Late Part Research Articles

About “Chronic low-dose aspirin therapy attenuates reflex cutaneous vasodilatation in middle-aged humans”

LETTERS TO THE EDITORAbout “Chronic low-dose aspirin therapy attenuates reflex cutaneous vasodilatation in middle-aged humans”G. Mahe, P. Rousseau, J. L. Saumet, and P. AbrahamG. Mahe, P. Rousseau, J. L. Saumet, and P. AbrahamPublished Online:01 Apr 2009https://doi.org/10.1152/japplphysiol.91653.2008MoreSectionsPDF (27 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: We read with much interest the article by Holowatz and Kenney (3) entitled “Chronic low-dose aspirin therapy attenuates reflex cutaneous vasodilatation in middle-aged humans.” The authors showed that chronic aspirin therapy (81 mg/day) plays a major role in the reflex cutaneous vasodilatation induced by whole body heating. This result is consistent with those reported by McCord et al. (4) that showed that the cyclooxygenase-dependent (COX) pathway was participating in the cutaneous vasodilatation induced by whole body heating but not by local heating. Vasodilatation induced by local heating relies on an axon-reflex for the early response and on a nitric oxide (NO)-dependent pathway for the late part of the response (5). On the contrary, vasodilatation induced by whole body heating depends on the NO pathway and the COX pathway but not on an axon-reflex (1, 3). The whole body heating is an interesting experimental model to study physiological responses during heat waves. Heat waves are an important health problem. Heat waves were estimated directly or indirectly to be responsible for ∼70,000 elderly deaths in Europe in 2003. Many elderly subjects take low-dose aspirin (<325 mg/day) as an effective therapy in prevention of cardiovascular diseases. As whole body heat-induced vasodilatation depends on the COX pathway even at low dose as shown by Holowatz and Kenney, do we need to stop low-dose aspirin therapy during heat waves? Other antiplatelet drugs exist (such as ADP inhibitors). We showed that the current-induced vasodilatation (CIV), another model of skin vasodilatation, was COX dependent(2) but not ADP dependent (6). Whether the whole body heating model is ADP dependent is an important issue. If not, rather than stop aspirin, should we recommend the use of antiplatelet drugs other than aspirin during heat waves? Future studies are likely needed to investigate this important clinical issue.REFERENCES1 Charkoudian N, Fromy B, Saumet JL. Reflex control of the cutaneous circulation after acute and chronic local capsaicin. J Appl Physiol 90: 1860–1864, 2001.Link | ISI | Google Scholar2 Durand S, Fromy B, Bouye P, Saumet JL, Abraham P. Vasodilatation in response to repeated anodal current application in the human skin relies on aspirin-sensitive mechanisms. J Physiol 540: 261–269, 2002.Crossref | PubMed | ISI | Google Scholar3 Holowatz LA, Kenney WL. Chronic low-dose aspirin therapy attenuates reflex cutaneous vasodilation in middle-aged humans. J Appl Physiol 106: 500–505, 2009.Link | ISI | Google Scholar4 McCord GR, Cracowski JL, Minson CT. Prostanoids contribute to cutaneous active vasodilation in humans. Am J Physiol Regul Integr Comp Physiol 291: R596–R602, 2006.Link | ISI | Google Scholar5 Minson CT, Berry LT, Joyner MJ. Nitric oxide and neurally mediated regulation of skin blood flow during local heating. J Appl Physiol 91: 1619–1626, 2001.Link | ISI | Google Scholar6 Rousseau P, Tartas M, Fromy B, Godon A, Custaud MA, Saumet JL, Abraham P. Platelet inhibition by low-dose aspirin but not by clopidogrel reduces the axon-reflex current-induced vasodilation in humans. Am J Physiol Regul Integr Comp Physiol 294: R1420–R1426, 2008.Link | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: G. Mahe, Univ. Hospital, 4, Rue Larrey, 49000 Angers, France (e-mail: [email protected]) Download PDF Previous Back to Top Next FiguresReferencesRelatedInformationCited ByReply to Mahe, Rousseau, Saumet, and AbrahamLacy A. Holowatz and W. Larry Kenney1 April 2009 | Journal of Applied Physiology, Vol. 106, No. 4 More from this issue > Volume 106Issue 4April 2009Pages 1471-1471 Copyright & PermissionsCopyright © 2009 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.91653.2008PubMed19336681History Published online 1 April 2009 Published in print 1 April 2009 Metrics

Climate‐driven changes in lake conditions during late MIS 3 and MIS 2: a high‐resolution geochemical record from Les Echets, France

A new set of geochemical data obtained from a long sediment sequence from the Les Echets basin provides a new record of palaeoenvironmental change for western Europe. The sequence covers the late part of Marine Isotope Stage (MIS) 3 and MIS 2 (c. 46.1–15.0 cal. kyr BP) and extends over 30 m of sediment, allowing for high sampling resolution. Distinct cyclic fluctuations in aquatic productivity proxies suggest a tempo of environmental change at Les Echets that resembles the one established for Dansgaard‐Oeschger cycles and Heinrich events. Increases in organic carbon are paralleled by high hydrogenous contents and enriched δ13Corg and Corg/Ntot ratios, implying a mixture of aquatic and land‐derived constituents. The stable isotope values are directly linked to primary aquatic productivity and the input of terrestrial organic matter, enriched during warm, productive, periods, and drastically depleted during cold periods, particularly Heinrich events. Phases of relatively high productivity correlate with Dansgaard‐Oeschger interstadials 8–2, while Heinrich events 3 and 2 are also clearly delineated by distinct lithological horizons with very low organic contents, high dry densities and enhanced organic matter oxidation. A large hiatus occurring about the time of Heinrich event 4 suggests that the cold and dry climate reconstructed for this event in the North Atlantic region also greatly affected Les Echets and its catchment.

Dynamic Causal Modeling of the Response to Frequency Deviants

This article describes the use of dynamic causal modeling to test hypotheses about the genesis of evoked responses. Specifically, we consider the mismatch negativity (MMN), a well-characterized response to deviant sounds and one of the most widely studied evoked responses. There have been several mechanistic accounts of how the MMN might arise. It has been suggested that the MMN results from a comparison between sensory input and a memory trace of previous input, although others have argued that local adaptation, due to stimulus repetition, is sufficient to explain the MMN. Thus the precise mechanisms underlying the generation of the MMN remain unclear. This study tests some biologically plausible spatiotemporal dipole models that rest on changes in extrinsic top-down connections (that enable comparison) and intrinsic changes (that model adaptation). Dynamic causal modeling suggested that responses to deviants are best explained by changes in effective connectivity both within and between cortical sources in a hierarchical network of distributed sources. Our model comparison suggests that both adaptation and memory comparison operate in concert to produce the early (N1 enhancement) and late (MMN) parts of the response to frequency deviants. We consider these mechanisms in the light of predictive coding and hierarchical inference in the brain.

Election outcomes and financial market returns in Canada

This paper investigates the relationship between federal election outcomes and expected returns and volatilities in the Canadian money, bond, equity and currency markets from 1951 to 2006. There is little evidence that investment opportunities are different in minority versus majority parliaments and only money market returns differ in Conservative versus Liberal governments. The equity market performs better in the late part of the electoral cycle than in the first two years. Furthermore, the Canadian equity investment opportunities are better in Democratic versus Republican administrations and in the late versus early parts of the presidential electoral cycle. The Canadian dollar is also affected by American election outcomes. No apparent variation in risk or expected state of the economy accounts for the differences in returns.

Moors, Fields, and Popular Protest in South Lancashire and the West Riding of Yorkshire, 1800–1848

During the late eighteenth and first part of the nineteenth century, certain moors and fields in south Lancashire and the West Riding of Yorkshire were repeatedly used as sites for meetings, demonstrations, and other political gatherings. Historians have recently indicated how rituals, symbols, and texts helped to shape the political culture of radical societies and trade unions in this period. This article argues that the semirural landscape was another, perhaps more enduring, layer to this culture. Luddites, strikers, radicals, and Chartists employed particular sites, not just as venues for political activity, but also as an essential part of the symbol and ritual of protest. Mass meetings on moors and fields were spectacles: liminal spaces where free speech could be expressed and radical histories could be formed. Yet everyday life also influenced the nature of moorland protests. The daily uses and perceptions of landscape could be as significant in shaping inhabitants' political outlooks as occasional set-piece demonstrations. Demonstrations on moors reflected popular defiance of restrictions on public space and wider awareness of the effects of industrialization upon use of the land and communications.

Resonant seismic emission of subsurface objects

Numerical modeling results and field data indicate that some contrasting subsurface objects (such as tunnels, caves, pipes, filled pits, and fluid-filled fractures) are capable of generating durable resonant oscillations after trapping seismic energy. These oscillations consist of surface types of circumferential waves that repeatedly propagate around the object. The resonant emission of such trapped energy occurs primarily in the form of shear body waves that can be detected by remotely placed receivers. Resonant emission reveals itself in the form of sharp resonant peaks for the late parts of the records, when all strong direct and primary reflected waves are gone. These peaks were observed in field data for a buried barrel filled with water, in 2D finite-difference modeling results, and in the exact canonical solution for a fluid-filled sphere. A computed animation for the diffraction of a plane wave upon a low-velocity elastic sphere confirms the generation of resonances by durable surface waves. Resonant emission has characteristic quasi-hyperbolic traveltime patterns on shot gathers. The inversion of these patterns can be performed in the frequency domain after muting the strong direct and primary scattered waves. Subsurface objects can be detected and imaged at a single resonance frequency without an accurate knowledge of source trigger time. The imaging of subsurface objects requires information about the shear velocity distribution in an embedding medium, which can be done interactively during inversion.

Microbiological and biochemical changes during processing of the traditional chinese food douzhi

The microbiological and biochemical changes during douzhi processing were studied. The sedimentation process was shown to follow a lactic fermentation course. The main fermenting bacteria were identified to be Lactococcus lactis and Leuconostoc citreum; the former played the main role in producing acids, and the latter ensured a better flavor of douzhi. Yeasts thrived during the late part of fermentation were believe to account for the decrease in acidity. Tracing the change of chemical compounds suggested that active metabolic activity was induced when beans were steeped in water, in which significant reduction in crude protein and sugars were observed, but levels of soluble proteins, free amino acids increased. Fermentation by lactic acid bacteria caused a rapid reduction of soluble proteins, soluble sugars and reducing sugars, but significant accumulation of free amino acids and slight changes in crude protein. Mung bean endogenous protease and amylase activity dropped significantly during fermentation.

Vegetational and environmental history during the Holocene in the Esbjerg area, west Jutland, Denmark

A pollen diagram from a site in the Esbjerg area, western Denmark, is used for reconstruction of the Holocene vegetational and environmental history there. During the Atlantic there was a parallel development of the landscape to that of other areas in Jylland (Jutland). From the late Neolithic onwards the development took its own course related to the approaching North Sea, which periodically inundated parts of the Esbjerg area. The record reflects landscape development in a formerly marine valley where sediments seem to be missing from parts of the Bronze Age and the early Iron Age. Consequently the landscape development during these times is only reflected in glimpses in the vegetation record, which shows gradually more open woodland and increasing human impact. During the late part of the Iron Age, Viking period and Middle Ages, the woodland was diverse in taxa but became increasingly open, finally reaching a stage during which there may have been too little wood even for daily use. At the same time the use of the land intensified. During the Sub-Atlantic, the Esbjerg area offered good natural resources with extensive grazing areas in the marine marshes in addition to good possibilities for farming and use of the woodland on higher ground, but devastating floods occurred.

Effects of intermodal attention on the auditory steady‐state response and the event‐related potential

The aim of the present study was to simultaneously measure and compare intermodal attention effects in event-related brain potentials (ERPs) and auditory steady-state responses (ASSRs). For this purpose, 40-Hz amplitude modulated tones and a visual fixation cross were presented concurrently. By means of target detection tasks either on the sounds or on the fixation cross, participants' attention was directed to the respective modality. Attended sounds elicited a negative difference (Nd) in the ERP relative to unattended sounds. Nd was divided into an early and a late part as often observed for intramodal attention. Moreover, attention to the sounds led to a significant enhancement of the ASSR. This modulation of the ASSR by intermodal attention is demonstrated for the first time in the EEG. The present data suggest that ASSRs could provide a useful tool for the investigation of the neural dynamics of intermodal attentional processes.

Role of intracortical mechanisms in the late part of the silent period to transcranial stimulation of the human motor cortex.

Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the human motor cortex produce a silent period (SP) following motor evoked potentials (MEPs). The early part of the SP can be explained by decreased alpha motor neuron excitability, whereas the late part is presumably due to suprasegmental mechanisms. In order to determine the level of the suprasegmental contribution of the generation of SPs, we recorded excitatory and inhibitory responses to TMS, TES and percutaneous electrical brainstem stimulation (PBS) in the voluntarily activated first dorsal interosseous muscle of the hand. Stimulus intensities were set so that PBS and TES induced MEPs with areas equal to or larger than those of MEPs obtained with TMS. This procedure revealed that SPs were 49% and 83% shorter with TES and PBS, respectively, than with TMS. As TMS is more effective than TES or PBS in activating cortical interneurons, these findings support the idea that a significant component of the SP arises from intracortical mechanisms.

Comparative Analysis of the Distribution of Daily Rainfall Amounts at three Stations in Northern Nigeria

The distributions of daily rainfall amounts at three stations in the savanna vegetative zone of northern Nigeria were studied. The lengths of the rainfall data series ranged from 66 to 81years and covered the period from 1916 to 1999. The data series of each station was divided into two segments with those predating 1961 (i.e. up to year 1960) as at first. The data series for the period from 1961 onwards, which generally showed a declining trend of annual number of rainy days, constituted the second segment. Comparison using cumulative probability ploys and a non-parametric statistical test showed that corresponding distributions in both segments were similar when the data partitioned to two antecedent rainfall-states (i.e. rainy day preceding rainy day and dry day preceding rainy day) and also when partitioned to the early, middle and late parts of the wet season. The result suggested that the data from both segments belonged to the same population and were therefore combined to derive the parameters of a gamma distribution model used stochastically generate daily rainfall data for the stationary part of the series. The Statistical properties of the simulated and observed data were comparable suggesting that the derived model parameters are representative of the series. JARD Vol. 2 2003: pp. 70-86

An Analysis of Improving Memory Performance Based on EEG Alpha and Theta Oscillations

Evidence is presented that EEG oscillations in the alpha and theta band reflect memory performance in particular. Good performance is related to two types of EEG phenomena: a tonic increase in alpha but a decrease in theta power, and a large phasic decrease in alpha but increase in theta, depending on the type of memory demands. In a similar way as brain volume does, upper alpha power increases from early childhood to adulthood, whereas the opposite holds true for the late part of the lifespan. Alpha power is lowered and theta power enhanced in subjects with a variety of different neurological disorders. Furthermore, after sustained wakefulness and during the transition from waking to sleeping when the ability to respond to external stimuli ceases, upper alpha power decreases, whereas theta increases. Event-related changes indicate that the extent of upper alpha desynchronization is positively correlated with (semantic) long-term memory performance, whereas theta synchronization is positively correlated with the ability to encode new information.

Baseline Values and Sotalol‐Induced Changes of Ventricular Repolarization Duration, Heterogeneity, and Instability in Patients With a History of Drug‐Induced Torsades de Pointes

The authors investigated whether computerized parameters quantifying ventricular repolarization delay, heterogeneity, and instability characterize individuals who developed drug-induced Torsades de Pointes. Assessing an individual's propensity to Torsades de Pointes when exposed to a QT-prolonging drug is challenging because baseline QT prolongation has limited predictive value. Five-minute digital 12-lead electrocardiograms were acquired at baseline and after a sotalol challenge in 16 patients who had a history of Torsades de Pointes in the context of a QT-prolonging drug and 17 patients who did not have such history. Computerized measurements of QTc, T peak to T end intervals (TpTe), TpTe/QTc, and QT variability were implemented, and novel quantifiers of ventricular repolarization heterogeneity from the early (ERD) and late (LRD) part of the T wave were investigated. Compared with electrocardiograms of patients without a history of Torsades de Pointes, the baseline electrocardiograms of patients with a history of Torsades de Pointes had a longer QTc and an increased repolarization heterogeneity of the early part of the T wave (ERD30%: 44 +/- 13 vs 35 +/- 8 ms, P = .02). On sotalol, the electrocardiograms from individuals with Torsades de Pointes revealed a delay of the terminal part of the T wave that was not present in patients without Torsades de Pointes (TpTe: 27 +/- 40 vs -2 +/- 21 ms, P = .02; LRD70%: 20 +/- 29 vs 2 +/- 4 ms, P = .04). Results suggest that the electrocardiogram abnormalities characterizing patients with a history of Torsades de Pointes are (1) an increased repolarization heterogeneity at baseline and (2) a sotalol-induced prolongation of the terminal part of the T wave.

Palynostratigraphy from the Lower devonian of the Paraná Basin, South Brazil, and a revision of contemporary chitinozoan biozones from Western Gondwana

New palynomorph data from the Paraná Basin, south Brazil, suggests a discontinuous sedimentation during the Lower Devonian. A comparison is made with coeval beds in Argentina, Bolivia and other intracratonic basins from Brazil. The Lochkovian/Pragian boundary is best developed in Bolivia and is distinguished by the first appearance of Ramochitina magnifica Lange 1967, which succeeds characteristic late Lochkovian chitinozoan species from underlying strata (e.g. Angochitina filosa Eisenack 1959, Cingulochitina ervensis Paris 1979, Cingulochitina serrata Taugourdeau and Jekhowsky 1960, Ramochitina jutaiense Grahn et al. 2003, and Urochitina loboi Volkheimer et al. 1986). Based on spore evidence, the Urochitina loboi Zone is considered as a subzone in the upper late Lochkovian part of the Angochitina strigosa Zone. A palynomorphic barren interval, corresponding to most of the Pragian (PoW, pre-Su spore Interval Zone of Streel et al. 1987), occurs in Western Gondwana. No positive evidence is present for rocks coeval with the Emsian AB and FD spore Oppel Zones of Streel et al. (1987). Ancyrochitina biconstricta (Lange 1949) is a characteristic Emsian species, and not conspecific with Cladochitina biconstricta Lange 1949 sensu Quadros 1982, which is a new late Eifelian – late early Givetian species. Ramochitina praemagnifica and Spinachitina aciculata, are described as new species.

Perception and suppression of thermally induced pain: A fMRI study

Two neuroimaging studies using functional magnetic resonance imaging (fMRI) and thermally induced pain are presented. Fifteen healthy right-handed subjects were imaged while they had to discern different levels of thermal stimuli in the first study and while they disengaged from the feeling of pain during constant stimulation in the second study. In the first experiment, during painful phasic stimuli, right-sided anterior insular activation as well as bilateral posterior insular activation could be shown regardless of stimulation side, as well as right-sided activation of sensory association areas in the superior parietal lobule. Also, activation of the ipsilateral sensorimotor cortex could be shown. In the second experiment, all subjects succeeded in suppressing the feeling of pain during previously painful levels of stimulation. During the early part of the tonic painful stimulation, bilateral activation of caudate head and dorsolateral prefrontal cortex (DLPFC) as well as insular cortex and dorsal anterior cingulated cortex (dACC) was observed. During the late part of the tonic painful stimulation, anterior insular activation as well as dACC and bilateral prefrontal cortical activation could be shown. Taken together, the activation of PFC and caudate nucleus hints at an important role in the initiation (caudate) and maintenance (PFC) of suppression of the feeling of pain. No ipsilateral sensorimotor activation could be shown in the second experiment. The possible import of unwanted sensorimotor activation due to the simultaneous rating process in the first experiment is discussed.

Late parietal positive waves to a subject’s own name in unresponsive patients

Event Abstract Back to Event Late parietal positive waves to a subject’s own name in unresponsive patients Dominique Morlet1, 2*, I. Holeckova3, P. Ruby1, 2, J. B. Eichenlaub1, 2 and C. Fischer1, 2, 4 1 Inserm U821, Brain Dynamics and Cognition, France 2 Université Lyon 1, France 3 Medical Faculty Plzen, Charles IV University Prague, Czechia 4 Neurological Hospital, Department of Clinical Neurophysiology, France We report here a series of findings from passive oddball paradigms (tone bursts as standards and deviants) including the subject’s own name (SON) presented as a novel (p ≤ 0.03) in healthy awake subjects and in unresponsive patients. In a first experiment (15 healthy subjects), the SON was randomly uttered either by an unknown voice or by a familiar voice in the same stimulation block. Both types of novels elicited a large novelty P3 response, with slightly enhanced amplitudes in the late part of the wave for the familiar voice. The most important difference between the two types of novels was a late parietal positivity appearing after the novelty P3, only in response to the familiar voice. In a second experiment (12 healthy subjects), the SON uttered by an unknown voice and the SON uttered by a familiar voice were presented in separate blocks. Both novels elicited similar novelty P3 responses as in the first experiment, but no late parietal positivity could be observed in either condition. In a third experiment (11 healthy subjects), the SON and another unfamiliar proper name were uttered by an unknown voice and randomly presented in the same block. A large late parietal positive wave followed novelty P3 only in response to the SON. The passive oddball paradigm including only the SON uttered by an unknown voice was applied in 50 severe comatose patients on average 20 days after coma onset. The SON elicited a central-parietal P3 response in 21 of these patients, of whom 17 awoke within the next 3 months. In 12 patients (of whom 11 woke up), we observed an additional component with more pronounced parietal predominance, significantly prolonging the duration of the P3 response. These studies demonstrate that, in healthy subjects, the presence of late parietal positive waves in response to SON depends highly on the stimulation context. This result questions about the cognitive counterpart of these components. Moreover, late parietal positivities can also be observed in supposedly unconscious patients in whom they could highlight some cognitive activity. Conference: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications, Budapest, Hungary, 4 Apr - 7 Apr, 2009. Presentation Type: Poster Presentation Topic: Poster Presentations Citation: Morlet D, Holeckova I, Ruby P, Eichenlaub JB and Fischer C (2009). Late parietal positive waves to a subject’s own name in unresponsive patients. Conference Abstract: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications. doi: 10.3389/conf.neuro.09.2009.05.058 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 24 Mar 2009; Published Online: 24 Mar 2009. * Correspondence: Dominique Morlet, Inserm U821, Brain Dynamics and Cognition, Lyon, France, dominique.morlet@inserm.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Dominique Morlet I. Holeckova P. Ruby J. B Eichenlaub C. Fischer Google Dominique Morlet I. Holeckova P. Ruby J. B Eichenlaub C. Fischer Google Scholar Dominique Morlet I. Holeckova P. Ruby J. B Eichenlaub C. Fischer PubMed Dominique Morlet I. Holeckova P. Ruby J. B Eichenlaub C. Fischer Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

C-terminal Loop 13 of Na+/Glucose Cotransporter 1 Contains Both Stereospecific and Non-stereospecific Sugar Interaction Sites

To investigate whether the C-terminal loop 13 of rabbit sodium/glucose cotransporter SGLT1 is involved in the recognition of the substrate d-glucose, isolated loop 13 (amino acids (aa) 541-638) was immobilized to a lipid bilayer. Interactions were investigated by surface plasmon resonance spectroscopy using an antibody directed against the late part of the loop (aa 606-631) or the glucoside transport inhibitor phlorizin. Specific binding of the antibody to the loop could be detected. The number of bound antibodies decreased upon the addition of d-glucose but not upon the addition of l-glucose. Phlorizin also significantly lowered the number of bound antibodies. Binding of phlorizin to the loop could also be demonstrated directly. Binding of phlorizin was, however, reduced to a similar extent upon the addition of either d-glucose or l-glucose, indicating their unspecific competition with the inhibitor's sugar moiety. Thus, the presence of a stereospecific glucose interaction site in the late part of the loop and a second, but non-stereospecific, sugar binding site on the same loop was assumed. To investigate whether the early part of loop 13 contains this non-stereospecific sugar binding site, peptides containing aa 541-598 were expressed in Escherichia coli and purified. Both d-glucose and l-glucose quenched the peptides tryptophan fluorescence and reduced the Trp accessibility to acrylamide to a similar degree. In view of the recently proposed transmembrane orientation of loop 13, the two binding sites may be part of the extracellular (stereospecific) and intracellular (non-stereospecific) sugar interaction sites of SGLT1.

Unraveling Results from Comparable Demand and Supply: An Experimental Investigation

Markets sometimes unravel, with offers becoming inefficiently early. Often this is attributed to competition arising from an imbalance of demand and supply, typically excess demand for workers. However this presents a puzzle, since unraveling can only occur when firms are willing to make early offers and workers are willing to accept them. We present a model and experiment in which workers' quality becomes known only in the late part of the market. However, in equilibrium, matching can occur (inefficiently) early only when there is comparable demand and supply: a surplus of applicants, but a shortage of high quality applicants.

Non-invasive detection of conduction pathways to left atrium using magnetocardiography: validation by intra-cardiac electroanatomic mapping

Alteration in conduction from right to left atrium (LA) is linked to susceptibility to atrial fibrillation (AF). We examined whether different inter-atrial conduction pathways can be identified non-invasively by magnetocardiographic mapping (MCG). In 27 patients undergoing catheter ablation of paroxysmal AF, LA activation sequence was determined during sinus rhythm using invasive electroanatomic mapping. Before this, 99-channel magnetocardiography was recorded over anterior chest. The orientation of the magnetic fields during the early (40-70 ms from P onset) and later part (last 50%) of LA depolarization was determined using pseudocurrent conversion. Breakthrough of electrical activation to LA occurred through Bachmann bundle (BB) in 14, margin of fossa ovalis (FO) in 3, coronary sinus ostial region (CS) in 2, and their combinations in 10 cases by invasive reference in total of 29 different P-waves. Based on the combination of pseudocurrent angles over early and late parts of LA activation, the MCG maps were divided to three types. These types correctly identified the LA breakthrough sites to BB, CS, FO, or their combinations in 27 of 29 (93%) cases. Magnetocardiographic mapping seems capable of distinguishing inter-atrial conduction pathways. Recognizing the inter-atrial conduction pattern may assist in understanding the pathogenesis of AF and identifying the subgroups for patient-tailored therapy.

Mastication-induced modulation of the jaw-opening reflex during different periods of mastication in awake rabbits

The present study aimed to determine if sensory inputs from the intraoral mechanoreceptors similarly contributed to regulating the activity of the jaw-opening muscles throughout the masticatory sequence. We also aimed to determine if sensory inputs from the chewing and non-chewing sides equally regulated the activity of the jaw-opening muscles. Electromyographic (EMG) activities of jaw muscles (digastric and masseter) and jaw movements were recorded in awake rabbits. The entire masticatory sequence was divided into preparatory, rhythmic-chewing and preswallow periods, based on jaw muscles activity and jaw movements. The jaw-opening reflex (JOR) was evoked by unilateral low-intensity stimulation of the inferior alveolar nerve (IAN) on either the chewing or non-chewing side. Amplitude of the JOR was assessed by measuring peak-to-peak EMG activity in the digastric muscle, and was compared among the masticatory periods and between the chewing and non-chewing sides. The JOR was strongly suppressed during the jaw-closing phase in the rhythmic-chewing and preswallow periods, but this effect was transiently attenuated during the late part of the jaw-opening phase in these periods. However, modulation of the JOR varied from strong suppression to weak facilitation during the preparatory period. The patterns of JOR modulation were similar on the chewing and non-chewing sides in all masticatory periods. The results suggest that the sensory inputs from the intraoral mechanoreceptors regulate the activity of the jaw-opening muscles differently during the preparatory period compared with the other masticatory periods. Sensory inputs from both the chewing and non-chewing sides similarly regulate the activity of the jaw-opening muscles.