Benchmarking stateless NAT64 implementations with a standard tester

RFC 5180, the IPv6 update of RFC 2544, declared IPv6 transition technologies out of its scope. RFC 8219 defined a benchmarking methodology for IPv6 transition technologies including stateless NAT64 (more properly called SIIT) in the category of single translation solutions. Whereas several research papers have dealt with the performance of different stateful NAT64 implementations, none of them used RFC 8219 compliant measurements or addressed stateless NAT64 implementations. In this paper, we show, how stateless NAT64 implementations can be benchmarked carrying out the most important tests recommended by RFC 8219 without a special purpose NAT64 Tester, using simply an RFC 2544/RFC 5180 compliant legacy Tester. We carry out benchmarking measurements to examine the performance of three free software NAT64 implementations, namely: Jool, TAYGA and map646. All the details of our measurements are disclosed and their results are presented in the paper.

Influence of Casting Conditions on Tribological Properties of A390.0 Alloy

The paper presents tribological properties of A390.0 (AlSi17Cu5Mg) alloy coupled in abrasive action with EN-GJL-350 grey cast-iron. The silumin was prepared with the use of two different technologies which differed in terms of cooling speed. In the first case the alloy was modified with foundry alloy CuP10 and cast to a standard tester ATD and in case of second option the modified alloy was cast into steel casting die. Due to different speed of heat removal the silumins varied in structure, particularly with size of primary crystals of silicon and their distribution in matrix which had a significant influence of friction coefficient in conditions of dry friction.

First Report of Fusarium proliferatum Causing Rot on Garlic and Onion in Argentina

In October 2001 and January 2002, in onion fields (Allium cepa L. cv Valencianita) in the Provinces of San Juan (SJ) and Mendoza (MZ), Argentina, plants were observed with chlorosis, dry leaf tips, and bulbs showing discoloration and rot. During the summer of 2002, a tan rot with white mycelium in rot cavities was also observed in stored garlic bulbs (Allium sativum) in MZ. Four monosporic cultures obtained with a micro punch adapted microscope (three from onion CSJ1, CMZ1, CMZ2 and one from garlic AMZ1) were characterized by morphology on PDA and carnation leaf agar (2). The isolates were deposited in the fungal collection of the Plant Mycosis Laboratory of the Integrated Unit Balcarce. The isolates produced abundant aerial white mycelium and a violet to vinaceous pigmentation. Club-shaped microconidia were abundant, in chains on both mono- and polyphialides. Slender, thin-walled and relatively straight macroconidia were produced only under black light and were mostly 3-septate. Chlamydospores were absent. The isolates were identified as Fusarium proliferatum. Crosses to confirm mating populations and to identify mating types were made in triplicate on carrot agar (3) with standard tester strains D-04853 (MATD-2) and D-04854 (MATD-1) as female parents and the field isolates as male parents. Crosses were examined weekly and were scored positive only if perithecia were seen oozing a cirrhus of ascospores. The identities of these isolates were confirmed as showing positive crosses with standard tester strains of Gibberella intermedia. Pathogenicity tests were conducted with healthy 45-day-old onion seedlings (cv. Valcatorce INTA). The roots of the onion seedlings were soaked in a conidial suspension (5 × 106 conidia/ml) of each isolate (CSJ1, CMZ1, CMZ2) for 2 h; the control was soaked in sterile water (SW). Seedlings were transplanted to pots in a sterile mixture of soil and sand (v/v). Five plants were used for each of 3 replications. The plants were placed in a greenhouse and irrigated with SW. After 3 weeks, symptoms were evaluated. All inoculated plants exhibited symptoms similar to those observed in the bulbs from which the pathogen was isolated and a brown rot appeared on the basal plate of the onion, later becoming dark brown. In garlic, the inoculation consisted of a wound 4.5 mm deep and 2 mm wide in superficially sterilized garlic cloves (cv. Nieve INTA). Inside the cavity, a drop (50 μl) was placed from a suspension of 5 × 106 conidia/ml (AMZ1), then covered with a drop of paraffin. Controls used SW. The garlic cloves were incubated in hermetically sealed trays at 22 ± 3°C in darkness for 3 weeks (1). Garlic showed tan rot and white mycelium in the wound. F. proliferatum was reisolated from inoculated onion seedlings and garlic cloves. The controls did not exhibit symptoms nor were any fungi recovered when tissue was excised from the inoculation points and plated on agar. F. proliferatum was previously reported in Argentina on asparagus (4) with symptoms similar to those of onion and garlic. To our knowledge, this is the first report of F. proliferatum attacking onion and garlic in Argentina. This pathogen has the potential risk of mycotoxin accumulation in contaminated bulbs. References: (1) F. M. Dugan et al. J. Phytopathol. 155:437, 2007. (2) W. Gerlach and H. Nirenberg. The genus Fusarium – A Pictorial Atlas. Mitt. Biol. Bundesanst. Land. Forstwirsch. Berl.-Dahlem, 1982. (3) C. J. R. Klittich and J. F. Leslie. Genetics 118:417, 1988. (4) G. Lori et al. Plant Dis. 82:1405, 1998.

Molecular Standardization of Mating Type Terminology in the Gibberella fujikuroi Species Complex

ABSTRACT Mating type in the Gibberella fujikuroi species complex is controlled by a single locus with two alleles and is usually identified following sexual crosses with standard, female-fertile tester isolates. The mating type alleles have been arbitrarily designated “+” and “−” within each biological species, and the nomenclature is tied to the standard tester strains. We developed a pair of PCR primers that can be used to amplify a unique fragment of one of the mating type alleles (MAT-2) from at least seven of the biological species in this species complex. Based on the amplification pattern, we propose a replacement for the existing, arbitrary +/− terminology that is presently in use. The new terminology is based on DNA sequence similarities between the mating type allele fragments from the biological species of the G. fujikuroi species complex and the corresponding fragments from other filamentous ascomycetes.

Fusarium subglutinans f. sp.pini Represents a Distinct Mating Population in theGibberella fujikuroi Species Complex

ABSTRACT Fusarium strains in the Gibberella fujikuroi species complex cause diseases on a variety of economically important plants. One of these diseases, pitch canker of Pinus spp., is caused by strains identified asFusarium subglutinans f. sp. pini. Fertile crosses were detected between F. subglutinans f. sp.pini strains from South Africa, California, and Florida.F. subglutinans f. sp. pini strains were not cross-fertile with the standard tester strains of six of the seven other mating populations of G. fujikuroi. Sporadic perithecia with ascospores were obtained in two crosses with the mating population B tester strains. These perithecia were homothallic, and the ascospores derived from these perithecia were vegetatively compatible with the mating population B tester strain parent. We concluded that fertile F. subglutinans f. sp. pini isolates represent a new mating population (mating population H) of G. fujikuroi and that they belong to a unique biological species in a distinct taxon.

Comparison of Standard and Microtests for International Rubber Hardness

1. Results obtained with an electronic microtester and the standard testers for International Rubber Hardness agree within about 1 IRHD unless there is a pronounced hardening near the surface or other nonuniformity of the compound. 2. The precision of test is not quite as good with the microtester as with the standard tester, but the precision obtained with the microtester can probably be improved by using a visual indicator in place of the audio indicator for detecting the null position. 3. The values of hardness are more dependent on thickness of the specimen at low levels of hardness than at high levels. The ratio of thicknesses to be used with the standard and microtesters appears to be 4:1, rather than 6:1, in order to obtain comparable results. 4. Some compounds exhibit a pronounced hardening near the surface or other nonhomogeneity, which causes high and erratic values of hardness, particularly with the microtester. 5. The incorporation of the microtest for rubber hardness in ASTM Method D 1415 is recommended. It is particularly useful for measuring the hardness of small rubber parts, for which there is no satisfactory test at the present time in the Book of ASTM Standards.