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Transit
Kinds of Transit Terms modified by Transit Selected AbstractsMOVING VIOLATIONS: DATA PRIVACY IN PUBLIC TRANSITGEOGRAPHICAL REVIEW, Issue 3 2007NANCY J. OBERMEYER ABSTRACT. This article draws from the foundation provided by the ongoing debate about geosurveillance to frame a discussion of the use of tracking technologies in public transit. Specifically, it uses the case of public transit to illustrate the uncomfortable debate about compromises that come with increased surveillance to enhance public safety and security. The article begins with a discussion of the evolution of the debate about geosurveillance, casting the use of surveillance technologies in public transit within this framework. Next, it describes and discusses the implementation of automatic vehicle locators and closed-circuit television in public transit. The following sections focus on the risks to individual privacy that accompany implementation of these technologies, then describe an unusual effort to draw attention to the prevalence of increased surveillance in public spaces in an effort to expose the risks. The article concludes by making the case that public transit is a place where surveillance provides clear benefits but where the humans who review the surveillance data must interpret and use them responsibly to minimize the risks to individual privacy. [source] PERIPHERAL AND CENTRALLY MEDIATED EFFECTS OF INSULIN ON SMALL INTESTINAL TRANSIT IN HEALTHY MICECLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2006MK Peddyreddy SUMMARY 1Insulin is the drug of choice in the management of type 1 diabetes mellitus. Approximately 76% of diabetic patients suffer from gastrointestinal disorders. An important area of investigating the inherent effect of insulin on small intestinal transit (SIT) remains unexplored. Hence, the present study was planned to investigate the effects of insulin (2 × 10,6, 2 × 10,3 and 2 U/kg) on small intestinal transit following two different routes of administration in healthy animals. 2Insulin or vehicle was administered subcutaneously or intracerebroventricularly in eight groups of healthy, overnight-fasted mice. Blood glucose (BG) levels were measured 2 min before insulin administration and at the time coinciding with SIT determination. Small intestinal transit was determined 50 min after insulin administration using the charcoal meal method. 3Following subcutaneous administration, the lowest dose of insulin (2 × 10,6 U/kg) produced a significant acceleration in SIT without altering BG levels. However, the highest dose of insulin (2 U/kg) produced an acceleration of SIT that was associated with a significant fall in BG levels. 4Following intracerebroventricular administration, the lowest dose of insulin (2 × 10,6 U/kg) attenuated SIT, without producing any alteration in BG levels, but the highest dose (2 U/kg) mimicked the effects seen following subcutaneous administration. Peripherally administered insulin produced significant acceleration of SIT at lower doses (2 × 10,6 or 2 × 10,3 mU/kg) compared with centrally administered insulin at similar doses. However, at the highest dose of insulin (2 U/kg), both routes (s.c. and i.c.v.) produced acceleration of SIT. 5In the present study, peripherally and centrally administered insulin at 2 × 10,6 U/kg produced contrasting effects on SIT, without any hypoglycaemia. However, 2 U/kg insulin accelerated SIT similarly following both s.c. and i.c.v. administration that was associated with hypoglycaemia in healthy animals. [source] Using automatic passenger counter data in bus arrival time predictionJOURNAL OF ADVANCED TRANSPORTATION, Issue 3 2007Mei Chen Artificial neural networks have been used in a variety of prediction models because of their flexibility in modeling complicated systems. Using the automatic passenger counter data collected by New Jersey Transit, a model based on a neural network was developed to predict bus arrival times. Test runs showed that the predicted travel times generated by the models are reasonably close to the actual arrival times. [source] Express guideway transit: A case for further development in transit automationJOURNAL OF ADVANCED TRANSPORTATION, Issue 2 2002Justin Batelaan Safe and reliable coupling and decoupling of cars from a moving train is feasible with further developments in linear motor propulsion and control of transit vehicles. This allows the last car of a train to decouple and stop at a station for a relative long dwell time, before it accelerates and is coupled to a following train. Controlled doors in front and rear of the transit vehicle permit passengers to walk through the train to the car which stops at their destination. A proposed transit system using these features is described and compared to Bombardier's Advanced Rapid Transit. Potential advantages are high schedule speed, uncrowded trains, smaller and more stations, low energy requirements and a smaller vehicle fleet. [source] Structural Solutions to Social Dilemmas: A Field Study on Commuters' Willingness to Fund Improvements in Public Transit,JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 3 2001Jeffrey A. Joireman The present field study examined commuters'(N= 152) willingness to fund improvements in public transit. Consistent with Samuelson's (1993; Samuelson & Messick, 1995) multiattribute evaluation model of structural change in social dilemmas, support for the transit plan was higher when it was perceived to be (a) effective at reducing congestion and pollution, (b) personally beneficial, and (c) fair in terms of taxes and benefits. Also consistent with predictions, these relationships were moderated by individual differences in social value orientation (MClintock, 1968) and the consideration of future consequences (CFC; Strathman, Gleicher, Boninger, & Edwards, 1994). Prosocials responded more to the perceived fairness of the plan, while proselfs responded more to the plan's effectiveness in reducing congestion. Low CFCs responded more to the plan's personal benefits and effectiveness in reducing congestion, while high CFCs responded more to the plan's effectiveness in reducing pollution. [source] Effects of Body Positioning on Swallowing and Esophageal Transit in Healthy DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 4 2009C.M. Bonadio Background: Contrast videofluoroscopy is the imaging technique of choice for evaluating dysphagic dogs. In people, body position alters the outcome of videofluoroscopic assessment of swallowing. Hypothesis/Objective: That esophageal transit in dogs, as measured by a barium esophagram, is not affected by body position. Animals: Healthy dogs (n= 15). Methods: Interventional, experimental study. A restraint device was built to facilitate imaging of dogs in sternal recumbancy. Each dog underwent videofluoroscopy during swallowing of liquid barium and barium-soaked kibble in sternal and lateral recumbancy. Timing of swallowing, pharyngeal constriction ratio, esophageal transit time, and number of esophageal peristaltic waves were compared among body positions. Results: Transit time in the cervical esophagus (cm/s) was significantly delayed when dogs were in lateral recumbency for both liquid (2.58 ± 1.98 versus 7.23 ± 3.11; P= .001) and kibble (4.44 ± 2.02 versus 8.92 ± 4.80; P= .002). In lateral recumbency, 52 ± 22% of liquid and 73 ± 23% of kibble swallows stimulated primary esophageal peristalsis. In sternal recumbency, 77 ± 24% of liquid (P= .01 versus lateral) and 89 ± 16% of kibble (P= .01 versus lateral) swallows stimulated primary esophageal peristalsis. Other variables were not significantly different. Conclusions and Clinical Importance: Lateral body positioning significantly increases cervical esophageal transit time and affects the type of peristaltic wave generated by a swallow. [source] A secreted anti-activator, OspD1, and its chaperone, Spa15, are involved in the control of transcription by the type III secretion apparatus activity in Shigella flexneriMOLECULAR MICROBIOLOGY, Issue 6 2005Claude Parsot Summary Bacteria of Shigella spp. are responsible for shigellosis in humans and use a type III secretion (TTS) system to enter epithelial cells and trigger apoptosis in macrophages. Transit of translocator and effector proteins through the TTS apparatus is activated upon contact of bacteria with host cells. Transcription of ,15 genes encoding effectors is regulated by the TTS apparatus activity and controlled by MxiE, an AraC family activator, and its coactivator IpgC, the chaperone of IpaB and IpaC translocators. Using a genetic screen, we identified ospD1 as a gene whose product negatively controls expression of genes regulated by secretion activity. OspD1 associates with the chaperone Spa15 and the activator MxiE and acts as an anti-activator until it is secreted. The mechanism regulating transcription in response to secretion activity involves an activator (MxiE), an anti-activator (OspD1), a co-anti-activator (Spa15), a coactivator (IpgC) and two anti-coactivators (IpaB and IpaC) whose alternative and mutually exclusive interactions are controlled by the duration of the TTS apparatus activity. [source] Kabul Transit edited by David Edwards, Gregory Whitmore, and Maliha ZulfacarAMERICAN ANTHROPOLOGIST, Issue 1 2010Bill Nichols No abstract is available for this article. [source] Germany in Transit: Nation and Migration 1955-2005 by Deniz Göktürk, David Gramling and Anton Kaes (eds.)NATIONS AND NATIONALISM, Issue 1 2008ELI NATHANS [source] Neoliberalism, Mobility and Cook Islands Men in TransitTHE AUSTRALIAN JOURNAL OF ANTHROPOLOGY, Issue 2 2008Kalissa Alexeyeff From the 1990s, neoliberalism has been vigorously promoted by aid agencies operating in the Cook Islands. The solution to the country's economic problems has been sought in the privatisation of government assets and services and the development of free-market principles. Social Impact Assessment reports of these reforms have included information on their effect on women and children under the heading of ,gender'; men, however, are notably absent as a category of analysis. Building on recent work about men, masculinities and development, this paper begins to address this imbalance by examining how Cook Islands men have been effected by, and how they react to, neoliberalism in a series of gender specific ways. In particular, it explores the relationship between masculinity, class, status, and migration. [source] Induction of CD44 cleavage in articular chondrocytesARTHRITIS & RHEUMATISM, Issue 5 2010Nobunori Takahashi Objective The hyaluronan receptor CD44 provides chondrocytes with a mechanism for sensing and responding to changes in the extracellular matrix. The purpose of this study was to document the fragmentation and loss of CD44 and to determine the likely mechanisms involved. Methods A polyclonal anti-CD44 cytotail antibody was generated to detect CD44 fragmentation by Western blot analysis. Chondrocytes were isolated from human or bovine articular cartilage. Primary articular chondrocytes were treated with interleukin-1, (IL-1,), hyaluronan oligosaccharides, or phorbol myristate acetate or were passaged and subcultured in monolayer to induce dedifferentiation. Conditions that altered the capacity of CD44 to transit into lipid rafts, or pharmacologic inhibitors of metalloproteinase or ,-secretase activity were used to define the mechanism of fragmentation of CD44. Results Chondrocytes from osteoarthritic cartilage exhibited CD44 fragmentation as low molecular mass bands, corresponding to the CD44-EXT and CD44-ICD bands. Following dedifferentiation of chondrocytes or treatment of primary chondrocytes with hyaluronan oligosaccharides, IL-1,, or phorbol myristate acetate, CD44 fragmentation was enhanced. Subsequent culture of the dedifferentiated chondrocytes in 3-dimensional alginate beads rescued the chondrocyte phenotype and diminished the fragmentation of CD44. Fragmentation of CD44 in chondrocytes was blocked in the presence of the metalloproteinase inhibitor GM6001 and the ,-secretase inhibitor DAPT. Conclusion CD44 fragmentation, consistent with a signature pattern reported for sequential metalloproteinase/,-secretase cleavage of CD44, is a common metabolic feature of chondrocytes that have undergone dedifferentiation in vitro and osteoarthritic chondrocytes. Transit of CD44 into lipid rafts may be required for its fragmentation. [source] The end of the beginning for Cassini-Huygens; Transit of Venus observed; appointments and awards; sunlit uplands.ASTRONOMY & GEOPHYSICS, Issue 4 2004Article first published online: 27 JUL 200 Click HERE to view article. [source] Rotation speed and stellar axis inclination from p modes: how CoRoT would see other sunsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2006J. Ballot ABSTRACT In the context of future space-based asteroseismic missions, we have studied the problem of extracting the rotation speed and the rotation-axis inclination of solar-like stars from the expected data. We have focused on slow rotators (at most twice solar rotation speed), first, because they constitute the most difficult case and, secondly, because some of the Convection Rotation and planetary Transits (CoRoT) main targets are expected to have slow rotation rates. Our study of the likelihood function has shown a correlation between the estimates of inclination of the rotation axis i and the rotational splitting ,, of the star. By using the parameters, i and ,,,=,, sin i, we propose and discuss new fitting strategies. Monte Carlo simulations have shown that we can extract a mean splitting and the rotation-axis inclination down to solar rotation rates. However, at the solar rotation rate we are not able to correctly recover the angle i, although we are still able to measure a correct ,,, with a dispersion less than 40 nHz. [source] Tabu Search Strategies for the Public Transportation Network Optimizations with Variable Transit DemandCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 7 2008Wei Fan A multi-objective nonlinear mixed integer model is formulated. Solution methodologies are proposed, which consist of three main components: an initial candidate route set generation procedure (ICRSGP) that generates all feasible routes incorporating practical bus transit industry guidelines; a network analysis procedure (NAP) that decides transit demand matrix, assigns transit trips, determines service frequencies, and computes performance measures; and a Tabu search method (TSM) that combines these two parts, guides the candidate solution generation process, and selects an optimal set of routes from the huge solution space. Comprehensive tests are conducted and sensitivity analyses are performed. Characteristics analyses are undertaken and solution qualities from different algorithms are compared. Numerical results clearly indicate that the preferred TSM outperforms the genetic algorithm used as a benchmark for the optimal bus transit route network design problem without zone demand aggregation. [source] Gastrointestinal motility and the brain-gut axisDIGESTIVE ENDOSCOPY, Issue 2 2003TADASHI ISHIGUCHI The role of the brain-gut axis in gastrointestinal motility is discussed according to the specific organs of the gastrointestinal tract. Not only clinical studies but basic animal research are reviewed. Although the mechanism of functional gut disorders remains to be clarified, recent data suggest that there is evidence that the brain-gut axis has significant effects on gastrointestinal motility. The major role of endoscopy in the diagnosis of functional gastrointestinal disorders is to exclude organic gastrointestinal disorders. In the esophagus, the lower esophageal sphincter and a gamma-aminobutyric acid B mechanism are considered to play important roles in gastroesophageal reflux disease. In the stomach, corticotropin-releasing factor, neuropeptide Y and other substances might be involved in the pathogenesis of non-ulcer dyspepsia. In the small intestine, corticotropin-releasing factor, gamma-aminobutyric acid B and other substances are considered to modulate intestinal transit via central mechanisms. In the colon, it is known that psychiatric factors are related to the onset and clinical course of irritable bowel syndrome. Serotonin, corticotropin-releasing factor, gamma-aminobutyric acid, orphanin FQ and neuropeptide Y have been reported as putative neurotransmitters. More efforts in basic science studies and animal and human studies of physiology of the gastointestinal tract are still required. These efforts will elucidate further mechanisms to clarify the etiology of motility disorders and encourage the investigation of new therapies in this field. [source] The SDF-1/CXCR4 pathway and the development of the cerebellar systemEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2005Tim O. Vilz Abstract Mice deficient for the chemokine receptor CXCR4 show premature translocation of granule cell neuroblasts from their germinal zone into the nascent cerebellum [Y.-R. Zuo et al. (1998)Nature, 393, 595,599]. Here, we used CXCR4-null mice to analyse the early development of cerebellar cortical inhibitory interneurons and pontine neurons which, in the adult, are synaptically integrated with granule cells. Cortical inhibitory interneuronal precursors normally invade the cerebellar anlage of CXCR4-deficient mice, but their dispersal is impeded by dislocated foci of proliferating granule cells, from which they are excluded. This is reminiscent of the strict exclusion of inhibitory interneuronal precursors from the superficial external granule cell layer. As inhibitory interneuronal precursors readily mingle with post-mitotic granule cells both in wild-type and CXCR4-null mice, these findings indicate that the developmentally regulated interactions between granule and inhibitory interneuronal precursors are independent of SDF-1/CXCR4 signalling. In contrast, the transit of pontine neurons from the rhombic lip through the anterior extramural stream to the basilar pons is disrupted in CXCR4-deficient animals. Migrating pontine neurons express CXCR4, and in CXCR4-null animals these cells are found displaced deep into the brainstem. Consequently, nascent pontine nuclei in CXCR4-deficient animals are hypoplastic. Moreover, they fail to express plexin D1, suggesting that SDF-1/CXCR4 signalling may also impinge on axon guidance critical to the orderly formation of granule cell mossy fibre afferents. [source] Red Cell Pulmonary Transit Times Through the Healthy Human LungEXPERIMENTAL PHYSIOLOGY, Issue 2 2003G. S. Zavorsky It has previously been postulated that rapid red cell capillary transit through the human lung plays a role in the mechanism of diffusion limitation in some endurance athletes. Methodological limitations currently prevent researchers from directly measuring pulmonary capillary transit times in humans during exercise; however, first pass radionuclide cardiography allows direct measurement of red blood cell (RBC) transit times through the whole lung at various exercise intensities. We examined the relationship between mean whole lung red cell pulmonary transit times (cardiopulmonary transit times or CPTT) and different levels of flow in 88 healthy humans (76 males, 12 females) from several studies (mean age 31 years). The pooled data suggest that the relationship between CPTT and cardiac index (CI), beginning at rest and progressing through to maximum exercise demonstrates that CPTT reaches its minimum value when CI is about 8.1 l m2 min,1 (2.5-3 times the CI value at rest), and does not significantly change with further increases in CI. Cardiopulmonary blood volume (CPBV) index also does not change significantly until CI reaches 2.5 to 3 times the CI value at rest and then increases roughly linearly after that point. Consequently, the systematic increase in CPBV index with increasing pulmonary blood flow between 8.1 and 20 l m2 min,1 displays an adaptive response of the cardiopulmonary system by augmenting CPBV (and perhaps pulmonary capillary blood volume through distension and recruitment) to offset the reduction in CPTT, as no significant difference in mean CPTT is observed between these levels of flow (P > 0.05). Therefore, these data demonstrate that CPBV does not reach maximum capacity during strenuous or maximum exercise. This does not support the principle of quarter-power allometric scaling for flow when explaining modifications during exercise. Therefore, we speculate that the observed relationships between CPTT, CBPV index and flow may prevent mean CPTT (and perhaps mean pulmonary capillary transit times) from decreasing below the threshold time required for oxygenation. [source] Hydrolysis of acetylthiocoline, o -nitroacetanilide and o- nitrotrifluoroacetanilide by fetal bovine serum acetylcholinesteraseFEBS JOURNAL, Issue 7 2009María F. Montenegro Besides esterase activity, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) hydrolyze o -nitroacetanilides through aryl acylamidase activity. We have reported that BuChE tetramers and monomers of human blood plasma differ in o -nitroacetanilide (ONA) hydrolysis. The homology in quaternary structure and folding of subunits in the prevalent BuChE species () of human plasma and AChE forms of fetal bovine serum prompted us to study the esterase and amidase activities of fetal bovine serum AChE. The kcat/Km values for acetylthiocholine (ATCh), ONA and its trifluoro derivative N -(2-nitrophenyl)-trifluoroacetamide (F-ONA) were 398 × 106 m,1·min,1, 0.8 × 106 m,1·min,1, and 17.5 × 106 m,1·min,1, respectively. The lack of inhibition of amidase activity at high F-ONA concentrations makes it unlikely that there is a role for the peripheral anionic site (PAS) in F-ONA degradation, but the inhibition of ATCh, ONA and F-ONA hydrolysis by the PAS ligand fasciculin-2 points to the transit of o -nitroacetalinides near the PAS on their way to the active site. Sedimentation analysis confirmed substrate hydrolysis by tetrameric 10.9S AChE. As compared with esterase activity, amidase activity was less sensitive to guanidine hydrochloride. This reagent led to the formation of 9.3S tetramers with partially unfolded subunits. Their capacity to hydrolyze ATCh and F-ONA revealed that, despite the conformational change, the active site architecture and functionality of AChE were partially retained. [source] KNQ1, a Kluyveromyces lactis gene encoding a transmembrane protein, may be involved in iron homeostasisFEMS YEAST RESEARCH, Issue 5 2007Emmanuela Marchi Abstract The original purpose of the experiments described in this article was to identify, in the biotechnologically important yeast Kluyveromyces lactis, gene(s) that are potentially involved in oxidative protein folding within the endoplasmic reticulum (ER), which often represents a bottleneck for heterologous protein production. Because treatment with the membrane-permeable reducing agent dithiothreitol inhibits disulfide bond formation and mimics the reducing effect that the normal transit of folding proteins has in the ER environment, the strategy was to search for genes that conferred higher levels of resistance to dithiothreitol when present in multiple copies. We identified a gene (KNQ1) encoding a drug efflux permease for several toxic compounds that in multiple copies conferred increased dithiothreitol resistance. However, the KNQ1 product is not involved in the excretion of dithiothreitol or in recombinant protein secretion. We generated a knq1 null mutant, and showed that both overexpression and deletion of the KNQ1 gene resulted in increased resistance to dithiothreitol. KNQ1 amplification and deletion resulted in enhanced transcription of iron transport genes, suggesting, for the membrane-associated protein Knq1p, a new, unexpected role in iron homeostasis on which dithiothreitol tolerance may depend. [source] Bir1/Cut17 moving from chromosome to spindle upon the loss of cohesion is required for condensation, spindle elongation and repairGENES TO CELLS, Issue 9 2001Jun Morishita Background In mammals, proteins containing BIR domains (IAPs and survivin) are implicated in inhibiting apoptosis and sister chromatid separation. In the nematode, Bir1 is required for a proper localization of aurora kinase, which moves from the mitotic chromosome in metaphase to the spindle midzone in anaphase as a passenger. Fission yeast Bir1/Pbh1 is essential for normal mitosis. Results A temperature sensitive mutant cut17-275 exhibits the defect in condensation and spindle elongation at 36 °C, while securin is degraded. Gene cloning shows that the cut17+ gene is identical to bir1+/pbh1+. At 26 °C, cut17-275 is UV sensitive as the repair of DNA damage is severely compromised. Bir1/Cut17 is a nuclear protein in interphase, which is then required for recruiting condensin to the mitotic nucleus, and concentrates to form a discrete number of dots from prometaphase to metaphase. Once the chromatids are separated, Bir1/Cut17 no longer binds to kinetochores and instead moves to the middle of spindle. Chromatin immunoprecipitation suggested that Bir1/Cut17 associates with the outer repetitious centromere region in metaphase. Following the initiation of anaphase the protein switches from being a chromosomal protein to a spindle protein. This transit is stringently regulated by the state of sister chromatid cohesion proteins Mis4 and Rad21. Ark1, is an aurora kinase homologue whose mitotic distribution is identical to, and under the control of Bir1/Cut17. Conclusions Bir1/Cut17 and Ark1 act as ,passengers' but they may play a main role as a recruitment factor, essential for condensation, spindle elongation and DNA repair. Bir1/Cut17 should have roles both in mitotic and in interphase chromosome. The proper location of Ark1 requires Bir1/Cut17, and the mitotic localization of Bir1/Cut17 requires sister cohesion. [source] Transfer of hydrocarbons from natural seeps to the water column and atmosphereGEOFLUIDS (ELECTRONIC), Issue 2 2002I. R. MacDonald Abstract Results from surface geochemical prospecting, seismic exploration and satellite remote sensing have documented oil and gas seeps in marine basins around the world. Seeps are a dynamic component of the carbon cycle and can be important indicators for economically significant hydrocarbon deposits. The northern Gulf of Mexico contains hundreds of active seeps that can be studied experimentally with the use of submarines and Remotely Operated Vehicles (ROV). Hydrocarbon flux through surface sediments profoundly alters benthic ecology and seafloor geology at seeps. In water depths of 500,2000 m, rapid gas flux results in shallow, metastable deposits of gas hydrate, which reduce sediment porosity and affect seepage rates. This paper details the processes that occur during the final, brief transition , as oil and gas escape from the seafloor, rise through the water and dissolve, are consumed by microbial processes, or disperse into the atmosphere. The geology of the upper sediment column determines whether discharge is rapid and episodic, as occurs in mud volcanoes, or more gradual and steady, as occurs where the seep orifice is plugged with gas hydrate. In both cases, seep oil and gas appear to rise through the water in close proximity instead of separating. Chemical alteration of the oil is relatively minor during transit through the water column, but once at the sea surface its more volatile components rapidly evaporate. Gas bubbles rapidly dissolve as they rise, although observations suggest that oil coatings on the bubbles inhibit dissolution. At the sea surface, the floating oil forms slicks, detectable by remote sensing, whose origins are laterally within ,1000 m of the seafloor vent. This contradicts the much larger distance predicted if oil drops rise through a 500 m water column at an expected rate of ,0.01 m s,1 while subjected to lateral currents of ,0.2 m s,1 or greater. It indicates that oil rises with the gas bubbles at speeds of ,0.15 m s,1 all the way to the surface. [source] MOVING VIOLATIONS: DATA PRIVACY IN PUBLIC TRANSITGEOGRAPHICAL REVIEW, Issue 3 2007NANCY J. OBERMEYER ABSTRACT. This article draws from the foundation provided by the ongoing debate about geosurveillance to frame a discussion of the use of tracking technologies in public transit. Specifically, it uses the case of public transit to illustrate the uncomfortable debate about compromises that come with increased surveillance to enhance public safety and security. The article begins with a discussion of the evolution of the debate about geosurveillance, casting the use of surveillance technologies in public transit within this framework. Next, it describes and discusses the implementation of automatic vehicle locators and closed-circuit television in public transit. The following sections focus on the risks to individual privacy that accompany implementation of these technologies, then describe an unusual effort to draw attention to the prevalence of increased surveillance in public spaces in an effort to expose the risks. The article concludes by making the case that public transit is a place where surveillance provides clear benefits but where the humans who review the surveillance data must interpret and use them responsibly to minimize the risks to individual privacy. [source] Geodetic observations of ice flow velocities over the southern part of subglacial Lake Vostok, Antarctica, and their glaciological implicationsGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2006Jens Wendt SUMMARY In the austral summer seasons 2001/02 and 2002/03, Global Positioning System (GPS) data were collected in the vicinity of Vostok Station to determine ice flow velocities over Lake Vostok. Ten GPS sites are located within a radius of 30 km around Vostok Station on floating ice as well as on grounded ice to the east and to the west of the lake. Additionally, a local deformation network around the ice core drilling site 5G-1 was installed. The derived ice flow velocity for Vostok Station is 2.00 m a,1± 0.01 m a,1. Along the flowline of Vostok Station an extension rate of about 10,5 a,1 (equivalent to 1 cm km,1 a,1) was determined. This significant velocity gradient results in a new estimate of 28 700 years for the transit time of an ice particle along the Vostok flowline from the bedrock ridge in the southwest of the lake to the eastern shoreline. With these lower velocities compared to earlier studies and, hence, larger transit times the basal accretion rate is estimated to be 4 mm a,1 along a portion of the Vostok flowline. An assessment of the local accretion rate at Vostok Station using the observed geodetic quantities yields an accretion rate in the same order of magnitude. Furthermore, the comparison of our geodetic observations with results inferred from ice-penetrating radar data indicates that the ice flow may not have changed significantly for several thousand years. [source] A Parallel PCG Solver for MODFLOWGROUND WATER, Issue 6 2009Yanhui Dong In order to simulate large-scale ground water flow problems more efficiently with MODFLOW, the OpenMP programming paradigm was used to parallelize the preconditioned conjugate-gradient (PCG) solver with in this study. Incremental parallelization, the significant advantage supported by OpenMP on a shared-memory computer, made the solver transit to a parallel program smoothly one block of code at a time. The parallel PCG solver, suitable for both MODFLOW-2000 and MODFLOW-2005, is verified using an 8-processor computer. Both the impact of compilers and different model domain sizes were considered in the numerical experiments. Based on the timing results, execution times using the parallel PCG solver are typically about 1.40 to 5.31 times faster than those using the serial one. In addition, the simulation results are the exact same as the original PCG solver, because the majority of serial codes were not changed. It is worth noting that this parallelizing approach reduces cost in terms of software maintenance because only a single source PCG solver code needs to be maintained in the MODFLOW source tree. [source] Helicobacter Hypothesis for Idiopathic Parkinsonism: Before and BeyondHELICOBACTER, Issue 5 2008R. John Dobbs Abstract We challenge the concept of idiopathic parkinsonism (IP) as inevitably progressive neurodegeneration, proposing a natural history of sequential microbial insults with predisposing host response. Proof-of-principle that infection can contribute to IP was provided by case studies and a placebo-controlled efficacy study of Helicobacter eradication. "Malignant" IP appears converted to "benign", but marked deterioration accompanies failure. Similar benefit on brady/hypokinesia from eradicating "low-density" infection favors autoimmunity. Although a minority of UK probands are urea breath test positive for Helicobacter, the predicted probability of having the parkinsonian label depends on the serum H. pylori antibody profile, with clinically relevant gradients between this "discriminant index" and disease burden and progression. In IP, H. pylori antibodies discriminate for persistently abnormal bowel function, and specific abnormal duodenal enterocyte mitochondrial morphology is described in relation to H. pylori infection. Slow intestinal transit manifests as constipation from the prodrome. Diarrhea may flag secondary small-intestinal bacterial overgrowth. This, coupled with genetically determined intense inflammatory response, might explain evolution from brady/hypokinetic to rigidity-predominant parkinsonism. [source] Methodology and Transport Medium for Collection of Helicobacter pylori on a String Test in Remote LocationsHELICOBACTER, Issue 6 2005Helen M. Windsor ABSTRACT Background.,Helicobacter pylori can be isolated from patients using the string test but contaminating oral and nasopharyngeal microflora need to be suppressed by rapid plating out onto selective culture media. Recently, use of this diagnostic method was enhanced by using a novel transport medium to collect specimens from subjects in a remote Australian clinic over 1300 km from the laboratory. Methods., Retrieved string tests were transported to the laboratory in chilled polystyrene boxes in 5 ml screw-cap bottles with 3 ml of a brain heart infusion broth plus antibiotics. These were 20 g/ml vancomycin, 10 g/ml trimethoprim, 10 g/ml cefsulodin, and 10 g/ml amphotericin B. A comparison was made between subjects who gargled with a chlorhexidine mouthwash before swallowing the string test and those who did not. Results., Forty-five urea breath test-positive subjects were tested and H. pylori was isolated from 34 of them. Successful culture was achieved from string tests that were in transit for up to 29 hours and where the maximum temperature in the transport box was 14 °C. The additional use of a mouthwash had a marked effect on the isolation rate. H. pylori was cultured from 75% of subjects who gargled but only from 39% who did not. Conclusions., This methodology and transport medium can broaden the use of the string test to more remote geographic areas where endoscopy is not feasible so that H. pylori isolates may still be obtained for diagnostic and epidemiologic studies. The value of this promising methodology of collection and transport should be assessed in a controlled study. [source] Genetic and phenotypic analysis of B-cell post-transplant lymphoproliferative disorders provides insights into disease biologyHEMATOLOGICAL ONCOLOGY, Issue 4 2008Efsevia Vakiani Abstract B-cell post-transplant lymphoproliferative disorders (PTLD) are classified as early lesions, polymorphic lymphomas (P-PTLD) and monomorphic lymphomas (M-PTLD). These morphologic categories are thought to reflect a biologic continuum, although supporting genetic data are lacking. To gain better insights into PTLD pathogenesis, we characterized the phenotypes, immunoglobulin (Ig) gene alterations and non-Ig gene (BCL6, RhoH/TTF, c-MYC, PAX5, CIITA, BCL7A, PIM1) mutations of 21 PTLD, including an IM-like lesion, 8 P-PTLD and 12 M-PTLD. Gene expression profile analysis was also performed in 12 cases. All PTLD with clonal Ig rearrangements showed evidence of germinal centre (GC) transit based on the analysis of Ig and BCL6 gene mutations, and 74% had a non-GC phenotype (BCL6,±,MUM1+). Although surface Ig abnormalities were seen in 6/19 (32%) PTLD, only three showed ,crippling' Ig mutations indicating other etiologies for loss of the B-cell receptor. Aberrant somatic hypermutation (ASHM) was almost exclusively observed in M-PTLD (8/12 vs. 1/8 P-PTLD) and all three recurrent cases analysed showed additional mutations in genes targeted by ASHM. Gene expression analysis showed distinct clustering of PTLD compared to B-cell non-Hodgkin lymphomas (B-NHL) without segregation of P-PTLD from non-GC M-PTLD or EBV+ from EBV, PTLD. The gene expression pattern of PTLD appeared more related to that of memory and activated B-cells. Together, our results suggest that PTLD represent a distinct type of B-NHL deriving from an antigen experienced B-cell, whose evolution is associated with accrual of genetic lesions. Copyright © 2008 John Wiley & Sons, Ltd. [source] Secretin activation of the apical Na+ -dependent bile acid transporter is associated with cholehepatic shunting in rats,HEPATOLOGY, Issue 5 2005Gianfranco Alpini The role of the cholangiocyte apical Na+ -dependent bile acid transporter (ASBT) in bile formation is unknown. Bile acid absorption by bile ducts results in cholehepatic shunting, a pathway that amplifies the canalicular osmotic effects of bile acids. We tested in isolated cholangiocytes if secretin enhances ASBT translocation to the apical membrane from latent preexisting intracellular stores. In vivo, in bile duct,ligated rats, we tested if increased ASBT activity (induced by secretin pretreatment) results in cholehepatic shunting of bile acids. We determined the increment in taurocholate-dependent bile flow and biliary lipid secretion and taurocholate (TC) biliary transit time during high ASBT activity. Secretin stimulated colchicine-sensitive ASBT translocation to the cholangiocyte plasma membrane and 3H-TC uptake in purified cholangiocytes. Consistent with increased ASBT promoting cholehepatic shunting, with secretin pretreatment, we found TC induced greater-than-expected biliary lipid secretion and bile flow and there was a prolongation of the TC biliary transit time. Colchicine ablated secretin pretreatment-dependent bile acid,induced choleresis, increased biliary lipid secretion, and the prolongation of the TC biliary transit. In conclusion, secretin stimulates cholehepatic shunting of conjugated bile acids and is associated with increased cholangiocyte apical membrane ASBT. Bile acid transport by cholangiocyte ASBT can contribute to hepatobiliary secretion in vivo. (HEPATOLOGY 2005.) [source] Effect of propranolol on the factors promoting bacterial translocation in cirrhotic rats with ascitesHEPATOLOGY, Issue 1 2000María Pérez-Paramo Bacterial translocation appears to be an important mechanism in the pathogenesis of spontaneous infections in cirrhosis. Cirrhotic patients are commonly treated with ,-adrenoceptor blockers, but the impact of this treatment in the factors promoting bacterial translocation has not been investigated. This study was aimed at investigating in cirrhotic rats with ascites the effect of propranolol on intestinal bacterial load, transit, and permeability of the bowel and on the rate of bacterial translocation. Bacterial translocation to mesenteric lymph nodes and intestinal bacterial overgrowth, permeability (urinary excretion of 99mTc-diethylenetriaminepentaacetic acid [99mTc-DTPA]), and transit (geometric center ratio of 51Cr) were assessed in 29 rats with carbon tetrachloride (CCl4 ) cirrhosis and 20 controls. These variables were then measured in 12 placebo- and in 13 propranolol-treated ascitic cirrhotic rats. Bacterial translocation was present in 48% of the cirrhotic rats and in none of the controls. Cirrhotic rats with intestinal bacterial overgrowth had a significantly higher rate of translocation and slower intestinal transit than those without it. Among the 15 rats with overgrowth and a 99mTc-DTPA excretion greater than 10%, 15 had translocation and 2 had bacterial peritonitis. Only 1 of the 14 rats with either intestinal overgrowth or a 99mTc-DTPA excretion greater than 10% presented translocation. Compared with the placebo group, propranolol-treated animals had significantly lower portal pressure, faster intestinal transit, and lower rates of bacterial overgrowth and translocation. In ascitic cirrhotic rats, bacterial translocation results from intestinal overgrowth and severe damage to gut permeability. In this setting, intestinal overgrowth is associated with intestinal hypomotility. Propranolol accelerates the intestinal transit, decreasing the rates of bacterial overgrowth and translocation. [source] Autophagy and adaptive immunityIMMUNOLOGY, Issue 1 2010Victoria L. Crotzer Summary Autophagy plays an important role in maintaining intracellular homeostasis by promoting the transit of cytoplasmic material, such as proteins, organelles and pathogens, for degradation within acidic organelles. Yet, in immune cells, autophagy pathways serve an additional role in facilitating intracellular surveillance for pathogens and changes in self. Autophagy pathways can modulate key steps in the development of innate and adaptive immunity. In terms of adaptive immunity, autophagy regulates the development and survival of lymphocytes as well as the modulation of antigen processing and presentation. Specialized forms of autophagy may be induced by some viral pathogens, providing a novel route for major histocompatibility complex (MHC) class I antigen presentation and enhanced CD8+ T-cell responses. Autophagy induction in target cells also increases their potential to serve as immunogens for dendritic cell cross-presentation to CD8+ T cells. The requirement for autophagy in MHC class II presentation of cytoplasmic and nuclear antigens is well established, yet recent studies also point to a critical role for autophagy in modulating CD4+ T-cell responses to phagocytosed pathogens. Autophagy pathways can also modulate the selection and survival of some CD4+ T cells in the thymus. However, much still remains to be learned mechanistically with respect to how autophagy and autophagy-linked genes regulate pathogen recognition and antigen presentation, as well as the development and survival of immune cells. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||