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Sample records for ultimate ph phu

  1. The in vitro digestibility of beef varies with its inherent ultimate pH.

    PubMed

    Farouk, Mustafa M; Wu, Guojie; Frost, Deborah A; Clerens, Stefan; Knowles, Scott O

    2014-11-01

    Animal carcasses and cuts of meat are usually differentiated and valued according to size and compositional attributes. An underappreciated variable of red meat is its inherent ultimate pH (pHu) value, which affects organoleptic and processing characteristics. This study tests the hypothesis that high pHu aged meat would be more digestible than low pHu unaged (fresh) meat. Longissimus dorsi muscles collected from 59 bull carcasses had pHu values of 5.6-6.9. These were aged for 21 days at -1.5 °C, then raw and cooked (72 °C) samples were enzymatically digested at 37 °C with pepsin (pH 1.9 for 90 min) followed by pancreatin (pH 8.0 for an additional 120 min) to simulate conditions in the stomach and small intestine, respectively. Meat proteins and peptides in the digests were separated by 1D SDS PAGE. Regardless of pHu, ageing or cooking, most sarcoplasmic and myofibrillar proteins were rapidly digested by pepsin, with concomitant release of products identified by LC-MS/MS as mainly myosin-1, -2 and -7, α-actinin-2 or -3 and tropomyosin beta and alpha chains. These products were resistant to further digestion for the entire 210 min duration of the incubation. In terms of rate and extent of digestibility of these resistant products, high pHu > low pHu (P < 0.001), whereas aged > unaged (P < 0.003), with the effect of cooking dependent on pHu and varying somewhat by protein. Overall, the digestibility of meat samples increased with increasing pHu (P < 0.001). Beef meat was highly digestible but could be further differentiated on the basis of its pHu and the ease of digestibility of proteins. Specific carcasses or cuts could be targeted to consumer groups in order to provide benefits and add value.

  2. Variation in bull beef quality due to ultimate muscle pH is correlated to endopeptidase and small heat shock protein levels.

    PubMed

    Pulford, D J; Dobbie, P; Fraga Vazquez, S; Fraser-Smith, E; Frost, D A; Morris, C A

    2009-09-01

    This study set out to determine if ultimate pH (pH(u)) affected the performance of intracellular small heat shock protein and endopeptidase dynamics in muscle during beef ageing. Longissimus dorsi muscles from 39 Angus or Limousin×Angus bulls were examined to see if pH(u) achieved at 22h post mortem (rigor) affected tenderness and water holding capacity of beef. Samples were segregated into three pH(u) groups termed high (pH>6.3), intermediate (5.7<pH<6.3) and low (pH<5.7) pH(u) beef. More than 30% of bull beef did not achieve acceptable tenderness at 8 days post mortem with this ageing regime. No significant differences in calpain or cathepsin enzyme levels due to meat pH were observed until after 22h post mortem, but low pH(u) beef had elevated caspase 3/7 activity soon after slaughter. At 22h post mortem, greater levels of μ-calpain enzyme were found in the high and intermediate pH(u) beef and cathepsin B levels were superior in the low pH(u) beef after 2 days post mortem. Different rates of desmin and troponin T protein degradation were also observed in aged bull beef. Both proteins were degraded within 6h post mortem for high pH(u) beef, but took >3 days post mortem for intermediate pH(u) beef. High levels of alpha β-crystallin (aβC) at 22h post mortem coincided with delayed muscle protein degradation for low pH(u) beef. Our results support the hypothesis that aβC shields myofibrils and buffers against endopeptidase degradation of beef structure during ageing. PMID:20416615

  3. Serum and Muscle Metabolomics for the Prediction of Ultimate pH, a Key Factor for Chicken-Meat Quality.

    PubMed

    Beauclercq, Stéphane; Nadal-Desbarats, Lydie; Hennequet-Antier, Christelle; Collin, Anne; Tesseraud, Sophie; Bourin, Marie; Le Bihan-Duval, Elisabeth; Berri, Cécile

    2016-04-01

    Variations in muscle glycogen storage are highly correlated with variations in meat ultimate pH (pHu), a key factor for poultry meat quality. A total of two chicken lines were divergently selected on breast pHu to understand the biological basis for variations in meat quality (i.e., the pHu- and the pHu+ lines that are characterized by a 17% difference in muscle glycogen content). The effects of this selection on bird metabolism were investigated by quantifying muscle metabolites by high-resolution NMR ((1)H and (31)P) and serum metabolites by (1)H NMR. A total of 20 and 26 discriminating metabolites between the two lines were identified by orthogonal partial least-squares discriminant analysis (OPLS-DA) in the serum and muscle, respectively. There was over-representation of carbohydrate metabolites in the serum and muscle of the pHu- line, consistent with its high level of muscle glycogen. However, the pHu+ line was characterized by markers of oxidative stress and muscle catabolism, probably because of its low level of energy substrates. After OPLS-DA multiblock analysis, a metabolic set of 15 high-confidence biomarkers was identified that could be used to predict the quality of poultry meat after validation on an independent population.

  4. Impact of divergent selection for ultimate pH of pectoralis major muscle on biochemical, histological, and sensorial attributes of broiler meat.

    PubMed

    Alnahhas, N; Le Bihan-Duval, E; Baéza, E; Chabault, M; Chartrin, P; Bordeau, T; Cailleau-Audouin, E; Meteau, K; Berri, C

    2015-09-01

    The impact of divergent selection based on the ultimate pH (pHu) of pectoralis major (P. major) muscle on the chemical, biochemical, and histological profiles of the muscle and sensorial quality of meat was investigated in broiler chickens. The protein, lipid, DM, glycogen and lactate content, glycolytic potential, proteolysis, lipid and protein oxidation index, muscle fiber cross-sectional area, capillary density, and collagen surface were determined on the breast P. major muscle of 6-wk-old broilers issued from the high-pHu (pHu+) and low-pHu (pHu-) lines. Sensory attributes were also evaluated on the breast (roasted or grilled) and thigh (roasted) meat of the 2 lines. Protein, lipid, and DM content of P. major muscle were not affected by selection ( > 0.05). However, the P. major muscle of the pHu+ line was characterized by lower residual glycogen (-16%; ≤ 0.001) and lactate (-14%; ≤ 0.001) content and lower glycolytic potential (-14%; ≤ 0.001) compared with the pHu- line. Although the average cross-sectional area of muscle fibers and surface occupied by collagen were similar ( > 0.05) in both lines, fewer capillaries per fiber (-15%; ≤ 0.05) were observed in the pHu+ line. The pHu+ line was also characterized by lower lipid oxidation (thiobarbituric acid reactive substance index: -23%; ≤ 0.05) but protein oxidation and proteolysis index were not different ( > 0.05) between the 2 lines. At the sensory level, selection on breast muscle pHu mainly affected the texture of grilled and roast breast meat, which was judged significantly more tender ( ≤ 0.001) in the pHu+ line, and the acid taste, which was less pronounced in the roasted breast meat of the pHu+ line ( ≤ 0.002). This study highlighted that selection based on pHu does not affect the chemical composition and structure of breast meat. However, by modifying muscle blood supply and glycogen turnover, it affects meat acidity and oxidant status, both of which are likely to contribute to the large

  5. Relationships between ultimate pH and microbial, chemical, and physical characteristics of vacuum-packaged pork loins.

    PubMed

    Knox, B L; van Laack, R L J M; Davidson, P M

    2008-04-01

    This study evaluated the effect of ultimate pH (pHu) of pork on shelf life based upon microbial growth, drip loss, and oxidative rancidity (2-thiobarbituric acid [TBA] procedure) in vacuum-packaged loins stored at 4 degrees C. Glucose and lactate concentrations of the pork loins were also measured. Thirty-six pork loins (pH = 5.56 to 6.57) were collected at a commercial slaughter facility 1-d postslaughter. All pigs were from the same genetic line. Loins were grouped by pH (group: pH range): A: 5.55 to 5.70, B: 5.71 to 5.85, C: 5.86 to 6.00, D: 6.01 to 6.15, and E: > 6.16. They were analyzed at days 0, 6, 14, 24, and 34. For aerobic plate counts, groups A and B were significantly lower than C through E, while psychrotrophic or Enterobacteriaceae counts of groups A and A through C were significantly lower than groups B through E and D and E, respectively. Lactic acid bacteria counts were not significantly influenced by pHu. Group A had higher glucose concentrations than groups C through E and higher lactate concentrations than groups D through E on most sampling days. Group A had a higher TBA value than group E at days 0 and 34. Group A displayed greater drip loss than groups D and E at day 6 and groups B through D on days 24 and 34. Based on the microbial and drip loss results, a pork loin pHu of 5.8 to 5.9 appears to be optimum to provide a vacuum-packaged shelf life of at least 24 d with minimum drip loss. PMID:18387112

  6. Excess glycogen does not resolve high ultimate pH of oxidative muscle.

    PubMed

    England, Eric M; Matarneh, Sulaiman K; Oliver, Emily M; Apaoblaza, Ariel; Scheffler, Tracy L; Shi, Hao; Gerrard, David E

    2016-04-01

    Skeletal muscle glycogen content can impact the extent of postmortem pH decline. Compared to glycolytic muscles, oxidative muscles contain lower glycogen levels antemortem which may contribute to the higher ultimate pH. In an effort to explore further the participation of glycogen in postmortem metabolism, we postulated that increasing the availability of glycogen would drive additional pH decline in oxidative muscles to equivalent pH values similar to the ultimate pH of glycolytic muscles. Glycolysis and pH declines were compared in porcine longissimus lumborum (glycolytic) and masseter (oxidative) muscles using an in vitro system in the presence of excess glycogen. The ultimate pH of the system containing longissimus lumborum reached a value similar to that observed in intact muscle. The pH decline of the system containing masseter samples stopped prematurely resulting in a higher ultimate pH which was similar to that of intact masseter muscle. To investigate further, we titrated powdered longissimus lumborum and masseter samples in the reaction buffer. As the percentage of glycolytic sample increased, the ultimate pH decreased. These data show that oxidative muscle produces meat with a high ultimate pH regardless of glycogen content and suggest that inherent muscle factors associated with glycolytic muscle control the extent of pH decline in pig muscles.

  7. Further investigations into the relationship between ultimate pH and tenderness for beef samples from bulls and steers.

    PubMed

    Purchas, R W; Aungsupakorn, R

    1993-01-01

    Samples of longissimus dorsi muscle from 150 cattle comprising Friesian bulls and steers and Charolais × Angus cross steers, were used to investigate the nature of the relationship between ultimate pH and beef tenderness under conditions where cold-shortening was avoided. A modified Warner-Bratzler (WB) shear machine with a square- rather than a vee-blade enabled several aspects of tenderness to be evaluated, including peak force (PF), initial yield force (IY), PF-IY, and an index of total work done. The two steer groups differed little in meat quality characteristics, but, in terms of six major hindquarter cuts, the Charolais cross group yielded 14·3% more meat per unit live weight, due to a combination of a superior dressing-out percent and a higher cutability. Relative to Friesian steers, the bulls produced beef with a higher ultimate pH (P < 0·001), and after adjustment to a common pH, the bull beef was tougher for all WB parameters except PF-IY. Cooking loss was higher for beef from bulls after adjustment for pH. Although reduced by pH adjustment, beef from bulls remained significantly darker than that from steers (P < 0·05) based on reflectance measurements. Maximum toughness in terms of PF, IY, and work index was at an ultimate pH of 6·0-6·1, but the peak was much less clear for PF-IY. The decline in tenderness with an increase in ultimate pH to 6·2 was associated with a decrease in sarcomere length. This result supports a previous suggestion that shortening explains, at least in part, the lower average tenderness at intermediate pH values. PMID:22060661

  8. The effects of early post-mortem pH and ultimate pH on level and amount of destructured zones in cooked cured hams.

    PubMed

    Hugenschmidt, Gabriel; Hadorn, Ruedi; Scheeder, Martin R L; Silacci, Paolo; Scherrer, Daniel; Wenk, Caspar

    2010-08-01

    Effects of early (1h p.m. and 3h p.m.) and ultimate pH (24h p.m.) on level and amount of destructured zones in cooked cured hams were evaluated. In experiment 1, electrically stimulated (50 V, 14 Hz, 2 x 90s) and non-stimulated carcass halves, both in combination with two cooling procedures (2 degrees C from 30 min p.m. vs. 120 min p.m.) resulted in 1.5-35.2g/kg destructured zones in silversides and 58.4-120.0 g/kg destructured zones in topsides. A high temperature 1h p.m. in silversides (P=0.067) and topsides (P=0.054) was identified as the most important predictor for the defect. In experiment 2, cooked cured hams from topsides selected according to ultimate pH groups (pH<5.5, pH 5.5-5.7, pH>5.7) showed between 12.3 and 61.8 g/kg destructured zones. Ultimate pH was specified as most important, however, statistically still not significant (P=0.135) predictor for the defect. Chemical analysis resulted in low crude ash and high dry matter content as being characteristic for the defect.

  9. Ultimate Frisbee.

    ERIC Educational Resources Information Center

    Clark, Ed; And Others

    1981-01-01

    Ultimate Frisbee is a highly competitive noncontact sport similar to football or soccer, played by two teams of seven or more members. Various aspects of the game are described, including: (1) equipment; (2) playing field; and (3) the rules and scoring system. (JN)

  10. The impact of ultimate pH on muscle characteristics and sensory attributes of the longissimus thoracis within the dark cutting (Canada B4) beef carcass grade.

    PubMed

    Holdstock, J; Aalhus, J L; Uttaro, B A; López-Campos, O; Larsen, I L; Bruce, H L

    2014-12-01

    Canada B4 beef carcasses are penalized because the longissimus thoracis (LT) at the grade site (12-13th ribs) is darker than the color threshold for normal bright cherry-red beef. Previous studies have shown that not all B4 carcasses have pH>6.0; therefore, the relationship between LT pH and meat quality was investigated by collecting thirty half-carcasses comprised of the following: ten Canada AA (AA, control), ten B4 with LT pH>6.0 (CL, classic), and ten B4 with LT pH<6.0 (AT, atypical). LT from CL carcasses had the lowest mean lactate level, lowest glucidic potential and highest mean pH value. LT muscle from CL and AT carcasses was dark and had decreased purge, drip loss and cooking loss. Warner-Bratzler shear force values and sensory panel results showed that AT beef was toughest (P<0.0001), substantiating economic penalty. Causal mechanisms for AT carcasses may be inconsistent with traditional DFD theory because of close to normal final muscle pH. PMID:25173716

  11. Sequence stratigraphy and hydrocarbon potential of the Phu Khanh Basin offshore central Vietnam, South China Sea

    SciTech Connect

    Lee, G.H.; Watkins, J.S.

    1996-12-31

    The Phu Khanh Basin offshore central Vietnam is one of the few untested basins on the Vietnam margin of the South China Sea. Analysis of over 1,600 km of multi-channel seismic reflection data indicates that the Phu Khanh Basin follows a typical rift-margin order: faulted basement, synrift sedimentation, a breakup unconformity, and postrift sedimentation. Postrift sedimentation consists of a transgressive phase characterized by ramp-like depositional geometries followed by a regressive phase characterized by prograding sequences. An early middle Miocene unconformity separates these two phases. During the transgressive phase rising sea level provided favorable conditions for carbonate buildup development. The regressive interval contains a number of third-order depositional sequences composed of seismically resolvable lowstand, highstand, and rarely, transgressive systems tracts. Lacustrine sediments deposited in graben and half-graben lakes during the rifting stage are probably the principal source rocks. Fractured and/or weathered basement, carbonate complexes, basinfloor fans, and shallows water sands may have good reservoir quality. Potential traps include basement hills, carbonate complexes, fault taps, and stratigraphic traps within lowstand systems tracts. Hydrocarbon indicators such as flat spots, bright spots, gas chimneys with gas mounds on the seafloor occur at a number of locations.

  12. Sequence stratigraphy and hydrocarbon potential of the Phu Khanh Basin offshore central Vietnam, South China Sea

    SciTech Connect

    Lee, G.H. ); Watkins, J.S. )

    1996-01-01

    The Phu Khanh Basin offshore central Vietnam is one of the few untested basins on the Vietnam margin of the South China Sea. Analysis of over 1,600 km of multi-channel seismic reflection data indicates that the Phu Khanh Basin follows a typical rift-margin order: faulted basement, synrift sedimentation, a breakup unconformity, and postrift sedimentation. Postrift sedimentation consists of a transgressive phase characterized by ramp-like depositional geometries followed by a regressive phase characterized by prograding sequences. An early middle Miocene unconformity separates these two phases. During the transgressive phase rising sea level provided favorable conditions for carbonate buildup development. The regressive interval contains a number of third-order depositional sequences composed of seismically resolvable lowstand, highstand, and rarely, transgressive systems tracts. Lacustrine sediments deposited in graben and half-graben lakes during the rifting stage are probably the principal source rocks. Fractured and/or weathered basement, carbonate complexes, basinfloor fans, and shallows water sands may have good reservoir quality. Potential traps include basement hills, carbonate complexes, fault taps, and stratigraphic traps within lowstand systems tracts. Hydrocarbon indicators such as flat spots, bright spots, gas chimneys with gas mounds on the seafloor occur at a number of locations.

  13. Spectroscopic Determination of Distinct Heme Ligands in Outer-Membrane Receptors PhuR and HasR of Pseudomonas aeruginosa

    PubMed Central

    Smith, Aaron D.; Modi, Anuja R.; Sun, Shengfang; Dawson, John H.; Wilks, Angela

    2015-01-01

    Pseudomonas aeruginosa PAO1 encodes two outer membrane receptors, PhuR (Pseudomonas heme uptake) and HasR (heme assimilation system). The HasR receptor acquires heme through interaction with a secreted hemophore, HasAp. The non-hemophore-dependent PhuR is encoded along with proteins required for heme translocation into the cytoplasm. Herein, we report the isolation and characterization of the HasR and PhuR receptors. Absorption and MCD spectroscopy confirmed that, similar to other Gram-negative OM receptors, HasR coordinates heme through the conserved N-terminal plug His-221 and His-624 of the surface-exposed FRAP-loop. In contrast, PhuR showed distinct absorption and MCD spectra consistent with coordination through a Tyr residue. Sequence alignment of PhuR with all known Gram-negative OM heme receptors revealed a lack of a conserved His within the FRAP loop but two Tyr residues at positions 519 and 529. Site-directed mutagenesis and spectroscopic characterization confirmed Tyr-519 and the N-terminal plug His-124 provide the heme ligands in PhuR. We propose that PhuR and HasR represent nonredundant heme receptors capable of sensing and accessing heme across a wide range of physiological conditions on colonization and infection of the host. PMID:25849630

  14. Preliminary 40Ar-39Ar thermochronological study of Dien Bien Phu Fault, northern Vietnam

    NASA Astrophysics Data System (ADS)

    Lin, T.; Lo, C.; Wang, P.; Lee, T.; Chung, S.; Lan, C.

    2003-12-01

    The Song Ma belt, located along the suture zone between the South China and Indochina blocks, was offset by the Dien Bien Phu Fault (DBF) in northern Vietnam. Many previous studies suggested that the Dien Bien Phu Fault is one of the Tertiary shear zones, resulted from the Cenozoic extrusion tectonics due to the Eurasian-Indian collision. However, the timing of the movement of DBF is remained unclear due to lacking of age data. In the present study, schists and mylonitic granites from DBF, and undeformed granites from the granitic belt along the south China block, were analysed by 40Ar-39Ar method. K-feldspar, hornblende, and biotite samples form granite plutons along south edge of South China block displayed different age ranges between opposite sides of DBF. Samples from plutonic body which is located in west side exhibit plateau ages ranging form 207Ma to 229Ma. Whereas, hornblende separates from granites on the west side exhibit much older plateau dates at around 277Ma. More detail studies were required to get better understand about the discrepancy of dating results between granitic masses located in different sides of DBF. On the other hand, Laser 40Ar-39Ar single-grain analyses conducted on deformed biotites and muscovites separated from the schists in DBF, show 40Ar-39Ar ages ranging form 185Ma to 205Ma, which are much younger than the plateau dates of those undeformed granitic samples. In summary, K-feldspar, hornblende and biotite samples from the undeformed granites, exhibit plateau dates in the range of 207- 277Ma, reflecting the ages of plutonism during the Indosinian orogeny. Whereas, muscovites and biotites extracted from schists and deformed granites in DBF, display young 40Ar-39Ar ages in the range of 205-185 Ma. This may suggest that although the DBF might have been reactivated during the Cenozoic extrusion tectonics, but it was in fact active in the Mesozoic.

  15. The Ultimate Fizz

    ERIC Educational Resources Information Center

    Heckscher, Mary

    2008-01-01

    Many recipes for elementary science activities suggest making carbon dioxide from baking soda and vinegar; however, they often do not give exact measurements of the ingredients. The author was able to turn this "drawback" into a plus by challenging her fifth-grade students to find the "ultimate fizz"--i.,e., "What amount of baking soda added to a…

  16. Education and Ultimate Meaning

    ERIC Educational Resources Information Center

    Schinkel, Anders

    2015-01-01

    Richard Peters and John White have both argued that education should contribute to the meaning people are able to find in or give to life. Both dismiss the idea of ultimate or profound meaning ("the meaning of life") in favour of ordinary meaning, or "meaning in life". Thus they exemplify the trend visible also in the general…

  17. Information: The Ultimate Frontier.

    ERIC Educational Resources Information Center

    Branscomb, Lewis M.

    1979-01-01

    A 100-year scenario of the future of information technology. To achieve inexpensive, high-speed, and small computers, new techniques are likely to replace silicon technology. The ultimate computer might be biological and patterned on DNA. Future computers will require information rather than store it. Light wave communication will broaden…

  18. The Ultimate PE Challenge

    ERIC Educational Resources Information Center

    Cerny, Eleanor; Wojehowski, Ken

    2005-01-01

    This article features the Ultimate PE Challenge. The idea had been born when the fifth-grade teachers complained that teaching physical geography was boring, and the technology instructor simultaneously noticed a climbing wall in the gym. "Could physical education simulate the geographic characteristics and obstacles of North America?" This…

  19. The Ultimate Alternative. A Curriculum for Teaching Ultimate.

    ERIC Educational Resources Information Center

    Caporali, John Martin

    1988-01-01

    A curriculum for teaching Ultimate, a cardiovascular frisbee disc sport alternative to traditional ball sports, is presented, covering cognitive, psychomotor, and affective skills at three different levels. (CB)

  20. Ultimate Realities: Deterministic and Evolutionary

    ERIC Educational Resources Information Center

    Moxley, Roy A.

    2007-01-01

    References to ultimate reality commonly turn up in the behavioral literature as references to determinism. However, this determinism is often difficult to interpret. There are different kinds of determinisms as well as different kinds of ultimate realities for a behaviorist to consider. To clarify some of the issues involved, the views of ultimate…

  1. GPS measurements of horizontal deformation across the Lai Chau-Dien Bien (Dien Bien Phu) fault, in Northwest of Vietnam, 2002-2004

    NASA Astrophysics Data System (ADS)

    Duong, C. C.; Yun, H.-S.; Cho, J.-M.

    2006-05-01

    Global Positioning System (GPS) measurements from Feb. 2002 through Mar. 2004 were used to estimate the recent crustal movement along the Lai Chau - Dien Bien (Dien Bien Phu) fault (LC-DBF) system in the Northwest of Vietnam. Four GPS campaign data were processed to estimate ITRF2000 and local horizontal velocities, as well as extensive and compressive strain rates across the LC-DBF. ITRF2000 velocities are consistent with east-southeastward movement of Sundaland i.e. Indochina. Local velocities did not reveal much left-lateral strike-slip of the fault system and the derived strain rates were insignificantly different from zero at 95% confidence.

  2. Ultimate Realities: Deterministic and Evolutionary

    PubMed Central

    Moxley, Roy A

    2007-01-01

    References to ultimate reality commonly turn up in the behavioral literature as references to determinism. However, this determinism is often difficult to interpret. There are different kinds of determinisms as well as different kinds of ultimate realities for a behaviorist to consider. To clarify some of the issues involved, the views of ultimate realities are treated as falling along a continuum, with extreme views of complete indeterminism and complete determinism at either end and various mixes in between. Doing so brings into play evolutionary realities and the movement from indeterminism to determinism, as in Peirce's evolutionary cosmology. In addition, this framework helps to show how the views of determinism by B. F. Skinner and other behaviorists have shifted over time. PMID:22478489

  3. Ultimate Cost of Building Walls.

    ERIC Educational Resources Information Center

    Grimm, Clayford T.; Gross, James G.

    The need for economic analysis of building walls is discussed, and the factors influencing the ultimate cost of exterior walls are studied. The present worth method is used to analyze three types of exterior non-loadbearing panel or curtain walls. Anticipated costs are expressed in terms of their present value per square foot of wall area. The…

  4. Shear wall ultimate drift limits

    SciTech Connect

    Duffey, T.A.; Goldman, A.; Farrar, C.R.

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  5. Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

    PubMed

    Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

    2015-07-07

    We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes.

  6. Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

    PubMed

    Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

    2015-01-01

    We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes. PMID:26250010

  7. Ultimate justification: Wittgenstein and medical ethics.

    PubMed Central

    Hughes, J

    1995-01-01

    Decisions must be justified. In medical ethics various grounds are given to justify decisions, but ultimate justification seems illusory and little considered. The philosopher Wittgenstein discusses the problem of ultimate justification in the context of general philosophy. His comments, nevertheless, are pertinent to ethics. From a discussion of Wittgensteinian notions, such as 'bedrock', the idea that 'ultimate' justification is grounded in human nature as such is derived. This discussion is relevant to medical ethics in at least five ways: it shows generally what type of certainty there is in practical ethics; it seems to imply some objective foundation to our ethical judgements; it squares with our experience of making ethical decisions; it shows something of the nature of moral arguments; and, finally, it has implications for teaching medicine and ethics. PMID:7776343

  8. Ultimate justification: Wittgenstein and medical ethics.

    PubMed

    Hughes, J

    1995-02-01

    Decisions must be justified. In medical ethics various grounds are given to justify decisions, but ultimate justification seems illusory and little considered. The philosopher Wittgenstein discusses the problem of ultimate justification in the context of general philosophy. His comments, nevertheless, are pertinent to ethics. From a discussion of Wittgensteinian notions, such as 'bedrock', the idea that 'ultimate' justification is grounded in human nature as such is derived. This discussion is relevant to medical ethics in at least five ways: it shows generally what type of certainty there is in practical ethics; it seems to imply some objective foundation to our ethical judgements; it squares with our experience of making ethical decisions; it shows something of the nature of moral arguments; and, finally, it has implications for teaching medicine and ethics.

  9. Methods of ultimate carbonaceous BOD determination

    USGS Publications Warehouse

    Stamer, J.K.; McKenzie, S.W.; Cherry, R.N.

    1979-01-01

    Studies were conducted to provide an accurate and practical technique for determining the concentration of ultimate carbonaceous biochemical oxygen demand and the rate at which this demand is exerted. The three methods evaluated were carbon derived, nitrification adjusted, and nitrification inhibited. The studies indicate that comparable concentrations and reaction rates can be determined from either non-nitrified samples using no chemical nitrifying inhibitor, or from partially nitrified samples using the chemical inhibitors, 1-allyl-2 thiourea or nitrapyrin, and that the combined use of time-series analysis and Lee's graphical method provide a reliable and accurate technique for determining ultimate biochemical oxygen demand concentration and reaction rate in 5 to 7 days.

  10. Ultimate computing. Biomolecular consciousness and nano Technology

    SciTech Connect

    Hameroff, S.R.

    1987-01-01

    The book advances the premise that the cytoskeleton is the cell's nervous system, the biological controller/computer. If indeed cytoskeletal dynamics in the nanoscale (billionth meter, billionth second) are the texture of intracellular information processing, emerging ''NanoTechnologies'' (scanning tunneling microscopy, Feynman machines, von Neumann replicators, etc.) should enable direct monitoring, decoding and interfacing between biological and technological information devices. This in turn could result in important biomedical applications and perhaps a merger of mind and machine: Ultimate Computing.

  11. Ultimate gradient in solid-state accelerators

    SciTech Connect

    Whittum, D.H.

    1999-07-01

    We recall the motivation for research in high-gradient acceleration and the problems posed by a compact collider. We summarize the phenomena known to appear in operation of a solid-state structure with large fields, and research relevant to the question of the ultimate gradient. We take note of new concepts, and examine one in detail, a miniature particle accelerator based on an active millimeter-wave circuit and parallel particle beams. {copyright} {ital 1999 American Institute of Physics.}

  12. Ultimate gradient in solid-state accelerators

    SciTech Connect

    Whittum, D.H.

    1998-08-01

    The authors recall the motivation for research in high-gradient acceleration and the problems posed by a compact collider. They summarize the phenomena known to appear in operation of a solid-state structure with large fields, and research relevant to the question of the ultimate gradient. They take note of new concepts, and examine one in detail, a miniature particle accelerator based on an active millimeter-wave circuit and parallel particle beams.

  13. Ultimate gradient in solid-state accelerators

    SciTech Connect

    Whittum, David H.

    1999-07-12

    We recall the motivation for research in high-gradient acceleration and the problems posed by a compact collider. We summarize the phenomena known to appear in operation of a solid-state structure with large fields, and research relevant to the question of the ultimate gradient. We take note of new concepts, and examine one in detail, a miniature particle accelerator based on an active millimeter-wave circuit and parallel particle beams.

  14. The ultimate disposition of depleted uranium

    SciTech Connect

    Lemons, T.R.

    1991-12-31

    Depleted uranium (DU) is produced as a by-product of the uranium enrichment process. Over 340,000 MTU of DU in the form of UF{sub 6} have been accumulated at the US government gaseous diffusion plants and the stockpile continues to grow. An overview of issues and objectives associated with the inventory management and the ultimate disposition of this material is presented.

  15. Is space the ultimate high ground?

    NASA Astrophysics Data System (ADS)

    Meyer, Gregory J.; Stallings, Francis P.

    2011-06-01

    Military experts often refer to space as the ultimate high ground under the premise that placing systems in orbit provides advantages consistent with the military doctrine of high ground. Although space provides the ultimate "observation post", it has none of the other advantages traditionally associated with high ground. Army Field Manual (FM) 34-130 states the other advantages of holding key terrain: commanding avenues of approach, overcoming obstacles, and affording cover and concealment as additional benefits of high ground. Yet systems in orbit incur none of these additional advantages. Finally, international restrictions and reciprocity concerns limit the employment of weapons in space nullifying many of the unique capability advantages that would otherwise support the "high ground" aspect of space. As the ultimate observation post, satellites provide a large quantity of vital data to military decision makers. This massive amount of data needs to have as much context as possible to convert this data to useful knowledge. To use space assets optimally, the military needs to learn from the past and make space and cyber products distributed and tactical. It is absolutely essential to distribute the right information to the lowest level (tactical elements) of the organization or the "boots on the ground" in a timely manner.

  16. The ultimate disposition of depleted uranium

    SciTech Connect

    Not Available

    1990-12-01

    Significant amounts of the depleted uranium (DU) created by past uranium enrichment activities have been sold, disposed of commercially, or utilized by defense programs. In recent years, however, the demand for DU has become quite small compared to quantities available, and within the US Department of Energy (DOE) there is concern for any risks and/or cost liabilities that might be associated with the ever-growing inventory of this material. As a result, Martin Marietta Energy Systems, Inc. (Energy Systems), was asked to review options and to develop a comprehensive plan for inventory management and the ultimate disposition of DU accumulated at the gaseous diffusion plants (GDPs). An Energy Systems task team, under the chairmanship of T. R. Lemons, was formed in late 1989 to provide advice and guidance for this task. This report reviews options and recommends actions and objectives in the management of working inventories of partially depleted feed (PDF) materials and for the ultimate disposition of fully depleted uranium (FDU). Actions that should be considered are as follows. (1) Inspect UF{sub 6} cylinders on a semiannual basis. (2) Upgrade cylinder maintenance and storage yards. (3) Convert FDU to U{sub 3}O{sub 8} for long-term storage or disposal. This will include provisions for partial recovery of costs to offset those associated with DU inventory management and the ultimate disposal of FDU. Another recommendation is to drop the term tails'' in favor of depleted uranium'' or DU'' because the tails'' label implies that it is waste.'' 13 refs.

  17. Ultimate biodegradation of dialkyl phthalate ester plasticizers

    SciTech Connect

    Lee, C.L.; Sinko, C.J.; Winkelmann, D.A.; Peterson, D.R.; Parkerton, T.F.

    1995-12-31

    Phthalate Esters (PEs) are primarily used as plasticizers in the polymer industry to impart the desired degree of flexibility to plastic products. The single isomer, di-2-ethylhexyl phthalate (DEHP) is the most common plasticizer. However, other commercially important PE plasticizers possess branched alkyl chains of a mixed isomeric nature. The purpose of this study was to compare the ultimate biodegradability of mixed isomer PEs dihexyl (DHP), diisoheptyl (DIHP), diisononyl (DINP), diisodecyl (DIDP), and diisoundecyl (DIUP) phthalate to DEHP using the standardized OECD test (301 F) which is based on mannometric respirometry. Ultimate biodegradation results after 28 days under unacclimated conditions at 25 C were as follows: DHP (80 {+-} 10%), DIHP (82 {+-} 13%), DEHP (63 {+-} 18%), DINP (70 {+-} 11%), DIDP (67 {+-} 13%), DUP (57 {+-} 14%). These data confirm the readily biodegradable nature of DEHP and mixed isomer PEs reported in previous studies and provide additional data to contradict the misperception that PEs are environmentally persistent. The influence of alkyl chain structure on the rate and extent of biodegradation observed in this and other biodegradation studies are discussed.

  18. Therapeutic vaccines: the ultimate personalized therapy?

    PubMed

    Gulley, James L

    2013-01-01

    Personalized therapy is directed at obtaining maximal therapeutic effect on diseased tissue with minimal off-target side effects. Many classes of therapeutics have attempted to reach this ideal, only to fall well short. Therapeutic vaccines represent a novel class of therapies that can induce a dynamic immune response that, in theory, can continue to adapt and expand following initiation of vaccination. This adaptability, through epitope spreading or antigen cascade, can continuously refine a therapeutic immune response, making it more relevant to the patient's tumor. This active, dynamic, iterative process can continue long after the vaccine course has been completed. Recent clinical trials have provided further insight into the clinical activity of therapeutic vaccines, and offer guidance on clinical expectations following vaccine. The ongoing active sculpting of the immune response, along with the lack of significant side effects, uniquely positions therapeutic vaccines as perhaps the ultimate in personalized therapy.

  19. Transcending matter: physics and ultimate meaning.

    PubMed

    Paulson, Steve; Frank, Adam; Kaiser, David; Maudlin, Tim; Natarajan, Priyamvada

    2015-12-01

    From the discovery of new galaxies and nearly undetectable dark energy to the quantum entanglement of particles across the universe, new findings in physics naturally elicit a sense of awe and wonder. For the founders of modern physics-from Einstein and Bohr to Heisenberg, Pauli, and Bohm-a fascination with deeper questions of meaning and ultimate reality led some of them to explore esoteric traditions and metaphysics. More recently, however, physicists have largely shunned such philosophical and spiritual associations. What can contemporary physics offer us in the quest to understand our place in the universe? Has physics in some ways become a religion unto itself that rejects the search for existential meaning? Discussion of these and related questions is presented in this paper.

  20. Transcending matter: physics and ultimate meaning.

    PubMed

    Paulson, Steve; Frank, Adam; Kaiser, David; Maudlin, Tim; Natarajan, Priyamvada

    2015-12-01

    From the discovery of new galaxies and nearly undetectable dark energy to the quantum entanglement of particles across the universe, new findings in physics naturally elicit a sense of awe and wonder. For the founders of modern physics-from Einstein and Bohr to Heisenberg, Pauli, and Bohm-a fascination with deeper questions of meaning and ultimate reality led some of them to explore esoteric traditions and metaphysics. More recently, however, physicists have largely shunned such philosophical and spiritual associations. What can contemporary physics offer us in the quest to understand our place in the universe? Has physics in some ways become a religion unto itself that rejects the search for existential meaning? Discussion of these and related questions is presented in this paper. PMID:26359938

  1. Ultimately short ballistic vertical graphene Josephson junctions

    PubMed Central

    Lee, Gil-Ho; Kim, Sol; Jhi, Seung-Hoon; Lee, Hu-Jong

    2015-01-01

    Much efforts have been made for the realization of hybrid Josephson junctions incorporating various materials for the fundamental studies of exotic physical phenomena as well as the applications to superconducting quantum devices. Nonetheless, the efforts have been hindered by the diffusive nature of the conducting channels and interfaces. To overcome the obstacles, we vertically sandwiched a cleaved graphene monoatomic layer as the normal-conducting spacer between superconducting electrodes. The atomically thin single-crystalline graphene layer serves as an ultimately short conducting channel, with highly transparent interfaces with superconductors. In particular, we show the strong Josephson coupling reaching the theoretical limit, the convex-shaped temperature dependence of the Josephson critical current and the exceptionally skewed phase dependence of the Josephson current; all demonstrate the bona fide short and ballistic Josephson nature. This vertical stacking scheme for extremely thin transparent spacers would open a new pathway for exploring the exotic coherence phenomena occurring on an atomic scale. PMID:25635386

  2. Ultimately short ballistic vertical graphene Josephson junctions.

    PubMed

    Lee, Gil-Ho; Kim, Sol; Jhi, Seung-Hoon; Lee, Hu-Jong

    2015-01-01

    Much efforts have been made for the realization of hybrid Josephson junctions incorporating various materials for the fundamental studies of exotic physical phenomena as well as the applications to superconducting quantum devices. Nonetheless, the efforts have been hindered by the diffusive nature of the conducting channels and interfaces. To overcome the obstacles, we vertically sandwiched a cleaved graphene monoatomic layer as the normal-conducting spacer between superconducting electrodes. The atomically thin single-crystalline graphene layer serves as an ultimately short conducting channel, with highly transparent interfaces with superconductors. In particular, we show the strong Josephson coupling reaching the theoretical limit, the convex-shaped temperature dependence of the Josephson critical current and the exceptionally skewed phase dependence of the Josephson current; all demonstrate the bona fide short and ballistic Josephson nature. This vertical stacking scheme for extremely thin transparent spacers would open a new pathway for exploring the exotic coherence phenomena occurring on an atomic scale. PMID:25635386

  3. The Phenix ultimate natural convection test

    SciTech Connect

    Gauthe, P.; Pialla, D.; Tenchine, D.; Vasile, A.; Rochwerger, D.

    2012-07-01

    The French sodium cooled fast reactor Phenix was shut down in 2009 after 35 years of operation. Before decommissioning, a final set of tests were performed by the CEA during 9 months. Several topics were involved such as thermal hydraulics, core physics and fuel behaviour. Among these ultimate experiments, two thermal hydraulic tests were performed: an asymmetrical test consisting in a trip of one secondary pump and a natural convection test in the primary circuit. Recognizing the unique opportunity offered by these Phenix ultimate tests, IAEA decided in 2007 to launch a Coordinated Research Project (CRP) devoted to benchmarking analyses with system codes on the Phenix natural convection test. One objective of the natural convection test in Phenix reactor is the assessment of the CATHARE system code for safety studies on future and advanced sodium cooled fast reactors. The aim of this paper is to describe this test, which was performed on June 22-23, 2009, and the associated benchmark specifications for the CRP work. The paper reminds briefly the Phenix reactor with the main physical parameters and the instrumentation used during the natural convection test. After that, the test scenario is described: - initial state at a power of 120 MWth, - test beginning resulting from a manual dry out of the two steam generators, - manual scram, - manual trip on the three primary pumps without back-up by pony motors, - setting and development of natural convection in the primary circuit, in a first phase without significant heat sink in the secondary circuits and in a second phase with significant heat sink in the secondary circuits, by opening the casing of steam generators to create an efficient heat sink, by air natural circulation in the steam generators casing. The benchmark case ends after this second phase, which corresponds to the experimental test duration of nearly 7 hours. The paper presents also the benchmark specifications data supplied by the CEA to all

  4. Toward the ultimate synthesis/recognition system.

    PubMed Central

    Furui, S

    1995-01-01

    This paper predicts speech synthesis, speech recognition, and speaker recognition technology for the year 2001, and it describes the most important research problems to be solved in order to arrive at these ultimate synthesis and recognition systems. The problems for speech synthesis include natural and intelligible voice production, prosody control based on meaning, capability of controlling synthesized voice quality and choosing individual speaking style, multilingual and multidialectal synthesis, choice of application-oriented speaking styles, capability of adding emotion, and synthesis from concepts. The problems for speech recognition include robust recognition against speech variations, adaptation/normalization to variations due to environmental conditions and speakers, automatic knowledge acquisition for acoustic and linguistic modeling, spontaneous speech recognition, naturalness and ease of human-machine interaction, and recognition of emotion. The problems for speaker recognition are similar to those for speech recognition. The research topics related to all these techniques include the use of articulatory and perceptual constraints and evaluation methods for measuring the quality of technology and systems. Images Fig. 3 PMID:7479723

  5. Olympus: The Ultimate Summit for Science

    NASA Technical Reports Server (NTRS)

    Kelly, Darrell; Holt, Stephen (Technical Monitor)

    2000-01-01

    High above the world-class observatories that dot Hawaii's dormant Mauna Kea volcano, floating farther yet over the hostile and nearly inaccessible peaks of Mt. Everest, lies a summit waiting to be conquered. Here above the clouds and city lights and over 99.7% of the atmosphere is a platform on the edge of space, home to a broad range of astronomy and physics experiments. Today, balloons are lifting experiments longer, higher and more inexpensively than ever before, and returning them safely to Earth for reuse. Week-long flights at altitudes of approximately 35 kilometers carrying payloads in excess of several tons are the norm. NASA now plans to extend this platform and create a new generation of balloons capable of staying afloat with such cargo for 100 days and ultimately 1,000 days. What do some scientists hope to accomplish with 100 or even 1,000 days at the edge of space? To name but a few proposals on the table: Jupiter-size planet searches, large-aperture solar astronomy, large-aperture infrared astronomy, cosmic-ray investigations, long-duration Earth science missions, and hard x-ray imaging experiments. Olympus defines a new era in scientific ballooning. Advances in material science and trajectory control are enabling revolutionary capabilities. Very large scientific payloads can now be reliably launched and retrieved for reflight at a range of altitudes. Balloon flight still remains a fraction of the cost of a rocket launch. The ultra long duration balloon, with its 100-day maiden flight planned for 2001, provides a long-term facility in a near-space environment for many types of science. This is a stratospheric mountaintop well worth the climb.

  6. Bilabiate Flowers: The Ultimate Response to Bees?

    PubMed Central

    Westerkamp, Christian; Claßen-Bockhoff, Regine

    2007-01-01

    pressure towards the bilabiate syndrome. As bees are very inventive, however, bilabiate constructions will not represent the ultimate response to bees. PMID:17652341

  7. Do postsurgical interventions optimize ultimate scar cosmesis.

    PubMed

    Viera, M H; Amini, S; Konda, S; Berman, B

    2009-06-01

    Keloids and other scars are different manifestations of the normal wound healing process. If located in visible areas, scars may have a psychological impact that could affect the quality of life of the scar-bearing population. Good preoperatory planning including hiding incisions in natural anatomical landmarks or placing them parallel to relaxed skin tension lines are among the techniques used to improve the cosmesis of scars. Once a prominent or noticeable scar has developed, multiple therapeutic modalities can be applied including surgical excision, although high recurrence rates precludes its use as monotherapy. Several advanced surgical correction techniques including Z-plasty and W-plasty may be useful in repositioning scars. Other modalities that have been reported to improve scar cosmesis include cryosurgery, radiotherapy, lasers, and skin substitute grafts. Adjuvant postsurgical treatment modalities have reduced dramatically the recurrence rates associated with the removal of the scar. In this review of the literature the authors discuss evidence based data related to the abovementioned modalities and other topical and intralesional therapies including occlusion, compression, silicone, corticosteroids, interferons, imiquimod, resiquimod, tacrolimus, 5-fluorouracil, retinoids, as well as the role of several over-the-counter agents such as onion extract, vitamin E and the combination of hydrocortisone, vitamin E and silicone. Finally, they address newer modalities including vascular endothelial growth factor inhibitor, transforming growth factor-3, interleukin-10, mannose-6-phosphate, UVA-1, narrowband UVB, intense pulsed light and photodynamic therapy. Ultimately, the decision of choosing the most appropriate postexcisional management treatment should be taken by physicians on a case-by-case basis in order to obtain the best cosmetically acceptable results. PMID:19528906

  8. "Got Disc?" The "Ultimate" Experience in Physical Education

    ERIC Educational Resources Information Center

    Johnson, Tyler G.; Darst, Paul W.; Brusseau, Timothy A.

    2006-01-01

    A quality physical education program is one in which students are exposed to and can participate in a variety of sports and activities. One activity that is increasing in popularity in and outside of physical education is the game of "Ultimate." Opportunities to play Ultimate are increasing rapidly in intramural programs and community and…

  9. Proximate and ultimate causes of punishment and strong reciprocity.

    PubMed

    Barclay, Pat

    2012-02-01

    While admirable, Guala's discussion of reciprocity suffers from a confusion between proximate causes (psychological mechanisms triggering behaviour) and ultimate causes (evolved function of those psychological mechanisms). Because much work on "strong reciprocity" commits this error, I clarify the difference between proximate and ultimate causes of cooperation and punishment. I also caution against hasty rejections of "wide readings" of experimental evidence.

  10. Ultimate Limits to Resource Efficiency in Photonic Communication

    NASA Technical Reports Server (NTRS)

    Erkmen, Baris I.; Moision, Bruce E.; Dolinar, Sam

    2013-01-01

    We review resource-efficiency metrics for transferring classical information with photon, present an overview of the ultimate limits to photon and dimensional efficiency permitted by quantum mechanics, as well as that acheived with structured transmitter-receiver pairs.

  11. INFORMATION THEORY: 'Ultimate PC' Would Be a Hot Little Number.

    PubMed

    Seife, C

    2000-09-01

    A physicist has used the laws of thermodynamics, information, relativity, and quantum mechanics to figure out the ultimate physical limits on the speed of a computer. His calculations show that, in principle, a kilogram of matter in a liter-sized container could be an "ultimate laptop" more than a trillion trillion trillion times as powerful as today's fastest supercomputer--if it could be turned into a black hole. PMID:17839510

  12. Incidence and Descriptive Epidemiology of Injuries to College Ultimate Players

    PubMed Central

    Swedler, David I.; Nuwer, Jamie M.; Nazarov, Anna; Huo, Samantha C.; Malevanchik, Lev

    2015-01-01

    Context: The burden of injuries to college ultimate players has never been fully described. Objective: To quantify the injury rate in ultimate players and describe the diagnoses, anatomic locations, and mechanisms of injuries. Design: Descriptive epidemiology study. Setting: College ultimate teams in the United States during the 2012 season. Main Outcome Measure(s): Initial injury rate per 1000 athlete-exposures. Results: The initial injury rate in college ultimate players was 12.64 per 1000 athlete-exposures; the rate did not differ between men and women (P = .5). Bivariate analysis indicated that injuries occurred twice as often during games as during practices, men were more likely than women to be injured when laying out for the disc, and men were more likely to incur strains and sprains than women. Conclusions: Injury patterns to college ultimate players were similar to those for athletes in other National Collegiate Athletic Association sports. This is the first study to systematically describe injuries to ultimate players. PMID:25384003

  13. Pre-slaughter stress arising from on-farm handling and its interactions with electrical stimulation on tenderness of lambs.

    PubMed

    Devine, C E; Lowe, T E; Wells, R W; Edwards, N J; Edwards, J E Hocking; Starbuck, T J; Speck, P A

    2006-06-01

    The effect of electrical stimulation of lamb carcasses (n=269) or its absence (n=257) on shear force of m. longissimus thoracis et lumborum (LT) was monitored during ageing in pasture-fed merino lambs (n=526). The lambs were slaughtered on four different days allowing durations of between one to 10 days of recovery from pre-slaughter handling (yarding, weighing and crutching) that affected ultimate pH (pH(u)). The right LT was removed 20-40min post-slaughter, tightly-wrapped in cling film (prevents the muscle cross-section increasing and thus minimising shortening) and rapidly cooled to 15°C to enter rigor mortis and age. At 0, 4, 24 and 72h post-slaughter, pH measurements and samples for shear force measurement were taken. Pre-slaughter handling had a significant negative effect on pH(u) and several days recovery were required for pH(u) to reach values associated with optimal meat quality as reflected by pH(u). Lambs with one and three days recovery (no significant difference between them) had a pH(u)>5.7 in 50% of the muscles and 19.4%>pH(u) 5.8. Whereas, in lambs with 8-10 days recovery (no significant difference between them), only 8% had a pH(u)>5.7 and 3.1%>pH(u) 5.8. Within each slaughter day electrically stimulated lambs were always more tender than non-stimulated lambs. For non-stimulated muscles at 72h, shear force values >40N occurred for 11.2% of the muscles: for electrically stimulated muscles at 72h, shear force values >40N occurred for 1.9% of the muscles. The rates of tenderisation were slower for intermediate pH(u) values resulting in higher shear force values at all ageing durations. With ageing at 72h for intermediate pH(u), non-stimulated muscles (n=38) 17.64% were >40N and for stimulated muscles (n=34), 7.9% were >40N. PMID:22062302

  14. Centaur Standard Shroud (CSS) static ultimate load structural tests

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A series of tests were conducted on the jettisonable metallic shroud used on the Titan/Centaur launch vehicle to verify its structural capabilities and to evaluate its structural interaction with the Centaur stage. A flight configured shroud and the interfacing Titan/Centaur structural assemblies were subjected to tests consisting of combinations of applied axial and shear loads to design ultimate values, including a set of tests on thermal conditions and two dynamic response tests to verify the analytical stiffness model. The strength capabilities were demonstrated at ultimate (125 percent of design limit) loads. It was also verified that the spring rate of the flight configured shroud-to-Centaur forward structural deflections of the specimen became nonlinear, as expected, above limit load values. This test series qualification program verified that the Titan/Centaur shroud and the Centaur and Titan interface components are qualified structurally at design ultimate loads.

  15. Analytical determination of the ultimate strength of sandwich beams

    NASA Astrophysics Data System (ADS)

    Theotokoglou, Efstathios E.

    1996-09-01

    An analytical determination of the ultimate strength of a typical GRP/PVC sandwich beam has been performed. These beams represent common building practise in marine applications. Equations describing the behaviour of a sandwich panel under beam loading and various failure modes have been developed. The method has been applied to predict the ultimate load for a simple supported sandwich beam. The critical loads have been compared with those from the experimental investigation of a typical bulkhead-to-hull GRP/PVC sandwich T-joint under pull out forces.

  16. Balancing act: the ultimate balance nutrition consulting center.

    PubMed

    Engle, L

    1998-11-01

    Nutritional issues often complicate health care but are very important in HIV treatment where diet can play a strong role in drug absorption and effectiveness. A Canadian company has started a for-fee nutritional counseling service called Ultimate Balance. The nutritionists at Ultimate Balance require medical disclosure and extensive telephone interviews with patients, and also review patients' cases and medications. The nutritional guidance provided is controversial, because it is funded by a company that produces nutritional supplements, and counselors sometimes recommend those supplements. A personal experience with the nutritional counseling service is described. Contact information is provided. PMID:11365979

  17. Ultimate Success Rates on National Board Examinations: A Research Brief.

    ERIC Educational Resources Information Center

    Gross, Leon J.; Wallis, Norman E.; Present, Richard K.

    1999-01-01

    A study investigated the percentage of optometry students successfully completing the four-component National Board of Examiners in Optometry examination at graduation between 1995 to 1997. Ultimate pass rates for all four components ranged from 87.0% to 90.9%. Results are discussed in relation to the 1993 test-sequence expansion and to the number…

  18. The Ultimate Sampling Dilemma in Experience-Based Decision Making

    ERIC Educational Resources Information Center

    Fiedler, Klaus

    2008-01-01

    Computer simulations and 2 experiments demonstrate the ultimate sampling dilemma, which constitutes a serious obstacle to inductive inferences in a probabilistic world. Participants were asked to take the role of a manager who is to make purchasing decisions based on positive versus negative feedback about 3 providers in 2 different product…

  19. 37. ALTERNATE DESIGN, SIMILAR TO THAT ULTIMATELY SELECTED, BUT USING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. ALTERNATE DESIGN, SIMILAR TO THAT ULTIMATELY SELECTED, BUT USING STEPPED TOWERS, AND WITH PYLONS CAPPED BY LANTERNS Pen-and-ink drawing by project architect Alfred Eichler, ca. 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  20. 78 FR 40625 - Reporting Ultimate Payees of Political Committee Disbursements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ... 11 CFR Part 104 Reporting Ultimate Payees of Political Committee Disbursements AGENCY: Federal... clarifying its interpretation of the regulatory requirement that political committees ] report the full name... purpose of such payments, in three situations: A political committee reimburses an individual who...

  1. 29 CFR 18.704 - Opinion on ultimate issue.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Opinion on ultimate issue. 18.704 Section 18.704 Labor Office of the Secretary of Labor RULES OF PRACTICE AND PROCEDURE FOR ADMINISTRATIVE HEARINGS BEFORE THE OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Opinions and Expert Testimony § 18.704 Opinion...

  2. Pork Quality Traits According to Postmortem pH and Temperature in Berkshire.

    PubMed

    Kim, Tae Wan; Kim, Chul Wook; Yang, Mi Ra; No, Gun Ryoung; Kim, Sam Woong; Kim, Il-Suk

    2016-01-01

    This study was performed to investigate the role of pH and temperature postmortem, and to demonstrate the importance of these factors in determining meat quality. Postmortem pH 45min (pH at 45 min postmortem or initial pH) via analysis of Pearson's correlation showed high positive correlation with pH change pH c24 (pH change from pH 45min to pH 24h postmortem). However, postmortem pH after 24 h (pH 24h or ultimate pH) had a high negative correlation with pH change, pH c24 , CIE L*, and protein content. Initial temperature postmortem (T 1h ) was positively associated with a change in temperature from 45 min to 24 h postmortem (T c24 ) and cooking loss, but negatively correlated with water holding capacity. Temperature at 24 h postmortem (T 24h ) was negatively associated with T c24 . Collectively, these results indicate that higher initial pH was associated with higher pH c24 , T 1h , and T c24 . However, higher initial pH was associated with a reduction in carcass weight, backfat thickness, CIE a* and b*, water holding capacity, collagen and fat content, drip loss, and cooking loss as well as decreased shear force. In contrast, CIE a* and b*, drip loss, cooking loss, and shear force in higher ultimate pH was showed by a similar pattern to higher initial pH, whereas pH c24 , carcass weight, backfat thickness, water holding capacity, fat content, moisture content, protein content, T 1h , T 24h , and T c24 were exhibited by completely differential patterns (p<0.05). Therefore, we suggest that initial pH, ultimate pH, and temperatures postmortem are important factors in determining the meat quality of pork. PMID:27499661

  3. Ultimate classical communication rates of quantum optical channels

    NASA Astrophysics Data System (ADS)

    Giovannetti, V.; García-Patrón, R.; Cerf, N. J.; Holevo, A. S.

    2014-10-01

    Optical channels, such as fibres or free-space links, are ubiquitous in today's telecommunication networks. They rely on the electromagnetic field associated with photons to carry information from one point to another in space. A complete physical model of these channels must necessarily take quantum effects into account to determine their ultimate performances. Single-mode, phase-insensitive bosonic Gaussian channels have been extensively studied over past decades, given their importance for practical applications. In spite of this, a long-standing unsolved conjecture on the optimality of Gaussian encodings has prevented finding their classical communication capacity. Here, this conjecture is solved by proving that the vacuum state achieves the minimum output entropy of these channels. This establishes the ultimate achievable bit rate under an energy constraint, as well as the long awaited proof that the single-letter classical capacity of these channels is additive.

  4. Ultimate Heat Sink Cooling Pond and Spray Pond Analysis Models.

    1999-05-02

    Version 00 Three programs model performance of an ultimate heat sink cooling pond. National Weather Service data is read and analyzed to predict periods of lowest cooling performance and highest evaporative loss. The data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. Five programs model performance of an ultimate heat sink spray pond. The cooling performance, evaporative water loss, and drift water loss as a function ofmore » windspeed are estimated for a spray field. These estimates are used in conjunction with National Weather Service data to predict periods of lowest cooling performance and highest evaporative loss. This data is compared to local site data for significant differences. Then the maximum pond temperature is predicted.« less

  5. The effect of electrical stimulation on post mortem myofibrillar protein degradation and small heat shock protein kinetics in bull beef.

    PubMed

    Contreras-Castillo, C J; Lomiwes, D; Wu, G; Frost, D; Farouk, M M

    2016-03-01

    This study aimed to determine the effect of electrical stimulation and ultimate pH (pHu) on shear force, myofibrillar protein degradation and small heat shock protein (sHSP) concentrations in M. longissimus lumborum (LL). The LL from both sides of carcasses (n=15) was excised with low voltage electrical stimulation (ES) applied to an LL muscle from one side, while the opposing LL muscle was not stimulated (NS). Muscles were categorised into low (pHu<5.8), intermediate (5.8≤pHu<6.2) and high pHu (pHu≥6.2) and aged for up to 28days post mortem at -1.5°C. High pHu meat tenderised faster which corresponded with the faster degradation of titin and desmin in this group compared with low and intermediate pHu meat. Electrical stimulation significantly affected the variable levels of αβ-crystallin and HSP20 with higher concentrations of these sHSP in ES muscles at later ageing timepoints compared with NS muscles.

  6. Silicon wafer-based tandem cells: The ultimate photovoltaic solution?

    NASA Astrophysics Data System (ADS)

    Green, Martin A.

    2014-03-01

    Recent large price reductions with wafer-based cells have increased the difficulty of dislodging silicon solar cell technology from its dominant market position. With market leaders expected to be manufacturing modules above 16% efficiency at 0.36/Watt by 2017, even the cost per unit area (60-70/m2) will be difficult for any thin-film photovoltaic technology to significantly undercut. This may make dislodgement likely only by appreciably higher energy conversion efficiency approaches. A silicon wafer-based cell able to capitalize on on-going cost reductions within the mainstream industry, but with an appreciably higher than present efficiency, might therefore provide the ultimate PV solution. With average selling prices of 156 mm quasi-square monocrystalline Si photovoltaic wafers recently approaching 1 (per wafer), wafers now provide clean, low cost templates for overgrowth of thin, wider bandgap high performance cells, nearly doubling silicon's ultimate efficiency potential. The range of possible Si-based tandem approaches is reviewed together with recent results and ultimate prospects.

  7. Ultimate concerns in late modernity: Archer, Bourdieu and reflexivity.

    PubMed

    Farrugia, David; Woodman, Dan

    2015-12-01

    Through a critique of Margaret Archer's theory of reflexivity, this paper explores the theoretical contribution of a Bourdieusian sociology of the subject for understanding social change. Archer's theory of reflexivity holds that conscious 'internal conversations' are the motor of society, central both to human subjectivity and to the 'reflexive imperative' of late modernity. This is established through critiques of Bourdieu, who is held to erase creativity and meaningful personal investments from subjectivity, and late modernity is depicted as a time when a 'situational logic of opportunity' renders embodied dispositions and the reproduction of symbolic advantages obsolete. Maintaining Archer's focus on 'ultimate concerns' in a context of social change, this paper argues that her theory of reflexivity is established through a narrow misreading and rejection of Bourdieu's work, which ultimately creates problems for her own approach. Archer's rejection of any pre-reflexive dimensions to subjectivity and social action leaves her unable to sociologically explain the genesis of 'ultimate concerns', and creates an empirically dubious narrative of the consequences of social change. Through a focus on Archer's concept of 'fractured reflexivity', the paper explores the theoretical necessity of habitus and illusio for understanding the social changes that Archer is grappling with. In late modernity, reflexivity is valorized just as the conditions for its successful operation are increasingly foreclosed, creating 'fractured reflexivity' emblematic of the complex contemporary interaction between habitus, illusio, and accelerating social change.

  8. Ultimate concerns in late modernity: Archer, Bourdieu and reflexivity.

    PubMed

    Farrugia, David; Woodman, Dan

    2015-12-01

    Through a critique of Margaret Archer's theory of reflexivity, this paper explores the theoretical contribution of a Bourdieusian sociology of the subject for understanding social change. Archer's theory of reflexivity holds that conscious 'internal conversations' are the motor of society, central both to human subjectivity and to the 'reflexive imperative' of late modernity. This is established through critiques of Bourdieu, who is held to erase creativity and meaningful personal investments from subjectivity, and late modernity is depicted as a time when a 'situational logic of opportunity' renders embodied dispositions and the reproduction of symbolic advantages obsolete. Maintaining Archer's focus on 'ultimate concerns' in a context of social change, this paper argues that her theory of reflexivity is established through a narrow misreading and rejection of Bourdieu's work, which ultimately creates problems for her own approach. Archer's rejection of any pre-reflexive dimensions to subjectivity and social action leaves her unable to sociologically explain the genesis of 'ultimate concerns', and creates an empirically dubious narrative of the consequences of social change. Through a focus on Archer's concept of 'fractured reflexivity', the paper explores the theoretical necessity of habitus and illusio for understanding the social changes that Archer is grappling with. In late modernity, reflexivity is valorized just as the conditions for its successful operation are increasingly foreclosed, creating 'fractured reflexivity' emblematic of the complex contemporary interaction between habitus, illusio, and accelerating social change. PMID:26434655

  9. Rapid population growth and environmental degradation: ultimate versus proximate factors.

    PubMed

    Shaw, R P

    1989-01-01

    This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on

  10. Rapid population growth and environmental degradation: ultimate versus proximate factors.

    PubMed

    Shaw, R P

    1989-01-01

    This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on

  11. What is the Ultimate Goal in Acid-Base Regulation?

    ERIC Educational Resources Information Center

    Balakrishnan, Selvakumar; Gopalakrishnan, Maya; Alagesan, Murali; Prakash, E. Sankaranarayanan

    2007-01-01

    It is common to see chapters on acid-base physiology state that the goal of acid-base regulatory mechanisms is to maintain the pH of arterial plasma and not arterial PCO [subscript 2] (Pa[subscript CO[subscript 2

  12. Models of proximate and ultimate causation in psychology.

    PubMed

    Alessi, G

    1992-11-01

    B. F. Skinner saw behavior as a product of three levels of evolution. J. R. Kantor and Gregory Bateson noted similar relations. This article describes and applies basic evolutionary concepts to each level: (a) phylogenic, (b) ontogenic, and (c) cultural evolution. Each level is analyzed in terms of (a) units of selection, (b) variety of units required for the selection process, (c) selection pressures, (d) interactions among levels, and (e) implications for understanding and predicting behavior. Distinguishing between models of proximate and ultimate causation, as in biology, may help clarify research problems posed by, and facilitate better communication among, psychologists. PMID:1482003

  13. APA's model law: protecting the patient's ultimate interests.

    PubMed

    Dunham, A C

    1985-09-01

    As a mental health advocate and the parent of a chronic mentally ill son, the author argues for adoption of the provisions in APA's model law on civil commitment. He believes that a shift in mental health law from absolute protection of civil liberty to an emphasis on the ultimate good for an individual will dramatically improve the lives of the seriously mentally ill by ending the deterioration that they currently must experience to receive treatment. The author also discusses the merits of a proposal that would expedite treatment for patients who repeatedly require emergency care.

  14. Some Physics Constraints on Ultimate Achievement in Track and Field

    SciTech Connect

    Frohlich, Cliff

    2009-02-06

    World records in track and field have improved remarkably throughout the last 100 years; however, in several events physics places quite strict limitations on ultimate performance. For example, analysis suggests that records in broad jump and pole vault have approached their optimum possible values. Physical constraints are more subtle for events such as javelin, high jump, and the distance races, and thus there may be opportunities for “breakthroughs” in current records. Considering that there is enormous cultural interest and economic expenditure on sports, for most events the level of scientific analysis isn’t very high. This presents a research opportunity for fans who are engineers or physicists.

  15. The insanity defense: asking and answering the ultimate question.

    PubMed

    Ciccone, J R; Clements, C

    1987-01-01

    The authors address the main questions in the insanity defense debate: Should it be abolished? Should psychiatrists participate as expert witnesses? Is the profession damaged by such testimony? Is there a logical leap between providing psychiatric findings and providing an opinion to the ultimate question? Because the free will/determinism model underlying the current insanity defense positions can be used to argue either side of the debate, it does not supply any rational answers. The authors reframe the discussion, using a systems approach, and suggest answers to these questions that are in line with the clinical realities and on a firmer philosophic ground.

  16. Models of proximate and ultimate causation in psychology.

    PubMed

    Alessi, G

    1992-11-01

    B. F. Skinner saw behavior as a product of three levels of evolution. J. R. Kantor and Gregory Bateson noted similar relations. This article describes and applies basic evolutionary concepts to each level: (a) phylogenic, (b) ontogenic, and (c) cultural evolution. Each level is analyzed in terms of (a) units of selection, (b) variety of units required for the selection process, (c) selection pressures, (d) interactions among levels, and (e) implications for understanding and predicting behavior. Distinguishing between models of proximate and ultimate causation, as in biology, may help clarify research problems posed by, and facilitate better communication among, psychologists.

  17. The Ultimate Challenge: Prove B. F. Skinner Wrong

    PubMed Central

    Chance, Paul

    2007-01-01

    For much of his career, B. F. Skinner displayed the optimism that is often attributed to behaviorists. With time, however, he became less and less sanguine about the power of behavior science to solve the major problems facing humanity. Near the end of his life he concluded that a fair consideration of principles revealed by the scientific analysis of behavior leads to pessimism about our species. In this article I discuss the case for Skinner's pessimism and suggest that the ultimate challenge for behavior analysts today is to prove Skinner wrong. PMID:22478494

  18. The ultimate quantum limits on the accuracy of measurements

    NASA Technical Reports Server (NTRS)

    Yuen, Horace P.

    1992-01-01

    A quantum generalization of rate-distortion theory from standard communication and information theory is developed for application to determining the ultimate performance limit of measurement systems in physics. For the estimation of a real or a phase parameter, it is shown that the root-mean-square error obtained in a measurement with a single-mode photon level N cannot do better than approximately N exp -1, while approximately exp(-N) may be obtained for multi-mode fields with the same photon level N. Possible ways to achieve the remarkable exponential performance are indicated.

  19. The Displacement Perspective During Ultimate Failure of Composite Laminates

    NASA Astrophysics Data System (ADS)

    Pal, P.; Bhar, A.

    2013-04-01

    This paper deals with the studies on the state of displacement of symmetric and anti-symmetric angle-ply and cross-ply laminated composite plates during its ultimate failure, subjected to transverse static load. First-order shear deformation theory (FSDT) is employed in conjunction with the finite element approach using eight-noded quadratic isoparametric element. The free vibration analyses of isotropic and laminated composite plates are carried out to ensure the overall validity of the present finite element formulation. The mid surface of the laminate is considered as the reference plane. The principal material directions in different laminae are oriented to produce a laminated structural element capable of resisting loads in several directions. The stiffness of a composite laminate is obtained from the properties of the constituent laminae. The affected stiffness of the failed lamina is discarded completely after the failure of weakest ply. The rigidity matrix of the laminate with remaining laminae is re-established. The re-evaluation process continues until the laminate fails completely. To investigate the displacement behaviour of laminates during the ultimate failure, parametric studies are carried out for different cases by varying the stacking sequences, fiber orientations, layer thicknesses, aspect ratios and the number of layers in the laminate. The comparison of results in terms of non-dimensional natural frequencies and ply-by-ply failure analyses obtained from the present investigation are made with those available in the reported literature.

  20. Methods for ultimate load analysis of concrete containments

    SciTech Connect

    Dunham, R.S.; Rashid, Y.R.; Yuan, K.A.; Lu, Y.M.

    1985-06-01

    The objective of the research project described in this interim report is to develop a qualified methodology for the ultimate load analysis of concrete containment structures. The EPRI-sponsored nonlinear finite element code ABAQUS-EPGEN, which has recently been modified to incorporate a constitutive model for plain concrete and modeling capabilities for reinforced and prestressed concrete containments, is utilized as the structural analysis tool in this development. The ABAQUS-EPGEN concrete modeling and analysis capabilities are first evaluated by comparing measured data with code predictions for full-scale reinforced concrete slab specimens tested under uniaxial and biaxial tension. These specimen tests simulate the behavior of the cylindrical wall of a typical concrete containment structure under internal pressure. The calculated and measured strain comparisons are used to improve the constitutive model and to qualify the code for concrete containment analysis. The second part of this effort deals with the ultimate load analysis of reinforced and prestressed containments to determine bounds on the global overpressure capacities of typical concrete containment structures. The third part of this effort further examines such local effects through a substructural analysis of the liner-concrete interaction at major concrete cracks.

  1. Pork Quality Traits According to Postmortem pH and Temperature in Berkshire

    PubMed Central

    Kim, Tae Wan; Kim, Chul Wook; Yang, Mi Ra; No, Gun Ryoung; Kim, Il-Suk

    2016-01-01

    This study was performed to investigate the role of pH and temperature postmortem, and to demonstrate the importance of these factors in determining meat quality. Postmortem pH45min (pH at 45 min postmortem or initial pH) via analysis of Pearson’s correlation showed high positive correlation with pH change pHc24 (pH change from pH45min to pH24h postmortem). However, postmortem pH after 24 h (pH24h or ultimate pH) had a high negative correlation with pH change, pHc24, CIE L*, and protein content. Initial temperature postmortem (T1h ) was positively associated with a change in temperature from 45 min to 24 h postmortem (Tc24) and cooking loss, but negatively correlated with water holding capacity. Temperature at 24 h postmortem (T24h) was negatively associated with Tc24. Collectively, these results indicate that higher initial pH was associated with higher pHc24, T1h, and Tc24. However, higher initial pH was associated with a reduction in carcass weight, backfat thickness, CIE a* and b*, water holding capacity, collagen and fat content, drip loss, and cooking loss as well as decreased shear force. In contrast, CIE a* and b*, drip loss, cooking loss, and shear force in higher ultimate pH was showed by a similar pattern to higher initial pH, whereas pHc24, carcass weight, backfat thickness, water holding capacity, fat content, moisture content, protein content, T1h, T24h, and Tc24 were exhibited by completely differential patterns (p<0.05). Therefore, we suggest that initial pH, ultimate pH, and temperatures postmortem are important factors in determining the meat quality of pork. PMID:27499661

  2. Atmospheric effects and ultimate ranging accuracy for lunar laser ranging

    NASA Astrophysics Data System (ADS)

    Currie, Douglas G.; Prochazka, Ivan

    2014-10-01

    The deployment of next generation lunar laser retroreflectors is planned in the near future. With proper robotic deployment, these will support single shot single photo-electron ranging accuracy at the 100 micron level or better. There are available technologies for the support at this accuracy by advanced ground stations, however, the major question is the ultimate limit imposed on the ranging accuracy due to the changing timing delays due to turbulence and horizontal gradients in the earth's atmosphere. In particular, there are questions of the delay and temporal broadening of a very narrow laser pulse. Theoretical and experimental results will be discussed that address estimates of the magnitudes of these effects and the issue of precision vs. accuracy.

  3. Plug nozzles: The ultimate customer driven propulsion system

    NASA Technical Reports Server (NTRS)

    Aukerman, Carl A.

    1991-01-01

    This paper presents the results of a study applying the plug cluster nozzle concept to the propulsion system for a typical lunar excursion vehicle. Primary attention for the design criteria is given to user defined factors such as reliability, low volume, and ease of propulsion system development. Total thrust and specific impulse are held constant in the study while other parameters are explored to minimize the design chamber pressure. A brief history of the plug nozzle concept is included to point out the advanced level of technology of the concept and the feasibility of exploiting the variables considered in this study. The plug cluster concept looks very promising as a candidate for consideration for the ultimate customer driven propulsion system.

  4. Ultimate photovoltage in perovskite oxide heterostructures with critical film thickness

    SciTech Connect

    Wang Cong; Jin Kuijuan; Zhao Ruiqiang; Lu Huibin; Guo Haizhong; Ge Chen; He Meng; Wang Can; Yang Guozhen

    2011-05-02

    One order larger photovoltage is obtained with critical thicknesses of La{sub 0.9}Sr{sub 0.1}MnO{sub 3} films in both kinds of heterostructures of La{sub 0.9}Sr{sub 0.1}MnO{sub 3}/SrTiO{sub 3} (0.8 wt % Nb-doped) and La{sub 0.9}Sr{sub 0.1}MnO{sub 3}/Si fabricated at various oxygen pressures. Our self-consistent calculation reveals that the critical thickness of the La{sub 0.9}Sr{sub 0.1}MnO{sub 3} film with the ultimate value of photovoltage is just the thickness of the depletion layer of La{sub 0.9}Sr{sub 0.1}MnO{sub 3} in both heterojunctions, respectively.

  5. Ultimate Spectrum of Solar/Stellar Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Struminsky, Alexei

    2015-08-01

    We reconstruct an ultimate spectrum of solar/stellar cosmic rays (SCR) in a given point in the heliosphere (stellar sphere) basing on maximal value of magnetic field strenght in active region and its characteristic linear dimension. An accelerator of given dimensions and magnetic field strengh may accelarate to a finite energy for a given time (a maximal energy of SCR). We will use spectrum of SCR proposed by Syrovatsky (1961) for relativistic and non-relativistic energies normaliszing it to galactic cosmic ray (GCR) intensity at maximal SCR energy. Maximal values of SCR flux propagating in the heliosphere are determined by equilibrium between pressure of interplanetary magnrtic field and dynamic pressure of SCR (Frier&Webber, 1963). The obtained spectra would be applied to explain the extreme solar particle event occurred in about 775 AD basing on the tree-ring chronology (Miyake et al., 2012).

  6. Ultimate drivers of native biodiversity change in agricultural systems

    PubMed Central

    Norton, David A; Reid, Nick; Young, Laura

    2013-01-01

    The ability to address land degradation and biodiversity loss while maintaining the production of plant and animal products is a key global challenge. Biodiversity decline as a result of vegetation clearance, cultivation, grazing, pesticide and herbicide application, and plantation establishment, amongst other factors, has been widely documented in agricultural ecosystems. In this paper we identify six ultimate drivers that underlie these proximate factors and hence determine what native biodiversity occurs in modern agricultural landscapes; (1) historical legacies; (2) environmental change; (3) economy; (4) social values and awareness; (5) technology and knowledge; and (6) policy and regulation. While historical legacies and environmental change affect native biodiversity directly, all six indirectly affect biodiversity by influencing the decisions that land managers make about the way they use their land and water resources. Understanding these drivers is essential in developing strategies for sustaining native biodiversity in agricultural landscapes into the future. PMID:26834971

  7. Helium separation via porous silicene based ultimate membrane.

    PubMed

    Hu, Wei; Wu, Xiaojun; Li, Zhenyu; Yang, Jinlong

    2013-10-01

    Helium purification has become more important for increasing demands in scientific and industrial applications. In this work, we demonstrated that the porous silicene can be used as an effective ultimate membrane for helium purification on the basis of first-principles calculations. Prinstine silicene monolayer is impermeable to helium gas with a high penetration energy barrier (1.66 eV). However, porous silicene with either Stone-Wales (SW) or divacancy (555,777 or 585) defect presents a surmountable barrier for helium (0.33 to 0.78 eV) but formidable for Ne, Ar, and other gas molecules. In particular, the porous silicene with divacancy defects shows high selectivity for He/Ne and He/Ar, superior to graphene, polyphenylene, and traditional membranes.

  8. Ultimate Drivers and Proximate Correlates of Polyandry in Predatory Mites

    PubMed Central

    Schausberger, Peter; Patiño-Ruiz, J. David; Osakabe, Masahiro; Murata, Yasumasa; Sugimoto, Naoya; Uesugi, Ryuji; Walzer, Andreas

    2016-01-01

    Polyandry is more widespread than anticipated from Bateman’s principle but its ultimate (evolutionary) causes and proximate (mechanistic) correlates are more difficult to pinpoint than those of polygyny. Here, we combined mating experiments, quantification of reproductive traits and microsatellite genotyping to determine the fitness implications of polyandry in two predatory mite species, where males are highly polygynous (up to 45 fertilized females during life), whereas females range from monandry to various polyandry levels. The medium-level polyandrous (up to eight male mates possible) Neoseiulus californicus received clear direct and indirect benefits: multiply mated females produced more offspring with higher survival chances over longer times than singly mated females. In contrast, singly and multiply mated females of the low-level polyandrous (commonly two male mates at maximum) Phytoseiulus persimilis produced similar numbers of offspring having similar survival chances. In both species, multiple mating resulted in mixed offspring paternities, opening the chance for indirect fitness benefits such as enhanced genetic compatibility, complementarity and/or variability. However, the female re-mating likelihood and the paternity chance of non-first male mates were lower in P. persimilis than in N. californicus. Regarding proximate factors, in both species first mating duration and female re-mating likelihood were negatively correlated. Based on occasional fertilization failure of first male mates in P. persimilis, and mixed offspring paternities in both species, we argue that fertilization assurance and the chance to gain indirect fitness benefits are the ultimate drivers of polyandry in P. persimilis, whereas those of N. californicus are higher offspring numbers coupled with enhanced offspring viability and possibly other indirect fitness benefits. Overall, the adaptive significance and proximate events well reflected the polyandry levels. Our study provides

  9. Future Synchrotron Light Sources Based on Ultimate Storage Rings

    SciTech Connect

    Cai, Yunhai; /SLAC

    2012-04-09

    The main purpose of this talk is to describe how far one might push the state of the art in storage ring design. The talk will start with an overview of the latest developments and advances in the design of synchrotron light sources based on the concept of an 'ultimate' storage ring. The review will establish how bright a ring based light source might be, where the frontier of technological challenges are, and what the limits of accelerator physics are. Emphasis will be given to possible improvements in accelerator design and developments in technology toward the goal of achieving an ultimate storage ring. An ultimate storage ring (USR), defined as an electron ring-based light source having an emittance in both transverse planes at the diffraction limit for the range of X-ray wavelengths of interest for a scientific community, would provide very high brightness photons having high transverse coherence that would extend the capabilities of X-ray imaging and probe techniques beyond today's performance. It would be a cost-effective, high-coherence 4th generation light source, competitive with one based on energy recovery linac (ERL) technology, serving a large number of users studying material, chemical, and biological sciences. Furthermore, because of the experience accumulated over many decades of ring operation, it would have the great advantage of stability and reliability. In this paper we consider the design of an USR having 10-pm-rad emittance. It is a tremendous challenge to design a storage ring having such an extremely low emittance, a factor of 100 smaller than those in existing light sources, especially such that it has adequate dynamic aperture and beam lifetime. In many ultra-low emittance designs, the injection acceptances are not large enough for accumulation of the electron beam, necessitating on-axis injection where stored electron bunches are completely replaced with newly injected ones. Recently, starting with the MAX-IV 7-bend achromatic cell, we

  10. Niche restriction in parasites: proximate and ultimate causes.

    PubMed

    Rohde, K

    1994-01-01

    Hutchinson's (1957) definition of an ecological niche as a multidimensional hypervolume determined by a number of physical and biotic variables is adopted. The number of niche dimensions is very great, but as a working hypothesis it is assumed that a few are sufficient to characterize the niche of a parasite species to a high degree of accuracy. They are host species, microhabitat(s), macrohabitat(s), geographical range, sex and age of host, season, food and hyperparasites. Methods to measure niche width, in particular specificity indices, are discussed, and some examples of niche restriction are described. Proximate and ultimate causes of niche restriction are discussed, mainly using marine parasites as examples. Among proximate causes of one niche dimension, host specificity, are ecological factors restricting exposure to infection to certain host species; host-specific chemical factors that induce hatching, direct infective stages to a host and bring about settlement of a parasite; factors that lead to mortality in or on the wrong host; morphological adaptations that guarantee survival in or on the 'correct' host; and availability of suitable hosts. Many factors are likely to be responsible for microhabitat specificity, but have been little studied, except for some physiological and morphological adaptations to particular microhabitats. Macrohabitats and geographical range may be determined by the distribution of intermediate hosts and certain food items, and by a variety of chemical and physical factors. Hosts of different sexes may differ in feeding habits and the composition of the skin, and thus acquire parasites differentially. Hosts of different age may be differentially infected due to accumulation of parasites with age, loss of parasites due to developing resistance (or immunity), and different size and feeding habits. Among ultimate causes of niche restriction and segregation are avoidance of competition, predation and hyperparasites; facilitation of

  11. Interindividual variability in social insects - proximate causes and ultimate consequences.

    PubMed

    Jeanson, Raphaël; Weidenmüller, Anja

    2014-08-01

    Individuals within social groups often show consistent differences in behaviour across time and context. Such interindividual differences and the evolutionary challenge they present have recently generated considerable interest. Social insects provide some of the most familiar and spectacular examples of social groups with large interindividual differences. Investigating these within-group differences has a long research tradition, and behavioural variability among the workers of a colony is increasingly regarded as fundamental for a key feature of social insects: division of labour. The goal of this review is to illustrate what we know about both the proximate mechanisms underlying behavioural variability among the workers of a colony and its ultimate consequences; and to highlight the many open questions in this research field. We begin by reviewing the literature on mechanisms that potentially introduce, maintain, and adjust the behavioural differentiation among workers. We highlight the fact that so far, most studies have focused on behavioural variability based on genetic variability, provided by e.g. multiple mating of the queen, while other mechanisms that may be responsible for the behavioural differentiation among workers have been largely neglected. These include maturational, nutritional and environmental influences. We further discuss how feedback provided by the social environment and learning and experience of adult workers provides potent and little-explored sources of differentiation. In a second part, we address what is known about the potential benefits and costs of increased behavioural variability within the workers of a colony. We argue that all studies documenting a benefit of variability so far have done so by manipulating genetic variability, and that a direct test of the effect of behavioural variability on colony productivity has yet to be provided. We emphasize that the costs associated with interindividual variability have been largely

  12. Interindividual variability in social insects - proximate causes and ultimate consequences.

    PubMed

    Jeanson, Raphaël; Weidenmüller, Anja

    2014-08-01

    Individuals within social groups often show consistent differences in behaviour across time and context. Such interindividual differences and the evolutionary challenge they present have recently generated considerable interest. Social insects provide some of the most familiar and spectacular examples of social groups with large interindividual differences. Investigating these within-group differences has a long research tradition, and behavioural variability among the workers of a colony is increasingly regarded as fundamental for a key feature of social insects: division of labour. The goal of this review is to illustrate what we know about both the proximate mechanisms underlying behavioural variability among the workers of a colony and its ultimate consequences; and to highlight the many open questions in this research field. We begin by reviewing the literature on mechanisms that potentially introduce, maintain, and adjust the behavioural differentiation among workers. We highlight the fact that so far, most studies have focused on behavioural variability based on genetic variability, provided by e.g. multiple mating of the queen, while other mechanisms that may be responsible for the behavioural differentiation among workers have been largely neglected. These include maturational, nutritional and environmental influences. We further discuss how feedback provided by the social environment and learning and experience of adult workers provides potent and little-explored sources of differentiation. In a second part, we address what is known about the potential benefits and costs of increased behavioural variability within the workers of a colony. We argue that all studies documenting a benefit of variability so far have done so by manipulating genetic variability, and that a direct test of the effect of behavioural variability on colony productivity has yet to be provided. We emphasize that the costs associated with interindividual variability have been largely

  13. Histologic remission: the ultimate therapeutic goal in ulcerative colitis?

    PubMed

    Peyrin-Biroulet, Laurent; Bressenot, Aude; Kampman, Wendy

    2014-06-01

    Ulcerative colitis (UC) is a disease of the mucosal layer, and activity of the disease is assumed to be related to mucosal appearance. Mucosal healing has emerged as a major therapeutic goal in UC. Whether mucosal healing should be the ultimate therapeutic goal in these patients is unknown. Even when endoscopy suggests mucosal healing, evidence of histologic activity has been observed. Histologic healing requires complete recovery of the colonic mucosa, with absence of inflammation or structural changes. Histologic improvements have been linked with improved clinical outcomes, such as a reduced risk of relapse and need for surgery/hospitalization and a reduced risk of developing cancer. Hence, there is a rationale for aiming for histologic remission in UC. Numerous methods of classification of histologic activity in UC have been proposed, although only some of these are widely used. We review the current definitions of histologic remission, the range of scoring systems most commonly used, and the evidence of histologic improvement that is available from the latest therapies for UC. We also highlight questions that will require careful consideration if histologic remission is to become more widely used as an end point in clinical trials and a treatment goal in clinical practice. PMID:23911875

  14. The ultimate band compression factor in gradient elution chromatography

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2008-01-01

    The equations predicting the ultimate time band compression factor, G = (t{sub R}-t{sub F})/t{sub p} in linear gradient elution chromatography, for an infinitely narrow injection (injection time t{sub p} {yields} 0) were derived for an ideal-model column (dispersionless chromatography, H = 0) assuming the Linear Solvent Strength Model for the retention behavior of the analyte. Numerical solutions can readily be obtained when the LSSM model does not apply. The results can be generalized to any retained organic modifier (k'{sub A}) in the mobile phase. The stronger the retention of the organic modifier, the more effective the band compression. Dispersion in real chromatographic column (H {ne} 0) affects the limits that can be reached in linear gradients but poorly in step gradients. Examples based on a conventional HETP of about 12 {micro}m using a 5 {micro}m particle packed column reveal that the best time compression factor that could be expected is twice the one predicted with an ideal column.

  15. Optimized molten salt receivers for ultimate trough solar fields

    NASA Astrophysics Data System (ADS)

    Riffelmann, Klaus-J.; Richert, Timo; Kuckelkorn, Thomas

    2016-05-01

    Today parabolic trough collectors are the most successful concentrating solar power (CSP) technology. For the next development step new systems with increased operation temperature and new heat transfer fluids (HTF) are currently developed. Although the first power tower projects have successfully been realized, up to now there is no evidence of an all-dominant economic or technical advantage of power tower or parabolic trough. The development of parabolic trough technology towards higher performance and significant cost reduction have led to significant improvements in competitiveness. The use of molten salt instead of synthetic oil as heat transfer fluid will bring down the levelized costs of electricity (LCOE) even further while providing dispatchable energy with high capacity factors. FLABEG has developed the Ultimate TroughTM (UT) collector, jointly with sbp Sonne GmbH and supported by public funds. Due to its validated high optical accuracy, the collector is very suitable to operate efficiently at elevated temperatures up to 550 °C. SCHOTT will drive the key-innovations by introducing the 4th generation solar receiver that addresses the most significant performance and cost improvement measures. The new receivers have been completely redesigned to provide a product platform that is ready for high temperature operation up to 550 °C. Moreover distinct product features have been introduced to reduce costs and risks in solar field assembly and installation. The increased material and design challenges incurred with the high temperature operation have been reflected in sophisticated qualification and validation procedures.

  16. Digital exchange of graphic arts material: the ultimate challenge

    NASA Astrophysics Data System (ADS)

    McDowell, David Q.

    1996-01-01

    The digital exchange of graphic arts material -- particularly advertising material for publications -- in an open standardized environment represents the ultimate challenge for electronic data exchange. To meet the needs of publication advertising, the graphic arts industry must be able to transmit advertisements in an open environment where there are many senders and many receivers of the material. The material being transmitted consists of combinations of pictorial material, text, and line art with these elements superimposed on top of each other and/or interrelated in complex ways. The business relationships established by the traditional workflow environment, the combination of aesthetic and technical requirements, and the large base of existing hardware and software play a major role in limiting the options available. Existing first- and second-generation standards are focused on the CEPS environment, which operates on and stores data as raster files. The revolution in personal computer hardware and software, and the acceptance of these tools by the graphic arts community, dictates that standards must also be created and implemented for this world of vector/raster-based systems. The requirements for digital distribution of advertising material for publications, the existing graphic arts standards base, and the anticipation of future standards developments in response to these needs are explored.

  17. Plant Habitat (PH)

    NASA Technical Reports Server (NTRS)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  18. X-ray lasers - the ultimate radiation source?

    SciTech Connect

    Matthews, D.L.

    1995-12-31

    I will review the development of the x-ray laser from its first demonstration in 1984 to today`s systems which operate from 45 to 3.5 nm with output power levels up to GW and linewidths less than 10{sup -4}. At first, these sources required large pump laser facility in order to be produced, but just now new systems are appearing which are much more efficient and are near table-top in size. I will also discuss the future development of this source which should lead to wavelengths as short as 1 nm with a near-diffraction-limited output characteristics and considerable average output power, up to 10{sup 15} ph/sec. Finally, I will discuss some of the interesting applications such as in vitro biological imaging, microsurgery on microorganisms, construction of nanomachines, probing of semiconductors and plasmas, lithographic printing of semiconductor circuits and numerous other potential uses.

  19. The development of high cooling power and low ultimate temperature superfluid Stirling refrigerators

    NASA Astrophysics Data System (ADS)

    Patel, Ashok B.

    demonstrated and further work is still required. However, despite these difficulties, one of the two stage SSR's was able to reach an ultimate low temperature of 248 mK from a high temperature of 1.03 K. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

  20. pH Basics

    ERIC Educational Resources Information Center

    Lunelli, Bruno; Scagnolari, Francesco

    2009-01-01

    The exposition of the pervasive concept of pH, of its foundations and implementation as a meaningful quantitative measurement, in nonspecialist university texts is often not easy to follow because too many of its theoretical and operative underpinnings are neglected. To help the inquiring student we provide a concise introduction to the depth just…

  1. pH optrode

    DOEpatents

    Northrup, M. Allen; Langry, Kevin C.

    1993-01-01

    A process is provided for forming a long-lasting, stable, pH-sensitive dye-acrylamide copolymer useful as a pH-sensitive material for use in an optrode or other device sensitive to pH. An optrode may be made by mechanically attaching the copolymer to a sensing device such as an optical fiber.

  2. Differentiation of muscle and the determination of ultimate tissue size.

    PubMed

    Penney, R K; Prentis, P F; Marshall, P A; Goldspink, G

    1983-01-01

    The factors that determine ultimate muscle size have been studied using a "model" that involves two strains of mice, which had been especially bred for "largeness" (QL) and for "smallness" (QS). The difference in muscle size was not found to be due to a difference in fibre size, but due to a difference in fibre number. The muscles from the "QL" mice contained about 30% more fibres. The reason for this increased fibre number was investigated. During early development, the fusion of mononucleated presumptive myoblasts to form multinucleated myotubes took place at the same time in both "QL" and "OS" mice, as indicated by the appearance and increase in activity of ATP: creatine phosphotransferase. At this stage fibre (and cell) number and size could be determined by measuring nuclear number and protein/DNA ratio respectively. No difference in fibre (and cell) size could be found in mice at 5 days before birth, newly born, or at 20 days of age. At these ages it was found that the muscles from the "QL" mice contained a greater number of nuclei (muscle cells). The amount of RNA/nucleus was used as an index of protein synthetic rate, and no difference could be found between the large mice and the small mice. It was concluded that, in the case of the "QL" mice, the increased fibre number was not brought about by: (i) a delay in time of fusion of presumptive myoblasts; (ii) a smaller number of myoblasts fusing to form myotubes; or (iii) extensive fibre formation after fusion. Differences in fibre number, and hence muscle size, must therefore, presumably be caused by initial differences in the rate of proliferation of myoblasts before fusion.

  3. Understanding Early Post-Mortem Biochemical Processes Underlying Meat Color and pH Decline in the Longissimus thoracis Muscle of Young Blond d'Aquitaine Bulls Using Protein Biomarkers.

    PubMed

    Gagaoua, Mohammed; Terlouw, E M Claudia; Micol, Didier; Boudjellal, Abdelghani; Hocquette, Jean-François; Picard, Brigitte

    2015-08-01

    Many studies on color biochemistry and protein biomarkers were undertaken in post-mortem beef muscles after ≥24 hours. The present study was conducted on Longissimus thoracis muscles of 21 Blond d'Aquitaine young bulls to evaluate the relationships between protein biomarkers present during the early post-mortem and known to be related to tenderness and pH decline and color development. pH values at 45 min, 3 h, and 30 h post-mortem were correlated with three, seven, and six biomarkers, respectively. L*a*b* color coordinates 24 h post-mortem were correlated with nine, five, and eight protein biomarkers, respectively. Regression models included Hsp proteins and explained between 47 and 59% of the variability between individuals in pH and between 47 and 65% of the variability in L*a*b* color coordinates. Proteins correlated with pH and/or color coordinates were involved in apoptosis or had antioxidative or chaperone activities. The main results include the negative correlations between pH45 min, pH3 h, and pHu and Prdx6, which may be explained by the antioxidative and phospholipase activities of this biomarker. Similarly, inducible Hsp70-1A/B and μ-calpain were correlated with L*a*b* coordinates, due to the protective action of Hsp70-1A/B on the proteolytic activities of μ-calpain on structural proteins. Correlations existed further between MDH1, ENO3, and LDH-B and pH decline and color stability probably due to the involvement of these enzymes in the glycolytic pathway and, thus, the energy status of the cell. The present results show that research using protein indicators may increase the understanding of early post-mortem biological mechanisms involved in pH and beef color development.

  4. Ultimate VHF Broadband Interferometer Zen KAWASAKI and Manabu AKITA

    NASA Astrophysics Data System (ADS)

    Kawasaki, Z.; Akita, M.

    2013-12-01

    propagation, like electromagnetic wave propagation in non-dispersive medium. This procedure presented exciting results of lightning channel imaging, and the bi-directional leader propagation can be visualized in terms of azimuth and elevation as a function of time. Moreover all of the VHF radiation process for an entire lightning flash from initiation to termination can be imaged, and it is concluded that the system might be an ultimate broad band digital interferometer. The authors would like to show their appreciation to Paul Krehbiel, NMIMT, who gave a chance and suggestion of a continuous recording scheme for BDITF. M. Stock et al. : Continuous Broadband Digital Interferometry of Lightning using a Generalized Cross Correlation Algorithm M. Akita et al. : Data Processing Procedure 1 using Distribution of Slopes of Phase Differences for Broadband VHF Interferometer

  5. [The relationships of Zhang Jing-yue's three theories of the Supreme Ultimate].

    PubMed

    Yao, Chun-Peng

    2007-07-01

    Under the influence of Supreme Ultimate of Neo-Confucianism, Zhang Jing-yue put forward the three theories of the Supreme Ultimate, viz., Supreme Ultimate of the Primordial Qi, Supreme Ultimate of the Heart, and Supreme Ultimate of the Vital Gate. These three theories were of trinity relationship, forming the basic frame of Jingyue's system of medical theories. Among them, the theory of Supreme Ultimate of the Primordial Qi was the foundation of natural concept in his medical theories, the theory of Supreme Ultimate of the Vital Gate was the teleology of his medical theories, and the theory of Supreme Ultimate of the Heart, as a cognitive method, was the methodology of his medical theories. Jing-yue' s medical theories were constructed on these three corner-stays, which was a tremendous leap forward in the development of traditional Chinese medicine and Neo-Confucianism. PMID:18453202

  6. Nano-protoplasm: the ultimate unit of life.

    PubMed

    Ling, Gilbert

    2007-01-01

    Among the most promising scientific achievements of the 19th century was the recognition that the laws governing the dead world also govern the world of the living and that life has a physical basis called protoplasm. Regrettably, the definition of protoplasm provided then was (inescapably) incorrect, offering a (legitimate) reason for rejecting the concept of protoplasm by an overwhelming majority of later investigators, teachers and other opinion-makers. Without a recognized physical basis, Life itself also faded into the limbo of the unexplainable. However, eventually the needed relevant parts of physics and chemistry to give a more cogent definition of protoplasm became available. That then made possible the construction in the early 1960's of a unifying theory of the living cell, named the association-induction (AI) hypothesis. Historically speaking, the AI Hypothesis is the heir to the general concept of protoplasm as the physical basis of life-incorrect as the initial definition of protoplasm was notwithstanding. In the AI Hypothesis (AIH) the true or ultimate physical basis of life is not what the advocates of the protoplasm once considered as the physical basis of life. What they saw and construed as the physical basis of life is a particular kind of macroscopic protoplasm. In the AI Hypothesis, the basic unit (or physical basis) of life is microscopic protoplasm or nano-protoplasm, of which all macroscopic protoplasm is made. The AI Hypothesis also had no difficulty offering a new definition to what life is in terms of fundamental physical-chemical laws. Nano-protoplasm is defined by what it is and what it does. In greater detail, it is defined (i) by its chemical composition given in Equation 1 on p. 124; (ii) by the mutual spatial and energetic relationships among the components as illustrated diagrammatically in Figure 5 on p. 125; and (iii) by the ability of these components to exist as coherent assemblies in either one of two alternative states, the

  7. 17-4 PH and 15-5 PH

    NASA Technical Reports Server (NTRS)

    Johnson, Howard T.

    1995-01-01

    17-4 PH and 15-5 PH are extremely useful and versatile precipitation-hardening stainless steels. Armco 17-4 PH is well suited for the magnetic particle inspection requirements of Aerospace Material Specification. Armco 15-5 PH and 17-4 PH are produced in billet, plate, bar, and wire. Also, 15-5 PH is able to meet the stringent mechanical properties required in the aerospace and nuclear industries. Both products are easy to heat treat and machine, making them very useful in many applications.

  8. BOOK REVIEW: Seeking Ultimates. An Intuitive Guide to Physics

    NASA Astrophysics Data System (ADS)

    Brown, Neil

    2000-05-01

    Physics has the reputation of being a difficult and dry subject. Many books have been written in attempts to show that the difficulties are not insurmountable, even for the layman, and to convey some of the fascination it provides for those within it. In Seeking Ultimates Peter Landsberg avoids mathematics, the source of so many difficulties, entirely, and seeks to make physics comprehensible by what he terms intuition. He also emphasizes that there is almost no part of science that is completely understood; there are always areas of incompleteness and uncertainty, capable of providing exciting new results, and examples of this are highlighted throughout the book. After an introduction Landsberg starts with macroscopic phenomena for ease of understanding, though one might question whether the chosen topic of thermodynamics is ever going to be easy. Next he looks at microscopic effects, from atomic structure to the fundamental particles of the standard model and their interactions. There follow chapters on time and entropy, on chaos theory, on quantum mechanics and then cosmology. The final chapters look at physical constants (including the anthropic principle), whether physics has room for a creator God (the conclusion is that this is not the province of science), and some thoughts on science as a human activity. The chosen topics are those which have been important in the late twentieth century and remain important. Each chapter cites an eminent scientist as a `hero', though little is made of this. There are occasional historical notes, set in boxes, and a few short poems to leaven the text. What the book achieves is difficult to assess. Removing mathematics and adding a glossary of technical terms do not necessarily allow non-scientists to enjoy the text, as the publisher's note on the back cover suggests. The concepts can baffle the layman even more than the mathematics, and one of the most difficult of all physical concepts permeates so much of this book

  9. Urine pH test

    MedlinePlus

    A urine pH test measures the level of acid in urine. ... pH - urine ... meat products, or cheese can decrease your urine pH. ... to check for changes in your urine acid levels. It may be done to ... more effective when urine is acidic or non-acidic (alkaline).

  10. Effect of load eccentricity and substructure deformation on ultimate strength of shuttle orbiter thermal protection system

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.

    1981-01-01

    The effect of load eccentricity and substructure deformation on the ultimate strength and stress displacement properties of the shuttle orbiter thermal protection system (TPS) was determined. The LI-900 Reusable Surface Insulation (RSI) tiles mounted on the .41 cm thick Strain Isolator Pad (SIP) were investigated. Substructure deformations reduce the ultimate strength of the SIP/tile TPS and increase the scatter in the ultimate strength data. Substructure deformations that occur unsymmetric to the tile can cause the tile to rotate when subjected to a uniform applied load. Load eccentricity reduces SIP/tile TPS ultimate strength and causes tile rotation.

  11. Ionizable drugs and pH oscillators: buffering effects.

    PubMed

    Misra, Gauri P; Siegel, Ronald A

    2002-09-01

    It has been proposed that chemical pH oscillators may form a basis for periodic, pulsed drug delivery of weak acids and bases across lipophilic membranes. However, drugs have been shown to interfere with the ability of the chemical systems to oscillate, and rhythmic delivery of drugs by this means has been demonstrated only under constrained circumstances. Herein, we provide evidence that low concentrations of acidic drugs can attenuate and ultimately quench chemical pH oscillators, by a simple buffering mechanism. A model system consisting of the bromate-sulfite-marble pH oscillator in a continuous stirred tank reactor is used, along with acidic drugs of varying concentration and acid dissociation constant, pK(D). A published kinetic model for this oscillator is modified to account for the presence of acidic drug, and the results of this model are in qualitative agreement with the experimental results. PMID:12210047

  12. 75 FR 76746 - Agency Information Collection Activities: Declaration of Ultimate Consignee That Articles Were...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-09

    ... (75 FR 60133) on September 29, 2010, allowing for a 60-day comment period. No comments were received... Ultimate Consignee That Articles Were Exported for Temporary Scientific or Educational Purposes AGENCY: U.S... the Paperwork Reduction Act: Declaration of Ultimate Consignee That Articles Were Exported...

  13. The pH Game.

    ERIC Educational Resources Information Center

    Chemecology, 1996

    1996-01-01

    Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

  14. The Responsive Ph.D.: Innovations in U.S. Doctoral Education

    ERIC Educational Resources Information Center

    Weisbuch, Robert

    2005-01-01

    The Woodrow Wilson Foundation does not like to write reports. Typically, Woodrow Wilson translates ideas into academic practices. This said, having engaged 14 (and ultimately 20) graduate schools to work on the Responsive Ph.D.--as the authors called their initiative--it is time to report on what they have accomplished, and on what they have…

  15. A new method to characterize the complex mineralogy of ultimate wastes

    SciTech Connect

    Forestier, L. Le; Brown, W.L.; Libourel, G. |

    1995-12-31

    Ultimate wastes, resulting from the incineration of municipal solid wastes, contain high amounts of toxic elements that require stabilization before storage. However, whatever the stabilization processed involved, characterization of their crystal chemistry is essential. In this paper, the authors present a method which allows the determination of the mineralogy of ultimate wastes in detail. They present here an example of results from an ultimate waste, resulting from electrofiltration of fumes. This method is based on grain size and density separations coupled with X-ray diffraction, ICP-ES, ICP-MS, wet chemical methods and electron microprobe analyses. Despite the complexity of this waste, they show that it is possible, not only to determine its mineralogy, but also to give the modal proportions of each phase, and to provide some insights into the crystal chemistry of the main pollutants of this ultimate waste product.

  16. METHYLATED ASIII COMPOUNDS AS POTENTIAL PROXIMATE/ULTIMATE GENOTOXIC METABOLITES OF INORGANIC ARSENIC

    EPA Science Inventory

    METHYLATED Asm COMPOUNDS AS POTENTIAL PROXIMATE/ULTIMATE GENOTOXIC METABOLITES OF INORGANIC ARSENIC.

    The methylation of inorganic arsenic has typically been viewed as a detoxification process. Genotoxicity tests have generally shown that arsenite has greater mutagenic p...

  17. Esophageal pH monitoring

    MedlinePlus

    pH monitoring - esophageal; Esophageal acidity test ... esophagitis You may need to have the following tests if your doctor suspects esophagitis : Barium swallow Esophagogastroduodenoscopy (also called upper GI endoscopy)

  18. PhEDEx Data Service

    NASA Astrophysics Data System (ADS)

    Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

    2010-04-01

    The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the "SiteDB" service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

  19. Reconstructing Ocean pH with Boron Isotopes in Foraminifera

    NASA Astrophysics Data System (ADS)

    Foster, Gavin L.; Rae, James W. B.

    2016-06-01

    In order to better understand the effect of CO2 on the Earth system in the future, geologists may look to CO2-induced environmental change in Earth's past. Here we describe how CO2 can be reconstructed using the boron isotopic composition (δ11B) of marine calcium carbonate. We review the chemical principles that underlie the proxy, summarize the available calibration data, and detail how boron isotopes can be used to estimate ocean pH and ultimately atmospheric CO2 in the past. δ11B in a variety of marine carbonates shows a coherent relationship with seawater pH, in broad agreement with simple models for this proxy. Offsets between measured and predicted δ11B may in part be explained by physiological influences, though the exact mechanisms of boron incorporation into carbonate remain unknown. Despite these uncertainties, we demonstrate that δ11B may provide crucial constraints on past ocean acidification and atmospheric CO2.

  20. In vitro colonization of the muscle extracellular matrix components by Escherichia coli O157:H7: the influence of growth medium, temperature and pH on initial adhesion and induction of biofilm formation by collagens I and III.

    PubMed

    Chagnot, Caroline; Agus, Allison; Renier, Sandra; Peyrin, Frédéric; Talon, Régine; Astruc, Thierry; Desvaux, Mickaël

    2013-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 are responsible for repeated food-poisoning cases often caused by contaminated burgers. EHEC infection is predominantly a pediatric illness, which can lead to life-threatening diseases. Ruminants are the main natural reservoir for EHEC and food contamination almost always originates from faecal contamination. In beef meat products, primary bacterial contamination occurs at the dehiding stage of slaughtering. The extracellular matrix (ECM) is the most exposed part of the skeletal muscles in beef carcasses. Investigating the adhesion to the main muscle fibrous ECM proteins, insoluble fibronectin, collagen I, III and IV, laminin-α2 and elastin, results demonstrated that the preceding growth conditions had a great influence on subsequent bacterial attachment. In the tested experimental conditions, maximal adhesion to fibril-forming collagens I or III occurred at 25°C and pH 7. Once initially adhered, exposure to lower temperatures, as applied to meat during cutting and storage, or acidification, as in the course of post-mortem physiological modifications of muscle, had no effect on detachment, except at pHu. In addition, dense biofilm formation occurred on immobilized collagen I or III and was induced in growth medium supplemented with collagen I in solution. From this first comprehensive investigation of EHEC adhesion to ECM proteins with respect to muscle biology and meat processing, new research directions for the development of innovative practices to minimize the risk of meat contamination are further discussed. PMID:23516631

  1. In vitro colonization of the muscle extracellular matrix components by Escherichia coli O157:H7: the influence of growth medium, temperature and pH on initial adhesion and induction of biofilm formation by collagens I and III.

    PubMed

    Chagnot, Caroline; Agus, Allison; Renier, Sandra; Peyrin, Frédéric; Talon, Régine; Astruc, Thierry; Desvaux, Mickaël

    2013-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 are responsible for repeated food-poisoning cases often caused by contaminated burgers. EHEC infection is predominantly a pediatric illness, which can lead to life-threatening diseases. Ruminants are the main natural reservoir for EHEC and food contamination almost always originates from faecal contamination. In beef meat products, primary bacterial contamination occurs at the dehiding stage of slaughtering. The extracellular matrix (ECM) is the most exposed part of the skeletal muscles in beef carcasses. Investigating the adhesion to the main muscle fibrous ECM proteins, insoluble fibronectin, collagen I, III and IV, laminin-α2 and elastin, results demonstrated that the preceding growth conditions had a great influence on subsequent bacterial attachment. In the tested experimental conditions, maximal adhesion to fibril-forming collagens I or III occurred at 25°C and pH 7. Once initially adhered, exposure to lower temperatures, as applied to meat during cutting and storage, or acidification, as in the course of post-mortem physiological modifications of muscle, had no effect on detachment, except at pHu. In addition, dense biofilm formation occurred on immobilized collagen I or III and was induced in growth medium supplemented with collagen I in solution. From this first comprehensive investigation of EHEC adhesion to ECM proteins with respect to muscle biology and meat processing, new research directions for the development of innovative practices to minimize the risk of meat contamination are further discussed.

  2. Ultimate pier and contraction scour prediction in cohesive soils at selected bridges in Illinois

    USGS Publications Warehouse

    Straub, Timothy D.; Over, Thomas M.; Domanski, Marian M.

    2013-01-01

    The Scour Rate In COhesive Soils-Erosion Function Apparatus (SRICOS-EFA) method includes an ultimate scour prediction that is the equilibrium maximum pier and contraction scour of cohesive soils over time. The purpose of this report is to present the results of testing the ultimate pier and contraction scour methods for cohesive soils on 30 bridge sites in Illinois. Comparison of the ultimate cohesive and noncohesive methods, along with the Illinois Department of Transportation (IDOT) cohesive soil reduction-factor method and measured scour are presented. Also, results of the comparison of historic IDOT laboratory and field values of unconfined compressive strength of soils (Qu) are presented. The unconfined compressive strength is used in both ultimate cohesive and reduction-factor methods, and knowing how the values from field methods compare to the laboratory methods is critical to the informed application of the methods. On average, the non-cohesive method results predict the highest amount of scour, followed by the reduction-factor method results; and the ultimate cohesive method results predict the lowest amount of scour. The 100-year scour predicted for the ultimate cohesive, noncohesive, and reduction-factor methods for each bridge site and soil are always larger than observed scour in this study, except 12% of predicted values that are all within 0.4 ft of the observed scour. The ultimate cohesive scour prediction is smaller than the non-cohesive scour prediction method for 78% of bridge sites and soils. Seventy-six percent of the ultimate cohesive predictions show a 45% or greater reduction from the non-cohesive predictions that are over 10 ft. Comparing the ultimate cohesive and reduction-factor 100-year scour predictions methods for each bridge site and soil, the scour predicted by the ultimate cohesive scour prediction method is less than the reduction-factor 100-year scour prediction method for 51% of bridge sites and soils. Critical shear stress

  3. Universal limiter for transient interpolation modeling of the advective transport equations: The ULTIMATE conservative difference scheme

    NASA Technical Reports Server (NTRS)

    Leonard, B. P.

    1988-01-01

    A fresh approach is taken to the embarrassingly difficult problem of adequately modeling simple pure advection. An explicit conservative control-volume formation makes use of a universal limiter for transient interpolation modeling of the advective transport equations. This ULTIMATE conservative difference scheme is applied to unsteady, one-dimensional scalar pure advection at constant velocity, using three critical test profiles: an isolated sine-squared wave, a discontinuous step, and a semi-ellipse. The goal, of course, is to devise a single robust scheme which achieves sharp monotonic resolution of the step without corrupting the other profiles. The semi-ellipse is particularly challenging because of its combination of sudden and gradual changes in gradient. The ULTIMATE strategy can be applied to explicit conservation schemes of any order of accuracy. Second-order schemes are unsatisfactory, showing steepening and clipping typical of currently popular so-called high resolution shock-capturing of TVD schemes. The ULTIMATE third-order upwind scheme is highly satisfactory for most flows of practical importance. Higher order methods give predictably better step resolution, although even-order schemes generate a (monotonic) waviness in the difficult semi-ellipse simulation. Little is to be gained above ULTIMATE fifth-order upwinding which gives results close to the ultimate for which one might hope.

  4. Searches for ultimate chemical carcinogens and their reactions with cellular macromolecules.

    PubMed

    Miller, E C; Miller, J A

    1981-05-15

    Studies on a variety of chemical carcinogens have demonstrated that their ultimate reactive and carcinogenic forms are strong electrophiles. Some carcinogens, such as alkylating agents, are in their ultimate forms as administered, but most require metabolism to these active derivatives. The ultimate carcinogens react, usually non-enzymatically, with nucleophilic constituents in vivo. Of particular interest in regard to their possible importance in carcinogenesis have been the covalent interactions of these electrophilic reactants with cellular informational macromolecules, the DNAs, RNAs, and proteins. Current data are consistent with the idea that the initiation step of chemical carcinogenesis is a mutagenic event and is caused by alteration of DNA by the ultimate carcinogens. The nature of the carcinogen metabolite(s) involved in the promotion phase has not been determined, but there appears to be no requirement that they be electrophilic. The development of the concept of ultimate chemical carcinogens as strong electrophilic reactants is reviewed, especially with respect to the studies carried in the authors' laboratory.

  5. Reduced Design Load Basis for Ultimate Blade Loads Estimation in Multidisciplinary Design Optimization Frameworks

    NASA Astrophysics Data System (ADS)

    Pavese, Christian; Tibaldi, Carlo; Larsen, Torben J.; Kim, Taeseong; Thomsen, Kenneth

    2016-09-01

    The aim is to provide a fast and reliable approach to estimate ultimate blade loads for a multidisciplinary design optimization (MDO) framework. For blade design purposes, the standards require a large amount of computationally expensive simulations, which cannot be efficiently run each cost function evaluation of an MDO process. This work describes a method that allows integrating the calculation of the blade load envelopes inside an MDO loop. Ultimate blade load envelopes are calculated for a baseline design and a design obtained after an iteration of an MDO. These envelopes are computed for a full standard design load basis (DLB) and a deterministic reduced DLB. Ultimate loads extracted from the two DLBs with the two blade designs each are compared and analyzed. Although the reduced DLB supplies ultimate loads of different magnitude, the shape of the estimated envelopes are similar to the one computed using the full DLB. This observation is used to propose a scheme that is computationally cheap, and that can be integrated inside an MDO framework, providing a sufficiently reliable estimation of the blade ultimate loading. The latter aspect is of key importance when design variables implementing passive control methodologies are included in the formulation of the optimization problem. An MDO of a 10 MW wind turbine blade is presented as an applied case study to show the efficacy of the reduced DLB concept.

  6. The Ultimate Factor of Safety for Aircraft and Spacecraft Its History, Applications and Misconceptions

    NASA Technical Reports Server (NTRS)

    Zipay, John J.; Modlin, C. Thomas, Jr.; Larsen, Curtis E.

    2016-01-01

    The ultimate factor of safety (FOSULT) concept used in aircraft and spacecraft has evolved over many decades. Currently an FOSULT 1.5 is the FAR-mandated value for aircraft while an FOSULT of 1.4 has been used in various spacecraft. This paper was motivated by the desire to concisely explain the origins, proper interpretation and application of the ultimate factor of safety concept, since the authors have seen throughout their careers many misconceptions and incorrect applications of this concept. The history of the ultimate factor of safety concept is briefly summarized, the proper application of the factor of safety in aircraft design, structural analysis and operations is covered in detail, examples of limit load exceedance in aircraft and spacecraft are discussed, the evolution of the 1.4 FOSULT for spacecraft is described and some misconceptions regarding the ultimate factor of safety concept are addressed. It is hoped that this paper can be a summary resource for engineers to understand the origin, purpose and proper application of the ultimate factor of safety.

  7. Application of SERS Nanoparticles for Intracellular pH Measurements

    SciTech Connect

    Laurence, T; Talley, C; Colvin, M; Huser, T

    2004-10-21

    We present an alternative approach to optical probes that will ultimately allow us to measure chemical concentrations in microenvironments within cells and tissues. This approach is based on monitoring the surface-enhanced Raman scattering (SERS) response of functionalized metal nanoparticles (50-100 nm in diameter). SERS allows for the sensitive detection of changes in the state of chemical groups attached to individual nanoparticles and small clusters. Here, we present the development of a nanoscale pH meter. The pH response of these nanoprobes is tested in a cell-free medium, measuring the pH of the solution immediately surrounding the nanoparticles. Heterogeneities in the SERS signal, which can result from the formation of small nanoparticle clusters, are characterized using SERS correlation spectroscopy and single particle/cluster SERS spectroscopy. The response of the nanoscale pH meters is tested under a wide range of conditions to approach the complex environment encountered inside living cells and to optimize probe performance.

  8. Optimization and Prediction of Ultimate Tensile Strength in Metal Active Gas Welding.

    PubMed

    Ampaiboon, Anusit; Lasunon, On-Uma; Bubphachot, Bopit

    2015-01-01

    We investigated the effect of welding parameters on ultimate tensile strength of structural steel, ST37-2, welded by Metal Active Gas welding. A fractional factorial design was used for determining the significance of six parameters: wire feed rate, welding voltage, welding speed, travel angle, tip-to-work distance, and shielded gas flow rate. A regression model to predict ultimate tensile strength was developed. Finally, we verified optimization of the process parameters experimentally. We achieved an optimum tensile strength (558 MPa) and wire feed rate, 19 m/min, had the greatest effect, followed by tip-to-work distance, 7 mm, welding speed, 200 mm/min, welding voltage, 30 V, and travel angle, 60°. Shield gas flow rate, 10 L/min, was slightly better but had little effect in the 10-20 L/min range. Tests showed that our regression model was able to predict the ultimate tensile strength within 4%.

  9. Higher order direct model reference adaptive control with generic uniform ultimate boundedness

    NASA Astrophysics Data System (ADS)

    Maity, Arnab; Höcht, Leonhard; Holzapfel, Florian

    2015-10-01

    This paper proposes a new higher order model reference adaptive control (HO-MRAC) approach following direct adaptive control philosophy, which estimates unknown time-varying parameters. This approach leads to a Lyapunov based conventional MRAC update law, augmented by an observer type parameter predictor dynamics. The predictor dynamics are composed of a stable known part, a feedback of the parameter error and unknown higher order parameters, which are updated using a Lyapunov based adaptive design. So, this HO-MRAC can cope with rapidly changing parameters, due to estimation of their time derivatives. Moreover, for stability analysis, a Lyapunov based generic ultimate boundedness theorem is presented, which allows for a computation of separate bounds for each state vector partition. Furthermore, this theorem formulates the explicit specification of transient and ultimate bounds, reaching time on the ultimate bounds and a set of admissible initial conditions. Two challenging illustrative examples demonstrate the effectiveness of the proposed approach.

  10. Proximate analysis, backwards stepwise regression between gross calorific value, ultimate and chemical analysis of wood.

    PubMed

    Telmo, C; Lousada, J; Moreira, N

    2010-06-01

    The gross calorific value (GCV), proximate, ultimate and chemical analysis of debark wood in Portugal were studied, for future utilization in wood pellets industry and the results compared with CEN/TS 14961. The relationship between GCV, ultimate and chemical analysis were determined by multiple regression stepwise backward. The treatment between hardwoods-softwoods did not result in significant statistical differences for proximate, ultimate and chemical analysis. Significant statistical differences were found in carbon for National (hardwoods-softwoods) and (National-tropical) hardwoods in volatile matter, fixed carbon, carbon and oxygen and also for chemical analysis in National (hardwoods-softwoods) for F and (National-tropical) hardwoods for Br. GCV was highly positively related to C (0.79 * * *) and negatively to O (-0.71 * * *). The final independent variables of the model were (C, O, S, Zn, Ni, Br) with R(2)=0.86; F=27.68 * * *. The hydrogen did not contribute statistically to the energy content.

  11. Intra-Beam Scattering, Impedance, and Instabilities in Ultimate Storage Rings

    SciTech Connect

    Bane, Karl; /SLAC

    2012-03-28

    We have investigated collective effects in an ultimate storage ring, i.e. one with diffraction limited emittances in both planes, using PEP-X as an example. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, a 4.5 GeV ring running round beams at 200 mA in 3300 bunches, IBS doubles the emittances to 11.5 pm at the design current. The Touschek lifetime is 11 hours. Impedance driven collective effects tend not to be important since the beam current is relatively low. We have investigated collective effects in PEP-X, an ultimate storage ring, i.e. one with diffraction limited emittances (at one angstrom wavelength) in both planes. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, IBS doubles the emittances to 11.5 pm at the design current of 200 mA, assuming round beams. The Touschek lifetime is quite large in PEP-X, 11.6 hours, and - near the operating point - increases with decreasing emittance. It is, however, a very sensitive function of momentum acceptance. In an ultimate ring like PEP-X impedance driven collective effects tend not to be important since the beam current is relatively low. Before ultimate PEP-X can be realized, the question of how to run a machine with round beams needs serious study. For example, in this report we assumed that the vertical emittance is coupling dominated. It may turn out that using vertical dispersion is a preferable way to generate round beams. The choice will affect IBS and the Touschek effect.

  12. Conception of electron beam-driven subcritical molten salt ultimate safety reactor

    NASA Astrophysics Data System (ADS)

    Abalin, S. S.; Alekseev, P. N.; Ignat'ev, V. V.; Kolyaskin, O. E.; Men'shikov, L. I.; Mostovoi, V. I.; Prusakov, V. N.; Subbotin, S. A.; Krasnykh, A. K.; Popov, Yu. P.; Rudenko, V. T.; Somov, L. N.; Dikansky, N. S.; Novokhatsky, A. V.; Dovbnia, A. N.

    1995-09-01

    This paper is a preliminary sketch of a conception to develop the ``ultimate safety reactor'' using modern reactor and accelerator technologies. This approach would not require a long-range R&D program. The ultimate safety reactor could produce heat and electric energy, expand the production of fuel, or be used for the transmutation of long-lived wastes. The use of the combined double molten salt reactor system allows adequate neutron multiplication to permit using an electron accelerator for the initial neutron flux. The general parameters of such a system are discussed in this paper.

  13. Ultimate doctor liability: a myth of ignorance or myth of control?

    PubMed

    Cashin, Andrew; Carey, Michael; Watson, Ngaire; Clark, Greg; Newman, Claire; Waters, Cheryl D

    2009-01-01

    Ultimate medical doctor responsibility for the care delivered to patients by all professionals is a myth. Legally Lord Denning dismissed the myth in the mid-20th century in England. The assumption that a medical doctor is responsible for the care delivered by nurses has not existed in English and Australian law since that time, and it has been actively refuted. Yet it is a myth that continues to circulate influencing health service, state and federal health policy. For some it is a myth of ignorance and for others it is a means of control. This paper outlines the relevant case law to debunk the myth of ultimate medical doctor control. PMID:19831145

  14. Space simulation ultimate pressure lowered two decades by removal of diffusion pump oil contaminants during operation

    NASA Technical Reports Server (NTRS)

    Buggele, A. E.

    1973-01-01

    The complex problem why large space simulation chambers do not realize the true ultimate vacuum was investigated. Some contaminating factors affecting diffusion pump performance have been identified and some advances in vacuum/distillation/fractionation technology have been achieved which resulted in a two decade or more lower ultimate pressure. Data are presented to show the overall or individual contaminating effect of commonly used phthalate ester plasticizers of 390 to 530 molecular weight on diffusion pump performance. Methods for removing contaminants from diffusion pump silicone oil during operation and reclaiming contaminated oil by high vacuum molecular distillation are described.

  15. pH Optrode Instrumentation

    NASA Technical Reports Server (NTRS)

    Tabacco, Mary Beth; Zhou, Quan

    1995-01-01

    pH-sensitive chromophoric reagents immobilized in porous optical fibers. Optoelectronic instrumentation system measures acidity or alkalinity of aqueous nutrient solution. Includes one or more optrodes, which are optical-fiber chemical sensors, in sense, analogous to electrodes but not subject to some of spurious effects distorting readings taken by pH electrodes. Concept of optrodes also described in "Ethylene-Vapor Optrodes" (KSC-11579). pH optrode sensor head, with lead-in and lead-out optical fibers, convenient for monitoring solutions located away from supporting electronic equipment.

  16. The cost benefit and efficiency of waste water treatment using domestic ponds—the ultimate solution in Southern Africa

    NASA Astrophysics Data System (ADS)

    Ntengwe, F. W.

    Wastewater treatment has become a challenge to most countries in Southern Africa because of the fluctuating economies that have been hit by high levels of debts. The treatment of domestic wastewater using ponds, if carefully utilized, as has been observed in most countries in the world, is the most cost effective means of handling wastewaters. When compared to the conventional use of treatment plants, the ponds have been observed to be the ultimate solution for the countries in Southern Africa especially those that are classified as Highly Indebted Poor Countries (HIPC) because of little or no operating costs associated with the treatment. The study conducted on Kitwe Waste Water Treatment Ponds to evaluate the cost benefit and efficiencies has revealed low levels of operating cost and high removal efficiencies of oxygen demanding wastes (BOD removal of 86% and TSS removal of 75%), pH values ranged from 7 to 8 indicating an increasing alkalinity from facultative to maturation ponds while other parameters such as nitrates, phosphates and temperature were found to be within acceptable levels thereby releasing effluent that makes the environment sustainable. The overall social benefit was found to be much higher than the operating costs.

  17. Making pH Tangible.

    ERIC Educational Resources Information Center

    McIntosh, Elizabeth; Moss, Robert

    1995-01-01

    Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)

  18. The Ultimate Flag Games Curriculum: An Answer to a Participation Problem

    ERIC Educational Resources Information Center

    Bell, Martie

    2011-01-01

    In response to a lack of active participation by students in physical education, the Ultimate Flag Games curriculum was created and has thrived in the decades since its inception. The curriculum has been successful at the middle school, high school, and higher education levels. This article introduced the curriculum, different games, and rules and…

  19. 75 FR 60133 - Agency Information Collection Activities: Declaration of Ultimate Consignee That Articles Were...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... Ultimate Consignee That Articles Were Exported for Temporary Scientific or Educational Purposes AGENCY: U.S... Consignee That Articles Were Exported for Temporary Scientific or Educational Purposes. This request for... That Articles Were Exported for Temporary Scientific or Educational Purposes. OMB Number:...

  20. 78 FR 69101 - Agency Information Collection Activities: Declaration of the Ultimate Consignee That Articles...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... Ultimate Consignee That Articles Were Exported for Temporary Scientific or Educational Purposes AGENCY: U.S... Consignee that Articles were Exported for Temporary Scientific or Educational Purposes. This request for... Consignee that Articles were Exported for Temporary Scientific or Educational Purposes. OMB Number:...

  1. Qualtum cosmics-and-chaotics--the ultimate tortoise in physics and modern medicine.

    PubMed

    Kothari, M V; Mehta, L A

    1997-01-01

    Qualtum cosmics is the qualitative opposite of quantum mechanics. The flip-side of qualtum cosmics is qualtum chaotics, the two governing much of what is seen as inscrutable in medicine. The Ultimate (Last) Tortoise is close to Einsteinean idea of a Unified Theory, a single concept that can explain whatsoever there is in physics, (and in medicine, or what have you).

  2. 26 CFR 48.6427-11 - Kerosene; claims by registered ultimate vendors (blending).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Kerosene; claims by registered ultimate vendors (blending). 48.6427-11 Section 48.6427-11 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... same form as the model certificate provided in paragraph (e)(2)(iii) of this section, and contains...

  3. Prisoner Fasting as Symbolic Speech: The Ultimate Speech-Action Test.

    ERIC Educational Resources Information Center

    Sneed, Don; Stonecipher, Harry W.

    The ultimate test of the speech-action dichotomy, as it relates to symbolic speech to be considered by the courts, may be the fasting of prison inmates who use hunger strikes to protest the conditions of their confinement or to make political statements. While hunger strikes have been utilized by prisoners for years as a means of protest, it was…

  4. 7 CFR 4280.21 - Eligible REDG Ultimate Recipients and Projects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Eligible REDG Ultimate Recipients and Projects. 4280.21 Section 4280.21 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs...

  5. 7 CFR 4280.21 - Eligible REDG Ultimate Recipients and Projects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Eligible REDG Ultimate Recipients and Projects. 4280.21 Section 4280.21 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs...

  6. 19 CFR 142.17a - One consolidated entry summary for multiple ultimate consignees.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false One consolidated entry summary for multiple... Documentation § 142.17a One consolidated entry summary for multiple ultimate consignees. (a) Applicability. The port director may permit a broker as nominal consignee to file a consolidated entry summary in his...

  7. 19 CFR 142.17a - One consolidated entry summary for multiple ultimate consignees.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false One consolidated entry summary for multiple... Documentation § 142.17a One consolidated entry summary for multiple ultimate consignees. (a) Applicability. The port director may permit a broker as nominal consignee to file a consolidated entry summary in his...

  8. Ultimate biochemical oxygen demand in semi-intensively managed shrimp pond waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three independent studies were conducted to quantified ultimate biochemical oxygen demand (UBOD) and the corresponding decomposition rate constant for production pond (average 21.5 ha each) waters and effluents on six semi-intensively managed marine shrimp (Litopenaeus vannamei) farms in Honduras. S...

  9. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  10. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  11. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  12. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  13. 7 CFR 4280.15 - Ultimate Recipient Projects eligible for Rural Economic Development Loan funding.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGRICULTURE LOANS AND GRANTS Rural Economic Development Loan and Grant Programs § 4280.15 Ultimate Recipient Projects eligible for Rural Economic Development Loan funding. An Intermediary may receive REDL funds only... Recipient to finance financially viable economic development or job creation Projects in a Rural Area....

  14. 15 CFR 748.11 - Statement by Ultimate Consignee and Purchaser.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Statement by Ultimate Consignee and Purchaser. 748.11 Section 748.11 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT...

  15. 22 CFR 123.9 - Country of ultimate destination and approval of reexports or retransfers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Country of ultimate destination and approval of reexports or retransfers. 123.9 Section 123.9 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN... government of a NATO country, or the governments of Australia, Japan, New Zealand, or South Korea,...

  16. Age of Onset and Nativelike L2 Ultimate Attainment of Morphosyntactic and Phonetic Intuition

    ERIC Educational Resources Information Center

    Abrahamsson, Niclas

    2012-01-01

    Research has consistently shown there is a negative correlation between age of onset (AO) of acquisition and ultimate attainment (UA) of either pronunciation or grammar in a second language (L2). A few studies have indeed reported nativelike behavior in some postpuberty learners with respect to either phonetics/phonology or morphosyntax, a result…

  17. L2 and L3 Ultimate Attainment: An Investigation of Two Parameters

    ERIC Educational Resources Information Center

    Hermas, Abdelkader

    2014-01-01

    This study considers the upper limit of ultimate attainment in the L2 French and L3 English of trilingual learners. The learners are native speakers of Moroccan Arabic who started learning L2 French at eight and L3 English at 16. They are advanced in both languages. Four constructions representing the verb movement and null subject parameter were…

  18. Ultimate Stresses Developed by 24S-T Sheet in Incomplete Diagonal Tension

    NASA Technical Reports Server (NTRS)

    Kuhn, Paul

    1941-01-01

    Tests were made on 18 shear panels of 24S-T aluminum alloy to verify the dependence of the ultimate stress on the degree of development of the diagonal-tension field. Tests were made on two thicknesses of sheet with the sheet either clamped between the flange angle or riveted to the outside of the angles.

  19. The Starting Age and Ultimate Attainment of English Learning in the Palestinian Context

    ERIC Educational Resources Information Center

    Dwaik, Raghad; Shehadeh, Adnan

    2015-01-01

    The starting age of foreign language learning has been a controversial issue since the second half of the 20th century. Despite this long time, definite answers have not been found regarding the different aspects of the age issue, i.e., its influence on rate, route and ultimate attainment. Many researchers have explored the influence of age on the…

  20. Student's Ultimate Career Coursework, Employment, & Student Services Handbook. "SUCCESS Handbook" Final Report.

    ERIC Educational Resources Information Center

    Foothill-De Anza Community Coll. District, Cupertino, CA. Occupational Training Inst.

    The Student's Ultimate Career Coursework, Employment and Student Services (SUCCESS) Handbook project was undertaken to identify student support services available through the California Community Colleges (CCC), increase student retention among special needs vocational education students, and identify common barriers to employment. The project…

  1. 78 FR 55117 - Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... COMMISSION Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide AGENCY: Nuclear Regulatory... Nuclear Power Plants.'' This regulatory guide (RG) describes methods and procedures acceptable to the NRC staff that nuclear power plant facility licensees and applicants may use to implement general...

  2. 26 CFR 48.6427-10 - Kerosene; claims by registered ultimate vendors (blocked pumps).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (blocked pumps). 48.6427-10 Section 48.6427-10 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE...; claims by registered ultimate vendors (blocked pumps). (a) Overview. This section provides rules under... allowed by section 6427(l)(5)(B)(i). These claims relate to kerosene sold from a blocked pump....

  3. 26 CFR 48.6427-10 - Kerosene; claims by registered ultimate vendors (blocked pumps).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (blocked pumps). 48.6427-10 Section 48.6427-10 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE...; claims by registered ultimate vendors (blocked pumps). (a) Overview. This section provides rules under... allowed by section 6427(l)(5)(B)(i). These claims relate to kerosene sold from a blocked pump....

  4. 26 CFR 48.6427-10 - Kerosene; claims by registered ultimate vendors (blocked pumps).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (blocked pumps). 48.6427-10 Section 48.6427-10 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE...; claims by registered ultimate vendors (blocked pumps). (a) Overview. This section provides rules under... allowed by section 6427(l)(5)(B)(i). These claims relate to kerosene sold from a blocked pump....

  5. Adjudicating pathological criminal incapacity within a climate of ultimate issue barriers: a comparative perspective.

    PubMed

    Stevens, Geert Philip

    2015-01-01

    Mental health experts are increasingly being utilised by the criminal justice system to provide assistance to courts during the assessment of issues falling beyond the knowledge and/or experience of the courts. A particular domain where the assistance of qualified psychiatrists and psychologists is becoming essential is where the defence of pathological criminal incapacity falls to be assessed. Mental health professionals testifying during trials where the defence of pathological criminal incapacity is raised will present opinion evidence which is one of the exceptions to the rule of inadmissibility of opinion evidence. Mental health professionals providing their opinion evidence are, however, prohibited from expressing opinions on so-called "ultimate issues" upon which only the court may ultimately rule upon. The latter rule is also commonly known in practice as the "ultimate issue" rule which presents multifaceted challenges in respect of the application of the defence of pathological criminal incapacity. In this article, the author assesses the application of the ultimate issue rule with reference to the defence of pathological criminal incapacity as it operates within the South African criminal law context. A comparative analysis is also provided with reference to the rule as it operates in the United States of America and more specifically Federal Rule 704. It is concluded that the ultimate issue rule unnecessarily restricts testimony provided by mental health professionals as such placing a barrier on such evidence. As such, it is argued that the rule is superfluous as it remains within the discretion of the trier of fact to decide as to what weight to attach to such evidence.

  6. Adjudicating pathological criminal incapacity within a climate of ultimate issue barriers: a comparative perspective.

    PubMed

    Stevens, Geert Philip

    2015-01-01

    Mental health experts are increasingly being utilised by the criminal justice system to provide assistance to courts during the assessment of issues falling beyond the knowledge and/or experience of the courts. A particular domain where the assistance of qualified psychiatrists and psychologists is becoming essential is where the defence of pathological criminal incapacity falls to be assessed. Mental health professionals testifying during trials where the defence of pathological criminal incapacity is raised will present opinion evidence which is one of the exceptions to the rule of inadmissibility of opinion evidence. Mental health professionals providing their opinion evidence are, however, prohibited from expressing opinions on so-called "ultimate issues" upon which only the court may ultimately rule upon. The latter rule is also commonly known in practice as the "ultimate issue" rule which presents multifaceted challenges in respect of the application of the defence of pathological criminal incapacity. In this article, the author assesses the application of the ultimate issue rule with reference to the defence of pathological criminal incapacity as it operates within the South African criminal law context. A comparative analysis is also provided with reference to the rule as it operates in the United States of America and more specifically Federal Rule 704. It is concluded that the ultimate issue rule unnecessarily restricts testimony provided by mental health professionals as such placing a barrier on such evidence. As such, it is argued that the rule is superfluous as it remains within the discretion of the trier of fact to decide as to what weight to attach to such evidence. PMID:25681851

  7. A survey of beef muscle color and pH.

    PubMed

    Page, J K; Wulf, D M; Schwotzer, T R

    2001-03-01

    The objectives of this study were to define a beef carcass population in terms of muscle color, ultimate pH, and electrical impedance; to determine the relationships among color, pH, and impedance and with other carcasses characteristics; and to determine the effect of packing plant, breed type, and sex class on these variables. One thousand beef carcasses were selected at three packing plants to match the breed type, sex class, marbling score, dark-cutting discount, overall maturity, carcass weight, and yield grade distributions reported for the U.S. beef carcass population by the 1995 National Beef Quality Audit. Data collected on these carcasses included USDA quality and yield grade data and measurements of muscle color (L*, a*, b*), muscle pH, and electrical impedance of the longissimus muscle. About one-half (53.1%) of the carcasses fell within a muscle pH range of 5.40 to 5.49, and 81.3% of the carcasses fell within a longissimus muscle pH range of 5.40 to 5.59. A longissimus muscle pH of 5.87 was the approximate cut-off between normal and dark-cutting carcasses. Frequency distributions indicated that L* values were normally distributed, whereas a* and b* values were abnormally distributed (skewed because of a longer tail for lower values, a tail corresponding with dark-cutting carcasses). Electrical impedance was highly variable among carcasses but was not highly related to any other variable measured. Color measurements (L*, a*, b*) were correlated (P < 0.05) with lean maturity score (-.58, -.31, and -.43, respectively) and with muscle pH (-.40, -.58, and -.56, respectively). In addition, fat thickness was correlated with muscle pH and color (P < 0.05). There was a threshold at approximately .76 cm fat thickness, below which carcasses had higher muscle pH values and lower colorimeter readings. Steer carcasses (L* = 39.62, a* = 25.20, and b* = 11.03) had slightly higher colorimeter readings (P < 0.05) than heifer carcasses (L* = 39.20, a* = 24.78, and b

  8. A survey of beef muscle color and pH.

    PubMed

    Page, J K; Wulf, D M; Schwotzer, T R

    2001-03-01

    The objectives of this study were to define a beef carcass population in terms of muscle color, ultimate pH, and electrical impedance; to determine the relationships among color, pH, and impedance and with other carcasses characteristics; and to determine the effect of packing plant, breed type, and sex class on these variables. One thousand beef carcasses were selected at three packing plants to match the breed type, sex class, marbling score, dark-cutting discount, overall maturity, carcass weight, and yield grade distributions reported for the U.S. beef carcass population by the 1995 National Beef Quality Audit. Data collected on these carcasses included USDA quality and yield grade data and measurements of muscle color (L*, a*, b*), muscle pH, and electrical impedance of the longissimus muscle. About one-half (53.1%) of the carcasses fell within a muscle pH range of 5.40 to 5.49, and 81.3% of the carcasses fell within a longissimus muscle pH range of 5.40 to 5.59. A longissimus muscle pH of 5.87 was the approximate cut-off between normal and dark-cutting carcasses. Frequency distributions indicated that L* values were normally distributed, whereas a* and b* values were abnormally distributed (skewed because of a longer tail for lower values, a tail corresponding with dark-cutting carcasses). Electrical impedance was highly variable among carcasses but was not highly related to any other variable measured. Color measurements (L*, a*, b*) were correlated (P < 0.05) with lean maturity score (-.58, -.31, and -.43, respectively) and with muscle pH (-.40, -.58, and -.56, respectively). In addition, fat thickness was correlated with muscle pH and color (P < 0.05). There was a threshold at approximately .76 cm fat thickness, below which carcasses had higher muscle pH values and lower colorimeter readings. Steer carcasses (L* = 39.62, a* = 25.20, and b* = 11.03) had slightly higher colorimeter readings (P < 0.05) than heifer carcasses (L* = 39.20, a* = 24.78, and b

  9. Group 2 PH: Medical Therapy.

    PubMed

    Guazzi, Marco; Labate, Valentina

    2016-01-01

    Pulmonary hypertension (PH) secondary to left heart disease, classified as Group 2, is a widely underestimated target of therapy. Prevention and treatment of initial subclinical stages are not valued as a priority in the management of this chronic disease population, whereas attention is high for PH consequences in patients with advanced heart failure (HF) requiring a left ventricular mechanical assist device or heart transplant candidates. Even so, there is a growing interest toward the evidence of a clinical and prognostic role of PH in the elderly populations and in HF with preserved ejection fraction (HFpEF). Certainly, along with a prevalence definition not yet defined, the search for effective pharmacological approaches that might favorably affect the aging process and the natural history of HFpEF from earlier stages is not an easy task. Pharmacological studies that have tested some traditional pulmonary arterial hypertension approved drugs (i.e., prostanoids and endothelin-1 receptor blockers) primarily in PH and HF with reduced ejection fraction have not been positive, especially because of concomitant side effects, i.e., systemic hypotension, fluid retention and hepatic toxicity. In recent years, interest has moved toward drugs overexpressing the nitric oxide (NO)-cyclic guanosine monophosphate pathway with recent availability of well-tolerated selective pulmonary vasodilators, such as phosphodiesterase type 5 inhibitors and guanylate cyclase stimulators. Single center studies performed with these drugs have shown good tolerability and safety profile providing alternating hemodynamic results mainly because of recruitment of patients at different stages of the pulmonary vascular disease. Nonetheless, the overexpression of NO pathway appears to remain the most solid background for targeting lung microvessel dysfunction and treating RV dysfunction since the earliest stages of the disease. PMID:27389809

  10. The Methods Behind PH WINS

    PubMed Central

    Leider, Jonathon P.; Bharthapudi, Kiran; Pineau, Vicki; Liu, Lin; Harper, Elizabeth

    2015-01-01

    The Public Health Workforce Interests and Needs Survey (PH WINS) has yielded the first-ever nationally representative sample of state health agency central office employees. The survey represents a step forward in rigorous, systematic data collection to inform the public health workforce development agenda in the United States. PH WINS is a Web-based survey and was developed with guidance from a panel of public health workforce experts including practitioners and researchers. It draws heavily from existing and validated items and focuses on 4 main areas: workforce perceptions about training needs, workplace environment and job satisfaction, perceptions about national trends, and demographics. This article outlines the conceptualization, development, and implementation of PH WINS, as well as considerations and limitations. It also describes the creation of 2 new data sets that will be available in public use for public health officials and researchers—a nationally representative data set for permanently employed state health agency central office employees comprising over 10 000 responses, and a pilot data set with approximately 12 000 local and regional health department staff responses. PMID:26422490

  11. Advanced Biotelemetry Systems for Space Life Sciences: PH Telemetry

    NASA Technical Reports Server (NTRS)

    Hines, John W.; Somps, Chris; Ricks, Robert; Kim, Lynn; Connolly, John P. (Technical Monitor)

    1995-01-01

    The SENSORS 2000! (S2K!) program at NASA's Ames Research Center is currently developing a biotelemetry system for monitoring pH and temperature in unrestrained subjects. This activity is part of a broader scope effort to provide an Advanced Biotelemetry System (ABTS) for use in future space life sciences research. Many anticipated research endeavors will require biomedical and biochemical sensors and related instrumentation to make continuous inflight measurements in a variable-gravity environment. Since crew time is limited, automated data acquisition, data processing, data storage, and subject health monitoring are required. An automated biochemical and physiological data acquisition system based on non invasive or implantable biotelemetry technology will meet these requirements. The ABTS will ultimately acquire a variety of physiological measurands including temperature, biopotentials (e.g. ECG, EEG, EMG, EOG), blood pressure, flow and dimensions, as well as chemical and biological parameters including pH. Development activities are planned in evolutionary, leveraged steps. Near-term activities include 1) development of a dual channel pH/temperature telemetry system, and 2) development of a low bandwidth, 4-channel telemetry system, that measures temperature, heart rate, pressure, and pH. This abstract describes the pH/temperature telemeter.

  12. Ultimate kinematic characteristics of rail electromagnetic launchers with metal armatures in an external magnetic field

    NASA Astrophysics Data System (ADS)

    Stankevich, S. V.; Shvetsov, G. A.

    2014-09-01

    This paper presents the results of numerical simulation of the Joule heating of the armature and rails in rail launchers of metal bodies with one or two augmenting rails generating an external magnetic field. The ultimate projectile velocity is calculated under the assumption that the Joule heating of the armature and rails during acceleration does not exceed the melting temperature of the materials of which they are made. It is shown that, with an appropriate choice of the position of the coils generating the augmenting magnetic field with respect to the launcher channel and the current magnitude in them, the heat load on the rails and armature in electromagnetic launchers of solids can be substantially reduced and the ultimate kinematic characteristics of these launchers in crisis-free regimes can be considerably increased.

  13. Multiple proximate and ultimate causes of natal dispersal in white-tailed deer

    USGS Publications Warehouse

    Long, E.S.; Diefenbach, D.R.; Rosenberry, C.S.; Wallingford, B.D.

    2008-01-01

    Proximate and ultimate causes of dispersal in vertebrates vary, and relative importance of these causes is poorly understood. Among populations, inter- and intrasexual social cues for dispersal are thought to reduce inbreeding and local mate competition, respectively, and specific emigration cue may affect dispersal distance, such that inbreeding avoidance dispersal tends to be farther than dispersal to reduce local competition. To investigate potential occurrence of multiple proximate and ultimate causes of dispersal within populations, we radio-marked 363 juvenile male white-tailed deer (Odocoileus virginianus) in 2 study areas in Pennsylvania. Natal dispersal probability and distance were monitored over a 3-year period when large-scale management changes reduced density of adult females and increased density of adult males. Most dispersal (95-97%) occurred during two 12-week periods: spring, when yearling males still closely associate with related females, and prior to fall breeding season, when yearling males closely associate with other breeding-age males. Following changes to sex and age structure that reduced potential for inbreeding and increased potential for mate competition, annual dispersal probability did not change; however, probability of spring dispersal decreased, whereas probability of fall dispersal increased. Spring dispersal distances were greater than fall dispersal distances, suggesting that adaptive inbreeding avoidance dispersal requires greater distance than mate competition dispersal where opposite-sex relatives are philopatric and populations are not patchily distributed. Both inbreeding avoidance and mate competition are important ultimate causes of dispersal of white-tailed deer, but ultimate motivations for dispersal are proximately cued by different social mechanisms and elicit different responses in dispersers.

  14. The ultimate safe (US) Reactor: A concept for the third millenium

    SciTech Connect

    Gat, U.

    1986-01-01

    The Ultimate Safe (U.S.) Reactor is based on a novel safety concept. Fission products in the reactor are allowed to accumulate only to a level at which they would constitute a harmless source term. Removal of fission products also removes the decay heat - the driving force for the source term. The reactor has no excess criticality and is controlled by the reactivity temperature coefficient. Safety is inherent and passive. Waste is removed from the site promptly.

  15. Results from large scale ultimate strength tests of K-braced jacket frame structures

    SciTech Connect

    Bolt, H.M.

    1995-12-01

    Phase 2 of the JIP Frames Project included four large scale collapse tests of K-braced frames in which both gap and overlap K joints were the critical components. The results are presented in this paper. The local failure modes differed from typical isolated component tests, yet were representative of structural damage observed following Hurricane Andrew. The frame test results therefore provide important insight to the ultimate response of offshore jacket structures.

  16. An investigation into geometry and microstructural effects upon the ultimate tensile strengths of butt welds

    NASA Technical Reports Server (NTRS)

    Gordon, Stephen S.

    1992-01-01

    A mathematical theory was evaluated empirically. This theory predicts weld ultimate tensile strength based on material properties and fusion line angles, mismatch, peaking, and weld widths. Welds were made on 1/4 and 1/2 in. aluminum 2219-T87, their geometries were measured, they were tensile tested, and these results were compared to theoretical predictions. Statistical analysis of results was performed to evaluate correlation of theory to results for many different categories of weld geometries.

  17. The Potential of an Ultimate Storage Ring for Future Light Sources

    SciTech Connect

    Bei, M; Cai, Y; Elleaume, P; Gerig, R; Harkay, K; Emery, L; Hutton, A; Hettel, R; Nagaoka, R; Robin, D; Steier, C

    2010-10-01

    This paper is the report of the working group on Ultimate Storage Rings at the Department of Energy's Basic Energy Sciences Workshop on Physics of Future Light Sources, which took place in Gaithersburg, Maryland on September 15–17, 2009. In this report we address the accelerator design issues related to the next generation of storage ring light sources, deemed “ultimate” storage rings. In our estimation, storage rings have the potential to provide an increase in photon brightness and coherent flux that is two orders of magnitude above that projected for rings currently under construction. In addition to photon brightness and coherent flux, we discuss other directions, such as shorter pulses, tailored bunches, and partial lasing, in which rings could evolve. For the most part we envision ultimate storage rings as an evolutionary advance from existing rings that faces no fundamental technological obstacles. Nevertheless we identify several important areas of R&D that should be pursued to enable the realization of the full potential of ultimate ring light sources.

  18. Optimization and Prediction of Ultimate Tensile Strength in Metal Active Gas Welding

    PubMed Central

    Ampaiboon, Anusit; Lasunon, On-Uma; Bubphachot, Bopit

    2015-01-01

    We investigated the effect of welding parameters on ultimate tensile strength of structural steel, ST37-2, welded by Metal Active Gas welding. A fractional factorial design was used for determining the significance of six parameters: wire feed rate, welding voltage, welding speed, travel angle, tip-to-work distance, and shielded gas flow rate. A regression model to predict ultimate tensile strength was developed. Finally, we verified optimization of the process parameters experimentally. We achieved an optimum tensile strength (558 MPa) and wire feed rate, 19 m/min, had the greatest effect, followed by tip-to-work distance, 7 mm, welding speed, 200 mm/min, welding voltage, 30 V, and travel angle, 60°. Shield gas flow rate, 10 L/min, was slightly better but had little effect in the 10–20 L/min range. Tests showed that our regression model was able to predict the ultimate tensile strength within 4%. PMID:26491719

  19. Alkaline pH sensor molecules.

    PubMed

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range.

  20. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging

    PubMed Central

    Burdikova, Zuzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D.; Wilkinson, Martin G.; Panek, Jiri; Auty, Mark A. E.; Periasamy, Ammasi; Sheehan, Jeremiah J.

    2015-01-01

    Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM). In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening. PMID:25798136

  1. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging.

    PubMed

    Burdikova, Zuzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G; Panek, Jiri; Auty, Mark A E; Periasamy, Ammasi; Sheehan, Jeremiah J

    2015-01-01

    Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM). In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.

  2. The pH of antiseptic cleansers

    PubMed Central

    Kulthanan, Kanokvalai; Varothai, Supenya; Nuchkull, Piyavadee

    2014-01-01

    Background Daily bathing with antiseptic cleansers are proposed by some physicians as an adjunctive management of atopic dermatitis (AD). As atopic skin is sensitive, selection of cleansing products becomes a topic of concern. Objective Our purpose is to evaluate the pH of various antiseptic body cleansers to give an overview for recommendation to patients with AD. Methods Commonly bar and liquid cleansers consisted of antiseptic agents were measured for pH using pH meter and pH-indicator strips. For comparison, mild cleansers and general body cleansers were also measured. Results All cleansing bars had pH 9.8-11.3 except syndet bar that had neutral pH. For liquid cleansers, three cleansing agents had pH close to pH of normal skin, one of antiseptic cleansers, one of mild cleansers and another one of general cleansers. The rest of antiseptic cleansers had pH 8.9-9.6 while mild cleansers had pH 6.9-7.5. Syndet liquid had pH 7 and general liquid cleansers had pH 9.6. Conclusion The pH of cleanser depends on composition of that cleanser. Adding antiseptic agents are not the only factor determining variation of pH. Moreover, benefit of antiseptic properties should be considered especially in cases of infected skin lesions in the selection of proper cleansers for patients with AD. PMID:24527408

  3. Acid loading test (pH)

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  4. Engineering Ultimate Self-Protection in Autonomic Agents for Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Sterritt, Roy; Hinchey, Mike

    2005-01-01

    NASA's Exploration Initiative (EI) will push space exploration missions to the limit. Future missions will be required to be self-managing as well as self-directed, in order to meet the challenges of human and robotic space exploration. We discuss security and self protection in autonomic agent based-systems, and propose the ultimate self-protection mechanism for such systems-self-destruction. Like other metaphors in Autonomic Computing, this is inspired by biological systems, and is the analog of biological apoptosis. Finally, we discus the role it might play in future NASA space exploration missions.

  5. Lava ultimate resin nano ceramic for CAD/ CAM: customization case study.

    PubMed

    Koller, M; Arnetzl, G V; Holly, L; Arnetzl, G

    2012-01-01

    Lava Ultimate Resin Nano Ceramic (RNC) blocks are innovative new CAD/CAM materials that make it possible to achieve superior esthetic results in easy steps. The blocks are made of nano ceramic particles embedded in a highly cured resin matrix. Therefore, composite materials can be used to characterize and adjust resin nano ceramic restorations after milling. The milled RNC restorations can be individualized intra-orally or extra-orally, either before or after insertion. Unlike conventional ceramic restorations, customization and glaze firing is neither necessary nor possible with RNC restorations. This opens up the opportunity for intraoral individualization and adaptation of the restorations.

  6. Physiological and Fatigue Responses Associated With Male and Mixed-Gender Ultimate Frisbee Game Play.

    PubMed

    Scanlan, Aaron T; Kean, Crystal O; Humphries, Brendan J; Dalbo, Vincent J

    2015-09-01

    The aims of this study were to describe the physiological and fatigue responses associated with indoor Ultimate Frisbee game play, compare exercise intensities attained to current activity guidelines, and compare responses between male and mixed-gender game formats. A between-subjects (game format) repeated-measures (time points) observational experimental design was used. Subjects competed in male (n = 10; age: 26.3 ± 7.6 years) or mixed-gender (males: n = 4; 28.5 ± 5.7 years; females: n = 6; 28.3 ± 8.1 years) indoor Ultimate Frisbee game play. Games consisted of 10-minute halves, with heart rate (HR), blood lactate concentration ([BLa]), rating of perceived exertion, and 5-m and 20-m sprint times measured. Durations spent in HR-derived intensity zones and sprint decrements were calculated across games. Mixed-gender game play produced significantly (p ≤ 0.05) higher relative HR (94.3 ± 5.1% vs. 89.6 ± 4.8% HRmax) and [BLa] (8.31 ± 2.22 mmol·L vs. 4.68 ± 1.89 mmol·L) than male game play. Significantly (p ≤ 0.05) longer durations were spent at vigorous (male: 60.2 ± 26.1%; mixed-gender: 36.8 ± 34.8%) and near-maximal (male: 31.6 ± 27.6%; mixed-gender: 58.6 ± 37.7%) exercise intensities than moderate (3.9-7.2%), light (0.7-1.0%), and very light (0-0.1%) intensities in both formats. Limited physiological and sprint fatigue was apparent across games. Subjects primarily performed at vigorous and near-maximal intensities during Ultimate Frisbee. The greater physiological demands encountered during mixed-gender game play might be attributed to underlying gender-mediated cardiovascular differences. These findings support the efficacy of Ultimate Frisbee as a prescriptive exercise tool for health benefit.

  7. Lava ultimate resin nano ceramic for CAD/ CAM: customization case study.

    PubMed

    Koller, M; Arnetzl, G V; Holly, L; Arnetzl, G

    2012-01-01

    Lava Ultimate Resin Nano Ceramic (RNC) blocks are innovative new CAD/CAM materials that make it possible to achieve superior esthetic results in easy steps. The blocks are made of nano ceramic particles embedded in a highly cured resin matrix. Therefore, composite materials can be used to characterize and adjust resin nano ceramic restorations after milling. The milled RNC restorations can be individualized intra-orally or extra-orally, either before or after insertion. Unlike conventional ceramic restorations, customization and glaze firing is neither necessary nor possible with RNC restorations. This opens up the opportunity for intraoral individualization and adaptation of the restorations. PMID:22891419

  8. Assembly of Customized TAL Effectors Through Advanced ULtiMATE System.

    PubMed

    Yang, Junjiao; Guo, Shengjie; Yuan, Pengfei; Wei, Wensheng

    2016-01-01

    Transcription activator-like effectors (TALEs) have been widely applied in gene targeting. Here we describe an advanced ULtiMATE (USER-based Ligation-Mediated Assembly of TAL Effector) system that utilizes USER fusion technique and archive of 512 tetramer templates to achieve highly efficient construction of TALEs, which takes only half a day to accomplish the assembly of any given TALE construct. This system is also suitable for large-scale assembly of TALENs and any other TALE-based constructions. PMID:26443213

  9. Assembly of Customized TAL Effectors Through Advanced ULtiMATE System.

    PubMed

    Yang, Junjiao; Guo, Shengjie; Yuan, Pengfei; Wei, Wensheng

    2016-01-01

    Transcription activator-like effectors (TALEs) have been widely applied in gene targeting. Here we describe an advanced ULtiMATE (USER-based Ligation-Mediated Assembly of TAL Effector) system that utilizes USER fusion technique and archive of 512 tetramer templates to achieve highly efficient construction of TALEs, which takes only half a day to accomplish the assembly of any given TALE construct. This system is also suitable for large-scale assembly of TALENs and any other TALE-based constructions.

  10. 15 CFR Supplement No. 3 to Part 748 - BIS-711, Statement by Ultimate Consignee and Purchaser Instructions

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false BIS-711, Statement by Ultimate Consignee and Purchaser Instructions No. Supplement No. 3 to Part 748 Commerce and Foreign Trade Regulations... Pt. 748, Supp. 3 Supplement No. 3 to Part 748—BIS-711, Statement by Ultimate Consignee and...

  11. 15 CFR Supplement No. 3 to Part 748 - BIS-711, Statement by Ultimate Consignee and Purchaser Instructions

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false BIS-711, Statement by Ultimate Consignee and Purchaser Instructions No. Supplement No. 3 to Part 748 Commerce and Foreign Trade Regulations... Pt. 748, Supp. 3 Supplement No. 3 to Part 748—BIS-711, Statement by Ultimate Consignee and...

  12. 15 CFR Supplement No. 3 to Part 748 - BIS-711, Statement by Ultimate Consignee and Purchaser Instructions

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false BIS-711, Statement by Ultimate Consignee and Purchaser Instructions No. Supplement No. 3 to Part 748 Commerce and Foreign Trade Regulations... Pt. 748, Supp. 3 Supplement No. 3 to Part 748—BIS-711, Statement by Ultimate Consignee and...

  13. 15 CFR Supplement No. 3 to Part 748 - BIS-711, Statement by Ultimate Consignee and Purchaser Instructions

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false BIS-711, Statement by Ultimate Consignee and Purchaser Instructions No. Supplement No. 3 to Part 748 Commerce and Foreign Trade Regulations... Pt. 748, Supp. 3 Supplement No. 3 to Part 748—BIS-711, Statement by Ultimate Consignee and...

  14. 15 CFR Supplement No. 3 to Part 748 - BIS-711, Statement by Ultimate Consignee and Purchaser Instructions

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false BIS-711, Statement by Ultimate Consignee and Purchaser Instructions No. Supplement No. 3 to Part 748 Commerce and Foreign Trade Regulations... Pt. 748, Supp. 3 Supplement No. 3 to Part 748—BIS-711, Statement by Ultimate Consignee and...

  15. Rain pH estimation based on the particulate matter pollutants and wet deposition study.

    PubMed

    Singh, Shweta; Elumalai, Suresh Pandian; Pal, Asim Kumar

    2016-09-01

    In forecasting of rain pH, the changes caused by particulate matter (PM) are generally neglected. In regions of high PM concentration like Dhanbad, the role of PM in deciding the rain pH becomes important. Present work takes into account theoretical prediction of rain pH by two methods. First method considers only acid causing gases (ACG) like CO2, SO2 and NOx in pH estimation, whereas, second method additionally accounts for effect of PM (ACG-PM). In order to predict the rain pH, site specific deposited dust that represents local PM was studied experimentally for its impact on pH of neutral water. After incorporation of PM correction factor, it was found that, rain pH values estimated were more representative of the observed ones. Fractional bias (FB) for the ACG-PM method reduced to values of the order of 10(-2) from those with order of 10(-1) for the ACG method. The study confirms neutralization of rain acidity by PM. On account of this, rain pH was found in the slightly acidic to near neutral range, despite of the high sulfate flux found in rain water. Although, the safer range of rain pH blurs the severity of acid rain from the picture, yet huge flux of acidic and other ions get transferred to water bodies, soil and ultimately to the ground water system. Simple use of rain pH for rain water quality fails to address the issues of its increased ionic composition due to the interfering pollutants and thus undermines severity of pollutants transferred from air to rain water and then to water bodies and soil. PMID:27139302

  16. Rain pH estimation based on the particulate matter pollutants and wet deposition study.

    PubMed

    Singh, Shweta; Elumalai, Suresh Pandian; Pal, Asim Kumar

    2016-09-01

    In forecasting of rain pH, the changes caused by particulate matter (PM) are generally neglected. In regions of high PM concentration like Dhanbad, the role of PM in deciding the rain pH becomes important. Present work takes into account theoretical prediction of rain pH by two methods. First method considers only acid causing gases (ACG) like CO2, SO2 and NOx in pH estimation, whereas, second method additionally accounts for effect of PM (ACG-PM). In order to predict the rain pH, site specific deposited dust that represents local PM was studied experimentally for its impact on pH of neutral water. After incorporation of PM correction factor, it was found that, rain pH values estimated were more representative of the observed ones. Fractional bias (FB) for the ACG-PM method reduced to values of the order of 10(-2) from those with order of 10(-1) for the ACG method. The study confirms neutralization of rain acidity by PM. On account of this, rain pH was found in the slightly acidic to near neutral range, despite of the high sulfate flux found in rain water. Although, the safer range of rain pH blurs the severity of acid rain from the picture, yet huge flux of acidic and other ions get transferred to water bodies, soil and ultimately to the ground water system. Simple use of rain pH for rain water quality fails to address the issues of its increased ionic composition due to the interfering pollutants and thus undermines severity of pollutants transferred from air to rain water and then to water bodies and soil.

  17. Ultimate Osmosis Engineered by the Pore Geometry and Functionalization of Carbon Nanostructures

    PubMed Central

    Song, Zhigong; Xu, Zhiping

    2015-01-01

    Osmosis is the key process in establishing versatile functions of cellular systems and enabling clean-water harvesting technologies. Membranes with single-atom thickness not only hold great promises in approaching the ultimate limit of these functions, but also offer an ideal test-bed to explore the underlying physical mechanisms. In this work, we explore diffusive and osmotic transport of water and ions through carbon nanotube and porous graphene based membranes by performing molecular dynamics simulations. Our comparative study shows that the cylindrical confinement in carbon nanotubes offers much higher salt rejection at similar permeability in osmosis compared to porous graphene. Moreover, chemical functionalization of the pores modulates the membrane performance by its steric and electrostatic nature, especially at small-size pores due to the fact that the optimal transport is achieved by ordered water transport near pore edges. These findings lay the ground for the ultimate design of forward osmosis membranes with optimized performance trade-off, given the capability of nano-engineering nanostructures by their geometry and chemistry. PMID:26037602

  18. Ultimate strength performance of tankers associated with industry corrosion addition practices

    NASA Astrophysics Data System (ADS)

    Kim, Do Kyun; Kim, Han Byul; Zhang, Xiaoming; Li, Chen Guang; Paik, Jeom Kee

    2014-09-01

    In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSRH) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures

  19. Weapons and commercial plutonium ultimate disposition choices: Destroy ``completely`` or store forever

    SciTech Connect

    Bowman, C.D.

    1994-07-01

    All of the options under consideration for weapons and commercial plutonium disposition ultimately boil down to the choices of either ``complete`` destruction or storage ``forever.`` None of the reactor-based plutonium burning systems demonstrated over the past 50 years of reactor development consume this material completely. Ultimately considerable unburned plutonium must be stored ``forever`` from those systems. Plutonium is considered to be dangerous both as a weapons material and as a health hazard. While properly stored plutonium might never make its way back by natural phenomena into the environment as a health hazard, stored plutonium is always accessible to recovery for malevolent purposes. It must be guarded wherever in the world it is stored for as long as it continues to exist. Complete destruction of the plutonium eliminates this material as a concern of future generations. Los Alamos National Laboratory accelerator-driven technology promises to allow safe and complete destruction of this material. Furthermore it appears that in the process of destruction the neutron rich features of the weapons plutonium provides benefits to society that place a value on weapons plutonium exceeding that of highly enriched uranium. A realistic time scale for development and deployment of burial technology either with or without partial burning in reactors is expected to be comparable with or to exceed the time for development and deployment of the accelerator-driven destruction method under study at Los Alamos.

  20. Plasticity and constraints on social evolution in African mole-rats: ultimate and proximate factors

    PubMed Central

    Faulkes, Chris G.; Bennett, Nigel C.

    2013-01-01

    Here, we review comparative studies of African mole-rats (family Bathyergidae) to explain how constraints acting at the ultimate (environmental) and proximate (organismal) levels have led to convergent gains and losses of sociality within this extensive adaptive radiation of subterranean rodents endemic to sub-Saharan Africa. At the ultimate level, living in environments that range from mesic through to arid has led to both variation and flexibility in social organization among species, culminating in the pinnacle of social evolution in the eusocial naked and Damaraland mole-rats (Heterocephalus glaber and Fukomys damarensis). The common mole-rat (Cryptomys hottentotus) provides a model example of how plasticity in social traits exists within a single species inhabiting areas with different ecological constraint. At the proximate level, reproductive strategies and cooperative breeding may be constrained by the correlated evolution of a suite of traits including physiological suppression of reproduction, the development of physiological and morphological castes, and the mode of ovulatory control and seasonality in breeding. Furthermore, recent neurobiological advances indicate that differential patterns of neurotransmitter expression within the forebrain may underpin (and limit) either a solitary or group living/cooperative lifestyle not only in mole-rats, but also more widely among disparate mammalian taxa. PMID:23569295

  1. Approaching Ultimate Intrinsic SNR in a Uniform Spherical Sample with Finite Arrays of Loop Coils

    PubMed Central

    Vaidya, Manushka V.; Sodickson, Daniel K.; Lattanzi, Riccardo

    2015-01-01

    We investigated to what degree and at what rate the ultimate intrinsic (UI) signal-to-noise ratio (SNR) may be approached using finite radiofrequency detector arrays. We used full-wave electromagnetic field simulations based on dyadic Green’s functions to compare the SNR of arrays of loops surrounding a uniform sphere with the ultimate intrinsic SNR (UISNR), for increasing numbers of elements over a range of magnetic field strengths, voxel positions, sphere sizes, and acceleration factors. We evaluated the effect of coil conductor losses and the performance of a variety of distinct geometrical arrangements such as “helmet” and “open-pole” configurations in multiple imaging planes. Our results indicate that UISNR at the center is rapidly approached with encircling arrays and performance is substantially lower near the surface, where a quadrature detection configuration tailored to voxel position is optimal. Coil noise is negligible at high field, where sample noise dominates. Central SNR for practical array configurations such as the helmet is similar to that of close-packed arrangements. The observed trends can provide physical insights to improve coil design. PMID:26097442

  2. Experimental and Numerical Studies on Ultimate Load Behaviour of Brick Masonry

    NASA Astrophysics Data System (ADS)

    Srinivas, Voggu; Sasmal, Saptarshi

    2016-06-01

    The present work brings out the studies on ultimate load behavior of brick masonry subjected to compression and shear-loading. The work composed of both the experimental and numerical investigations, aimed at contributing to the better understanding of the knowledge on the behavior of brick masonry structures under monotonic loading. Two brick masonry specimens have been tested up to ultimate load and the structural response in terms of the load, deflections and strains has been investigated. Due to the complexity, time and expense involved in the experimental investigations on brick masonry, limited number of experimental studies have been conducted and further, numerical studies have been carried out to simulate the experimental tests by suitably adopting the appropriate constitute models for the materials used. The responses and the failure load behaviour obtained from nonlinear numerical models developed are found to be in good agreement with the experimentally obtained results. The proposed numerical models can easily be adopted for further studies on the structural component made using brick masonry considering various geometric configurations, material disposition, loading conditions etc.

  3. Uncovering the ultimate performance of single-walled carbon nanotube films as transparent conductors

    NASA Astrophysics Data System (ADS)

    Mustonen, K.; Laiho, P.; Kaskela, A.; Susi, T.; Nasibulin, A. G.; Kauppinen, E. I.

    2015-10-01

    The ultimate performance—ratio of electrical conductivity to optical absorbance—of single-walled carbon nanotube (SWCNT) transparent conductive films (TCFs) is an issue of considerable application relevance. Here, we present direct experimental evidence that SWCNT bundling is detrimental for their performance. We combine floating catalyst synthesis of non-bundled, high-quality SWCNTs with an aggregation chamber, in which bundles with mean diameters ranging from 1.38 to 2.90 nm are formed from identical 3 μm long SWCNTs. The as-deposited TCFs from 1.38 nm bundles showed sheet resistances of 310 Ω/□ at 90% transparency, while those from larger bundles of 1.80 and 2.90 nm only reached values of 475 and 670 Ω/□, respectively. Based on these observations, we elucidate how networks formed by smaller bundles perform better due to their greater interconnectivity at a given optical density. Finally, we present a semi-empirical model for TCF performance as a function of SWCNT mean length and bundle diameter. This gives an estimate for the ultimate performance of non-doped, random network mixed-metallicity SWCNT TCFs at ˜80 Ω/□ and 90% transparency.

  4. The n-of-1 clinical trial: the ultimate strategy for individualizing medicine?

    PubMed Central

    Lillie, Elizabeth O; Patay, Bradley; Diamant, Joel; Issell, Brian; Topol, Eric J; Schork, Nicholas J

    2011-01-01

    N-of-1 or single subject clinical trials consider an individual patient as the sole unit of observation in a study investigating the efficacy or side-effect profiles of different interventions. The ultimate goal of an n-of-1 trial is to determine the optimal or best intervention for an individual patient using objective data-driven criteria. Such trials can leverage study design and statistical techniques associated with standard population-based clinical trials, including randomization, washout and crossover periods, as well as placebo controls. Despite their obvious appeal and wide use in educational settings, n-of-1 trials have been used sparingly in medical and general clinical settings. We briefly review the history, motivation and design of n-of-1 trials and emphasize the great utility of modern wireless medical monitoring devices in their execution. We ultimately argue that n-of-1 trials demand serious attention among the health research and clinical care communities given the contemporary focus on individualized medicine. PMID:21695041

  5. Development of base isolation device complied with the ultimate strength design code in Japan

    NASA Astrophysics Data System (ADS)

    Nishimura, Isao; Suzuki, Satoshi

    2016-04-01

    This paper reports the scheme of a research project funded by the Ministry of Land Infrastructure Transport and Tourism (MLIT) from the fiscal year of 2012 to 2014 under the title of "Development of base isolation device complied with the ultimate strength design code." The theoretical prediction tells us a new approach to develop a highly stable laminated rubber bearing that has a constant buckling load even under large lateral displacement. Relatively high shear stiffness makes it more stable and the height of the bearing should be longer than its diameter. They are the newly discovered theoretical buckling stability criteria from the previous studies conducted by the author's research team. The experimental studies in this project show the compatibility with the theoretical prediction and highly linear loaddisplacement relationship under large deformation. The performance of the newly developed device satisfies the requirement of the ultimate strength design code, if the ground condition of the target building is normally solid enough to prevent liquefaction. The theoretically predicted buckling stability of the laminated rubber bearings has been experimentally verified by the specimens of this project.

  6. Ultimate Heat Sink Thermal Performance and Water Utilization: Measurements on Cooling and Spray Ponds

    SciTech Connect

    Athey, G. F.; Hadlock, R. K.; Abbey, O. B.

    1982-02-01

    A data acquisition research program, entitled "Ultimate Heat Sink Performance Field Experiments," has been brought to completion. The primary objective is to obtain the requisite data to characterize thermal performance and water utilization for cooling ponds and spray ponds at elevated temperature. Such data are useful for modeling purposes, but the work reported here does not contain modeling efforts within its scope. The water bodies which have been studied are indicative of nuclear reactor ultimate heat sinks, components of emergency core cooling systems. The data reflect thermal performance and water utilization for meteorological and solar influences which are representative of worst-case combinations of conditions. Constructed water retention ponds, provided with absolute seals against seepage, have been chosen as facilities for the measurement programs; the first pond was located at Raft River, Idaho, and the second at East Mesa, California. The data illustrate and describe, for both cooling ponds and spray ponds, thermal performance and water utilization as the ponds cool from an initially elevated temperature. To obtain the initial elevated temperature, it has been convenient to conduct the measurements at geothermal sites having large supplies and delivery rates of hot geothermal fluid. The data are described and discussed in the text, and presented in the form of data volumes as appendices.

  7. The theoretical ultimate magnetoelectric coefficients of magnetoelectric composites by optimization design

    SciTech Connect

    Wang, H.-L.; Liu, B.

    2014-03-21

    This paper investigates what is the largest magnetoelectric (ME) coefficient of ME composites, and how to realize it. From the standpoint of energy conservation, a theoretical analysis is carried out on an imaginary lever structure consisting of a magnetostrictive phase, a piezoelectric phase, and a rigid lever. This structure is a generalization of various composite layouts for optimization on ME effect. The predicted theoretical ultimate ME coefficient plays a similar role as the efficiency of ideal heat engine in thermodynamics, and is used to evaluate the existing typical ME layouts, such as the parallel sandwiched layout and the serial layout. These two typical layouts exhibit ME coefficient much lower than the theoretical largest values, because in the general analysis the stress amplification ratio and the volume ratio can be optimized independently and freely, but in typical layouts they are dependent or fixed. To overcome this shortcoming and achieve the theoretical largest ME coefficient, a new design is presented. In addition, it is found that the most commonly used electric field ME coefficient can be designed to be infinitely large. We doubt the validity of this coefficient as a reasonable ME effect index and consider three more ME coefficients, namely the electric charge ME coefficient, the voltage ME coefficient, and the static electric energy ME coefficient. We note that the theoretical ultimate value of the static electric energy ME coefficient is finite and might be a more proper measure of ME effect.

  8. ULtiMATE System for Rapid Assembly of Customized TAL Effectors

    PubMed Central

    Wen, Dingqiao; Sheng, Ying; Zhu, Shiyou; Yu, Yuezhou; Gao, Xiang; Wei, Wensheng

    2013-01-01

    Engineered TAL-effector nucleases (TALENs) and TALE-based constructs have become powerful tools for eukaryotic genome editing. Although many methods have been reported, it remains a challenge for the assembly of designer-based TALE repeats in a fast, precise and cost-effective manner. We present an ULtiMATE (USER-based Ligation Mediated Assembly of TAL Effector) system for speedy and accurate assembly of customized TALE constructs. This method takes advantage of uracil-specific excision reagent (USER) to create multiple distinct sticky ends between any neighboring DNA fragments for specific ligation. With pre-assembled templates, multiple TALE DNA-binding domains could be efficiently assembled in order within hours with minimal manual operation. This system has been demonstrated to produce both functional TALENs for effective gene knockout and TALE-mediated gene-specific transcription activation (TALE-TA). The feature of both ease-of-operation and high efficiency of ULtiMATE system makes it not only an ideal method for biologic labs, but also an approach well suited for large-scale assembly of TALENs and any other TALE-based constructions. PMID:24228087

  9. Health care quality, access, cost, workforce, and surgical education: the ultimate perfect storm.

    PubMed

    Schwartz, Marshall Z

    2012-01-01

    The discussions on health care reform over the past two years have focused on cost containment while trying to maintain quality of care. Focusing on just cost and quality unfortunately does not address other very important factors that impact on our health care delivery system. Availability of a well-trained workforce, maintaining the sophisticated medical/surgical education system, and ultimately access to quality care by the public are critical to maintaining and enhancing our health care delivery system. Unfortunately, all five of these components are under at risk. Thus, we have evolving the ultimate perfect storm affecting our health care delivery system. Although not ideal and given the uniqueness of our population and their expectations, our current delivery system is excellent compared to other countries. However, the cost of our current system is rising at an alarming rate. Currently, health care consumes 17% of our gross domestic product. If our system is not revised this will continue to rise and by 2025 it will consume 48%. The dilemma, given the current state of our overall economy and rising debt, is how to address this major problem. Unfortunately, the Affordable Care Act, which is now law, does not address most of the issues and the cost was initially grossly under estimated. Furthermore, the law does not address the issues of workforce, maintaining our medical education system or ultimately, access. A major revision of our system will be necessary to truly create a system that protects and enhances all five of the components of our health care delivery system. To effectively accomplish this will require addressing those issues that lead to wasteful spending and diversion of our health care dollars to profit instead of care. Improved and efficient delivery systems that reduce complications, reduction of duplication of tertiary and quaternary programs or services within the same markets (i.e. regionalization of care), health insurance reform, and

  10. Xenobiology: A new form of life as the ultimate biosafety tool

    PubMed Central

    Schmidt, Markus

    2010-01-01

    Synthetic biologists try to engineer useful biological systems that do not exist in nature. One of their goals is to design an orthogonal chromosome different from DNA and RNA, termed XNA for xeno nucleic acids. XNA exhibits a variety of structural chemical changes relative to its natural counterparts. These changes make this novel information-storing biopolymer “invisible” to natural biological systems. The lack of cognition to the natural world, however, is seen as an opportunity to implement a genetic firewall that impedes exchange of genetic information with the natural world, which means it could be the ultimate biosafety tool. Here I discuss, why it is necessary to go ahead designing xenobiological systems like XNA and its XNA binding proteins; what the biosafety specifications should look like for this genetic enclave; which steps should be carried out to boot up the first XNA life form; and what it means for the society at large. PMID:20217844

  11. Xenobiology: a new form of life as the ultimate biosafety tool.

    PubMed

    Schmidt, Markus

    2010-04-01

    Synthetic biologists try to engineer useful biological systems that do not exist in nature. One of their goals is to design an orthogonal chromosome different from DNA and RNA, termed XNA for xeno nucleic acids. XNA exhibits a variety of structural chemical changes relative to its natural counterparts. These changes make this novel information-storing biopolymer "invisible" to natural biological systems. The lack of cognition to the natural world, however, is seen as an opportunity to implement a genetic firewall that impedes exchange of genetic information with the natural world, which means it could be the ultimate biosafety tool. Here I discuss, why it is necessary to go ahead designing xenobiological systems like XNA and its XNA binding proteins; what the biosafety specifications should look like for this genetic enclave; which steps should be carried out to boot up the first XNA life form; and what it means for the society at large. PMID:20217844

  12. 1-nm-thick graphene tri-layer as the ultimate copper diffusion barrier

    SciTech Connect

    Nguyen, Ba-Son; Lin, Jen-Fin

    2014-02-24

    We demonstrate the thinnest ever reported Cu diffusion barrier, a 1-nm-thick graphene tri-layer. X-ray diffraction patterns and Raman spectra show that the graphene is thermally stable at up to 750 °C against Cu diffusion. Transmission electron microscopy images show that there was no inter-diffusion in the Cu/graphene/Si structure. Raman analyses indicate that the graphene may have degraded into a nanocrystalline structure at 750 °C. At 800 °C, the perfect carbon structure was damaged, and thus the barrier failed. The results of this study suggest that graphene could be the ultimate Cu interconnect diffusion barrier.

  13. Fuzzy stochastic analysis of serviceability and ultimate limit states of two-span pedestrian steel bridge

    NASA Astrophysics Data System (ADS)

    Kala, Zdeněk; Sandovič, GiedrÄ--

    2012-09-01

    The paper deals with non-linear analysis of ultimate and serviceability limit states of two-span pedestrian steel bridge. The effects of random material and geometrical characteristics on limit states are analyzed. The Monte Carlo method was applied to stochastic analysis. For the serviceability limit state, also influence of fuzzy uncertainty of the limit deflection value on random characteristics of load capacity of variable action was studied. The results prove that, for the type of structure studied, the serviceability limit state is decisive from the point of view of design. The present paper opens a discussion on the use of stochastic analysis to verify the limit deflections given in the standards EUROCODES.

  14. Biomimetics and the Development of Humanlike Robots as the Ultimate Challenge

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2011-01-01

    Evolution led to effective solutions to nature's challenges and they were improved over millions of years. Humans have always made efforts to use nature as a model for innovation and problems solving. These efforts became more intensive in recent years where systematic studies of nature are being made towards better understanding and applying more sophisticated capabilities. Making humanlike robots, including the appearance, functions and intelligence, poses the ultimate challenges to biomimetics. For many years, making such robots was considered science fiction, but as a result of significant advances in biologically inspired technologies, such robots are increasingly becoming an engineering reality. There are already humanlike robots that walk, talk, interpret speech, make eye-contact and facial expressions, as well as perform many other humanlike functions. In this paper, the state-of-the-art of humanlike robots, potential applications and issues of concern will be reviewed.

  15. Plug nozzles - The ultimate customer driven propulsion system. [applied to manned lunar and Martian landers

    NASA Technical Reports Server (NTRS)

    Aukerman, Carl A.

    1991-01-01

    This paper presents the results of a study applying the plug cluster nozzle concept to the propulsion system for a typical lunar excursion vehicle. Primary attention for the design criteria is given to user defined factors such as reliability, low volume, and ease of propulsion system development. Total thrust and specific impulse are held constant in the study while other parameters are explored to minimize the design chamber pressure. A brief history of the plug nozzle concept is included to point out the advanced level of technology of the concept and the feasibility of exploiting the variables considered in the study. The plug cluster concept looks very promising as a candidate for consideration for the ultimate customer driven propulsion system.

  16. An experimental investigation on the ultimate strength of epoxy repaired braced partial infilled RC frames

    NASA Astrophysics Data System (ADS)

    Dubey, Shailendra Kumar Damodar; Kute, Sunil

    2014-09-01

    Due to earthquake, buildings are damaged partially or completely. Particularly structures with soft storey are mostly affected. In general, such damaged structures are repaired and reused. In this regard, an experimental investigation was planned and conducted on models of single-bay, single-storey of partial concrete infilled reinforced concrete (RC) frames up to collapse with corner, central and diagonal steel bracings. Such collapsed frames were repaired with epoxy resin and retested. The initiative was to identify the behaviour, extent of restored ultimate strength and deflection of epoxy-retrofitted frames in comparison to the braced RC frames. The performance of such frames has been considered only for lateral loads. In comparison to bare RC frames, epoxy repaired partial infilled frames have significant increase in the lateral load capacity. Central bracing is more effective than corner and diagonal bracing. For the same load, epoxy repaired frames have comparable deflection than similar braced frames.

  17. Methods for ultimate load analysis of concrete containments: Second phase: Interim report

    SciTech Connect

    Dameron, R.A.; Dunham, R.S.; Rashid, Y.R.

    1987-03-01

    This summary report gives an overview of research on the influence of special effects on the ultimate load behavior of concrete containment structures. The special effects analyses that were performed include containment response under combined pressure and temperature, shear dislocation at a major concrete crack, wall discontinuity at the wall-basemat juncture, flawed liner, and thermal buckling. The EPRI-sponsored finite element code, ABAQUS-EPGEN, is utilized as the structural analysis tool in this research. The code was modified to incorporate a constitutive model for plain concrete and models for concrete/liner and concrete/rebar interaction. The report provides a general assessment of local effects mechanisms in concrete containment response to overpressurization.

  18. An ultimate storage ring lattice with vertical emittance generated by damping wigglers

    SciTech Connect

    Huang, Xiaobiao

    2015-01-06

    We discuss the approach of generating round beams for ultimate storage rings using vertical damping wigglers (with horizontal magnetic field). The vertical damping wigglers provide damping and excite vertical emittance. This eliminates the need to generate large linear coupling that is impractical with traditional off-axis injection. We use a PEP-X compatible lattice to demonstrate the approach. This lattice uses separate quadrupole and sextupole magnets with realistic gradient strengths. Intrabeam scattering effects are calculated. As a result, the horizontal and vertical emittances are 22.3 pm and 10.3 pm, respectively, for a 200 mA, 4.5 GeV beam, with a vertical damping wiggler of a total length of 90 m, a peak field of 1.5 T and a wiggler period of 100 mm.

  19. Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length

    SciTech Connect

    Stewart, G.; Lackner, M.; Haid, L.; Matha, D.; Jonkman, J.; Robertson, A.

    2013-07-01

    With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation length on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.

  20. Determination of ultimate carbonaceous BOD and the specific rate constant (K1)

    USGS Publications Warehouse

    Stamer, J.K.; Bennett, J.P.; McKenzie, Stuart W.

    1982-01-01

    Ultimate carbonaceous biochemical oxygen demand (BODu) and the specific rate constant (K1) at which the demand is exerted are important parameters in designing biological wastewater treatment plants and in assessing the impact of wastewater on receiving streams. An analytical method is presented which uses time-series concentrations of BOD, defined as the calculated sum of dissolved oxygen (DO) losses at each time of measurement, for determining BODu and K1. Time-series DO measurements are obtained from a water sample that is incubated in darkness at 20 degrees Celsius in the presence of nitrapyrin, a chemical nitrification inhibitor. Time-series concentrations of BOD that approximate first order kinetics can be analyzed graphically or mathematically to compute BODu and K1.

  1. Proximate and Ultimate Analyses of Bagasse, Sorghum and Millet Straws as Precursors for Active Carbons

    NASA Astrophysics Data System (ADS)

    Lori, J. A.; Lawal, A. O.; Ekanem, E. J.

    This study reports the proximate and ultimate characteristics of bagasse, sorghum and millet straws in relation to their suitability for producing highly porous carbon. The results of ad hoc samples indicated, that particle size has a decisive influence on the proximate characteristics of bagasse, sorghum and millet straws. The effects of particle size on weight loss characteristics; rates of dehydration and de-volatilization of the carbon precursors were used to assess particle sizes that may be appropriate for carbonization. Particle sizes of 425-1180 µm are thus, suggested to be the most desirable, for the production of good quality porous carbon. This range of particles of bagasse, sorghum and millet straws were associated with diminishing ash contents. However, the optimum particle size of the cellulosic materials that is expected to yield highly porous carbon with minimum ash contents is 1180 µm.

  2. Cancer of unknown primary ultimately diagnosed as male breast cancer: A rare case report

    PubMed Central

    Rigakos, Georgios; Vakos, Amanda; Papadopoulos, Sotirios; Vernadou, Anastasia; Tsimpidakis, Antonios; Papachristou, Dionysios; Razis, Evangelia

    2016-01-01

    Cancers of unknown primary (CUP) constitute a significant diagnostic and therapeutic challenge for clinicians and a frequent cause of cancer-related mortality in Western countries. Immunohistochemistry assays are commonly used to identify the primary cancer, but fail in approximately one-third of cases. The identification of the possible origin of CUP is crucial, as it may help select the appropriate treatment options. We herein present the case of a 54-year-old male patient, who presented with lower back pain in June, 2013. Following a thorough investigation, the clinical and pathological findings could not identify the primary cancer, leading towards a misdiagnosis. Ultimately, microRNA testing of the resected spine lesion was able to identify the primary tumor as male breast cancer and allow for optimal treatment of the patient. PMID:27446561

  3. Stapledon's Interplanetary Man: A Commonwealth of Worlds and the Ultimate Purpose of Space Colonisation

    NASA Astrophysics Data System (ADS)

    Crawford, Ian A.

    In his 1948 lecture to the British Interplanetary Society Stapledon considered the ultimate purpose of colonising other worlds. Having examined the possible motivations arising from improved scientific knowledge and access to extraterrestrial raw materials, he concludes that the ultimate benefits of space colonisation will be the increased opportunities for developing human (and post-human) diversity, intellectual and aesthetic potential and, especially, `spirituality'. By the latter concept he meant a striving for ``sensitive and intelligent awareness of things in the universe (including persons), and of the universe as a whole.'' A key insight articulated by Stapledon in this lecture was that this should be the aspiration of all human development anyway, with or without space colonisation, but that the latter would greatly increase the scope for such developments. Another key aspect of his vision was the development of a diverse, but connected, `Commonwealth of Worlds' extending throughout the Solar System, and eventually beyond, within which human potential would be maximised. In this paper I analyse Stapledon's vision of space colonisation, and will conclude that his overall conclusions remain sound. However, I will also argue that he was overly utopian in believing that human social and political unity are prerequisites for space exploration (while agreeing that they are desirable objectives in their own right), and that he unnecessarily downplayed the more prosaic scientific and economic motivations which are likely to be key drivers for space exploration (if not colonisation) in the shorter term. Finally, I draw attention to some recent developments in international space policy which, although probably not influenced by Stapledon's work, are nevertheless congruent with his overarching philosophy as outlined in `Interplanetary Man?'.

  4. Functional photoacoustic microscopy of pH

    NASA Astrophysics Data System (ADS)

    Chatni, M. Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2012-02-01

    pH is a tightly regulated indicator of metabolic activity. In mammalian systems, imbalance of pH regulation may result from or result in serious illness. Even though the regulation system of pH is very robust, tissue pH can be altered in many diseases such as cancer, osteoporosis and diabetes mellitus. Traditional high-resolution optical imaging techniques, such as confocal microscopy, routinely image pH in cells and tissues using pH sensitive fluorescent dyes, which change their fluorescence properties with the surrounding pH. Since strong optical scattering in biological tissue blurs images at greater depths, high-resolution pH imaging is limited to penetration depths of 1mm. Here, we report photoacoustic microscopy (PAM) of commercially available pH-sensitive fluorescent dye in tissue phantoms. Using both opticalresolution photoacoustic microscopy (OR-PAM), and acoustic resolution photoacoustic microscopy (AR-PAM), we explored the possibility of recovering the pH values in tissue phantoms. In this paper, we demonstrate that PAM was capable of recovering pH values up to a depth of 2 mm, greater than possible with other forms of optical microscopy.

  5. The initial freezing point temperature of beef rises with the rise in pH: a short communication.

    PubMed

    Farouk, M M; Kemp, R M; Cartwright, S; North, M

    2013-05-01

    This study tested the hypothesis that the initial freezing point temperature of meat is affected by pH. Sixty four bovine M. longissimus thoracis et lumborum were classified into two ultimate pH groups: low (<5.8) and high pH (>6.2) and their cooling and freezing point temperatures were determined. The initial freezing temperatures for beef ranged from -0.9 to -1.5°C (∆=0.6°C) with the higher and lower temperatures associated with high and low ultimate pH respectively. There was a significant correlation (r=+0.73, P<0.01) between beef pH and freezing point temperature in the present study. The outcome of this study has implications for the meat industry where evidence of freezing (ice formation) in a shipment as a result of high pH meat could result in a container load of valuable chilled product being downgraded to a lower value frozen product.

  6. pH Meter probe assembly

    DOEpatents

    Hale, C.J.

    1983-11-15

    An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe. 1 fig.

  7. pH Meter probe assembly

    DOEpatents

    Hale, Charles J.

    1983-01-01

    An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe.

  8. How to Relate Complex DNA Repair Genotypes to Pathway Function and, Ultimately, Health Risk

    SciTech Connect

    Jones, IM

    2002-01-09

    Exposure to ionizing radiation increases the incidence of cancer. However, predicting which individuals are at most risk from radiation exposure is a distant goal. Predictive ability is needed to guide policies that regulate radiation exposure and ensure that medical treatments have maximum benefit and minimum risk. Differences between people in susceptibility to radiation are largely based on their genotype, the genes inherited from their parents. Among the important genes are those that produce proteins that repair DNA damaged by radiation. Base Excision Repair (BER) proteins repair single strand breaks and oxidized bases in DNA. Double Strand Break Repair proteins repair broken chromosomes. Using technologies and information from the Human Genome Project, we have previously determined that the DNA sequence of DNA repair genes varies within the human population. An average of 3-4 different variants were found that affect the protein for each of 37 genes studied. The average frequency of these variants is 5%. Given the many genes in each DNA repair pathway and their many variants, technical ability to determine an individual's repair genotype greatly exceeds ability to interpret the information. A long-term goal is to relate DNA repair genotypes to health risk from radiation. This study focused on the BER pathway. The BER genes are known, variants of the genes have been identified at LLNL, and LLNL had recently developed an assay for BER function using white blood cells. The goal of this initial effort was to begin developing data that could be used to test the hypothesis that many different genotypes have similar DNA repair capacity phenotypes (function). Relationships between genotype and phenotype could then be used to group genotypes with similar function and ultimately test the association of groups of genotypes with health risk from radiation. Genotypes with reduced repair function are expected to increase risk of radiation-induced health effects. The goal

  9. Lattice Design for PEP-X Ultimate Storage Ring Light Source

    SciTech Connect

    Bane, K.L.F.; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; Hettel, R.O.; /SLAC

    2011-12-13

    SLAC expertise in designing and operating high current storage rings and the availability of the 2.2-km PEP-II tunnel present an opportunity for building a next generation light source - PEP-X - that would replace the SPEAR3 storage ring in the future. The PEP-X 'baseline' design, with 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. As a next step, a so-called 'ultimate' PEP-X lattice, reducing the emittance to 11 pm-rad at zero current, has been designed. This emittance approaches the diffraction limited photon emittance for multi-keV photons, providing near maximum photon brightness and high coherence. It is achieved by using 7-bend achromat cells in the ring arcs and a 90-m damping wiggler in one of the 6 long straight sections. Details of the lattice design, dynamic aperture, and calculations of the intra-beam scattering effect and Touschek lifetime at a nominal 0.2 A current are presented. Accelerator-based light sources are in high demand for many experimental applications. The availability of the 2.2-km PEP-II tunnel at SLAC presents an opportunity for building a next generation light source - PEP-X - that would replace the existing SPEAR3 light source in the future. The PEP-X study started in 2008, and the 'baseline' design, yielding 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. This relatively conservative design can be built using existing technology. However, for a long term future, it is natural to investigate a more aggressive, so-called 'ultimate' ring design. The goal is to reduce the electron emittance in both x and y planes to near the diffraction limited photon emittance of 8 pm-rad at hard X-ray photon wavelength of 0.1 nm. This would provide a near maximum photon brightness and significant increase in photon coherence. This study was motivated by the advances in low emittance design at MAX-IV. The latter was used as a starting point for the PEP-X arc lattice

  10. Stiffness and ultimate load of osseointegrated prosthesis fixations in the upper and lower extremity

    PubMed Central

    2013-01-01

    Background Techniques for the skeletal attachment of amputation-prostheses have been developed over recent decades. This type of attachment has only been performed on a small number of patients. It poses various potential advantages compared to conventional treatment with a socket, but is also associated with an increased risk of bone or implant-bone interface fracture in the case of a fall. We therefore investigated the bending stiffness and ultimate bending moment of such devices implanted in human and synthetic bones. Methods Eight human specimens and 16 synthetic models of the proximal femora were implanted with lower extremity prostheses and eight human specimens and six synthetic humeri were implanted with upper extremity prostheses. They were dissected according to typical amputation levels and underwent loading in a material testing machine in a four-point bending setup. Bending stiffness, ultimate bending moment and fracture modes were determined in a load to failure experiment. Additionally, axial pull-out was performed on eight synthetic specimens of the lower extremity. Results Maximum bending moment of the synthetic femora was 160.6±27.5 Nm, the flexural rigidity of the synthetic femora was 189.0±22.6 Nm2. Maximum bending moment of the human femora was 100.4±38.5 Nm, and the flexural rigidity was 137.8±29.4 Nm2. The maximum bending moment of the six synthetic humeri was 104.9±19.0 Nm, and the flexural rigidity was 63.7±3.6 Nm2. For the human humeri the maximum bending moment was 36.7±11.0 Nm, and the flexural rigidity at was 43.7±10.5 Nm2. The maximum pull-out force for the eight synthetic femora was 3571±919 N. Conclusion Significant differences were found between human and synthetic specimens of the lower and upper extremity regarding maximum bending moment, bending displacement and flexural rigidity. The results of this study are relevant with respect to previous finding regarding the load at the interfaces of osseointegrated prosthesis

  11. Influence of Reel Lay on Residual Stress and Ultimate Bearing Capacity of Pipe

    NASA Astrophysics Data System (ADS)

    Liao, Hongqian; Wang, Liquan

    Reel lay is a fast and cost-effective way to install subsea pipelines. During reel lay, pipe's repeated plastic bending produces residual stress, which has influence on pipe's ultimate bearing capacity. First, the deformation of pipe in reel lay is analyzed, and the cyclic bending stages are simplified for convenience of theoretical research. Based on the finite element method (FEM), the Ramberg-Osgood model is adopted to describe material's mechanical property with kinematic hardening rule, and five bending stages are simulated. Further, the influence of material parameters and geometry parameters on pipe's residual stress is studied. Finally, the effect of residual stress on pipe's external pressure bearing capacity and tensile capacity is analyzed. Some important conclusions can be drawn: (1) the influence of diameter-thick ratio on residual stress is small, and material parameters' effect on the residual stress is large; (2) the influence of residual stress on pipe's external pressure bearing capacity is small, but its influence on tensile capacity is large.

  12. Near-infrared grating-assisted SPR optical fiber sensors: design rules for ultimate refractometric sensitivity.

    PubMed

    Caucheteur, Christophe; Voisin, Valérie; Albert, Jacques

    2015-02-01

    Plasmonic optical fiber sensors are continuously developed for (bio)chemical sensing purposes. Recently, surface plasmon resonance (SPR) generation was achieved in gold-coated tilted fiber Bragg gratings (TFBGs). These sensors probe the surrounding medium with near-infrared narrowband resonances, which enhances both the penetration depth of the evanescent field in the external medium and the wavelength resolution of the interrogation. They constitute a unique configuration to probe all the fiber cladding modes individually. We use them to analyze the modal distribution of gold-coated telecommunication-grade optical fibers immersed in aqueous solutions. Theoretical investigations with a finite-difference complex mode solver are confirmed by experimental data obtained on TFBGs. We show that the refractometric sensitivity varies with the mode order and that the global SPR envelope shift in response to surrounding refractive index (SRI) changes higher than 1e-2 RIU (refractive index unit) can be ~25% bigger than the local SPR mode shift arising from SRI changes limited to 1e-4 RIU. We bring clear evidence that the optimum gold thickness for SPR generation lies in the range between 50 and 70 nm while a cladding diameter decrease from 125 µm to 80 µm enhances the refractometric sensitivity by ~20%. Finally, we demonstrate that the ultimate refractometric sensitivity of cladding modes is ~550 nm/RIU when they are probed by gold-coated TFBGs. PMID:25836153

  13. Evidence for bay region activation of chrysene 1,2-dihydrodiol to an ultimate carcinogen.

    PubMed

    Levin, W; Wood, A W; Chang, R L; Yagi, H; Mah, H D; Jerina, D M; Conney, A H

    1978-06-01

    The tumor-initiating activities of chrysene and the three metabolically possible trans-dihydrodiols at the 1,2-, 3,4-, and 5,6-positions of chyrsene were determined on the skin of female CD-1 mice. A single topical application of 0.4, 1.25, or 4.0 mumol of each compound was followed 7 days later by twice-weekly applications of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate for 25 weeks. The most potent tumor initiator was chrysene 1,2-dihydrodiol, which had approximately twice the tumorigenic activity of the parent hydrocarbon chrysene at all doses tested. Chrysene 3,4-dihydrodiol and chrysene 5,6-dihydrodiol had no significant tumorigenic activity. 1,2-Dihydroxy-1,2,3,4-tetrahydrochrysene, a compound related to chrysene 1,2-dihydrodiol but with the conjugated nonaromatic double bond removed from the 3,4-position of the molecule, had less than 25% of the tumorigenic activity of chrysene 1,2-dihydrodiol. These results indicate that chrysene 1,2-dihydrodiol is a proximate carcinogenic metabolite of chrysene and that a chrysene 1,2-diol-3,4-epoxide, in which the epoxide group forms part of the bay region in the molecule, is a likely candidate as an ultimate carcinogenic metabolite of chrysene.

  14. The ultimate constant of head and neck oncology—the physician-patient relationship.

    PubMed

    Day, Terry A

    2014-12-01

    Head and neck surgeons have the unique opportunity to engage with humans in life and death situations. We are confronting cancer, cure, failure, self-image, and most of all, a bond with the patient and family. We would like to view our expertise in head and neck surgery and the world of caring for our patients much like a Brigadoon. However, we daily are confronted with ever-changing and evolving approaches to health care that do not involve the physician or the patient. What kind of world is healthcare without a physician-patient interaction? Yes, there is the government-supported electronic medical record, which is here to stay (until our electrical and/or wired network fails). Yes, there is new technology, including robotic surgery and telemedicine and efforts to link these to our cell phones and applications, making care and expertise more available across long distances. And yes, there exist goals to extend care beyond the physician to other health care professions as the buffer between the physician and the patient, sometimes to reduce cost and sometimes to make care more ubiquitous. However, an Internet search will show that most say that the only constant in healthcare is change. I propose that the ultimate constant in healthcare is the physician-patient relationship.

  15. Ultimate performance of new infrared HgCdTe focal plane arrays

    NASA Astrophysics Data System (ADS)

    Osipov, V. V.; Ponomarenko, Vladimir P.; Selyakov, A. Y.

    1999-06-01

    We theoretically study physical processes in new promising hybrid IR FPAs based on HgCdTe p-n junctions and analyze them ultimate performance for 3 - 5 micrometers and 8 - 10 micrometers spectral ranges. Architecture of these FPAs are much simpler than that of existing FPAs: IR-sensitive HgCdTe p-n junctions are used as switches themselves, and capacitors used as strong elements occupy all the area under each p-n junction. These capacitors can be produced on the base of dielectrics with relatively high permittivity (of TiO2, type or integrated ferroelectrics). In contrast to CCD and CID, the proposed FPA does not use charge transfer between electrodes separated in space. We formulate requirements to the parameters of photosensitive elements and storage capacitors to reach the largest integration time and threshold characteristics close to the theoretical limits. It is shown that in principle the considered FPAs have unique parameters and 1/f noise of amplifiers can be suppressed in them. FPA for 3 - 5 micrometers spectral range with p-n junction of 20 X 20 micrometers 2 area can operate in BLIP mode at background temperature 300 K;its photosignal integration time equal to the persistence of human eye and format can reach 1024 X 1024 pixels. For 8 - 10 micrometers range these parameters are 300 microsecond(s) and 256 X 256 pixels, respectively, when TiO2 storage capacitors are used.

  16. Ultimate thin vertical p–n junction composed of two-dimensional layered molybdenum disulfide

    PubMed Central

    Li, Hua-Min; Lee, Daeyeong; Qu, Deshun; Liu, Xiaochi; Ryu, Jungjin; Seabaugh, Alan; Yoo, Won Jong

    2015-01-01

    Semiconducting two-dimensional crystals are currently receiving significant attention because of their great potential to be an ultrathin body for efficient electrostatic modulation, which enables to overcome the limitations of silicon technology. Here we report that, as a key building block for two-dimensional semiconductor devices, vertical p–n junctions are fabricated in ultrathin MoS2 by introducing AuCl3 and benzyl viologen dopants. Unlike usual unipolar MoS2, the MoS2 p–n junctions show ambipolar carrier transport, current rectification via modulation of potential barrier in films thicker than 8 nm and reversed current rectification via tunnelling in films thinner than 8 nm. The ultimate thinness of the vertical p–n homogeneous junctions in MoS2 is experimentally found to be 3 nm, and the chemical doping depth is found to be 1.5 nm. The ultrathin MoS2 p–n junctions present a significant potential of the two-dimensional crystals for flexible, transparent, high-efficiency electronic and optoelectronic applications. PMID:25800613

  17. Effect of Load Rate on Ultimate Tensile Strength of Ceramic Matrix Composites at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.

    2001-01-01

    The strengths of three continuous fiber-reinforced ceramic composites, including SiC/CAS-II, SiC/MAS-5 and SiC/SiC, were determined as a function of test rate in air at 1100 to 1200 C. All three composite materials exhibited a strong dependency of strength on test rate, similar to the behavior observed in many advanced monolithic ceramics at elevated temperatures. The application of the preloading technique as well as the prediction of life from one loading configuration (constant stress-rate) to another (constant stress loading) suggested that the overall macroscopic failure mechanism of the composites would be the one governed by a power-law type of damage evolution/accumulation, analogous to slow crack growth commonly observed in advanced monolithic ceramics. It was further found that constant stress-rate testing could be used as an alternative to life prediction test methodology even for composite materials, at least for short range of lifetimes and when ultimate strength is used as the failure criterion.

  18. The ultimate technology: the end of technology and the task of nature.

    PubMed

    Riis, Søren

    2013-01-01

    One of the most influential philosophers of the 20th century, Martin Heidegger (1889-1976), died prior to the remarkable cloning of the sheep Dolly and before Dr. Venter started his experiments on creating synthetic life, and he never explicitly discussed living technologies. However, by reinterpreting his notion of "modern technology," this article shows how it is possible to philosophically assess living technologies and to recognize ways in which Heidegger anticipated this phenomenon with his notion of cybernetics. The interpretation elucidates the fundamental process of technology becoming living and simultaneously presents living technology as the ultimate technology. The thesis of this article is that living technology is not just one more technology; rather, it is the perfection of technology as understood by Aristotle. Aristotle's thinking is in this way a key example of a profound reassessment of nature and technology. Aristotle clearly separates these two domains of being in his definition, but in doing so, he also connects them to one another in a highly influential way. Following this line of thought, the article finally offers an original perspective involving renewed respect for the perpetual self-unfolding nature of living technology.

  19. Ultimate thin vertical p-n junction composed of two-dimensional layered molybdenum disulfide.

    PubMed

    Li, Hua-Min; Lee, Daeyeong; Qu, Deshun; Liu, Xiaochi; Ryu, Jungjin; Seabaugh, Alan; Yoo, Won Jong

    2015-01-01

    Semiconducting two-dimensional crystals are currently receiving significant attention because of their great potential to be an ultrathin body for efficient electrostatic modulation, which enables to overcome the limitations of silicon technology. Here we report that, as a key building block for two-dimensional semiconductor devices, vertical p-n junctions are fabricated in ultrathin MoS₂ by introducing AuCl₃ and benzyl viologen dopants. Unlike usual unipolar MoS₂, the MoS₂ p-n junctions show ambipolar carrier transport, current rectification via modulation of potential barrier in films thicker than 8 nm and reversed current rectification via tunnelling in films thinner than 8 nm. The ultimate thinness of the vertical p-n homogeneous junctions in MoS₂ is experimentally found to be 3 nm, and the chemical doping depth is found to be 1.5 nm. The ultrathin MoS₂ p-n junctions present a significant potential of the two-dimensional crystals for flexible, transparent, high-efficiency electronic and optoelectronic applications.

  20. COLLECTIVE VORTEX BEHAVIORS: DIVERSITY, PROXIMATE, AND ULTIMATE CAUSES OF CIRCULAR ANIMAL GROUP MOVEMENTS.

    PubMed

    Delcourt, Johann; Bode, Nikolai W F; Denoël, Mathieu

    2016-03-01

    Ant mill, caterpillar circle, bat doughnut, amphibian vortex, duck swirl, and fish torus are different names for rotating circular animal formations, where individuals turn around a common center. These "collective vortex behaviors" occur at different group sizes from pairs to several million individuals and have been reported in a large number of organisms, from bacteria to vertebrates, including humans. However, to date, no comprehensive review and synthesis of the literature on vortex behaviors has been conducted. Here, we review the state of the art of the proximate and ultimate causes of vortex behaviors. The ubiquity of this behavioral phenomenon could suggest common causes or fundamental underlying principles across contexts. However, we find that a variety of proximate mechanisms give rise to vortex behaviors. We highlight the potential benefits of collective vortex behaviors to individuals involved in them. For example, in some species, vortices increase feeding efficiency and could give protection against predators. It has also been argued that vortices could improve collective decision-making and information transfer. We highlight gaps in our understanding of these ubiquitous behavioral phenomena and discuss future directions for research in vortex studies. PMID:27192777

  1. The Ultimate Monte Carlo: Studying Cross-Sections With Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Wilson, Thomas L.

    2007-01-01

    The high-energy physics community has been discussing for years the need to bring together the three principal disciplines that study hadron cross-section physics - ground-based accelerators, cosmic-ray experiments in space, and air shower research. Only recently have NASA investigators begun discussing the use of space-borne cosmic-ray payloads to bridge the gap between accelerator physics and air shower work using cosmic-ray measurements. The common tool used in these three realms of high-energy hadron physics is the Monte Carlo (MC). Yet the obvious has not been considered - using a single MC for simulating the entire relativistic energy range (GeV to EeV). The task is daunting due to large uncertainties in accelerator, space, and atmospheric cascade measurements. These include inclusive versus exclusive cross-section measurements, primary composition, interaction dynamics, and possible new physics beyond the standard model. However, the discussion of a common tool or ultimate MC might be the very thing that could begin to unify these independent groups into a common purpose. The Offline ALICE concept of a Virtual MC at CERN s Large Hadron Collider (LHC) will be discussed as a rudimentary beginning of this idea, and as a possible forum for carrying it forward in the future as LHC data emerges.

  2. Ultimate capacity of linear time-invariant bosonic channels with additive Gaussian noise

    NASA Astrophysics Data System (ADS)

    Roy Bardhan, Bhaskar; Shapiro, Jeffrey H.

    2016-03-01

    Fiber-optic communications are moving to coherent detection in order to increase their spectral efficiency, i.e., their channel capacity per unit bandwidth. At power levels below the threshold for significant nonlinear effects, the channel model for such operation a linear time-invariant filter followed by additive Gaussian noise is one whose channel capacity is well known from Shannon's noisy channel coding theorem. The fiber channel, however, is really a bosonic channel, meaning that its ultimate classical information capacity must be determined from quantum-mechanical analysis, viz. from the Holevo-Schumacher-Westmoreland (HSW) theorem. Based on recent results establishing the HSW capacity of a linear (lossy or amplifying) channel with additive Gaussian noise, we provide a general continuous-time result, namely the HSW capacity of a linear time-invariant (LTI) bosonic channel with additive Gaussian noise arising from a thermal environment. In particular, we treat quasi-monochromatic communication under an average power constraint through a channel comprised of a stable LTI filter that may be attenuating at all frequencies or amplifying at some frequencies and attenuating at others. Phase-insensitive additive Gaussian noise-associated with the continuous-time Langevin noise operator needed to preserve free-field commutator brackets is included at the filter output. We compare the resulting spectral efficiencies with corresponding results for heterodyne and homodyne detection over the same channel to assess the increased spectral efficiency that might be realized with optimum quantum reception.

  3. Ultimate intra-wafer critical dimension uniformity control by using lithography and etch tool corrections

    NASA Astrophysics Data System (ADS)

    Kubis, Michael; Wise, Rich; Reijnen, Liesbeth; Viatkina, Katja; Jaenen, Patrick; Luca, Melisa; Mernier, Guillaume; Chahine, Charlotte; Hellin, David; Kam, Benjamin; Sobieski, Daniel; Vertommen, Johan; Mulkens, Jan; Dusa, Mircea; Dixit, Girish; Shamma, Nader; Leray, Philippe

    2016-03-01

    With shrinking design rules, the overall patterning requirements are getting aggressively tighter. For the 7-nm node and below, allowable CD uniformity variations are entering the Angstrom region (ref [1]). Optimizing inter- and intra-field CD uniformity of the final pattern requires a holistic tuning of all process steps. In previous work, CD control with either litho cluster or etch tool corrections has been discussed. Today, we present a holistic CD control approach, combining the correction capability of the etch tool with the correction capability of the exposure tool. The study is done on 10-nm logic node wafers, processed with a test vehicle stack patterning sequence. We include wafer-to-wafer and lot-to-lot variation and apply optical scatterometry to characterize the fingerprints. Making use of all available correction capabilities (lithography and etch), we investigated single application of exposure tool corrections and of etch tool corrections as well as combinations of both to reach the lowest CD uniformity. Results of the final pattern uniformity based on single and combined corrections are shown. We conclude on the application of this holistic lithography and etch optimization to 7nm High-Volume manufacturing, paving the way to ultimate within-wafer CD uniformity control.

  4. Toward ultimate miniaturization of high Q silicon traveling-wave microresonators.

    PubMed

    Soltani, Mohammad; Li, Qing; Yegnanarayanan, Siva; Adibi, Ali

    2010-09-13

    High Q traveling-wave resonators (TWR)s are one of the key building block components for VLSI Photonics and photonic integrated circuits (PIC). However, dense VLSI integration requires small footprint resonators. While photonic crystal resonators have shown the record in simultaneous high Q (~10(5)-10(6)) and very small mode volumes; the structural simplicity of TWRs has motivated many ongoing researches on miniaturization of these resonators with maintaining Q in the same range. In this paper, we investigate the scaling issues of silicon traveling-wave microresonators down to ultimate miniaturization levels in SOI platforms. Two main constraints that are considered during this down scaling are: 1) Preservation of the intrinsic Q of the resonator at high values, and 2) Compatibility of resonator with passive (active) integration by preserving the SiO(2) BOX layer (plus a thin Si slab layer for P-N junction fabrication). Microdisk and microdonut (an intermediate design between disk and ring shape) are considered for high Q, miniaturization, and single-mode operation over a wide wavelength range (as high as the free-spectral range). Theoretical and experimental results for miniaturized resonators are demonstrated and Q's as high as ~10(5) for resonators as small as 1.5 μm radius are achieved. PMID:20940850

  5. Bottlenose dolphins (Tursiops truncatus) prefer to cooperate when petted: Integrating proximate and ultimate explanations II.

    PubMed

    Perelberg, Amir; Schuster, Richard

    2009-02-01

    Cooperation poses theoretical problems because the behaviors of individuals can benefit others. Evolutionary and game-theory explanations that focus on maximizing one's own material outcomes are usually supported by experimental models with isolated and anonymous subjects. Cooperation in the natural world, however, is often a social act whereby familiar individuals coordinate behaviors for shared outcomes. Social cooperation is also associated with a cooperation bias expressed as a preference for cooperation even when noncooperation is immediately more beneficial. The authors report on evidence for such a bias in a captive group of bottlenose dolphins that voluntarily preferred to receive petting from human guides by using a pairwise coordinated approach, even though this was more difficult, and total petting amount was thereby reduced. To explain why this bias occurs, the authors propose an integrated behavioral-evolutionary approach whereby performance is determined by two kinds of immediate outcomes: material gains and intrinsic affective states associated with cooperating. The latter can provide reinforcement when immediate material gains are reduced, delayed, or absent. Over a lifetime, this proximate mechanism can lead to cooperative relationships whose long-term ultimate consequences can be adaptive.

  6. Salinization: the ultimate threat to temperate lakes, with particular reference to Southeastern Wisconsin (USA)

    NASA Astrophysics Data System (ADS)

    Thornton, Jeffrey A.; Slawski, Thomas M.; Lin, Hebin

    2015-11-01

    Many lakes in Southeastern Wisconsin (the metropolitan-Milwaukee area) are gradually becoming increasingly "salty". While these waterbodies would not be considered presently to be saline lakes, there has been a rapid increase in the chloride concentrations in most of these lakes over the last 30 years, with the lakes increasing from a mean chloride concentration of about 19 mg/L to over 100 mg/L in some cases. While ecological impacts can be expected when chloride values exceed 250 mg/L, the rate of increase presents a basis for concern, especially since the underlying geology of the region is based on limestone/dolomite which is deficient in chlorides. Thus, the origin of the chlorides is anthropogenic: human and industrial wastewaters (treatment of which has effected improvements in trophic status but has not affected other water-borne contaminants) and winter de-icing practices based upon large quantities of sodium chloride are major contributors to the increasing concentrations of chloride in the region's waterways. Without taking remedial measures, the rate of salinization is expected to continue to increase, resulting, ultimately, in the alteration of the freshwater systems in the region.

  7. The CRISPR-Cas9 technology: Closer to the ultimate toolkit for targeted genome editing.

    PubMed

    Quétier, Francis

    2016-01-01

    The first period of plant genome editing was based on Agrobacterium; chemical mutagenesis by EMS (ethyl methanesulfonate) and ionizing radiations; each of these technologies led to randomly distributed genome modifications. The second period is associated with the discoveries of homing and meganuclease enzymes during the 80s and 90s, which were then engineered to provide efficient tools for targeted editing. From 2006 to 2012, a few crop plants were successfully and precisely modified using zinc-finger nucleases. A third wave of improvement in genome editing, which led to a dramatic decrease in off-target events, was achieved in 2009-2011 with the TALEN technology. The latest revolution surfaced in 2013 with the CRISPR-Cas9 system, whose high efficiency and technical ease of use is really impressive; scientists can use in-house kits or commercially available kits; the only two requirements are to carefully choose the location of the DNA double strand breaks to be induced and then to order an oligonucleotide. While this close-to- ultimate toolkit for targeted editing of genomes represents dramatic scientific progress which allows the development of more complex useful agronomic traits through synthetic biology, the social acceptance of genome editing remains regularly questioned by anti-GMO citizens and organizations. PMID:26566825

  8. NDM-1, the ultimate promiscuous enzyme: substrate recognition and catalytic mechanism

    PubMed Central

    Kim, Youngchang; Cunningham, Mark A.; Mire, Joseph; Tesar, Christine; Sacchettini, James; Joachimiak, Andrzej

    2013-01-01

    The specter of a return to an era in which infectious disease looms as a significant threat to human health is not just hyperbole; there are serious concerns about the widespread overuse and misuse of antibiotics contributing to increased antibiotic resistance in pathogens. The recent discovery of a new enzyme, first identified in Klebsiella pneumoniae from a patient from New Delhi and denoted as NDM-1, represents an example of extreme promiscuity: It hydrolyzes and inactivates nearly all known β-lactam-based antibiotics with startling efficiency. NDM-1 can utilize different metal cofactors and seems to exploit an alternative mechanism based on the reaction conditions. Here we report the results of a combined experimental and theoretical study that examines the substrate, metal binding, and catalytic mechanism of the enzyme. We utilize structures obtained through X-ray crystallography, biochemical assays, and numerical simulation to construct a model of the enzyme catalytic pathway. The NDM-1 enzyme interacts with the substrate solely through zinc, or other metals, bound in the active site, explaining the observed lack of specificity against a broad range of β-lactam antibiotic agents. The zinc ions also serve to activate a water molecule that hydrolyzes the β-lactam ring through a proton shuttle.—Kim, Y., Cunningham, M. A.; Mire, J., Tesar, C., Sacchettini, J., Joachimiak, A. NDM-1, the ultimate promiscuous enzyme: substrate recognition and catalytic mechanism. PMID:23363572

  9. The ultimate question of origins: God and the beginning of the Universe.

    NASA Astrophysics Data System (ADS)

    Craig, W. L.

    Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the Universe. The ultimate question remains why the Universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz's critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the Universe began to exist, however, calls into question the Universe's status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the Universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the Universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz's conclusion. Several objections to inferring a supernatural cause of the origin of the Universe are considered and found to be unsound.

  10. The Ultimate Question of Origins: God and the Beginning of the Universe

    NASA Astrophysics Data System (ADS)

    Craig, William Lane

    1999-12-01

    Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the universe. The ultimate question remains why the universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz's critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the universe began to exist, however, calls into question the universe's status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz's conclusion. Several objections to inferring a supernatural cause of the origin of the universe are considered and found to be unsound.

  11. Correlation between the ultimate elongations of rapidly expanding rings and stretching metal jets

    SciTech Connect

    Gourdin, W.H.

    1990-08-01

    The recent work of Duffy and Golaski and Lichtenberger demonstrated that the initial metallurgical condition of a material can significantly affect its performance when used as a shaped-charge liner. Duffy and Golaski showed that the penetration of copper shaped charges increases by 10--20% when the grain size of the liner is reduced from 150 to 25 {mu}m and the uniformity of the microstructure is improved. Lichtenberger confirmed this behavior in liners made from oxygen-free electronic (OFE) grade copper and also showed that the purity of the liner material can produce similar effects. These observations suggest that some characteristic of the liner material itself can be correlated with shaped-charge performance. Such a characteristic, along with a corresponding laboratory test procedure, would be very useful as a means of identifying promising candidate materials prior to the expensive testing of prototype munitions. Lichtenberger has suggested that the recrystallization temperature'' is one such characteristic, and he has successfully demonstrated a correlation with jet behavior. In this paper, I suggest that the ultimate elongation of specimen rings expanded by means of the electromagnetic launch technique is another material characteristic that appears to correlate with the breakup behavior of stretching metal jets. I briefly discuss in general terms why such a correlation may exist and then offer some limited experimental evidence for it.

  12. The CRISPR-Cas9 technology: Closer to the ultimate toolkit for targeted genome editing.

    PubMed

    Quétier, Francis

    2016-01-01

    The first period of plant genome editing was based on Agrobacterium; chemical mutagenesis by EMS (ethyl methanesulfonate) and ionizing radiations; each of these technologies led to randomly distributed genome modifications. The second period is associated with the discoveries of homing and meganuclease enzymes during the 80s and 90s, which were then engineered to provide efficient tools for targeted editing. From 2006 to 2012, a few crop plants were successfully and precisely modified using zinc-finger nucleases. A third wave of improvement in genome editing, which led to a dramatic decrease in off-target events, was achieved in 2009-2011 with the TALEN technology. The latest revolution surfaced in 2013 with the CRISPR-Cas9 system, whose high efficiency and technical ease of use is really impressive; scientists can use in-house kits or commercially available kits; the only two requirements are to carefully choose the location of the DNA double strand breaks to be induced and then to order an oligonucleotide. While this close-to- ultimate toolkit for targeted editing of genomes represents dramatic scientific progress which allows the development of more complex useful agronomic traits through synthetic biology, the social acceptance of genome editing remains regularly questioned by anti-GMO citizens and organizations.

  13. Moisture absorption early postmortem predicts ultimate drip loss in fresh pork.

    PubMed

    Kapper, C; Walukonis, C J; Scheffler, T L; Scheffler, J M; Don, C; Morgan, M T; Forrest, J C; Gerrard, D E

    2014-02-01

    Water-holding capacity is the ability of meat to hold moisture and is subject to postmortem metabolism. The objective of this study was to characterize the loss of moisture from muscle postmortem and investigate whether these losses are useful in predicting the ultimate drip loss of fresh pork. Cotton-rayon absorptive-based devices were inserted in the longissimus dorsi muscles of pork carcasses (n = 51) postmortem and removed at various intervals for 24h. Greatest moisture absorption was observed at 105 min post exsanguination. Drip loss varied (0.6-15.3%) across carcasses. Individual absorption at 75 min correlated (r = 0.33) with final drip loss. Correlations improved using individual absorption values at 90 min (r = 0.48) and accumulated absorption values at 150 min (r = 0.41). Results show that significant moisture is lost from muscle tissue early postmortem and suggest that capture of this moisture may be useful in predicting final drip loss of fresh meat.

  14. Dynamic Aperture and Tolerances for PEP-X Ultimate Storage Ring Design

    SciTech Connect

    Borland, M.; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; Hettel, R.O.; /SLAC

    2011-12-13

    A lattice for the PEP-X ultimate storage ring light source, having 11 pm-rad natural emittance at a beam energy of 4.5 GeV at zero current, using 90 m of damping wiggler and fitting into the existing 2.2-km PEP-II tunnel, has been recently designed. Such a low emittance lattice requires very strong sextupoles for chromaticity correction, which in turn introduce strong non-linear field effects that limit the beam dynamic aperture. In order to maximize the dynamic aperture we choose the cell phases to cancel the third and fourth order geometric resonances in each 8-cell arc. Four families of chromatic sextupoles and six families of geometric (or harmonic) sextupoles are added to correct the chromatic and amplitude-dependent tunes. To find the best settings of the ten sextupole families, we use a Multi-Objective Genetic Optimizer employing elegant to optimize the beam lifetime and dynamic aperture simultaneously. Then we evaluate dynamic aperture reduction caused by magnetic field multipole errors, magnet fabrication errors and misalignments. A sufficient dynamic aperture is obtained for injection, as well as workable beam lifetime.

  15. A novel pathway to the ultimate mutagens of aromatic amino and nitro compounds.

    PubMed Central

    Wild, D

    1990-01-01

    Photolysis of arylazides in aqueous media was recently found to generate presumed nitrenium ions, species which are generally considered as the ultimate mutagens/carcinogens derived from arylamines and nitroarenes. The primary photolysis products of arylazides, the arylnitrenes, can possibly react as electrophiles themselves, or they can be protonated and thus form the electrophilic nitrenium ions. Numerous arylazides and aryldiazides can be photoactivated to short-lived mutagens detectable in Salmonella typhimurium TA98. Structure-activity comparisons between arylazides and the matching arylamines and nitroarenes show correlations; e.g., phenyl azide and methyl-substituted phenyl azides are not mutagenic or only weakly mutagenic like aniline, nitrobenzene, and their methyl homologues, whereas 4-azidodiphenyl, 2-azidofluorene, 1-azidopyrene, azido-IQ, and azido-isoIQ are increasingly mutagenic in that order, like the matching amino and nitro compounds. It is hypothesized on the basis of these data that the nitrene/nitrenium ion is the reactive intermediate common to the three mutagenic pathways and that the reaction of the nitrene/nitrenium ion with DNA is rate limiting for the overall mutagenic process in Salmonella. The photochemical generation from arylazides of the reactive species, the nitrene/nitrenium ions, opens new perspectives for the understanding of the genotoxic activity of arylamines and nitroarenes in general and, specifically, of the food mutagens/carcinogens of the IQ type. PMID:2272323

  16. The Ultimate Emission Line Diagnostics Study at z=1.4

    NASA Astrophysics Data System (ADS)

    Rigby, Jane

    2015-10-01

    We propose the ultimate WFC3 grism spectroscopy, in terms of spatial resolution, signal-to-noise ratio, and diagnostic emission line coverage, at z=1.4. The targets are two extremely bright lensed galaxies at redshifts of 1.329 and 1.420. These redshifts place all of rest-frame optical diagnostic emission lines, from [O II] 3727 to [S II] 6731 A, in the WFC3 G102 and G141 grisms. On spatial scales down to 100~pc, we will map the star formation rate, metallicity, extinction, and excitation across these two galaxies, and thereby measure not only the physical conditions of star formation, but how those conditions vary spatially. For the target that currently lacks HST and Spitzer imaging, we propose 2 orbits of WFC3/UVIS imaging to enable creation of a lensing map, and 1~hr of Spitzer to obtain a stellar mass estimate. This program will be a legacy for HST, the most rigorous in situ test yet of strong-line nebular line diagnostics in the distant universe, and will establish a benchmark for far larger grism surveys in which HST has invested some 700 orbits.

  17. Tunable dark plasmons in a metallic nanocube dimer: toward ultimate sensitivity nanoplasmonic sensors.

    PubMed

    Zhang, Shunping; Xu, Hongxing

    2016-07-14

    Metallic nanoparticles can function as label-free nanosensors monitoring the local dielectric environment in their close vicinity, thanks to the localized surface plasmon resonances. The sensing figure of merit is limited by the total loss rate of the plasmon. Here, we theoretically study a silver nanocube dimer and discover for the first time a dark plasmon with its total loss rate at the lower theoretical limit. It originates from the attractive coupling of the dipolar and quadrupolar mode in the individual nanocubes. It shows an unprecedented sensitivity to the interparticle gap distance, i.e., one ångström change in the gap distance results in a shift twice as large as the peak width. The sensing figure of merit using this dark plasmon is 56-61, reaching the ultimate value limited only by the material permittivity. The field of the mode is confined mainly within the gap region which is in the extreme deep subwavelength (3.5 × 10(-6)λ0(3)) region. Besides sensing applications, the dark plasmon also shows foreseeable potential in enhanced spectroscopy, nanolasers and other nanophotonic devices. PMID:27412788

  18. Tunable dark plasmons in a metallic nanocube dimer: toward ultimate sensitivity nanoplasmonic sensors

    NASA Astrophysics Data System (ADS)

    Zhang, Shunping; Xu, Hongxing

    2016-07-01

    Metallic nanoparticles can function as label-free nanosensors monitoring the local dielectric environment in their close vicinity, thanks to the localized surface plasmon resonances. The sensing figure of merit is limited by the total loss rate of the plasmon. Here, we theoretically study a silver nanocube dimer and discover for the first time a dark plasmon with its total loss rate at the lower theoretical limit. It originates from the attractive coupling of the dipolar and quadrupolar mode in the individual nanocubes. It shows an unprecedented sensitivity to the interparticle gap distance, i.e., one ångström change in the gap distance results in a shift twice as large as the peak width. The sensing figure of merit using this dark plasmon is 56-61, reaching the ultimate value limited only by the material permittivity. The field of the mode is confined mainly within the gap region which is in the extreme deep subwavelength (3.5 × 10-6λ03) region. Besides sensing applications, the dark plasmon also shows foreseeable potential in enhanced spectroscopy, nanolasers and other nanophotonic devices.

  19. Moisture absorption early postmortem predicts ultimate drip loss in fresh pork.

    PubMed

    Kapper, C; Walukonis, C J; Scheffler, T L; Scheffler, J M; Don, C; Morgan, M T; Forrest, J C; Gerrard, D E

    2014-02-01

    Water-holding capacity is the ability of meat to hold moisture and is subject to postmortem metabolism. The objective of this study was to characterize the loss of moisture from muscle postmortem and investigate whether these losses are useful in predicting the ultimate drip loss of fresh pork. Cotton-rayon absorptive-based devices were inserted in the longissimus dorsi muscles of pork carcasses (n = 51) postmortem and removed at various intervals for 24h. Greatest moisture absorption was observed at 105 min post exsanguination. Drip loss varied (0.6-15.3%) across carcasses. Individual absorption at 75 min correlated (r = 0.33) with final drip loss. Correlations improved using individual absorption values at 90 min (r = 0.48) and accumulated absorption values at 150 min (r = 0.41). Results show that significant moisture is lost from muscle tissue early postmortem and suggest that capture of this moisture may be useful in predicting final drip loss of fresh meat. PMID:24225387

  20. The ultimate technology: the end of technology and the task of nature.

    PubMed

    Riis, Søren

    2013-01-01

    One of the most influential philosophers of the 20th century, Martin Heidegger (1889-1976), died prior to the remarkable cloning of the sheep Dolly and before Dr. Venter started his experiments on creating synthetic life, and he never explicitly discussed living technologies. However, by reinterpreting his notion of "modern technology," this article shows how it is possible to philosophically assess living technologies and to recognize ways in which Heidegger anticipated this phenomenon with his notion of cybernetics. The interpretation elucidates the fundamental process of technology becoming living and simultaneously presents living technology as the ultimate technology. The thesis of this article is that living technology is not just one more technology; rather, it is the perfection of technology as understood by Aristotle. Aristotle's thinking is in this way a key example of a profound reassessment of nature and technology. Aristotle clearly separates these two domains of being in his definition, but in doing so, he also connects them to one another in a highly influential way. Following this line of thought, the article finally offers an original perspective involving renewed respect for the perpetual self-unfolding nature of living technology. PMID:23889743

  1. Fetal scalp pH testing

    MedlinePlus

    ... Normal pH: 7.25 to 7.35 Borderline pH: 7.20 to 7.25 The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some ...

  2. pH [Measure of Acidity].

    ERIC Educational Resources Information Center

    Henderson, Paula

    This autoinstructional program deals with the study of the pH of given substances by using litmus and hydrion papers. It is a learning activity directed toward low achievers involved in the study of biology at the secondary school level. The time suggested for the unit is 25-30 minutes (plus additional time for further pH testing). The equipment…

  3. pH. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    This lesson plan is intended for use in conducting classes on the effect of pH on plant growth. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about soil pH and its effect on plants. The following topics are among those discussed: acidity and alkalinity; the…

  4. Middle School and pH?

    ERIC Educational Resources Information Center

    Herricks, Susan

    2007-01-01

    A local middle school requested that the Water Center of Advanced Materials for Purification of Water With Systems (WaterCAMPWS), a National Science Foundation Science and Technology Center, provide an introduction to pH for their seventh-grade water-based service learning class. After sorting through a multitude of information about pH, a…

  5. Response to the "Responsive PhD"

    ERIC Educational Resources Information Center

    Huyssen, David

    2007-01-01

    In June 2005, 50 graduate school deans gathered at Princeton to address the fact that the number of new PhDs conferred each year far exceeds the number of tenure-track academic jobs on offer. Under the auspices of the Woodrow Wilson National Fellowship Foundation's Responsive PhD Project, these deans spoke passionately about how American…

  6. Inexpensive and Disposable pH Electrodes

    ERIC Educational Resources Information Center

    Goldcamp, Michael J.; Conklin, Alfred; Nelson, Kimberly; Marchetti, Jessica; Brashear, Ryan; Epure, Emily

    2010-01-01

    Inexpensive electrodes for the measurement of pH have been constructed using the ionophore tribenzylamine for sensing H[superscript +] concentrations. Both traditional liquid-membrane electrodes and coated-wire electrodes have been constructed and studied, and both exhibit linear, nearly Nernstian responses to changes in pH. Measurements of pH…

  7. Colorimetric determination of pH

    SciTech Connect

    Baumann, E.W.; Buchanan, B.R.

    1991-12-31

    There is a need for a simple, rapid, reliable means for determining pH values of concentrated, high salt solutions without reliance on human eye and ambient light. The method comprises the steps of preparing a set of reference solutions, measuring the light absorption by each reference solution, adding indicator dye to each reference solution, measuring the light absorption by each such reference mixture, comparing the two solutions to determine the dye color at each pH, normalizing the spectra of mixture to the isosbestic point, and matching the color of the pH of the solution to one of the colors of the pHs in the reference solution set. In this way, the pH can be determined to within 0.1 pH unit, a far more precise method than using the human eye.

  8. Intracellular pH modulates quinary structure

    PubMed Central

    Cohen, Rachel D; Guseman, Alex J; Pielak, Gary J

    2015-01-01

    NMR spectroscopy can provide information about proteins in living cells. pH is an important characteristic of the intracellular environment because it modulates key protein properties such as net charge and stability. Here, we show that pH modulates quinary interactions, the weak, ubiquitous interactions between proteins and other cellular macromolecules. We use the K10H variant of the B domain of protein G (GB1, 6.2 kDa) as a pH reporter in Escherichia coli cells. By controlling the intracellular pH, we show that quinary interactions influence the quality of in-cell 15N–1H HSQC NMR spectra. At low pH, the quality is degraded because the increase in attractive interactions between E. coli proteins and GB1 slows GB1 tumbling and broadens its crosspeaks. The results demonstrate the importance of quinary interactions for furthering our understanding of protein chemistry in living cells. PMID:26257390

  9. Determination Of Ph Including Hemoglobin Correction

    DOEpatents

    Maynard, John D.; Hendee, Shonn P.; Rohrscheib, Mark R.; Nunez, David; Alam, M. Kathleen; Franke, James E.; Kemeny, Gabor J.

    2005-09-13

    Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

  10. An ultrasensitive method of real time pH monitoring with complementary metal oxide semiconductor image sensor.

    PubMed

    Devadhasan, Jasmine Pramila; Kim, Sanghyo

    2015-02-01

    CMOS sensors are becoming a powerful tool in the biological and chemical field. In this work, we introduce a new approach on quantifying various pH solutions with a CMOS image sensor. The CMOS image sensor based pH measurement produces high-accuracy analysis, making it a truly portable and user friendly system. pH indicator blended hydrogel matrix was fabricated as a thin film to the accurate color development. A distinct color change of red, green and blue (RGB) develops in the hydrogel film by applying various pH solutions (pH 1-14). The semi-quantitative pH evolution was acquired by visual read out. Further, CMOS image sensor absorbs the RGB color intensity of the film and hue value converted into digital numbers with the aid of an analog-to-digital converter (ADC) to determine the pH ranges of solutions. Chromaticity diagram and Euclidean distance represent the RGB color space and differentiation of pH ranges, respectively. This technique is applicable to sense the various toxic chemicals and chemical vapors by situ sensing. Ultimately, the entire approach can be integrated into smartphone and operable with the user friendly manner.

  11. Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

    NASA Astrophysics Data System (ADS)

    Thomas, Zahra; Abbott, Benjamin W.; Troccaz, Olivier; Baudry, Jacques; Pinay, Gilles

    2016-03-01

    Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43-) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent

  12. BNL NONLINEAR PRE TEST SEISMIC ANALYSIS FOR THE NUPEC ULTIMATE STRENGTH PIPING TEST PROGRAM.

    SciTech Connect

    DEGRASSI,G.; HOFMAYER,C.; MURPHY,C.; SUZUKI,K.; NAMITA,Y.

    2003-08-17

    The Nuclear Power Engineering Corporation (NUPEC) of Japan has been conducting a multi-year research program to investigate the behavior of nuclear power plant piping systems under large seismic loads. The objectives of the program are: to develop a better understanding of the elasto-plastic response and ultimate strength of nuclear piping; to ascertain the seismic safety margin of current piping design codes; and to assess new piping code allowable stress rules. Under this program, NUPEC has performed a large-scale seismic proving test of a representative nuclear power plant piping system. In support of the proving test, a series of materials tests, static and dynamic piping component tests, and seismic tests of simplified piping systems have also been performed. As part of collaborative efforts between the United States and Japan on seismic issues, the US Nuclear Regulatory Commission (USNRC) and its contractor, the Brookhaven National Laboratory (BNL), are participating in this research program by performing pre-test and post-test analyses, and by evaluating the significance of the program results with regard to safety margins. This paper describes BNL's pre-test analysis to predict the elasto-plastic response for one of NUPEC's simplified piping system seismic tests. The capability to simulate the anticipated ratcheting response of the system was of particular interest. Analyses were performed using classical bilinear and multilinear kinematic hardening models as well as a nonlinear kinematic hardening model. Comparisons of analysis results for each plasticity model against test results for a static cycling elbow component test and for a simplified piping system seismic test are presented in the paper.

  13. Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

    NASA Astrophysics Data System (ADS)

    Thomas, Z.; Abbott, B. W.; Troccaz, O.; Baudry, J.; Pinay, G.

    2015-09-01

    Direct and indirect effects from agriculture, urbanization, and resource extraction have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. The capacity of a watershed to remove or retain nutrients is a function of biotic and abiotic conditions across the terrestrial-aquatic gradient including soil, groundwater, riparian zone, and surface water. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments. We analysed a five-year, high frequency water chemistry dataset from 3 catchments ranging from 2.3 to 10.8 km2 in northwestern France. Catchments differed in the relationship between hydrology and solute concentrations, associated with catchment characteristics such as hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness appeared to have greater transient storage and residence time, buffering the catchment to fluctuations in water chemistry, reflected in relatively invariant carbon and nutrient chemistry across hydrologic conditions. Conversely, the catchments with smoother, thinner soils responded to both intra- and inter-annual hydrologic variation with high concentrations of PO43- and NH4+ during low flow conditions and strong increases in DOC, sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land use) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on elemental fluxes is both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent catchment buffering capacity and probability of human

  14. Different Ultimate Factors Define Timing of Breeding in Two Related Species.

    PubMed

    Pakanen, Veli-Matti; Orell, Markku; Vatka, Emma; Rytkönen, Seppo; Broggi, Juli

    2016-01-01

    Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony). Alternatively, time-dependent breeding success (the date hypothesis) can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence), in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major) and the willow tit (Poecile montanus) by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider subsequent

  15. Development of adaptive seismic isolators for ultimate seismic protection of civil structures

    NASA Astrophysics Data System (ADS)

    Li, Jianchun; Li, Yancheng; Li, Weihua; Samali, Bijan

    2013-04-01

    Base isolation is the most popular seismic protection technique for civil engineering structures. However, research has revealed that the traditional base isolation system due to its passive nature is vulnerable to two kinds of earthquakes, i.e. the near-fault and far-fault earthquakes. A great deal of effort has been dedicated to improve the performance of the traditional base isolation system for these two types of earthquakes. This paper presents a recent research breakthrough on the development of a novel adaptive seismic isolation system as the quest for ultimate protection for civil structures, utilizing the field-dependent property of the magnetorheological elastomer (MRE). A novel adaptive seismic isolator was developed as the key element to form smart seismic isolation system. The novel isolator contains unique laminated structure of steel and MR elastomer layers, which enable its large-scale civil engineering applications, and a solenoid to provide sufficient and uniform magnetic field for energizing the field-dependent property of MR elastomers. With the controllable shear modulus/damping of the MR elastomer, the developed adaptive seismic isolator possesses a controllable lateral stiffness while maintaining adequate vertical loading capacity. In this paper, a comprehensive review on the development of the adaptive seismic isolator is present including designs, analysis and testing of two prototypical adaptive seismic isolators utilizing two different MRE materials. Experimental results show that the first prototypical MRE seismic isolator can provide stiffness increase up to 37.49%, while the second prototypical MRE seismic isolator provides amazing increase of lateral stiffness up to1630%. Such range of increase of the controllable stiffness of the seismic isolator makes it highly practical for developing new adaptive base isolation system utilizing either semi-active or smart passive controls.

  16. Different Ultimate Factors Define Timing of Breeding in Two Related Species.

    PubMed

    Pakanen, Veli-Matti; Orell, Markku; Vatka, Emma; Rytkönen, Seppo; Broggi, Juli

    2016-01-01

    Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony). Alternatively, time-dependent breeding success (the date hypothesis) can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence), in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major) and the willow tit (Poecile montanus) by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider subsequent

  17. Different Ultimate Factors Define Timing of Breeding in Two Related Species

    PubMed Central

    Pakanen, Veli-Matti; Orell, Markku; Vatka, Emma; Rytkönen, Seppo; Broggi, Juli

    2016-01-01

    Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species’ responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony). Alternatively, time-dependent breeding success (the date hypothesis) can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence), in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major) and the willow tit (Poecile montanus) by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider subsequent

  18. The psychiatrist's guide to right and wrong: Part IV: The insanity defense and the Ultimate Issue Rule.

    PubMed

    Goldstein, R L

    1989-01-01

    In the wake of Hinckley, widespread public dissatisfaction with the role of psychiatrists in insanity defense litigation prompted Congress in 1984 to amend the Federal Rules of Evidence to prohibit psychiatric testimony on the ultimate legal issue of whether or not a defendant is insane. APA's Statement on the Insanity Defense served as the ably articulated premise for this evidentiary amendment. APA argued that in going beyond their psychiatric expertise by answering ultimate issue questions as to whether defendants are legally insane, experts are likely to confuse the jury and undermine public confidence in psychiatry. APA also asserted that there was an impermissible logical leap between scientific psychiatric inquiry and moral-legal conclusions on the ultimate issue of insanity. This article reviews the origins, history, and vicissitudes of the Ultimate Issue Rule and analyzes the Statement on the Insanity Defense from both a legal and psychiatric perspective on the issue of whether psychiatrists should answer the ultimate question in insanity cases. The analysis suggests that APA's conclusions are not supported on scientific or evidentiary grounds, but may be warranted as a policy consideration to safeguard the public image of psychiatry.

  19. Ultimate Tensile Strength as a Function of Test Rate for Various Ceramic Matrix Composites at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Bansal, Narottam P.; Gyekenyesi, John P.

    2002-01-01

    Ultimate tensile strength of five different continuous fiber-reinforced ceramic composites, including SiC/BSAS (2D 2 types), SiC/MAS-5 (2D), SiC/SiC (2D enhanced), and C/SiC(2D) was determined as a function of test rate at I 100 to 1200 'C in air. All five composite materials exhibited a significant dependency of ultimate strength on test rate such that the ultimate strength decreased with decreasing test rate, similar to the behavior observed in many advanced monolithic ceramics at elevated temperatures. The application of the preloading technique as well as the prediction of life from one loading configuration (constant stress rate) to another (constant stress loading) for SiC/BSAS suggested that the overall macroscopic failure mechanism of the composites would be the one governed by a power-law type of damage evolution/accumulation, analogous to slow crack growth commonly observed in advanced monolithic ceramics.

  20. INFLUENCE OF JOINING LOCATIONS AND PLATE WIDTH ON ULTIMATE STRENGTH OF ALUMINUM ALLOY PLATES IN IN-PLANE BENDING

    NASA Astrophysics Data System (ADS)

    Okura, Ichiro; Ogasahara, Koji

    The ultimate strength of aluminum alloy plates in in-plane bending is investigated considering joining locations and plate width by the elastic-plastic large deflection analysis with FEM. The aluminum alloys taken into account are heat-treated A6061-T6 and A6005C-T5 and non-heat-treated A5083-O. The softening of material and the residual stresses caused by the friction stir welding (FSW) and the MIG welding are introduced in the analysis. It is shown that the joining locations and the width of plate have a great influence on the ultimate strength. The formula which gives the curves for the ultimate strength of plates in in-plane bending considering joining locations and plate width are proposed, based on the results of the FEM analysis.

  1. Predictors of binge drinking in adolescents: ultimate and distal factors - a representative study

    PubMed Central

    2012-01-01

    Background As epidemiological surveys have shown, binge drinking is a constant and wide-spread problem behavior in adolescents. It is not rare to find that more than half of all adolescents engage in this behavior when assessing only the last 4 weeks of time independent of the urbanity of the region they live in. There have been several reviews on predictors of substance consumption in adolescents in general, but there has been less high quality research on predictors of binge drinking, and most studies have not been theoretically based. The current study aimed to analyze the ultimate and distal factors predicting substance consumption according to Petraitis' theory of triadic influence. We assessed the predictive value of these factors with respect to binge drinking in German adolescents, including the identification of influence direction. Methods In the years 2007/2008, a representative written survey of N = 44,610 students in the 9th grade of different school types in Germany was carried out (net sample). The return rate of questionnaires was 88% regarding all students whose teachers or school directors had agreed to participate in the study. In this survey, prevalence of binge drinking was investigated as well as potential predictors from the social/interpersonal, the attitudinal/environmental, and the intrapersonal fields (3 factors of Petraitis). In a multivariate logistic regression analysis, these variables were included after testing for multicollinearity in order to assess their ability to predict binge drinking. Results Prevalence of binge drinking in the last 30 days was 52.3% for the surveyed adolescents with a higher prevalence for boys (56.9%) than for girls (47.5%). The two most influential factors found to protect against binge drinking with p < .001 were low economic status and importance of religion. The four most relevant risk factors for binge drinking (p < .001) were life-time prevalence of school absenteeism/truancy, academic failure

  2. Proximate and Ultimate Compositional Changes in Corn Stover during Torrefaction using Thermogravimetric Analyzer and Microwaves

    SciTech Connect

    Jaya Shankar Tumuluru

    2012-07-01

    regular and microwaves and their effect on proximate and ultimate composition. Studies indicated that microwave torrefaction is a good way to torrefy the biomass in short periods of time. A maximum calorific value of 21 MJ/kg is achievable at 6 min residence time compared to 15 min using the dry torrefaction technique. Increasing the residence time increased the carbon content where a maximum carbon content of 52.20 % was achievable at lower residence time. The loss of volatiles is comparatively lower compared to dry torrefaction technique. Moisture content of microwave torrefied samples was in between 2-2.5 % (w.b).

  3. Stimulus-secretion coupling in beta-cells: modulation by pH.

    PubMed

    Pace, C S; Tarvin, J T; Smith, J S

    1983-01-01

    We have examined the influence of changes in pH on the oscillatory pattern of electrical activity (EA) in the beta-cell by altering medium pH (pHo) and using permeable weak buffers to alter intracellular pH (pHi). A decrease in pH in the presence of glucose elicited depolarization to the active phase and constant spike activity, whereas an increase in pH elicited a decrease in spike activity or silent hyperpolarization. On inhibition of HCO3:Cl antiport by addition of DIDS (4,4'-diisothiocyano-2,2'-stilbene disulfonic acid), probenecid, or withdrawal of medium HCO-3, there was an increase in the duration of the active phase. A similar result was obtained on the inhibition of Na:H antiport by the addition of amiloride or the reduction of medium [Na+]. The influence of H+ and glucose has been proposed to decrease K+ permeability (PK). However, the influence of pH on 86Rb+ efflux was most effective at subthreshold or 4.2 mM glucose; only a moderate decrease in PK occurred at 8.3 mM glucose, and no effect was obtained at 16.7 mM glucose. Alteration of pHi, and not pHo, induces similar effects on glucose-induced electrical and secretory events. There is a clear dissociation between the influence of inhibitors of the Na:H and HCO3:Cl antiporters on the electrical and secretory events. DIDS and amiloride increased glucose-induced EA, but markedly inhibited the secretory response to glucose. It is evident that pH modulates the electrical events and cationic fluxes and ultimately influences the transduction of information to the mechanisms controlling the secretory process in the beta-cell. PMID:6295181

  4. Brenda K. Edwards, PhD

    Cancer.gov

    Brenda K. Edwards, PhD, has been with the Surveillance Research Program (SRP) and its predecessor organizations at the National Cancer Institute (NCI) since 1989, serving as SRP’s Associate Director from 1990-2011.

  5. Engineering fluorescent proteins towards ultimate performances: lessons from the newly developed cyan variants

    NASA Astrophysics Data System (ADS)

    Mérola, Fabienne; Erard, Marie; Fredj, Asma; Pasquier, Hélène

    2016-03-01

    New fluorescent proteins (FPs) are constantly discovered from natural sources, and submitted to intensive engineering based on random mutagenesis and directed evolution. However, most of these newly developed FPs fail to achieve all the performances required for their bioimaging applications. The design of highly optimised FP-based reporters, simultaneously displaying appropriate colour, multimeric state, chromophore maturation, brightness, photostability and environmental sensitivity will require a better understanding of the structural and dynamic determinants of FP photophysics. The recent development of cyan fluorescent proteins (CFPs) like mCerulean3, mTurquoise2 and Aquamarine brings a different view on these questions, as in this particular case, a step by step evaluation of critical mutations has been performed within a family of spectrally identical and evolutionary close variants. These efforts have led to CFPs with quantum yields close to unity, near single exponential emission decays, high photostability and complete insensitivity to pH, making them ideal choices as energy transfer donors in FRET and FLIM imaging applications. During this process, it was found that a proper amino-acid choice at only two positions (148 and 65) is sufficient to transform the performances of CFPs: with the help of structural and theoretical investigations, we rationalise here how these two positions critically control the CFP photophysics, in the context of FPs derived from the Aequorea victoria species. Today, these results provide a useful toolbox for upgrading the different CFP donors carried by FRET biosensors. They also trace the route towards the de novo design of FP-based optogenetic devices that will be perfectly tailored to dedicated imaging and sensing applications.

  6. Bifunctional Probes of Cathepsin Protease Activity and pH Reveal Alterations in Endolysosomal pH during Bacterial Infection.

    PubMed

    Sanman, Laura E; van der Linden, Wouter A; Verdoes, Martijn; Bogyo, Matthew

    2016-07-21

    Cysteine cathepsins are lysosomal proteases involved in regulation of both normal cellular processes and disease. Biochemical studies with peptide substrates indicate that cathepsins have optimal activity at acidic pH and highly attenuated activity at neutral pH. In contrast, there is mounting evidence that cathepsins have biological roles in environments that have non-acidic pH. To further define the specific pH environments where cathepsins act, we designed bifunctional activity-based probes (ABPs) that allow simultaneous analysis of cathepsin protease activity and pH. We use these probes to analyze the steady-state environment of cathepsin activity in macrophages and to measure dynamic changes in activity and pH upon stimulation. We show that Salmonella typhimurium induces a change in lysosomal pH that ultimately impairs cathepsin activity in both infected cells and a fraction of bystander cells, highlighting a mechanism by which Salmonella can simultaneously flourish within host cells and alter the behavior of nearby uninfected cells.

  7. 26 CFR 48.6427-9 - Diesel fuel and kerosene; claims by registered ultimate vendors (farming and State use).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Diesel fuel and kerosene; claims by registered ultimate vendors (farming and State use). 48.6427-9 Section 48.6427-9 Internal Revenue INTERNAL REVENUE... buyer, is in substantially the same form as the model certificate provided in paragraph (e)(2)(ii)...

  8. PROXIMATE OR ULTIMATE GENOTOXIC FORMS OF ARSENIC: METHYLATED ARSENIC(III) SPECIES THAT REACT DIRECTLY WITH DNA

    EPA Science Inventory


    PROXIMATE OR ULTIMATE GENOTOXIC FORMS OF ARSENIC: METHYLATED ARSENIC(III) SPECIES THAT REACT DIRECTL Y WITH DNA.

    Abstract:

    Although inorganic arsenic (iAs), arsenite or arsenate, is genotoxic, there has been no demonstration that iAs or a methylated metabolite...

  9. Ultimate Attainment in Late Second Language Acquisition: Phonetic and Grammatical Challenges in Advanced Dutch-English Bilingualism

    ERIC Educational Resources Information Center

    Schmid, Monika S.; Gilbers, Steven; Nota, Amber

    2014-01-01

    The present article provides an exploration of ultimate attainment in second language (L2) and its limitations. It is argued that the question of maturational constraints can best be investigated when the reference population is bilingual and exposed on a regular basis to varieties of their first language (L1) that show cross-linguistic influence.…

  10. Ultimate recovery analysis by formation and play for deep Anadarko Basin and estimation of undiscovered gas potential

    SciTech Connect

    Hugman, R.H.

    1988-01-01

    Deep gas resources have assumed a growing role in the United States gas picture since the mid-1960s. The deep Anadarko basin has been one of the areas of heavy activity, and is thought to contain a significant portion of the remaining unproven deep gas resource in the lower-48 states. A detailed analysis of gas production and proven reserves in the deep basin has established the characteristics and historical importance of each of the major plays and productive formations. The analysis should prove to be a valuable tool in estimating the undiscovered gas potential of the deep basin. Through 1985, there were 908 completions in the deep Anadarko basin. These completions accounted for 6.10 tcf of proven ultimate recovery, an average of 6.72 bcf per completion. In general, there is one completion per well and one well per section. Thus, ultimate recovery per completion represents ultimate recovery per section. The Hunton Group has the highest mean ultimate recovery at 15.3 bcf, followed by the Arbuckle Group at 10.1 bcf. In an attempt to evaluate existing resource appraisals of the deep basin, the areal distribution of production by formation was determined for the mature, shallow part of the basin. Over 20,000 completions were included in this analysis, demonstrating a significant database application. By using this distribution as a guide, along with certain other constraints, a range of 15-47 tcf of undiscovered potential was estimated.

  11. Queerspawn Speak out: A Review of "Let's Get This Straight: The Ultimate Handbook for Youth with LGBTQ Parents"

    ERIC Educational Resources Information Center

    Ryan, Caitlin L.

    2012-01-01

    "Let's Get This Straight: The Ultimate Handbook for Youth With LGBTQ Parents" provides an engaging and accessible set of tools for youth from LGBTQ-headed families. The stories and resources shared encourage these youth to take pride in their families, value their diverse experiences, and work against homophobia, transphobia, and other forms of…

  12. Education-Based Incarceration and Recidivism: The Ultimate Social Justice Crime Fighting Tool. Educational Leadership for Social Justice

    ERIC Educational Resources Information Center

    Fitch, Brian D., Ed.; Normore, Anthony H., Ed.

    2012-01-01

    Education-Based Incarceration and Recidivism: The Ultimate Social Justice Crime Fighting Tool takes a penetrating look at the needs and challenges of society's disenfranchised jail populations. It is incumbent to encourage public awareness of the causes that underlie the destructive cycles plaguing these populations, including the abuse and…

  13. Total flavones of Hippophae rhamnoides promotes early restoration of ultimate stress of healing patellar tendon in a rat model.

    PubMed

    Fu, S C; Hui, C W C; Li, L C; Cheuk, Y C; Qin, L; Gao, J; Chan, K-M

    2005-05-01

    Traditional Chinese herbal medicine has long been used for treatment of tendon injuries. Comparing to the modern way of treatments, Traditional Chinese medicine also stresses on strategies to promote the inherent healing capacity of tendons. Hippophae rhamnoides, known as Shaji, is one of Chinese herbal drugs that are traditionally used to promote tendon and ligament injuries. The total flavones of H. rhamnoides (TFH), with major constituents including quercetin, isorhamnetin and kaempferol, have been demonstrated with most of the bioactive properties of Shaji. In the present study, we evaluated the potential effect of TFH in the restoration of ultimate stress of healing patellar tendon in a well-established gap wound model in rats. A 0.1 mg TFH was injected to wound 1 day after the injury, and the ultimate stress of the healing tendon was measured at day 14 post-injury. The results showed that the ultimate stress of the healing tendon was significantly promoted by injection of TFH, increasing from 30 to 50% as compared to saline control. Excessive fibrotic response was not found in TFH-treated animals, but an enhanced collagen deposition and a better fibre alignment were observed. The results suggest that TFH may improve the ultimate stress of healing tendons at early stages, which implies possible earlier rehabilitation programme and better recovery. PMID:15823472

  14. 26 CFR 48.6420-1 - Credits or payments to ultimate purchaser of gasoline used on a farm.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... gasoline used on a farm. 48.6420-1 Section 48.6420-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... § 48.6420-1 Credits or payments to ultimate purchaser of gasoline used on a farm. (a) In general. If gasoline is used on a farm for farming purposes after June 30, 1965, a credit (under the...

  15. 26 CFR 48.6421-1 - Credits or payments to ultimate purchaser of gasoline used for certain nonhighway purposes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... gasoline used for certain nonhighway purposes. 48.6421-1 Section 48.6421-1 Internal Revenue INTERNAL... Manufacturers Taxes § 48.6421-1 Credits or payments to ultimate purchaser of gasoline used for certain nonhighway purposes. (a) In general. (1) If gasoline is used in a qualified business use or as fuel in...

  16. 26 CFR 48.6420-1 - Credits or payments to ultimate purchaser of gasoline used on a farm.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... gasoline used on a farm. 48.6420-1 Section 48.6420-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... § 48.6420-1 Credits or payments to ultimate purchaser of gasoline used on a farm. (a) In general. If gasoline is used on a farm for farming purposes after June 30, 1965, a credit (under the...

  17. 26 CFR 48.6421-1 - Credits or payments to ultimate purchaser of gasoline used for certain nonhighway purposes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... gasoline used for certain nonhighway purposes. 48.6421-1 Section 48.6421-1 Internal Revenue INTERNAL... Manufacturers Taxes § 48.6421-1 Credits or payments to ultimate purchaser of gasoline used for certain nonhighway purposes. (a) In general. (1) If gasoline is used in a qualified business use or as fuel in...

  18. 26 CFR 48.6421-1 - Credits or payments to ultimate purchaser of gasoline used for certain nonhighway purposes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... gasoline used for certain nonhighway purposes. 48.6421-1 Section 48.6421-1 Internal Revenue INTERNAL... Manufacturers Taxes § 48.6421-1 Credits or payments to ultimate purchaser of gasoline used for certain nonhighway purposes. (a) In general. (1) If gasoline is used in a qualified business use or as fuel in...

  19. ARSENIC (III) METHYLATED SPECIES REACT WITH DNA DIRECTLY AND COULD BE PROXIMATED/ULTIMATE GENOTOXIC FORMS OF ARSENIC

    EPA Science Inventory


    ARSENIC(III) METHYLATED SPECIES REACT WITH DNA DIRECTL Y AND COULD BE PROXIMATE/ULTIMATE GENOTOXIC FORMS OF ARSENIC


    Arsenite and arsenate (iAs, inorganic arsenic) have been thought to act as genotoxicants without reacting directly with DNA; neither iAs nor As(V) m...

  20. Eukaryotic diversity at pH extremes.

    PubMed

    Amaral-Zettler, Linda A

    2012-01-01

    Extremely acidic (pH < 3) and extremely alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline extremes and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH extreme sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the extremely acidic environments, and the ciliate Frontonia across the extremely alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH extremes over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations.

  1. Eukaryotic diversity at pH extremes

    PubMed Central

    Amaral-Zettler, Linda A.

    2013-01-01

    Extremely acidic (pH < 3) and extremely alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline extremes and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH extreme sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the extremely acidic environments, and the ciliate Frontonia across the extremely alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH extremes over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations. PMID:23335919

  2. MRF with adjustable pH

    NASA Astrophysics Data System (ADS)

    Jacobs, Stephen D.

    2011-10-01

    Deterministic final polishing of high precision optics using sub-aperture processing with magnetorheological finishing (MRF) is an accepted practice throughout the world. A wide variety of materials can be successfully worked with aqueous (pH 10), magnetorheological (MR) fluids, using magnetic carbonyl iron (CI) and either ceria or nanodiamond nonmagnetic abrasives. Polycrystalline materials like zinc sulfide (ZnS) and zinc selenide (ZnSe) are difficult to polish at pH 10 with MRF, due to their grain size and the relatively low stiffness of the MR fluid lap. If microns of material are removed, the grain structure of the material begins to appear. In 2005, Kozhinova et al. (Appl. Opt. 44 4671-4677) demonstrated that lowering pH could improve MRF of ZnS. However, magnetic CI particle corrosion rendered their low pH approach unstable and unsuitable for commercial implementation. In 2009, Shafrir et al. described a sol-gel coating process for manufacturing a zirconia-coated CI particle that protects the magnetic core from aqueous corrosion (Appl. Opt .48 6797-6810). The coating process produces free nanozirconia polishing abrasives during the coating procedure, thereby creating an MR polishing powder that is "self-charged" with the polishing abrasive. By simply adding water, it was possible to polish optical glasses and ceramics with good stability at pH 8 for three weeks. The development of a corrosion resistant, MR polishing powder, opens up the possibility for polishing additional materials, wherein the pH may be adjusted to optimize effectiveness. In this paper we describe the CI coating process, the characterization of the coated powder, and procedures for making stable MR fluids with adjustable pH, giving polishing results for a variety of optical glasses and crystalline ceramics.

  3. Immobilized pH gradients (IPG) simulator--an additional step in pH gradient engineering: II. Nonlinear pH gradients.

    PubMed

    Righetti, P G; Tonani, C

    1991-12-01

    While in the companion paper (Tonani, C. & Righetti, P. G., Electrophoresis 1991, 12, 1011-1021) we gave the general outline of our new computer program, immobilized pH gradients (IPG) simulator, able to simulate and optimize linear pH gradients for isoelectric focusing in immobilized pH gradients, in the present report we extend the application of such a program to: (i) convex exponential gradients, (ii) logarithmic and (iii) polynomial gradients. Such gradients are meant to give equal space to protein spots in complex protein mixtures (e.g., cell lysates, biological fluids) and follow the statistical distribution of protein pI values along the pH axis. They will prove of fundamental importance in two-dimensional maps, both because they optimize the spreading of spots in the two-dimensional plane and because of the excellent reproducibility of immobilized pH gradients. The following concave exponential recipes are given: pH 3-8, pH 3-9, pH 3-10, pH 3-11, pH 4-7, pH 4-8, pH 4-9, pH 4-10, pH 4-11, pH 5-8, pH 5-9, and pH 5-10, as well as the most extended pH 2.5-11 interval. Two interesting logarithmic gradients are described: pH 3-6 and pH 3-7 and one sigmoidal (derived with a polynomial of 5th degree): pH 3-11.

  4. Acid-induced folding of yeast alcohol dehydrogenase under low pH conditions.

    PubMed

    Le, W P; Yan, S X; Zhang, Y X; Zhou, H M

    1996-04-01

    Under conditions of low pH, the conformational states of holo-YADH and apo-YADH were examined by protein intrinsic fluorescence, ANS fluorescence, and far-UV CD measurements. The results obtained show that a low ionic strength, with the addition of HCl, the holo- and apo- YADH denatured gradually to reach the ultimate unfolded conformation in the vicinity of pH 2.0 and 2.5, respectively. With the decrease of pH from 7.0 to 2.0, the fluorescence emission decreased markedly, with its emission maximum red-shifting from 335 to 355 nm, indicating complete exposure of the buried tryptophan residues to the solvent. The far-UV CD spectra show the loss of the arrayed secondary structure, though the acid-denatured enzyme still maintained a partially arrayed secondary structure. A further decrease in pH by increasing the concentration of HClO4 induced a cooperative folding of the denatured enzyme to a compact conformation with the properties of a molten globule, described previously by Goto et al. [Proc. Natl. Acad. Sci. USA 87, 573-577 (1990)]. More extensive studies showed that although apo-YADH and holo-YADH exhibited similar behavior, the folding cooperative ability of apo-YADH was lower than that of the holo-enzyme. From the above results, it is suggested that the zinc ion plays an important role in the proper folding of YADH and in stabilizing its native conformation.

  5. Getting “Just Deserts” or Seeing the “Silver Lining”: The Relation between Judgments of Immanent and Ultimate Justice

    PubMed Central

    Harvey, Annelie J.; Callan, Mitchell J.

    2014-01-01

    People can perceive misfortunes as caused by previous bad deeds (immanent justice reasoning) or resulting in ultimate compensation (ultimate justice reasoning). Across two studies, we investigated the relation between these types of justice reasoning and identified the processes (perceptions of deservingness) that underlie them for both others (Study 1) and the self (Study 2). Study 1 demonstrated that observers engaged in more ultimate (vs. immanent) justice reasoning for a “good” victim and greater immanent (vs. ultimate) justice reasoning for a “bad” victim. In Study 2, participants' construals of their bad breaks varied as a function of their self-worth, with greater ultimate (immanent) justice reasoning for participants with higher (lower) self-esteem. Across both studies, perceived deservingness of bad breaks or perceived deservingness of ultimate compensation mediated immanent and ultimate justice reasoning respectively. PMID:25036011

  6. Cementitious porous pavement in stormwater quality control: pH and alkalinity elevation.

    PubMed

    Kuang, Xuheng; Sansalone, John

    2011-01-01

    A certain level of alkalinity acts as a buffer and maintains the pH value in a stable range in water bodies. With rapid urban development, more and more acidic pollutants flow to watersheds with runoff and drop alkalinity to a very low level and ultimately degrade the water environment. Cementitious porous pavement is an effective tool for stormwater acidic neutralization. When stormwater infiltrates cement porous pavement (CPP) materials, alkalinity and pH will be elevated due to the basic characteristics of cement concrete. The elevated alkalinity will neutralize acids in water bodies and maintain the pH in a stable level as a buffer. It is expected that CPP materials still have a certain capability of alkalinity elevation after years of service, which is important for CPP as an effective tool for stormwater management. However, few previous studies have reported on how CPP structures would elevate runoff alkalinity and pH after being exposed to rainfall-runoff for years. In this study, three groups of CPP specimens, all exposed to rainfall-runoff for 3 years, were used to test the pH and alkalinity elevation properties. It was found that runoff pH values were elevated from 7.4 to the range of 7.8-8.6 after infiltrating through the uncoated specimens, and from 7.4 to 8.5-10.7 after infiltrating through aluminum-coated specimens. Runoff alkalinity elevation efficiencies are 11.5-14.5% for uncoated specimens and 42.2% for coated specimens. The study shows that CPP is an effective passive unit operation for stormwater acid neutralization in our built environment.

  7. pH fluorescent probes: chlorinated fluoresceins.

    PubMed

    Ge, Feng-Yan; Chen, Li-Gong

    2008-01-01

    A series of regiospecific chlorinated fluoresceins have been synthesized by the reaction of the regiospecific chlorinated resorcinols with chlorinated phthalic anhydride. The regioisomers were successfully separated by chromatography. The photophysical properties of the obtained chlorinated fluoresceins were examined and found their absorption and emission maxima at long wavelength with high fluorescence quantum yield. Especially, pH-dependent properties of chlorinated fluoresceins have been studied in detail. These compounds show strongly pH-sensitive range of 3.5-7.0, and have lower pK (a) values than fluorescein. Furthermore, their fluorescent intensity could reach the maximum in the physiological environment of pH range 6.8-7.4. Due to higher fluorescence quantum yield and lower pK (a) values, chlorinated fluoresceins will be expected to be used as excellent pH fluorescent probes for pH measurement of the acidic cell.

  8. Pattern recognition of ocean pH

    NASA Astrophysics Data System (ADS)

    Parker, Albert

    2016-09-01

    The manuscript shows how the few, scattered, latest measurements of ocean pH lacking a proper spatial and time coverage do not permit a meaningful computation of global trends, as the ocean pH is strongly variable in latitude, longitude and depth and very likely is subject to the multi-decadal oscillations that have been identified in the atmospheric and ocean systems. The proposed mathematical model is based on the assumption that the monthly averaged ocean pH may be described by the superposition of a linear trend and inter-annual, decadal and multi-decadal oscillations, with linear and sinusoidal regression coefficients requiring data that are presently unavailable.

  9. Ratiometric imaging of pH probes.

    PubMed

    Grillo-Hill, Bree K; Webb, Bradley A; Barber, Diane L

    2014-01-01

    Measurement of intracellular pH can be readily accomplished using tools and methods described in this chapter. We present a discussion of technical considerations of various ratiometric pH-sensitive probes including dyes and genetically encoded sensors. These probes can be used to measure pH across physical scales from macroscopic whole-mount tissues down to organelles and subcellular domains. We describe protocols for loading pH-sensitive probes into single cells or tissues and discuss ratiometric image acquisition and analysis.

  10. Evaluation of fluorimetric pH sensors for bioprocess monitoring at low pH.

    PubMed

    Janzen, Nils H; Schmidt, Michael; Krause, Christian; Weuster-Botz, Dirk

    2015-09-01

    Optical chemical sensors are the standard for pH monitoring in small-scale bioreactors such as microtiter plates, shaking flasks or other single-use bioreactors. The dynamic pH range of the so far commercially available fluorescent pH sensors applied in small-scale bioreactors is restricted to pH monitoring around neutral pH, although many fermentation processes are performed at pH < 6 on industrial scale. Thus, two new prototype acidic fluorescence pH sensors immobilized in single-use stirred-tank bioreactors, one with excitation at 470 nm and emission at 550 nm (sensor 470/550) and the other with excitation at 505 nm and emission at 600 nm (sensor 505/600), were characterized with respect to dynamic ranges and operational stability in representative fermentation media. Best resolution and dynamic range was observed with pH sensor 505/600 in mineral medium (dynamic range of 3.9 < pH < 7.2). Applying the same pH sensors to complex medium results in a drastic reduction of resolution and dynamic ranges. Yeast extract in complex medium was found to cause background fluorescence at the sensors' operating wavelength combinations. Optical isolation of the sensor by adding a black colored polymer layer above the sensor spot and fixing an aperture made of adhesive photoresistant foil between the fluorescence reader and the transparent bottom of the polystyrene reactors enabled full re-establishment of the sensor's characteristics. Reliability and operational stability of sensor 505/600 was shown by online pH monitoring (4.5 < pH < 5.8) of parallel anaerobic batch fermentations of Clostridium acetobutylicum for the production of acetone, butanol and ethanol (ABE) with offline pH measurements with a standard glass electrode as reference. PMID:25969385

  11. Laser spark ignition of premixed methane-air mixtures: parameter measurements and determination of key factors for ultimate ignition results.

    PubMed

    Li, Xiaohui; Smith, Benjamin W; Omenetto, Nicoló

    2014-01-01

    In this study, we present an experimental investigation of the parameters of the laser spark ignition of premixed methane-air mixtures and the determination of the key factors for the ultimate ignition result. Ignition is achieved in a mesh honeycomb burner using the 1064 nm output of a neodymium-doped yttrium aluminum garnet (Nd : YAG) laser. All pertinent laser ignition parameters, including the minimum ignition energy, the ignition time and blow out time, and the effects that the variation of experimental conditions, such as the spark energy, ignition position, equivalence ratio (ER), and flow rate, have on these parameters have been addressed systematically. To identify the key factors for the ultimate result of laser ignition, several parameters of the ignition processes are measured simultaneously, with an emphasis given to the temporal behavior of the hydroxyl (OH) radicals in relation to the data regarding the spark energy and the local ER. A clear finding of the study is that successful ignition events are always related to higher OH radical photon emissions, considered to be proportional to the concentration level of the OH radicals present, thus indicating a direct link between the OH level at early times (on a microsecond scale) and the ultimate result of laser ignition. Two-dimensional correlation plots of the spark energy, local ER, and OH radical photon count at early times with the ultimate results of laser ignition indicate that the spark energy and local ER do not play a critical role in determining the success or failure of the ignition and that the OH concentration in the early time range is the key factor in determining the final fate of laser ignition. Finally, on the basis of the results obtained here and in the existing literature, some considerations of the mechanism of laser ignition are presented. PMID:25226251

  12. 26 CFR 48.6420-1 - Credits or payments to ultimate purchaser of gasoline used on a farm.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... For example, if a truck used on a farm for farming purposes is also used on the highways, gasoline... gasoline is used on a farm for farming purposes after June 30, 1965, a credit (under the circumstances... farming purposes,” “farm,” “gasoline,” “ultimate purchaser,” and “taxable year.” (b) Allowance of...

  13. 26 CFR 48.6420-1 - Credits or payments to ultimate purchaser of gasoline used on a farm.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... For example, if a truck used on a farm for farming purposes is also used on the highways, gasoline... gasoline is used on a farm for farming purposes after June 30, 1965, a credit (under the circumstances... farming purposes,” “farm,” “gasoline,” “ultimate purchaser,” and “taxable year.” (b) Allowance of...

  14. Monitoring fetal pH by telemetry

    NASA Technical Reports Server (NTRS)

    Blum, A.; Donahoe, T.; Jhabvala, M. D.; Ryan, W.

    1980-01-01

    Telemetry unit has been developed for possible use in measuring scalp-tissue pH and heart rate of unborn infant. Unit radius data to receiver as much as 50 ft. away. Application exists during hours just prior to childbirth to give warning of problems that might require cesarean delivery.

  15. Optoelectronic pH Meter: Further Details

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

    2009-01-01

    A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

  16. pH & Rate of Enzymatic Reactions.

    ERIC Educational Resources Information Center

    Clariana, Roy B.

    1991-01-01

    A quantitative and inexpensive way to measure the rate of enzymatic reaction is provided. The effects of different pH levels on the reaction rate of an enzyme from yeast are investigated and the results graphed. Background information, a list of needed materials, directions for preparing solutions, procedure, and results and discussion are…

  17. Development of sulfonamide AKT PH domain inhibitors

    PubMed Central

    Ahad, Ali Md.; Zuohe, Song; Du-Cuny, Lei; Moses, Sylvestor A.; Zhou, Li Li; Zhang, Shuxing; Powis, Garth; Meuillet, Emmanuelle J.; Mash, Eugene A.

    2011-01-01

    Disruption of the phosphatidylinositol 3-kinase/AKT signaling pathway can lead to apoptosis in cancer cells. Previously we identified a lead sulfonamide that selectively bound to the pleckstrin homology (PH) domain of AKT and induced apoptosis when present at low micromolar concentrations. To examine the effects of structural modification, a set of sulfonamides related to the lead compound was designed, synthesized, and tested for binding to the expressed PH domain of AKT using a surface plasmon resonance-based competitive binding assay. Cellular activity was determined by means of an assay for pAKT production and a cell killing assay using BxPC3 cells. The most active compounds in the set are lipophilic and possess an aliphatic chain of the proper length. Results were interpreted with the aid of computational modeling. This paper represents the first structure-activity relationship (SAR) study of a large family of AKT PH domain inhibitors. Information obtained will be used in the design of the next generation of inhibitors of AKT PH domain function. PMID:21353784

  18. Ph.D.'s and the Marketplace.

    ERIC Educational Resources Information Center

    Harvey, James

    Throughout the last decade, Ph.D. recipients were accustomed to a job market in which demand for their services far exceeded supply. During the same period, manpower experts predicted this situation would continue in the foreseeable future. However, when the 60's ended, the employment illusion had been rudely dispelled by frantic reports of a…

  19. Teaching Physics Using PhET Simulations

    ERIC Educational Resources Information Center

    Wieman, C. E.; Adams, W. K.; Loeblein, P.; Perkins, K. K.

    2010-01-01

    PhET Interactive Simulations (sims) are now being widely used in teaching physics and chemistry. Sims can be used in many different educational settings, including lecture, individual or small group inquiry activities, homework, and lab. Here we will highlight a few ways to use them in teaching, based on our research and experiences using them in…

  20. What My Ph.D. Taught Me

    ERIC Educational Resources Information Center

    Levenstein, Jessica

    2013-01-01

    The author started in the Ph.D. program in comparative literature at Princeton in 1992, a year after she graduated from college. She fell in love with mythology and the classical traditions and find herself teaching literature. In the remainder of her time at Princeton, she precepted for four or five more classes, got the chance to join the…

  1. The Economic Contribution of PhDs

    ERIC Educational Resources Information Center

    Casey, Bernard H.

    2009-01-01

    This paper looks at what the value of a doctorate is, both to employers in particular and to society and the economy at large. Given the emphasis many universities and funding agencies/governments are putting upon the development of PhD programmes, this is an issue deserving attention. The paper tries to show how two separate but interrelated…

  2. The Ph.D. Value Proposition

    ERIC Educational Resources Information Center

    Cooper, Kenneth J.

    2012-01-01

    Atlanta University launched its doctor of arts in humanities (DAH) programs almost 40 years ago, and, since the 1988 merger with Clark College, Clark Atlanta University has continued to award the degrees. This fall, for the first time, its students will be able to earn Ph.D.s in humanities instead. In DAH programs around the country, there's been…

  3. Effect of fast pH decline during the early postmortem period on calpain activity and cytoskeletal protein degradation of broiler M. pectoralis major.

    PubMed

    Huang, J C; Yang, J; Huang, F; Huang, M; Chen, K J; Xu, X L; Zhou, G H

    2016-10-01

    The objective of this study was to determine the effects of fast pH decline during the early postmortem period on calpain activity and the degradation of cytoskeletal proteins in broilers. Eighty broilers were randomly categorized into two groups: physical restraint (PR) and free struggle (FS). M. pectoralis major (PM) was used for determination of calpain activity, shear value, ultrastructure of myofibrils, and the degradation of desmin, titin, nebulin, and troponin-T. The pH (6.05) of FS group is significantly low than PR group (6.38) at 0.3 h postmortem. Fast pH decline during the early postmortem period led to a decrease of μ/m-calpain activities at 0.3 and 3 h postmortem (P < 0.05), but did not affect the ultimate μ/m-calpain activity. An initial fast decrease in pH increased the degradation of desmin, titin, nebulin, and increased the 30 kDa degradation fragments of troponin-T. Therefore, the fast pH decline during the early postmortem period decreased the μ/m-calpain activity and increased the degradation of cytoskeletal proteins in broiler muscle. It is possible that the fast pH decline experienced an earlier activation of calpains that resulted in earlier protein degradation and ultimately lower shear force.

  4. The pH of Enceladus' ocean

    NASA Astrophysics Data System (ADS)

    Glein, Christopher R.; Baross, John A.; Waite, J. Hunter

    2015-08-01

    Saturn's moon, Enceladus, is a geologically active waterworld. The prevailing paradigm is that there is a subsurface ocean that erupts to the surface, which leads to the formation of a plume of vapor and ice above the south polar region. The chemistry of the ocean is just beginning to be understood, but is of profound geochemical and astrobiological interest. Here, we determine the pH of the ocean using a thermodynamic model of carbonate speciation. Observational data from the Cassini spacecraft are used to make a chemical model of ocean water on Enceladus. The model suggests that Enceladus' ocean is a Na-Cl-CO3 solution with an alkaline pH of ∼11-12. The dominance of aqueous NaCl is a feature that Enceladus' ocean shares with terrestrial seawater, but the ubiquity of dissolved Na2CO3 suggests that soda lakes are more analogous to the Enceladus ocean. The high pH implies that the hydroxide ion should be relatively abundant, while divalent metals should be present at low concentrations owing to buffering by carbonates and phyllosilicates on the ocean floor. Carboxyl groups in dissolved organic species would be negatively charged, while amino groups would exist predominately in the neutral form. Knowledge of the pH improves our understanding of geochemical processes in Enceladus' ocean. The high pH is interpreted to be a key consequence of serpentinization of chondritic rock, as predicted by prior geochemical reaction path models; although degassing of CO2 from the ocean may also play a role depending on the efficiency of mixing processes in the ocean. Serpentinization leads to the generation of H2, a geochemical fuel that can support both abiotic and biological synthesis of organic molecules such as those that have been detected in Enceladus' plume. Serpentinization and H2 generation should have occurred on Enceladus, like on the parent bodies of aqueously altered meteorites; but it is unknown whether these critical processes are still taking place, or if

  5. Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification

    PubMed Central

    Stumpp, Meike; Hu, Marian Y.; Melzner, Frank; Gutowska, Magdalena A.; Dorey, Narimane; Himmerkus, Nina; Holtmann, Wiebke C.; Dupont, Sam T.; Thorndyke, Michael C.; Bleich, Markus

    2012-01-01

    Calcifying echinoid larvae respond to changes in seawater carbonate chemistry with reduced growth and developmental delay. To date, no information exists on how ocean acidification acts on pH homeostasis in echinoderm larvae. Understanding acid–base regulatory capacities is important because intracellular formation and maintenance of the calcium carbonate skeleton is dependent on pH homeostasis. Using H+-selective microelectrodes and the pH-sensitive fluorescent dye BCECF, we conducted in vivo measurements of extracellular and intracellular pH (pHe and pHi) in echinoderm larvae. We exposed pluteus larvae to a range of seawater CO2 conditions and demonstrated that the extracellular compartment surrounding the calcifying primary mesenchyme cells (PMCs) conforms to the surrounding seawater with respect to pH during exposure to elevated seawater pCO2. Using FITC dextran conjugates, we demonstrate that sea urchin larvae have a leaky integument. PMCs and spicules are therefore directly exposed to strong changes in pHe whenever seawater pH changes. However, measurements of pHi demonstrated that PMCs are able to fully compensate an induced intracellular acidosis. This was highly dependent on Na+ and HCO3−, suggesting a bicarbonate buffer mechanism involving secondary active Na+-dependent membrane transport proteins. We suggest that, under ocean acidification, maintained pHi enables calcification to proceed despite decreased pHe. However, this probably causes enhanced costs. Increased costs for calcification or cellular homeostasis can be one of the main factors leading to modifications in energy partitioning, which then impacts growth and, ultimately, results in increased mortality of echinoid larvae during the pelagic life stage. PMID:23077257

  6. What Is a pH Probe Study?

    MedlinePlus

    What is a pH Probe Study ? What is pH a probe study? M easuring the pH in the esophagus helps determine whether or not acid is coming up from the stomach. A pH probe study is usually done in patients where ...

  7. PH DEPENDENT TOXICITY OF FIVE METALS TO THREE MARINE ORGANISMS

    EPA Science Inventory

    The pH of natural marine systems is relatively stable; this may explain why metal toxicity changes with pH have not been well documented. However, changes in metal toxicity with pH in marine waters are of concern in toxicity testing. During porewater toxicity testing pH can chang...

  8. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  9. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  10. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  11. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  12. Sensing pH with TMCs.

    PubMed

    Spalthoff, Christian; Göpfert, Martin C

    2016-07-01

    Transmembrane channel-like (TMC) proteins have been implicated in hair cell mechanotransduction, Drosophila proprioception, and sodium sensing in the nematode C. elegans. In this issue of Neuron, Wang et al. (2016) report that C. elegans TMC-1 mediates nociceptor responses to high pH, not sodium, allowing the nematode to avoid strongly alkaline environments in which most animals cannot survive. PMID:27387645

  13. Not Your Father's Ph.D.

    ERIC Educational Resources Information Center

    Withrow, Brandon G.

    2008-01-01

    This article describes how the author, a devoted blogger, confronts his fear that his virtual life is damaging his career prospects in academe. As a new Ph.D. in religious studies, the author has every reason to believe he will find a tenure-track job. He has read the numbers and know that, on average, job candidates spend two to five years in…

  14. Complexation Key to a pH Locked Redox Reaction

    ERIC Educational Resources Information Center

    Rizvi, Masood Ahmad; Dangat, Yuvraj; Shams, Tahir; Khan, Khaliquz Zaman

    2016-01-01

    An unfavorable pH can block a feasible electron transfer for a pH dependent redox reaction. In this experiment, a series of potentiometric titrations demonstrate the sequential loss in feasibility of iron(II) dichromate redox reaction over a pH range of 0-4. The pH at which this reaction failed to occur was termed as a pH locked reaction. The…

  15. Pyrite oxidation at circumneutral pH

    NASA Astrophysics Data System (ADS)

    Moses, Carl O.; Herman, Janet S.

    1991-02-01

    Previous studies of pyrite oxidation kinetics have concentrated primarily on the reaction at low pH, where Fe(III) has been assumed to be the dominant oxidant. Studies at circumneutral pH, necessitated by effective pH buffering in some pyrite oxidation systems, have often implicitly assumed that the dominant oxidant must be dissolved oxygen (DO), owing to the diminished solubility of Fe(III). In fact, Fe(III)(aq) is an effective pyrite oxidant at circumneutral pH, but the reaction cannot be sustained in the absence of DO. The purpose of this experimental study was to ascertain the relative roles of Fe(III) and DO in pyrite oxidation at circumneutral pH. The rate of pyrite oxidation was first-order with respect to the ratio of surface area to solution volume. Direct determinations of both Fe(II) (aq)> and Fe(III) (aq) demonstrated a dramatic loss of Fe(II) from the solution phase in excess of the loss for which oxidation alone could account. Based on rate data, we have concluded that Fe(II) is adsorbed onto the pyrite surface. Furthermore, Fe(II) is preferred as an adsorbate to Fe(III), which we attribute to both electrostatic and acid-base selectivity. We also found that the rate of pyrite oxidation by either Fe(III) (aq) or DO is reduced in the presence of aqueous Fe(II), which leads us to conclude that, under most natural conditions, neither Fe(III) (aq) nor DO directly attacks the pyrite surface. The present evidence suggests a mechanism for pyrite oxidation that involves adsorbed Fe( II ) giving up electrons to DO and the resulting Fe(III) rapidly accepting electrons from the pyrite. The adsorbed Fe is, thus, cyclically oxidized and reduced, while it acts as a conduit for electrons traveling from pyrite to DO. Oxygen is transferred from the hydration sphere of the adsorbed Fe to pyrite S. The cycle of adsorbed Fe oxidation and reduction and the successive addition of oxygen to pyrite S continues until a stable sulfoxy species dissociates from the surface. Prior

  16. The Added Value of a PhD in Medicine--PhD Students' Perceptions of Acquired Competences

    ERIC Educational Resources Information Center

    Anttila, Henrika; Lindblom-Ylänne, Sari; Lonka, Kristi; Pyhältö, Kirsi

    2015-01-01

    PhD in the field of medicine is more common than in any other domain. Many medical doctors are driven towards PhD, but also students with other backgrounds (usually MSc) are conducting a PhD in medical schools. Higher education has invested a lot in developing generic and research competences. Still little is known about how PhD students…

  17. The Synergize effect of Chain extender to Phosporic acid catalyst to the ultimate property of Soy-Polyurethane

    NASA Astrophysics Data System (ADS)

    Elvistia Firdaus, Flora

    2016-04-01

    The polyurethanes (PUs) foam were made from vegetable oil; a soybean based polyol. The foams were categorized into flexible and semi rigid. This research is manufacturally designed polyurethane foams by a process requiring the reaction of mixture of 2, 4- and 2, 6-Toluene di Isocyanate isomers, soy polyol in the presence of other ingredients. The objective of this work was to functionalized soy-polyol using phosporic acid catalyst and chain extender, study their collaborative reaction in producing ultimate property of PU foam. Correlates the foam morphology images in accordance to mechanical properties of foams.

  18. Material Properties Test to Determine Ultimate Strain and True Stress-True Strain Curves for High Yield Steels

    SciTech Connect

    K.R. Arpin; T.F. Trimble

    2003-04-01

    This testing was undertaken to develop material true stress-true strain curves for elastic-plastic material behavior for use in performing transient analysis. Based on the conclusions of this test, the true stress-true strain curves derived herein are valid for use in elastic-plastic finite element analysis for structures fabricated from these materials. In addition, for the materials tested herein, the ultimate strain values are greater than those values cited as the limits for the elastic-plastic strain acceptance criteria for transient analysis.

  19. Family Size Preferences in Europe and USA: Ultimate Expected Number of Children. Comparative Studies Number 26: ECE Analyses of Surveys in Europe and USA.

    ERIC Educational Resources Information Center

    Berent, Jerzy

    This survey analysis compares fertility levels in the United States and European countries, discusses socioeconomic influences in ultimate expected family size, and examines birth rate trends. The average number of ultimately expected children varies from 2.13 children per woman in Bulgaria to 2.80 in Spain. Eighty to 90 percent of U.S. and…

  20. Do sarcomere length, collagen content, pH, intramuscular fat and desmin degradation explain variation in the tenderness of three ovine muscles?

    PubMed

    Starkey, Colin P; Geesink, Geert H; Collins, Damian; Hutton Oddy, V; Hopkins, David L

    2016-03-01

    The longissimus (n=118) (LL), semimembranosus (n=104) (SM) and biceps femoris (n=134) (BF) muscles were collected from lamb and sheep carcases and aged for 5days (LL and SM) and 14days (BF) to study the impact of muscle characteristics on tenderness as assessed by shear force (SF) and sensory evaluation. The impact of gender, animal age, collagen content, sarcomere length (SL), desmin degradation, ultimate pH and intramuscular fat (IMF) on tenderness was examined. The main factors which influenced SF of the LL were IMF, SL and desmin degradation, but for sensory tenderness, IMF, ultimate pH and gender were the main factors. The SF and sensory tenderness of the SM was best predicted by the degree of desmin degradation. For the BF soluble collagen and animal age both influenced SF. Different factors affect tenderness across muscles and not one prediction model applied across all muscles equally well.

  1. Nanofluidic single-molecule sorting of DNA: a new concept in separation and analysis of biomolecules towards ultimate level performance

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takatoki; Fujii, Teruo

    2010-10-01

    Separation and separation-based analysis of biomolecules are fundamentally important techniques in the field of biotechnology. These techniques, however, depend on stochastic processes that intrinsically involve uncertainty, and thus it is not possible to achieve 100% separation accuracy. Theoretically, the ultimate resolution and sensitivity should be realized in a single-molecule system because of the deterministic nature of single-molecule manipulation. Here, we have proposed and experimentally demonstrated the concept of a 'single-molecule sorter' that detects and correctly identifies individual single molecules, realizing the ultimate level of resolution and sensitivity for any separation-based technology. The single-molecule sorter was created using a nanofluidic network consisting of a single inlet channel that branches off into multiple outlet channels. It includes two major functional elements, namely a single-molecule detection and identification element and a flow path switching element to accurately separate single molecules. With this system we have successfully demonstrated the world's first single-molecule sorting using DNA as a sample molecule. In the future, we hope to expand the application of such devices to comprehensive sorting of single-proteins from a single cell. We also believe that in addition to the single-molecule sorting method reported here, other types of single-molecule based processes will emerge and find use in a wide variety of applications.

  2. Manipulation of the ultimate pattern of polypyrrole film on self-assembled monolayer patterned substrate by negative or positive electrodeposition

    NASA Astrophysics Data System (ADS)

    Zhou, Feng; Liu, Zhilu; Yu, Bo; Chen, Miao; Hao, Jingcheng; Liu, Weimin; Xue, Qunji

    2004-07-01

    Micro printed self-assembled monolayer may lead to different ultimate patterns of polypyrrole (PPy) by way of positive or negative deposition in guiding the electrodeposition of pyrrole. This article gives a detailed investigation of the effects of experimental conditions on the ultimate patterns of the PPy films on self-assembled monolayer (SAM)-patterned silicon and gold substrates. The effects of the substrate surface electric properties and the nature of the solvent and supporting electrolyte on the selective deposition and the PPy film morphology are also discussed. As the results, negative deposition occurs on the octadecyltrichlorosilane (OTS)-covered area of semiconductor Si surface in non-aqueous acetonitrile solution and results in positive patterns, while positive deposition occurs in aqueous solution and gives birth to negative patterns. This is attributed to the accessibility of the monomer solution to the substrate surface. The electrodeposition preferentially occurs on the exposed area of a gold substrate, though the deposition on the octadecanthiol (ODT)-covered area is unavoidable due to the hydrophobic-hydrophobic interaction. The lypophilic properties of the deposited PPy can be modified by selecting different salts as the supporting electrolytes and doping different anions during the electrodeposition. Subsequently, the morphology of the electro-deposited PPy layer can be tailored making use of the interaction between the PPy oligomer and the surfaces of different chemical functionalities.

  3. Ultimately Reliable Pyrotechnic Systems

    NASA Technical Reports Server (NTRS)

    Scott, John H.; Hinkel, Todd

    2015-01-01

    This paper presents the methods by which NASA has designed, built, tested, and certified pyrotechnic devices for high reliability operation in extreme environments and illustrates the potential applications in the oil and gas industry. NASA's extremely successful application of pyrotechnics is built upon documented procedures and test methods that have been maintained and developed since the Apollo Program. Standards are managed and rigorously enforced for performance margins, redundancy, lot sampling, and personnel safety. The pyrotechnics utilized in spacecraft include such devices as small initiators and detonators with the power of a shotgun shell, detonating cord systems for explosive energy transfer across many feet, precision linear shaped charges for breaking structural membranes, and booster charges to actuate valves and pistons. NASA's pyrotechnics program is one of the more successful in the history of Human Spaceflight. No pyrotechnic device developed in accordance with NASA's Human Spaceflight standards has ever failed in flight use. NASA's pyrotechnic initiators work reliably in temperatures as low as -420 F. Each of the 135 Space Shuttle flights fired 102 of these initiators, some setting off multiple pyrotechnic devices, with never a failure. The recent landing on Mars of the Opportunity rover fired 174 of NASA's pyrotechnic initiators to complete the famous '7 minutes of terror.' Even after traveling through extreme radiation and thermal environments on the way to Mars, every one of them worked. These initiators have fired on the surface of Titan. NASA's design controls, procedures, and processes produce the most reliable pyrotechnics in the world. Application of pyrotechnics designed and procured in this manner could enable the energy industry's emergency equipment, such as shutoff valves and deep-sea blowout preventers, to be left in place for years in extreme environments and still be relied upon to function when needed, thus greatly enhancing safety and operational availability.

  4. Kepler, the Ultimate Aristotelian

    NASA Astrophysics Data System (ADS)

    Davis, A. E. L.

    A comparison is made between Aristotelian and Newtonian versions of Laws of Motion. Kepler was successful in proving the 2 laws of motion of a single planet - to the extent that agreement with a framework of theory constitutes a proof. Of course he invented his framework of causes after the event, to fit the motions that had been already been quantified - but it may seem to you that Kepler's mainly mechanistic way explanation could have been considered by his contemporaries just as reasonable as Newton's action at a distance. It could be now apprecated that there was a window of less than 50 years before Newton's total synthesis. No-one previously had had the motivation to create a system of "celestial physics" based on a judicious use of Aristotelian principles. Yet this is what Kepler achieved.

  5. The ultimate high tide

    SciTech Connect

    Dean, R.G. )

    1990-01-01

    This paper discusses the possible coastal impacts of a rise in sea level. Control measures that are available to coastal communities are emphasized, including pumping of seawater into the ground, replenishing beach sand, protection or moving of potable-water intakes, elevating roadways, and building dikes. Economics will determine which, if any, measures are reasonable at a particular site. There is an upward trend in the mean CO{sub 2} concentration and predictions about the greenhouse effect are creating a rising tide of concern.

  6. Towards the ultimate transistor

    NASA Astrophysics Data System (ADS)

    Natelson, Douglas

    2009-06-01

    The first transistor, made more than 60 years ago at Bell Labs, was a couple of inches across. Today, a typical laptop computer uses a processor chip that contains well over a billion transistors, each one with electrodes separated by less than 50 nm of silicon, which is less than a thousandth of the diameter of a human hair. This continual drive for miniaturization, with the density of transistors doubling roughly every two years, was first noted by Intel co-founder Gordon Moore in 1965, and has been such a mainstay of electronics development that it is now enshrined as "Moore's law". These billions of transistors are made by "top down" methods that involve depositing thin layers of materials, patterning nano-scale stencils and effectively carving away the unwanted bits. The incredible success of this approach is almost impossible to overstate. The end result is billions of individual components on a single chip, essentially all working perfectly and continuously for years on end. No other manufactured technology comes remotely close in reliability or cost-per-widget.

  7. Toward ultimate nanoplasmonics modeling.

    PubMed

    Solís, Diego M; Taboada, José M; Obelleiro, Fernando; Liz-Marzán, Luis M; García de Abajo, F Javier

    2014-08-26

    Advances in the field of nanoplasmonics are hindered by the limited capabilities of simulation tools in dealing with realistic systems comprising regions that extend over many light wavelengths. We show that the optical response of unprecedentedly large systems can be accurately calculated by using a combination of surface integral equation (SIE) method of moments (MoM) formulation and an expansion of the electromagnetic fields in a suitable set of spatial wave functions via fast multipole methods. We start with a critical review of volume versus surface integral methods, followed by a short tutorial on the key features that render plasmons useful for sensing (field enhancement and confinement). We then use the SIE-MoM to examine the plasmonic and sensing capabilities of various systems with increasing degrees of complexity, including both individual and interacting gold nanorods and nanostars, as well as large random and periodic arrangements of ∼1000 gold nanorods. We believe that the present results and methodology raise the standard of numerical electromagnetic simulations in the field of nanoplasmonics to a new level, which can be beneficial for the design of advanced nanophotonic devices and optical sensing structures.

  8. The Ultimate Practitioner

    ERIC Educational Resources Information Center

    Richardson, Joan

    2011-01-01

    A solid idea coupled with savvy marketing has enabled Rick DuFour's vision of professional learning communities to revolutionize how teachers work with each other. The author of 13 books and 80 articles has presented to an estimated quarter million educators over the last eight years and is beginning to reach beyond the U.S. with books and…

  9. Fasting - the ultimate diet?

    PubMed

    Johnstone, A M

    2007-05-01

    Adult humans often undertake acute fasts for cosmetic, religious or medical reasons. For example, an estimated 14% of US adults have reported using fasting as a means to control body weight and this approach has long been advocated as an intermittent treatment for gross refractory obesity. There are unique historical data sets on extreme forms of food restriction that give insight into the consequences of starvation or semi-starvation in previously healthy, but usually non-obese subjects. These include documented medical reports on victims of hunger strike, famine and prisoners of war. Such data provide a detailed account on how the body adapts to prolonged starvation. It has previously been shown that fasting for the biblical period of 40 days and 40 nights is well within the overall physiological capabilities of a healthy adult. However, the specific effects on the human body and mind are less clearly documented, either in the short term (hours) or in the longer term (days). This review asks the following three questions, pertinent to any weight-loss therapy, (i) how effective is the regime in achieving weight loss, (ii) what impact does it have on psychology? and finally, (iii) does it work long-term? PMID:17444963

  10. Science and Ultimate Reality

    NASA Astrophysics Data System (ADS)

    Barrow, John D.; Davies, Paul C. W.; Harper, Charles L., Jr.

    2004-06-01

    This preview of the future of physics comprises contributions from recognized authorities inspired by the pioneering work of John Wheeler. Quantum theory represents a unifying theme within the book, as it relates to the topics of the nature of physical reality, cosmic inflation, the arrow of time, models of the universe, superstrings, quantum gravity and cosmology. Attempts to formulate a final unification theory of physics are also considered, along with the existence of hidden dimensions of space, hidden cosmic matter, and the strange world of quantum technology. John Archibald Wheeler is one of the most influential scientists of the twentieth century. His extraordinary career has spanned momentous advances in physics, from the birth of the nuclear age to the conception of the quantum computer. Famous for coining the term "black hole," Professor Wheeler helped lay the foundations for the rebirth of gravitation as a mainstream branch of science, triggering the explosive growth in astrophysics and cosmology that followed. His early contributions to physics include the S matrix, the theory of nuclear rotation (with Edward Teller), the theory of nuclear fission (with Niels Bohr), action-at-a-distance electrodynamics (with Richard Feynman), positrons as backward-in-time electrons, the universal Fermi interaction (with Jayme Tiomno), muonic atoms, and the collective model of the nucleus. His inimitable style of thinking, quirky wit, and love of the bizarre have inspired generations of physicists.

  11. The panacea toolbox of a PhD biomedical student

    PubMed Central

    Skaik, Younis

    2014-01-01

    Doing a PhD (doctor of philosophy) for the sake of contribution to knowledge should give the student an immense enthusiasm through the PhD period. It is the time in one’s life that one spends to “hit the nail on the head” in a specific area and topic of interest. A PhD consists mostly of hard work and tenacity; however, luck and genius might also play a little role. You can pass all PhD phases without having both luck and genius. The PhD student should have pre-PhD and PhD toolboxes, which are “sine quibus non” for getting successfully a PhD degree. In this manuscript, the toolboxes of the PhD student are discussed. PMID:25674150

  12. Intracellular pH in sperm physiology.

    PubMed

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction.

  13. The pH of Mars

    NASA Technical Reports Server (NTRS)

    Plumb, R. C.; Bishop, J. L.; Edwards, J. O.

    1993-01-01

    The Viking labeled release (LR) experiments provided data that can be used to determine the acid-base characteristics of the regolith. Constraints on the acid-base properties and redox potentials of the Martian surface material would provide additional information for determining what reactions are possible and defining formation conditions for the regolith. Calculations devised to determine the pH of Mars must include the amount of soluble acid species or base species present in the LR regolith sample and the solubility product of the carbonate with the limiting solubility. This analysis shows that CaCO3, either as calcite or aragonite, has the correct K(sub sp) to have produced the Viking LR successive injection reabsorption effects. Thus CaCO3 or another MeCO3 with very similar solubility characteristics must have been present on Mars. A small amount of soluble acid, but no more than 4 micro-mol per sample, could also have been present. It is concluded that the pH of the regolith is 7.2 +/- 0.1.

  14. Reactor irradiation effects on the ultimate tensile and the interlaminar shear strength of carbon fibre reinforced epoxies at 77 K

    NASA Astrophysics Data System (ADS)

    Spießberger, S. M.; Humer, K.; Tschegg, E. K.; Weber, H. W.; Gerstenberg, H.

    A carbon fibre reinforced plastics material (CFRP) `TORAYCA T300 3K', which was developed for various applications, including cryogenics, was irradiated at 5 K and 340 K with different reactor spectra up to a fast neutron fluence of 5×10 22 m -2 ( E>0.1 MeV). All investigations in the interlaminar shear mode as well as the tensile tests were made at 77 K, the samples subjected to 5 K irradiation were measured before and after an annealing cycle (of about one day) to room temperature. Fractographic examinations of the tensile samples were used to examine the complicated fracture process. Both the interlaminar shear strength and the ultimate tensile strength show good radiation resistance at the lowest total absorbed dose (˜5×10 6 Gy), but fail at higher dose levels (˜10 8 Gy).

  15. Stress-resultant models for ultimate load design of reinforced concrete frames and multi-scale parameter estimates

    NASA Astrophysics Data System (ADS)

    Pham, B. H.; Brancherie, D.; Davenne, L.; Ibrahimbegovic, A.

    2013-03-01

    In this work, we present a new finite element for (geometrically linear) Timoshenko beam model for ultimate load computation of reinforced concrete frames. The proposed model combines the descriptions of the diffuse plastic failure in the beam-column followed by the creation of plastic hinges due to the failure or collapse of the concrete and of the re-bars. A modified multi-scale analysis is performed in order to identify the parameters for stress-resultant-based macro model, which is used to described the behavior of the Timoshenko beam element. For clarity, we focus upon the micro-scale models using the multi-fiber elements with embedded displacement discontinuities in mode I, which would typically be triggered by bending failure mode. More general case of micro-scale model capable of describing shear failure is described by Ibrahimbegovic et al. (Int J Numer Methods Eng 83(4):452-481, 2010).

  16. Catalytic Decomposition of PH3 on Heated Tungsten Wire Surfaces

    NASA Astrophysics Data System (ADS)

    Umemoto, Hironobu; Nishihara, Yushin; Ishikawa, Takuma; Yamamoto, Shingo

    2012-08-01

    The catalytic decomposition processes of PH3 on heated tungsten surfaces were studied to clarify the mechanisms governing phosphorus doping into silicon substrates. Mass spectrometric measurements show that PH3 can be decomposed by more than 50% over 2000 K. H, P, PH, and PH2 radicals were identified by laser spectroscopic techniques. Absolute density measurements of these radical species, as well as their PH3 flow rate dependence, show that the major products on the catalyst surfaces are P and H atoms, while PH and PH2 are produced in secondary processes in the gas phase. In other words, catalytic decomposition, unlike plasma decomposition processes, can be a clean source of P atoms, which can be the only major dopant precursors. In the presence of an excess amount of H2, the apparent decomposition efficiency is small. This can be explained by rapid cyclic reactions including decomposition, deposition, and etching to reproduce PH3.

  17. Intracellular pH in sperm physiology.

    PubMed

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. PMID:24887564

  18. Intracellular pH in Sperm Physiology

    PubMed Central

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L.; Darszon, Alberto

    2014-01-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca2+ channel; Slo3, a K+ channel; the sperm-specific Na+/H+ exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. PMID:24887564

  19. Ian Douglass Coulter, PhD

    PubMed Central

    Brown, Douglas M

    2004-01-01

    This paper focuses on Dr. Ian Coulter’s accomplishments from the time he became Executive Vice-President of CMCC in 1981, until he ended his presidency with a year’s administrative leave in 1990. Annual planning initiatives, pedagogy, scholarship, conflicts, and the quest for university affiliation are discussed as well as his legacy to the College and the chiropractic profession. The term “adventurous” was first attributed to Coulter by Oswald Hall, PhD, Professor Emeritus, University of Toronto who had worked closely with Coulter in a major investigation of the chiropractic profession from 1976 to 1979. Throughout this article the author tries to capture the spirit of daring, innovation and intellect that permeated Coulter’s presidency, enthralling his advocates and confounding his detractors. PMID:17549218

  20. Steel slag raises pH of greenhouse substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dolomitic lime (DL) is the primary liming agent used for increasing pH in peatmoss-based substrates. Steel slag (SS) is a byproduct of the steel manufacturing industry that has been used to elevate field soil pH. The objective of this research was to determine the pH response of a peatmoss-based g...

  1. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  2. INFLUENCE OF PH AND REDOX CONDITIONS ON COPPER LEACHING

    EPA Science Inventory

    Leaching behavior of metals from a mineral processing waste at varying pH and redox conditions was studies. Effect of combinations of pH and Eh on leaching of copper is described. Leaching of copper was found to be dependent on both pH and Eh. Higher concentrations of Cu were ...

  3. Understanding Non-Traditional PhD Students Habitus--Implications for PhD Programmes

    ERIC Educational Resources Information Center

    Naidoo, Devika

    2015-01-01

    Against the background of vast changes in doctoral education and the emergence of non-traditional doctoral programmes, this paper investigates the habitus of non-traditional PhD students at a South African university. Bourdieu's conceptual tool of habitus informed the study. In-depth and open-ended interviews were conducted with 10 non-traditional…

  4. NASA Graduate Student Researchers Program Ronald E. McNair PhD Program

    NASA Technical Reports Server (NTRS)

    Howard, Sunnie

    1998-01-01

    The NASA Ronald E. McNair PHD Program was funded in September 1995. Implementation began during the spring of 1996. The deferment of the actual program initial semester enabled the program to continue support through the fall semester of 1998. This was accomplished by a no-cost extension from August 15, 1998 through December 31, 1998. There were 12 fellows supported by the program in 1996, 15 fellows in 1997, and 15 fellows 1998. Current program capacity is 15 fellows per funding support. Support for the academic outreach component began in spring 1998. The program was named the "Good Enough" Crew Activity (GECA) in honor of Dr. McNair's philosophy of everyone being good enough to achieve anything they want bad enough. The program currently enrolls 65 students from the third through the eight grades. The program is held 12 Saturdays per semester. The time is 9:00 AM to 12:30 PM each Saturday Morning. Program direction and facilitation is jointly administered with the PHD fellows and the Saturday Academy staff. Dr. John Kelly, REM-PHD Principal Investigator serves in a program oversight and leadership capacity. Ms. Sunnie Howard, The NASA REM-PHD Administrative Coordinator serves in an administrative and logistical capacity. Mr. Aaron Hatch, the NASA-AMES Liaison Officer, serve@'in a consultative and curriculum review capacity. The first recognition activity will be held on December 12, 1998, with the students, parents, faculty, PHD fellows, and other local student support services persons. Program outreach efforts are jointly supported by the NASA REM-PHD Program and the National Space Grant College and Fellowship Program. The Ph.D. program reached its first milestone in May 1998. North Carolina A&T State University graduated the first Ph.D. fellows. The first three Ph.D. Alumni were Ronald E. McNair PHD Program Fellows. It is hoped that this is just the beginning of a highly acclaimed doctoral program. The ultimate program success will be recognized when the

  5. Comparison of Rumen Fluid pH by Continuous Telemetry System and Bench pH Meter in Sheep with Different Ranges of Ruminal pH

    PubMed Central

    Reis, Leonardo F.; Minervino, Antonio H. H.; Araújo, Carolina A. S. C.; Sousa, Rejane S.; Oliveira, Francisco L. C.; Rodrigues, Frederico A. M. L.; Meira-Júnior, Enoch B. S.; Barrêto-Júnior, Raimundo A.; Mori, Clara S.; Ortolani, Enrico L.

    2014-01-01

    We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During this 72-hour period, all animals had electrodes for the continuous measurement of pH. The results were compared using the Bland-Altman analysis of agreement, Pearson coefficients of correlation and determination, and paired analysis of variance with Student's t-test. The measurement methods presented a strong correlation (r = 0.94, P < 0.05) but the rumen pH that was measured continuously using a telemetry system resulted in lower values than the bench pH meter (overall mean of 5.38 and 5.48, resp., P = 0.0001). The telemetry system was able to detect smaller changes in rumen fluid pH and was more accurate in diagnosing both subacute ruminal lactic acidosis and acute ruminal lactic acidosis in sheep. PMID:24967422

  6. Proton Transport and pH Control in Fungi.

    PubMed

    Kane, Patricia M

    2016-01-01

    Despite diverse and changing extracellular environments, fungi maintain a relatively constant cytosolic pH and numerous organelles of distinct lumenal pH. Key players in fungal pH control are V-ATPases and the P-type proton pump Pma1. These two proton pumps act in concert with a large array of other transporters and are highly regulated. The activities of Pma1 and the V-ATPase are coordinated under some conditions, suggesting that pH in the cytosol and organelles is not controlled independently. Genomic studies, particularly in the highly tractable S. cerevisiae, are beginning to provide a systems-level view of pH control, including transcriptional responses to acid or alkaline ambient pH and definition of the full set of regulators required to maintain pH homeostasis. Genetically encoded pH sensors have provided new insights into localized mechanisms of pH control, as well as highlighting the dynamic nature of pH responses to the extracellular environment. Recent studies indicate that cellular pH plays a genuine signaling role that connects nutrient availability and growth rate through a number of mechanisms. Many of the pH control mechanisms found in S. cerevisiae are shared with other fungi, with adaptations for their individual physiological contexts. Fungi deploy certain proton transport and pH control mechanisms not shared with other eukaryotes; these regulators of cellular pH are potential antifungal targets. This review describes current and emerging knowledge proton transport and pH control mechanisms in S. cerevisiae and briefly discusses how these mechanisms vary among fungi.

  7. PhD Students' Work Conditions and Study Environment in University- and Industry-Based PhD Programmes

    ERIC Educational Resources Information Center

    Kolmos, A.; Kofoed, L. B.; Du, X. Y.

    2008-01-01

    During the last 10 years, new models of funding and training PhD students have been established in Denmark in order to integrate industry into the entire PhD education. Several programmes have been conducted where it is possible to co-finance PhD scholarships or to become an employee as an industrial PhD in a company. An important question is what…

  8. pH and the surface tension of water.

    PubMed

    Beattie, James K; Djerdjev, Alex M; Gray-Weale, Angus; Kallay, Nikola; Lützenkirchen, Johannes; Preočanin, Tajana; Selmani, Atiđa

    2014-05-15

    Despite the strong adsorption of hydroxide ions, the surface tension of water is almost independent of pH between pH 1 and 13 when the pH is adjusted by addition of HCl or NaOH. This is consistent with the Gibbs adsorption isotherm which measures the surface excess of all species in the double layer, if hydronium ions and hydroxide ions are adsorbed and sodium and chloride ions are not. The surface tension becomes pH dependent around pH 7 in millimolar NaCl or KCl solutions, for now sodium ions can replace hydronium ions as counterions to the adsorbed hydroxide ions.

  9. Intracellular pH of acid-tolerant ruminal bacteria.

    PubMed Central

    Russell, J B

    1991-01-01

    Acid-tolerant ruminal bacteria (Bacteroides ruminicola B1(4), Selenomonas ruminantium HD4, Streptococcus bovis JB1, Megasphaera elsdenii B159, and strain F) allowed their intracellular pH to decline as a function of extracellular pH and did not generate a large pH gradient across the cell membrane until the extracellular pH was low (less than 5.2). This decline in intracellular pH prevented an accumulation of volatile fatty acid anions inside the cells. PMID:1781695

  10. pH in atomic scale simulations of electrochemical interfaces.

    PubMed

    Rossmeisl, Jan; Chan, Karen; Ahmed, Rizwan; Tripković, Vladimir; Björketun, Mårten E

    2013-07-01

    Electrochemical reaction rates can strongly depend on pH, and there is increasing interest in electrocatalysis in alkaline solution. To date, no method has been devised to address pH in atomic scale simulations. We present a simple method to determine the atomic structure of the metal|solution interface at a given pH and electrode potential. Using Pt(111)|water as an example, we show the effect of pH on the interfacial structure, and discuss its impact on reaction energies and barriers. This method paves the way for ab initio studies of pH effects on the structure and electrocatalytic activity of electrochemical interfaces.

  11. The Role of pH Regulation in Cancer Progression.

    PubMed

    McIntyre, Alan; Harris, Adrian L

    2016-01-01

    Frequently observed phenotypes of tumours include high metabolic activity, hypoxia and poor perfusion; these act to produce an acidic microenvironment. Cellular function depends on pH homoeostasis, and thus, tumours become dependent on pH regulatory mechanisms. Many of the proteins involved in pH regulation are highly expressed in tumours, and their expression is often of prognostic significance. The more acidic tumour microenvironment also has important implications with regard to chemotherapeutic and radiotherapeutic interventions. In addition, we review pH-sensing mechanisms, the role of pH regulation in tumour phenotype and the use of pH regulatory mechanisms as therapeutic targets. PMID:27557536

  12. Time course of pH change in plant epidermis using microscopic pH imaging system

    NASA Astrophysics Data System (ADS)

    Dan, Risako; Shimizu, Megumi; Kazama, Haruko; Sakaue, Hirotaka

    2010-11-01

    We established a microscopic pH imaging system to track the time course of pH change in plant epidermis in vivo. In the previous research, we have found out that anthocyanin containing cells have higher pH. However, it was not clear whether the anthocyanin increased the pH or anthocyanin was synthesized result from the higher pH. Therefore, we further investigated the relationship between anthocyanin and pH change. To track the time course of pH change in plant epidermis, we established a system using luminescent imaging technique. We used HPTS (8-Hydroxypyrene-1,3,6-Trisulfonate) as pH indicator and applied excitation ratio imaging method. Luminescent image was converted to a pH distribution by obtained in vitro calibration using known pH solution. Cellular level observation was enabled by merging microscopic color picture of the same region to the pH change image. The established system was applied to epidermal cells of red-tip leaf lettuce, Lactuca Sativa L. and the time course was tracked in the growth process. We would discuss about the relationship between anthocyanin and pH change in plant epidermis.

  13. Management of Ultimate Risk of Nuclear Power Plants by Source Terms - Lessons Learned from the Chernobyl Accident

    SciTech Connect

    Genn Saji

    2006-07-01

    The term 'ultimate risk' is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the event of a hypothetical and severe accident situation. The author would like to point out that current source terms which are based on the information from the Windscale accident (1957) through TID-14844 are very outdated and do not incorporate lessons learned from either the Three Miles Island (TMI, 1979) nor Chernobyl accident (1986), two of the most severe accidents ever experienced. As a result of the observations of benign radionuclides released at TMI, the technical community in the US felt that a more realistic evaluation of severe reactor accident source terms was necessary. In this background, the 'source term research project' was organized in 1984 to respond to these challenges. Unfortunately, soon after the time of the final report from this project was released, the Chernobyl accident occurred. Due to the enormous consequences induced by then accident, the one time optimistic perspectives in establishing a more realistic source term were completely shattered. The Chernobyl accident, with its human death toll and dispersion of a large part of the fission fragments inventories into the environment, created a significant degradation in the public's acceptance of nuclear energy throughout the world. In spite of this, nuclear communities have been prudent in responding to the public's anxiety towards the ultimate safety of nuclear plants, since there still remained many unknown points revolving around the mechanism of the Chernobyl accident. In order to resolve some of these mysteries, the author has performed a scoping study of the dispersion and deposition

  14. Ultimate detectability of volatile organic compounds: how much further can we reduce their ambient air sample volumes for analysis?

    PubMed

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2012-10-01

    To understand the ultimately lowest detection range of volatile organic compounds (VOCs) in air, application of a high sensitivity analytical system was investigated by coupling thermal desorption (TD) technique with gas chromatography (GC) and time-of-flight (TOF) mass spectrometry (MS). The performance of the TD-GC/TOF MS system was evaluated using liquid standards of 19 target VOCs prepared in the range of 35 pg to 2.79 ng per μL. Studies were carried out using both total ion chromatogram (TIC) and extracted ion chromatogram (EIC) mode. EIC mode was used for calibration to reduce background and to improve signal-to-noise. The detectability of 19 target VOCs, if assessed in terms of method detection limit (MDL, per US EPA definition) and limit of detection (LOD), averaged 5.90 pg and 0.122 pg, respectively, with the mean coefficient of correlation (R(2)) of 0.9975. The minimum quantifiable mass of target analytes, when determined using real air samples by the TD-GC/TOF MS, is highly comparable to the detection limits determined experimentally by standard. In fact, volumes for the actual detection of the major aromatic VOCs like benzene, toluene, and xylene (BTX) in ambient air samples were as low as 1.0 mL in the 0.11-2.25 ppb range. It was thus possible to demonstrate that most target compounds including those in low abundance could be reliably quantified at concentrations down to 0.1 ppb at sample volumes of less than 10 mL. The unique sensitivity of this advanced analytical system can ultimately lead to a shift in field sampling strategy with smaller air sample volumes facilitating faster, simpler air sampling (e.g., use of gas syringes rather than the relative complexity of pumps or bags/canisters), with greatly reduced risk of analyte breakthrough and minimal interference, e.g., from atmospheric humidity. The improved detection limits offered by this system can also enhance accuracy and measurement precision. PMID:22934885

  15. Effects of shear stirrup details on ultimate capacity and tensile-membrane behavior of reinforced concrete slabs. Final report

    SciTech Connect

    Woodson, S.C.

    1985-08-01

    At the time this study was initiated, civil defense planning in the United States called for the evacuation of nonessential personnel to safe host areas when a nuclear attack is probable, requiring the construction of blasts shelters to protect the keyworkers remaining in the risk areas. The placement of shear stirrups in the one-way reinforced concrete roof slabs of the shelters will contribute significantly to project costs. Ten one-way reinforced concrete slabs were statically and uniformly loaded with water pressure, primarily to investigate the effect of stirrups and stirrup details on the load-response behavior of the slabs. The slabs had clear spans of 24.0 inches, span to effective depth ratios of 12.4, tensile reinforcement of 0.75%, and concrete strengths of approximately 5,000 psi. The test series significantly increased the data base for uniformly loaded one-way slabs. Support rotations between 13.1 and 20.6 degrees were observed. A more ductile behavior was observed in slabs with construction details, implying better concrete confinement due to more confining steel (i.e., closely spaced stirrups, double-leg stirrups, and closely spaced principal reinforcing bars). The parameters investigated did not appear to have a significant effect on ultimate load capacity.

  16. Procedure for calculating estimated ultimate recoveries of Bakken and Three Forks Formations horizontal wells in the Williston Basin

    USGS Publications Warehouse

    Cook, Troy A.

    2013-01-01

    Estimated ultimate recoveries (EURs) are a key component in determining productivity of wells in continuous-type oil and gas reservoirs. EURs form the foundation of a well-performance-based assessment methodology initially developed by the U.S. Geological Survey (USGS; Schmoker, 1999). This methodology was formally reviewed by the American Association of Petroleum Geologists Committee on Resource Evaluation (Curtis and others, 2001). The EUR estimation methodology described in this paper was used in the 2013 USGS assessment of continuous oil resources in the Bakken and Three Forks Formations and incorporates uncertainties that would not normally be included in a basic decline-curve calculation. These uncertainties relate to (1) the mean time before failure of the entire well-production system (excluding economics), (2) the uncertainty of when (and if) a stable hyperbolic-decline profile is revealed in the production data, (3) the particular formation involved, (4) relations between initial production rates and a stable hyperbolic-decline profile, and (5) the final behavior of the decline extrapolation as production becomes more dependent on matrix storage.

  17. Imaging-Genetics in Dyslexia: Connecting risk genetic variants to brain neuroimaging and ultimately to reading impairments

    PubMed Central

    Eicher, John D.; Gruen, Jeffrey R.

    2013-01-01

    Dyslexia is a common pediatric disorder that affects 5-17% of schoolchildren in the United States. It is marked by unexpected difficulties in fluent reading despite adequate intelligence, opportunity, and instruction. Classically, neuropsychologists have studied dyslexia using a variety of neurocognitive batteries to gain insight into the specific deficits and impairments in affected children. Since dyslexia is a complex genetic trait with high heritability, analyses conditioned on performance on these neurocognitive batteries have been used to try to identify associated genes. This has led to some successes in identifying contributing genes, although much of the heritability remains unexplained. Additionally, the lack of relevant human brain tissue for analysis and the challenges of modeling a uniquely human trait in animals are barriers to advancing our knowledge of the underlying pathophysiology. In vivo imaging technologies, however, present new opportunities to examine dyslexia and reading skills in a clearly relevant context in human subjects. Recent investigations have started to integrate these imaging data with genetic data in attempts to gain a more complete and complex understanding of reading processes. In addition to bridging the gap from genetic risk variant to a discernible neuroimaging phenotype and ultimately to the clinical impairments in reading performance, the use of neuroimaging phenotypes will reveal novel risk genes and variants. In this article, we briefly discuss the genetic and imaging investigations and take an in-depth look at the recent imaging-genetics investigations of dyslexia. PMID:23916419

  18. Analysis of the influence of voids and a crack on the ultimate tensile strength of REBCO bulk superconductor

    NASA Astrophysics Data System (ADS)

    Kasaba, K.; Oshida, Y.; Hokari, T.; Katagiri, K.

    2008-09-01

    Since the high Tc rare-earth based bulk superconductor is subjected to the tensile load in radial and circumferential direction by the Lorentz force generated in the magnetization process, the evaluation of the strength by the tensile test is indispensable. Ultimate tensile strength of the bulk superconductor depends on the defects in each sample. Many artificial specimens containing voids were generated for numerical stress calculations. The distribution of the voids diameter in each artificial specimen was based on the observations of Dy123 containing 25 wt% Dy211 (abbreviated as Dy25). Furthermore, the effect of a center crack superposed to the field of the voids on the strength was analytically evaluated. The strength depends on both the size and the location of the voids. The maximum crack length which has eventually no effect on the strength was evaluated. By the evaluation method proposed in this study, it was found that if there had been no void in the Dy25 bulk sample, the tensile strength could have been estimated to be 63 MPa. The voids increase the stress intensity factor at the crack tip. If there is a crack with 0.16 mm or more in the Dy25 superconductor bulk with the porosity 10%, the fracture may not be originated around a void but at a crack tip.

  19. Observation of millimeter-wave oscillations from resonant tunneling diodes and some theoretical considerations of ultimate frequency limits

    NASA Technical Reports Server (NTRS)

    Sollner, T. C. L. G.; Brown, E. R.; Goodhue, W. D.; Le, H. Q.

    1987-01-01

    Recent observations of oscillation frequencies up to 56 GHz in resonant tunneling structures are discussed in relation to calculations by several authors of the ultimate frequency limits of these devices. It is found that calculations relying on the Wentzel-Kramers-Brillouin (WKB) approximation give limits well below the observed oscillation frequencies. Two other techniques for calculating the upper frequency limit were found to give more reasonable results. One method employs the solution of the time-dependent Schroedinger equation obtained by Kundrotas and Dargys (1986); the other uses the energy width of the transmission function for electrons through the double-barrier structure. This last technique is believed to be the most accurate since it is based on general results for the lifetime of any resonant state. It gives frequency limits on the order of 1 THz for two recently fabricated structures. It appears that the primary limitation of the oscillation frequency for double-barrier resonant-tunneling diodes is imposed by intrinsic device circuit parameters and by the transit time of the depletion layer rather than by time delays encountered in the double-barrier region.

  20. Intracellular pH of symbiotic dinoflagellates

    NASA Astrophysics Data System (ADS)

    Gibbin, E. M.; Davy, S. K.

    2013-09-01

    Intracellular pH (pHi) is likely to play a key role in maintaining the functional success of cnidarian-dinoflagellate symbiosis, yet until now the pHi of the symbiotic dinoflagellates (genus Symbiodinium) has never been quantified. Flow cytometry was used in conjunction with the ratiometric fluorescent dye BCECF to monitor changes in pHi over a daily light/dark cycle. The pHi of Symbiodinium type B1 freshly isolated from the model sea anemone Aiptasia pulchella was 7.25 ± 0.01 (mean ± SE) in the light and 7.10 ± 0.02 in the dark. A comparable effect of irradiance was seen across a variety of cultured Symbiodinium genotypes (types A1, B1, E1, E2, F1, and F5) which varied between pHi 7.21-7.39 in the light and 7.06-7.14 in the dark. Of note, there was a significant genotypic difference in pHi, irrespective of irradiance.

  1. Dipstick Spot urine pH does not accurately represent 24 hour urine PH measured by an electrode

    PubMed Central

    Omar, Mohamed; Sarkissian, Carl; Jianbo, Li; Calle, Juan; Monga, Manoj

    2016-01-01

    ABSTRACT Objectives To determine whether spot urine pH measured by dipstick is an accurate representation of 24 hours urine pH measured by an electrode. Materials and Methods We retrospectively reviewed urine pH results of patients who presented to the urology stone clinic. For each patient we recorded the most recent pH result measured by dipstick from a spot urine sample that preceded the result of a 24-hour urine pH measured by the use of a pH electrode. Patients were excluded if there was a change in medications or dietary recommendations or if the two samples were more than 4 months apart. A difference of more than 0.5 pH was considered an inaccurate result. Results A total 600 patients were retrospectively reviewed for the pH results. The mean difference in pH between spot urine value and the 24 hours collection values was 0.52±0.45 pH. Higher pH was associated with lower accuracy (p<0.001). The accuracy of spot urine samples to predict 24-hour pH values of <5.5 was 68.9%, 68.2% for 5.5 to 6.5 and 35% for >6.5. Samples taken more than 75 days apart had only 49% the accuracy of more recent samples (p<0.002). The overall accuracy is lower than 80% (p<0.001). Influence of diurnal variation was not significant (p=0.588). Conclusions Spot urine pH by dipstick is not an accurate method for evaluation of the patients with urolithiasis. Patients with alkaline urine are more prone to error with reliance on spot urine pH. PMID:27286119

  2. In vitro synthesis and purification of PhIP-deoxyguanosine and PhIP-DNA oligomer covalent complexes

    SciTech Connect

    Freeman, J.

    1994-12-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine compound formed when meats are cooked at high temperatures. PhIP damages DNA by forming covalent complexes with DNA carcinogen. In an effort to understand how the binding of PhIP to DNA may cause cancer, it is important to characterize the structures of PhIP-damaged DNA molecules. Our HPLC data support fluorescence and {sup 32}P Post-labeling studies which indicate the formation of several species of 2{prime}deoxyguanosine-(dG) or oligodeoxynucleotide-PhIP adducts. The reaction of PhIP with dG resulted in a reddish precipitate that was likely the major adduct, N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP) adduct, with a more polar adduct fraction remaining in the supernatant. Reversed-phase HPLC analysis of the adducts in the supernatant revealed the existence of species of much shorter retention times than the dG-C8-PhIP adduct, confirming that these species are more polar than dG-C8-PhIP. At least four adducts were formed in the reaction of PhIP with DNA oligomer. HPLC analysis of the PhIP-DNA oligomer supernatant after butanol extractions revealed four unresolved peaks which spectra had maximum wavelengths between 340 and 360 nm. Though adduct peaks were not completely resolved, there was {approximately}3 minutes interval between the DNA oligomer peak and the adduct peaks. Furthermore, fluorescence emission data of the DNA oligomer-PhIP adduct solution show heterogeneous binding. The more polar PhIP adducts were fraction-collected and their structures will be solved by nuclear magnetic resonance or x-ray crystallography.

  3. Variation in hydraulic conductivity with decreasing pH in a biologically-clogged porous medium (Invited)

    NASA Astrophysics Data System (ADS)

    Altman, S. J.; Kirk, M. F.; Santillan, E. U.; McGrath, L. K.

    2013-12-01

    Microbial biomass can clog porous media and ultimately affect both structural and mineral trapping of CO2 in geological carbon storage reservoirs. Whether biomass can remain intact following a sudden decrease in groundwater pH, a geochemical change associated with CO2 injection, is unclear. We examined this question using twelve biologically-active and three control column-reactor experiments. Cell abundance and distribution was monitored using confocal microscopy, plating, and direct counting. Hydraulic conductivity (K) was monitored using pressure sensors. Growth occurred for four days at neutral pH. During that time, K within the clogged portion of the reactors decreased from 0.013 to 0.0006 cm s-1 on average, a 1.47 log reduction. Next, the pH of the inflowing aqueous medium was lowered to pH 4 in six experiments and pH 5.7 in six experiments. As a result, K increased in five of the pH 4 experiments and two of the pH 5.7 experiments. Despite this increase, however, the columns remained largely clogged. Compared to pre-inoculation K values, log reductions averaged 1.13 and 1.44 in pH 4 and pH 5.7 experiments, respectively. Our findings show that biomass can largely remain intact following acidification and continue to reduce K, even when considerable cell stress and death occurs. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. Bridging the Reef gaps: first evidence for corals surviving under low pH conditions

    NASA Astrophysics Data System (ADS)

    Tchernov, D.; Fine, M.

    2007-12-01

    Following two major extinction events, the late Permian and Triassic/Jurassic, there is a long absence of corals from the geological record followed by a recurrence coral fossils. This unusual disappearance and reappearance, referred to commonly as 'reef gaps', was explained as a failure in sampling effort, and/or the movement of these species into geographic 'refugia' that have not been found. Because the phylogeny of recent corals suggests their origin in the pre-Permian-extinction , an alternative explanation for reef gaps hypothesized that corals have a means of alternating between soft bodies and fossilizing forms. This study supports this hypothesis. Thirty coral fragments from 5 coral colonies of the scleractinian Mediterranean corals Oculina patagonica (encrusting) and Madracis pharencis (bulbous) were subjected to pH 7.4-7.6 (in accordance with the pH projected by the IPCC for the year 2300) and 30 fragments to pH 8.0-8.3 (ambient) over a period of 12 months. 100% of the colonies in the experiment and 90% of all polyps survived to the end the experiment. The corals grown in acidified conditions, where skeleton-building conditions were absent, maintained basic life functions as a solitary skeleton-less ecophenotype resembling a sea anemone. On an evolutionary scale, these results provide a possible explanation to coral survival over major extinction events such as the Permian/Triassic and Triassic/Jurassic events. It is important to note that these results only demonstrate that corals can persist as soft bodied ecophoenotypes, but the loss of reef framework has major ramifications to the entire structure and function of coral reef ecosystems, ultimately impacting the services they provide to human society.

  5. Variation in Biofilm Stability with Decreasing pH Affects Porous Medium Hydraulic Properties

    NASA Astrophysics Data System (ADS)

    Kirk, M. F.; Santillan, E. F.; McGrath, L. K.; Altman, S. J.

    2010-12-01

    Changes to microbial communities caused by subsurface CO2 injection may have many consequences, including possible impacts to CO2 transport. We used column experiments to examine how decreasing pH, a geochemical change associated with CO2 injection, will affect biofilm stability and ultimately the hydraulic properties of porous media. Columns consisted of 1 mm2 square capillary tubes filled with 105-150 µm diameter glass beads. Artificial groundwater medium containing 1 mM glucose was pumped through the columns at a rate of 0.01 mL/min (q = 14.4 m/day; Re = 0.03). Columns were inoculated with 3 × 10^8 CFU (avg.) of Pseudomonas fluorescens, a model biofilm former, transformed with a green fluorescent protein. Biomass distribution and transport was examined using scanning laser confocal microscopy and effluent plating. Variation in the bulk hydraulic properties of the columns was measured using manometers. In an initial experiment, biofilm growth was allowed to occur for seven days in medium with pH 7.3. Within this period, cells uniformly coated bead surfaces, effluent cell numbers stabilized at 1 × 10^9 CFU/mL, and hydraulic conductivity (K) decreased 77%. Next, medium with pH 4 was introduced. As a result, biomass within the reactor redistributed from bead surfaces to pores, effluent cell numbers decreased to 3 × 10^5 CFU/mL, and K decreased even further (>94% reduction). This decreased K was maintained until the experiment was terminated, seven days after introducing low pH medium. These results suggest that changes in biomass distribution as a result of decreased pH may initially limit transport of solubility-trapped CO2 following CO2 injection. Experiments in progress and planned will test this result in more detail and over longer periods of time. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office

  6. Continuous fetal tissue pH measurement in labor.

    PubMed

    Young, B K; Noumoff, J; Klein, S A; Katz, M

    1978-11-01

    Fifty-one women in labor had continuous monitoring of fetal scalp tissue pH, fetal heart rate by ECG, and uterine contractions. A miniature pH electrode secured by a double spiral fetal ECG electrode was used for measurement of fetal pH every 15 seconds. The results were correlated with fetal scalp blood pH values obtained simultaneously. Fetal scalp sampling is intermittent, requires repeated scalp incisions, is subject to errors due to air mixing and coagulation of the blood sample, and is uncomfortable for the parturient. Placement of the tissue pH electrode allows continuous data recording with the minimum discomfort to the patient and the least number of fetal scalp incisions. Clinical use of the tissue pH electrode might be a practical alternative to fetal scalp samples, if the data obtained accurately reflect fetal status.

  7. pH measurement of low-conductivity waters

    USGS Publications Warehouse

    Busenberg, Eurybiades; Plummer, L.N.

    1987-01-01

    pH is an important and commonly measured parameter of precipitation and other natural waters. The various sources of errors in pH measurement were analyzed and procedures for improving the accuracy and precision of pH measurements in natural waters with conductivities of < 100 uS/cm at 25 C are suggested. Detailed procedures are given for the preparation of dilute sulfuric acid standards to evaluate the performance of pH electrodes in low conductivity waters. A daily check of the pH of dilute sulfuric acid standards and deionized water saturated with a gas mixture of low carbon dioxide at partial pressure (air) prior to the measurement of the pH of low conductivity waters is suggested. (Author 's abstract)

  8. Cell wall pH and auxin transport velocity

    NASA Technical Reports Server (NTRS)

    Hasenstein, K. H.; Rayle, D.

    1984-01-01

    According to the chemiosmotic polar diffusion hypothesis, auxin pulse velocity and basal secretion should increase with decreasing cell wall pH. Experiments were designed to test this prediction. Avena coleoptile sections were preincubated in either fusicoccin (FC), cycloheximide, pH 4.0, or pH 8.0 buffer and subsequently their polar transport capacities were determined. Relative to controls, FC enhanced auxin (IAA) uptake while CHI and pH 8.0 buffer reduced IAA uptake. Nevertheless, FC reduced IAA pulse velocity while cycloheximide increased velocity. Additional experiments showed that delivery of auxin to receivers is enhanced by increased receiver pH. This phenomenon was overcome by a pretreatment of the tissue with IAA. Our data suggest that while acidic wall pH values facilitate cellular IAA uptake, they do not enhance pulse velocity or basal secretion. These findings are inconsistent with the chemiosmotic hypothesis for auxin transport.

  9. Photocatalytic generation of hydrogen by core-shell WO3/BiVO4 nanorods with ultimate water splitting efficiency

    PubMed Central

    Pihosh, Yuriy; Turkevych, Ivan; Mawatari, Kazuma; Uemura, Jin; Kazoe, Yutaka; Kosar, Sonya; Makita, Kikuo; Sugaya, Takeyoshi; Matsui, Takuya; Fujita, Daisuke; Tosa, Masahiro; Kondo, Michio; Kitamori, Takehiko

    2015-01-01

    Efficient photocatalytic water splitting requires effective generation, separation and transfer of photo-induced charge carriers that can hardly be achieved simultaneously in a single material. Here we show that the effectiveness of each process can be separately maximized in a nanostructured heterojunction with extremely thin absorber layer. We demonstrate this concept on WO3/BiVO4+CoPi core-shell nanostructured photoanode that achieves near theoretical water splitting efficiency. BiVO4 is characterized by a high recombination rate of photogenerated carriers that have much shorter diffusion length than the thickness required for sufficient light absorption. This issue can be resolved by the combination of BiVO4 with more conductive WO3 nanorods in a form of core-shell heterojunction, where the BiVO4 absorber layer is thinner than the carrier diffusion length while it’s optical thickness is reestablished by light trapping in high aspect ratio nanostructures. Our photoanode demonstrates ultimate water splitting photocurrent of 6.72 mA cm−2 under 1 sun illumination at 1.23 VRHE that corresponds to ~90% of the theoretically possible value for BiVO4. We also demonstrate a self-biased operation of the photoanode in tandem with a double-junction GaAs/InGaAsP photovoltaic cell with stable water splitting photocurrent of 6.56 mA cm−2 that corresponds to the solar to hydrogen generation efficiency of 8.1%. PMID:26053164

  10. Computer model of unstirred layer and intracellular pH changes. Determinants of unstirred layer pH.

    PubMed

    Marrannes, Roger

    2013-06-01

    Transmembrane acid-base fluxes affect the intracellular pH and unstirred layer pH around a superfused biological preparation. In this paper the factors influencing the unstirred layer pH and its gradient are studied. An analytical expression of the unstirred layer pH gradient in steady state is derived as a function of simultaneous transmembrane fluxes of (weak) acids and bases with the dehydration reaction of carbonic acid in equilibrium. Also a multicompartment computer model is described consisting of the extracellular bulk compartment, different unstirred layer compartments and the intracellular compartment. With this model also transient changes and the influence of carbonic anhydrase (CA) can be studied. The analytical expression and simulations with the multicompartment model demonstrate that in steady state the unstirred layer pH and its gradient are influenced by the size and type of transmembrane flux of acids and bases, their dissociation constant and diffusion coefficient, the concentration, diffusion coefficient and type of mobile buffers and the activity and location of CA. Similar principles contribute to the amplitude of the unstirred layer pH transients. According to these models an immobile buffer does not influence the steady-state pH, but reduces the amplitude of pH transients especially when these are fast. The unstirred layer pH provides useful information about transmembrane acid-base fluxes. This paper gives more insight how the unstirred layer pH and its transients can be interpreted. Methodological issues are discussed. PMID:23860924

  11. Computer model of unstirred layer and intracellular pH changes. Determinants of unstirred layer pH.

    PubMed

    Marrannes, Roger

    2013-06-01

    Transmembrane acid-base fluxes affect the intracellular pH and unstirred layer pH around a superfused biological preparation. In this paper the factors influencing the unstirred layer pH and its gradient are studied. An analytical expression of the unstirred layer pH gradient in steady state is derived as a function of simultaneous transmembrane fluxes of (weak) acids and bases with the dehydration reaction of carbonic acid in equilibrium. Also a multicompartment computer model is described consisting of the extracellular bulk compartment, different unstirred layer compartments and the intracellular compartment. With this model also transient changes and the influence of carbonic anhydrase (CA) can be studied. The analytical expression and simulations with the multicompartment model demonstrate that in steady state the unstirred layer pH and its gradient are influenced by the size and type of transmembrane flux of acids and bases, their dissociation constant and diffusion coefficient, the concentration, diffusion coefficient and type of mobile buffers and the activity and location of CA. Similar principles contribute to the amplitude of the unstirred layer pH transients. According to these models an immobile buffer does not influence the steady-state pH, but reduces the amplitude of pH transients especially when these are fast. The unstirred layer pH provides useful information about transmembrane acid-base fluxes. This paper gives more insight how the unstirred layer pH and its transients can be interpreted. Methodological issues are discussed.

  12. Chapter A6. Section 6.4. pH

    USGS Publications Warehouse

    Wilde, Franceska D.; Busenberg, Eurybiades; Radtke, Dean B.

    2006-01-01

    Measurement of pH is critical to the understanding of the viability and vulnerability of environmental waters and is considered a master variable in determining the aqueous geochemistry of an aqueous system. pH is a measure that represents the hydrogen-ion concentration (activity) of a solution. This section of the National Field Manual (NFM) describes U.S. Geological Survey (USGS) guidance and protocols for measurement of pH in ground and surface waters.

  13. Ratiometric Imaging of Extracellular pH in Dental Biofilms.

    PubMed

    Schlafer, Sebastian; Dige, Irene

    2016-03-09

    The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites are not distributed evenly in dental biofilms. A complex interplay of sorption to and reaction with organic matter in the biofilm reduces the diffusion paths of solutes and creates steep gradients of reactive molecules, including organic acids, across the biofilm. Quantitative fluorescent microscopic methods, such as fluorescence life time imaging or pH ratiometry, can be employed to visualize pH in different microenvironments of dental biofilms. pH ratiometry exploits a pH-dependent shift in the fluorescent emission of pH-sensitive dyes. Calculation of the emission ratio at two different wavelengths allows determining local pH in microscopic images, irrespective of the concentration of the dye. Contrary to microelectrodes the technique allows monitoring both vertical and horizontal pH gradients in real-time without mechanically disturbing the biofilm. However, care must be taken to differentiate accurately between extra- and intracellular compartments of the biofilm. Here, the ratiometric dye, seminaphthorhodafluor-4F 5-(and-6) carboxylic acid (C-SNARF-4) is employed to monitor extracellular pH in in vivo grown dental biofilms of unknown species composition. Upon exposure to glucose the dye is up-concentrated inside all bacterial cells in the biofilms; it is thus used both as a universal bacterial stain and as a marker of extracellular pH. After confocal microscopic image acquisition, the bacterial biomass is removed from all pictures using digital image analysis software, which permits to exclusively calculate extracellular pH. pH ratiometry with the ratiometric dye is well-suited to study extracellular pH in thin biofilms of up to 75 µm thickness, but is limited to the pH range between 4.5 and 7.0.

  14. Field measurement of alkalinity and pH

    USGS Publications Warehouse

    Barnes, Ivan

    1964-01-01

    The behavior of electrometric pH equipment under field conditions departs from the behavior predicted from Nernst's law. The response is a linear function of pH, and hence measured pH values may be corrected to true pH if the instrument is calibrated with two reference solutions for each measurement. Alkalinity titrations may also be made in terms of true pH. Standard methods, such as colorimetric titrations, were rejected as unreliable or too cumbersome for rapid field use. The true pH of the end point of the alkalinity titration as a function of temperature, ionic strength, and total alkalinity has been calculated. Total alkalinity in potable waters is the most important factor influencing the end point pH, which varies from 5.38 (0 ? C, 5 ppm (parts per million) HC0a-) to 4.32 (300 ppm HC0a-,35 ? C), for the ranges of variables considered. With proper precautions, the pH may be determined to =i:0.02 pH and the alkalinity to =i:0.6 ppm HCO3- for many naturally occurring bodies of fresh water.

  15. Molecular aspects of bacterial pH sensing and homeostasis

    PubMed Central

    Krulwich, Terry A.; Sachs, George; Padan, Etana

    2011-01-01

    Diverse mechanisms for pH-sensing and cytoplasmic pH homeostasis enable most bacteria to tolerate or grow at external pH values that are outside the cytoplasmic pH range they must maintain for growth. The most extreme cases are exemplified by the extremophiles that inhabit environments whose pH is below 3 or above 11. Here we describe how recent insights into the structure and function of key molecules and their regulators reveal novel strategies of bacterial pH-homeostasis. These insights may help us better target certain pathogens and better harness the capacities of environmental bacteria. PMID:21464825

  16. Nanosensor aided photoacoustic measurement of pH in vivo

    NASA Astrophysics Data System (ADS)

    Ray, Aniruddha; Yoon, Hyung Ki; Kopelman, Raoul; Wang, Xueding

    2013-03-01

    pH plays a critical role in many aspects of cell and tissues physiology. Lower pH is also a typical characteristic of arthritic joints and tumor tissues. These pH anomalies are also exploited in different drug delivery mechanisms. Here we present, a new method of pH sensing in vivo using spectroscopic photoacoustic measurements facilitated by pH sensitive nanosensors. The nanosensors consist of Seminaphtharhodafluor (SNARF), a pH sensitive dye, encapsulated in a specially designed polyacrylamide hydrogel matrix with a hydrophobic core. The photoacoustic intensity ratio between the excitation wavelengths of 585nm and 565nm increases in the pH range from 6.0 to 8.0 and is used to determine the pH of the local environment. These nanosensors are biodegradable, biocompatible, have a long plasma lifetime and can be targeted to any type of cells or tissues by surface modification using proper targeting moieties. The encapsulation of the dye prevents the interaction of the dye with proteins in plasma and also reduces the dye degradation. The SNARF dye in its free form loses 90% of its absorbance in presence of albumin, a protein found in abundance in plasma, and this has severely limited its adaptation to in vivo environments. In comparison, the SNARF nanosensors lose only 16% of their absorbance in the same environment. We employ these nanosensors to demonstrate the feasibility of pH sensing in vivo through photoacoustic measurements on a rat joint model.

  17. Effect of season on contractile and metabolic properties of desert camel muscle (Camelus dromedarius).

    PubMed

    Abdelhadi, O M A; Babiker, S A; Picard, B; Jurie, C; Jailler, R; Hocquette, J F; Faye, B

    2012-01-01

    Thirty fattened one humped desert camels were used to examine the effect of season on contractile and metabolic properties of Longissimus thoracis (LT) muscle. Ten camels were slaughtered according to seasons of the year (winter, summer and autumn). Season significantly influenced muscle chemical composition, ultimate pH (pHu) and color. Activities of metabolic enzymes were higher during autumn season compared to summer and winter for phosphofructokinase (+64% compared to both seasons) and for isocitrate dehydrogenase (+35% and +145% in autumn vs. summer and winter, respectively). Quantification of muscle myosin heavy chain isoforms by SDS-PAGE electrophoresis showed only presence of type I and type IIa MyHC in camel muscle and indicated high proportion in winter for type I and in autumn for type IIa with respect to other seasons. Several correlations between different MyHC proportions and enzyme activities were reported. These findings indicated that muscle characteristics in camels are influenced by season.

  18. Extracellular pH modulates GABAergic neurotransmission in rat hypothalamus.

    PubMed

    Chen, Z L; Huang, R Q

    2014-06-20

    Changes in extracellular pH have a modulatory effect on GABAA receptor function. It has been reported that pH sensitivity of the GABA receptor is dependent on subunit composition and GABA concentration. Most of previous investigations focused on GABA-evoked currents, which only reflect the postsynaptic receptors. The physiological relevance of pH modulation of GABAergic neurotransmission is not fully elucidated. In the present studies, we examined the influence of extracellular pH on the GABAA receptor-mediated inhibitory neurotransmission in rat hypothalamic neurons. The inhibitory postsynaptic currents (IPSCs), tonic currents, and the GABA-evoked currents were recorded with whole-cell patch techniques on the hypothalamic slices from Sprague-Dawley rats at 15-26 postnatal days. The amplitude and frequency of spontaneous GABA IPSCs were significantly increased while the external pH was changed from 7.3 to 8.4. In the acidic pH (6.4), the spontaneous GABA IPSCs were reduced in amplitude and frequency. The pH induced changes in miniature GABA IPSCs (mIPSCs) similar to that in spontaneous IPSCs. The pH effect on the postsynaptic GABA receptors was assessed with exogenously applied varying concentrations of GABA. The tonic currents and the currents evoked by sub-saturating concentration of GABA ([GABA]) (10 μM) were inhibited by acidic pH and potentiated by alkaline pH. In contrast, the currents evoked by saturating [GABA] (1mM) were not affected by pH changes. We also investigated the influence of pH buffers and buffering capacity on pH sensitivity of GABAA receptors on human recombinant α1β2γ2 GABAA receptors stably expressed in HEK 293 cells. The pH influence on GABAA receptors was similar in HEPES- and MES-buffered media, and not dependent on protonated buffers, suggesting that the observed pH effect on GABA response is a specific consequence of changes in extracellular protons. Our data suggest that the hydrogen ions suppress the GABAergic neurotransmission

  19. Notes on the Measurement of pH Values

    SciTech Connect

    Carranza, R M; Rebak, R B

    2005-05-05

    The original definition of pH is: pH = -log a{sub H}. Where a{sub H} is the (relative) hydrogen ion activity. However, a single ion activity cannot be measured. Activities of individual ionic species are necessarily conventional. The pH number, of course, has in itself little absolute significance. As the negative of the logarithm of a product of a concentration (c or m) and an activity coefficient (y or {gamma}), it acquires its magnitude from the numerical scale adopted for the latter. Experimental pH measurements are nonetheless widely applied to the determination of thermodynamic equilibrium data such as pK values, on the assumption that they represent -log a{sub H} (or paH). The single ion activity coefficient approaches unity as the ionic strength goes to zero, so that activity becomes m or c and paH becomes pmH or pcH. pH is therefore defined operationally in terms of the operation or method used to measure it, that is, by means of a cell called an operational cell. The cell is standardized by solutions of assigned pH value (Reference Value pH Standard, Primary pH Standards and Operational Standards). Such standard reference solutions are buffer solutions whose pH values are assigned from measurements on cells with or without liquid junction. It must be emphasized that the definition of pH scale is quite different from the measurement of pH with glass-reference electrode-pH meter assemblies, where several standards are used in order to take into account possible deficiencies in the electrode and meter performance.

  20. Biomedical PhD education--an international perspective.

    PubMed

    Mulvany, Michael J

    2013-05-01

    The PhD, otherwise known as the doctor of philosophy or Dr. Phil., is an internationally recognized degree, indicating that the PhD graduate has received training in research under supervision. Traditionally, the PhD was the route to an academic career, with most successful PhD graduates receiving tenured university positions. However, over the past 20-30 years, and particularly the past 10 years, the situation has changed dramatically. Governments in many countries have invested massively in PhD education, believing that trained researchers will contribute to the 'knowledge society', and thus increase the competitiveness of their countries in the future economies of the world. Thus, only a small fraction of PhD graduates now end up in academic research. Yet, the PhD remains a research degree, and indeed, institutions have become heavily dependent on PhD students for their research output. The situation has thus created a paradox. On the one hand, it has become essential for institutions to have many PhD students and for the research performed to be of the highest level. On the other hand, the careers of PhD students are not necessarily going to be directly related to the research performed during their PhD studies. The purpose of this article is to explore how this seeming paradox is being addressed in biomedicine and to show that far from being inconsistent that the two aspects are in fact complementary. The article is based on the author's experience as Head of Aarhus Graduate School of Health Sciences 2002-2011 and his work with graduate schools across Europe and internationally through the organization ORPHEUS.

  1. Mapping Soil pH Buffering Capacity of Selected Fields

    NASA Technical Reports Server (NTRS)

    Weaver, A. R.; Kissel, D. E.; Chen, F.; West, L. T.; Adkins, W.; Rickman, D.; Luvall, J. C.

    2003-01-01

    Soil pH buffering capacity, since it varies spatially within crop production fields, may be used to define sampling zones to assess lime requirement, or for modeling changes in soil pH when acid forming fertilizers or manures are added to a field. Our objective was to develop a procedure to map this soil property. One hundred thirty six soil samples (0 to 15 cm depth) from three Georgia Coastal Plain fields were titrated with calcium hydroxide to characterize differences in pH buffering capacity of the soils. Since the relationship between soil pH and added calcium hydroxide was approximately linear for all samples up to pH 6.5, the slope values of these linear relationships for all soils were regressed on the organic C and clay contents of the 136 soil samples using multiple linear regression. The equation that fit the data best was b (slope of pH vs. lime added) = 0.00029 - 0.00003 * % clay + 0.00135 * % O/C, r(exp 2) = 0.68. This equation was applied within geographic information system (GIS) software to create maps of soil pH buffering capacity for the three fields. When the mapped values of the pH buffering capacity were compared with measured values for a total of 18 locations in the three fields, there was good general agreement. A regression of directly measured pH buffering capacities on mapped pH buffering capacities at the field locations for these samples gave an r(exp 2) of 0.88 with a slope of 1.04 for a group of soils that varied approximately tenfold in their pH buffering capacities.

  2. The Semen pH Affects Sperm Motility and Capacitation

    PubMed Central

    Hong, Zhiwei; Xie, Min; Chen, Shengrong; Yao, Bing

    2015-01-01

    As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progressive motility (PR), hypo-osmotic swelling (HOS) rate, and sperm penetration. Our results showed that these parameters were similar in pH 7.2 and 8.2 sperm nutrition solutions, but decreased in pH 5.2 and 6.2 solutions. The HOS rate exhibited positive correlation with the sperm total motility and PR. In addition, the sperm Na+/K+-ATPase activity at different pHs was measured, and the enzyme activity was significantly lower in pH 5.2 and 6.2 media, comparing with that in pH 8.2 and pH 7.2 solutions. Using flow cytometry (FCM) and laser confocal scanning microscopy (LCSM) analysis, the intracellular Ca2+ concentrations of sperm cultured in sperm capacitation solution at pH 5.2, 6.2, 7.2 and 8.2 were determined. Compared with that at pH 7.2, the mean fluorescence intensity of sperm in pH 5.2 and 6.2 media decreased significantly, while that of pH 8.2 group showed no difference. Our results suggested that the declined Na+/K+-ATPase activity at acidic pHs result in decreased sperm movement and capacitation, which could be one of the mechanisms of male infertility. PMID:26173069

  3. The Semen pH Affects Sperm Motility and Capacitation.

    PubMed

    Zhou, Ji; Chen, Li; Li, Jie; Li, Hongjun; Hong, Zhiwei; Xie, Min; Chen, Shengrong; Yao, Bing

    2015-01-01

    As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progressive motility (PR), hypo-osmotic swelling (HOS) rate, and sperm penetration. Our results showed that these parameters were similar in pH 7.2 and 8.2 sperm nutrition solutions, but decreased in pH 5.2 and 6.2 solutions. The HOS rate exhibited positive correlation with the sperm total motility and PR. In addition, the sperm Na(+)/K(+)-ATPase activity at different pHs was measured, and the enzyme activity was significantly lower in pH 5.2 and 6.2 media, comparing with that in pH 8.2 and pH 7.2 solutions. Using flow cytometry (FCM) and laser confocal scanning microscopy (LCSM) analysis, the intracellular Ca2(+ )concentrations of sperm cultured in sperm capacitation solution at pH 5.2, 6.2, 7.2 and 8.2 were determined. Compared with that at pH 7.2, the mean fluorescence intensity of sperm in pH 5.2 and 6.2 media decreased significantly, while that of pH 8.2 group showed no difference. Our results suggested that the declined Na(+)/K(+)-ATPase activity at acidic pHs result in decreased sperm movement and capacitation, which could be one of the mechanisms of male infertility.

  4. pH induced contrast in viscoelasticity imaging of biopolymers

    PubMed Central

    Yapp, R D; Insana, M F

    2009-01-01

    Understanding contrast mechanisms and identifying discriminating features is at the heart of diagnostic imaging development. This report focuses on how pH influences the viscoelastic properties of biopolymers to better understand the effects of extracellular pH on breast tumour elasticity imaging. Extracellular pH is known to decrease as much as 1 pH unit in breast tumours, thus creating a dangerous environment that increases cellular mutatation rates and therapeutic resistance. We used a gelatin hydrogel phantom to isolate the effects of pH on a polymer network with similarities to the extracellular matrix in breast stroma. Using compressive unconfined creep and stress relaxation measurements, we systematically measured the viscoelastic features sensitive to pH by way of time domain models and complex modulus analysis. These results are used to determine the sensitivity of quasi-static ultrasonic elasticity imaging to pH. We found a strong elastic response of the polymer network to pH, such that the matrix stiffness decreases as pH was reduced, however the viscous response of the medium to pH was negligible. While physiological features of breast stroma such as proteoglycans and vascular networks are not included in our hydrogel model, observations in this study provide insight into viscoelastic features specific to pH changes in the collagenous stromal network. These observations suggest that the large contrast common in breast tumours with desmoplasia may be reduced under acidic conditions, and that viscoelastic features are unlikely to improve discriminability. PMID:19174599

  5. Occurrence of the antidiabetic drug Metformin and its ultimate transformation product Guanylurea in several compartments of the aquatic cycle.

    PubMed

    Trautwein, Christoph; Berset, Jean-Daniel; Wolschke, Hendrik; Kümmerer, Klaus

    2014-09-01

    In 2030, the World Health Organization estimates that more than 350 million people will be diagnosed with diabetes. Consequently, Metformin - the biguanide drug of choice orally administered for diabetes type II - is anticipated to see a spike in production. Unlike many pharmaceutical drugs, Metformin (Met) is not metabolized by humans but passes through the body unchanged. Entering aquatic compartments, such as in sewage, it can be bacterially transformed to the ultimate transformation product Guanylurea (Gua). Sampling over one week (n=5) from a Southern German sewage treatment plant revealed very high average (AV) concentrations in influent (AVMet=111,800ng/L, AVGua=1300ng/L) and effluent samples (AVMet=4800ng/L, AVGua=44,000ng/L). To provide a more complete picture of the distribution and potential persistence of these compounds in the German water cycle, a new, efficient and highly sensitive liquid chromatography mass spectrometric method with direct injection was used for the measurement of Metformin and Guanylurea in drinking, surface, sewage and seawater. Limits of quantification (LOQ) ranging from 2-10ng/L allowed the detection of Metformin and Guanylurea in different locations such as: Lake Constance (n=11: AVMet=102ng/L, AVGua=16ng/L), river Elbe (n=12: AVMet=472ng/L, AVGua=9ng/L), river Weser (n=6: AVMet=349ng/L, AVGua=137ng/L) and for the first time in marine North Sea water (n=14: AVMet=13ng/L, AVGua=11ng/L). Based on daily water discharges, Metformin loads of 15.2kg/d (Elbe) and 6.4kg/d (Weser) into the North Sea were calculated. Lake Constance is used to abstract potable water which is further purified to be used as drinking water. A first screening of two tap water samples contained 2ng/L and 61ng/L of Metformin, respectively. The results of this study suggest that Metformin and Guanylurea could be distributed over a large fraction of the world's potable water sources and oceans. With no natural degradation processes, these compounds can be easily

  6. The Three-mm Ultimate Mopra Milky Way Survey (ThrUMMS): A New View of the Molecular Milky Way

    NASA Astrophysics Data System (ADS)

    Barnes, Peter; Muller, Erik; Nguyen Luong, Quang; Nguyen, Hans

    2015-08-01

    We describe a new mm-wave molecular-line mapping survey of the southern Galactic Plane, and its first data releases and science results. The Three-mm Ultimate Mopra Milky Way Survey (ThrUMMS) maps a 60°×2° sector of our Galaxy’s fourth quadrant, using a combination of fast mapping techniques with the Mopra radio telescope, simultaneously in the J=1→0 lines of 12CO, 13CO, C18O, and CN near 112 GHz at ˜arcminute and 0.3 km s-1 resolution, with 1.2 K/chan sensitivity for 12CO and 0.6 K/chan for the other transitions. The calibrated data cubes from these observations are made available to the community after processing through our pipeline. Here, we describe the motivation for ThrUMMS, the development of new observing techniques for Mopra, and how these techniques were optimised to the objectives of the survey. We showcase some sample data products and describe the first science results, on global variations in the iso-CO line ratios and on a detailed multiwavelength study of the GMCs near l=333°. The line ratios vary dramatically across the Galactic Plane, indicating a very wide range of optical depth and excitation conditions, from warm and translucent to cold and opaque. The population of cold clouds in particular have optical depths for 12CO easily exceeding 100 in some locations, and suggests that the fraction of the molecular mass in the Galactic disk that is in the coldest gas may be substantially underestimated. We compute robust column densities from the global data and derive a new conversion law from CO to molecular mass, indicating that global relationships in disk galaxies that depend on the CO→H2 mass conversion, such as star formation laws, may need to be recalibrated. Near l=333°, we have compared ThrUMMS data to HI, cm-continuum, and several Herschel and Spitzer bands to derive the overall mass and star formation properties of two complexes along the line of sight, in the Scutum-Centaurus and Norma arms. The RCW106 complex in particular is

  7. Proximate versus ultimate limiting nutrients in the Mississippi River Plume and Implications for Hypoxia Reductions through Nutrient Management

    NASA Astrophysics Data System (ADS)

    Fennel, Katja; Laurent, Arnaud

    2016-04-01

    A large hypoxic area (15,000 km2 on average) forms every summer over the Texas-Louisiana shelf in the northern Gulf of Mexico due to decay of organic matter that is primarily derived from nutrient inputs from the Mississippi/Atchafalaya River System. Efforts are underway to reduce the extent of hypoxic conditions through nutrient management in the watershed; for example, an interagency Hypoxia Task Force is developing Action Plans with input from various stakeholders that set out targets for hypoxia reduction. An open question is how far nutrient loads would have to be decreased in order to produce the desired reductions in hypoxia and when these would be measurable given significant natural variability. We have simulated a large number of multi-year nutrient load reduction scenarios with a regional biogeochemical model for the region. The model is based on the Regional Ocean Modeling System (ROMS), explicitly includes nitrogen (N) and phosphorus (P) species as inorganic nutrients, and has been shown to realistically reproduce the key processes responsible for hypoxia generation. We have quantified the effects of differential reductions in river N and P loads on hypoxic extent. An assessment of the effects of N versus P reductions is important because, thus far, nutrient management efforts have focused on N, yet P is known to limit primary production in spring and early summer. A debate is ongoing as to whether targets for P reductions should be set and whether nutrient reduction efforts should focus solely on P, which results primarily from urban and industrial point sources and is uncoupled from agricultural fertilizer application. Our results strongly indicate that N is the 'ultimate' limiting nutrient to primary production determining the areal extent and duration of hypoxic conditions in a cumulative sense, while P is temporarily limiting in spring. Although reductions in river P load would decrease hypoxic extent in early summer, they would have a much

  8. Intracellular pH regulation in chicken enterocytes: the importance of extracellular pH.

    PubMed

    Peral, M J; Calonge, M L; Ilundáin, A A

    1995-11-01

    The present work reports the effect of pHo on pHi and Na(+)-H+ exchanger activity. Intracellular pH tended to follow pHo, but the proton distribution across the cell membrane is not at electrochemical equilibrium. Removal of external Na+ acidified the cells by both reversing the direction of the Na(+)-H+ exchanger and hyperpolarizing the cell membrane potential. The relationship between pHo and the rate of Na(+)-dependent proton efflux following an acid load suggests that external protons interact with the Na(+)-H+ exchanger at a single site with an apparent pK (-log of the dissociation constant) of 7.22. The results demonstrate that maintenance of pHo in the physiological range is essential for maintenance of normal cell pH and that the activity of the Na(+)-H+ exchanger involved in pHi regulation is affected by external protons. The results also suggest that, at least at low pHo, some intracellular mechanism is involved in pHi regulation. PMID:8962700

  9. Consideration of Factors Affecting Strip Effluent PH and Sodium Content

    SciTech Connect

    Peters, T.

    2015-07-29

    A number of factors were investigated to determine possible reasons for why the Strip Effluent (SE) can sometimes have higher than expected pH values and/or sodium content, both of which have prescribed limits. All of the factors likely have some impact on the pH values and Na content.

  10. The Early Development of Electronic pH Meters

    ERIC Educational Resources Information Center

    Hines, Wallis G.; de Levie, Robert

    2010-01-01

    A 19-year-old undergraduate at the University of Chicago, Kenneth Goode, in 1921 came up with the idea of an electronic pH meter, worked out some of its initial problems, and set in motion an international scientific effort that culminated in the current, wide availability of electronic pH meters. Except for the replacement of vacuum tubes by…

  11. The Importance of Having a Ph.D., Career Advice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A presentation on the importance of having a PhD to motivate Initiative to Maximize Student Diversity Program (IMSD) undergrads towards conducting research, pursuing careers in the biomedical field, applying to grad school, and getting a Ph.D., based upon ARS scientist's experiences as a student, a ...

  12. Microscale pH Titrations Using an Automatic Pipet.

    ERIC Educational Resources Information Center

    Flint, Edward B.; Kortz, Carrie L.; Taylor, Max A.

    2002-01-01

    Presents a microscale pH titration technique that utilizes an automatic pipet. A small aliquot (1-5 mL) of the analyte solution is titrated with repeated additions of titrant, and the pH is determined after each delivery. The equivalence point is determined graphically by either the second derivative method or a Gran plot. The pipet can be…

  13. Jeanne Murphy, PhD, CNM | Division of Cancer Prevention

    Cancer.gov

    Jeanne Murphy, PhD, CNM is a postdoctoral Cancer Prevention Fellow in the Breast and Gynecologic Cancer Research Group in the Division of Cancer Prevention. She comes to BGCRG with a PhD from Johns Hopkins University School of Nursing. She also completed a graduate certificate in Health Disparities and Health Inequality at Johns Hopkins Bloomberg School of Public Health. |

  14. Effect of pH on biological phosphorus uptake.

    PubMed

    Serralta, J; Ferrer, J; Borrás, L; Seco, A

    2006-12-01

    An anaerobic aerobic laboratory scale sequencing batch reactor (SBR) was operated to study the effect of pH on enhanced biological phosphorus removal. Seven steady states were achieved under different operating conditions. In all of them, a slight variation in the pH value was observed during anaerobic phase. However, pH rose significantly during aerobic phase. The increase observed was due to phosphorus uptake and carbon dioxide stripping. When pH was higher than 8.2-8.25 the phosphorus uptake rate clearly decreased. The capability of Activated Sludge Model No. 2d (ASM2d) and Biological Nutrient Removal Model No. 1 (BNRM1) to simulate experimental results was evaluated. Both models successfully characterized the enhanced biological phosphorus removal performance of the SBR. Furthermore, BNRM1 also reproduced the pH variations observed and the decrease in the phosphorus uptake rate. This model includes a switch function in the kinetic expressions to represent the pH inhibition in biological processes. The pH inhibition constants related to polyphosphate storage process were obtained by adjusting model predictions to measured phosphorus concentrations. On the other hand, pH inhibition should be included in ASM2d to accurately simulate experimental phosphorus evolution observed in an A/O SBR.

  15. Research Collaboration and Commercialization: The PhD Candidate Perspective

    ERIC Educational Resources Information Center

    Dooley, Lawrence; Kenny, Breda

    2015-01-01

    This paper explores PhD students' perceptions of their entrepreneurial and commercial capabilities, their attitude towards university supports and the extent to which they engage in external collaboration. The study concentrated on current PhD researchers at one university in Ireland as a unit of analysis and provides encouraging evidence from the…

  16. A PH-INDUCED STRUCTURAL CHANGE IN BROMEGRASS MOSAIC VIRUS.

    PubMed

    INCARDONA, N L; KAESBERG, P

    1964-01-01

    Bromegrass mosaic virus undergoes a reversible decrease in its sedimentation coefficient when the pH is raised above pH 6.7. At pH 6 the sedimentation coefficient is 87 S, at pH 7 it is 79 S. Intrinsic viscosities determined at pH 6 and 7 are 3.64 and 5.5 x 10(-2) dl/gm. Diffusion coefficients are 1.56 x 10(-7) cm(2)/sec. and 1.44 x 10(-7) cm(2)/sec., respectively. Radii of gyration, measured by x-ray scattering, are 106 and 128 A. However, appropriate combination of sedimentation, diffusion, and viscosity coefficients at pH 6 and 7 yield the same molecular weight. Also, the zero-angle value of x-ray-scattered intensity, which is a function of molecular weight, is the same at the two pH's. These results suggest that bromegrass mosaic virus particles undergo a pH-induced change in structure. This change causes, among other things, an increase in the susceptibility of the particles to degradation by pancreatic ribonuclease. The shape of the titration curve between pH 6.3 and 6.9 is anomalous.

  17. Tracking the PhD Students' Daily Computer Use

    ERIC Educational Resources Information Center

    Sim, Kwong Nui; van der Meer, Jacques

    2015-01-01

    This study investigated PhD students' computer activities in their daily research practice. Software that tracks computer usage (Manic Time) was installed on the computers of nine PhD students, who were at their early, mid and final stage in doing their doctoral research in four different discipline areas (Commerce, Humanities, Health Sciences and…

  18. Photoreversible changes in pH of pea phytochrome solutions

    SciTech Connect

    Tokutomi, S.; Yamamoto, K.T.; Miyoshi, Y.; Furuya, M.

    1982-02-01

    Phytochrome is a chromoprotein that serves as the photoreceptor for a variety of photomorphogenic responses in plants. Phytochrome was isolated from etiolated pea seedlings. Photoinduced pH changes of an unbuffered solution of the phytochrome were monitored with a semimicrocombination pH electrode at pH 6.5. Red-light irradiation increased the pH of the medium. This alkalinization was reversed by a subsequent far-red-light irradiation. The magnitude and direction of the red-light-induced pH changes was dependent on the pH of the photocrome solution, and the maximum alkalinization was observed at pH 6.0, where the number of protons taken up per phytochrome monomer was 0.18. These results suggest that phytochrome is a multifunctional protein composed of a chromophoric domain and a hydrophobic domain. It is probable that the hydrophobic domain is responsible for the photoinduced change of hydrophobicity of phytochrome and that the ionizable groups responsible for the photoinduced pH changes are localized in the chromophoric domain. (JMT)

  19. pH sensitivity of epidermal growth factor receptor complexes.

    PubMed

    Nunez, M; Mayo, K H; Starbuck, C; Lauffenburger, D

    1993-03-01

    The association/dissociation binding kinetics of 125I-labeled mouse epidermal growth factor (EGF) to receptors on human fibroblast cells in monolayer culture have been measured at 4 degrees C as a function of extracellular pH from pH 5-9. At pH 8, steady-state total binding is maximal. As pH is lowered to 6.5, total binding monotonically decreases dramatically. It changes further only slightly between pH 6.5 and 5 to about 20% of the maximum binding value. Scatchard binding plots at pH 7.5 and above show the commonly observed concave-upward, non-linear curve; as pH is lowered, this plot becomes much more linear, indicating that the "high affinity" bound receptor population is greatly diminished. Application of our ternary complex binding model [Mayo et al., J Biol Chem 264:17838-17844, 1989], which hypothesizes complexation of the EGF-bound receptor with a cell surface interaction molecule, indicates that pH may have some direct effects on ternary complex formation, but the major effect is on EGF-receptor dissociation. PMID:8501133

  20. Predicting Computer Science Ph.D. Completion: A Case Study

    ERIC Educational Resources Information Center

    Cox, G. W.; Hughes, W. E., Jr.; Etzkorn, L. H.; Weisskopf, M. E.

    2009-01-01

    This paper presents the results of an analysis of indicators that can be used to predict whether a student will succeed in a Computer Science Ph.D. program. The analysis was conducted by studying the records of 75 students who have been in the Computer Science Ph.D. program of the University of Alabama in Huntsville. Seventy-seven variables were…

  1. Can Community Colleges Survive the PhD Glut?

    ERIC Educational Resources Information Center

    Taylor, Anita

    The impact of the current employment situation on hiring faculty for community college teaching is examined. It is concluded that prospects for improving the quality of learning in community colleges are not particularly enhanced by the apparently growing surplus of new PhDs in our field. On the contrary, it is suggested that hiring PhDs for…

  2. Rethinking PhD Learning Incorporating Communities of Practice

    ERIC Educational Resources Information Center

    Shacham, Miri; Od-Cohen, Yehudit

    2009-01-01

    This paper grows from research which focuses on the learning characteristics of PhD students, incorporating communities of practice both during their studies and beyond completion of their PhD, and drawing on theories of adult learning and lifelong learning. It shows how professional discourse enhances academic discourse through student engagement…

  3. PhDs in Australia, from the Beginning

    ERIC Educational Resources Information Center

    Dobson, Ian R.

    2012-01-01

    The Australian PhD is a relatively recent phenomenon, the first three being awarded in 1948. Before that, most Australian scholars typically went to Britain (predominantly) or the USA to undertake their doctoral studies. The aim of this research note is to provide a brief statistical history of the Australian PhD, noting changes over time between…

  4. The PhD Viva: A Space for Academic Development

    ERIC Educational Resources Information Center

    Share, Michelle

    2016-01-01

    This study examined the viva experiences of 87 social science PhD graduates from three Irish higher education institutions through a questionnaire that assessed outcome, preparation, conduct and post-viva. The majority were awarded their PhD with minor corrections, considered their viva as a summative assessment, and emphasised its purpose as…

  5. The Undergraduate Origins of PhD Economists Revisited

    ERIC Educational Resources Information Center

    Stock, Wendy A.; Siegfried, John J.

    2015-01-01

    The authors update prior analyses of the undergraduate origins of individuals who earn a PhD in economics in the United States. They include the list of the top institutions worldwide graduating the largest number of undergraduates who subsequently earn an economics PhD from a U.S. university and lists of American institutions with the largest…

  6. Variation of ocean pH in the Indonesia waters

    NASA Astrophysics Data System (ADS)

    Putri, Mutiara Rachmat; Setiawan, Agus; Safitri, Mediana

    2015-09-01

    The variation of ocean acidity (pH) in the Indonesia waters is strongly influenced by monsoon. Since the climate change tends to potentially change monsoonal variation over the Indonesian region, it will give also implication to the ocean pH variation. Moreover, changes of ocean pH will give effects to the marine lifes and their environment. In order to investigate this issue, we tried to calculate monthly variation of sea surface pH in the Indonesia waters based on monthly average temperature and salinity over past 18 years data. Temperature and salinity data used in this study were taken from the hydrodynamic model of Hamburg Shelf Ocean Model (HAMSOM), while alkalinity and dissolved inorganic carbon (DIC) were from World Ocean Atlas 2009 (WOA 2009). Algorithm from Ocean Carbon Model Intercomparison Project-version.3 (OCMIP-3) was used to calculate the pH. The estimation results indicate that pH variation in the Indonesia waters changes insignificantly over 18 years. El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) contribute to physical changes of seawater, but did not affect the pH significantly. The average pH of seawater is higher during northwest monsoon than during southeast monsoon.

  7. Earth & Space Science PhDs, Class of 2001.

    ERIC Educational Resources Information Center

    Claudy, Nicholas; Henly, Megan; Migdalski, Chet

    This study documents the employment patterns and demographic characteristics of recent PhDs in earth and space science. It summarizes the latest annual survey of recent earth and space science PhDs conducted by the American Geological Institute, the American Geophysical Union, and the Statistical Research Center of the American Institute of…

  8. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stomach pH electrode. 876.1400 Section 876.1400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode....

  9. What if We Made Fewer Ph.D.'s?

    ERIC Educational Resources Information Center

    Cassuto, Leonard

    2012-01-01

    Whenever a discussion opens about nonacademic employment for Ph.D.s, it is not long before someone suggests reducing graduate-school admissions. "The market for full-time scholars has fallen off a cliff lately," this argument goes, "so why not just train fewer of them?" The strategy to reduce the number of Ph.D. students recurs in those…

  10. [Stop the compulsive PhD trajectory for junior doctors].

    PubMed

    Clevers, J C Hans

    2014-01-01

    It has become the rule rather than the exception that junior doctors in training spend 3-4 years on a research project, culminating in a thesis. Without a PhD, clinical career prospects within and outside academia look rather bleak. Here I argue that PhD degrees should be pursued only by the most talented and motivated young clinicians. PMID:24893817

  11. Simple fibre optic spectrophotometric cell for pH determination.

    PubMed

    Besar, S S; Kelly, S W; Greenhalgh, P A

    1989-03-01

    A simple, inexpensive fibre optic spectrophotometric cell has been developed for clinical use. The system may employ one of two indicator reagents for the measurement: phenol red and BDH universal indicator. The spectrophotometer uses two ultrabright LED sources and a PIN diode photodetector. The fibre is of the plastic type with a core diameter of 1.0 mm. Two alternative analytical methods are available: electronic or computer processing. In the case of phenol red the measuring range using computer processing is between 6.0 and 8.0 pH units, with an accuracy of 0.015 pH units. The range for electronic circuit processing is from 6.8 to 8.0 pH units with an accuracy of 0.02 pH units. Using a BDH universal indicator, the range for computer processing is between 5.5 and 8.5 pH units with an accuracy of 0.05 pH units, while with electronic processing the range is between 6.0 and 8.0 pH units with an accuracy of 0.03 pH units. A description of the optoelectronics, an analysis of the indicator reagents and the calibration procedure are presented here, together with some example results. PMID:2704218

  12. pH in atomic scale simulations of electrochemical interfaces.

    PubMed

    Rossmeisl, Jan; Chan, Karen; Ahmed, Rizwan; Tripković, Vladimir; Björketun, Mårten E

    2013-07-01

    Electrochemical reaction rates can strongly depend on pH, and there is increasing interest in electrocatalysis in alkaline solution. To date, no method has been devised to address pH in atomic scale simulations. We present a simple method to determine the atomic structure of the metal|solution interface at a given pH and electrode potential. Using Pt(111)|water as an example, we show the effect of pH on the interfacial structure, and discuss its impact on reaction energies and barriers. This method paves the way for ab initio studies of pH effects on the structure and electrocatalytic activity of electrochemical interfaces. PMID:23703376

  13. Ratiometric Fluorescent pH Probes Based on Glycopolymers.

    PubMed

    Li, Zhiyun; Zhang, Pengshan; Lu, Wei; Peng, Lun; Zhao, Yun; Chen, Gaojian

    2016-09-01

    Effectively detecting pH changes plays a critical role in exploring cellular functions and determining physiological and pathological processes. A novel ratiometric pH probe based on a glycopolymer, armored with properties of serum-stability, tumor-targeting, and pH monitoring, is designed. Random copolymers of 2-(methacrylamido) glucopyranose and fluorescein O-methacrylate are first synthesized by reversible addition fragmentation chain transfer polymerization. Acryloxyethyl thiocarbamoyl rhodamine B is then attached to the polymer chain to prepare ratiometric fluorescent pH probes via a thiol-ene reaction. The synthesized polymeric probes are characterized by NMR, gel permeation chromatography, UV-vis spectroscopy, and transmission electron microscopy, and the fluorescence responses are examined in phosphate buffer at different pHs. The cytotoxicity and confocal imaging experiments of the probes are detected using HeLa cells, demonstrating a low toxicity and superior biocompatibility for detecting pH changes in bioapplications. PMID:27439338

  14. Ratiometric Fluorescent pH Probes Based on Glycopolymers.

    PubMed

    Li, Zhiyun; Zhang, Pengshan; Lu, Wei; Peng, Lun; Zhao, Yun; Chen, Gaojian

    2016-09-01

    Effectively detecting pH changes plays a critical role in exploring cellular functions and determining physiological and pathological processes. A novel ratiometric pH probe based on a glycopolymer, armored with properties of serum-stability, tumor-targeting, and pH monitoring, is designed. Random copolymers of 2-(methacrylamido) glucopyranose and fluorescein O-methacrylate are first synthesized by reversible addition fragmentation chain transfer polymerization. Acryloxyethyl thiocarbamoyl rhodamine B is then attached to the polymer chain to prepare ratiometric fluorescent pH probes via a thiol-ene reaction. The synthesized polymeric probes are characterized by NMR, gel permeation chromatography, UV-vis spectroscopy, and transmission electron microscopy, and the fluorescence responses are examined in phosphate buffer at different pHs. The cytotoxicity and confocal imaging experiments of the probes are detected using HeLa cells, demonstrating a low toxicity and superior biocompatibility for detecting pH changes in bioapplications.

  15. ['Sandwich PhD': considerations for a successful experience abroad].

    PubMed

    Salvetti, Marina de Goes; Bueno, Mariana; Gastaldo, Denise; Kimura, Amélia Fumiko; Pimenta, Cibele Andrucioli de Mattos

    2013-03-01

    International PhD internship, named "Sandwich PhD" in Brazil is an opportunity to improve research abilities, to become known in academic area and to establish and/or increase work opportunities in an international context. In this article, we describe key factors regarding the planning and development of the "Sandwich PhD" as experienced by professors and students involved in the collaboration between the School of Nursing, University of São Paulo and Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Canada. We also present the participation of PhD students' network as an alternative to the "Sandwich PhD". An international experience, when well-planned and developed correctly, promotes students' personal and professional development and favors the internationalization of Brazilian graduate programs and research groups.

  16. Reynolds numbers and the elliptic approximation near the ultimate state of turbulent Rayleigh-Bénard convection

    NASA Astrophysics Data System (ADS)

    He, Xiaozhou; van Gils, Dennis P. M.; Bodenschatz, Eberhard; Ahlers, Guenter

    2015-06-01

    (Grossmann and Lohse 2004 Phys. Fluids 16 4462) for ReV. At {\\text{}}{Ra}={\\text{}}{{Ra}}2*≃ 7× {10}13 the dependence of ReV on Ra changed, and for larger Ra {\\text{}}{{Re}}V˜ {\\text{}}{{Ra}}0.50+/- 0.02, consistent with the prediction for ReU (Grossmann and Lohse 2000 J. Fluid. Mech. 407 27; Grossmann and Lohse Phys. Rev. Lett. 2001 86 3316; Grossmann and Lohse Phys. Rev. E 2002 66 016305; Grossmann and Lohse 2012 Phys. Fluids 24 125103) in the ultimate state of RBC.

  17. Continuous pH monitoring in a perfused bioreactor system using an optical pH sensor

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Antony S.; Vani, Sundeep; Taylor, Thomas D.; Anderson, Melody M.

    2002-01-01

    Monitoring and regulating the pH of the solution in a bioprocess is one of the key steps in the success of bioreactor operation. An in-line optical pH sensor, based on the optical absorption properties of phenol red present in the medium, was developed and tested in this work for use in NASA space bioreactors based on a rotating wall-perfused vessel system supporting a baby hamster kidney (BHK-21) cell culture. The sensor was tested over three 30-day and one 124-day cell runs. The pH sensor initially was calibrated and then used during the entire cell culture interval. The pH reported by the sensor was compared to that measured by a fiber optically coupled Shimadzu spectrophotometer and a blood gas analyzer. The maximum standard error of prediction for all the four cell runs for development pH sensor against BGA was +/-0.06 pH unit and for the fiber optically coupled Shimadzu spectrophotometer against the blood gas analyzer was +/-0.05 pH unit. The pH sensor system performed well without need of recalibration for 124 days. Copyright 2002 Wiley Periodicals, Inc.

  18. Live cell imaging of lysosomal pH changes with pH responsive ratiometric lanthanide probes.

    PubMed

    Smith, David G; McMahon, Brian K; Pal, Robert; Parker, David

    2012-09-01

    Europium and terbium complexes of two structurally related ligands have been evaluated as optical probes to monitor changes in lysosomal pH; calibration using ionophores and fluorescent probes allows monitoring of the time dependence of lysosomal pH change, examining the green/red intensity ratio from internalised Tb-Eu complexes.

  19. Thermal processing of acidified foods with pH 4.1 to pH 4.6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shelf-stable acidified foods with a pH at or below 4.6 must be processed to achieve a 5-log reduction for vegetative bacterial pathogens. Published research does not exist to adequately support the Food and Drug Administration process filings for products with pH 4.1–4.6 or to define critical limits...

  20. The Philadelphia (Ph) chromosome in leukemia. III. Complex Ph translocation plus inversion in chronic myelocytic leukemia.

    PubMed

    Morgan, R; Stebbins, R D; Hecht, F; Sandberg, A A

    1985-01-01

    Remarkable chromosome abnormalities were observed in bone marrow cells from a woman with chronic myelocytic leukemia and atypical tuberculosis due to Mycobacterium avium-intracellulare infection. Four chromosome breaks occurred at bands 1p13, 1q32, 11p15, and 22q11. These breaks resulted in a complex Philadelphia (Ph) translocation between chromosomes #1, #11, and #22 and in an inversion of chromosome #1. Oncogenes on these chromosomes include N-ras and c-sk on chromosome #1, c-H-ras on chromosome #11, and c-sis on chromosome #22. Complex chromosome rearrangements may facilitate multiple oncogene changes, thereby permitting several steps in cancer development to occur simultaneously.

  1. 26 CFR 48.6421-2 - Credits or payments to ultimate purchasers of gasoline used in intercity, local, or school buses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... gasoline used in intercity, local, or school buses. 48.6421-2 Section 48.6421-2 Internal Revenue INTERNAL... Manufacturers Taxes § 48.6421-2 Credits or payments to ultimate purchasers of gasoline used in intercity, local, or school buses. (a) In general. If gasoline is used in an intercity or local bus while engaged...

  2. 26 CFR 48.6421-2 - Credits or payments to ultimate purchasers of gasoline used in intercity, local, or school buses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... gasoline used in intercity, local, or school buses. 48.6421-2 Section 48.6421-2 Internal Revenue INTERNAL... Manufacturers Taxes § 48.6421-2 Credits or payments to ultimate purchasers of gasoline used in intercity, local, or school buses. (a) In general. If gasoline is used in an intercity or local bus while engaged...

  3. 26 CFR 5c.168(f)(8)-9 - Pass-through leases-transfer of only the investment tax credit to a party other than the ultimate...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... investment tax credit to a party other than the ultimate user of the property. 5c.168(f)(8)-9 Section 5c.168(f)(8)-9 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) TEMPORARY INCOME TAX REGULATIONS UNDER THE ECONOMIC RECOVERY TAX ACT OF 1981 §...

  4. "Our Ultimate Competition," a Speech by John Neufeld, and Readers' Responses to Neufeld's "Boys Lie" by Matthew Ellis, Jaime Miller and Liz Ackert.

    ERIC Educational Resources Information Center

    Moore, John Noell, Ed.

    2000-01-01

    Suggests the ultimate competition for writers of contemporary adolescent fiction is life--the world that children inhabit is getting stranger and stranger. Discusses parents' and adolescents' different reactions to the novel "Boys Lie," which addresses the issues of rape and sexual harassment. Presents reactions to the speech and the responses of…

  5. Layer- and Direction-Specific Material Properties, Extreme Extensibility and Ultimate Material Strength of Human Abdominal Aorta and Aneurysm: A Uniaxial Extension Study.

    PubMed

    Teng, Zhongzhao; Feng, Jiaxuan; Zhang, Yongxue; Huang, Yuan; Sutcliffe, Michael P F; Brown, Adam J; Jing, Zaiping; Gillard, Jonathan H; Lu, Qingsheng

    2015-11-01

    Mechanical analysis has the potential to provide complementary information to aneurysm morphology in assessing its vulnerability. Reliable calculations require accurate material properties of individual aneurysmal components. Quantification of extreme extensibility and ultimate material strength of the tissue are important if rupture is to be modelled. Tissue pieces from 11 abdomen aortic aneurysm (AAA) from patients scheduled for elective surgery and from 8 normal aortic artery (NAA) from patients who scheduled for kidney/liver transplant were collected at surgery and banked in liquid nitrogen with the use of Cryoprotectant solution to minimize frozen damage. Prior to testing, specimen were thawed and longitudinal and circumferential tissue strips were cut from each piece and adventitia, media and thrombus if presented were isolated for the material test. The incremental Young's modulus of adventitia of NAA was direction-dependent at low stretch levels, but not the media. Both adventitia and media had a similar extreme extensibility in the circumferential direction, but the adventitia was much stronger. For aneurysmal tissues, no significant differences were found when the incremental moduli of adventitia, media or thrombus in both directions were compared. Adventitia and media from AAA had similar extreme extensibility and ultimate strength in both directions and thrombus was the weakest material. Adventitia and media from AAA were less extensible compared with those of NAA, but the ultimate strength remained similar. The material properties, including extreme extensibility and ultimate strength, of both healthy aortic and aneurysmal tissues were layer-dependent, but not direction-dependent.

  6. Genetic parameters of meat technological quality traits in a grand-parental commercial line of turkey.

    PubMed

    Le Bihan-Duval, Elisabeth; Berri, Cécile; Baéza, Elisabeth; Santé, Véronique; Astruc, Thierry; Rémignon, Hervé; Le Pottier, Gilles; Bentley, James; Beaumont, Catherine; Fernandez, Xavier

    2003-01-01

    Genetic parameters for meat quality traits and their relationships with body weight and breast development were estimated for a total of 420 male turkeys using REML. The birds were slaughtered in a commercial plant and the traits measured included pH at 20 min (pH20) and 24 h post-mortem (pHu) and colour of the breast and thigh meat. The heritabilities of the rate and the extent of the pH fall in the breast muscle were estimated at h2=0.21 +/- 0.04 and h2=0.16 +/- 0.04, respectively. Heritabilities ranging from 0.10 to 0.32 were obtained for the colour indicators in the breast muscle. A marked negative genetic correlation (rg=-0.80 +/- 0.10) was found between pH20 and lightness (L*) of breast meat, both traits corresponding to PSE indicators. The pH20 in the thigh muscle had a moderate heritability (h2=0.20 +/- 0.07) and was partially genetically related to pH20 in the breast muscle (rg=0.45 +/- 0.17). Body weight and breast yield were positively correlated with both initial and ultimate pH and negatively with the lightness of breast meat.

  7. Improved granular activated carbon for the stabilization of wastewater PH

    SciTech Connect

    Farmer, R.W.; Dussert, B.W.; Kovacic, S.L.

    1996-12-31

    Laboratory studies have identified the cause of the pH rise, which occurs during water treatment with activated carbon, as an interaction between the naturally occurring anions and protons in the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. These studies have shown that the anion sorption and resulting pH increase is independent of the raw material used for the activated carbon production, e.g. bituminous or subbituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of the wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface through controlled oxidation rather than the water chemistry or extended preprocessing at the treatment site.

  8. Nanochannel pH gradient electrofocusing of proteins.

    PubMed

    Startsev, Michael A; Inglis, David W; Baker, Mark S; Goldys, Ewa M

    2013-08-01

    We demonstrate matrix-free pH gradient electrofocusing of proteins within an 85 nm deep nanochannel. In contrast to conventional isoelectric focusing where the fluid does not move, this pH gradient method traps protein molecules flowing through a channel by balancing electric forces due to pH-dependent protein charge and viscous drag forces caused by electro-osmosis. The nanoscale depth of the device and the low voltage used limit convection relative to diffusion, thus producing a stable focused band of protein. R-Phycoerythrin (RPE) and Dylight labeled streptavidin (Dyl-Strep) were focused within a nanochannel using applied voltages between 0.4 and 1.6 V. Concentration enhancement factors of over 380 have been achieved within 5 min. Varying the buffer pH (between 2.7 and 7.2) at the boundaries of the nanochannel affected the shape of the focused bands. For RPE, a pH span of 4.5 (pH 2.7 to 7.2) yielded the narrowest peak while a span of 2.4 (pH 2.7 to 5.1) produced a significantly wider peak. Such matrix-free nanofluidic devices with pH gradient electrofocusing may enable on-chip integration of orthogonal separation techniques with mass spectrometry offering labor savings and enhanced performance. PMID:23819922

  9. A ph sensor based on a flexible substrate

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Ding

    pH sensor is an essential component used in many chemical, food, and bio-material industries. Conventional glass electrodes have been used to construct pH sensors, however, have some disadvantages. Glass electrodes are easily affected by alkaline or HF solution, they require a high input impedance pH meter, they often exhibit a sluggish response. In some specific applications, it is also difficult to use glass electrodes for in vivo biomedical or food monitoring applications due to the difficulty of size miniaturization, planarization and polymerization based on current manufacturing technologies. In this work, we have demonstrated a novel flexible pH sensor based on low-cost sol-gel fabrication process of iridium oxide (IrOx) sensing film (IROF). A pair of flexible miniature IrOx/AgCl electrode generated the action potential from the solution by electrochemical mechanism to obtain the pH level of the reagent. The fabrication process including sol-gel, thermal oxidation, and the electro-plating process of the silver chloride (AgCl) reference electrode were reported in the work. The IrOx film was verified and characterized using electron dispersive analysis (EDAX), scanning electron microscope (SEM), and x-ray diffraction (XRD). The flexible pH sensor's performance and characterization have been investigated with different testing parameters such as sensitivity, response time, stability, reversibility, repeatability, selectivity and temperature dependence. The flexible IrOx pH sensors exhibited promising sensing performance with a near-Nernstian response of sensitivity which is between --51.1mV/pH and --51.7mV/pH in different pH levels ranging from 1.5 to 12 at 25°C. Two applications including gastroesophageal reflux disease (GERD) diagnosis and food freshness wireless monitoring using our micro-flexible IrOx pH sensors were demonstrated. For the GERD diagnosing system, we embedded the micro flexible pH sensor on a 1.2cmx3.8cm of the capsule size of wireless sensor

  10. pH in physiological salt solutions: direct measurements.

    PubMed

    Abrahamsen, J; Norrie, B; Andersen, P K; Stokke, D B; Nedergaard, O A

    1990-11-01

    Calculations of pH in modified Krebs solutions by inserting PCO2 and total-CO2 in the Henderson-Hasselbalch (H.-H.) equation are obvious as the equation originally served for this purpose. An exact calculation of the relation between pH and PCO2 is complicated as the concentration of bicarbonate, the dissociation constant and the solubility of CO2 change. Furthermore, the dissociation constant in the H.-H. equation is constant only if activities are used in the equation instead of stoichiometric concentrations. We therefore investigated the influence of different carbon dioxide tensions and bicarbonate concentrations on directly measured pH of organ baths aerated with mass-spectrometric analyzed O2-CO2 gases. For reference precision buffers were used. The measured pH values differed distinctly from calculated pH values in the acidic and alkaline parts of the pH interval investigated (6.57-8.15). Measurements of actual pH with proper calibration standards therefore seem mandatory. PMID:2177306

  11. Influence of the Kingak Shale ultimate shelf margin on frontal structures of the Brooks Range in the National Petroleum Reserve in Alaska

    USGS Publications Warehouse

    Stier, Natalie E.; Connors, Christopher D.; Houseknecht, David W.

    2014-01-01

    The Jurassic–Lower Cretaceous Kingak Shale in the National Petroleum Reserve in Alaska (NPRA) includes several southward-offlapping depositional sequences that culminate in an ultimate shelf margin, which preserves the depositional profile in southern NPRA. The Kingak Shale thins abruptly southward across the ultimate shelf margin and grades into condensed shale, which is intercalated with underlying condensed shale and chert of the Upper Triassic Shublik Formation and overlying condensed shale of the Lower Cretaceous pebble shale unit and the gamma-ray zone (GRZ) of the Hue Shale. This composite of condensed shale forms a thin (≈300-meter) and mechanically weak section between much thicker and mechanically stronger units, including the Sadlerochit and Lisburne Groups below and the sandstone-prone foredeep wedge of the Torok Formation above. Seismic interpretation indicates that the composite condensed section acted as the major detachment during an Early Tertiary phase of deformation in the northern foothills of the Brooks Range and that thrust faults step up northward to the top of the Kingak, or to other surfaces within the Kingak or the overlying Torok. The main structural style is imbricate fault-bend folding, although fault-propagation folding is evident locally, and large-displacement thrust faults incorporate backthrusting to form structural wedges. The Kingak ultimate shelf margin served as a ramp to localize several thrust faults, and the spatial relationship between the ultimate shelf margin and thrust vergence is inferred to have controlled many structures in southern NPRA. For example, the obliqueness of the Carbon Creek anticline relative to other structures in the foothills is the result of northward-verging thrust faults impinging obliquely on the Kingak ultimate shelf margin in southwestern NPRA.

  12. Titratable acidity of beverages influences salivary pH recovery.

    PubMed

    Tenuta, Livia Maria Andaló; Fernández, Constanza Estefany; Brandão, Ana Carolina Siqueira; Cury, Jaime Aparecido

    2015-01-01

    A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH- to reach pH 5.5, respectively). Eight volunteers with a normal salivary flow rate and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

  13. A ph sensor based on a flexible substrate

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Ding

    pH sensor is an essential component used in many chemical, food, and bio-material industries. Conventional glass electrodes have been used to construct pH sensors, however, have some disadvantages. Glass electrodes are easily affected by alkaline or HF solution, they require a high input impedance pH meter, they often exhibit a sluggish response. In some specific applications, it is also difficult to use glass electrodes for in vivo biomedical or food monitoring applications due to the difficulty of size miniaturization, planarization and polymerization based on current manufacturing technologies. In this work, we have demonstrated a novel flexible pH sensor based on low-cost sol-gel fabrication process of iridium oxide (IrOx) sensing film (IROF). A pair of flexible miniature IrOx/AgCl electrode generated the action potential from the solution by electrochemical mechanism to obtain the pH level of the reagent. The fabrication process including sol-gel, thermal oxidation, and the electro-plating process of the silver chloride (AgCl) reference electrode were reported in the work. The IrOx film was verified and characterized using electron dispersive analysis (EDAX), scanning electron microscope (SEM), and x-ray diffraction (XRD). The flexible pH sensor's performance and characterization have been investigated with different testing parameters such as sensitivity, response time, stability, reversibility, repeatability, selectivity and temperature dependence. The flexible IrOx pH sensors exhibited promising sensing performance with a near-Nernstian response of sensitivity which is between --51.1mV/pH and --51.7mV/pH in different pH levels ranging from 1.5 to 12 at 25°C. Two applications including gastroesophageal reflux disease (GERD) diagnosis and food freshness wireless monitoring using our micro-flexible IrOx pH sensors were demonstrated. For the GERD diagnosing system, we embedded the micro flexible pH sensor on a 1.2cmx3.8cm of the capsule size of wireless sensor

  14. Method for producing rapid pH changes

    DOEpatents

    Clark, J.H.; Campillo, A.J.; Shapiro, S.L.; Winn, K.R.

    A method of initiating a rapid pH change in a solution comprises irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

  15. Method for producing rapid pH changes

    DOEpatents

    Clark, John H.; Campillo, Anthony J.; Shapiro, Stanley L.; Winn, Kenneth R.

    1981-01-01

    A method of initiating a rapid pH change in a solution by irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

  16. Label-Free Carbon-Dots-Based Ratiometric Fluorescence pH Nanoprobes for Intracellular pH Sensing.

    PubMed

    Shangguan, Jingfang; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Xu, Fengzhou; Liu, Jinquan; Tang, Jinlu; Yang, Xue; Huang, Jin

    2016-08-01

    Measuring pH in living cells is of great importance for better understanding cellular functions as well as providing pivotal assistance for early diagnosis of diseases. In this work, we report the first use of a novel kind of label-free carbon dots for intracellular ratiometric fluorescence pH sensing. By simple one-pot hydrothermal treatment of citric acid and basic fuchsin, the carbon dots showing dual emission bands at 475 and 545 nm under single-wavelength excitation were synthesized. It is demonstrated that the fluorescence intensities of the as-synthesized carbon dots at the two emissions are pH-sensitive simultaneously. The intensity ratio (I475 nm/I545 nm) is linear against pH values from 5.2 to 8.8 in buffer solution, affording the capability as ratiometric probes for intracellular pH sensing. It also displays that the carbon dots show excellent reversibility and photostability in pH measurements. With this nanoprobe, quantitative fluorescence imaging using the ratio of two emissions (I475 nm/I545 nm) for the detection of intracellular pH were successfully applied in HeLa cells. In contrast to most of the reported nanomaterials-based ratiometric pH sensors which rely on the attachment of additional dyes, these carbon-dots-based ratiometric probes are low in toxicity, easy to synthesize, and free from labels. PMID:27334762

  17. Flow cytometric measurement of intracellular pH.

    PubMed

    Chow, S; Hedley, D

    2001-05-01

    A number of fundamentally important biological processes, such as cell signaling and the initiation of mitosis, are accompanied by a change in intracellular pH. Flow cytometric measurement of pH is a generally straightforward procedure that can be done with any instrument equipped with a 488-nm argon laser. The overall approach is similar to that for calcium: generation of a calibration curve by imparting known changes in pH and interpolation of the test sample pH. This unit presents the traditional calibration method using high-potassium buffers and the proton ionophore nigericin and a more recently developed technique, the pseudo null method, which involves resuspension of cells in defined mixtures of weak acids and weak bases. PMID:18770756

  18. Commentary: PhDs in Biochemistry Education--5 Years Later

    ERIC Educational Resources Information Center

    Offerdahl, Erika G.; Momsen, Jennifer L.; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research.

  19. Ashley Felix, Ph.D., M.P.H.

    Cancer.gov

    NCI Cancer Prevention Fellowship Program (CPFP) alumna, Ashley Felix, Ph.D., M.P.H., details her transition from pre-med student to an epidemiologist who focuses on studying the causes and prevention of disease.

  20. Commentary: PhDs in biochemistry education-5 years later.

    PubMed

    Offerdahl, Erika G; Momsen, Jennifer L; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research.

  1. Stress-Corrosion Cracking in Martensitic PH Stainless Steels

    NASA Technical Reports Server (NTRS)

    Humphries, T.; Nelson, E.

    1984-01-01

    Precipitation-hardening alloys evaluated in marine environment tests. Report describes marine-environment stress-corrosion cracking (SCC) tests of three martensitic precipitation hardening (PH) stainless-steel alloys.

  2. The Training and Work of Ph.D. Physical Scientists

    NASA Astrophysics Data System (ADS)

    Smith, S. J.; Schweitzer, A. E.

    2003-05-01

    Doctoral education has often been viewed as the pinnacle of the formal education system. How useful is doctoral training in one's later career? In an NSF-funded project, we set out to perform a study of the training, careers, and work activities of Ph.D. physical scientists. The study included both in-depth interviews and a survey sent out to a sample of Ph.D. holders 4-8 years after graduation. Come and find out the results of this study: What skills are most Ph.D. physical scientists using? What should graduate programs be teaching? Are Ph.D.'s who are working in their specific field of training happier than their counterparts working different jobs? What skills and preparation lead to future job satisfaction, perhaps the most important indicator of the "success" of graduate education? A preprint and further details can be found at the project web site at: spot.colorado.edu/ phdcarer.

  3. Should MD-PhD Programs Encourage Graduate Training in Disciplines Beyond Conventional Biomedical or Clinical Sciences?

    PubMed Central

    O'Mara, Ryan J.; Hsu, Stephen I.; Wilson, Daniel R.

    2014-01-01

    The goal of MD–PhD training programs is to produce physician–scientists with unique capacities to lead the future biomedical research workforce. The current dearth of physician–scientists with expertise outside conventional biomedical or clinical sciences raises the question of whether MD–PhD training programs should allow or even encourage scholars to pursue doctoral studies in disciplines that are deemed nontraditional, yet are intrinsically germane to major influences on health. This question is especially relevant since the central value and ultimate goal of the academic medicine community is to help attain the highest level of health and health equity for all people. Advances in medical science and practice, along with improvements in health care access and delivery, are steps toward health equity, but alone they will not come close to eliminating health inequalities. Addressing the complex health issues in our communities and society as a whole requires a biomedical research workforce with knowledge, practice, and research skills well beyond conventional biomedical or clinical sciences. To make real progress in advancing health equity, educational pathways must prepare physician–scientists to treat both micro and macro determinants of health. The authors argue that MD–PhD programs should allow and encourage their scholars to cross boundaries into less traditional disciplines such as epidemiology, statistics, anthropology, sociology, ethics, public policy, management, economics, education, social work, informatics, communications, and marketing. To fulfill current and coming health care needs, non-traditional MD–PhD students should be welcomed and supported as valuable members of our biomedical research workforce. PMID:25354071

  4. Should MD-PhD programs encourage graduate training in disciplines beyond conventional biomedical or clinical sciences?

    PubMed

    O'Mara, Ryan J; Hsu, Stephen I; Wilson, Daniel R

    2015-02-01

    The goal of MD-PhD training programs is to produce physician-scientists with unique capacities to lead the future biomedical research workforce. The current dearth of physician-scientists with expertise outside conventional biomedical or clinical sciences raises the question of whether MD-PhD training programs should allow or even encourage scholars to pursue doctoral studies in disciplines that are deemed nontraditional, yet are intrinsically germane to major influences on health. This question is especially relevant because the central value and ultimate goal of the academic medicine community is to help attain the highest level of health and health equity for all people. Advances in medical science and practice, along with improvements in health care access and delivery, are steps toward health equity, but alone they will not come close to eliminating health inequalities. Addressing the complex health issues in our communities and society as a whole requires a biomedical research workforce with knowledge, practice, and research skills well beyond conventional biomedical or clinical sciences. To make real progress in advancing health equity, educational pathways must prepare physician-scientists to treat both micro and macro determinants of health. The authors argue that MD-PhD programs should allow and encourage their scholars to cross boundaries into less traditional disciplines such as epidemiology, statistics, anthropology, sociology, ethics, public policy, management, economics, education, social work, informatics, communications, and marketing. To fulfill current and coming health care needs, nontraditional MD-PhD students should be welcomed and supported as valuable members of our biomedical research workforce.

  5. Career Outcomes for Astronomy Ph.D. Graduates of the University of Texas at Austin: The Next Generation

    NASA Astrophysics Data System (ADS)

    Dinerstein, Harriet L.

    2011-01-01

    Sixteen years ago I conducted a survey of the career trajectories and outcomes of 78 individuals who earned Ph.D.s from the Department of Astronomy at the University of Texas at Austin during the period 1984-1995 (Dinerstein, H. 1996, AAS, 189.0501). In the current poster I extend these statistics up to the present, adding 68 Ph.D. recipients from 1996-2010. This is a sufficiently large sample to search for secular trends such as possible changes in duration of the postdoctoral stage, redistribution of demographics among different kinds of long-term positions, and the emergence of new categories of astronomy-related employment. The picture is less discouraging than one might expect. As of 2010, about 75% of the Texas graduates 7 - 14 years past the Ph.D. are still doing astronomy, and most of those in non-astronomical careers left the field by choice (and often have had considerable success in their alternate careers). Of those 6 years or less past the Ph.D., 50% were in postdoctoral positions and less than 10% had left astronomy. Recent reconsiderations of the employment market (Metcalfe, T.S. 2008, PASP, 120, 229; Seth, A. 2009, Astro2010: The Astronomy and Astrophysics Decadal Survey, Position Paper No. 51) make the point that a typical astronomer who ultimately achieves a permanent position will have held two or three prior temporary positions; this was equally true three decades ago. There has been notable growth nationwide in the number of astronomers employed as faculty at small liberal arts colleges and other undergraduate-centered institutions, a trend that to some degree was anticipated by the University of Texas cohort, which included a number of students for whom this was their personal goal. In a world where job certainty is no longer so prevalent, motivated and resourceful astronomers are finding ways to remain active members of our community.

  6. MD-PhD training: looking back and looking forward.

    PubMed

    Bonham, Ann C

    2014-01-01

    MD-PhD programs provide rigorous, integrated training for physician-scientists, enabling them to frame scientific questions in unique ways and to apply clinical insight to fundamental science. Few would question the influential contributions of MD-PhD physician-scientists in advancing medical science. In this issue of Academic Medicine, Jeffe et al affirm high levels of excellence in educational outcomes from MD-PhD training programs at U.S. MD-granting medical schools, especially programs that receive funding from the NIH Medical Scientist Training Program (MSTP). The author of this commentary observes that, in the face of current economic pressures, comprehensive, longitudinal national outcomes data from MSTP- and non-MSTP-funded MD-PhD programs will help verify the value provided by MD-PhD physician-scientists. She proposes that MD-PhD programs should better prepare the next generation of physician-scientists for future research environments, which will provide new technologies, venues, and modalities. These research environments will be more closely integrated within health care delivery systems, extend into diverse communities and regions, and employ complex technologies. MD-PhD physician-scientists also will train and gain expertise in broadening areas of research, such as health policy, health economics, clinical epidemiology, and medical informatics. Program leaders are ideally situated to foster innovative learning environments and methodologies. By sharing their innovations, they can help ensure production of a diverse MD-PhD physician-scientist workforce, prepared to engage in myriad research opportunities to meet patient and population needs in a new environment. PMID:24280863

  7. Glucosylceramide modulates endolysosomal pH in Gaucher disease.

    PubMed

    Sillence, Dan J

    2013-06-01

    GlcCer accumulation causes Gaucher disease where GlcCer breakdown is inhibited due to a hereditary deficiency in glucocerebrosidase. Glycolipids are endocytosed and targeted to the Golgi apparatus in normal cells but in Gaucher disease they are mistargeted to lysosomes. To better understand the role of GlcCer in endocytic sorting RAW macrophages were treated with Conduritol B-epoxide to inhibit GlcCer breakdown. Lipid analysis found increases in GlcCer led to accumulation of both triacylglycerol and cholesterol consistent with increased lysosomal pH. Ratio imaging of macrophages using both acridine orange and lysosensor yellow/blue to measure endolysosomal pH revealed increases in Conduritol B-epoxide treated RAW macrophages and Gaucher patient lymphoblasts. Increased endolysosomal pH was restricted to Gaucher lymphoblasts as no significant increases in pH were seen in Fabry, Krabbe, Tay-Sachs and GM1-gangliosidosis lymphoblasts. Substrate reduction therapy utilises inhibitors of GlcCer synthase to reduce storage in Gaucher disease. The addition of inhibitors of GlcCer synthesis to RAW macrophages also led to increases in cholesterol and triacylglycerol and an endolysosomal pH increase of up to 1 pH unit. GlcCer modulation appears specific since glucosylsphingosine but not galactosylsphingosine reversed the effects of GlcCer depletion. Although no acute effects on glycolipid trafficking were observed using bafilomycin A the results are consistent with a multistep model whereby increases in pH lead to altered trafficking via cholesterol accumulation. GlcCer modulates endolysosomal pH in lymphocytes suggesting an important role in normal lysosomes which may be disrupted in Gaucher disease. PMID:23628459

  8. The PhD in Writing Accompanied by an Exegesis

    ERIC Educational Resources Information Center

    Arnold, Josie

    2005-01-01

    The position of this paper is to further the discussion on what constitutes academic assessment in the PhD by artefact and exegesis. In doing so, it explores some of the ideas that arose in setting up the PhD in creative writing at Swinburne University of Technology. Thus, I: (1) survey some of the questions that arise about the journeys made by…

  9. Urea sensors based on PVC membrane pH electrode.

    PubMed

    Głab, S; Koncki, R; Kopczewska, E; Wałcerz, I; Hulanicki, A

    1994-07-01

    Several procedures of urease immobilization on the surface of the polymeric membrane pH electrode with tri-n-dodecylamine as a neutral carrier were compared. The best results were obtained for the urea sensor with covalently bound urease. The sensor characteristics including the effect of buffer, pH and concentration and the effect of stirring rate are presented. These effects are in good agreement with theoretical expectations.

  10. Transport mechanism of a glutamate transporter homologue GltPh

    PubMed Central

    Ji, Yurui; Postis, Vincent L.G.; Wang, Yingying; Bartlam, Mark; Goldman, Adrian

    2016-01-01

    Glutamate transporters are responsible for uptake of the neurotransmitter glutamate in mammalian central nervous systems. Their archaeal homologue GltPh, an aspartate transporter isolated from Pyrococcus horikoshii, has been the focus of extensive studies through crystallography, MD simulations and single-molecule FRET (smFRET). Here, we summarize the recent research progress on GltPh, in the hope of gaining some insights into the transport mechanism of this aspartate transporter. PMID:27284058

  11. MD-PhD training: looking back and looking forward.

    PubMed

    Bonham, Ann C

    2014-01-01

    MD-PhD programs provide rigorous, integrated training for physician-scientists, enabling them to frame scientific questions in unique ways and to apply clinical insight to fundamental science. Few would question the influential contributions of MD-PhD physician-scientists in advancing medical science. In this issue of Academic Medicine, Jeffe et al affirm high levels of excellence in educational outcomes from MD-PhD training programs at U.S. MD-granting medical schools, especially programs that receive funding from the NIH Medical Scientist Training Program (MSTP). The author of this commentary observes that, in the face of current economic pressures, comprehensive, longitudinal national outcomes data from MSTP- and non-MSTP-funded MD-PhD programs will help verify the value provided by MD-PhD physician-scientists. She proposes that MD-PhD programs should better prepare the next generation of physician-scientists for future research environments, which will provide new technologies, venues, and modalities. These research environments will be more closely integrated within health care delivery systems, extend into diverse communities and regions, and employ complex technologies. MD-PhD physician-scientists also will train and gain expertise in broadening areas of research, such as health policy, health economics, clinical epidemiology, and medical informatics. Program leaders are ideally situated to foster innovative learning environments and methodologies. By sharing their innovations, they can help ensure production of a diverse MD-PhD physician-scientist workforce, prepared to engage in myriad research opportunities to meet patient and population needs in a new environment.

  12. Teaching Human Digestion and pH Using Technology

    ERIC Educational Resources Information Center

    Kim, Hanna

    2008-01-01

    Testing the pH of various liquids is one of the most popular activities in 5th- through 8th-grade classrooms. The author presents an extensive pH-testing lesson based on a 5E (engagement, exploration, explanation, extension, and evaluation) teaching model. The activity provides students with the opportunity to learn about pH and how it relates to…

  13. Mouthguard and sports drinks on tooth surface pH.

    PubMed

    Maeda, Y; Yang, T-C; Miyanaga, H; Tanaka, Y; Ikebe, K; Akimoto, N

    2014-09-01

    The influence of sports drinks and mouthguards on the pH level of tooth surface was examined. A custom-made mouthguard was fabricated for each subject. The pH level was measured by electric pH meter with sensitivity of 0.01 up to 30 min. Sports drinks (pH=3.75) containing 9.4% sugar were used in this study. Measurements were performed on a cohort of 23 female subjects without a mouthguard (control), wearing a mouthguard only (MG), wearing a mouthguard after 30 ml sports drink intake (SD+MG), wearing a mouthguard during a 5-min jogging exercise (MG+EX) and wearing a mouthguard during jogging after sports drink intake (SD+MG+EX). For 7 male subjects, the same measurements were performed while a sports drink was taken over the mouthguard (MG+SD, MD+EX+SD). MG showed statistically higher pH level than control (p<0.05). SD+MG exhibited a significant decrease in pH level, and SD+MG+EX exhibited even below the critical level of pH 5.5 in some subjects. When sports drinks were taken over the mouthguard, no significant differences in pH level were observed among the different conditions.Within the limitations of this study, it was suggested that wearing a mouthguard during exercise is in itself not a possible risk factor for dental caries, while wearing a mouthguard after consuming sports drinks is.

  14. Dysregulated pH in Tumor Microenvironment Checkmates Cancer Therapy

    PubMed Central

    Barar, Jaleh; Omidi, Yadollah

    2013-01-01

    Introduction: The dysregulation of pH by cancerous cells of solid tumors is able to create a unique milieu that is in favor of progression, invasion and metastasis as well as chemo-/immuno-resistance traits of solid tumors. Bioelements involved in pH dysregulation provide new set of oncotargets, inhibition of which may result in better clinical outcome. Methods: To study the impacts of pH dysregulation, we investigated the tumor development and progression in relation with Warburg effect, glycolysis and formation of aberrant tumor microenvironment. Results: The upregulation of glucose transporter GLUT-1 and several enzymes involve in glycolysis exacerbates this phenomenon. The accumulation of lactic acids in cancer cells provokes upregulation of several transport machineries (MCT-1, NHE-1, CA IX and H+ pump V-ATPase) resulting in reinforced efflux of proton into extracellular fluid. This deviant event makes pH to be settled at 7.4 and 6.6 respectively in cancer cells cytoplasm and extracellular fluid within the tumor microenvironment, which in return triggers secretion of lysosomal components (various enzymes in acidic milieu with pH 5) into cytoplasm. All these anomalous phenomena make tumor microenvironment (TME) to be exposed to cocktail of various enzymes with acidic pH, upon which extracellular matrix (ECM) can be remodeled and even deformed, resulting in emergence of a complex viscose TME with high interstitial fluid pressure. Conclusion: It seems that pH dysregulation is able to remodel various physiologic functions and make solid tumors to become much more invasive and metastatic. It also can cause undesired resistance to chemotherapy and immunotherapy. Hence, cancer therapy needs to be reinforced using specific inhibitors of bioelements involved in pH dysregulation of TME in solid tumors. PMID:24455478

  15. Data Collection and Analysis Strategies for phMRI

    PubMed Central

    Mandeville, Joseph B.; Liu, Christina H.; Vanduffel, Wim; Marota, John J.A.; Jenkins, Bruce G.

    2014-01-01

    Although functional MRI traditionally has been applied mainly to study changes in task-induced brain function, evolving acquisition methodologies and improved knowledge of signal mechanisms have increased the utility of this method for studying responses to pharmacological stimuli, a technique often dubbed “phMRI”. The proliferation of higher magnetic field strengths and the use of exogenous contrast agent have boosted detection power, a critical factor for successful phMRI due to the restricted ability to average multiple stimuli within subjects. Receptor-based models of neurovascular coupling, including explicit pharmacological models incorporating receptor densities and affinities and data-driven models that incorporate weak biophysical constraints, have demonstrated compelling descriptions of phMRI signal induced by dopaminergic stimuli. This report describes phMRI acquisition and analysis methodologies, with an emphasis on data-driven analyses. As an example application, statistically efficient data-driven regressors were used to describe the biphasic response to the mu-opioid agonist remifentanil, and antagonism using dopaminergic and GABAergic ligands revealed modulation of the mesolimbic pathway. Results illustrate the power of phMRI as well as our incomplete understanding of mechanisms underlying the signal. Future directions are discussed for phMRI acquisitions in human studies, for evolving analysis methodologies, and for interpretative studies using the new generation of simultaneous PET/MRI scanners. PMID:24613447

  16. Economical wireless optical ratiometric pH sensor

    NASA Astrophysics Data System (ADS)

    Vuppu, Sandeep; Kostov, Yordan; Rao, Govind

    2009-04-01

    The development and application of a portable, wireless fluorescence-based optical pH sensor is presented. The design incorporates the MSP430 microcontroller as the control unit, an RF transceiver for wireless communication, digital filters and amplifiers and a USB-based communication module for data transmission. The pH sensor is based on ratiometric fluorescence detection from pH sensitive dye incorporated in a peel-and-stick patch. The ability of the instrument to detect the pH of the solution with contact only between the sensor patch and the solution makes it partially non-invasive. The instrument also has the ability to transmit data wirelessly, enabling its use in processes that entail stringent temperature control and sterility. The use of the microcontroller makes it a reliable, low-cost and low-power device. The luminous intensity of the light source can be digitally controlled to maximize the sensitivity of the instrument. It has a resolution of 0.05 pH. The sensor is accurate and reversible over the pH range of 6.5-9.

  17. Thermal and pH stability of pestiviruses.

    PubMed

    Depner, K; Bauer, T; Liess, B

    1992-09-01

    Three strains/isolates of hog cholera virus (HCV) and two strains/isolates each of cytopathogenic (cp) and non-cytopathogenic (ncp) biotype of bovine virus diarrhoea virus (BVDV) were each exposed to pH 3, 3.5 and 4 at 4 degrees C, 21 degrees C and 37 degrees C in a number of combinations. Infectivity titration and half-life determinations following correlation and regression analysis showed a significant temperature-dependent shortening of half-lives within the pH range investigated. At pH 3, mean half-lives were more than tenfold lower when HCV was kept at an ambient temperature of 21 degrees C rather than at 4 degrees C. Additionally, in some of the strains/isolates tested, half-lives of HCV kept at 4 degrees C were four to ten times lower when the pH was raised from 3 to 4. BVDV appeared more sensitive at 4 degrees C and pH 3 than HCV, but equally sensitive at 21 degrees C. Differences in temperature or pH stability between cp and ncp biotypes of BVDV could not be statistically verified although, in general, the cp biotypes seemed to be more stable than the ncp strains/isolates.

  18. Monitoring pH and ORP in a SHARON reactor.

    PubMed

    Claros, J; Serralta, J; Seco, A; Ferrer, J; Aguado, D

    2011-01-01

    This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH and ORP can be used to develop a real-time control system aimed at optimizing the length of both aerobic and anoxic stages. Real-time control of methanol addition can be carried out by using the information provided by these probes: excessive methanol addition in the anoxic stage is clearly detected in the ORP profile of the following aerobic phase, while a deficit of methanol is detected in both pH and ORP profiles of that anoxic phase. Moreover, other valuable information such as the amount of ammonia nitrified, failures in DO measurements, excessive stirring during the anoxic stage and methanol dosage in the aerobic phase was also provided by the pH and ORP profiles.

  19. Structure of human saposin A at lysosomal pH

    SciTech Connect

    Hill, Chris H.; Read, Randy J.; Deane, Janet E.

    2015-06-27

    A 1.8 Å resolution structure of the sphingolipid activator protein saposin A has been determined at pH 4.8, the physiologically relevant lysosomal pH for hydrolase enzyme activation and lipid-transfer activity. The saposins are essential cofactors for the normal lysosomal degradation of complex glycosphingolipids by acid hydrolase enzymes; defects in either saposin or hydrolase function lead to severe metabolic diseases. Saposin A (SapA) activates the enzyme β-galactocerebrosidase (GALC), which catalyzes the breakdown of β-d-galactocerebroside, the principal lipid component of myelin. SapA is known to bind lipids and detergents in a pH-dependent manner; this is accompanied by a striking transition from a ‘closed’ to an ‘open’ conformation. However, previous structures were determined at non-lysosomal pH. This work describes a 1.8 Å resolution X-ray crystal structure determined at the physiologically relevant lysosomal pH 4.8. In the absence of lipid or detergent at pH 4.8, SapA is observeed to adopt a conformation closely resembling the previously determined ‘closed’ conformation, showing that pH alone is not sufficient for the transition to the ‘open’ conformation. Structural alignments reveal small conformational changes, highlighting regions of flexibility.

  20. Influence of pH on the Structure and Function of Kiwi Pectin Methylesterase Inhibitor.

    PubMed

    Bonavita, Alessandro; Carratore, Vitale; Ciardiello, Maria Antonietta; Giovane, Alfonso; Servillo, Luigi; D'Avino, Rossana

    2016-07-27

    Pectin methylesterase is a pectin modifying enzyme that plays a key role in plant physiology. It is also an important quality-related enzyme in plant-based food products. The pectin methylesterase inhibitor (PMEI) from kiwifruit inhibits this enzyme activity and is widely used as an efficient tool for research purposes and also recommended in the context of fruit and vegetable processing. Using several methodologies of protein biochemistry, including circular dichroism and fluorescence spectroscopy, chemical modifications, direct protein-sequencing, enzyme activity, and bioinformatics analysis of the crystal structure, this study demonstrates that conformational changes occur in kiwi PMEI by the pH rising over 6.0 bringing about structure loosening, exposure, and cleavage of a natively buried disulfide bond, unfolding and aggregation, ultimately determining the loss of ability of kiwi PMEI to bind and inhibit PME. pH-induced structural changes are prevented when PMEI is already engaged in complex or is in a solution of high ionic strength. PMID:27335009

  1. Characterisation and deployment of an immobilised pH sensor spot towards surface ocean pH measurements.

    PubMed

    Clarke, Jennifer S; Achterberg, Eric P; Rérolle, Victoire M C; Abi Kaed Bey, Samer; Floquet, Cedric F A; Mowlem, Matthew C

    2015-10-15

    The oceans are a major sink for anthropogenic atmospheric carbon dioxide, and the uptake causes changes to the marine carbonate system and has wide ranging effects on flora and fauna. It is crucial to develop analytical systems that allow us to follow the increase in oceanic pCO2 and corresponding reduction in pH. Miniaturised sensor systems using immobilised fluorescence indicator spots are attractive for this purpose because of their simple design and low power requirements. The technology is increasingly used for oceanic dissolved oxygen measurements. We present a detailed method on the use of immobilised fluorescence indicator spots to determine pH in ocean waters across the pH range 7.6-8.2. We characterised temperature (-0.046 pH/°C from 5 to 25 °C) and salinity dependences (-0.01 pH/psu over 5-35), and performed a preliminary investigation into the influence of chlorophyll on the pH measurement. The apparent pKa of the sensor spots was 6.93 at 20 °C. A drift of 0.00014 R (ca. 0.0004 pH, at 25 °C, salinity 35) was observed over a 3 day period in a laboratory based drift experiment. We achieved a precision of 0.0074 pH units, and observed a drift of 0.06 pH units during a test deployment of 5 week duration in the Southern Ocean as an underway surface ocean sensor, which was corrected for using certified reference materials. The temperature and salinity dependences were accounted for with the algorithm, R=0.00034-0.17·pH+0.15·S(2)+0.0067·T-0.0084·S·1.075. This study provides a first step towards a pH optode system suitable for autonomous deployment. The use of a short duration low power illumination (LED current 0.2 mA, 5 μs illumination time) improved the lifetime and precision of the spot. Further improvements to the pH indicator spot operations include regular application of certified reference materials for drift correction and cross-calibration against a spectrophotometric pH system. Desirable future developments should involve novel

  2. Local pH tracking in living cells

    NASA Astrophysics Data System (ADS)

    Tsou, Chieh-Jui; Hsia, Chih-Hao; Chu, Jia-Yin; Hung, Yann; Chen, Yi-Ping; Chien, Fan-Ching; Chou, Keng C.; Chen, Peilin; Mou, Chung-Yuan

    2015-02-01

    Continuous and simultaneous 3D single-particle movement and local pH detection in HeLa cells were demonstrated for the first time by combining fluorescent mesoporous silica nanoparticles (FMSNs) and a single-particle tracking (SPT) technique with a precision of ~10 nm. FMSNs, synthesized by the co-condensation of both pH-sensitive and reference dyes with a silica/surfactant source, allow long-term reliable ratiometric pH measurements with a precision better than 0.3 pH unit because of their excellent brightness and stability. pH variation in the surrounding area of FMSNs during endocytosis was monitored in real-time. Acidification and low mobility of FMSNs were observed at the early endocytic stage, whereas basification and high mobility of FMSNs were observed at the late stage. Our results indicate that it is possible to monitor local pH changes in the environments surrounding nanoparticles during the cellular uptake process of FMSNs, which provides much needed information for designing an efficient drug delivery nanosystem.Continuous and simultaneous 3D single-particle movement and local pH detection in HeLa cells were demonstrated for the first time by combining fluorescent mesoporous silica nanoparticles (FMSNs) and a single-particle tracking (SPT) technique with a precision of ~10 nm. FMSNs, synthesized by the co-condensation of both pH-sensitive and reference dyes with a silica/surfactant source, allow long-term reliable ratiometric pH measurements with a precision better than 0.3 pH unit because of their excellent brightness and stability. pH variation in the surrounding area of FMSNs during endocytosis was monitored in real-time. Acidification and low mobility of FMSNs were observed at the early endocytic stage, whereas basification and high mobility of FMSNs were observed at the late stage. Our results indicate that it is possible to monitor local pH changes in the environments surrounding nanoparticles during the cellular uptake process of FMSNs, which

  3. Atomistic simulations of liquid crystal mixtures of alkoxy substituted phenylpyrimidines 2PhP and PhP14.

    PubMed

    Yan, Fangyong; Earl, David J

    2012-03-28

    We study liquid crystal mixtures of alkoxy substituted phenylpyrimidines 2-[4-(butyloxy)phenyl]-5-(octyloxy)pyrimidine (2PhP) and 2-[4-(tetradecyloxy)phenyl]-5-(tetradecyloxy)pyrimidine (PhP14) using molecular dynamics simulations at the all atom level. The molecular length of PhP14 is 1.8 times that of 2PhP, resulting in an interesting binary mixture phase diagram. Our simulations are composed of 1000-1600 molecules for a total of 80,000-130,000 atomic sites, with total simulation times of 60-100 ns. We first show that a pure 2PhP system self-assembles into isotropic, nematic, smectic A and smectic C phases, and a pure PhP14 system self-assembles into isotropic and smectic C phases. Binary mixtures of PhP14 and 2PhP display a stabilization of the smectic A phase at the expense of the smectic C and nematic phases. We determine that the concentration-induced phase transition from the smectic C to the smectic A phase in the mixture is driven by an out-of-layer fluctuation arrangement of the molecules. We also observe that the tilt angle in the smectic C phases formed in the mixtures is concentration dependent. The results of our simulations are in good agreement with the experimental findings of Kapernaum et al. [J. Org. Chem. 5, 65 (2009)], thus showing that atomistic simulations are capable of reproducing the phase behavior of liquid crystal mixtures and can also provide microscopic details regarding the mechanisms that govern phase stability.

  4. 17 CFR 240.15c3-1g - Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... holding companies of certain brokers or dealers (Appendix G to 17 CFR 240.15c3-1). 240.15c3-1g Section 240... Act of 1934 Rules Relating to Over-The-Counter Markets § 240.15c3-1g Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240.15c3-1). Link to an amendment published...

  5. 17 CFR 240.15c3-1g - Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... holding companies of certain brokers or dealers (Appendix G to 17 CFR 240.15c3-1). 240.15c3-1g Section 240... Act of 1934 Rules Relating to Over-The-Counter Markets § 240.15c3-1g Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240.15c3-1). As a condition for a broker...

  6. Effect of reduced sodium chloride concentration and tetrasodium pyrophosphate on pH, water-holding capacity and extractable protein of prerigor and postrigor ground beef.

    PubMed

    Bernthal, P H; Booren, A M; Gray, J I

    1991-01-01

    The effect of tetrasodium pyrophosphate (TSPP) (0, 0·25, 0·5% w/w) alone or in combination with salt (NaCl) (0, 0·5, 1·0% w/w) on water-holding capacity (WHC), pH, the ratio of absorbance at 250 nm over the absorbance at 260 nm (R-values) and 150m CaCl extractable protein (EP) was studied in prerigor and postrigor sternomandibularis homogenates over time. The 0 h samples were defined as when the NaCl was incorporated with the muscle. R-values verified that 0 h samples were in a prerigor or postrigor state. In prerigor homogenates, increasing phosphate concentration increased the time required to reach ultimate pH. Ultimate pH values of prerigor homogenates containing phosphate were lower (P < 0·05) than homogenates without phosphate and similarly treated postrigor homogenates. After six hours, no differences (P > 0·10) were noted in EP or WHC at different phosphate concentrations when averaged over NaCl concentrations in prerigor homogenates. With increasing phosphate concentration of postrigor homogenates, there was an increase (P < 0·05) in pH and EP at the initial sampling time. However, 0 and 0·25% phosphate WHC values could not be differentiated (P > 0·10). Results of this study indicate no advantages, after six hours post mortem, to using TSPP alone or in combination with NaCl in prerigor meat homogenates at concentrations added in this study.

  7. Long-term stability monitoring of pH reference materials using primary pH method.

    PubMed

    Gonzaga, Fabiano Barbieri; Dias, Júlio Cesar

    2015-04-01

    This work presents the results from a series of stability studies for some batches of different aqueous pH reference materials, packed in high-density polyethylene (HDPE) bottles, taking primary pH measurements over long periods (time lengths from 18.4 to 21.0 months). The results obtained over time for acid and neutral buffer solutions (nominal pH values of 1.68, 4.00, and 6.86 at 25 °C), considering their uncertainties, were statistically similar, demonstrating the high stability of these materials. On the other hand, for the alkaline buffer solutions (nominal pH values of 9.18 and 10.01 at 25 °C), there was a clear decrease in the results over time, with pH variation rates around -8.5 × 10(-4) per month. The results showed that reference materials of the acid and neutral buffer solutions can be easily provided with small uncertainty values and long shelf lives in simple HDPE bottles closed under air atmosphere, whereas reference materials of the alkaline buffer solutions must have more limited shelf lives and higher uncertainty values (taking into account the pH decrease over time) or must be provided in special packaging (such as ampoules) to prevent carbon dioxide interference. PMID:25318462

  8. Ligand Accessibility and Bioactivity of a Hormone-Dendrimer Conjugate Depend on pH and pH History

    PubMed Central

    Kim, Sung Hoon; Madak-Erdogan, Zeynep; Bae, Sung Chul; Carlson, Kathryn E.; Mayne, Christopher G.; Granick, Steve; Katzenellenbogen, Benita S.; Katzenellenbogen, John A.

    2016-01-01

    Estrogen conjugates with a polyamidoamine (PAMAM) dendrimer have shown remarkably selective regulation of the non-genomic actions of estrogens in target cells. In response to pH changes, however, these estrogen-dendrimer conjugates (EDCs) display a major morphological transition that alters the accessibility of the estrogen ligands that compromises the bioactivity of the EDC. A sharp break in dynamic behavior near pH 7 occurs for three different ligands on the surface of a PAMAM-G6 dendrimer: a fluorophore (tetramethylrhodamine, TMR) and two estrogens (17α-ethynylestradiol and diphenolic acid). Collisional quenching and time-resolved fluorescence anisotropy experiments with TMR-PAMAM reveal high ligand shielding above pH 7 and low shielding below pH 7. Furthermore, when pH was cycled from 8.5 (conditions of ligand-PAMAM conjugation) to 4.5 (e.g., endosome/lysosome) and through 6.5 (e.g., hypoxic environment) back to pH 8.5, the 17α-ethynylestradiol and diphenolic acid PAMAM conjugates experience a dramatic, irreversible loss in cell stimulatory activity; dynamic NMR studies indicate that the hormonal ligands had become occluded within the more hydrophobic core of the PAMAM dendrimer. Thus, the active state of these estrogen-dendrimer conjugates appears to be metastable. This pH-dependent irreversible masking of activity is of considerable relevance to the design of drug conjugates with amine-bearing PAMAM dendrimers. PMID:26186415

  9. Effect of systemic pH on pH sub i and lactic acid generation in exhaustive forearm exercise

    SciTech Connect

    Hood, V.L.; Schubert, C.; Keller, U.; Mueller, S. Univ. of Vermont College of Medicine, Burlington )

    1988-09-01

    To investigate whether changes in systemic pH affect intracellular pH (pH{sub i}), energy-rich phosphates, and lactic acid generation in muscle, eight normal volunteers performed exhaustive forearm exercise with arterial blood flow occluded for 2 min on three occasions. Subjects ingested 4 mmol/kg NH{sub 4}Cl (acidosis; A) or NaHCO{sub 3} (alkalosis; B) or nothing (control; C) 3 h before the exercise. Muscle pH{sub i} and phosphocreatine (PCr) content were measured with {sup 31}P-nuclear magnetic resonance ({sup 31}P-NMR) spectroscopy during exercise and recovery. Lactate output during 0.5-7 min of recovery was calculated as deep venous-arterial concentration differences times forearm blood flow. Before exercise, blood pH and bicarbonate were lower in acidosis than alkalosis and intermediate in control. Lactic acid output during recovery was less with A than B and intermediate in C. PCr utilization and resynthesis were not affected by extracellular pH changes. pH{sub i} did not differ before exercise or at its end. Hence systemic acidosis inhibited and alkalosis stimulated lactic acid output. These findings suggest that systemic pH regulates cellular acid production, protecting muscle pH, at the expense of energy availability.

  10. Measuring Phagosome pH by Ratiometric Fluorescence Microscopy.

    PubMed

    Nunes, Paula; Guido, Daniele; Demaurex, Nicolas

    2015-01-01

    Phagocytosis is a fundamental process through which innate immune cells engulf bacteria, apoptotic cells or other foreign particles in order to kill or neutralize the ingested material, or to present it as antigens and initiate adaptive immune responses. The pH of phagosomes is a critical parameter regulating fission or fusion with endomembranes and activation of proteolytic enzymes, events that allow the phagocytic vacuole to mature into a degradative organelle. In addition, translocation of H(+) is required for the production of high levels of reactive oxygen species (ROS), which are essential for efficient killing and signaling to other host tissues. Many intracellular pathogens subvert phagocytic killing by limiting phagosomal acidification, highlighting the importance of pH in phagosome biology. Here we describe a ratiometric method for measuring phagosomal pH in neutrophils using fluorescein isothiocyanate (FITC)-labeled zymosan as phagocytic targets, and live-cell imaging. The assay is based on the fluorescence properties of FITC, which is quenched by acidic pH when excited at 490 nm but not when excited at 440 nm, allowing quantification of a pH-dependent ratio, rather than absolute fluorescence, of a single dye. A detailed protocol for performing in situ dye calibration and conversion of ratio to real pH values is also provided. Single-dye ratiometric methods are generally considered superior to single wavelength or dual-dye pseudo-ratiometric protocols, as they are less sensitive to perturbations such as bleaching, focus changes, laser variations, and uneven labeling, which distort the measured signal. This method can be easily modified to measure pH in other phagocytic cell types, and zymosan can be replaced by any other amine-containing particle, from inert beads to living microorganisms. Finally, this method can be adapted to make use of other fluorescent probes sensitive to different pH ranges or other phagosomal activities, making it a generalized

  11. [Gastroesophageal reflux during pregnancy: 24-hour esophageal ph monitoring].

    PubMed

    Anton, C; Anton, E; Drug, V; Stanciu, C

    2001-01-01

    Gastroesophageal reflux (GER) occurs in 30-50% of all pregnancies. The progressive rise in plasma progesterone has been suggested as a possible mediator of GER during pregnancy. Recent advances in technology have made it possible to detect GER through monitoring of esophageal pH for prolonged periods, including sleep. 24-hour pH monitoring is the proper method for diagnosing GER in pregnant women. If 24-hour esophageal pH monitoring is to be a useful diagnostic tool, it must reliably discriminate GER patients despite daily variations in distal esophageal acid exposure. To address this issue, we studied 62 women (30 healthy non-pregnant women without GER symptoms and 32 pregnant women with GER symptoms-heartburn, acid regurgitation) with 24-hour esophageal pH monitoring. Intrasubject reproducibility of three pH parameters to discriminate the presence of abnormal acid reflux was determined (DeMeester score, Kaye score, circadian one hour diagram for pH < 4). Each patient was interviewed, using a reliable questionnaire detailing individual habits, life style characteristics and symptoms, at four time points during the first, second, third trimesters of pregnancy and post-partum period. Symptoms of GER are common in pregnancy and although GER rarely endangers maternal or fetal health, it can significantly affect patient comfort and quality of life. We conclude: 1. GER is almost constantly present during pregnancy, increasing with gestational age. 2. The most important pH--parameter is DeMcester score. 3. Heartburn disappear after delivery. 4. 24-hour esophageal pH monitoring is the gold standard for measuring acid exposure and is a reproducible test for the diagnosis of GER in pregnancy.

  12. Measuring Phagosome pH by Ratiometric Fluorescence Microscopy.

    PubMed

    Nunes, Paula; Guido, Daniele; Demaurex, Nicolas

    2015-12-07

    Phagocytosis is a fundamental process through which innate immune cells engulf bacteria, apoptotic cells or other foreign particles in order to kill or neutralize the ingested material, or to present it as antigens and initiate adaptive immune responses. The pH of phagosomes is a critical parameter regulating fission or fusion with endomembranes and activation of proteolytic enzymes, events that allow the phagocytic vacuole to mature into a degradative organelle. In addition, translocation of H(+) is required for the production of high levels of reactive oxygen species (ROS), which are essential for efficient killing and signaling to other host tissues. Many intracellular pathogens subvert phagocytic killing by limiting phagosomal acidification, highlighting the importance of pH in phagosome biology. Here we describe a ratiometric method for measuring phagosomal pH in neutrophils using fluorescein isothiocyanate (FITC)-labeled zymosan as phagocytic targets, and live-cell imaging. The assay is based on the fluorescence properties of FITC, which is quenched by acidic pH when excited at 490 nm but not when excited at 440 nm, allowing quantification of a pH-dependent ratio, rather than absolute fluorescence, of a single dye. A detailed protocol for performing in situ dye calibration and conversion of ratio to real pH values is also provided. Single-dye ratiometric methods are generally considered superior to single wavelength or dual-dye pseudo-ratiometric protocols, as they are less sensitive to perturbations such as bleaching, focus changes, laser variations, and uneven labeling, which distort the measured signal. This method can be easily modified to measure pH in other phagocytic cell types, and zymosan can be replaced by any other amine-containing particle, from inert beads to living microorganisms. Finally, this method can be adapted to make use of other fluorescent probes sensitive to different pH ranges or other phagosomal activities, making it a generalized

  13. PH5 for integrating and archiving different data types

    NASA Astrophysics Data System (ADS)

    Azevedo, Steve; Hess, Derick; Beaudoin, Bruce

    2016-04-01

    PH5 is IRIS PASSCAL's file organization of HDF5 used for seismic data. The extensibility and portability of HDF5 allows the PH5 format to evolve and operate on a variety of platforms and interfaces. To make PH5 even more flexible, the seismic metadata is separated from the time series data in order to achieve gains in performance as well as ease of use and to simplify user interaction. This separation affords easy updates to metadata after the data are archived without having to access waveform data. To date, PH5 is currently used for integrating and archiving active source, passive source, and onshore-offshore seismic data sets with the IRIS Data Management Center (DMC). Active development to make PH5 fully compatible with FDSN web services and deliver StationXML is near completion. We are also exploring the feasibility of utilizing QuakeML for active seismic source representation. The PH5 software suite, PIC KITCHEN, comprises in-field tools that include data ingestion (e.g. RefTek format, SEG-Y, and SEG-D), meta-data management tools including QC, and a waveform review tool. These tools enable building archive ready data in-field during active source experiments greatly decreasing the time to produce research ready data sets. Once archived, our online request page generates a unique web form and pre-populates much of it based on the metadata provided to it from the PH5 file. The data requester then can intuitively select the extraction parameters as well as data subsets they wish to receive (current output formats include SEG-Y, SAC, mseed). The web interface then passes this on to the PH5 processing tools to generate the requested seismic data, and e-mail the requester a link to the data set automatically as soon as the data are ready. PH5 file organization was originally designed to hold seismic time series data and meta-data from controlled source experiments using RefTek data loggers. The flexibility of HDF5 has enabled us to extend the use of PH5 in several

  14. Interfacial pH during mussel adhesive plaque formation

    PubMed Central

    Rodriguez, Nadine R. Martinez; Das, Saurabh; Kaufman, Yair; Israelachvili, Jacob N.; Waite, J. Herbert

    2015-01-01

    Mussel (Mytilus californianus) adhesion to marine surfaces involves an intricate and adaptive synergy of molecules and spatio-temporal processes. Although the molecules, such as mussel foot proteins (mfps), are well characterized, deposition details remain vague and speculative. Developing methods for the precise surveillance of conditions that apply during mfp deposition would aid both in understanding mussel adhesion and translating this adhesion into useful technologies. To probe the interfacial pH at which mussels buffer the local environment during mfp deposition, a lipid bilayer with tethered pH-sensitive fluorochromes was assembled on mica. The interfacial pH during foot contact with modified mica ranged from 2.2−3.3, which is well below the seawater pH of ~8. The acidic pH serves multiple functions: it limits mfp-Dopa oxidation, thereby enabling the catecholic functionalities to adsorb to surface oxides by H-bonding and metal ion coordination, and provides a solubility switch for mfps, most of which aggregate at pH ≥ 7-8. PMID:25875963

  15. Computational Analysis of the Binding Specificities of PH Domains

    PubMed Central

    Jiang, Zhi; Liang, Zhongjie; Shen, Bairong; Hu, Guang

    2015-01-01

    Pleckstrin homology (PH) domains share low sequence identities but extremely conserved structures. They have been found in many proteins for cellular signal-dependent membrane targeting by binding inositol phosphates to perform different physiological functions. In order to understand the sequence-structure relationship and binding specificities of PH domains, quantum mechanical (QM) calculations and sequence-based combined with structure-based binding analysis were employed in our research. In the structural aspect, the binding specificities were shown to correlate with the hydropathy characteristics of PH domains and electrostatic properties of the bound inositol phosphates. By comparing these structure properties with sequence-based profiles of physicochemical properties, PH domains can be classified into four functional subgroups according to their binding specificities and affinities to inositol phosphates. The method not only provides a simple and practical paradigm to predict binding specificities for functional genomic research but also gives new insight into the understanding of the basis of diseases with respect to PH domain structures. PMID:26881206

  16. Low pH increases the yield of exosome isolation.

    PubMed

    Ban, Jae-Jun; Lee, Mijung; Im, Wooseok; Kim, Manho

    2015-05-22

    Exosomes are the extracellular vesicles secreted by various cells. Exosomes mediate intercellular communication by delivering a variety of molecules between cells. Cancer cell derived exosomes seem to be related with tumor progression and metastasis. Tumor microenvironment is thought to be acidic and this low pH controls exosome physiology, leading to tumor progression. Despite the importance of microenvironmental pH on exosome, most of exosome studies have been performed without regard to pH. Therefore, the difference of exosome stability and yield of isolation by different pH need to be studied. In this research, we investigated the yield of total exosomal protein and RNA after incubation in acidic, neutral and alkaline conditioned medium. Representative exosome markers were investigated by western blot after incubation of exosomes in different pH. As a result, the concentrations of exosomal protein and nucleic acid were significantly increased after incubation in the acidic medium compared with neutral medium. The higher levels of exosome markers including CD9, CD63 and HSP70 were observed after incubation in an acidic environment. On the other hand, no exosomal protein, exosomal RNA and exosome markers have been detected after incubation in an alkaline condition. In summary, our results indicate that the acidic condition is the favorable environment for existence and isolation of exosomes.

  17. Intracellular pH and the Control of Multidrug Resistance

    NASA Astrophysics Data System (ADS)

    Simon, Sanford; Roy, Deborshi; Schindler, Melvin

    1994-02-01

    Many anticancer drugs are classified as either weak bases or molecules whose binding to cellular structures is pH dependent. Accumulation of these drugs within tumor cells should be affected by transmembrane pH gradients. Indeed, development of multidrug resistance (MDR) in tumor cells has been correlated with an alkaline shift of cytosolic pH. To examine the role of pH in drug partitioning, the distribution of two drugs, doxorubicin and daunomycin, was monitored in fibroblasts and myeloma cells. In both cell types the drugs rapidly accumulated within the cells. The highest concentrations were measured in the most acidic compartments-e.g., lysosomes. Modifying the cellular pH in drug-sensitive cells to mimic reported shifts in MDR caused an immediate change in the cellular drug concentration. Drug accumulation was enhanced by acidic shifts and reversed by alkaline shifts. All of these effects were rapid and reversible. These results demonstrate that the alkaline shift observed in MDR is sufficient to prevent the accumulation of chemotherapeutic drugs independent of active drug efflux.

  18. Tin(IV) halide complexes of AsPh3) The structures of trans-SnCl4(AsPh3)2 and SnBr4(AsPh3).AsPh3.

    PubMed

    Mahon, Mary F; Moldovan, Natalia L; Molloy, Kieran C; Muresan, Alexandra; Silaghi-Dumitrescu, Ioan; Silaghi-Dumitrescu, Luminita

    2004-12-01

    The structures of two 1 : 2 adducts between tin(IV) halides and AsPh(3) have been determined. SnCl(4)(AsPh(3))(2) adopts a six-coordinate geometry at tin in which the two organoarsine donors are mutually trans. In contrast, SnBr(4)(AsPh(3))(2) is five-coordinate at tin and only one arsine is directly bonded to the metal, in an axial site of the trigonal bipyramid. The second AsPh(3) group has a close contact with the axially bound bromine [As...Br: 3.567(3) angstroms], which is a unique structural variation that depicts an intermediate in a halogen-transfer reaction between Group 14 and Group 15 elements. AACVD using SnCl(4)(AsPh(3))(2) generates a film containing SnO(2) and a second crystalline material which is possibly SnCl(2), but which contains no arsenic. PMID:15558128

  19. Near-infrared noninvasive spectroscopic determination of pH

    SciTech Connect

    Alam, Mary K.; Robinson, Mark R.

    1998-08-11

    Methods and apparatus for, preferably, determining noninvasively and in vitro pH in a human. The non-invasive method includes the steps of: generating light at three or more different wavelengths in the range of 1000 nm to 2500 nm; irradiating blood containing tissue; measuring the intensities of the wavelengths emerging from the blood containing tissue to obtain a set of at least three spectral intensities v. wavelengths; and determining the unknown values of pH. The determination of pH is made by using measured intensities at wavelengths that exhibit change in absorbance due to histidine titration. Histidine absorbance changes are due to titration by hydrogen ions. The determination of the unknown pH values is performed by at least one multivariate algorithm using two or more variables and at least one calibration model. The determined pH values are within the physiological ranges observed in blood containing tissue. The apparatus includes a tissue positioning device, a source, at least one detector, electronics, a microprocessor, memory, and apparatus for indicating the determined values.

  20. Ocean Acidification: Euphausia Pacifica's Response to Decreasing pH

    NASA Astrophysics Data System (ADS)

    Weber, H. N.; Cooper, H.

    2014-12-01

    The increasing rate of CO2 accumulating in Earth's oceans creates a threat to organisms that can lead to disturbances in their reproduction, survival and growth. Euphausia pacifica is the dominant species of krill in Monterey Bay, CA, and a keystone species in the bay's food web. Previous work on the effects of ocean acidification on the survival, growth and molting of E. pacifica have shown they are fairly tolerant to increased CO2 concentrations. However, less is known about energy costs associated with maintaining their internal pH levels which could affect food consumption, swimming behavior or growth activity. We hypothesized that krill exposed to high CO2 will increase their feeding rate on local species of phytoplankton to account for increased energy costs of pH buffering activity. We exposed experimental E. pacifica to waters of pH 7.6 (the expected pH surface waters in year 2100), and pH 8.0 (control) periods.test for acclimation or longer term stress. Feeding rates were calculated as changes in phytoplankton counts over 24 hours of feeding using Frost's equations (Frost 1972). Understanding the way E. pacifica is affected by ocean acidification is important because of the role they play as the primary food source for a variety of predators necessary to maintain the Pacific's ecology.