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1

Mechanism of proximal NaCl reabsorption in the proximal tubule of the mammalian kidney.  

PubMed

In the mammalian proximal tubule NaCl reabsorption occurs by both passive and active transport processes. Passive NaCl reabsorption occurs in the presence of a high luminal chloride and a low luminal bicarbonate concentration. These anion gradients provide the driving forces for diffusive Na and Cl movement. Na is driven by the lumen positive PD effected by the greater permeability of the tubular wall to Cl than to HCO3. Cl is driven by its high tubular concentration. Passive NaCl reabsorption accounts for only about 10% to 15% of total proximal NaCl transport. The remaining proximal NaCl is reabsorbed by active transport processes and occurs both in the presence or absence of anion gradients reabsorption. Two mechanisms of active NaCl reabsorption participate in active NaCl reabsorption along the proximal tubule. Firstly, active NaCl reabsorption is electrogenic. In the early proximal tubule Na enters to cell coupled to organic solute transport. This Na reabsorption generates a lumen negative PD and effects "coupled" electrogenic NaCl reabsorption. This mechanism is limited by the supply of organic solutes and is blunted by the greater Na than Cl permeability in the proximal tubule; it probably can account for no more than 10% of proximal NaCl reabsorption. In the terminal proximal tubule, the proximal straight tubule, the apical membrane appears to possess a channel for Na entry. This Na reabsorption also generates a lumen negative PD and effects "simple" electrogenic NaCl reabsorption. This mechanism is limited by the low transport capacity of this segment and probably accounts for no more than 5% to 10% of total proximal NaCl reabsorption. The great bulk of proximal NaCl reabsorption occurs along the entire proximal tubule by active, transcellular electroneutral NaCl reabsorption. The precise cellular transport mechanisms responsible for this process are only recently being defined. At the apical membrane parallel ion exchangers are responsible for NaCl entry into the cell. Na enters via the apical membrane Na-H antiporter. Cl most likely crosses the apical membrane by some combination of Cl-OH and Cl-HCO2 exchangers but not via a Cl-HCO3 exchanger. The relative contributions of Cl-OH and Cl-HCO2 exchange have not been defined. There are two important considerations in this question. First is the availbility of OH versus HCO2. Although there is an infinite supply of OH and a small equilibrium supply of HCO2, it is possible that the luminal concentration of HCO2 could be increased by an USL that raises the concentration of HCO2 to a degree sufficient to supply H2CO2 recycling for physiological transcellular Cl transport rates.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2034928

Berry, C A; Rector, F C

1991-03-01

2

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

SciTech Connect

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.

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

1987-01-01

3

Regulatory mechanisms of Na+\\/glucose cotransporters in renal proximal tubule cells  

Microsoft Academic Search

Glucose is a key fuel and an important metabolic substrate in mammals. Renal proximal tubular cells (PTCs) not only reabsorb filtered glucose but are also believed to play a role in the glucotoxicity associated with renal pathogenesis, such as in diabetes. The proximal tubule environment is where 90% of the filtered glucose is reabsorbed by the low-affinity\\/high-capacity Na+\\/glucose cotransporter 2

Y J Lee; H J Han

2007-01-01

4

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

SciTech Connect

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.

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

1987-01-01

5

Role of the Na+/H+ antiporter in rat proximal tubule bicarbonate absorption.  

PubMed Central

Amiloride and the more potent amiloride analog, 5-(N-t-butyl) amiloride (t-butylamiloride), were used to examine the role of the Na+/H+ antiporter in bicarbonate absorption in the in vivo microperfused rat proximal convoluted tubule. Bicarbonate absorption was inhibited 29, 46, and 47% by 0.9 mM or 4.3 mM amiloride, or 1 mM t-butylamiloride, respectively. Sensitivity of the Na+/H+ antiporter to these compounds in vivo was examined using fluorescent measurements of intracellular pH with (2', 7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein (BCECF). Amiloride and t-butylamiloride were shown to be as potent against the antiporter in vivo as in brush border membrane vesicles. A model of proximal tubule bicarbonate absorption was used to correct for changes in the luminal profiles for pH and inhibitor concentration, and for changes in luminal flow rate in the various series. We conclude that the majority of apical membrane proton secretion involved in transepithelial bicarbonate absorption is mediated by the Na+-dependent, amiloride-sensitive Na+H+ antiporter. However, a second mechanism of proton secretion contributes significantly to bicarbonate absorption. This mechanism is Na+-independent and amiloride-insensitive. PMID:2888788

Preisig, P A; Ives, H E; Cragoe, E J; Alpern, R J; Rector, F C

1987-01-01

6

Targeting of renal proximal tubule Na,K-ATPase by salt-inducible kinase.  

PubMed

The renal proximal tubule (RPT) is a central locale for Na+ reabsorption, and blood pressure regulation. Na+ reabsorption in the RPT depends upon the Na,K-ATPase, which is controlled by a complex regulatory network, including Salt-Inducible Protein Kinase (SIK). SIKs are recently discovered members of the AMP-activated Protein Kinase (AMPK) family, which regulate salt homeostasis and metabolism in a number of tissues. In the RPT, SIK interacts with the Na,K-ATPase in the basolateral membrane (BM), regulating both the activity and level of Na,K-ATPase in the BM. Thus, Na,K-ATPase activity can be rapidly adjusted in response to changes in Na+ balance. Long-term changes in Na+ intake affect the state of SIK phosphorylation, and as a consequence the phosphorylation of TORCs, Transducers of Regulated CREB (cAMP Regulatory Element Binding Protein). Once phosphorylated, TORCs enter the nucleus, and activate transcription of the ATP1B1 gene encoding for the Na,K-ATPase beta subunit. PMID:20152810

Taub, Mary; Springate, James E; Cutuli, Facundo

2010-03-12

7

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

PubMed

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

Neumann, K H; Rector, F C

1976-11-01

8

Intracellular pH regulation in the renal proximal tubule of the salamander. Na-H exchange  

PubMed Central

Using pH-sensitive microelectrodes to measure intracellular pH (pHi) in isolated, perfused proximal tubules of the tiger salamander Ambystoma tigrinum, we have found that when cells are acid-loaded by pretreatment with NH+4 in a nominally HCO3--free Ringer, pHi spontaneously recovers with an exponential time course. This pHi recovery, which is indicative of active (i.e., uphill) transport, is blocked by removal of Na+ from both the luminal and basolateral (i.e., bath) solutions. Re-addition of Na+ to either the lumen or the bath results in a full pHi recovery, but at a lower-than-normal rate; the maximal rate is achieved only with Na+ in both solutions. The diuretic amiloride reversibly inhibits the pHi recovery when present on either the luminal or basolateral sides, and has its maximal effect when present in both solutions. The pHi recovery is insensitive to stilbene derivatives and to Cl- removal. A transient rise of intracellular Na+ activity accompanies the pHi recovery; there is no change of intracellular Cl- activity. These data suggest that these proximal tubule cells have Na-H exchangers in both the luminal and basolateral membranes. PMID:6833996

1983-01-01

9

Reactive Oxygen Species Modulation of Na/K-ATPase Regulates Fibrosis and Renal Proximal Tubular Sodium Handling  

PubMed Central

The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS)-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT) sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS) are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase activity, its signaling, fibrosis, and RPT sodium reabsorption. PMID:22518311

Liu, Jiang; Kennedy, David J.; Yan, Yanling; Shapiro, Joseph I.

2012-01-01

10

Intracellular sodium modulates the state of protein kinase C phosphorylation of rat proximal tubule Na+,K+-ATPase.  

PubMed

The natriuretic hormone dopamine and the antinatriuretic hormone noradrenaline, acting on alpha-adrenergic receptors, have been shown to bidirectionally modulate the activity of renal tubular Na+,K+-adenosine triphosphate (ATPase). Here we have examined whether intracellular sodium concentration influences the effects of these bidirectional forces on the state of phosphorylation of Na+,K+-ATPase. Proximal tubules dissected from rat kidney were incubated with dopamine or the alpha-adrenergic agonist, oxymetazoline, and transiently permeabilized in a medium where sodium concentration ranged between 5 and 70 mM. The variations of sodium concentration in the medium had a proportional effect on intracellular sodium. Dopamine and protein kinase C (PKC) phosphorylate the catalytic subunit of rat Na+,K+-ATPase on the Ser23 residue. The level of PKC induced Na+,K+-ATPase phosphorylation was determined using an antibody that only recognizes Na+,K+-ATPase, which is not phosphorylated on its PKC site. Under basal conditions Na+,K+-ATPase was predominantly in its phosphorylated state. When intracellular sodium was increased, Na+,K+-ATPase was predominantly in its dephosphorylated state. Phosphorylation of Na+,K+-ATPase by dopamine was most pronounced when intracellular sodium was high, and dephosphorylation by oxymetazoline was most pronounced when intracellular sodium was low. The oxymetazoline effect was mimicked by the calcium ionophore A23187. An inhibitor of the calcium-dependent protein phosphatase, calcineurin, increased the state of Na+,K+-ATPase phosphorylation. The results imply that phosphorylation of renal Na+,K+-ATPase activity is modulated by the level of intracellular sodium and that this effect involves PKC and calcium signalling pathways. The findings may have implication for the regulation of salt excretion and sodium homeostasis. PMID:12028137

Ibarra, F R; Cheng, S X Jun; Agrén, M; Svensson, L-B; Aizman, O; Aperia, A

2002-06-01

11

Ouabain-Stimulated Trafficking Regulation of the Na/K-ATPase and NHE3 In Renal Proximal Tubule Cells  

PubMed Central

We have demonstrated that ouabain regulates protein trafficking of the Na/K-ATPase ?1 subunit and NHE3 (Na/H exchanger, isoform 3) via ouabain-activated Na/K-ATPase signaling in porcine LLC-PK1 cells. To investigate whether this mechanism is species-specific, ouabain-induced regulation of the ?1 subunit and NHE3 as well as transcellular 22Na+ transport were compared in three renal proximal tubular cell lines (human HK-2, porcine LLC-PK1, and AAC-19 originated from LLC-PK1 in which the pig ?1 was replaced by ouabain-resistant rat ?1). Ouabain inhibited transcellular 22Na+ transport due to an ouabain-induced redistribution of the ?1 subunit and NHE3. In LLC-PK1 cells, ouabain also inhibited the endocytic recycling of internalized NHE3, but has no significant effect on recycling of endocytosed ?1 subunit. These data indicated that the ouabain-induced redistribution of the ?1 subunit and NHE3 is not a species-specific phenomenon, and ouabain-activated Na/K-ATPase signaling influences NHE3 regulation. PMID:22618525

Yan, Yanling; Haller, Steven; Shapiro, Anna; Malhotra, Nathan; Tian, Jiang; Xie, Zijian; Malhotra, Deepak; Shapiro, Joseph I.; Liu, Jiang

2012-01-01

12

Development of a scintillation proximity assay for analysis of Na+/Cl- -dependent neurotransmitter transporter activity.  

PubMed

Human placental choriocarcinoma (JAR) cells endogenously expressing glycine transporter type 1a (GlyT1a) have been cultured in 96-well scintillating microplates to develop a homogenous screening assay for the detection of GlyT1 antagonists. In these microplates uptake of [14C]glycine was time dependent and saturable with a Michaelis-Menten constant (Km) of 27+/-3 microM. The GlyT1 transport inhibitors sarcosine, ALX-5407, and Org-24598 were tested and shown to block [14C]glycine uptake with expected IC50 values of 37.5+/-4.6 microM, 2.8+/-0.6 nM, and 6.9+/-0.9 nM, respectively. The [14C]glycine uptake process was sensitive to membrane Na+ gradient as blockade of membrane Na+/K+-ATPase by ouabain or Na+ exchanger by benzamil-disrupted glycine accumulation in JAR cells. Glycine influx was not affected by concentration of dimethyl sulfoxide up to 2%. The versatility of this technological approach was further confirmed by the characterization of a saturable [14C]taurine uptake in JAR cells. Taurine transport was of high affinity with a Km of 10.2+/-1.7 microM and fully inhibited by ALX-5407 (IC50=522 +/-83 nM). The developed assay is homogenous, rapid, versatile and amenable to automation for the discovery of new neurotransmitter transporter inhibitors. PMID:12963052

Williams, Jacinta B; Mallorga, Pierre J; Lemaire, Wei; Williams, David L; Na, Sang; Patel, Smita; Conn, P Jeffrey; Conn, Jeffrey P; Pettibone, Douglas J; Austin, Christopher; Sur, Cyrille

2003-10-01

13

Differences in epithelial morphology correlate to Na(+)-transport: a study of the proximal, mid, and distal regions of the coprodeum from hens on high and low NaCl diet.  

PubMed

A study was performed to correlate regional morphology and amiloride inhibitable Na(+)-transport in the coprodeal epithelium in hens, Gallus domesticus, on low-NaCl diet and in controls. Proximal (close to colon), mid and distal (close to urodeum) regions were examined using light microscopy, transmission- and scanning electron microscopy. Na(+)-transport was measured electrophysiologically in Ussing-chambers in the proximal and distal regions. The epithelium, simple and columnar, is composed of absorptive intestinal epithelial cells, goblet cells, brush cells, migrating lymphoid cells, and enteroendocrine cells. Brush cells, identified in avians for the first time, occur in highest number in the proximal part of the coprodeum in low-NaCl hens. Na(+)-transport is high in the low-NaCl hens, ranging from 347 microA/cm2 (proximal) to 187 microA/cm2 (distal). In control hens, which correspond to hens on high-NaCl diet, it is low in all regions (0-4 microA/cm2). Absorptive intestinal epithelial cells as well as brush cells adapt to variations in transepithelial Na(+)-transport by regulating height and packing density of their microvilli, number, size, and localization of apical vesicles, and the width of the intercellular space. Regional differences in the epithelial cell composition and ultrastructure are closely correlated to transepithelial Na(+)-transport but only in low-NaCl hens, as controls do not show these variations. PMID:9918098

Elbrønd, V S; Dantzer, V; Skadhauge, E

1999-01-01

14

Basolateral membrane Na/base cotransport is dependent on CO2/HCO3 in the proximal convoluted tubule  

PubMed Central

The mechanism of basolateral membrane base transport was examined in the in vitro microperfused rabbit proximal convoluted tubule (PCT) in the absence and presence of ambient CO2/HCO3- by means of the microfluorometric measurement of cell pH. The buffer capacity of the cells measured using rapid NH3 washout was 42.8 +/- 5.6 mmol.liter-1.pH unit-1 in the absence and 84.6 +/- 7.3 mmol.liter-1.pH unit-1 in the presence of CO2/HCO3-. In the presence of CO2/HCO3-, lowering peritubular pH from 7.4 to 6.8 acidified the cell by 0.30 pH units and lowering peritubular Na from 147 to 0 mM acidified the cell by 0.25 pH units. Both effects were inhibited by peritubular 4-acetamido-4'- isothiocyanostilbene-2,2'-disulfonate (SITS). In the absence of exogenous CO2/HCO3-, lowering peritubular pH from 7.4 to 6.8 acidified the cell by 0.25 pH units and lowering peritubular Na from 147 to 0 mM decreased cell pH by 0.20 pH units. Lowering bath pH from 7.4 to 6.8 induced a proton flux of 643 +/- 51 pmol.mm-1.min-1 in the presence of exogenous CO2/HCO3- and 223 +/- 27 pmol.mm-1.min-1 in its absence. Lowering bath Na from 147 to 0 mM induced proton fluxes of 596 +/- 77 pmol.mm-1.min-1 in its absence. The cell acidification induced by lowering bath pH or bath Na in the absence of CO2/HCO3- was inhibited by peritubular SITS or by acetazolamide, whereas peritubular amiloride had no effect. In the absence of exogenous CO2/HCO3-, cyanide blocked the cell acidification induced by bath Na removal, but was without effect in the presence of exogenous CO2/HCO3-. We reached the following conclusions. (a) The basolateral Na/base n greater than 1 cotransporter in the rabbit PCT has an absolute requirement for CO2/HCO3-. (b) In spite of this CO2 dependence, in the absence of exogenous CO2/HCO3-, metabolically produced CO2/HCO3- is sufficient to keep the transporter running at 30% of its control rate in the presence of ambient CO2/HCO3- . (c) There is no apparent amiloride-sensitive Na/H antiporter on the basolateral membrane of the rabbit PCT. PMID:2831294

1987-01-01

15

Role of adenosine triphosphate (ATP) and NaK ATPase in the inhibition of proximal tubule transport with intracellular cystine loading.  

PubMed

Cellular cystine loading with cystine dimethyl ester inhibits volume absorption, transepithelial potential difference, glucose transport, and bicarbonate transport in proximal convoluted tubules perfused in vitro. This study examined the roles of ATP and NaK ATPase in this in vitro model of the Fanconi syndrome of cystinosis. Intracellular ATP was measured using the luciferin-luciferase assay. Intracellular ATP was reduced by 60% in proximal convoluted tubules incubated with 0.5 mM cystine dimethyl ester for 15 min at 37 degrees C (P less than 0.001). Incubation of cystine loaded tubules with 1 mM exogenous ATP increased intracellular ATP to levels not significantly different than that of controls. On the other hand, Vmax NaK ATPase activity was unchanged even though the incubation times and the concentration of cystine dimethyl ester were doubled to 30 min and 1 mM, respectively. In proximal convoluted tubules perfused in vitro, 0.5 mM cystine dimethyl ester resulted in an 89% inhibition in volume absorption (0.81 +/- 0.14 to 0.09 +/- 0.09 nl/mm.min), while there was only a 45% inhibition in volume absorption (P less than 0.01) due to cellular cystine loading in the presence of 1 mM lumen and bath ATP (0.94 +/- 0.05 to 0.52 +/- 0.11 nl/mm.min). These data demonstrate that proximal tubule cellular cystine loading decreases cellular ATP concentration, but does not directly inhibit NaK ATPase activity. The inhibition in transport and decrease in intracellular ATP due to cellular cystine loading was ameliorated by exogenous ATP. These data are consistent with cellular ATP depletion playing a major role in the inhibition of proximal tubule transport due to intracellular cystine loading. PMID:1847941

Coor, C; Salmon, R F; Quigley, R; Marver, D; Baum, M

1991-03-01

16

Inorganic Phosphate Modulates the Expression of the NaPi-2a Transporter in the trans-Golgi Network and the Interaction with PIST in the Proximal Tubule  

PubMed Central

Inorganic phosphate (Pi) homeostasis is maintained by the tight regulation of renal Pi excretion versus reabsorption rates that are in turn modulated by adjusting the number of Pi transporters (mainly NaPi-2a) in the proximal tubules. In response to some hormones and a high dietary Pi content, NaPi-2a is endocytosed and degraded in the lysosomes; however, we show here that some NaPi-2a molecules are targeted to the trans-Golgi network (TGN) during the endocytosis. In the TGN, NaPi-2a interacts with PIST (PDZ-domain protein interacting specifically with TC10), a TGN-resident PDZ-domain-containing protein. The extension of the interaction is proportional to the expression of NaPi-2a in the TGN, and, consistent with that, it is increased with a high Pi diet. When overexpressed in opossum kidney (OK) cells, PIST retains NaPi-2a in the TGN and inhibits Na-dependent Pi transport. Overexpression of PIST also prevents the adaptation of OK cells to a low Pi culture medium. Our data supports the view that NaPi-2a is subjected to retrograde trafficking from the plasma membrane to the TGN using one of the machineries involved in endosomal transport and explains the reported expression of NaPi-2a in the TGN. PMID:23509734

Lanaspa, Miguel A.; Caldas, Yupanqui A.; Breusegem, Sophia Y.; Andres-Hernando, Ana; Cicerchi, Christina; Levi, Moshe; Sorribas, Victor

2013-01-01

17

Silver ion (Ag+)-induced increases in cell membrane K+ and Na+ permeability in the renal proximal tubule: reversal by thiol reagents.  

PubMed

The initial mechanisms of injury to the proximal tubule following exposure to nephrotoxic heavy metals are not well established. We studied the immediate effects of silver (Ag+) on K+ transport and respiration with extracellular K+ and O2 electrodes in suspensions of renal cortical tubules. Addition of silver nitrate (AgNO3) to tubules suspended in bicarbonate Ringer's solution caused a rapid, dose-dependent net K+ efflux (Km = 10(-4) M, Vmax = 379 nmol K+/min/mg protein) which was not inhibited by furosemide, barium chloride, quinine, tetraethylammonium, or tolbutamide. An increase in the ouabain-sensitive oxygen consumption rate (QO2) (13.9 +/- 1.1 to 25.7 +/- 4.4 nmol O2/min/mg, P less than 0.001), was observed 19 sec after the K+ efflux induced by AgNO3 (10(-4) M), suggesting a delayed increase in Na+ entry into the cell. Ouabain-insensitive QO2, nystatin-stimulated QO2, and CCCP-uncoupled QO2 were not significantly affected, indicating preserved function of the Na+,K+-ATPase and mitochondria. External addition of the thiol reagents dithiothreitol (1 mM) and reduced glutathione (1 mM) prevented and/or immediately reversed the effects on K+ transport and QO2. We conclude that Ag+ causes early changes in the permeability of the cell membrane to K+ and then to Na+ at concentrations that do not limit Na+,K+-ATPase activity or mitochondrial function. These alterations are likely the result of a reversible interaction of Ag+ with sulfhydryl groups of cell membrane proteins and may represent initial cytotoxic effects common to other sulfhydryl-reactive heavy metals on the proximal tubule. PMID:2456393

Kone, B C; Kaleta, M; Gullans, S R

1988-04-01

18

Proximity fuze  

DOEpatents

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.

Harrison, T.R.

1987-07-10

19

Proximity fuze  

DOEpatents

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.

Harrison, Thomas R. (Stockton, CA)

1989-08-22

20

Proximal Tibial Bone Graft  

MedlinePLUS

... the Smaller Toes 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 ...

21

Bachelor Project Proximity Alert  

E-print Network

Bachelor Project Proximity Alert An Eclipse Plug-in for Software Analysis Andrea Casarella software applications. We built Proximity Alert, a recommender system that assigns to every part on top of which Proximity Alert is created. Thanks a lot to Alessandro Tettamanti, Matteo Dupraz

Lanza, Michele

22

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

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. It is suggested that Na{sup +} binding in renal ASCT2 may be regulated by ROS in SHR PTE cells.

Pinto, Vanda; Pinho, Maria Joao [Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto (Portugal)] [Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto (Portugal); Jose, Pedro A. [Center for Molecular Physiology Research, Children's National Medical Center, Department of Pediatrics, George Washington School of Medicine and Health Sciences, Washington, DC (United States)] [Center for Molecular Physiology Research, Children's National Medical Center, Department of Pediatrics, George Washington School of Medicine and Health Sciences, Washington, DC (United States); Soares-da-Silva, Patricio, E-mail: pss@med.up.pt [Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto (Portugal)] [Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto (Portugal)

2010-07-30

23

The interaction between megalin and ClC-5 is scaffolded by the Na?-H? exchanger regulatory factor 2 (NHERF2) in proximal tubule cells.  

PubMed

Albumin endocytosis in the proximal tubule is mediated by a number of proteins, including the scavenger receptor megalin/cubilin and the PSD-95/Dlg/ZO-1 (PDZ) scaffolds NHERF1 and NHERF2. In addition, in a number of in vitro and in vivo models, the loss of ClC-5 results in a decreased cell surface expression and whole cell level of megalin, suggesting an interaction between these two proteins in vivo. We investigated if ClC-5 and megalin interact directly, and as ClC-5 binds to NHERF2, we investigated if this PDZ scaffold was required for a megalin/ClC-5 complex. GST-pulldown and immunoprecipitation experiments using rat kidney lysate demonstrated an interaction between ClC-5 and megalin, which was mediated by their C-termini. As this interaction may be controlled by a scaffold protein, we characterised any interaction between megalin and NHERF2. Immunoprecipitation experiments indicated that megalin interacts with NHERF2 in vivo, and that this interaction was via an internal NHERF binding domain in the C-terminus of megalin and PDZ2 and the C-terminus of NHERF2. Silencing NHERF2 had no effect on megalin protein levels in the whole cell or plasma membrane. Using siRNA against NHERF2, we demonstrated that NHERF2 was required to facilitate the interaction between megalin and ClC-5. Using fusion proteins, we characterised a protein complex containing ClC-5 and megalin, which is scaffolded by NHERF2, in the absence of any other proteins. Importantly, these observations are the first to describe an interaction between megalin and ClC-5, which is scaffolded by NHERF2 in proximal tubule cells. PMID:22349218

Hryciw, D H; Jenkin, K A; Simcocks, A C; Grinfeld, E; McAinch, A J; Poronnik, P

2012-05-01

24

Proximal Humerus Fractures  

Microsoft Academic Search

Background: The purpose of this prospective study was to assess the short- and long-term outcome of proximal humerus fractures treated according to a standardized regime. Patients and Methods: 99 patients with fractures of the proximal humerus were included. Scapular antero-posterior and lateral radiographs were used to classify the fracture type with the Neer classification system. Treatment was nonoperative and included

Marie-Jeanne T. F. D. Vrancken Peeters; Gerard Willem Kastelein; Paul John Breslau

2001-01-01

25

Proximal humerus fractures.  

PubMed

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. PMID:24022417

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

2013-01-01

26

MOBILE PROXIMITY PAYMENT: ECOSYSTEM  

E-print Network

MOBILE PROXIMITY PAYMENT: ECOSYSTEM AND OVERVIEW OF NFC TECHNOLOGY 1. Introduction Handsets confirm and heterogeneous. The Mobile Payment ecosystem involves a number of partners, such as: · banks; · Mobile Network

Shamos, Michael I.

27

Capacitive proximity sensor  

DOEpatents

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.

Kronberg, J.W.

1994-05-31

28

Regulation of phosphate transport in proximal tubules.  

PubMed

Homeostasis of inorganic phosphate (P(i)) is primarily an affair of the kidneys. Reabsorption of the bulk of filtered P(i) occurs along the renal proximal tubule and is initiated by apically localized Na(+)-dependent P(i) cotransporters. Tubular P(i) reabsorption and therefore renal excretion of P(i) is controlled by a number of hormones, including phosphatonins, and metabolic factors. In most cases, regulation of P(i) reabsorption is achieved by changing the apical abundance of Na(+)/Pi cotransporters. The regulatory mechanisms involve various signaling pathways and a number of proteins that interact with Na(+)/P(i) cotransporters. PMID:18758808

Biber, J; Hernando, N; Forster, I; Murer, H

2009-05-01

29

Proximate Analysis of Coal  

ERIC Educational Resources Information Center

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,…

Donahue, Craig J.; Rais, Elizabeth A.

2009-01-01

30

Coded IR proximity detector  

Microsoft Academic Search

The coded IR proximity detector is able to generate an electrical signal when the distance between the detector and a certain object becomes shorter than a preset value. The detector may be used as an automotive indicator and control. The detector consists of four parts: a controller, a transmitter, a receiver and the optical system, used both for transmission and

Tudor Zisu; Sorin Miclos

2001-01-01

31

Subacute diabetic proximal neuropathy  

NASA Technical Reports Server (NTRS)

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, but such intervention may be considered in the severe and progressive cases or ones associated with severe neuropathic pain.

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

1997-01-01

32

Proximity Networks and Epidemics  

NASA Astrophysics Data System (ADS)

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.

Guclu, Hasan; Toroczkai, Zoltán

2007-03-01

33

Design of proximity detecting codes  

E-print Network

a four-phase asynchronous communication protocol (or other similar protocols). A non-trivial t-proximity detecting code must be unordered. However, not all unordered codes are t-proximity detecting. This thesis analyzes the designs and bounds...

Perisetty, Srinivas

2012-06-07

34

Proximal femoral fractures.  

PubMed

Fractures of the proximal femur include fractures of the head, neck, intertrochanteric, and subtrochanteric regions. Head fractures commonly accompany dislocations. Neck fractures and intertrochanteric fractures occur with greatest frequency in elderly patients with a low bone mineral density and are produced by low-energy mechanisms. Subtrochanteric fractures occur in a predominantly strong cortical osseous region which is exposed to large compressive stresses. Implants used to address these fractures must be able to accommodate significant loads while the fractures consolidate. Complications secondary to these injuries produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death. PMID:12597064

Webb, Lawrence X

2002-01-01

35

Echosonography with proximity sensors  

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

36

Safety evaluation, Proximate analysis,  

E-print Network

Objective: The aim of the study was to have bio-analytical approach for detoxification process of two poisonous plant materials viz. Aconitum laciniatum (root) and Abrus precatorius (seed) which are used in Ayurvedic preparations. Materials and Methods: For both the species proximate analysis was carried out. For the same plants HPTLC fingerprinting was compared, before and after detoxification process, using triphala quath. Infra red spectral studies for Abrus precatorius species (red and white) were compared, with respect to detoxification process. Protein fingerprinting was carried out for various Aconitum species available in the market. In support of the results obtained from the above methods for detoxification, safety evaluation, post single dose administration, C1- post single dose administration]was done using albino mice as the study model for Aconitum laciniatum (root) and Abrus precatorius (seeds- red and white). Outcome Measures: Comparison of the results for the crude poisonous

S. P. Bapat; R. T. Sane; Aconitum Laciniatum; Abrus Precatorius; Aconitum Palmatum; Aconitum Heterophyllum; R. T. Sane

37

Polymer infrared proximity sensor  

NASA Astrophysics Data System (ADS)

A proximity sensor that combines a polymer light-emitting diode and a polymer photodiode is presented. The operation wavelength is in the near infrared from 700to850nm. The infrared emission is obtained by adding a color conversion film of polyvinylpyrrolidone polymer matrix blended with infrared dye 1,1-diethyl-2,2-dicarbocyanine iodide to a red polymer light-emitting diode. The photodetector relies on the direct charge-transfer exciton generation in a donor-acceptor polymer blend of poly(3-hexylthiophene) and (6,6)-phenyl-C61-butyric acid methyl ester. The detection distance is up to 19cm for objects with various colors and roughness under ambient indoor lighting.

Chen, En-Chen; Tseng, Shin-Rong; Ju, Jia-Hong; Yang, Chia-Ming; Meng, Hsin-Fei; Horng, Sheng-Fu; Shu, Ching-Fong

2008-08-01

38

Proximal Femoral Allograft: Prognostic Indicators  

Microsoft Academic Search

Between 1972 and 1999, the Orthopedic Oncology Service treated 150 patients with resection and allograft transplantation of the proximal femur. Of the group, 121 patients had malignant tumors of the proximal femur and 29 had benign disorders. Four types of allografts were used: osteoarticular (46 patients), allograft-prosthesis (73), intercalary (20), and allograft-arthrodesis (5). Only 16% of the patients died of

Pedro J. Roque; Henry J. Mankin; Henrik Malchau

2010-01-01

39

Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal  

E-print Network

Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal Point Methods Yves Lucet & Warren Hare July 24, 2013 1 / 26 #12;Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Outline 1

40

Developmental changes in rabbit proximal straight tubule paracellular permeability  

PubMed Central

The early proximal tubule preferentially reabsorbs organic solutes and bicarbonate over chloride ions, resulting in a luminal fluid with a higher chloride concentration than that in blood. From this late proximal tubular fluid, one-half of NaCl reabsorption by the adult proximal tubule is active and transcellular and one-half is passive and paracellular. The purpose of the present in vitro microperfusion study was to determine the characteristics of passive chloride transport and permeability properties of the adult and neonatal proximal straight tubules (PST). In tubules perfused with a late proximal tubular fluid, net passive chloride flux was 131.7 ± 37.7 pmol·mm?1·min?1 in adult tubules and ?17.1 ± 23.3 pmol·mm?1·min?1 in neonatal proximal tubules (P < 0.01). Chloride permeability was 10.94 ± 5.21 × 10?5 cm/s in adult proximal tubules and ?1.26 ± 1.84 × 10?5 cm/s in neonatal proximal tubules (P < 0.05). Thus neonatal PST have a chloride permeability not different from zero and have no net passive chloride transport. Bicarbonate permeability is also less in neonates than adults in this segment (?0.07 ± 0.03 × 10?5 vs. 0.93 ± 0.27 × 10?5 cm/s, P < 0.01). Neonatal PST have higher sodium-to chloride and bicarbonate-to-chloride permeability ratios than adult PST. However, mannitol and sucrose permeabilities were not different in adult proximal tubules and neonatal PST. Transepithelial resistance was measured using current injection and cable analysis. The resistance was 6.7 ± 0.7 ?·cm2 in adult tubules and 11.3 ± 1.4 ?·cm2 in neonatal PST (P < 0.01). In conclusion, there are significant maturational changes in the characteristics of the PST paracellular pathway affecting transport in this nephron segment. PMID:12167604

QUIGLEY, RAYMOND; BAUM, D MICHEL

2014-01-01

41

Proximal tubular handling of phosphate: A molecular perspective.  

PubMed

Members of the SLC34 gene family of solute carriers encode for three Na+-dependent phosphate (P i) cotransporter proteins, two of which (NaPi-IIa/SLC34A1 and NaPi-IIc/SLC34A3) control renal reabsorption of P i in the proximal tubule of mammals, whereas NaPi-IIb/SCLC34A2 mediates P i transport in organs other than the kidney. The P i transport mechanism has been extensively studied in heterologous expression systems and structure-function studies have begun to reveal the intricacies of the transport cycle at the molecular level using techniques such as cysteine scanning mutagenesis, and voltage clamp fluorometry. Moreover, sequence differences between the three types of cotransporters have been exploited to obtain information about the molecular determinants of hormonal sensitivity and electrogenicity. Renal handling of P i is regulated by hormonal and non-hormonal factors. Changes in urinary excretion of P i are almost invariably mirrored by changes in the apical expression of NaPi-IIa and NaPi-IIc in proximal tubules. Therefore, understanding the mechanisms that control the apical expression of NaPi-IIa and NaPi-IIc as well as their functional properties is critical to understanding how an organism achieves P i homeostasis. PMID:16955105

Forster, I C; Hernando, N; Biber, J; Murer, H

2006-11-01

42

External knowledge sources and proximity  

Microsoft Academic Search

Purpose – Following the line traced by two previous works of Albino et al. and Messeni Petruzzelli, the paper aims to analyze how technology districts reach and acquire external competencies and capabilities by means of organizational and cognitive proximity. This allows districts to modify their geographical boundaries and evolve into technology clusters. Design\\/methodology\\/approach – The research design is based on

Antonio Messeni Petruzzelli; Vito Albino; Nunzia Carbonara

2009-01-01

43

Geographic Proximity and Enrollment Competition.  

ERIC Educational Resources Information Center

The use of a measure of geographic proximity to help explain enrollment competition among postsecondary institutions was investigated. The measure, the number of miles between institutions, was obtained by determining the longitude and latitude coordinates for about 99% of the schools in the Higher Education General Information System universe.…

Zammuto, Raymond F.

44

Pripism of the proximal penis.  

PubMed

A young man presented with a perineal mass that was found to be secondary to partial priapism of the proximal corpora cavernosa. This ia a rare condition with only 2 previously recorded cases in the urologic literature. Definitive treatment required a corpus cavernosum-spongiosum shunt. The patient has had a good recovery and was able to resume sexual activity. PMID:7420578

Llado, J; Peterson, L J; Fair, W R

1980-05-01

45

Alternating proximal regularized dictionary learning.  

PubMed

We present an algorithm for dictionary learning that is based on the alternating proximal algorithm studied by Attouch, Bolte, Redont, and Soubeyran ( 2010 ), coupled with a reliable and efficient dual algorithm for computation of the related proximity operators. This algorithm is suitable for a general dictionary learning model composed of a Bregman-type data fit term that accounts for the goodness of the representation and several convex penalization terms on the coefficients and atoms, explaining the prior knowledge at hand. As Attouch et al. recently proved, an alternating proximal scheme ensures better convergence properties than the simpler alternating minimization. We take care of the issue of inexactness in the computation of the involved proximity operators, giving a sound stopping criterion for the dual inner algorithm, which keeps under control the related errors, unavoidable for such a complex penalty terms, providing ultimately an overall effective procedure. Thanks to the generality of the proposed framework, we give an application in the context of genome-wide data understanding, revising the model proposed by Nowak, Hastie, Pollack, and Tibshirani ( 2011 ). The aim is to extract latent features (atoms) and perform segmentation on array-based comparative genomic hybridization (aCGH) data. We improve several important aspects that increase the quality and interpretability of the results. We show the effectiveness of the proposed model with two experiments on synthetic data, which highlight the enhancements over the original model. PMID:25248086

Salzo, Saverio; Masecchia, Salvatore; Verri, Alessandro; Barla, Annalisa

2014-12-01

46

Massive proximal femoral osteoarticular allograft  

Microsoft Academic Search

The implantation of massive allografts is a reconstruction alternative after limb salvage for aggressive bone tumours. It is hoped that durable long-term results can be obtained with these biological reconstructions. Revitalization of the allografts is one of the most important factors with regard to durability. One massive proximal femoral osteoarticular allograft is described that was followed up for 22 years.

P. Böhm; E. Renner; K. Rossak

1996-01-01

47

Foot anomalies and proximal symphalangism.  

PubMed

We report the case of a 2-week-old girl born at term (by vaginal delivery and without antenatal or perinatal events) who was referred as having "bilateral talipes and bilateral proximal symphalangism of little and ring fingers." The "talipes" was atypical with marked equinus and varus, but no cavus or adductus of the midfoot. Her mother had both symphalangism (absence of proximal interphalangeal joints) of middle, ring, and little fingers bilaterally and fixed pes planus with a rigid fixed hindfoot-and these deformities had also been present from birth. The maternal grandmother was similarly affected. However, the neonatal subject has an unaffected older sibling; maternal siblings are also unaffected. The three affected people did not have other obvious musculoskeletal abnormalities. Because of the coalitions, the child's atypical talipes was managed by a modified Kite's procedure. Symphalangism-coalition syndromes may be associated with conductive deafness because of fusion of the auditory ossicles. PMID:22294466

Shaw, Lauren; McCaul, Janet; Irwin, Greg J; Huntley, James S

2012-09-01

48

Intramedullary Chondrosarcoma of Proximal Humerus  

PubMed Central

Primary chondrosarcoma is the third most frequent primary malignancy of bone after myeloma and osteosarcoma. It is ranging from slow growing nonmetastasising lesions to highly aggressive lesions. We report a case of primary intramedullary chondrosarcoma of proximal humerus. A 60-year-old female presented with pain and hard swelling involving the left arm for 5 months. Radiograph showed a lucent expansile intramedullary lesion with matrix calcification and associated soft tissue mass. CT confirmed the finding. MRI showed a lobulated lesion which is hyperintense on T2WI with low signal fibrous septae. Increased tracer uptake was seen on bone scan. Histopathology confirmed the radiology diagnosis. The patient underwent wide resection and endoprosthetic reconstruction of proximal humerus. PMID:23243546

Yadav, Pratiksha; Thakkar, Dolly; Thind, S. S.

2012-01-01

49

Measuring and extracting proximity graphs in networks  

Microsoft Academic Search

Measuring distance or some other form of proximity between objects is a standard data mining tool. Connection subgraphs were recently proposed as a way to demonstrate proximity between nodes in networks. We propose a new way of measuring and extracting proximity in networks called \\

Yehuda Koren; Stephen C. North; Chris Volinsky

2007-01-01

50

Practical Attacks on Proximity Identification Systems  

E-print Network

Practical Attacks on Proximity Identification Systems Gerhard P. Hancke May 26, 2006 Practical Attacks on Proximity Identification Systems ­ p. #12;RFID Devices Applications Logistics Access control on Proximity Identification Systems ­ p. #12;Security Concerns Various attacks proposed Kfir and Wool (2005

Hancke, Gerhard

51

Modeling proximal tubule cell homeostasis: tracking changes in luminal flow.  

PubMed

During normal kidney function, there are routinely wide swings in proximal tubule fluid flow and proportional changes in Na(+) reabsorption across tubule epithelial cells. This "glomerulotubular balance" occurs in the absence of any substantial change in cell volume, and is thus a challenge to coordinate luminal membrane solute entry with peritubular membrane solute exit. In this work, linear optimal control theory is applied to generate a configuration of regulated transporters that could achieve this result. A previously developed model of rat proximal tubule epithelium is linearized about a physiologic reference condition; the approximate linear system is recast as a dynamical system; and a Riccati equation is solved to yield the optimal linear feedback that stabilizes Na(+) flux, cell volume, and cell pH. The first observation is that optimal feedback control is largely consigned to three physiologic variables, cell volume, cell electrical potential, and lateral intercellular hydrostatic pressure. Parameter modulation by cell volume stabilizes cell volume; parameter modulation by electrical potential or interspace pressure act to stabilize Na(+) flux and cell pH. This feedback control is utilized in a tracking problem, in which reabsorptive Na(+) flux varies over a factor of two, in order to represent a substantial excursion of glomerulotubular balance. The resulting control parameters consist of two terms, an autonomous term and a feedback term, and both terms include transporters on both luminal and peritubular cell membranes. Overall, the increase in Na(+) flux is achieved with upregulation of luminal Na(+)/H(+) exchange and Na(+)-glucose cotransport, with increased peritubular Na(+)-3HCO(3)(-) and K(+)-Cl(-) cotransport, and with increased Na(+), K(+)-ATPase activity. The configuration of activated transporters emerges as a testable hypothesis of the molecular basis for glomerulotubular balance. It is suggested that the autonomous control component at each cell membrane could represent the cytoskeletal effects of luminal flow. PMID:19280266

Weinstein, Alan M; Sontag, Eduardo D

2009-08-01

52

MODELING PROXIMAL TUBULE CELL HOMEOSTASIS: TRACKING CHANGES IN LUMINAL FLOW  

PubMed Central

During normal kidney function, there are are routinely wide swings in proximal tubule fluid flow and proportional changes in Na+ reabsorption across tubule epithelial cells. This "glomerulotubular balance" occurs in the absence of any substantial change in cell volume, and is thus a challenge to coordinate luminal membrane solute entry with peritubular membrane solute exit. In this work, linear optimal control theory is applied to generate a configuration of regulated transporters that could achieve this result. A previously developed model of rat proximal tubule epithelium is linearized about a physiologic reference condition; the approximate linear system is recast as a dynamical system; and a Riccati equation is solved to yield the optimal linear feedback that stabilizes Na+ flux, cell volume, and cell pH. The first observation is that optimal feedback control is largely consigned to three physiologic variables, cell volume, cell electrical potential, and lateral intercellular hydrostatic pressure. Parameter modulation by cell volume stabilizes cell volume; parameter modulation by electrical potential or interspace pressure act to stabilize Na+ flux and cell pH. This feedback control is utilized in a tracking problem, in which reabsorptive Na+ flux varies over a factor of two. The resulting control parameters consist of two terms, an autonomous term and a feedback term, and both terms include transporters on both luminal and peritubular cell membranes. Overall, the increase in Na+ flux is achieved with upregulation of luminal Na+/H+ exchange and Na+-glucose cotransport, with increased peritubular Na+?3HCO3? and K+ ? Cl? cotransport, and with increased Na+, K+-ATPase activity. The configuration of activated transporters emerges as testable hypothesis of the molecular basis for glomerulotubular balance. It is suggested that the autonomous control component at each cell membrane could represent the cytoskeletal effects of luminal flow. PMID:19280266

Weinstein, Alan M.; Sontag, Eduardo D.

2009-01-01

53

The HTV Proximity Communication System  

NASA Astrophysics Data System (ADS)

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 Processor (BBP) to the HTV Guidance and Control Computer (GCC) including data handling and communication equipments, the PROX detects it by monitoring interruption of the "heartbeat" signal and conducts automatic redundancy switching of all the equipments on that "communication path" including those of the HTV. This paper describes the PROX functions such as communication, data handling and GPS navigation and some unique functions for the HTV proximity operation to the ISS.

Harada, Motoyuki; Takahashi, Tetsuo; Tanaka, Tetsuo

2002-01-01

54

Ion transport in rat proximal colon in vivo.  

PubMed

Active Na+ absorption by the rat proximal colon in vivo is for the most part electrically silent. The rheogenic Na+ flux makes up only 8%. To elucidate the underlying transport pathways, the following experimental approaches were used: ion substitution experiments such as choline for Na+, cyclamate for Cl-, variation of luminal pH; administration of known inhibitors; and determination of changes in luminal CO2 tension and pH. The transcolonic ion fluxes as well as the electrical parameters potential difference, specific electrical resistance, and short-circuit current were monitored. Na+ transport was drastically reduced in the absence of luminal Cl-, and vice versa Cl- absorption was blocked at zero Na+. NaCl absorption was blocked by amiloride (10(-3) M) and 4-acetamido-4'-isothiocyanostilbene-2, 2'-disulfonic acid and was lowered by acetazolamide. Colonic NaCl absorption was not influenced by luminal furosemide. Na+ absorption increased with alkalinization of the luminal fluid. Tris instead of HCO-3 buffer at constant pH favored Cl- uptake. The results may easily be explained by the operation of a Na+-H+ antiport functionally coupled to a Cl(-)-HCO-3 antiport. These transport processes are supposed to be present in the columnar cells of the colonic epithelium. There is good evidence for the association of K+ secretion with rheogenic Cl- secretion by the crypt cells. PMID:2425635

Lübcke, R; Haag, K; Berger, E; Knauf, H; Gerok, W

1986-07-01

55

Proximal bodies in hypersonic flow  

SciTech Connect

Hypersonic flows involving two or more bodies travelling in close proximity to one another are encountered in several important situations, both natural and man-made. The present work seeks to investigate one aspect of the resulting flow problem by exploring the forces experienced by a secondary body when it is within the domain of influence of a primary body travelling at hypersonic speeds. An analytical methodology based on the blast wave analogy is developed and used to predict the secondary force coefficients for simple geometries in both two and three dimensions. When the secondary body is entirely inside the primary shocked region, the nature of the lateral force coefficient is found to depend strongly on the relative size of the two bodies. For two spheres, the methodology predicts that the secondary body will experience an exclusively attractive lateral force if the secondary diameter is larger than one-sixth the primary diameter. The analytical results are compared with those from numerical simulations and reasonable agreement is observed if an appropriate normalization for the lateral displacement is used. Results from a series of experiments in the T5 hypervelocity shock tunnel are also presented and compared with perfect-gas numerical simulations, with good agreement. A new force-measurement technique for short-duration hypersonic facilities, enabling the experimental simulation of the proximal bodies problem, is described. This technique provides two independent means of measurement, and the agreement observed between the two gives a further degree of confidence in the results obtained.

Deiterding, Ralf [ORNL; Laurence, Stuart J [California Institute of Technology, Pasadena; Hornung, Hans G [California Institute of Technology, Pasadena

2007-01-01

56

Fibrosis: ultimate and proximate causes.  

PubMed

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

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

2014-11-01

57

Ash Aggregates in Proximal Settings  

NASA Astrophysics Data System (ADS)

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 ?m). 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 early pyroclastic phase of the formation of Kima'Kho, a tuya in northern B.C., Canada produced a subaqueous pyroclastic cone which became emergent during the latter stages of formation. Armoured lapilli are pervasive within the emergent upper third of the sequence. No other types of ash aggregates have been observed. Petrographic and textural analysis of the armoured lapilli shows them to comprise a central 2-30 mm-sized, juvenile, vesiculated pyroclast, concentrically coated by mm-scale layers of 10-250 ?m sized ash particles. At Kima'Kho, the armoured lapilli are shown to be a direct indicator of fallout from a sustained plume attended by concomitant production of pyroclastic density currents. The size and internal structure of the armoured lapilli provide constraints on the nature of the initial explosive phase of eruption at Kima'Kho. Their proximity to the vent also indicates rapid aggregation within the eruption plume. Within both sequences rapid aggregation of ash particles occurred in proximity to the vent. However, the conditions were substantially different leading to the production of armoured lapilli (no accretionary lapilli) at Kima'Kho and diverse ash aggregates but no armoured lapilli at A418. Here we investigate vent-proximal ash aggregation and the specific conditions which lead to the formation of coated ash pellets and armoured lapilli.

Porritt, L. A.; Russell, K.

2012-12-01

58

Efficient algorithms for proximity problems  

SciTech Connect

Computational geometry is currently a very active area of research in computer science because of its applications to VLSI design, database retrieval, robotics, pattern recognition, etc. The author studies a number of proximity problems which are fundamental in computational geometry. Optimal or improved sequential and parallel algorithms for these problems are presented. Along the way, some relations among the proximity problems are also established. Chapter 2 presents an O(N log{sup 2} N) time divide-and-conquer algorithm for solving the all pairs geographic nearest neighbors problem (GNN) for a set of N sites in the plane under any L{sub p} metric. Chapter 3 presents an O(N log N) divide-and-conquer algorithm for computing the angle restricted Voronoi diagram for a set of N sites in the plane. Chapter 4 introduces a new data structure for the dynamic version of GNN. Chapter 5 defines a new formalism called the quasi-valid range aggregation. This formalism leads to a new and simple method for reducing non-range query-like problems to range queries and often to orthogonal range queries, with immediate applications to the attracted neighbor and the planar all-pairs nearest neighbors problem. Chapter 6 introduces a new approach for the construction of the Voronoi diagram. Using this approach, we design an O(log N) time O (N) processor algorithm for constructing the Voronoi diagram with L{sub 1} and L. metrics on a CREW PRAM machine. Even though the GNN and the Delaunay triangulation (DT) do not have an inclusion relation, we show, using some range type queries, how to efficiently construct DT from the GNN relations over a constant number of angular ranges.

Wee, Y.C.

1989-01-01

59

Second metatarsal stress fracture in sport: comparative risk factors between proximal and non?proximal locations  

PubMed Central

Background Stress fractures of the second metatarsal are common injuries in athletes and military recruits. There are two distinct areas in the second metatarsal where stress fractures develop: one proximal (at the base) and the other non?proximal (distal). Diagnosis can be difficult, and there is a difference in prognosis and treatment of the two types of stress fracture. Therefore differentiation of fracture location is warranted. Differences in risk factors and clinical outcomes between proximal and non?proximal stress fractures have not been studied. Objective To determine whether different risk factors and/or clinical outcomes associated with proximal and non?proximal stress fractures of the second metatarsal exist. Methods Patients diagnosed with proximal stress fractures of the second metatarsal were included in the study. Retrospectively, an age?matched control group with a non?proximal stress fracture was selected for comparison. Statistical analysis involved bivariate comparisons of demographic variables and clinical measurement between the two groups. Results Patients with proximal stress fractures were more likely to be chronically affected, usually exhibited an Achilles contracture, showed differences in length of first compared with second metatarsal, were more likely to experience multiple stress fractures, and exhibited low bone mass. In addition, a high degree of training slightly increased the risk of a non?proximal fracture, whereas low training volume was associated with a proximal stress fracture. Conclusion The signs, symptoms and clinical findings associated with proximal metatarsal stress fractures are different from those of non?proximal stress fractures. PMID:17339282

Chuckpaiwong, Bavornrit; Cook, Chad; Pietrobon, Ricado; Nunley, James A

2007-01-01

60

Range gated strip proximity sensor  

DOEpatents

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.

McEwan, Thomas E. (Livermore, CA)

1996-01-01

61

Range gated strip proximity sensor  

DOEpatents

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.

McEwan, T.E.

1996-12-03

62

Proximate sources of collective teacher efficacy  

Microsoft Academic Search

Purpose – Recent scholarship has augmented Bandura's theory underlying efficacy formation by pointing to more proximate sources of efficacy information involved in forming collective teacher efficacy. These proximate sources of efficacy information theoretically shape a teacher's perception of the teaching context, operationalizing the difficulty of the teaching task that faces the school and the faculty's collective competence to be successful

Curt M. Adams; Patrick B. Forsyth

2006-01-01

63

Proximate Sources of Collective Teacher Efficacy  

ERIC Educational Resources Information Center

Purpose: Recent scholarship has augmented Bandura's theory underlying efficacy formation by pointing to more proximate sources of efficacy information involved in forming collective teacher efficacy. These proximate sources of efficacy information theoretically shape a teacher's perception of the teaching context, operationalizing the difficulty…

Adams, Curt M.; Forsyth, Patrick B.

2006-01-01

64

Proximal Participation: A Pathway into Work  

ERIC Educational Resources Information Center

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…

Chan, Selena

2013-01-01

65

Claudin-2-deficient mice are defective in the leaky and cation-selective paracellular permeability properties of renal proximal tubules  

PubMed Central

Claudin-2 is highly expressed in tight junctions of mouse renal proximal tubules, which possess a leaky epithelium whose unique permeability properties underlie their high rate of NaCl reabsorption. To investigate the role of claudin-2 in paracellular NaCl transport in this nephron segment, we generated knockout mice lacking claudin-2 (Cldn2?/?). The Cldn2?/? mice displayed normal appearance, activity, growth, and behavior. Light microscopy revealed no gross histological abnormalities in the Cldn2?/? kidney. Ultrathin section and freeze-fracture replica electron microscopy revealed that, similar to those of wild types, the proximal tubules of Cldn2?/? mice were characterized by poorly developed tight junctions with one or two continuous tight junction strands. In contrast, studies in isolated, perfused S2 segments of proximal tubules showed that net transepithelial reabsorption of Na+, Cl–, and water was significantly decreased in Cldn2?/? mice and that there was an increase in paracellular shunt resistance without affecting the apical or basolateral membrane resistances. Moreover, deletion of claudin-2 caused a loss of cation (Na+) selectivity and therefore relative anion (Cl–) selectivity in the proximal tubule paracellular pathway. With free access to water and food, fractional Na+ and Cl– excretions in Cldn2?/? mice were similar to those in wild types, but both were greater in Cldn2?/? mice after i.v. administration of 2% NaCl. We conclude that claudin-2 constitutes leaky and cation (Na+)–selective paracellular channels within tight junctions of mouse proximal tubules. PMID:20385797

Muto, Shigeaki; Hata, Masaki; Taniguchi, Junichi; Tsuruoka, Shuichi; Moriwaki, Kazumasa; Saitou, Mitinori; Furuse, Kyoko; Sasaki, Hiroyuki; Fujimura, Akio; Imai, Masashi; Kusano, Eiji; Tsukita, Shoichiro; Furuse, Mikio

2010-01-01

66

Opportunistic, collaborative and synchronized, proximal device ecology  

E-print Network

CoSync is an on-device software framework for coordinating proximal consumer electronic devices in order to create a synchronized, opportunistic and collaborative device ecology. The CoSync device ecology combines multiple ...

Toledano, Eyal

2013-01-01

67

Control of spacecraft in proximity orbits  

E-print Network

Formation flying of spacecraft and autonomous rendezvous and docking of spacecraft are two missions in which satellites operate in close proximity and their relative trajectories are critically important. Both classes of ...

Breger, Louis Scott, 1979-

2007-01-01

68

A Proximal Point Algorithm with Bregman Distances  

E-print Network

problem of finding zeros of a maximal monotone operator T. Lately, many works ..... numerator, which is the difference between the mean and marginal effort to move, ...... [20] Iusem, A. N., Svaiter, B. F. and Teboulle, M. Entropy like proximal ...

2007-04-18

69

Promoting proximal formative assessment with relational discourse  

NSDL National Science Digital Library

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.

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

2012-05-15

70

Self-adaptive inexact proximal point methods  

Microsoft Academic Search

We propose a class of self-adaptive proximal point methods suitable for degenerate optimization problems where multiple minimizers\\u000a may exist, or where the Hessian may be singular at a local minimizer. If the proximal regularization parameter has the form\\u000a \\u000a \\u000a where ??[0,2) and ?>0 is a constant, we obtain convergence to the set of minimizers that is linear for ?=0 and ?

William W. Hager; Hongchao Zhang

2008-01-01

71

Chronic palmar dislocation of proximal interphalangeal joints.  

PubMed

Seven patients with chronic palmar dislocations of proximal interphalangeal joints are described. The duration of the dislocation ranged from 4 weeks to 19 months. Satisfactory mobility was restored in each patient after operative reduction and reconstruction of the extensor mechanism. Motion of the proximal interphalangeal joint averaged 57.1 degrees and 29.3 degrees at the distal interphalangeal joint. This method of treatment is preferable to an arthrodesis in selected patients. PMID:3958459

Posner, M A; Kapila, D

1986-03-01

72

Proton gradient formation in early endosomes from proximal tubules.  

PubMed

Heavy endosomes were isolated from proximal tubules using a combination of magnesium precipitation and wheat-germ agglutinin negative selection techniques. Two small GTPases (Rab4 and Rab5) known to be specifically present in early endosomes were identified in our preparations. Endosomal acidification was followed fluorimetrically using acridine orange. In presence of chloride ions and ATP, the formation of a proton gradient (delta pH) was observed. This process is due to the activity of an electrogenic V-type ATPase present in the endosomal membrane since specific inhibitors bafilomycin and folimycin effectively prevented or eliminated endosomal acidification. In presence of chloride ions (K(m) = 30 mM) the formation of the proton gradient was optimal. Inhibitors of chloride channel activity such as DIDS and NPPB reduced acidification. The presence of sodium ions stimulated the dissipation of the proton gradient. This effect of sodium was abolished by amiloride derivative (MIA) but only when loaded into endosomes, indicating the presence of a physiologically oriented Na+/H(+)-exchanger in the endosomal membrane. Monensin restored the gradient dissipation. Thus three proteins (V-type ATPase, Cl(-)-channel, Na+/H(+)-exchanger) present in early endosomes isolated from proximal tubules may regulate the formation, maintenance and dissipation of the proton gradient. PMID:8914581

Marshansky, V; Vinay, P

1996-10-23

73

Proximity sensor system development. CRADA final report  

SciTech Connect

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.

Haley, D.C. [Oak Ridge National Lab., TN (United States); Pigoski, T.M. [Merrit Systems, Inc. (United States)

1998-01-01

74

Models for coupling of salt and water transport; Proximal tubular reabsorption in Necturus kidney  

Microsoft Academic Search

Models for coupling of salt and water transport are developed with two important assumptions appropriate for leaky epithelia. (a) The tight junction is permeable to both salt and water. (b) Active Na transport into the lateral spaces is assumed to occur uniformly along the length of the channel. The proposed models deal specifically with the intraepithelial mechanism of proximal tubular

HENRY SACKIN; EMILE L. BOULPAEP

1975-01-01

75

Context-Aware Group Services in Proximity-Based Mobile Social Networks  

E-print Network

Groups exist in mobile users' social interactions Groups can be used for apps based on informationContext-Aware Group Services in Proximity-Based Mobile Social Networks Na Yu and Dr. Qi Han (http contexts into contacts to generate user mobility profiles with PoI visits and contacts; - Construct

76

Giant proximity effect in ferromagnetic bilayers  

NASA Astrophysics Data System (ADS)

The proximity effect is a phenomenon where an ordered state leaks from a material into an adjacent one over some finite distance, ?. For superconductors, this distance is ˜ the coherence length. Nevertheless much longer-range, ``giant'' proximity effects have been observed in cuprate junctions. This surprising effect can be understood as a consequence of critical opalescence. Since this occurs near all second order phase transitions, giant proximity effects should be very general and, in particular, they should be present in magnetic systems. The ferromagnetic proximity effect has the advantage that its order parameter (magnetization) can be observed directly. We investigate the above phenomenon in Co/EuS bilayer films, where both materials undergo ferromagnetic transitions but at rather different temperatures (bulk TC of 1400K for Co and 16.6K for EuS). A dramatic increase in the range of the proximity effect is expected near the TC of EuS. We present the results of our measurements of the magnetization profiles as a function of temperature, carried out using the complementary techniques of low energy muon rotation and polarized neutron reflectivity.

Ramos, Silvia; Charlton, Tim; Quintanilla, Jorge; Suter, Andreas; Moodera, Jagadeesh; Prokscha, Thomas; Salman, Zaher; Forgan, Ted

2013-03-01

77

Proximity operations concept design study, task 6  

NASA Astrophysics Data System (ADS)

The feasibility of using optical technology to perform the mission of the proximity operations communications subsystem on Space Station Freedom was determined. Proximity operations mission requirements are determined and the relationship to the overall operational environment of the space station is defined. From this information, the design requirements of the communication subsystem are derived. Based on these requirements, a preliminary design is developed and the feasibility of implementation determined. To support the Orbital Maneuvering Vehicle and National Space Transportation System, the optical system development is straightforward. The requirements on extra-vehicular activity are such as to allow large fields of uncertainty, thus exacerbating the acquisition problem; however, an approach is given that could mitigate this problem. In general, it is found that such a system could indeed perform the proximity operations mission requirement, with some development required to support extra-vehicular activity.

Williams, A. N.

1990-04-01

78

Superconducting proximity effect in semiconductor nanowires  

NASA Astrophysics Data System (ADS)

We theoretically consider the proximity effect in semiconductor-superconductor hybrid nanostructures, which are being extensively studied in the context of the ongoing search for non-Abelian Majorana fermions in solid state systems. Specifically, we consider the dependence on the thickness of the semiconductor in the direction normal to the interface, a physical effect that has been uncritically neglected in prior work on the subject. Quite surprisingly, we find the unanticipated result that increasing the semiconductor thickness leads to a suppression of the induced superconducting gap due to proximity-induced interband coupling. As a result, in the limit of strong semiconductor-superconductor coupling, the proximity-induced gap becomes much smaller than the bulk superconductor gap and depends weakly on the interface transparency.

Stanescu, Tudor D.; Das Sarma, S.

2013-05-01

79

Proximal symphalangism and premature ovarian failure.  

PubMed

Proximal symphalangism is a rare autosomal dominant affection responsible for multiple joint ankylosis, it results from NOG gene mutation whose locus is on 17q21-22. This gene may be involved in secretory functions of glands such as ovarian function. Premature ovarian failure is idiopathic in 80% of cases but may be secondary to multiple etiologies including genetic. We report the case of a patient with proximal symphalangism and premature ovarian failure, and we discuss the possibility of genetic relationship between the two anomalies. PMID:22088931

Kadi, Nadira; Tahiri, Latifa; Maziane, Mariame; Mernissi, Fatima Zahra; Harzy, Taoufik

2012-01-01

80

Application of proximity sensors to robotic manipulations  

E-print Network

1992 Major Subject: Bioengineering APPLICATION OF PROXIMITY SENSORS TO ROBOTIC MANIPULATIONS A Thesis by RAINER J. FINK Approved as to style and content by: Geral . Miller (Cha' f Committee) G. Hog ( ad of Dep tment) CI z C ( I Brad D. Etter... 1992 Major Subject: Bioengineering APPLICATION OF PROXIMITY SENSORS TO ROBOTIC MANIPULATIONS A Thesis by RAINER J. FINK Approved as to style and content by: Geral . Miller (Cha' f Committee) G. Hog ( ad of Dep tment) CI z C ( I Brad D. Etter...

Fink, Rainer J.

2012-06-07

81

Luminal secretion of ammonia in the mouse proximal tubule perfused in vitro.  

PubMed Central

A major portion of the total ammonia (tNH3 = NH3 + NH+4) produced by the isolated perfused mouse proximal tubule is secreted into the luminal fluid. To assess the role of Na+-H+ exchange in net tNH3 secretion, rates of net tNH3 secretion and tNH3 production were measured in proximal tubule segments perfused with control pH 7.4 Krebs-Ringer bicarbonate (KRB) buffer or with modified KRB buffers containing 10 mM sodium and 0.1 mM amiloride. Net tNH3 secretion was inhibited by 90% in proximal tubule segments perfused with the pH 7.4 modified KRB buffer while tNH3 production remained unaffected. The inhibition of net tNH3 secretion by perfusion with the modified KRB buffer was only partially reversed by acidifying the modified KRB luminal perfusate from 7.4 to as low as 6.2. These data indicate that the Na+-H+ exchanger facilitates a major portion of net tNH3 secretion by the proximal tubule and that luminal acidification may play only a partial role in the mechanism by which the Na+-H+ exchanger mediates net tNH3 secretion. PMID:3121674

Nagami, G T

1988-01-01

82

Interpersonal Violence between College Students: Proximal Influences.  

ERIC Educational Resources Information Center

This paper presents the results of a 3 year study on violence between students at the University of Maryland. The study was designed to: (1) describe the prevalence of fighting between students; (2) analyze, by gender, students' description of their most recent physical fight with another for proximal influences on these altercations; (3) analyze…

Marcus, Robert; Reio, Thomas; Kessler, Lauren; Cutler, Kelley; Fleury, John

83

Goal-Proximity Decision-Making  

ERIC Educational Resources Information Center

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…

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

2013-01-01

84

Computing proximal points of nonconvex functions  

E-print Network

power of proximal points is not constrained to the convex case. ... [31, Thm. 4.4]. The same relations are shown to hold in Hilbert and Banach spaces in [6] and [5], respectively. .... space). Remark 1 (lower-C2) The original definition of lower-C2 functions states: ...... Therefore, testing if the approximal estimate satisfies h(xn+1)

2006-01-18

85

Proximal symphalangism and premature ovarian failure  

Microsoft Academic Search

Proximal symphalangism is a rare autosomal dominant affection responsible for multiple joint ankylosis, it results from NOG gene mutation whose locus is on 17q21–22. This gene may be involved in secretory functions of glands such as ovarian function. Premature ovarian failure is idiopathic in 80% of cases but may be secondary to multiple etiologies including genetic. We report the case

Nadira Kadi; Latifa Tahiri; Mariame Maziane; Fatima Zahra Mernissi; Taoufik Harzy

86

An Efficient Proximity Probing Algorithm for Metrology  

E-print Network

An Efficient Proximity Probing Algorithm for Metrology F. Panahi A. Adler F. van der Stappen K Probing Algorithm for Metrology Fatemeh Panahi Aviv Adler A. Frank van der Stappen Ken Goldberg§ Abstract Metrology, the theoretical and practical study of measurement, has applications in auto- mated manufacturing

Utrecht, Universiteit

87

The Transverse Proximity Effect in Quasar Spectra  

E-print Network

The Transverse Proximity Effect in Quasar Spectra G´abor Worseck Astrophysikalisches Institut field generated by the overall population of quasars and star-forming galaxies. In the vicinity of sources of UV photons, such as luminous high-redshift quasars, the UV radiation field is enhanced due

88

Treatment of proximal vertebral artery disease.  

PubMed

Vertebral arterial disease (VAD) is a less commonly recognized and treated source of cerebrovascular ischemia compared with carotid artery disease. Patients are often referred for treatment after they have developed symptoms in the form of transient ischemic attacks or had a posterior hemispheric stroke. Traditional treatment of VAD has been surgical. More recently, endovascular treatment of VAD has been utilized. We performed a retrospective review of our institutional experience in treating VAD from 2001 to 2010. For treatment of proximal VAD, perioperative morbidity is lower for the endovascular group than for the surgical group, but six-week mortality was higher for the endovascular group. Complete resolution of symptoms occurred more frequently with surgery than with endovascular therapy. Therefore surgical reconstruction appears to be preferable to angioplasty and stenting for treatment of proximal vertebral artery occlusive disease. PMID:23518836

Shutze, William; Gierman, Joshua; McQuade, Karen; Pearl, Gregory; Smith, Bertram

2014-04-01

89

Giant Proximity Effect in Superfluid Helium  

NASA Astrophysics Data System (ADS)

Recently, it was shown that two confined regions of liquid 4He exhibit a proximity effect over distances much larger than the correlation length ?[1 2]. Here we report measurements of the superfluid fraction ?s/? and specific heat cp of a 33.6 nm film. Comparison with previous data from a 31.7 nm film in contact with an array of 34 × 106 (2 ?m)3 boxes of 4He allows us to show quantitatively the enhancement in ?s/? and cp due to the presence of the boxes in the temperature region where the film orders. The enhancement in ?s/? is observed up to distances 650 times the bulk correlation length. This anomalously large length scale is analogous to a giant proximity effect observed in High-Tc superconductors (HTSC)[3].

Perron, Justin K.; Gasparini, Francis M.

2012-12-01

90

Spin–orbit proximity effect in graphene  

NASA Astrophysics Data System (ADS)

The development of spintronics devices relies on efficient generation of spin-polarized currents and their electric-field-controlled manipulation. While observation of exceptionally long spin relaxation lengths makes graphene an intriguing material for spintronics studies, electric field modulation of spin currents is almost impossible due to negligible intrinsic spin–orbit coupling of graphene. In this work, we create an artificial interface between monolayer graphene and few-layer semiconducting tungsten disulphide. In these devices, we observe that graphene acquires spin–orbit coupling up to 17?meV, three orders of magnitude higher than its intrinsic value, without modifying the structure of the graphene. The proximity spin–orbit coupling leads to the spin Hall effect even at room temperature, and opens the door to spin field effect transistors. We show that intrinsic defects in tungsten disulphide play an important role in this proximity effect and that graphene can act as a probe to detect defects in semiconducting surfaces.

Avsar, A.; Tan, J. Y.; Taychatanapat, T.; Balakrishnan, J.; Koon, G. K. W.; Yeo, Y.; Lahiri, J.; Carvalho, A.; Rodin, A. S.; O’Farrell, E. C. T.; Eda, G.; Castro Neto, A. H.; Özyilmaz, B.

2014-09-01

91

Proximity-induced topological state in graphene  

NASA Astrophysics Data System (ADS)

The appearance of topologically protected states at the surface of an ordinary insulator is a rare occurrence and to date only a handful of materials are known for having this property. An intriguing question concerns the possibility of forming topologically protected interfaces between different materials. Here we propose that a topological phase can be transferred to graphene by proximity with the three-dimensional topological insulator Bi2Se3. By using density functional and transport theory, we prove that, at the verge of the chemical bond formation, a hybrid state forms at the graphene/Bi2Se3 interface. The state has Dirac-cone-like dispersion at the ? point and a well defined helical spin texture, indicating its topologically protected nature. This demonstrates that proximity can transfer the topological phase from Bi2Se3 to graphene.

Popov, Igor; Mantega, Mauro; Narayan, Awadhesh; Sanvito, Stefano

2014-07-01

92

Proximity effects in superconductor-ferromagnet heterostructures  

Microsoft Academic Search

The proximity effect at superconductor-ferromagnet interfaces produces damped oscillatory behavior of the Cooper pair wave function within the ferromagnetic medium. This is analogous to the inhomogeneous superconductivity, predicted long ago by Fulde and Ferrell (P. Fulde and R. A. Ferrell, 1964, ``Superconductivity in a strong spin-exchange field,'' Phys. Rev. 135, A550-A563), and by Larkin and Ovchinnikov (A. I. Larkin and

A. I. Buzdin

2005-01-01

93

Endoscopic Proximal Hamstring Repair and Ischial Bursectomy  

PubMed Central

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

Dierckman, Brian D.; Guanche, Carlos A.

2012-01-01

94

Proximal Sciatic Nerve Intraneural Ganglion Cyst  

PubMed Central

Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009. PMID:20069041

Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.

2009-01-01

95

Optical Fiber Proximity Sensor For Robotics Applications  

NASA Astrophysics Data System (ADS)

The paper presents a conception of an optical fiber proximity sensor designed for applications in robotics. A theoretical model of the sensor is offered as well as its computer analysis, including an examination of the effects of the sensor design parameters on its characteristics.Some results of experimental studies on the sensor are presented together with an example of the sensor's application in an industrial robot for the detection of obstacles on the robot arm's trajectory and control of their avoidance.

Marszalec, Janusz

1986-11-01

96

Examination of Derecho Environments Using Proximity Soundings  

Microsoft Academic Search

Observed upper air soundings that occurred within 2 h and 167 km of derechos were collected and analyzed to document atmospheric stability and wind shear conditions associated with long-lived convective windstorms. Sixty-seven derechos, accompanied by 113 proximity soundings, were identified during the years 1983-93. Owing to the large variability of the synoptic-scale environments associated with derechos, each derecho was further

Jeffry S. Evans; Charles A. Doswell III

2001-01-01

97

Management of proximal humerus fractures in adults.  

PubMed

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

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

2014-11-18

98

Management of proximal humerus fractures in adults  

PubMed Central

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.

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

2014-01-01

99

Proximity and Investment: Evidence from Plant-Level Data  

E-print Network

Proximity to plants makes it easier for headquarters to monitor and acquire information about plants. In this article, I estimate the effects of headquarters’ proximity to plants on plant-level investment and productivity. ...

Giroud, Xavier

100

REACH : the local social favor exchange : a proximal messaging system  

E-print Network

We define proximal messaging as that category of information transaction that takes into account the physical, social and temporal proximity between the sender and recipient as it relates to the content of the message. We ...

Kizelshteyn, Boris G. (Boris Grigory)

2012-01-01

101

Proximate composition and technological properties of fresh blackthorn ( Prunus spinosa L. subsp dasyphylla (Schur.)) fruits  

Microsoft Academic Search

In this study, the chemical and physical properties of blackthorn (Prunus spinosa subsp. dasyphlla (Schur.)) fruits growing wild in Konya province were determined. Proximate analysis such as dry matter, crude oil, crude protein, crude fibre, crude energy, ash, water-soluble and alcohol-soluble extract, pH and acid and mineral contents were established in this work. Al, B, Ca, K, Mg, Na, P

Derya Arslan; Musa Özcan

2005-01-01

102

Computer Vision Based Navigation for Spacecraft Proximity Operations  

E-print Network

Computer Vision Based Navigation for Spacecraft Proximity Operations Brent Edward Tweddle, David W. Miller February 2010 SSL # 1-10 #12;#12;Computer Vision Based Navigation for Spacecraft Proximity of Technology. #12;2 #12;Computer Vision Based Navigation for Spacecraft Proximity Operations by Brent Edward

103

16.1 INVESTIGATING DERECHO AND SUPERCELL PROXIMITY SOUNDINGS  

E-print Network

1 16.1 INVESTIGATING DERECHO AND SUPERCELL PROXIMITY SOUNDINGS Jeffry S. Evans* NOAA accumulated a number of proximity soundings associated with both derechos and discrete supercells. It can and analyzed 110 proximity soundings near 67 derechos. The period of study was from 1983-1993, and cases were

104

16.1 INVESTIGATING DERECHO AND SUPERCELL PROXIMITY SOUNDINGS  

E-print Network

1 16.1 INVESTIGATING DERECHO AND SUPERCELL PROXIMITY SOUNDINGS Jeffry S. Evans* NOAA of convection, we have accumulated proximity soundings associated with both derechos and discrete supercells and analyzed 113 proximity soundings near 67 derechos. The period of study was 1983-1993, and cases were

Doswell III, Charles A.

105

The proximal femoral morphometry of Turkish women on radiographs  

Microsoft Academic Search

SUMMARY In this study, proximal femoral morphometry was measured on radiographs of Turkish women. Hip fractures have high morbidity and mortality rates for people and is generally seen in elderly. It is known that the body mass index (BMI) and proximal femoral morphom- etry are important determinants of fracture risk. Our aim is to perform the measurements of proximal femoral

J. Irdesel; I. Ari

106

The regulation of proximal tubular salt transport in hypertension: an update  

PubMed Central

Purpose of review Renal proximal tubular sodium reabsorption is regulated by sodium transporters, including the sodium glucose transporter, sodium amino acid transporter, sodium hydrogen exchanger isoform 3 and sodium phosphate cotransporter type 2 located at the luminal/apical membrane, and sodium bicarbonate cotransporter and Na+/K+ATPase located at the basolateral membrane. This review summarizes recent studies on sodium transporters that play a major role in the increase in blood pressure in essential/polygenic hypertension. Recent findings Sodium transporters and Na+/K+ATPase are segregated in membrane lipid and nonlipid raft microdomains that regulate their activities and trafficking via cytoskeletal proteins. The increase in renal proximal tubule ion transport in polygenic hypertension is primarily due to increased activity of NHE3 and Cl/HCO3 exchanger at the luminal/apical membrane and a primary or secondary increase in Na+/K+ATPase activity. Summary The increase in renal proximal tubule ion transport in hypertension is due to increased actions by prohypertensive factors that are unopposed by antihypertensive factors. PMID:19654544

Wang, Xiaoyan; Armando, Ines; Upadhyay, Kiran; Pascua, Annabelle; Jose, Pedro A.

2013-01-01

107

Scintillation proximity assay using polymeric membranes  

SciTech Connect

Liquid scintillation counting (LSC) is typically used to quantify electron emitting isotopes. In LSC, radioactive samples are dissolved in an organic fluor solution (scintillation cocktail) to ensure that the label is close enough to the fluor molecules to be detected. Although efficient, scintillation cocktail is neither specific or selective for samples labeled with the same radioisotope. Scintillation cocktail is flammable posing significant health risks to the user and is expensive to purchase and discard. Scintillation Proximity Assay (SPA) is a radioanalytical technique where only those radiochemical entities (RCE's) bound to fluor containing matrices are detected. Only bound RCE's are in close enough proximity the entrapped fluor molecules to induce scintillations. Unbound radioligands are too far removed from the fluor molecules to be detected. The research in this dissertation focused on the development and evaluation of fluor-containing membranes (scintillation proximity membranes, SP membranes) to be used for specific radioanalytical techniques without using scintillation cocktail. Polysulfone and PVC SP membranes prepared in our laboratory were investigated for radioimmunossay (RIA) where only bound radioligand is detected, thereby eliminating the separation step impeding the automation of RIA. These SP membranes performed RIA where the results were nearly identical to commercial SP microbeads. SP membranes functionalized with quaternary ammonium hydroxide moieties were able to trap and quantify [sup 14]CO[sub 2] without using liquid scintillation cocktail. RCE's bound in the pore structure of SP membranes are intimate with the entrapped fluor providing the geometry needed for high detection efficiencies. Absorbent SP membranes were used in radiation surveys and were shown to be as effective as conventional survey techniques using filter paper and scintillation cocktail.

Mansfield, R.K.

1992-01-01

108

Proximal Magnetometry of Monolayers of Magnetic Moments  

NASA Astrophysics Data System (ADS)

We present a method to measure the magnetic properties of monolayers and ultra-thin films of magnetic material. The method is based on low energy muon spin rotation and ?-detected nuclear magnetic resonance measurements. A spin probe is used as a “proximal” magnetometer by implanting it in the substrate, just below the magnetic material. We calculate the expected magnetic field distribution sensed by the probe and discuss its temperature and implantation depth dependencies. This method is highly suitable for measuring the magnetic properties of monolayers of single molecule magnets, but can also be extended to ultra-thin magnetic films.

Salman, Z.; Blundell, S. J.

109

Proximity Effect for Metal Absorption Systems  

E-print Network

Using our photoionization code CIRRUS, we show that the study of proximity effect on metal elements provides a possibility of placing constraints on the spectral shape of the metagalactic UV background (MUVB). From theoretical point of view, the most optimum indicator of the spectral shape of the MUVB is the ratio OIV/OIII. Unlike previous thought, the ratio SiIV/CIV is not a good indicator of the spectral shape because of its strong dependence on an ionization parameter as well. We also find that the observed excess of CIV systems in luminous QSOs may be a photoionization effect, but not a gravitational lensing effect.

J. M. Liu

1997-09-13

110

Unilateral Isolated Proximal Femoral Focal Deficiency  

PubMed Central

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

Do?er, Emek; Köpük, ?ule Y.; Çak?ro?lu, Yi?it; Çak?r, Özgür; Yücesoy, Gülseren

2013-01-01

111

Giant cell tumour of the proximal radius.  

PubMed

A 52-year-old Indian woman presented with a progressively increasing swelling and pain in the right elbow for the past eight months, which was not associated with trauma or constitutional symptoms. The patient was diagnosed to have Campanacci grade III giant cell tumour of the proximal radius, and was treated with above elbow amputation. The patient has not shown any recurrence after five years of follow-up. The case was reported because of its rarity and the unusual site of occurrence of the tumour. PMID:19960152

Singh, A P; Mahajan, S; Singh, A P

2009-11-01

112

Space station proximity operations and window design  

NASA Technical Reports Server (NTRS)

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.

Haines, Richard F.

1988-01-01

113

Spin-orbit proximity effect in graphene.  

PubMed

The development of spintronics devices relies on efficient generation of spin-polarized currents and their electric-field-controlled manipulation. While observation of exceptionally long spin relaxation lengths makes graphene an intriguing material for spintronics studies, electric field modulation of spin currents is almost impossible due to negligible intrinsic spin-orbit coupling of graphene. In this work, we create an artificial interface between monolayer graphene and few-layer semiconducting tungsten disulphide. In these devices, we observe that graphene acquires spin-orbit coupling up to 17?meV, three orders of magnitude higher than its intrinsic value, without modifying the structure of the graphene. The proximity spin-orbit coupling leads to the spin Hall effect even at room temperature, and opens the door to spin field effect transistors. We show that intrinsic defects in tungsten disulphide play an important role in this proximity effect and that graphene can act as a probe to detect defects in semiconducting surfaces. PMID:25255743

Avsar, A; Tan, J Y; Taychatanapat, T; Balakrishnan, J; Koon, G K W; Yeo, Y; Lahiri, J; Carvalho, A; Rodin, A S; O'Farrell, E C T; Eda, G; Castro Neto, A H; Ozyilmaz, B

2014-01-01

114

An improved proximity force approximation for electrostatics  

SciTech Connect

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.

Fosco, Cesar D. [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina) [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo, R8402AGP Bariloche (Argentina); Lombardo, Fernando C. [Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina) [Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); IFIBA (Argentina)] [Argentina; Mazzitelli, Francisco D., E-mail: fdmazzi@cab.cnea.gov.ar [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina); Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)

2012-08-15

115

Proximate determinants of fertility in peninsular Malaysia.  

PubMed

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. PMID:21490114

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

2012-05-01

116

Obesity and Supermarket Access: Proximity or Price?  

PubMed Central

Objectives. We examined whether physical proximity to supermarkets or supermarket price was more strongly associated with obesity risk. Methods. The Seattle Obesity Study (SOS) collected and geocoded data on home addresses and food shopping destinations for a representative sample of adult residents of King County, Washington. Supermarkets were stratified into 3 price levels based on average cost of the market basket. Sociodemographic and health data were obtained from a telephone survey. Modified Poisson regression was used to test the associations between obesity and supermarket variables. Results. Only 1 in 7 respondents reported shopping at the nearest supermarket. The risk of obesity was not associated with street network distances between home and the nearest supermarket or the supermarket that SOS participants reported as their primary food source. The type of supermarket, by price, was found to be inversely and significantly associated with obesity rates, even after adjusting for individual-level sociodemographic and lifestyle variables, and proximity measures (adjusted relative risk?=?0.34; 95% confidence interval?=?0.19, 0.63) Conclusions. Improving physical access to supermarkets may be one strategy to deal with the obesity epidemic; improving economic access to healthy foods is another. PMID:22698052

Aggarwal, Anju; Hurvitz, Philip M.; Monsivais, Pablo; Moudon, Anne V

2012-01-01

117

Early effects of uranyl nitrate on respiration and K sup + transport in rabbit proximal tubule  

SciTech Connect

The mechanisms by which uranyl nitrate (UN) is toxic to the proximal tubule are incompletely understood. To define these further we studied potassium (K+) transport and oxygen consumption (QO2) in rabbit proximal tubule suspensions in vitro immediately after exposure to UN using extracellular O2- and K+-sensitive electrodes. UN caused a cumulative dose-dependent inhibition of proximal tubule QO2, with a threshold concentration of 5 x 10(-5) M. Kinetic analysis suggested two patterns of cell injury: a higher affinity inhibition of QO2 with a Ki of 5 x 10(-4) M, and a lower affinity inhibition of QO2 with a Ki of 10 mM. QO2 was studied in detail in the presence of these Ki concentrations of UN to define the initial cellular events. The results indicated that different cellular processes displayed different sensitivities to UN. At submillimolar concentrations UN caused progressive selective inhibition of ouabain-insensitive QO2 (15% inhibition at 2 minutes). Ouabain-sensitive QO2 and nystatin-stimulated QO2 were not affected, suggesting that Na+,K+-ATPase activity and its coupling to mitochondrial ATP synthesis were intact. Direct measurement of proximal tubule net K+ flux confirmed that Na+,K+-ATPase activity was unchanged. Similarly, UN did not inhibit basal (state 4) or ADP-stimulated (state 3) mitochondrial QO2 in digitonin-permeabilized tubules, confirming that the mitochondria were intact. In contrast, higher concentrations of UN (greater than or equal to 1 mM) caused rapid inhibition of QO2 and net K+ efflux, due to inhibition of Na+,K+-ATPase activity and mitochondrial injury.

Brady, H.R.; Kone, B.C.; Brenner, R.M.; Gullans, S.R. (Brigham and Women's Hospital, Boston, MA (USA))

1989-07-01

118

The Proximity Toolkit and ViconFace: Proximity Toolkit is a toolkit that simplifies the  

E-print Network

-end installation that tracks infrared reflective markers affixed to objects. Our API hides the low-level details was the Proximity Toolkit. Through the toolkit's API, developers can easily: · track particular objects of interest, top) · For each object, a developer can track its 3D position, orientation, and velocity (Figure 1

Greenberg, Saul

119

Water absorption in the proximal tubule: effect of bicarbonate, chloride gradient, and organic solutes.  

PubMed

Simultaneous in vivo capillary and luminal microperfusion studies were performed in the superficial proximal convoluted tubule of the rat to determine the effect of intraluminal bicarbonate, the imposition of a transepithelial chloride gradient, and the addition of organic solutes to the luminal perfusion solution on the rates of water absorption (Jv). The capillary perfusion solution contained NaCl, NaHCO3, and KCl. Perfusion of both capillary and lumen with the same solution resulted in a Jv of 3.01 +/- 0.24 nl/min/mm. Imposition of a transepithelial chloride gradient (equimolar substitution of NaCl for NaHCO3 in the luminal solution) resulted in a Jv of 3.18 +/- 0.21 nl/min/mm (P = NS). Addition of cyanide to both solutions in the presence of a chloride gradient resulted in a significantly lower Jv of 2.21 +/- 0.19 nl/min/mm. Luminal substitution of Na cyclamate for NaHCO3 resulted in a solution containing no bicarbonate and no chloride gradient. Jv averaged 0.34 +/- 0.08 nl/min/mm. Addition of cyanide to the solution totally inhibited Jv. The addition of D-glucose, L-alanine, or both, to luminal solutions containing bicarbonate or in the presence of a chloride gradient did not significantly affect Jv. Addition of both organic solutes to the NaCl-Na cyclamate luminal solution resulted in a significantly higher Jv of 0.77 +/- 0.14 nl/min/mm. These studies indicate that Jv in the rat superficial proximal tubule is influenced by active sodium transport, by the presence of bicarbonate in the lumen, and/or by the imposition of a transepithelial chloride gradient. The organic solutes D-glucose and L-alanine also influence water absorption, but this effect could only be demonstrated under some experimental conditions. PMID:6828448

Sansom, S C; Senekjian, H O; Knight, T F; Frommer, P; Weinman, E J

1983-01-01

120

Parallel Proximity Detection for Computer Simulation  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

121

Parallel Proximity Detection for Computer Simulations  

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

122

Eating Event Detection by Magnetic Proximity Sensing  

PubMed Central

Eating event detection is an important problem in automatic dietary study using a wearable computer, such as the eButton. In this work, we approach this detection problem based on the use of a small magnet marker attached to a finger and a miniature magnetometer installed within the eButton. Our experimental results indicate that our magnetic approach is effective when the distance between the marker and the wearable computer is within 12cm, and the range of detection is approximately 15cm. We also found that the proximity signal patterns corresponding to eating and other daily activities are different, which can be used to reduce the false detection rate. In addition, our approach is convenient, low-cost and energy efficient, suitable for practical applications. PMID:25342877

Li, Chengliu; Bai, Yicheng; Jia, Wenyan; Sun, Mingui

2014-01-01

123

Rendezvous and proximity operations sensor candidates  

NASA Astrophysics Data System (ADS)

As part of an ESA study, RVD and proximity operations on autonomous smart sensors for guidance between spacecraft are discussed. Measurement parameters for the sensors include range, range resolution, and range rate between 20 km and 0.1 m, and angular and lateral relative position between 20 km and 0.1 m. Sensors examined include a PRN Ku-band microwave range and attitude sensor, a CW laser diode range and attitude sensor, and a solid state smart camera for near field guidance. The study suggests that autonomous spacecraft docking is realistic to the extent that pin-to-pin connections/alignment can be warranted, and provided that the expected lateral offset of the docking/matching items to the sensor view area is sufficiently precise.

Kunkel, B.; Hartl, Ph.; Fehse, W.

1985-02-01

124

[Ophthalmologists in the proximity of Adolf Hitler].  

PubMed

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. PMID:22664943

Rohrbach, J M

2012-10-01

125

Proximity Operations and Docking Sensor Development  

NASA Technical Reports Server (NTRS)

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. In addition, the testing of the brassboard and proto-type NGAVGS units will be discussed along with the use of the NGAVGS as a proximity operations and docking sensor.

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

2009-01-01

126

Proximate industrial activity and psychological distress  

PubMed Central

This paper examines the role that gender, occupational status, and family status play in moderating the effect of industrial activity on the psychological well-being of nearby residents. Using a unique spatial assessment of industrial activity and an environmental risk/social stressor framework in conjunction with individual-level data from the Detroit Area Study (DAS) and demographic data from the U.S. census, we find that residents of neighborhoods in close proximity to industrial activity report elevated levels of psychological distress compared to residents of neighborhoods removed from this type of activity. These influences are more pronounced among women but gender differences are also contingent upon occupational and family statuses. We show that specific combinations of work and family statuses make persons particularly vulnerable to the influence of this environmental stressor and women are two and a half times more likely than men to have these vulnerable statuses. This study makes an important contribution to the environmental health literature because it reminds researchers of the fundamental influence of social roles when examining the link between environmental risks and mental health. PMID:19444334

Downey, Liam; Jackson, James S.; Merrill, J. Bryce; Saint Onge, Jarron M.; Williams, David R.

2009-01-01

127

Proximal spinal muscular atrophy: current orthopedic perspective  

PubMed Central

Spinal muscular atrophy (SMA) is a hereditary neuromuscular disease of lower motor neurons that is caused by a defective “survival motor neuron” (SMN) protein that is mainly associated with proximal progressive muscle weakness and atrophy. Although SMA involves a wide range of disease severity and a high mortality and morbidity rate, recent advances in multidisciplinary supportive care have enhanced quality of life and life expectancy. Active research for possible treatment options has become possible since the disease-causing gene defect was identified in 1995. Nevertheless, a causal therapy is not available at present, and therapeutic management of SMA remains challenging; the prolonged survival is increasing, especially orthopedic, respiratory and nutritive problems. This review focuses on orthopedic management of the disease, with discussion of key aspects that include scoliosis, muscular contractures, hip joint disorders, fractures, technical devices, and a comparative approach of conservative and surgical treatment. Also emphasized are associated complications including respiratory involvement, perioperative care and anesthesia, nutrition problems, and rehabilitation. The SMA disease course can be greatly improved with adequate therapy with established orthopedic procedures in a multidisciplinary therapeutic approach. PMID:24399883

Haaker, Gerrit; Fujak, Albert

2013-01-01

128

Effects of thrust reversing in ground proximity  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

129

Interactive orbital proximity operations planning system  

NASA Technical Reports Server (NTRS)

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.

Grunwald, Arthur J.; Ellis, Stephen R.

1988-01-01

130

Interactive orbital proximity operations planning system  

NASA Technical Reports Server (NTRS)

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.

Grunwald, Arthur J.; Ellis, Stephen R.

1989-01-01

131

Ion selectivity and proximal salt reabsorption.  

PubMed

Electrophysiological techniques were used in isolated perfused superficial (S) and juxtamedullary (JM) rabbit proximal convoluted tubules (PCT) to examine the relative sodium-to-chloride (PNa/PCl) and bicarbonate-to-chloride (PHCO3/PCl) permeability ratios. We found that the great majority of PCT are sodium selective and that PHCO3/PCl depends on the experimental conditions. In the presence of active sodium transport, PHCO3/PCl is high and increases with PNa/PCl. When PHCO3/PCl is determined after inhibition of active sodium transport or at 25 degrees C, PHCO3/PCl approximates the free solution anion mobility ratio of 0.5 and is independent of PNa/PCl. The difference between PHCO3/PCl determined in the presence of and in the absence of active transport suggests that the lowering of bath bicarbonate concentration in the presence of active transport changes both paracellular and transcellular current flow. In addition, we found that during luminal perfusion with high chloride, low bicarbonate, organic solute-free solutions, the transepithelial electrical potential depends on PNa/PCl and PHCO3/PCl. This potential is approximately 4.0 mV in S PCT with low PNa/PCl and falls progressively to zero in JM PCT with high PNa/PCl. From these data we conclude that anion concentration gradients drive an important diffusive flux of sodium chloride through the paracellular pathway only in PCT with low PNa/PCl ratios. PMID:696834

Berry, C A; Warnock, D G; Rector, F C

1978-09-01

132

Ranging/tracking system for proximity operations  

NASA Technical Reports Server (NTRS)

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.

Nilsen, P.; Udalov, S.

1982-01-01

133

Intralysosomal digestion of lysozyme in renal proximal tubule cells  

Microsoft Academic Search

Intralysosomal digestion of lysozyme in renal proximal tubule cells. This investigation was carried out to determine the ability of lysosomes in intact proximal tubule cells to digest absorbed protein. Lysozyme labeled with 125I was injected i.v. into rats and renal cortical slices removed after one hour. The slices were incubated in vitro for up to two hours. The location of

Erik Ilsø Christensen; Arvid B Maunsbach

1974-01-01

134

Mining Proximal Social Network Intelligence for Quality Decision Support  

Microsoft Academic Search

The concepts of proximity have been utilized for exploring both psychological and geographical incentives for users within social networks to collaborate with others for mutual goals. The massive information does not facilitate quality decision support. In this paper, we focus on mining the proximal social network intelligence for quality decision support. The utilization of investigating both the context and the

Yuan-chu Hwang

2009-01-01

135

Proximal symphalangism: Evidence of linkage to 17q  

Microsoft Academic Search

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

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

1994-01-01

136

Palliation of proximal malignant biliary obstruction by endoscopic endoprosthesis insertion  

Microsoft Academic Search

For four years up to December 1987, 190 patients (median age 73 years) with proximal malignant biliary obstruction were treated by endoscopic endoprosthesis insertion. Altogether 101 had cholangiocarcinoma, 21 gall bladder carcinoma, 20 local spread of pancreatic carcinoma, and 48 metastatic malignancy. Fifty eight patients had type I, 54 type II, and 78 type III proximal biliary strictures (Bismuth classification).

A A Polydorou; S R Cairns; J F Dowsett; A R Hatfield; P R Salmon; P B Cotton; R C Russell

1991-01-01

137

How Peer Proximity Moderates Indirect Media Influence on Adolescent Smoking  

Microsoft Academic Search

This study examines direct and indirect impacts of antismoking media messages on adolescents' smoking attitudes and intentions to smoke. Elaborating on the influence of presumed influence model, this study incorporates the moderating role of peer proximity (i.e., proximal versus distal peers). Analyzing direct effects in a survey of 1,687 middle school students, we find that antismoking media messages have unexpected

Hye-Jin Paek; Albert C. Gunther

2007-01-01

138

Geographic Constraints on Knowledge Diffusion: Political Borders vs. Spatial Proximity  

E-print Network

Geographic Constraints on Knowledge Diffusion: Political Borders vs. Spatial Proximity Jasjit Singh-based sampling in order to estimate the likelihood of citation between random patents. We find borders both role for political borders than for spatial proximity per se. The state border effect, although robust

Sekhon, Jasjeet S.

139

Equivalence of Entropy Regularization and Relative-Entropy Proximal Method  

E-print Network

Equivalence of Entropy Regularization and Relative-Entropy Proximal Method Jason K. Johnson May 16, 2008 Abstract We consider two entropy-based interior point methods that solve LP relaxations of MAP estimation in graphical models: (1) an entropy-regularization method and (2) a relative-entropy proximal

Willsky, Alan S.

140

Group Proximity Measure for Recommending Groups in Online Social Networks  

Microsoft Academic Search

There are currently, thousands of online social networks (OSN) available, each of which hosts millions of users. Users make new friendship links, join groups on diverse topics, share opinions and thus help in building a big knowledge repository. In this paper we study the problem of defining proximity measure between groups (communities) of OSN. Understanding the proximity among the groups

Barna Saha; Lise Getoor

141

Salvage of failed total hip arthroplasty with proximal femoral replacement.  

PubMed

EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Identify the available types of reconstruction for failed total hip arthroplasty. 2. Summarize the preoperative workup of patients with failed total hip arthroplasty and massive proximal femoral bone loss. 3. Assess the surgical technique of proximal femoral replacement for failed total hip arthroplasty. 4. Recognize treatment complications, patient outcomes, and survival of proximal femoral megaprostheses for revision of failed total hip arthroplasty. Despite recent advances in device manufacturing and surgical techniques, the management of proximal femoral bone loss in revision total hip arthroplasty remains challenging. Currently, failed total hip arthroplasty in elderly and less active patients, nonunion of the proximal femur with multiple failed attempts at osteosynthesis, resection arthroplasty, and massive proximal femoral bone loss can be salvaged with proximal femoral replacement using a megaprosthesis. The procedure is technically demanding and requires careful preoperative planning. Instability and aseptic loosening are the major complications, especially in younger and more active patients. The new generation of modular proximal femoral replacement megaprostheses and the increased experience obtained with these surgeries have reduced complication rates and improved outcomes. [Orthopedics. 2014; 37(10):691-698.]. PMID:25275970

Savvidou, Olga D; Mavrogenis, Andreas F; Sakellariou, Vasilios; Christogiannis, Ioannis; Vottis, Christos; Christodoulou, Michael; Vlasis, Konstantinos; Papagelopoulos, Panayiotis J

2014-09-01

142

Original article Proximate and amino acid composition of seeds of  

E-print Network

to be very similar to that of Faba bean seeds. The crude protein content (31.3% dry matter, DM) of CE shouldOriginal article Proximate and amino acid composition of seeds of Canavalia ensiformis le 10 septembre 1989) Summary — A proximate analysis of Canavalia ensiformis seeds (CE) appears

Paris-Sud XI, Université de

143

Physical Attractiveness and Proximity in the Attribution of Success.  

ERIC Educational Resources Information Center

This study assessed attributions made to an attractive or unattractive person who took either a proximal or distal seating position following task performance. Greater attributions of success were made to an attractive person, regardless of the proximity, which suggests pervasive influence of physical attractiveness on attributions in behavioral…

Hill, Michael K.; Kahn, Arnold

144

Proximity and territory versus space in regional science  

Microsoft Academic Search

Empirical evidence tends to show that regional development occurs only in certain places. Therefore, one can ask the central question of the role of physical proximity in economic development processes. Economists try to answer this question through the concept of externalities, but this does not explain why certain externalities are linked with physical proximity. In this paper the author tries

O Crevoisier

1996-01-01

145

Long-term stability of membrane transducers for proximity sensing  

Microsoft Academic Search

We report on the long-term stability of micromachined silicon membrane resonators for ultrasound based object detection and proximity sensing. The proximity sensor system measures distances up to 10 cm using either a phase or an acoustic Fabry-Perot measurement method. In these applications the transducer elements are continuously excited at their fundamental resonance using the thermomechanical excitation principle. The success of

Mark Hornung; Oliver Brand; Oliver Paul; Henry Baltes

1998-01-01

146

Protein detection using proximity-dependent DNA ligation assays  

Microsoft Academic Search

The advent of in vitro DNA amplification has enabled rapid acquisition of genomic information. We present here an analogous technique for protein detection, in which the coordinated and proximal binding of a target protein by two DNA aptamers promotes ligation of oligonucleotides linked to each aptamer affinity probe . The ligation of two such proximity probes gives rise to an

Simon Fredriksson; Mats Gullberg; Jonas Jarvius; Charlotta Olsson; Kristian Pietras; Sigrún Margrét Gústafsdóttir; Arne Östman; Ulf Landegren

2002-01-01

147

Bilateral non-osteochondroma-related proximal tibiofibular synostosis.  

PubMed

We report the case of a 67-year-old male with bilateral proximal tibiofibular synostosis, presenting with unilateral symptoms. The patient complained of pain around the left fibular head, which was attributed to incomplete bone bridging between the proximal tibia and fibula; he underwent proximal fibular head resection, which alleviated the pain and improved knee mobility. Eleven months later, the patient continued to be pain-free and did not experience any adverse effects. An examination of this case and a review of similar cases revealed that participation in sport activities such as long-distance running may be one of the causes of proximal tibiofibular synostosis. In this report, we have also reconsidered the classification of proximal tibiofibular synostosis and provided information for a better understanding of this unusual condition. PMID:24915740

Wakayama, Takanori; Imanishi, Jungo; Yazawa, Yasuo; Okubo, Taketo; Kaneko, Kazuo

2014-12-01

148

Parathyroid hormone decreases HCO3 reabsorption in the rat proximal tubule by stimulating phosphatidylinositol metabolism and inhibiting base exit.  

PubMed Central

The mechanism of inhibition of HCO3 transport by parathyroid hormone (PTH) in the proximal tubule is not clearly defined. Previous studies in vitro have suggested that this effect is mediated via cAMP generation, which acts to inhibit Na/H exchange, resulting in cell acidification. To examine this question in vivo, intracellular pH (pHi) was measured in the superficial proximal tubule of the rat using the pH-sensitive fluoroprobes 4-methylumbelliferone (4MU) and 2',7'-bis(carboxyethyl)-(5, and 6)-carboxyfluorescein (BCECF). PTH was found to alkalinize the cell. This alkalinization suggested inhibition of basolateral base exit, which was confirmed by in situ microperfusion studies: lowering HCO3 in peritubular capillaries acidified the cell, an effect blunted by PTH. Removal of luminal Na promoted basolateral base entry, alkalinizing the cell. This response was also blunted by PTH. Readdition of luminal Na stimulated the luminal Na/H exchanger, causing an alkalinization overshoot that was partially inhibited by PTH. cAMP inhibited luminal H secretion but did not alkalinize the cell. Stimulation of phosphatidylinositol-bis-phosphate turnover by PTH was suggested by the effect to the hormone to increase cell Ca. Blocking the PTH-induced rise in cell Ca blunted the effect of the hormone to alkalinize the cell, as did inhibition of phosphatidylinositol breakdown. Furthermore, stimulation of protein kinase C by a phorbol ester and a diacylglycerol applied basolaterally alkalinized the cell and inhibited luminal H secretion. The findings indicate that both arms of the phosphatidylinositol-bis-phosphate cascade play a role in mediating the effect of PTH on the cell pH. The results are consistent with the view that PTH inhibits base exit in the proximal tubule by activation of the phosphatidylinositol cascade. The resulting alkalinization may contribute, with cAMP, to inhibit apical Na/H exchange and the PTH-induced depression of proximal HCO3 reabsorption. PMID:1314850

Pastoriza-Munoz, E; Harrington, R M; Graber, M L

1992-01-01

149

Hypospadias and Residential Proximity to Pesticide Applications  

PubMed Central

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

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

2013-01-01

150

Nanocrystal Bioassembly: Asymmetry, Proximity, and Enzymatic Manipulation  

SciTech Connect

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.

Claridge, Shelley A

2008-05-01

151

Transport Magnetic Proximity Effects in Platinum  

NASA Astrophysics Data System (ADS)

Platinum (Pt) metal, being non-magnetic and having a strong spin-orbit coupling interaction, has been central in detecting pure spin current and establishing most of the recent spin-based phenomena. Thus, it is important to ascertain the transport and magnetic characteristics of thin Pt films in contact with a ferromagnet. In this work, we use both electric and thermal means to conclusively show the transport magnetic proximity effects (MPE) of thin Pt film in contact with ferromagnetic insulator YIG. At thicknesses comparable to, and less than, the spin diffusion length, the strong ferromagnetic characteristics in Pt films on YIG are indistinguishable from those of ferromagnetic permalloy on YIG. [1] The MPE occurs at the interface and decreases exponentially away from the interface, concentrating in only a few monolayers. As a result, the pure spin current detected by a thin Pt is tainted with a spin polarized current. The pure spin current phenomena, such as the inverse spin Hall effect and the spin Seebeck effect, have been contaminated with the anomalous Hall effect and the anomalous Nernst effect respectively. These results raise serious questions about the suitability, and the validity, of using Pt in establishing pure spin current phenomena; on the other hand, a much stronger spin-based effect can be induced by the MPE at the interface. This research is in collaboration with X. Fin, Y. P. Chen, J. Wu, and J. Q. Xiao (University of Delaware), T. Y. Chen (Arizona State University) and D. Qu, W. G. Wang, and C. L. Chien (The Johns Hopkins University).[4pt] [1] S. Y. Huang et al., Phys. Rev. Letts. 109, 107204 (2012).

Huang, Ssu-Yen

2013-03-01

152

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

PubMed

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 from each other with respect os sodium and chloride permeability. PMID:1133172

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

1975-06-01

153

Luminal and peritubular ionic substitutions and intracellular potential of the rabbit proximal convoluted tubule.  

PubMed

Transepithelial (psi T) and basolateral (psi BL) potential difference was measured in rabbit proximal convoluted tubules perfused in vitro. In control solution without protein, the mean psi BL was -54 +/- 2.2 mV (n = 57). Luminal substitution of K by Na had no effect. Complete luminal substitution of glucose and alanine, 110 mM substitution of Na or NaCl produced transient hyperpolarizations of psi BL of 14, 10, and 13 mV, respectively, with a return close to the control value within 4-8 min in all cases. Returning to control solution produced similar time-course transient depolarizations of psi BL of 17, 11, and 16 mV, respectively, again with a return to the control value in 4-10 min. Omission of glucose and alanine in the perfusate produced a decrease in cell volume of 14% that was maximal in 4 min with a complete recovery in the post-control period. A 110 mM luminal or peritubular substitution of Cl by cyclamate produced no significant effect on psi BL after taking into account the large psi T generated by the diffusion of Cl across the paracellular pathway. On the other hand, complete peritubular substitution of K by Na and 110 mM substitution of Na or NaCl produced sustained but reversible depolarizations of psi BL of 37.5, 10.2, and 20.4 mV, respectively. The transient nature of the hyperpolarization following luminal substitution of glucose, alanine, or Na can be interpreted in terms of changes in the intracellular sodium activity that would affect the Na-K-ATPase pump. Similarly, the sustained depolarization seen after a peritubular substitution of K and Na would also be compatible with a decrease in the basolateral ionic pump activity. PMID:6205598

Cardinal, J; Lapointe, J Y; Laprade, R

1984-08-01

154

Dual pathology proximal median nerve compression of the forearm.  

PubMed

We report an unusual case of synchronous pathology in the forearm- the coexistence of a large lipoma of the median nerve together with an osteochondroma of the proximal ulna, giving rise to a dual proximal median nerve compression. Proximal median nerve compression neuropathies in the forearm are uncommon compared to the prevalence of distal compression neuropathies (eg Carpal Tunnel Syndrome). Both neural fibrolipomas (Refs. 1,2) and osteochondromas of the proximal ulna (Ref. 3) in isolation are rare but well documented. Unlike that of a distal compression, a proximal compression of the median nerve will often have a definite cause. Neural fibrolipoma, also called fibrolipomatous hamartoma are rare, slow-growing, benign tumours of peripheral nerves, most often occurring in the median nerve of younger patients. To our knowledge, this is the first report of such dual pathology in the same forearm, giving rise to a severe proximal compression of the median nerve. In this case, the nerve was being pushed anteriorly by the osteochondroma, and was being compressed from within by the intraneural lipoma. This unusual case highlights the advantage of preoperative imaging as part of the workup of proximal median nerve compression. PMID:23707555

Murphy, Siun M; Browne, Katherine; Tuite, David J; O'Shaughnessy, Michael

2013-12-01

155

A 17 year old with isolated proximal tibiofibular joint arthritis  

PubMed Central

The proximal tibiofibular joint (TFJ) is rarely affected in rheumatic diseases, and we frequently interpret pain of the lateral knee as the result of overuse or trauma. Nonetheless, the TFJ is a synovial joint that communicates with the tibiofemoral joint in a proportion of patients. While proximal TFJ arthritis has been rarely associated with existing spondyloarthritis, isolated TFJ arthritis as the presenting manifestation of spondyloarthritis has not yet been described. Here, we report the clinical and radiographic presentation of an adolescent with chronic proximal TFJ arthritis heralding spondyloarthritis highly suggestive of ankylosing spondylitis. PMID:23302539

2013-01-01

156

Pointwise process proximity function calibration: PPFexplorer application results  

NASA Astrophysics Data System (ADS)

The semiconductor industry and mask shops spend great efforts in order to keep pace with the requirements on pattern fidelity of the ITRS lithography roadmap. Even for e-beam lithography - often referred to as technology with "unlimited" resolution - the challenges increase with shrinking feature sizes in combination with applicable resist processes. The pattern fidelity, specifically CD control, is crucial for the application of e-beam lithography. One aspect in CD control is the intrinsic proximity effect of the electron beam. This together with other contributions like influences from resist process or beam generation which are summarized altogether under the term process proximity effect have to be corrected. An accurate e-beam process proximity effect correction is therefore a key component of e-beam lithography. Some process proximity effect correction algorithms provide not only accurate correction for the process proximity effect induced pattern deformation but also optimize pattern contrast by adjusting geometry and dose simultaneously. However, the quality of the process proximity effect correction is limited by the calibration accuracy of the used model, i.e., the accuracy of the utilized process proximity function (PPF). In a previous paper [R. Galler et al, "PPF - Explorer: Pointwise Proximity Function calibration using a new radialsymmetric calibration structure", BACUS 2011] the PPF-explorer - a new experimental method for pointwise process proximity function calibration - was introduced and some first promising calibration results were shown. This paper presents the progress of the PPFexplorer proximity function calibration. This progress, among others, comprises automatic generation of calibration patterns, including pre-correction with respect to a rough forecast of the process proximity function to be calibrated. This pre-correction approach significantly reduces the number of necessary calibration structures and the number of measurement sites, without sacrificing calibration accuracy. On the contrary, the pre-correction has positive impact on the calibration quality, since it allows unifying the pattern contrast at the measurement sites, which reduces the SEM measurement induced error. We present the results of a PPFexplorer calibration with special focus on minimizing the number of measurement sites. The results show that the PPFexplorer method can help to improve the proximity effect model calibration with controllable efforts.

Krueger, M.; Banasch, M.; Galler, R.; Melzer, D.; Ramos, L. E.; Suelzle, M.; Weidenmueller, U.; Zeitner, U.

2012-02-01

157

Protein detection using proximity-dependent DNA ligation assays.  

PubMed

The advent of in vitro DNA amplification has enabled rapid acquisition of genomic information. We present here an analogous technique for protein detection, in which the coordinated and proximal binding of a target protein by two DNA aptamers promotes ligation of oligonucleotides linked to each aptamer affinity probe. The ligation of two such proximity probes gives rise to an amplifiable DNA sequence that reflects the identity and amount of the target protein. This proximity ligation assay detects zeptomole (40 x 10(-21) mol) amounts of the cytokine platelet-derived growth factor (PDGF) without washes or separations, and the mechanism can be generalized to other forms of protein analysis. PMID:11981560

Fredriksson, Simon; Gullberg, Mats; Jarvius, Jonas; Olsson, Charlotta; Pietras, Kristian; Gústafsdóttir, Sigrún Margrét; Ostman, Arne; Landegren, Ulf

2002-05-01

158

Modulation of variation by response-reward spatial proximity  

E-print Network

were paired with a hidden food reward with similar spatialfood, strengthen as a function of their proximity (spatial and/or temporal) to reward (reward probability, Stahlman and Blaisdell (2011a) trained rats to use landmarks to search for food

Leising, Kenneth J.; Ruprecht, Chad M.; Stahlman, W. David

2014-01-01

159

Computer vision based navigation for spacecraft proximity operations  

E-print Network

The use of computer vision for spacecraft relative navigation and proximity operations within an unknown environment is an enabling technology for a number of future commercial and scientific space missions. This thesis ...

Tweddle, Brent Edward

2010-01-01

160

The unified framework of some proximal-based decomposition ...  

E-print Network

Mar 22, 2010 ... ods and thus presents the unified framework of proximal-based decomposition ... Province NSF BK2008255, The Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China 708044.

2010-03-22

161

A Generalized Inexact Proximal Point Method for Nonsmooth ...  

E-print Network

and Kahneman [10] “loss aversion effect” in Psychology and Management. ... 2], a generalized proximal algorithm can modelize fairly well, in Psychology, ...... The more general case where hj ..... The Quarterly Journal of Economics, 108(3),.

2014-04-08

162

AN INEXACT PROXIMAL PATH-FOLLOWING ALGORITHM FOR ...  

E-print Network

joint treatment of proximal and self-concordant barrier concepts and illustrate that .... the optimality condition for (1.2) and then describe key technical results in deriving ...... Leukemia, where the GMRF sizes are p = 587 and 1255, respectively.

2013-11-07

163

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

164

Deleting the TGF-? Receptor Attenuates Acute Proximal Tubule Injury  

PubMed Central

TGF-? is a profibrotic growth factor in CKD, but its role in modulating the kidney’s response to AKI is not well understood. The proximal tubule epithelial cell, which is the main cellular target of AKI, expresses high levels of both TGF-? and its receptors. To determine how TGF-? signaling in this tubular segment affects the response to AKI, we selectively deleted the TGF-? type II receptor in the proximal tubules of mice. This deletion attenuated renal impairment and reduced tubular apoptosis in mercuric chloride–induced injury. In vitro, deficiency of the TGF-? type II receptor protected proximal tubule epithelial cells from hydrogen peroxide–induced apoptosis, which was mediated in part by Smad-dependent signaling. Taken together, these results suggest that TGF-? signaling in the proximal tubule has a detrimental effect on the response to AKI as a result of its proapoptotic effects. PMID:23160515

Vadivelu, Sangeetha; Neelisetty, Surekha; Srichai, Manakan B.; Paueksakon, Paisit; Pozzi, Ambra; Harris, Raymond C.

2012-01-01

165

Superconducting Proximity Effect in Single-Crystal Nanowires  

E-print Network

This dissertation describes experimental studies of the superconducting proximity effect in single-crystal Pb, Sn, and Zn nanowires of lengths up to 60 um, with both ends of the nanowires in contact with macroscopic electrodes that are either...

Liu, Haidong

2010-07-14

166

Radiation interchange modeling for active infrared proximity sensor design  

E-print Network

RADIATION INTERCHANGE MODELING FOR ACTIVE INFRARED PROXIMITY SENSOR DESIGN A Thesis by JAMES CLARICE PIPER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1999 Major Subject: Biomedical Engineering RADIATION INTERCI-IANGE MODELING FOR ACTIVE INFRARED PROXIMITY SENSOR DESIGN A Thesis by JAMES CLARICE PIPER Submitted to Texas A&M University in partial fulfillment...

Piper, James Clarice

2012-06-07

167

College Proximity and Rates of College Attendance1  

Microsoft Academic Search

This paper presents the results of a study on the effect of college proximity upon rates of college attendance among over 20,000 high school graduates of 1966 in the states of Illinois and North Carolina. Results of multivariate dummy-variable regression analyses question both the assumption that college proximity per se is an important factor in college-going, and the often stated

Vincent Tinto

1973-01-01

168

Receptor-mediated endocytosis in renal proximal tubule  

Microsoft Academic Search

Proteins filtered in renal glomeruli are removed from the tubular fluid by endocytosis in the proximal tubule mediated by\\u000a the two receptors megalin and cubilin. After endocytic uptake, the proteins are transferred to lysosomes for degradation,\\u000a while the receptors are returned to the apical cell membrane by receptor recycling in dense apical tubules. In the renal proximal\\u000a tubule, there is

Erik Ilsø Christensen; Pierre J. Verroust; Rikke Nielsen

2009-01-01

169

Intrinsic differences in various segments of the proximal convoluted tubule.  

PubMed

Until recently it has not been possible to compare directly the function of superficial and juxtamedullary nephrons. The present studies, using in vitro microperfusion, were designed to examine whether functional differences exist between proximal convoluted tubule segments of superficial and juxtamedullary nephrons. Electrophysiological studies showed that major differences exist between the relative chloride and sodium permeabilities of these segments. In the 1st mm of the superficial proximal convoluted tubule, the permeability to sodium was greater than that to chloride, whereas in the 2nd mm of the superficial proximal convoluted tubule and all later segments, the permeability to chloride was greater than that to sodium. The juxtamedullary proximal convoluted tubule was found to differ from the superficial proximal convoluted tubule in two respects: first, the relative permeabilities to chloride and sodium did not differ in the various segments of the juxtamedullary proximal convoluted tubule; second, the permeability to sodium was greater than to chloride throughout. When perfused with a solution lacking glucose and amino acids, the superficial and juxtamedullary convolutions exhibited the same transepithelial potential change, a reversible decrease to less than -- 1 mV. It thus appears that in both convolutions there exists electrogenic sodium transport coupled to the transport of these organic solutes. This differs from pars recta of both of these nephrons, which have been shown to exhibit electrogenic sodium transport independent of organic solutes. However, when perfused with a solution lacking glucose and amino acids but also containing high chloride and low bicarbonate concentrations, the superficial convolution developed a significantly more positive potential than the juxtamedullary. This difference reflects greater relative chloride permeability in the superficial proximal convolution. These studies show that intrinsic functional differences exist between proximal convoluted tubules obtained from the superficial and juxtamedullary nephron populations. PMID:947954

Jacobson, H R; Kokko, J P

1976-04-01

170

Intrinsic differences in various segments of the proximal convoluted tubule.  

PubMed Central

Until recently it has not been possible to compare directly the function of superficial and juxtamedullary nephrons. The present studies, using in vitro microperfusion, were designed to examine whether functional differences exist between proximal convoluted tubule segments of superficial and juxtamedullary nephrons. Electrophysiological studies showed that major differences exist between the relative chloride and sodium permeabilities of these segments. In the 1st mm of the superficial proximal convoluted tubule, the permeability to sodium was greater than that to chloride, whereas in the 2nd mm of the superficial proximal convoluted tubule and all later segments, the permeability to chloride was greater than that to sodium. The juxtamedullary proximal convoluted tubule was found to differ from the superficial proximal convoluted tubule in two respects: first, the relative permeabilities to chloride and sodium did not differ in the various segments of the juxtamedullary proximal convoluted tubule; second, the permeability to sodium was greater than to chloride throughout. When perfused with a solution lacking glucose and amino acids, the superficial and juxtamedullary convolutions exhibited the same transepithelial potential change, a reversible decrease to less than -- 1 mV. It thus appears that in both convolutions there exists electrogenic sodium transport coupled to the transport of these organic solutes. This differs from pars recta of both of these nephrons, which have been shown to exhibit electrogenic sodium transport independent of organic solutes. However, when perfused with a solution lacking glucose and amino acids but also containing high chloride and low bicarbonate concentrations, the superficial convolution developed a significantly more positive potential than the juxtamedullary. This difference reflects greater relative chloride permeability in the superficial proximal convolution. These studies show that intrinsic functional differences exist between proximal convoluted tubules obtained from the superficial and juxtamedullary nephron populations. PMID:947954

Jacobson, H R; Kokko, J P

1976-01-01

171

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

PubMed Central

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. PMID:24531551

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; Deschenes, Isabelle; Ficker, Eckhard; Schelling, Jeffrey R.

2014-01-01

172

Ejecta emplacement: from distal to proximal  

NASA Astrophysics Data System (ADS)

Introduction Most part of impact ejecta is deposited ballistically at some distance from a crater, defined by ejection velocity V and ejection angle ?: d=v2sin?/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 liquid with specific properties, i.e. finite-difference equations are the same as in standard hydrodynamics [6-8]. Another approach is based on solving equations of motion for representative particles [9]. Each of these markers describes the motion of a large number of real particles with similar sizes, velocities, and trajectories. Equation of motion (gravity, viscosity, and drag) is solved for every marker and then exchange of momentum, heat and energy with surrounding vaporair mixture is taken into account. This approach is used in the SOVA code [10] and allows to vary particle sizes within a broad range (from a few m to a few microns). Implicit procedure of velocity update allows a larger time step. The substantial advantage of the model is its three-dimensional geometry, allowing modeling of asymmetric deposits of oblique impact ejecta. Turbulent diffusion is taken into account in a simplified manner [6]. Fragments size-frequency distribution (SFD) may be of crucial importance: while large fragments move ballistically, the smallest ones are passively involved in gas motion. Ejected material is usually transformed into particles under tension. The initial particle velocity is given by the hydrodynamic velocity, but the object's initial position within the cell is randomly defined. The SFD of solid fragments in high velocity impacts has been studied experimentally [2,11], numerically [12,13], and has been derived from the lunar and terrestrial crater observations [14,15]. Various approaches may be used to implement fragment size in a dynamic model: in Grady-Kipp model the average fragment size is defined by strain rate [12]; alternatively, average ejection velocity [16] or maximum shock compression [17] may be used. All methods may be verified through comparison with known data. Volcanic direct blast. Numerical modeling of pyroclastic flows, checked against recent observations and young deposits, may be then a useful instrument for reconstruction of terrestrial craters' ejecta, which are mostly eroded or buried; and for impact ejecta study on other planets

Artemieva, N.

2008-09-01

173

Predictive factors of proximal advanced neoplasia in the large bowel  

PubMed Central

Introduction The aim of the study was to evaluate the impact of sex, age, family history and distal findings on the risk of proximal advanced neoplasia (cancer or advanced adenoma) in the large bowel. Material and methods Records for 10 111 asymptomatic participants of the Colonoscopy Screening Program (CSP), recruited from the Warsaw region between 2000 and 2004, were analyzed. A multivariate logistic regression model was used to estimate the impact of sex, age, family history and most advanced distal lesions on the occurrence of proximal advanced neoplasia. To enhance comparability of the study two definitions of the proximal colon were applied – either the splenic flexure (1st) or the bend between the descending and sigmoid colon (2nd definition) represented the boundary. Results One hundred and thirty-three (1st) and 167 patients (2nd definition) were found to have at least one advanced neoplastic lesion in the proximal part, respectively. Eleven and 14 patients were found to have carcinoma, while in 130 and 163 patients at least one proximal advanced adenoma appeared. Men were at twice as high risk of having advanced neoplasia in the proximal colon than women (OR = 1.94, 95% CI: 1.31–2.87, p = 0.001 or OR = 1.69, 95% CI: 1.20–2.40, p = 0.003, respectively). The presence of distal advanced neoplastic lesions was associated with 3.5 times higher risk of proximal advanced neoplasia (OR = 3.58, 95% CI: 2.00–6.43, p < 0.0001 or OR = 3.41, 95% CI: 1.95–5.96, p < 0.0001), respectively. Conclusions The results may confirm some limitation of flexible sigmoidoscopy in the screening settings in comparison with colonoscopy, at least in men and people with distal advanced neoplasia. PMID:25097578

Mroz, Andrzej; Kaminski, Michal F.; Kraszewska, Ewa; Orlowska, Janina; Regula, Jaroslaw

2014-01-01

174

Subcellular localization of tobramycin and vancomycin given alone and in combination in proximal tubular cells, determined by immunogold labeling.  

PubMed Central

The subcellular localization of tobramycin and vancomycin in the renal cortices of rats was determined with ultrathin sections by immunogold labeling. Four groups of four rats each were treated for 10 days with saline (NaCl, 0.9%), tobramycin at dosages of 20 mg/kg of body weight per 12 h intraperitoneally, vancomycin at dosages of 25 mg/kg/12 h subcutaneously, or the combination tobramycin-vancomycin. On day 11, the animals were killed, and cubes of renal cortex were fixed overnight in phosphate-buffered glutaraldehyde (0.5%), dehydrated in ethanol, and embedded in Araldite 502 resin. Ultrathin sections were made and incubated with sheep antitobramycin antibody followed by protein A-gold (15-nm diameter) complex or rabbit antivancomycin antibody followed by gold (30-nm diameter)-labeled goat anti-rabbit antibody. For the double labeling, incubations were made on opposite sides of the grid. Tobramycin was detected over the lysosomes of proximal tubular cells, but the labeling was concentrated into small areas in the matrix of the lysosomes. Vancomycin was seen over the lysosomes of proximal tubular cells and was distributed uniformly throughout the matrix of the lysosomes. In rats treated with tobramycin-vancomycin, both drugs were still detected in lysosomes of proximal tubular cells. It is concluded that tobramycin and vancomycin accumulate in lysosomes of proximal tubular cells throughout 10 days of treatment and that vancomycin has no effect on the subcellular distribution of tobramycin. Images PMID:1444301

Beauchamp, D; Gourde, P; Simard, M; Bergeron, M G

1992-01-01

175

Isolated perfused salamander proximal tubule. II. Monovalent ion replacement and rheogenic transport.  

PubMed

Early proximal tubules of the salamander kidney (Ambystoma tigrinum) were isolated and perfused in vitro. Transepithelial and basolateral electrical potential differences, transepithelial resistances, and intracellular ionic activities were measured during removal of Na+, K+, or Cl- from the lumen, the bath, or both lumen and bath. The effects of these external ionic replacements are interpreted in terms of an equivalent circuit that represents the renal epithelium as a network of passive ionic resistances, ionic diffusion potentials, and active transport current sources. Results indicate that rheogenic transport across the basolateral membrane is substantially diminished by removal of Na+ from either lumen or bath or by removal of K+ from the bath. On the other hand, bilateral chloride removal produces an increase in transepithelial resistance but almost no change in the calculated rate of basolateral rheogenic transport. This suggests that the source of the basolateral rheogenic ion flux ia a Na-K-ATPae that actively transports an excess of outward Na+ over inward K+. PMID:7304748

Sackin, H; Boulpaep, E L

1981-11-01

176

Orthopaedic Approaches to Proximal Humeral Fractures Following Trauma  

PubMed Central

Proximal humeral fractures have been a topic of discussion in medical literature dating back as far as 3rd century BC. Today, these fractures are the most common type of humeral fractures and account for about 5-6% of all fractures in adults with the incidence rising rapidly with age. In broad terms the management of proximal humeral fractures can be divided into two categories: conservative versus surgical intervention. The aim of treatment is to stabilize the fracture, aid better union and reduce pain during the healing process. Failure to achieve this can result in impairment of function, and significantly weaken the muscles inserting onto the proximal humerus. With the rising incidence of proximal humeral fractures, especially among the elderly, the short and long term burden for patients as well as the wider society is increasing. Furthermore, there is a lack of consistency in the definitive treatment and management of displaced fractures. This systematic review of literature compares the surgical treatment of proximal humeral fractures with their conservative management, by evaluating the available randomised controlled trials on this topic. PMID:25408786

Mafi, Reza; Khan, Wasim; Mafi, Pouya; Hindocha, Sandip

2014-01-01

177

Common relationships among proximate composition components in fishes  

USGS Publications Warehouse

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.

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

2008-01-01

178

Reverse geometry shoulder replacement for proximal humeral metastases.  

PubMed

The management of skeletal metastases can be challenging for the orthopaedic surgeon. They represent a significant source of pain and disability for cancer patients, adding to the morbidity of their condition. Treatment is directed at the alleviation of symptoms and the restoration of function. Metastatic involvement of the proximal humerus can be especially debilitating, having the potential to cause severe pain and loss of function. We present a report of three such cases where reverse geometry proximal shoulder replacement was used to provide a pain free functional range of movement in patients with concomitant rotator cuff disease. In all cases, significant symptomatic relief was achieved postoperatively with preservation of upper limb function. No surgical complications were noted. It is our belief that this novel surgical strategy provides a valuable and effective option for the management of proximal humeral metastatic disease in the rotator cuff deficient patient. PMID:25245723

Kapur, R A; McCann, P A; Sarangi, P P

2014-10-01

179

Comparison of different proximity potentials for asymmetric colliding nuclei  

SciTech Connect

Using the different versions of phenomenological proximity potential as well as other parametrizations within the proximity concept, we perform a detailed comparative study of fusion barriers for asymmetric colliding nuclei with asymmetry parameter as high as 0.23. In all, 12 different proximity potentials are robust against the experimental data of 60 reactions. Our detailed study reveals that the surface energy coefficient as well as radius of the colliding nuclei depend significantly on the asymmetry parameter. All models are able to explain the fusion barrier heights within +-10% on the average. The potentials due to Bass 80, AW 95, and Denisov DP explain nicely the fusion cross sections at above- as well as below-barrier energies.

Dutt, Ishwar; Puri, Rajeev K. [Department of Physics, Panjab University, Chandigarh 160014 (India)

2010-06-15

180

Computer Aided Proximity Effect Correction System in Photolithography  

NASA Astrophysics Data System (ADS)

Reflected light from step coverage causes fatal pattern defects in photolithography. The resist pattern defects are caused by the extra exposure from the highly reflective stepped substrate, such as breaks in the pattern of the aluminum layer. The problem is significant when the patterns in the different layers are near each other. We named this problem the proximity effect. The specific design rules such as the space between the resist pattern and the steps on the substrate are evaluated by simulation and experiment. Based on the evaluated results, we propose a computer aided proximity effect correction system to verify the pattern layout and eliminate the proximity effect. The effectiveness of the system is confirmed experimentally.

Hirai, Yoshihiko; Nomura, Noboru; Misaka, Akio; Hayama, Shigeru; Yamashita, Kazuhiro; Harafuji, Kenji

1989-10-01

181

A Flexible Proximity Sensor Fully Fabricated by Inkjet Printing  

PubMed Central

A flexible proximity sensor fully fabricated by inkjet printing is proposed in this paper. The flexible proximity sensor is composed of a ZnO layer sandwiched in between a flexible aluminum sheet and a web-shaped top electrode layer. The flexible aluminum sheet serves as the bottom electrode. The material of the top electrode layer is nano silver. Both the ZnO and top electrode layers are deposited by inkjet printing. The fully inkjet printing process possesses the advantages of direct patterning and low-cost. It does not require photolithography and etching processes since the pattern is directly printed on the flexible aluminum sheet. The prototype demonstrates that the presented flexible sensor is sensitive to the human body. It may be applied to proximity sensing or thermal eradiation sensing. PMID:22399923

Wang, Chin-Tsan; Huang, Kuo-Yi; Lin, David T. W.; Liao, Wei-Chia; Lin, Hua-Wei; Hu, Yuh-Chung

2010-01-01

182

Operative treatment of stress fractures of the proximal second metatarsal.  

PubMed

Proximal stress fractures of the second metatarsal are rare. They have been reported mainly in classical ballet dancers. Non-operative treatment has usually led to good results and rapid return to full activities. We present a series of nine cases with stress fractures of the proximal second metatarsal. The patients were all actively involved in sports. None of them were dancers. In all of these patients non-operative treatment lasting for an average of 13 months had failed. All of the patients were operated on using the same method. In the operation drilling was performed around and through the fracture line. The patients were followed for an average of 38 months. All except one of the patients were able to return to their prior level of activity within 4-6 months. In conclusion if non-operative treatment fails surgery seems to give good results in most patients with a stress fracture of the proximal second metatarsal. PMID:17181771

Sarimo, J; Orava, S; Alanen, J

2007-08-01

183

Chromatin in situ proximity (ChrISP): single-cell analysis of chromatin proximities at a high resolution.  

PubMed

Current techniques for analyzing chromatin structures are hampered by either poor resolution at the individual cell level or the need for a large number of cells to obtain higher resolution. This is a major problem as it hampers our understanding of chromatin conformation in single cells and how these respond to environmental cues. Here we describe a new method, chromatin in situ proximity (ChrISP), which reproducibly scores for proximities between two different chromatin fibers in 3-D with a resolution of ~170Å in single cells. The technique is based on the in situ proximity ligation assay (ISPLA), but ChrISP omits the rolling circle amplification step (RCA). Instead, the proximities between chromatin fibers are visualized by a fluorescent connector oligonucleotide DNA, here termed splinter, forming a circular DNA with another circle-forming oligonucleotide, here termed backbone, upon ligation. In contrast to the regular ISPLA technique, our modification enables detection of chromatin fiber proximities independent of steric hindrances from nuclear structures. We use this method to identify higher order structures of individual chromosomes in relation to structural hallmarks of interphase nuclei and beyond the resolution of the light microscope. PMID:24641475

Chen, Xingqi; Shi, Chengxi; Yammine, Samer; Göndör, Anita; Rönnlund, Daniel; Fernandez-Woodbridge, Alejandro; Sumida, Noriyuki; Widengren, Jerker; Ohlsson, Rolf

2014-01-01

184

Proximal Tibia Osteoarticular Allografts in Tumor Limb Salvage Surgery  

Microsoft Academic Search

Background  Resection of large tumors of the proximal tibia may be reconstructed with endoprostheses or allografts with fixation. Endoprosthetic\\u000a replacement is associated with high failure rates and complications. Proximal tibia osteoarticular allografts after tumor\\u000a resection allows restoration of bone stock and reconstruction of the extensor mechanism, but the long-term failure rates and\\u000a complications are not known.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We therefore determined (1) the

D. Luis Muscolo; Miguel A. Ayerza; German Farfalli; Luis A. Aponte-Tinao

2010-01-01

185

An experiment in manipulator control with proximity sensors  

NASA Technical Reports Server (NTRS)

Optical proximity sensors were used in a feedback loop to automatically position a manipulator hand for grasping. The experiment was a simplified one, involving two dimensional motion only. Two proximity sensors were mounted on the hand, and control signals derived from their outputs were used to drive the hand vertically and horizontally. The sensors employ a pulsed gallium arsenide light-emitting diode together with a silicon detector. They indicate, without contact, the approximate distance between the manipulator hand and object in the range from 5 to 12 cm. Positioning within approximately + or - 5 mm was observed. Extension of the technique to general three-dimensional control is briefly discussed.

Johnston, A. R.

1974-01-01

186

Inverse Proximity Effect in Superconductor-Ferromagnet Bilayer Structures  

NASA Astrophysics Data System (ADS)

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 induces a finite magnetization in the superconducting 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. [Phys. Rev. BPRBMDO0163-1829 69, 174504 (2004)]10.1103/PhysRevB.69.174504.

Xia, Jing; Shelukhin, V.; Karpovski, M.; Kapitulnik, A.; Palevski, A.

2009-02-01

187

Longitudinal Spin Seebeck Effect Free from the Proximity Nernst Effect  

NASA Astrophysics Data System (ADS)

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/Y3Fe5O12 (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.

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

2013-02-01

188

Inverse Proximity Effect in Superconductor-ferromagnet Bilayer Structures  

SciTech Connect

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].

Xia, Jing

2010-04-05

189

Ectrodactyly and proximal/intermediate interstitial deletion 7q  

SciTech Connect

We report on an individual with severe mental retardation, seizures, microcephaly, unusual face, scoliosis, and cleft feet and cleft right hand. The chromosomal study showed a proximal interstitial deletion 7q (q11.23q22). From our review of the literature, 11 patients have been reported with ectrodactyly (split hand/split foot malformation) and proximal/intermediate interstitial deletions or rearrangements of 7q. The critical segment for ectrodactyly seems to be located between 7q21.2 and 7q22.1. This malformation is present in 41% of the patients whose deletion involves the critical segment. 37 refs., 3 figs., 1 tab.

McElveen, C.; Carvajal, M.V.; Moscatello, D. [Louisiana State Univ. Medical Center, New Orleans, LA (United States)] [and others

1995-03-13

190

Volume Reabsorption, Transepithelial Potential Differences, and Ionic Permeability Properties in Mammalian Superficial Proximal Straight Tubules  

PubMed Central

This paper describes experiments designed to evaluate Na+ and Cl- transport in isolated proximal straight tubules from rabbit kidneys. When the perfusing solution was Krebs-Ringer buffer with 25 mM HCO3- (KRB) and the bath contained KRB plus 6% albumin, net volume reabsorption (Jv, nl min-1 mm-1 was -0.46 ± 0.03 (SEM); Ve, the spontaneous transepithelial potential difference, was -1.13 ± 0.05 mV, lumen negative. Both Jv, and Ve, were reduced to zero at 21°C or with 10-4 M ouabain, but Jv, was not HCO3- dependent. Net Na+ reabsorption, measured as the difference between 22Na+ fluxes, lumen to bath and bath to lumen, accounted quantitatively for volume reabsorption, assuming the latter to be an isotonic process, and was in agreement with the difference between lumen to bath 22Na+ fluxes during volume reabsorption and at zero volume flow. The observed flux ratio for Na+ was 1.46, and that predicted for a passive process was 0.99; thus, Na+ reabsorption was rationalized in terms of an active transport process. The Cl- concentration of tubular fluid rose from 113.6 to 132.3 mM during volume reabsorption. Since Ve, rose to +0.82 mV when tubules were perfused with 138.6 mM Cl- solutions, Ve may become positive when tubular fluid Cl- concentrations rise during volume reabsorption. The permeability coefficients PNa and PCl computed from tracer fluxes were, respectively, 0.23 x 10-4 and 0.73 x 10-4 cm s-1. A PNa/PCl ratio of 0.3 described NaCl dilution potentials at zero volume flow. The magnitudes of the potentials were the same for a given NaCl gradient in either direction and PNa/PCl was constant in the range 32–139 mM NaCl. We infer that the route of passive ion permeation was through symmetrical extracellular interfaces, presumably tight junctions, characterized by neutral polar sites in which electroneutrality is maintained by mobile counterions. PMID:4443793

Schafer, James A.; Troutman, Susan L.; Andreoli, Thomas E.

1974-01-01

191

Enterprise mobile applications based on presence and logical proximity  

Microsoft Academic Search

A method and application architecture are proposed for improving the sharing of presence and other information between mobile clients and enterprise servers by determining, in a hybrid peer-to-peer (P2P) network based on logical proximity, when a mobile client should share data with other peers in a group, instead of transmitting data to the servers. A \\

Xueshan Shan; Alok Shriram

2006-01-01

192

Nonacidotic proximal tubulopathy transmitted as autosomal dominant trait  

Microsoft Academic Search

The family of a patient with a nonacidotic and hypercalciuric proximal tubulopathy was studied. The proband showed glycosuria, aminoaciduria, tubular proteinuria, renal hypophosphatemia, and urate tubular hyporeabsorption without bicarbonate loss. He also presented increased urine calcium excretion, plasma 1,25-dihydroxyvitamin D, and enteral calcium absorption. Clinical consequences of the tubulopathy were osteopenia and calcium kidney stones. Fifteen of the proband's relatives

Giuseppe Vezzoli; Simona Zerbi; Ivano Baragetti; Laura Soldati; Stefano Mora; Giacomo Dell'Antonio; Giuseppe Bianchi

1997-01-01

193

Proximity to coast is linked to climate change belief.  

PubMed

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

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

2014-01-01

194

Evolutionary sport and exercise psychology: Integrating proximate and ultimate explanations  

E-print Network

Review Evolutionary sport and exercise psychology: Integrating proximate and ultimate explanations, Dalhousie University, Halifax, Nova Scotia, Canada b Department of Kinesiology and Physical Education differences Sport participation Physical activity a b s t r a c t Objectives: This review aims to demonstrate

Schulte-Hostedde, Albrecht

195

The impact of grandparental proximity on maternal childcare in China  

Microsoft Academic Search

This paper investigates the impact of the proximity of grandparents' residence on mother's childcare involvement in contemporary China. Drawing on data from the 1991 China Health and Nutrition Survey, we find that the presence of grandparents in the household significantly reduces a mother's involvement in childcare. Nearby residence of grandparents also decreases mothers' childcare involvement, but only in the case

Feinian Chen; Susan E. Short; Barbara Entwisle

2000-01-01

196

Metastatic transitional cell carcinoma in proximal humerus of a dog  

PubMed Central

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

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

2011-01-01

197

A study of proximity focusing RICH with aerogel radiator  

Microsoft Academic Search

Proximity focusing RICH based on an aerogel Cherenkov radiator has been developed for a new particle identifier in the Belle upgrade. To further improve the detector performance, a new concept for Cherenkov ring imaging has been introduced, where multiple aerogel layers with different indices are accumulated to increase observed photoelectrons without making the single photon resolution worse. By constructing a

I. Adachi; K. Fujita; T. Fukushima; A. Gorisek; D. Hayashi; T. Iijima; T. Ikado; T. Ishikawa; H. Kawai; S. Korpar; Y. Kozakai; P. Krizan; A. Kuratani; Y. Mazuka; T. Nakagawa; S. Nishida; S. Ogawa; R. Pestotnik; T. Seki; T. Sumiyoshi; M. Tabata; Y. Unno

2007-01-01

198

Arterial blood supply of the proximal humeral epiphysis  

Microsoft Academic Search

The arterial blood supply of the proximal humeral epiphysis is known to derive mainly from the anterior humeral circumflex a. (ACA), but this description may minimize the role of the posterior circumflex humeral a. (PCA). The studies of Laing [9] and Gerber [3] emphasized the role of the ACA and of its branches, the ascending anterolateral artery and arcuate artery

F. Duparc; J.-M. Muller; P. Frçger

2001-01-01

199

[A case of priapism of the proximal corpora cavernosa].  

PubMed

A young man presented with a little perineal mass that was found to be secondary to partial priapism of the proximal corpora cavernosa. This is a very rare condition with only 3 previously recorded cases in the urology literature. The patient made a good recovery and was able to resume sexual activity. PMID:8322115

De Zan, A; Gamba, P; Piana, P; Squintone, L; Vottero, M; Tizzani, A

1993-03-01

200

The physiology of the female orgasm as a proximate mechanism  

Microsoft Academic Search

The dynamics of female orgasms were investigated and proposed as a possible proximate mechanism implicated in female mating strategies. Specifically, the role of female orgasm in motivating women to engage in sexual relations while refraining from engaging indiscriminately in one-night stands (ONS) was explored. A total of 202 Western women of reproductive age were surveyed about their sexual behaviour, practices,

Lara Eschler

2004-01-01

201

Zone of Proximal Development and the World of the Child.  

ERIC Educational Resources Information Center

This paper examines Lev Vygotsky's theory concerning the zone of proximal development (ZPD) in children and its relevance to early childhood education. As per Vygotsky's "Mind in Society" (1978), ZPD is the difference between a child's "actual development level as determined by independent problem solving" and the "potential development as…

Seng, Seok-Hoon

202

Reconstruction of the extensor mechanism after proximal tibia endoprosthetic replacement  

Microsoft Academic Search

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

Jacob Bickels; James C. Wittig; Yehuda Kollender; Robert S. Neff; Kristen Kellar-Graney; Isaac Meller; Martin M. Malawer

2001-01-01

203

Proximity of Clothing to Self: Evolution of a Concept  

Microsoft Academic Search

Proximity of clothing to self is a multifaceted concept conceived as the psychological closeness of clothing to self and indicated by the extent to which clothing is (1) perceived as one with the self or as a component of the self, (2) recognized as an aspect of appearance by which the self is established and validated, (3) recognized as a

M. Suzanne Sontag; Jean Davis Schlater

1982-01-01

204

Fracture through a geode in the proximal ulna.  

PubMed

Chronic joint pain in rheumatoid arthritis may mask that from other causes. Stress fractures, particularly in osteoporotic lower limb bones of such patients, are well described but can still cause diagnostic difficulty. These difficulties were highlighted by a case in which an unusual fracture occurred through a geode in the proximal ulna mimicking an exacerbation of synovitis in the elbow joint. PMID:6722411

Wordsworth, B P; Mowat, A G; Watson, N A

1984-05-01

205

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

PubMed

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. PMID:21920651

Schafer, Markus H; Ferraro, Kenneth F

2011-11-01

206

Reproductive skew in female common marmosets: what can proximate mechanisms  

E-print Network

Review Reproductive skew in female common marmosets: what can proximate mechanisms tell us about of Obstetrics and Gynecology, and 5 Endocrinology-Reproductive Physiology Training Program, University 27708, USA Common marmosets are cooperatively breeding monkeys that exhibit high reproductive skew: most

Saltzman, Wendy

207

Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers  

E-print Network

Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers David L. Carr are significantly associated at the global and regional scales, evidence for population links to deforestation of thought on population­environment theories relevant to deforestation in tropical agricultural frontiers

Lopez-Carr, David

208

Residential proximity to gasoline service stations and preterm birth.  

PubMed

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. PMID:23625119

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

2013-10-01

209

Constructing proximity: Relating to readers in popular and professional science  

Microsoft Academic Search

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 which display both authority as an expert

Ken Hyland

2010-01-01

210

Constructing Proximity: Relating to Readers in Popular and Professional Science  

ERIC Educational Resources Information Center

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…

Hyland, Ken

2010-01-01

211

Special characteristics of osteoid osteoma in the proximal phalanx.  

PubMed

We report two cases of osteoid osteoma in the proximal phalanx. This is an uncommon location for the lesion and it has special clinical and radiological features. Both cases were successfully treated when an 'en bloc' excision of the lesion, including the nidus, was performed. Four operations were required in the first case. PMID:9457591

Soler, J M; Pizà, G; Aliaga, F

1997-12-01

212

Scaffolding Critical Thinking in the Zone of Proximal Development  

ERIC Educational Resources Information Center

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.…

Wass, Rob; Harland, Tony; Mercer, Alison

2011-01-01

213

Sharpening a Tool for Teaching: The Zone of Proximal Development  

ERIC Educational Resources Information Center

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…

Wass, Rob; Golding, Clinton

2014-01-01

214

Passively safe Receding Horizon Control for satellite proximity operations  

Microsoft Academic Search

Recent on-orbit mission performance illustrates a pressing need to develop passively safe formation flight trajectories and controllers for multiple satellite proximity operations. A receding horizon control (RHC) approach is formulated that directly relates navigation uncertainty and process noise to non-convex quadratic constraints, which enforce passive safety in the presence of a large class of navigation or propulsion system failures. Several

Marcus Holzinger; Jeremiah Dimatteo; Jeremy D. Schwartz; Mark Milam

2008-01-01

215

Ontology-based proximity search Tuan M.V. Le  

E-print Network

general open source for ontology-based information retrieval to answer queries that involve named entities search engines that exploit the ontology features of named entities in proximity search and develop an algorithm for computing dynamic distances between named entities and keywords in queries and documents

Cho, Junghoo "John"

216

CFN Operations and Safety Awareness (COSA) Checklist Proximal Probes Facility  

E-print Network

Gas TQ-COMPGAS-1 X X X X Cryogen Safety HP-OSH-25 X X X X Electrical Safety for Benchtop Workers TQ: No work on exposed parts above 50V without Electrical Safety 1 Training and Dept. ES&H approval FurtherCFN Operations and Safety Awareness (COSA) Checklist Proximal Probes Facility Building 735

Ohta, Shigemi

217

Triplet Supercurrents in Half Metals and Unconventional Proximity Effects  

E-print Network

-wave') Spin-unpolarized Spin-polarized (for constant singlet order parameter) #12;Effect of disorder constant All induced triplet components at surface stay unaffected by disorder! All what changes proximity effect in S/Half-Metal Junctions Effect of disorder, s-wave and p-wave triplets Josephson effect

Fominov, Yakov

218

Impact of Relational Proximity on Distress from Infidelity  

Microsoft Academic Search

Men are generally more distressed by a partner's sexual infidelity whereas women are generally more distressed by a partner's emotional infidelity. The importance of the identity of the interloper, however, has been neglected. We explored the influence of relational proximity (i.e., the degree of genetic relatedness) on distress about infidelity. In Study 1, participants were most distressed when the imagined

Maryanne Fisher; Glenn Geher; Ulrich S. Tran; Ashley Hoben; Andrew Arrabaca; Corinna Chaize; Robert Dietrich; Martin Voracek

219

Ramsey partitions and proximity data structures Manor Mendel  

E-print Network

Ramsey partitions and proximity data structures Manor Mendel The Open University of Israel mendelma is best possible and improves part of the metric Ramsey theorem of Bartal, Linial, Mendel and Naor [5 version available at http://arxiv.org/ abs/cs/0511084. Part of this work was carried out while M. Mendel

Naor, Assaf

220

Proximity interactions between wireless sensors and their application  

Microsoft Academic Search

Many applications in ubiquitous computing rely on knowing where people and objects are relative to each other. By placing small wireless sensors on people, at specific locations, and on or in a wide variety of everyday objects we can collect these proximate relationships and deduce much about a person's or an object's context. This paper investigates the practical issues of

Waylon Brunette; Carl Hartung; Ben Nordstrom; Gaetano Borriello

2003-01-01

221

Percutaneous Bipolar Radiofrequency Microdebridement for Recalcitrant Proximal Plantar Fasciosis  

Microsoft Academic Search

Success rates for traditional methods of surgical intervention for chronic plantar fasciosis are low, and associated with high rates of complications and long recovery times. The purpose of this prospective case series was to assess the effectiveness of percutaneous bipolar radiofrequency microfasciotomy for the treatment of recalcitrant proximal plantar fasciosis in 21 patients. The mean preoperative American Orthopaedic Foot &

Matthew D. Sorensen; Christopher F. Hyer; Terrence M. Philbin

2011-01-01

222

Determination of chloride and bicarbonate permeabilities in proximal convoluted tubules.  

PubMed

In late proximal tubules volume reabsorption linked to passive ion flows relies on the existence of differing permeability coefficients to Cl- and HCO3(-) (PCl greater than PHCO3). We measured these permeability coefficients in late segments of rabbit superficial (SFPCT) and juxtamedullary (JMPCT) proximal convoluted tubules perfused in vitro. PHCO3 and P36Cl were determined in tubules bathed in rabbit serum and perfused with a serum ultrafiltrated titrated with H2SO4 to [HCO3(-)] of 4 mM. Active transport, transepithelial voltage, and HCO3(-) reabsorption were inhibited by cooling (21 degrees C) and 10(-4) M acetazolamide. P36Cl and PHCO3 were calculated from 36Cl disappearance from and total CO2 addition to the perfusate. P36Cl in SFPCT was twice that in JMPCT but PHCO3 was the same in both segments. P36Cl exceeded PHCO3 only in SFPCT. To exclude exchange diffusion from contributing to P36Cl, additional tubules were perfused with ultrafiltrate titrated with HCl.P36Cl and simultaneously measured PCl (lumen-to-bath net chemical Cl- flux) were identical. We conclude: 1) SFPCT and JMPCT are heterogeneous with respect to Cl- permeability; 2) relative Cl--to-HCO3(-) permeabilities predict that anion gradients present in late portions of proximal tubules would support more volume reabsorption linked to passive ion flows in SF than in JMPCT; 3) no significant Cl- exchange diffusion exists in proximal tubules. PMID:7315963

Holmberg, C; Kokko, J P; Jacobson, H R

1981-10-01

223

Technique for temperature compensation of eddy-current proximity probes  

NASA Technical Reports Server (NTRS)

Eddy-current proximity probes are used in turbomachinery evaluation testing and operation to measure distances, primarily vibration, deflection, or displacment of shafts, bearings and seals. Measurements of steady-state conditions made with standard eddy-current proximity probes are susceptible to error caused by temperature variations during normal operation of the component under investigation. Errors resulting from temperature effects for the specific probes used in this study were approximately 1.016 x 10 to the -3 mm/deg C over the temperature range of -252 to 100 C. This report examines temperature caused changes on the eddy-current proximity probe measurement system, establishes their origin, and discusses what may be done to minimize their effect on the output signal. In addition, recommendations are made for the installation and operation of the electronic components associated with an eddy-current proximity probe. Several techniques are described that provide active on-line error compensation for over 95 percent of the temperature effects.

Masters, Robert M.

1989-01-01

224

Efficient Private Proximity Testing with GSM Location Sketches  

E-print Network

's location. Due to the need to perform privacy-preserving threshold set in- tersection, their scheme the proliferation of smart- phones and online social networking sites. Equipped with GPS receivers and/or base. Hopper of users. As a result, a variety of "privacy-preserving" proximity tests have been pro- posed

Minnesota, University of

225

Science Teachers' Conceptual Growth within Vygotsky's Zone of Proximal Development.  

ERIC Educational Resources Information Center

Examines how science teachers' (n=14) knowledge of science and science pedagogy changed after participation in a constructivist-based methods course. More-experienced teachers were paired with less-experienced teachers, and pre- and post-instructional concept maps, journals, portfolios, and transcripts revealed that, within the zone of proximal

Jones, M. Gail; Rua, Melissa J.; Carter, Glenda

1998-01-01

226

Theory of Proximity Effect in Junctions with Unconventional Superconductors  

E-print Network

Theory of Proximity Effect in Junctions with Unconventional Superconductors Relevance to odd superconductor Quasiparticles feel different signs of the pair potential depending on direction of their motion electron hole electron like quasiparticle hole like quasiparticle Mid gap Andreev resonant state (MARS

Fominov, Yakov

227

On the Surprising Salience of Curvature in Grouping by Proximity  

ERIC Educational Resources Information Center

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…

Strother, Lars; Kubovy, Michael

2006-01-01

228

Proximate nutritive value changes during decomposition of salt marsh plants  

Microsoft Academic Search

Recognition of salt marsh plant detritus as a nutritious source of food for estuarine consumers prompted investigation of in situ decomposition and proximate nutritive values of three plants and their detritus namely: Spartina cynosuroides and Distichlis spicata (Gramineae) and Scirpus americanus (Cyperaceae) growing abundantly in Mississippi tidal marshes. During decomposition to particulate detritus, these plants retain 60–70% organic content and

Armando A. Cruz

1975-01-01

229

Connectivity of Cognitive Radio Networks: Proximity vs. Opportunity  

E-print Network

Connectivity of Cognitive Radio Networks: Proximity vs. Opportunity Wei Ren and Qing Zhao Dept the connectivity of large-scale ad hoc cognitive radio networks, where secondary users exploit channels temporarily General Terms Algorithms, Design, Theory Keywords Cognitive radio, connectivity, continuum percolation 1

Islam, M. Saif

230

Proximal Positioning: A Strategy of Practice in Violin Pedagogy.  

ERIC Educational Resources Information Center

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…

Gholson, Sylvia A.

1998-01-01

231

Proximal Scaphoid Arthroplasty Using the Medial Femoral Trochlea Flap  

PubMed Central

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

Higgins, James P.; Burger, Heinze K.

2013-01-01

232

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

PubMed

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. PMID:10488395

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

1999-06-01

233

Renal proximal tubule function is preserved in Cftrtm2cam?F508 cystic fibrosis mice  

PubMed Central

Changes in proximal tubule function have been reported in cystic fibrosis patients. The aim of this study was to investigate proximal tubule function in the Cftrtm2cam?F508 cystic fibrosis (CF) mouse model. A range of techniques were used including renal clearance studies, in situ microperfusion, RT-PCR and whole-cell patch clamping. Renal Na+ clearance was similar in wild-type (1.4 ± 0.3 ?l min?1, number of animals, N= 12) and CF mice (1.6 ± 0.4 ?l min?1, N= 7) under control conditions. Acute extracellular volume expansion resulted in significant natriuresis in wild-type (7.0 ± 0.8 ?l min?1, N= 8) and CF mice (9.3 ± 1.4 ?l min?1, N= 9); no difference between genotypes was observed. In situ microperfusion revealed that fluid absorptive rate (Jv) was similar under control conditions between wild-type (2.2 ± 0.4 nl mm?1 min?1, n= 10) and CF mice (1.9 ± 0.3 nl mm?1 min?1, n= 11). Addition of a forskolin-dibutyryl cAMP (db-cAMP) cocktail to the perfusate caused no significant change in Jv in either wild-type (2.6 ± 0.7 nl mm?1 min?1, n= 10) or Cftrtm2cam?F508 mice (2.0 ± 0.5 nl mm?1 min?1, n= 10). CFTR expression was confirmed in samples of outer cortex using RT-PCR. However, no evidence for functional CFTR was obtained when outer cortical cells were stimulated with protein kinase A or forskolin-db-cAMP using whole-cell patch clamping. In conclusion, no functional deficit in proximal tubule function was found in Cftrtm2cam?F508 mice. This may be a consequence of a lack of whole-cell cAMP-dependent Cl? conductance in mouse proximal tubule cells. PMID:11306663

Kibble, J D; Balloch, K J D; Neal, A M; Hill, C; White, S; Robson, L; Green, R; Taylor, C J

2001-01-01

234

The action of angiotensin II on the intracellular sodium content of suspensions of rat proximal tubules.  

PubMed Central

1. Intracellular sodium levels in isolated suspensions of rat proximal tubles were measured by 23Na NMR spectroscopy and the effect of angiotensin II (AII) on these levels was recorded. 2. AII at 10(-11) M produced an increase in intracellular sodium content of approximately 20% (P < 0.001) from the steady-state level 5 min after the addition of the drug; intracellular sodium content then gradually returned to baseline levels over the subsequent 25 min. 3. Addition of AII at 10(-5) M resulted in a significant 20% decrease (P < 0.01) in the steady-state intracellular sodium level within 5 min. Again the effect was transient and steady-state intracellular sodium levels were re-established after 25 min. 4. Amiloride at 10(-4) M significantly attenuated the action of AII at 10(-11) M (P < 0.0001) and inhibited the transient response to AII at 10(-5) M (P < 0.01). When amiloride alone was added to the tubular suspension, intracellular sodium content decreased significantly by 18-22% (P < 0.001), and addition of both the high and low doses of AII did not have any further effect on intracellular sodium level. 5. The actions of both concentrations of AII were unaffected by an inhibitor of endopeptidase-24.11, phosphoramidon at 10(-6) M, which suggests that the transient action of AII was not due to the breakdown of AII by endopeptidase-24.11. 6. It is well known that AII at high doses inhibits and at low doses stimulates sodium transport across proximal tubular epithelial cells. From the present data it is proposed that AII has a transient biphasic action on intracellular sodium content which may reflect the stimulation of the Na(+)-H+ exchanger. PMID:8951724

Wong, P S; Johns, E J

1996-01-01

235

Proximate and landscape factors influence grassland bird distributions.  

PubMed

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 scales. Models with only landscape-scale tree cover were rarely competitive, indicating that broad-scale modeling alone, such as that based solely on remotely sensed data, is likely to be inadequate in explaining species distributions. PMID:16827003

Cunningham, Mary Ann; Johnson, Douglas H

2006-06-01

236

Space station proximity operations windows: Human factors design guidelines  

NASA Technical Reports Server (NTRS)

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.

Haines, Richard F.

1987-01-01

237

Optical rule checking for proximity-corrected mask shapes  

NASA Astrophysics Data System (ADS)

Optical Rule Checking (ORC) is an important vehicle to predict the failure of wafer shapes due to the process proximity effects. Optical Proximity Correction (OPC) if not aided by ORC may cause severe failures affecting the yield in manufacturing. However, it is fairly complicated to do ORC on mask shapes that are pre-corrected either by rules-based or by model-based OPC. ORC is also a good tool to capture the problems that may occur at multi-layer interactions. We present a methodology to use both geometric directives and limited optical simulation to detect potential failures using ORC. We extend our methodology to multi-layer interactions. In case of multi-layer ORC, we present several approaches that deal with how to judiciously mix the geometric directives and the optical simulations for different layers. We show the ORC can help us design better rules for OPC.

Mukherjee, Maharaj; Baum, Zachary; Nickel, John; Dunham, Timothy G.

2003-06-01

238

Automated space vehicle control for rendezvous proximity operations  

NASA Technical Reports Server (NTRS)

Rendezvous during the unmanned space exploration missions, such as a Mars Rover/Sample Return will require a completely automatic system from liftoff to docking. A conceptual design of an automated rendezvous, proximity operations, and docking system is being implemented and validated at the Johnson Space Center (JSC). The emphasis is on the progress of the development and testing of a prototype system for control of the rendezvous vehicle during proximity operations that is currently being developed at JSC. Fuzzy sets are used to model the human capability of common sense reasoning in decision-making tasks and such models are integrated with the expert systems and engineering control system technology to create a system that performs comparably to a manned system.

Lea, Robert N.

1988-01-01

239

Automated space vehicle control for rendezvous proximity operations  

NASA Technical Reports Server (NTRS)

Rendezvous during the unmanned space exploration missions, such as a Mars Rover/Sample Return will require a completely automatic system from liftoff to docking. A conceptual design of an automated rendezvous, proximity operations, and docking system is being implemented and validated at the Johnson Space Center (JSC). The emphasis is on the progress of the development and testing of a prototype system for control of the rendezvous vehicle during proximity operations that is currently being developed at JSC. Fuzzy sets are used to model the human capability of common sense reasoning in decision making tasks and such models are integrated with the expert systems and engineering control system technology to create a system that performs comparably to a manned system.

Lea, Robert N.

1988-01-01

240

Proximal hamstring avulsion in a professional soccer player.  

PubMed

Acute hamstring strains are a common athletic injury, which may be treated non-operatively with a satisfactory outcome. A complete proximal hamstring avulsion is a rare and potentially career ending injury to an elite athlete. For these high demand patients, surgical reattachment should be immediately undertaken to shorten return to sport and to improve functional outcome. This report describes the occurrence of a complete avulsion of the proximal hamstrings in a professional footballer during an international match. We highlight the clinical presentation, the appropriate diagnostic investigations, the surgical technique and the rehabilitation protocol for this injury. The successful surgical reattachment of the common hamstring tendon was confirmed by magnetic resonance imaging done 5 months after repair and allowed the player a full return to competition at 6 months after surgery. Hamstrings isokinetic peak torque was 80% at 6 months and 106% at 11 months after repair comparing with the uninjured side. PMID:22926296

Sonnery-Cottet, B; Archbold, P; Thaunat, M; Fayard, J-M; Canuto, S M G; Cucurulo, T

2012-12-01

241

Scintillation proximity radioimmunoassay utilizing 125I-labeled ligands  

SciTech Connect

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.

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

1985-12-01

242

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

PubMed Central

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

Maantay, Juliana A.; Brender, Jean D.

2011-01-01

243

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

SciTech Connect

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.

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

2010-01-29

244

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

245

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

246

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

247

Elements of proximal formative assessment in learners' discourse about energy  

NSDL National Science Digital Library

Proximal formative assessment, the just-in-time elicitation of students' ideas that informs ongoing instruction, is usually associated with the instructor in a formal classroom setting. However, the elicitation, assessment, and subsequent instruction that characterize proximal formative assessment are also seen in discourse among peers. We present a case in which secondary teachers in a professional development course at SPU are discussing energy flow in refrigerators. In this episode, a peer is invited to share her thinking (elicitation). Her idea that refrigerators move heat from a relatively cold compartment to a hotter environment is inappropriately judged as incorrect (assessment). The "instruction" (peer explanation) that follows is based on the second law of thermodynamics, and acts as corrective rather than collaborative.

Harrer, Benedikt W.; Scherr, Rachel E.; Wittmann, Michael C.; Close, Hunter G.; Frank, Brian W.

2012-05-15

248

Costs and Effectiveness of Treatment Alternatives for Proximal Caries Lesions  

PubMed Central

Objectives Invasive therapy of proximal caries lesions initiates a cascade of re-treatment cycles with increasing loss of dental hard tissue. Non- and micro-invasive treatment aim at delaying this cascade and may thus reduce both the health and economic burden of such lesions. This study compared the costs and effectiveness of alternative treatments of proximal caries lesions. Methods A Markov-process model was used to simulate the events following the treatment of a proximal posterior lesion (E2/D1) in a 20-year-old patient in Germany. We compared three interventions (non-invasive; micro-invasive using resin infiltration; invasive using composite restoration). We calculated the risk of complications of initial and possible follow-up treatments and modelled time-dependent non-linear transition probabilities. Costs were calculated based on item-fee catalogues in Germany. Monte-Carlo-microsimulations were performed to compare cost-effectiveness of non- versus micro-invasive treatment and to analyse lifetime costs of all three treatments. Results Micro-invasive treatment was both more costly and more effective than non-invasive therapy, with ceiling-value-thresholds for willingness-to-pay between 16.73 € for E2 and 1.57 € for D1 lesions. Invasive treatment was the most costly strategy. Calculated costs and effectiveness were sensitive to lesion stage, patient’s age, discounting rate and assumed initial treatment costs. Conclusions Non- and micro-invasive treatments have lower long-term costs than invasive therapy of proximal lesions. Micro-invasive therapy had the highest cost-effectiveness for treating D1 lesions in young patients. Decision makers with a willingness-to-pay over 16.73 € and 1.57 € for E2 and D1 lesions, respectively, will find micro-invasive treatment more cost-effective than non-invasive therapy. PMID:24475208

Schwendicke, Falk; Meyer-Lueckel, Hendrik; Stolpe, Michael; Dorfer, Christof Edmund; Paris, Sebastian

2014-01-01

249

Proximal and point detection of contaminated surfaces using Raman spectroscopy  

Microsoft Academic Search

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

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

2011-01-01

250

Cushing proximal symphalangism and the NOG and GDF5 genes  

Microsoft Academic Search

Proximal symphalangism (SYM1) is an autosomal-dominant developmental disorder of joint fusion. This disorder is best known\\u000a from famous historical descriptions of two large kindred: Cushing’s description in 1916 of the “straight-fingered” Brown family\\u000a of Virginia and Drinkwater’s description in 1917 of the British Talbot family of noble blood, descended from the English war\\u000a hero John Talbot, the first Earl of

Sara K. Plett; Walter E. Berdon; Robert A. Cowles; Rahmi Oklu; John B. Campbell

2008-01-01

251

Prevalence of rotator cuff tears in operative proximal humerus fractures.  

PubMed

Proximal humerus fractures and rotator cuff tears have been shown to have increasing rates with advancing age, theoretically leading to significant overlap in the 2 pathologies. The goal of this study was to examine the prevalence, associated factors, and effect on treatment of rotator cuff tears in surgically treated proximal humerus fractures. A retrospective review was performed of all patients who had surgery for a proximal humerus fracture from January 2007 to June 2012 in the shoulder department of a large academic institution. Patient demographics, the presence and management of rotator cuff tears, and surgical factors were recorded. Regression analysis was performed to determine which factors were associated with rotator cuff tears. This study reviewed 349 fractures in 345 patients. Of these, 30 (8.6%) had concomitant rotator cuff tears. Those with a rotator cuff tear were older (average age, 68.7 vs 63.1 years), were more likely to have had a dislocation (40% vs 12.5%), and were more likely to have undergone subsequent arthroscopic repair or reverse total shoulder arthroplasty than those without a rotator cuff tear. Most (22 of 30) were treated with suture repair at the time of surgery, but 5 patients underwent reverse total shoulder arthroplasty based primarily on the intraoperative finding of a significant rotator cuff tear. A concomitant rotator cuff tear in association with a proximal humerus fracture is relatively common. Rotator cuff tears are associated with older patients and those with a fracture-dislocation. In rare cases, these cases may require the availability of a reverse shoulder prosthesis. PMID:25361372

Choo, Andrew; Sobol, Garret; Maltenfort, Mitchell; Getz, Charles; Abboud, Joseph

2014-11-01

252

Proximal methods for nonlinear programming: double regularization and inexact subproblems  

Microsoft Academic Search

This paper describes the first phase of a project attempting to construct an efficient general-purpose nonlinear optimizer\\u000a using an augmented Lagrangian outer loop with a relative error criterion, and an inner loop employing a state-of-the art conjugate\\u000a gradient solver. The outer loop can also employ double regularized proximal kernels, a fairly recent theoretical development\\u000a that leads to fully smooth subproblems.

Jonathan Eckstein; Paulo J. S. Silva

2010-01-01

253

Evidence for water channels in renal proximal tubule cell membranes  

Microsoft Academic Search

Summary Water transport mechanisms in rabbit proximal convoluted cell membranes were examined by measurement of: (1) osmotic (Pf) and diffusional (Pd) water permeabilities, (2) inhibition ofPf by mercurials, and (3) activation energies (Ea) forPf.Pf was measured in PCT brush border (BBMV) and basolateral membrane (BLMV) vesicles, and in viable PCT cells by stopped-flow light scattering;Pd was measured in PCT cells

Mary M. Meyer; A. S. Verkman

1987-01-01

254

Inverse Proximity Effect in a Strongly Correlated Electron System  

Microsoft Academic Search

An anomalous superconducting proximity effect between a strongly correlated electron system and a normal metal is demonstrated. The model system is a 2D ultrathin superconducting quench-condensed Pb film. Such a highly disordered film has a reduced transition temperature (Tc = 1.7 K) due to the strong e--e- interaction. Instead of weakening the superconductivity, an overlayer of Ag on Pb induces

Olivier Bourgeois; Aviad Frydman; R. C. Dynes

2002-01-01

255

Evaluation of proximity devices, volume 2, phase 3  

NASA Astrophysics Data System (ADS)

Phase 1 of this three phase program consisted of test evaluations of commercially available proximity warning devices. Phase 2 resulted in the design and development of a microprocessor based distributed sensor ac electrometer that measures the electrostatic field at locations along a crane boom. In volume 1 of phase 2 the electrostatic fields around a crane boom were measured by the instrument at high voltage powerlines of various voltages and geometries. Volume 2 of phase 2 contains the appendixes.

Nixon, J. H.; Hipp, J. E.; Green, T. C.; Murch, G. H.; Cater, J. P.

1982-12-01

256

Acoustic emission study of lubricant effect on proximity contact recording  

Microsoft Academic Search

Pseudo-impact contact at the interface between proximity sliders and magnetic rigid disks were investigated by acoustic emission (AE) technique. Under a hot\\/wet condition of 60°C\\/80%RH and an operation speed of 19.15 m\\/s., AE responses were collected in real-time to monitor interaction events at the head\\/disk interface (HDI). The profile of AE responses shows various events at the HDI which can

Youmin Liu; C. L. Jiaa; A. Eltoukhy

1997-01-01

257

Diffraction effects in x-ray proximity printing  

Microsoft Academic Search

The influence of diffraction on the shape and size of features printed using x-ray proximity printing with a collimated x-ray source (measured beam divergence of approximately 0.2 mrad full width at half-maximum) at mask to wafer gaps of 25 [mu]m and above is described. Three major conclusions can be drawn from the results: (1) Diffraction can distort the shape of

A. D. Dubner; A. Wagner; J. Mauer; J. P. Levin

2009-01-01

258

Complex of myoglobin with phenol bound in a proximal cavity.  

PubMed

Sperm whale myoglobin (Mb) has weak dehaloperoxidase activity and catalyzes the peroxidative dehalogenation of 2,4,6-trichlorophenol (TCP) to 2,6-dichloroquinone. Crystals of Mb and of its more active G65T variant were used to study the binding of TCP, 4-iodophenol (4-IP) and phenol. The structures of crystals soaked overnight in a 10?mM solution of phenol revealed that a phenol molecule binds in the proximal cavity, forming a hydrogen bond to the hydroxyl of Tyr146 and hydrophobic contacts which include interactions with C? and C? of the proximal histidine His93. The phenol position corresponds to the strongest xenon binding site, Xe1. It appears that the ligand enters the proximal cavity through a gate formed by the flexible loops 79-86 and 93-103. TCP and 4-IP do not bind to Mb in this manner under similar conditions; however, it appears to be likely that dimethyl sulfoxide (DMSO), which was used at a concentration of 0.8?M to facilitate 4-IP dissolution, binds in the phenol/Xe1 binding site. In this structure, a water molecule coordinated to the heme iron was replaced by an oxygen molecule, reflecting the reduction of the heme. Crystals of Mb and G65T Mb soaked for 5-10?min did not show bound phenol. Kinetic studies of TCP dechlorination showed that phenol has a dual effect: it acts as a competitive inhibitor that is likely to interfere with TCP binding at the heme edge and as a weak activator, likely through binding in the proximal cavity. The lack of phenol bound at the heme edge in the crystal structures suggests that its inhibitory binding only takes place when the heme is activated by hydrogen peroxide. PMID:23192025

Huang, Xiao; Wang, Chunxue; Celeste, Lesa R; Lovelace, Leslie L; Sun, Shenfang; Dawson, John H; Lebioda, Lukasz

2012-12-01

259

Failure to demonstrate a hormonal inhibitor of proximal sodium reabsorption  

PubMed Central

Recently, it has been reported that a humoral inhibitor of proximal sodium reabsorption could be detected in plasma, and dialysates of plasma, of rats and dogs undergoing saline diuresis. We have repeated these studies using similar techniques and protocols. Fractional sodium reabsorption by the proximal tubule (as estimated in free-flow micropuncture studies from tubule fluid-to-plasma inulin ratios) was found not to be lower during infusion of “natriuretic” plasma than during subsequent infusion of “hydropenic” plasma. Similarly, infusion of natriuretic plasma failed to prolong reabsorptive half-time of the shrinking drop beyond that seen during hydropenic plasma infusion. No increase in urine volume or rate of sodium excretion was observed during the period of natriuretic plasma infusion, nor did natriuretic plasma result in an increase in these measures in rats undergoing water diuresis. It also has been reported that dialysates of natriuretic plasma, but not of hydropenic plasma, when placed directly into the tubule lumen, inhibit proximal sodium reabsorption. In double blind studies carried out independently in Bethesda, London, and Cologne, we failed to detect the presence of a dialyzable inhibitor in natriuretic plasma. Finally, in contrast to other recent reports, we were unable to detect inhibitory activity in plasma obtained from dogs during the “escape” phase of chronic deoxycorticosterone acetate administration. PMID:5771192

Wright, Fred S.; Brenner, Barry M.; Bennett, Cleaves M.; Keimowitz, Robert I.; Berliner, Robert W.; Schrier, Robert W.; Verroust, Pierre J.; De Wardener, Hugh E.; Holzgreve, Heinz

1969-01-01

260

Stability of proximal femoral grafts in canine hip arthroplasty.  

PubMed

In a canine model, the fixation stability of a prosthesis and proximal bone graft composite were measured relative to the distal femur. One group had the prosthesis graft composite cemented into the distal femur. The second group had the prosthesis graft composite press fit into the distal femur for biologic ingrowth. Displacements of the proximal femoral grafts relative to the host bone in each group were measured after ex vivo (acute with graft) implantation and 4 months after implantation. A third group with no osteotomy (acute intact) simulated perfect graft to host bone union. Relative displacements representing 6 degrees freedom (translation and rotation) were calculated from the displacement values measured by 9 eddy current transducers. Measurements of displacement were used to test the hypothesis that distal press fit fixation equals distal cement fixation at 4 months after implantation. In all cases the measured translations and rotations of the graft to implant construct were small and of a magnitude that should encourage bone ingrowth (< 0.05 mm and < 0.1 degree, respectively). The stability of the press fit group at 4 months was not significantly different from the cemented group in axial and transverse displacement during axial and transverse loading, respectively. There was no difference in stabilities at 4 months between distal press fit and cemented fixation in hip replacements requiring a proximal femoral graft. PMID:9269179

Heiner, J P; Kohles, S S; Manley, P A; Vanderby, R; Markel, M D

1997-08-01

261

Proximal femur segmentation in conventional pelvic x ray  

SciTech Connect

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.

Pilgram, Roland; Walch, Claudia; Kuhn, Volker; Schubert, Rainer; Staudinger, Roland [Institute of Applied Systems Research and Development, University for Health Sciences, Medical Informatics and Technology (UMIT), 6060 Hall in Tyrol (Austria) and Institute of Biomedical Image Analysis, University for Health Sciences, Medical Informatics and Technology (UMIT) (Austria); Department of Radiology, Medical University of Innsbruck (Austria); Department of Trauma Surgery and Sport Traumatology, Medical University of Innsbruck (Austria); Institute of Biomedical Image Analysis, University for Health Sciences, Medical Informatics and Technology (UMIT) (Austria); Institute of Applied Systems Research and Development, University for Health Sciences, Medical Informatics and Technology, 6060 Hall in Tyrol (Austria)

2008-06-15

262

Proximal Neuropathic Lesions in Distal Symmetric Diabetic Polyneuropathy  

PubMed Central

OBJECTIVE This study investigated high-resolution magnetic resonance neurography (MRN) in distal symmetric diabetic polyneuropathy (dPNP). RESEARCH DESIGN AND METHODS MRN comprised high-resolution transaxial imaging of peripheral nerves of the lower limbs in 20 patients with type 2 diabetes (10 with dPNP, type 2/dPNP[+], and 10 without dPNP, type 2/dPNP[?]), seven patients with type 1 diabetes (two with dPNP, type 1/dPNP[+], five without dPNP, type 1/dPNP[?]), and 10 nondiabetic control subjects. Intraneural T2 lesions, as the main diagnostic criterion of MRN, were detected visually by two independent observers and quantitatively by analysis of T2 contrast ratios. RESULTS Multifocal fascicular, symmetric intraneural T2 lesions occurred in the proximal trunks of sciatic nerves in four patients (three with type 2/dPNP[+] and one with type 1/dPNP[+]) but not in control subjects (type 2/dPNP[?], type 1/dPNP[?], nondiabetic control subjects), which was confirmed by quantitative analysis. Clinical severity was higher in patients with T2 lesions (neuropathy deficit score: 10 vs. 7.8; P = 0.05). CONCLUSIONS For the first time, proximal neuropathic lesions of dPNP are reported in vivo. This supports that accumulation of proximal, multifocal fascicular injury may be important in disease progression. PMID:21266652

Pham, Mirko; Oikonomou, Dimitrios; Baumer, Philipp; Bierhaus, Angelika; Heiland, Sabine; Humpert, Per M.; Nawroth, Peter P.; Bendszus, Martin

2011-01-01

263

Proximity corrected accurate in-die registration metrology  

NASA Astrophysics Data System (ADS)

193nm immersion lithography is the mainstream production technology for the 20nm and 14nm logic nodes. Multi-patterning of an increasing number of critical layers puts extreme pressure on wafer intra-field overlay, to which mask registration error is a major contributor [1]. The International Technology Roadmap for Semiconductors (ITRS [2]) requests a registration error below 4 nm for each mask of a multi-patterning set forming one layer on the wafer. For mask metrology at the 20nm and 14nm logic nodes, maintaining a precision-to-tolerance (P/T) ratio below 0.25 will be very challenging. Full characterization of mask registration errors in the active area of the die will become mandatory. It is well-known that differences in pattern density and asymmetries in the immediate neighborhood of a feature give rise to apparent shifts in position when measured by optical metrology systems, so-called optical proximity effects. These effects can easily be similar in magnitude to real mask placement errors, and uncorrected can result in mis-qualification of the mask. Metrology results from KLA-Tencor's next generation mask metrology system are reported, applying a model-based algorithm [3] which includes corrections for proximity errors. The proximity corrected, model-based measurements are compared to standard measurements and a methodology presented that verifies the correction performance of the new algorithm.

Daneshpanah, M.; Laske, F.; Wagner, M.; Roeth, K.-D.; Czerkas, S.; Yamaguchi, H.; Fujii, N.; Yoshikawa, S.; Kanno, K.; Takamizawa, H.

2014-07-01

264

Microalbuminuria and proximal tubule remodeling in the cardiometabolic syndrome.  

PubMed

Microalbuminuria is a simple screening test that is not only associated with an increased risk of progressive renal insufficiency, but also an increased risk of cardiovascular disease and stroke in the cardiometabolic syndrome. The role of oxidative stress, inflammation, and cellular-extracellular matrix remodeling fibrosis is very important, and the authors have previously observed that albuminuria is related, in part, to loss of the integrity of the glomerular filtration apparatus. The proximal tubule may play a more important role than previously thought, as it is estimated that in health this portion of the nephron reabsorbs 5-8 g of albumin that normally leaks through the glomerulus on a daily basis. Recently, the authors have made important preliminary observational findings regarding proximal tubule microvilli remodeling and oxidative stress, which may help to explain microalbuminuria. These observations suggest that albuminuria is associated with proximal tubule injury, as well as loss of integrity of the glomerular filtration barrier in association with obesity and insulin resistance. PMID:17679822

Hayden, Melvin R; Chowdhury, Nazif A; Witte, Lauren; Sowers, James R

2006-01-01

265

Lithographic process window optimization for mask aligner proximity lithography  

NASA Astrophysics Data System (ADS)

We introduce a complete methodology for process window optimization in proximity mask aligner lithography. The commercially available lithography simulation software LAB from GenISys GmbH was used for simulation of light propagation and 3D resist development. The methodology was tested for the practical example of lines and spaces, 5 micron half-pitch, printed in a 1 micron thick layer of AZ® 1512HS1 positive photoresist on a silicon wafer. A SUSS MicroTec MA8 mask aligner, equipped with MO Exposure Optics® was used in simulation and experiment. MO Exposure Optics® is the latest generation of illumination systems for mask aligners. MO Exposure Optics® provides telecentric illumination and excellent light uniformity over the full mask field. MO Exposure Optics® allows the lithography engineer to freely shape the angular spectrum of the illumination light (customized illumination), which is a mandatory requirement for process window optimization. Three different illumination settings have been tested for 0 to 100 micron proximity gap. The results obtained prove, that the introduced process window methodology is a major step forward to obtain more robust processes in mask aligner lithography. The most remarkable outcome of the presented study is that a smaller exposure gap does not automatically lead to better print results in proximity lithography - what the "good instinct" of a lithographer would expect. With more than 5'000 mask aligners installed in research and industry worldwide, the proposed process window methodology might have significant impact on yield improvement and cost saving in industry.

Voelkel, Reinhard; Vogler, Uwe; Bramati, Arianna; Erdmann, Andreas; Ünal, Nezih; Hofmann, Ulrich; Hennemeyer, Marc; Zoberbier, Ralph; Nguyen, David; Brugger, Juergen

2014-03-01

266

Proximal and distal Facial nerve exploration during superficial parotidectomy.  

PubMed

One of the most technique sensitive surgeries in the maxillofacial region is the parotid gland surgery owing to the close relation between the gland and the extra-cranial course of facial nerve. Facial nerve is generally located by means of a proximal surgical identification technique aimed at identifying the facial nerve at its point of exit from the stylomastoid foramen to its entry into the posteromedial surface of parotid gland. There are reports in the literature on distal nerve identification techniques, either as a choice or in cases where proximal nerve identification is difficult. The present report deals with personal clinical experience, describing both the techniques for detection of the facial nerve in 17 cases reported. The technique mainly chosen was conventional proximal nerve identification technique in 16 cases. Distal exploration of the buccal branch was undertaken only in one case, on account of difficulty in locating the main trunk intraoperatively, due to the presence of a post inflammatory fibrosis. The decision to resort to the identification of the buccal nerve is supported by the regular course and adequate size of this branch of facial nerve in its peripheral area co-located with stenson's duct, which enable it to be easily identified during surgery. PMID:22190775

Sharma, Rohit; Sirohi, D

2010-06-01

267

Hand proximity facilitates spatial discrimination of auditory tones.  

PubMed

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

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

2014-01-01

268

Shank2 redistributes with NaPilla during regulated endocytosis  

PubMed Central

Serum phosphate levels are acutely impacted by the abundance of sodium-phosphate cotransporter IIa (NaPiIIa) in the apical membrane of renal proximal tubule cells. PSD-95/Disks Large/Zonula Occludens (PDZ) domain-containing proteins bind NaPiIIa and likely contribute to the delivery, retention, recovery, and trafficking of NaPiIIa. Shank2 is a distinctive PDZ domain protein that binds NaPiIIa. Its role in regulating NaPiIIa activity, distribution, and abundance is unknown. In the present in vivo study, rats were maintained on a low-phosphate diet, and then plasma phosphate levels were acutely elevated by high-phosphate feeding to induce the recovery, endocytosis, and degradation of NaPiIIa. Western blot analysis of renal cortical tissue from rats given high-phosphate feed showed NaPiIIa and Shank2 underwent degradation. Quantitative immunofluorescence analyses, including microvillar versus intracellular intensity ratios and intensity correlation quotients, showed that Shank2 redistributed with NaPiIIa during the time course of NaPiIIa endocytosis. Furthermore, NaPiIIa and Shank2 trafficked through distinct endosomal compartments (clathrin, early endosomes, lysosomes) with the same temporal pattern. These in vivo findings indicate that Shank2 is positioned to coordinate the regulated endocytic retrieval and downregulation of NaPiIIa in rat renal proximal tubule cells. PMID:20810910

Dobrinskikh, Evgenia; Giral, Hector; Caldas, Yupanqui A.; Levi, Moshe

2010-01-01

269

Active ion transport in the renal proximal tubule. I. Transport and metabolic studies  

PubMed Central

Various aspects of the interrelationship between ion transport and cellular metabolism were investigated using a suspension of rabbit cortical tubules that were mainly proximal in nature. Using the intact tubules, the compartmentation of K within the renal cell was studied by performing 42K uptake studies. The oxygen consumption (QO2) of the tubules was measured under similar conditions, as well as when the Na pump was stimulated by increasing Na+ entry with nystatin. In addition, the state 3 rate of respiration was measured when the mitochondria of digitonin-permeabilized tubules were stimulated by ADP. At 37 and 25 degrees C, a single-compartmental uptake of 42K was observed, which suggests that extracellular K+ communicates with a single compartment within the renal cell. Between 37 and 15 degrees C, the ouabain- sensitive QO2 and the initial 42K uptake rate were parallel in an Arrhenius-type plot, which indicated that active ion transport and oxidative phosphorylation remain tightly coupled within this temperature range. At all temperatures between 37 and 15 degrees C, nystatin stimulated the QO2, which demonstrates that the entry of Na+ into the renal cells was rate limiting for active Na+ transport throughout this temperature range. Between 37 and 20 degrees C, the nystatin-stimulated QO2 was nearly equal to the state 3 rate of respiration, which suggests that active ion transport may be limited by ATP availability under these conditions. At 15 degrees C, nystatin addition stimulated the QO2 well below the state 3 respiratory rate. PMID:6502133

1984-01-01

270

Internal fixation of proximal humeral fractures with locking proximal humeral plate (LPHP) in elderly patients with osteoporosis  

PubMed Central

Background Different operative techniques used for treating displaced proximal humeral fractures could result in malunion, non-union, osteonecrosis of humeral head, loosening of screw and loss of reduction particularly in comminuted and osteoporotic fractures. Locking compression plate (LPHP) has been proposed for open reduction and internal fixation of these fractures and is associated with less complication rate. Materials and methods We prospectively assessed the functional outcome and the complications after an average follow-up of 24.9 months in 25 patients of proximal humeral fractures with osteoporosis. Mean age was 62 years. Using AO classification, 48% were type A and 52% type B. Results Mean constant score was 80 points. According to constant score, 28% had excellent outcome, 64% had good functional outcome, and 8% had moderate outcome. When the results were related to grades of osteoporosis, grade IV osteoporotic fractures had highest average Constant–Murley score (83 points, range 78–88 points), followed by grade III osteoporotic fractures (80 points, range 71–92 points), followed by grade II osteoporotic fractures (78 points, range 66–88 points). Varus malalignment and subacromial impingement were observed in 8% patients. Loosening of implant and loss of reduction were observed in 4% patients. Superficial infection was observed in 4% patients. Conclusions Locking compression plate (LPHP) is an advantageous implant in proximal humeral fractures due to angular stability, particularly in comminuted fractures and in osteoporotic bones in elderly patients, thus allowing early mobilization. PMID:19384611

Singh, Roop; Rohilla, Rajesh Kumar; Kadian, Virender Singh; Sangwan, Sukhbir Singh; Dhanda, Manjeet

2008-01-01

271

Induction of hypertrophy in cultured proximal tubule cells by extracellular NH4Cl.  

PubMed Central

Ammonia production increases in several models of renal hypertrophy in vivo. The present study was designed to determine whether ammonia can directly modulate the growth of renal cells in the absence of a change in extracellular acidity. In serum-free media NH4Cl (0-20 mM) caused JTC cells and a primary culture of rabbit proximal tubule cells to hypertrophy (increase in cell protein content) in a dose-dependent fashion without a change in DNA synthesis. Studies in JTC cells revealed that the cell protein content increased as a result of both an increase in protein synthesis and a decrease in protein degradation. Total cell RNA content and ribosome number increased after NH4Cl exposure and the cell content of the lysosomal enzymes cathepsin B and L decreased. Inhibition of the Na+/H+ antiporter with amiloride did not prevent the hypertrophic response induced by NH4Cl. The results indicate that ammonia is an important modulator of renal cell growth and that hypertrophy can occur in the absence of functioning Na+/H+ antiport activity. Images PMID:2480366

Golchini, K; Norman, J; Bohman, R; Kurtz, I

1989-01-01

272

Proximal Point Algorithm with Schur Decomposition on the Cone of Symmetric Semidenite  

Microsoft Academic Search

In this work, we propose a proximal algorithm for unconstrained optimization on the cone of symmetric semidenite positive matrices. It appears to be the rst in the proximal class on the set of methods that convert a Symmetric Denite Positive Optimization in Nonlinear Optimization. It replaces the main iteration of the conceptual proximal point algorithm by a sequence of nonlinear

Ronaldo Greg; Paulo Roberto Oliveiraz

273

Deriving the number of jobs in proximity services from the number of inhabitants in French rural  

E-print Network

Deriving the number of jobs in proximity services from the number of inhabitants in French rural a minimum requirement approach to derive the number of jobs of proximity services per inhabitant observe that the minimum number of service jobs per inhabitant (interpreted as jobs of proximity services

Paris-Sud XI, Université de

274

Eddy-current Type Proximity Sensor with Closed Magnetic Circuit Geometry  

Microsoft Academic Search

Eddy-current type proximity sensor is a non-contact type sensing device to detect the approach of a conductor. This paper investigates electromagnetic properties of the proximity sensor with magnetic flux shield which has closed magnetic circuit geometry by FEM analysis and experiments. Although it has closed magnetic flux path, its sensing property is enhanced compared with the conventional proximity sensor

K. Koibuchi; K. Sawa; T. Honma; T. Hayashi; K. Ueda; H. Sasaki

2006-01-01

275

Exp Nephrol 1999;7:1519 The Proximal Tubule Phenotype and Its  

E-print Network

on the proximal tubule and its role in the pathology of ischemic acute renal failure and poly- cystic kidneyMinireview Exp Nephrol 1999;7:15­19 logy The Proximal Tubule Phenotype and Its Disruption in Acute of knockout mice with an inactivation of the HNF1 gene. After ischemic renal damage the proximal tubule re

Witzgall, Ralph - Naturwissenschaftliche Fakultät III

276

Evaluation of Proximal Contacts of Posterior Composite Restorations with 4 Placement Techniques  

Microsoft Academic Search

Background: Contrary to the situation for amalgam restorations, obtaining acceptable proximal contacts with posterior composite restorations can be difficult. Proximal contacts that are less than ideal may permit food impaction and subsequent caries formation and periodontal problems. Purpose: The aim of this study was to assess the quality of proximal contacts of posterior composite restorations placed with 4 restorative techniques.

Wafa A. El-Badrawy; Brian W. Leung; Omar El-Mowafy; Jose H. Rubo; Marcia H. Rubo

277

Keyword Proximity Search in XML Trees Vagelis Hristidis, Nick Koudas, Member, IEEE, Yannis Papakonstantinou, and  

E-print Network

Keyword Proximity Search in XML Trees Vagelis Hristidis, Nick Koudas, Member, IEEE, Yannis proximity search in querying XML documents in addition to text documents. For example, given query keywords--Lowest common ancestor, tree proximity search, XML keyword search. æ 1 INTRODUCTION KEYWORD search is a user

Hristidis, Vagelis

278

Properties of an Inwardly Rectifying ATP-sensitive K+ Channel in the Basolateral Membrane of Renal Proximal Tubule  

PubMed Central

The potassium conductance of the basolateral membrane (BLM) of proximal tubule cells is a critical regulator of transport since it is the major determinant of the negative cell membrane potential and is necessary for pump-leak coupling to the Na+,K+-ATPase pump. Despite this pivotal physiological role, the properties of this conductance have been incompletely characterized, in part due to difficulty gaining access to the BLM. We have investigated the properties of this BLM K+ conductance in dissociated, polarized Ambystoma proximal tubule cells. Nearly all seals made on Ambystoma cells contained inward rectifier K+ channels (?slope, in = 24.5 ± 0.6 pS, ?chord, out = 3.7 ± 0.4 pS). The rectification is mediated in part by internal Mg2+. The open probability of the channel increases modestly with hyperpolarization. The inward conducting properties are described by a saturating binding–unbinding model. The channel conducts Tl+ and K+, but there is no significant conductance for Na+, Rb+, Cs+, Li+, NH4+, or Cl?. The channel is inhibited by barium and the sulfonylurea agent glibenclamide, but not by tetraethylammonium. Channel rundown typically occurs in the absence of ATP, but cytosolic addition of 0.2 mM ATP (or any hydrolyzable nucleoside triphosphate) sustains channel activity indefinitely. Phosphorylation processes alone fail to sustain channel activity. Higher doses of ATP (or other nucleoside triphosphates) reversibly inhibit the channel. The K+ channel opener diazoxide opens the channel in the presence of 0.2 mM ATP, but does not alleviate the inhibition of millimolar doses of ATP. We conclude that this K+ channel is the major ATP-sensitive basolateral K+ conductance in the proximal tubule. PMID:9417141

Mauerer, Ulrich R.; Boulpaep, Emile L.; Segal, Alan S.

1998-01-01

279

Functional results after proximal row carpectomy to salvage a wrist.  

PubMed

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. PMID:18991174

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

2008-01-01

280

Proximate composition and caloric content of eight Lake Michigan fishes  

USGS Publications Warehouse

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.

Rottiers, Donald V.; Tucker, Robert M.

1982-01-01

281

Residential Proximity to Freeways and Autism in the CHARGE Study  

PubMed Central

Background Little is known about environmental causes and contributing factors for autism. Basic science and epidemiologic research suggest that oxidative stress and inflammation may play a role in disease development. Traffic-related air pollution, a common exposure with established effects on these pathways, contains substances found to have adverse prenatal effects. Objectives We examined the association between autism and proximity of residence to freeways and major roadways during pregnancy and near the time of delivery, as a surrogate for air pollution exposure. Methods Data were from 304 autism cases and 259 typically developing controls enrolled in the Childhood Autism Risks from Genetics and the Environment (CHARGE) study. The mother’s address recorded on the birth certificate and trimester-specific addresses derived from a residential history obtained by questionnaire were geocoded, and measures of distance to freeways and major roads were calculated using ArcGIS software. Logistic regression models compared residential proximity to freeways and major roads for autism cases and typically developing controls. Results Adjusting for sociodemographic factors and maternal smoking, maternal residence at the time of delivery was more likely be near a freeway (? 309 m) for cases than for controls [odds ratio (OR) = 1.86; 95% confidence interval (CI), 1.04–3.45]. Autism was also associated with residential proximity to a freeway during the third trimester (OR = 2.22; CI, 1.16–4.42). After adjustment for socioeconomic and sociodemographic characteristics, these associations were unchanged. Living near other major roads at birth was not associated with autism. Conclusions Living near a freeway was associated with autism. Examination of associations with measured air pollutants is needed. PMID:21156395

Volk, Heather E.; Hertz-Picciotto, Irva; Delwiche, Lora; Lurmann, Fred; McConnell, Rob

2011-01-01

282

Percutaneous Stabilization of Impending Pathological Fracture of the Proximal Femur  

SciTech Connect

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.

Deschamps, Frederic, E-mail: frederic.deschamps@igr.fr; Farouil, Geoffroy, E-mail: g.farouil@gmail.com; Hakime, Antoine, E-mail: thakime@yahoo.com; Teriitehau, Christophe, E-mail: cteriitehau@me.com; Barah, Ali, E-mail: ali.barah@gmail.com; Baere, Thierry de, E-mail: debaere@igr.fr [Institut Gustave Roussy, Interventional Radiology Department (France)

2012-12-15

283

The proximate causes of sexual size dimorphism in Phrynocephalus przewalskii.  

PubMed

Sexual size dimorphism (SSD) is a common phenomenon and is a central topic in evolutionary biology. Recently, the importance of pursuing an ontogenetic perspective of SSD has been emphasized, to elucidate the proximate physiological mechanisms leading to its evolution. However, such research has seldom focused on the critical periods when males and females diverge. Using mark-recapture data, we investigated the development of SSD, sex-specific survivorship, and growth rates in Phrynocephalus przewalskii (Agamidae). We demonstrated that both male and female lizards are reproductively mature at age 10-11 months (including 5 months hibernation). Male-biased SSD in snout-vent length (SVL) was only found in adults and was fully expressed at age 11 months (June of the first full season of activity), just after sexual maturation. However, male-biased SSD in tail length (TL), hind-limb length (LL), and head width (HW) were fully expressed at age 9-10 months, just before sexual maturation. Analysis of age-specific linear growth rates identified sexually dimorphic growth during the fifth growth month (age 10-11 months) as the proximate cause of SSD in SVL. The males experienced higher mortality than females in the first 2 years and only survived better than females after SSD was well developed. This suggests that the critical period of divergence in the sizes of male and female P. przewalskii occurs between 10 and 11 months of age (May to June during the first full season of activity), and that the sexual difference in growth during this period is the proximate cause. However, the sexual difference in survivorship cannot explain the male-biased SSD in SVL. Our results indicate that performance-related characteristics, such as TL, HW, and LL diverged earlier than SVL. The physiological mechanisms underlying the different growth patterns of males and females may reflect different energy allocations associated with their different reproductive statuses. PMID:24465815

Zhao, Wei; Liu, Nai-Fa

2014-01-01

284

Uncemented allograft-prosthetic composite reconstruction of the proximal femur  

PubMed Central

Background: Allograft–prosthetic composite can be divided into three groups names cemented, uncemented, and partially cemented. Previous studies have mainly reported outcomes in cemented and partially cemented allograft–prosthetic composites, but have rarely focused on the uncemented allograft–prosthetic composites. The objectives of our study were to describe a surgical technique for using proximal femoral uncemented allograft–prosthetic composite and to present the radiographic and clinical results. Materials and Methods: Twelve patients who underwent uncemented allograft–prosthetic composite reconstruction of the proximal femur after bone tumor resection were retrospectively evaluated at an average followup of 24.0 months. Clinical records and radiographs were evaluated. Results: In our series, union occurred in all the patients (100%; range 5-9 months). Until the most recent followup, there were no cases with infection, nonunion of the greater trochanter, junctional bone resorption, dislocation, allergic reaction, wear of acetabulum socket, recurrence, and metastasis. But there were three periprosthetic fractures which were fixed using cerclage wire during surgery. Five cases had bone resorption in and around the greater trochanter. The average Musculoskeletal Tumor Society (MSTS) score and Harris hip score (HHS) were 26.2 points (range 24-29 points) and 80.6 points (range 66.2-92.7 points), respectively. Conclusions: These results showed that uncemented allograft–prosthetic composite could promote bone union through compression at the host–allograft junction and is a good choice for proximal femoral resection. Although this technology has its own merits, long term outcomes are yet not validated. PMID:24932036

Min, Li; Peng, Jing; Duan, Hong; Zhang, Wenli; Zhou, Yong; Tu, Chongqi

2014-01-01

285

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

PubMed

This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on educating and empowering women in these enclaves. Women are in charge of birth spacing and all aspects of management of energy, food, water and the local environment, more so than men, in most countries. PMID:12284190

Shaw, R P

1989-01-01

286

Scheduling in heterogeneous computing environments for proximity queries.  

PubMed

We present a novel, linear programming (LP)-based scheduling algorithm that exploits heterogeneous multicore architectures such as CPUs and GPUs to accelerate a wide variety of proximity queries. To represent complicated performance relationships between heterogeneous architectures and different computations of proximity queries, we propose a simple, yet accurate model that measures the expected running time of these computations. Based on this model, we formulate an optimization problem that minimizes the largest time spent on computing resources, and propose a novel, iterative LP-based scheduling algorithm. Since our method is general, we are able to apply our method into various proximity queries used in five different applications that have different characteristics. Our method achieves an order of magnitude performance improvement by using four different GPUs and two hexa-core CPUs over using a hexa-core CPU only. Unlike prior scheduling methods, our method continually improves the performance, as we add more computing resources. Also, our method achieves much higher performance improvement compared with prior methods as heterogeneity of computing resources is increased. Moreover, for one of tested applications, our method achieves even higher performance than a prior parallel method optimized manually for the application. We also show that our method provides results that are close (e.g., 75 percent) to the performance provided by a conservative upper bound of the ideal throughput. These results demonstrate the efficiency and robustness of our algorithm that have not been achieved by prior methods. In addition, we integrate one of our contributions with a work stealing method. Our version of the work stealing method achieves 18 percent performance improvement on average over the original work stealing method. This result shows wide applicability of our approach. PMID:23846096

Kim, Duksu; Lee, Jinkyu; Lee, Junghwan; Shin, Insik; Kim, John; Yoon, Sung-Eui

2013-09-01

287

Patellofemoral osteoarthritis after Insall's proximal realignment for recurrent patellar dislocation.  

PubMed

PURPOSE: The aim of the present study was to retrospectively investigate the development of patellofemoral osteoarthritis after the historical Insall's proximal realignment for patellar stabilisation in patients with recurrent patellar dislocation. Furthermore, risk factors for recurrent patellar dislocation and for patellofemoral osteoarthritis development were evaluated. METHODS: Forty-two patients underwent patellofemoral stabilising surgery by the historic Insall's proximal realignment; they were evaluated with a mean follow-up period of 52 months. Plain radiography was used to document osteoarthritic changes by using the Iwano classification. MRIs obtained at the latest follow-up were evaluated for patellofemoral cartilage lesions. Univariate and multivariate logistic regression analyses were performed to evaluate the influence of trochlear dysplasia, tibial tubercle-trochlear groove distance and patellar height on redislocation. Pearson's ? (2) and the Spearman's correlation tests were used to assess a possible correlation between trochlear dysplasia and patellar dislocation, as well as between instability and development of patellofemoral osteoarthritis. RESULTS: At the latest follow-up, plain radiographs showed a significant increase in patellofemoral osteoarthritis (grades II-IV according to the Iwano classification) in 18 patients (43 %) compared with 4 patients (10 %) at the time of surgery (P = 0.001). Patellofemoral cartilage lesions (grades II-IV) were detected in 18 patients (43 %) on MRI. Nine patients (21 %) had at least one incidence of redislocation at follow-up. Estimated redislocation-associated risk factors could not be determined. Trochlear dysplasia had a significant impact on patellofemoral osteoarthritis development (P = 0.001), whereas recurrent patellar instability had none (n.s.). CONCLUSION: Insall's proximal realignment technique leads to a significant progression of patellofemoral osteoarthritis. No risk factors for redislocation could be found; however, the presence of trochlear dysplasia did correlate with patellofemoral osteoarthritis. LEVEL OF EVIDENCE: IV. PMID:23545586

Schüttler, Karl F; Struewer, Johannes; Roessler, Philip P; Gesslein, Markus; Rominger, Marga B; Ziring, Ewgeni; Efe, Turgay

2013-04-01

288

Outcome of closed proximal phalangeal fractures of the hand  

PubMed Central

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, but with added risk of digital stiffness. Percutaneous pinning is a reliable, most commonly used surgical modality and technically easier. Both conservative and surgical modalities have good efficacy when used judiciously PMID:21886925

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

2011-01-01

289

Transport ofl-cystine in isolated perfused proximal straight tubules  

Microsoft Academic Search

Unidirectional fluxes ofl-35S-cystine and intracellular35S activity were measured in isolated perfused segments of rabbit proximal straight tubule. The absorptive (lumen-to-both) flux ofl-35S-cysteine showed a tendency toward saturation within the concentration limits imposed by the low solubility of cystine (0.3 mmol·l-1). In contrast, for the bath-to-lumen fluxes, there was a linear relation between the bathing solution concentration ofl-35S-cystine and the rate

James A. Schafer; Mary L. Watkins

1984-01-01

290

Cascading failures in networks with proximate dependent nodes  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

291

Ewing sarcoma of the proximal phalanx: case report.  

PubMed

Abstract We report a case of primary Ewing sarcoma of the proximal phalanx of the right middle finger in an 18-year-old boy. He was treated with neoadjuvant chemotherapy, followed by ray amputation. To restore maximum function, the index ray was transferred to the base of the third metacarpal bone and fixed with a plate. The function of his right hand after the operation was excellent and the cosmetic appearance acceptable. There was no evidence of local recurrence or metastasis after 20 months follow up. PMID:23822186

Fujii, Hiromasa; Honoki, Kanya; Kobata, Yasunori; Yajima, Hiroshi; Kido, Akira; Takakura, Yoshinori

2014-12-01

292

Ground plane insulating coating for proximity focused devices  

DOEpatents

A thin layer of alumina (aluminum oxide) is coated onto the ground plane of a microchannel plate (MCP) without covering the pores of the MCP so it does not effect the performance. The coating is sputtered onto the ground plane at a very steep angle. The addition of the thin dielectric coating of alumina greatly improves the spatial resolution of proximity focused image intensifiers using a narrow gap between the phosphor screen and the MCP. With the coating on the ground plane and the same gap the phosphor screen can be ran at 9000 volts, as compared to 3 kV without the coating. 3 figs.

Power, G.D.

1998-07-14

293

Osteochondroma Arising from the Proximal Fibula: A Rare Presentation  

PubMed Central

Osteochondromas are commonly encountered benign tumours and they are characterized by cartilage capped bony growths that project from the surface of the affected bone. Osteochondromas tend to grow eccentrically rather than centrifugally. We are reporting a case of an 18-year-old male, who had presentation of a large, hard, irregular swelling over anterolateral aspect of his right leg. There was no neurovascular deficit in the extremity. Computed tomography showed that the origin of the tumour was probably proximal fibula. En-block excision of mass was done. A histopathological examination confirmed the diagnosis of a benign osteochondroma. Patient had uneventful recovery without any evidence of recurrence. PMID:24959469

Malgonde, Monika; Jain, Pramod

2014-01-01

294

Osteochondroma arising from the proximal fibula: a rare presentation.  

PubMed

Osteochondromas are commonly encountered benign tumours and they are characterized by cartilage capped bony growths that project from the surface of the affected bone. Osteochondromas tend to grow eccentrically rather than centrifugally. We are reporting a case of an 18-year-old male, who had presentation of a large, hard, irregular swelling over anterolateral aspect of his right leg. There was no neurovascular deficit in the extremity. Computed tomography showed that the origin of the tumour was probably proximal fibula. En-block excision of mass was done. A histopathological examination confirmed the diagnosis of a benign osteochondroma. Patient had uneventful recovery without any evidence of recurrence. PMID:24959469

Kumar, Manoj; Malgonde, Monika; Jain, Pramod

2014-04-01

295

DIABETIC NEUROPATHY PART 2: PROXIMAL AND ASSYMMETRIC PHENOTYPES  

PubMed Central

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

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

2014-01-01

296

A General Simulation Method for Multiple Bodies in Proximate Flight  

NASA Technical Reports Server (NTRS)

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.

Meakin, Robert L.

2003-01-01

297

Proximal interphalangeal joint replacement: resurfacing pyrocarbon versus silicone arthroplasty.  

PubMed

Prosthetic replacement of the proximal interphalangeal joints is an operative treatment for osteoarhtritis, to preserve the range of motion and the function of the hand. The purpose of this study is to detect the differences regarding pain and function between a silicone implant using a volar approach and a resurfacing implant, placed through a dorsal approach. Patients were reviewed clinically and scored. We found no significant differences in outcome between the two types of implants. However, the complication rate in the resurfacing group was significantly higher. Also, the economic cost of both implants was significantly different. The resurfacing implants were more expensive than the silicone implants. PMID:25090791

Van Nuffel, Maarten; Degreef, Ilse; Willems, Sofie; De Smet, Luc

2014-06-01

298

Pathology Case Study: Pain in Left Proximal Medial Thigh  

NSDL National Science Digital Library

This is a skeletal and soft tissue pathology case study presented by the University of Pittsburgh Department of Pathology in which a 9-year-old girl has left proximal medial thigh pain. Visitors are given both the microscopic and gross descriptions, including images, and are given the opportunity to diagnose the patient. This is an excellent resource for students in the health sciences to familiarize themselves with using patient history and laboratory results to diagnose. It is also a helpful site for educators to use to introduce or test student learning in skeletal and soft tissue pathology.

Cohen, Lance; Dickman, Paul S.; Parizhskaya, Maria

2007-10-10

299

Dendritic Na Current Inactivation Can Increase Cell Excitability By Delaying a Somatic Depolarizing Afterpotential  

E-print Network

over at least the proximal 200 m of the apical dendritic tree. A progressive increase in dendriticDendritic Na Current Inactivation Can Increase Cell Excitability By Delaying a Somatic Depolarizing, Fernando R., W. Hamish Mehaffey, and Ray W. Turner. Dendritic Na current inactivation can increase cell

Turner, Ray

300

Vision-based Proximity Detection in Retinal Surgery  

PubMed Central

In retinal surgery, surgeons face difficulties such as indirect visualization of surgical targets, physiological tremor and lack of tactile feedback, which increase the risk of retinal damage caused by incorrect surgical gestures. In this context, intra-ocular proximity sensing has the potential to overcome current technical limitations and increase surgical safety. In this paper we present a system for detecting unintentional collisions between surgical tools and the retina using the visual feedback provided by the opthalmic stereo microscope. Using stereo images, proximity between surgical tools and the retinal surface can be detected when their relative stereo disparity is small. For this purpose, we developed a system comprised of two modules. The first is a module for tracking the surgical tool position on both stereo images. The second is a disparity tracking module for estimating a stereo disparity map of the retinal surface. Both modules were specially tailored for coping with the challenging visualization conditions in retinal surgery. The potential clinical value of the proposed method is demonstrated by extensive testing using a silicon phantom eye and recorded rabbit in vivo data. PMID:22692869

Richa, Rogerio; Balicki, Marcin; Sznitman, Raphael; Meisner, Eric; Taylor, Russell; Hager, Gregory

2012-01-01

301

Pulse compression grating fabrication by diffractive proximity photolithography.  

PubMed

We report about a newly devised throughput-scalable fabrication method for high-quality periodic submicron structures. The process is demonstrated for optical transmission gratings in fused silica with a period of 800 nm (1250??lines/mm) to be used in laser pulse compression. The technology is based on an innovative advancement of i-line proximity photolithography performed in a mask aligner. The aerial image is encoded in a rigorously optimized electron-beam-written three-level phase mask which is illuminated by an adapted multipole configuration of incidence angles. In comparison to conventional proximity lithography, the process enables a significantly higher resolution while maintaining a good depth of focus--in contrast to lithography based on direct Talbot-imaging. Details about the grating fabrication process and characterization of fabricated pulse compression grating wafers are presented. The gratings show a diffraction efficiency of 97% at a wavelength of 1030 nm and a wavefront error comparable to gratings fabricated by electron-beam lithography. PMID:24562273

Stuerzebecher, Lorenz; Fuchs, Frank; Harzendorf, Torsten; Zeitner, Uwe D

2014-02-15

302

Proximity effect in superconductor/conical magnet/ferromagnet heterostructures  

NASA Astrophysics Data System (ADS)

At the interface between a superconductor and a ferromagnetic metal spin-singlet Cooper pairs can penetrate into the ferromagnetic part of the heterostructure with an oscillating and decaying spin-singlet Cooper pair density. However, if the interface allows for a spin-mixing effect, equal-spin spin-triplet Cooper pairs can be generated that can penetrate much further into the ferromagnetic part of the heterostructure, known as the long-range proximity effect. Here, we present results of spin-mixing based on self-consistent solutions of the microscopic Bogoliubov-de Gennes equations in the clean limit incorporating a tight-binding model. In particular, we include a conical magnet into our model heterostructure to generate the spin-triplet Cooper pairs and analyse the influence of conical and ferromagnetic layer thickness on the unequal-spin and equal-spin spin-triplet pairing correlations. It will be shown that, in agreement with experimental observations, a minimum thickness of the conical magnet is necessary to generate a sufficient amount of equal-spin spin-triplet Cooper pairs allowing for the long-range proximity effect.

Fritsch, Daniel; Annett, James F.

2014-05-01

303

Probing nuclear pore complex architecture with proximity-dependent biotinylation.  

PubMed

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. PMID:24927568

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

2014-06-17

304

Proximity to Pollution Sources and Risk of Amphibian Limb Malformation  

PubMed Central

The cause of limb deformities in wild amphibian populations remains unclear, even though the apparent increase in prevalence of this condition may have implications for human health. Few studies have simultaneously assessed the effect of multiple exposures on the risk of limb deformities. In a cross-sectional survey of 5,264 hylid and ranid metamorphs in 42 Vermont wetlands, we assessed independent risk factors for nontraumatic limb malformation. The rate of nontraumatic limb malformation varied by location from 0 to 10.2%. Analysis of a subsample did not demonstrate any evidence of infection with the parasite Ribeiroia. We used geographic information system (GIS) land-use/land-cover data to validate field observations of land use in the proximity of study wetlands. In a multiple logistic regression model that included land use as well as developmental stage, genus, and water-quality measures, proximity to agricultural land use was associated with an increased risk of limb malformation (odds ratio = 2.26; 95% confidence interval, 1.42–3.58; p < 0.001). The overall discriminant power of the statistical model was high (C = 0.79). These findings from one of the largest systematic surveys to date provide support for the role of chemical toxicants in the development of amphibian limb malformation and demonstrate the value of an epidemiologic approach to this problem. PMID:16263502

Taylor, Brynn; Skelly, David; Demarchis, Livia K.; Slade, Martin D.; Galusha, Deron; Rabinowitz, Peter M.

2005-01-01

305

Group Problem Solving as a Zone of Proximal Development activity  

NASA Astrophysics Data System (ADS)

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).

Brewe, Eric

2006-12-01

306

The effect of proximity on landmark use in Clark's nutcrackers.  

PubMed

Clark's nutcrackers, Nucifraga columbiana, store thousands of pine seeds during the autumn and retrieve them throughout the winter. It has been shown that these birds are able to use visual cues to relocate hidden food in the laboratory. In this set of experiments, we trained three groups of Clark's nutcrackers to find a hidden food goal that was placed in the same spatial location relative to the testing room. During training, the location of two local cues in relation to the goal differed between the three groups. Group 1 learned the task with the cues closest to the goal, group 2 with the cues further from the goal, and group 3 with the cues furthest from the goal. To test whether the proximity of these two local cues to the goal affected how spatial information was used, we manipulated local and global information in a series of experiments. Results indicated that local cues were more important sources of spatial information for group 1, whereas global cues seemed to be used more by birds in groups 2 and 3. These findings suggest that the proximity of visual cues lead to overshadowing of other sources of spatial information surrounding the goal. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10479363

Gould-Beierle; Kamil

1999-09-01

307

Method to measure tone of axial and proximal muscle.  

PubMed

The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention. PMID:22214974

Gurfinkel, Victor S; Cacciatore, Timothy W; Cordo, Paul J; Horak, Fay B

2011-01-01

308

Renal defects in KCNE1 knockout mice are mimicked by chromanol 293B in vivo: identification of a KCNE1-regulated K+ conductance in the proximal tubule  

PubMed Central

Abstract KCNE1 is a protein of low molecular mass that is known to regulate the chromanol 293B and clofilium-sensitive K+ channel, KCNQ1, in a number of tissues. Previous work on the kidney of KCNE1 and KCNQ1 knockout mice has revealed that these animals have different renal phenotypes, suggesting that KCNE1 may not regulate KCNQ1 in the renal system. In the current study, in vivo clearance approaches and whole cell voltage-clamp recordings from isolated renal proximal tubules were used to examine the physiological role of KCNE1. Data from wild-type mice were compared to those from KCNE1 knockout mice. In clearance studies the KCNE1 knockout mice had an increased fractional excretion of Na+, Cl?, HCO3? and water. This profile was mimicked in wild-type mice by infusion of chromanol 293B, while chromanol was without effect in KCNE1 knockout animals. Clofilium also increased the fractional excretion of Na+, Cl? and water, but this was observed in both wild-type and knockout mice, suggesting that KCNE1 was regulating a chromanol-sensitive but clofilium-insensitive pathway. In whole cell voltage clamp recordings from proximal tubules, a chromanol-sensitive, K+-selective conductance was identified that was absent in tubules from knockout animals. The properties of this conductance were not consistent with its being mediated by KCNQ1, suggesting that KCNE1 regulates another K+ channel in the renal proximal tubule. Taken together these data suggest that KCNE1 regulates a K+-selective conductance in the renal proximal tubule that plays a relatively minor role in driving the transport of Na+, Cl? and HCO3?. PMID:21576273

Neal, A M; Taylor, H C; Millar, I D; Kibble, J D; White, S J; Robson, L

2011-01-01

309

Spectrum and subcellular determinants of fluorinated anesthetic-mediated proximal tubular injury.  

PubMed Central

Currently used fluorinated anesthetics are chemically related to methoxyflurane (MF), a drug that caused many cases of clinical acute renal failure during previous widespread use. To determine whether newer fluorinated anesthetics might also have nephrotoxic effects, three currently used agents (isoflurane (IF), sevoflurane (SF), and desflurane) or MF were added to rat proximal tubular segments, followed by assessments of cell integrity (ATP levels and percent lactic dehydrogenase release). Ether served as a negative control. MF, IF, and SF each induced lethal proximal tubular segment injury (up to 92, 71, and 30% lactic dehydrogenase release, respectively) and massive ATP depletion. ATP losses were observed at or near clinically relevant drug levels, they preceded lethal injury, and they correlated with approximately 50% and approximately 100% reductions in total and Na,K-ATPase-driven respiration, respectively. Clinically relevant inorganic fluoride levels simulated fluorinated anesthetic toxicity. However, fluoride release from the anesthetics (a cytochrome P450 process) did not appear to be required for toxicity (no protection with P450 inhibitors and no detectable inorganic fluoride release). As IF was judged to be one-third as toxic as MF, subclinical tubular injury (increased urine N-acetyl-beta-D-glucosaminidase (NAG) levels) after its use was sought in 19 surgical patients. Fifteen patients undergoing comparable operations with SF (approximately one-half as toxic as IF in vitro) and nine patients undergoing regional/ local anesthesia were controls. The IF group doubled its urinary NAG levels by the end of surgery (P < 0.005). Conversely, NAG levels remained stable in both control groups. The conclusions are that 1) currently used fluorinated anesthetics, particularly IF, share (but to a lesser degree) MFs tubulotoxic effects, 2) ATP depletion (probably due to decreased production) and Na,K-ATPase inhibition are likely contributing mechanisms, 3) fluoride is a prime determinant of this toxicity, and 4) tubular injury can be expressed at or near clinically relevant anesthetic/inorganic fluoride levels. That increased enzymuria can develop in patients after IF anesthesia suggests that the above in vitro data could have potential clinical relevance in selected patients. PMID:9176410

Lochhead, K. M.; Kharasch, E. D.; Zager, R. A.

1997-01-01

310

Proximal microdeletions and microduplications of 1q21.1 contribute to variable abnormal phenotypes  

PubMed Central

Chromosomal band 1q21.1 can be divided into two distinct regions, proximal and distal, based on segmental duplications that mediate recurrent rearrangements. Microdeletions and microduplications of the distal region within 1q21.1, which are susceptibility factors for a variety of neurodevelopmental phenotypes, have been more extensively studied than proximal microdeletions and microduplications. Proximal microdeletions are known as a susceptibility factor for thrombocytopenia-absent radius (TAR) syndrome, but it is unclear if these proximal microdeletions have other phenotypic consequences. Therefore, to elucidate the clinical significance of rearrangements of the proximal 1q21.1 region, we evaluated the phenotypes in patients identified with 1q21.1 rearrangements after referral for clinical microarray testing. We report clinical information for 55 probands with copy number variations (CNVs) involving proximal 1q21.1: 22 microdeletions and 20 reciprocal microduplications limited to proximal 1q21.1 and 13 microdeletions that include both the proximal and distal regions. Six individuals with proximal microdeletions have TAR syndrome. Three individuals with proximal microdeletions and two individuals with larger microdeletions of proximal and distal 1q21.1 have a ‘partial' TAR phenotype. Furthermore, one subject with TAR syndrome has a smaller, atypical deletion, narrowing the critical deletion region for the syndrome. Otherwise, phenotypic features varied among individuals with these microdeletions and microduplications. The recurrent, proximal 1q21.1 microduplications are enriched in our population undergoing genetic testing compared with control populations. Therefore, CNVs in proximal 1q21.1 can be a contributing factor for the development of abnormal phenotypes in some carriers. PMID:22317977

Rosenfeld, Jill A; Traylor, Ryan N; Schaefer, G Bradley; McPherson, Elizabeth W; Ballif, Blake C; Klopocki, Eva; Mundlos, Stefan; Shaffer, Lisa G; Aylsworth, Arthur S

2012-01-01

311

Characterization of the Na + \\/H + Exchanger in the Luminal Membrane of the Distal Nephron  

Microsoft Academic Search

.   In the rabbit as well as the rat, a Na+\\/H+ exchanger is expressed in the apical membrane of both the proximal and distal tubules of the renal cortex. Whereas the isoform\\u000a derived from the proximal tubule has been extensively studied, little information is available concerning the distal luminal\\u000a membrane isoform. To better characterize the latter isoform, we purified rabbit

D. Claveau; I. Pellerin; M. Leclerc; M. G. Brunette

1998-01-01

312

Endovascular treatment of proximal arsastomotic aneurysms after aortic prosthetic reconstruction  

SciTech Connect

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.

Tiesenhausen, Kurt [University Hospital Graz, Department of Vascular Surgery (Austria); Hausegger, Klaus A.; Tauss, Josef [University Hospital Graz, Department of Radiology (Austria); Amann, Wilfried; Koch, Guenter [University Hospital Graz, Department of Vascular Surgery (Austria)

2001-01-15

313

Endovascular Treatment of Proximal Anastomotic Aneurysms After Aortic Prosthetic Reconstruction  

SciTech Connect

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.

Tiesenhausen, Kurt [Department of Vascular Surgery, University Hospital Graz, Auenbruggerplatz 29, A-8036 Graz (Austria); Hausegger, Klaus A.; Tauss, Josef [Department of Radiology, University Hospital Graz, Auenbruggerplatz 29, A-8036 Graz (Austria); Amann, Wilfried; Koch, Guenter [Department of Vascular Surgery, University Hospital Graz, Auenbruggerplatz 29, A-8036 Graz (Austria)

2001-01-15

314

[Apophyseal avulsions of the pelvis and proximal femur].  

PubMed

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. PMID:8328062

Jacobsen, S

1993-07-01

315

Proximal and point detection of contaminated surfaces using Raman spectroscopy  

NASA Astrophysics Data System (ADS)

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.

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

316

Cushing proximal symphalangism and the NOG and GDF5 genes.  

PubMed

Proximal symphalangism (SYM1) is an autosomal-dominant developmental disorder of joint fusion. This disorder is best known from famous historical descriptions of two large kindred: Cushing's description in 1916 of the "straight-fingered" Brown family of Virginia and Drinkwater's description in 1917 of the British Talbot family of noble blood, descended from the English war hero John Talbot, the first Earl of Shrewsbury (1388-1453). Recent genetic studies link this phenotype to expression of abnormal genes at future joint sites: too little expression of NOG, a growth antagonist, or overexpression of GDF5, a growth agonist, results in cartilage overgrowth and bony fusion. This review unites in depth the first historical accounts of SYM1 with a clinical description and reviews the current understanding of the molecular mechanism underlying what is likely the oldest dominant trait ever studied. PMID:17994231

Plett, Sara K; Berdon, Walter E; Cowles, Robert A; Oklu, Rahmi; Campbell, John B

2008-02-01

317

Residential Proximity to Environmental Hazards and Adverse Health Outcomes  

PubMed Central

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

Maantay, Juliana A.; Chakraborty, Jayajit

2011-01-01

318

Graphene spintronics: Spin injection and proximity effects from first principles  

NASA Astrophysics Data System (ADS)

Ferromagnet/graphene (F/Gr) junctions are important building blocks for graphene spintronics. While simple models of spin injection are very successful for macroscopic metallic junctions, they reveal many deficiencies in describing F/Gr junctions. First-principles methods are key to assess such Gr-based junctions, but the computational cost is often too high. We focus on Ni(111)/Gr junctions and include van der Waals interactions from first principles, crucial for their correct description. We formulate a computationally inexpensive model to examine the nonuniformity and bias dependence of spin injection and elucidate proximity effects using spin polarization maps. Our results could extend the applicability of simple spin injection models in F/Gr junctions.

Lazi?, P.; Sipahi, G. M.; Kawakami, R. K.; Žuti?, Igor

2014-08-01

319

Spatial coordination in memrane proximal signaling in T-cells  

NASA Astrophysics Data System (ADS)

Membrane-proximal signaling initiates signaling networks of the T-cell which ultimately lead to the T-cell activation. Signal formation requires assembly of the several membrane proteins and successful cooperative interactions inside the complex. Diffusion and chemical reactions involved in the process are characterized by substantially different timescales. In this work we consider how the reaction-diffusion system described by the wide spectrum of timescales can be selective for the minute amounts of the signal (cognate peptide-MHC complex) over the large amounts of irrelevant targets (non-cognate peptide-MHC complex). Note that single distinction between relevant and irrelevant targets - the affinity to the T-cell receptor, is nonetheless sufficient to discriminate between two groups of targets. Moreover, proposed mechanism allows for signal cooperativity with non-cognate peptides amplifying the signal from cognate ones even though they can not signal by themselves. This kind of cooperativity has been observed in recent experiments.

Artyomov, Maxim N.; Lis, Mieszko; Chakraborty, Arup

2009-03-01

320

Proximity fingerprint of s{plus_minus} superconductivity.  

SciTech Connect

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.

Koshelev, A. E.; Stanev, V. (Materials Science Division)

2011-01-01

321

Orion Rendezvous, Proximity Operations, and Docking Design and Analysis  

NASA Technical Reports Server (NTRS)

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.

D'Souza, Christopher; Hanak, F. Chad; Spehar, Pete; Clark, Fred D.; Jackson, Mark

2007-01-01

322

Proximate composition and selected functional properties of Detarium microcarpum.  

PubMed

The proximate composition and functional properties of Detarium microcarpum seed flour were evaluated. The dehulled seed flour contained 3.5% moisture, 3.5% ash, 2.9% crude fiber, 15% crude fat, 37.1% crude protein and 39% carbohydrate. Functional properties showed bulk density of 0.86 g/cm3 for dehulled and 0.92 g/cm3 for undehulled flour. Water absorption capacity was 4.9 g/g for dehulled and 5.1 g/g for undehulled seed flour; oil absorption capacity was 0.75 g/g for dehulled. The emulsion activity was 4.4% and 4.3% for dehulled and undehulled, respectively. The results obtained above showed that the Detarium microcarpum seed flours have good nutritional quality and the functional properties confirmed their suitability for use in various food preparations. As a result, its present limited use should be expanded into additional opportunities. PMID:11678435

Akpata, M I; Miachi, O E

2001-01-01

323

Proximity sensors based on ball-lensed optical fibers  

NASA Astrophysics Data System (ADS)

Reflective sensors involving optical fibers are very popular due to low cost and EMI insensitive. In this paper, a new concept is described regarding proximity sensors based on ball-lensed optical fibers (PSBBOF). Two types of sensors are presented: (1) Type A with one transmitting and four receiving optical fibers and (2) Type B with one transmitting and eight receiving optical fibers. In both PSBBOF types ball-lensed optical fibers are used as a receiving line. Sensitive of both PSBBOF is compared to sensitive of sensors with the same configurations, but involving cleaved optical fibers. All developed sensors were tested at two wavelengths: 850 nm and 1300 nm. As a refractive surface the silicon wafer was used.

Guzowski, Bartlomiej; Cywinski, Marek; Lakomski, Mateusz

2014-08-01

324

Attentional breadth and proximity seeking in romantic attachment relationships.  

PubMed

The present study provides first evidence that attentional breadth responses can be influenced by proximity-distance goals in adult attachment relationships. In a sample of young couples, we measured attachment differences in the breadth of attentional focus in response to attachment-related cues. Results showed that priming with a negative attachment scenario broadens attention when confronted with pictures of the attachment figure in highly avoidant men. In women, we found that attachment anxiety was associated with a more narrow attentional focus on the attachment figure, yet only at an early stage of information processing. We also found that women showed a broader attentional focus around the attachment figure when their partner was more avoidantly attached. This pattern of results reflects the underlying action of attachment strategies and provides insight into the complex and dynamic influence of attachment on attentional processing in a dyadic context. PMID:23083097

Dewitte, Marieke; Koster, Ernst H W

2014-03-01

325

Distributed optical proximity sensor system - HexEYE  

NASA Technical Reports Server (NTRS)

A novel optical proximity sensor system, capable of measuring the distance to the orientation and the discontinuity at a local area of an object surface, was designed and evaluated for robotic applications. The sensor system gets its name, Hexagonal Eye, (HexEYE) from its shape where seven identical hexagonal sensing units were configured hexagonally into a compact geometric structure. The seven sensing units were grouped into multiple combinations of three sensing units to measure the surface orientation as well as surface discontinuity. The distinctive features of HexEYE are an order of magnitude increased in distance sensitivity by optimizing the curvature of a conical mirror, the enhanced measurement accuracy based on multiple levels of sensor fusion, and the compactness in size due to a sensing mechanism based on the Gaussian lens law. A prototype of single sensing unit has been built and was evaluated experimentally.

Lee, Sukhan

1992-01-01

326

Casimir energy and geometry: beyond the proximity force approximation  

NASA Astrophysics Data System (ADS)

We review the relation between the Casimir effect and geometry, emphasizing deviations from the commonly used proximity force approximation (PFA). We use, to this aim, the scattering formalism which is nowadays the best tool available for accurate and reliable theory-experiment comparisons. We first recall the main lines of this formalism when the mirrors can be considered to obey specular reflection. We then discuss the more general case where non-planar mirrors give rise to non-specular reflection with wavevectors and field polarizations mixed. The general formalism has already been fruitfully used for evaluating the effect of roughness on the Casimir force as well as the lateral Casimir force or Casimir torque appearing between corrugated surfaces. In this paper, we focus our attention to the case of the lateral force which should make possible in the future an experimental demonstration of the nontrivial (i.e. beyond PFA) interplay of the geometry and Casimir effect.

Reynaud, S.; Neto, P. A. Maia; Lambrecht, A.

2008-04-01

327

Rendezvous, proximity operations and capture quality function deployment report  

NASA Astrophysics Data System (ADS)

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.

Lamkin, Stephen L.

1991-12-01

328

Daily melatonin supplementation in mice increases atherosclerosis in proximal aorta.  

PubMed

Considerable evidence supports the hypothesis that LDL oxidation plays an important role in atherosclerosis. Even though high melatonin doses inhibit LDL oxidation in vitro, the effect of melatonin on atherosclerosis has never been studied. We have demonstrated that the feeding of hypercholesterolemic mice with an atherogenic diet supplemented with melatonin highly increases the surface of atherosclerotic lesions in the proximal aorta. These observations occur without detectable lipidic or glucidic phenotype alteration. Melatonin treatment increased highly the sensitivity of atherogenic lipoprotein to Cu(2+) and gamma-radiolysis generated oxyradical ex vivo oxidation during the fasting period. Moreover, these altered lipoproteins were less recognized by the LDL receptor metabolic pathway of murine fibroblasts while they transferred many more cholesteryl esters to murine macrophages. This study suggests that caution should be taken as regards high melatonin dosage in hypercholesterolemic patients. PMID:12051775

Tailleux, Anne; Torpier, Gérard; Bonnefont-Rousselot, Dominique; Lestavel, Sophie; Lemdani, Mohamed; Caudeville, Bernadette; Furman, Christophe; Foricher, Rachel; Gardes-Albert, Monique; Lesieur, Daniel; Rolando, Christian; Teissier, Elisabeth; Fruchart, Jean-Charles; Clavey, Véronique; Fievet, Catherine; Duriez, Patrick

2002-05-10

329

Antegrade versus retrograde intramedullary nailing of proximal third femur fractures.  

PubMed

The purpose of this study is to retrospectively review the results of proximal third femur fractures treated with retrograde nailing (RGN) and compare those results to a cohort from the same period treated with antegrade nailing (AGN). Adult patients with femur fractures within 10 cm of the lesser trochanter who were treated with intramedullary nails were reviewed. Two groups, patients treated with AGN (n = 35) and RGN (n = 34), were compiled. Demographic information, comorbidities, associated injuries, radiographic outcomes, complications, and secondary procedures were compared. There were two malunions in the AGN group and three in the RGN group. The AGN group had two nonunions while the RGN group had one. Subgroup analysis demonstrated that a higher body mass index (BMI) (p = .011) and a higher AO/OTA fracture classification (p = .019) were the only factors predictive of malunion. Regardless of starting point, there were no differences between groups in the number of secondary procedures, nonunions, malunions, or time until union. PMID:24393183

Kuhn, Kevin M; Ali, Ashley; Boudreau, John A; Cannada, Lisa K; Watson, John T

2013-01-01

330

Factors affecting minority population proximity to hazardous facilities  

SciTech Connect

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.

Nieves, L.A. [Argonne National Lab., IL (United States); Nieves, A.L. [Wheaton Coll., IL (United States)]|[Argonne National Lab., IL (United States)

1995-04-01

331

Automobile proximity and indoor residential concentrations of BTEX and MTBE  

SciTech Connect

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.

Corsi, Dr. Richard [University of Texas, Austin; Morandi, Dr. Maria [University of Texas Health Science Center, Houston; Siegel, Dr. Jeffrey [University of Texas, Austin; Hun, Diana E [ORNL

2011-01-01

332

Brightness of the Sun's small scale magnetic field: proximity effects  

E-print Network

The net effect of the small scale magnetic field on the Sun's (bolometric) brightness is studied with realistic 3D MHD simulations. The direct effect of brightening within the magnetic field itself is consistent with measurements in high-resolution observations. The high 'photometric accuracy' of the simulations, however, reveal compensating brightness effects that are hard to detect observationally. The influence of magnetic concentrations on the surrounding nonmagnetic convective flows (a 'proximity effect') reduces the brightness by an amount exceeding the brightening by the magnetic concentrations themselves. The net photospheric effect of the small scale field (~ -0.34% at a mean flux density of 50 G) is thus negative. We conclude that the main contribution to the observed positive correlation between the magnetic field and total solar irradiance must be magnetic dissipation in layers around the temperature minimum and above (not included in the simulations). This agrees with existing inferences from obs...

Thaler, I

2014-01-01

333

Displaced proximal humeral fractures: an Indian experience with locking plates  

PubMed Central

Background The treatment of displaced proximal humerus fractures, especially in elderly, remains controversial. The objective of this study was to evaluate functional outcome of locking plate used for fixation of these fractures after open reduction. We also attempted to evaluate the complications and predictors of loss of fixation for such an implant. Methods Over two and a half years, 56 patients with an acute proximal humerus fracture were managed with locking plate osteosynthesis. 47 of these patients who completed a minimum follow up of 1 year were evaluated using Constant score calculation. Statistical analysis was done using SPSS 16 and a p value of less than 0.05 was taken as statistically significant. Results The average follow up period was around 21.5 months. Outcomes were excellent in 17%, good in 38.5%, moderate in 34% while poor in 10.5%. The Constant score was poorer for AO-OTA type 3 fractures as compared to other types. The scores were also inferior for older patients (> 65 years old). Complications included screw perforation of head, AVN, subacromial impingement, loss of fixation, axillary nerve palsy and infection. A varus malalignment was found to be a strong predictor of loss of fixation. Conclusion Locking plate osteosynthesis leads to satisfactory functional outcomes in all the patients. Results are better than non locking plates in osteoporotic fractures of the elderly. However the surgery has steep learning curve and various complications could be associated with its use. Nevertheless we believe that a strict adherence to the principles of locking plate use can ensure good result in such challenging fractures. PMID:20731844

2010-01-01

334

Childhood cancer and residential proximity to power lines  

PubMed Central

In the United Kingdom Childhood Cancer Study, a population-based case–control study covering the whole of England, Scotland and Wales, measured power-frequency magnetic fields were not found to be associated with risk for any malignancy. To examine further the risk associated with residential proximity to electricity supply equipment, distances to high-voltage lines, underground cables, substations and distribution circuits were collected for 3380 cases and 3390 controls. Magnetic field exposure from this equipment was calculated using distance, load and other circuit information. There was no evidence that either proximity to electrical installations or the magnetic field levels they produce in the UK is associated with increased risk of childhood leukaemia or any other cancer. Odds ratios of 0.73 (95% CI = 0.42–1.26) for acute lymphoblastic leukaemia, 0.75 (95% CI = 0.45–1.25) for all leukaemias, 1.08 (95% CI = 0.56–2.09) for central nervous system cancers and 0.92 (95% CI = 0.64–1.34) for all malignancies were obtained for residence within 50?m of an overhead line. When individuals with a calculated magnetic field exposure ? 0.2??T were compared to those in a reference category of exposure <0.1??T, odds ratios of 0.51 (95% CI = 0.11–2.33) for acute lymphoblastic leukaemia, 0.41 (95% CI = 0.09–1.87) for total leukaemia, 0.48 (95% CI =0.06–3.76) for central nervous system cancers and 0.62 (95% CI = 0.24–1.61) for all malignancies were obtained. © 2000 Cancer Research Campaign http://www.bjcancer.com PMID:11076671

2000-01-01

335

Urea secretion by the straight segment of the proximal tubule.  

PubMed Central

Studies utilizing in vitro microperfusion were designed to examine whether urea is actively or passively transported across superficial and juxtamedullary straight segments of rabbit proximal tubules. With perfusate and bath solutions containing 1 mM urea and electrolytes similar to normal plasma, the efflux (lumen-to-bath) isotopic permeability (X 10(-5) cm s-1) of superficial segments was 1.37 +/- 0.16 and of juxtamedullary segments was 2.14 +/- 0.20. In the same tubules, the influx (bath-to-lumen) isotopic permeability was 3.70 +/- 0.35 in superficial segments and 4.75 +/- 0.37 in juxtamedullary segments. Despite net water movement in the opposite direction (0.5 nl mm-1 min-1), the influx rate was significantly higher than the efflux rate of urea in both groups. With a low perfusion rate (2 nl/min) and equivalent specific activities of [14C]urea in bath and perfusate, the collected-to-perfused ratio of [14C]urea, corrected for volume marker change, was 1.07 +/- 0.01 in superficial and 1.09 +/- 0.01 in juxtamedullary nephrons, thus indicating net secretion in both segments. In separate studies urea influx was inhibited by hypothermia (decrease from 37 degrees to 28 degrees C), by phloretin (0.1 mM in bath), by cyanide (1 mM), but not by probenecid (0.2 mM). In each case the inhibition was highly significant and reversible. These data suggest that urea is actively secreted by the straight segments of both the superficial and juxtamedullary proximal tubules. These segments may, therefore, contribute significantly to the high urea concentration found at the bend of Henle's loop by micropuncture. PMID:956389

Kawamura, S; Kokko, J P

1976-01-01

336

Acquired Fanconi syndrome with proximal tubular cytoplasmic fibrillary inclusions of ? light chain restriction.  

PubMed

Light chain proximal tubulopathy is a rarely reported entity associated with plasma cell dyscrasia that classically manifests as acquired Fanconi syndrome and is characterized by the presence of ?-restricted crystals in the proximal tubular cytoplasm. We herein present a case of multiple myeloma with Fanconi syndrome and acute kidney injury due to light chain proximal tubulopathy with light chain cast nephropathy. Prominent phagolysosomes and numerous irregularly shaped inclusions with a fibrillary matrix in the cytoplasm of the proximal tubules were identified on electron microscopy. A monotypic light chain of the ? type was detected in the distal tubular casts, proximal tubular cytoplasmic lysosomes and fibrillary inclusions on immunofluorescence and immune electron microscopy. This case underscores the importance of conducting careful ultrastructural investigations and immunocytologic examinations of light chains for detecting and diagnosing light chain proximal tubulopathy. PMID:24429451

Yao, Ying; Wang, Su-Xia; Zhang, You-Kang; Wang, Yan; Liu, Li; Liu, Gang

2014-01-01

337

Osteoblast maturation occurs in overlapping proximal-distal compartments during fin regeneration in zebrafish  

PubMed Central

During fin regeneration, osteoblasts must continually differentiate for outgrowth of the bony fin rays. Bone maturity increases in a distal-proximal manner, and osteoblast maturation can be detected similarly when following gene expression. We find that early markers for osteoblast differentiation are expressed in a discrete domain at the distal end of the fin, just proximal to the adjacent germinal compartment of dividing cells. Matrix genes, required at later stages developmentally, are expressed in a population of cells proximally to the early genes. A marker for mature osteoblasts is expressed in cells further proximal. These domains of gene expression are partially overlapping, perhaps revealing additional levels of osteoblast maturity. We suggest a model for growth where new cells are continually added to the distal-most osteoblast compartment, while osteoblasts in more proximal locations differentiate, thus translating developmental time to location on the proximal-distal axis. PMID:19842180

Brown, Andrew M.; Fisher, Shannon; Iovine, M. Kathryn

2009-01-01

338

The proximate, mineral, and toxicant compositions of four possible food security crops from southeastern Nigeria.  

PubMed

The proximate, nutritional, and antinutritional compositions of the raw, cooked, and roasted samples of four Nigerian indigenous seeds-Sphenostylis stenocarpa, Pentaclethra macrophylla, Mucuna flagellipes, and Citrullus colocynthis-were evaluated. Also estimated were zinc and divalent cation bioavailability of the seeds using millimolar ratios/kg dry weight of [calcium]/[phytate], [phytate]/[zinc], [calcium][phytate]/[Zn], and [phytate]/[total phosphorus]. The results obtained revealed that the seeds of P. macrophylla and C. colocynthis had high protein and lipid levels. All the seeds were also found to have high energy value and low moisture content. Mineral analysis showed the presence of Na, K, Ca, and Mg in appreciable quantities and Zn, I, Fe, and Se in minute quantities. Antinutritional analyses indicated the presence of traces of tannin, oxalate, phytate, saponin, and cyanide in the samples. The various processing techniques had significant (P???.05) effects on the measured parameters. The calculated [Ca][phytate]/[Zn] molar ratios revealed that these seeds had values above the critical level of 0.5?mL/kg, thus indicating reduced bioavailability of zinc. In view of the high nutrient contents, low antinutritional contents after processing, and their superabundance, these seeds could be cheap nutrient sources. The implications of these findings with regards to food security are enormous. PMID:20828321

Ojiako, Okey A; Ogbuji, Chiza A; Agha, Ngozi C; Onwuliri, Viola A

2010-10-01

339

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

PubMed Central

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 ?-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

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

2013-01-01

340

Putative interaction of brush cells with bicarbonate secreting cells in the proximal corpus mucosa  

PubMed Central

The gastric epithelium is protected from the highly acidic luminal content by alkaline mucus which is secreted from specialized epithelial cells. In the stomach of mice strong secretion of alkaline fluid was observed at the “gastric groove,” the border between corpus and fundus mucosa. Since this region is characterized by numerous brush cells it was proposed that these cells might secrete alkaline solution as suggested for brush cells in the bile duct. In fact, it was found that in this region multiple cells express elements which are relevant for the secretion of bicarbonate, including carbonic anhydrase (CAII), the cystic fibrosis transmembrane conductance regulator (CFTR) and the Na+/H+ exchanger (NHE1). However, this cell population was distinct from brush cells which express the TRP-channel TRPM5 and are considered as putative sensory cells. The location of both cell populations in close proximity implies the possibility for a paracrine interaction. This view was substantiated by the finding that brush cells express prostaglandin synthase-1 (COX-1) and the neighboring cells a specific receptor type for prostaglandins. The notion that brush cells may be able to sense a local acidification was supported by the observation that they express the channel PKD1L3 which contributes to the acid responsiveness of gustatory sensory cells. The results support the concept that brush cells may sense the luminal content and influence via prostaglandins the secretion of alkaline solution. PMID:23874305

Eberle, Julia Anna-Maria; Muller-Roth, Kai L.; Widmayer, Patricia; Chubanov, Vladimir; Gudermann, Thomas; Breer, Heinz

2013-01-01

341

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

PubMed

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(+)/K(+) 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(+)/K(+) 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. PMID:24907557

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

2014-09-01

342

Studies on the Mechanism of 4-Aminophenol-induced Toxicity to Renal Proximal Tubules  

Microsoft Academic Search

4-Aminophenol (PAP) is known to cause nephrotoxicity in the rat where it produces selective necrosis to renal proximal tubules. The aim of this work was to investigate the toxicity of PAP and its known nephrotoxic metabolite 4-amino-3-S-glutathionylphenol using a well defined suspension of rabbit renal proximal tubules. PAP at a concentration of 0.5 mM and 1 mM caused proximal tubule

Edward A. Lock; Theresa J. Cross; Rick G. Schnellmann

1993-01-01

343

PATERNAL WARMTH AND PROXIMITY / Veneziano 2000 World Cultures 11(2): 138-151  

E-print Network

for understanding parent- child relations in comparative research. However, the strong correlation between significant related to interpersonal violence, whereas neither maternal warmth nor fathers' proximity remained

White, Douglas R.

344

Low micromolar concentrations of cadmium and mercury ions activate peritubular membrane K+ conductance in proximal tubular cells of frog kidney.  

PubMed

The present study was designed to investigate the acute effects of extracellular low micromolar concentrations of cadmium and mercury ions on the peritubular cell membrane potential and its potassium selectivity in proximal tubular cells of the frog kidney. Peritubular exposure to 3 micromol/L Cd(2+) or 1 micromol/L Hg(2+) led to a rapid, sustained and reversible hyperpolarization of the peritubular cell membrane, paralleled by an increase in fractional K(+) conductance. Peritubular barium abolished hyperpolarization of the peritubular cell membrane to peritubular 3 micromol/L Cd(2+) or 1 micromol/L Hg(2+). Perfusing the lumen with 10 mmol/L l-alanine plus/minus 3 micromol/L Cd(2+) or Hg(2+) did not modify rapid depolarization and rate of slow repolarization of the peritubular cell membrane potential. In conclusion, low micromolar concentrations of Cd(2+) and Hg(2+) increase K(+) conductive pathway in the peritubular cell membrane and in this way can enhance ability of proximal renal tubular cells to maintain the driving force for electrogenic Na(+) and substrate reabsorption. PMID:18255327

Nesovic-Ostojic, Jelena; Cemerikic, Dusan; Dragovic, Simon; Milovanovic, Aleksandar; Milovanovic, Jovica

2008-03-01

345

The distance of proximal resection margin dose not significantly influence on the prognosis of gastric cancer patients after curative resection  

PubMed Central

Purpose It is well known that the curative resection with an adequate proximal margin length is the most effective treatment in gastric cancer. However, despite surgeon's effort to achieve a sufficient proximal margin length, it is often difficult to obtain a recommended proximal margin length in some cases. Therefore, this study was planned to investigate the impact of the length of proximal margin on prognosis of overall survival. Methods Between June 1992 and December 2010, 1,888 gastric cancer patients who underwent gastrectomy with curative intent were reviewed. According to tumor's location (total vs. subtotal gastrectomy), pathologic T staging, and differentiation, univariate and multivariate analyses were performed to evaluate the impact of the discrepancies of proximal margin length on overall survival. Also, the impact of the discrepancies of proximal margin length on local recurrence was assessed. Results The 5-year survival rate of positive proximal margin group was 5.9%. In negative proximal margin groups, multivariate analysis showed that the discrepancies of proximal margin length have no impact on overall survival. Kaplan-Meier analyses showed that there is no association between discrepancy of proximal margin length and local recurrence. Conclusion It takes effort to secure a negative proximal margin in the surgical treatment of gastric cancer because of the poor prognosis of positive proximal margin. In negative proximal margin patients, there's no need to achieve an additional proximal margin length for long-term survival benefit because there was no impact of proximal margin length on overall survival and local recurrence. PMID:25368847

Kim, Min Gyu; Lee, Ju-Hee; Ha, Tae Kyung

2014-01-01

346

Proximal row carpectomy--an adequate procedure in carpal collapse  

PubMed Central

Proximal row carpectomy (PRC) is an established procedure in the treatment of advanced radiocarpal arthritis. The aim of this study was to evaluate the individual, functional and radiological results in relation to the initial diagnosis. Seventeen patients (15 men, two women), who had undergone PRC, were evaluated. Their average age at the time of the operation was 48 years (range 21–70 years). The most frequent diagnosis leading to PRC was scaphoid non-union advanced collapse (SNAC), which was observed in nine patients, while in three cases each the condition treated had been scapholunate advanced collapse (SLAC) and perilunate dislocation, and in two cases, Kienboeck’s disease. At the time of the follow-up examination (median 65.41 months), a significant improvement in the range of movement was seen. While only four (36%) of the patients with SNAC had radiological signs of arthrosis of the radiocapitate joint, visible radiological involvement was noted in all patients who underwent PRC due to scapholunate dissociation and perilunate dislocation. The results of this study show that PRC is a good way of achieving long-term improvement of the degree of subjective freedom from symptoms and of the functional range of movement. Interruption of ligamentous structures, as in scapholunate dissociation and perilunate dislocation, seems to influence the radiological outcome. PMID:17089124

Martini, Abdul K.; Daecke, Wolfgang

2006-01-01

347

Spatial Instabilities, Homogeneities and Proximity Effects: Highly Correlated Metals  

SciTech Connect

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 ? in the OV samples; (4) Inverse correlation between ICRN and ? in OV samples; (5) Degradations of the superconductivity of BSCCO by high current density.

Dynes, Robert C.

2008-10-31

348

Effects of warning validity and proximity on responses to warnings.  

PubMed

The effects of a warning's validity and display characteristics on the responses to binary warnings were studied in a categorization task that resembled the control of a simulated production environment. Students performed a visual signal detection task and were aided by a binary warning indicator. Experimental conditions differed in the validity of the warning and its proximity to the judged stimulus. Participants' performance improved over the course of the experiment, and they partly adjusted their responses to the validity of the warnings but continued to respond to nonvalid warnings throughout the experiment. It was particularly difficult to ignore the nonvalid information when it was integrated with the continuous information. There was evidence for nonoptimal use of the information from the warning system, whether it was valid or not valid. The results indicate a possible distinction between two dimensions of users' trust in warning systems: compliance and reliance. Actual or potential implications of this research include improved warning design based on analysis of system and operator characteristics. PMID:12002005

Meyer, J

2001-01-01

349

A tortuous proximal urethra in urorectal septum malformation sequence?  

PubMed

We observed a newborn boy with urorectal septum malformation sequence. Anomalies of the genitalia and rectum were present. He expired on the first day of life, due to severe lung hypoplasia. Autopsy showed a colon that ended in a blind sac, an enlarged bladder with no grossly visible urethra, and dysplastic kidneys. A cone-shaped tissue at the usual site of the bladder outlet contained tortuous and slit-like lumina, suggesting an undeveloped proximal urethra. The urethral structure was lined by transitional epithelium with squamous metaplasia. Many small buds-lined with columnar epithelium-branched from the urethral structure. These ductal buds lined with columnar epithelium stained for prostatic acid phosphatase. Basal cells surrounding the ductal buds stained for p63 and high molecular weight cytokeratin-supporting an interpretation that the buds were early prostatic ducts with normal histology. To our knowledge, these are the first histological images of an undeveloped, obstructed urethra associated with the urorectal septum malformation sequence. PMID:24665006

Lin, Henry J; Lugo, Hector; Tran, Thu; Tovar, Jason P; Corral, Julia; Zork, Noelia M; Smith, Lynne M; French, Samuel W; Barajas, Luciano

2014-05-01

350

Collaboration range: Effects of geographical proximity on article impact  

NASA Astrophysics Data System (ADS)

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).

Apolloni, Andrea; Rouquier, Jean-Baptiste; Jensen, Pablo

2013-09-01

351

Treeline proximity alters an alpine plant-herbivore interaction.  

PubMed

Rising treeline threatens the size and contiguity of alpine meadows worldwide. As trees encroach into previously open habitat, the movement and population dynamics of above-treeline alpine species may be disrupted. This process is well documented in studies of the Rocky Mountain apollo butterfly (Parnassius smintheus). However, subtler consequences of treeline rise remain poorly understood. In this study, we examine whether treeline proximity affects feeding behaviour of P. smintheus larvae, due to altered habitat affecting the distribution and availability of their host plant, lance-leaved stonecrop (Sedum lanceolatum). Understanding differential larval exploitation of food resources in relation to the treeline is an important step in predicting the consequences of continued treeline rise. Parnassius smintheus larvae feed more intensively on S. lanceolatum away from the treeline despite the relative paucity of hosts in these areas, and despite higher fitness penalties associated with the plant's herbivory-induced chemical defenses. Sedum lanceolatum growing near the treeline is less attractive, and therefore represents a less significant resource for P. smintheus larvae than its abundance might imply. If treeline rise continues, we suggest that this pattern of altered resource exploitation may represent a mechanism by which larvae are adversely affected even while adult movement among and within meadows appears sufficient for maintaining population health, and total host availability seems ample. PMID:21184238

Illerbrun, Kurt; Roland, Jens

2011-05-01

352

Autonomous control procedures for shuttle rendezvous proximity operations  

NASA Technical Reports Server (NTRS)

The results are presented of a study which uses fuzzy sets to model a Space Shuttle pilot's reasoning and actions while performing rendezvous proximity operation maneuvers. In this model fuzzy sets are used to simulate smooth and continuous actions as would be expected from an experienced pilot and to simulate common sense reasoning in the decision process. The present model assumes visual information available to the Shuttle pilot from the Shuttle Crew Optical Alignment Sighting (COAS) device and the overhead window and rendezvous radar sensor information available to him from an onboard display. This model will be used in a flight analysis simulator to perform studies requiring a large number of runs, each of which currently needs an engineer in the loop to supply the piloting decisions. This work has much broader implications in control of robots such as the Flight Telerobotic Servicer, in automated pilot control and attitude control, and in advisory and evaluation functions that could be used for flight data monitoring or for testing of various rule sets in flight preparation.

Lea, Robert N.; Mitchell, Eric V.; Goodwin, Mary Ann

1987-01-01

353

Interactive orbital proximity operations planning system instruction and training guide  

NASA Technical Reports Server (NTRS)

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.

Grunwald, Arthur J.; Ellis, Stephen R.

1994-01-01

354

Anion permeabilities of the isolated perfused rabbit proximal tubule.  

PubMed

Electrophysiologic and isotopic techniques were used to characterize the anion permeabilities of isolated perfused rabbit proximal tubules (S2 segments). Tubules were differentiated into chloride- and sodium-selective populations by electrophysiologic rather than by anatomic criteria. The tubules were studied under conditions that inhibited active sodium transport. The isotopic chloride permeability coefficient was 5.5 +/- 0.6 X 10(-5) cm/s (n = 19) for chloride-selective tubules and 3.2 +/- 0.6 X 10(-5) cm/s (n = 15) for sodium-selective tubules. The isethionate permeability coefficient was 1.1 +/- 0.2 X 10(-5) cm/s (n = 23) and did not vary with sodium or chloride selectivity. The variation of oxyanion permeability (bicarbonate, isethionate, and cyclamate) relative to chloride resulted from changes in chloride permeability, per se, rather than any change in the oxyanion permeability. A consistent relation between bicarbonate and isethionate permeability permitted the permeability of bicarbonate ion to be estimated at 1.3 X 10(-5) cm/s. The mechanism of ion selectivity appears to be different for the two populations of tubules. Chloride-selective tubules appear to hve relatively small pathways that do not contain fixed-charge sites. In contrast, sodium-selective tubules may have permeation pathways that contain fixed negative-charge sites. PMID:7065249

Warnock, D G; Yee, V J

1982-04-01

355

Proximity effect in superconductor/conical magnet heterostructures.  

PubMed

The presence of a spin-flip potential at the interface between a superconductor and a ferromagnetic metal allows for the generation of equal-spin spin-triplet Cooper pairs. These Cooper pairs are compatible with the exchange interaction within the ferromagnetic region and hence allow for the long-range proximity effect through a ferromagnet or half-metal. One suitable spin-flip potential is provided by incorporating the conical magnet Holmium (Ho) into the interface. The conical magnetic structure is characterised by an opening angle ? with respect to the crystal c-axis and a turning (or pitch) angle ? measuring the rotation of magnetisation with respect to the adjacent layers. Here, we present results showing the influence of conical magnet interface layers with varying ? and ? on the efficiency of the generation of equal-spin spin-triplet pairing. The results are obtained by self-consistent solutions of the microscopic Bogoliubov-de Gennes equations in the clean limit within a tight-binding model of the heterostructure. In particular, the dependence of unequal-spin and equal-spin spin-triplet pairing correlations on the conical magnetic angles ? and ? are discussed in detail. PMID:24934542

Fritsch, D; Annett, J F

2014-07-01

356

Norepinephrines effect on adenosine transport in the proximal straight tubule  

SciTech Connect

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.

Barfuss, D.W.; McCann, W.P.; Katholi, R.E.

1986-03-01

357

Catalyst proximity effects on the growth rate of Si nanowires  

NASA Astrophysics Data System (ADS)

Si nanowires grown by the vapor-liquid-solid (VLS) mechanism were fabricated using Au-catalyst nanoparticles and silane (SiH4) gas on Si substrates. Au was deposited on the substrate surface both by electron-beam evaporation and Au-colloid deposition. Both kinking defects and vertical nanowire epitaxy on Si ?111? substrates were found to be directly related to SiH4 flow rate. A correlation between Au-colloid dilution and the nanowire growth rate was also observed, with the growth rate increasing with increasing concentrations of Au-catalyst particles on the wafer surface. Systematic experiments relating the nanowire growth rate to the proximity of nearest-neighbor Au particles and Au reservoirs were carried out, and the results were found to be in good agreement with a SiH4 reaction model, which associates decomposition to form SiH2 with higher nanowire growth rates. Implications toward the realization of VLS-grown single nanowire transistors are discussed.

Boles, S. T.; Fitzgerald, E. A.; Thompson, C. V.; Ho, C. K. F.; Pey, K. L.

2009-08-01

358

Ultrafast gating of proximity-focused microchannel-plate intensifiers  

SciTech Connect

Proximity-focused, microchannel-plate (MCP) image intensifiers have been used at Los Alamos for many years to allow single frame film and video exposure times in the range of 2.5 to 10 ns. There is now a program to reduce gating times to < 1 ns. This paper reviews previous work and the problems in achieving good resolution with gating times of < 1 ns. The key problems involve applying fast electrical gating signals to the tube elements. We present computer modeling studies of the combined tube, tube connection, and pulser system and show that low photocathode surface resistivity must be obtained to permit fast gating between the photocathode and the MCP input. We discuss ways of making low-resistivity S20 photocathodes, using gallium arsenide photocathodes, and various means of gating the tubes. A variety of pulser designs are being experimentally evaluated including spark gaps, avalanche transistors, Krytron tubes with sharpening gaps, step recovery diodes, and photoconductive elements (PCEs). The results of these studies are presented. Because of the high capacitances involved in most gating schemes, the tube connection geometry must be of low-impedance design, and our solution is presented. Finally, ways of testing these high-speed camera systems are discussed.

Lundy, A.S.; Iverson, A.E.

1982-01-01

359

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

PubMed Central

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 ?-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

Walmsley, Scott J.; Freund, Dana M.

2012-01-01

360

Wall proximity corrections for hot-wire readings in turbulent flows  

NASA Technical Reports Server (NTRS)

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.

Hebbar, K. S.

1980-01-01

361

Does proximity to coal-fired power plants influence fish tissue mercury?  

E-print Network

Does proximity to coal-fired power plants influence fish tissue mercury? Dana K. Sackett · D. Derek+Business Media, LLC 2010 Abstract Much of the mercury contamination in aquatic biota originates from coal of contaminated fish. In this study, we quantified the relative importance of proximity to coal-fired power plants

362

The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition  

E-print Network

The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition Thomas K scyphozoan jellyfish (Cyanea capillata, Rhizostoma octopus and Chrysaora hysoscella). First, bomb-calorimetry). These proximate data were subsequently converted to energy densities. The two techniques (bomb- calorimetry

Hays, Graeme

363

ORDERING VERSUS GRABBING: THE INFLUENCE OF TEMPORAL PROXIMITY ON IMPULSIVE ONLINE BUYING BEHAVIOR  

Microsoft Academic Search

A study is proposed to test the effects of temporal proximity between the encounter of a stimulus and the receipt of the product on impulsive online buying behavior. In traditional retail settings, temporal proximity between exposure to a stimulus and receipt of the product is an important factor influencing impulsive buying behavior. In most online shopping situations however, there is

Christoph Schneider

364

The role of reciprocity and proximity in junior high school friendships  

Microsoft Academic Search

The relationship of reciprocity, sex, and race to friendship proximity in adolescent friendships was studied. Intelligence, personality, physical attractiveness, popularity, and proximity were measured for 136 junior high school students. Subjects were classified as either having reciprocated or nonreciprocated friendships. Reciprocated adolescents were perceived as more attractive, had higher social status, and were more committed to their best friend than

M. L. Clark; Marla Ayers

1988-01-01

365

Proximal Postural Control Mechanisms May Be Exaggeratedly Adopted by Individuals With Peripheral Deficiencies: A Review  

Microsoft Academic Search

In quiet stance, it is understood that healthy individuals control their posture primarily by a peripheral mechanism for anteroposterior sway and by a proximal mechanism for medialateral sway. The authors proposed the hypothesis that patients suffering from disease-related deficiencies, at their feet and legs, may exaggeratedly adopt proximal control mechanisms at their hip in the anteroposterior and medialateral axes. They

Cédrick T. Bonnet; Marc Lepeut

2011-01-01

366

Hypoxia stimulates proximal tubular cell matrix production via a TGF-?1-independent mechanism  

Microsoft Academic Search

Hypoxia stimulates proximal tubular cell matrix production via a TGF-?1-independent mechanism. Tubulointerstitial fibrosis is characterized by tubular basement membrane thickening and accumulation of interstitial extracellular matrix (ECM). Since chronic low-grade hypoxia has been implicated in the pathogenesis of fibrosis and proximal tubular epithelial cells (PTE) are sensitive to oxygen deprivation, we hypothesized that hypoxia may stimulate ECM accumulation. In human

Chrystalla Orphanides; Leon G Fine; Jill T Norman

1997-01-01

367

Classifying Proximity Soundings with Self-Organizing Maps toward Improving Supercell and Tornado Forecasting  

E-print Network

Classifying Proximity Soundings with Self-Organizing Maps toward Improving Supercell and Tornado important when forecasting tornadoes. 1. Introduction A wide breadth of work examining supercell thunder not preclude the possibility of supercells or tornadoes. Proximity sound- ings obtained from radiosonde

368

Staged external and internal less-invasive stabilisation system plating for open proximal tibial fractures  

Microsoft Academic Search

High-energy proximal tibial fractures are complex injuries that may lead to significant complications. Staged treatment of these injuries using a spanning external fixator across the knee joint in the acute setting decreases the incidence of complications. This article is a prospective evaluation of outcomes using a two-stage procedure for treatment of 15 patients who sustained open proximal tibial fractures between

Ching-Hou Ma; Chin-Hsien Wu; Shang-Won Yu; Cheng-Yo Yen; Yuan-Kun Tu

2010-01-01

369

Magnetic resonance neurography of median neuropathies proximal to the carpal tunnel.  

PubMed

This review provides magnetic resonance neurography (MRN) imaging appearances of median neuropathy proximal to the carpal tunnel. Carpal tunnel syndrome (CTS) and its imaging have been extensively described in the literature; however, there is a relative paucity of information on the MR imaging appearances of different pathologies of the median nerve proximal to the carpal tunnel. PMID:22426804

Thawait, Gaurav K; Subhawong, Ty K; Thawait, Shrey K; Andreisek, Gustav; Belzberg, Alan J; Eng, John; Carrino, John A; Chhabra, Avneesh

2012-06-01

370

Investigation of Proximity Losses in a High Speed Brushless Permanent Magnet Motor  

Microsoft Academic Search

This paper presents a finite element investigation into the proximity losses in brushless AC permanent magnet motors used in hybrid\\/electric vehicle applications. The proximity effect in winding conductors is as a result of eddy-currents caused by magnetic fields generated by nearby conductors. This paper considers the influence of the conductor shape and disposition on the losses for a given stator

Phil H. Mellor; Rafal Wrobel; Neville McNeill

2006-01-01

371

Proximate Chemical Composition and Fatty Acids of Three Small Coastal Pelagic Species  

E-print Network

high level of 22:6w3, but in general the fatty acid profiles of the three species were similar and didProximate Chemical Composition and Fatty Acids of Three Small Coastal Pelagic Species MALCOLM B. HALE Introduction Information on the proximate chem- ical composition and fatty acid profiles

372

Effect of distension and feeding on phasic changes in human proximal gastric tone  

Microsoft Academic Search

BACKGROUND: Proximal stomach by virtue of its property of accommodation acts as a reservoir for the ingested food, but its role in emptying and the factors modulating it remain unexplored. AIM: To assess the effects of distension and of feeding on proximal gastric tone. SUBJECTS: 14 healthy volunteers with no current or past history of any gastro-intestinal symptoms. METHODS: Isobaric

N K Ahluwalia; D G Thompson; J Barlow

1996-01-01

373

An Analysis of the Relationship between Residents' Proximity to Water and Attitudes about Resource Protection  

Microsoft Academic Search

This article investigates attitudes toward water resource protection among residents in varying proximities to resources, specifically to identify attitudinal differences and the extent to which nearness and adjacency explain attitudes. Proximity was evaluated by measured distances using GIS and reported closeness from a mail survey. Five attitudinal dimensions were assessed: general importance of resource protection, support for government, regulations, and

Kelli L. Larson; Mary V. Santelmann

2007-01-01

374

Comparative study of iliac crest and proximal femur histomorphometry in normal patients  

Microsoft Academic Search

The relation between the bone histomorphometric profile of the iliac crest and regions of the proximal femur was investigated. In the proximal femur four blocks were selected, representing the subchondral principal compressive (SPC) and tensile (SPT) regions, the zone near the medial cortex in the principal compressive region (MPC), and the zone medial to the greater trochanter (MGT). Undecalcified tissue

N L Fazzalari; R J Moore; B A Manthey; B Vernon-Roberts

1989-01-01

375

Distributed Proximity Maintenance in Ad Hoc Mobile , Leonidas J. Guibas2  

E-print Network

Distributed Proximity Maintenance in Ad Hoc Mobile Networks Jie Gao1 , Leonidas J. Guibas2 is possi- ble, in that maintenance of the proximity information only requires each node to exchange Collaborating intelligent mobile node scenarios appear in a wide variety of applica- tions. Consider aircraft

Gao, Jie

376

Distributed Proximity Maintenance in Ad Hoc Mobile Networks Leonidas J. Guibas  

E-print Network

Distributed Proximity Maintenance in Ad Hoc Mobile Networks Jie Gao Leonidas J. Guibas An Nguyen proximity related tasks. A lightweight and fully distributed implementation is possible, in that maintenance variety of applications. Consider aircraft flying in formation: each plane must be aware of the locations

Gao, Jie

377

The Effect of Ethnolinguistic Differences on Proximity between Cantonese and Mandarin Speaking Children.  

ERIC Educational Resources Information Center

Examined effects of ethnolinguistic differences on social proximity between Cantonese- and Mandarin-speaking Chinese children in a day care center. Found that each group of children was more likely to be in closer proximity to children speaking their own language than to children speaking the other language during free choice floor- and group-time…

Leung, Lanna Oi-Ling; Lewis, George F.

1999-01-01

378

Proximity sounding analysis for derechos and supercells: an assessment of similarities and differences  

Microsoft Academic Search

Proximity soundings (within 2 h and 167 km) of derechos (long-lived, widespread damaging convective windstorms) and supercells have been obtained. More than 65 derechos, accompanied by 115 proximity soundings, are identified during the years 1983 to 1993. The derechos have been divided into categories according to the synoptic situation: strong forcing (SF), weak forcing (WF), and “hybrid” cases (which are

Charles A. Doswell; Jeffry S. Evansb

2003-01-01

379

Combined Proximal and Distal Realignment Procedures to Treat the Habitual Dislocation of the Patella in Adults  

Microsoft Academic Search

Background: Habitual dislocation of the patella (HDP) is a rare condition. Many surgical procedures using proximal realignment have been reported to treat HDP in children, with around 80% satisfactory results. However, few articles have addressed the treatment of HDP associated with high-grade patellofemoral chondromalacia in adults.Hypothesis: A combination of proximal and distal realignment procedures of the patella will reduce pain

Hsain-Chung Shen; Kuo-Hua Chao; Guo-Shu Huang; Ru-Yu Pan; Chian-Her Lee

2007-01-01

380

Proximal medial tibial biplanar retrotubercle open wedge osteotomy in medial knee arthrosis  

Microsoft Academic Search

The patellar tendon length changes and patella infera occurs in medial open wedge osteotomies. We hypothesized that patellar tendon length in the sagittal plane would not change in a proximal medial tibial biplanar retrotubercle open wedge osteotomy. Proximal medial tibial biplanar retrotubercle open wedge osteotomies were conducted on 23 knees of 22 patients; the mean patient age was 59±7years (range,

Irfan Esenkaya; Koray Unay

381

Estimation of 1D proximity budget impacts due to light source for advanced node design  

NASA Astrophysics Data System (ADS)

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.

Peng, R. C.; Wu, Tony; Liu, H. H.

2014-03-01

382

The morphologic spectrum and clinical significance of light chain proximal tubulopathy with and without crystal formation.  

PubMed

The renal diseases most frequently associated with myeloma include amyloidosis, monoclonal immunoglobulin deposition disease, and cast nephropathy. Less frequently reported is light chain proximal tubulopathy, a disease characterized by ?-restricted crystal deposits in the proximal tubule cytoplasm. Light chain proximal tubulopathy without crystal deposition is only loosely related to the typical light chain proximal tubulopathy, and little is known about this entity. A search was performed of the 10 081 native kidney biopsy samples processed by our laboratory over the past 2 years for cases that had light chain restriction limited to the proximal tubule cytoplasm. A total of 10 cases of light chain proximal tubulopathy without crystal deposition were found representing 3.1% of light chain-related diseases. Nine of these 10 showed ?-light chain restriction. Only three cases of light chain proximal tubulopathy with crystals were found accounting for 0.9% of light chain-related diseases. Two of these three were ? subtype. Plasma cell dyscrasia was unsuspected in seven of the 10 patients with light chain proximal tubulopathy without crystals at the time of renal biopsy. After the biopsy was reported, follow-up was available on 9/10 patients with 9/9 showing a plasma cell dyscrasia including 8/9 with multiple myeloma. We found that light chain proximal tubulopathy without crystal formation, despite being rarely described in the literature, is over three times more common than light chain proximal tubulopathy with crystal formation in our series. And given that it is often associated with previously unrecognized myeloma, it is a critically important diagnosis. PMID:21701535

Larsen, Christopher P; Bell, Jane M; Harris, Alexis A; Messias, Nidia C; Wang, Yihan H; Walker, Patrick D

2011-11-01

383

Proximal femoral replacement and allograft prosthesis composite in the treatment of periprosthetic fractures with significant proximal bone loss.  

PubMed

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. PMID:23109303

Rasouli, Mohammad R; Porat, Manny D; Hozack, William J; Parvizi, Javad

2012-11-01

384

Shellfish: proximate composition, minerals, fatty acids, and sterols.  

PubMed

Proximate composition, minerals, fatty acids, and sterols were determined for eight species of shellfish commonly marketed in the Northwest. Moisture and total lipid content varied with the size of the species, with more variation in mollusca than in crustacea; total lipid content ranged from 0.7% in sea scallops to 3.1% in blue mussels but only from 1.2% in Dungeness crab to 1.3% in pink shrimp. The mineral content was highly variable; the mineral content of Northwest samples tended to be lower than that reported in other studies. Generally, shellfish are good sources of zinc, and Pacific oysters, blue mussels, and Manila clams are also good sources of iron. Five fatty acids (16:0, 16:1, 18:1, 20:5n-3, and 22:6n-3) represented from 60% to 84% of the fatty acid content. Palmitic acid ranged from 13% to 32% of the total fatty acids. Long-chain n-3 polyunsaturated fatty acids were predominant (37.6% to 54.3%), with sea scallops containing more than 50%; n-6 polyunsaturated fatty acids ranged from 1.5% to 6.5%. In crustacea, cholesterol was the primary sterol, and brassicasterol was the only other measurable sterol. In all mollusca except California squid, cholesterol averaged 37 mg/100 gm and ranged from 23% to 39% of the total sterols. In squid, cholesterol, at 231 mg/100 gm, was the only measurable sterol. We conclude that shellfish vary widely in their nutrient content but, in general, are valuable additions to the diet. PMID:2335682

King, I; Childs, M T; Dorsett, C; Ostrander, J G; Monsen, E R

1990-05-01

385

Unusual proximal dislocation without fracture: a case report.  

PubMed

Carpal instability includes a broad spectrum of osseous and ligamentous injuries which have been subclassified into greater and lesser arc injuries, in addition to combinations of both (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The injuries typically occur from a fall on the outstretched hand with the wrist in ulnar deviation, hyperextension, and intercarpal supination (Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The force classically propagates from the radial to the ulnar side of the wrist resulting in a fracture (greater arc) or dislocation (lesser arc) pattern with the extent of the injury occurring in an orderly pattern depending upon the degree of hyperextension and the duration and magnitude of the force (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). Multiple variations occur, including transradial styloid fractures as well as fractures through carpal bones surrounding the lunate (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985; Kozin SH. J Am Acad Orthop Surg 6 (2): 114-20, 1998. Although carpal dislocations have been noted for many years, the mechanisms and classification have only been recently clarified. We report a case of a complex dislocation involving the entire proximal carpal row without an associated fracture. While this type of complex carpal dislocation has been previously described, to our knowledge, it has never been reported without a fracture of the forearm, wrist, or hand. PMID:24294171

Akinleye, Sheriff D; Makani, Amun; Dalinka, Murray K; Chang, Benjamin

2012-12-01

386

A High Throughput Scintillation Proximity Imaging Assay for Protein Methyltransferases  

PubMed Central

Protein methyltransferases (PMTs) orchestrate epigenetic modifications through post-translational methylation of various protein substrates including histones. Since dysregulation of this process is widely implicated in many cancers, it is of pertinent interest to screen inhibitors of PMTs, as they offer novel target-based opportunities to discover small molecules with potential chemotherapeutic use. We have thus developed an enzymatic screening strategy, which can be adapted to scintillation proximity imaging assay (SPIA) format, to identify these inhibitors. We took advantage of S-adenosyl-L-[3H-methyl]-methionine availability and monitored the enzymatically catalyzed [3H]-methyl addition on lysine residues of biotinylated peptide substrates. The radiolabeled peptides were subsequently captured by streptavidin coated SPA imaging PS beads. We applied this strategy to four PMTs: SET7/9, SET8, SETD2, and EuHMTase1, and optimized assay conditions to achieve Z? values ranging from 0.48 to 0.91. The robust performance of this SPIA for the four PMTs was validated in a pilot screen of approximately 7,000 compounds. We identified 80 cumulative hits across the four targets. NF279, a suramin analogue found to specifically inhibit SET7/9 and SETD2 with IC50 values of 1.9 and 1.1 ?M, respectively. Another identified compound, Merbromin, a topical antiseptic, was classified as a pan-active inhibitor of the four PMTs. These findings demonstrate that our proposed SPIA strategy is generic for multiple PMTs and can be successfully implemented to identify novel and specific inhibitors of PMTs. The specific PMT inhibitors may constitute a new class of anti-proliferative agents for potential therapeutic use. PMID:22256970

Ibanez, Glorymar; Shum, David; Blum, Gil; Bhinder, Bhavneet; Radu, Constantin; Antczak, Christophe; Luo, Minkui; Djaballah, Hakim

2013-01-01

387

Design and characterization of a close-proximity thermoacoustic sensor.  

PubMed

Although the radiation force balance is the gold standard for measuring ultrasound intensity, it cannot be used for real-time monitoring in certain settings, for example, bioreactors or in the clinic to measure ultrasound intensities during treatment. Foreseeing these needs, we propose a close-proximity thermoacoustic sensor. In this article, we describe the design, characterization, testing and implementation of such a sensor. We designed a 20-mm-diameter plexiglass sensor with a 2-mm-long absorber and tested it against low-intensity pulsed ultrasound generated at a 1.5-MHz frequency, 20% duty cycle, 1-kHz pulse repetition frequency and intensities between 30 and 120 mW/cm(2). The sensor captures the beam, converts the ultrasound power into heat and indirectly measures the spatial-average time-average ultrasound intensity (Isata) by dividing the calculated power by the beam cross section (or the nominal area of the transducers). A thin copper sheet was attached to the back face of the sensor with thermal paste to increase heat diffusivity 1000-fold, resulting in uniform temperature distribution across the back face. An embedded system design was implemented using an Atmel microcontroller programmed with a least-squares algorithm to fit measured temperature-versus-time data to a model describing the temperature rise averaged across the back side of the sensor in relation to the applied ultrasound intensity. After it was calibrated to the transducer being measured, the thermoacoustic sensor was able to measure ultrasound intensity with an average error of 5.46% compared with readings taken using a radiation force balance. PMID:23820248

Xing, Jida; Choi, Michael; Ang, Woon; Yu, Xiaojian; Chen, Jie

2013-09-01

388

An improved proximal tephrochronology for Redoubt Volcano, Alaska  

NASA Astrophysics Data System (ADS)

Sediment cores from lakes in volcanically active regions can be used to reconstruct the frequency of tephra-fall events. We studied sediment cores from two lakes within 25 km of the summit of Redoubt Volcano, western Cook Inlet, to develop a robust age model for the Holocene tephrochronology, and to assess the extent to which the tephrostratigraphies were correlative between the two nearby lakes. Visually distinct tephra layers were correlated among cores from Bear and Cub lakes, located within 17 km of each other, to construct a composite age model, which incorporates two Pu-activity profiles and 27 radiocarbon ages, and extends the record back to 11,540 cal a BP. The age model was used to interpolate the ages and quantify the uncertainties of ages for all tephras at least 1 mm thick. Between - 55 and 3850 a BP, 31 tephras were deposited in Bear Lake and 41 tephras in Cub Lake. Bear Lake contains an additional 38 tephras deposited between 11,540 and 3850 a BP. During the period of overlap, (- 55 to 3850 a BP), 24 tephras are of significantly different ages, including nine from Bear Lake and 17 from Cub Lake. The presence of these unique tephras indicates that ejecta plumes erupted from Redoubt Volcano can be highly directional, and that sediment cores from more than one lake are needed for a comprehensive reconstruction of tephra-fall events. Unlike distal lakes in south Alaska, where geomorphic and limnological factors dominate the quality of the tephrostratigraphic record, the variability in tephra-fall trajectory near a Redoubt Volcano appears to be a major control on the number of tephras contained in the sediment of proximal lakes.

Schiff, Caleb J.; Kaufman, Darrell S.; Wallace, Kristi L.; Ketterer, Michael E.

2010-06-01

389

T-cell receptor signaling induces proximal Runx1 transactivation via a calcineurin-NFAT pathway.  

PubMed

Runx1 transcription factor is a key player in the development and function of T cells. Runx1 transcripts consist of two closely related isoforms (proximal and distal Runx1) whose expressions are regulated by different promoters. Which Runx1 isoform is expressed appears to be tightly regulated. The regulatory mechanism for differential transcription is, however, not fully understood. In this study, we investigated the regulation of the proximal Runx1 promoter in T cells. We showed that proximal Runx1 was expressed at a low level in naïve T cells from C57BL/6 mice, but its expression was remarkably induced upon T-cell activation. In the promoter of proximal Runx1, a highly conserved region was identified which spans from -412 to the transcription start site and harbors a NFAT binding site. In a luciferase reporter assay, this region was found to be responsive to T-cell activation through Lck and calcineurin pathways. Mutagenesis studies and chromatin immunoprecipitation assay indicated that the NFAT site was essential for NFAT binding and transactivation of the proximal Runx1 promoter. Furthermore, TCR signaling-induced expression of proximal Runx1 was blocked by treatment of cells with cyclosporin A. Together, these results demonstrate that the calcineurin-NFAT pathway regulates proximal Runx1 transcription upon TCR stimulation. PMID:24310293

Wong, Won Fen; Looi, Chung Yeng; Kon, Shunsuke; Movahed, Elaheh; Funaki, Tomo; Chang, Li Yen; Satake, Masanobu; Kohu, Kazuyoshi

2014-03-01

390

Regulatory mechanism of cell pH in the renal proximal tubule of bullfrog nephron.  

PubMed

To examine the cellular mechanism of urinary acidification in detail, micropuncture studies were performed on the in situ bullfrog proximal tubule with nigericin-based pH microelectrodes. Pencil-type double-barreled antimony microelectrodes were also used for monitoring pHs of the tubular fluids. Luminal perfusion of 10(-3) M cyanide caused a biphasic change in cell pH (pHi): i.e., early acidification by 0.04 pH unit in 2 min and later alkalinization by 0.04. A profound depolarization of 30-35 mV was observed in the peritubular membrane potential (EM Peri), although the tubular fluid pH (pHTF) was elevated by 0.11 unit. Luminal substitution of 100 mM Na+ by Li+ acidified the cell by 0.06 pH unit with a depolarization of EM Peri by 8 mV and an alkalinization of pHTF by 0.10 unit. It is a fact that cellular acidification and luminal alkalinization are in good agreement with the depression of luminal H+ secretory mechanism. Perfusion of 10(-4) M SITS from the peritubular side caused a rise in pHi by 0.04 without appreciable changes in EM Peri in the short period application. Peritubular perfusion of 10(-4) M ouabain lowered the pHi by 0.07 with a resulting depolarization of EM Peri by 15.4 mV, meanwhile, the pHTF, while initially lowered by 0.07 unit, was elevated 4 min later by 0.12. Inhibitions of the peritubular ion transport mechanism caused some pH changes in the same direction, both in the cell interior and the tubular fluid. Further, from the ouabain experiment, it is inferred that some linkages, mediated by Na+ and H+(or HCO3-), would exist between the peritubular and luminal membranes. PMID:3001393

Matsumura, Y; Aoki, S; Fujimoto, M

1985-01-01

391

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

PubMed

Individuals within social groups often show consistent differences in behaviour across time and context. Such interindividual differences and the evolutionary challenge they present have recently generated considerable interest. Social insects provide some of the most familiar and spectacular examples of social groups with large interindividual differences. Investigating these within-group differences has a long research tradition, and behavioural variability among the workers of a colony is increasingly regarded as fundamental for a key feature of social insects: division of labour. The goal of this review is to illustrate what we know about both the proximate mechanisms underlying behavioural variability among the workers of a colony and its ultimate consequences; and to highlight the many open questions in this research field. We begin by reviewing the literature on mechanisms that potentially introduce, maintain, and adjust the behavioural differentiation among workers. We highlight the fact that so far, most studies have focused on behavioural variability based on genetic variability, provided by e.g. multiple mating of the queen, while other mechanisms that may be responsible for the behavioural differentiation among workers have been largely neglected. These include maturational, nutritional and environmental influences. We further discuss how feedback provided by the social environment and learning and experience of adult workers provides potent and little-explored sources of differentiation. In a second part, we address what is known about the potential benefits and costs of increased behavioural variability within the workers of a colony. We argue that all studies documenting a benefit of variability so far have done so by manipulating genetic variability, and that a direct test of the effect of behavioural variability on colony productivity has yet to be provided. We emphasize that the costs associated with interindividual variability have been largely overlooked, and that a better knowledge of the cost/benefit balance of behavioural variability is crucial for our understanding of the evolution of the mechanisms underlying the social organization of insect societies. We conclude by highlighting what we believe to be promising but little-explored avenues for future research on how within-colony variability has evolved and is maintained. We emphasize the need for comparative studies and point out that, so far, most studies on interindividual variability have focused on variability in individual response thresholds, while the significance of variability in other parameters of individual response, such as probability and intensity of the response, has been largely overlooked. We propose that these parameters have important consequences for the colony response. Much more research is needed to understand if and how interindividual variability is modulated in order to benefit division of labour, homeostasis and ultimately colony fitness in social insects. PMID:24341677

Jeanson, Raphaël; Weidenmüller, Anja

2014-08-01

392

Role of caveolin 1 in AT1a receptor-mediated uptake of angiotensin II in the proximal tubule of the kidney.  

PubMed

Caveolin 1 (CAV-1) functions not only as a constitutive scaffolding protein of caveolae but also as a vesicular transporter and signaling regulator. In the present study, we tested the hypothesis that CAV-1 knockout (CAV-1 KO) inhibits ANG II type 1 [AT1 (AT1a)] receptor-mediated uptake of ANG II in the proximal tubule and attenuates blood pressure responses in ANG II-induced hypertension. To determine the role of CAV-1 in mediating the uptake of FITC-labeled ANG II, wild-type (WT) mouse proximal convoluted tubule cells were transfected with CAV-1 small interfering (si)RNA for 48 h before AT1 receptor-mediated uptake of FITC-labeled ANG II was studied. CAV-1 siRNA knocked down CAV-1 expression by >90% (P < 0.01) and inhibited FITC-labeled ANG II uptake by >50% (P < 0.01). Moreover, CAV-1 siRNA attenuated ANG II-induced activation of MAPK ERK1/2 and Na(+)/H(+) exchanger 3 expression, respectively (P < 0.01). To determine whether CAV-1 regulates ANG II uptake in the proximal tubule, Alexa 488-labeled ANG II was infused into anesthetized WT and CAV-1 KO mice for 60 min (20 ng/min iv). Imaging analysis revealed that Alexa 488-labeled ANG II uptake was decreased by >50% in CAV-1 KO mice (P < 0.01). Furthermore, Val(5)-ANG II was infused into WT and CAV-1 KO mice for 2 wk (1.5 mg·kg(-1)·day(-1) ip). Basal systolic pressure was higher, whereas blood pressure and renal excretory and signaling responses to ANG II were attenuated, in CAV-1 KO mice (P < 0.01). We concluded that CAV-1 plays an important role in AT1 receptor-mediated uptake of ANG II in the proximal tubule and modulates blood pressure and renal responses to ANG II. PMID:25164083

Li, Xiao C; Gu, Victor; Miguel-Qin, Elise; Zhuo, Jia L

2014-10-15

393

Proximal outcomes matter: a multilevel examination of the processes by which coordinating councils produce change.  

PubMed

Communities are engaged in efforts to create a coordinated response to intimate partner violence. Though coordinating councils are commonly employed vehicles for such efforts, research provides only equivocal support regarding their effectiveness. These mixed findings may reflect methodological and conceptual challenges. Specifically, there is an over-reliance on conceptualizing council effectiveness in terms of distal outcomes (e.g., behavior change), rather than the intermediary processes by which councils affect change. A direct assessment of councils' proximal outcomes may highlight change mechanisms. To that end, this study investigates the extent to which councils impact proximal outcomes and examines the processes through which proximal outcomes are interrelated and linked to distal community change. Study findings suggest that perceived proximal outcomes do significantly predict variability in perceived distal community change across councils. Specifically, promotion of social capital and institutionalized change predict achievement of distal community change, and promotion of social capital also predicts achievement of institutionalized change. PMID:21052823

Javdani, Shabnam; Allen, Nicole E

2011-03-01

394

14 CFR 91.143 - Flight limitation in the proximity of space flight operations.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143...GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Flight Rules General §...

2010-01-01

395

14 CFR 91.143 - Flight limitation in the proximity of space flight operations.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Flight limitation in the proximity of space flight operations. 91.143 Section 91.143...GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Flight Rules General §...

2012-01-01

396

Mutations of the NOG gene in individuals with proximal symphalangism and multiple synostosis syndrome.  

PubMed

Proximal symphalangism is an autosomal-dominant disorder with ankylosis of the proximal interphalangeal joints, carpal and tarsal bone fusion, and conductive deafness. These symptoms are shared by another disorder of joint morphogenesis, multiple synostoses syndrome. Recently, it was reported that both disorders were caused by heterozygous mutations of the human noggin gene (NOG). To date, seven mutations of NOG have been identified from unrelated families affected with joint morphogenesis. To characterize the molecular lesions of proximal symphalangism, we performed analyses of NOG in three Japanese individuals with proximal symphalangism. We found three novel mutations: g.551G>A (C184Y) in a sporadic case of symphalangism, g.386T>A (L129X) in a familial case of symphalangism, and a g.58delC (frameshift) in a family with multiple synostosis syndrome. Characteristic genotype-phenotype correlations have not been recognized from the mutations in the NOG gene. PMID:11846737

Takahashi, T; Takahashi, I; Komatsu, M; Sawaishi, Y; Higashi, K; Nishimura, G; Saito, H; Takada, G

2001-12-01

397

Edeline et al. Eel continental dispersal Proximate and ultimate control of eel continental  

E-print Network

occurs on the slope of the continental shelf (SchEdeline et al. Eel continental dispersal Chapter 18 Proximate and ultimate control of eel continental dispersal Eric Edeline1* , Sylvie Dufour2 , Pierre Elie3 1 University of Oslo, Department

Paris-Sud XI, Université de

398

Using Risk for Advanced Proximal Colonic Neoplasia to Tailor Endoscopic Screening for Colorectal Cancer  

Cancer.gov

USING RISK FOR ADVANCED PROXIMAL COLONIC NEOPLASIA TO TAILOR ENDOSCOPIC SCREENING FOR COLORECTAL CANCER Thomas F. Imperiale, MD, Ching Y Lin, BS, Indiana University School of Medicine; David R. Wagner, MS, James D. Rogge, MD, Indianapolis Gastroenterology

399

Management bone loss of the proximal femur in revision hip arthroplasty: Update on reconstructive options  

PubMed Central

The number of revision total hip arthroplasties is expected to rise as the indications for arthroplasty will expand due to the aging population. The prevalence of extensive proximal femoral bone loss is expected to increase subsequently. The etiology of bone loss from the proximal femur after total hip arthroplasty is multifactorial. Stress shielding, massive osteolysis, extensive loosening and history of multiple surgeries consist the most common etiologies. Reconstruction of extensive bone loss of the proximal femur during a revision hip arthroplasty is a major challenge for even the most experienced orthopaedic surgeon. The amount of femoral bone loss and the bone quality of the remaining metaphyseal and diaphyseal bone dictate the selection of appropriate reconstructive option. These include the use of impaction allografting, distal press-fit fixation, allograft-prosthesis composites and tumor megaprostheses. This review article is a concise review of the current literature and provides an algorithmic approach for reconstruction of different types of proximal femoral bone defects.

Sakellariou, Vasileios I; Babis, George C

2014-01-01

400

Foreign direct investment, intra-organizational proximity, and technological capability : the case of China's automobile industry  

E-print Network

This dissertation consists of three self-contained essays, each of which examines part of the causal link among inward/outward foreign direct investment (FDI), intra-organizational proximity, and in-house technology ...

Nam, Kyung-min

2010-01-01

401

Climate change impacts on mountain glaciers and permafrost Due to their proximity to melting conditions under  

E-print Network

Editorial Climate change impacts on mountain glaciers and permafrost Due to their proximity to melting conditions under terrestrial conditions, mountain glaciers and permafrost are particularly). Mountain and lowland permafrost are similarly sensitive to climate changes because of their strong

Raup, Bruce H.

402

A Proximity Algorithm Accelerated by Gauss-Seidel Iterations for L1/TV Denoising Models  

E-print Network

A Proximity Algorithm Accelerated by Gauss-Seidel Iterations for L1/TV Denoising Models Qia Li be accelerated through the use of the component-wise Gauss-Seidel iteration so that the CPU-time consumed is sig

Soatto, Stefano

403

Shox2 function couples neural, muscular and skeletal development in the proximal forelimb  

E-print Network

to the human SHOX gene, deficiencies of which cause the short stature in Turner, Langer and Léri­Weill syndromes. In order to understand in more detail the development of the proximal limb, we searched for Shox2

Cobb, John

404

Effect of nanofiber proximity on the mechanical behavior of high volume fraction aligned carbon nanotube arrays  

E-print Network

The effect of nanofiber proximity on the mechanical behavior of nanofiber arrays with volume fractions (V f) from 1% to 20% was quantified via nanoindentation of an aligned carbon nanotube (A-CNT) array. The experimental ...

Cebeci, Hülya

405

Proximity-dependent Pollen Performance in Silene vulgaris ME LANIE GLAETTLI1,  

E-print Network

Proximity-dependent Pollen Performance in Silene vulgaris ME´ LANIE GLAETTLI1, *, LUCA PESCATORE2 structure was investigated in a patchily distributed population of gynodioecious Silene vulgaris: Population structure, microsatellites, pollen performance, gynodioecy, Silene vulgaris. INTRODUCTION

Alvarez, Nadir

406

Regulation of proximal tubule vacuolar H(+)-ATPase by PKA and AMP-activated protein kinase.  

PubMed

The vacuolar H(+)-ATPase (V-ATPase) mediates ATP-driven H(+) transport across membranes. This pump is present at the apical membrane of kidney proximal tubule cells and intercalated cells. Defects in the V-ATPase and in proximal tubule function can cause renal tubular acidosis. We examined the role of protein kinase A (PKA) and AMP-activated protein kinase (AMPK) in the regulation of the V-ATPase in the proximal tubule as these two kinases coregulate the V-ATPase in the collecting duct. As the proximal tubule V-ATPases have different subunit compositions from other nephron segments, we postulated that V-ATPase regulation in the proximal tubule could differ from other kidney tubule segments. Immunofluorescence labeling of rat ex vivo kidney slices revealed that the V-ATPase was present in the proximal tubule both at the apical pole, colocalizing with the brush-border marker wheat germ agglutinin, and in the cytosol when slices were incubated in buffer alone. When slices were incubated with a cAMP analog and a phosphodiesterase inhibitor, the V-ATPase accumulated at the apical pole of S3 segment cells. These PKA activators also increased V-ATPase apical membrane expression as well as the rate of V-ATPase-dependent extracellular acidification in S3 cell monolayers relative to untreated cells. However, the AMPK activator AICAR decreased PKA-induced V-ATPase apical accumulation in proximal tubules of kidney slices and decreased V-ATPase activity in S3 cell monolayers. Our results suggest that in proximal tubule the V-ATPase subcellular localization and activity are acutely coregulated via PKA downstream of hormonal signals and via AMPK downstream of metabolic stress. PMID:24553431

Al-bataineh, Mohammad M; Gong, Fan; Marciszyn, Allison L; Myerburg, Michael M; Pastor-Soler, Núria M

2014-05-01

407

Fluid secretion in isolated proximal straight renal tubules. Effect of human uremic serum.  

PubMed

We have examined the effect of normal and uremic human sera on the transtubular flow of fluid in isolated perfused segments of rabbit proximal convoluted and straight renal tubules. Proximal convoluted and straight tubules absorbed fluid from the lumen when the external bath was normal rabbit serum. Normal human sera in the bath depressed net fluid absorption in both tubular segments, but more importantly, uremic human serum caused proximal straight tubules to secrete fluid into the lumen. Fluid secretion was also demonstrated indirectly by observing in nonperfused proximal straight, but not proximal convoluted tubules, that the normally collapsed lumens opened widely in uremic serum. Nonperfused proximal straight tubules developed expanded lumens even after a 25-fold dilution of human uremic serum with normal rabbit serum, whereas lumen expansion occurred only in undiluted normal human serum, on the average. Serum from acutely uremic rabbits possessed secretory activity but normal rabbit serum did not. The secretory effect of uremic sera in proximal straight tubules was inhibited by cooling and ouabain and probenecid. The secretory activity of uremic sera was removed by dialysis, but not by freezing or boiling. Para-aminohippurate and benzoate caused fluid secretion in proximal straight tubules but urea, creatinine, guanidinosuccinate, and urate did not. On the basis of these results, we suggest that the secretory factor in serum may be a substance or group of substances possibly related to the hippurate class of organic molecules that are accumulated to relatively high concentrations in renal failure. The secretory material in the serum of uremic patients may significantly influence the transport of salt and water in relatively intact residual nephrons. PMID:4738063

Grantham, J J; Irwin, R L; Qualizza, P B; Tucker, D R; Whittier, F C

1973-10-01

408

Allograft-Prosthetic Composite in the Proximal Tibia After Bone Tumor Resection  

Microsoft Academic Search

We consider an allograft-prosthesis composite in the proximal tibia one of the better reconstructive options in this site\\u000a because it combines the mechanical stability of a prosthesis with the biologic reconstruction of the extensor mechanism. We\\u000a retrospectively reviewed 62 patients who had proximal tibia reconstructions with allograft-prosthesis composites to ascertain\\u000a the complications and functional outcomes. By combining an allograft with

Davide Donati; Marco Colangeli; Simone Colangeli; Claudia Di Bella; Mario Mercuri

2008-01-01

409

Proximal Tubular Injury Attenuates Outer Medullary Hypoxic Damage: Studies in Perfused Rat Kidneys  

Microsoft Academic Search

The straight segment (S3) of the proximal tubule is predominantly damaged during renal ischemia-reflow, whereas medullary thick ascending limbs (mTALs) are principally affected in other models of hypoxic acute tubular necrosis (ATN). Since the latter injury pattern largely depends on the extent of reabsorptive activity during hypoxic stress, we hypothesized that proximal tubular damage might attenuate downstream mTAL injury by

Samuel N. Heyman; Ahuva Shina; Mayer Brezis; Seymour Rosen

2002-01-01

410

Magnetic response of odd-frequency s-wave Cooper pairs in a superfluid proximity system.  

PubMed

We investigate the magnetic response of a dirty-normal-Fermi-liquid-spin-triplet-superfluid proximity system consisting of liquid 3He and aerogel. In contrast to bulk superfluids, Pauli spin susceptibility in the proximity system exceeds its normal-state value locally around the interface. This enhanced Pauli paramagnetism originates from odd-frequency s-wave pairing arising due to spatial inhomogeneity. A characteristic observable signature of the paramagnetic effect can be found in the spin susceptibility temperature dependence. PMID:23679740

Higashitani, S; Takeuchi, H; Matsuo, S; Nagato, Y; Nagai, K

2013-04-26

411

Production of angiotensinogen and renin-like activity by rabbit proximal tubular cells in culture  

Microsoft Academic Search

Production of angiotensinogen and renin-like activity by rabbit proximal tubular cells in culture. Recent studies suggest the presence of local angiotensin generating system in the kidney. By using in situ hybridization technique, mRNA for angiotensinogen has been shown to be present in the proximal tubule. In the present study, we have attempted to examine the production of angiotensinogen and renin-like

Norimoto Yanagawa; Anthony W Capparelli; Ok D Jo; Ann Friedal; Jack D Barrett; Peter Eggena

1991-01-01

412

Cultivating competence, self-efficacy, and intrinsic interest through proximal self-motivation  

Microsoft Academic Search

Tested the hypothesis that self-motivation through proximal goal setting serves as an effective mechanism for cultivating competencies, self-percepts of efficacy, and intrinsic interest. 40 children (7.3–10.1 yrs of age) who exhibited gross deficits and disinterest in mathematical tasks pursued a program of self-directed learning under conditions involving either proximal subgoals, distal goals, or no goals. Results of the multifaceted assessment

Albert Bandura; Dale H. Schunk

1981-01-01

413

A new technique of endoprosthetic replacement for osteosarcoma of proximal femur with intra-articular extension  

PubMed Central

INTRODUCTION Osteosarcoma is the most common primary malignant tumour of bone and commonly involved sites are the distal femur, proximal tibia, and humerus. Osteosarcoma of proximal femur usually arises at the metaphysis and articular cartilage acts as a relative barrier to tumour spread, with extension into the hip joint being extremely rare. PRESENTATION OF CASE A previously fit and well sixteen-year-old male presented with a 2 month history of right hip pain and a limp. Plain radiographs and magnetic resonance imaging (MRI) showed an expansile lesion in the right femoral neck, extending 16 cm distally from the proximal femoral articular surface through the intertrochanteric region into the upper right femoral shaft. There was also clear evidence of intra-articular extension into the acetabulum. DISCUSSION Endoprosthetic replacement following resection is a good treatment option for proximal femoral tumours due to the low complication rate and achievement of good postoperative function. However, treatment of a proximal femoral lesion with intra-articular involvement by prosthetic reconstruction is challenging. We report a patient who presented with osteosarcoma of the proximal femur extending into the hip joint and describe the technique of en-bloc extra-articular resection of the acetabulum and proximal femur with reconstruction using a custom made prosthesis. CONCLUSION We conclude that extra-articular resection and endoprosthetic reconstruction using a coned hemi-pelvic implant with fluted stem and a modular femoral implant is a useful treatment option in the management of a proximal femoral lesion involving the hip-joint. It allows adequate tumour clearance and stable reconstruction for rapid post-operative recovery with early mobilisation. PMID:23147775

Oragui, E.; Nannaparaju, M.; Sri-Ram, K.; Khan, W.; Hashemi-Nejad, A.; Skinner, J.

2012-01-01

414

A proximity algorithm accelerated by Gauss–Seidel iterations for L1\\/TV denoising models  

Microsoft Academic Search

Our goal in this paper is to improve the computational performance of the proximity algorithms for the L1\\/TV denoising model. This leads us to a new characterization of all solutions to the L1\\/TV model via fixed-point equations expressed in terms of the proximity operators. Based upon this observation we develop an algorithm for solving the model and establish its convergence.

Qia Li; Charles A Micchelli; Lixin Shen; Yuesheng Xu

2012-01-01

415

The impact of proximity to cell phone towers on residential property values  

Microsoft Academic Search

Purpose – This paper aims to determine if proximity to cell phone towers influences house prices with a focus on isolating the impact of tower aesthetics on nearby property values. Design\\/methodology\\/approach – Sales transaction data from the Auckland Region during 2005-2007 were analysed using a series of hedonic models testing various proximity specifications across two populations of cell towers: residential-only

Olga Filippova; Michael Rehm

2011-01-01

416

Acute phosphate depletion and in vitro rat proximal tubule injury: Protection by glycine and acidosis  

Microsoft Academic Search

Acute phosphate depletion and in vitro rat proximal tubule injury: Protection by glycine and acidosis.The effects of phosphate (PO4) removal from Krebs Henseleit buffer on freshly isolated rat proximal tubules (rPT) were assessed by measuring Ca2+ uptake (nmol\\/mg protein), cellular adenosine triphosphate (ATP) (nmol\\/mg), tissue K+ content (nmol\\/mg) and lactate dehydrogenase (LDH) as an index of cell integrity. Ca2+ uptake

Antonio R P Almeida; Jack F M Wetzels; Derek Bunnachak; Thomas J Burke; Cidio Chaimovitz; William S Hammond; Robert W Schrier

1992-01-01

417

Red receptors dominate the proximal tier of the retina in the butterfly Papilio xuthus  

Microsoft Academic Search

1.The ommatidia of the butterfly Papilio have a fused and tiered rhabdom. The distal tier of the rhabdom is made up of four distal photoreceptors (R1–4), whereas the proximal tier is made up of four proximal (R5–8) and one basal photoreceptor cell (R9).2.We first confirmed by light microscopy that the ommatidia of Papilio are not twisted, i.e. have the same

K. Arikawa; H. Uchiyama

1996-01-01

418

Does Geographic Proximity Matter? Evidence from Clustered and Non-clustered Aeronautic Firms in Germany  

Microsoft Academic Search

L UBLINSKI A. E. (2003) Does geographic proximity matter? Evidence from clustered and non-clustered aeronautic firms in Germany, Reg. Studies 37 , 453-467. This paper analyses what types of inter-firm linkages are stronger between geographically proximate firms compared to distant firms. It compares survey results of clustered and dispersed firms in the German aeronautic (supplying) industry. Results show that geographic

Alf Erko Lublinski

2003-01-01

419

Early Surgical Repair of Acute Complete Rupture of the Proximal Hamstring Tendons  

PubMed Central

Hamstring injuries are common forms of muscle strains in athletes but a complete rupture of a proximal hamstring origin is rare. Often there is a considerable delay in diagnosis and stringent treatment because of its rarity, difficulty in clinical diagnosis, and initial attempts of conservative care. We report two cases of acute complete rupture of the proximal hamstring tendons treated with early surgical repair. The diagnosis and treatment of this unusual injury are discussed. PMID:21909474

Kwak, Ho Yoon; Choi, Yun Sun; Jang, Mun Suk

2011-01-01

420

Reduction in proximal femoral strength due to long-duration spaceflight  

Microsoft Academic Search

Loss of bone mass is a well-known medical complication of long-duration spaceflight. However, we do not know how changes in bone density and geometry ultimately combine to affect the strength of the proximal femur as a whole. The goal of this study was to quantify the changes in proximal femoral strength that result from long-duration spaceflight. Pre-and post-flight CT scan-based

J. H. Keyak; A. K. Koyama; A. LeBlanc; Y. Lu; T. F. Lang

2009-01-01

421

Eddy-Current Type Proximity Sensor With Closed Magnetic Circuit Geometry  

Microsoft Academic Search

The eddy-current type proximity sensor is a noncontact type sensing device to detect the approach of a conductor by increase of coil resistance due to eddy-current loss. This paper proposes to add the cap-shaped magnetic flux shield at the top of the ferrite core for the actual sensor. In conventional proximity sensors, main magnetic flux path passes through the air

Koichi Koibuchi; Koichiro Sawa; Takashi Honma; Takumi Hayashi; Kuniyoshi Ueda; Hiroshi Sasaki

2007-01-01

422

Proximal tibia medial open-wedge osteotomy using plates with wedges: early results in 58 cases  

Microsoft Academic Search

We evaluated in this study indications, surgical technique, and results of wedge plates for fixation in proximal tibia medial opening wedge osteotomy. Fifty-eight knees in 56 consecutive patients (9 men, 47 women; mean age 52 years; ranging between 36 and 66 years) with medial compartment osteoarthrosis were treated with proximal tibia medial open-wedge osteotomy. For fixation, plates which were designed by the

Irfan Esenkaya; Nurzat Elmali

2006-01-01

423

Cadmium chloride inhibits lactate gluconeogenesis in isolated human renal proximal tubules: a cellular metabolomic approach with 13C-NMR.  

PubMed

As part of a study on cadmium nephrotoxicity, we studied the effect of cadmium chloride (CdCl2) in isolated human renal proximal tubules metabolizing the physiological substrate lactate. Dose-effect experiments showed that 10-500 ?M CdCl2 reduced lactate removal, glucose production and the cellular levels of ATP, coenzyme A, acetyl-coenzyme A and of reduced glutathione in a dose-dependent manner. After incubation with 5 mM L: -[1-(13)C]-, or L: -[2-(13)C]-, or L: -[3-(13)C] lactate or 5 mM L: -lactate plus 25 mM NaH(13)CO3 as substrates, substrate utilization and product formation were measured by both enzymatic and carbon 13 NMR methods. Combination of enzymatic and NMR measurements with a mathematical model of lactate metabolism previously validated showed that 100 ?M CdCl2 caused an inhibition of flux through lactate dehydrogenase and alanine aminotransferase and through the entire gluconeogenic pathway; fluxes were diminished by 19% (lactate dehydrogenase), 28% (alanine aminotransferase), 28% (pyruvate carboxylase), 42% (phosphoenolpyruvate carboxykinase), and 52% (glucose-6-phosphatase). Such effects occurred without altering the oxidation of the lactate carbons or fluxes through enzymes of the tricarboxylic acid cycle despite a large fall of the cellular ATP level, a marker of the energy status and of the viability of the renal cells. These results that were observed at clinically relevant tissue concentrations of cadmium provide a biochemical basis for a better understanding of the cellular mechanism of cadmium-induced renal proximal tubulopathy in humans chronically exposed to cadmium. PMID:21153630

Faiz, Hassan; Conjard-Duplany, Agnès; Boghossian, Michelle; Martin, Guy; Baverel, Gabriel; Ferrier, Bernard

2011-09-01

424

Proximal Point Algorithm with Schur Decomposition on the Cone of Symmetric Semidefinite Positive Matrices ?  

E-print Network

In this work, we propose a proximal algorithm for unconstrained optimization on the cone of symmetric semidefinite positive matrices. It appears to be the first in the proximal class on the set of methods that convert a Symmetric Definite Positive Optimization in Nonlinear Optimization. It replaces the main iteration of the conceptual proximal point algorithm by a sequence of nonlinear programming problems on the cone of diagonal definite positive matrices that has the structure of the positive orthant of the Euclidian vector space. We are motivated by results of the classical proximal algorithm extended to Riemannian manifolds with non positive sectional curvature. An important example of such manifold is the space of symmetric definite positive matrices, where the metrics is given by the Hessian of the standard barrier function ?ln det(X). Then, observing the obvious fact that proximal algorithms do not depend on the geodesics, we apply those ideas to develop a proximal point algorithm for convex functions in this Riemannian metric.

Ronaldo Gregório; Paulo Roberto Oliveira

2008-01-01

425

Proximity to Sports Facilities and Sports Participation for Adolescents in Germany  

PubMed Central

Objectives To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany. Methods A sample of 1,768 adolescents aged 11–17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities. Results The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively. Conclusions Improved proximity to gyms is likely to be more important for female adolescents living in rural areas. PMID:24675689

Reimers, Anne K.; Wagner, Matthias; Alvanides, Seraphim; Steinmayr, Andreas; Reiner, Miriam; Schmidt, Steffen; Woll, Alexander

2014-01-01

426

The Effect of Geographical Proximity on Scientific Cooperation among Chinese Cities from 1990 to 2010  

PubMed Central

Background The relations between geographical proximity and spatial distance constitute a popular topic of concern. Thus, how geographical proximity affects scientific cooperation, and whether geographically proximate scientific cooperation activities in fact exhibit geographic scale features should be investigated. Methodology Selected statistics from the ISI database on cooperatively authored papers, the authors of which resided in 60 typical cites in China, and which were published in the years 1990, 1995, 2000, 2005, and 2010, were used to establish matrices of geographic distance and cooperation levels between cities. By constructing a distance-cooperation model, the degree of scientific cooperation based on spatial distance was calculated. The relationship between geographical proximity and scientific cooperation, as well as changes in that relationship, was explored using the fitting function. Result (1) Instead of declining, the role of geographical proximity in inter-city scientific cooperation has increased gradually but significantly with the popularization of telecommunication technologies; (2) the relationship between geographical proximity and scientific cooperation has not followed a perfect declining curve, and at certain spatial scales, the distance-decay regularity does not work; (3) the Chinese scientific cooperation network gathers around different regional center cities, showing a trend towards a regional network; within this cooperation network the amount of inter-city cooperation occurring at close range increased greatly. Conclusion The relationship between inter-city geographical distance and scientific cooperation has been enhanced and strengthened over time. PMID:25365449

Ma, Haitao; Fang, Chuanglin; Pang, Bo; Li, Guangdong

2014-01-01

427

Responses of proximal tubular cells to injury in congenital renal disease: fight or flight.  

PubMed

Most chronic kidney disease in children results from congenital or inherited disorders, which can be studied in mouse models. Following 2 weeks of unilateral ureteral obstruction (UUO) in the adult mouse, nephron loss is due to proximal tubular mitochondrial injury and cell death. In neonatal mice, proximal tubular cell death is delayed beyond 2 weeks of complete UUO, and release of partial UUO allows remodeling of remaining nephrons. Progressive cyst expansion develops in polycystic kidney disease (PKD), a common inherited renal disorder. The polycystic kidney and fibrosis (pcy)-mutant mouse (which develops late-onset PKD) develops thinning of the glomerulotubular junction in parallel with growth of cysts in adulthood. Renal insufficiency in nephropathic cystinosis, a rare inherited renal disorder, results from progressive tubular cystine accumulation. In the Ctns knockout mouse (a model of cystinosis), proximal tubular cells become flattened, with loss of mitochondria and thickening of tubular basement membrane. In each model, persistent obstructive or metabolic stress leads ultimately to the formation of atubular glomeruli. The initial "fight" response (proximal tubular survival) switches to a "flight" response (proximal tubular cell death) with ongoing oxidative injury and mitochondrial damage. Therapies should be directed at reducing proximal tubular mitochondrial oxidative injury to enhance repair and regeneration. PMID:23949631

Chevalier, Robert L; Forbes, Michael S; Galarreta, Carolina I; Thornhill, Barbara A

2014-04-01

428

The role of proximity caps during the annealing of UV-ozone oxidized GaAs  

SciTech Connect

This study provides a deeper insight into the chemistry and physics of the common engineering practice of using a proximity cap, while annealing compound semiconductors such as GaAs. We have studied the cases of a GaAs proximity cap, a Si proximity cap, and no proximity cap. Using x-ray photoelectron spectroscopy, it has been found that annealing increases the gallium to arsenic ratio in the oxide layer in all cases. During the annealing of UV-ozone oxidized GaAs, it has been observed that GaAs proximity caps also serve as a sacrificial layer to accelerate the desorption of oxide species. In all cases surface deterioration due to pit formation has been observed, and the depth of pits is found to depend on the effective role played by the capping material. Energy dispersive x-ray analysis provides additional evidence that pits mainly consist of elemental As and gallium oxide, with most of the elemental As situated at the pit-substrate interface. Deposition of a thin layer of gold and subsequent annealing to 500 deg. C for 300 s under different capping conditions shows the use of a proximate cap to be practically insignificant in annealing Au deposited films.

Ghosh, S. C.; Biesinger, M. C.; LaPierre, R. R.; Kruse, P. [Center for Emerging Device Technologies, Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Surface Science Western, Room G-1, Western Science Center, University of Western Ontario, London, Ontario N6A 5B7 (Canada); Center for Emerging Device Technologies, Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada) and Center for Emerging Device Technologies, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada)

2007-06-01

429

FXYD Proteins Stabilize Na,K-ATPase  

PubMed Central

FXYD proteins are a family of seven small regulatory proteins, expressed in a tissue-specific manner, that associate with Na,K-ATPase as subsidiary subunits and modulate kinetic properties. This study describes an additional property of FXYD proteins as stabilizers of Na,K-ATPase. FXYD1 (phospholemman), FXYD2 (? subunit), and FXYD4 (CHIF) have been expressed in Escherichia coli and purified. These FXYD proteins associate spontaneously in vitro with detergent-soluble purified recombinant human Na,K-ATPase (?1?1) to form ?1?1FXYD complexes. Compared with the control (?1?1), all three FXYD proteins strongly protect Na,K-ATPase activity against inactivation by heating or excess detergent (C12E8), with effectiveness FXYD1 > FXYD2 ? FXYD4. Heating also inactivates E1 ? E2 conformational changes and cation occlusion, and FXYD1 protects strongly. Incubation of ?1?1 or ?1?1FXYD complexes with guanidinium chloride (up to 6 m) causes protein unfolding, detected by changes in protein fluorescence, but FXYD proteins do not protect. Thus, general protein denaturation is not the cause of thermally mediated or detergent-mediated inactivation. By contrast, the experiments show that displacement of specifically bound phosphatidylserine is the primary cause of thermally mediated or detergent-mediated inactivation, and FXYD proteins stabilize phosphatidylserine-Na,K-ATPase interactions. Phosphatidylserine probably binds near trans-membrane segments M9 of the ? subunit and the FXYD protein, which are in proximity. FXYD1, FXYD2, and FXYD4 co-expressed in HeLa cells with rat ?1 protect strongly against thermal inactivation. Stabilization of Na,K-ATPase by three FXYD proteins in a mammalian cell membrane, as well the purified recombinant Na,K-ATPase, suggests that stabilization is a general property of FXYD proteins, consistent with a significant biological function. PMID:21228272

Mishra, Neeraj Kumar; Peleg, Yoav; Cirri, Erica; Belogus, Talya; Lifshitz, Yael; Voelker, Dennis R.; Apell, Hans-Juergen; Garty, Haim; Karlish, Steven J. D.

2011-01-01

430

The Mechanical Benefit of Medial Support Screws in Locking Plating of Proximal Humerus Fractures  

PubMed Central

Background The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures. Methods Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. Results Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P?0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. Conclusions Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure. PMID:25084520

Liu, Yanjie; Pan, Yao; Zhang, Wei; Zhang, Changqing; Zeng, Bingfang; Chen, Yunfeng

2014-01-01

431

Effects of proximity and activity on visual and auditory monitoring in wild Japanese macaques.  

PubMed

Group-living primates monitor group members to maintain the spatial cohesiveness of the group. We examined the possibility that visual scanning (turning the head for more than 3 sec) and contact calls (coo calls) function as visual and auditory monitoring behaviors to avoid separation from group members in wild Japanese macaques. The rate of visual scanning increased as proximity to group members decreased and as mobile activities (foraging and moving) increased, compared with immobile activities (resting and grooming). However, the rate of contact calls varied differently with proximity and activities. During resting and moving, the rate of contact calls increased as proximity decreased. In contrast, the rate increased with closer proximity during feeding. Visual scanning during all activities and contact calls during resting and moving increased when the group members were likely to spread over a larger area, suggesting that these behaviors functioned as monitoring of group members to avoid separation from the group. Contact calls also increased when the group members stayed in close proximity during foraging, suggesting that this behavior was also associated with competitive situations. Contact calls may also function to ease tension or maintain distance to avoid conflict in competitive situations. PMID:21344462

Suzuki, Mariko; Sugiura, Hideki

2011-07-01

432

Pinning technique for shoulder fractures in adolescents: computer modelling of percutaneous pinning of proximal humeral fractures  

PubMed Central

Background In the technique of percuatenous pinning of proximal humerus fractures, the appropriate entry site and trajectory of pins is unknown, especially in the adolescent population. We sought to determine the ideal entry site and trajectory of pins. Methods We used magnetic resonance images of nonfractured shoulders in conjunction with radiographs of shoulder fractures that were treated with closed reduction and pinning to construct 3-dimensional computer-generated models. We used engineering software to determine the ideal location of pins. We also conducted a literature review. Results The nonfractured adolescent shoulder has an articular surface diameter of 41.3 mm, articular surface thickness of 17.4 mm and neck shaft angle of 36°. Although adolescents and adults have relatively similar shoulder skeletal anatomy, they suffer different types of fractures. In our study, 14 of 16 adolescents suffered Salter–Harris type II fractures. The ideal location for the lateral 2 pins in an anatomically reduced shoulder fracture is 4.4 cm and 8.0 cm from the proximal part of the humeral head directed at 21.2° in the coronal plane relative to the humeral shaft. Conclusion Operative management of proximal humerus fractures in adolescents requires knowledge distinct from that required for adult patients. This is the first study to examine the anatomy of the nonfractured proximal humerus in adolescents. This is also the first study to attempt to model the positioning of percutaneous proximal humerus pins. PMID:20011155

Mehin, Ramin; Mehin, Afshin; Wickham, David; Letts, Merv

2009-01-01

433

Increased mitochondrial activity in renal proximal tubule cells from young spontaneously hypertensive rats  

PubMed Central

Renal proximal tubule cells from spontaneously hypertensive rats (SHR), compared with normotensive Wistar-Kyoto rats (WKY), have increased oxidative stress. The contribution of mitochondrial oxidative phosphorylation to the subsequent hypertensive phenotype remains unclear. We found that renal proximal tubule cells from SHR, relative to WKY, had significantly higher basal oxygen consumption rates, ATP synthesis-linked oxygen consumption rates, and maximum and reserve respiration. These bioenergetic parameters indicated increased mitochondrial function in renal proximal tubule cells from SHR compared with WKY. Pyruvate dehydrogenase complex activity was consistently higher in both renal proximal tubule cells and cortical homogenates from SHR than WKY. Treatment for 6 days with dichloroacetate, an inhibitor of pyruvate dehydrogenase kinase, significantly increased renal pyruvate dehydrogenase complex activity and systolic blood pressure in 3-week old WKY and SHR. Therefore, mitochondrial oxidative phosphorylation is higher in renal proximal tubule cells from SHR compared with WKY. Thus the pyruvate dehydrogenase complex is a determinant of increased mitochondrial metabolism that could be a causal contributor to the hypertension in SHR. PMID:24132210

Lee, Hewang; Abe, Yoshifusa; Lee, Icksoo; Shrivastav, Shashi; Crusan, Annabelle P.; Hüttemann, Maik; Hopfer, Ulrich; Felder, Robin A.; Asico, Laureano D.; Armando, Ines; Jose, Pedro A.; Kopp, Jeffrey B.

2013-01-01

434

[In situ proximity ligation assay for detection of proteins, their interactions and modifications].  

PubMed

To understand cellular processes and events responsible for their perturbations, proteomic analyses are needed in bio-medical research and clinical diagnostics. Several techniques based on specifically binding reagents (antibodies) or recombinant proteins (GFP fusion protein, methods of fluorescence/?bio-luminescence resonance energy transfer) are generally used to study protein location and activity resulting from secondary modifications and interactions. The in situ proximity ligation assay represents a novel technique of in situ protein imaging using DNA as a reporter molecule and DNA amplification processes. This method enables direct visualization of single molecules, their levels, modifications and pattern of interactions in individual fixed cells and tissues. Proximity probes consist of specific antibody with attached oligonucleotides that are used as reporter molecules for identification of such events. Proximity probes guide the formation of a circular DNA strand when bound in close proximity. The DNA circle after that serves as a template for rolling? circle amplification allowing the interaction to be visualized. Compared to available proteomic techniques benefiting from genetic engineering, in situ PLA enables study of endogenous proteins in their natural environment and thus can be used for clinical specimens. The areas of applicability where proximity ligation procedure can be used include any research field where protein interaction measurements are important, such as signal-ing pathway studies, monitoring of pharmacological treatment targets and oncological diagnostics. PMID:24945543

Brychtová, V; Vojt?šek, B

2014-01-01

435

Lessons learned from a case of proximal humeral locked plating gone awry.  

PubMed

A 59-year-old woman underwent plate fixation of her 2-part anatomic neck proximal humerus fracture through an open anterolateral approach. The fixation subsequently failed, and the operation resulted in a dense axillary nerve palsy. Six weeks after her initial procedure, she was returned to the operating room. Exploration of the nerve revealed that it was compressed beneath the plate and irreparably damaged. Sural nerve cable grafting was required in an attempt to salvage deltoid function. The recent introduction of proximal humeral locking plates provides an opportunity for surgeons to reevaluate their methods of managing proximal humerus fractures. Indications for operative fixation have broadened, and a renewed interest in the anterolateral surgical approach has been reported. This case is the first description of an axillary nerve injury occurring in association with the open anterolateral approach when used for the treatment of a proximal humerus fracture and serves as a reminder that surgeons considering the use of a lateral approach must have a thorough understanding of axillary nerve anatomy. An additional review of the case provides a forum for discussion of the anterolateral approach to the proximal humerus and an opportunity to highlight the methods that can be used to optimize fixation when locked plates are employed. It must be emphasized that our enthusiasm for advances in technique and technology should not distract from basic surgical principles when treating these fractures. PMID:19704279

Nicandri, Gregg T; Trumble, Thomas E; Warme, Winston J

2009-09-01

436

Renal proximal tubule angiotensin AT1A receptors regulate blood pressure  

PubMed Central

All components of the renin angiotensin system necessary for ANG II generation and action have been reported to be present in renal proximal convoluted tubules. Given the close relationship between renal sodium handling and blood pressure regulation, we hypothesized that modulating the action of ANG II specifically in the renal proximal tubules would alter the chronic level of blood pressure. To test this, we used a proximal tubule-specific, androgen-dependent, promoter construct (KAP2) to generate mice with either overexpression of a constitutively active angiotensin type 1A receptor transgene or depletion of endogenous angiotensin type 1A receptors. Androgen administration to female transgenic mice caused a robust induction of the transgene in the kidney and increased baseline blood pressure. In the receptor-depleted mice, androgen administration to females resulted in a Cre recombinase-mediated deletion of angiotensin type 1A receptors in the proximal tubule and reduced blood pressure. In contrast to the changes observed at baseline, there was no difference in the blood pressure response to a pressor dose of ANG II in either experimental model. These data, from two separate mouse models, provide evidence that ANG II signaling via the type 1A receptor in the renal proximal tubule is a regulator of systemic blood pressure under baseline conditions. PMID:21753145

Li, Huiping; Weatherford, Eric T.; Davis, Deborah R.; Keen, Henry L.; Grobe, Justin L.; Daugherty, Alan; Cassis, Lisa A.; Allen, Andrew M.

2011-01-01

437

An Androgen-Inducible Proximal Tubule-Specific Cre-Recombinase Transgenic Model  

PubMed Central

To facilitate the study of renal proximal tubules, we generated a transgenic mouse strain expressing an improved Cre-recombinase (iCre) under the control of the kidney androgen regulated protein (KAP) promoter. The transgene was expressed in the kidney of male mice but not in female mice. Treatment of female transgenic mice with androgen induced robust expression of the transgene in the kidney. We confirmed the presence of Cre-recombinase activity and the cell-specificity by breeding the KAP2-iCRE mice with ROSA26 reporter mice. X-gal staining of kidney sections from male double transgenic mice showed robust staining in the epithelial cells of renal proximal tubules. ?-galactosidase staining in female mice became evident in proximal tubules after administration of androgen. This model of inducible Cre-recombinase in the renal proximal tubule should provide a novel useful tool for studying the physiological significance of genes ex