Sensors for Detection of Misbehaving Nodes in MANETs

The fact that security is a critical problem when implementing mobile ad hoc networks (MANETs) is widely acknowledged. One of the different kinds of misbehavior a node may exhibit is selfishness. A selfish node wants to preserve its resources while using the services of others and consuming their resources. One way of preventing selfishness in a MANET is a detection and exclusion mechanism. In this paper, we focus on the detection and present different kinds of sensors that will find selfish nodes. First we present simulations that show the negative effects which selfish nodes cause in MANET. In the related work section we will analyze the detection mechanisms proposed by others. Our new detection mechanisms that we describe in this paper are called activity-based overhearing, iterative probing, and unambiguous probing. Simulation-based analysis of these mechanisms show that they are highly effective and can reliably detect a multitude of selfish behaviors

Quantitative modeling of laser speckle imaging

We have analyzed the image formation and dynamic properties in laser speckle imaging (LSI) both experimentally and with Monte-Carlo simulation. We show for the case of a liquid inclusion that the spatial resolution and the signal itself are both significantly affected by scattering from the turbid environment. Multiple scattering leads to blurring of the dynamic inhomogeneity as detected by LSI. The presence of a non-fluctuating component of scattered light results in the significant increase in the measured image contrast and complicates the estimation of the relaxation time. We present a refined processing scheme that allows a correct estimation of the relaxation time from LSI data.Comment: submitted to Optics Letter

Hierarchical Superstructures by Combining Crystallization-Driven and Molecular Self-Assembly

Combining the unique corona structure of worm‐like patchy micelles immobilized on a polymer fiber with the molecular self‐assembly of 1,3,5‐benzenetricarboxamides (BTAs) leads to hierarchical superstructures with a fir‐tree‐like morphology. For this purpose, worm‐like patchy micelles bearing pendant, functional tertiary amino groups in one of the corona patches were prepared by crystallization‐driven self‐assembly and immobilized on a supporting polystyrene fiber by coaxial electrospinning. The obtained patchy fibers were then immersed in an aqueous solution of a tertiary amino‐functionalized BTA to induce patch‐mediated molecular self‐assembly to well‐defined fir‐tree‐like superstructures upon solvent evaporation. Interestingly, defined superstructures are obtained only if the pendant functional groups in the surface patches match with the peripheral substituents of the BTA, which is attributed to a local increase in BTA concentration at the polymer fibers’ surface

Inner Alpine conifer response to 20th century drought swings

Tree rings from the Alpine area have been widely used to reconstruct variations in summer temperature. In contrast, estimates of changes in the hydrological cycle are rather scarce. In order to detect altitudinal and species-specific patterns of growth responses to anomalous dry and wet conditions, a large network of 53 tree-ring width site chronologies along the Rhone valley (Valais, Switzerland) covering the 1751-2005 period was compiled and analyzed. A total of 1,605 measurement series from four conifer species—pine, larch, spruce, fir—were detrended to allow inter-annual to multi-decadal scale variability to be preserved. Site chronologies were combined to four altitudinal (colline: 1,450m asl) and species-specific mean time-series. These records were compared with temperature, precipitation, and drought (scPDSI) data. Among the altitudinal records, the colline chronologies showed highest correlation with June precipitation and scPDSI (0.5 and 0.7). Altitudinal effects, via control on climatic conditions, were superimposed upon species-specific characteristics in affecting tree growth and response to moisture variations. In particular, species-specific differences affected the significance level of drought response, with decreasing drought sensitivity towards higher elevations. Growth conditions were found to be optimal at ~1,300m asl, with precipitation/drought limiting tree growth below and temperature above. Common years of extreme drought and low growth for the colline sites occurred in 1921, 1944, 1976, 1992, and 1998. Our results demonstrate the potential of lower elevation conifers for reconstructing long-term changes in Alpine hydro-climat

Evaluation of a duplex real-time PCR in human serum for simultaneous detection and differentiation of Schistosoma mansoni and Schistosoma haematobium infections - cross-sectional study

Background: We evaluated a one-tube multiplex real-time PCR targeting DNA of Schistosoma haematobium complex and S. mansoni complex in serum samples obtained at different German diagnostic centers. Methods: Simplex real-time PCR protocols for the detection of the multi-copy DNA-repeats Dra1 of S. haematobium complex and Sm1-7 of S. mansoni complex in serum were combined to a new one-tube multiplex format. The new PCR was subjected to full validation including evaluation in a diagnostic real-life setting with travelers and migrants. PCR results were compared with those of stool and urine microscopy, serology, and circulating cathodic antigen (CCA) rapid diagnostic tests in urine. Sensitivity and specificity of the diagnostic approaches were analyzed using latent class analysis (LCA). Results: LCA assessment indicated sensitivity and specificity of 94.9% and 98.4%, respectively, for serum PCR if serology was included in the calculation, and 100% and 95.6%, respectively, if serology was not included as a parameter not necessarily associated with active infection. Agreement between the compared diagnostic procedures at genus level was fair (kappa 0.273) if serology was included and moderate (kappa 0.420) if serology was not included. Discussion: The PCR assay proved to be highly reliable for the diagnosis of schistosomiasis in travelers and migrants

Beiträge zu Rohstoffen in Sachsen

Das neue Geoprofil 17/2023 zu Rohstoffen in Sachsen enthält einen Beitrag zur Zinnmineralisation im Westerzgebirge sowie einen über den Delitzscher Karbonatit-Komplex. Der Sn-Vererzungstyp bei Bockau und Aue-Bad Schlema ist völlig verschieden von dem der Greisen-, Trümerzonen-, Gang- und Skarntypen und ist auch nicht vergleichbar mit der Zinnvererzung der Felsitzone bei Freiberg. Die neuen Untersuchungen erbrachten erstmalig den Nachweis einer im Erzgebirge verbreiteten low-grade mineralization vom Typ einer frühvariszischen polystadialen, vorwiegend monomineralischen und metamorph geprägten Erzbildung. Insbesondere durch Bohrarbeiten der SDAG Wismut ist die Verbreitung der ultramafischen Lamprophyre (UML) und Karbonatite mit oberkretazischem Alter im Gebiet von Delitzsch gut bekannt. Auf die Geologie des Komplexes wird detailliert eingegangen. Redaktionsschluss: 11.10.202

A MIF haplotype is associated with the outcome of patients with severe sepsis: a case control study

<p>Abstract</p> <p>Background</p> <p>Macrophage migration inhibitory factor (MIF) plays an important regulatory role in sepsis. In the promoter region a C/G single nucleotide polymorphism (SNP) at position -173 (rs755622) and a CATT_5-8microsatellite at position -794 are related to modified promoter activity. The purpose of the study was to analyze their association with the incidence and outcome of severe sepsis.</p> <p>Methods</p> <p>Genotype distributions and allele frequencies in 169 patients with severe sepsis, 94 healthy blood donors and 183 postoperative patients without signs of infection or inflammation were analyzed by real time PCR and Sequence analysis. All included individuals were Caucasians.</p> <p>Results</p> <p>Genotype distribution and allele frequencies of severe sepsis patients were comparable to both control groups. However, the genotype and allele frequencies of both polymorphisms were associated significantly with the outcome of severe sepsis. The highest risk of dying from severe sepsis was detectable in patients carrying a haplotype with the alleles -173 C and CATT₇(p = 0.0005, fisher exact test, RR = 1,806, CI: 1.337 to 2.439).</p> <p>Conclusion</p> <p>The haplotype with the combination of the -173 C allele and the -794 CATT₇allele may not serve as a marker for susceptibility to sepsis, but may help identify septic patients at risk of dying.</p