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Sample records for na falange proximal

  1. Ionic regulation of Na absorption in proximal colon: cation inhibition of electroneutral Na absorption

    SciTech Connect

    Sellin, J.H.; De Soignie, R.

    1987-01-01

    Active Na absorption (J/sub net//sup NA/) in rabbit proximal colon in vitro is paradoxically stimulated as (Na) in the bathing media is lowered with constant osmolarity. J/sub m..-->..s//sup Na/ increases almost linearly from 0 to 50 mM (Na)/sub 0/ but then plateaus and actually decreases from 50 to 140 mM (Na)/sub 0/, consistent with inhibition of an active transport process. Both lithium and Na are equally effective inhibitors of J/sub net//sup Na/, whereas choline and mannitol do not block the high rate of J/sub net//sup Na/ observed in decreased (Na)/sub 0/. Either gluconate or proprionate replacement of Cl inhibits J/sub net//sup Na/. J/sub net//sup Na/ at lowered (Na)/sub 0/ is electrically silent and is accompanied by increased Cl absorption; it is inhibited by 10/sup -3/ M amiloride and 10/sup -3/ theophylline but not by 10/sup -4/ M bumetanide. Epinephrine is equally effective at stimulating Na absorption at 50 and 140 mM (Na). Na gradient experiments are consistent with a predominantly serosal effect of the decreased (Na)/sub 0/. These results suggest that 1) Na absorption in rabbit proximal colon in vitro is stimulated by decreased (Na); 2) the effect is cation specific, both Na and Li blocking the stimulatory effect; 3) the transport is mediated by Na-H exchange and is Cl dependent but 4) is under different regulatory mechanisms than the epinephrine-sensitive Na-Cl cotransport previously described in proximal colon. Under the appropriate conditions, proximal colon absorbs Na extremely efficiently. Na-H exchange in this epithelium is cation inhibitable, either directly or by a secondary regulatory process.

  2. Autocrine inhibition of Na+/K(+)-ATPase by nitric oxide in mouse proximal tubule epithelial cells.

    PubMed Central

    Guzman, N J; Fang, M Z; Tang, S S; Ingelfinger, J R; Garg, L C

    1995-01-01

    An inducible nitric oxide synthase has recently been described in proximal tubule epithelium. To investigate the effects of proximal tubule NO on Na+/K(+)-ATPase, we induced NO production in mouse proximal tubule epithelial cells by treatment with lipopolysaccharide (LPS) and interferon-gamma (IFN gamma) followed by determinations of ouabain-sensitive ATPase activity. Na+/K(+)-ATPase activity decreased after 4 h of LPS/IFN gamma treatment, reaching maximal inhibition after 24 h (34% reduction in activity). The inhibition of Na+/K(+)-ATPase activity by LPS/IFN gamma was prevented by simultaneous incubation with N omega-nitro L-arginine and markedly blunted by removal of L-arginine from the medium. The NO donors sodium nitroprusside and SIN-1 also inhibited Na+/K(+)-ATPase activity to a similar extent than LPS/IFN gamma. However, treatment with 8-pCPT-cGMP only modestly reduced Na+/K(+)-ATPase activity. Interestingly, superoxide dismutase prevented the inhibitory effects of NO on Na+/K(+)-ATPase activity, suggesting a role for peroxynitrite in this inhibition. We conclude that NO generated by mouse proximal tubule epithelial cell iNOS inhibits Na/K ATPase activity in an autocrine fashion and that this inhibition is accompanied by a reduction in Na-dependent solute transport. PMID:7537754

  3. Regulation of Na-Cl absorption in rabbit proximal colon in vitro

    SciTech Connect

    Sellin, J.H.; De Siognie, R.

    1987-01-01

    Ion transport in rabbit proximal colon (PC) in vitro is dominated by a Na-Cl cotransport system stimulated by epinephrine. To further characterize the regulation of Na-Cl transport, the authors tested the effects of specific adrenergic agonists on ion fluxes under short-circuit conditions. Additionally, they tested the effects of the transport inhibitors bumetanide, furosemide, and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS). Basal Na and Cl absorption were essentially nil. The ..cap alpha../sub 2/-agonist clonidine significantly increased net Na and Cl absorption. The ..cap alpha../sub 1/-agonist phenylephrine and the ..beta..-agonist isoproterenol did not alter ion transport. The ..cap alpha../sub 2/-blocker yohimbine (YOH) had a complex, concentration-dependent effect. Propranolol (10/sup -5/ M) and pracozin (10/sup -6/ M) did not significantly alter either basal or stimulated ion transport. Neither bumetanide (10/sup -6/ or 10/sup -4/ M) nor furosemide (10/sup -4/ M) blocked epinephrine-stimulated Na absorption. SITS (10/sup -4/ M) and removal of mucosal K did not have a significant effect on ion transport. Conclusions: 1) Na-Cl cotransport in rabbit PC is primarily under ..cap alpha../sub 2/-adrenergic control, 2) YOH at high concentrations acts as an agonist in PC, 3) ..cap alpha../sub 2/-adrenergic agonists stimulate Na-Cl absorption in both rabbit ileum and PC. In PC, however, the process is electrically quiet and therefore does not appear to be associated with electrogenic HCO/sub 3/ secretion as found in ileum, 4) the lack of effect of bumetanide, furosemide, and 0 K on Na transport suggests that a single Na-Cl (or Na-K-2Cl) carrier is not involved in Na-Cl cotransport in proximal colon.

  4. Na sup + -H sup + exchanger in proximal cells isolated from rabbit kidney. I. Functional characteristics

    SciTech Connect

    Bidet, M.; Tauc, M.; Merot, J.; Vandewalle, A.; Poujeol, P. )

    1987-11-01

    The purpose of this study was to investigate the characteristics of the Na{sup +}-H{sup +} exchange in isolated proximal cells from rabbit kidney cortex. The cells were prepared by mechanical dissociation and sequential passages through nylon meshes. The intracellular pH (pH{sub i}) was measured in a bicarbonate-free medium using the fluorescent dye 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF). Resting pH{sub i} was 7.13 {+-} 0.04. Cells were acid loaded with nigericin in choline solution and H{sup +} efflux, induced by extracellular Na{sup +} (Na{sub e}), was calculated using a buffering power of 23.6 {+-} 0.6 mmol {center dot} l{sup {minus}1} {center dot} pH unit{sup {minus}1} estimated by NH{sub 4}Cl exposure. The intracellular H{sup +} concentration dependence did not follow simple Michaelis-Menten kinetics. Of the different cations tested on pH{sub i} recovery, such as Li{sup +}, choline{sup +}, K{sup +}, and tetramethylammonium, only Li{sup +} induced an alkalinization of acidified cells similar to that of Na{sup +}. {sup 22}Na influx measurements indicated that cellular depletion of Na{sup +} stimulated Na{sup +}-H{sup +} exchange. The results permit the conclusion that the isolation procedures did not impair the main features of the Na{sup +}-H{sup +} antiporter, at least as compared with those previously described in renal brush-border membrane vesicles or in other cellular systems. The integrity of the transporter in isolated proximal cells would permit the direct study of its hormonal and metabolic control.

  5. Local pH domains regulate NHE3-mediated Na+ reabsorption in the renal proximal tubule

    PubMed Central

    Burford, James L.; McDonough, Alicia A.; Holstein-Rathlou, Niels-Henrik; Peti-Peterdi, Janos

    2014-01-01

    The proximal tubule Na+/H+ exchanger 3 (NHE3), located in the apical dense microvilli (brush border), plays a major role in the reabsorption of NaCl and water in the renal proximal tubule. In response to a rise in blood pressure NHE3 redistributes in the plane of the plasma membrane to the base of the brush border, where NHE3 activity is reduced. This NHE3 redistribution is assumed to provoke pressure natriuresis; however, it is unclear how NHE3 redistribution per se reduces NHE3 activity. To investigate if the distribution of NHE3 in the brush border can change the reabsorption rate, we constructed a spatiotemporal mathematical model of NHE3-mediated Na+ reabsorption across a proximal tubule cell and compared the model results with in vivo experiments in rats. The model predicts that when NHE3 is localized exclusively at the base of the brush border, it creates local pH microdomains that reduce NHE3 activity by >30%. We tested the model's prediction experimentally: the rat kidney cortex was loaded with the pH-sensitive fluorescent dye BCECF, and cells of the proximal tubule were imaged in vivo using confocal fluorescence microscopy before and after an increase of blood pressure by ∼50 mmHg. The experimental results supported the model by demonstrating that a rise of blood pressure induces the development of pH microdomains near the bottom of the brush border. These local changes in pH reduce NHE3 activity, which may explain the pressure natriuresis response to NHE3 redistribution. PMID:25298526

  6. Fructose stimulates Na/H exchange activity and sensitizes the proximal tubule to angiotensin II.

    PubMed

    Cabral, Pablo D; Hong, Nancy J; Hye Khan, Md Abdul; Ortiz, Pablo A; Beierwaltes, William H; Imig, John D; Garvin, Jeffrey L

    2014-03-01

    The proximal nephron reabsorbs 60% to 70% of the fluid and sodium and most of the filtered bicarbonate via Na/H exchanger 3. Enhanced proximal nephron transport is implicated in hypertension. Our findings show that a fructose-enriched diet causes salt sensitivity. We hypothesized that fructose stimulates luminal Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. Na/H exchange was measured in rat proximal tubules as the rate of intracellular pH (pHi) recovery in fluorescent units/s. Replacing 5 mmol/L glucose with 5 mmol/L fructose increased the rate of pHi recovery (1.8±0.6 fluorescent units/s; P<0.02; n=8). Staurosporine, a protein kinase C inhibitor, blocked this effect. We studied whether this effect was because of the addition of fructose or removal of glucose. The basal rate of pHi recovery was first tested in the presence of a 0.6-mmol/L glucose and 1, 3, or 5 mmol/L fructose added in a second period. The rate of pHi recovery did not change with 1 mmol/L but it increased with 3 and 5 mmol/L of fructose. Adding 5 mmol/L glucose caused no change. Removal of luminal sodium blocked pHi recovery. With 5.5 mmol/L glucose, angiotensin II (1 pmol/L) did not affect the rate of pHi recovery (change, -1.1±0.5 fluorescent units/s; n=9) but it increased the rate of pHi recovery with 0.6 mmol/L glucose/5 mmol/L fructose (change, 4.0±2.2 fluorescent units/s; P<0.02; n=6). We conclude that fructose stimulates Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. This mechanism is likely dependent on protein kinase C. These results may partially explain the mechanism by which a fructose diet induces hypertension.

  7. Mechanism of NaCl and water reabsorption in the proximal convoluted tubule of rat kidney.

    PubMed Central

    Neumann, K H; Rector, F C

    1976-01-01

    The role of chloride concentration gradients in proximal NaCl and water reabsorption was examined in superficial proximal tubules of the rat by using perfusion and collection techniques. Reabsorptive rates (Jv), chloride concentrations, and transtubular potential difference were measured during perfusion with solutions (A) simulating an ultrafiltrate of plasma; (B) similar to (A) except that 20 meq/liter bicarbonate was replaced with acetate; (C) resembling late proximal fluid (glucose, amino acid, acetate-free, low bicarbonate, and high chloride); and (D) in which glucose and amino acids were replaced with raffinose and bicarbonate was partially replaced by poorly reabsorbable anions (cyclamate,sulfate, and methyl sulfate). In tubules perfused with solutions A and B, Jv were 2.17 and 2.7 nl mm-1 min-1 and chloride concentrations were 131.5 +/- 3.1 and 135 +/- 395 meq/liter, respectively, indicating that reabsorption is qualitatively similar to free-flow conditions and that acetate adequately replaces bicarbonate. With solution C, Jv was 2.10 nl mm-1 min-1 and potential difference was +1.5 +/- 0.2 mV, indicating that the combined presence of glucose, alanine, acetate, and bicarbonate per se is not an absolute requirement. Fluid reabsorption was virtually abolished when tubules were perfused with D solutions; Jv was not significantly different from zero despite sodium and chloride concentrations similar to plasma; chloride concentration was 110.8 +/- 0.2 meq/liter and potential difference was -0.98 mV indicating that chloride was close to electrochemical equilibrium. These results suggest the importance of the chloride gradient to proximal tubule reabsorption in regions where actively reabsorbable solutes (glucose, alanine, acetate, and bicarbonate) are lacking and provide further evidence for a passive model of NaCl and water transport. PMID:993334

  8. Na+-H+ exchanger-1 (NHE1) regulation in kidney proximal tubule.

    PubMed

    Parker, Mark D; Myers, Evan J; Schelling, Jeffrey R

    2015-06-01

    The ubiquitously expressed plasma membrane Na(+)-H(+) exchanger NHE1 is a 12 transmembrane-spanning protein that directs important cell functions such as homeostatic intracellular volume and pH control. The 315 amino acid cytosolic tail of NHE1 binds plasma membrane phospholipids and multiple proteins that regulate additional, ion-translocation independent functions. This review focuses on NHE1 structure/function relationships, as well as the role of NHE1 in kidney proximal tubule functions, including pH regulation, vectorial Na(+) transport, cell volume control and cell survival. The implications of these functions are particularly critical in the setting of progressive, albuminuric kidney diseases, where the accumulation of reabsorbed fatty acids leads to disruption of NHE1-membrane phospholipid interactions and tubular atrophy, which is a poor prognostic factor for progression to end stage renal disease. This review amplifies the vital role of the proximal tubule NHE1 Na(+)-H(+) exchanger as a kidney cell survival factor.

  9. Phosphoinositide binding differentially regulates NHE1 Na+/H+ exchanger-dependent proximal tubule cell survival.

    PubMed

    Abu Jawdeh, Bassam G; Khan, Shenaz; Deschênes, Isabelle; Hoshi, Malcolm; Goel, Monu; Lock, Jeffrey T; Shinlapawittayatorn, Krekwit; Babcock, Gerald; Lakhe-Reddy, Sujata; DeCaro, Garren; Yadav, Satya P; Mohan, Maradumane L; Naga Prasad, Sathyamangla V; Schilling, William P; Ficker, Eckhard; Schelling, Jeffrey R

    2011-12-09

    Tubular atrophy predicts chronic kidney disease progression, and is caused by proximal tubular epithelial cellcaused by proximal tubular epithelial cell (PTC) apoptosis. The normally quiescent Na(+)/H(+) exchanger-1 (NHE1) defends against PTC apoptosis, and is regulated by PI(4,5)P(2) binding. Because of the vast array of plasma membrane lipids, we hypothesized that NHE1-mediated cell survival is dynamically regulated by multiple anionic inner leaflet phospholipids. In membrane overlay and surface plasmon resonance assays, the NHE1 C terminus bound phospholipids with low affinity and according to valence (PIP(3) > PIP(2) > PIP = PA > PS). NHE1-phosphoinositide binding was enhanced by acidic pH, and abolished by NHE1 Arg/Lys to Ala mutations within two juxtamembrane domains, consistent with electrostatic interactions. PI(4,5)P(2)-incorporated vesicles were distributed to apical and lateral PTC domains, increased NHE1-regulated Na(+)/H(+) exchange, and blunted apoptosis, whereas NHE1 activity was decreased in cells enriched with PI(3,4,5)P(3), which localized to basolateral membranes. Divergent PI(4,5)P(2) and PI(3,4,5)P(3) effects on NHE1-dependent Na(+)/H(+) exchange and apoptosis were confirmed by selective phosphoinositide sequestration with pleckstrin homology domain-containing phospholipase Cδ and Akt peptides, PI 3-kinase, and Akt inhibition in wild-type and NHE1-null PTCs. The results reveal an on-off switch model, whereby NHE1 toggles between weak interactions with PI(4,5)P(2) and PI(3,4,5)P(3). In response to apoptotic stress, NHE1 is stimulated by PI(4,5)P(2), which leads to PI 3-kinase activation, and PI(4,5)P(2) phosphorylation. The resulting PI(3,4,5)P(3) dually stimulates sustained, downstream Akt survival signaling, and dampens NHE1 activity through competitive inhibition and depletion of PI(4,5)P(2).

  10. Phospholemman regulates cardiac Na+/Ca2+ exchanger by interacting with the exchanger's proximal linker domain.

    PubMed

    Zhang, Xue-Qian; Wang, Jufang; Carl, Lois L; Song, Jianliang; Ahlers, Belinda A; Cheung, Joseph Y

    2009-04-01

    Phospholemman (PLM) belongs to the FXYD family of small ion transport regulators. When phosphorylated at Ser(68), PLM inhibits cardiac Na(+)/Ca(2+) exchanger (NCX1). We previously demonstrated that the cytoplasmic tail of PLM interacts with the proximal intracellular loop (residues 218-358), but not the transmembrane (residues 1-217 and 765-938) or Ca(2+)-binding (residues 371-508) domains, of NCX1. In this study, we used intact Na(+)/Ca(2+) exchanger with various deletions in the intracellular loop to map the interaction sites with PLM. We first demonstrated by Western blotting and confocal immunofluorescence microscopy that wild-type (WT) NCX1 and its deletion mutants were expressed in transfected HEK-293 cells. Cotransfection with PLM and NCX1 (or its deletion mutants) in HEK-293 cells did not decrease expression of NCX1 (or its deletion mutants). Coexpression of PLM with WT NCX1 inhibited NCX1 current (I(NaCa)). Deletion of residues 240-679, 265-373, 250-300, or 300-373 from WT NCX1 resulted in loss of inhibition of I(NaCa) by PLM. Inhibition of I(NaCa) by PLM was preserved when residues 229-237, 270-300, 328-330, or 330-373 were deleted from the intracellular loop of NCX1. These results suggest that PLM mediated inhibition of I(NaCa) by interacting with two distinct regions (residues 238-270 and 300-328) of NCX1. Indeed, I(NaCa) measured in mutants lacking residues 238-270, 300-328, or 238-270 + 300-328 was not affected by PLM. Glutathione S-transferase pull-down assays confirmed that PLM bound to fragments corresponding to residues 218-371, 218-320, 218-270, 238-371, and 300-373, but not to fragments encompassing residues 250-300 and 371-508 of NCX1, indicating that residues 218-270 and 300-373 physically associated with PLM. Finally, acute regulation of I(NaCa) by PLM phosphorylation observed with WT NCX1 was absent in 250-300 deletion mutant but preserved in 229-237 deletion mutant. We conclude that PLM mediates its inhibition of NCX1 by interacting with

  11. Na sup + -H sup + exchanger in proximal cells isolated from kidney. II. Short-term regulation by glucocorticoids

    SciTech Connect

    Bidet, M.; Merot, J.; Tauc, M.; Poujeol, P. )

    1987-11-01

    The purpose of this study was to investigate the acute regulation by glucocorticoid of the Na{sup +}-H{sup +} exchanger in isolated renal proximal cells of the rabbit. The changes of intracellular pH (pH{sub i}) were determined in a bicarbonate-free buffer by the use of a fluorescent pH probe that may be trapped intracellularly, 2,7-biscarboxyethyl- 5(6)- carboxyfluorescein (BCECF). The activity of the Na{sup +}-H{sup +} exchanger was estimated by measuring the Na{sup +}-induced H{sup +} efflux in BCECF-loaded cells acid loaded with nigericin in choline medium. The uptake of 1.5 mM {sup 22}Na was also studied in Na{sup +}-depleted cells. Acute application of dexamethasone increased the activity of the Na{sup +}-H{sup +} exchanger. The effect on the kinetics of amiloride-sensitive Na{sup +}-H{sup +} exchange indicated that dexamethasone (DEX) increased the activity by increasing the V{sub max} of the carrier for external sodium and for external H{sup +}. The apparent affinity was not modified either for Na{sup +} or for H{sup +}. The glucocorticoid action was undetectable after pretreatment of cells with actinomycin D or cycloheximide. Acute glucocorticoid activation of the Na{sup +}-H{sup +} exchanger in isolated proximal cells required RNA and protein synthesis and was consistent with an increase in the number of carriers in the membrane.

  12. ATP is a coupling modulator of parallel Na,K-ATPase-K-channel activity in the renal proximal tubule.

    PubMed Central

    Tsuchiya, K; Wang, W; Giebisch, G; Welling, P A

    1992-01-01

    A fundamental and essential property of nearly all salt-transporting epithelia is the tight parallel coupling between the magnitude of the K-conductive pathway at the basolateral membrane and the activity of the Na,K-dependent ATPase (Na,K-ATPase). In the present study, we demonstrate that the coupling response in the renal proximal tubule is governed, at least in part, through the interaction between ATP-sensitive K channels and Na,K-ATPase-mediated changes in intracellular ATP levels. First, we identified a K-selective channel at the basolateral membrane, which is inhibited by the cytosolic addition of ATP. Second, conventional microelectrode analysis in the isolated perfused proximal straight tubule revealed that these channels are the major determinant of the macroscopic K conductance so that ATP-mediated changes in the open probability of the K channel could alter the extent of K recycling. Indeed, the increase in the macroscopic K conductance upon stimulation of transcellular Na transport and pump activity was found to be paralleled by a decrease in intracellular ATP. Finally, a causal link between parallel Na,K-ATPase-K-channel activity and ATP was established by the finding that intracellular ATP loading uncoupled the response. With our recent observations that similar ATP-sensitive K channels are expressed abundantly in other epithelia, we postulate that ATP may act as a universal coupling modulator of parallel Na,K-ATPase-K-channel activity. PMID:1321439

  13. Angiotensin II stimulates renal proximal tubule Na(+)-ATPase activity through the activation of protein kinase C.

    PubMed

    Rangel, L B A; Caruso-Neves, C; Lara, L S; Lopes, A G

    2002-08-31

    Recently, our group described an AT(1)-mediated direct stimulatory effect of angiotensin II (Ang II) on the Na(+)-ATPase activity of proximal tubules basolateral membranes (BLM) [Am. J. Physiol. 248 (1985) F621]. Data in the present report suggest the participation of a protein kinase C (PKC) in the molecular mechanism of Ang II-mediated stimulation of the Na(+)-ATPase activity due to the following observations: (i) the stimulation of protein phosphorylation in BLM, induced by Ang II, is mimicked by the PKC activator TPA, and is completely reversed by the specific PKC inhibitor, calphostin C; (ii) the Na(+)-ATPase activity is stimulated by Ang II and TPA in the same magnitude, being these effects abolished by the use of the PKC inhibitors, calphostin C and sphingosine; (iii) the Na(+)-ATPase activity is activated by catalytic subunit of PKC (PKC-M), in a similar and nonadditive manner to Ang II; and (iv) Ang II stimulates the phosphorylation of MARCKS, a specific substrate for PKC.

  14. Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells.

    PubMed

    Massey, Katherine J; Li, Quanwen; Rossi, Noreen F; Keezer, Susan M; Mattingly, Raymond R; Yingst, Douglas R

    2016-02-01

    How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser(938) were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K · mg protein(-1) · min(-1) and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser(938) is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells.

  15. Renal Proximal Tubule Na,K-ATPase is Controlled by CREB Regulated Transcriptional CoActivators as well as Salt Inducible Kinase 1

    PubMed Central

    Taub, Mary; Garamella, Sudha; Kim, Dongwook; Rajkhowa, Trivikram; Cutuli, Facundo

    2015-01-01

    Sodium reabsorption by the kidney is regulated by locally produced natriuretic and anti-natriuretic factors, including dopamine and norepinephrine, respectively. Previous studies indicated that signaling events initiated by these natriuretic and anti-natriuretic factors achieve their effects by altering the phosphorylation of Na,K-ATPase in the renal proximal tubule, and that Protein Kinase A (PKA) and Calcium mediated signaling pathways are involved. The same signaling pathways also control the transcription of the Na,K-ATPase β subunit gene atp1b1 in renal proximal tubule cells. In this report, evidence is presented that 1) both the recently discovered cAMP-Regulated Transcriptional Coactivators (CRTCs), and Salt Inducible Kinase 1 (SIK1) contribute to the transcriptional regulation of atp1b1 in renal proximal tubule (RPT) cells, and 2) that renal effectors including norepinephrine, dopamine, prostaglandins and sodium play a role. Exogenously expressed CRTCs stimulate atp1b1 transcription. Evidence for a role of endogenous CRTCs includes the loss of transcriptional regulation of atp1b1 by a dominant negative CRTC, as well as by a CREB mutant, with an altered CRTC binding site. In a number of experimental systems, SIK phosphorylates CRTCs, which are then sequestered in the cytoplasm, preventing their nuclear effects. Consistent with such a role of SIK in primary RPT cells, atp1b1 transcription increased in the presence of a dominant negative SIK1, and in addition, regulation by dopamine, norepinephrine and monensin was disrupted by a dominant negative SIK1. These latter observations can be explained, if SIK1 is phosphorylated and inactivated in the presence of these renal effectors. Our results support the hypothesis that Na,K-ATPase in the renal proximal tubule is regulated at the transcriptional level via SIK1 and CRTCs by renal effectors, in addition to the previously reported control of the phosphorylation of Na,K-ATPase. PMID:26432356

  16. Gastrin decreases Na+,K+-ATPase activity via a PI 3-kinase- and PKC-dependent pathway in human renal proximal tubule cells.

    PubMed

    Liu, Tianbing; Konkalmatt, Prasad R; Yang, Yu; Jose, Pedro A

    2016-04-01

    The natriuretic effect of gastrin suggests a role in the coordinated regulation of sodium balance by the gastrointestinal tract and the kidney. The renal molecular targets and signal transduction pathways for such an effect of gastrin are largely unknown. Recently, we reported that gastrin induces NHE3 phosphorylation and internalization via phosphatidylinositol (PI) 3-kinase and PKCα. In this study, we show that gastrin induced the phosphorylation of human Na(+),K(+)-ATPase at serine 16, resulting in its endocytosis via Rab5 and Rab7 endosomes. The gastrin-stimulated phosphorylation of Na(+),K(+)-ATPase was dependent on PI 3-kinase because the phosphorylation was blocked by the PI 3-kinase inhibitor wortmannin. The phosphorylation of Na(+),K(+)-ATPase was also blocked by chelerythrine, a pan-PKC inhibitor, Gö-6976, a conventional PKC (cPKC) inhibitor, and BAPTA-AM, an intracellular calcium chelator, suggesting the importance of cPKC and intracellular calcium in the gastrin signaling pathway. The gastrin-mediated phosphorylation of Na(+),K(+)-ATPase was also inhibited by U-73122, a phospholipase C (PLC) inhibitor. These results suggest that gastrin regulates sodium hydrogen exchanger and pump in renal proximal tubule cells at the apical and basolateral membranes.

  17. Modulation of ouabain-insensitive Na(+)-ATPase activity in the renal proximal tubule by Mg(2+), MgATP and furosemide.

    PubMed

    Caruso-Neves, C; Coelho-Souza, S A; Vives, D; Goes, G; Lara, L S; Lopes, A G

    2002-12-01

    In addition to the (Na(+)+K(+))ATPase another P-ATPase, the ouabain-insensitive Na(+)-ATPase has been observed in several tissues. In the present paper, the effects of ligands, such as Mg(2+), MgATP and furosemide on the Na(+)-ATPase and its modulation by pH were studied in the proximal renal tubule of pig. The principal kinetics parameters of the Na(+)-ATPase at pH 7.0 are: (a) K(0.5) for Na(+)=8.9+/-2.2mM; (b) K(0.5) for MgATP=1.8+/-0.4mM; (c) two sites for free Mg(2+): one stimulatory (K(0.5)=0.20+/-0.06 mM) and other inhibitory (I(0.5)=1.1+/-0.4 mM); and (d) I(0.5) for furosemide=1.1+/-0.2 mM. Acidification of the reaction medium to pH 6.2 decreases the apparent affinity for Na(+) (K(0.5)=19.5+/-0.4) and MgATP (K(0.5)=3.4+/-0.3 mM) but increases the apparent affinity for furosemide (0.18+/-0.02 mM) and Mg(2+) (0.05+/-0.02 mM). Alkalization of the reaction medium to pH 7.8 decreases the apparent affinity for Na(+) (K(0.5)=18.7+/-1.5 mM) and furosemide (I(0.5)=3.04+/-0.57 mM) but does not change the apparent affinity to MgATP and Mg(2+). The data presented in this paper indicate that the modulation of the Na(+)-ATPase by pH is the result of different modifications in several steps of its catalytical cycle. Furthermore, they suggest that changes in the concentration of natural ligands such as Mg(2+) and MgATP complex may play an important role in the Na(+)-ATPase physiological regulatory mechanisms.

  18. The carbohydrate moieties of the beta-subunit of Na+, K(+)-ATPase: their lateral motions and proximity to the cardiac glycoside site.

    PubMed Central

    Amler, E; Abbott, A; Malak, H; Lakowicz, J; Ball, W J

    1996-01-01

    The beta-subunit associated with the catalytic (alpha) subunit of the mammalian Na+, K(+) -ATPase is a transmembrane glycoprotein with three extracellularly located N-glycosylation sites. Although beta appears to be essential for a functional enzyme, the role of beta and its sugars remains unknown. In these studies, steady-state and dynamic fluorescence measurements of the fluorophore lucifer yellow (LY) covalently linked to the carbohydrate chains of beta have demonstrated that the bound probes are highly solvent exposed but restricted in their diffusional motions. Furthermore, the probes' environments on beta were not altered by Na+ or K+ or ouabain-induced enzyme conformational changes, but both divalent cation and oligomycin addition evoked modest changes in LY fluorescence. Frequency domain measurements reflecting the Förster fluorescence energy transfer (FET) occurring between anthroylouabain (AO) bound to the cardiac glycoside receptor site on alpha and the carbohydrate-linked LY demonstrated their close proximity (18 A). Additional FET determinations made between LY as donor and erythrosin-5-isothiocyanate, covalently bound at the enzyme's putative ATP binding site domain, indicated that a distance of about 85 A separates these two regions and that this distance is reduced upon divalent cation binding and increased upon the Na+E1-->K+E2 conformational transition. These data suggest a model for the localization of the terminal moieties of the oligosaccharides that places them, on average, about 18 A from the AO binding site and this distance or less from the extracellular membrane surface. Images FIGURE 5 PMID:8770197

  19. Proximal Nephron

    PubMed Central

    Zhuo, Jia L.; Li, Xiao C.

    2013-01-01

    The kidney plays a fundamental role in maintaining body salt and fluid balance and blood pressure homeostasis through the actions of its proximal and distal tubular segments of nephrons. However, proximal tubules are well recognized to exert a more prominent role than distal counterparts. Proximal tubules are responsible for reabsorbing approximately 65% of filtered load and most, if not all, of filtered amino acids, glucose, solutes, and low molecular weight proteins. Proximal tubules also play a key role in regulating acid-base balance by reabsorbing approximately 80% of filtered bicarbonate. The purpose of this review article is to provide a comprehensive overview of new insights and perspectives into current understanding of proximal tubules of nephrons, with an emphasis on the ultrastructure, molecular biology, cellular and integrative physiology, and the underlying signaling transduction mechanisms. The review is divided into three closely related sections. The first section focuses on the classification of nephrons and recent perspectives on the potential role of nephron numbers in human health and diseases. The second section reviews recent research on the structural and biochemical basis of proximal tubular function. The final section provides a comprehensive overview of new insights and perspectives in the physiological regulation of proximal tubular transport by vasoactive hormones. In the latter section, attention is particularly paid to new insights and perspectives learnt from recent cloning of transporters, development of transgenic animals with knockout or knockin of a particular gene of interest, and mapping of signaling pathways using microarrays and/or physiological proteomic approaches. PMID:23897681

  20. Role of H{sub 2}O{sub 2} on the kinetics of low-affinity high-capacity Na{sup +}-dependent alanine transport in SHR proximal tubular epithelial cells

    SciTech Connect

    Pinto, Vanda; Pinho, Maria Joao; Jose, Pedro A.; Soares-da-Silva, Patricio

    2010-07-30

    Research highlights: {yields} H{sub 2}O{sub 2} in excess is required for the presence of a low-affinity high-capacity component for the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake in SHR PTE cells only. {yields} It is suggested that Na{sup +} binding in renal ASCT2 may be regulated by ROS in SHR PTE cells. -- Abstract: The presence of high and low sodium affinity states for the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake in immortalized renal proximal tubular epithelial (PTE) cells was previously reported (Am. J. Physiol. 293 (2007) R538-R547). This study evaluated the role of H{sub 2}O{sub 2} on the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake of ASCT2 in immortalized renal PTE cells from Wistar Kyoto rat (WKY) and spontaneously hypertensive rat (SHR). Na{sup +} dependence of [{sup 14}C]-L-alanine uptake was investigated replacing NaCl with an equimolar concentration of choline chloride in vehicle- and apocynin-treated cells. Na{sup +} removal from the uptake solution abolished transport activity in both WKY and SHR PTE cells. Decreases in H{sub 2}O{sub 2} levels in the extracellular medium significantly reduced Na{sup +}-K{sub m} and V{sub max} values of the low-affinity high-capacity component in SHR PTE cells, with no effect on the high-affinity low-capacity state of the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake. After removal of apocynin from the culture medium, H{sub 2}O{sub 2} levels returned to basal values within 1 to 3 h in both WKY and SHR PTE cells and these were found stable for the next 24 h. Under these experimental conditions, the Na{sup +}-K{sub m} and V{sub max} of the high-affinity low-capacity state were unaffected and the low-affinity high-capacity component remained significantly decreased 1 day but not 4 days after apocynin removal. In conclusion, H{sub 2}O{sub 2} in excess is required for the presence of a low-affinity high-capacity component for the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake in SHR PTE cells only

  1. Proximity fuze

    DOEpatents

    Harrison, Thomas R.

    1989-08-22

    A proximity fuze system includes an optical ranging apparatus, a detonation circuit controlled by the optical ranging apparatus, and an explosive charge detonated by the detonation cirtcuit. The optical ranging apparatus includes a pulsed laser light source for generating target ranging light pulses and optical reference light pulses. A single lens directs ranging pulses to a target and collects reflected light from the target. An optical fiber bundle is used for delaying the optical reference pulses to correspond to a predetermined distance from the target. The optical ranging apparatus includes circuitry for providing a first signal depending upon the light pulses reflected from the target, a second signal depending upon the light pulses from the optical delay fiber bundle, and an output signal when the first and second signals coincide with each other. The output signal occurs when the distance from the target is equal to the predetermined distance form the target. Additional circuitry distinguishes pulses reflected from the target from background solar radiation.

  2. Proximity fuze

    DOEpatents

    Harrison, T.R.

    1987-07-10

    A proximity fuze system includes an optical ranging apparatus, a detonation circuit controlled by the optical ranging apparatus, and an explosive charge detonated by the detonation circuit. The optical ranging apparatus includes a pulsed laser light source for generating target ranging light pulses and optical reference light pulses. A single lens directs ranging pulses to a target and collects reflected light from the target. An optical fiber bundle is used for delaying the optical reference pulses to correspond to a predetermined distance from the target. The optical ranging apparatus includes circuitry for providing a first signal depending upon the light pulses reflected from the target, a second signal depending upon the light pulses from the optical delay fiber bundle, and an output signal when the first and second signals coincide with each other. The output signal occurs when the distance from the target is equal to the predetermined distance from the target. Additional circuitry distinguishes pulses reflected from the target from background solar radiation. 3 figs.

  3. Proximity fuze

    SciTech Connect

    Harrison, T.R.

    1989-08-22

    A proximity fuze system is described. It includes an optical ranging apparatus, a detonation circuit controlled by the optical ranging apparatus, and an explosive charge detonated by the detonation circuit. The optical ranging apparatus includes a pulsed laser light source for generating target ranging light pulses and optical reference light pulses. A single lens directs ranging pulses to a target and collects reflected light from the target. An optical fiber bundle is used for delaying the optical reference pulses to correspond to a predetermined distance from the target. The optical ranging apparatus includes circuitry for providing a first signal depending upon the light pulses reflected from the target, a second signal depending upon the light pulses from the optical delay fiber bundle, and an output signal when the first and second signals coincide with each other. The output signal occurs when the distance from the target is equal to the predetermined distance from the target. Additional circuitry distinguishes pulses reflected from the target from background solar radiation.

  4. The angiotensin receptor type 1-Gq protein-phosphatidyl inositol phospholipase Cbeta-protein kinase C pathway is involved in activation of proximal tubule Na+-ATPase activity by angiotensin(1-7) in pig kidneys.

    PubMed

    Lara, Lucienne S; Correa, Juliana S; Lavelle, Anouchka B; Lopes, Anibal G; Caruso-Neves, Celso

    2008-05-01

    In a previous study, we observed that angiotensin(1-7) (Ang(1-7)) stimulates proximal tubule Na+-ATPase activity through the angiotensin receptor type 1 (AT1R). Here we aimed to study the signalling pathways involved. Our results show that the stimulatory effect of Ang(1-7) on Na+-ATPase activity through AT1R involves a Gq protein-phosphatidyl inositol-phospholipase Cbeta (PI-PLCbeta) pathway because: (1) the effect was reversed by GDPbetaS, a non-hydrolysable GDP analogue, and by a monoclonal Gq protein antibody; (2) the effect was similar and not additive to that of GTPgammaS, a non-hydrolysable GTP analogue; (3) Ang(1-7) induced a rapid decrease (30 s) in phosphatidylinositol 4,5-bisphosphate levels, a PI-PLCbeta substrate; and (4) U73122, a specific inhibitor of PI-PLCbeta, abolished Ang(1-7)-induced stimulation of Na+-ATPase activity. Angiotensin(1-7) increased the protein kinase C (PKC) activity similarly to phorbol-12-myristate-13-acetate (PMA), an activator of PKC. This effect was reversed by losartan, a specific antagonist of AT1R. The stimulatory effects of Ang(1-7) and PMA on Na+-ATPase activity are similar, non-additive and reversed by calphostin C, a specific inhibitor of PKC. A catalytic subunit of PKC (PKC-M) increased the Na+-ATPase activity. These data show that Ang(1-7) stimulates Na+-ATPase activity through the AT1R-Gq protein-PI-PLCbeta-PKC pathway. This effect is similar to that described for angiotensin II, showing for the first time that these compounds could have similar effects in the renal system.

  5. HCO3−-independent conductance with a mutant Na+/HCO3− cotransporter (SLC4A4) in a case of proximal renal tubular acidosis with hypokalaemic paralysis

    PubMed Central

    Parker, Mark D; Qin, Xue; Williamson, Rosalind C; Toye, Ashley M; Boron, Walter F

    2012-01-01

    The renal electrogenic Na+/HCO3− cotransporter (NBCe1-A) contributes to the basolateral step of transepithelial HCO3− reabsorption in proximal tubule epithelia, contributing to the buffering of blood pH. Elsewhere in the body (e.g. muscle cells) NBCe1 variants contribute to, amongst other processes, maintenance of intracellular pH. Others have described a homozygous mutation in NBCe1 (NBCe1-A p.Ala799Val) in an individual with severe proximal renal tubular acidosis (pRTA; usually associated with defective HCO3− reabsorption in proximal tubule cells) and hypokalaemic periodic paralysis (hypoPP; usually associated with leaky cation channels in muscle cells). Using biotinylation and two-electrode voltage-clamp on Xenopus oocytes expressing NBCe1, we demonstrate that the mutant NBCe1-A (AA799V) exhibits a per-molecule transport defect that probably contributes towards the observed pRTA. Furthermore, we find that AA799V expression is associated with an unusual HCO3−-independent conductance that, if associated with mutant NBCe1 in muscle cells, could contribute towards the appearance of hypokalaemic paralysis in the affected individual. We also study three novel lab mutants of NBCe1-A: p.Ala799Ile, p.Ala799Gly and p.Ala799Ser. All three exhibit a per-molecule transport defect, but only AA799I exhibits an AA799V-like ion conductance. AA799G and AA799S exhibit unusual outward rectification in their HCO3−-dependent conductance and AA799G exhibits reduced sensitivity to both DIDS and tenidap. A799G is the first mutation shown to affect the apparent tenidap affinity of NBCe1. Finally we show that AA799V and AA799I, which accumulate poorly in the plasma membrane of oocytes, exhibit signs of abnormal intracellular accumulation in a non-polarized renal cell-line. PMID:22331414

  6. Proteinases inhibit H(+)-ATPase and Na+/H+ exchange but not water transport in apical and endosomal membranes from rat proximal tubule.

    PubMed

    Sabolić, I; Shi, L B; Brown, D; Ausiello, D A; Verkman, A S

    1992-01-10

    A marked increase in water permeability can be induced in Xenopus oocytes by injection of mRNA from tissues that express water channels, suggesting that the water channel is a protein. In view of this and previous reports which showed that proteinases may interfere with mercurial inhibition of water transport in red blood cells (RBC), we examined the influence of trypsin, chymotrypsin, papain, pronase, subtilisin and thermolysin on water permeability as well as on ATPase activity, H(+)-pump, passive H+ conductance, and Na+/H+ exchange in apical brush-border vesicles (BBMV) and endosomal (EV) vesicles from rat renal cortex. H+ transport was measured by Acridine orange fluorescence quenching and water transport by stopped-flow light scattering. As measured by potential-driven H+ accumulation in BBMV and EV, proteinase treatment had little effect on vesicle integrity. In BBMV, ecto-ATPase activity was inhibited by 15-30%, Na+/H+ exchange by 20-55%, and H+ conductance was unchanged. Osmotic water permeability (Pf) was 570 microns/s and was inhibited 85-90% by 0.6 mM HgCl2; proteinase treatment did not affect Pf or the HgCl2 inhibition. In EV, NEM-sensitive H+ accumulation and ATPase activity were inhibited by greater than 95%. Pf (140 microns/s) and HgCl2 inhibition (75-85%) were not influenced by proteinase treatment. SDS-PAGE showed selective digestion of multiple polypeptides by proteinases. These results confirm the presence of water channels in BBMV and EV and demonstrate selective inhibition of ATPase function and Na+/H+ exchange by proteinase digestion. The lack of effect of proteinases on water transport by mercurials. We conclude that the water channel may be a small integral membrane protein which, unlike the H(+)-ATPase and Na+/H+ exchanger, has no functionally important membrane domains that are sensitive to proteolysis.

  7. Proximal Tibial Bone Graft

    MedlinePlus

    ... All Site Content AOFAS / FootCareMD / Treatments Proximal Tibial Bone Graft Page Content What is a bone graft? Bone grafts may be needed for various ... the proximal tibia. What is a proximal tibial bone graft? Proximal tibial bone graft (PTBG) is a ...

  8. Proximal humerus fractures.

    PubMed

    Price, Matthew C; Horn, Pamela L; Latshaw, James C

    2013-01-01

    Proximal humerus fractures are among the most common fractures associated with osteoporosis. With an aging population, incidence of these fractures will only increase. The proximal humerus not only forms the lateral portion of the shoulder articulation but also has significant associations with musculoskeletal and neurovascular structures. As a result, fractures of the proximal humerus can significantly impact not only the function of the shoulder joint, but the health and function of the entire upper extremity as well. Understanding of these fractures, the management options, and associated nursing care, can help reduce morbidity rate and improve functional outcomes.

  9. Two-Dimensional Optical Proximity Effects

    NASA Astrophysics Data System (ADS)

    Flanner, Philip D.; Subramanian, Shankar; Neureuther, Andrew R.

    1986-08-01

    In projection printing the proximity effects between adjacent two-dimensional features such as concentric elbows can be the limiting factor in designing layout rules. An aerial image simulation code based on the imaging algorithms in SAMPLE has been developed and used to investigate these proximity effects. The program accepts arbitrary polygonal shapes constructed of rectangular and triangular patches. The image is calculated using Hopkins transmission cross coefficient formulation and uses rapid integral evaluation techniques. The cpu time for this FORTRAN F77 program depends on the size of the mask and the partial coherence factor as 0.25[(1 + σ) 2A(NA/λ)2]2 seconds on a DEC VAX 11/780 using double precision, where A is the mask area, σ the coherence factor, NA the numerical aperture and λ the wavelength. The output intensity can be displayed with graphics tools such as UNIGRAFIX or cross-sectioned for input to SAMPLE development simulation along critical paths. Proximity effects in critical regions between features such as nested elbows, contacts near contacts and lines, and lines near large pads are studied. For small contacts studies show that a contact hole can be placed as close as 0.5λ/NA microns to another contact hole. For nested elbows the critical effect is the variation in intensity in the straight regions just adjacent to the corner. This undesirable variation is primarily due to the intrafeature intensity interactions and is not greatly influenced by the proximity of another nested elbow. For general feature shapes the proximity effects are reduced by increasing the partial coherence factor to 0.5 or higher but at the cost of reducing contrast and peak intensity. For contact masks a partial coherence of 0.3 is recommended for higher edge slope and peak intensities. Proximity effects of small defects are also illustrated.

  10. Capacitive proximity sensor

    DOEpatents

    Kronberg, J.W.

    1994-05-31

    A proximity sensor based on a closed field circuit is disclosed. The circuit comprises a ring oscillator using a symmetrical array of plates that creates an oscillating displacement current. The displacement current varies as a function of the proximity of objects to the plate array. Preferably the plates are in the form of a group of three pair of symmetric plates having a common center, arranged in a hexagonal pattern with opposing plates linked as a pair. The sensor produces logic level pulses suitable for interfacing with a computer or process controller. The proximity sensor can be incorporated into a load cell, a differential pressure gauge, or a device for measuring the consistency of a characteristic of a material where a variation in the consistency causes the dielectric constant of the material to change. 14 figs.

  11. Capacitive proximity sensor

    DOEpatents

    Kronberg, James W.

    1994-01-01

    A proximity sensor based on a closed field circuit. The circuit comprises a ring oscillator using a symmetrical array of plates that creates an oscillating displacement current. The displacement current varies as a function of the proximity of objects to the plate array. Preferably the plates are in the form of a group of three pair of symmetric plates having a common center, arranged in a hexagonal pattern with opposing plates linked as a pair. The sensor produces logic level pulses suitable for interfacing with a computer or process controller. The proximity sensor can be incorporated into a load cell, a differential pressure gauge, or a device for measuring the consistency of a characteristic of a material where a variation in the consistency causes the dielectric constant of the material to change.

  12. Proximal Hamstring Repair Strength

    PubMed Central

    Harvey, Margaret Ann; Singh, Hardeep; Obopilwe, Elifho; Charette, Ryan; Miller, Suzanne

    2015-01-01

    Background: Proximal hamstring repair for complete ruptures has become a common treatment. There is no consensus in the literature about postoperative rehabilitation protocols following proximal hamstring repair. Some protocols describe bracing to prevent hip flexion or knee extension while others describe no immobilization. There are currently no biomechanical studies evaluating proximal hamstring repairs; nor are there any studies evaluating the effect of different hip flexion angles on these repairs. Hypothesis: As hip flexion increases from 0° to 90°, there will be a greater gap with cyclical loading. Study Design: Controlled laboratory study. Methods: Proximal hamstring insertions were detached from the ischial tuberosity in 24 cadavers and were repaired with 3 single-loaded suture anchors in the hamstring footprint with a Krakow suture technique. Cyclic loading from 10 to 125 N at 1 Hz was then performed for 0°, 45°, and 90° of hip flexion for 1500 cycles. Gap formation, stiffness, yield load, ultimate load, and energy to ultimate load were compared between groups using paired t tests. Results: Cyclic loading demonstrated the least amount of gap formation (P < .05) at 0° of hip flexion (2.39 mm) and most at 90° of hip flexion (4.19 mm). There was no significant difference in ultimate load between hip flexion angles (326, 309, and 338 N at 0°, 45°, and 90°, respectively). The most common mode of failure occurred with knot/suture failure (n = 17). Conclusion: Increasing hip flexion from 0° to 90° increases the displacement across proximal hamstring repairs. Postoperative bracing that limits hip flexion should be considered. Clinical Relevance: Repetitive motion involving hip flexion after a proximal hamstring repair may cause compromise of the repair. PMID:26665049

  13. Traumatic proximal tibiofibular dislocation.

    PubMed

    Burgos, J; Alvarez-Montero, R; Gonzalez-Herranz, P; Rapariz, J M

    1997-01-01

    Proximal tibiofibular dislocation is an exceptional lesion. Rarer still is its presentation in childhood. We describe the clinical case of a 6-year-old boy, the victim of a road accident. He had a tibiofibular dislocation associated with a metaphyseal fracture of the tibia.

  14. Steerable Capacitive Proximity Sensor

    NASA Technical Reports Server (NTRS)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Steerable capacitive proximity sensor of "capaciflector" type based partly on sensing units described in GSC-13377 and GSC-13475. Position of maximum sensitivity adjusted without moving sensor. Voltage of each driven shield adjusted separately to concentrate sensing electric field more toward one side or other.

  15. Proximate Analysis of Coal

    ERIC Educational Resources Information Center

    Donahue, Craig J.; Rais, Elizabeth A.

    2009-01-01

    This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter,…

  16. Subacute diabetic proximal neuropathy

    NASA Technical Reports Server (NTRS)

    Pascoe, M. K.; Low, P. A.; Windebank, A. J.; Litchy, W. J.

    1997-01-01

    OBJECTIVE: To evaluate the clinical, electrophysiologic, autonomic, and neuropathologic characteristics and the natural history of subacute diabetic proximal neuropathy and its response to immunotherapy. MATERIAL AND METHODS: For the 12-year period from 1983 to 1995, we conducted a retrospective review of medical records of Mayo Clinic patients with diabetes who had subacute onset and progression of proximal weakness. The responses of treated versus untreated patients were compared statistically. RESULTS: During the designated study period, 44 patients with subacute diabetic proximal neuropathy were encountered. Most patients were middle-aged or elderly, and no sex preponderance was noted. The proximal muscle weakness often was associated with reduced or absent lower extremity reflexes. Associated weight loss was a common finding. Frequently, patients had some evidence of demyelination on nerve conduction studies, but it invariably was accompanied by concomitant axonal degeneration. The cerebrospinal fluid protein concentration was usually increased. Diffuse and substantial autonomic failure was generally present. In most cases, a sural nerve biopsy specimen suggested demyelination, although evidence of an inflammatory infiltrate was less common. Of 12 patients who received treatment (with prednisone, intravenous immune globulin, or plasma exchange), 9 had improvement of their conditions, but 17 of 29 untreated patients (59%) with follow-up also eventually had improvement, albeit at a much slower rate. Improvement was usually incomplete. CONCLUSION: We suggest that the entity of subacute diabetic proximal neuropathy is an extensive and severe variant of bilateral lumbosacral radiculoplexopathy, with some features suggestive of an immune-mediated cause. It differs from chronic inflammatory demyelinating polyradiculoneuropathy in that most cases have a more restricted distribution and seem to be monophasic and self-limiting. The efficacy of immunotherapy is unproved

  17. Proximity Networks and Epidemics

    NASA Astrophysics Data System (ADS)

    Guclu, Hasan; Toroczkai, Zoltán

    2007-03-01

    We presented the basis of a framework to account for the dynamics of contacts in epidemic processes, through the notion of dynamic proximity graphs. By varying the integration time-parameter T, which is the period of infectivity one can give a simple account for some of the differences in the observed contact networks for different diseases, such as smallpox, or AIDS. Our simplistic model also seems to shed some light on the shape of the degree distribution of the measured people-people contact network from the EPISIM data. We certainly do not claim that the simplistic graph integration model above is a good model for dynamic contact graphs. It only contains the essential ingredients for such processes to produce a qualitative agreement with some observations. We expect that further refinements and extensions to this picture, in particular deriving the link-probabilities in the dynamic proximity graph from more realistic contact dynamics should improve the agreement between models and data.

  18. Echosonography with proximity sensors

    NASA Astrophysics Data System (ADS)

    Thaisiam, W.; Laithong, T.; Meekhun, S.; Chaiwathyothin, N.; Thanlarp, P.; Danworaphong, S.

    2013-03-01

    We propose the use of a commercial ultrasonic proximity sensor kit for profiling an altitude-varying surface by employing echosonography. The proximity sensor kit, two identical transducers together with its dedicated operating circuit, is used as a profiler for the construction of an image. Ultrasonic pulses are emitted from one of the transducers and received by the other. The time duration between the pulses allows us to determine the traveling distance of each pulse. In the experiment, the circuit is used with the addition of two copper wires for directing the outgoing and incoming signals to an oscilloscope. The time of flight of ultrasonic pulses can thus be determined. Square grids of 5 × 5 cm2 are made from fishing lines, forming pixels in the image. The grids are designed to hold the detection unit in place, about 30 cm above a flat surface. The surface to be imaged is constructed to be height varying and placed on the flat surface underneath the grids. Our result shows that an image of the profiled surface can be created by varying the location of the detection unit along the grid. We also investigate the deviation in relation to the time of flight of the ultrasonic pulse. Such an experiment should be valuable for conveying the concept of ultrasonic imaging to physical and medical science undergraduate students. Due to its simplicity, the setup could be made in any undergraduate laboratory relatively inexpensively and it requires no complex parts. The results illustrate the concept of echosonography.

  19. Analysis of standing droplets in rat proximal tubules

    PubMed Central

    1982-01-01

    Volume, osmolality, and concentrations for Na, Cl, and raffinose have been measured as a function of time in standing droplets within rat intermediate and late proximal tubules. Standing droplet reabsorption proceeds without the development of a measurable osmotic difference across the epithelium. After 140 s of tubular exposure, droplet-to- plasma concentration differences are observed for raffinose, Na, and Cl with the observed Na concentration difference, usually referred to as limiting gradient, being approximately 9 mM. It is possible that a smaller or even no limiting difference would be attained with longer exposure times. Previous values measured for the limiting Na concentration in the rat proximal tubule were determined before the attainment of constant concentrations. Assuming that the Na concentration we measured is the limiting value, we estimate that active NaCl transport accounts for a very small fraction, less than 6%, of the volume reabsorption; using an alternative approach of fitting a theoretical model to our experimental data, active NaCl transport is again estimated to account for only 6% of the total reabsorbate. The previous interpretation that a limiting Na concentration gradient constitutes the most direct evidence for active Na transport may be in error; the gradient we measure can be modeled without incorporating active NaCl transport. PMID:7069399

  20. Isosmotic volume reabsorption in rat proximal tubule

    PubMed Central

    1980-01-01

    A theoretical model incorporation both active and passive forces has been developed for fluid reabsorption from split oil droplets in rat intermediate and late proximal tubule. Of necessity, simplifying assumptions have been introduced; we have assumed that the epithelium can be treated as a single membrane and that the membrane "effective" HCO3 permeability is near zero. Based on this model with its underlying assumptions, the following conclusions are drawn. Regardless of the presence or absence of active NaCl transport, fluid reabsorption from the split oil droplet is isosmotic. The reabsorbate osmolarity can be affected by changes in tubular permeability parameters and applied forces but is not readily altered from an osmolarity essentially equal to that of plasma. In a split droplet, isosmotic flow need not be a special consequence of active Na transport, is not the result of a particular set of permeability properties, and is not merely a trivial consequence of a very high hydraulic conductivity; isosmotic flow can be obtained with hydraulic conductivity nearly an order of magnitude lower than that previously measured in the rat proximal convoluted tubule. Isosmotic reabsorption is, in part, the result of the interdependence of salt and water flows, their changing in parallel, and thus their ratio, the reabsorbate concentration being relatively invariant. Active NaCl transport can cause osmotic water flow by reducing the luminal fluid osmolarity. In the presence of passive forces the luminal fluid can be hypertonic to plasma, and active NaCl transport can still exert its osmotic effect on volume flow. There are two passive forces for volume flow: the Cl gradient and the difference in effective osmotic pressure; they have an approximately equivalent effect on volume flow. Experimentally, we have measured volume changes in a droplet made hyperosmotic by the addition of 50 mM NaCl; the experimental results are predicted reasonably well by our theoretical model

  1. Isosmotic volume reabsorption in rat proximal tubule.

    PubMed

    Warner, R R; Lechene, C

    1980-11-01

    A theoretical model incorporation both active and passive forces has been developed for fluid reabsorption from split oil droplets in rat intermediate and late proximal tubule. Of necessity, simplifying assumptions have been introduced; we have assumed that the epithelium can be treated as a single membrane and that the membrane "effective" HCO3 permeability is near zero. Based on this model with its underlying assumptions, the following conclusions are drawn. Regardless of the presence or absence of active NaCl transport, fluid reabsorption from the split oil droplet is isosmotic. The reabsorbate osmolarity can be affected by changes in tubular permeability parameters and applied forces but is not readily altered from an osmolarity essentially equal to that of plasma. In a split droplet, isosmotic flow need not be a special consequence of active Na transport, is not the result of a particular set of permeability properties, and is not merely a trivial consequence of a very high hydraulic conductivity; isosmotic flow can be obtained with hydraulic conductivity nearly an order of magnitude lower than that previously measured in the rat proximal convoluted tubule. Isosmotic reabsorption is, in part, the result of the interdependence of salt and water flows, their changing in parallel, and thus their ratio, the reabsorbate concentration being relatively invariant. Active NaCl transport can cause osmotic water flow by reducing the luminal fluid osmolarity. In the presence of passive forces the luminal fluid can be hypertonic to plasma, and active NaCl transport can still exert its osmotic effect on volume flow. There are two passive forces for volume flow: the Cl gradient and the difference in effective osmotic pressure; they have an approximately equivalent effect on volume flow. Experimentally, we have measured volume changes in a droplet made hyperosmotic by the addition of 50 mM NaCl; the experimental results are predicted reasonably well by our theoretical model.

  2. Some Properties of Fuzzy Soft Proximity Spaces

    PubMed Central

    Demir, İzzettin; Özbakır, Oya Bedre

    2015-01-01

    We study the fuzzy soft proximity spaces in Katsaras's sense. First, we show how a fuzzy soft topology is derived from a fuzzy soft proximity. Also, we define the notion of fuzzy soft δ-neighborhood in the fuzzy soft proximity space which offers an alternative approach to the study of fuzzy soft proximity spaces. Later, we obtain the initial fuzzy soft proximity determined by a family of fuzzy soft proximities. Finally, we investigate relationship between fuzzy soft proximities and proximities. PMID:25793224

  3. Some properties of fuzzy soft proximity spaces.

    PubMed

    Demir, İzzettin; Özbakır, Oya Bedre

    2015-01-01

    We study the fuzzy soft proximity spaces in Katsaras's sense. First, we show how a fuzzy soft topology is derived from a fuzzy soft proximity. Also, we define the notion of fuzzy soft δ-neighborhood in the fuzzy soft proximity space which offers an alternative approach to the study of fuzzy soft proximity spaces. Later, we obtain the initial fuzzy soft proximity determined by a family of fuzzy soft proximities. Finally, we investigate relationship between fuzzy soft proximities and proximities.

  4. Regulation of glomerulotubular balance: flow-activated proximal tubule function.

    PubMed

    Wang, Tong; Weinbaum, Sheldon; Weinstein, Alan M

    2017-03-07

    The purpose of this review is to summarize our knowledge and understanding of the physiological importance and the mechanisms underlying flow-activated proximal tubule transport. Since the earliest micropuncture studies of mammalian proximal tubule, it has been recognized that tubular flow is an important regulator of sodium, potassium, and acid-base transport in the kidney. Increased fluid flow stimulates Na(+) and HCO3(-) absorption in the proximal tubule via stimulation of Na/H-exchanger isoform 3 (NHE3) and H(+)-ATPase. In the proximal tubule, brush border microvilli are the major flow sensors, which experience changes in hydrodynamic drag and bending moment as luminal flow velocity changes and which transmit the force of altered flow to cytoskeletal structures within the cell. The signal to NHE3 depends upon the integrity of the actin cytoskeleton; the signal to the H(+)-ATPase depends upon microtubules. We have demonstrated that alterations in fluid drag impact tubule function by modulating ion transporter availability within the brush border membrane of the proximal tubule. Beyond that, there is evidence that transporter activity within the peritubular membrane is also modulated by luminal flow. Secondary messengers that regulate the flow-mediated tubule function have also been delineated. Dopamine blunts the responsiveness of proximal tubule transporters to changes in luminal flow velocity, while a DA1 antagonist increases flow sensitivity of solute reabsorption. IP3 receptor-mediated intracellular Ca(2+) signaling is critical to transduction of microvillus drag. In this review, we summarize our findings of the regulatory mechanism of flow-mediated Na(+) and HCO3(-) transport in the proximal tubule and review available information about flow sensing and regulatory mechanism of glomerulotubular balance.

  5. Hirayama Disease with Proximal Involvement

    PubMed Central

    2016-01-01

    Hirayama disease is a slowly progressing benign motor neuron disease that affects the distal upper limb. A 29-year-old man visited the hospital with a 1-year history of weakened left proximal upper limb. He was diagnosed with Hirayama disease 9 years ago, while there was no further progression of the muscle weakness afterward. Atrophy and weakness was detected in proximal upper limb muscles. Magnetic resonance imaging and somatosensory evoked potentials were normal. Needle electromyography showed abnormal findings in proximal upper limb muscles. Our patient had Hirayama disease involving the proximal portion through secondary progression. Clinical manifestation and accurate electromyography may be useful for diagnosis. Rare cases with progression patterns as described here are helpful and have clinical meaning for clinicians. PMID:27550499

  6. Tools for proximal soil sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proximal soil sensing (i.e. near-surface geophysical methods) are used to study soil phenomena across spatial scales. Geophysical methods exploit contrasts in physical properties (dielectric permittivity, apparent electrical conductivity or resistivity, magnetic susceptibility) to indirectly measur...

  7. Cubesat Proximity Operations Demonstration (CPOD)

    NASA Technical Reports Server (NTRS)

    Villa, Marco; Martinez, Andres; Petro, Andrew

    2015-01-01

    The CubeSat Proximity Operations Demonstration (CPOD) project will demonstrate rendezvous, proximity operations and docking (RPOD) using two 3-unit (3U) CubeSats. Each CubeSat is a satellite with the dimensions 4 inches x 4 inches x 13 inches (10 centimeters x 10 centimeters x 33 centimeters) and weighing approximately 11 pounds (5 kilograms). This flight demonstration will validate and characterize many new miniature low-power proximity operations technologies applicable to future missions. This mission will advance the state of the art in nanosatellite attitude determination,navigation and control systems, in addition to demonstrating relative navigation capabilities.The two CPOD satellites are scheduled to be launched together to low-Earth orbit no earlier than Dec. 1, 2015.

  8. Driven shielding capacitive proximity sensor

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor); McConnell, Robert L. (Inventor)

    2000-01-01

    A capacitive proximity sensing element, backed by a reflector driven at the same voltage as and in phase with the sensor, is used to reflect the field lines away from a grounded robot arm towards an intruding object, thus dramatically increasing the sensor's range and sensitivity.

  9. Proximity Sensors Make Robot Dexterous

    NASA Technical Reports Server (NTRS)

    Hess, Cliff; Li, Larry C. H.

    1990-01-01

    Control system enables robot hand to grasp objects of varied shapes. Key features of system: reflective proximity sensors furnishing data on position, orientation, and distance of object and software protocol controlling sequence of operations in approaching and grasping objects. Reflected-beam sensing concept applied to simple opposed-jaw industrial grippers as well as to dexterous robot hands.

  10. Proximity and Anti-proximity effects in nanowires

    NASA Astrophysics Data System (ADS)

    Chan, Moses

    Near a superconductor/normal-metal interface, the leakage of Cooper pairs extends superconducting behavior into the metal. The spatial range of this proximity effect in a normal metal can be as long as 1 µm. However, when a ferromagnet is placed in contact with a superconductor, the Cooper pairs from the superconductor are not expected to survive beyond at most a few nanometers into the ferromagnet. Surprisingly we find when a cobalt nanowire as long as 600 nm is sandwiched between superconducting electrodes, it attains zero resistance at low temperature. For even longer wires, the transition to incomplete superconductivity via this (long range) proximity effect is foreshadowed by a large resistance peak (1). On the other hand when Zn nanowires of 40 nm diameter are contacted by superconducting electrodes, their superconductivity is unexpectedly suppressed (2). Worked supported by Penn State MRSEC.

  11. Micropower RF material proximity sensor

    DOEpatents

    McEwan, T.E.

    1998-11-10

    A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is disclosed. Thus, it can be used in corrosive environments, as well as in a wide variety of applications. An antenna has a characteristic impedance which depends on the materials in proximity to the antenna. An RF oscillator, which includes the antenna and is based on a single transistor in a Colpitt`s configuration, produces an oscillating signal. A detector is coupled to the oscillator which signals changes in the oscillating signal caused by changes in the materials in proximity to the antenna. The oscillator is turned on and off at a pulse repetition frequency with a low duty cycle to conserve power. The antenna consists of a straight monopole about one-quarter wavelength long at the nominal frequency of the oscillator. The antenna may be horizontally disposed on a container and very accurately detects the fill level within the container as the material inside the container reaches the level of the antenna. 5 figs.

  12. Micropower RF material proximity sensor

    DOEpatents

    McEwan, Thomas E.

    1998-01-01

    A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is of the sensor. Thus, it can be used in corrosive environments, as well as in a wide variety of applications. An antenna has a characteristic impedance which depends on the materials in proximity to the antenna. An RF oscillator, which includes the antenna and is based on a single transistor in a Colpitt's configuration, produces an oscillating signal. A detector is coupled to the oscillator which signals changes in the oscillating signal caused by changes in the materials in proximity to the antenna. The oscillator is turned on and off at a pulse repetition frequency with a low duty cycle to conserve power. The antenna consists of a straight monopole about one-quarter wavelength long at the nominal frequency of the oscillator. The antenna may be horizontally disposed on a container and very accurately detects the fill level within the container as the material inside the container reaches the level of the antenna.

  13. Proximate and polyphenolic characterization of cranberry pomace

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The proximate composition and identification and quantification of polyphenolic compounds in dried cranberry pomace were determined. Proximate analysis was conducted based on AOAC methods for moisture, protein, fat, and ash. Total carbohydrates were determined by the difference method. Polyphenolic ...

  14. Na+ recirculation and isosmotic transport.

    PubMed

    Larsen, E H; Møbjerg, N

    2006-01-01

    The Na(+) recirculation theory for solute-coupled fluid absorption is an expansion of the local osmosis concept introduced by Curran and analyzed by Diamond & Bossert. Based on studies on small intestine the theory assumes that the observed recirculation of Na(+) serves regulation of the osmolarity of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal NaCl by sucrose as well as the linear dependence of volume absorption on luminal NaCl concentration. Analysis of solvent drag on Na(+) in tight junctions provides explanation for the surprisingly high metabolic efficiency of Na(+) reabsorption. The model predicts and explains low metabolic efficiency in diluted external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and < or = 1 mOsm in proximal tubule. Truly isosmotic transport demands a Na(+) recirculation of 50-70% in small intestine but might be barely measurable in proximal tubule. The model fails to reproduce a certain type of observations: The reduced volume absorption at transepithelial osmotic equilibrium in AQP1 knockout mice, and the stimulated water absorption by gallbladder in diluted external solutions. Thus, it indicates cellular regulation of apical Na(+) uptake, which is not included in the mathematical treatment.

  15. Active Targets For Capacitive Proximity Sensors

    NASA Technical Reports Server (NTRS)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Lightweight, low-power active targets devised for use with improved capacitive proximity sensors described in "Capacitive Proximity Sensor Has Longer Range" (GSC-13377), and "Capacitive Proximity Sensors With Additional Driven Shields" (GSC-13475). Active targets are short-distance electrostatic beacons; they generate known alternating electro-static fields used for alignment and/or to measure distances.

  16. Modeling oxygen consumption in the proximal tubule: effects of NHE and SGLT2 inhibition

    PubMed Central

    Vallon, Volker; Edwards, Aurélie

    2015-01-01

    The objective of this study was to investigate how physiological, pharmacological, and pathological conditions that alter sodium reabsorption (TNa) in the proximal tubule affect oxygen consumption (QO2) and Na+ transport efficiency (TNa/QO2). To do so, we expanded a mathematical model of solute transport in the proximal tubule of the rat kidney. The model represents compliant S1, S2, and S3 segments and accounts for their specific apical and basolateral transporters. Sodium is reabsorbed transcellularly, via apical Na+/H+ exchangers (NHE) and Na+-glucose (SGLT) cotransporters, and paracellularly. Our results suggest that TNa/QO2 is 80% higher in S3 than in S1–S2 segments, due to the greater contribution of the passive paracellular pathway to TNa in the former segment. Inhibition of NHE or Na-K-ATPase reduced TNa and QO2, as well as Na+ transport efficiency. SGLT2 inhibition also reduced proximal tubular TNa but increased QO2; these effects were relatively more pronounced in the S3 vs. the S1–S2 segments. Diabetes increased TNa and QO2 and reduced TNa/QO2, owing mostly to hyperfiltration. Since SGLT2 inhibition lowers diabetic hyperfiltration, the net effect on TNa, QO2, and Na+ transport efficiency in the proximal tubule will largely depend on the individual extent to which glomerular filtration rate is lowered. PMID:25855513

  17. The HTV Proximity Communication System

    NASA Astrophysics Data System (ADS)

    Harada, Motoyuki; Takahashi, Tetsuo; Tanaka, Tetsuo

    2002-01-01

    National Space Development Agency of Japan (NASDA) is developing the H-II Transfer Vehicle (HTV) as an unmanned logistic support vehicle for the International Space Station (ISS). The HTV, which is launched by the H-IIA rocket, transports both pressurized and un-pressurized cargoes to the ISS, reloads disposal items from the ISS and performs destructive reentry over ocean area. NASDA plans the first flight of HTV in 2005 for demonstration. The HTV will contribute the ISS assembly and logistic re-supply operations with international commonality. For unmanned vehicle operation, communication link is critical with commanding and control, especially in proximity region to the ISS. As for the HTV operation, NASDA is developing dedicated communication system installed on the Japanese Experiment Module (JEM) of the ISS, which is called the Proximity Communication System (PROX). The HTV receives commands and transmits telemetry data through the PROX in its proximity operation to the ISS. To achieve this, the PROX can communicate with the HTV on its nominal trajectory within 23km of the ISS. Especially within 3km of the ISS, the PROX has capability to perform omni-directional communication to the HTV. The PROX also has GPS receiver and send GPS data to the HTV to support the HTV navigation for relative GPS navigation used in "far" range (500m away from the ISS). In addition to the above fundamental functions, the PROX has a capability of range and range-rate measurement between the ISS and the HTV by the pseudo noise (PN) code epoch and the Doppler shift frequency. This provides a reference data independent of "main" navigation methods (rendezvous sensor navigation or GPS navigation) of the HTV. The PROX also assists the ISS crew with its commanding device, called the Hardware Command Panel (HCP), to issue time-dependent safety-related critical commands for HTV berthing/un-berthing operation. When a failure occurs somewhere on "communication path" from the PROX Base Band

  18. Proximal Biceps in Overhead Athletes.

    PubMed

    Chalmers, Peter N; Verma, Nikhil N

    2016-01-01

    The proximal long head of the biceps tendon and its attachment at the superior glenoid tubercle and labrum are subject to a spectrum of disorders in overhead athletes. Biceps disorders are commonly characterized by intermittent anterior or deep-seated shoulder pain exacerbated by activity. Diagnosis is reached via various physical examination maneuvers; MRI can be uncertain. Nonsteroidal anti-inflammatory medications, targeted ultrasound-guided corticosteroid injections, and supervised physical therapy are the mainstays of nonoperative treatment. Operative treatment, which remains controversial, provides reliable pain relief, restoration of function for activities of daily living, and low complication rates, but return to play can be unpredictable.

  19. Protein Neighbors and Proximity Proteomics.

    PubMed

    Rees, Johanna S; Li, Xue-Wen; Perrett, Sarah; Lilley, Kathryn S; Jackson, Antony P

    2015-11-01

    Within cells, proteins can co-assemble into functionally integrated and spatially restricted multicomponent complexes. Often, the affinities between individual proteins are relatively weak, and proteins within such clusters may interact only indirectly with many of their other protein neighbors. This makes proteomic characterization difficult using methods such as immunoprecipitation or cross-linking. Recently, several groups have described the use of enzyme-catalyzed proximity labeling reagents that covalently tag the neighbors of a targeted protein with a small molecule such as fluorescein or biotin. The modified proteins can then be isolated by standard pulldown methods and identified by mass spectrometry. Here we will describe the techniques as well as their similarities and differences. We discuss their applications both to study protein assemblies and to provide a new way for characterizing organelle proteomes. We stress the importance of proteomic quantitation and independent target validation in such experiments. Furthermore, we suggest that there are biophysical and cell-biological principles that dictate the appropriateness of enzyme-catalyzed proximity labeling methods to address particular biological questions of interest.

  20. Fibrosis: ultimate and proximate causes

    PubMed Central

    Thannickal, Victor J.; Zhou, Yong; Gaggar, Amit; Duncan, Steven R.

    2014-01-01

    Fibrotic disorders account for an increasing burden of disease-associated morbidity and mortality worldwide. Although numerous risk factors have been recognized, the etiologies of many of these clinical syndromes have not been identified, and they are often termed idiopathic or cryptogenic. Here, we provide an evolutionary perspective on fibrosis aimed at elucidating its etiopathogenesis. By asking the ultimate question of “why” this process evolved in multicellular organisms, we hope to uncover proximate explanations for “how” it causes disease in humans. We posit that physiological fibrosis-like reactions evolved as an essential process in host defense against pathogens and in normal wound healing. Based on this premise, we reason that pathological fibrosis is related to one or more of the following: unidentified infectious or noninfectious antigens, autoimmunity, impaired regenerative responses, and the antagonistically pleiotropic action of genes involved in wound healing or development. The importance of genetic susceptibility, epigenetics, aging, and the modern-day environment are highlighted. Consideration of both ultimate and proximate causation goes beyond philosophical cogitations, as it will better inform pathobiological mechanisms of disease and aid in the prevention and treatment of fibrotic diseases. PMID:25365073

  1. Ash Aggregates in Proximal Settings

    NASA Astrophysics Data System (ADS)

    Porritt, L. A.; Russell, K.

    2012-12-01

    Ash aggregates are thought to have formed within and been deposited by the eruption column and plume and dilute density currents and their associated ash clouds. Moist, turbulent ash clouds are considered critical to ash aggregate formation by facilitating both collision and adhesion of particles. Consequently, they are most commonly found in distal deposits. Proximal deposits containing ash aggregates are less commonly observed but do occur. Here we describe two occurrences of vent proximal ash aggregate-rich deposits; the first within a kimberlite pipe where coated ash pellets and accretionary lapilli are found within the intra-vent sequence; and the second in a glaciovolcanic setting where cored pellets (armoured lapilli) occur within <1 km of the vent. The deposits within the A418 pipe, Diavik Diamond Mine, Canada, are the residual deposits within the conduit and vent of the volcano and are characterised by an abundance of ash aggregates. Coated ash pellets are dominant but are followed in abundance by ash pellets, accretionary lapilli and rare cored pellets. The coated ash pellets typically range from 1 - 5 mm in diameter and have core to rim ratios of approximately 10:1. The formation and preservation of these aggregates elucidates the style and nature of the explosive phase of kimberlite eruption at A418 (and other pipes?). First, these pyroclasts dictate the intensity of the kimberlite eruption; it must be energetic enough to cause intense fragmentation of the kimberlite to produce a substantial volume of very fine ash (<62 μm). Secondly, the ash aggregates indicate the involvement of moisture coupled with the presence of dilute expanded eruption clouds. The structure and distribution of these deposits throughout the kimberlite conduit demand that aggregation and deposition operate entirely within the confines of the vent; this indicates that aggregation is a rapid process. Ash aggregates within glaciovolcanic sequences are also rarely documented. The

  2. SGLT2 mediates glucose reabsorption in the early proximal tubule.

    PubMed

    Vallon, Volker; Platt, Kenneth A; Cunard, Robyn; Schroth, Jana; Whaley, Jean; Thomson, Scott C; Koepsell, Hermann; Rieg, Timo

    2011-01-01

    Mutations in the gene encoding for the Na(+)-glucose co-transporter SGLT2 (SLC5A2) associate with familial renal glucosuria, but the role of SGLT2 in the kidney is incompletely understood. Here, we determined the localization of SGLT2 in the mouse kidney and generated and characterized SGLT2-deficient mice. In wild-type (WT) mice, immunohistochemistry localized SGLT2 to the brush border membrane of the early proximal tubule. Sglt2(-/-) mice had glucosuria, polyuria, and increased food and fluid intake without differences in plasma glucose concentrations, GFR, or urinary excretion of other proximal tubular substrates (including amino acids) compared with WT mice. SGLT2 deficiency did not associate with volume depletion, suggested by similar body weight, BP, and hematocrit; however, plasma renin concentrations were modestly higher and plasma aldosterone levels were lower in Sglt2(-/-) mice. Whole-kidney clearance studies showed that fractional glucose reabsorption was significantly lower in Sglt2(-/-) mice compared with WT mice and varied in Sglt2(-/-) mice between 10 and 60%, inversely with the amount of filtered glucose. Free-flow micropuncture revealed that for early proximal collections, 78 ± 6% of the filtered glucose was reabsorbed in WT mice compared with no reabsorption in Sglt2(-/-) mice. For late proximal collections, fractional glucose reabsorption was 93 ± 1% in WT and 21 ± 6% in Sglt2(-/-) mice, respectively. These results demonstrate that SGLT2 mediates glucose reabsorption in the early proximal tubule and most of the glucose reabsorption by the kidney, overall. This mouse model mimics and explains the glucosuric phenotype of individuals carrying SLC5A2 mutations.

  3. CFTR mediated chloride secretion in the avian renal proximal tubule.

    PubMed

    Laverty, Gary; Anttila, Ashley; Carty, Jenava; Reddy, Varudhini; Yum, Jamie; Arnason, Sighvatur S

    2012-01-01

    In primary cell cultures of the avian (Gallus gallus) renal proximal tubule parathyroid hormone and cAMP activation generate a Cl(-)-dependent short circuit current (I(SC)) response, consistent with net transepithelial Cl(-) secretion. In this study we investigated the expression and physiological function of the Na-K-2Cl (NKCC) transporter and CFTR chloride channel, both associated with Cl(-) secretion in a variety of tissues, in these proximal tubule cells. Using both RT-PCR and immunoblotting approaches, we showed that NKCC and CFTR are expressed, both in proximal tubule primary cultures and in a proximal tubule fraction of non-cultured (native tissue) fragments. We also used electrophysiological methods to assess the functional contribution of NKCC and CFTR to forskolin-activated I(SC) responses in filter grown cultured monolayers. Bumetanide (10 μM), a specific blocker of NKCC, inhibited forskolin activated I(SC) by about 40%, suggesting that basolateral uptake of Cl(-) is partially mediated by NKCC transport. In monolayers permeabilized on the basolateral side with nystatin, forskolin activated an apical Cl(-) conductance, manifested as bidirectional diffusion currents in the presence of oppositely directed Cl(-) gradients. Under these conditions the apical conductance appeared to show some bias towards apical-to-basolateral Cl(-) current. Two selective CFTR blockers, CFTR Inhibitor 172 and GlyH-101 (both at 20 μM) inhibited the forskolin activated diffusion currents by 38-68%, with GlyH-101 having a greater effect. These data support the conclusion that avian renal proximal tubules utilize an apical CFTR Cl(-) channel to mediate cAMP-activated Cl(-) secretion.

  4. Deformed proximity potential for heavy ion reactions

    SciTech Connect

    Baltz, A.J.

    1989-09-01

    The proximity potential is discussed for the inelastic scattering of a spherical nucleus on a deformed nucleus or the mutual interaction of two deformed nuclei. It is shown that the proximity potential is, in general, geometrically more correct than the usual centerline prescription used in inelastic scattering analyses. For the cases where the proximity potential is inadequate a folding model approach is advocated. Techniques to facilitate the coupled channels analysis are presented. 11 refs., 6 figs.

  5. Prox-1 Automated Proximity Operations

    DTIC Science & Technology

    2016-01-13

    Operations FA9550-13-1-0218 Spencer, David A. Georgia Institute of Technology Atlanta, GA 30332-0150 GT-001 Air Force Office of Scientific Research 875...North Randolph St., Room 3112 Arlington, VA 22203 AFOSR DISTRIBUTION A N/A During 2015, the Prox-1 team completed a set of system-level tests focused...all spacecraft subsystems, including flight qualification of the following new technologies : the Honeybee Robotics Microsatellite CMG unit, the

  6. Isovolumetric regulation of renal proximal tubules in hypotonic medium.

    PubMed

    Lohr, J W

    1990-01-01

    Isolated nonperfused proximal tubules maintained their cell volume at a constant level (isovolumetric regulation, IVR), when osmolality of the bathing medium was gradually decreased from 290 to 190 mosm at 1.5 and 5.0 mosm/min. Hypotonic IVR was blocked by inhibiting the Na(+)-K+ pump with ouabain (10(-4) M) when osmolality was decreased at 1.5 or 5 mosm/min. Concentration-dependent inhibition of cell volume maintenance was observed in the presence of the K+ channel blocker barium (10(-3)-10(-2) M) when osmolality decreased at 5 mosm/min. Quinine (10(-3) M), another K+ channel blocker, also inhibited IVR at osmolality decreases of 1.5 and 5 mosm/min. These results suggest that the maintenance of constant cell volume during gradual hypoosmotic exposure involves mechanisms that depend on intact Na-K-ATPase and the controlled loss of intracellular K+.

  7. Range gated strip proximity sensor

    DOEpatents

    McEwan, T.E.

    1996-12-03

    A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance. 6 figs.

  8. Proximal Priority Laser Therapy: PPLT

    NASA Astrophysics Data System (ADS)

    Ohshiro, Toshio

    2004-09-01

    The author has, in the past, classified treatment methods for pain geometrically as point, line, two-dimensional, three-dimensional treatment and has used these over the years. However as a practitioner of western medicine, the author originally treated pain only directed at the painful site, and encountered cases where local treatment did not suffice. The author proved with SPECT and the Rand Phantom that treating the neck which is the midpoint of the brain, the center of the nervous system and the heart, the center of circulation, increased cerebral blood flow and also that laser emitted to neck will reach the spinal chord no matter from where on the neck the laser is emitted. From such research and 25 years of clinical experience, the author has created an anatomy based, systemic treatment method called the Proximal Priority Laser Therapy (PPLT) where not only the cerebral cortex, spinal chord and peripheral nerves are treated but also the tracts of blood vessels and lymph ducts are treated as well. Treatment method and cases are presented herein.

  9. Range gated strip proximity sensor

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance.

  10. Grouping by proximity in haptic contour detection.

    PubMed

    Overvliet, Krista E; Krampe, Ralf Th; Wagemans, Johan

    2013-01-01

    We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots), relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection.

  11. Sugar proximity and human grip strength.

    PubMed

    Quintanar, A F; Hill, T V

    1988-12-01

    In a double-blind experiment with 90 undergraduate students the hypothesis was tested that proximity to sugar reduces human grip strength. An earlier study indicated that sugar proximity does indeed significantly reduce human grip strength. When additional controls were added to this design to reduce random sampling error, the hypothesis was not supported.

  12. Grouping by Proximity in Haptic Contour Detection

    PubMed Central

    Overvliet, Krista E.; Krampe, Ralf Th.; Wagemans, Johan

    2013-01-01

    We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots), relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection. PMID:23762364

  13. Proximal Participation: A Pathway into Work

    ERIC Educational Resources Information Center

    Chan, Selena

    2013-01-01

    In a longitudinal case study of apprentices, the term proximal participation was coined to describe the entry process of young people, with unclear career destinations, into the trade of baking. This article unravels the significance of proximal participation in the decision-making processes of young people who enter a trade through initial…

  14. Pyrazinoate transport in the isolated perfused rabbit proximal tubule.

    PubMed

    Besseghir, K; Roch-Ramel, F

    1986-12-01

    The bidirectional tubular transport of pyrazinoate (PZA) was studied in the isolated perfused proximal S2 segment of rabbit kidney. PZA reabsorption was a mechanism of large capacity, temperature-dependent and requiring a normal Na+/K+-ATPase activity. PZA reabsorption was reversibly decreased when lactate was added to the perfusate, indicating that it might occur through the sodium-lactate cotransport. The addition of PAH to the bath had a slight stimulatory effect on PZA reabsorption, suggesting a component of anion exchange in the overall PZA reabsorption. However, SITS added to either the perfusate or the bathing medium induced a non-significant decrease in PZA reabsorption, confirming the minor part of an anion exchange mechanism in this reabsorptive process. PZA reabsorption was not affected by the establishment of a bath-to-lumen H+ gradient, and was only moderately decreased after carbonic anhydrase inhibition by ethoxyzolamide, in opposition to what is known for the reabsorbed anion salicylate. The secretory transport of PZA was saturable and also dependent on a normal Na+/K+-ATPase activity. It is concluded that PZA is bidirectionally transported by facilitated mechanisms in the rabbit proximal S2 segment, one major reabsorptive mechanism appearing to be a sodium-anion cotransport, which might be the sodium-lactate reabsorbing mechanism.

  15. Cell volume regulation in the proximal convoluted tubule.

    PubMed

    Gagnon, J; Ouimet, D; Nguyen, H; Laprade, R; Le Grimellec, C; Carrière, S; Cardinal, J

    1982-10-01

    To evaluate the effect of hyper- and hypotonicity on proximal convoluted tubule (PCT) cell volume, nonperfused PCT were studied in vitro with hypertonic solutions containing sodium chloride, urea, or mannitol (450 mosmol/kg H2O) and with hypotonic low sodium chloride solutions (160 mosmol/kg H2O). When the tubules were subjected to hypertonic peritubular solutions containing NaCl, cell volume immediately decreased by 15.5% and remained constant throughout the experimental period (60 min). With mannitol, the initial decrease was identical to that with NaCl (17.7%), but the PCT volume increased slightly during the experimental period. With urea, the decrease in cell volume was smaller (7%) and transient. In hypotonicity, the PCT swelled rapidly, but this swelling was followed by a rapid regulatory phase in which PCT volume nearly returned to control values after less than 10 min. With a potassium-free peritubular medium or 10(-3) M ouabain, the regulatory phase of hypotonicity completely disappeared, whereas the cells did not maintain their reduced volume in NaCl-induced hypertonicity. These results suggest that Na-K-ATPase plays an important role in the maintenance of a reduced cellular volume in hypertonicity and in the regulatory phase of hypotonicity, probably by an active extrusion of sodium and water from the cell.

  16. Promoting proximal formative assessment with relational discourse

    NASA Astrophysics Data System (ADS)

    Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.

    2012-02-01

    The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.

  17. A Brief Index for Proximity Searching

    NASA Astrophysics Data System (ADS)

    Téllez, Eric Sadit; Chávez, Edgar; Camarena-Ibarrola, Antonio

    Many pattern recognition tasks can be modeled as proximity searching. Here the common task is to quickly find all the elements close to a given query without sequentially scanning a very large database.

  18. Polarization proximity effect in isolator crystal pairs.

    PubMed

    Linzon, Y; Ferrera, M; Razzari, L; Pignolet, A; Morandotti, R

    2008-12-01

    We experimentally study the polarization dynamics (orientation and ellipticity) of near-infrared light transmitted through magneto-optical yttrium iron garnet isolator crystal pairs using a modified balanced detection scheme. When the pair separation is in the submillimeter range, we observed a proximity effect in which the saturation field is reduced by up to 20%. One-dimensional calculations suggest that the proximity effect originates from magnetostatic interactions between the dipole moments of the isolator crystals.

  19. Proximity sensor system development. CRADA final report

    SciTech Connect

    Haley, D.C.; Pigoski, T.M.

    1998-01-01

    Lockheed Martin Energy Research Corporation (LMERC) and Merritt Systems, Inc. (MSI) entered into a Cooperative Research and Development Agreement (CRADA) for the development and demonstration of a compact, modular proximity sensing system suitable for application to a wide class of manipulator systems operated in support of environmental restoration and waste management activities. In teleoperated modes, proximity sensing provides the manipulator operator continuous information regarding the proximity of the manipulator to objects in the workspace. In teleoperated and robotic modes, proximity sensing provides added safety through the implementation of active whole arm collision avoidance capabilities. Oak Ridge National Laboratory (ORNL), managed by LMERC for the United States Department of Energy (DOE), has developed an application specific integrated circuit (ASIC) design for the electronics required to support a modular whole arm proximity sensing system based on the use of capacitive sensors developed at Sandia National Laboratories. The use of ASIC technology greatly reduces the size of the electronics required to support the selected sensor types allowing deployment of many small sensor nodes over a large area of the manipulator surface to provide maximum sensor coverage. The ASIC design also provides a communication interface to support sensor commands from and sensor data transmission to a distributed processing system which allows modular implementation and operation of the sensor system. MSI is a commercial small business specializing in proximity sensing systems based upon infrared and acoustic sensors.

  20. Proximity operations considerations affecting spacecraft design

    NASA Technical Reports Server (NTRS)

    Staas, Steven K.

    1991-01-01

    Experience from several recent spacecraft development programs, such as Space Station Freedom (SSF) and the Orbital Maneuvering Vehicle (OMV) has shown the need for factoring proximity operations considerations into the vehicle design process. Proximity operations, those orbital maneuvers and procedures which involve operation of two or more spacecraft at ranges of less than one nautical mile, are essential to the construction, servicing, and operation of complex spacecraft. Typical proximity operations considerations which drive spacecraft design may be broken into two broad categories; flight profile characteristics and concerns, and use of various spacecraft systems during proximity operations. Proximity operations flight profile concerns include the following: (1) relative approach/separation line; (2) relative orientation of the vehicles; (3) relative translational and rotational rates; (4) vehicle interaction, in the form of thruster plume impingement, mating or demating operations, or uncontrolled contact/collision; and (5) active vehicle piloting. Spacecraft systems used during proximity operations include the following: (1) sensors, such as radar, laser ranging devices, or optical ranging systems; (2) effector hardware, such as thrusters; (3) flight control software; and (4) mating hardware, needed for docking or berthing operations. A discussion of how these factors affect vehicle design follows, addressing both active and passive/cooperative vehicles.

  1. Conductances, diffusion and streaming potentials in the rat proximal tubule.

    PubMed Central

    De Mello, G B; Lopes, A G; Malnic, G

    1976-01-01

    1. Transtubular potential differences and specific resistances were measured in rat proximal tubules by means of single and double barrelled glass micro-electrodes. 2. Tip localization was made by observation of effective resistance changes measured with double barrelled micro-electrodes upon passage of oil droplets, and by perfusion with choline C1. 3. Mean early proximal p.d.s. of the order of -1 to -2 mV, and late values of +0-5 to +1mV were found. Mean specific resistances ranged from 12 to 15 omega cm2. 4. Diffusion potentials and single ion relative conductances were evaluated, perfusing the lumen with solutions differing only with respect to one salt concentration. Na and K conductances were similar and greater than those of C1. 5. Luminal and peritubular perfusions with hypotonic solutions showed the occurrence of streaming potentials in this structure suggesting the existence of pores lined with negative charges. The effective diameter of these pores appeared to be reduced by hypotonic perfusion, as evidenced by a significant increase in resistance, indicating that the main ion path across this structure is represented by intercellular spaces. PMID:10433

  2. Visualization of Calcium Dynamics in Kidney Proximal Tubules

    PubMed Central

    Szebényi, Kornélia; Füredi, András; Kolacsek, Orsolya; Csohány, Rózsa; Prókai, Ágnes; Kis-Petik, Katalin; Szabó, Attila; Bősze, Zsuzsanna; Bender, Balázs; Tóvári, József; Enyedi, Ágnes; Orbán, Tamás I.

    2015-01-01

    Intrarenal changes in cytoplasmic calcium levels have a key role in determining pathologic and pharmacologic responses in major kidney diseases. However, cell-specific delivery of calcium-sensitive probes in vivo remains problematic. We generated a transgenic rat stably expressing the green fluorescent protein-calmodulin–based genetically encoded calcium indicator (GCaMP2) predominantly in the kidney proximal tubules. The transposon-based method used allowed the generation of homozygous transgenic rats containing one copy of the transgene per allele with a defined insertion pattern, without genetic or phenotypic alterations. We applied in vitro confocal and in vivo two-photon microscopy to examine basal calcium levels and ligand- and drug-induced alterations in these levels in proximal tubular epithelial cells. Notably, renal ischemia induced a transient increase in cellular calcium, and reperfusion resulted in a secondary calcium load, which was significantly decreased by systemic administration of specific blockers of the angiotensin receptor and the Na-Ca exchanger. The parallel examination of in vivo cellular calcium dynamics and renal circulation by fluorescent probes opens new possibilities for physiologic and pharmacologic investigations. PMID:25788535

  3. Evaluation and Management of Proximal Humerus Fractures

    PubMed Central

    Khmelnitskaya, Ekaterina; Lamont, Lauren E.; Taylor, Samuel A.; Lorich, Dean G.; Dines, David M.; Dines, Joshua S.

    2012-01-01

    Proximal humerus fractures are common injuries, especially among older osteoporotic women. Restoration of function requires a thorough understanding of the neurovascular, musculotendinous, and bony anatomy. This paper addresses the relevant anatomy and highlights various management options, including indication for arthroplasty. In the vast majority of cases, proximal humerus fractures may be treated nonoperatively. In the case of displaced fractures, when surgical intervention may be pursued, numerous constructs have been investigated. Of these, the proximal humerus locking plate is the most widely used. Arthroplasty is generally reserved for comminuted 4-part fractures, head-split fractures, or fractures with significant underlying arthritic changes. Reverse total shoulder arthroplasty is reserved for patients with a deficient rotator cuff, or highly comminuted tuberosities. PMID:23316376

  4. Strategy for photostable proximity bioassays using lanthanides

    PubMed Central

    Haushalter, Jeanne P.; Faris, Gregory W.

    2011-01-01

    We report initial findings for research aimed at creating photostable lanthanide chelate reporters for proximity assays. These reporters take advantage of the nanometer scale distance dependence of fluorescence enhancement for molecules in the vicinity of noble metal nanoparticles and also capitalize on some unique properties of lanthanide chelates. This approach promises to lead to proximity assays that do not suffer from photobleaching and offer very high on/off enhancement ratios. Results for lanthanide chelates on silver island films and in colloidal suspensions are reported. Enhancement factors range from 1 to 2 orders of magnitude, with larger enhancements for strongly quenched lanthanides. PMID:17356638

  5. [Proximity and breastfeeding at the maternity hospital].

    PubMed

    Fradin-Charrier, Anne-Claire

    2015-01-01

    The establishment of breastfeeding, as well as its duration, are facilitated through the proximity of the mother with her new baby. However, in maternity hospitals, breastfeeding mothers very often leave their baby in the nursery at night time. A study carried out in 2014 in several maternity hospitals put forward suggestions and highlighted areas to improve in everyday practice.

  6. Vortices in normal part of proximity system

    DOE PAGES

    Kogan, V. G.

    2015-05-26

    It is shown that the order parameter Δ induced in the normal part of superconductor-normal-superconductor proximity system is modulated in the magnetic field differently from vortices in bulk superconductors. Whereas Δ turns zero at vortex centers, the magnetic structure of these vortices differs from that of Abrikosov's.

  7. Current status of proximal gastric vagotomy.

    PubMed Central

    Schirmer, B D

    1989-01-01

    Proximal gastric vagotomy is nearing its twentieth year in clinical use as an operation for peptic ulcer disease. No other acid-reducing operation has undergone as much scrutiny or study. At this time, the evidence of such studies and long-term follow-up strongly supports the use of proximal gastric vagotomy as the treatment of choice for chronic duodenal ulcer in patients who have failed medical therapy. Its application in treating the complications of peptic ulcer disease, which recently have come to represent an increasingly greater percentage of all operations done for peptic ulcer disease, is well-tested. However, initial series suggest that it should probably occupy a prominent role in treating some of these complications, particularly in selected patients, in the future. The operation has the well-documented ability to reduce gastric acid production, not inhibit gastric bicarbonate production, and also minimally inhibit gastric motility. The combination of these physiologic results after proximal gastric vagotomy, along with preservation of the normal antropyloroduodenal mechanism of gastrointestinal control, serve to allow patients with proximal gastric vagotomy the improved benefits of significantly fewer severe gastrointestinal side effects than are seen after other operations for peptic ulcer disease. PMID:2644897

  8. Encoding Direction when Interpreting Proximal Terms

    ERIC Educational Resources Information Center

    Ashley, Aaron; Carlson, Laura A.

    2007-01-01

    The location of an object is often described by spatially relating it to a known landmark. The spatial terms used in such descriptions can provide various types of information. For example, projective terms such as "above" indicate direction but not distance, whereas proximal terms such as "near" indicate distance but not direction. Previous…

  9. Object detection system using SPAD proximity detectors

    NASA Astrophysics Data System (ADS)

    Stark, Laurence; Raynor, Jeffrey M.; Henderson, Robert K.

    2011-10-01

    This paper presents an object detection system based upon the use of multiple single photon avalanche diode (SPAD) proximity sensors operating upon the time-of-flight (ToF) principle, whereby the co-ordinates of a target object in a coordinate system relative to the assembly are calculated. The system is similar to a touch screen system in form and operation except that the lack of requirement of a physical sensing surface provides a novel advantage over most existing touch screen technologies. The sensors are controlled by FPGA-based firmware and each proximity sensor in the system measures the range from the sensor to the target object. A software algorithm is implemented to calculate the x-y coordinates of the target object based on the distance measurements from at least two separate sensors and the known relative positions of these sensors. Existing proximity sensors were capable of determining the distance to an object with centimetric accuracy and were modified to obtain a wide field of view in the x-y axes with low beam angle in z in order to provide a detection area as large as possible. Design and implementation of the firmware, electronic hardware, mechanics and optics are covered in the paper. Possible future work would include characterisation with alternative designs of proximity sensors, as this is the component which determines the highest achievable accur1acy of the system.

  10. Laparoscopic Proximal Gastrectomy With Gastric Tube Reconstruction

    PubMed Central

    Shiraishi, Norio; Toujigamori, Manabu; Shiroshita, Hidefumi; Etoh, Tsuyoshi; Inomata, Masafumi

    2016-01-01

    Background and Objectives: There is no standardized method of reconstruction in laparoscopic proximal gastrectomy (LPG). We present a novel technique of reconstruction with a long, narrow gastric tube in LPG for early gastric cancer (EGC). Methods: During the laparoscopic procedure, the upper part of the stomach is fully mobilized with perigastric and suprapancreatic lymphadenectomy, and then the abdominal esophagus is transected. After a minilaparotomy is created, the entire stomach is pulled outside. A long, narrow gastric tube (20 cm long, 3 cm wide) is created with a linear stapler. The proximal part of the gastric tube is formed into a cobra head shape for esophagogastric tube anastomosis, which is then performed with a 45-mm linear stapler under laparoscopic view. The end of the esophagus is fixed on the gastric tube to prevent postoperative esophageal reflux. Results: Thirteen patients with early proximal gastric cancer underwent the procedure. The mean operative time was 283 min, and median blood loss was 63 ml. There were no conversions to open surgery, and no intraoperative complications. Conclusion: This new technique of reconstruction after LPG is simple and feasible. The procedure has the potential of becoming a standard reconstruction technique after LPG for proximal EGC. PMID:27547027

  11. Goal-Proximity Decision-Making

    ERIC Educational Resources Information Center

    Veksler, Vladislav D.; Gray, Wayne D.; Schoelles, Michael J.

    2013-01-01

    Reinforcement learning (RL) models of decision-making cannot account for human decisions in the absence of prior reward or punishment. We propose a mechanism for choosing among available options based on goal-option association strengths, where association strengths between objects represent previously experienced object proximity. The proposed…

  12. Proximity correction for electron beam lithography

    NASA Astrophysics Data System (ADS)

    Marrian, Christie R.; Chang, Steven; Peckerar, Martin C.

    1996-09-01

    As the critical dimensions required in mask making and direct write by electron beam lithography become ever smaller, correction for proximity effects becomes increasingly important. Furthermore, the problem is beset by the fact that only a positive energy dose can be applied with an electron beam. We discuss techniques such as chopping and dose shifting, which have been proposed to meet the positivity requirement. An alternative approach is to treat proximity correction as an optimization problem. Two such methods, local area dose correction and optimization using a regularizer proportional to the informational entropy of the solution, are compared. A notable feature of the regularized proximity correction is the ability to correct for forward scattering by the generation of a 'firewall' set back from the edge of a feature. As the forward scattering width increases, the firewall is set back farther from the feature edge. The regularized optimization algorithm is computationally time consuming using conventional techniques. However, the algorithm lends itself to a microelectronics integrated circuit coprocessor implementation, which could perform the optimization faster than even the fastest work stations. Scaling the circuit to larger number of pixels is best approached with a hybrid serial/parallel digital architecture that would correct for proximity effects over 108 pixels in about 1 h. This time can be reduced by simply adding additional coprocessors.

  13. Proximity correction for e-beam lithography

    NASA Astrophysics Data System (ADS)

    Marrian, Christie R.; Chang, Steven; Peckerar, Martin C.

    1995-12-01

    As the critical dimensions required for masks and e-beam direct write become ever smaller, the correction of proximity effects becomes more necessary. Furthermore, the problem is beset by the fact that only a positive energy dose can be applied with the e-beam. We discuss here approaches such as chopping and dose shifting which have been proposed to meet the positivity requirement. An alternative approach is to treat proximity correction as an optimization problem. Two such methods, local area dose correction and optimization using a regularizer proportional to the informational entropy of the solution, are compared. A notable feature of the regularized proximity correction is the ability to correct for forward scattering by the generation of a 'firewall' set back from the edge of a feature. As the forward scattering width increases, the firewall is set back further from the feature edge. The regularized optimization algorithm is computationally time consuming using conventional techniques. However, the algorithm lends itself to a microelectronics integrated circuit coprocessor implementation which could perform the optimization much faster than even the fastest work stations. Scaling the circuit to larger number of pixels is best approached with a hybrid serial/parallel digital architecture which would correct for proximity effects over 108 pixels about one hour. This time can be reduced by simply adding additional coprocessors.

  14. Localization of the calcium-regulated citrate transport process in proximal tubule cells.

    PubMed

    Hering-Smith, Kathleen S; Mao, Weibo; Schiro, Faith R; Coleman-Barnett, Joycelynn; Pajor, Ana M; Hamm, L Lee

    2014-06-01

    Urinary citrate is an important inhibitor of calcium-stone formation. Most of the citrate reabsorption in the proximal tubule is thought to occur via a dicarboxylate transporter NaDC1 located in the apical membrane. OK cells, an established opossum kidney proximal tubule cell line, transport citrate but the characteristics change with extracellular calcium such that low calcium solutions stimulate total citrate transport as well as increase the apparent affinity for transport. The present studies address several fundamental properties of this novel process: the polarity of the transport process, the location of the calcium-sensitivity and whether NaDC1 is present in OK cells. OK cells grown on permeable supports exhibited apical >basolateral citrate transport. Apical transport of both citrate and succinate was sensitive to extracellular calcium whereas basolateral transport was not. Apical calcium, rather than basolateral, was the predominant determinant of changes in transport. Also 2,3-dimethylsuccinate, previously identified as an inhibitor of basolateral dicarboxylate transport, inhibited apical citrate uptake. Although the calcium-sensitive transport process in OK cells is functionally not typical NaDC1, NaDC1 is present in OK cells by Western blot and PCR. By immunolocalization studies, NaDC1 was predominantly located in discrete apical membrane or subapical areas. However, by biotinylation, apical NaDC1 decreases in the apical membrane with lowering calcium. In sum, OK cells express a calcium-sensitive/regulated dicarboxylate process at the apical membrane which responds to variations in apical calcium. Despite the functional differences of this process compared to NaDC1, NaDC1 is present in these cells, but predominantly in subapical vesicles.

  15. Proximal Contact Repair of Complex Amalgam Restorations.

    PubMed

    Zguri, M N; Casey, J A; Jessup, J P; Vandewalle, K S

    2017-01-12

    The carving of a complex amalgam restoration may occasionally result in light proximal contact with the adjacent tooth. The purpose of this study was to investigate the strength of complex amalgam restorations repaired with a proximal slot amalgam preparation. Extracted human third molars of similar coronal size were sectioned 1 mm apical to the height of the contour using a saw and were randomly distributed into 9 groups of 10 teeth each. One pin was placed at each line angle of the flattened dentinal tooth surface. A metal matrix band was placed and an admixed alloy was condensed and carved to create a full crown contour but with a flat occlusal surface. A proximal slot was prepared with or without a retention groove and repaired using a single-composition spherical amalgam 15 minutes, 24 hours, one week, or six months after the initial crown condensation. The specimens were stored for 24 hours in 37°C water before fracture at the marginal ridge using a round-ended blade in a universal testing machine. The control group was not repaired. The mean maximum force in newtons and standard deviation were determined per group. Data were analyzed with a 2-way analysis of variance as well as Tukey and Dunnett tests (α=0.05). Significant differences were found between groups based on type of slot preparation (p=0.017) but not on time (p=0.327), with no significant interaction (p=0.152). No significant difference in the strength of the marginal ridge was found between any repair group and the unrepaired control group (p>0.076). The proximal repair strength of a complex amalgam restoration was not significantly different from an unrepaired amalgam crown. Placing a retention groove in the proximal slot preparation resulted in significantly greater fracture strength than a slot with no retention grooves. Time of repair had no significant effect on the strength of the repair.

  16. Characteristics of He II Proximity Profiles

    NASA Astrophysics Data System (ADS)

    Zheng, Wei; Syphers, David; Meiksin, Avery; Kriss, Gerard A.; Schneider, Donald P.; York, Donald G.; Anderson, Scott F.

    2015-06-01

    The proximity profile in the spectra of z≈ 3 quasars, where fluxes extend blueward of the He ii Lyα wavelength 304 (1+z) Å, is one of the most important spectral features in the study of the intergalactic medium (IGM). Based on the Hubble Space Telescope spectra of 24 He ii quasars, we find that the majority of them display a proximity profile, corresponding to an ionization radius as large as 20 Mpc in the source's rest frame. In comparison with those in the H i spectra of the quasars at z ≈ 6, the He ii proximity effect is more prominent and is observed over a considerably longer period of reionization. The He ii proximity zone sizes decrease at higher redshifts, particularly at z\\gt 3.3. This trend is similar to that for H i, signaling an onset of He ii reionization at z≳ 4. For quasar SDSS1253+6817 (z = 3.48), the He ii absorption trough displays a gradual decline and serves as a good case for modeling the He ii reionization. To model such a broad profile requires a quasar radiation field whose energy distribution between 4 and 1 Rydberg is considerably harder than normally assumed. The UV continuum of this quasar is indeed exceptionally steep, and the He ii ionization level in the quasar vicinity is higher than the average level in the IGM. These results are evidence that a very hard EUV continuum from this quasar produces a large ionized zone around it. Distinct exceptions are the two brightest He ii quasars at z ≈ 2.8, for which no significant proximity profile is present, probably implying that they are very young.

  17. Clinical Impact of Proximal Autosomal Imbalances

    PubMed Central

    Hamid, AB; Weise, A; Voigt, M; Bucksch, M; Kosyakova, N; Liehr, T; Klein, E

    2012-01-01

    Centromere-near gain of copy number can be induced by intra- or inter-chromosomal rearrangements or by the presence of a small supernumerary marker chromosome (sSMC). Interestingly, partial trisomy to hexasomy of euchromatic material may be present in clinically healthy or affected individuals, depending on origin and size of chromosomal material involved. Here we report the known minimal sizes of all centromere-near, i.e., proximal auto-somal regions in humans, which are tolerated; over 100 Mb of coding DNA are comprised in these regions. Additionally, we have summarized the typical symptoms for nine proximal autosomal regions including genes obviously sensitive to copy numbers. Overall, studying the carriers of specific chromosomal imbalances using genomics-based medicine, combined with single cell analysis can provide the genotype-phenotype correlations and can also give hints where copy-number-sensitive genes are located in the human genome. PMID:24052727

  18. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    PubMed Central

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despite routine post-operative skeletal traction in all cases and careful soft tissue interposition. One case showed significant heterotopic ossification which restricted prolonged sitting. This patient needed some occasional medication for pain. PMID:12180614

  19. Space robotic system for proximity operations

    NASA Technical Reports Server (NTRS)

    Magnani, P. G.; Colomba, M.

    1989-01-01

    Key to an efficient accomplishment of space station servicing operations is the development of a scenario where the presence of man in space is well integrated with the capability of teleoperated and automatic robot system outside the stations. Results focusing on mission requirements, trajectory sequences, propulsion subsystem features, and manipulative kit characteristics relevant to proximity servicing during a Man Tended Free Flyers Robotic Mission (MTFF-RM) are illustrated.

  20. Capacitive Proximity Sensor Has Longer Range

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1992-01-01

    Capacitive proximity sensor on robot arm detects nearby object via capacitive effect of object on frequency of oscillator. Sensing element part of oscillator circuit operating at about 20 kHz. Total capacitance between sensing element and ground constitutes tuning capacitance of oscillator. Sensor circuit includes shield driven by replica of alternating voltage applied to sensing element. Driven shield concentrates sensing electrostatic field in exterior region to enhance sensitivity to object. Sensitivity and dynamic range has corresponding 12-to-1 improvement.

  1. Proximal monomelic amyotrophy of the upper limb.

    PubMed

    Amir, D; Magora, A; Vatine, J J

    1987-07-01

    A 30-year-old patient of Central European origin, suffering from monomelic amyotrophy, is presented. The disease was characterized by proximal weakness of one upper limb, mainly of the shoulder girdle, accompanied by atrophy. The electrodiagnostic examination revealed signs of partial denervation in the presence of normal motor and sensory conduction. The disease, which is probably of the anterior horn cells, had a benign course and good prognosis, as evident from repeated examinations during a follow-up of eight years.

  2. Children's memory and proximity to violence.

    PubMed

    Pynoos, R S; Nader, K

    1989-03-01

    The study examined 133 school-age children's memory of a sniper attack at their elementary school. Researchers analyzed the role that spatial representation, memory markers, inner plans of action, and strategies of recall played in the memory process. In recalling the event, exposed children reduced their degree of life threat, while nonexposed children increased their proximity to the violence. Clinical and forensic implications are discussed.

  3. Endoscopic Proximal Hamstring Repair and Ischial Bursectomy

    PubMed Central

    Dierckman, Brian D.; Guanche, Carlos A.

    2012-01-01

    With the significant increase in use of the arthroscope around the hip have come several less invasive techniques to manage pathologies around this joint. This technical note with a video details one such technique that allows for the endoscopic management of proximal hamstring tears and chronic ischial bursitis, which until now have been managed exclusively with much larger open approaches. This procedure allows for complete exposure of the posterior aspect of the hip in a safe, minimally invasive fashion. PMID:23766996

  4. Technical implications in proximal forearm transplantation.

    PubMed

    Haddock, Nicholas T; Chang, Benjamin; Bozentka, David J; Steinberg, David R; Levin, Lawrence Scott

    2013-12-01

    The field of vascularized composite allotransplantation has developed for more than a decade. Investigators are defining patient selection criteria, transplant indications, immunologic regimens, and tolerance. The majority of the current reported hand transplantations have been for treatment of distal forearm or hand amputations. In more proximal amputees, the functional outcome of the transplanted arm has some unique variables that require a different surgical approach. We present a single case of bilateral proximal forearm transplantation in effort to describe the unique technical considerations in this complex procedure. The surgical procedure is described in detail. At 19 months, our patient had 4/5 strength of finger and thumb flexors and protective extensor as well as 4/5 wrist flexors and extensors. Our patient had recovery of sensation. Our patient now lives independently and does her lower extremity prosthesis independently using her hands. These results are expected to continue to improve with more time. In hand transplantation, functional results have been very promising. The described approach of forearm transplantation allows the transfer of the entire functional unit, which should optimize the ultimate outcome for these more proximal injuries.

  5. Trajectories in Close Proximity to Asteroids

    NASA Technical Reports Server (NTRS)

    Scheeres, D. J.

    2000-01-01

    Spacecraft motion in close proximity to irregularly shaped, rotating bodies such as asteroids presents a unique dynamical environment as compared to most space missions. There are several fundamental novelties in this environment that spacecraft must deal with. These include the possibility of orbital instabilities that can act over very short time spans (on the order of hours for some systems), possible non-uniform rotation of the central gravity field, divergence of traditional gravity field representations when close to the asteroid surface, dominance of perturbing forces, an extremely large asteroid model parameter space that must be prepared for in the absence of reliable information, and the possibility of employing new and novel trajectory control techniques such as hovering and repeated landings on the asteroid surface. An overview of how these novelties impact the space of feasible close proximity operations and how different asteroid model properties will affect their implementation is given. In so doing, four fundamental types of close proximity operations will be defined. Listed in order of increasing technical difficulty these are: (1) close, stable orbits; (2) low-altitude flyovers; (3) landing trajectories; and (4) hovering trajectories. The feasibility and difficulty of implementing these operations will vary as a function of the asteroid shape, size, density, and rotation properties, and as a function of the spacecraft navigation capability. Additional information is contained in the original extended abstract.

  6. Management of proximal humerus fractures in adults

    PubMed Central

    Vachtsevanos, Leonidas; Hayden, Lydia; Desai, Aravind S; Dramis, Asterios

    2014-01-01

    The majority of proximal humerus fractures are low-energy osteoporotic injuries in the elderly and their incidence is increasing in the light of an ageing population. The diversity of fracture patterns encountered renders objective classification of prognostic value challenging. Non-operative management has been associated with good functional outcomes in stable, minimally displaced and certain types of displaced fractures. Absolute indications for surgery are infrequent and comprise compound, pathological, multi-fragmentary head-splitting fractures and fracture dislocations, as well as those associated with neurovascular injury. A constantly expanding range of reconstructive and replacement options however has been extending the indications for surgical management of complex proximal humerus fractures. As a result, management decisions are becoming increasingly complicated, in an attempt to provide the best possible treatment for each individual patient, that will successfully address their specific fracture configuration, comorbidities and functional expectations. Our aim was to review the management options available for the full range of proximal humerus fractures in adults, along with their specific advantages, disadvantages and outcomes. PMID:25405098

  7. Proximity effect correction concerning forward scattering

    NASA Astrophysics Data System (ADS)

    Tsunoda, Dai; Shoji, Masahiro; Tsunoe, Hiroyuki

    2010-09-01

    The Proximity Effect is a critical problem in EB Lithography which is used in Photomask writing. Proximity Effect means that an electron shot by gun scatters by collided with resist molecule or substrate atom causes CD variation depending on pattern density [1]. Scattering by collision with resist molecule is called as "forward scattering", that affects in dozens of nanometer range, and with substrate atom is called as "backward scattering, that affects approximately 10 micrometer in 50keV acceleration voltage respectively. In conventional Proximity Effect Correction (PEC) for mask writing, we don't need to think forward scattering effect. However we should think about forward scattering because of smaller feature size. We have proposed a PEC software product named "PATACON PC-Cluster"[2], which can concern forward scattering and calculate optimum dose modulation. In this communication, we explain the PEC processing throughput when the that takes forward scattering into account. The key technique is to use different processing field size for forward scattering calculation. Additionally, the possibility is shown that effective PEC may be available by connecting forward scattering and backward scattering.

  8. Calibrating animal-borne proximity loggers.

    PubMed

    Rutz, Christian; Morrissey, Michael B; Burns, Zackory T; Burt, John; Otis, Brian; St Clair, James J H; James, Richard

    2015-06-01

    Growing interest in the structure and dynamics of animal social networks has stimulated efforts to develop automated tracking technologies that can reliably record encounters in free-ranging subjects. A particularly promising approach is the use of animal-attached 'proximity loggers', which collect data on the incidence, duration and proximity of spatial associations through inter-logger radio communication. While proximity logging is based on a straightforward physical principle - the attenuation of propagating radio waves with distance - calibrating systems for field deployment is challenging, since most study species roam across complex, heterogeneous environments.In this study, we calibrated a recently developed digital proximity-logging system ('Encounternet') for deployment on a wild population of New Caledonian crows Corvus moneduloides. Our principal objective was to establish a quantitative model that enables robust post hoc estimation of logger-to-logger (and, hence, crow-to-crow) distances from logger-recorded signal-strength values. To achieve an accurate description of the radio communication between crow-borne loggers, we conducted a calibration exercise that combines theoretical analyses, field experiments, statistical modelling, behavioural observations, and computer simulations.We show that, using signal-strength information only, it is possible to assign crow encounters reliably to predefined distance classes, enabling powerful analyses of social dynamics. For example, raw data sets from field-deployed loggers can be filtered at the analysis stage to include predominantly encounters where crows would have come to within a few metres of each other, and could therefore have socially learned new behaviours through direct observation. One of the main challenges for improving data classification further is the fact that crows - like most other study species - associate across a wide variety of habitats and behavioural contexts, with different signal

  9. 14 CFR 135.153 - Ground proximity warning system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ground proximity warning system. 135.153... Equipment § 135.153 Ground proximity warning system. (a) No person may operate a turbine-powered airplane... equipped with an approved ground proximity warning system. (b) (c) For a system required by this...

  10. 14 CFR 135.153 - Ground proximity warning system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ground proximity warning system. 135.153... Equipment § 135.153 Ground proximity warning system. (a) No person may operate a turbine-powered airplane... equipped with an approved ground proximity warning system. (b) (c) For a system required by this...

  11. Mechanisms of adaptation to chronic respiratory acidosis in the rabbit proximal tubule.

    PubMed Central

    Krapf, R

    1989-01-01

    The hyperbicarbonatemia of chronic respiratory acidosis is maintained by enhanced bicarbonate reabsorption in the proximal tubule. To investigate the cellular mechanisms involved in this adaptation, cell and luminal pH were measured microfluorometrically using (2",7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein in isolated, microperfused S2 proximal convoluted tubules from control and acidotic rabbits. Chronic respiratory acidosis was induced by exposure to 10% CO2 for 52-56 h. Tubules from acidotic rabbits had a significantly lower luminal pH after 1-mm perfused length (7.03 +/- 0.09 vs. 7.26 +/- 0.06 in controls, perfusion rate = 10 nl/min). Chronic respiratory acidosis increased the initial rate of cell acidification (dpHi/dt) in response to luminal sodium removal by 63% and in response to lowering luminal pH (7.4-6.8) by 69%. Chronic respiratory acidosis also increased dpHi/dt in response to peritubular sodium removal by 63% and in response to lowering peritubular pH by 73%. In conclusion, chronic respiratory acidosis induces a parallel increase in the rates of the luminal Na/H antiporter and the basolateral Na/(HCO3)3 cotransporter. Therefore, the enhanced proximal tubule reabsorption of bicarbonate in chronic respiratory acidosis may be, at least in part, mediated by a parallel adaptation of these transporters. PMID:2537851

  12. Superconductivity in Magnetic and Proximity Effect Systems.

    NASA Astrophysics Data System (ADS)

    Stephan, Walter Hugo

    Some aspects of the theory of superconductors containing paramagnetic impurities in the model of Shiba and Rusinov (SR) are examined. The critical magnetic field deviation function is shown to be very sensitive to the SR scattering parameter varepsilon_0 , with improved agreement with experiment for Zn -Mn as compared to the theory of Abrikosov and Gor'Kov (AG). Optical absorption and thermal conductivity experiments involving a variety of transition metal alloys are reanalyzed including up to three scattering phase shifts, with no significant improvement found over the agreement obtained with only a single phase shift. The electromagnetic coherence length with SR impurities is also considered. Model calculations for superconducting spin-glasses show that systems such as Gd{_ {x}Ce}_{1-{rm x} }{rm Ru_2}, which exhibit significant deviations from the AG prediction for the reduction of the critical temperature with impurity concentration, are also expected to exhibit significant deviations from AG behavior for properties such as the thermodynamic critical field and the electromagnetic penetration depth. The model of Lee for reentrant ferromagnetic superconductors is shown to be only in qualitative agreement with the free energy difference and thermal conductivity determined experimentally for ErRh_{4}B _{4}. A variety of properties of proximity effect junctions are considered within the McMillan model. The temperature dependence of the free energy difference differs significantly from that of a BCS superconductor, with the deviation function becoming much more negative than the BCS prediction. The optical absorption and the low temperature magnetic penetration depth of the normal side of a proximity effect junction with magnetic impurities are also calculated. Finally, the temperature dependence of the zero bias tunneling conductance of a proximity effect induced superconducting spin glass is calculated and found to be in reasonable agreement with experiments

  13. Hand Replantation with Proximal Row Carpectomy

    PubMed Central

    Lee, Young-Keun; Lee, Hang-Ho; Park, Ji-Kang; Kim, Joo-Yong; Dhawan, Vikas

    2008-01-01

    The purpose of this study is to present our operative technique and postoperative results of the hand replantation with proximal row carpectomy in cases of complete amputation at the level of wrist joint. From May 2003 to April 2005, five patients suffered from complete amputation of the hand due to industrial trauma. Amputation level was radiocarpal joint in three cases and midcarpal joint in two cases. Three cases represented guillotine type and two cases with local crush type injuries. All were men and the mean age was 26.6 years. The mean follow-up period was 26.8 months. At the time of replantation, the wrist joint was stabilized with transarticular fixation using three to four Kirschner’s wires after performing proximal row carpectomy. Postoperatively, functional results such as muscle strength, range of motion of the wrist and fingers, and sensory recovery were assessed according to Chen’s criteria. Joint width and arthritic changes of the radio-capitate joint were evaluated with radiologic tools. According to Chen’s criteria, the overall results in five cases were classified as grade II. Intrinsic muscle power of hands was found to be grade 4. The mean grip and pinch powers were 41% and 45%, respectively, compared to contralateral hand. The mean arc of flexion–extension of wrist was 53°. Total mean active motion of fingers was 215 degrees. Static two-point discrimination of fingertip ranged from 8 to 13 mm. On the follow-up, computerized tomography showed well-preserved radio-capitate joint space without any arthritic changes. While performing hand replantation after amputation at the radiocarpal or midcarpal level, proximal row carpectomy is a useful procedure to preserve joint motion of the wrist in selected cases. PMID:18855073

  14. Periprosthetic proximal femur fractures: current concepts.

    PubMed

    Parvizi, Javad; Vegari, David N

    2011-06-01

    With the increase in demand for total hip and knee arthroplasty, the orthopaedic community has seen a dramatic increase in periprosthetic fractures. Given the high morbidity and mortality associated with these fractures, the orthopaedic surgeon needs to be prepared to deal with this difficult problem. The purpose of this article is to provide the surgeon with an algorithmic approach that allows for easy classification and treatment options for periprosthetic fractures of the proximal femur. Such an approach should prevent the mismanagement of these complications.

  15. Impacted valgus fractures of the proximal humerus☆

    PubMed Central

    Ribeiro, Fabiano Rebouças; Takesian, Fernando Hovaguim; Bezerra, Luiz Eduardo Pimentel; Filho, Rômulo Brasil; Júnior, Antonio Carlos Tenor; da Costa, Miguel Pereira

    2016-01-01

    Impacted valgus fractures of the proximal humerus are considered to be a special type fracture, since impaction of the humeral head on the metaphysis with maintenance of the posteromedial periosteum improves the prognosis regarding occurrences of avascular necrosis. This characteristic can also facilitate the reduction maneuver and increase the consolidation rate of these fractures, even in more complex cases. The studies included were obtained by searching the Bireme, Medline, PubMed, Cochrane Library and Google Scholar databases for those published between 1991 and 2013. The objective of this study was to identify the most common definitions, classifications and treatment methods used for these fractures in the orthopedic medical literature. PMID:27069878

  16. Fractures of the proximal humeral epiphysis.

    PubMed

    Burgos-Flores, J; Gonzalez-Herranz, P; Lopez-Mondejar, J A; Ocete-Guzman, J G; Amaya-Alarcón, S

    1993-01-01

    Twenty-two patients with marked displacement of a fracture of the proximal humeral epiphysis have been treated with closed or open reduction and fixation by Kirschner wires. At an average follow-up of 6.8 years there have been good functional results in almost all patients (91.1), with better results in patients under 13 years of age particularly with less residual displacement or angulation. Since there is a greater occurrence of residual deformity and symmetria and limitation of motion in older patients, a more aggressive approach to correct the initial displacement and angulation is warranted in those over the age of 13 years.

  17. Unilateral Isolated Proximal Femoral Focal Deficiency

    PubMed Central

    Doğer, Emek; Köpük, Şule Y.; Çakıroğlu, Yiğit; Çakır, Özgür; Yücesoy, Gülseren

    2013-01-01

    Objective. To discuss a patient with a prenatal diagnosis of unilateral isolated femoral focal deficiency. Case. Antenatal diagnosis of unilateral isolated femoral focal deficiency was made at 20 weeks of gestation. The length of left femur was shorter than the right, and fetal femur length was below the fifth percentile. Proximal femoral focal deficiency was diagnosed. After delivery, the diagnosis was confirmed with skeletal radiographs and magnetic resonance imaging. In prenatal ultrasonographic examination, the early recognition and exclusion of skeletal dysplasias is important; moreover, treatment plans should be initiated, and valuable information should be provided to the family. PMID:23984135

  18. Impacted valgus fractures of the proximal humerus.

    PubMed

    Ribeiro, Fabiano Rebouças; Takesian, Fernando Hovaguim; Bezerra, Luiz Eduardo Pimentel; Filho, Rômulo Brasil; Júnior, Antonio Carlos Tenor; da Costa, Miguel Pereira

    2016-01-01

    Impacted valgus fractures of the proximal humerus are considered to be a special type fracture, since impaction of the humeral head on the metaphysis with maintenance of the posteromedial periosteum improves the prognosis regarding occurrences of avascular necrosis. This characteristic can also facilitate the reduction maneuver and increase the consolidation rate of these fractures, even in more complex cases. The studies included were obtained by searching the Bireme, Medline, PubMed, Cochrane Library and Google Scholar databases for those published between 1991 and 2013. The objective of this study was to identify the most common definitions, classifications and treatment methods used for these fractures in the orthopedic medical literature.

  19. Management of posttraumatic proximal interphalangeal joint contracture.

    PubMed

    Houshian, Shirzad; Jing, Shan Shan; Chikkamuniyappa, Chandrasekar; Kazemian, Gholam Hussein; Emami-Moghaddam-Tehrani, Mohammad

    2013-08-01

    Chronic flexion contracture of the proximal interphalangeal (PIP) joint presents a common yet challenging problem to hand surgeons. Over the years, multiple treatment modalities have been described for this problem, producing limited results. Nonoperative treatment using serial casting and splints should be tried before attempting open surgical release, which should be done in selected patients. The use of external fixation for treating PIP contracture has been encouraging and can be a useful alterative. This review provides an update on the current management of PIP joint contractures and presents a flowchart of treatment to aid decision making.

  20. Fiber optical ranging sensor for proximity fuse

    NASA Astrophysics Data System (ADS)

    Du, Fang; Chi, Zeying; You, Mingjun; Chen, Wenjian

    1996-09-01

    A fiber optical ranging sensor used in laser proximity fuze is described in this paper. In the fuze, pulse laser diode (LD) is used as light source and trigger signal is generated by comparing the reflected light pulses with the reference pulses by a correlator after they were converted into electric signals by PIN photodiodes. Multi-mode fibers and integrated optical devices are used in the system so that the structure can be more compact. Optical fiber delay line is used to offer precise delay time for reference channel.

  1. Open Subpectoral Tenodesis of the Proximal Biceps.

    PubMed

    Voss, Andreas; Cerciello, Simone; Yang, Justin; Beitzel, Knut; Cote, Mark P; Mazzocca, Augustus D

    2016-01-01

    This article summarizes both the various techniques for an open subpectoral biceps tenodesis as well as the biomechanics associated with these procedures. It provides information regarding the indications and contraindications to support the surgeon's decision. Furthermore, a postoperative protocol as well as an outcome overview is presented to address postoperative care. A short summary of the recent literature regarding potential complications is included to provide further insight on this technique. The open subpectoral tenodesis of the long head of the biceps is a safe and reproducible technique with a low complication rate for patients with pathologies of the proximal biceps.

  2. Complications of Proximal Biceps Tenotomy and Tenodesis.

    PubMed

    Virk, Mandeep S; Nicholson, Gregory P

    2016-01-01

    The long head of biceps tendon (LHBT) is a well-recognized cause of anterior shoulder pain. Tenotomy or tenodesis of the LHBT is an effective surgical solution for relieving pain arising from the LHBT. Cosmetic deformity of the arm, cramping or soreness in the biceps muscle, and strength deficits in elbow flexion and supination are the three most common adverse events associated with tenotomy of the LHBT. Complications associated with tenodesis of the LHBT include loss of fixation resulting in cosmetic deformity, residual groove pain, pain or soreness in the biceps muscle, infection, stiffness, hematoma, neurologic injury, vascular injury, proximal humerus fracture, and reflex sympathetic dystrophy.

  3. Space station proximity operations and window design

    NASA Technical Reports Server (NTRS)

    Haines, Richard F.

    1988-01-01

    On-orbit proximity operations (PROX-OPS) consist of all extravehicular activity (EVA) within 1 km of the space station. Because of the potentially large variety of PROX-OPS, very careful planning for space station windows is called for and must consider a great many human factors. The following topics are discussed: (1) basic window design philosophy and assumptions; (2) the concept of the local horizontal - local vertical on-orbit; (3) window linear dimensions; (4) selected anthropomorphic considerations; (5) displays and controls relative to windows; and (6) full window assembly replacement.

  4. Extracellular Antibody Drug Conjugates Exploiting the Proximity of Two Proteins

    PubMed Central

    Marshall, David J; Harried, Scott S; Murphy, John L; Hall, Chad A; Shekhani, Mohammed S; Pain, Christophe; Lyons, Conner A; Chillemi, Antonella; Malavasi, Fabio; Pearce, Homer L; Thorson, Jon S; Prudent, James R

    2016-01-01

    The human Na+/K+-ATPase (NKA) is a plasma membrane ion pump that uses ATP to help maintain the resting potential of all human cells. Inhibition of the NKA leads to cell swelling and death. The results of this investigation show that on cancer cells, the NKA either comes in close proximity to, associate with or complexes to important cancer-related proteins, and thus can be targeted with a new type of precision therapy called the extracellular drug conjugate or EDC. The EDCs reported here exhibit EC50 values in the low to mid-picomolar range, and signal to noise ratios > 1,000:1, both of which are dependent on the cell surface expression of the NKA and corresponding cancer-related target. We demonstrate that a potent small molecule inhibitor of the NKA can be covalently attached to antibodies targeting CD20, CD38, CD56, CD147, or dysadherin, to create a series of selective and powerful EDCs that kill cancer cells extracellularly by a mechanism resembling necrosis. This is therefore a framework for the development of a new type of precision therapy wherein exquisite selectivity is achieved for targeting extracellular disease-related proteins. PMID:27434591

  5. Proximate determinants of fertility in peninsular Malaysia.

    PubMed

    Tey, Nai Peng; Ng, Sor Tho; Yew, Siew Yong

    2012-05-01

    The continuing decline in fertility despite a contraction in contraceptive use in Peninsular Malaysia since the mid-1980s has triggered considerable interest in the reasons behind this phenomenon, such as increase in abortion, sterility, and out-of-wedlock pregnancy. Fertility decline has been attributed to rapid socioeconomic development, which can only influence fertility through the intermediate variables. Application of vital statistics, population census, and survey data of Peninsular Malaysia on Bongaarts's model vindicates that marriage postponement and contraceptive use are the 2 most important proximate determinants of fertility, but the effects are not uniform across the ethnic groups. For instance, the predicted total fertility rate for Chinese and Malays are 2.9 and 1.6, respectively, compared with the observed level of 3.0 and 1.9. Postpartum infecundability and abortion also play a part in explaining ethnic fertility differentials. The fertility inhibiting effects of these proximate determinants have significant implications on reproductive health and future population growth.

  6. Phylogenetic proximity revealed by neurodevelopmental event timings.

    PubMed

    Nagarajan, Radhakrishnan; Clancy, Barbara

    2008-01-01

    Statistical properties such as distribution and correlation signatures were investigated using a temporal database of common neurodevelopmental events in the three species most frequently used in experimental studies, rat, mouse, and macaque. There was a fine nexus between phylogenetic proximity and empirically derived dates of the occurrences of 40 common events including the neurogenesis of cortical layers and outgrowth milestones of developing axonal projections. Exponential and power-law approximations to the distribution of the events reveal strikingly similar decay patterns in rats and mice when compared to macaques. Subsequent hierarchical clustering of the common event timings also captures phylogenetic proximity, an association further supported by multivariate linear regression data. These preliminary results suggest that statistical analyses of the timing of developmental milestones may offer a novel measure of phylogenetic classifications. This may have added pragmatic value in the specific support it offers for the reliability of rat/mouse comparative modeling, as well as in the broader implications for the potential of meta-analyses using databases assembled from the extensive empirical literature.

  7. Synostosis of the Proximal Tibiofibular Joint

    PubMed Central

    Sferopoulos, Nikolaos K.

    2010-01-01

    The incidence of synostosis of the proximal tibiofibular joint (TFJ) was assessed among 1029 patients examined for osteoarthritis of the knee in a 4-year period. Radiographic evidence of a synostosis of the proximal TFJ was demonstrated in 3 knees (3 patients). The synostosis appeared incidental and was not the cause of symptoms in any of them. These patients were further examined with MRI and/or CT scans. In two cases, which were found to be primary (idiopathic), the synostosis was complete and bony. In a third case the lesion was secondary (acquired) to surgical reconstruction for a depressed fracture of the lateral tibial plateau. This iatrogenic complication followed open reduction, internal fixation, and grafting with synthetic bone. The bridging of the joint on the CT views was partial and compatible with ectopic calcification rather than ossification. The patients were treated conservatively and were followed for an average period of 3 years. No evidence that the synostosis accelerated the onset or progression of the degenerative changes to the ipsilateral knee could be verified. PMID:20592991

  8. An improved proximity force approximation for electrostatics

    SciTech Connect

    Fosco, Cesar D.; Lombardo, Fernando C.; Mazzitelli, Francisco D.

    2012-08-15

    A quite straightforward approximation for the electrostatic interaction between two perfectly conducting surfaces suggests itself when the distance between them is much smaller than the characteristic lengths associated with their shapes. Indeed, in the so called 'proximity force approximation' the electrostatic force is evaluated by first dividing each surface into a set of small flat patches, and then adding up the forces due two opposite pairs, the contributions of which are approximated as due to pairs of parallel planes. This approximation has been widely and successfully applied in different contexts, ranging from nuclear physics to Casimir effect calculations. We present here an improvement on this approximation, based on a derivative expansion for the electrostatic energy contained between the surfaces. The results obtained could be useful for discussing the geometric dependence of the electrostatic force, and also as a convenient benchmark for numerical analyses of the tip-sample electrostatic interaction in atomic force microscopes. - Highlights: Black-Right-Pointing-Pointer The proximity force approximation (PFA) has been widely used in different areas. Black-Right-Pointing-Pointer The PFA can be improved using a derivative expansion in the shape of the surfaces. Black-Right-Pointing-Pointer We use the improved PFA to compute electrostatic forces between conductors. Black-Right-Pointing-Pointer The results can be used as an analytic benchmark for numerical calculations in AFM. Black-Right-Pointing-Pointer Insight is provided for people who use the PFA to compute nuclear and Casimir forces.

  9. Proteomics of Primary Cilia by Proximity Labeling

    PubMed Central

    Mick, David U.; Rodrigues, Rachel B.; Leib, Ryan D.; Adams, Christopher M.; Chien, Allis S.; Gygi, Steven P.; Nachury, Maxence V.

    2015-01-01

    SUMMARY While cilia are recognized as important signaling organelles, the extent of ciliary functions remains unknown because of difficulties in cataloguing proteins from mammalian primary cilia. We present a method that readily captures rapid snapshots of the ciliary proteome by selectively biotinylating ciliary proteins using a cilia-targeted proximity labeling enzyme (cilia-APEX). Besides identifying known ciliary proteins, cilia-APEX uncovered several ciliary signaling molecules. The kinases PKA, AMPK and LKB1 were validated as bona fide ciliary proteins and PKA was found to regulate Hedgehog signaling in primary cilia. Furthermore, proteomics profiling of Ift27/Bbs19 mutant cilia correctly detected BBSome accumulation inside Ift27−/− cilia and revealed that β-arrestin 2 and the viral receptor CAR are candidate cargoes of the BBSome. This work demonstrates that proximity labeling can be applied to proteomics of non-membrane-enclosed organelles and suggests that proteomics profiling of cilia will enable a rapid and powerful characterization of ciliopathies. PMID:26585297

  10. Carbon nanotube proximity influences rice DNA

    NASA Astrophysics Data System (ADS)

    Katti, Dinesh R.; Sharma, Anurag; Pradhan, Shashindra Man; Katti, Kalpana S.

    2015-07-01

    The uptake of carbon nanotubes (CNT) influences the output of plants, potentially through interactions between the DNA and CNTs. However, little is known about the changes in the plant DNA due to CNT proximity. We report changes in rice plant DNA in the proximity of single walled CNT (SWCNT) using molecular dynamics simulations. The DNA experiences breaking and forming of hydrogen bonds due to unzipping of Watson-Crick (WC) nucleobase pairs and wrapping onto SWCNT. The number of hydrogen bonds between water and DNA nucleobases decreases due to the presence of SWCNT. A higher number of guanine-cytosine (Gua-Cyt) WC hydrogen bonds break as compared to adenine-thymine (Ade-Thy), which suggests that Gua and Cyt bases play a dominant role in DNA-SWCNT interactions. We also find that changes to non-WC nucleobase pairs and van der Waals attractive interactions between WC nucleobase pairs and SWCNT cause significant changes in the conformation of the DNA.

  11. Empathy: Its ultimate and proximate bases.

    PubMed

    Preston, Stephanie D; de Waal, Frans B M

    2002-02-01

    There is disagreement in the literature about the exact nature of the phenomenon of empathy. There are emotional, cognitive, and conditioning views, applying in varying degrees across species. An adequate description of the ultimate and proximate mechanism can integrate these views. Proximately, the perception of an object's state activates the subject's corresponding representations, which in turn activate somatic and autonomic responses. This mechanism supports basic behaviors (e.g., alarm, social facilitation, vicariousness of emotions, mother-infant responsiveness, and the modeling of competitors and predators) that are crucial for the reproductive success of animals living in groups. The Perception-Action Model (PAM), together with an understanding of how representations change with experience, can explain the major empirical effects in the literature (similarity, familiarity, past experience, explicit teaching, and salience). It can also predict a variety of empathy disorders. The interaction between the PAM and prefrontal functioning can also explain different levels of empathy across species and age groups. This view can advance our evolutionary understanding of empathy beyond inclusive fitness and reciprocal altruism and can explain different levels of empathy across individuals, species, stages of development, and situations.

  12. The convergence rate of the proximal alternating direction method of multipliers with indefinite proximal regularization.

    PubMed

    Sun, Min; Liu, Jing

    2017-01-01

    The proximal alternating direction method of multipliers (P-ADMM) is an efficient first-order method for solving the separable convex minimization problems. Recently, He et al. have further studied the P-ADMM and relaxed the proximal regularization matrix of its second subproblem to be indefinite. This is especially significant in practical applications since the indefinite proximal matrix can result in a larger step size for the corresponding subproblem and thus can often accelerate the overall convergence speed of the P-ADMM. In this paper, without the assumptions that the feasible set of the studied problem is bounded or the objective function's component [Formula: see text] of the studied problem is strongly convex, we prove the worst-case [Formula: see text] convergence rate in an ergodic sense of the P-ADMM with a general Glowinski relaxation factor [Formula: see text], which is a supplement of the previously known results in this area. Furthermore, some numerical results on compressive sensing are reported to illustrate the effectiveness of the P-ADMM with indefinite proximal regularization.

  13. Role of proximal tubules in the pathogenesis of kidney disease.

    PubMed

    Nakhoul, Nazih; Batuman, Vecihi

    2011-01-01

    The proximal tubules make up a significant portion of the kidneys; proximal tubule epithelial cells are the most populous cell type in the kidney, and carry out diverse regulatory and endocrine functions where numerous transporters are located. Under normal circumstances, more than two thirds of filtered salt and water, and all filtered bicarbonate is reabsorbed in the proximal tubule. A number of inherited and acquired acid-base and tubule disorders are linked to impaired transporters in the proximal tubule cells. Equally important is the intrinsic immune characteristics of proximal tubule cells that give them the ability to also function as immune responders to a wide range of immunologic, ischemic or toxic injury. It is therefore not surprising that proximal tubule-related phenomena are closely related to the pathogenesis of a vast array of kidney diseases. Many kidney diseases, acute and chronic, first manifest with proximal tubule disorders. Recent insight into molecular characteristics of transport functions in the proximal tubules, and the recognition that proximal tubule cells possess intrinsic immune responses have contributed to an improved understanding of important areas in nephrology, such as Fanconi's syndrome, renal tubular acidosis, phosphate wasting syndromes, Dent's disease, cystinuria and other amino acid transport disorders, acute kidney injury, and the role of proximal tubules in progressive kidney disease. Megalin/ cubilin-mediated endocytosis by proximal tubule cells of increased quantities of filtered proteins (protein overloading) in glomerular diseases appears to evoke cell stress responses resulting in increased inflammatory cytokines leading to tubulointerstitial inflammation and fibrosis. Finally, the proximal tubule may be the site of both active vitamin D synthesis through the action of 1-α-hydroxylase, and the site where erythropoietin synthesis takes place. Thus, proximal tubule injury also contributes to two distressing

  14. Proximity effects in ferromagnet-superconductor structures

    NASA Astrophysics Data System (ADS)

    Halterman, Klaus Byron

    I present an extensive theoretical investigation of the proximity effects that occur in ferromagnet/superconductor systems. I use a numerical method to solve self consistently the Bogoliubov-de Gennes equations in the continuum. I obtain the pair amplitude and the local density of states (DOS), and use these results to extract the relevant lengths characterizing both the leakage of superconductivity into the magnet and to study spin splitting induced in the superconductor. These phenomena are investigated as a function of parameters such as temperature, magnet polarization, interfacial scattering, sample size and Fermi wave vector mismatch, all of which turn out to have an important influence on the results. These comprehensive results should help characterize and analyze future data, and are shown to be in agreement with existing experiments.

  15. Parallel Proximity Detection for Computer Simulations

    NASA Technical Reports Server (NTRS)

    Steinman, Jeffrey S. (Inventor); Wieland, Frederick P. (Inventor)

    1998-01-01

    The present invention discloses a system for performing proximity detection in computer simulations on parallel processing architectures utilizing a distribution list which includes movers and sensor coverages which check in and out of grids. Each mover maintains a list of sensors that detect the mover's motion as the mover and sensor coverages check in and out of the grids. Fuzzy grids are included by fuzzy resolution parameters to allow movers and sensor coverages to check in and out of grids without computing exact grid crossings. The movers check in and out of grids while moving sensors periodically inform the grids of their coverage. In addition, a lookahead function is also included for providing a generalized capability without making any limiting assumptions about the particular application to which it is applied. The lookahead function is initiated so that risk-free synchronization strategies never roll back grid events. The lookahead function adds fixed delays as events are scheduled for objects on other nodes.

  16. Parallel Proximity Detection for Computer Simulation

    NASA Technical Reports Server (NTRS)

    Steinman, Jeffrey S. (Inventor); Wieland, Frederick P. (Inventor)

    1997-01-01

    The present invention discloses a system for performing proximity detection in computer simulations on parallel processing architectures utilizing a distribution list which includes movers and sensor coverages which check in and out of grids. Each mover maintains a list of sensors that detect the mover's motion as the mover and sensor coverages check in and out of the grids. Fuzzy grids are includes by fuzzy resolution parameters to allow movers and sensor coverages to check in and out of grids without computing exact grid crossings. The movers check in and out of grids while moving sensors periodically inform the grids of their coverage. In addition, a lookahead function is also included for providing a generalized capability without making any limiting assumptions about the particular application to which it is applied. The lookahead function is initiated so that risk-free synchronization strategies never roll back grid events. The lookahead function adds fixed delays as events are scheduled for objects on other nodes.

  17. [Ophthalmologists in the proximity of Adolf Hitler].

    PubMed

    Rohrbach, J M

    2012-10-01

    Adolf Hitler met or at least knew about 5 ophthalmologists. The chair of ophthalmology in Berlin, Walther Löhlein, personally examined Hitler's eyes at least two times. The chair of ophthalmology in Breslau, Walter Dieter, developed "air raid protection spectacles" with the aid of high representatives of the NS-system and probably Adolf Hitler himself. Heinrich Wilhelm Kranz became rector of the universities of Giessen and Frankfurt/Main. He was known as a very strict advocate of the NS-race hygiene. Werner Zabel made plans for Hitler's diet and tried to interfere with Hitler's medical treatment. Finally, Hellmuth Unger was an influential representative of the medical press and a famous writer. Three of his novels with medical topics were made into a film which Hitler probably saw. Hitler had, so to say, a small "ophthalmological proximity" which, however, did not play a significant role for himself or the NS-state.

  18. Proximity to mining industry and cancer mortality.

    PubMed

    Fernández-Navarro, Pablo; García-Pérez, Javier; Ramis, Rebeca; Boldo, Elena; López-Abente, Gonzalo

    2012-10-01

    Mining installations are releasing toxic substances into the environment which could pose a health problem to populations in their vicinity. We sought to investigate whether there might be excess cancer-related mortality in populations residing in towns lying in the vicinity of Spanish mining industries governed by the Integrated Pollution Prevention and Control Directive, and the European Pollutant Release and Transfer Register Regulation, according to the type of extraction method used. An ecologic study was designed to examine municipal mortality due to 32 types of cancer, across the period 1997 through 2006. Population exposure to pollution was estimated on the basis of distance from town of residence to pollution source. Poisson regression models, using the Bayesian conditional autoregressive model proposed by Besag, York and Molliè and Integrated Nested Laplace Approximations for Bayesian inference, were used: to analyze risk of dying from cancer in a 5-kilometer zone around mining installations; effect of type of industrial activity; and to conduct individual analyses within a 50-kilometer radius of each installation. Excess mortality (relative risk, 95% credible interval) of colorectal cancer (1.097, 1.041-1.157), lung cancer (1.066, 1.009-1.126) specifically related with proximity to opencast coal mining, bladder cancer (1.106, 1.016-1.203) and leukemia (1.093, 1.003-1.191) related with other opencast mining installations, was detected among the overall population in the vicinity of mining installations. Other tumors also associated in the stratified analysis by type of mine, were: thyroid, gallbladder and liver cancers (underground coal installations); brain cancer (opencast coal mining); stomach cancer (coal and other opencast mining installations); and myeloma (underground mining installations). The results suggested an association between risk of dying due to digestive, respiratory, hematologic and thyroid cancers and proximity to Spanish mining

  19. Physiological pH. Effects on posthypoxic proximal tubular injury.

    PubMed

    Zager, R A; Schimpf, B A; Gmur, D J

    1993-04-01

    After O2 deprivation, tissue acidosis rapidly self-corrects. This study assessed the effect of this pH correction on the induction, and pathways, of posthypoxic proximal tubular injury. In addition, ways to prevent the resultant injury were explored. Isolated rat proximal tubular segments (PTSs) were subjected to hypoxia/reoxygenation (50/30 or 30/50 minutes) under the following incubation conditions: 1) continuous pH 7.4, 2) continuous pH 6.8, or 3) hypoxia at pH 6.8 and reoxygenation at pH 7.4 (NaHCO3 or Tris base addition). Continuously oxygenated PTSs maintained under these same pH conditions served as controls. Lethal cell injury was assessed by lactate dehydrogenase (LDH) release. pH effects on several purported pathways of hypoxia/reoxygenation injury were also assessed (ATP depletion, lipid peroxidation, and membrane deacylation). Acidosis blocked hypoxic LDH release (pH 7.4, 50 +/- 2%; pH 6.8, 6 +/- 1%) without mitigating membrane deacylation or ATP depletion. During reoxygenation, minimal LDH was released (3-5%) if pH was held constant. However, if posthypoxic pH was corrected, immediate (< or = 5 minutes) and marked cell death (e.g., 55 +/- 3% with Tris) occurred. This was dissociated from lipid peroxidation or new deacylation, and it was preceded by a depressed ATP/ADP ratio (suggesting an acidosis-associated defect in hypoxic/posthypoxic cell energetics). Realkalinization injury was not inevitable, since it could be substantially blocked by 1) posthypoxic glycine addition, 2) transient posthypoxic hypothermia, or 3) allowing a 10-minute reoxygenation (cell recovery) period before base addition. Neither mannitol nor graded buffer Ca2+ deletion conferred protection. Acute pH correction caused no injury to continuously oxygenated PTSs. Conclusions are as follows: 1) Posthypoxic "pH shock" causes virtually immediate cell death, not by causing de novo injury but, rather, by removing the cytoprotective effect of acidosis. 2) This injury can be prevented by a

  20. Characteristics of salt and water transport in superficial and juxtamedullary straight segments of proximal tubules.

    PubMed Central

    Kawamura, S; Imai, M; Seldin, D W; Kukko, J P

    1975-01-01

    The purpose of the present studies was to characterize the nature of salt and water transport out of the superficial (SF) and juxtamedullary (JM) straight segments of rabbit proximal tubules as examined by in vitro microperfusion techniques. When the perfusate consisted of a solution simulating ultrafiltrate of plasma, there were no differences between SF and JM straight tubules in either net reabsorption of fluid (SF=0.47 nl/mm per min; JM=0.56 nl/mm per min) or in transtubular potential difference (PD) (SF=-2.1 mV; JM=-1.8 mV). Removal of glucose and alanine from the perfusate had no effect on the magnitude of the PD in either straight segment. Ouabain decreased both the net reabsorptive rates and the PD. Isosmolal replacement of NaCL by Na-cyclamate (a presumed impermeant anion) in the perfusate and the bath caused an increase in luminal negativity in both segments wheras similar substitution of NaCL by choline-CL (nontransported cation) changed the PD TO NEAR ZERO. These studies, therefore, suggest that sodium is transported out of the proximal straight tubules by an active noncoupled process that generates a PD (electrogenic process). When the perfusate consisted of a solution with a high chloride concentration (resulting from greater HCO3 than CI reabsorption in the proximal convoluted tubule), different PDs in SF and JM tubules were generated: SF=+1.6 plus or minus 0.2 mV; JM=-1.3 plus or minus 0.3 mV. This difference in PD was attributed to relative differences in Na and CI permeabilities in these two segments. Electrophysiological and isotopic estimates of the chloride to sodium permeability revealed that the SF tubule is about twice as permeant to chloride than to sodium whereas the JM tubules are approximately twice as permeant to sodium than to chloride. It is concluded that the mechanism of active sodium transport in the straight segment of proximal tubule differs from that of the convoluted segment and that both the SF and JM straight segments differ

  1. Vaccination Rates are Associated With Functional Proximity But Not Base Proximity of Vaccination Clinics

    PubMed Central

    Beshears, John; Choi, James J.; Laibson, David I.; Madrian, Brigitte C.

    2016-01-01

    Background: Routine annual influenza vaccinations are recommended for persons 6 months of age and older, but less than half of US adults get vaccinated. Many employers offer employees free influenza vaccinations at workplace clinics, but even then take-up is low. Objective: To determine whether employees are significantly more likely to get vaccinated if they have a higher probability of walking by the clinic for reasons other than vaccination. Method: We obtained data from an employer with a free workplace influenza vaccination clinic. Using each employee’s building entry/exit swipe card data, we test whether functional proximity—the likelihood that the employee walks by the clinic for reasons other than vaccination—predicts whether the employee gets vaccinated at the clinic. We also test whether base proximity—the inverse of walking distance from the employee’s desk to the clinic—predicts vaccination probability. Participants: A total of 1801 employees of a health benefits administrator that held a free workplace influenza vaccination clinic. Results: A 2 SD increase in functional proximity is associated with a 6.4 percentage point increase in the probability of vaccination (total vaccination rate at company=40%), even though the average employee’s desk is only 166 meters from the clinic. Base proximity does not predict vaccination probability. Conclusions and Relevance: Minor changes in the environment can have substantial effects on the probability of vaccination. If these results generalize, health systems should emphasize functional proximity over base proximity when locating preventive health services. PMID:27177295

  2. Proximity Operations and Docking Sensor Development

    NASA Technical Reports Server (NTRS)

    Howard, Richard T.; Bryan, Thomas C.; Brewster, Linda L.; Lee, James E.

    2009-01-01

    The Next Generation Advanced Video Guidance Sensor (NGAVGS) has been under development for the last three years as a long-range proximity operations and docking sensor for use in an Automated Rendezvous and Docking (AR&D) system. The first autonomous rendezvous and docking in the history of the U.S. Space Program was successfully accomplished by Orbital Express, using the Advanced Video Guidance Sensor (AVGS) as the primary docking sensor. That flight proved that the United States now has a mature and flight proven sensor technology for supporting Crew Exploration Vehicles (CEV) and Commercial Orbital Transport Systems (COTS) Automated Rendezvous and Docking (AR&D). NASA video sensors have worked well in the past: the AVGS used on the Demonstration of Autonomous Rendezvous Technology (DART) mission operated successfully in spot mode out to 2 km, and the first generation rendezvous and docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on Space Shuttle flights in 1997 and 1998. 12 Parts obsolescence issues prevent the construction of more AVGS units, and the next generation sensor was updated to allow it to support the CEV and COTS programs. The flight proven AR&D sensor has been redesigned to update parts and add additional capabilities for CEV and COTS with the development of the Next Generation AVGS at the Marshall Space Flight Center. The obsolete imager and processor are being replaced with new radiation tolerant parts. In addition, new capabilities include greater sensor range, auto ranging capability, and real-time video output. This paper presents some sensor hardware trades, use of highly integrated laser components, and addresses the needs of future vehicles that may rendezvous and dock with the International Space Station (ISS) and other Constellation vehicles. It also discusses approaches for upgrading AVGS to address parts obsolescence, and concepts for minimizing the sensor footprint, weight, and power requirements

  3. Ejecta emplacement: from distal to proximal

    NASA Astrophysics Data System (ADS)

    Artemieva, N.

    2008-09-01

    Introduction Most part of impact ejecta is deposited ballistically at some distance from a crater, defined by ejection velocity V and ejection angle α: d=v2sinα/g. In case of giant impacts, planetary curvature should be taken into account [1]. Combined with ejecta scaling [2], these relations allow to define ejecta thickness as a function of distance. Ejecta from large craters are deposited at velocity high enough to mobilize substrate material and to thicken ejecta deposits [3]. Ballistic approximation is valid for airless bodies (if impact vaporization is not vast) or for proximal ejecta of large impact craters, where ejecta mass per unit area is substantially greater than the mass of involved vapor/atmosphere (M-ratio). Deposition of distal ejecta, in which ejecta mass is negligible compared to the atmosphere, may be also treated in a simplified manner, i.e. as 1) passive motion of ejected particles within an impact plume and 2) later, as sedimentation of particles in undisturbed atmosphere (equilibrium between gravity and drag). In all intermediate M-ratio values, impact ejecta move like a surge, i.e. dilute suspension current in which particles are carried in turbulent flows under the influence of gravity. Surges are well-known for near-surface explosive tests, described in detail for volcanic explosions (Plinian column collapse, phreato-magmatic eruption, lateral blast), and found in ejecta from the Chicxulub [4] and the Ries [5]. Important aspects of surge transport include its ability to deposit ejecta over a larger area than that typical of continuous ballistic ejecta and to create multiple ejecta layers. Numerical model Two-phase hydrodynamics. Surges should be modeled in the frame of two-phase hydrodynamics, i.e. interaction between solid/molten particles and atmospheric gas/impact vapor should be taken into account. There are two techniques of solving equations for dust particle motion in a gas flow. The first one describes solid/molten particles as a

  4. Verification of optical proximity effect in immersion lithography

    NASA Astrophysics Data System (ADS)

    Suganaga, Toshifumi; Maejima, Shinroku; Hanawa, Tetsuro; Ishibashi, Takeo; Nakao, Shuji; Shirai, Seiichiro; Narimatsu, Koichiro; Suko, Kazuyuki; Shiraishi, Kenichi; Ishii, Yuki; Ando, Tomoyuki; Ohmori, Katsumi

    2006-03-01

    193 nm lithography is one of the most promising technologies for next-generation lithography and is being actively evaluated for making it practicable (1,2). First, we evaluated an immersion lithography tool (engineering evaluation tool (EET)) (3) and a dry lithography tool (S307E) with the same numerical aperture (NA = 0.85), manufactured by Nikon Corporation. As a result, an increase in the depth of focus (DOF) of the EET to 200 nm in comparison with the DOF (110 nm) of the dry exposure tool was confirmed in a 90 nm isolated space pattern. Next, the optical proximity effect (OPE) in this pattern was evaluated. Generally, when an immersion lithography tool is compared with a dry one with the same NA or both the tools, only an increase in the DOF is found. However, we confirmed that the OPE (The OPE of the 90 nm isolated space pattern is defined as the difference in the space width between a dense space and an isolated space.) of the dry exposure tool for the 90 nm isolated space pattern reduced from 33.1 nm to 14.1 nm by immersion lithography. As the effect of the reduction of 19 nm, the OPE reduced to 15.2 nm by the effect of the top coatings (TCs) and to 3.8 nm by the optical characteristics. An impact of about 5 nm on the OPE was confirmed by the process parameters-film thickness and the pre-bake temperature of the TC. In the case that the solvent was replaced with a high boiling point solvent, the impact changed from 5 to 20 nm further, the replacement of the solvent had a considerable impact on the OPE. However, this influence differs considerably according to the kind of resists; further, it was shown that the addition of acid materials and a change in the polymer base resulted in a high impact on the OPE for a certain resist. Thus, it was demonstrated that the selection of TC is very important for the OPE in immersion lithography.

  5. Morphometry of Proximal Femur in Indian Population

    PubMed Central

    Joshi, Sheetal; Tuli, Anita; Raheja, Shashi; Jain, Priyanka; Srivastava, Priyanka

    2017-01-01

    Introduction Total hip arthroplasty is a commonly performed surgery now-a-day. There are regional and racial variations in the stature of the population worldwide. So there is always need of population specific data for making best fit prosthesis. Aim The present study was done to measure the parameters of proximal femur and to analyse their correlation by using standard statistical analysis. Materials and Methods Ninety one dry bones (44 left and 47 right) were used. Femur Head Diameter (FHD), Femur Neck Length (FNL), Femur Neck Diameter (FND), Femur Neck Thickness (FNT), Cervicodiaphyseal Angle (CDA) was directly measured with the help of anthropometric instruments. Femur Head Offset (FHO) and Vertical Offset (VO) were measured in the anteroposterior digital photographs. Results Normally distributed variables were compared using Student’s t-test (Unpaired data) to analyse significant effect. There was a significant difference between right and left side of FND and CDA. Pearson correlation coefficient was used to analyse the relationship among variables. FHO had high correlation with the VO (0.687, p<0.001). Conclusion These parameters can be used for designing the prosthesis and plates for hip joint reconstructive surgeries suitable for Indian population. PMID:28384844

  6. Proximity Navigation of Highly Constrained Spacecraft

    NASA Technical Reports Server (NTRS)

    Scarritt, S.; Swartwout, M.

    2007-01-01

    Bandit is a 3-kg automated spacecraft in development at Washington University in St. Louis. Bandit's primary mission is to demonstrate proximity navigation, including docking, around a 25-kg student-built host spacecraft. However, because of extreme constraints in mass, power and volume, traditional sensing and actuation methods are not available. In particular, Bandit carries only 8 fixed-magnitude cold-gas thrusters to control its 6 DOF motion. Bandit lacks true inertial sensing, and the ability to sense position relative to the host has error bounds that approach the size of the Bandit itself. Some of the navigation problems are addressed through an extremely robust, error-tolerant soft dock. In addition, we have identified a control methodology that performs well in this constrained environment: behavior-based velocity potential functions, which use a minimum-seeking method similar to Lyapunov functions. We have also adapted the discrete Kalman filter for use on Bandit for position estimation and have developed a similar measurement vs. propagation weighting algorithm for attitude estimation. This paper provides an overview of Bandit and describes the control and estimation approach. Results using our 6DOF flight simulator are provided, demonstrating that these methods show promise for flight use.

  7. Proximal Row Carpectomy Combined with Wrist Hemiarthroplasty

    PubMed Central

    Culp, Randall W.; Bachoura, Abdo; Gelman, Scott E.; Jacoby, Sidney M.

    2012-01-01

    Proximal row carpectomy (PRC) combined with distal radius hemiarthroplasty is a relatively novel procedure that rivals total wrist arthrodesis and offers a new surgical treatment option for select patients with painful, end-stage wrist disease. We present our early experience with this procedure. A retrospective chart review was conducted for nonrheumatoid patients diagnosed with wrist arthritis and subsequently treated with wrist hemiarthroplasty combined with PRC. The minimum follow-up duration was 12 months. Preoperative and postoperative flexion, extension, and grip strength were recorded. Postoperative radiographic findings were assessed. The Patient-Rated Wrist Evaluation (PRWE) questionnaire was administered to gauge postoperative pain and function. The records of 10 patients were reviewed. The mean age was 64 years and the mean postoperative follow-up duration was 19 months. Postoperative flexion, extension, and grip strength were all found to be less than the preoperative levels. The mean postoperative PRWE score for pain and function were 26 and 23, respectively. The complications were diverse and occurred at a relatively high rate. PRC combined with distal radius hemiarthroplasty is a novel procedure that offers a potential surgical option for the treatment of wrist arthritis in select patients. Our early experience has lead us to modify our technique with regard to the implant material, and at this stage, the surgical technique and the most appropriate implant may require further optimization. The level of evidence for this study is IV (therapeutic). PMID:23904978

  8. Distal radius fracture after proximal row carpectomy

    PubMed Central

    Igeta, Yuka; Naito, Kiyohito; Sugiyama, Yoichi; Obata, Hiroyuki; Aritomi, Kentaro; Kaneko, Kazuo; Obayashi, Osamu

    2015-01-01

    Introduction We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report. Presentation of case The patient was a 73-year-old female who had undergone PRC due to Kienböck disease before. The wrist range of motion was: 45° on dorsiflexion and 20° on flexion. DRF has occurred at 3 years after PRC. The fracture type was extra-articular fracture. Osteosynthesis was performed using a volar locking plate. No postoperative complication developed, the Mayo score was excellent at 6 months after surgery, and the daily living activity level recovered to that before injury. Discussion Since the wrist range of motion decreased and the lunate fitted into the joint surface after PRC, making the forearm join with the hand like a single structure, pressure may have been loaded on the weak distal end of the radius from the dorsal side, causing volar displacement and fracture. Conclusion The pressure distribution and range of motion of the radiocarpal joint after PRC are different from those of a normal joint, and the mechanism of fracture also changes due to PRC. PMID:25623755

  9. Semiconductor detectors with proximity signal readout

    SciTech Connect

    Asztalos, Stephen J.

    2014-01-30

    Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need.

  10. Proximity Resonance and Localized Surface Plasmons

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Heller, Eric

    2014-03-01

    The collective excitation of conduction electrons in subwavelength nanostructures is known as Localized Surface Plasmon(LSP)[1]. Such plasmon modes has been intensively studied using noble nanoparticles . More recently, the possibility of building terahertz metamaterials supporting such LSP modes has been explored in graphene microribbons and microdisks. Unlike Surface Plasmon Polaritons(SPPs) at metal-insulator interface, LSP can be directly excited by light illumination and holds promise for applications in ultrasensitive biosensing, nano-optical tweezers and improved photovoltaic devices. In this paper, we consider the interaction of two LSPs in the weak coupling regime and show how an effect similar to the proximity resonance in the quantum scattering theory) gives rise to an asymmetric(quadrupole) mode with increased damping rate. The existence of this asymmetric mode relies on a small phase retardation between the two LSPs. This phase retardation, though small, is key to both increased damping rate for the asymmetric mode and reduced damping rate for the symmetric mode. When this small phase retardation is removed by changing the polarization of the exciting light,we show that the asymmetric mode can not be excited and the symmetric mode shows increased damping.

  11. Effective proximity retrieval by ordering permutations.

    PubMed

    Chavez, Edgar; Figueroa, Karina; Navarro, Gonzalo

    2008-09-01

    We introduce a new probabilistic proximity search algorithm for range and K-nearest neighbor (K-NN) searching in both coordinate and metric spaces. Although there exist solutions for these problems, they boil down to a linear scan when the space is intrinsically high-dimensional, as is the case in many pattern recognition tasks. This, for example, renders the K-NN approach to classification rather slow in large databases. Our novel idea is to predict closeness between elements according to how they order their distances towards a distinguished set of anchor objects. Each element in the space sorts the anchor objects from closest to farthest to it, and the similarity between orders turns out to be an excellent predictor of the closeness between the corresponding elements. We present extensive experiments comparing our method against state-of-the-art exact and approximate techniques, both in synthetic and real, metric and non-metric databases, measuring both CPU time and distance computations. The experiments demonstrate that our technique almost always improves upon the performance of alternative techniques, in some cases by a wide margin.

  12. Ranging/tracking system for proximity operations

    NASA Technical Reports Server (NTRS)

    Nilsen, P.; Udalov, S.

    1982-01-01

    The hardware development and testing phase of a hand held radar for the ranging and tracking for Shuttle proximity operations are considered. The radar is to measure range to a 3 sigma accuracy of 1 m (3.28 ft) to a maximum range of 1850 m (6000 ft) and velocity to a 3 sigma accuracy of 0.03 m/s (0.1 ft/s). Size and weight are similar to hand held radars, frequently seen in use by motorcycle police officers. Meeting these goals for a target in free space was very difficult to obtain in the testing program; however, at a range of approximately 700 m, the 3 sigma range error was found to be 0.96 m. It is felt that much of this error is due to clutter in the test environment. As an example of the velocity accuracy, at a range of 450 m, a 3 sigma velocity error of 0.02 m/s was measured. The principles of the radar and recommended changes to its design are given. Analyses performed in support of the design process, the actual circuit diagrams, and the software listing are included.

  13. Effects of thrust reversing in ground proximity

    NASA Technical Reports Server (NTRS)

    Joshi, P. B.; Hughes, R. V.

    1987-01-01

    The changes in stability and control characteristics encountered by a thrust reversing aircraft during its final approach, landing, and ground roll are described. These changes include a strong pitch-up accompanied by the loss of horizontal tail and aileron control effectiveness. The magnitude of reverser induced changes in ground effect are much larger than corresponding changes in free air. Some unexpected unsteady motions exhibited in wind tunnel by an aircraft model with reversers operating in ground proximity are also described. The cause of this oscillatory behavior was determined to be an unsteady interaction between the wall jets formed by impingement of reverser jets on the ground and the on-coming free stream. Time histories of rolling moments measured by the wind tunnel balance or support system were removed and frequencies were scaled by Strouhal number to full scale. Corrected time series were used to simulate the motion of a fighter aircraft with thrust reversers in ground effect. The simulation predicted large roll angles and nose down attitude at touchdown. Some phenomena of jet attachment to solid surfaces are discussed and areas for future research are recommended.

  14. Proximity effects in cold atom artificial graphene

    NASA Astrophysics Data System (ADS)

    Graß, Tobias; Chhajlany, Ravindra W.; Tarruell, Leticia; Pellegrini, Vittorio; Lewenstein, Maciej

    2017-03-01

    Cold atoms in an optical lattice with brick-wall geometry have been used to mimic graphene, a two-dimensional material with characteristic Dirac excitations. Here we propose to bring such artificial graphene into the proximity of a second atomic layer with a square lattice geometry. For non-interacting fermions, we find that such bilayer system undergoes a phase transition from a graphene-like semi-metal phase, characterized by a band structure with Dirac points, to a gapped band insulator phase. In the presence of attractive interactions between fermions with pseudospin-1/2 degree of freedom, a competition between semi-metal and superfluid behavior is found at the mean-field level. Using the quantum Monte Carlo method, we also investigate the case of strong repulsive interactions. In the Mott phase, each layer exhibits a different amount of long-range magnetic order. Upon coupling both layers, a valence-bond crystal is formed at a critical coupling strength. Finally, we discuss how these bilayer systems could be realized in existing cold atom experiments.

  15. Interactive orbital proximity operations planning system

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1989-01-01

    An interactive, graphical proximity operations planning system was developed which allows on-site design of efficient, complex, multiburn maneuvers in the dynamic multispacecraft environment about the space station. Maneuvering takes place in, as well as out of, the orbital plane. The difficulty in planning such missions results from the unusual and counterintuitive character of relative orbital motion trajectories and complex operational constraints, which are both time varying and highly dependent on the mission scenario. This difficulty is greatly overcome by visualizing the relative trajectories and the relative constraints in an easily interpretable, graphical format, which provides the operator with immediate feedback on design actions. The display shows a perspective bird's-eye view of the space station and co-orbiting spacecraft on the background of the station's orbital plane. The operator has control over two modes of operation: (1) a viewing system mode, which enables him or her to explore the spatial situation about the space station and thus choose and frame in on areas of interest; and (2) a trajectory design mode, which allows the interactive editing of a series of way-points and maneuvering burns to obtain a trajectory which complies with all operational constraints. Through a graphical interactive process, the operator will continue to modify the trajectory design until all operational constraints are met. The effectiveness of this display format in complex trajectory design is presently being evaluated in an ongoing experimental program.

  16. Interactive orbital proximity operations planning system

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1988-01-01

    An interactive graphical proximity operations planning system was developed, which allows on-site design of efficient, complex, multiburn maneuvers in a dynamic multispacecraft environment. Maneuvering takes place in and out of the orbital plane. The difficulty in planning such missions results from the unusual and counterintuitive character of orbital dynamics and complex time-varying operational constraints. This difficulty is greatly overcome by visualizing the relative trajectories and the relevant constraints in an easily interpretable graphical format, which provides the operator with immediate feedback on design actions. The display shows a perspective bird's-eye view of a Space Station and co-orbiting spacecraft on the background of the Station's orbital plane. The operator has control over the two modes of operation: a viewing system mode, which enables the exporation of the spatial situation about the Space Station and thus the ability to choose and zoom in on areas of interest; and a trajectory design mode, which allows the interactive editing of a series of way points and maneuvering burns to obtain a trajectory that complies with all operational constraints. A first version of this display was completed. An experimental program is planned in which operators will carry out a series of design missions which vary in complexity and constraints.

  17. The Proximal Tubule and Albuminuria: Really!

    PubMed Central

    Dickson, Landon E.; Wagner, Mark C.; Sandoval, Ruben M.

    2014-01-01

    Recent data highlight the role of the proximal tubule (PT) in reabsorbing, processing, and transcytosing urinary albumin from the glomerular filtrate. Innovative techniques and approaches have provided exciting insights into these processes, and numerous investigators have shown that selective PT cell defects lead to significant albuminuria, even reaching nephrotic range in animal models. Thus, the mechanisms of albumin reabsorption and transcytosis are undergoing intense study. Working in concert with megalin and cubilin, a nonselective multireceptor complex that predominantly directs proteins for lysosomal degradation, the neonatal Fc receptor (FcRn) located at the brush border of the apical membrane has been implicated as the “receptor” mediating albumin transcytosis. The FcRn pathway facilitates reabsorption and mediates transcytosis by its pH-dependent binding affinity in endosomal compartments. This also allows for selective albumin sorting within the PT cell. This reclamation pathway minimizes urinary losses and catabolism of albumin, thus prolonging its serum half-life. It may also serve as a molecular sorter to preserve and reclaim normal albumin while allowing “altered” albumin to be catabolized via lysosomal pathways. Here, we critically review the data supporting this novel mechanism. PMID:24408874

  18. Analysis of pattern density on process proximity compensation

    NASA Astrophysics Data System (ADS)

    Jung, Sunwook; Lo, Fred; Yang, Tien-Chu; Yang, Ta-Hong; Chen, Kuang-Chao; Lu, Chih-Yuan

    2007-03-01

    The challenges of ever-smaller CD (Critical Dimension) budget for advanced memory product requires tight ACLV (Across-Chip Line-width Variation) control. In addition to the lithographic MOPC (Model-based Optical Proximity Correction) for DCD (photo CD) control, the process correction for etch proximity effect can no longer be ignored. To meet on our requirement on final CD accuracy for critical layer, a set of test pattern, that represents memory array in one of our critical layers, has been generated for both photo and etch process characterizations. Through the combination of different pattern-coverage areas in the test mask and wafer map design, various local (chip-level) pattern densities of 40%~70% and global (wafer-level) pattern densities of 35%~65% were achieved for optical and etch proximity study. The key contributors to the process proximity effect were identified and voluminous data has been extracted from the memory block like patterns for statistical analysis. The photo and etch proximity effects were hence modeled as function of memory block separation, local pattern density as well as global pattern density. Finally, the respective photo and etch proximity effects through model-based proximity correction and rule-based proximity correction were applied in a multi-step flow to products.

  19. Wrist level and proximal-upper extremity replantation.

    PubMed

    Hanel, Douglas P; Chin, Simon H

    2007-02-01

    Since Malt and McKhan's first successful arm replantation in 1962, upper extremity replantation surgery techniques have been refined and spread worldwide. Nevertheless, replantation at or proximal to the wrist, referred to as wrist-proximal replants, remains a daunting challenge that presents the hand surgeon with an array of difficulties distinct from digital replantation.

  20. Proximal and distal muscle fatigue differentially affect movement coordination

    PubMed Central

    Cowley, Jeffrey C.

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005) in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005), and increased elbow flexion (4°, p < 0.01). In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05), increased velocity of wrench movement relative to the hand (17°/s, p < 0.001), and earlier wrist extension (4%, p < 0.005). Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05). Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks. PMID:28235005

  1. Comparative studies for different proximity potentials applied to α decay

    NASA Astrophysics Data System (ADS)

    Yao, Y. J.; Zhang, G. L.; Qu, W. W.; Qian, J. Q.

    2015-09-01

    Half-lives of α decay of even-even nuclei calculated by using fourteen different versions of proximity potentials are compared to experimental data. The results show that the results of the generalized proximity potential 1977 are very much in agreement with the experimental data. In comparison with the distributions of nuclear potentials at small distances and the distributions of total potentials above the released energy Q α , it is found that at small distances the distributions of nuclear potentials have large difference and the distributions of total potentials are different among the listed proximity potentials. The different potential distributions affect the penetration probability of α, which is related to the half-life of the α decay for each nucleus. The generalized proximity potential 1977 is also used to calculate the half-lives of α decay of nuclei with odd mass numbers. The results show that the generalized proximity potential 1977 can calculate the half-lives of the α decay of almost all nuclei, which underlines and supports the use of the generalized proximity potential 1977 by Santhosh et al. in the Coulomb and proximity potential model (CPPM) and the Coulomb and proximity potential model for deformed nuclei (CPPMDN).

  2. Characterisation of human tubular cell monolayers as a model of proximal tubular xenobiotic handling

    SciTech Connect

    Brown, Colin D.A. Sayer, Rachel; Windass, Amy S.; Haslam, Iain S.; Broe, Marc E. de; D'Haese, Patrick C.; Verhulst, Anja

    2008-12-15

    The aim of this study was to determine whether primary human tubular cell monolayers could provide a powerful tool with which to investigate the renal proximal tubular handling of xenobiotics. Human proximal and distal tubule/collecting duct cells were grown as monolayers on permeable filter supports. After 10 days in culture, proximal tubule cells remained differentiated and expressed a wide palette of transporters at the mRNA level including NaPi-IIa, SGLT1, SGLT2, OCT2, OCTN2, OAT1, OAT3, OAT4, MDR1, MRP2 and BCRP. At the protein level, the expression of a subset of transporters including NaPi-IIa, OAT1 and OAT3 was demonstrated using immunohistochemistry. Analysis of the expression of the ATP binding cassette efflux pumps MDR1, MRP2 and BCRP confirmed their apical membrane localisation. At the functional level, tubule cell monolayers retain the necessary machinery to mediate the net secretion of the prototypic substrates; PAH and creatinine. PAH secretion across the monolayer consisted of the uptake of PAH across the basolateral membrane by OAT1 and OAT3 and the apical exit of PAH by a probenecid and MK571-sensitive route consistent with actions of MRP2 or MRP4. Creatinine secretion was by OCT2-mediated uptake at the basolateral membrane and via MDR1 at the apical membrane. Functional expression of MDR1 and BCRP at the apical membrane was also demonstrated using a Hoechst 33342 dye. Similarly, measurement of calcein efflux demonstrated the functional expression of MRP2 at the apical membrane of cell monolayers. In conclusion, human tubular cell monolayers provide a powerful tool to investigate renal xenobiotic handling.

  3. The COOH terminus of megalin regulates gene expression in opossum kidney proximal tubule cells

    PubMed Central

    Li, Yuanli; Cong, Rong; Biemesderfer, Daniel

    2008-01-01

    We recently reported that megalin is subjected to regulated intramembrane proteolysis (RIP) and includes 1) protein kinase C (PKC)-regulated, metalloprotease-mediated ectodomain shedding producing a membrane-bound megalin COOH-terminal fragment (MCTF) and 2) γ-secretase-mediated cleavage of the MCTF producing a soluble megalin intracellular domain (MICD). Based on studies of RIP of other receptors, the MICD is predicted to target to the nucleus and regulate gene expression. To determine whether RIP of megalin regulates proximal tubule gene expression, we stably expressed the transfected MCTF (tMCTF) or transfected MICD (tMICD) in opossum kidney proximal tubule (OKP) cells and examined the resulting phenotype. Immunoblotting and immunocytochemical analysis of tMCTF cells showed the tMCTF was expressed and constitutively processed by γ-secretase. Analysis of specific protein expression in tMCTF- and tMICD-transfected cells using Western blot showed endogenous megalin and Na+/H+ exchanger 3 (NHE3) protein expression to be dramatically lower than that of control cells. Expression of other proteins including myosin VI, β-adaptin, and the Na-K-ATPase appeared unchanged. Analysis of specific mRNA expression using quantitative real-time PCR showed megalin and NHE3 mRNA levels were significantly lower in tMCTF- and tMICD-transfected cells compared with controls. Inhibition of γ-secretase activity in tMCTF cells resulted in an 8- to 10-fold recovery of megalin mRNA within 4 h. These data show that the COOH-terminal domain of megalin regulates expression of specific proteins in OKP cells and provides the first evidence that RIP of megalin may be part of a signaling pathway linking protein absorption and gene expression in proximal tubule. PMID:18495814

  4. Hypospadias and Residential Proximity to Pesticide Applications

    PubMed Central

    Yang, Wei; Roberts, Eric M.; Kegley, Susan E.; Wolff, Craig; Guo, Liang; Lammer, Edward J.; English, Paul; Shaw, Gary M.

    2013-01-01

    BACKGROUND: Experimental evidence suggests pesticides may be associated with hypospadias. OBJECTIVE: Examine the association of hypospadias with residential proximity to commercial agricultural pesticide applications. METHODS: The study population included male infants born from 1991 to 2004 to mothers residing in 8 California counties. Cases (n = 690) were ascertained by the California Birth Defects Monitoring Program; controls were selected randomly from the birth population (n = 2195). We determined early pregnancy exposure to pesticide applications within a 500-m radius of mother’s residential address, using detailed data on applications and land use. Associations with exposures to physicochemical groups of pesticides and specific chemicals were assessed using logistic regression adjusted for maternal race or ethnicity and age and infant birth year. RESULTS: Forty-one percent of cases and controls were classified as exposed to 57 chemical groups and 292 chemicals. Despite >500 statistical comparisons, there were few elevated odds ratios with confidence intervals that excluded 1 for chemical groups or specific chemicals. Those that did were for monochlorophenoxy acid or ester herbicides; the insecticides aldicarb, dimethoate, phorate, and petroleum oils; and adjuvant polyoxyethylene sorbitol among all cases; 2,6-dinitroaniline herbicides, the herbicide oxyfluorfen, and the fungicide copper sulfate among mild cases; and chloroacetanilide herbicides, polyalkyloxy compounds used as adjuvants, the insecticides aldicarb and acephate, and the adjuvant nonyl-phenoxy-poly(ethylene oxy)ethanol among moderate and severe cases. Odds ratios ranged from 1.9 to 2.9. CONCLUSIONS: Most pesticides were not associated with elevated hypospadias risk. For the few that were associated, results should be interpreted with caution until replicated in other study populations. PMID:24167181

  5. Interactive orbital proximity operations planning system

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1990-01-01

    An interactive graphical planning system for on-site planning of proximity operations in the congested multispacecraft environment about the space station is presented. The system shows the astronaut a bird's eye perspective of the space station, the orbital plane, and the co-orbiting spacecraft. The system operates in two operational modes: (1) a viewpoint mode, in which the astronaut is able to move the viewpoint around in the orbital plane to range in on areas of interest; and (2) a trajectory design mode, in which the trajectory is planned. Trajectory design involves the composition of a set of waypoints which result in a fuel-optimal trajectory which satisfies all operational constraints, such as departure and arrival constraints, plume impingement constraints, and structural constraints. The main purpose of the system is to present the trajectory and the constraints in an easily interpretable graphical format. Through a graphical interactive process, the trajectory waypoints are edited until all operational constraints are satisfied. A series of experiments was conducted to evaluate the system. Eight airline pilots with no prior background in orbital mechanics participated in the experiments. Subject training included a stand-alone training session of about 6 hours duration, in which the subjects became familiar with orbital mechanics concepts and performed a series of exercises to familiarize themselves with the control and display features of the system. They then carried out a series of production runs in which 90 different trajectory design situations were randomly addressed. The purpose of these experiments was to investigate how the planning time, planning efforts, and fuel expenditures were affected by the planning difficulty. Some results of these experiments are presented.

  6. Nanocrystal Bioassembly: Asymmetry, Proximity, and Enzymatic Manipulation

    SciTech Connect

    Claridge, Shelley A.

    2008-05-01

    Research at the interface between biomolecules and inorganic nanocrystals has resulted in a great number of new discoveries. In part this arises from the synergistic duality of the system: biomolecules may act as self-assembly agents for organizing inorganic nanocrystals into functional materials; alternatively, nanocrystals may act as microscopic or spectroscopic labels for elucidating the behavior of complex biomolecular systems. However, success in either of these functions relies heavily uponthe ability to control the conjugation and assembly processes.In the work presented here, we first design a branched DNA scaffold which allows hybridization of DNA-nanocrystal monoconjugates to form discrete assemblies. Importantly, the asymmetry of the branched scaffold allows the formation of asymmetric2assemblies of nanocrystals. In the context of a self-assembled device, this can be considered a step toward the ability to engineer functionally distinct inputs and outputs.Next we develop an anion-exchange high performance liquid chromatography purification method which allows large gold nanocrystals attached to single strands of very short DNA to be purified. When two such complementary conjugates are hybridized, the large nanocrystals are brought into close proximity, allowing their plasmon resonances to couple. Such plasmon-coupled constructs are of interest both as optical interconnects for nanoscale devices and as `plasmon ruler? biomolecular probes.We then present an enzymatic ligation strategy for creating multi-nanoparticle building blocks for self-assembly. In constructing a nanoscale device, such a strategy would allow pre-assembly and purification of components; these constructs can also act as multi-label probes of single-stranded DNA conformational dynamics. Finally we demonstrate a simple proof-of-concept of a nanoparticle analog of the polymerase chain reaction.

  7. Proximal humeral reconstruction using nail cement spacer in primary and metastatic tumours of proximal humerus.

    PubMed

    Kundu, Zile Singh; Gogna, Paritosh; Gupta, Vinay; Kamboj, Pradeep; Singla, Rohit; Sangwan, Sukhbir Singh

    2013-11-01

    Limb salvage surgery for malignant tumours of proximal humerus is an operative challenge, where the surgeon has to preserve elbow and hand functions and retain shoulder stability with as much function as possible. We treated 14 consecutive patients with primary malignant or isolated metastasis of proximal humerus with surgical resection and reconstruction by nail cement spacer. There were 8 females and 6 males, with a mean age of 28.92 years (range 16-51 years) and a mean follow-up of 30.14 months (range 12-52 months). The diagnosis was osteosarcoma in 8 patients, chondrosarcoma in 4 patients and metastasis from thyroid and breast carcinoma in 1 patient each. One of our patients had radial nerve neuropraxia, 1 developed inferior subluxation and 3 developed distant metastasis. Two patients died of disease and one developed local recurrence leading to forequarter amputation, leaving a total of 11 patients with functional extremities for assessment at the time of final follow-up which was done using the Musculoskeletal Tumour Society (MSTS) score. Though we were able to preserve the elbow, wrist and hand functions in all patients, the abductor mechanism, deltoid muscle and axillary nerve were not salvageable in any of cases. The mean MSTS score at the time of final follow-up was 19.09. Thus, proximal humeral reconstruction using nail cement spacer is a technical simple, cost-effective and reproducible procedure which makes it a reliable option in subset of patients where the functions around the shoulder cannot be preserved despite costlier prosthesis.

  8. Local pH domains regulate NHE3-mediated Na⁺ reabsorption in the renal proximal tubule.

    PubMed

    Brasen, Jens Christian; Burford, James L; McDonough, Alicia A; Holstein-Rathlou, Niels-Henrik; Peti-Peterdi, Janos

    2014-12-01

    The proximal tubule Na(+)/H(+) exchanger 3 (NHE3), located in the apical dense microvilli (brush border), plays a major role in the reabsorption of NaCl and water in the renal proximal tubule. In response to a rise in blood pressure NHE3 redistributes in the plane of the plasma membrane to the base of the brush border, where NHE3 activity is reduced. This NHE3 redistribution is assumed to provoke pressure natriuresis; however, it is unclear how NHE3 redistribution per se reduces NHE3 activity. To investigate if the distribution of NHE3 in the brush border can change the reabsorption rate, we constructed a spatiotemporal mathematical model of NHE3-mediated Na(+) reabsorption across a proximal tubule cell and compared the model results with in vivo experiments in rats. The model predicts that when NHE3 is localized exclusively at the base of the brush border, it creates local pH microdomains that reduce NHE3 activity by >30%. We tested the model's prediction experimentally: the rat kidney cortex was loaded with the pH-sensitive fluorescent dye BCECF, and cells of the proximal tubule were imaged in vivo using confocal fluorescence microscopy before and after an increase of blood pressure by ∼50 mmHg. The experimental results supported the model by demonstrating that a rise of blood pressure induces the development of pH microdomains near the bottom of the brush border. These local changes in pH reduce NHE3 activity, which may explain the pressure natriuresis response to NHE3 redistribution.

  9. Modeling tunneling for the unconventional superconducting proximity effect

    NASA Astrophysics Data System (ADS)

    Zareapour, Parisa; Xu, Jianwei; Zhao, Shu Yang F.; Jain, Achint; Xu, Zhijun; Liu, T. S.; Gu, G. D.; Burch, Kenneth S.

    2016-12-01

    Recently there has been reinvigorated interest in the superconducting proximity effect, driven by predictions of the emergence of Majorana fermions. To help guide this search, we have developed a phenomenological model for the tunneling spectra in anisotropic superconductor-normal metal proximity devices. We combine successful approaches used in s-wave proximity and standard d-wave tunneling to reproduce tunneling spectra in d-wave proximity devices, and clarify the origin of various features. Different variations of the pair potential are considered, resulting from the proximity-induced superconductivity. Furthermore, the effective pair potential felt by the quasiparticles is momentum-dependent in contrast to s-wave superconductors. The probabilities of reflection and transmission are calculated by solving the Bogoliubov equations. Our results are consistent with experimental observations of the unconventional proximity effect and provide important experimental parameters such as the size and length scale of the proximity induced gap, as well as the conditions needed to observe the reduced and full superconducting gaps.

  10. Non-Melanoma-Associated Dyschromia of the Proximal Nail Fold

    PubMed Central

    Cohen, Philip R

    2016-01-01

    Subungual melanoma with pigmentation beneath the nail that extends to involve the proximal nail fold is referred to as Hutchinson’s sign. Black or brown subungual discoloration involving the proximal nail fold secondary to other etiologies has been referred to as pseudo-Hutchinson’s sign. Three patients with nail discoloration and concurrent dyschromia of the proximal nail fold are described: a female with a chronic subungual hematoma and pseudo-Hutchinson’s sign, a male with culture-confirmed Pseudomonas aeruginosa (P. aeruginosa) of the nail with green discoloration involving the proximal nail fold, and a male with an acute subungual hematoma with red-purple subungual discoloration affecting the proximal nail fold. PubMed was searched for the following: black, brown, chloronychia, discoloration, dyschromia, green, hematoma, Hutchinson’s sign, nail, nail fold, proximal, pseudo-Hutchinson’s sign, red, subungual melanoma, syndrome. The papers were reviewed and appropriate references evaluated. In conclusion, melanoma-associated black proximal nail fold pigmentation is referred to as Hutchinson’s sign, and non-melanoma-associated black pigmentation has been designated as pseudo-Hutchinson’s sign. Subungual nail plate discoloration extending to involve the proximal nail fold may be black, green, or red-purple in patients with melanocytic and non-melanocytic lesions, bacterial infection (Pseudomonas), and acute subungual hematoma, respectively. Instead of creating a new terminology, we suggest that non-black subungual discoloration (green or red-purple) extending to involve the proximal nail fold be referred to as pseudo pseudo-Hutchinson’s sign. PMID:28090415

  11. Lipotoxic disruption of NHE1 interaction with PI(4,5)P2 expedites proximal tubule apoptosis.

    PubMed

    Khan, Shenaz; Abu Jawdeh, Bassam G; Goel, Monu; Schilling, William P; Parker, Mark D; Puchowicz, Michelle A; Yadav, Satya P; Harris, Raymond C; El-Meanawy, Ashraf; Hoshi, Malcolm; Shinlapawittayatorn, Krekwit; Deschênes, Isabelle; Ficker, Eckhard; Schelling, Jeffrey R

    2014-03-01

    Chronic kidney disease progression can be predicted based on the degree of tubular atrophy, which is the result of proximal tubule apoptosis. The Na+/H+ exchanger NHE1 regulates proximal tubule cell survival through interaction with phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], but pathophysiologic triggers for NHE1 inactivation are unknown. Because glomerular injury permits proximal tubule luminal exposure and reabsorption of fatty acid/albumin complexes, we hypothesized that accumulation of amphipathic, long-chain acyl-CoA (LC-CoA) metabolites stimulates lipoapoptosis by competing with the structurally similar PI(4,5)P2 for NHE1 binding. Kidneys from mouse models of progressive, albuminuric kidney disease exhibited increased fatty acids, LC-CoAs, and caspase-2-dependent proximal tubule lipoapoptosis. LC-CoAs and the cytosolic domain of NHE1 directly interacted, with an affinity comparable to that of the PI(4,5)P2-NHE1 interaction, and competing LC-CoAs disrupted binding of the NHE1 cytosolic tail to PI(4,5)P2. Inhibition of LC-CoA catabolism reduced NHE1 activity and enhanced apoptosis, whereas inhibition of proximal tubule LC-CoA generation preserved NHE1 activity and protected against apoptosis. Our data indicate that albuminuria/lipiduria enhances lipotoxin delivery to the proximal tubule and accumulation of LC-CoAs contributes to tubular atrophy by severing the NHE1-PI(4,5)P2 interaction, thereby lowering the apoptotic threshold. Furthermore, these data suggest that NHE1 functions as a metabolic sensor for lipotoxicity.

  12. Axillary artery injury as a complication of proximal humerus fractures.

    PubMed

    McLaughlin, J A; Light, R; Lustrin, I

    1998-01-01

    Proximal humerus fractures are common injuries and represent approximately 5% of all fractures. These fractures are infrequently associated with neurovascular injuries. Brachial plexus injuries are uncommon, whereas axillary artery injuries are rare. A review of 19 previously reported cases of axillary artery injury after proximal humerus fracture revealed that 84% occurred in patients older than 50 years, 53% were associated with brachial plexus injury, and 21% resulted in upper extremity amputation. This study describes a case of axillary artery injury after proximal humerus fracture and, on the basis of a literature review, offers suggestions for the early diagnosis and effective treatment of this uncommon injury.

  13. Light-operated proximity detector with linear output

    DOEpatents

    Simpson, Marc L.; McNeilly, David R.

    1985-01-01

    A light-operated proximity detector is described in which reflected light intensity from a surface whose proximity to the detector is to be gauged is translated directly into a signal proportional to the distance of the detector from the surface. A phototransistor is used to sense the reflected light and is connected in a detector circuit which maintains the phototransistor in a saturated state. A negative feedback arrangement using an operational amplifier connected between the collector and emitter of the transistor provides an output at the output of the amplifier which is linearly proportional to the proximity of the surface to the detector containing the transistor. This direct proportional conversion is true even though the light intensity is varying with the proximity in proportion to the square of the inverse of the distance. The detector may be used for measuring the distance remotely from any target surface.

  14. Light-operated proximity detector with linear output

    DOEpatents

    Simpson, M.L.; McNeilly, D.R.

    1984-01-01

    A light-operated proximity detector is described in which reflected light intensity from a surface whose proximity to the detector is to be gauged is translated directly into a signal proportional to the distance of the detector from the surface. A phototransistor is used to sense the reflected light and is connected in a detector circuit which maintains the phtotransistor in a saturated state. A negative feedback arrangement using an operational amplifier connected between the collector and emitter of the transistor provides an output at the output of the amplifier which is linearly proportional to the proximity of the surface to the detector containing the transistor. This direct proportional conversion is true even though the light intensity is varying with the proximity in proportion to the square of the inverse of the distance. The detector may be used for measuring the distance remotely from any target surface.

  15. An unusual case of glipizide-induced proximal myopathy

    PubMed Central

    Das, Saibal; Ramasamy, Anand; De, Soumyadip; Mondal, Somnath

    2016-01-01

    This case report outlines a very rare case of glipizide-induced severe proximal myopathy in a 61-year-old diabetic man. After taking 10 mg glipizide for 5 months, diabetes was well controlled but the patient presented with progressive proximal muscle weakness in all the four limbs. Clinical examination and relevant investigations suggested it to be a case of proximal myopathy and might be drug induced. De-challenge was done and was treated resulting in reversal of the diseased state. After 3 more months, controlled re-challenge was done and there was recurrence of proximal muscle weakness. There were no evidences of any other possible metabolic, infective, organic or other pathologic causes giving rise to that condition and Naranjo adverse drug reaction probability scale suggested that it was “probable” that glipizide was responsible for the development of myopathy in this patient. PMID:27440956

  16. 1. General view to southwest showing proximity of house to ...

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

    1. General view to southwest showing proximity of house to bridge and north elevation of house. - Locke Avenue Bridge, Bridge Tender's House, East side of Locke Avenue, 12 feet south of Locke Avenue Bridge, Swedesboro, Gloucester County, NJ

  17. View to northeast, showing west elevation and south side. Proximity ...

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

    View to northeast, showing west elevation and south side. Proximity of fence of adjacent subdivision precluded photography of north side. - Drew-Sherwood Farm, Barn, 7927 Elk Grove Boulevard, Elk Grove, Sacramento County, CA

  18. Abnormalities of proximal femoral growth after severe Perthes' disease.

    PubMed

    Sponseller, P D; Desai, S S; Millis, M B

    1989-08-01

    We studied the pattern of proximal femoral growth after severe Perthes' disease (Catterall grade III or IV) by retrospective analysis of serial radiographs in 52 hips (46 patients). Our aim was to determine the relationship between proximal femoral growth abnormalities and metaphyseal cysts, epiphyseal extrusion, physeal narrowing, and extensive epiphyseal necrosis. The average follow-up after treatment was 9.8 years (range 4 to 16 years), and 37 of the hips were followed to skeletal maturity. Slowing of proximal femoral growth was common: symmetrical abnormality was seen in 26 hips and asymmetrical abnormality in nine. However, definite premature closure of the proximal femoral physis was seen in only three hips. Abnormality seemed to be due to altered growth velocity rather than to bar formation in most cases. Metaphyseal cysts, epiphyseal extrusion and physeal narrowing during the active stage of the disease, alone or in combination, were found to be neither sensitive nor specific predictors of the subsequent growth pattern.

  19. Differential permeability of the proximal and distal rabbit small bowel

    PubMed Central

    Ross, Allan; Rubin, Allen W.; Deren, Julius J.

    1972-01-01

    The permeability of the proximal and distal rabbit intestine for two to six carbon polyhydric alcohols was compared. Intestinal segments were mounted in chambers that permitted the measurement of the unidirectional flux across the brush border membrane. For both proximal and distal intestine, the permeability for a series of polyhydric alcohols decreased with increasing size. The proximal intestine was more permeable for four, five, and six carbon polyhydric alcohols than distal intestine. This regional permeability difference can be attributed to variations in the permeability characteristics of the brush border specifically. The uptake of alcohols was nonsaturable and was not inhibited by phlorizine or n-ethylmaleimide. The results are compatible with the concept that the brush border membrane has properties similar to artificial porous membranes and that the equivalent radius of the pores of the proximal intestine exceeds that of the distal gut. PMID:4639025

  20. Analysis on the characteristics of pulsed laser proximity fuze's echo

    NASA Astrophysics Data System (ADS)

    Wang, Kun; Chen, Huimin

    2011-06-01

    With the rapid development of semiconductor technology and laser technology, a kind of proximity fuze named pulsed laser proximity fuze has been applied. Compared with other fuzes, pulsed laser proximity fuze has high ranging precision and strong resistance to artificial active interference. It is an important development tendency of proximity fuze. The paper analyze the characteristic of target echo of laser signal, and then make theoretical analysis and calculation on the laser signal transmission in the smog. Firstly, use the pulse width of 10ns semiconductor laser fuze to do typical targets experiment, to get the echo information of target distance is 5m; then to do smog interference experiment, by comparing the pulse width amplitude and backscattering signal amplitude of laser fuze in simulation and experiment, analyzing the effect of anti-clutter, providing the evidence for the subsequent of circuit of signal amplification and processing.

  1. Post-traumatic osteonecrosis of the proximal humerus.

    PubMed

    Patel, Shelain; Colaco, Henry B; Elvey, Michael E; Lee, Marcus H

    2015-10-01

    Post-traumatic osteonecrosis of the proximal humerus represents a challenging problem to the surgeon. It is commonly seen following multi-fragmentary fractures of the proximal humerus which may affect the long-term functional recovery after such injuries. This review summarises the current evidence on risk factors, reasons why estimating its epidemiology is difficult, the vascular supply of the humeral head, classification, and management options.

  2. [Merle D'Aubigne's oblique proximal femoral osteotomy. Surgical technique].

    PubMed

    López Sosa, Francisco H; Valentín-Guerrero, Santiago; Miranda-López, Eduardo

    2008-01-01

    Proximal femoral osteotomy with the technique described by Merle D'AubignC and Valliant was used in the treatment of adult patients with osteoarthritis or idiopathic avascular necrosis. Dr. Antonio Flores applied this technique to children with subluxation and acetabular dysplasia, identified with exaggerated anteversion and valgus of the proximal femur. He reported correction of the deformity in 75% of patients. The purpose of this paper is to describe the technique, its indications and complications.

  3. Hemiarthroplasty for proximal humeral fracture: restoration of the Gothic arch.

    PubMed

    Krishnan, Sumant G; Bennion, Phillip W; Reineck, John R; Burkhead, Wayne Z

    2008-10-01

    Proximal humerus fractures are the most common fractures of the shoulder girdle, and initial management of these injuries often determines final outcome. When arthroplasty is used to manage proximal humeral fractures, surgery remains technically demanding, and outcomes have been unpredictable. Recent advances in both technique and prosthetic implants have led to more successful and reproducible results. Key technical points include restoration of the Gothic arch, anatomic tuberosity reconstruction, and minimal soft tissue dissection.

  4. Design and Clinical Application of Proximal Humerus Memory Connector

    NASA Astrophysics Data System (ADS)

    Xu, Shuo-Gui; Zhang, Chun-Cai

    2011-02-01

    Treatment for comminuted proximal humerus fractures and nonunions are a substantial challenge for orthopedic surgeons. Plate and screw fixation does not provide enough stability to allow patients to begin functional exercises early after surgery. Using shape memory material nickel titanium alloy, we designed a new device for treating severe comminuted proximal humerus fractures that accommodates for the anatomical features of the proximal humerus. Twenty-two cases of comminuted fracture, malunion, and nonunion of the proximal humerus were treated with the proximal humeral memory connector (PHMC). No external fixation was needed after the operation and patients began active shoulder exercises an average of 8 days after the operation. Follow-up evaluation (mean 18.5 months) revealed that bone healing with lamellar bone formation occurred an average of 3.6 months after surgery for the fracture cases and 4.5 months after surgery for the nonunion cases. Average shoulder function was 88.5 according to the criteria of Michael Reese. PHMC is an effective new device to treat comminuted proximal humerus fractures and nonunions. The use of this device may reduce the need for shoulder joint arthroplasty.

  5. Psychological responses to the proximity of climate change

    NASA Astrophysics Data System (ADS)

    Brügger, Adrian; Dessai, Suraje; Devine-Wright, Patrick; Morton, Thomas A.; Pidgeon, Nicholas F.

    2015-12-01

    A frequent suggestion to increase individuals' willingness to take action on climate change and to support relevant policies is to highlight its proximal consequences, that is, those that are close in space and time. But previous studies that have tested this proximizing approach have not revealed the expected positive effects on individual action and support for addressing climate change. We present three lines of psychological reasoning that provide compelling arguments as to why highlighting proximal impacts of climate change might not be as effective a way to increase individual mitigation and adaptation efforts as is often assumed. Our contextualization of the proximizing approach within established psychological research suggests that, depending on the particular theoretical perspective one takes on this issue, and on specific individual characteristics suggested by these perspectives, proximizing can bring about the intended positive effects, can have no (visible) effect or can even backfire. Thus, the effects of proximizing are much more complex than is commonly assumed. Revealing this complexity contributes to a refined theoretical understanding of the role that psychological distance plays in the context of climate change and opens up further avenues for future research and for interventions.

  6. Coordinated regulation of cardiac Na(+)/Ca (2+) exchanger and Na (+)-K (+)-ATPase by phospholemman (FXYD1).

    PubMed

    Cheung, Joseph Y; Zhang, Xue-Qian; Song, Jianliang; Gao, Erhe; Chan, Tung O; Rabinowitz, Joseph E; Koch, Walter J; Feldman, Arthur M; Wang, JuFang

    2013-01-01

    Phospholemman (PLM) is the founding member of the FXYD family of regulators of ion transport. PLM is a 72-amino acid protein consisting of the signature PFXYD motif in the extracellular N terminus, a single transmembrane (TM) domain, and a C-terminal cytoplasmic tail containing three phosphorylation sites. In the heart, PLM co-localizes and co-immunoprecipitates with Na(+)-K(+)-ATPase, Na(+)/Ca(2+) exchanger, and L-type Ca(2+) channel. The TM domain of PLM interacts with TM9 of the α-subunit of Na(+)-K(+)-ATPase, while its cytoplasmic tail interacts with two small regions (spanning residues 248-252 and 300-304) of the proximal intracellular loop of Na(+)/Ca(2+) exchanger. Under stress, catecholamine stimulation phosphorylates PLM at serine(68), resulting in relief of inhibition of Na(+)-K(+)-ATPase by decreasing K(m) for Na(+) and increasing V(max), and simultaneous inhibition of Na(+)/Ca(2+) exchanger. Enhanced Na(+)-K(+)-ATPase activity lowers intracellular Na(+), thereby minimizing Ca(2+) overload and risks of arrhythmias. Inhibition of Na(+)/Ca(2+) exchanger reduces Ca(2+) efflux, thereby preserving contractility. Thus, the coordinated actions of PLM during stress serve to minimize arrhythmogenesis and maintain inotropy. In acute cardiac ischemia and chronic heart failure, either expression or phosphorylation of PLM or both are altered. PLM regulates important ion transporters in the heart and offers a tempting target for development of drugs to treat heart failure.

  7. Antenatal Betamethasone Attenuates the Angiotensin-(1-7)/Mas Receptor/Nitric Oxide Axis in Isolated Proximal Tubule Cells.

    PubMed

    Su, Yixin; Bi, Jianli; Pulgar, Victor M; Chappell, Mark C; Rose, James C

    2017-02-22

    We previously reported a sex-specific effect of antenatal treatment with betamethasone (Beta) on sodium (Na(+)) excretion in adult sheep whereby treated males but not females had an attenuated natriuretic response to Ang-(1-7). The present study determined the Na(+) uptake and nitric oxide (NO) response to low dose Ang-(1-7) (1 pM) in renal proximal tubule cells (RPTC) from adult male and female sheep antenatally exposed to Beta or vehicle. Data were expressed as % of basal uptake or area under the curve (AUC) for Na(+) or % of control for NO. Male Beta RPTC exhibited greater Na(+) uptake than male vehicle cells (433±28% vs. 330±26%; p<0.05); however, Beta exposure had no effect on Na(+) uptake in the female cells (255±16% vs. 255±14%; p>0.05). Ang-(1-7) significantly inhibited Na(+) uptake in RPTC from vehicle male (214±11%) and from both vehicle (190±14%) and Beta (209±11%) females, but failed to attenuate Na+ uptake in Beta male cells. Beta exposure also abolished stimulation of NO by Ang-(1-7) in male, but not female RPTC. Both the Na+ and NO responses to Ang-(1-7) were blocked by Mas receptor antagonist [D-Ala7]-Ang-(1-7). We conclude that the tubular Ang-(1-7)-Mas-NO pathway is attenuated in males and not females by antenatal Beta exposure. Moreover, since primary cultures of RPTC retain both the sex and Beta-induced phenotype of the adult kidney in vivo they appear to be an appropriate cell model to examine the effects of fetal programming on Na+ handling by the renal tubules.

  8. Induced spectral gap and pairing correlations from superconducting proximity effect

    NASA Astrophysics Data System (ADS)

    Chiu, Ching-Kai; Cole, William S.; Das Sarma, S.

    2016-09-01

    We theoretically consider superconducting proximity effect, using the Bogoliubov-de Gennes (BdG) theory, in heterostructure sandwich-type geometries involving a normal s -wave superconductor and a nonsuperconducting material with the proximity effect being driven by Cooper pairs tunneling from the superconducting slab to the nonsuperconducting slab. Applications of the superconducting proximity effect may rely on an induced spectral gap or induced pairing correlations without any spectral gap. We clarify that in a nonsuperconducting material the induced spectral gap and pairing correlations are independent physical quantities arising from the proximity effect. This is a crucial issue in proposals to create topological superconductivity through the proximity effect. Heterostructures of three-dimensional topological insulator (TI) slabs on conventional s -wave superconductor (SC) substrates provide a platform, with proximity-induced topological superconductivity expected to be observed on the "naked" top surface of a thin TI slab. We theoretically study the induced superconducting gap on this naked surface. In addition, we compare against the induced spectral gap in heterostructures of SC with a normal metal or a semiconductor with strong spin-orbit coupling and a Zeeman splitting potential (another promising platform for topological superconductivity). We find that for any model for the non-SC metal (including metallic TI) the induced spectral gap on the naked surface decays as L-3 as the thickness (L ) of the non-SC slab is increased in contrast to the slower 1 /L decay of the pairing correlations. Our distinction between proximity-induced spectral gap (with its faster spatial decay) and pairing correlation (with its slower spatial decay) has important implications for the currently active search for topological superconductivity and Majorana fermions in various superconducting heterostructures.

  9. Investigating the influences of season and coastal proximity on the elemental composition of harvested rainwater.

    PubMed

    Martin, A R; Coombes, P J; Dunstan, R H

    2010-01-01

    Chemical qualities of harvested rainwater were assessed at two residential study sites on the east coast of Australia in relation to coastal proximity and surrounding land uses over the course of a winter and summer month. Daily rainwater samples were collected from the base outlet and surface levels of stored water for chemical analyses. High resolution inductively coupled plasma-mass spectrometry (ICP-MS) was used to analyse 26 elements in all samples. The summer sampling regime for the industrial coastal Site 1 was dominated by wind gusts originating from the east with a total average elemental load of 25,900+/-17,000 microg/L compared to the significantly lower 10,600+/-3,370 microg/L measured during the winter month, where 84% of wind gust events originated from the west. Data for the inland Site 2, with no proximity to industry, revealed no significant changes in total average loads between the winter (4,870+/-578 microg/L) and summer (4,760+/-2,280 microg/L) months. The most abundant elements found at both sites included Na, K, Mg, and Zn. The rainwater storages at Site 2 fed from a relatively new concrete tiled roof catchment had significantly lower pH and conductivity measurements compared with those at Site 1 with an old galvanised iron roof catchment. It was concluded that seasonal differences in harvested water quality were likely influenced by prevailing wind direction and external influences such as surrounding land uses and proximity to the coast.

  10. InPhaDel: integrative shotgun and proximity-ligation sequencing to phase deletions with single nucleotide polymorphisms

    PubMed Central

    Patel, Anand; Edge, Peter; Selvaraj, Siddarth; Bansal, Vikas; Bafna, Vineet

    2016-01-01

    Phasing of single nucleotide (SNV), and structural variations into chromosome-wide haplotypes in humans has been challenging, and required either trio sequencing or restricting phasing to population-based haplotypes. Selvaraj et al. demonstrated single individual SNV phasing is possible with proximity ligated (HiC) sequencing. Here, we demonstrate HiC can phase structural variants into phased scaffolds of SNVs. Since HiC data is noisy, and SV calling is challenging, we applied a range of supervised classification techniques, including Support Vector Machines and Random Forest, to phase deletions. Our approach was demonstrated on deletion calls and phasings on the NA12878 human genome. We used three NA12878 chromosomes and simulated chromosomes to train model parameters. The remaining NA12878 chromosomes withheld from training were used to evaluate phasing accuracy. Random Forest had the highest accuracy and correctly phased 86% of the deletions with allele-specific read evidence. Allele-specific read evidence was found for 76% of the deletions. HiC provides significant read evidence for accurately phasing 33% of the deletions. Also, eight of eight top ranked deletions phased by only HiC were validated using long range polymerase chain reaction and Sanger. Thus, deletions from a single individual can be accurately phased using a combination of shotgun and proximity ligation sequencing. InPhaDel software is available at: http://l337x911.github.io/inphadel/. PMID:27105843

  11. Immunological Functions of the Membrane Proximal Region of MHC Class II Molecules

    PubMed Central

    Harton, Jonathan; Jin, Lei; Hahn, Amy; Drake, Jim

    2016-01-01

    Major histocompatibility complex (MHC) class II molecules present exogenously derived antigen peptides to CD4 T cells, driving activation of naïve T cells and supporting CD4-driven immune functions. However, MHC class II molecules are not inert protein pedestals that simply bind and present peptides. These molecules also serve as multi-functional signaling molecules delivering activation, differentiation, or death signals (or a combination of these) to B cells, macrophages, as well as MHC class II-expressing T cells and tumor cells. Although multiple proteins are known to associate with MHC class II, interaction with STING (stimulator of interferon genes) and CD79 is essential for signaling. In addition, alternative transmembrane domain pairing between class II α and β chains influences association with membrane lipid sub-domains, impacting both signaling and antigen presentation. In contrast to the membrane-distal region of the class II molecule responsible for peptide binding and T-cell receptor engagement, the membrane-proximal region (composed of the connecting peptide, transmembrane domain, and cytoplasmic tail) mediates these “non-traditional” class II functions. Here, we review the literature on the function of the membrane-proximal region of the MHC class II molecule and discuss the impact of this aspect of class II immunobiology on immune regulation and human disease. PMID:27006762

  12. Nb/InAs nanowire proximity junctions from Josephson to quantum dot regimes

    NASA Astrophysics Data System (ADS)

    Gharavi, Kaveh; Holloway, Gregory W.; LaPierre, Ray R.; Baugh, Jonathan

    2017-02-01

    The superconducting proximity effect is probed experimentally in Josephson junctions fabricated with InAs nanowires contacted by Nb leads. Contact transparencies t∼ 0.7 are observed. The electronic phase coherence length at low temperatures exceeds the channel length. However, the elastic scattering length is a few times shorter than the channel length. Electrical measurements reveal two regimes of quantum transport: (i) the Josephson regime, characterised by a dissipationless current up to ∼100 nA, and (ii) the quantum dot (QD) regime, characterised by the formation of Andreev bound states (ABS) associated with spontaneous QDs inside the nanowire channel. In regime (i), the behaviour of the critical current I c versus an axial magnetic field {B}| | shows an unexpected modulation and persistence to fields > 2 T. In the QD regime, the ABS are modelled as the current-biased solutions of an Anderson-type model. The applicability of devices in both transport regimes to Majorana fermion experiments is discussed.

  13. [Determination of proximal chemical composition of squid (dosidicus gigas) and development of gel products].

    PubMed

    Abugoch, L; Guarda, A; Pérez, L M; Paredes, M P

    1999-06-01

    The good nutritional properties of meat from big squid (Dosidicus gigas) living on the Chilean coast, was determined through its proximal composition 70 cal/100 g fresh meat; 82.23 +/- 0.98% moisture; 15.32 +/- 0.93% protein; 1.31 +/- 0.12% ashes; 0.87 +/- 0.18% fat and 0.27% NNE (non-nitrogen extract). The big squid meat was used to develop a gel product which contained NaCl and TPP. It was necessary to use additives for gel preparation, such as carragenin or alginate or egg albumin, due to the lack of gelation properties of squid meat. Formulations containing egg albumin showed the highest gel force measured by penetration as compared to those that contained carragenin or alginate.

  14. Effects of cumene hydroperoxide on cellular cation composition in frog kidney proximal tubular cells.

    PubMed

    Petrovic, S; Cemerikic, D

    2000-06-01

    Effects of cumene hydroperoxide were studied on the peritubular membrane potential and cellular cation composition in frog kidney proximal tubular cells. After perfusion of isolated frog kidneys for 30 min with 1.3x10(-4) mol l(-1) cumene hydroperoxide Ringer solution, the peritubular membrane potential gradually declined. The ouabain-like effects were demonstrated on cell Na and K activities after 1 h of perfusion with cumene hydroperoxide. The peritubular apparent transference number for potassium was decreased. Intracellular pH was not altered in the presence of cumene hydroperoxide. Intracellular free Ca(2+) concentration increased slowly and moderately. The concentration of the malondialdehyde in the kidney homogenates, measured as an index of lipid peroxidation, was increased. A previously observable effect of cumene hydroperoxide on the peritubular membrane potential was prevented by oxygen radical scavengers.

  15. RADIOGRAPHIC ASSESSMENT OF THE OPENING WEDGE PROXIMAL TIBIAL OSTEOTOMY

    PubMed Central

    Silva, Carlos Francisco Bittencourt; Camara, Eduardo Kastrup Bittencourt; Vieira, Luiz Antonio; Adolphsson, Fernando; Rodarte, Rodrigo Ribeiro Pinho

    2015-01-01

    Objective: To radiographically evaluate individuals who underwent opening wedge proximal tibial osteotomy, with the aim of analyzing the proximal tibial slope in the frontal and sagittal planes, and the patellar height. Method: The study included 22 individuals who were operated at the National Traumatology and Orthopedics Institute (INTO) for correction of varus angular tibial deviation using the opening wedge osteotomy (OWO) technique with the Orthofix monolateral external fixator. Patients with OWO whose treatment was completed between January 2000 and December 2006 were analyzed. The measurement technique consisted of using anteroposterior radiographs with loading and lateral views with the operated knees flexed at 30°. Results: There were no statistically significant differences between the pre and postoperative tibial slope and patellar height values in the patients evaluated. Conclusion: Opening wedge proximal tibial osteotomy is a technique that avoids the problems presented by high proximal tibial osteotomy, since it is done without causing changes to the extensor mechanism, ligament imbalance or distortions in the proximal tibia. PMID:27022577

  16. Developmental Changes in Proximal Tubule Tight Junction Proteins

    PubMed Central

    HADDAD, MAHA; LIN, FANGMING; DWARAKANATH, VANGIPURAM; CORDES, KIMBERLY; BAUM, MICHEL

    2014-01-01

    We demonstrated previously that neonatal proximal tubules have a lower passive paracellular permeability to chloride ions and higher resistance than that of adult proximal tubules. In addition, administration of thyroid hormone to neonates, before the normal maturational increase in serum thyroid hormone levels, prematurely accelerates the developmental increase in chloride permeability to adult levels. To test the hypothesis that there is a maturational change in tight junction proteins and that thyroid hormone mediates these changes, we examined the two known tight junction proteins present in proximal tubules, occludin and claudin 2. Using immunoblot and immunohistochemistry, we demonstrated that claudin 2 has a 4-fold greater abundance in neonatal proximal tubules than in adult tubules. Occludin, however, has a 4-fold greater expression in adult tubules than in neonatal tubules. Administration of thyroid hormone to neonates did not affect claudin 2 expression, occludin expression, or the transepithelial resistance in rat proximal tubule cells in vitro. In conclusion, there are postnatal maturational changes in tight junction proteins. The factors that cause these maturational changes are unknown but unlikely to be due solely to the maturational increase in thyroid hormone. PMID:15585672

  17. Intramedullary Nailing for Pathological Fractures of the Proximal Humerus

    PubMed Central

    Choi, Eun-Seok; Han, Ilkyu; Cho, Hwan Seong; Park, In Woong; Park, Jong Woong

    2016-01-01

    Background Endoprosthetic reconstruction is widely applied for pathological fractures of the proximal humerus; however, functional impairment is usually unsatisfactory. The aims of the current study are to evaluate the reliability of interlocking intramedullary (IM) nailing with cement augmentation as a fixation method in proximal humeral lesions and to assess functional outcomes. Methods We reviewed 32 patients with pathological fractures of the proximal humerus who underwent interlocking IM nailing and cement augmentation. Functional scores and pain relief were assessed as outcomes. Results The mean follow-up period was 14.2 months. The mean Musculoskeletal Tumor Society functional score and Karnofsky performance status scale score were 27.7 and 75.6, respectively. Improvement of pain assessed using the visual analogue scale was 6.2 on average. Thirty-one patients (97%) experienced no pain after surgery. The mean ranges of forward flexion and abduction were 115° and 112.6°, respectively. All patients achieved stability and had no local recurrence without failure of fixation until the last follow-up. Conclusions Proximal interlocking IM nailing with cement augmentation appears to be a reliable treatment option for pathological or impending fractures of the proximal humerus in selected patients with metastatic tumors, even with extensive bone destruction. PMID:27904730

  18. Fluoroscopically Guided Peritendinous Corticosteroid Injection for Proximal Hamstring Tendinopathy

    PubMed Central

    Nicholson, Luke T.; DiSegna, Steven; Newman, Joel S.; Miller, Suzanne L.

    2014-01-01

    Background: Proximal hamstring tendinopathy is an uncommon but debilitating cause of posterior thigh pain in athletes subjected to repetitive eccentric hamstring contraction, such as runners. Minimal data exist evaluating treatment options for proximal hamstring tendinopathy. Purpose: This retrospective study evaluates the effectiveness of fluoroscopically guided corticosteroid injections in treating proximal hamstring tendinopathy. Study Design: Case series; Level of evidence, 4. Methods: Eighteen athletes with 22 cases of magnetic resonance imaging–confirmed proximal hamstring tendinopathy were treated with corticosteroid injection and later contacted to evaluate the efficacy of the injection with the use of a questionnaire. Results: The visual analog score decreased from 7.22 preinjection to 3.94 postinjection (P < .001), level of athletic participation increased from 28.76% to 68.82% (P < .001) at a mean follow-up of 21 months, and 38.8% of patients experienced complete resolution at a mean follow-up of 24.8 months. The mean lower extremity function score at the time of follow-up was 60. Conclusion: A trial of fluoroscopically guided corticosteroid injection is warranted in patients presenting with symptoms of proximal hamstring tendinopathy refractory to conservative therapy. PMID:26535310

  19. A biomechanical comparison of proximal femoral nails and locking proximal anatomic femoral plates in femoral fracture fixation

    PubMed Central

    Ozkan, Korhan; Türkmen, İsmail; Sahin, Adem; Yildiz, Yavuz; Erturk, Selim; Soylemez, Mehmet Salih

    2015-01-01

    Background: The incidence of fractures in the trochanteric area has risen with the increasing numbers of elderly people with osteoporosis. Although dynamic hip screw fixation is the gold standard for the treatment of stable intertrochanteric femur fractures, treatment of unstable intertrochanteric femur fractures still remains controversial. Intramedullary devices such as Gamma nail or proximal femoral nail and proximal anatomic femur plates are in use for the treatment of intertrochanteric femur fractures. There are still many investigations to find the optimal implant to treat these fractures with minimum complications. For this reason, we aimed to perform a biomechanical comparison of the proximal femoral nail and the locking proximal anatomic femoral plate in the treatment of unstable intertrochanteric fractures. Materials and Methods: Twenty synthetic, third generation human femur models, obtained for this purpose, were divided into two groups of 10 bones each. Femurs were provided as a standard representation of AO/Orthopedic Trauma Associationtype 31-A2 unstable fractures. Two types of implantations were inserted: the proximal femoral intramedullary nail in the first group and the locking anatomic femoral plate in the second group. Axial load was applied to the fracture models through the femoral head using a material testing machine, and the biomechanical properties of the implant types were compared. Result: Nail and plate models were locked distally at the same level. Axial steady load with a 5 mm/m velocity was applied through the mechanical axis of femur bone models. Axial loading in the proximal femoral intramedullary nail group was 1.78-fold greater compared to the plate group. All bones that had the plate applied were fractured in the portion containing the distal locking screw. Conclusion: The proximal femoral intramedullary nail provides more stability and allows for earlier weight bearing than the locking plate when used for the treatment of

  20. Evidence for a role of claudin 2 as a proximal tubular stress responsive paracellular water channel

    SciTech Connect

    Wilmes, Anja Aschauer, Lydia; Limonciel, Alice; Pfaller, Walter; Jennings, Paul

    2014-09-01

    Claudins are the major proteins of the tight junctions and the composition of claudin subtypes is decisive for the selective permeability of the paracellular route and thus tissue specific function. Their regulation is complex and subject to interference by several factors, including oxidative stress. Here we show that exposure of cultured human proximal tubule cells (RPTEC/TERT1) to the immunosuppressive drug cyclosporine A (CsA) induces an increase in transepithelial electrical resistance (TEER), a decrease in dome formation (on solid growth supports) and a decrease in water transport (on microporous growth supports). In addition, CsA induced a dramatic decrease in the mRNA for the pore forming claudins -2 and -10, and the main subunits of the Na{sup +}/K{sup +} ATPase. Knock down of claudin 2 by shRNA had no discernable effect on TEER or dome formation but severely attenuated apical to basolateral water reabsorption when cultured on microporous filters. Generation of an osmotic gradient in the basolateral compartment rescued water transport in claudin 2 knock down cells. Inhibition of Na{sup +}/K{sup +} ATPase with ouabain prevented dome formation in both cell types. Taken together these results provide strong evidence that dome formation is primarily due to transcellular water transport following a solute osmotic gradient. However, in RPTEC/TERT1 cells cultured on filters under iso-osmotic conditions, water transport is primarily paracellular, most likely due to local increases in osmolarity in the intercellular space. In conclusion, this study provides strong evidence that claudin 2 is involved in paracellular water transport and that claudin 2 expression is sensitive to compound induced cellular stress. - Highlights: • Cyclosporine A increased TEER and decreased water transport in RPTEC/TERT1 cells. • Claudins 2 and 10 were decreased in response to cyclosporine A. • Knock down of claudin 2 inhibited water transport in proximal tubular cells. • We

  1. Relationship between sodium-dependent phosphate transporter (NaPi-IIc) function and cellular vacuole formation in opossum kidney cells.

    PubMed

    Shiozaki, Yuji; Segawa, Hiroko; Ohnishi, Saori; Ohi, Akiko; Ito, Mikiko; Kaneko, Ichiro; Kido, Shinsuke; Tatsumi, Sawako; Miyamoto, Ken-ichi

    2015-01-01

    NaPi-IIc/SLC34A3 is a sodium-dependent inorganic phosphate (Pi) transporter in the renal proximal tubules and its mutations cause hereditary hypophosphatemic rickets with hypercalciuria (HHRH). In the present study, we created a specific antibody for opossum SLC34A3, NaPi-IIc (oNaPi-IIc), and analyzed its localization and regulation in opossum kidney cells (a tissue culture model of proximal tubular cells). Immunoreactive oNaPi-IIc protein levels increased during the proliferative phase and decreased during differentiation. Moreover, stimulating cell growth upregulated oNaPi-IIc protein levels, whereas suppressing cell proliferation downregulated oNaPi-IIc protein levels. Immunocytochemistry revealed that endogenous and exogenous oNaPi-IIc proteins localized at the protrusion of the plasma membrane, which is a phosphatidylinositol 4,5-bisphosphate (PIP2) rich-membrane, and at the intracellular vacuolar membrane. Exogenous NaPi-IIc also induced cellular vacuoles and localized in the plasma membrane. The ability to form vacuoles is specific to electroneutral NaPi-IIc, and not electrogenic NaPi-IIa or NaPi-IIb. In addition, mutations of NaPi-IIc (S138F and R468W) in HHRH did not cause cellular PIP2-rich vacuoles. In conclusion, our data anticipate that NaPi-IIc may regulate PIP2 production at the plasma membrane and cellular vesicle formation.

  2. Common relationships among proximate composition components in fishes

    USGS Publications Warehouse

    Hartman, K.J.; Margraf, F.J.

    2008-01-01

    Relationships between the various body proximate components and dry matter content were examined for five species of fishes, representing anadromous, marine and freshwater species: chum salmon Oncorhynchus keta, Chinook salmon Oncorhynchus tshawytscha, brook trout Salvelinus fontinalis, bluefish Pomatomus saltatrix and striped bass Morone saxatilis. The dry matter content or per cent dry mass of these fishes can be used to reliably predict the per cent composition of the other components. Therefore, with validation it is possible to estimate fat, protein and ash content of fishes from per cent dry mass information, reducing the need for costly and time-consuming laboratory proximate analysis. This approach coupled with new methods of non-lethal estimation of per cent dry mass, such as from bioelectrical impedance analysis, can provide non-destructive measurements of proximate composition of fishes. ?? 2008 The Authors.

  3. The thermometer of social relations: mapping social proximity on temperature.

    PubMed

    Ijzerman, Hans; Semin, Gün R

    2009-10-01

    "Holding warm feelings toward someone" and "giving someone the cold shoulder" indicate different levels of social proximity. In this article, we show effects of temperature that go beyond these metaphors people live by. In three experiments, warmer conditions, compared with colder conditions, induced (a) greater social proximity, (b) use of more concrete language, and (c) a more relational focus. Different temperature conditions were created by either handing participants warm or cold beverages (Experiment 1) or placing them in comfortable warm or cold ambient conditions (Experiments 2 and 3). These studies corroborate recent findings in the field of grounded cognition revealing that concrete experiences ground abstract concepts with which they are coexperienced. Our studies show a systemic interdependence among language, perception, and social proximity: Environmentally induced conditions shape not only language use, but also the perception and construal of social relationships.

  4. Bringing proximate neighbours into the study of US residential segregation.

    PubMed

    Friedman, Samantha

    2011-01-01

    The race and ethnicity of neighbours are thought to be critical in shaping household mobility underlying residential segregation. However, studies on this topic have used data at the census-tract level of analysis rather than at the proximate-neighbour level. Using a non-publicly available version of the neighbour-cluster sample within the American Housing Survey, this study incorporates data on the race, ethnicity and socioeconomic characteristics of the proximate neighbours of White, Black and Latino households and examines their impact on household residential satisfaction, out- and in-mobility. Results indicate that proximate-neighbour race and ethnicity matter in influencing endpoints of the mobility process and do not necessarily parallel those at the census-tract level. Implications of these findings are discussed as they relate to the study of residential segregation.

  5. VCSEL-based microsensors for photonic proximity fuzing of munitions

    NASA Astrophysics Data System (ADS)

    Keeler, G. A.; Mar, A.; Geib, K. M.; Hsu, A. Y.; Serkland, D. K.; Peake, G. M.

    2008-08-01

    This paper describes technologies developed at Sandia National Laboratories to support a joint DoD/DoE initiative to create a compact, robust, and affordable photonic proximity sensor for munitions fuzing. The proximity fuze employs high-power vertical-cavity surface-emitting laser (VCSEL) arrays, resonant-cavity photodetectors (RCPDs), and refractive micro-optics that are integrated within a microsensor whose volume is approximately 0.01 cm3. Successful development and integration of these custom photonic components should enable a g-hard photonic proximity fuze that replaces costly assemblies of discrete lasers, photodetectors, and bulk optics. Additional applications of this technology include void sensing, ladar and short-range 3-D imaging.

  6. Modular endoprosthetic replacement for metastatic tumours of the proximal femur

    PubMed Central

    Chandrasekar, Coonoor R; Grimer, Robert J; Carter, Simon R; Tillman, Roger M; Abudu, Adesegun T

    2008-01-01

    Background and aims Endoprosthetic replacements of the proximal femur are commonly required to treat destructive metastases with either impending or actual pathological fractures at this site. Modular prostheses provide an off the shelf availability and can be adapted to most reconstructive situations for proximal femoral replacements. The aim of this study was to assess the clinical and functional outcomes following modular tumour prosthesis reconstruction of the proximal femur in 100 consecutive patients with metastatic tumours and to compare them with the published results of patients with modular and custom made endoprosthetic replacements. Methods 100 consecutive patients who underwent modular tumour prosthetic reconstruction of the proximal femur for metastases using the METS system from 2001 to 2007 were studied. The patient, tumour and treatment factors in relation to overall survival, local control, implant survival and complications were analysed. Functional scores were obtained from surviving patients. Results and conclusion There were 45 male and 55 female patients. The mean age was 60.2 years. The indications were metastases. Seventy five patients presented with pathological fracture or with failed fixation and 25 patients were at a high risk of developing a fracture. The mean follow up was 15.9 months [range 0–77]. Three patients died within 2 weeks following surgery. 69 patients have died and 31 are alive. Of the 69 patients who were dead 68 did not need revision surgery indicating that the implant provided single definitive treatment which outlived the patient. There were three dislocations (2/5 with THR and 1/95 with unipolar femoral heads). 6 patients had deep infections. The estimated five year implant survival (Kaplan-Meier analysis) was 83.1% with revision as end point. The mean TESS score was 64% (54%–82%). We conclude that METS modular tumour prosthesis for proximal femur provides versatility; low implant related complications and

  7. Proximal arm kinematics affect grip force-load force coordination.

    PubMed

    Vermillion, Billy C; Lum, Peter S; Lee, Sang Wook

    2015-10-01

    During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio (P = 0.042), intrinsic finger muscle activation (P = 0.045), and flexor-extensor ratio (P < 0.001). Biomechanical coupling between extrinsic hand muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio).

  8. Evolution and proximate expression of human paternal investment.

    PubMed

    Geary, D C

    2000-01-01

    In more than 95% of mammalian species, males provide little direct investment in the well-being of their offspring. Humans are one notable exception to this pattern and, to date, the factors that contributed to the evolution and the proximate expression of human paternal care are unexplained (T. H. Clutton-Brock, 1989). The nature, extent, and influence of human paternal investment on the physical and social well-being of children are reviewed in light of the social and ecological factors that are associated with paternal investment in other species. On the basis of this review, discussion of the evolution and proximate expression of human paternal investment is provided.

  9. Investigation of proximity effects in electron microscopy and lithography

    SciTech Connect

    Walz, M.-M.; Vollnhals, F.; Rietzler, F.; Schirmer, M.; Steinrueck, H.-P.; Marbach, H.

    2012-01-30

    A fundamental challenge in lithographic and microscopic techniques employing focused electron beams are so-called proximity effects due to unintended electron emission and scattering in the sample. Herein, we apply a method that allows for visualizing electron induced surface modifications on a SiN substrate covered with a thin native oxide layer by means of iron deposits. Conventional wisdom holds that by using thin membranes proximity effects can be effectively reduced. We demonstrate that, contrary to the expectation, these can be indeed larger on a 200 nm SiN-membrane than on the respective bulk substrate due to charging effects.

  10. Double-driven shield capacitive type proximity sensor

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1993-01-01

    A capacity type proximity sensor comprised of a capacitance type sensor, a capacitance type reference, and two independent and mutually opposing driven shields respectively adjacent to the sensor and reference and which are coupled in an electrical bridge circuit configuration and driven by a single frequency crystal controlled oscillator is presented. The bridge circuit additionally includes a pair of fixed electrical impedance elements which form adjacent arms of the bridge and which comprise either a pair of precision resistances or capacitors. Detection of bridge unbalance provides an indication of the mutual proximity between an object and the sensor. Drift compensation is also utilized to improve performance and thus increase sensor range and sensitivity.

  11. Longitudinal spin Seebeck effect free from the proximity Nernst effect.

    PubMed

    Kikkawa, T; Uchida, K; Shiomi, Y; Qiu, Z; Hou, D; Tian, D; Nakayama, H; Jin, X-F; Saitoh, E

    2013-02-08

    This Letter provides evidence for intrinsic longitudinal spin Seebeck effects (LSSEs) that are free from the anomalous Nernst effect (ANE) caused by an extrinsic proximity effect. We report the observation of LSSEs in Au/Y(3)Fe(5)O(12) (YIG) and Pt/Cu/YIG systems, showing that the LSSE appears even when the mechanism of the proximity ANE is clearly removed. In the conventional Pt/YIG structure, furthermore, we separate the LSSE from the ANE by comparing the voltages in different magnetization and temperature-gradient configurations; the ANE contamination was found to be negligibly small even in the Pt/YIG structure.

  12. Inverse Proximity Effect in Superconductor-ferromagnet Bilayer Structures

    SciTech Connect

    Xia, Jing

    2010-04-05

    Measurements of the polar Kerr effect using a zero-area-loop Sagnac magnetometer on Pb/Ni and Al/(Co-Pd) proximity-effect bilayers show unambiguous evidence for the 'inverse proximity effect,' in which the ferromagnet (F) induces a finite magnetization in the superconducting (S) layer. To avoid probing the magnetic effects in the ferromagnet, the superconducting layer was prepared much thicker than the light's optical penetration depth. The sign and size of the effect, as well as its temperature dependence agree with recent predictions by Bergeret et al.[1].

  13. Superconductor disorder and strong proximity coupling effects in Majorana nanowires

    NASA Astrophysics Data System (ADS)

    Cole, William; Sau, Jay

    Topological superconductivity induced by proximity to a conventional superconductor is only robust against moderate disorder in the parent superconductor, and only when the energy scale of the interface coupling is much smaller than the parent gap. I present detailed calculations of proximity-induced superconductivity in one-dimensional, spin-orbit coupled, semiconductor nanowires when the parent superconductor disorder and interface coupling exceed this limit. This parameter regime is characterized by unique spectroscopic signatures on both sides of the external field tuned topological phase transition. This work is supported by LPS-MPO-CMTC, Microsoft Q, and JQI-NSF-PFC.

  14. Proximity Operations Nano-Satellite Flight Demonstration (PONSFD) Rendezvous Proximity Operations Design and Trade Studies

    NASA Astrophysics Data System (ADS)

    Griesbach, J.; Westphal, J. J.; Roscoe, C.; Hawes, D. R.; Carrico, J. P.

    2013-09-01

    The Proximity Operations Nano-Satellite Flight Demonstration (PONSFD) program is to demonstrate rendezvous proximity operations (RPO), formation flying, and docking with a pair of 3U CubeSats. The program is sponsored by NASA Ames via the Office of the Chief Technologist (OCT) in support of its Small Spacecraft Technology Program (SSTP). The goal of the mission is to demonstrate complex RPO and docking operations with a pair of low-cost 3U CubeSat satellites using passive navigation sensors. The program encompasses the entire system evolution including system design, acquisition, satellite construction, launch, mission operations, and final disposal. The satellite is scheduled for launch in Fall 2015 with a 1-year mission lifetime. This paper provides a brief mission overview but will then focus on the current design and driving trade study results for the RPO mission specific processor and relevant ground software. The current design involves multiple on-board processors, each specifically tasked with providing mission critical capabilities. These capabilities range from attitude determination and control to image processing. The RPO system processor is responsible for absolute and relative navigation, maneuver planning, attitude commanding, and abort monitoring for mission safety. A low power processor running a Linux operating system has been selected for implementation. Navigation is one of the RPO processor's key tasks. This entails processing data obtained from the on-board GPS unit as well as the on-board imaging sensors. To do this, Kalman filters will be hosted on the processor to ingest and process measurements for maintenance of position and velocity estimates with associated uncertainties. While each satellite carries a GPS unit, it will be used sparsely to conserve power. As such, absolute navigation will mainly consist of propagating past known states, and relative navigation will be considered to be of greater importance. For relative observations

  15. The theoretical simulation on electrostatic distribution of 1st proximity region in proximity focusing low-light-level image intensifier

    NASA Astrophysics Data System (ADS)

    Zhang, Liandong; Bai, Xiaofeng; Song, De; Fu, Shencheng; Li, Ye; Duanmu, Qingduo

    2015-03-01

    Low-light-level night vision technology is magnifying low light level signal large enough to be seen by naked eye, which uses the photons - photoelectron as information carrier. Until the micro-channel plate was invented, it has been possibility for the realization of high performance and miniaturization of low-light-level night vision device. The device is double-proximity focusing low-light-level image intensifier which places a micro-channel plate close to photocathode and phosphor screen. The advantages of proximity focusing low-light-level night vision are small size, light weight, small power consumption, no distortion, fast response speed, wide dynamic range and so on. It is placed parallel to each other for Micro-channel plate (both sides of it with metal electrode), the photocathode and the phosphor screen are placed parallel to each other. The voltage is applied between photocathode and the input of micro-channel plate when image intensifier works. The emission electron excited by photo on the photocathode move towards to micro-channel plate under the electric field in 1st proximity focusing region, and then it is multiplied through the micro-channel. The movement locus of emission electrons can be calculated and simulated when the distributions of electrostatic field equipotential lines are determined in the 1st proximity focusing region. Furthermore the resolution of image tube can be determined. However the distributions of electrostatic fields and equipotential lines are complex due to a lot of micro-channel existing in the micro channel plate. This paper simulates electrostatic distribution of 1st proximity region in double-proximity focusing low-light-level image intensifier with the finite element simulation analysis software Ansoft maxwell 3D. The electrostatic field distributions of 1st proximity region are compared when the micro-channel plates' pore size, spacing and inclination angle ranged. We believe that the electron beam movement

  16. Performance characteristics of proximity focused ultraviolet image converters

    NASA Technical Reports Server (NTRS)

    Williams, J. T.; Feibelman, W. A.

    1973-01-01

    Performance characteristics of Bendix type BX 8025-4522 proximity focused image tubes for ultraviolet to visible light conversion are presented. Quantum efficiency, resolution, background, geometric distortion, and environmental test results are discussed. The converters use magnesium fluoride input windows with Cs - Te photocathodes, and P-11 phosphors on fiber optic output windows.

  17. Sharpening a Tool for Teaching: The Zone of Proximal Development

    ERIC Educational Resources Information Center

    Wass, Rob; Golding, Clinton

    2014-01-01

    Vygotsky's Zone of Proximal Development (ZPD) provides an important understanding of learning, but its implications for teachers are often unclear or limited and could be further explored. We use conceptual analysis to sharpen the ZPD as a teaching tool, illustrated with examples from teaching critical thinking in zoology. Our conclusions are…

  18. Scaffolding Critical Thinking in the Zone of Proximal Development

    ERIC Educational Resources Information Center

    Wass, Rob; Harland, Tony; Mercer, Alison

    2011-01-01

    This paper explores student experiences of learning to think critically. Twenty-six zoology undergraduates took part in the study for three years of their degree at the University of Otago, New Zealand. Vygotsky's developmental model of the Zone of Proximal Development (ZPD) provided a framework as we examined how critical thinking was developed.…

  19. Unconventional oil and gas: The role of politics and proximity

    NASA Astrophysics Data System (ADS)

    Schelly, Chelsea

    2016-10-01

    Political divisions are important in understanding public perceptions of unconventional oil and natural gas development, but so is proximity to drilling activities. New research highlights that, as geographical distance from development areas increases, political ideology becomes more influential in explaining diverging perceptions.

  20. Children's Attentional Processing of Mother and Proximity Seeking

    PubMed Central

    2015-01-01

    Attachment expectations regarding the availability of mother as a source for support are supposed to influence distressed children’s support seeking behavior. Because research is needed to better understand the mechanisms related to support seeking behavior, this study tested the hypothesis that the cognitive processing of mother-related information is linked to proximity and support seeking behavior. Uncertainty in maternal support has been shown to be characterized by a biased attentional encoding of mother, reducing the breadth of children’s attentional field around her. We investigated whether this attentional bias is related to how long distressed children wait before seeking their mother’s proximity. Thirty-three children (9-11 years) participated in this study that consisted of experimental tasks to measure attentional breadth and to observe proximity seeking behavior and of questionnaires to measure confidence in maternal support and experienced distress. Results suggested that distressed children with a more narrow attentional field around their mother wait longer to seek her proximity. Key Message: These findings provide a first support for the hypothesis that the attentional processing of mother is related to children’s attachment behavior. PMID:25927921

  1. Housing Projects and Crime: Testing a Proximity Hypothesis.

    ERIC Educational Resources Information Center

    Roncek, Dennis W.; And Others

    1981-01-01

    Proximity to public housing projects has a small but statistically significant effect on the incidence of violent crime. However, adjacency to public housing is a weak predictor of violent crime once the socioeconomic and housing characteristics of the adjacent blocks are taken into account. (Author/GC)

  2. Bridging Pedagogies: Drama, Multiliteracies, and the Zone of Proximal Development

    ERIC Educational Resources Information Center

    Macy, Leonora

    2016-01-01

    This article examines how one educator embraced Vygotsky's concept of the zone of proximal development (ZPD) while using drama to scaffold learning about Dr. Seuss's "The Lorax" for first-grade students. This learning event is interpreted with reference to the ZPD and the New London Group's pedagogy of multiliteracies. The author asserts…

  3. Vygotsky's Zone of Proximal Development: Implications for Gifted Education.

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.

    This paper reviews Lev Vygotsky's theories concerning optimizing of potential through assistance, support, or instruction. The paper notes that there is a "zone of proximal development" or a band around intelligence quotient (IQ) scores reflecting one's true potential. IQ tests are generally well-standardized and "static,"…

  4. A pedunculated intraluminal foregut reduplication cyst of the proximal esophagus.

    PubMed

    Craig, S R; Wallace, W H; Scott, D J; Cameron, E W

    1998-06-01

    A 66-year-old woman with a 3-month history of progressive dysphagia underwent transoral excision of a pedunculated cyst arising in the proximal esophagus. Histologic examination confirmed a pedunculated intraluminal foregut reduplication cyst. She remains well 1 year after excision with no recurrence of dysphagia.

  5. A Region of Proximal Learning Model of Study Time Allocation

    ERIC Educational Resources Information Center

    Metcalfe, J.; Kornell, N.

    2005-01-01

    A Region of Proximal Learning model is proposed emphasizing two components to people's study time allocation, controlled by different metacognitive indices. The first component is choice, which is further segmented into two stages: (1) a decision of whether to study or not and (2) the order of priority of items chosen. If the people's Judgments of…

  6. Proximal Positioning: A Strategy of Practice in Violin Pedagogy.

    ERIC Educational Resources Information Center

    Gholson, Sylvia A.

    1998-01-01

    Attempts to identify and characterize patterns of expert teaching practice as they occur in context, and to confirm these patterns through processes of verification. Observes teacher Dorothy DeLay in her studio, documenting her teaching through notes, audiotapes, and contextual artifacts. Discusses DeLay's theory of proximal positioning in…

  7. Proximal versus Distal Validity Coefficients for Teacher Observational Instruments

    ERIC Educational Resources Information Center

    Marzano, Robert J.

    2014-01-01

    This study examined the use of measures of student learning computed using end-of-year assessments (distal measures) versus measures of student learning associated with a single lesson (proximal measures) as criterion scores for the validity of observations of teachers' pedagogical skills. The validity coefficients computed using distal…

  8. Proximity to Coast Is Linked to Climate Change Belief

    PubMed Central

    Milfont, Taciano L.; Evans, Laurel; Sibley, Chris G.; Ries, Jan; Cunningham, Andrew

    2014-01-01

    Psychologists have examined the many psychological barriers to both climate change belief and concern. One barrier is the belief that climate change is too uncertain, and likely to happen in distant places and times, to people unlike oneself. Related to this perceived psychological distance of climate change, studies have shown that direct experience of the effects of climate change increases climate change concern. The present study examined the relationship between physical proximity to the coastline and climate change belief, as proximity may be related to experiencing or anticipating the effects of climate change such as sea-level rise. We show, in a national probability sample of 5,815 New Zealanders, that people living in closer proximity to the shoreline expressed greater belief that climate change is real and greater support for government regulation of carbon emissions. This proximity effect held when adjusting for height above sea level and regional poverty. The model also included individual differences in respondents' sex, age, education, political orientation, and wealth. The results indicate that physical place plays a role in the psychological acceptance of climate change, perhaps because the effects of climate change become more concrete and local. PMID:25047568

  9. Residential proximity to gasoline service stations and preterm birth.

    PubMed

    Huppé, Vicky; Kestens, Yan; Auger, Nathalie; Daniel, Mark; Smargiassi, Audrey

    2013-10-01

    Preterm birth (PTB) is a growing public health problem potentially associated with ambient air pollution. Gasoline service stations can emit atmospheric pollutants, including volatile organic compounds potentially implicated in PTB. The objective of this study was to evaluate the relationship between residential proximity to gasoline service stations and PTB. Singleton live births on the Island of Montreal from 1994 to 2006 were obtained (n=267,478). Gasoline service station locations, presence of heavy-traffic roads, and neighborhood socioeconomic status (SES) were determined using a geographic information system. Multivariable logistic regression was used to analyze the association between PTB and residential proximity to gasoline service stations (50, 100, 150, 200, 250, and 500 m), accounting for maternal covariates, neighborhood SES, and heavy-traffic roads. For all distance categories beyond 50 m, presence of service stations was associated with a greater odds of PTB. Associations were robust to adjustment for maternal covariates for distance categories of 150 and 200 m but were nullified when adjusting for neighborhood SES. In analyses accounting for the number of service stations, the likelihood of PTB within 250 m was statistically significant in unadjusted models. Associations were, however, nullified in models accounting for maternal covariates or neighborhood SES. Our results suggest that there is no clear association between residential proximity to gasoline service stations in Montreal and PTB. Given the correlation between proximity of gasoline service stations and SES, it is difficult to delineate the role of these factors in PTB.

  10. Osteosynthesis of the proximal femur anchorage of a cervical nail.

    PubMed

    el Banna, S; Burny, F; Bourgois, R; Donkerwolcke, M; Moulart, F

    1994-01-01

    One of the factors determining the stability of osteosynthesis is the mechanical strength of the bone fragments required for the anchorage of the implant. The aim is to study the driving of a Thornton nail in the proximal epiphysis of a human femur as a way to measure the strength of the trabecular bone and to predict the stability of the implanted system.

  11. Distal and variably proximal causes: education, obesity, and health.

    PubMed

    Schafer, Markus H; Ferraro, Kenneth F

    2011-11-01

    Medical sociologists hold that social conditions generate disparities across a host of health conditions through exposure to a variety of more proximate risk factors. Though distal and proximal causes jointly influence disease, the nature of risk accumulation may differ appreciably by the link of a proximal cause to the outcome in question. This paper employs a representative sample of over 3000 American older adults to examine whether position in the educational gradient amplifies the effect of obesity on two health outcomes. Results indicate that educational inequalities amplify the effect of high body mass index on disability (unstandardized coefficients across education groups range from -.05 [ns] to .26 [p < .01] among overweight respondents yet reach .17 [ns] to .73 [p < .001] among severely obese adults), but fail to amplify the consequences of severe obesity in the case of C-reactive protein (CRP) levels. Instead, educational gradients in CRP are most pronounced at lower levels of body mass. Sex-specific analyses further clarify these patterns, as the connections between CRP and body mass are particularly strong among women. We conclude that risk accumulation processes differ based on the proximity of causes to the health outcome under examination.

  12. Constructing a MEZOPED (Multiple Electronic Zone of Proximal Development).

    ERIC Educational Resources Information Center

    Murfin, Brian

    1994-01-01

    This paper presents the theoretical background for using computer-mediated communication to link children and scientists in a multiple electronic zone of proximal development. It is postulated that students will be able to perform at higher cognitive levels as a result of this increased interment contact with many adults. (LZ)

  13. Reflections on the Ecolab and the Zone of Proximal Development

    ERIC Educational Resources Information Center

    Luckin, Rosemary; du Boulay, Benedict

    2016-01-01

    In 1999 we reported a study that explored the way that Vygotsky's Zone of Proximal Development could be used to inform the design of an Interactive Learning Environment called the Ecolab. Two aspects of this work have subsequently been used for further research. Firstly, there is the interpretation of the ZPD and its associated theory that was…

  14. Proximal dup(10q): Case report and literature review

    SciTech Connect

    Barritt, J.A.; Teague, K.E.; Bodurtha, J.N.

    1994-09-01

    We report a case of a proximal dir dup(10q) in a female with multiple congenital anomalies. During infancy she was noted to gave growth retardation, microcephaly, microphthalmia, coloboma, a long, beaked nose, posteriorly rotated ears with simple helices, full bowed lips, widely-spaced nipples, broad first toes, hypermobile and proximally placed thumbs, a heart murmur, PDA, and coarctation of the aorta. Additional findings at age 13 included a full columella, short philtrum, thin limbs, bilateral blindness, and mental retardation, as well as continued growth retardation. Her medical history included precocious puberty at age 8 and a diagnosis of hyperactivity. Using FISH with multiple probes combined with GTG-banding, the aberrant chromosome was determined to be a dir dup(10)(q21{r_arrow}q22). Parental chromosomes were normal and the family history was unremarkable. The parental origin of the dir dup(10) is being assessed using DNA markers. Five similar cases of proximal dup(10q) have been reported previously. Consistent characteristics include low birth weight, developmental and psychomotor delay, growth retardation, and microcephaly. Also found in most cases were short prominent philtrum, bowed mouth, PDA, thin limbs, coloboma, micropthalmia, deep set eyes, and other ocular anomalies. Our case is unique in that she has a long, beaked nose, precocious puberty, and hyperactivity. Future studies such as this, using molecular cytogenetic techniques to better define the chromatin involved in proximal dup(10q), may lead to its recognition as a distinct clinical phenotype.

  15. Metastatic transitional cell carcinoma in proximal humerus of a dog

    PubMed Central

    Malek, Sarah; Murphy, Kimberly A.; Nykamp, Stephanie G.; Allavena, Rachel

    2011-01-01

    Transitional cell carcinoma (TCC) was diagnosed in the proximal humerus of a dog that was presented with persistent right forelimb lameness with no clinical signs of urinary tract involvement. A diagnosis of TCC was made from surgical biopsy of the humeral lesion with subsequent necropsy revealing the prostatic urethra as the primary site of the tumor. PMID:22379204

  16. Proximity to coast is linked to climate change belief.

    PubMed

    Milfont, Taciano L; Evans, Laurel; Sibley, Chris G; Ries, Jan; Cunningham, Andrew

    2014-01-01

    Psychologists have examined the many psychological barriers to both climate change belief and concern. One barrier is the belief that climate change is too uncertain, and likely to happen in distant places and times, to people unlike oneself. Related to this perceived psychological distance of climate change, studies have shown that direct experience of the effects of climate change increases climate change concern. The present study examined the relationship between physical proximity to the coastline and climate change belief, as proximity may be related to experiencing or anticipating the effects of climate change such as sea-level rise. We show, in a national probability sample of 5,815 New Zealanders, that people living in closer proximity to the shoreline expressed greater belief that climate change is real and greater support for government regulation of carbon emissions. This proximity effect held when adjusting for height above sea level and regional poverty. The model also included individual differences in respondents' sex, age, education, political orientation, and wealth. The results indicate that physical place plays a role in the psychological acceptance of climate change, perhaps because the effects of climate change become more concrete and local.

  17. Approximate proximal point methods for convex programming problems

    SciTech Connect

    Eggermont, P.

    1994-12-31

    We study proximal point methods for the finite dimensional convex programming problem minimize f(x) such that x {element_of} C, where f : dom f {contained_in} RIR is a proper convex function and C {contained_in} R is a closed convex set.

  18. Constructing Proximity: Relating to Readers in Popular and Professional Science

    ERIC Educational Resources Information Center

    Hyland, Ken

    2010-01-01

    The view of academic discourse as a rhetorical activity involving interactions between writers and readers is now central to most perspectives on EAP, but these interactions are conducted differently in different disciplinary and generic contexts. In this paper I use the term "proximity" to refer to a writer's control of those rhetorical features…

  19. West and south elevations, view to northeast. Proximity of house ...

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

    West and south elevations, view to northeast. Proximity of house and trees precluded photography of north and east elevations, but building is symmetrical. Entry is in east elevation; windmill was mounted at third story level on north elevation. - Drew-Sherwood Farm, Tank House, 7927 Elk Grove Boulevard, Elk Grove, Sacramento County, CA

  20. Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.

    PubMed

    Bleuze, M

    2012-06-01

    Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N=31), Plio-Pleistocene fossil hominins (N=8), Pan troglodytes troglodytes (N=13), and Pan paniscus (N=3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out.

  1. Rendezvous and Proximity Operations of the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Goodman, John L.

    2005-01-01

    Space Shuttle rendezvous missions present unique challenges that were not fully recognized when the Shuttle was designed. Rendezvous targets could be passive (i.e., no lights or transponders), and not designed to facilitate Shuttle rendezvous, proximity operations, and retrieval. Shuttle reaction control system jet plume impingement on target spacecraft presented induced dynamics, structural loading, and contamination concerns. These issues, along with limited reaction control system propellant in the Shuttle nose, drove a change from the legacy Gemini/Apollo coelliptic profile to a stable orbit profile, and the development of new proximity operations techniques. Multiple scientific and on-orbit servicing missions, and crew exchange, assembly and replenishment flights to Mir and to the International Space Station drove further profile and piloting technique changes. These changes included new proximity operations, relative navigation sensors, and new computer generated piloting cues. However, the Shuttle's baseline rendezvous navigation system has not required modification to place the Shuttle at the proximity operations initiation point for all rendezvous missions flown.

  2. Conservative Treatment for Bilateral Displaced Proximal Humerus Head Fracture

    PubMed Central

    Velutini-Becker, Ricardo; Aguilar-Alcalá, Luis D

    2016-01-01

    Proximal humerus fracture represents five to eight percent of all fractures and is twice as common in women than in men. Most cases of displaced fracture of the proximal humerus are treated surgically; it is probable that more cases are preferred to be treated surgically greater than required. The optimal treatment for these fractures remains controversial, but physicians have a tendency to treat via open reduction and fixation with angular locking plates or glenohumeral arthroplasty.  We present a case of a 71-year-old woman with bilateral displaced proximal humeral fracture. Conservative treatment was initiated with two hanging casts, achieving radiological reduction on week one. After two additional weeks of casting, treatment continued with radiologic control and home physical therapy, ultimately an excellent functional outcome and adequate radiological reduction was obtained.    Even in bilaterally displaced proximal humerus fractures, conservative treatment can be an efficient option, reducing complications, reaching adequate functional results and acceptable radiographic reduction.​ PMID:27489750

  3. On the Surprising Salience of Curvature in Grouping by Proximity

    ERIC Educational Resources Information Center

    Strother, Lars; Kubovy, Michael

    2006-01-01

    The authors conducted 3 experiments to explore the roles of curvature, density, and relative proximity in the perceptual organization of ambiguous dot patterns. To this end, they developed a new family of regular dot patterns that tend to be perceptually grouped into parallel contours, dot-sampled structured grids (DSGs). DSGs are similar to the…

  4. Interlanguage Pragmatics in the Zone of Proximal Development

    ERIC Educational Resources Information Center

    Ohta, Amy Snyder

    2005-01-01

    Vygotsky's zone of proximal development (ZPD) has been fruitfully applied in L2 research that examines second and foreign language learning. This paper considers the applicability of the ZPD to interlanguage pragmatics instruction and research. First, the ZPD is defined [Vygotsky, L.S., 1978. Mind in Society: The Development of Higher…

  5. Proximity effects and pair currents in cuprate junctions

    NASA Astrophysics Data System (ADS)

    Koren, Gad

    2017-04-01

    Proximity effects and pair currents were measured in epitaxial trilayer c-axis junctions comprised of a {{{PrBa}}}2{{{Cu}}}3{{{O}}}7-δ barrier sandwiched in between an overdoped {{{Y}}}0.94{{{Ca}}}0.06{{{Ba}}}2{{{Cu}}}3{{{O}}}7-δ layer and underdoped {{{YBa}}}2{{{Cu}}}2.7{{{Co}}}0.3{{{O}}}{y} layer. These junctions had two T c values of {{T}}{{c}}({high})=84{--}86 K and {{T}}{{c}}({low})=50{--}55 K, allowing investigation when both electrodes are superconducting, or when only one is superconducting while the other is in its pseudogap regime. For T below T c(high) but much above T c(low), two distinct proximity effect transitions were observed in the resistance at two temperature regimes, between 80 and 84 K, and 76 to 80 K. The first is a conventional proximity effect with the T c(high) electrode, while the second is a second order proximity effect of this electrode with uncorrelated pairs in the pseudogap regime. Conductance spectra measured between 2 and 86 K showed four different I c pair currents which were attributed to coherent pairs tunneling through the barrier below 42 K, to a fluctuating pairs current up to ∼77 K, and to a proximity pairs current between 77 and 84 K. All pair currents were suppressed under magnetic fields, with two distinct decay parameters that originated in the two different electrodes, with a significant suppression observed in the pseudogap regime.

  6. Proximal Scaphoid Arthroplasty Using the Medial Femoral Trochlea Flap

    PubMed Central

    Higgins, James P.; Burger, Heinze K.

    2013-01-01

    Background The medial trochlea of the femur (medial femoral trochlea, MFT) provides a source of convex osteocartilaginous vascularized bone that has been demonstrated to have a similar contour to the proximal scaphoid. This provides a potential solution for difficult recalcitrant proximal pole scaphoid nonunions. Materials and Methods Sixteen consecutive patients who underwent MFT proximal scaphoid arthroplasty were reviewed. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months. The results of this cohort were previously reported in detail but are summarized herein. Description of Technique The ability to reconstruct both bone and cartilage of the nonunion enables the surgeon to resect the nonunited proximal pole to prepare for scaphoid reconstruction. A segment of osteocartilaginous MFT is harvested in dimensions required by the scaphoid defect. The MFT segment is harvested on the transverse branch of the descending geniculate vessels. Fixation may be achieved with ease due to the size of the reconstructed segment. Results Computed tomography imaging demonstrated 15 of 16 reconstructed scaphoids achieving osseous union. Follow-up range of motion (ROM) of the wrist averaged 46.0° extension (range 28-80°) and 43.8° flexion (range 10-80°), which was similar to preoperative (average 45.7° extension and 43.0° flexion). Scapholunate angles remained unaffected (51.6° preoperatively and 48.6° postoperatively), indicating preservation of carpal relationships. Conclusions Vascularized MFT flaps provide a useful tool in the treatment of difficult proximal pole scaphoid nonunions. Early follow-up demonstrates high rate of achieving union with acceptable ROM and good pain relief. PMID:24436821

  7. A procedure to estimate proximate analysis of mixed organic wastes.

    PubMed

    Zaher, U; Buffiere, P; Steyer, J P; Chen, S

    2009-04-01

    In waste materials, proximate analysis measuring the total concentration of carbohydrate, protein, and lipid contents from solid wastes is challenging, as a result of the heterogeneous and solid nature of wastes. This paper presents a new procedure that was developed to estimate such complex chemical composition of the waste using conventional practical measurements, such as chemical oxygen demand (COD) and total organic carbon. The procedure is based on mass balance of macronutrient elements (carbon, hydrogen, nitrogen, oxygen, and phosphorus [CHNOP]) (i.e., elemental continuity), in addition to the balance of COD and charge intensity that are applied in mathematical modeling of biological processes. Knowing the composition of such a complex substrate is crucial to study solid waste anaerobic degradation. The procedure was formulated to generate the detailed input required for the International Water Association (London, United Kingdom) Anaerobic Digestion Model number 1 (IWA-ADM1). The complex particulate composition estimated by the procedure was validated with several types of food wastes and animal manures. To make proximate analysis feasible for validation, the wastes were classified into 19 types to allow accurate extraction and proximate analysis. The estimated carbohydrates, proteins, lipids, and inerts concentrations were highly correlated to the proximate analysis; correlation coefficients were 0.94, 0.88, 0.99, and 0.96, respectively. For most of the wastes, carbohydrate was the highest fraction and was estimated accurately by the procedure over an extended range with high linearity. For wastes that are rich in protein and fiber, the procedure was even more consistent compared with the proximate analysis. The new procedure can be used for waste characterization in solid waste treatment design and optimization.

  8. Studies of the electrical potential difference in rat proximal tubule.

    PubMed

    Seely, J F; Chirito, E

    1975-07-01

    The electrical potential difference (PD) in the rat proximal convoluted tubule was investigated in vivo as a function of distance from the glomerulus. The PD was found to be invariably negative (up to -4.5 mV) in the earliest segments (less than 0.5 mm from the glomerulus) and rose to positive values (+2 to +4) in the later segments (1 mm beyond the glomerulus). This change in PD correlated with the bubule fluid-to-plasma (TF/P) chloride ratios, which rose from unity in the early segments to approximately 1.3 in the late. Corresponding changes in PD and chloride ratios could be elicited by single-nephron stop-flow techniques in the early segments. Luminal perfusion techniques demonstrated a direct relationship between PD and tubule fluid chloride concentration. Acetazolamide was found to significantly reduce both late proximal PD (less than +2 mV) and TF/P chloride ratios (less than 1.06). Split-drop studies demonstrated that the negative PD in the early proximal tubule was dependent on the presence of glucose and alanine and the absence of a chloride gradient, whereas in the late proximal tubule under the same conditions the PD was not significantly different from zero. In this segment of the nephron the positive PD in free flow appeared to result from the chloride diffusion potential generated by preferential HCO3 reabsorption. These results provide further demonstration of intrinsic differences in the transport properties along the length of the proximal convoluted tubule.

  9. Proximal Fifth Metatarsal Fractures: Anatomy, Classification, Treatment and Complications

    PubMed Central

    Cheung, Chi Nok; Lui, Tun Hing

    2016-01-01

    Context Fractures of proximal fifth metatarsal are one of the most common fractures of the foot. Evidence Acquisition A search of PubMed for studies on proximal fifth metatarsal fracture and Jones fracture focusing on the classification and management was performed. The reference list of the retrieved articles was searched for additional related studies. Results The vascular supply and soft tissue anatomy of the fifth metatarsal explains the increased risk of delayed union and non-union in fractures at the metaphyseal-diaphyseal junction. Lawrence and Botte classify proximal fifth metatarsal fractures according to their location: tuberosity avulsion fractures (zone 1), fractures at metaphyseal-diaphyseal junction extending into the fourth-fifth intermetatarsal joint (zone 2) and proximal diaphyseal fractures (zone 3). Zone 1 fractures are treated conservatively with functional immobilization and early mobilization with excellent outcome. For zone 2 and zone 3 fractures, acute forms can be treated conservatively but with a risk of delayed union time and time for return to function. Therefore, early surgical fixation with intramedullary screw is advised in athletic individuals. For cases presented with signs of delayed union and non-union, surgical treatment with or without bone grafting is recommended. Complications of these fractures and their management are discussed in this report. Conclusions Lawrence and Botte’s classification of proximal fifth metatarsal fractures is recommended by experts, due to its implication on prognosis and treatment strategy. Zone 1 fractures should be treated conservatively due to their excellent healing potential. Early operative treatment is advised for zone 2 and zone 3 fractures, especially in the athletic group. Complications of delayed union, non-union and refractures should be treated by revision fixation and bone grafting. PMID:28144601

  10. The He II Proximity Effect and The Lifetime of Quasars

    NASA Astrophysics Data System (ADS)

    Khrykin, I. S.; Hennawi, J. F.; McQuinn, M.; Worseck, G.

    2016-06-01

    The lifetime of quasars is fundamental for understanding the growth of supermassive black holes, and is an important ingredient in models of the reionization of the intergalactic medium (IGM). However, despite various attempts to determine quasar lifetimes, current estimates from a variety of methods are uncertain by orders of magnitude. This work combines cosmological hydrodynamical simulations and 1D radiative transfer to investigate the structure and evolution of the He ii Lyα proximity zones around quasars at z ≃ 3-4. We show that the time evolution in the proximity zone can be described by a simple analytical model for the approach of the He ii fraction {x}{He{{II}}}(t) to ionization equilibrium, and use this picture to illustrate how the transmission profile depends on the quasar lifetime, quasar UV luminosity, and the ionization state of Helium in the ambient IGM (i.e., the average He ii fraction, or equivalently the metagalactic He ii ionizing background). A significant degeneracy exists between the lifetime and the average He ii fraction, however the latter can be determined from measurements of the He ii Lyα optical depth far from quasars, allowing the lifetime to be measured. We advocate stacking existing He ii quasar spectra at z ˜ 3, and show that the shape of this average proximity zone profile is sensitive to lifetimes as long as ˜30 Myr. At higher redshift z ˜ 4 where the He ii fraction is poorly constrained, degeneracies will make it challenging to determine these parameters independently. Our analytical model for He ii proximity zones should also provide a useful description of the properties of H i proximity zones around quasars at z ≃ 6-7.

  11. Na/K-ATPase Signaling and Salt Sensitivity: The Role of Oxidative Stress

    PubMed Central

    Liu, Jiang; Yan, Yanling; Nie, Ying; Shapiro, Joseph I.

    2017-01-01

    Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity. PMID:28257114

  12. The Utility of Proximal-Accretion Stratigraphy in Lateral Moraines

    NASA Astrophysics Data System (ADS)

    Samolczyk, M. A.; Osborn, G.

    2010-12-01

    Lateral-moraine stratigraphy is a valuable tool that can be used to constrain the timing and magnitude of alpine glacier fluctuations. Numerous lateral moraines, conventionally thought to have been constructed during the Little Ice Age (LIA), have been shown to be composite landforms that contain multiple till layers deposited by successively larger glacier advances. Organic matter and/or tephra sandwiched between the till layers constrain times of advance and retreat; wood fragments within till may provide the age of the till. Observation of contemporary lateral moraines has lead to the recognition of two means of lateral moraine construction: (1) accretion of tills onto the distal flank of the pre-existing lateral moraine, and (2) accretion or plastering of tills onto the proximal flank of the pre-existing moraine. In composite lateral moraines, distal and proximal accretion result in paleosurfaces that trend parallel to the current distal and proximal slope, respectively. Published work using lateral-moraine stratigraphy, for example at Bugaboo and Stutfield glaciers in the Canadian Rockies, has used evidence only from distal-accretion moraines. However, proximal-accretion moraines that provide chronological information have been found at Nisqually Glacier on Mount Rainier in Washington State, USA, and Columbia Glacier, an outlet of the Columbia Icefield in the Canadian Rockies. A gully cut into the left-lateral moraine at Nisqually Glacier exposes a sandy seam, with associated wood fragments, that runs parallel to the proximal moraine flank for ~20 m. Wood collected from different elevations along the seam have radiocarbon ages of 1715±15, 1700±15, and 1670±50 14C yr BP, indicating that the seam is similar in age along its extent and likely marks a paleosurface separating older till below and till of the First Millennium advance above. At Columbia Glacier, some till exposures in the prominent right-lateral moraine show a fissility dipping variably 40 to 50

  13. Proximate and landscape factors influence grassland bird distributions

    USGS Publications Warehouse

    Cunningham, M.A.; Johnson, D.H.

    2006-01-01

    Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and landscape scales on grassland birds, a group of birds of high conservation concern, in the Sheyenne National Grassland in North Dakota, USA. The Grassland contains a diverse array of grassland and woodland habitats. We surveyed breeding birds on 2015 100 m long transect segments during 2002 and 2003. We modeled the occurrence of 19 species in relation to habitat features (percentages of grassland, woodland, shrubland, and wetland) within each 100-m segment and to tree cover within 200-1600 m of the segment. We used information-theoretic statistical methods to compare models and variables. At the proximate scales, tree cover was the most important variable, having negative influences on 13 species and positive influences on two species. In a comparison of multiple scales, models with only proximate variables were adequate for some species, but models combining proximate with landscape information were best for 17 of 19 species. Landscape-only models were rarely competitive. Combined models at the largest scales (800-1600 m) were best for 12 of 19 species. Seven species had best models including 1600-m landscapes plus proximate factors in at least one year. These were Wilson's Phalarope (Phalaropus tricolor), Sedge Wren (Cistothorus platensis), Field Sparrow (Spizella pusilla), Grasshopper Sparrow (Ammodramus savannarum), Bobolink (Dolychonix oryzivorus), Red-winged Blackbird (Agelaius phoeniceus), and Brown-headed Cowbird (Molothrus ater). These seven are small-bodied species; thus larger-bodied species do not necessarily respond most to the largest landscapes. Our findings suggest that birds respond to habitat features at a variety of

  14. Proximate and landscape factors influence grassland bird distributions.

    PubMed

    Cunningham, Mary Ann; Johnson, Douglas H

    2006-06-01

    Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and landscape scales on grassland birds, a group of birds of high conservation concern, in the Sheyenne National Grassland in North Dakota, USA. The Grassland contains a diverse array of grassland and woodland habitats. We surveyed breeding birds on 2015 100 m long transect segments during 2002 and 2003. We modeled the occurrence of 19 species in relation to habitat features (percentages of grassland, woodland, shrubland, and wetland) within each 100-m segment and to tree cover within 200-1600 m of the segment. We used information-theoretic statistical methods to compare models and variables. At the proximate scales, tree cover was the most important variable, having negative influences on 13 species and positive influences on two species. In a comparison of multiple scales, models with only proximate variables were adequate for some species, but models combining proximate with landscape information were best for 17 of 19 species. Landscape-only models were rarely competitive. Combined models at the largest scales (800-1600 m) were best for 12 of 19 species. Seven species had best models including 1600-m landscapes plus proximate factors in at least one year. These were Wilson's Phalarope (Phalaropus tricolor), Sedge Wren (Cistothorus platensis), Field Sparrow (Spizella pusilla), Grasshopper Sparrow (Ammodramus savannarum), Bobolink (Dolychonix oryzivorus), Red-winged Blackbird (Agelaius phoeniceus), and Brown-headed Cowbird (Molothrus ater). These seven are small-bodied species; thus larger-bodied species do not necessarily respond most to the largest landscapes. Our findings suggest that birds respond to habitat features at a variety of

  15. Interlaminated ice-proximal glacimarine sediments in Muir Inlet, Alaska

    USGS Publications Warehouse

    Mackiewicz, N.E.; Powell, R.D.; Carlson, P.R.; Molnia, B.F.

    1984-01-01

    Muir Inlet in Glacier Bay, Alaska, is a glacial fjord receiving a tremendous volume of sediment annually. The rate of sediment accumulation is greatest proximal to Muir Glacier (about 9 m yr-1) and decreases away from the glacier. The primary sediment sources are meltwater streams discharging at subglacial and ice-marginal positions to form overflows, interflows, and underflows (continuous turbidity currents). Overflows and interflows interact with diurnal tidal currents and their volume and sediment concentration varies diurnally and annually with meltwater discharge. These effects produce cyclic deposits of a thin fine-grained sand or silt lamina that grades normally to a thicker poorly to very poorly sorted mud lamina. This lamina couplet is termed a cyclopel. Underflows are suggested to occur in this glacimarine environment because of conditions unique to subglacial fluvial systems. Underflow deposits occur only in proximal positions (177 ??m) is ubiquitous, though low (<5% by weight), and occurs as isolated particles, frozen pellets, or as lenses that in cores may have a lamina appearance. Proximally, ice-rafted debris is difficult to identify because proximal sediment is often as coarse-grained. Deposited sediment may be reworked by tidal currents, and sediment gravity flows. Depositional processes operating in Muir Inlet produce interlaminated sand/silt/clay that characterizes sediment proximal to a glacier and fines seaward to mud. Sediment is classified into one of three sediment types: 1. (1) Type I sediment is very fine grained (mean 8.65-7.17 ??), low in sand (0.1-11.2%), and very poorly to poorly sorted. It is the dominant sediment type in Muir Inlet, and is transported by plumes and deposited by suspension settling. 2. (2) Type II sediment is fine- to coarse-grained (mean 6.70-3.12 ??), low to high in sand (5.1-86.6%), and very poorly to moderately sorted. It represents reworked sediment, proximal plume deposits, or coarse-grained laminae of cyclopels

  16. Ginsenosides protect apical transporters of cultured proximal tubule cells from dysfunctions induced by h(2)o(2).

    PubMed

    Han, Ho Jae; Yoon, Byung Cheol; Park, Soo Hyun; Park, Ji Yeong; Oh, Young Joon; Lee, Yun Jung; Park, Kwon Moo

    2002-01-01

    Oxidative stress has been implicated as a primary cause of renal failure in certain renal diseases. Indeed, renal proximal tubule is a very sensitive site to oxidative stress and retains functionally fully characterized transporters. It has been reported that ginsenosides have a beneficial effect on diverse diseases including oxidative stress. However, the protective effect of ginsenosides on oxidative stress has not been elucidated in renal proximal tubule cells. Thus, we examined the effect of ginsenosides on oxidative stress-induced alteration of apical transporters and its related mechanism in renal proximal tubule cells. In the present study, hydrogen peroxide (H(2)O(2)) (>10(-5) M) inhibited alpha-methyl-D-glucopyranoside uptake in a dose-dependent manner (p < 0.05). It also inhibited Pi and Na(+) uptake. At a concentration of 20 microg/ml, total ginsenosides significantly reduced H(2)O(2)-induced inhibition of apical transporters. In contrast, protopanaxadiol (PD) and protopanaxatriol (PT) saponins exhibited a less preventive effect than total ginsenosides (p < 0.05). Furthermore, we examined its action mechanism. H(2)O(2) increased lipid peroxide formation, arachidonic acid (AA) release, and Ca(2+) uptake. These effects on H(2)O(2) were significantly prevented by total ginsenosides and PD or PT sanponins. However, total ginsenosides appear to be more protective than PD and PT saponins (p < 0.05). In conclusion, ginsenosides prevented H(2)O(2)-induced inhibition of apical transporters via a decrease in oxidative stress, AA release, and Ca(2+) uptake in primary cultured renal proximal tubule cells.

  17. In vivo study of transepithelial potential difference (TEPD) in proximal convoluted tubules of rat kidney by synchronization modulation electric field.

    PubMed

    Clausell, Mathis; Fang, Zhihui; Chen, Wei

    2014-07-01

    Synchronization modulation (SM) electric field has been shown to effectively activate function of Na(+)/K(+) pumps in various cells and tissues, including skeletal muscle cells, cardiomyocyte, monolayer of cultured cell line, and peripheral blood vessels. We are now reporting the in vivo studies in application of the SM electric field to kidney of living rats. The field-induced changes in the transepithelial potential difference (TEPD) or the lumen potential from the proximal convoluted tubules were monitored. The results showed that a short time (20 s) application of the SM electric field can significantly increase the magnitude of TEPD from 1-2 mV to about 20 mV. The TEPD is an active potential representing the transport current of the Na/K pumps in epithelial wall of renal tubules. This study showed that SM electric field can increase TEPD by activation of the pump molecules. Considering renal tubules, many active transporters are driven by the Na(+) concentration gradient built by the Na(+)/K(+) pumps, activation of the pump functions and increase in the magnitude of TEPD imply that the SM electric field may improve reabsorption functions of the renal tubules.

  18. Cryptosporidium, chronic diarrhoea and the proximal small intestinal mucosa.

    PubMed Central

    Phillips, A D; Thomas, A G; Walker-Smith, J A

    1992-01-01

    The association between Cryptosporidium, chronic diarrhoea and a proximal small intestinal mucosal enteropathy was reviewed over a six and a half year period. One hundred and twenty three children with cryptosporidiosis and no clinical evidence of immune deficiency were identified. 50% of children excreting only Cryptosporidium had chronic diarrhoea. Most cases (63%) of chronic diarrhoea occurred in the first two years of life. A mild to moderate enteropathy was present in all nine children undergoing a small intestinal biopsy and seven showed the presence of Cryptosporidium adhering to villous epithelium. All patients eventually recovered spontaneously. Cryptosporidium is a cause of chronic diarrhoea and a proximal small intestinal mucosal enteropathy in children without immune deficiency. Screening for the parasite should be part of the investigative procedures in children with chronic diarrhoea. Images Figure 4 PMID:1398230

  19. Ionic requirements of proximal tubular sodium transport. II. Hydrogen ion.

    PubMed

    Green, R; Giebisch, G

    1975-11-01

    Simultaneous perfusion to proximal convoluted tubules and peritubular capillaries was used to study the effects of different perfusion fluids on sodium reabsorption and hydrogen secretion, which was calculated as bicarbonate reabsorption and titratable acid. Results show that sodium reabsorption was not tightly coupled to hydrogen secretion. Bicarbonate stimulates both sodium reabsorption and hydrogen secretion, but Tris stimulates only sodium reabsorption. Imposing an adverse chloride gradient across the proximal tubule (C1- peritubular greater than C1- luminal) decreased sodium reabsorption but did not diminish hydrogen secretion. Diamox inhibited both net sodium and hydrogen transport. It is concluded that there is not firm linkage between sodium reabsorption and hydrogen secretion and that bicarbonate probably stimulates sodium transport by a number of mechanisms, including an effect on the sodium transport unrelated to its ability to increase hydrogen ion secretion.

  20. Upgrade of the proximity focusing RICH at Jlab

    SciTech Connect

    Cisbani, Evaristo; Colilli, Stefano; Cusanno, Francesco; Fratoni, Rolando; Frullani, Salvatore; Garibaldi, Franco; Giuliani, Fausto; Gricia, Massimo; Lucentini, Maurizio; Santavenere, Fabio; Urciuoli, Guido; Iodice, Mauro; Argentieri, A.; de Cataldo, Giacinto; De Leo, Raffaele; Lagamba, Luigi; Marrone, Stefano; Nappi, E.; Camsonne, Alexandre; Kross, Brian; Michaels, Robert; Reitz, Bodo; Segal, John; Wojtsekhowski, Bogdan; Zorn, Carl; Monno, E.; Breuer, Herbert

    2009-09-01

    The Hall A RICH at Jefferson Lab is undergoing an upgrade to adapt to the higher momentum kinematics of the neutron spin structure Transversity experiments planned to run in 2008. The JLab RICH is a proximity focusing detector using liquid C6F14 as Cherenkov radiator, a thin layer of CsI as photon converter, evaporated on segmented pad panels of a proportional chamber. The original RICH had a superior hadron identification up to 2 GeV/c with pion/kaon rejection at the level of 1:1000 at ~ similar90% intrinsic efficiency. The upgrade will extend this performance above 2.4 GeV/c by means of a larger photon detector (a multiwire-multipad proportional chamber) and a longer proximity gap which will improve the photon detection geometrical efficiency and the angular resolution, respectively.

  1. STRaND-2: Visual inspection, proximity operations & nanosatellite docking

    NASA Astrophysics Data System (ADS)

    Bridges, C. P.; Taylor, B.; Horri, N.; Underwood, C. I.; Kenyon, S.; Barrera-Ars, J.; Pryce, L.; Bird, R.

    The Surrey Training Research and Nanosatellite Demonstrator (STRaND) programme has been success in identifying and creating a leading low-cost nanosatellite programme with advanced attitude and orbit control system (AOCS) and experimental computing platforms based on smart-phone technologies. The next demonstration capabilities, that provide a challenging mission to the existing STRaND platform, is to perform visual inspection, proximity operations and nanosatellite docking. Visual inspection is to be performed using a COTS LIDAR system to estimate range and pose under 100 m. Proximity operations are controlled using a comprehensive guidance, navigation and control (GNC) loop in a polar form of the Hills Clohessy Wiltshire (HCW) frame including J2 perturbations. And finally, nanosatellite docking is performed at under 30 cm using a series of tuned magnetic coils. This paper will document the initial experiments and calculations used to qualify LIDAR components, size the mission thrust and tank requirements, and air cushion table demonstrations of the docking mechanism.

  2. Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors

    NASA Technical Reports Server (NTRS)

    Sadlier, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.

    2009-01-01

    We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 micrometers, 1450 times the mean-free path.

  3. Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors

    NASA Technical Reports Server (NTRS)

    Sadleir, John E.; Smith, Stephen J.; Bandler, SImon R.; Chervenak, James A.; Clem, John R.

    2009-01-01

    We have found experimentally that the critical current of a square superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. The observed behavior has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. We have observed the proximity effect in these devices over extraordinarily long lengths exceeding 100 microns.

  4. Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors

    NASA Technical Reports Server (NTRS)

    Sadleir, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.

    2010-01-01

    We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 micrometers, 1450 times the mean-free path.

  5. A critical assessment of proximal macrotexturing on cemented femoral components.

    PubMed

    Duffy, G P; Muratoglu, O K; Biggs, S A; Larson, S L; Lozynsky, A J; Harris, W H

    2001-12-01

    We analyzed the cement-metal interface of 3 different types of femoral components that had proximal macrotexturing after in vitro insertion and after fatigue testing designed to produce debonding and micromotion. These components were compared with clinical retrieval specimens. The cement did not flow into the macrotexturing; rather, hollow, brittle volcanoes or calderas were formed. These fragile protrusions of cement become worn down or abraded by debonded components. This abrasion of cement may contribute to the early and aggressive osteolysis seen in some of these early failures with proximal macrotextured components. The formation of these volcanos and calderas can be aborted by placing bone-cement onto the macrotexturing before stem insertion. This simple technique allows the macrotexturing to be filled with cement.

  6. Proximal symphalangism: Evidence of linkage to 17q

    SciTech Connect

    Francomano, C.A.; Rubenstein, J.R.; Polymeropoulos, M.H.

    1994-09-01

    Proximal symphalangism (PS; OMIM 185800) is an autosomal dominant disorder which is characterized by ankylosis of the proximal interphalangeal joints and an increased incidence of conductive deafness in some families. A large American kindred with PS was originally described by Cushing in 1916, segregating for this disorder in many generations. Several follow-up studies have confirmed the disorder in members of this kindred and have also suggested that conductive deafness is a pleiotropic effect of the mutant gene in this family. In an effort to localize the gene, we have studied 55 members of Cushing`s kindred with 85 microsatellite repeat polymorphisms spanning the human genome. Genetic linkage analysis with data for marker D17S809 gave significant evidence for linkage with Zmax=3.4 at recombination fraction {theta}=0.05.

  7. Rendezvous and Proximity Operations of the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Goodman, John L.

    2005-01-01

    Space Shuttle rendezous missions presented unique challenges that were not fully recognized when the Shuttle was designed. Rendezvous targets could be passive (i.e., no lights or transponders), and not designed to facilitate Shuttle rendezvous, proximity operations and retrieval. Shuttle reaction control system jet plume impingement on target spacecraft presented induced dynamics, structural loading and contamination concerns. These issues, along with limited forward reaction control system propellant, drove a change from the Gemimi/Apollo coelliptic profile heritage to a stable orbit profile, and the development of new proximity operations techniques. Multiple scientific and on-orbit servicing missions and crew exchange, assembly and replinishment flights to Mir and to the International Space Station drove further profile and piloting technique changes, including new relative navigation sensors and new computer generated piloting cues.

  8. Synostosis of proximal phalangeal bases for loss of distal metacarpal

    PubMed Central

    Jindal, Pankaj

    2016-01-01

    A finger rendered unstable due to loss of metacarpal head can be stabilized by creating a synostosis at the base of the proximal phalanx of the affected finger with the adjacent normal finger. A cortico cancellous graft bridges the two adjacent proximal phalanges at their bases which are temporarily stabilized with an external fixator. The procedure can be done for, recurrence of giant cell tumor of metacarpal and for traumatic metacarpal loss. The procedure and long term follow up of one patient is presented who had giant cell tumor. This option should be considered before offering ray amputation. There is no micro vascular surgery involved, nor is there any donor site morbidity. The graft heals well without any absorption. The affected finger shows excellent function in the long term followup. PMID:27904227

  9. Reverse shoulder arthroplasty for the management of proximal humerus fractures.

    PubMed

    Jobin, Charles M; Galdi, Balazs; Anakwenze, Oke A; Ahmad, Christopher S; Levine, William N

    2015-03-01

    The use of reverse shoulder arthroplasty is becoming increasingly popular for the treatment of complex three- and four-part proximal humerus fractures in the elderly compared with the often unpredictable and poor outcomes provided by open reduction and internal fixation and by hemiarthroplasty. Inferior results with plate osteosynthesis are often a result of complications of humeral head osteonecrosis, loss of fixation, and screw penetration through the humeral head, whereas major concerns with hemiarthroplasty are tuberosity resorption, malunion, and nonunion resulting in pseudoparalysis. Comparative studies support the use of reverse shoulder arthroplasty in elderly patients with complex proximal humerus fractures because the functional outcomes and relief of pain are reliably improved. Repair and union of the greater tuberosity fragment during reverse shoulder arthroplasty demonstrates improved external rotation, clinical outcomes, and patient satisfaction compared with outcomes after tuberosity resection, nonunion, or resorption. Satisfactory results can be obtained with careful preoperative planning and attention to technical details.

  10. Space station proximity operations windows: Human factors design guidelines

    NASA Technical Reports Server (NTRS)

    Haines, Richard F.

    1987-01-01

    Proximity operations refers to all activities outside the Space Station which take place within a 1-km radius. Since there will be a large number of different operations involving manned and unmanned vehicles, single- and multiperson crews, automated and manually controlled flight, a wide variety of cargo, and construction/repair activities, accurate and continuous human monitoring of these operations from a specially designed control station on Space Station will be required. Total situational awareness will be required. This paper presents numerous human factors design guidelines and related background information for control windows which will support proximity operations. Separate sections deal with natural and artificial illumination geometry; all basic rendezvous vector approaches; window field-of-view requirements; window size; shape and placement criteria; window optical characteristics as they relate to human perception; maintenance and protection issues; and a comprehensive review of windows installed on U.S. and U.S.S.R. manned vehicles.

  11. Adamantinoma of the proximal femur: a case report.

    PubMed

    Ii, Sadao; Tsuchiya, Hiroyuki; Takazawa, Koutaro; Minato, Hiroshi; Tomita, Katsuro

    2004-01-01

    Adamantinoma is a rare low-grade malignant bone tumor with an indolent course. The tibia is involved in 85%-90% of long-bone cases. We encountered a patient with primary adamantinoma of the proximal femur. A 60-year-old woman fell and fractured her proximal left femur in the area of a cystic lesion. She underwent an osteosynthesis procedure, and bone union was obtained. After 3 years she developed pain in the left thigh, and a radiographic abnormality was found at the fracture site. A metastatic bone tumor was suspected, and curettage and cementing were carried out. Histologically, we found an epithelial component but failed to detect any primary cancer. Local recurrence became evident after another 6 years. A marginal excision was performed and a bipolar femoral prosthesis was implanted. We finally diagnosed the patient with adamantinoma. In this report we describe the characteristics of this tumor and discuss the reasoning concerning the differential diagnosis and therapeutic plan.

  12. PROXIMAL FEMORAL EPIPHYSIOLYSIS AND SUBCLINICAL HYPOTHYROIDISM: CASE REPORT

    PubMed Central

    de Mello, Grasiele Correa; Grossi, Gabriela; Coelho, Sílvio Pereira

    2015-01-01

    Proximal femoral epiphysiolysis is an orthopedic disease that is prevalent during adolescence, because this coincides with the time of greatest growth of osteomuscular structures. Curiously, some patients present this disease early, and this outcome converts to the possible etiological explanation that the slippage might occur through a growth spurt. For these patients, the genesis of the slippage has not yet been elucidated, but endocrine disorders have been noted as possible causes. In an attempt to strengthen the theory of endocrinological etiology and present the results from surgical treatment for this pathological condition, the case of a male patient aged 9 years and 3 months with proximal femoral epiphysiolysis and subclinical hypothyroidism who was diagnosed and treated at our university's teaching hospital is reported here. PMID:27047883

  13. Scintillation Proximity Radioimmunoassay Utilizing 125I-Labeled Ligands

    NASA Astrophysics Data System (ADS)

    Udenfriend, Sidney; Diekmann Gerber, Louise; Brink, Larry; Spector, Sydney

    1985-12-01

    A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an 125I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the 125I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.

  14. Scintillation proximity radioimmunoassay utilizing 125I-labeled ligands

    SciTech Connect

    Udenfriend, S.; Gerber, L.D.; Brink, L.; Spector, S.

    1985-12-01

    A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an /sup 125/I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the /sup 125/I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.

  15. Long range p -wave proximity effect into a disordered metal

    NASA Astrophysics Data System (ADS)

    Keser, Aydin Cem; Stanev, Valentin; Galitski, Victor

    2015-03-01

    We use quasiclassical methods of superconductivity to study the superconducting proximity effect from a topological p -wave superconductor into a disordered quasi-one-dimensional metallic wire. We demonstrate that the corresponding Eilenberger equations with disorder reduce to a closed nonlinear equation for the superconducting component of the matrix Green's function. Remarkably, this equation is formally equivalent to a classical mechanical system (i.e., Newton's equations), with the Green function corresponding to a coordinate of a fictitious particle and the coordinate along the wire corresponding to time. This mapping allows us to obtain exact solutions in the disordered nanowire in terms of elliptic functions. A surprising result that comes out of this solution is that the p -wave superconductivity proximity induced into the disordered metal remains long range, decaying as slowly as the conventional s -wave superconductivity. It is also shown that impurity scattering leads to the appearance of a zero-energy peak.

  16. Longitudinal proximity effects in superconducting transition-edge sensors.

    PubMed

    Sadleir, John E; Smith, Stephen J; Bandler, Simon R; Chervenak, James A; Clem, John R

    2010-01-29

    We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T{c} of the TES is current dependent and at fixed current scales as 1/L{2}. We have also found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 microm, 1450 times the mean-free path.

  17. Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors

    SciTech Connect

    Sadleir, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.

    2010-01-29

    We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T{sub c} of the TES is current dependent and at fixed current scales as 1/L{sup 2}. We have also found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 {micro}m, 1450 times the mean-free path.

  18. [Pathological proximal femur fracture: consider also primary bone tumour].

    PubMed

    van de Sande, Michiel A J; van Rijswijk, Carla S P; Dijkstra, P D Sander; Taminiau, Antonie M H

    2010-01-01

    Two male and one female patient, aged 64, 70 and 51 respectively, were surgically treated for pathological fracture of the proximal femur without preoperative biopsy. In contrast to their benign radiological diagnosis, all three patients were finally diagnosed as having a malignant primary bone tumour. The proximal femur is the primary location of pathological fractures in the appendicular skeleton. Metastases to bone are the most common cause of a destructive lesion of the skeleton in an adult. Although rare, a primary bone tumour must be included in differential diagnosis of a pathological fracture. A systematic diagnostic strategy is critical to avoid complications that make curative treatment impossible. A solitary bone lesion seen on radiography should never be assumed to be a bone metastasis. Without further diagnostic research, surgical treatment for a pathological fracture should never be commenced before a definitive diagnosis is made.

  19. Disproportionate Proximity to Environmental Health Hazards: Methods, Models, and Measurement

    PubMed Central

    Maantay, Juliana A.; Brender, Jean D.

    2011-01-01

    We sought to provide a historical overview of methods, models, and data used in the environmental justice (EJ) research literature to measure proximity to environmental hazards and potential exposure to their adverse health effects. We explored how the assessment of disproportionate proximity and exposure has evolved from comparing the prevalence of minority or low-income residents in geographic entities hosting pollution sources and discrete buffer zones to more refined techniques that use continuous distances, pollutant fate-and-transport models, and estimates of health risk from toxic exposure. We also reviewed analytical techniques used to determine the characteristics of people residing in areas potentially exposed to environmental hazards and emerging geostatistical techniques that are more appropriate for EJ analysis than conventional statistical methods. We concluded by providing several recommendations regarding future research and data needs for EJ assessment that would lead to more reliable results and policy solutions. PMID:21836113

  20. Copper in silicon: Quantitative analysis of internal and proximity gettering

    SciTech Connect

    McHugo, S.A.; Flink, C.; Weber, E.R.

    1997-08-01

    The behavior of copper in the presence of a proximity gettering mechanism and a standard internal gettering mechanism in silicon was studied. He implantation-induced cavities in the near surface region were used as a proximity gettering mechanism and oxygen precipitates in the bulk of the material provided internal gettering sites. Moderate levels of copper contamination were introduced by ion implantation such that the copper was not supersaturated during the anneals, thus providing realistic copper contamination/gettering conditions. Copper concentrations at cavities and internal gettering sites were quantitatively measured after the annealings. In this manner, the gettering effectiveness of cavities was measured when in direct competition with internal gettering sites. The cavities were found to be the dominant gettering mechanism with only a small amount of copper gettered at the internal gettering sites. These results reveal the benefits of a segregation-type gettering mechanism for typical contamination conditions.

  1. Pediatric Scaphoid Proximal Pole Nonunion With Avascular Necrosis.

    PubMed

    Jernigan, Edward W; Smetana, Brandon S; Patterson, J Megan M

    2016-12-24

    A 13-year-old, right hand-dominant, otherwise healthy boy presented with left wrist pain 19 months after a nonmotorized scooter injury. Radiographs and magnetic resonance imaging at presentation demonstrated proximal pole scaphoid nonunion with avascular necrosis of the proximal fragment. Operative and nonsurgical treatment options were discussed and the family elected for an attempt at nonsurgical management. The patient was placed in a short-arm thumb spica cast, with a window for a bone stimulator, for 14 weeks. At the conclusion of the treatment, the pain had resolved and x-ray and computed tomography scan demonstrated bony union. The authors recommend considering an initial trial of nonsurgical management for treatment of all pediatric scaphoid nonunions.

  2. Proximity- and Astigmatism-Tolerant Testsites For Electrical Linewidth Measurement

    NASA Astrophysics Data System (ADS)

    Lin, Burn J.

    1989-07-01

    Electrical linewidth measurement is well-known for high precision and throughput. However, the standard four-point probe testsite is only useful for measuring the width of an isolated conducting line. Line-and-space and isolated spaces can be simulated satisfactorily by adding dummy lines parallel to the active line but weak links or potential electrical shorting situations often prematurely cause these structures to fail before their true limits are reached. In this paper, fully wrapped proximity- and astigmatism-tolerant designs for line-and-space and isolated spaces are shown. They have been successfully demonstrated with printed images. An application in evaluating the exposure-defocus window of a one-layer i-line resist using the proximity-tolerant testsites is given.

  3. [Proximal and distal rupture of the m. biceps brachii].

    PubMed

    Lorbach, O; Kieb, M; Grim, C; Engelhardt, M

    2010-12-01

    Ruptures of the biceps tendon account for a high percentage of tendon ruptures. The aetiology of proximal ruptures of the long head of the biceps tendon is often degenerative and they are frequently associated with lesions of the rotator cuff. The clinical findings are often not specific and long lasting. Distal ruptures of the biceps tendon mostly occur during eccentric contraction of the biceps muscle.Clinical tests, the associated haematoma and a distalisation or proximalisation of the muscle belly in combination with ultrasound or MRI to rule out combined diseases lead to the diagnosis. The possible options include conservative and operative treatment. Tenotomy and tenodesis lead to comparable results in the literature. Therefore, conservative treatment is mostly recommended in proximal ruptures. Operative treatment is preferred in distal ruptures of the biceps tendon in order to achieve an anatomical reconstruction of the muscle function. Chronic ruptures of the distal biceps tendon can be successfully treated with free autografts or allografts.

  4. Proximity nanovalve with large phase-tunable thermal conductance

    SciTech Connect

    Strambini, E. Giazotto, F.; Bergeret, F. S.

    2014-08-25

    We propose a phase-controlled heat-flux quantum valve based on the proximity effect driven by a superconducting quantum interference proximity transistor (SQUIPT). Its operation relies on the phase-dependent quasiparticle density of states in the Josephson weak-link of the SQUIPT which controls thermal transport across the device. In a realistic Al/Cu-based setup the structure can provide efficient control of thermal current inducing temperature swings exceeding ∼100 mK, and flux-to-temperature transfer coefficients up to ∼500 mK/Φ{sub 0} below 100 mK. The nanovalve performances improve by lowering the bath temperature, making the proposed structure a promising building-block for the implementation of coherent caloritronic devices operating below 1 K.

  5. Proximity potential for heavy ion reactions on deformed nuclei

    SciTech Connect

    Baltz, A. J.; Bayman, B. F.

    1982-01-01

    The usual treatment of the deformed optical model for analysis of heavy ion induced inelastic scattering data involves a deformed (target) radius, a spherical (projectile) radius and a potential strength dependent on the surface separation along the line between the two centers. Several authors using various approaches have shown that this center line potential is geometrically inadequate especially for description of higher L deformation parameters probed in heavy ion induced inelastic scattering experiments. A quantitatively adequate form of the deformed proximity potential suitable for use with a coupled channels reaction code in the analysis of inelastic scattering data above the Coulomb barrier is described. A major objective is to be able to extract reliably higher deformed multipole moments from such data. The deformed potential calculated in the folding model will serve as a geometrically exact benchmark to evaluate the accuracy of the proximity potential prescriptions. (WHK)

  6. Superconducting proximity effect for in situ and model layered systems

    SciTech Connect

    Finnemore, D.K.

    1980-01-01

    The primary drawback for in situ composites is that the ac losses are higher than for mechanically produced multifilamentary wire. To develop an understanding of the proximity effect so that analytical expressions will be available for design, a model system is developed based on PbCd. Items discussed include boundary conditions at SN interface, phonon spectral function, supercurrents through normal barriers, flux entry fields, and implications for in situ composites. (GHT)

  7. Surgical outcome of delayed presentation of congenital proximal radioulnar synostosis

    PubMed Central

    Garg, Gaurav; Gupta, Som P.

    2015-01-01

    Background: Presentation of proximal radioulnar synostosis varies from cosmetic concerns with no functional limitations to significant pronation deformity which hampers activities of daily living. Surgical management must be considered based on the position of the forearm and functional limitations. We describe the surgical technique, results, and complications of excision of the radial head along with the proximal radius up to the distal extent of the synostosis site and securing the osteotomized radial shaft with a tensor fascia lata graft. Materials and methods: Four patients having six affected elbows with delayed presentation of congenital proximal radioulnar synostosis with dislocated radial head managed surgically were included in the study. There were three males and one female with an average age of 20.25 years (ranging from 16 to 25 years). Preoperatively wrists were locked in the mean pronation position of 51.6° (ranging from 30° to 70°). The indications for surgery were limitation in activities of daily living and an obvious cosmetic deformity. Results: All patients were satisfied with the surgery and showed significant improvement in functional status. Mean active supination was 15° (ranging from 5 to 32°) with passive supination was a mean of 24.8° (ranging from 11° to 44°). Similarly, mean active pronation was 58.5° (ranging from 50° to 71°) with further passive correction up to a mean of 64.16° (ranging from 57° to 87°) at last follow up. Conclusions: This procedure is simple, cost effective, and a reasonable option for treatment of proximal radioulnar synostosis with a dislocated radial head in adult patients. The operation does not require any specialized team or implants, and can be performed in a moderately equipped hospital. PMID:27163088

  8. Stress fracture of the proximal fibula after total knee arthroplasty.

    PubMed

    Vaish, Abhishek; Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

    2016-04-22

    We report a rare case of proximal fibular fatigue fracture developing 14 years after total knee arthroplasty in a known case of rheumatoid arthritis. A valgus deformity of the knee can put abnormal stress on the upper fibula leading to its failure. We believe that, as the fibula acts as an important lateral strut, its disruption due to a fracture led to rapid progress of the valgus deformity of the knee in this patient.

  9. Lung cancer, proximity to industry, and poverty in northeast England.

    PubMed Central

    Pless-Mulloli, T; Phillimore, P; Moffatt, S; Bhopal, R; Foy, C; Dunn, C; Tate, J

    1998-01-01

    This study assesses whether deprived populations living close to industry experience greater mortality from lung cancer than populations with comparable socioeconomic characteristics living farther away. Mortality data, census data, a postal survey of living circumstances, historic and contemporary data on air quality and a historic land-use survey were used. Analysis was based on two conurbations in England, Teesside and Sunderland. Housing estates in Teesside were selected based on socioeconomic criteria and distinguished by proximity to steel and chemical industries; they were grouped into three zones: near (A), intermediate (B), and farther (C), with a single zone in Sunderland. We included 14,962 deaths in 27 estates. Standardized mortality ratios (SMR) for lung cancer [International Classification of Diseases #9 (ICD-9) 162] and cancers other than lung (ICD-9 140-239, excluding 162), and sex ratios were calculated. Mortality from lung cancer was well above national levels in all zones. For men, a weak gradient corresponding with proximity to industry at younger ages reversed at older ages. In women 0-64 years of age, stronger gradients in lung cancer mortality corresponded with proximity to industry across zones A, B, and C (SMR = 393, 251, 242, respectively). Overall rates in Teesside were higher than Sunderland rates for women aged 0-64 years (SMR = 287 vs. 185) and 65-74 years (SMR = 190 vs. 157). The association between raised lung cancer mortality and proximity to industry in women under 75 years of age could not be explained by smoking, occupation, socioeconomic factors, or artifact. Explanations for differences between men and women may include gender-specific occupational experiences and smoking patterns. Our judgment is that the observed gradient in women points to a role for industrial air pollution. Images Figure 1 Figure 2 PMID:9485483

  10. Effect of Shock Proximity on Richtmyer-Meshkov Growth

    SciTech Connect

    Glendinning, S G; Bolstad, J; Braun, D G; Edwards, M J; Hsing, W W; Lasinski, B F; Louis, H; Miles, A; Moreno, J; Peyser, T A; Remington, B A; Robey, H F; Turano, E J; Verdon, C P; Zhou, Y

    2002-10-31

    We report here experiments, conducted on the Omega laser [T.R. Boehly et al., Optics Commun. 133, 495 (1997)], and simulations that show reduced Richtmyer-Meshkov growth rates in a strongly shocked system with linear initial amplitudes (k{eta}{sub 0} {le} 0.9). The growth rate at early time is less than half the impulsive model prediction, rising at later time to near the impulsive prediction. An analytical model that accounts for shock proximity agrees with the results.

  11. A Proximate Biological Survey of San Diego Bay, California

    DTIC Science & Technology

    1975-01-01

    smoothhound) Carcharhinidac Galeorhinus zyoptems (soupfin sliark) Prionace glaum (blue sliark) Sphyrnidae Sphyrna zygaena ( hammerhead shark ...1 and 2, but an isolated group is also indicated in the south bay around station 10. The 28 Midshipman Bonito Sharks Croaker Bonito Figure 13...Species of fish most often collected at individual stat ions during Proximate Survey. 29 bonito and the sharks were taken, for the most part, at

  12. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis.

    PubMed

    Shah, Preeya T; Martin, Rebecca; Yan, Yanling; Shapiro, Joseph I; Liu, Jiang

    2016-01-01

    Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT).

  13. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis

    PubMed Central

    Shah, Preeya T.; Martin, Rebecca; Yan, Yanling; Shapiro, Joseph I.; Liu, Jiang

    2016-01-01

    Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT). PMID:27445847

  14. The effects of anions on fluid reabsorption from the proximal convoluted tubule of the rat.

    PubMed Central

    Green, R; Greenwood, S L; White, S

    1988-01-01

    1. Fluid reabsorption from surface proximal tubules of the rat was measured in vivo using stationary microperfusion techniques. Reabsorptive rate (Jv) was measured from droplets containing chloride as the main reabsorbable anion and when chloride was substituted by bromide, iodide, nitrate, acetate, isethionate or methylsulphate in either the tubular lumen alone or in both lumen and peritubular capillaries. 2. In tubules with an intact blood supply, droplet volume decreased in a manner best described by a single exponential and substitution of chloride by nitrate or bromide had no effect on Jv. Substitution by iodide or acetate inhibited Jv by approximately 17% but substitution by methylsulphate or isethionate caused droplets to transiently increase in volume before shrinkage which was itself inhibited by approximately 50%. The inhibitory action of isethionate was found to be concentration dependent. 3. Recollection and analysis of droplets which were initially free of chloride, containing either nitrate or isethionate, showed that chloride entered these droplets, but that the initial rate of chloride entry was greater for nitrate than isethionate droplets. 4. When tubules and capillaries were perfused with chloride solutions containing no bicarbonate, Jv was reduced to about 20% of the value when peritubular capillary blood flow was intact. Substituting chloride in the tubular and capillary perfusion revealed a sequence for supporting fluid reabsorption that was identical to that when chloride was substituted in tubule fluid alone: bromide = nitrate greater than iodide = acetate greater than isethionate. Addition of 2.0 mmol l-1 NaCN reduced the reabsorptive flux to zero. 5. The results of this study are consistent with transcellular transport of anions across the proximal tubular epithelium. The pathways for anion transport are likely to involve a series of non-selective mechanisms such as anion exchangers. PMID:3256612

  15. A fossil hominoid proximal femur from Kikorongo Crater, southwestern Uganda.

    PubMed

    DeSilva, Jeremy; Shoreman, Eleanor; MacLatchy, Laura

    2006-06-01

    The external morphology of a fragmentary right proximal femur from southwestern Uganda is described here. Discovered in the Kikorongo Crater of Queen Elizabeth National Park in 1961, this specimen was informally assigned to Homo sapiens (although never described) and tentatively dated to the late Pleistocene. However, because aspects of the external morphology of the femur align the fossil with the African great apes, we suggest that the Kikorongo femur may be the first postcranial fossil of the genus Pan. Like the African apes, the Kikorongo specimen lacks both an obturator externus groove and an intertrochanteric line. It has a short femoral neck with a circular cross section, and a narrow and deep superior notch. Using resampling statistics and discriminant function analysis, the Kikorongo femur clustered with the genus Pan, as opposed to Gorilla or Homo. However, if the specimen is from Pan, it would be large for this taxon. Furthermore, features that clearly distinguish the external morphology of Plio-Pleistocene hominin proximal femora from African ape femora, such as the shape of the femoral neck in cross section and femoral neck length, have converged in Holocene humans and African apes. Unfortunately, the internal morphology of the femoral neck of the Kikorongo fossil was not discernable. Although we hypothesize that the Kikorongo femur is from the genus Pan, there is such variability in the proximal femora of modern humans that, although it would be an unusual human, it remains possible that this fossil represents H. sapiens.

  16. The role of physical proximity in nosocomial diarrhea.

    PubMed

    Chang, V T; Nelson, K

    2000-09-01

    To examine physical proximity as a risk factor for the nosocomial acquisition of Clostridium difficile-associated diarrhea (CDAD) and of antibiotic-associated diarrhea (AAD), we assessed a retrospective cohort of 2859 patients admitted to a community hospital from 1 March 1987 through 31 August 1987. Of these patients, 68 had nosocomial CDAD and 54 had nosocomial AAD. In multivariate analysis, physical proximity to a patient with CDAD (relative risk [RR], 1.86; 95% confidence interval [CI], 1.06-3.28), exposure to clindamycin (RR, 4.22; 95% CI, 2.11-8.45), and the number of antibiotics taken (RR, 1.49; 95% CI, 1.23-1.81) were significant. For patients with nosocomial AAD, exposure to a roommate with AAD (RR, 3.94; 95% CI, 1. 27-12.24), a stay in an intensive care unit or cardiac care unit (RR, 1.93; 95% CI, 1.05-3.53), and the number of antibiotics taken (RR, 2.01; 95% CI, 1.67-2.40) were significant risk factors. Physical proximity may be an independent risk factor for acquisition of nosocomial CDAD and AAD.

  17. Risk factors and predictors of mortality for proximal humeral fractures

    PubMed Central

    Gooding, Benjamin WT; Manning, Paul A; Wallace, W Angus; Geoghegan, John M

    2014-01-01

    Background Risk factors for mortality after proximal humeral fracture, including socioeconomic status, are poorly defined. This retrospective review of prospectively collected data defines the epidemiology and predictors of mortality in association with proximal humeral fractures. Methods Patients who sustained proximal humeral fractures were identified from fragility fracture and trauma databases between May 2001 and September 2012. Results In total, 1880 patients with a mean age of 69 years and a male to female ratio of 2 : 3 were identified. Socioeconomic distribution is skewed towards the lowest and highest quintiles. Low-energy mechanisms caused 88% of fractures. Men sustain fractures when they are aged 10 years younger and via higher-energy mechanisms. In total, 536 patients (29%) died within the study period with a 1-year mortality of 9.8%, rising to 28.2% at 5 years. Female gender, increasing age, pathological fracture and increased number of co-morbidities were independent variables for increased mortality. Conclusions The present study, which was conducted over an 11-year period, is the first to combine the epidemiology and risk factors for mortality with socioeconomic rank. One-year mortality risk is twice that of the background matched population. Patient counselling with respect to increased mortality should be considered, especially in higher-risk elderly females with multiple co-morbidities. PMID:27582921

  18. Proximate and mineral content of restaurant steak meals.

    PubMed

    Green, E M; Appledorf, H

    1983-02-01

    Restaurant steak meals were analyzed for proximate and mineral composition by standard methodology. Nutritional adequacy of the meals was determined by comparing analyzed values with Recommended Dietary Allowances for adults. The meals were considered to be adequate in a nutrient if they provided at least one-third the RDA for that nutrient. Analyzed values were also compared with values obtained from food composition tables. The results of this study indicate that: 1. Restaurant steak meals differ significantly in weight of meal components, proximate components, and mineral components. 2. Although the meals were adequate in kilocalories and protein, they could be considered to be excessive since they provided more than 50% of the RDA for energy and more than 100% of the RDA for protein. 3. The meals can be considered inadequate in calcium for both men and women (only 16% of the RDA) and in iron for women (only 25% of the RDA). 4. Tables of food composition are useful in predicting the proximate and mineral composition of restaurant steak meals.

  19. Proximal femur segmentation in conventional pelvic x ray

    SciTech Connect

    Pilgram, Roland; Walch, Claudia; Kuhn, Volker; Schubert, Rainer; Staudinger, Roland

    2008-06-15

    A solid and accurate proximal femur segmentation technique using the popular active shape model (ASM) is proposed. For generating an optimal shape prior, the minimum description length, based on 200 supervised manual segmented proximal femur shapes, is used. The segmentation is based on a coarse to fine scaling technique including a profile scale space method. The segmentation results are compared using an optimal defined initial pose and a pose based on a registration technique. Using ideal template initialization, 95% of the shapes have been recovered exactly (average point-to-point error {approx}13 pixels, average point-to-boundary error {approx}7 pixels). Using a template-based initialization based on a registration technique, a successful segmentation rate of {approx}89% is achieved, with an average point-to-point error {approx}12 pixels, and an average point-to-boundary error {approx}8 pixels. With an adequate template initialization and an improved ASM, this method seems to provide an accurate tool for segmentation of the proximal femur shapes on conventional hip overview x-ray images.

  20. Reconstruction of the extensor mechanism after proximal tibia endoprosthetic replacement.

    PubMed

    Bickels, J; Wittig, J C; Kollender, Y; Neff, R S; Kellar-Graney, K; Meller, I; Malawer, M M

    2001-10-01

    The proximal tibia is a difficult area in which to perform a wide resection of a bone tumor. This difficulty is due to the intimate relationship of tumor in this location to the nerves and blood vessels of the leg, inadequate soft tissue coverage after endoprosthetic reconstruction, and the need to reconstruct the extensor mechanism. Competence of the extensor mechanism is the major determinant of functional outcome of these patients. Between 1980 and 1997, 55 patients underwent proximal tibia resection with endoprosthetic reconstruction for a variety of malignant and benign-aggressive tumors. Reconstruction of the extensor mechanism included reattachment of the patellar tendon to the prosthesis with a Dacron tape, reinforcement with autologous bone-graft, and attachment of an overlying gastrocnemius flap. All patients were followed for a minimum of 2 years; 6 patients (11%) had a transient peroneal nerve palsy, 4 patients (7.2%) had a fasciocutaneous flap necrosis, and 2 patients (3.6%) had a deep wound infection. Full extension to extension lag of 20 degrees was achieved in 44 patients, and 8 patients required secondary reinforcement of the patellar tendon. Function was estimated to be good to excellent in 48 patients (87%). Reattachment of the patellar tendon to the prosthesis and reinforcement with an autologous bone-graft and a gastrocnemius flap are reliable means to restore extension after proximal tibia endoprosthetic reconstruction.

  1. Using Protein-Confined Proximity To Determine Chemical Reactivity.

    PubMed

    Kobayashi, Tomonori; Hoppmann, Christian; Yang, Bing; Wang, Lei

    2016-11-16

    Chemical reactivity is essential for functional modification of biomolecules with small molecules and the development of covalent drugs. The reactivity between a chemical functional group of a small molecule and that of a large biomolecule cannot be reliably predicted from the reactivity of the corresponding functional groups separately installed on two small molecules, because the proximity effect on reactivity resulting from the binding of the small molecule to the biomolecule is challenging to achieve by mixing two small molecules. Here we present a new strategy to determine the chemical reactivity of two functional groups in the context of close proximity afforded by proteins. The functional groups to be tested were separately installed at the interface of two interacting proteins in the format of amino acid side chains via the expansion of the genetic code. Reaction of the two functional groups resulted in covalent cross-linking of interacting proteins, readily detectable by gel electrophoresis. Using this strategy, we evolved new synthetases to genetically encode N(ε)-fluoroacetyllysine (FAcK), an isosteric fluorine analogue of acetyllysine. We demonstrated that fluoroacetamide installed on FAcK, previously thought inert to biological functional groups, actually reacted with the thiol group of cysteine when in proximity. This strategy should be valuable for accurately evaluating chemical reactivity of small molecules toward large biomolecules, which will help avoid undesired side reactions of drugs and expand the repertoire of functional groups to covalently target biomolecules.

  2. Proximal Rectus Femoris Avulsion: Ultrasonic Diagnosis and Nonoperative Management

    PubMed Central

    Esser, Stephan; Jantz, David; Hurdle, Mark F.; Taylor, Walter

    2015-01-01

    Objective To present a case of ultrasonic diagnosis and nonoperative management of a complete proximal rectus femoris avulsion in a National Collegiate Athletic Association Division 1 soccer goalkeeper. Background While delivering a goal kick, a previously uninjured 24-year-old collegiate soccer goalkeeper had the sudden onset of right anterior thigh pain. He underwent rehabilitation with rapid resolution of his presenting pain but frequent intermittent recurrence of anterior thigh pain. After he was provided a definitive diagnosis with musculoskeletal ultrasound, he underwent an extended period of rehabilitation and eventually experienced complete recovery without recurrence. Differential Diagnosis Rectus femoris avulsion, rectus femoris strain or partial tear, inguinal hernia, or acetabular labral tear. Treatment Operative and nonoperative options were discussed. In view of the player's recovery, nonoperative options were pursued with a good result. Uniqueness Complete proximal rectus femoris avulsions are rare. Our case contributes to the debate on whether elite-level kicking and running athletes can return to full on-field performance without surgery. Conclusions Complete proximal rectus femoris avulsions can be treated effectively using nonoperative measures with good preservation of function even in the elite-level athlete. In addition, musculoskeletal ultrasound is an excellent tool for on-site evaluation and may help guide prognosis and management. PMID:25978099

  3. Effects of Hip Geometry on Fracture Patterns of Proximal Femur

    PubMed Central

    Kazemi, Seyyed Morteza; Qoreishy, Mohamad; Keipourfard, Ali; Sajjadi, Mohammadreza Minator; Shokraneh, Shahram

    2016-01-01

    Background: Some studies have previously shown that geometry of proximal femur can affect the probability of fracture and type of fracture. It happens since the geometry of the proximal femur determines how a force is applied to its different parts. In this study, we have compared proximal femur’s geometric characteristics in femoral neck (FNF), intertrochanteric (ITF) and Subtrochanteric (STF) fractures. Methods: In this study, 60 patients who had hip fractures were studied as case studies. They were divided into FNF, ITF and STF groups based on their fracture types (20 patients in each group). Patients were studied with x-ray radiography and CT scans. Radiological parameters including femoral neck length from lateral cortex to center of femoral head (FNL), diameter of femoral head (FHD), diameter of femoral neck (FND), femoral head neck offset (FHNO), neck-shaft angle (alpha), femoral neck anteversion (beta) were measured and compared in all three groups. Results: Amount of FNL was significantly higher in STF group compared to FNF (0.011) while ITF and STF as well as FNT and ITF did not show a significant different. Also, FND in FNF group was significantly lower than the other two groups, i.e. ITF and STF. In other cases there were no instances of significant statistical difference. Conclusion: Hip geometry can be used to identify individuals who are at the risk of fracture with special pattern. Also, it is important to have more studies in different populations and more in men. PMID:27517071

  4. Calcium transport in the rabbit superficial proximal convoluted tubule

    SciTech Connect

    Ng, R.C.; Rouse, D.; Suki, W.N.

    1984-09-01

    Calcium transport was studied in isolated S2 segments of rabbit superficial proximal convoluted tubules. 45Ca was added to the perfusate for measurement of lumen-to-bath flux (JlbCa), to the bath for bath-to-lumen flux (JblCa), and to both perfusate and bath for net flux (JnetCa). In these studies, the perfusate consisted of an equilibrium solution that was designed to minimize water flux or electrochemical potential differences (PD). Under these conditions, JlbCa (9.1 +/- 1.0 peq/mm X min) was not different from JblCa (7.3 +/- 1.3 peq/mm X min), and JnetCa was not different from zero, which suggests that calcium transport in the superficial proximal convoluted tubule is due primarily to passive transport. The efflux coefficient was 9.5 +/- 1.2 X 10(-5) cm/s, which was not significantly different from the influx coefficient, 7.0 +/- 1.3 X 10(-5) cm/s. When the PD was made positive or negative with use of different perfusates, net calcium absorption or secretion was demonstrated, respectively, which supports a major role for passive transport. These results indicate that in the superficial proximal convoluted tubule of the rabbit, passive driving forces are the major determinants of calcium transport.

  5. Hand proximity facilitates spatial discrimination of auditory tones

    PubMed Central

    Tseng, Philip; Yu, Jiaxin; Tzeng, Ovid J. L.; Hung, Daisy L.; Juan, Chi-Hung

    2014-01-01

    The effect of hand proximity on vision and visual attention has been well documented. In this study we tested whether such effect(s) would also be present in the auditory modality. With hands placed either near or away from the audio sources, participants performed an auditory-spatial discrimination (Experiment 1: left or right side), pitch discrimination (Experiment 2: high, med, or low tone), and spatial-plus-pitch (Experiment 3: left or right; high, med, or low) discrimination task. In Experiment 1, when hands were away from the audio source, participants consistently responded faster with their right hand regardless of stimulus location. This right hand advantage, however, disappeared in the hands-near condition because of a significant improvement in left hand's reaction time (RT). No effect of hand proximity was found in Experiments 2 or 3, where a choice RT task requiring pitch discrimination was used. Together, these results that the perceptual and attentional effect of hand proximity is not limited to one specific modality, but applicable to the entire “space” near the hands, including stimuli of different modality (at least visual and auditory) within that space. While these findings provide evidence from auditory attention that supports the multimodal account originally raised by Reed et al. (2006), we also discuss the possibility of a dual mechanism hypothesis to reconcile findings from the multimodal and magno/parvocellular account. PMID:24966839

  6. Progenitor Cells in Proximal Airway Epithelial Development and Regeneration

    PubMed Central

    Lynch, Thomas J.; Engelhardt, John F.

    2015-01-01

    Multiple distinct epithelial domains are found throughout the airway that are distinguishable by location, structure, function, and cell-type composition. Several progenitor cell populations in the proximal airway have been identified to reside in confined microenvironmental niches including the submucosal glands (SMGs), which are embedded in the tracheal connective tissue between the surface epithelium and cartilage, and basal cells that reside within the surface airway epithelium (SAE). Current research suggests that regulatory pathways that coordinate development of the proximal airway and establishment of progenitor cell niches may overlap with pathways that control progenitor cell responses during airway regeneration following injury. SMGs have been shown to harbor epithelial progenitor cells, and this niche is dysregulated in diseases such as cystic fibrosis. However, mechanisms that regulate progenitor cell proliferation and maintenance within this glandular niche are not completely understood. Here we discuss glandular progenitor cells during development and regeneration of the proximal airway and compare properties of glandular progenitors to those of basal cell progenitors in the SAE. Further investigation into glandular progenitor cell control will provide a direction for interrogating therapeutic interventions to correct aberrant conditions affecting the SMGs in diseases such as cystic fibrosis, chronic bronchitis, and asthma. PMID:24818588

  7. Cyclic adenosine monophosphate acutely inhibits and chronically stimulates Na/H antiporter in OKP cells.

    PubMed Central

    Cano, A; Preisig, P; Alpern, R J

    1993-01-01

    Parathyroid hormone, dopamine, alpha-adrenergic catecholamines, and angiotensin II regulate renal Na excretion, at least in part through modulation of acute cyclic (c)AMP-induced proximal tubule Na/H antiporter inhibition. The present studies examined the effect of chronic increases in cell cAMP on Na/H antiporter activity in OKP cells. Whereas 8-bromo cAMP acutely inhibited Na/H antiporter activity, chronic application for 6 h led to a 24% increase in Na/H antiporter activity measured 16-20 h after cAMP removal. This chronic persistent activation of the Na/H antiporter required > 2 h exposure. This effect was not a nonspecific effect of 8-bromo cAMP, in that addition of forskolin or forskolin + 3-isobutyl-1-methylxanthine for 6 h also led to a chronic persistent increase in Na/H antiporter activity. Inhibition of protein synthesis with cycloheximide prevented 8-bromo cAMP-induced Na/H antiporter stimulation. Although 8-bromo cAMP addition decreased cell pH by 0.15-0.20 pH U, Na/H antiporter stimulation could be dissociated from cell acidification. In summary, while cAMP acutely inhibits Na/H antiporter activity, it chronically increases antiporter activity. This chronic activation occurs with exogenous addition or endogenous generation of cAMP. These results imply that for hormones that modulate renal Na excretion and proximal tubule Na/H antiporter activity via cAMP and protein kinase A, acute effects may not predict chronic effects. PMID:7691881

  8. Clinical results of using the proximal humeral internal locking system plate for internal fixation of displaced proximal humeral fractures.

    PubMed

    Norouzi, Masoud; Naderi, Mohammad Nasir; Komasi, Mehdi Hemmati; Sharifzadeh, Seyyed Reza; Shahrezaei, Mostafa; Eajazi, Alireza

    2012-05-01

    Proximal humerus fractures are accounting for 4-5% of all fractures with increasing incidence. Proximal Humeral Internal Locking System (PHILOS) plate is a new plate which permits early mobility and lowers the risk of complications. The aim of this study was to evaluate the functional outcome and the complication rate after using this plate. Between 2006-2008, 37 patients with displaced 2-, 3-, and 4-part fractures of the proximal humerus underwent surgery using PHILOS plate. The mean range of follow-up was 12 months. Twenty patients were aged 60 years and younger, and 17 were aged older than 60 years. The average American Shoulder and Elbow Surgeons (ASES) score at the final follow-up was 77.62. According to Michener and colleagues classification, 5.4% of patients had an excellent outcome, 72.9% were minimally functionally limited, 16.2% were moderately functionally limited, and 5.4% were maximally functionally limited. The average ASES score between patients 60 years and older and those 60 years and younger was not different significantly. One patient developed avascular necrosis of the humeral head, 2 patients developed an infection, and no patients developed a nonunion. Fixation with PHILOS plate can be considered a good method with high union rates for this kind of fracture, especially in the older population with osteoporotic bone.

  9. 14 CFR 121.360 - Ground proximity warning-glide slope deviation alerting system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ground proximity warning-glide slope... Equipment Requirements § 121.360 Ground proximity warning-glide slope deviation alerting system. (a) No... turbine-powered airplane unless it is equipped with a ground proximity warning/glide slope...

  10. 14 CFR 121.360 - Ground proximity warning-glide slope deviation alerting system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ground proximity warning-glide slope... Equipment Requirements § 121.360 Ground proximity warning-glide slope deviation alerting system. (a) No... turbine-powered airplane unless it is equipped with a ground proximity warning/glide slope...

  11. Proximity association in polygynous western black crested gibbons (Nomascus concolor jingdongensis): network structure and seasonality.

    PubMed

    Guan, Zhen-Hua; Huang, Bei; Ning, Wen-He; Ni, Qing-Yong; Jiang, Xue-Long

    2013-01-01

    We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.

  12. Xenon adsorption in NaA zeolite cavities

    NASA Astrophysics Data System (ADS)

    McCormick, A. V.; Chmelka, B. F.

    Adsorption of xenon atoms in the α-cages of NaA zeolite has been studied using 129Xe NMR spectroscopy to probe directly the distribution and configuration of molecules in confined, microporous environments. The 129Xe NMR spectrum is sensitive to subtle changes in xenon environment, so relative populations of α-cages containing different numbers of xenon guests can be determined and the effects of other co-adsorbed species monitored. On the basis of 129Xe NMR spectra, the distribution of xenon atoms among NaA α-cages is shown to exhibit a marked dependence on the pressure at which the xenon guests are introduced. 129Xe NMR spectra recorded at 200 K reveal that xenon atoms in the NaA α-cages experience diminished mobility (resembling condensation phenomena) at higher temperatures than in the bulk gas of equivalent density. Thus, the chemical potential of adsorbed xenon can be investigated experimentally as a function of both temperature and guest density. The density dependence of the 129Xe chemical shift in Xe/NaA and in bulk xenon gas shows that Xe-Xe interactions in the proximity of the NaA cage wall are important in α-cages containing more than five xenon guests. This trend is linked to entropic effects which may enhance xenon adsorption in the confined environment of the NaA α-cages.

  13. Proximity Effects and Nonequilibrium Superconductivity in Transition-Edge Sensors

    NASA Technical Reports Server (NTRS)

    Sadleir, John E.; Smith, Stephen J.; Robinson, Ian K.; Finkbeiner, Fred M.; Chervenak, James A.; Bandler, Simon R.; Eckart, Megan E.; Kilbourne, Caroline A.

    2011-01-01

    We have recently shown that normal-metal/superconductor (N/S) bilayer TESs (superconducting Transition-Edge Sensors) exhibit weak-link behavior.l Here we extend our understanding to include TESs with added noise-mitigating normal-metal structures (N structures). We find TESs with added Au structures also exhibit weak-link behavior as evidenced by exponential temperature dependence of the critical current and Josephson-like oscillations of the critical current with applied magnetic field. We explain our results in terms of an effect converse to the longitudinal proximity effect (LoPE) 1, the lateral inverse proximity effect (LaiPE), for which the order parameter in the N/S bilayer is reduced due to the neighboring N structures. Resistance and critical current measurements are presented as a function of temperature and magnetic field taken on square Mol Au bilayer TESs with lengths ranging from 8 to 130 {\\mu}m with and without added N structures. We observe the inverse proximity effect on the bilayer over in-plane distances many tens of microns and find the transition shifts to lower temperatures scale approximately as the inverse square of the in- plane N-structure separation distance, without appreciable broadening of the transition width. We also present evidence for nonequilbrium superconductivity and estimate a quasiparticle lifetime of 1.8 \\times 10-10 s for the bilayer. The LoPE model is also used to explain the increased conductivity at temperatures above the bilayer's steep resistive transition.

  14. [Proximate analysis of straw by near infrared spectroscopy (NIRS)].

    PubMed

    Huang, Cai-jin; Han, Lu-jia; Liu, Xian; Yang, Zeng-ling

    2009-04-01

    Proximate analysis is one of the routine analysis procedures in utilization of straw for biomass energy use. The present paper studied the applicability of rapid proximate analysis of straw by near infrared spectroscopy (NIRS) technology, in which the authors constructed the first NIRS models to predict volatile matter and fixed carbon contents of straw. NIRS models were developed using Foss 6500 spectrometer with spectra in the range of 1,108-2,492 nm to predict the contents of moisture, ash, volatile matter and fixed carbon in the directly cut straw samples; to predict ash, volatile matter and fixed carbon in the dried milled straw samples. For the models based on directly cut straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.92% and 0.76% for moisture, 0.94% and 0.84% for ash, 0.88% and 0.82% for volatile matter, and 0.75% and 0.65% for fixed carbon, respectively. For the models based on dried milled straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.98% and 0.54% for ash, 0.95% and 0.57% for volatile matter, and 0.78% and 0.61% for fixed carbon, respectively. It was concluded that NIRS models can predict accurately as an alternative analysis method, therefore rapid and simultaneous analysis of multicomponents can be achieved by NIRS technology, decreasing the cost of proximate analysis for straw.

  15. Functional results after proximal row carpectomy to salvage a wrist.

    PubMed

    Kremer, Thomas; Sauerbier, Michael; Trankle, Markus; Dragu, Adrian; Germann, Guenter; Baumeister, Steffen

    2008-01-01

    Proximal row carpectomy is a movement-preserving procedure in the treatment of arthrosis of the wrist. We have retrospectively assessed the objective and subjective functional results after proximal row carpectomy. Assessment of outcome included measurement of range of movement (ROM), grip strength and self-assessment of pain relief with a visual analogue scale (VAS) and the Disabilities of arm, shoulder, and hand (DASH) questionnaire. Results were graded using the Mayo and Krimmer wrist scores. Fourty-five patients (mean age 48 (30-67) years) were evaluated with a follow-up of 32 (8-115) months. Underlying conditions included: degenerative arthritis secondary to scapholunate advanced collapse deformity, or chronic scaphoid non-union (n=35), Kienbock disease stage III (n=4), chronic perilunate dislocation and fracture-dislocation (n=4), avascular necrosis of the scaphoid (n=1), and severe radiocarpal arthrosis secondary to distal radial fracture (n=1). Active ROM for wrist extension and flexion was 70 degrees and mean radial and ulnar deviation 30.8 degrees . Grip strength was 51% of the unaffected side. The average DASH score was 26. The intensity of the pain, measured by VAS, was reduced by 44% after strenuous activities and by 71% at rest. The Mayo and Krimmer wrist scores were 55 and 62 points indicating good results; 32 patients returned to work and 25 patients to their former occupation. Our results show that proximal row carpectomy is a technically easy operation that preserves a satisfying ROM and pain relief, and is recommended when the head of the capitate and the lunate fossa are not affected by arthrosis.

  16. Proximate composition and caloric content of eight Lake Michigan fishes

    USGS Publications Warehouse

    Rottiers, Donald V.; Tucker, Robert M.

    1982-01-01

    We measured the proximate composition (percentage lipid, water, fat-free dry material, ash) and caloric content of eight species of Lake Michigan fish: lake trout (Salvelinus namaycush), coho salmon (Oncorhynchus kisutch), lake whitefish (Coregonus clupeaformis), bloater (Coregonus hoyi), alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), deepwater sculpin (Myoxocephalus quadricornis), and slimy sculpin (Cottus cognatus). Except for alewives, proximate composition and caloric content did not differ significantly between males and females. And, for coho salmon, there was no significant difference in composition between fish collected in different years. Lipid and caloric content of lake trout increased directly with age. In all species examined, lipids and caloric contents were significantly lower in small, presumably immature, fish than in larger, older fish. Lipid content of lake trout, lake whitefish, and bloaters (range of means, 16-22%) was nearly 3 times higher than that of coho salmon, sculpins, rainbow smelt, and alewives (range of means, 5.2-7.0%). The mean caloric content ranged from 6.9 to 7.1 kcal/g for species high in lipids and from 5.8 to 6.3 kcal/g for species low in lipids. Although the caloric content of all species varied directly with lipid content and inversely with water content, an increase in lipid content did not always coincide with a proportional increase in caloric content when other components of fish composition were essentially unchanged. This observation suggests that the energy content of fish estimated from the proximate composition by using universal conversion factors may not necessarily be accurate.

  17. Dynamic knee loads during gait predict proximal tibial bone distribution.

    PubMed

    Hurwitz, D E; Sumner, D R; Andriacchi, T P; Sugar, D A

    1998-05-01

    This study tested the validity of the prediction of dynamic knee loads based on gait measurements. The relationship between the predicted loads at the knee and the distribution of bone between the medial and lateral sides of the tibia was examined. The motion and external forces and moments at the knee were measured during gait and a statically determinate muscle model was used to predict the corresponding forces on the medial and lateral tibial plateaus. In particular, the relationship between the knee adduction moment during gait and the ratio or distribution of medial to lateral tibial bone mineral content was studied. Bone mineral content was measured with dual energy X-ray absorptiometry in four regions, two proximal regions 20 mm in height, one medial and one lateral and two distal regions 20 mm in height, one medial and one lateral. The best single predictor of the medial lateral ratio of proximal bone mineral content (bone distribution) was the adduction moment (R2=0.31, p=0.003). Adding weight (negative coefficient. p=0.0004) and the ratio of the average predicted peak force on the medial plateau to the predicted peak force on the lateral plateau (positive coefficient, p=0.0033) to the regression model significantly increased the ability to predict the proximal medial lateral bone distribution (R2=0.72, p=0.0001). Distally neither the subject characteristics nor the gait moments and predicted forces were significant predictors of the bone distribution. The lack of a correlation distally may be reflective of the forces being more evenly distributed further from the tibial plateau. While it has long been suggested that the adduction moment is the primary determinate of the distribution of load between the medial and lateral plateaus, this is the first evidence of its relationship to the underlying bone distribution.

  18. Percutaneous Stabilization of Impending Pathological Fracture of the Proximal Femur

    SciTech Connect

    Deschamps, Frederic Farouil, Geoffroy Hakime, Antoine Teriitehau, Christophe Barah, Ali Baere, Thierry de

    2012-12-15

    Objective: Percutaneous osteosynthesis plus cementoplasty (POPC) is a minimally invasive technique that has never been reported before and that we have prospectively evaluated for patients with impending pathological fracture of the proximal femur. Methods: We performed POPC in 12 patients (3 males, 9 females) with metastasis of the proximal femur with a high risk of fracture (Mirels' score {>=}8) between February 2010 and July 2011. Patients were not candidates for standard surgical stabilization. We analyzed the feasibility, duration, and complication of the procedure, the risk of fracture, the decrease in pain (Visual Analog Scale, VAS), and length of stay in hospital. Data were prospectively collected in all patients. Results: The mean Mirels' score was 9.8 {+-} 1.2 (range, 8-11). The technical success was 100%. POPC was performed under general anesthesia (n = 6) or conscious sedation (n = 6). The mean duration was 110 {+-} 43 (range, 60-180) minutes. All patients stood up and walked the second day after the procedure. The average length of stay in the hospital was 4 {+-} 1.6 (range, 2-7) days. We experienced two hematomas in two patients and no thromboembolic complication. For symptomatic patients (n = 8), VAS decreased from 6.5/10 (range, 2-9) before treatment to 1/10 (range, 0-3) 1 month after. No fracture occurred after a median follow-up of 145 (range, 12-608) days. Conclusions: POPC for impending pathological fracture of the proximal femur seems to be a promising alternative for cancer patients who are not candidates for surgical stabilization. Further studies are required to confirm this preliminary experience.

  19. 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

  20. Testing Na+ in blood

    PubMed Central

    Lava, Sebastiano A.G.; Bianchetti, Mario G.; Milani, Gregorio P.

    2017-01-01

    Abstract Both direct potentiometry and indirect potentiometry are currently used for Na+ testing in blood. These measurement techniques show good agreement as long as protein and lipid concentrations in blood remain normal. In severely ill patients, indirect potentiometry commonly leads to relevant errors in Na+ estimation: 25% of specimens show a disagreement between direct and indirect potentiometry, which is ≥4 mmol/L (mostly spuriously elevated Na+ level due to low circulating albumin concentration). There is a need for increased awareness of the poor performance of indirect potentiometry in some clinical settings.

  1. Distributed proximity sensor system having embedded light emitters and detectors

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1990-01-01

    A distributed proximity sensor system is provided with multiple photosensitive devices and light emitters embedded on the surface of a robot hand or other moving member in a geometric pattern. By distributing sensors and emitters capable of detecting distances and angles to points on the surface of an object from known points in the geometric pattern, information is obtained for achieving noncontacting shape and distance perception, i.e., for automatic determination of the object's shape, direction and distance, as well as the orientation of the object relative to the robot hand or other moving member.

  2. DIABETIC NEUROPATHY PART 2: PROXIMAL AND ASSYMMETRIC PHENOTYPES

    PubMed Central

    Pasnoor, Mamatha; Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Diabetic neuropathies consist of a variety of syndromes resulting from different types of damage to peripheral or cranial nerves. Although distal symmetric polyneuropathy is most common type of diabetic neuropathy, there are many other subtypes of diabetic neuropathies which have been defined since the 1800’s. Included in these descriptions are patients with proximal diabetic, truncal, cranial, median, and ulnar neuropathies. Various theories have been proposed for the pathogenesis of these neuropathies. The treatment of most of these requires tight and stable glycemic control. Spontaneous recovery is seen in most of these conditions with diabetic control Immunotherapies have been tried in some of these conditions but are quite controversial. PMID:23642718

  3. Using image processing techniques on proximity probe signals in rotordynamics

    NASA Astrophysics Data System (ADS)

    Diamond, Dawie; Heyns, Stephan; Oberholster, Abrie

    2016-06-01

    This paper proposes a new approach to process proximity probe signals in rotordynamic applications. It is argued that the signal be interpreted as a one dimensional image. Existing image processing techniques can then be used to gain information about the object being measured. Some results from one application is presented. Rotor blade tip deflections can be calculated through localizing phase information in this one dimensional image. It is experimentally shown that the newly proposed method performs more accurately than standard techniques, especially where the sampling rate of the data acquisition system is inadequate by conventional standards.

  4. Size and shape variation in Australopithecus afarensis proximal femora.

    PubMed

    Harmon, Elizabeth H

    2006-09-01

    The degree of size and shape variation in the A. afarensis fossil sample has been interpreted in a variety of ways. Size variation has been described as exceeding that of extant hominoids, similar to that of strongly sexually dimorphic hominoids, and best matched to modern humans. The degree of shape variation has been characterized both as great and negligible. Recent fieldwork has increased the proximal femoral sample, providing new data with which to examine variation. The proximal femur of A. afarensis is analyzed in a comparative framework in order to gauge the magnitude of size and shape variation in this element. Seven of the best-preserved A. afarensis proximal femora contribute to the analysis (A.L. 128-1, A.L. 152-2, A.L. 211-1, A.L. 288-1ap, A.L. 333-3, A.L. 333-123, A.L. 827-1). Comparative samples from Pan, Pongo, Gorilla, and Homo provide context for interpreting variation among the fossils. The coefficient of variation (CV) of linear measurements is used to estimate size variation. Bootstrap resampling of CVs from extant hominoids provides distributions for comparison to A. afarensis CVs. Ratios of linear measurements provide scale-free shape variables that are used in pairwise comparisons. The Euclidean distance between pairs of A. afarensis are compared to the Euclidean distances between extant hominoid pairs. As found in some earlier analyses, size variation in A. afarensis is accommodated best in gorillas and orangutans. The magnitude of difference in shape between A. afarensis pairs is exceeded by most taxa, indicating that shape variation is not extreme. These general findings are contradicted by a few instances of excessive size and shape variation. These are uncharacteristic results and could point to temporal bias, although other alternatives are explored. The signal from the proximal femur is that size variation in A. afarensis is like that of the strongly sexually dimorphic apes, and shape variation is well within the range of most

  5. Proximal Humerus Fracture Plating Through the Extended Anterolateral Approach.

    PubMed

    Gardner, Michael J

    2016-08-01

    Several approaches to the proximal humerus for fracture fixation are possible. The traditional utilitarian approach to the shoulder, the deltopectoral, has distinct disadvantages when performing fracture reduction and locked plating. The anterolateral acromial approach exploits the intermuscular plane between the anterior and middle heads of the deltoid. After identifying the position of the axillary nerve as it crosses this interval, fracture reduction and fixation is performed. Direct access to both the greater and the lesser tuberosities is facilitated. The cancellous surface of the humeral head fragment provides an excellent surface for direct manipulation without further endangering the extraosseous soft tissue attachments.

  6. [Fibrocartilaginous mesenchymoma of the proximal humerus: case report].

    PubMed

    Masquijo, Julio Javier; Sartori, Federico; Innocenti, Sergio

    2014-10-01

    Fibrocartilaginous mesenchymoma (FCM) is a rare tumor that primarily affects the long bones. Few cases have been reported since its description. A case of a 4-year-old boy with FCM located in the humerus is presented. Radiological examination showed an expansive lytic lesion located in the metaphyseal proximal humerus. Magnetic resonance imaging showed soft tissue expansion. Histopathological diagnosis was confirmatory of FCM. Curettage, adjuvant phenolization, and bone grafting with bone substitute, and autologous bone marrow was performed. During a follow-up period of 2 years, there was no evidence of disease progression. FCM should be considered in the differential diagnosis of lytic bone lesions in children and adolescents.

  7. A General Simulation Method for Multiple Bodies in Proximate Flight

    NASA Technical Reports Server (NTRS)

    Meakin, Robert L.

    2003-01-01

    Methods of unsteady aerodynamic simulation for an arbitrary number of independent bodies flying in close proximity are considered. A novel method to efficiently detect collision contact points is described. A method to compute body trajectories in response to aerodynamic loads, applied loads, and inter-body collisions is also given. The physical correctness of the methods are verified by comparison to a set of analytic solutions. The methods, combined with a Navier-Stokes solver, are used to demonstrate the possibility of predicting the unsteady aerodynamics and flight trajectories of moving bodies that involve rigid-body collisions.

  8. 4. MESOSCOPIC SUPERCONDUCTIVITY: Proximity Action theory of superconductive nanostructures

    NASA Astrophysics Data System (ADS)

    Skvortsov, M. A.; Larkin, A. I.; Feigel'man, M. V.

    2001-10-01

    We review a novel approach to the superconductive proximity effect in disordered normal-superconducting (N-S) structures. The method is based on the multicharge Keldysh action and is suitable for the treatment of interaction and fluctuation effects. As an application of the formalism, we study the subgap conductance and noise in two-dimensional N-S systems in the presence of the electron-electron interaction in the Cooper channel. It is shown that singular nature of the interaction correction at large scales leads to a nonmonotonuos temperature, voltage and magnetic field dependence of the Andreev conductance.

  9. Tractable Algorithms for Proximity Search on Large Graphs

    DTIC Science & Technology

    2010-07-01

    bounds enable us to expand the neighborhood in an adaptive fashion, i.e. include “potential” nearest neigh- bors . As the neighborhood is expanded these...All these applications require ranking, i.e. computing nearest neigh- bors under a given measure. While random walk based proximity measures like...assume that we want to find the k nearest neigh- bors of node i within T ′. In Figure 3.2 we plot the lower and upper bounds of hi,j , in the order of

  10. Proximity effect thermometer for local temperature measurements on mesoscopic samples.

    SciTech Connect

    Aumentado, J.; Eom, J.; Chandrasekhar, V.; Baldo, P. M.; Rehn, L. E.; Materials Science Division; Northwestern Univ; Univ. of Chicago

    1999-11-29

    Using the strong temperature-dependent resistance of a normal metal wire in proximity to a superconductor, we have been able to measure the local temperature of electrons heated by flowing a direct-current (dc) in a metallic wire to within a few tens of millikelvin at low temperatures. By placing two such thermometers at different parts of a sample, we have been able to measure the temperature difference induced by a dc flowing in the samples. This technique may provide a flexible means of making quantitative thermal and thermoelectric measurements on mesoscopic metallic samples.

  11. Cascading failures in networks with proximate dependent nodes

    NASA Astrophysics Data System (ADS)

    Kornbluth, Yosef; Lowinger, Steven; Cwilich, Gabriel; Buldyrev, Sergey V.

    2014-03-01

    We study the mutual percolation of a system composed of two interdependent random regular networks. We introduce a notion of distance to explore the effects of the proximity of interdependent nodes on the cascade of failures after an initial attack. We find a nontrivial relation between the nature of the transition through which the networks disintegrate and the parameters of the system, which are the degree of the nodes and the maximum distance between interdependent nodes. We explain this relation by solving the problem analytically for the relevant set of cases. In the process, we solve a variant of Rényi's parking problem on treelike graphs.

  12. [Tomodensitometry measurements of proximal tibia and acceleration in marathon athletes].

    PubMed

    Gremion, Gérald; Cordey, Jacques; Leyvraz, Pierre-François; Rizzoli, René; Crettenand, Antoinette; Gobelet, Charles; Dériaz, Olivier; Crettenand, Andre

    2004-02-01

    We evaluated bone adaptation of the tibia to mechanical stresses in male marathon runners and in sedentary controls in function of the ground impact measured by accelerometry and of the bone mineral density assessed by peripheral quantitative computed tomography (QCT). Sixty-three subjects (51 runners and 12 controls) were enrolled. All had measurements of bone mineral density of the proximal tibia and of acceleration at the same site during a jogging at 9 km/hour. The results show a significant higher cortical BMD in runners with the higher value of late accelerations (at 50 ms after the contact with the ground). The late acceleration might be related to muscle contraction.

  13. Outcome of closed proximal phalangeal fractures of the hand

    PubMed Central

    Singh, Jaswinder; Jain, Karun; Mruthyunjaya; Ravishankar, R

    2011-01-01

    Background: The proximal phalanx (PP) of the fingers is fractured more frequently than the middle or even distal phalanges. The problems of malunion, stiffness and sometimes loss of skin or other soft tissues associated with PP fracture increases the disability. The optimum treatment depends on fracture location, fracture geometry and fracture stability. The objective of the study was to analyse the treatment outcome in a series of closed proximal phalangeal fractures of the hand. Materials and Methods: Eighty-four proximal phalangeal fractures in 68 patients were enrolled from 2007 to 2009. The treatment modalities were broadly categorised into two groups, Group A consisted of conservative treatment, and Group B consisted of surgical treatment. Group A included 47 digits treated with closed reduction (CR) with immobilization (n=43), extension block cast and dynamic traction (n=4), while 37 digits were treated in Group B, which included closed or open reduction (OR) and internal fixation (IF) with K-wires (n=31), OR and IF with stainless-steel wiring (n=2), and mini external-fixator (n=4). Belsky's criteria and Gingrass’ criteria were used for assessment of finger injuries and to assess the efficacy of conservative and surgical modalities for closed proximal phalangeal fractures of the hand. Results: Average period of follow-up was 1 year (range 10-14 months). The excellent to good results seen in Groups A and B were 89% and 92%, respectively. Six complications were seen in Group A, which included four cases with malunion and two cases with digital stiffness. Three complications were seen in Group B, which included one each of malunion, digital stiffness and extensor lag. Overall, maximum poor results (n=4) were seen with CR and buddy strapping. Conclusion: Conservative treatment is an inexpensive method, particularly suitable for stable fractures, and in patients who are poor candidates for surgery, Surgical modalities have distinct advantage of stable fixation

  14. 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.

  15. Outcome Analysis of Locking Plate Fixation in Proximal Humerus Fracture

    PubMed Central

    Pathak, Abhishek; Gaur, Sanjiv

    2016-01-01

    Introduction Proximal humerus fractures account for approximately 5% of all fractures. Stable minimally displaced fractures can be treated nonoperatively but the management of displaced fractures remain controversial with various modalities of treatment available. Locking plates provide stable fixation and enable early postoperative mobilization specially in osteoporotic proximal humerus fracture. Aim To evaluate the functional outcome of locking plate fixation and to compare the results of two approaches used for fixation. Materials and Methods This prospective study was conducted at a tertiary level hospital between September 2011 to December 2013. PHILOS plates were used for internal fixation of displaced proximal humerus fractures Neer’s type 2 part, 3 part and 4 part fractures on 26 patients (M/F ratio 1.36:1; mean age 46 years). According to Neer classification, 5,12 and 9 patients had displaced 2, 3 and 4 part fractures respectively. Deltopectoral and deltoid splitting approaches were used for fixation on 13 patients each. Functional outcome was assessed using Constant-Murley shoulder score. Graphpad software version 6.0 was used with Chi-square test and Fisher-exact test are used to compare data. The p-value< 0.05 is considered significant. Results Of the 26 patients, all fractures united radiologically and clinically and average constant score at final follow-up was 72.5. At the final follow-up 8 patients had good score, 10 patients had moderate score, 6 patients had excellent outcome and 2 patients had poor outcome according to Constant score. Mean time to union was 12.3 weeks (9 –15 weeks). Four complications (15.4%) were encountered, 2 cases of varus malunion, 1 case of wound infection which required wound debridement and 1 case of screw cut-out in which screw removal was done. Mean constant score in delto splitting approach was 70.9 and 74 in deltopectoral group (p-value= 0.54). No significant difference existed in constant score in 2 approaches

  16. Endoluminal vacuum therapy for iatrogenic perforation of the proximal oesophagus.

    PubMed

    Möschler, O; Müller, M K

    2014-03-01

    Iatrogenic perforation of the upper gastrointestinal tract is one of the most serious complications of upper gastrointestinal endoscopy, with high rates of morbidity and mortality. Treatment is challenging because stent placement or surgical repair of the perforation in this area is often impossible. We report on two cases of iatrogenic perforations of the very proximal oesophagus and distal hypopharynx which could be successfully closed by using an endoluminal vacuum sponge treatment for 5 days. Thus, the endoluminal vacuum therapy may be a useful alternative to surgery in such cases of difficultly managable perforations of the upper oesophagus.

  17. Benign monomelic amyotrophy with proximal upper limb involvement: case report.

    PubMed

    Neves, Marco Antonio Orsini; Freitas, Marcos R G de; Mello, Mariana Pimentel de; Dumard, Carlos Henrique; Freitas, Gabriel R de; Nascimento, Osvaldo J M

    2007-06-01

    Monomelic amyotrophy (MA) is a rare condition in which neurogenic amyotrophy is restricted to an upper or lower limb. Usually sporadic, it usually has an insidious onset with a mean evolution of 2 to 4 years following first clinical manifestations, which is, in turned, followed by stabilization. We report a case of 20-years-old man who presented slowly progressive amyotrophy associated with proximal paresis of the right upper limb, which was followed by clinical stabilization 4 years later. Eletroneuromyography revealed denervation along with myofasciculations in various muscle groups of the right upper limb. We call attention to this rare location of MA, as well as describe some theories concerning its pathophysiology .

  18. Pseudocontractions in the intermediate sense: Fixed and best proximity points

    NASA Astrophysics Data System (ADS)

    De la Sen, Manuel

    2013-09-01

    This paper studies a general contractive condition for a class of two-cyclic self-maps on the union of a finite number of subsets of a metric space which are allowed to have a finite number of successive images in the same subsets of its domain. If the space is uniformly convex and the subsets are non-empty, closed and convex then all the iterated sequences are proved to converge to a unique closed limiting finite sequence. Such a sequence contains the best proximity points of adjacent subsets which coincide with a unique fixed point if all such subsets intersect.

  19. STM/STS on proximity-coupled superconducting graphene

    NASA Astrophysics Data System (ADS)

    Ovadia, Maoz; Ji, Yu; Lee, Gil-Ho; Fang, Wenjing; Hoffman, Jennifer; Jarillo-Herrero, Pablo; Kong, Jing; Kim, Philip

    Graphene in good electrical contact with a superconductor has been observed to have an enhanced proximity effect. Application of a magnetic field is expected to generate an Abrikosov lattice of superconducting vortices, each containing Andreev bound states in its core. With our versatile, homebuilt, low temperature scanning tunneling force microscope (STM/SFM), we investigate the electronic properties of graphene on superconducting NbSe2 in a magnetic field and search for signatures of these vortex core states. This work was supported by the STC Center for Integrated Quantum Materials, NSF Grant No. DMR-1231319.

  20. Proximate and elemental analysis of five selected medicinal plants of family Solanaceae.

    PubMed

    Hameed, Ishfaq; Hussain, Farrukh

    2015-07-01

    The proximate analysis revealed the presence of ash, moisture, protein, fiber, fats and carbohydrate. ANOVA showed that ash and moisture contents was non significant between the plant parts and phenological stages. Crude protein was non significant between the plant parts and phenological stages except for Datura innoxia parts but not for its phenolgical stages, while crude fats were non significant between the plant parts and phenological stages except for Solanum nigrum and Solanum surattense parts but not for their phenolgical stages. Crude fiber was non significant between the plant parts and phenological stages except for Datura innoxia parts but not for its phenolgical stages. And carbohydrates was non significant between the plant parts and phenological stages except for the phenolgical stages of Solanum surattense and Withania coagulans. The mineral analysis showed the presence of Cr, Zn, Cu, Mn, Fe, Ca, K, Mg and Na in the roots, stems, leaves, flowers and fruits of the plants in three different phenological stages. Only the micro-minerals were present in traces while the macro-minerals were present high quantities as compared to the micro-minerals.

  1. An Auditory Illusion of Proximity of the Source Induced by Sonic Crystals.

    PubMed

    Spiousas, Ignacio; Etchemendy, Pablo E; Vergara, Ramiro O; Calcagno, Esteban R; Eguia, Manuel C

    2015-01-01

    In this work we report an illusion of proximity of a sound source created by a sonic crystal placed between the source and a listener. This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers. Even when the singular acoustical properties of these periodic composite materials have been studied extensively (including band gaps, deaf bands, negative refraction, and birrefringence), the possible perceptual effects remain unexplored. The illusion reported here is studied through acoustical measurements and a psychophysical experiment. The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance. Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source.

  2. Sub-micrometer resolution proximity X-ray microscope with digital image registration

    SciTech Connect

    Chkhalo, N. I.; Salashchenko, N. N.; Sherbakov, A. V. Svechnikov, M. V.; Pestov, A. E.; Skorokhodov, E. V.

    2015-06-15

    A compact laboratory proximity soft X-ray microscope providing submicrometer spatial resolution and digital image registration is described. The microscope consists of a laser-plasma soft X-ray radiation source, a Schwarzschild objective to illuminate the test sample, and a two-coordinate detector for image registration. Radiation, which passes through the sample under study, generates an absorption image on the front surface of the detector. Optical ceramic YAG:Ce was used to convert the X-rays into visible light. An image was transferred from the scintillator to a charge-coupled device camera with a Mitutoyo Plan Apo series lens. The detector’s design allows the use of lenses with numerical apertures of NA = 0.14, 0.28, and 0.55 without changing the dimensions and arrangement of the elements of the device. This design allows one to change the magnification, spatial resolution, and field of view of the X-ray microscope. A spatial resolution better than 0.7 μm and an energy conversion efficiency of the X-ray radiation with a wavelength of 13.5 nm into visible light collected by the detector of 7.2% were achieved with the largest aperture lens.

  3. Sub-micrometer resolution proximity X-ray microscope with digital image registration.

    PubMed

    Chkhalo, N I; Pestov, A E; Salashchenko, N N; Sherbakov, A V; Skorokhodov, E V; Svechnikov, M V

    2015-06-01

    A compact laboratory proximity soft X-ray microscope providing submicrometer spatial resolution and digital image registration is described. The microscope consists of a laser-plasma soft X-ray radiation source, a Schwarzschild objective to illuminate the test sample, and a two-coordinate detector for image registration. Radiation, which passes through the sample under study, generates an absorption image on the front surface of the detector. Optical ceramic YAG:Ce was used to convert the X-rays into visible light. An image was transferred from the scintillator to a charge-coupled device camera with a Mitutoyo Plan Apo series lens. The detector's design allows the use of lenses with numerical apertures of NA = 0.14, 0.28, and 0.55 without changing the dimensions and arrangement of the elements of the device. This design allows one to change the magnification, spatial resolution, and field of view of the X-ray microscope. A spatial resolution better than 0.7 μm and an energy conversion efficiency of the X-ray radiation with a wavelength of 13.5 nm into visible light collected by the detector of 7.2% were achieved with the largest aperture lens.

  4. Nb/InAs nanowire proximity junctions from Josephson to quantum dot regimes.

    PubMed

    Gharavi, Kaveh; Holloway, Gregory W; LaPierre, Ray R; Baugh, Jonathan

    2017-02-24

    The superconducting proximity effect is probed experimentally in Josephson junctions fabricated with InAs nanowires contacted by Nb leads. Contact transparencies [Formula: see text] are observed. The electronic phase coherence length at low temperatures exceeds the channel length. However, the elastic scattering length is a few times shorter than the channel length. Electrical measurements reveal two regimes of quantum transport: (i) the Josephson regime, characterised by a dissipationless current up to ∼100 nA, and (ii) the quantum dot (QD) regime, characterised by the formation of Andreev bound states (ABS) associated with spontaneous QDs inside the nanowire channel. In regime (i), the behaviour of the critical current I c versus an axial magnetic field [Formula: see text] shows an unexpected modulation and persistence to fields [Formula: see text] T. In the QD regime, the ABS are modelled as the current-biased solutions of an Anderson-type model. The applicability of devices in both transport regimes to Majorana fermion experiments is discussed.

  5. Water reabsorption capacity of the proximal convoluted tubule: a microperfusion study on rat kidney.

    PubMed Central

    Corman, B; Roinel, N; De Rouffignac, C

    1981-01-01

    1. The differences in the water reabsorption capacity observed from one proximal tubule to another were investigated in vivo by continuous microperfusion. 2. Two to seven loops were punctured along the same tubule. The [3H]inulin, 22Na, [14C]glucose, sodium, chloride and magnesium concentrations as well as the osmolality of the collected samples were studied as a function of the perfused length. 3. With Ringer bicarbonate solution perfused in Saclay Wistar rats, the water reabsorption capacity ranged from 0 to 3 nl . min-1 . mm-1 depending on the tubule. This reabsorption rate was closely correlated with the unidirectional reabsorption flux of sodium, and with the rise in tubular chloride and magnesium concentrations. 4. In Munich Wistar rats with glomeruli accessible at the kidney surface, tubule perfusion with a Ringer bicarbonate solution showed that the highest water reabsorption rates per mm of tubule were found for the perfusion sites closest to the glomerulus; water fluxes were also positively correlated with glucose transport. 5. In a second series of experiments on Saclay rats, perfusion of a Ringer solution containing a high chloride concentration (137 m-equiv/l.) was unable to increase the water reabsorption rate compared to the control perfusion; here again, water fluxes were positively correlated with glucose transport. PMID:7320874

  6. An Auditory Illusion of Proximity of the Source Induced by Sonic Crystals

    PubMed Central

    Spiousas, Ignacio; Etchemendy, Pablo E.; Vergara, Ramiro O.; Calcagno, Esteban R.; Eguia, Manuel C.

    2015-01-01

    In this work we report an illusion of proximity of a sound source created by a sonic crystal placed between the source and a listener. This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers. Even when the singular acoustical properties of these periodic composite materials have been studied extensively (including band gaps, deaf bands, negative refraction, and birrefringence), the possible perceptual effects remain unexplored. The illusion reported here is studied through acoustical measurements and a psychophysical experiment. The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance. Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source. PMID:26222281

  7. Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism.

    PubMed

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E; Lamers, Wouter H; Chaudhry, Farrukh A; Verlander, Jill W; Weiner, I David

    2016-06-01

    Glutamine synthetase (GS) catalyzes the recycling of NH4 (+) with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of the present study was to determine the role of PT GS in ammonia metabolism under basal conditions and during metabolic acidosis. We generated mice with PT-specific GS deletion (PT-GS-KO) using Cre-loxP techniques. Under basal conditions, PT-GS-KO increased urinary ammonia excretion significantly. Increased ammonia excretion occurred despite decreased expression of key proteins involved in renal ammonia generation. After the induction of metabolic acidosis, the ability to increase ammonia excretion was impaired significantly by PT-GS-KO. The blunted increase in ammonia excretion occurred despite greater expression of multiple components of ammonia generation, including SN1 (Slc38a3), phosphate-dependent glutaminase, phosphoenolpyruvate carboxykinase, and Na(+)-coupled electrogenic bicarbonate cotransporter. We conclude that 1) GS-mediated ammonia recycling in the PT contributes to both basal and acidosis-stimulated ammonia metabolism and 2) adaptive changes in other proteins involved in ammonia metabolism occur in response to PT-GS-KO and cause an underestimation of the role of PT GS expression.

  8. Proximate Composition, Amino Acid, Mineral, and Heavy Metal Content of Dried Laver

    PubMed Central

    Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull

    2013-01-01

    Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and γ-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals. PMID:24471123

  9. Probing nuclear pore complex architecture with proximity-dependent biotinylation.

    PubMed

    Kim, Dae In; Birendra, K C; Zhu, Wenhong; Motamedchaboki, Khatereh; Doye, Valérie; Roux, Kyle J

    2014-06-17

    Proximity-dependent biotin identification (BioID) is a method for identifying protein associations that occur in vivo. By fusing a promiscuous biotin ligase to a protein of interest expressed in living cells, BioID permits the labeling of proximate proteins during a defined labeling period. In this study we used BioID to study the human nuclear pore complex (NPC), one of the largest macromolecular assemblies in eukaryotes. Anchored within the nuclear envelope, NPCs mediate the nucleocytoplasmic trafficking of numerous cellular components. We applied BioID to constituents of the Nup107-160 complex and the Nup93 complex, two conserved NPC subcomplexes. A strikingly different set of NPC constituents was detected depending on the position of these BioID-fusion proteins within the NPC. By applying BioID to several constituents located throughout the extremely stable Nup107-160 subcomplex, we refined our understanding of this highly conserved subcomplex, in part by demonstrating a direct interaction of Nup43 with Nup85. Furthermore, by using the extremely stable Nup107-160 structure as a molecular ruler, we defined the practical labeling radius of BioID. These studies further our understanding of human NPC organization and demonstrate that BioID is a valuable tool for exploring the constituency and organization of large protein assemblies in living cells.

  10. A positioned +1 nucleosome enhances promoter-proximal pausing.

    PubMed

    Jimeno-González, Silvia; Ceballos-Chávez, María; Reyes, José C

    2015-03-31

    Chromatin distribution is not uniform along the human genome. In most genes there is a promoter-associated nucleosome free region (NFR) followed by an array of nucleosomes towards the gene body in which the first (+1) nucleosome is strongly positioned. The function of this characteristic chromatin distribution in transcription is not fully understood. Here we show in vivo that the +1 nucleosome plays a role in modulating RNA polymerase II (RNAPII) promoter-proximal pausing. When a +1 nucleosome is strongly positioned, elongating RNAPII has a tendency to stall at the promoter-proximal region, recruits more negative elongation factor (NELF) and produces less mRNA. The nucleosome-induced pause favors pre-mRNA quality control by promoting the addition of the cap to the nascent RNA. Moreover, the uncapped RNAs produced in the absence of a positioned nucleosome are degraded by the 5'-3' exonuclease XRN2. Interestingly, reducing the levels of the chromatin remodeler ISWI factor SNF2H decreases +1 nucleosome positioning and increases RNAPII pause release. This work demonstrates a function for +1 nucleosome in regulation of transcription elongation, pre-mRNA processing and gene expression.

  11. Proximity-Induced Shiba States in a Molecular Junction

    NASA Astrophysics Data System (ADS)

    Island, Joshua O.; Gaudenzi, Rocco; de Bruijckere, Joeri; Burzurí, Enrique; Franco, Carlos; Mas-Torrent, Marta; Rovira, Concepció; Veciana, Jaume; Klapwijk, Teun M.; Aguado, Ramón; van der Zant, Herre S. J.

    2017-03-01

    Superconductors containing magnetic impurities exhibit intriguing phenomena derived from the competition between Cooper pairing and Kondo screening. At the heart of this competition are the Yu-Shiba-Rusinov (Shiba) states which arise from the pair breaking effects a magnetic impurity has on a superconducting host. Hybrid superconductor-molecular junctions offer unique access to these states but the added complexity in fabricating such devices has kept their exploration to a minimum. Here, we report on the successful integration of a model spin 1 /2 impurity, in the form of a neutral and stable all organic radical molecule, in proximity-induced superconducting break junctions. Our measurements reveal excitations which are characteristic of a spin-induced Shiba state due to the radical's unpaired spin strongly coupled to a superconductor. By virtue of a variable molecule-electrode coupling, we access both the singlet and doublet ground states of the hybrid system which give rise to the doublet and singlet Shiba excited states, respectively. Our results show that Shiba states are a robust feature of the interaction between a paramagnetic impurity and a proximity-induced superconductor where the excited state is mediated by correlated electron-hole (Andreev) pairs instead of Cooper pairs.

  12. Cassini at Saturn Proximal Orbits - Attitude Control Challenges

    NASA Technical Reports Server (NTRS)

    Burk, Thomas A.

    2013-01-01

    The Cassini mission at Saturn will come to an end in the spring and summer of 2017 with a series of 22 orbits that will dip inside the rings of Saturn. These are called proximal orbits and will conclude with spacecraft disposal into the atmosphere of the ringed world on September 15, 2017. These unique orbits that cross the ring plane only a few thousand kilometers above the cloud tops of the planet present new attitude control challenges for the Cassini operations team. Crossing the ring plane so close to the inner edge of the rings means that the Cassini orientation during the crossing will be tailored to protect the sensitive electronics bus of the spacecraft. This orientation will put the sun sensors at some extra risk so this paper discusses how the team prepares for dust hazards. Periapsis is so close to the planet that spacecraft controllability with RCS thrusters needs to be evaluated because of the predicted atmospheric torque near closest approach to Saturn. Radiation during the ring plane crossings will likely trigger single event transients in some attitude control sensors. This paper discusses how the attitude control team deals with radiation hazards. The angular size and unique geometry of the rings and Saturn near periapsis means that star identification will be interrupted and this paper discusses how the safe mode attitude is selected to best deal with these large bright bodies during the proximal orbits.

  13. Modulation of hydrophobic interactions by proximally immobilized ions.

    PubMed

    Ma, C Derek; Wang, Chenxuan; Acevedo-Vélez, Claribel; Gellman, Samuel H; Abbott, Nicholas L

    2015-01-15

    The structure of water near non-polar molecular fragments or surfaces mediates the hydrophobic interactions that underlie a broad range of interfacial, colloidal and biophysical phenomena. Substantial progress over the past decade has improved our understanding of hydrophobic interactions in simple model systems, but most biologically and technologically relevant structures contain non-polar domains in close proximity to polar and charged functional groups. Theories and simulations exploring such nanometre-scale chemical heterogeneity find it can have an important effect, but the influence of this heterogeneity on hydrophobic interactions has not been tested experimentally. Here we report chemical force microscopy measurements on alkyl-functionalized surfaces that reveal a dramatic change in the surfaces' hydrophobic interaction strengths on co-immobilization of amine or guanidine groups. Protonation of amine groups doubles the strength of hydrophobic interactions, and guanidinium groups eliminate measurable hydrophobic interactions in all pH ranges investigated. We see these divergent effects of proximally immobilized cations also in single-molecule measurements on conformationally stable β-peptides with non-polar subunits located one nanometre from either amine- or guanidine-bearing subunits. Our results demonstrate the importance of nanometre-scale chemical heterogeneity, with hydrophobicity not an intrinsic property of any given non-polar domain but strongly modulated by functional groups located as far away as one nanometre. The judicious placing of charged groups near hydrophobic domains thus provides a strategy for tuning hydrophobic driving forces to optimize molecular recognition or self-assembly processes.

  14. A proximal activator of transcription in epithelial-mesenchymal transition

    PubMed Central

    Venkov, Christo D.; Link, Andrew J.; Jennings, Jennifer L.; Plieth, David; Inoue, Tsutomu; Nagai, Kojiro; Xu, Carol; Dimitrova, Yoana N.; Rauscher, Frank J.; Neilson, Eric G.

    2007-01-01

    Epithelial-mesenchymal transition (EMT) is an important mechanism for phenotypic conversion in normal development and disease states such as tissue fibrosis and metastasis. While this conversion of epithelia is under tight transcriptional control, few of the key transcriptional proteins are known. Fibroblasts produced by EMT express a gene encoding fibroblast-specific protein 1 (FSP1), which is regulated by a proximal cis-acting promoter element called fibroblast transcription site–1 (FTS-1). In mass spectrometry, chromatin immunoprecipitation, and siRNA studies, we used FTS-1 as a unique probe for mediators of EMT and identified a complex of 2 proteins, CArG box–binding factor–A (CBF-A) and KRAB-associated protein 1 (KAP-1), that bind this site. Epithelial cells engineered to conditionally express recombinant CBF-A (rCBF-A) activate the transcription of FSP1 and undergo EMT. The FTS-1 response element also exists in the promoters modulating a broader EMT transcriptome, including Twist, and Snail, as well as E-cadherin, β-catenin, ZO 1, vimentin, α1(I) collagen, and α–smooth muscle actin, and the induction of rCBF-A appropriately alters their expression as well. We believe formation of the CBF-A/KAP-1/FTS-1 complex is sufficient for the induction of FSP1 and a novel proximal activator of EMT. PMID:17273560

  15. A proximal activator of transcription in epithelial-mesenchymal transition.

    PubMed

    Venkov, Christo D; Link, Andrew J; Jennings, Jennifer L; Plieth, David; Inoue, Tsutomu; Nagai, Kojiro; Xu, Carol; Dimitrova, Yoana N; Rauscher, Frank J; Neilson, Eric G

    2007-02-01

    Epithelial-mesenchymal transition (EMT) is an important mechanism for phenotypic conversion in normal development and disease states such as tissue fibrosis and metastasis. While this conversion of epithelia is under tight transcriptional control, few of the key transcriptional proteins are known. Fibroblasts produced by EMT express a gene encoding fibroblast-specific protein 1 (FSP1), which is regulated by a proximal cis-acting promoter element called fibroblast transcription site-1 (FTS-1). In mass spectrometry, chromatin immunoprecipitation, and siRNA studies, we used FTS-1 as a unique probe for mediators of EMT and identified a complex of 2 proteins, CArG box-binding factor-A (CBF-A) and KRAB-associated protein 1 (KAP-1), that bind this site. Epithelial cells engineered to conditionally express recombinant CBF-A (rCBF-A) activate the transcription of FSP1 and undergo EMT. The FTS-1 response element also exists in the promoters modulating a broader EMT transcriptome, including Twist, and Snail, as well as E-cadherin, beta-catenin, ZO 1, vimentin, alpha1(I) collagen, and alpha-smooth muscle actin, and the induction of rCBF-A appropriately alters their expression as well. We believe formation of the CBF-A/KAP-1/FTS-1 complex is sufficient for the induction of FSP1 and a novel proximal activator of EMT.

  16. Acid-base transport by the renal proximal tubule

    PubMed Central

    Skelton, Lara A.; Boron, Walter F.; Zhou, Yuehan

    2015-01-01

    Each day, the kidneys filter 180 L of blood plasma, equating to some 4,300 mmol of the major blood buffer, bicarbonate (HCO3−). The glomerular filtrate enters the lumen of the proximal tubule (PT), and the majority of filtered HCO3− is reclaimed along the early (S1) and convoluted (S2) portions of the PT in a manner coupled to the secretion of H+ into the lumen. The PT also uses the secreted H+ to titrate non-HCO3− buffers in the lumen, in the process creating “new HCO3−” for transport into the blood. Thus, the PT – along with more distal renal segments – is largely responsible for regulating plasma [HCO3−]. In this review we first focus on the milestone discoveries over the past 50+ years that define the mechanism and regulation of acid-base transport by the proximal tubule. Further on in the review, we will summarize research still in progress from our laboratory, work that addresses the problem of how the PT is able to finely adapt to acid–base disturbances by rapidly sensing changes in basolateral levels of HCO3− and CO2 (but not pH), and thereby to exert tight control over the acid–base composition of the blood plasma. PMID:21170887

  17. Promoter-proximal polyadenylation sites reduce transcription activity

    PubMed Central

    Andersen, Pia K.; Lykke-Andersen, Søren; Jensen, Torben Heick

    2012-01-01

    Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site, which in turn causes reduced transcription. Functional depletion of U1 snRNP in the context of the wild-type SD triggers the same CpA event accompanied by decreased RNA levels. Thus, in accordance with recent findings, U1 snRNP can shield premature pA sites. The negative impact of unshielded pA sites on transcription requires promoter proximity, as demonstrated using artificial constructs and supported by a genome-wide data set. Importantly, transcription down-regulation can be recapitulated in a gene context devoid of splice sites by placing a functional bona fide pA site/transcription terminator within ∼500 base pairs of the promoter. In contrast, promoter-proximal positioning of a pA site-independent histone gene terminator supports high transcription levels. We propose that optimal communication between a pA site-dependent gene terminator and its promoter critically depends on gene length and that short RNA polymerase II-transcribed genes use specialized termination mechanisms to maintain high transcription levels. PMID:23028143

  18. ADAM17 substrate release in proximal tubule drives kidney fibrosis

    PubMed Central

    Kefaloyianni, Eirini; Muthu, Muthu Lakshmi; Kaeppler, Jakob; Sun, Xiaoming; Sabbisetti, Venkata; Chalaris, Athena; Rose-John, Stefan; Wong, Eitan; Sagi, Irit; Waikar, Sushrut S.; Rennke, Helmut; Bonventre, Joseph V.

    2016-01-01

    Kidney fibrosis following kidney injury is an unresolved health problem and causes significant morbidity and mortality worldwide. In a study into its molecular mechanism, we identified essential causative features. Acute or chronic kidney injury causes sustained elevation of a disintegrin and metalloprotease 17 (ADAM17); of its cleavage-activated proligand substrates, in particular of pro-TNFα and the EGFR ligand amphiregulin (pro-AREG); and of the substrates’ receptors. As a consequence, EGFR is persistently activated and triggers the synthesis and release of proinflammatory and profibrotic factors, resulting in macrophage/neutrophil ingress and fibrosis. ADAM17 hypomorphic mice, specific ADAM17 inhibitor–treated WT mice, or mice with inducible KO of ADAM17 in proximal tubule (Slc34a1-Cre) were significantly protected against these effects. In vitro, in proximal tubule cells, we show that AREG has unique profibrotic actions that are potentiated by TNFα-induced AREG cleavage. In vivo, in acute kidney injury (AKI) and chronic kidney disease (CKD, fibrosis) patients, soluble AREG is indeed highly upregulated in human urine, and both ADAM17 and AREG expression show strong positive correlation with fibrosis markers in related kidney biopsies. Our results indicate that targeting of the ADAM17 pathway represents a therapeutic target for human kidney fibrosis. PMID:27642633

  19. Modulation of hydrophobic interactions by proximally immobilized ions

    NASA Astrophysics Data System (ADS)

    Ma, C. Derek; Wang, Chenxuan; Acevedo-Vélez, Claribel; Gellman, Samuel H.; Abbott, Nicholas L.

    2015-01-01

    The structure of water near non-polar molecular fragments or surfaces mediates the hydrophobic interactions that underlie a broad range of interfacial, colloidal and biophysical phenomena. Substantial progress over the past decade has improved our understanding of hydrophobic interactions in simple model systems, but most biologically and technologically relevant structures contain non-polar domains in close proximity to polar and charged functional groups. Theories and simulations exploring such nanometre-scale chemical heterogeneity find it can have an important effect, but the influence of this heterogeneity on hydrophobic interactions has not been tested experimentally. Here we report chemical force microscopy measurements on alkyl-functionalized surfaces that reveal a dramatic change in the surfaces' hydrophobic interaction strengths on co-immobilization of amine or guanidine groups. Protonation of amine groups doubles the strength of hydrophobic interactions, and guanidinium groups eliminate measurable hydrophobic interactions in all pH ranges investigated. We see these divergent effects of proximally immobilized cations also in single-molecule measurements on conformationally stable β-peptides with non-polar subunits located one nanometre from either amine- or guanidine-bearing subunits. Our results demonstrate the importance of nanometre-scale chemical heterogeneity, with hydrophobicity not an intrinsic property of any given non-polar domain but strongly modulated by functional groups located as far away as one nanometre. The judicious placing of charged groups near hydrophobic domains thus provides a strategy for tuning hydrophobic driving forces to optimize molecular recognition or self-assembly processes.

  20. Rotor Vortex Wake in Close Proximity of Walls in Hover

    NASA Astrophysics Data System (ADS)

    Konus, Mehmet Fatih; Savas, Omer

    2014-11-01

    Expanding flight envelopes of rotorcraft raise concerns about their behavior in very close proximity of walls or corners where the separation between the wall and the rotor disk can almost vanish. A series of experiments are conducted in a water tank to study the hover behavior of the wake of a 25-cm diameter three-bladed rotor at 8 rev/s. Particle image velocimetry, strain gage force balance measurements and flow visualization are employed. The vortex wake, which is axisymmetric on the average in an unbounded surrounding, is distorted increasingly with decreasing separation from a wall or corner. The vortex wake bends toward the wall and into the corner. The individual helical filaments off the rotor tips are distorted and closely follow the wall. Intermittent reversed vortical flow regions appear upstream of the rotor disk in the proximity of the wall. The mean streamlines indicate that the wake is bent toward the wall or into the corner. The component of the thrust vector along the axis of the rotor decreases. These observation suggest that the thrust vector progressively deviates from the geometric axis of the rotor.

  1. Orion Handling Qualities During ISS Proximity Operations and Docking

    NASA Technical Reports Server (NTRS)

    Stephens, John-Paul; Vos, Gordon A.; Bilimoria, Karl D.; Mueller, Eric R.; Brazzel, Jack; Spehar, Pete

    2011-01-01

    NASA's Orion spacecraft is designed to autonomously rendezvous and dock with many vehicles including the International Space Station. However, the crew is able to assume manual control of the vehicle s attitude and flight path. In these instances, Orion must meet handling qualities requirements established by NASA. Two handling qualities assessments were conducted at the Johnson Space Center to evaluate preliminary designs of the vehicle using a six degree of freedom, high-fidelity guidance, navigation, and control simulation. The first assessed Orion s handling qualities during the last 20 ft before docking, and included both steady and oscillatory motions of the docking target. The second focused on manual acquisition of the docking axis during the proximity operations phase and subsequent station-keeping. Cooper-Harper handling qualities ratings, workload ratings and comments were provided by 10 evaluation pilots for the docking study and 5 evaluation pilots for the proximity operations study. For the docking task, both cases received 90% Level 1 (satisfactory) handling qualities ratings, exceeding NASA s requirement. All ratings for the ProxOps task were Level 1. These evaluations indicate that Orion is on course to meet NASA's handling quality requirements for ProxOps and docking.

  2. Cancer risk and residential proximity to cranberry cultivation in Massachusetts.

    PubMed Central

    Aschengrau, A; Ozonoff, D; Coogan, P; Vezina, R; Heeren, T; Zhang, Y

    1996-01-01

    OBJECTIVES: This study evaluated the relationship between cancer risk and residential proximity to cranberry cultivation. METHODS: A population-based case-control study was conducted. Cases, diagnosed during 1983 through 1986 among residents of the Upper Cape Cod area of Massachusetts, involved incident cancers of the lung (n = 252), breast (n = 265), colon-rectum (n = 326), bladder (n = 63), kidney (n = 35), pancreas (n = 37), and brain (n = 37), along with leukemia (n = 35). Control subjects were randomly selected from among telephone subscribers (n = 184), Medicare beneficiaries (n = 464), and deceased individuals (n = 723). RESULTS: No meaningful increases in risk were seen for any of the cancer sites except for the brain. When latency was considered, subjects who had ever lived within 2600 ft (780 m) of a cranberry bog had a twofold increased risk of brain cancer overall (95% confidence interval [CI] = 0.8, 4.9) and a 6.7-fold increased risk of astrocytoma (95% CI = 1.6, 27.8). CONCLUSIONS: Residential proximity to cranberry bog cultivation was not associated with seven of the eight cancers investigated; however, an association was observed with brain cancer, particularly astrocytoma. Larger, more detailed studies are necessary to elucidate this relationship. PMID:8806382

  3. Group Problem Solving as a Zone of Proximal Development activity

    NASA Astrophysics Data System (ADS)

    Brewe, Eric

    2006-12-01

    Vygotsky described learning as a process, intertwined with development, which is strongly influenced by social interactions with others that are at differing developmental stages.i These interactions create a Zone of Proximal Development for each member of the interaction. Vygotsky’s notion of social constructivism is not only a theory of learning, but also of development. While teaching introductory physics in an interactive format, I have found manifestations of Vygotsky’s theory in my classroom. The source of evidence is a paired problem solution. A standard mechanics problem was solved by students in two classes as a homework assignment. Students handed in the homework and then solved the same problem in small groups. The solutions to both the group and individual problem were assessed by multiple reviewers. In many cases the group score was the same as the highest individual score in the group, but in some cases, the group score was higher than any individual score. For this poster, I will analyze the individual and group scores and focus on three groups solutions and video that provide evidence of learning through membership in a Zone of Proximal Development. Endnotes i L. Vygotsky -Mind and society: The development of higher mental processes. Cambridge, MA: Harvard University Press. (1978).

  4. A positioned +1 nucleosome enhances promoter-proximal pausing

    PubMed Central

    Jimeno-González, Silvia; Ceballos-Chávez, María; Reyes, José C.

    2015-01-01

    Chromatin distribution is not uniform along the human genome. In most genes there is a promoter-associated nucleosome free region (NFR) followed by an array of nucleosomes towards the gene body in which the first (+1) nucleosome is strongly positioned. The function of this characteristic chromatin distribution in transcription is not fully understood. Here we show in vivo that the +1 nucleosome plays a role in modulating RNA polymerase II (RNAPII) promoter-proximal pausing. When a +1 nucleosome is strongly positioned, elongating RNAPII has a tendency to stall at the promoter-proximal region, recruits more negative elongation factor (NELF) and produces less mRNA. The nucleosome-induced pause favors pre-mRNA quality control by promoting the addition of the cap to the nascent RNA. Moreover, the uncapped RNAs produced in the absence of a positioned nucleosome are degraded by the 5′-3′ exonuclease XRN2. Interestingly, reducing the levels of the chromatin remodeler ISWI factor SNF2H decreases +1 nucleosome positioning and increases RNAPII pause release. This work demonstrates a function for +1 nucleosome in regulation of transcription elongation, pre-mRNA processing and gene expression. PMID:25735750

  5. Scaphoid Proximal Pole Fracture Following Headless Screw Fixation

    PubMed Central

    Rancy, Schneider K.; Zelken, Jonathan A.; Lipman, Joseph D.; Wolfe, Scott W.

    2015-01-01

    Background Headless screw fixation of scaphoid fractures and nonunions yields predictably excellent outcomes with a relatively low complication profile. However, intramedullary implants affect the load to failure and stress distribution within bone and may be implicated in subsequent fracture. Case Description We describe a posttraumatic fracture pattern of the scaphoid proximal pole originating at the previous headless screw insertion site in three young male patients with healed scaphoid nonunions. Each fracture was remarkably similar in shape and size, comprised the volar proximal pole, and was contiguous with the screw entry point. Treatment was challenging but successful in all cases. Literature Review Previous reports have posited that stress-raisers secondary to screw orientation may be implicated in subsequent peri-implant fracture of the femoral neck. Repeat scaphoid fracture after screw fixation has also been reported. However, the shape and locality of secondary fracture have not been described, nor has the potential role of screw fixation in the production of distinct fracture patterns. Clinical Relevance Hand surgeons must be aware of this difficult complication that may follow antegrade headless screw fixation of scaphoid fracture nonunion, and of available treatment strategies. PMID:26855840

  6. QCL-based standoff and proximal chemical detectors

    NASA Astrophysics Data System (ADS)

    Dupuis, Julia R.; Hensley, Joel; Cosofret, Bogdan R.; Konno, Daisei; Mulhall, Phillip; Schmit, Thomas; Chang, Shing; Allen, Mark; Marinelli, William J.

    2016-05-01

    The development of two longwave infrared quantum cascade laser (QCL) based surface contaminant detection platforms supporting government programs will be discussed. The detection platforms utilize reflectance spectroscopy with application to optically thick and thin materials including solid and liquid phase chemical warfare agents, toxic industrial chemicals and materials, and explosives. Operation at standoff (10s of m) and proximal (1 m) ranges will be reviewed with consideration given to the spectral signatures contained in the specular and diffusely reflected components of the signal. The platforms comprise two variants: Variant 1 employs a spectrally tunable QCL source with a broadband imaging detector, and Variant 2 employs an ensemble of broadband QCLs with a spectrally selective detector. Each variant employs a version of the Adaptive Cosine Estimator for detection and discrimination in high clutter environments. Detection limits of 5 μg/cm2 have been achieved through speckle reduction methods enabling detector noise limited performance. Design considerations for QCL-based standoff and proximal surface contaminant detectors are discussed with specific emphasis on speckle-mitigated and detector noise limited performance sufficient for accurate detection and discrimination regardless of the surface coverage morphology or underlying surface reflectivity. Prototype sensors and developmental test results will be reviewed for a range of application scenarios. Future development and transition plans for the QCL-based surface detector platforms are discussed.

  7. Uncertainty quantification for personalized analyses of human proximal femurs.

    PubMed

    Wille, Hagen; Ruess, Martin; Rank, Ernst; Yosibash, Zohar

    2016-02-29

    Computational models for the personalized analysis of human femurs contain uncertainties in bone material properties and loads, which affect the simulation results. To quantify the influence we developed a probabilistic framework based on polynomial chaos (PC) that propagates stochastic input variables through any computational model. We considered a stochastic E-ρ relationship and a stochastic hip contact force, representing realistic variability of experimental data. Their influence on the prediction of principal strains (ϵ1 and ϵ3) was quantified for one human proximal femur, including sensitivity and reliability analysis. Large variabilities in the principal strain predictions were found in the cortical shell of the femoral neck, with coefficients of variation of ≈40%. Between 60 and 80% of the variance in ϵ1 and ϵ3 are attributable to the uncertainty in the E-ρ relationship, while ≈10% are caused by the load magnitude and 5-30% by the load direction. Principal strain directions were unaffected by material and loading uncertainties. The antero-superior and medial inferior sides of the neck exhibited the largest probabilities for tensile and compression failure, however all were very small (pf<0.001). In summary, uncertainty quantification with PC has been demonstrated to efficiently and accurately describe the influence of very different stochastic inputs, which increases the credibility and explanatory power of personalized analyses of human proximal femurs.

  8. Designing and Applying Proximity-Dependent Hybridization Chain Reaction.

    PubMed

    Koos, Björn; Söderberg, Ola

    2016-08-01

    Proximity-dependent hybridization chain reaction (proxHCR) is a novel technique for detection of protein interaction, post-translational modifications (PTMs), or protein expression. The method is based upon antibodies targeting the proteins of interest that are covalently conjugated to DNA oligonucleotides, which enables the induction of a hybridization chain reaction (HCR) to generate a fluorescent signal visible under a microscope. In contrast to the in situ proximity ligation assay (in situ PLA), which is another method that utilizes antibody-DNA conjugates to detect protein interactions, proxHCR does not require enzymatic steps. This makes proxHCR an inexpensive alternative to in situ PLA. Another potential advantage might be that proxHCR could more readily be adapted for use in automated staining procedures and in point-of-care devices, as all reagents can be stored at room temperature. This unit describes how the oligonucleotide system for proxHCR can be designed and a protocol for how to perform proxHCR is presented. © 2016 by John Wiley & Sons, Inc.

  9. Proximal humeral replacement using a fixed-fulcrum endoprosthesis.

    PubMed

    Griffiths, D; Gikas, P D; Jowett, C; Bayliss, L; Aston, W; Skinner, J; Cannon, S; Blunn, G; Briggs, T W R; Pollock, R

    2011-03-01

    Between 1997 and 2007, 68 consecutive patients underwent replacement of the proximal humerus for tumour using a fixed-fulcrum massive endoprosthesis. Their mean age was 46 years (7 to 87). Ten patients were lost to follow-up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumor Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) at a mean follow-up of five years and 11 months (one year to ten years and nine months). The mean MSTS score was 72.3% (53.3% to 100%) and the mean TESS was 77.2% (58.6% to 100%). Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This subgroup had a mean MSTS score of 77.7% and a mean TESS of 80.0%. The dislocation rate for the original prosthesis was 25.9; none of the patients with the new liner had a dislocation at a mean of 14.5 months (12 to 18). Endoprosthetic replacement for tumours of the proximal humerus using this prosthesis is a reliable operation yielding good results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with a new constrained humeral liner, which reduces the risk of dislocation.

  10. The human NBCe1-A mutant R881C, associated with proximal renal tubular acidosis, retains function but is mistargeted in polarized renal epithelia.

    PubMed

    Toye, Ashley M; Parker, Mark D; Daly, Christopher M; Lu, Jing; Virkki, Leila V; Pelletier, Marc F; Boron, Walter F

    2006-10-01

    The human electrogenic renal Na-HCO(3) cotransporter (NBCe1-A; SLC4A4) is localized to the basolateral membrane of proximal tubule cells. Mutations in the SLC4A4 gene cause an autosomal recessive proximal renal tubular acidosis (pRTA), a disease characterized by impaired ability of the proximal tubule to reabsorb HCO(3)(-) from the glomerular filtrate. Other symptoms can include mental retardation and ocular abnormalities. Recently, a novel homozygous missense mutant (R881C) of NBCe1-A was reported from a patient with a severe pRTA phenotype. The mutant protein was described as having a lower than normal activity when expressed in Xenopus oocytes, despite having normal Na(+) affinity. However, without trafficking data, it is impossible to determine the molecular basis for the phenotype. In the present study, we expressed wild-type NBCe1-A (WT) and mutant NBCe1-A (R881C), tagged at the COOH terminus with enhanced green fluorescent protein (EGFP). This approach permitted semiquantification of surface expression in individual Xenopus oocytes before assay by two-electrode voltage clamp or measurements of intracellular pH. These data show that the mutation reduces the surface expression rather than the activity of the individual protein molecules. Confocal microscopy on polarized mammalian epithelial kidney cells [Madin-Darby canine kidney (MDCK)I] expressing nontagged WT or R881C demonstrates that WT is expressed at the basolateral membrane of these cells, whereas R881C is retained in the endoplasmic reticulum. In summary, the pathophysiology of pRTA caused by the R881C mutation is likely due to a deficit of NBCe1-A at the proximal tubule basolateral membrane, rather than a defect in the transport activity of individual molecules.

  11. Angiotensin II counteracts the effects of cAMP/PKA on NHE3 activity and phosphorylation in proximal tubule cells.

    PubMed

    Crajoinas, Renato O; Polidoro, Juliano Z; Carneiro de Morais, Carla P A; Castelo-Branco, Regiane C; Girardi, Adriana C C

    2016-11-01

    Binding of angiotensin II (ANG II) to the AT1 receptor (AT1R) in the proximal tubule stimulates Na(+)/H(+) exchanger isoform 3 (NHE3) activity through multiple signaling pathways. However, the effects of ANG II/AT1R-induced inihibitory G protein (Gi) activation and subsequent decrease in cAMP accumulation on NHE3 regulation are not well established. We therefore tested the hypothesis that ANG II reduces cAMP/PKA-mediated phosphorylation of NHE3 on serine 552 and, in doing so, stimulates NHE3 activity. Under basal conditions, ANG II stimulated NHE3 activity but did not affect PKA-mediated NHE3 phosphorylation at serine 552 in opossum kidney (OKP) cells. However, in the presence of the cAMP-elevating agent forskolin (FSK), ANG II blocked FSK-induced NHE3 inhibition, reduced intracellular cAMP concentrations, lowered PKA activity, and prevented the FSK-mediated increase in NHE3 serine 552 phosphorylation. All effects of ANG II were blocked by pretreating OKP cells with the AT1R antagonist losartan, highlighting the contribution of the AT1R/Gi pathway in ANG II-mediated NHE3 upregulation under cAMP-elevating conditions. Accordingly, Gi inhibition by pertussis toxin treatment decreased NHE3 activity both in vitro and in vivo and, more importantly, prevented the stimulatory effect of ANG II on NHE3 activity in rat proximal tubules. Collectively, our results suggest that ANG II counteracts the effects of cAMP/PKA on NHE3 phosphorylation and inhibition by activating the AT1R/Gi pathway. Moreover, these findings support the notion that NHE3 dephosphorylation at serine 552 may represent a key event in the regulation of renal proximal tubule sodium handling by ANG II in the presence of natriuretic hormones that promote cAMP accumulation and transporter phosphorylation.

  12. Childhood leukemia and residential proximity to industrial and urban sites

    SciTech Connect

    García-Pérez, Javier; López-Abente, Gonzalo; Gómez-Barroso, Diana; Morales-Piga, Antonio; Pardo Romaguera, Elena; Tamayo, Ibon; Fernández-Navarro, Pablo; and others

    2015-07-15

    Background: Few risk factors for the childhood leukemia are well established. While a small fraction of cases of childhood leukemia might be partially attributable to some diseases or ionizing radiation exposure, the role of industrial and urban pollution also needs to be assessed. Objectives: To ascertain the possible effect of residential proximity to both industrial and urban areas on childhood leukemia, taking into account industrial groups and toxic substances released. Methods: We conducted a population-based case–control study of childhood leukemia in Spain, covering 638 incident cases gathered from the Spanish Registry of Childhood Tumors and for those Autonomous Regions with 100% coverage (period 1990-2011), and 13,188 controls, individually matched by year of birth, sex, and autonomous region of residence. Distances were computed from the respective subject’s residences to the 1068 industries and the 157 urban areas with ≥10,000 inhabitants, located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to industrial and urban pollution sources were calculated, with adjustment for matching variables. Results: Excess risk of childhood leukemia was observed for children living near (≤2.5 km) industries (OR=1.31; 95%CI=1.03–1.67) – particularly glass and mineral fibers (OR=2.42; 95%CI=1.49–3.92), surface treatment using organic solvents (OR=1.87; 95%CI=1.24–2.83), galvanization (OR=1.86; 95%CI=1.07–3.21), production and processing of metals (OR=1.69; 95%CI=1.22–2.34), and surface treatment of metals (OR=1.62; 95%CI=1.22–2.15) – , and urban areas (OR=1.36; 95%CI=1.02–1.80). Conclusions: Our study furnishes some evidence that living in the proximity of industrial and urban sites may be a risk factor for childhood leukemia. - Highlights: • We studied proximity to both industrial and urban sites on childhood leukemia. • We conducted a case–control study in

  13. Proteomic profiling of the effect of metabolic acidosis on the apical membrane of the proximal convoluted tubule

    PubMed Central

    Walmsley, Scott J.; Freund, Dana M.

    2012-01-01

    The physiological response to the onset of metabolic acidosis requires pronounced changes in renal gene expression. Adaptations within the proximal convoluted tubule support the increased extraction of plasma glutamine and the increased synthesis and transport of glucose and of NH4+ and HCO3− ions. Many of these adaptations involve proteins associated with the apical membrane. To quantify the temporal changes in these proteins, proteomic profiling was performed using brush-border membrane vesicles isolated from proximal convoluted tubules (BBMVPCT) that were purified from normal and acidotic rats. This preparation is essentially free of contaminating apical membranes from other renal cortical cells. The analysis identified 298 proteins, 26% of which contained one or more transmembrane domains. Spectral counts were used to assess changes in protein abundance. The onset of acidosis produced a twofold, but transient, increase in the Na+-dependent glucose transporter and a more gradual, but sustained, increase (3-fold) in the Na+-dependent lactate transporter. These changes were associated with the loss of glycolytic and gluconeogenic enzymes that are contained in the BBMVPCT isolated from normal rats. In addition, the levels of γ-glutamyltranspeptidase increased twofold, while transporters that participate in the uptake of neutral amino acids, including glutamine, were decreased. These changes could facilitate the deamidation of glutamine within the tubular lumen. Finally, pronounced increases were also observed in the levels of DAB2 (3-fold) and myosin 9 (7-fold), proteins that may participate in endocytosis of apical membrane proteins. Western blot analysis and accurate mass and time analyses were used to validate the spectral counting. PMID:22357915

  14. Mass inversion in graphene by proximity to dichalcogenide monolayer

    NASA Astrophysics Data System (ADS)

    Alsharari, Abdulrhman M.; Asmar, Mahmoud M.; Ulloa, Sergio E.

    2016-12-01

    Proximity effects resulting from depositing a graphene layer on a transition-metal dichalcogenide substrate layer change the dynamics of the electronic states in graphene, inducing spin-orbit coupling and staggered potential effects. An effective Hamiltonian that describes different symmetry-breaking terms in graphene, while preserving time-reversal invariance, shows that an inverted mass band-gap regime is possible. The competition of different perturbation terms causes a transition from an inverted mass phase to a staggered gap in the bilayer heterostructure as seen in its phase diagram. A tight-binding calculation of the bilayer validates the effective model parameters. A relative gate voltage between the layers may produce such a phase transition in experimentally accessible systems. The phases are characterized in terms of Berry curvature and valley Chern numbers, demonstrating that the system may exhibit quantum spin Hall and valley Hall effects.

  15. Residential Proximity to Environmental Hazards and Adverse Health Outcomes

    PubMed Central

    Maantay, Juliana A.; Chakraborty, Jayajit

    2011-01-01

    How living near environmental hazards contributes to poorer health and disproportionate health outcomes is an ongoing concern. We conducted a substantive review and critique of the literature regarding residential proximity to environmental hazards and adverse pregnancy outcomes, childhood cancer, cardiovascular and respiratory illnesses, end-stage renal disease, and diabetes. Several studies have found that living near hazardous wastes sites, industrial sites, cropland with pesticide applications, highly trafficked roads, nuclear power plants, and gas stations or repair shops is related to an increased risk of adverse health outcomes. Government agencies should consider these findings in establishing rules and permitting and enforcement procedures to reduce pollution from environmentally burdensome facilities and land uses. PMID:22028451

  16. Variable reluctance proximity sensors for cryogenic valve position indication

    NASA Technical Reports Server (NTRS)

    Cloyd, R. A.

    1982-01-01

    A test was conducted to determine the performance of a variable reluctance proximity sensor system when installed in a space shuttle external tank vent/relief valve. The sensors were used as position indicators. The valve and sensors were cycled through a series of thermal transients; while the valve was being opened and closed pneumatically, the sensor's performance was being monitored. During these thermal transients, the vent valve was cooled ten times by liquid nitrogen and two times by liquid hydrogen. It was concluded that the sensors were acceptable replacements for the existing mechanical switches. However, the sensors need a mechanical override for the target similar to what is presently used with the mechanical switches. This override could insure contact between sensor and target and eliminate any problems of actuation gap growth caused by thermal gradients.

  17. Analytic-domain lens design with proximate ray tracing.

    PubMed

    Zheng, Nan; Hagen, Nathan; Brady, David J

    2010-08-01

    We have developed an alternative approach to optical design which operates in the analytical domain so that an optical designer works directly with rays as analytical functions of system parameters rather than as discretely sampled polylines. This is made possible by a generalization of the proximate ray tracing technique which obtains the analytical dependence of the rays at the image surface (and ray path lengths at the exit pupil) on each system parameter. The resulting method provides an alternative direction from which to approach system optimization and supplies information which is not typically available to the system designer. In addition, we have further expanded the procedure to allow asymmetric systems and arbitrary order of approximation, and have illustrated the performance of the method through three lens design examples.

  18. Sensitive detection of aggregated prion protein via proximity ligation

    PubMed Central

    Hammond, Maria; Wik, Lotta; Deslys, Jean-Philippe; Comoy, Emmanuel; Linné, Tommy; Landegren, Ulf; Kamali-Moghaddam, Masood

    2014-01-01

    The DNA assisted solid-phase proximity ligation assay (SP-PLA) provides a unique opportunity to specifically detect prion protein (PrP) aggregates by investigating the collocation of 3 or more copies of the specific protein. We have developed an SP-PLA that can detect PrP aggregates in brain homogenates from infected hamsters even after a 107-fold dilution. In contrast, brain homogenate from uninfected animals did not generate a detectable signal at 100-fold higher concentration. Using either of the 2 monoclonal anti-PrP antibodies, 3F4 and 6H4, we successfully detected low concentrations of aggregated PrP. The presented results provide a proof of concept that this method might be an interesting tool in the development of diagnostic approaches of prion diseases. PMID:25482604

  19. Intraoperative Proximal Femoral Fracture in Primary Cementless Total Hip Arthroplasty.

    PubMed

    Ponzio, Danielle Y; Shahi, Alisina; Park, Andrew G; Purtill, James J

    2015-08-01

    Intraoperative proximal femoral fracture is a complication of primary cementless total hip arthroplasty (THA) at rates of 2.95-27.8%. A retrospective review of 2423 consecutive primary cementless THA cases identified 102 hips (96 patients) with fracture. Multivariate analysis compared fracture incidences between implants, Accolade (Stryker Orthopaedics) and Tri-Lock (DePuy Orthopaedics, Inc.), and evaluated potential risk factors using a randomized control group of 1150 cases without fracture. The fracture incidence was 4.4% (102/2423), 3.7% (36/1019) using Accolade and 4.9% using Tri-Lock (66/1404) (P=0.18). Female gender (OR=1.96; 95% CI 1.19-3.23; P=0.008) and smaller stem size (OR=1.64; 95% CI 1.04-2.63; P=0.03) predicted increased odds of fracture. No revisions of the femoral component were required in the fracture cohort.

  20. Sensitive detection of aggregated prion protein via proximity ligation.

    PubMed

    Hammond, Maria; Wik, Lotta; Deslys, Jean-Philippe; Comoy, Emmanuel; Linné, Tommy; Landegren, Ulf; Kamali-Moghaddam, Masood

    2014-01-01

    The DNA assisted solid-phase proximity ligation assay (SP-PLA) provides a unique opportunity to specifically detect prion protein (PrP) aggregates by investigating the collocation of 3 or more copies of the specific protein. We have developed an SP-PLA that can detect PrP aggregates in brain homogenates from infected hamsters even after a 10(7)-fold dilution. In contrast, brain homogenate from uninfected animals did not generate a detectable signal at 100-fold higher concentration. Using either of the 2 monoclonal anti-PrP antibodies, 3F4 and 6H4, we successfully detected low concentrations of aggregated PrP. The presented results provide a proof of concept that this method might be an interesting tool in the development of diagnostic approaches of prion diseases.

  1. Proximal and point detection of contaminated surfaces using Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Guicheteau, Jason A.; Christesen, Steven D.; Tripathi, Ashish; Emmons, Erik D.; Wilcox, Phillip G.; Emge, Darren K.; Pardoe, Ian J.; Fountain, Augustus W., III

    2011-11-01

    We are actively investigating the use of Raman spectroscopy for proximal standoff detection of chemicals and explosive materials on surfaces. These studies include Raman Chemical Imaging of contaminated fingerprints for forensic attribution and the assessments of commercial handheld or portable Raman instruments operating with near-infrared (IR) as well as ultraviolet (UV) laser excitation specifically developed for on-the-move reconnaissance of chemical contamination. As part of these efforts, we have measured the Raman cross sections of chemical agents, toxic industrial chemicals, and explosives from the UV to NIR. We have also measured and modeled the effect interrogation angle has on the Raman return from droplets on man-made surfaces. Realistic droplet distributions have been modeled and tested against variations in surface scan patterns and laser spot size for determining the optimum scan characteristics for detection of relevant surface contamination.

  2. Detection of Protein SUMOylation In Situ by Proximity Ligation Assays.

    PubMed

    Sahin, Umut; Jollivet, Florence; Berthier, Caroline; de Thé, Hugues; Lallemand-Breitenbach, Valérie

    2016-01-01

    Sumoylation is a posttranslational process essential for life and concerns a growing number of crucial proteins. Understanding the influence of this phenomenon on individual proteins or on cellular pathways in which they function has become an intense area of research. A critical step in studying protein sumoylation is to detect sumoylated forms of a particular protein. This has proven to be a challenging task for a number of reasons, especially in the case of endogenous proteins and in vivo studies or when studying rare cells such as stem cells. Proximity ligation assays that allow detection of closely interacting protein partners can be adapted for initial detection of endogenous sumoylation or ubiquitination in a rapid, ultrasensitive, and cheap manner. In addition, modified forms of a given protein can be detected in situ in various cellular compartments. Finally, the flexibility of this technique may allow rapid screening of drugs and stress signals that may modulate protein sumoylation.

  3. Endovascular treatment of proximal arsastomotic aneurysms after aortic prosthetic reconstruction

    SciTech Connect

    Tiesenhausen, Kurt; Hausegger, Klaus A.; Tauss, Josef; Amann, Wilfried; Koch, Guenter

    2001-01-15

    Purpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudo-aneurysms.Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8-15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n=1), bifurcated graft (n=s1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.

  4. Endovascular Treatment of Proximal Anastomotic Aneurysms After Aortic Prosthetic Reconstruction

    SciTech Connect

    Tiesenhausen, Kurt; Hausegger, Klaus A.; Tauss, Josef; Amann, Wilfried; Koch, Guenter

    2001-01-15

    Purpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudoaneurysms.Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8-15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n = 1), bifurcated graft (n = 1)]. In one patient an uni iliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.

  5. Factors affecting minority population proximity to hazardous facilities

    SciTech Connect

    Nieves, L.A.; Nieves, A.L. |

    1995-04-01

    Disproportionate exposure of minority groups to environmental hazards has been attributed to ``environmental racism`` by some authors, without systematic investigation of the factors underlying this exposure pattern. This study examines regional differences in the proximity of African-Americans, Hispanics, Asians, and non-Hispanic Whites to a broad range of facility types and explores the effects of urban and income factors. A statistically significant inverse relationship is found between the percentage of non-Hispanic Whites and virtually all facility categories in all regions. Except for Hispanics in the South, all such associations for minority groups show a direct relationship, though some are nonsignificant. The geographic concentration of facilities is more closely tied to urbanization than to economic factors. Controlling for both urban and economic factors, minority population concentration is still a significant explanatory variable for some facility types in some regions. This finding is most consistent for African-Americans.

  6. Fundamental Proximity Effects in Focused electron Beam Induced Deposition

    SciTech Connect

    Plank, Harald; Smith, Daryl; Haber, Thomas; Rack, Philip D; Hofer, Ferdinand

    2012-01-01

    Fundamental proximity effects for electron beam induced deposition processes on nonflat surfaces were studied experimentally and via simulation. Two specific effects were elucidated and exploited to considerably increase the volumetric growth rate of this nanoscale direct write method: (1) increasing the scanning electron pitch to the scale of the lateral electron straggle increased the volumetric growth rate by 250% by enhancing the effective forward scattered, backscattered, and secondary electron coefficients as well as by strong recollection effects of adjacent features; and (2) strategic patterning sequences are introduced to reduce precursor depletion effects which increase volumetric growth rates by more than 90%, demonstrating the strong influence of patterning parameters on the final performance of this powerful direct write technique.

  7. Proximity fingerprint of s{plus_minus} superconductivity.

    SciTech Connect

    Koshelev, A. E.; Stanev, V.

    2011-01-01

    We suggest a straightforward and unambiguous test to identify possible opposite signs of the superconducting order parameter in different bands proposed for iron-based superconductors (s{sub {+-}}-state). We consider the proximity effect in a weakly coupled sandwich composed of a s{sub {+-}}-superconductor and a thin layer of the s-wave superconductor. In such system the s-wave order parameter is coupled differently with different s{sub {+-}}-gaps and it typically aligns with one of these gaps. This forces the other s{sub {+-}}-gap to be anti-aligned with the s-wave gap. In such situation the aligned band induces a peak in the s-wave density of states (DoS), while the anti-aligned band induces a dip. Observation of such contact-induced negative feature in the s-wave DoS would provide a definite proof for s{sub {+-}}-superconductivity.

  8. Implicit learning of arithmetic regularities is facilitated by proximal contrast.

    PubMed

    Prather, Richard W

    2012-01-01

    Natural number arithmetic is a simple, powerful and important symbolic system. Despite intense focus on learning in cognitive development and educational research many adults have weak knowledge of the system. In current study participants learn arithmetic principles via an implicit learning paradigm. Participants learn not by solving arithmetic equations, but through viewing and evaluating example equations, similar to the implicit learning of artificial grammars. We expand this to the symbolic arithmetic system. Specifically we find that exposure to principle-inconsistent examples facilitates the acquisition of arithmetic principle knowledge if the equations are presented to the learning in a temporally proximate fashion. The results expand on research of the implicit learning of regularities and suggest that contrasting cases, show to facilitate explicit arithmetic learning, is also relevant to implicit learning of arithmetic.

  9. Orion Rendezvous, Proximity Operations, and Docking Design and Analysis

    NASA Technical Reports Server (NTRS)

    D'Souza, Christopher; Hanak, F. Chad; Spehar, Pete; Clark, Fred D.; Jackson, Mark

    2007-01-01

    The Orion vehicle will be required to perform rendezvous, proximity operations, and docking with the International Space Station (ISS) and the Earth Departure Stage (EDS)/Lunar Landing Vehicle (LLV) stack in Low Earth Orbit (LEO) as well as with the Lunar Landing Vehicle in Low Lunar Orbit (LLO). The RPOD system, which consists of sensors, actuators, and software is being designed to be flexible and robust enough to perform RPOD with different vehicles in different environments. This paper will describe the design and the analysis which has been performed to date to allow the vehicle to perform its mission. Since the RPOD design touches on many areas such as sensors selection and placement, trajectory design, navigation performance, and effector performance, it is inherently a systems design problem. This paper will address each of these issues in order to demonstrate how the Orion RPOD has been designed to accommodate and meet all the requirements levied on the system.

  10. Magnetic proximity effect in perovskite superconductor/ferromagnet multilayers

    NASA Astrophysics Data System (ADS)

    Stahn, J.; Chakhalian, J.; Niedermayer, Ch.; Hoppler, J.; Gutberlet, T.; Voigt, J.; Treubel, F.; Habermeier, H.-U.; Cristiani, G.; Keimer, B.; Bernhard, C.

    2005-04-01

    Multilayers of superconducting/ferromagnetic (SC/FM) YBa2Cu3O7/La2/3Ca1/3MnO3 have been studied by neutron reflectometry. The occurrence of a structurally forbidden Bragg peak in the FM state highlights a significant difference between the nuclear and magnetic depth profiles. From comparison with simulated reflectivity curves we identify two possible magnetization profiles: (i) a magnetic moment within the SC layer antiparallel to the one in the FM layer (antiphase magnetic proximity effect) or (ii) a “dead” region in the FM layer with zero net magnetic moment. In addition, we observe an anomalous enhancement of the off-specular reflection in the SC state which signals a strong mutual interaction between SC and FM order parameters.

  11. Rendezvous, proximity operations and capture quality function deployment report

    NASA Astrophysics Data System (ADS)

    Lamkin, Stephen L.

    1991-12-01

    Rendezvous, Proximity Operations, and Capture (RPOC) is a missions operations area which is extremely important to present and future space initiatives and must be well planned and coordinated. To support this, a study team was formed to identify a specific plan of action using the Quality Function Deployment (QFD) process. This team was composed of members from a wide spectrum of engineering and operations organizations which are involved in the RPOC technology area. The key to this study's success is an understanding of the needs of potential programmatic customers and the technology base available for system implementation. To this end, the study team conducted interviews with a variety of near term and future programmatic customers and technology development sponsors. The QFD activity led to a thorough understanding of the needs of these customers in the RPOC area, as well as the relative importance of these needs.

  12. Studying Cerebral Vasculature Using Structure Proximity and Graph Kernels

    PubMed Central

    Kwitt, Roland; Pace, Danielle; Niethammer, Marc; Aylward, Stephen

    2014-01-01

    An approach to study population differences in cerebral vasculature is proposed. This is done by 1) extending the concept of encoding cerebral blood vessel networks as spatial graphs and 2) quantifying graph similarity in a kernel-based discriminant classifier setup. We argue that augmenting graph vertices with information about their proximity to selected brain structures adds discriminative information and consequently leads to a more expressive encoding. Using graph-kernels then allows us to quantify graph similarity in a principled way. To demonstrate our approach, we assess the hypothesis that gender differences manifest as variations in the architecture of cerebral blood vessels, an observation that previously had only been tested and confirmed for the Circle of Willis. Our results strongly support this hypothesis, i.e, we can demonstrate non-trivial, statistically significant deviations from random gender classification in a cross-validation setup on 40 healthy patients. PMID:24579182

  13. Solute-Solvent Energetics Based on Proximal Distribution Functions.

    PubMed

    Ou, Shu-Ching; Pettitt, B Montgomery

    2016-08-25

    We consider the hydration structure and thermodynamic energetics of solutes in aqueous solution. On the basis of the dominant local correlation between the solvent and the chemical nature of the solute atoms, proximal distribution functions (pDF) can be used to quantitatively estimate the hydration pattern of the macromolecules. We extended this technique to study the solute-solvent energetics including the van der Waals terms representing excluded volume and tested the method with butane and propanol. Our results indicate that the pDF-reconstruction algorithm can reproduce van der Waals solute-solvent interaction energies to useful kilocalorie per mole accuracy. We subsequently computed polyalanine-water interaction energies for a variety of conformers, which also showed agreement with the simulated values.

  14. Extracorporeal shockwave therapy for chronic proximal plantar fasciitis.

    PubMed

    Strash, Walter W; Perez, Richard R

    2002-10-01

    Although much enthusiasm surrounds applying extracorporeal shock wave therapy for various musculoskeletal conditions, its effects are not well understood and warrant continued study. Certain body tissues or organs may be damaged either acutely or chronically by ESWT; however, it is unequivocal that lung tissue may be damaged. It is theorized that neovascularization is responsible for improvement in symptoms of plantar fasciitis. Neovascularization is the direct effect of macrophage stimulation through cytokines. ESWT has effects at the cellular level--does it interfere with metabolic activity or enhance it? The noninvasive nature and minimal complications of appropriately applied ESWT are its primary advantages. Symptoms may continue to improve for three weeks to six months after treatment; the effects of shock wave therapy seem to be time dependent. ESWT is an effective form of treatment for proximal insertional plantar fasciitis after exhaustive, conservative forms of treatment have failed.

  15. Rendezvous, proximity operations and capture quality function deployment report

    NASA Technical Reports Server (NTRS)

    Lamkin, Stephen L. (Editor)

    1991-01-01

    Rendezvous, Proximity Operations, and Capture (RPOC) is a missions operations area which is extremely important to present and future space initiatives and must be well planned and coordinated. To support this, a study team was formed to identify a specific plan of action using the Quality Function Deployment (QFD) process. This team was composed of members from a wide spectrum of engineering and operations organizations which are involved in the RPOC technology area. The key to this study's success is an understanding of the needs of potential programmatic customers and the technology base available for system implementation. To this end, the study team conducted interviews with a variety of near term and future programmatic customers and technology development sponsors. The QFD activity led to a thorough understanding of the needs of these customers in the RPOC area, as well as the relative importance of these needs.

  16. [Apophyseal avulsions of the pelvis and proximal femur].

    PubMed

    Jacobsen, S

    1993-07-05

    Avulsion fractures of the pelvic and proximal femoral apophyseal centres are not uncommonly seen in adolescent athletes engaged in vigorous sports. They are the result of strong or uncoordinated muscular traction, and are the equivalents of muscle or tendon pulls in mature athletes. They are particularly seen in athletics, soccer, rugby, ice hockey and break dance. They involve the anterior third of the iliac crest, the anterior iliac spines, the tuber ischiadicum, the symphysis pubis and the trochanter minor. The radiographic and clinical diagnosis, symptoms and signs, treatment and prognosis are well described in the orthopaedic literature and this literature is evaluated here. The fractures are easily and almost exclusively treated conservatively, and will only in a few cases result in a lasting functional disability.

  17. Induced gap in topological materials from the superconducting proximity effect

    NASA Astrophysics Data System (ADS)

    Chiu, Ching-Kai; Cole, William

    Topological superconductivity has been of considerable interest lately, with several proposed experimental realizations in solid state systems. A heterostructure of s-wave superconductor and 3D topological insulator is one of the more promising platforms, with topological superconductivity realized on the ''naked'' surface of the topological insulator through the superconducting proximity effect. We theoretically study the induced superconducting gap on the naked surface. Adjusting the Fermi level above the bulk gap (which is the case in experiments), our results for the induced superconducting gap are in agreement with that probed in thin topological insulators (<10nm) in the experiments (Nat. Phys. 10, 943-950 (2014) and Phys. Rev. Lett. 112, 217001 (2014)). We further predict the gap in thick topological insulators (>10nm). This work is supported by LPS-MPO-CMTC, Microsoft Q, and JQI-NSF-PFC.

  18. Proximal Tubule Cell Hypothesis for Cardiorenal Syndrome in Diabetes

    PubMed Central

    Saito, Akihiko; Kaseda, Ryohei; Hosojima, Michihiro; Sato, Hiroyoshi

    2011-01-01

    Incidence of cardiovascular disease (CVD) is remarkably high among patients with chronic kidney disease (CKD), even in the early microalbuminuric stages with normal glomerular filtration rates. Proximal tubule cells (PTCs) mediate metabolism and urinary excretion of vasculotoxic substances via apical and basolateral receptors and transporters. These cells also retrieve vasculoprotective substances from circulation or synthesize them for release into the circulation. PTCs are also involved in the uptake of sodium and phosphate, which are critical for hemodynamic regulation and maintaining the mineral balance, respectively. Dysregulation of PTC functions in CKD is likely to be associated with the development of CVD and is linked to the progression to end-stage renal disease. In particular, PTC dysfunction occurs early in diabetic nephropathy, a leading cause of CKD. It is therefore important to elucidate the mechanisms of PTC dysfunction to develop therapeutic strategies for treating cardiorenal syndrome in diabetes. PMID:21197105

  19. Transition Metal Dichalcogenide Growth via Close Proximity Precursor Supply

    PubMed Central

    O'Brien, Maria; McEvoy, Niall; Hallam, Toby; Kim, Hye-Young; Berner, Nina C.; Hanlon, Damien; Lee, Kangho; Coleman, Jonathan N.; Duesberg, Georg S.

    2014-01-01

    Reliable chemical vapour deposition (CVD) of transition metal dichalcogenides (TMDs) is currently a highly pressing research field, as numerous potential applications rely on the production of high quality films on a macroscopic scale. Here, we show the use of liquid phase exfoliated nanosheets and patterned sputter deposited layers as solid precursors for chemical vapour deposition. TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup. A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented. Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, scanning electron microscopy and electrical transport measurements reveal the high quality of the TMD samples produced. Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components. PMID:25487822

  20. Granger causality stock market networks: Temporal proximity and preferential attachment

    NASA Astrophysics Data System (ADS)

    Výrost, Tomáš; Lyócsa, Štefan; Baumöhl, Eduard

    2015-06-01

    The structure of return spillovers is examined by constructing Granger causality networks using daily closing prices of 20 developed markets from 2nd January 2006 to 31st December 2013. The data is properly aligned to take into account non-synchronous trading effects. The study of the resulting networks of over 94 sub-samples revealed three significant findings. First, after the recent financial crisis the impact of the US stock market has declined. Second, spatial probit models confirmed the role of the temporal proximity between market closing times for return spillovers, i.e. the time distance between national stock markets matters. Third, a preferential attachment between stock markets exists, i.e. the probability of the presence of spillover effects between any given two markets increases with their degree of connectedness to others.

  1. Automobile proximity and indoor residential concentrations of BTEX and MTBE

    SciTech Connect

    Corsi, Dr. Richard; Morandi, Dr. Maria; Siegel, Dr. Jeffrey; Hun, Diana E

    2011-01-01

    Attached garages have been identified as important sources of indoor residential air pollution. However, the literature lacks information on how the proximity of cars to the living area affects indoor concentrations of gasoline-related compounds, and the origin of these pollutants. We analyzed data from the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study and evaluated 114 residences with cars in an attached garage, detached garage or carport, or without cars. Results indicate that homes with cars in attached garages were affected the most. Concentrations in homes with cars in detached garages and residences without cars were similar. The contribution from gasoline-related sources to indoor benzene and MTBE concentrations appeared to be dominated by car exhaust, or a combination of tailpipe and gasoline vapor emissions. Residing in a home with an attached garage could lead to benzene exposures ten times higher than exposures from commuting in heavy traffic.

  2. Probing dynamic protein ensembles with atomic proximity measures.

    PubMed

    Gáspári, Zoltán; Angyán, Annamária F; Dhir, Somdutta; Franklin, Dino; Perczel, András; Pintar, Alessandro; Pongor, Sándor

    2010-11-01

    The emerging role of internal dynamics in protein fold and function requires new avenues of structure analysis. We analyzed the dynamically restrained conformational ensemble of ubiquitin generated from residual dipolar coupling data, in terms of protruding and buried atoms as well as interatomic distances, using four proximity-based algorithms, CX, DPX, PRIDE and PRIDE-NMR (http://hydra.icgeb.trieste.it/protein/). We found that Ubiquitin, this relatively rigid molecule has a highly diverse dynamic ensemble. The environment of protruding atoms is highly variable across conformers, on the other hand, only a part of buried atoms tends to fluctuate. The variability of the ensemble cautions against the use of single conformers when explaining functional phenomena. We also give a detailed evaluation of PRIDE-NMR on a wide dataset and discuss its usage in the light of the features of available NMR distance restraint sets in public databases.

  3. Etch modeling for accurate full-chip process proximity correction

    NASA Astrophysics Data System (ADS)

    Beale, Daniel F.; Shiely, James P.

    2005-05-01

    The challenges of the 65 nm node and beyond require new formulations of the compact convolution models used in OPC. In addition to simulating more optical and resist effects, these models must accommodate pattern distortions due to etch which can no longer be treated as small perturbations on photo-lithographic effects. (Methods for combining optical and process modules while optimizing the speed/accuracy tradeoff were described in "Advanced Model Formulations for Optical and Process Proximity Correction", D. Beale et al, SPIE 2004.) In this paper, we evaluate new physics-based etch model formulations that differ from the convolution-based process models used previously. The new models are expressed within the compact modeling framework described by J. Stirniman et al. in SPIE, vol. 3051, p469, 1997, and thus can be used for high-speed process simulation during full-chip OPC.

  4. Determination of muscle effort at the proximal femur rotation osteotomy

    NASA Astrophysics Data System (ADS)

    Sachenkov, O.; Hasanov, R.; Andreev, P.; Konoplev, Yu

    2016-11-01

    The paper formulates the problem of biomechanics of a new method for treatment of Legg-Calve-Perthes disease. Numerical calculations of the rotational flexion osteotomy have been carried out for a constructed mathematical model of the hip joint, taking into account the main set of muscles. The work presents the results of the calculations and their analysis. The results have been compared with the clinical data. The calculations of the reactive forces arising in the acetabulum and the proximal part of the femur allowed us to reveal that this reactive force changes both in value and direction. These data may be useful for assessing the stiffness of an external fixation device used in orthopedic intervention and for evaluating the compression in the joint.

  5. Meniscal Allograft Interposition Combined with Proximal Row Carpectomy.

    PubMed

    Steiner, Murphy M; Willsey, Matthew R; Werner, Frederick W; Harley, Brian J; Klein, Shay; Setter, Kevin J

    2017-02-01

    Background Proximal row carpectomy (PRC) is contraindicated in wrists with preexisting arthritis of the proximal capitate or radiolunate fossa. Patients with these conditions frequently pursue wrist arthrodesis with its associated functional limitations. Questions/Purposes The purpose of this study was to evaluate the results of using lateral meniscal allograft interposition (LMAI), in combination with PRC, in patients with symptomatic wrist arthritis. The primary question is whether this allograft will allow wrist function comparable to that in patients having only a PRC. A secondary question was to determine the short-term longevity of the allograft. Patients/Method Between 2006 and 2012, nine wrists underwent PRC with LMAI. Patient demographics and rates of complication or graft failure were determined. During independent clinical exams, functional outcomes were reviewed, patients completed a Disabilities of the Arm, Shoulder, and Hand (DASH) scores, and radiographs were taken. Results Four patients met the inclusion criteria, having clinical follow-up at an average of 4.2 years. DASH scores at the time of follow-up ranged from 9 to 33, with an average of 24. Average radiocapitate joint space in the first postoperative radiograph was 2.8 mm compared with 1.8 mm at the time of final follow-up. No wrists went on to arthrodesis. Conclusion Early outcomes of PRC with LMAI are comparable to those results found in the literature of PRC alone. LMAI with PRC may be a valid short-term option as a motion-preserving procedure in those patients contraindicated to having a PRC alone. Level of Evidence Level IV.

  6. Proximity Labeling Reveals Molecular Determinants of FGFR4 Endosomal Transport.

    PubMed

    Haugsten, Ellen Margrethe; Sørensen, Vigdis; Kunova Bosakova, Michaela; de Souza, Gustavo Antonio; Krejci, Pavel; Wiedlocha, Antoni; Wesche, Jørgen

    2016-10-07

    The fibroblast growth factor receptors (FGFRs) are important oncogenes promoting tumor progression in many types of cancer, such as breast, bladder, and lung cancer as well as multiple myeloma and rhabdomyosarcoma. However, little is known about how these receptors are internalized and down-regulated in cells. We have here applied proximity biotin labeling to identify proteins involved in FGFR4 signaling and trafficking. For this purpose we fused a mutated biotin ligase, BirA*, to the C-terminal tail of FGFR4 (FGFR4-BirA*) and the fusion protein was stably expressed in U2OS cells. Upon addition of biotin to these cells, proteins in proximity to the FGFR4-BirA* fusion protein became biotinylated and could be isolated and identified by quantitative mass spectrometry. We identified in total 291 proteins, including 80 proteins that were enriched in samples where the receptor was activated by the ligand (FGF1), among them several proteins previously found to be involved in FGFR signaling (e.g., FRS2, PLCγ, RSK2 and NCK2). Interestingly, many of the identified proteins were implicated in endosomal transport, and by precise annotation we were able to trace the intracellular pathways of activated FGFR4. Validating the data by confocal and three-dimensional structured illumination microscopy analysis, we concluded that FGFR4 uses clathrin-mediated endocytosis for internalization and is further sorted from early endosomes to the recycling compartment and the trans-Golgi network. Depletion of cells for clathrin heavy chain led to accumulation of FGFR4 at the cell surface and increased levels of active FGFR4 and PLCγ, while AKT and ERK signaling was diminished, demonstrating that functional clathrin-mediated endocytosis is required for proper FGFR4 signaling. Thus, this study reveals proteins and pathways involved in FGFR4 transport and signaling that provide possible targets and opportunities for therapeutic intervention in FGFR4 aberrant cancer.

  7. Phase holograms in PMMA with proximity effect correction

    NASA Technical Reports Server (NTRS)

    Maker, Paul D.; Muller, R. E.

    1993-01-01

    Complex computer generated phase holograms (CGPH's) have been fabricated in PMMA by partial e-beam exposure and subsequent partial development. The CGPH was encoded as a sequence of phase delay pixels and written by the JEOL JBX-5D2 E-beam lithography system, a different dose being assigned to each value of phase delay. Following carefully controlled partial development, the pattern appeared rendered in relief in the PMMA, which then acts as the phase-delay medium. The exposure dose was in the range 20-200 micro-C/sq cm, and very aggressive development in pure acetone led to low contrast. This enabled etch depth control to better than plus or minus lambda(sub vis)/60. That result was obtained by exposing isolated 50 micron square patches and measuring resist removal over the central area where the proximity effect dose was uniform and related only to the local exposure. For complex CGPH's with pixel size of the order of the e-beam proximity effect radius, the patterns must be corrected for the extra exposure caused by electrons scattered back up out of the substrate. This has been accomplished by deconvolving the two-dimensional dose deposition function with the desired dose pattern. The deposition function, which plays much the same role as an instrument response function, was carefully measured under the exact conditions used to expose the samples. The devices fabricated were designed with 16 equal phase steps per retardation cycle, were up to 1 cm square, and consisted of up to 100 million 0.3-2.0 micron square pixels. Data files were up to 500 MB long and exposure times ranged to tens of hours. A Fresnel phase lens was fabricated that had diffraction limited optical performance with better than 85 percent efficiency.

  8. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

    PubMed

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (pH 6.9 v 6.8; p > 0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mumol/h; p < 0.02) and vagally stimulated (834 (72) v 474 (66) mumol/h; p < 0.02), but not acid stimulated (3351 (678) v 2550 (456) mumol/h; p > 0.05) duodenal bicarbonate secretion compared with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid inhibition. These results show that the proton pump inhibitor, omeprazole, promotes proximal duodenal mucosal bicarbonate secretion apparently independent of its gastric acid inhibitory effect. The mechanism of action remains speculative.

  9. Shock wave therapy for chronic proximal plantar fasciitis.

    PubMed

    Ogden, J A; Alvarez, R; Levitt, R; Cross, G L; Marlow, M

    2001-06-01

    Three hundred two patients with chronic heel pain caused by proximal plantar fasciitis were enrolled in a study to assess the treatment effects consequent to administration of electrohydraulicall-generated extracorporeal shock waves. Symptoms had been present from 6 months to 18 years. Each treated patient satisfied numerous inclusion and exclusion criteria before he or she was accepted into this study, which was approved by the Food and Drug Administration as a randomized, double-blind evaluation of the efficacy of shock wave therapy for this disorder. Overall, at the predetermined evaluation period 3 months after one treatment, 56% more of the treated patients had a successful result by all four of the evaluation criteria when compared with the patients treated with a placebo. This difference was significant and corroborated the fact that this difference in the results was specifically attributable to the shock wave treatment, rather than any natural improvement caused by the natural history of the condition. The current study showed that the directed application of electrohydraulic-generated shock waves to the insertion of the plantar fascia onto the calcaneus is a safe and effective nonsurgical method for treating chronic, recalcitrant heel pain syndrome that has been present for at least 6 months and has been refractory to other commonly used nonoperative therapies. This technology, when delivered using the OssaTron (High Medical Technology, Kreuz-lingen, Switzerland), has been approved by the Food and Drug Administration specifically for the treatment of chronic proximal plantar fasciitis. The results suggest that this therapeutic modality should be considered before any surgical options, and even may be preferable to cortisone injection, which has a recognized risk of rupture of the plantar fascia and recurrence of symptoms.

  10. Crown dimensions and proximal enamel thickness of mandibular second bicuspids.

    PubMed

    Fernandes, Sérgio Augusto; Vellini-Ferreira, Flávio; Scavone-Junior, Helio; Ferreira, Rívea Inês

    2011-01-01

    To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left). Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5%). The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47) and 7.70 mm (± 0.51), respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75) on the right to 8.38 mm (± 0.85) on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70) on the right and 8.65 mm (± 0.54) on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22) to 1.40 mm (± 0.17), on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21) and 1.46 mm (± 0.12). No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.

  11. [Osteoporotic fractures of the proximal femur. What's new?].

    PubMed

    Bonnaire, F; Straßberger, C; Kieb, M; Bula, P

    2012-10-01

    Proximal femoral fractures in the elderly are still increasing and are almost always associated with osteoporosis. Especially the over 80-year-olds are increasing and at risk in this respect. In the treatment of these patients new knowledge has been achieved over the last years. An interdisciplinary, multimodal approach with early involvement of internists, geriatricians, anesthetists, osteologists, social workers, care facilities and outpatient trauma and orthopedic surgeons seems to generate a better outcome with fewer complications. In cases of suspected proximal femoral fracture diagnostic imaging should include a computed tomography scan of the posterior pelvic ring to detect commonly occurring fragility fractures of the lateral mass of the sacrum. Early surgery within the first 48 h has a significant positive effect with respect to general and local complications and early mortality. Medical and organizational barriers to an early operation, such as anticoagulant medication, limited capability of communication due to mental dysfunction and lack of operation capacity are continuously declining and subsequently complication rates are decreasing annually in Germany. Endoprosthetics are still associated with higher perioperative mortality than osteosynthesis (4.4 % versus 5.8 %). The innovations in the field of implants and surgical technique also contribute to these lower complication rates. While endoprosthetic treatment is still the gold standard for severely dislocated femoral neck fractures, non-dislocated or slightly dislocated fractures should be fixed with a stable extramedullary implant. For pertrochanteric fractures extramedullary stabilization can only be recommended for stable types of fractures. Every instable trochanteric fracture should be fixed with an intramedullary implant. The use of third generation nails has implicated a significant reduction of complication rates regarding cut-out and reoperations. Rotational fixing of the head

  12. Treatment of proximal humerus fractures in the elderly

    PubMed Central

    Launonen, Antti P; Lepola, Vesa; Flinkkilä, Tapio; Laitinen, Minna; Paavola, Mika; Malmivaara, Antti

    2015-01-01

    Background and purpose There is no consensus on the treatment of proximal humerus fractures in the elderly. Patients and methods We conducted a systematic search of the medical literature for randomized controlled trials and controlled clinical trials from 1946 to Apr 30, 2014. Predefined PICOS criteria were used to search relevant publications. We included randomized controlled trials involving 2- to 4-part proximal humerus fractures in patients over 60 years of age that compared operative treatment to any operative or nonoperative treatment, with a minimum of 20 patients in each group and a minimum follow-up of 1 year. Outcomes had to be assessed with functional or disability measures, or a quality-of-life score. Results After 2 independent researchers had read 777 abstracts, 9 publications with 409 patients were accepted for the final analysis. No statistically significant differences were found between nonoperative treatment and operative treatment with a locking plate for any disability, for quality-of-life score, or for pain, in patients with 3- or 4-part fractures. In 4-part fractures, 2 trials found similar shoulder function between hemiarthroplasty and nonoperative treatment. 1 trial found slightly better health-related quality of life (higher EQ-5D scores) at 2-year follow-up after hemiarthroplasty. Complications were common in the operative treatment groups (10–29%). Interpretation Nonoperative treatment over locking plate systems and tension banding is weakly supported. 2 trials provided weak to moderate evidence that for 4-part fractures, shoulder function is not better with hemiarthroplasty than with nonoperative treatment. 1 of the trials provided limited evidence that health-related quality of life may be better at 2-year follow-up after hemiarthroplasty. There is a high risk of complications after operative treatment. PMID:25574643

  13. Oropharyngeal acid reflux and motility abnormalities of the proximal esophagus

    PubMed Central

    Passaretti, Sandro; Mazzoleni, Giorgia; Vailati, Cristian; Testoni, Pier Alberto

    2016-01-01

    AIM To investigate the relationship between pathological oropharyngeal (OP) acid exposure and esophageal motility in patients with extra-esophageal syndromes. METHODS In this prospective study we enrolled consecutive outpatients with extra-esophageal symptoms suspected to be related to gastroesophageal reflux disease (GERD). We enrolled only patients with a reflux symptom index (RSI) score-higher than 13 and with previous lung, allergy and ear, nose and throat evaluations excluding other specific diagnoses. All patients underwent 24-h OP pH-metry with the Dx probe and esophageal high-resolution manometry (HRM). Patients were divided into two groups on the basis of a normal or pathological pH-metric finding (Ryan Score) and all manometric characteristics of the two groups were compared. RESULTS We examined 135 patients with chronic extra-esophageal syndromes. Fifty-one were considered eligible for the study. Of these, 42 decided to participate in the protocol. Patients were divided into two groups on the basis of normal or pathological OP acid exposure. All the HRM parameters were compared for the two groups. Significant differences were found in the median upper esophageal sphincter resting pressure (median 71 mmHg vs 126 mmHg, P = 0.004) and the median proximal contractile integral (median 215.5 cm•mmHg•s vs 313.5 cm•mmHg•s, P = 0.039), both being lower in the group with pathological OP acid exposure, and the number of contractions with small or large breaks, which were more frequent in the same group. This group also had a larger number of peristaltic contractions with breaks in the 20 mmHg isobaric contour (38.7% vs 15.38%, P < 0.0001). CONCLUSION In patients with suspected GERD-related extra-esophageal syndromes pathological OP acid exposure was associated with weaker proximal esophageal motility. PMID:27833390

  14. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

    PubMed Central

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (pH 6.9 v 6.8; p > 0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mumol/h; p < 0.02) and vagally stimulated (834 (72) v 474 (66) mumol/h; p < 0.02), but not acid stimulated (3351 (678) v 2550 (456) mumol/h; p > 0.05) duodenal bicarbonate secretion compared with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid inhibition. These results show that the proton pump inhibitor, omeprazole, promotes proximal duodenal mucosal bicarbonate secretion apparently independent of its gastric acid inhibitory effect. The mechanism of action remains speculative. PMID:8566861

  15. Mesiodistal width and proximal enamel thickness of maxillary first bicuspids.

    PubMed

    Macha, Aurélio de Carvalho; Vellini-Ferreira, Flávio; Scavone-Junior, Helio; Ferreira, Rívea Inês

    2010-01-01

    This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left), selected from white patients (mean age: 23.7 +/- 4.2 years), who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the buccal side, to obtain 0.6-mm central sections. The mesiodistal crown width and proximal enamel thickness were measured using a stereoscopic microscope connected to a computer. Measurements for right and left teeth, as well as the mesial and distal enamel thicknesses in the total sample, were compared by the Wilcoxon test (alpha = 0.05). The mesiodistal crown width mean values found were 7.51 mm (+/- 0.54) on the right side and 7.53 mm (+/- 0.35) on the left side. The mean enamel thickness on the distal surfaces for both sides was 1.29 mm (right: s.d. = 0.12 and left: s.d. = 0.18). The mean values for the mesial surfaces were 1.08 mm (+/- 0.14) and 1.19 mm (+/- 0.25), on the right and the left sides, respectively. No significant differences were found between the crown measurements and enamel thicknesses on the left and right sides. However, enamel thickness was significantly greater on the distal surfaces. Reliable measurements of enamel thickness are useful to guide stripping, which may be an attractive alternative to tooth extraction because it allows the transverse arch dimension to be maintained.

  16. Effect of electroneutral luminal and basolateral lactate transport on intracellular pH in salamander proximal tubules

    PubMed Central

    1987-01-01

    We used microelectrodes to examine the effects of organic substrates, particularly lactate (Lac-), on the intracellular pH (pHi) and basolateral membrane potential (Vbl) in isolated, perfused proximal tubules of the tiger salamander. Exposure of the luminal and basolateral membranes to 3.6 mM Lac- caused pHi to increase by approximately 0.2, opposite to the decrease expected from nonionic diffusion of lactic acid (HLac) into the cell. Addition of Lac- to only the lumen also caused alkalinization, but only if Na+ was present. This alkalinization was not accompanied by immediate Vbl changes, which suggests that it involves luminal, electroneutral Na/Lac cotransport. Addition of Lac- to only the basolateral solution caused pHi to decrease by approximately 0.08. The initial rate of this acidification was a saturable function of [Lac-], was not affected by removal of Na+, and was reversibly reduced by alpha-cyano-4-hydroxycinnamate (CHC). Thus, the pHi decrease induced by basolateral Lac- appears to be due to the basolateral entry of H+ and Lac-, mediated by an H/Lac cotransporter (or a Lac-base exchanger). Our data suggest that this transporter is electroneutral and is not present at the luminal membrane. A key question is how the addition of Lac- to the lumen increases pHi. We found that inhibition of basolateral H/Lac cotransport by basolateral CHC reduced the initial rate of pHi increase caused by luminal Lac-. On the other hand, luminal CHC had no effect on the luminal Lac(-)-induced alkalinization. These data suggest that when Lac- is present in the lumen, it enters the cell from the lumen via electroneutral Na/Lac cotransport and then exists with H+ across the basolateral membrane via electroneutral H/Lac cotransport. The net effect is transepithelial Lac- reabsorption, basolateral acid extrusion, and intracellular alkalinization. PMID:3440860

  17. Involvement of the proximal tibiofibular joint in osteoarthritis of the knee.

    PubMed

    Oztuna, Volkan; Yildiz, Altan; Ozer, Caner; Milcan, Abtullah; Kuyurtar, Fehmi; Turgut, Akin

    2003-12-01

    This study was performed to evaluate the possible involvement of the proximal tibiofibular joint in primary osteoarthritis of the knee. A total of 40 patients with primary osteoarthritis of the knee who had magnetic resonance imaging scans were reexamined for proximal tibiofibular joint involvement. The patient was questioned if pain was present in the proximal tibiofibular joint while at rest, when walking and climbing stairs. Symptoms were evaluated by applying moderate compression over the proximal tibiofibular joint during active ankle and knee motions. Magnetic resonance imaging scans were reexamined by two radiologists. Three of the 40 patients had minimal or moderate pain in the proximal tibiofibular joint during stair-climbing and on clinical examination. Magnetic resonance imaging scans of these three patients revealed osteophyte or subchondral cyst formation, or both. Degenerative changes in the proximal tibiofibular joint may be evident in association with osteoarthritis of the knee and may result in lateral-sided pain at the knee.

  18. Successful treatment of proximal renal tubular acidosis and Fanconi syndrome with vitamin D replacement.

    PubMed

    Ali, Syed Ahsan; Tariq, Muhammad

    2016-01-01

    Proximal renal tubular acidosis (RTA), also known as Type II RTA, is characterized by a defect in the ability to reabsorb bicarbonate (HCO 3 ) in the proximal tubule. It is usually associated with generalized dysfunction of the proximal tubule as part of Fanconi syndrome. Very few case reports in the literature support Vitamin D deficiency as a cause of proximal RTA. We present a case of a young female who presented with proximal RTA and Fanconi syndrome and excellently responded to Vitamin D replacement. Thus, work-up for the etiology of proximal RTA should include Vitamin D levels since replacement of this vitamin in those who are deficient can lead to cure of such patients.

  19. Differential regulation of the renal sodium-phosphate cotransporters NaPi-IIa, NaPi-IIc, and PiT-2 in dietary potassium deficiency.

    PubMed

    Breusegem, Sophia Y; Takahashi, Hideaki; Giral-Arnal, Hector; Wang, Xiaoxin; Jiang, Tao; Verlander, Jill W; Wilson, Paul; Miyazaki-Anzai, Shinobu; Sutherland, Eileen; Caldas, Yupanqui; Blaine, Judith T; Segawa, Hiroko; Miyamoto, Ken-ichi; Barry, Nicholas P; Levi, Moshe

    2009-08-01

    Dietary potassium (K) deficiency is accompanied by phosphaturia and decreased renal brush border membrane (BBM) vesicle sodium (Na)-dependent phosphate (P(i)) transport activity. Our laboratory previously showed that K deficiency in rats leads to increased abundance in the proximal tubule BBM of the apical Na-P(i) cotransporter NaPi-IIa, but that the activity, diffusion, and clustering of NaPi-IIa could be modulated by the altered lipid composition of the K-deficient BBM (Zajicek HK, Wang H, Puttaparthi K, Halaihel N, Markovich D, Shayman J, Beliveau R, Wilson P, Rogers T, Levi M. Kidney Int 60: 694-704, 2001; Inoue M, Digman MA, Cheng M, Breusegem SY, Halaihel N, Sorribas V, Mantulin WW, Gratton E, Barry NP, Levi M. J Biol Chem 279: 49160-49171, 2004). Here we investigated the role of the renal Na-P(i) cotransporters NaPi-IIc and PiT-2 in K deficiency. Using Western blotting, immunofluorescence, and quantitative real-time PCR, we found that, in rats and in mice, K deficiency is associated with a dramatic decrease in the NaPi-IIc protein abundance in proximal tubular BBM and in NaPi-IIc mRNA. In addition, we documented the presence of a third Na-coupled P(i) transporter in the renal BBM, PiT-2, whose abundance is also decreased by dietary K deficiency in rats and in mice. Finally, electron microscopy showed subcellular redistribution of NaPi-IIc in K deficiency: in control rats, NaPi-IIc immunolabel was primarily in BBM microvilli, whereas, in K-deficient rats, NaPi-IIc BBM label was reduced, and immunolabel was prevalent in cytoplasmic vesicles. In summary, our results demonstrate that decreases in BBM abundance of the phosphate transporter NaPi-IIc and also PiT-2 might contribute to the phosphaturia of dietary K deficiency, and that the three renal BBM phosphate transporters characterized so far can be differentially regulated by dietary perturbations.

  20. Potassium depletion increases luminal Na+/H+ exchange and basolateral Na+:CO3=:HCO3- cotransport in rat renal cortex

    SciTech Connect

    Soleimani, M.; Bergman, J.A.; Hosford, M.A.; McKinney, T.D. )

    1990-10-01

    Most HCO3- reabsorption in proximal tubules occurs via electroneutral Na+/H+ exchange in brush border membranes (BBMS) and electrogenic Na+:CO3=:HCO3- cotransport in basolateral membranes (BLMS). Since potassium depletion (KD) increases HCO3- reabsorption in proximal tubules, we evaluated these transport systems using BBM and BLM vesicles, respectively, from control (C) and KD rats. Feeding rats a potassium deficient diet for 3-4 wk resulted in lower plasma (K+) (2.94 mEq/liter, KD vs. 4.47 C), and higher arterial pH (7.51 KD vs. 7.39 C). KD rats gained less weight than C but had higher renal cortical weight. Influx of 1 mM 22Na+ at 5 s (pHo 7.5, pHi 6.0, 10% CO2, 90% N2) into BLM vesicles was 44% higher in the KD group compared to C with no difference in equilibrium uptake. The increment in Na+ influx in the KD group was DIDS sensitive, suggesting that Na+:CO3=:HCO3- cotransport accounted for the observed differences. Kinetic analysis of Na+ influx showed a Km of 8.2 mM in KD vs. 7.6 mM in C and Vmax of 278 nmol/min/mg protein in KD vs. 177 nmol/min/mg protein in C. Influx of 1 mM 22Na+ at 5 s (pHo 7.5, pHi 6.0) into BBM vesicles was 34% higher in the KD group compared to C with no difference in equilibrium uptake. The increment in Na+ influx in the KD group was amiloride sensitive, suggesting that Na+/H+ exchange was responsible for the observed differences. Kinetic analysis of Na+ influx showed a Km of 6.2 mM in KD vs. 7.1 mM in C and Vmax of 209 nmol/min/mg protein in KD vs. 144 nmol/min/mg protein in C. Uptakes of Na(+)-dependent (3H)glucose into BBM and (14C)succinate into BLM vesicles were not different in KD and C groups, suggesting that the Na+/H+ exchanger and Na+:CO3=:HCO3- cotransporter activities were specifically altered in KD.

  1. Analysis of Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol

    NASA Technical Reports Server (NTRS)

    Woo, Simon S.

    2011-01-01

    To synchronize clocks between spacecraft in proximity, the Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol has been proposed. PITS is based on the NTP Interleaved On-Wire Protocol and is capable of being adapted and integrated into CCSDS Proximity-1 Space Link Protocol with minimal modifications. In this work, we will discuss the correctness and liveness of PITS. Further, we analyze and evaluate the performance of time synchronization latency with various channel error rates in different PITS operational modes.

  2. A dual-mode proximity sensor with integrated capacitive and temperature sensing units

    NASA Astrophysics Data System (ADS)

    Qiu, Shihua; Huang, Ying; He, Xiaoyue; Sun, Zhiguang; Liu, Ping; Liu, Caixia

    2015-10-01

    The proximity sensor is one of the most important devices in the field of robot application. It can accurately provide the proximity information to assistant robots to interact with human beings and the external environment safely. In this paper, we have proposed and demonstrated a dual-mode proximity sensor composed of capacitive and resistive sensing units. We defined the capacitive type proximity sensor perceiving the proximity information as C-mode and the resistive type proximity sensor detecting as R-mode. Graphene nanoplatelets (GNPs) were chosen as the R-mode sensing material because of its high performance. The dual-mode proximity sensor presents the following features: (1) the sensing distance of the dual-mode proximity sensor has been enlarged compared with the single capacitive proximity sensor in the same geometrical pattern; (2) experiments have verified that the proposed sensor can sense the proximity information of different materials; (3) the proximity sensing capability of the sensor has been improved by two modes perceive collaboratively, for a plastic block at a temperature of 60 °C: the R-mode will perceive the proximity information when the distance d between the sensor and object is 6.0-17.0 mm and the C-mode will do that when their interval is 0-2.0 mm additionally two modes will work together when the distance is 2.0-6.0 mm. These features indicate our transducer is very valuable in skin-like sensing applications.

  3. Double Stent Assist Coiling of Ruptured Large Saccular Aneurysm in Proximal Basilar Artery Fenestration

    PubMed Central

    Park, Woong Bae; Huh, Joon; Cho, Chul Bum; Yang, Seung Ho; Kim, Il Sup; Hong, Jae Taek; Lee, Sang Won

    2015-01-01

    Basilar artery fenestration is infrequent and even rarer in association with a large aneurysm. With proximity to brain stem and vital perforators, endovascular coiling can be considered first. If the large ruptured aneurysm with a wide neck originated from fenestra of the proximal basilar artery and the fenestration loop has branches of posterior circulation, therapeutic consideration should be thorough and fractionized. We report endovascular therapeutic details for a case of a ruptured large saccular aneurysm in proximal basilar artery fenestration. PMID:26523257

  4. Thyroid hormones increase Na -H exchange activity in renal brush border membranes

    SciTech Connect

    Kinsella, J.; Sacktor, B.

    1985-06-01

    Na -H exchange activity, i.e., amiloride-sensitive Na and H flux, in renal proximal tubule brush border (luminal) membrane vesicles was increased in the hyperthyroid rat and decreased in the hypothyroid rat, relative to the euthyroid animal. A positive correlation was found between Na -H exchange activity and serum concentrations of thyroxine (T4) and triiodothyronine (T3). The thyroid status of the animal did not alter amiloride-insensitive Na uptake. The rate of passive pH gradient dissipation was higher in membrane vesicles from hyperthyroid rats compared to the rate in vesicles from hypothyroid animals, a result which would tend to limit the increase in Na uptake in vesicles from hyperthyroid animals. Na -dependent phosphate uptake was increased in membrane vesicles from hyperthyroid rats; Na -dependent D-glucose and L-proline uptakes were not changed by the thyroid status of the animal. The effect of thyroid hormones in increasing the uptake of Na in the brush border membrane vesicle is consistent with the action of the hormones in enhancing renal Na reabsorption.

  5. Coxa vara with proximal femoral growth arrest in patients who had neonatal extracorporeal membrane oxygenation.

    PubMed

    DiFazio, Rachel L; Kocher, Minider S; Berven, Sigurd; Kasser, James

    2003-01-01

    This is a retrospective review of four patients in whom a pattern of coxa vara with proximal femoral growth arrest and metaphyseal irregularities developed. These patients were all treated with neonatal extracorporeal membrane oxygenation and presented with a progressive gait disturbance and pain, leg-length discrepancy, and limited abduction. Imaging revealed coxa vara with proximal femoral growth arrest. Two patients (three hips) underwent proximal femoral valgus osteotomy, one patient underwent fixation of a femoral neck fracture with subsequent greater trochanter transfer, and one patient is being observed. This case series suggests an association between neonatal extracorporeal membrane oxygenation and this unusual pattern of coxa vara with proximal femoral growth arrest.

  6. A pathway-centric view of spatial proximity in the 3D nucleome across cell lines

    PubMed Central

    Karathia, Hiren; Kingsford, Carl; Girvan, Michelle; Hannenhalli, Sridhar

    2016-01-01

    In various contexts, spatially proximal genes have been shown to be functionally related. However, the extent to which spatial proximity of genes in a pathway contributes to the pathway’s context-specific activity is not known. Leveraging Hi-C data in six human cell-lines, we show that spatial proximity of genes in a pathway is highly correlated with the pathway’s context-specific expression and function. Furthermore, spatial proximity of pathway genes correlates with interactions of their protein products, and the specific pathway genes that are proximal to one another tend to occupy higher levels in the regulatory hierarchy. In addition to intra-pathway proximity, related pathways are spatially proximal to one another and housekeeping-genes tend to be proximal to several other pathways suggesting their coordinating role. Substantially extending previous works, our study reveals a pathway-centric organization of 3D-nucleome, whereby, functionally related interacting driver genes tend to be in spatial-proximity in a context-specific manner. PMID:27976707

  7. The functional results of tibial shaft fractures treated with intramedullary nail compressed by proximal tube.

    PubMed

    Karaarslan, Ahmet Adnan; Acar, Nihat; Aycan, Hakan; Sesli, Erhan

    2016-04-01

    Nailing of tibial shaft fractures is considered the gold standard surgical method by many surgeons. The aim of this retrospective study was to investigate and compare the clinical outcome of tibial shaft fractures treated with intramedullary nails compressed by proximal tube and conventional intramedullary interlocking nails. Fifty-seven patients with tibial shaft fractures, treated with intramedullary nails compressed by proximal tube (n = 32) and the conventional interlocking nails (n = 25), were reviewed. All fractures except for one were united without any additional surgical intervention in the proximal compression tube nail group, whereas in the conventional interlocking nail group, six patients needed dynamization surgery (p = 0.005) and three cases of nonunion were recorded. In the proximal compression tube nail group, faster union occurred in 20 ± 2 (16-24) weeks (mean ± SD; range) without failure of locking screws and proximal nail migration, whereas in the conventional interlocking nail group, union occurred in 22 ± 2.5 (17-27) weeks (p = 0.001) with two failures of locking screws and two proximal nail migration. The proximal compression tube nail system is safer than the conventional nailing methods for the treatment for transverse and oblique tibial shaft fractures with a less rate of nonunion, proximal locking screw failure and proximal nail migration.

  8. A triple-barreled microelectrode for simultaneous measurements of intracellular Na+ and K+ activities and membrane potential in biological cells.

    PubMed

    Fujimoto, M; Honda, M

    1980-01-01

    A triple-barreled Na+, K+-selective microelectrode was constructed with liquid ion exchangers for Na+ (monensin) and K+ (Corning #477317) to measure the intracellular Na+ and K+ activities ((Na)i and (K)i) of a single cell and its membrane potential (EM), simultaneously. The tip of the triple-barreled assembly was made less than 0.6 micron in outside diameter. Prior to in vivo measurements, some physiochemical properties of microelectrodes were examined in vitro for the slope constant, selectivity coefficient, electrical resistance, and pH effect, as well as measurements of the activity coefficient on ions in blood serum and Ringer solution. Carrying out direct micropunctures on single cells of the sartorius muscle and renal proximal tubule of bullfrogs in vivo, we obtained the following results: (1) In sartorius muscle, the average (Na)i was 14.8 mEq/liter, the (K)i 64.5 mEq/liter, and the EM -86.2 mV. (2) In proximal tubule cells, the average (Na)i, (K)i and EM were 16.8, 63.0 mEq/liter and -65.9 mV, respectively. (3) There were significant correlations in the proximal tubule between (K)i and EM, and inversely between (Na)i and EM, and between (Na)i and (K)i. These facts may somehow be related to both the activity of Na+-K+ exchange pump and the osmotic equilibrium of water across the membrane. Further, several problems inherent in the multibarreled microelectrode were discussed from the practical point of view.

  9. Proximal Blade Twist Feedback Control for Heliogyro Solar Sails

    NASA Astrophysics Data System (ADS)

    Smith, Sarah Mitchell

    mode is on the order of 0.005%, meaning there is almost no inherent damping in the blade. Next, the proximal blade twist feedback control design was successful in overcoming friction in the root actuator and added damping to the blade. The damping ratio for the lowest frequency torsional mode was increased from 0.001% to 0.09%, which is a significant amount for a heliogyro spacecraft. Finally, the camera sensor used for the proximal differential twist measurement proved to be feasible and quantization from these measurements only decreased the damping ratio to 0.075%. This research provides the first indication that a physically realizable blade root controller can deal with friction in an effective way, thus taking a step towards advancing the technology readiness level of the heliogyro spacecraft.

  10. Treatment of proximal fifth metatarsal bone fractures in athletes.

    PubMed

    Japjec, M; Starešinić, M; Starjački, M; Žgaljardić, I; Štivičić, J; Šebečić, B

    2015-11-01

    Proximal fifth metatarsal (V MT) bone fractures are common injuries that are a major diagnostic and therapeutic challenge. Lawrence and Botte considered different treatment options and the possibility of recovery and divided these fractures into three different regions: tuberosity avulsion fractures (zone I), acute fractures of the metaphysis at the level of the intermetatarsal junction (zone II) and proximal diaphysis stress fracture (zone III). A total of 42 athletes with fracture of the V MT bone in zone II and III were treated in our institution during a 6-year period. All patients were offered surgical treatment, but nine patients refused surgery. Thus, the patients were divided into two groups: group 1 comprised 33 patients who underwent an intramedullary screw fixation operation under regional anaesthesia immediately after the fracture was diagnosed; group 2 contained the remaining nine patients who had refused surgery and received conservative therapy with non-weight-bearing short-leg casts or orthosis. Follow-up ranged from 6 to 24 months. All fractures healed in group 1: healing occurred within 8 weeks in 26 patients and was prolonged to 16 to 18 weeks in four patients. In group 2, fractures healed in four patients but did not heal in five patients even after 6 months. Four of the five patients in whom the fracture did not heal required subsequent osteosynthesis because they had constant problems that caused absence from sport. After the operation, their fractures healed in an average of 10 weeks. One patient decided not to undergo the operation due to the absence of subjective symptoms. Three patients in group 1 who started intensive training sustained a refracture and underwent re-operation in which osteosynthesis was performed with a stronger screw. The fractures then healed again. Treatment results were evaluated radiologically and clinically using the Modified Foot Score. Results in group 1 were significantly better than those in group 2 and there

  11. [Fractures of the proximal femur: rehabilitation and socioeconomic repercussions].

    PubMed

    Meine, J; Regazzoni, P; König, W

    1993-01-01

    Only insufficient statistical data for epidemiologic analysis and calculations of socioeconomic costs are available in Switzerland. The total number of fractures of the proximal femur per year has nearly doubled in the 10 years from 1980 to 1990, climbing from 5500 to 9800 cases. A number of 15,000 cases is foreseen for the year 2020. In 85% of the cases the patients are older than 65 years. The global annual incidence is estimated to be 145/100,000, the partial incidence for the population of more than 65 years being 825/100,000. The mean hospitalization is 30 days. The total number of hospital days per year climbed from 200,000 to 300,000 in ten years, thus increasing the number of required beds by 50%. The mean costs for primary hospitalization is estimated to 15,000.-Swiss francs per case in 1990 and 146 Million francs globally per annum, i.e. the double of the amount in 1980. In the statistics of the National Accident Insurance Company the mean global economic costs for a fracture of the proximal femur in the active population is 57,000.-Swiss francs approximately and 72,000.-francs for patients of more than 45 years of age. Only roughly 20% of the costs are caused by medical treatment, whereas pensions, per diems and other compensations produce 80% of the costs. The mortality for patients over 65 varies from 2-7% during the primary hospitalization and rises up to 30% after 1 to 2 years after the accident. The relationship between the duration of acute hospitalization and rehabilitation is essential for planning. The evaluation of the chances for a successful rehabilitation is very important, the general medical conditions of the patients before the accident being the main determinant factor. A mean hospitalization of 3 weeks in a surgical unit and 6 to 7 weeks in a rehabilitation hospital seems to be realistic. Appropriate criteria for the selection of patients amenable to successful rehabilitation are essential. The question of the social outcome of these

  12. Proximal femoral reconstruction after aseptic loosening following proximal femoral replacement for Ewing sarcoma: a case report with one-year follow-up.

    PubMed

    Schoof, Benjamin; Jakobs, Oliver; Gehrke, Thorsten; Gebauer, Matthias

    2014-01-01

    We report the case of a 30-year-old patient initially treated for a proximal femoral Ewing's sarcoma when 12 years old. Index treatment comprised tumour resection and total hip arthroplasty. Two years later revision for aseptic loosening was performed. Subsequently, six further surgical revisons were performed for varying causes. At the age of 23 years the proximal femur was resected and a proximal femoral endoprosthesis implanted.Eighteen years after initial diagnosis the patient presented with recurrent aseptc loosening. Both the proximal femur and acetabulum were reconstructed. For acetabular reconstruction a structural allograft and a tantalum cup were utilised. Reconstruction of the femur utilsed extensive wire mesh and circlage wiring with impaction bone allograft into which a femoral stem was implanted.At one-year follow-up the patient was pain free, had no evidence of infection with satisfactory radiographs and no evidence of implant loosening. This is the first case reporting an extended proximal femoral reconstruction with a wire mesh in combination with impaction bone grafting in an aseptic loosened proximal femoral replacement following Ewing's Sarcoma.

  13. Proximal renal tubular acidosis: a not so rare disorder of multiple etiologies

    PubMed Central

    Haque, Syed K.; Ariceta, Gema; Batlle, Daniel

    2012-01-01

    Proximal renal tubular acidosis (RTA) (Type II RTA) is characterized by a defect in the ability to reabsorb HCO3 in the proximal tubule. This is usually manifested as bicarbonate wastage in the urine reflecting that the defect in proximal tubular transport is severe enough that the capacity for bicarbonate reabsorption in the thick ascending limb of Henle's loop and more distal nephron segments is overwhelmed. More subtle defects in proximal bicarbonate transport likely go clinically unrecognized owing to compensatory reabsorption of bicarbonate distally. Inherited proximal RTA is more commonly autosomal recessive and has been associated with mutations in the basolateral sodium-bicarbonate cotransporter (NBCe1). Mutations in this transporter lead to reduced activity and/or trafficking, thus disrupting the normal bicarbonate reabsorption process of the proximal tubules. As an isolated defect for bicarbonate transport, proximal RTA is rare and is more often associated with the Fanconi syndrome characterized by urinary wastage of solutes like phosphate, uric acid, glucose, amino acids, low-molecular-weight proteins as well as bicarbonate. A vast array of rare tubular disorders may cause proximal RTA but most commonly it is induced by drugs. With the exception of carbonic anhydrase inhibitors which cause isolated proximal RTA, drug-induced proximal RTA is associated with Fanconi syndrome. Drugs that have been recently recognized to cause severe proximal RTA with Fanconi syndrome include ifosfamide, valproic acid and various antiretrovirals such as Tenofovir particularly when given to human immunodeficiency virus patients receiving concomitantly protease inhibitors such as ritonavir or reverse transcriptase inhibitors such as didanosine. PMID:23235953

  14. Oesophageal tone and sensation in the transition zone between proximal striated and distal smooth muscle oesophagus.

    PubMed

    Karamanolis, G; Stevens, W; Vos, R; Tack, J; Clave, P; Sifrim, D

    2008-04-01

    Previous studies have shown that the proximal striated muscle oesophagus is less compliant and more sensitive than the distal smooth muscle oesophagus. Conventional and high resolution manometry described a transition zone between striated and smooth muscle oesophagus. We aimed to evaluate oesophageal tone and sensitivity at the transition zone of oesophagus in healthy volunteers. In 18 subjects (seven men, mean age: 28 years) an oesophageal barostat study was performed. Tone and sensitivity were assessed using stepwise isobaric distensions with the balloon located at transition zone and at distal oesophagus in random order. To study the effect induced on transition zone by a previous distension at the distal oesophagus and vice versa, identical protocol was repeated after 7 days with inverted order. Initial distension of a region is referred to as 'naïf' distension and distension of a region following the distension of the other segment as 'primed' distension. Assessment of three oesophageal symptoms (chest pain, heartburn and 'other') was obtained at the end of every distension step. Compliance was significantly higher in the transition zone than in the distal oesophagus (1.47 +/- 0.14 vs 1.09 +/- 0.09 mL mmHg(-1), P = 0.03) after 'naif' distensions. This difference was not observed during 'primed' distensions. Higher sensitivity at transition zone level was found in 11/18 (61%) subjects compared to 6/18 (33%, P < 0.05) at smooth muscle oesophagus. Chest pain and 'other' symptom were more often induced by distention of the transition zone, whereas heartburn was equally triggered by distension of either region. The transition zone is more complaint and more sensitive than smooth muscle oesophagus.

  15. Proliferation and intracellular pH in cultured proximal tubular cells

    SciTech Connect

    Larsson, S.H.; Fukuda, Y.; Koelare, S.A.; Aperia, A. )

    1990-03-01

    Renal proximal tubule (PT) cells from adult rats will maintain much of their functional characteristics in short-term primary culture. This study examines the growth regulation of these highly differentiated cells with particular reference to cell density, intracellular pH (pHi), and the expression of the Na(+)-H+ exchanger. PT cells were obtained from young adult rats and studied after 48 h in culture. The mitotic rate was determined as the labeling index (LI) after (3H)thymidine autoradiography, and pHi was determined by 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein quantitative fluorescence microscopy in single cells. Cells were grown either continuously in serum (S) or were serum deprived after 24 h (D). The cells were nonconfluent and grew in colonies. We defined the two peripheral layers of cells in a colony as peripheral (P) cells and the remaining cells as central (C). In C cells LI/h and pHi were in the range of what has been observed under in vivo conditions. In S condition LI/h was 2.2 +/- 0.3% and in D condition was 0.3 +/- 0.1%. LI was significantly higher in P than in C cells both under S (2.5 +/- 0.4-fold) and D conditions (5.6 +/- 0.8-fold). The rapidly growing P cells had a significantly lower pHi than the growth-retarded C cells both under S (7.25 +/- 0.02 vs. 7.30 +/- 0.01, P less than 0.05) and D conditions (7.21 +/- 0.02 vs. 7.28 +/- 0.01, P less than 0.05).

  16. Characterization of FGF23-Dependent Egr-1 Cistrome in the Mouse Renal Proximal Tubule

    PubMed Central

    Portale, Anthony A.; Zhang, Martin Y. H.; David, Valentin; Martin, Aline; Jiao, Yan; Gu, Weikuan; Perwad, Farzana

    2015-01-01

    Fibroblast growth factor 23 (FGF23) is a potent regulator of phosphate (Pi) and vitamin D homeostasis. The transcription factor, early growth response 1 (egr-1), is a biomarker for FGF23-induced activation of the ERK1/2 signaling pathway. We have shown that ERK1/2 signaling blockade suppresses renal egr-1 gene expression and prevents FGF23-induced hypophosphatemia and 1,25-dihydroxyvitamin D (1,25(OH)2D) suppression in mice. To test whether egr-1 itself mediates these renal actions of FGF23, we administered FGF23 to egr-1-/- and wild-type (WT) mice. In WT mice, FGF23 induced hypophosphatemia and suppressed expression of the renal Na/Pi cotransporters, Npt2a and Npt2c. In FGF23-treated egr-1-/- mice, hypophosphatemic response was greatly blunted and Na/Pi cotransporter expression was not suppressed. In contrast, FGF23 induced equivalent suppression of serum 1,25(OH)2D concentrations by suppressing renal cyp27b1 and stimulating cyp24a1 mRNA expression in both groups of mice. Thus, downstream of receptor binding and ERK1/2 signaling, we can distinguish the effector pathway that mediates FGF23-dependent inhibition of Pi transport from the pathway that mediates inhibition of 1,25(OH)2D synthesis in the kidney. Furthermore, we demonstrate that the hypophosphatemic effect of FGF23 is significantly blunted in Hyp/egr-1-/- mice; specifically, serum Pi concentrations and renal Npt2a and Npt2c mRNA expression are significantly higher in Hyp/egr-1-/- mice than in Hyp mice. We then characterized the egr-1 cistrome in the kidney using ChIP-sequencing and demonstrate recruitment of egr-1 to regulatory DNA elements in proximity to several genes involved in Pi transport. Thus, our data demonstrate that the effect of FGF23 on Pi homeostasis is mediated, at least in part, by activation of egr-1. PMID:26588476

  17. Comparison between calcium transport and adenosine triphosphatase activity in membrane vesicles derived from rabbit kidney proximal tubules.

    PubMed

    Vieyra, A; Nachbin, L; de Dios-Abad, E; Goldfeld, M; Meyer-Fernandes, J R; de Moraes, L

    1986-03-25

    Characteristics of Ca2+ uptake were studied in a vesicular preparation of proximal tubule plasma membranes from rabbit kidney and compared with the properties of both membrane-bound and solubilized Ca2+-ATPase activities. Calcium uptake required both ATP and MgCl2 and revealed two kinetic components with respect to Ca2+ concentration requirements, one with a high affinity for Ca2+ (1.8 microM), operative in the range of cytosolic Ca2+ activity, and one with a low affinity for Ca2+ (250 microM) which may become active only at abnormally high cytosolic Ca2+ concentrations. The high- and low-affinity components were stimulated to similar extents by phosphate, and required similar concentrations of ATP (0.6 mM) for half-maximal activity. The amount of membrane-bound phosphoenzyme formed from ATP in the presence of Ca2+ was the same regardless of whether only one or both sites were saturated, suggesting that occupancy of the second Ca2+ binding site accelerates the enzyme turnover. Inhibition of Ca2+ transport by Na+ was reversed by the addition of ouabain or an ATP-regenerating system, indicating that this inhibitory effect of Na+ on Ca2+ uptake may be due to the accumulation of ADP in the medium as a result of Na+ pump activity. Low concentrations of carbonyl cyanide p-trifluoromethoxyphenylhydrazone and valinomycin (2.5 and 1 microM, respectively) were without effect on Ca2+ uptake in the presence of phosphate, whereas higher concentrations of the ionophores (200 and 100 microM, respectively) reduced uptake by 60% or more. The calmodulin antagonist 48/80 also reduced Ca2+ uptake with half-maximal effectiveness at 100 micrograms/ml. None of these drugs affected either ATPase activity or the EGTA-induced Ca2+ efflux from preloaded vesicles. The Ca2+ dependence of ATP hydrolysis by the membrane-bound enzyme preparation was similar to that observed for Ca2+ uptake by the vesicles. However, with solubilized enzyme, concentrations of Ca2+ similar to that found in the

  18. Studying in the region of proximal learning reduces mind wandering.

    PubMed

    Xu, Judy; Metcalfe, Janet

    2016-07-01

    Insofar as mind wandering has been linked to poor learning, finding ways to reduce the propensity to mind wander should have implications for improving learning. We investigated the possibility that studying materials at an appropriate level of difficulty with respect to the individual's capabilities-that is, studying in the region of proximal learning (RPL)-might reduce mind wandering. In Experiments 1 and 2, participants were probed for their attentional state while they studied blocks of English-Spanish word pairs that were (a) easy, (b) in the RPL, or (c) difficult. We found that studying materials in the RPL was associated with reduced mind wandering. Test performance on items studied while mind wandering was also poorer. In Experiment 3, we investigated the relation between differences in participants' mastery and mind wandering. We found that high performers mind wandered more when studying the easier word pairs, whereas low performers mind wandered more when studying the difficult items. These results indicate that the RPL is specific to the individual's level of mastery and that mind wandering occurs when people are outside that region.

  19. A stochastic self-organizing map for proximity data.

    PubMed

    Graepel, T; Obermayer, K

    1999-01-01

    We derive an efficient algorithm for topographic mapping of proximity data (TMP), which can be seen as an extension of Kohonen's self-organizing map to arbitrary distance measures. The TMP cost function is derived in a Baysian framework of folded Markov chains for the description of autoencoders. It incorporates the data by a dissimilarity matrix D and the topographic neighborhood by a matrix H of transition probabilities. From the principle of maximum entropy, a nonfactorizing Gibbs distribution is obtained, which is approximated in a mean-field fashion. This allows for maximum likelihood estimation using an expectation-maximization algorithm. In analogy to the transition from topographic vector quantization to the self-organizing map, we suggest an approximation to TMP that is computationally more efficient. In order to prevent convergence to local minima, an annealing scheme in the temperature parameter is introduced, for which the critical temperature of the first phase transition is calculated in terms of D and H. Numerical results demonstrate the working of the algorithm and confirm the analytical results. Finally, the algorithm is used to generate a connection map of areas of the cat's cerebral cortex.

  20. Proximal Tubules Have the Capacity to Regulate Uptake of Albumin.

    PubMed

    Wagner, Mark C; Campos-Bilderback, Silvia B; Chowdhury, Mahboob; Flores, Brittany; Lai, Xianyin; Myslinski, Jered; Pandit, Sweekar; Sandoval, Ruben M; Wean, Sarah E; Wei, Yuan; Satlin, Lisa M; Wiggins, Roger C; Witzmann, Frank A; Molitoris, Bruce A

    2016-02-01

    Evidence from multiple studies supports the concept that both glomerular filtration and proximal tubule (PT) reclamation affect urinary albumin excretion rate. To better understand these roles of glomerular filtration and PT uptake, we investigated these processes in two distinct animal models. In a rat model of acute exogenous albumin overload, we quantified glomerular sieving coefficients (GSC) and PT uptake of Texas Red-labeled rat serum albumin using two-photon intravital microscopy. No change in GSC was observed, but a significant decrease in PT albumin uptake was quantified. In a second model, loss of endogenous albumin was induced in rats by podocyte-specific transgenic expression of diphtheria toxin receptor. In these albumin-deficient rats, exposure to diphtheria toxin induced an increase in albumin GSC and albumin filtration, resulting in increased exposure of the PTs to endogenous albumin. In this case, PT albumin reabsorption was markedly increased. Analysis of known albumin receptors and assessment of cortical protein expression in the albumin overload model, conducted to identify potential proteins and pathways affected by acute protein overload, revealed changes in the expression levels of calreticulin, disabled homolog 2, NRF2, angiopoietin-2, and proteins involved in ATP synthesis. Taken together, these results suggest that a regulated PT cell albumin uptake system can respond rapidly to different physiologic conditions to minimize alterations in serum albumin level.

  1. Collaboration range: Effects of geographical proximity on article impact

    NASA Astrophysics Data System (ADS)

    Apolloni, Andrea; Rouquier, Jean-Baptiste; Jensen, Pablo

    2013-09-01

    Spatial scientometrics studies how geography influences knowledge creation. In the recent years there has been a surge in this kind of studies, due to the increase of international collaborations. Most of the work in this field has been focused on the geographical distribution of researchers, whilst few have considered how proximity between coauthors influences research quality. In this work we leverage a dataset of geolocalized articles to assess the effect of geographical distance on article impact. More precisely, the dataset, provided by the Observatory of Science and Technology (O.S.T.), consists of roughly 106 scientific articles, gathering all European articles written in 2000 and 2007, spanning 9 disciplines. We evaluate under which geographical extent coauthorships have higher probability of resulting in high impact articles ("high impact" is here approximated by "being in the top 10% most cited articles of its discipline"). We also describe spatial distribution of coauthorship, delineating geographical areas where the production is proportionally higher. The distribution is evaluated both in term of km (as the crow flies), and in terms of administrative partitions (authors' cities, regions, countries).

  2. Norepinephrines effect on adenosine transport in the proximal straight tubule

    SciTech Connect

    Barfuss, D.W.; McCann, W.P.; Katholi, R.E.

    1986-03-01

    The effect of norepinephrine on C/sup 14/-adenosine transport in the rabbit proximal tubule (S/sub 2/) was studied. The transepithelial transport of adenosine (0.02 mM0 from lumin to bathing solution was measured by its rate of appearance (J/sub A/) in the bathing solution and by its disappearances (J/sub D/) from the luminal fluid. Norepinephrine (0.24 ..mu..M) was added to the bathing solution after a control flux period. After three samples from the experiment period the tubules were quickly harvested and the cellular concentration of C/sup 14/-adenosine was determined. The high cellular adenosine concentration and th marked difference in adenosine appearance rate in the bathing solution compared to the luminal disappearance rate indicates the absorbed adenosine is trapped in the cells. This trapping may be due to adenosine metabolism or difficulty of crossing the basolateral membrane. Whichever is the case, norepinephrine appears to stimulate movement of adenosine or its metabolites into the bathing solution across the basolateral membrane.

  3. Interactive displays for trajectory planning and proximity operations

    NASA Technical Reports Server (NTRS)

    Brody, Adam R.; Ellis, Stephen R.; Grunwald, Arthur; Haines, Richard F.

    1993-01-01

    Rendezvous, docking, and other Space Station proximity operations (PROX OPS) will be conducted routinely in space. Real-time interactive visual aids and planning tools will be helpful, if not necessary, for future missions both in preflight training and on orbit. Two such displays, eivaN and Navie, are currently available for examination and human factors testing. A study was conducted in which data were collected from eight test subjects. Solution times for both devices decreased rapidly with experience. Neither fuel usage nor the number of waypoints (burns) decreased with experience. With Navie, medians of solution time and fuel consumption totaled over all subjects peaked at one of two starting points above the V-bar with monotonically decreasing values in both directions. This pattern did not appear with eivaN values. Since the docking tasks were fundamentally different with each device, and because Navie imposed more constraints on the users than eivaN did, the orbital mechanics effects had a more pronounced effect on the Navie results than on the eivaN data.

  4. Predicting Performance in Higher Education Using Proximal Predictors.

    PubMed

    Niessen, A Susan M; Meijer, Rob R; Tendeiro, Jorge N

    2016-01-01

    We studied the validity of two methods for predicting academic performance and student-program fit that were proximal to important study criteria. Applicants to an undergraduate psychology program participated in a selection procedure containing a trial-studying test based on a work sample approach, and specific skills tests in English and math. Test scores were used to predict academic achievement and progress after the first year, achievement in specific course types, enrollment, and dropout after the first year. All tests showed positive significant correlations with the criteria. The trial-studying test was consistently the best predictor in the admission procedure. We found no significant differences between the predictive validity of the trial-studying test and prior educational performance, and substantial shared explained variance between the two predictors. Only applicants with lower trial-studying scores were significantly less likely to enroll in the program. In conclusion, the trial-studying test yielded predictive validities similar to that of prior educational performance and possibly enabled self-selection. In admissions aimed at student-program fit, or in admissions in which past educational performance is difficult to use, a trial-studying test is a good instrument to predict academic performance.

  5. Repair of injured proximal tubule does not involve specialized progenitors

    PubMed Central

    Humphreys, Benjamin D.; Czerniak, Suzanne; DiRocco, Derek P.; Hasnain, Wirasat; Cheema, Rabia; Bonventre, Joseph V.

    2011-01-01

    Recently we have established that the kidney tubular epithelium is repaired by surviving epithelial cells. It is not known, however, whether a population of intratubular adult progenitor cells are responsible for this epithelial repair after acute kidney injury. In this study, we used an unbiased DNA analog-based approach that does not rely on candidate markers to track multiple rounds of cell division in vivo. In the proximal tubule, robust thymidine analog incorporation was observed postinjury. Cell division was stochastic and enriched among cells that were injured and dedifferentiated. There was no evidence for the presence of a population of specialized progenitors that repeatedly divide in response to injury. Instead, these results indicate that after injury, new epithelial cells arise from self-duplication of surviving cells, most of which are injured. Because the renal papilla contains DNA label-retaining cells and has been proposed as a stem cell niche, we examined the proliferative behavior of these putative progenitors after ischemia-reperfusion injury. Although label-retaining cells in the renal papilla diminished with time after ischemia-reperfusion injury, they neither proliferated nor migrated to the outer medulla or cortex. Thus, nonlethally injured cells repopulate the kidney epithelium after injury in the absence of any specialized progenitor cell population. PMID:21576461

  6. Multilayered graphene acquires ferromagnetism in proximity with magnetite particles

    SciTech Connect

    Seifu, Dereje Neupane, Suman; Giri, Lily; Karna, Shashi P.; Hong, Haiping; Seehra, M. S.

    2015-05-25

    Anisotropic diamagnetism of pristine graphite and graphene is well known. Here, evidence of significant induced ferromagnetism in multilayer graphene (MLG) decorated with ferrimagnetic Fe{sub 3}O{sub 4} particles is reported. This MLG-Fe{sub 3}O{sub 4} nano-composite was prepared by a one-step ultrasonic treatment at 75 °C in the surfactant sodium dodecyl-benzene-sulfonate. To verify the phase structure and morphology of the composite, X-ray diffraction, scanning and transmission electron microscopy, scanning tunneling electron microscopy, and Raman spectroscopy were employed. Room temperature data of magnetization versus magnetic field showed that the saturation magnetization M{sub S} = 58.6 emu/gm for pristine Fe{sub 3}O{sub 4} increased to M{sub S} = 158.4 emu/gm for a 1:1 composite of Fe{sub 3}O{sub 4} to MLG. These results lead to induced M{sub S} = 253 emu/gm in MLG resulting from its proximity to Fe{sub 3}O{sub 4}. Similar experiments on Fe{sub 3}O{sub 4} to single walled carbon nanotubes (SWNT) composite did not show any induced magnetism in SWNT.

  7. Expert opinion: diagnosis and treatment of proximal hamstring tendinopathy

    PubMed Central

    Lempainen, Lasse; Johansson, Kristian; Banke, Ingo J.; Ranne, Juha; Mäkelä, Keijo; Sarimo, Janne; Niemi, Pekka; Orava, Sakari

    2015-01-01

    Summary Background: proximal hamstring tendinopathy (PHT) is a disabilitating disease often causing underperformance in the athletically demanding patients. The main symptom of PHT is lower gluteal pain especially during running or while prolonged sitting. Mainly affecting athletically active individuals, PHT is a considerable challenge for treating health care professionals. Purpose: this paper aims to concisely present the literature on PHT to guide health care professionals treating these patients and doing research on the subject. Methods: we reviewed the literature on PHT through literature search of scientific journal databases. Conclusions: as a tendinopathic pathology, it is a rather recently discovered exertion injury. As with other chronic tendon overuse injuries, current treatment strategies are unspecific with uncertain outcomes due to the unknown etiology of the tendon degeneration. Diagnostic features as well as both operative and non-operative treatments are evaluated from a clinical perspective, providing up to date information for clinicians and sports medicine therapists dealing with hamstring problems. Level of evidence: V. PMID:25878983

  8. Interactive orbital proximity operations planning system instruction and training guide

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1994-01-01

    This guide instructs users in the operation of a Proximity Operations Planning System. This system uses an interactive graphical method for planning fuel-efficient rendezvous trajectories in the multi-spacecraft environment of the space station and allows the operator to compose a multi-burn transfer trajectory between orbit initial chaser and target trajectories. The available task time (window) of the mission is predetermined and the maneuver is subject to various operational constraints, such as departure, arrival, spatial, plume impingement, and en route passage constraints. The maneuvers are described in terms of the relative motion experienced in a space station centered coordinate system. Both in-orbital plane as well as out-of-orbital plane maneuvering is considered. A number of visual optimization aids are used for assisting the operator in reaching fuel-efficient solutions. These optimization aids are based on the Primer Vector theory. The visual feedback of trajectory shapes, operational constraints, and optimization functions, provided by user-transparent and continuously active background computations, allows the operator to make fast, iterative design changes that rapidly converge to fuel-efficient solutions. The planning tool is an example of operator-assisted optimization of nonlinear cost functions.

  9. Multisensory simultaneity judgment and proximity to the body

    PubMed Central

    Noel, Jean-Paul; Łukowska, Marta; Wallace, Mark; Serino, Andrea

    2016-01-01

    The integration of information across different sensory modalities is known to be dependent upon the statistical characteristics of the stimuli to be combined. For example, the spatial and temporal proximity of stimuli are important determinants with stimuli that are close in space and time being more likely to be bound. These multisensory interactions occur not only for singular points in space/time, but over “windows” of space and time that likely relate to the ecological statistics of real-world stimuli. Relatedly, human psychophysical work has demonstrated that individuals are highly prone to judge multisensory stimuli as co-occurring over a wide range of time—a so-called simultaneity window (SW). Similarly, there exists a spatial representation of peripersonal space (PPS) surrounding the body in which stimuli related to the body and to external events occurring near the body are highly likely to be jointly processed. In the current study, we sought to examine the interaction between these temporal and spatial dimensions of multisensory representation by measuring the SW for audiovisual stimuli through proximal–distal space (i.e., PPS and extrapersonal space). Results demonstrate that the audiovisual SWs within PPS are larger than outside PPS. In addition, we suggest that this effect is likely due to an automatic and additional computation of these multisensory events in a body-centered reference frame. We discuss the current findings in terms of the spatiotemporal constraints of multisensory interactions and the implication of distinct reference frames on this process. PMID:26891828

  10. Surface magnetism and proximity effects in hexaboride thin films

    NASA Astrophysics Data System (ADS)

    Cen, Cheng; Ma, Yanjun; Wang, Qiang; Eom, Chang-Beom

    2017-03-01

    The unexpected ferromagnetism in alkaline hexaborides has attracted extensive research efforts. The exceptionally high Curie temperature sustained by very low density of magnetic moments is yet to be clearly understood. Here, we report the magnetic properties studied in CaB6 and SrB6 thin films and their heterostructures with SmB6 grown by pulsed laser deposition. A coexistence of ferromagnetic and superparamagnetic orders with 2D-type magnetic anisotropy was observed in CaB6 and SrB6. Boron deficiency and closely correlated local oxidization were found at the film surface that contacts air and its interface with the oxide substrate. These results suggest that the magnetism observed is likely generated by two thin surface/interface layers with high concentration of boron vacancies which are energetically stabled by oxygen cation. Additionally, clear suppression of the superconductivity proximity effect in SmB6 film was observed when SmB6 was grown on top of the magnetic CaB6. Such results demonstrate the interesting perspective of engineering multifunctional heterostructures by coupling the surface magnetic layer with the diversity of other hexaboride materials.

  11. Discerning the role of mechanosensors in regulating proximal tubule function.

    PubMed

    Raghavan, Venkatesan; Weisz, Ora A

    2016-01-01

    All cells in the body experience external mechanical forces such as shear stress and stretch. These forces are sensed by specialized structures in the cell known as mechanosensors. Cells lining the proximal tubule (PT) of the kidney are continuously exposed to variations in flow rates of the glomerular ultrafiltrate, which manifest as changes in axial shear stress and radial stretch. Studies suggest that these cells respond acutely to variations in flow by modulating their ion transport and endocytic functions to maintain glomerulotubular balance. Conceptually, changes in the axial shear stress in the PT could be sensed by three known structures, namely, the microvilli, the glycocalyx, and primary cilia. The orthogonal component of the force produced by flow exhibits as radial stretch and can cause expansion of the tubule. Forces of stretch are transduced by integrins, by stretch-activated channels, and by cell-cell contacts. This review summarizes our current understanding of flow sensing in PT epithelia, discusses challenges in dissecting the role of individual flow sensors in the mechanosensitive responses, and identifies potential areas of opportunity for new study.

  12. Proximity enhanced quantum spin Hall state in graphene

    DOE PAGES

    Kou, Liangzhi; Hu, Feiming; Yan, Binghai; ...

    2015-02-23

    Graphene is the first model system of two-dimensional topological insulator (TI), also known as quantum spin Hall (QSH) insulator. The QSH effect in graphene, however, has eluded direct experimental detection because of its extremely small energy gap due to the weak spin–orbit coupling. Here we predict by ab initio calculations a giant (three orders of magnitude) proximity induced enhancement of the TI energy gap in the graphene layer that is sandwiched between thin slabs of Sb2Te3 (or MoTe2). This gap (1.5 meV) is accessible by existing experimental techniques, and it can be further enhanced by tuning the interlayer distance viamore » compression. We reveal by a tight-binding study that the QSH state in graphene is driven by the Kane–Mele interaction in competition with Kekulé deformation and symmetry breaking. As a result, the present work identifies a new family of graphene-based TIs with an observable and controllable bulk energy gap in the graphene layer, thus opening a new avenue for direct verification and exploration of the long-sought QSH effect in graphene.« less

  13. Proximity enhanced quantum spin Hall state in graphene

    SciTech Connect

    Kou, Liangzhi; Hu, Feiming; Yan, Binghai; Wehling, Tim; Felser, Claudia; Frauenheim, Thomas; Chen, Changfeng

    2015-02-23

    Graphene is the first model system of two-dimensional topological insulator (TI), also known as quantum spin Hall (QSH) insulator. The QSH effect in graphene, however, has eluded direct experimental detection because of its extremely small energy gap due to the weak spin–orbit coupling. Here we predict by ab initio calculations a giant (three orders of magnitude) proximity induced enhancement of the TI energy gap in the graphene layer that is sandwiched between thin slabs of Sb2Te3 (or MoTe2). This gap (1.5 meV) is accessible by existing experimental techniques, and it can be further enhanced by tuning the interlayer distance via compression. We reveal by a tight-binding study that the QSH state in graphene is driven by the Kane–Mele interaction in competition with Kekulé deformation and symmetry breaking. As a result, the present work identifies a new family of graphene-based TIs with an observable and controllable bulk energy gap in the graphene layer, thus opening a new avenue for direct verification and exploration of the long-sought QSH effect in graphene.

  14. Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet

    SciTech Connect

    Banerjee, A.; Bridges, C. A.; Yan, J. -Q.; Aczel, A. A.; Li, L.; Stone, M. B.; Granroth, G. E.; Lumsden, M. D.; Yiu, Y.; Knolle, J.; Bhattacharjee, S.; Kovrizhin, D. L.; Moessner, R.; Tennant, D. A.; Mandrus, D. G.; Nagler, S. E.

    2016-04-04

    Quantum spin liquids (QSLs) are topological states of matter exhibiting remarkable properties such as the capacity to protect quantum information from decoherence. While their featureless ground states have precluded their straightforward experimental identification, excited states are more revealing and particularly interesting due to the emergence of fundamentally new excitations such as Majorana Fermions. Ideal probes of these excitations are inelastic neutron scattering experiments. We report these here for a ruthenium-based material α-RuCl3, continuing a major search (so far concentrated on iridium materials inimical to neutron probes) for realizations of the celebrated Kitaev honeycomb topological QSL. Our measurements confirm the requisite strong spin-orbit coupling and low-temperature magnetic order matching predictions proximate to the QSL. We find stacking faults, inherent to the highly 2D nature of the material, resolve an outstanding puzzle. Crucially, dynamical response measurements above interlayer energy scales are naturally accounted for in terms of deconfinement physics expected for QSLs. Comparing these with recent dynamical calculations involving gauge flux excitations and Majorana fermions of the pure Kitaev model, we propose the excitation spectrum of α-RuCl3 as prime candidate for realization of fractionalized Kitaev physics.

  15. Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet

    DOE PAGES

    Banerjee, A.; Bridges, C. A.; Yan, J. -Q.; ...

    2016-04-04

    Quantum spin liquids (QSLs) are topological states of matter exhibiting remarkable properties such as the capacity to protect quantum information from decoherence. While their featureless ground states have precluded their straightforward experimental identification, excited states are more revealing and particularly interesting due to the emergence of fundamentally new excitations such as Majorana Fermions. Ideal probes of these excitations are inelastic neutron scattering experiments. We report these here for a ruthenium-based material α-RuCl3, continuing a major search (so far concentrated on iridium materials inimical to neutron probes) for realizations of the celebrated Kitaev honeycomb topological QSL. Our measurements confirm the requisitemore » strong spin-orbit coupling and low-temperature magnetic order matching predictions proximate to the QSL. We find stacking faults, inherent to the highly 2D nature of the material, resolve an outstanding puzzle. Crucially, dynamical response measurements above interlayer energy scales are naturally accounted for in terms of deconfinement physics expected for QSLs. Comparing these with recent dynamical calculations involving gauge flux excitations and Majorana fermions of the pure Kitaev model, we propose the excitation spectrum of α-RuCl3 as prime candidate for realization of fractionalized Kitaev physics.« less

  16. Proximity graphs based multi-scale image segmentation

    SciTech Connect

    Skurikhin, Alexei N

    2008-01-01

    We present a novel multi-scale image segmentation approach based on irregular triangular and polygonal tessellations produced by proximity graphs. Our approach consists of two separate stages: polygonal seeds generation followed by an iterative bottom-up polygon agglomeration into larger chunks. We employ constrained Delaunay triangulation combined with the principles known from the visual perception to extract an initial ,irregular polygonal tessellation of the image. These initial polygons are built upon a triangular mesh composed of irregular sized triangles and their shapes are ad'apted to the image content. We then represent the image as a graph with vertices corresponding to the polygons and edges reflecting polygon relations. The segmentation problem is then formulated as Minimum Spanning Tree extraction. We build a successive fine-to-coarse hierarchy of irregular polygonal grids by an iterative graph contraction constructing Minimum Spanning Tree. The contraction uses local information and merges the polygons bottom-up based on local region-and edge-based characteristics.

  17. Sex Differences in Proximal Control of the Knee Joint

    PubMed Central

    Mendiguchia, Jurdan; Ford, Kevin R.; Quatman, Carmen E.; Alentorn-Geli, Eduard; Hewett, Timothy E.

    2014-01-01

    Following the onset of maturation, female athletes have a significantly higher risk for anterior cruciate ligament (ACL) injury compared with male athletes. While multiple sex differences in lower-extremity neuromuscular control and biomechanics have been identified as potential risk factors for ACL injury in females, the majority of these studies have focused specifically on the knee joint. However, increasing evidence in the literature indicates that lumbopelvic (core) control may have a large effect on knee-joint control and injury risk. This review examines the published evidence on the contributions of the trunk and hip to knee-joint control. Specifically, the sex differences in potential proximal controllers of the knee as risk factors for ACL injury are identified and discussed. Sex differences in trunk and hip biomechanics have been identified in all planes of motion (sagittal, coronal and transverse). Essentially, female athletes show greater lateral trunk displacement, altered trunk and hip flexion angles, greater ranges of trunk motion, and increased hip adduction and internal rotation during sport manoeuvres, compared with their male counterparts. These differences may increase the risk of ACL injury among female athletes. Prevention programmes targeted towards trunk and hip neuromuscular control may decrease the risk for ACL injuries. PMID:21688868

  18. Autogenic heterotopic vascularized proximal interphalangeal joint transplantation in children.

    PubMed

    Chiu, David T W; Lee, Jonathan

    2011-03-01

    The proximal interphalangeal joint (PIP) joint is the most crucial joint for the functionality of a finger. For a child with complex injury of the hand every effort should be exercised to maximize function restoration. If the PIP joint is irreparably damaged, its reconstruction is indicated. The technique of autogenic heterotopic vascularized toe joint transplantation provides unique advantage of a composite transfer of skin, tendons, bone and joint alone with growth plate and its efficacy has been affirmed in children. It has been suggested that such transfers require intact flexor tendon to achieve satisfactory results, our experience however indicates quite the contrary. As evidenced by this report of a 7-year-old boy with abrasion and avulsion injury to his dominant right hand resulting in a complex defect with skin lose, extensor, flexor avulsion along with cominution of the PIP joint of his long finger. A surgical formulation of staged reconstruction scheme including an autogenic heterotopic vascularized toe joint transplantation led to complete functional restoration to his right hand.

  19. Propensity score and proximity matching using random forest.

    PubMed

    Zhao, Peng; Su, Xiaogang; Ge, Tingting; Fan, Juanjuan

    2016-03-01

    In order to derive unbiased inference from observational data, matching methods are often applied to produce balanced treatment and control groups in terms of all background variables. Propensity score has been a key component in this research area. However, propensity score based matching methods in the literature have several limitations, such as model mis-specifications, categorical variables with more than two levels, difficulties in handling missing data, and nonlinear relationships. Random forest, averaging outcomes from many decision trees, is nonparametric in nature, straightforward to use, and capable of solving these issues. More importantly, the precision afforded by random forest (Caruana et al., 2008) may provide us with a more accurate and less model dependent estimate of the propensity score. In addition, the proximity matrix, a by-product of the random forest, may naturally serve as a distance measure between observations that can be used in matching. The proposed random forest based matching methods are applied to data from the National Health and Nutrition Examination Survey (NHANES). Our results show that the proposed methods can produce well balanced treatment and control groups. An illustration is also provided that the methods can effectively deal with missing data in covariates.

  20. A Review of Management Options for Proximal Humeral Fractures

    PubMed Central

    Jordan, Robert W; Modi, Chetan S

    2014-01-01

    Proximal humeral fractures are common and although the majority can be managed non-operatively, the optimal treatment of displaced or complex fractures remains controversial. Non-operative treatment is typically selected for minimally displaced fractures where union rates are high and good or excellent outcomes can be expected in approximately 80% of cases. The aims of surgical fixation are to restore articular surface congruency, alignment and the relationship between the tuberosities and the humeral head. Hemiarthroplasty provides patients with reliable pain relief and its indications include fracture dislocations, humeral head splitting fractures and some three- and four- part fractures. The key areas of surgical technique that influence functional outcome include correctly restoring the humeral height, humeral version and tuberosity position. Function, however, is poor if the tuberosities either fail to unite or mal-unite. The interest in reverse shoulder arthroplasty as an alternative option has therefore recently increased, particularly in older patients with poor bone quality and tuberosity comminution. The evidence supporting this, however, is currently limited to multiple case series with higher level studies currently underway. PMID:25067968

  1. Spatial Instabilities, Homogeneities and Proximity Effects: Highly Correlated Metals

    SciTech Connect

    Dynes, Robert C.

    2008-10-31

    We have developed a superconducting scanning tunneling microscope (S-STM) which is a direct and local probe of the pair wave function of superconducting materials via the Josephson effect and quasiparticle spectra via scanning tunneling spectroscopy (STS). The novel feature of this device is a superconducting tip (Pb with an Ag capping layer) in close proximity to a superconducting sample to form a superconductor-insulator-superconductor (SIS) tunnel junction. The operation of this S-STM has been verified in the observation of Josephson tunneling between the tip and different sample systems including Pb films and NbSe{sub 2}. This instrument was employed in the study of High T{sub c} superconductors and spatial inhomogeneities. The major accomplishments in the current grant period are observations of c-axis Josephson tunneling between a conventional superconductor (Pb) and variously doped BSSCO samples. These observations are reported: (1) C-axis Josephson couplings between Pb and both OP and OV-BSCCO. This is surprising if BSCCO is strictly a d-wave superconductor; (2) ICRN of the OP sample seemed to be much smaller than those of OV samples; (3) ICRN inhomogeneity is correlated with the gap inhomogeneity on the length scale of ξ in the OV samples; (4) Inverse correlation between ICRN and Δ in OV samples; (5) Degradations of the superconductivity of BSCCO by high current density.

  2. [Kapandji intramedullary wire osteosynthesis in proximal humeral fractures].

    PubMed

    Werner, A; Böhm, D; Ilg, A; Gohlke, F

    2002-04-01

    For operative treatment of proximal humeral fractures minimal invasive techniques reduce the risk of iatrogenic damage of blood supply and periarticular scarring. Reported preliminary results are encouraging. We present our experience achieved with an intramedullary wire fixation adapted from a report of Kapandji in 1989. Between 3/95 and 6/00 29 patients were treated with this technique at our institution. All received early functional treatment. 14 patients (average mean age 56 years at time of trauma) who had a minimum follow up of 24 months (mean 36.4 months) and therefore allowed a preliminary conclusion regarding avascular head necrosis (AVN) were reexamined by use of the Constant Score and x-ray. We examined three unstable 2-part, four 3-part and seven 4-part fractures (5 of them valgus-impacted). The mean Constant Score at follow up was 70 points (31-86 points). We saw one total collapse of the humeral head because of AVN. In one patient the distal end of the wires led to a skin irritation and had to be shortened. We observed no secondary fragment displacement or non-unions. In our hands, this technique offers good results, even in valgus-impacted 4-part fractures of the elderly and allows internal fixation in little displaced but unstable fractures with the benefit of early functional treatment instead of longer immobilization. Based on the experience with intramedullary wiring the previously performed technique using threading wires was abandoned and the indication for primary arthroplasty considerably influenced.

  3. Proximal hypospadias: we aren’t always keeping our promises

    PubMed Central

    Long, Christopher J.; Canning, Douglas A.

    2016-01-01

    Hypospadias surgery is a humbling art form. The evolution of surgical techniques has made distal hypospadias outcomes favorable, but recent publications suggest that our complication rates for proximal hypospadias are much higher than previously reported. To explain these shortcomings, we examine the literature and focus on the lack of standardized documentation, the subsequent inability to objectify the severity of the phenotype, and the underestimation of complications due to lack of long-term follow up. The variability in surgical technique and the fact that the literature abounds with small case series from single institutions also limits our ability to compare outcomes. We believe that the use of standardized and scored phenotype assessments from diagnosis through the extended postoperative period will allow for improved scientific assessment of outcomes. This will facilitate multi-institution collaboration and tabulation of outcomes, allowing rapid data accumulation and assessment for this rare disorder. As surgeons, we must follow boys through puberty into adulthood and must honestly report our results in order to advance our surgical approach to this complicated problem. PMID:27746897

  4. Frustrated proximity effects between s and s± superconductors

    NASA Astrophysics Data System (ADS)

    Stanev, Valentin; Koshelev, Alexei E.

    2011-03-01

    The nature of the superconducting order parameter (OP) in iron pnictides and chalcogenides is a hotly debated issue. It was theoretically proposed that the OP has opposite signs on the hole and the electron bands, i.e., it belongs to the unconventional class of s +/- (or extended s)-wave. There are, however, very few experiments that can directly distinguish this state from the ordinary s-wave OP. One way to address this problem is to study the proximity effects in a sandwich composed of conventional and iron pnictide superconductors (SC). If the pnictides indeed have the s +/- OP this system is intrinsically frustrated. In the case of strong frustration, a time-reversal symmetry-breaking (TRSB) SC state emerges, in which the OP phases in different bands are tilted at an angle, different from π , and controlled by the coupling strength. Observation of such state in the iron-based SC materials would give definite evidence for the s +/- OP. We present a microscopic, fully self-consistent approach to this problem, based on Usadel equations. We have studied the conditions for existence of the TRSB state and its experimental signatures.

  5. Fatty Acid and Proximate Composition of Bee Bread

    PubMed Central

    Kaplan, Muammer; Karaoglu, Öznur; Eroglu, Nazife

    2016-01-01

    Summary Palynological spectrum, proximate and fatty acid (FA) composition of eight bee bread samples of different botanical origins were examined and significant variations were observed. The samples were all identified as monofloral, namely Castanea sativa (94.4%), Trifolium spp. (85.6%), Gossypium hirsutum (66.2%), Citrus spp. (61.4%) and Helianthus annuus (45.4%). Each had moisture content between 11.4 and 15.9%, ash between 1.9 and 2.54%, fat between 5.9 and 11.5%, and protein between 14.8 and 24.3%. A total of 37 FAs were determined with most abundant being (9Z,12Z,15Z)-octadeca-9,12,15-trienoic, (9Z,12Z)- -octadeca-9,12-dienoic, hexadecanoic, (Z)-octadec-9-enoic, (Z)-icos-11-enoic and octadecanoic acids. Among all, cotton bee bread contained the highest level of ω-3 FAs, i.e. 41.3%. Unsaturated to saturated FA ratio ranged between 1.38 and 2.39, indicating that the bee bread can be a good source of unsaturated FAs. PMID:28115909

  6. Nebivolol Attenuates Maladaptive Proximal Tubule Remodeling in Transgenic Rats

    PubMed Central

    Hayden, Melvin R.; Habibi, Javad; Whaley-Connell, Adam; Sowers, Dilek; Johnson, Megan; Tilmon, Roger; Jain, Deepika; Ferrario, Carlos; Sowers, James R.

    2010-01-01

    Background/Aims The impact of nebivolol therapy on the renal proximal tubular cell (PTC) structure and function was investigated in a transgenic (TG) rodent model of hypertension and the cardiometabolic syndrome. The TG Ren2 rat develops nephropathy with proteinuria, increased renal angiotensin II levels and oxidative stress, and PTC remodeling. Nebivolol, a β1-antagonist, has recently been shown to reduce albuminuria, in part, through reductions in renal oxidative stress. Accordingly, we hypothesized that nebivolol therapy would attenuate PTC damage and tubulointerstitial fibrosis. Methods Young Ren2 (R2-N) and SD (SD-N) rats were treated with nebivolol (10 mg/kg/day) or vehicle (R2-C; SD-C) for 3 weeks. PTC structure and function were tested using transmission electron microscopy and functional measurements. Results Nebivolol treatment decreased urinary N-acetyl-β-D-glucosaminidase, tubulointerstitial ultrastructural remodeling and fibrosis, NADPH oxidase activity, 3-nitrotyrosine levels, and increased megalin and lysosomal-associated membrane protein-2 immunostaining in PTCs. Ultrastructural abnormalities that were improved with therapy included altered canalicular structure, reduced endosomes/lysosomes and PTC vacuoles, basement membrane thickening, and mitochondrial remodeling/fragmentation. Conclusion These observations support the notion that nebivolol may improve PTC reabsorption of albumin and other glomerular filtered small molecular weight proteins in association with the attenuation of oxidative stress, tubulointerstitial injury and fibrosis in this rat model of metabolic kidney disease. PMID:20110666

  7. Endoprosthetic proximal femur replacement: metastatic versus primary tumors.

    PubMed

    Potter, Benjamin K; Chow, Vincent E; Adams, Sheila C; Letson, G Douglas; Temple, H Thomas

    2009-12-01

    Few studies have examined the impact of underlying diagnosis on the functional and oncologic outcomes following endoprosthetic proximal femur replacement (PFR). We performed a retrospective review of 61 consecutive cemented bipolar PFR in 59 patients for treatment neoplastic lesions with a minimum follow-up of 24 months. Twenty-two patients had primary bone tumors and 39 had metastatic disease. Average follow-up for the 30 surviving patients was 55.4 months and the mean postoperative survival for the 29 patients who died was 12.2 months. Patients with primary tumors demonstrated significantly better functional outcomes than those with metastatic disease, with mean Musculoskeletal Tumor Society functional scores of 80.2 and 66.8%, respectively (p=0.0002). Age correlated inversely with functional scores (r=-0.48; p=0.0002), while femoral resection length did not. Preoperative pathologic fracture did not appear to adversely impact final functional outcomes. The Kaplan-Meier 5-year implant survival estimate was 92.5%, with aseptic loosening as the endpoint. Both functional results and survival are increased for primary tumors versus metastatic disease following PFR. However, PFR results in excellent local disease control, reliable pain relief and good functional results in both groups, with prosthesis survival exceeding that of the patient in many cases.

  8. Predicting Performance in Higher Education Using Proximal Predictors

    PubMed Central

    Niessen, A. Susan M.; Meijer, Rob R.; Tendeiro, Jorge N.

    2016-01-01

    We studied the validity of two methods for predicting academic performance and student-program fit that were proximal to important study criteria. Applicants to an undergraduate psychology program participated in a selection procedure containing a trial-studying test based on a work sample approach, and specific skills tests in English and math. Test scores were used to predict academic achievement and progress after the first year, achievement in specific course types, enrollment, and dropout after the first year. All tests showed positive significant correlations with the criteria. The trial-studying test was consistently the best predictor in the admission procedure. We found no significant differences between the predictive validity of the trial-studying test and prior educational performance, and substantial shared explained variance between the two predictors. Only applicants with lower trial-studying scores were significantly less likely to enroll in the program. In conclusion, the trial-studying test yielded predictive validities similar to that of prior educational performance and possibly enabled self-selection. In admissions aimed at student-program fit, or in admissions in which past educational performance is difficult to use, a trial-studying test is a good instrument to predict academic performance. PMID:27073859

  9. Proximal ureteral ectopia causing hydronephrosis in a kitten.

    PubMed

    D'Ippolito, Paola; Nicoli, Stefano; Zatelli, Andrea

    2006-12-01

    A 2-month-old, female cat was presented for abdomen dilation. The patient was undernourished, and severe left hydronephrosis was diagnosed after clinical, ultrasonographical and radiographical examination. Although pyelography was performed in order to visualise the ureteral course, surgery was necessary to reach a final aetiological diagnosis and treatment. At gross examination, the left ureter crossed the renal capsula at the level of the caudal renal pole, and the subcapsular ureteral segment was markedly dilated. Distal to the renal capsula, the left ureter was very thin when compared to the right. The parenchyma of the left kidney, as suggested by ultrasonographical evaluation, was extremely reduced in thickness. An ureteronephrectomy was performed. Histopathological evaluation revealed glomerular sclerosis and diffuse parenchymal fibrosis. Severe hydronephrosis derived from an altered renal pelvic anatomy and abnormal ureteral course determining functional stenosis. Diagnosis of congenital anomaly before development of complications such as hydronephrosis could have allowed a surgical renal capsulectomy and obstruction relief. To the author's knowledge, this is the first report of severe hydronephrosis associated to altered renal pelvic anatomy and proximal ureteral ectopia in cat.

  10. Megalin and cubilin: synergistic endocytic receptors in renal proximal tubule.

    PubMed

    Christensen, E I; Birn, H

    2001-04-01

    The multiligand, endocytic receptors megalin and cubilin are colocalized in the renal proximal tubule. They are heavily expressed in the apical endocytic apparatus. Megalin is a 600-kDa transmembrane protein belonging to the low-density lipoprotein-receptor family. The cytoplasmic tail contains three NPXY motifs that mediate the clustering in coated pits and are possibly involved in signaling functions. Cubilin, also known as the intestinal intrinsic factor-cobalamin receptor, is a 460-kDa receptor with no transmembrane domain and no known signal for endocytosis. Because the two receptors bind each other with high affinity and colocalize in several tissues, it is highly conceivable that megalin mediates internalization of cubilin and its ligands. Both receptors are important for normal tubular reabsorption of proteins, including albumin. Among the proteins normally filtered in the glomeruli, cubilin has been shown to bind albumin, immunoglobulin light chains, and apolipoprotein A-I. The variety of filtered ligands identified for megalin include vitamin-binding proteins, hormones, enzymes, apolipoprotein H, albumin, and beta(2)- and alpha(1)-microglobulin. Loss of these proteins and vitamins in the urine of megalin-deficient mice illustrates the physiological importance of this receptor.

  11. Proximity effects in cold gases of multiply charged atoms (Review)

    NASA Astrophysics Data System (ADS)

    Chikina, I.; Shikin, V.

    2016-07-01

    Possible proximity effects in gases of cold, multiply charged atoms are discussed. Here we deal with rarefied gases with densities nd of multiply charged (Z ≫ 1) atoms at low temperatures in the well-known Thomas-Fermi (TF) approximation, which can be used to evaluate the statistical properties of single atoms. In order to retain the advantages of the TF formalism, which is successful for symmetric problems, the external boundary conditions accounting for the finiteness of the density of atoms (donors), nd ≠ 0, are also symmetrized (using a spherical Wigner-Seitz cell) and formulated in a standard way that conserves the total charge within the cell. The model shows that at zero temperature in a rarefied gas of multiply charged atoms there is an effective long-range interaction Eproxi(nd), the sign of which depends on the properties of the outer shells of individual atoms. The long-range character of the interaction Eproxi is evaluated by comparing it with the properties of the well-known London dispersive attraction ELond(nd) < 0, which is regarded as a long-range interaction in gases. For the noble gases argon, krypton, and xenon Eproxi>0 and for the alkali and alkaline-earth elements Eproxi < 0. At finite temperatures, TF statistics manifests a new, anomalously large proximity effect, which reflects the tendency of electrons localized at Coulomb centers to escape into the continuum spectrum. The properties of thermal decay are interesting in themselves as they determine the important phenomenon of dissociation of neutral complexes into charged fragments. This phenomenon appears consistently in the TF theory through the temperature dependence of the different versions of Eproxi. The anomaly in the thermal proximity effect shows up in the following way: for T ≠ 0 there is no equilibrium solution of TS statistics for single multiply charged atoms in a vacuum when the effect is present. Instability is suppressed in a Wigner-Seitz model under the assumption that

  12. Proximal femoral epiphysiolysis during reduction of hip dislocation in adolescents.

    PubMed

    Herrera-Soto, Jose Antonio; Price, Charles T; Reuss, Bryan L; Riley, Patrick; Kasser, James R; Beaty, James H

    2006-01-01

    Traumatic hip dislocation is an uncommon injury in children. The urgency of closed reduction to prevent possible osteonecrosis may present some pitfalls. Adolescents with open proximal femoral physis may have sustained trauma to the physis at the time of dislocation that can lead to displacement of the epiphysis during the reduction maneuver. The purpose of this study is to report 5 cases with this complication and discuss potential etiology and management. All of the 5 patients were between 12 and 16 years old and underwent closed reduction under conscious sedation. Epiphysiolysis of the femoral head was diagnosed after reduction in all 5 patients. Every patient underwent emergent open reduction and internal fixation of the femur and open hip reduction. Avascular necrosis was identified in all 5 patients within 3 to 15 months postinjury. If there is any suspicion of associated physeal injury or if there is any physeal instability noted under fluoroscopy, an open reduction is recommended in the operating room under radiograph guidance to prevent displacement.

  13. Proximate bases of silver color in anhinga (Anhinga anhinga) feathers.

    PubMed

    Shawkey, Matthew D; Maia, Rafael; D'Alba, Liliana

    2011-11-01

    Colors of living organisms are produced by selective light absorption from pigments and/or by light scattering from highly ordered nanostructures (i.e., structural color). While the physical bases of metallic colors of arthropods and fish are fairly well-known, those of birds are not. Here we examine structurally based silver color and its production in feathers of the waterbird species Anhinga. This achromatic color is distinguished from grey by high specular reflectance, from white by low diffuse reflectance, and from both by high gloss. Light and electron microscopy revealed three modifications of feathers likely leading to silver color. First, proximal barbules were highly elongated and contained glossy black color at their base and white color at their pennulum. Second, this glossy black portion contained a single outer layer of keratin weakly bounded by melanosomes. Finally, the white portion contained a disordered amorphous matrix of keratin and air. Optical analyzes suggest that these structures produce, respectively, glossy black color through thin-film interference and white color through incoherent light scattering. Silver color likely results from the combined reflectance of these adjacent structures. This represents a distinct mechanism for attaining silver colors that may have been partially derived through selection for display, thermoregulation or decreased hydrophobicity.

  14. Sex Differences in Renal Proximal Tubular Cell Homeostasis.

    PubMed

    Seppi, Thomas; Prajczer, Sinikka; Dörler, Maria-Magdalena; Eiter, Oliver; Hekl, Daniel; Nevinny-Stickel, Meinhard; Skvortsova, Iraida; Gstraunthaler, Gerhard; Lukas, Peter; Lechner, Judith

    2016-10-01

    Studies in human patients and animals have revealed sex-specific differences in susceptibility to renal diseases. Because actions of female sex hormones on normal renal tissue might protect against damage, we searched for potential influences of the female hormone cycle on basic renal functions by studying excretion of urinary marker proteins in healthy human probands. We collected second morning spot urine samples of unmedicated naturally ovulating women, postmenopausal women, and men daily and determined urinary excretion of the renal tubular enzymes fructose-1,6-bisphosphatase and glutathione-S-transferase-α Additionally, we quantified urinary excretion of blood plasma proteins α1-microglobulin, albumin, and IgG. Naturally cycling women showed prominent peaks in the temporal pattern of urinary fructose-1,6-bisphosphatase and glutathione-S-transferase-α release exclusively within 7 days after ovulation or onset of menses. In contrast, postmenopausal women and men showed consistently low levels of urinary fructose-1,6-bisphosphatase excretion over comparable periods. We did not detect changes in urinary α1-microglobulin, albumin, or IgG excretion. Results of this study indicate that proximal tubular tissue architecture, representing a nonreproductive organ-derived epithelium, undergoes periodical adaptations phased by the female reproductive hormone cycle. The temporally delimited higher rate of enzymuria in ovulating women might be a sign of recurring increases of tubular cell turnover that potentially provide enhanced repair capacity and thus, higher resistance to renal damage.

  15. Proximity and Visibility of Fruits and Vegetables Influence Intake in a Kitchen Setting among College Students

    ERIC Educational Resources Information Center

    Privitera, Gregory J.; Creary, Heather E.

    2013-01-01

    The hypothesis that participants will eat more fruits (apple slices) and vegetables (carrot cuts) if they are made more proximate and visible was tested using a 2 × 2 between-participants design. Proximity was manipulated by placing fruits and vegetables in a bowl at a table where participants sat (near) or 2 m from the table (far). Visibility was…

  16. Wall proximity corrections for hot-wire readings in turbulent flows

    NASA Technical Reports Server (NTRS)

    Hebbar, K. S.

    1980-01-01

    This note describes some details of recent (successful) attempts of wall proximity corrections for hot-wire measurements performed in a three-dimensional incompressible turbulent boundary layer. A simple and quite satisfactory method of estimating wall proximity effects on hot-wire readings is suggested.

  17. 14 CFR 91.143 - Flight limitation in the proximity of space flight operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Flight Rules General § 91.143 Flight limitation in the proximity of space flight operations....

  18. 14 CFR 91.143 - Flight limitation in the proximity of space flight operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Flight Rules General § 91.143 Flight limitation in the proximity of space flight operations....

  19. 14 CFR 91.143 - Flight limitation in the proximity of space flight operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Flight Rules General § 91.143 Flight limitation in the proximity of space flight operations....

  20. 14 CFR 91.143 - Flight limitation in the proximity of space flight operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Flight Rules General § 91.143 Flight limitation in the proximity of space flight operations....

  1. 14 CFR 91.143 - Flight limitation in the proximity of space flight operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Flight Rules General § 91.143 Flight limitation in the proximity of space flight operations....

  2. A Feasibility Study of 50 nm Resolution with Low Energy Electron Beam Proximity Projection Lithography

    NASA Astrophysics Data System (ADS)

    Yoshizawa, Masaki; Savas, T. A.

    2002-01-01

    Patterns of 50 nm lines and spaces were demonstrated by low energy electron beam proximity lithography using 47-nm-thick poly methyl methacrylate (PMMA) and stencil masks fabricated by achromatic interference lithography (AIL). The result indicates the validity of the resolution analysis previously reported and the resolution capabilities of low energy electron beam proximity projection lithography (LEEPL) as a 50 nm node technology.

  3. Maintaining Interaction at the Zone of Proximal Development through Reflexive Practice and Action Research

    ERIC Educational Resources Information Center

    Lisle, Angela

    2006-01-01

    In this study, dialectical reflexive practice is used to maintain student-teacher interactions in the zone of proximal development. The zone of proximal development is the development-and-learning unit of the child or learner and the author suggests that it is also the fusion point of Marx's dialectical historical materialism: the creation of…

  4. Autoradiographic Localization of [3H]Gentamicin in the Proximal Renal Tubules of Mice

    PubMed Central

    Kuhar, Michael J.; Mak, Linda L.; Lietman, Paul S.

    1979-01-01

    The site of localization of [3H]gentamicin within mouse kidney is shown to be the proximal renal tubule by coincidence of the radioactivity, as visualized by autoradiography, and the mucopolysaccharide-rich microvilli characteristic of proximal convoluted tubules, as visualized by histochemical staining. Images PMID:426500

  5. Ganglion cysts of the proximal tibiofibular joint review of literature with three case reports.

    PubMed

    Vatansever, A; Bal, E; Okcu, G

    2006-11-01

    Proximal tibiofibular ganglion is a rare disorder. It may settle down in the subcutaneous tissue or may develop along the peroneal muscles and nerve. Common clinical findings are various sizes of mass, pain and hypoesthesis due to compression neuropathy. We report three cases of proximal tibiofibular ganglion and review the literature about the diagnostic tools, recurrence rates and treatment modalities.

  6. Fracture of the proximal humerus with disruption of the tendon of the pectoralis major

    PubMed Central

    Berghs, Bart M.; Tongel, Alexander Van; Bo, Thomas De; De Wilde, Lieven F.

    2016-01-01

    Combined pectoralis major disruption and proximal humeral fractures are uncommon. A simple radiologic diagnostic tool which consists of the measurement of the displacement from the humeral shaft to the lateral side of the humeral head (lateral to the outer proximal cortex) can help to diagnose this combined lesion. PMID:26980990

  7. The Na/K-ATPase-mediated signal transduction as a target for new drug development.

    PubMed

    Xie, Zijian; Xie, Joe

    2005-09-01

    The Na/K-ATPase, or Na+ pump, is a member of the P-type ATPase superfamily. In addition to pumping ions, the Na/K-ATPase is a receptor that not only regulates the function of protein kinases, but also acts as a scaffold, capable of tethering different proteins into a signalplex. The signaling Na/K-ATPase resides in caveolae and forms a "binary receptor" with the tyrosine kinase Src. Endogenous cardiotonic steroids and digitalis drugs such as ouabain act as agonists and provoke this binary receptor, resulting in tyrosine phosphorylation of the proteins that are either associated with, or in close proximity to, the signaling Na/K-ATPase. Subsequently, this initiates protein kinase cascades including ERKs and PKC isozymes. It also increases mitochondrial production of reactive oxygen species (ROS) and regulates intracellular calcium concentration. Like other receptors, activation of the Na/K-ATPase/Src by ouabain induces the endocytosis of the plasma membrane Na/K-ATPase. Significantly, this newly appreciated signaling function of the Na/K-ATPase appears to play an important role in the pathogenesis of many cardiovascular diseases, therefore serving as an important target for development of novel therapeutic agents.

  8. Estimation of 1D proximity budget impacts due to light source for advanced node design

    NASA Astrophysics Data System (ADS)

    Peng, R. C.; Wu, Tony; Liu, H. H.

    2014-03-01

    The laser impacts on the proximity error are well known in many previous studies and papers. The proximity budget control is more and more important for advanced node design. The goal of this paper is to describe the laser spectral bandwidth and wavelength stability contributions to the proximity budget by considering general line/space and trench pattern design. We performed experiments and modeled the photolithography response using Panoramic Technology HyperLith simulation over a range of laser bandwidth and wavelength stability conditions to quantify the long term and short term stability contributions on wafer-to-wafer and field-to-field proximity variation. Finally, we determine the requirements for current system performance to meet patterning requirements and minimize the laser contribution on proximity error and within 4% of target CD Critical Dimension Uniformity (CDU) budget process requirement [2]. This paper also discusses how the wafer lithography drivers are enabled by ArFi light source technologies.

  9. Understanding Proximal-Distal Economic Projections of the Benefits of Childhood Preventive Interventions

    PubMed Central

    Slade, Eric P.; Becker, Kimberly D.

    2014-01-01

    This paper discusses the steps and decisions involved in proximal-distal economic modeling, in which social, behavioral, and academic outcomes data for children may be used to inform projections of the economic consequences of interventions. Economic projections based on proximal-distal modeling techniques may be used in cost-benefit analyses when information is unavailable for certain long term outcomes data in adulthood or to build entire cost-benefit analyses. Although examples of proximal-distal economic analyses of preventive interventions exist in policy reports prepared for governmental agencies, such analyses have rarely been completed in conjunction with research trials. The modeling decisions on which these prediction models are based are often opaque to policymakers and other end-users. This paper aims to illuminate some of the key steps and considerations involved in constructing proximal-distal prediction models and to provide examples and suggestions that may help guide future proximal-distal analyses. PMID:24337979

  10. Proximal femoral replacement and allograft prosthesis composite in the treatment of periprosthetic fractures with significant proximal bone loss.

    PubMed

    Rasouli, Mohammad R; Porat, Manny D; Hozack, William J; Parvizi, Javad

    2012-11-01

    Femoral bone loss due to periprosthetic fracture, a challenging problem in total hip arthroplasty (THA), is increasingly encountered due to a rise in the number of revision THAs performed. Allograft prosthesis composite (APC) and proximal femoral replacement (PFR) are two available options for management of patients with difficult type-B3 Vancouver periprosthetic fractures. The treatment algorithm for patients with these fractures has been extensively studied and is influenced by the age and activity level of the patient. APC is often preferred in young and active patients in an attempt to preserve bone stock while older and less active patients are considered candidates for PFR. In spite of the high rate of overall complications with these two procedures, reported survivorship is acceptable. Treating patients with these complicated fractures is fraught with complications and, even with successful treatment, the outcomes are not as promising as those associated with primary hip replacement. In this paper, we aimed to review available published reports about PFR and APC for treatment of periprosthetic fractures around THAs.

  11. Risk factors associated with the occurrence of proximal humerus fractures in patients with rheumatoid arthritis: a custom strategy for preventing proximal humerus fractures.

    PubMed

    Ochi, Kensuke; Furuya, Takefumi; Ishibashi, Mina; Watanabe, Makiko; Ikari, Katsunori; Taniguchi, Atsuo; Yamanaka, Hisashi; Momohara, Shigeki

    2016-02-01

    To our knowledge, no prior report focused on the risk factors for proximal humerus fractures in patients with rheumatoid arthritis. The purpose of this study was to evaluate the association between potential risk factors and the occurrence of proximal humerus fractures in patients with rheumatoid arthritis. A total of 11,907 patients with rheumatoid arthritis were enrolled in our observational cohort rheumatoid arthritis study between 2000 and 2012. Self-reported proximal humerus fractures were verified using the patients' medical records. Cox proportional hazard models were used to analyze the independent contribution of risk factors to the occurrence of proximal humerus fractures. During follow-up (mean 5.6 years), 92 proximal humerus fractures were verified in 91 patients. Multivariate Cox regression analyses estimated that the hazard ratios of sustaining a proximal humerus fracture were 1.37 for every 10-year increase in age [95 % confidence interval (CI) 1.10-1.70; P < 0.01], 1.95 for increases in serum C-reactive protein levels (mg/100 mL; 95 % CI 1.15-3.34; P < 0.05), 2.13 for a history of fractures (95 % CI 1.34-3.40; P < 0.01), 1.07 for the daily prednisolone dose (per mg; 95 % CI 1.01-1.13; P < 0.05), and 1.97 for oral bisphosphonate use (95 % CI 1.20-3.23; P < 0.01). Better control of rheumatoid arthritis with a smaller daily prednisolone dose in elderly patients with a history of fractures may be important for preventing proximal humerus fractures.

  12. The shape of the early hominin proximal femur.

    PubMed

    Harmon, Elizabeth H

    2009-06-01

    Postcranial skeletal variation among Plio-Pleistocene hominins has implications for taxonomy and locomotor adaptation. Although sample size constraints make interspecific comparisons difficult, postcranial differences between Australopithecus afarensis and Australopithecus africanus have been reported (McHenry and Berger: J Hum Evol 35 1998 1-22; Richmond et al.: J Hum Evol 43 [2002] 529-548; Green et al.: J Hum Evol 52 2007 187-200). Additional evidence indicates that the early members of the genus Homo show morphology like recent humans (e.g., Walker and Leakey: The Nariokotome Homo erectus skeleton. Cambridge: Harvard, 1993). Using a larger fossil sample than previous studies and novel methods, the early hominin proximal femur is newly examined to determine whether new data alter the current view of femoral evolution and inform the issue of interspecific morphological variation among australopiths. Two- and three-dimensional data are collected from large samples of recent humans, Pan, Gorilla, and Pongo and original fossil femora of Australopithecus, Paranthropus, and femora of African fossil Homo. The size-adjusted shape data are analyzed using principal components, thin plate spline analysis, and canonical variate analysis to assess shape variation. The results indicate that femora of fossil Homo are most similar to modern humans but share a low neck-shaft angle (NSA) with australopiths. Australopiths as a group have ape-like greater trochanter morphology. A. afarensis differs from P. robustus and A. africanus in attributes of the neck and NSA. However, interspecific femoral variation is low and australopiths are generally morphologically similar. Although the differences are not dramatic, when considered in combination with other postcranial evidence, the adaptive differences among australopiths in craniodental morphology may have parallels in the postcranium.

  13. Augmentation of proximal femoral nail in unstable trochanteric fractures

    PubMed Central

    Gadegone, Wasudeo M.; Shivashankar, Bhaskaran; Lokhande, Vijayanad; Salphale, Yogesh

    2017-01-01

    Introduction: Biomechanically proximal femoral nail (PFN) is a better choice of implant, still it is associated with screw breakage, cut out of screw through femoral head, Z effect, reverse Z effect, and lateral migration of screws. The purpose of this study is to evaluate the results of augmented PFN in terms of prevention of postoperative complications and failure rates in unstable trochanteric fractures. Material and methods: We carried out a prospective study of 82 cases with unstable trochanteric femoral fractures from April 2010 to December 2015. Forty-two females and 40 males in the age group between 58 and 81 years were included in this study. There were 45 cases of AO 31 A2 (2.2, 2.3) and 37 cases of AO 31 A3 (3.1, 3.2, 3.3). Fractures were fixed by PFN with augmentation by an additional screw from trochanter to inferior quadrant of femoral head or cerclage wire to strengthen the lateral trochanteric wall. Results: The bone healing is observed in all the cases in the mean period of 14.2 weeks. Nine patients developed complications, including lateral migration of neck screws (n = 5), Z effect (n = 1), infection (n = 2), and breakage of distal interlocking bolt in one case. Removal of screws was required in five cases. Patients were followed up for a mean of 8.4 months. At the end of follow-up the Salvati and Wilson hip function was 32 (out of 40) in 88% of patients. Conclusion: The stabilization of lateral trochanteric wall with additional screw or cerclage wire increases the stability of construct. PMID:28186871

  14. EPSPs Measured in Proximal Dendritic Spines of Cortical Pyramidal Neurons.

    PubMed

    Acker, Corey D; Hoyos, Erika; Loew, Leslie M

    2016-01-01

    EPSPs occur when the neurotransmitter glutamate binds to postsynaptic receptors located on small pleomorphic membrane protrusions called dendritic spines. To transmit the synaptic signal, these potentials must travel through the spine neck and the dendritic tree to reach the soma. Due to their small size, the electrical behavior of spines and their ability to compartmentalize electrical signals has been very difficult to assess experimentally. In this study, we developed a method to perform simultaneous two-photon voltage-sensitive dye recording with two-photon glutamate uncaging in order to measure the characteristics (amplitude and duration) of uncaging-evoked EPSPs in single spines on the basal dendrites of L5 pyramidal neurons in acute brain slices from CD1 control mice. We were able to record uncaging-evoked spine potentials that resembled miniature EPSPs at the soma from a wide range of spine morphologies. In proximal spines, these potentials averaged 13.0 mV (range, 6.5-30.8 mV; N = 20) for an average somatic EPSP of 0.59 mV, whereas the mean attenuation ratio (spine/soma) was found to be 25.3. Durations of spine EPSP waveforms were found to be 11.7 ms on average. Modeling studies demonstrate the important role that spine neck resistance (Rneck) plays in spine EPSP amplitudes. Simulations used to estimate Rneck by fits to voltage-sensitive dye measurements produced a mean of 179 MΩ (range, 23-420 MΩ; N = 19). Independent measurements based on fluorescence recovery after photobleaching of a cytosolic dye from spines of the same population of neurons produced a mean R eck estimate of 204 MΩ (range, 52-521 MΩ; N = 34).

  15. Proximity to crops and residential to agricultural herbicides in Iowa

    USGS Publications Warehouse

    Ward, M.H.; Lubin, J.; Giglierano, J.; Colt, J.S.; Wolter, C.; Bekiroglu, N.; Camann, D.; Hartge, P.; Nuckols, J.R.

    2006-01-01

    Rural residents can be exposed to agricultural pesticides through the proximity of their homes to crop fields. Previously, we developed a method to create historical crop maps using a geographic information system. The aim of the present study was to determine whether crop maps are useful for predicting levels of crop herbicides in carpet dust samples from residences. From homes of participants in a case-control study of non-Hodgkin lymphoma in Iowa (1998-2000), we collected vacuum cleaner dust and measured 14 herbicides with high use on corn and soybeans in Iowa. Of 112 homes, 58% of residences had crops within 500 m of their home, an intermediate distance for primary drift from aerial and ground applications. Detection rates for herbicides ranged from 0% for metribuzin and cyanazine to 95% for 2,4-dichlorophenoxyacetic acid. Six herbicides used almost exclusively in agriculture were detected in 28% of homes. Detections and concentrations were highest in homes with an active farmer. Increasing acreage of corn and soybean fields within 750 m of homes was associated with significantly elevated odds of detecting agricultural herbicides compared with homes with no crops within 750 m (adjusted odds ratio per 10 acres = 1.06; 95% confidence interval, 1.02-1.11). Herbicide concentrations also increased significantly with increasing acreage within 750 m. We evaluated the distance of crop fields from the home at < 100, 101-250, 251-500, and 501-750 m. Including the crop buffer distance parameters in the model did not significantly improve the fit compared with a model with total acres within 750 m. Our results indicate that crop maps may be a useful method for estimating levels of herbicides in homes from nearby crop fields.

  16. Na+ coordination at the Na2 site of the Na+/I- symporter.

    PubMed

    Ferrandino, Giuseppe; Nicola, Juan Pablo; Sánchez, Yuly E; Echeverria, Ignacia; Liu, Yunlong; Amzel, L Mario; Carrasco, Nancy

    2016-09-13

    The sodium/iodide symporter (NIS) mediates active I(-) transport in the thyroid-the first step in thyroid hormone biosynthesis-with a 2 Na(+): 1 I(-) stoichiometry. The two Na(+) binding sites (Na1 and Na2) and the I(-) binding site interact allosterically: when Na(+) binds to a Na(+) site, the affinity of NIS for the other Na(+) and for I(-) increases significantly. In all Na(+)-dependent transporters with the same fold as NIS, the side chains of two residues, S353 and T354 (NIS numbering), were identified as the Na(+) ligands at Na2. To understand the cooperativity between the substrates, we investigated the coordination at the Na2 site. We determined that four other residues-S66, D191, Q194, and Q263-are also involved in Na(+) coordination at this site. Experiments in whole cells demonstrated that these four residues participate in transport by NIS: mutations at these positions result in proteins that, although expressed at the plasma membrane, transport little or no I(-) These residues are conserved throughout the entire SLC5 family, to which NIS belongs, suggesting that they serve a similar function in the other transporters. Our findings also suggest that the increase in affinity that each site displays when an ion binds to another site may result from changes in the dynamics of the transporter. These mechanistic insights deepen our understanding not only of NIS but also of other transporters, including many that, like NIS, are of great medical relevance.

  17. Distinct afferent innervation patterns within the human proximal and distal esophageal mucosa.

    PubMed

    Woodland, Philip; Aktar, Rubina; Mthunzi, Engelbert; Lee, Chung; Peiris, Madusha; Preston, Sean L; Blackshaw, L Ashley; Sifrim, Daniel

    2015-03-15

    Little is known about the mucosal phenotype of the proximal human esophagus. There is evidence to suggest that the proximal esophagus is more sensitive to chemical and mechanical stimulation compared with the distal. This may have physiological relevance (e.g., in prevention of aspiration of gastroesophageal refluxate), but also pathological relevance (e.g., in reflux perception or dysphagia). Reasons for this increased sensitivity are unclear but may include impairment in mucosal barrier integrity or changes in sensory innervation. We assessed mucosal barrier integrity and afferent nerve distribution in the proximal and distal esophagus of healthy human volunteers. In 10 healthy volunteers baseline proximal and distal esophageal impedance was measured in vivo. Esophageal mucosal biopsies from the distal and proximal esophagus were taken, and baseline transepithelial electrical resistance (TER) was measured in Ussing chambers. Biopsies were examined immunohistochemically for presence and location of calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers. In a further four healthy volunteers we investigated for colocalization of CGRP and protein gene product (PGP) 9.5 immunoreactivity in nerve fibers. Baseline impedance was higher in the proximal than in the distal esophagus [2,936 Ω (SD578) vs. 2,229 Ω (SD821); P = 0.03], however, baseline TER was not significantly different between them. Mucosal CGRP-immunoreactive nerves were found in the epithelium of both proximal and distal esophagus, but were located more superficially in the proximal mucosa compared with the distal [11.5 (SD7) vs. 21.7 (SD5) cell layers from lumen, P = 0.002] 19% of proximal, and 10% of distal mucosal PGP-immunoreactive fibers colocalized with CGRP. PGP-immunoreactive fibers were also significantly closer to the luminal surface in the proximal compared with the distal esophagus (P < 0.001). We conclude that mucosal barrier integrity is similar in proximal and distal esophagus

  18. Topological location and structural importance of the NBCe1-A residues mutated in proximal renal tubular acidosis.

    PubMed

    Zhu, Quansheng; Kao, Liyo; Azimov, Rustam; Newman, Debra; Liu, Weixin; Pushkin, Alexander; Abuladze, Natalia; Kurtz, Ira

    2010-04-30

    NBCe1-A electrogenically cotransports Na(+) and HCO(3)(-) across the basolateral membrane of renal proximal tubule cells. Eight missense mutations and 3 nonsense mutations in NBCe1-A cause severe proximal renal tubular acidosis (pRTA). In this study, the topologic properties and structural importance of the 8 endogenous residues mutated in pRTA and the in situ topology of NBCe1-A were examined by the substituted cysteine accessibility method. Of the 55 analyzed individually introduced cysteines, 8 were labeled with both membrane permeant (biotin maleimide (BM)) and impermeant (2-((5(6)-tetramethylrhodamine)carboxylamino)ethyl methanethiosulfonate (MTS-TAMRA)) sulfhydryl reagents, 4 with only BM, and 3 with only MTS-TAMRA. The location of the labeled and unlabeled introduced cysteines clearly indicates that the transmembrane region of NBCe1-A contains 14 transmembrane segments (TMs). In this in situ based NBCe1-A topology, residues mutated in pRTA (pRTA residues) are assigned as: Ser(427), TM1; Thr(485) and Gly(486), TM3; Arg(510) and Leu(522), TM4; Ala(799), TM10; and Arg(881), TM12. Substitution of pRTA residues with cysteines impaired the membrane trafficking of R510C and R881C, the remaining membrane-processed constructs had various impaired transport function. Surprisingly, none of the membrane-processed constructs was accessible to labeling with BM and MTS-TAMRA, nor were they functionally sensitive to the inhibition by (2-aminoethyl)methanethiosulfonate. Functional analysis of Thr(485) with different amino acid substitutions indicated it resides in a unique region important for NBCe1-A function. Our findings demonstrate that the pRTA residues in NBCe1-A are buried in the protein complex/lipid bilayer where they perform important structural roles.

  19. Topological Location and Structural Importance of the NBCe1-A Residues Mutated in Proximal Renal Tubular Acidosis*

    PubMed Central

    Zhu, Quansheng; Kao, Liyo; Azimov, Rustam; Newman, Debra; Liu, Weixin; Pushkin, Alexander; Abuladze, Natalia; Kurtz, Ira

    2010-01-01

    NBCe1-A electrogenically cotransports Na+ and HCO3− across the basolateral membrane of renal proximal tubule cells. Eight missense mutations and 3 nonsense mutations in NBCe1-A cause severe proximal renal tubular acidosis (pRTA). In this study, the topologic properties and structural importance of the 8 endogenous residues mutated in pRTA and the in situ topology of NBCe1-A were examined by the substituted cysteine accessibility method. Of the 55 analyzed individually introduced cysteines, 8 were labeled with both membrane permeant (biotin maleimide (BM)) and impermeant (2-((5(6)-tetramethylrhodamine)carboxylamino)ethyl methanethiosulfonate (MTS-TAMRA)) sulfhydryl reagents, 4 with only BM, and 3 with only MTS-TAMRA. The location of the labeled and unlabeled introduced cysteines clearly indicates that the transmembrane region of NBCe1-A contains 14 transmembrane segments (TMs). In this in situ based NBCe1-A topology, residues mutated in pRTA (pRTA residues) are assigned as: Ser427, TM1; Thr485 and Gly486, TM3; Arg510 and Leu522, TM4; Ala799, TM10; and Arg881, TM12. Substitution of pRTA residues with cysteines impaired the membrane trafficking of R510C and R881C, the remaining membrane-processed constructs had various impaired transport function. Surprisingly, none of the membrane-processed constructs was accessible to labeling with BM and MTS-TAMRA, nor were they functionally sensitive to the inhibition by (2-aminoethyl)methanethiosulfonate. Functional analysis of Thr485 with different amino acid substitutions indicated it resides in a unique region important for NBCe1-A function. Our findings demonstrate that the pRTA residues in NBCe1-A are buried in the protein complex/lipid bilayer where they perform important structural roles. PMID:20197274

  20. Cyclophilin B Interacts with Sodium-Potassium ATPase and Is Required for Pump Activity in Proximal Tubule Cells of the Kidney

    PubMed Central

    Suñé, Guillermo; Sarró, Eduard; Puigmulé, Marta; López-Hellín, Joan; Zufferey, Madeleine; Pertel, Thomas; Luban, Jeremy; Meseguer, Anna

    2010-01-01

    Cyclophilins (Cyps), the intracellular receptors for Cyclosporine A (CsA), are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions are inhibited upon CsA binding. Albeit its great benefits as immunosuppressant, the use of CsA has been limited by undesirable nephrotoxic effects, including sodium retention, hypertension, hyperkalemia, interstial fibrosis and progressive renal failure in transplant recipients. In this report, we focused on the identification of novel CypB-interacting proteins to understand the role of CypB in kidney function and, in turn, to gain further insight into the molecular mechanisms of CsA-induced toxicity. By means of yeast two-hybrid screens with human kidney cDNA, we discovered a novel interaction between CypB and the membrane Na/K-ATPase β1 subunit protein (Na/K-β1) that was confirmed by pull-down, co-immunoprecipitation and confocal microscopy, in proximal tubule-derived HK-2 cells. The Na/K-ATPase pump, a key plasma membrane transporter, is responsible for maintenance of electrical Na+ and K+ gradients across the membrane. We showed that CypB silencing produced similar effects on Na/K-ATPase activity than CsA treatment in HK-2 cells. It was also observed an enrichment of both alpha and beta subunits in the ER, what suggested a possible failure on the maturation and routing of the pump from this compartment towards the plasma membrane. These data indicate that CypB through its interaction with Na/K-β1 might regulate maturation and trafficking of the pump through the secretory pathway, offering new insights into the relationship between cyclophilins and the nephrotoxic effects of CsA. PMID:21085665