bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum anti‐p53 antibodies do not occur in patients with heart failure due to idiopathic dilated and ischemic cardiomyopathies
Authors: Izgi Cemil , Cevik Cihan , Ozdemir Nihal , Kaymaz Cihangir , Ozkan Mehmet
Published: May 2005

Background:

P53 is a key protein which controls cell cycle arrest and apoptosis in response to DNA damage. Auto‐antibodies against p53 have been detected in some cancer patients and also in patients with autoimmune diseases. In these patients, the main cause of anti‐p53 antibody occurrence was considered to be increased intracellular p53 protein in cancer cells and autoreactive lymphocytes, respectively. Intracellular p53 also increases with cardiomyocyte apoptosis during heart failure and autoreactive lymphocytes play a role in the course of idiopathic dilated cardiomyopathy (IDC) and ischemic cardiomyopathy (ICM). Based on these observations, we hypothesized that anti‐p53 antibody response may also occur in patients with heart failure due to ICM and IDC.

Aim:

The aim of this study was to evaluate anti‐p53 antibodies in the serum of patients with heart failure due to IDC and ICM.

Methods:

70 eligible patients with heart failure and severe left ventricular systolic dysfunction (mean fractional shortening 12.03±3.93%) were included in the study. The aetiology of heart failure was IDC in 26 patients and ICM in 44 patients, according to the angiographic and echocardiographic findings.

Results:

Anti‐p53 antibodies were not detected in any of the patients.

Conclusion:

Anti‐p53 antibodies do not occur in patients with heart failure due to IDC and ICM, possible explanations are discussed in the text.
Time dependant differences in pain sensitivity during unilateral ischemic pain provocation in healthy volunteers
Authors: Tuveson Birgitta , Leffler Ann‐Sofie , Hansson Per
Published: May 2005

Plurisegmental endogenous pain inhibitory mechanisms related to diffuse noxious inhibitory controls (DNIC) were demonstrated in animal experiments to act on multireceptive neurons of the entire cord outside the conditioned segment without any side differences. Human experiments have demonstrated altered pain sensitivity to pressure, heat and electrical stimulation during heterotopic noxious conditioning stimulation (HNCS). The purpose of the study was to examine if side and/or time differences in pain thresholds and suprathreshold pain sensitivity for pressure and heat, respectively, could be detected during HNCS. Perception thresholds to pressure and heat pain as well as the sensitivity to suprathreshold pressure (SPP) and heat pain (SHP) were assessed in 18 healthy volunteers bilaterally at the thighs before, during and following ischemia‐induced pain of the left forearm (HNCS). The assessments started with either the right (10 subjects) or the left thigh (8 subjects). During HNCS the pressure pain threshold increased significantly (p< 0.001) on both sides alike. No significant difference in the magnitude of the altered pressure pain threshold was seen between sides for the first or the lastly assessed side. On the lastly assessed side only SPP and SHP increased significantly on both sides alike (p< 0.02 andp< 0.03, respectively), without magnitude differences between sides. During unilateral HNCS of the left arm, a time factor was demonstrated only for alterations in suprathreshold pain sensitivity, without any differences in magnitude between sides. Therefore, the results have implications for future design of HNCS‐related experimental and clinical studies.
The role of mixotrophy in plankton bloom dynamics, and the consequences for productivity
Authors: Hammer Astrid C. , Pitchford Jonathan W.
Published: May 2005

Mixotrophy (=heterotrophy and photosynthesis by a single individual) is a common phenomenon in aquatic ecosystems, in particular under light- or nutrient-limitation. However, it is not usually considered in mathematical models of biological populations. This paper shows how different types of mixotrophy might be usefully incorporated into a general predator–prey model, and explores the consequences for plankton bloom dynamics and productivity. It is demonstrated, analytically and numerically, that even small levels of type III mixotrophy (a small fraction of the zooplankton also being involved in primary production) have significant effects on a system's equilibrium structure, stability, and short-term dynamics. Type III mixotrophy has a stabilizing effect on the system by reducing its excitability, i.e. its propensity to exhibit blooms. Compared with the non-mixotrophic benchmark, for a phytoplankton bloom to be triggered in a system with type III mixotrophy, a much larger perturbation is necessary. Type II mixotrophy (a small fraction of algae engage in phagotrophy) and type I mixotrophy (equal phagotrophy and phototrophy) are briefly discussed. The potential consequences for productivity are also studied. Our results indicate that the phytoplankton–zooplankton system becomes more productive in the presence of type III mixotrophy.
Using survey data independently from commercial data in stock assessment: an example using haddock in ICES Division VIa
Authors: Beare D.J. , Needle C.L. , Burns F. , Reid D.G.
Published: May 2005

Currently standard fish stock biomass estimates are based most directly on commercial catch-at-age data. The main contribution made by research-vessel trawl survey data to the stock assessment process is to “tune” trends in the commercial data and provide estimates of incoming year-class strength. In this process much of the information contained with the survey data (e.g. spatial detail) is lost because the data are first aggregated into numbers-at-age indices for given areas. Another problem is that increasingly restrictive total allowable catches (TACs) imposed on the fishing industry have led to what is suspected to be widespread misreporting, i.e. the scientists do not know how many fish have been landed. This leads to negative biases in the catch data, low stock abundance estimates by scientists, even lower TACs, followed by even more misreporting. One potential way to escape this downward spiral is to explore scientific trawl survey data in more detail since trawl surveys are more straightforward to regulate. Traditionally, there has been resistance to this idea since, in comparison to commercial catch-at-age data, trawl survey data are very sparse in space and time. In this study, the potential for using trawl survey data independently in stock assessments is explored for the case of ICES Area VIa haddock, using two different tools. Findings suggest that it is possible to get qualitatively useful information from trawl survey data alone as well as quantitative, spatially resolved, estimates of fish abundance by making simple swept-area assumptions. In addition, interesting differences between survey and commercial data are highlighted by the study. The mean age of fish reported by the commercial fleet, for example, is higher than that reflected by the survey data, while fishing mortality estimates tend to be higher when estimated from survey data alone.
Risk factors for wound infection following cesarean deliveries
Authors: Schneid‐Kofman N. , Sheiner E. , Levy A. , Holcberg G.
Published: May 2005

Objective: To identify risk factors for early wound infection (diagnosed prior to discharge) following cesarean delivery. Methods: A population‐based study comparing women who have and have not developed a wound infection prior to discharge from Soroka University Medical Center, Ben Gurion University of the Negev, between 1988 and 2002. Results: Of the 19,416 cesarean deliveries performed during the study period, 726 (3.7%) were followed by wound infection. Using a multivariable logistic regression model, the following risk factors were identified: obesity (odds ratio [OR] = 2.2; 95% confidence interval [CI], 1.6–3.1); hypertensive disorders (OR = 1.7; 95% CI, 1.4–2.1); premature rupture of membranes (OR = 1.5; 95% CI, 1.2–1.9); diabetes mellitus (OR = 1.4; 95% CI, 1.1–1.7); emergency cesarean delivery (OR = 1.3; 95% CI, 1.1–1.5); and twin delivery (OR = 1.6; 95% CI, 1.3–2.0). Combined obesity and diabetes (gestational and pregestational) increased the risk for wound infection 9.3‐fold (95% CI, 4.5–19.2; P < .001). Conclusion: Independent risk factors for an early wound infection are obesity, diabetes, hypertension, premature rupture of membranes, emergency cesarean delivery, and twin delivery. Information regarding higher rates of wound infection should be provided to obese women undergoing cesarean delivery, especially when diabetes coexists.
Isolation of feline herpesvirus-1 and feline calicivirus from healthy cats in Swedish breeding catteries
Authors: Holst Bodil Ström , Berndtsson Louise T. , Englund Lena
Published: May 2005

Feline calicivirus (FCV) could be isolated from four cats (2.6%) and feline herpesvirus-1 (FHV) from none of 152 clinically healthy cats from 22 Swedish breeding catteries. These cats had all previously shown signs of respiratory tract disease or conjunctivitis, although several years ago. The results suggest that carriers of FCV and FHV were uncommon in Swedish breeding catteries studied. Prevalence rates in other European countries and North America are usually higher, especially of FCV. The lower prevalence rates in our study might be explained by test group selection, differences in factors such as management, environment, or genetic constitution of the cats, or by sample handling. It was concluded that the presence of an FCV shedder in the cattery does not mean that all cats in the group are infected, but special measures are recommended to avoid infection of susceptible cats.
Intracranial Toxoplasma gondii granuloma in a cat
Authors: Pfohl Jessica C. , Dewey Curtis W.
Published: May 2005

An 8-year-old cat with recent-onset generalized seizures was diagnosed with a right forebrain mass using magnetic resonance imaging. The mass was excised and upon histologic and immunohistochemical examination shown to be a Toxoplasma gondii granuloma. Serology supported active T gondii infection. The cat was treated with phenobarbital to control seizures. After definitive diagnosis of toxoplasma granuloma, clindamycin was administered for approximately 1 month. Seizures recurred 8 months after initial presentation, and the cat was euthanased at the owner's request. This is a previously unreported manifestation of feline central nervous system toxoplasmosis. When a mass lesion is present in the brain of a cat and serologic test results support active infection with T gondii, toxoplasma granuloma must be a differential diagnosis. If the patient is suffering from clinical disease, surgical resection of the mass (if possible) can be complimented with medical treatment until definitive diagnosis is obtained. Immunocompromising factors should be identified and addressed if possible.
Palliative intracavitary carboplatin therapy in a cat with suspected pleural mesothelioma
Authors: Sparkes Andy , Murphy Suzanne , McConnell Fraser , Smith Ken , Blunden Anthony S. , Papasouliotis Kostas , Vanthournout Dominique
Published: May 2005

A 12-year-old neutered male oriental shorthair cat was referred to the Animal Health Trust for investigation of pleural effusion. Ultrasonography revealed marked irregular thickening of the pleural surface of the cranial and caudal mediastinum. Cytological examination of the pleural fluid and fine needle aspirates of the thickened pleura suggested a diagnosis of mesothelioma. Following complete drainage of the thoracic cavity under ultrasound guidance, 180 mg/m2 carboplatin diluted in 60 ml sterile water was infused into the pleural space (30 ml in each hemithorax). This resulted in complete resolution of clinical signs for 34 days (having required thoracocentesis on four occasions in the preceding 4 weeks). The procedure was repeated using 200 mg/m2 carboplatin, and there was a further 20-day period where the cat was free of clinical signs. Further treatment was declined and the cat was euthanased 120 days after initial presentation. This is the first report of successful palliative chemotherapy for suspected feline mesothelioma and suggests that intracavitary carboplatin could be considered in tumours affecting the pleural cavity.
Social exchange in supply chain relationships: The resulting benefits of procedural and distributive justice
Authors: Griffith David A. , Harvey Michael G. , Lusch Robert F.
Published: May 2005

Social exchange theory is used to model the outcomes of procedural and distributive justice in supply chain relationships. In this study, we examine how the enacted procedural and distributive justice policies of a firm influence its partner's attitudes and behaviors within a sample of 290 supply chain relationships. Findings indicate that the perceived procedural and distributive justice of a supplier's policies enhance the long‐term orientation and relational behaviors of its distributor, which, in turn, are associated with decreased conflict and increased satisfaction, that influence the distributor's performance. The authors discuss the importance of the results for academics and practitioners.
Regional atmospheric circulation change in the North Pacific during the Holocene inferred from lacustrine carbonate oxygen isotopes, Yukon Territory, Canada
Authors: Anderson Lesleigh , Abbott Mark B. , Finney Bruce P. , Burns Stephen J.
Published: May 2005

Analyses of sediment cores from Jellybean Lake, a small, evaporation-insensitive groundwater-fed lake, provide a record of changes in North Pacific atmospheric circulation for the last ∽7500 yr at 5- to 30-yr resolution. Isotope hydrology data from the southern Yukon indicate that the oxygen isotope composition of water from Jellybean Lake reflects the composition of mean-annual precipitation, δ18Op. Recent changes in the δ18O of Jellybean sedimentary calcite (δ18Oca) correspond to changes in the North Pacific Index (NPI), a measure of the intensity and position of the Aleutian Low (AL) pressure system. This suggests that δ18Op variability was related to the degree of fractionation during moisture transport from the Gulf of Alaska across the St. Elias Mountains and that Holocene shifts were controlled by the intensity and position of the AL. Following this model, between ∽7500 and 4500 cal yr B.P., long-term trends suggest a predominantly weaker and/or westward AL. Between ∽4500 and 3000 cal yr B.P. the AL shifted eastward or intensified before shifting westward or weakening between ∽3000 and 2000 cal yr B.P. Rapid shifts eastward and/or intensification occurred ∽1200 and 300 cal yr B.P. Holocene changes in North Pacific atmospheric circulation inferred from Jellybean Lake oxygen isotopes correspond with late Holocene glacial advances in the St. Elias Mountains, changes in North Pacific salmon abundance, and shifts in atmospheric circulation over the Beaufort Sea.
The magic of the magic lantern (1660–1700): on analogical demonstration and the visualization of the invisible
Authors: VERMEIR KOEN
Published: May 2005

The history of the magic lantern provides a privileged case study with which to explore the histories of projection, demonstration, illusion and the occult, and their different intersections. I focus on the role of the magic lantern in the work of the Jesuit Athanasius Kircher and the French Cartesian Abbé de Vallemont. After explaining the various meanings of the seventeenth-century concept of illusio, I propose a new solution for the long-standing problem that Kircher added the ‘wrong’ illustrations to his description of the lantern. The complex interaction between text, image and performance was crucial in Kircher's work and these ‘wrong’ figures provide us with a key to interpreting his Ars Magna. I argue that Vallemont used the magic lantern in a similar rhetorical way in a crucial phase of his argument. The magic lantern should not be understood merely as an illustrative image or an item of demonstration apparatus; rather the instrument is employed as part of a performance which is not meant simply to be entertaining. Both authors used a special form of scientific demonstration, which I will term ‘analogical demonstration’, to bolster their world view. This account opens new ways to think about the relation between instruments and the occult.

Sol fons lucis universi, vas admirabile, opus Excelsi, divinitatis thalamus, risus coeli, decor, & pulchritudo mundiA. Kircher

For one of those Gnostics, the visible universe was an illusion or, more precisely, a sophism. Mirrors and fatherhood are abominable because they multiply it and extend it.J. L. Borges
‘A finite universe?’ Riemannian geometry and the Modernist theology of Ernest William Barnes
Authors: VALENTE K. G.
Published: May 2005

As one of the most tireless advocates of Modernism in the Church of England, Ernest William Barnes (1874–1953) was the subject of both veneration and scorn. The position Barnes adopted on evolution during the inter-war years, the period during which he was installed as the Bishop of Birmingham, has been the focus of recent scholarship. In particular, his spiritual agenda departed from those of most Modernists in that it encouraged the faithful to accept the precepts of evolution and Mendelism while it repudiated Lamarckian progressivism. Indeed, his unadulterated appreciation of neo-evolutionary theories makes it easier to understand his willingness to promote eugenic principles.

Another unusual aspect of Barnes's Modernist theology, however, remains to be examined in any detail – namely its mathematical underpinnings. Before rising to his bishopric, Barnes was elected a Fellow of the Royal Society on the strength of his mathematical research. Further, his reputation as one knowledgeable in both modern mathematical and biological investigations provided an authoritative legitimacy that was meant to enhance his efforts at reconciliation, including his Gifford Lectures of 1927 to 1929. This paper examines Barnes's promotion of Riemannian geometry, especially as it relates to the consolation he found in the concept of a finite universe. Ultimately it asserts that mathematics made essential contributions to a cosmological perspective integral to his Modernism.
Museums and Cultural Property: A Retreat from the Internationalist
Approach
Authors: Hallman Robert
Published: May 2005

Responding to J. H. Merryman's discussion of cultural property
internationalism in the preceding IJCP issue, this article
examines the currency of the internationalist perspective within the
museum community. Perhaps surprisingly, there is little evidence of
adherence to an internationalist perspective, at least among the official
policies and publications of museums and museum organizations. The article
proposes that the current dissociation with cultural internationalism in
the acquisitions arena signals an important shift, and bears significant
long-term consequences for many museums.
The paschal alleluia in medieval France
Authors: HUGHES DAVID G.
Published: May 2005

The alleluia was the last proper chant of the Mass to be standardized. Through the twelfth century and beyond, different churches assigned different alleluias to the same Masses, and the composition of new alleluia chants flourished throughout the latter Middle Ages. The Masses from Easter to the octave of Pentecost witness this. A collation of ca. 200 manuscripts demonstrates that identical series of chants are to be found only in sources emanating from the same church (or churches in the same city). Most of the alleluia chants from the eleventh century onward have New Testament or non-scriptural texts, as opposed to the psalmic texts of the earlier post-Pentecostal alleluias. The musical style is varied, ranging from the richly melismatic manner traditionally associated with the alleluia to much more modest melodies with few or no large melismas. A number of the latter can be associated with the reforms of Guillaume de Volpiano at Dijon and in Normandy in the years after 1000.
Transition from antiparallel to component magnetic reconnection
Authors: Swisdak M. , Drake J. F. , Shay M. A. , McIlhargey J. G.
Published: May 2005

We study the transition between antiparallel and component collisionless magnetic reconnection with two‐dimensional particle‐in‐cell simulations. The primary finding is that a guide field ≈0.1 times as strong as the asymptotic reconnecting field (roughly the field strength at which the electron Larmor radius is comparable to the width of the electron current layer) is sufficient to magnetize the electrons in the vicinity of the X line, thus causing significant changes to the structure of the electron dissipation region. This implies that great care should be exercised before concluding that magnetospheric reconnection is antiparallel. We also find that even for such weak guide fields, strong inward flowing electron beams form in the vicinity of the magnetic separatrices and Buneman unstable distribution functions arise at the X line itself. As in the calculations of Hesse et al. (2002) and Yin and Winske (2003) the nongyrotropic elements of the electron pressure tensor play the dominant role in decoupling the electrons from the magnetic field at the X line, regardless of the magnitude of the guide field and the associated strong variations in the pressure tensor's spatial structure. Despite these changes, and consistent with previous work, the reconnection rate does not vary appreciably with the strength of the guide field as it changes between 0 and a value equal to the asymptotic reversed field.
Externally driven magnetic reconnection in the presence of a normal magnetic field
Authors: Pritchett P. L.
Published: May 2005

Studies of tearing instabilities and magnetic reconnection in the terrestrial magnetotail must consider the effect of the finite normal field component Bz. Three‐dimensional (3‐D) particle‐in‐cell simulations with an open geometry are used to investigate the impact of an externally applied convection electric field on the stability of a moderately thick (1.6c/ωpi) current sheet configuration containing a nonzero Bz. The driving field is localized in the direction of the main magnetic field (x) but is uniform in the cross‐tail (y) direction. The initial response of the current sheet to the driving field is dominated by the formation of an embedded electron current layer on the scale of the electron inertial length. This layer forms nearly uniformly in y; cross‐tail modes do not play an important role. Once the normal field is driven southward in a local region of the sheet, global scale reconnection is initiated at a rate comparable to that seen in studies of simple 1‐D current sheets. The formation of the thin electron current layer is accompanied by the development of an electrostatic potential structure which serves to confine the ions in the thin electron layer and to deflect the ions into the outflow region. The reconnection process forms a high‐energy tail on the electron distribution extending up to ∼mec2. These high‐energy electrons are accelerated in the thin electron current sheet and then spread out along the separatrices.
Sensitivity of atmospheric CO2 inversions to seasonal and interannual variations in fossil fuel emissions
Authors: Gurney Kevin Robert , Chen Yu‐Han , Maki Takashi , Kawa S. Randy , Andrews Arlyn , Zhu Zhengxin
Published: May 2005

Estimates of fossil fuel CO2 are a critical component in atmospheric CO2 inversions. Rather than solving for this portion of the atmospheric CO2 budget, inversions typically include estimates of fossil fuel CO2 as a known quantity. However, this assumption may not be appropriate, particularly as inversions continue to solve for fluxes at reduced space and timescales. In this study, two different alterations are made to widely used fossil fuel CO2 emissions estimates, and these altered emissions are run through a series of atmospheric inversion experiments. The first alteration is the inclusion of a seasonal cycle which depends upon both season and latitude. The other alteration is the inclusion of year‐by‐year changes in the spatial distribution of fossil fuel CO2 emissions. All but the interannual inversion experiments are run with three models from the TransCom 3 atmospheric inversion intercomparison. These three models span the key components of atmospheric transport and hence can be expected to capture the range of potential bias caused by assumed fossil fuel CO2 emission estimates when interacting with transport processes. Key findings include the lack of seasonal rectification of the seasonally varying fossil fuel CO2 emissions in the annual mean. Examination of monthly fluxes in the seasonal inversion, however, indicates that significant bias is likely occurring and may be as large as 50% of the residual flux during certain times of the year. In this study, interannual variations were little effected by shifts in the spatial pattern of fossil fuel CO2 emissions. However, as the spatial scale of inversions is reduced, potential bias will likely increase.
Mapping daily snow/ice shortwave broadband albedo from Moderate Resolution Imaging Spectroradiometer (MODIS): The improved direct retrieval algorithm and validation with Greenland in situ measurement
Authors: Liang Shunlin , Stroeve Julienne , Box Jason E.
Published: May 2005

Snow/ice albedo is a critical variable in surface energy balance calculations. The Moderate Resolution Imaging Spectroradiometer (MODIS) data have been used routinely to provide global land surface albedo. The MODIS algorithm includes atmospheric correction, surface reflectance angular modeling, and narrowband to broadband albedo conversion. In an earlier study, a “direct retrieval” methodology was proposed to calculate instantaneous albedo over snow and ice‐covered surfaces directly from top‐of‐atmosphere (TOA) MODIS reflectance data. The method consists of extensive radiative transfer simulations for a variety of atmospheric and surface snow conditions and links the TOA reflectance with surface broadband albedo through regression analysis. Therefore the direct retrieval algorithm implicitly incorporates in a single step all three procedures used in the standard MODIS surface albedo algorithm. This study presents improvements to the retrieval algorithm including validation with in situ measurements distributed over the Greenland ice sheet. Comparison with surface observations demonstrates that the direct retrieval algorithm can produce very accurate daily snow/ice albedo with mean bias of less than 0.02 and residual standard error of 0.04.
The East Siberian Sea as a transition zone between Pacific‐derived waters and Arctic shelf waters
Authors: Semiletov Igor , Dudarev Oleg , Luchin Vladimir , Charkin Alexander , Shin Kyung‐Hoon , Tanaka Nori
Published: May 2005

In the present study we report hydrological (T and S) and hydrochemical data obtained during a Russian Trans‐Arctic cruise in 2000 onboard the Hydrographic Vessel (HV) Nikolay Kolomeytsev, and describe the top layer of the sediment (a typical sample was taken from the upper 0–5 cm layer of bottom sediment) and the distribution of the organic carbon (δ13Corg) and nitrogen (δ15Norg) isotope ratios. Using both historical water data and data from our cruise, we divide the ESS into two specific areas: the Western area, influenced strongly by Lena River input, and the Eastern area, under direct influence of Pacific‐derived water. We also used the stable δ13Corg and δ15Norg isotopes to detect the sediment geochemical boundary (or “geochemical FZ”) between Pacific “marine‐derived sediments” and “terrestrial derived sediments” which can be considered to reflect the long‐term (on a scale of 102 years) position of the most westward extension of Pacific water. These are among the first reliable hydrological and geochemical data reported for the ESS from the Dmitry Laptev Strait to the Long Strait, and they reveal novel insights about interaction between Pacific water and local shelf water.
Experimental constraints on the low gas permeability of vesicular magma during decompression
Authors: Takeuchi Shingo , Nakashima Satoru , Tomiya Akihiko , Shinohara Hiroshi
Published: May 2005

Change in permeability during vesiculation has been measured for vesiculated products from decompression experiments. The permeabilities of the experimental products are less than 10−15.5 m2 at vesicularity less than 45 vol %, and increase by about 2 orders of magnitude with the vesicularity increase from 45 to 80 vol %. The permeability‐vesicularity relationship of the experimental products is quite different from those obtained for natural eruptive materials by previous measurements, which reported a dramatic increase in permeability from 10−15.5 to 10−13 m2 with vesicularity increase from 2 to 40 vol %. The quenched experimental products can be considered as snapshots in vesiculating magma during decompression. Therefore, the permeability variation in vesiculating magma is close to that obtained from the experiments than that obtained from natural eruptive materials, because the latter has experienced complex deformation in the late stages of eruption.
The correlation between mid‐latitude trough and the plasmapause
Authors: Yizengaw E. , Wei H. , Moldwin M. B. , Galvan D. , Mandrake L. , Mannucci A. , Pi X.
Published: May 2005

We use simultaneous global observations of the mid‐latitude trough and the plasmapause to experimentally prove a long‐standing conjecture of magnetosphere‐ionosphere coupling‐ namely the mid‐latitude trough and plasmapause are on the same field line. Global Ionospheric Maps (GIM), generated using ground based GPS receivers, are used to detect the globally extended mid‐latitude trough; while global IMAGE EUV pictures are used to estimate the plasmapause position. Observations during the equinox and solstices and during quiet and disturbed periods are analyzed. In addition, positions of the mid‐latitude trough are calculated using a simple empirical model. The two independent observations (mid‐latitude trough and plasmapause positions) and an empirical model have been compared on a global scale and found to be in excellent agreement.
In Vivo Detection of Developing Vessel Occlusion in Photothrombotic Ischemic Brain Lesions in the Rat by Iron Particle Enhanced MRI
Authors: Kleinschnitz Christoph , Schütz Ansgar , Nölte Ingo , Horn Tanja , Frank Marco , Solymosi Laszlo , Stoll Guido , Bendszus Martin
Published: May 2005

The aim of our study was to visualize developing vessel occlusion in focal cerebral ischemia in vivo. Cortical photothrombosis (PT) was induced in rats, which in addition received superparamagnetic iron oxide (SPIO) particles intravenously. When SPIO particles were applied simultaneously during illumination of the brain for induction of PT, animals showed a markedly hypointense cortical lesion on T2-weighted (T2-w) magnetic-resonance images (MRI). At 3 h after PT, this hypointense area was surrounded by a small hyperintense rim. At 48 h after PT the hyperintense rim had further extended, whereas the hypointense lesion core did not change in size or signal. On histological sections areas of signal loss on T2-w MRI corresponded to local accumulation of iron particles, which were trapped within vessel thrombi. When SPIO particles were applied at 2 h after PT, the lesion appeared hyperintense on T2-w MRI, but was surrounded by a small hypointense rim indicating ongoing vessel occlusion at its outer margins. In contrast, delayed SPIO application at 24 h after completion of PT produced a merely hyperintense cortical lesion on T2-w MRI. Correspondingly, no iron deposits were seen on tissue sections. In conclusion, early SPIO-enhanced MRI provides a reliable in vivo tool to delineate areas of developing vessel occlusion in experimental cerebral ischemia and identifies vessel thrombosis as one mechanism of secondary infarct growth in the PT paradigm. This new imaging technique may aid to evaluate antithrombotic treatment strategies in the future.
Reappearance of Hippocampal CA1 Neurons after Ischemia is Associated with Recovery of Learning and Memory
Authors: Bendel Olof , Bueters Tjerk , von Euler Mia , Ögren Sven Ove , Sandin Johan , von Euler Gabriel
Published: May 2005

The pyramidal neurons of the hippocampal CA1 region are essential for cognitive functions such as spatial learning and memory, and are selectively destroyed after cerebral ischemia. To analyze whether degenerated CA1 neurons are replaced by new neurons and whether such regeneration is associated with amelioration in learning and memory deficits, we have used a rat global ischemia model that provides an almost complete disappearance (to approximately 3% of control) of CA1 neurons associated with a robust impairment in spatial learning and memory at two weeks after ischemia. We found that transient cerebral ischemia can evoke a massive formation of new neurons in the CA1 region, reaching approximately 40% of the original number of neurons at 90 days after ischemia (DAI). Co-localization of the mature neuronal marker neuronal nuclei with 5-bromo-2'-deoxyuridine in CA1 confirmed that neurogenesis indeed had occurred after the ischemic insult. Furthermore, we found increased numbers of cells expressing the immature neuron marker polysialic acid neuronal cell adhesion molecule in the adjacent lateral periventricular region, suggesting that the newly formed neurons derive from this region. The reappearance of CA1 neurons was associated with a recovery of ischemia-induced impairments in spatial learning and memory at 90 DAI, suggesting that the newly formed CA1 neurons restore hippocampal CA1 function. In conclusion, these results show that the brain has an endogenous capacity to form new nerve cells after injury, which correlates with a restoration of cognitive functions of the brain.
Pericapillary Haem-Rich Deposits: Evidence for Microhaemorrhages in Aging Human Cerebral Cortex
Authors: Cullen Karen M , Kócsi Zoltán , Stone Jonathan
Published: May 2005

In this Post mortem study, we examined haem-rich deposits (HRDs) in patients with and without dementia, using a histochemical label (Prussian blue) to show haem, autofluorescence to detect red blood cells (RBCs), and immunohistochemistry for clotting-related factors and collagen IV. The patients studied had no clinical or Post mortem evidence of macrovascular stroke. To allow examination of the spatial relationships between HRDs and the microvasculature, we cut 45-µm sections. Haem-rich deposits were small (< 200 µm diameter). They were rare in younger (< 50 years) patients but were more common in older (> 70 years) patients, particularly in cerebral cortex, and were most abundant in cases with senile plaques. Wherever HRDs appeared they were perivascular and appeared to form around capillaries or small arterioles. Using a software package (Proxan) developed to outline vessels and HRDs, and to analyse the distances between them, a tight spatial correlation between HRDs and capillaries was shown. In addition, HRDs were rich in von Willebrand factor (vWF), fibrinogen, collagen IV and RBCs. These observations suggest that HRDs are the residua of capillary bleeds (microhaemorrhages), and that microhaemorrhages are a common feature of the aging cerebral cortex, particularly where plaque pathology is present.
Enriched Environment Enhances Recovery of Motor Function after Focal Ischemia in Mice, and Downregulates the Transcription Factor NGFI-A
Authors: Nygren Josefine , Wieloch Tadeusz
Published: May 2005

The purpose of this study was to investigate the effect of enriched environment on motor function after experimental stroke in mice, and to determine whether time in enriched environment affects functional recovery. Earlier investigations have shown that rats placed in an enriched environment after focal ischemia, remarkably improve motor function, but similar observations in mice have not been reported. In this study, we show that placing mice in an enriched environment for 3 h daily for 2 weeks, after transient (50 mins) occlusion of the middle cerebral artery, enhanced neurologic outcome. Continuous postischemic housing in the enriched environment likewise improved motor function, but mortality increased. Two weeks exposure to enriched environment followed by housing the mice in standard cages for 2 weeks, resulted in a loss of the improved motor function. In contrast, 4 weeks exposure to enriched environment led to an improved motor function and to a better maintenance of neurologic recovery. The expression levels of the immediate-early gene nerve growth factor-induced gene A at 2 to 3 weeks of recovery decreased in animals housed in enriched environment, implying this transcription factor in the recovery process. We conclude that housing mice in an enriched environment after experimental stroke improves functional outcome. Also, the presented experimental procedure is useful for further studies of the genomics of functional recovery after experimental stroke.
Ab initio calculation of bowl, cage, and ring isomers of C20 and C20−
Authors: An Wei , Gao Yi , Bulusu Satya , Zeng X. C.
Published: May 2005

High-level ab initio calculations have been carried out to reexamine relative stability of bowl, cage, and ring isomers of C20 and C20−. The total electronic energies of the three isomers show different energy orderings, strongly depending on the hybrid functionals selected. It is found that among three popular hybrid density-functional (DF) methods B3LYP, B3PW91, PBE1PBE, and a new hybrid-meta-DF method TPSSKCIS, only the PBE1PBE method (with cc-pVTZ basis set) gives qualitatively correct energy ordering as that predicted from ab initio CCSD(T)/cc-pVDZ [CCSD(T)—coupled-cluster method including singles, doubles, and noniterative perturbative triples; cc-pVDZ—correlation consistent polarized valence double zeta] as well as from MP4(SDQ)/cc-pVTZ [MP4—fourth-order Moller–Plesset; cc-pVTZ—correlation consistent polarized valence triple zeta] calculations. Both CCSD(T) and MP4 calculations indicate that the bowl is most likely the global minimum of neutral C20 isomers, followed by the fullerene cage and ring. For the anionic counterparts, the PBE1PBE calculation also agrees with MP4/cc-pVTZ calculation, both predicting that the bowl is still the lowest-energy structure of C20− at T=0K, followed by the ring and the cage. In contrast, both B3LYP/cc-pVTZ and B3PW91/cc-pVTZ calculations predict that the ring is the lowest-energy structure of C20−. Apparently, this good reliability in predicting the energy ordering renders the hybrid PBE method a leading choice for predicting relative stability among large-sized carbon clusters and other carbon nanostructures (e.g., finite-size carbon nanotubes, nano-onions, or nanohorns). The relative stabilities derived from total energy with Gibbs free-energy corrections demonstrate a changing ordering in which ring becomes more favorable for both C20 and C20− at high temperatures. Finally, photoelectron spectra (PES) for the anionic C20− isomers have been computed. With binding energies up to 7eV, the simulated PES show ample spectral features to distinguish the three competitive C20− isomers.
Intrinsically biased electrocapacitive catalysis
Authors: Sheehan D. P. , Seideman T.
Published: May 2005

We propose the application of the contact potential from metal-metal junctions or the built-in potential of semiconductor p-n junctions to induce or catalyze chemical reactions. Free of external sources, this intrinsic potential across microscale and nanoscale vacuum gaps establishes electric fields in excess of 107V∕m. The electrostatic potential energy of these fields can be converted into useful chemical energy. As an example, we focus on the production of superthermal gas ions to drive reactions. Analysis indicates that this intrinsically biased electrocapacitive catalysis can achieve locally directed ion energies up to a few electron volts and local gas temperature boosts in excess of 104K. Practical considerations for implementation and experimental tests are considered.
Variational calculation of vibrational linear and nonlinear optical properties
Authors: Torrent-Sucarrat Miquel , Luis Josep M. , Kirtman Bernard
Published: May 2005

A variational approach for reliably calculating vibrational linear and nonlinear optical properties of molecules with large electrical and/or mechanical anharmonicity is introduced. This approach utilizes a self-consistent solution of the vibrational Schrödinger equation for the complete field-dependent potential-energy surface and, then, adds higher-level vibrational correlation corrections as desired. An initial application is made to static properties for three molecules of widely varying anharmonicity using the lowest-level vibrational correlation treatment (i.e., vibrational Møller–Plesset perturbation theory). Our results indicate when the conventional Bishop–Kirtman perturbation method can be expected to break down and when high-level vibrational correlation methods are likely to be required. Future improvements and extensions are discussed.
Invariant imbedding theory of mode conversion in inhomogeneous plasmas. I. Exact calculation of the mode conversion coefficient in cold, unmagnetized plasmas
Authors: Kim Kihong , Lee Dong-Hun
Published: May 2005

This is the first of a series of papers devoted to the development of the invariant imbedding theory of mode conversion in inhomogeneous plasmas. A new version of the invariant imbedding theory of wave propagation in inhomogeneous media allows one to solve a wide variety of coupled wave equations exactly and efficiently, even in the cases where the material parameters change discontinuously at the boundaries and inside the inhomogeneous medium. In this paper, the invariant imbedding method is applied to the mode conversion of the simplest kind, that is, the conversion of p-polarized electromagnetic waves into electrostatic modes in cold, unmagnetized plasmas. The mode conversion coefficient and the field distribution are calculated exactly for linear and parabolic plasma density profiles and compared quantitatively with previous results.
Fluid-particle hybrid simulation on the transports of plasma, recycling neutrals, and carbon impurities in the Korea Superconducting Tokamak Advanced Research divertor region
Authors: Kim Deok-Kyu , Hong Sang Hee
Published: May 2005

A two-dimensional simulation modeling that has been performed in a self-consistent way for analysis on the fully coupled transports of plasma, recycling neutrals, and intrinsic carbon impurities in the divertor domain of tokamaks is presented. The numerical model coupling the three major species transports in the tokamak edge is based on a fluid-particle hybrid approach where the plasma is described as a single magnetohydrodynamic fluid while the neutrals and impurities are treated as kinetic particles using the Monte Carlo technique. This simulation code is applied to the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak [G. S. Lee, J. Kim, S. M. Hwang et al., Nucl. Fusion 40, 575 (2000)] to calculate the peak heat flux on the divertor plate and to explore the divertor plasma behavior depending on the upstream conditions in its base line operation mode for various values of input heating power and separatrix plasma density. The numerical modeling for the KSTAR tokamak shows that its full-powered operation is subject to the peak heat loads on the divertor plate exceeding an engineering limit, and reveals that the recycling zone is formed in front of the divertor by increasing plasma density and by reducing power flow into the scrape-off layer. Compared with other researchers’ work, the present hybrid simulation more rigorously reproduces severe electron pressure losses along field lines by the presence of recycling zone accounting for the transitions between the sheath limited and the detached divertor regimes. The substantial profile changes in carbon impurity population and ionic composition also represent the key features of this divertor regime transition.
Characterization of a tungsten/gas multislit collimator for microbeam radiation therapy at the European Synchrotron Radiation Facility
Authors: Bräuer-Krisch E. , Bravin A. , Zhang L. , Siegbahn E. , Stepanek J. , Blattmann H. , Slatkin D. N. , Gebbers J.-O. , Jasmin M. , Laissue J. A.
Published: May 2005

Clinical microbeam radiation therapy (MRT) will require a multislit collimator with adjustable uniform slit widths to enable reliable Monte Carlo-based treatment planning. Such a collimator has been designed, fabricated of >99% tungsten [W] by Tecomet/Viasys (Woburn, Massachusetts, USA) and installed at the 6GeV electron-wiggler-generated hard x-ray ID17 beamline of the European Synchrotron Radiation Facility. Its pair of 125 parallel, 8mm deep, 0.100mm wide radiolucent slits, 0.400mm on center, are perfused with nitrogen gas [N2] to dissipate heat during irradiation. Major improvements in uniformity of microbeam widths and good peak/valley dose ratios combined with a very high dose rate in targeted tissues have been achieved.
Effect of ion ∇B drift direction on density fluctuation poloidal flow and flow shear
Authors: Fenzi C. , McKee G. R. , Fonck R. J. , Burrell K. H. , Carlstrom T. N. , Groebner R. J.
Published: May 2005

The divertor magnetic geometry has a significant effect on the poloidal velocity and resulting velocity shear of turbulent density fluctuations in the outer region of L-mode tokamak plasmas, as determined via two-dimensional measurements of density fluctuations with beam emission spectroscopy on DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)]. Plasmas with similar parameters, except that in one case the ion ∇B drift points towards the divertor X point (lower-single-null, LSN), and in the other case, the ion ∇B drift points away from the divertor X point (upper-single-null, USN), are compared. Inside r∕a=0.9, the turbulence characteristics (density fluctuation amplitude, flow direction, correlation lengths) are similar in both cases, while near r∕a=0.92, a dramatic reversal of the poloidal velocity of turbulent eddies relative to the core flow direction is observed in plasmas with the ion ∇B drift pointing towards the divertor X point. No such velocity reversal is observed in plasmas with the ion ∇B drift pointing away from the divertor X point. This poloidal velocity reversal results in a significantly larger local shear in the poloidal velocity of density fluctuations in plasmas with the ion ∇B drift pointing towards the divertor X point. Additionally, these plasmas locally exhibit significant dispersion with two distinct and counterpropagating turbulence modes. Likewise, the radial correlation length of the density fluctuations is reduced in these plasmas, consistent with biorthogonal decomposition measurements of dominant turbulence structures. The naturally occurring density fluctuation poloidal velocity shear in these LSN plasmas may facilitate the L-H transition that occurs at an input power of roughly one-half to one-third that of corresponding plasmas with the ion ∇B drift pointing away from the X point.
A computational study of hydration, solution structure, and dynamics in dilute carbohydrate solutions
Authors: Lee Sau Lawrence , Debenedetti Pablo G. , Errington Jeffrey R.
Published: May 2005

We report results from a molecular simulation study of the structure and dynamics of water near single carbohydrate molecules (glucose, trehalose, and sucrose) at 0 and 30 °C. The presence of a carbohydrate molecule has a number of significant effects on the microscopic water structure and dynamics. All three carbohydrates disrupt the tetrahedral arrangement of proximal water molecules and restrict their translational and rotational mobility. These destructuring effects and slow dynamics are the result of steric constraints imposed by the carbohydrate molecule and of the ability of a carbohydrate to form stable H bonds with water, respectively. The carbohydrates induce a pronounced decoupling between translational and rotational motions of proximal water molecules.