bluuebunny/crossref_metadata_2025 huggingface dataset:
Planktonic linkages among marine protected areas on the south Florida and southeast United States continental shelves
Authors: Hare Jonathan A , Walsh Harvey J
Published: September 2007

One proposed benefit of marine protected areas (MPAs) is increased larval export, potentially increasing recruitment in unprotected areas. Because most marine species have planktonic larvae, information regarding planktonic transport is needed to evaluate the benefit of larval export. We used satellite-tracked drifters to define planktonic transport routes and rates from three MPAs along the south Florida and southeast United States (US) continental shelves. Drifter tracks indicated both long-distance transport and local retention. A probability model was developed based on drifter releases. The region was broken into zones; zone-specific residence times and movements between zones were defined from the drifter tracks. Transport out of the region in association with the Loop Current – Florida Current – Gulf Stream was the most frequently observed outcome, yet retention was high in the lower Florida Keys and on the Georgia shelf. From the model results, long-distance planktonic transport and local retention are the endpoints of a continuum rather than a dichotomy. Further, the outcome of planktonic transport is spatially heterogeneous with some regions exhibiting more retention and others exhibiting more export. The spatial aspects of planktonic transport described here should be considered in designing MPAs with fishery management objectives in the south Florida and southeast US shelf ecosystems.
The small domain of cytochromeffrom the psychrophileChlamydomonas raudensisUWO 241 modulates the apparent molecular mass and decreases the accumulation of cytochromefin the mesophileChlamydomonas reinhardtii
Authors: Gudynaite-Savitch Loreta , Loiselay Christelle , Savitch Leonid V. , Simmonds John , Kohalmi Susanne E. , Choquet Yves , Hüner Norman P.A.
Published: September 2007

Cytochrome f from the psychrophile Chlamydomonas raudensis UWO 241 has a lower thermostability of its c-type heme and an apparent molecular mass that is 7 kDa lower than that of the model mesophilic green alga Chlamydomonas reinhardtii. We combined chloroplast transformation, site-directed mutagensis, and the creation of chimeric fusion constructs to assess the contribution of specific domains and (or) amino acids residues to the structure, stability, and accumulation of cytochrome f, as well as its function in photosynthetic intersystem electron transport. We demonstrate that differences in the amino acid sequence of the small domain and specific charged amino acids in the large domain of cytochrome f alter the physical properties of this protein but do not affect either the thermostability of the c-type heme, the apparent half-life of cytochrome f in the presence of the chloroplastic protein synthesis inhibitor chloramphenicol, or the capacity for photosynthetic intersystem electron transport, measured as e–/P700. However, pulse-labeling with [14C]acetate, combined with immunoblotting, indicated that the negative autoregulation of cytochrome f accumulation observed in mesophilic C. reinhardtii transformed with chimeric constructs from the psychrophile was likely the result of the defective association of the chimeric forms of cytochrome f with the other subunits of the cytochrome b6/f complex native to the C. reinhardtii wild type. These results are discussed in terms of the unique fatty acid composition of the thylakoid membranes of C. raudensis UWO 241 adapted to cold environments.
Reduction of coronary flow reserve in patients with increased aortic stiffness
Authors: Nemes Attila , Forster Tamás , Csanády Miklós
Published: September 2007

Aortic stiffness is thought to affect coronary blood flow, but little is known about its influence on coronary flow reserve (CFR). The objective of the present study was to investigate the relationship between aortic stiffness and CFR in matched patients with and without increased aortic stiffness. Stress transoesophageal echocardiography (TEE) as the CFR measurement and coronary angiography were performed in all cases. Increased aortic stiffness was defined if elastic modulus Ep > 680 mmHg. The following patient populations free of coronary artery disease were compared: 36 subjects with normal aortic distensibility and 19 age-, sex-, and risk factor-matched patients with increased aortic stiffness. CFR was significantly reduced in patients with increased aortic stiffness as compared with cases with normal aortic distensibility (2.64 ± 1.16 vs. 2.12 ± 0.58, p <0.01). Hyperaemic diastolic flow velocities were reduced in patients with increased aortic stiffness (129.5 ± 36.6 cm/s vs. 102.1 ± 39.8 cm/s, p <0.05). Negative correlations were found between Ep and hyperaemic diastolic coronary flow velocity (r = –0.41, p < 0.01) and CFR (r = –0.21, p < 0.05). CFR is reduced in patients with increased aortic stiffness and negative correlations exist between these functional parameters.
Relation of B-type natriuretic peptide to left ventricular wall stress as assessed by cardiac magnetic resonance imaging in patients with dilated cardiomyopathy
Authors: Alter P. , Rupp H. , Rominger M.B. , Vollrath A. , Czerny F. , Klose K.J. , Maisch B.
Published: September 2007

Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.
SERVICE BUSINESS PLANNING TOWARDS SHARED SERVICE ROADMAPPING — AN APPLICATION TO RF-ID USING SERVICE IN THE RESEARCH ACTIVITIES OF A JAPANESE INDUSTRIAL ASSOCIATION
Authors: NAKAMURA KOTARO , KAMEOKA AKIO
Published: September 2007

A common business conceptual framework is indispensable for achieving the necessary level of collaboration among interlinked business players for planning the timeframe of modern multi-layered technology-intensive services. This paper proposes a service conceptual framework using a hierarchical classification with five needs levels based on Maslow's needs theory and three customer segments. This framework was used as a basis for wide intra-industry collaboration towards performing the roadmappings to be shared for services using RF identification technology. Action research demonstrated the framework's viability for enhancing the intellectual productivity of an interdisciplinary team of collaborating business planners and engineers.
EDITORIAL
Authors: DAIM TUGRUL U. , KOCAOGLU DUNDAR F. , ANDERSON TIMOTHY R.
Published: September 2007

We present a series of two special issues with selected papers from PICMET (Portland International Center for Management of Engineering and Technology) conferences held in 2005 and 2006. These issues focus on the path of emerging technologies from planning phase into innovation phase. This issue is the first of the series and focuses on the earlier part of the path. Its theme is "Strategic Management of Technological Innovation".
The geological significance of radiometric age studies on volcanic and hypabyssal rocks
Authors: Fitch F. J. , Miller J. A.
Published: September 2007

Volcanic and minor intrusive igneous rocks often have more closely defined geological ages than rocks of the plutonic association. Isotopic ages from these rocks are thus important in geochronology. Isotope loss and other factors often result in low ages being obtained, rather than the true age of primary crystallization of an igneous rock. In favourable circumstances, however, the date of a subsequent cleavage, metamorphism, or mineralizing event can be determined. Detailed geological and petrological analysis are essential if the isotopic data are to be correctly interpreted.

A general review of published work on bentonites, tuffs, lavas, and related sub-volcanic intrusions reveals the potentialities and limitations of age studies on this category of rocks. Young volcanic and the unfolded eruptive rocks of post-tectonic environments and of the stable zones of ancient shields provide the best material for initial age studies. The significance of isotopic age studies on basic igneous rocks in the dating of orogenic and mineralizing events is discussed. Determinations of the age of certain Caledonian and Variscan events in Britain are quoted to illustrate the methods used.
The Triassic period
Authors: Tozer Edward Timothy
Published: September 2007

Little information is available that can be used with confidence to construct a Triassic time-scale. The base of the system is variously dated in the range 220 to 238 m.y.; the age of the boundary with the Jurassic is also uncertain, but may be placed at about 190 to 200 m.y Apart from a Russian determination giving a minimum age of 200 m.y. for the Middle Triassic, the only radiometric data available are for the Upper Triassic.
The Permian period
Authors: Smith Denys Barker
Published: September 2007

Twelve rocks for which calculated isotopic ages are mutually consistent and for which there is some biostratigraphic control have been used in the construction of a Permian time-scale. On the evidence of these rocks it is suggested that the Permian period lasted from about 280 m.y to about 225 m.y. ago, with the Lower Permian–Upper Permian transition at about 240 m.y. Ages are also suggested for the remaining intra-Permian stage boundaries.
Gas Exploration and Reserves in Europe
Authors: Makourine A.
Published: September 2007

This Paper will deal with two subjects:

(1)

Natural gas reserves and resources in Europe.

(2)

Exploration for natural gas in Europe.

The first part contains statistical data on natural gas reserves and resources in Europe with certain analyses of the factors affecting their estimation, and comparability of classifications used for the assessment of gas reserves and resources. The seond part describes the methods of gas exploration currently used.

The paper is based on official information supplied by governments—members of the E.C.E., and in particular those participating in the work of the European Group of Experts on Natural Gas Resources of the Committee on Gas.
A Review of Geochemical Data Related to the Northwest European Gas Province
Authors: Barnard P. C. , Cooper B. S.
Published: September 2007

The Northwest European Gas Province has a long and complex history of episodes of subsidence, uplift, salt intrusion and vulcanicity; the province contains large reserves of gas, produced principally from Permian sandstones and generally believed to have been sourced from the Late Carboniferous Coal Measures. Gas generation has occurred when periods of burial from the Triassic onwards have caused vitrinite reflectivity of coal-bearing sediments to exceed 1% and the composition of the gas is shown to be related to the degree of maturity of the source rocks. A reconstruction of the subsidence history of the Cleveland Basin illustrates the development of maturation in the underlying Carboniferous section and is used to extrapolate the recent history of the Cleveland and Sole Pit Basins.
North Sea petroleum exploration
Authors: Brennand T. P.
Published: September 2007

After some twenty years of exploration for oil and gas, the North Sea province has emerged as the most important hydrocarbon province of Western Europe. The recoverable reserves to date discovered in the offshore area are of the order of 25 × 10
9
bbls of oil and condensate, and 100 × 10
12
scf of gas.

A summary review of the history of North Sea exploration and the development of the main ‘plays’ is treated in three periods and followed by a synopsis of the complex North Sea basin evolution and sedimentary fill characteristics. Structural style and reservoir development of the hydrocarbon traps is considered in conjunction with their timely sourcing by the relevant organic-rich sediments.

In conclusion, a speculative view is given on the future of exploration in an area where the most obvious plays have been extensively explored.
Geochemistry of Porosity Enhancement and Reduction in Clastic Sediments
Authors: Curtis C. D.
Published: September 2007

The diagenetic history of many reservoir sandstones appears to be divisible into three stages. The first includes destruction of primary porosity, the second porosity enhancement by chemical leaching, and the third a return to loss by cementation and recrystallisation. In an attempt to account for the solution transport necessarily involved, the several types of water-rock interaction that take place during burial of clastic sediment sequences are reviewed. It is concluded that kinetic factors play an important role: some reactions are spontaneous and fast, others are dependent on ‘initiating’ reactions and are slower. ‘Initiating’ reactions modify pore water composition drastically and are thought to be mainly redox or acid-generating reactions. They take place mostly in mudrocks which contain much more unstable material than sandstones.

Comparisons between mudrock and sandstone diagenetic patterns lend support to previous suggestions that much diagenetic alteration in sandstones is affected by pore waters (and solutes) originating in mudrocks. Aluminium is thought to be mobile under these conditions. A brief consideration of mineral/water reactions in soils leads to the view that pore waters derived directly from meteoric water are unlikely to be effective agents for leaching at depth.
Organic Geochemistry and Basin Modelling — Important Tools in Petroleum Exploration
Authors: Welte D. H. , Yükler M. A. , Radke M. , Leythaeuser D. , Mann U. , Ritter U.
Published: September 2007

Application of organic geochemistry in exploration has drastically changed from a ‘post-mortem science’ to a widely accepted tool. Due to progress in the development of new analytical techniques and interpretative concepts, application of organic geochemistry has become more rapid and also capable of solving more specific problems. Common applications include recognition of source rocks and of re-distribution of hydrocarbons, evaluation of maturity and of hydrocarbon potential and oil-oil and oil-source rock correlation.

At present it is possible to make quantitative predictions on the hydrocarbon potential of an area during the initial stages of exploration. The key for this approach is the combination of organic geochemistry and a predictive geological basin model. Organic geochemical well-profiles and three-dimensional plots are now often used as standard equipment for exploration planning and subsequent exploration activities. The purpose of this paper is to describe the concept of fast, geochemical screening techniques, followed by more-detailed, organic geochemical analyses. In addition, the principles of a predictive, geological basin analysis are given.
Identification of Amorphous Sedimentary Organic Matter by Transmitted Light Microscopy
Authors: Batten D. J.
Published: September 2007

The petroleum source potential of sedimentary rocks often depends to a considerable degree on the quantity and composition of the amorphous organic matter they contain, but hitherto few microscopists have attempted to categorize it. Its origins may be determined from physical characters, although commonly indirect evidence provided by sedimentological and other palaeontological data also has to be taken into account. Thus, I prefer to use terms which do not imply affinities with either land or aquatic plants to describe it. Words such as fibrous, membraneous, pellicular, spongy, granular, flakey, aggregated, finely disseminated and sub-colloidal are applied herein to the variety of amorphous substances which are discussed and illustrated. My aim is at future improvement in correlation between palynofacies and hydrocarbon yield. Many of the samples on which the paper is based are from the northwest European area.
Geological Information from Hydrocarbon Exploration on the United Kingdom Continental Shelf
Authors: Brooks J. R. V.
Published: September 2007

The purpose of this paper is to describe what geological and geophysical information is publicly available from the results of exploration for hydrocarbons on the United Kingdom Continental Shelf (UKCS), to note where it may be obtained, and how to obtain access to it. Both offshore and onshore data are released. A folder is available containing catalogues of all the hydrocarbon-related data and of all information published as a result of Department of Energy-funded work.
Exhumation of the Sanbagawa blueschist belt, SW Japan, by lateral flow and extrusion: evidence from structural kinematics and retrograde
P-T-t
paths
Authors: Wintsch R. P. , Byrne T. , Toriumi M.
Published: September 2007

The correlation in time of a pervasive, nearly strike-parallel, retrograde stretching lineation in the Sanbagawa blueschists with a nearly down-dip, prograde lineation in the structurally underlying Shimanto belt suggests that the oblique accretion and underplating of this belt was at least in part responsible for the longitudinal exhumation of the blueschists. A series of sub-horizontal collinear overgrowths of alkali amphiboles on cores of riebeckite in radiolarian cherts of the Sanbagawa belt, western Shikoku, Japan, indicate essentially continuous retrograde crystallization and extension during nearly strike-parallel exhumation. Needles of magnesio-riebeckite are progressively overgrown by beards or infillings of magnesio-riebeckite, winchite, actinolite, and finally quartz. The Na/(Na + Ca) compositions of overgrowths over many grains show a continuous range from >0.95 to <0.2. We interpret this to reflect continuously decreasing metamorphic conditions from an inferred
c.
10 to
c.
4 kbar (
c.
35-15 km), and from
c.
550°C to <300°C during continuous deformation of these metacherts. Published thermochronological data in related and correlative rocks show that this cooling occurred from mid-Cretaceous to Early Eocene time. Structural and geochronological studies of rocks of the northern Shimanto Belt show that they were accreted to southwest Japan by north-directed underthrusting contemporaneously with exhumation of the Sanbagawa belt. We propose that the retrograde metamorphic fabrics of the Sanbagawa belt developed as these initially high-pressure rocks were exhumed and laterally extruded to the east (present coordinates) during oblique, north-directed underthrusting of the Izanagi (or an equivalent) plate and its thick sedimentary cover (i.e. the Shimanto belt).
New insight into the dynamic development of the Southern Alps, New Zealand, from detailed thermochronological investigation of the Mataketake Range pegmatites
Authors: Batt Geoffrey E. , Kohn Barry P. , Braun Jean , McDougall Ian , Ireland Trevor R.
Published: September 2007

The Southern Alps are an actively developing mountain range resulting from continuing oblique continent-continent collision between the Australian and Pacific plates through the South Island of New Zealand. The thermal histories of five granite pegmatites from the Mataketake Range in the southwest of this orogen are revealed here by U-Pb dating of zircon, K-Ar,
40
Ar-
39
Ar and Rb-Sr dating of muscovite, biotite and alkali feldspar, and fission-track dating of apatite and zircon. The constraint of these thermal histories, and in particular the high thermal resolution gained from analysis of K-feldspar by the
40
Ar-
39
Ar dating method, offers a novel insight into the dynamic evolution of the Southern Alps. The pegmatites were probably formed by localized anatectic partial melting at temperatures of 620–680°C between 67 and 82 Ma. Other than initial cooling to the ambient temperature of the host schist following intrusion (estimated at
c.
500°C), these bodies share an apparently uniform thermochronological record, and this thermal history is thus largely indicative of cooling during local exhumation. Between 10 and 5 Ma, the Mataketake Range area cooled from
c.
350 to 260°C, at a rate of 18°C Ma
−1
. This corresponds to unroofing at between 0.8 and 1 km Ma
−1
during this interval, and is probably a reflection of the inferred early history of the Australian-Pacific plate boundary through the South Island of New Zealand as a dominantly strike-slip feature. A reduction in cooling rate at 5 Ma, immediately followed by an episode of extremely rapid cooling at
c.
350°C Ma
−1
marks the initiation of rapid exhumation and the development of the perturbed geothermal structure of the modern Southern Alps. This supports suggestions that the present tectonic regime of the orogen developed in a single episode of tectonic reorganization 5 Ma ago.
Compensatory membrane expression of the V-ATPase B2 subunit isoform in renal medullary intercalated cells of B1-deficient mice
Authors: Păunescu Teodor G. , Russo Leileata M. , Da Silva Nicolas , Kovacikova Jana , Mohebbi Nilufar , Van Hoek Alfred N. , McKee Mary , Wagner Carsten A. , Breton Sylvie , Brown Dennis
Published: September 2007

Mice deficient in the ATP6V1B1 (“B1”) subunit of the vacuolar proton-pumping ATPase (V-ATPase) maintain body acid-base homeostasis under normal conditions, but not when exposed to an acid load. Here, compensatory mechanisms involving the alternate ATP6V1B2 (“B2”) isoform were examined to explain the persistence of baseline pH regulation in these animals. By immunocytochemistry, the mean pixel intensity of apical B2 immunostaining in medullary A intercalated cells (A-ICs) was twofold greater in B1−/− mice than in B1+/+ animals, and B2 was colocalized with other V-ATPase subunits. No significant upregulation of B2 mRNA or protein expression was detected in B1−/− mice compared with wild-type controls. We conclude that increased apical B2 staining is due to relocalization of B2-containing V-ATPase complexes from the cytosol to the plasma membrane. Recycling of B2-containing holoenzymes between these domains was confirmed by the intracellular accumulation of B1-deficient V-ATPases in response to the microtubule-disrupting drug colchicine. V-ATPase membrane expression is further supported by the presence of “rod-shaped” intramembranous particles seen by freeze fracture microscopy in apical membranes of normal and B1-deficient A-ICs. Intracellular pH recovery assays show that significant (28–40% of normal) V-ATPase function is preserved in medullary ICs from B1−/− mice. We conclude that the activity of apical B2-containing V-ATPase holoenzymes in A-ICs is sufficient to maintain baseline acid-base homeostasis in B1-deficient mice. However, our results show no increase in cell surface V-ATPase activity in response to metabolic acidosis in ICs from these animals, consistent with their inability to appropriately acidify their urine under these conditions.
Movement Planning With Probabilistic Target Information
Authors: Hudson Todd E. , Maloney Laurence T. , Landy Michael S.
Published: September 2007

We examined how subjects plan speeded reaching movements when the precise target of the movement is not known at movement onset. Before each reach, subjects were given only a probability distribution on possible target positions. Only after completing part of the movement did the actual target appear. In separate experiments we varied the location of the mode and the scale of the prior distribution for possible targets. In both cases we found that subjects made use of prior probability information when planning reaches. We also devised two tests (Composite Benefit and Row Dominance tests) to determine whether subjects’ performance met necessary conditions for optimality (defined as maximizing expected gain). We could not reject the hypothesis of optimality in the experiment where we varied the mode of the prior, but departures from optimality were found in response to changes in the scale of prior distributions.
Intrinsic Excitability of Cholinergic Neurons in the Rat Parabigeminal Nucleus
Authors: Goddard C. Alex , Knudsen Eric I. , Huguenard John R.
Published: September 2007

Cholinergic neurons in the parabigeminal nucleus of the rat midbrain were studied in an acute slice preparation. Spontaneous, regular action potentials were observed both with cell-attached patch recordings as well as with whole cell current-clamp recordings. The spontaneous activity of parabigeminal nucleus (PBN) neurons was not due to synaptic input as it persisted in the presence of the pan-ionotropic excitatory neurotransmitter receptor blocker, kynurenic acid, and the cholinergic blockers dihydro-beta-erythroidine (DHβE) and atropine. This result suggests the existence of intrinsic currents that enable spontaneous activity. In voltage-clamp recordings, IH and IA currents were observed in most PBN neurons. IA had voltage-dependent features that would permit it to contribute to spontaneous firing. In contrast, IH was significantly activated at membrane potentials lower than the trough of the spike afterhyperpolarization, suggesting that IH does not contribute to spontaneous firing of PBN neurons. Consistent with this interpretation, application of 25 μM ZD-7288, which blocked IH, did not affect the rate of spontaneous firing in PBN neurons. Counterparts to IA and IH were observed in current-clamp recordings: IA was reflected as a slow voltage ramp observed between action potentials and on release from hyperpolarization, and IH was reflected as a depolarizing sag often accompanied by rebound spikes in response to hyperpolarizing current injections. In response to depolarizing current injections, PBN neurons fired at high frequencies, with relatively little accommodation. Ultimately, the spontaneous activity in PBN neurons could be used to modulate cholinergic drive in the superior colliculus in either positive or negative directions.
Photoluminescent Spectra of Nd3+Codoped CaAl2O4:Eu2+Blue Phosphor
Authors: Ryu Hojin , Bartwal K. S.
Published: September 2007

Phosphor material CaAl2O4:Eu2+codoped with varying concentrations ofNd3+was prepared by solid-state reaction method. Prepared materials with 1 mol%Eu2+andNd3+(0.5 to 5 mol%) show high brightness and long persistent luminescence. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Photoluminescence excitation and emission spectra were taken to investigate the luminescence characteristics. Broadband UV excited luminescence of the CaAl2O4:Eu2+,Nd3+was observed in the blue region (λmax= 440 nm) due to transitions from4f 6 5d1to the4f 7configuration of theEu2+ion. TheNd3+ion doping in the phosphor generates deep traps which result in long afterglow phosphorescence.
Synthesis, Spectroscopic, and Antimicrobial Studies on Bivalent Nickel and Copper Complexes of Bis(thiosemicrbazone)
Authors: Chandra Sulekh , Raizada Smriti , Tyagi Monika , Gautam Archana
Published: September 2007

A series of metal complexes of Cu(II) and Ni(II) having the general composition[M(L)X2]with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.
Survival of the Fittest: An Active Queue Management Technique for Noisy Packet Flows
Authors: Karande Shirish S. , Misra Kiran , Radha Hayder
Published: September 2007

We present a novel active queue management (AQM) technique to demonstrate the efficacy of practically harnessing the predictive utility of SSR indications for improved video communication. We consider a network within which corrupted packets are relayed over multiple hops, but a certain percentage of packets needs to be dropped at an intermediate node due to congestion. We propose an AQM technique,survival of the fittest(SOTF), to be employed at the relay node, within which we use packet state information, available from SSR indications and checksums, to drop packets with the highest corruption levels. On the basis of actual 802.11b measurements we show that such a side information (SI) aware processing within the network can provide significant performance benefits over an SI-unaware scheme,random queue management(RQM), which is forced to randomly discard packets. With trace-based simulations, we show the utility of the proposed AQM technique in improving the error recovery performance of cross-layer FEC schemes. Finally, with the help of H.264-based video simulations these improvements are shown to translate into a significant improvement in video quality.
Interactive Multiview Video Delivery Based on IP Multicast
Authors: Lou Jian-Guang , Cai Hua , Li Jiang
Published: September 2007

As a recently emerging service, multiview video provides a new viewing experience with a high degree of freedom. However, due to the huge data amounts transferred, multiview video's delivery remains a daunting challenge. In this paper, we propose a multiview video-streaming system based on IP multicast. It can support a large number of users while still maintaining a high degree of interactivity and low bandwidth consumption. Based on a careful user study, we have developed two schemes: one is for automatic delivery and the other for on-demand delivery. In automatic delivery, a server periodically multicasts special effect snapshots at a certain time interval. In on-demand delivery, the server delivers the snapshots based on distribution of user requests. We conducted extensive experiments and user-experience studies to evaluate the proposed system's performance, and found that it provides satisfying multiview video service for users on a large scale.
Genetic Variation in the Response to Vaccination
Authors: Kimman T.G. , Vandebriel R.J. , Hoebee B.
Published: September 2007

Vaccines are the most powerful means to prevent and diminish the burden of infectious disease. However, there are limitations to their use: vaccines are not yet available for all infectious diseases (including human immunodeficiency virus and respiratory syncytial virus), they sometimes lack efficacy, the response to vaccination is limited by maternal antibodies in very young infants, and the response to vaccination is variable or may even be absent in some individuals. This review focuses on genetic factors that determine the variable response to vaccination. The highly polymorphic human leukocyte antigen system, which is involved in antigen presentation, has been researched most in this aspect, and clearly affects the response to vaccination. Other, but less polymorphic pathways involved are the Toll-like receptor pathway, which is involved in antigen recognition and stimulation of the immune system, and the cytokine immunoregulatory network. The heritability, or the proportion of total variance that is due to additive genetic factors, appears to be particularly large for vaccine-induced antibody responses in young infants compared with cell-mediated responses and antibody responses in older, immunologically more mature individuals. Both antibody and cell-mediated responses are not only affected by loci within, but also strongly by loci outside the human leukocyte antigen system. Because most genes that are important in influencing immune responses to vaccination are still unknown, clearly more work is required. A better understanding of the factors that determine an effective response to vaccination may lead to the identification of specific genes and pathways as targets for the development of novel more uniformly effective vaccines.
Different Perceptions and Attitudes regarding Prenatal Testing among Service Providers and Consumers in Israel
Authors: Mishori Dery Anat , Carmi Rivka , Shoham Vardi Ilana
Published: September 2007

Introduction: The increasing number of prenatal tests for fetal abnormalities calls for a prenatal care policy which will reflect not only medical values, but also the needs and attitudes of the services’ consumers. Objectives: To compare attitudes of prenatal service consumers and providers regarding extent of prenatal testing and to evaluate these attitudes in relation to sociodemographic and professional characteristics. Methods: Women were interviewed by phone 5–8 weeks postpartum (n = 596) using a structured questionnaire. Health professionals (n = 351) completed a parallel questionnaire. Results: Health professionals were significantly more supportive of comprehensive prenatal testing than women (61.1 vs. 34.1%, respectively). In a multivariable analysis, age over 35, Ashkenazi origin and being better informed regarding tests, predicted a preference for comprehensive testing among women. Among health professionals, predictors of that attitude were secularism and a paramedical profession. Conclusions: Providers and consumers of prenatal services differ in their perceptions and opinions. Policy makers should have mechanisms in place to properly represent this diversity.
Long-Term Attendance at Follow-Up of Women Assessed as Being at Increased Risk of Developing Breast Cancer in South-East Scotland
Authors: Holloway Susan , Porteous Mary , Cetnarskyj Roseanne , Anderson Elaine , Campbell Joyce , Steel Michael , Campbell Harry
Published: September 2007

Background: Women with a family history of breast cancer increasingly seek genetic advice and screening. In the present study we investigated referral rates and factors associated with long-term attendance for screening in Scotland. Methods: We investigated referral rates to the genetic service over a 21-month period and long-term attendance for screening amongst the 226 women at increased risk of developing breast cancer. Results: The overall annual referral rate was 0.31 per 1,000 patients on general practitioners’ lists. Some 98% of women for whom it was appropriate attended at least one screening appointment and 88% were continuing to attend appointments for surveillance up to 5 years later. Attendance was significantly lower among more socially deprived patients (p < 0.01). Conclusions: These results suggest that as increasing numbers of women with a positive family history seek risk assessment and screening, current facilities may be inadequate.
Exclusion and Inclusion Criteria for People with Aphasia in Studies of Depression after Stroke: A Systematic Review and Future Recommendations
Authors: Townend Ellen , Brady Marian , McLaughlan Kirsty
Published: September 2007

Background/Aims: A third of individuals are depressed following stroke. A similar proportion have aphasia. The extent of their inclusion in depression following stroke studies affects the generalizability of findings. Methods: We systematically reviewed published studies (to December 2005) that diagnosed depression following stroke. We identified aphasia screening methods, aphasia exclusion and inclusion criteria and respective numbers of individuals with aphasia. Results: Of 129 studies (n = 19,183), aphasia screening methods were only reported by 57 (31 described a published aphasia-specific tool). No mention of aphasia was made in 13 studies. Most studies (92, 71%) reported some exclusion of people with aphasia (49 reported how many: n = 3,082, range = 2–554). Almost half of the studies (60, 47%) actually reported participants with aphasia (37 specified numbers: n = 829, range = 5–60). Aphasia exclusion or inclusion was not associated with sample source (community, acute hospital, other) or study purpose (observation, intervention, screening). Studies that reported screening for aphasia were more likely to describe aphasia exclusion and inclusion criteria and include participants with aphasia. Conclusion: Aphasia screening, exclusion and inclusion criteria reporting across studies of depression following stroke has been highly inconsistent. This impairs the interpretation of generalizability. Improved aphasia screening and reporting of exclusion and inclusion criteria are urgently recommended.
Widespread Delta-Like-1 Expression in Normal Adult Mouse Tissue and Injured Endothelium Is Reflected by Expression of the Dll1LacZ Locus
Authors: Miceli-Libby Laura , Johnson Michael J. , Harrington Anne , Hara-Kaonga Bochiwe , Ng Ah-Kau , Liaw Lucy
Published: September 2007

Background: Our study characterizes Delta-like 1 (Dll1) in the adult mouse, particularly in normal versus injured vasculature, with the aid of the transgenic Dll1LacZ line. Methods: Normal mouse adult tissues or those from the Dll1LacZ reporter line were analyzed for Dll1 expression and promoter activity. Vascular tissue was analyzed before and after carotid artery ligation. Results: In wild-type mice, Dll1 transcript expression was widespread. Similarly, the Dll1LacZ reporter had β-galactosidase activity detectable in the cerebellum, cerebrum, spinal cord, liver, lung and cornea, although the normal adult vasculature had no reporter expression. Following arterial ligation, there was acute induction of Dll1LacZ reporter expression, both in the ligated left carotid artery, and the uninjured right contralateral artery. Expression returned to low/undetectable levels 4–10 days after arterial ligation. Conclusion: The expression of Dll1 in the adult mouse is more widespread than previously realized, although not in resting large arteries in the adult mouse. Following arterial injury, Dll1 promoter activity is induced selectively in the endothelial cells of both the injured artery and the contralateral uninjured artery. Our results show that while overall expression in the adult mouse is widespread, Dll1 may be selectively expressed in the endothelium of injured vasculature, similar to the endothelial-restricted expression of Dll4.
Twenty-Five–Year Experience With the Medtronic-Hall Valve Prosthesis in the Aortic Position
Authors: Svennevig Jan L. , Abdelnoor Michel , Nitter-Hauge Sigurd
Published: September 2007

Background—

The Medtronic-Hall valve was developed and for the first time implanted in Oslo, Norway, in 1977. A total of 1104 patients received this valve at Rikshospitalet from 1977 to 1987. In the present study, we followed up on all 816 patients undergoing aortic valve replacement over a 25-year period.

Methods and Results—

This is a retrospective cohort analysis of 816 consecutive patients undergoing aortic valve replacement with the Medtronic-Hall valve at Rikshospitalet, Oslo, Norway, from 1977 to 1987. All patients were contacted by means of questionnaires or telephone. Data were checked against hospital databases and medical records. Date of death was verified by the Norwegian civil registry. Follow-up was 99.6% complete. Survival analysis included operative deaths as well as late deaths. Survival at 25 years was 24.9%. No mechanical failures were found. Valve thrombosis was seen in 4 patients, in 1 case combined with pannus formation. Small valves (20 mm to 21 mm) were associated with reduced survival; however, when controlled for the confounding effects of age and gender, valve size did not remain a significant risk factor. Patient-related factors were important: Older age, female gender, and the need for concomitant coronary artery bypass surgery significantly reduced survival, whereas surgery of the ascending aorta did not. Linearized rates of thromboembolic complications, warfarin-related bleeding, and endocarditis were 1.5%, 0.7%, and 0.16%/patient-year, respectively. At follow-up, 79% of the patients were in New York Heart Association classes I to II.

Conclusions—

This study confirms the excellent long-term outcome for patients with Medtronic-Hall valves in the aortic position.
Nitrite Infusion in Humans and Nonhuman Primates
Authors: Dejam André , Hunter Christian J. , Tremonti Carole , Pluta Ryszard M. , Hon Yuen Yi , Grimes George , Partovi Kristine , Pelletier Mildred M. , Oldfield Edward H. , Cannon Richard O. , Schechter Alan N. , Gladwin Mark T.
Published: September 2007

Background—

The recent discovery that nitrite is an intrinsic vasodilator and signaling molecule at near-physiological concentrations has raised the possibility that nitrite contributes to hypoxic vasodilation and to the bioactivity of nitroglycerin and mediates the cardiovascular protective effects of nitrate in the Mediterranean diet. However, important questions of potency, kinetics, mechanism of action, and possible induction of tolerance remain unanswered.

Methods and Results—

In the present study, we performed biochemical, physiological, and pharmacological studies using nitrite infusion protocols in 20 normal human volunteers and in nonhuman primates to answer these questions, and we specifically tested 3 proposed mechanisms of bioactivation: reduction to nitric oxide by xanthine oxidoreductase, nonenzymatic disproportionation, and reduction by deoxyhemoglobin. We found that (1) nitrite is a relatively potent and fast vasodilator at near-physiological concentrations; (2) nitrite functions as an endocrine reservoir of nitric oxide, producing remote vasodilation during first-pass perfusion of the opposite limb; (3) nitrite is reduced to nitric oxide by intravascular reactions with hemoglobin and with intravascular reductants (ie, ascorbate); (4) inhibition of xanthine oxidoreductase with oxypurinol does not inhibit nitrite-dependent vasodilation but potentiates it; and (5) nitrite does not induce tolerance as observed with the organic nitrates.

Conclusions—

We propose that nitrite functions as a physiological regulator of vascular function and endocrine nitric oxide homeostasis and suggest that it is an active metabolite of the organic nitrates that can be used therapeutically to bypass enzymatic tolerance.
Antecedent Blood Pressure, Body Mass Index, and the Risk of Incident Heart Failure in Later Life
Authors: Lee Douglas S. , Massaro Joseph M. , Wang Thomas J. , Kannel William B. , Benjamin Emelia J. , Kenchaiah Satish , Levy Daniel , D’Agostino Ralph B. , Vasan Ramachandran S.
Published: September 2007

Higher blood pressure and body mass index (BMI) are risk factors for heart failure. It is unknown whether the presence of these risk factors in midadulthood affect the future development of heart failure. In the community-based Framingham Heart Study, we examined the associations of antecedent blood pressure and BMI with heart failure incidence in later life. We studied 3362 participants (57% women; mean age: 62 years) who attended routine examinations between 1969 and 1994 and examined their systolic and diastolic blood pressure, pulse pressure, and BMI at current (baseline), recent (average of readings obtained 1 to 10 years before baseline), and remote (average of readings obtained 11 to 20 years before baseline) time periods. During 67 240 person-years of follow-up, 518 participants (280 women) developed heart failure. Current, recent, and remote systolic pressure; pulse pressure; and BMI were individually associated with incident heart failure (all
P
<0.001). Recent systolic pressure (hazards ratio [HR] per 1-SD increment: 1.31; 95% CI: 1.11 to 1.55), pulse pressure (HR per 1-SD increment: 1.33; 95% CI: 1.14 to 1.54), and BMI (HR per unit increase: 1.15; 95% CI: 1.08 to 1.23) were associated with heart failure risk even after adjusting for current measures. Similarly, remote systolic pressure (HR per 1 SD: 1.17; 95% CI: 1.04 to 1.31), pulse pressure (HR per 1 SD: 1.17; 95% CI: 1.06 to 1.31), and BMI (HR per unit: 1.09; 95% CI: 1.05 to 1.14) remained associated with incident heart failure after adjusting for current measurements. Higher blood pressure and BMI in midlife are harbingers of increased risk of heart failure in later life. Early risk factor modification may decrease heart failure burden.
Sex and Body Mass Index Specific Regulation of Blood Pressure by
CYP19A1
Gene Variants
Authors: Ramirez-Lorca Reposo , Grilo Antonio , Martinez-Larrad Maria Teresa , Manzano Luis , Serrano-Hernando Francisco Javier , Moron Francisco Jesus , Perez-Gonzalez Vicente , Gonzalez-Sanchez Jose Luis , Fresneda Javier , Fernandez-Parrilla Rosario , Moñux Guillermo , Molero Eva , Sanchez Elena , Martinez-Calatrava Maria Jose , Saban-Ruiz Jose , Ruiz Agustin , Saez Maria Eugenia , Serrano-Rios Manuel
Published: September 2007

Sexual dimorphism in blood pressure (BP) regulation has been observed both in humans and experimental animals, and estrogens have been shown to contribute to this epidemiological observation. A key enzyme in determining estrogen levels is aromatase cytochrome P450. The aim of this study was to evaluate the role of the gene encoding aromatase,
CYP19A1
, as an independent risk factor for hypertension and its relationship with systolic and diastolic BP measures. We genotyped 2 polymorphisms within the
CYP19A1
gene, IVS4 rs11575899 and 3′UTR rs10046, in 3448 individuals. In quantitative analysis, we observed significant associations between the 2 polymorphisms and BP values in women, being these associations dependent on BMI and independent of menopause status. The case–control analysis revealed that the most prominent associations were found for nonobese women in diastolic hypertension (DHT): the
IVS4_22
and
3
′
UTR_11
are risk genotypes (OR=1.61,
P
=0.027 and OR=1.59,
P
=0.012, respectively), whereas
IVS4_11
and
3
′
UTR_22
genotypes have a protective effect against DHT (OR=0.63,
P
=0.009, and OR=0.61,
P
=0.020, respectively). Haplotype analysis confirmed the above associations: among nonobese women the haplotype
21
is overrepresented in hypertensive women (OR=1.33,
P
=0.004, for DHT and OR=1.25,
P
=0.026, for systolic hypertension, SHT) and, conversely, the haplotype
12
protects against hypertension (OR=0.78,
P
=0.015 for DHT and OR=0.82,
P
=0.04 for SHT). Our study has shown that the
CYP19A1
gene may be involved in the genetic regulation of BP in women. This effect is dependent on BMI and independent of menopause status, suggesting that this action is mainly driven by aromatase activity in fat tissue.
The transferability of management practices: Examining cross-national differences in reward preferences
Authors: Chiang Flora F.T. , Birtch Thomas
Published: September 2007

This study examines the multi-dimensional nature of reward preferences (i.e. types, systems, and criteria) in the cross-border context, an area not sufficiently addressed by prior research. We found empirical evidence to suggest both similarities and differences in employee reward preferences. Although culture may impinge on reward preferences, this study suggests that its influence may be diminishing or giving way to a range of other contextual forces. Directions for future research are also presented.