bluuebunny/crossref_metadata_2025 huggingface dataset:
GABA, progesterone and zona pellucida activation of PLA2 and regulation by MEK‐ERK1/2 during acrosomal exocytosis in guinea pig spermatozoa
Authors: Chen Wen-Ying , Ni Ya , Pan Yong-Miao , Shi Qi-Xian , Yuan Yu-Ying , Chen Ai-Jun , Mao Li-Zhen , Yu Shu-Qing , Roldan Eduardo R.S.
Published: August 2005

We investigated whether GABA activates phospholipase A2 (PLA2) during acrosomal exocytosis, and if the MEK‐ERK1/2 pathway modulates PLA2 activation initiated by GABA, progesterone or zona pellucida (ZP). In guinea pig spermatozoa prelabelled with [14C]arachidonic acid or [14C]choline chloride, GABA stimulated a decrease in phosphatidylcholine (PC), and release of arachidonic acid and lysoPC, during exocytosis. These lipid changes are indicative of PLA2 activation and appear essential for exocytosis since inclusion of aristolochic acid (a PLA2 inhibitor) abrogated them, along with exocytosis. GABA activation of PLA2 seems to be mediated, at least in part, by diacylglycerol (DAG) and protein kinase C since inclusion of the DAG kinase inhibitor R59022 enhanced PLA2 activity and exocytosis stimulated by GABA, whereas exposure to staurosporine decreased both. GABA‐, progesterone‐ and ZP‐induced release of arachidonic acid and exocytosis were prevented by U0126 and PD98059 (MEK inhibitors). Taken together, our results suggest that PLA2 plays a fundamental role in agonist‐stimulated exocytosis and that MEK‐ERK1/2 are involved in PLA2 regulation during this process.
CO: A chemical ontology for identification of functional groups and semantic comparison of small molecules
Authors: Feldman Howard J. , Dumontier Michel , Ling Susan , Haider Norbert , Hogue Christopher W.V.
Published: August 2005

A novel chemical ontology based on chemical functional groups automatically, objectively assigned by a computer program, was developed to categorize small molecules. It has been applied to PubChem and the small molecule interaction database to demonstrate its utility as a basic pharmacophore search system. Molecules can be compared using a semantic similarity score based on functional group assignments rather than 3D shape, which succeeds in identifying small molecules known to bind a common binding site. This ontology will serve as a powerful tool for searching chemical databases and identifying key functional groups responsible for biological activities.
Aggressive Digital Papillary Adenocarcinoma Presenting as a Paronychia of the Finger
Authors: GORVA A. D. , MOHIL R. , SRINIVASAN M. S.
Published: August 2005

Aggressive digital papillary adenocarcinoma is a rare skin adnexal tumour, which has a predilection for the digits. We report a case of this tumour presenting as a simple nail bed infection.
Hospital technology and nurse staffing management decisions
Authors: Li Ling , Benton W.C.
Published: August 2005

In this study, the key technology and nurse management decisions made by US hospitals in response to market needs were identified. It has been shown that technology implementation places a strong demand on nurse staff competency. While new strategic information systems are emerging, hospitals must provide on‐the‐job technological training for their nursing staffs. Of course, technology is not a cure‐all; rather, it is a tool that can be used by skilled nurse professionals in transforming sick patients into well patients with reasonable efficiency. The causal relationships between technology, nurse management decisions and performance established in this study are an important addition to the healthcare services literature. The results of our study also show that given the size constraint, large hospitals tend to invest more in equipment and technology for providing technology related services as compared to smaller hospitals. On the other hand, small rural hospitals tend to place more emphasis on staff development than their counterparts in urban areas.
Reforming Parliamentary Democracy
Authors: Franks C.E.S.
Published: August 2005

Reforming Parliamentary Democracy, F. Leslie Seidle and David C.
Docherty, eds., Montreal & Kingston: McGill-Queen's University
Press, 2003, pp. vii, 246

This book derives from a conference held by the Canadian Study of
Parliament Group at which distinguished persons discussed the efforts for
reform in Westminster style parliamentary democracies. Topics covered
include: second chambers (the British House of Lords, South Africa);
proportional representation (New Zealand); the role of the Crown
(Australia); political rights and representation of aboriginal peoples
(New Zealand and Canada); and federalism and devolution (Britain and
Canada). An introduction and conclusion by the editors, and a useful
chapter by Jennifer Smith on reform of the Canadian Parliament complete
the book.
The Politics of Public Management: The HRDC Audit of Grants and
Contributions
Authors: Evans Bryan
Published: August 2005

The Politics of Public Management: The HRDC Audit of Grants and
Contributions, David A. Good, The Institute of Public Administration of
Canada Series in Public Management and Governance; Toronto, University of
Toronto Press, 2003, pp. 240

The literature in public administration in some ways suffers from not
having more practitioners reflecting, writing and analyzing their
experiences. Thus David Good's book analyzing the HRDC's
so-called “billion dollar boondoggle” is a welcome
contribution. His background as both a senior manager/executive within
the Federal government and his academic credentials—a doctorate in
policy and administration sets him apart—as a practitioner-academic.
Good possesses the senior public manager's mind for detail and this
book provides a clear account of the ebbing and flowing of events,
beginning with the January 2000 release of HRDC's internal audit that
implied a loss of a billion dollars, to the Auditor General's report
of October that same year which, while critical of monitoring and
reporting practices, concluded that only $85,000 was unaccounted for. The
media and the opposition, at this point quickly lost interest.
Brève histoire philosophique de l'Union
soviétique
Authors: Labelle Gilles
Published: August 2005

Brève histoire philosophique de l'Union soviétique,
Fabrice Bouthillon, Paris : Plon/Commentaire, 2003, 195 p.

Ce petit ouvrage au titre intrigant est iconoclaste sous plus
d'un rapport. L'auteur l'a élaboré “ en
dépit de toutes les règles du bon sens universitaire ”
(15): ne sachant pas un mot de russe, il en a forgé les
idées dans un cours de premier cycle (plutôt que dans des
séminaires d'études supérieures ou dans des
colloques spécialisés) et l'a écrit à
Brest (plutôt qu'à Paris, seule ville de France
où l'on pense sérieusement, comme chacun sait).
Défenseur, comme l'indique le titre de l'ouvrage,
d'une “ histoire philosophique ” ,
c'est-à-dire d'une histoire qui cherche à
conceptualiser l'événement à mesure qu'en
est exposée la trame, l'auteur n'hésite pas, en
outre, à puiser dans l'héritage plus que suspect de la
tradition contre-révolutionnaire (Burke, Bonald, Maistre), laquelle
insiste sur l'antériorité et la pesanteur des
structures dans lesquelles sont enracinés les individus (histoire
ou langue). Il en résulte un ouvrage éblouissant
d'intelligence et d'une ironie mordante—chose rare dans
une université où, comme le relève l'auteur,
règne souvent un “ ennui lourd, massif, profond ”
(11).
Regionalism in a Global Society: Persistence and Change in Atlantic
Canada and New England
Authors: Cody Howard
Published: August 2005

Regionalism in a Global Society: Persistence and Change in Atlantic
Canada and New England, Stephen G. Tomblin and Charles S. Colgan, eds.,
Peterborough: Broadview Press, 2004, pp. 333

Perceived economic globalization and Europe's progressive
supranationalism have inspired a regional politics growth industry,
centred on Europe, which addresses how regions increasingly form and
operate trans-border institutions. Defining regionalism as the creation of
new partnerships or regions across jurisdictions, Memorial
University's Stephen Tomblin describes this book's thirteen
essays, divided almost evenly between Canadian and American scholars, as
an effort to overcome the lack of substantial research on North
America's cross-border regions (8). The book will satisfy most
readers seeking an update on the slowly growing regional initiatives
inside the Atlantic region (only sometimes including
Newfoundland) and the states of New England. But as the book's
contributors make clear, for all the ever-increasing trans-border truck
crossings and energy sales, most recently for Sable Island gas,
institutional cooperation between these provinces and states
remains limited.
Social-démocratie et mouvements ouvriers : la fin de
l'histoire?
Authors: Marier Patrik
Published: August 2005

Social-démocratie et mouvements ouvriers : la fin de
l'histoire?, Serge Denis, Montréal : Les éditions
Boréal, 2003, 226p.

Peu importe le pays, la relation entre le mouvement ouvrier et les
partis sociaux-démocrates est en crise. Ces derniers ont
cessé de promouvoir les revendications du mouvement ouvrier et ont
coupé les ponts avec leur base. Ce constat est au cœur de ce
livre qui débute avec le fameux “ winter of discontent
” britannique de 1978–79. Les récentes
décisions de certains partis sociaux-démocrates confirment
que la tendance se maintient. Serge Denis, auteur de plusieurs ouvrages
sur le syndicalisme, analyse la métamorphose des partis
sociaux-démocrates telle qu'elle est vécue par les
mouvements ouvriers.
International Environmental Policy: Interests and the Failure of the
Kyoto Process
Authors: Boardman Robert
Published: August 2005

International Environmental Policy: Interests and the Failure of the
Kyoto Process, Sonja Boehmer-Christiansen and Aynsley Kellow, Cheltenham:
Edward Elgar, 2002, pp. xi, 214

This valuable critique of climate change politics is written by two of
its leading observers. The authors—who variously describe themselves
as skeptical, dissident or agnostic about the scientific
issues—acknowledge that their views on the process are controversial
and unpopular. Why, they ask (1), was Kyoto so widely embraced? Unlike
other complex international agreements, the Protocol has been iconized. To
criticize it, they write, is to attack not only the “moral
crusade” (104) of environmentalism but also the global development
agenda (110). Behind the complaint is a well-crafted argument about the
inadequacies of science as a guide to policy, and a detailed account of
what they see as the politicization of climate science. The science, in
sum, has been “inescapably tied up with the play of interests from
the outset,” and “reflects, rather than simply drives,
politics” (6–7).
Governing Global Trade: International Institutions in Conflict and
Convergence
Authors: Duchesne Erick
Published: August 2005

Governing Global Trade: International Institutions in Conflict and
Convergence, Theodore H. Cohn, Burlington, VT: Ashgate, 2002, pp. xi,
329.

At a time when all eyes are riveted on the World Trade Organization
(WTO) and the ups and downs associated with its current round of
negotiation initiated in Doha, Qatar, in November 2001, Theodore
Cohn's latest publication provides a vivid reminder: The global
trading regime is made up of much more than the WTO. The GATT/WTO is
still pivotal in Cohn's diachronic overview of the evolution of the
global trade regime since the creation of the General Agreement on Tariff
and Trade (GATT) in 1947, but unlike several other studies on a similar
topic, the author untangles the relationship between the GATT/WTO and
other formal and informal international institutions, such as the
G7/G8, the Quadrilateral Group (Quad), the Organization for Economic
Co-operation and Development (OECD), the G77, and the United Nations
Conference on Trade and Development (UNCTAD). Each institution, as well as
the United States and the European Union, is given relatively equal
coverage in this notable study. Yet, as an indication that the
GATT/WTO is still primus inter pares, most chapters revolve
around the major negotiation rounds of the international organization.
Chapter 2 traces the origins and early period of the postwar trade regime
(1947–1962). Chapters 3 and 4 concentrate on the Kennedy
(1962–1972) and Tokyo (1973–1979) rounds of the GATT
respectively. Chapter 5 details the uncertainty associated with the
survival of the GATT (1980–1986). Chapters 6 and 7 focus on the
momentous Uruguay Round of the GATT (1986–1994), and chapter 8
highlights the post-Uruguay Round period (1995–2001).
Two Conceptions of Inequality and Natural Difference
Authors: Deslauriers Marguerite
Published: August 2005

Abstract.I argue in this paper that there are certain similarities between Catharine MacKinnon, on the one hand, and Mary Wollstonecraft and Jean Jacques Rousseau, on the other, in the conception of inequality and its origins. All three make two important claims that characterize their accounts of inequality: first, that inequality is not natural, and second, that the differences which are alleged to justify inequality are in fact produced by the inequality. These two claims distinguish one way of arguing for equality. I contrast this with another way of arguing for equality, one which acknowledges natural differences.

Résumé.Dans ce texte, je soutiens qu'il y a des similarités entre les conceptions de l'inégalité et de ses origines de Catharine MacKinnon d'une part et de Rousseau et Wollstonecraft d'autre part. Tous trois soutiennent deux thèses importantes qui caractérisent leur conception de l'inégalité : premièrement, l'inégalité n'est pas naturelle; deuxièmement, les différences qui sont invoquées pour justifier l'inégalité sont en fait le produit de cette inégalité. Ces deux positions sont distinctives d'une ligne d'argumentation défendant l'égalité. Je contraste cette ligne d'argumentation avec une seconde façon de défendre l'égalité qui diffère de la première en ce qu'elle reconnaît les différences naturelles.
Sapere Aude: Critical Ontology and the Case of Child
Development
Authors: Wong James
Published: August 2005

Abstract. This paper argues that Foucault's proposed
positive program of practical critique in his later work, which he calls
‘critical ontology,’ provides a response to his critics. The
goal of critical ontology is to “separate out, from the contingency
that has made us what we are, the possibility of no longer being, doing or
thinking what we are, do, or think.” However, it may be objected
that, since Foucault emphasizes going beyond contingencies, it appears
that he is guilty of committing a kind of genetic fallacy. I will defend
Foucault against such a charge by using concepts and practices in child
development as an illustration. The example of child development is
fitting for political theorizing because the development model of
childhood is now central to the practices and policies of healthcare
providers, social workers and educators. Such practices and policies aim
to enhance the abilities of individuals to be both citizens and autonomous
agents. Yet the effects of these policies on individuals are not always
positive. The paper concludes with a discussion of the implications of
critical ontology for practices grounded in the model of child
development.

Résumé. Cet article cherche à
démontrer que le programme positif de critique pratique que
Foucault propose dans ses derniers ouvrages, et qu'il qualifie
d'une “ontologie critique,” constitue une réponse
à ses détracteurs. Le but de cette ontologie critique est de
dégager “de la contingence qui nous a fait être ce que
nous sommes la possibilité de ne plus être, faire ou penser
ce que nous sommes, faisons ou pensons”. Néanmoins, il est
possible d'objecter que Foucault commet une sorte d'erreur
génétique, puisqu'il insiste sur la
nécessité de dépasser les contingences. Je cherche
à defendre Foucault contre cette accusation en utilisant les
concepts et pratiques du développement des enfants comme
illustration. L'exemple du développement des enfants convient
à la théorie politique puisque le modèle
d'aménagement de l'enfance est maintenant au coeur des
pratiques et des politiques de ceux qui travaillent dans les secteurs de
la santé, de l'aide social, et de l'éducation.
Telles pratiques et politiques ont comme but d'accroître la
capacité des individus d'agir en même temps comme
citoyens et des êtres autonomes. Pourtant, les effets de ces
politiques sur des individus ne sont pas toujours
bénéfiques. L'article se conclut par une analyse des
implications d'une ontologie critique pour des pratiques
fondées sur le modèle du développement des
enfants.
Phronesis, Democracy and Technology
Authors: Tabachnick David E.
Published: August 2005

Abstract.This essay identifies a problem with the phronesis revival. Some revivalists argue that phronesis can serve as a response to the homogenizing influence of technology, maintaining the particulars of individuals and communities. However, by their own argument, technology denies the conditions or “educational backdrop” that the development and practice of phronesis requires.

Résumé.Cet essai identifie le problème de la renaissance du phronesis. Ces révisionnistes considèrent que le phronesis peut serviez de réponse à l'influence homogénéifiante de la technologie. Ils maintiennent la spécificité des individus et des communautés. Cependant, selon leur propre argumentation, la technologie nie les conditions ou la base éducationnelle nécessaires au développement et à la pratique du phronesis.
Démocratie délibérative et sécession
Authors: Courtois Stéphane
Published: August 2005

Résumé.L'auteur entend défendre dans cet essai une conception de la sécession qu'il appelle délibérative et la justifier par rapport à d'autres théories concurrentes de la sécession. En l'absence d'un encadrement juridique clair et rigoureux des cas de sécession, de plus en plus nombreux, qui échappent aux situations de domination coloniale prévues par le droit international, la question se pose en effet de savoir s'il n'existe pas d'autres moyens de les résoudre dans des conditions pacifiques. L'auteur soutient que la démocratie délibérative pourrait offrir de tels moyens. Le but de l'article est d'examiner dans quelles conditions et à l'intérieur de quelles limites.

Abstract.In this article, the author aims at supporting a deliberative conception of secession and at justifying it against other rival theories. In the absence of clear and rigorous legal regulations of more and more numerous cases of secession going beyond the situations of colonial domination already covered by the international law, the question arises as to whether other means for their pacific solution are available. The author contends that deliberative democracy could provide such a means and examines in what conditions and within what limits this could be achieved.
Mid vowel fronting in Ukrainian
Authors: Rubach Jerzy
Published: August 2005

This article investigates the process of o-fronting in Ukrainian and claims that it should be analysed as an effect of PAL-e, a constraint mandating that the consonant and the vowel agree in backness. The operation of PAL-e is opaque, due to the interaction with a depalatalisation process applying before [ε]. The analysis establishes four points of theoretical interest. First, from a typological perspective, PAL-e parallels PAL-i, postulated by Rubach (2000a) for Russian, which strengthens the contention that PAL constraints should be stated as agreement constraints that bring under the same denominator the palatalisation of consonants and the fronting of vowels. Second, the opacity of o-fronting cannot be analysed by appealing to MAX[F] constraints. Third, sympathy theory cannot handle the data either. Fourth, Optimality Theory must be modified to admit derivational levels.
Vug waves: A mechanism for coupled rock deformation and fluid migration
Authors: Phipps Morgan Jason , Holtzman Benjamin K.
Published: August 2005

Vug waves are a joint deformation/fluid‐migration mechanism in which a rock deforms by the movement of a penny‐shaped, fluid‐filled crack dislocation across a plane of shear, with migration of the crack and fluid driven by the release of elastic shear strain energy. Vug waves (here so named because a “vug” is a hole in the Earth and “wave” implies that it moves) may provide an effective means for (1) rapidly migrating and focusing relatively isolated batches of melt to mid‐ocean ridge axes, (2) a possible origin for weakness and rheological and seismic anisotropy of Earth's asthenosphere, and (3) the origin of large, weak shear zones within Earth's mantle and crust. The existence of vug waves would also imply that in many geologic environments the strain‐energy release from migrating a fluid‐filled crack through a stressed solid may play a larger role in shaping fluid migration than the buoyancy of the fluid with respect to its host rock.
Heliospheric energetic particle observations during the October–November 2003 events
Authors: Lario D. , Decker R. B. , Livi S. , Krimigis S. M. , Roelof E. C. , Russell C. T. , Fry C. D.
Published: August 2005

The intense level of solar activity recorded from 19 October to 12 November 2003 led to unusually high energetic particle intensities observed throughout the heliosphere. The fleet of spacecraft distributed in the inner and outer heliosphere offers us the opportunity to study both the effects of these events in different regions of the heliosphere and the evolution of the energetic particle intensities measured at different heliocentric radial distances. Observations at 1 AU by the ACE and GOES‐11 spacecraft show multiple particle intensity enhancements associated with individual injections of solar energetic particles (SEPs) and with the arrival of shocks driven by coronal mass ejections (CMEs), resulting in a long time interval (∼40 days) of elevated low‐energy (<1 MeV) ion and near‐relativistic (<315 keV) electron intensities. Observations from the Ulysses spacecraft at 5.2 AU, 6° north of the ecliptic, and 120–90° west of the Earth also showed elevated low‐energy ion and near‐relativistic electron intensities for more than ∼40 days that were modulated by the effects of recurrent corotating interaction regions (CIRs) and the passage of a fast interplanetary coronal mass ejection (ICME). The Cassini spacecraft at 8.7 AU, 3° south of the ecliptic, and 75–35° west of the Earth saw an intense low‐energy ion and near‐relativistic electron event in association with the passage of an enhanced magnetic field structure formed by the compression of transient solar wind flows and CIRs. The prompt component of the SEP event at Cassini was largely reduced due to the modulating effect of intervening transient flows propagating between the Sun and the spacecraft. The Voyager‐2 spacecraft at 73 AU and 25° south of the ecliptic did not observe these events until April 2004. The arrival of a merged interaction region (MIR) at Voyager‐2 produced a ∼70‐day period with elevated <17 MeV proton and <60 keV electron intensities. Particle fluences computed over the duration of the events at each spacecraft show a radial dependence that decays more slowly than that expected from a simple model assuming adiabatic cooling of an isotropic particle population uniformly distributed in a shell symmetrically expanding at the solar wind speed. Although the SEP events were observed throughout the heliosphere, both (1) the solar particle injections occurring at different times and longitudes, and (2) the marked differences in the interplanetary stream structures propagating toward different longitudes resulted in distinct time‐intensity histories at each spacecraft, and therefore periods with equal particle intensities were not observed by this fleet of spacecraft.
A fast radiative transfer model for simulating high‐resolution absorption bands
Authors: Duan Minzheng , Min Qilong , Li Jiangnan
Published: August 2005

A fast radiative transfer model has been developed for simulating high‐resolution absorption bands. The first scattering radiance is calculated accurately by using the higher number of layers and streams for all required wave number grids. The multiple‐scattering component is extrapolated and/or interpolated from a finite set of calculations in the space of two integrated gaseous absorption optical depths to the wave number grids: a double‐kapproach. The double‐kapproach substantially reduces the error due to the uncorrelated nature of overlapped absorption lines. More importantly, these finite multiple‐scattering radiances at specifick(λi) values are computed with a reduced number of layers and/or streams in the forward radiative transfer model. To simulate an oxygen A‐band spectrum, 28 calculations of radiative transfer are needed to achieve an accuracy of 0.5% for most applications under all‐sky conditions and 1.5% for the most challenging multiple‐layer cloud systems (99% of spectrum below 0.5%). This represents a thousandfold time reduction in the standard forward radiative transfer calculation.
Estimating the economic benefits of maintaining residential lake levels at an irrigation reservoir: A contingent valuation study
Authors: Loomis John , Smith Adam , Huszar Paul
Published: August 2005

The contingent valuation method (CVM) was used to estimate homeowners' willingness to pay for water leasing to maintain stable lake levels at an irrigation reservoir in a residential neighborhood. A binary logit model was used to analyze households' voter referendum responses for maintaining the lake level. The median willingness to pay (WTP) was found to be $368 per year for lakefront residents and $59 per year for off‐lake residents. The median WTP for lakefront residents was significantly different from off‐lake residents at the 90% confidence level. Using the median WTP for lakefront and nonlakefront residents, we found that the increase in homeowner association fees would generate approximately $43,000, enough money to lease sufficient water to reach the target higher lake level in a normal water year.
Aeromagnetic data provide new insights on the volcanism and tectonics of Vulcano Island and offshore areas (southern Tyrrhenian Sea, Italy)
Authors: De Ritis Riccardo , Blanco‐Montenegro Isabel , Ventura Guido , Chiappini Massimo
Published: August 2005

The active Vulcano Island (Southern Tyrrhenian Sea) represents the southernmost portion of a NW‐SE elongated volcanic ridge that includes also Lipari and Salina islands. The ridge is affected by a regional, NW‐SE to N‐S striking fault system. The elaboration and analysis of data from three high‐resolution aeromagnetic surveys carried out between 1999 and 2004 on Vulcano and offshore allow us to recognize high intensity magnetic anomalies related to volcanic centers/conduits or shallow intrusions. Previously unreported offshore submarine vents have been also recognized. Some of them may correspond with source areas of outcropping exotic pyroclastics on Vulcano. The spatial analysis of the recognized magnetic anomalies and volcanic structures shows that they are preferably aligned along the strikes of the main regional faults that affect the volcanic ridge. Submarine volcanic conduits revealed by the aeromagnetic survey might represent potential sources for future submarine, effusive or explosive activity.
Dopamine Storage Capacity in Caudate and Putamen of Patients with Early Parkinson's Disease: Correlation with Asymmetry of Motor Symptoms
Authors: Kumakura Yoshitaka , Gjedde Albert , Danielsen Erik H , Christensen Søren , Cumming Paul
Published: August 2005

Conventional graphical analysis of positron emission tomography (PET) recordings of the cerebral uptake of the DOPA decarboxylase substrate [18F]fluorodopa (FDOPA) assumes irreversible trapping of [18F]fluorodopamine formed in the brain. However, 4-h long PET recordings allow the estimation of a rate constant for elimination of [18F]fluorodopamine from the brain ( kloss), from which can be calculated an effective distribution volume ( EDV1), which is an index of [18F]fluorodopamine storage capacity. We earlier developed a method employing 2-h long FDOPA recordings for the estimation of kloss and EDV, here defined as EDV2. This method is based on subtraction of the calculated brain concentrations of the FDOPA metabolite O-methyl-FDOPA, rather than the subtraction of the entire radioactivity in a reference region. We now extend this method for the parametric mapping of these parameters in the brain of healthy aged volunteers and patients with Parkinson's disease (PD), with asymmetry of motor symptoms. For parametric mapping, we use a novel application of a multilinear solution for the two-tissue compartment FDOPA model. We also test a new application of the Logan graphical analysis for mapping of the FDOPA distribution volume at equilibrium. The estimates of kloss and EDV2 were more sensitive for the discrimination of biochemical abnormality in the putamen of patients with early PD relative to healthy aged subjects, than was the conventional net influx estimate. Of the several methods, multilinear estimates of EDV2 were most sensitive for discrimination of PD and normal putamen. However, kloss was most sensitive for detecting biochemical asymmetry in the putamen of PD patients, and only kloss also detected in the caudate of PD patients a decline in the retention of [18F]fluorodopamine relative to healthy aged control subjects.
Effect of Pt on agglomeration and Ge out diffusion in Ni(Pt) germanosilicide
Authors: Jin L. J. , Pey K. L. , Choi W. K. , Fitzgerald E. A. , Antoniadis D. A. , Pitera A. J. , Lee M. L. , Chi D. Z. , Rahman Md. A. , Osipowicz T. , Tung C. H.
Published: August 2005

The effect of Pt alloy in Ni(Pt∼5 and 10 at. %) on the agglomeration and Ge out diffusion in nickel germanosilicide formed on Si0.75Ge0.25(100) has been studied. A remarkable improvement in the agglomeration behavior with increasing Pt atomic percentage is observed by sheet resistance measurements while still maintaining Ni(Pt) monogermanosilicide phase between 400 and 800 °C. Ge out diffusion from the monogermanosilicide grains has been suppressed up to a temperature of 700 °C with the addition of Pt, evident by x-ray diffraction and micro-Raman spectroscopy. In addition, that improvement of surface morphology and suppression of Ge out diffusion with increasing Pt atomic percent is also confirmed by Rutherford backscattering and cross-sectional transmission electron microscopy. The improved morphology and agglomeration are explained by a grain-boundary model which includes kinetic effects. The suppression of Ge out diffusion from the germanosilicide grains is attributed to reduced atomic diffusion and the presence of stronger Pt–Si and Pt–Ge bonds due to the addition of Pt.
Ignition dynamics and activation energies of metallic thermites: From nano- to micron-scale particulate composites
Authors: Hunt Emily M. , Pantoya Michelle L.
Published: August 2005

Ignition behaviors associated with nano- and micron-scale particulate composite thermites were studied experimentally and modeled theoretically. The experimental analysis utilized a CO2 laser ignition apparatus to ignite the front surface of compacted nickel (Ni) and aluminum (Al) pellets at varying heating rates. Ignition delay time and ignition temperature as a function of both Ni and Al particle size were measured using high-speed imaging and microthermocouples. The apparent activation energy was determined from this data using a Kissinger isoconversion method. This study shows that the activation energy is significantly lower for nano- compared with micron-scale particulate media (i.e., as low as 17.4 compared with 162.5kJ∕mol, respectively). Two separate Arrhenius-type mathematical models were developed that describe ignition in the nano- and the micron-composite thermites. The micron-composite model is based on a heat balance while the nanocomposite model incorporates the energy of phase transformation in the alumina shell theorized to be an initiating step in the solid-solid diffusion reaction and uniquely appreciable in nanoparticle media. These models were found to describe the ignition of the Ni∕Al alloy for a wide range of heating rates.
Avoiding negative populations in explicit Poisson tau-leaping
Authors: Cao Yang , Gillespie Daniel T. , Petzold Linda R.
Published: August 2005

The explicit tau-leaping procedure attempts to speed up the stochastic simulation of a chemically reacting system by approximating the number of firings of each reaction channel during a chosen time increment τ as a Poisson random variable. Since the Poisson random variable can have arbitrarily large sample values, there is always the possibility that this procedure will cause one or more reaction channels to fire so many times during τ that the population of some reactant species will be driven negative. Two recent papers have shown how that unacceptable occurrence can be avoided by replacing the Poisson random variables with binomial random variables, whose values are naturally bounded. This paper describes a modified Poisson tau-leaping procedure that also avoids negative populations, but is easier to implement than the binomial procedure. The new Poisson procedure also introduces a second control parameter, whose value essentially dials the procedure from the original Poisson tau-leaping at one extreme to the exact stochastic simulation algorithm at the other; therefore, the modified Poisson procedure will generally be more accurate than the original Poisson procedure.
Magnetoresistance devices based on single-walled carbon nanotubes
Authors: Hod Oded , Rabani Eran , Baer Roi
Published: August 2005

We demonstrate the physical principles for the construction of a nanometer-sized magnetoresistance device based on the Aharonov-Bohm effect [Phys. Rev. 115, 485 (1959)]. The proposed device is made of a short single-walled carbon nanotube (SWCNT) placed on a substrate and coupled to a tip/contacts. We consider conductance due to the motion of electrons along the circumference of the tube (as opposed to the motion parallel to its axis). We find that the circumference conductance is sensitive to magnetic fields threading the SWCNT due to the Aharonov-Bohm effect, and show that by retracting the tip/contacts, so that the coupling to the SWCNT is reduced, very high sensitivity to the threading magnetic field develops. This is due to the formation of a narrow resonance through which the tunneling current flows. Using a bias potential the resonance can be shifted to low magnetic fields, allowing the control of conductance with magnetic fields of the order of 1 T.
Pressure-induced hexagonal phase in a ternary microemulsion system composed of a nonionic surfactant, water, and oil
Authors: Nagao Michihiro , Seto Hideki , Ihara Daisuke , Shibayama Mitsuhiro , Takeda Takayoshi
Published: August 2005

The pressure-induced phase transition in a microemulsion, consisting of pentaethylene glycol mono-n-dodecyl ether, water, and n-octane, was investigated by means of small-angle neutron scattering. A pressure-induced phase transition from a lamellar structure to a hexagonal structure was observed. The temperature-pressure phase boundary shows a positive slope with dT∕dP∼0.09K∕MPa. The structure unit of the high-pressure hexagonal phase was an oil-in-water cylinder with the membrane thickness of 15.5 Å, identical to the low-temperature hexagonal phase. Pressurizing was found to have the same effect by decreasing temperature. This behavior was satisfactorily explained with the pressure dependence of the spontaneous curvature of surfactant membranes. That is, the volume change of surfactant tails plays a dominant role in the structure change of the microemulsion with applying pressure.
Photodissociation dynamics of pyridine
Authors: Lin Ming-Fu , Dyakov Yuri A. , Tseng Chien-Ming , Mebel Alexander M. , Hsien Lin Sheng , Lee Yuan T. , Ni Chi-Kung
Published: August 2005

Photodissociation of pyridine, 2,6-d2-pyridine, and d5-pyridine at 193 and 248nm was investigated separately using multimass ion imaging techniques. Six dissociation channels were observed at 193nm, including C5NH5→C5NH4+H (10%) and five ring opening dissociation channels, C5NH5→C4H4+HCN, C5NH5→C3H3+C2NH2, C5NH5→C2H4+C3NH, C5NH5→C4NH2+CH3 (14%), and C5NH5→C2H2+C3NH3. Extensive H and D atom exchanges of 2,6-d2-pyridine prior to dissociation were observed. Photofragment translational energy distributions and dissociation rates indicate that dissociation occurs in the ground electronic state after internal conversion. The dissociation rate of pyridine excited by 248-nm photons was too slow to be measured, and the upper limit of the dissociation rate was estimated to be 2×103s−1. Comparisons with potential energies obtained from ab initio calculations and dissociation rates obtained from the Rice-Ramsperger-Kassel-Marcus theory have been made.
Electronic properties of a-CNx thin films: An x-ray-absorption and photoemission spectroscopy study
Authors: Ray S. C. , Pao C. W. , Chiou J. W. , Tsai H. M. , Jan J. C. , Pong W. F. , McCann R. , Roy S. S. , Papakonstantinou P. , McLaughlin J. A.
Published: August 2005

The electronic properties of amorphous carbon nitride were studied by x-ray-absorption near-edge structure (XANES) and valence-band photoelectron spectroscopy (PES). The nitrogen incorporation was found to induce graphitization, as evidenced by an increase of the sp2 cluster in C and N K-edge XANES spectra. The structure is found to be similar to pyridine. Hybridized C–N bond lengths were determined from the position of the σ* resonance of XANES spectra and the obtained results suggest sp2 hybridization. A valence-band PES spectrum showed that the p-π band became more intense than the p-σ band upon higher at. % nitrogen addition, which confirmed the role played by the π bonds in controlling the electronic structure of a-CNx films.
Near-surface density of ion-implanted Si studied by Rutherford backscattering and total-reflection x-ray fluorescence
Authors: Klockenkämper R. , Becker M. , von Bohlen A. , Becker H. W. , Krzyzanowska H. , Palmetshofer L.
Published: August 2005

The implantation of ions in solids is of high technical relevance. The different effects within the solid target caused by the ion bombardment can be investigated by depth profiling of near-surface layers. As and Co ions were implanted in Si wafers: As ions with a fluence of 1×1017∕cm2 and an energy of 100keV and Co ions with 1×1016∕cm2 at 25keV. Subsequently depth profiling was carried out by Rutherford backscattering spectrometry as well as by total-reflection x-ray fluorescence analysis which was combined with differential weighing and interferometry after repeated large-surface sputter etching. Over and above the amorphization of the Si crystal, two other essential effects were observed: (i) a swelling or expansion of the original Si crystal in the near-surface region, in particular in the case of the As implantation, and (ii) a shrinking or compression of the Si crystal for deeper sublayers especially distinct for the Co implantation. On the other hand, a high surface enrichment of implanted ions was found for the As implantation while only a low surface concentration was detected for the Co implantation.
Nucleation mechanism of the seed of tetrapod ZnO nanostructures
Authors: Ronning C. , Shang N. G. , Gerhards I. , Hofsäss H. , Seibt M.
Published: August 2005

Tetrapod zinc oxide (T-ZnO) nanorods have been synthesized by evaporation and recondensation of metallic Zn under ambient conditions. The total sizes of the T-ZnO nanostructures range from 300nmto15μm with leg diameters of about 30to650nm, depending on the deposition temperature. A detailed high-resolution electron microscopy analysis showed that the center core of T-ZnO nanorods consists of four hexagonal grains with a twinlike relation. The nucleation and growth mechanism has been generated on the basis of energy considerations during a phase transition from a fullerenelike ZnO cluster to a nanometer-sized tetrahedron, which is directly visible in our high-resolution transmission electron microscopy investigations.
A sample holder design for high temperature measurements in superconducting quantum interference device magnetometers
Authors: Bedanta S. , Petracic O. , Aderholz M. , Kleemann W.
Published: August 2005

A sample holder made of fused silica, suitable for performing precise measurements of the magnetic moment at elevated temperatures (300–700 K) using a superconducting quantum interference device magnetometer, is presented. The sample holder has a simple design, is easily fabricated and capable of multiple usage. Test measurements of the magnetic moment of a granular multilayer sample [Co80Fe20(1.6nm)∕Al2O3(3nm)]9 are performed and corrected for the background data from the empty sample holder.
Study of very low airborne particle count in clean-unit system platform
Authors: Kaiju Hideo , Kawaguchi Nobuyoshi , Ishibashi Akira
Published: August 2005

Cleanliness of a clean-unit system platform consisting of multiply connectable clean boxes with feedback loop is studied and the time dependence of particle count is clarified experimentally and theoretically in order to achieve highly clean environment. Based on this analysis, we have demonstrated airborne particle counts as low as 5particles∕ft3 for the diameter of 0.1μm, 0.6 particles for 0.2μm, and 0.01 particles for 0.5μm by a reduction of particle density coming out from the in-wall in the system. The clean-unit system with feedback loop can serve as a platform for cross-disciplinary experiments and production for fields such as nanotechnologies and biotechnologies.
16-channel magnetoresistive scanner for magnetic surface imaging
Authors: Cano M. E. , Martínez J. C. , Bernal-Alvarado J. , Sosa M. , Córdova T.
Published: August 2005

A multichannel scanning system for magnetic surface imaging composed of 16 magnetoresistive sensors has been developed. A gray scale, from 0 to 255, was used to represent the magnetic signal detected by each sensor when the sample was moved above the scanner. Measurements and calibration were performed using magnetic surfaces with different shapes and samples with similar profiles, but different magnetization intensities. The system was sufficiently sensitive to detect gradients and discontinuities on the magnetic map. The 16 channel images were numerically processed to obtain a smooth representation of the magnetic map using the LabView™ Image Vision package.
Evaluation of a mutual impedance probe to search for water ice in the Martian shallow subsoil
Authors: Del Vento Davide , Vannaroni Giuliano
Published: August 2005

This work analyzes the performance of a mutual impedance probe used to measure the complex permittivity of a soil, and detect the presence of water ice buried in the subsurface. The sensor consists of four electrodes deployed above the ground, equally spaced along a straight line array. The quadrupole accuracy has been evaluated through a suitable error analysis which considered the errors associated with the electronics used to measure the mutual impedance of the system, and the position uncertainties of the electrode array. It has been found that the quadrupole accuracy is mainly limited by the electrode positioning. In particular, the electrode vertical misplacements perturb the measurements much more than the horizontal ones. As a case study, a two-layers soil with the deeper stratum containing 20% of water ice at 190 K, which could represent a realistic Martian soil scenario, has been analyzed. It was found that the ice detection requires an electrode vertical position accuracy better than 0.001 times the interelectrode distance. This requirement is far too difficult to be achieved in a fully automated rover mission. Such a conclusion poses significant doubts about the feasibility of projects which foresee the use of electric quadrupoles to detect water ice in the Martian subsoil.
Apolipoprotein E allele-dependent pathogenesis: A model for age-related retinal degeneration
Authors: Malek G. , Johnson L. V. , Mace B. E. , Saloupis P. , Schmechel D. E. , Rickman D. W. , Toth C. A. , Sullivan P. M. , Rickman C. Bowes
Published: August 2005

Age-related macular degeneration (AMD) is a late-onset, multifactorial, neurodegenerative disease of the retina and the leading cause of irreversible vision loss in the elderly in the Western world. We describe here a murine model that combines three known AMD risk factors: advanced age, high fat cholesterol-rich (HF-C) diet, and apolipoprotein E (apoE) genotype. Eyes of aged, targeted replacement mice expressing human apoE2, apoE3, or apoE4 and maintained on a HF-C diet show apoE isoform-dependent pathologies of differential severity. ApoE4 mice are the most severely affected. They develop a constellation of changes that mimic the pathology associated with human AMD. These alterations include diffuse sub-retinal pigment epithelial deposits, drusenoid deposits, thickened Bruch's membrane, and atrophy, hypopigmentation, and hyperpigmentation of the retinal pigment epithelium. In extreme cases, apoE4 mice also develop marked choroidal neovascularization, a hallmark of exudative AMD. Neither age nor HF-C diet alone is sufficient to elicit these changes. We document choroidal neovascularization and other AMD-like ocular pathologies in an animal model that exploits known AMD risk factors. The model is additionally attractive because it is not complicated by invasive experimental intervention. Our findings in this model implicate the human apoE E4 allele as a susceptibility gene for AMD and support the hypothesis that common pathogenic mechanisms may underlie AMD and Alzheimer's disease.
False beliefs about fattening foods can have healthy consequences
Authors: Bernstein Daniel M. , Laney Cara , Morris Erin K. , Loftus Elizabeth F.
Published: August 2005

We suggested to 228 subjects in two experiments that, as children, they had had negative experiences with a fattening food. An additional 107 subjects received no such suggestion and served as controls. In Experiment 1, a minority of subjects came to believe that they had felt ill after eating strawberry ice cream as children, and these subjects were more likely to indicate not wanting to eat strawberry ice cream now. In contrast, we were unable to obtain these effects when the critical item was a more commonly eaten treat (chocolate chip cookie). In Experiment 2, we replicated and extended the strawberry ice cream results. Two different ways of processing the false suggestion succeeded in planting the false belief and producing avoidance of the food. These findings show that it is possible to convince people that, as children, they experienced a negative event involving a fattening food and that this false belief results in avoidance of that food in adulthood. More broadly, these results indicate that we can, through suggestion, manipulate nutritional selection and possibly even improve health.
Early Spindle Assembly inDrosophilaEmbryos: Role of a Force Balance Involving Cytoskeletal Dynamics and Nuclear Mechanics
Authors: Cytrynbaum E. N. , Sommi P. , Brust-Mascher I. , Scholey J. M. , Mogilner A.
Published: August 2005

Mitotic spindle morphogenesis depends upon the action of microtubules (MTs), motors and the cell cortex. Previously, we proposed that cortical- and MT-based motors acting alone can coordinate early spindle assembly in Drosophila embryos. Here, we tested this model using microscopy of living embryos to analyze spindle pole separation, cortical reorganization, and nuclear dynamics in interphase-prophase of cycles 11-13. We observe that actin caps remain flat as they expand and that furrows do not ingress. As centrosomes separate, they follow a linear trajectory, maintaining a constant pole-to-furrow distance while the nucleus progressively deforms along the elongating pole-pole axis. These observations are incorporated into a model in which outward forces generated by zones of active cortical dynein are balanced by inward forces produced by nuclear elasticity and during cycle 13, by Ncd, which localizes to interpolar MTs. Thus, the force-balance driving early spindle morphogenesis depends upon MT-based motors acting in concert with the cortex and nucleus.