bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppressor of Cytokine Signaling 2 Regulates IL-15–Primed Human NK Cell Function via Control of Phosphorylated Pyk2
Authors: Lee Suk Hyung , Yun Sohyun , Piao Zheng-Hao , Jeong Mira , Kim Dong Oh , Jung Haiyoung , Lee Jiwon , Kim Mi Jeong , Kim Mi Sun , Chung Jin Woong , Kim Tae-Don , Yoon Suk Ran , Greenberg Philip D. , Choi Inpyo 
Published: June 2010

Abstract
NK cells are capable of killing virus-infected or tumor cells and producing IFN-γ. Resting NK cells, however, have only minimal cytolytic activity and secrete a low level of IFN-γ. The cytokine IL-15 can promote the expression of effector functions by resting NK cells. In this study, we demonstrate that suppressor of cytokine signaling 2 (SOCS2) has a novel role in IL-15–primed human NK cell function. SOCS2 expression was upregulated in NK cells following stimulation with IL-15. During IL-15–mediated NK cell priming, SOCS2 interacted with phosphorylated proline-rich tyrosine kinase 2 (Pyk2) at tyrosine 402 (p-Pyk2Tyr402) and induced the proteasome-mediated degradation of p-Pyk2Tyr402 via ubiquitination. Knockdown of SOCS2 resulted in the accumulation of p-Pyk2Tyr402 and blocked NK cell effector functions. In addition, NK cell cytolytic activity and IFN-γ production were inhibited by overexpression of the wild-type of Pyk2 but not by the overexpression of tyrosine 402 mutant of Pyk2. These results suggest that SOCS2 regulates human NK cell effector functions via control of phosphorylated Pyk2 depending on IL-15 existence.
Long Peptide Vaccination Can Lead to Lethality through CD4+ T Cell-Mediated Cytokine Storm
Authors: Kitamura Hiroshi , Sedlik Christine , Jacquet Alexandra , Zaragoza Bruno , Dusseaux Mathilde , Premel Virginie , Sastre-Garau Xavier , Lantz Olivier 
Published: June 2010

Abstract
The optimization of anticancer therapeutic vaccines can lead to better efficacy but also to stronger adverse effects. In a mouse model of antitumor vaccination using a long peptide (LP), which included MHC class I- and II-restricted male (H-Y) epitopes, we observed unexpected mortality. Mice with an increased frequency of anti–H-Y CD4 T cells were primed with LP+CpG and boosted 10 d later. Within hours of boost, they displayed shock-like signs with high mortality. Serum cytokine levels were high. TNF-α secreted by the CD4 T cells was identified as the key effector molecule. Priming with a short peptide (SP), which included the MHC class II-restricted epitope, was a more efficient primer than LP, but did not lead to mortality when used as boost. The high mortality induced by LP compared with SP was probably related to its specific ability to be presented by B cells. Finally, targeting the LP sequence to dendritic cells allowed tumor protection without side effects. Our data: 1) confirm that the immune system can be very dangerous; 2) caution against the use of systemic activation of high-frequency Ag-specific T cells as induced by high doses of LP; and 3) underline the benefit of targeting Ag to dendritic cells.
Atypical squamous cells, cannot exclude high grade squamous intraepithelial (ASC-H) in HIV-positive women
Authors: Michelow* Pam , Hartman Ingrid , Schulze Doreen , Lamla-Hillie Stella , Williams Sophie , Levin Simon , Firnhaber Cynthia 
Published: June 2010

Objective:
South Africa has very high rates of both HIV infection and cervical pathology. The management of ASC-H is colposcopy and directed biopsy, but with so many women diagnosed with HSIL and a dearth of colposcopy centres in South Africa, women with cytologic diagnosis of ASC-H may not be prioritized for colposcopy. The aim of this study was to determine if HIV-positive women with a cytologic diagnosis of ASC-H should undergo immediate colposcopy or whether colposcopy can be delayed, within the context of an underfunded health care setting with so many competing health needs.

Materials and Methods:
A computer database search was performed from the archives of an NGO-administered clinic that offers comprehensive HIV care. All women with a cytologic diagnosis of ASC-H on cervical smears from September 2005 until August 2009 were identified. Histologic follow up was sought in all patients.

Results:
A total of 2111 cervical smears were performed and 41 diagnosed as ASC-H (1.94%). No histologic follow up data was available in 15 cases. Follow up histologic results were as follows: three negative (11.5%), five koilocytosis and/ or CIN1 (19.2%), ten CIN2 (38.5%) and eight CIN3 (30.8%). There were no cases of invasive carcinoma on follow up.

Conclusion:
The current appropriate management of HIV-positive women in low-resource settings with a diagnosis of ASC-H on cervical smear is colposcopy, despite the costs involved. In the future and if cost-effective in developing nations, use of novel markers may help select which HIV-positive women can be managed conservatively and which ones referred for more active treatment. More research in this regard is warranted.
Representing a Product System Representation as a Contractive Semigroup and Applications to Regular Isometric Dilations
Authors: Shalit Orr Moshe 
Published: June 2010

AbstractIn this paper we propose a new technical tool for analyzing representations of Hilbert C*- product systems. Using this tool, we give a new proof that every doubly commuting representation over ℕk has a regular isometric dilation, and we also prove sufficient conditions for the existence of a regular isometric dilation of representations over more general subsemigroups of .
On the Negative Index Theorem for the Linearized Non-Linear Schrödinger Problem
Authors: Vougalter Vitali 
Published: June 2010

AbstractA new and elementary proof is given of the recent result of Cuccagna, Pelinovsky, and Vougalter based on the variational principle for the quadratic form of a self-adjoint operator. It is the negative index theorem for a linearized NLS operator in three dimensions.
Time derivative of the horizontal geomagnetic field as an activity indicator
Authors: Viljanen A. , Nevanlinna H. , Pajunpää K. , Pulkkinen A. 
Published: June 2010

Abstract. Geomagnetically induced currents (GICs) in technological conductor systems are a manifestation of the ground effects of space weather. Large GICs are always associated with large values of the time derivative of the geomagnetic field, and especially with its horizontal component (dH/dt). By using the IMAGE magnetometer data from northern Europe from 1982 to 2001, we show that large dH/dt’s (exceeding 1 nT/s) primarily occur during events governed by westward ionospheric currents. However, the directional distributions of dH/dt are much more scattered than those of the simultaneous baseline subtracted horizontal variation field vector ΔH. A pronounced difference between ΔH and dH/dt takes place at about 02–06 MLT in the auroral region when dH/dt prefers an east-west orientation, whereas ΔH points to the south. The occurrence of large dH/dt has two daily maxima, one around the local magnetic midnight, and another in the morning. There is a single maximum around the midnight only at the southernmost IMAGE stations. An identical feature is observed when large GICs are considered. The yearly number of large dH/dt values in the auroral region follows quite closely the aa index, but a clear variation from year-to-year is observed in the directional distributions. The scattering of dH/dt distributions is smaller during descending phases of the sunspot cycle. Seasonal variations are also seen, especially in winter dH/dt is more concentrated to the north-south direction than at other times. The results manifest the importance of small-scale structures of ionospheric currents when GICs are considered. The distribution patterns of dH/dt cannot be explained by any simple sheet-type model of (westward) ionospheric currents, but rapidly changing north-south currents and field-aligned currents must play an important role.Key words. Geomagnetism and paleomagnetism (geomagnetic induction; rapid time variations) - Ionosphere (ionospheric disturbances)
Field-aligned currents and ionospheric parameters deduced from EISCAT radar measurements in the post-midnight sector
Authors: Sugino M. , Fujii R. , Nozawa S. , Nagatsuma T. , Buchert S. C. , Gjerloev J. W. , Kosch M. J. 
Published: June 2010

Abstract. Attempting to derive the field-aligned current (FAC) density using the EISCAT radar and to understand the role of the ionosphere on closing FACs, we conducted special radar experiments with the EISCAT radar on 9 October 1999. In order to derive the gradient of the ionospheric conductivity (grad S) and the divergence of the electric field (div E) nearly simultaneously, a special experiment employed an EISCAT radar mode which let the transmitting antenna sequentially point to four directions within 10 min; two pairs of the four directions formed two orthogonal diagonals of a square. Our analysis of the EISCAT radar data disclosed that SP div E and E · grad SP produced FACs with the same direction inside a stable broad arc around 05:00 MLT, when the EISCAT radar presumably crossed the boundary between the large-scale upward and downward current regions. In the most successfully observed case, in which the conductances and the electric field were spatially varying with little temporal variations, the contribution of SP div E was nearly twice as large as that of E · grad SP . On the other hand, the contribution of (b × E) · grad SH was small and not effective in closing FACs. The present EISCAT radar mode along with auroral images also enables us to focus on the temporal or spatial variation of high electric fields associated with auroral arcs. In the present experiment, the electric field associated with a stable arc was confined in a spatially restricted region, within ~ 100 km from the arc, with no distinct depletion of electron density. We also detected a region of the high arc-associated electric field, accompanied by the depletion of electron density above 110 km. Using auroral images, this region was identified as a dark spot with a spatial scale of over 150 × 150 km. The dark spot and the electron depletion were likely in existence for a limited time of a few minutes.Key words. Ionosphere (auroral ionosphere; electric fields and currents; particle precipitation)
The occurrence frequency of upward ion beams in the auroral zone as a function of altitude using Polar/TIMAS and DE-1/EICS data
Authors: Janhunen P. , Olsson A. , Peterson W. K. 
Published: June 2010

Abstract. We study the occurrence frequency of upward auroral ion beams as a function of altitude using three years of Polar/TIMAS ion data combined with 11 years of DE-1/ EICS ion data, in order to reach a complete altitude coverage between 5000 and 30 000 km. The most interesting result is that there is a peak in ion beam occurrence frequency and invariant energy flux and invariant particle flux at ¢ 3 RE radial distance. The peak exists at about the same altitude in both the evening and midnight MLT sectors. No solar cycle effects are found. We suggest that the peak could be due to a preferred altitude of auroral potential structures at ¢ 3 RE . To substantiate the suggestion, we also present a simple Monte Carlo simulation of ion beams. Another result is that the ion beam occurrence frequency and invariant (mapped to ionospheric altitude) energy and particle fluxes increase in the radial distance range 4–6 RE , suggesting that wave heating processes may take place in this altitude range.Key words. Magnetospheric physics (auroral phenomena; magnetosphere-ionosphere interactions) – Space plasma physics (charged particle motion and acceleration)
An investigation of latitudinal transitions in the SuperDARN Doppler spectral width parameter at different magnetic local times
Authors: Chisham G. , Freeman M. P. 
Published: June 2010

Abstract. Latitudinal transitions from low to high Doppler spectral width in backscatter measured by the Super Dual Auroral Radar Network (SuperDARN) are now routinely used as proxies for the polar cap boundary (PCB) in the cusp-region ionosphere. In this paper we perform a statistical study of the nature of similar spectral width transitions at other magnetic local times (MLTs). This analysis illustrates that these latitudinal spectral width transitions exist at all magnetic local times, and that the latitude, gradient, and amplitude of the transitions vary systematically with MLT. In particular, the probability of a transition occurring at any latitude, identified independently in each MLT sector, is continuous with MLT from the cusp, through the morning sector, to the nightside. This suggests that the transition represents the PCB, as this is known to be what it represents in the cusp region. However, the picture in the afternoon sector (12:00-18:00 MLT) is more complex with no clearly preferred transition latitudes. Key words. Ionosphere (ionosphere-magnetosphere interactions; instruments and techniques). Magnetospheric physics (magnetopause, cusp, and boundary layers.)
Model results for the ionospheric lower transition height over mid-latitude
Authors: Lei J. , Liu L. , Wan W. , Zhang S.-R. 
Published: June 2010

Abstract. Theoretical calculations of the ionospheric lower transition height (LTH), a level of equal O+ and molecular ion densities, were performed and compared with empirical models by Zhang et al. (1996). This paper represents a substantial extension of the prior work by including the AE-C data of ion composition analysis and by detailed quantitative studies of the LTH simulation, and by creating a new LTH empirical model based on our simulations. Results show that: (1) the calculated LTH, in general, is lowest near 11-13LT and reaches the diurnal maximum after midnight (about 01~02LT). The local time asymmetry becomes more evident in summer, when the time of minimum shifts to 16LT. (2) The simulated LTH presents a dominant, semiannual variation during nighttime, and a pronounced annual variation during daytime. (3) The simulated LTH increases with solar activity at night and decreases by day, while the standard IRI option has an opposite tendency at night in summer and equinox. Therefore, the day-night difference of simulated LTH significantly increases with solar activity. (4) Both daytime and nighttime LTHs, tend to increase with the increasing geomagnetic activity Ap index, with a mean slope about 0.1455km per Ap unit. (5) The diurnal variation of LTH is found to be more than 20 km, which is much larger than the seasonal variation under F107=100 and Ap=10. Thus, the diurnal and solar activity variations of LTH are more pronounced than its seasonal and magnetic activity variations.
Spatial and temporal properties of AKR burst emission derived from Cluster WBD VLBI studies
Authors: Mutel R. L. , Gurnett D. A. , Christopher I. W. 
Published: June 2010

Abstract. We have determined the locations of over 6000 individual auroral kilometric radiation (AKR) bursts between July 2002 and May 2003 using a very long baseline interferometer (VLBI) array. Burst locations were determined by triangulation using differential delays from cross-correlated Cluster WBD waveforms. Typical position uncertainties are 200-400km in the plane normal to the source-spacecraft line, but much larger along this line. The AKR bursts are generally located above the auroral zone with a strong preference for the evening sector (22:00 MLT±2h). However, a few epochs imaged during the austral summer have loci in the daytime sector, especially near 15:00 MLT. There is marginal evidence for a small N-S hemispheric asymmetry in mean MLT and invariant latitude.
Geomagnetic field variations at the equatorial electrojet station in Sri Lanka, Peredinia
Authors: Rastogi R. G. , Kitamura T. , Kitamura K. 
Published: June 2010

Abstract. The paper discusses the variations of the horizontal (H), vertical (Z) and eastward (Y) components of the geomagnetic field at Peredinia (PRD), an electrojet station in Sri Lanka, with the time of the day, season, sudden commencement (SSC) and during geomagnetic storms. The daily variation of H showed a large peak around midday. The daily variation of Z appeared to be almost a time gradient curve of the daily variation of H, showing a maximum around 09:00 LT (75° EMT) when the H field was increasing fastest and not at noon when Δ H was the maximum. Storm time variation of H resembled the variation of the Dst index but that of Z showed a large minimum about 2-3h before the time of minimum Dst or at the time of maximum time gradient of Dst variation. These features are compared with corresponding variations at the equatorial stations Trivandrum (TRD) in India, and remarkable similarity in all observations is noticed at PRD and TRD. It is suggested that the observed abnormal features of Z variations at electrojet stations in India-Sri Lanka are due to (i) direct effect of the ionospheric electrojet current (ii) the induction effect of the image current by the average spatially extended conductivity region and (iii) the induction current in the local subsurface conductor. It is suggested that the conductor responsible for the observed features in Z in India and Sri Lanka has to have extended spatial domain to latitudes well south of India, rather than confined to narrow Palk Strait.
Ionospheric conductivity dependence of dayside region-0, 1, and 2 field-aligned current systems: statistical study with DMSP-F7
Authors: Haraguchi K. , Kawano H. , Yumoto K. , Ohtani S. , Higuchi T. , Ueno G. 
Published: June 2010

Abstract. The present study statistically examines the dependence of the intensities of dayside (MLT=8-12h) large-scale field-aligned currents (FACs) on the ionospheric conductance using the summary data of DMSP-F7 constructed by the procedure of Higuchi and Ohtani (2000). We have found that, in the dayside region, R1 and R0 have a higher correlation between ionospheric conductivity and FAC intensity than R2, suggesting that R0 and R1 are driven by a more voltage-like source than R2. This result is consistent with the idea that R1 and R0 are driven by the interaction between the solar wind and the open magnetospheric magnetic field. We have also found that dayside FAC intensities are latitudinally well balanced when they have a three sheet structure (R0, R1 and R2); on the other hand, for a two sheet structure (R1 and R2), the intensity of R1 is larger than that of R2, so that the net current has the polarity of R1.
Magnetic storm-induced enhancement in neutral composition at low latitudes as inferred by O(&lt;sup&gt;1&lt;/sup&gt;D) dayglow measurements from Chile
Authors: Pallamraju D. , Chakrabarti S. , Valladares C. E. 
Published: June 2010

Abstract. We describe the effect of the 6 November 2001 magnetic storm on the low latitude thermospheric composition. Daytime red line (OI 630.0nm) emissions from Carmen Alto, Chile showed anomalous 2-3 times larger emissions in the morning (05:30-08:30 Local Time; LT) on the disturbed day compared to the quiet days. We interpret these emission enhancements to be caused due to the increase in neutral densities over low latitudes, as a direct effect of the geomagnetic storm. As an aftereffect of the geomagnetic storm, the dayglow emissions on the following day show gravity wave features that gradually increase in periodicities from around 30min in the morning to around 100min by the evening. The integrated dayglow emissions on quiet days show day-to-day variabilities in spatial structures in terms of their movement away from the magnetic equator in response to the Equatorial Ionization Anomaly (EIA) development in the daytime. The EIA signatures in the daytime OI 630.0nm column-integrated dayglow emission brightness show different behavior on days with and without the post-sunset Equatorial Spread F (ESF) occurrence.
High altitude large-scale plasma waves in the equatorial electrojet at twilight
Authors: Chau J. L. , Hysell D. L. 
Published: June 2010

Abstract. Jicamarca radar observations of a new class of large-scale plasma waves in the equatorial electrojet (EEJ) are presented and characterized. The study is based on long-term (204 days), single-baseline interferometry observations made in 2003 using a low-power radar mode, also known as JULIA mode, along with a few hours of observations made in an aperture synthesis imaging mode. The large-scale waves are found to occur at high altitudes in the E-region, mainly between 120 and 140km, around twilight (between 18:30 and 20:00 LT), with durations of a few minutes to an hour. In our long-term observations, these large-scale waves occur very often (between 1 and 5 out 10 nights), drift westward (~70 ms–1), exhibit very narrow spectral widths, and have both positive and negative Doppler shifts. The imaging results show that the large-scale waves occur along tilted bands that sweep westward and downward (~30–60ms–1), with a horizontal separation between bands of about 10–15km. The cause of the waves remains unknown. Key words. Ionosphere (ionospheric irregularities; equatorial ionosphere; instruments and techniques)
Plasma depletion layer: its dependence on solar wind conditions and the Earth dipole tilt
Authors: Wang Y. L. , Raeder J. , Russell C. T. 
Published: June 2010

Abstract. The plasma depletion layer (PDL) is a layer on the sunward side of the magnetopause with lower plasma density and higher magnetic field compared to their corresponding upstream magnetosheath values. It is believed that the PDL is controlled jointly by conditions in the solar wind plasma and the (IMF). In this study, we extend our former model PDL studies by systematically investigating the dependence of the PDL and the slow mode front on solar wind conditions using global MHD simulations. We first point out the difficulties for the depletion factor method and the plasma β method for defining the outer boundary of the plasma depletion layer. We propose to use the N/B ratio to define the PDL outer boundary, which can give the best description of flux tube depletion. We find a strong dependence of the magnetosheath environment on the solar wind magnetosonic Mach number. A difference between the stagnation point and the magnetopause derived from the open-closed magnetic field boundary is found. We also find a strong and complex dependence of the PDL and the slow mode front on the IMF Bz. A density structure right inside the subsolar magnetopause for higher IMF Bz;might be responsible for some of this dependence. Both the IMF tilt and clock angles are found to have little influence on the magnetosheath and the PDL structures. However, the IMF geometry has a much stronger influence on the slow mode fronts in the magnetosheath. Finally, the Earth dipole tilt is found to play a minor role for the magnetosheath geometry and the PDL along the Sun-Earth line. A complex slow mode front geometry is found for cases with different Earth dipole tilts. Comparisons between our results with those from some former studies are conducted, and consistencies and inconsistencies are found. Key words. Magnetospheric physics (magnetosheath, solar wind-magnetosphere interactions) – Space plasma physics (numerical simulation studies)