bluuebunny/crossref_metadata_2025 huggingface dataset:
GLOBALLY EXPONENTIAL HYPERCHAOS (LAG) SYNCHRONIZATION IN A FAMILY OF MODIFIED HYPERCHAOTIC RÖSSLER SYSTEMS
Authors: YAN ZHENYA , YU PEI
Published: August 2007

In this paper, we consider a new family of modified hyperchaotic Rössler systems, recently studied by Nikolov and Clodong using proper nonlinear feedback controllers. Particular attention is given to (i) globally exponential lag synchronization (GELS) for τ > 0; and (ii) globally exponential synchronization (GES) for τ = 0. As a representative example, one system of the family of modified hyperchaotic Rössler systems is particularly studied, and Lyapunov stability criteria for the GELS and GES are derived via eight families of proper nonlinear feedback controllers. Moreover, we also present some nonlinear feedback control laws for other modified hyperchaotic Rössler systems. Numerical simulations are used to illustrate the theoretical results.
A MODULE-BASED AND UNIFIED APPROACH TO CHAOTIC CIRCUIT DESIGN AND ITS APPLICATIONS
Authors: YU SIMIN , LÜ JINHU , CHEN GUANRONG
Published: August 2007

This paper proposes a module-based and unified approach to chaotic circuit design, where the description is based on the state equations without physical dimensions for simplicity of a general discussion. The main design process consists of transformation of state variables, transformation from differential to integral operations, and transformation of the time-scale. The designed circuit consists of anti-adder module integrator module, and inverter module. A novel 3-scroll Chua's circuit and a generalized Lorenz-like circuit are designed and implemented for verifying the effectiveness of this systematic circuit design methodology. Experimental observations are provided for confirmation. Comparing with the traditional circuit design methods, this new design approach has the following typical characteristics: (i) module-based and unified design; (ii) independent adjustment of system parameters; (iii) adjustment of distribution regions for the frequency spectra of chaotic signals; (iv) prominent observability.
PSEUDORAPIDITY DISTRIBUTION OF SHOWER PARTICLES IN 28Si-EMULSION INTERACTIONS AT 4.5 A GeV/c PER NUCLEON
Authors: SINGH B. K. , LIU FU-HU , SINGH G.
Published: August 2007

Pseudorapidity density distributions of relativistic charged particles produced in 28 Si -induced interactions in nuclear emulsion at JINR Synchrophasotron have been measured. The particle distributions in minimum-bias events exhibit a pronounced forward asymmetry with respect to the peak in the pseudorapidity spectra. The effect of intranuclear collisions on the mean pseudorapidity distribution versus the shower particles (ns) or the grey particles is discussed and compared with similar studies of 28 Si and 32 S at BNL AGS and CERN SPS energies respectively.
A Palaeogeological Map of the Lower Palaeozoic Floor below the cover of Upper Devonian, Carboniferous and Later Formations : with inferred and speculative reconstructions of Lower Palaeozoic and Precambrian outcrops in adjacent areas
Authors: Wills Leonard Johnston
Published: August 2007

It is four years since Professor Wills produced his outstanding pre‐Permian Palaeogeological Map of England and Wales, published by this Society with an explanatory memoir and now to be found on the walls of many working offices across the country. He was then 89 and it was assumed that this was his final production, a remarkable achievement in the face of great physical frailty.

Nevertheless he immediately moved on to a map of a stratigraphically deeper level — a palaeogeological map of the rocks following the Caledonian movements and the subsequent erosion, the surface of which would be exposed by the removal of Upper Devonian and later strata. This was completed and printed in 1975, and Wills began the equally complex task of writing an accompanying memoir to explain the way he had interpreted and applied the varied evidence of the deep structure. This process however led him to undertake still another map, that of the pre‐Devonian rocks of a belt extending from East Anglia to South Wales, which has been completed this year. These two maps form the coloured plates accompanying this memoir.

The memoir is also illustrated by a map of the Basal Elements, and by three Phanerozoic Time Scale sections, which illustrate the point which Wills has made before — that in the dominantly shelf environment of Britain the stratigraphical record is largely incomplete, with the lacunae at least comparable in time terms to the periods represented by sediments.

This publication, then, represents the further remarkable achievement of a man of 93 (— “and a half”, as he emphasises — he feels that months count now), working in a country study without technical support, his activity sharply limited by eye trouble and by a heart condition. It would have been a notable production for a fit man half his age. Both economic and academic geologists are already deeply indebted to Wills for his map of the pre‐Permian surface; these further compilations add more organised data and more food for thought about the past history and deep structure of Britain.
Late Precambrian and Cambrian geological time-scale
Authors: Cowie J. W. , Johnson M. R. W.
Published: August 2007

The suggestion by the Subcommission on Precambrian Stratigraphy (of the International Union of Geological Sciences) that the beginning of Late Proterozoic times should be defined in the geochronometric scale at 900 Ma is accepted; this probably correlates with the chronostratic scale at the Middle-Upper Riphean boundary. The Upper Riphean-Vendian boundary on the chronostratic scale seems to correlate with approximately 650 Ma. The chronostratic Precambrian-Cambrian boundary is poorly correlated with the chronometric scale on a global basis at present but may be more accurately related in the next decade or so. In the meantime a range of 530-600 Ma can be considered but no conclusions are offered here.

An attempt is made to give the present state of knowledge and techniques, with only a selection of radiometric data, especially those bearing more or less directly on the calibration of chrono-stratigraphic units. The geographic coverage is not intended to be complete.
Numerical calibration of the Palaeozoic time-scale; Ordovician, Silurian and Devonian periods
Authors: Gale N. H.
Published: August 2007

Thirty-five reliable dates for rock units of well-defined biostratigraphy within the Ordovician, Silurian and Devonian periods are listed. Two alternative graphical presentations of the data show that all the data, including Rb-Sr whole rock ages of acid rocks, are internally consistent. Less precise fission track dates are consistent with the other data, but too imprecise sufficiently to constrain the time-scale. Estimates are given for the numerical calibration of the base of the Carboniferous, Frasnian, Eifelian, Gedinnian, Llandovery, Caradoc, Llandeilo and Arenig, by considering the sets of reliable ages for rock units near each boundary.
Oceanic magnetic lineaments and the calibration of the late Mesozoic — Cenozoic time-scale
Authors: Curry Dennis
Published: August 2007

The pattern of magnetic reversals from mid-Cretaceous times onwards is now well-known from the study of ocean-floor spreading systems. Integration of the pattern of polarity reversals with the standard biostratigraphical time-scale is now well-advanced and, as a result, a series of recently proposed time-scales use the detailed pattern of magnetic lineaments, calibrated radio-metrically at a few points only, as their major control. The anomaly sequence generally accepted as standard is based on a single track across the South Atlantic and its representativeness of at least the greater part of the Cenozoic has never been seriously challenged. Assumption of a constant spreading rate with time has enabled detailed and apparently very accurate time-scales to be generated. However, spacings within anomaly sequences in the same oceanic area vary notably from track to track and oceanic areas themselves may exhibit characteristic patterns. Clearly, in detail, the rate of ocean-floor spreading with time is not constant, and the role of patterns of magnetic reversals in the construction of time-scales needs reevaluation in the light of this fact.
Processes and problems in the continental lithosphere: geological history and physical implications
Authors: Brown G. C.
Published: August 2007

Systematic changes in surface continental patterns of geology, tectonics and magma types reflect the unidirectional non-uniformitarian evolution of the continental lithosphere upon which the dominant constraint has been progressively declining terrestrial heat production. Widespread shallow asthenospheric mantle precluded the early stabilization of continental lithosphere, and the subsequent rapid growth of late Archaean continental crust implies considerable differences in the long-term thermal histories of oceanic and continental lithospheres. Proterozoic continental lithosphere rapidly became thick and refractory, though internally ductile, whilst oceanic lithosphere, the focus of terrestrial heat flow, remained relatively thin and plastic. This physical contrast probably has decreased in more recent times, a trend which may be coupled with the increased evidence for continental fragmentation in the Phanerozoic record. Finally, it is argued from thermal considerations, coupled with freeboard, isotopic and geochemical data, that continental growth has continued at a decreased and decreasing rate throughout post-Archaean time.
Chapter 1 Svalbard
Authors: Harland W. Brian
Published: August 2007

An introduction to Svalbard is as necessary for a geoscientist as for any other student of the archipelago. The section on geographical nomenclature is illustrated by maps which are designed to locate many of the commonly used names. These and others are listed at the end of the volume where additional names used later are referred to. The regional context of Svalbard is shown in Fig. 1.1.

The present-day physical environment is mentioned, but treated more fully in Chapters 21 and 22.

The section on the present-day Svalbard biota is not by a specialist for specialists, but is intended to list those organisms commonly encountered in the field and of interest to most workers.

The political and treaty considerations are interwoven and have sometimes left the Norwegian administration in an ambivalent position. Happily however the resources forthcoming from the petroleum industry to the nation has enabled the administration to fulfil its responsibility admirably and latterly without the pressures from the Cold War.

Svalbard for its size has a small population, less than 4000 concentrated in relatively few settlements, but numbers are augmented by summer arrivals of construction/maintenance staff, tourists, students and scientists, while the residents often take their summer holidays on the mainland. The environmental threat from this expanding seasonal population presents one of the most serious challenges, while at the same time tourism is replacing coal mining as the principal economic resource. Provision of shipping facilities supplemented by air travel is transforming the economy, which however still requires substantial
Chapter 8 Northwestern Spitsbergen
Authors: Harland W. Brian , Doubled Ay Paul A.
Published: August 2007

Northwestern Spitsbergen is bounded by Billefjorden and Wijde-fjorden in the east and by the coastline in the north and west round to the southwest by Kongsfjorden (Fig. 8.1). The southern boundary overlaps with the Central Basin (Chapter 4) and central western sector of Spitsbergen (Chapter 9) along Kongsfjorden and Sveabreen. At this boundary Devonian and older rocks are uncon-formably overlain, and finally obscured to the south, by the cover of Carboniferous through Paleogene strata. This sector contains Andree Land, Albert I Land, Haakon VII Land, James I Land and northern Dickson Land. It is deeply penetrated by fjords and largely covered by ice.

Apart from Quaternary sediments and volcanics, Cenozoic plateau lavas and the overlying platform sequence (Carboniferous through Paleogene) to the south, the main consideration here is with Devonian sediments, mid-Paleozoic migmatites and granites, and Precambrian metasediments.

The Northwestern sector is bounded and divided by faults. The eastern boundary is delineated by the Billefjorden Fault Zone (BFZ) and the southwestern boundary is the postulated Kongs-fjorden-Hansbreen Fault Zone (KHFZ). These faults separate the Central Province respectively from the Eastern and Western provinces. Two main N-S oriented faults divide the sector into three terranes: the Raudfjorden Fault (RFF), and the Breibogen Fault (BBF) (Fig. 8.1) as noted by Holtedahl (1914). The three terranes are introduced below. (1) The Andree Land-Dickson Land Terrane is a large area of Devonian strata bounded by the Breibogen Fault Zone and the Billefjorden Fault Zone. (2) The Biskayerfonna-Holtedahlfonna Terrane is a N-S belt bounded to the
Chapter 13 Vendian History
Authors: Harland W. Brian
Published: August 2007

The Vendian Period, the latest Precambrian division, and the earliest division in which several Phanerozoic methods of correlation can be applied, is a convenient time division for Svalbard. It is separated from the earlier history in which correlation has uncertainties of tens of millions of years if not more. The period is divided here into an early (Varanger) epoch and a late (Ediacara) epoch (Harland
et al
. 1990).

The Varanger Epoch is documented by remarkably rich sequences, correlated throughout (but limited in Prins Karls Forland and Bjornoya) by the two distinctive major glacial episodes: the earlier Smalfjord Stage and the Mortensnes Stage, with a substantial interglacial record between the diamictite horizons. The Vendian age of these glacigenic sediments is confirmed biostrati-graphically.

The Ediacara Epoch is only confirmed from the Scotia Group in Prins Karls Forland, identified by a microbiota. A number of conformable post-glacial successions are plausibly of Ediacara age: the Dracoisen and Klackbergbukta formations in the northeast; the Annabreen Formation in Oscar II Land; the Peachflya and Geikie as well as the Scotia Group in Prins Karls Forland; and the Bogstranda and Gashamna Formations in Hornsund. Nevertheless the second part of Vendian time is as yet poorly demonstrated in Svalbard.

According to the correlation followed here from Harland, Hambrey & Waddams (1993) based largely on the two glacial episodes, the outcrop area of Vendian strata is not small as shown in Fig. 13.1.

Vendian, as used here, is the latest Precambrian time-interval preceding the Cambrian Period. Whereas Cambrian and
Chapter 16 Devonian history
Authors: Harland W. Brian
Published: August 2007

Svalbard is part of the Old Red Sandstone province with affinities in East Greenland, Norway, Appalachian North America and, of course, the British Isles where the Devonian Period was defined. This allows Devonian history in this region, controlled by Caledonian events, to form a neat and natural chapter, though not necessarily a global one. Old Red Sandstone environments in each area were already becoming established in Late Silurian time. Olaf Holtedahl was the prime author of both Caledonian tectogenesis in Svalbard and the Old Red Sandstone aftermath.

Of the many and varied biotas of Svalbard the fossil fish have made remarkable and classic contributions to Spitsbergen geology.

The earliest 'Old Red Sandstone' Spitsbergen strata have yet to yield evidence of age and so may be latest Silurian (Siktefjellet Group). But the earliest Devonian strata to be identified biostratigraphically begin with the Red Bay Group. Similarly the (major) Ny Friesland Orogeny and the various late orogenic granite emplacements, while initially Silurian, continued at least to cool in Devonian time. For convenience the orogenic events that may continue as early Devonian are treated in the Silurian chapter and the sedimentary events that may be Silurian are treated here.

Devonian successions in Svalbard are known only from terranes which are postulated to have originated from the North East Greenland Province. No record has yet been established for Devonian strata in Svalbard either from the eastern terranes (East Greenland Province) or from the western terranes (North Greenland-Pearya Province). Moreover, the East Greenland succession lacks
Exploring Cyanobacterial Mutualisms
Authors: Usher Kayley M. , Bergman Birgitta , Raven John A.
Published: August 2007

Cyanobacterial symbioses with eukaryotes are ancient associations that are widely distributed in aquatic and terrestrial environments. Cyanobacteria are a significant driving force in the evolution of their hosts, providing a range of services including photosynthesis, nitrogen fixation, UV protection, and defensive toxins. Although widespread, cyanobacteria occur in a limited range of hosts. Terrestrial symbioses are typically restricted to lichens and early evolved plants, and aquatic symbioses to sessile or slow-moving organisms. This review examines the underlying evolutionary processes that may have lead to these patterns. It also examines the facts that the degree of integration between symbiont and host, and the mode of transmission of the symbiont, do not appear to be an indication of how old the symbiosis is or how important it is to host well-being. Biparental transmission of symbionts may prolong the survival of gametes that persist in the environment, increasing chances of fertilization.
Role of cAMP inhibition of p44/p42 mitogen-activated protein kinase in potentiation of protein secretion in rat lacrimal gland
Authors: Funaki Chika , Hodges Robin R. , Dartt Darlene A.
Published: August 2007

We previously found that addition of cAMP and a Ca2+/PKC-dependent agonist causes synergism or potentiation of protein secretion from rat lacrimal gland acini. In the present study we determined whether cAMP decreases p44/p42 mitogen-activated protein kinase (MAPK) activity in the lacrimal gland. Since we know that activation of MAPK attenuates protein secretion stimulated by Ca2+- and PKC-dependent agonists, we also determined whether this activation causes potentiation of secretion. Freshly prepared rat lacrimal gland acinar cells were incubated with dibutyryl cAMP (DBcAMP), carbachol (a cholinergic agonist), phenylephrine (an α1-adrenergic agonist), or epidermal growth factor (EGF). The latter three agonists are known to activate p44/p42 MAPK. p44/p42 MAPK activity and protein secretion were measured. As measured by Western blot analysis, DBcAMP inhibited both basal and agonist-stimulated p44/p42 MAPK activity. Cellular cAMP levels were increased by 1) using two different cell-permeant cAMP analogs, 2) activating adenylyl cyclase (L-858051), or 3) activation of Gs-coupled receptors (VIP). The cell-permeant cAMP analogs, L-858051, and VIP inhibited basal p44/p42 MAPK activity by 50, 40, and 40%, respectively. DBcAMP and VIP inhibited carbachol- and EGF-stimulated MAPK activity. cAMP, but not VIP, inhibited phenylephrine-stimulated MAPK activity. Potentiation of secretion was detected when carbachol, phenylephrine, or EGF was simultaneously added with DBcAMP. We conclude that increasing cellular cAMP levels inhibits p44/p42 MAPK activity and that this could account for potentiation of secretion obtained when cAMP was elevated and Ca2+ and PKC were increased by agonists.
MEKK3 is required for endothelium function but is not essential for tumor growth and angiogenesis
Authors: Deng Yong , Yang Jianhua , McCarty Marya , Su Bing
Published: August 2007

Mitogen-activated protein kinase kinase kinase 3 (MEKK3) plays an essential role in embryonic angiogenesis, but its role in tumor growth and angiogenesis is unknown. In this study, we further investigated the role of MEKK3 in embryonic angiogenesis, tumor angiogenesis, and angiogenic factor production. We found that endothelial cells from Mekk3-deficient embryos showed defects in cell proliferation, apoptosis, and interactions with myocardium in the heart. We also found that MEKK3 is required for angiopoietin-1 (Ang1)-induced p38 and ERK5 activation. To study the role of MEKK3 in tumor growth and angiogenesis, we established both wild-type and Mekk3-deficient tumor-like embryonic stem cell lines and transplanted them subcutaneously into nude mice to assess their ability to grow and induce tumor angiogenesis. Mekk3-deficient tumors developed and grew similarly as control Mekk3 wild-type tumors and were also capable of inducing tumor angiogenesis. In addition, we found no differences in the production of VEGF in Mekk3-deficient tumors or embryos. Taken together, our results suggest that MEKK3 plays a critical role in Ang1/Tie2 signaling to control endothelial cell proliferation and survival and is required for endothelial cells to interact with the myocardium during early embryonic development. However, MEKK3 is not essential for tumor growth and angiogenesis.
Rapid recovery of releasable vesicles and formation of nonreleasable endosomes follow intense exocytosis in chromaffin cells
Authors: Perez Bay Andrés E. , Ibañez Lorena I. , Marengo Fernando D.
Published: August 2007

Neurons and neuroendocrine cells must retrieve plasma membrane excess and refill vesicle pools depleted by exocytosis. To perform these tasks cells can use different endocytosis/recycling mechanisms whose selection will impact on vesicle recycling time and secretion performance. We used FM1-43 to evaluate in the same experiment exocytosis, endocytosis, and recovery of releasable vesicles on mouse chromaffin cells. Various exocytosis levels were induced by a variety of stimuli, and we discriminated the resultant endocytosis-recycling responses according to their ability to rapidly generate releasable vesicles. Exocytosis of ≤20% of plasma membrane (provoked by nicotine/acetylcholine) was followed by total recovery of releasable vesicles. If a stronger stimulus (50 mM K+ and 2 mM Ca2+) provoking intense exocytosis (51 ± 7%) was applied, endocytosis still retrieved all the fused membrane, but only a fraction (19 ± 2%) was releasable by a second stimulus. Using ADVASEP-7 or bromophenol blue to quickly eliminate fluorescence from noninternalized FM1-43, we determined that this fraction became releasable in <2 min. The remaining nonreleasable fraction was distributed mainly as fluorescent spots (∼0.7 μm) selectively labeled by 40- to 70-kDa dextrans and was suppressed by a phosphatidylinositol-3-phosphate kinase inhibitor, suggesting that it had been formed by a bulk retrieval mechanism. We concluded that chromaffin cells can rapidly recycle significant fractions of their total vesicle population, and that this pathway prevails when cholinergic agonists are used as secretagogues. When exocytosis exceeded ∼20% of plasma membrane, an additional mechanism was activated, which was unable to produce secretory vesicles in our experimental time frame but appeared crucial to maintaining membrane surface homeostasis under extreme conditions.
Localization of ammonia transporter Rhcg1 in mitochondrion-rich cells of yolk sac, gill, and kidney of zebrafish and its ionic strength-dependent expression
Authors: Nakada Tsutomu , Hoshijima Kazuyuki , Esaki Masahiro , Nagayoshi Saori , Kawakami Koichi , Hirose Shigehisa
Published: August 2007

Members of the Rh glycoprotein family have been shown to be involved in ammonia transport in a variety of species. Here we show that zebrafish Rhcg1, a member of the Rh glycoprotein family, is highly expressed in the yolk sac, gill, and renal tubules. Molecular cloning and characterization indicate that zebrafish Rhcg1 shares 82% sequence identity with the pufferfish ortholog fRhcg1. RT-PCR, combined with in situ hybridization, revealed that Rhcg1 is first expressed in vacuolar-type H+-ATPase/mitochondrion-rich cells (vH-MRC) on the yolk sac of larvae at 3 days postfertilization (dpf) and later in vH-MRC-like cells in the gill at 4–5 dpf. Ammonia excretion from zebrafish larvae increased in parallel with the expression of Rhcg1. At larval stages, Rhcg1 mRNA was detected only on the yolk sac and gill; however, the kidney, as well as the gill, becomes a major site of Rhcg1 expression in adults. Using a zebrafish Tol2 transgenic line whose vH-MRC are labeled with green fluorescent protein (GFP) and an antibody against zebrafish Rhcg1, we demonstrate that Rhcg1 is located in the apical regions of 1) vH-MRC on the yolk sac and vH-MRC-like cells (cell population with the expression of Rhcg1 and GFP) in the gill and 2) cells in the renal distal tubule and intercalated cell-like cells in the collecting duct of the kidney. Remarkably, expression of Rhcg1 mRNA at the larval stage was changed by environmental ionic strength. These results suggest that roles of zebrafish Rhcg1 are not solely ammonia secretion to eliminate nitrogen from the gill.
Cadmium causes delayed effects on renal function in the offspring of cadmium-contaminated pregnant female rats
Authors: Jacquillet G. , Barbier O. , Rubera I. , Tauc M. , Borderie A. , Namorado M. C. , Martin D. , Sierra G. , Reyes J. L. , Poujeol P. , Cougnon M.
Published: August 2007

In the adult rat, chronic cadmium intoxication induces nephropathy with Fanconi-like features. This result raises the question of whether intoxication of pregnant rats has any deleterious effects on renal function in their offspring. To test this hypothesis, we measured the renal function of 2- to 60-day-old postnatal offspring from female rats administered cadmium chloride by the oral route (0.5 mg·kg−1·day−1) throughout their entire gestation. Investigations of rat offspring from contaminated pregnant rats showed the presence of cadmium in the kidney at gestational day 20. After birth, the cadmium kidney concentration increased from postnatal day 2 to day 60 (PND2 to PND60), presumably because of 1) milk contamination and 2) neonatal liver cadmium content release. Although the renal parameters (glomerular filtration, U/P inulin, and urinary excretion rate) were not significantly affected until PND45, renal failure appeared at PND60, as demonstrated by a dramatic decrease of the glomerular filtration rate associated with increased excretion of the main ions. In parallel, an immunofluorescence study of tight-junction protein expression of PND60 offspring from contaminated rats showed a disorganization of the tight-junction proteins claudin-2 and claudin-5, specifically expressed in the proximal tubule and glomerulus, respectively. In contrast, expression of a distal claudin protein, claudin-3, was not affected. In conclusion, in utero exposure of cadmium leads to toxic renal effects in adult offspring. These results suggest that contamination of pregnant rats is a serious and critical hazard for renal function of their offspring.
Validating Determinants for an Alternate Foot Placement Selection Algorithm During Human Locomotion in Cluttered Terrain
Authors: Moraes Renato , Allard Fran , Patla Aftab E.
Published: August 2007

The goal of this study was to validate dynamic stability and forward progression determinants for the alternate foot placement selection algorithm. Participants were asked to walk on level ground and avoid stepping, when present, on a virtual white planar obstacle. They had a one-step duration to select an alternate foot placement, with the task performed under two conditions: free (participants chose the alternate foot placement that was appropriate) and forced (a green arrow projected over the white planar obstacle cued the alternate foot placement). To validate the dynamic stability determinant, the distance between the extrapolated center of mass (COM) position, which incorporates the dynamics of the body, and the limits of the base of support was calculated in both anteroposterior (AP) and mediolateral (ML) directions in the double support phase. To address the second determinant, COM deviation from straight ahead was measured between adaptive and subsequent steps. The results of this study showed that long and lateral choices were dominant in the free condition, and these adjustments did not compromise stability in both adaptive and subsequent steps compared with the short and medial adjustments, which were infrequent and adversely affected stability. Therefore stability is critical when selecting an alternate foot placement in a cluttered terrain. In addition, changes in the plane of progression resulted in small deviations of COM from the endpoint goal. Forward progression of COM was maintained even for foot placement changes in the frontal plane, validating this determinant as part of the selection algorithm.
Potentiation Phase of Spike Timing-Dependent Neuromodulation by a Serotonergic Interneuron Involves an Increase in the Fraction of Transmitter Release
Authors: Sakurai Akira , Calin-Jageman Robert J. , Katz Paul S.
Published: August 2007

In the mollusk, Tritonia diomedea, the serotonergic dorsal swim interneuron (DSI) produces spike timing-dependent neuromodulation (STDN) of the synaptic output of ventral swim interneuron B (VSI) resulting in a biphasic, bidirectional change of synaptic strength characterized by a rapid heterosynaptic potentiation followed by a more prolonged heterosynaptic depression. This study examined the mechanism underlying the potentiation phase of STDN. In the presence of 4-aminopyridine, which blocks the depression phase and enhances transmitter release from VSI, rapidly stimulating VSI led to a steady-state level of transmitter depletion during which potentiation by DSI or serotonin (5-HT) was eliminated. Cumulative plots of excitatory postsynaptic currents were used to estimate changes in the size and replenishment rate of the readily releasable pool (RRP) and the fraction of release. 5-HT application increased transmitter release without altering replenishment rate. The magnitude of 5-HT-evoked potentiation correlated with the increase in the fraction of release. A phenomenological model of the synapse further supported the hypothesis that 5-HT-induced potentiation was caused by an increase in the fraction of release and correctly predicted no change in frequency facilitation. A dynamic version of the model correctly predicted the effect of DSI stimulation under a variety of conditions. Finally, depletion of internal Ca2+ stores with cyclopiazonic acid showed that Ca2+ from internal stores is necessary for the 5-HT-induced potentiation. The data indicate that 5-HT released from DSI increases the fraction of the RRP discharged during VSI action potentials using a mechanism that involves Ca2+ extrusion from internal stores, resulting in time- and state-dependent neuromodulation.
The Rights of People with an Intellectual Disability in the Netherlands: From Restriction to Development
Authors: Frederiks
Published: August 2007

The purpose of this article is to discuss whether the right to self-determination 1 is the only and the best principle in health law for care providers to support their clients with an intellectual disability, or whether other principles such as the right to development, the right to good care and the right to protection might lead to a better protection of the rights of clients in this field of care. The right to self-determination is the central principle in the Dutch Psychiatric Hospitals (Compulsory Admissions) Act, which at times seems less than beneficial to the legal position of persons with an intellectual disability. The question is whether a new (alternative) legal framework, in which the focus shifts to the right to good care and the right to development, might improve the legal position of people with an intellectual disability.
Ambiguity of the Embryo Protection in the Human Rights and Biomedicine Convention: Experiences from the Nordic Countries
Authors: Walin Laura
Published: August 2007

Until 1998 research on in vitro human embryos concentrated on the issues related to assisted reproduction. The situation changed dramatically when the first scientific report on the laboratory culture of human embryonic stem cells was published. This scientific breakthrough with new therapeutic promises put human embryo into a new, more vulnerable position. Combined with creation of embryos via somatic cell nuclear transfer, it inveigles into mass production of embryos, first for scientific purposes, but later perhaps for the healing of people.This article examines the efficacy of the Convention on Human Rights and Biomedicine in protecting embryos in this new era of embryo research. The interpretative latitude of Article 18 of the Convention is demonstrated, and legislation in three Nordic countries with highly variable approach to embryo research regulation is analysed. I examine how this divergence is possible in the light of the Convention text. In the end, potential reasons for variation in regulation in the otherwise similar Nordic countries are discussed, as well as under what conditions harmonisation of regulation on embryo research, a highly value-charged matter, could be possible at the European level.
Striking the Right Balance: Patient's Rights and Opposing Interests with Regard to Health Information
Authors: Hartlev Mette
Published: August 2007

In this article, the author explores the nature of confidentiality in the doctor-patient relationship and discusses the extent to which patient's rights to confidentiality, privacy and autonomy are balanced by a professional interest in good care and the organizational interest in administrative efficiency.
Variational Pseudo-Multiple-Doppler Wind Retrieval in the Vertical Plane for Ground-Based Mobile Radar Data
Authors: Weiss Christopher C. , Bluestein Howard B. , Conzemius Robert , Fedorovich Evgeni
Published: August 2007

A variational procedure is developed that utilizes mobile ground-based range–height indicator (RHI) Doppler radar velocity data for the synthesis of two-dimensional, RHI plane wind vectors. The radial component winds are obtained with the radar platform in motion, a data collection strategy referred to as the rolling RHI technique. Using the assumption of stationarity—standard to any pseudo-multiple-Doppler processing technique—individual radial velocity values at a given point in space will contribute a varying amount of independent information to the two components of wind velocity in the RHI plane, depending strongly on the difference in radar viewing angles amongst the looks.

The variational technique is tested successfully with observation system simulation experiments, using both a homogeneous flow field and large eddy simulation (LES) output from a highly sheared convective boundary layer simulation. Pseudoradar data are collected in these tests in a manner consistent with the specifications of the University of Massachusetts mobile W-band radar, which was used in a separate study to resolve the finescale structure of a dryline during the International H2O Project (IHOP_2002). The results of these tests indicate clearly that the technique performs well in regions of adequate “look” angle separation. Observation error contributes significantly to the analysis when the radar looks become more collinear.
Depolarization in Ice Crystals and Its Effect on Radar Polarimetric Measurements
Authors: Ryzhkov Alexander V. , Zrnić Dusan S.
Published: August 2007

Simultaneous transmission and reception of horizontally and vertically polarized waves is a preferable choice technique for dual-polarization weather radar. One of the consequences of such a choice is possible cross-coupling between orthogonally polarized waves. Cross-coupling depends on depolarizing properties of propagation media, and it is usually negligible in rain because the net mean canting angle of raindrops is close to zero.

Snow crystals at the tops of thunderstorm clouds are often canted in the presence of strong electric fields and produce noticeable cross-coupling between radar signals at horizontal and vertical polarizations if both signals are transmitted and received simultaneously. As a result, peculiar-looking radial signatures of differential reflectivity ZDR and differential phase ΦDP are commonly observed in the crystal regions of thunderstorms.

The paper presents examples of strong depolarization in oriented crystals from the data collected by the polarimetric prototype of the Weather Surveillance Radar-1988 Doppler (WSR-88D) and a theoretical model that explains the results of measurements. It is shown that the sign and magnitude of the ZDR and ΦDP signatures strongly depend on the orientation of crystals and a system differential phase on transmission.
Solar Power for Autonomous Floats
Authors: D’Asaro Eric A.
Published: August 2007

Advances in low-power instrumentation and communications now often make energy storage the limiting factor for long-term autonomous oceanographic measurements. Recent advances in photovoltaic cells, with efficiencies now close to 30%, make solar power potentially viable even for vehicles such as floats that only surface intermittently. A simple application, the development of a solar-powered Argos recovery beacon, is described here to illustrate the technology. The 65-cm2 solar array, submersible to at least 750 dbar, powers an Argos beacon. Tests indicate that with minor improvements the beacon will run indefinitely at any latitude equatorward of about 50°. Scaling up this design to current operational profiling floats, each profile could easily be powered by a few hours of solar charging, a shorter time than is currently being used for Argos data communications.
Spectral Density of Polarimetric Variables Separating Biological Scatterers in the VAD Display
Authors: Bachmann Svetlana , Zrnić Dusan
Published: August 2007

Echoes in clear air from two types of biological scatterers mixed within the resolution volumes over a large region, observed with S-band dual polarization radar, are presented. This case occurred in the evening of 7 September 2004, at the beginning of the fall migrating season of song birds (passerines). Polarimetric spectral analyses are used for distinguishing birds and insects in multimodal spectra. Spatial continuity of spectral peaks shows clear separation of insect (wind) speeds from bird speeds. Spectral densities of polarimetric variables exhibit vastly different values at speeds corresponding to insects than from those of birds, allowing the separation of the two scatterer types. Therefore, the statistics of the intrinsic polarimetric variables computed from spectral densities are unbiased and closer to the ensemble statistics of the echo type than the ones obtained with standard processing techniques. A novel display of the spectral densities versus azimuth, termed spectral velocity–azimuth display (SVAD), is constructed for easier viewing and interpretation of the velocity field. Analyses of the SVADs reveal the mean velocities and the directions of the two types of scatterers.
Politics over Official Language in the United States
Authors: Ray Saumyajit
Published: August 2007

The founding fathers did not designate English—or any other language—as the official language of the United States (US). It would be moot to ask if they considered it necessary to lay down in law what existed in fact, or whether they desisted from granting official language status to English out of their respect for ‘language minorities’ already in the new republic. Attempts were made from the early days of the republic to standardize their English language in the US for both practical and lexicographic purposes. But no movement aimed at making English the official language of the US emerged till 1981. The ‘Official English’ (deridingly called English Only) movement has till date got twenty-seven states to adopt it as their official language. Its first national success came when the US House of Representatives passed H.R. 123 in 1996 declaring English as the official language. This success, though, was short-lived as the bill lapsed due to the Senate inaction. The second national success came when the Senate passed the English Language Amendment to the latest Immigration Reform Bill, designating English as America's ‘national language’. However, the Democratic Party's opposition to Official English and the Republican Party's reluctance to officially associate with Official English means that the movement has a long way to traverse.
A Predictive Method for Estimating the Minimum Dynamic Critical System Pressure Required to Disperse Blowing Agent in Polystyrene
Authors: Suh Kyung W.
Published: August 2007

A predictive method for estimating the minimum dynamic critical system pressure required to disperse the blowing agents in molten polystyrene has been introduced based on the relationship between dynamic and equilibrium solubility determined using the Theory of Corresponding States. This method can be used to estimate the minimum dynamic system pressure required to disperse new blowing agent systems as a function of temperature and blowing agent concentration in the foam extrusion line. A brief discussion on the effect of dynamic system pressure on the cellular structure, skin, quality, and the pressure drop calculations through the foam extrusion line will be given.
Novel Soft Touch, Low Abrasion, Fine Cell Polyolefin Foams
Authors: Subramonian Suresh , Filiccia Phil , Alcott Jeff
Published: August 2007

Recent technical breakthroughs have enabled the development of soft touch, fine cell, noncrosslinked polyolefin foams. By optimizing the foam formulation and processing/forming conditions, the foam properties and performance attributes have been tailored to match that of crosslinked polyolefin foams in automotive material handling applications. Environmental pressures have created an unmet market need for a 100% recyclable, low-cost replacement product. This article details the physical properties, cushioning characteristics, abrasion performance, and thermoformability of the tough, resilient foams. The durable foams absorb shock, dampen vibration, and protect fragile products with high-quality surfaces from abrasion during handling, storage, and transportation. The foams thermoform over a relatively broad temperature range at low-to-moderate draws to produce well-defined fabricated products that closely match the mold contours while preserving cellular structure. The unique attributes of the noncrosslinked foams facilitate their penetration into several market segments currently dominated by crosslinked foams.
Physical Characteristics of PLLA/PMMA Blends and Their CO2 Blowing Foams
Authors: Yao Baisheng , Nawaby A. Victoria , Liao Xia , Burk Robert
Published: August 2007

This article reports on sample preparation, characterization, CO2 sorption behavior, and foaming of blends of poly L-lactic acid (PLLA) and poly methyl methacrylate (PMMA) in compositions of 75/25, 50/50, and 25/75 wt.%. The crystallization and thermal decomposition behavior of the polymer blends were found to be dependant on concentration of PLLA in the samples. Annealing the specimens in air at 90°C for 24 h resulted in complete recrystallization in the 75/25 and 50/50 wt.% samples. Detailed studies on the sorption kinetics of CO2 in the prepared blend samples indicated gas solubilities to be comparable to those observed in neat PMMA, however, foam morphologies significantly improved in the blends when compared to neat PLLA.
The Hook Test for Distal Biceps Tendon Avulsion
Authors: O'Driscoll Shawn W. , Goncalves Lucas B. J. , Dietz Patricio
Published: August 2007

Background

Complete biceps tendon avulsions are frequently missed on clinical examination, suggesting the need for a reliable diagnostic test.

Hypothesis

Complete distal biceps avulsions can be reliably detected with the Hook test.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

The hook test was performed by a single surgeon in a cohort of 45 patients undergoing surgical exploration of the distal biceps tendon. While the patient actively supinates with the elbow flexed 90°, an intact hook test permits the examiner to hook his or her index finger under the intact biceps tendon from the lateral side. With an abnormal hook test, indicating distal avulsion, there is no cord-like structure under which the examiner may hook a finger.

Results

Thirty-three patients had an avulsion and 12 had a partial tear. The hook test was abnormal in 33 of 33 (100%) patients with complete biceps avulsions, and intact in 12 of 12 with partial detachments. However, it was painful in 9 of those 12. In the noninjured contralateral arms, which served as the normal control group, 45 of 45 (100%) had a normal hook test. Magnetic resonance imaging (MRI) diagnosed a complete tear in 11 of 12 patients with partial tears and in 11 of 13 with complete lesions. The sensitivity and specificity were both higher with the hook test (both 100%) than with MRI (92% and 85%, respectively).

Conclusions

The hook test is a highly sensitive and specific test for assessment of distal biceps tendon avulsions.
E-Glass—Polypropylene Pultruded Nanocomposite: Manufacture, Characterization, Thermal and Mechanical Properties
Authors: Hussain Farzana , Roy Samit , Narasimhan K. , Vengadassalam K. , Lu H.
Published: August 2007

Polypropylene (PP) nanocomposites consisting of E-glass are manufactured by the process of pultrusion. Thermal and mechanical characterization of nanocomposite has been performed and compared with that of traditional microcomposites. In addition, the nanocomposite is characterized by means of optical micrographs (OPM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). TGA and DSC results show that nanoclay improves the thermal stability in the system without any deviation in glass transition temperature and melt temperature. Initially, PP and nanoclay are melt intercalated using a single-screw extruder and the pultruded nanocomposite is fabricated using extruded preimpregnated (pre-preg) tapes. Compression tests are performed as mandated by ASTM guidelines with 1—10 wt% of nanoclay in fiber reinforced PP. OPM are taken to examine the failure surfaces. TEM results reveal the intercalated morphology. Mechanical tests are performed at an independent testing facility for baseline pultruded PP nanocomposite with 0 wt% nanoclay and modified pultruded PP nanocomposite with 3 wt% nanoclay. The tests show significant improvement in compressive strength (~122%) and shear strength (~60%) in modified pultruded PP nanocomposites in comparison with baseline properties. Uni-axial tensile tests show a minor increase in tensile strength (~3.4%). Multi-scale simulations of nanoclay—polymer interface behavior are currently in progress in order to understand the strength enhancement mechanism.
In Conversation With Hans Ulrich's Wie Geschöpfe Leben
Authors: Reinders Hans S.
Published: August 2007

This paper presents Hans Ulrich's account of Christian ethics as an ethics of `vocation'. It is interested in how Ulrich's account of vocational ethics is developed as a critique of professional ethics. Professional ethics is seen as reflecting the structures of ethical deliberation of the social order that produces it, thereby failing to move beyond the realm of `works'. In contrast, the distinguishing characteristic of Ulrich's vocational ethics is shown to be that it is a response to the Word `from outside'. Consequently, a Christian account of professional ethics needs to show how it can retain a `theological difference' that enables it to respond to the Word that `breaks in' to start something new. The paper discusses the transformation of professionalism in a neo-liberal service economy in order to find out how this `breaking in' actually proceeds. Its test case is providing services to people with intellectual disabilities.