A Flexible and Fast Event-Driven Simulator for wireless MAC protocols

Many multiple-access (MAC) protocols have been or are being proposed for wireless networks. As most of these multiple-access protocols are designed for specific applications (such as telephony) and analyzed accordingly, the analysis results can not always be adapted to situations where each user has a different behavior. Wireless MAC protocols for data communication are not straightforward to analyse. To quickly make a reliable judgement of the usability of a MAC protocol for specific situations, we designed a simulator that makes it simple to implement the protocol and test it in different configurations and with differently behaving users. Our simulator generates a large amount of quantitative performance information that can be processed with standard graph drawing tools and an integrated trace analyze

Phase I dose-escalation and pharmacokinetic study of dasatinib in patients with advanced solid tumors

PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicity (DLT), and recommended phase II dose of dasatinib in metastatic solid tumors refractory to standard therapies or for which no effective standard therapy exists. <br></br> EXPERIMENTAL DESIGN: In this phase I, open-label, dose-escalation study, patients received 35 to 160 mg of dasatinib twice daily in 28-day cycles either every 12 hours for 5 consecutive days followed by 2 nontreatment days every week (5D2) or as continuous, twice-daily (CDD) dosing. <br></br> RESULTS: Sixty-seven patients were treated (5D2, n = 33; CDD, n = 34). The maximum tolerated doses were 120 mg twice daily 5D2 and 70 mg twice daily CDD. DLTs with 160 mg 5D2 were recurrent grade 2 rash, grade 3 lethargy, and one patient with both grade 3 prolonged bleeding time and grade 3 hypocalcemia; DLTs with 120 mg twice daily CDD were grade 3 nausea, grade 3 fatigue, and one patient with both grade 3 rash and grade 2 proteinuria. The most frequent treatment-related toxicities across all doses were nausea, fatigue, lethargy, anorexia, proteinuria, and diarrhea, with infrequent hematologic toxicities. Pharmacokinetic data indicated rapid absorption, dose proportionality, and lack of drug accumulation. Although no objective tumor responses were seen, durable stable disease was observed in 16% of patients.<br></br> CONCLUSION: Dasatinib was well tolerated in this population, with a safety profile similar to that observed previously in leukemia patients, although with much less hematologic toxicity. Limited, although encouraging, preliminary evidence of clinical activity was observed. Doses of 120 mg twice daily (5D2) or 70 mg twice daily (CDD) are recommended for further studies in patients with solid tumors.<br></br&gt

Quantum railroads and directed localization at the juncture of quantum Hall systems

The integer quantum Hall effect (QHE) and one-dimensional Anderson localization (AL) are limiting special cases of a more general phenomenon, directed localization (DL), predicted to occur in disordered one-dimensional wave guides called "quantum railroads" (QRR). Here we explain the surprising results of recent measurements by Kang et al. [Nature 403, 59 (2000)] of electron transfer between edges of two-dimensional electron systems and identify experimental evidence of QRR's in the general, but until now entirely theoretical, DL regime that unifies the QHE and AL. We propose direct experimental tests of our theory.Comment: 11 pages revtex + 3 jpeg figures, to appear in Phys. Rev.

A spliced latency-associated VZV transcript maps antisense to the viral transactivator gene

Varicella-zoster virus (VZV), an alphaherpesvirus, establishes lifelong latent infection in the neurons of >90% humans worldwide, reactivating in one-third to cause shingles, debilitating pain and stroke. How VZV maintains latency remains unclear. Here, using ultra-deep virus-enriched RNA sequencing of latently infected human trigeminal ganglia (TG), we demonstrate the consistent expression of a spliced VZV mRNA, antisense to VZV open reading frame 61 (ORF61). The spliced VZV latency-associated transcript (VLT) is expressed in human TG neurons and encodes a protein with late kinetics in productively infected cells in vitro and in shingles skin lesions. Whereas multiple alternatively spliced VLT isoforms (VLTly) are expressed during lytic infection, a single unique VLT isoform, which specifically suppresses ORF61 gene expression in co-transfected cells, predominates in latently VZV-infected human TG. The discovery of VLT links VZV with the other better characterized human and animal neurotropic alphaherpesviruses and provides insights into VZV latency

Ectopic expression of Thy-1 in the kidneys of transgenic mice induces functional and proliferative abnormalities.

Hybrid human--mouse Thy-1.1 genes were injected into pronuclei of Thy-1.2 mice to produce transgenic animals. A hybrid gene composed of the 5' part of the mouse Thy-1.1 gene combined with the 3' human untranslated regions was expressed abnormally in the kidney podocytes, which resulted in severe protein-uria and subsequent death in several founder mice. A hybrid Thy-1 gene composed of the human coding region with the 5' and 3' flanking regions of the mouse gene was expressed abnormally in a different part of the kidney (the tubular epithelia), which resulted in a proliferative kidney disorder. In addition, a neoplasm was found in the brain of one of these mice. These results show that the Thy-1 protein can play an important role in the activation, proliferation, and differentiation of many different cell types

Disruption of the murine major vault protein (MVP/LRP) gene does not induce hypersensitivity to cytostatics

Vaults are ribonucleoprotein particles with a distinct structure and a high degree of conservation between species. Although no function has been assigned to the complex yet, there is some evidence for a role of vaults in multidrug resistance. To confirm a direct relation between vaults and multidrug resistance, and to investigate other possible functions of vaults, we have generated a major vault protein (MVP/lung resistance-related protein) knockout mouse model. The MVP(-/-) mice are viable, healthy, and show no obvious abnormalities. We investigated the sensitivity of MVP(-/-) embryonic stem cells and bone marrow cells derived from the MVP-deficient mice to various cytostatic agents with different mechanisms of action. Neither the MVP(-/-) embryonic stem cells nor the MVP(-/-) bone marrow cells showed an increased sensitivity to any of the drugs examined, as compared with wild-type cells. Furthermore, the activities of the ABC-transporters P-glycoprotein, multidrug resistance-associated protein and breast cancer resistance protein were unaltered on MVP deletion in these cells. In addition, MVP wild-type and deficient mice were treated with the anthracycline doxorubicin. Both groups of mice responded similarly to the doxorubicin treatment. Our results suggest that MVP/vaults are not directly involved in the resistance to cytostatic agents

Magnetic Fields, Relativistic Particles, and Shock Waves in Cluster Outskirts

It is only now, with low-frequency radio telescopes, long exposures with high-resolution X-ray satellites and gamma-ray telescopes, that we are beginning to learn about the physics in the periphery of galaxy clusters. In the coming years, Sunyaev-Zeldovich telescopes are going to deliver further great insights into the plasma physics of these special regions in the Universe. The last years have already shown tremendous progress with detections of shocks, estimates of magnetic field strengths and constraints on the particle acceleration efficiency. X-ray observations have revealed shock fronts in cluster outskirts which have allowed inferences about the microphysical structure of shocks fronts in such extreme environments. The best indications for magnetic fields and relativistic particles in cluster outskirts come from observations of so-called radio relics, which are megaparsec-sized regions of radio emission from the edges of galaxy clusters. As these are difficult to detect due to their low surface brightness, only few of these objects are known. But they have provided unprecedented evidence for the acceleration of relativistic particles at shock fronts and the existence of muG strength fields as far out as the virial radius of clusters. In this review we summarise the observational and theoretical state of our knowledge of magnetic fields, relativistic particles and shocks in cluster outskirts.Comment: 34 pages, to be published in Space Science Review

Growth, yield and scion-rootstock interaction effects of the custard apple in south-east Queensland

The growth and yield of African Pride and Pink's Mammoth custard apple cultivars were evaluated for two rootstocks under the subtropical environment of south-east Queensland. The African Pride cultivar was a much more precocious bearer than Pink's Mammoth. In the sixth year after planting, the mean marketable yields for African Pride were 18.7 t/ha on cherimoyer rootstock and 9.2 t/ha on sugar apple. In comparison, the Pink's Mammoth cultivar produced 7.2 t/ha on cherimoyer rootstock and 6.2 t/ha on sugar apple. The experiment demonstrated that satisfactory yields can be obtained with the African Pride cultivar without the need for hand pollination

The formation of vault-tubes: a dynamic interaction between vaults and vault PARP

Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles that are composed of a major vault protein (MVP), two minor vault proteins [telomerase-associated protein 1 (TEP1), vault poly(ADP-ribose) polymerase (VPARP)] and small untranslated RNA molecules. Not all expressed TEP1 and VPARP in cells is bound to vaults. TEP1 is known to associate with the telomerase complex, whereas VPARP is also present in the nuclear matrix and in cytoplasmic clusters (VPARP-rods). We examined the subcellular localization and the dynamics of the vault complex in a non-small cell lung cancer cell line expressing MVP tagged with green fluorescent protein. Using quantitative fluorescence recovery after photobleaching (FRAP) it was shown that vaults move temperature independently by diffusion. However, incubation at room temperature (21 degrees C) resulted in the formation of distinct tube-like structures in the cytoplasm. Raising the temperature could reverse this process. When the vault-tubes were formed, there were fewer or no VPARP-rods present in the cytoplasm, suggesting an incorporation of the VPARP into the vault-tubes. MVP molecules have to interact with each other via their coiled-coil domain in order to form vault-tubes. Furthermore, the stability of microtubules influenced the efficiency of vault-tube formation at 21 degrees C. The dynamics and structure of the tubes were examined using confocal microscopy. Our data indicate a direct and dynamic relationship between vaults and VPARP, providing further clues to unravel the function of vaults

Partitions with Prescribed Hook Differences

We investigate partition identities related to off-diagonal hook differences. Our results generalize previous extensions of the Rogers—Ramanujan identities. The identity of the related polynomials with constructs in statistical mechanics is discussed