87 research outputs found
The Soreq Applied Research Accelerator Facility (SARAF) - Overview, Research Programs and Future Plans
The Soreq Applied Research Accelerator Facility (SARAF) is under construction
in the Soreq Nuclear Research Center at Yavne, Israel. When completed at the
beginning of the next decade, SARAF will be a user facility for basic and
applied nuclear physics, based on a 40 MeV, 5 mA CW proton/deuteron
superconducting linear accelerator. Phase I of SARAF (SARAF-I, 4 MeV, 2 mA CW
protons, 5 MeV 1 mA CW deuterons) is already in operation, generating
scientific results in several fields of interest. The main ongoing program at
SARAF-I is the production of 30 keV neutrons and measurement of Maxwellian
Averaged Cross Sections (MACS), important for the astrophysical s-process. The
world leading Maxwellian epithermal neutron yield at SARAF-I (
epithermal neutrons/sec), generated by a novel Liquid-Lithium Target (LiLiT),
enables improved precision of known MACSs, and new measurements of
low-abundance and radioactive isotopes. Research plans for SARAF-II span
several disciplines: Precision studies of beyond-Standard-Model effects by
trapping light exotic radioisotopes, such as He, Li and
Ne, in unprecedented amounts (including meaningful studies already
at SARAF-I); extended nuclear astrophysics research with higher energy
neutrons, including generation and studies of exotic neutron-rich isotopes
relevant to the rapid (r-) process; nuclear structure of exotic isotopes; high
energy neutron cross sections for basic nuclear physics and material science
research, including neutron induced radiation damage; neutron based imaging and
therapy; and novel radiopharmaceuticals development and production. In this
paper we present a technical overview of SARAF-I and II, including a
description of the accelerator and its irradiation targets; a survey of
existing research programs at SARAF-I; and the research potential at the
completed facility (SARAF-II).Comment: 32 pages, 31 figures, 10 tables, submitted as an invited review to
European Physics Journal
Geometric Approach for Optimal Routing on Mesh with Buses
The architecture of 'mesh of buses' is an important model in parallel computing. Its main advantage is that the additional broadcast capability can be used to overcome the main disadvantage of the mesh, namely its relatively large diameter. We show that the addition of buses indeed accelerates routing times. Furthermore, unlike in the `store and forward' model, the routing time becomes proportional to the network load, resulting in decreasing in routing time for a smaller number of packets. We consider 1-1 routing of m packets in a d-dimensional mesh with n d processors and d \Delta n d\Gamma1 buses (one per row and column). The two standard models of accessing the buses are considered and compared: CREW, in which only one processor may transmit at any given time on a given bus, and the CRCW model in which several processors may attempt to transmit at the same time (getting a noise signal as a result). We design a routing algorithm that routes m packets in the CREW model ..
Optimal Search in Trees (Extended Abstract + Appendix)
+ Appendix Yosi Ben-Asher, Eitan Farchi, y Ilan Newman z , Abstract It is well known that the optimal solution for searching in a finite total order set is the binary search. In the binary search we divide the set into two "halves", by querying the middle element, and continue the search on the suitable half. What is the equivalent of binary search, when the set P is partially ordered? A query in this case is to a point x 2 P , with two possible answers: 'yes', indicates that the required element is "below" x, or 'no' if the element is not bellow x. We show that the problem of computing an optimal strategy for search in Posets that are tree-like (or forests) is polynomial in the size of the tree, and requires at most O(n 2 log 2 n) steps. Optimal solutions of such search problems are often needed in program testing and debugging, where a given program is represented as a tree and a bug should be found using a minimal set of queries. 1 Introduction Binary search is a well ..
Optimal Search in Trees
It is well known that the optimal solution for searching in a finite total order set is binary search. In binary search we divide the set into two "halves" by querying the middle element and continue the search on the suitable half. What is the equivalent of binary search when the set P is partially ordered? A query in this case is to a point x 2 P , with two possible answers: `yes', indicates that the required element is "below" x, or `no' if the element is not below x. We show that the problem of computing an optimal strategy for search in Posets that are tree-like (or forests) is polynomial in the size of the tree, and requires at most O(n 4 log 3 n) steps. Optimal solutions of such search problems are often needed in program testing and debugging, where a given program is represented as a tree and a bug should be found using a minimal set of queries. This type of search is also applicable in searching classified large tree-like data bases (e.g. the Internet). Keywords: Optimal ..
The tolerogenic peptide, hCDR1, down-regulates the expression of interferon-α in murine and human systemic lupus erythematosus.
The tolerogenic peptide, hCDR1, ameliorated manifestations of systemic lupus erythematosus (SLE) via the immunomodulation of pro-inflammatory and immunosuppressive cytokines and the induction of regulatory T cells. Because type I interferon (IFN-α) has been implicated to play a role in SLE pathogenesis, we investigated the effects of hCDR1 on IFN-α in a murine model of SLE and in human lupus.(NZBxNZW)F1 mice with established SLE were treated with hCDR1 (10 weekly injections). Splenocytes were obtained for gene expression studies by real-time RT-PCR. hCDR1 down-regulated significantly IFN-α gene expression (73% inhibition compared to vehicle treated mice, p = 0.002) in association with diminished clinical manifestations. Further, hCDR1 reduced, in vitro, IFN-α gene expression in peripheral blood mononuclear cells (PBMC) of 10 lupus patients (74% inhibition compared to medium, p = 0.002) but had no significant effects on the expression levels of IFN-α in PBMC of primary anti-phospholipid syndrome patients or of healthy controls. Lupus patients were treated for 24 weeks with hCDR1 (5) or placebo (4) by weekly subcutaneous injections. Blood samples collected, before and after treatment, were frozen until mRNA isolation. A significant reduction in IFN-α was determined in hCDR1 treated patients (64.4% inhibition compared to pretreatment expression levels, p = 0.015). No inhibition was observed in the placebo treated patients. In agreement, treatment with hCDR1 resulted in a significant decrease of disease activity. IFN-α appears to play a role in the mechanism of action of hCDR1 since recombinant IFN-α diminished the immunomodulating effects of hCDR1 on IL-1β, TGFβ and FoxP3 gene expression.We reported previously that hCDR1 affected various cell types and immune pathways in correlation to disease amelioration. The present studies demonstrate that hCDR1 is also capable of down-regulating significantly (and specifically to lupus) IFN-α gene expression. Thus, hCDR1 has a potential role as a novel, disease specific treatment for lupus
A rare cause of postpartum acute hyponatremia
A previously healthy 24-year-old female underwent an emergent caesarean section without a major bleeding described.
During the first post-operative days (POD) she complained of fatigue, headache and a failure to lactate with no specific
and conclusive findings on head CT. On the following days, fever rose with a suspicion of an obstetric surgery-related
infection, again with no evidence to support the diagnosis. On POD5 a new-onset hyponatremia was documented. The
urine analysis suggested SIADH, and following a treatment failure, further investigation was performed and demonstrated
both central hypothyroidism and adrenal insufficiency. The patient was immediately treated with hydrocortisone followed
by levothyroxine with a rapid resolution of symptoms and hyponatremia. Further laboratory investigation demonstrated
anterior hypopituitarism. The main differential diagnosis was Sheehan’s syndrome vs lymphocytic hypophysitis. Brain MRI
was performed as soon as it was available and findings consistent with Sheehan’s syndrome confirmed the diagnosis.
Lifelong hormonal replacement therapy was initiated. Further complaints on polyuria and polydipsia have led to a water
deprivation testing and the diagnosis of partial central insipidus and appropriate treatment with DDAVP
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