Control of vertebrate left-right asymmetry by a snail-related zinc finger gene

A gene encoding a zinc finger protein of the Snail family, cSnR, is expressed in the right-hand lateral mesoderm during normal chick development. Antisense disruption of cSnR function during the hours immediately preceding heart formation randomized the normally reliable direction of heart looping and subsequent embryo torsion. Implanted ectopic sources of intercellular signal proteins that are involved in establishing normal left-right information randomized the handedness of heart development and also altered the asymmetry of cSnR expression. cSnR thus appears to act downstream of these signals, or perhaps in parallel with the latest expressed of them, the Nodal protein, in controlling the anatomical asymmetry.     

Effects of processing conditions and packaging material on the quality attributes of dry‐roasted peanuts

Five different processing conditions of raw shelled unblanched peanuts were investigated. The first two treatments involved soaking the peanuts in tap water for 10 and 30 min respectively, then mixing thoroughly with dry NaCl before roasting. Another two treatments involved soaking the peanuts in saturated brine solution for 10 and 30 min respectively before roasting. Unsalted roasted peanuts served as the control. Packaging and storage studies were carried out by packaging the differently treated dry‐roasted peanuts in four different packaging materials and storing them under three different relative humidities for 3 months at ambient temperature. Proximate composition, NaCl content, peroxide value and thiobarbituric acid value were determined and sensory evaluation tests were carried out. Salting was found to improve the taste, flavour and overall acceptability of dry‐roasted peanuts but had no effect on shelf‐life. Peanuts treated in saturated brine solution for 30 min before roasting were the most preferred. The control packaging material, 18 µm transparent polyethylene, was found to be inadequate for protecting the quality attributes of dry‐roasted peanuts, with mould growth being observed on the 42nd day of storage at 80% relative humidity. However, acceptable results were obtained with 45 µm transparent polypropylene. The mean sensory scores and objective tests were found to be negatively correlated. © 2002 Society of Chemical Industry     

Fatigue properties of hemp and glass fiber composites

The fatigue properties of nonwoven randomly oriented short hemp fiber mat and chopped strand mat (CSM) glass fiber reinforced polyester composites have been studied, mainly in tension–tension mode. Despite having poorer absolute fatigue strength, the hemp fiber composites exhibited less fatigue sensitivity as compared with the CSM glass fiber composites in tension–tension fatigue. This could be correlated with the lower stiffness degradation observed during fatigue of the hemp fiber composites as compared with the glass fiber composites at the same normalized peak stress levels. Also, images recorded during fatigue loading showed that the hemp fiber composites were better at resisting crack formation and growth than the glass fiber composites. These results suggest that hemp fiber composites have the potential to replace glass fiber composites in applications where components are subjected to fatigue loads but the stress levels are of moderate value. POLYM. COMPOS., 35:1926–1934, 2014. © 2014 Society of Plastics Engineers     

Coupling automated radon and carbon dioxide measurements in coastal waters

Groundwater discharge could be a major, but as yet poorly constrained, source of carbon dioxide to lakes, wetlands, rivers, estuaries, and coastal waters. We demonstrate how coupled radon ((222)Rn, a natural groundwater tracer) and pCO(2) measurements in water can be easily performed using commercially available gas analysers. Portable, automated radon and pCO(2) gas analysers were connected in series and a closed air loop was established with gas equilibration devices (GED). We experimentally assessed the advantages and disadvantages of six GED. Response times shorter than 30 min for (222)Rn and 5 min for pCO(2) were achieved. Field trials revealed significant positive correlations between (222)Rn and pCO(2) in estuarine waterways and in a mangrove tidal creek, implying that submarine groundwater discharge was a source of CO(2) to surface water. The described system can provide high resolution, high precision concentrations of both radon and pCO(2) with nearly no additional effort compared to measuring only one of these gases. Coupling automated (222)Rn and pCO(2) measurements can provide new insights into how groundwater seepage contributes to aquatic carbon budgets.     

The group lock and its applications

Parallel algorithms that use shared resources are notoriously difficult to write and verify, especially when properties such as fairness and efficiency are desired. This paper introduces a new synchronization method called the group lock. This method has some of the advantages of strict synchronization methods such as monitors; algorithms written using group lock are quite clear and easy to verify. At the same time, these algorithms generally make better use of parallelism than those written using stricter synchronization methods. In many cases we can obtain worst case time bounds that are constant or logarithmic in the number of processes, thus also insuring bounded fairness. The paper begins with a discussion of related synchronization methods and an introduction to the group lock. This is followed by some examples of applications in algorithms for a readers/writers problem, parallel stacks and queues, implementation of fetch- and-phi routines, and others. Finally, two implementations of group lock are described. A detailed implementation is given for the paracomputer, an idealized MIMD multiprocessor that supports the fetch-and-add synchronization instruction. An implementation is also outlined for general CREW multiprocessors using only reads and writes to shared memory.     

On the deployment of a real scalable delegation service

This paper explains the evolution of the concept of delegation since its first references in the context of distributed authorization to the actual use as a fundamental part of a privilege management architecture. The work reviews some of the earliest contributions that pointed out the relevance of delegation when dealing with distributed authorization, in particular we comment on PolicyMaker and KeyNote, and also on SDSI/SPKI. Then, we elaborate on Federation as a particular case of delegation, and remark the importance given to Federation by the industry. Finally, the paper discusses about Privilege Management Infrastructures, introducing a new mechanism to extend their functionality using advanced delegation services.