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Selected AbstractsResidual Limbs of Amputees Are Significantly Cooler than Contralateral Intact LimbsPAIN PRACTICE, Issue 5 2008R. Norman Harden MD ,,Abstract: Objective: To test the hypothesis that distal residual limbs (DRLs) have significant vasomotor abnormalities. Design: Comparative surface temperature studies of DRLs using paired samples (DRL vs. similar site on intact contralateral limb). Subjects/Patients: Thirty-six volunteer subjects with unilateral, upper or lower limb amputations were recruited and evaluated at a pain research center in an urban academic rehabilitation facility. Methods: Our main outcomes were subjects' residual limb temperature as measured by quantitative infrared telethermography (qIRT), temperature strips, and examiner's palpation, compared with the contralateral limb. Results: The qIRT showed that the DRLs were significantly cooler than the corresponding area of the contralateral intact limbs (P < 0.01). The difference using temperature strips supported this finding (P < 0.05); while on physical examination, 39% of the residual limbs were perceived by the examiner as cooler than the corresponding unaffected limbs. Conclusions: DRLs as measured by qIRT were significantly cooler than the corresponding area of the contralateral intact limbs. A better understanding of these findings may be important in elucidating the pathophysiology of relevant clinical features such as a potential sympathetic component of postamputation pain.,, [source] Resolving the enigma of early coastal settlement in the Hawaiian Islands: The stratigraphic sequence of the Wainiha Beach Site in Kaua'iGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 2 2004Mike T. Carson Archaeological excavation has documented stratified cultural deposits at the Wainiha Beach Site in Kaua'i (Hawaiian Islands), beginning with the occupation of a residential structure dated around A.D. 1030,1400. After about A.D. 1400, the excavated area contains abundant evidence of widespread repeated temporary activities ending in the post-Contact era (post-A.D. 1778). The presence of an early permanent residence followed by a later period of temporary activities opposes conventional understanding of a trend from temporary to permanent occupation in similar sites in the Hawaiian Islands. The complete stratigraphic sequence is disclosed here, with reference to formation processes and depositional context of eight major strata documented in a controlled excavation 0.95 m deep. Various human activities (such as digging pits, trampling, etc.) and periodic natural high-energy events (such as tsunami) appear to have altered the upper portions of underlying deposits. Large sections of the earliest human occupation layer were obliterated, and successive episodes of short-lived activities created numerous inconsistencies in the stratigraphy. These results have important implications for interpreting the cultural sequence not only at Wainiha but also at other rather enigmatic beach sites in the Hawaiian Islands and elsewhere. © 2004 Wiley Periodicals, Inc. [source] The Versatility of Helicobacter pylori CagA Effector Protein Functions: The Master Key HypothesisHELICOBACTER, Issue 3 2010Steffen Backert Abstract Several bacterial pathogens inject virulence proteins into host target cells that are substrates of eukaryotic tyrosine kinases. One of the key examples is the Helicobacter pylori CagA effector protein which is translocated by a type-IV secretion system. Injected CagA becomes tyrosine-phosphorylated on EPIYA sequence motifs by Src and Abl family kinases. CagA then binds to and activates/inactivates multiple signaling proteins in a phosphorylation-dependent and phosphorylation-independent manner. A recent proteomic screen systematically identified eukaryotic binding partners of the EPIYA phosphorylation sites of CagA and similar sites in other bacterial effectors by high-resolution mass spectrometry. Individual phosphorylation sites recruited a surprisingly high number of interaction partners suggesting that each phosphorylation site can interfere with many downstream pathways. We now count 20 reported cellular binding partners of CagA, which represents the highest quantitiy among all yet known virulence-associated effector proteins in the microbial world. This complexity generates a highly remarkable and puzzling scenario. In addition, the first crystal structure of CagA provided us with new information on the function of this important virulence determinant. Here we review the recent advances in characterizing the multiple binding signaling activities of CagA. Injected CagA can act as a ,master key' that evolved the ability to highjack multiple host cell signalling cascades, which include the induction of membrane dynamics, actin-cytoskeletal rearrangements and the disruption of cell-to-cell junctions as well as proliferative, pro-inflammatory and anti-apoptotic nuclear responses. The discovery that different pathogens use this common strategy to subvert host cell functions suggests that more examples will emerge soon. [source] Power function decay of hydraulic conductivity for a TOPMODEL-based infiltration routineHYDROLOGICAL PROCESSES, Issue 18 2006Jun Wang Abstract TOPMODEL rainfall-runoff hydrologic concepts are based on soil saturation processes, where soil controls on hydrograph recession have been represented by linear, exponential, and power function decay with soil depth. Although these decay formulations have been incorporated into baseflow decay and topographic index computations, only the linear and exponential forms have been incorporated into infiltration subroutines. This study develops a power function formulation of the Green and Ampt infiltration equation for the case where the power n = 1 and 2. This new function was created to represent field measurements in the New York City, USA, Ward Pound Ridge drinking water supply area, and provide support for similar sites reported by other researchers. Derivation of the power-function-based Green and Ampt model begins with the Green and Ampt formulation used by Beven in deriving an exponential decay model. Differences between the linear, exponential, and power function infiltration scenarios are sensitive to the relative difference between rainfall rates and hydraulic conductivity. Using a low-frequency 30 min design storm with 4·8 cm h,1 rain, the n = 2 power function formulation allows for a faster decay of infiltration and more rapid generation of runoff. Infiltration excess runoff is rare in most forested watersheds, and advantages of the power function infiltration routine may primarily include replication of field-observed processes in urbanized areas and numerical consistency with power function decay of baseflow and topographic index distributions. Equation development is presented within a TOPMODEL-based Ward Pound Ridge rainfall-runoff simulation. Copyright © 2006 John Wiley & Sons, Ltd. [source] Oxidative degradation of 4-nitrophenol in UV-illuminated titania suspensionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2001Jimmy Lea Abstract An internally-irradiated annular photoreactor has been used to investigate the oxidative degradation of aqueous 4-nitrophenol with titania as the photocatalyst. Reaction runs were performed over a 3-h period and in practically all cases, complete degradation was possible within about 2,h. The kinetics was determined as a function of nitrophenol concentration, oxygen partial pressure, catalyst loading, pH, temperature and light intensity. The reaction was characterised by a relatively low activation energy of 7.83,kJ,mol,1 although transport intrusions were negligible. Rate decreased almost exponentially with pH while a quadratic (maximum) behaviour with respect to both oxygen pressure and nitrophenol concentration is symptomatic of self-inhibition possibly due to the formation of intermediates which competitively adsorb on similar sites to the reactants. Increased catalyst dosage also improved the reaction rate although the possible effects of light scattering and solution opacity caused a drop at loadings higher than about 1.20,g,dm,3. Rate, however, has a linear dependency on light intensity, suggesting that hole,electron recombination processes were negligible at the conditions investigated. © 2001 Society of Chemical Industry [source] Caffeine inhibition of ionotropic glycine receptorsTHE JOURNAL OF PHYSIOLOGY, Issue 16 2009Lei Duan We found that caffeine is a structural analogue of strychnine and a competitive antagonist at ionotropic glycine receptors (GlyRs). Docking simulations indicate that caffeine and strychnine may bind to similar sites at the GlyR. The R131A GlyR mutation, which reduces strychnine antagonism without suppressing activation by glycine, also reduces caffeine antagonism. GlyR subtypes have differing caffeine sensitivity. Tested against the EC50 of each GlyR subtype, the order of caffeine potency (IC50) is: ,2, (248 ± 32 ,m) ,,3, (255 ± 16 ,m) > ,4, (517 ± 50 ,m) > ,1,(837 ± 132 ,m). However, because the ,3, GlyR is more than 3-fold less sensitive to glycine than any of the other GlyR subtypes, this receptor is most effectively blocked by caffeine. The glycine dose,response curves and the effects of caffeine indicate that amphibian retinal ganglion cells do not express a plethora of GlyR subtypes and are dominated by the ,1, GlyR. Comparing the effects of caffeine on glycinergic spontaneous and evoked IPSCs indicates that evoked release elevates the glycine concentration at some synapses whereas summation elicits evoked IPSCs at other synapses. Caffeine serves to identify the pharmacophore of strychnine and produces near-complete inhibition of glycine receptors at concentrations commonly employed to stimulate ryanodine receptors. [source] Relationship Between Aboveground Biomass and Multiple Measures of Biodiversity in Subtropical Forest of Puerto RicoBIOTROPICA, Issue 3 2010Heather D. Vance-Chalcraft ABSTRACT Anthropogenic activities have accelerated the rate of global loss of biodiversity, making it more important than ever to understand the structure of biodiversity hotspots. One current focus is the relationship between species richness and aboveground biomass (AGB) in a variety of ecosystems. Nonetheless, species diversity, evenness, rarity, or dominance represent other critical attributes of biodiversity and may have associations with AGB that are markedly different than that of species richness. Using data from large trees in four environmentally similar sites in the Luquillo Experimental Forest of Puerto Rico, we determined the shape and strength of relationships between each of five measures of biodiversity (i.e., species richness, Simpson's diversity, Simpson's evenness, rarity, and dominance) and AGB. We quantified these measures of biodiversity using either proportional biomass or proportional abundance as weighting factors. Three of the four sites had a unimodal relationship between species richness and AGB, with only the most mature site evincing a positive, linear relationship. The differences between the mature site and the other sites, as well as the differences between our richness,AGB relationships and those found at other forest sites, highlight the crucial role that prior land use and severe storms have on this forest community. Although the shape and strength of relationships differed greatly among measures of biodiversity and among sites, the strongest relationships within each site were always those involving richness or evenness. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source] | |||||||||||||