Alok-Imaging and -Reconstruction of Surface Defects on Heavy Plates with E.M.A.-Rayleigh Wave Transducers

High quality heavy plates have to be free of any defects. The UT-inspection for internal defects is introduced as a standard. However, until now the inspection for surface defects is limited to visual inspection, magnetic stray flux — or eddy current inspection. The most sensitive technique is the magnetic stray-flux technique, but it is very time consuming because of the necessity to scan the whole surface. Using Rayleigh waves the inspection can be automated and performed at rolling speed. The sensitivity of frequency optimized Rayleigh waves is sufficient to detect a 0.3 mm deep model defect at a distance of 300 mm. The use of piezoelectric probes is limited by coupling problems. These problems are overcome by the use of EMAT’s, which have been optimized with respect to probe size, sensitivity and wear resistance. For the automated inspection the ALOK-system has been adapted in a laboratory system to the surface inspection of heavy plates by Rayleigh waves. This equipment consists of an ultrasonic hardware device for fast data-acquisition and -preprocessing (essential data reduction) according to the ALOK-algorithm, and a computer to realize noise- and ghost — elimination as well as defect imaging and -reconstruction

CHIIMP: An automated high-throughput microsatellite genotyping approach reveals greater allelic diversity in wild chimpanzees

Short tandem repeats (STRs), also known as microsatellites, are commonly used to non invasively genotype wild-living endangered species, including African apes. Until recently, capillary electrophoresis has been the method of choice to determine the length of polymorphic STR loci. However, this technique is labor intensive, difficult to compare across platforms, and notoriously imprecise. Here we developed a MiSeq-based approach and tested its performance using previously genotyped fecal samples from long-term studied chimpanzees in Gombe National Park, Tanzania. Using data from eight microsatellite loci as a reference, we designed a bioinformatics platform that converts raw MiSeq reads into locus-specific files and automatically calls alleles after filtering stutter sequences and other PCR artifacts. Applying this method to the entire Gombe population, we confirmed previously reported genotypes, but also identified 31 new alleles that had been missed due to sequence differences and size homoplasy. The new genotypes, which increased the allelic diversity and heterozygosity in Gombe by 61% and 8%, respectively, were validated by replicate amplification and pedigree analyses. This demonstrated inheritance and resolved one case of an ambiguous paternity. Using both singleplex and multiplex locus amplification, we also genotyped fecal samples from chimpanzees in the Greater Mahale Ecosystem in Tanzania, demonstrating the utility of the MiSeq-based approach for genotyping non-habituated populations and performing comparative analyses across field sites. The new automated high-throughput analysis platform (available at https://github.com/ShawHahnLab/chiimp) will allow biologists to more accurately and effectively determine wildlife population size and structure, and thus obtain information critical for conservation efforts

ALOK-imaging and -reconstruction of surface defects on heavy plates with E.M.A.-Rayleigh wave transducers

High quality heavy plates have to be free of any defects. The UT-inspection for internal defects is introduced as a standard. However, until now the inspection for surface defects is limited to visual inspection, magnetic stray flux - or eddy current inspection. The most sensitive technique is the magnetic stray-flux technique, but it is very time consuming because of the necessity to scan the whole surface. Using Rayleigh waves the inspection can be automated and performed at rolling speed. The sensitivity of frequency optimized Rayleigh waves is sufficient to detect a 0.3mm deep model defect at a distance of 300mm. The use of piezoelectric probes is limited by coupling problems. These problems are overcome by the use of EMAT's, which have been optimized with respect to probe size, sensitivity and wear resistance. For the automated inspection the ALOK-system has been adapted in a laboratory system to the surface inspection of heavy plates by Rayleigh waves. This equipment consisits of an ultrasonic hardware device for fast data-acquisition and-preprocessing (essential data reduction) according to the ALOK-algorithm, and a computer to realize noise- and ghost- elimination as well as defect imaging and -reconstruction. Examples of the surface inspection of heavy plates using electromagnetically excited Rayleigh waves in connection with the ALOK data-acquisition and evaluation system are reported. The investigations were supported by the ECSC (European Community for Steal and Coal)

Resistance to type 1 interferons is a major determinant of HIV-1 transmission fitness

Sexual transmission of HIV-1 is an inefficient process, with only one or few variants of the donor quasispecies establishing the new infection. A critical, and as yet unresolved, question is whether the mucosal bottleneck selects for viruses with increased transmission fitness. Here, we characterized 300 limiting dilution-derived virus isolates from the plasma, and in some instances genital secretions, of eight HIV-1 donor and recipient pairs. Although there were no differences in the amount of virion-associated envelope glycoprotein, recipient isolates were on average threefold more infectious (P = 0.0001), replicated to 1.4-fold higher titers (P = 0.004), were released from infected cells 4.2-fold more efficiently (P < 0.00001), and were significantly more resistant to type I IFNs than the corresponding donor isolates. Remarkably, transmitted viruses exhibited 7.8-fold higher IFNα2 (P < 0.00001) and 39-fold higher IFNβ (P < 0.00001) half-maximal inhibitory concentrations (IC50) than did donor isolates, and their odds of replicating in CD4+ T cells at the highest IFNα2 and IFNβ doses were 35-fold (P < 0.00001) and 250-fold (P < 0.00001) greater, respectively. Interestingly, pretreatment of CD4+ T cells with IFNβ, but not IFNα2, selected donor plasma isolates that exhibited a transmitted virus-like phenotype, and such viruses were also detected in the donor genital tract. These data indicate that transmitted viruses are phenotypically distinct, and that increased IFN resistance represents their most distinguishing property. Thus, the mucosal bottleneck selects for viruses that are able to replicate and spread efficiently in the face of a potent innate immune response

Phenotypic properties of transmitted founder HIV-1.

Defining the virus-host interactions responsible for HIV-1 transmission, including the phenotypic requirements of viruses capable of establishing de novo infections, could be important for AIDS vaccine development. Previous analyses have failed to identify phenotypic properties other than chemokine receptor 5 (CCR5) and CD4+ T-cell tropism that are preferentially associated with viral transmission. However, most of these studies were limited to examining envelope (Env) function in the context of pseudoviruses. Here, we generated infectious molecular clones of transmitted founder (TF; n = 27) and chronic control (CC; n = 14) viruses of subtypes B (n = 18) and C (n = 23) and compared their phenotypic properties in assays specifically designed to probe the earliest stages of HIV-1 infection. We found that TF virions were 1.7-fold more infectious (P = 0.049) and contained 1.9-fold more Env per particle (P = 0.048) compared with CC viruses. TF viruses were also captured by monocyte-derived dendritic cells 1.7-fold more efficiently (P = 0.035) and more readily transferred to CD4+ T cells (P = 0.025). In primary CD4+ T cells, TF and CC viruses replicated with comparable kinetics; however, when propagated in the presence of IFN-α, TF viruses replicated to higher titers than CC viruses. This difference was significant for subtype B (P = 0.000013) but not subtype C (P = 0.53) viruses, possibly reflecting demographic differences of the respective patient cohorts. Together, these data indicate that TF viruses are enriched for higher Env content, enhanced cell-free infectivity, improved dendritic cell interaction, and relative IFN-α resistance. These viral properties, which likely act in concert, should be considered in the development and testing of AIDS vaccines