Rat control

During the past few years the rat population in Iowa has built up until it is now estimated that there are more than 5 million rats in the state. This rapid increase in population is due primarily to the tremendous volume of corn which is stored in temporary, hastily-constructed cribs that offer easy access to rats and furnish both food and shelter for them. To meet this situation, it is urged that rat control be made an integral part of good farm practice. Since rats move about from farm to farm, especially when they are disturbed by a vigorous control campaign on the part of a few farmers, community cooperation is desired. Rats menace not only our food and our farm animals; from the standpoint of health they threaten both humans and domestic animals, since they may act as reservoirs of infectious jaundice, endemic typhus and bubonic plague in man and trichinosis of hogs

Masonry barn design and construction

In 1913 an investigation was begun with the object of developing an all masonry barn which could be constructed at a reasonable cost and yet have the advantages of permanent and fire resistant construction. The studies which have been conducted pertain chiefly to the roof structure, with particular emphasis on the method of construction. In addition to a number of design studies, models of roof sections were built to develop a method of roof construction. Strength tests were made on roof models to check the reliability of the designs. The information obtained served as the basis of the design and method of constructing an experimental barn, which was built at Iowa State College in 1926-27. Common overall dimensions and a desirable roof shape were established to make the roof forms usable for a number of barns; wind load assumptions were adapted from reliable wind pressure investigations to permit a more intelligent and efficient roof design. The results of the design studies, construction and tests on models and roof sections, and the construction of the experimental barn, together with other related experiences, seem to warrant the following general conclusions: 1. The masonry arch is a very stable type of roof structure as shown by the tests on sections, which check closely the design calculations. 2. The construction of the roof is difficult and involves a large amount of labor because of: a. The use of heavy steel forms to carry a large part of the roof weight. b. The manipulation of the forms in erection, moving, dismantling and transporting. c. The handling and placing of roof materials. 3. The additional cost of the roof over a wood frame type construction is due. not so much to the cost of materials, as to the cost of the unproductive labor in handling the materials and in manipulation of the steel forms. The overhead cost of the forms becomes a large item in the first cost if they are used for only one or a few barns. 4. Experiments in the methods of making a roof watertight have not as yet indicated an entirely successful method. A heavy fibered asphalt has been found the best of the waterproof coatings which have been used. Leaks appear to be due to slight openings in the joints and to the development of fine cracks. 5. The construction of the roof should be directed by one . who is familiar with masonry construction. 6. A roof with a span of 34 ft. and a height of 20 ft. provides enough storage space for most conditions

What determines the length of life of prepared roll roofings?

The length of life of prepared roll roofings is a prime consideration in their selection. The durability of the various brands of roofing on the market varies widely. The useful life of a roof made of roll roofing is influenced by the degree of exposure to the weathering agencies, the condition of the sheathing and the inherent qualities of the roofing material itself. This bulletin is a summary of the results of an investigation, conducted cooperatively by the Agricultural and Engineering Experiment Stations, to determine the quality factors of three-ply prepared roll roofings as they were sold on the market at the beginning of the project in 1913. One roll or square of each of 35 brands of prepared roll roofing which were made by 19 manufacturers was purchased on the open market and included in the experiment. This provided sufficient material for one strip to be placed on the shed for weathering tests and enough additional for laboratory tests. Table I presents some general information and data of the physical qualities of the roofing sample. A review of literature on the subject reveals little work directly comparable with that given here other than the development of testing methods and specifications for prepared roll roofings

Efficient Large-scale Trace Checking Using MapReduce

The problem of checking a logged event trace against a temporal logic specification arises in many practical cases. Unfortunately, known algorithms for an expressive logic like MTL (Metric Temporal Logic) do not scale with respect to two crucial dimensions: the length of the trace and the size of the time interval for which logged events must be buffered to check satisfaction of the specification. The former issue can be addressed by distributed and parallel trace checking algorithms that can take advantage of modern cloud computing and programming frameworks like MapReduce. Still, the latter issue remains open with current state-of-the-art approaches. In this paper we address this memory scalability issue by proposing a new semantics for MTL, called lazy semantics. This semantics can evaluate temporal formulae and boolean combinations of temporal-only formulae at any arbitrary time instant. We prove that lazy semantics is more expressive than standard point-based semantics and that it can be used as a basis for a correct parametric decomposition of any MTL formula into an equivalent one with smaller, bounded time intervals. We use lazy semantics to extend our previous distributed trace checking algorithm for MTL. We evaluate the proposed algorithm in terms of memory scalability and time/memory tradeoffs.Comment: 13 pages, 8 figure

Wigner crystal versus Fermionization for one-dimensional Hubbard models with and without long-range interactions

The ground state properties of Hubbard model with or without long-range interactions in the regime with strongly repulsive on-site interaction are investigated by means of the exact diagonalization method. We show that the appearance of $N$-crests in the density profile of a trapped N-fermion system is a natural result of "fermionization" between antiparallel-spin fermions in the strongly repulsive limit and can not be taken as the only signature of Wigner crystal phase, as the static structure factor does not show any signature of crystallization. On the contrary, both the density distribution and static structure factor of Hubbard model with strong long-range interactions display clear signature of Wigner crystal. Our results indicate the important role of long-range interaction in the formation of Wigner crystal.Comment: 7 pages, 7 figure

Mannose-Specific Lectins from Marine Algae: Diverse Structural Scaffolds Associated to Common Virucidal and Anti-Cancer Properties.

To date, a number of mannose-specific lectins have been isolated and characterized from seaweeds, especially from red algae. In fact, man-specific seaweed lectins consist of different structural scaffolds harboring a single or a few carbohydrate-binding sites which specifically recognize mannose-containing glycans. Depending on the structural scaffold, man-specific seaweed lectins belong to five distinct structurally-related lectin families, namely (1) the griffithsin lectin family (beta-prism I scaffold); (2) the Oscillatoria agardhii agglutinin homolog (OAAH) lectin family (beta-barrel scaffold); (3) the legume lectin-like lectin family (beta-sandwich scaffold); (4) the Galanthus nivalis agglutinin (GNA)-like lectin family (beta-prism II scaffold); and, (5) the MFP2-like lectin family (MFP2-like scaffold). Another algal lectin from Ulva pertusa, has been inferred to the methanol dehydrogenase related lectin family, because it displays a rather different GlcNAc-specificity. In spite of these structural discrepancies, all members from the five lectin families share a common ability to specifically recognize man-containing glycans and, especially, high-mannose type glycans. Because of their mannose-binding specificity, these lectins have been used as valuable tools for deciphering and characterizing the complex mannose-containing glycans from the glycocalyx covering both normal and transformed cells, and as diagnostic tools and therapeutic drugs that specifically recognize the altered high-mannose N-glycans occurring at the surface of various cancer cells. In addition to these anti-cancer properties, man-specific seaweed lectins have been widely used as potent human immunodeficiency virus (HIV-1)-inactivating proteins, due to their capacity to specifically interact with the envelope glycoprotein gp120 and prevent the virion infectivity of HIV-1 towards the host CD4+ T-lymphocyte cells in vitro

Synthesis by the polyol process and ionic conductivity of nanostructured La2Mo2O9 powders

International audienceLa2Mo2O9 nanostructured powders were synthesized by the polyol process. The effects of the nature of the polyol, the refluxing time, the hydrolysis ratio, the metal concentration and the addition of hydroxide ions, on the purity and morphology of the powders are determined. Two main morphologies are observed, the particles being in the shape of platelets or spheres, with respectively diethylene glycol or ethylene glycol as solvent. A specific surface area of 24 m2/g was reached by varying the metal concentration. The conductivity measurements were recorded on pellets that present in some cases a closed porosity, the relative density reaching 95% without any milling step. According to the synthesis parameters, the grain conductivity can be slightly increased, the total conductivity remaining only slightly lower than that of pellets made of powders synthesized by solid state reaction

Simian immunodeficiency virus infection in wild-caught chimpanzees from Cameroon

Simian immunodeficiency viruses (SIVcpz) infecting chimpanzees (Pan troglodytes) in west central Africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([HIV-1]; groups M, N and O), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of SIVcpz still remains limited. In this study, we tested 71 wild-caught chimpanzees from Cameroon for evidence of SIVcpz infection. Thirty-nine of these were of the central subspecies (Pan troglodytes troglodytes), and 32 were of the Nigerian subspecies (Pan troglodytes vellerosus), as determined by mitochondrial DNA analysis. Serological analysis determined that one P. t. troglodytes ape (CAM13) harbored serum antibodies that cross-reacted strongly with HIV-1 antigens; all other apes were seronegative. To characterize the newly identified virus, 14 partially overlapping viral fragments were amplified from fecal virion RNA and concatenated to yield a complete SIVcpz genome (9,284 bp). Phylogenetic analyses revealed that SIVcpzCAM13 fell well within the radiation of the SIVcpzPtt group of viruses, as part of a clade including all other SIVcpzPtt strains as well as HIV-1 groups M and N. However, SIVcpzCAM13 clustered most closely with SIVcpzGAB1 from Gabon rather than with SIVcpzCAM3 and SIVcpzCAM5 from Cameroon, indicating the existence of divergent SIVcpzPtt lineages within the same geographic region. These data, together with evidence of recombination among ancestral SIVcpzPtt lineages, indicate long-standing endemic infection of central chimpanzees and reaffirm a west central African origin of HIV-1. Whether P. t. vellerosus apes are naturally infected with SIVcpz requires further study

Possibilità di sviluppo della coltivazione del sorgo per l'alimentazione del bestiame in Somalia

In 1979, a trial concerning yield differences between 2 different periods of harvesting (soft dough and complete maturation of the grain) of a sorghum hybrid BR has been carried out in Afgoy (Somalia). The effects of four nitrogen level have been also evaluated. The results show no effect of different nitrogen levels on total dry matter production and grain quality. Maximum dry matter yield and maximum F.U. production has been reached at complete maturation of the grain. General level of grain yield has been restricted in consequence of bird damage in spite of the presence of the gene BR