fungi-degraded wood differed from each other at all levels of weight loss. The regression analysis of the DSC data vs. weight loss revealed a significant relations, although not highly correlated, for P. versicolor-degraded specimens and a nonsignificant relation for L. trabea-degraded specimens; weight loss and gross heat of combustion values of degraded specimens were significantly correlated.

Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis.

PubMed

Yang, Dezhi; Wang, Fengfeng; Zhang, Li; Gong, Ningbo; Lv, Yang

2015-05-01

This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.

Crystal Growth of Undoped and Doped ZnSe

NASA Technical Reports Server (NTRS)

Davis, Swanson L.; Chen, K.-T.; George, M. A.; Shi, D. T.; Collins, W. E.; Burger, Arnold

1997-01-01

The surface morphology of freshly cleaved ZnSe single crystal grown by the physical vapor transport (PVT) method was investigated by Atomic Force Microscopy (AFM) and the results were correlated with Differential Scanning Calorimetry (DSC) data. Selenium precipitates have been revealed in undoped doped ZnSe crystals having a size of about 50 nm. A transition temperature around 221 C in the DSC measurements is interpreted as the eutectic temperature of Se-saturated ZnSe. The AFM images of doped ZnSe also show that possible Cr clusters are uniformly distributed and they have an estimated size of about 6 nm.

Miscibility and Morphology of Poly(lactic ACID)/POLY(Β-HYDROXYBUTYRATE) Blends

NASA Astrophysics Data System (ADS)

Tri Phuong, Nguyen; Guinault, Alain; Sollogoub, Cyrille

2011-01-01

The miscibility and morphology of poly(lactic)acid (PLA)/polyβ-hydroxybutyrate (PHB) prepared by melt blending method were investigated by Fourier transform infrared (FTIR), Differential scanning calorimetry (DSC), melt rheology and scanning electron microscopy (SEM) observations. FTIR and DSC methods present some limits to examine the miscibility state of PLA/PHB blends. This drawback can be overcome with the Cole-Cole method by observing the η" = f(η') curves to confirm the miscibility of semicrystalline PLA/ semicrystalline PHB blends. MEB micrographs of fractured surface of blends were also used to investigate the miscibility of these blends.

Study of tellurium precipitates in CdTe crystals

NASA Technical Reports Server (NTRS)

Jayatirtha, H. N.; Henderson, D. O.; Burger, A.; Volz, M. P.

1993-01-01

The effect of tellurium precipitates was studied in medium resistivity (10 exp 3-10 exp 6 ohm cm) undoped and Cl-doped CdTe using differential scanning calorimetry (DSC) and mid-infrared spectroscopy and the results were correlated with near-infrared microscopy photographs. When present in a significant quantity (about 0.25 wt pct), we show that Te precipitates are detectable using DSC measurements. In the mid-infrared, the contribution of the absorption by free-carriers is negligible, and therefore, the effect of the Te precipitates in these crystals can be considered uncoupled from the effects of Cd vacancies.

Gulf Coast vulnerability assessment: Mangrove, tidal emergent marsh, barrier islands and oyster reef

USGS Publications Warehouse

Watson, Amanda; Reece, Joshua; Tirpak, Blair; Edwards, Cynthia Kallio; Geselbracht, Laura; Woodrey, Mark; LaPeyre, Megan K.; Dalyander, Patricia (Soupy)

2017-01-01

Climate, sea level rise, and urbanization are undergoing unprecedented levels of combined change and are expected to have large effects on natural resources—particularly along the Gulf of Mexico coastline (Gulf Coast). Management decisions to address these effects (i.e., adaptation) require an understanding of the relative vulnerability of various resources to these stressors. To meet this need, the four Landscape Conservation Cooperatives along the Gulf partnered with the Gulf of Mexico Alliance to conduct this Gulf Coast Vulnerability Assessment (GCVA). Vulnerability in this context incorporates exposure and sensitivity to threats (potential impact), coupled with the adaptive capacity to mitigate those threats. Potential impact and adaptive capacity reflect natural history features of target species and ecosystems. The GCVA used an expert opinion approach to qualitatively assess the vulnerability of four ecosystems: mangrove, oyster reef, tidal emergent marsh, and barrier islands, and a suite of wildlife species that depend on them. More than 50 individuals participated in the completion of the GCVA, facilitated via Ecosystem and Species Expert Teams. Of the species assessed, Kemp’s ridley sea turtle was identified as the most vulnerable species across the Gulf Coast. Experts identified the main threats as loss of nesting habitat to sea level rise, erosion, and urbanization. Kemp’s ridley also had an overall low adaptive capacity score due to their low genetic diversity, and higher nest site fidelity as compared to other assessed species. Tidal emergent marsh was the most vulnerable ecosystem, due in part to sea level rise and erosion. In general, avian species were more vulnerable than fish because of nesting habitat loss to sea level rise, erosion, and potential increases in storm surge. Assessors commonly indicated a lack of information regarding impacts due to projected changes in the disturbance regime, biotic interactions, and synergistic effects in

The Gulf Coast Vulnerability Assessment: Mangrove, Tidal Emergent Marsh, Barrier Islands, and Oyster Reef

USGS Publications Warehouse

Watson, Amanda; Reece, Joshua S.; Tirpak, Blair; Edwards, Cynthia Kallio; Geselbracht, Laura; Woodrey, Mark; LaPeyre, Megan K.; Dalyander, P. Soupy

2015-01-01

Climate, sea level rise, and urbanization are undergoing unprecedented levels of combined change and are expected to have large effects on natural resources—particularly along the Gulf of Mexico coastline (Gulf Coast). Management decisions to address these effects (i.e., adaptation) require an understanding of the relative vulnerability of various resources to these stressors. To meet this need, the four Landscape Conservation Cooperatives along the Gulf partnered with the Gulf of Mexico Alliance to conduct this Gulf Coast Vulnerability Assessment (GCVA). Vulnerability in this context incorporates the aspects of exposure and sensitivity to threats, coupled with the adaptive capacity to mitigate those threats. Potential impact and adaptive capacity reflect natural history features of target species and ecosystems. The GCVA used an expert opinion approach to qualitatively assess the vulnerability of four ecosystems: mangrove, oyster reef, tidal emergent marsh, and barrier islands, and a suite of wildlife species that depend on them. More than 50 individuals participated in the completion of the GCVA, facilitated via Ecosystem and Species Expert Teams. Of the species assessed, Kemp’s ridley sea turtle was identified as the most vulnerable species across the Gulf Coast. Experts identified the main threats as loss of nesting habitat to sea level rise, erosion, and urbanization. Kemp’s ridley also had an overall low adaptive capacity score due to their low genetic diversity, and higher nest site fidelity as compared to other assessed species. Tidal emergent marsh was the most vulnerable ecosystem, due in part to sea level rise and erosion. In general, avian species were more vulnerable than fish because of nesting habitat loss to sea level rise, erosion, and potential increases in storm surge. Assessors commonly indicated a lack of information regarding impacts due to projected changes in the disturbance regime, biotic interactions, and synergistic effects in both

Quantification of normal cerebral oxygen extraction and oxygen metabolism by phase-based MRI susceptometry: evaluation of repeatability using two different imaging protocols.

PubMed

Kämpe, Robin; Lind, Emelie; Ståhlberg, Freddy; van Westen, Danielle; Knutsson, Linda; Wirestam, Ronnie

2017-03-01

Global oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO 2 ) were quantified in a test-retest study. Cerebral blood flow (CBF) data, required for CMRO 2 estimation, were obtained using dynamic susceptibility contrast MRI (DSC-MRI). OEF and CMRO 2 were quantified using two separate data sets, that is, conventional high-resolution (HR) gradient echo (GRE) phase maps as well as echo planar imaging (EPI) phase maps taken from the baseline (precontrast) part of the DSC-MRI time series. The EPI phase data were included to elucidate whether an extra HR-GRE scan is needed to obtain information about OEF and CMRO 2 , or if this information can be extracted from the DSC-MRI experiment only. Twenty healthy volunteers were scanned using 3 T MRI on two occasions. Oxygen saturation levels were obtained from phase data measured in the great cerebral vein of Galen, based on HR-GRE as well as EPI phase maps. In combination with DSC-MRI CBF, this allowed for calculation of OEF and CMRO 2 . High-resolution-gradient echo- and EPI-based phase images resulted in similar OEF spread and repeatability, with coefficients of variation/intraclass correlation coefficients of 0·26/0·95 and 0·23/0·81, respectively. Absolute OEF values (HR-GRE: 0·40 ± 0·11, EPI: 0·35 ± 0·08) were consistent with literature data. CMRO 2 showed similar repeatability, somewhat increased spread and reasonable absolute values (HR-GRE: 3·23 ± 1·26 ml O 2 /100 g min -1 , EPI: 2·79 ± 0·89 ml O 2 /100 g min -1 ). In general, the results obtained by HR-GRE and EPI showed comparable characteristics. The EPI methodology could potentially be improved using a slightly modified DSC-MRI protocol (e.g. with regard to spatial resolution and slice gap). © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Thermal Properties of Starch From New Corn Lines as Impacted by Environment and During Line Development

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

Lenihan, Elizabeth M

The objectives of this research were to further characterize exotic by adapted corn inbreds by studying the impact of environment on their starch thermal properties, and investigating the development of starch thermal properties during kernel maturation by using differential scanning calorimetry (DSC). A method to expedite identification of unusual starch thermal traits was investigated by examining five corn kernels at a time, instead of one kernel, which the previous screening methods used. Corn lines with known thermal functions were blended with background starch (control) in ratios of unique starch to control starch, and analyzed by using DSC. Control starch wasmore » representative of typical corn starch. The values for each ratio within a mutant type were unique (α < 0.01) for most DSC measurements. These results supported the five-kernel method for rapidly screening large amounts of corn germplasm to identify unusual starch traits. The effects of 5 growing locations on starch thermal properties from exotic by adapted corn and Corn Belt lines were studied using DSC. The warmest location, Missouri, generally produced starch with greater gelatinization onset temperature (T oG), narrower range of gelatinization (R G), and greater enthalpy of gelatinization (ΔH G). The coolest location, Illinois, generally resulted in starch with lower T oG, wider R G, and lower ΔH G. Starch from the Ames 1 farm had thermal properties similar to those of Illinois, whereas starch from the Ames 2 farm had thermal properties similar to those of Missouri. The temperature at Ames 2 may have been warmer since it was located near a river; however, soil type and quality also were different. Final corn starch structure and function change during development and maturity. Thus, the changes in starch thermal properties during 5 stages of endosperm development from exotic by adapted corn and Corn Belt lines at two locations were studied by using DSC. The T oG tended to decrease during

Coupling distributed stormwater collection and managed aquifer recharge: Field application and implications.

PubMed

Beganskas, S; Fisher, A T

2017-09-15

Groundwater is increasingly important for satisfying California's growing fresh water demand. Strategies like managed aquifer recharge (MAR) can improve groundwater supplies, mitigating the negative consequences of persistent groundwater overdraft. Distributed stormwater collection (DSC)-MAR projects collect and infiltrate excess hillslope runoff before it reaches a stream, focusing on 40-400 ha drainage areas (100-1000 ac). We present results from six years of DSC-MAR operation-including high resolution analyses of precipitation, runoff generation, infiltration, and sediment transport-and discuss their implications for regional resource management. This project generated significant water supply benefit over six years, including an extended regional drought, collecting and infiltrating 5.3 × 10 5  m 3 (426 ac-ft). Runoff generation was highly sensitive to sub-daily storm frequency, duration, and intensity, and a single intense storm often accounted for a large fraction of annual runoff. Observed infiltration rates varied widely in space and time. The basin-average infiltration rate during storms was 1-3 m/d, with point-specific rates up to 8 m/d. Despite efforts to limit sediment load, 8.2 × 10 5  kg of fine-grained sediment accumulated in the infiltration basin over three years, likely reducing soil infiltration capacity. Periodic removal of accumulated material, better source control, and/or improved sediment detention could mitigate this effect in the future. Regional soil analyses can maximize DSC-MAR benefits by identifying high-infiltration capacity features and characterizing upland sediment sources. A regional network of DSC-MAR projects could increase groundwater supplies while contributing to improved groundwater quality, flood mitigation, and stakeholder engagement. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Dan, K.; Roy, M.; Datta, A.

The present manuscript describes the role of entropic and enthalpic forces mediated by organic non-polar (hexane) and polar (methanol) solvents on the bulk and microscopic phase transition of a well known nematic liquid crystalline material MBBA (N-(4-methoxybenzylidene)-4-butylaniline) through Differential Scanning calorimetry (DSC), UV-Visible (UV–Vis), and Fourier Transform Infrared (FTIR) spectroscopy. DSC study indicates continuous linear decreases in both nematic-isotropic (N-I) phase transition temperature and enthalpy of MBBA in presence of hexane while both these parameters show a saturation after an initial decay in methanol. These distinct transitional behaviours were explained in terms of the “depletion force” model for entropic screeningmore » in hexane and “screening-self-screening” model for methanol. Heating rate dependent DSC studies find that non-Arrhenius behaviour, characteristic of pristine MBBA and a manifestation of non-equilibrium nature [Dan et al., J. Chem. Phys. 143, 094501 (2015)], is preserved in presence of entropic screening in the hexane solution, while it changes to Arrhenius behaviour (signifying equilibrium behaviour) in presence of enthalpic screening in methanol solution. FTIR spectra show similar dependence on the solvent induced screening in the intensities of the imine (—C = N) stretch and the out-of-plane distortion vibrations of the benzene rings of MBBA with hexane and methanol as in DSC, further establishing our entropic and enthalpic screening models. UV–Vis spectra of the electronic transitions in MBBA as a function of temperature also exhibit different dependences of intensities on the solvent induced screening, and an exponential decrease is observed in presence of hexane while methanol completely changes the nature of interaction to follow a linear dependence.« less

Chemokine CCL28 induces apoptosis of decidual stromal cells via binding CCR3/CCR10 in human spontaneous abortion.

PubMed

Sun, Chan; Zhang, Yuan-Yuan; Tang, Chuan-Ling; Wang, Song-Cun; Piao, Hai-Lan; Tao, Yu; Zhu, Rui; Du, Mei-Rong; Li, Da-Jin

2013-10-01

Spontaneous abortion is the most common complication of pregnancy. Immune activation and the subsequent inflammation-induced tissue injury are often observed at the maternal-fetal interface as the final pathological assault in recurrent spontaneous abortion. However, the precise mechanisms responsible for spontaneous abortion involving inflammation are not fully understood. Chemokine CCL28 and its receptors CCR3 and CCR10 are important regulators in inflammatory process. Here, we examined the expression of CCL28 and its receptors in decidual stromal cells (DSCs) by immunochemistry and flow cytometry (FCM), and compared their expression level in DSCs from normal pregnancy versus spontaneous abortion, and their relationship to inflammatory cytokines production by DSCs. We further analyzed regulation of the pro-inflammatory cytokines on CCL28 expression in DSCs by real-time polymerase chain reaction, In-cell Western and FCM. The effects of CCL28-CCR3/CCR10 interaction on DSC apoptosis was investigated by Annexin V staining and FCM analysis or DAPI staining and nuclear morphology. Higher levels of the inflammatory cytokines interleukin (IL)-1β, IL-17A and tumor necrosis factor-α, and increased CCR3/CCR10 expression were observed in DSCs from spontaneous abortion compared with normal pregnancy. Treatment with inflammatory cytokines differently affected CCL28 and CCR3/CCR10 expression in DSCs. Human recombinant CCL28 promoted DSC apoptosis, which was eliminated by pretreatment with neutralizing antibodies against CCR3/CCR10 and CCL28. However, CCL28 did not affect DSC growth. These results suggest that the inflammation-promoted up-regulation of CCL28 and its receptors interaction in DSCs is involved in human spontaneous abortion via inducing DSC apoptosis.

Assessment of degree of disorder (amorphicity) of lyophilized formulations of growth hormone using isothermal microcalorimetry.

PubMed

Mosharraf, Mitra

2004-05-01

When determining the degree of disorder of a lyophilized cake of a protein, it is important to use an appropriate analytical technique. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) are the most commonly used thermoanalytical techniques for characterizing freeze-dried protein formulations. Unfortunately, these methods are unable to detect solid-state disorder at levels < 10%. Also, interpretation of DSC results for freeze-dried protein formulations can be difficult, as a result of the more complex thermal events occurring with this technique. For example, proteins can inhibit the thermally induced recrystallization of the lyophilized cake, resulting in potential misinterpretation of DSC degree of disorder results. The aim of this investigation was to study the use of isothermal microcalorimetry (IMC) in the assessment of degree of solid-state disorder (amorphicity) of lyophilized formulations of proteins. For this purpose, two formulations of growth hormone were prepared by lyophilization. These formulations consisted of the same amounts of protein, mannitol, glycine, and phosphate buffer, but differed in the freeze-drying procedure. After lyophilization, the recrystallization of the samples was studied using IMC at 25 degrees C under different relative humidities (58-75%). The effect of available surface area was studied by determining the heat of recrystallization (Q) of the samples before and after disintegration of the cakes. The results showed that, in contrast to DSC, IMC allowed detection of the recrystallization event in the formulations. Although both formulations were completely disordered and indistinguishable according to XRPD method, IMC revealed that formulation B had a different solid-sate structure than formulation A. This difference was the result of differences in the freeze-drying parameters, demonstrating the importance of choosing appropriate analytical methodology.

Pretreatment Dynamic Susceptibility Contrast MRI Perfusion in Glioblastoma: Prediction of EGFR Gene Amplification.

PubMed

Gupta, A; Young, R J; Shah, A D; Schweitzer, A D; Graber, J J; Shi, W; Zhang, Z; Huse, J; Omuro, A M P

2015-06-01

Molecular and genetic testing is becoming increasingly relevant in GBM. We sought to determine whether dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) perfusion imaging could predict EGFR-defined subtypes of GBM. We retrospectively identified 106 consecutive glioblastoma (GBM) patients with known EGFR gene amplification, and a subset of 65 patients who also had known EGFRvIII gene mutation status. All patients underwent T2* DSC MRI perfusion. DSC perfusion maps and T2* signal intensity time curves were evaluated, and the following measures of tumor perfusion were recorded: (1) maximum relative cerebral blood volume (rCBV), (2) relative peak height (rPH), and (3) percent signal recovery (PSR). The imaging metrics were correlated to EGFR gene amplification and EGFRvIII mutation status using univariate analyses. EGFR amplification was present in 44 (41.5 %) subjects and absent in 62 (58.5 %). Among the 65 subjects who had undergone EGFRvIII mutation transcript analysis, 18 subjects (27.7 %) tested positive for the EGFRvIII mutation, whereas 47 (72.3 %) did not. Higher median rCBV (3.31 versus 2.62, p = 0.01) and lower PSR (0.70 versus 0.78, p = 0.03) were associated with high levels of EGFR amplification. Higher median rPH (3.68 versus 2.76, p = 0.03) was associated with EGFRvIII mutation. DSC MRI perfusion may have a role in identifying patients with EGFR gene amplification and EGFRvIII gene mutation status, potential targets for individualized treatment protocols. Our results raise the need for further investigation for imaging biomarkers of genetically unique GBM subtypes.

75 FR 25840 - Endangered and Threatened Species; Recovery Plans; Recovery Plan for the Kemp's Ridley Sea Turtle

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-10

...-1401, fax 301-713-0376) or Tom Shearer (ph. 361-994-9005, fax 361-994-8626). SUPPLEMENTARY INFORMATION... Therese Conant or Tom Shearer (see FOR FURTHER INFORMATION CONTACT). Background On March 16, 2010, we...

Physicochemical properties of liposomes as potential anticancer drugs carriers. Interaction of etoposide and cytarabine with the membrane: Spectroscopic studies

NASA Astrophysics Data System (ADS)

Pentak, Danuta

2014-03-01

The interactions between etoposide, cytarabine and 1,2-dihexadecanoyl-sn-glycerol-3-phosphocholine bilayers were studied using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). These techniques have proven to be a very powerful tool in studying the structure and dynamics of phospholipid bilayers. In particular, DSC can provide information on the phase transition temperature and cooperativity of the lipid molecules in the absence and presence of the drug. Vibrational spectroscopy is well suited to the study of drug-lipid interactions, since it allows for an investigation of the conformation of phospholipid molecules at different levels in lipid bilayers and follows structural changes that occur during the gel to liquid-crystalline phase transition. NMR supported the determination of the main phase transition temperatures (TC) of 1,2-dihexadecanoyl-sn-glycerol-3-phosphocholine (DPPC). The main phase transition temperature (TC) determined by 1H NMR is comparable with values obtained by DSC for all studied liposomes. The location of cytarabine and etoposide in liposomes was also determined by NMR. Atomic force microscopy (AFM) images, acquired immediately after sample deposition on a mica surface, revealed the spherical shape of lipid vesicles.

Study on Thermal Decomposition Characteristics of Ammonium Nitrate Emulsion Explosive in Different Scales

NASA Astrophysics Data System (ADS)

Wu, Qiujie; Tan, Liu; Xu, Sen; Liu, Dabin; Min, Li

2018-04-01

Numerous accidents of emulsion explosive (EE) are attributed to uncontrolled thermal decomposition of ammonium nitrate emulsion (ANE, the intermediate of EE) and EE in large scale. In order to study the thermal decomposition characteristics of ANE and EE in different scales, a large-scale test of modified vented pipe test (MVPT), and two laboratory-scale tests of differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC) were applied in the present study. The scale effect and water effect both play an important role in the thermal stability of ANE and EE. The measured decomposition temperatures of ANE and EE in MVPT are 146°C and 144°C, respectively, much lower than those in DSC and ARC. As the size of the same sample in DSC, ARC, and MVPT successively increases, the onset temperatures decrease. In the same test, the measured onset temperature value of ANE is higher than that of EE. The water composition of the sample stabilizes the sample. The large-scale test of MVPT can provide information for the real-life operations. The large-scale operations have more risks, and continuous overheating should be avoided.

A Resource for Discovering Specific and Universal Biomarkers for Distributed Stem Cells

PubMed Central

Noh, Minsoo; Smith, Janet L.; Huh, Yang Hoon; Sherley, James L.

2011-01-01

Specific and universal biomarkers for distributed stem cells (DSCs) have been elusive. A major barrier to discovery of such ideal DSC biomarkers is difficulty in obtaining DSCs in sufficient quantity and purity. To solve this problem, we used cell lines genetically engineered for conditional asymmetric self-renewal, the defining DSC property. In gene microarray analyses, we identified 85 genes whose expression is tightly asymmetric self-renewal associated (ASRA). The ASRA gene signature prescribed DSCs to undergo asymmetric self-renewal to a greater extent than committed progenitor cells, embryonic stem cells, or induced pluripotent stem cells. This delineation has several significant implications. These include: 1) providing experimental evidence that DSCs in vivo undergo asymmetric self-renewal as individual cells; 2) providing an explanation why earlier attempts to define a common gene expression signature for DSCs were unsuccessful; and 3) predicting that some ASRA proteins may be ideal biomarkers for DSCs. Indeed, two ASRA proteins, CXCR6 and BTG2, and two other related self-renewal pattern associated (SRPA) proteins identified in this gene resource, LGR5 and H2A.Z, display unique asymmetric patterns of expression that have a high potential for universal and specific DSC identification. PMID:21818293

Synthesis and interaction of sterol-uridine conjugate with DMPC liposomes studied by differential scanning calorimetry.

PubMed

Escobar, Jhon Fernando Berrío; Restrepo, Manuel Humberto Pastrana; Fernández, Diana Margarita Márquez; Martínez, Alejandro Martínez; Giordani, Cristiano; Castelli, Francesco; Sarpietro, Maria Grazia

2018-06-01

Differential scanning calorimetry (DSC) is a thermoanalytical technique which provides information on the interaction between drugs and models of cell membranes. Studies on the calorimetric behavior of hydrated phospholipids within liposomes are employed to shed light on the changes in the physico-chemical properties when interacting with drugs. In this report, new potential anti-cancer drugs such as uridine and uridine derivatives (acetonide and its succinate), 3β-5α,8α-endoperoxide-cholestan-6-en-3-ol (5,8-epidioxicholesterol) and conjugate (uridine acetonide-epidioxicholesterol succinate) have been synthesized. Steglich esterification method using coupling agents allowed to obtain the uridine acetonide-sterol conjugate. The study on the interaction between the drugs and dimiristoyl-phophatidilcholine (DMPC) liposomes has been conducted by the use of DSC. The analysis of the DSC curves indicated that the uridine and derivatives (acetonide and its succinate) present a very soft interaction with the DMPC liposomes, whereas the 5,8-epidioxicholesterol and the conjugate showed a strong effect on the thermotropic behavior. Our results suggested that the lipophilic character of uridine acetonide-sterol conjugate improves the affinity with the DMPC liposomes. Copyright © 2018 Elsevier B.V. All rights reserved.

In vitro deposition of hydroxyapatite on cortical bone collagen stimulated by deformation-induced piezoelectricity.

PubMed

Noris-Suárez, Karem; Lira-Olivares, Joaquin; Ferreira, Ana Marina; Feijoo, José Luis; Suárez, Nery; Hernández, Maria C; Barrios, Esteban

2007-03-01

In the present work, we have studied the effect of the piezoelectricity of elastically deformed cortical bone collagen on surface using a biomimetic approach. The mineralization process induced as a consequence of the piezoelectricity effect was evaluated using scanning electron microscopy (SEM), thermally stimulated depolarization current (TSDC), and differential scanning calorimetry (DSC). SEM micrographs showed that mineralization occurred predominantly over the compressed side of bone collagen, due to the effect of piezoelectricity, when the sample was immersed in the simulated body fluid (SBF) in a cell-free system. The TSDC method was used to examine the complex collagen dielectric response. The dielectric spectra of deformed and undeformed collagen samples with different hydration levels were compared and correlated with the mineralization process followed by SEM. The dielectric measurements showed that the mineralization induced significant changes in the dielectric spectra of the deformed sample. DSC and TSDC results demonstrated a reduction of the collagen glass transition as the mineralization process advanced. The combined use of SEM, TSDC, and DSC showed that, even without osteoblasts present, the piezoelectric dipoles produced by deformed collagen can produce the precipitation of hydroxyapatite by electrochemical means, without a catalytic converter as occurs in classical biomimetic deposition.

Thermoanalytical Investigation of Some Sulfone-Containing Drugs

PubMed Central

Salama, Nahla N.; El Ries, Mohammed A.; Toubar, Safaa; Abd El Hamid, Maha; Walash, Mohammed I.

2012-01-01

The thermal behavior of some sulfone-containing drugs, namely, dapsone (DDS), dimethylsulfone (MSM), and topiramate (TOP) in drug substances, and products were investigated using different thermal techniques. These include thermogravimetry (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). The thermogravimetric data allowed the determination of the kinetic parameters: activation energy (E a), frequency factor (A), and reaction order (n). The thermal degradation of dapsone and topiramate was followed a first-order kinetic behavior. The calculated data evidenced a zero-order kinetic for dimethylsulfone. The relative thermal stabilities of the studied drugs have been evaluated and follow the order DDS > TOP > MSM. The purity was determined using DSC for the studied compounds, in drug substances and products. The results were in agreement with the recommended pharmacopoeia and manufacturer methods. DSC curves obtained from the tablets suggest compatibility between the drugs, excipients and/or coformulated drugs. The fragmentation pathway of dapsone with mass spectrometry was taken as example, to correlate the thermal decomposition with the resulted MS-EI. The decomposition modes were investigated, and the possible fragmentation pathways were suggested by mass spectrometry. PMID:22792516

Thermoanalytical investigation of some sulfone-containing drugs.

PubMed

Salama, Nahla N; El Ries, Mohammed A; Toubar, Safaa; Abd El Hamid, Maha; Walash, Mohammed I

2012-01-01

The thermal behavior of some sulfone-containing drugs, namely, dapsone (DDS), dimethylsulfone (MSM), and topiramate (TOP) in drug substances, and products were investigated using different thermal techniques. These include thermogravimetry (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). The thermogravimetric data allowed the determination of the kinetic parameters: activation energy (E(a)), frequency factor (A), and reaction order (n). The thermal degradation of dapsone and topiramate was followed a first-order kinetic behavior. The calculated data evidenced a zero-order kinetic for dimethylsulfone. The relative thermal stabilities of the studied drugs have been evaluated and follow the order DDS > TOP > MSM. The purity was determined using DSC for the studied compounds, in drug substances and products. The results were in agreement with the recommended pharmacopoeia and manufacturer methods. DSC curves obtained from the tablets suggest compatibility between the drugs, excipients and/or coformulated drugs. The fragmentation pathway of dapsone with mass spectrometry was taken as example, to correlate the thermal decomposition with the resulted MS-EI. The decomposition modes were investigated, and the possible fragmentation pathways were suggested by mass spectrometry.

Thermal degradation and morphological studies on raw and reinforced polyacrylic rubbers

NASA Astrophysics Data System (ADS)

Sasikala, A.; Kala, A.

2017-05-01

Poly acrylate rubbers (ACM) of today are saturated copolymers of monomeric acrylic esters and reactive cure site monomers. ACM elastomer have also found use in vibration damping due to its excellent resilience. Other applications include textiles, adhesives, and coatings. Two state of Poly acrylic raw and reinforced Rubber are analyzed using FTIR spectroscopy, Optical Microscopy, DSC and TGA measurements. With the objective of determined the mechanical strength, Thermal analysis on TGA and DSC studies show that, the thermal degradation temperature Tg of the sample material is obtained and activation energy is also calaulated by Broido, Horowitz - Metzger, Piloyan-Novikova and Coats Redfern methods which are found.

Reversible phase transition in vanadium oxide films sputtered on metal substrates

NASA Astrophysics Data System (ADS)

Palai, Debajyoti; Carmel Mary Esther, A.; Porwal, Deeksha; Pradeepkumar, Maurya Sandeep; Raghavendra Kumar, D.; Bera, Parthasarathi; Sridhara, N.; Dey, Arjun

2016-11-01

Vanadium oxide films, deposited on aluminium (Al), titanium (Ti) and tantalum (Ta) metal substrates by pulsed RF magnetron sputtering at a working pressure of 1.5 x10-2 mbar at room temperature are found to display mixed crystalline vanadium oxide phases viz., VO2, V2O3, V2O5. The films have been characterized by field-emission scanning electron microscopy, X-ray diffraction, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy, and their thermo-optical and electrical properties have been investigated. Studies of the deposited films by DSC have revealed a reversible-phase transition found in the temperature range of 45-49 °C.

Disturbed State constitutive modeling of two Pleistocene tills

NASA Astrophysics Data System (ADS)

Sane, S. M.; Desai, C. S.; Jenson, J. W.; Contractor, D. N.; Carlson, A. E.; Clark, P. U.

2008-02-01

The Disturbed State Concept (DSC) provides a general approach for constitutive modeling of deforming materials. Here, we briefly explain the DSC and present the results of laboratory tests on two regionally significant North American tills, along with the results of a numerical simulation to predict the behavior of one of the tills in an idealized physical system. Laboratory shear tests showed that plastic strain starts almost from the beginning of loading, and that failure and resulting motion begin at a critical disturbance, when about 85% of the mass has reached the fully adjusted or critical state. Specimens of both tills exhibited distributed strain, deforming into barrel shapes without visible shear planes. DSC parameters obtained from shear and creep tests were validated by comparing model predictions against test data used to find the parameters, as well as against data from independent tests. The DSC parameters from one of the tills were applied in a finite-element simulation to predict gravity-induced motion for a 5000-m long, 100-m thick slab of ice coupled to an underlying 1.5-m thick layer of till set on a 4° incline, with pore-water pressure in the till at 90% of the load. The simulation predicted that in the middle segment of the till layer (i.e., from x=2000 to 3000 m) the induced (computed) shear stress, strain, and disturbance increase gradually with the applied shear stress. Induced shear stress peaks at ˜60 kPa. The critical disturbance, at which failure occurs, is observed after the peak shear stress, at an induced shear stress of ˜23 kPa and shear strain of ˜0.75 in the till. Calculated horizontal displacement over the height of the entire till section at the applied shear stress of 65 kPa is ˜4.5 m. We note that the numerical prediction of critical disturbance, when the displacement shows a sharp change in rate, compares very well with the occurrence of critical disturbance observed in the laboratory triaxial tests, when a sharp change

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

Paliwal, B; Asprey, W; Yan, Y

Purpose: In order to take advantage of the high resolution soft tissue imaging available in MR images, we investigated 3D images obtained with the low field 0.35 T MR in ViewRay to serve as an alternative to CT scans for radiotherapy treatment planning. In these images, normal and target structure delineation can be visualized. Assessment is based upon comparison with the CT images and the ability to produce comparable contours. Methods: Routine radiation oncology CT scans were acquired on five patients. Contours of brain, brainstem, esophagus, heart, lungs, spinal cord, and the external body were drawn. The same five patientsmore » were then scanned on the ViewRay TrueFISP-based imaging pulse sequence. The same organs were selected on the MR images and compared to those from the CT scan. Physical volume and the Dice Similarity Coefficient (DSC) were used to assess the contours from the two systems. Image quality stability was quantitatively ensured throughout the study following the recommendations of the ACR MR accreditation procedure. Results: The highest DSC of 0.985, 0.863, and 0.843 were observed for brain, lungs, and heart respectively. On the other hand, the brainstem, spinal cord, and esophagus had the lowest DSC. Volume agreement was most satisfied for the heart (within 5%) and the brain (within 2%). Contour volume for the brainstem and lung (a widely dynamic organ) varied the most (27% and 19%). Conclusion: The DSC and volume measurements suggest that the results obtained from ViewRay images are quantitatively consistent and comparable to those obtained from CT scans for the brain, heart, and lungs. MR images from ViewRay are well-suited for treatment planning and for adaptive MRI-guided radiotherapy. The physical data from 0.35 T MR imaging is consistent with our geometrical understanding of normal structures.« less

Application of histogram analysis for the evaluation of vascular permeability in glioma by the K2 parameter obtained with the dynamic susceptibility contrast method: Comparisons with Ktrans obtained with the dynamic contrast enhance method and cerebral blood volume.

PubMed

Taoka, Toshiaki; Kawai, Hisashi; Nakane, Toshiki; Hori, Saeka; Ochi, Tomoko; Miyasaka, Toshiteru; Sakamoto, Masahiko; Kichikawa, Kimihiko; Naganawa, Shinji

2016-09-01

The "K2" value is a factor that represents the vascular permeability of tumors and can be calculated from datasets obtained with the dynamic susceptibility contrast (DSC) method. The purpose of the current study was to correlate K2 with Ktrans, which is a well-established permeability parameter obtained with the dynamic contrast enhance (DCE) method, and determine the usefulness of K2 for glioma grading with histogram analysis. The subjects were 22 glioma patients (Grade II: 5, III: 6, IV: 11) who underwent DSC studies, including eight patients in which both DSC and DCE studies were performed on separate days within 10days. We performed histogram analysis of regions of interest of the tumors and acquired 20th percentile values for leakage-corrected cerebral blood volume (rCBV20%ile), K2 (K220%ile), and for patients who underwent a DCE study, Ktrans (Ktrans20%ile). We evaluated the correlation between K220%ile and Ktrans20%ile and the statistical difference between rCBV20%ile and K220%ile. We found a statistically significant correlation between K220%ile and Ktrans20%ile (r=0.717, p<0.05). rCBV20%ile showed a significant difference between Grades II and III and between Grades II and IV, whereas K220%ile showed a statistically significant (p<0.05) difference between Grades II and IV and between Grades III and IV. The K2 value calculated from the DSC dataset, which can be obtained with a short acquisition time, showed a correlation with Ktrans obtained with the DCE method and may be useful for glioma grading when analyzed with histogram analysis. Copyright © 2016 Elsevier Inc. All rights reserved.

A high-resolution, regional analysis of stormwater runoff for managed aquifer recharge site assessment

NASA Astrophysics Data System (ADS)

Young, K. S.; Fisher, A. T.; Beganskas, S.; Harmon, R. E.; Teo, E. K.; Weir, W. B.; Lozano, S.

2016-12-01

Distributed Stormwater Collection-Managed Aquifer Recharge (DSC-MAR) presents a cost-effective method of aquifer replenishment by collecting runoff and infiltrating it into underlying aquifers, but its successful implementation demands thorough knowledge of the distribution and availability of hillslope runoff. We applied a surface hydrology model to analyze the dynamics of hillslope runoff at high resolution (0.1 to 1.0 km2) across the 350 km2 San Lorenzo River Basin (SLRB) watershed, northern Santa Cruz County, CA. We used a 3 m digital elevation model to create a detailed model grid, which we parameterized with high-resolution geologic, hydrologic, and land use data. To analyze hillslope runoff under a range of precipitation regimes, we developed dry, normal, and wet climate scenarios from historic daily precipitation records (1981-2014). Simulation results show high spatial variability of hillslope runoff generation as a function of differences in precipitation and soil and land use conditions, and reveal a consistent increase in the spatial and temporal variability of runoff under wetter climate scenarios. Our results suggest that there may be opportunities to develop successful DSC-MAR projects that provide benefits during all climate scenarios. In the SLRB, our results indicate that annual hillslope runoff generation achieves a target minimum of 100 acre-ft, per 100 acres of drainage area, in approximately 15% of the region during dry climate scenarios and 60% of the region during wet climate scenarios. The high spatial and temporal resolution of our simulation output enables quantification of hillslope runoff at sub-watershed scales, commensurate with the spacing and operation of DSC-MAR. This study demonstrates a viable tool for screening of potential DSC-MAR project sites and assessing project performance under a range of climate and land use scenarios.

Modification and identification of a vector for making a large phage antibody library.

PubMed

Zhang, Guo-min; Chen, Yü-ping; Guan, Yuan-zhi; Wang, Yan; An, Yun-qing

2007-11-20

The large phage antibody library is used to obtain high-affinity human antibody, and the Loxp/cre site-specific recombination system is a potential method for constructing a large phage antibody library. In the present study, a phage antibody library vector pDF was reconstructed to construct diabody more quickly and conveniently without injury to homologous recombination and the expression function of the vector and thus to integrate construction of the large phage antibody library with the preparation of diabodies. scFv was obtained by overlap polymerase chain reaction (PCR) amplification with the newly designed VL and VH extension primers. loxp511 was flanked by VL and VH and the endonuclease ACC III encoding sequences were introduced on both sides of loxp511. scFv was cloned into the vector pDF to obtain the vector pDscFv. The vector expression function was identified and the feasibility of diabody preparation was evaluated. A large phage antibody library was constructed in pDscFv. Several antigens were used to screen the antibody library and the quality of the antibody library was evaluated. The phage antibody library expression vector pDscFv was successfully constructed and confirmed to express functional scFv. The large phage antibody library constructed using this vector was of high diversity. Screening of the library on 6 antigens confirmed the generation of specific antibodies to these antigens. Two antibodies were subjected to enzymatic digestion and were prepared into diabody with functional expression. The reconstructed vector pDscFv retains its recombination capability and expression function and can be used to construct large phage antibody libraries. It can be used as a convenient and quick method for preparing diabodies after simple enzymatic digestion, which facilitates clinical trials and application of antibody therapy.

Isothermal Fourier transform infrared microspectrosopic studies on the stability kinetics of solid-state intramolecular cyclization of aspartame sweetener.

PubMed

Cheng, Y D; Lin, S Y

2000-03-01

A novel Fourier transform infrared (FT-IR) microspectrophotometer equipped with differential scanning calorimetry (DSC) was used to investigate the kinetics of intramolecular cyclization of aspartame (APM) sweetener in the solid state under isothermal conditions. The thermal-dependent changes in the peak intensity of IR spectra at 1543, 1283, and 1259 cm(-1) were examined to explore the reaction. The results support that the intramolecular cyclization process in APM proceeded in three steps: the methoxyl group of ester was first thermolyzed to release methanol, then an acyl cation was attacked by the lone pair of electrons available on nitrogen by an S(N)1 pathway, and finally ring-closure occurred. The intramolecular cyclization of APM determined by this microscopic FT-IR/DSC system was found to follow zero-order kinetics after a brief induction period. The bond cleavage energy (259.38 kJ/mol) of thermolysis for the leaving group of -OCH(3), the bond conversion energy (328.88 kJ/mol) for the amide II NH band to DKP NH band, and the CN bond formation energy (326.93 kJ/mol) of cyclization for the DKP in the APM molecule were also calculated from the Arrhenius equation. The total activation energy of the DKP formation via intramolecular cyclization was 261.33 kJ/mol, calculated by the above summation of the bond energy of cleavage, conversion, and formation, which was near to the value determined by the DSC or TGA method. This indicates that the microscopic FT-IR/DSC system is useful as a potential tool not only to investigate the degradation mechanism of drugs in the solid state but also to directly predict the bond energy of the reaction.

Investigation of recrystallization of amorphous trehalose through hot-humidity stage X-ray powder diffraction.

PubMed

Jójárt-Laczkovich, Orsolya; Katona, Gábor; Aigner, Zoltán; Szabó-Révész, Piroska

2016-12-01

The aim of this work was an investigation of the physical changes of the amorphous model material spray-dried trehalose through the use of various analytical techniques and to identify a suitable, rapid method able to quantify the changes. The crystallinity changes and recrystallization process of amorphous samples were investigated by hot-humidity stage X-ray powder diffractometry (HH-XRPD) with fresh samples, conventional X-ray powder diffractometry (XRPD) used stored samples and by differential scanning calorimetry (DSC). The data from the three methods were compared and the various forms of trehalose were analysed. HH-XRPD demonstrated that the recrystallization began at 40 and 60°C up to 45% RH and at 70°C up to 30% RH into dihydrate form. At 70°C up to 60% RH the anhydrous form of trehalose appeared too. Conventional XRPD results showed, that in the 28days stored samples the dihydrate form was detected at 40°C, 50% RH. Storage at 60°C, 40% RH resulted in the appearance of the anhydrous form and at 60°C, 50% RH both polymorphic forms were detected. By carrying out the DSC measurements at different temperatures the fraction of recrystallized trehalose dihydrate was detected. The recrystallization investigated by HH-XRPD and DSC followed Avrami kinetics, the calculated rate constants of isothermal crystallization (K) were same. Both HH-XRPD and conventional XRPD was suitable for the detection of the physical changes of the amorphous model material. DSC measurements showed similar results as HH-XRPD. Primarily HH-XRPD could be suggested for prediction, because the method is fast and every changes could be studied on one sample. Copyright © 2016 Elsevier B.V. All rights reserved.

Designing single- and multiple-shell sampling schemes for diffusion MRI using spherical code.

PubMed

Cheng, Jian; Shen, Dinggang; Yap, Pew-Thian

2014-01-01

In diffusion MRI (dMRI), determining an appropriate sampling scheme is crucial for acquiring the maximal amount of information for data reconstruction and analysis using the minimal amount of time. For single-shell acquisition, uniform sampling without directional preference is usually favored. To achieve this, a commonly used approach is the Electrostatic Energy Minimization (EEM) method introduced in dMRI by Jones et al. However, the electrostatic energy formulation in EEM is not directly related to the goal of optimal sampling-scheme design, i.e., achieving large angular separation between sampling points. A mathematically more natural approach is to consider the Spherical Code (SC) formulation, which aims to achieve uniform sampling by maximizing the minimal angular difference between sampling points on the unit sphere. Although SC is well studied in the mathematical literature, its current formulation is limited to a single shell and is not applicable to multiple shells. Moreover, SC, or more precisely continuous SC (CSC), currently can only be applied on the continuous unit sphere and hence cannot be used in situations where one or several subsets of sampling points need to be determined from an existing sampling scheme. In this case, discrete SC (DSC) is required. In this paper, we propose novel DSC and CSC methods for designing uniform single-/multi-shell sampling schemes. The DSC and CSC formulations are solved respectively by Mixed Integer Linear Programming (MILP) and a gradient descent approach. A fast greedy incremental solution is also provided for both DSC and CSC. To our knowledge, this is the first work to use SC formulation for designing sampling schemes in dMRI. Experimental results indicate that our methods obtain larger angular separation and better rotational invariance than the generalized EEM (gEEM) method currently used in the Human Connectome Project (HCP).

Comparison of protocols measuring diffusion and partition coefficients in the stratum corneum

PubMed Central

Rothe, H.; Obringer, C.; Manwaring, J.; Avci, C.; Wargniez, W.; Eilstein, J.; Hewitt, N.; Cubberley, R.; Duplan, H.; Lange, D.; Jacques‐Jamin, C.; Klaric, M.; Schepky, A.

2017-01-01

Abstract Partition (K) and diffusion (D) coefficients are important to measure for the modelling of skin penetration of chemicals through the stratum corneum (SC). We compared the feasibility of three protocols for the testing of 50 chemicals in our main studies, using three cosmetics‐relevant model chemicals with a wide range of logP values. Protocol 1: SC concentration‐depth profile using tape‐stripping (measures KSC/v and DSC/HSC 2, where HSC is the SC thickness); Protocol 2A: incubation of isolated SC with chemical (direct measurement of KSC/v only) and Protocol 2B: diffusion through isolated SC mounted on a Franz cell (measures KSC/v and DSC/HSC 2, and is based on Fick's laws). KSC/v values for caffeine and resorcinol using Protocol 1 and 2B were within 30% of each other, values using Protocol 2A were ~two‐fold higher, and all values were within 10‐fold of each other. Only indirect determination of KSC/v by Protocol 2B was different from the direct measurement of KSC/v by Protocol 2A and Protocol 1 for 7‐EC. The variability of KSC/v for all three chemicals using Protocol 2B was higher compared to Protocol 1 and 2A. DSC/HSC 2 values for the three chemicals were of the same order of magnitude using all three protocols. Additionally, using Protocol 1, there was very little difference between parameters measured in pig and human SC. In conclusion, KSC/v, and DSC values were comparable using different methods. Pig skin might be a good surrogate for human skin for the three chemicals tested. Copyright © 2017 The Authors Journal of Applied Toxicology published by John Wiley & Sons Ltd. PMID:28139006

Statistical Validation of Image Segmentation Quality Based on a Spatial Overlap Index1

PubMed Central

Zou, Kelly H.; Warfield, Simon K.; Bharatha, Aditya; Tempany, Clare M.C.; Kaus, Michael R.; Haker, Steven J.; Wells, William M.; Jolesz, Ferenc A.; Kikinis, Ron

2005-01-01

Rationale and Objectives To examine a statistical validation method based on the spatial overlap between two sets of segmentations of the same anatomy. Materials and Methods The Dice similarity coefficient (DSC) was used as a statistical validation metric to evaluate the performance of both the reproducibility of manual segmentations and the spatial overlap accuracy of automated probabilistic fractional segmentation of MR images, illustrated on two clinical examples. Example 1: 10 consecutive cases of prostate brachytherapy patients underwent both preoperative 1.5T and intraoperative 0.5T MR imaging. For each case, 5 repeated manual segmentations of the prostate peripheral zone were performed separately on preoperative and on intraoperative images. Example 2: A semi-automated probabilistic fractional segmentation algorithm was applied to MR imaging of 9 cases with 3 types of brain tumors. DSC values were computed and logit-transformed values were compared in the mean with the analysis of variance (ANOVA). Results Example 1: The mean DSCs of 0.883 (range, 0.876–0.893) with 1.5T preoperative MRI and 0.838 (range, 0.819–0.852) with 0.5T intraoperative MRI (P < .001) were within and at the margin of the range of good reproducibility, respectively. Example 2: Wide ranges of DSC were observed in brain tumor segmentations: Meningiomas (0.519–0.893), astrocytomas (0.487–0.972), and other mixed gliomas (0.490–0.899). Conclusion The DSC value is a simple and useful summary measure of spatial overlap, which can be applied to studies of reproducibility and accuracy in image segmentation. We observed generally satisfactory but variable validation results in two clinical applications. This metric may be adapted for similar validation tasks. PMID:14974593

Neonatal Desensitization Supports Long-Term Survival and Functional Integration of Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells in Rat Joint Cartilage Without Immunosuppression

PubMed Central

Zhang, Shufang; Jiang, Yang Zi; Zhang, Wei; Chen, Longkun; Tong, Tong; Liu, Wanlu; Mu, Qin; Liu, Hua; Ji, Junfeng; Ouyang, Hong Wei

2013-01-01

Immunological response hampers the investigation of human embryonic stem cells (hESCs) or their derivates for tissue regeneration in vivo. Immunosuppression is often used after surgery, but exhibits side effects of significant weight loss and allows only short-term observation. The purpose of this study was to investigate whether neonatal desensitization supports relative long-term survival of hESC-derived mesenchymal stem cells (hESC-MSCs) and promotes cartilage regeneration. hESC-MSCs were injected on the day of birth in rats. Six weeks after neonatal injection, a full-thickness cylindrical cartilage defect was created and transplanted with a hESC-MSC-seeded collagen bilayer scaffold (group d+s+c) or a collagen bilayer scaffold (group d+s). Rats without neonatal injection were transplanted with the hESC-MSC-seeded collagen bilayer scaffold to serve as controls (group s+c). Cartilage regeneration was evaluated by histological analysis, immunohistochemical staining, and biomechanical test. The role of hESC-MSCs in cartilage regeneration was analyzed by CD4 immunostaining, cell death detection, and visualization of human cells in regenerated tissues. hESC-MSCs expressed CD105, CD73, CD90, CD29, and CD44, but not CD45 and CD34, and possessed trilineage differentiation potential. Group d+s+c exhibited greater International Cartilage Repair Society (ICRS) scores than group d+s or group s+c. Abundant collagen type II and improved mechanical properties were detected in group d+s+c. There were less CD4+ inflammatory cell infiltration and cell death at week 1, and hESC-MSCs were found to survive as long as 8 weeks after transplantation in group d+s+c. Our study suggests that neonatal desensitization before transplantation may be an efficient way to develop a powerful tool for preclinical study of human cell-based therapies in animal models. PMID:22788986

Neonatal desensitization supports long-term survival and functional integration of human embryonic stem cell-derived mesenchymal stem cells in rat joint cartilage without immunosuppression.

PubMed

Zhang, Shufang; Jiang, Yang Zi; Zhang, Wei; Chen, Longkun; Tong, Tong; Liu, Wanlu; Mu, Qin; Liu, Hua; Ji, Junfeng; Ouyang, Hong Wei; Zou, Xiaohui

2013-01-01

Immunological response hampers the investigation of human embryonic stem cells (hESCs) or their derivates for tissue regeneration in vivo. Immunosuppression is often used after surgery, but exhibits side effects of significant weight loss and allows only short-term observation. The purpose of this study was to investigate whether neonatal desensitization supports relative long-term survival of hESC-derived mesenchymal stem cells (hESC-MSCs) and promotes cartilage regeneration. hESC-MSCs were injected on the day of birth in rats. Six weeks after neonatal injection, a full-thickness cylindrical cartilage defect was created and transplanted with a hESC-MSC-seeded collagen bilayer scaffold (group d+s+c) or a collagen bilayer scaffold (group d+s). Rats without neonatal injection were transplanted with the hESC-MSC-seeded collagen bilayer scaffold to serve as controls (group s+c). Cartilage regeneration was evaluated by histological analysis, immunohistochemical staining, and biomechanical test. The role of hESC-MSCs in cartilage regeneration was analyzed by CD4 immunostaining, cell death detection, and visualization of human cells in regenerated tissues. hESC-MSCs expressed CD105, CD73, CD90, CD29, and CD44, but not CD45 and CD34, and possessed trilineage differentiation potential. Group d+s+c exhibited greater International Cartilage Repair Society (ICRS) scores than group d+s or group s+c. Abundant collagen type II and improved mechanical properties were detected in group d+s+c. There were less CD4+ inflammatory cell infiltration and cell death at week 1, and hESC-MSCs were found to survive as long as 8 weeks after transplantation in group d+s+c. Our study suggests that neonatal desensitization before transplantation may be an efficient way to develop a powerful tool for preclinical study of human cell-based therapies in animal models.

Phase diagram and structural evolution of tin/indium (Sn/In) nanosolder particles: from a non-equilibrium state to an equilibrium state.

PubMed

Shu, Yang; Ando, Teiichi; Yin, Qiyue; Zhou, Guangwen; Gu, Zhiyong

2017-08-31

A binary system of tin/indium (Sn/In) in the form of nanoparticles was investigated for phase transitions and structural evolution at different temperatures and compositions. The Sn/In nanosolder particles in the composition range of 24-72 wt% In were synthesized by a surfactant-assisted chemical reduction method under ambient conditions. The morphology and microstructure of the as-synthesized nanoparticles were analyzed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD). HRTEM and SAED identified InSn 4 and In, with some Sn being detected by XRD, but no In 3 Sn was observed. The differential scanning calorimetry (DSC) thermographs of the as-synthesized nanoparticles exhibited an endothermic peak at around 116 °C, which is indicative of the metastable eutectic melting of InSn 4 and In. When the nanosolders were subjected to heat treatment at 50-225 °C, the equilibrium phase In 3 Sn appeared while Sn disappeared. The equilibrium state was effectively attained at 225 °C. A Tammann plot of the DSC data of the as-synthesized nanoparticles indicated that the metastable eutectic composition is about 62% In, while that of the DSC data of the 225 °C heat-treated nanoparticles yielded a eutectic composition of 54% In, which confirmed the attainment of the equilibrium state at 225 °C. The phase boundaries estimated from the DSC data of heat-treated Sn/In nanosolder particles matched well with those in the established Sn-In equilibrium phase diagram. The phase transition behavior of Sn/In nanosolders leads to a new understanding of binary alloy particles at the nanoscale, and provides important information for their low temperature soldering processing and applications.

Containment control of networked autonomous underwater vehicles: A predictor-based neural DSC design.

PubMed

Peng, Zhouhua; Wang, Dan; Wang, Wei; Liu, Lu

2015-11-01

This paper investigates the containment control problem of networked autonomous underwater vehicles in the presence of model uncertainty and unknown ocean disturbances. A predictor-based neural dynamic surface control design method is presented to develop the distributed adaptive containment controllers, under which the trajectories of follower vehicles nearly converge to the dynamic convex hull spanned by multiple reference trajectories over a directed network. Prediction errors, rather than tracking errors, are used to update the neural adaptation laws, which are independent of the tracking error dynamics, resulting in two time-scales to govern the entire system. The stability property of the closed-loop network is established via Lyapunov analysis, and transient property is quantified in terms of L2 norms of the derivatives of neural weights, which are shown to be smaller than the classical neural dynamic surface control approach. Comparative studies are given to show the substantial improvements of the proposed new method. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Interaction of choline salts with artificial biological membranes: DSC studies elucidating cellular interactions.

PubMed

Weaver, Katherine D; Van Vorst, Matthew P; Vijayaraghavan, R; Macfarlane, Douglas R; Elliott, Gloria D

2013-08-01

To better understand the relationship between the relative cytotoxicity of diluted ionic liquids and their specific interaction with biological membranes, the thermotropic behavior of model lipid membrane systems formulated in a series of choline based organic salts was investigated. Unilamellar vesicles prepared from dipalmitoylphosphatidylcholine were exposed to a series of choline phosphate salts at a concentration of 10mM at pH7.40, and the gel to liquid-crystalline state transition was examined using differential scanning calorimetry. The choline salts that were observed to have a low relative toxicity in previous studies induced minimal changes in the lipid phase transition behavior of these model membranes. In contrast, the salts choline bis(2,4,4-trimethylpentyl)phosphinate and choline bis(2-ethylhexyl)phosphate, both of which were observed to have high relative toxicity, caused distinct disruptions in the lipid phase transition behavior, consistent with penetration of the salts into the acyl chains of the phospholipids. choline bis(2,4,4-trimethylpentyl)phosphinate reduced the Tm and enthalpy of the main transition of dipalmitoylphosphatidylcholine while choline bis(2-ethylhexyl)phosphate induced the equilibration of alternate phases. Copyright © 2013 Elsevier B.V. All rights reserved.

Implementation of the Domino Sampling Waveform digitizer in the PIBETA experiment

NASA Astrophysics Data System (ADS)

Wang, Ying

The Domino Sampling Chip(DSC)-Waveform digitization system is a significant addition to electronics arsenal of PIBETA experiment. It is used to digitize waveforms from every photo tube in the detector. Through carefully programmed offline analysis of its raw data collected during regular runtime, better timing and energy resolution are achieved compared with feast's results. And more importantly, the geometric character of the digitized waveform which contains information of energy deposition of particle decays can be utilized for particle identification, a great advantage that regular unit could not possess. In addition to fastbus, incorporate DSC data through its offline analysis including timing and energy offset, scale calibration will contribute a final more precise result of PIBETA experiment.

Micro-differential scanning calorimeter for liquid biological samples

DOE PAGES

Wang, Shuyu; Yu, Shifeng; Siedler, Michael S.; ...

2016-10-20

Here, we developed an ultrasensitive micro-DSC (differential scanning calorimeter) for liquid protein sample characterization. Our design integrated vanadium oxide thermistors and flexible polymer substrates with microfluidics chambers to achieve a high sensitivity (6 V/W), low thermal conductivity (0.7 mW/K), high power resolutions (40 nW), and well-defined liquid volume (1 μl) calorimeter sensor in a compact and cost-effective way. Furthermore, we demonstrated the performance of the sensor with lysozyme unfolding. The measured transition temperature and enthalpy change were in accordance with the previous literature data. This micro-DSC could potentially raise the prospect of high-throughput biochemical measurement by parallel operation with miniaturizedmore » sample consumption.« less

Uncovering a reconstructive solid-solid phase transition in a metal-organic framework.

PubMed

Longley, L; Li, N; Wei, F; Bennett, T D

2017-11-01

A nanoporous three-dimensional metal-organic framework (MOF), ZnPurBr undergoes a transition to a previously unreported high-temperature phase, ZnPurBr-ht. The transition, which proceeds without mass loss, is uncovered through the use of differential scanning calorimetry (DSC). The new crystal structure was solved using single-crystal X-ray diffraction, and the mechanical properties of both phases investigated by nanoindentation and density functional theory. The anisotropy of the calculated Young's moduli showed good agreement with the crystallographic alignment of the stiff purinate organic linker. The results provide a prototypical example of the importance of the use of DSC in the MOF field, where its use is not currently standard in characterization.

Preparation of a novel breviscapine-loaded halloysite nanotubes complex for controlled release of breviscapine

NASA Astrophysics Data System (ADS)

Gao, Min; Lu, Liqian; Wang, Xiaoyue; Lin, Houke; Zhou, Qingsong

2017-11-01

For sustain the release rate and prolong half-life of breviscapine in vivo, the breviscapine-loaded halloysite nanotubes complex was prepared. The breviscapine was encapsulated into halloysite nanotubes (HNTs) using a vacuum process. The complex were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), transmission electron microscope (TEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy(FT-IR). The formation of breviscapine-loaded HNTs complex was proved by the test results of SEM, DSC, TEM and IR analysise. The results confirmed that breviscapine was successfully loaded in the halloysite nanotubes. Additionally, the in vitro drug release of breviscapine from breviscapine-loaded HNTs complex was investigated, the result indicated this complex has apparent sustained-release effect.

The mechanism of interactions between tea polyphenols and porcine pancreatic alpha‐amylase: Analysis by inhibition kinetics, fluorescence quenching, differential scanning calorimetry and isothermal titration calorimetry

PubMed Central

Sun, Lijun; Gidley, Michael J.

2017-01-01

Scope This study aims to use a combination of biochemical and biophysical methods to derive greater mechanistic understanding of the interactions between tea polyphenols and porcine pancreatic α‐amylase (PPA). Methods and results The interaction mechanism was studied through fluorescence quenching (FQ), differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC) and compared with inhibition kinetics. The results showed that a higher quenching effect of polyphenols corresponded to a stronger inhibitory activity against PPA. The red‐shift of maximum emission wavelength of PPA bound with some polyphenols indicated a potential structural unfolding of PPA. This was also suggested by the decreased thermostability of PPA with these polyphenols in DSC thermograms. Through thermodynamic binding analysis of ITC and inhibition kinetics, the equilibrium of competitive inhibition was shown to result from the binding of particularly galloylated polyphenols with specific sites on PPA. There were positive linear correlations between the reciprocal of competitive inhibition constant (1/K ic), quenching constant (K FQ) and binding constant (K itc). Conclusion The combination of inhibition kinetics, FQ, DSC and ITC can reasonably characterize the interactions between tea polyphenols and PPA. The galloyl moiety is an important group in catechins and theaflavins in terms of binding with and inhibiting the activity of PPA. PMID:28618113

Solid-Solid Phase Transition Kinetics of FOX-7

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

Burnham, A K; Weese, R K; Wang, R

Since it was developed in the late 1990s, 1,1-diamino-2,2-dinitroethene (FOX-7), with lower sensitivity and comparable performance to RDX, has received increasing interest. This paper will present our results for the phase changes of FOX-7 using DSC and HFC (Heat Flow Calorimetry). DSC thermal curves recorded at linear heating rates of 0.10, 0.35 and 1.0 C min{sup -1} show two endothermic peaks and two exothermic peaks. The two endothermic peaks represent solid-solid phase transitions, which have been observed in the literature at 114 C ({beta}-{gamma}) and 159 C ({gamma}-{delta}) by both DSC and XPD (X-ray powder diffraction) measurements. The first transitionmore » shifts from 114.5 to 115.8 C as the heating rate increases from 0.10 to 1.0 C min{sup -1}, while the second transition shifts from 158.5 to 160.4 C. Cyclical heating experiments show the endotherms and exotherms for a first heating through the {gamma} phase to the {delta} phase, a cooling and reversion to the {alpha} or {beta} phase, and a second heating to the {gamma} and {delta} phases. The data are interpreted using kinetic models with thermodynamic constraints.« less

Electrical conductivity, differential scanning calorimetry, X-ray diffraction, and 7Li nuclear magnetic resonance studies of n-C x H(2 x+1)OSO3Li ( x = 12, 14, 16, 18, and 20)

NASA Astrophysics Data System (ADS)

Hirakawa, Satoru; Morimoto, Yoshiaki; Honda, Hisashi

2015-04-01

Electrical conductivity ( σ), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) measurements of n-C x H (2 x+1) OSO 3Li ( x= 12, 14, 16, 18, and 20) crystals were performed as a function of temperature. In addition, σ, DSC, and XRD observations of n-C x H (2 x+1) OSO 3Na and n-C x H (2 x+1) OSO 3K ( x= 12, 14, 16, 18, and 20) crystals were carried out for comparison. DSC results of the salts revealed several solid-solid phase transitions with large entropy changes (Δ S). For n-C 18 H 37 OSO 3Li and n-C 20 H 41 OSO 3Li salts, each melting point produced a small Δ S mp value compared with the total entropy change in the solid phases (Δ S tr1+Δ S tr2). Additionally, Li + ion diffusion was detected in the highest temperature solid phases. For K salts, larger σ values were detected for potassium alkylsulfates compared with those reported for alkyl carboxylate. 7Li NMR spectra of n-C 18 H 37 OSO 3Li crystals recorded in the low-temperature phase showed large asymmetry parameters, suggesting the Li + ions are localized at asymmetric sites in the crystals.

Accurate segmentation framework for the left ventricle wall from cardiac cine MRI

NASA Astrophysics Data System (ADS)

Sliman, H.; Khalifa, F.; Elnakib, A.; Soliman, A.; Beache, G. M.; Gimel'farb, G.; Emam, A.; Elmaghraby, A.; El-Baz, A.

2013-10-01

We propose a novel, fast, robust, bi-directional coupled parametric deformable model to segment the left ventricle (LV) wall borders using first- and second-order visual appearance features. These features are embedded in a new stochastic external force that preserves the topology of LV wall to track the evolution of the parametric deformable models control points. To accurately estimate the marginal density of each deformable model control point, the empirical marginal grey level distributions (first-order appearance) inside and outside the boundary of the deformable model are modeled with adaptive linear combinations of discrete Gaussians (LCDG). The second order visual appearance of the LV wall is accurately modeled with a new rotationally invariant second-order Markov-Gibbs random field (MGRF). We tested the proposed segmentation approach on 15 data sets in 6 infarction patients using the Dice similarity coefficient (DSC) and the average distance (AD) between the ground truth and automated segmentation contours. Our approach achieves a mean DSC value of 0.926±0.022 and AD value of 2.16±0.60 compared to two other level set methods that achieve 0.904±0.033 and 0.885±0.02 for DSC; and 2.86±1.35 and 5.72±4.70 for AD, respectively.

[Investigation on chromatogram-pharmacodynamics relationship of Angelica sinensis on effect of replenishing blood].

PubMed

Yang, Ying-Lai; Cui, Fang; Hu, Fang; Guo, Long; Yang, Tao; Li, Ying-Dong; Feng, Shi-Lan

2013-11-01

Blood deficiency model of mice was copied by subcutaneous injection with 200, 100 and 100 mg x kg(-1) (0.01 mL x g(-1)) acetyl phenylhydrazine (APH) at the frist, fourth, and seventh days. Mice in each group were perfused with different extracted parts of Angelica sinensis (drug dosage was 2.4 g x kg(-1)) at the tenth day, once a day for 10 days. Then compare the influence of different extracted parts of Angelica sinensis to RBC, Hb, PLT and thymus, spleen and weight changes of blood deficiency mice. The peak areas of each common peak from HPLC fingerprint were associated with the date of replenishing blood pharmacodynamics efficacy by using gray relation statistic, which was used to research the chromatogram-pharmacodynamics relationship. The results showed that the part of DSC has the better effect in replenishing blood. The contribution degree of the DSC to replenishing blood of each component were determined by correlation size, and ferulic acid made the largest contribution, but contribution of other components should not be ignored. In this paper, we research the relationship of the HPLC fingerprint and spectrum activity relationship, determine the material basis of the DSC for replenishing blood, and provide effective way to represent the spectral correlation effect.

Characterization of organic matter of plants from lakes by thermal analysis in a N2 atmosphere

NASA Astrophysics Data System (ADS)

Guo, Fei; Wu, Fengchang; Mu, Yunsong; Hu, Yan; Zhao, Xiaoli; Meng, Wei; Giesy, John P.; Lin, Ying

2016-03-01

Organic matter (OM) has been characterized using thermal analysis in O2 atmospheres, but it is not clear if OM can be characterized using slow thermal degradation in N2 atmospheres (STDN). This article presents a new method to estimate the behavior of OM in anaerobic environment. Seventeen different plants from Tai Lake (Ch: Taihu), China were heated to 600 °C at a rate of 10 °C min-1 in a N2 atmosphere and characterized by use of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). DSC chromatograms were compared with 9 standard compounds. Seven peaks were observed in DSC chromatograms, 2 main peaks strongly correlated with biochemical indices, and one main peak was a transitional stage. Energy absorbed by a peak at approximately 200 °C and total organic carbon were well correlated, while energy absorbed at approximately 460 °C was negatively correlated with lignin content. Presence of peaks at approximately 350 and 420 °C varied among plant biomass sources, providing potential evidence for biomass identification. Methods of STDN reported here were rapid and accurate ways to quantitatively characterize OM, which may provide useful information for understanding anaerobic behaviors of natural organic matters.

Xeroderma Pigmentosum with Severe Neurological Manifestations/De Sanctis–Cacchione Syndrome and a Novel XPC Mutation

PubMed Central

Hernandez-Quiceno, Sara

2017-01-01

Several genetic disorders caused by defective nucleotide excision repair that affect the skin and the nervous system have been described, including Xeroderma Pigmentosum (XP), De Sanctis–Cacchione syndrome (DSC), Cockayne syndrome, and Trichothiodystrophy. Cutaneous photosensitivity with an increased risk of skin malignancy is a common feature of these disorders, but clinical manifestations commonly overlap these syndromes. Several genes have been found to be altered in these pathologies, but we lack more genotype-phenotype correlations in order to make an accurate diagnosis. Very few cases of DSC syndrome have been reported in the literature. We present a case of a 12-year-old Colombian male, with multiple skin lesions in sun-exposed areas from the age of 3 months and a history of 15 skin cancers. He also displayed severe neurologic abnormalities (intellectual disability, ataxia, altered speech, and hyperreflexia), short stature, and microcephaly, which are features associated with DSC. Genetic testing revealed a novel germline mutation in the XP-C gene (c.547A>T). This is the first case of an XP-C mutation causing De Sanctis–Cacchione syndrome. Multigene panel testing is becoming more widely available and accessible in the clinical setting and will help rapidly unveil the molecular etiology of these rare genetic disorders. PMID:28255305

Kinetics of Glass Transition and Crystallization of a Zr40Hf10Ti4Y1Al10Cu25Ni7Co2Fe1 Bulk Metallic Glass with High Mixing Entropy

NASA Astrophysics Data System (ADS)

Gong, Pan; Wang, Sibo; Li, Fangwei; Wang, Xinyun

2018-04-01

The kinetics of glass transition and crystallization of a novel Zr40Hf10Ti4Y1Al10Cu25Ni7Co2Fe1 bulk metallic glass (BMG) with high mixing entropy have been studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The continuous DSC curves show five stages of crystallization at lower heating rates (≤ 20 K/min). The activation energies of glass transition were determined by Moynihan and Kissinger methods, while the activation energies of crystallization were calculated utilizing Kissinger, Ozawa, and Boswell models. The crystalline phases corresponding to each crystallization step have been found out. The kinetic fragility of Zr40Hf10Ti4Y1Al10Cu25Ni7Co2Fe1 BMG has also been evaluated. Based on the isothermal DSC curves, the Avrami exponent, evaluated from the Johnson-Mehl-Avrami equation, has been analyzed in detail. The current study reveals that the crystallization behavior of Zr40Hf10Ti4Y1Al10Cu25Ni7Co2Fe1 BMG exhibits characteristics of both the high entropy BMGs and traditional BMGs with a single principal element, leading to its high glass-forming ability.

[Effect of crystallization temperature of palm oil on its crystallization. IV. The influence of tripalmitoylglycerol (PPP) on the crystallization of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 1,2-dioleoyl-3-palmitoyl-glycerol (POO)].

PubMed

Mihara, Hiroaki; Ishiguro, Takashi; Fukano, Hidenori; Taniuchi, Shigeyuki; Ogino, Keizo

2007-01-01

Triacylglycerin in Palm Oil contains POP (1,3-dipalmitoyl-2-oleoyl-glycerol) at 30%, POO (1,2-dioleoyl-3-palmitoyl-glycerol) at 20% and PPP (tripalmitoylglycerol) at 5%. The crystallization temperature of PPP is high and the rates of crystal nuclear formation and growth are fast. It is thus considered that PPP may have some effect on the manner or mode of Palm Oil. Examination was thus made to clarify how PPP may affect the crystallization of POP and POO by differential scanning calorimetry (DSC) and X ray diffractometry (XRD) conducted on PPP/POP and PPP/POO mixtures. High and low temperature peaks were noted to appear on the DSC crystallization curve for either of these mixtures. The high temperature peak was considered possibly due to PPP, and the low temperature peak, to POP or POO. DSC isothermal analysis indicated the rate of crystal growth of either mixture to exceed that of pure of POP or POO. Crystal mixture structure was also seen to be complicated than either compound in pure form. The present findings thus clearly indicate that clarification should be made of the effects of high melting point triacylglycerin, such as PPP, on the crystallization of Palm Oil.

Calorimetric Studies of Precipitation and Dissolution Kinetics in Aluminum Alloys 2219 and 7075

NASA Astrophysics Data System (ADS)

Papazian, John M.

1982-05-01

Differential scanning calorimetry (DSC) was used to study the kinetics of precipitation and dissolution of metastable and stable phases in aluminum alloys 2219 and 7075. A comparison of DSC scans obtained at heating rates of 1, 5, 10, and 20 K per minute showed that, during a DSC scan, the rates of precipitation of θ' and θ in 2219 and η' and η in 7075 were limited by their reaction kinetics. Likewise, the rates of dissolution of GP zones, θ' and η', were found to be dominated by kinetics. In contrast, the dissolution of θ and η was dominated by the thermodynamic equilibrium between these phases and the matrix. Analysis of the kinetically dominated reaction peaks and their dependence on heating rate and particle size showed that the GP zone dissolution reaction could best be described by a three-dimensional volume diffusion limited rate expression with an activation energy equal to that for diffusion. The rate of formation of θ' was best described by an Avrami expression with n = 1.1, indicating that nucleation was not the rate controlling step. A pronounced dependence of the θ' formation rate on prior plastic deformation was observed and ascribed to the influence of the matrix dislocation density on diffusivity.

The effects of 60Co γ-ray on poly(ethylene-co-vinyl acetate)/carbon black composites

NASA Astrophysics Data System (ADS)

Lee, Kyoung-Yong; Kim, Ki-Yup

2008-04-01

Cables used in a nuclear power plant are irradiation suppressing ones. Until now, researches on the irradiation suppressing cables have mainly been focused on insulation materials. Therefore, in this paper, the non-isothermal crystallization behaviors and degradation characteristics of ethylene vinyl acetate-carbon black (EVA-CB), used as a shielding material, were investigated by means of the Differential scanning calorimetry (DSC) and chemiluminescence analyzer (CL). The specimens were cooled after removing thermal history at 150 °C for 5 min by changing the cooling rates to 5, 7.5, 10, 15 and 20 °C/min with DSC. In addition, after maintaining a thermal equilibrium at each temperature of 25, 50, 75, 100, 125, 150 and 175 °C, their thermoluminescence was measured for 20 min with CL equipment. The 60Co γ-ray was used for irradiation. Tc, T0, T∞ and t1/2 in the DSC experiments are found to decrease gradually as radiation dose increases. Secondly, with the CL experiment, the 0.1, 0.25 and 0.5 MGy EVA-CB composites were found to show a much smaller thermoluminescence than the intact EVA-CB composites, while the 0.75 and 1 MGy EVA-CB composites were found to show a much higher thermoluminescence than ones.

A new mechanism for aging: chemical "age spots" in immortal DNA strands in distributed stem cells.

PubMed

Sherley, James L

2008-01-01

The existence of immortal DNA strands (IDSs) in distributed stem cells (DSCs) of adult human tissues was first inferred by Cairns. Cairns deduced the existence of IDSs by connecting two seemingly disparate observations - one his own and the other belonging to Lark. Cairns noted a mathematical discrepancy between predicted human tissue cell mutation rates and human cancer incidence. He integrated this insight with Lark's earlier discovery of non-random mitotic chromosome segregation in both plant root tip cells and mouse fetal fibroblast cultures to predict the existence of IDSs as the essential elements of a mutation-defense mechanism in DSCs. Since Cairns' seminal prediction, several laboratories have identified IDSs in diverse mammalian cells with DSC properties. Past studies focused on the potential roles of IDSs as originally envisioned in DSC genetic fidelity or in the maintenance of the DSC phenotype. Another possible consequence of IDSs, aging, has received little attention. Herein, the potential for cumulative chemical modifications and decompositions (i.e., "age spots") of IDSs in DSCs to act as a major determinant of human aging is considered. If accrued chemical alterations of IDSs prove to be essential determinants of aging, then a means to restore IDSs may yield new strategies for tissue rejuvenation.

Use of a training program to enhance NICU nurses' cognitive abilities for assessing preterm infant behaviors and offering supportive interventions.

PubMed

Liaw, Jen-Jiuan

2003-06-01

This study tested the use of a developmentally supportive care (DSC) training program in the form of videotaped and personalized instruction to increase nurses' cognitive abilities for assessing preterm infant behavioral signals and offering supportive care. The study used a two-group pre-test post-test quasi-experimental repeated measures design. The participants were 25 NICU nurses, 13 in the intervention group, and 12 in the control group. An instrument developed for the purpose of the study was a video test that measured the effectiveness of the DSC training. The video test questionnaires were administered to the participants twice with an interval of four weeks. ANCOVA controlling the baseline scores was used for data analysis. In general, the results support the hypothesis that nurses' cognitive abilities were enhanced after the DSC training. The increase in nurses' cognitive abilities is the prerequisite for behavioral change, based on the assumptions of Bandura's Social Cognitive Learning Theory (Bandura, 1986). As nurses' cognitive abilities increased, it would be possible that nurse behaviors in taking care of these preterm infants might change. Therefore, the author recommends that in order to improve NICU care quality and the outcomes of preterm infants, the concepts of developmentally supportive care be incorporated into NICU caregiving practice by educating nurses.

Phase Diagram of an Ethylene Glycol-Hexamethylphosphorotriamide System

NASA Astrophysics Data System (ADS)

Solonina, I. A.; Rodnikova, M. N.; Kiselev, M. R.; Khoroshilov, A. V.

2018-02-01

The phase diagram of an ethylene glycol (EG)-hexamethylphosphorotriamide (HMPT) system is studied over two wide temperature intervals (+25°C…-90°C…+40°C) and (-150°C…+40°C) by means of differential scanning calorimetry using INTERTECH DSC Q100 and METTLER TA4000 DSC instruments (Switzerland) in the DSC30 mode with variable cooling/heating rates. Substantial overcooling of the liquid phase, a glass transition, and different types of interaction are observed in the system. No thermal effects are observed in intermediate range of concentrations during the slow cooling/heating processes, and the system remains liquid until the glass transition. The presence of such a metastable phase is attributed to a sharp rise in the viscosity of the system due to different kinds of interaction between the components. HMPT: 2EG and HMPT: EG compounds with crystallization temperatures of +5 and -0.5°C, respectively, are observed upon rapid cooling and slow heating. Changes in enthalpy are calculated for all of the observed thermal effects. The distinction from the phase diagram of H2O-HMFT (literary data) is explained by the difference in the interactions between system components and by the structural differences between EG and H2O.

Preparation and Evaluation of Multiple Nanoemulsions Containing Gadolinium (III) Chelate as a Potential Magnetic Resonance Imaging (MRI) Contrast Agent.

PubMed

Sigward, Estelle; Corvis, Yohann; Doan, Bich-Thuy; Kindsiko, Kadri; Seguin, Johanne; Scherman, Daniel; Brossard, Denis; Mignet, Nathalie; Espeau, Philippe; Crauste-Manciet, Sylvie

2015-09-01

The objective was to develop, characterize and assess the potentiality of W1/O/W2 self-emulsifying multiple nanoemulsions to enhance signal/noise ratio for Magnetic Resonance Imaging (MRI). For this purpose, a new formulation, was designed for encapsulation efficiency and stability. Various methods were used to characterize encapsulation efficiency ,in particular calorimetric methods (Differential Scanning Calorimetry (DSC), thermogravimetry analysis) and ultrafiltration. MRI in vitro relaxivities were assessed on loaded DTPA-Gd multiple nanoemulsions. Characterization of the formulation, in particular of encapsulation efficiency was a challenge due to interactions found with ultrafiltration method. Thanks to the specifically developed DSC protocol, we were able to confirm the formation of multiple nanoemulsions, differentiate loaded from unloaded nanoemulsions and measure the encapsulation efficiency which was found to be quite high with a 68% of drug loaded. Relaxivity studies showed that the self-emulsifying W/O/W nanoemulsions were positive contrast agents, exhibiting higher relaxivities than those of the DTPA-Gd solution taken as a reference. New self-emulsifying multiple nanoemulsions that were able to load satisfactory amounts of contrasting agent were successfully developed as potential MRI contrasting agents. A specific DSC protocol was needed to be developed to characterize these complex systems as it would be useful to develop these self-formation formulations.

Exploration of a new method in determining the glass transition temperature of BMGs by electrical resistivity

NASA Astrophysics Data System (ADS)

Guo, Jing; Zu, Fangqiu; Chen, Zhihao; Zheng, Shubin; Yuan, Yuan

2005-07-01

Based on a brief retrospect of the method in establishing Tg of the bulk metallic glasses (BMGs), some perplexities concerning this are pointed out. With the experimental results of Zr-Al-Ni-Cu-X (Nb,Ti) BMGs, a electrical resistivity method is proposed to determine the glass transition temperature of BMGs. With the method, we define two kinds of characteristic temperature related to the glass transition, Tg-dep and Tg-int, respectively. By comparing Tg-dep and Tg-int with Tg determined by the DSC method, we have found that, for the same alloy at the same heating rate, Tg-dep is very close to Tg-onset while Tg-int is approximate to Tg-mid. As a method to determine the glass transition temperature, the electrical resistivity method has proved to be more convenient and practical in comparison with the DSC method, especially when the DSC curve cannot show the glass transition character of BMGs. In addition, we would emphasize that when we refer to Tg, it is necessary to expatiate on the way of denoting the glass transition temperature, such as Tg-dep or Tg-int ( Tg-onset or Tg-mid), and on the heating rate, in order to avoid ambiguity.

The Search for Habitable Environments in the Solar System

NASA Astrophysics Data System (ADS)

McCleese, Daniel

2005-07-01

All space faring nations devote a portion of their resources to exploring thesolar system. NASA has a forty-year history of robotic missions reaching into deep spacefor a better understanding of our origins, the evolution of our planet, and our destiny.For the past decade, NASA has placed considerable emphasis on the search for life beyondEarth. Missions to the rocky terrestrial planets and the moons of the gas giants seekanswers to the question: Are other worlds in the solar system habitable by simpleorganisms? By framing its search objective in this way, NASA motivates investigations ofthe fundamentals of what makes a planet an abode for life, and what ingredients arerequired for the origin and evolution of life. In this lecture, we focus on thestrategies and results of the search thus far. We will discuss recent scientific missionsto Mars, Europa, and Titan.Dr. Dan McCleese is the Chief Scientist for NASA's Mars ExplorationProgram at JPL. In this role he has worked with NASA and the international sciencecommunity to establish the current science strategy for exploring Mars. Dan's personalscience interests are focused on acquiring and interpreting climatological data sets forthe terrestrial planets. Specific research topics include development of the firstclimatology of cloud height for Earth, upper atmospheric cloud and thermal structure ofVenus, and, at present, the modern climate of Mars. He is the Principal Investigator forthe Mars Climate Sounder on the Mars Reconnaissance Orbiter to be launched in 2005. Inthis investigation, measurements of atmospheric water vapor, temperature and condensates,and the energy balance of the polar caps are emphasized. Dr. McCleese was a FulbrightScholar at Oxford University receiving a D.Phil. degree in Atmospheric Physics.

Reducing social isolation and loneliness in older people: a systematic review protocol

PubMed Central

Landeiro, Filipa; Barrows, Paige; Nuttall Musson, Ellen

2017-01-01

Introduction Social isolation and loneliness affect approximately one-third to one-half of the elderly population and have a negative impact on their physical and mental health. Group-based interventions where facilitators are well trained and where the elderly are actively engaged in their development seem to be more effective, but conclusions have been limited by weak study designs. We aim to conduct a systematic review to assess the effectiveness of health promotion interventions on social isolation or loneliness in older people. Methods and analysis A systematic review was conducted in Medline, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Applied Social Sciences Index and Abstracts, LILACS, OpenGrey and the Cochrane Library on peer-reviewed studies and doctoral theses published between 1995 and 2016 evaluating the impact of health promotion interventions on social isolation and/or loneliness for individuals aged 60 and over. Two reviewers will independently assess each study for inclusion and disagreements will be resolved by a third reviewer. Data will be extracted using a predefined pro forma following best practice. Study quality will be assessed with the Effective Public Health Practice Project quality assessment tool. A narrative synthesis of all studies will be presented by type of outcome (social isolation or loneliness) and type of intervention. If feasible, the effectiveness data will be synthesised using appropriate statistical techniques. Ethics and dissemination This systematic review is exempt from ethics approval because the work is carried out on published documents. The findings of the review will be disseminated in a related peer-reviewed journal and presented at conferences. They will also contribute to a DPhil thesis. Trial registration number CRD42016039650 PMID:28515187

Pathology and distribution of sea turtles landed as bycatch in the Hawaii-based North Pacific pelagic longline fishery

USGS Publications Warehouse

Work, Thierry M.; Balazs, George H.

2010-01-01

We examined the gross and microscopic pathology and distribution of sea turtles that were landed as bycatch from the Hawaii, USA–based pelagic longline fishery and known to be forced submerged. Olive ridley turtles (Lepidochelys olivacea) composed the majority of animals examined, and hook-induced perforation of the esophagus was the most common gross lesion followed by perforation of oral structures (tongue, canthus) and of flippers. Gross pathology in the lungs suggestive of drowning was seen in 23 of 71 turtles. Considering only the external gross findings, the pathologist and the observer on board the longline vessel agreed on hook-induced lesions only 60% of the time thereby illustrating the limitations of depending on external examination alone to implicate hooking interactions or drowning as potential cause of sea turtle mortality. When comparing histology of drowned turtles to a control group of nondrowned turtles, the former had significantly more pulmonary edema, hemorrhage, and sloughed columnar epithelium. These microscopic changes may prove useful to diagnose suspected drowning in sea turtles where history of hooking or netting interactions is unknown.

Validation of the SWMF Magnetosphere: Fields and Particles

NASA Astrophysics Data System (ADS)

Welling, D. T.; Ridley, A. J.

2009-05-01

The Space Weather Modeling Framework has been developed at the University of Michigan to allow many independent space environment numerical models to be executed simultaneously and coupled together to create a more accurate, all-encompassing system. This work explores the capabilities of the framework when using the BATS-R-US MHD code, Rice Convection Model (RCM), the Ridley Ionosphere Model (RIM), and the Polar Wind Outflow Model (PWOM). Ten space weather events, ranging from quiet to extremely stormy periods, are modeled by the framework. All simulations are executed in a manner that mimics an operational environment where fewer resources are available and predictions are required in a timely manner. The results are compared against in-situ measurements of magnetic fields from GOES, Polar, Geotail, and Cluster satellites as well as MPA particle measurements from the LANL geosynchronous spacecraft. Various metrics are calculated to quantify performance. Results when using only two to all four components are compared to evaluate the increase in performance as new physics are included in the system.

Environmental dynamics of red Noctiluca scintillans bloom in tropical coastal waters.

PubMed

Baliarsingh, S K; Lotliker, Aneesh A; Trainer, Vera L; Wells, Mark L; Parida, Chandanlal; Sahu, Biraja K; Srichandan, Suchismita; Sahoo, Subhashree; Sahu, K C; Kumar, T Sinivasa

2016-10-15

An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region along the east coast of India, an important site for mass nesting events of the vulnerable Olive Ridley sea turtle. At its peak, densities of NS were 3.3×10(5) cells-l(-1), with low relative abundance of other phytoplankton. The peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. Ammonium concentrations increased by approximately 4-fold in the later stages of bloom, coincident with stable NS abundance and chlorophyll concentrations in the nano- and microplankton. This increase likely was attributable to release of intracellular ammonium accumulated through NS grazing. Dissolved oxygen concentrations decreased in sub-surface waters to near hypoxia. Micro-phytoplankton increasingly dominated chlorophyll-a biomass as the bloom declined, with diminishing picoplankton abundance likely the result of high predation by the ciliate Mesodinium rubrum. Together, these data illustrate factors that can disrupt ecosystem balance in this critically important Indian coastal region. Copyright © 2016 Elsevier Ltd. All rights reserved.

Utility of Fite-Faraco stain for both mast cell count and bacillary index in skin biopsies of leprosy patients.

PubMed

Chatura, K R; Sangeetha, S

2012-01-01

To assess the utility of a single stain for both mast cell count and bacillary index (BI), 50 skin-biopsie patients were stained with Fite-Faraco (FF) stain, viewed under oil immersion and BI calculated using the Ridley's logarithmic scale, and mast cells counted as the number of cells per mm2. Mean mast cell count per mm2 at the tuberculoid pole was lowest in TT 7.9 and highest in BT 14.23. At the lepromatous end, it was highest in BL 9.21, while in LL it was 8.23. Highest counts were seen in the borderline types overall. The correlation coefficient between histopathological diagnosis and BI is 0.822 which is a positive correlation to a significant degree. The correlation coefficient between histopathological diagnosis and mast cell count was found to be -0.17, which is a negative correlation but not to a significant degree. FF stain was utilised to visualise both bacilli for estimation of BI and mast cells for mast cell count, a seldom attempted feature in literature.

Segregation of Visual Response Properties in the Mouse Superior Colliculus and Their Modulation during Locomotion

PubMed Central

2017-01-01

The superior colliculus (SC) receives direct input from the retina and integrates it with information about sound, touch, and state of the animal that is relayed from other parts of the brain to initiate specific behavioral outcomes. The superficial SC layers (sSC) contain cells that respond to visual stimuli, whereas the deep SC layers (dSC) contain cells that also respond to auditory and somatosensory stimuli. Here, we used a large-scale silicon probe recording system to examine the visual response properties of SC cells of head-fixed and alert male mice. We found cells with diverse response properties including: (1) orientation/direction-selective (OS/DS) cells with a firing rate that is suppressed by drifting sinusoidal gratings (negative OS/DS cells); (2) suppressed-by-contrast cells; (3) cells with complex-like spatial summation nonlinearity; and (4) cells with Y-like spatial summation nonlinearity. We also found specific response properties that are enriched in different depths of the SC. The sSC is enriched with cells with small RFs, high evoked firing rates (FRs), and sustained temporal responses, whereas the dSC is enriched with the negative OS/DS cells and with cells with large RFs, low evoked FRs, and transient temporal responses. Locomotion modulates the activity of the SC cells both additively and multiplicatively and changes the preferred spatial frequency of some SC cells. These results provide the first description of the negative OS/DS cells and demonstrate that the SC segregates cells with different response properties and that the behavioral state of a mouse affects SC activity. SIGNIFICANCE STATEMENT The superior colliculus (SC) receives visual input from the retina in its superficial layers (sSC) and induces eye/head-orientating movements and innate defensive responses in its deeper layers (dSC). Despite their importance, very little is known about the visual response properties of dSC neurons. Using high-density electrode recordings and novel

TU-CD-BRA-04: Evaluation of An Atlas-Based Segmentation Method for Prostate and Peripheral Zone Regions On MRI

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

Nelson, AS; Piper, J; Curry, K

2015-06-15

Purpose: Prostate MRI plays an important role in diagnosis, biopsy guidance, and therapy planning for prostate cancer. Prostate MRI contours can be used to aid in image fusion for ultrasound biopsy guidance and delivery of radiation. Our goal in this study is to evaluate an automatic atlas-based segmentation method for generating prostate and peripheral zone (PZ) contours on MRI. Methods: T2-weighted MRIs were acquired on 3T-Discovery MR750 System (GE, Milwaukee). The Volumes of Interest (VOIs): prostate and PZ were outlined by an expert radiation oncologist and used to create an atlas library for atlas-based segmentation. The atlas-segmentation accuracy was evaluatedmore » using a leave-one-out analysis. The method involved automatically finding the atlas subject that best matched the test subject followed by a normalized intensity-based free-form deformable registration of the atlas subject to the test subject. The prostate and PZ contours were transformed to the test subject using the same deformation. For each test subject the three best matches were used and the final contour was combined using Majority Vote. The atlas-segmentation process was fully automatic. Dice similarity coefficients (DSC) and mean Hausdorff values were used for comparison. Results: VOIs contours were available for 28 subjects. For the prostate, the atlas-based segmentation method resulted in an average DSC of 0.88+/−0.08 and a mean Hausdorff distance of 1.1+/−0.9mm. The number of patients (#) in DSC ranges are as follows: 0.60–0.69(1), 0.70–0.79(2), 0.80–0.89(13), >0.89(11). For the PZ, the average DSC was 0.72+/−0.17 and average Hausdorff of 0.9+/−0.9mm. The number of patients (#) in DSC ranges are as follows: <0.60(4), 0.60–0.69(6), 0.70–0.79(7), 0.80–0.89(9), >0.89(1). Conclusion: The MRI atlas-based segmentation method achieved good results for both the whole prostate and PZ compared to expert defined VOIs. The technique is fast, fully automatic, and has the

7 CFR 1717.652 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., all investments properly recorded on the borrower's books and records in investment accounts as those.... Operating DSC means Operating Debt Service Coverage (ODSC) of the borrower's electric system calculated as...

The Thermal Conductivity Measurements of Solid Samples by Heat Flux Differantial Scanning Calorimetry

NASA Astrophysics Data System (ADS)

Kök, M.; Aydoǧdu, Y.

2007-04-01

The thermal conductivity of polyvinylchloride (PVC), polysytrene (PS) and polypropylene (PP) were measured by heat flux DSC. Our results are in good agreement with the results observed by different methods.

Glass Reinforcement of Various Epoxy Resins-Polyurea Systems

NASA Astrophysics Data System (ADS)

Joshi, Medha; Jauhari, Smita

2012-07-01

Polyureas (PUs) were prepared by the polycondensation reaction of disperse dyes containing -NH2 group and toluene 2, 4-diisocyanate. The disperse dyes have been prepared by coupling of various 2-diazobenzothiazoles with 1,3-benzenediamine. All the PUs were characterized by elemental analysis, spectral studies, number average molecular weight ( {overline{{Mn}} } ), and thermogravimetry. Further reaction of PUs was carried out with an epoxy resin (i.e., DGEBA). The curing study of prepared resins was monitored by differential scanning calorimeter (DSC). Based on DSC, thermograms glass fiber-reinforced composites have been laminated and characterized by chemical, mechanical, and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA). The laminated composites showed excellent resistance properties against chemicals and good mechanical and electrical properties.

Characterization of Thermal Behavior of Epoxy Composites Reinforced with Curaua Fibers by Differential Scanning Calorimetry

NASA Astrophysics Data System (ADS)

Barcelos, Mariana A.; Ribeiro, Carolina Gomes D.; Ferreira, Jordana; Vieira, Janaina da S.; Margem, Frederico M.; Monteiro, Sergio N.

Epoxy composites reinforced with natural lignocellulosic fibers have, in recent times, been gaining attention in engineering areas as lighter and cheaper alternatives for traditional composites such as the "fiberglass". The curaua fiber is the one strongest today being considered as reinforcement of composites for automobile interior parts. In fact, several studies are currently being dedicated to curaua fiber composites since physical and mechanical properties are required for practical uses. In this work, the thermal behavior of epoxy composites reinforced with up to 30 % in volume of curaua fibers was investigated by differential scanning calorimetry, DSC. The results showed endothermic and exothermic events associated with water release and possible molecular chain amorphous transformation. Comparison with similar composites permitted to propose mechanism that explains this DSC thermal behavior.

Physiochemical Characterization and Release Rate Studies of SolidDispersions of Ketoconazole with Pluronic F127 and PVP K-30

PubMed Central

Kumar, Pankaj; Mohan, Chander; KanamSrinivasan Uma Shankar, Mara; Gulati, Monica

2011-01-01

In the present study solid dispersions of the antifungal drug Ketoconazole were prepared with Pluronic F-127 and PVP K-30 with an intention to improve its dissolution properties. Investigations of the properties of the dispersions were performed using release studies, Differential scanning calorimetery (DSC), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR). The results obtained showed that the rate of dissolution of Ketoconazole was considerably improved when formulated in solid dispersions with PVP K-30 and Pluronic F-127 as compared with pure drug and physical mixtures. The results from DSC and XRD studies showed the transition of crystalline nature of drug to amorphous form, while FTIR studies demonstrated the absence of drug-carriers interaction. PMID:24250403

Stability of some Cactaceae proteins based on fluorescence, circular dichroism, and differential scanning calorimetry measurements.

PubMed

Gorinstein, S; Zemser, M; Vargas-Albores, F; Ochoa, J L; Paredes-Lopez, O; Scheler, C; Aksu, S; Salnikow, J

1999-02-01

Characterization of three cactus proteins (native and denatured) from Machaerocereus gummosus (Pitahaya agria), Lophocereu schottii (Garambullo), and Cholla opuntia (Cholla), was based on electrophoretic, fluorescence, CD (circular dichroism), DSC (differential scanning calorimetry), and FT-IR (Fourier transform infrared) measurements. The obtained results of intrinsic fluorescence, DSC, and CD were dissimilar for the three species of cactus, providing evidence of differences in secondary and tertiary structures. Cactus proteins may be situated in the following order corresponding to their relative stability: Machaerocereus gummosus (Pitahaya agria) > Cholla opuntia (Cholla) > Lophocereu schottii (Garambullo). Thermodynamic properties of proteins and their changes upon denaturation (temperature of denaturation, enthalphy, and the number of ruptured hydrogen bonds) were correlated with the secondary structure of proteins and disappearance of alpha-helix.