bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical and sensory analysis of strawberry flavoured yogurt supplemented with an algae oil emulsion
Authors: Chee Celia P , Gallaher Jason J , Djordjevic Darinka , Faraji Habibollah , McClements D Julian , Decker Eric A , Hollender Ruth , Peterson Devin G , Roberts Robert F , Coupland John N
Published: June 2005

A yogurt mix (2 g fat and 17 g solids/100 g) was supplemented with an algae oil emulsion to provide 500 mg ω-3 fatty acids per 272 g serving of yogurt white mass. The emulsion was added to the yogurt mix either before or after the homogenization step and prior to pasteurization. It was then flavoured with a strawberry fruit base and fermented and stored for up to three weeks. The oxidative deterioration of the products was determined by hydroperoxide measurements and by trained and consumer sensory evaluations. The hydroperoxide content of the supplemented yogurts increased over the storage treatment and was unaffected by the stage of addition. The trained panel could distinguish a stronger fishy flavour in both of the supplemented yogurts after 22 days storage, but the consumer panel rated both control and supplemented samples similarly, as ‘moderately liked’.
Pursuing Social Justice or Social Cohesion?: Coercion in Street Homelessness Policies in England
Authors: FITZPATRICK SUZANNE , JONES ANWEN
Published: June 2005

This article contends that the New Labour government's current policies on street homelessness in England prioritise ‘social cohesion’ over ‘social justice’ objectives. While the government has implemented substantial improvements in services for street homeless people in recent years, and has achieved a significant reduction in the numbers sleeping rough, a strong ‘social control’ emphasis has now emerged in this policy agenda, as those remaining on the streets are increasingly viewed as an ‘anti-social behaviour’ problem. The article argues that coercive or forceful measures aimed at street homeless people cannot be justified from a social justice perspective, unless it can be demonstrated that they have a positive impact on the welfare of this marginalised group. The evidence presently available, although not definitive, indicates that such measures are more likely to undermine than promote the well-being of street homeless people.
Promoting Social Change: The Experience of Health Action Zones in England
Authors: BAULD LINDA , JUDGE KEN , BARNES MARIAN , BENZEVAL MICHAELA , MACKENZIE MHAIRI , SULLIVAN HELEN
Published: June 2005

When New Labour came to power in the UK in 1997 it brought with it a strong commitment to reducing inequality and social exclusion. One strand of its strategy involved a focus on area-based initiatives to reduce the effects of persistent disadvantage. Health Action Zones (HAZs) were the first example of this type of intervention, and their focus on community-based initiatives to tackle the wider social determinants of health inequalities excited great interest both nationally and internationally. This article draws on findings from the national evaluation of the initiative. It provides an overview of the HAZ experience, and explores why many of the great expectations associated with HAZs at their launch failed to materialise. It suggests that, despite their relatively limited impact, it is best to consider that they made a good start in difficult circumstances rather than that they failed. As a result there are some important lessons to be learned about the role of complex community-based interventions in tackling seemingly intractable social problems for policy-makers, practitioners and evaluators.
Social programs are complex undertakings. They are an amalgam of dreams and personalities, rooms and theories, paper clips and organisational structure, clients and activities, budgets and photocopies, and great intentions. (Weiss, 1998: 48)
From Hospital Contributory Schemes to Health Cash Plans: The Mutual Ideal in British Health Care after 1948
Authors: GORSKY MARTIN , MOHAN JOHN , WILLIS TIM
Published: June 2005

The article traces the post-war history of the British hospital contributory schemes, which had developed during the inter-war years to the point where, through the accumulation of small weekly contributions from a mass membership, they provided substantial proportions of hospital income. A minority of contributory schemes remained in existence post-1948, but their subsequent development has received little attention. Some evolved into provident associations offering private health insurance; others remained committed to the provision of low-cost benefits to a blue-collar clientele, and continued to be known as hospital contributory schemes. This article outlines the principal features of the contributory schemes' contemporary history. We first explore why many schemes decided to continue in existence. The next section uses national and individual scheme records to delineate the market niche which they captured and to investigate their role in post-war health provision, relative to the state system. In particular we trace the decline of convalescent home benefit, and the gradual trend towards a more uniform benefit package, of which optical and dental grants were the most popular. We then survey patterns of membership and account for the main trends in support for cash plan products since 1950. Finally, we ask to what extent the schemes were able to retain their character as a ‘movement’ with distinctive mutualist and charitable features, particularly in the more competitive environment of the later twentieth century.
Hamlet: voice, music, sound
Authors: JOHNSON BRUCE
Published: June 2005

The literary canonisation of Hamlet means that it is now most frequently encountered as a printed text. This crucially reconfigures its character, since Shakespeare wrote for sound, not print, and for an audience habituated to finely nuanced auditory semiotics. Hamlet generates its own soundscape as the major bearer of meanings. Apart from dialogue, its complex repertoire of auditory effects includes instrumental music and song. If we examine the play as an acoustic experience, we can situate it more ‘soundly’ in its epoch, and perhaps also reinterpret its puzzles, most notably Hamlet's procrastination, an issue that only began to be raised by later critics working in a more print-oriented era. If we reclaim the sonic dimensions of the play, his inexplicable indecisiveness may be seen as the point, not the puzzle, of the play, and a metaphor of the liminal epistemology of Shakespeare's age.
García Márquez, macondismo, and the soundscapes of vallenato
Authors: OCHOA ANA MARÍA
Published: June 2005

This article is about the role of García Márquez and particularly macondismo as an ideology in establishing the canonic validity of vallenato as a folk genre from the Colombian Caribbean. García Marquez' chronicles of the early 1950s are seen as foundational texts on the aesthetics and value of vallenato; texts which influence subsequent writings on the topic. One of the main topics explored is how these texts acquire canonic validity through the success of One Hundred Years of Solitude. It is then that macondismo – the Latin Americanist celebration of magical realism – becomes an interpretive metaphor for Colombia and vallenato music becomes the sonorous emblem of this metaphor. This occurs through García Marquez' writings, his multiple interventions in Colombian vallenato festivals, and the way vallenato is subsequently taken by a journalistic elite of the country as representing a macondian sonorous paradigm. The article explores how these different elements coalesce in constructing a genealogy of aurality for vallenato, setting the parameters of its interpretive significance through multiple processes of folklorisation of the genre.
Blues, criticism, and the signifying trickster
Authors: SMITH AYANA
Published: June 2005

Scholars in the field of literary theory have defined clearly the role of signifying in African-American literature. This article identifies one aspect of the signifying tradition and its influence on the early blues tradition. Since the Signifying Monkey is the ultimate trickster in the African-American narrative tradition, this article presents evidence for considering the blues singer as a trickster figure at several different levels. First, the singer identifies with the trickster's character traits through pseudo-autobiographical content in song narratives, particularly in expressing socially aggressive or unacceptable exploits. Second, the trickster figure can be perceived as the singer's alter ego, as in songs about the boll weevil and similar folk characters. Third, the topics or tropes associated with crossroads and railways, used frequently in blues texts, relate to the liminal nature of Esu-Elegbara (the African ancestor of the Signifying Monkey), who embodies the boundary between the word and its (mis)interpretation.
To Be or Not to Bop: Jack Kerouac's On The Road and the culture of bebop and rhythm 'n' blues
Authors: Hopkins David
Published: June 2005

The appearance of On the Road in 1957 signalled the emergence of a new movement in American literature, soon to be called the Beat Generation (Kerouac 1957). Along with Allen Ginsberg's ‘Howl’ of 1956, Kerouac's work brought a new awareness of an intellectual counter-culture bubbling under the conservative surface of 1950s America. The content of these writers' poetry and prose, with its open and honest depiction of hetero-, homo-, and bisexual activity, drug abuse, petty crime, and social deviance was enough to create a sensation, but it is the style that gives the works their permanence and interest today. Kerouac himself used the term ‘bop prose’ to describe his efforts to reform fiction along the lines of avant-garde jazz, where immediacy of expression and technical fluency combine to open new possibilities, supposedly not present in more traditional methods of composition.
The Epistemological Argument against Desert
Authors: MORIARTY JEFFREY
Published: June 2005

Most contemporary political philosophers deny that justice requires giving people what they deserve. According to a familiar anti-desert argument, the influence of genes and environment on people's actions and traits undermines all desert-claims. According to a less familiar – but more plausible – argument, the influence of genes and environment on people's actions and traits undermines some desert-claims (or all desert-claims to an extent). But, it says, we do not know which ones (or to what extent). This article examines this ‘epistemological’ argument against desert. It gives reason to believe that it fails, emphasizing the importance of justice relative to efficiency and attempting to construct a practical way of measuring desert.
Mechanisms to Prevent Infection: Invasive Monitoring
Authors: Burton Aileen
Published: June 2005

Intravenous therapy is an essential part of clinical care used in a wide variety of healthcare settings. Thus, intravenous catheters have become indispensable to clinical practice. However, catheter related infections are a major source of morbidity and mortality with rates as high as 10% to 20%. Current guidance recommends a number of strategies to reduce the incidence of catheter-related infections. These include skin preparation, avoiding glove contamination when handling and inserting catheters and the choice of material used.

Strategies to prevent infection need to change and develop to reflect the advances in technology and delivery of healthcare.
Going Dutch: Anaesthetising in the Netherlands and Other Issues
Authors: Cowan D. T.
Published: June 2005

This paper discusses the role, responsibilities and practices of anaesthetic practitioners in the Netherlands in relation to their counterparts in the United Kingdom (UK), these practitioners representing an important yet overlooked section of the health care workforce. This takes place in the context of the UK National Health Service (NHS) modernisation agenda and the European Commission's (EC) aim to enhance the mobility of health care staff throughout the European Union (EU) through standardisation of variations in qualifications, skill levels, methods and working practices (Bologna, 1999; Lisbon Strategy, 2000; EHTAN, 2005).

It is clear that significant disparities remain between anaesthetic practitioners in both countries and that we need to explore ways of arriving at compatibility between the different grades. However, this does not currently appear to be happening at EU level. Despite the huge responsibilities on these practitioners, this sector of the EU health care workforce remains largely invisible and there appears to be no concerted attempt at EU level to develop appropriate competencies for them. Further research is required into this area, including: evaluative studies of policies for service redesign and new roles, professional regulation and the impact on outcomes for health service users.
The Implications of the “Bologna Process” for the Development of a European Qualification in Psychology
Authors: Lunt Ingrid
Published: June 2005

Abstract. The Bologna Declaration was signed by signatories from 29 countries on 19 June 1999, just over 40 years after the formation of the European Community by the Treaty of Rome in 1957, and heralded the start of what has come to be known as the “Bologna Process,” which aspires to form the “European Higher Education Area” by 2010. The nature, extent, and implications of this process are still unclear, in particular whether it is part of a “harmonization” or “convergence” project or rather more of a comparability and equivalence initiative. Over the past 20 years there have been a number of initiatives within Europe, both at the level of the European Community and within bodies such as the European Federation of Psychologists Associations (EFPA), which have aimed to improve mobility for students and professionals from psychology and other disciplines through attempts to develop systems of mutual recognition of qualifications. One of these initiatives is the development of a European Diploma in Psychology, which aims to set a standard for psychology education and practice; this will be discussed within the context of the “Bologna process.”
Definition and Assessment of Competences in the Context of the European Diploma in Psychology
Authors: Bartram Dave , Roe Robert A.
Published: June 2005

Abstract. The European Diploma in Psychology defines a common European standard for the competences required to practice as a psychologist. This paper describes how that standard was developed and defined, and why it was considered important to bring together the traditional input-based specification of professional competence, in terms of curriculum and training course content, with a more outcome-oriented approach that focuses on the competences that a professional psychologist needs to demonstrate in practice. The paper addresses three specific questions. What are the competences that a psychologist should possess? Are these competences the same for all areas of practice within professional psychology? How can these competences be assessed?
Stress evolution following the 1811–1812 large earthquakes in the New Madrid Seismic Zone
Authors: Li Qingsong , Liu Mian , Sandvol Eric
Published: June 2005

Following a series of large (Mw = 7.0–7.5) earthquakes in the New Madrid Seismic Zone (NMSZ) in the central US during 1811 and 1812, more than a dozen moderate‐size (M > 5) earthquakes occurred in this region, but mostly outside of the NMSZ fault zone. We have simulated the evolution of Coulomb stress and strain energy in the NMSZ and surrounding regions following the large 1811–1812 events in a three‐dimensional viscoelastic finite element model. The results show that much of the stress and strain energy released by the large 1811–1812 events has migrated to southern Illinois and eastern Arkansas, consistent with the seismicity distribution. This inherited strain energy in these areas is capable of producing damaging (M = 6–7) earthquakes today.
Influence of ciliated protozoa and heterotrophic nanoflagellates on the fate of primary production in the northeast Atlantic Ocean
Authors: Karayanni Hera , Christaki Urania , Van Wambeke France , Denis Michel , Moutin Thierry
Published: June 2005

Heterotrophic nanoflagellates and ciliates and their herbivorous activity were studied within the framework of the Programme Océan Multidisciplinaire Méso Echelle (POMME) in the northeastern Atlantic between 16°–22°W and 38°–45°N during winter, spring, and late summer/autumn 2001. Ciliate ingestion rates of Synechococcus and eukaryotic algae were measured using fluorescently labeled prey. Heterotrophic nanoflagellate ingestion rates of Synechococcus and Prochlorococcus were also estimated. Heterotrophic nanoflagellate and ciliate standing stock within the surface layer (0–100 m) showed seasonal variation, with maximal values in spring (866 mg C m−2 and 637 mg C m−2, respectively). Oligotrichs dominated the ciliate assemblages, except at one site visited during spring, where a tintinnid bloom was observed. Ingestion of photosynthetic cells less than 10 μm in size was positively correlated (r = 0.7, p < 0.05, n = 12) with primary production and accounted for 2–94% of this. Phytoplankton consumption reflected differences in the evolution of the phytoplankton bloom and in the structure of the microbial food web, both associated with the strong mesoscale hydrodynamic variability of the study area. In that context it is worthy to note that when tintinnids reached high abundances locally (1260 cells L−1), their impact as phytoplankton grazers was important and reached 69% of primary production. Generally, heterotrophic nanoflagellates and ciliates were relatively more important in determining the fate of phytogenic carbon during spring. Another interesting feature of primary production consumption was that during the autumn, when Prochlorococcus dominated the phytoplankton community, the protozoan grazing activity was ineffective in regulating the fate of primary producers.
Remote sensing and geologic studies of the Balmer‐Kapteyn region of the Moon
Authors: Hawke B. Ray , Gillis J. J. , Giguere T. A. , Blewett D. T. , Lawrence D. J. , Lucey P. G. , Smith G. A. , Spudis P. D. , Taylor G. Jeffrey
Published: June 2005

The Balmer‐Kapteyn (B‐K) region is located just east of Mare Fecunditatis on the east limb of the Moon. It is centered on the Balmer‐Kapteyn basin, a pre‐Nectarian impact structure that exhibits two rings, approximately 225 km and 450 km in diameter. Clementine multispectral images and Lunar Prospector (LP) gamma‐ray spectrometer (GRS) data were used to investigate the composition, age, and origin of geologic units in the region. A major expanse of cryptomare was mapped within the B‐K basin. Spectral and chemical data obtained for dark‐haloed craters (DHCs) established that these impact craters excavated mare basalt from beneath higher‐albedo, highland‐rich surface units. The buried basalts exposed by DHCs in the region are dominated by low‐titanium mare basalts. The fresh DHC FeO values (15.0–15.7 wt.%) that best represent those of buried mare basalts are well within the range of values exhibited by high‐alumina mare basalts. While most cryptomare deposits occur beneath surfaces that range in age from Imbrian to Nectarian, it is possible that some mare flows were emplaced during pre‐Nectarian time. Most cryptomare deposits in the B‐K region were formed by the contamination of mare surfaces by highland‐rich distal ejecta from surrounding impact craters. These Balmer‐type cryptomare deposits are usually associated with light plains units. Major LP‐GRS FeO enhancements are associated with cryptomaria in the Balmer‐Kapteyn, Lomonosov‐Fleming, Schiller‐Schickard, and Mendel‐Rydberg regions.
Radar interference blanking in radio astronomy using a Kalman tracker
Authors: Dong W. , Jeffs B. D. , Fisher J. R.
Published: June 2005

Radio astronomical observations of highly Doppler shifted spectral lines of neutral hydrogen and the hydroxyl molecule must often be made at frequencies allocated to pulsed air surveillance radar in the 1215–1350 MHz frequency range. The Green Bank telescope (GBT) and many other observatories must deal with these terrestrial signals. Even when strong radar fixed clutter echoes are removed, there are still weaker aircraft echoes present which can corrupt the data. We present an algorithm which improves aircraft echo blanking using a Kalman filter tracker to follow the path of a sequence of echoes observed on successive radar antenna sweeps. Aircraft tracks can be used to predict regions (in bearing and range) for the next expected echoes, even before they are detected. These data can then be blanked in real time without waiting for the pulse peak to arrive. Additionally, we briefly suggest an approach for a new Bayesian algorithm which combines tracker and pulse detector operations to enable more sensitive weak pulse detection. Examples are presented for Kalman tracking and radar transmission blanking using real observations at the GBT.
The structure and kinematics of the southeastern Zagros fold‐thrust belt, Iran: From thin‐skinned to thick‐skinned tectonics
Authors: Molinaro M. , Leturmy P. , Guezou J.‐C. , Frizon de Lamotte D. , Eshraghi S. A.
Published: June 2005

We present the first complete balanced cross section across the southeastern Zagros fold‐thrust belt (ZFTB). The following main structural features emerge from this section: (1) In the south of the ZFTB, the Proterozoic‐to‐Recent sedimentary sequence has been decoupled from its Panafrican basement along the ductile basal evaporites and folded into a series of large detachment anticlines. Ongoing shortening of these structures has resulted in migration of the basal salt layers into the cores of the anticlines and propagation of forelimb thrusts. (2) In the north of the ZFTB, deep‐seated ramps have folded the hanging wall rocks and produced imbrications and duplex structures within the higher levels of the sedimentary sequence. (3) Out‐of‐sequence thrusts, linked to major seismogenic basement faults, have cut through the structures in the cover of the ZFTB. A three‐step incremental restoration of the section shows that two main phases of deformation can be separated in the tectonic evolution of the ZFTB: a Mio‐Pliocene thin‐skinned phase, in the course of which most of the structures in the cover were generated, followed by a Pliocene to Recent thick‐skinned phase, expressed as out‐of‐sequence faulting in the cover, which is currently underlined by the seismicity within the basement. In plan view, the initial structures of the southeastern ZFTB developed with a curved shape essentially controlled by the shape and thickness of the underlying Proterozoic salt basin (i.e., the “Jura style”). In the following basement‐involved phase, out‐of‐sequence thrusts cut at oblique angles through the preexisting structures of the cover. The total shortening absorbed in the cover amounts to at least 45 km, corresponding to a ratio of ∼22%.
Active faulting in the Walker Lane
Authors: Wesnousky Steven G.
Published: June 2005

Deformation across the San Andreas and Walker Lane fault systems accounts for most relative Pacific–North American transform plate motion. The Walker Lane is composed of discontinuous sets of right‐slip faults that are located to the east and strike approximately parallel to the San Andreas fault system. Mapping of active faults in the central Walker Lane shows that right‐lateral shear is locally accommodated by rotation of crustal blocks bounded by steep‐dipping east striking left‐slip faults. The left slip and clockwise rotation of crustal blocks bounded by the east striking faults has produced major basins in the area, including Rattlesnake and Garfield flats; Teels, Columbus and Rhodes salt marshes; and Queen Valley. The Benton Springs and Petrified Springs faults are the major northwest striking structures currently accommodating transform motion in the central Walker Lane. Right‐lateral offsets of late Pleistocene surfaces along the two faults point to slip rates of at least 1 mm/yr. The northern limit of northwest trending strike‐slip faults in the central Walker Lane is abrupt and reflects transfer of strike‐slip to dip‐slip deformation in the western Basin and Range and transformation of right slip into rotation of crustal blocks to the north. The transfer of strike slip in the central Walker Lane to dip slip in the western Basin and Range correlates to a northward broadening of the modern strain field suggested by geodesy and appears to be a long‐lived feature of the deformation field. The complexity of faulting and apparent rotation of crustal blocks within the Walker Lane is consistent with the concept of a partially detached and elastic‐brittle crust that is being transported on a continuously deforming layer below. The regional pattern of faulting within the Walker Lane is more complex than observed along the San Andreas fault system to the west. The difference is attributed to the relatively less cumulative slip that has occurred across the Walker Lane and that oblique components of displacement are of opposite sense along the Walker Lane (extension) and San Andreas (contraction), respectively. Despite the gross differences in fault pattern, the Walker Lane and San Andreas also share similarities in deformation style, including clockwise rotations of crustal blocks leading to development of structural basins and the partitioning of oblique components of slip onto subparallel strike‐slip and dip‐slip faults.
Estimating the average time for inter‐continental transport of air pollutants
Authors: Liu Junfeng , Mauzerall Denise L.
Published: June 2005

We estimate the average time required for inter‐continental transport of atmospheric tracers based on simulations with the global chemical tracer model MOZART‐2 driven with NCEP meteorology. We represent the average transport time by a ratio of the concentration of two tracers with different lifetimes. We find that average transport times increase with tracer lifetimes. With tracers of 1‐ and 2‐week lifetimes the average transport time from East Asia (EA) to the surface of western North America (NA) in April is 2–3 weeks, approximately a half week longer than transport from NA to western Europe (EU) and from EU to EA. We develop an ‘equivalent circulation’ method to estimate a timescale which has little dependence on tracer lifetimes and obtain similar results to those obtained with short‐lived tracers. Our findings show that average inter‐continental transport times, even for tracers with short lifetimes, are on average 1–2 weeks longer than rapid transport observed in plumes.
Nighttime chlorine monoxide observations by the Odin satellite and implications for the ClO/Cl2O2 equilibrium
Authors: Berthet G. , Ricaud P. , Lefèvre F. , Le Flochmoën E. , Urban J. , Barret B. , Lautié N. , Dupuy E. , De La Noë J. , Murtagh D.
Published: June 2005

We use measurements of chlorine monoxide (ClO) by the SMR instrument onboard the Odin satellite to study the nighttime thermal equilibrium between ClO and its dimer Cl2O2. Observations performed in the polar vortex during the 2002–2003 Arctic winter showed enhanced amounts of nighttime ClO over a wide range of stratospheric temperatures (185 < T < 225 K). Odin/SMR measurements are here compared to three‐dimensional model calculations using various published estimations of the Keq equilibrium constant between ClO and Cl2O2. Our results show that the value of Keq currently recommended by JPL (Sander et al., 2003) leads to a large underestimation of the observed nighttime ClO amounts, and that a realistic estimation of Keq must lie between the values determined by Cox and Hayman (1988) and Von Hobe et al. (2005).
Fine scale inhomogeneity of wind‐wave energy input, skewness, and asymmetry
Authors: Agnon Yehuda , Babanin Alex V. , Young Ian R. , Chalikov Dmitry
Published: June 2005

Analysis of measured sea and lake wind wave data reveals large variability of the wind energy input, as well as the waves skewness and asymmetry. The spatial and temporal third moments alternate in sign over a few wave periods and over a few wavelengths, respectively. Simulation through a 2D Wave Boundary Layer model in which the air flow is modeled by 2nd order Reynolds equations (Chalikov, 1998) conforms to these findings and exposes a rich structure. We found clear correlation of the variations of the skewness and the asymmetry with the wind input.
2‐D or not 2‐D, that is the question: A northern California test
Authors: Mayeda Kevin , Malagnini Luca , Phillips W. Scott , Walter William R. , Dreger Douglas
Published: June 2005

Reliable estimates of the seismic source spectrum are necessary for accurate magnitude and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1‐D coda methodology of Mayeda et al. [2003] has provided the lowest variance estimate of the source spectrum when compared against traditional approaches that use direct S‐waves, thus making it ideal for networks that have sparse station distribution. The 1‐D coda methodology has been mostly confined to regions of approximately uniform complexity. For larger, more geophysically complicated regions, 2‐D path corrections may be required. The complicated tectonics of the northern California region coupled with high quality broadband seismic data provides for an ideal “apples‐to‐apples” test of 1‐D and 2‐D path assumptions on direct waves and their coda. Using the same station and event distribution, we compared 1‐D and 2‐D path corrections and observed the following results: (1) 1‐D coda results reduced the amplitude variance relative to direct S‐waves by roughly a factor of 8 (800%); (2) Applying a 2‐D correction to the coda resulted in up to 40% variance reduction from the 1‐D coda results; (3) 2‐D direct S‐wave results, though better than 1‐D direct waves, were significantly worse than the 1‐D coda. We found that coda‐based moment‐rate source spectra derived from the 2‐D approach were essentially identical to those from the 1‐D approach for frequencies less than ∼0.7‐Hz, however for the high frequencies (0.7 ≤ f ≤ 8.0‐Hz), the 2‐D approach resulted in inter‐station scatter that was generally 10–30% smaller. For complex regions where data are plentiful, a 2‐D approach can significantly improve upon the simple 1‐D assumption. In regions where only 1‐D coda correction is available it is still preferable over 2‐D direct wave‐based measures.
Influence of Therapeutic Hypothermia on Matrix Metalloproteinase Activity after Traumatic Brain Injury in Rats
Authors: Truettner Jessie S , Alonso Ofelia F , Dietrich W Dalton
Published: June 2005

Recent evidence suggests that matrix metalloproteinases (MMPs) contribute to acute edema and lesion formation following ischemic and traumatic brain injuries (TBI). Experimental and clinical studies have also reported the beneficial effects of posttraumatic hypothermia on histopathological and behavioral outcome. The purpose of this study was to determine whether therapeutic hypothermia would affect the activity of MMPs after TBI. Male Sprague-Dawley rats were traumatized by moderate parasagittal fluid-percussion (F-P) brain injury. Seven groups ( n = 5/group) of animals were investigated: sham-operated, TBI with normothermia (37°C), and TBI with hypothermia (33°C). Normothermia animals were killed at 4, 24, 72 h and 5 days, and hypothermia animals at 24 or 72 h. Brain temperature was reduced to target temperature 30 mins after trauma and maintained for 4 h. Ipsilateral and contralateral cortical, hippocampal, and thalamic regions were analyzed by gelatin and in situ zymography. In traumatized normothermic animals, TBI significantly ( P<0.005) increased MMP-9 levels in ipsilateral (right) cortical and hippocampal regions, compared with contralateral or sham animals, beginning at 4 h and persisting to 5 days. At 1, 3, and 5 days after TBI, significant increases in MMP-2 levels were observed. In contrast to these findings observed with normothermia, posttraumatic hypothermia significantly reduced MMP-9 levels. Hypothermic treatment, however, did not affect the delayed activation of MMP-2. Clarifying the mechanisms underlying the beneficial effects of posttraumatic hypothermia is an active area of research. Posttraumatic hypothermia may attenuate the deleterious consequences of brain trauma by reducing MMP activation acutely.
Location and Function of VPAC1, VPAC2 and NPR-C Receptors in VIP-Induced Vasodilation of Porcine Basilar Arteries
Authors: Grant Stuart , Lutz Eve M , McPhaden Alan R , Wadsworth Roger M
Published: June 2005

Vasoactive intestinal peptide (VIP) is a vasodilator peptide present in cerebrovascular nerves. Vasoactive intestinal peptide can activate VPAC1, VPAC2 and the NPR-C receptor. This study sought to determine the receptors involved in VIP-induced vasodilation of porcine basilar arteries. Porcine basilar arteries contained the messenger ribonucleic acid of all three receptors. Immunocytochemical analysis of porcine basilar arteries revealed that the VPAC1 receptor is expressed on the endothelium, VPAC2 on the outer layers of the media and the NPR-C receptor throughout the artery, including nerves. Vasodilator responses to all receptor agonists showed that the receptors are functional. The vasodilator response to the VPAC1 receptor agonist was inhibited by l-NAME and abolished by endothelial denudation. Vasodilation induced by Ro-25–1553, the VPAC2 agonist, was unaffected by NOS inhibition or removal of the endothelium. Activation of the NPR-C receptor produced a vasodilation, which was susceptible to NOS inhibition and independent of endothelium. The vasodilator response to electrical stimulation at 20 Hz was attenuated by PG-99–465, the VPAC2 antagonist. This study shows that all known VIP receptors are involved in VIP-mediated vasodilation of porcine basilar arteries. The VPAC1 receptor is located on the endothelium and elicits vasodilation by generating nitric oxide (NO). The VPAC2 receptor is mainly expressed in the outer layers of the smooth muscle and induces vasodilation independently of NO in response to VIP released from intramural nerves. The NPR-C receptor produces NO-dependent vasodilation independently of the endothelium by stimulation of nNOS in intramural nerves.
Regional Temperature Changes in the Brain during Somatosensory Stimulation
Authors: Trübel Hubert KF , Sacolick Laura I , Hyder Fahmeed
Published: June 2005

Time-dependent variations in the brain temperature ( Tt) are likely to be caused by fluctuations of cerebral blood flow (CBF) and cerebral metabolic rate of oxidative consumption (CMRO2), both of which are seemingly coupled to alterations in neuronal activity. We combined magnetic resonance, optical imaging, temperature sensing, and electrophysiologic methods in α-chloralose anesthetized rats to obtain multimodal measurements during forepaw stimulation. Localized changes in neuronal activity were colocalized with regional increases in Tt (by ∼0.2%), CBF (by ∼95%), and CMRO2 (by ∼73%). The time-to-peak for Tt (42 ± 11 secs) was significantly longer than those for CBF and CMRO2 (5 ± 2 and 18 ± 4 secs, respectively) with a 2-min stimulation. Net heat in the region of interest (ROI) was modeled as being dependent on the sum of heats attributed to changes in CMRO2 ( Qm) and CBF ( Qf) as well as conductive heat loss from the ROI to neighboring regions ( Qc) and to the environment ( Qe). Although tissue cooling because of Qf and Qc can occur and are enhanced during activation, the net increase in Tt corresponded to a large rise in Qm, whereas effects of Qe can be ignored. The results show that Tt increases slowly (by ∼0.1°C) during physiologic stimulation in α-chloralose anesthetized rats. Because the potential cooling effect of CBF depends on the temperature of blood entering the brain, Tt is mainly affected by CMRO2 during functional challenges. Implications of these findings for functional studies in awake humans and temperature regulation are discussed.
Adult Neurogenesis and the Ischemic Forebrain
Authors: Lichtenwalner Robin J , Parent Jack M
Published: June 2005

The recent identification of endogenous neural stem cells and persistent neuronal production in the adult brain suggests a previously unrecognized capacity for self-repair after brain injury. Neurogenesis not only continues in discrete regions of the adult mammalian brain, but new evidence also suggests that neural progenitors form new neurons that integrate into existing circuitry after certain forms of brain injury in the adult. Experimental stroke in adult rodents and primates increases neurogenesis in the persistent forebrain subventricular and hippocampal dentate gyrus germinative zones. Of greater relevance for regenerative potential, ischemic insults stimulate endogenous neural progenitors to migrate to areas of damage and form neurons in otherwise dormant forebrain regions, such as the neostriatum and hippocampal pyramidal cell layer, of the mature brain. This review summarizes the current understanding of adult neurogenesis and its regulation in vivo, and describes evidence for strokeinduced neurogenesis and neuronal replacement in the adult. Current strategies used to modify endogenous neurogenesis after ischemic brain injury also will be discussed, as well as future research directions with potential for achieving regeneration after stroke and other brain insults.
Depressed Responses to Applied and Synaptically-Released GABA in CA1 Pyramidal Cells, but not in CA1 Interneurons, after Transient Forebrain Ischemia
Authors: Zhan Ren-Zhi , Nadler J Victor , Schwartz-Bloom Rochelle D
Published: June 2005

Transient cerebral ischemia kills CA1 pyramidal cells of the hippocampus, whereas most CA1 interneurons survive. It has been proposed that calcium-binding proteins, neurotrophins, and/or inhibitory neuropeptides protect interneurons from ischemia. However, different synaptic responses early after reperfusion could also underlie the relative vulnerabilities to ischemia of pyramidal cells and interneurons. In this study, we used gramicidin perforated patch recording in ex vivo slices to investigate γ-aminobutyric acid (GABA) synaptic function in CA1 pyramidal cells and interneurons 4 h after a bilateral carotid occlusion accompanied by hypovolemic hypotension. At this survival time, the amplitudes of both miniature inhibitory postsynaptic currents (mIPSCs) and GABA-evoked currents were reduced in CA1 pyramidal cells, but not in CA1 interneurons. In addition, the mean rise time of mIPSCs was reduced in pyramidal cells. The reversal potential for the GABA current ( EGABA) did not shift toward depolarizing values in either cell type, indicating that the driving force for chloride was unchanged at this survival time. We conclude that early during reperfusion GABAergic neurotransmission is attenuated exclusively in pyramidal neurons. This is likely explained by reduced GABAA receptor sensitivity or clustering and possibly also reduced GABA release, rather than by an elevation of intracellular chloride. Impaired GABA function may contribute to ischemic neuronal death by enhancing the excitability of CA1 pyramidal cells and facilitating N-methyl-d-aspartic acid channel opening. Therefore, normalizing GABAergic function might be a useful pharmacological approach to counter excessive, and potentially excitotoxic, glutamatergic activity during the postischemic period.
Stromal Cell-Derived Factor 1α Mediates Neural Progenitor Cell Motility after Focal Cerebral Ischemia
Authors: Robin Adam M , Zhang Zheng G , Wang Lei , Zhang Rui L , Katakowski Mark , Zhang Li , Wang Ying , Zhang Chunling , Chopp Michael
Published: June 2005

In the adult rodent, stroke induces an increase in endogenous neural progenitor cell (NPC) proliferation in the subventricular zone (SVZ) and neuroblasts migrate towards the ischemic boundary. We investigated the role of stromal cell-derived factor 1α (SDF-1α) in mediating NPC migration after stroke. We found that cultured NPCs harvested from the normal adult SVZ, when they were overlaid onto stroke brain slices, exhibited significantly ( P > 0.01) increased migration (67.2 ± 25.2 μm) compared with the migration on normal brain slices (29.5729.5 μm). Immunohistochemistry showed that CXCR 4, a receptor of SDF-1α, is expressed in the NPCs and migrating neuroblasts in stroke brain. Blocking SDF-1α by a neutralizing antibody against CXCR 4 significantly attenuated stroke-enhanced NPC migration. ELISA analysis revealed that SDF-1α levels significantly increased ( P > 0.01) in the stroke hemisphere (43.6 ± 6.5 pg/mg) when compared with the normal brain (25.2± 1.9 pg/mg). Blind-well chamber assays showed that SDF-1α enhanced NPC migration in a dose-dependent manner with maximum migration at a dose of 500ng/mL. In addition, SDF-1α induced directionally selective migration. These findings show that SDF-1α generated in the stroke hemisphere may guide NPC migration towards the ischemic boundary via binding to its receptor CXCR 4 in the NPC. Thus, our data indicate that SDF-1α/CXCR 4 is important for mediating specific migration of NPCs to the site of ischemic damaged neurons.
Brownian motion and diffusion: From stochastic processes to chaos and beyond
Authors: Cecconi F. , Cencini M. , Falcioni M. , Vulpiani A.
Published: June 2005

One century after Einstein’s work, Brownian motion still remains both a fundamental open issue and a continuous source of inspiration for many areas of natural sciences. We first present a discussion about stochastic and deterministic approaches proposed in the literature to model the Brownian motion and more general diffusive behaviors. Then, we focus on the problems concerning the determination of the microscopic nature of diffusion by means of data analysis. Finally, we discuss the general conditions required for the onset of large scale diffusive motion.
Fundamental aspects of quantum Brownian motion
Authors: Hänggi Peter , Ingold Gert-Ludwig
Published: June 2005

With this work we elaborate on the physics of quantum noise in thermal equilibrium and in stationary nonequilibrium. Starting out from the celebrated quantum fluctuation-dissipation theorem we discuss some important consequences that must hold for open, dissipative quantum systems in thermal equilibrium. The issue of quantum dissipation is exemplified with the fundamental problem of a damped harmonic quantum oscillator. The role of quantum fluctuations is discussed in the context of both, the nonlinear generalized quantum Langevin equation and the path integral approach. We discuss the consequences of the time-reversal symmetry for an open dissipative quantum dynamics and, furthermore, point to a series of subtleties and possible pitfalls. The path integral methodology is applied to the decay of metastable states assisted by quantum Brownian noise.
Noise-assisted transport on symmetric periodic substrates
Authors: Borromeo M. , Marchesoni F.
Published: June 2005

The rectification of a massive Brownian particle moving on a periodic substrate can be achieved in the absence of spatial asymmetry, by having recourse to (at least) two periodic, zero-mean input signals. We determine the relevant drift current under diverse operation conditions, namely, additive and multiplicative couplings, adiabatic and fast oscillating drives, and propagating substrate modulations. Distinct rectification mechanisms result from the interplay of noise and commensuration of the input frequencies, mediated through the nonlinearity of the substrate. These mechanisms are then extended to characterize soliton transport along a directed multistable chain. As the side-wise soliton diffusion is ultimately responsible for the transverse diffusion of such chains, our approach provides a full account of the Brownian motion of both pointlike and linear objects on a periodic substrate.
Non-Markovian stochastic processes: Colored noise
Authors: Łuczka J.
Published: June 2005

We survey classical non-Markovian processes driven by thermal equilibrium or nonequilibrium (nonthermal) colored noise. Examples of colored noise are presented. For processes driven by thermal equilibrium noise, the fluctuation-dissipation relation holds. In consequence, the system has to be described by a generalized (integro-differential) Langevin equation with a restriction on the damping integral kernel: Its form depends on the correlation function of noise. For processes driven by nonequilibrium noise, there is no such a restriction: They are considered to be described by stochastic differential (Ito- or Langevin-type) equations with an independent noise term. For the latter, we review methods of analysis of one-dimensional systems driven by Ornstein-Uhlenbeck noise.
Moving backward noisily
Authors: Eichhorn R. , Reimann P. , Cleuren B. , Van den Broeck C.
Published: June 2005

We discuss the fundamental physical differences and the mathematical interconnections of counterintuitive transport and response properties in Brownian motion far from equilibrium. After reviewing the ubiquity of such effects in physical and other systems, we illustrate the general properties on paradigmatic models for both individually and collectively acting Brownian particles.
Noise induced complexity: From subthreshold oscillations to spiking in coupled excitable systems
Authors: Zaks M. A. , Sailer X. , Schimansky-Geier L. , Neiman A. B.
Published: June 2005

We study the stochastic dynamics of an ensemble of N globally coupled excitable elements. Each element is modeled by a FitzHugh–Nagumo oscillator and is disturbed by independent Gaussian noise. In simulations of the Langevin dynamics we characterize the collective behavior of the ensemble in terms of its mean field and show that with the increase of noise the mean field displays a transition from a steady equilibrium to global oscillations and then, for sufficiently large noise, back to another equilibrium. In the course of this transition diverse regimes of collective dynamics ranging from periodic subthreshold oscillations to large-amplitude oscillations and chaos are observed. In order to understand the details and mechanisms of these noise-induced dynamics we consider the thermodynamic limit N→∞ of the ensemble, and derive the cumulant expansion describing temporal evolution of the mean field fluctuations. In Gaussian approximation this allows us to perform the bifurcation analysis; its results are in good qualitative agreement with dynamical scenarios observed in the stochastic simulations of large ensembles.
The subtle nature of financial random walks
Authors: Bouchaud Jean-Philippe
Published: June 2005

We first review the most important “stylized facts” of financial time series, that turn out to be, to a large extent, universal. We then recall how the multifractal random walk of Bacry, Muzy, and Delour generalizes the standard model of financial price changes and accounts in an elegant way for many of their empirical properties. In a second part, we provide empirical evidence for a very subtle compensation mechanism that underlies the random nature of price changes. This compensation drives the market close to a critical point, that may explain the sensitivity of financial markets to small perturbations, and their propensity to enter bubbles and crashes. We argue that the resulting unpredictability of price changes is very far from the neoclassical view that markets are informationally efficient.