6,945 research outputs found
Location Management in Mobile Ad Hoc Wireless Networks Using Quorums and Clusters
Position-based reactive routing is a scalable solution for routing in mobile ad hoc networks. The route discovery algorithm in position-based routing can be efficiently implemented only if the source knows the current address of the destination. In this paper, a quorum-based location management scheme is proposed. Location servers are selected using the minimum dominating set (MDS) approach, and are further organized into quorums for location update and location query. when a mobile node moves, it updates its location servers in the update quorum; when a node requests the location information of another node, it will send a query message to the location servers in the query quorum. We propose to use the position-based quorum system, which is easy to construct and guarantees that the update quorums always intersect with the query quorums so that at least one location server in the query quorum is aware of the most recent location of the mobile node. Clusters are introduced for large scale ad hoc networks for scalability. Experiment results show that the proposed scheme provides good scalability when network size increases
DNA Storage: A Promising Large Scale Archival Storage?
Deoxyribonucleic Acid (DNA), with its high density and long durability, is a
promising storage medium for long-term archival storage and has attracted much
attention. Several studies have verified the feasibility of using DNA for
archival storage with a small amount of data. However, the achievable storage
capacity of DNA as archival storage has not been comprehensively investigated
yet. Theoretically, the DNA storage density is about 1 exabyte/mm3 (109
GB/mm3). However, according to our investigation, DNA storage tube capacity
based on the current synthesizing and sequencing technologies is only at
hundreds of Gigabytes due to the limitation of multiple bio and technology
constraints. This paper identifies and investigates the critical factors
affecting the single DNA tube capacity for archival storage. Finally, we
suggest several promising directions to overcome the limitations and enhance
DNA storage capacity
2-(Thiophen-2-yl)-1-(thiophen-2-ylmethyl)-1H-benzimidazole
In the title compound, C16H12N2S2, the thiophene groups are rotationally disordered over two sets of sites, by approximately 180°, with occupancy ratios of 0.916 (2):0.084 (2) and 0.903 (2):0.097 (2). The major components of the thiophene and methylene substituted thiophene rings are canted by 24.06 (12) and 85.07 (10)°, respectively, from the benzimidazole ring system plane and the dihedral angle between the major component thiophene ring planes is 84.90 (14)°. In the crystal, there is a weak C—H⋯N hydrogen bond which links molecules into chains
Sub-barrier quasifission in heavy element formation reactions with deformed actinide target nuclei
Background: The formation of superheavy elements (SHEs) by fusion of two massive nuclei is severely
inhibited by the competing quasifission process. Low excitation energies favor SHE survival against fusion-fission
competition. In “cold” fusion with spherical target nuclei near 208Pb, SHE yields are largest at beam energies
significantly below the average capture barrier. In “hot” fusion with statically deformed actinide nuclei, this is not
the case. Here the elongated deformation-aligned configurations in sub-barrier capture reactions inhibits fusion
(formation of a compact compound nucleus), instead favoring rapid reseparation through quasifission.
Purpose: To determine the probabilities of fast and slow quasifission in reactions with prolate statically deformed
actinide nuclei, through measurement and quantitative analysis of the dependence of quasifission characteristics
at beam energies spanning the average capture barrier energy.
Methods: The Australian National University Heavy Ion Accelerator Facility and CUBE fission spectrometer
have been used to measure fission and quasifission mass and angle distributions for reactions with projectiles
from C to S, bombarding Th and U target nuclei.
Results: Mass-asymmetric quasifission occurring on a fast time scale, associated with collisions with the tips of
the prolate actinide nuclei, shows a rapid increase in probability with increasing projectile charge, the transition
being centered around projectile atomic number ZP = 14. For mass-symmetric fission events, deviations of
angular anisotropies from expectations for fusion fission, indicating a component of slower quasifission, suggest
a similar transition, but centered around ZP ∼ 8.
Conclusions: Collisions with the tips of statically deformed prolate actinide nuclei show evidence for two distinct
quasifission processes of different time scales. Their probabilities both increase rapidly with the projectile charge.
The probability of fusion can be severely suppressed by these two quasifission processes, since the sub-barrier
heavy element yield is likely to be determined by the product of the probabilities of surviving each quasifission
process.The authors acknowledge support from ARC Grants
No. FL110100098, No. DP130101569, No. FT120100760, No.
DE140100784, No. DP140101337, No. DP160101254, and
No. DP170102318, and support by the Federal Government
NCRIS program for operations of the ANU Heavy Ion Accelerator
Facility
Systematic study of quasifission characteristics and timescales in heavy element formation reactions
Superheavy elements can only be created in the laboratory by the fusion of two massive nuclei. Mass-angle distributions give the most direct information on the characteristics and time scales of quasifission, the major competitor to fusion in these reactions. The systematics of 42 mass-angle distributions provide information on the global characteristics of quasifission. Deviations from the systematics reveal the major role played by the nuclear structure of the two colliding nuclei in determining the reaction outcome, and in hindering or favouring heavy element production.The authors acknowledge operations support for the ANU Heavy Ion Accelerator
Facility from NCRIS, and support from Dr. N. Lobanov and Dr. T.
Kibedi and the ANU Heavy Ion Accelerator Facility staff in operating the
Linac. Financial support from ARC grants DP130101569, DP140101337,
FL110100098, FT120100760 and DE140100784 is acknowledged
Neoadjuvant anti-PD-1 immunotherapy promotes a survival benefit with intratumoral and systemic immune responses in recurrent glioblastoma.
Glioblastoma is the most common primary malignant brain tumor in adults and is associated with poor survival. The Ivy Foundation Early Phase Clinical Trials Consortium conducted a randomized, multi-institution clinical trial to evaluate immune responses and survival following neoadjuvant and/or adjuvant therapy with pembrolizumab in 35 patients with recurrent, surgically resectable glioblastoma. Patients who were randomized to receive neoadjuvant pembrolizumab, with continued adjuvant therapy following surgery, had significantly extended overall survival compared to patients that were randomized to receive adjuvant, post-surgical programmed cell death protein 1 (PD-1) blockade alone. Neoadjuvant PD-1 blockade was associated with upregulation of T cell- and interferon-γ-related gene expression, but downregulation of cell-cycle-related gene expression within the tumor, which was not seen in patients that received adjuvant therapy alone. Focal induction of programmed death-ligand 1 in the tumor microenvironment, enhanced clonal expansion of T cells, decreased PD-1 expression on peripheral blood T cells and a decreasing monocytic population was observed more frequently in the neoadjuvant group than in patients treated only in the adjuvant setting. These findings suggest that the neoadjuvant administration of PD-1 blockade enhances both the local and systemic antitumor immune response and may represent a more efficacious approach to the treatment of this uniformly lethal brain tumor
An intervention to promote physical activity and self-management in people with stable chronic heart failure The Home-Heart-Walk study: study protocol for a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Chronic heart failure (CHF) is a chronic debilitating condition with economic consequences, mostly because of frequent hospitalisations. Physical activity and adequate self-management capacity are important risk reduction strategies in the management of CHF. The Home-Heart-Walk is a self-monitoring intervention. This model of intervention has adapted the 6-minute walk test as a home-based activity that is self-administered and can be used for monitoring physical functional capacity in people with CHF. The aim of the Home-Heart-Walk program is to promote adherence to physical activity recommendations and improving self-management in people with CHF.</p> <p>Methods/Design</p> <p>A randomised controlled trial is being conducted in English speaking people with CHF in four hospitals in Sydney, Australia. Individuals diagnosed with CHF, in New York Heart Association Functional Class II or III, with a previous admission to hospital for CHF are eligible to participate. Based on a previous CHF study and a loss to follow-up of 10%, 166 participants are required to be able to detect a 12-point difference in the study primary endpoint (SF-36 physical function domain).</p> <p>All enrolled participant receive an information session with a cardiovascular nurse. This information session covers key self-management components of CHF: daily weight; diet (salt reduction); medication adherence; and physical activity. Participants are randomised to either intervention or control group through the study randomisation centre after baseline questionnaires and assessment are completed. For people in the intervention group, the research nurse also explains the weekly Home-Heart-Walk protocol. All participants receive monthly phone calls from a research coordinator for six months, and outcome measures are conducted at one, three and six months. The primary outcome of the trial is the physical functioning domain of quality of life, measured by the physical functioning subscale of the Medical Outcome Study Short Form -36. Secondary outcomes include physical functional capacity measured by the standard six minute walk test, self-management capacity, health related quality of life measured by Medical Outcome Study Short Form -36 and Minnesota Living With Heart Failure Questionnaire, self-efficacy and self-care behaviour.</p> <p>Discussion</p> <p>A self-monitoring intervention that can improve individual's exercise self-efficacy, self-management capacity could have potential significance in improving the management of people with chronic heart failure in community settings.</p> <p>Trial Registration</p> <p>Australian New Zealand Clinical Trial Registry 12609000437268</p
Novel prokaryotic expression of thioredoxin-fused insulinoma associated protein tyrosine phosphatase 2 (IA-2), its characterization and immunodiagnostic application
Background
The insulinoma associated protein tyrosine phosphatase 2 (IA-2) is one of the immunodominant autoantigens involved in the autoimmune attack to the beta-cell in Type 1 Diabetes Mellitus. In this work we have developed a complete and original process for the production and recovery of the properly folded intracellular domain of IA-2 fused to thioredoxin (TrxIA-2ic) in Escherichia coli GI698 and GI724 strains. We have also carried out the biochemical and immunochemical characterization of TrxIA-2icand design variants of non-radiometric immunoassays for the efficient detection of IA-2 autoantibodies (IA-2A).
Results
The main findings can be summarized in the following statements: i) TrxIA-2ic expression after 3 h of induction on GI724 strain yielded ≈ 10 mg of highly pure TrxIA-2ic/L of culture medium by a single step purification by affinity chromatography, ii) the molecular weight of TrxIA-2ic (55,358 Da) could be estimated by SDS-PAGE, size exclusion chromatography and mass spectrometry, iii) TrxIA-2ic was properly identified by western blot and mass spectrometric analysis of proteolytic digestions (63.25 % total coverage), iv) excellent immunochemical behavior of properly folded full TrxIA-2ic was legitimized by inhibition or displacement of [35S]IA-2 binding from IA-2A present in Argentinian Type 1 Diabetic patients, v) great stability over time was found under proper storage conditions and vi) low cost and environmentally harmless ELISA methods for IA-2A assessment were developed, with colorimetric or chemiluminescent detection.
Conclusions
E. coli GI724 strain emerged as a handy source of recombinant IA-2ic, achieving high levels of expression as a thioredoxin fusion protein, adequately validated and applicable to the development of innovative and cost-effective immunoassays for IA-2A detection in most laboratories.Fil: Guerra, Luciano Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Faccinetti, Natalia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Trabucchi, Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Rovitto, Bruno David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Sabljic, Adriana Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Poskus, Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Iacono, Ruben Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Valdez, Silvina Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentin
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