Characterization of Cold-Formed Steel Framed Diaphragm Response under In-Plane Loading and Influence of Non-Structural Gypsum Panels

The in-plane response of CFS framed diaphragm structures subjected to seismic excitation is not well understood. At present, the North American AISI S400 Standard does not include a seismic design procedure for CFS framed diaphragms for use in Canada, and offers limited information for their use in the US. In addition, the effect of non-structural components on the lateral strength and stiffness of the diaphragm component has yet to be explored. In an effort to provide insight into the complex nature of the diaphragm structure and the influence of non- structural components an experimental program was initiated in the Jamieson Structures Laboratory at McGill University focusing on the characterization of the behaviour of CFS framed - wood sheathed diaphragms under in-plane loading. This paper presents the results for four diaphragm configurations with oriented strand board sheathing (OSB) tested under monotonic and reversed cyclic loading following the cantilever test method. The 3.7m x 6.1m diaphragm specimens were constructed with different structural configurations as well as non-structural gypsum panels below the steel framing. Design predictions for the shear strength and deflection of the diaphragm specimens were obtained using the information available in the AISI S400 Standard

Seismic Performance Characterization of Wood-Sheathed and Cold-Formed Steel Framed Floor and Roof Diaphragm Structures

This paper describes a research program involving wood-sheathed and cold-formed steel (CFS) framed diaphragm assemblies.The diaphragm’s response to in-plane monotonic and reversed cyclic lateral loading is investigated in an effort to characterize the seismic performance of this assembly. The work presented herein focuses on the response to loading of the isolated diaphragm subsystem and serves as a complementary study to a research project involving the dynamic testing of full-scale two-story CFS framed buildings, known as the CFS–Network for Earthquake Engineering Simulation (NEES) project. Laboratory testing included eight 3.66 × 6.1-m diaphragm specimens, that is, four configurations, comprising oriented strand board (OSB) sheathing screw connected to CFS C-Channel joists. The response to loading is directly related to screw pattern and size, the use of panel edge blocking, and the type of sheathing. By means of a comparison of design and experimental shear strength and stiffness values, the provisions of the AISI S400 standard were shown to be in need of improvement regarding the number of listed diaphragm configurations. Deflection predications at the design load level were considered to be reasonable

Listing Occupational Carcinogens

The occupational environment has been a most fruitful one for investigating the etiology of human cancer. Many recognized human carcinogens are occupational carcinogens. There is a large volume of epidemiologic and experimental data concerning cancer risks in different work environments. It is important to synthesize this information for both scientific and public health purposes. Various organizations and individuals have published lists of occupational carcinogens. However, such lists have been limited by unclear criteria for which recognized carcinogens should be considered occupational carcinogens, and by inconsistent and incomplete information on the occupations and industries in which the carcinogenic substances may be found and on their target sites of cancer. Based largely on the evaluations published by the International Agency for Research on Cancer, and augmented with additional information, the present article represents an attempt to summarize, in tabular form, current knowledge on occupational carcinogens, the occupations and industries in which they are found, and their target organs. We have considered 28 agents as definite occupational carcinogens, 27 agents as probable occupational carcinogens, and 113 agents as possible occupational carcinogens. These tables should be useful for regulatory or preventive purposes and for scientific purposes in research priority setting and in understanding carcinogenesis

A horseshoe crab (Arthropoda: Chelicerata: Xiphosura) from the Lower Devonian (Lochkovian) of Yunnan, China

This is the publisher's version, also available electronically from http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8826898&fileId=S0016756812000891A single specimen of a new species of the synziphosurine Kasibelinurus Pickett, 1993 is described from the Lower Devonian (Lochkovian) Xiaxishancun Formation of Yunnan Province, China. The new species, K. yueya sp. nov., extends the geographic extent of the family Kasibelinuridae from the Australian palaeocontinent to the South China palaeocontinent, and the stratigraphic range back some 50 Ma from Late to Early Devonian

Deep tissue penetration of bottle-brush polymers via cell capture evasion and fast diffusion

Drug nanocarriers (NCs) capable of crossing the vascular endothelium and deeply penetrating into dense tissues of the CNS could potentially transform the management of neurological diseases. In the present study, we investigated the interaction of bottle-brush (BB) polymers with different biological barriers in vitro and in vivo and compared it to nanospheres of similar composition. In vitro internalization and permeability assays revealed that BB polymers are not internalized by brain-associated cell lines and translocate much faster across a blood–brain barrier model compared to nanospheres of similar hydrodynamic diameter. These observations performed under static, no-flow conditions were complemented by dynamic assays performed in microvessel arrays on chip and confirmed that BB polymers can escape the vasculature compartment via a paracellular route. BB polymers injected in mice and zebrafish larvae exhibit higher penetration in brain tissues and faster extravasation of microvessels located in the brain compared to nanospheres of similar sizes. The superior diffusivity of BBs in extracellular matrix-like gels combined with their ability to efficiently cross endothelial barriers via a paracellular route position them as promising drug carriers to translocate across the blood–brain barrier and penetrate dense tissue such as the brain, two unmet challenges and ultimate frontiers in nanomedicine

Current position of 5HT3 antagonists and the additional value of NK1 antagonists; a new class of antiemetics

The advent of the 5HT3 receptor antagonists (5HT3 antagonists) in the 1990s and the combination with dexamethasone has resulted in acute emesis protection in 70% of patients receiving highly emetogenic chemotherapy. Despite complete protection in the acute phase, however, 40% of patients as yet have symptoms in the delayed phase, 5HT3 antagonists and dexamethasone are only modestly effective in this delayed phase. Moreover, the antiemetic protection over repeated cycles is not sustained. Neurokinine 1 receptor antagonists (NK1 antagonists) belong to a new class of antiemetic agents that specifically target the NK1 receptor, which is involved in both the acute and, particularly, the delayed phase of emesis. Clinical studies have demonstrated that the addition of NK1 antagonists to dual therapy with a 5HT3 antagonist plus dexamethasone improves the acute emesis protection by a further 10-15%. In the delayed phase, the proportion of patients remaining free of emesis increases by even 20-30%. Since the effectiveness of this triplet combination was found to be sustained over six cycles of chemotherapy, the chance for an individual patient to remain completely protected during both the acute and the delayed phase over six chemotherapy cycles is nearly doubled

Higher Level Phylogeny and the First Divergence Time Estimation of Heteroptera (Insecta: Hemiptera) Based on Multiple Genes

Heteroptera, or true bugs, are the largest, morphologically diverse and economically important group of insects with incomplete metamorphosis. However, the phylogenetic relationships within Heteroptera are still in dispute and most of the previous studies were based on morphological characters or with single gene (partial or whole 18S rDNA). Besides, so far, divergence time estimates for Heteroptera totally rely on the fossil record, while no studies have been performed on molecular divergence rates. Here, for the first time, we used maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) with multiple genes (18S rDNA, 28S rDNA, 16S rDNA and COI) to estimate phylogenetic relationships among the infraorders, and meanwhile, the Penalized Likelihood (r8s) and Bayesian (BEAST) molecular dating methods were employed to estimate divergence time of higher taxa of this suborder. Major results of the present study included: Nepomorpha was placed as the most basal clade in all six trees (MP trees, ML trees and Bayesian trees of nuclear gene data and four-gene combined data, respectively) with full support values. The sister-group relationship of Cimicomorpha and Pentatomomorpha was also strongly supported. Nepomorpha originated in early Triassic and the other six infraorders originated in a very short period of time in middle Triassic. Cimicomorpha and Pentatomomorpha underwent a radiation at family level in Cretaceous, paralleling the proliferation of the flowering plants. Our results indicated that the higher-group radiations within hemimetabolous Heteroptera were simultaneously with those of holometabolous Coleoptera and Diptera which took place in the Triassic. While the aquatic habitat was colonized by Nepomorpha already in the Triassic, the Gerromorpha independently adapted to the semi-aquatic habitat in the Early Jurassic

Rapid whole genome optical mapping of Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p>Immune evasion and drug resistance in malaria have been linked to chromosomal recombination and gene copy number variation (CNV). These events are ideally studied using comparative genomic analyses; however in malaria these analyses are not as common or thorough as in other infectious diseases, partly due to the difficulty in sequencing and assembling complete genome drafts. Recently, whole genome optical mapping has gained wide use in support of genomic sequence assembly and comparison. Here, a rapid technique for producing whole genome optical maps of <it>Plasmodium falciparum </it>is described and the results of mapping four genomes are presented.</p> <p>Methods</p> <p>Four laboratory strains of <it>P. falciparum </it>were analysed using the Argus™ optical mapping system to produce ordered restriction fragment maps of all 14 chromosomes in each genome. <it>Plasmodium falciparum </it>DNA was isolated directly from blood culture, visualized using the Argus™ system and assembled in a manner analogous to next generation sequence assembly into maps (AssemblyViewer™, OpGen Inc.^®). Full coverage maps were generated for <it>P. falciparum </it>strains 3D7, FVO, D6 and C235. A reference <it>P. falciparum in silico </it>map was created by the digestion of the genomic sequence of <it>P. falciparum </it>with the restriction enzyme AflII, for comparisons to genomic optical maps. Maps were then compared using the MapSolver™ software.</p> <p>Results</p> <p>Genomic variation was observed among the mapped strains, as well as between the map of the reference strain and the map derived from the putative sequence of that same strain. Duplications, deletions, insertions, inversions and misassemblies of sizes ranging from 3,500 base pairs up to 78,000 base pairs were observed. Many genomic events occurred in areas of known repetitive sequence or high copy number genes, including <it>var </it>gene clusters and <it>rifin </it>complexes.</p> <p>Conclusions</p> <p>This technique for optical mapping of multiple malaria genomes allows for whole genome comparison of multiple strains and can assist in identifying genetic variation and sequence contig assembly. New protocols and technology allowed us to produce high quality contigs spanning four <it>P. falciparum </it>genomes in six weeks for less than $1,000.00 per genome. This relatively low cost and quick turnaround makes the technique valuable compared to other genomic sequencing technologies for studying genetic variation in malaria.</p