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1.
Space Sci Rev ; 219(2): 18, 2023.
Article in English | MEDLINE | ID: mdl-36874191

ABSTRACT

A detailed overview of the knowledge gaps in our understanding of the heliospheric interaction with the largely unexplored Very Local Interstellar Medium (VLISM) are provided along with predictions of with the scientific discoveries that await. The new measurements required to make progress in this expanding frontier of space physics are discussed and include in-situ plasma and pick-up ion measurements throughout the heliosheath, direct sampling of the VLISM properties such as elemental and isotopic composition, densities, flows, and temperatures of neutral gas, dust and plasma, and remote energetic neutral atom (ENA) and Lyman-alpha (LYA) imaging from vantage points that can uniquely discern the heliospheric shape and bring new information on the interaction with interstellar hydrogen. The implementation of a pragmatic Interstellar Probe mission with a nominal design life to reach 375 Astronomical Units (au) with likely operation out to 550 au are reported as a result of a 4-year NASA funded mission study.

2.
Rev Sci Instrum ; 85(3): 035113, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24689626

ABSTRACT

A linear time-of-flight mass spectrometer is developed for the detection and chemical analysis of nanometer-sized particles originating near the Sun. Nano-dust particles are thought to be produced by mutual collisions between interplanetary dust particles slowly spiraling toward the Sun and are accelerated outward to high velocities by interaction with the solar wind plasma. The WAVES instruments on the two STEREO spacecraft reported the detection, strong temporal variation, and potentially high flux of these particles. Here we report on the optimization and the results from the detailed characterization of the instrument's performance using submicrometer sized dust particles accelerated to 8-60 km/s. The Nano Dust Analyzer (NDA) concept is derived from previously developed detectors. It has a 200 cm(2) effective target area and a mass resolution of approximately m/Δm = 50. The NDA instrument is designed to reliably detect and analyze nanometer-sized dust particles while being pointed close to the Sun's direction, from where they are expected to arrive. Measurements by such an instrument will determine the size-dependent flux of the nano-dust particles and its variations, it will characterize the composition of the nano-dust and, ultimately, it may determine their source. The flight version of the NDA instrument is estimated to be <5 kg and requires <10 W for operation.

3.
Science ; 343(6174): 988-90, 2014 Feb 28.
Article in English | MEDLINE | ID: mdl-24526313

ABSTRACT

Observations with the Interstellar Boundary Explorer (IBEX) have shown enhanced energetic neutral atom (ENA) emission from a narrow, circular ribbon likely centered on the direction of the local interstellar medium (LISM) magnetic field. Here, we show that recent determinations of the local interstellar velocity, based on interstellar atom measurements with IBEX, are consistent with the interstellar modulation of high-energy (tera-electron volts, TeV) cosmic rays and diffusive propagation from supernova sources revealed in global anisotropy maps of ground-based high-energy cosmic-ray observatories (Milagro, Asγ, and IceCube). Establishing a consistent local interstellar magnetic field direction using IBEX ENAs at hundreds to thousands of eV and galactic cosmic rays at tens of TeV has wide-ranging implications for the structure of our heliosphere and its interactions with the LISM, which is particularly important at the time when the Voyager spacecraft are leaving our heliosphere.

4.
Science ; 341(6150): 1080-2, 2013 Sep 06.
Article in English | MEDLINE | ID: mdl-24009386

ABSTRACT

The journey of the Sun through the dynamically active local interstellar medium creates an evolving heliosphere environment. This motion drives a wind of interstellar material through the heliosphere that has been measured with Earth-orbiting and interplanetary spacecraft for 40 years. Recent results obtained by NASA's Interstellar Boundary Explorer mission during 2009-2010 suggest that neutral interstellar atoms flow into the solar system from a different direction than found previously. These prior measurements represent data collected from Ulysses and other spacecraft during 1992-2002 and a variety of older measurements acquired during 1972-1978. Consideration of all data types and their published results and uncertainties, over the three epochs of observations, indicates that the trend for the interstellar flow ecliptic longitude to increase linearly with time is statistically significant.

5.
Science ; 326(5955): 966-8, 2009 Nov 13.
Article in English | MEDLINE | ID: mdl-19833915

ABSTRACT

Simulations of energetic neutral atom (ENA) maps predict flux magnitudes that are, in some cases, similar to those observed by the Interstellar Boundary Explorer (IBEX) spacecraft, but they miss the ribbon. Our model of the heliosphere indicates that the local interstellar medium (LISM) magnetic field (B(LISM)) is transverse to the line of sight (LOS) along the ribbon, suggesting that the ribbon may carry its imprint. The force-per-unit area on the heliopause from field line draping and the LISM ram pressure is comparable with the ribbon pressure if the LOS approximately 30 to 60 astronomical units and B(LISM) approximately 2.5 microgauss. Although various models have advantages in accounting for some of the observations, no model can explain all the dominant features, which probably requires a substantial change in our understanding of the processes that shape our heliosphere.

6.
Rev Sci Instrum ; 78(12): 124502, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18163739

ABSTRACT

The direct measurement of the energetic neutral atoms originating from the heliospheric termination shock and beyond as well as neutral interstellar gas penetrating into the heliosphere requires a very sensitive neutral particle imaging instrument in the energy range of 10-1000 eV. We present the development of the prototype of the low energy sensor for the Interstellar Boundary Explorer (IBEX) mission: IBEX-Lo is a neutral particle mass spectrometer dedicated to the measurement of energetic neutral atoms in this energy range. The response of the sensor to incident neutral hydrogen, helium, and oxygen atoms is discussed as well as the properties of the sensor's ion optics, the neutral-to-negative conversion surfaces, and other instrumental parameters.


Subject(s)
Linear Energy Transfer , Radiometry/instrumentation , Spacecraft/instrumentation , Equipment Design , Equipment Failure Analysis , Ions , Miniaturization , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity
7.
Langenbecks Arch Surg ; 385(6): 393-7, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11127523

ABSTRACT

BACKGROUND AND AIMS: Adrenocortical carcinoma (ACC) is a rare tumour with an incidence of approximately 0.5-2 cases per million per year. Diagnosis is mostly delayed and prognosis is poor. We report our experiences with 11 patients operated on within the last 10 years. PATIENTS/METHODS: The data of the patients with ACC were reviewed and presenting symptoms, diagnostic procedures, treatment and results of follow-up were evaluated. RESULTS: The group of patients consisted of eight women and three men with a mean age of 40.2 (15-57) years. Median follow-up was 16 (1-71) months. Six patients presented with Cushing's syndrome, two presented with virilism and hirsutism caused by androgen-producing tumours. Three patients had hormonally inactive tumours. At the time of diagnosis, five tumours were classified as stage II, two as stage III and four as stage IV. Four patients had tumours with intravascular extension, prompting recurrence in two cases. Eight adrenalectomies, one resection of local recurrence, one adrenalectomy with splenectomy and one adrenalectomy and resection of a liver metastasis were performed. Five patients received additional chemotherapy. Five of the 11 patients are still alive (three stage II, one stage III and one stage IV at the time of diagnosis), three of whom have no evidence of disease (14, 48 and 71 months after surgery). The other six patients died after a median postoperative period of 10 (1-21) months. CONCLUSIONS: Venography should be performed prior to surgery to detect or exclude thrombotic tumour masses in the suprarenal vein, renal vein or inferior vena cava. Radical surgery is the only curative approach and is recommended for all patients with resectable tumours, including those patients with recurrent disease. There is no consensus concerning adjuvant therapy. The value of multidisciplinary strategies needs to be assessed in multicentre trials.


Subject(s)
Adrenal Cortex Neoplasms/surgery , Adrenocortical Carcinoma/surgery , Adolescent , Adrenal Cortex Neoplasms/drug therapy , Adrenal Cortex Neoplasms/mortality , Adrenal Cortex Neoplasms/pathology , Adrenocortical Carcinoma/drug therapy , Adrenocortical Carcinoma/mortality , Adrenocortical Carcinoma/pathology , Adult , Chemotherapy, Adjuvant , Female , Humans , Male , Middle Aged , Neoplasm Staging , Prognosis , Retrospective Studies
8.
Nature ; 404(6780): 848-50, 2000 Apr 20.
Article in English | MEDLINE | ID: mdl-10786785

ABSTRACT

Magnetic reconnection is a process that converts magnetic energy into bi-directional plasma jets; it is believed to be the dominant process by which solar-wind energy enters the Earth's magnetosphere. This energy is subsequently dissipated by magnetic storms and aurorae. Previous single-spacecraft observations revealed only single jets at the magnetopause--while the existence of a counter-streaming jet was implicitly assumed, no experimental confirmation was available. Here we report in situ two-spacecraft observations of bi-directional jets at the magnetopause, finding evidence for a stable and extended reconnection line; the latter implies substantial entry of the solar wind into the magnetosphere. We conclude that reconnection is determined by large-scale interactions between the solar wind and the magnetosphere, rather than by local conditions at the magnetopause.

9.
J Pediatr ; 119(3): 380-5, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1880650

ABSTRACT

Because the classic hemolytic-uremic syndrome has been etiologically linked to intestinal infections by Escherichia coli O157 and other verotoxin-producing E. coli (VTEC), we examined 22 consecutive children with acute hemolytic-uremic syndrome for the presence of VTEC, using microbiologic methods, and for a specific immune response to O157 lipopolysaccharide in acute-phase and follow-up sera, using the indirect hemagglutination assay and the immunoblot procedure. Of 22 children with enteropathic hemolytic-uremic syndrome, 15 (68%) had evidence of VTEC infection by culture of the pathogen or detection of free verotoxin in the feces, or both. Significantly elevated titers of short-lived agglutinins and IgM class antibodies against the O157 lipopolysaccharide were found in 20 (91%) of 22 patients, but not in two of three patients with non-O157 E. coli isolates or in healthy children or children with diarrhea caused by other enteric pathogens (p less than 0.01). The combined microbiologic and serologic procedures provided evidence for VTEC infection in all 22 patients. The high incidence of anti-O157 lipopolysaccharide antibodies in these patients indicates the predominance and the pathogenic potential of this serogroup. Both serologic techniques proved to be valuable tools to further characterize this form of hemolytic-uremic syndrome. Future studies on the induction of protective immunity seem warranted.


Subject(s)
Antibodies, Bacterial/blood , Bacterial Toxins/analysis , Escherichia coli/immunology , Hemolytic-Uremic Syndrome/immunology , Lipopolysaccharides/immunology , Antibodies, Anti-Idiotypic/immunology , Child , Child, Preschool , Feces/chemistry , Feces/microbiology , Hemagglutination Tests , Hemolytic-Uremic Syndrome/microbiology , Humans , Immunoglobulin M/immunology , Infant , Serotyping , Shiga Toxin 1
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