A Novel Strategy for Isolation, Molecular and Functional Characterization of Embryonic Mammary Stem Cells Using Molecular Genetics and Microfluidic Sorting

DTIC Science & Technology

2008-06-01

Geoffrey M. Wahl, Ph.D. CONTRACTING ORGANIZATION: The Salk Institute for Biological Studies La Jolla, CA 92037-1099...PERFORMING ORGANIZATION REPORT NUMBER The Salk Institute for Biological Studies La Jolla, CA 92037-1099 9. SPONSORING...validated the use of a micro- volume cell sorter ( Celula , Inc.). This instrument is capable of sorting as few as 150 GFP positive cells from a sample

Determination of SPEAR-1 Rocket Body Potential during High-Voltage Experiments

DTIC Science & Technology

1990-06-01

California at San Diego La Jolla, CA 92093 10 . Dr. C. E. McIlwain Center for Astrophysics and Space Science University of California at San Diego La Jolla...Postgraduate School 39 Naval Postgraduate School 6c. ADDRESS (City, S:are, and ZIP Code) 7b. ADDRESS (Ciy, State, and ZIP Code) Monterey. CA 93943-5000...Monterey. CA 93943-5000 8a. NAME OF FUNDING.SPONSORING 80. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (If applicable

Selenium Speciation in the Fountain Creek Watershed (Colorado, USA) Correlates with Water Hardness, Ca and Mg Levels.

PubMed

Carsella, James S; Sánchez-Lombardo, Irma; Bonetti, Sandra J; Crans, Debbie C

2017-04-30

The environmental levels of selenium (Se) are regulated and strictly enforced by the Environmental Protection Agency (EPA) because of the toxicity that Se can exert at high levels. However, speciation plays an important role in the overall toxicity of Se, and only when speciation analysis has been conducted will a detailed understanding of the system be possible. In the following, we carried out the speciation analysis of the creek waters in three of the main tributaries-Upper Fountain Creek, Monument Creek and Lower Fountain Creek-located in the Fountain Creek Watershed (Colorado, USA). There are statistically significant differences between the Se, Ca and Mg, levels in each of the tributaries and seasonal swings in Se, Ca and Mg levels have been observed. There are also statistically significant differences between the Se levels when grouped by Pierre Shale type. These factors are considered when determining the forms of Se present and analyzing their chemistry using the reported thermodynamic relationships considering Ca 2+ , Mg 2+ , SeO₄ 2- , SeO₃ 2- and carbonates. This analysis demonstrated that the correlation between Se and water hardness can be explained in terms of formation of soluble CaSeO₄. The speciation analysis demonstrated that for the Fountain Creek waters, the Ca 2+ ion may be mainly responsible for the observed correlation with the Se level. Considering that the Mg 2+ level is also correlating linearly with the Se levels it is important to recognize that without Mg 2+ the Ca 2+ would be significantly reduced. The major role of Mg 2+ is thus to raise the Ca 2+ levels despite the equilibria with carbonate and other anions that would otherwise decrease Ca 2+ levels.

Defining the Role of Autophagy Kinase ULK1 Signaling in Therapeutic Response of Tuberous Sclerosis Complex to mTOR Inhibitors

DTIC Science & Technology

2016-07-01

Cancer Research ; CSHL Quantitative Symposium on Cancer; Virginia Commonwealth Cancer Biology Dept seminar; CSHL PI3K and mTOR signaling Meeting...Jolla, CA 92037 REPORT DATE: July 2016 TYPE OF REPORT: Final Report PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort...Jolla, CA 92037-1002 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) U.S. Army Medical Research and

The remarkable occurrence of large rainfall-induced debris flows at two different locations on July 12, 2008, Southern Sierra Nevada, CA, USA

USGS Publications Warehouse

DeGraff, J.V.; Wagner, D.L.; Gallegos, A.J.; DeRose, M.; Shannon, C.; Ellsworth, T.

2011-01-01

On July 12, 2008, two convective cells about 155 km apart produced a brief period of intense rainfall triggering large debris flows in the southern Sierra Nevada. The northernmost cell was centered over Oak Creek Canyon, an east-flowing drainage, and its tributaries near Independence, CA, USA. About 5:00 P.M., debris flows passed down the South Fork and North Fork of Oak Creek to merge into a large single feature whose passage affected the historic Mt. Whitney Fish hatchery and blocked California State Highway 395. At about the same time, the southernmost cell was largely centered over Erskine Creek, a main tributary of the west-flowing Kern River. Debris flows issued from several branches to coalesce into a large debris flow that passed along Erskine Creek, through the town of Lake Isabella, CA, USA and into the Kern River. It was observed reaching Lake Isabella about 6:30 P.M. Both debris flows caused significant disruption and damage to local communities. ?? 2011 Springer-Verlag.

Vertical stratification in the distribution of demersal fishes along the walls of the La Jolla and Scripps submarine canyons, California, USA

NASA Astrophysics Data System (ADS)

Smith, Joshua G.; Lindholm, James

2016-08-01

The geographic distributions of many coastal marine fish assemblages are strongly driven by habitat features, particularly among demersal fishes that live along the seafloor. Ecologists have long recognized the importance of characterizing fish habitat associations, especially where spatial management is under consideration. However, little is known about fish distributions and habitat suitability in unique demersal habitats such as submarine canyons. The active continental margin of the California coast is cut by eight submarine canyons, several of which extend from the shore to the deep abyssal plain. We sampled the demersal fish assemblages in two of those canyons: (1) the Scripps submarine canyon in the San-Diego-Scripps State Marine Conservation Area (SMCA) and (2) the La Jolla canyon in the Matlahuayl State Marine Reserve (SMR) to gain insight into both the distributions and habitat associations of demersal fishes in canyons. A remotely operated vehicle was used to conduct 21 vertically oriented transects along the canyon walls in depths ranging from 20 to 300 m. Species composition was assessed in three depth-stratified zones (100 m per zone) along the canyon walls. Species richness, abundance, and attributes of the surrounding canyon habitat structure (slope and benthic terrain ruggedness) were quantified. Three distinct assemblage groupings were identified, which comprised 35 species of demersal fishes from 17 families. Among all factors analyzed in this study, depth, slope, and ruggedness were strong explanatory variables of patterns of species richness and abundance; however, the relationship between depth and assemblage structure was non-linear. The greatest number of species was observed in the mid depth-stratified zone. These trends suggest that variation in canyon dynamics across depth strata may facilitate distinct assemblage groupings of demersal fishes, which can in turn be used to better manage these unique habitats.

Genomic and transcriptomic differences in community acquired methicillin resistant Staphylococcus aureus USA300 and USA400 strains.

PubMed

Jones, Marcus B; Montgomery, Christopher P; Boyle-Vavra, Susan; Shatzkes, Kenneth; Maybank, Rosslyn; Frank, Bryan C; Peterson, Scott N; Daum, Robert S

2014-12-19

Staphylococcus aureus is a human pathogen responsible for substantial morbidity and mortality through its ability to cause a number of human infections including bacteremia, pneumonia and soft tissue infections. Of great concern is the emergence and dissemination of methicillin-resistant Staphylococcus aureus strains (MRSA) that are resistant to nearly all β-lactams. The emergence of the USA300 MRSA genetic background among community associated S. aureus infections (CA-MRSA) in the USA was followed by the disappearance of USA400 CA-MRSA isolates. To gain a greater understanding of the potential fitness advantages and virulence capacity of S. aureus USA300 clones, we performed whole genome sequencing of 15 USA300 and 4 USA400 clinical isolates. A comparison of representative genomes of the USA300 and USA400 pulsotypes indicates a number of differences in mobile genome elements. We examined the in vitro gene expression profiles by microarray hybridization and the in vivo transcriptomes during lung infection in mice of a USA300 and a USA400 MRSA strain by performing complete genome qRT-PCR analysis. The unique presence and increased expression of 6 exotoxins in USA300 (12- to 600-fold) compared to USA400 may contribute to the increased virulence of USA300 clones. Importantly, we also observed the up-regulation of prophage genes in USA300 (compared with USA400) during mouse lung infection (including genes encoded by both prophages ΦSa2usa and ΦSa3usa), suggesting that these prophages may play an important role in vivo by contributing to the elevated virulence characteristic of the USA300 clone. We observed differences in the genetic content of USA300 and USA400 strains, as well as significant differences of in vitro and in vivo gene expression of mobile elements in a lung pneumonia model. This is the first study to document the global transcription differences between USA300 and USA400 strains during both in vitro and in vivo growth.

The Scripps Research Institute (La Jolla, CA)

DOEpatents

Schultz, Peter G.; Wang, Lei

2010-01-05

The invention provides proteins attached to solid supports, and methods of preparing such solid support-bound proteins are provided. The proteins are attached to solid supports by means of an unnatural amino acid incorporated into the protein, which unnatural amino acid includes a reactive group that can react with a second reactive group that is attached to a solid support.

Conference Eighth International Symposium on Blood Substitutes

DTIC Science & Technology

2001-04-01

Dept. of Bioengin, 0412 Japan University of California, San eishun(mn.waseda.ac.ip Diego 9500 Gilman Drive, John Frangos , Ph.D. La Jolla, CA 92093...Ph.D. La Jolla, CA 92093 Professor of Physiology and frangos @bioeng.ucsd.edu Medicine McGill University 3655 Drummond Street Montreal, Quebec, CANADA...Break 1050 1-2 Fabry 1050 V-3 Kerger 1100 1110 1-3 Manjufa P4Tsuchida 1105 V-4 Kim 1120 V-5 Kingma1130 I-4 Kramer 1130 P5 Frangos 1135 V-6 Pittman 1150

Demography and Intercontinental Spread of the USA300 Community-Acquired Methicillin-Resistant Staphylococcus aureus Lineage

PubMed Central

Glaser, Philippe; Martins-Simões, Patrícia; Villain, Adrien; Barbier, Maxime; Tristan, Anne; Bouchier, Christiane; Ma, Laurence; Bes, Michele; Laurent, Frederic; Guillemot, Didier; Wirth, Thierry

2016-01-01

ABSTRACT Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized worldwide during the 1990s; in less than a decade, several genetically distinct CA-MRSA lineages carrying Panton-Valentine leukocidin genes have emerged on every continent. Most notably, in the United States, the sequence type 18-IV (ST8-IV) clone known as USA300 has become highly prevalent, outcompeting methicillin-susceptible S. aureus (MSSA) and other MRSA strains in both community and hospital settings. CA-MRSA bacteria are much less prevalent in Europe, where the European ST80-IV European CA-MRSA clone, USA300 CA-MRSA strains, and other lineages, such as ST22-IV, coexist. The question that arises is whether the USA300 CA-MRSA present in Europe (i) was imported once or on very few occasions, followed by a broad geographic spread, anticipating an increased prevalence in the future, or (ii) derived from multiple importations with limited spreading success. In the present study, we applied whole-genome sequencing to a collection of French USA300 CA-MRSA strains responsible for sporadic cases and micro-outbreaks over the past decade and United States ST8 MSSA and MRSA isolates. Genome-wide phylogenetic analysis demonstrated that the population structure of the French isolates is the product of multiple introductions dating back to the onset of the USA300 CA-MRSA clone in North America. Coalescent-based demography of the USA300 lineage shows that a strong expansion occurred during the 1990s concomitant with the acquisition of the arginine catabolic mobile element and antibiotic resistance, followed by a sharp decline initiated around 2008, reminiscent of the rise-and-fall pattern previously observed in the ST80 lineage. A future expansion of the USA300 lineage in Europe is therefore very unlikely. PMID:26884428

Rare-earth metal prices in the USA ca. 1960 to 1994

USGS Publications Warehouse

Hedrick, James B.

1997-01-01

Rare-earth metal prices were compiled from the late 1950s and early 1960s through 1994. Although commercial demand for rare-earth metals began in 1908, as the alloy mischmetal, commercial quantities of a wide range of individual rare-earth metals were not available until the late 1950s. The discovery of a large, high-grade rare-earth deposit at Mountain Pass. CA, USA, in 1949, was significant because it led to the production of commercial quantities or rare-earth elements that reduced prices and encouraged wider application of the materials. The availability of ore from Mountain Pass, and other large rare-earth deposits, especially those in Australia and China, has provided the world with abundant resources for rare-earth metal production. This availability, coupled with improved technology from Government and private-sector metallurgical research, has resulted in substantial decreases in rare-earth metal prices since the late 1950s and early 1960s. Price series for the individual rare-earth metals (except promethium) are quoted on a kilogram basis from the late 1950s and early 1960s through 1994. Prices are given in US dollars on an actual and constant dollar basis. Industrial and economic factors affecting prices during this time period are examined.

Rare-earth metal prices in the USA ca. 1960 to 1994

USGS Publications Warehouse

Hedrick, J.B.

1997-01-01

Rare-earth metal prices were compiled from the late 1950s and early 1960s through 1994. Although commercial demand for rare-earth metals began in 1908, as the alloy mischmetal, commercial quantities of a wide range of individual rare-earth metals were not available until the late 1950s. The discovery of a large, high-grade rare-earth deposit at Mountain Pass, CA, USA, in 1949, was significant because it led to the production of commercial quantities of rare-earth elements that reduced prices and encouraged wider application of the materials. The availability of ore from Mountain Pass, and other large rare-earth deposits, especially those in Australia and China, has provided the world with abundant resources for rare-earth metal production. This availability, coupled with improved technology from Government and private-sector metallurgical research, has resulted in substantial decreases in rare-earth metal prices since the late 1950s and early 1960s. Price series for the individual rare-earth metals (except promethium) are quoted on a kilogram basis from the late 1950s and early 1960s through 1994. Prices are given in US dollars on an actual and constant dollar basis. Industrial and economic factors affecting prices during this time period are examined.

Integrating Marine Observatories into a System-of-Systems: Messaging in the US Ocean Observatories Initiative

DTIC Science & Technology

2010-06-01

Woods Hole, MA 02543, USA 3 Raytheon Intelligence and Information Systems, Aurora , CO 80011, USA 4 Scripps Institution of Oceanography, La Jolla...Amazon.com, Amazon Web Services for the Amazon Elastic Compute Cloud ( Amazon EC2). http://aws.amazon.com/ec2/. [4] M. Arrott, B. Demchak, V. Ermagan, C

agr-Dependent Interactions of Staphylococcus aureus USA300 with Human Polymorphonuclear Neutrophils

PubMed Central

Pang, Yun Yun; Schwartz, Jamie; Thoendel, Matthew; Ackermann, Laynez W.; Horswill, Alexander R.; Nauseef, William M.

2010-01-01

The emergence of serious infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has fueled interest in the contributions of specific staphylococcal virulence factors to clinical disease. To assess the contributions of agr-dependent factors to the fate of organisms in polymorphonuclear neutrophils (PMN), we examined the consequences for organism and host cells of feeding PMN with wild-type CA-MRSA (LAC) or CA-MRSA (LAC agr KO) at different multiplicities of infection (MOIs). Phagocytosed organisms rapidly increased the transcription of RNAIII in a time- and MOI-dependent fashion; extracellular USA300 (LAC) did not increase RNAIII expression despite having the capacity to respond to autoinducing peptide-enriched culture medium. HOCl-mediated damage and intracellular survival were the same in the wild-type and USA300 (LAC agr KO). PMN lysis by ingested USA300 (LAC) was time- and MOI-dependent and, at MOIs >1, required α-hemolysin (hla) as USA300 (LAC agr KO) and USA300 (LAC hla KO) promoted PMN lysis only at high MOIs. Taken together, these data demonstrate activation of the agr operon in human PMN with the subsequent production of α-hemolysin and PMN lysis. The extent to which these events in the phagosomes of human PMN contribute to the increased morbidity and mortality of infections with USA300 (LAC) merits further study. PMID:20829608

Stable isotopes, Sr/Ca, and Mg/Ca in biogenic carbonates from Petaluma Marsh, northern California, USA

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

Ingram, B.L.; De Deckker, P.; Chivas, A.R.

2004-10-19

Stable isotope ({sup 18}O/{sup 16}O and {sup 13}C/{sup 12}C) and minor-element compositions (Sr/Ca and Mg/Ca ratios) of ostracodes and gastropods separated from marsh sediments from San Francisco Bay, Northern California, were used to reconstruct paleoenvironmental changes in Petaluma Marsh over the past 700 yr. The value of {delta}{sup 18}O in the marsh carbonates reflects changes in freshwater inflow, evaporation, and temperature. Mg/Ca and Sr/Ca in ostracode calcite reflect changes in both freshwater inflow and temperature, although primarily reflect temperature changes in the salinity range of about 10-35 {per_thousand}. Ostracode {delta}{sup 18}O values show a gradual increase by 5 {per_thousand} betweenmore » 500 yr BR and the present, probably reflecting rising sea level and increased evaporation in the marsh. Superimposed on this trend are higher frequency Mg/Ca and {delta}{sup 18}O variations (3-4 {per_thousand}), probably reflecting changes in freshwater inflow and evaporation. A period of low Mg/Ca occurred between about 100-300 cal yr BP, suggesting wetter and cooler conditions during the Little Ice Age. Higher Mg/Ca ratios occurred 600-700 cal yr BP, indicating drier and warmer conditions during the end of the Medieval Warm Period. Both ostracode and gastropod {delta}{sup 13}C values decrease up-core, reflecting decomposition of marsh vegetation, which changes from C{sub 4} ({delta}{sup 13}C {approx} -12{per_thousand}) to CAM ({delta}{sup 13}C = -26 {per_thousand})-type vegetation over time.« less

Stable isotopes, Sr/Ca, and Mg/Ca in biogenic carbonates from Petaluma Marsh, northern California, USA

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

Ingram, B.L.; Deckker, P. de; Chivas, A.R.

1998-10-01

Stable isotope ({sup 18}O/{sup 16}O and {sup 13}C/{sup 12}C) and minor-element compositions (Sr/Ca and Mg/Ca ratios) of ostracodes and gastropods separated from marsh sediments from San Francisco Bay, Northern California, were used to reconstruct paleoenvironmental changes in Petaluma March over the past 700 yr. The value of {delta}{sup 18}O in the marsh carbonates reflects changes in freshwater inflow, evaporation, and temperature. Mg/Ca and Sr/Ca in ostracode calcite reflect changes in both freshwater inflow and temperature, although primarily reflect temperature changes in the salinity range of about 10--35{per_thousand}. Ostracode {delta}{sup 18}O values show a gradual increase by 5{per_thousand} between 500 yrmore » BP and the present, probably reflecting rising sea level and increased evaporation in the marsh. Superimposed on this trend are higher frequency Mg/Ca and {delta}{sup 18}O variations (3--4{per_thousand}), probably reflecting changes in freshwater inflow and evaporation. A period of low Mg/Ca occurred between about 100--300 cal yr BP, suggesting wetter and cooler conditions during the Little Ice Age. Higher Mg/Ca ratios occurred 600--700 cal yr BP, indicating drier and warmer conditions during the end of the Medieval Warm Period. Both ostracode and gastropod {delta}{sup 13}C values decrease up-core, reflecting decomposition of marsh vegetation, which changes from C{sub 4} ({delta}{sup 13}C {approximately} {minus}12{per_thousand}) to CAM ({delta}{sup 13}C = {minus}26{per_thousand})-type vegetation over time.« less

Dissemination of Methicillin-Resistant Staphylococcus aureus (MRSA), USA300 Sequence Type 8 Lineage in Latin-America

PubMed Central

Reyes, Jinnethe; Rincón, Sandra; Díaz, Lorena; Panesso, Diana; Contreras, Germán A.; Zurita, Jeannete; Carrillo, Carlos; Rizzi, Adele; Guzmán, Manuel; Adachi, Javier; Chowdhury, Shahreen; Murray, Barbara E.; Arias, Cesar A.

2009-01-01

Background Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South-America causing important clinical problems. Methods S. aureus isolates were prospectively collected (2006 to 2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing, pulsed field gel electrophoresis (PFGE), and categorized as healthcare-associated (HA)-like or CA-like clones based on genotypic characteristics and detection of genes encoding the Panton-Valentine leukocidin (PVL) and staphylococcal cassette mec (SCCmec) IV. Additionally, MLST of representative isolates of each major CA-MRSA pulsotype, and detection of USA300-associated toxins and the arcA gene were performed in all isolates categorized as CA-MRSA. Results A total of 1570 S. aureus were included; 651 were MRSA (41%), with the highest rates of MRSA isolation in Peru (62%), and lowest in Venezuela (26%) and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (GISA phenotype). The most common pulsotype (designated ComA) amongst the CA-like MRSA strains was found in 96% of isolates with the majority (81%) having ≤6 bands difference with the USA300-0114 strain. Representative isolates of this clone were ST8 but, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element (ACME)). Conclusion A variant CA-MRSA USA300 clone has now become established in South America and, in some countries, is endemic in hospital settings. PMID:19911971

Soil bacterial communities of a calcium-supplemented and a reference watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA

Treesearch

Ganapathi Sridevi; Rakesh Minocha; Swathi A. Turlapati; Katherine C. Goldfarb; Eoin L. Brodie; Louis S. Tisa; Subhash C. Minocha

2012-01-01

Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-...

Brown CA et al 2016 Dataset

EPA Pesticide Factsheets

This dataset contains the research described in the following publication:Brown, C.A., D. Sharp, and T. Mochon Collura. 2016. Effect of Climate Change on Water Temperature and Attainment of Water Temperature Criteria in the Yaquina Estuary, Oregon (USA). Estuarine, Coastal and Shelf Science. 169:136-146, doi: 10.1016/j.ecss.2015.11.006.This dataset is associated with the following publication:Brown , C., D. Sharp, and T. MochonCollura. Effect of Climate Change on Water Temperature and Attainment of Water Temperature Criteria in the Yaquina Estuary, Oregon (USA). ESTUARINE, COASTAL AND SHELF SCIENCE. Elsevier Science Ltd, New York, NY, USA, 169: 136-146, (2016).

ITER Plasma at Ion Cyclotron Frequency Domain: The Fusion Alpha Particles Diagnostics Based on the Stimulated Raman Scattering of Fast Magnetosonic Wave off High Harmonic Ion Bernstein Modes

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2014-10-01

A novel method for alpha particle diagnostics is proposed. The theory of stimulated Raman scattering, SRS, of the fast wave and ion Bernstein mode, IBM, turbulence in multi-ion species plasmas, (Stefan University Press, La Jolla, CA, 2008). is utilized for the diagnostics of fast ions, (4)He (+2), in ITER plasmas. Nonlinear Landau damping of the IBM on fast ions near the plasma edge leads to the space-time changes in the turbulence level, (inverse alpha particle channeling). The space-time monitoring of the IBM turbulence via the SRS techniques may prove efficient for the real time study of the fast ion velocity distribution function, spatial distribution, and transport. Supported by Nikola Tesla Labs., La Jolla, CA 92037.

76 FR 58471 - Endangered Species; File No. 15634

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-21

... NMFS Southwest Fisheries Science Center (SWFSC), 3333 N. Torrey Pines Ct., La Jolla, CA 92037...; weigh; flipper and passive integrated transponder tag; ultrasound; tissue, blood, cloacal swab and fat...

Life After USA300: The Rise and Fall of a Superbug

PubMed Central

2017-01-01

Abstract The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) epidemic in the United States is largely attributable to the meteoric rise of a single clone, referred to as USA300. This strain not only spread across the United States in just a few years to become the predominant cause of staphylococcal disease, but it also appears to have increased the overall number of skin and soft-tissue infections (SSTIs), increasing the overall disease burden. While USA300 still constitutes a major public health burden, its prevalence may be decreasing in some parts of the United States. Other than an epidemic in South America due to a closely related strain, USA300 also seems to have been largely unable to establish itself as an endemic infection in other geographic locations. While there have been several hypotheses put forward to explain the enormous success of USA300, the reasons for its failures and its potential fall remain obscure. Far from being unique to USA300, the rise and fall of specific clones of S. aureus in human populations seems to be a common process that has occurred multiple times and in multiple locations. This review charts the rise of USA300 and the evidence that suggests that it may be in decline, and it considers how best to understand the future spread, containment, and possible extinction of CA-MRSA. PMID:28375517

Fluid-rock interaction at the northern Hunter Mountain contact aureole, CA, USA

NASA Astrophysics Data System (ADS)

Skora, S.; Baumgartner, L.

2003-04-01

One of the world largest wollastonite deposits is located at the northern end of the Hunter Mountain Batholith, Death Valley National Park (CA, USA). The exposed Palaeozoic continental shelf sediments consist of sandy dolomites and limestones, often interbedded with chert nodules and quartzitic layers. The wollastonite was formed in the quartz-rich zones within the Mississippian Tin Mountain Limestone and the Devonian Lost Burro Formation. The sediment sequence was folded and thrusted towards the SE during the Permian/Triassic Sonoma orogeny. The folds were partly reactivated and rotated during the intrusion. A large, km-scale, anticline/syncline pair was folded and rotated from its the regional N-S trend into an E-W trend during intrusion of the Hunter Mountain Batholith and its satellite. Contact metamorphism resulted in the formation of tremolite, forsterite, and periclase in the siliceous dolomites. Tremolite, diopside and wollastonite were produced in quartz-dolomite-bearing limestones. Evidence for fluid flow is found in the intrusion and the host rocks. The periclase zone in dolomites next to the intrusion documents infiltration of a water-rich, probably magmatic, fluid. The X{CO_2} content was < 0.07 at temperatures of 640 - 700^oC. Furthermore, bodies of wollastonite ore occur well within the tremolite zone, in the northern part of a anticline. This demonstrates channelized infiltration of water-rich fluids (X{CO_2} < 0.03) and the capture of fluids in fold hinges. δD-values of 60-90 ppm (SMOW) of tremolites are consistent with the presence of magmatic water. Sets of irregularly spaced (0,2 - 2m), parallel, sub-horizontal fractures next to the wollastonite ore document fluid circulation in the cooling intrusion. Alteration zones (2-5cm) surround these fractures. Here, the kfs+cpx+pl+qtz+bt+hbl+mag igneous assemblage is changed to scp+hbl+cal+ab+ti±ep. Ti-rich, oscillatory zoned garnets partially fill these fractures. This relatively high temperature

Seismic Source Representation for Spall

DTIC Science & Technology

1990-11-21

University of California A Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William ...Arizona Los Angeles, CA 90089-0741 Tucson, AZ 85721 Prof. Christopher H. Scholz Dr. William Wortman Lamont-Doherty Geological Observatory Mission Research...Drive, Suite 1212 Stanford, CA 94305 Reston, VA 22091 Mr. William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna

Obsessive-compulsive personality disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Insomnia

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Illness anxiety disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Paranoid personality disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Avoidant personality disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Adjustment disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Dependent personality disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Antisocial personality disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Generalized anxiety disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Phobia - simple/specific

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Drug abuse

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Schizotypal personality disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic Psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Conversion disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Schizophrenia

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Agoraphobia

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Managing your depression - teens

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Panic disorder

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Personality disorders

MedlinePlus

... Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

Comparative analysis of USA300 virulence determinants in a rabbit model of skin and soft tissue infection.

PubMed

Kobayashi, Scott D; Malachowa, Natalia; Whitney, Adeline R; Braughton, Kevin R; Gardner, Donald J; Long, Dan; Bubeck Wardenburg, Juliane; Schneewind, Olaf; Otto, Michael; Deleo, Frank R

2011-09-15

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are frequently associated with strains harboring genes encoding Panton-Valentine leukocidin (PVL). The role of PVL in the success of the epidemic CA-MRSA strain USA300 remains unknown. Here we developed a skin and soft tissue infection model in rabbits to test the hypothesis that PVL contributes to USA300 pathogenesis and compare it with well-established virulence determinants: alpha-hemolysin (Hla), phenol-soluble modulin-alpha peptides (PSMα), and accessory gene regulator (Agr). The data indicate that Hla, PSMα, and Agr contribute to the pathogenesis of USA300 skin infections in rabbits, whereas a role for PVL could not be detected.

Integrated Array and 3-Component Processing Using a Seismic Microarray

DTIC Science & Technology

1991-05-31

VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological and Geophysical Sciences Vienna, VA 22180 Princeton...Station S-CUBED University of California A Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1 60 2 Prof. William ...Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission Research Corporation 8560 Cinderbed Rd. Suite # 700

Effects of a Descending Lithospheric Slab on Yield Estimates of Underground Nuclear Tests

DTIC Science & Technology

1991-02-01

Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory...90089-0741 Tucson, AZ 85721 Prof. Christopher tI. Scholz Dr. William Wortman Lamont-Doherty Geological Observatory Mission Research Corporation of...Stanford, CA 94305 Reston, VA 22091 Mr. William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division

Physical Property Measurements on Samples from an Analogue Soviet Nuclear Test Site: Northern Maine

DTIC Science & Technology

1991-04-11

A Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln...90089-0741 Tucson, AZ 85721 Prof. Christopher H. Scholz Dr. William Wortman Lamont-Doherty Geological Observatory Mission Research Corporation of...Stanford, CA 94305 Reston, VA 22091 Mr. William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division

Imaging the Morphotectonic Setting of Seismic Events and Their Propagation Paths: Methodology and Comparative Studies.

DTIC Science & Technology

1991-03-20

Suite 1212 California Institute of Technology Resron, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive...P.O. Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont-Doherty Geological Observatory Center for Earth Sciences...Cruz, CA 95064 3, Prof. Terry C. Wallace Department of Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission

Advanced Waveform Research Methods for GERESS Recordings

DTIC Science & Technology

1991-04-15

Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont-Doherty...85721 Dr. William Wortman Mission Research Corporation 8560 Cinderbed Rd. Suite # 700 Newington, VA 22122 Prof. Francis T. Wu Department of...Planetary Sciences 11800 Sunrise Valley Drive, Suite 1212 California Institute of Technology Reston, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F

Near Source Contributions to Teleseismic P Wave Coda and Regional Phases

DTIC Science & Technology

1991-04-27

Pasadena, CA 91-125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological and Geophysical Sciences Vienna, VA 22180 Princeton...Station S-CUBED University of California A Division of Maxwell Laboratory Berkeley, CA 94720 P.O.Box 1620 La Jolla, CA 92038-1620 2 Prof. William ...Geosciences- Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission Research Corporation 8560 Cinderbed Rd. Suite # 700 Newington

A Survey of Blasting Activity in the United States

DTIC Science & Technology

1991-05-16

Drive, Suite 1212 California Institute of Technology Reston, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive...Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Proi. William Menke Prof. Charles G. Sammis Lamont-Doherty Geological...of Geological Sciences 445 Pineda Court Austin, TX 78713-7909 Melbourne, FL 32940 Prof. Roy Greenfield William Kikendall Geosciences Department

High Frequency Array Studies of Long Range Lg Propagation and the Causes of Lg Blockage and Attenuation in the Eurasian Continental Craton. Volume 2

DTIC Science & Technology

1991-03-21

Drive, Suite 1212 California Institute of Technology Reston, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive...Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont-Doherty Geological Observatory Center for Earth Sciences of...Cruz, CA 95064 3 Prof. Terry C. Wallace Department of Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission

Analysis of High Frequency Seismic Data

DTIC Science & Technology

1990-10-01

Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory Lamont...Tucson, AZ 85721 Prof. Christopher H. Scholz Dr. William Wortman Lamont-Doherty Geological Observatory Mission Research Corporation of Columbia...CA 94305 Reston, VA 22091 Mr. William J. Bes, Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division of

Dignital Biological Converter

DTIC Science & Technology

2014-01-03

DARPA Contracting Officer: Michael Blackstone Submitted by: HEATHER GOUVIS Synthetic Genomics, Inc. 11149 NORTH TORREY PINES RD LA JOLLA, CA...Contracting Officer Representative (COR) Email: salit@nist.gov Michael Blackstone DARPA Contracting Officer Michael.Blackstone@darpa.mil DARPA

Soil bacterial communities of a calcium-supplemented and a reference watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA.

PubMed

Sridevi, Ganapathi; Minocha, Rakesh; Turlapati, Swathi A; Goldfarb, Katherine C; Brodie, Eoin L; Tisa, Louis S; Minocha, Subhash C

2012-03-01

Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-amended (WS1) and reference watershed (WS3) for comparison of bacterial community composition between the two watersheds. The sites were about 125 m apart and were known to have similar stream chemistry and tree populations before Ca amendment. Ca-amended soil had higher Ca and P, and lower Al and acidity as compared with the reference soils. Analysis of bacterial populations by PhyloChip revealed that the bacterial community structure in the Ca-amended and the reference soils was significantly different and that the differences were more pronounced in the mineral soils. Overall, the relative abundance of 300 taxa was significantly affected. Numbers of detectable taxa in families such as Acidobacteriaceae, Comamonadaceae, and Pseudomonadaceae were lower in the Ca-amended soils, while Flavobacteriaceae and Geobacteraceae were higher. The other functionally important groups, e.g. ammonia-oxidizing Nitrosomonadaceae, had lower numbers of taxa in the Ca-amended organic soil but higher in the mineral soil. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

Regional Studies with Broadband Data Array Analysis of Regional Pn and Pg Wavefields from the Nevada Test Site.

DTIC Science & Technology

1991-05-22

Suite 1212 California Institute of Technology Reston, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological...P.O. Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont-Doherty Geological Observatory Center for Earth Sciences of...Cruz, CA 95064 3 Prof. Terry C. Wallace Department of Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission

Clinical outcomes and treatment approach for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in Israel.

PubMed

Berla-Kerzhner, E; Biber, A; Parizade, M; Taran, D; Rahav, G; Regev-Yochay, G; Glikman, D

2017-01-01

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are increasingly documented worldwide. We recently identified two major CA-MRSA clones in Israel: USA300 and t991. Here, we assessed clinical outcomes by CA-MRSA clones and the physicians' treatment approach to CA-MRSA infections. All community-onset, clinical MRSA isolates detected during 2011-2013 by Maccabi Healthcare Services were collected and characterized phenotypically and genotypically; data were collected retrospectively from electronic medical records. Of 309 patients with MRSA infections, 64 were identified as CA-MRSA (21 %). Of the CA-MRSA infections, 72 % had skin and soft tissue infections (SSTIs), 38 % were Panton-Valentine leukocidin (PVL)+, the major clone being USA300 (n = 13, 54 %). Of PVL- isolates (n = 40, 62 %), t991 was the major clone. Age was the only predictor for PVL+ CA-MRSA infection (p < 0.001). Patients with PVL+ CA-MRSA had higher incidence of SSTI recurrences (1.061 vs. 0.647 events per patient/per year, p < 0.0001) and were more likely to have the SSTI drained (64 % vs. 21 %, p = 0.003) when compared to PVL- CA-MRSA. USA300 was more common among adults, while t991 was more common among children (p = 0.002). The physician's referral to culture results and susceptibility were the only predictors of appropriate antibiotic therapy (p < 0.001). However, only a minority of physicians referred to culture results, regardless of subspecialties. PVL+ CA-MRSA isolates caused significantly more recurrences of SSTIs and increased the need for drainage compared with PVL- isolates. Physicians' awareness of CA-MRSA as a cause of SSTIs in the community was suboptimal. Culturing of pus-producing SSTIs is crucial for providing adequate antimicrobials and elucidating MRSA epidemiology.

Greene/Feizi - U of Penn; Imperial College | Division of Cancer Prevention

Cancer.gov

Principal Investigator: Mark Greene, MD, PhDInstitution: University of Pennsylvania, Philadelphia, PA Subcontract Principal Investigator: Ten Feizi, MD, FmedSciInstitution: Imperial College London Former Principal Investigator: Minoru Fukuda, PhD (retired)Institution: Sanford Burnham Medical Research Institute, La Jolla, CA |

Cross-continental triple oxygen isotope analysis of tropospheric CO2

NASA Astrophysics Data System (ADS)

Liang, M. C.; Rangarajan, R.; Newman, S.; Laskar, A. H.

2016-12-01

The abundance variations of near surface atmospheric CO2 isotopologues (primarily 16O12C16O, 16O13C16O, 17O12C16O, and 18O12C16O) represent an integrated signal from anthropogenic/biogeochemical processes, including fossil fuel burning, biospheric photosynthesis and respiration, hydrospheric isotope exchange with water, and stratospheric photochemistry. Oxygen isotopes, in particular, are affected by the carbon and water cycles. Being a useful tracer that directly probes governing processes in CO2 biogeochemical cycles, D17O (= ln(1+d17O) - 0.516´ln(1+d18O)) provides an alternative constraint on the strengths of the associated cycles involving CO2. Here, we report more than one year of data obtained from Taiwan (Taipei), South China Sea, and USA (Pasadena, CA and Palos Verdes, CA). On average, the D17O values from these locations are similar and show no significant influence from the 2014-2016 El Nino event, in contrast to what has been reported for the 1997-1998 El Nino from the CO2 data collected from La Jolla, CA. Implications for utilizing the new tracer D17O for carbon cycling studies will be made.

Eyelid bump

MedlinePlus

... 423. Review Date 8/20/2016 Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Eyelid Disorders Read more ...

Conjunctivitis

MedlinePlus

... 22. Review Date 8/20/2016 Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Pinkeye Read more NIH ...

Annexin II Dependent Mechanism of Breast Cancer Progression

DTIC Science & Technology

2009-06-01

Sashida, T., Yoshida, M., Miyashita, T., and Nakamura, A. Treatment of advanced ovarian cancer with fibrinolytic inhibitor ( tranexamic acid ). Acta Obstet...from Calbiochem, (La Jolla, CA). Lysine–Sepharose and ε-aminocaproic acid (ε-ACA) were procured from Sigma (St. Louis, MO). Chromatography and

Enhancement of Anti-Telomerase Immunity Against Prostate Cancer

DTIC Science & Technology

2007-11-01

patients, a separate clinical trial has been designed. ATRA in capsules ( Tretinoin ) was given to patients for 7 consecutive days. After ATRA...Calbiochem (La Jolla, CA). Tetanus toxoid was purchased from List Biological Labs (Campbell, CA). ATRA ( Tretinoin ) was obtained from Roche Pharmaceuticals...patients with Tretinoin (ATRA) in combination with cancer vaccine. To evaluate whether in vivo ATRA treatment could diminish immune suppression mediated by

Some Remarks on Compliance Testing

DTIC Science & Technology

1990-09-01

Laboratory Berkeley, CA 94720 P.O. Box 1620 U I 1a Jolla, CA 92038-1620 Pr. Richard LaCoss rof, William Menke MIT-Lincoln Laboratory cesont-Doherty...Prof. Christopher H. Scholz Dr. William Wortman Lamont-Doherty Geological Observatory Mission Research Corporation of Columbia University 8560...22091 Mr. William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division of Geological & Planetary

Subconjunctival hemorrhage

MedlinePlus

... 22. Review Date 5/10/2017 Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Bleeding Read more Eye ...

Hourly mass and snow energy balance measurements from Mammoth Mountain, CA USA, 2011-2017

NASA Astrophysics Data System (ADS)

Bair, Edward H.; Davis, Robert E.; Dozier, Jeff

2018-03-01

The mass and energy balance of the snowpack govern its evolution. Direct measurement of these fluxes is essential for modeling the snowpack, yet there are few sites where all the relevant measurements are taken. Mammoth Mountain, CA USA, is home to the Cold Regions Research and Engineering Laboratory and University of California - Santa Barbara Energy Site (CUES), one of five energy balance monitoring sites in the western US. There is a ski patrol study site on Mammoth Mountain, called the Sesame Street Snow Study Plot, with automated snow and meteorological instruments where new snow is hand-weighed to measure its water content. There is also a site at Mammoth Pass with automated precipitation instruments. For this dataset, we present a clean and continuous hourly record of selected measurements from the three sites covering the 2011-2017 water years. Then, we model the snow mass balance at CUES and compare model runs to snow pillow measurements. The 2011-2017 period was marked by exceptional variability in precipitation, even for an area that has high year-to-year variability. The driest year on record, and one of the wettest years, occurred during this time period, making it ideal for studying climatic extremes. This dataset complements a previously published dataset from CUES containing a smaller subset of daily measurements. In addition to the hand-weighed SWE, novel measurements include hourly broadband snow albedo corrected for terrain and other measurement biases. This dataset is available with a digital object identifier: https://doi.org/10.21424/R4159Q.

Analysis of High Frequency Seismic Data

DTIC Science & Technology

1991-01-31

Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory Lamont-Doherty Geological...Prof. Christopher H. Scholz Dr. William Wortman Lamont-Doherty Geological Observatory Mission Research Corporation of Columbia University 735 State...94305 Reston, VA 22091 Mr. William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division of Geological

Spectral Discrimination between Explosions and Earthquakes in Central Eurasia

DTIC Science & Technology

1990-08-01

Maxwell Laboratory Chestnut Hill, MA 02167 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory Lamont...Reston, VA 22091 Mr. William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division of Geological...Planetary Sciences California Institute of Technology Pasadena, CA 91125 Dr. N. Biswas Prof. F. A. Dahlen Geophysical Institute Geological and

Testing the Consistency of Soviet Data Using a Sequence of Hypothesis Tests

DTIC Science & Technology

1990-09-01

94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory Lamont-Doherty Geological Observatory M-200B of...Scholz Dr. William Wortman Lanont-Doherty Geological Observatory Mission Research Corporation of Columbia University 8560 Cinderbed Road Palisades...Geophysics A Division of Maxwell Laboratory Stanford University 11800 Sunrise Valley Drive, Suite 1212 Stanford, CA 94305 Reston, VA 22091 Mr. William J

Scattering of Regional Pn by Moho Topography

DTIC Science & Technology

1991-02-28

1212 California Institute of Technology Reston, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological and...1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont-Doherty Geological Observatory Center for Earth Sciences of...95064 3 Prof. Terry C. Wallace Department of Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission Research

75 FR 22106 - Endangered Species; File No. 14510

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-27

... Fisheries Science Center, 3333 North Torrey Pines Court, La Jolla, CA 92037-1023, has been issued a permit...), and leatherback (Dermochelys coriacea) sea turtles for purposes of scientific research. ADDRESSES: The... of endangered and threatened species (50 CFR parts 222-226). The purpose of the proposed research...

77 FR 24686 - Endangered Species; File No. 15634

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-25

... Fisheries Science Center (SWFSC), 3333 N. Torrey Pines Ct., La Jolla, CA 92037, [Responsible Party: Lisa... purposes of scientific research. ADDRESSES: The permit and related documents are available for review upon... California, Oregon, and Washington. The purpose of the work is to identify critical forage habitats, genetic...

Targeting mechanisms of high voltage-activated Ca2+ channels.

PubMed

Herlitze, Stefan; Xie, Mian; Han, Jing; Hümmer, Alexander; Melnik-Martinez, Katya V; Moreno, Rosa L; Mark, Melanie D

2003-12-01

Functional voltage-dependent Ca2+ channel complexes are assembled by three to four subunits: alpha1, beta, alpha2delta subunits (C. Leveque et al., 1994, J. Biol Chem. 269, 6306-6312; M. W. McEnery et al., 1991, Proc. Natl. Acad. Sci. U.S.A. 88, 11095-11099) and at least in muscle cells also y subunits (B. M. Curtis and W. A. Catterall, 1984, Biochemistry 23, 2113-2118). Ca2+ channels mediate the voltage-dependent Ca2+ influx in subcellular compartments, triggering such diverse processes as neurotransmitter release, dendritic action potentials, excitation-contraction, and excitation-transcription coupling. The targeting of biophysically defined Ca2+ channel complexes to the correct subcellular structures is, thus, critical to proper cell and physiological functioning. Despite their importance, surprisingly little is known about the targeting mechanisms by which Ca2+ channel complexes are transported to their site of function. Here we summarize what we know about the targeting of Ca2+ channel complexes through the cell to the plasma membrane and subcellular structures.

Green farming systems for the Southeast USA using manure-to-energy conversion platforms

USDA-ARS?s Scientific Manuscript database

Livestock operations in the Southeastern USA are faced with implementing holistic solutions to address effective manure treatment through efficient energy management and safeguarding of supporting natural resources. By integrating waste-to-energy conversion platforms, future green farming systems ca...

The Transition to the Elastic Regime in the Vicinity of an Underground Explosion

DTIC Science & Technology

1990-11-18

of California A Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT...0741 Tucson, AZ 85721 1K (h ituphcr 11. Scholz Dr. William Wortman I a;ioi;- Ioherty G;eological Observatory Mission Research Corporation of Colurrhia... William J. Best Prof. Robert W. Clayton 907 Westwoo Drive Seismological Laboratory Vienna, VA 22180 Division of Geological & Planetary Sciences California

Propagation of Regional Seismic Phases in Western Europe

DTIC Science & Technology

1991-03-08

William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological and Geophysical Sciences Vienna, VA 22180 Princeton University Princeton, NJ 08544-0636 Dr...California A Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont...Arizona Tucson, AZ 85721 Dr. William Wortman Mission Research Corporation 8560 Cinderbed Rd. Suite # 700 Newington, VA 22122 Prof. Francis T. Wu

Studies of High-Frequency Seismic Wave Propagation.

DTIC Science & Technology

1991-03-29

William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological and Geophysical Sciences Vienna, VA 22180 Princeton University Princeton, NJ 08544...California A Division of Maxwell Laboratory Berkeley, CA 94720 P.O. Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis...University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission Research Corporation 8560 Cinderbed Rd. Suite # 700 Newington, VA 22122 Prof. Francis T. Wu

Increasing the Practical Impact of Formal Methods for Computer-Aided Software Development: Software Slicing, Merging and Integration

DTIC Science & Technology

1993-10-15

Chairs: Luqi Dave Dampier Workshop Chairman: Valdis Berzins Program Committee Chairs: Luqi Dave Dampier Program Committee: Joseph Goguen David Hislop ...Monterey, CA 93943 9500 Gilman Drive (408) 656-2461 La Jolla, CA 92093 berzins@cs.nps.navy.mil (619) 534-6898 wgg@cs.ucsd.edu A. Berztiss David Hislop ...Research Triangle Park, NC 27709-2211 Pittsburgh, Pennsylvania 15260 (919) 549-4255 (412) 624-8401 hislop @aro-emh 1 .army.mil alpha@cs.pitt.edu Jim

Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA

USGS Publications Warehouse

Brown, Shaun T.; Kennedy, B. Mack; DePaolo, Donald J.; Hurwitz, Shaul; Evans, William C.

2013-01-01

We present chemical and isotopic data for fluids, minerals and rocks from the Long Valley meteoric-hydrothermal system. The samples encompass the presumed hydrothermal upwelling zone in the west moat of the caldera, the Casa Diablo geothermal field, and a series of wells defining a nearly linear, ∼16 km long, west-to-east trend along the likely fluid flow path. Fluid samples were analyzed for the isotopes of water, Sr, and Ca, the concentrations of major cations and anions, alkalinity, and total CO2. Water isotope data conform to trends documented in earlier studies, interpreted as indicating a single hydrothermal fluid mixing with local groundwater. Sr isotopes show subtle changes along the flow path, which requires rapid fluid flow and minimal reaction between the channelized fluids and the wallrocks. Sr and O isotopes are used to calculate fracture spacing using a dual porosity model. Calculated fracture spacing and temperature data for hydrothermal fluids indicate the system is (approximately) at steady-state. Correlated variations among total CO2, and the concentration and isotopic composition of Ca suggest progressive fluid degassing (loss of CO2), which drives calcite precipitation as the fluid flows west-to-east and cools. The shifts in Ca isotopes require that calcite precipitated at temperatures of 150–180 °C is fractionated by ca. −0.3‰ to −0.5‰ relative to aqueous species. Our data are the first evidence that Ca isotopes undergo kinetic fractionation at high temperatures (>100 °C) and can be used to trace calcite precipitation along hydrothermal fluid flow paths.

REAL-TIME MEASUREMENTS OF THE CHEMICAL COMPOSITION OF SIZE-RESOLVED PARTICLES DURING A SANTA ANA WIND EPISODE, CALIFORNIA USA. (R826240)

EPA Science Inventory

Size-resolved particle composition, mass and number concentrations, aerosol scattering coefficients, and prevailing meteorological conditions were measured at the Ellen Browning Scripps Memorial Pier located in La Jolla, California on 15 December 1998. Aerosol particles were s...

Nitrogen, phosphorus, potassium, calcium, magnesium, and zinc in southeastern USA harvested flax

USDA-ARS?s Scientific Manuscript database

Flax (Linum usitatissimum L.) is a winter crop in the Southeast USA that has potential in double cropping systems. This research was conducted to provide estimates of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and zinc (Zn) removal in the harvested portions of the cro...

Mutation Analysis in Cultured Cells of Transgenic Rodents

PubMed Central

Zheng, Albert; Bates, Steven E.; Tommasi, Stella

2018-01-01

To comply with guiding principles for the ethical use of animals for experimental research, the field of mutation research has witnessed a shift of interest from large-scale in vivo animal experiments to small-sized in vitro studies. Mutation assays in cultured cells of transgenic rodents constitute, in many ways, viable alternatives to in vivo mutagenicity experiments in the corresponding animals. A variety of transgenic rodent cell culture models and mutation detection systems have been developed for mutagenicity testing of carcinogens. Of these, transgenic Big Blue® (Stratagene Corp., La Jolla, CA, USA, acquired by Agilent Technologies Inc., Santa Clara, CA, USA, BioReliance/Sigma-Aldrich Corp., Darmstadt, Germany) mouse embryonic fibroblasts and the λ Select cII Mutation Detection System have been used by many research groups to investigate the mutagenic effects of a wide range of chemical and/or physical carcinogens. Here, we review techniques and principles involved in preparation and culturing of Big Blue® mouse embryonic fibroblasts, treatment in vitro with chemical/physical agent(s) of interest, determination of the cII mutant frequency by the λ Select cII assay and establishment of the mutation spectrum by DNA sequencing. We describe various approaches for data analysis and interpretation of the results. Furthermore, we highlight representative studies in which the Big Blue® mouse cell culture model and the λ Select cII assay have been used for mutagenicity testing of diverse carcinogens. We delineate the advantages of this approach and discuss its limitations, while underscoring auxiliary methods, where applicable. PMID:29337872

Triple oxygen isotope analysis of tropospheric CO2 on the two sides of the Pacific Ocean

NASA Astrophysics Data System (ADS)

Liang, M. C.; Newman, S.; Laskar, A. H.

2017-12-01

The abundance variations of near surface atmospheric CO2 isotopologues (primarily 16O12C16O, 16O13C16O, 17O12C16O, and 18O12C16O) represent an integrated signal from anthropogenic/biogeochemical processes, including fossil fuel burning, biospheric photosynthesis and respiration, hydrospheric isotope exchange with water, stratospheric photochemistry, cross-tropopause exchange, and subsequent vertical mixing between the free troposphere and planetary boundary. Oxygen isotopes, in particular, are affected by both the carbon and water cycles. Being a useful tracer that directly probes governing processes in CO2 biogeochemical cycles, D17O (= ln(1+d17O) - 0.516 ln(1+d18O)) provides a powerful constraint on the strengths of the associated cycles involving CO2. Here, we report and compare summer to winter seasons CO2 isotopic composition from Taiwan (Taipei) and USA (Palos Verdes, CA). On average, the D17O values from Taiwan are significantly higher than those in USA. Analysis shows that the impact of 2014-2016 El Nino event on the observed D17O values is not visible, in contrast to what was reported for the 1997-1998 El Nino from the CO2 data collected from La Jolla, CA. Attempts are made to understand the elevated D17O values in the eastern Pacific compared to those in the western Pacific. Implications for utilizing the new tracer D17O along with the conventional d18O for carbon cycling studies are also discussed.

Microbial Substrate Use at Sites of Continental Serpentinization: The Tablelands, NL, CAD and the Cedars, CA, USA

NASA Astrophysics Data System (ADS)

Morrill, P. L.; Rietze, A.; Kohl, L.; Miles, S.; Kavanagh, H.; Cox, A.; Brazelton, W. J.; Ishii, S.; Sherwood Lollar, B.; Schrenk, M. O.; Nealson, K. H.; Ziegler, S. E.; Ono, S.; Wang, D. T.; Lang, S. Q.; Cumming, E.

2014-12-01

Ultra-basic reducing springs at continental sites of serpentinization act as portals into the biogeochemistry of a subsurface ultramafic environment rich in hydrogen and methane gases. Field data and results from substrate addition microcosm experiments will be presented from two contrasting continental sites of serpentinization: the Tablelands, NL, CAN and The Cedars, CA, USA both Phanerozoic in age. These continental sites share geochemical characteristics that make these environments challenging for life, such as high pH, low Eh, scarce electron acceptors, and limited dissolved inorganic carbon for autotrophic growth. However, microbiological analyses have demonstrated that life does indeed exist in these environments. While environmental genomic studies indicated the potential metabolic capabilities of microorganisms in the sites, actual microbial metabolic activities in these environments remain unknown. To expand the understanding of biogeochemistry of the sites, we are conducting studies focusing on chemical and isotopic measurements, carbon substrate utilization, energy sources, and metabolic pathways of the microorganisms. Thus far, in situ geochemical data suggests that the methane from the Tablelands is primarily non-microbial, while the methane from The Cedars likely has some microbial contributions. To date, substrate addition microcosm experiments show no microbial production of methane from Tablelands' water and sediments. However, microbial carbon monoxide utilization has been observed in Tableland microcosms, but not in The Cedars microcosms. These results demonstrate how geochemistry and substrate addition experiments can be complementary for the determination of the processes favored at these continental sites of serpentinization.

Detection of Epidemic USA300 Community-Associated Methicillin-Resistant Staphylococcus aureus Strains by Use of a Single Allele-Specific PCR Assay Targeting a Novel Polymorphism of Staphylococcus aureus pbp3

PubMed Central

Chadwick, Sean G.; Prasad, Aditya; Smith, W. Lamar; Mordechai, Eli; Adelson, Martin E.

2013-01-01

In recent years, the dramatic increase in community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections has become a significant health care challenge. Early detection of CA-MRSA is important because of its increased virulence associated with the arginine catabolic mobile element (ACME), Panton-Valentine leukocidin (PVL), and other toxins that may contribute to disease severity. In particular, the USA300 epidemic clone has emerged and now represents the cause of as much as 98% of CA-MRSA skin and soft tissue infections in the United States. Current diagnostic assays used to identify CA-MRSA strains are based on complex multiplex PCRs targeting the staphylococcal cassette chromosome mec (SCCmec) DNA junction, a multitude of genes, and noncoding DNA fragments or on a number of lengthy sequence-typing methods. Here, two nucleotide polymorphisms, G88A and G2047A, that were found to be in strict linkage disequilibrium in the S. aureus penicillin-binding protein 3 (pbp3) gene were also found to be highly associated with the USA300 clone of CA-MRSA. Clinical isolates that contained this pbp3 allele were also positive for the presence of SCCmec type IV, the ACME, and the PVL toxin gene and matched the t008 or t121 molecular spa types, which are associated specifically with the USA300 CA-MRSA clone. A single allele-specific PCR targeting the G88A polymorphism was developed and was found to be 100% sensitive and specific for the detection of USA300 CA-MRSA and 91.5% sensitive and 100% specific for the detection of all CA-MRSA isolates in this study. PMID:23698534

Elevation dependent sensitivity of northern hardwoods to Ca addition at Hubbard Brook Experimental Forest, NH USA

Treesearch

Rakesh Minocha; Stephanie Long; Palaniswamy Thangavel; Subhash C. Minocha; Christopher Eagar; Charles T. Driscoll

2010-01-01

Acidic deposition has caused a depletion of calcium (Ca) in the northeastern forest soils. Wollastonite (Ca silicate) was added to watershed 1 (WS1) at the Hubbard Brook Experimental Forest (HBEF) in 1999 to evaluate its effects on various functions of the HBEF ecosystem. The effects of Ca addition on foliar soluble (extractable in 5% HClO4) ions...

Development and Evaluation of a Monte Carlo Code System for Analysis of Ionization Chamber Responses,

DTIC Science & Technology

1987-07-01

ft. ft 3 ORNL/TM- 10196 INTERNAL DISTRIBUTION 1. F. S. Alsmiller 32. R. T. Santoro 2. R. G. Alsmiller, Jr. 33. M. S. Smith 3. D. E. Bartine 34. J. S...W. Armstrong, Science Applications, Inc., P.O. Box 2807, La Jolla, CA 92038. 57. Miguel Awschalom, National Accelerator Laboratory, P. 0. Box 500

Reservoir Changes Derived from Seismic Observations at The Geysers Geothermal Field, CA, USA

NASA Astrophysics Data System (ADS)

Gritto, R.; Jarpre, S.

2012-04-01

Induced seismicity associated with the exploitation of geothermal fields is used as a tool to characterize and delineate changes associated with injection and production of fluids from the reservoir. At the same time public concern of felt seismicity has led to objections against the operation of geothermal reservoirs in close proximity to population centers. Production at the EGS sites in Basel (Switzerland) was stopped after renewed seismicity caused concern and objection from the public in the city. Operations in other geothermal reservoirs had to be scaled back or interrupted due to an unexpected increase in seismicity (Soultz-sous-forêt, France, Berlín, El Salvador). As a consequence of these concerns and in order to optimize the use of induced seismicity for reservoir engineering purposes, it becomes imperative to understand the relationship between seismic events and stress changes in the reservoir. We will address seismicity trends at The Geysers Geothermal Reservoir, CA USA, to understand the role of historical seismicity associated with past injection of water and/or production of steam. Our analysis makes use of a comprehensive database of earthquakes and associated phase arrivals from 2004 to 2011. A high-precision sub-set of the earthquake data was selected to analyze temporal changes in seismic velocities and Vp/Vs-ratio throughout the whole reservoir. We find relatively low Vp/Vs values in 2004 suggestive of a vapor dominated reservoir. With passing time, however, the observed temporal increase in Vp/Vs, coupled with a decrease in P- and S-wave velocities suggests the presence of fluid-filled fractured rock. Considering the start of a continuous water injection project in 2004, it can be concluded that the fluid saturation of the reservoir has successfully recovered. Preliminary results of 3-D velocity inversions of seismic data appear to corroborate earlier findings that the lowest Vp/Vs estimates are observed in the center of the reservoir

Parallel Epidemics of Community-Associated Methicillin-Resistant Staphylococcus aureus USA300 Infection in North and South America.

PubMed

Planet, Paul J; Diaz, Lorena; Kolokotronis, Sergios-Orestis; Narechania, Apurva; Reyes, Jinnethe; Xing, Galen; Rincon, Sandra; Smith, Hannah; Panesso, Diana; Ryan, Chanelle; Smith, Dylan P; Guzman, Manuel; Zurita, Jeannete; Sebra, Robert; Deikus, Gintaras; Nolan, Rathel L; Tenover, Fred C; Weinstock, George M; Robinson, D Ashley; Arias, Cesar A

2015-12-15

The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) epidemic in the United States is attributed to the spread of the USA300 clone. An epidemic of CA-MRSA closely related to USA300 has occurred in northern South America (USA300 Latin-American variant, USA300-LV). Using phylogenomic analysis, we aimed to understand the relationships between these 2 epidemics. We sequenced the genomes of 51 MRSA clinical isolates collected between 1999 and 2012 from the United States, Colombia, Venezuela, and Ecuador. Phylogenetic analysis was used to infer the relationships and times since the divergence of the major clades. Phylogenetic analyses revealed 2 dominant clades that segregated by geographical region, had a putative common ancestor in 1975, and originated in 1989, in North America, and in 1985, in South America. Emergence of these parallel epidemics coincides with the independent acquisition of the arginine catabolic mobile element (ACME) in North American isolates and a novel copper and mercury resistance (COMER) mobile element in South American isolates. Our results reveal the existence of 2 parallel USA300 epidemics that shared a recent common ancestor. The simultaneous rapid dissemination of these 2 epidemic clades suggests the presence of shared, potentially convergent adaptations that enhance fitness and ability to spread. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Experimenting with Educational Games using the Xbox, PC, and iPad

NASA Astrophysics Data System (ADS)

Rohrlick, D.; Kilb, D. L.; Peach, C. L.; Simms, E.; Yang, A.; Layman, C.; Deutscher, R.

2012-12-01

Daniel Rohrlick, Alan Yang, Eric Simms, Debi Kilb, Cheryl Peach, Charina Layman, Rebecca Deutscher 1. Scripps Institution of Oceanography, La Jolla, CA, USA 2. Harvard University Center for the Environment, Cambridge, MA, USA 3. Birch Aquarium at Scripps, La Jolla, CA, USA 4. The Lawrence Hall of Science, University of California Berkeley, Berkeley, CA, USA As videogames continue to grow in popularity, especially with today's youth, it is becoming clear that gaming can be a potent learning tool. But what is the best way to engage a player in learning from a videogame? Based on our five years of developing and testing our own educational games, we experimented with various forms of gaming techniques and player interaction. Our first game, "Deep-sea Extreme Environment Pilot (DEEP)", is an Xbox 360 game where players learn about deep-sea environments while controlling a Remotely Operated Vehicle (ROV). DEEP is a "traditional" videogame where players interact with a controller and a TV screen. The second game we developed for the PC is called the "Quake Catcher Network (QCN)" game. With the gameplay focused on earth sciences, players must quickly deploy seismic sensors to record aftershocks from a large earthquake. Instead of using a game controller to play the QCN game, we instead incorporate the Microsoft Kinect motion sensor for the game input. Finally, the "Glider Game" is our third and most recent game designed for use on the mobile device platform such as iPods and iPads. In this game players control ocean gliders and must complete missions while battling ocean currents, power consumption, and other unanticipated problems. Here, the gameplay is aimed toward the casual gamer using touch-screen based controls in the hope that players can easily pick up and play this game with little gaming experience. After testing our games numerous times in museums, informal science learning centers, and classrooms we have been able to track qualitatively which educational

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System

PubMed Central

de Carvalho, Fredson Marcio Acris; Gonçalves, Leonardo Cantanhede de Oliveira; Marques, André Augusto Franco; Alves, Vanessa; Bueno, Carlos Eduardo da Silveira; De Martin, Alexandre Sigrist

2016-01-01

Objective: To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth. Methods: A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA). Results: There were no significant differences in remaining debris (P > .05) between the two groups. Conclusion: The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied. PMID:28217185

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System.

PubMed

de Carvalho, Fredson Marcio Acris; Gonçalves, Leonardo Cantanhede de Oliveira; Marques, André Augusto Franco; Alves, Vanessa; Bueno, Carlos Eduardo da Silveira; De Martin, Alexandre Sigrist

2016-01-01

To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth. A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA). There were no significant differences in remaining debris (P > .05) between the two groups. The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied.

Developing a Predictive Capability for Bioluminescence Signatures

DTIC Science & Technology

2010-01-01

sources of bioluminescence are dinoflagellates, common unicellular plankton that are also known to form red tides. Dinoflagellate bioluminescence is...wakes to locate their prey. The bioluminescence signature of a moving object depends on the bioluminescence potential of the organisms (related...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) University of California, San Diego,Scripps Institution of Oceanography,La Jolla,CA,92093-0202 8

Shock-Induced Reaction in Carbon Disulfide.

DTIC Science & Technology

1980-04-01

Tech Ctr Dept. of the Navy Attn: Dr. F. Roberto Attn: Dr. David C. Sayles Room 901 Dr. C. Merrill, Lt.S.Clift P.O. Box 1500 Washington, DC 20376 Mr. R...Sciences Attn: Dr. H. P. Marshall, Energy Center Bolling Air Force Base Dept. 52-35 Mail Code B-0l0 i Washington, DC 20332 3251 Hanover St. La Jolla, CA

Structural Basis of Merlin Tumor Suppressor Functions in Neurofibromatosis-2

DTIC Science & Technology

2013-10-01

Neurofibromatosis -2 PRINCIPAL INVESTIGATOR: Tina Izard CONTRACTING ORGANIZATION: The Scripps Research Institute La Jolla, CA 92037-1000...30September2012-29September2013 4. TITLE AND SUBTITLE Structural Basis of Merlin Tumor Suppressor Functions in Neurofibromatosis -2 5a. CONTRACT...14. ABSTRACT Loss-of-function mutations in the neurofibromatosis -2 (NF2) gene lead to familial and sporadic neurological malignancies in man

Patterns of Tinnitus and Hearing Loss Secondary to Blast Injury

DTIC Science & Technology

2017-01-01

INVESTIGATOR: Dewleen G. Baker, M.D. RECIPIENT: Veterans Medical Research Foundation San Diego, CA 92161 REPORT DATE: January 2017 TYPE OF...REPORT: Annual Report PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT...NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Veterans Medical Research Foundation 3350 La Jolla

Treating Chronic Pain after Spinal Cord Injury

DTIC Science & Technology

2016-09-01

CONTRACTING ORGANIZATION : University of California, San Diego, La Jolla, CA 92093 REPORT DATE: September 2016 TYPE OF REPORT: Annual PREPARED FOR...U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT: Approved for Public Release... ORGANIZATION NAME(S) AND ADDRESS(ES) School School of Medicine AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER University of California, San Diego

Software Aid for Optimizing 0-1 Matrices.

DTIC Science & Technology

1982-11-01

jib-Ax 1! where x = (AT"A) ’A 7~ b1s minimized, subject to the constraint that the entries of A must be O’s or I’s. Th$* problem has arisen in a...Elman University of California, San Diego Department of Linguistics La Jolla, CA 92093 1 ERIC Facility-Acquisitions 14833 Rugby Avenue Pethesda, MD

Sea Level Rise Drove Enhanced Coastal Erosion following the Last Glacial Maximum, Southern California, U.S.A.

NASA Astrophysics Data System (ADS)

Sharman, G.; Covault, J. A.; Stockli, D. F.; Sickmann, Z.; Malkowski, M. A.; Johnstone, S.

2017-12-01

Seacliff erosion poses a major threat to southern California coastal communities, including the propensity for episodic cliff failure and damage to residential and commercial property. Rising sea level is predicted to accelerate seacliff retreat, yet few constraints exist on how rapid sea level rise influenced coastal erosion rates in pre-modern timescales. Here we look to the geologic record in submarine fans to investigate changes in relative sediment supply from rivers and coastal erosion, the latter including seacliff retreat and bluffland erosion. To understand how sea level rise driven by past global warming impacted coastal erosion rates, we sampled modern rivers of the Peninsular Ranges and latest Pleistocene-Holocene submarine canyon-fan systems in southern California for detrital zircon U-Pb geochronology (1369 analyses from 10 samples). Modern river samples show a systematic north-south change in grain age populations broadly distributed across Cretaceous time (ca. 70-135 Ma) to a predominance of middle Cretaceous grain ages (ca. 95-115 Ma), reflecting variations in the geologic age of units within each river catchment. The Carlsbad and La Jolla submarine canyon-fan systems, deposited during sea level lowstand and highstand, respectively, exhibit detrital zircon age distributions consistent with derivation from upstream rivers, with mixing in the littoral zone. However, a sample from the Oceanside fan, deposited during rapid sea level rise at ca. 13 ka, is dominated by detrital ages that lack a local source in the northern Peninsular Ranges, including latest Cretaceous, late Jurassic, and Proterozoic ages. However, such grain ages are widespread in Paleogene sedimentary rocks that comprise the shelf and coastal area, suggesting increased sediment supply from coastal and shelf erosion. Assuming that the Oceanside sample is representative of sediment production during sea level rise, sediment mixing calculations suggest a one to two orders of magnitude

N-(2-Mercaptoethyl)-1,3-Propanediamine (WR-1065) Protects Thymocytes from Programed Cell Death

DTIC Science & Technology

1992-03-15

and most characteristic biohemical marker for apoptosts is calcium lontophores stimulate a suicide process in nuclear DNA fragmentation Into...1065 the dephosphory- exposed to -7-radiation. dexamethazone. or calcium lated form of WR-2721 and generally considered to be Ionophore A23187. WR...33258 fluorochrome was purchased from Calbiochem-Rehring. La Jolla, CA: Dexameth- azone and calcium lonophore A23 187 were purchased from Sigmatos

Environmental Assessment for the Construction of a Photovoltaic Solar Array at Laughlin Air Force Base, Texas

DTIC Science & Technology

2011-10-01

Alabama, 1996 Years of Experience: 24 Brian Howard. Ph.D, Quality Assurance Post Doctoral Research Associate, Burnham Institute for Medical... Research , La Jolla, CA, 1991 Post -Doctoral Research Fellow, F. Hoffmann-La Roche & Co., Basel, Switzerland, 1990 Ph.D. Toxicology, Utah State University... research any eligibility determinations, additional archeological testing or avoidance that may be warranted. Thank you for your cooperation in this state

Designing Secure Systems on Reconfigurable Hardware

DTIC Science & Technology

2008-07-01

Jeff White Department of Electrical and Computer Engineering University of California, Santa Barbara Santa Barbara, CA 93106 {nick callegari,valamehr...ece.ucsb.edu, jdwhite08@engineering.ucsb.edu Ryan Kastner Department of Computer Science and Engineering University of California, San Diego La Jolla...Transactions on Design Automation of Electronic Systems (TODAES), Vol. 13, No. 3, July 2008, 1-24 14. ABSTRACT see report 15. SUBJECT TERMS 16

Air Force Health Study. An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides. Introduction, Background and Conclusions (Chapters 1-5, 18, 19)

DTIC Science & Technology

1991-03-01

SAIC Editors: Cynthia A. Marut Ellsabeth M. Smoda SCIENCE APPLICATIONS EPIDEMIOLOGY RESEARCH DIVISION INTERNATIONAL CORPORATION ARMSTRONG LABORATORY...8400 Westpark Drive HUMAN SYSTEMS DIVISION (AFSC) McLean, VA 22102 Brooks Air Force Base, TX 78235 in con/unction WithS~DTIC SCRIPPS CLINIC & RESEARCH ...FOUNDATION, LET LA JOLLA. CA ELECTEJ•UL 011991, NATIONAL OPINION RESEARCH CENTER. CHICAGO. IL Marchl 1tO1 Introduction. Backgroend and Conclusions

Essential and toxic elements in infant foods from Spain, UK, China and USA.

PubMed

Carbonell-Barrachina, Ángel A; Ramírez-Gandolfo, Amanda; Wu, Xiangchun; Norton, Gareth J; Burló, Francisco; Deacon, Claire; Meharg, Andrew A

2012-09-01

Spanish gluten-free rice, cereals with gluten, and pureed baby foods were analysed for essential macro-elements (Ca and Na), essential trace elements (Fe, Cu, Zn, Mn, Se, Cr, Co and Ni) and non-essential trace elements (As, Pb, Cd and Hg) using ICP-MS and AAS. Baby cereals were an excellent source of most of the essential elements (Ca, Fe, Cu, Mn and Zn). Sodium content was high in pureed foods to improve their flavour; fish products were also rich in Se. USA pure baby rice samples had the highest contents of all studied essential elements, showing a different nutrient pattern compared to those of other countries. Mineral fortification was not always properly stated in the labelling of infant foods. Complementary infant foods may also contain significant amounts of contaminants. The contents of Hg and Cd were low enough to guarantee the safety of these infant foods. However, it will be necessary to identify the source and reduce the levels of Pb, Cr and As in Spanish foods. Pure baby rice samples contained too much: Pb in Spain; As in UK; As, Cr and Ni in USA; and Cr and Cd in China.

Sedimentary organic biomarkers suggest detrimental effects of PAHs on estuarine microbial biomass during the 20th century in San Francisco Bay, CA, USA

USGS Publications Warehouse

Nilsen, Elena B.; Rosenbauer, Robert J.; Fuller, Christopher C.; Jaffe, Bruce E.

2014-01-01

Hydrocarbon contaminants are ubiquitous in urban aquatic ecosystems, and the ability of some microbial strains to degrade certain polycyclic aromatic hydrocarbons (PAHs) is well established. However, detrimental effects of petroleum hydrocarbon contamination on nondegrader microbial populations and photosynthetic organisms have not often been considered. In the current study, fatty acid methyl ester (FAME) biomarkers in the sediment record were used to assess historical impacts of petroleum contamination on microbial and/or algal biomass in South San Francisco Bay, CA, USA. Profiles of saturated, branched, and monounsaturated fatty acids had similar concentrations and patterns downcore. Total PAHs in a sediment core were on average greater than 20× higher above ∼200 cm than below, which corresponds roughly to the year 1900. Isomer ratios were consistent with a predominant petroleum combustion source for PAHs. Several individual PAHs exceeded sediment quality screening values. Negative correlations between petroleum contaminants and microbial and algal biomarkers – along with high trans/cis ratios of unsaturated FA, and principle component analysis of the PAH and fatty acid records – suggest a negative impacts of petroleum contamination, appearing early in the 20th century, on microbial and/or algal ecology at the site.

Lake Tahoe Ca-Nv USA to Climate Change

NASA Astrophysics Data System (ADS)

Sahoo, G. B.; Schladow, S. G.; Reuter, J. E.; Coats, R. N.

2011-12-01

Observational studies indicate that climate at Lake Tahoe (CA-NV) basin is changing at faster rate. The impact of climate change on the lake was investigated using a suite of models and bias-corrected downscaled climate dataset generated from global circulation models. Our results indicate an increase of air temperature, a shift of snow to rainfall, a decrease of wind speed, and an onset of earlier snowmelt during the 21st Century. Combined, these changes could affect lake dynamics, ecosystems, water supply, and the winter recreational sport industry. The lake may fail to mix completely by the middle of this Century due to lake warming. Under this condition bottom dissolved oxygen would not be replenished leading to the significant release of bio-stimulatory ammonium-nitrogen and soluble phosphorus from the sediment. Both these nutrients are known to cause increased algal growth in the lake and would likely result in major changes to the lake's water quality and food web. Lake warming also increases water loss through evaporation, resulting in less available water for downstream domestic supply, agriculture, and recreation. Population growth and increased human demand for water will compound severity of problems in water quantity and quality. Thus, watershed planning and management should assess vulnerability to climatic variations through the application of basin-wide hydro-climatology, watershed soils, and lake response models to (1) improve drought, flood, and forest-fire forecasting, (2) assess hydrological trends, (3) estimate the potential effects of climate change on surface runoff and pollutant loads, and (4) evaluate response from various adaptation strategies.

A multi-proxy palaeoecological and palaeoclimatic record within full glacial lacustrine deposits, western Tennessee, USA

USGS Publications Warehouse

Grimley, D.A.; Daniel, L.; Kaplan, S.W.; Yansa, C.H.; Curry, B. Brandon; Oches, E.A.

2009-01-01

The Fulton Section, along the Mississippi River in western Tennessee, USA, is a 1km continuous exposure (~20m vertically) of Quaternary fluvial and lacustrine deposits, inset within Eocene sediments and buried by thick loess. Fossiliferous slackwater lake sediments record maximum aggradation during the last two major glaciations, with deposition between ca. 190-140 ka and 24-1814C ka BP, based on amino acid and radiocarbon chronology, respectively. During the onset of full glacial conditions (ca. 24-22 14C ka BP), a relatively permanent shallow lake environment is indicated by ostracods, aquatic molluscs, and both pollen and macrofossils of aquatic plants. By 21.8 14C ka BP, increasing emergent plants, amphibious gastropods (Pomatiopsis) and heavier ??18O compositions suggest marsh-like conditions in a periodically drying lake. The surrounding uplands consisted of Picea-Pinus woodlands mixed with cool-temperate hardwoods (e.g. Quercus, Populus, Carya), grasses and herbs. More open conditions ensued ca. 20 14C ka BP, with loess and slopewash gradually infilling the former lake by 18 14C ka BP. Modern analogue analyses of ostracods and palaeontological evidence imply a full glacial climate similar to today's mixed-boreal zone in central Minnesota, USA, about 98C cooler in mean annual temperature than present-day western Tennessee. Copyright ?? 2009 John Wiley & Sons, Ltd.

Role of PknB kinase in antibiotic resistance and virulence in community-acquired methicillin-resistant Staphylococcus aureus strain USA300.

PubMed

Tamber, Sandeep; Schwartzman, Joseph; Cheung, Ambrose L

2010-08-01

The regulation of cellular processes by eukaryote-like serine/threonine kinases is widespread in bacteria. In the last 2 years, several studies have examined the role of serine/threonine kinases in Staphylococcus aureus on cell wall metabolism, autolysis, and virulence, mostly in S. aureus laboratory isolates in the 8325-4 lineage. In this study, we showed that the pknB gene (also called stk1) of methicillin-resistant S. aureus (MRSA) strain COL and the community-acquired MRSA (CA-MRSA) strain USA300 is involved in cell wall metabolism, with the pknB mutant exhibiting enhanced sensitivity to beta-lactam antibiotics but not to other classes of antibiotics, including aminoglycosides, ciprofloxacin, bactrim, and other types of cell wall-active agents (e.g., vancomycin and bacitracin). Additionally, the pknB mutant of USA300 was found to be more resistant to Triton X-100-induced autolysis and also to lysis by lysostaphin. We also showed that pknB is a positive regulator of sigB activity, resulting in compromise in its response to heat and oxidative stresses. In association with reduced sigB activity, the expression levels of RNAII and RNAIII of agr and the downstream effector hla are upregulated while spa expression is downmodulated in the pknB mutant compared to the level in the parent. Consistent with an enhanced agr response in vitro, virulence studies of the pknB mutant of USA300 in a murine cutaneous model of infection showed that the mutant was more virulent than the parental strain. Collectively, our results have linked the pknB gene in CA-MRSA to antibiotic resistance, sigB activity, and virulence and have highlighted important differences in pknB phenotypes (virulence and sigB activity) between laboratory isolates and the prototypic CA-MRSA strain USA300.

Long-Term Changes in Calcium (Ca) Sources in Base-Poor Forest Ecosystem: Insight from Stable Ca-Isotopes in Tree Rings

NASA Astrophysics Data System (ADS)

Farkas, J.; Dejeant, A.; Orwig, D.; Jacobsen, S. B.

2009-12-01

Calcium (Ca) is an essential nutrient in higher plants and also a major base-cation predicted to be most affected by environmental perturbations such as acid rain deposition and/or excessive biomass harvesting. Therefore, a better understanding of the Ca cycling in terrestrial environment is of primary interest and critical for the sustainable forest management. The aim of this project was to investigate the use of Ca isotopes as a tracer of the forest Ca cycle and its evolution through time. Here we present stable Ca isotope composition (δ44/40Ca and δ44/42Ca) and elemental concentrations of a 260-year record of tree-rings from Red Oak (Quercus rubra). The core sample was collected at an undisturbed old-growth forest site in southern New England (Wachusett Mountain, MA, USA) developed on granitic bedrock. The associated soils (sandy loams) are thus naturally base-poor and sensitive to the loss of Ca due to increased acid rain deposition and/or excessive biological uptake. The δ44/40Ca (NIST) record of decadal tree-ring increments shows a general declining trend from -0.35 to -0.80 ±0.1 per mil (from year 1750 to 2000). Superimposed on this long-term δ44/40Ca trend is a systematic negative excursion with a minimum of -0.95 ±0.1 per mil dated between 1870 and 1950. Overall, the long-term δ44/40Ca record shows statistically significant correlation with Ca/Sr ratios (R2 = 0.87, p < .01) as well as Na/Ca data (R2 = 0.69, p < .01). The fact that δ44/40Ca correlates also with Na/Ca suggest that the observed Ca isotope variations are likely related to changes in soil-Ca sources rather than being a consequence of biological processes within the tree. This is because the sodium budget of trees and forests is primarily controlled by silicate weathering rates derived from the dissolution of Na-rich minerals such as plagioclase and/or K-feldspar. Nevertheless, the role of biological processes on tree-ring δ44/40Ca record will be tested independently via measurements

Gene Targets in Prostate Tumor Cells that Mediate Aberrant Growth and Invasiveness

DTIC Science & Technology

2005-02-01

Craig A. Hauser , Ph.D. Gabriele Foos, Ph.D. CONTRACTING ORGANIZATION: The Burnham Institute La Jolla, California 92037 REPORT DATE: February 2005 TYPE...NUMBERS Gene Targets in Prostate Tumor Cells that Mediate DAMD17-02-1-0019 Aberrant Growth and Invasiveness 6. AUTHOR(S) Craig A. Hauser , Ph.D. Gabriele...REPORTABLE OUTCOMES Foos G, Hauser CA (2004) The role of Ets transcription factors in mediating cellular transformation. In: Handbook of Experimental

Distribution, Abundance and Population Structuring of Beaked Whales in the Great Bahama Canyon, Northern Bahamas

DTIC Science & Technology

2012-01-01

Torrey Pines Court La Jolla, CA 92037 Award Number: N0001409IP20051 Gina Ylitalo & David Herman, Ph.D. NOAA Northwest Fisheries Science Center...located in the northern Bahamas (b). From the northwest Atlantic Ocean, the canyon has two branches; northwards into Northwest Providence Channel where...conducted by Dr. David Herman and his colleagues at the Environmental Assessment Program at NOAA’s Northwest Fisheries Science Center (under guidance

Distribution, Abundance and Population Structuring of Beaked Wales in the Great Bahama Canyon, Northern Bahamas

DTIC Science & Technology

2012-09-02

Lennard and M.M. Krahn (2005) Feeding ecology of North Pacific killer whales Orcinus orca from fatty acid, stable isotope, and organochlorine...Center 3333 N. Torrey Pines Court La Jolla, CA 92037 Award Number: N0001409IP20051 Gina Ylitalo David Herman, Ph.D. Northwest Fisheries Science...Atlantic Ocean \\ Figure 1. The Great Bahama Canyon (a) is a large submarine canyon located in the northern Bahamas (b). From the northwest Atlantic

Spectral Studies of the Elastic Wave Radiation from Appalachian Earthquakes and Explosions-Explosion Source Spectra Modeling Using Blaster’s Logs

DTIC Science & Technology

1991-09-01

William J. Best Prof. F. A. Dahlen 907 Westwood Drive Geological and Geophysical Sciences Vienna, VA 22180 Princeton University Princeton, NJ 08544...Laboratory 2 Taft Court, Suite 203 P.O. Box 1620 Rockville, MD 20850 La Jolla, CA 92038-1620 Prof. William Menke Prof. Paul G. Richards Lamont-Doherty...Wallace Departm_-ent of Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission Research Corporation 8560 Cinderbed

Conference: Three Decades of Numerical Linear Algebra at Berkeley

DTIC Science & Technology

1993-04-30

copies, to ONR as, requested. "j;r 8y......... ....-... AV 2 Ti;tles.txt JTTLAA E TCAL ISSUE DEDICATED TO PARLETT AND KAH.’N AUTHORS TITLE (1) De= el ...and Total Least Squares Ricardo D. Fierro and James R. Bunch Department of Mathematics University of California, San Diego La Jolla, CA 92093...Electrical En $ineering, Katholieke Universiteit Leuven, 3001 Heterlec, Belgium. HAESUN PARK Computer Science Department, University of Minesoa

Secretary of the Navy Professor of Oceanography

DTIC Science & Technology

2013-11-18

of better predicting polar ice melting processes and the associated global rise in sea level. 15. SUBJECT TERMS Wind-drag, ocean surface roughness...Ross Sea with the goal of better predicting polar ice melting processes and the associated global rise in sea level. PUBLICATIONS Farrell, W. and W...Oceanography, LaJolla, CA; 12 May 2011 Attended: International Symposium on Interactions of Glaciers and Ice Sheets with the Ocean SIO, Scripps Institution

Genomic Physics. Multiple Laser Beam Treatment of Alzheimer's Disease

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2014-03-01

The synapses affected by Alzheimer's disease can be rejuvenated by the multiple ultrashort wavelength laser beams.[2] The guiding lasers scan the whole area to detect the amyloid plaques based on the laser scattering technique. The scanning lasers pinpoint the areas with plaques and eliminate them. Laser interaction is highly efficient, because of the focusing capabilities and possibility for the identification of the damaging proteins by matching the protein oscillation eigen-frequency with laser frequency.[3] Supported by Nikola Tesla Labs, La Jolla, California, USA.

Modelling middle pliocene warm climates of the USA

USGS Publications Warehouse

Haywood, A.M.; Valdes, P.J.; Sellwood, B.W.; Kaplan, J.O.; Dowsett, H.J.

2001-01-01

The middle Pliocene warm period represents a unique time slice in which to model and understand climatic processes operating under a warm climatic regime. Palaeoclimatic model simulations, focussed on the United States of America (USA), for the middle Pliocene (ca 3 Ma) were generated using the USGS PRISM2 2?? ?? 2?? data set of boundary conditions and the UK Meteorological Office's HadAMS General Circulation Model (GCM). Model results suggest that conditions in the USA during the middle Pliocene can be characterised as annually warmer (by 2?? to 4??C), less seasonal, wetter (by a maximum of 4 to 8 mm/day) and with an absence of freezing winters over the central and southern Great Plains. A sensitivity experiment suggests that the main forcing mechanisms for surface temperature changes in near coastal areas are the imposed Pliocene sea surface temperatures (SST's). In interior regions, reduced Northern Hemisphere terrestrial ice, combined with less snow cover and a reduction in the elevation of the western cordillera of North America, generate atmospheric circulation changes and positive albedo feedbacks that raise surface temperatures. A complex set of climatic feedback mechanisms cause an enhancement of the hydrological cycle magnifying the moisture bearing westerly wind belt during the winter season (Dec., Jan., Feb.). Predictions produced by the model are in broad agreement with available geological evidence. However, the GCM appears to underestimate precipitation levels in the interior and central regions of the southern USA. Copyright: Palaeontological Association, 22 June 2001.

Risk of Skin and Soft Tissue Infections among Children Found to be Staphylococcus aureus MRSA USA300 Carriers

PubMed Central

Immergluck, Lilly Cheng; Jain, Shabnam; Ray, Susan M.; Mayberry, Robert; Satola, Sarah; Parker, Trisha Chan; Yuan, Keming; Mohammed, Anaam; Jerris, Robert C.

2017-01-01

Introduction The purpose of this study was to examine community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) carriage and infections and determine risk factors associated specifically with MRSA USA300. Methods We conducted a case control study in a pediatric emergency department. Nasal and axillary swabs were collected, and participants were interviewed for risk factors. The primary outcome was the proportion of S. aureus carriers among those presenting with and without a skin and soft tissue infection (SSTI). We further categorized S. aureus carriers into MRSA USA300 carriers or non-MRSA USA300 carriers. Results We found the MRSA USA300 carriage rate was higher in children less than two years of age, those with an SSTI, children with recent antibiotic use, and those with a family history of SSTI. MRSA USA300 carriers were also more likely to have lower income compared to non-MRSA USA300 carriers and no S. aureus carriers. Rates of Panton-Valentine leukocidin (PVL) genes were higher in MRSA carriage isolates with an SSTI, compared to MRSA carriage isolates of patients without an SSTI. There was an association between MRSA USA300 carriage and presence of PVL in those diagnosed with an abscess. Conclusion Children younger than two years were at highest risk for MRSA USA300 carriage. Lower income, recent antibiotic use, and previous or family history of SSTI were risk factors for MRSA USA300 carriage. There is a high association between MRSA USA300 nasal/axillary carriage and presence of PVL in those with abscesses. PMID:28210352

Pure Electron Plasmas near Thermal Equilibrium

DTIC Science & Technology

1990-11-01

I University of California, San Diego Institute of Pure and Applied Physical Sciences La Jolla, CA 92093 N 0 (V) Final Technical Report N "Pure...Research/code -..... " 1112AI. VC 1/8/91 ’ , .... i ; () -ii- r INTRODUCTION Since 1982 the plasma group at UCSD has been conducting an experimental and...scale. We have also observed an unusual I = 1 instability which the previously published theoretical literature stated unconditionally was stable. The

Application of Regional Arrays in Seismic Verification Research

DTIC Science & Technology

1990-08-31

Hill, MA 02167 P.O. Box 1620 La Jolla, CA 92038-1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory L amront-Doherty -- dogical b ser t...LWH of Columbia University Hanscom AFB, MA 01731-5000 Palisades, NY 10964 3 Dr. Lorraine Wolf GLILWH Hanscom AFB, MA 01731-5000 Dr. William Wortman... William J. Best Prof. Robert W. Clayton 907 Westwood Drive Seismological Laboratory Vienna, VA 22180 Division of Geological & Planetary Sciences

Integrating Observations of the Boundary Current Flow around Sri Lanka

DTIC Science & Technology

2015-09-30

around Sri Lanka Uwe Send and Matthias Lankhorst Scripps Institution of Oceanography 9500 Gilman Drive, Mail Code 0230 La Jolla, CA 92093-0230...of Bengal. For this, the flow around Sri Lanka is critical since it exchanges salt and freshwater between the Bay of Bengal and the Arabian Sea...OBJECTIVES In-situ continuous observations of the boundary current flow around Sri Lanka will be collected over a period of several years. In order

Comparison of the Frequency Response and Voltage Tuning Characteristics of a FFP and a MEMS Fiber Optic Tunable Filter

DTIC Science & Technology

2004-05-12

Structural Engineering, La Jolla, CA 92093 14. ABSTRACT Tunable optical filters based on a Fabry - Perot element are a critical component in many...wavelength based fiber optic sensor systems. This report compares the performance of two fiber-pigtailed tunable optical filters, the fiber Fabry - Perot (FFP...both filters suggests that they can operate at frequencies up to 20 kHz and possibly as high as 100 kHz. 15. SUBJECT TERMS Tunable Fabry - Perot filters

The Ca2+/Calmodulin/CaMKK2 Axis: Nature’s Metabolic CaMshaft

PubMed Central

Marcelo, Kathrina L.; Means, Anthony R.; York, Brian

2016-01-01

Calcium (Ca2+) is an essential ligand that binds its primary intracellular receptor Calmodulin (CaM) to trigger a variety of downstream processes and pathways. Central to the actions of Ca2+/CaM is the activation of a highly conserved Ca2+/CaM kinase (CaMK) cascade, which amplifies Ca2+ signals through a series of subsequent phosphorylation events. Proper regulation of Ca2+ flux is necessary for whole-body metabolism and disruption of Ca2+ homeostasis has been linked to a variety of metabolic diseases. Herein, we provide a synthesis of recent advances that highlight the roles of the Ca2+/CaM kinase axis in key metabolic tissues. An appreciation of this information is critical in order to understand the mechanisms by which Ca2+/CaM-dependent signaling contributes to metabolic homeostasis and disease. PMID:27449752

Metastasis Research Society VII International Congress (Part II). 7-10 October 1998, San Diego, CA, USA.

PubMed

Chambers, A F

1999-02-01

The Metastasis Research Society (MRS) has held its International Congress every two years since 1986, and alternates between European and North American meeting venues. The next MRS International Congress will be held in London, UK in the year 2000, and will be hosted by the current MRS President, Dr. Suzanne Eccles (Institute of Cancer Research, Sutton, UK). Dr. Eccles took over from the out-going President, Dr. William Stetler-Stevenson (National Institutes of Health, Bethesda, MD, USA), at the San Diego meeting. Information on joining the Metastasis Research Society, which includes a subscription to the Society's journal, Clinical and Experimental Metastasis, can be obtained from Dr. Eccles (suzan@icr.ac.uk) or from the newly-elected Secretary/Treasurer Dr. Danny Welch (Hershey, PA, USA; drw9@psu.edu). The meeting was organized by Darwin Medical Communications Ltd (Gill Heaton, Oxford, UK), who have placed the full program on the meeting web site (http:@www.sparks.co.uk/mrs). It is envisaged that full abstracts of all the presentations will be placed on the Metastasis Research Society web site, which is currently under construction. Corporate sponsors for the San Diego meeting included Agouron Pharmaceuticals, Becton Dickinson & Co, Zeneca Pharma SA, Schering AG, AntiCancer Inc, Oncogene Research Products, Daiichi Seiyaku Co Ltd and Novartis Pharma AG.

Demography and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon along the open coast of southern California, USA

USGS Publications Warehouse

Nosal, D.C.; Cartamil, D.C.; Long, J.W.; Luhrmann, M.; Wegner, N.C.; Graham, J.B.

2013-01-01

The demography, spatial distribution, and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon in La Jolla, California, USA, were investigated to resolve the causal explanations for this and similar shark aggregations. All sharks sampled from the aggregation site (n=140) were sexually mature and 97.1 % were female. Aerial photographs taken during tethered balloon surveys revealed high densities of milling sharks of up to 5470 sharks ha-1. Eight sharks were each tagged with a continuous acoustic transmitter and manually tracked without interruption for up to 48 h. Sharks exhibited strong site-fidelity and were generally confined to a divergence (shadow) zone of low wave energy, which results from wave refraction over the steep bathymetric contours of the submarine canyon. Within this divergence zone, the movements of sharks were strongly localized over the seismically active Rose Canyon Fault. Tracked sharks spent most of their time in shallow water (≤2 m for 71.0 % and ≤10 m for 95.9 % of time), with some dispersing to deeper (max: 53.9 m) and cooler (min: 12.7 °C) water after sunset, subsequently returning by sunrise. These findings suggest multiple functions of this aggregation and that the mechanism controlling its formation, maintenance, and dissolution is complex and rooted in the sharks' variable response to numerous confounding environmental factors.

Recognizing loss of open forest ecosystems by tree densification and land use intensification in the Midwestern USA

Treesearch

Brice B. Hanberry; Marc D. Abrams

2018-01-01

Forests and grasslands have changed during the past 200 years in the eastern USA, and it is now possible to quantify loss and conversion of vegetation cover at regional scales. We quantified historical (ca. 1786-1908) and current land cover and determined long-term ecosystem change to either land use or closed forests in eight states of the Great Lakes and Midwest....

Seismic Surveillance. Nuclear Test Ban Verification

DTIC Science & Technology

1990-02-26

e.g., see Matthews and Cheadle, 1986). To summarize, data processing tied to 8 msec sampling is a bit coarse for the sedimentary column but...Continental Extensional Tectonics. Geological Society Special Publication No. 28, 53-65. Matthews , D.H. and Cheadle, M.J. 1986: Deep Reflections from the...Laboratory P. 0. Box 73 P.O. Box 1620 Lexington, MA 02173-0073 (3 copies) La Jolla, CA 92038-1620 Prof Fred K. Lamb Prof. William Menke University of

Measurements of Aerosol Size Distributions in the Lower Troposphere over Northern Europe.

DTIC Science & Technology

1981-06-01

ADAG 7 SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA VISA--ETC F/6 4/ 1 MEASUREMENTS OF AEROSOL SIZE DISTRIBUTIONS IN THE LOWER TROPOSP--ETC(U) JUN... 1 I"’Zt J~ 9 PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK University of California, San Diego ARA 62101F 7...AIR FORCE HANSCOM AFB, MASSACHUSETTS 0 1731 k i J 1 Summary Airborne measurements of particle size distributions were made at several altitudes within

EphB4 Receptor Tyrosine Kinase in Prostate Cancer

DTIC Science & Technology

2011-09-01

San Diego, La Jolla, CA, USAAbbreviations: MAP kinase, mitogen-activated prote tidylinositol 4,5-bisphosphate; PI(3,4,5)P3, phosphatid PI3K...okadaic acid (MP Biomedicals, 150 μM stock in DMSO), LY294002, PD98059, rapamycin (see previous section), dasatinib (LC Laboratories; 50 μM stock in DMSO...the phosphatase inhibitor tautomycin, which preferentially inhibits PP1 over PP2A. The cells were stimulated and analyzed as in (D). (F) Okadaic acid

Multi-species coral Sr/Ca-based sea-surface temperature reconstruction using Orbicella faveolata and Siderastrea siderea from the Florida Straits

USGS Publications Warehouse

Flannery, Jennifer A.; Richey, Julie N.; Thirumalai, Kaustubh; Poore, Richard Z.; DeLong, Kristine L.

2017-01-01

We present new, monthly-resolved Sr/Ca-based sea-surface temperature (SST) records from two species of massive coral, Orbicella faveolata and Siderastrea siderea, from the Dry Tortugas National Park, FL, USA (DTNP). We combine these new records with published data from three additional S. siderea coral colonies to generate a 278-year long multi-species stacked Sr/Ca-SST record from DTNP. The composite record of mean annual Sr/Ca-SST at DTNP shows pronounced decadal-scale variability with a range of 1 to 2°C. Notable cool intervals in the Sr/Ca-derived SST lasting about a decade centered at ~1845, ~1935, and ~1965 are associated with reduced summer Sr/Ca-SST (monthly maxima < 29°C), and imply a reduction in the spatial extent of the Atlantic Warm Pool (AWP). There is significant coherence between the composite DTNP Sr/Ca-SST record and the Atlantic Multidecadal Oscillation (AMO) index, with the AMO lagging Sr/Ca-SST at DTNP by 9 years. Low frequency variability in the Gulf Stream surface transport, which originates near DTNP, may provide a link for the lagged relationship between multidecadal variability at DTNP and the AMO.

AMP-activated protein kinase-mediated feedback phosphorylation controls the Ca2+/calmodulin (CaM) dependence of Ca2+/CaM-dependent protein kinase kinase β.

PubMed

Nakanishi, Akihiro; Hatano, Naoya; Fujiwara, Yuya; Sha'ri, Arian; Takabatake, Shota; Akano, Hiroki; Kanayama, Naoki; Magari, Masaki; Nozaki, Naohito; Tokumitsu, Hiroshi

2017-12-01

The Ca 2+ /calmodulin-dependent protein kinase kinase β (CaMKKβ)/5'-AMP-activated protein kinase (AMPK) phosphorylation cascade affects various Ca 2+ -dependent metabolic pathways and cancer growth. Unlike recombinant CaMKKβ that exhibits higher basal activity (autonomous activity), activation of the CaMKKβ/AMPK signaling pathway requires increased intracellular Ca 2+ concentrations. Moreover, the Ca 2+ /CaM dependence of CaMKKβ appears to arise from multiple phosphorylation events, including autophosphorylation and activities furnished by other protein kinases. However, the effects of proximal downstream kinases on CaMKKβ activity have not yet been evaluated. Here, we demonstrate feedback phosphorylation of CaMKKβ at multiple residues by CaMKKβ-activated AMPK in addition to autophosphorylation in vitro , leading to reduced autonomous, but not Ca 2+ /CaM-activated, CaMKKβ activity. MS analysis and site-directed mutagenesis of AMPK phosphorylation sites in CaMKKβ indicated that Thr 144 phosphorylation by activated AMPK converts CaMKKβ into a Ca 2+ /CaM-dependent enzyme as shown by completely Ca 2+ /CaM-dependent CaMKK activity of a phosphomimetic T144E CaMKKβ mutant. CaMKKβ mutant analysis indicated that the C-terminal domain (residues 471-587), including the autoinhibitory region, plays an important role in stabilizing an inactive conformation in a Thr 144 phosphorylation-dependent manner. Furthermore, immunoblot analysis with anti-phospho-Thr 144 antibody revealed phosphorylation of Thr 144 in CaMKKβ in transfected COS-7 cells that was further enhanced by exogenous expression of AMPKα. These results indicate that AMPK-mediated feedback phosphorylation of CaMKKβ regulates the CaMKKβ/AMPK signaling cascade and may be physiologically important for intracellular maintenance of Ca 2+ -dependent AMPK activation by CaMKKβ. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

γCaMKII shuttles Ca2+/CaM to the nucleus to trigger CREB phosphorylation and gene expression

PubMed Central

Ma, Huan; Groth, Rachel D.; Cohen, Samuel M.; Emery, John F.; Li, Bo-Xing; Hoedt, Esthelle; Zhang, Guo-An; Neubert, Thomas A.; Tsien, Richard W.

2014-01-01

SUMMARY Activity-dependent CREB phosphorylation and gene expression are critical for long-term neuronal plasticity. Local signaling at CaV1 channels triggers these events but how information is relayed onward to the nucleus remains unclear. Here we report a novel mechanism that mediates long-distance communication within cells: a shuttle that transports Ca2+/calmodulin from the surface membrane to the nucleus. We show that the shuttle protein is γCaMKII, that its phosphorylation at Thr287 by βCaMKII protects the Ca2+/CaM signal, and that CaN triggers its nuclear translocation. Both βCaMKII and CaN act in close proximity to CaV1 channels, supporting their dominance, while γCaMKII operates as a carrier, not as a kinase. Upon arrival within the nucleus, Ca2+/CaM activates CaMKK and its substrate CaMKIV, the CREB kinase. This mechanism resolves longstanding puzzles about CaM/CaMK-dependent signaling to the nucleus. The significance of the mechanism is emphasized by dysregulation of CaV1, γCaMKII, βCaMKII and CaN in multiple neuropsychiatric disorders. PMID:25303525

Mitochondrial Ca2+ homeostasis during Ca2+ influx and Ca2+ release in gastric myocytes from Bufo marinus

PubMed Central

Drummond, Robert M; Mix, T Christian H; Tuft, Richard A; Walsh, John V; Fay, Fredric S

2000-01-01

The Ca2+-sensitive fluorescent indicator rhod-2 was used to monitor mitochondrial Ca2+ concentration ([Ca2+]m) in gastric smooth muscle cells from Bufo marinus. In some studies, fura-2 was used in combination with rhod-2, allowing simultaneous measurement of cytoplasmic Ca2+ concentration ([Ca2+]i) and [Ca2+]m, respectively. During a short train of depolarizations, which causes Ca2+ influx from the extracellular medium, there was an increase in both [Ca2+]i and [Ca2+]m. The half-time (t½) to peak for the increase in [Ca2+]m was considerably longer than the t½ to peak for the increase in [Ca2+]i. [Ca2+]m remained elevated for tens of seconds after [Ca2+]i had returned to its resting value. Stimulation with caffeine, which causes release of Ca2+ from the sarcoplasmic reticulum (SR), also produced increases in both [Ca2+]i and [Ca2+]m. The values of t½ to peak for the increase in [Ca2+] in both cytoplasm and mitochondria were similar; however, [Ca2+]i returned to baseline values much faster than [Ca2+]m. Using a wide-field digital imaging microscope, changes in [Ca2+]m were monitored within individual mitochondria in situ, during stimulation of Ca2+ influx or Ca2+ release from the SR. Mitochondrial Ca2+ uptake during depolarizing stimulation caused depolarization of the mitochondrial membrane potential. The mitochondrial membrane potential recovered considerably faster than the recovery of [Ca2+]m. This study shows that Ca2+ influx from the extracellular medium and Ca2+ release from the SR are capable of increasing [Ca2+]m in smooth muscle cells. The efflux of Ca2+ from the mitochondria is a slow process and appears to be dependent upon the amount of Ca2+ in the SR. PMID:10713963

Acetylcholine Receptors in Model Membranes: Structure/Function Correlates.

DTIC Science & Technology

1985-12-01

8217-ASSIFICAT1CN’r.OlrNC7-..OINC 6. 04STPl3U7lCh STATE)III (a. -,41. Revlon) Approved for public release;, distribution unlimited D T 18. SUPPLENENTARY NOTES *Annual...of California, San Diego B-019 La Jolla, California 92093 Approved for public release; distribution unlimited The findings in this report are not to be...electrodes E-255 and E 206 (In Vivo Metric Systems Metric Systems, Healdsburg, CA). DC source ( Omnical 2001, WPI Instruments, New Haven, CT). RACAL

A Devil in the Details: Matrix-Dependent 40Ca42Ca++/42Ca+ and Its Effects on Estimates of the Initial 41Ca/40Ca in the Solar System

NASA Astrophysics Data System (ADS)

McKeegan, K. D.; Liu, M.-C.

2015-07-01

Ian Hutcheon established that the molecular ion interference 40Ca42Ca++/42Ca+ on 41K+ is strongly dependent on the mineral analyzed. Correction for this "matrix effect" led to a downward revision of the initial 41Ca/40Ca of the solar system.

EPICS controlled sample mounting robots at the GM/CA CAT.

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

Makarov, O. A.; Benn, R.; Corcoran, S.

2007-11-11

GM/CA CAT at Sector 23 of the advanced photon source (APS) is an NIH funded facility for crystallographic structure determination of biological macromolecules by X-ray diffraction [R.F. Fischetti, et al., GM/CA canted undulator beamlines for protein crystallography, Acta Crystallogr. A 61 (2005) C139]. The facility consists of three beamlines; two based on canted undulators and one on a bending magnet. The scientific and technical goals of the CAT emphasize streamlined, efficient throughput for a variety of sample types, sizes and qualities, representing the cutting edge of structural biology research. For this purpose all three beamlines are equipped with the ALS-stylemore » robots [C.W.Cork, et al. Status of the BCSB automated sample mounting and alignment system for macromolecular crystallography at the Advanced Light Source, SRI-2003, San-Francisco, CA, USA, August 25-29, 2003] for an automated mounting of cryo-protected macromolecular crystals. This report summarizes software and technical solutions implemented with the first of the three operational robots at beamline 23-ID-B. The automounter's Dewar can hold up to 72 or 96 samples residing in six Rigaku ACTOR magazines or ALS-style pucks, respectively. Mounting of a crystal takes approximately 2 s, during which time the temperature of the crystal is maintained near that of liquid nitrogen.« less

Sacramento Valley, CA, USA

NASA Image and Video Library

1973-06-22

SL2-04-179 (22 June 1973) --- The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects. Photo credit: NASA

Sacramento Valley, CA, USA

NASA Technical Reports Server (NTRS)

1973-01-01

The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects.

77 FR 6587 - Startek USA, Inc. Alexandria, LA; Startek USA, Inc., Collinsville, VA; Amended Certification...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-75,089; TA-W-75,089A] Startek USA, Inc. Alexandria, LA; Startek USA, Inc., Collinsville, VA; Amended Certification Regarding Eligibility... for Worker Adjustment Assistance on January 26, 2011, applicable to workers of StarTek USA, Inc...

Subpopulation of store-operated Ca2+ channels regulate Ca2+-induced Ca2+ release in non-excitable cells.

PubMed

Yao, Jian; Li, Qin; Chen, Jin; Muallem, Shmuel

2004-05-14

Ca2+-induced Ca2+ release (CICR) is a well characterized activity in skeletal and cardiac muscles mediated by the ryanodine receptors. The present study demonstrates CICR in the non-excitable parotid acinar cells, which resembles the mechanism described in cardiac myocytes. Partial depletion of internal Ca2+ stores leads to a minimal activation of Ca2+ influx. Ca2+ influx through this pathway results in an explosive mobilization of Ca2+ from the majority of the stores by CICR. Thus, stimulation of parotid acinar cells in Ca2+ -free medium with 0.5 microm carbachol releases approximately 5% of the Ca2+ mobilizable by 1 mm carbachol. Addition of external Ca2+ induced the same Ca2+ release observed in maximally stimulated cells. Similar results were obtained by a short treatment with 2.5-10 microm cyclopiazonic acid, an inhibitor of the sarco/endoplasmic reticulum Ca2+ ATPase pump. The Ca2+ release induced by the addition of external Ca2+ was largely independent of IP(3)Rs because it was reduced by only approximately 30% by the inhibition of the inositol 1,4,5-trisphosphate receptors with caffeine or heparin. Measurements of Ca2+ -activated outward current and [Ca2+](i) suggested that most CICR triggered by Ca2+ influx occurred away from the plasma membrane. Measurement of the response to several concentrations of cyclopiazonic acid revealed that Ca2+ influx that regulates CICR is associated with a selective portion of the internal Ca2+ pool. The minimal activation of Ca2+ influx by partial store depletion was confirmed by the measurement of Mn2+ influx. Inhibition of Ca2+ influx with SKF96365 or 2-aminoethoxydiphenyl borate prevented activation of CICR observed on addition of external Ca2+. These findings provide evidence for activation of CICR by Ca2+ influx in non-excitable cells, demonstrate a previously unrecognized role for Ca2+ influx in triggering CICR, and indicate that CICR in non-excitable cells resembles CICR in cardiac myocytes with the exception that in

Carbonic anhydrase inhibitors: in vitro inhibition of α isoforms (hCA I, hCA II, bCA III, hCA IV) by flavonoids.

PubMed

Ekinci, Derya; Karagoz, Lutfi; Ekinci, Deniz; Senturk, Murat; Supuran, Claudiu T

2013-04-01

A series of flavonoids, such as quercetin, catechin, apigenin, luteolin, morin, were investigated for their inhibitory effects against the metalloenzyme carbonic anhydrase (CA). The compounds were tested against four α-CA isozymes purified from human and bovine (hCA I, hCA II, bCA III, hCA IV) tissues. The four isozymes showed quite diverse inhibition profiles with these compounds. The flavonoids inhibited hCA I with K(I)-s in the range of 2.2-12.8 μM, hCA II with K(I)-s in the range of 0.74-6.2 μM, bCA III with K(I)-s in the range of 2.2-21.3 μM, and hCA IV with inhibition constants in the range of 4.4-15.7, with an esterase assay using 4-nitrophenyl acetate as substrate. Some simple phenols/sulfonamides were also investigated as standard inhibitors. The flavonoids incorporate phenol moieties which inhibit these CAs through a diverse, not yet determined inhibition mechanism, compared to classic inhibitors such as the sulfonamide/sulfamate ones.

The Influence of Ca2+ Buffers on Free [Ca2+] Fluctuations and the Effective Volume of Ca2+ Microdomains

PubMed Central

Weinberg, Seth H.; Smith, Gregory D.

2014-01-01

Intracellular calcium (Ca2+) plays a significant role in many cell signaling pathways, some of which are localized to spatially restricted microdomains. Ca2+ binding proteins (Ca2+ buffers) play an important role in regulating Ca2+ concentration ([Ca2+]). Buffers typically slow [Ca2+] temporal dynamics and increase the effective volume of Ca2+ domains. Because fluctuations in [Ca2+] decrease in proportion to the square-root of a domain’s physical volume, one might conjecture that buffers decrease [Ca2+] fluctuations and, consequently, mitigate the significance of small domain volume concerning Ca2+ signaling. We test this hypothesis through mathematical and computational analysis of idealized buffer-containing domains and their stochastic dynamics during free Ca2+ influx with passive exchange of both Ca2+ and buffer with bulk concentrations. We derive Langevin equations for the fluctuating dynamics of Ca2+ and buffer and use these stochastic differential equations to determine the magnitude of [Ca2+] fluctuations for different buffer parameters (e.g., dissociation constant and concentration). In marked contrast to expectations based on a naive application of the principle of effective volume as employed in deterministic models of Ca2+ signaling, we find that mobile and rapid buffers typically increase the magnitude of domain [Ca2+] fluctuations during periods of Ca2+ influx, whereas stationary (immobile) Ca2+ buffers do not. Also contrary to expectations, we find that in the absence of Ca2+ influx, buffers influence the temporal characteristics, but not the magnitude, of [Ca2+] fluctuations. We derive an analytical formula describing the influence of rapid Ca2+ buffers on [Ca2+] fluctuations and, importantly, identify the stochastic analog of (deterministic) effective domain volume. Our results demonstrate that Ca2+ buffers alter the dynamics of [Ca2+] fluctuations in a nonintuitive manner. The finding that Ca2+ buffers do not suppress intrinsic domain [Ca2

Two new species of Pterostichus Bonelli subgenus Pseudoferonina Ball (Coleoptera, Carabidae, Pterostichini) from the mountains of central Idaho, U.S.A.

PubMed

Bergdahl, James C; Kavanaugh, David H

2011-01-01

Two new species of Pterostichus Bonelli subgenus Pseudoferonina Ball, are described from the mountains of central Idaho: Pterostichus bousqueti Bergdahl [type locality = small tributaries of South Fork of Payette River watershed, ca. 1170 m (3840 ft), 44.0675°; -115.6822°, near Lowman, Salmon River Mountains, Boise County, Idaho, U.S.A.] and Pterostichus lolo Bergdahl [type locality = Cottonwood/Orogrande Creek, ca. 870 m (2850 ft), 46.5528°; -115.5522°, North Fork of Clearwater River watershed, Clearwater Mountains, near Bungalow, Clearwater County, Idaho, U.S.A.]. Males of Pterostichus bousqueti and Pterostichus lolo are easily distinguished from each other and the seven previously described Pseudoferonina species by the form of the median lobe of the aedeagus, and from most individuals of the other species of Pseudoferonina in Idaho by features of pronotal shape and macrosculpture. Both species appear to be obligate ripicolous hygrophiles, restricted in distribution primarily to the margins of small montane streams in forested areas. Widespread intensive stream surveys for Pseudoferonina over many years indicate the geographic ranges of both species are highly localized, and additional undescribed species may occur in Idaho.

MRSA USA300 at Alaska Native Medical Center, Anchorage, Alaska, USA, 2000–2006

PubMed Central

Rudolph, Karen M.; Hennessy, Thomas W.; Zychowski, Diana L.; Asthi, Karthik; Boyle-Vavra, Susan; Daum, Robert S.

2012-01-01

To determine whether methicillin-resistant Staphylococcus aureus (MRSA) USA300 commonly caused infections among Alaska Natives, we examined clinical MRSA isolates from the Alaska Native Medical Center, Anchorage, during 2000–2006. Among Anchorage-region residents, USA300 was a minor constituent among MRSA isolates in 2000–2003 (11/68, 16%); by 2006, USA300 was the exclusive genotype identified (10/10). PMID:22264651

Analytic and Observational Approaches to Spacecraft Auroral Charging.

DTIC Science & Technology

1986-11-01

PERSONAL AUTHOR(S) T. G. Barker 1 TYPE 9F REPORT 13b. TIME COVERED 14 DATE OF REPORT (Year. Month, Day) S PAGE COUNT ~ Cientific No. 1 1FROM _____TO...A Division of Maxwell Laboratories P.O. Box 1620 La Jolla, CA 92038 DTIC ELECTE November 1986 S JUN1 97D j D Scientific Report No. 1 Approved for...MASSACHUSETTS 01731 8-7 CLASSI0 F I AG REPORT DOCUMENTATION PAGE IsREORT SECURITY CLASSIFICATION lb RESTRICTIVE NMARK;NGS- ’J. ’ !"’.SSiFIED

The Modeling of Drop-Containing Turbulent Eddies

DTIC Science & Technology

1989-11-01

gouttes denses. tandis que la twile do la grappe n’est pas un facteur limitant pour Ies grappes dilubes. On discuto des implications pratiques de ces...Conference, La Jolla, CA, July 9-12, 1989 VIII. SCIENTIFIC PERSONNEL SUPPORTED BY THE PROJECT AND DEGREES AWARDED DURING THE CONTRACT PERIOD. J. Bellan K. G...V + r )t(A1. 3) 4rd y, (t) = d Setting ’T - , = const in (A1. la ) and assuming that Yv <<l we find the equation for the wall Ywa d boundary, 37 Y =Y.Ua

Multiple C-terminal tail Ca2+/CaMs regulate CaV1.2 function but do not mediate channel dimerization

PubMed Central

Kim, Eun Young; Rumpf, Christine H; Van Petegem, Filip; Arant, Ryan J; Findeisen, Felix; Cooley, Elizabeth S; Isacoff, Ehud Y; Minor, Daniel L

2010-01-01

Interactions between voltage-gated calcium channels (CaVs) and calmodulin (CaM) modulate CaV function. In this study, we report the structure of a Ca2+/CaM CaV1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca2+/CaMs and two Ca2+/CaM–IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca2+/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes CaV1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca2+/CaMs in the complex have different properties. Ca2+/CaM bound to the PreIQ C-region is labile, whereas Ca2+/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca2+/CaMs can bind the CaV1.2 tail simultaneously and indicate a functional role for Ca2+/CaM at the C-region site. PMID:20953164

Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization.

PubMed

Kim, Eun Young; Rumpf, Christine H; Van Petegem, Filip; Arant, Ryan J; Findeisen, Felix; Cooley, Elizabeth S; Isacoff, Ehud Y; Minor, Daniel L

2010-12-01

Interactions between voltage-gated calcium channels (Ca(V)s) and calmodulin (CaM) modulate Ca(V) function. In this study, we report the structure of a Ca(2+)/CaM Ca(V)1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca(2+)/CaMs and two Ca(2+)/CaM-IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca(2+)/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes Ca(V)1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca(2+)/CaMs in the complex have different properties. Ca(2+)/CaM bound to the PreIQ C-region is labile, whereas Ca(2+)/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca(2+)/CaMs can bind the Ca(V)1.2 tail simultaneously and indicate a functional role for Ca(2+)/CaM at the C-region site.

The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

PubMed

González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H

2014-01-01

An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p < 0.05) than ileal endogenous fluxes and total tract endogenous losses of Ca, but ileal endogenous fluxes were less (p < 0.05) than total tract endogenous losses. Standardised digestibility of Ca was not affected by the level of phytic acid, but decreased (p < 0.05) as Ca level increased in L. calcareum Ca diets, but that was not the case if calcium carbonate was the source of Ca (interaction, p < 0.05). The standardised duodenal digestibility (SDD), standardised ileal digestibility (SID) and standardised total tract digestibility (STTD) of Ca were not different if calcium carbonate was the source of dietary Ca. However, the STTD of Ca in L. calcareum Ca was greater (p < 0.05) than the SID and SDD of Ca. The SDD, SID and STTD of Ca in calcium carbonate were greater (p < 0.05) than those of L. calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly

Ca2+ current vs. Ca2+ channel cooperativity of exocytosis

PubMed Central

Matveev, Victor; Bertram, Richard; Sherman, Arthur

2009-01-01

Recently there has been significant interest and progress in the study of spatio-temporal dynamics of Ca2+ that triggers exocytosis at a fast chemical synapse, which requires understanding the contribution of individual calcium channels to the release of a single vesicle. Experimental protocols provide insight into this question by probing the sensitivity of exocytosis to Ca2+ influx. While varying extracellular or intracellular Ca2+ concentration assesses the intrinsic biochemical Ca2+ cooperativity of neurotransmitter release, varying the number of open Ca2+ channels using pharmacological channel block or the tail current titration probes the cooperativity between individual Ca2+ channels in triggering exocytosis. Despite the wide use of these Ca2+ sensitivity measurements, their interpretation often relies on heuristic arguments. Here we provide a detailed analysis of the Ca2+ sensitivity measures probed by these experimental protocols, present simple expressions for special cases, and demonstrate the distinction between the Ca2+ current cooperativity, defined by the relationship between exocytosis rate and the whole-terminal Ca2+ current magnitude, and the underlying Ca2+ channel cooperativity, defined as the average number of channels involved in the release of a single vesicle. We find simple algebraic expressions that show that the two are different but linearly related. Further, we use 3D computational modeling of buffered Ca2+ diffusion to analyze these distinct Ca2+ cooperativity measures, and demonstrate the role of endogenous Ca2+ buffers on such measures. We show that buffers can either increase or decrease the Ca2+ current cooperativity of exocytosis, depending on their concentration and the single-channel Ca2+ current. PMID:19793978

Ca2+/Cation Antiporters (CaCA): Identification, Characterization and Expression Profiling in Bread Wheat (Triticum aestivum L.)

PubMed Central

Taneja, Mehak; Tyagi, Shivi; Sharma, Shailesh; Upadhyay, Santosh Kumar

2016-01-01

The Ca2+/cation antiporters (CaCA) superfamily proteins play vital function in Ca2+ ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in Triticum aestivum (bread wheat). Herein, we identified 34 TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL, and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the T. aestivum comprises an allohexaploid genome, TaCaCA genes were derived from each A, B, and D subgenome and homeologous chromosome (HC), except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs) due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about 10 transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the TaCaCA genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like TaCAX1-A and TaNCL1-B indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections) and abiotic stresses (heat, drought, salt) suggested their role in stress response. Majority of TaCCX and TaNCL family genes were found highly affected during various abiotic stresses. However, the role of individual gene needs to be established. The present study unfolded the opportunity for detail functional

Ca2+/Cation Antiporters (CaCA): Identification, Characterization and Expression Profiling in Bread Wheat (Triticum aestivum L.).

PubMed

Taneja, Mehak; Tyagi, Shivi; Sharma, Shailesh; Upadhyay, Santosh Kumar

2016-01-01

The Ca 2+ /cation antiporters (CaCA) superfamily proteins play vital function in Ca 2+ ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in Triticum aestivum (bread wheat). Herein, we identified 34 TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL, and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the T. aestivum comprises an allohexaploid genome, TaCaCA genes were derived from each A, B, and D subgenome and homeologous chromosome (HC), except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs) due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about 10 transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the TaCaCA genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like TaCAX1-A and TaNCL1-B indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections) and abiotic stresses (heat, drought, salt) suggested their role in stress response. Majority of TaCCX and TaNCL family genes were found highly affected during various abiotic stresses. However, the role of individual gene needs to be established. The present study unfolded the opportunity for detail

Inhibitors of the Ca{sup 2+}/calmodulin-dependent protein kinase phosphatase family (CaMKP and CaMKP-N)

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

Sueyoshi, Noriyuki; Takao, Toshihiko; Nimura, Takaki

2007-11-23

Ca{sup 2+}/calmodulin-dependent protein kinase phosphatase (CaMKP) and its nuclear isoform CaMKP-N are unique Ser/Thr protein phosphatases that negatively regulate the Ca{sup 2+}/calmodulin-dependent protein kinase (CaMK) cascade by dephosphorylating multifunctional CaMKI, II, and IV. However, the lack of specific inhibitors of these phosphatases has hampered studies on these enzymes in vivo. In an attempt to obtain specific inhibitors, we searched inhibitory compounds and found that Evans Blue and Chicago Sky Blue 6B served as effective inhibitors for CaMKP. These compounds also inhibited CaMKP-N, but inhibited neither protein phosphatase 2C, another member of PPM family phosphatase, nor calcineurin, a typical PPP familymore » phosphatase. The minimum structure required for the inhibition was 1-amino-8-naphthol-4-sulfonic acid. When Neuro2a cells cotransfected with CaMKIV and CaMKP-N were treated with these compounds, the dephosphorylation of CaMKIV was strongly suppressed, suggesting that these compounds could be used as potent inhibitors of CaMKP and CaMKP-N in vivo as well as in vitro.« less

Occurrence of wide-chain Ca-pyriboles as primary crystals in the Salton Sea Geothermal Field, California, USA

NASA Astrophysics Data System (ADS)

Yau, Yu-Chyi; Peacor, Donald R.; Essene, Eric J.

1986-09-01

Amphiboles and pyroxenes occurring in the Salton Sea Geothermal Field were found to contain coherent intergrowths of chain silicates with other than double and single chain widths by using transmission and analytical electron microscopy. Both occur in the biotite zone at the temperature (depth) interval of 310° C (1,060 m) to 330° C (1,547m) which approximately corresponds to temperatures of the greenschist facies. The amphiboles occur as euhedral fibrous crystals occupying void space and are composed primarily of irregularly alternating (010) slabs of double or triple chains, with rare quadruple and quintuple chains. Primary crystallization from solution results in euhedral crystals. Clinopyroxenes formed mainly as a porefilling cement and subordinately as prismatic crystals coexisting with fibrous amphiboles. Fine lamellae of double and triple chains are irregularly intercalated with pyroxene. AEM analyses yield formulae (Ca1.8Mg2.9Fe1.9Mn0.1) Si8O21.8(OH)1.8 (310° C) and (Ca2.0Fe2.5Mg2.3) Si8O21.8 (OH)2.0 (330° C) for amphiboles and (Ca1.1Fe0.6Mg0.3) Si2O6 for clinopyroxene. Thermodynamic calculations at Pfluid=100 bar of equilibrium reactions of (1) 3 chlorite +10 calcite + 21 quartz = 3 actinolite + 2 clinozoisite + 8 H2O + 10 CO2 and (2) actinolite+ 3 calcite+ 2 quartz = 5 clinopyroxene + H2O + 3 CO2 using Mg-end member phases indicate that formation of amphibole and pyroxene require very water-rich conditions (X_{CO_2 } < 0.06) at temperatures below 330° C.

Signatures of cytoplasmic proteins in the exoproteome distinguish community- and hospital-associated methicillin-resistant Staphylococcus aureus USA300 lineages.

PubMed

Mekonnen, Solomon A; Palma Medina, Laura M; Glasner, Corinna; Tsompanidou, Eleni; de Jong, Anne; Grasso, Stefano; Schaffer, Marc; Mäder, Ulrike; Larsen, Anders R; Gumpert, Heidi; Westh, Henrik; Völker, Uwe; Otto, Andreas; Becher, Dörte; van Dijl, Jan Maarten

2017-08-18

Methicillin-resistant Staphylococcus aureus (MRSA) is the common name for a heterogeneous group of highly drug-resistant staphylococci. Two major MRSA classes are distinguished based on epidemiology, namely community-associated (CA) and hospital-associated (HA) MRSA. Notably, the distinction of CA- and HA-MRSA based on molecular traits remains difficult due to the high genomic plasticity of S. aureus. Here we sought to pinpoint global distinguishing features of CA- and HA-MRSA through a comparative genome and proteome analysis of the notorious MRSA lineage USA300. We show for the first time that CA- and HA-MRSA isolates can be distinguished by 2 distinct extracellular protein abundance clusters that are predictive not only for epidemiologic behavior, but also for their growth and survival within epithelial cells. This 'exoproteome profiling' also groups more distantly related HA-MRSA isolates into the HA exoproteome cluster. Comparative genome analysis suggests that these distinctive features of CA- and HA-MRSA isolates relate predominantly to the accessory genome. Intriguingly, the identified exoproteome clusters differ in the relative abundance of typical cytoplasmic proteins, suggesting that signatures of cytoplasmic proteins in the exoproteome represent a new distinguishing feature of CA- and HA-MRSA. Our comparative genome and proteome analysis focuses attention on potentially distinctive roles of 'liberated' cytoplasmic proteins in the epidemiology and intracellular survival of CA- and HA-MRSA isolates. Such extracellular cytoplasmic proteins were recently invoked in staphylococcal virulence, but their implication in the epidemiology of MRSA is unprecedented.

Nitric Oxide Induces Ca2+-independent Activity of the Ca2+/Calmodulin-dependent Protein Kinase II (CaMKII)*

PubMed Central

Coultrap, Steven J.; Bayer, K. Ulrich

2014-01-01

Both signaling by nitric oxide (NO) and by the Ca2+/calmodulin (CaM)-dependent protein kinase II α isoform (CaMKIIα) are implicated in two opposing forms of synaptic plasticity underlying learning and memory, as well as in excitotoxic/ischemic neuronal cell death. For CaMKIIα, these functions specifically involve also Ca2+-independent autonomous activity, traditionally generated by Thr-286 autophosphorylation. Here, we demonstrate that NO-induced S-nitrosylation of CaMKIIα also directly generated autonomous activity, and that CaMKII inhibition protected from NO-induced neuronal cell death. NO induced S-nitrosylation at Cys-280/289, and mutation of either site abolished autonomy, indicating that simultaneous nitrosylation at both sites was required. Additionally, autonomy was generated only when Ca2+/CaM was present during NO exposure. Thus, generation of this form of CaMKIIα autonomy requires simultaneous signaling by NO and Ca2+. Nitrosylation also significantly reduced subsequent CaMKIIα autophosphorylation specifically at Thr-286, but not at Thr-305. A previously described reduction of CaMKII activity by S-nitrosylation at Cys-6 was also observed here, but only after prolonged (>5 min) exposure to NO donors. These results demonstrate a novel regulation of CaMKII by another second messenger system and indicate its involvement in excitotoxic neuronal cell death. PMID:24855644

Structures of Ca(V) Ca**2+/CaM-IQ Domain Complexes Reveal Binding Modes That Underlie Calcium-Dependent Inactivation And Facilitation

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

Kim, E.Y.; Rumpf, C.H.; Fujiwara, Y.

2009-05-20

Calcium influx drives two opposing voltage-activated calcium channel (Ca{sub V}) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca{sup 2+}/calmodulin (Ca{sup 2+}/CaM) lobes produce CDI and CDF through interactions with the Ca{sub V}{alpha}{sub 1} subunit IQ domain. Curiously, Ca{sup 2+}/CaM lobe modulation polarity appears inverted between Ca{sub V}1s and Ca{sub V}2s. Here, we present crystal structures of Ca{sub V}2.1, Ca{sub V}2.2, and Ca{sub V}2.3 Ca{sup 2+}/CaM-IQ domain complexes. All display binding orientations opposite to Ca{sub V}1.2 with a physical reversal of the CaM lobe positions relative to the IQ {alpha}-helix. Titration calorimetry reveals lobe competition for a high-affinitymore » site common to Ca{sub V}1 and Ca{sub V}2 IQ domains that is occupied by the CDI lobe in the structures. Electrophysiological experiments demonstrate that the N-terminal Ca{sub V}2 Ca{sup 2+}/C-lobe anchors affect CDF. Together, the data unveil the remarkable structural plasticity at the heart of Ca{sub V} feedback modulation and indicate that Ca{sub V}1 and Ca{sub V}2 IQ domains bear a dedicated CDF site that exchanges Ca{sup 2+}/CaM lobe occupants.« less

Photocatalyst of Perovskite CaTiO3 Nanopowder Synthesized from CaO derived from Snail Shell in Comparison with The Use of CaO and CaCO3

NASA Astrophysics Data System (ADS)

Fatimah, I.; Rahmadianti, Y.; Pudiasari, R. A.

2018-04-01

Calcium titanate belongs to the important group of compounds with a perovskite structure having high dielectric loss for various applications including photocatalysis mechanism. Refer to the principles of green chemistry, in this work preparation of CaTiO3 was conducted by using CaO derived from snail shell. Aim of this research are to study the physicochemical character of perovskite derived from snail shell and its comparison with CaO and CaCO3 as Ca sources. Material preparation was performed by solid reaction of Ca sources with TiO2 under comparison with CaO and CaCO3 precursors. Mixture of Ca sources with TiO2 in certain proportion were ground and calcined at the temperature of 200 °C for 2 hs. Materials were characterized by using X-ray diffractometer (XRD), Fourier Transform-Infra Red (FTIR) and the photocatalytic activity was tested by using methylene blue photooxidation. Perovskite synthesized using CaO derived from snail shell exhibits the similar XRD pattern with that were prepared by using CaO and CaCO3. From the photooxidation activity test, it is proven that CaTiO3 shows similar photocatalytic activity correspond to that were prepared by CaO and CaCO3. Utilazation of shell as agricultural waste of the synthesis of CaTiO3 perovskite is the novelty of this work. Furthermore, the study on material structure and photoactivity is the main focuses for the application in industry and environment.

Radiocarbon constraints on fossil thinolite tufa formation in the Mono Basin, CA, USA

NASA Astrophysics Data System (ADS)

Leroy, S. L.; Zimmerman, S. R.; Hemming, S. R.; Stine, S.; Guilderson, T. P.

2009-12-01

Mono Lake is a terminal lake located at the western edge of the Great Basin, and is famous for its tufa towers. Thinolite, which is thought to be a CaCO3 pseudomorph of ikaite, is found around the Mono Basin in many fossil tufa towers, particularly at elevations above 2000 meters. The subaqueous parent mineral ikaite forms at low temperatures (< 6 °C) (Bischoff et al., 1993) and requires specific water chemistry. Previous radiocarbon dating of fossil tufa towers around the Mono Basin has yielded a rather small range of ages for the highest elevation towers, between 11.8 and 14.1 14C kyr BP (no corrections for reservoir effects have been made). A thinolite fan collected from outcrops in Mill Creek, just north of the current Mono Lake yielded an age of 10,690 ± 45 14C yr BP (12,750 ± 80 cal yr BP), consistent with a ca. 1000 year reservoir age and coincidence with thinolite crystals found in a core from the northwestern embayment of Mono Lake (Davis, 1999, QR), and thus correlating with the Younger Dryas cooling event as exhibited in the GISP2 δ18O record. While most of the thinolite textures are found at high elevations, we sampled a mound at 1955 meters (near the current shoreline, north of the lake and just east of Black Point) that has many concentric layers, some containing thinolite textures. Although tufa mounds can form very rapidly, the location at low elevation and the presence of at least 19 distinct layers led us to consider that this mound might represent a long term record of Mono Lake’s chemistry. The new data confirm that the mound formed over a long period within the last glacial cycle, with ages ranging beyond the current limits of measurement (>34 kyr) to as young as 15.5 14C kyr BP. In general there is a consistent stratigraphic trend of ages within the mound, but the thinolite ages are anomalously young and one thinolite sample shows a large age reversal. The best estimate of the age of the precipitation of this tufa mound is given by the

The initial 41Ca/40Ca ratios in two type A Ca-Al-rich inclusions: Implications for the origin of short-lived 41Ca

NASA Astrophysics Data System (ADS)

Liu, Ming-Chang

2017-03-01

This paper reports new 41Ca-41K isotopic data for two Type A CAIs, NWA 3118 #1Nb (Compact Type A) and Vigarano 3138 F8 (Fluffy Type A), from reduced CV3 chondrites. The NWA CAI is found to have carried live 41Ca at the level of (4.6 ± 1.9) ×10-9 , consistent with the proposed Solar System initial 41Ca /40Ca = 4.2 ×10-9 by Liu et al. (2012a). On the other hand, the Vigarano CAI does not have resolvable radiogenic 41K excesses that can be attributed to the decay of 41Ca. Combined with the 26Al data that have been reported for these two CAIs, we infer that the 41Ca distribution was not homogeneous when 26Al was widespread at the canonical level of 26Al /27Al = 5.2 ×10-5 . Such a 41Ca heterogeneity can be understood under two astrophysical contexts: in situ charged particle irradiation by the protoSun in the solar nebula that had inherited some baseline 10Be abundance from the molecular cloud, and Solar System formation in a molecular cloud enriched in 26Al and 41Ca contaminated by massive star winds. That said, more high quality 41Ca data are still needed to better understand the origin of this radionuclide.

Cytosolic Ca2+ Buffers

PubMed Central

Schwaller, Beat

2010-01-01

“Ca2+ buffers,” a class of cytosolic Ca2+-binding proteins, act as modulators of short-lived intracellular Ca2+ signals; they affect both the temporal and spatial aspects of these transient increases in [Ca2+]i. Examples of Ca2+ buffers include parvalbumins (α and β isoforms), calbindin-D9k, calbindin-D28k, and calretinin. Besides their proven Ca2+ buffer function, some might additionally have Ca2+ sensor functions. Ca2+ buffers have to be viewed as one of the components implicated in the precise regulation of Ca2+ signaling and Ca2+ homeostasis. Each cell is equipped with proteins, including Ca2+ channels, transporters, and pumps that, together with the Ca2+ buffers, shape the intracellular Ca2+ signals. All of these molecules are not only functionally coupled, but their expression is likely to be regulated in a Ca2+-dependent manner to maintain normal Ca2+ signaling, even in the absence or malfunctioning of one of the components. PMID:20943758

Near-membrane [Ca2+] transients resolved using the Ca2+ indicator FFP18.

PubMed

Etter, E F; Minta, A; Poenie, M; Fay, F S

1996-05-28

(Ca2+)-sensitive processes at cell membranes involved in contraction, secretion, and neurotransmitter release are activated in situ or in vitro by Ca2+ concentrations ([Ca2+]) 10-100 times higher than [Ca2+] measured during stimulation in intact cells. This paradox might be explained if the local [Ca2+] at the cell membrane is very different from that in the rest of the cell. Soluble Ca2+ indicators, which indicate spatially averaged cytoplasmic [Ca2+], cannot resolve these localized, near-membrane [Ca2+] signals. FFP18, the newest Ca2+ indicator designed to selectively monitor near-membrane [Ca2+], has a lower Ca2+ affinity and is more water soluble than previously used membrane-associating Ca2+ indicators. Images of the intracellular distribution of FFP18 show that >65% is located on or near the plasma membrane. [Ca2+] transients recorded using FFP18 during membrane depolarization-induced Ca2+ influx show that near-membrane [Ca2+] rises faster and reaches micromolar levels at early times when the cytoplasmic [Ca2+], recorded using fura-2, has risen to only a few hundred nanomolar. High-speed series of digital images of [Ca2+] show that near-membrane [Ca2+], reported by FFP18, rises within 20 msec, peaks at 50-100 msec, and then declines. [Ca2+] reported by fura-2 rose slowly and continuously throughout the time images were acquired. The existence of these large, rapid increases in [Ca2+] directly beneath the surface membrane may explain how numerous (Ca2+)-sensitive membrane processes are activated at times when bulk cytoplasmic [Ca2+] changes are too small to activate them.

A comparison of bone-related biomarkers and CA27.29 to assess response to treatment of osseous metastatic breast cancer.

PubMed

Lüfter, D; Richter, A; Günther, S; Flath, B; Akrivakis, C; Geppert, R; Wernecke, K D; Possinger, K

2000-01-01

The assessment of bone metastases by clinical examination or imaging techniques is still considered unreliable. We compared a specific marker of bone resorption, urinary deoxypyridinoline (DPD)-crosslinks, with serum calcium (Ca), alkaline phosphatase (AP) and CA27.29, to evaluate the status of bone metastases in patients with breast cancer. Second morning voided urine was collected from 2 groups of patient (pts), those without evidence of disease (n = 118), and those with bone metastases (n = 85) under specific therapy plus pamidronate. DPD and CA27.29 were measured on the automated ACS180 system (Bayer Diagnostics, Tarrytown, NY, USA). Receiver operating characteristics (ROC) curves were established for each of the 4 biomarkers to determine whether they could distinguish the 2 subsets of pts with clinically sufficient validity, and to establish the corresponding cut-off values. Neither Ca nor AP was useful in discriminating the 2 subgroups. At a DPD cut-off of 13 nmol/mmol, we found a specificity of 69% and a sensitivity of 53% for diagnosing bone metastases. Best results, however, were seen for CA27.29. A cut-off value of 30 U/ml resulted in a specificity of 62% and a sensitivity of 81%. CA27.29 was the best parameter for the discrimination of stage IV breast cancer with bone metastases. The primary advantage of DPD lies in the monitoring of bone metastases under specific therapy.

Tidal and Lunar Data for Point Mugu, San Nicolas Island, and the Barking Sands Area During 1988.

DTIC Science & Technology

1987-12-31

C l vNvN-A -0%Ow’!’N N r--Me’a In v-(v0r-v inav -f -X W WI- 0 -!)0 N~o CD NI- 0V NMQ-N o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ V KU LMM tt-y d tL) J O’ed.ci I o -a NM...Commander Third Fleet 1 Pearl Harbor, HI 96860-7500 Commander Naval Weapons Center Attn: Earth and Planetary Sciences Division 1 Code 343 (Technical...Center P.O. Box 271 Attn: Fishery-Oceanographic Group La Jolla, CA 92037 University of California Department of Biological Sciences Attn: Dr. A. M

ITER Plasma at Electron Cyclotron Frequency Domain: Stimulated Raman Scattering off Gould-Trivelpiece Modes and Generation of Suprathermal Electrons and Energetic Ions

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2011-04-01

Stimulated Raman scattering in the electron cyclotron frequency range of the X-Mode and O-Mode driver with the ITER plasma leads to the ``tail heating'' via the generation of suprathermal electrons and energetic ions. The scattering off Trivelpiece-Gould (T-G) modes is studied for the gyrotron frequency of 170GHz; X-Mode and O-Mode power of 24 MW CW; on-axis B-field of 10T. The synergy between the two-plasmon decay and Raman scattering is analyzed in reference to the bulk plasma heating. Supported in part by Nikola TESLA Labs, La Jolla, CA

Fast Ignition Thermonuclear Fusion: Enhancement of the Pellet Gain by the Colossal-Magnetic-Field Shells

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2013-10-01

The fast ignition fusion pellet gain can be enhanced by a laser generated B-field shell. The B-field shell, (similar to Earth's B-field, but with the alternating B-poles), follows the pellet compression in a frozen-in B-field regime. A properly designed laser-pellet coupling can lead to the generation of a B-field shell, (up to 100 MG), which inhibits electron thermal transport and confines the alpha-particles. In principle, a pellet gain of few-100s can be achieved in this manner. Supported in part by Nikola Tesla Labs, Stefan University, 1010 Pearl, La Jolla, CA 92038-1007.

Perioperative Pain Management of a Patient Taking Naltrexone HCl/Bupropion HCl (Contrave): A Case Report.

PubMed

Ninh, Allen; Kim, Sang; Goldberg, Andrew

2017-10-15

A 42-year-old obese woman (body mass index = 30.2 kg/m) presented for urgent anterior cervical diskectomy and fusion. She had been taking oral naltrexone-bupropion extended-release (Contrave, Orexigen Therapeutics Inc, La Jolla, CA) for the past 6 months and continued using it until 12 hours preoperatively. Despite discontinuation of this medication, and employing an intraoperative and postoperative multimodal analgesia strategy, immediate pain control was inadequately achieved. Patients taking opioid antagonists who present for surgery pose unique challenges to the anesthesiologist and require extensive preoperative interdisciplinary discussions and planning for pain control throughout the perioperative period.

Stem Cell Physics. Laser Manipulation of Blood Types: Laser-Stripping-Away of Red Blood Cell Surface Antigens

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2014-03-01

A novel mechanism of importance for the transfusion medicine[2] is proposed. The interaction of ultrashort wavelength multilaser beams with the flowing blood thin films can lead to a conversion of blood types A, B, and AB into O type.[3] The stripping away of antigens is done by the scanning-multiple-lasers of a high repetition rate in the blue-purple frequency domain. The guiding-lasers are in the red-green frequency domain. The laser force, (parametric interaction with the antigen eigen-oscillation),[4] upon the antigen protein molecule must exceed its weight. Supported by Nikola Tesla Labs, La Jolla, CA.

78 FR 49270 - Information Collection; MyUSA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... Floor, Washington, DC 20405- 0001. ATTN: Hada Flowers/IC 3090-00XX; MyUSA. Instructions: Please submit...-4755. ATTN: Hada Flowers/ IC 3090-00xx; MyUSA. Please cite OMB Control No. 3090-XXXX; MyUSA, in all...

Pre-Steady-State Kinetics of Ba-Ca Exchange Reveals a Second Electrogenic Step Involved in Ca2+ Translocation by the Na-Ca Exchanger

PubMed Central

Haase, Andreas; Hartung, Klaus

2009-01-01

Kinetic properties of the Na-Ca exchanger (guinea pig NCX1) expressed in Xenopus oocytes were investigated with excised membrane patches in the inside-out configuration and photolytic Ca2+ concentration jumps with either 5 mM extracellular Sr2+ or Ba2+. After a Ca2+ concentration jump on the cytoplasmic side, the exchanger performed Sr-Ca or Ba-Ca exchange. In the Sr-Ca mode, currents are transient and decay in a monoexponential manner similar to that of currents in the Ca-Ca exchange mode described before. Currents recorded in the Ba-Ca mode are also transient, but the decay is biphasic. In the Sr-Ca mode the amount of charge translocated increases at negative potentials in agreement with experiments performed in the Ca-Ca mode. In the Ba-Ca mode the total amount of charge translocated after a Ca2+ concentration jump is ∼4 to 5 times that in Ca-Ca or Sr-Ca mode. In the Ba-Ca mode the voltage dependence of charge translocation depends on the Ca2+ concentration on the cytosolic side before the Ca2+ concentration jump. At low initial Ca2+ levels (∼0.5 μM), charge translocation is voltage independent. At a higher initial concentration (1 μM Ca2+), the amount of charge translocated increases at positive potentials. Biphasic relaxation of the current was also observed in the Ca-Ca mode if the external Ca2+ concentration was reduced to ≤0.5 mM. The results reported here and in previous publications can be described by using a 6-state model with two voltage-dependent conformational transitions. PMID:19486679

Theoretical study on the potential energy surfaces of CaNC and CaCN

NASA Astrophysics Data System (ADS)

Ishii, Keisaku; Taketsugu, Tetsuya; Hirano, Tsuneo

2003-06-01

The potential energy surfaces of CaNC ( overlineX2Σ+) and CaCN ( overlineX2Σ+) have been investigated by the highly correlated ab initio molecular orbital methods. The bending potential for CaNC is shallow, and shows quite anharmonic and anomalous character, which can explain why the centrifugal distortion constants up to the tenth order were required for the analysis of its rotational spectrum. The reaction path for the isomerization reaction of CaNC and CaCN was also determined: The activation barrier is 2111 cm -1 from the CaNC side, and 602 cm -1 from the CaCN side. Core-core and core-valence correlation contributions of Ca M-shell electrons make the Ca-N (for CaNC) and Ca-C (for CaCN) bond lengths shorter by 0.05 and 0.04 Å, respectively, which indicates the significance of these core-correlation effects.

Opposing Intermolecular Tuning of Ca2+ Affinity for Calmodulin by Neurogranin and CaMKII Peptides.

PubMed

Zhang, Pengzhi; Tripathi, Swarnendu; Trinh, Hoa; Cheung, Margaret S

2017-03-28

We investigated the impact of bound calmodulin (CaM)-target compound structure on the affinity of calcium (Ca 2+ ) by integrating coarse-grained models and all-atomistic simulations with nonequilibrium physics. We focused on binding between CaM and two specific targets, Ca 2+ /CaM-dependent protein kinase II (CaMKII) and neurogranin (Ng), as they both regulate CaM-dependent Ca 2+ signaling pathways in neurons. It was shown experimentally that Ca 2+ /CaM (holoCaM) binds to the CaMKII peptide with overwhelmingly higher affinity than Ca 2+ -free CaM (apoCaM); the binding of CaMKII peptide to CaM in return increases the Ca 2+ affinity for CaM. However, this reciprocal relation was not observed in the Ng peptide (Ng 13-49 ), which binds to apoCaM or holoCaM with binding affinities of the same order of magnitude. Unlike the holoCaM-CaMKII peptide, whose structure can be determined by crystallography, the structural description of the apoCaM-Ng 13-49 is unknown due to low binding affinity, therefore we computationally generated an ensemble of apoCaM-Ng 13-49 structures by matching the changes in the chemical shifts of CaM upon Ng 13-49 binding from nuclear magnetic resonance experiments. Next, we computed the changes in Ca 2+ affinity for CaM with and without binding targets in atomistic models using Jarzynski's equality. We discovered the molecular underpinnings of lowered affinity of Ca 2+ for CaM in the presence of Ng 13-49 by showing that the N-terminal acidic region of Ng peptide pries open the β-sheet structure between the Ca 2+ binding loops particularly at C-domain of CaM, enabling Ca 2+ release. In contrast, CaMKII peptide increases Ca 2+ affinity for the C-domain of CaM by stabilizing the two Ca 2+ binding loops. We speculate that the distinctive structural difference in the bound complexes of apoCaM-Ng 13-49 and holoCaM-CaMKII delineates the importance of CaM's progressive mechanism of target binding on its Ca 2+ binding affinities. Copyright © 2017

[The quantitative changes of bioelements (Ca, Zn, Mg, Cu, Mn) in crystalline lenses under the influence of hypodynamic stress and zinc].

PubMed

Kusleika, Saulius

2002-01-01

The aim of the study was to investigate and estimate quantitative changes of bioelements (Ca, Zn, Mg, Cu, Mn) in the lenses on the influence of hypodynamic stress and zinc (Zn). Hypodynamic stress of 48 days duration was provoked for Chinchilla rabbits (n = 20) by placing them in metal hutches. Every day (48 days) 10 rabbits, which had intervention received 0.3 mg/kg body wt. doses of Zn (in form of Zn acetate). The rabbits (n = 10) of the control group, which had no intervention were kept in vivarium conditions. Concentration of bioelements in the lenses of rabbits was detected by atomic absorption spectrophotometry 503 "Perkin-Elmer" (USA). The investigation revealed that hypodynamic stress of 48 days duration caused the increase in amount of Ca, Zn, Mn in lenses as compared with that in control rabbits and in rabbits receiving Zn. The concentration of bioelements (Ca, Zn, Mg, Cu, Mn) in lenses of rabbits receiving Zn in case of hypodynamic stress did not change significantly.

Exploring the metabolic potential of microbial communities in ultra-basic, reducing springs at The Cedars, CA, USA: Experimental evidence of microbial methanogenesis and heterotrophic acetogenesis

NASA Astrophysics Data System (ADS)

Kohl, Lukas; Cumming, Emily; Cox, Alison; Rietze, Amanda; Morrissey, Liam; Lang, Susan Q.; Richter, Andreas; Suzuki, Shino; Nealson, Kenneth H.; Morrill, Penny L.

2016-04-01

Present-day serpentinization generates groundwaters with conditions (pH > 11, Eh < -550 mV) favorable for the microbial and abiotic production of organic compounds from inorganic precursors. Elevated concentrations of methane, C2-C6 alkanes, acetate, and formate have been detected at these sites, but the microbial or abiotic origin of these compounds remains unclear. While geochemical data indicate that methane at most sites of present-day serpentinization is abiogenic, the stable carbon, hydrogen, and clumped isotope data as well as the hydrocarbon gas composition from The Cedars, CA, USA, are consistent with a microbial origin for methane. However, there is no direct evidence of methanogenesis at this site of serpentinization. We report on laboratory experiments in which the microbial communities in fluids and sediments from The Cedars were incubated with 13C labeled substrates. Increasing methane concentrations and the incorporation of 13C into methane in live experiments, but not in killed controls, demonstrated that methanogens converted methanol, formate, acetate (methyl group), and bicarbonate to methane. The apparent fractionation between methane and potential substrates (α13CCH4-CO2(g) = 1.059 to 1.105, α13CCH4-acetate = 1.042 to 1.119) indicated that methanogenesis was dominated by the carbonate reduction pathway. Increasing concentrations of volatile organic acid anions indicated microbial acetogenesis. α13CCO2(g)-acetate values (0.999 to 1.000), however, were inconsistent with autotrophic acetogenesis, thus suggesting that acetate was produced through fermentation. This is the first study to show direct evidence of microbial methanogenesis and acetogenesis by the native microbial community at a site of present-day serpentinization.

Expression of Bacillus thuringiensis cytolytic toxin (Cyt2Ca1) in citrus roots to control Diaprepes abbreviatus larvae.

PubMed

Mahmoud, Sulley Ben; Ramos, John E; Shatters, Robert G; Hall, David G; Lapointe, Stephen L; Niedz, Randall P; Rougé, Pierre; Cave, Ronald D; Borovsky, Dov

2017-03-01

Diaprepes abbreviatus (L.) is an important pest of citrus in the USA. Currently, no effective management strategies of D. abbreviatus exist in citriculture, and new methods of control are desperately sought. To protect citrus against D. abbreviatus a transgenic citrus rootstock expressing Bacillus thuringiensis Cyt2Ca1, an insect toxin protein, was developed using Agrobacterium-mediated transformation of 'Carrizo' citrange [Citrus sinensis (L) Osbeck Poncirus trifoliate (L) Raf]. The transgenic citrus root stock expressed the cytolytic toxin Cyt2Ca1 constitutively under the control of a 35S promoter in the transgenic Carrizo citrange trifoliate hybrid including the roots that are the food source of larval D. abbreviatus. The engineered citrus was screened by Western blot and RT-qPCR analyses for cyt2Ca1 and positive citrus identified. Citrus trees expressing different levels of cyt2Ca1 transcripts were identified (Groups A-C). High expression of the toxin in the leaves (10 9 transcripts/ng RNA), however, retarded plant growth. The transgenic plants were grown in pots and the roots exposed to 3week old D. abbreviatus larvae using no-choice plant bioassays. Three cyt2Ca1 transgenic plants were identified that sustained less root damage belonging to Group B and C. One plant caused death to 43% of the larvae that fed on its roots expressed 8×10 6 cyt2Ca1 transcripts/ng RNA. These results show, for the first time, that Cyt2Ca1 expressed in moderate amounts by the roots of citrus does not retard citrus growth and can protect it from larval D. abbreviatus. Published by Elsevier Inc.

Mg/Ca, Sr/Ca and Ca isotope ratios in benthonic foraminifers related to test structure, mineralogy and environmental controls

NASA Astrophysics Data System (ADS)

Gussone, Nikolaus; Filipsson, Helena L.; Kuhnert, Henning

2016-01-01

We analysed Mg/Ca, Sr/Ca and Ca isotope ratios of benthonic foraminifers from sediment core tops retrieved during several research cruises in the Atlantic Ocean, in order to improve the understanding of isotope fractionation and element partitioning resulting from biomineralisation processes and changes in ambient conditions. Species include foraminifers secreting tests composed of hyaline low magnesium calcite, porcelaneous high magnesium calcite as well as aragonite. Our results demonstrate systematic isotope fractionation and element partitioning patterns specific for these foraminiferal groups. Calcium isotope fractionation is similar in porcelaneous and hyaline calcite tests and both groups demonstrate the previously described anomaly with enrichment of heavy isotopes around 3-4 °C (Gussone and Filipsson, 2010). Calcium isotope ratios of the aragonitic species Hoeglundina elegans, on the other hand, are about 0.4‰ lighter compared to the calcitic species, which is in general agreement with stronger fractionation in inorganic aragonite compared to calcite. However, the low and strongly variable Sr content suggests additional processes during test formation, and we propose that transmembrane ion transport or a precursor phase to aragonite may be involved. Porcelaneous tests, composed of high Mg calcite, incorporate higher amounts of Sr compared to hyaline low Mg calcite, in agreement with inorganic calcite systematics, but also porcelaneous tests with reduced Mg/Ca show high Sr/Ca. While calcium isotopes, Sr/Ca and Mg/Ca in benthonic foraminifers primarily appear to fractionate and partition with a dominant inorganic control, δ44/40Ca temperature and growth rate dependencies of benthonic foraminifer tests favour a dominant contribution of light Ca by transmembrane transport relative to unfractionated seawater Ca to the calcifying fluid, thus controlling the formation of foraminiferal δ44/40Ca and Sr/Ca proxy signals.

Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak

PubMed Central

Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.

2016-01-01

Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the

Calcium and aluminum cycling in a temperate broadleaved deciduous forest of the eastern USA: relative impacts of tree species, canopy state, and flux type.

PubMed

Levia, Delphis F; Shiklomanov, Alexey N; Van Stan, John T; Scheick, Carrie E; Inamdar, Shreeram P; Mitchell, Myron J; McHale, Patrick J

2015-07-01

Ca/Al molar ratios are commonly used to assess the extent of aluminum stress in forests. This is among the first studies to quantify Ca/Al molar ratios for stemflow. Ca/Al molar ratios in bulk precipitation, throughfall, stemflow, litter leachate, near-trunk soil solution, and soil water were quantified for a deciduous forest in northeastern MD, USA. Data were collected over a 3-year period. The Ca/Al molar ratios in this study were above the threshold for aluminum stress (<1). Fagus grandifolia Ehrh. (American beech) had a median annual stemflow Ca/Al molar ratio of 15.7, with the leafed and leafless values of 12.4 and 19.2, respectively. The corresponding Ca/Al molar ratios for Liriodendron tulipifera L. (yellow poplar) were 11.9 at the annual time scale and 11.9 and 13.6 for leafed and leafless periods, respectively. Bayesian statistical analysis showed no significant effect of canopy state (leafed, leafless) on Ca/Al molar ratios. DOC was consistently an important predictor of calcium, aluminum, and Ca/Al ratios. pH was occasionally an important predictor of calcium and aluminum concentrations, but was not a good predictor of Ca/Al ratio in any of the best-fit models (of >500 examined). This study supplies new data on Ca/Al molar ratios for stemflow from two common deciduous tree species. Future work should examine Ca/Al molar ratios in stemflow of other species and examine both inorganic and organic aluminum species to better gauge the potential for, and understand the dynamics of, aluminum toxicity in the proximal area around tree boles.

46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

Code of Federal Regulations, 2014 CFR

2014-10-01

... LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the... 46 Shipping 1 2014-10-01 2014-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7... Breakwater. (b) A line drawn from the outer end of Morro Bay Entrance East Breakwater to latitude 35°21.5′ N...

46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

Code of Federal Regulations, 2011 CFR

2011-10-01

... LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the... 46 Shipping 1 2011-10-01 2011-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7... Breakwater. (b) A line drawn from the outer end of Morro Bay Entrance East Breakwater to latitude 35°21.5′ N...

46 CFR 7.125 - Point Vincente, CA to Point Conception, CA.

Code of Federal Regulations, 2010 CFR

2010-10-01

... BOUNDARY LINES Pacific Coast § 7.125 Point Vincente, CA to Point Conception, CA. (a) A line drawn from Redondo Beach East Jetty Light “2” to Redondo Beach West Jetty Light “3”. (b) A line drawn from Marina Del... 46 Shipping 1 2010-10-01 2010-10-01 false Point Vincente, CA to Point Conception, CA. 7.125...

46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

Code of Federal Regulations, 2013 CFR

2013-10-01

... LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the... 46 Shipping 1 2013-10-01 2013-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7... Breakwater. (b) A line drawn from the outer end of Morro Bay Entrance East Breakwater to latitude 35°21.5′ N...

46 CFR 7.125 - Point Vincente, CA to Point Conception, CA.

Code of Federal Regulations, 2012 CFR

2012-10-01

... BOUNDARY LINES Pacific Coast § 7.125 Point Vincente, CA to Point Conception, CA. (a) A line drawn from Redondo Beach East Jetty Light “2” to Redondo Beach West Jetty Light “3”. (b) A line drawn from Marina Del... 46 Shipping 1 2012-10-01 2012-10-01 false Point Vincente, CA to Point Conception, CA. 7.125...

46 CFR 7.125 - Point Vincente, CA to Point Conception, CA.

Code of Federal Regulations, 2013 CFR

2013-10-01

... BOUNDARY LINES Pacific Coast § 7.125 Point Vincente, CA to Point Conception, CA. (a) A line drawn from Redondo Beach East Jetty Light “2” to Redondo Beach West Jetty Light “3”. (b) A line drawn from Marina Del... 46 Shipping 1 2013-10-01 2013-10-01 false Point Vincente, CA to Point Conception, CA. 7.125...

46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

Code of Federal Regulations, 2012 CFR

2012-10-01

... LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the... 46 Shipping 1 2012-10-01 2012-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7... Breakwater. (b) A line drawn from the outer end of Morro Bay Entrance East Breakwater to latitude 35°21.5′ N...

46 CFR 7.125 - Point Vincente, CA to Point Conception, CA.

Code of Federal Regulations, 2014 CFR

2014-10-01

... BOUNDARY LINES Pacific Coast § 7.125 Point Vincente, CA to Point Conception, CA. (a) A line drawn from Redondo Beach East Jetty Light “2” to Redondo Beach West Jetty Light “3”. (b) A line drawn from Marina Del... 46 Shipping 1 2014-10-01 2014-10-01 false Point Vincente, CA to Point Conception, CA. 7.125...

46 CFR 7.125 - Point Vincente, CA to Point Conception, CA.

Code of Federal Regulations, 2011 CFR

2011-10-01

... BOUNDARY LINES Pacific Coast § 7.125 Point Vincente, CA to Point Conception, CA. (a) A line drawn from Redondo Beach East Jetty Light “2” to Redondo Beach West Jetty Light “3”. (b) A line drawn from Marina Del... 46 Shipping 1 2011-10-01 2011-10-01 false Point Vincente, CA to Point Conception, CA. 7.125...

46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

Code of Federal Regulations, 2010 CFR

2010-10-01

... LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the... 46 Shipping 1 2010-10-01 2010-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7... Breakwater. (b) A line drawn from the outer end of Morro Bay Entrance East Breakwater to latitude 35°21.5′ N...

Characterization of Bacillus subtilis YfkE (ChaA): a calcium-specific Ca2+/H+ antiporter of the CaCA family.

PubMed

Fujisawa, Makoto; Wada, Yuko; Tsuchiya, Takahiro; Ito, Masahiro

2009-08-01

YfkE, a protein from Bacillus subtilis, exhibits homology to the Ca(2+):Cation Antiporter (CaCA) Family. In a fluorescence-based assay of everted membrane vesicles prepared from Na(+)(Ca(2+))/H(+) antiporter-defective mutant Escherichia coli KNabc, YfkE exhibited robust Ca(2+)/H(+) antiport activity, with a K (m) for Ca(2+) estimated at 12.5 muM at pH 8.5 and 113 muM at pH 7.5. Neither Na(+) nor K(+) served as a substrate. Mg(2+) also did not serve as a substrate, but inhibited the Ca(2+)/H(+) antiporter activity. The Ca(2+) transport capability of YfkE was also observed directly by transport assays in everted membrane vesicles using radiolabeled (45)Ca(2+). Transcriptional analysis from the putative yfkED operon using beta-garactosidase activity as a reporter revealed that both of the yfkE and yfkD genes are regulated by forespore-specific sigma factor, SigG, and the general stress response regulator, SigB. These results suggest that YfkE may be needed for Ca(2+) signaling in the sporulation or germination process in B. subtilis. ChaA is proposed as the designation for YfkE of B. subtilis.

National assessment of Tree City USA participation

EPA Pesticide Factsheets

Tree City USA is a national program that recognizes municipal commitment to community forestry. In return for meeting program requirements, Tree City USA participants expect social, economic, and/or environmental benefits. Understanding the geographic distribution and socioeconomic characteristics of Tree City USA communities at the national scale can offer insights into the motivations or barriers to program participation, and provide context for community forestry research at finer scales. In this study, researchers assessed patterns in Tree City USA participation for all U.S. communities with more than 2,500 people according to geography, community population size, and socioeconomic characteristics, such as income, education, and race. Nationally, 23.5% of communities studied were Tree City USA participants, and this accounted for 53.9% of the total population in these communities. Tree City USA participation rates varied substantially by U.S. region, but in each region participation rates were higher in larger communities, and long-term participants tended to be larger communities than more recent enrollees. In logistic regression models, owner occupancy rates were significant negative predictors of Tree City USA participation, education and percent white population were positive predictors in many U.S. regions, and inconsistent patterns were observed for income and population age. The findings indicate that communities with smaller populations, lower educat

Preliminary Reports, Memoranda and Technical Notes of the Materials Research Council Summer Conference, La Jolla, CA

DTIC Science & Technology

1975-07-01

1298 (1974); T. Wei, S. Etemad, A. F. Garito and A. J. Heeger, Phys. Lett. 4_5a 269 (1973). G. A. Vhomas, et. al .. Solid State Comm. 0£, 000...C. Beer, Eds. (Academic Press, New York 1975) Vol. 11 (to be published). H. Fetterman et al ., IEEE Trans. MTT-22, 1013 (1974) 8. A. H. Silver...increasing temperature over extensive ranges. Such measure- ments were reported by Johnston et al .?1 for the fast ionic conductor RbAgJ,. Thermal

PREFACE: Polycrystal Modelling with Experimental Integration: A Symposium Honoring Carlos Tomé (San Diego, CA, USA, February 27-March 3 2011) Polycrystal Modelling with Experimental Integration: A Symposium Honoring Carlos Tomé (San Diego, CA, USA, February 27-March 3 2011)

NASA Astrophysics Data System (ADS)

Lebensohn, Ricardo A.

2012-03-01

This special issue contains selected contributions from invited speakers to the 'Polycrystal Modelling with Experimental Integration: A Symposium Honoring Carlos Tomé', held as part of the 2011 TMS Annual Meeting and Exhibition, that took place on February 27-March 3, 2011 in San Diego, CA, USA. This symposium honored the remarkable contributions of Dr Carlos N Tomé to the field of mechanical behavior of polycrystalline materials, on the occasion of his 60th birthday. Throughout his career, Dr Tomé has pioneered the theoretical and numerical development of models of polycrystal mechanical behavior, with emphasis on the role played by texture and microstructure on the anisotropic behavior of engineering materials. His many contributions have been critical in establishing a strong connection between models and experiments, and in bridging different scales in the pursuit of robust multiscale models with experimental integration. Among his achievements, the numerical codes that Dr Tomé and co-workers have developed are extensively used in the materials science and engineering community as predictive tools for parameter identification, interpretation of experiments, and multiscale calculations in academia, national laboratories and industry. The symposium brought together materials scientists and engineers to address current theoretical, computational and experimental issues related to microstructure-property relationships in polycrystalline materials deforming in different regimes, including the effects of single crystal anisotropy, texture and microstructure evolution. Synergetic studies, involving different crystal plasticity-based models, including multiscale implementations of the latter, and measurements of global and local textures, internal strains, dislocation structures, twinning, phase distribution, etc, were discussed in more than 90 presentations. The papers in this issue are representative of the different length-scales, materials, and experimental and

Hydrogeologic Heterogeneity Enhances the Transfer of Salt Toward the High-Quality Deep Aquifers of the Western San Joaquin Valley (CA, USA)

NASA Astrophysics Data System (ADS)

Henri, C. V.; Harter, T.; Zhang, H.

2016-12-01

Increasing anthropogenic and drought stresses lead salinity to be of serious concern within regard to with the sustainability of regional groundwater quality. Agricultural basins of the Central Valley, CA (USA) are, and will continue to be, impacted by salinity issues in the coming future decades and or centuries. The aquifer system below the Western San Joaquin Valley is characterized by a shallow unconfined aquifer with high salinity overlying high quality semi-confined and deeper confined aquifers. A key challenge in the area is to predict if, when and how water traveling from the the low-quality shallow groundwater will reach and degrade the deeper semi-confined and confined aquifers. Previous studies, accounting for a simplified description of the aquifer hydraulic properties in their flow model, concluded that saline shallow groundwater would need 200-400 years to reach the semi-confined aquifer and 250-600 years to impact the deeper confined aquifer. However, well known heterogeneities in aquifer hydraulic properties significantly impact contaminant transport due to preferential flow paths and increased dispersion. Our study aims to (1) better understand the impact of heterogeneous hydraulic properties on the distribution of travel times from non-point source contamination, and (2) reassess the temporal scale of salt transfer into the deeper aquifers of the Western San Joaquin Valley. A detailed non-stationary geostatistical model was developed to describe the spatial variability of hydrofacies in great detail at the basin scale. The hydraulic properties corresponding to each hydrofacies are then calibrated in order to reproduce water fluxes previously modeled and calibrated. Subsequently, we use the random-walk particle tracking method to simulate the advective-dispersive transport of salt throughout the study area from a non-point source zone represented by the entire top layer of the model. The flux concentrations of solute crossing a series of monitoring

[CEA, CA-19-9 and il-8, sTNFRII and sil-2R in persons at high risk of colorectal cancer].

PubMed

Grotowski, Maciej; Wojtuń, Stanisław

2003-04-01

The aim of the study was to determine whether elevated concentrations of CEA, CA19-9, IL-8, sTNFRII and sIL-2R occur in persons at high risk of colorectal cancer. A group of 37 persons at high risk of colorectal cancer and 40 healthy subjects (control group) were included into this study. In both groups IL-8, sTNFRII and sIL-2R concentrations were measured by ELISA method (R&D Systems Minneapolis, USA). In the group of persons at high risk of colorectal cancer CEA and CA19-9 concentrations were determined using MEIA kits (Abbott Laboratories, USA). Using the 95th percentiles of the distribution in the control group the upper normal limits of IL-8, sTN-FRII and sIL-2R values were calculated. The cut-off value for CEA was 3 ng/ml and that for CA 19-9 was 37 U/ml. The incidence of elevated concentrations of the studied factors and concentrations of CEA and CA19-9 was compared. The association was assessed of elevated concentrations of the studied factors and CEA and CA19-9 with the results of histological examination of pathological changes in the colon and rectum. In the group of persons at high risk of colorectal cancer only CEA concentration was elevated in 2.7%. The percentages of persons with elevated concentrations of IL-8, sIL-2R and sTNFRII were 29.7, 8.1 and 18.9%, respectively. The percentage of persons with elevated concentrations of IL-8 and sTNFRII was higher in comparison with the percentage of persons with elevated concentrations of CEA and CA19-9 (p < 0.05). Pathological lesions in the colon and rectum were detected in 16 persons (43.2%). High-grade dysplasia was detected in 11 cases. Elevated concentration of IL-8 always accompanied high-grade dysplasia in ulcerative colitis. The concentrations of IL-8 were significantly higher in high-grade dysplasia (23.7 pg/ml, SD +/- 7.53) than in cases of its absence (18.9 pg/ml, SD +/- 3.53) (p < 0.05). The obtained results of preliminary studies with IL-8 in persons at high risk of colorectal cancer require a

USA National Phenology Network gridded products documentation

USGS Publications Warehouse

Crimmins, Theresa M.; Marsh, R. Lee; Switzer, Jeff R.; Crimmins, Michael A.; Gerst, Katharine L.; Rosemartin, Alyssa H.; Weltzin, Jake F.

2017-02-23

The goals of the USA National Phenology Network (USA-NPN, www.usanpn.org) are to advance science, inform decisions, and communicate and connect with the public regarding phenology and species’ responses to environmental variation and climate change. The USA-NPN seeks to facilitate informed ecosystem stewardship and management by providing phenological information freely and openly. One way the USA-NPN is endeavoring to accomplish these goals is by providing data and data products in a wide range of formats, including gridded real-time, short-term forecasted, and historical maps of phenological events, patterns and trends. This document describes the suite of gridded phenologically relevant data products produced and provided by the USA National Phenology Network, which can be accessed at www.usanpn.org/data/phenology_maps and also through web services at geoserver.usanpn.org/geoserver/wms?request=GetCapabilities.

The influence of Ca²⁺ buffers on free [Ca²⁺] fluctuations and the effective volume of Ca²⁺ microdomains.

PubMed

Weinberg, Seth H; Smith, Gregory D

2014-06-17

Intracellular calcium (Ca(2+)) plays a significant role in many cell signaling pathways, some of which are localized to spatially restricted microdomains. Ca(2+) binding proteins (Ca(2+) buffers) play an important role in regulating Ca(2+) concentration ([Ca(2+)]). Buffers typically slow [Ca(2+)] temporal dynamics and increase the effective volume of Ca(2+) domains. Because fluctuations in [Ca(2+)] decrease in proportion to the square-root of a domain's physical volume, one might conjecture that buffers decrease [Ca(2+)] fluctuations and, consequently, mitigate the significance of small domain volume concerning Ca(2+) signaling. We test this hypothesis through mathematical and computational analysis of idealized buffer-containing domains and their stochastic dynamics during free Ca(2+) influx with passive exchange of both Ca(2+) and buffer with bulk concentrations. We derive Langevin equations for the fluctuating dynamics of Ca(2+) and buffer and use these stochastic differential equations to determine the magnitude of [Ca(2+)] fluctuations for different buffer parameters (e.g., dissociation constant and concentration). In marked contrast to expectations based on a naive application of the principle of effective volume as employed in deterministic models of Ca(2+) signaling, we find that mobile and rapid buffers typically increase the magnitude of domain [Ca(2+)] fluctuations during periods of Ca(2+) influx, whereas stationary (immobile) Ca(2+) buffers do not. Also contrary to expectations, we find that in the absence of Ca(2+) influx, buffers influence the temporal characteristics, but not the magnitude, of [Ca(2+)] fluctuations. We derive an analytical formula describing the influence of rapid Ca(2+) buffers on [Ca(2+)] fluctuations and, importantly, identify the stochastic analog of (deterministic) effective domain volume. Our results demonstrate that Ca(2+) buffers alter the dynamics of [Ca(2+)] fluctuations in a nonintuitive manner. The finding that Ca(2

Ventral tegmental area disruption selectively affects CA1/CA2 but not CA3 place fields during a differential reward working memory task

PubMed Central

Martig, Adria K; Mizumori, Sheri JY

2010-01-01

Hippocampus (HPC) receives dopaminergic (DA) projections from the ventral tegmental area (VTA) and substantia nigra. These inputs appear to provide a modulatory signal that influences HPC dependent behaviors and place fields. We examined how efferent projections from VTA to HPC influence spatial working memory and place fields when the reward context changes. CA1 and CA3 process environmental context changes differently and VTA preferentially innervates CA1. Given these anatomical data and electrophysiological evidence that implicates DA in reward processing, we predicted that CA1 place fields would respond more strongly to both VTA disruption and changes in the reward context than CA3 place fields. Rats (N=9) were implanted with infusion cannula targeting VTA and recording tetrodes aimed at HPC. Then they were tested on a differential reward, win-shift working memory task. One recording session consisted of 5 baseline and 5 manipulation trials during which place cells in CA1/CA2 (N=167) and CA3 (N=94) were recorded. Prior to manipulation trials rats were infused with either baclofen or saline and then subjected to control or reward conditions during which the learned locations of large and small reward quantities were reversed. VTA disruption resulted in an increase in errors, and in CA1/CA2 place field reorganization. There were no changes in any measures of CA3 place field stability during VTA disruption. Reward manipulations did not affect performance or place field stability in CA1/CA2 or CA3; however, changes in the reward locations “rescued” performance and place field stability in CA1/CA2 when VTA activity was compromised, perhaps by trigging compensatory mechanisms. These data support the hypothesis that VTA contributes to spatial working memory performance perhaps specifically by maintaining place field stability selectively in CA1/CA2. PMID:20082295

Calcium-activated K(+) channel (K(Ca)3.1) activity during Ca(2+) store depletion and store-operated Ca(2+) entry in human macrophages.

PubMed

Gao, Ya-dong; Hanley, Peter J; Rinné, Susanne; Zuzarte, Marylou; Daut, Jurgen

2010-07-01

STIM1 'senses' decreases in endoplasmic reticular (ER) luminal Ca(2+) and induces store-operated Ca(2+) (SOC) entry through plasma membrane Orai channels. The Ca(2+)/calmodulin-activated K(+) channel K(Ca)3.1 (previously known as SK4) has been implicated as an 'amplifier' of the Ca(2+)-release activated Ca(2+) (CRAC) current, especially in T lymphocytes. We have previously shown that human macrophages express K(Ca)3.1, and here we used the whole-cell patch-clamp technique to investigate the activity of these channels during Ca(2+) store depletion and store-operated Ca(2+) influx. Using RT-PCR, we found that macrophages express the elementary CRAC channel components Orai1 and STIM1, as well as Orai2, Orai3 and STIM2, but not the putatively STIM1-activated channels TRPC1, TRPC3-7 or TRPV6. In whole-cell configuration, a robust Ca(2+)-induced outwardly rectifying K(+) current inhibited by clotrimazole and augmented by DC-EBIO could be detected, consistent with K(Ca)3.1 channel current (also known as intermediate-conductance IK1). Introduction of extracellular Ca(2+) following Ca(2+) store depletion via P2Y(2) receptors induced a robust charybdotoxin (CTX)- and 2-APB-sensitive outward K(+) current and hyperpolarization. We also found that SOC entry induced by thapsigargin treatment induced CTX-sensitive K(+) current in HEK293 cells transiently expressing K(Ca)3.1. Our data suggest that SOC and K(Ca)3.1 channels are tightly coupled, such that a small Ca(2+) influx current induces a much large K(Ca)3.1 channel current and hyperpolarization, providing the necessary electrochemical driving force for prolonged Ca(2+) signaling and store repletion. Copyright 2010 Elsevier Ltd. All rights reserved.

Ca2+-induced Ca2+ Release Phenomena in Mammalian Sympathetic Neurons Are Critically Dependent on the Rate of Rise of Trigger Ca2+

PubMed Central

Hernández-Cruz, Arturo; Escobar, Ariel L.; Jiménez, Nicolás

1997-01-01

The role of ryanodine-sensitive intracellular Ca2+ stores present in nonmuscular cells is not yet completely understood. Here we examine the physiological parameters determining the dynamics of caffeine-induced Ca2+ release in individual fura-2–loaded sympathetic neurons. Two ryanodine-sensitive release components were distinguished: an early, transient release (TR) and a delayed, persistent release (PR). The TR component shows refractoriness, depends on the filling status of the store, and requires caffeine concentrations ≥10 mM. Furthermore, it is selectively suppressed by tetracaine and intracellular BAPTA, which interfere with Ca2+-mediated feedback loops, suggesting that it constitutes a Ca2+-induced Ca2+-release phenomenon. The dynamics of release is markedly affected when Sr2+ substitutes for Ca2+, indicating that Sr2+ release may operate with lower feedback gain than Ca2+ release. Our data indicate that when the initial release occurs at an adequately fast rate, Ca2+ triggers further release, producing a regenerative response, which is interrupted by depletion of releasable Ca2+ and Ca2+-dependent inactivation. A compartmentalized linear diffusion model can reproduce caffeine responses: When the Ca2+ reservoir is full, the rapid initial Ca2+ rise determines a faster occupation of the ryanodine receptor Ca2+ activation site giving rise to a regenerative release. With the store only partially loaded, the slower initial Ca2+ rise allows the inactivating site of the release channel to become occupied nearly as quickly as the activating site, thereby suppressing the initial fast release. The PR component is less dependent on the store's Ca2+ content. This study suggests that transmembrane Ca2+ influx in rat sympathetic neurons does not evoke widespread amplification by CICR because of its inability to raise [Ca2+] near the Ca2+ release channels sufficiently fast to overcome their Ca2+-dependent inactivation. Conversely, caffeine-induced Ca2+ release can

Allometric constraints on Sr/Ca and Ba/Ca partitioning in terrestrial mammalian trophic chains.

PubMed

Balter, Vincent

2004-03-01

In biological systems, strontium (Sr) and barium (Ba) are two non-essential elements, in comparison to calcium (Ca) which is essential. The Sr/Ca and Ba/Ca ratios tend to decrease in biochemical pathways which include Ca as an essential element, and these processes are termed biopurification of Ca. The quantitative pathway of the biopurification of Ca in relation to Sr and Ba between two biological reservoirs ( Rn and R(n -1)) is measured with an observed ratio (OR) expressed by the (Sr/Ca) Rn /(Sr/Ca)( Rn-1) and (Ba/Ca) Rn /(Ba/Ca)( Rn-1) ratios. For a mammalian organism, during the whole biopurification of Ca starting with the diet to the ultimate reservoir of Ca which is the bone, the mean values for ORSr and ORBa are 0.25 and 0.2, respectively. In this study, published Sr/Ca and Ba/Ca ratios are used for three sets of soils, plants, and bones of herbivorous and carnivorous mammals, each comprising a trophic chain, to illustrate the biopurification of Ca at the level of trophic chains. Calculated ORSr and ORBa of herbivore bones in relation to plants and of bones of carnivores in relation to bones of herbivores give ORSr=0.30+/-0.08 and ORBa=0.16+/-0.08, thus suggesting that trophic chains reflect the Sr/Ca and Ba/Ca fluxes that are prevalent at the level of a mammalian organism. The slopes of the three regression equations of log(Sr/Ca) vs. log(Ba/Ca) are similar, indicating that the process of biopurification of Ca with respect to Sr and Ba is due to biological processes and is independent of the geological settings. Modifications of the logarithmic expression of the Sr/Ca and Ba/Ca relationship allow a new formula of the biopurification process to be deduced, leading to the general equation ORBa=ORSr(1.79+/-0.33), where the allometric coefficient is the mean of the slopes of the three regression equations. Some recent examples are used to illustrate this new analysis of predator-prey relations between mammals. This opens up new possibilities for the

Ca2+ signalling, voltage-gated Ca2+ channels and praziquantel in flatworm neuromusculature.

PubMed

Greenberg, R M

2005-01-01

Transient changes in calcium (Ca2+) levels regulate a wide variety of cellular processes, and cells employ both intracellular and extracellular sources of Ca2+ for signalling. Praziquantel, the drug of choice against schistosomiasis, disrupts Ca2+ homeostasis in adult worms. This review will focus on voltage-gated Ca2+ channels, which regulate levels of intracellular Ca2+ by coupling membrane depolarization to entry of extracellular Ca2+. Ca2+ channels are members of the ion channel superfamily and represent essential components of neurons, muscles and other excitable cells. Ca2+ channels are membrane protein complexes in which the pore-forming alpha1 subunit is modulated by auxiliary subunits such as beta and alpha2delta. Schistosomes express two Ca2+ channel beta subunit subtypes: a conventional subtype similar to beta subunits found in other vertebrates and invertebrates and a novel variant subtype with unusual structural and functional properties. The variant schistosome beta subunit confers praziquantel sensitivity to an otherwise praziquantel-insensitive mammalian Ca2+ channel, implicating it as a mediator of praziquantel action.

Imperforate hymen with elevated serum CA 125 and CA 19-9 levels.

PubMed

Sak, Muhammet Erdal; Evsen, Mehmet Siddik; Soydinc, Hatice Ender; Sak, Sibel; Yalinkaya, Ahmet

2013-01-01

To report the clinical characteristics of 14 patients with imperforate hymen and their levels of tumor markers (CA 19-9 and CA 125). Fourteen patients with imperforate hymen who followed-up between September 2006 and September 2010 in the Department of Obstetrics and Gynecology, Dicle University School of Medicine, Diyarbakir, Turkey, were evaluated retrospectively. The clinical features and the management of the patients are discussed. The mean age of the patients was 13.8 years. All patients had primary amenorrhea and pelvic pain. The most common clinical symptoms were cryptomenorrhea in 14 patients, pelvic pain in 11, palpable abdominal mass in 6, voiding difficulties in 7, and defecation problems in 2. In 6 patients with palpable pelvic mass, the mean + standard deviation values of tumor markers were as follows: CA 125, 84.0 +/- 23.7 and CA 19-9, 162 +/- 189. One week after surgery we measured CA 125 and CA 19-9 levels once again. The postoperative mean CA 125 level was 13.8 +/- 3.6, and the mean postoperative CA 19-9 level was 17.5 +/- 3.5. Preoperative levels of CA 125 and CA 19-9 were significantly higher than those of the postoperative period (p < 0.001 for both comparisons). Six patients were treated by T-shaped incision and 8 patients by a central surgical incision through the hymenal membrane. Diagnosis of imperforate hymen is very important before undergoing surgery in a different clinic. Many patients have seen several doctors before receiving a clear diagnosis and have had tumor markers evaluated because the presence of pelvic mass in patients suggests the possibility of a gynecologic malignancy. Imperforate hymen is one of the benign conditions that increase serum CA 125 and CA 19-9 levels and which is not listed in the classical medical textbooks. These markers are not needed for the diagnosis.

Ca2+-independent Activation of Ca2+/Calmodulin-dependent Protein Kinase II Bound to the C-terminal Domain of CaV2.1 Calcium Channels*

PubMed Central

Magupalli, Venkat G.; Mochida, Sumiko; Yan, Jin; Jiang, Xin; Westenbroek, Ruth E.; Nairn, Angus C.; Scheuer, Todd; Catterall, William A.

2013-01-01

Ca2+/calmodulin-dependent protein kinase II (CaMKII) forms a major component of the postsynaptic density where its functions in synaptic plasticity are well established, but its presynaptic actions are poorly defined. Here we show that CaMKII binds directly to the C-terminal domain of CaV2.1 channels. Binding is enhanced by autophosphorylation, and the kinase-channel signaling complex persists after dephosphorylation and removal of the Ca2+/CaM stimulus. Autophosphorylated CaMKII can bind the CaV2.1 channel and synapsin-1 simultaneously. CaMKII binding to CaV2.1 channels induces Ca2+-independent activity of the kinase, which phosphorylates the enzyme itself as well as the neuronal substrate synapsin-1. Facilitation and inactivation of CaV2.1 channels by binding of Ca2+/CaM mediates short term synaptic plasticity in transfected superior cervical ganglion neurons, and these regulatory effects are prevented by a competing peptide and the endogenous brain inhibitor CaMKIIN, which blocks binding of CaMKII to CaV2.1 channels. These results define the functional properties of a signaling complex of CaMKII and CaV2.1 channels in which both binding partners are persistently activated by their association, and they further suggest that this complex is important in presynaptic terminals in regulating protein phosphorylation and short term synaptic plasticity. PMID:23255606

Effect of Ca2+ Efflux Pathway Distribution and Exogenous Ca2+ Buffers on Intracellular Ca2+ Dynamics in the Rat Ventricular Myocyte: A Simulation Study

PubMed Central

Šimurda, Jiří; Orchard, Clive H.

2014-01-01

We have used a previously published computer model of the rat cardiac ventricular myocyte to investigate the effect of changing the distribution of Ca2+ efflux pathways (SERCA, Na+/Ca2+ exchange, and sarcolemmal Ca2+ ATPase) between the dyad and bulk cytoplasm and the effect of adding exogenous Ca2+ buffers (BAPTA or EGTA), which are used experimentally to differentially buffer Ca2+ in the dyad and bulk cytoplasm, on cellular Ca2+ cycling. Increasing the dyadic fraction of a particular Ca2+ efflux pathway increases the amount of Ca2+ removed by that pathway, with corresponding changes in Ca2+ efflux from the bulk cytoplasm. The magnitude of these effects varies with the proportion of the total Ca2+ removed from the cytoplasm by that pathway. Differences in the response to EGTA and BAPTA, including changes in Ca2+-dependent inactivation of the L-type Ca2+ current, resulted from the buffers acting as slow and fast “shuttles,” respectively, removing Ca2+ from the dyadic space. The data suggest that complex changes in dyadic Ca2+ and cellular Ca2+ cycling occur as a result of changes in the location of Ca2+ removal pathways or the presence of exogenous Ca2+ buffers, although changing the distribution of Ca2+ efflux pathways has relatively small effects on the systolic Ca2+ transient. PMID:24971358

Pericellular Ca2+ recycling potentiates thrombin-evoked Ca2+ signals in human platelets

PubMed Central

Sage, Stewart O; Pugh, Nicholas; Farndale, Richard W; Harper, Alan G S

2013-01-01

We have previously demonstrated that Na+/Ca2+ exchangers (NCXs) potentiate Ca2+ signaling evoked by thapsigargin in human platelets, via their ability to modulate the secretion of autocoids from dense granules. This link was confirmed in platelets stimulated with the physiological agonist, thrombin, and experiments were performed to examine how Ca2+ removal by the NCX modulates platelet dense granule secretion. In cells loaded with the near-membrane indicator FFP-18, thrombin stimulation was observed to elicit an NCX-dependent accumulation of Ca2+ in a pericellular region around the platelets. To test whether this pericellular Ca2+ accumulation might be responsible for the influence of NCXs over platelet function, platelets were exposed to fast Ca2+ chelators or had their glycocalyx removed. Both manipulations of the pericellular Ca2+ rise reduced thrombin-evoked Ca2+ signals and dense granule secretion. Blocking Ca2+-permeable ion channels had a similar effect, suggesting that Ca2+ exported into the pericellular region is able to recycle back into the platelet cytosol. Single cell imaging with extracellular Fluo-4 indicated that thrombin-evoked rises in extracellular [Ca2+] occurred within the boundary described by the cell surface, suggesting their presence within the open canalicular system (OCS). FFP-18 fluorescence was similarly distributed. These data suggest that upon thrombin stimulation, NCX activity creates a rise in [Ca2+] within the pericellular region of the platelet from where it recycles back into the platelet cytosol, acting to both accelerate dense granule secretion and maintain the initial rise in cytosolic [Ca2+]. PMID:24303163

Potentiation of inositol trisphosphate-induced Ca2+ mobilization in Xenopus oocytes by cytosolic Ca2+.

PubMed Central

Yao, Y; Parker, I

1992-01-01

1. The ability of cytosolic Ca2+ ions to modulate inositol 1,4,5-trisphosphate (Insp3)-induced Ca2+ liberation from intracellular stores was studied in Xenopus oocytes using light flash photolysis of caged InsP3. Changes in cytosolic free Ca2+ level were effected by inducing Ca2+ entry through ionophore and voltage-gated plasma membrane channels and by injection of Ca2+ through a micropipette. Their effects on Ca2+ liberation were monitored by video imaging of Fluo-3 fluorescence and by voltage clamp recording of Ca(2+)-activated membrane Cl- currents. 2. Treatment of oocytes with the Ca2+ ionophores A23187 and ionomycin caused a transient elevation of cytosolic Ca2+ level when cells were bathed in Ca(2+)-free solution, which probably arose because of release of Ca2+ from intracellular stores. 3. Membrane current and Fluo-3 Ca2+ signals evoked by photoreleased InsP3 in ionophore-treated oocytes were potentiated when the intracellular Ca2+ level was elevated by raising the Ca2+ level in the bathing solution. 4. Responses to photoreleased InsP3 were similarly potentiated following activation of Ca2+ entry through voltage-gated Ca2+ channels expressed in the plasma membrane. 5. Ca(2+)-activated membrane currents evoked by depolarization developed a delayed 'hump' component during sustained photorelease of InsP3, probably because Ca2+ ions entering through the membrane channels triggered liberation of Ca2+ from intracellular stores. 6. Ba2+ and Sr2+ ions were able to substitute for Ca2+ in potentiating InsP3-mediated Ca2+ liberation. 7. Gradual photorelease of InsP3 by weak photolysis light evoked Ca2+ liberation that began at particular foci and then propagated throughout, but not beyond that area of the oocyte exposed to the light. Local elevations of intracellular Ca2+ produced by microinjection of Ca2+ acted as new foci for the initiation of Ca2+ liberation by InsP3. 8. In resting oocytes, intracellular injections of Ca2+ resulted only in localized elevation of

76 FR 2947 - Notice of Final Federal Agency Actions on Proposed Highway in California

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-18

...) from State Route 52 (SR-52) to La Jolla Village Drive. Two high occupancy vehicle (HOV) lanes (one in each direction) from La Jolla Village Drive to just north of Mira Mesa Boulevard (Blvd). The project.... Pending Federal actions include: 401 Water Quality Certification from the Regional Water Quality Control...

Thresholds in Soil Mineral Weathering and Relation to Streamwater Chemistry in Glaciated Catchments of the Northeastern USA

NASA Astrophysics Data System (ADS)

Bailey, S. W.; Ross, D. S.

2015-12-01

Primary mineral dissolution (i.e. weathering) is a critical process in forested catchments as an important consumer of acidity and CO2, the principle source of nutrients such as Ca, K, and P, as well as the source of toxic cations such as Al. Two common limitations of weathering studies are inadequate determination of mineralogic composition and insufficient sampling depth to determine location and advancement of weathering reactions. We determined mineral stocks through EPMA mapping of Al, Ca, Fe, P, and Si content of soil samples and development of an image analysis routine that assigned mineral composition based on the content of these five elements. Portions of the classified maps were confirmed by optical petrography and full elemental analysis by SEM-EDS. Samples were analyzed for soil profiles >2m depth (~1.5m past the upper boundary of the "unweathered" C horizon). Study sites spanned a range of weatherability found in catchments in glaciated northeastern USA including Winnisook, NY (sandstone parent material, 100 ppm Ca), Hubbard Brook, NH (granite, 0.9% Ca), and Sleepers River, VT (calcareous granulite, 3.5% Ca). All profiles exhibited a weathering front, or threshold above which the most reactive minerals (calcite, apatite) have been depleted. However, in all cases this threshold was below the rooting zone, and in many profiles, it was well below the C horizon interface. Catchment scale Ca exports reflect this deeper weathering source while rooting zone exchangeable Ca was highly variable, probably reflecting spatial patterns of hydrologic flowpaths which bring deeper weathering products to the surface only in certain landscape positions. These results suggest that nutrient cycling and critical loads models, which assume that ecologically relevant weathering is confined to the rooting zone, need to be refined to account for deeper weathering and spatial patterns of lateral and upward hydrologic fluxes. Similarly, recovery from cultural acidification may

Ionizing radiation regulates cardiac Ca handling via increased ROS and activated CaMKII.

PubMed

Sag, Can M; Wolff, Hendrik A; Neumann, Kay; Opiela, Marie-Kristin; Zhang, Juqian; Steuer, Felicia; Sowa, Thomas; Gupta, Shamindra; Schirmer, Markus; Hünlich, Mark; Rave-Fränk, Margret; Hess, Clemens F; Anderson, Mark E; Shah, Ajay M; Christiansen, Hans; Maier, Lars S

2013-11-01

Ionizing radiation (IR) is an integral part of modern multimodal anti-cancer therapies. IR involves the formation of reactive oxygen species (ROS) in targeted tissues. This is associated with subsequent cardiac dysfunction when applied during chest radiotherapy. We hypothesized that IR (i.e., ROS)-dependently impaired cardiac myocytes' Ca handling might contribute to IR-dependent cardiocellular dysfunction. Isolated ventricular mouse myocytes and the mediastinal area of anaesthetized mice (that included the heart) were exposed to graded doses of irradiation (sham 4 and 20 Gy) and investigated acutely (after ~1 h) as well as chronically (after ~1 week). IR induced a dose-dependent effect on myocytes' systolic function with acutely increased, but chronically decreased Ca transient amplitudes, which was associated with an acutely unaltered but chronically decreased sarcoplasmic reticulum (SR) Ca load. Likewise, in vivo echocardiography of anaesthetized mice revealed acutely enhanced left ventricular contractility (strain analysis) that declined after 1 week. Irradiated myocytes showed persistently increased diastolic SR Ca leakage, which was acutely compensated by an increase in SR Ca reuptake. This was reversed in the chronic setting in the face of slowed relaxation kinetics. As underlying cause, acutely increased ROS levels were identified to activate Ca/calmodulin-dependent protein kinase II (CaMKII). Accordingly, CaMKII-, but not PKA-dependent phosphorylation sites of the SR Ca release channels (RyR2, at Ser-2814) and phospholamban (at Thr-17) were found to be hyperphosphorylated following IR. Conversely, ROS-scavenging as well as CaMKII-inhibition significantly attenuated CaMKII-activation, disturbed Ca handling, and subsequent cellular dysfunction upon irradiation. Targeted cardiac irradiation induces a biphasic effect on cardiac myocytes Ca handling that is associated with chronic cardiocellular dysfunction. This appears to be mediated by increased oxidative

Proton Beam Fast Ignition Fusion: Synergy of Weibel and Rayleigh-Taylor Instabilities

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2011-04-01

The proton beam generation and focusing in fast ignition inertial confinement fusion is studied. The spatial and energy spread of the proton beam generated in a laser-solid interaction is increased due to the synergy of Weibel and Rayleigh-Taylor instabilities. The focal spot radius can reach 100 μm, which is nearly an order of magnitude larger than the optimal value. The energy spread decreases the beam deposition energy in the focal spot. Under these conditions, ignition of a precompressed DT fuel is achieved with the beam powers much higher than the values presently in consideration. Work supported in part by NIKOLA TESLA Laboratories (Stefan University), La Jolla, CA.

Concentrations and ratios of Sr, Ba and Ca along an estuarine river to the Gulf of Mexico - implication for sea level rise effects on trace metal distribution

NASA Astrophysics Data System (ADS)

He, S.; Xu, Y. J.

2015-11-01

Strontium and barium to calcium ratios are often used as proxies for tracking animal movement across salinity gradients. As sea level rise continues, many estuarine rivers in the world face saltwater intrusion, which may cause changes in mobility and distribution of these metals upstream. Despite intensive research on metal adsorption and desorption in marine systems, knowledge of the spatiotemporal distribution of these elements along estuarine rivers is still limited. In this study, we conducted an intensive monitoring of Sr and Ba dynamics along an 88 km long estuary, the Calcasieu River in South Louisiana, USA, which has been strongly affected by saltwater intrusion. Over the period from May 2013 to August 2015, we collected monthly water samples and performed in-situ water quality measurements at six sites from the upstream to the river mouth, with a salinity range from 0.02 to 29.50 ppt. Water samples were analyzed for Sr, Ba, and Ca concentrations. In-situ measurements were made on salinity, pH, water temperature, dissolved oxygen concentration, and specific conductance. We found that the Sr and Ca concentrations and the Sr / Ca ratio all increased significantly with increasing salinity. The average Sr concentration at the site closest to the Gulf of Mexico (site 6) was 46.21 μmol L-1, which was about 130 times higher than that of the site furthest upstream (site 1, 0.35 μmol L-1). The average Ca concentration at site 6 was 8.19 mmol L-1, which was about 60 times higher than that of site 1 (0.13 mmol L-1). The average Sr / Ca ratio at site 6 (8.41 mmol mol-1) was about 3 times the average Sr / Ca ratio at site 1 (2.89 mmol mol-1). However, the spatial variation in Ba concentration was marginal, varying from 0.36 μmol L-1 at site 6 to 0.47 at site 5. The average Ba / Ca ratio at site 1 (4.82 mmol mol-1) was about 54 times the average Ba / Ca ratio at site 6 (0.09 mmol mol-1), showing a clear negative relation between the Ba / Ca ratio and increasing

Phosphatidylinositol-Specific Phospholipase C Contributes to Survival of Staphylococcus aureus USA300 in Human Blood and Neutrophils

PubMed Central

White, Mark J.; Boyd, Jeffrey M.

2014-01-01

Staphylococcus aureus is an important human pathogen that employs a large repertoire of secreted virulence factors to promote disease pathogenesis. Many strains of S. aureus possess a plc gene that encodes a phosphatidylinositol (PI)-specific phospholipase C (PI-PLC) capable of hydrolyzing PI and cleaving glycosyl-PI (GPI)-linked proteins from cell surfaces. Despite being secreted by virulent staphylococci, the contribution of PI-PLC to the capacity of S. aureus to cause disease remains undefined. Our goal in these studies was to understand PI-PLC in the context of S. aureus biology. Among a collection of genetically diverse clinical isolates of S. aureus, community-associated methicillin-resistant S. aureus (CA-MRSA) USA300 secreted the most PI-PLC. Screening a collection of two-component system (TCS) mutants of S. aureus, we identified both the agr quorum-sensing system and the SrrAB TCS to be positive regulators of plc gene expression. Real-time PCR and PI-PLC enzyme assays of the TCS mutants, coupled with SrrA promoter binding studies, demonstrated that SrrAB was the predominant transcriptional activator of plc. Furthermore, plc regulation was linked to oxidative stress both in vitro and in vivo in a SrrAB-dependent manner. A Δplc mutant in a CA-MRSA USA300 background exhibited a survival defect in human whole blood and in isolated neutrophils. However, the same mutant strain displayed no survival defect in murine models of infection or murine whole blood. Overall, these data identify potential links between bacterial responses to the host innate immune system and to oxidative stress and suggest how PI-PLC could contribute to the pathogenesis of S. aureus infections. PMID:24452683

β-Adrenergic stimulation increases the intra-sarcoplasmic reticulum Ca2+ threshold for Ca2+ wave generation

PubMed Central

Domeier, Timothy L; Maxwell, Joshua T; Blatter, Lothar A

2012-01-01

β-Adrenergic signalling induces positive inotropic effects on the heart that associate with pro-arrhythmic spontaneous Ca2+ waves. A threshold level of sarcoplasmic reticulum (SR) Ca2+ ([Ca2+]SR) is necessary to trigger Ca2+ waves, and whether the increased incidence of Ca2+ waves during β-adrenergic stimulation is due to an alteration in this threshold remains controversial. Using the low-affinity Ca2+ indicator fluo-5N entrapped within the SR of rabbit ventricular myocytes, we addressed this controversy by directly monitoring [Ca2+]SR and Ca2+ waves during β-adrenergic stimulation. Electrical pacing in elevated extracellular Ca2+ ([Ca2+]o= 7 mm) was used to increase [Ca2+]SR to the threshold where Ca2+ waves were consistently observed. The β-adrenergic agonist isoproterenol (ISO; 1 μm) increased [Ca2+]SR well above the control threshold and consistently triggered Ca2+ waves. However, when [Ca2+]SR was subsequently lowered in the presence of ISO (by lowering [Ca2+]o to 1 mm and partially inhibiting sarcoplasmic/endoplasmic reticulum calcium ATPase with cyclopiazonic acid or thapsigargin), Ca2+ waves ceased to occur at a [Ca2+]SR that was higher than the control threshold. Furthermore, for a set [Ca2+]SR level the refractoriness of wave occurrence (Ca2+ wave latency) was prolonged during β-adrenergic stimulation, and was highly dependent on the extent that [Ca]SR exceeded the wave threshold. These data show that acute β-adrenergic stimulation increases the [Ca2+]SR threshold for Ca2+ waves, and therefore the primary cause of Ca2+ waves is the robust increase in [Ca2+]SR above this higher threshold level. Elevation of the [Ca2+]SR wave threshold and prolongation of wave latency represent potentially protective mechanisms against pro-arrhythmogenic Ca2+ release during β-adrenergic stimulation. PMID:22988136

Successful control of nosocomial transmission of the USA300 clone of community-acquired meticillin-resistant Staphylococcus aureus in a UK paediatric burns centre.

PubMed

Patel, M; Thomas, H C; Room, J; Wilson, Y; Kearns, A; Gray, J

2013-08-01

An outbreak of the PVL-positive USA300 clone of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) occurred in a UK paediatric burns centre from January to February 2010. Four patients, two staff members and one family member of a patient were affected. The outbreak strain had similar antibiotic susceptibilities to other MRSA seen in the hospital, and was only identified when a patient and a staff member presented simultaneously with skin infections. Infection control measures included screening and decolonization of staff and patients, environmental sampling and enhanced cleaning. Isolation of the outbreak strain from an asymptomatic staff member and the environment demonstrates the potential for CA-MRSA to survive and become endemic in UK hospitals. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

78 FR 39769 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... Chautauqua Blvd., Los Angeles, 13000513 Community Clubhouse, 1200 N. Vista St., West Hollywood, 13000510... Study House No. 23A, (Case Study House Program MPS) 2342 Rue de Anne, La Jolla, 13000520 Case Study House No. 23C, (Case Study House Program MPS) 2339 Rue de Anne, La Jolla, 13000521 Ventura County Case...

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

Attendees of the USA Science and Engineering Festival explore all of the exhibits at the NASA Stage. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

F-actin-based Ca signaling-a critical comparison with the current concept of Ca signaling.

PubMed

Lange, Klaus; Gartzke, Joachim

2006-11-01

A short comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect, the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating endoplasmic/sarcoplasmic reticulum-derived vesicles equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive channel-receptors for Ca-release. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of actin filaments. Cellular sites of F-actin-based Ca storage are microvilli and the submembrane cytoskeleton. Several specific features of Ca signaling such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release (CICR), which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. Copyright 2006 Wiley-Liss, Inc.

Suppression of Sleep Spindle Rhythmogenesis in Mice with Deletion of CaV3.2 and CaV3.3 T-type Ca(2+) Channels.

PubMed

Pellegrini, Chiara; Lecci, Sandro; Lüthi, Anita; Astori, Simone

2016-04-01

Low-threshold voltage-gated T-type Ca(2+) channels (T-channels or CaV3 channels) sustain oscillatory discharges of thalamocortical (TC) and nucleus Reticularis thalami (nRt) cells. The CaV3.3 subtype dominates nRt rhythmic bursting and mediates a substantial fraction of spindle power in the NREM sleep EEG. CaV3.2 channels are also found in nRt, but whether these contribute to nRt-dependent spindle generation is unexplored. We investigated thalamic rhythmogenesis in mice lacking this subtype in isolation (CaV3.2KO mice) or in concomitance with CaV3.3 deletion (CaV3.double-knockout (DKO) mice). We examined discharge characteristics of thalamic cells and intrathalamic evoked synaptic transmission in brain slices from wild-type, CaV3.2KO and CaV3.DKO mice through patch-clamp recordings. The sleep profile of freely behaving CaV3.2KO and CaV3.DKO mice was assessed by polysomnographic recordings. CaV3.2 channel deficiency left nRt discharge properties largely unaltered, but additional deletion of CaV3.3 channels fully abolished low-threshold whole-cell Ca(2+) currents and bursting, and suppressed burst-mediated inhibitory responses in TC cells. CaV3.DKO mice had more fragmented sleep, with shorter NREM sleep episodes and more frequent microarousals. The NREM sleep EEG power spectrum displayed a relative suppression of the σ frequency band (10-15 Hz), which was accompanied by an increase in the δ band (1-4 Hz). Consistent with previous findings, CaV3.3 channels dominate nRt rhythmogenesis, but the lack of CaV3.2 channels further aggravates neuronal, synaptic, and EEG deficits. Therefore, CaV3.2 channels can boost intrathalamic synaptic transmission, and might play a modulatory role adjusting the relative presence of NREM sleep EEG rhythms. © 2016 Associated Professional Sleep Societies, LLC.

Measurement of mitochondrial Ca2+ transport mediated by three transport proteins: VDAC1, the Na+/Ca2+ exchanger, and the Ca2+ uniporter.

PubMed

Ben-Hail, Danya; Palty, Raz; Shoshan-Barmatz, Varda

2014-02-01

Ca(2+) is a ubiquitous cellular signal, with changes in intracellular Ca(2+) concentration not only stimulating a number of intercellular events but also triggering cell death pathways, including apoptosis. Mitochondrial Ca(2+) uptake and release play pivotal roles in cellular physiology by regulating intracellular Ca(2+) signaling, energy metabolism and cell death. Ca(2+) transport across the inner and outer mitochondrial membranes is mediated by several proteins, including channels, antiporters, and a uniporter. In this article, we present the background to several methods now established for assaying mitochondrial Ca(2+) transport activity across both mitochondrial membranes. The first of these is Ca(2+) transport mediated by the outer mitochondrial protein, the voltage-dependent anion-selective channel protein 1 (VDAC1, also known as porin 1), both as a purified protein reconstituted into a planar lipid bilayer (PLB) or into liposomes and as a mitochondrial membrane-embedded protein. The second method involves isolated mitochondria for assaying the activity of an inner mitochondrial membrane transport protein, the mitochondrial Ca(2+) uniporter (MCU) that transports Ca(2+) and is powered by the steep mitochondrial membrane potential. In the event of Ca(2+) overload, this leads to opening of the mitochondrial permeability transition pore (MPTP) and cell death. The third method describes how Na(+)-dependent mitochondrial Ca(2+) efflux mediated by mitochondrial NCLX, a member of the Na(+)/Ca(2+) exchanger superfamily, can be assayed in digitonin-permeabilized HEK-293 cells. The Ca(2+)-transport assays can be performed under various conditions and in combination with inhibitors, allowing detailed characterization of the transport activity of interest.

Assays of mitochondrial Ca2+ transport and Ca2+ efflux via the MPTP.

PubMed

Ben-Hail, Danya; Shoshan-Barmatz, Varda

2014-02-01

Studying Ca(2+) transport in mitochondria in connection with energy production, as well as cell death, is of great importance. Ca(2+) activates several key enzymes in the mitochondrial matrix to enhance ATP production. This provides an important mechanism for synchronizing energy production with the energy demands of Ca(2+)-activated processes, such as contraction, allowing important feedback effects to help shape cytosolic Ca(2+) signals. A rise in mitochondrial Ca(2+) can convey both apoptotic and necrotic death signals by inducing opening of the mitochondrial permeability transition pore (MPTP). Here, we present a protocol for measuring Ca(2+) transport and release in isolated mitochondria.

77 FR 76006 - Star Networks USA, LLC; Complaint

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

... CONSUMER PRODUCT SAFETY COMMISSION [CPSC Docket No. 13-2] Star Networks USA, LLC; Complaint AGENCY.... Published below is a Complaint: In the Matter of Star Networks USA, LLC.\\1\\ \\1\\ Chairman Inez M. Tenenbaum... COMMISSION In the Matter of STAR NETWORKS USA, LLC, Respondent CPSC DOCKET NO. 13-2 COMPLAINT Nature of...

Domain model for Ca2(+)-inactivation of Ca2+ channels at low channel density.

PubMed Central

Sherman, A; Keizer, J; Rinzel, J

1990-01-01

The "shell" model for Ca2(+)-inactivation of Ca2+ channels is based on the accumulation of Ca2+ in a macroscopic shell beneath the plasma membrane. The shell is filled by Ca2+ entering through open channels, with the elevated Ca2+ concentration inactivating both open and closed channels at a rate determined by how fast the shell is filled. In cells with low channel density, the high concentration Ca2+ "shell" degenerates into a collection of nonoverlapping "domains" localized near open channels. These domains form rapidly when channels open and disappear rapidly when channels close. We use this idea to develop a "domain" model for Ca2(+)-inactivation of Ca2+ channels. In this model the kinetics of formation of an inactivated state resulting from Ca2+ binding to open channels determines the inactivation rate, a mechanism identical with that which explains single-channel recordings on rabbit-mesenteric artery Ca2+ channels (Huang Y., J. M. Quayle, J. F. Worley, N. B. Standen, and M. T. Nelson. 1989. Biophys. J. 56:1023-1028). We show that the model correctly predicts five important features of the whole-cell Ca2(+)-inactivation for mouse pancreatic beta-cells (Plants, T. D. 1988. J. Physiol. 404:731-747) and that Ca2(+)-inactivation has only minor effects on the bursting electrical activity of these cells. PMID:2174274

High-pressure transitions of diopside and wollastonite: phase equilibria and thermochemistry of CaMgSi 2O 6, CaSiO 3 and CaSi 2O 5-CaTiSiO 5 system

NASA Astrophysics Data System (ADS)

Akaogi, M.; Yano, M.; Tejima, Y.; Iijima, M.; Kojitani, H.

2004-06-01

Phase transitions of CaMgSi 2O 6 diopside and CaSiO 3 wollastonite were examined at pressures to 23 GPa and temperatures to 2000 °C, using a Kawai-type multiavil apparatus. Enthalpies of high-pressure phases in CaSiO 3 and in the CaSi 2O 5-CaTiSiO 5 system were also measured by high-temperature calorimetry. At 17-18 GPa, diopside dissociates to CaSiO 3-rich perovskite + Mg-rich (Mg,Ca)SiO 3 tetragonal garnet (Gt) above about 1400 °C. The solubilities of CaSiO 3 in garnet and MgSiO 3 in perovskite increase with temperature. At 17-18 GPa below about 1400 °C, diopside dissociates to Ca-perovskite + β-Mg 2SiO 4 + stishovite. The Mg, Si-phases coexisting with Ca-perovskite change to γ-Mg 2SiO 4 + stishovite, to ilmenite, and finally to Mg-perovskite with increasing pressure. CaSiO 3 wollastonite transforms to the walstromite structure, and further dissociates to Ca 2SiO 4 larnite + CaSi 2O 5 titanite. The latter transition occurs at 9-11 GPa with a positive Clapeyron slope. At 1600 °C, larnite + titanite transform to CaSiO 3 perovskite at 14.6±0.6 GPa, calibrated against the α-β transition pressure of Mg 2SiO 4. The enthalpies of formation of CaSiO 3 walstromite and CaSi 2O 5 titanite from the mixture of CaO and SiO 2 quartz at 298 K have been determined as -76.1±2.8, and -27.8±2.1 kJ/mol, respectively. The latter was estimated from enthalpy measurements of titanite solid solutions in the system CaSi 2O 5-CaTiSiO 5, because CaSi 2O 5 titanite transforms to a triclinic phase upon decompression. The enthalpy difference between titanite and the triclinic phase is only 1.5±4.8 kJ/mol. Using these enthalpies of formation and those of larnite and CaSiO 3 perovskite, the transition boundaries in CaSiO 3 have been calculated. The calculated boundaries for the wollastonite-walstromite-larnite + titanite transitions are consistent with the experimental determinations within the errors. The calculated boundary between larnite + titanite and Ca-perovskite has a slope of

Suppression of Sleep Spindle Rhythmogenesis in Mice with Deletion of CaV3.2 and CaV3.3 T-type Ca2+ Channels

PubMed Central

Pellegrini, Chiara; Lecci, Sandro; Lüthi, Anita; Astori, Simone

2016-01-01

Study Objectives: Low-threshold voltage-gated T-type Ca2+ channels (T-channels or CaV3 channels) sustain oscillatory discharges of thalamocortical (TC) and nucleus Reticularis thalami (nRt) cells. The CaV3.3 subtype dominates nRt rhythmic bursting and mediates a substantial fraction of spindle power in the NREM sleep EEG. CaV3.2 channels are also found in nRt, but whether these contribute to nRt-dependent spindle generation is unexplored. We investigated thalamic rhythmogenesis in mice lacking this subtype in isolation (CaV3.2KO mice) or in concomitance with CaV3.3 deletion (CaV3.double-knockout (DKO) mice). Methods: We examined discharge characteristics of thalamic cells and intrathalamic evoked synaptic transmission in brain slices from wild-type, CaV3.2KO and CaV3.DKO mice through patch-clamp recordings. The sleep profile of freely behaving CaV3.2KO and CaV3.DKO mice was assessed by polysomnographic recordings. Results: CaV3.2 channel deficiency left nRt discharge properties largely unaltered, but additional deletion of CaV3.3 channels fully abolished low-threshold whole-cell Ca2+ currents and bursting, and suppressed burst-mediated inhibitory responses in TC cells. CaV3.DKO mice had more fragmented sleep, with shorter NREM sleep episodes and more frequent microarousals. The NREM sleep EEG power spectrum displayed a relative suppression of the σ frequency band (10–15 Hz), which was accompanied by an increase in the δ band (1–4 Hz). Conclusions: Consistent with previous findings, CaV3.3 channels dominate nRt rhythmogenesis, but the lack of CaV3.2 channels further aggravates neuronal, synaptic, and EEG deficits. Therefore, CaV3.2 channels can boost intrathalamic synaptic transmission, and might play a modulatory role adjusting the relative presence of NREM sleep EEG rhythms. Citation: Pellegrini C, Lecci S, Lüthi A, Astori S. Suppression of sleep spindle rhythmogenesis in mice with deletion of Cav3.2 and Cav3.3 T-type Ca2+ channels. SLEEP 2016;39(4):875�

77 FR 27082 - StarTek USA, Inc., 244 Dundee Avenue, Greeley, CO; StarTek USA, Inc., 1250 H Street, Greeley, CO...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-08

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,850; TA-W-74,850A] StarTek USA, Inc., 244 Dundee Avenue, Greeley, CO; StarTek USA, Inc., 1250 H Street, Greeley, CO; Amended... workers and former workers of StarTek USA, Inc., Greeley, Colorado. The Department's notice of...

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival uses marbles to build a universe consisting of atoms and dark matter. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Radioisotope tracer studies of inorganic carbon and Ca in microbially derived CaCO3

USGS Publications Warehouse

Yates, Kimberly K.; Robbins, Lisa L.

1999-01-01

Microbial calcification significantly impacts the cycling and deposition of inorganic carbon. This research employs 45Ca and 14C techniques as radioisotopic tracers to examine the role of cellular cycling of Ca2+ and inorganic carbon in CaCO3 precipitation by the unicellular green alga Nannochloris atomus. Implications of the effects of these physiological aspects on CaCO3 precipitation and the effects of microbial calcification on CaCO3 δ13C ratios are discussed. Results from pulse/chase experiments indicate that intracellular Ca2+ is incorporated into extracellular CaCO3. Intracellular inorganic carbon leaks from cells within 10 to 12 s after injection of unlabelled NaHCO3, providing a source of inorganic carbon for extracellular CaCO3. Cellular expulsion of calcium plays a key role in increasing the CaCO3 saturation state at the site of calcification. The δ13C ratios of microbial carbonates may vary depending on the amount of photorespiratory CO2 incorporated.

Thermoluminescence Response of CaF2:Mn, CaFz:Dy and CaSO4:Tm to Protons and Alpha-Particles,

DTIC Science & Technology

1987-06-01

TLD ) in diverse radiation fields, such as mixed neutron-gamma fields. TL responses of the detector may depend not only on the photon and neutron energy...response of three TLD materials: CaF 2 :Mn, CaF?:Dy and CaSO 4 :Tm. These three materials are commonly used in TLDs , because of their high sensitivities...and suitable readout temperatures. CaS04:Tm powder embedded in polyethylene was investiaged at DREO (Ref. (4)) as a combined neutron/gamma TLD , but

USA National Phenology Network observational data documentation

USGS Publications Warehouse

Rosemartin, Alyssa H.; Denny, Ellen G.; Gerst, Katharine L.; Marsh, R. Lee; Posthumus, Erin E.; Crimmins, Theresa M.; Weltzin, Jake F.

2018-04-25

The goals of the USA National Phenology Network (USA-NPN, www.usanpn.org) are to advance science, inform decisions, and communicate and connect with the public regarding phenology and species’ responses to environmental variation and climate change. The USA-NPN seeks to advance the science of phenology and facilitate ecosystem stewardship by providing phenological information freely and openly. To accomplish these goals, the USA-NPN National Coordinating Office (NCO) delivers observational data on plant and animal phenology in several formats, including minimally processed status and intensity datasets and derived phenometrics for individual plants, sites, and regions. This document describes the suite of observational data products delivered by the USA National Phenology Network, covering the period 2009–present for the United States and accessible via the Phenology Observation Portal (http://dx.doi.org/10.5066/F78S4N1V) and via an Application Programming Interface. The data described here have been used in diverse research and management applications, including over 30 publications in fields such as remote sensing, plant evolution, and resource management.

The role of luminal Ca2+ in the generation of Ca2+ waves in rat ventricular myocytes

PubMed Central

Lukyanenko, Valeriy; Subramanian, Saisunder; Györke, Inna; Wiesner, Theodore F; Györke, Sandor

1999-01-01

We used confocal Ca2+ imaging and fluo-3 to investigate the transition of localized Ca2+ releases induced by focal caffeine stimulation into propagating Ca2+ waves in isolated rat ventricular myocytes. Self-sustaining Ca2+ waves could be initiated when the cellular Ca2+ load was increased by elevating the extracellular [Ca2+] ([Ca2+]o) and they could also be initiated at normal Ca2+ loads when the sensitivity of the release sites to cytosolic Ca2+ was enhanced by low doses of caffeine. When we prevented the accumulation of extra Ca2+ in the luminal compartment of the sarcoplasmic reticulum (SR) with thapsigargin, focal caffeine pulses failed to trigger self-sustaining Ca2+ waves on elevation of [Ca2+]o. Inhibition of SR Ca2+ uptake by thapsigargin in cells already preloaded with Ca2+ above normal levels did not prevent local Ca2+ elevations from triggering propagating waves. Moreover, wave velocity increased by 20 %. Tetracaine (0·75 mM) caused transient complete inhibition of both local and propagating Ca2+ signals, followed by full recovery of the responses due to increased SR Ca2+ accumulation. Computer simulations using a numerical model with spatially distinct Ca2+ release sites suggested that increased amounts of releasable Ca2+ might not be sufficient to generate self-sustaining Ca2+ waves under conditions of Ca2+ overload unless the threshold of release site Ca2+ activation was set at relatively low levels (< 1·5 μM). We conclude that the potentiation of SR Ca2+ release channels by luminal Ca2+ is an important factor in Ca2+ wave generation. Wave propagation does not require the translocation of Ca2+ from the spreading wave front into the SR. Instead, it relies on luminal Ca2+ sensitizing Ca2+ release channels to cytosolic Ca2+. PMID:10373699

Fidelity of the Sr/Ca proxy in recording ocean temperature in the western Atlantic coral Siderastrea siderea

USGS Publications Warehouse

Kuffner, Ilsa B.; Roberts, Kelsey E.; Flannery, Jennifer A.; Morrison, Jennifer M.; Richey, Julie

2017-01-01

Massive corals provide a useful archive of environmental variability, but careful testing of geochemical proxies in corals is necessary to validate the relationship between each proxy and environmental parameter throughout the full range of conditions experienced by the recording organisms. Here we use samples from a coral-growth study to test the hypothesis that Sr/Ca in the coral Siderastrea siderea accurately records sea-surface temperature (SST) in the subtropics (Florida, USA) along 350 km of reef tract. We test calcification rate, measured via buoyant weight, and linear extension (LE) rate, estimated with Alizarin Red-S staining, as predictors of variance in the Sr/Ca records of 39 individual S. siderea corals grown at four outer-reef locations next to in-situ temperature loggers during two, year-long periods. We found that corals with calcification rates < 1.7 mg cm−2 d−1 or < 1.7 mm yr−1 LE returned spuriously high Sr/Ca values, leading to a cold-bias in Sr/Ca-based SST estimates. The threshold-type response curves suggest that extension rate can be used as a quality-control indicator during sample and drill-path selection when using long cores for SST paleoreconstruction. For our corals that passed this quality control step, the Sr/Ca-SST proxy performed well in estimating mean annual temperature across three sites spanning 350 km of the Florida reef tract. However, there was some evidence that extreme temperature stress in 2010 (cold snap) and 2011 (SST above coral-bleaching threshold) may have caused the corals not to record the temperature extremes. Known stress events could be avoided during modern calibrations of paleoproxies.

Testing the fidelity of the Sr/Ca proxy in recording ocean temperature in a western Atlantic coral

NASA Astrophysics Data System (ADS)

Kuffner, I. B.; Roberts, K.; Flannery, J. A.; Richey, J. N.; Morrison, J. M.

2017-12-01

Massive corals provide a useful archive of environmental variability, but careful testing of geochemical proxies in corals is necessary to validate the relationship between each proxy and environmental parameter throughout the full range of conditions experienced by the recording organisms. Here we use samples from a field-based coral-growth study to test the hypothesis that Sr/Ca in the coral Siderastrea siderea accurately records sea-surface temperature (SST) in the subtropics (Florida, USA) along 350 km of reef tract. We test calcification rate, measured via buoyant weight, and linear extension (LE) rate, estimated with Alizarin Red-S staining, as predictors of variance in the Sr/Ca records of 39 individual S. siderea corals grown at four outer-reef locations next to in-situ temperature loggers during two, year-long periods. We found that corals with calcification rates less than 1.7 mg cm-2 d-1 or LE rates less than 1.7 mm yr-1 returned spuriously high Sr/Ca values, leading to a cold bias in Sr/Ca-based SST estimates. The threshold-type response curves suggest that LE rate can be used as a quality-control indicator during sample and microdrill-path selection when using long cores for SST paleoreconstruction. For our corals that passed this quality control step, the Sr/Ca-SST proxy performed well in estimating mean annual SST across three sites spanning 350 km of the Florida reef tract. However, there was some evidence that extreme temperature stress in 2010 (cold snap) and 2011 (SST above coral-bleaching threshold) may have caused the corals not to record the temperature extremes. Known stress events could be avoided during modern calibrations of paleoproxies.

Arabidopsis transcriptional response to extracellular Ca2+ depletion involves a transient rise in cytosolic Ca2+.

PubMed

Wang, Jing; Tergel, Tergel; Chen, Jianhua; Yang, Ju; Kang, Yan; Qi, Zhi

2015-02-01

Ecological evidence indicates a worldwide trend of dramatically decreased soil Ca(2+) levels caused by increased acid deposition and massive timber harvesting. Little is known about the genetic and cellular mechanism of plants' responses to Ca(2+) depletion. In this study, transcriptional profiling analysis helped identify multiple extracellular Ca(2+) ([Ca(2+) ]ext ) depletion-responsive genes in Arabidopsis thaliana L., many of which are involved in response to other environmental stresses. Interestingly, a group of genes encoding putative cytosolic Ca(2+) ([Ca(2+) ]cyt ) sensors were significantly upregulated, implying that [Ca(2+) ]cyt has a role in sensing [Ca(2+) ]ext depletion. Consistent with this observation, [Ca(2+) ]ext depletion stimulated a transient rise in [Ca(2+) ]cyt that was negatively influenced by [K(+) ]ext , suggesting the involvement of a membrane potential-sensitive component. The [Ca(2+) ]cyt response to [Ca(2+) ]ext depletion was significantly desensitized after the initial treatment, which is typical of a receptor-mediated signaling event. The response was insensitive to an animal Ca(2+) sensor antagonist, but was suppressed by neomycin, an inhibitor of phospholipase C. Gd(3+) , an inhibitor of Ca(2+) channels, suppressed the [Ca(2+) ]ext -triggered rise in [Ca(2+) ]cyt and downstream changes in gene expression. Taken together, this study demonstrates that [Ca(2+) ]cyt plays an important role in the putative receptor-mediated cellular and transcriptional response to [Ca(2+) ]ext depletion of plant cells. © 2014 Institute of Botany, Chinese Academy of Sciences.

The diagnostic value of serum tumor markers CEA, CA19-9, CA125, CA15-3, and TPS in metastatic breast cancer.

PubMed

Wang, Weigang; Xu, Xiaoqin; Tian, Baoguo; Wang, Yan; Du, Lili; Sun, Ting; Shi, Yanchun; Zhao, Xianwen; Jing, Jiexian

2017-07-01

This study aims to understand the diagnostic value of serum tumor markers carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9), cancer antigen 125 (CA125), cancer antigen 15-3 (CA15-3), and tissue polypeptide-specific antigen (TPS) in metastatic breast cancer (MBC). A total of 164 metastatic breast cancer patients in Shanxi Cancer Hospital were recruited between February 2016 and July 2016. 200 breast cancer patients without metastasis in the same period were randomly selected as the control group. The general characteristics, immunohistochemical, and pathological results were investigated between the two groups, and tumor markers were determined. There were statistical differences in the concentration and the positive rates of CEA, CA19-9, CA125, CA15-3, and TPS between the MBC and control group (P<0.05). The highest sensitivity was in CEA and the highest specificity was in CA125 for the diagnosis of MBC when using a single tumor marker at 56.7% and 97.0%, respectively. In addition, two tumor markers were used for the diagnosis of MBC and the CEA and TPS combination had the highest diagnostic sensitivity with 78.7%, while the CA15-3 and CA125 combination had the highest specificity of 91.5%. Analysis of tumor markers of 164 MBC found that there were statistical differences in the positive rates of CEA and CA15-3 between bone metastases and other metastases (χ 2 =6.00, P=0.014; χ 2 =7.32, P=0.007, respectively). The sensitivity and specificity values of the CEA and CA15-3 combination in the diagnosis of bone metastases were 77.1% and 45.8%, respectively. The positive rate of TPS in the lung metastases group was lower than in other metastases (χ 2 =8.06, P=0.005).There were significant differences in the positive rates of CA15-3 and TPS between liver metastases and other metastases (χ 2 =15.42, P<0.001; χ 2 =9.72, P=0.002, respectively). The sensitivity and specificity of the CA15-3 and TPS combination in the diagnosis of liver metastases were 92.3% and

The CaV2.3 R-type voltage-gated Ca2+ channel in mouse sleep architecture.

PubMed

Siwek, Magdalena Elisabeth; Müller, Ralf; Henseler, Christina; Broich, Karl; Papazoglou, Anna; Weiergräber, Marco

2014-05-01

Voltage-gated Ca(2+) channels (VGCCs) are key elements in mediating thalamocortical rhythmicity. Low-voltage activated (LVA) CaV 3 T-type Ca(2+) channels have been related to thalamic rebound burst firing and to generation of non-rapid eye movement (NREM) sleep. High-voltage activated (HVA) CaV 1 L-type Ca(2+) channels, on the opposite, favor the tonic mode of action associated with higher levels of vigilance. However, the role of the HVA Non-L-type CaV2.3 Ca(2+) channels, which are predominantly expressed in the reticular thalamic nucleus (RTN), still remains unclear. Recently, CaV2.3(-/-) mice were reported to exhibit altered spike-wave discharge (SWD)/absence seizure susceptibility supported by the observation that CaV2.3 mediated Ca(2+) influx into RTN neurons can trigger small-conductance Ca(2+)-activated K(+)-channel type 2 (SK2) currents capable of maintaining thalamic burst activity. Based on these studies we investigated the role of CaV2.3 R-type Ca(2+) channels in rodent sleep. The role of CaV2.3 Ca(2+) channels was analyzed in CaV2.3(-/-) mice and controls in both spontaneous and artificial urethane-induced sleep, using implantable video-EEG radiotelemetry. Data were analyzed for alterations in sleep architecture using sleep staging software and time-frequency analysis. CaV2.3 deficient mice exhibited reduced wake duration and increased slow-wave sleep (SWS). Whereas mean sleep stage durations remained unchanged, the total number of SWS epochs was increased in CaV2.3(-/-) mice. Additional changes were observed for sleep stage transitions and EEG amplitudes. Furthermore, urethane-induced SWS mimicked spontaneous sleep results obtained from CaV2.3 deficient mice. Quantitative Real-time PCR did not reveal changes in thalamic CaV3 T-type Ca(2+) channel expression. The detailed mechanisms of SWS increase in CaV2.3(-/-) mice remain to be determined. Low-voltage activated CaV2.3 R-type Ca(2+) channels in the thalamocortical loop and extra

Stimulation-evoked Ca2+ signals in astrocytic processes at hippocampal CA3-CA1 synapses of adult mice are modulated by glutamate and ATP.

PubMed

Tang, Wannan; Szokol, Karolina; Jensen, Vidar; Enger, Rune; Trivedi, Chintan A; Hvalby, Øivind; Helm, P Johannes; Looger, Loren L; Sprengel, Rolf; Nagelhus, Erlend A

2015-02-18

To date, it has been difficult to reveal physiological Ca(2+) events occurring within the fine astrocytic processes of mature animals. The objective of the study was to explore whether neuronal activity evokes astrocytic Ca(2+) signals at glutamatergic synapses of adult mice. We stimulated the Schaffer collateral/commissural fibers in acute hippocampal slices from adult mice transduced with the genetically encoded Ca(2+) indicator GCaMP5E driven by the glial fibrillary acidic protein promoter. Two-photon imaging revealed global stimulation-evoked astrocytic Ca(2+) signals with distinct latencies, rise rates, and amplitudes in fine processes and somata. Specifically, the Ca(2+) signals in the processes were faster and of higher amplitude than those in the somata. A combination of P2 purinergic and group I/II metabotropic glutamate receptor (mGluR) antagonists reduced the amplitude of the Ca(2+) transients by 30-40% in both astrocytic compartments. Blockage of the mGluRs alone only modestly reduced the magnitude of the stimulation-evoked Ca(2+) signals in processes and failed to affect the somatic Ca(2+) response. Local application of group I or I/II mGluR agonists or adenosine triphosphate (ATP) elicited global astrocytic Ca(2+) signals that mimicked the stimulation-evoked astrocytic Ca(2+) responses. We conclude that stimulation-evoked Ca(2+) signals in astrocytic processes at CA3-CA1 synapses of adult mice (1) differ from those in astrocytic somata and (2) are modulated by glutamate and ATP. Copyright © 2015 the authors 0270-6474/15/353016-06$15.00/0.

New anticancer drug candidates sulfonamides as selective hCA IX or hCA XII inhibitors.

PubMed

Gul, Halise Inci; Yamali, Cem; Sakagami, Hiroshi; Angeli, Andrea; Leitans, Janis; Kazaks, Andris; Tars, Kaspars; Ozgun, Dilan Ozmen; Supuran, Claudiu T

2018-04-01

In this study, new 4-[3-(aryl)-5-substitutedphenyl-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamides (19-36) were synthesized and evaluated their cytotoxic/anticancer and CA inhibitory effects. According to results obtained, the compounds 34 (4-[5-(2,3,4-trimethoxyphenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-yl] benzensulfonamide, Potency-Selectivity Expression (PSE) = 141) and 36 (4-[5-(3,4,5-trimethoxyphenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamide, PSE = 54.5) were found the leader anticancer compounds with the highest PSE values. In CA inhibitory studies, the compounds 36 and 24 (4-[5-(3,4,5-trimethoxyphenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamide) were found the leader CA inhibitors depending on selectivity ratios. The compound 36 was a selective inhibitor of hCA XII isoenzyme (hCA I/hCA XII = 1250 and hCA II/hCA XII = 224) while the compound 24 was a selective inhibitor of hCA IX isoenzyme (hCA I/hCA IX = 161 and hCA II/hCA IX = 177). The compounds 24, 34, and 36 can be considered to develop new anticancer drug candidates. Copyright © 2018 Elsevier Inc. All rights reserved.

Calmodulin antagonists have differential effects on Ca/sup 2 +/ uptake, (Ca/sup 2 +/ + Mg/sup 2 +/)-ATPase and Ca/sup 2 +/ release in hepatic endoplasmic reticulum

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

Delfert, D.M.; Koepnick, S.; McDonald, J.M.

1986-05-01

The effect of calmodulin (CaM) antagonists on Ca/sup 2 +/ handling by hepatic endoplasmic reticulum (ER) was studied. Ca/sup 2 +/ uptake by saponin-permeabilized hepatocytes or isolated ER was measured using /sup 45/Ca/sup 2 +/ in a filtration assay in the presence of 0.09 ..mu..M free (Ca/sup 2 +/) and inhibitors of mitochondrial Ca/sup 2 +/ transport. Each CaM-antagonist (chlorpromazine, CPZ; trifluoperazine, TFP; calmidazolium, W7 and 48/80) showed a dose-dependent inhibition of Ca/sup 2 +/ accumulation in permeabilized hepatocytes. Both the initial rate and steady state values for Ca/sup 2 +/ uptake were reduced by 50% with 40 ..mu..M calmidazolium,more » 100 ..mu..M TFP, 150..mu..M W7, 150 ..mu..M CPZ and 300 ..mu..M 48/80. Using isolated ER both calmidazolium (20 ..mu..M) and W7 (150 ..mu..M) inhibited the initial rate and steady state level of Ca/sup 2 +/ accumulation. At this concentration calmidazolium inhibited the initial rate of (Ca/sup 2 +/ + Mg/sup 2 +/)-ATPase activity, and enhanced Ca/sup 2 +/ release. In contrast, W7 had no effect on these parameters. These results suggest that the reduced level of Ca/sup 2 +/ uptake into ER vesicles in the presence of calmidazolium may result from inhibition of the (Ca/sup 2 +/ + Mg/sup 2 +/)-ATPase as well as induction of Ca/sup 2 +/ release, while W7 may act to uncouple Ca/sup 2 +/ transport from its (Ca/sup 2 +/ + Mg/sup 2 +/)-ATPase counterpart.« less

Ca. Nitrososphaera and Bradyrhizobium are inversely correlated and related to agricultural practices in long-term field experiments

PubMed Central

Zhalnina, Kateryna; de Quadros, Patricia D.; Gano, Kelsey A.; Davis-Richardson, Austin; Fagen, Jennie R.; Brown, Christopher T.; Giongo, Adriana; Drew, Jennifer C.; Sayavedra-Soto, Luis A.; Arp, Dan J.; Camargo, Flavio A. O.; Daroub, Samira H.; Clark, Ian M.; McGrath, Steve P.; Hirsch, Penny R.; Triplett, Eric W.

2013-01-01

Agricultural land management, such as fertilization, liming, and tillage affects soil properties, including pH, organic matter content, nitrification rates, and the microbial community. Three different study sites were used to identify microorganisms that correlate with agricultural land use and to determine which factors regulate the relative abundance of the microbial signatures of the agricultural land-use. The three sites included in this study are the Broadbalk Experiment at Rothamsted Research, UK, the Everglades Agricultural Area, Florida, USA, and the Kellogg Biological Station, Michigan, USA. The effects of agricultural management on the abundance and diversity of bacteria and archaea were determined using high throughput, barcoded 16S rRNA sequencing. In addition, the relative abundance of these organisms was correlated with soil features. Two groups of microorganisms involved in nitrogen cycle were highly correlated with land use at all three sites. The ammonia oxidizing-archaea, dominated by Ca. Nitrososphaera, were positively correlated with agriculture while a ubiquitous group of soil bacteria closely related to the diazotrophic symbiont, Bradyrhizobium, was negatively correlated with agricultural management. Analysis of successional plots showed that the abundance of ammonia oxidizing-archaea declined and the abundance of bradyrhizobia increased with time away from agriculture. This observation suggests that the effect of agriculture on the relative abundance of these genera is reversible. Soil pH and NH3 concentrations were positively correlated with archaeal abundance but negatively correlated with the abundance of Bradyrhizobium. The high correlations of Ca. Nitrososphaera and Bradyrhizobium abundances with agricultural management at three long-term experiments with different edaphoclimatic conditions allowed us to suggest these two genera as signature microorganisms for agricultural land use. PMID:23641242

Intracellular Ca2+ release and Ca2+ influx during regulatory volume decrease in IMCD cells.

PubMed

Tinel, H; Wehner, F; Sauer, H

1994-07-01

Volume changes and cytosolic Ca2+ concentration ([Ca2+]i) of inner medullary collecting duct (IMCD) cells under hypotonic stress were monitored by means of confocal laser scanning microscopy and fura 2 fluorescence, respectively. Reduction of extracellular osmolality from 600 to 300 mosmol/kgH2O by omission of sucrose led to an increase in cell volume within 1 min to 135 +/- 3% (n = 9), followed by a partial regulatory volume decrease (RVD) to 109 +/- 2% (n = 9) within the ensuring 5 min. In parallel, [Ca2+]i rose from 145 +/- 9 to 433 +/- 16 nmol/l (n = 9) and thereafter reached a lower steady state of 259 +/- 9 nmol/l. Under low-Ca2+ conditions (10 nmol/l) RVD was not impeded and reduction of osmolality evoked only a transient increase of [Ca2+]i by 182 +/- 22 nmol/l (n = 6). Preincubation with 100 mumol/l 8-(N,N-diethylamino)octyl-3,4,5-trimethoxy-benzoate hydrochloride (TMB-8) or 20 mmol/l caffeine, both effective inhibitors of Ca2+ release from intracellular stores, in low Ca2+ as well as in high Ca2+, inhibited the Ca2+ response and abolished RVD. The temporal relationship between Ca2+ release from intracellular stores and Ca2+ entry was analyzed by determining fura 2 quenching, using Mn2+ as a substitute for external Ca2+. Intracellular Ca2+ release preceded Mn2+ influx by 17 +/- 3 s (n = 10). Mn2+ influx persisted during the whole period of exposure to hypotonicity, indicating that there is no time-dependent Ca2+ channel inactivation. Preincubation with TMB-8 or caffeine reduced Mn2+ influx to the control level, indicating that activation of Ca2+ channels in the plasma membrane occurs via intracellular Ca2+ release.(ABSTRACT TRUNCATED AT 250 WORDS)

Ca2+-dependent rapid Ca2+ sensitization of contraction in arterial smooth muscle.

PubMed

Dimopoulos, George J; Semba, Shingo; Kitazawa, Kazuyo; Eto, Masumi; Kitazawa, Toshio

2007-01-05

Ca(2+) ion is a universal intracellular messenger that regulates numerous biological functions. In smooth muscle, Ca(2+) with calmodulin activates myosin light chain (MLC) kinase to initiate a rapid MLC phosphorylation and contraction. To test the hypothesis that regulation of MLC phosphatase is involved in the rapid development of MLC phosphorylation and contraction during Ca(2+) transient, we compared Ca(2+) signal, MLC phosphorylation, and 2 modes of inhibition of MLC phosphatase, phosphorylation of CPI-17 Thr38 and MYPT1 Thr853, during alpha(1) agonist-induced contraction with/without various inhibitors in intact rabbit femoral artery. Phenylephrine rapidly induced CPI-17 phosphorylation from a negligible amount to a peak value of 0.38+/-0.04 mol of Pi/mol within 7 seconds following stimulation, similar to the rapid time course of Ca(2+) rise and MLC phosphorylation. This rapid CPI-17 phosphorylation was dramatically inhibited by either blocking Ca(2+) release from the sarcoplasmic reticulum or by pretreatment with protein kinase C inhibitors, suggesting an involvement of Ca(2+)-dependent protein kinase C. This was followed by a slow Ca(2+)-independent and Rho-kinase/protein kinase C-dependent phosphorylation of CPI-17. In contrast, MYPT1 phosphorylation had only a slow component that increased from 0.29+/-0.09 at rest to the peak of 0.68+/-0.14 mol of Pi/mol at 1 minute, similar to the time course of contraction. Thus, there are 2 components of the Ca(2+) sensitization through inhibition of MLC phosphatase. Our results support the hypothesis that the initial rapid Ca(2+) rise induces a rapid inhibition of MLC phosphatase coincident with the Ca(2+)-induced MLC kinase activation to synergistically initiate a rapid MLC phosphorylation and contraction in arteries with abundant CPI-17 content.

Woodland-to-forest transition during prolonged drought in Minnesota after ca. AD 1300.

PubMed

Shuman, Bryan; Henderson, Anna K; Plank, Colin; Stefanova, Ivanka; Ziegler, Susy S

2009-10-01

Interactions among multiple causes of ecological perturbation, such as climate change and disturbance, can produce "ecological surprises." Here, we examine whether climate-fire-vegetation interactions can produce ecological changes that differ in direction from those expected from the effects of climate change alone. To do so, we focus on the "Big Woods" of central Minnesota, USA, which was shaped both by climate and fire. The deciduous Big Woods forest replaced regional woodlands and savannas after the severity of regional fire regimes declined at ca. AD 1300. A trend toward wet conditions has long been assumed to explain the forest expansion, but we show that water levels at two lakes within the region (Wolsfeld Lake and Bufflehead Pond) were low when open woodlands were transformed into the Big Woods. Water levels were high instead at ca. 2240-795 BC when regional fire regimes were most severe. Based on the correlation between water levels and fire-regime severity, we infer that prolonged or repeated droughts after ca. AD 1265 reduced the biomass and connectivity of fine fuels (grasses) within the woodlands. As a result, regional fire severity declined and allowed tree populations to expand. Tree-ring data from the region show a peak in the recruitment of key Big Woods tree species during the AD 1930s drought and suggest that low regional moisture balance need not have been a limiting factor for forest expansion. The regional history, thus, demonstrates the types of counterintuitive ecosystem changes that may arise as climate changes in the future.

The CaV2.3 R-Type Voltage-Gated Ca2+ Channel in Mouse Sleep Architecture

PubMed Central

Siwek, Magdalena Elisabeth; Müller, Ralf; Henseler, Christina; Broich, Karl; Papazoglou, Anna; Weiergräber, Marco

2014-01-01

Study Objectives: Voltage-gated Ca2+ channels (VGCCs) are key elements in mediating thalamocortical rhythmicity. Low-voltage activated (LVA) CaV 3 T-type Ca2+ channels have been related to thalamic rebound burst firing and to generation of non-rapid eye movement (NREM) sleep. High-voltage activated (HVA) CaV 1 L-type Ca2+ channels, on the opposite, favor the tonic mode of action associated with higher levels of vigilance. However, the role of the HVA Non-L-type CaV2.3 Ca2+ channels, which are predominantly expressed in the reticular thalamic nucleus (RTN), still remains unclear. Recently, CaV2.3−/− mice were reported to exhibit altered spike-wave discharge (SWD)/absence seizure susceptibility supported by the observation that CaV2.3 mediated Ca2+ influx into RTN neurons can trigger small-conductance Ca2+-activated K+-channel type 2 (SK2) currents capable of maintaining thalamic burst activity. Based on these studies we investigated the role of CaV2.3 R-type Ca2+ channels in rodent sleep. Methods: The role of CaV2.3 Ca2+ channels was analyzed in CaV2.3−/− mice and controls in both spontaneous and artificial urethane-induced sleep, using implantable video-EEG radiotelemetry. Data were analyzed for alterations in sleep architecture using sleep staging software and time-frequency analysis. Results: CaV2.3 deficient mice exhibited reduced wake duration and increased slow-wave sleep (SWS). Whereas mean sleep stage durations remained unchanged, the total number of SWS epochs was increased in CaV2.3−/− mice. Additional changes were observed for sleep stage transitions and EEG amplitudes. Furthermore, urethane-induced SWS mimicked spontaneous sleep results obtained from CaV2.3 deficient mice. Quantitative Real-time PCR did not reveal changes in thalamic CaV3 T-type Ca2+ channel expression. The detailed mechanisms of SWS increase in CaV2.3−/− mice remain to be determined. Conclusions: Low-voltage activated CaV2.3 R-type Ca2+ channels in the thalamocortical

Mg-Ca Alloys Produced by Reduction of CaO: Understanding of ECO-Mg Alloy Production

NASA Astrophysics Data System (ADS)

Jung, In-Ho; Lee, Jin Kyu; Kim, Shae K.

2017-04-01

There have been long debates about the environment conscious (ECO) Mg technology which utilizes CaO to produce Ca-containing Mg alloys. Two key process technologies of the ECO-Mg process are the chemical reduction of CaO by liquid Mg and the maintenance of melt cleanliness during the alloying of Ca. Thermodynamic calculations using FactSage software were performed to explain these two key issues. In addition, an experimental study was performed to compare the melt cleanliness of the Ca-containing Mg alloys produced by the conventional route with metallic Ca and the ECO-Mg route with CaO.

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

A NASA staff member shows attendees of the USA Science and Engineering Festival what happens to the human body in space without a space suit using a marshmallow bunny. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

A Phase IIb, Multicenter, Open-Label, Safety, and Efficacy Study of High-Dose, Propylene Glycol-Free Melphalan Hydrochloride for Injection (EVOMELA) for Myeloablative Conditioning in Multiple Myeloma Patients Undergoing Autologous Transplantation.

PubMed

Hari, Parameswaran; Aljitawi, Omar S; Arce-Lara, Carlos; Nath, Rajneesh; Callander, Natalie; Bhat, Gajanan; Allen, Lee F; Stockerl-Goldstein, Keith

2015-12-01

Autologous stem cell transplantation (ASCT) after high-dose melphalan conditioning is considered a standard of care procedure for patients with multiple myeloma (MM). Current formulations of melphalan (eg, Alkeran for Injection [melphalan hydrochloride]; GlaxoSmithKline, Research Triangle Park, NC, USA) have marginal solubility and limited chemical stability upon reconstitution. Alkeran requires the use of propylene glycol as a co-solvent, which itself has been reported to cause such complications as metabolic/renal dysfunction and arrhythmias. EVOMELA (propylene glycol-free melphalan HCl; Spectrum Pharmaceuticals, Inc., Irvine, CA, USA) is a new i.v. melphalan formulation that incorporates Captisol (Ligand Pharmaceuticals, Inc., La Jolla, CA, USA), a specially modified cyclodextrin that improves the solubility and stability of melphalan and eliminates the need for propylene glycol. This new formulation has been shown to be bioequivalent to Alkeran. EVOMELA (200 mg/m(2)) was administered as 2 doses of 100 mg/m(2) each in a phase IIb, open-label, multicenter study to confirm its safety and efficacy as a high-dose conditioning regimen for patients with MM undergoing ASCT. At 5 centers, 61 patients (26 women) with a median age of 62 years (range, 32-73) were enrolled. All patients achieved myeloablation with a median time of 5 days post-ASCT, and all successfully achieved neutrophil and platelet engraftment with median times of 12 days post-ASCT and 13 days post-ASCT, respectively; treatment-related mortality on day 100 was 0%. Overall response rate (according to independent, blinded review) was high (100%), with an overall complete response rate of 21% (13% stringent complete response; 8% complete response) and overall partial response rate of 79% (61% very good partial response; 18% partial response). The incidence of grade 3 mucositis and stomatitis was low (10% and 5%, respectively) with no grade 4 mucositis or stomatitis reported (graded according to National

I/Ca records of local redox history for contrasting depositional environments during Cenomanian-Turonian OAE2

NASA Astrophysics Data System (ADS)

Lu, Z.; Zhou, X.; Junium, C. K.; Sageman, B. B.; Jenkyns, H.

2012-12-01

Periods of catastrophic marine oxygen-depletion are known as Oceanic Anoxic Events (OAEs). The most severe OAE intervals in the geological record can be recognized by both positive and negative δ13C excursions, indicating major changes in the global carbon cycle. However, such geochemical expressions only mark the most significant periods of the OAE, characterized by massive carbon burial and/or injection of isotopically light carbon into the ocean-atmosphere system, effects that typically developed after the initial build-up of anoxic/euxinic conditions in many different basins worldwide. Iodide (I-) and iodate (IO3-) are the thermodynamically stable inorganic forms of iodine in seawater. Iodate is almost completely reduced to iodide in all investigated anoxic basins and OMZs. In a pilot study (Lu et al., 2010, Geology), I/Ca in synthetic calcite recorded iodate concentrations in the medium. This established the potential for I/Ca as a novel redox proxy and it was applied in two carbonate-rich sections recording the early Toarcian OAE (shallow-water carbonate platform site) and the Cenomanian-Turonian OAE 2 (pelagic chalk, Eastbourne, UK). Here we report preliminary I/Ca data from three more Cretaceous OAE 2 sections: Raia del Pedale (Italy), South Ferriby (UK), and Denver (USA) representing the Western Interior Seaway. Raia del Pedale is a shallow-water carbonate platform site. It has lower I/Ca values compared to those of the pelagic sites and the reducing condition lasted relatively longer. I/Ca data from the South Ferriby section have baseline values similar to those at Eastbourne (both are in chalk facies), while positive spikes on the profile may record upwelling episodes. The Western Interior Seaway site shows unique trends in redox conditions during the OAE, consistent with changes in TOC content. These preliminary data indicate that the development of reducing conditions was not synchronous on a global scale and that local environmental factors modified

Endothelial SK(Ca) and IK(Ca) channels regulate brain parenchymal arteriolar diameter and cortical cerebral blood flow.

PubMed

Hannah, Rachael M; Dunn, Kathryn M; Bonev, Adrian D; Nelson, Mark T

2011-05-01

Calcium-sensitive potassium (K(Ca)) channels have been shown to modulate the diameter of cerebral pial arteries; however, little is known regarding their roles in controlling cerebral parenchymal arterioles (PAs). We explored the function and cellular distribution of small-conductance (SK(Ca)) and intermediate-conductance (IK(Ca)) K(Ca) channels and large-conductance K(Ca) (BK(Ca)) channels in endothelial cells (ECs) and smooth muscle cells (SMCs) of PAs. Both SK(Ca) and IK(Ca) channels conducted the outward current in isolated PA ECs (current densities, ~20 pA/pF and ~28 pA/pF at +40 mV, respectively), but these currents were not detected in PA SMCs. In contrast, BK(Ca) currents were prominent in PA SMCs (~154 pA/pF), but were undetectable in PA ECs. Pressurized PAs constricted to inhibition of SK(Ca) (~16%) and IK(Ca) (~16%) channels, but were only modestly affected by inhibition of BK(Ca) channels (~5%). Blockade of SK(Ca) and IK(Ca) channels decreased resting cortical cerebral blood flow (CBF) by ~15%. NS309 (6,7-dichloro-1H-indole-2,3-dione3-oxime), a SK(Ca)/IK(Ca) channel opener, hyperpolarized PA SMCs by ~27 mV, maximally dilated pressurized PAs, and increased CBF by ~40%. In conclusion, these data show that SK(Ca) and IK(Ca) channels in ECs profoundly modulate PA tone and CBF, whereas BK(Ca) channels in SMCs only modestly influence PA diameter.

Structural, electronic, elastic, and thermodynamic properties of CaSi, Ca2Si, and CaSi2 phases from first-principles calculations

NASA Astrophysics Data System (ADS)

Li, X. D.; Li, K.; Wei, C. H.; Han, W. D.; Zhou, N. G.

2018-06-01

The structural, electronic, elastic, and thermodynamic properties of CaSi, Ca2Si, and CaSi2 are systematically investigated by using first-principles calculations method based on density functional theory (DFT). The calculated formation enthalpies and cohesive energies show that CaSi2 possesses the greatest structural stability and CaSi has the strongest alloying ability. The structural stability of the three phases is compared according to electronic structures. Further analysis on electronic structures indicates that the bonding of these phases exhibits the combinations of metallic, covalent, and ionic bonds. The elastic constants are calculated, and the bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and anisotropy factor of polycrystalline materials are deduced. Additionally, the thermodynamic properties were theoretically predicted and discussed.

Evidence-Based Redesign of the COMLEX-USA Series.

PubMed

Gimpel, John R; Horber, Dorothy; Sandella, Jeanne M; Knebl, Janice A; Thornburg, John E

2017-04-01

To ensure that the Comprehensive Osteopathic Medical Licensing Examination-USA (COMLEX-USA) reflects the evolving practice of osteopathic medicine, the National Board of Osteopathic Medical Examiners has developed new content and format specifications for an enhanced, competency-based examination program to be implemented with COMLEX-USA Level 3 in 2018. This article summarizes the evidence-based design processes that served as the foundation for blueprint development and the evidence supporting its validity. An overview is provided of the blueprint's 2 dimensions: Competency Domains and Clinical Presentations. The authors focus on the evidence that supports interpretation of test scores for the primary and intended purpose of COMLEX-USA, which is osteopathic physician licensure. Important secondary uses and the educational and catalytic effect of assessments are also described. This article concludes with the National Board of Osteopathic Medical Examiners' plans to ensure that the COMLEX-USA series remains current and meets the needs of its stakeholders-the patients who seek care from osteopathic physicians.

Ca2+ transients in cardiac myocytes measured with high and low affinity Ca2+ indicators.

PubMed Central

Berlin, J R; Konishi, M

1993-01-01

Intracellular calcium ion ([Ca2+]i) transients were measured in voltage-clamped rat cardiac myocytes with fura-2 or furaptra to quantitate rapid changes in [Ca2+]i. Patch electrode solutions contained the K+ salt of fura-2 (50 microM) or furaptra (300 microM). With identical experimental conditions, peak amplitude of stimulated [Ca2+]i transients in furaptra-loaded myocytes was 4- to 6-fold greater than that in fura-2-loaded cells. To determine the reason for this discrepancy, intracellular fura-2 Ca2+ buffering, kinetics of Ca2+ binding, and optical properties were examined. Decreasing cellular fura-2 concentration by lowering electrode fura-2 concentration 5-fold, decreased the difference between the amplitudes of [Ca2+]i transients in fura-2 and furaptra-loaded myocytes by twofold. Thus, fura-2 buffers [Ca2+]i under these conditions; however, Ca2+ buffering is not the only factor that explains the different amplitudes of the [Ca2+]i transients measured with these indicators. From the temporal comparison of the [Ca2+]i transients measured with fura-2 and furaptra, the apparent reverse rate constant for Ca2+ binding of fura-2 was at least 65s-1, much faster than previously reported in skeletal muscle fibers. These binding kinetics do not explain the difference in the size of the [Ca2+]i transients reported by fura-2 and furaptra. Parameters for fura-2 calibration, Rmin, Rmax, and beta, were obtained in salt solutions (in vitro) and in myocytes exposed to the Ca2+ ionophore, 4-Br A23187, in EGTA-buffered solutions (in situ). Calibration of fura-2 fluorescence signals with these in situ parameters yielded [Ca2+]i transients whose peak amplitude was 50-100% larger than those calculated with in vitro parameters. Thus, in vitro calibration of fura-2 fluorescence significantly underestimates the amplitude of the [Ca2+]i transient. These data suggest that the difference in amplitude of [Ca2+]i transients in fura-2 and furaptra-loaded myocytes is due, in part, to Ca2

The FEBS Journal in 2016: read, reflect and don't feed the wolves.

PubMed

Martin, Seamus J

2016-01-01

Seamus Martin holds the Smurfit Chair of Medical Genetics at the Smurfit Institute of Genetics, Trinity College Dublin, Ireland. He obtained his PhD with Tom Cotter at the National University of Ireland, followed by post-doctoral fellowships with Ivan Roitt at UCL, London, UK, and Doug Green at The La Jolla Institute for Allergy and Immunology, California, USA. He works on all aspects of cell death control and is especially interested in the links between apoptosis, necrosis and inflammation. He received the GlaxoSmithKline Award of The Biochemical Society for his work on unravelling the caspase activation cascade and was elected to the Royal Irish Academy in 2006 and EMBO in 2009. He has been the Editor-in-Chief of The FEBS Journal since 2014. © 2015 FEBS.

Quasi-Square Hole with Optimum Shape in an Infinite Plate Subjected to In-Plane Loading. Optimization of Inner and Outer Boundaries of Beams and Plates with Holes,

DTIC Science & Technology

1982-04-01

Division 045 Administracion Naval Ship Resarc; and Development 14114 (Technical Library) Structures Research Division Center Langley Research Center...Virginia 23607 university of California. San Diego Dr. J. L. Swedlow Department of Applied Mechanics Carnegie-Mellon University La Jolla, California...Batdorf Keman AviDyne Suite 220 University of California Division of Kaman La Jolla, California 92037 School of Engineering Sciences Corporation and

76 FR 35715 - Establishment of the SelectUSA Initiative

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-20

... Establishment of the SelectUSA Initiative By the authority vested in me as President by the Constitution and the... unnecessary obstacles to investment. Sec. 2. SelectUSA Initiative. (a) Establishment. There is established the SelectUSA Initiative (Initiative), a Government-wide initiative to attract and retain investment in the...

Calmodulin-dependent gating of Ca(v)1.2 calcium channels in the absence of Ca(v)beta subunits.

PubMed

Ravindran, Arippa; Lao, Qi Zong; Harry, Jo Beth; Abrahimi, Parwiz; Kobrinsky, Evgeny; Soldatov, Nikolai M

2008-06-10

It is generally accepted that to generate calcium currents in response to depolarization, Ca(v)1.2 calcium channels require association of the pore-forming alpha(1C) subunit with accessory Ca(v)beta and alpha(2)delta subunits. A single calmodulin (CaM) molecule is tethered to the C-terminal alpha(1C)-LA/IQ region and mediates Ca2+-dependent inactivation of the channel. Ca(v)beta subunits are stably associated with the alpha(1C)-interaction domain site of the cytoplasmic linker between internal repeats I and II and also interact dynamically, in a Ca2+-dependent manner, with the alpha(1C)-IQ region. Here, we describe a surprising discovery that coexpression of exogenous CaM (CaM(ex)) with alpha(1C)/alpha(2)delta in COS1 cells in the absence of Ca(v)beta subunits stimulates the plasma membrane targeting of alpha(1C), facilitates calcium channel gating, and supports Ca2+-dependent inactivation. Neither real-time PCR with primers complementary to monkey Ca(v)beta subunits nor coimmunoprecipitation analysis with exogenous alpha(1C) revealed an induction of endogenous Ca(v)beta subunits that could be linked to the effect of CaM(ex). Coexpression of a calcium-insensitive CaM mutant CaM(1234) also facilitated gating of Ca(v)beta-free Ca(v)1.2 channels but did not support Ca2+-dependent inactivation. Our results show there is a functional matchup between CaM(ex) and Ca(v)beta subunits that, in the absence of Ca(v)beta, renders Ca2+ channel gating facilitated by CaM molecules other than the one tethered to LA/IQ to support Ca2+-dependent inactivation. Thus, coexpression of CaM(ex) creates conditions when the channel gating, voltage- and Ca2+-dependent inactivation, and plasma-membrane targeting occur in the absence of Ca(v)beta. We suggest that CaM(ex) affects specific Ca(v)beta-free conformations of the channel that are not available to endogenous CaM.

Ca2+ spike initiation from sensitized inositol 1,4,5-trisphosphate-sensitive Ca2+ stores in megakaryocytes.

PubMed

Ikeda, M; Kurokawa, K; Maruyama, Y

1994-06-01

Ca(2+)-mediated Ca2+ spikes were analysed in fura-2-loaded megakaryocytes. Direct Ca2+ loading using whole-cell dialysis induced an all-or-none Ca2+ spike on top of a tonic increase in cellular Ca2+ concentration ([Ca2+]i) with a latency of 3-7 s. The latency decreased with increasingly higher concentrations of Ca2+ in the dialysing solution. Spike size and its initiation did not correlate with the tonic level of [Ca2+]i. Thapsigargin completely abolished the Ca(2+)-induced spike initiation, suggesting that Ca2+ spikes originate from thapsigargin-sensitive Ca2+ pools. An inhibitor of phosphatidylinositide-specific phospholipase C (PLC), 2-nitro-4-carboxyphenyl-N,N-diphenyl-carbamate prolonged the latency without changes of spike size in most cases (6/9 cells), but abolished the spike initiation in the other cells (3/9). The results suggest that an increase in [Ca2+]i charges up the inositol-1,4,5-trisphosphate-(InsP3)- and thapsigargin-sensitive Ca2+ pools which progressively sensitize to low or slightly elevated levels of InsP3 by the action of Ca(2+)-dependent PLC until a critical Ca2+ content is reached, and then the Ca2+ spike is triggered. Thus, the limiting step of Ca2+ spike triggering is the initial filling process and the level of InsP3 in megakaryocytes.

Aging and CaMKII alter intracellular Ca2+ transients and heart rhythm in Drosophila melanogaster.

PubMed

Santalla, Manuela; Valverde, Carlos A; Harnichar, Ezequiel; Lacunza, Ezequiel; Aguilar-Fuentes, Javier; Mattiazzi, Alicia; Ferrero, Paola

2014-01-01

Aging is associated to disrupted contractility and rhythmicity, among other cardiovascular alterations. Drosophila melanogaster shows a pattern of aging similar to human beings and recapitulates the arrhythmogenic conditions found in the human heart. Moreover, the kinase CaMKII has been characterized as an important regulator of heart function and an arrhythmogenic molecule that participate in Ca2+ handling. Using a genetically engineered expressed Ca2+ indicator, we report changes in cardiac Ca2+ handling at two different ages. Aging prolonged relaxation, reduced spontaneous heart rate (HR) and increased the occurrence of arrhythmias, ectopic beats and asystoles. Alignment between Drosophila melanogaster and human CaMKII showed a high degree of conservation and indicates that relevant phosphorylation sites in humans are also present in the fruit fly. Inhibition of CaMKII by KN-93 (CaMKII-specific inhibitor), reduced HR without significant changes in other parameters. By contrast, overexpression of CaMKII increased HR and reduced arrhythmias. Moreover, it increased fluorescence amplitude, maximal rate of rise of fluorescence and reduced time to peak fluorescence. These results suggest that CaMKII in Drosophila melanogaster acts directly on heart function and that increasing CaMKII expression levels could be beneficial to improve contractility.

Voltage-dependent Ca2+ release from the SR of feline ventricular myocytes is explained by Ca2+-induced Ca2+ release.

PubMed

Piacentino, V; Dipla, K; Gaughan, J P; Houser, S R

2000-03-15

1. Direct voltage-gated (voltage-dependent Ca2+ release, VDCR) and Ca2+ influx-gated (Ca2+-induced Ca2+ release, CICR) sarcoplasmic reticulum (SR) Ca2+ release were studied in feline ventricular myocytes. The voltage-contraction relationship predicted by the VDCR hypothesis is sigmoidal with large contractions at potentials near the Ca2+ equilibrium potential (ECa). The relationship predicted by the CICR hypothesis is bell-shaped with no contraction at ECa. 2. The voltage dependence of contraction was measured in ventricular myocytes at physiological temperature (37 C), resting membrane potential and physiological [K+]. Experiments were performed with cyclic adenosine 3',5'-monophosphate (cAMP) in the pipette or in the presence of the beta-adrenergic agonist isoproterenol (isoprenaline; ISO). 3. The voltage-contraction relationship was bell-shaped in Na+-free solutions (to eliminate the Na+ current and Na+-Ca2+ exchange, NCX) but the relationship was broader than the L-type Ca2+ current (ICa,L)-voltage relationship. 4. Contractions induced with voltage steps from normal resting potentials to -40 mV are thought to represent VDCR rather than CICR. We found that cAMP and ISO shifted the voltage dependence of ICa,L activation to more negative potentials so that ICa,L was always present with steps to -40 mV. ICa,L at -40 mV inactivated when the holding potential was decreased (VŁ = -57.8 +/- 0.49 mV). 5. ISO increased inward current, SR Ca2+ load and contraction in physiological [Na+] and a broad bell-shaped voltage-contraction relationship was observed. Inhibition of reverse-mode NCX, decreasing ICa,L and decreasing SR Ca2+ loading all decreased contractions at strongly positive potentials near ECa. 6. The voltage-contraction relationship in 200 microM cadmium (Cd2+) was bell-shaped, supporting a role of ICa,L rather than VDCR. 7. All results could be accounted for by the CICR hypothesis, and many results exclude the VDCR hypothesis.

Voltage-dependent Ca2+ release from the SR of feline ventricular myocytes is explained by Ca2+-induced Ca2+ release

PubMed Central

Piacentino, Valentino; Dipla, Konstantina; Gaughan, John P; Houser, Steven R

2000-01-01

Direct voltage-gated (voltage-dependent Ca2+ release, VDCR) and Ca2+ influx-gated (Ca2+-induced Ca2+ release, CICR) sarcoplasmic reticulum (SR) Ca2+ release were studied in feline ventricular myocytes. The voltage-contraction relationship predicted by the VDCR hypothesis is sigmoidal with large contractions at potentials near the Ca2+ equilibrium potential (ECa). The relationship predicted by the CICR hypothesis is bell-shaped with no contraction at ECa. The voltage dependence of contraction was measured in ventricular myocytes at physiological temperature (37 °C), resting membrane potential and physiological [K+]. Experiments were performed with cyclic adenosine 3′,5′-monophosphate (cAMP) in the pipette or in the presence of the β-adrenergic agonist isoproterenol (isoprenaline; ISO). The voltage-contraction relationship was bell-shaped in Na+-free solutions (to eliminate the Na+ current and Na+-Ca2+ exchange, NCX) but the relationship was broader than the L-type Ca2+ current (ICa,L)-voltage relationship. Contractions induced with voltage steps from normal resting potentials to -40 mV are thought to represent VDCR rather than CICR. We found that cAMP and ISO shifted the voltage dependence of ICa,L activation to more negative potentials so that ICa,L was always present with steps to -40 mV. ICa,L at -40 mV inactivated when the holding potential was decreased (V½ =−57·8 ± 0·49 mV). ISO increased inward current, SR Ca2+ load and contraction in physiological [Na+] and a broad bell-shaped voltage-contraction relationship was observed. Inhibition of reverse-mode NCX, decreasing ICa,L and decreasing SR Ca2+ loading all decreased contractions at strongly positive potentials near ECa. The voltage-contraction relationship in 200 μM cadmium (Cd2+) was bell-shaped, supporting a role of ICa,L rather than VDCR. All results could be accounted for by the CICR hypothesis, and many results exclude the VDCR hypothesis. PMID:10718736

Incremental Aerodynamic Coefficient Database for the USA2

NASA Technical Reports Server (NTRS)

Richardson, Annie Catherine

2016-01-01

In March through May of 2016, a wind tunnel test was conducted by the Aerosciences Branch (EV33) to visually study the unsteady aerodynamic behavior over multiple transition geometries for the Universal Stage Adapter 2 (USA2) in the MSFC Aerodynamic Research Facility's Trisonic Wind Tunnel (TWT). The purpose of the test was to make a qualitative comparison of the transonic flow field in order to provide a recommended minimum transition radius for manufacturing. Additionally, 6 Degree of Freedom force and moment data for each configuration tested was acquired in order to determine the geometric effects on the longitudinal aerodynamic coefficients (Normal Force, Axial Force, and Pitching Moment). In order to make a quantitative comparison of the aerodynamic effects of the USA2 transition geometry, the aerodynamic coefficient data collected during the test was parsed and incorporated into a database for each USA2 configuration tested. An incremental aerodynamic coefficient database was then developed using the generated databases for each USA2 geometry as a function of Mach number and angle of attack. The final USA2 coefficient increments will be applied to the aerodynamic coefficients of the baseline geometry to adjust the Space Launch System (SLS) integrated launch vehicle force and moment database based on the transition geometry of the USA2.

Calculated and measured [Ca(2+)] in buffers used to calibrate Ca(2+) macroelectrodes.

PubMed

McGuigan, John A S; Stumpff, Friederike

2013-05-01

The ionized concentration of calcium in physiological buffers ([Ca(2+)]) is normally calculated using either tabulated constants or software programs. To investigate the accuracy of such calculations, the [Ca(2+)] in EGTA [ethylene glycol-bis(β-aminoethylether)-N,N,N|,N|-tetraacetic acid], BAPTA [1,2-bis(o-aminophenoxy) ethane-N,N,N|,N|-tetraacetic acid], HEDTA [N-(2-hydroxyethyl)-ethylenediamine-N,N|,N|-triacetic acid], and NTA [N,N-bis(carboxymethyl)glycine] buffers was estimated using the ligand optimization method, and these measured values were compared with calculated values. All measurements overlapped in the pCa range of 3.51 (NTA) to 8.12 (EGTA). In all four buffer solutions, there was no correlation between measured and calculated values; the calculated values differed among themselves by factors varying from 1.3 (NTA) to 6.9 (EGTA). Independent measurements of EGTA purity and the apparent dissociation constants for HEDTA and NTA were not significantly different from the values estimated by the ligand optimization method, further substantiating the method. Using two calibration solutions of pCa 2.0 and 3.01 and seven buffers in the pCa range of 4.0-7.5, calibration of a Ca(2+) electrode over the pCa range of 2.0-7.5 became a routine procedure. It is proposed that such Ca(2+) calibration/buffer solutions be internationally defined and made commercially available to allow the precise measurement of [Ca(2+)] in biology. Copyright © 2013 Elsevier Inc. All rights reserved.

CaMKII and CaMKIV mediate distinct prosurvival signaling pathways in response to depolarization in neurons

PubMed Central

Bok, Jinwoong; Wang, Qiong; Huang, Jie; Green, Steven H.

2007-01-01

By fusing the CaMKII inhibitory peptide AIP to GFP, we constructed a specific and effective CaMKII inhibitor, GFP-AIP. Expression of GFP-AIP and/or dominant-inhibitory CaMKIV in cultured neonatal rat spiral ganglion neurons (SGNs) shows that CaMKII and CaMKIV act additively and in parallel, to mediate the prosurvival effect of depolarization. Depolarization or expression of constitutively-active CaMKII functionally inactivates Bad, indicating that this is one means by which CaMKII promotes neuronal survival. CaMKIV, but not CaMKII, requires CREB to promote SGN survival, consistent with the exclusively nuclear localization of CaMKIV and indicating that the principal prosurvival function of CaMKIV is activation of CREB. Consistent with this, a constitutively-active CREB construct that provides a high level of CREB activity promotes SGN survival, although low levels of CREB activity did not do so. Also, in apoptotic SGNs, activation of CREB by depolarization is disabled, presumably as part of a cellular commitment to apoptosis. PMID:17651987

Late INa increases diastolic SR-Ca2+-leak in atrial myocardium by activating PKA and CaMKII

PubMed Central

Fischer, Thomas H.; Herting, Jonas; Mason, Fleur E.; Hartmann, Nico; Watanabe, Saera; Nikolaev, Viacheslav O.; Sprenger, Julia U.; Fan, Peidong; Yao, Lina; Popov, Aron-Frederik; Danner, Bernhard C.; Schöndube, Friedrich; Belardinelli, Luiz; Hasenfuss, Gerd; Maier, Lars S.; Sossalla, Samuel

2015-01-01

Aims Enhanced cardiac late Na current (late INa) and increased sarcoplasmic reticulum (SR)-Ca2+-leak are both highly arrhythmogenic. This study seeks to identify signalling pathways interconnecting late INa and SR-Ca2+-leak in atrial cardiomyocytes (CMs). Methods and results In murine atrial CMs, SR-Ca2+-leak was increased by the late INa enhancer Anemonia sulcata toxin II (ATX-II). An inhibition of Ca2+/calmodulin-dependent protein kinase II (Autocamide-2-related inhibitory peptide), protein kinase A (H89), or late INa (Ranolazine or Tetrodotoxin) all prevented ATX-II-dependent SR-Ca2+-leak. The SR-Ca2+-leak induction by ATX-II was not detected when either the Na+/Ca2+ exchanger was inhibited (KBR) or in CaMKIIδc-knockout mice. FRET measurements revealed increased cAMP levels upon ATX-II stimulation, which could be prevented by inhibition of adenylyl cyclases (ACs) 5 and 6 (NKY 80) but not by inhibition of phosphodiesterases (IBMX), suggesting PKA activation via an AC-dependent increase of cAMP levels. Western blots showed late INa-dependent hyperphosphorylation of CaMKII as well as PKA target sites at ryanodine receptor type-2 (-S2814 and -S2808) and phospholamban (-Thr17, -S16). Enhancement of late INa did not alter Ca2+-transient amplitude or SR-Ca2+-load. However, upon late INa activation and simultaneous CaMKII inhibition, Ca2+-transient amplitude and SR-Ca2+-load were increased, whereas PKA inhibition reduced Ca2+-transient amplitude and load and additionally slowed Ca2+ elimination. In atrial CMs from patients with atrial fibrillation, inhibition of late INa, CaMKII, or PKA reduced the SR-Ca2+-leak. Conclusion Late INa exerts distinct effects on Ca2+ homeostasis in atrial myocardium through activation of CaMKII and PKA. Inhibition of late INa represents a potential approach to attenuate CaMKII activation and decreases SR-Ca2+-leak in atrial rhythm disorders. The interconnection with the cAMP/PKA system further increases the antiarrhythmic potential of late

Regional variation in the chemical composition of winter snow pack and terricolous lichens in relation to sources of acid emissions in the Usa river basin, northeast European Russia.

PubMed

Walker, T R; Crittenden, P D; Young, S D

2003-01-01

The chemical composition of snow and terricolous lichens was determined along transects through the Subarctic towns of Vorkuta (130 km west-east), Inta (240 km south-north) and Usinsk (140 km, southwest-northeast) in the Usa river basin, northeast European Russia. Evidence of pollution gradients was found on two spatial scales. First, on the Inta transect, northward decreases in concentrations of N in the lichen Cladonia stellaris (from 0.57 mmol N g(-1) at 90 km south to 0.43 mmol N g(-1) at 130 km north of Inta) and winter deposition of non-sea salt sulphate (from 29.3 to 12.8 mol ha(-1) at 90 km south and 110 km north of Inta, respectively) were attributed to long range transport of N and S from lower latitudes. Second, increased ionic content (SO42-, Ca2+, K+) and pH of snow, and modified N concentration and the concentration ratios K+:Mg2+ and K+: (Mg2++Ca2+) in lichens (Cladonia arbuscula and Flavocetraria cucullata) within ca. 25-40 km of Vorkuta and Inta were largely attributed to local deposition of alkaline coal ash. Total sulphate concentrations in snow varied from ca. 5 micromol l(-1) at remote sites to ca. 19 micromol l(-1) near Vorkuta. Nitrate concentration in snow (typically ca. 9 micromol l(-1)) did not vary with proximity to perceived pollution sources.

CaV 3.1 and CaV 3.3 account for T-type Ca2+ current in GH3 cells.

PubMed

Mudado, M A; Rodrigues, A L; Prado, V F; Beirão, P S L; Cruz, J S

2004-06-01

T-type Ca2+ channels are important for cell signaling by a variety of cells. We report here the electrophysiological and molecular characteristics of the whole-cell Ca2+ current in GH3 clonal pituitary cells. The current inactivation at 0 mV was described by a single exponential function with a time constant of 18.32 +/- 1.87 ms (N = 16). The I-V relationship measured with Ca2+ as a charge carrier was shifted to the left when we applied a conditioning pre-pulse of up to -120 mV, indicating that a low voltage-activated current may be present in GH3 cells. Transient currents were first activated at -50 mV and peaked around -20 mV. The half-maximal voltage activation and the slope factors for the two conditions are -35.02 +/- 2.4 and 6.7 +/- 0.3 mV (pre-pulse of -120 mV, N = 15), and -27.0 +/- 0.97 and 7.5 +/- 0.7 mV (pre-pulse of -40 mV, N = 9). The 8-mV shift in the activation mid-point was statistically significant (P < 0.05). The tail currents decayed bi-exponentially suggesting two different T-type Ca2+ channel populations. RT-PCR revealed the presence of alpha1G (CaV3.1) and alpha1I (CaV3.3) T-type Ca2+ channel mRNA transcripts.

Subcellular distributions of rat CaM kinase phosphatase N and other members of the CaM kinase regulatory system.

PubMed

Kitani, Takako; Okuno, Sachiko; Takeuchi, Masayuki; Fujisawa, Hitoshi

2003-07-01

Ca2+/Calmodulin-dependent protein kinase (CaM kinase) regulatory system is composed of multifunctional CaM kinases such as CaM kinases IV and I, upstream CaM kinases such as CaM kinase kinases alpha and beta, which activate multifunctional CaM kinases, and CaM kinase phosphatases such as CaM kinase phosphatase and CaM kinase phosphatase N, which deactivate the activated multifunctional CaM kinases. To understand the combinations of CaM kinases I and IV, CaM kinase kinases alpha and beta, and CaM kinase phosphatases, the locations of the enzymes in the cell were examined by immunocytochemical studies of cultured cells. The results indicate that CaM kinase I, CaM kinase kinase beta, and CaM kinase phosphatase occur in the cytoplasm and that CaM kinase IV, CaM kinase kinase alpha (and CaM kinase kinase beta in some cell types and tissues), and CaM kinase phosphatase N occur inside the cellular nucleus, suggesting that there are at least two different sets of CaM kinase regulatory systems, one consisting of CaM kinase I, CaM kinase kinase beta, and CaM kinase phosphatase in the cytoplasm and the other consisting of CaM kinase IV, CaM kinase kinase alpha (and CaM kinase kinase beta in some cell types and tissues), and CaM kinase phosphatase N in the nucleus.

Electrogenic Na+/Ca2+ Exchange

PubMed Central

Danaceau, Jonathan P.; Lucero, Mary T.

2000-01-01

Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca2+ concentrations ([Ca2+]i). To directly asses the effects of increasing [Ca2+]i in perforated-patched squid ORNs, we applied 10 mM caffeine to release Ca2+ from internal stores. We observed an inward current response to caffeine. Monovalent cation replacement of Na+ from the external bath solution completely and selectively inhibited the caffeine-induced response, and ruled out the possibility of a Ca2+-dependent nonselective cation current. The strict dependence on internal Ca2+ and external Na+ indicated that the inward current was due to an electrogenic Na+/Ca2+ exchanger. Block of the caffeine-induced current by an inhibitor of Na+/Ca2+ exchange (50–100 μM 2′,4′-dichlorobenzamil) and reversibility of the exchanger current, further confirmed its presence. We tested whether Na+/Ca2+ exchange contributed to odor responses by applying the aquatic odor l-glutamate in the presence and absence of 2′,4′-dichlorobenzamil. We found that electrogenic Na+/Ca2+ exchange was responsible for ∼26% of the total current associated with glutamate-induced odor responses. Although Na+/Ca2+ exchangers are known to be present in ORNs from numerous species, this is the first work to demonstrate amplifying contributions of the exchanger current to odor transduction. PMID:10828249

Genetic and Physiological Control of Protective Antigen Synthesis by Bacillus anthracis

DTIC Science & Technology

1985-07-01

ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, T’ASK Department of Microbiology AE OKUI UBR University of Massachusetts 61102A.3M161102BS12.AB...in a 600C water bath for 30 min. Five-tenths ml of Pronase (Calbiochem-Behring Corp., La Jolla, CA) solution (2 mg per ml in 2 M Tris at pH 07.0) was...0 0 0 L 0% m% ON a% 0% ON 0% 0\\ ON 𔃺 0 𔃺 %0 %0 𔃺 4 𔃺 𔃺 𔃺 ’.0 𔃺 %0 𔃺 %0 𔃺 𔃺 %D 𔃺 ’ 0 𔃺 %0 0 L-A Ln LA % Ln Ul LAN Ul UA ul -20- >1 L C~ L

Aging and CaMKII Alter Intracellular Ca2+ Transients and Heart Rhythm in Drosophila melanogaster

PubMed Central

Santalla, Manuela; Valverde, Carlos A.; Harnichar, Ezequiel; Lacunza, Ezequiel; Aguilar-Fuentes, Javier; Mattiazzi, Alicia; Ferrero, Paola

2014-01-01

Aging is associated to disrupted contractility and rhythmicity, among other cardiovascular alterations. Drosophila melanogaster shows a pattern of aging similar to human beings and recapitulates the arrhythmogenic conditions found in the human heart. Moreover, the kinase CaMKII has been characterized as an important regulator of heart function and an arrhythmogenic molecule that participate in Ca2+ handling. Using a genetically engineered expressed Ca2+ indicator, we report changes in cardiac Ca2+ handling at two different ages. Aging prolonged relaxation, reduced spontaneous heart rate (HR) and increased the occurrence of arrhythmias, ectopic beats and asystoles. Alignment between Drosophila melanogaster and human CaMKII showed a high degree of conservation and indicates that relevant phosphorylation sites in humans are also present in the fruit fly. Inhibition of CaMKII by KN-93 (CaMKII-specific inhibitor), reduced HR without significant changes in other parameters. By contrast, overexpression of CaMKII increased HR and reduced arrhythmias. Moreover, it increased fluorescence amplitude, maximal rate of rise of fluorescence and reduced time to peak fluorescence. These results suggest that CaMKII in Drosophila melanogaster acts directly on heart function and that increasing CaMKII expression levels could be beneficial to improve contractility. PMID:25003749

Is Soil Development Controlling Ecohydrologic Response to Climate Change in the Southern Cascade and Sierra Nevada Watersheds, CA, USA?

NASA Astrophysics Data System (ADS)

Devine, S.; O'Geen, A. T.; Dahlke, H. E.

2016-12-01

Understanding climate change impacts on hydrology is especially relevant to areas already dealing with water scarcity, common in Mediterranean regions such as California (CA). For instance, warming is expected to drive up evapotranspiration (ET) fluxes from vegetation, which could impact runoff (Q) and water supply by up to 30% from CA's Sierra Nevadas by 2100. In this study, we hypothesize that the 1-2 oC increase during the 20th and early 21st centuries should have resulted in a trend of decreasing Q for a given amount of precipitation (P) due to increasing ET through time. We also hypothesize that any observed differences in watershed ET response to warming could be explained by soil controls, since Mediterranean biomes require soil moisture storage to endure dry summers. We analyzed unimpaired runoff from 10 major CA watersheds relative to P over a 110 year record and found trends of increasing P minus Q in the northern watersheds, supporting the hypothesis of mountain Q vulnerability to warming but not in the central and southern watersheds. This may be partly due to the faster rates of summertime warming we observed in the northern watersheds when potential ET is highest. Analysis of several soil investigations in the study area on bioclimosequences suggests that these inter-watershed differences in P minus Q may also be due to soils. Soils formed from volcanic rocks, which are more prevalent in the northern watersheds, tend to have higher clay contents and water holding capacity. Moreover, the higher elevation central and southern watersheds were more widely glaciated throughout the Pleistocene, resulting in a wider extent of scoured landscapes and soils shallow to hard bedrock. Thus, the northern watershed ET flux could have previously been temperature constrained with untapped soil moisture storage. Going forward, an analysis is planned to quantify the extent of various soil-vegetation-climate zones. For each zone, we will build simple water balance models

Edward C. Little Water Recycling Plant, El Segundo, CA: CA0063401

EPA Pesticide Factsheets

Joint EPA and Los Angeles Regional Water Quality Control Board NPDES Permit and Waiver from Secondary Treatment for the West Basin Municipal Water District Edward C. Little Water Recycling Plant, El Segundo, CA: CA0063401

Decoding Ca2+ signals in plants

NASA Technical Reports Server (NTRS)

Sathyanarayanan, P. V.; Poovaiah, B. W.

2004-01-01

Different input signals create their own characteristic Ca2+ fingerprints. These fingerprints are distinguished by frequency, amplitude, duration, and number of Ca2+ oscillations. Ca(2+)-binding proteins and protein kinases decode these complex Ca2+ fingerprints through conformational coupling and covalent modifications of proteins. This decoding of signals can lead to a physiological response with or without changes in gene expression. In plants, Ca(2+)-dependent protein kinases and Ca2+/calmodulin-dependent protein kinases are involved in decoding Ca2+ signals into phosphorylation signals. This review summarizes the elements of conformational coupling and molecular mechanisms of regulation of the two groups of protein kinases by Ca2+ and Ca2+/calmodulin in plants.

Backbone and side-chain resonance assignments of (Ca2+)4-calmodulin bound to beta calcineurin A CaMBD peptide.

PubMed

Fowler, C Andrew; Núñez Hernandez, Maria F; O'Donnell, Susan E; Yu, Liping; Shea, Madeline A

2017-10-01

Calcineurin (CaN) is a heterodimeric and highly conserved serine/threonine phosphatase (PP2B) that plays a critical role in coupling calcium signals to physiological processes including embryonic cardiac development, NF-AT-regulated gene expression in immune responses, and apoptosis. The catalytic subunit (CaN A ) has three isoforms (α, β, and γ,) in humans and seven isoforms in Paramecium. In all eukaryotes, the EF-hand protein calmodulin (CaM) regulates CaN activity in a calcium-dependent manner. The N- and C-domains of CaM (CaM N and CaM C ) recognize a CaM-binding domain (CaMBD) within an intrinsically disordered region of CaN A that precedes the auto-inhibitory domain (AID) of CaN A . Here we present nearly complete 1 H, 13 C, and 15 N resonance assignments of (Ca 2+ ) 4 -CaM bound to a peptide containing the CaMBD sequence in the beta isoform of CaN A (βCaN A -CaMBDp). Its secondary structure elements predicted from the assigned chemical shifts were in good agreement with those observed in the high-resolution structures of (Ca 2+ ) 4 -CaM bound to CaMBDs of multiple enzymes. Based on the reported literature, the CaMBD of the α isoform of CaN A can bind to CaM in two opposing orientations which may influence the regulatory function of CaM. Because a high resolution structure of (Ca 2+ ) 4 -CaM bound to βCaN A -CaMBDp has not been reported, our studies serve as a starting point for determining the solution structure of this complex. This will demonstrate the preferred orientation of (Ca 2+ ) 4 -CaM on the CaMBD as well as the orientations of CaM N and CaM C relative to each other and to the AID of βCaN A .

Influence of ER leak on resting cytoplasmic Ca2+ and receptor-mediated Ca2+ signalling in human macrophage.

PubMed

Layhadi, Janice A; Fountain, Samuel J

2017-06-03

Mechanisms controlling endoplasmic reticulum (ER) Ca 2+ homeostasis are important regulators of resting cytoplasmic Ca 2+ concentration ([Ca 2+ ] cyto ) and receptor-mediated Ca 2+ signalling. Here we investigate channels responsible for ER Ca 2+ leak in THP-1 macrophage and human primary macrophage. In the absence of extracellular Ca 2+ we employ ionomycin action at the plasma membrane to stimulate ER Ca 2+ leak. Under these conditions ionomycin elevates [Ca 2+ ] cyto revealing a Ca 2+ leak response which is abolished by thapsigargin. IP 3 receptors (Xestospongin C, 2-APB), ryanodine receptors (dantrolene), and translocon (anisomycin) inhibition facilitated ER Ca 2+ leak in model macrophage, with translocon inhibition also reducing resting [Ca 2+ ] cyto . In primary macrophage, translocon inhibition blocks Ca 2+ leak but does not influence resting [Ca 2+ ] cyto . We identify a role for translocon-mediated ER Ca 2+ leak in receptor-mediated Ca 2+ signalling in both model and primary human macrophage, whereby the Ca 2+ response to ADP (P2Y receptor agonist) is augmented following anisomycin treatment. In conclusion, we demonstrate a role of ER Ca 2+ leak via the translocon in controlling resting cytoplasmic Ca 2+ in model macrophage and receptor-mediated Ca 2+ signalling in model macrophage and primary macrophage. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of serum CA27.29, CA15-3 and CEA in patients with breast cancer.

PubMed

Hou, M F; Chen, Y L; Tseng, T F; Lin, C M; Chen, M S; Huang, C J; Huang, Y S; Hsieh, J S; Huang, T J; Jong, S B; Huang, Y F

1999-09-01

The Truquant BR radioimmunoassay (RIA) using monoclonal antibody BR 27.29 to recognize a peptide sequence on the MUC-1 gene product for quantification of the CA 27.29 antigen in serum was used in this report to evaluate in 145 patients with breast cancer and compared the other conventional serum markers such as CA15-3 and CEA. The upper limit of normal (25 u/ml) was determined from CA27.29 values 12.4 +/- 4.1 u/ml (mean +/- 3 S.D.) for 112 female subjects apparently free of disease. The CA15-3 levels above 25 u/ml and CEA levels above 5 ng/ml were considered positive values. Thirty-seven cases of 145 patients studied had elevated CA 27.29 levels (sensitivity: 25.5%), 35 of 145 had positive CA15-3 levels (sensitivity 24.1%) and 27 of 145 patients had positive CEA levels (sensitivity: 18.6%) (p < 0.05). One hundred and ten cases of the breast cancer patients (75.8%) did not have metastatic disease. In this group CA 27.29 sensitivity was 6.4%, while CA15-3 sensitivity was 5.5% and CEA sensitivity was 4.5% (p > 0.05). Mean values were 10.2 +/- 9.2 u/ml for CA 27.29, 14.1 +/- 5.6 u/ml for CA 15-3 and 1.7 +/- 1.5 ng/ml for CEA. Thirty-five patients (24.2%) had metastatic disease. In this group CA 27.29 sensitivity was 85.7%, CA15-3 sensitivity was 82.8% and CEA sensitivity was 62.8% (p < 0.05). Mean values for CA27.29 was 152.6 +/- 131.6 u/ml, CA15-3 was 123.1 +/- 107.6 u/ml and 21.8 +/- 36.9 ng/ml of CEA. With regard to the correlation of three tumor markers with clinical stages, patients had significantly higher levels of CA27.29 than CEA, but they were similar to CA 15-3 in metastatic breast cancer. These results suggest CA27.29 to be more sensitive and specific than CEA, but that it is similar to CA15-3 for metastatic breast cancer detection and monitoring.

Flecainide inhibits arrhythmogenic Ca2+ waves by open state block of ryanodine receptor Ca2+ release channels and reduction of Ca2+ spark mass

PubMed Central

Hilliard, Fredrick A.; Steele, Derek S.; Laver, Derek; Yang, Zhaokang; Le Marchand, Sylvain J.; Chopra, Nagesh; Piston, David W.; Huke, Sabine; Knollmann, Björn C.

2009-01-01

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is linked to mutations in the cardiac ryanodine receptor (RyR2) or calsequestrin. We recently found that the drug flecainide inhibits RyR2 channels and prevents CPVT in mice and humans. Here we compared the effects of flecainide and tetracaine, a known RyR2 inhibitor ineffective in CPVT myocytes, on arrhythmogenic Ca2+ waves and elementary sarcoplasmic reticulum (SR) Ca2+ release events, Ca2+ sparks. In ventricular myocytes isolated from a CPVT mouse model, flecainide significantly reduced spark amplitude and spark width, resulting in a 40% reduction in spark mass. Surprisingly, flecainide significantly increased spark frequency. As a result, flecainide had no significant effect on spark-mediated SR Ca2+ leak or SR Ca2+ content. In contrast, tetracaine decreased spark frequency and spark-mediated SR Ca2+ leak, resulting in a significantly increased SR Ca2+ content. Measurements in permeabilized rat ventricular myocytes confirmed the different effects of flecainide and tetracaine on spark frequency and Ca2+ waves. In lipid bilayers, flecainide inhibited RyR2 channels by open state block, whereas tetracaine primarily prolonged RyR2 closed times. The differential effects of flecainide and tetracaine on sparks and RyR2 gating can explain why flecainide, unlike tetracaine, does not change the balance of SR Ca2+ fluxes. We suggest that the smaller spark mass contributes to flecainide's antiarrhythmic action by reducing the probability of saltatory wave propagation between adjacent Ca2+ release units. Our results indicate that inhibition of the RyR2 open state provides a new therapeutic strategy to prevent diastolic Ca2+ waves resulting in triggered arrhythmias, such as CPVT. PMID:19835880

Integration of GCAM-USA into GLIMPSE: Update and ...

EPA Pesticide Factsheets

The purpose of this presentation is to (i) discuss changes made to the GCAM-USA model to more fully support long-term, coordinated environmental-climate-energy planning within the U.S., and (ii) demonstrate the graphical user interface that has been constructed to construct modeling scenarios, execute GCAM-USA, and visualize and compare model outputs. GLIMPSE is intended to provide insights into linkages and synergies among the goals of air quality management, climate change mitigation, and long-range energy planning. We have expanded GLIMPSE to also incorporate the open-source Global Change Assessment Model-USA (GCAM-USA), which has state-level representation of the U.S. energy system. With GCAM-USA, GLIMPSE can consider more aspects of the economy, linkages to the water and climate systems, and interactions with other regions of the world. A user-friendly graphical interface allows the system to be applied by analysts to explore a range of policies, such emission taxes or caps, efficiency standards, and renewable portfolio standards. We expect GLIMPSE to be used within research and planning activities, both within the EPA and beyond.

Photosynthetic and Growth Response of Sugar Maple (Acer saccharum Marsh.) Mature Trees and Seedlings to Calcium, Magnesium, and Nitrogen Additions in the Catskill Mountains, NY, USA.

PubMed

Momen, Bahram; Behling, Shawna J; Lawrence, Greg B; Sullivan, Joseph H

2015-01-01

Decline of sugar maple in North American forests has been attributed to changes in soil calcium (Ca) and nitrogen (N) by acidic precipitation. Although N is an essential and usually a limiting factor in forests, atmospheric N deposition may cause N-saturation leading to loss of soil Ca. Such changes can affect carbon gain and growth of sugar maple trees and seedlings. We applied a 22 factorial arrangement of N and dolomitic limestone containing Ca and Magnesium (Mg) to 12 forest plots in the Catskill Mountain region of NY, USA. To quantify the short-term effects, we measured photosynthetic-light responses of sugar maple mature trees and seedlings two or three times during two summers. We estimated maximum net photosynthesis (An-max) and its related light intensity (PAR at An-max), apparent quantum efficiency (Aqe), and light compensation point (LCP). To quantify the long-term effects, we measured basal area of living mature trees before and 4 and 8 years after treatment applications. Soil and foliar chemistry variables were also measured. Dolomitic limestone increased Ca, Mg, and pH in the soil Oe horizon. Mg was increased in the B horizon when comparing the plots receiving N with those receiving CaMg. In mature trees, foliar Ca and Mg concentrations were higher in the CaMg and N+CaMg plots than in the reference or N plots; foliar Ca concentration was higher in the N+CaMg plots compared with the CaMg plots, foliar Mg was higher in the CaMg plots than the N+CaMg plots; An-max was maximized due to N+CaMg treatment; Aqe decreased by N addition; and PAR at An-max increased by N or CaMg treatments alone, but the increase was maximized by their combination. No treatment effect was detected on basal areas of living mature trees four or eight years after treatment applications. In seedlings, An-max was increased by N+CaMg addition. The reference plots had an open herbaceous layer, but the plots receiving N had a dense monoculture of common woodfern in the forest floor

Photosynthetic and Growth Response of Sugar Maple (Acer saccharum Marsh.) Mature Trees and Seedlings to Calcium, Magnesium, and Nitrogen Additions in the Catskill Mountains, NY, USA

PubMed Central

Momen, Bahram; Behling, Shawna J.; Lawrence, Greg B.; Sullivan, Joseph H.

2015-01-01

Decline of sugar maple in North American forests has been attributed to changes in soil calcium (Ca) and nitrogen (N) by acidic precipitation. Although N is an essential and usually a limiting factor in forests, atmospheric N deposition may cause N-saturation leading to loss of soil Ca. Such changes can affect carbon gain and growth of sugar maple trees and seedlings. We applied a 22 factorial arrangement of N and dolomitic limestone containing Ca and Magnesium (Mg) to 12 forest plots in the Catskill Mountain region of NY, USA. To quantify the short-term effects, we measured photosynthetic-light responses of sugar maple mature trees and seedlings two or three times during two summers. We estimated maximum net photosynthesis (An-max) and its related light intensity (PAR at An-max), apparent quantum efficiency (A qe), and light compensation point (LCP). To quantify the long-term effects, we measured basal area of living mature trees before and 4 and 8 years after treatment applications. Soil and foliar chemistry variables were also measured. Dolomitic limestone increased Ca, Mg, and pH in the soil Oe horizon. Mg was increased in the B horizon when comparing the plots receiving N with those receiving CaMg. In mature trees, foliar Ca and Mg concentrations were higher in the CaMg and N+CaMg plots than in the reference or N plots; foliar Ca concentration was higher in the N+CaMg plots compared with the CaMg plots, foliar Mg was higher in the CaMg plots than the N+CaMg plots; An-max was maximized due to N+CaMg treatment; A qe decreased by N addition; and PAR at An-max increased by N or CaMg treatments alone, but the increase was maximized by their combination. No treatment effect was detected on basal areas of living mature trees four or eight years after treatment applications. In seedlings, An-max was increased by N+CaMg addition. The reference plots had an open herbaceous layer, but the plots receiving N had a dense monoculture of common woodfern in the forest floor

Photosynthetic and growth response of sugar maple (Acer saccharum Marsh.) mature trees and seedlings to calcium, magnesium, and nitrogen additions in the Catskill Mountains, NY, USA

USGS Publications Warehouse

Momen, Bahram; Behling, Shawna J; Lawrence, Gregory B.; Sullivan, Joseph H

2015-01-01

Decline of sugar maple in North American forests has been attributed to changes in soil calcium (Ca) and nitrogen (N) by acidic precipitation. Although N is an essential and usually a limiting factor in forests, atmospheric N deposition may cause N-saturation leading to loss of soil Ca. Such changes can affect carbon gain and growth of sugar maple trees and seedlings. We applied a 22 factorial arrangement of N and dolomitic limestone containing Ca and Magnesium (Mg) to 12 forest plots in the Catskill Mountain region of NY, USA. To quantify the short-term effects, we measured photosynthetic-light responses of sugar maple mature trees and seedlings two or three times during two summers. We estimated maximum net photosynthesis (An-max) and its related light intensity (PAR at An-max), apparent quantum efficiency (Aqe), and light compensation point (LCP). To quantify the long-term effects, we measured basal area of living mature trees before and 4 and 8 years after treatment applications. Soil and foliar chemistry variables were also measured. Dolomitic limestone increased Ca, Mg, and pH in the soil Oe horizon. Mg was increased in the B horizon when comparing the plots receiving N with those receiving CaMg. In mature trees, foliar Ca and Mg concentrations were higher in the CaMg and N+CaMg plots than in the reference or N plots; foliar Ca concentration was higher in the N+CaMg plots compared with the CaMg plots, foliar Mg was higher in the CaMg plots than the N+CaMg plots; An-max was maximized due to N+CaMg treatment; Aqe decreased by N addition; and PAR at An-max increased by N or CaMg treatments alone, but the increase was maximized by their combination. No treatment effect was detected on basal areas of living mature trees four or eight years after treatment applications. In seedlings, An-max was increased by N+CaMg addition. The reference plots had an open herbaceous layer, but the plots receiving N had a dense monoculture of common woodfern in the

Echinococcus granulosus in gray wolves and ungulates in Idaho and Montana, USA.

PubMed

Foreyt, William J; Drew, Mark L; Atkinson, Mark; McCauley, Deborah

2009-10-01

We evaluated the small intestines of 123 gray wolves (Canis lupus) that were collected from Idaho, USA (n=63), and Montana, USA (n=60), between 2006 and 2008 for the tapeworm Echinococcus granulosus. The tapeworm was detected in 39 of 63 wolves (62%) in Idaho, USA, and 38 of 60 wolves (63%) in Montana, USA. The detection of thousands of tapeworms per wolf was a common finding. In Idaho, USA, hydatid cysts, the intermediate form of E. granulosus, were detected in elk (Cervus elaphus), mule deer (Odocoileus hemionus), and a mountain goat (Oreamnos americanus). In Montana, USA, hydatid cysts were detected in elk. To our knowledge, this is the first report of adult E. granulosus in Idaho, USA, or Montana, USA. It is unknown whether the parasite was introduced into Idaho, USA, and southwestern Montana, USA, with the importation of wolves from Alberta, Canada, or British Columbia, Canada, into Yellowstone National Park, Wyoming, USA, and central Idaho, USA, in 1995 and 1996, or whether the parasite has always been present in other carnivore hosts, and wolves became a new definitive host. Based on our results, the parasite is now well established in wolves in these states and is documented in elk, mule deer, and a mountain goat as intermediate hosts.

Hydration kinetics of CA{sub 2} and CA-Investigations performed on a synthetic calcium aluminate cement

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

Klaus, S.R., E-mail: klaus@geol.uni-erlangen.de; Neubauer, J., E-mail: juergen.neubauer@gzn.uni-erlangen.de; Goetz-Neunhoeffer, F., E-mail: friedlinde.goetz@gzn.uni-erlangen.de

2013-01-15

Much is already known about the hydration of monocalcium aluminate (CA) in calcium aluminate cements (CACs). CA{sub 2} is known to be weakly hydraulic. Therefore, the hydration kinetics of CA{sub 2} were not of as great interest as those of the hydration of CAC. We were able to show that the hydration of CA{sub 2} begins as soon as the hydration rate of CA has reached its maximum and the first precipitation of C{sub 2}AH{sub 8} has started. The hydration of different CA/CA{sub 2} ratios was analyzed by the G-factor quantification. The individual contributions of the phases CA and CA{submore » 2} to the heat flow were calculated based on the amounts dissolved by applying thermodynamic data. The heat flow as calculated from XRD data was then compared with the measured heat flow. It obtained a good consistency between the two. The very pronounced influence of CA{sub 2} during hydration of CAC can be clearly demonstrated.« less

Oestrogen directly inhibits the cardiovascular L-type Ca{sup 2+} channel Ca{sub v}1.2

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

Ullrich, Nina D.; Koschak, Alexandra; MacLeod, Kenneth T.

2007-09-21

Oestrogen can modify the contractile function of vascular smooth muscle and cardiomyocytes. The negative inotropic actions of oestrogen on the heart and coronary vasculature appear to be mediated by L-type Ca{sup 2+} channel (Ca{sub v}1.2) inhibition, but the underlying mechanisms remain elusive. We tested the hypothesis that oestrogen directly inhibits the cardiovascular L-type Ca{sup 2+} current, I {sub CaL}. The effect of oestrogen on I {sub CaL} was measured in Ca{sub v}1.2-transfected HEK-293 cells using the whole-cell patch-clamp technique. The current revealed typical activation and inactivation profiles of nifedipine- and cadmium-sensitive I {sub CaL}. Oestrogen (50 {mu}M) rapidly reduced Imore » {sub CaL} by 50% and shifted voltage-dependent activation and availability to more negative potentials. Furthermore, oestrogen blocked the Ca{sup 2+} channel in a rate-dependent way, exhibiting higher efficiency of block at higher stimulation frequencies. Our data suggest that oestrogen inhibits I {sub CaL} through direct interaction of the steroid with the channel protein.« less

Comparison of the diagnostic accuracy of CA27.29 and CA15.3 in primary breast cancer.

PubMed

Gion, M; Mione, R; Leon, A E; Dittadi, R

1999-05-01

A new, fully automated method that measures the breast cancer-associated glycoprotein CA27.29 has become commercially available. The aim of the present study was to compare this CA27.29 assay with the assay that measures CA15.3 in primary breast cancer. The study was performed retrospectively on preoperative serum samples collected from 275 patients with untreated primary breast cancer (154 node positive and 121 node negative). Eighty-three healthy control subjects were also evaluated. CA27.29 was measured using the fully automated Chiron Diagnostics immunochemiluminescent system (ACS:180 BR). CA15.3 was measured with a manual immunoradiometric method (Centocor CA15.3 RIA). In healthy subjects, CA15.3 was significantly higher than CA27.29 (P <0. 0001). On the other hand, in breast cancer patients CA27.29 was higher than CA15.3 (P = 0.013). The mean value found in the control group plus 2 SD was chosen as the positive/negative cutoff point. The overall positivity rates were 34.9% for CA27.29 and 22.5% for CA15.3. The area under the ROC curve was greater (P <0.001) for CA27. 29 (0.72) than for CA15.3 (0.61). Both markers showed a statistically significant, direct relationship, with pathological stage being higher in node-positive than in node-negative cases and in larger than in smaller tumors. Neither CA27.29 nor CA15.3 showed significant associations with age, menopausal status, or tumor receptor status. CA27.29 discriminates primary breast cancer from healthy subjects better than CA15.3, especially in patients with limited disease. Prospective studies are necessary to confirm this conclusion. Copyright 1999 American Association for Clinical Chemistry.

Nicergoline inhibits T-type Ca2+ channels in rat isolated hippocampal CA1 pyramidal neurones.

PubMed Central

Takahashi, K.; Akaike, N.

1990-01-01

1. The effects of nicergoline on the T- and L-type Ca2+ currents in pyramidal cells freshly isolated from rat hippocampal CA1 region were investigated by use of a 'concentration-clamp' technique. The technique combines a suction-pipette technique, which allows intracellular perfusion under a single-electrode voltage-clamp, and rapid exchange of extracellular solution within 2 ms. 2. T-type Ca2+ currents were evoked by step depolarizations from a holding potential of -100 mV to potentials more positive than -70 to -60 mV, and reached a peak at about -30 mV in the current-voltage relationship. Activation and inactivation of T-type Ca2+ currents were highly potential-dependent. 3. Nicergoline and other Ca2+ antagonists dose-dependently blocked the T-type Ca2+ channel with an order of potency nicardipine greater than nicergoline greater than diltiazem. 4. The L-type Ca2+ channel was also blocked in the order nicardipine greater than nicergoline greater than diltiazem, although the T-type Ca2+ channel was more sensitive to nicergoline. 5. The inhibitory effects of nicergoline and nicardipine on the T-type Ca2+ current were voltage-, time-, and use-dependent, and the inhibition increased with a decrease in the external Ca2+ concentration. Diltiazem showed only a use-dependent block. PMID:2169937

Nicergoline inhibits T-type Ca2+ channels in rat isolated hippocampal CA1 pyramidal neurones.

PubMed

Takahashi, K; Akaike, N

1990-08-01

1. The effects of nicergoline on the T- and L-type Ca2+ currents in pyramidal cells freshly isolated from rat hippocampal CA1 region were investigated by use of a 'concentration-clamp' technique. The technique combines a suction-pipette technique, which allows intracellular perfusion under a single-electrode voltage-clamp, and rapid exchange of extracellular solution within 2 ms. 2. T-type Ca2+ currents were evoked by step depolarizations from a holding potential of -100 mV to potentials more positive than -70 to -60 mV, and reached a peak at about -30 mV in the current-voltage relationship. Activation and inactivation of T-type Ca2+ currents were highly potential-dependent. 3. Nicergoline and other Ca2+ antagonists dose-dependently blocked the T-type Ca2+ channel with an order of potency nicardipine greater than nicergoline greater than diltiazem. 4. The L-type Ca2+ channel was also blocked in the order nicardipine greater than nicergoline greater than diltiazem, although the T-type Ca2+ channel was more sensitive to nicergoline. 5. The inhibitory effects of nicergoline and nicardipine on the T-type Ca2+ current were voltage-, time-, and use-dependent, and the inhibition increased with a decrease in the external Ca2+ concentration. Diltiazem showed only a use-dependent block.

Point-of-care: being a pilot site. Interview by Bill W. Childs.

PubMed

Bills, J

1988-11-01

Scripps Memorial Hospital in Chula Vista, CA, a 159-bed acute care facility, opened in 1964. The facility was acquired in 1986 by the Scripps Memorial Hospitals family which has acute care facilities in La Jolla, Encinitas and Chula Vista, CA. Prior to 1986, the hospital was in severe financial difficulty and was very near to closing its doors. With the help of an excellent group of employees and medical staff, Scripps Memorial Hospital--Chula Vista has made significant changes in all aspects of the operation. The CliniCom pilot program is only one of many changes the hospital has introduced in its effort to continue its role as a major healthcare provider in the South Bay area of San Diego. Scripps Memorial Hospital--Chula Vista is a very active facility with 85 percent occupancy, 32,000 emergency visits and 4,200 deliveries a year. The hospital is planning an expansion program to meet the current and future needs of the community.

Optically stimulated luminescence age controls on late Pleistocene and Holocene coastal lithosomes, North Carolina, USA

USGS Publications Warehouse

Mallinson, D.; Burdette, K.; Mahan, S.; Brook, G.

2008-01-01

Luminescence ages from a variety of coastal features on the North Carolina Coastal Plain provide age control for shoreline formation and relative sea-level position during the late Pleistocene. A series of paleoshoreline ridges, dating to Marine Isotope Stage (MIS) 5a and MIS 3 have been defined. The Kitty Hawk beach ridges, on the modern Outer Banks, yield ages of 3 to 2??ka. Oxygen-isotope data are used to place these deposits in the context of global climate and sea-level change. The occurrence of MIS 5a and MIS 3 shorelines suggests that glacio-isostatic adjustment (GIA) of the study area is large (ca. 22 to 26??m), as suggested and modeled by other workers, and/or MIS 3 sea level was briefly higher than suggested by some coral reef studies. Correcting the shoreline elevations for GIA brings their elevation in line with other sea-level indicators. The age of the Kitty Hawk beach ridges places the Holocene shoreline well west of its present location at ca. 3 to 2??ka. The age of shoreline progradation is consistent with the ages of other beach ridge complexes in the southeast USA, suggesting some regionally contemporaneous forcing mechanism. ?? 2007 University of Washington.

Activation of the Ca2+-sensing receptor increases renal claudin-14 expression and urinary Ca2+ excretion

PubMed Central

Dimke, Henrik; Desai, Prajakta; Borovac, Jelena; Lau, Alyssa; Pan, Wanling; Alexander, R. Todd

2016-01-01

Kidney stones are a prevalent clinical condition imposing a large economic burden on the health-care system. Hypercalciuria remains the major risk factor for development of a Ca2+-containing stone. The kidney’s ability to alter Ca2+ excretion in response to changes in serum Ca2+ is in part mediated by the Ca2+-sensing receptor (CaSR). Recent studies revealed renal claudin-14 (Cldn14) expression localized to the thick ascending limb (TAL) and its expression to be regulated via the CaSR. We find that Cldn14 expression is increased by high dietary Ca2+ intake and by elevated serum Ca2+ levels induced by prolonged 1,25-dihydroxyvitamin D3 administration. Consistent with this, activation of the CaSR in vivo via administration of the calcimimetic cinacalcet hydrochloride led to a 40-fold increase in Cldn14 mRNA. Moreover, overexpression of Cldn14 in two separate cell culture models decreased paracellular Ca2+ flux by preferentially decreasing cation permeability, thereby increasing transepithelial resistance. These data support the existence of a mechanism whereby activation of the CaSR in the TAL increases Cldn14 expression, which in turn blocks the paracellular reabsorption of Ca2+. This molecular mechanism likely facilitates renal Ca2+ losses in response to elevated serum Ca2+. Moreover, dys-regulation of the newly described CaSR-Cldn14 axis likely contributes to the development of hypercalciuria and kidney stones. PMID:23283989

"USA Today": Can the Nation's Newspaper Survive?

ERIC Educational Resources Information Center

Wicks, Robert H.

The failure of 17 newspaper markets between 1957 and 1975 raises the question of whether the 1982 entrance of "USA Today" into the newspaper market demonstrated fiscal prudence. A 20-month advertising content analysis was conducted to assess advertising trends in "USA Today." These data were compared with industry statistics…

NATIONAL GEODATABASE OF TIDAL STREAM POWER RESOURCE IN USA

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

Smith, Brennan T; Neary, Vincent S; Stewart, Kevin M

2012-01-01

A geodatabase of tidal constituents is developed to present the regional assessment of tidal stream power resource in the USA. Tidal currents are numerically modeled with the Regional Ocean Modeling System (ROMS) and calibrated with the available measurements of tidal current speeds and water level surfaces. The performance of the numerical model in predicting the tidal currents and water levels is assessed by an independent validation. The geodatabase is published on a public domain via a spatial database engine with interactive tools to select, query and download the data. Regions with the maximum average kinetic power density exceeding 500 W/m2more » (corresponding to a current speed of ~1 m/s), total surface area larger than 0.5 km2 and depth greater than 5 m are defined as hotspots and documented. The regional assessment indicates that the state of Alaska (AK) has the largest number of locations with considerably high kinetic power density, followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL).« less

Enhanced heavy metal immobilization in soil by grinding with addition of nanometallic Ca/CaO dispersion mixture.

PubMed

Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Kakeda, Mitsunori

2012-10-01

This study investigated the use of a nanometallic Ca and CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb) in contaminated soil. Simple grinding achieved 85-90% heavy metal immobilization, but it can be enhanced further to 98-100% by addition of a nanometallic Ca/CaO dispersion mixture produced by grinding. Observations using SEM-EDS elemental maps and semi-quantitative analysis showed that the amounts of As, Cd, Cr, and Pb measurable on the soil particle surface decrease after nanometallic Ca/CaO treatment. The leachable heavy metal concentrations were reduced after nanometallic Ca/CaO treatment to concentrations lower than the Japan soil elution standard regulatory threshold: <0.01 mg L(-1) for As, Cd, and Pb; and 0.05 mg L(-1) for Cr. Effects of soil moisture and pH on heavy metal immobilization were not strongly influenced. The most probable mechanisms for the enhancement of heavy metal immobilization capacity with nanometallic Ca/CaO treatment might be due to adsorption and entrapment of heavy metals into newly formed aggregates, thereby prompting aggregation of soil particles and enclosure/binding with Ca/CaO-associated immobile salts. Results suggest that the nanometallic Ca/CaO mixture is suitable for use in immobilization of heavy-metal-contaminated soil under normal moisture conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

77 FR 47671 - TA-W-81,520, T-Mobile USA, Inc., Call Center, Allentown, PA; TA-W-81,520G, T-Mobile USA, Inc...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

... DEPARTMENT OF LABOR Employment and Training Administration TA-W-81,520, T-Mobile USA, Inc., Call Center, Allentown, PA; TA- W-81,520G, T-Mobile USA, Inc., Headquarters Office, Bellevue, WA; Amended... of T-Mobile USA, Inc., Call Center, Allentown, Pennsylvania (TA-W-81,520), Fort Lauderdale, Florida...

Periostin and CA242 as potential diagnostic serum biomarkers complementing CA19.9 in detecting pancreatic cancer.

PubMed

Dong, Dong; Jia, Li; Zhang, Lufang; Ma, Na; Zhang, Aimin; Zhou, Yunli; Ren, Li

2018-06-26

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with few biomarkers to guide treatment options. Carbohydrate antigen 19.9 (CA19.9), the mainly used biomarker for PDAC, is not sensitive and specific enough for the detection of the disease. This study was aimed to evaluate serum periostin (POSTN) and CA242 as potential diagnostic biomarkers complementing CA19.9 in detecting pancreatic cancer. Blood samples were from 362 participants, including 213 patients with different stages of PDAC, 75 patients with benign pancreatic disease and 74 healthy individuals. All samples were randomly divided into training set and validation set. CA19.9, CA242, POSTN, as well as carcinoembryonic antigen (CEA), were measured by ELISA or automated immunoassay. The receiver operating curve (ROC) analysis revealed that the performances of CA19.9 in the validation group were improved by the marker panel composed of CA19.9, POSTN and CA242, to discriminate early-stage PDAC not only from healthy controls (AUC CA 19.9 = 0.94 vs. AUC CA 19.9 + POSTN + CA 242 = 0.98, P < 0.05) but also from benign conditions (AUC CA 19.9 = 0.87 vs. AUC CA 19.9 + POSTN + CA 242 = 0.90, P < 0.05). In addition, POSTN retained significant diagnostic capabilities to distinguish PDAC CA19.9-negative from healthy controls (AUC POSTN = 0.87) as well as from benign conditions (AUC POSTN = 0.84) in the whole set. This study suggested that POSTN and CA242 are potential diagnostic serum biomarkers complementing CA19.9 in detecting early pancreatic cancer. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Combining fragment homology modeling with molecular dynamics aims at prediction of Ca2+ binding sites in CaBPs

NASA Astrophysics Data System (ADS)

Pang, ChunLi; Cao, TianGuang; Li, JunWei; Jia, MengWen; Zhang, SuHua; Ren, ShuXi; An, HaiLong; Zhan, Yong

2013-08-01

The family of calcium-binding proteins (CaBPs) consists of dozens of members and contributes to all aspects of the cell's function, from homeostasis to learning and memory. However, the Ca2+-binding mechanism is still unclear for most of CaBPs. To identify the Ca2+-binding sites of CaBPs, this study presented a computational approach which combined the fragment homology modeling with molecular dynamics simulation. For validation, we performed a two-step strategy as follows: first, the approach is used to identify the Ca2+-binding sites of CaBPs, which have the EF-hand Ca2+-binding site and the detailed binding mechanism. To accomplish this, eighteen crystal structures of CaBPs with 49 Ca2+-binding sites are selected to be analyzed including calmodulin. The computational method identified 43 from 49 Ca2+-binding sites. Second, we performed the approach to large-conductance Ca2+-activated K+ (BK) channels which don't have clear Ca2+-binding mechanism. The simulated results are consistent with the experimental data. The computational approach may shed some light on the identification of Ca2+-binding sites in CaBPs.

Interfacial Ferromagnetism and Exchange Bias in CaRuO3/CaMnO3 Superlattices

NASA Astrophysics Data System (ADS)

He, C.; Grutter, A. J.; Gu, M.; Browning, N. D.; Takamura, Y.; Kirby, B. J.; Borchers, J. A.; Kim, J. W.; Fitzsimmons, M. R.; Zhai, X.; Mehta, V. V.; Wong, F. J.; Suzuki, Y.

2012-11-01

We have found ferromagnetism in epitaxially grown superlattices of CaRuO3/CaMnO3 that arises in one unit cell at the interface. Scanning transmission electron microscopy and electron energy loss spectroscopy indicate that the difference in magnitude of the Mn valence states between the center of the CaMnO3 layer and the interface region is consistent with double exchange interaction among the Mn ions at the interface. Polarized neutron reflectivity and the CaMnO3 thickness dependence of the exchange bias field together indicate that the interfacial ferromagnetism is only limited to one unit cell of CaMnO3 at each interface. The interfacial moment alternates between the 1μB/interface Mn ion for even CaMnO3 layers and the 0.5μB/interface Mn ion for odd CaMnO3 layers. This modulation, combined with the exchange bias, suggests the presence of a modulating interlayer coupling between neighboring ferromagnetic interfaces via the antiferromagnetic CaMnO3 layers.

Multifaceted plasma membrane Ca(2+) pumps: From structure to intracellular Ca(2+) handling and cancer.

PubMed

Padányi, Rita; Pászty, Katalin; Hegedűs, Luca; Varga, Karolina; Papp, Béla; Penniston, John T; Enyedi, Ágnes

2016-06-01

Plasma membrane Ca(2+) ATPases (PMCAs) are intimately involved in the control of intracellular Ca(2+) concentration. They reduce Ca(2+) in the cytosol not only by direct ejection, but also by controlling the formation of inositol-1,4,5-trisphosphate and decreasing Ca(2+) release from the endoplasmic reticulum Ca(2+) pool. In mammals four genes (PMCA1-4) are expressed, and alternative RNA splicing generates more than twenty variants. The variants differ in their regulatory characteristics. They localize into highly specialized membrane compartments and respond to the incoming Ca(2+) with distinct temporal resolution. The expression pattern of variants depends on cell type; a change in this pattern can result in perturbed Ca(2+) homeostasis and thus altered cell function. Indeed, PMCAs undergo remarkable changes in their expression pattern during tumorigenesis that might significantly contribute to the unbalanced Ca(2+) homeostasis of cancer cells. This article is part of a Special Issue entitled: Calcium and Cell Fate. Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen. Copyright © 2015 Elsevier B.V. All rights reserved.

GPI-anchored GFP signals Ca2+ but is homogeneously distributed on the cell surface.

PubMed

Hiscox, Stephen; Hallett, Maurice B; Morgan, B Paul; van den Berg, Carmen W

2002-05-03

Glycosyl-phosphatidylinositol (GPI)-anchored proteins are unique in that they penetrate only the outer leaflet of the plasma membrane but are still able to mediate intracellular signalling events following antibody-induced ligation. Detergent solubilisation studies suggest that microdomains exist at the cell surface within which are sequestered GPI-linked proteins. Here we report the construction and expression of a fluorescent GPI anchor on the surface of CHO, EL4, and U937 cells by fusing green fluorescent protein (GFP) to the GPI-attachment site of CD59. The resultant GFP-GPI has properties comparable to that of endogenously expressed GPI-anchored molecules as shown by Triton X-114 partitioning. However, sucrose gradient floatation showed that GFP-GPI was only partially resistant to detergent solubilisation. Furthermore confocal scanning laser microscopy revealed a homogeneous distribution of GFP-GPI at the cell surface, which only became clustered following cross-linking of the GPI anchor via an anti-GFP antibody. Surprisingly, GFP-GPI signalled Ca2+ change upon cross-linking demonstrating its signalling competence. Our results suggest that the GPI-anchor itself does not confer a clustered distribution to molecules but that clustering occurs following ligation with antibody, which allows the protein to become Ca2+ signalling competent. Copyright 2002 Elsevier Science (USA).

Spontaneous Ca2+ sparks and Ca2+ homeostasis in a minimal model of permeabilized ventricular myocytes

PubMed Central

Hartman, Jana M.; Sobie, Eric A.

2010-01-01

Many issues remain unresolved concerning how local, subcellular Ca2+ signals interact with bulk cellular concentrations to maintain homeostasis in health and disease. To aid in the interpretation of data obtained in quiescent ventricular myocytes, we present here a minimal whole cell model that accounts for both localized (subcellular) and global (cellular) aspects of Ca2+ signaling. Using a minimal formulation of the distribution of local [Ca2+] associated with a large number of Ca2+-release sites, the model simulates both random spontaneous Ca2+ sparks and the changes in myoplasmic and sarcoplasmic reticulum (SR) [Ca2+] that result from the balance between stochastic release and reuptake into the SR. Ca2+-release sites are composed of clusters of two-state ryanodine receptors (RyRs) that exhibit activation by local cytosolic [Ca2+] but no inactivation or regulation by luminal Ca2+. Decreasing RyR open probability in the model causes a decrease in aggregate release flux and an increase in SR [Ca2+], regardless of whether RyR inhibition is mediated by a decrease in RyR open dwell time or an increase in RyR closed dwell time. The same balance of stochastic release and reuptake can be achieved, however, by either high-frequency/short-duration or low-frequency/long-duration Ca2+ sparks. The results are well correlated with recent experimental observations using pharmacological RyR inhibitors and clarify those aspects of the release-reuptake balance that are inherent to the coupling between local and global Ca2+ signals and those aspects that depend on molecular-level details. The model of Ca2+ sparks and homeostasis presented here can be a useful tool for understanding changes in cardiac Ca2+ release resulting from drugs, mutations, or acquired diseases. PMID:20852058

Ca(2+) homeostasis in the budding yeast Saccharomyces cerevisiae: Impact of ER/Golgi Ca(2+) storage.

PubMed

D'hooge, Petra; Coun, Catherina; Van Eyck, Vincent; Faes, Liesbeth; Ghillebert, Ruben; Mariën, Lore; Winderickx, Joris; Callewaert, Geert

2015-08-01

Yeast has proven to be a powerful tool to elucidate the molecular aspects of several biological processes in higher eukaryotes. As in mammalian cells, yeast intracellular Ca(2+) signalling is crucial for a myriad of biological processes. Yeast cells also bear homologs of the major components of the Ca(2+) signalling toolkit in mammalian cells, including channels, co-transporters and pumps. Using yeast single- and multiple-gene deletion strains of various plasma membrane and organellar Ca(2+) transporters, combined with manipulations to estimate intracellular Ca(2+) storage, we evaluated the contribution of individual transport systems to intracellular Ca(2+) homeostasis. Yeast strains lacking Pmr1 and/or Cod1, two ion pumps implicated in ER/Golgi Ca(2+) homeostasis, displayed a fragmented vacuolar phenotype and showed increased vacuolar Ca(2+) uptake and Ca(2+) influx across the plasma membrane. In the pmr1Δ strain, these effects were insensitive to calcineurin activity, independent of Cch1/Mid1 Ca(2+) channels and Pmc1 but required Vcx1. By contrast, in the cod1Δ strain increased vacuolar Ca(2+) uptake was not affected by Vcx1 deletion but was largely dependent on Pmc1 activity. Our analysis further corroborates the distinct roles of Vcx1 and Pmc1 in vacuolar Ca(2+) uptake and point to the existence of not-yet identified Ca(2+) influx pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neuronal-specific endoplasmic reticulum Mg(2+)/Ca(2+) ATPase Ca(2+) sequestration in mixed primary hippocampal culture homogenates.

PubMed

Parsons, J Travis; Sun, David A; DeLorenzo, Robert J; Churn, Severn B

2004-07-01

Endoplasmic reticulum Mg(2+)/Ca(2+) ATPase Ca(2+) sequestration is crucial for maintenance of neuronal Ca(2+) homeostasis. The use of cell culture in conjunction with modern Ca(2+) imaging techniques has been invaluable in elucidating these mechanisms. While imaging protocols evaluate endoplasmic reticulum Ca(2+) loads, measurement of Mg(2+)/Ca(2+) ATPase activity is indirect, comparing cytosolic Ca(2+) levels in the presence or absence of the Mg(2+)/Ca(2+) ATPase inhibitor thapsigargin. Direct measurement of Mg(2+)/Ca(2+) ATPase by isolation of microsomes is impossible due to the minuscule amounts of protein yielded from cultures used for imaging. In the current study, endoplasmic reticulum Mg(2+)/Ca(2+) ATPase Ca(2+) sequestration was measured in mixed homogenates of neurons and glia from primary hippocampal cultures. It was demonstrated that Ca(2+) uptake was mediated by the endoplasmic reticulum Mg(2+)/Ca(2+) ATPase due to its dependence on ATP and Mg(2+), enhancement by oxalate, and inhibition by thapsigargin. It was also shown that neuronal Ca(2+) uptake, mediated by the type 2 sarco(endo)plasmic reticulum Ca(2+) ATPase isoform, could be distinguished from glial Ca(2+) uptake in homogenates composed of neurons and glia. Finally, it was revealed that Ca(2+) uptake was sensitive to incubation on ice, extremely labile in the absence of protease inhibitors, and significantly more stable under storage conditions at -80 degrees C.

Interface ferromagnetism in oxide superlattices of CaMnO3/CaRuO3

NASA Astrophysics Data System (ADS)

Takahashi, K. S.; Kawasaki, M.; Tokura, Y.

2001-08-01

Oxide superlattices composed of antiferromagnetic insulator layers of CaMnO3 (10 unit cells) and paramagnetic metal layers of CaRuO3 (N unit cells) were fabricated on LaAlO3 substrates by pulsed-laser deposition. All the superlattices show ferromagnetic transitions at an almost identical temperature (TC˜95 K) and negative magnetoresistance below TC. Each magnetization and magnetoconductance of the whole superlattice at 5 K is constant and independent of CaRuO3 layer thickness when normalized by the number of the interfaces between CaMnO3 and CaRuO3. These results indicate that the ferromagnetism shows up only at the interface and is responsible for the magnetoresistance.

Tracing Cytoplasmic Ca2+ Ion and Water Access Points in the Ca2+-ATPase

PubMed Central

Musgaard, Maria; Thøgersen, Lea; Schiøtt, Birgit; Tajkhorshid, Emad

2012-01-01

Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) transports two Ca2+ ions across the membrane of the sarco(endo)plasmic reticulum against the concentration gradient, harvesting the required energy by hydrolyzing one ATP molecule during each transport cycle. Although SERCA is one of the best structurally characterized membrane transporters, it is still largely unknown how the transported Ca2+ ions reach their transmembrane binding sites in SERCA from the cytoplasmic side. Here, we performed extended all-atom molecular dynamics simulations of SERCA. The calculated electrostatic potential of the protein reveals a putative mechanism by which cations may be attracted to and bind to the Ca2+-free state of the transporter. Additional molecular dynamics simulations performed on a Ca2+-bound state of SERCA reveal a water-filled pathway that may be used by the Ca2+ ions to reach their buried binding sites from the cytoplasm. Finally, several residues that are involved in attracting and guiding the cations toward the possible entry channel are identified. The results point to a single Ca2+ entry site close to the kinked part of the first transmembrane helix, in a region loaded with negatively charged residues. From this point, a water pathway outlines a putative Ca2+ translocation pathway toward the transmembrane ion-binding sites. PMID:22339863

Muscle aging is associated with compromised Ca2+ spark signaling and segregated intracellular Ca2+ release

PubMed Central

Weisleder, Noah; Brotto, Marco; Komazaki, Shinji; Pan, Zui; Zhao, Xiaoli; Nosek, Thomas; Parness, Jerome; Takeshima, Hiroshi; Ma, Jianjie

2006-01-01

Reduced homeostatic capacity for intracellular Ca2+ ([Ca2+]i) movement may underlie the progression of sarcopenia and contractile dysfunction during muscle aging. We report two alterations to Ca2+ homeostasis in skeletal muscle that are associated with aging. Ca2+ sparks, which are the elemental units of Ca2+ release from sarcoplasmic reticulum, are silent under resting conditions in young muscle, yet activate in a dynamic manner upon deformation of membrane structures. The dynamic nature of Ca2+ sparks appears to be lost in aged skeletal muscle. Using repetitive voltage stimulation on isolated muscle preparations, we identify a segregated [Ca2+]i reserve that uncouples from the normal excitation–contraction process in aged skeletal muscle. Similar phenotypes are observed in adolescent muscle null for a synaptophysin-family protein named mitsugumin-29 (MG29) that is involved in maintenance of muscle membrane ultrastructure and Ca2+ signaling. This finding, coupled with decreased expression of MG29 in aged skeletal muscle, suggests that MG29 expression is important in maintaining skeletal muscle Ca2+ homeostasis during aging. PMID:16943181

Superoxide anion radical-triggered Ca2+ release from cardiac sarcoplasmic reticulum through ryanodine receptor Ca2+ channel.

PubMed

Kawakami, M; Okabe, E

1998-03-01

The ryanodine receptor Ca2+ channel (RyRC) constitutes the Ca2+-release pathway in sarcoplasmic reticulum (SR) of cardiac muscle. A direct mechanical and a Ca2+-triggered mechanism (Ca2+-induced Ca2+ release) have been proposed to explain the in situ activation of Ca2+ release in cardiac muscle. A variety of chemical oxidants have been shown to activate RyRC; however, the role of modification induced by oxygen-derived free radicals in pathological states of the muscle remains to be elucidated. It has been hypothesized that oxygen-derived free radicals initiate Ca2+-mediated functional changes in or damage to cardiac muscle by acting on the SR and promoting an increase in Ca2+ release. We confirmed that superoxide anion radical (O2-) generated from hypoxanthine-xanthine oxidase reaction decreases calmodulin content and increases 45Ca2+ efflux from the heavy fraction of canine cardiac SR vesicles; hypoxanthine-xanthine oxidase also decreases Ca2+ free within the intravesicular space of the SR with no effect on Ca2+-ATPase activity. Current fluctuations through single Ca2+-release channels have been monitored after incorporation into planar phospholipid bilayers. We demonstrate that activation of the channel by O2- is dependent of the presence of calmodulin and identified calmodulin as a functional mediator of O2--triggered Ca2+ release through the RyRC. For the first time, we show that O2- stimulates Ca2+ release from heavy SR vesicles and suggest the importance of accessory proteins such as calmodulin in modulating the effect of O2-. The decreased calmodulin content induced by oxygen-derived free radicals, especially O2-, is a likely mechanism of accumulation of cytosolic Ca2+ (due to increased Ca2+ release from SR) after reperfusion of the ischemic heart.

Evolving plans for the USA National Phenology Network

USGS Publications Warehouse

Betancourt, Julio L.; Schwartz, Mark D.; Breshears, David D.; Brewer, Carol A.; Frazer, Gary; Gross, John E.; Mazer, Susan J.; Reed, Bradley C.; Wilson, Bruce E.

2007-01-01

Phenology is the study of periodic plant and animal life cycle events, how these are influenced by seasonal and interannual variations in climate, and how they modulate the abundance, diversity, and interactions of organisms. The USA National Phenology Network (USA-NPN) is currently being organized to engage federal agencies, environmental networks and field stations, educational institutions, and citizen scientists. The first USA-NPN planning workshop was held August 2005, in Tucson, Ariz. (Betancourt et al. [2005]; http://www.uwm.edu/Dept/Geography/npn/; by 1 June 2007, also see http://www.usanpn.org). With sponsorship from the U.S. National Science Foundation, the U.S. Geological Survey (USGS), the U.S. Fish and Wildlife Service, and NASA, the second USA-NPN planning workshop was held at the University of Wisconsin-Milwaukee on 10–12 October 2006 to (1) develop lists of target species and observation protocols; (2) identify existing networks that could comprise the backbone of nationwide observations by 2008; (3) develop opportunities for education, citizen science, and outreach beginning in spring 2007; (4) design strategies for implementing the remote sensing component of USA-NPN; and (5) draft a data management and cyberinfrastructure plan.

The Sixth U.S.A. Mathematical Olympiad

ERIC Educational Resources Information Center

Greitzer, Samuel L.

1978-01-01

One hundred and seven students of 365,000 students given the annual High School Mathematics Examination took part in the sixth U.S.A. Mathematical Olympiad. The top eight scores are listed along with comparative Exam and Olympiad scores for the group and individual problem scores. The problems proposed on the U.S.A. Olympiad on an International…

The Electronic Spectra of CaN2(+) and Ca(N2)2(+)

NASA Technical Reports Server (NTRS)

Rodriguez-Santiago, Luis; Bauschlicher, Charles W., Jr.; Arnold, James (Technical Monitor)

1998-01-01

The ground and low-lying electronic states of CaN2(+) are studied at several levels of theory. The results for the X(sup 2)Sigma(+) state and the excited (2)(sup 2)Pi state, arising from occupying the Ca 4p orbital, are in good agreement with experiment. The analogous states of Ca(N2)2(+) are studied using the same theoretical approaches, and predictions are made as to the changes caused by the addition of the second N2 ligand.

Growth and nutrition of baldcypress families planted under varying salinity regimes in Louisiana, USA

USGS Publications Warehouse

Krauss, K.W.; Chambers, J.L.; Allen, J.A.; Soileau, D.M.; DeBosier, A.S.

2000-01-01

Saltwater intrusion from the Gulf of Mexico is one important factor in the destruction of baldcypress (Taxodium distichum (L.) Rich.) swamps along the Louisiana Gulf Coast, USA. Recent restoration efforts have focused on identification of baldcypress genotypes with greater tolerance to saline conditions than previously reported. To date, salt tolerance investigations have not been conducted under saline field conditions. In 1996, therefore, three plantations were established with 10 half-sib genotype collections of baldcypress in mesohaline wetlands. Tree survival and growth were measured at the end of two growing seasons, and foliar ion concentrations of Na, Cl, K, and Ca and available soil nutrients were measured during the 1996 growing season. In general, soil nutrient concentrations exceeded averages found in other baldcypress stands in the southeastern United States. Seedlings differed among sites in all parameters measured, with height, diameter, foliar biomass, and survival decreasing as site salinity increased. Average seedling height at the end of two years, for example, was 196.4 cm on the lowest salinity site and 121.6 cm on the highest. Several half-sib families maintained greater height growth increments (ranging from 25.5 to 54.5 cm on the highest salinity site), as well as lower foliar ion concentrations of K, Cl, and Ca. Results indicate that genotypic screening of baldcypress may improve growth and vigor of seedlings planted within wetlands impacted by saltwater intrusion.

Quantifying uncertainty in coral Sr/Ca-based SST estimates from Orbicella faveolata: A basis for multi-colony SST reconstructions

NASA Astrophysics Data System (ADS)

Richey, J. N.; Flannery, J. A.; Toth, L. T.; Kuffner, I. B.; Poore, R. Z.

2017-12-01

The Sr/Ca in massive corals can be used as a proxy for sea surface temperature (SST) in shallow tropical to sub-tropical regions; however, the relationship between Sr/Ca and SST varies throughout the ocean, between different species of coral, and often between different colonies of the same species. We aimed to quantify the uncertainty associated with the Sr/Ca-SST proxy due to sample handling (e.g., micro-drilling or analytical error), vital effects (e.g., among-colony differences in coral growth), and local-scale variability in microhabitat. We examine the intra- and inter-colony reproducibility of Sr/Ca records extracted from five modern Orbicella faveolata colonies growing in the Dry Tortugas, Florida, USA. The average intra-colony absolute difference (AD) in Sr/Ca of the five colonies during an overlapping interval (1997-2008) was 0.055 ± 0.044 mmol mol-1 (0.96 ºC) and the average inter-colony Sr/Ca AD was 0.039 ± 0.01 mmol mol-1 (0.51 ºC). All available Sr/Ca-SST data pairs from 1997-2008 were combined and regressed against the HadISST1 gridded SST data set (24 ºN and 82 ºW) to produce a calibration equation that could be applied to O. faveolata specimens from throughout the Gulf of Mexico/Caribbean/Atlantic region after accounting for the potential uncertainties in Sr/Ca-derived SSTs. We quantified a combined error term for O. faveolata using the root-sum-square (RMS) of the analytical, intra-, and inter-colony uncertainties and suggest that an overall uncertainty of 0.046 mmol mol-1 (0.81 ºC, 1σ), should be used to interpret Sr/Ca records from O. faveolata specimens of unknown age or origin to reconstruct SST. We also explored how uncertainty is affected by the number of corals used in a reconstruction by iteratively calculating the RMS error for composite coral time-series using two, three, four, and five overlapping coral colonies. Our results indicate that maximum RMS error at the 95% confidence interval on mean annual SST estimates is 1.4 º

An Aqueous Ca-Ion Battery.

PubMed

Gheytani, Saman; Liang, Yanliang; Wu, Feilong; Jing, Yan; Dong, Hui; Rao, Karun K; Chi, Xiaowei; Fang, Fang; Yao, Yan

2017-12-01

Multivalent-ion batteries are emerging as low-cost, high energy density, and safe alternatives to Li-ion batteries but are challenged by slow cation diffusion in electrode materials due to the high polarization strength of Mg- and Al-ions. In contrast, Ca-ion has a low polarization strength similar to that of Li-ion, therefore a Ca-ion battery will share the advantages while avoiding the kinetics issues related to multivalent batteries. However, there is no battery known that utilizes the Ca-ion chemistry due to the limited success in Ca-ion storage materials. Here, a safe and low-cost aqueous Ca-ion battery based on a highly reversible polyimide anode and a high-potential open framework copper hexacyanoferrate cathode is demonstrated. The prototype cell shows a stable capacity and high efficiency at both high and low current rates, with an 88% capacity retention and an average 99% coloumbic efficiency after cycling at 10C for 1000 cycles. The Ca-ion storage mechanism for both electrodes as well as the origin of the fast kinetics have been investigated. Additional comparison with a Mg-ion cell with identical electrodes reveals clear kinetics advantages for the Ca-ion system, which is explained by the smaller ionic radii and more facile desolvation of hydrated Ca-ions.

ROS-activated Ca/calmodulin kinase IIδ is required for late INa augmentation leading to cellular Na and Ca overload

PubMed Central

Wagner, Stefan; Ruff, Hanna M.; Weber, Sarah L.; Bellmann, Sarah; Sowa, Thomas; Schulte, Timo; Grandi, Eleonora; Bers, Donald M.; Backs, Johannes; Belardinelli, Luiz; Maier, Lars S.

2011-01-01

Rationale In heart failure (HF), CaMKII expression and reactive oxygen species (ROS) are increased. Both ROS and CaMKII can increase late INa leading to intracellular Na accumulation and arrhythmias. It has been shown that ROS can activate CaMKII via oxidation. Objective We tested whether CaMKIIδ is required for ROS-dependent late INa regulation and if ROS-induced Ca released from the sarcoplasmic reticulum (SR) is involved. Methods and Results 40 µmol/L H2O2 significantly increased CaMKII oxidation and autophosphorylation in permeabilized rabbit cardiomyocytes. Without free [Ca]i (5 mmol/L BAPTA/1 mmol/L Br2-BAPTA) or after SR depletion (caffeine 10 mmol/L, thapsigargin 5 µmol/L) the H2O2-dependent CaMKII oxidation and autophosphorylation was abolished. H2O2 significantly increased SR Ca spark frequency (confocal microscopy) but reduced SR Ca load. In wildtype (WT) mouse myocytes, H2O2 increased late INa (whole cell patch-clamp). This increase was abolished in CaMKIIδ−/− myocytes. H2O2-induced [Na]i and [Ca]i accumulation (SBFI and Indo-1 epifluorescence) was significantly slowed in CaMKIIδ−/− myocytes (vs. WT). CaMKIIδ−/− myocytes developed significantly less H2O2-induced arrhythmias, and were more resistant to hypercontracture. Opposite results (increased late INa, [Na]i and [Ca]i accumulation) were obtained by overexpression of CaMKIIδ in rabbit myocytes (adenoviral gene transfer) reversible with CaMKII inhibition (10 µmol/L KN93 or 0.1 µmol/L AIP). Conclusion Free [Ca]i and a functional SR are required for ROS activation of CaMKII. ROS-activated CaMKIIδ enhances late INa, which may lead to cellular Na and Ca overload. This may be of relevance in HF, where enhanced ROS production meets increased CaMKII expression. PMID:21252154

A failed tentative to design a super carbonic anhydrase having the biochemical properties of the most thermostable CA (SspCA) and the fastest (SazCA) enzymes.

PubMed

De Luca, Viviana; Del Prete, Sonia; Carginale, Vincenzo; Vullo, Daniela; Supuran, Claudiu T; Capasso, Clemente

2015-12-01

Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze a simple reaction in all life domains: the carbon dioxide hydration to bicarbonate and protons: CO2 + H2O → [Formula: see text] + H(+). Six different, genetically distinct CA families are known to date, the α-, β-, γ-, δ-, ζ- and η-CAs. Bacteria encode for CAs belong to the α-, β- and γ-classes. Recently, our groups investigated the presence of CAs in two bacteria belonging to the genus Sulfurihydrogenibium living in hot springs all over the world, at temperatures of up to 110 °C. The α-CAs from Sulfurihydrogenibium yellowstonense and Sulfurihydrogenibium azorense, denominated SspCA and SazCA, respectively, are highly thermostable, maintaining a good catalytic activity even after being heated for a prolonged period. Moreover, SazCA was to be the fastest CA known to date with a kcat value of 4.40 × 10(6) s(-1) and a kcat/KM value of 3.5 × 10(8) M(-1) s(-1). SspCA also showed a good catalytic activity for the same reaction, with a kcat value of 9.35 × 10(5) s(-1) and a kcat/KM value of 1.1 × 10(8) M(-1) s(-1), proving that the "extremo-α-CAs" are between the most effective CAs known to date. Here, we describe a failed tentative to obtain a super-CA, SupCA, by combining the amino acid sequence of SazCA and SspCA. To achieve this goal we introduced six His residues in N-terminal sequence of SspCA. However the obtained SupCA showed lower catalytic activity and thermostability compared to both extremophilic enzymes from which it has been designed. We rationalized the biochemical reasons of this failure, which may be useful to design enzymes with a better catalytic activity.

Induction of CaSR expression circumvents the molecular features of malignant CaSR null colon cancer cells.

PubMed

Singh, Navneet; Chakrabarty, Subhas

2013-11-15

We recently reported on the isolation and characterization of calcium sensing receptor (CaSR) null human colon cancer cells (Singh et al., Int J Cancer 2013; 132: 1996-2005). CaSR null cells possess a myriad of molecular features that are linked to a highly malignant and drug resistant phenotype of colon cancer. The CaSR null phenotype can be maintained in defined human embryonic stem cell culture medium. We now show that the CaSR null cells can be induced to differentiate in conventional culture medium, regained the expression of CaSR with a concurrent reversal of the cellular and molecular features associated with the null phenotype. These features include cellular morphology, expression of colon cancer stem cell markers, expression of survivin and thymidylate synthase and sensitivity to fluorouracil. Other features include the expression of epithelial mesenchymal transition linked molecules and transcription factors, oncogenic miRNAs and tumor suppressive molecule and miRNA. With the exception of cancer stem cell markers, the reversal of molecular features, upon the induction of CaSR expression, is directly linked to the expression and function of CaSR because blocking CaSR induction by shRNA circumvented such reversal. We further report that methylation and demethylation of the CaSR gene promoter underlie CaSR expression. Due to the malignant nature of the CaSR null cells, inclusion of the CaSR null phenotype in disease management may improve on the mortality of this disease. Because CaSR is a robust promoter of differentiation and mediates its action through diverse mechanisms and pathways, inactivation of CaSR may serve as a new paradigm in colon carcinogenesis. Copyright © 2013 UICC.

Ab-initio calculations of the Ruddlesden Popper phases CaMnO3, CaO(CaMnO3) and CaO(CaMnO3)2

NASA Astrophysics Data System (ADS)

Cardoso, C.; Borges, R. P.; Gasche, T.; Godinho, M.

2008-01-01

The present work reports ab-initio density functional theory calculations for the Ruddlesden-Popper phase CaO(CaMnO3)n compounds. In order to study the evolution of the properties with the number of perovskite layers, a detailed analysis of the densities of states calculated for each compound and for several magnetic configurations was performed. The effect of distortions of the crystal structure on the magnetic ground state is also analysed and the exchange constants and transition temperatures are calculated for the three compounds using a mean field model. The calculated magnetic ground state structures and magnetic moments are in good agreement with experimental results and previous calculations.

Zea mays Annexins Modulate Cytosolic Free Ca2+ and Generate a Ca2+-Permeable Conductance[W

PubMed Central

Laohavisit, Anuphon; Mortimer, Jennifer C.; Demidchik, Vadim; Coxon, Katy M.; Stancombe, Matthew A.; Macpherson, Neil; Brownlee, Colin; Hofmann, Andreas; Webb, Alex A.R.; Miedema, Henk; Battey, Nicholas H.; Davies, Julia M.

2009-01-01

Regulation of reactive oxygen species and cytosolic free calcium ([Ca2+]cyt) is central to plant function. Annexins are small proteins capable of Ca2+-dependent membrane binding or membrane insertion. They possess structural motifs that could support both peroxidase activity and calcium transport. Here, a Zea mays annexin preparation caused increases in [Ca2+]cyt when added to protoplasts of Arabidopsis thaliana roots expressing aequorin. The pharmacological profile was consistent with annexin activation (at the extracellular plasma membrane face) of Arabidopsis Ca2+-permeable nonselective cation channels. Secreted annexins could therefore modulate Ca2+ influx. As maize annexins occur in the cytosol and plasma membrane, they were incorporated at the intracellular face of lipid bilayers designed to mimic the plasma membrane. Here, they generated an instantaneously activating Ca2+-permeable conductance at mildly acidic pH that was sensitive to verapamil and Gd3+ and had a Ca2+-to-K+ permeability ratio of 0.36. These results suggest that cytosolic annexins create a Ca2+ influx pathway directly, particularly during stress responses involving acidosis. A maize annexin preparation also demonstrated in vitro peroxidase activity that appeared independent of heme association. In conclusion, this study has demonstrated that plant annexins create Ca2+-permeable transport pathways, regulate [Ca2+]cyt, and may function as peroxidases in vitro. PMID:19234085

Control of IP3-mediated Ca2+ puffs in Xenopus laevis oocytes by the Ca2+-binding protein parvalbumin

PubMed Central

John, Linu M; Mosquera-Caro, Monica; Camacho, Patricia; Lechleiter, James D

2001-01-01

Elementary events of Ca2+ release (Ca2+ puffs) can be elicited from discrete clusters of inositol 1,4,5 trisphosphate receptors (IP3Rs) at low concentrations of IP3. Ca2+ puffs have rarely been observed unless elicited by either hormone treatment or introduction of IP3 into the cell. However, cells appear to have sufficient concentrations of IP3 (0.1-3.0 μM) to induce Ca2+ release under resting conditions. Here, we investigated Ca2+ puff activity in non-stimulated Xenopus oocytes using confocal microscopy. The fluorescent Ca2+ dye indicators Calcium Green 1 and Oregon Green 488 BAPTA-2 were injected into oocytes to monitor basal Ca2+ activity. In this preparation, injection or overexpression of parvalbumin, an EF-hand Ca2+-binding protein (CaBP), induced Ca2+ puffs in resting Xenopus oocytes. This activity was inhibited by heparin, an IP3R channel blocker, and by mutation of the Ca2+-binding sites in parvalbumin. Ca2+ puff activity was also evoked by injection of low concentrations of the Ca2+ chelator EGTA, but not by calbindin D28k, another member of the EF-hand CaBP superfamily. BAPTA and the Ca2+ indicator dye Oregon Green 488 BAPTA-1 evoked Ca2+ puff activity, while the dextran conjugate of Oregon Green 488 BAPTA-1 did not. These data indicate that a Ca2+ buffer must be mobile in order to increase Ca2+ puff activity. Together, the data indicate that some IP3Rs spontaneously release Ca2+ under resting concentrations of IP3. These elementary Ca2+ events appear to be below the level of detection of current imaging techniques. We suggest that parvalbumin evokes Ca2+ puffs by coordinating the activity of elementary IP3R channel openings. We conclude that Ca2+ release can be evoked not only by hormone-induced increases in IP3, but also by expression of mobile cytosolic CaBPs under resting concentrations of IP3. PMID:11507154

Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.

PubMed

Barclay, C J

2012-12-01

The aims of this study were to quantify the Ca(2+) release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca(2+) release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca(2+) release was quantified from the amount of ATP used to remove Ca(2+) from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca(2+) pump ATP turnover. At 20°C, Ca(2+) release in response to a single stimulus was 34 and 84 μmol (kg muscle)(-1) for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg(-1); EDL, 168 μmol kg(-1)). Delivery of another stimulus within 100 ms of the first produced a smaller Ca(2+) release. The maximum magnitude of the decrease in Ca(2+) release was greater in EDL than soleus. Ca(2+) release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca(2+) released and crossbridge cycles performed are consistent with a scheme in which Ca(2+) binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles.

Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles

PubMed Central

Barclay, C J

2012-01-01

The aims of this study were to quantify the Ca2+ release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca2+ release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca2+ release was quantified from the amount of ATP used to remove Ca2+ from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca2+ pump ATP turnover. At 20°C, Ca2+ release in response to a single stimulus was 34 and 84 μmol (kg muscle)−1 for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg−1; EDL, 168 μmol kg−1). Delivery of another stimulus within 100 ms of the first produced a smaller Ca2+ release. The maximum magnitude of the decrease in Ca2+ release was greater in EDL than soleus. Ca2+ release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca2+ released and crossbridge cycles performed are consistent with a scheme in which Ca2+ binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles. PMID:23027818

Bax regulates neuronal Ca2+ homeostasis.

PubMed

D'Orsi, Beatrice; Kilbride, Seán M; Chen, Gang; Perez Alvarez, Sergio; Bonner, Helena P; Pfeiffer, Shona; Plesnila, Nikolaus; Engel, Tobias; Henshall, David C; Düssmann, Heiko; Prehn, Jochen H M

2015-01-28

Excessive Ca(2+) entry during glutamate receptor overactivation ("excitotoxicity") induces acute or delayed neuronal death. We report here that deficiency in bax exerted broad neuroprotection against excitotoxic injury and oxygen/glucose deprivation in mouse neocortical neuron cultures and reduced infarct size, necrotic injury, and cerebral edema formation after middle cerebral artery occlusion in mice. Neuronal Ca(2+) and mitochondrial membrane potential (Δψm) analysis during excitotoxic injury revealed that bax-deficient neurons showed significantly reduced Ca(2+) transients during the NMDA excitation period and did not exhibit the deregulation of Δψm that was observed in their wild-type (WT) counterparts. Reintroduction of bax or a bax mutant incapable of proapoptotic oligomerization equally restored neuronal Ca(2+) dynamics during NMDA excitation, suggesting that Bax controlled Ca(2+) signaling independently of its role in apoptosis execution. Quantitative confocal imaging of intracellular ATP or mitochondrial Ca(2+) levels using FRET-based sensors indicated that the effects of bax deficiency on Ca(2+) handling were not due to enhanced cellular bioenergetics or increased Ca(2+) uptake into mitochondria. We also observed that mitochondria isolated from WT or bax-deficient cells similarly underwent Ca(2+)-induced permeability transition. However, when Ca(2+) uptake into the sarco/endoplasmic reticulum was blocked with the Ca(2+)-ATPase inhibitor thapsigargin, bax-deficient neurons showed strongly elevated cytosolic Ca(2+) levels during NMDA excitation, suggesting that the ability of Bax to support dynamic ER Ca(2+) handling is critical for cell death signaling during periods of neuronal overexcitation. Copyright © 2015 the authors 0270-6474/15/351706-17$15.00/0.

Role of different types of Ca2+ channels and a reticulum-like Ca2+ pump in neurotransmitter release.

PubMed

Fossier, P; Baux, G; Tauc, L

1993-01-01

The factors controlling the Ca2+ concentration directly responsible for triggering acetylcholine (ACh) release were investigated at an identified neuro-neuronal synapse of the Aplysia buccal ganglion. The types of presynaptic voltage-gated Ca2+ channels associated with transmitter release were determined by using selective blockers such as nifedipine, omega-conotoxin and a partially purified extract from the venom of a funnel web spider (FTx). L-type, N-type and P-type Ca2+ channels are present in the presynaptic neuron. The influx of Ca2+ through both N- and P-types induces the release of ACh whereas Ca2+ flowing through L-type channels modulates the duration of the presynaptic action potential by controlling the Ca(2+)-dependent K+ current. tBuBHQ, a blocker of the reticulum Ca2+ pump, induces a potentiation of evoked release without modifying the presynaptic Ca2+ influx. This seems to indicate that a part of the Ca2+ entering the presynaptic terminal through N- and P-type Ca2+ channels is sequestered in a presynaptic reticulum-like Ca2+ buffer preventing these ions from contributing to ACh release. To exert its control, this Ca2+ buffer must be located close to both the presynaptic Ca2+ channels and the transmitter release mechanism.

Structural basis for the differential effects of CaBP1 and calmodulin on Ca(V)1.2 calcium-dependent inactivation.

PubMed

Findeisen, Felix; Minor, Daniel L

2010-12-08

Calcium-binding protein 1 (CaBP1), a calmodulin (CaM) homolog, endows certain voltage-gated calcium channels (Ca(V)s) with unusual properties. CaBP1 inhibits Ca(V)1.2 calcium-dependent inactivation (CDI) and introduces calcium-dependent facilitation (CDF). Here, we show that the ability of CaBP1 to inhibit Ca(V)1.2 CDI and induce CDF arises from interaction between the CaBP1 N-lobe and interlobe linker residue Glu94. Unlike CaM, where functional EF hands are essential for channel modulation, CDI inhibition does not require functional CaBP1 EF hands. Furthermore, CaBP1-mediated CDF has different molecular requirements than CaM-mediated CDF. Overall, the data show that CaBP1 comprises two structural modules having separate functions: similar to CaM, the CaBP1 C-lobe serves as a high-affinity anchor that binds the Ca(V)1.2 IQ domain at a site that overlaps with the Ca²+/CaM C-lobe site, whereas the N-lobe/linker module houses the elements required for channel modulation. Discovery of this division provides the framework for understanding how CaBP1 regulates Ca(V)s. Copyright © 2010 Elsevier Ltd. All rights reserved.

Structural basis for the differential effects of CaBP1 and calmodulin on CaV1.2 calcium-dependent inactivation

PubMed Central

Findeisen, Felix; Minor, Daniel L.

2010-01-01

Calcium-binding protein 1 (CaBP1), a calmodulin (CaM) homolog, endows certain voltage-gated calcium channels (CaVs) with unusual properties. CaBP1 inhibits CaV1.2 calcium-dependent inactivation (CDI) and introduces calcium-dependent facilitation (CDF). Here, we show that the ability of CaBP1 to inhibit CaV1.2 CDI and induce CDF arises from interaction between the CaBP1 N-lobe and interlobe linker residue Glu94. Unlike CaM, where functional EF hands are essential for channel modulation, CDI inhibition does not require functional CaBP1 EF-hands. Furthermore, CaBP1-mediated CDF has different molecular requirements than CaM-mediated CDF. Overall, the data show that CaBP1 comprises two structural modules having separate functions: similar to CaM, the CaBP1 C-lobe serves as a high-affinity anchor that binds the CaV1.2 IQ domain at a site that overlaps with the Ca2+/CaM C-lobe site, whereas the N-lobe/linker module houses the elements required for channel modulation. Discovery of this division provides the framework for understanding how CaBP1 regulates CaVs. PMID:21134641

Na+ channel regulation by Ca2+/calmodulin and Ca2+/calmodulin-dependent protein kinase II in guinea-pig ventricular myocytes†

PubMed Central

Aiba, Takeshi; Hesketh, Geoffrey G.; Liu, Ting; Carlisle, Rachael; Villa-Abrille, Maria Celeste; O'Rourke, Brian; Akar, Fadi G.; Tomaselli, Gordon F.

2010-01-01

Aims Calmodulin (CaM) regulates Na+ channel gating through binding to an IQ-like motif in the C-terminus. Ca2+/CaM-dependent protein kinase II (CaMKII) regulates Ca2+ handling, and chronic overactivity of CaMKII is associated with left ventricular hypertrophy and dysfunction and lethal arrhythmias. However, the acute effects of Ca2+/CaM and CaMKII on cardiac Na+ channels are not fully understood. Methods and results Purified NaV1.5–glutathione-S-transferase fusion peptides were phosphorylated in vitro by CaMKII predominantly on the I–II linker. Whole-cell voltage-clamp was used to measure Na+ current (INa) in isolated guinea-pig ventricular myocytes in the absence or presence of CaM or CaMKII in the pipette solution. CaMKII shifted the voltage dependence of Na+ channel availability by ≈+5 mV, hastened recovery from inactivation, decreased entry into intermediate or slow inactivation, and increased persistent (late) current, but did not change INa decay. These CaMKII-induced changes of Na+ channel gating were completely abolished by a specific CaMKII inhibitor, autocamtide-2-related inhibitory peptide (AIP). Ca2+/CaM alone reproduced the CaMKII-induced changes of INa availability and the fraction of channels undergoing slow inactivation, but did not alter recovery from inactivation or the magnitude of the late current. Furthermore, the CaM-induced changes were also completely abolished by AIP. On the other hand, cAMP-dependent protein kinase A inhibitors did not abolish the CaM/CaMKII-induced alterations of INa function. Conclusion Ca2+/CaM and CaMKII have distinct effects on the inactivation phenotype of cardiac Na+ channels. The differences are consistent with CaM-independent effects of CaMKII on cardiac Na+ channel gating. PMID:19797425

Effects of long-term cryopreservation on peripheral blood progenitor cells.

PubMed

Vosganian, Gregory S; Waalen, Jill; Kim, Kevin; Jhatakia, Sejal; Schram, Ethan; Lee, Tracey; Riddell, Dan; Mason, James R

2012-11-01

The long-term stability of cryopreserved peripheral blood progenitor cells is an important issue for patients experiencing disease relapse. However, there is no consensus on how to evaluate the long-term effects of cryopreservation. We describe the effect of cryopreservation on viability and progenitor colony activity from 87 individual samples processed at the Scripps Green Hospital Stem Cell Processing Center (La Jolla, CA, USA). We randomly selected 87 peripheral blood hematopoietic stem cell (PBHSC) samples from 60 patients and evaluated the effect of cryopreservation on sample viability and red and white cell colony activity after < 24 h and 7, 10 and 15 years of cryopreservation. Viability was assayed via trypan blue dye exclusion and activity was measured following 14 days of culture. An age at collection older than 50 years may result in suboptimal activity and viability following long-term cryopreservation, while gender and disease status had no effect. Cryopreservation did not significantly affect white or red cell activity following 10 years of cryopreservation. However, for samples stored longer than 10 years, viability and activity significantly decreased. We noted a positive association between higher pre-cryopreservation %CD34 count and colony activity. Cryopreservation of peripheral blood progenitor cells for up to 10 years results in no loss of clonogenic capacity, as determined by culture activity, although longer durations of storage may affect activity. Until validated methods are developed, cryopreserved grafts should be evaluated based on pre-freeze CD34(+) cell counts as assayed by flow cytometry, and post-thaw sample evaluation should be reserved for patients identified as poor mobilizers.

An Aqueous Ca-Ion Battery

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

Gheytani, Saman; Liang, Yanliang; Wu, Feilong

Multivalent-ion batteries are emerging as low-cost, high energy density, and safe alternatives to Li-ion batteries but are challenged by slow cation diffusion in electrode materials due to the high polarization strength of Mg- and Al-ions. In contrast, Ca-ion has a low polarization strength similar to that of Li-ion, therefore a Ca-ion battery will share the advantages while avoiding the kinetics issues related to multivalent batteries. However, there is no battery known that utilizes the Ca-ion chemistry due to the limited success in Ca-ion storage materials. Here, a safe and low-cost aqueous Ca-ion battery based on a highly reversible polyimide anodemore » and a high-potential open framework copper hexacyanoferrate cathode is demonstrated. The prototype cell shows a stable capacity and high efficiency at both high and low current rates, with an 88% capacity retention and an average 99% coloumbic efficiency after cycling at 10C for 1000 cycles. The Ca-ion storage mechanism for both electrodes as well as the origin of the fast kinetics have been investigated. Finally, additional comparison with a Mg-ion cell with identical electrodes reveals clear kinetics advantages for the Ca-ion system, which is explained by the smaller ionic radii and more facile desolvation of hydrated Ca-ions.« less

An Aqueous Ca-Ion Battery

DOE PAGES

Gheytani, Saman; Liang, Yanliang; Wu, Feilong; ...

2017-10-26

Multivalent-ion batteries are emerging as low-cost, high energy density, and safe alternatives to Li-ion batteries but are challenged by slow cation diffusion in electrode materials due to the high polarization strength of Mg- and Al-ions. In contrast, Ca-ion has a low polarization strength similar to that of Li-ion, therefore a Ca-ion battery will share the advantages while avoiding the kinetics issues related to multivalent batteries. However, there is no battery known that utilizes the Ca-ion chemistry due to the limited success in Ca-ion storage materials. Here, a safe and low-cost aqueous Ca-ion battery based on a highly reversible polyimide anodemore » and a high-potential open framework copper hexacyanoferrate cathode is demonstrated. The prototype cell shows a stable capacity and high efficiency at both high and low current rates, with an 88% capacity retention and an average 99% coloumbic efficiency after cycling at 10C for 1000 cycles. The Ca-ion storage mechanism for both electrodes as well as the origin of the fast kinetics have been investigated. Finally, additional comparison with a Mg-ion cell with identical electrodes reveals clear kinetics advantages for the Ca-ion system, which is explained by the smaller ionic radii and more facile desolvation of hydrated Ca-ions.« less

Akt activation by Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) in ovarian cancer cells.

PubMed

Gocher, Angela M; Azabdaftari, Gissou; Euscher, Lindsey M; Dai, Shuhang; Karacosta, Loukia G; Franke, Thomas F; Edelman, Arthur M

2017-08-25

Hyperactivation of Akt is associated with oncogenic changes in the growth, survival, and chemoresistance of cancer cells. The PI3K/phosphoinositide-dependent kinase (PDK) 1 pathway represents the canonical mechanism for phosphorylation of Akt at its primary activation site, Thr-308. We observed that Ca 2+ /calmodulin (CaM)-dependent protein kinase kinase 2 (β) (CaMKK2) is highly expressed in high-grade serous ovarian cancer, and we investigated its role in Akt activation in ovarian cancer (OVCa) cell lines (OVCAR-3, SKOV-3, and Caov-3). Knockdown or pharmacological inhibition of CaMKK2 produced phenotypes expected of Akt inhibition, including reductions in cell growth and cell viability and in the regulation of Akt downstream targets involved in G 1 /S transition and apoptosis. CaMKK2 knockdown or inhibition decreased Akt phosphorylation at Thr-308 and Ser-473 to extents similar to those of PDK1 knockdown or PI3K inhibition. Combined CaMKK2 and PDK1 knockdown or CaMKK and PI3K inhibition, respectively, produced additive effects on p-Akt and cell growth, consistent with direct Akt phosphorylation by CaMKK2. This conclusion was supported by the absence of effects of CaMKK2 knockdown/inhibition on alternative means of activating Akt via p-Akt Thr-450, p-PDK1 Ser-241, or p-IRS1 Ser-636/639. Recombinant CaMKK2 directly activated recombinant Akt by phosphorylation at Thr-308 in a Ca 2+ /CaM-dependent manner. In OVCa cells, p-Akt Thr-308 was significantly inhibited by intracellular Ca 2+ i chelation or CaM inhibition. Ionomycin-induced Ca 2+ influx promoted p-Akt, an effect blocked by PDK1, and/or CaMKK2, siRNAs, and by PI3K and/or CaMKK inhibitors. CaMKK2 knockdown potentiated the effects of the chemotherapeutic drugs carboplatin and PX-866 to reduce proliferation and survival of OVCa cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Final report on International Conference on Radiationless Transitions Held at Newport Beach, California on January 3-7, 1984.

DTIC Science & Technology

1984-12-31

Ca. 90007 USA Eric C. Apel Dr. G. Comtet Department of Chemstry Department of Chemistry University of CAlifornia University of Californiai Irvine...Chicago Tempo, Az 85827 USA Chicago, Ill. 60637 USA - Professor R. Kopelman Professor S’. H. Lin Department of Chemistry Department of Chemstry . University...Nadler Department of Chemstry Ms. B. Lawrence University of Southern Calif. Department of Chemistry Los Angeles, Ca. 90007 USA University of California

Apocalmodulin and Ca2+ calmodulin bind to the same region on the skeletal muscle Ca2+ release channel

NASA Technical Reports Server (NTRS)

Moore, C. P.; Rodney, G.; Zhang, J. Z.; Santacruz-Toloza, L.; Strasburg, G.; Hamilton, S. L.

1999-01-01

The skeletal muscle Ca2+ release channel (RYR1) is regulated by calmodulin in both its Ca2+-free (apocalmodulin) and Ca2+-bound (Ca2+ calmodulin) states. Apocalmodulin is an activator of the channel, and Ca2+ calmodulin is an inhibitor of the channel. Both apocalmodulin and Ca2+ calmodulin binding sites on RYR1 are destroyed by a mild tryptic digestion of the sarcoplasmic reticulum membranes, but calmodulin (either form), bound to RYR1 prior to tryptic digestion, protects both the apocalmodulin and Ca2+ calmodulin sites from tryptic destruction. The protected sites are after arginines 3630 and 3637 on RYR1. These studies suggest that both Ca2+ calmodulin and apocalmodulin bind to the same or overlapping regions on RYR1 and block access of trypsin to sites at amino acids 3630 and 3637. This sequence is part of a predicted Ca2+ CaM binding site of amino acids 3614-3642 [Takeshima, H., et al. (1989) Nature 339, 439-445].

Physical conditions in CaFe interstellar clouds

NASA Astrophysics Data System (ADS)

Gnaciński, P.; Krogulec, M.

2008-01-01

Interstellar clouds that exhibit strong Ca I and Fe I lines are called CaFe clouds. Ionisation equilibrium equations were used to model the column densities of Ca II, Ca I, K I, Na I, Fe I and Ti II in CaFe clouds. We find that the chemical composition of CaFe clouds is solar and that there is no depletion into dust grains. CaFe clouds have high electron densities, n_e≈1 cm-3, that lead to high column densities of neutral Ca and Fe.

Ca 3d unoccupied states in Bi2Sr2CaCu2O8 investigated by Ca L2,3 x-ray-absorption near-edge structure

NASA Astrophysics Data System (ADS)

Borg, A.; King, P. L.; Pianetta, P.; Lindau, I.; Mitzi, D. B.; Kapitulnik, A.; Soldatov, A. V.; della Longa, S.; Bianconi, A.

1992-10-01

The high-resolution Ca L2,3 x-ray-absorption near-edge-structure (XANES) spectrum of a Bi2Sr2CaCu2O8 single crystal has been measured by use of a magnetic-projection x-ray microscope probing a surface area of 200×200 μm2. The Ca L2,3 XANES spectrum is analyzed by performing a multiple-scattering XANES calculation in real space and comparing the results with the spectrum of CaF2. Good agreement between the calculated and experimental crystal-field splitting Δf of the Ca 3d final states is found and the splitting is shown to be smaller by 0.5 eV than in the initial state. The Ca 3d partial density of states is found to be close to the Fermi level in the initial state. The Ca-O(in plane) distance is shown to be a critical parameter associated with the shift of the Ca 3d states relative to the Fermi level; in particular, we have studied the effect of the out-of-plane dimpling mode of the in-plane oxygen atoms O(in plane) that will move the Ca 3d states on or off the Fermi level. This mode can therefore play a role in modulating the charge transfer between the two CuO2 planes separated by the Ca ions.

The effects of a whole-watershed calcium addition on the chemistry of stream storm events at the Hubbard Brook Experimental Forest in NH, USA.

PubMed

Cho, Youngil; Driscoll, Charles T; Blum, Joel D

2009-10-01

Patterns of storm runoff chemistry from a wollastonite (calcium-silicate mineral, CaSiO(3)) treated watershed (W1) were compared with a reference watershed (W6) at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire (NH), USA to investigate the role of Ca(2+) supply in the acid-base status of stream chemistry. In the summer of 2003, six storm events were studied in W1 and W6 to evaluate the effects of the wollastonite treatment on the episodic acidification of stream waters. Although mean values of Ca(2+) concentrations decreased slightly from 33.8 to 31.7 mumol/L with increasing stream discharge in W1 during the events, the mean value of acid neutralizing capacity (ANC) was positive (1.2 mueq/L) during storm events, compared to negative values (-0.2 mueq/L) in W6. This pattern is presumably due to enhanced Ca(2+) supply in W1 (20.7 to 29.0% of dissolved Ca(2+) derived from the added wollastonite) to stream water as a result of interflow along shallow flowpaths. In addition, the application of wollastonite increased pH and dissolved silica (H(4)SiO(4)) concentrations, and decreased the concentration of inorganic monomeric Al (Al(i)) in W1 in comparison with W6 during storm events. Despite an increase in SO(4)(2-) concentration, likely due to desorption of sulfate from soil after the treatment, the watershed showed an increase in ANC compared to the reference watershed, serving to mitigate episodic acidification.

Down-regulation of CaV1.2 channels during hypertension: how fewer CaV1.2 channels allow more Ca2+ into hypertensive arterial smooth muscle

PubMed Central

Tajada, Sendoa; Cidad, Pilar; Colinas, Olaia; Santana, L Fernando; López-López, José R; Pérez-García, M Teresa

2013-01-01

Hypertension is a clinical syndrome characterized by increased arterial tone. Although the mechanisms are varied, the generally accepted view is that increased CaV1.2 channel function is a common feature of this pathological condition. Here, we investigated the mechanisms underlying vascular dysfunction in a mouse model of genetic hypertension. Contrary to expectation, we found that whole-cell CaV1.2 currents (ICa) were lower in hypertensive (BPH line) than normotensive (BPN line) myocytes. However, local CaV1.2 sparklet activity was higher in BPH cells, suggesting that the relatively low ICa in these cells was produced by a few hyperactive CaV1.2 channels. Furthermore, our data suggest that while the lower expression of the pore-forming α1c subunit of CaV1.2 currents underlies the lower ICa in BPH myocytes, the increased sparklet activity was due to a different composition in the auxiliary subunits of the CaV1.2 complexes. ICa currents in BPN cells were produced by channels composed of α1c/α2δ/β3 subunits, while in BPH myocytes currents were probably generated by the opening of channels formed by α1c/α2δ/β2 subunits. In addition, Ca2+ sparks evoked large conductance, Ca2+-activated K+ (BK) currents of lower magnitude in BPH than in BPN myocytes, because BK channels were less sensitive to Ca2+. Our data are consistent with a model in which a decrease in the global number of CaV1.2 currents coexist with the existence of a subpopulation of highly active channels that dominate the resting Ca2+ influx. The decrease in BK channel activity makes the hyperpolarizing brake ineffective and leads BPH myocytes to a more contracted resting state. PMID:24167226

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

Attendees of the USA Science and Engineering Festival observe their infrared images as a NASA Staff member describes the James Webb Space Telescope. It will be a large infrared telescope with a 6.5 meter primary mirror and will study every phase in the history of our Universe ranging from the Big Bang to the formation of our Solar System. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Optical magnetoelectric effect at CaRuO3-CaMnO3 interfaces as a polar ferromagnet

NASA Astrophysics Data System (ADS)

Yamada, Hiroyuki; Sato, H.; Akoh, H.; Kida, N.; Arima, T.; Kawasaki, M.; Tokura, Y.

2008-02-01

A correlated electron interface between paramagnetic CaRuO3 and antiferromagnetic CaMnO3 has been characterized with optical magnetoelectric (OME) effect as an interface-selective probe for spin and charge states. To detect the OME effect, i.e., nonreciprocal directional dichroism for visible or near-infrared light, we have constructed a "tricolor" superlattice with artificially broken inversion symmetry by stacking CaRuO3, CaMnO3, and CaTiO3, and patterned a grating structure with 4μm period on the superlattice. The observed intensity modulation (0.3% at 50K) in the Bragg diffraction verifies a charge transfer and concomitant ferromagnetism at the CaRuO3-CaMnO3 interface.

Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models

NASA Astrophysics Data System (ADS)

Mejía, Luz María; Paytan, Adina; Eisenhauer, Anton; Böhm, Florian; Kolevica, Ana; Bolton, Clara; Méndez-Vicente, Ana; Abrevaya, Lorena; Isensee, Kirsten; Stoll, Heather

2018-01-01

Coccoliths comprise a major fraction of the global carbonate sink. Therefore, changes in coccolithophores' Ca isotopic fractionation could affect seawater Ca isotopic composition, affecting interpretations of the global Ca cycle and related changes in seawater chemistry and climate. Despite this, a quantitative interpretation of coccolith Ca isotopic fractionation and a clear understanding of the mechanisms driving it are not yet available. Here, we address this gap in knowledge by developing a simple model (CaSri-Co) to track coccolith Ca isotopic fractionation during cellular Ca uptake and allocation to calcification. We then apply it to published and new δ 44 / 40 Ca and Sr/Ca data of cultured coccolithophores of the species Emiliania huxleyi and Gephyrocapsa oceanica. We identify changes in calcification rates, Ca retention efficiency and solvation-desolvation rates as major drivers of the Ca isotopic fractionation and Sr/Ca variations observed in cultures. Higher calcification rates, higher Ca retention efficiencies and lower solvation-desolvation rates increase both coccolith Ca isotopic fractionation and Sr/Ca. Coccolith Ca isotopic fractionation is most sensitive to changes in solvation-desolvation rates. Changes in Ca retention efficiency may be a major driver of coccolith Sr/Ca variations in cultures. We suggest that substantial changes in the water structure strength caused by past changes in temperature could have induced significant changes in coccolithophores' Ca isotopic fractionation, potentially having some influence on seawater Ca isotopic composition. We also suggest a potential effect on Ca isotopic fractionation via modification of the solvation environment through cellular exudates, a hypothesis that remains to be tested.

Mutation Induced Conformational Change In CaMKII Peptide Alters Binding Affinity to CaM Through Alternate Binding Site

NASA Astrophysics Data System (ADS)

Ezerski, Jacob; Cheung, Margaret

CaM forms distinct conformation states through modifications in its charge distribution upon binding to Ca2+ ions. The occurrence of protein structural change resulting from an altered charge distribution is paramount in the scheme of cellular signaling. Not only is charge induced structural change observed in CaM, it is also seen in an essential binding target: calmodulin-depended protein kinase II (CaMKII). In order to investigate the mechanism of selectivity in relation to changes in secondary structure, the CaM binding domain of CaMKII is isolated. Experimentally, charged residues of the CaMKII peptide are systematically mutated to alanine, resulting in altered binding kinetics between the peptide and the Ca2+ saturated state of CaM. We perform an all atom simulation of the wildtype (RRK) and mutated (AAA) CaMKII peptides and generate structures from the trajectory. We analyze RRK and AAA using DSSP and find significant structural differences due to the mutation. Structures from the RRK and AAA ensembles are then selected and docked onto the crystal structure of Ca2+ saturated CaM. We observe that RRK binds to CaM at the C-terminus, whereas the 3-residue mutation, AAA, shows increased patterns of binding to the N-terminus and linker regions of CaM. Due to the conformational change of the peptide ensemble from charged residue mutation, a distinct change in the binding site can be seen, which offers an explanation to experimentally observed changes in kinetic binding rates

Interfacial Ferromagnetism and Exchange Bias in CaRuO3/CaMnO3 Superlattices

DTIC Science & Technology

2012-11-07

microscopy and electron energy loss spectroscopy indicate that the difference in magnitude of the Mn valence states between the center of the CaMnO3 layer...CaMnO3 thickness dependence of the exchange bias field together indicate that the interfacial 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13...superlattices of CaRuO3/CaMnO3 that arises in one unit cell at the interface. Scanning transmission electron microscopy and electron energy loss

Presynaptic kainate receptor-mediated facilitation of glutamate release involves Ca2+ -calmodulin at mossy fiber-CA3 synapses.

PubMed

Andrade-Talavera, Yuniesky; Duque-Feria, Paloma; Negrete-Díaz, José Vicente; Sihra, Talvinder S; Flores, Gonzalo; Rodríguez-Moreno, Antonio

2012-09-01

Presynaptic kainate receptors (KARs) modulate the release of glutamate at synapses established between mossy fibers (MF) and CA3 pyramidal cells in the hippocampus. The activation of KAR by low, nanomolar, kainate concentrations facilitates glutamate release. KAR-mediated facilitation of glutamate release involves the activation of an adenylate cyclase/cyclic adenosine monophosphate/protein kinase A cascade at MF-CA3 synapses. Here, we studied the mechanisms by which KAR activation produces this facilitation of glutamate release in slices and synaptosomes. We find that the facilitation of glutamate release mediated by KAR activation requires an increase in Ca(2+) levels in the cytosol and the formation of a Ca(2+) -calmodulin complex to activate adenylate cyclase. The increase in cytosolic Ca(2+) underpinning this modulation is achieved, both, by Ca(2+) entering via Ca(2+) -permeable KARs and, by the mobilization of intraterminal Ca(2+) stores. Finally, we find that, congruent with the Ca(2+) -calmodulin support of KAR-mediated facilitation of glutamate release, induction of long-term potentiation at MF-CA3 synapses has an obligate requirement for Ca(2+) -calmodulin activity. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Modulation of Ca(v)3.1 T-type Ca2+ channels by the ran binding protein RanBPM.

PubMed

Kim, Taehyun; Kim, Sunoh; Yun, Hyung-Mun; Chung, Kwang Chul; Han, Ye Sun; Shin, Hee-Sup; Rhim, Hyewhon

2009-01-02

In order to study the currently unknown cellular signaling pathways of Ca(v)3.1 T-type Ca(2+) channels (Ca(v)3.1 channels), we performed a yeast two-hybrid screening using intracellular domains of Ca(v)3.1 alpha1 subunit as bait. After screening the human brain cDNA library, several proteins, including RanBPM, were identified as interacting with Ca(v)3.1 channels. RanBPM was found to bind to the cytoplasmic intracellular loop between transmembrane domains I and II of Ca(v)3.1 channels. Using whole-cell patch-clamp techniques, we found that Ca(v)3.1 currents were increased by the expression of RanBPM in HEK293/Ca(v)3.1 cells. We next examined whether RanBPM affected the biophysical properties and plasma membrane expression of Ca(v)3.1 channels. Furthermore, we showed that the PKC activator inhibited Ca(v)3.1 currents, an effect that was abolished by the expression of RanBPM. These results suggest that RanBPM could be a key regulator of Ca(v)3.1 channel-mediated signaling pathways.

Simultaneous Ka-Band Site Characterization: Goldstone, CA, White Sands, NM, and Guam, USA

NASA Technical Reports Server (NTRS)

Acosta, Roberto; Morse, Jacquelynne; Zemba, Michael; Nessel, James; Morabito, David; Caroglanian, Armen

2011-01-01

To statistically characterize atmospheric effects on Ka-band links at NASA operational sites, NASA has constructed site test interferometers (STI s) which directly measure the tropospheric phase stability and rain attenuation. These instruments observe an unmodulated beacon signal broadcast from a geostationary satellite (e.g., Anik F2) and measure the phase difference between the signals received by the two antennas and its signal attenuation. Three STI s have been deployed so far: the first one at the NASA Deep Space Network Tracking Complex in Goldstone, California (May 2007); the second at the NASA White Sands Complex, in Las Cruses, New Mexico (February 2009); and the third at the NASA Tracking and Data Relay Satellite (TDRS) Remote Ground Terminal (GRGT) complex in Guam (May 2010). Two station-years of simultaneous atmospheric phase fluctuation data have been collected at Goldstone and White Sands, while one year of data has been collected in Guam. With identical instruments operating simultaneously, we can directly compare the phase stability and rain attenuation at the three sites. Phase stability is analyzed statistically in terms of the root-mean-square (rms) of the tropospheric induced time delay fluctuations over 10 minute blocks. For two years, the time delay fluctuations at the DSN site in Goldstone, CA, have been better than 2.5 picoseconds (ps) for 90% of the time (with reference to zenith), meanwhile at the White Sands, New Mexico site, the time delay fluctuations have been better than 2.2 ps with reference to zenith) for 90% of time. For Guam, the time delay fluctuations have been better than 12 ps (reference to zenith) at 90% of the time, the higher fluctuations are as expected from a high humidity tropical rain zone. This type of data analysis, as well as many other site quality characteristics (e.g., rain attenuation, infrastructure, etc.) will be used to determine the suitability of all the sites for NASA s future communication services at Ka-band.

Far-infrared and dc magnetotransport of CaMnO3-CaRuO3 superlattices

NASA Astrophysics Data System (ADS)

Yordanov, P.; Boris, A. V.; Freeland, J. W.; Kavich, J. J.; Chakhalian, J.; Lee, H. N.; Keimer, B.

2011-07-01

We report temperature- and magnetic-field-dependent measurements of the dc resistivity and the far-infrared reflectivity (FIR) (photon energies ℏω=50-700 cm-1) of superlattices comprising ten consecutive unit cells of the antiferromagnetic insulator CaMnO3, and four to ten unit cells of the correlated paramagnetic metal CaRuO3. Below the Néel temperature of CaMnO3, the dc resistivity exhibits a logarithmic divergence upon cooling, which is associated with a large negative, isotropic magnetoresistance. The ω→0 extrapolation of the resistivity extracted from the FIR reflectivity, on the other hand, shows a much weaker temperature and field dependence. We attribute this behavior to scattering of itinerant charge carriers in CaRuO3 from sparse, spatially isolated magnetic defects at the CaMnO3-CaRuO3 interfaces. This field-tunable “transport bottleneck” effect may prove useful for functional metal-oxide devices.

Synthesis of Al₂Ca Dispersoids by Powder Metallurgy Using a Mg-Al Alloy and CaO Particles.

PubMed

Fujita, Junji; Umeda, Junko; Kondoh, Katsuyoshi

2017-06-28

The elemental mixture of Mg-6 wt %Al-1 wt %Zn-0.3 wt %Mn (AZ61B) alloy powder and CaO particles was consolidated by an equal-channel angular bulk mechanical alloying (ECABMA) process to form a composite precursor. Subsequently, the precursor was subjected to a heat treatment to synthesize fine Al₂Ca particles via a solid-state reaction between the Mg-Al matrix and CaO additives. Scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and electron probe micro-analysis on the precursor indicated that 4.7-at % Al atoms formed a supersaturated solid solution in the α-Mg matrix. Transmission electron microscopy-EDS and X-ray diffraction analyses on the AZ61B composite precursor with 10-vol % CaO particles obtained by heat treatment confirmed that CaO additives were thermally decomposed in the Mg-Al alloy, and the solid-soluted Ca atoms diffused along the α-Mg grain boundaries. Al atoms also diffused to the grain boundaries because of attraction to the Ca atoms resulting from a strong reactivity between Al and Ca. As a result, needle-like (Mg,Al)₂Ca intermetallics were formed as intermediate precipitates in the initial reaction stage during the heat treatment. Finally, the precipitates were transformed into spherical Al₂Ca particles by the substitution of Al atoms for Mg atoms in (Mg,Al)₂Ca after a long heat treatment.

The Ca2+ leak paradox and “rogue ryanodine receptors”: SR Ca2+ efflux theory and practice

PubMed Central

Sobie, Eric A.; Guatimosim, Silvia; Gómez-Viquez, Leticia; Song, Long-Sheng; Hartmann, Hali; Jafri, M. Saleet; Lederer, W.J.

2006-01-01

Ca2+ efflux from the sarcoplasmic reticulum (SR) is routed primarily through SR Ca2+ release channels (ryanodine receptors, RyRs). When clusters of RyRs are activated by trigger Ca2+ influx through L-type Ca2+ channels (dihydropyridine receptors, DHPR), Ca2+ sparks are observed. Close spatial coupling between DHPRs and RyR clusters and the relative insensitivity of RyRs to be triggered by Ca2+ together ensure the stability of this positive-feedback system of Ca2+ amplification. Despite evidence from single channel RyR gating experiments that phosphorylation of RyRs by protein kinase A (PKA) or calcium-calmodulin dependent protein kinase II (CAMK II) causes an increase in the sensitivity of the RyR to be triggered by [Ca2+]i there is little clear evidence to date showing an increase in Ca2+ spark rate. Indeed, there is some evidence that the SR Ca2+ content may be decreased in hyperadrenergic disease states. The question is whether or not these observations are compatible with each other and with the development of arrhythmogenic extrasystoles that can occur under these conditions. Furthermore, the appearance of an increase in the SR Ca2+ “leak” under these conditions is perplexing. These and related complexities are analyzed and discussed in this report. Using simple mathematical modeling discussed in the context of recent experimental findings, a possible resolution to this paradox is proposed. The resolution depends upon two features of SR function that have not been confirmed directly but are broadly consistent with several lines of indirect evidence: (1) the existence of unclustered or “rogue” RyRs that may respond differently to local [Ca2+]i in diastole and during the [Ca2+]i transient; and (2) a decrease in cooperative or coupled gating between clustered RyRs in response to physiologic phosphorylation or hyperphosphorylation of RyRs in disease states such as heart failure. Taken together, these two features may provide a framework that allows for an

Airborne surveys of USA urban areas at 121.5/243 MHz

NASA Technical Reports Server (NTRS)

Taylor, R. E.; Hill, J. S.

1979-01-01

In situ, aircraft flight measurements were made in 1976 and 1977 by NASA of the radio-frequency environment over USA urban areas within the emergency distress search and rescue frequency bands at 121.5 and 243.0 MHz. This paper analyzes test results reported previously for USA East Coast and Midwest flight surveys; presented also are test results obtained in May 1977 for the USA West Coast during the NASA, ASSESS-II, Space Shuttle/Spacelab simulation aircraft flights. The USA West Coast flight include data at 121.5/243 MHz during an extensive series of aircraft passes for the Los Angeles urban area. The USA East Coast/Midwest measurements show correlation with population count.

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival observes the infrared image of himself as a NASA staff member describes the James Webb Space Telescope. It will be a large infrared telescope with a 6.5 meter primary mirror and will study every phase in the history of our Universe ranging from the Big Bang to the formation of our Solar System. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival examines how glass blocks some heat, altering the infrared image of himself. The James Webb Space Telescope will be a large infrared telescope with a 6.5 meter primary mirror and will study every phase in the history of our Universe ranging from the Big Bang to the formation of our Solar System. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival observes the infrared image of himself as a NASA Staff member describes the James Webb Space Telescope. It will be a large infrared telescope with a 6.5 meter primary mirror and will study every phase in the history of our Universe ranging from the Big Bang to the formation of our Solar System. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival observes Robonaut 2 at the NASA Stage. Robonaut 2 is NASA's first dexterous humanoid robot that has been working on the International Space Station for the last three years. R2 recently received 1.2 meter long legs to allow mobility. This will enable R2 to assist more with regular and repetitive tasks inside and outside the station. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Ca2+-induced delayed afterdepolarizations are triggered by dyadic subspace Ca2+ affirming that increasing SERCA reduces aftercontractions

PubMed Central

Noble, Penelope J.; Noble, Denis

2011-01-01

Ca2+-induced delayed afterdepolarizations (DADs) are depolarizations that occur after full repolarization. They have been observed across multiple species and cell types. Experimental results have indicated that the main cause of DADs is Ca2+ overload. The main hypothesis as to their initiation has been Ca2+ overflow from the overloaded sarcoplasmic reticulum (SR). Our results using 37 previously published mathematical models provide evidence that Ca2+-induced DADs are initiated by the same mechanism as Ca2+-induced Ca2+ release, i.e., the modulation of the opening of ryanodine receptors (RyR) by Ca2+ in the dyadic subspace; an SR overflow mechanism was not necessary for the induction of DADs in any of the models. The SR Ca2+ level is better viewed as a modulator of the appearance of DADs and the magnitude of Ca2+ release. The threshold for the total Ca2+ level within the cell (not only the SR) at which Ca2+ oscillations arise in the models is close to their baseline level (∼1- to 3-fold). It is most sensitive to changes in the maximum sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pump rate (directly proportional), the opening probability of RyRs, and the Ca2+ diffusion rate from the dyadic subspace into the cytosol (both indirectly proportional), indicating that the appearance of DADs is multifactorial. This shift in emphasis away from SR overload as the trigger for DADs toward a multifactorial analysis could explain why SERCA overexpression has been shown to suppress DADs (while increasing contractility) and why DADs appear during heart failure (at low SR Ca2+ levels). PMID:21666112

Structural and compositional characterization of synthetic (Ca,Sr)-tremolite and (Ca,Sr)-diopside solid solutions

NASA Astrophysics Data System (ADS)

Gottschalk, M.; Najorka, J.; Andrut, M.

Tremolite (CaxSr1-x)2Mg5[Si8O22/(OH)2] and diopside (CaxSr1-x)Mg[Si2O6] solid solutions have been synthesized hydrothermally in equilibrium with a 1 molar (Ca,Sr)Cl2 aqueous solution at 750°C and 200 MPa. The solid run products have been investigated by optical, electron scanning and high resolution transmission electron microscopy, electron microprobe, X-ray-powder diffraction and Fourier-transform infrared spectroscopy. The synthesized (Ca,Sr)-tremolites are up to 2000 µm long and 30 µm wide, the (Ca,Sr)-diopsides are up to 150 µm long and 20 µm wide. In most runs the tremolites and diopsides are well ordered and chain multiplicity faults are rare. Nearly pure Sr-tremolite (tr0.02Sr-tr0.98) and Sr-diopside (di0.01Sr-di0.99) have been synthesized. A continuous solid solution series, i.e. complete substitution of Sr2+ for Ca2+ on M4-sites exists for (Ca,Sr)-tremolite. Total substitution of Sr2+ for Ca2+ on M2-sites can be assumed for (Ca,Sr)-diopsides. For (Ca,Sr)-tremolites the lattice parameters a, b and β are linear functions of composition and increase with Sr-content whereas c is constant. For the diopside series all 4 lattice parameters are a linear function of composition; a, b, c increase and β decreases with rising Sr-content. The unit cell volume for tremolite increases 3.47% from 906.68 Å3 for tremolite to 938.21 Å3 for Sr-tremolite. For diopside the unit cell volume increases 4.87 % from 439.91 Å3 for diopside to 461.30 Å3 for Sr-diopside. The observed splitting of the OH stretching band in tremolite is caused by different configurations of the next nearest neighbors (multi mode behavior). Resolved single bands can be attributed to the following configurations on the M4-sites: SrSr, SrCa, CaCa and CaMg. The peak positions of these 4 absorption bands are a linear function of composition. They are shifted to lower wavenumbers with increasing Sr-content. No absorption band due to the SrMg configuration on the M4-site is observed. This indicates

Synaptically activated Ca2+ waves and NMDA spikes locally suppress voltage-dependent Ca2+ signalling in rat pyramidal cell dendrites

PubMed Central

Manita, Satoshi; Miyazaki, Kenichi; Ross, William N

2011-01-01

Abstract Postsynaptic [Ca2+]i changes contribute to several kinds of plasticity in pyramidal neurons. We examined the effects of synaptically activated Ca2+ waves and NMDA spikes on subsequent Ca2+ signalling in CA1 pyramidal cell dendrites in hippocampal slices. Tetanic synaptic stimulation evoked a localized Ca2+ wave in the primary apical dendrites. The [Ca2+]i increase from a backpropagating action potential (bAP) or subthreshold depolarization was reduced if it was generated immediately after the wave. The suppression had a recovery time of 30–60 s. The suppression only occurred where the wave was generated and was not due to a change in bAP amplitude or shape. The suppression also could be generated by Ca2+ waves evoked by uncaging IP3, showing that other signalling pathways activated by the synaptic tetanus were not required. The suppression was proportional to the amplitude of the [Ca2+]i change of the Ca2+ wave and was not blocked by a spectrum of kinase or phosphatase inhibitors, consistent with suppression due to Ca2+-dependent inactivation of Ca2+ channels. The waves also reduced the frequency and amplitude of spontaneous, localized Ca2+ release events in the dendrites by a different mechanism, probably by depleting the stores at the site of wave generation. The same synaptic tetanus often evoked NMDA spike-mediated [Ca2+]i increases in the oblique dendrites where Ca2+ waves do not propagate. These NMDA spikes suppressed the [Ca2+]i increase caused by bAPs in those regions. [Ca2+]i increases by Ca2+ entry through voltage-gated Ca2+ channels also suppressed the [Ca2+]i increases from subsequent bAPs in regions where the voltage-gated [Ca2+]i increases were largest, showing that all ways of raising [Ca2+]i could cause suppression. PMID:21844002

Formation of CaB6 in the thermal decomposition of the hydrogen storage material Ca(BH4)2.

PubMed

Sahle, Christoph J; Sternemann, Christian; Giacobbe, Carlotta; Yan, Yigang; Weis, Christopher; Harder, Manuel; Forov, Yury; Spiekermann, Georg; Tolan, Metin; Krisch, Michael; Remhof, Arndt

2016-07-20

Using a combination of high resolution X-ray powder diffraction and X-ray Raman scattering spectroscopy at the B K- and Ca L2,3-edges, we analyzed the reaction products of Ca(BH4)2 after annealing at 350 °C and 400 °C under vacuum conditions. We observed the formation of nanocrystalline/amorphous CaB6 mainly and found only small contributions from amorphous B for annealing times larger than 2 h. For short annealing times of 0.5 h at 400 °C we observed neither CaB12H12 nor CaB6. The results indicate a reaction pathway in which Ca(BH4)2 decomposes to B and CaH2 and finally reacts to form CaB6. These findings confirm the potential of using Ca(BH4)2 as a hydrogen storage medium and imply the desired cycling capabilities for achieving high-density hydrogen storage materials.

Ca2+/Calmodulin-Dependent Protein Kinase Kinases (CaMKKs) Effects on AMP-Activated Protein Kinase (AMPK) Regulation of Chicken Sperm Functions.

PubMed

Nguyen, Thi Mong Diep; Combarnous, Yves; Praud, Christophe; Duittoz, Anne; Blesbois, Elisabeth

2016-01-01

Sperm require high levels of energy to ensure motility and acrosome reaction (AR) accomplishment. The AMP-activated protein kinase (AMPK) has been demonstrated to be strongly involved in the control of these properties. We address here the question of the potential role of calcium mobilization on AMPK activation and function in chicken sperm through the Ca(2+)/calmodulin-dependent protein kinase kinases (CaMKKs) mediated pathway. The presence of CaMKKs and their substrates CaMKI and CaMKIV was evaluated by western-blotting and indirect immunofluorescence. Sperm were incubated in presence or absence of extracellular Ca(2+), or of CaMKKs inhibitor (STO-609). Phosphorylations of AMPK, CaMKI, and CaMKIV, as well as sperm functions were evaluated. We demonstrate the presence of both CaMKKs (α and β), CaMKI and CaMKIV in chicken sperm. CaMKKα and CaMKI were localized in the acrosome, the midpiece, and at much lower fluorescence in the flagellum, whereas CaMKKβ was mostly localized in the flagellum and much less in the midpiece and the acrosome. CaMKIV was only present in the flagellum. The presence of extracellular calcium induced an increase in kinases phosphorylation and sperm activity. STO-609 reduced AMPK phosphorylation in the presence of extracellular Ca(2+) but not in its absence. STO-609 did not affect CaMKIV phosphorylation but decreased CaMKI phosphorylation and this inhibition was quicker in the presence of extracellular Ca(2+) than in its absence. STO-609 efficiently inhibited sperm motility and AR, both in the presence and absence of extracellular Ca(2+). Our results show for the first time the presence of CaMKKs (α and β) and one of its substrate, CaMKI in different subcellular compartments in germ cells, as well as the changes in the AMPK regulation pathway, sperm motility and AR related to Ca(2+) entry in sperm through the Ca(2+)/CaM/CaMKKs/CaMKI pathway. The Ca(2+)/CaMKKs/AMPK pathway is activated only under conditions of extracellular Ca(2+) entry

Oxidized CaMKII Triggers Atrial Fibrillation

PubMed Central

Purohit, Anil; Rokita, Adam G.; Guan, Xiaoqun; Chen, Biyi; Koval, Olha M.; Voigt, Niels; Neef, Stefan; Sowa, Thomas; Gao, Zhan; Luczak, Elizabeth D.; Stefansdottir, Hrafnhildur; Behunin, Andrew C.; Li, Na; El-Accaoui, Ramzi N.; Yang, Baoli; Swaminathan, Paari Dominic; Weiss, Robert M.; Wehrens, Xander H.T.; Song, Long-Sheng; Dobrev, Dobromir; Maier, Lars S.; Anderson, Mark E.

2013-01-01

Background Atrial fibrillation is a growing public health problem without adequate therapies. Angiotensin II (Ang II) and reactive oxygen species (ROS) are validated risk factors for atrial fibrillation (AF) in patients, but the molecular pathway(s) connecting ROS and AF is unknown. The Ca2+/calmodulin-dependent protein kinase II (CaMKII) has recently emerged as a ROS activated proarrhythmic signal, so we hypothesized that oxidized CaMKIIδ(ox-CaMKII) could contribute to AF. Methods and Results We found ox-CaMKII was increased in atria from AF patients compared to patients in sinus rhythm and from mice infused with Ang II compared with saline. Ang II treated mice had increased susceptibility to AF compared to saline treated WT mice, establishing Ang II as a risk factor for AF in mice. Knock in mice lacking critical oxidation sites in CaMKIIδ (MM-VV) and mice with myocardial-restricted transgenic over-expression of methionine sulfoxide reductase A (MsrA TG), an enzyme that reduces ox-CaMKII, were resistant to AF induction after Ang II infusion. Conclusions Our studies suggest that CaMKII is a molecular signal that couples increased ROS with AF and that therapeutic strategies to decrease ox-CaMKII may prevent or reduce AF. PMID:24030498

Nanoscale modulations in (KLa)(CaW)O-6 and (NaLa)(CaW)O-6

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

Licurse, Mark; Borisevich, Albina Y; Davies, Peter

2012-01-01

Complex nanoscale modulations are identified in two new A-site ordered perovskites, (KLa)(CaW)O{sub 6} and (NaLa)(CaW)O{sub 6}. In (KLa)(CaW)O{sub 6}, selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) show an incommensurate nanocheckerboard modulation with {approx}9.4 x 9.4 a{sub p} periodicity (a{sub p} {approx} 4 {angstrom} for the cubic perovskite aristotype). For (NaLa)(CaW)O{sub 6} a one-dimensional modulation is observed with a {approx}16(1 1 0)a{sub p} repeat; the <1 1 0> orientation of the nanostripes is different from the <1 0 0> stripes observed in other mixed A-site systems. Studies using high temperature x-ray diffraction suggest the formation of the complexmore » modulations is associated with small deviations from the ideal 1:1:1:1 stoichiometry of the (A{sup +}La{sup 3+})(CaW)O{sub 6} phases. Z-contrast images acquired on an aberration-corrected microscope provide evidence for deviations from stoichiometry with a {approx}1:15 periodic arrangement of La{sub 4/3}(CaW)O{sub 6}:(NaLa)(CaW)O{sub 6} nano-phases.« less

Aberrant astrocyte Ca2+ signals "AxCa signals" exacerbate pathological alterations in an Alexander disease model.

PubMed

Saito, Kozo; Shigetomi, Eiji; Yasuda, Rei; Sato, Ryuichi; Nakano, Masakazu; Tashiro, Kei; Tanaka, Kenji F; Ikenaka, Kazuhiro; Mikoshiba, Katsuhiko; Mizuta, Ikuko; Yoshida, Tomokatsu; Nakagawa, Masanori; Mizuno, Toshiki; Koizumi, Schuichi

2018-05-01

Alexander disease (AxD) is a rare neurodegenerative disorder caused by gain of function mutations in the glial fibrillary acidic protein (GFAP) gene. Accumulation of GFAP proteins and formation of Rosenthal fibers (RFs) in astrocytes are hallmarks of AxD. However, malfunction of astrocytes in the AxD brain is poorly understood. Here, we show aberrant Ca 2+ responses in astrocytes as playing a causative role in AxD. Transcriptome analysis of astrocytes from a model of AxD showed age-dependent upregulation of GFAP, several markers for neurotoxic reactive astrocytes, and downregulation of Ca 2+ homeostasis molecules. In situ AxD model astrocytes produced aberrant extra-large Ca 2+ signals "AxCa signals", which increased with age, correlated with GFAP upregulation, and were dependent on stored Ca 2+ . Inhibition of AxCa signals by deletion of inositol 1,4,5-trisphosphate type 2 receptors (IP3R2) ameliorated AxD pathogenesis. Taken together, AxCa signals in the model astrocytes would contribute to AxD pathogenesis. © 2018 Wiley Periodicals, Inc.

PGC-1{alpha} accelerates cytosolic Ca{sup 2+} clearance without disturbing Ca{sup 2+} homeostasis in cardiac myocytes

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

Chen, Min, E-mail: chenminyx@gmail.com; Yunnan Centers for Diseases Prevention and Control, Kunming 650022; Wang, Yanru

2010-06-11

Energy metabolism and Ca{sup 2+} handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1{alpha}) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1{alpha} in cardiac Ca{sup 2+} signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1{alpha} via adenoviral transduction. Our data shows that overexpressing PGC-1{alpha} improved myocyte contractility without increasing the amplitude of Ca{sup 2+}more » transients, suggesting that myofilament sensitivity to Ca{sup 2+} increased. Interestingly, the decay kinetics of global Ca{sup 2+} transients and Ca{sup 2+} waves accelerated in PGC-1{alpha}-expressing cells, but the decay rate of caffeine-elicited Ca{sup 2+} transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca{sup 2+}-ATPase (SERCA2a), but not Na{sup +}/Ca{sup 2+} exchange (NCX) contribute to PGC-1{alpha}-induced cytosolic Ca{sup 2+} clearance. Furthermore, PGC-1{alpha} induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1{alpha} did not disturb cardiac Ca{sup 2+} homeostasis, because SR Ca{sup 2+} load and the propensity for Ca{sup 2+} waves remained unchanged. These data suggest that PGC-1{alpha} can ameliorate cardiac Ca{sup 2+} cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1{alpha}-calcium handing pathway sheds new light on the role of PGC-1{alpha} in the therapy of cardiac diseases.« less

A critical comparison of the current view of Ca signaling with the novel concept of F-actin-based Ca signaling.

PubMed

Lange, Klaus; Gartzke, Joachim

2006-01-01

A detailed comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect - the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating vesicles derived from the endoplasmic/ sarcoplasmic reticulum, which are equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive Ca-release channels/receptors. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of F-actin subunits. Several prominent features of Ca signaling, which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. F-actin is the only known biological Ca-binding system that has been proven by in vitro experiments to work within the physiological range of Ca concentrations and the only system that meets all necessary conditions to function as receptor-operated Ca store and as a coupling device between the Ca store and the store-operated Ca influx pathway. The most important properties of Ca signaling, such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release, turn out to be systematic features of the new concept but remain unexplained by the classical vesicle storage hypothesis. A number of novel findings, specifically recent reports about direct effects of actin-specific toxins on Ca stores, have strengthened the new concept. The concept of F-actin-based Ca signaling combined with the notion of microvillar regulation of ion and substrate fluxes opens new aspects and far-reaching consequences, not only for cellular Ca signaling but also for various other cell functions, and represents an opportunity to connect several fields of cell physiology on the basis of a common mechanism.

Comparative Review of UK-USA Industry-University Relationships

ERIC Educational Resources Information Center

Decter, Moira H.

2009-01-01

Purpose: The purpose of this paper is to explore significant historical changes, legislation and policy in the UK and USA from the 1960s to present day relating to university-industry relationships. Design/methodology/approach: The paper presents a review of papers, reports and policy documents from the UK and USA drawing comparisons of…

Why Does the USA Dominate University League Tables?

ERIC Educational Resources Information Center

Li, Mei; Shankar, Sriram; Tang, Kam Ki

2011-01-01

According to the Academic Ranking of World Universities, the world's top 500 universities are located in only 38 countries, with the USA alone having 157 of them. This article investigates the socioeconomic determinants of the wide performance gap between countries, and whether the USA's dominance is largely due to its economic power. A large…

Ferromagnetic CaRuO3

PubMed Central

Tripathi, Shivendra; Rana, Rakesh; Kumar, Sanjay; Pandey, Parul; Singh, R. S.; Rana, D. S.

2014-01-01

The non-magnetic and non-Fermi-liquid CaRuO3 is the iso-structural analog of the ferromagnetic (FM) and Fermi-liquid SrRuO3. We show that an FM order in the orthorhombic CaRuO3 can be established by the means of tensile epitaxial strain. The structural and magnetic property correlations in the CaRuO3 films formed on SrTiO3 (100) substrate establish a scaling relation between the FM moment and the tensile strain. The strain dependent crossover from non-magnetic to FM CaRuO3 was observed to be associated with switching of non-Fermi liquid to Fermi-liquid behavior. The intrinsic nature of this strain-induced FM order manifests in the Hall resistivity too; the anomalous Hall component realizes in FM tensile-strained CaRuO3 films on SrTiO3 (100) whereas the non-magnetic compressive-strained films on LaAlO3 (100) exhibit only the ordinary Hall effect. These observations of an elusive FM order are consistent with the theoretical predictions of scaling of the tensile epitaxial strain and the magnetic order in tensile CaRuO3. We further establish that the tensile strain is more efficient than the chemical route to induce FM order in CaRuO3. PMID:24464302

Pricing behavior of USA exporter in wheat international market

NASA Astrophysics Data System (ADS)

Wibowo, R. P.; Sumono; Iddrisu, Y.; Darus, M.; Sihombing, L. P.; Jufri

2018-02-01

The number of wheat producing countries is changing over time. It is expected the change in wheat supply will lead world wheat market become more competitive and reduce market power of major exporter country. This paper tries to identify and examined the degree of market power on wheat international market for USA by using the Pricing to Market (PTM) method. USA is the biggest producer and exporter in wheat market. The PTM method found that USA impose noncompetitive strategy by applying price discrimination and apply market power to their importer country.

On Learning the Past Tenses of English Verbs.

DTIC Science & Technology

1985-10-01

RD-AI164 233 ON LEARING THE PAST TENSES OF ENGLISH YERBS(U) vi1 r CALIFORNIA UNIV SAN DIEGO LA JOLLA INST FOR COGNITIVE SCIENCE D E RUMELNART ET AL... COGNITIVE SCIENCE O I$FE13Me~ 0C*" INSTITUTE FOR COGNITIVE SCIENCE UNIVERSITY OF CALIFORNIA, SAN DIEGO LA JOLLA, CALIFORNIA 92093 - *~-’~7...8507 . *** David E. Rurneihart James L. McClelland Institute for Cognitive Science Department of Psychology University of Calif ornia. San Diego

Phosphorylation sites in the Hook domain of CaVβ subunits differentially modulate CaV1.2 channel function.

PubMed

Brunet, Sylvain; Emrick, Michelle A; Sadilek, Martin; Scheuer, Todd; Catterall, William A

2015-10-01

Regulation of L-type calcium current is critical for the development, function, and regulation of many cell types. Ca(V)1.2 channels that conduct L-type calcium currents are regulated by many protein kinases, but the sites of action of these kinases remain unknown in most cases. We combined mass spectrometry (LC-MS/MS) and whole-cell patch clamp techniques in order to identify sites of phosphorylation of Ca(V)β subunits in vivo and test the impact of mutations of those sites on Ca(V)1.2 channel function in vitro. Using the Ca(V)1.1 channel purified from rabbit skeletal muscle as a substrate for phosphoproteomic analysis, we found that Ser(193) and Thr(205) in the HOOK domain of Ca(V)β1a subunits were both phosphorylated in vivo. Ser(193) is located in a potential consensus sequence for casein kinase II, but it was not phosphorylated in vitro by that kinase. In contrast, Thr(205) is located in a consensus sequence for cAMP-dependent phosphorylation, and it was robustly phosphorylated in vitro by PKA. These two sites are conserved in multiple Ca(V)β subunit isoforms, including the principal Ca(V)β subunit of cardiac Ca(V)1.2 channels, Ca(V)β2b. In order to assess potential modulatory effects of phosphorylation at these sites separately from the effects of phosphorylation of the α11.2 subunit, we inserted phosphomimetic or phosphoinhibitory mutations in Ca(V)β2b and analyzed their effects on Ca(V)1.2 channel function in transfected nonmuscle cells. The phosphomimetic mutation Ca(V)β2b(S152E) decreased peak channel currents and shifted the voltage dependence of both activation and inactivation to more positive membrane potentials. The phosphoinhibitory mutation Ca(V)β2b(S152A) had opposite effects. There were no differences in peak Ca(V)1.2 currents or voltage dependence between the phosphomimetic mutation Ca(V)β2b(T164D) and the phosphoinhibitory mutation Ca(V)β2b(T164A). However, calcium-dependent inactivation was significantly increased for the

A Holocene Sediment Record of Phosphorus Accumulation in Shallow Lake Harris, Florida (USA) Offers New Perspectives on Recent Cultural Eutrophication

PubMed Central

Kenney, William F.; Brenner, Mark; Curtis, Jason H.; Arnold, T. Elliott; Schelske, Claire L.

2016-01-01

We studied a complete Holocene sediment record from shallow (zmax = 9.7 m) Lake Harris, Florida (USA) to infer the historical development of the lake and its current eutrophic status. We used 210Pb and 14C to date the 5.9-m sediment sequence (core LH-6-13) and determined accumulation rates for bulk sediment, organic matter, calcium carbonate, phosphorus fractions and biogenic silica fractions. The chronology of changes in sediment characteristics for LH-6-13 is consistent with the general paleoenvironmental framework established by core studies from other Florida lakes. Lake Harris began to fill with water in the early Holocene, ca. 10,680 cal a BP. A shift from carbonate-dominated to organic-rich sediments ca. 5,540 cal a BP corresponds to a transition to wetter climate in the middle Holocene. A rapid increase in diatom biogenic silica concentrations and accumulation rates ca. 2,600 cal a BP signals that the lake had deepened to its modern limnetic state. In LH-6-13, an up-core decrease in rates of accumulation for several sediment variables indicates time-course oligotrophication of the lake through the Holocene. In near-surface sediments, abrupt increases in the accumulation rates of these same variables indicate progressive cultural eutrophication after ca. AD 1900. Comparison of the modern state of Lake Harris to its condition 50–100 years ago provides a measure of the impact of recent cultural eutrophication. Because the pre-disturbance trajectory of this lake was one of oligotrophication, the true impact of cultural eutrophication is even greater than what is inferred from the changes over the past century. PMID:26789518

Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4: Calculated dehydrogenation enthalpy, including zero point energy, and the structure of the phonon spectra.

PubMed

Marashdeh, Ali; Frankcombe, Terry J

2008-06-21

The dehydrogenation enthalpies of Ca(AlH(4))(2), CaAlH(5), and CaH(2)+6LiBH(4) have been calculated using density functional theory calculations at the generalized gradient approximation level. Harmonic phonon zero point energy (ZPE) corrections have been included using Parlinski's direct method. The dehydrogenation of Ca(AlH(4))(2) is exothermic, indicating a metastable hydride. Calculations for CaAlH(5) including ZPE effects indicate that it is not stable enough for a hydrogen storage system operating near ambient conditions. The destabilized combination of LiBH(4) with CaH(2) is a promising system after ZPE-corrected enthalpy calculations. The calculations confirm that including ZPE effects in the harmonic approximation for the dehydrogenation of Ca(AlH(4))(2), CaAlH(5), and CaH(2)+6LiBH(4) has a significant effect on the calculated reaction enthalpy. The contribution of ZPE to the dehydrogenation enthalpies of Ca(AlH(4))(2) and CaAlH(5) calculated by the direct method phonon analysis was compared to that calculated by the frozen-phonon method. The crystal structure of CaAlH(5) is presented in the more useful standard setting of P2(1)c symmetry and the phonon density of states of CaAlH(5), significantly different to other common complex metal hydrides, is rationalized.

Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4: Calculated dehydrogenation enthalpy, including zero point energy, and the structure of the phonon spectra

NASA Astrophysics Data System (ADS)

Marashdeh, Ali; Frankcombe, Terry J.

2008-06-01

The dehydrogenation enthalpies of Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 have been calculated using density functional theory calculations at the generalized gradient approximation level. Harmonic phonon zero point energy (ZPE) corrections have been included using Parlinski's direct method. The dehydrogenation of Ca(AlH4)2 is exothermic, indicating a metastable hydride. Calculations for CaAlH5 including ZPE effects indicate that it is not stable enough for a hydrogen storage system operating near ambient conditions. The destabilized combination of LiBH4 with CaH2 is a promising system after ZPE-corrected enthalpy calculations. The calculations confirm that including ZPE effects in the harmonic approximation for the dehydrogenation of Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 has a significant effect on the calculated reaction enthalpy. The contribution of ZPE to the dehydrogenation enthalpies of Ca(AlH4)2 and CaAlH5 calculated by the direct method phonon analysis was compared to that calculated by the frozen-phonon method. The crystal structure of CaAlH5 is presented in the more useful standard setting of P21/c symmetry and the phonon density of states of CaAlH5, significantly different to other common complex metal hydrides, is rationalized.

Morphometric Parameters of Pyramidal Cells in CA1-CA4 Fields in the Hippocampus of Arctic Fox (Vulpes lagopus).

PubMed

Łuszczewska-Sierakowska, Iwona; Wawrzyniak-Gacek, Agata; Guz, Tomasz; Tatara, Marcin R; Charuta, Anna

2015-01-01

The aim of the study was a quantitative examination of neurons of hippocampal subfields (CA1-CA4) in mature male Arctic fox (Vulpes lagopus; syn. Alopex lagopus). The preparations were dyed using cresyl violet. Histological preparations were used to morphometricaly analyze the neurons of hippocampus. This analysis included the following parameters: average size of cells in μm, periphery of cells in μm, average cell area in μm2, percentage of cells in area and size of the largest and smallest cells in μm in CA1-CA4 fields. Morphometric observations show that the cells involved in hippocampal formation in polar fox in all layers CA1 -CA4 differ in size, shape, cell area and nucleus area. The size of the cell area in CA3 is the largest and fluctuates around 249.4 μm2, whereas in CA2 the cell area is 184.1 μm2. The cells of the CA2 field are densely arranged, pyramidal and contain a small amount of cytoplasm; their size fluctuates. Cells of CA2 and CA4 had the largest diameter of about 23.6 μm, whereas cells of the CA3 field had the smallest diameter of about 8.3 μm.

Basque Diaspora in the USA and Language Maintenance

ERIC Educational Resources Information Center

Lasagabaster, David

2008-01-01

The Basques first immigrated on a large scale to the USA during the Gold Rush of 1848. After immigrating to the USA, they settled in pockets throughout the West, especially in California, Nevada and Idaho, and it is currently estimated that more than 35,000 Basque-Americans live in these three states. This represents one of the largest…

Encoding, consolidation, and retrieval of contextual memory: differential involvement of dorsal CA3 and CA1 hippocampal subregions.

PubMed

Daumas, Stéphanie; Halley, Hélène; Francés, Bernard; Lassalle, Jean-Michel

2005-01-01

Studies on human and animals shed light on the unique hippocampus contributions to relational memory. However, the particular role of each hippocampal subregion in memory processing is still not clear. Hippocampal computational models and theories have emphasized a unique function in memory for each hippocampal subregion, with the CA3 area acting as an autoassociative memory network and the CA1 area as a critical output structure. In order to understand the respective roles of the CA3- and CA1-hippocampal areas in the formation of contextual memory, we studied the effects of the reversible inactivation by lidocaine of the CA3 or CA1 areas of the dorsal hippocampus on acquisition, consolidation, and retrieval of a contextual fear conditioning. Whereas infusions of lidocaine never impaired elementary tone conditioning, their effects on contextual conditioning provided interesting clues about the role of these two hippocampal regions. They demonstrated first that the CA3 area is necessary for the rapid elaboration of a unified representation of the context. Secondly, they suggested that the CA1 area is rather involved in the consolidation process of contextual memory. Third, they showed that CA1 or CA3 inactivation during retention test has no effect on contextual fear retrieval when a recognition memory procedure is used. In conclusion, our findings point as evidence that CA1 and CA3 subregions of the dorsal hippocampus play important and different roles in the acquisition and consolidation of contextual fear memory, whereas they are not required for context recognition.

Kinetics of Ca2+ binding to parvalbumin in bovine chromaffin cells: implications for [Ca2+] transients of neuronal dendrites

PubMed Central

Lee, Suk-Ho; Schwaller, Beat; Neher, Erwin

2000-01-01

The effect of parvalbumin (PV) on [Ca2+] transients was investigated by perfusing adrenal chromaffin cells with fura-2 and fluorescein isothiocyanate (FITC)-labelled PV. As PV diffused into cells, the decay of [Ca2+] transients was transformed from monophasic into biphasic. The proportion of the initial fast decay phase increased in parallel with the fluorescence intensity of FITC, indicating that PV is responsible for the initial fast decay phase.The relationship between the fast decay phase and the [Ca2+] level was investigated using depolarizing trains of stimuli. Within a train the relative amplitude of the fast decay phase was inversely dependent on the [Ca2+] level preceding a given stimulus.Based on these observations, we estimated the Ca2+ binding ratio of PV (κP), the apparent dissociation constant of PV for Ca2+ (Kdc,app), and the unbinding rate constant of Ca2+ from PV (kc-) in the cytosol of chromaffin cells. Assuming free [Mg2+] to be 0.14 mm, we obtained values of 51.4 ± 2.0 nm (n = 3) and 0.95 ± 0.026 s−1 (n = 3), for Kdc,app and kc-, respectively.With the parameters obtained in the perfusion study, we simulated [Ca2+] transients, using two different Ca2+ extrusion rates (γ) – 20 and 300 s−1– which represent typical values for chromaffin cells and neuronal dendrites, respectively. The simulation indicated that Ca2+ is pumped out before it is equilibrated with PV, when γ is comparable to the equilibration rates between PV and Ca2+, resulting in the fast decay phase of a biexponential [Ca2+] transient.From these results we conclude that Ca2+ buffers with slow kinetics, such as PV, may cause biexponential decays in [Ca2+] transients, thereby complicating the analysis of endogenous Ca2+ binding ratios (κS) based on time constants. Nevertheless, estimates of κS based on Ca2+ increments provide reasonable estimates for Ca2+ binding ratios before equilibration with PV. PMID:10835044

Perceived discrimination among three groups of refugees resettled in the USA: associations with language, time in the USA, and continent of origin.

PubMed

Hadley, Craig; Patil, Crystal

2009-12-01

The objectives of this study were to assess the prevalence and predictors of discrimination among a community-based sample of refugees resettled in the USA. We sought to test whether language, gender, time in the USA and country of origin were associated with the experience of discrimination among individuals resettled in the USA as part of the refugee resettlement program. Perceived discrimination was assessed among individuals from East Africa (n = 92), West Africa (n = 74), and from Eastern Europe (n = 112) using a multi-item measure of discrimination. Bivariate associations revealed statistically significant associations between experiences of discrimination and time in the USA, language ability, and sending country. A logistic regression model revealed that refugees from African sending countries were more likely than Eastern European individuals to experience discrimination, even after controlling for potentially confounding factors. We interpret this finding as evidence of racism and discuss the implications for population health and resettlement practice.

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival is measured by a laser at the NASA Stage. A NASA Staff member describes the Ice, Cloud, and land Elevation Satellite (ICESat) mission, which operated from 2003-2009, and pioneered the use of laser altimeters in space to study the elevation of the Earth's surface and its changes. ICESat-2 is a follow-on mission to continue the ICESat observations and is scheduled to launch in 2017. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

Two boys attending the USA Science and Engineering Festival pose with Robonaut 2 at the NASA Stage. Robonaut 2 is NASA's first dexterous humanoid robot that has been working on the International Space Station for the last three years. R2 recently received 1.2 meter long legs to allow mobility. This will enable R2 to assist more with regular and repetitive tasks inside and outside the station. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Formation Mechanism of CaS-Bearing Inclusions and the Rolling Deformation in Al-Killed, Low-Alloy Steel with Ca Treatment

NASA Astrophysics Data System (ADS)

Xu, Guang; Jiang, Zhouhua; Li, Yang