The preparation of ketene dithioacetals and thiophenes from chloropyridines containing an active methylene group

The base catalysed reaction of carbon disulphide with the active methylene groups of chloropyridines 4 and 7, followed by alkylation with reagents which also contain active methylene groups, lead to ketene dithioacetals. Further reaction with base afforded highly substituted thiophenes

Combining internal- and external-training-load measures in professional rugby league

Purpose: This study investigated the effect of training mode on the relationships between measures of training load in professional rugby league players. Methods: Five measures of training load (internal: individualized training impulse, session rating of perceived exertion; external—body load, high-speed distance, total impacts) were collected from 17 professional male rugby league players over the course of two 12-week pre-season periods. Training was categorized by mode (small-sided games, conditioning, skills, speed, strongman, and wrestle) and subsequently subjected to a principal component analysis. Extraction criteria were set at an eigenvalue of greater than one. Modes that extracted more than one principal component were subjected to a varimax rotation. Results: Small-sided games and conditioning extracted one principal component, explaining 68% and 52% of the variance, respectively. Skills, wrestle, strongman, and speed extracted two principal components explaining 68%, 71%, 72%, and 67% of the variance respectively. Conclusions: In certain training modes the inclusion of both internal and external training load measures explained a greater proportion of the variance than any one individual measure. This would suggest that in those training modes where two principal components were identified, the use of only a single internal or external training load measure could potentially lead to an underestimation of the training dose. Consequently, a combination of internal and external load measures is required during certain training modes

Investigation of Methodologies Used by Less-Than-Truckload (LTL) Motor Carriers to Determine Fuel Surcharges

Fuel surcharge policies are utilized by transportation companies to transfer the expense associated with fuel prices to their customers. As fuel surcharges have become a significant portion of the expenses on transportation invoices, an increasing number of shippers are expressing more interest in these policies. The objective of this study is to discover how less-than-truckload (LTL) carriers develop and utilize fuel surcharge policies to recover their fuel expenses. Thirty-nine top LTL carriers were called on to explain their perspectives and methodologies with regard to fuel surcharge policies. Part-to-whole qualitative analysis was conducted to summarize responses from a standardized interview protocol. In addition, 25 published fuel surcharge policies were obtained and analyzed to explore the disparities among LTL fuel surcharge policies. Findings show that, while carriers were reluctant to discuss their fuel surcharge development, in practice there were two primary methodologies that left all carriers with very similar fuel surcharge policies

Investigation of Methodologies Used by Less-Than-Truckload (LTL) Motor Carriers to Determine Fuel Surcharges

The objective of this study was to discover how less-than-truckload (LTL) carriers develop and utilize fuel surcharge policies to recover their fuel expenses. Thirty-nine top LTL carriers were contacted to explain their perspectives and methodologies with regard to fuel surcharge policies. Part-to-whole qualitative analysis was conducted to summarize responses from a standardized interview protocol. In addition, twenty-five published fuel surcharge policies were analyzed. Findings show that, while carriers were reluctant to discuss their fuel surcharge development, in practice there were two primary methodologies that left all carriers with very similar fuel surcharge policies

TCF/Lef regulates the Gsx ParaHox gene in central nervous system development in chordates

This research was supported by a BBSRC-DTG studentship to M.G.G, and Clarendon, ORS and EPA Cephalosporin scholarships to P.W.O.Background The ParaHox genes play an integral role in the anterior-posterior (A-P) patterning of the nervous system and gut of most animals. The ParaHox cluster is an ideal system in which to study the evolution and regulation of developmental genes and gene clusters, as it displays similar regulatory phenomena to its sister cluster, the Hox cluster, but offers a much simpler system with only three genes. Results Using Ciona intestinalis transgenics, we isolated a regulatory element upstream of Branchiostoma floridae Gsx that drives expression within the central nervous system of Ciona embryos. The minimal amphioxus enhancer region required to drive CNS expression has been identified, along with surrounding sequence that increases the efficiency of reporter expression throughout the Ciona CNS. TCF/Lef binding sites were identified and mutagenized and found to be required to drive the CNS expression. Also, individual contributions of TCF/Lef sites varied across the regulatory region, revealing a partial division of function across the Bf-Gsx-Up regulatory element. Finally, when all TCF/Lef binding sites are mutated CNS expression is not only abolished, but a latent repressive function is also unmasked. Conclusions We have identified a B. floridae Gsx upstream regulatory element that drives CNS expression within transgenic Ciona intestinalis, and have shown that this CNS expression is dependent upon TCF/Lef binding sites. We examine the evolutionary and developmental implications of these results, and discuss the possibility of TCF/Lef not only as a regulator of chordate Gsx, but as a deeply conserved regulatory factor controlling all three ParaHox genes across the Metazoa.Publisher PDFPeer reviewe

Response of concrete structures to seismic motions

In this report the strength and behaviour of model reinforced concrete structures subjected to simulated seismic disturbances are examined. The performance of a closed loop electrohydraulic testing system used in conjunction with a small shaking table is described. This testing system could accurately reproduce seismic disturbances and was used in the testing of a single storey structure and two six storey structures. All structures had a single bay in each direction and they were approximately one fifth of full size. The problems associated with modelling work are discussed and techniques suitable for constructing small scale three-dimensional model reinforced concrete structures are reported. Loading tests were conducted on typical beam and column structural members and the moment-curvature curves obtained are compared with those determined using theoretical methods. Both static and dynamic cyclic lateral loading tests were conducted on the structures and the apparent strengths of the structures under each type of loading are compared. The accuracy of an existing frame analysis program in predicting the displacement response of the model structures to simulated seismic disturbances is discussed and the more important parameters affecting the response are investigated. The experiments revealed that under lateral loading considerable torsion is induced into the lateral beams and that this may be sufficient to cause failure of those beams. A method is presented for calculating the distribution of torsion induced in the lateral beams and for calculating the magnitude of the torsional contribution to the flexural strength of the longitudinal beams. A discussion on collapse mechanisms is included and a design recommendation is made to reduce the likelihood of the structure collapsing by a column sidesway mechanism

Predictions of sediment trap biases in turbulent flows: A theoretical analysis based on observations from the literature

The physical variables affecting the trapping of particles in sediment collectors are grouped into a set of six dimensionless parameters, as a function of a dimensionless particle collection efficiency. Relevant laboratory calibration studies on sediment trap biases are evaluated to determine the quantitative dependence between collection efficiency and three of the parameters, trap Reynolds number, the ratio of flow speed to particle fall velocity and the ratio of trap height to mouth diameter, as well as trap geometry. We find that few of the parameters have been systematically tested in the laboratory and that trap Reynolds number-similarity for field conditions is maintained only for the slowest flow speeds and/or smallest trap diameters. However, the literature results do suggest some intriguing trends in biased trapping which also can be explained physically. The physical mechanisms are derived from a physical description of particle trapping based on observations of flow through traps, the mass balance for particles entering and leaving traps and a definition of particle collection efficiency, coupled with model development for cases where collection efficiency, as specified by the mass balance, deviates from one.The following testable hypotheses for biased trapping by unbaffied, straight-sided cylinders and noncylindrical traps result from our analysis. For fixed values of the other two parameters, collection efficiency of cylinders will decrease over some range of increasing trap Reynolds number, decrease over some range of decreasing particle fall velocity and increase over some range of increasing trap aspect ratio. Traps will be undercollectors or overcollectors depending on the physical mechanisms causing the biased collections. Predicting biased collections for noncylindrical traps is more complex but, in most cases, small-mouth, wide-body traps will be overcollectors and funnel-type traps will be undercollectors. Future laboratory studies are required to test these hypotheses and, in particular, parameter combinations representative of field conditions, where traps are deployed, must be tested